WorldWideScience

Sample records for pv power grid

  1. Overview of Recent Grid Codes for PV Power Integration

    DEFF Research Database (Denmark)

    Craciun, Bogdan-Ionut; Kerekes, Tamas; Sera, Dezso;

    2012-01-01

    and Distribution System Operators (DSOs) had to keep the safety and reliability of the network under strict rules and regulations. The aim of the paper is to realize a survey of recent Grid Codes (GC) and regulations for grid connected PV systems. The focus is on grid interface requirements, power quality concerns...... and Anti-Islanding (AI) issues regarding PV systems connected to low voltage (LV) and medium voltage (MV) levels of the network.......The challenge to bring down the cost of produced photovoltaic (PV) power had a major impact on the PV market and in consequence the grid operators experienced higher and higher PV power penetration. The growing share of this decentralized generation plants started to affect the grid stability...

  2. Grid Integration of Large PV Power Systems Using HVDC Link

    Directory of Open Access Journals (Sweden)

    Gamal Sowilam

    2016-09-01

    Full Text Available This paper explores the interconnection of large scale Photo-Voltaic (PV systems to the grid though a High Voltage Direct Current (HVDC link. HVDC link is recently utilized for transmission lines longer than 50 km. It is usually utilized to interconnect two asynchronous grids with the same or different frequencies while avoiding stability disturbances greatly. A suitable Maximum Power Point Tracking (MPPT techniques is employed to control the performance of the integrated PV system. The system of the HVDC link has two 12-pulse converter using thyristor-bridges. The delay and the extinction angles at the rectifier and the inverter units control the flow and the quantity of the transmitted power from the PV system into the grid. Fixed capacitors and filters are used to provide the AC side with the required reactive power and reduce the harmonic contents. For evaluation purposes, different simulation investigations are carried out with a detailed modeling using the MATLAB. These tests corroborate the efficacy of HVDC link for integrating large PV systems to electrical grids.

  3. Analysis of the influences of grid-connected PV power system on distribution grids

    Directory of Open Access Journals (Sweden)

    Dumitru Popandron

    2013-12-01

    Full Text Available This paper presents the analysis of producing an electric power of 2.8 MW using a solar photovoltaic plant. The PV will be grid connected to the distribution network. The study is focused on the influences of connecting to the grid of a photovoltaic system, using modern software for analysis, modeling and simulation in power systems.

  4. Delta Power Control Strategy for Multi-String Grid-Connected PV Inverters

    DEFF Research Database (Denmark)

    Sangwongwanich, Ariya; Yang, Yongheng; Blaabjerg, Frede

    2016-01-01

    With a still increasing penetration level of grid-connected PV systems, more advanced active power control functionalities have been introduced in certain grid regulations. A delta power constraint, where a portion of the active power from the PV panels is reserved during operation, is required...... for the entire PV system is achieved. Simulations and experiments have been performed on a 3-kW single-phase grid-connected PV system. The results have confirmed the effectiveness of the delta power control strategy, where the power reserve according to the delta power constraint is achieved under several...

  5. A Sensorless Power Reserve Control Strategy for Two-Stage Grid-Connected PV Systems

    DEFF Research Database (Denmark)

    Sangwongwanich, Ariya; Yang, Yongheng; Blaabjerg, Frede

    2017-01-01

    Due to the still increasing penetration of grid-connected Photovoltaic (PV) systems, advanced active power control functionalities have been introduced in grid regulations. A power reserve control, where namely the active power from the PV panels is reserved during operation, is required for grid...... to achieve the power reserve. In this method, the solar irradiance and temperature measurements that have been used in conventional power reserve control schemes to estimate the available PV power are not required, and thereby being a sensorless approach with reduced cost. Experimental tests have been...... support. In this paper, a cost-effective solution to realize the power reserve for two-stage grid-connected PV systems is proposed. The proposed solution routinely employs a Maximum Power Point Tracking (MPPT) control to estimate the available PV power and a Constant Power Generation (CPG) control...

  6. Grid Support in Large Scale PV Power Plants using Active Power Reserves

    DEFF Research Database (Denmark)

    Craciun, Bogdan-Ionut

    Photovoltaic (PV) systems are in the 3rd place in the renewable energy market, after hydro and wind power. The increased penetration of PV within the electrical power system has led to stability issues of the entire grid in terms of its reliability, availability and security of the supply....... As a consequence, Large scale PV Power Plants (LPVPPs) operating in Maximum Power Point (MPP) are not supporting the electrical network, since several grid triggering events or the increased number of downward regulation procedures have forced European Network of Transmission System Operators for Electricity...... (ENTSO-E) to continuously upgrade their Network Codes (NCs), moving their focus to grid stabilization features. Considering the technical challenges present in the nowadays power systems, the work presented in this thesis focuses on frequency and power ramp control strategies provided by LPVPPs...

  7. Delta Power Control Strategy for Multi-String Grid-Connected PV Inverters

    DEFF Research Database (Denmark)

    Sangwongwanich, Ariya; Yang, Yongheng; Blaabjerg, Frede

    2017-01-01

    With a still increasing penetration level of grid-connected PV systems, more advanced active power control functionalities have been introduced in certain grid regulations. A delta power constraint, where a portion of the active power from the PV panels is reserved during operation, is required....... Simulations and experiments have been performed on a 3-kW single-phase grid-connected PV system. The results have confirmed the effectiveness of the proposed delta power control strategy, where the power reserve according to the delta power constraint is achieved under several operating conditions....

  8. Large Scale Solar Power Integration in Distribution Grids: PV Modelling, Voltage Support and Aggregation Studies

    NARCIS (Netherlands)

    Samadi, A.

    2014-01-01

    Long term supporting schemes for photovoltaic (PV) system installation have led to accommodating large numbers of PV systems within load pockets in distribution grids. High penetrations of PV systems can cause new technical challenges, such as voltage rise due to reverse power flow during light load

  9. Grid Integration of PV Power based on PHIL testing using different Interface Algorithms

    DEFF Research Database (Denmark)

    Craciun, Bogdan-Ionut; Kerekes, Tamas; Sera, Dezso;

    2013-01-01

    Photovoltaic (PV) power among all renewable energies had the most accelerated growth rate in terms of installed capacity in recent years. Transmission System Operators (TSOs) changed their perspective about PV power and started to include it into their planning and operation, imposing PV systems...... and supply of ancillary services, first the grid has to be simulated using PHIL, but in order to achieve it, different interface algorithms (IA) had to be evaluated in terms of system stability and signal accuracy....

  10. Advanced Grid-Friendly Controls Demonstration Project for Utility-Scale PV Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Gevorgian, Vahan [National Renewable Energy Lab. (NREL), Golden, CO (United States); O' Neill, Barbara [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-01-21

    A typical photovoltaic (PV) power plant consists of multiple power electronic inverters and can contribute to grid stability and reliability through sophisticated 'grid-friendly' controls. The availability and dissemination of actual test data showing the viability of advanced utility-scale PV controls among all industry stakeholders can leverage PV's value from being simply an energy resource to providing additional ancillary services that range from variability smoothing and frequency regulation to power quality. Strategically partnering with a selected utility and/or PV power plant operator is a key condition for a successful demonstration project. The U.S. Department of Energy's (DOE's) Solar Energy Technologies Office selected the National Renewable Energy Laboratory (NREL) to be a principal investigator in a two-year project with goals to (1) identify a potential partner(s), (2) develop a detailed scope of work and test plan for a field project to demonstrate the gird-friendly capabilities of utility-scale PV power plants, (3) facilitate conducting actual demonstration tests, and (4) disseminate test results among industry stakeholders via a joint NREL/DOE publication and participation in relevant technical conferences. The project implementation took place in FY 2014 and FY 2015. In FY14, NREL established collaborations with AES and First Solar Electric, LLC, to conduct demonstration testing on their utility-scale PV power plants in Puerto Rico and Texas, respectively, and developed test plans for each partner. Both Puerto Rico Electric Power Authority and the Electric Reliability Council of Texas expressed interest in this project because of the importance of such advanced controls for the reliable operation of their power systems under high penetration levels of variable renewable generation. During FY15, testing was completed on both plants, and a large amount of test data was produced and analyzed that demonstrates the ability of

  11. Demonstration of Active Power Controls by Utility-Scale PV Power Plant in an Island Grid: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Gevorgian, Vahan; O' Neill, Barbara

    2017-02-01

    The National Renewable Energy Laboratory (NREL), AES, and the Puerto Rico Electric Power Authority conducted a demonstration project on a utility-scale photovoltaic (PV) plant to test the viability of providing important ancillary services from this facility. As solar generation increases globally, there is a need for innovation and increased operational flexibility. A typical PV power plant consists of multiple power electronic inverters and can contribute to grid stability and reliability through sophisticated 'grid-friendly' controls. In this way, it may mitigate the impact of its variability on the grid and contribute to important system requirements more like traditional generators. In 2015, testing was completed on a 20-MW AES plant in Puerto Rico, and a large amount of test data was produced and analyzed that demonstrates the ability of PV power plants to provide various types of new grid-friendly controls. This data showed how active power controls can leverage PV's value from being simply an intermittent energy resource to providing additional ancillary services for an isolated island grid. Specifically, the tests conducted included PV plant participation in automatic generation control, provision of droop response, and fast frequency response.

  12. Grid-Connected Pv-Fc Hybrid System Power Control Using Mppt And Boost Converter

    Directory of Open Access Journals (Sweden)

    P.HARIKA

    2014-09-01

    Full Text Available This paper proposes a method for operating a grid connected hybrid system. This system composed of a Photovoltaic (PV array and a Proton exchange membrane fuel cell (PEMFC is considered. As the variations occur in temperature and irradiation during power delivery to load, Photo voltaic (PV system becomes uncontrollable. In coordination with PEMFC, the hybrid system output power becomes controllable. Two operation modes are the unit-power control (UPC mode and the feeder-flow control (FFC mode, can be applied to the hybrid system. All MPPT methods follow the same goal that is maximizing the PV system output power by tracking the maximum power on every operating condition. Maximum power point tracking technique (Incremental conductance for photovoltaic systems was introduced to maximize the produced energy. The coordination of two control modes, coordination of the PV array and the PEMFC in the hybrid system, and determination of reference parameters are presented. The proposed operating strategy systems with a flexible operation mode change always operate the PV array at maximum output power and the PEMFC in its high efficiency performance band. Also thus improving the performance of system operation, enhancing system stability, and reducing the number of operating mode changes.

  13. Grid tied PV/battery system architecture and power management for fast electric vehicle charging

    Science.gov (United States)

    Badawy, Mohamed O.

    The prospective spread of Electric vehicles (EV) and plug-in hybrid electric vehicles (PHEV) arises the need for fast charging rates. Higher charging rates requirements lead to high power demands, which cant be always supported by the grid. Thus, the use of on-site sources alongside the electrical grid for EVs charging is a rising area of interest. In this dissertation, a photovoltaic (PV) source is used to support the high power EVs charging. However, the PV output power has an intermittent nature that is dependable on the weather conditions. Thus, battery storage are combined with the PV in a grid tied system, providing a steady source for on-site EVs use in a renewable energy based fast charging station. Verily, renewable energy based fast charging stations should be cost effective, efficient, and reliable to increase the penetration of EVs in the automotive market. Thus, this Dissertation proposes a novel power flow management topology that aims on decreasing the running cost along with innovative hardware solutions and control structures for the developed architecture. The developed power flow management topology operates the hybrid system at the minimum operating cost while extending the battery lifetime. An optimization problem is formulated and two stages of optimization, i.e online and offline stages, are adopted to optimize the batteries state of charge (SOC) scheduling and continuously compensate for the forecasting errors. The proposed power flow management topology is validated and tested with two metering systems, i.e unified and dual metering systems. The results suggested that minimal power flow is anticipated from the battery storage to the grid in the dual metering system. Thus, the power electronic interfacing system is designed accordingly. Interconnecting bi-directional DC/DC converters are analyzed, and a cascaded buck boost (CBB) converter is chosen and tested under 80 kW power flow rates. The need to perform power factor correction (PFC) on

  14. Modified Grid-Connected CSI for Hybrid PV/Wind Power Generation System

    Directory of Open Access Journals (Sweden)

    D. Amorndechaphon

    2012-01-01

    Full Text Available The principle of a power conditioning unit for hybrid PV/wind power generation system is proposed. The proposed power conditioner is based on the current source inverter (CSI topology. All energy sources are connected in parallel with a DC-bus through the modified wave-shaping circuits. To achieve the unity power factor at the utility grid, the DC-link current can be controlled via the wave-shaping circuits with the sinusoidal PWM scheme. In this work, the carrier-based PWM scheme is also proposed to minimize the utility current THD. The power rating of the proposed system can be increased by connecting more PV/wind modules through their wave-shaping circuits in parallel with the other modules. The details of the operating principles, the system configurations, and the design considerations are described. The effectiveness of the proposed CSI is demonstrated by simulation results.

  15. OPERATION & CONTROL OF SMART GRID CONNECTED PV- FC HYBRID POWER SYSTEMD.

    Directory of Open Access Journals (Sweden)

    Saritha(M tech

    2014-08-01

    Full Text Available This paper presents a method to operate and control a grid connected hybrid power system. The hybrid system composed of a Photovoltaic (PV array and a Proton exchange membrane fuel cell (PEMFC is considered. The PV array normally uses a maximum power point tracking (MPPT technique to continuously deliver the highest power to the load when variations in irradiation and temperature occur, which make it become an uncontrollable source. In coordination with PEMFC, the hybrid system output power becomes controllable. Two operation modes, the unit-power control (UPC mode and the feeder-flow control (FFC mode, can be applied to the hybrid system. The coordination of two control modes, the coordination of the PV array and the PEMFC in the hybrid system, and the determination of reference parameters are presented. The proposed operating strategy with a flexible operation mode change always operates the PV array at maximum output power and the PEMFC in its high efficiency performance band, thus improving the performance of system operation, enhancing system stability, and decreasing the number of operating mode changes

  16. PLL Based Energy Efficient PV System with Fuzzy Logic Based Power Tracker for Smart Grid Applications.

    Science.gov (United States)

    Rohini, G; Jamuna, V

    This work aims at improving the dynamic performance of the available photovoltaic (PV) system and maximizing the power obtained from it by the use of cascaded converters with intelligent control techniques. Fuzzy logic based maximum power point technique is embedded on the first conversion stage to obtain the maximum power from the available PV array. The cascading of second converter is needed to maintain the terminal voltage at grid potential. The soft-switching region of three-stage converter is increased with the proposed phase-locked loop based control strategy. The proposed strategy leads to reduction in the ripple content, rating of components, and switching losses. The PV array is mathematically modeled and the system is simulated and the results are analyzed. The performance of the system is compared with the existing maximum power point tracking algorithms. The authors have endeavored to accomplish maximum power and improved reliability for the same insolation of the PV system. Hardware results of the system are also discussed to prove the validity of the simulation results.

  17. PLL Based Energy Efficient PV System with Fuzzy Logic Based Power Tracker for Smart Grid Applications

    Directory of Open Access Journals (Sweden)

    G. Rohini

    2016-01-01

    Full Text Available This work aims at improving the dynamic performance of the available photovoltaic (PV system and maximizing the power obtained from it by the use of cascaded converters with intelligent control techniques. Fuzzy logic based maximum power point technique is embedded on the first conversion stage to obtain the maximum power from the available PV array. The cascading of second converter is needed to maintain the terminal voltage at grid potential. The soft-switching region of three-stage converter is increased with the proposed phase-locked loop based control strategy. The proposed strategy leads to reduction in the ripple content, rating of components, and switching losses. The PV array is mathematically modeled and the system is simulated and the results are analyzed. The performance of the system is compared with the existing maximum power point tracking algorithms. The authors have endeavored to accomplish maximum power and improved reliability for the same insolation of the PV system. Hardware results of the system are also discussed to prove the validity of the simulation results.

  18. A New Control Method to Mitigate Power Fluctuations for Grid Integrated PV/Wind Hybrid Power System Using Ultracapacitors

    Science.gov (United States)

    Jayalakshmi, N. S.; Gaonkar, D. N.

    2016-08-01

    The output power obtained from solar-wind hybrid system fluctuates with changes in weather conditions. These power fluctuations cause adverse effects on the voltage, frequency and transient stability of the utility grid. In this paper, a control method is presented for power smoothing of grid integrated PV/wind hybrid system using ultracapacitors in a DC coupled structure. The power fluctuations of hybrid system are mitigated and smoothed power is supplied to the utility grid. In this work both photovoltaic (PV) panels and the wind generator are controlled to operate at their maximum power point. The grid side inverter control strategy presented in this paper maintains DC link voltage constant while injecting power to the grid at unity power factor considering different operating conditions. Actual solar irradiation and wind speed data are used in this study to evaluate the performance of the developed system using MATLAB/Simulink software. The simulation results show that output power fluctuations of solar-wind hybrid system can be significantly mitigated using the ultracapacitor based storage system.

  19. PV-Powered CoMP-Based Green Cellular Networks with a Standby Grid Supply

    Directory of Open Access Journals (Sweden)

    Abu Jahid

    2017-01-01

    Full Text Available This paper proposes a novel framework for PV-powered cellular networks with a standby grid supply and an essential energy management technique for achieving envisaged green networks. The proposal considers an emerging cellular network architecture employing two types of coordinated multipoint (CoMP transmission techniques for serving the subscribers. Under the proposed framework, each base station (BS is powered by an individual PV solar energy module having an independent storage device. BSs are also connected to the conventional grid supply for meeting additional energy demand. We also propose a dynamic inter-BS solar energy sharing policy through a transmission line for further greening the proposed network by minimizing the consumption from the grid supply. An extensive simulation-based study in the downlink of a Long-Term Evolution (LTE cellular system is carried out for evaluating the energy efficiency performance of the proposed framework. System performance is also investigated for identifying the impact of various system parameters including storage factor, storage capacity, solar generation capacity, transmission line loss, and different CoMP techniques.

  20. Break-even analysis for the storage of PV in power distribution grids

    NARCIS (Netherlands)

    Nykamp, Stefan; Bakker, Vincent; Molderink, Albert; Hurink, Johann L.; Smit, Gerardus Johannes Maria

    2014-01-01

    The integration of renewable energy systems poses major challenges on distribution grid operators. Because of the strong growth rates of the installation of photovoltaic (PV) and wind generators, huge needs for reinforcements in grids are expected. Next to conventional reinforcements (with additiona

  1. Power Quality Experimental Analysis on Rural Home Grid-Connected PV Systems

    Directory of Open Access Journals (Sweden)

    Rita Jorge Cerqueira Pinto

    2015-01-01

    Full Text Available Microgeneration is the small-scale generation of heat or electric power or both, by individuals or buildings to meet their own needs. Recently, microgeneration is being regarded as a means to decentralize the power production of renewable energies, reducing the impacts on the grid caused by unexpected energy demands. Given the increase in microgeneration facilities, determining the quantity of energy produced and the power quality assumes growing importance in low, medium, or high voltage facilities. This paper presents a power quality analysis of two different facilities with photovoltaic generation localized in a rural area of Portugal, describing the voltage and frequency behaviour, the harmonic contents, and the total harmonic distortion. Statistical data are presented regarding the number of voltage events and occurrence of dips and swells in both facilities as a percentage of rated voltage. We conclude that some PV systems can severely affect voltage quality, forcing the grid to work at and even above the maximum voltage standard limit.

  2. Power Hardware-in-the-Loop Evaluation of PV Inverter Grid Support on Hawaiian Electric Feeders: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Austin; Prabakar, Kumaraguru; Nagarajan, Adarsh; Nepal, Shaili; Hoke, Anderson; Asano, Marc; Ueda, Reid; Ifuku, Earle

    2017-05-08

    As more grid-connected photovoltaic (PV) inverters become compliant with evolving interconnections requirements, there is increased interest from utilities in understanding how to best deploy advanced grid-support functions (GSF) in the field. One efficient and cost-effective method to examine such deployment options is to leverage power hardware-in-the-loop (PHIL) testing methods. Two Hawaiian Electric feeder models were converted to real-time models in the OPAL-RT real-time digital testing platform, and integrated with models of GSF capable PV inverters that were modeled from characterization test data. The integrated model was subsequently used in PHIL testing to evaluate the effects of different fixed power factor and volt-watt control settings on voltage regulation of the selected feeders. The results of this study were provided as inputs for field deployment and technical interconnection requirements for grid-connected PV inverters on the Hawaiian Islands.

  3. High-Performance Constant Power Generation in Grid-Connected PV Systems

    DEFF Research Database (Denmark)

    Sangwongwanich, Ariya; Yang, Yongheng; Blaabjerg, Frede

    2016-01-01

    An advanced power control strategy by limiting the maximum feed-in power of PV systems has been proposed, which can ensure a fast and smooth transition between maximum power point tracking and Constant Power Generation (CPG). Regardless of the solar irradiance levels, high-performance and stable...... operation are always achieved by the proposed control strategy. It can regulate the PV output power according to any set-point, and force the PV systems to operate at the left side of the maximum power point without stability problems. Experimental results have verified the effectiveness of the proposed CPG...

  4. PVGIS approach for assessing the performances of the first PV grid-connected power plant in Morocco

    CERN Document Server

    Barhdadi, Abdelfettah

    2012-01-01

    In this paper, we apply the PVGIS method for estimating the performance of the first grid-connected PV micro-power plant in Morocco. PVGIS approach provides analysis and assessment of in-site solar energy resources and predicts with good accuracy the potential of PV systems in term of electricity production. We find that annual total power generation of the micro-power is slightly higher than that initially expected at the installation stage and actually measured. The yearly predicted and measured power production values agree to about 2 %. However, individual monthly production can have larger discrepancy.

  5. Grid integrated distributed PV (GridPV).

    Energy Technology Data Exchange (ETDEWEB)

    Reno, Matthew J.; Coogan, Kyle

    2013-08-01

    This manual provides the documentation of the MATLAB toolbox of functions for using OpenDSS to simulate the impact of solar energy on the distribution system. The majority of the functions are useful for interfacing OpenDSS and MATLAB, and they are of generic use for commanding OpenDSS from MATLAB and retrieving information from simulations. A set of functions is also included for modeling PV plant output and setting up the PV plant in the OpenDSS simulation. The toolbox contains functions for modeling the OpenDSS distribution feeder on satellite images with GPS coordinates. Finally, example simulations functions are included to show potential uses of the toolbox functions. Each function in the toolbox is documented with the function use syntax, full description, function input list, function output list, example use, and example output.

  6. PVGIS approach for assessing the performances of the first PV grid-connected power plant in Morocco

    OpenAIRE

    Barhdadi, Abdelfettah; Bennis, Mouncef

    2012-01-01

    In this paper, we apply the PVGIS method for estimating the performance of the first grid-connected PV micro-power plant in Morocco. PVGIS approach provides analysis and assessment of in-site solar energy resources and predicts with good accuracy the potential of PV systems in term of electricity production. We find that annual total power generation of the micro-power is slightly higher than that initially expected at the installation stage and actually measured. The yearly predicted and mea...

  7. Harmonic Injection-Based Power Fluctuation Control of Three-Phase PV Systems under Unbalanced Grid Voltage Conditions

    Directory of Open Access Journals (Sweden)

    Nian-Cheng Zhou

    2015-02-01

    Full Text Available Unbalanced voltage will inevitably cause power and DC voltage fluctuations in a three-phase PV system. The deterioration of power quality will do great harm to the PV panels and the loads, so it is necessary to suppress the power fluctuations. This paper further explores the coefficients control strategy of PV converters under unbalanced voltage conditions, aiming to suppress power fluctuations by controlling the injection of some specific orders of current harmonics into the grid. In order to achieve this, the current reference of the PV inverter has been changed by bringing in two control coefficients, and the expression of each order of the current harmonics has been deduced. Based on the standards of PV systems, the regions from which the coefficients can be selected are determined. Then, by tuning these coefficients in the feasible regions, the output parameters (power fluctuation, current THD and odd harmonics can be controlled precisely. The model of this method is built and simulated in PSCAD/EMTDC, and as a result, it is shown that the power fluctuations can be restricted according to different power quality requirements.

  8. Comparison of Different MPPT Algorithms with a Proposed One Using a Power Estimator for Grid Connected PV Systems

    Directory of Open Access Journals (Sweden)

    Manel Hlaili

    2016-01-01

    Full Text Available Photovoltaic (PV energy is one of the most important energy sources since it is clean and inexhaustible. It is important to operate PV energy conversion systems in the maximum power point (MPP to maximize the output energy of PV arrays. An MPPT control is necessary to extract maximum power from the PV arrays. In recent years, a large number of techniques have been proposed for tracking the maximum power point. This paper presents a comparison of different MPPT methods and proposes one which used a power estimator and also analyses their suitability for systems which experience a wide range of operating conditions. The classic analysed methods, the incremental conductance (IncCond, perturbation and observation (P&O, ripple correlation (RC algorithms, are suitable and practical. Simulation results of a single phase NPC grid connected PV system operating with the aforementioned methods are presented to confirm effectiveness of the scheme and algorithms. Simulation results verify the correct operation of the different MPPT and the proposed algorithm.

  9. Regional PV power estimation and forecast to mitigate the impact of high photovoltaic penetration on electric grid.

    Science.gov (United States)

    Pierro, Marco; De Felice, Matteo; Maggioni, Enrico; Moser, David; Perotto, Alessandro; Spada, Francesco; Cornaro, Cristina

    2017-04-01

    The growing photovoltaic generation results in a stochastic variability of the electric demand that could compromise the stability of the grid and increase the amount of energy reserve and the energy imbalance cost. On regional scale, solar power estimation and forecast is becoming essential for Distribution System Operators, Transmission System Operator, energy traders, and aggregators of generation. Indeed the estimation of regional PV power can be used for PV power supervision and real time control of residual load. Mid-term PV power forecast can be employed for transmission scheduling to reduce energy imbalance and related cost of penalties, residual load tracking, trading optimization, secondary energy reserve assessment. In this context, a new upscaling method was developed and used for estimation and mid-term forecast of the photovoltaic distributed generation in a small area in the north of Italy under the control of a local DSO. The method was based on spatial clustering of the PV fleet and neural networks models that input satellite or numerical weather prediction data (centered on cluster centroids) to estimate or predict the regional solar generation. It requires a low computational effort and very few input information should be provided by users. The power estimation model achieved a RMSE of 3% of installed capacity. Intra-day forecast (from 1 to 4 hours) obtained a RMSE of 5% - 7% while the one and two days forecast achieve to a RMSE of 7% and 7.5%. A model to estimate the forecast error and the prediction intervals was also developed. The photovoltaic production in the considered region provided the 6.9% of the electric consumption in 2015. Since the PV penetration is very similar to the one observed at national level (7.9%), this is a good case study to analyse the impact of PV generation on the electric grid and the effects of PV power forecast on transmission scheduling and on secondary reserve estimation. It appears that, already with 7% of PV

  10. Power Quality Improvement of an Off-Grid Versatile PV System

    Directory of Open Access Journals (Sweden)

    D. Bini Sherlin

    2014-03-01

    Full Text Available Photovoltaic systems are trusted to be the future wave of alternate source of energy. This paper presents a versatile PV generation system that enables to supply both AC as well as DC loads in addition to providing back-up supply for the AC load. The back-up supply is provided by charging a battery. The inverter is controlled using hysteresis current control method that contains the current ripple within the two hysteresis bands. Thereby the harmonic content in the inverter output is lowered and also provides quality power. The performance of the proposed system is verified through simulation.

  11. Investigating the Impact of Shading Effect on the Characteristics of a Large-Scale Grid-Connected PV Power Plant in Northwest China

    OpenAIRE

    2014-01-01

    Northwest China is an ideal region for large-scale grid-connected PV system installation due to its abundant solar radiation and vast areas. For grid-connected PV systems in this region, one of the key issues is how to reduce the shading effect as much as possible to maximize their power generation. In this paper, a shading simulation model for PV modules is established and its reliability is verified under the standard testing condition (STC) in laboratory. Based on the investigation result ...

  12. Optimal Power Scheduling for a Grid-Connected Hybrid PV-Wind-Battery Microgrid System

    DEFF Research Database (Denmark)

    Hernández, Adriana Carolina Luna; Aldana, Nelson Leonardo Diaz; Savaghebi, Mehdi

    2016-01-01

    In this paper, a lineal mathematical model is proposed to schedule optimally the power references of the distributed energy resources in a grid-connected hybrid PVwind-battery microgrid. The optimization of the short term scheduling problem is addressed through a mixed-integer linear programming...... mathematical model, wherein the cost of energy purchased from the main grid is minimized and profits for selling energy generated by photovoltaic arrays are maximized by considering both physical constraints and requirements for a feasible deployment in the real system. The optimization model is tested...

  13. Investigating the Impact of Shading Effect on the Characteristics of a Large-Scale Grid-Connected PV Power Plant in Northwest China

    Directory of Open Access Journals (Sweden)

    Yunlin Sun

    2014-01-01

    Full Text Available Northwest China is an ideal region for large-scale grid-connected PV system installation due to its abundant solar radiation and vast areas. For grid-connected PV systems in this region, one of the key issues is how to reduce the shading effect as much as possible to maximize their power generation. In this paper, a shading simulation model for PV modules is established and its reliability is verified under the standard testing condition (STC in laboratory. Based on the investigation result of a 20 MWp grid-connected PV plant in northwest China, the typical shading phenomena are classified and analyzed individually, such as power distribution buildings shading and wire poles shading, plants and birds droppings shading, and front-row PV arrays shading. A series of experiments is also conducted on-site to evaluate and compare the impacts of different typical shading forms. Finally, some feasible solutions are proposed to avoid or reduce the shading effect of PV system during operation in such region.

  14. Grid-Connected Fuzzy-PID Control of PV Power Generation System%光伏发电系统的并网模糊PID控制

    Institute of Scientific and Technical Information of China (English)

    贺运胜

    2013-01-01

    在三相两级式并网逆变器数学模型的基础上,将模糊PID控制策略引入光伏发电系统的并网控制中.通过数字仿真和物理仿真表明模糊控制与PID控制相结合的模糊PID控制,改善了光伏系统并网控制的动态过程,能够实现光伏系统的平滑并网.%ied in the grid control of PV system in this paper. The digital simulation and physical simulation show that the fuzzy-PID control strategy can improve the PV system grid control dynamic process and realize the smooth connection of the PV system with the power grid.

  15. Voltage rise mitigation for solar PV integration at LV grids

    DEFF Research Database (Denmark)

    Yang, Guangya; Marra, Francesco; Juamperez Goñi, Miguel Angel

    2015-01-01

    Solar energy from photovoltaic (PV) is among the fastest developing renewable energy systems worldwide. Driven by governmental subsidies and technological development, Europe has seen a fast expansion of solar PV in the last few years. Among the installed PV plants, most of them are situated...... at the distribution systems and bring various operational challenges such as power quality and power flow management. The paper discusses the modelling requirements for PV system integration studies, as well as the possible techniques for voltage rise mitigation at low voltage (LV) grids for increasing PV penetration...

  16. Development of a low-cost integrated 20-kW ac solar tracking sub- array for grid-connected PV power system applications. Phase 1, Annual technical report, 11 July 1995--31 July 1996

    Energy Technology Data Exchange (ETDEWEB)

    Stern, M.; West, R.; Fourer, G.; Whalen, W.; Van Loo, M.; Duran, G. [Utility Power Group, Chatsworth, CA (United States)

    1997-06-01

    The overall goal of this effort is to reduce the installed cost of utility scale grid connected photovoltaic power systems. The focus of the effort is on ``BOS`` (Balance-Of-System) component manufacturing technology, which essentially involves all PV power system engineering, manufacturing, assembly and construction tasks from the receipt of a PV module to the deliver of grid connected electricity.

  17. Monitoring and Analysis of Two Grid Connected PV Systems

    OpenAIRE

    2013-01-01

    International audience; In this paper, two grid connected photovoltaic systems are studied and monitored for fault detection ad predictive reliability. The first PV grid, is at CNRS-PROMES laboratory in Perpignan, built in 2001 with 3 PV arrays named "Shed","Brise soleil","Mur rideau") connected to the grid thanks to many inverter of different power (3 of 4KWC and 2 of 2.5KWC). The second one is at CNRS-LAAS in Toulouse with a power of 100kWc. It is composed of a facade of 36kWc PV array and ...

  18. PV power plants

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-07-01

    Within the international seminar of the Ostbayerisches Technologie-Transfer-Institut e.V. (OTTI) at 11th June, 2012 in Munich (Federal Republic of Germany), the following lectures were held: (1) Technical due diligence (Dietmar Obst); (2) Certification / rating system for large PV plants (Robert Pfatischer); (3) O and M requirements (Lars Rulf); (4) IR photography for large scale systems (Bernhard Weinreich); (5) New market models for PV systems - direct marketing and sales of PV electricity (Martin Schneider); (6) Needs and benefits for plant certification for grid connection and operation (Christoph Luetke-Lengerich); (7) Lare volume module testing / Screening in the field and workshop (Semir Merzoug); (8) Dismantling costs of large scale PV plants (Siegfried Schimpf).

  19. Methods for the Optimal Design of Grid-Connected PV Inverters

    DEFF Research Database (Denmark)

    Koutroulis, Eftichios; Blaabjerg, Frede

    2011-01-01

    and the efficient processing of this power by the DC/AC inverter. In this paper two new methods are presented for the optimal design of a PV inverter power section, output filter and MPPT control strategy. The influences of the electric grid regulations and standards as well as the PV array operational......The DC/AC inverters are used in grid-connected PV energy production systems as the power processing interface between the PV energy source and the electric grid. The energy injected into the electric grid by the PV installation depends on the amount of power extracted from the PV power source...... characteristics on the design of grid-connected PV inverters have been considered. The proposed methods have been applied for the optimal design of PV inverters installed at various sites in Europe. The simulation results verify that the proposed optimization techniques enable the maximization of the PV energy...

  20. Development of a low cost integrated 15 kW A.C. solar tracking sub-array for grid connected PV power system applications

    Science.gov (United States)

    Stern, M.; West, R.; Fourer, G.; Whalen, W.; Van Loo, M.; Duran, G.

    1997-02-01

    Utility Power Group has achieved a significant reduction in the installed cost of grid-connected PV systems. The two part technical approach focused on 1) The utilization of a large area factory assembled PV panel, and 2) The integration and packaging of all sub-array power conversion and control functions within a single factory produced enclosure. Eight engineering prototype 15kW ac single axis solar tracking sub-arrays were designed, fabricated, and installed at the Sacramento Municipal Utility District's Hedge Substation site in 1996 and are being evaluated for performance and reliability. A number of design enhancements will be implemented in 1997 and demonstrated by the field deployment and operation of over twenty advanced sub-array PV power systems.

  1. Predictability of PV power grid performance on insular sites without weather stations: use of artificial neural networks

    CERN Document Server

    Voyant, Cyril; Paoli, Christophe; Nivet, Marie Laure; Poggi, Philippe; Haurant, P; 10.4229/24thEUPVSEC2009-5BV.2.35

    2010-01-01

    The official meteorological network is poor on the island of Corsica: only three sites being about 50 km apart are equipped with pyranometers which enable measurements by hourly and daily step. These sites are Ajaccio (41\\degree 55'N and 8\\degree 48'E, seaside), Bastia (42\\degree 33'N, 9\\degree 29'E, seaside) and Corte (42\\degree 30'N, 9\\degree 15'E average altitude of 486 meters). This lack of weather station makes difficult the predictability of PV power grid performance. This work intends to study a methodology which can predict global solar irradiation using data available from another location for daily and hourly horizon. In order to achieve this prediction, we have used Artificial Neural Network which is a popular artificial intelligence technique in the forecasting domain. A simulator has been obtained using data available for the station of Ajaccio that is the only station for which we have a lot of data: 16 years from 1972 to 1987. Then we have tested the efficiency of this simulator in two places w...

  2. Online Grid Measurement and ENS Detection for PV Inverter Running on Highly Inductive Grid

    DEFF Research Database (Denmark)

    Timbus, Adrian Vasile; Teodorescu, Remus; Blaabjerg, Frede;

    2004-01-01

    Photovoltaic (PV) and other sources of renewable energy are being used increasingly in grid-connected systems, for which stronger power quality requirements are being issued. Continuous grid monitoring should be considered so as to provide safe connections and disconnections from the grid....... This letter gives an overview of the methods used for online grid measurement with PV inverters. Emphasis is placed on a method based on the injection of a noncharacteristic harmonic in the grid. Since this injection is regarded as a disturbance for the grid, different issues, i.e., the influence on total...

  3. A Simple Power Management Scheme with Enhanced Stability for a Solar PV/Wind/Fuel Cell/Grid Fed Hybrid Power Supply Designed for Industrial Loads

    Directory of Open Access Journals (Sweden)

    S. Saravanan

    2014-01-01

    Full Text Available This paper proposes a new power conditioner topology with an intelligent power management controller that integrates multiple renewable energy sources such as solar energy, wind energy, and fuel cell energy with battery and AC grid supply as backup to make the best use of their operating characteristics with better reliability than that could be obtained by single renewable energy source based power supply. The proposed embedded controller is programmed to perform MPPT for solar PV panel and WTG, SOC estimation and battery, maintaining a constant voltage at PCC and power flow control by regulating the reference currents of the controller in an instantaneous basis. The instantaneous variation in reference currents of the controller enhances the controller response as it accommodates the effect of continuously varying solar insolation and wind speed in the power management. It also prioritizes the sources for consumption to achieve maximum usage of green energy than grid energy. The simulation results of the proposed power management system with real-time solar radiation and wind velocity data collected from solar centre, KEC, and experimental results for a sporadically varying load demand are presented in this paper and the results are encouraging from reliability and stability perspectives.

  4. Design of an off-grid hybrid PV/wind power system for remote mobile base station: A case study

    Directory of Open Access Journals (Sweden)

    Mulualem T. Yeshalem

    2017-01-01

    Full Text Available There is a clear challenge to provide reliable cellular mobile service at remote locations where a reliable power supply is not available. So, the existing Mobile towers or Base Transceiver Station (BTSs uses a conventional diesel generator with backup battery banks. This paper presents the solution to utilizing a hybrid of photovoltaic (PV solar and wind power system with a backup battery bank to provide feasibility and reliable electric power for a specific remote mobile base station located at west arise, Oromia. All the necessary modeling, simulation, and techno-economic evaluation are carried out using Hybrid Optimization Model for Electric Renewable (HOMER software. The best optimal system configurations namely PV/Battery and PV/Wind/Battery hybrid systems are compared with the conventional stand-alone diesel generator (DG system. Findings indicated that PV array and battery is the most economically viable option with the total net present cost (NPC of $\\$$57,508 and per unit cost of electricity (COE of $\\$$0.355. Simulation results show that the hybrid energy systems can minimize the power generation cost significantly and can decrease CO2 emissions as compared to the traditional diesel generator only. The sensitivity analysis is also carried out to analysis the effects of probable variation in solar radiation, wind speed, diesel price and average annual energy usage of the system load in the optimal system configurations.

  5. Hybrid wind-PV grid connected power station case study: Al Tafila, Jordan

    Energy Technology Data Exchange (ETDEWEB)

    El-Tous, Yousif [Department of Electrical Engineering/Faculty of Engineering Technology/ Al-Balqa' Applied University, Amman, P.O.Box (15008), Marka Ashamalia (Jordan); Al-Battat, Saleh [Department of substation maintenance and protection, National Electric Power Company (NEPCO), Amman (Jordan); Abdel Hafith, Sandro [Department of technical support and project supervision/Integrated power systems co., Amman (Jordan)

    2012-07-01

    In this paper, we are providing an attempt to highlight the importance of renewable energy, more specifically, the one produced from a wind-solar hybrid system. This purpose will be achieved through providing a detailed case study for such system that would be applied in Al-Tafila, Jordan. First and foremost site assessment has been conducted based on an intensive literature review for the data available regarding the availability of wind and solar energy in Jordan and resulted in the selection of Al-Tafila 2 district as the best option among all. Then, the components of the power station and its size have been selected based on specific criteria that make the station as much efficient and competitive as possible. To obtain the output of the different components with respect to the demand for a period of 25 years, a system model was built using HOMER. Finally, the total capital cost of the system was calculated and resulted to be (63400168) $ and with a cost of energy of (0.053) $/kWh which is a very competitive and feasible cost compared to similar international projects and to the conventional energy price.

  6. Hybrid wind-PV grid connected power station case study: Al Tafila, Jordan

    Directory of Open Access Journals (Sweden)

    Yousif El-Tous, Saleh Al-Battat, Sandro Abdel Hafith

    2012-01-01

    Full Text Available In this paper, we are providing an attempt to highlight the importance of renewable energy, more specifically, the one produced from a wind-solar hybrid system. This purpose will be achieved through providing a detailed case study for such system that would be applied in Al-TafilaJordan. First and foremost site assessment has been conducted based on an intensive literature review for the data available regarding the availability of wind and solar energy in Jordan and resulted in the selection of Al-Tafila 2 district as the best option among all. Then, the components of the power station and its size have been selected based on specific criteria that make the station as much efficient and competitive as possible. To obtain the output of the different components with respect to the demand for a period of 25 years, a system model was built using HOMER. Finally, the total capital cost of the system was calculated and resulted to be (63400168 $ and with a cost of energy of (0.053 $/kWh which is a very competitive and feasible cost compared to similar international projects and to the conventional energy price.

  7. Grid Integrated Distributed PV (GridPV) Version 2.

    Energy Technology Data Exchange (ETDEWEB)

    Reno, Matthew J.; Coogan, Kyle

    2014-12-01

    This manual provides the documentation of the MATLAB toolbox of functions for using OpenDSS to simulate the impact of solar energy on the distribution system. The majority of the functio ns are useful for interfacing OpenDSS and MATLAB, and they are of generic use for commanding OpenDSS from MATLAB and retrieving information from simulations. A set of functions is also included for modeling PV plant output and setting up the PV plant in th e OpenDSS simulation. The toolbox contains functions for modeling the OpenDSS distribution feeder on satellite images with GPS coordinates. Finally, example simulations functions are included to show potential uses of the toolbox functions. Each function i n the toolbox is documented with the function use syntax, full description, function input list, function output list, example use, and example output.

  8. Optimal Parameter Selection for Support Vector Machine Based on Artificial Bee Colony Algorithm: A Case Study of Grid-Connected PV System Power Prediction

    Directory of Open Access Journals (Sweden)

    Xiang-ming Gao

    2017-01-01

    Full Text Available Predicting the output power of photovoltaic system with nonstationarity and randomness, an output power prediction model for grid-connected PV systems is proposed based on empirical mode decomposition (EMD and support vector machine (SVM optimized with an artificial bee colony (ABC algorithm. First, according to the weather forecast data sets on the prediction date, the time series data of output power on a similar day with 15-minute intervals are built. Second, the time series data of the output power are decomposed into a series of components, including some intrinsic mode components IMFn and a trend component Res, at different scales using EMD. The corresponding SVM prediction model is established for each IMF component and trend component, and the SVM model parameters are optimized with the artificial bee colony algorithm. Finally, the prediction results of each model are reconstructed, and the predicted values of the output power of the grid-connected PV system can be obtained. The prediction model is tested with actual data, and the results show that the power prediction model based on the EMD and ABC-SVM has a faster calculation speed and higher prediction accuracy than do the single SVM prediction model and the EMD-SVM prediction model without optimization.

  9. Promotional drivers for grid-connected PV

    Energy Technology Data Exchange (ETDEWEB)

    Lopez Polo, A.; Hass, R.; Suna, D.

    2009-03-15

    This report for the International Energy Agency (IEA) made by Task 10 of the Photovoltaic Power Systems (PVPS) programme takes a look at promotional measures for grid-connected photovoltaic systems. The mission of the Photovoltaic Power Systems Programme is to enhance the international collaboration efforts which accelerate the development and deployment of photovoltaic solar energy. The objective of Task 10 is stated as being to enhance the opportunities for wide-scale, solution-oriented application of photovoltaics in the urban environment. The paper discusses the core objective of this study which was to analyse the success of various governmental regulatory programs and governmental and non-governmental marketing programs for grid-connected PV systems. To meet this objective, a review of the most important past and current programs around the world was conducted. The theoretical bases of supply and demand are explained and the types of existing strategies are documented in a second Section. In Chapter 3, various programs around the world are described. Chapter 4 focuses on defining success criteria which will be used for the analysis of the programs. Finally, the major conclusions drawn complete this analysis.

  10. Costs of Residential Solar PV Plants in Distribution Grid Networks

    DEFF Research Database (Denmark)

    Kjær, Søren Bækhøj; Yang, Guangya; Ipsen, Hans Henrik

    2015-01-01

    In this article we investigate the impact of residential solar PV plants on energy losses in distribution networks and their impact on distribution transformers lifetime. Current guidelines in Denmark states that distribution transformers should not be loaded with more than 67% solar PV power...... to avoid accelerated loss of life. If a solar PV plant causes this limit to be exceeded, the particular owner has to pay for upgrading the transformer. Distribution Network Operators also charge an annual tariff from the solar PV plants to cover the expenses to keep the grid capacity available, the so...... called “Availability Tariff”. According to the Danish Energy Regulatory Authority, the Availability Tariff must cover the exact expenses, with energy savings etc. from the solar PV plants taken into consideration. Our conclusion is that a distribution network, which represents a typical residential...

  11. Costs of Residential Solar PV Plants in Distribution Grid Networks

    DEFF Research Database (Denmark)

    Kjær, Søren Bækhøj; Yang, Guangya; Ipsen, Hans Henrik

    2015-01-01

    In this article we investigate the impact of residential solar PV plants on energy losses in distribution networks and their impact on distribution transformers lifetime. Current guidelines in Denmark states that distribution transformers should not be loaded with more than 67% solar PV power...... called “Availability Tariff”. According to the Danish Energy Regulatory Authority, the Availability Tariff must cover the exact expenses, with energy savings etc. from the solar PV plants taken into consideration. Our conclusion is that a distribution network, which represents a typical residential...... to avoid accelerated loss of life. If a solar PV plant causes this limit to be exceeded, the particular owner has to pay for upgrading the transformer. Distribution Network Operators also charge an annual tariff from the solar PV plants to cover the expenses to keep the grid capacity available, the so...

  12. Stability of Grid-Connected PV Inverters with Large Grid Impedance Variation

    DEFF Research Database (Denmark)

    Liserre, Marco; Teodorescu, Remus; Blaabjerg, Frede

    2004-01-01

    Photovoltaic (PV) inverters used in dispersed power generation of houses in the range of 1-5 kW are currently available from several manufactures. However, large grid impedance variation is challenging the control and the grid filter design in terms of stability. In fact the PV systems are well...... suited for loads connected in a great distance to the transformer (long wires) and the situation becomes even more difficult in low-developed remote areas characterized by low power transformers and long distribution wires with high grid impedance. Hence a theoretical analysis is needed because the grid...... the design of resonant controllers adopted to mitigate the effect of the grid harmonic distortion on the grid current. In the high frequency range the grid impedance influence the frequency characteristic of the filter and the design of passive or active damping (to ensure stability) becomes more difficult...

  13. Indirect adaptive soft computing based wavelet-embedded control paradigms for WT/PV/SOFC in a grid/charging station connected hybrid power system.

    Science.gov (United States)

    Mumtaz, Sidra; Khan, Laiq; Ahmed, Saghir; Bader, Rabiah

    2017-01-01

    This paper focuses on the indirect adaptive tracking control of renewable energy sources in a grid-connected hybrid power system. The renewable energy systems have low efficiency and intermittent nature due to unpredictable meteorological conditions. The domestic load and the conventional charging stations behave in an uncertain manner. To operate the renewable energy sources efficiently for harvesting maximum power, instantaneous nonlinear dynamics should be captured online. A Chebyshev-wavelet embedded NeuroFuzzy indirect adaptive MPPT (maximum power point tracking) control paradigm is proposed for variable speed wind turbine-permanent synchronous generator (VSWT-PMSG). A Hermite-wavelet incorporated NeuroFuzzy indirect adaptive MPPT control strategy for photovoltaic (PV) system to extract maximum power and indirect adaptive tracking control scheme for Solid Oxide Fuel Cell (SOFC) is developed. A comprehensive simulation test-bed for a grid-connected hybrid power system is developed in Matlab/Simulink. The robustness of the suggested indirect adaptive control paradigms are evaluated through simulation results in a grid-connected hybrid power system test-bed by comparison with conventional and intelligent control techniques. The simulation results validate the effectiveness of the proposed control paradigms.

  14. Environmental life cycle assessment of a large-scale grid-connected PV power plant. Case study Moura 62 MW PV power plant

    Energy Technology Data Exchange (ETDEWEB)

    Suomalainen, Kiti

    2006-01-15

    An environmental life cycle assessment has been conducted for a 62 MW grid-connected photovoltaic installation to study the role of BOS components in the total environmental load. Also the influence of the current electricity supply has been investigated. For an alternative approach a net output approach has been used, where all electricity requirements are supplied by the photovoltaic installation itself. The components taken into account are monocrystalline silicon cells in frameless modules, steel support structures in concrete foundations, inverters, transformers, cables, transports and construction of roads and buildings. For stationary inert products without intrinsic energy requirements, such as cables, inverters, support structures etc., only raw material acquisition and processing are taken into account, since they are considered the most dominant stages in the life cycle. The results confirm a minor environmental load from BOS components compared to the module life cycle, showing approximately ten to twenty percent impact of the total. Uncertainties lie in the approximations for electronic devices as well as in the emissions from silicon processing. Concerning the electricity supply, the results differ considerably depending on which system perspective is used. In the net output approach the impacts decrease with approximately ninety percent from the traditional approach. Some increases are also shown in toxicity categories due to the increased module production needed for the enlargement of the installation.

  15. PV-HYBRID and MINI-GRID. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    Within the 3rd European Conference at the Centre de Congres in Aix en Provence (France) between 11th and 12th May, 2006, the following lessons were held: (1) Small electric networks: European drivers and projects for the integration of RES and DG into the electricity grids of the future (Manuel Sanchez-Jimenez); (2) PV hybrid system within mini grids - IEA PVPS programme (Meuch Konraf); (3) Renewables for the developing world (Alvaro Ponce Plaza); (4) Rural electicity supply using photovoltaic / - Diesel hybrid systems: Attractive for investors in the renewable energy sector? (Andreas Hahn); (5) Economic analysis of stand-alone and grid-connected photovoltaic systems under current tariff structure of Taiwan (Yaw-Juen Wang); (6) Using wind-PV-diesel hybrid system for electrification of remote village in Western Libya (N.M. Kreama); (7) Venezuela's renewable energy program for small towns and rural areas ''Sembrando Luz'' (Jorge Torres); (8) AeroSmart5, the professional, sysem-compatible small-scale wind energy converter will be tested in field tests (Fabian Jochem); (9) Lifetime, test procedures and recommendations for optimal operating strategies for lead-acid-batteries in renewable energy systems - A survey on results from European projects from the 5th framework programme (Rudi Kaiser); (10) Prototype of a reversible fuel cell system for autonomous power supplies (Tom Smolinska); (11) Interconnection management in microgrids (Michel Vandenbergh); (12) Control strategy for a small-scale stand-alone power system based on renewable energy and hydrogen (Harald Miland); (13) Standard renewable electricity supply for people in rural areas - mini-grids in western provinces of China (Michael Wollny); (14) The Brava island a ''100% renewable energy'' project (Jean-Christian Marcel); (15) Breakthrough to a new era of PV-hybrid systems with the help of standardised components communication? (Michael Mueller); (16) Standardized

  16. Sizing aspects of a small scale grid connected PV system

    Energy Technology Data Exchange (ETDEWEB)

    Bartha, S.; Teodoreanu, D.I.; Teodoreanu, M.; Negreanu, C. [I.C.P.E.-New Energy Sources Laboratory (NESL), Bucharest (Romania); Farkas, I.; Seres, I. [Szent Istvan University, Goedoelloe (Hungary). Department of Physics and Process Control

    2008-07-01

    Photovoltaics can be used in grid connected mode in two ways: as array installed at the end use site, such as on rooftops, or as utility-scale generating stations. The present paper describes a small-scale grid connected Photovoltaic system. The paper starts with the structure and characterization of the system. The principal technical parameter data are also presented. The used monitoring parameters indicate the principal meteorological data, air temperature and solar radiation data for the location sited at Agigea, at the Black Sea and the produced energy by the PV modules. The present application is made by 1 subsystem with 1200 Wp power and with the panel inclination possibility, using different type of PV modules. The paper presents a simulation model for this system realized with commercial software packages and with a one self made Matlab model that evaluates the energy balance of the PV system. All the simulation and measurements data are presented. (orig.)

  17. Real Time Photovoltaic Array Simulator for Testing Grid-Connected PV Inverters

    DEFF Research Database (Denmark)

    Sera, Dezso; Valentini, Massimo; Raducu, Alin

    2008-01-01

    In this paper a real time flexible PV array simulator is presented. It is a system that can simulate different PV panel arrays in specific environmental conditions. To evaluate performance of the Maximum Power Point Tracking (MPPT) of grid-connected Photovoltaic (PV) inverters only measurements...

  18. Switching Logic for Converting Off-grid PV Customers to On-grid by Utilizing Off-grid Inverter and Battery

    Science.gov (United States)

    Anishkumar, A. R.; Sreejaya, P.

    2016-12-01

    Kerala is a state in India having a very good potential for solar PV energy production. The domestic customers in Kerala using PV system are approximately 15 % and almost all of them are using the off-grid PV system. When these off grid customers move to on-grid system, off grid system accessories such as inverter and batteries become redundant. In this paper, a switching logic has been developed for the effective utilization of off grid accessories and reducing islanding power loss for on grid customers. An algorithm is proposed for the switching logic and it is verified using simulation results and hardware implementation.

  19. Design optimization of grid-connected PV inverters

    DEFF Research Database (Denmark)

    Koutroulis, Eftichios; Blaabjerg, Frede

    2011-01-01

    The DC/AC inverters are the key elements in grid-connected PV energy production systems. In this paper, new design optimization techniques focused on transformerless (very high efficiency) PV inverters are proposed. They have been developed based on an analysis of the deficiencies of the current......, state-of-the-art PV inverters design technology, which limits the amount of PV energy supplied into the electric grid. The influences of the electric grid regulations and standards and the PV array operational characteristics on the design of grid-connected PV inverters have also been considered....... The simulation results verify that the proposed optimization techniques enable the maximization of the PV energy injected into the electric grid by the optimized PV installation....

  20. Accurate Engineering Model of PV Module and Voltage Range at Maximum Power Point of Grid-Connected PV Inverter%光伏组件精确工程模型及MPP电压范围研究

    Institute of Scientific and Technical Information of China (English)

    王冰清; 曾国宏; 童亦斌; 张勇波

    2013-01-01

    The research on output characteristics of photovoltaic (PV) module is the foundation to determine the voltage range at maximum power point (MPP) of grid-connected PV inverter. The mathematical model of PV module is of high accuracy, however considering such disadvantages of the mathematical model such as concerning in transcendental equation, complex solving process and too much input parameters, it is not suitable for engineering design; the calculation of simplified model of PV module is simple, however by which the output characteristics of PV module under low light condition cannot be accurately described. Based on contrastive analysis on the mathematical model and simplified model, an accurate engineering model of PV module, which is benchmarked in the mathematical model, is proposed. The compensation parameters of the simplified model is fitted and modified, meanwhile both accuracy and complexity of engineering model are taken into account. The MathCad program is utilized to built the simulation model of PV module, and the output results of the simulation model is contrasted with the output of the mathematical model to verify the accuracy of accurate engineering model. Based on the proposed engineering model, through analyzing the impacts of external conditions such as illumination, temperature and so on, the voltage range traced at MPP of grid-connected PV inverter can be accurately determined, and the correctness of this conclusion is validated by experimental results.%光伏并网变流器最大功率点(maximum power point, MPP)电压范围的确定是以组件的输出特性研究为基础的。组件的数学模型精确度较高,但涉及到超越方程,求解复杂且输入参数多,不适用于工程设计。简化模型计算过程简单但不能准确表述弱光条件下的组件输出特性。基于对数学模型及简化模型的对比分析,提出了一种精确的工程模型,该模型以数学模型为基准,对简化模型的

  1. A solar PV augmented hybrid scheme for enhanced wind power generation through improved control strategy for grid connected doubly fed induction generator

    Directory of Open Access Journals (Sweden)

    Adikanda Parida

    2016-12-01

    Full Text Available In this paper, a wind power generation scheme using a grid connected doubly fed induction generator (DFIG augmented with solar PV has been proposed. A reactive power-based rotor speed and position estimation technique with reduced machine parameter sensitivity is also proposed to improve the performance of the DFIG controller. The estimation algorithm is based on model reference adaptive system (MRAS, which uses the air gap reactive power as the adjustable variable. The overall generation reliability of the wind energy conversion system can be considerably improved as both solar and wind energy can supplement each other during lean periods of either of the sources. The rotor-side DC-link voltage and active power generation at the stator terminals of the DFIG are maintained constant with minimum storage battery capacity using single converter arrangement without grid-side converter (GSC. The proposed scheme has been simulated and experimentally validated with a practical 2.5 kW DFIG using dSPACE CP1104 module which produced satisfactory results.

  2. Grid-Tied Photovoltaic Power System

    Science.gov (United States)

    Eichenberg, Dennis J.

    2011-01-01

    A grid-tied photovoltaic (PV) power system is connected directly to the utility distribution grid. Facility power can be obtained from the utility system as normal. The PV system is synchronized with the utility system to provide power for the facility, and excess power is provided to the utility. Operating costs of a PV power system are low compared to conventional power technologies. This method can displace the highest-cost electricity during times of peak demand in most climatic regions, and thus reduce grid loading. Net metering is often used, in which independent power producers such as PV power systems are connected to the utility grid via the customers main service panels and meters. When the PV power system is generating more power than required at that location, the excess power is provided to the utility grid. The customer pays the net of the power purchased when the on-site power demand is greater than the onsite power production, and the excess power is returned to the utility grid. Power generated by the PV system reduces utility demand, and the surplus power aids the community. Modern PV panels are readily available, reliable, efficient, and economical, with a life expectancy of at least 25 years. Modern electronics have been the enabling technology behind grid-tied power systems, making them safe, reliable, efficient, and economical with a life expectancy equal to the modern PV panels. The grid-tied PV power system was successfully designed and developed, and this served to validate the basic principles developed, and the theoretical work that was performed. Grid-tied PV power systems are reliable, maintenance- free, long-life power systems, and are of significant value to NASA and the community. Of particular value are the analytical tools and capabilities that have been successfully developed. Performance predictions can be made confidently for grid-tied PV systems of various scales. The work was done under the NASA Hybrid Power Management (HPM

  3. Evaluation of the Voltage Support Strategies for the Low Voltage Grid Connected PV

    DEFF Research Database (Denmark)

    Demirok, Erhan; Sera, Dezso; Teodorescu, Remus

    2010-01-01

    PVs. In order to increase PV penetration level further, new voltage support control functions for individual inverters are required. This paper investigates distributed reactive power regulation and active power curtailment strategies regarding the development of PV connection capacity by evaluation......Admissible range of grid voltage is one of the strictest constraints for the penetration of distributed photovoltaic (PV) generators especially connection to low voltage (LV) public networks. Voltage limits are usually fulfilled either by network reinforcements or limiting of power injections from...

  4. 多机电力系统中光伏发电厂附加稳定器的设计%Design of astabilizer attached to a grid-connected PV power plant in a multi-machine power system

    Institute of Scientific and Technical Information of China (English)

    杜文娟; 王海风; 曹军

    2011-01-01

    在未来电力系统中,光伏发电厂将是一种重要的可再生电源.光伏发电厂接入未来电力系统将会影响输电系统稳定运行和控制.提出一种多机电力系统中光伏发电厂稳定器的设计新方法.首先搭建接入电网的光伏发电厂局部线性化模型.给出在光伏发电厂接入地点附近线路上发生低频功率振荡与附加稳定器控制的关系.在此局部线性化模型基础上,演示如何使用经典的相位补偿法设计附加稳定器,向线路低频功率振荡提供正阻尼.该方法无需获得和验证全多机电力系统的运行和参数信息,就能进行稳定器的设计,是一种简单、局部化的设计方法.实例分析验证了该方法的有效性,即通过在光伏发电厂上附加稳定器,可以有效帮助提高电力系统的稳定性.%Photovoltaic (PV) generation will be one of the main renewable power sources in future power systems.Grid connection of PV generation can facilitate efficient and large-scale applications,which can affect significantly the operation and control of power transmission in future.This paper presents a novel method to design a stabilizer attached to a grid-connected PV power plant in a multi-machine power system.Firstly in the paper,a localized model of the grid-connected PV power plant is derived.The model gives the relationship between power oscillations along the transmission lines where the PV power plant is connected and the stabilizing control of the stabilizer.Based on the localized model,it is demonstrated that the conventional phase compensation method can be applied to design the stabilizer to provide positive damping to the line power oscillations.Hence the proposed application of the phase compensation method to design the stabilizer is both simple and localized,as it does not need to obtain and validate the information and parameters of the entire multi-machine power system.In the paper,an example fourmachine power system

  5. PV power forecast using a nonparametric PV model

    OpenAIRE

    Almeida, Marcelo Pinho; Perpiñan Lamigueiro, Oscar; Narvarte Fernández, Luis

    2015-01-01

    Forecasting the AC power output of a PV plant accurately is important both for plant owners and electric system operators. Two main categories of PV modeling are available: the parametric and the nonparametric. In this paper, a methodology using a nonparametric PV model is proposed, using as inputs several forecasts of meteorological variables from a Numerical Weather Forecast model, and actual AC power measurements of PV plants. The methodology was built upon the R environment and uses Quant...

  6. Implementation and Test of an Online Embedded Grid Impedance Estimation Technique for PV Inverters

    DEFF Research Database (Denmark)

    Asiminoaei, Lucian; Teodorescu, Remus; Blaabjerg, Frede

    2005-01-01

    New and stronger power quality requirements are issued due to the increased amount of photovoltaic (PV) installations. In this paper different methods are used for continuous grid monitoring in PV inverters. By injecting a noncharacteristic harmonic current and measuring the grid voltage response...... it is possible to evaluate the grid impedance directly by the PV inverter, providing a fast and low-cost implementation. This principle theoretically provides an accurate result of the grid impedance but when using it in the context of PV integration, different implementation issues strongly affect the quality...... of the results. This paper also presents a new impedance estimation method including typical implementation problems encountered, and it also presents adopted solutions for online grid impedance measurement. Practical tests on an existing PV inverter validate the chosen solution....

  7. Overcoming PV grid issues in the urban areas

    Energy Technology Data Exchange (ETDEWEB)

    Ehara, T.

    2009-10-15

    This report for the International Energy Agency (IEA) made by Task 10 of the Photovoltaic Power Systems (PVPS) programme takes a look at grid issues in urban photovoltaic electricity and how to overcome them. The mission of the Photovoltaic Power Systems Programme is to enhance the international collaboration efforts which accelerate the development and deployment of photovoltaic solar energy as a significant and sustainable renewable energy option. The objective of Task 10 is stated as being to enhance the opportunities for wide-scale, solution-oriented application of photovoltaics in the urban environment. The paper discusses the goal of mainstreaming PV systems in the urban environment. In this report, PV grid interconnection issues and countermeasures based on the latest studies are identified and summarised. Appropriate and understandable information is provided for all possible stakeholders. Possible impacts and benefits of PV grid interconnection are identified, technical measures designed to eliminate negative impacts and enhance possible benefits are presented. The status of research and demonstration projects is introduced and the latest outcomes are summarised. Recommendations and conclusions based on the review process are summarised and presented.

  8. Control of Grid Interactive PV Inverters for High Penetration in Low Voltage Distribution Networks

    DEFF Research Database (Denmark)

    Demirok, Erhan

    . On the other hand, unnecessarily strict grid connection requirements may cause less utilization of solar potential and may lead to additional cost on PV plants. PV based generating plants are basically interfaced to electricity grid via power inverters. Hardware and control design requirements...... for this problem but PV inverters connected to highly capacitive networks are able to employ extra current and voltage harmonics compensation to avoid triggering network resonances at low order frequencies. The barriers such as harmonics interaction, flicker, fault current contribution and dc current injections...... networks, PV inverter current limitation, transformer and cable/line thermal limits with increased reactive power flow. Therefore, the highest voltage drop should be realized with minimum reactive power absorption from the grid. Weak points of voltage support strategies which were already imposed by grid...

  9. Electrical PV array reconfiguration strategy for energy extraction improvement in grid-connected PV systems

    OpenAIRE

    2009-01-01

    This paper applies a dynamical electrical array reconfiguration (EAR) strategy on the photovoltaic (PV) generator of a grid-connected PV system based on a plant-oriented configuration, in order to improve its energy production when the operating conditions of the solar panels are different. The EAR strategy is carried out by inserting a controllable switching matrix between the PV generator and the central inverter, which allows the electrical reconnection of the available PV modules. A...

  10. Powering a Home with Just 25 Watts of Solar PV. Super-Efficient Appliances Can Enable Expanded Off-Grid Energy Service Using Small Solar Power Systems

    Energy Technology Data Exchange (ETDEWEB)

    Phadke, Amol A. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Jacobson, Arne [Schatz Energy Research Center, Arcata, CA (United States); Park, Won Young [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Lee, Ga Rick [Schatz Energy Research Center, Arcata, CA (United States); Alstone, Peter [Univ. of California, Berkeley, CA (United States); Khare, Amit [Schatz Energy Research Center, Arcata, CA (United States)

    2015-04-01

    Highly efficient direct current (DC) appliances have the potential to dramatically increase the affordability of off-grid solar power systems used for rural electrification in developing countries by reducing the size of the systems required. For example, the combined power requirement of a highly efficient color TV, four DC light emitting diode (LED) lamps, a mobile phone charger, and a radio is approximately 18 watts and can be supported by a small solar power system (at 27 watts peak, Wp). Price declines and efficiency advances in LED technology are already enabling rapidly increased use of small off-grid lighting systems in Africa and Asia. Similar progress is also possible for larger household-scale solar home systems that power appliances such as lights, TVs, fans, radios, and mobile phones. When super-efficient appliances are used, the total cost of solar home systems and their associated appliances can be reduced by as much as 50%. The results vary according to the appliances used with the system. These findings have critical relevance for efforts to provide modern energy services to the 1.2 billion people worldwide without access to the electrical grid and one billion more with unreliable access. However, policy and market support are needed to realize rapid adoption of super-efficient appliances.

  11. Solar Power Sources: PV, Concentrated PV, and Concentrated Solar Power

    DEFF Research Database (Denmark)

    Kim, Katherine A.; Mentesidi, Konstantina; Yang, Yongheng

    2017-01-01

    Solar power is highly abundant, relatively reliable, and not limited to a geographic region, making it one of the most important renewable energy sources. Catering for a clean and green energy system, solar energy will be an active player in the future mixed power grid that is also undergoing a s...

  12. Development of an Advanced Grid-Connected PV-ECS System Considering Solar Energy Estimation

    Science.gov (United States)

    Rahman, Md. Habibur; Yamashiro, Susumu; Nakamura, Koichi

    In this paper, the development and the performance of a viable distributed grid-connected power generation system of Photovoltaic-Energy Capacitor System (PV-ECS) considering solar energy estimation have been described. Instead of conventional battery Electric Double Layer Capacitors (EDLC) are used as storage device and Photovoltaic (PV) panel to generate power from solar energy. The system can generate power by PV, store energy when the demand of load is low and finally supply the stored energy to load during the period of peak demand. To realize the load leveling function properly the system will also buy power from grid line when load demand is high. Since, the power taken from grid line depends on the PV output power, a procedure has been suggested to estimate the PV output power by calculating solar radiation. In order to set the optimum value of the buy power, a simulation program has also been developed. Performance of the system has been studied for different load patterns in different weather conditions by using the estimated PV output power with the help of the simulation program.

  13. Islanding Issues of Grid-connected PV Systems

    Directory of Open Access Journals (Sweden)

    S.Narendiran

    2013-04-01

    Full Text Available ‘Islanding’ is a term, which refers to the situation when the Distributed generator (DG continues to power the consumer-end even when the electrical power from the electric utility is no longerpresent. Islanding phenomenon occurs after the certain part of the utility grid gets disconnected from a large number of inter-connected PVs. It leads to troubles in voltage and frequency control and powerquality issues. Therefore there is a need for appropriate anti-islanding measures for grid-connected PV systems. There are two ways to defeat the islanding phenomenon, by reactor insertion method on utility side and capacitor insertion method on PV side. Some of the Islanding detection methods (IDMs are broadly classifies as Active, Passive and Utility based. Active mode of detection includes impedance measurement, slip mode frequency shift and frequency bias. Passive methods contain over/under voltage and frequency and harmonics detection. Utility-based methods consist of manual disconnection, SCADA, impedance insertion.

  14. Effect of Reactive Power Management of PV Inverters on Need for Energy Storage

    DEFF Research Database (Denmark)

    Hashemi Toghroljerdi, Seyedmostafa; Østergaard, Jacob; Yang, Guangya

    2013-01-01

    Grid connected Photovoltaic (PV) systems are among the increasingly growing electric power generation units worldwide. The majority of new installations are expected to be residential PVs that are connected into distribution systems. However, the PV hosting capacity of low voltage (LV) grids...... is limited due to the voltage rise at the point of connection associated with the PV feed-in current. Reactive power management using PV inverters and using the electrical energy storage systems (EESS) are amongst the main solutions for increasing the PV hosting capacity in LV grids. In this paper, a method...

  15. PV GRID Advisory Paper. Consultation version: key recommendations

    Energy Technology Data Exchange (ETDEWEB)

    Barth, Bianca; Concas, Giorgia; Cossent, Rafael; Franz, Oliver; Frias, Pablo; Hermes, Roland; Lama, Riccardo; Loew, Holger; Mateo, Carlos; Rekinger, Manoel; Sonvilla, Paolo Michele; Vandenbergh, Michel

    2014-01-15

    PV GRID is a transnational collaborative effort under the umbrella of the Intelligent Energy Europe programme. The main project goal is to enhance photovoltaic (PV) hosting capacity in distribution grids while overcoming regulatory and normative barriers hampering the application of available technical solutions. The European PV GRID advisory paper aims at providing an overview of the issues and barriers that need to be addressed in order to enhance the distribution grid hosting capacity for PV and other distributed generation (DG).To this purpose, barriers are classified as either cross-cutting challenges or specific barriers, depending on whether they have an overarching, system-wide character or rather focus on one single issue such as curtailment, self-consumption or storage. Finally, a set of preliminary recommendations on how to overcome these issues is presented, allowing for the implementation of the identified technical solutions.

  16. Modified Multilevel Inverter Topology for Grid Connected Pv Systems

    Directory of Open Access Journals (Sweden)

    Dhivya Balakrishnan

    2013-10-01

    Full Text Available Multilevel converters offer high power capability, associated with lower output harmonics and lower commutation losses. Their main disadvantage is their complexity, requiring a great number of power devices and passive components, and a rather complex control circuitry. This paper proposes a single-phase seven- level inverter for grid connected PV systems, with a novel pulse width-modulated (PWM control scheme. Three reference signals that are identical to each other with an offset that is equivalent to the amplitude of the triangular carrier signal were used to generate the PWM signals. The inverter is capable of producing seven levels of output-voltage levels from the dc supply voltage. This paper proposes a new multilevel inverter topology using an H-bridge output stage with two bidirectional auxiliary switches. The new topology produces a significant reduction in the number of power devices and capacitors required to implement a multilevel output using the Asymmetric Cascade configuration.

  17. Comparative Study of on and off Grid Tied Integrated Diesel/Solar (PV) Battery Generation System

    OpenAIRE

    Okedu, Kenneth; Uhunmwangho, Roland; Bassey, Ngang

    2015-01-01

    This paper presents a proposed hybrid system based on diesel generator and solar photovoltaic (PV) as an effective option to power a small remote community. The cost of running diesel generator speedily due to erratic power supply in a small remote community that is not grid connected is highly expensive and not environmentally friendly. A solar PV was used to reduce or augment the continuous diesel generator sets, resulting in reduced cost of operation and maintenance. A proper solar radiati...

  18. CPV Vs. PV from a grid-matching perspective

    Science.gov (United States)

    Strobach, E.; Bader, S.; Faiman, D.; Solomon, A. A.; Meron, G.

    2012-10-01

    In a recently-published series of papers we studied the general problem of matching large PV systems of various kinds to the electricity grid. In those studies CPV systems were simulated via an artificial ansatz in which they were treated as 2-axis flat-panel PV systems whose light sensitivity is only to the direct normal component (DNI) of solar irradiance. The present study replaces this ansatz with an experimentally validated model of a real CPV system. We compare a genuine 2-axis high-concentration CPV system with a static flat-panel PV system from the standpoint of matching both system types to the Israeli electricity grid.

  19. Optimum Design Of On Grid Pv System Using Tracking System

    Directory of Open Access Journals (Sweden)

    Saeed Mansour

    2015-05-01

    Full Text Available Abstract The fossil fuel is a main issue in the world due to the increase of fossil fuel cost and the depletion of the fossil fuel with continuous increasing demand on electricity. With continuous decrease of PV panels cost it is interesting to consider generation of electricity from PV system. To provide electric energy to a load in a remote area where electric grid utility is not available or connection with grid utility is available there are two approaches of photovoltaic system PV without tracking system Fixed System and PV with tracking systems. The result shows that the energy production by using PV with tracking system generates more energy in comparison with fixed panels system. However the cost per produced KWH is less in case of using fixed panels. This is the backbone in choice between two approaches of photovoltaic system. In this work a system design and cost analysis for two approaches of photovoltaic system are considered.

  20. 光伏并网对配电网电压及网损的影响%Grid-connected PV impacts on voltage and power loss in distribution network

    Institute of Scientific and Technical Information of China (English)

    桑静静; 赵庆生; 何志方

    2013-01-01

    光伏电源的出力受环境温度、光照强度等因素的影响,其输出功率具有不确定性,会导致光伏电源接入点的电压波动,甚至越限.采用定点迭代的配电网潮流算法,对三相不平衡的光伏并网发电系统进行了潮流计算.根据潮流计算结果,结合IEEE13节点馈线系统,研究了光伏电源接入容量的变化对配电网电压分布及网损的影响.研究结果表明,光伏电源渗透率增大到一定程度后就会产生反向的潮流,并且系统节点电压及功率损耗也会有大的变化.%The output of photovoltaic cells is affected by environment temperature, solar irradiance and other factors, and its uncertainty leads to voltage fluctuations and even out of range at the access points of the PV systems. Fixed-point iteration method is introduced and the power flow of three-phase unbalanced grid-connected PV system is calculated. Then according to the power flow calculation results and combined with the IEEE 13 node feeder system, the changes in the grid voltage and power losses are researched with the different capacities of PV. Finally it can be shown that the trend of power flow will reverse when the PV power penetration increases to a certain extent, and the system node voltage and power loss have changed a lot.

  1. Reliability Oriented Design Tool For the New Generation of Grid Connected PV-Inverters

    DEFF Research Database (Denmark)

    Sintamarean, Nicolae Cristian; Blaabjerg, Frede; Wang, Huai

    2015-01-01

    This paper introduces a reliability-oriented design tool for a new generation of grid-connected photovoltaic (PV) inverters. The proposed design tool consists of a real field mission profile (RFMP) model (for two operating regions: USA and Denmark), a PV panel model, a grid-connected PV inverter...... model, an electrothermal model, and the lifetime model of the power semiconductor devices. An accurate long-term simulation model able to consider the one-year RFMP (solar irradiance and ambient temperature) is developed. Thus, the one-year estimation of the converter device thermal loading distribution...... is achieved and is further used as an input to the lifetime model. The proposed reliability-oriented design tool is used to study the impact of mission profile (MP) variation and device degradation (aging) in the PV inverter lifetime. The obtained results indicate that the MP of the field where the PV...

  2. Codes, standards, and PV power systems. A 1996 status report

    Energy Technology Data Exchange (ETDEWEB)

    Wiles, J

    1996-06-01

    As photovoltaic (PV) electrical power systems gain increasing acceptance for both off-grid and utility-interactive applications, the safety, durability, and performance of these systems gains in importance. Local and state jurisdictions in many areas of the country require that all electrical power systems be installed in compliance with the requirements of the National Electrical Code{reg_sign} (NEC{reg_sign}). Utilities and governmental agencies are now requiring that PV installations and components also meet a number of Institute of Electrical and Electronic Engineers (IEEE) standards. PV installers are working more closely with licensed electricians and electrical contractors who are familiar with existing local codes and installation practices. PV manufacturers, utilities, balance of systems manufacturers, and standards representatives have come together to address safety and code related issues for future PV installations. This paper addresses why compliance with the accepted codes and standards is needed and how it is being achieved.

  3. Advanced Analysis of Grid-connected PV System's Performance and Effect of Battery

    Science.gov (United States)

    Ueda, Yuzuru; Kurokawa, Kosuke; Itou, Takamitsu; Kitamura, Kiyoyuki; Akanuma, Katsumi; Yokota, Masaharu; Sugihara, Hiroyuki; Morimoto, Atsushi

    An advanced analysis method for grid connected PV systems is developed in this research. To investigate the issues which may happen in the clustered PV systems, “Demonstrative research on clustered PV systems" is being conducted from December, 2002, in Oota, Japan. More than 500 residential PV systems will be installed in the demonstrative research area, battery integrated PV systems are developed to avoid the restriction of output power due to the raising of grid voltage. Annual performance of commercial PV systems without battery is analyzed and resulted in around 80% of performance ratio on the average. Over voltage of power distribution line and snow are two major factors of very low performance ratio on daily basis. Effects of batteries are also analyzed, the results indicate that there will be some improvement for the energy loss due to the grid voltage but PCS's efficiency will be around 8% worse than that of the commercial PV systems. It is also found that the non-optimized operation of battery sometimes results in the fully-charged situation during the noontime and maximum reverse power flow may not be minimized in this situation.

  4. Static Equivalent of Distribution Grids With High Penetration of PV Systems

    DEFF Research Database (Denmark)

    Samadi, Afshin; Söder, Lennart; Shayesteh, Ebrahim;

    2015-01-01

    High penetrations of photovoltaic (PV) systems within load pockets in distribution grids have changed pure consumers to prosumers. This can cause technical challenges in distribution and transmission grids, such as overvoltage and reverse power flow. Embedding voltage support schemes into PVs......, such as standard cos phi(P) characteristic proposed by the German grid codes, may cause more changes in the steady-state behavior of distribution grids and, in turn, the transmission side. Accordingly, it is important to properly model active distribution grids to analyze the system impacts of these changes...... to plan and operate future smart power grids. However, due to the high dimension of distribution grids, considering a detailed distribution grid to study the transmission side or a fraction of the distribution grid is either cumbersome or impractical. Therefore, it is required to develop a reasonable...

  5. 滑模变结构矢量控制在三相光伏并网系统中的应用%SLIDING MODE VARIABLE STRUCTURE VECTOR CONTROL OF THREE-PHASE GRID-CONNECTED PV POWER SYSTEM

    Institute of Scientific and Technical Information of China (English)

    李军红; 洪镇南

    2013-01-01

    研究三相单级光伏并网系统,建立并网逆变器在同步旋转d-q坐标系下的数学模型,提出一种新型的滑模变结构矢量控制方法.将并网电流分解为有功电流和无功电流,控制无功电流分量为零,实现单位功率因数并网;控制有功电流分量为MPPT算法给定的参考值,实现最大输出功率跟踪.组建实验样机,进行稳态和动态性能测试,实验结果表明所提出系统的可行性和控制策略的有效性.%The three-phase on-grid PV power generation system is studied,and mathematical model of three-phase on-grid inverter was established in synchronous rotating reference frame (d-q).A novel sliding mode variable structure vector control methods is put forward,which made the grid current into the active current and the reactive current.Unit power factor is achieved by controlling the reactive current component to be zero; and PV maximum power output was realized by controlling the active current component to be the reference value given by MPPT controller.A laboratory prototype is designed to perform static and dynamic experiments.Some experimental results verify that the proposed control strategy can improve the quality of grid current and supply power to grid with unity power factor.

  6. An investigation of the maximum penetration level of a photovoltaic (PV) system into a traditional distribution grid

    Science.gov (United States)

    Chalise, Santosh

    Although solar photovoltaic (PV) systems have remained the fastest growing renewable power generating technology, variability as well as uncertainty in the output of PV plants is a significant issue. This rapid increase in PV grid-connected generation presents not only progress in clean energy but also challenges in integration with traditional electric power grids which were designed for transmission and distribution of power from central stations. Unlike conventional electric generators, PV panels do not have rotating parts and thus have no inertia. This potentially causes a problem when the solar irradiance incident upon a PV plant changes suddenly, for example, when scattered clouds pass quickly overhead. The output power of the PV plant may fluctuate nearly as rapidly as the incident irradiance. These rapid power output fluctuations may then cause voltage fluctuations, frequency fluctuations, and power quality issues. These power quality issues are more severe with increasing PV plant power output. This limits the maximum power output allowed from interconnected PV plants. Voltage regulation of a distribution system, a focus of this research, is a prime limiting factor in PV penetration levels. The IEEE 13-node test feeder, modeled and tested in the MATLAB/Simulink environment, was used as an example distribution feeder to analyze the maximum acceptable penetration of a PV plant. The effect of the PV plant's location was investigated, along with the addition of a VAR compensating device (a D-STATCOM in this case). The results were used to develop simple guidelines for determining an initial estimate of the maximum PV penetration level on a distribution feeder. For example, when no compensating devices are added to the system, a higher level of PV penetration is generally achieved by installing the PV plant close to the substation. The opposite is true when a VAR compensator is installed with the PV plant. In these cases, PV penetration levels over 50% may be

  7. Experimental Evaluation of Grid Support Enabled PV Inverter Response to Abnormal Grid Conditions: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Austin; Martin, Gregory; Hurtt, James

    2017-05-08

    As revised interconnection standards for grid-tied photovoltaic (PV) inverters address new advanced grid support functions (GSFs), there is increasing interest in inverter performance in the case of abnormal grid conditions. The growth of GSF-enabled inverters has outpaced the industry standards that define their operation, although recently published updates to UL1741 with Supplement SA define test conditions for GSFs such as volt-var control, frequency-watt control, and volt-age/frequency ride-through, among others. A comparative experimental evaluation has been completed on four commercially available, three-phase PV inverters in the 24.0-39.8 kVA power range on their GSF capability and the effect on abnormal grid condition response. This study examines the impact particular GSF implementations have on run-on times during islanding conditions, peak voltages in load rejection overvoltage scenarios, and peak currents during single-phase and three-phase fault events for individual inverters. This report reviews comparative test data, which shows that GSFs have little impact on the metrics of interest in most tests cases.

  8. 一种基于 HHT 的光伏并网发电系统保护方法%A protection method of grid-connected PV power system based on HHT

    Institute of Scientific and Technical Information of China (English)

    程宏波; 陈臣; 王勋; 伦利; 闫俊丽

    2016-01-01

    When the short circuit faults of grid-connected PV ( photovoltaic ) power system supply occurred , the fault current of PV power happens transient , due to the protective effect of inverter control circuit , the amplitude of fault current is small , as a result that the traditional detection methods cann ’ t satisfy the requirements of grid connected PV generation .In order to seek protection method for grid-connected PV power system , the simulation model was set up based on PSCAD/EMTDC, the characteristics of the short-circuit current are analyzed , and Hilbert-Huang transform ( HHT) was proposed to decompose the fault waveform of current , which found the instantaneous frequency of the fault current is changing when single-phase to ground fault occurs , with this the protection scheme of grid connected PV system based on HHT is proposed .The effectiveness and feasibility of this protection scheme are verified .%当光伏发电系统所连电网发生短路故障时,光伏电源的故障电流会发生暂态突变,但由于逆变器控制电路的保护作用,短路电流的幅值较小,因而传统的保护方法对光伏并网发电系统不一定适用。为寻求适合光伏并网发电系统的保护方法,建立了基于PSCAD/EMTDC的光伏并网发电系统仿真模型,对其短路电流的特性进行了仿真分析,利用希尔伯特-黄变换( HHT)对故障电流的波形进行分解,提出一种基于HHT的光伏并网发电系统保护方法,并进行了算例分析。结果表明,在含有光伏发电的电网发生短路故障时,该保护方法具有一定的有效性和可行性。

  9. 并网光伏电站的PSASP/UPI仿真建模及分析%PSASP/UPI Simulation Modelling and Analysis of the PV Power Station in Grid Integration

    Institute of Scientific and Technical Information of China (English)

    孙文涛; 刘涤尘; 赵洁; 董飞飞; 陈恩泽; 曾正

    2014-01-01

    针对光伏电站和电网之间的交互影响,研究了适用于电网暂态分析的光伏电站模型,建立了含光伏阵列、逆变器、滤波器及控制保护系统的并网光伏电站暂态模型,并应用 Matlab实时工具包模块和 VC++语言生成了可被PSASP调用的自定义模型,仿真研究了并网光伏电站出力变化对电网影响及电网故障对以不同方式接入电网的并网光伏电站的影响。结果表明,该模型可用于光伏电站与电网的联合仿真。大规模光伏电源集中接入会引起电网电压波动;电网故障可能触发光伏电站脱网,使故障扩大;且在负荷母线集中接入方式下对电网电压及暂态稳定的影响更大。%To study the interaction between the PV power plant and power grid, grid-connected photovoltaic system( GCPS) transient model is built. The transient model includes photovoltaic array, inverter, filter, as well as control and protection system. The custom model that can be called by PSASP is generated by RTW ( Real-Time Workshop, RTW) modules in Matlab and VC+ +. In addi-tion, the variation of GCPS's power output and its impact on power grid are researched, and the influence of power grid fault on GCPS with different connection modes is also analyzed. The simulation results show that the model can be used for joint simulation between the GCPS and the power grid. Large-scale photovoltaic power connected to power grid will cause the grid voltage fluctuation, The power grid fault may lead to disconnection between the GCPS and the grid, resulting in the fault to expand. It takes the greater adverse impact to the voltage and transient stability of power grid when the GCPS is connected to the load bus.

  10. Low-voltage grid-connection of photovoltaic power systems

    Energy Technology Data Exchange (ETDEWEB)

    Collinson, A.; Thornycroft, J.

    1999-07-01

    This report summarises the results of a project aimed at developing technical guidelines concerning grid connected photovoltaic (PV) inverter generators which are to be published in draft form as the {sup U}K Technical Guidelines for Inverter Connected Single Phase Photovoltaic (PV) Generators up to 5kVA{sup .} The background to the use of PV in the UK is traced, and the technical criteria for electrical integration of PV systems, and UK guidelines for grid connected PV systems are examined. The findings of the working group of the International Energy Agency (IEA) Implementing Agreement on Photovoltaic Power Systems are also presented in this report. Appendices discuss the UK technical guidelines, the IEA Task V activities,, utility aspects of grid-connected PV systems, and demonstration tests on grid-connected PV systems, and lists Task V reports.

  11. Modeling Single-Phase PV HB-ZVR Inverter Connected to Grid

    DEFF Research Database (Denmark)

    Guo, Yougui; Zeng, Ping; Zhu, Jieqiong;

    2011-01-01

    PLECS is used to model the PV H-bridge zero voltage rectifier (HB-ZVR) inverter connected to grid and good results are obtained. First, several common topologies of PV inverters are introduced. Then the unipolar PWM control strategy is described for PV HB-ZVR inverter. Third, PLECS is briefly...... introduced. Fourth, the modeling of PV HB-ZVR inverter is presented with PLECS. Finally, a series of simulations are carried out. The simulation results tell us PLECS is very powerful tool to real power circuits and it is very easy to simulate LCL filter. They have also verified that the unipolar PWM control...... strategy is feasible to control the PV HB-ZVR inverter....

  12. Efficient Control of Energy Storage for Increasing the PV Hosting Capacity of LV Grids

    DEFF Research Database (Denmark)

    Hashemi Toghroljerdi, Seyedmostafa; Østergaard, Jacob

    2016-01-01

    hosting capacity of LV grids by determining dynamic set points for EESS management. The method has the effectiveness of central control methods and can effectively decrease the energy storage required for overvoltage prevention, yet it eliminates the need for a broadband and fast communication. The net...... power injected into the grid and the amount of reactive power absorbed by PV inverters are estimated using the PV generation forecast and load consumption forecast, and the dynamic operating points for energy storage management are determined for a specific period of time by solving a linear...... grid is usually limited by overvoltage, and the efficient control of distributed electrical energy storage systems (EESSs) can considerably increase this capacity. In this paper, a new control approach based on the voltage sensitivity analysis is proposed to prevent overvoltage and increase the PV...

  13. Battery Energy Storage System for PV Output Power Leveling

    Directory of Open Access Journals (Sweden)

    Rajkiran Singh

    2014-01-01

    Full Text Available Fluctuating photovoltaic (PV output power reduces the reliability in power system when there is a massive penetration of PV generators. Energy storage systems that are connected to the PV generators using bidirectional isolated dc-dc converter can be utilized for compensating the fluctuating PV power. This paper presents a grid connected energy storage system based on a 2 kW full-bridge bidirectional isolated dc-dc converter and a PWM converter for PV output power leveling. This paper proposes two controllers: a current controller using the d-q synchronous reference and a phase-shift controller. The main function of the current controller is to regulate the voltage at the high-side dc, so that the voltage ratio of the high-voltage side (HVS with low-voltage side (LVS is equal to the transformer turns ratio. The phase-shift controller is employed to manage the charging and discharging modes of the battery based on PV output power and battery voltage. With the proposed system, unity power factor and efficient active power injection are achieved. The feasibility of the proposed control system is investigated using PSCAD simulation.

  14. A Simulation of Energy Storage System for Improving the Power System Stability with Grid-Connected PV using MCA Analysis and LabVIEW Tool

    Directory of Open Access Journals (Sweden)

    Jindrich Stuchly

    2015-01-01

    Full Text Available The large-scale penetration of distributed, Renewable power plants require transfers of large amounts of energy. This, in turn, puts a high strain on the energy delivery infrastructure. In particular, photovoltaic power plants supply energy with high intermittency, possibly affecting the stability of the grid by changing the voltage at the plant connection point. In this contribution, we summarize the main negative effects of selected and real-operated grid connected photovoltaic plant. Thereafter a review of suitable Energy storage systems to mitigate the negative effects has been carried out, compared and evaluated using Multi-criterion analysis. Based on this analysis, data collected at the plant and the grid, are used to design the energy storage systems to support connection of the plant to the grid. The cooperation of these systems is then analysed and evaluated using simulation tools created in LabVIEW for this purpose. The simulation results demonstrate the capability of energy storage system solutions to significantly reduce the negative feedback effects of Photovoltaic Power Plan to the low voltage grid.

  15. Grid-connected photovoltaic (PV) systems with batteries storage as solution to electrical grid outages in Burkina Faso

    Science.gov (United States)

    Abdoulaye, D.; Koalaga, Z.; Zougmore, F.

    2012-02-01

    This paper deals with a key solution for power outages problem experienced by many African countries and this through grid-connected photovoltaic (PV) systems with batteries storage. African grids are characterized by an insufficient power supply and frequent interruptions. Due to this fact, users who especially use classical grid-connected photovoltaic systems are unable to profit from their installation even if there is sun. In this study, we suggest the using of a grid-connected photovoltaic system with batteries storage as a solution to these problems. This photovoltaic system works by injecting the surplus of electricity production into grid and can also deliver electricity as a stand-alone system with all security needed. To achieve our study objectives, firstly we conducted a survey of a real situation of one African electrical grid, the case of Burkina Faso (SONABEL: National Electricity Company of Burkina). Secondly, as study case, we undertake a sizing, a modeling and a simulation of a grid-connected PV system with batteries storage for the LAME laboratory at the University of Ouagadougou. The simulation shows that the proposed grid-connected system allows users to profit from their photovoltaic installation at any time even if the public electrical grid has some failures either during the day or at night.

  16. Benchmark Networks for grid integration impact studies of large PV plants

    DEFF Research Database (Denmark)

    Craciun, Bogdan-Ionut; Kerekes, Tamas; Sera, Dezso

    2013-01-01

    The increased amount of Photovoltaic (PV) power installed into the power system every year places this renewable way of producing electricity on the third position in the renewable sources hierarchy after hydro and wind solutions. Having significant levels of renewable power penetration into the ......The increased amount of Photovoltaic (PV) power installed into the power system every year places this renewable way of producing electricity on the third position in the renewable sources hierarchy after hydro and wind solutions. Having significant levels of renewable power penetration...... the system stable and harmonize the operation of the renewable plants with the entire system. For this purpose valid grid benchmarks such as IEEE 12 bus system for High Voltage (HV) and Cigré benchmark cell model for Medium Voltage (MV) have to be developed, tested together and prove that in the future power...... system with large PV penetration levels on every level, the system continues to be reliable and redundant....

  17. Design of A Grid Integrated PV System with MPPT Control and Voltage Oriented Controller using MATLAB/PLECES

    Science.gov (United States)

    Soreng, Bineeta; Behera, Pradyumna; Pradhan, Raseswari

    2017-08-01

    This paper presents model of a grid-integrated photovoltaic array with Maximum Power Point Tracker (MPPT) and voltage oriented controller. The MPPT of the PV array is usually an essential part of PV system as MPPT helps the operating point of the solar array to align its maximum power point. In this model, the MPPT along with a DC-DC converter lets a PV generator to produce continuous power, despite of the measurement conditions. The neutral-point-clamped converter (NPC) with a boost converter raises the voltage from the panels to the DC-link. An LCL-filter smoothens the current ripple caused by the PWM modulation of the grid-side inverter. In addition to the MPPT, the system has two more two controllers, such as voltage controller and a current controller. The voltage control has a PI controller to regulate the PV voltage to optimal level by controlling the amount of current injected into the boost stage. Here, the grid-side converter transfers the power from the DC-link into the grid and maintains the DC-link voltage. Three-phase PV inverters are used for off-grid or designed to create utility frequency AC. The PV system can be connected in series or parallel to get the desired output power. To justify the working of this model, the grid-integrated PV system has been designed in MATLAB/PLECS. The simulation shows the P-V curve of implemented PV Array consisting 4 X 20 modules, reactive, real power, grid voltage and current.

  18. Quantitative Analysis Method of Output Loss due to Restriction for Grid-connected PV Systems

    Science.gov (United States)

    Ueda, Yuzuru; Oozeki, Takashi; Kurokawa, Kosuke; Itou, Takamitsu; Kitamura, Kiyoyuki; Miyamoto, Yusuke; Yokota, Masaharu; Sugihara, Hiroyuki

    Voltage of power distribution line will be increased due to reverse power flow from grid-connected PV systems. In the case of high density grid connection, amount of voltage increasing will be higher than the stand-alone grid connection system. To prevent the over voltage of power distribution line, PV system's output will be restricted if the voltage of power distribution line is close to the upper limit of the control range. Because of this interaction, amount of output loss will be larger in high density case. This research developed a quantitative analysis method for PV systems output and losses to clarify the behavior of grid connected PV systems. All the measured data are classified into the loss factors using 1 minute average of 1 second data instead of typical 1 hour average. Operation point on the I-V curve is estimated to quantify the loss due to the output restriction using module temperature, array output voltage, array output current and solar irradiance. As a result, loss due to output restriction is successfully quantified and behavior of output restriction is clarified.

  19. 不平衡电网电压下光伏并网逆变器滑模直接电压/功率控制策略%Sliding mode control based direct voltage/power control strategy for PV grid connected inverter under unbalanced grid voltage

    Institute of Scientific and Technical Information of China (English)

    朱晓荣; 刘世鹏; 张海宁; 王东方; 李春来

    2016-01-01

    不平衡电网电压下,光伏并网逆变器的输出功率和输出电流都将产生波动,给电力系统的稳定运行造成不利影响。根据光伏并网系统的数学模型,提出了光伏并网逆变器基于滑模控制的直接电压/功率控制策略。该控制策略可在电网电压不平衡时有效抑制并网逆变器输出有功功率和无功功率的波动。根据光伏并网逆变器输出功率和正、负序电流的关系,提出了以消除负序电流为控制目标的改进控制策略。此外,为提高系统的运行性能,提出了功率电流协调控制策略。最后,对所提出的控制策略进行了仿真分析,仿真结果验证了所提出控制策略的有效性。%Under unbalanced grid voltage, second order pulsation component will appear in the output power and the output current of the PV grid connected inverter, which will affect the stable operation of the power system. Based on the mathematical model of PV grid connected system, this paper proposes a direct voltage/power control strategy based on sliding mode control (SMC) for the PV grid connected inverter. When the grid voltage is unbalanced, the control strategy can effectively suppress the power oscillation in the active and reactive power. According to the relationship between the output power and the positive/negative sequence current of the PV grid connected inverter, an improved control strategy is proposed to eliminate the negative sequence current. In addition, a power/current coordinated control strategy is proposed to improve the operating performance of the PV system. Finally, simulation analysis is carried out, and the results verify the effectiveness of the proposed control strategy.

  20. High Penetration Solar PV Deployment Sunshine State Solar Grid Initiative (SUNGRIN)

    Energy Technology Data Exchange (ETDEWEB)

    Meeker, Rick [Nhu Energy, Inc., Tallahassee, FL (United States); Florida State Univ., Tallahassee, FL (United States); Steurer, Mischa [Florida State Univ., Tallahassee, FL (United States); Faruque, MD Omar [Florida State Univ., Tallahassee, FL (United States); Langston, James [Florida State Univ., Tallahassee, FL (United States); Schoder, Karl [Florida State Univ., Tallahassee, FL (United States); Ravindra, Harsha [Florida State Univ., Tallahassee, FL (United States); Hariri, Ali [Florida State Univ., Tallahassee, FL (United States); Moaveni, Houtan [New York Power Authority (NYPA), New York (United States); University of Central Florida, Florida Solar Energy Center, Cocoa, FL (Unitied States); Click, Dave [ESA Renewables, LLC, Sanford, FL (United States); University of Central Florida, Florida Solar Energy Center, Cocoa, FL (United States); Reedy, Bob [University of Central Florida, Florida Solar Energy Center, Cocoa, FL (United States)

    2015-05-31

    The report provides results from the Sunshine State Solar Grid Initiative (SUNGRIN) high penetration solar PV deployment project led by Florida State University’s (FSU) Center for Advanced Power Systems (CAPS). FSU CAPS and industry and university partners have completed a five-year effort aimed at enabling effective integration of high penetration levels of grid-connected solar PV generation. SUNGRIN has made significant contributions in the development of simulation-assisted techniques, tools, insight and understanding associated with solar PV effects on electric power system (EPS) operation and the evaluation of mitigation options for maintaining reliable operation. An important element of the project was the partnership and participation of six major Florida utilities and the Florida Reliability Coordinating Council (FRCC). Utilities provided details and data associated with actual distribution circuits having high-penetration PV to use as case studies. The project also conducted foundational work supporting future investigations of effects at the transmission / bulk power system level. In the final phase of the project, four open-use models with built-in case studies were developed and released, along with synthetic solar PV data sets, and tools and techniques for model reduction and in-depth parametric studies of solar PV impact on distribution circuits. Along with models and data, at least 70 supporting MATLAB functions have been developed and made available, with complete documentation.

  1. Simulation Analysis of Household Single-phase Grid-connected PV Power System%户用型单相光伏并网系统仿真分析

    Institute of Scientific and Technical Information of China (English)

    赵钢; 何军; 蒋辉

    2012-01-01

    针对3 kW光伏并网发电系统,详细分析了光伏电池的模型;采用扰动观察法实现最大功率点跟踪;选择电流内环电压外环的双环控制作为并网逆变器的控制策略,其中电流内环控制并网逆变器的输出电流跟随电网电压,电压外环控制直流母线电压稳定在400 V;将主动式频率偏移法运用于孤岛检测的算法控制,孤岛出现后2 s内迅速检测出孤岛并切断光伏逆变器。给出了基于MATLAB/Simulink的系统仿真模型。结果表明:光伏电池能很好地实现最大功率点跟踪,逆变后成功并网,在规定的时间内对孤岛做出判断,达到预期的设计目的。%In terms of a 3 kW grid-connected PV power system, this paper elaborates the model for PV cells. The ap- proach of perturbation and observation is utilized to track the maximum power point. A double loop control strategy is chosen for the grid inverter. Double loop control consists of an inner current loop and an outer voltage loop, where the inner current loop keeps the output of grid inverter following the network voltage and the outer voltage loop maintains the DC bus voltage at 400V. The application of active frequency shift method in the control algorithm of island detec- tion enables a quick detection of island (2s after its appearance) followed by the abscission of PV inverter. Then a system simulation model based on MATLAB/Simulink comes into being. The results show that PV cells can perfectly realize the track of maximum power point, as well as the successful interconnection after inverted, and can make right decision on island within regulated time. In brief, the expected design objective is fully attained.

  2. 离网型风光互补独立供电系统容量设计%Capacity design of off-grid wind/PV hybrid power system

    Institute of Scientific and Technical Information of China (English)

    彭有明; 詹跃东

    2015-01-01

    本文考虑供电系统的连续性,提出了风光互补供电系统设备容量设计,讨论了离网型光伏风能发电系统的构成及特点,以及蓄电池和控制器在系统中的重要作用。通过理论研究结合工程实际,对一种风光工程应用的光伏电池方阵、风机、控制器、蓄电池组和离网型逆变器的容量计算及选择进行了分析。本系统的应用,不但解决了发电系统存在的问题,还保障了风光互补供电系统的连续性、稳定性和可靠性,最终使其可以满足广大用电客户的需求。%In view of the continuity of the power supply system, the capacity design of wind/PV hybrid power system equipment was proposed. The construction and characteristics of off-grid wind and solar power generation system were discussed in this paper. The roles of controller and battery in the system were considered. By theoretical research and engineering practice, the capacity calculation and selection of a wind/PV hybrid power system with photovoltaic cell matrix, wind generator, controllers, batteries, and off-grid inverter were analyzed. The implementation of this system not only can solve the common problems of power system, but also can guarantee the continuity, stability and reliability of the wind and solar hybrid power system, thus meeting the requirements of general electricity customers ultimately.

  3. Grid Connected Solar PV System with SEPIC Converter Compared with Parallel Boost Converter Based MPPT

    Directory of Open Access Journals (Sweden)

    T. Ajith Bosco Raj

    2014-01-01

    Full Text Available The main objective of this work is to study the behaviour of the solar PV systems and model the efficient Grid-connected solar power system. The DC-DC MPPT circuit using chaotic pulse width modulation has been designed to track maximum power from solar PV module. The conversion efficiency of the proposed MPPT system is increased when CPWM is used as a control scheme. This paper also proposes a simplified multilevel (seven level inverter for a grid-connected photovoltaic system. The primary goal of these systems is to increase the energy injected to the grid by keeping track of the maximum power point of the panel, by reducing the switching frequency, and by providing high reliability. The maximum power has been tracked experimentally. It is compared with parallel boost converter. Also this model is based on mathematical equations and is described through an equivalent circuit including a PV source with MPPT, a diode, a series resistor, a shunt resistor, and dual boost converter with active snubber circuit. This model can extract PV power and boost by using dual boost converter with active snubber. By using this method the overall system efficiency is improved thereby reducing the switching losses and cost.

  4. PV grid-connected inverter based on voltage oriented-direct power control%基于电压定向直接功率控制的光伏并网逆变器

    Institute of Scientific and Technical Information of China (English)

    柴文野; 祝龙记

    2012-01-01

    The direct power control based on voltage oriented (V-DPC) was applied to a PV grid-connected inverter control strategy and the concept of estimation of the grid voltage and instantaneous power was introduced, taking the instantaneous active power and reactive power with the grid-connected inverter output as the controlled variables for power direct closed-loop control. The system need not to detect the transformer secondary voltage, the grid voltage sensor was omitted, and consequently the shortage of current control scheme was not only overcome, but also the cost was reduced. The system had the advantages of good robustness and simple control structure. The principle of voltage oriented-direct power control was analyzed, the specific parameters of the inverter were designed, and the simulation and experiment results were given.%将基于电压定向直接功率控制用于光伏并网逆变器的控制策略,引入电网电压和瞬时功率的估算概念,并将并网逆变器输出的瞬时有功功率和无功功率作为被控量进行功辜的直接闭环控制.系统无需检测输入变压器二次侧的电网电压,省去了电网电压传感器,从而不仅克服了电流控制方案的不足问题,还降低了成本,而且系统具有鲁棒性好、控制结构简单等优点.分析了电压定向直接功率控制的原理,设计了并网逆变器的具体参数,并给出了仿真和实验结果.

  5. Optimization of PV system operation in distributed electricity grids by intelligent energy management; Optimierung des Einsatzes von PV Anlagen in dezentral organisierten Stromnetzen durch intelligentes Betriebsmanagement

    Energy Technology Data Exchange (ETDEWEB)

    Erge, T.; Laukamp, H.; Puls, H.G.; Thoma, M.; Wittwer, C. [Fraunhofer-Inst. fuer Solare Energiesysteme ISE, Freiburg (Germany); Kroeger-Vodde, A. [PSE Projektgesellschaft Solare Energiesysteme mbH (Germany)

    2005-07-01

    With an increasing number of decentralized electricity generators especially in electrical distribution grid segments, energy flows in the grids are changing from an purely centralised supply structure towards more complex distributed solutions. With lots of fluctuating electricity generation from PV or other technologies, special emphasis must be put on high supply reliability, good power quality and economic operation of the grids. This can be achieved by applying intelligent energy management. (orig.)

  6. Grid Integration of Single Stage Solar PV System using Three-level Voltage Source Converter

    Science.gov (United States)

    Hussain, Ikhlaq; Kandpal, Maulik; Singh, Bhim

    2016-08-01

    This paper presents a single stage solar PV (photovoltaic) grid integrated power generating system using a three level voltage source converter (VSC) operating at low switching frequency of 900 Hz with robust synchronizing phase locked loop (RS-PLL) based control algorithm. To track the maximum power from solar PV array, an incremental conductance algorithm is used and this maximum power is fed to the grid via three-level VSC. The use of single stage system with three level VSC offers the advantage of low switching losses and the operation at high voltages and high power which results in enhancement of power quality in the proposed system. Simulated results validate the design and control algorithm under steady state and dynamic conditions.

  7. Dynamic Modeling, Control and Simulation of a Wind and PV Hybrid System for Grid Connected Application Using MATLAB

    OpenAIRE

    2014-01-01

    This paper proposes a dynamic modeling and control strategy for a grid connected hybrid wind and photovoltaic (PV) energy system inter-connected to electrical grid through power electronic interface. A gearless permanent magnet synchronous generator (PMSG) is used to capture the maximum wind energy. The PV and wind systems are connected dc-side of the voltage source inverter through a boost converter individually and maintain a fixed dc output at dc link. A proper control sche...

  8. Design of Energy Storage Control Strategy to Improve the PV System Power Quality

    DEFF Research Database (Denmark)

    Lei, Mingyu; Yang, Zilong; Wang, Yibo

    2016-01-01

    Random fluctuation of PV power is becoming a more and more serious problem affecting the power quality and stability of grid as the PV penetration keeps increasing recent years. Aiming at this problem, this paper proposed a control strategy of energy storage system based on Model Predictive Control...

  9. 基于MATLAB-PSASP的光伏并网暂态稳定计算模型%MATLAB-PSASP based transient stability computation model for grid-connection of PV power system

    Institute of Scientific and Technical Information of China (English)

    张巍; 向铁元; 李安; 谢小燕; 曾爽

    2012-01-01

    A model of PV(PhotoVoltaic) power system is established with MATLAB/Simulink,which adopts the control algorithm of MPPT(Maximum Power Point Tracking) and the logic control module of relay protection,and is connected to power system via the user program interface of PSASP and in the form of current source for transient stability computation. It is proposed that the reactive power exchange between PV and system in the current source mode of grid connection is controlled to zero. Therefore,the PV station is taken as PQ node with zero reactive power in power flow calculation. Simulative results of CEPRI 36-bus system show the correctness of the proposed model and demonstrate that,compared with the classical second-order model of synchronous motor,it responses to power grid fault more sensitively,but contributes little to the transient stability improvement of the whole power system.%在MATLAB/Simulink环境中搭建了光伏发电系统模型,其采用最大功率点跟踪(MPPT)控制算法,并加入继电保护逻辑控制模块.通过PSASP的用户程序接口,可将该模型以电流源的形式接入电网模型进行暂态稳定计算.同时提出在电流源并网模式下并网光伏发电系统控制其与电网的无功功率交换为0,因此在潮流计算中可将光伏电站设为PQ节点,并设无功功率为0.CEPRI 36节点系统的仿真结果验证了该模型的正确性,并表明所提模型比常规同步电机二阶经典模型对电网故障的反应更为灵敏,但其对于改善全系统的暂态稳定性作用不大.

  10. 单相光伏并网发电系统功率解耦的优化设计%Optimal Design of Power Decoupling in Single-phase Grid-connected PV Systems

    Institute of Scientific and Technical Information of China (English)

    徐政; 林崇; 何少强

    2012-01-01

    As a nonlinear DC power source, a solar array should operate at the maximum power point with a stable DC power output. Otherwise, the power output of a single-phase grid connected system contains an AC component with double grid frequency. Corresponding to such difference of input and output characteristics in single-phase grid connected PV systems, the influences of power pulsation on maximum power point tracking (MPPT), transfer efficiency and power quality of inverter were synthetically studied. The comparison of different circuit topologies was made by theoretical analysis, computer simulation as well as experiment, and an optimal design rule of decoupling capacitors was proposed which can improve the system operating efficiency as well as standardize product design.%作为非线性直流电源,光伏阵列的理想运行状态是在最大功率点上输出稳定的直流功率,而单相并网发电系统的并网功率含有2倍于电网频率的交流量.针对单相光伏并网发电系统这种输入与输出特性的差异,综合研究了并网功率脉动对最大功率点跟踪特性、逆变器转换效率及并网电能质量的影响,通过理论分析、仿真计算和实验验证,比较不同电路拓扑的特性,提出了解耦电容的优化设计准则,提高了系统的运行效率,实现了产品设计的规范化.

  11. Utility-scale grid-tied PV inverter reliability workshop summary report.

    Energy Technology Data Exchange (ETDEWEB)

    Granata, Jennifer E.; Quintana, Michael A.; Tasca, Coryne Adelle (SRA International, Inc., Fairfax, VA); Atcitty, Stanley

    2011-07-01

    A key to the long-term success of the photovoltaic (PV) industry is confidence in the reliability of PV systems. Inverters are the most commonly noted cause of PV system incidents triggered in the field. While not all of these incidents are reliability-related or even necessarily failures, they still result in a loss of generated power. With support from the U.S. Department of Energy's Solar Energy Technologies Program, Sandia National Laboratories organized a Utility-Scale Grid-Tied Inverter Reliability Workshop in Albuquerque, New Mexico, January 27-28, 2011. The workshop addressed the reliability of large (100-kilowatt+) grid-tied inverters and the implications when such inverters fail, evaluated inverter codes and standards, and provided discussion about opportunities to enhance inverter reliability. This report summarizes discussions and presentations from the workshop and identifies opportunities for future efforts.

  12. Using electric vehicle charging strategies to maximize PV-integration in the low voltage grid

    Energy Technology Data Exchange (ETDEWEB)

    Niesse, Astrid; Troeschel, Martin; Scherfke, Stefan; Schuette, Steffen [OFFIS, Oldenburg (Germany). R and D Div. Energy; Sonnenschein, Michael [Oldenburg Univ. (Germany). Dept. of Computing Science

    2011-07-01

    The role of electric vehicles (EV) in the low voltage grid has been discussed lately in many projects. An efficient energy management system for control of the charging processes while considering grid aspects is expected to raise high potential to build up Smart Grid functions. One focal point is to learn about the potential synergetic effects from EV and renewable energies regarding two main questions: (1) Is it possible to load EV batteries largely based on renewable sources - in particular PV - to guarantee positive carbon minimizing effects? (2) Can managed EV charging lead to an increased integration of fluctuating renewable energy resources in the grid? These questions can only be dealt with by keeping the status of the power infrastructure in perspective at any time -reliability of supply has to be ensured with high penetration of both EV and renewable energy resources. We used a simulative approach to follow up on these, studying the effects of charging processes for different shares of electric vehicles in the rural area of north-west Germany using characteristic grid types. Starting from these, we built up target scenarios that met our goals: Maximize PV integration, stabilize the grid and still guarantee the EV users' mobility. In this paper we present the results of scenarios with maximized PV integration and show the importance of managed charging processes to make best use of renewable feed-in for mobility purposes.

  13. Quasi-PR Power Quality Control of NPC Three-level Grid-connected PV System%NPC三电平光伏并网准PR电能质量控制

    Institute of Scientific and Technical Information of China (English)

    陈晖; 王睿宣; 孙玉坤; 张亮; 姚沼林; 黄永红

    2016-01-01

    The inverter circuit of grid-connected PV system and the parallel APF have many similarities in topological structure, operation mode and control method, based on this, a new kind of control method which can combine the reactive compensation and active filter with grid-connected PV power generation is put forward. Using FBD current detection method, the instantaneous reactive and harmonic current detection can be realized without complex Park transform ord-qtransform. Combining with the neutral point clamped (NPC) three-level quasi-PR control strategy, static error free tracking control of the alternating current signal in static coordinates can be realized. The control algorithm has been greatly simplified while the harmonic of grid current has been effectively reduced, at the same time, the robustness of the system has been enhanced. The simulation and experimental results show that the proposed control strategy can effectively suppress harmonics as well as achieve the compensation control of grid-connected PV generation and reactive compensation.%为提高光伏并网电能质量,基于光伏并网发电系统逆变主电路和并联型APF在拓扑结构、运行方式和控制方法上具有诸多相同点,提出一种将有源滤波和无功功率补偿与光伏并网发电相结合的新型控制方案。该方案利用 FBD 电流检测法,无需复杂的Park变换和d-q变换,即可实现瞬时谐波和无功电流的检测。结合中点箝位式(NPC)三电平准 PR 控制策略,即可完成对交变电流信号在静止坐标系下的无静差跟踪控制,在简化控制算法的同时大大减小了并网电流的谐波含量,且增强了系统的鲁棒性。仿真及实验结果表明,所提控制策略可有效地实现光伏并网发电和有源滤波及无功功率补偿的统一控制。

  14. PV-powered microirrigation systems

    Energy Technology Data Exchange (ETDEWEB)

    Matlin, R. W.

    1979-01-01

    Tens of millions of farmers currently subsist on small farms below two hectares in size. The increasing cost of animal irrigation coupled with decreasing farm size and the lack of a utility grid or acceptable alternate power sources is causing interest in the use of solar photovoltaic for these very small (subkilowatt) water pumping systems. The attractive combinations of system components (array, pump, motor, storage, and controls) have been identified and their interactions characterized in order to optimize overall system efficiency. Computer simulations as well as component tests were made of systems utilizing flat plate and low concentration arrays, direct-coupled and electronic impedance matching controls, fixed and incremental (once or twice a day) tracking, dc and ac motors, and positive displacement, centrifugal and verticle turbine pumps. The results of these analyses and tests are presented for Orissa, India and Cairo, Egypt, and include water volume pumped as a function of time of day and year. Finally, a description and operational data is given for the prototype unit that was developed as a result of the previous analyses and tests.

  15. Design optimization of transformerless grid-connected PV inverters including reliability

    DEFF Research Database (Denmark)

    Koutroulis, Eftichios; Blaabjerg, Frede

    2012-01-01

    This paper presents a new methodology for optimal design of transformerless Photovoltaic (PV) inverters targeting a cost-effective deployment of grid-connected PV systems. The optimal values and types of the PV inverter components are calculated such that the PV inverter Levelized Cost Of the Ele......This paper presents a new methodology for optimal design of transformerless Photovoltaic (PV) inverters targeting a cost-effective deployment of grid-connected PV systems. The optimal values and types of the PV inverter components are calculated such that the PV inverter Levelized Cost...... to the non-optimized PV inverter structures, the PV inverters designed using the proposed optimization methodology exhibit lower total manufacturing and lifetime maintenance cost and inject more energy into the electric-grid and by that minimizing LCOE....

  16. Storage Application in Smart Grid with High PV and EV Penetration

    DEFF Research Database (Denmark)

    Hashemi Toghroljerdi, Seyedmostafa; Yang, Guangya; Østergaard, Jacob

    2013-01-01

    grids with residential PVs and Electric Vehicles (EVs). The effect of EV home charging on EESS capacity in high PV penetration is also addressed. The results indicate that increasing the EV penetration in the network can decrease the EESS capacity need. This decrease is highest in situations with low PV......Rapid deployment of renewable energy sources (RES) and concerns regarding their impacts on power systems provide new opportunities for utilizing more electrical energy storage system (EESS) in power systems. Peak-shaving in high Photovoltaic (PV) penetration conditions and providing ancillary...... service in high load conditions are among the applications of EESS in distribution systems. In this paper, a new method is developed based on the voltage sensitivity analysis of the network in order to calculate the EESS capacity required for prevention of voltage rise and voltage drop in distribution...

  17. Fuzzy comprehensive evaluation for grid-connected performance of integrated distributed PV-ES systems

    Science.gov (United States)

    Lv, Z. H.; Li, Q.; Huang, R. W.; Liu, H. M.; Liu, D.

    2016-08-01

    Based on the discussion about topology structure of integrated distributed photovoltaic (PV) power generation system and energy storage (ES) in single or mixed type, this paper focuses on analyzing grid-connected performance of integrated distributed photovoltaic and energy storage (PV-ES) systems, and proposes a comprehensive evaluation index system. Then a multi-level fuzzy comprehensive evaluation method based on grey correlation degree is proposed, and the calculations for weight matrix and fuzzy matrix are presented step by step. Finally, a distributed integrated PV-ES power generation system connected to a 380 V low voltage distribution network is taken as the example, and some suggestions are made based on the evaluation results.

  18. Single-Phase Single-Stage PV-Grid System Using VSI Based on Simple Control Circuit

    Directory of Open Access Journals (Sweden)

    Slamet Riyadi

    2012-12-01

    Full Text Available Integrating electric energy generated by PV with utilities has been developed. Some of these using two-stage converters and the others using single stage converters. For systems with two-stage converters, the first stage converter acts as a MPPT to maximize power generated by PV and the second stage is used as an interface to the utilities. In the single-stage system, an inverter is used for both function. In this paper, PV-Grid System using a single-stage Voltage Source Inverter is proposed. The simple control circuit to make PV generate maximum power and keeping power equilibrium between PV and inverter output power is used. To verify the analysis, simulations are done.

  19. Power Quality Real-time Grid-connected PV Plant Monitoring System%并网光伏电站电能质量实时监测系统

    Institute of Scientific and Technical Information of China (English)

    杜金其; 周林

    2013-01-01

    并网光伏电站的电能质量问题已经成为制约光伏发电技术发展的关键因素之一,进行实时电能质量监测有助于光伏发电技术的改进和提高,对于保障电网安全稳定运行具有重大意义.文中开发了一种基于虚拟仪器的并网光伏电站电能质量实时监测系统,该系统实现了对并网光伏电站电能质量三项稳态指标的监测,利用LabSQL模块和数据库技术实现数据存储以及基于C/S模式、B/S模式和Remote Panels技术的信息远程发布方案,使监控中心可通过Internet直接查看即时和历史电能质量数据,实现信息共享.同时利用7.68 kWp光伏电站对文中开发的系统进行验证,试验结果表明该系统能满足实时、准确、长期、连续的实际测量需要.%Power quality of grid-connected PV plant has been one of the key factors which restricted the development of photovoltaic technology.So the supervision of the plant is to improve and enhance the photovoltaic technology and ensure grid security and stability.This paper presented a power quality real-time monitoring system based on LabVIEW,the system can satisfy the requirement of monitoring three steady targets for power quality.This paper proposed the mode of the remote data storage based on the LabSQL module and database technology,meanwhile,information transmission scheme based on the C/S mode,the B/S mode and remote panels technology.Monitoring center can inquire the data of power quality through the Internet.This system was verified by 7.68 kW grid-connected PV system,the test results show that the system could meet the need of actual measurement.

  20. 国内外光伏并网标准中电能质量相关规范对比与分析%The Comparison and Analysis on Specifications of Power Quality in Standards of PV Grid-Connected System at Home and Abroad

    Institute of Scientific and Technical Information of China (English)

    刘燕华; 张楠; 赵冬梅

    2011-01-01

    The utilization of photovoltaic generation has promoted the development of new criteria for PV grid-connected system. In this paper, by referencing the advantages of relative criteria of other countries, the criteria of PV generation grid-connected system in China are improved based on international mature criteria and that of other countries. At first, the existing criteria of PV grid-connected system are introduced, and the influence of PV grid-connected system on the power quality of power grid is analyzed. In addition, the relative specifications and criteria of power quality are compared, and results show that criteria of PV grid-connected system in every country and area are different. The reason that causes these difference is that the difference of power structures and PV system capacity in every country and area. The work of this paper will be beneficial to improve PV product level of our country, and to strengthen competition with other countries, which has value for establishing the specifications of power quality in criteria of PV grid-connected system.%太阳能光伏发电的应用推动了新的光伏并网标准的发展,借鉴其他国家相关标准的优点,并参考国际和其他国家成熟的光伏发电并网标准完善国内太阳能光伏发电并网标准.首先介绍了国内外现行光伏并网标准,然后分析太阳能光伏并网对电网电能质量带来的影响,并针对电能质量相关规范和准则进行了比较,结果表明各个国家和地区的光伏并网标准有区别,最后分析其产生原因,主要是由于各个国家和地区的电网结构和光伏系统容量大小有所不同.研究结果有利于提高我国光伏产业水平,增强我国参与国际竞争的实力,可以为制定中国光伏并网标准中电能质量相关规范提供有益参考.

  1. Performance of a grid connected PV system used as active filter

    Energy Technology Data Exchange (ETDEWEB)

    Calleja, H. [Cenidet, Morelos (Mexico). Electronics Dept.; Jimenez, H. [IIE, Morelos (Mexico). Conventional Energy Sources Dept.

    2004-09-01

    In this paper, the performance of a grid connected photovoltaic (PV) system used as an active filter is presented. its main feature is the capability to compensate the reactive and harmonic currents drawn by nonlinear loads while simultaneously injecting into the grid the maximum power available from the cells. The system can also operate as a stand alone active filter. The system was connected to a 1 kW PV array and tested with the loads typically found in households: small motors, personal computers and electronic ballasts. The results show that the system can correct the power factor to values close to unity for all the cases tested, thereby improving the efficiency of the electric energy supply. (author)

  2. Improved Reliability of Single-Phase PV Inverters by Limiting the Maximum Feed-in Power

    DEFF Research Database (Denmark)

    Yang, Yongheng; Wang, Huai; Blaabjerg, Frede

    2014-01-01

    . The CPG control strategy is activated only when the DC input power from PV panels exceeds a specific power limit. It enables to limit the maximum feed-in power to the electric grids and also to improve the utilization of PV inverters. As a further study, this paper investigates the reliability performance...... of the power devices (e.g. IGBTs) used in PV inverters with the CPG control under different feed-in power limits. A long-term mission profile (i.e. solar irradiance and ambient temperature) based stress analysis approach is extended and applied to obtain the yearly electrical and thermal stresses of the power...

  3. Design for grid-connected power optimization control scheme of micro PV system%微型光伏发电系统并网电能优化控制方案

    Institute of Scientific and Technical Information of China (English)

    冯旭阳; 杨育刚; 武彬

    2014-01-01

    To study micro-grid-connected PV systems,a grid-connected power forecasting model has been established based on the least square support vector machine.On this basis,a power optimization control scheme is proposed for demand-side load electricity management to improve the utilization of photovoltaic electricity and reduce usage of electricity gotten from the grid.Calculation and analysis of the scheme show that the scheme can reduce user's power consumption from distribution networks up to 10.36%,and daily average reduction of carbon emissions is 618.8 kg.The scheme ensures utilization of solar energy effectively,and improves energy saving capabilities of the system.%以微型光伏并网发电系统为研究对象,基于最小二乘支持向量机建立了光伏并网发电系统电能预测LS-SVM模型.在此基础上,以减少用户从电网获取电能,提高光伏电能利用率为目标,针对需求侧负荷用电管理,提出一种电能优化控制方案.通过实例计算分析显示,该方案可使用户从配电网获取电能减少10.36%,平均日减少碳排放量约618.8 kg,在保证光伏电能就地有效利用的同时,有效地提高了系统节能减排能力.

  4. Control and Modulation Techniques for a Centralized PV Generation System Grid Connected via an Interleaved Inverter

    Directory of Open Access Journals (Sweden)

    Gianluca Brando

    2016-09-01

    Full Text Available In the context of grid connected photovoitaic (PV generation systems, there are two paramount aspects regarding the Maximum Power Point Tracking (MPPT of the photovoltaic units and the continuity of the service. The most diffused MPPT algorithms are based on either perturb and observe, or on an incremental conductance approach and need both PV current and voltage measurements. Several topology reconfigurable converters are also associated with the PV plants, guaranteeing fault-tolerant features. The generation continuity can also be assured by interleaved inverters, which keep the system operating at reduced maximum power in case of failure. In this paper, an evolution of a hysteresis based MPPT algorithm is presented, based on the measurement of only one voltage, together with a novel space vector modulation suitable for a two-channel three-phase grid connected interleaved inverter. The proposed MMPT algorithm and modulation technique are tested by means of several numerical analyses on a PV generation system of about 200 kW maximum power. The results testify the validity of the proposed strategies, showing good performance, even during a fault occurrence and in the presence of deep shading conditions.

  5. POWERED LED LIGHTING SUPPLIED FROM PV CELLS

    Directory of Open Access Journals (Sweden)

    Tirshu M.

    2011-12-01

    Full Text Available The paper deals with practical realization of efficient lighting system based on LED’s of 80W total power mounted on corridor ceiling total length of which is 120m and substitutes existing traditional lighting system consisting of 29 lighting blocks with 4 fluorescent lamps each of them and summary power 2088W. Realized lighting system is supplied from two photovoltaic panels of power 170W. Generated energy by PV cells is accumulated in two accumulators of 75Ah capacity and from battery by means of specialized convertor is applied to lighting system. Additionally, paper present data measured by digital weather station (solar radiation and UV index, which is mounted near of PV cells and comparative analyze of solar energy with real energy generated by PV cells is done. Measured parameters by digital weather station are stored by computer in on-line mode.

  6. High Efficiency Single-stage Grid-tied PV Inverter for Renewable Energy System

    OpenAIRE

    2012-01-01

    A single-phase grid connected transformerless photovoltaic (PV) inverter for residential application is presented. The inverter is derived from a boost cascaded with buck converter along with a line frequency unfolding circuit. Due to its novel operating modes, high efficiency can be achieved because there is only one switch operating at high frequency at a time, and the converter allows the use of power MOSFET and ultra-fast reverse recovery diode. This dissertation begins with theoretical a...

  7. Development and Testing of a Prototype Grid-Tied Photovoltaic Power System

    Science.gov (United States)

    Eichenberg, Dennis J.

    2009-01-01

    The NASA Glenn Research Center (GRC) has developed and tested a prototype 2 kW DC grid-tied photovoltaic (PV) power system at the Center. The PV system has generated in excess of 6700 kWh since operation commenced in July 2006. The PV system is providing power to the GRC grid for use by all. Operation of the prototype PV system has been completely trouble free. A grid-tied PV power system is connected directly to the utility distribution grid. Facility power can be obtained from the utility system as normal. The PV system is synchronized with the utility system to provide power for the facility, and excess power is provided to the utility. The project transfers space technology to terrestrial use via nontraditional partners. GRC personnel glean valuable experience with PV power systems that are directly applicable to various space power systems, and provide valuable space program test data. PV power systems help to reduce harmful emissions and reduce the Nation s dependence on fossil fuels. Power generated by the PV system reduces the GRC utility demand, and the surplus power aids the community. Present global energy concerns reinforce the need for the development of alternative energy systems. Modern PV panels are readily available, reliable, efficient, and economical with a life expectancy of at least 25 years. Modern electronics has been the enabling technology behind grid-tied power systems, making them safe, reliable, efficient, and economical with a life expectancy of at least 25 years. Based upon the success of the prototype PV system, additional PV power system expansion at GRC is under consideration. The prototype grid-tied PV power system was successfully designed and developed which served to validate the basic principles described, and the theoretical work that was performed. The report concludes that grid-tied photovoltaic power systems are reliable, maintenance free, long life power systems, and are of significant value to NASA and the community.

  8. Maximum Power Point Tracking and Reactive Power Control of Single Stage Grid Connected Photovoltaic System

    OpenAIRE

    2011-01-01

    Single-stage grid-connected Photovoltaic (PV) systems have advantages such as simple topology, high efficiency, etc. However, since all the control objectives such as the maximum power point tracking (with the utility voltage, and harmonics reduction for output current need to be considered simultaneously, the complexity of the control scheme is much increased. In this paper a new type of grid connected photovoltaic (PV) system with Maximum Power Point Tracking (MPPT) and reactive power simul...

  9. S4 Grid-Connected Single-Phase Transformerless Inverter for PV Application

    DEFF Research Database (Denmark)

    Ardashir, Jaber Fallah; Siwakoti, Yam Prasad; Sabahi, Mehran;

    2016-01-01

    This paper introduces a new single-phase transformerless inverter for grid-connected photovoltaic systems with low leakage current. It consists of four power switches, two diodes, two capacitors and a filter at the output stage. The neutral of the grid is directly connected to the negative termin...... clearly verify the performance of the proposed inverter and its practical application for grid-connected PV systems.......This paper introduces a new single-phase transformerless inverter for grid-connected photovoltaic systems with low leakage current. It consists of four power switches, two diodes, two capacitors and a filter at the output stage. The neutral of the grid is directly connected to the negative terminal...... of the PV source. This results in a constant common-mode voltage and almost zero leakage current. A unipolar Sinusoidal Pulse-Width Modulation (SPWM) technique is used to modulate the inverter to reduce the output current ripple and the filter requirements. The main advantages of this inverter are compact...

  10. 正序基波提取器在光伏并网功率调节系统中的应用%Positive-sequence fundamental wave extractor applied in the PV grid-connected power conditioning system

    Institute of Scientific and Technical Information of China (English)

    杨艺云; 司传涛; 廖波; 周林

    2013-01-01

    The key for PV grid-connected power conditioning system to realize the uniform control of PV grid-connected and active filter is to correctly detect harmonic and reactive current and form grid-connected directive current. Considering distortion and frequency deviation of the actual grid voltage, to get the correct harmonic, reactive current and synchronous sine, the amplitude integral and selective characteristic of frequency are used to form the positive sequence fundamental extractor. The K in the positive sequence fundamental extractor is further analyzed, and then the operation expression of K is derived. If K is chosen properly, positive-sequence fundamental can be got correctly, and synchronous sine and cosine can be got without the phase lock loop. The detecting method for the harmonic, reactive power, and the sum of unsymmetrical components, as well as the grid-connected directive current composing method is analyzed to realize the active power injection, harmonic eliminating and reactive power compensation. The simulation in Matlab/Simulink verifies the correctness of the theoretical analysis. For the effect of K on the positive-sequence fundamental extracting, the miniwatt experiment is conducted to further verify the correctness of the method.%光伏并网功率调节系统实现光伏并网与有源滤波的统一控制,关键是谐波、无功电流的准确检测和并网指令电流的形成。考虑实际电网电压有畸变或频率偏差,为获得准确谐波、无功电流和同步正弦,利用幅值积分及其频率选择特性构成正序基波提取器,深入分析正序基波提取器中K参数设计方法,推导出K值的计算表达式,合理取K值,可准确提取正序基波,无需锁相环可得到同步正、余弦信号。分析了谐波、无功及不对称分量之和的检测方法和并网指令电流的合成方式,实现光伏有功注入与谐波抑制、无功补偿功能。最后进行Matlab/Simulink仿真

  11. Highlight of Grid-connected PV systems in administrative buildings in Egypt

    Directory of Open Access Journals (Sweden)

    Dina Said

    2017-03-01

    Full Text Available Solar energy applications are becoming increasingly common in Egypt. The abundant sunshine in Egypt, as well as the increasing competitiveness of solar energy systems including- but not limited to photovoltaic (PV, – predicts that these technologies could be weighed to be raised in Egypt.PV systems are installed on roof tiles or other parts of building structures to supplement grid utility, reduce electric bills, and provide emergency back–up energy. Moreover, they simultaneously reduce significant amounts of CO2 emissions. It is foreseen, a number of residential and public buildings in Egypt are using solar power to cut electric utility bills significantly. The approximately payback period to recover the investment costs for PV systems is up to about 5 years.  In addition, it is more economical to use PV system than grid utility systems. The two components that determine the total initial price of a grid- connected PV system are the modules and the balance of systems (BOS. The BOS includes different components such as mounting frames, inverters and site- specific installation hardware.The Government of Egypt (GOE has endorsed the deployment of PV systems through three approaches. It started with a prime minister decree to install PV projects on one-thousand of the governmental buildings. This was followed by as an initiative called "Shamsk ya Masr", and finally the Feed-in Tariff (FiT projects.Following the prime minster decree the Egyptian Electricity Holding Company (EEHC and its affiliated companies took the lead to install PV systems at the top roof of their administrative buildings and interconnect these systems to the electricity network where the suitable locations have been selected for mounting them. About 90 PV systems have been already mounted with about a capacity of 9 MW. On the other hand, "Shamsk ya Masr" has considered energy efficiency (EE so as to complement the PV systems, which will be installed on administrative

  12. Modular Power Converters for PV Applications

    Energy Technology Data Exchange (ETDEWEB)

    Ozpineci, Burak [ORNL; Tolbert, Leon M [ORNL

    2012-05-01

    This report describes technical opportunities to serve as parts of a technological roadmap for Shoals Technologies Group in power electronics for PV applications. There are many different power converter circuits that can be used for solar inverter applications. The present applications do not take advantage of the potential for using common modules. We envision that the development of a power electronics module could enable higher reliability by being durable and flexible. Modules would have fault current limiting features and detection circuits such that they can limit the current through the module from external faults and can identify and isolate internal faults such that the remaining modules can continue to operate with only minimal disturbance to the utility or customer. Development of a reliable, efficient, low-cost, power electronics module will be a key enabling technology for harnessing more power from solar panels and enable plug and play operation. Power electronics for computer power supplies, communication equipment, and transportation have all targeted reliability and modularity as key requirements and have begun concerted efforts to replace monolithic components with collections of common smart modules. This is happening on several levels including (1) device level with intelligent control, (2) functional module level, and (3) system module. This same effort is needed in power electronics for solar applications. Development of modular units will result in standard power electronic converters that will have a lower installed and operating cost for the overall system. These units will lead to increased adaptability and flexibility of solar inverters. Incorporating autonomous fault current limiting and reconfiguration capabilities into the modules and having redundant modules will lead to a durable converter that can withstand the rigors of solar power generation for more than 30 years. Our vision for the technology roadmap is that there is no need

  13. Modular Power Converters for PV Applications

    Energy Technology Data Exchange (ETDEWEB)

    Ozpineci, Burak [ORNL; Tolbert, Leon M [ORNL

    2012-05-01

    This report describes technical opportunities to serve as parts of a technological roadmap for Shoals Technologies Group in power electronics for PV applications. There are many different power converter circuits that can be used for solar inverter applications. The present applications do not take advantage of the potential for using common modules. We envision that the development of a power electronics module could enable higher reliability by being durable and flexible. Modules would have fault current limiting features and detection circuits such that they can limit the current through the module from external faults and can identify and isolate internal faults such that the remaining modules can continue to operate with only minimal disturbance to the utility or customer. Development of a reliable, efficient, low-cost, power electronics module will be a key enabling technology for harnessing more power from solar panels and enable plug and play operation. Power electronics for computer power supplies, communication equipment, and transportation have all targeted reliability and modularity as key requirements and have begun concerted efforts to replace monolithic components with collections of common smart modules. This is happening on several levels including (1) device level with intelligent control, (2) functional module level, and (3) system module. This same effort is needed in power electronics for solar applications. Development of modular units will result in standard power electronic converters that will have a lower installed and operating cost for the overall system. These units will lead to increased adaptability and flexibility of solar inverters. Incorporating autonomous fault current limiting and reconfiguration capabilities into the modules and having redundant modules will lead to a durable converter that can withstand the rigors of solar power generation for more than 30 years. Our vision for the technology roadmap is that there is no need

  14. Design Optimization of Transformerless Grid-Connected PV Inverters Including Reliability

    DEFF Research Database (Denmark)

    Koutroulis, Eftichios; Blaabjerg, Frede

    2013-01-01

    This paper presents a new methodology for optimal design of transformerless photovoltaic (PV) inverters targeting a cost-effective deployment of grid-connected PV systems. The optimal switching frequency as well as the optimal values and types of the PV inverter components is calculated such that......This paper presents a new methodology for optimal design of transformerless photovoltaic (PV) inverters targeting a cost-effective deployment of grid-connected PV systems. The optimal switching frequency as well as the optimal values and types of the PV inverter components is calculated...... that compared to the nonoptimized PV inverter structures, the PV inverters designed using the proposed optimization methodology exhibit lower total manufacturing and lifetime maintenance cost and inject more energy into the electric-grid and by that minimizing LCOE....

  15. Quantification, challenges and outlook of PV integration in the power system: a review by the European PV Technology Platform

    DEFF Research Database (Denmark)

    Alet, Pierre-Jean; Baccaro, Federica; De Felice, Matteo;

    2015-01-01

    Integration in the power system has become a limiting factor to the further development of photovoltaics. Proper quantification is needed to evaluate both issues and solutions; the share of annual electricity demand is widely used but we found that some of the metrics which are related to power...... rather than energy better reflect the impact on networks. Barriers to wider deployment of PV into power grids can be split between local technical issues (voltage levels, harmonics distortion, reverse power flows and transformer loading) and system-wide issues (intermittency, reduction of system...... networks. Forecasting, storage, and combination with other renewable sources are interdependent solutions to solve the intermittency issue. Finally, we found that PV is also an opportunity to reduce some investment required to upgrade existing power networks. Through integration with micro-grids and hybrid...

  16. Quantification, challenges and outlook of PV integration in the power system: a review by the European PV Technology Platform

    DEFF Research Database (Denmark)

    Alet, Pierre-Jean; Baccaro, Federica; De Felice, Matteo;

    2015-01-01

    rather than energy better reflect the impact on networks. Barriers to wider deployment of PV into power grids can be split between local technical issues (voltage levels, harmonics distortion, reverse power flows and transformer loading) and system-wide issues (intermittency, reduction of system......Integration in the power system has become a limiting factor to the further development of photovoltaics. Proper quantification is needed to evaluate both issues and solutions; the share of annual electricity demand is widely used but we found that some of the metrics which are related to power...... networks. Forecasting, storage, and combination with other renewable sources are interdependent solutions to solve the intermittency issue. Finally, we found that PV is also an opportunity to reduce some investment required to upgrade existing power networks. Through integration with micro-grids and hybrid...

  17. Sensorless Reserved Power Control Strategy for Two-Stage Grid-Connected Photovoltaic Systems

    DEFF Research Database (Denmark)

    Sangwongwanich, Ariya; Yang, Yongheng; Blaabjerg, Frede

    2016-01-01

    Due to still increasing penetration level of grid-connected Photovoltaic (PV) systems, advanced active power control functionalities have been introduced in grid regulations. A reserved power control, where the active power from the PV panels is reserved during operation, is required for grid...... to achieve the power reserve. In this method, the irradiance measurements that have been used in conventional control schemes to estimate the available PV power are not required, and thereby being a sensorless solution. Simulations and experimental tests have been performed on a 3-kW two-stage single...... support. In this paper, a cost-effective solution to realize the reserved power control for grid-connected PV systems is proposed. The proposed solution routinely employs a Maximum Power Point Tracking (MPPT) control to estimate the available PV power and a Constant Power Generation (CPG) control...

  18. Suggested Grid Code Modifications to Ensure Wide-Scale Adoption of Photovoltaic Energy in Distributed Power Generation Systems

    DEFF Research Database (Denmark)

    Yang, Yongheng; Enjeti, Prasad; Blaabjerg, Frede;

    2013-01-01

    -phase PV systems in the distributed grid, the disconnection under grid faults can contribute to: a) voltage flickers, b) power outages, and c) system instability. In this paper, grid code modifications are explored for wide-scale adoption of PV systems in the distribution grid. More recently, Italy......Current grid standards seem to largely require low power (e.g. several kilowatts) single-phase photovoltaic (PV) systems to operate at unity power factor with maximum power point tracking, and disconnect from the grid under grid faults. However, in case of a wide-scale penetration of single...... and Japan, have undertaken a major review of standards for PV power conversion systems connected to low voltage networks. In view of this, the importance of low voltage ride-through for single-phase PV power systems under grid faults along with reactive power injection is studied in this paper. Three...

  19. Policies and opportunities for grid parity of PV in the Netherlands

    Energy Technology Data Exchange (ETDEWEB)

    Lako, P.; Beurskens, L.W.M. [ECN Policy Studies, Petten (Netherlands)

    2012-01-15

    In 2010, ECN Policy Studies has provided information on the development of solar PV in the Netherlands to GlobalData, India. Based on this information request, the present note on policies and opportunities for grid parity of PV has been drafted. Recently, subsidies for solar PV in the Netherlands have shown a pattern of a roller-coaster that is typical for PV financing in a number of EU countries. Stop-and-go policies for solar PV may have multiple causes. It may be difficult to determine the right feed-in tariffs for PV; or governments may be reluctant to provide sufficient funding for a relatively expensive renewable electricity source like PV. This note sheds light on the current state of affairs and policies for PV in the Netherlands, and on several private initiatives aimed at reaching grid parity for PV which is installed by households.

  20. Time series power flow analysis for distribution connected PV generation.

    Energy Technology Data Exchange (ETDEWEB)

    Broderick, Robert Joseph; Quiroz, Jimmy Edward; Ellis, Abraham; Reno, Matthew J.; Smith, Jeff; Dugan, Roger

    2013-01-01

    Distributed photovoltaic (PV) projects must go through an interconnection study process before connecting to the distribution grid. These studies are intended to identify the likely impacts and mitigation alternatives. In the majority of the cases, system impacts can be ruled out or mitigation can be identified without an involved study, through a screening process or a simple supplemental review study. For some proposed projects, expensive and time-consuming interconnection studies are required. The challenges to performing the studies are twofold. First, every study scenario is potentially unique, as the studies are often highly specific to the amount of PV generation capacity that varies greatly from feeder to feeder and is often unevenly distributed along the same feeder. This can cause location-specific impacts and mitigations. The second challenge is the inherent variability in PV power output which can interact with feeder operation in complex ways, by affecting the operation of voltage regulation and protection devices. The typical simulation tools and methods in use today for distribution system planning are often not adequate to accurately assess these potential impacts. This report demonstrates how quasi-static time series (QSTS) simulation and high time-resolution data can be used to assess the potential impacts in a more comprehensive manner. The QSTS simulations are applied to a set of sample feeders with high PV deployment to illustrate the usefulness of the approach. The report describes methods that can help determine how PV affects distribution system operations. The simulation results are focused on enhancing the understanding of the underlying technical issues. The examples also highlight the steps needed to perform QSTS simulation and describe the data needed to drive the simulations. The goal of this report is to make the methodology of time series power flow analysis readily accessible to utilities and others responsible for evaluating

  1. 3G POWER GRID SYSTEM

    OpenAIRE

    Saiyad Tausif Ali *; Gaurav Pawar; Pragati Rathi; Mandar Pathak

    2016-01-01

    3G Power grid system is dual side stream of electricity and automated construct information and distributed advanced energy delivery network. In this 3G Power grid system avoided the thermal and hydro sources of energy. By using the solar power and wind power energy will generate electricity according with the condition of nature. 3G Power grid system provides the facility of generating as well as marketing of electricity not only for the producers but also for consumers. By using megabytes o...

  2. Rating PV Power and Energy: Cell, Module, and System Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Emery, Keith

    2016-06-02

    A summary of key points related to research-level measurements of current vs. voltage measurement theory including basic PV operation, equivalent circuit, and concept of spectral error; PV power performance including PV irradiance sensors, simulators and commercial and generic I-V systems; PV measurement artifacts, intercomparisons, and alternative rating methods.

  3. Smart power grids 2011

    CERN Document Server

    Keyhani, Ali

    2012-01-01

    Electric power systems are experiencing significant changes at the worldwide scale in order to become cleaner, smarter, and more reliable. This edited book examines a wide range of topics related to these changes, which are primarily caused by the introduction of information technologies, renewable energy penetration, digitalized equipment, new operational strategies, and so forth. The emphasis will be put on the modeling and control of smart grid systems. This book addresses research topics such as high efficiency transforrmers, wind turbines and generators, fuel cells, or high speed turbines

  4. 光伏电站接入对电能质量的影响及其对策措施研究%Research on Effect of Grid-connected PV Station on Power Quality and Countermeasures

    Institute of Scientific and Technical Information of China (English)

    李自鹏; 陆畅; 沈攀; 李红; 韩杨

    2015-01-01

    大规模光伏发电系统在新能源的发展中有着十分重要的地位。首先,分析了大规模光伏发电系统的特点,重点阐述了光伏发电对电能质量造成的主要影响以及其原因;然后,为了更好地研究光伏并网系统的稳定性,接着讨论了大规模光伏建模的动态以及静态模型;同时分析了谐波、电压质量对电能质量的影响,讨论了电网非对称故障情况下的过电压/过电流问题以及低压穿越技术和孤岛监测技术等;最后,总结了国内外相关的对策和措施,为大规模光伏并网发电系统的规划、仿真、以及控制策略等提供了相应的参考。%Large-scale grid-connected solar generation system plays an important role in the development of new energy sources. Firstly, this paper analysis the characteristics of large-scale photovoltaic power generation system, and the main impacts on the power grid with large-scale PV integration are elaborated. In addition , this paper also reviews the dynamic and static models for better stability studies, and the influence of the harmonic and voltage quality on the power quality is analyzed, the overvoltage/overcurrent problems under unbalanced grid faults, low voltage ride through (LVRT) technology and islanding detection technology are also presented. Finally, the corresponding solutions and countermeasures are summarizes, and the references are offered to readers from the perspective of power system planning, simulation and control strategy.

  5. Tools for Enhanced Grid Operation and Optimized PV Penetration Utilizing Highly Distributed Sensor Data.

    Energy Technology Data Exchange (ETDEWEB)

    Reno, Matthew J. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Peppanen, Jouni [Georgia Inst. of Technology, Atlanta, GA (United States); Seuss, John [Georgia Inst. of Technology, Atlanta, GA (United States); Lave, Matthew Samuel [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Broderick, Robert Joseph [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Grijalva, Santiago [Georgia Inst. of Technology, Atlanta, GA (United States)

    2015-11-01

    Increasing number s of PV on distribution systems are creating more grid impacts , but it also provides more opportunities for measurement, sensing, and control of the grid in a distributed fashion. This report demonstrates three software tools for characterizing and controlling distribution feeders by utilizing large numbers of highly distributed current, voltage , and irradiance sensors. Instructions and a user manual is presented for each tool. First, the tool for distribution system secondary circuit parameter estimation is presented. This tool allows studying distribution system parameter estimation accuracy with user-selected active power, reactive power, and voltage measurements and measurement error levels. Second, the tool for multi-objective inverter control is shown. Various PV inverter control strategies can be selected to objectively compare their impact on the feeder. Third, the tool for energy storage for PV ramp rate smoothing is presented. The tool allows the user to select different storage characteristics (power and energy ratings) and control types (local vs. centralized) to study the tradeoffs between state-of-charge (SOC) management and the amount of ramp rate smoothing.

  6. A New Technique for Tracking the Global Maximum Power Point of PV Arrays Operating Under Partial-Shading Conditions

    DEFF Research Database (Denmark)

    Koutroulis, Eftichios; Blaabjerg, Frede

    2012-01-01

    output, such that it behaves as a constant input-power load. The proposed method has the advantage that it can be applied in either stand-alone or grid-connected PV systems comprising PV arrays with unknown electrical characteristics and does not require knowledge about the PV modules configuration......The power-voltage characteristic of photovoltaic (PV) arrays operating under partial-shading conditions exhibits multiple local maximum power points (MPPs). In this paper, a new method to track the global MPP is presented, which is based on controlling a dc/dc converter connected at the PV array...

  7. A Cost-Effective Power Ramp-Rate Control Strategy for Single-Phase Two-Stage Grid-Connected Photovoltaic Systems

    DEFF Research Database (Denmark)

    Sangwongwanich, Ariya; Yang, Yongheng; Blaabjerg, Frede

    2016-01-01

    In the case of a wide-scale adoption of grid-connected Photovoltaic (PV) systems, more fluctuated power will be injected into the grid due to the intermittency of solar PV energy. A sudden change in the PV power can potentially induce grid voltage fluctuations, and thus challenge the stability...

  8. Synchrony-optimized power grids

    CERN Document Server

    Pinto, Rafael S

    2014-01-01

    We investigate synchronization in power grids, which we assume to be modeled by a network of Kuramoto oscillators with inertia. More specifically, we study the optimization of the power grid topology to favor the network synchronization. We introduce a rewiring algorithm which consists basically in a hill climb scheme where the edges of the network are swapped in order enhance the main measures of synchronization. As a byproduct of the optimization algorithm, we typically have also the anticipation of the synchronization onset for the optimized network. We perform several robustness tests for the synchrony-optimized power grids, including the impact of consumption peaks. In our analyses, we investigate synthetic random networks, which we consider as hypothetical decentralized power generation situations, and also a network based in the actual power grid of Spain, which corresponds to the current paradigm of centralized power grids. The synchrony-optimized power grids obtained by our algorithm have some intere...

  9. DESIGN & IMPLEMENTATION OF AN INTELLIGENT SOLAR HYBRID INVERTER IN GRID ORIENTED SYSTEM FOR UTILIZING PV ENERGY

    Directory of Open Access Journals (Sweden)

    MASUDUL HAIDER IMTIAZ

    2010-12-01

    Full Text Available This paper demonstrates the implementation of a prototype of IPS (instant power supply system to ensure continuous output current to load in residential application utilizing both Photovoltaic (PV energy and AC Grid. Utility interfacing PWM inverter designed here to operate by both solar energy and storage batteries that highly satisfies the necessity in rural areas where National Grids are hardly available and power cut problem reduces the effectiveness of IPS. Solar energy gets priority here to charge storage battery rather than AC source that may save hundreds of mega watts power every day. To extend the battery lifetime and keep system components hazard-free, it includes exact battery-level sensing, charging- urrent controlling by microcontroller unit (MCU and a cumulative DC/AC MPPT (Maximum Power Point Tracking charging to congregatemaximum PV energy from AC Solar Modules. Investigation on improvement of power-interfacing control and optimization of overall system operation assent to intend usage recommendation in this exposition. Computer simulations and experiment results show the validity of this proposed system to have high power conversion efficiency and low harmonic distortions.

  10. Reliability Analysis of Single-Phase PV Inverters with Reactive Power Injection at Night Considering Mission Profiles

    DEFF Research Database (Denmark)

    Anurag, Anup; Yang, Yongheng; Blaabjerg, Frede

    2015-01-01

    The widespread adoption of mixed renewables urgently require reactive power exchange at various feed-in points of the utility grid. Photovoltaic (PV) inverters are able to provide reactive power in a decentralized manner at the grid-connection points even outside active power feed-in operation......, especially at night when there is no solar irradiance. This serves as a motivation for utilizing the PV inverters at night for reactive power compensation. Thus, an analysis on the impact of reactive power injection by PV inverters outside feed-in operation on the thermal performance and the reliability has...

  11. On Robustness of Power Grids

    NARCIS (Netherlands)

    Koç, Y.

    2015-01-01

    Current and future trends in environmental, economical, and human-caused factors (such as power demand growth, over-ageing of assets in power grids, and extreme weather conditions) challenge power grid robustness in the near future, necessitating research to better analyse and understand the notion

  12. Sacramento Municipal Utility District PV and Smart Grid Pilot at Anatolia

    Energy Technology Data Exchange (ETDEWEB)

    Rawson, Mark; Sanchez, Eddie Paul

    2013-12-30

    Under DE-FOA-0000085 High Penetration Solar Deployment, the U. S. Department of Energy funded agreements with SMUD and Navigant Consulting, SunPower, GridPoint, the National Renewable Energy Laboratory, and the California Energy Commission for this pilot demonstration project. Funding was $5,962,409.00. Cost share of $500,000 was also provided by the California Energy Commission. The project has strategic implications for SMUD, other utilities and the PV and energy-storage industries in business and resource planning, technology deployment and asset management. These implications include: -At this point, no dominant business models have emerged and the industry is open for new ideas. -Demonstrated two business models for using distributed PV and energy storage, and brainstormed several dozen more, each with different pros and cons for SMUD, its customers and the industry. -Energy storage can be used to manage high penetrations of PV and mitigate potential issues such as reverse power flow, voltage control violations, power quality issues, increased wear and tear on utility equipment, and system wide power supply issues. - Smart meters are another tool utilities can use to manage high penetrations of PV. The necessary equipment and protocols exist, and the next step is to determine how to integrate the functionality with utility programs and what level of utility control is required. - Time-of-use rates for the residential customers who hosted energy storage systems did not cause a significant change in energy usage patterns. However, the rates we used were not optimized for PV and energy storage. Opportunities exist for utilities to develop new structures.

  13. Using a nonparametric PV model to forecast AC power output of PV plants

    OpenAIRE

    Almeida, Marcelo Pinho; Perpiñan Lamigueiro, Oscar; Narvarte Fernández, Luis

    2015-01-01

    In this paper, a methodology using a nonparametric model is used to forecast AC power output of PV plants using as inputs several forecasts of meteorological variables from a Numerical Weather Prediction (NWP) model and actual AC power measurements of PV plants. The methodology was built upon the R environment and uses Quantile Regression Forests as machine learning tool to forecast the AC power with a confidence interval. Real data from five PV plants was used to validate the methodology, an...

  14. Lithium Ion Batteries Ageing Analysis when used in a PV Power Plants

    DEFF Research Database (Denmark)

    Beltran, H.; Swierczynski, Maciej Jozef; Aparicio, N.

    2012-01-01

    This paper analyzes the integration of lithium ion (Li-ion) batteries into large scale grid-connected PV plants. It performs a systematic analysis on both the operation improvement obtained by a PV+ES power plant and the ageing experienced by the Li-ion batteries used as Energy Storage (ES) system...... when operating under different energy management strategies (EMS). In this paper, the PV+ES power plant structure is presented and the selection of Li-on batteries as ES system (ESS) is justified. Moreover, the simulation model used for studying the Li-ion battery ageing is explained and tested...

  15. Estimation of Maximum Allowable PV Connection to LV Residential Power Networks

    DEFF Research Database (Denmark)

    Demirok, Erhan; Sera, Dezso; Teodorescu, Remus

    2011-01-01

    transformer or using solar inverters with new grid support features. This study presents a methodology for the estimation of maximum PV hosting capacity including IEC 60076-7 based thermal model of distribution transformer. Certain part of a real distribution network of Braedstrup suburban area in Denmark...... is used in simulation as a case study model. Furthermore, varying solutions (utilizing thermally upgraded insulation paper in transformers, reactive power services from solar inverters, etc.) are implemented on the network under investigation to examine PV penetration level and finally key results learnt......Maximum photovoltaic (PV) hosting capacity of low voltage (LV) power networks is mainly restricted by either thermal limits of network components or grid voltage quality resulted from high penetration of distributed PV systems. This maximum hosting capacity may be lower than the available solar...

  16. Managing PV Power on Mars - MER Rovers

    Science.gov (United States)

    Stella, Paul M.; Chin, Keith; Wood, Eric; Herman, Jennifer; Ewell, Richard

    2009-01-01

    The MER Rovers have recently completed over 5 years of operation! This is a remarkable demonstration of the capabilities of PV power on the Martian surface. The extended mission required the development of an efficient process to predict the power available to the rovers on a day-to-day basis. The performance of the MER solar arrays is quite unlike that of any other Space array and perhaps more akin to Terrestrial PV operation, although even severe by that comparison. The impact of unpredictable factors, such as atmospheric conditions and dust accumulation (and removal) on the panels limits the accurate prediction of array power to short time spans. Based on the above, it is clear that long term power predictions are not sufficiently accurate to allow for detailed long term planning. Instead, the power assessment is essentially a daily activity, effectively resetting the boundary points for the overall predictive power model. A typical analysis begins with the importing of the telemetry from each rover's previous day's power subsystem activities. This includes the array power generated, battery state-of-charge, rover power loads, and rover orientation, all as functions of time. The predicted performance for that day is compared to the actual performance to identify the extent of any differences. The model is then corrected for these changes. Details of JPL's MER power analysis procedure are presented, including the description of steps needed to provide the final prediction for the mission planners. A dust cleaning event of the solar array is also highlighted to illustrate the impact of Martian weather on solar array performance

  17. 并网风光发电中混合储能系统容量优化配置%Capacity Optimization of Hybrid Energy Storage System in Grid-Connected Wind and PV Power Generation System

    Institute of Scientific and Technical Information of China (English)

    杨珺; 张建成; 桂勋

    2013-01-01

      提高并网风光发电系统的调度灵活性需要引入储能技术,而储能技术研究的首要关键技术问题就是储能系统的容量配置。利用蓄电池和超级电容器的互补特性,提出了一种以优化蓄电池工作状态为原则,以提高储能系统整体经济性为目标的能量管理策略。基于该能量管理策略分析了并网风光发电系统能量损失率和能量缺失率的计算流程,根据全生命周期费用理论,建立了储能装置的年均费用函数表达式,并建立了以该函数值最小为目标,以系统能量损失率及能量缺失率等运行指标为约束的储能容量优化配置模型。运用改进混沌优化算法对实例进行了计算,验证了该优化模型与算法的正确性和有效性。%  To improve scheduling flexibility of grid-connected Wind and PV power generation system, it is necessary for the system to apply energy storage technology, and the primary key technological problem to be researched is how to determine the capacity configuration of the energy storage system. Using complementary characteristics of the battery and the supercapacitor, an energy management strategy, in which the optimization of battery operating condition is taken as the principle and the improvement of overall economy of energy storage system as the objective, is proposed. Based on the proposed energy management storage, the energy loss rate of grid-connected wind and PV generation system and the calculation course of the rate are analyzed. According to the theory of life cycle cost, the expressions for annual average cost function of energy storage system is established;taking the minimization of this function value as the objective and the loss of produced power probability and the loss of power supply probability as constraints, an optimal configuration model for optimal configuration of the capacity of energy storage system is built. Case calculation is performed by

  18. Dynamic Modeling, Control and Simulation of a Wind and PV Hybrid System for Grid Connected Application Using MATLAB

    Directory of Open Access Journals (Sweden)

    D. Mahesh Naik

    2014-07-01

    Full Text Available This paper proposes a dynamic modeling and control strategy for a grid connected hybrid wind and photovoltaic (PV energy system inter-connected to electrical grid through power electronic interface. A gearless permanent magnet synchronous generator (PMSG is used to capture the maximum wind energy. The PV and wind systems are connected dc-side of the voltage source inverter through a boost converter individually and maintain a fixed dc output at dc link. A proper control scheme is required to operate power converters to match up the grid connection requirements. This study considered the performance of modeled hybrid system under different case scenarios. All simulation models are developed using MATLAB/Simulink.

  19. Final Report Report: Smart Grid Ready PV Inverters with Utility Communication

    Energy Technology Data Exchange (ETDEWEB)

    Seal, Brian [Electric Power Research Inst. (EPRI), Knovville, TN (United States); Huque, Aminul [Electric Power Research Inst. (EPRI), Knovville, TN (United States); Rogers, Lindsey [Electric Power Research Inst. (EPRI), Knovville, TN (United States); Key, Tom [Electric Power Research Inst. (EPRI), Knovville, TN (United States); Riley, Cameron [Electric Power Research Inst. (EPRI), Knovville, TN (United States); Li, Huijuan [Electric Power Research Inst. (EPRI), Knovville, TN (United States); York, Ben [Electric Power Research Inst. (EPRI), Knovville, TN (United States); Purcell, Chris [BPL Global, Inc., Canonsburg, PA (United States); Pacific, Oliver [Spirae, Inc., Fort Collins, CO (United States); Ropp, Michael [Northern Plains Power Technologies, Brookings, SD (United States); Tran, Teresa [DTE Energy, Detroit, MI (United States); Asgeirsson, Hawk [DTE Energy, Detroit, MI (United States); Woodard, Justin [National Grid, Warwick (United Kingdom); Steffel, Steve [Pepco Holdings, Inc., Washington, DC (United States)

    2016-03-30

    In 2011, EPRI began a four-year effort under the Department of Energy (DOE) SunShot Initiative Solar Energy Grid Integration Systems - Advanced Concepts (SEGIS-AC) to demonstrate smart grid ready inverters with utility communication. The objective of the project was to successfully implement and demonstrate effective utilization of inverters with grid support functionality to capture the full value of distributed photovoltaic (PV). The project leveraged ongoing investments and expanded PV inverter capabilities, to enable grid operators to better utilize these grid assets. Developing and implementing key elements of PV inverter grid support capabilities will increase the distribution system’s capacity for higher penetration levels of PV, while reducing the cost. The project team included EPRI, Yaskawa-Solectria Solar, Spirae, BPL Global, DTE Energy, National Grid, Pepco, EDD, NPPT and NREL. The project was divided into three phases: development, deployment, and demonstration. Within each phase, the key areas included: head-end communications for Distributed Energy Resources (DER) at the utility operations center; methods for coordinating DER with existing distribution equipment; back-end PV plant master controller; and inverters with smart-grid functionality. Four demonstration sites were chosen in three regions of the United States with different types of utility operating systems and implementations of utility-scale PV inverters. This report summarizes the project and findings from field demonstration at three utility sites.

  20. H6 Non-isolated Full Bridge Grid-connected PV Inverters With Low Leakage Currents

    Institute of Scientific and Technical Information of China (English)

    ZHANG Li; SUN Kai; FENG Lanlan; XING Yan; XU Ming

    2012-01-01

    Non-isolated inverter topologies have obtained more attentions in photovoltaic (PV) generation system since they are featured by higher efficiency and lower cost. In order to meet the safety requirement for the non-isolated grid-tied PV inverter, the common-mode leakage current is required to be carefully tackled due to the absence of the transformer. A H6 non-isolated full bridge PV grid-connected inverter is proposed to meet the limit for common-mode leakage current in grid-tied PV generation systems, as shown in Fig. 1.

  1. High Resolution PV Power Modeling for Distribution Circuit Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Norris, B. L.; Dise, J. H.

    2013-09-01

    NREL has contracted with Clean Power Research to provide 1-minute simulation datasets of PV systems located at three high penetration distribution feeders in the service territory of Southern California Edison (SCE): Porterville, Palmdale, and Fontana, California. The resulting PV simulations will be used to separately model the electrical circuits to determine the impacts of PV on circuit operations.

  2. Frequency Adaptive Repetitive Control of Grid-Tied Single-Phase PV Inverters

    DEFF Research Database (Denmark)

    Zhou, Keliang; Yang, Yongheng; Blaabjerg, Frede

    2015-01-01

    . This paper thus explores a frequency adaptive repetitive control strategy for grid converters, which employs fractional delay filters in order to adapt to the change of the grid frequency. Case studies with experimental results of a single-phase grid-connected PV inverter system are provided to verify...

  3. An algorithm for reduction of extracted power from photovoltaic strings in grid-tied photovoltaic power plants during voltage sags

    DEFF Research Database (Denmark)

    Tafti, Hossein Dehghani; Maswood, Ali Iftekhar; Pou, Josep

    2016-01-01

    Due to the high penetration of the installed distributed generation units in the power system, the injection of reactive power is required for the medium-scale and large-scale grid-connected photovoltaic power plants (PVPPs). Because of the current limitation of the grid-connected inverter......, the injected active power should be reduced during voltage sags. In order to obtain a constant dc-link voltage in a multi-string PVPP, the extracted power from PV strings should be equal to the injected power to the grid in all operating conditions (excluding power losses). Therefore, the extracted power of PV...

  4. Development of Flexible Active Power Control Strategies for Grid-Connected Photovoltaic Inverters by Modifying MPPT Algorithms

    DEFF Research Database (Denmark)

    Sangwongwanich, Ariya; Yang, Yongheng; Blaabjerg, Frede

    2017-01-01

    As the penetration level of grid-connected PV systems increases, more advanced control functionality is demanded. In order to ensure smooth and friendly grid integration as well as enable more PV installations, the power generated by PV systems needs to be flexible and capable of: 1) limiting...... strategies for grid-connected PV inverters by modifying maximum power point tracking algorithms, where the PV power is regulated by changing the operating point of the PV system. In this way, no extra equipment is needed, being a cost-effective solution. Experiments on a 3-kW grid-connected PV system have...... been performed, where the developed flexible active power control functionalities are achieved per demands....

  5. OPTIMIZATION AND SIZING OF A GRID-CONNECTED HYBRID PV-WIND ENERGY SYSTEM

    Directory of Open Access Journals (Sweden)

    C.S. SUPRIYA,

    2011-05-01

    Full Text Available Renewable energy resources such as solar and wind energies are highly advantageous compared to the conventional sources of power in many ways that they clean and available infinitely. But the onlydrawback is that their outputs depend upon the climatic conditions. Wind-Photovoltaic Hybrid System (WPHS utilization is becoming popular due to increasing energy costs and decreasing prices of turbines and Photo-Voltaic (PV panels. However, prior to construction of a renewable generation station, it is necessary to determine the optimum number of PV panels and wind turbines for minimal cost during continuity of generated energy to meet the desired consumption. The aim of this project is to determine the optimal design of a hybrid wind-solar power system for either autonomous or grid-linked applications. The proposed analysis employs quadratic programming techniques to minimize the cost while meeting the load requirements in a reliable manner. Using this procedure, optimum number of PV modules and wind turbines subject to minimum cost can be obtained with good accuracy. Results show that the hybrid systems have considerable reductions in carbon emission and cost of the system.

  6. Establishment of key grid-connected performance index system for integrated PV-ES system

    Science.gov (United States)

    Li, Q.; Yuan, X. D.; Qi, Q.; Liu, H. M.

    2016-08-01

    In order to further promote integrated optimization operation of distributed new energy/ energy storage/ active load, this paper studies the integrated photovoltaic-energy storage (PV-ES) system which is connected with the distribution network, and analyzes typical structure and configuration selection for integrated PV-ES generation system. By combining practical grid- connected characteristics requirements and technology standard specification of photovoltaic generation system, this paper takes full account of energy storage system, and then proposes several new grid-connected performance indexes such as paralleled current sharing characteristic, parallel response consistency, adjusting characteristic, virtual moment of inertia characteristic, on- grid/off-grid switch characteristic, and so on. A comprehensive and feasible grid-connected performance index system is then established to support grid-connected performance testing on integrated PV-ES system.

  7. Dynamic economic dispatch of power system with wind-PV power connected to grid%基于风光互补电力入网的电力系统动态经济调度

    Institute of Scientific and Technical Information of China (English)

    林虹江; 周步祥; 胡庆有; 杨昶宇; 冉伊; 詹长杰

    2014-01-01

    To solve the impact of uncertainty of hybrid wind and solar power connected to grid on power grid scheduling,an economic dispatch is studied in this paper.A penalty cost of environmental pollution is introduced into according to the emission characteristics of thermal power units,a penalty cost of spare capacity caused by intermittent electricity output volatility of hybrid wind and solar power system is introduced into also.Based on constraints such as unit ramp rate and balance between supply and demand of the system,a scheduling policy is given for connecting hybrid wind and solar power to grid,a dynamic economic dispatch model containing hybrid wind and solar power is established and the proposed model is solved by an improved particle swarm algorithm.Finally,IEEE-30 bus test system is taken as an example for simulation analysis,simulation results verify effectiveness and reasonableness of the proposed model and algorithms,the results show that connection to the grid of hybrid wind and solar power can restrain fluctuations of wind power output,and rate of hybrid wind and solar power connection to the grid has been increased on the basis of ensuring system reliability requirement.%为解决风光互补电力入网的不确定性给电网调度带来的影响,文章对其的经济调度问题进行研究.针对火电机组的排污特性引入了环境污染惩罚成本,针对风光电力输出功率的间歇波动性引入了备用容量惩罚成本,在考虑系统供需平衡与机组爬坡率等约束条件的基础上,给出了风光电力互补入网的调度策略,建立了含有风光互补电力的动态经济调度模型;应用一种改进的粒子群算法对所提模型进行求解.最后以IEEE-30节点测试系统为例进行仿真分析,仿真结果验证了所提模型的合理性及算法的有效性,同时也说明了风光互补电力入网能够平抑风电的出力波动,可以在保证系统可靠性的基础上,提高风光电力的并网率.

  8. How to Integrate Variable Power Source into a Power Grid

    Science.gov (United States)

    Asano, Hiroshi

    This paper discusses how to integrate variable power source such as wind power and photovoltaic generation into a power grid. The intermittent renewable generation is expected to penetrate for less carbon intensive power supply system, but it causes voltage control problem in the distribution system, and supply-demand imbalance problem in a whole power system. Cooperative control of customers' energy storage equipment such as water heater with storage tank for reducing inverse power flow from the roof-top PV system, the operation technique using a battery system and the solar radiation forecast for stabilizing output of variable generation, smart charging of plug-in hybrid electric vehicles for load frequency control (LFC), and other methods to integrate variable power source with improving social benefits are surveyed.

  9. Study on Battery Capacity for Grid-connection Power Planning with Forecasts in Clustered Photovoltaic Systems

    Science.gov (United States)

    Shimada, Takae; Kawasaki, Norihiro; Ueda, Yuzuru; Sugihara, Hiroyuki; Kurokawa, Kosuke

    This paper aims to clarify the battery capacity required by a residential area with densely grid-connected photovoltaic (PV) systems. This paper proposes a planning method of tomorrow's grid-connection power from/to the external electric power system by using demand power forecasting and insolation forecasting for PV power predictions, and defines a operation method of the electricity storage device to control the grid-connection power as planned. A residential area consisting of 389 houses consuming 2390 MWh/year of electricity with 2390kW PV systems is simulated based on measured data and actual forecasts. The simulation results show that 8.3MWh of battery capacity is required in the conditions of half-hour planning and 1% or less of planning error ratio and PV output limiting loss ratio. The results also show that existing technologies of forecasting reduce required battery capacity to 49%, and increase the allowable installing PV amount to 210%.

  10. Largest Grid-connected Solar Power Project in China

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ With the support of the National High-technology Development Program, scientists and engineers from the CAS Institute of Electrical Engineering recently completed a study on key technologies for megawatt-level building-integrated and grid-connected photovoltaic (PV)power generation. The project was checked and accepted by an expert panel on March 25.

  11. Power grid reliability and security

    Energy Technology Data Exchange (ETDEWEB)

    Bose, Anjan [Washington State Univ., Pullman, WA (United States); Venkatasubramanian, Vaithianathan [Washington State Univ., Pullman, WA (United States); Hauser, Carl [Washington State Univ., Pullman, WA (United States); Bakken, David [Washington State Univ., Pullman, WA (United States); Anderson, David [Washington State Univ., Pullman, WA (United States); Zhao, Chuanlin [Washington State Univ., Pullman, WA (United States); Liu, Dong [Washington State Univ., Pullman, WA (United States); Yang, Tao [Washington State Univ., Pullman, WA (United States); Meng, Ming [Washington State Univ., Pullman, WA (United States); Zhang, Lin [Washington State Univ., Pullman, WA (United States); Ning, Jiawei [Washington State Univ., Pullman, WA (United States); Tashman, Zaid [Washington State Univ., Pullman, WA (United States)

    2015-01-31

    This project has led to the development of a real-time simulation platform for electric power grids called Grid Simulator or GridSim for simulating the dynamic and information network interactions of large- scale power systems. The platform consists of physical models of power system components including synchronous generators, loads and control, which are simulated using a modified commercial power simulator namely Transient Stability Analysis Tool (TSAT) [1] together with data cleanup components, as well as an emulated substation level and wide-area power analysis components. The platform also includes realistic representations of communication network middleware that can emulate the real-time information flow back and forth between substations and control centers in wide-area power systems. The platform has been validated on a realistic 6000-bus model of the western American power system. The simulator GridSim developed in this project is the first of its kind in its ability to simulate real-time response of large-scale power grids, and serves as a cost effective real-time stability and control simulation platform for power industry.

  12. POWER GRID RELIABILITY AND SECURITY

    Energy Technology Data Exchange (ETDEWEB)

    Bose, Anjan; Venkatasubramanian, Vaithianathan; Hauser, Carl; Bakken, David; Anderson, David; Zhao, Chuanlin; Liu, Dong; Yang, Tao; Meng, Ming; Zhang, Lin; Ning, Jiawei; Tashman, Zaid

    2014-09-30

    This project has led to the development of a real-time simulation platform for electric power grids called Grid Simulator or GridSim for simulating the dynamic and information network interactions of large- scale power systems. The platform consists of physical models of power system components including synchronous generators, loads and control, which are simulated using a modified commercial power simulator namely Transient Stability Analysis Tool (TSAT) [1] together with data cleanup components, as well as an emulated substation level and wide-area power analysis components. The platform also includes realistic representations of communication network middleware that can emulate the real-time information flow back and forth between substations and control centers in wide-area power systems. The platform has been validated on a realistic 6000-bus model of the western American power system. The simulator GridSim developed in this project is the first of its kind in its ability to simulate real-time response of large-scale power grids, and serves as a cost effective real-time stability and control simulation platform for power industry.

  13. A Scenario-Based Approach for Energy Storage Capacity Determination in LV Grids with High PV Penetration

    DEFF Research Database (Denmark)

    Hashemi Toghroljerdi, Seyedmostafa; Østergaard, Jacob; Yang, Guangya

    2014-01-01

    In this paper a new method is proposed to determine the minimum energy storage required to be installed at different locations of a low voltage (LV) grid in order to prevent the overvoltage due to high residential photovoltaic (PV) penetration. The method is based on the voltage sensitivity...... with different occurrence probabilities without involving the time-series studies problems. The proposed method is capable of modeling output power of PV panels with different orientations as well as different electric vehicle (EV) charging patterns....

  14. Performance of a 34 kWp grid-connected PV system in Indonesia - A comparison of tropical and European PV systems

    NARCIS (Netherlands)

    Veldhuis, A.J.; Reinders, A.H.M.E.

    2014-01-01

    We analysed a monitored grid-connected PV system of 34 kWp in Indonesia to investigate the performance of PV systems in tropical climates. The PV system has been installed in Jayapura, the capital of the Province of Papua, Indonesia, by the beginning of 2012. Due to the aged gensets and frequent lac

  15. Methodology for the optimal design of tansformerless grid-connected PV interters

    DEFF Research Database (Denmark)

    Koutroulis, E.; Blaabjerg, Frede

    2012-01-01

    inverter, such that the PV inverter levelised cost of the generated electricity is minimised. The proposed method constitutes a systematic design process, which is capable to explore the impact of the PV inverter configuration on the trade-off between the PV inverter manufacturing cost and the power losses...

  16. A digital controlled PV-inverter with grid impedance estimation for ENS detection

    DEFF Research Database (Denmark)

    Asiminoaei, Lucian; Teodorescu, Remus; Blaabjerg, Frede

    2005-01-01

    of a PV-inverter with different advanced, robust control strategies and an embedded online technique to determine the utility grid impedance. By injecting an interharmonic current and measuring the voltage response it is possible to estimate the grid impedance at the fundamental frequency. The presented...... technique, which is implemented with the existing sensors and the CPU of the PV-inverter, provides a fast and low cost approach for online impedance measurement, which may be used for detection of islanding operation. Practical tests on an existing PV-inverter validate the control methods, the impedance...... measurement, and the islanding detection....

  17. Sandia and NJ TRANSIT Authority Developing Resilient Power Grid

    Energy Technology Data Exchange (ETDEWEB)

    Hanley, Charles J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Ellis, Abraham [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-11-01

    Through the memorandum of understanding between the Depratment of Energy (DOE), the New Jersey Transit Authority (NJ Transit), and the New Jersey Board of Public Utilities, Sandia National Labs is assisting NJ Transit in developing NJ TransitGrid: an electric microgrid that will include a large-scale gas-fired generation facility and distributed energy resources (photovoltaics [PV], energy storage, electric vehicles, combined heat and power [CHP]) to supply reliable power during storms or other times of significant power failure. The NJ TransitGrid was awarded $410M from the Department of Transportation to develop a first-of-its-kind electric microgrid capable of supplying highly-reliable power.

  18. A MPC Based ESS Control Method for PV Power Smoothing Applications

    DEFF Research Database (Denmark)

    Lei, Mingyu; Yang, Zilong; Wang, Yibo

    2017-01-01

    Random fluctuation in photovoltaic (PV) power plants is becoming a serious problem affecting the power quality and stability of the grid along with the increasing penetration of PVs. In order to solve this problem, by the adding of energy storage systems (ESS), a grid-connected microgrid system can....... At the same time, MPC can make a great contribution to the accuracy and timeliness of the control. Finally, experimental results from a grid-connected lab-scale microgrid system are presented to prove effectiveness and robustness of the proposed approach....

  19. Development and Testing of the Glenn Research Center Visitor's Center Grid-Tied Photovoltaic Power System

    Science.gov (United States)

    Eichenberg, Dennis J.

    2009-01-01

    The NASA Glenn Research Center (GRC) has developed, installed, and tested a 12 kW DC grid-tied photovoltaic (PV) power system at the GRC Visitor s Center. This system utilizes a unique ballast type roof mount for installing the photovoltaic panels on the roof of the Visitor s Center with no alterations or penetrations to the roof. The PV system has generated in excess of 15000 kWh since operation commenced in August 2008. The PV system is providing power to the GRC grid for use by all. Operation of the GRC Visitor s Center PV system has been completely trouble free. A grid-tied PV power system is connected directly to the utility distribution grid. Facility power can be obtained from the utility system as normal. The PV system is synchronized with the utility system to provide power for the facility, and excess power is provided to the utility. The project transfers space technology to terrestrial use via nontraditional partners. GRC personnel glean valuable experience with PV power systems that are directly applicable to various space power systems, and provides valuable space program test data. PV power systems help to reduce harmful emissions and reduce the Nation s dependence on fossil fuels. Power generated by the PV system reduces the GRC utility demand, and the surplus power aids the community. Present global energy concerns reinforce the need for the development of alternative energy systems. Modern PV panels are readily available, reliable, efficient, and economical with a life expectancy of at least 25 years. Modern electronics has been the enabling technology behind grid-tied power systems, making them safe, reliable, efficient, and economical with a life expectancy of at least 25 years. Based upon the success of the GRC Visitor s Center PV system, additional PV power system expansion at GRC is under consideration. The GRC Visitor s Center grid-tied PV power system was successfully designed and developed which served to validate the basic principles

  20. Control of a Multi-Functional Inverter for Grid Integration of PV and Battery Energy Storage System

    DEFF Research Database (Denmark)

    Mousazadeh, Seyyed Yousef; Firoozabadi, Mehdi Savaghebi; Beirami, A.

    2015-01-01

    This paper presents a multi-functional control of a DC/AC inverter for Power Quality compensation of nonlinear and unequal local loads and grid integration of hybrid photovoltaic (PV) and battery energy storage systems. Multi-layer neural network estimator and a DC/DC converter are used for maximum...... and nonlinear local loads. The simulation results which implemented in MATLAB/SIMULINK software verify the effectiveness of the system....

  1. Efficient Control of Active Transformers for Increasing the PV Hosting Capacity of LV Grids

    DEFF Research Database (Denmark)

    Hashemi Toghroljerdi, Seyedmostafa; Østergaard, Jacob; Degner, Thomas

    2016-01-01

    on decreasing the voltage rise along LV feeders, and the potential of active medium voltage to low voltage (MV/LV) transformers for overvoltage prevention has not been thoroughly investigated. This paper presents the application of active MV/LV transformers for increasing the PV hosting capacity of LV grids...... increase the PV hosting capacity of the grid, while eliminating the need for a complex and centralized controller. The voltages of specific locations or the grid state estimations provide adequate data for adjustments of the droop parameters. The simulations and field test results associated...

  2. Power supply to the public grid with power plant standard; Netzeinspeisesystem im Kraftwerksstandard

    Energy Technology Data Exchange (ETDEWEB)

    Seltmann, T.

    1999-01-01

    Siemens offers an new current inverter system which supplies solar power from large PV systems to the public grid in master-slave operation. The system is based on current inverter drives which have been used as serial products in industrial applications. [Deutsch] Siemens bietet jetzt ein Wechselrichtersystem an, das im Master-Slave-Betrieb den Solarstrom aus grossen PV-Anlagen ins Netz einspeist. Das System basiert auf Antriebsstromrichtern, die sich bereits als Serienprodukte in der industriellen Anwendung bewaehrt haben. (orig.)

  3. On-line grid impedance estimation based on harmonic injection for grid-connected PV inverter

    DEFF Research Database (Denmark)

    Ciobotaru, Mihai; Teodorescu, Remus; Blaabjerg, Frede

    2007-01-01

    The paper presents an on-line software method for impedance estimation of the energized impedances such as power system grid. The proposed method is based on producing a perturbation on the output of the power converter that is in the form of periodical injection of one or two voltage harmonic...... two different signal processing algorithms. The DFT technique is used for the single harmonic injection and the statistic technique is used for the double harmonic injection. The grid impedance estimation is used for compliance with the anti-islanding requirements of the German standard (VDE0126...... signals. The single harmonic injection uses a 600 Hz signal and the double harmonic injection uses a 400 Hz and 600 Hz signals, respectively. During the perturbation, the current response(s) at the same frequency as the injected signal(s) is/are measured. The value of the grid impedance is estimated using...

  4. Design of a Glenn Research Center Solar Field Grid-Tied Photovoltaic Power System

    Science.gov (United States)

    Eichenberg, Dennis J.

    2009-01-01

    The NASA Glenn Research Center (GRC) designed, developed, and installed, a 37.5 kW DC photovoltaic (PV) Solar Field in the GRC West Area in the 1970s for the purpose of testing PV panels for various space and terrestrial applications. The PV panels are arranged to provide a nominal 120 VDC. The GRC Solar Field has been extremely successful in meeting its mission. The PV panels and the supporting electrical systems are all near their end of life. GRC has designed a 72 kW DC grid-tied PV power system to replace the existing GRC West Area Solar Field. The 72 kW DC grid-tied PV power system will provide DC solar power for GRC PV testing applications, and provide AC facility power for all times that research power is not required. A grid-tied system is connected directly to the utility distribution grid. Facility power can be obtained from the utility system as normal. The PV system is synchronized with the utility system to provide power for the facility, and excess power is provided to the utility for use by all. The project transfers space technology to terrestrial use via nontraditional partners. GRC personnel glean valuable experience with PV power systems that are directly applicable to various space power systems, and provide valuable space program test data. PV power systems help to reduce harmful emissions and reduce the Nation s dependence on fossil fuels. Power generated by the PV system reduces the GRC utility demand, and the surplus power aids the community. Present global energy concerns reinforce the need for the development of alternative energy systems. Modern PV panels are readily available, reliable, efficient, and economical with a life expectancy of at least 25 years. Modern electronics has been the enabling technology behind grid-tied power systems, making them safe, reliable, efficient, and economical with a life expectancy of at least 25 years. The report concludes that the GRC West Area grid-tied PV power system design is viable for a reliable

  5. Digital power factor control and reactive power regulation for grid-connected photovoltaic inverter

    Energy Technology Data Exchange (ETDEWEB)

    Hassaine, L. [Power Electronics Systems Group, Universidad Carlos III de Madrid, Avda. de la Universidad 30, 28911 Leganes, Madrid (Spain); Ecole Nationale Polytechnique, Hassen Badi, El Harrach, Alger (Algeria); Olias, E.; Quintero, J. [Power Electronics Systems Group, Universidad Carlos III de Madrid, Avda. de la Universidad 30, 28911 Leganes, Madrid (Spain); Haddadi, M. [Ecole Nationale Polytechnique, Hassen Badi, El Harrach, Alger (Algeria)

    2009-01-15

    The overall efficiency of photovoltaic (PV) systems connected to the grid depends on the efficiency of direct current (DC) of the solar modules to alternate current (AC) inverter conversion. The requirements for inverter connection include: maximum power point, high efficiency, control power injected into the grid, high power factor and low total harmonic distortion of the currents injected into the grid. An approach to power factor control and reactive power regulation for PV systems connected to the grid using field programmable gate array (FPGA) is proposed. According to the grid demands; both the injected active and reactive powers are controlled. In this paper, a new digital control strategy for a single-phase inverter is carried out. This control strategy is based on the phase shift between the inverter output voltage and the grid voltage, and the digital sinusoidal pulse width modulation (DSPWM) patterns, in order to control the power factor for a wide range of the inverter output current and consequently the control and the regulation of the reactive power will be achieved. The advantage of the proposed control strategy is its implementation around simple digital circuits. In this work, a simulation study of this strategy has been realized using Matlab/Simulink and PSIM. In order to validate its performance, this control has been implemented in a FPGA. Experimental tests have been carried out demonstrating the viability of this control in order to control the power factor and the injected power into the grid. (author)

  6. Predicting Failures in Power Grids

    CERN Document Server

    Chertkov, Michael; Stepanov, Mikhail G

    2010-01-01

    Here we develop an approach to predict power grid weak points, and specifically to efficiently identify the most probable failure modes in load distribution for a given power network. This approach is applied to two examples: Guam's power system and also the IEEE RTS-96 system, both modeled within the static Direct Current power flow model. Our algorithm is a power network adaption of the worst configuration heuristics, originally developed to study low probability events in physics and failures in error-correction. One finding is that, if the normal operational mode of the grid is sufficiently healthy, the failure modes, also called instantons, are sufficiently sparse, i.e. the failures are caused by load fluctuations at only a few buses. The technique is useful for discovering weak links which are saturated at the instantons. It can also identify overutilized and underutilized generators, thus providing predictive capability for improving the reliability of any power network.

  7. DISTRIBUTED GRID-CONNECTED PHOTOVOLTAIC POWER SYSTEM EMISSION OFFSET ASSESSMENT: STATISTICAL TEST OF SIMULATED- AND MEASURED-BASED DATA

    Science.gov (United States)

    This study assessed the pollutant emission offset potential of distributed grid-connected photovoltaic (PV) power systems. Computer-simulated performance results were utilized for 211 PV systems located across the U.S. The PV systems' monthly electrical energy outputs were based ...

  8. Maximum Power Point Tracking and Reactive Power Control of Single Stage Grid Connected Photovoltaic System

    Directory of Open Access Journals (Sweden)

    Y. Hoseynpoor

    2011-12-01

    Full Text Available Single-stage grid-connected Photovoltaic (PV systems have advantages such as simple topology, high efficiency, etc. However, since all the control objectives such as the maximum power point tracking (with the utility voltage, and harmonics reduction for output current need to be considered simultaneously, the complexity of the control scheme is much increased. In this paper a new type of grid connected photovoltaic (PV system with Maximum Power Point Tracking (MPPT and reactive power simultaneous control system is presented. System has two controlling loops to obtain the maximum power from the PV array and also has reactive power control (RPC. In order to decrease the complexity, cost and the number of converters, a singlestage PV system is applied. Using RPC and MPPT controllers, reference current is calculated and the current with low THD (<5% is injected to grid through Adaptive Predictive Current Control (APCC and current Controlled Voltage Source Inverter (CCVSI. The operation of the system is classified in to two day and night modes. In day mode MPPT and RPC control is accomplished and in night mode RPC control is accomplished like STATCOM operation. Reactive power control is continuously performed correctly with appropriate speed in two inductive and capacitive modes in both day and night modes. Thus, System Utilization Factor (SUF increases to 100% which is just 20% for common PV systems. Mathematical modeling of the system and the results of simulations in MATLAB/SIMULINK software are presented to investigate the correctness of the results.

  9. Interline Photovoltaic (I-PV) power system - A novel concept of power flow control and management

    OpenAIRE

    2011-01-01

    This paper presents a new system configuration for a large-scale Photovoltaic (PV) power system with multi-line transmission/distribution networks. A PV power plant is reconfigured in a way that two adjacent power system networks/ feeders can be interconnected. The inverter modules in a PV power plant are configured such that the system is represented as a back to back inverter connected multi-line system, called as Interline-PV (I-PV) system. The proposed I-PV system then can be controlled a...

  10. Integration of Hybrid PV/Wind Generation System Using Fuzzy MPPT in Grid Connected System for Remote Area

    Directory of Open Access Journals (Sweden)

    Soedibyo

    2016-01-01

    Full Text Available Photovoltaic and wind are renewable energy resources that widely used and grow rapidly in fulfilling electricity demand. Powers from both technologies depend on sunlight intensity and wind speed. For small scale power generation, DC voltage from both technologies is low and requires step-up converter to raise DC voltage ratio before converted into AC voltage. To optimize this system, step-up converter must have high ratio and efficiency to a distance of wide voltage input. This paper proposed an operation simulation and arrangement of DC-DC converter along with DC-AC from hybrid source PV-Wind which integrated to grid utilities without using storage device. High Gain Integrated Cascade Boost (HGICB is DC-DC converter that has quadratic voltage ratio and used in this research. Then DC link connected to Voltage Source Inverter (VSI which interconnected with utility grid and controlled by current control method. The total installed capacity of hybrid source is 4.4 kW. Wind turbine uses PMSG along with full bridge rectifier. To maximize and stabilize the generated power, MPPT fuzzy is used. Result from the simulation shows that converter capable to maintain maximum power whether from PV and wind turbine which canalized to utility grid in various irradiation condition, wind speed, and grid load alteration.

  11. Droop Control of Solar PV, Grid and Critical Load using Suppressing DC Current Injection Technique without Battery Storage

    Science.gov (United States)

    Dama Mr., Jayachandra; (Mrs. , Lini Mathew, Dr.; Srikanth Mr., G.

    2017-08-01

    This paper presents design of a sustainable solar Photo voltaic system for an Indian cities based residential/community house, integrated with grid, supporting it as supplementary sources, to meet energy demand of domestic loads. The role of renewable energy sources in Distributed Generation (DG) is increasingly being recognized as a supplement and an alternative to large conventional central power supply. Though centralized economic system that solely depends on cities is hampered due to energy deficiency, the use of solar energy in cities is never been tried widely due to technical inconvenience and high installation cost. To mitigate these problems, this paper proposes an optimized design of grid-tied PV system without storage which is suitable for Indian origin as it requires less installallation cost and supplies residential loads when the grid power is unavailable. The energy requirement is mainly fulfilled from PV energy module for critical load of a city located residential house and supplemented by grid/DG for base and peak load. The system has been developed for maximum daily household demand of 50kWp and can be scaled to any higher value as per requirement of individual/community building ranging from 50kWp to 60kWp as per the requirement. A simplified control system model has been developed to optimize and control flow of power from these sources. The simulation work, using MATLAB Simulink software for proposed energy management, has resulted in an optimal yield leading efficient power flow control of proposed system.

  12. Prospects for investment in large-scale, grid-connected solar power in Africa

    DEFF Research Database (Denmark)

    Hansen, Ulrich Elmer; Nygaard, Ivan; Pedersen, Mathilde Brix

    Solar power in Africa is on its way to becoming a market-based commodity, thus escaping the niche for individual electricity supply that is mainly supported by international donor organisations. Significant reductions in the cost of photovoltaic (PV) panels and a 400 percent increase in oil prices......-scale investments in grid-connected solar power plants and local assembly facilities for PV panels, have exceeded even optimistic scenarios. Finally, therefore, there seem to be bright prospects for investment in large-scale grid-connected solar power in Africa....... since the 1990s have changed the competiveness of solar PV in all markets, ranging from individual households via institutions to mini-grids and grid-connected installations. In volume and investment, the market for large-scale grid-connected solar power plants is by far the most important...

  13. Single Phase PV Grid-Connected in Smart Household Energy System with Anticipation on Fault Conditions

    Directory of Open Access Journals (Sweden)

    Feri Yusivar

    2014-02-01

    Full Text Available This paper proposes an algorithm of Smart household energy systems to anticipate fault conditions in power system grid. Single phase PV grid-connected in smart household energy system is a smart system that determines electrical supply conditions to the load in residential electrical system. The smart system is consisted of two voltage source, conventional electricity system from national electricity provider as preferred source and photovoltaic as the alternative source. In smart system, fault conditions can be anticipated by selecting the appropriate voltage sources to supply the load. The condition of smart system can be described in power flow regulation to the load by detection and identification of amplitude, phase angle, and frequency of the voltage source compared to the system reference. The system mechanism is based on detection of voltage source using static transfer switch (STS with phase locked loop (PLL as voltage detection algorithm which output is used to determine decision logic algorithm for switching conditions. The results show that conditions of smart power system flow can be obtained based on voltage source selection in decision logic when fault condition occurs.

  14. Structural vulnerability assessment of electric power grids

    NARCIS (Netherlands)

    Koç, Y.; Warnier, M.; Kooij, R.E.; Brazier, F.

    2014-01-01

    Cascading failures are the typical reasons of blackouts in power grids. The grid topology plays an important role in determining the dynamics of cascading failures in power grids. Measures for vulnerability analysis are crucial to assure a higher level of robustness of power grids. Metrics from Comp

  15. Commercialization of PV-powered pumping systems for use in utility PV service programs. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    The project described in this report was a commercialization effort focused on cost-effective remote water pumping systems for use in utility-based photovoltaic (PV) service programs. The project combined a commercialization strategy tailored specifically for electric utilities with the development of a PV-powered pumping system that operates conventional ac pumps rather than relying on the more expensive and less reliable PV pumps on the market. By combining these two attributes, a project goal was established of creating sustained utility purchases of 250 PV-powered water pumping systems per year. The results of each of these tasks are presented in two parts contained in this Final Summary Report. The first part summarizes the results of the Photovoltaic Services Network (PSN) as a new business venture, while the second part summarizes the results of the Golden Photon system installations. Specifically, results and photographs from each of the system installations are presented in this latter part.

  16. National survey report on PV power applications in Switzerland 2006

    Energy Technology Data Exchange (ETDEWEB)

    Huesser, P. [Nova Energie GmbH, Aarau (Switzerland); Hostettler, T. [Ingenieurbuero Hostettler, Berne (Switzerland)

    2007-07-01

    This annual report was published by the Swiss Federal Office of Energy (SFOE) as part of the International Energy Agency's work on the exchange and dissemination of information on photovoltaic power systems (PVPS). The political situation in Switzerland with regard to the promotion of photovoltaics (PV) and new legislation in the energy area is discussed. The report provides information on installed PV power, costs and prices and the Swiss PV industry. Examples of PV applications are presented and data on the cumulative installed PV power in various application sectors is presented and discussed. Highlights, major projects and various demonstration and field-test programmes are dealt with, as are public budgets for market stimulation. Figures on the development, production and prices of PV cells and modules are presented. Swiss balance-of-system products are reviewed, as are PV-related services and the value of the Swiss PV business. A review of non-technical factors and new initiatives completes the report.

  17. Residential photovoltaic power conditioning technology for grid connected applications

    Science.gov (United States)

    Key, T. S.; Klein, J. W.

    Major advances in photovoltaic (PV) Power Conditioning (PC) with respect to performance and low-cost potential have been made. Solutions have been obtained to interface and control problems related to adapting available inverter designs to the grid-connected, residential photovoltaic experiments. A description is presented to contributing research and development activities. Attention is given to aspects of residential systems experience, conceptual design studies, questions of optimum topology development, and promising advanced designs for residential PV provided by development efforts of the private sector.

  18. Transdisciplinary electric power grid science

    CERN Document Server

    Brummitt, Charles D; Dobson, Ian; Moore, Cristopher; D'Souza, Raissa M

    2013-01-01

    The 20th-century engineering feat that most improved the quality of human life, the electric power system, now faces discipline-spanning challenges that threaten that distinction. So multilayered and complex that they resemble ecosystems, power grids face risks from their interdependent cyber, physical, social and economic layers. Only with a holistic understanding of the dynamics of electricity infrastructure and human operators, automatic controls, electricity markets, weather, climate and policy can we fortify worldwide access to electricity.

  19. Transdisciplinary electric power grid science

    OpenAIRE

    Brummitt, Charles D.; Hines, Paul D. H.; Dobson, Ian; Moore, Cristopher; D'Souza, Raissa M.

    2013-01-01

    The 20th-century engineering feat that most improved the quality of human life, the electric power system, now faces discipline-spanning challenges that threaten that distinction. So multilayered and complex that they resemble ecosystems, power grids face risks from their interdependent cyber, physical, social and economic layers. Only with a holistic understanding of the dynamics of electricity infrastructure and human operators, automatic controls, electricity markets, weather, climate and ...

  20. Apolication of Hysteresis SVPWM Control in PV Grid-connected Inverter%滞环SVPWM控制在光伏并网逆变器中的应用

    Institute of Scientific and Technical Information of China (English)

    李畸勇; 龚仁喜; 韦海燕

    2011-01-01

    由于光伏并网发电系统有许多优点,这里在两级式光伏并网发电系统的基础上,分析了滞环空间矢量脉宽调制电流控制原理,并将其应用于光伏并网发电系统的逆变器控制,以此来提高光伏发电并网控制的动态响应和并网电流质量.建立了系统仿真模型和相应的实验平台,仿真和实验结果表明了该控制方法的有效性,能较好地满足光伏并网控制的要求.%Because photovoltaic (PV) grid-connected power system has many advantages,based on two state PV gridconnected power system, the hysteresis SVPWM current control theory is analyzed and proposed to apply in the inverter control of PV grid-connected power system. In order to improve the dynamic response of grid-connected control and grid-connected current quality. The system simulation model and the corresponding experimental platform are established ,simulation and experiment are carried out at the same time. The results show that the control method can satisfy the requirement of PV grid-connected power system.

  1. A control system for improved battery utilization in a PV-powered peak-shaving system

    Energy Technology Data Exchange (ETDEWEB)

    Palomino, E [Salt River Project, Phoenix, AZ (United States); Stevens, J. [Sandia National Labs., Albuquerque, NM (United States); Wiles, J. [New Mexico State Univ., Las Cruces, NM (United States). Southwest Technology Development Inst.

    1996-08-01

    Photovoltaic (PV) power systems offer the prospect of allowing a utility company to meet part of the daily peak system load using a renewable resource. Unfortunately, some utilities have peak system- load periods that do not match the peak production hours of a PV system. Adding a battery energy storage system to a grid-connected PV power system will allow dispatching the stored solar energy to the grid at the desired times. Batteries, however, pose system limitations in terms of energy efficiency, maintenance, and cycle life. A new control system has been developed, based on available PV equipment and a data acquisition system, that seeks to minimize the limitations imposed by the battery system while maximizing the use of PV energy. Maintenance requirements for the flooded batteries are reduced, cycle life is maximized, and the battery is operated over an efficient range of states of charge. This paper presents design details and initial performance results on one of the first installed control systems of this type.

  2. A GRID CONNECTED PV SYSTEM INTEGRATED THROUGH MULTILEVEL MODULAR CASCADED H-BRIDGE INVERTER BY USING FUZZY LOGIC CONTROLLER

    OpenAIRE

    2016-01-01

    This paper presents a modular cascaded H-bridge multilevel photovoltaic (PV) inverter for three-phase grid-connected applications. The modular cascaded multilevel topology helps to improve the efficiency and flexibility of PV systems. The main abstruse is the harmonization of the DG to the utility grid. Generally current regulated PWM voltage-source inverters (VSI) are used for synchronizing the utility grid with DG source in order to meet the following objectives: 1) To ensure grid stability...

  3. Power Electronic System for Multi-MW PV sites

    DEFF Research Database (Denmark)

    Paasch, Kasper

    The work presented in this thesis addresses the optimization potential of large PV power plants with respect to energy production during periods of moving clouds. Presently the number and size of utility scale Photo Voltaic (PV) power plants in the megawatt range is increasing and the market...... of energy is in the range ... for field use, is battery operated and has been applied for the characterization of a solar panel over a period of 6 months at the ESTER Outdoor PV monitoring station in Rome, Italy....

  4. Performance evaluation of 10 MW grid connected solar photovoltaic power plant in India

    OpenAIRE

    2015-01-01

    The growing energy demand in developing nations has triggered the issue of energy security. This has made essential to utilize the untapped potential of renewable resources. Grid connected PV systems have become the best alternatives in renewable energy at large scale. Performance analysis of these grid connected plants could help in designing, operating and maintenance of new grid connected systems. A 10 MW photovoltaic grid connected power plant commissioned at Ramagundam is one of the larg...

  5. Potential and cost-effectiveness of off-grid PV systems in Indonesia - An evaluation on a provincial level

    NARCIS (Netherlands)

    Veldhuis, A.J.; Reinders, A.H.M.E.

    2014-01-01

    In this study we estimate the potential of off-grid PV systems in Indonesia at a provincial level as a follow-up of a study on the potential of grid-connected PV systems in Indonesia which we executed in 2012 [1]. For this study we use an adapted methodology leading to cumulative numbers for the nom

  6. A New Method of On-line Grid Impedance Estimation for PV Inverter

    DEFF Research Database (Denmark)

    Teodorescu, Remus; Asiminoaei, Lucian; Blaabjerg, Frede

    2004-01-01

    for on-line measuring the grid impedance is presented. The presented method requires no extra hardware being accommodated by typical PV inverters, sensors and CPU, to provide a fast and low cost approach of on-line impedance measurement. By injecting a non-characteristic harmonic current and measuring...

  7. Is grid parity an indicator for PV market expansion in the Netherlands?

    Energy Technology Data Exchange (ETDEWEB)

    Olson, C.L.; Luxembourg, S.L.; Sinke, W.C. [ECN Solar Energy, P.O. Box 1, 1755 ZG Petten (Netherlands); Van Sark, W.G.J.H.M. [Stichting Monitoring Zonnestroom, Korte Elisabethstraat 6, 3511 JG Utrecht (Netherlands)

    2013-10-15

    Grid parity occurred in the residential sector in the Netherlands in the period 2011-2012, because the levelized cost of electricity (LCoE) for a typical residential PV system (0.6-5 kWp) was well below 0.2 euro/kWh, for interest rates between 3 and 8%, while the retail electricity price was 0.23 euro/kWh, propelling a significant increase in installed PV capacity in the residential sector. It is revealing to discuss the constellation of factors that have led to grid parity in the Netherlands, and whether they will lead to continued market expansion. These factors include those relevant to the industry (i.e. the cost learning curve and the overcapacity) as well as those specific to the Netherlands (various policy incentives, net-metering, as well as large-scale purchasing actions). 'Grid parity' may not reflect the growth perspectives for the industry because it gives no information on the adequacy of the PV system prices to impel market expansion, or on the complexity and controls on grid electricity pricing, which depend only to a small degree on generation costs. Low PV system prices were accompanied by an increase in installations but 'unhealthy' prices will not necessarily mean continued market expansion. The continuation of the cost learning curve to drive down PV prices depends to a certain degree on R and D budgets, which are under severe pressure in the current environment. Grid parity in the residential sector has been accompanied by a surge of installations, however this trend is not being paralleled by the non-residential sectors.

  8. Grid-connected PV systems - How and where they fit

    Science.gov (United States)

    Thomas, M. G.; Jones, G. J.

    The use of grid-connected photovoltaic systems requires substantial improvements in system economics. By integrating anticipated improvements in economics with consumer needs and perceptions, the various potential applications have been order-ranked. Third-party ownership of large systems appears to have the largest potential, residential has a modest potential, and the intermediate dedicated-load application potential appears to be small.

  9. A Single-Phase Voltage-Controlled Grid-Connected Photovoltaic System With Power Quality Conditioner Functionality

    DEFF Research Database (Denmark)

    Kerekes, Tamas; Liserre, Marco; Mastromauro, R. A.

    2009-01-01

    Future ancillary services provided by photovoltaic (PV) systems could facilitate their penetration in power systems. Also low power PV systems can be designed to improve the power quality. This paper presents a single-phase photovoltaic system that provides grid voltage support and compensation...... of harmonic distortion at the point of common coupling (PCC) thanks to a repetitive controller. The power provided by the PV panels is controlled by a Maximum Power Point Tracking (MPPT) algorithm based on the incremental conductance method specifically modified to control the phase of the PV inverter voltage...

  10. Monitoring and remote failure detection of grid-connected PV systems based on satellite observations

    Energy Technology Data Exchange (ETDEWEB)

    Drews, A.; Lorenz, E.; Betcke, J.; Heinemann, D. [Oldenburg University, Institute of Physics, Carl-von-Ossietzky-Str. 9-11, 26129 Oldenburg (Germany); de Keizer, A.C.; van Sark, W.G.J.H.M. [University of Utrecht, Copernicus Institute, Department of Science, Technology, and Society, Heidelberglaan 2, 3584 CH Utrecht (Netherlands); Beyer, H.G. [University of Applied Sciences Magdeburg-Stendal (FH), Institute of Electrical Engineering, Breitscheidstr. 2, 39114 Magdeburg (Germany); Heydenreich, W.; Wiemken, E. [Fraunhofer Institute for Solar Energy Systems, Heidenhofstr. 2, 79110 Freiburg (Germany); Stettler, S.; Toggweiler, P. [Enecolo AG, Lindhofstr. 52, 8617 Moenchaltorf (Switzerland); Bofinger, S.; Schneider, M.; Heilscher, G. [Meteocontrol GmbH, Spicherer Strasse 48, 86157 Augsburg (Germany)

    2007-04-15

    Small grid-connected photovoltaic systems up to 5 kW{sub p} are often not monitored because advanced surveillance systems are not economical. Hence, some system failures which lead to partial energy losses stay unnoticed for a long time. Even a failure that results in a larger energy deficit can be difficult to detect by PV laymen due to the fluctuating energy yields. Within the EU project PVSAT-2, a fully automated performance check has been developed to assure maximum energy yields and to optimize system maintenance for small grid-connected PV systems. The aim is the early detection of system malfunctions and changing operating conditions to prevent energy and subsequent financial losses for the operator. The developed procedure is based on satellite-derived solar irradiance information that replaces on-site measurements. In conjunction with a simulation model the expected energy yield of a PV system is calculated. In case of the occurrence of a defined difference between the simulated and actual energy yield, an automated failure detection routine searches for the most probable failure sources and notifies the operator. This paper describes the individual components of the developed procedure - the satellite-derived irradiance, the used PV simulation model, and the principles of the automated failure detection routine. Moreover, it presents results of an 8-months test phase with 100 PV systems in three European countries. (author)

  11. On-grid PV implementation program. Phase I report, August 1994--January 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-11-29

    Southern California Edison Company (Edison) is finalizing a Cooperative Agreement with the U.S. Department of Energy (DOE) to develop high value On-Grid applications for electricity from Photovoltaics (PV). Edison`s efforts are the result of Edison`s long-standing commitment to the pursuit of Renewable Energy. Edison has been a world leader in the development and use of PV. As the technology becomes more commercial, Edison has been actively seeking more applications for PV. After strenuous effort, Edison has now received approval to offer off-grid PV packages within its service territory. In addition, Edison has been very interested in finding high-value on-grid PV applications that may have the potential to become cost effective as PV applications increase and prices decline. Such high-value applications at Edison and other utilities will accelerate the price reductions, which in turn will increase the number of cost-effective applications, driving towards a market competitive with traditional sources of energy. Edison`s efforts build upon the work done by Pacific Gas & Electric (PG&E) at their Kerman substation, but goes much further than that effort. Edison submitted its original proposal to the DOE on June 30, 1993. A revised proposal was submitted on February 1, 1994, in response to a letter from the DOE`s Director of Solar Energy, Robert H. Annan. In a letter dated March 30, 1994, from Paul K. Kearns, Head of Contracting Activity for the DOE`s Golden Field Office, the DOE conditionally approved certain pre-award contract costs. The Cooperative Agreement with DOE was executed on August 16, 1994.

  12. Ancillary services provided by PV power plants

    Directory of Open Access Journals (Sweden)

    Antonio PIERNO

    2016-07-01

    Full Text Available Renewable energy sources are widely utilized in distributed generation systems, and, recently, they are also considered for providing ancillary services. The paper is focused on PV plants, a survey of the most interesting papers published in the literature in the last decade is reported and the main characteristics of the technical proposals, with their advantages and limits, are evidenced. The results are schematically shown in a table that immediately gives the opportunity to be aware of what was already done, representing a reference tool.

  13. Common mode voltage in case of transformerless PV inverters connected to the grid

    DEFF Research Database (Denmark)

    Kerekes, Tamas; Teodorescu, Remus; Liserre, Marco

    2008-01-01

    For safety reasons grid connected PV systems include galvanic isolation. In case of transformerless inverters, the leakage ground current through the parasitic capacitance of the PV panels, can reach very high values. A common-mode model based on analytical approach is introduced, used to predict...... the common-mode behavior, at frequencies lower than 50kHz, of the selected topologies and to explain the influence of system imbalance on the leakage current. It will be demonstrated that the neutral inductance has a crucial influence on the leakage current. Finally experimental results will be shown...

  14. Multivariate Statistics and Supervised Learning for Predictive Detection of Unintentional Islanding in Grid-Tied Solar PV Systems

    Directory of Open Access Journals (Sweden)

    Shashank Vyas

    2016-01-01

    Full Text Available Integration of solar photovoltaic (PV generation with power distribution networks leads to many operational challenges and complexities. Unintentional islanding is one of them which is of rising concern given the steady increase in grid-connected PV power. This paper builds up on an exploratory study of unintentional islanding on a modeled radial feeder having large PV penetration. Dynamic simulations, also run in real time, resulted in exploration of unique potential causes of creation of accidental islands. The resulting voltage and current data underwent dimensionality reduction using principal component analysis (PCA which formed the basis for the application of Q statistic control charts for detecting the anomalous currents that could island the system. For reducing the false alarm rate of anomaly detection, Kullback-Leibler (K-L divergence was applied on the principal component projections which concluded that Q statistic based approach alone is not reliable for detection of the symptoms liable to cause unintentional islanding. The obtained data was labeled and a K-nearest neighbor (K-NN binomial classifier was then trained for identification and classification of potential islanding precursors from other power system transients. The three-phase short-circuit fault case was successfully identified as statistically different from islanding symptoms.

  15. Impact of Rural Grid-Connected Photovoltaic Generation Systems on Power Quality

    Directory of Open Access Journals (Sweden)

    Rita Pinto

    2016-09-01

    Full Text Available Photovoltaic (PV generation systems have been increasingly used to generate electricity from renewable sources, attracting a growing interest. Recently, grid connected PV micro-generation facilities in individual homes have increased due to governmental policies as well as greater attention by industry. As low voltage (LV distribution systems were built to make energy flow in one direction, the power feed-in of PV generation in rural low-voltage grids can influence power quality (PQ as well as facility operation and reliability. This paper presents results on PQ analysis of a real PV generation facility connected to a rural low-voltage grid. Voltage fluctuations and voltage harmonic contents were observed. Statistical analysis shows a negative impact on PQ produced by this PV facility and also that only a small fraction of the energy available during a sunny day is converted, provoking losses of revenue and forcing the converter to work in an undesirable operating mode. We discuss the disturbances imposed upon the grid and their outcome regarding technical and economic viability of the PV system, as well as possible solutions. A low-voltage grid strengthening has been suggested and implemented. After that a new PQ analysis shows an improvement in the impact upon PQ, making this facility economically viable.

  16. Design and Implementation of A PV Powered Tri-Cycle

    Directory of Open Access Journals (Sweden)

    Soumya Das

    2016-04-01

    Full Text Available Solar PV technology is one of the first among the various renewable energy technologies that have been adopted and accepted universally in order to meet the basic needs of generation of electricity. The objective of this paper is to propose a tri-cycle that utilises the application of stand-alone photovoltaic (PV system. A preliminary design and construction of a solar tri-cycle has been performed by evaluating and estimating the required panel size, battery capacity and motor power. Calculation in this paper exhibit that the solar power alone will be sufficient to operate a tri-cycle from one place to another.

  17. A comparison of design features of 80 pv-powered products

    NARCIS (Netherlands)

    Apostolou, G.; Reinders, A.H.M.E.

    2012-01-01

    In this paper 80 commercially available PV products have been analysed. The data set comprises 46 low power PV products in the range of 0 to 17 Wp and 34 PV products with a power of 17 Wp up to 27 kWp. The goal of our study is to investigate and evaluate features of PV products that are available on

  18. Public Response to Residential Grid-Tied PV Systems in Colorado: A Qualitative Market Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Farhar, Barbara C. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Buhrmann, Jan [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    1998-07-01

    The early adopters of residential grid-tied photovoltaics (PV) have complex motivations to pay today's costs, including altruistic, environmental, and financial reasons. Focused interviews were conducted with a self-selected purposive sample interested in purchasing 2-kW or 3-kW PV systems with an installed cost of $8,000 to $12,000. The sample tended to be men or married couples ranging in age from their early thirties to their mid-eighties; professionals, managers, or small business owners; relatively financially secure, with experience with energy efficiency and renewable energy. Product attributes they preferred were net metering, warranties, guarantees, utility financing, maintenance, an option to own or lease, a battery option, and an aesthetically pleasing system. Potential PV customers needed more information before making a purchase decision.

  19. Application Note: Power Grid Modeling With Xyce.

    Energy Technology Data Exchange (ETDEWEB)

    Sholander, Peter E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-06-01

    This application note describes how to model steady-state power flows and transient events in electric power grids with the SPICE-compatible Xyce TM Parallel Electronic Simulator developed at Sandia National Labs. This application notes provides a brief tutorial on the basic devices (branches, bus shunts, transformers and generators) found in power grids. The focus is on the features supported and assumptions made by the Xyce models for power grid elements. It then provides a detailed explanation, including working Xyce netlists, for simulating some simple power grid examples such as the IEEE 14-bus test case.

  20. An Optimized Combination of a Large Grid Connected PV System along with Battery Cells and a Diesel Generator

    OpenAIRE

    2016-01-01

    Environmental, economical and technical benefits of photovoltaic (PV) systems make them to be used in many countries. The main characteristic of PV systems is the fluctuations of their output power. Hence, high penetration of PV systems into electric network could be detrimental to overall system performance. Furthermore, the fluctuations in the output power of PV systems make it difficult to predict their output, and to consider them in generation planning of the units. The main objective of...

  1. Stochastic Power Grid Analysis Considering Process Variations

    CERN Document Server

    Ghanta, Praveen; Panda, Rajendran; Wang, Janet

    2011-01-01

    In this paper, we investigate the impact of interconnect and device process variations on voltage fluctuations in power grids. We consider random variations in the power grid's electrical parameters as spatial stochastic processes and propose a new and efficient method to compute the stochastic voltage response of the power grid. Our approach provides an explicit analytical representation of the stochastic voltage response using orthogonal polynomials in a Hilbert space. The approach has been implemented in a prototype software called OPERA (Orthogonal Polynomial Expansions for Response Analysis). Use of OPERA on industrial power grids demonstrated speed-ups of up to two orders of magnitude. The results also show a significant variation of about $\\pm$ 35% in the nominal voltage drops at various nodes of the power grids and demonstrate the need for variation-aware power grid analysis.

  2. Marketing residential grid-connected PV systems using a balanced scorecard as a marketing tool

    Energy Technology Data Exchange (ETDEWEB)

    Bach, N. [University of Giessen (Germany). Dept. of Organisation and Management; Calais, P. [Murdoch University, Perth (Australia). School of Environmental Science; Calais, M. [Curtin University, Perth (Australia). Centre for Renewable Systems Technology

    2001-03-01

    A strategic analysis of the electricity market in Western Australia yields a market potential for renewable energy in Western Australia. However, from a purely financial viewpoint the installation of grid-connected pv-systems still is not economically viable. In this paper a balanced scorecard (BSC) is developed to capture and visualize other than financial benefits. Therefore, the BSC can be used as a marketing tool to communicate the benefits of a privately owned GCPV system to potential customers. (author)

  3. Stochastic optimization in the power grid

    NARCIS (Netherlands)

    Leenman, T.S.

    2012-01-01

    In this thesis steps are described to determine the locations of new wind mills which minimize energy loss on the Dutch High Voltage power grid. A vindication of the used power grid model is provided; the simulation procedure for stochastic wind power is described; and the required mathematical opti

  4. Leakage current analysis of a single-phase transformer-less PV inverter connected to the grid

    DEFF Research Database (Denmark)

    Ma, Lin; Tang, F.; Zhou, F.;

    2009-01-01

    Due to the large surface of the PV generator, its stray capacity with respect to the ground reaches values that can be quite high. When no transformer is used in a grid-connected PV system, common-mode current, which caused by the common mode voltage, can flow through the stray capacitance betwee...

  5. Look-Ahead Energy Management of a Grid-Connected Residential PV System with Energy Storage under Time-Based Rate Programs

    Directory of Open Access Journals (Sweden)

    Kyeon Hur

    2012-04-01

    Full Text Available This paper presents look-ahead energy management system for a grid-connected residential photovoltaic (PV system with battery under critical peak pricing for electricity, enabling effective and proactive participation of consumers in the Smart Grid’s demand response. In the proposed system, the PV is the primary energy source with the battery for storing (or retrieving excessive (or stored energy to pursue the lowest possible electricity bill but it is grid-tied to secure electric power delivery. Premise energy management scheme with an accurate yet practical load forecasting capability based on a Kalman filter is designed to increase the predictability in controlling the power flows among these power system components and the controllable electric appliances in the premise. The case studies with various operating scenarios demonstrate the validity of the proposed system and significant cost savings through operating the energy management scheme.

  6. PV grid connected system with fuzzy intelligent control

    Directory of Open Access Journals (Sweden)

    Florin DRAGOMIR

    2009-05-01

    Full Text Available This paper proposes an engineering solution for stability control of the low voltage electrical networks with distributed power generation from renewable energy resources. First there are presentedgenerally, the existing problems in this type of systems, capable to be solved with automation intelligent control. In the second part, the paper focuses over fuzzy controller design based on experimentalmonitored data and experts know how. The results of proposed software realized with LabView will be pointed out from the main objective point of view.

  7. A Frequency Locked Loop Grid Synchronization Method of Single-phase Grid-connected PV Inverter Under Weak Grid%弱电网下单相光伏并网逆变器锁频环同步方法

    Institute of Scientific and Technical Information of China (English)

    刘桂花; 曹小娇; 王卫

    2015-01-01

    One of the main electrical characteristics of weak grid is the high grid impedance, which will easily lead to grid voltage waveform distortion. Distorted grid voltage can resultin deviation or failure of the phase-locked loop of photovoltaic (PV) inverter, and power quality will deteriorate. In order to tackle this problem, targeting on the LC-type PV inverter,a synchronization method is proposed based on the second order generalized integrator frequency locked loop (SOGI-FLL). Initially, the impact of various grid states, especially the weak grid, on the inverter is analyzed. Then the operation principle of SOGI-FLL and its implementation method are set forth in detail. Simulation and experimental results demonstrate the validity of this synchronization method in grid voltage disturbance and zero-crossing oscillation. This synchronization method has strong robustness and adaptability for grid voltage changes. Compared with the conventional zero-crossing synchronization method, the SOGI-FLL synchronization method can improve the reliability of grid-connected PV inverters under weak grid.%弱电网的主要电气特性之一为高电网阻抗.高电网阻抗易导致电网电压波形畸变,畸变的电网电压会使光伏并网逆变器锁相环出现偏差甚至失效,并导致并网电能质量变差.针对这一问题,以LC型单相光伏并网逆变器为研究对象,提出采用基于2阶广义积分器锁频环(second order generalized integrator frequency locked loop,SOGI-FLL)同步方法来实现逆变器与弱电网的同步.在分析不同电网状态尤其是弱电网对逆变器影响的基础上,详细阐述SOGI-FLL的工作原理和实现方法.仿真和实验结果表明,该同步方法在电网电压扰动及过零点震荡情况下均可稳定可靠工作,对电网电压变化具有较强的鲁棒性和适应性,与传统过零同步方法相比,SOGI-FLL同步方法可提高弱电网下光伏并网逆变器的可靠性.

  8. A New Energy Management Technique for PV/Wind/Grid Renewable Energy System

    Directory of Open Access Journals (Sweden)

    Onur Ozdal Mengi

    2015-01-01

    Full Text Available An intelligent energy management system (IEMS for maintaining the energy sustainability in renewable energy systems (RES is introduced here. It consists of wind and photovoltaic (PV solar panels are established and used to test the proposed IEMS. Since the wind and solar sources are not reliable in terms of sustainability and power quality, a management system is required for supplying the load power demand. The power generated by RES is collected on a common DC bus as a renewable green power pool to be used for supplying power to loads. The renewable DC power bus is operated in a way that there is always a base power available for permanent loads. Then the additional power requirement is supplied from either wind or PV or both depending upon the availability of these power sources. The decision about operating these systems is given by an IEMS with fuzzy logic decision maker proposed in this study. Using the generated and required power information from the wind/PV and load sides, the fuzzy reasoning based IEMS determines the amount of power to be supplied from each or both sources. Besides, the IEMS tracks the maximum power operating point of the wind energy system.

  9. Design, Fabrication and Certification of Advanced Modular PV Power Systems

    Science.gov (United States)

    Minyard, Glen E.; Lambarski, Timothy J.

    1997-02-01

    The Design, Fabrication and Certification of Advanced Modular PV Power Systems contract is a Photovoltaic Manufacturing Technology (PVMaT) cost-shared contract under Phase 4A1 for Product Driven Systems and Component Technologies. Phase 4A1 has the goals to improve the cost-effectiveness and manufacturing efficiency of PV end-products, optimize manufacturing and packaging methods, and generally improve balance-of-system performance, integration and manufacturing. This contract has the specific goal to reduce the installed PV system life cycle costs to the customer with the ultimate goal of increasing PV system marketability and customer acceptance. The specific objectives of the project are to develop certified, standardized, modular, pre-engineered products lines of our main stand-alone systems, the Modular Autonomous PV Power Supply (MAPPS) and PV-Generator Hybrid System (Photogenset). To date, we have designed a 200 W MAPPS and a 1 kW Photogenset and are in the process of having the MAPPS certified by Underwriters Laboratories (UL Listed) and approved for hazardous locations by Factory Mutual (FM). We have also developed a manufacturing plan for product line expansion for the MAPPS. The Photogenset will be fabricated in February 1997 and will also be UL Listed. Functionality testing will be performed at NREL and Sandia with the intentions of providing verification of performance and reliability and of developing test-based performance specifications. In addition to an expansion on the goals, objectives and status of the project, specific accomplishments and benefits are also presented in this paper.

  10. Defending the Power Grid from Hackers

    Energy Technology Data Exchange (ETDEWEB)

    Eber, Kevin

    2016-10-01

    A new initiative underway at the National Renewable Energy Laboratory is intended to prevent hackers from gaining control of parts of the nation's power grid, potentially damaging electrical equipment and causing localized power outages. Our nation's power grid is evolving to be more responsive to changing power needs, more able to integrate renewable energy, more efficient, and more reliable. One key element of this evolution is adding communication and control devices to the power grid, closer to the end user, so that utilities have greater situational awareness of the grid and can respond quickly to disturbances. But these new devices and their communications requirements can also open up the power grid to potential cyber attacks.

  11. Sevilla PV a.2 MW- Photovoltaic plant grid; Sevilla PV 1.2 MW-Central Fotovoltaica de conexion a red con doble concentracion y seguimiento solar en dos ejes

    Energy Technology Data Exchange (ETDEWEB)

    Valera, P.; Enrile, J.; Osuna, R.; Alonso Abella, M.; Chenlo, F.

    2004-07-01

    The purpose of this project is to install a 1.2 MW, double concentration Photovoltaic plant grid connected to the utility for electricity generation to set the basis of a significant cost reduction in the generation of PV energy. Two concepts are considered: low concentration (effective factor of 2.2X) and two-axis sun tracking. The project takes advantages of the Spanish Royal Decree 436/2004 on production of electricity by PV systems. The solar feed in tariff for these systems is fixed in approximately 0.22 /kWh for system of a power output greater than 100kW. This will contribute to pay back the initial investment; to develop and prove the new PV technology and reduce GHG emissions, helping to the European White Paper target. (Author)

  12. Design for Reliability of Power Electronics for Grid-Connected Photovoltaic Systems

    DEFF Research Database (Denmark)

    Yang, Yongheng; Sangwongwanich, Ariya; Blaabjerg, Frede

    2016-01-01

    Power electronics is the enabling technology for optimizing energy harvesting from renewable systems like Photovoltaic (PV) and wind power systems, and also for interfacing grid-friendly energy systems. Advancements in the power semiconductor technology (e.g., wide band-gap devices) have pushed...... the conversion efficiency of power electronics to above 98%, where however te reliability of power electronics is becoming of high concern. Therefore, it is important to design for reliable power electronic systems to lower the risks of many failures during operation; otherwise will increase the cost...... for maintenance and reputation, thus affecting the cost of PV energy. Today's PV power conversion applications require the power electronic systems with low failure rates during a service life of 20 years or even more. To achieve so, it is vital to know the main life-limiting factors of power electronic systems...

  13. Profitability of smart grid solutions applied in power grid

    Directory of Open Access Journals (Sweden)

    Katić Nenad A.

    2016-01-01

    Full Text Available The idea of a Smart Grid solution has been developing for years, as complete solution for a power utility, consisting of different advanced technologies aimed at improving of the efficiency of operation. The trend of implementing various smart systems continues, e.g. Energy Management Systems, Grid Automation Systems, Advanced Metering Infrastructure, Smart power equipment, Distributed Energy Resources, Demand Response systems, etc. Futhermore, emerging technologies, such as energy storages, electrical vehicles or distributed generators, become integrated in distribution networks and systems. Nowadays, the idea of a Smart Grid solution becomes more realistic by full integration of all advanced operation technologies (OT within IT environment, providing the complete digitalization of an Utility (IT/OT integration. The overview of smart grid solutions, estimation of investments, operation costs and possible benefits are presented in this article, with discusison about profitability of such systems.

  14. Experimental Evaluation of PV Inverter Anti-Islanding with Grid Support Functions in Multi-Inverter Island Scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Hoke, Anderson [National Renewable Energy Lab. (NREL), Golden, CO (United States); Nelson, Austin [National Renewable Energy Lab. (NREL), Golden, CO (United States); Miller, Brian [National Renewable Energy Lab. (NREL), Golden, CO (United States); Chakraborty, Sudipta [National Renewable Energy Lab. (NREL), Golden, CO (United States); Bell, Frances [SolarCity, San Mateo, CA (United States); McCarty, Michael [SolarCity, San Mateo, CA (United States)

    2016-07-01

    As PV and other DER systems are connected to the grid at increased penetration levels, island detection may become more challenging for two reasons: 1.) In islands containing many DERs, active inverter-based anti-islanding methods may have more difficulty detecting islands because each individual inverter's efforts to detect the island may be interfered with by the other inverters in the island. 2.) The increasing numbers of DERs are leading to new requirements that DERs ride through grid disturbances and even actively try to regulate grid voltage and frequency back towards nominal operating conditions. These new grid support requirements may directly or indirectly interfere with anti-islanding controls. This report describes a series of tests designed to examine the impacts of both grid support functions and multi-inverter islands on anti-islanding effectiveness. Crucially, the multi-inverter anti-islanding tests described in this report examine scenarios with multiple inverters connected to multiple different points on the grid. While this so-called 'solar subdivision' scenario has been examined to some extent through simulation, this is the first known work to test it using hardware inverters. This was accomplished through the use of power hardware-in-the-loop (PHIL) simulation, which allows the hardware inverters to be connected to a real-time transient simulation of an electric power system that can be easily reconfigured to test various distribution circuit scenarios. The anti-islanding test design was a modified version of the unintentional islanding test in IEEE Standard 1547.1, which creates a balanced, resonant island with the intent of creating a highly challenging condition for island detection. Three common, commercially available single-phase PV inverters from three different manufacturers were tested. The first part of this work examined each inverter individually using a series of pure hardware resistive-inductive-capacitive (RLC

  15. Best practices for mitigating soiling risk on PV power plants

    KAUST Repository

    AlDowsari, A.

    2015-09-24

    Solar power generates proven, predictable and economical energy and new innovations have made solar PV power plants easy to deploy, integrate and maintain. Areas with large solar energy potential are among the dustiest in the world. At first glance, solar would be a natural fit in many of these environments but humidity, airborne dust, and wind of these regions often bring high soiling rates that can accumulate to reduce performance by up to 10% per month on average, where soiling can be a major loss factor that affects the energy yield for PV plants especially in humid and dusty climates. Therefore, to achieve the desired performance ratio and obtain stable generation, mitigation solutions are proposed to overcome dust issues that affect the performance of PV plants. This makes PV module cleaning a key component for long-term plant performance and sustainable profitability. In this paper, a review of the mechanisms and mitigation solutions to overcome soiling on solar installations using real-world testing and verification is investigated with emphasis on dry type cleaning methods. © 2014 IEEE.

  16. Reactive Power Injection Strategies for Single-Phase Photovoltaic Systems Considering Grid Requirements

    DEFF Research Database (Denmark)

    Yang, Yongheng; Wang, Huai; Blaabjerg, Frede

    2014-01-01

    like what the conventional power plants do today in the grid regulation participation. Requirements of ancillary services like Low-Voltage Ride-Through (LVRT) associated with reactive current injection and voltage support through reactive power control, have been in effectiveness in some countries...... possibilities are: a) constant average active power control, b) constant active current control, c) constant peak current control and d) thermal optimized control strategy. All those strategies comply with the currently active grid codes, but are with different objectives. The thermal optimized control strategy....... Those advanced features can be provided by next-generation PV systems, and will be enhanced in the future to ensure an even efficient and reliable utilization of PV systems. In the light of this, Reactive Power Injection (RPI) strategies for single-phase PV systems are explored in this paper. The RPI...

  17. Reactive Power Injection Strategies for Single-Phase Photovoltaic Systems Considering Grid Requirements

    DEFF Research Database (Denmark)

    Yang, Yongheng; Wang, Huai; Blaabjerg, Frede

    2014-01-01

    like what the conventional power plants do today in the grid regulation participation. Requirements of ancillary services like Low-Voltage Ride-Through (LVRT) associated with reactive current injection and voltage support through reactive power control, have been in effectiveness in some countries, e...... in this paper. The RPI possibilities are: a) constant average active power control, b) constant active current control, c) constant peak current control and d) thermal optimized control strategy. All those strategies comply with the currently active grid codes, but are with different objectives. The proposed.......g. Germany and Italy. Those advanced features can be provided by next generation PV systems, and will be enhanced in the future to ensure an even efficient and reliable utilization of PV systems. In light of this, Reactive Power Injection (RPI) strategies for single-phase PV systems are explored...

  18. Performance evaluation of 10 MW grid connected solar photovoltaic power plant in India

    Directory of Open Access Journals (Sweden)

    B. Shiva Kumar

    2015-11-01

    Full Text Available The growing energy demand in developing nations has triggered the issue of energy security. This has made essential to utilize the untapped potential of renewable resources. Grid connected PV systems have become the best alternatives in renewable energy at large scale. Performance analysis of these grid connected plants could help in designing, operating and maintenance of new grid connected systems. A 10 MW photovoltaic grid connected power plant commissioned at Ramagundam is one of the largest solar power plants with the site receiving a good average solar radiation of 4.97 kW h/m2/day and annual average temperature of about 27.3 degrees centigrade. The plant is designed to operate with a seasonal tilt. In this study the solar PV plant design aspects along with its annual performance is elaborated. The various types of power losses (temperature, internal network, power electronics, grid connected etc. and performance ratio are also calculated. The performance results of the plant are also compared with the simulation values obtained from PV syst and PV-GIS software. The final yield (Y F of plant ranged from 1.96 to 5.07 h/d, and annual performance ratio (PR of 86.12%. It has 17.68% CUF with annual energy generation of 15798.192 MW h/Annum.

  19. High power/large area PV systems

    Science.gov (United States)

    Wise, Joseph; Baraona, Cosmo

    1987-01-01

    The major photovoltaic power system technology drivers for a wide variety of mission types were ranked. Each technology driver was ranked on a scale of high, medium, or low in terms of importance to each particular mission type. The rankings were then compiled to determine the overall importance of each driver over the entire range of space missions. In each case cost was ranked the highest.

  20. Power Grid:Connecting the world

    Institute of Scientific and Technical Information of China (English)

    Liu Liang; Zhu Li

    2012-01-01

    With the acceleration of global economic integration,the trend has been towards opening up markets.Large enterprises in countries around the world,the developed countries in particular,attach great importance to going abroad,with the aim to optimally allocate energy resources in a wider range.Actively responding to the "going out" strategy of the State,the two giant power grid enterprises in China,State Grid Corporation of China (SGCC) and China Southern Power Grid (CSG),have made plans for grid development in line with the State's energy strategy and global resources allocation.

  1. Power control flexibilities for grid-connected multi-functional photovoltaic inverters

    DEFF Research Database (Denmark)

    Yang, Yongheng; Blaabjerg, Frede; Wang, Huai

    2014-01-01

    This paper explores the next-generation Photo- Voltaic (PV) system integration issues at a high penetration level, where the grid is becoming more decentralized and vulnerable. Therefore, the PV systems are expected to be more controllable with higher efficiency and higher reliability. Provision...... to generate appropriate references for the inner current control loop. The references depend on the system conditions and also specific demands from both system operators and customers. Besides, this power control strategy can be implemented in a commercial PV inverter as standardized functions, and also...

  2. Reviewing the potential and cost-effectiveness of grid-connected solar PV in Indonesia on a provincial level

    NARCIS (Netherlands)

    Veldhuis, A.J.; Reinders, A.H.M.E.

    2013-01-01

    Photovoltaic (PV) energy could play a large role in increasing the electrification ratio and decreasing greenhouse gas emissions in Indonesia, especially since Indonesia comprises over 17,000 islands which is a challenge for the distribution of fuels and modern grid connection. The potential of grid

  3. Spontaneous synchrony in power-grid networks

    CERN Document Server

    Motter, Adilson E; Anghel, Marian; Nishikawa, Takashi

    2013-01-01

    An imperative condition for the functioning of a power-grid network is that its power generators remain synchronized. Disturbances can prompt desynchronization, which is a process that has been involved in large power outages. Here we derive a condition under which the desired synchronous state of a power grid is stable, and use this condition to identify tunable parameters of the generators that are determinants of spontaneous synchronization. Our analysis gives rise to an approach to specify parameter assignments that can enhance synchronization of any given network, which we demonstrate for a selection of both test systems and real power grids. Because our results concern spontaneous synchronization, they are relevant both for reducing dependence on conventional control devices, thus offering an additional layer of protection given that most power outages involve equipment or operational errors, and for contributing to the development of "smart grids" that can recover from failures in real time.

  4. Wind power and transmission grid planning

    Energy Technology Data Exchange (ETDEWEB)

    Matilainen, J.A. [Finnish Transmission System Operator Fingrid, Helsinki (Finland); Haarla, L.C. [Helsinki Univ. of Technology, TKK (Finland). Dept. of Electrical Engineering

    2008-07-01

    This paper presents a method that combines the electricity market and power flow models and describes how they were used for transmission grid planning with large amounts of wind power in the power system. The market model (EMPS) is used by the Nordic Transmission System Operators (TSO), producers and market analysts. There are different possibilities to model the wind power in EMPS and different ways lead to different results. The paper presents a method for analysing the impacts of wind power by modifying the wind power representation in the market model. The paper presents how the purpose of the study (e.g. energy balance or dynamic impacts) should be taken into account when deciding which wind power modelling method to use. Additionally, an example of utilizing the models for planning the Nordic grid is described in this paper. The combined market and power flow software (Samlast) also has grid models inside the price areas and therefore it enables further grid analysis such as dynamic simulations. The paper presents the results of the combined model and different ways of using the results. The combined model can be used both for energy based grid analysis and for support of power flow analysis. The results show that there is a need of transmission grid investments in Finland if 4 GW wind power would be installed. (orig.)

  5. Power Output Improvement of PV Module for Agricultural Use by Using Inexpensive Sunlight Concentrator

    Institute of Scientific and Technical Information of China (English)

    NISHIMURA Ryo

    2010-01-01

    PV modules are used as stand alone power sources for agricultural equipments such as lifting pumps in farms,where the power infrastructure is not yet improved.In order to expand the agricultural use of PV module,the cost of PV generation should be reduced.In this paper,the power output performance of a commercial PV module was improved by using a sunlight concentrator that could be assembled inexpensively and a simple sun-tracking method.

  6. New control strategy for 2-stage grid-connected photovoltaic power system

    Energy Technology Data Exchange (ETDEWEB)

    Hamrouni, N.; Jraidi, M.; Cherif, A. [Laboratory of Electrical Systems, Engineering Faculty of Tunis, PB 37, 1002 Belvedere, Tunis (Tunisia)

    2008-10-15

    This work deals with the performances and responses of a grid-connected photovoltaic (PV) plant in normal and disturbed modes. The system is composed of a solar array, a dc-dc converter and a three-phase inverter connected to the utility grid. On the one hand a suitable control of the dc-dc converter is developed in order to extract the maximum amount of power from the PV generator. On the other hand an active and reactive power control approach (PQ) has been presented for the inverter. This method can provide a current with sinusoidal waveform and ensure a high power factor. Therefore, the grid interface inverter transfers the energy drawn from the PV into the grid by ensuring constant dc link voltage. Modeling and controlling were carried out using the informational graph of causality and the macroscopic energy representation methods. The simulation under MATLAB/SIMULINK and the experimental results show the control performance and dynamic behavior of grid-connected PV system in normal and disturbances modes. (author)

  7. Advanced Grid Support Functionality Testing for Florida Power and Light

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Austin [National Renewable Energy Lab. (NREL), Golden, CO (United States); Martin, Gregory [National Renewable Energy Lab. (NREL), Golden, CO (United States); Hurtt, James [Florida Power and Light, Juno Beach, FL (United States)

    2017-03-21

    This report describes the results of laboratory testing of advanced photovoltaic (PV) inverter testing undertaken by the National Renewable Energy Laboratory (NREL) on behalf of the Florida Power and Light Company (FPL). FPL recently commissioned a 1.1 MW-AC PV installation on a solar carport at the Daytona International Speedway in Daytona Beach, Florida. In addition to providing a source of clean energy production, the site serves as a live test bed with 36 different PV inverters from eight different manufacturers. Each inverter type has varied support for advanced grid support functions (GSFs) that are becoming increasingly commonplace, and are being required through revised interconnection standards such as UL1741, IEEE1547, and California (CA) Rule 21. FPL is interested in evaluating the trade-offs between different GSFs, their compliance to emerging standards, and their effects on efficiency and reliability. NREL has provided a controlled laboratory environment to undertake such a study. This work covered nine different classes of tests to compare inverter capabilities and performance for four different inverters that were selected by FPL. The test inverters were all three-phase models rated between 24-36 kW, and containing multiple PV input power point trackers. Advanced grid support functions were tested for functional behavior, and included fixed power factor operation, voltage-ride through, frequency ride-through, volt-var control, and frequency-Watt control. Response to abnormal grid conditions with GSFs enabled was studied through anti-islanding, fault, and load rejection overvoltage tests. Finally, efficiency was evaluated across a range of operating conditions that included power factor, output power, and input voltage variations. Test procedures were derived from requirements of a draft revision of UL741, CA Rule 21, and/or previous studies at NREL. This reports summarizes the results of each test case, providing a comparative performance analysis

  8. Rapid Active Power Control of Photovoltaic Systems for Grid Frequency Support

    Energy Technology Data Exchange (ETDEWEB)

    Hoke, Anderson; Shirazi, Mariko; Chakraborty, Sudipta; Muljadi, Eduard; Maksimovic, Dragan

    2017-01-01

    As deployment of power electronic coupled generation such as photovoltaic (PV) systems increases, grid operators have shown increasing interest in calling on inverter-coupled generation to help mitigate frequency contingency events by rapidly surging active power into the grid. When responding to contingency events, the faster the active power is provided, the more effective it may be for arresting the frequency event. This paper proposes a predictive PV inverter control method for very fast and accurate control of active power. This rapid active power control method will increase the effectiveness of various higher-level controls designed to mitigate grid frequency contingency events, including fast power-frequency droop, inertia emulation, and fast frequency response, without the need for energy storage. The rapid active power control method, coupled with a maximum power point estimation method, is implemented in a prototype PV inverter connected to a PV array. The prototype inverter's response to various frequency events is experimentally confirmed to be fast (beginning within 2 line cycles and completing within 4.5 line cycles of a severe test event) and accurate (below 2% steady-state error).

  9. Power grid integration using Kalman filtering

    OpenAIRE

    Djerf, Magnus

    2012-01-01

    Renewable power sources with a relatively uneven or constant DC power production require synchronization methods to work with the current utility power grid. The solution to this synchronization problem has been solved with semiconductor based converters and advanced switching algorithms. To enable switching algorithms that work well with the grids amplitude, phase-shift and frequency, the current waveform has to be measured and estimated.    There are many sources of noise that will add dist...

  10. Sustainable electricity generation by solar pv/diesel hybrid system without storage for off grids areas

    Science.gov (United States)

    Azoumah, Y.; Yamegueu, D.; Py, X.

    2012-02-01

    Access to energy is known as a key issue for poverty reduction. The electrification rate of sub Saharan countries is one of the lowest among the developing countries. However this part of the world has natural energy resources that could help raising its access to energy, then its economic development. An original "flexy energy" concept of hybrid solar pv/diesel/biofuel power plant, without battery storage, is developed in order to not only make access to energy possible for rural and peri-urban populations in Africa (by reducing the electricity generation cost) but also to make the electricity production sustainable in these areas. Some experimental results conducted on this concept prototype show that the sizing of a pv/diesel hybrid system by taking into account the solar radiation and the load/demand profile of a typical area may lead the diesel generator to operate near its optimal point (70-90 % of its nominal power). Results also show that for a reliability of a PV/diesel hybrid system, the rated power of the diesel generator should be equal to the peak load. By the way, it has been verified through this study that the functioning of a pv/Diesel hybrid system is efficient for higher load and higher solar radiation.

  11. S4 Grid-Connected Single-Phase Transformerless Inverter for PV Application

    DEFF Research Database (Denmark)

    Ardashir, Jaber Fallah; Siwakoti, Yam Prasad; Sabahi, Mehran

    2016-01-01

    This paper introduces a new single-phase transformerless inverter for grid-connected photovoltaic systems with low leakage current. It consists of four power switches, two diodes, two capacitors and a filter at the output stage. The neutral of the grid is directly connected to the negative termin...

  12. Operation of TUT Solar PV Power Station Research Plant under Partial Shading Caused by Snow and Buildings

    Directory of Open Access Journals (Sweden)

    Diego Torres Lobera

    2013-01-01

    Full Text Available A grid connected solar photovoltaic (PV research facility equipped with comprehensive climatic and electric measuring systems has been designed and built in the Department of Electrical Engineering of the Tampere University of Technology (TUT. The climatic measuring system is composed of an accurate weather station, solar radiation measurements, and a mesh of irradiance and PV module temperature measurements located throughout the solar PV facility. Furthermore, electrical measurements can be taken from single PV modules and strings of modules synchronized with the climatic data. All measured parameters are sampled continuously at 10 Hz with a data-acquisition system based on swappable I/O card technology and stored in a database for later analysis. The used sampling frequency was defined by thorough analyses of the PV system time dependence. Climatic and electrical measurements of the first operation year of the research facility are analyzed in this paper. Moreover, operation of PV systems under partial shading conditions caused by snow and building structures is studied by means of the measured current and power characteristics of PV modules and strings.

  13. RMS Current of a Photovoltaic Generator in Grid-Connected PV Systems: Definition and Application

    Directory of Open Access Journals (Sweden)

    P. J. Pérez

    2008-01-01

    Full Text Available This paper includes a definition of a new and original concept in the photovoltaic field, RMS current of a photovoltaic generator for grid-connected systems. The RMS current is very useful for calculating energy losses in cables used in a PV generator. As well, a current factor has been defined in order to simplify RMS current calculation. This factor provides an immediate (quick and easy calculation method for the RMS current that does not depend on the case particular conditions (orientation, location, etc.. RMS current and current factor values have been calculated for different locations and modules.

  14. Modeling of a Photovoltaic-Powered Electric Vehicle Charging Station with Vehicle-to-Grid Implementation

    Directory of Open Access Journals (Sweden)

    Azhar Ul-Haq

    2016-12-01

    Full Text Available This paper is aimed at modelling of a distinct smart charging station for electric vehicles (EVs that is suitable for DC quick EV charging while ensuring minimum stress on the power grid. Operation of the charging station is managed in such a way that it is either supplied by photovoltaic (PV power or the power grid, and the vehicle-to-grid (V2G is also implemented for improving the stability of the grid during peak load hours. The PV interfaced DC/DC converter and grid interfaced DC/AC bidirectional converter share a DC bus. A smooth transition of one operating mode to another demonstrates the effectiveness of the employed control strategy. Modelling and control of the different components are explained and are implemented in Simulink. Simulations illustrate the feasible behaviour of the charging station under all operating modes in terms of the four-way interaction among PV, EVs and the grid along with V2G operation. Additionally, a business model is discussed with comprehensive analysis of cost estimation for the deployment of charging facilities in a residential area. It has been recognized that EVs bring new opportunities in terms of providing regulation services and consumption flexibility by varying the recharging power at a certain time instant. The paper also discusses the potential financial incentives required to inspire EV owners for active participation in the demand response mechanism.

  15. Spontaneous synchrony in power-grid networks

    Science.gov (United States)

    Motter, Adilson E.; Myers, Seth A.; Anghel, Marian; Nishikawa, Takashi

    2013-03-01

    An imperative condition for the functioning of a power-grid network is that its power generators remain synchronized. Disturbances can prompt desynchronization, which is a process that has been involved in large power outages. Here we derive a condition under which the desired synchronous state of a power grid is stable, and use this condition to identify tunable parameters of the generators that are determinants of spontaneous synchronization. Our analysis gives rise to an approach to specify parameter assignments that can enhance synchronization of any given network, which we demonstrate for a selection of both test systems and real power grids. These findings may be used to optimize stability and help devise new control schemes, thus offering an additional layer of protection and contributing to the development of smart grids that can recover from failures in real time.

  16. Models for the modern power grid

    Science.gov (United States)

    Nardelli, Pedro H. J.; Rubido, Nicolas; Wang, Chengwei; Baptista, Murilo S.; Pomalaza-Raez, Carlos; Cardieri, Paulo; Latva-aho, Matti

    2014-10-01

    This article reviews different kinds of models for the electric power grid that can be used to understand the modern power system, the smart grid. From the physical network to abstract energy markets, we identify in the literature different aspects that co-determine the spatio-temporal multilayer dynamics of power system. We start our review by showing how the generation, transmission and distribution characteristics of the traditional power grids are already subject to complex behaviour appearing as a result of the the interplay between dynamics of the nodes and topology, namely synchronisation and cascade effects. When dealing with smart grids, the system complexity increases even more: on top of the physical network of power lines and controllable sources of electricity, the modernisation brings information networks, renewable intermittent generation, market liberalisation, prosumers, among other aspects. In this case, we forecast a dynamical co-evolution of the smart grid and other kind of networked systems that cannot be understood isolated. This review compiles recent results that model electric power grids as complex systems, going beyond pure technological aspects. From this perspective, we then indicate possible ways to incorporate the diverse co-evolving systems into the smart grid model using, for example, network theory and multi-agent simulation.

  17. Probability of islanding in utility networks due to grid connected photovoltaic power systems

    Energy Technology Data Exchange (ETDEWEB)

    Verhoeven, B.

    2002-09-15

    This report for the International Energy Agency (IEA) made by Task 5 of the Photovoltaic Power Systems (PVPS) programme takes a look at the probability of islanding in utility networks due to grid-connected photovoltaic power systems. The mission of the Photovoltaic Power Systems Programme is to enhance the international collaboration efforts which accelerate the development and deployment of photovoltaic solar energy. Task 5 deals with issues concerning grid-interconnection and distributed PV power systems. This report summarises the results on a study on the probability of islanding in power networks with a high penetration level of grid connected PV-systems. The results are based on measurements performed during one year in a Dutch utility network. The measurements of active and reactive power were taken every second for two years and stored in a computer for off-line analysis. The area examined and its characteristics are described, as are the test set-up and the equipment used. The ratios between load and PV-power are discussed. The general conclusion is that the probability of islanding is virtually zero for low, medium and high penetration levels of PV-systems.

  18. Exact Power Constraints in Smart Grid Control

    DEFF Research Database (Denmark)

    Trangbæk, K; Petersen, Mette Højgaard; Bendtsen, Jan Dimon

    2011-01-01

    This paper deals with hierarchical model predictive control (MPC) of smart grid systems. The objective is to accommodate load variations on the grid, arising from varying consumption and natural variations in the power production e.g. from wind turbines. This balancing between supply and demand...

  19. A Novel Approach on Photovoltaic Technologies for Power Injection in Grid Using Matlab-Simulink

    Directory of Open Access Journals (Sweden)

    Er. Navjot Kaur

    2014-09-01

    Full Text Available The paper presents the simulation of the Solar Photovoltaic module using Matlab Simulink. This model is based on mathematical equations and is described through an equivalent circuit including a photocurrent source, a diode, a series resistor and a shunt resistor. This paper presents integration of the grid distribution network in Indian scenario with solar power technology to meet the additional electrical energy demand of urban as well as rural sectors which are both rapidly expanding. First of all the data of a real life power plant having 24V, 230W Power PV module has been compared and analyzed with that of matlab program output for identical module and it has been find out that a variation in temperature affects the parameters values as well as the performance of the solar module. After the above analysis the design and Simulink implementation for single phase power grid connected PV system has been done. The system includes the PV array model, the integration of the MPPT with boost dc converter , dc to ac inverter, single phase series load connected to ac grid. It is demonstrated that the model works well at different temperature conditions and predicting the General behavior of single-phase grid- connected PV systems .

  20. Spatial and Temporal Characteristics of PV Adoption in the UK and Their Implications for the Smart Grid

    Directory of Open Access Journals (Sweden)

    J. Richard Snape

    2016-03-01

    Full Text Available Distributed renewable electricity generators facilitate decarbonising the electricity network, and the smart grid allows higher renewable penetration while improving efficiency. Smart grid scenarios often emphasise localised control, balancing small renewable generation with consumer electricity demand. This research investigates the applicability of proposed decentralised smart grid scenarios utilising a mixed strategy: quantitative analysis of PV adoption data and qualitative policy analysis focusing on policy design, apparent drivers for adoption of the deviation of observed data from the feed-in tariff impact assessment predictions. Analysis reveals that areas of similar installed PV capacity are clustered, indicating a strong dependence on local conditions for PV adoption. Analysing time series of PV adoption finds that it fits neither neo-classical predictions, nor diffusion of innovation S-curves of adoption cleanly. This suggests the influence of external factors on the decision making process. It is shown that clusters of low installed PV capacity coincide with areas of high population density and vice versa, implying that while visions of locally-balanced smart grids may be viable in certain rural and suburban areas, applicability to urban centres may be limited. Taken in combination, the data analysis, policy impact and socio-psychological drivers of adoption demonstrate the need for a multi-disciplinary approach to understanding and modelling the adoption of technology necessary to enable the future smart grid.

  1. The Integration and Control of Multifunctional Stationary PV-Battery Systems in Smart Distribution Grid

    DEFF Research Database (Denmark)

    Khan, Mohammad Rezwan; Mulder, Grietus; Van Mierlo, Joeri

    2013-01-01

    . The objective of this paper is to develop and detail the method of optimum sizing energy storage for grid connected distribution systems using newly devised BESS control protocol and investigate its sensitivity to factors which are known to influence energy system performance and hence storage requirements......The paper investigates the potential of using lumped stationary battery energy storage systems (BESS) in the public low-voltage distribution grid in order to defer upgrades needed in case of large penetration of electric vehicle (EV), electrified heat pump (HP) in presence of photovoltaic (PV......) panel on the view of techno economic optimal sizing taking the consideration of season-based diurnal dynamics. The BESS is primarily dimensioned for the peak shaving operation targeted for the counterbalance of overloading of transformer; BESS also participates in arbitrage (buy low, sell high...

  2. Dynamic Wireless Power Transfer - Grid Impacts Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Markel, Tony; Meintz, Andrew; Gonder, Jeff

    2015-12-04

    This presentation discusses the current status of analysis of the electricity grid impacts of a dynamic wireless power transfer system deployed to the Atlanta region on select high traffic roadway segments.

  3. Analysis on Design of Grid-connected PV System%并网光伏系统设计简析

    Institute of Scientific and Technical Information of China (English)

    罗刚; 俞晟

    2014-01-01

    简要介绍常见并网光伏系统设计依据、常用软件、组成部分及其原理,以及光设计中需要把握的原则、注意事项和一些经验教训,包括光伏支架、光伏方阵与场地的设计考虑,并网逆变器的选择、并网形式的选择、防雷接地等。%The paper provides a brief introduction of the design basis, common software, components and principles of common grid-connected PV system, as well as principles, considerations and some experiences in PV design, including the design considerations of PV stent, PV array and venue, selection of grid-connected inverter and form and grounding for protection against lightning.

  4. Power of design - the future of building-integrated PV

    Energy Technology Data Exchange (ETDEWEB)

    Abbate, Cinzia [ENEL, Rome (Italy). Officine di Architettura

    2001-04-01

    This paper discusses strategies to make building integrated photovoltaic (PV) systems more acceptable and to allow PV material to compete with conventional construction material. The history of developments in building integration and difficulties encountered by architects wishing to use PV products are explored, and the Dutch Amersfoot project in Utrecht involving a new suburb of 501 house covered with PV panels is described. Questions raised regarding architectural integration of PV systems, and PV systems and the construction market are discussed. The Italian PV programme, financial and political constraints, and the positioning of PV on existing structures are reported.

  5. Voltage Stability Impact of Grid-Tied Photovoltaic Systems Utilizing Dynamic Reactive Power Control

    Science.gov (United States)

    Omole, Adedamola

    Photovoltaic (PV) DGs can be optimized to provide reactive power support to the grid, although this feature is currently rarely utilized as most DG systems are designed to operate with unity power factor and supply real power only to the grid. In this work, the voltage stability of a power system embedded with PV DG is examined in the context of the high reactive power requirement after a voltage sag or fault. A real-time dynamic multi-function power controller that enables renewable source PV DGs to provide the reactive power support necessary to maintain the voltage stability of the microgrid, and consequently, the wider power system is proposed. The loadability limit necessary to maintain the voltage stability of an interconnected microgrid is determined by using bifurcation analysis to test for the singularity of the network Jacobian and load differential equations with and without the contribution of the DG. The maximum and minimum real and reactive power support permissible from the DG is obtained from the loadability limit and used as the limiting factors in controlling the real and reactive power contribution from the PV source. The designed controller regulates the voltage output based on instantaneous power theory at the point-of-common coupling (PCC) while the reactive power supply is controlled by means of the power factor and reactive current droop method. The control method is implemented in a modified IEEE 13-bus test feeder system using PSCADRTM power system analysis software and is applied to the model of a Tampa ElectricRTM PV installation at Lowry Park Zoo in Tampa, FL. This dissertation accomplishes the systematic analysis of the voltage impact of a PV DG-embedded power distribution system. The method employed in this work bases the contribution of the PV resource on the voltage stability margins of the microgrid rather than the commonly used loss-of-load probability (LOLP) and effective load-carrying capability (ELCC) measures. The results of

  6. Feasibility Study of Grid Connected PV-Biomass Integrated Energy System in Egypt

    Science.gov (United States)

    Barakat, Shimaa; Samy, M. M.; Eteiba, Magdy B.; Wahba, Wael Ismael

    2016-10-01

    The aim of this paper is to present a feasibility study of a grid connected photovoltaic (PV) and biomass Integrated renewable energy (IRE) system providing electricity to rural areas in the Beni Suef governorate, Egypt. The system load of the village is analyzed through the environmental and economic aspects. The model has been designed to provide an optimal system configuration based on daily data for energy availability and demands. A case study area, Monshaet Taher village (29° 1' 17.0718"N, 30° 52' 17.04"E) is identified for economic feasibility in this paper. HOMER optimization model plan imputed from total daily load demand, 2,340 kWh/day for current energy consuming of 223 households with Annual Average Insolation Incident on a Horizontal Surface of 5.79 (kWh/m2/day) and average biomass supplying 25 tons / day. It is found that a grid connected PV-biomass IRE system is an effective way of emissions reduction and it does not increase the investment of the energy system.

  7. Power Line Communications for Smart Grid Applications

    Directory of Open Access Journals (Sweden)

    Lars Torsten Berger

    2013-01-01

    Full Text Available Power line communication, that is, using the electricity infrastructure for data transmission, is experiencing a renaissance in the context of Smart Grid. Smart Grid objectives include the integration of intermittent renewable energy sources into the electricity supply chain, securing reliable electricity delivery, and using the existing electrical infrastructure more efficiently. This paper surveys power line communications (PLCs in the context of Smart Grid. The specifications G3-PLC, PRIME, HomePlug Green PHY, and HomePlug AV2, and the standards IEEE 1901/1901.2 and ITU-T G.hn/G.hnem are discussed.

  8. A novel evolving model for power grids

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    In this paper,a novel power grid evolving model,which can well describe the evolving property of power grids,is presented. Based on the BA model,motivated by the fact that in real power grids,connectivity of node not only depends on its degree,but also is influenced by many uncertain factors,so we introduce the subconnection factor K for each node. Using the mean-field theory,we get the analytical expression of power-law degree distribution with the exponent γ∈ (3,∞ ). Finally,simulation results show that the new model can provide a satisfactory description for empirical characteristics of power network,and power network falls somewhere in between scale-free network and uncertain network.

  9. Constant Power Generation of Photovoltaic Systems Considering the Distributed Grid Capacity

    DEFF Research Database (Denmark)

    Yang, Yongheng; Blaabjerg, Frede; Wang, Huai

    2014-01-01

    With an imperative demand of clean and reliable electricity generation in some countries, the increasing adoption of new photovoltaic (PV) systems pushes the Distribution System Operators (DSOs) to expand the transmission/distributed lines. However, the potential cost brought by such extensions...... systems in CPG operation mode are also discussed in this paper. Additionally, the loss of energy is calculated to reveal the viability of the proposed CPG control method. Operation examples of a PV system are presented to show the effectiveness of the CPG control method to unload the distributed grid....... and increased maintenances introduce new obstacles. In view of this concern, the DSOs starts to reduce PV installations in order to avoid an extension of the power infrastructure. Besides, another alternative solution is to limit the maximum feed-in power of the existing PV systems to a certain level. It can...

  10. Three-Phase PV CHB Inverter for a Distributed Power Generation System

    Directory of Open Access Journals (Sweden)

    Pierluigi Guerriero

    2016-10-01

    Full Text Available This work deals with the design of a three-phase grid-tied photovoltaic (PV cascade H-bridge inverter for distributed power conversion. The power balancing among the phases must be properly addressed. In fact, an intra-phase power imbalance—arising from uneven irradiance and temperature conditions—generates a per-phase power imbalance. This latter can be compensated by the injection of a proper zero-sequence voltage, while the intra-phase balance is ensured by means of a hybrid modulation method which is able to guarantee the handling of unequal DC (Direct Current sources, stable circuit operation, and maximization of PV power production. The digital controller is developed and tested in Matlab/Simulink environment integrated with XSG (Xilinx System Generator, thus allowing an easy transfer on a field-programmable gate array (FPGA platform and accurately describing the behavior of a real hardware implementation. Thus, numerical results have been considered to prove the effectiveness of the proposed approach.

  11. Power Electronic System for Multi-MW PV sites

    DEFF Research Database (Denmark)

    Paasch, Kasper

    for solar inverters is under a severe pressure regarding cost reduction. The main topic of this thesis is the investigation of the potential advantage of applying string inverters with multiple Maximum-Power-Point-trackers (MPPT) in large PV plants compared to the use of one large central inverter with one.......4%. A portable IV-scanning instrument for the fast long term characterization of solar panels was developed as part of the project. Each second a sweep of the IV-characteristics of a solar panel is performed and the result stored for later analysis. The instrument is based on an active load, is optimized...

  12. Method for Load Sharing and Power Management in a Hybrid PV/Battery Source Islanded Microgrid

    DEFF Research Database (Denmark)

    Karimi, Yaser; Oraee, Hashem; Guerrero, Josep M.

    2016-01-01

    This paper presents a decentralized load sharing and power management method for an islanded microgrid composed of PV units, battery units and hybrid PV/battery units. The proposed method performs all the necessary tasks such as load sharing among the units, battery charging and discharging and PV...

  13. Switching overvoltages in offshore wind power grids

    DEFF Research Database (Denmark)

    Arana Aristi, Ivan

    Switching transients in wind turbines, the collection grid, the export system and the external grid in offshore wind farms, during normal or abnormal operation, are the most important phenomena when conducting insulation coordination studies. However, the recommended models and methods from...... international standards and guidelines are insufficient to take into account considering the special conditions in offshore wind farms. This thesis focuses on the improvement of models and methods used in specialized electromagnetic transient programs. In this thesis, an introduction to offshore wind farm...... and cables are presented. In Chapter 4 results from time domain measurements and simulations of switching operations in offshore wind power grids are described. Specifically, switching operations on a single wind turbine, the collection grid, the export system and the external grid measured in several real...

  14. A New Control Method for Grid-Connected PV System Based on Quasi-Z-Source Cascaded Multilevel Inverter Using Evolutionary Algorithm

    Directory of Open Access Journals (Sweden)

    Hamid Reza Mohammadi

    2015-03-01

    Full Text Available In this paper, a new control method for quasi-Z-source cascaded multilevel inverter based grid-connected photovoltaic (PV system is proposed. The proposed method is capable of boosting the PV array voltage to a higher level and solves the imbalance problem of DC-link voltage in traditional cascaded H-bridge inverters. The proposed control system adjusts the grid injected current in phase with the grid voltage and achieves independent maximum power point tracking (MPPT for the separate PV arrays. To achieve these goals, the proportional-integral (PI controllers are employed for each module. For achieving the best performance, this paper presents an optimum approach to design the controller parameters using particle swarm optimization (PSO. The primary design goal is to obtain good response by minimizing the integral absolute error. Also, the transient response is guaranteed by minimizing the overshoot, settling time and rise time of the system response. The effectiveness of the new proposed control method has been verified through simulation studies based on a seven level quasi-Z-Source cascaded multilevel inverter.

  15. Trimode Power Converter optimizes PV, diesel and battery energy sources

    Science.gov (United States)

    Osullivan, George; Bonn, Russell; Bower, Ward

    1994-12-01

    Conservatively, there are 100,000 localities in the world waiting for the benefits that electricity can provide, and many of these are in climates where sunshine is plentiful. With these locations in mind a prototype 30 kW hybrid system has been assembled at Sandia to prove the reliability and economics of photovoltaic, diesel and battery energy sources managed by an autonomous power converter. In the Trimode Power Converter the same power parts, four IGBT's with an isolation transformer and filter components, serve as rectifier and charger to charge the battery from the diesel; as a stand-alone inverter to convert PV and battery energy to AC; and, as a parallel inverter with the diesel-generator to accommodate loads larger than the rating of the diesel. Whenever the diesel is supplying the load, an algorithm assures that the diesel is running at maximum efficiency by regulating the battery charger operating point. Given the profile of anticipated solar energy, the cost of transporting diesel fuel to a remote location and a five year projection of load demand, a method to size the PV array, battery and diesel for least cost is developed.

  16. Multi-Input Converter with MPPT Feature for Wind-PV Power Generation System

    Directory of Open Access Journals (Sweden)

    Chih-Lung Shen

    2013-01-01

    Full Text Available A multi-input converter (MIC to process wind-PV power is proposed, designed, analyzed, simulated, and implemented. The MIC cannot only process solar energy but deal with wind power, of which structure is derived from forward-type DC/DC converter to step-down/up voltage for charger systems, DC distribution applications, or grid connection. The MIC comprises an upper modified double-ended forward, a lower modified double-ended forward, a common output inductor, and a DSP-based system controller. The two modified double-ended forwards can operate individually or simultaneously so as to accommodate the variation of the hybrid renewable energy under different atmospheric conditions. While the MIC operates at interleaving mode, better performance can be achieved and volume also is reduced. The proposed MIC is capable of recycling the energy stored in the leakage inductance and obtaining high step-up output voltage. In order to draw maximum power from wind turbine and PV panel, perturb-and-observe method is adopted to achieve maximum power point tracking (MPPT feature. The MIC is constructed, analyzed, simulated, and tested. Simulations and hardware measurements have demonstrated the feasibility and functionality of the proposed multi-input converter.

  17. Complex Network Analysis of Brazilian Power Grid

    CERN Document Server

    Martins, Gabriela C; Ribeiro, Fabiano L; Forgerini, Fabricio L

    2016-01-01

    Power Grids and other delivery networks has been attracted some attention by the network literature last decades. Despite the Power Grids dynamics has been controlled by computer systems and human operators, the static features of this type of network can be studied and analyzed. The topology of the Brazilian Power Grid (BPG) was studied in this work. We obtained the spatial structure of the BPG from the ONS (electric systems national operator), consisting of high-voltage transmission lines, generating stations and substations. The local low-voltage substations and local power delivery as well the dynamic features of the network were neglected. We analyze the complex network of the BPG and identify the main topological information, such as the mean degree, the degree distribution, the network size and the clustering coefficient to caracterize the complex network. We also detected the critical locations on the network and, therefore, the more susceptible points to lead to a cascading failure and even to a blac...

  18. Power Ramp Limitation capabilities of Large PV Power Plants with Active Power Reserves

    DEFF Research Database (Denmark)

    Bogdan, Craciun; Kerekes, Tamas; Sera, Dezso

    2017-01-01

    Power Ramp Limitation (PRL) is likely to become a requirement for large scale photovoltaic power plants (LPVPPs) in order to allow the increase of PV penetration levels. Especially in islands with reduced inertia capability, this problem is more stringent: high power ramp can be caused by either...... fast irradiance changes or other participant generators for example wind power, or loads. In order to compensate for the power mismatch, LPVPPs must use Active Power Reserve (APR), by either curtailment or auxiliary storage. The paper proposes a PRL control structure for dynamic APR sizing...... area of LPVPPs acts as filter against fast irradiance changes, the study reveals also the required plant size for which auxiliary storage is no longer needed in order to comply with PRL requirements – an important economical aspect....

  19. Power Talk in DC Micro Grids

    DEFF Research Database (Denmark)

    Angjelichinoski, Marko; Stefanovic, Cedomir; Popovski, Petar

    2015-01-01

    Power talk is a novel concept for communication among units in a Micro Grid (MG), where information is sent by using power electronics as modems and the common bus of the MG as a communication medium. The technique is implemented by modifying the droop control parameters from the primary control...

  20. 光伏发电并网系统相量模型建模研究%Research on Phasor Model of Grid Connection PV Generation System

    Institute of Scientific and Technical Information of China (English)

    邱革非; 张春刚; 仲泽坤; 字杨

    2015-01-01

    A grid connection photovoltaic power generation system model is built in this paper.By this model, power characters of power grid which is connected with PV generation systems can be researched without igno-rance of the characters of PV generation system.Based on phasor analyzing method,PV generation system with power output controlling unit is built in detail,so that it can reflect actual controlling characteristics of PV system truthfully.Compared with existing grid connection PV models,it has the advantage of faster simulation,which can be applied to power system researches on power transferring and controlling characteristics of power system based on phasor analysis.%建立了一个既适用于电力系统网络功率分析,同时也能够在仿真过程中较为细致地反映光伏发电系统实际并网运行特性的并网光伏发电系统模型。文中以相量分析为基础对包含功率控制单元在内的发电系统进行了较为详细的相量建模,使得所建立的发电系统模型能够更为真实地体现光伏发电系统功率输出及控制特性,且由于模型系针对电力系统能量关系的分析研究而建,相较于现有光伏发电并网模型具备仿真速度快的优势,弥补了现存模型存在的缺点,可以方便地融合到以相量分析方法为基础的电力系统运行及控制特性相关研究中。

  1. Solar PV Lighting and Studying after Sunset: Analysis of Micro-benefits in Off-grid Rural Ghana

    Directory of Open Access Journals (Sweden)

    G.Y. Obeng

    2013-02-01

    Full Text Available Solar PV light provides school children living in off-grid rural communities theopportunity to have clean and bright lighting to study after sunset. On the contrary, lightingprovided from poor sources can pollute and adversely affect human eyes during reading andwriting. Using indicator-based questionnaires in cross-sectional surveys, households with andwithout solar PV lighting were surveyed in off-grid rural communities in Ghana. The studyinvestigated lighting and children’s studies after sunset. The results indicated that whereassolar PV light of 5-20 watts dc lamps was sufficient for 5-6 children to study together, lightingfrom kerosene lantern could be sufficient for 1-3 children. All things being equal, the resultsshowed that children who use solar PV light to study upto 2 hours after sunset are likely toimprove on their examination results. The extent to which solar PV lighting significantlyimpacts on studying after sunset was established using some identified indicators. Knowledgeof the results provides understanding of the relative constraints in lighting services faced bychildren in rural communities without access to quality lighting. Such micro-level data willhelp to enhance policy and planning efforts to increase access to clean and renewable energybasedlighting devices to achieve efficient visual comfort in off-grid rural communities.

  2. Visual Analytics for Power Grid Contingency Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Wong, Pak C.; Huang, Zhenyu; Chen, Yousu; Mackey, Patrick S.; Jin, Shuangshuang

    2014-01-20

    Contingency analysis is the process of employing different measures to model scenarios, analyze them, and then derive the best response to remove the threats. This application paper focuses on a class of contingency analysis problems found in the power grid management system. A power grid is a geographically distributed interconnected transmission network that transmits and delivers electricity from generators to end users. The power grid contingency analysis problem is increasingly important because of both the growing size of the underlying raw data that need to be analyzed and the urgency to deliver working solutions in an aggressive timeframe. Failure to do so may bring significant financial, economic, and security impacts to all parties involved and the society at large. The paper presents a scalable visual analytics pipeline that transforms about 100 million contingency scenarios to a manageable size and form for grid operators to examine different scenarios and come up with preventive or mitigation strategies to address the problems in a predictive and timely manner. Great attention is given to the computational scalability, information scalability, visual scalability, and display scalability issues surrounding the data analytics pipeline. Most of the large-scale computation requirements of our work are conducted on a Cray XMT multi-threaded parallel computer. The paper demonstrates a number of examples using western North American power grid models and data.

  3. A Single-Phase Transformerless Inverter With Charge Pump Circuit Concept for Grid-Tied PV Applications

    DEFF Research Database (Denmark)

    Ardashir, Jaber Fallah; Sabahi, Mehran; Hosseini, Seyed Hossein

    2017-01-01

    resonant control strategy is used to control the injected current. The main benefits of the proposed inverter are: the neutral of the grid is directly connected to the negative terminal of the PV panel, so the leakage current is eliminated; its compact size; low cost; the used dc voltage of the proposed...

  4. Accurate and Less-Disturbing Active Anti-Islanding Method based on PLL for Grid-Connected PV Inverters

    DEFF Research Database (Denmark)

    Ciobotaru, Mihai; Agelidis, Vassilios; Teodorescu, Remus

    2008-01-01

    Islanding prediction is a necessary feature of inverter-based photovoltaic (PV) system in order to meet stringent standard requirements for interconnection with the electrical grid. Both passive and active anti-islanding methods exist. Typically, active methods modify a given parameter, which also...

  5. FPGA Based Sinusoidal Pulse Width Modulated Waveform Generation for Solar (PV) Rural Home Power Inverter

    CERN Document Server

    Singh, S N

    2010-01-01

    With the increasing concern about global environmental protection and energy demand due to rapid growth of population in developing countries and the diminishing trend of resources of conventional grid supply, the need to produce freely available pollution free natural energy such as solar/wind energy has been drawing increasing interest in every corner of the world. In an effort to utilize these energies effectively through Power converter, a great deal of research is being carried out by different researchers / scientist and engineers at different places in the world to meet the increasing demand of load. The study presents methodology to integrate solar (PV) energy (which is freely available in every corner of the world) with grid source and supplement the existing grid power in rural houses during its cut off or restricted supply period. In order to get consistency in supply a DG is also added as a standby source in the proposed integration of network. The software using novel Direct PWM modulation strate...

  6. A Three Phase Multi Level Converter For grid Connected PV System

    Directory of Open Access Journals (Sweden)

    S. Srikanth

    2014-07-01

    Full Text Available Photovoltaic energy is a wide kind of green energy. A high performance on these systems is needed to make the most of energy produced by solar cells. Also, there must be a constant adaptation due to the continuous variation of power production. Control techniques for Power Converters like the MPPT algorithm (Maximum Power Point Tracking present very good results on photovoltaic chains. Nevertheless, losses on power elements reduce global performance and the voltage/current adaptation is not always possible.  This paper presents a single-phase 11-level (5 H-bridges cascade multilevel DC-AC grid-tied inverter. Each inverter bridge is connected to a 200 W solar panel. OPAL-RT lab was used as the hardware in the loop (HIL real-time control system platform where a Maximum Power Point Tracking (MPPT algorithm was implemented based on the inverter output power to assure optimal operation of the inverter when connected to the power grid as well as a Phase Locked Loop (PLL for phase and frequency match. A novel SPWM scheme is proposed in this paper to be used with the solar panels that can account for voltage profile fluctuations among the panels during the day. Simulation and experimental results are shown for voltage and current during synchronization mode and power transferring mode to validate the methodology for grid connection of renewable resources.

  7. On the Impact of Partial Shading on PV Output Power

    DEFF Research Database (Denmark)

    Sera, Dezso; Baghzouz, Yahia

    2008-01-01

    clarifies the mechanism of partial PV shading on a number of PV cells connected in series and/or parallel with and without bypass diodes. The analysis is presented in simple terms and can be useful to someone who wishes to determine the impact of some shading geometry on a PV system. The analysis...... is illustrated by measurements on a commercial 70 W panel, and a 14.4 kW PV array....

  8. Integration of Behind-the-Meter PV Fleet Forecasts into Utility Grid System Operations

    Energy Technology Data Exchange (ETDEWEB)

    Hoff, Thomas Hoff [Clean Power Research, L.L.C., Napa, CA (United States); Kankiewicz, Adam [Clean Power Research, L.L.C., Napa, CA (United States)

    2016-02-26

    Four major research objectives were completed over the course of this study. Three of the objectives were to evaluate three, new, state-of-the-art solar irradiance forecasting models. The fourth objective was to improve the California Independent System Operator’s (ISO) load forecasts by integrating behind-the-meter (BTM) PV forecasts. The three, new, state-of-the-art solar irradiance forecasting models included: the infrared (IR) satellite-based cloud motion vector (CMV) model; the WRF-SolarCA model and variants; and the Optimized Deep Machine Learning (ODML)-training model. The first two forecasting models targeted known weaknesses in current operational solar forecasts. They were benchmarked against existing operational numerical weather prediction (NWP) forecasts, visible satellite CMV forecasts, and measured PV plant power production. IR CMV, WRF-SolarCA, and ODML-training forecasting models all improved the forecast to a significant degree. Improvements varied depending on time of day, cloudiness index, and geographic location. The fourth objective was to demonstrate that the California ISO’s load forecasts could be improved by integrating BTM PV forecasts. This objective represented the project’s most exciting and applicable gains. Operational BTM forecasts consisting of 200,000+ individual rooftop PV forecasts were delivered into the California ISO’s real-time automated load forecasting (ALFS) environment. They were then evaluated side-by-side with operational load forecasts with no BTM-treatment. Overall, ALFS-BTM day-ahead (DA) forecasts performed better than baseline ALFS forecasts when compared to actual load data. Specifically, ALFS-BTM DA forecasts were observed to have the largest reduction of error during the afternoon on cloudy days. Shorter term 30 minute-ahead ALFS-BTM forecasts were shown to have less error under all sky conditions, especially during the morning time periods when traditional load forecasts often experience their largest

  9. A network approach for power grid robustness against cascading failures

    NARCIS (Netherlands)

    Wang, X.; Koc, Y.; Kooij, R.E.; Van Mieghem, P.

    2015-01-01

    Cascading failures are one of the main reasons for blackouts in electrical power grids. Stable power supply requires a robust design of the power grid topology. Currently, the impact of the grid structure on the grid robustness is mainly assessed by purely topological metrics, that fail to capture t

  10. Sizing and Simulation of PV-Wind Hybrid Power System

    Directory of Open Access Journals (Sweden)

    Mustafa Engin

    2013-01-01

    Full Text Available A sizing procedure is developed for hybrid system with the aid of mathematical models for photovoltaic cell, wind turbine, and battery that are readily present in the literature. This sizing procedure can simulate the annual performance of different kinds of photovoltaic-wind hybrid power system structures for an identified set of renewable resources, which fulfills technical limitations with the lowest energy cost. The output of the program will display the performance of the system during the year, the total cost of the system, and the best size for the PV-generator, wind generator, and battery capacity. Security lightning application is selected, whereas system performance data and environmental operating conditions are measured and stored. This hybrid system, which includes a PV, wind turbine, inverter, and a battery, was installed to supply energy to 24 W lamps, considering that the renewable energy resources of this site where the system was installed were 1700 Wh/m2/day solar radiation and 3.43 m/s yearly average wind speed. Using the measured variables, the inverter and charge regulator efficiencies were calculated as 90% and 98%, respectively, and the overall system’s electrical efficiency is calculated as 72%. Life cycle costs per kWh are found to be $0.89 and LLP = 0.0428.

  11. Platform computing powers enterprise grid

    CERN Multimedia

    2002-01-01

    Platform Computing, today announced that the Stanford Linear Accelerator Center is using Platform LSF 5, to carry out groundbreaking research into the origins of the universe. Platform LSF 5 will deliver the mammoth computing power that SLAC's Linear Accelerator needs to process the data associated with intense high-energy physics research (1 page).

  12. Analysis of off-grid hybrid wind turbine/solar PV water pumping systems

    Science.gov (United States)

    While many remote water pumping systems exist (e.g. mechanical windmills, solar photovoltaic , wind-electric, diesel powered), very few combine both the wind and solar energy resources to possibly improve the reliability and the performance of the system. In this paper, off-grid wind turbine (WT) a...

  13. Remote and Centralized Monitoring of PV Power Plants

    DEFF Research Database (Denmark)

    Kopacz, Csaba; Spataru, Sergiu; Sera, Dezso

    2014-01-01

    the inverters within each PV plant. The monitoring software stores the PV measurements in a data warehouse optimized for managing and data mining large amounts of data, from where it can be later visualized, analyzed and exported. By combining PV production measurements data with I-V curve measurements......This paper presents the concept and operating principles of a low-cost and flexible monitoring system for PV plants. Compared to classical solutions which can require dedicated hardware and/or specialized data logging systems, the monitoring system we propose allows parallel monitoring of PV plants...

  14. Why Do Electricity Policy and Competitive Markets Fail to Use Advanced PV Systems to Improve Distribution Power Quality?

    Directory of Open Access Journals (Sweden)

    Mark P. McHenry

    2016-01-01

    Full Text Available The increasing pressure for network operators to meet distribution network power quality standards with increasing peak loads, renewable energy targets, and advances in automated distributed power electronics and communications is forcing policy-makers to understand new means to distribute costs and benefits within electricity markets. Discussions surrounding how distributed generation (DG exhibits active voltage regulation and power factor/reactive power control and other power quality capabilities are complicated by uncertainties of baseline local distribution network power quality and to whom and how costs and benefits of improved electricity infrastructure will be allocated. DG providing ancillary services that dynamically respond to the network characteristics could lead to major network improvements. With proper market structures renewable energy systems could greatly improve power quality on distribution systems with nearly no additional cost to the grid operators. Renewable DG does have variability challenges, though this issue can be overcome with energy storage, forecasting, and advanced inverter functionality. This paper presents real data from a large-scale grid-connected PV array with large-scale storage and explores effective mitigation measures for PV system variability. We discuss useful inverter technical knowledge for policy-makers to mitigate ongoing inflation of electricity network tariff components by new DG interconnection requirements or electricity markets which value power quality and control.

  15. Grid-connected photovoltaic power systems: survey of inverter and related protection equipments

    Energy Technology Data Exchange (ETDEWEB)

    Ishikawa, T

    2002-12-15

    This report for the International Energy Agency (IEA) made by Task 5 of the Photovoltaic Power Systems (PVPS) programme reports on a survey made on inverter and related protection equipment. The mission of the Photovoltaic Power Systems Programme is to enhance the international collaboration efforts which accelerate the development and deployment of photovoltaic solar energy. Task 5 deals with issues concerning grid-interconnection and distributed PV power systems. This report summarises the data obtained from survey of recent inverter technology and inverter protection equipment for grid interconnected PV systems. The results are based on the surveys using a questionnaire to identify the current status of grid-interconnection inverters. This report is to serve as a reference for those interested in installing grid-connected PV systems, electric utility company personnel, manufacturers and researchers. The results of the survey are presented and discussed. Technical and financial data is reviewed and two appendices provide details on the results obtained and those institutions involved in the survey.

  16. Power Grid Defense Against Malicious Cascading Failure

    CERN Document Server

    Shakarian, Paulo; Lindelauf, Roy

    2014-01-01

    An adversary looking to disrupt a power grid may look to target certain substations and sources of power generation to initiate a cascading failure that maximizes the number of customers without electricity. This is particularly an important concern when the enemy has the capability to launch cyber-attacks as practical concerns (i.e. avoiding disruption of service, presence of legacy systems, etc.) may hinder security. Hence, a defender can harden the security posture at certain power stations but may lack the time and resources to do this for the entire power grid. We model a power grid as a graph and introduce the cascading failure game in which both the defender and attacker choose a subset of power stations such as to minimize (maximize) the number of consumers having access to producers of power. We formalize problems for identifying both mixed and deterministic strategies for both players, prove complexity results under a variety of different scenarios, identify tractable cases, and develop algorithms f...

  17. Superconductors in the power grid materials and applications

    CERN Document Server

    2015-01-01

    Superconductors offer high throughput with low electric losses and have the potential to transform the electric power grid. Transmission networks incorporating cables of this type could, for example, deliver more power and enable substantial energy savings. Superconductors in the Power Grid: Materials and Applications provides an overview of superconductors and their applications in power grids. Sections address the design and engineering of cable systems and fault current limiters and other emerging applications for superconductors in the power grid, as well as case studies of industrial applications of superconductors in the power grid. Expert editor from highly respected US government-funded research centre Unique focus on superconductors in the power grid Comprehensive coverage

  18. Performance and Feasibility Analysis of a Grid Interactive Large Scale Wind/PV Hybrid System based on Smart Grid Methodology Case Study South Part – Jordan

    Directory of Open Access Journals (Sweden)

    Qais H. Alsafasfeh

    2015-02-01

    Full Text Available Most recent research on renewable energy resources main one goal to make Jordan less dependent on imported energy with locally developed and produced solar power, this paper discussed the efficient system of Wind/ PV Hybrid System to be than main power sources for south part of Jordan, the proposed hybrid system design based on Smart Grid Methodology,  the solar energy will be installed on top roof of  electricity subscribers across the Governorate of Maan, Tafila, Karak and Aqaba and the wind energy will set in one site by this way the capital cost for project will be reduced also the  simulation result show   the feasibility  is a very competitive and feasible cost . Economics analysis of a proposed renewable energy system was made using HOMER simulation and evaluation was completed with the cost per kilowatt of EDCO company, the net present cost is $2,551,676,416, the cost of energy is 0.07kWhr with a renewable fraction of 86.6 %.

  19. Transient Oscillations Analysis and Modified Control Strategy for Seamless Mode Transfer in Micro-Grids: A Wind-PV-ES Hybrid System Case Study

    Directory of Open Access Journals (Sweden)

    Tengfei Zhang

    2015-12-01

    Full Text Available With the rapid development of the micro-grid associated with new and clean energies, the smooth switching between grid-connected and islanded operation modes of the micro-grid is a key issue that needs to be addressed urgently. In traditional solutions, V/f (Voltage/frequency control is adopted for the master micro sources when the micro-grid works in islanded mode, while PQ (real and reactive power control is adopted when in grid-connected mode. However, when the two controllers switch when mode transfer occurs, transient oscillations usually occur and thereafter the dynamic response will be degraded. This paper considers an archetypical micro-grid with Wind-PV-ES (Wind, Photovoltaic and Energy Storage hybrid system, which forms the basis of our case study. The underlying reason for such transient oscillation is analyzed in this paper. Thereafter a modified control strategy for seamless mode transfer is designed and implemented. An improved PQ control method is designed by which the output of the PQ controller always synchronously tracks the output of the V/f controller for micro-grid switches from islanded mode to grid-connected; furthermore, a dq rotating coordinate synchronization based V/f control method is proposed for transition from grid-connected mode to islanded mode. Finally, experiments and analysis are undertaken on some basic and important operating cases; the results in our case study indicate that the modified control strategy is effective in dominating the micro-grid during mode transfer and thus yielding significantly better performances.

  20. Power systems signal processing for smart grids

    CERN Document Server

    Ribeiro, Paulo Fernando; Ribeiro, Paulo Márcio; Cerqueira, Augusto Santiago

    2013-01-01

    With special relation to smart grids, this book provides clear and comprehensive explanation of how Digital Signal Processing (DSP) and Computational Intelligence (CI) techniques can be applied to solve problems in the power system. Its unique coverage bridges the gap between DSP, electrical power and energy engineering systems, showing many different techniques applied to typical and expected system conditions with practical power system examples. Surveying all recent advances on DSP for power systems, this book enables engineers and researchers to understand the current state of the art a

  1. Future of Grid-Tied PV Business Models: What Will Happen When PV Penetration on the Distribution Grid is Significant? Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Graham, S.; Katofsky, R.; Frantzis, L.; Sawyer, H.; Margolis, R.

    2008-05-01

    Eventually, distributed PV will become a more significant part of the generation mix. When this happens, it is expected that utilities will have to take on a more active role in the placement, operation and control of these systems. There are operational complexities and concerns of revenue erosion that will drive utilities into greater involvement of distributed PV and will create new business models. This report summarizes work done by Navigant Consulting Inc. for the National Renewable Energy Laboratory as part of the Department of Energy's work on Renewable System Integration. The objective of the work was to better understand the structure of these future business models and the research, development and demonstration (RD&D) required to support their deployment. This report describes potential future PV business models in terms of combinations of utility ownership and control of the PV assets, and the various relationships between end-users and third-party owners.

  2. Market aspects of smart power grids development

    Directory of Open Access Journals (Sweden)

    Maciej Makowski

    2012-03-01

    Full Text Available Smart Grids herald a revolution in the power sector. The centralized and passive power grid model known for over a century is before our very eyes assuming a completely brand new shape: of an active and dynamic network with an increasingly relevant role of consumers – prosumers, who are offered brand new products and services. Such an active development is possible due to a number of factors, such as: 1. Synergy of ICT with power engineering – these disciplines are becoming an indispensable element of the modern power grid’s operation, 2. The European Union’s regulations in the area of reduction of CO2 emission and improved energy efficiency, as well as identification of Smart Grids as one of the optimum tools, 3. Growth, thanks to continuously increasing expenditures, public awareness of the purchase and rational use of energy. However, the Smart Grid development and ICT implementation in the power sector also carry a risk in the matter of setting up system and process links between the systems of concerned energy market players, which should be mitigated by development of technical standards, methods and principles of good cooperation between the concerned parties. Mitigation of the risk, and as a consequence, effective Smart Grids development will provide conditions for dynamic development of new roles and mechanisms on the energy market. Offering modern products and services to consumers and prosumers, and effective implementation on a national scale of demand management mechanisms will be a source of multidimensional benefits of a functional and financial nature, and will also have a positive impact on the National Lower Grid’s security.

  3. Five "Mainstays" of Power Grid Innovation

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ It is an important reason for Microsoft, Bell and General Electric etc dominating always on forward position in world's science and technologies to bring full play to autonomous innovative capability of enterprises' research and development center. In the Power Grid Science and Technology Working Conference 2006, Mr. Lu Qizhou, the vice president of the State Grid Corporation(SG) pointed out that during the 11th Five-Year Plan period, the SG will emphatically push forward optimal conformity on scientific and technological resources among its affiliated research institutes, tap their back bone and leading effects in technical innovation system.

  4. Sustainable Data Evolution Technology for Power Grid Optimization

    Energy Technology Data Exchange (ETDEWEB)

    2017-10-09

    The SDET Tool is used to create open-access power grid data sets and facilitate updates of these data sets by the community. Pacific Northwest National Laboratory (PNNL) and its power industry and software vendor partners are developing an innovative sustainable data evolution technology (SDET) to create open-access power grid datasets and facilitate updates to these datasets by the power grid community. The objective is to make this a sustained effort within and beyond the ARPA-E GRID DATA program so that the datasets can evolve over time and meet the current and future needs for power grid optimization and potentially other applications in power grid operation and planning.

  5. Lifetime Evaluation of Grid-Connected PV Inverters Considering Panel Degradation Rates and Installation Sites

    DEFF Research Database (Denmark)

    Sangwongwanich, Ariya; Yang, Yongheng; Sera, Dezso

    2017-01-01

    Lifetime of PV inverters is affected by the installation sites related to different solar irradiance and ambient temperature profiles (also referred to as mission profiles). In fact, the installation site also affects the degradation rate of the PV panels, and thus long-term energy production...... and reliability. Prior-art lifetime analysis in PV inverters has not yet investigated the impact of PV panel degradations. This paper thus evaluates the lifetime of PV inverters considering panel degradation rates and mission profiles. Evaluations have been carried out on PV systems installed in Denmark...

  6. Exact Power Constraints in Smart Grid Control

    DEFF Research Database (Denmark)

    Trangbæk, K; Petersen, Mette Højgaard; Bendtsen, Jan Dimon

    2011-01-01

    This paper deals with hierarchical model predictive control (MPC) of smart grid systems. The objective is to accommodate load variations on the grid, arising from varying consumption and natural variations in the power production e.g. from wind turbines. This balancing between supply and demand...... is performed by distributing power to consumers in an optimal manner, subject to the requirement that each consumer receives the specific amount of energy the consumer is entitled to within a specific time horizon. However, in order to do so, the high-level controller requires knowledge of how much energy...... consumer models. The example illustrates that the exact bounds computed by the proposed method leads to a better power distribution than a conventional, conservative approach in case of fast changes in the load....

  7. Cybersecurity Awareness in the Power Grid

    Energy Technology Data Exchange (ETDEWEB)

    Scholtz, Jean; Franklin, Lyndsey; Le Blanc, Katya L.; Andersen, Eric S.

    2016-07-10

    We report on a series of interviews and observations conducted with control room dispatchers in a bulk electrical system. These dispatchers must react quickly to incidents as they happen in order to ensure the reliability and safe operation of the power grid. They do not have the time to evaluate incidents for signs of cyber-attack as part of their initial response. Cyber-attack detection involves multiple personnel from a variety of roles at both local and regional levels. Smart grid technology will improve detection and defense capabilities of the future grid, however, the current infrastructure remains a mixture of old and new equipment which will continue to operate for some time. Thus, research still needs to focus on strategies for the detection of malicious activity on current infrastructure as well as protection and remediation.

  8. A Stationary Reference Frame Grid Synchronization System for Three-Phase Grid-Connected Power Converters Under Adverse Grid Conditions

    DEFF Research Database (Denmark)

    Rodríguez, P.; Luna, A.; Muñoz-Aguilar, R. S.

    2012-01-01

    Grid synchronization algorithms are of great importance in the control of grid-connected power converters, as fast and accurate detection of the grid voltage parameters is crucial in order to implement stable control strategies under generic grid conditions. This paper presents a new grid...... of the instantaneous symmetrical components of the grid voltage under unbalanced and distorted grid conditions. This paper analyzes the performance of the proposed synchronization method including different design issues. Moreover, the behavior of the method for synchronizing with highly unbalanced grid is proven...

  9. Residential PV-Energy Storage Testing Collaboration with SunPower: Cooperative Research and Development Final Report, CRADA Number CRD-14-569

    Energy Technology Data Exchange (ETDEWEB)

    Lundstrom, Blake [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-11-01

    Residential scale energy storage devices have shown great promise to add value and improve the ability to integrate distributed and variable generation into the distribution grid. Battery energy storage systems combined with PV and advanced inverters can provide many services. These include extended backup power in case of grid failure, reductions in feeder and system level peak load, system level net load ramp reduction, grid management services both locally (e.g., voltage management) and bulk system (e.g., reserves) level, and improved grid reliability through grid voltage and frequency support. Even though the cost of the energy storage systems are decreasing, one of the main challenges related to the widespread deployment of energy storage, as found by the U.S. Department of Energy (DOE), is utility acceptance of storage technologies. Various interconnection challenges exist when connecting distributed PV-energy storage into the electrical distribution grid in terms of safety, reliability and stability of the electric power systems. Some of the urgent challenges, as seen by the manufacturers and installers are: safety of the battery cells and the packs, performance of the power conversion systems, effect of bidirectional power flow on existing utility equipment and qualification of solutions such as volt-ampere reactive (VAR) support and frequency regulation. Under this project, National Renewable Energy Laboratory (NREL) researchers will work with SunPower to address these challenges by research, testing and analysis at Energy System Integration Facility (ESIF) and energy storage testing laboratory at NREL. NREL's unique power hardware-in-the-loop (PHIL) capability will be utilized to evaluate system-level issues such as reverse power flow and VAR support (if available) for these PV-energy storage systems. Through the analysis of test results, the proposed project will demonstrate use of ESIF capabilities in a way that advances both the DOE and SunPower

  10. Analysis of Energy Storage Technology Applied in Grid-Connected PV System%储能技术在光伏并网发电系统中的应用分析

    Institute of Scientific and Technical Information of China (English)

    刘建涛; 张建成; 马杰; 曹雷

    2011-01-01

    In line with the structural features of the grid-connected PV power system, this paper explores the adverse impacts of the system on the grid if without the energy storage device. From perspective of both the electricity customer and the grid operator, the paper proposes several technologies of energy storage system applied in the grid-connected PV Power system. Finally, it puts forward development needs for the storage technology applied in the grid -connected PV Power system.%根据光伏并网发电系统的结构特点分析了不加储能装置的光伏并网发电系统对电网造成的不良影响,并分别从电网角度和用户角度提出了储能系统在光伏并网发电系统中的几种应用技术,最后提出了用于光伏并网发电系统的储能技术发展需求.

  11. Power system SCADA and smart grids

    CERN Document Server

    Thomas, Mini S

    2015-01-01

    Power System SCADA and Smart Grids brings together in one concise volume the fundamentals and possible application functions of power system supervisory control and data acquisition (SCADA). The text begins by providing an overview of SCADA systems, evolution, and use in power systems and the data acquisition process. It then describes the components of SCADA systems, from the legacy remote terminal units (RTUs) to the latest intelligent electronic devices (IEDs), data concentrators, and master stations, as well as:Examines the building and practical implementation of different SCADA systemsOf

  12. Two-loop controller for maximizing performance of a grid-connected photovoltaic - fuel cell hybrid power plant

    Science.gov (United States)

    Ro, Kyoungsoo

    The study started with the requirement that a photovoltaic (PV) power source should be integrated with other supplementary power sources whether it operates in a stand-alone or grid-connected mode. First, fuel cells for a backup of varying PV power were compared in detail with batteries and were found to have more operational benefits. Next, maximizing performance of a grid-connected PV-fuel cell hybrid system by use of a two-loop controller was discussed. One loop is a neural network controller for maximum power point tracking, which extracts maximum available solar power from PV arrays under varying conditions of insolation, temperature, and system load. A real/reactive power controller (RRPC) is the other loop. The RRPC meets the system's requirement for real and reactive powers by controlling incoming fuel to fuel cell stacks as well as switching control signals to a power conditioning subsystem. The RRPC is able to achieve more versatile control of real/reactive powers than the conventional power sources since the hybrid power plant does not contain any rotating mass. Results of time-domain simulations prove not only effectiveness of the proposed computer models of the two-loop controller, but also their applicability for use in transient stability analysis of the hybrid power plant. Finally, environmental evaluation of the proposed hybrid plant was made in terms of plant's land requirement and lifetime COsb2 emissions, and then compared with that of the conventional fossil-fuel power generating forms.

  13. Quantifying Power Grid Risk from Geomagnetic Storms

    Science.gov (United States)

    Homeier, N.; Wei, L. H.; Gannon, J. L.

    2012-12-01

    We are creating a statistical model of the geophysical environment that can be used to quantify the geomagnetic storm hazard to power grid infrastructure. Our model is developed using a database of surface electric fields for the continental United States during a set of historical geomagnetic storms. These electric fields are derived from the SUPERMAG compilation of worldwide magnetometer data and surface impedances from the United States Geological Survey. This electric field data can be combined with a power grid model to determine GICs per node and reactive MVARs at each minute during a storm. Using publicly available substation locations, we derive relative risk maps by location by combining magnetic latitude and ground conductivity. We also estimate the surface electric fields during the August 1972 geomagnetic storm that caused a telephone cable outage across the middle of the United States. This event produced the largest surface electric fields in the continental U.S. in at least the past 40 years.

  14. Grid-Competitive Residential and Commercial Fully Automated PV Systems Technology: Final technical Report, August 2011

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Katie E.; Cousins, Peter; Culligan, Matt; Jonathan Botkin; DeGraaff, David; Bunea, Gabriella; Rose, Douglas; Bourne, Ben; Koehler, Oliver

    2011-08-26

    Under DOE's Technology Pathway Partnership program, SunPower Corporation developed turn-key, high-efficiency residential and commercial systems that are cost effective. Key program objectives include a reduction in LCOE values to 9-12 cents/kWh and 13-18 cents/kWh respectively for the commercial and residential markets. Target LCOE values for the commercial ground, commercial roof, and residential markets are 10, 11, and 13 cents/kWh. For this effort, SunPower collaborated with a variety of suppliers and partners to complete the tasks below. Subcontractors included: Solaicx, SiGen, Ribbon Technology, Dow Corning, Xantrex, Tigo Energy, and Solar Bridge. SunPower's TPP addressed nearly the complete PV value chain: from ingot growth through system deployment. Throughout the award period of performance, SunPower has made progress toward achieving these reduced costs through the development of 20%+ efficient modules, increased cell efficiency through the understanding of loss mechanisms and improved manufacturing technologies, novel module development, automated design tools and techniques, and reduced system development and installation time. Based on an LCOE assessment using NREL's Solar Advisor Model, SunPower achieved the 2010 target range, as well as progress toward 2015 targets.

  15. Development of PV powered consumer products using future scenarios

    NARCIS (Netherlands)

    Reinders, A.H.M.E.; Meulen, van der B.J.R.; Eger, A.O.

    2006-01-01

    Given the high potential of PV technology to reduce the environmental impact of electricity use of consumer products, it would be worthwhile to advance the application of PV systems in mass produced products. To date this field of application has been explored only to a limited extent. For this reas

  16. Examining System-Wide Impacts of Solar PV Control Systems with a Power Hardware-in-the-Loop Platform

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Tess L.; Fuller, Jason C.; Schneider, Kevin P.; Palmintier, Bryan; Lundstrom, Blake; Chakraborty, Sudipta

    2014-06-08

    High penetration levels of distributed solar PV power generation can lead to adverse power quality impacts, such as excessive voltage rise, voltage flicker, and reactive power values that result in unacceptable voltage levels. Advanced inverter control schemes have been developed that have the potential to mitigate many power quality concerns. However, local closed-loop control may lead to unintended behavior in deployed systems as complex interactions can occur between numerous operating devices. To enable the study of the performance of advanced control schemes in a detailed distribution system environment, a test platform has been developed that integrates Power Hardware-in-the-Loop (PHIL) with concurrent time-series electric distribution system simulation. In the test platform, GridLAB-D, a distribution system simulation tool, runs a detailed simulation of a distribution feeder in real-time mode at the Pacific Northwest National Laboratory (PNNL) and supplies power system parameters at a point of common coupling. At the National Renewable Energy Laboratory (NREL), a hardware inverter interacts with grid and PV simulators emulating an operational distribution system. Power output from the inverters is measured and sent to PNNL to update the real-time distribution system simulation. The platform is described and initial test cases are presented. The platform is used to study the system-wide impacts and the interactions of inverter control modes—constant power factor and active Volt/VAr control—when integrated into a simulated IEEE 8500-node test feeder. We demonstrate that this platform is well-suited to the study of advanced inverter controls and their impacts on the power quality of a distribution feeder. Additionally, results are used to validate GridLAB-D simulations of advanced inverter controls.

  17. Basic study on dynamic reactive-power control method with PV output prediction for solar inverter

    Directory of Open Access Journals (Sweden)

    Ryunosuke Miyoshi

    2016-01-01

    Full Text Available To effectively utilize a photovoltaic (PV system, reactive-power control methods for solar inverters have been considered. Among the various methods, the constant-voltage control outputs less reactive power compared with the other methods. We have developed a constant-voltage control to reduce the reactive-power output. However, the developed constant-voltage control still outputs unnecessary reactive power because the control parameter is constant in every waveform of the PV output. To reduce the reactive-power output, we propose a dynamic reactive-power control method with a PV output prediction. In the proposed method, the control parameter is varied according to the properties of the predicted PV waveform. In this study, we performed numerical simulations using a distribution system model, and we confirmed that the proposed method reduces the reactive-power output within the voltage constraint.

  18. Features of a fully renewable US electricity system: Optimized mixes of wind and solar PV and transmission grid extensions

    CERN Document Server

    Becker, Sarah; Andresen, Gorm B; Zeyer, Timo; Schramm, Stefan; Greiner, Martin; Jacobson, Mark Z

    2014-01-01

    Wind and solar PV generation data for the entire contiguous US are calculated, on the basis of 32 years of weather data with temporal resolution of one hour and spatial resolution of 40x40km$^2$, assuming site-suitability-based as well as stochastic wind and solar PV capacity distributions throughout the country. These data are used to investigate a fully renewable electricity system, resting primarily upon wind and solar PV power. We find that the seasonal optimal mix of wind and solar PV comes at around 80% solar PV share, owing to the US summer load peak. By picking this mix, long-term storage requirements can be more than halved compared to a wind only mix. The daily optimal mix lies at about 80% wind share due to the nightly gap in solar PV production. Picking this mix instead of solar only reduces backup energy needs by about 50%. Furthermore, we calculate shifts in FERC (Federal Energy Regulatory Commission)-level LCOE (Levelized Costs Of Electricity) for wind and solar PV due to their differing resour...

  19. Assessment of Air-Pollution Control Policy’s Impact on China’s PV Power: A System Dynamics Analysis

    OpenAIRE

    Xiaodan Guo; Dongxiao Niu; Bowen Xiao

    2016-01-01

    Recently, China has brought out several air-pollution control policies, which indicate the prominent position that PV power hold in improving atmosphere environment. Under this policy environment, the development of China’s PV power will be greatly affected. Firstly, after analyzing the influencing path of air-pollution control policies on PV power, this paper built a system dynamics model, which can be used as a platform for predicting China’s PV power development in every policy scenario du...

  20. Examining System-Wide Impacts of Solar PV Control Systems with a Power Hardware-in-the-Loop Platform

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Tess L.; Fuller, Jason C.; Schneider, Kevin P.; Palmintier, Bryan; Lundstrom, Blake; Chakraborty, Sudipta

    2014-10-11

    High penetration levels of distributed solar PV power generation can lead to adverse power quality impacts such as excessive voltage rise, voltage flicker, and reactive power values that result in unacceptable voltage levels. Advanced inverter control schemes have been proposed that have the potential to mitigate many power quality concerns. However, closed-loop control may lead to unintended behavior in deployed systems as complex interactions can occur between numerous operating devices. In order to enable the study of the performance of advanced control schemes in a detailed distribution system environment, a Hardware-in-the-Loop (HIL) platform has been developed. In the HIL system, GridLAB-D, a distribution system simulation tool, runs in real-time mode at the Pacific Northwest National Laboratory (PNNL) and supplies power system parameters at a point of common coupling to hardware located at the National Renewable Energy Laboratory (NREL). Hardware inverters interact with grid and PV simulators emulating an operational distribution system and power output from the inverters is measured and sent to PNNL to update the real-time distribution system simulation. The platform is described and initial test cases are presented. The platform is used to study the system-wide impacts and the interactions of controls applied to inverters that are integrated into a simulation of the IEEE 8500-node test feeder, with inverters in either constant power factor control or active volt/VAR control. We demonstrate that this HIL platform is well-suited to the study of advanced inverter controls and their impacts on the power quality of a distribution feeder. Additionally, the results from HIL are used to validate GridLAB-D simulations of advanced inverter controls.

  1. Analysis of typical world countries' wind power and PV industry policies and their enlightenment to China

    Science.gov (United States)

    Zeng, Ming; Yang, Lijun; Qiu, Hongji; Li, Yuanfei; Peng, Lilin

    2017-01-01

    The wind power and PV are the key fields of clean energy development in China in recent years. However, there are still many aspects of problems in wind power and PV industries at present, such as the insufficient consumptive ability and the limitation of market competition capability. The effective leading and support of government in the aspect of policies is especially needed in order to solve these problems. Based on the analysis of main policies system of wind power and PV in our country, Spain, the United Kingdom and Germany are chosen as typical countries because of their wind power and PV industries are relatively developed. Their policies of wind power and PV industries are studied respectively from five aspects, namely macroscopic laws, development planning, administrative policies, fiscal and tax policies and price policies. Then the comparison among typical countries and China is made and the exiting problems in China's policies of wind power and PV industries are summed up. Finally, the suggestions to promote China's wind power and PV industries development are presented.

  2. Smart charging of electric vehicles with photovoltaic power and vehicle-to-grid technology in a microgrid; a case study

    NARCIS (Netherlands)

    van der Kam, Mart; van Sark, Wilfried

    2015-01-01

    We present a model developed to study the increase of self-consumption of photovoltaic (PV) power by smart charging of electric vehicles (EVs) and vehicle-to-grid (V2G) technology. Whereas previous studies mostly use large EV fleets in their models, our focus is on a smaller scale. We apply the mode

  3. Analytical Investigation and Control System Set-up of Medium Scale PV Plants for Power Flow Management

    Directory of Open Access Journals (Sweden)

    Rosario Miceli

    2012-11-01

    Full Text Available In the field of photovoltaic (PV plants and energy conversion from renewable sources, a large part of the technical literature is more devoted to practical aspects (new solar cells, electrically driven PV panels, safety, reduction of parasitic currents, etc. than to theoretical investigations. Despite this tendency, this paper presents a mathematical analysis of a medium scale photovoltaic power generation system connected to the distribution network and of its control system. In such a system, the conversion stage is unique due to the absence of a boost chopper. The conducted analysis leads to the interesting conclusion that the inverter used in the plant presents two degrees of freedom, easy to exploit in a control system in which the inverter simultaneously realizes the interconnection to the grid and the MPPT control. The structure of the control system is then presented, discussed and validated by means of numerical simulations.

  4. Design of a Solar Tracker System for PV Power Plants

    Directory of Open Access Journals (Sweden)

    Tiberiu Tudorache

    2010-04-01

    Full Text Available This paper deals with the design and execution of a solar tracker systemdedicated to the PV conversion panels. The proposed single axis solar tracker deviceensures the optimization of the conversion of solar energy into electricity by properlyorienting the PV panel in accordance with the real position of the sun. The operation of theexperimental model of the device is based on a DC motor intelligently controlled by adedicated drive unit that moves a mini PV panel according to the signals received from twosimple but efficient light sensors. The performance and characteristics of the solar trackerare experimentally analyzed.

  5. Power Quality Analysis in Off-Grid Power Platform

    Directory of Open Access Journals (Sweden)

    Stanislav Misak

    2014-01-01

    Full Text Available Research projects in the field of electrical distribution systems are moving to a new philosophy of Smart Grids, where the effort is to use the maximum possible share of power from renewable energy potential. Under this philosophy the emphasis is on energy independence, reliability and safety of operation of energy distribution system. Research in this area leads for example to developing of autonomous local microgrids with the several specific requirements. However, the problem of parameters keeping of quality of electric energy can arise together with increased penetration of distributed generation in microgrids. This problem is caused by decreased short-circuit power of local renewable energy sources, stochastic supply of electric energy from renewable energy sources and operating of active distribution grid in autonomous mode without connection to the external distribution system. General introduction to the power quality evaluation in off-grid power system is introduced in this paper. Initial results from power quality analysis from small off-grids system is presented in this text too.

  6. Determining the maximum feasible amount of photovoltaics in the European transmission grid under optimal PV utilization

    Energy Technology Data Exchange (ETDEWEB)

    Cherevatskiy, Stanislav; Troester, Eckehard [Energynautics GmbH, Langen (Germany)

    2012-07-01

    In the past few years a significant growth of the number of photovoltaic (PV) systems has been observed worldwide and particularly in Europe. Increasing maturity of this technology and growing manufacturing capacities have led to a considerable decline in prices. Looking at a future possible development of installed PV capacities in Europe, the paper at hand investigates how well the available PV energy is made use of when the installed capacity of PV reaches nearly 2000 gigawatt-peak (GWp). A methodology is presented that aims at optimal placement of PV plants taking into consideration region-specific irradiation conditions in Europe and restrictions imposed by the transmission network. Additionally, a mehtod for optimized placement and dimensioning of storage systems along with their best possible operation strategy is applied for assessment of the effect on PV utilization. (orig.)

  7. Assessing the need for better forecasting and observability of pv

    DEFF Research Database (Denmark)

    Alet, Pierre-Jean; Efthymiou, Venizelos; Graditi, Giorgio

    2017-01-01

    In its review of the challenges and opportunities associated with massive deployment of solar PV generation, the Grid integration working group of the ETIP PV identified forecasting and observability as critical technologies for the planning and operation of the power system with large PV penetra...

  8. Status and Functions of Regional Power Grid Corporations

    Institute of Scientific and Technical Information of China (English)

    Wu Wei

    2007-01-01

    @@ In line with power institutional reform and formation of the state power grid, status and roles of regional power grid corporations experienced several variations and are now being incessantly marginalized and weakened. The reform of turning regional grid corporations into regional headquarters of State Grid Corporation may be a better choice beneficial to group operation, intensive development and precise management. This article can be regarded as the author's personal opinion.

  9. Design and operation of grid-interactive thin-film silicon PV systems

    Science.gov (United States)

    Marion, Bill; Atmaram, Gobind; Lashway, Clin; Strachan, John W.

    Results are described from the operation of 11 thin-film amorphous silicon photovoltaic systems at three test facilities: the Florida Solar Energy Center, the New Mexico Solar Energy Institute, and Sandia National Laboratories. Commercially available modules from four US manufacturers are used in these systems, with array sizes from 133 to 750 W peak. Measured array efficiencies are from 3.1 to 4.8 percent. Except for one manufacturer, array peak power is in agreement with the calculated design ratings. For certain grid-connected systems, nonoptimal operation exists because the array peak power voltage is below the lower voltage limit of the power conditioning system. Reliability problems are found in two manufacturers' modules when shorts to ground and terminal corrosion occur. Array leakage current data are presented.

  10. A fault diagnosis system for PV power station based on global partitioned gradually approximation method

    Science.gov (United States)

    Wang, S.; Zhang, X. N.; Gao, D. D.; Liu, H. X.; Ye, J.; Li, L. R.

    2016-08-01

    As the solar photovoltaic (PV) power is applied extensively, more attentions are paid to the maintenance and fault diagnosis of PV power plants. Based on analysis of the structure of PV power station, the global partitioned gradually approximation method is proposed as a fault diagnosis algorithm to determine and locate the fault of PV panels. The PV array is divided into 16x16 blocks and numbered. On the basis of modularly processing of the PV array, the current values of each block are analyzed. The mean current value of each block is used for calculating the fault weigh factor. The fault threshold is defined to determine the fault, and the shade is considered to reduce the probability of misjudgments. A fault diagnosis system is designed and implemented with LabVIEW. And it has some functions including the data realtime display, online check, statistics, real-time prediction and fault diagnosis. Through the data from PV plants, the algorithm is verified. The results show that the fault diagnosis results are accurate, and the system works well. The validity and the possibility of the system are verified by the results as well. The developed system will be benefit for the maintenance and management of large scale PV array.

  11. Millimeterwave Space Power Grid architecture development 2012

    Science.gov (United States)

    Komerath, Narayanan; Dessanti, Brendan; Shah, Shaan

    This is an update of the Space Power Grid architecture for space-based solar power with an improved design of the collector/converter link, the primary heater and the radiator of the active thermal control system. The Space Power Grid offers an evolutionary approach towards TeraWatt-level Space-based solar power. The use of millimeter wave frequencies (around 220GHz) and Low-Mid Earth Orbits shrinks the size of the space and ground infrastructure to manageable levels. In prior work we showed that using Brayton cycle conversion of solar power allows large economies of scale compared to the linear mass-power relationship of photovoltaic conversion. With high-temperature materials permitting 3600 K temperature in the primary heater, over 80 percent cycle efficiency was shown with a closed helium cycle for the 1GW converter satellite which formed the core element of the architecture. Work done since the last IEEE conference has shown that the use of waveguides incorporated into lighter-than-air antenna platforms, can overcome the difficulties in transmitting millimeter wave power through the moist, dense lower atmosphere. A graphene-based radiator design conservatively meets the mass budget for the waste heat rejection system needed for the compressor inlet temperature. Placing the ultralight Mirasol collectors in lower orbits overcomes the solar beam spot size problem of high-orbit collection. The architecture begins by establishing a power exchange with terrestrial renewable energy plants, creating an early revenue generation approach with low investment. The approach allows for technology development and demonstration of high power millimeter wave technology. A multinational experiment using the International Space Station and another power exchange satellite is proposed to gather required data and experience, thus reducing the technical and policy risks. The full-scale architecture deploys pairs of Mirasol sunlight collectors and Girasol 1 GW converter satellites t

  12. Power grid complex network evolutions for the smart grid

    NARCIS (Netherlands)

    Pagani, Giuliano Andrea; Aiello, Marco

    2014-01-01

    The shift towards an energy grid dominated by prosumers (consumers and producers of energy) will inevitably have repercussions on the electricity distribution infrastructure. Today the grid is a hierarchical one delivering energy from large scale facilities to end-users. Tomorrow it will be a capill

  13. Power grid complex network evolutions for the smart grid

    NARCIS (Netherlands)

    Pagani, Giuliano Andrea; Aiello, Marco

    2014-01-01

    The shift towards an energy grid dominated by prosumers (consumers and producers of energy) will inevitably have repercussions on the electricity distribution infrastructure. Today the grid is a hierarchical one delivering energy from large scale facilities to end-users. Tomorrow it will be a capill

  14. Economics of Wind Power when National Grids are Unreliable

    NARCIS (Netherlands)

    Kooten, van G.C.; Wong, L.

    2010-01-01

    Power interruptions are a typical characteristic of national grids in developing countries. Manufacturing, processing, refrigeration and other facilities that require a dependable supply of power, and might be considered a small grid within the larger national grid, employ diesel generators for back

  15. Characterization of high performance silicon-based VMJ PV cells for laser power transmission applications

    Science.gov (United States)

    Perales, Mico; Yang, Mei-huan; Wu, Cheng-liang; Hsu, Chin-wei; Chao, Wei-sheng; Chen, Kun-hsien; Zahuranec, Terry

    2016-03-01

    Continuing improvements in the cost and power of laser diodes have been critical in launching the emerging fields of power over fiber (PoF), and laser power beaming. Laser power is transmitted either over fiber (for PoF), or through free space (power beaming), and is converted to electricity by photovoltaic cells designed to efficiently convert the laser light. MH GoPower's vertical multi-junction (VMJ) PV cell, designed for high intensity photovoltaic applications, is fueling the emergence of this market, by enabling unparalleled photovoltaic receiver flexibility in voltage, cell size, and power output. Our research examined the use of the VMJ PV cell for laser power transmission applications. We fully characterized the performance of the VMJ PV cell under various laser conditions, including multiple near IR wavelengths and light intensities up to tens of watts per cm2. Results indicated VMJ PV cell efficiency over 40% for 9xx nm wavelengths, at laser power densities near 30 W/cm2. We also investigated the impact of the physical dimensions (length, width, and height) of the VMJ PV cell on its performance, showing similarly high performance across a wide range of cell dimensions. We then evaluated the VMJ PV cell performance within the power over fiber application, examining the cell's effectiveness in receiver packages that deliver target voltage, intensity, and power levels. By designing and characterizing multiple receivers, we illustrated techniques for packaging the VMJ PV cell for achieving high performance (> 30%), high power (> 185 W), and target voltages for power over fiber applications.

  16. A Voltage Regulation Strategy by Grid-Connected PV Inverters in Low-Voltage Networks%低压网络中并网光伏逆变器调压策略

    Institute of Scientific and Technical Information of China (English)

    周林; 晁阳; 廖波; 晁朋飞; 杨明

    2013-01-01

    为解决光伏接入电网引起的并网点电压越限问题,增大光伏在电网中的渗透率,可充分利用并网光伏逆变器的无功调压能力向电网提供无功支撑。为此,从电网电压降落角度研究光伏发电接入电网前后并网点电压的变化,并深入分析了德国电气工程师协会(Verband Deutscher Elektrotechniker)提出的无功功率控制策略,在此基础上,提出一种基于并网点电压幅值与光伏有功出力的 Q(U,P)无功功率控制策略。该控制策略继承了德国电气工程师协会提出的策略的优点,在此控制策略下,光伏系统所有逆变器参与电网电压调节,在维持电网电压在要求范围的前提下,无功吸收总量最低,电网有功、无功损耗最小。算例结果验证了该策略的有效性。%In allusion to out-of-limit voltage at grid-connected point caused by grid-connection of photovoltaic (PV) system and raising the penetration rate of PV system on power grid, it is possible to fully utilize the reactive power regulation ability of grid-connected PV inverter to provide reactive power support to power grid. For this purpose, in the viewpoint of voltage drop the voltage variation at grid-connected point before and after the grid-connection of PV system is researched, and the reactive power control strategy given by Verband Deutscher Elektrotechniker (VDE) is analyzed in depth. On this basis, a reactive power control strategy based on voltage amplitude at grid-connected point and active output of PV system is proposed. This control strategy inherits the advantages of reactive power control strategy given by VDE, and under the proposed control strategy all PV inverters participate power grid voltage regulation, and under the premise of maintaining the grid voltage within the specified range the total absorbed amount of reactive power is the lowest and the active and reactive loss of power grid are minimized. The validity of the

  17. Realworld maximum power point tracking simulation of PV system based on Fuzzy Logic control

    Science.gov (United States)

    Othman, Ahmed M.; El-arini, Mahdi M. M.; Ghitas, Ahmed; Fathy, Ahmed

    2012-12-01

    In the recent years, the solar energy becomes one of the most important alternative sources of electric energy, so it is important to improve the efficiency and reliability of the photovoltaic (PV) systems. Maximum power point tracking (MPPT) plays an important role in photovoltaic power systems because it maximize the power output from a PV system for a given set of conditions, and therefore maximize their array efficiency. This paper presents a maximum power point tracker (MPPT) using Fuzzy Logic theory for a PV system. The work is focused on the well known Perturb and Observe (P&O) algorithm and is compared to a designed fuzzy logic controller (FLC). The simulation work dealing with MPPT controller; a DC/DC Ćuk converter feeding a load is achieved. The results showed that the proposed Fuzzy Logic MPPT in the PV system is valid.

  18. Realworld maximum power point tracking simulation of PV system based on Fuzzy Logic control

    Directory of Open Access Journals (Sweden)

    Ahmed M. Othman

    2012-12-01

    Full Text Available In the recent years, the solar energy becomes one of the most important alternative sources of electric energy, so it is important to improve the efficiency and reliability of the photovoltaic (PV systems. Maximum power point tracking (MPPT plays an important role in photovoltaic power systems because it maximize the power output from a PV system for a given set of conditions, and therefore maximize their array efficiency. This paper presents a maximum power point tracker (MPPT using Fuzzy Logic theory for a PV system. The work is focused on the well known Perturb and Observe (P&O algorithm and is compared to a designed fuzzy logic controller (FLC. The simulation work dealing with MPPT controller; a DC/DC Ćuk converter feeding a load is achieved. The results showed that the proposed Fuzzy Logic MPPT in the PV system is valid.

  19. The Most Economical Mode of Power Supply for Remote and Less Developed Areas in China: Power Grid Extension or Micro-Grid?

    Directory of Open Access Journals (Sweden)

    Sen Guo

    2017-05-01

    Full Text Available There are still residents without access to electricity in some remote and less developed areas of China, which lead to low living standards and hinder sustainable development for these residents. In order to achieve the strategic targets of solving China’s energy poverty, realizing basic energy service equalization, and comprehensively building up a moderately prosperous society, several policies have been successively promulgated in recent years, which aim to solve the electricity access issue for residents living in remote and less developed areas. It is of great importance to determine the most economical mode of power supply in remote and less developed areas, which directly affects the economic efficiency of public investment projects. Therefore, this paper focuses on how to select the most economical power supply mode for rural electrification in China. Firstly, the primary modes to supply electricity for residents living in the remote and less developed areas are discussed, which include power grid extension mode and micro-grid mode. Secondly, based on the levelized cost of electricity (LCOE technique, the life cycle economic cost accounting model for different power supply modes are built. Finally, taking a minority nationality village in Yunnan province as an example, the empirical analysis is performed, and the LCOEs of various possible modes for rural electrification are accounted. The results show that the photovoltaic (PV-based independent micro-grid system is the most economical due to the minimum LCOE, namely 0.658 RMB/kWh. However, other power supply modes have much higher LCOEs. The LCOEs of power grid extension model, wind-based independent micro-grid system and biomass-based independent micro-grid system are 1.078 RMB/kWh, 0.704 RMB/kWh and 0.885 RMB/kWh, respectively. The proposed approach is effective and practical, which can provide reference for rural electrification in China.

  20. Fault Transient Analysis and Protection Performance Evaluation within a Large-scale PV Power Plant

    Directory of Open Access Journals (Sweden)

    Wen Jinghua

    2016-01-01

    Full Text Available In this paper, a short-circuit test within a large-scale PV power plant with a total capacity of 850MWp is discussed. The fault currents supplied by the PV generation units are presented and analysed. According to the fault behaviour, the existing protection coordination principles with the plant are considered and their performances are evaluated. Moreover, these protections are examined in simulation platform under different operating situations. A simple measure with communication system is proposed to deal with the foreseeable problem about the current protection scheme in the PV power plant.

  1. Self-organized synchronization in decentralized power grids.

    Science.gov (United States)

    Rohden, Martin; Sorge, Andreas; Timme, Marc; Witthaut, Dirk

    2012-08-10

    Robust synchronization (phase locking) of power plants and consumers centrally underlies the stable operation of electric power grids. Despite current attempts to control large-scale networks, even their uncontrolled collective dynamics is not fully understood. Here we analyze conditions enabling self-organized synchronization in oscillator networks that serve as coarse-scale models for power grids, focusing on decentralizing power sources. Intriguingly, we find that whereas more decentralized grids become more sensitive to dynamical perturbations, they simultaneously become more robust to topological failures. Decentralizing power sources may thus facilitate the onset of synchronization in modern power grids.

  2. Control scheme towards enhancing power quality and operational efficiency of single-phase two-stage grid-connected photovoltaic systems

    Directory of Open Access Journals (Sweden)

    Mahmoud Salem

    2015-12-01

    Full Text Available Achieving high reliable grid-connected photovoltaic (PV systems with high power quality and high operation efficiency is highly required for distributed generation units. A double grid-frequency voltage ripple is found on the dc-link voltage in single-phase photovoltaic grid-connected systems due to the unbalance of the instantaneous dc input and ac output powers. This voltage ripple has undesirable effects on the power quality and operational efficiency of the whole system. Harmonic distortion in the injected current to the grid is one of the problems caused by this double grid-frequency voltage ripple. The double grid frequency ripple propagates to the PV voltage and current which disturb the extracted maximum power from the PV array. This paper introduces intelligent solutions towards mitigate the side effects of the double grid-frequency voltage ripple on the transferred power quality and the operational efficiency of single-phase two-stage grid-connected PV system. The proposed system has three control loops: MPPT control loop, dc-link voltage control loop and inverter current control loop. Solutions are introduced for all the three control loops in the system. The current controller cancels the dc-link voltage effect on the total harmonic distortion of the output current. The dc-link voltage controller is designed to generate a ripple free reference current signal that leads to enhance the quality of the output power. Also a modified MPPT controller is proposed to optimize the extracted power from the PV array. Simulation results show that higher injected power quality is achieved and higher efficiency of the overall system is realized.

  3. Operational Practice and Prospects of China Southern Power Grid

    Institute of Scientific and Technical Information of China (English)

    Wang Jiuling; Wang Ben

    2006-01-01

    @@ The Applied Research on Higher Voltage Class for China Southern Power Grid completed at the end of 2004 pointed to a conclusion that transmission schemes using ±800-kV DC and 1000-kV AC are feasible to the southern grid. According to the grid's 11th Five-Year Plan, the ultra-high voltage transmission will take its place in the power grid soon.

  4. Frequency Adaptive Repetitive Control of Grid-Tied Three-Phase PV iInverters

    DEFF Research Database (Denmark)

    Zhou, Keliang; Yang, Yongheng; Blaabjerg, Frede

    2016-01-01

    in the presence of practical time-varying grid frequency. This paper explores frequency adaptive repetitive control strategy for grid-interfaced converters, which employs fractional delay filter to adapt to the change of grid frequency. Case studies with experimental results of three-phase grid-connected...... converter systems are provided to verify the proposed controller....

  5. Grid Converters for Photovoltaic and Wind Power Systems

    DEFF Research Database (Denmark)

    Teodorescu, Remus; Liserre, Marco; Rodriguez, Pedro

    power, operation within a wide range of voltage and frequency, voltage ride-through capability, reactive current injection during faults, grid services support. This book explains the topologies, modulation and control of grid converters for both photovoltaic and wind power applications. In addition...... to power electronics, this book focuses on the specific applications in photovoltaic wind power systems where grid condition is an essential factor. With a review of the most recent grid requirements for photovoltaic and wind power systems, the book discusses these other relevant issues: Modern grid...... inverter topologies for photovoltaic and wind turbines Islanding detection methods for photovoltaic systems Synchronization techniques based on second order generalized integrators (SOGI) Advanced synchronization techniques with robust operation under grid unbalance condition grid filter design and active...

  6. Vehicle-to-Grid Power in Danish Electric Power Systems

    DEFF Research Database (Denmark)

    Pillai, Jayakrishnan Radhakrishna; Bak-Jensen, Birgitte

    2009-01-01

    The integration of renewable energy systems is often constrained by the variable nature of their output. This demands for the services of storing the electricity generated from most of the renewable energy sources. Vehicle-to-grid (V2G) power could use the inherent energy storage of electric...... vehicles and its quick response time to balance and stabilize a power system with fluctuating power. This paper outlines the use of battery electric vehicles in supporting large-scale integration of renewable energy in the Danish electric power systems. The reserve power requirements for a high renewable...... energy penetration could be met by an amount of V2G based electric vehicles less than 10% of the total vehicle need in Denmark. The participation of electric vehicle in ancillary services would earn significant revenues to the vehicle owner. The power balancing services of electric vehicles...

  7. Vehicle-to-Grid Power in Danish Electric Power Systems

    DEFF Research Database (Denmark)

    Pillai, Jayakrishnan Radhakrishna; Bak-Jensen, Birgitte

    2009-01-01

    The integration of renewable energy systems is often constrained by the variable nature of their output. This demands for the services of storing the electricity generated from most of the renewable energy sources. Vehicle-to-grid (V2G) power could use the inherent energy storage of electric...... vehicles and its quick response time to balance and stabilize a power system with fluctuating power. This paper outlines the use of battery electric vehicles in supporting large-scale integration of renewable energy in the Danish electric power systems. The reserve power requirements for a high renewable...... energy penetration could be met by an amount of V2G based electric vehicles less than 10% of the total vehicle need in Denmark. The participation of electric vehicle in ancillary services would earn significant revenues to the vehicle owner. The power balancing services of electric vehicles...

  8. Reduction of Topological Connectivity Information in Electric Power Grids

    DEFF Research Database (Denmark)

    Prostejovsky, Alexander; Gehrke, Oliver; Marinelli, Mattia;

    2016-01-01

    Electric power distribution grids increasingly use higher levels of monitoring and automation, both dependent on grid topology. However, the total amount of information to adequately describe power grids is vast and needs to be reduced when used locally. This work presents an approach for reducing...... and assembling power grid topologies in a decentralized way, such that full details of the local grid neighborhood are preserved, while remote areas get reduced in detail. Full connectivity information is retained. Practical evaluation is performed on a modified version of the 906-bus IEEE European low...

  9. Improvement of Power Quality using Fuzzy Logic Controller In Grid Connected Photovoltaic Cell Using UPQC

    Directory of Open Access Journals (Sweden)

    K.Ramalingeswara Rao

    2014-07-01

    Full Text Available In this paper, the design of combined operation of UPQC and PV-ARRAY is designed. The proposed system is composed of series and shunt inverters connected back to back by a dc-link to which pv-array is connected. This system is able to compensate voltage and current related problems both in inter-connected mode and islanding mode by injecting active power to grid. The fundamental aspect is that the power electronic devices (PE and sensitive equipments (SE are normally designed to work in non-polluted power system, so they would suffer from malfunctions when supply voltage is not pure sinusoidal. Thus this proposed operating strategy with flexible operation mode improves the power quality of the grid system combining photovoltaic array with a control of unified power quality conditioner. Pulse Width Modulation (PWM is used in both three phase four leg inverters. A Proportional Integral (PI and Fuzzy Logic Controllers are used for power quality improvement by reducing the distortions in the output power. The simulated results were compared among the two controller’s strategies With pi controller and fuzzy logic controller

  10. Economic evaluation of a photovoltaic (PV) power generation system with battery; Battery wo heiyoshita taiyoko hatsuden system no keizaiseihyoka

    Energy Technology Data Exchange (ETDEWEB)

    Tomikura, S.; Kaya, Y. [Keio University, Tokyo (Japan)

    1997-01-30

    To improve the correlation characteristics between unstable output of PV system and demand, and to improve its economical value, use of battery was investigated. In this study, at first, solution of constrained optimization problem was derived in the case when the demand and PV output were defined by the continuous function, to obtain the break-even cost of PV system. To investigate the charge from PV in daytime or the charge from base power source at night, peak, middle and base power sources were considered. Finally, break-even cost of the PV system with battery was calculated as a trial using a multiple time zone model having PV and usual three power sources. As a result, the difference ranging from 25000 to 29000 yen in the break-even costs between PV and PV with battery was provided, which was considered to be a pure increase of the value using battery. 10 refs., 7 figs., 1 tab.

  11. Economic evaluation of a photovoltaic (PV) power generation system with battery; Battery wo heiyoshita taiyoko hatsuden system no keizaiseihyoka

    Energy Technology Data Exchange (ETDEWEB)

    Tomikura, S.; Kaya, Y. [Keio University, Tokyo (Japan)

    1997-01-30

    To improve the correlation characteristics between unstable output of PV system and demand, and to improve its economical value, use of battery was investigated. In this study, at first, solution of constrained optimization problem was derived in the case when the demand and PV output were defined by the continuous function, to obtain the break-even cost of PV system. To investigate the charge from PV in daytime or the charge from base power source at night, peak, middle and base power sources were considered. Finally, break-even cost of the PV system with battery was calculated as a trial using a multiple time zone model having PV and usual three power sources. As a result, the difference ranging from 25000 to 29000 yen in the break-even costs between PV and PV with battery was provided, which was considered to be a pure increase of the value using battery. 10 refs., 7 figs., 1 tab.

  12. Power grid simulation applications developed using the GridPACK™ high performance computing framework

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Shuangshuang; Chen, Yousu; Diao, Ruisheng; Huang, Zhenyu (Henry); Perkins, William; Palmer, Bruce

    2016-12-01

    This paper describes the GridPACK™ software framework for developing power grid simulations that can run on high performance computing platforms, with several example applications (dynamic simulation, static contingency analysis, and dynamic contingency analysis) that have been developed using GridPACK.

  13. REVIEW ON GRID INTERFACING OF MULTIMEGAWATT PHOTOVOLTAIC INVERTERS

    OpenAIRE

    2016-01-01

    This paper presents review on the latest development of control of grid connected photovoltaic energy conversion system. Also this paper present existing systems control algorithm for three-phase and single phase grid-connected photovoltaic (PV) system.  This paper focuses on one aspect of solar energy, namely grid interfacing of large-scale PV farms. This Grid-connected photovoltaic  i.e. PV systems can provide a number of benefits to electric utilities, such as power loss reductio...

  14. 大型太阳能并网发电模型及应用%Model of Large PV and Its Applications on Power System Analysis

    Institute of Scientific and Technical Information of China (English)

    杨秀媛; 刘小河; 张芳; 张利

    2011-01-01

    大型太阳能光伏发电是解决电力供应的有效途径之一.由于光伏发电的不确定性,大规模光伏电源的接入将对电力系统的运行产生影响.目前,用于分析大型光伏系统对电网暂态稳定性影响的整体模型尚不成熟.在分析光伏系统各组成元件模型的基础上,给出了大型光伏并网发电系统的暂态模型;通过对光照变化、并网点电压变化2种情况下的响应进行仿真,验证了模型的有效性.分析了大型光伏电源并入某地区电网时对系统频率稳定、电压稳定和功角稳定的影响.所提出方法为含有光伏发电的电网提供了借鉴.%Large scale photovoltaic (PV) generation is another way to generate electricity. When a large capacity PV system connected to the grid, much impact could be brought to the grid due to its uncertainty. Presently, the whole model of PV system is still defective for the analysis of power system transient stability. The transient model of large scale grid-connected PV generation system was given based on the model of each component of PV generation system. Response of the model was simulated respectively when the illumination changes, or the voltage at grid-connected point changes. PV systems of different capacities connected to a district grid were studied in the respect of frequency stability, voltage stability and power angle stability. The methods proposed could be applied to the power grid with photovoltaic generation integration.

  15. Study on model current predictive control method of PV grid- connected inverters systems with voltage sag

    Science.gov (United States)

    Jin, N.; Yang, F.; Shang, S. Y.; Tao, T.; Liu, J. S.

    2016-08-01

    According to the limitations of the LVRT technology of traditional photovoltaic inverter existed, this paper proposes a low voltage ride through (LVRT) control method based on model current predictive control (MCPC). This method can effectively improve the photovoltaic inverter output characteristics and response speed. The MCPC method of photovoltaic grid-connected inverter designed, the sum of the absolute value of the predictive current and the given current error is adopted as the cost function with the model predictive control method. According to the MCPC, the optimal space voltage vector is selected. Photovoltaic inverter has achieved automatically switches of priority active or reactive power control of two control modes according to the different operating states, which effectively improve the inverter capability of LVRT. The simulation and experimental results proves that the proposed method is correct and effective.

  16. Distributed Generation and Islanding – Study on Converter Modeling of PV Grid-Connected Systems under Islanding Phenomena

    OpenAIRE

    2010-01-01

    The technique to derive a dc-ac full bridge switching converter for a PV grid-connected system are proposed in this paper. An analysis of islanding phenomena due to load variations of R and RLC connections can be easily derived by using the state-space averaging technique and the piecewise technique with feedback current control by setting up the duty cycle with sinusoidal terms around constant value of 0.5. The solution of the two proposed models can be handled via MATLAB/SIMULINK in fast sp...

  17. Market partner orientation in power grid operation; Marktpartnerorientierung im Netzbetrieb

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, Claudia; Gebhardt, Andreas [Buelow und Consorten GmbH, Hamburg (Germany)

    2012-11-15

    Customer orientation is often neglected in power grid operation. Power grid owners have natural monopolies and defined territories and so far had little reason to consider their customers' needs. This is changing with changed boundary conditions. In the competition for concessions and customers for non-regulated services, those grid owners will prevail in the long run wo are aware of their market partners, their power and expectations, and wo are prepared to implement profit-oriented customer orientation measures. (orig.)

  18. The PCHD Model and Control of TNPC PV Grid-connected Inverter%TNPC型光伏并网逆变器的PCHD建模与控制

    Institute of Scientific and Technical Information of China (English)

    张百乐; 王久和; 赵凤姣

    2014-01-01

    根据T型中点箝位(T-type neutral point clamped,TNPC)型光伏并网逆变器拓扑结构建立端口受控的耗散哈密顿(port controlled Hamiltonian with dissipation,PCHD)数学模型。基于此数学模型,采用互联和阻尼配置无源控制(interconnection and damping assignment passivity- based control,IDA-PBC)方法设计控制器。介绍三电平空间矢量调制算法的原理及实现方法。仿真结果表明,该文设计的基于PCHD模型的TNPC型光伏并网逆变器无源控制器能够使光伏并网逆变器实现网侧单位功率因数、电流低谐波;同时,使并网逆变器具有良好的动态、静态特性。%ABSTRACT:Based on the control method of energy shaping and port controlled Hamiltonian with dissipation (PCHD), the model of the TNPC (T-type neutral point clamped) PV grid-connected inverter and its control were studied. Based on the model, the controller was designed by using the method of interconnection and damping assignment passivity-based control. It analyzed the principle and realization method of three-level space vector modulation algorithm. Simulation results show that the designed passive controller of TNPC PV grid-connected inverter can achieve unity power factor, the total harmonic distortion of grid-connected current is low, and the controller also makes the inverter have good dynamic and static performances.

  19. Evolution of integrated panel structural design and interfaces for PV power plants

    Science.gov (United States)

    Arnett, J. C.; Anderson, A. J.; Robertson, R. E.

    1983-01-01

    The evolution of integrated photovoltaic (PV) panel design at ARCO Solar is discussed. Historically, framed PV modules of about 1 x 4-ft size were individually mounted in the field on fixed support structures and interconnected electrically with cables to build higher-power arrays. When ARCO Solar saw the opportunity in 1982 to marry its PV modules with state-of-the-art heliostat trackers developed by ARCO Power Systems, it became obvious that mounting individual modules was impractical. For this project, the framed modules were factory-assembled into panels and interconnected with cables before being mounted on the trackers. Since then, ARCO Solar made considerable progress and gained substantial experience in the design and fabrication of large PV panels. Constraints and criteria considered in these design activities included static and dynamic loads; assembly and transportation equipment and logistics, structural and electrical interfaces, and safety and grounding concerns.

  20. Evolution of integrated panel structural design and interfaces for PV power plants

    Science.gov (United States)

    Arnett, J. C.; Anderson, A. J.; Robertson, R. E.

    1983-01-01

    The evolution of integrated photovoltaic (PV) panel design at ARCO Solar is discussed. Historically, framed PV modules of about 1 x 4-ft size were individually mounted in the field on fixed support structures and interconnected electrically with cables to build higher-power arrays. When ARCO Solar saw the opportunity in 1982 to marry its PV modules with state-of-the-art heliostat trackers developed by ARCO Power Systems, it became obvious that mounting individual modules was impractical. For this project, the framed modules were factory-assembled into panels and interconnected with cables before being mounted on the trackers. Since then, ARCO Solar made considerable progress and gained substantial experience in the design and fabrication of large PV panels. Constraints and criteria considered in these design activities included static and dynamic loads; assembly and transportation equipment and logistics, structural and electrical interfaces, and safety and grounding concerns.

  1. A Survey on Next-generation Power Grid Data Architecture

    Energy Technology Data Exchange (ETDEWEB)

    You, Shutang [University of Tennessee, Knoxville (UTK); Zhu, Dr. Lin [University of Tennessee (UT); Liu, Yong [ORNL; Liu, Yilu [ORNL; Shankar, Mallikarjun (Arjun) [ORNL; Robertson, Russell [Grid Protection Alliance; King Jr, Thomas J [ORNL

    2015-01-01

    The operation and control of power grids will increasingly rely on data. A high-speed, reliable, flexible and secure data architecture is the prerequisite of the next-generation power grid. This paper summarizes the challenges in collecting and utilizing power grid data, and then provides reference data architecture for future power grids. Based on the data architecture deployment, related research on data architecture is reviewed and summarized in several categories including data measurement/actuation, data transmission, data service layer, data utilization, as well as two cross-cutting issues, interoperability and cyber security. Research gaps and future work are also presented.

  2. Design for Reliability of Power Electronics for Grid-Connected Photovoltaic Systems

    DEFF Research Database (Denmark)

    Yang, Yongheng; Sangwongwanich, Ariya; Blaabjerg, Frede

    2016-01-01

    Power electronics is the enabling technology for optimizing energy harvesting from renewable systems like Photovoltaic (PV) and wind power systems, and also for interfacing grid-friendly energy systems. Advancements in the power semiconductor technology (e.g., wide band-gap devices) have pushed...... the conversion efficiency of power electronics to above 98%, where however te reliability of power electronics is becoming of high concern. Therefore, it is important to design for reliable power electronic systems to lower the risks of many failures during operation; otherwise will increase the cost...... as well as to design for high reliability at an early stage. Knowhow of the loading in power electronics in harsh operating environments (e.g., fluctuating ambient temperature and solar irradiance) is important for life-time prediction, as the prerequisite of Deign for Reliability (DfR). Hence...

  3. Frequency Adaptive Repetitive Control of Grid-Tied Three-Phase PV Inverters

    DEFF Research Database (Denmark)

    Zhou, Keliang; Yang, Yongheng; Blaabjerg, Frede

    2016-01-01

    Repetitive control offers an accurate current control scheme for grid-tied converters to feed high quality sinusoidal current into the grid. However, with grid frequency being treated as a constant value, conventional repetitive controller fail to produce high quality feeding current...

  4. Grid simulator for power quality assessment of micro-grids

    DEFF Research Database (Denmark)

    Carrasco, Joaquin Eloy Garcia; Vasquez, Juan Carlos; Guerrero, Josep M.

    2013-01-01

    In this study, a grid simulator based on a back-to-back inverter topology with resonant controllers is presented. The simulator is able to generate three-phase voltages for a range of amplitudes and frequencies with different types of perturbations, such as voltage sags, steady-state unbalanced v...

  5. Model predictive control for power fluctuation supression in hybrid wind/PV/battery systems

    DEFF Research Database (Denmark)

    You, Shi; Liu, Zongyu; Zong, Yi

    2015-01-01

    predictive control (MPC)-based algorithm for battery management in a hybrid wind/PV/battery system to suppress the short-term power fluctuation on the ‘minute’ scale. A case study with data collected from a practical hybrid system setup is used to demonstrate the effectiveness of the proposed algorithm......A hybrid energy system, the combination of wind turbines, PV panels and battery storage with effective control mechanism, represents a promising solution to the power fluctuation problem when integrating renewable energy resources (RES) into conventional power systems. This paper proposes a model...... together with a Monte Carlo simulation-based sensitivity analysis. In addition to illustrating the complementarity between the fluctuations of wind power and PV power, the results prove the proposed MPC algorithm is effective in fluctuation suppression but sensitive to factors such as forecast accuracy...

  6. National power grid simulation capability : need and issues

    Energy Technology Data Exchange (ETDEWEB)

    Petri, Mark C. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2009-06-02

    On December 9 and 10, 2008, the Department of Homeland Security (DHS) Science and Technology Directorate sponsored a national workshop at Argonne National Laboratory to explore the need for a comprehensive modeling and simulation capability for the national electric power grid system. The workshop brought together leading electric power grid experts from federal agencies, the national laboratories, and academia to discuss the current state of power grid science and engineering and to assess if important challenges are being met. The workshop helped delineate gaps between grid needs and current capabilities and identify issues that must be addressed if a solution is to be implemented. This report is a result of the workshop and highlights power grid modeling and simulation needs, the barriers that must be overcome to address them, and the benefits of a national power grid simulation capability.

  7. Power grid complex network evolutions for the smart grid

    Science.gov (United States)

    Pagani, Giuliano Andrea; Aiello, Marco

    2014-02-01

    The shift towards an energy grid dominated by prosumers (consumers and producers of energy) will inevitably have repercussions on the electricity distribution infrastructure. Today the grid is a hierarchical one delivering energy from large scale facilities to end-users. Tomorrow it will be a capillary infrastructure at the medium and low voltage levels that will support local energy trading among prosumers. We investigate how different network topologies and growth models facilitate a more efficient and reliable network, and how they can facilitate the emergence of a decentralized electricity market. We show how connectivity plays an important role in improving the properties of reliability and path-cost reduction. Our results indicate that a specific type of evolution balances best the ratio between increased connectivity and costs to achieve the network growth.

  8. Fractal Characteristics Analysis of Blackouts in Interconnected Power Grid

    DEFF Research Database (Denmark)

    Wang, Feng; Li, Lijuan; Li, Canbing

    2017-01-01

    The power failure models are a key to understand the mechanism of large scale blackouts. In this letter, the similarity of blackouts in interconnected power grids (IPGs) and their sub-grids is discovered by the fractal characteristics analysis to simplify the failure models of the IPG. The distri......The power failure models are a key to understand the mechanism of large scale blackouts. In this letter, the similarity of blackouts in interconnected power grids (IPGs) and their sub-grids is discovered by the fractal characteristics analysis to simplify the failure models of the IPG....... The distribution characteristics of blackouts in various sub-grids are demonstrated based on the Kolmogorov-Smirnov (KS) test. The fractal dimensions (FDs) of the IPG and its sub-grids are then obtained by using the KS test and the maximum likelihood estimation (MLE). The blackouts data in China were used...

  9. One-Year Monitoring PV Power Plant Installed on Rooftop of Mineirão Fifa World Cup/Olympics Football Stadium

    Directory of Open Access Journals (Sweden)

    Luís G. Monteiro

    2017-02-01

    Full Text Available This paper presents results of one-year monitoring of AC side electrical parameters and the characterization of local solar radiation at the biggest rooftop PV Power Plant, with an installed capacity of 1.42 MWp, mounted at Mineirão Football Stadium in Brazil. This stadium is one of the sport facilities that hosted 2014 FIFA World Cup and Rio 2016 Summer Olympics Games in the country. Results showed how it is important to study and characterize the solar resource in the region of interest, based on historic data, to provide the understanding of solar radiation and thus project PV power plants with better performance. Furthermore, AC electrical data show the behavior of active, reactive and apparent powers and the influence of the PV system on the power factor at the local grid utility connection point. Finally, PV power plant performance data (as annual final yield, performance ratio and capacity factor are also presented and compared with data from PVsyst software simulations. The results over the monitoring period were good considering the specificities of the stadium

  10. Modeling and Coordinated Control of Grid-Connected PV Generation System With Energy Storage Devices%光-储联合并网发电系统建模与协调控制

    Institute of Scientific and Technical Information of China (English)

    孔令国; 蔡国伟; 杨德友; 孙正龙

    2013-01-01

    针对光伏并网发电系统具有随机性,且不具备故障暂态电压支撑能力的特征,提出一种有效调节功率且改善低电压穿越能力的光储联合并网发电系统动态模型及协调控制策略.在电力系统仿真分析平台DIgSILENT/Power Factory中建立了光储联合并网发电系统协调控制及低电压穿越功能模型.应用协调控制策略实现储能系统和静止同步补偿器功率平衡,维持并网点电压稳定.利用气象和负荷数据,验证了上述模型及协调控制策略的有效性.%In allusion to the randomness of grid-connected PV generation system that does not possess the ability to support fault-caused transient voltage, a dynamic model and corresponding coordinated control strategy for grid-connected PV generation system with energy storage devices that can effectively regulate power output and improve low-voltage ride through (LVRT) are proposed. A coordinated control model of grid-connected PV generation system with energy storage devices and an LVRT model are built on power system simulation analysis platform DIgSILENT/Power Factory. Using coordinated control strategy, the power balance between energy storage devices and static synchronous compensator (STATCOM) is implemented to make the voltage at grid-connected point stable. Availability of the proposed model and coordinated control strategy is verified by meteorological data and load data.

  11. Design and Modeling of Grid Connected Hybrid Renewable Energy Power Generation

    Directory of Open Access Journals (Sweden)

    M. Kishore Reddy,

    2014-09-01

    Full Text Available This paper proposes a design and modeling of grid connected hybrid renewable energy power generation. The energy system having a photo voltaic (PV panel, Srg wind turbine and fuel cell (sofc for continuous power flow management. Fuel cells (storage & generating are added to ensure uninterrupted power supply due to the discontinuous nature of solar and wind resources. Renewable energy generated during times of plenty can be stored for use during periods when sufficient electricity is not available. But storing this energy is a difficult task: batteries and similar technologies perform well over short timescales, but over periods of weeks or months a different approach is necessary. Energy storage in the form of hydrogen is one such possibility: excess electricity is fed into an electrolyser to split water into its constituent parts, oxygen and hydrogen. The hydrogen is then used in fuel cells to produce electricity when needed which will overcome the problem of storage. This work is mainly concentrated on the design, analysis and modelling of Fuel cells and Analysis and modelling of Switched Reluctance Generator (SRG in the application of Wind Energy Generation and pv cell. Also an effective approach is proposed in this thesis to ensure renewable energy diversity and effective utilization. The pv cell, wind and fuel cell renewable energy system is digitally simulated using the MATLAB/SIMULINK software environment and fully validated for efficient energy utilizations and enhanced interface power quality under different operating conditions and load excursions

  12. A Reduced Wind Power Grid Model for Research and Education

    DEFF Research Database (Denmark)

    Akhmatov, Vladislav; Lund, Torsten; Hansen, Anca Daniela;

    2007-01-01

    A reduced grid model of a transmission system with a number of central power plants, consumption centers, local wind turbines and a large offshore wind farm is developed and implemented in the simulation tool PowerFactory (DIgSILENT). The reduced grid model is given by Energinet.dk, Transmission ...

  13. A Novel Frequency Restoring Strategy of Hydro-PV Hybrid Microgrid

    DEFF Research Database (Denmark)

    Wei, Feng; Kai, Sun; Guan, Yajuan

    2014-01-01

    The conventional PV systems based on the voltage inverters only inject dispatched power to the utility grid when they work at a grid-connected mode in the hydro-PV hybrid microgrid. Due to the droop method employed for load sharing between generators, as well as the enormous inertia of system....... The existence of frequency steady-state error and the slow active power/frequency dynamic response are inevitable. Therefore, a novel frequency restoring strategy for the hydro-PV hybrid microgrid based on the improved hierarchical control of PV systems is proposed in this paper. The output active power of PV...

  14. Grid Integration Science, NREL Power Systems Engineering Center

    Energy Technology Data Exchange (ETDEWEB)

    Kroposki, Benjamin [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2017-04-25

    This report highlights journal articles published in 2016 by researchers in the Power Systems Engineering Center. NREL's Power Systems Engineering Center published 47 journal and magazine articles in the past year, highlighting recent research in grid modernization.

  15. Market Transformation Pathways for Grid-Connected Rooftop Solar PV in Minnesota

    Energy Technology Data Exchange (ETDEWEB)

    Abbey, Ross [Fresh Energy, St. Paul, MN (United States); Ross, Brian [CR Planning, Minneapolis, MN (United States)

    2013-06-03

    This report presents the market and policy findings of the Minnesota Solar Challenge program. The report draws on information collected from state agencies, local government units, solar industry participants, rooftop photovoltaic (PV) adopters (sometimes called customer-generators), state and national experts, the Commerce distributed generation stakeholder process, and the numerous reports and data sets referenced herein.

  16. Smart grid communication-enabled intelligence for the electric power grid

    CERN Document Server

    Bush, Stephen F

    2014-01-01

    This book bridges the divide between the fields of power systems engineering and computer communication through the new field of power system information theory. Written by an expert with vast experience in the field, this book explores the smart grid from generation to consumption, both as it is planned today and how it will evolve tomorrow. The book focuses upon what differentiates the smart grid from the ""traditional"" power grid as it has been known for the last century. Furthermore, the author provides the reader with a fundamental understanding of both power systems and communication ne

  17. PV water pumping: NEOS Corporation recent PV water pumping activities

    Energy Technology Data Exchange (ETDEWEB)

    Lane, C.

    1995-11-01

    NEOS Corporation has been very active in PV-powered water pumping, particularly with respect to electric utilities. Most of the recent activity has been through the Photovoltaic Services Network (PSN). The PSN is an independent, not-for-profit organization comprised of all types of electric utilities: rural electric coops, public power districts, investor-owned utilities, and power marketing agencies. The PSN`s mission is to work pro-actively to promote utility involvement in PV through education and training. PV information is distributed by the PSN in three primary forms: (1) consultation with PSN technical service representatives: (2) literature generated by the PSN; and (3) literature published by other organizations. The PSN can also provide assistance to members in developing PV customer service programs. The PSN`s product support activities include consolidation of information on existing packaged PV systems and facilitation of the development of new PV product packages that meet utility-defined specifications for cost performance, and reliability. The PSN`s initial product support efforts will be focused on commercially available packaged PV systems for a variety of off-grid applications. In parallel with this effort, if no products exist that meet the PSN`s functional specifications, the PSN will initiate the second phase of product development support process by encouraging the development of new packaged systems. Through these services and product support activities, the PSN anticipates engaging all segments for the PV industry, thus providing benefits to PV systems suppliers as well as local PV service contractors.This paper describes field testing of pv power systems for water pumping.

  18. Error Assessment of Solar Irradiance Forecasts and AC Power from Energy Conversion Model in Grid-Connected Photovoltaic Systems

    Directory of Open Access Journals (Sweden)

    Gianfranco Chicco

    2015-12-01

    Full Text Available Availability of effective estimation of the power profiles of photovoltaic systems is essential for studying how to increase the share of intermittent renewable sources in the electricity mix of many countries. For this purpose, weather forecasts, together with historical data of the meteorological quantities, provide fundamental information. The weak point of the forecasts depends on variable sky conditions, when the clouds successively cover and uncover the solar disc. This causes remarkable positive and negative variations in the irradiance pattern measured at the photovoltaic (PV site location. This paper starts from 1 to 3 days-ahead solar irradiance forecasts available during one year, with a few points for each day. These forecasts are interpolated to obtain more irradiance estimations per day. The estimated irradiance data are used to classify the sky conditions into clear, variable or cloudy. The results are compared with the outcomes of the same classification carried out with the irradiance measured in meteorological stations at two real PV sites. The occurrence of irradiance spikes in “broken cloud” conditions is identified and discussed. From the measured irradiance, the Alternating Current (AC power injected into the grid at two PV sites is estimated by using a PV energy conversion model. The AC power errors resulting from the PV model with respect to on-site AC power measurements are shown and discussed.

  19. Power fluctuations in micro-grids introduced by photovoltaics: Analysis and solutions

    Energy Technology Data Exchange (ETDEWEB)

    Woyte, A.; Belmans, R. [Katholieke Universiteit Leuven (Belgium). ESAT-ELECTA; Bodach, M. [Technische Univ. Chemnitz (Germany). Fakultaet fuer Elektrotechnik und Informationstechnik; Nijs, J. [Katholieke Universiteit Leuven (Belgium). ESAT-ELECTA]|[Photovoltech SA, Leuven (Belgium)

    2003-07-01

    Solar radiation is characterized by short fluctuations introduced by passing clouds. In stand-alone power systems, minigrids and grids where the power exchange with a back-up system needs to be minimized, the consequences of these fluctuations of solar irradiance are undesirable. For buffering cloud-induced power-flow fluctuations introduced by PV, the application of supercapacitors is studied. An assessment of the need for additional short-term storage must focus on the statistical properties of amplitude and persistence of cloud-induced fluctuations. As a tool for the assessment of these parameters, the localized spectral analysis based on a stationary wavelet decomposition is applied. Results show that supercapacitors are well suited to buffer fluctuations from PV systems as they are introduced mainly by moving clouds. For a given 1-kWp PV array, already a small number of commercially available supercapacitors can buffer fluctuations of up to one hour persistence even at a high variability of solar irradiance. In order to buffer only short fluctuations even much less supercapacitors would be sufficient. (orig.)

  20. Design of Fuzzy-PID Controller of PV Grid-connected Control System%光伏并网系统模糊PID控制器的设计

    Institute of Scientific and Technical Information of China (English)

    贺运胜

    2013-01-01

    As illumination is stochastic and uncertain, a set of PID parameters can hardly achieve satisfactory control performance for grid-connected control for photovoltaic system. Based on the mathematical model of three-phase two-stage PV grid inverter, fuzzy-PID control strategy is applied in the grid control of PV system. Digital simulation and physical simulation show that fuzzy-PID control strategy can improve the PV system grid control dynamic process and the PV system can smoothly connect the grid.%由于光照具有随机性和不确定性等特点,光伏并网控制若采用传统PID控制,仅一组固定的参数难以在不同光照下均具有良好的并网控制效果。在三相两级式并网逆变器数学模型的基础上,将模糊PID控制策略引入光伏系统的并网控制中。通过数字仿真和物理仿真表明模糊控制与PID控制相结合的模糊PID控制,改善了光伏系统并网控制的动态过程,能够实现光伏系统的平滑并网。

  1. Guest Editorial Special Issue on Power Quality in Smart Grids

    DEFF Research Database (Denmark)

    Guerrero, Josep M.

    2017-01-01

    Smart grid (SG) is usually described as a power system utilizing information and communication technology (ICT) and advanced monitoring systems to improve the grid performance and offer a wide range of additional services for the consumers. Some of the main features of such a grid are self......-healing from power disturbances, efficient energy management, automation based on ICT and advanced metering infrastructures (smart metering), integration of distributed power generation, renewable energy resources and storage units as well as high power quality and reliability. In this regard, the concept...

  2. A New Method of PV Array Faults Diagnosis in Smart Grid

    Directory of Open Access Journals (Sweden)

    Ze Cheng

    2014-01-01

    Full Text Available A new fault diagnosis method is proposed for PV arrays with SP connection in this study, the advantages of which are that it would minimize the number of sensors needed and that the accuracy and anti-interference ability are improved with the introduction of fuzzy group decision-making theory. We considered five “decision makers” contributing to the diagnosis of PV array faults, including voltage, current, environmental temperature, panel temperature, and solar illumination. The accuracy and reliability of the proposed method were verified experimentally, and the possible factors contributing to diagnosis deviation were analyzed, based on which solutions were suggested to reduce or eliminate errors in aspects of hardware and software.

  3. Environmental impacts of large-scale grid-connected ground-mounted PV installations

    OpenAIRE

    Beylot, Antoine; Payet, Jérôme; Puech, Clément; Adra, Nadine; Jacquin, Philippe; Blanc, Isabelle; Beloin-Saint-Pierre, Didier

    2014-01-01

    World Renewable Energy Congress - Sweden, 8-13 May, 2011, Linköping, Sweden; International audience; This study characterizes the environmental performances of large-scale ground-mounted PV installations by considering a life cycle approach. The methodology is based on the application of the existing international standards of Life Cycle Assessment (LCA). Four scenarios are compared, considering fixed-mounting structures with (1) primary aluminum supports or (2) wood supports, and mobile stru...

  4. Environmental Impacts of Large-Scale Grid-Connected Ground-Mounted PV Installations

    OpenAIRE

    Beylot, Antoine; Payet, Jérôme; Puech, Clément; Adra, Nadine; Jacquin, Philippe; Blanc, Isabelle; Beloin-Saint-Pierre, Didier

    2011-01-01

    Available on: http://www.ep.liu.se/ecp/057/vol11/007/ecp57vol11_007.pdf; International audience; This study characterizes the environmental performances of large-scale ground-mounted PV installations by considering a life-cycle approach. The methodology is based on the application of the existing international standards of Life Cycle Assessment (LCA). Four scenarios are compared, considering fixedmounting structures with (1) primary aluminum supports or (2) wood supports, and mobile structure...

  5. Grid synchronization for advanced power processing and FACTS in wind power systems

    DEFF Research Database (Denmark)

    Luna, A.; Rocabert, J.; Vazquez, G.

    2010-01-01

    and also to support the grid operation, as the new grid codes demand. The connection of FACTS based on power converters, such as STATCOMs, are also contributing to the integration of renewable energies improving their behavior under contingencies. However, in both cases it is needed to have a grid voltage...... constraints will be established according to the Grid Code Requirements (GCRs)....

  6. Concept of large scale PV-WT-PSH energy sources coupled with the national power system

    Directory of Open Access Journals (Sweden)

    Jurasz Jakub

    2017-01-01

    Full Text Available Intermittent/non-dispatchable energy sources are characterized by a significant variation of their energy yield over time. In majority of cases their role in energy systems is marginalized. However, even in Poland which is strongly dedicated to its hard and brown coal fired power plants, the wind generation in terms of installed capacity starts to play a significant role. This paper briefly introduces a concept of wind (WT and solar (PV powered pumped storage hydroelectricity (PSH which seems to be a viable option for solving the problem of the variable nature of PV and WT generation. Additionally we summarize the results of our so far conducted research on the integration of variable renewable energy sources (VRES to the energy systems and present conclusions which strictly refer to the prospects of large scale PV-WT-PSH operating as a part of the polish energy system.

  7. EMISSIONS REDUCTION DATA FOR GRID-CONNECTED PHOTOVOLTAIC POWER SYSTEMS

    Science.gov (United States)

    This study measured the pollutant emission reduction potential of 29 photovoltaic (PV) systems installed on residential and commercial building rooftops across the U.S. from 1993 through 1997. The U.S. Environmental Protection Agency (EPA) and 21 electric power companies sponsor...

  8. Scheduled Operation of PV Power Station Considering Solar Radiation Forecast Error

    Science.gov (United States)

    Takayama, Satoshi; Hara, Ryoichi; Kita, Hiroyuki; Ito, Takamitsu; Ueda, Yoshinobu; Saito, Yutaka; Takitani, Katsuyuki; Yamaguchi, Koji

    Massive penetration of photovoltaic generation (PV) power stations may cause some serious impacts on a power system operation due to their volatile and unpredictable output. Growth of uncertainty may require larger operating reserve capacity and regulating capacity. Therefore, in order to utilize a PV power station as an alternative for an existing power plant, improvement in controllability and adjustability of station output become very important factor. Purpose of this paper is to develop the scheduled operation technique using a battery system (NAS battery) and the meteorological forecast. The performance of scheduled operation strongly depends on the accuracy of solar radiation forecast. However, the solar radiation forecast contains error. This paper proposes scheduling method and rescheduling method considering the trend of forecast error. More specifically, the forecast error scenario is modeled by means of the clustering analysis of the past actual forecast error. Validity and effectiveness of the proposed method is ascertained through computational simulations using the actual PV generation data monitored at the Wakkanai PV power station and solar radiation forecast data provided by the Japan Weather Association.

  9. Maximum Power Point Tracking Method For PV Array Under Partially Shaded Condition

    Directory of Open Access Journals (Sweden)

    Belqasem Aljafari

    2016-08-01

    Full Text Available Solar radiation that hits the photovoltaic modules has a variable character depending on the position, the direction of the solar field, the season, and the hour of the day. During the trajectory of a day, a shadow may be decanted on the cell, which may be contemplated, as in the case of a building near the solar field, or unforeseeable as those created by clouds. The breakthrough of PV systems as distributed power generation systems has increased drastically in the last few years. Because of this Maximum Power Point Tracking (MPPT is becoming more and more substantial as the amount of energy generated by PV systems is increasing. A MPPT technique must be used to track the maximum power point since the MPP depends on solar irradiation and cell temperature. In general, when the impedances of the load and source are matched, the maximum power is transferred to the load from the source only. The generated energy from PV systems must be maximized, as the efficiency of solar panels is low. For that reason to get the maximum power, a PV system is repeatedly equipped with an MPP tracker. Several MPP pursuit techniques have been proposed and implemented in recent years

  10. Long-term field test of solar PV power generation using one-axis 3-position sun tracker

    KAUST Repository

    Huang, B.J.

    2011-09-01

    The 1 axis-3 position (1A-3P) sun tracking PV was built and tested to measure the daily and long-term power generation of the solar PV system. A comparative test using a fixed PV and a 1A-3P tracking PV was carried out with two identical stand-alone solar-powered LED lighting systems. The field test in the particular days shows that the 1A-3P tracking PV can generate 35.8% more electricity than the fixed PV in a partly-cloudy weather with daily-total solar irradiation HT=11.7MJ/m2day, or 35.6% in clear weather with HT=18.5MJ/m2day. This indicates that the present 1A-3P tracking PV can perform very close to a dual-axis continuous tracking PV (Kacira et al., 2004). The long-term outdoor test results have shown that the increase of daily power generation of 1A-3P tracking PV increases with increasing daily-total solar irradiation. The increase of monthly-total power generation for 1A-3P sun tracking PV is between 18.5-28.0%. The total power generation increase in the test period from March 1, 2010 to March 31, 2011, is 23.6% in Taipei (an area of low solar energy resource). The long-term performance of the present 1X-3P tracking PV is shown very close to the 1-axis continuous tracking PV in Taiwan (Chang, 2009). If the 1A-3P tracking PV is used in the area of high solar energy resource with yearly-average HT>17MJ/m2day, the increase of total long-term power generation with respect to fixed PV will be higher than 37.5%. This is very close to that of dual-axis continuous tracking PV. The 1A-3P tracker can be easily mounted on the wall of a building. The cost of the whole tracker is about the same as the regular mounting cost of a conventional rooftop PV system. This means that there is no extra cost for 1A-3P PV mounted on buildings. The 1A-3P PV is quite suitable for building-integrated applications. © 2011 Elsevier Ltd.

  11. A pragmatic performance reporting approach for describing PV Hybrid systems within mini-grids. Work in progress from IEA's PVPS Task 11 Act. 31

    Energy Technology Data Exchange (ETDEWEB)

    Swingler, Andrew [Schneider Electric, Burnaby, BC (Canada). Renewable Energies Business

    2010-07-01

    Reviewers of available PV hybrid system and mini-grid case studies are often limited to information detailing the size of the main system components (PV, battery and generator) and perhaps some historical anecdotes recalling major maintenance activities. While this enables rapid insight into the capital cost and perhaps the overall reliability of the system, this information communicates little in the way of system performance from a levelized cost of electricity and GHG emissions point of view - or what can be considered 'the business' perspective. Key system performance information must be available to effectively communicate operational system performance so system operators or perspective customers. Activity 31 of the IEA's PVPS Task 11 looks at how performance reporting can be useful, why it is often absent and what can be done to improve the current situation. This paper reviews some past work in the area of data acquisition and performance calculation used for describing PV Hybrid and mini-grid systems. In particular the IEC 61724 PV performance monitoring standard and results from the 'Benchmarking RE Components and Systems' project are considered. Ultimately, a stripped-down, easier-to-implement and flexible method for monitoring and reporting on key performance indicators is proposed based, in part, on the prior literature. The proposed framework is then used to briefly discuss the performance of two monitored PV hybrid mini-grid examples. (orig.)

  12. Economic MPC for Power Management in the Smart Grid

    DEFF Research Database (Denmark)

    Hovgaard, Tobias Gybel; Edlund, Kristian; Jørgensen, John Bagterp

    2011-01-01

    as the SmartGrid. In this paper we demonstrate the use of Economic Model Predictive Control to operate a portfolio of power generators and consumers such that the cost of producing the required power is minimized. With conventional coal and gas fired power generators representing the controllable power...

  13. Dynamic simulation of dispersed, grid-connected photovoltaic power systems: System studies

    Science.gov (United States)

    Wasynczuk, O.; Carroll, D. P.; Gareis, G. E.; Krause, P. C.; Ong, C. M.; Schwartz, R. J.

    1985-03-01

    To investigate the operating characteristics and dynamic behavior of photovoltaic (PV) power systems, four PV system configurations were selected as representative of those currently being used in PV applications. These included single and three phase, line and self commutated power conditioners with a flat plate PV array as the dc source. Detailed computer models of each of these systems were developed and incorporated into dynamic representations of typical primary and secondary distribution feeders. The dynamic electrical behavior of the PV and distribution systems following common network disturbances such as large load changes, PV system startup, and cloud cover transients are characterized. The dynamic behavior was also investigated during abnormal operating conditions following line faults, PV system malfunctions, and islanding or distribution systems containing significant levels of dispersed PV generation. Results of verification tests involving two of the single phase PV system configurations, in which the simulated response characteristics are compared with actual measurements, are also provided.

  14. Study on Capability of Power Transmission from West to East in China Southern Power Grid

    Institute of Scientific and Technical Information of China (English)

    Li Wei; Tong Mingdong; Zhang Lin; Xu Dongjie; Lin Feng; Li Xin; Zuo Zhengmin

    2007-01-01

    @@ The uneven distribution of economic development and energy resources in the Southern Power Grid, yet with stronger complementary superiority has determined the necessity to actively push forward power transmission from west to east in the Southern Power Grid and realize optimal disposition in even greater scope. To further promote transmission capability and operational security from west to east, measures including power sources disposition, unit starting schemes, power grid configuration, DC modulation and application of new transmission technologies are analyzed in this paper.

  15. Techno-economical Analysis of Rooftop Grid-connected PV Dairy Farms; Case Study of Urmia University Dairy Farm

    Science.gov (United States)

    Nikbakht, A. M.; Aste, N.; Sarnavi, H. J.; Leonforte, F.

    2017-08-01

    The global trends indicate a growing commitment to renewable energy development because of declining fossil fuels and environmental threats. Moreover, the global demographic growth coupled with rising demands for food has escalated the rate of energy consumption in food section. This study aims to investigate the techno-economic impacts of a grid-connected rooftop PV plan applied for a educational dairy farm in Urmia university, with total estimated annual electrical energy consumption of 18,283 kWh, located at the north west part of Iran. Based on the current feed-in tariff and tremendously low electricity price in agriculture section in Iran, the plants with size ranged from 14.4 to 19.7 kWp (initial investment ranged from 26,000 to 36,000 USD) would be satisfied economically.

  16. Connecting the sun. Competing in the energy sector. On the road to large scale PV grid integration

    Energy Technology Data Exchange (ETDEWEB)

    Rekinger, Manoel; Theologitis Ioannis Thomas; Masson, Gaetan [European Photovoltaic Industry Association (EPIA), Brussels (Belgium). Bussiness Intelligence Unit; Kreutzkamp, Paul; Brabandere, Karel de; Croufer, Maximilien [3E nv/sa, Brussels (Belgium). Grids and Power Markets

    2012-07-01

    With a more diversified, variable and presumably electricity-intensive energy mix, the future European electricity system will have to be more interconnected, more flexible and more decentralised, The enhancements of the grids, both at distribution and transmission level, will accompany the complete transformation of the electricity sector. They should in particular integrate the rise of distributed generation, including photovoltaic (PV) electricity, which will play a key role in Europe's electricity mix given its competitiveness trajectory. The experience of the last decade has shown that underestimating the technological and implementation potential of PV leads to suboptimal situations both from a capacity planning and a network operation point of view. Navigating through the transition towards a more sustainable energy future therefore requires tangible scenario-based forecasts. This paper is based on the latest study ''Connecting the Sun'' (September 2012) prepared by the European Photovoltaic Industry Association (EPIA) and aims to provide a vision regarding the main challenges that the current electricity system might face and how available solutions could contribute in order for solar electricity to be integrated in the electricity system avoiding security of supply concerns. (orig.).

  17. Architecture of the Florida Power Grid as a Complex Network

    CERN Document Server

    Xu, Yan; Rikvold, Per Arne

    2013-01-01

    We study the Florida high-voltage power grid as a technological network embedded in space. Measurements of geographical lengths of transmission lines, the mixing of generators and loads, the weighted clustering coefficient, as well as the organization of edge conductance weights show a complex architecture quite different from random-graph models usually considered. In particular, we introduce a parametrized mixing matrix to characterize the mixing pattern of generators and loads in the Florida Grid, which is intermediate between the random mixing case and the semi-bipartite case where generator-generator transmission lines are forbidden. Our observations motivate an investigation of optimization (design) principles leading to the structural organization of power grids. We thus propose two network optimization models for the Florida Grid as a case study. Our results show that the Florida Grid is optimized not only by reducing the construction cost (measured by the total length of power lines), but also throug...

  18. Adaptive Energy Forecasting and Information Diffusion for Smart Power Grids

    Energy Technology Data Exchange (ETDEWEB)

    Simmhan, Yogesh [Univ. of Southern California, Los Angeles, CA (United States). Dept. of Electrical Engineering; Agarwal, Vaibhav [Univ. of Southern California, Los Angeles, CA (United States). Computer Science Dept.; Aman, Saim [Univ. of Southern California, Los Angeles, CA (United States). Computer Science Dept.; Kumbhare, Alok [Univ. of Southern California, Los Angeles, CA (United States). Computer Science Dept.; Natarajan, Sreedhar [Univ. of Southern California, Los Angeles, CA (United States). Computer Science Dept.; Rajguru, Nikhil [Univ. of Southern California, Los Angeles, CA (United States). Computer Science Dept.; Robinson, Ian [Univ. of Southern California, Los Angeles, CA (United States). Green Technologies Program; Stevens, Samuel [Univ. of Southern California, Los Angeles, CA (United States). Green Technologies Program; Yin, Wei [Univ. of Southern California, Los Angeles, CA (United States). Computer Science Dept.; Zhou, Qunzhi [Univ. of Southern California, Los Angeles, CA (United States). Computer Science Dept.; Prasanna, Viktor [Univ. of Southern California, Los Angeles, CA (United States). Dept. of Electrical Engineering

    2012-05-16

    Smart Power Grids exemplify an emerging class of Cyber Physical Applications that exhibit dynamic, distributed and data intensive (D3) characteristics along with an always-on paradigm to support operational needs. Smart Grids are an outcome of instrumentation, such as Phasor Measurement Units and Smart Power Meters, that is being deployed across the transmission and distribution network of electric grids. These sensors provide utilities with improved situation awareness on near-realtime electricity usage by individual consumers, and the power quality and stability of the transmission network.

  19. Grid-connected inverter for wind power generation system

    Institute of Scientific and Technical Information of China (English)

    YANG Yong; RUAN Yi; SHEN Huan-qing; TANG Yan-yan; YANG Ying

    2009-01-01

    In wind power generation system the grid-connected inverter is an important section for energy conversion and transmission, of which the performance has a direct influence on the entire wind power generation system. The mathematical model of the grid-connected inverter is deduced firstly. Then, the space vector pulse width modulation (SVPWM) is analyzed. The power factor can be controlled close to unity, leading or lagging, which is realized based on PI-type current controller and grid voltage vector-oriented control. The control strategy is verified by the simulation and experimental results with a good sinusoidal current, a small harmonic component and a fast dynamic response.

  20. PV-hybrid village power systems in Amazonia

    Energy Technology Data Exchange (ETDEWEB)

    Warner, C.L.; Taylor, R.W. [National Renewable Energy Lab., Golden, CO (United States); Ribeiro, C.M. [Centro de Pesquisas de Energie Eletrica (CEPEL), Rio de Janeiro (Brazil)] [and others

    1996-05-01

    The Brazilian Amazon region is an ideal location for isolated mini-grid systems. Hundreds of diesel systems have been installed to supply electricity to this sparsely populated region. However, the availability of renewable energy resources makes the Amazon well-suited to renewable energy systems. This paper describes the technical aspects of two hybrid systems being installed in this region through the cooperative effort of multiple partners: U.S. Department of Energy, through NREL, and Brazilian CEPEL/Eletrobras and state electric utilities.

  1. Comparative analysis of existing models for power-grid synchronization

    CERN Document Server

    Nishikawa, Takashi

    2015-01-01

    The dynamics of power-grid networks is becoming an increasingly active area of research within the physics and network science communities. The results from such studies are typically insightful and illustrative, but are often based on simplifying assumptions that can be either difficult to assess or not fully justified for realistic applications. Here we perform a comprehensive comparative analysis of three leading models recently used to study synchronization dynamics in power-grid networks -- a fundamental problem of practical significance given that frequency synchronization of all power generators in the same interconnection is a necessary condition for a power grid to operate. We show that each of these models can be derived from first principles within a common framework based on the classical model of a generator, thereby clarifying all assumptions involved. This framework allows us to view power grids as complex networks of coupled second-order phase oscillators with both forcing and damping terms. U...

  2. Coordinated control of wind power plants in offshore HVDC grids

    DEFF Research Database (Denmark)

    Sakamuri, Jayachandra N.

    2017-01-01

    During the recent years, there has been a significant penetration of offshore wind power into the power system and this trend is expected to continue in the future. The North Sea in Europe has higher potential for offshore wind power; therefore, the North Seas Countries' Offshore Grid initiative...... power between different countries, and different synchronous areas. It is very likely that they will then be combined with offshore wind power plant (OWPP) connections in the North Sea, transforming it in a multi terminal DC (MTDC) grid and, therefore, in a fully meshed offshore DC grid in near future...... was formed among nine North Sea countries. They agreed on closer energy cooperation to enable development of an efficient and economic offshore grid infrastructure for advantages, interconnectors based on the voltage source converter based high voltage DC (HVDC) transmission system is being used to exchange...

  3. How do users interact with photovoltaic-powered products? Investigating 100 'lead-users' and 6 PV products

    NARCIS (Netherlands)

    Apostolou, G.; Reinders, Angelina H.M.E.

    2016-01-01

    In order to better understand how 'lead-users' interact with PV-powered products, the behaviour of 100 people interacting with six different PV-powered products in their daily life was analysed. The sample of respondents to be observed consisted of 20 groups, each one formed by five students of Indu

  4. How do users interact with photovoltaic-powered products? Investigating 100 'lead-users' and 6 PV products

    NARCIS (Netherlands)

    Apostolou, G.; Reinders, A.H.M.E.

    2016-01-01

    In order to better understand how 'lead-users' interact with PV-powered products, the behaviour of 100 people interacting with six different PV-powered products in their daily life was analysed. The sample of respondents to be observed consisted of 20 groups, each one formed by five students of Indu

  5. A Grid Voltage Measurement Method for Wind Power Systems during Grid Fault Conditions

    Directory of Open Access Journals (Sweden)

    Cheol-Hee Yoo

    2014-11-01

    Full Text Available Grid codes in many countries require low-voltage ride-through (LVRT capability to maintain power system stability and reliability during grid fault conditions. To meet the LVRT requirement, wind power systems must stay connected to the grid and also supply reactive currents to the grid to support the recovery from fault voltages. This paper presents a new fault detection method and inverter control scheme to improve the LVRT capability for full-scale permanent magnet synchronous generator (PMSG wind power systems. Fast fault detection can help the wind power systems maintain the DC-link voltage in a safe region. The proposed fault detection method is based on on-line adaptive parameter estimation. The performance of the proposed method is verified in comparison to the conventional voltage measurement method defined in the IEC 61400-21 standard.

  6. 基于SPMC75F2413A的小功率光伏并网系统的设计%Design of Grid Connected PV Inverted Control System Based on SPMC75F2413A

    Institute of Scientific and Technical Information of China (English)

    马红梅; 李鹏; 黄成玉

    2011-01-01

    提出了基于16位单片机SPMC75F2413A的光伏并网系统软硬件的设计方案,系统以SPMC75F2413A作为主控芯片来控制单相桥式逆变主电路.在实现太阳能电池最大功率点跟踪的同时,该系统能实时检测太阳能电池输出电压和电流、电网电压和负载电流,采用软件锁相技术使输出电压同步跟踪电网相电压的频率和相位.通过对光伏并网系统的测试表明:并网电压与电网相电压同频同相.实验结果验证了该系统的可行性和实用性.%A software and hardware design method of PV grid control system based on a 16-bit microcontroller SPMC75F2413A was proposed. The SPMC75F2413A chip is used as main control chip to control single-phase bridge inverter main circuit. The system can track maximum power point of PV panels simultaneously by detecting PV output voltage and current,grid voltage and load current, at the same time make frequency and phase of the inverter output voltage to track grid phase voltage's by the software PLL technique. Test results of simulation system show that grid-connected voltage is synchronization with grid phase voltage. Experimental results show the system is feasibility and practicality.

  7. Distribution-Agnostic Stochastic Optimal Power Flow for Distribution Grids

    Energy Technology Data Exchange (ETDEWEB)

    Baker, Kyri; Dall' Anese, Emiliano; Summers, Tyler

    2016-11-21

    This paper outlines a data-driven, distributionally robust approach to solve chance-constrained AC optimal power flow problems in distribution networks. Uncertain forecasts for loads and power generated by photovoltaic (PV) systems are considered, with the goal of minimizing PV curtailment while meeting power flow and voltage regulation constraints. A data- driven approach is utilized to develop a distributionally robust conservative convex approximation of the chance-constraints; particularly, the mean and covariance matrix of the forecast errors are updated online, and leveraged to enforce voltage regulation with predetermined probability via Chebyshev-based bounds. By combining an accurate linear approximation of the AC power flow equations with the distributionally robust chance constraint reformulation, the resulting optimization problem becomes convex and computationally tractable.

  8. Techno-economic feasibility of energy supply of remote villages in Palestine by PV-systems, diesel generators and electric grid

    Energy Technology Data Exchange (ETDEWEB)

    Mahmoud, Marwan M.; Ibrik, Imad H. [Energy Research Centre, An-Najah National University, Nablus, P.O. Box 721, West Bank (Palestine)

    2006-04-01

    As a contribution to the development program of rural areas in Palestine, this paper presents three energy supply alternatives for a remote village represented in PV system, diesel generator and electric grid. Design of these systems and the associated costs of their utilization are illustrated. A computer-aided dynamic economic evaluation method with five indicators is used to compare the economic-effectiveness of these energy systems. The results show that, utilizing of PV systems for rural electrification in Palestine is economically more feasible than using diesel generators or extension of the high voltage electric grid. The obtained results represents also a helpful reference for energy planers in Palestine and justify the consideration of PV systems more seriously. (author)

  9. Techno-economic feasibility of energy supply of remote villages in Palestine by PV-systems, diesel generators and electric grid (Case studies: Emnazeil and Atouf villages)

    Energy Technology Data Exchange (ETDEWEB)

    Ibrik, Imad [An-Najah National Univ., Nablus (PS). Energy Research Centre; Lecumberri, Marta

    2010-07-01

    The energy situation in Palestine is somewhat unique when compared to other countries in the Middle East. There are virtually no available natural resources, and due to the ongoing political situation, the Palestinians rely (or have to rely) almost totally on Israel for their energy needs. This paper presents three energy supply alternatives for a remote village represented in PV system, diesel generator and electric grid. Design of these systems and the associated costs of their utilization are illustrated. Economic evaluation methods are used to compare the economic-effectiveness of these energy systems. The results show that, utilizing of PV systems for rural electrification in Palestine is economically more useful than using diesel generators or extension of the high voltage electric grid. The obtained results represents also a helpful reference for energy planers in Palestine and justify the consideration of PV systems more seriously. (orig.)

  10. Operation of Power Grids with High Penetration of Wind Power

    Science.gov (United States)

    Al-Awami, Ali Taleb

    The integration of wind power into the power grid poses many challenges due to its highly uncertain nature. This dissertation involves two main components related to the operation of power grids with high penetration of wind energy: wind-thermal stochastic dispatch and wind-thermal coordinated bidding in short-term electricity markets. In the first part, a stochastic dispatch (SD) algorithm is proposed that takes into account the stochastic nature of the wind power output. The uncertainty associated with wind power output given the forecast is characterized using conditional probability density functions (CPDF). Several functions are examined to characterize wind uncertainty including Beta, Weibull, Extreme Value, Generalized Extreme Value, and Mixed Gaussian distributions. The unique characteristics of the Mixed Gaussian distribution are then utilized to facilitate the speed of convergence of the SD algorithm. A case study is carried out to evaluate the effectiveness of the proposed algorithm. Then, the SD algorithm is extended to simultaneously optimize the system operating costs and emissions. A modified multi-objective particle swarm optimization algorithm is suggested to identify the Pareto-optimal solutions defined by the two conflicting objectives. A sensitivity analysis is carried out to study the effect of changing load level and imbalance cost factors on the Pareto front. In the second part of this dissertation, coordinated trading of wind and thermal energy is proposed to mitigate risks due to those uncertainties. The problem of wind-thermal coordinated trading is formulated as a mixed-integer stochastic linear program. The objective is to obtain the optimal tradeoff bidding strategy that maximizes the total expected profits while controlling trading risks. For risk control, a weighted term of the conditional value at risk (CVaR) is included in the objective function. The CVaR aims to maximize the expected profits of the least profitable scenarios, thus

  11. A Novel Hybrid Model for Short-Term Forecasting in PV Power Generation

    Directory of Open Access Journals (Sweden)

    Yuan-Kang Wu

    2014-01-01

    Full Text Available The increasing use of solar power as a source of electricity has led to increased interest in forecasting its power output over short-time horizons. Short-term forecasts are needed for operational planning, switching sources, programming backup, reserve usage, and peak load matching. However, the output of a photovoltaic (PV system is influenced by irradiation, cloud cover, and other weather conditions. These factors make it difficult to conduct short-term PV output forecasting. In this paper, an experimental database of solar power output, solar irradiance, air, and module temperature data has been utilized. It includes data from the Green Energy Office Building in Malaysia, the Taichung Thermal Plant of Taipower, and National Penghu University. Based on the historical PV power and weather data provided in the experiment, all factors that influence photovoltaic-generated energy are discussed. Moreover, five types of forecasting modules were developed and utilized to predict the one-hour-ahead PV output. They include the ARIMA, SVM, ANN, ANFIS, and the combination models using GA algorithm. Forecasting results show the high precision and efficiency of this combination model. Therefore, the proposed model is suitable for ensuring the stable operation of a photovoltaic generation system.

  12. A Hybrid Power Control Concept for PV Inverters with Reduced Thermal Loading

    DEFF Research Database (Denmark)

    Yang, Yongheng; Wang, Huai; Blaabjerg, Frede

    2014-01-01

    on a single-phase PV inverter under yearly operation is presented with analyses of the thermal loading, lifetime, and annual energy yield. It has revealed the trade-off factors to select the power limit and also verified the feasibility and the effectiveness of the proposed control concept....

  13. Simulation and performance analysis of 110 kWp grid-connected photovoltaic system for residential building in India: A comparative analysis of various PV technology

    Directory of Open Access Journals (Sweden)

    Akash Kumar Shukla

    2016-11-01

    Full Text Available System simulation is necessary to investigate the feasibility of Solar PV system at a given location. This study is done to evaluate the feasibility of grid connected rooftop solar photovoltaic system for a residential Hostel building at MANIT, Bhopal, India (Latitude: 23° 16′ N, Longitude: 77° 36′ E. The study focuses on the use of Solargis PV Planner software as a tool to analyze the performance a 110 kWp solar photovoltaic rooftop plant and also compares the performances of different PV technologies based on simulated energy yield and performance ratio. Solargis proves to easy, fast, accurate and reliable software tool for the simulation of solar PV system.

  14. Wind and Solar on the Power Grid: Myths and Misperceptions, Greening the Grid (Spanish Version)

    Energy Technology Data Exchange (ETDEWEB)

    Authors: Denholm, Paul; Cochran, Jaquelin; Brancucci Martinez-Anido, Carlo

    2016-04-01

    This is the Spanish version of the 'Greening the Grid - Wind and Solar on the Power Grid: Myths and Misperceptions'. Wind and solar are inherently more variable and uncertain than the traditional dispatchable thermal and hydro generators that have historically provided a majority of grid-supplied electricity. The unique characteristics of variable renewable energy (VRE) resources have resulted in many misperceptions regarding their contribution to a low-cost and reliable power grid. Common areas of concern include: 1) The potential need for increased operating reserves, 2) The impact of variability and uncertainty on operating costs and pollutant emissions of thermal plants, and 3) The technical limits of VRE penetration rates to maintain grid stability and reliability. This fact sheet corrects misperceptions in these areas.

  15. Secondary Device Conifguration Principles of Grid-Connected Photovoltaic Power Station%并网型光伏电站二次设备配置原则

    Institute of Scientific and Technical Information of China (English)

    赵杰; 王硕; 刘鹏; 王竞; 杜冠男

    2015-01-01

    为研究并网型光伏电站二次设备配置情况,采用MATLAB/SIMULINK软件建立光伏并网发电系统模型,分析了其工作原理,并以某35 kV并网型光伏电站为例,对其二次设备配置进行了说明.实际运行表明,该配置规范、原理清晰、稳定可靠,为今后大规模光伏并网发电提供了参考依据.%In order to research on the secondary device conifguration of grid-connected photovoltaic (PV) power station, this paper adopted the software of Matlab/Simulink to build the model of grid-connected PV power system and analyzed its working principle. Taking certain 35kV grid-connected PV power station for example, this paper illustrated the conifguration of the secondary device. The actual operation shows that the conifguration has the clear principle with stability and reliability, which provides reference basis for the future large-scale PV grid-connected power generation.

  16. A Simple MPPT Algorithm for Novel PV Power Generation System by High Output Voltage DC-DC Boost Converter

    DEFF Research Database (Denmark)

    Sanjeevikumar, Padmanaban; Grandi, Gabriele; Wheeler, Patrick

    2015-01-01

    This paper presents the novel topology of Photo Voltaic (PV) power generation system with simple Maximum Power Point Tracking (MPPT) algorithm in voltage operating mode. Power circuit consists of high output voltage DC-DC boost converter which maximizes the output of PV panel. Usually traditional...... of DC-DC converters for PV integration. Hence, to overcome these difficulties this paper investigates a DC-DC boost converter together with the additional parasitic component within the circuit to provide high output voltages for maximizing the PV power generation. The proposed power system circuit...... substantially improves the high output-voltage by a simple MPPT closed loop proportional-integral (P-I) controller, and requires only two sensor for feedback needs. The complete numerical model of the converter circuit along with PV MPPT algorithm is developed in numerical simulation (Matlab/Simulink) software...

  17. Common mode behavior in grid connected DC and AC decoupled PV Inverter topologies

    Directory of Open Access Journals (Sweden)

    Sundar D. John

    2016-09-01

    Full Text Available The transformer-less grid connected inverters are gaining more popularity due to their high efficiency, very low ground leakage current and economic feasibility especially in photovoltaic systems. The major issue which surfaces these systems is that of common mode leakage current which arises due to the absence of an electrical transformer connected between the inverter and the utility grid. Several topologies have evolved to reduce the impact of common mode leakage current and a majority of them have succeeded in eliminating the impacts and have well kept them within the limits of grid standards. This paper compares and analyses the impact of the common mode leakage current for four popular inverter configurations through simulation of the topologies such as H5, H6, HERIC and FBZVR inverters.

  18. The advanced smart grid edge power driving sustainability

    CERN Document Server

    Carvallo, Andres

    2011-01-01

    Placing emphasis on practical ""how-to"" guidance, this cutting-edge resource provides you with a first-hand, insider's perspective on the advent and evolution of smart grids in the 21st century (smart grid 1.0). You gain a thorough understanding of the building blocks that comprise basic smart grids, including power plant, transmission substation, distribution, and meter automation. Moreover, this forward-looking volume explores the next step of this technology's evolution. It provides a detailed explanation of how an advanced smart grid incorporates demand response with smart appliances and

  19. Islanding detection technique using wavelet energy in grid-connected PV system

    Science.gov (United States)

    Kim, Il Song

    2016-08-01

    This paper proposes a new islanding detection method using wavelet energy in a grid-connected photovoltaic system. The method detects spectral changes in the higher-frequency components of the point of common coupling voltage and obtains wavelet coefficients by multilevel wavelet analysis. The autocorrelation of the wavelet coefficients can clearly identify islanding detection, even in the variations of the grid voltage harmonics during normal operating conditions. The advantage of the proposed method is that it can detect islanding condition the conventional under voltage/over voltage/under frequency/over frequency methods fail to detect. The theoretical method to obtain wavelet energies is evolved and verified by the experimental result.

  20. A High Performance PSO-Based Global MPP Tracker for a PV Power Generation System

    Directory of Open Access Journals (Sweden)

    Kuei-Hsiang Chao

    2015-07-01

    Full Text Available This paper aims to present an improved version of a typical particle swarm optimization (PSO algorithm, such that the global maximum power point (MPP on a P-V characteristic curve with multiple peaks can be located in an efficient and precise manner for a photovoltaic module array. A series of instrumental measurements are conducted on variously configured arrays built with SANYO HIP2717 PV modules, either unshaded, partially shaded, or malfunctioning, as the building blocks. There appear two, triple and quadruple peaks on the corresponding P-V characteristic curves. Subsequently, the tracking performance comparisons, made by some practical experiments, indicate the superiority of this improved MPP tracking algorithm over the typical one.

  1. Solar power in the red tape of grid operation regulations; Solarstrom im Knaeuel der Netzrichtlinien

    Energy Technology Data Exchange (ETDEWEB)

    Heup, Juergen

    2009-03-15

    The new medium-voltage regulation is a problem for the photovoltaics industry. While its implementation is technically feasible, more time will be required to achieve this. The PV industry has been successful in demanding transition periods. In the future, the PV industry should be more active in accompanying grid integration efforts. (orig.)

  2. Tracking the global maximum power point of PV arrays under partial shading conditions

    Science.gov (United States)

    Fennich, Meryem

    This thesis presents the theoretical and simulation studies of the global maximum power point tracking (MPPT) for photovoltaic systems under partial shading. The main goal is to track the maximum power point of the photovoltaic module so that the maximum possible power can be extracted from the photovoltaic panels. When several panels are connected in series with some of them shaded partially either due to clouds or shadows from neighboring buildings, several local maxima appear in the power vs. voltage curve. A power increment based MPPT algorithm is effective in identifying the global maximum from the several local maxima. Several existing MPPT algorithms are explored and the state-of-the-art power increment method is simulated and tested for various partial shading conditions. The current-voltage and power-voltage characteristics of the PV model are studied under different partial shading conditions, along with five different cases demonstrating how the MPPT algorithm performs when shading switches from one state to another. Each case is supplemented with simulation results. The method of tracking the Global MPP is based on controlling the DC-DC converter connected to the output of the PV array. A complete system simulation including the PV array, the direct current to direct current (DC-DC) converter and the MPPT is presented and tested using MATLAB software. The simulation results show that the MPPT algorithm works very well with the buck converter, while the boost converter needs further changes and implementation.

  3. Analysis on Common Mode Current of Single-Phase Grid-Connected PV System%单相光伏并网系统共模电流分析

    Institute of Scientific and Technical Information of China (English)

    杨秋霞; 高金玲; 荣雅君; 任玉艳

    2011-01-01

    Common mode current problem is very important to grid-connected photovoltaic (PV) system and in German standard DIN VDE 0126-1-1, the stipulations related to the common mode current are specified. When common mode current exceeds specified value, the connected PV generation system should be cut off within the stipulated time.Considering the importance of common mode current to the connection of photovoltaic generation to power grid, a common mode current is built. It is known throuth the analysis that common mode current is related to modulation technology and the position where the inductance locates. In allusion to above-mentioned features, a new single-phase grid-connected PV system that can suppress common mode current is designed.The designed system is a full-bridge single-phase gridconnected PV system with AC bypass circuit and in which inductances are symmetically arranged at both phase line and neutral line. Comparing with traditional full-bridge inverter systems adopting unipolar or bi-polar modulation technology,the structure of the proposed single-phase grid-connected PV system not only can eliminate common mode current produced in the grid-connected PV system, but also improve system efficiency and quality of current sent into power grid, thus the overall performance of the grid-connected PV system is improved. Results from theoretical analysis and simulation show that the proposed model and system are correct and available.%共模电流问题是光伏并网系统中的一个重要问题,德国DIN VDE 0126-1-1对共模电流做出了相关规定.当共模电流超过规定值时,系统必须在规定的时间内断开.考虑到共模电流在光伏并网系统中的重要性,建立了共模模型.通过分析可知,共模电流与调制技术和电感的安放位置相关.针对上述特点,设计了能够抑制共模电流的新型单相光伏并网系统,即带有交流旁路且电感对称分布在相线和中线上的全桥光伏并网系统.与传

  4. Lyapunov-Based Control Scheme for Single-Phase Grid-Connected PV Central Inverters

    NARCIS (Netherlands)

    Meza, C.; Biel, D.; Jeltsema, D.; Scherpen, J. M. A.

    2012-01-01

    A Lyapunov-based control scheme for single-phase single-stage grid-connected photovoltaic central inverters is presented. Besides rendering the closed-loop system globally stable, the designed controller is able to deal with the system uncertainty that depends on the solar irradiance. A laboratory p

  5. Monitoring and remote failure detection of grid-connected PV systems based on satellite observations

    NARCIS (Netherlands)

    Drews, A.; de Keizer, A.C.; Beyer, H.G.; Lorenz, E.; Betcke, J.W.H.; van Sark, W.G.J.H.M.; Heydenreich, W.; Wiemken, E.; Stettler, S.; Toggweiler, P.; Bofinger, S.; Schneider, M.; Heilscher, G.; Heinemann, D.

    2007-01-01

    Small grid-connected photovoltaic systems up to 5 kWp are often not monitored because advanced surveillance systems are not economical. Hence, some system failures which lead to partial energy losses stay unnoticed for a long time. Even a failure that results in a larger energy deficit can be diffic

  6. Lyapunov-Based Control Scheme for Single-Phase Grid-Connected PV Central Inverters

    NARCIS (Netherlands)

    Meza, C.; Biel, D.; Jeltsema, D.; Scherpen, J. M. A.

    2012-01-01

    A Lyapunov-based control scheme for single-phase single-stage grid-connected photovoltaic central inverters is presented. Besides rendering the closed-loop system globally stable, the designed controller is able to deal with the system uncertainty that depends on the solar irradiance. A laboratory p

  7. Soft-switching Grid-connected PV Inverter With Interleaved Flyback Topology

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The flyback topology has advantages of robustness and low cost and is proposed for 200-300 W class grid-connected photovoltaic inverter. However, the flyback converter is known for its low efficiency and low resolution control. Therefore, digitalized soft switching technique and algorithm are to be developed.

  8. A High Power Density DC-DC Converter for Distributed PV Architectures

    Energy Technology Data Exchange (ETDEWEB)

    Agamy, Mohammed S; Chi, Song; Elasser, Ahmed; Harfman-Todorovic, Maja; Jiang, Yan; Mueller, Frank; Tao, Fengfeng

    2012-06-01

    In order to maximize solar energy harvesting capabilities, power converters have to be designed for high efficiency and good MPPT and voltage/current performance. When many converters are used in distributed systems, power density also becomes an important factor as it allows for simpler system integration. In this paper a high power density string dc-dc converter suitable for distributed medium to large scale PV installation is presented. A simple partial power processing topology, implemented with all silicon carbide devices provides high efficiency as well as high power density. A 3.5kW, 100kHz converter is designed and tested to verify the proposed methods.

  9. Optimal control of a fuel cell/wind/PV/grid hybrid system with thermal heat pump load

    CSIR Research Space (South Africa)

    Sichilalu, S

    2016-10-01

    Full Text Available This paper presents an optimal energy management strategy for a grid-tied photovoltaic–wind-fuel cell hybrid power supply system. The hybrid system meets the load demand consisting of an electrical load and a heat pump water heater supplying thermal...

  10. Simulation Research on Large-scale PV Grid-connected Systems Based on MMC%基于模块化多电平换流器的大型光伏并网系统仿真研究

    Institute of Scientific and Technical Information of China (English)

    姚致清; 于飞; 赵倩; 张群

    2013-01-01

    In order to deal with the problem of large scale photovoltaic (PV) grid-connected systems, such as the low solar energy utilization rate, the great influence on power grids and so on, a new structure of large scale PV grid-connected systems based on modular multilevel converter (MMC) was proposed, in which a PV array was connected to a sub-module of MMC through a DC-DC circuit. In this system, DC voltage and AC voltage were controlled by the outer loop controller, the reference of PWM modulation was offered by the inner loop controller, active power and reactive power were controlled separately. The structure and control strategies of this system were introduced in detail in this paper, and a model of a 10 MWp PV grid-connected system was built in Simulink. The feasibility of the structure and the effectiveness of the control strategy are verified by time-domain simulations performed in Simulink, and the simulation results indicate that this system can raise the utilization ratio of solar energy, and can reduce the grid-connected harmonic contents.%为了解决大型光伏并网发电系统存在的光能利用率低、对电网影响大等问题,基于模块化多电平换流器(modular multilevel converter,MMC)提出一种新的大型光伏并网发电系统结构,即光伏阵列经DC-DC电路与模块化多电平换流器子模块相连,构成并网逆变系统;在该系统中,外环电压控制维持直流侧母线电压及交流侧电压稳定,内环电流控制为脉宽调制(pulse width modulation,PWM)提供参考波,有功无功独立控制。详细论述该系统的结构及其控制策略,并在Simulink中搭建10 MWp光伏发电系统模型。仿真结果验证了该系统结构的可行性及控制策略的有效性,同时也表明,该系统具有太阳能利用率高、并网谐波含量低等优势。

  11. Optimized Sizing, Selection, and Economic Analysis of Battery Energy Storage for Grid-Connected Wind-PV Hybrid System

    OpenAIRE

    Hina Fathima; K. Palanisamy

    2015-01-01

    Energy storages are emerging as a predominant sector for renewable energy applications. This paper focuses on a feasibility study to integrate battery energy storage with a hybrid wind-solar grid-connected power system to effectively dispatch wind power by incorporating peak shaving and ramp rate limiting. The sizing methodology is optimized using bat optimization algorithm to minimize the cost of investment and losses incurred by the system in form of load shedding and wind curtailment. The ...

  12. Mitigating the Detrimental Impacts of Solar PV Penetration on Electric Power Transmission Systems

    Science.gov (United States)

    Prakash, Nitin

    At present, almost 70% of the electric energy in the United States is produced utilizing fossil fuels. Combustion of fossil fuels contributes CO 2 to the atmosphere, potentially exacerbating the impact on global warming. To make the electric power system (EPS) more sustainable for the future, there has been an emphasis on scaling up generation of electric energy from wind and solar resources. These resources are renewable in nature and have pollution free operation. Various states in the US have set up different goals for achieving certain amount of electrical energy to be produced from renewable resources. The Southwestern region of the United States receives significant solar radiation throughout the year. High solar radiation makes concentrated solar power and solar PV the most suitable means of renewable energy production in this region. However, the majority of the projects that are presently being developed are either residential or utility owned solar PV plants. This research explores the impact of significant PV penetration on the steady state voltage profile of the electric power transmission system. This study also identifies the impact of PV penetration on the dynamic response of the transmission system such as rotor angle stability, frequency response and voltage response after a contingency. The light load case of spring 2010 and the peak load case of summer 2018 have been considered for analyzing the impact of PV. If the impact is found to be detrimental to the normal operation of the EPS, mitigation measures have been devised and presented in the thesis. Commercially available software tools/packages such as PSLF, PSS/E, DSA Tools have been used to analyze the power network and validate the results.

  13. Power control for wind turbines in weak grids: Concepts development

    DEFF Research Database (Denmark)

    Bindner, H.

    1999-01-01

    and analyze methods and technologies for making it viable to utilize more of the wind potential in remote areas. The suggestion is to develop a power control concept for wind turbines which will even out thepower fluctuations and make it possible to increase the wind energy penetration. The main options...... will make wind power more firm and possible to connect to weaker grids. So, when the concept is matured, theexpectation is that for certain wind power installations, the cost of the power control is paid back as added wind power capacity value and saved grid reinforcement costs. Different systems...... for controlling the power output from a wind farm connected to aweak grid have been investigated. The investigation includes development of different control strategies, use of different storage types, development of a framework for comparing different options and tools needed as part of the framework...

  14. Architecture of the Florida power grid as a complex network

    Science.gov (United States)

    Xu, Yan; Gurfinkel, Aleks Jacob; Rikvold, Per Arne

    2014-05-01

    We study the Florida high-voltage power grid as a technological network embedded in space. Measurements of geographical lengths of transmission lines, the mixing of generators and loads, the weighted clustering coefficient, as well as the organization of edge conductance weights show a complex architecture quite different from random-graph models usually considered. In particular, we introduce a parametrized mixing matrix to characterize the mixing pattern of generators and loads in the Florida Grid, which is intermediate between the random mixing case and the semi-bipartite case where generator-generator transmission lines are forbidden. Our observations motivate an investigation of optimization (design) principles leading to the structural organization of power grids. We thus propose two network optimization models for the Florida Grid as a case study. Our results show that the Florida Grid is optimized not only by reducing the construction cost (measured by the total length of power lines), but also through reducing the total pairwise edge resistance in the grid, which increases the robustness of power transmission between generators and loads against random line failures. We then embed our models in spatial areas of different aspect ratios and study how this geometric factor affects the network structure, as well as the box-counting fractal dimension of the grids generated by our models.

  15. The model and simulation of grid-connected PV based on switch function%基于开关函数的光伏并网发电建模与仿真

    Institute of Scientific and Technical Information of China (English)

    谢丽美

    2011-01-01

    采用两级式光伏并网发电系统,利用开关函数建模法,结合KCL和KVL定律导出其状态变量的微分方程,建立了光伏并网发电系统的整体数学模型;并采用相应的控制方法,搭建了包含光伏阵列、具有最大功率跟踪功能的升压斩波器、逆变器及其控制系统的并网光伏发电系统的仿真模型.%This paper adopted a bipolar grid-connected PV system, which used switching function model with KCL and KVL laws and educed it's differential equations; It adopted appropriate controlling methods and setted up simulation models including PV array, DC-DC convenor with the maxium power point tracking (MPPT), inverter and controlling system of the grid-connected PV system.

  16. Historically Large Geomagnetic Storms and Potential Electric Power Grid Impacts

    Science.gov (United States)

    Kappenman, J. G.

    2004-05-01

    While recent work has been done to examine the possible Dst Intensity of historically large geomagnetic storms, the impacts caused to modern day electric power grids from these storms occurs due to rapid rate-of-change of regional geomagnetic fields which in most cases are driven by large ionospheric electrojet current intensifications. These temporally and spatially dynamic disturbance morphologies are not well-characterized by Dst or other broad geomagnetic storm indices. For estimates of storm intensity that correctly scale the threat potential to electric power grids, it is necessary to describe the rate-of-change of geomagnetic field. The rate-of-change of the geomagnetic field (dB/dt usually measured in nT/min) creates at ground level a geoelectric field that causes the flow of geomagnetically-induced currents (GIC) through ground connection points in electric power grids. Therefore in general, the larger the dB/dt, the larger the resulting geo-electric field and GIC in exposed power grid infrastructures and the greater the operational impact these induced currents will have on the power grid. Both extensive modeling analysis and recent operational experience suggests that power grids are becoming more vulnerable to geomagnetic storms as they grow in size and complexity. Also, large power grid blackouts have occurred at relatively low geomagnetic storm intensities. For example, the regional disturbance intensity that triggered the Hydro Quebec collapse during the March 13, 1989 Superstorm only reached an intensity of 479 nT/min. Large numbers of power system impacts in the United States were also observed for intensities that ranged from 300 to 600 nT/min during this storm. Yet both recent and historical data indicate that storms with disturbance levels that range from 2000 nT/min to as much ~5000 nT/min may be possible over extensive regions at latitudes of concern for large continental power grids across North America and Europe. Large GIC have also been

  17. An AC/AC Direct Power Conversion Topology Having Multiple Power Grid Connections with Adjustable Loading

    DEFF Research Database (Denmark)

    Klumpner, Christian; Blaabjerg, Frede

    2004-01-01

    Normally, a power converter has one supply port to connect to the power grid and one or multiple output ports to connect to AC loads that require variable voltage and variable frequency. As the trend on the energy market is towards deregulation, new converter topologies are needed to allow...... independent producers/consumers to connect to multiple distribution grids in order to optimise the electricity price, as this will vary during the day from one power distribution company to another one. It will be needed to have a load that can smoothly adjust the power consumed from each power grid in order...... these fraction power will be a necessary feature on a deregulated energy market. This paper presents a new topology of a power converter based on the Direct Power Conversion concept, which is able to connect to multiple grids and provide complete decoupling between without circulating power between the grids...

  18. Power Control Flexibilities for Grid-Connected Multi-Functional Photovoltaic Inverters

    DEFF Research Database (Denmark)

    Yang, Yongheng; Blaabjerg, Frede; Wang, Huai

    2016-01-01

    and intelligent services, such as fault ride-through and reactive power compensation, is the key to attain higher utilisation of solar PV energy. Such functionalities for the future PV inverters can contribute to reduced cost of energy, and thus enable more cost-effective PV installations. To implement...

  19. Cascade Failure in a Phase Model of Power Grids

    Science.gov (United States)

    Sakaguchi, Hidetsugu; Matsuo, Tatsuma

    2012-07-01

    We propose a phase model to study cascade failure in power grids composed of generators and loads. If the power demand is below a critical value, the model system of power grids maintains the standard frequency by feedback control. On the other hand, if the power demand exceeds the critical value, an electric failure occurs via step out (loss of synchronization) or voltage collapse. The two failures are incorporated as two removal rules of generator nodes and load nodes. We perform direct numerical simulation of the phase model on a square lattice and a scale-free network and compare the results with a mean-field approximation.

  20. Grid converters for photovoltaic and wind power systems

    CERN Document Server

    Teodorescu, Remus; Rodríguez, Pedro

    2011-01-01

    "Grid Converters for Photovoltaic and Wind Power Systems provides a comprehensive description of the control of grid converters for photovoltaic and wind power systems. The authors present a range of control methods for meeting the latest application, power quality and power conversion requirements and standards, as well as looking towards potential future control functions. Practical examples, exercises, and an accompanying website with simulation models using Matlab and Simulink environments, and PSIM software make this text a pragmatic resource for electrical engineers as well as students taking related courses"--

  1. GRID : unlimited computing power on your desktop Conference MT17

    CERN Document Server

    2001-01-01

    The Computational GRID is an analogy to the electrical power grid for computing resources. It decouples the provision of computing, data, and networking from its use, it allows large-scale pooling and sharing of resources distributed world-wide. Every computer, from a desktop to a mainframe or supercomputer, can provide computing power or data for the GRID. The final objective is to plug your computer into the wall and have direct access to huge computing resources immediately, just like plugging-in a lamp to get instant light. The GRID will facilitate world-wide scientific collaborations on an unprecedented scale. It will provide transparent access to major distributed resources of computer power, data, information, and collaborations.

  2. Enhanced Efficiencies for High-Concentration, Multijunction PV Systems by Optimizing Grid Spacing under Nonuniform Illumination

    Directory of Open Access Journals (Sweden)

    Pratibha Sharma

    2014-01-01

    Full Text Available The design of a triple junction solar cell’s front contact grid can significantly affect cell conversion efficiency under high concentration. We consider one aspect of grid design, choosing a linear grid within a distributed resistance cell model to optimize finger spacings at concentrations between 500 and 2500 suns under uniform and nonuniform illumination. Optimization for maximum efficiency under Gaussian irradiance profiles is done by SPICE analysis. Relative to the optimized uniform illumination designs, we find enhancements of 0.5% to 2% in absolute efficiencies for uniform spacing. Efficiency enhancement with nonuniform spacing under nonuniform illumination is also evaluated. Our model suggests that, at lower concentrations (<1000 suns, the penalty for using uniformly spaced fingers instead of nonuniformly spaced fingers is <0.1%. However, at a concentration of 2500 suns the penalty increases to 0.3%. Thus, relative to a uniform irradiance optimization, an absolute efficiency increase of 2.3% can be attained for an optimized nonuniform spacing given the Gaussian irradiance profile under consideration.

  3. A wide-gap a-SiC:H PV-powered electrochromic window coating

    Energy Technology Data Exchange (ETDEWEB)

    Gao, W.; Lee, S.H.; Xu, Y.; Benson, D.K.; Deb, S.K.; Branz, H.M. [National Renewable Energy Lab., Golden, CO (United States)

    1998-09-01

    The authors report on the first monolithic, amorphous-silicon-based, photovoltaic-powered electrochromic window coating. The coating employs a wide bandgap a-Si{sub 1{minus}x}C{sub x}:H n-i-p photovoltaic (PV) cell as a semitransparent power supply, and a Li{sub y}WO{sub 3}/LiAlF{sub 4}/V{sub 2}O{sub 5} electrochromic (EC) device as an optical-transmittance modulator. The EC device is deposited directly on top of a PV cell that coats a glass substrate. The a-Si{sub 1{minus}x}C{sub x}:H PV cell has a Tauc gap of 2.2 eV and a transmittance of 60--80% over a large portion of the visible light spectrum. The authors reduced the thickness of the device to about 600 {angstrom} while maintaining a 1-sun open-circuit voltage of 0.9 V and short-circuit current of 2 mA/cm{sup 2}. The prototype 16 cm{sup 2} PV/EC device modulates the transmittance by more than 60% over a large portion of the visible spectrum. The coloring and bleaching times of the EC device are approximately 1 minute under normal operating conditions ({+-} 1 volt). A brief description of photoelectrochromic windows study is also given.

  4. Three-phase pv grid-connected system based on PR control and harmonic compensation%基于PR控制和谐波补偿的三相光伏并网系统

    Institute of Scientific and Technical Information of China (English)

    刘晓庆; 张代润; 谭波

    2012-01-01

    将电网电压定向矢量控制与比例谐振(PR)控制相结合的控制策略应用于三相光伏并网系统中,实现逆变器的并网控制.该控制策略比传统PI调节器的双闭环电网电压定向控制更简便,不需要复杂的坐标旋转变换和前馈解耦控制.同时,PR控制器可以很方便地实现并网电流低次谐波的补偿.仿真结果验证了该系统的结构和控制策略的有效性,可提高电网的电能质量.%The strategy of grid voltage oriented vector control combined with PR (proportional resonant) control is applied in three-phase photovoltaic grid-connected system to achieve the grid-connected of inverter. The grid voltage oriented control combined with PR control is easier compared with conventional double close-loop PI (proportional integral) control, without complex coordinate rotation and feedforward decoupling. PR controller could compensate low order harmonic of grid current easily. Simulation results verified the effective of PV grid-connected systerm and control strategy,could improve the power quality.

  5. Utilization of graph theory in security analysis of power grid

    Directory of Open Access Journals (Sweden)

    Dalibor Válek

    2014-12-01

    Full Text Available This paper describes way how to use graph theory in security analysis. As an environment is used network of power lines and devices which are included here. Power grid is considered as a system of nodes which make together graph (network. On the simple example is applied Fiedler´s theory which is able to select the most important power lines of whole network. Components related to these lines are logicly ordered and considered by author´s modified analysis. This method has been improved and optimalized for risks related with illegal acts. Each power grid component has been connected with possible kind of attack and every of this device was gradually evaluated by five coefficients which takes values from 1 to 10. On the coefficient basis was assessed the level of risk. In the last phase the most risky power grid components have been selected. On the selected devices have been proposed security measures.

  6. GridPACK™ : A Framework for Developing Power Grid Simulations on High-Performance Computing Platforms

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, Bruce J.; Perkins, William A.; Chen, Yousu; Jin, Shuangshuang; Callahan, David; Glass, Kevin A.; Diao, Ruisheng; Rice, Mark J.; Elbert, Stephen T.; Vallem, Mallikarjuna R.; Huang, Zhenyu

    2016-05-01

    This paper describes the GridPACK™ framework, which is designed to help power grid engineers develop modeling software capable of running on high performance computers. The framework makes extensive use of software templates to provide high level functionality while at the same time allowing developers the freedom to express whatever models and algorithms they are using. GridPACK™ contains modules for setting up distributed power grid networks, assigning buses and branches with arbitrary behaviors to the network, creating distributed matrices and vectors and using parallel linear and non-linear solvers to solve algebraic equations. It also provides mappers to create matrices and vectors based on properties of the network and functionality to support IO and to mana

  7. Decentralized Method for Load Sharing and Power Management in a PV/Battery Hybrid Source Islanded Microgrid

    DEFF Research Database (Denmark)

    Karimi, Yaser; Oraee, Hashem; Golsorkhi, Mohammad;

    2017-01-01

    This paper proposes a new decentralized power management and load sharing method for a photovoltaic based islanded microgrid consisting of various PV units, battery units and hybrid PV/battery units. Unlike the previous methods in the literature, there is no need to communication among the units...... and the proposed method is not limited to the systems with separate PV and battery units or systems with only one hybrid unit. The proposed method takes into account the available PV power and battery conditions of the units to share the load among them. To cover all possible conditions of the microgrid......, the operation of each unit is divided into five states and modified active power-frequency droop functions are used according to operating states. The frequency level is used as trigger for switching between the states. Efficacy of the proposed method in different load, PV generation and battery conditions...

  8. Sizing and Simulation of PV-Wind Hybrid Power System

    OpenAIRE

    Mustafa Engin

    2013-01-01

    A sizing procedure is developed for hybrid system with the aid of mathematical models for photovoltaic cell, wind turbine, and battery that are readily present in the literature. This sizing procedure can simulate the annual performance of different kinds of photovoltaic-wind hybrid power system structures for an identified set of renewable resources, which fulfills technical limitations with the lowest energy cost. The output of the program will display the performance of the system during t...

  9. Multiresonant Frequency-Locked Loop for Grid Synchronization of Power Converters Under Distorted Grid Conditions

    DEFF Research Database (Denmark)

    Rodriguez, Pedro; Luna, Alvaro; Candela, Ignacio;

    2011-01-01

    This paper presents a new multiresonant frequency-adaptive synchronization method for grid-connected power converters that allows estimating not only the positive- and negative-sequence components of the power signal at the fundamental frequency but also other sequence components at other harmoni...

  10. 50 kWp并网光伏实验电站的综合设计、搭建与运行%Integrated design and construction and operation of 50 kW p grid-connected PV station

    Institute of Scientific and Technical Information of China (English)

    郭永庆; 陈来军; 司杨; 黄少伟; 陈晓弢; 梅生伟

    2016-01-01

    To confirm actual performance of new photovoltaic devices and key factors affecting the ef-ficiency of PV system, 50 kWp grid-connected PV power station that integrated a variety of photo-voltaic devices and installation methods was designed and built. Based on actual operating data, the power generation of PV arrays that installed different PV modules, inverters and smart optimizer un-der different meteorological conditions was compared. Furthermore, the influence of radiation on the power generation was analyzed. The results show that the bifacial PV module has the best output performance and its power generation is higher than other PV modules. Smart optimizer has less effect on PV system with no shadows, while small capacity inverter can reduce the influence of dif-ferent PV modules and increase the total power generation. Moreover the actual output of polycrystal-line silicon solar cell is most stable in various types of photovoltaic module under the influence of so-lar irradiance variations. Comprehensive research results show that polycrystalline silicon solar cell and bifacial PV module have a great advantage in the application of grid connected photovoltaic pow-er generation system.%为深入研究新型光伏器件的实际性能及影响光伏电站发电效率的关键性因素,设计并建成一座多种光伏设备组合交叉安装的50 kWp并网光伏实验电站。根据电站实际运行数据,对比了不同气象条件下光伏阵列选用不同类型组件、智能优化器以及不同容量逆变器的发电状况,分析了辐射量变化对光伏电站发电量的影响。结果表明:各类型光伏组件中双面电池输出特性表现最佳,其发电量高于其他类型组件;对于无阴影遮挡的光伏发电系统,智能优化器的作用得不到有效发挥;采用较小容量逆变器可减少太阳能电池组串模块间的差异性带来的影响,增大光伏阵列总发电量;受太阳辐照度变化影响

  11. For the Grid and Through the Grid: The Role of Power Line Communications in the Smart Grid

    CERN Document Server

    Galli, Stefano; Wang, Zhifang

    2010-01-01

    Is Power Line Communication (PLC) a good candidate for Smart Grid applications? The objective of this paper is to address this important question. To do so we provide an overview of what PLC can deliver today by surveying its history and describing the most recent technological advances in the area. We then address Smart Grid applications as instances of sensor networking and network control problems and discuss the main conclusion one can draw from the literature on these subjects. The application scenario of PLC within the Smart Grid is then analyzed in detail. Since a necessary ingredient of network planning is modeling, we also discuss two aspects of engineering modeling that relate to our question. The first aspect is modeling the PLC channel through fading models. The second aspect we review is the Smart Grid control and traffic modeling problem which allows us to achieve a better understanding of the communications requirements. Finally, this paper reports recent studies on the electrical and topologic...

  12. Off-grid power quality: Impacts, analysis and solutions

    Science.gov (United States)

    Gautam, Arjun

    Good power quality is a critical factor for the reliable operation of electrical loads in a power system. However, the current drawn by many electronic devices and non-linear loads are non-sinusoidal, which can result in a poor power quality, particularly in off-grid power systems. Poor power quality is characterized by electrical disturbances such as transients, sags, swells, harmonics and even interruptions in the power supply. Off-grid power systems worldwide struggle with system failures and equipment damage due to poor power quality. To better understand off-grid system failures and equipment damage issues, the current and voltage characteristics of a number of electrical devices in two off-grid homes, one using a pure sine wave inverter and the other using a modified sine wave inverter, were recorded with a Fluke 43B power quality analyzer, and the devices' impact on the power quality of the off-grid systems was analyzed. The off-grid power quality data were then compared with data from a grid-connected apartment, to help identify the issues that were specific to off-grid systems. The MATLAB/Simulink software was used to model and analyze power quality for additional configurations of the two off-grid systems mentioned above. Strategies to mitigate the worst power quality issues were selected based upon their function and cost, and a few were tested in an off-grid system. Selection of an inverter was found to be important because not all devices are supported by each type of inverter. For example, the refrigerator in the off-grid home with a modified sine wave inverter produced a significant amount of current and voltage harmonics far above standards. In fact, this type of inverter does not support a number of sensitive devices including motors, refrigerators, microwave ovens, fluorescent lights, battery chargers etc. The major issues for the degradation of power quality in the off-grid system using a pure sine wave inverter were the current harmonics

  13. Research on Safety and Stability of Regional Power Grids to the Year 2020

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The safety and stability study on Northeast, North, East, Northwest and Central China power grids had been carried out, which provided technical supports to planning design of regional power grids. By analyzing safety and stability under severe faults in regional power grids, revealed weaknesses on power grid configurations and measures for preventing from loss of stability were presented. In comparison of various schemes of power system safety and stability among parts of power grids, more than two recommended schemes can be chosen as reference in planning design for regional power grids. Considering the safety and stability control measures necessary for each power grids, it is believed the trunk networks of all power grids can fulfill the third criteria of Guideline for Power System Safety and Stability, while the weakness and predominated hydropower may deteriorate safety and stability of power grids. The power grid shall be regulated in line with the variation of boundary conditions.

  14. Residential Solar PV Planning in Santiago, Chile: Incorporating the PM10 Parameter

    Directory of Open Access Journals (Sweden)

    Gustavo Cáceres

    2014-12-01

    Full Text Available This paper addresses an economic study of the installation of photovoltaic (PV solar panels for residential power generation in Santiago, Chile, based on the different parameters of a PV system, such as efficiency. As a performance indicator, the Levelized Cost of Energy (LCOE was used, which indicates the benefit of the facility vs. the current cost of electrical energy. In addition, due to a high level of airborne dusts typically associated with PM10, the effect of the dust deposition on PV panels’ surfaces and the effect on panel performance are examined. Two different scenarios are analyzed: on-grid PV plants and off-grid PV plants.

  15. A Novel Grid-connected PV System Based on MMC%一种新型模块化多电平光伏并网系统

    Institute of Scientific and Technical Information of China (English)

    荣飞; 刘诚; 黄守道

    2015-01-01

    In order to solve the low efficiency and serious impaction on public grid of PV system under partial shading, this paper proposed a novel PV (Photovoltaic) topology and its control method based on modular multilevel converter (MMC). The novel topology connects a PV module to the capacitor of each sub-module (PM) of MMC in parallel. When there is a partial shading, the maximum power can be achieved by regulating each PM’s capacitor voltage to the maximum power point voltage without additional hardware cost. Based on the novel topology, the maximum power tracking control, redundancy control, voltage stable control and grid-connected control were studied carefully. Compared to the traditional series topology, the proposed topology has the advantage of relatively less hardware investment, low harmonic content, high solar energy utilization and so on. At the same time, its strong fault-tolerant ability can ensure the reliable operation of the system. The simulation model of the system by MATLAB and experimentation were realized to verify its effectiveness.%为了解决光伏并网系统存在的光能利用率低、对电网影响大等问题,提出一种新型模块化多电平(modular multilevel converter,MMC)光伏并网系统及其控制方法,即在级联式MMC的主电路结构中,对每一个子模块电容并联一块光伏组件,在不增加额外硬件成本的基础上,仅通过控制方法实现局部阴影条件下每个光伏组件的最大功率点跟踪(maximum power point tracking,MPPT)。其控制方法包括MPPT控制、冗余模块控制、稳压控制和并网控制。详细论述该系统的结构及其控制策略,并在 Simulink 中搭建系统模型。该系统具有硬件相对投入少、谐波含量低、太阳能利用率高等优势。同时,在光伏组件出现故障时能及时进行容错处理,保证了系统的可靠运行。仿真实验结果验证了该系统及其控制策略的可行性。

  16. Grid Monitoring and Advanced Control of Distributed Power Generation Systems

    DEFF Research Database (Denmark)

    Timbus, Adrian Vasile

    . First part of the thesis investigates possible algorithms for fast and accurate identi cation of utility network variables such as voltage amplitude, frequency, phase angle and line impedance. Special attention has been paid to grid synchronization algorithm in terms of accurate estimation of grid...... of grid voltage and the frequency of utility network. As a result, fast and accurate identi cation of both variables has been achieved. In addition, positive and negative sequence components of grid voltage can also be calculated. Simple, yet powerful ltering techniques, based on second order generalized...... integrator (SOGI) and delay signal cancellation (DSC) have been used to separate the sequence components. Simulation and experimental results attest the accuracy and e ectiveness of the developed algorithms in identifying the frequency, phase angle and magnitude of grid voltages during severe distortions...

  17. Grid-connected Technology for Two Stages Hybrid PV-wind Generation System with Double Input%采用双输入两级式风光互补发电的并网技术

    Institute of Scientific and Technical Information of China (English)

    於锋; 胡国文

    2011-01-01

    A new Buck/Buck-Boost DC chopper circuit for hybrid PV-wind generation system is proposed and variable step perturbation method is used to achieve the maximum power point tracking (MPPT) on the basis of the proposed circuit. Grid-connected side, a new design method of grid-connected combinating dynamic reactive power compensation and active power filter is presented which based onip-iq current detection method of instaneous reactive power theory.From the simulation results, it is demonstrated that the proposed DC chopper circuit is enable to achieve the MPPT of the input side on the power system isimultaneously or individually. The proposed grid-connected scheme can achieve hybrid PV-wind generation and can also improve power quality effectively.%提出了一种新颖的供风光互补发电系统发电侧输入的升降压直流斩波电路.在该电路基础上,通过变步长扰动法实现对系统的最大功率点跟踪(MPPT).在其并网侧,基于瞬时无功理论的i-i电流检测法,成功实现了具有动态无功补偿、有源滤波功能的并网发电技术.仿真结果表明,所设计的直流斩波电路能够同时或独立地对发电系统输入端进行MPPT,所提出的并网方案在实现风光互补并网发电的同时,有效改善了电能质量.

  18. FC/PV Fed SAF with Fuzzy Logic Control for Power Quality Enhancement

    Directory of Open Access Journals (Sweden)

    R. Balamurugan

    2015-02-01

    Full Text Available In this paper, a Fuel cell (FC / Photovoltaic cell (PV/ Battery operated three phase Shunt Active power Filter (SAF is proposed for improving the power quality at the utility side. Fuzzy based instantaneous p-q theory control is proposed for SAF. This SAF consists of Voltage Source PWM Converter (VSC and a DC link capacitor supplied by a FC/PV/Battery. The filter provides harmonic mitigation with reactive power compensation and neutral compensation for loads at the Point of Common Coupling (PCC. A Single switch boost DC-DC converter connects the FC/PV/Battery with the VSC to maintain the load. The performance of the proposed SAF is tested in MATLAB / SIMULINK environment with Fuzzy logic controller (FLC. The controller maintains the DC link voltage based on the current reference generated by the p-q theory. The Hysteresis PWM current controller is employed to generate the gating pulses to the switches in VSC. The simulation results of the proposed SAF validate the effectiveness of FLC in power quality enhancement.

  19. A Buck-Boost Converter Modified to Utilize 600V GaN Power Devices in a PV Application Requiring 1200V Devices

    OpenAIRE

    2015-01-01

    This paper presents a buck-boost converter which is modified to utilize new 600 V gallium nitride (GaN) power semiconductor devices in an application requiring 1200 V devices. The presented buck-boost converter is used as a part of a dc/dc stage in an all-GaN photovoltaic (PV) inverter and it provides a negative voltage for the 3-level neutral-point-clamped (NPC) PWM inverter which is connected to the utility grid. Since in this application the transistor and the diode of ...

  20. Benchmarking of Constant Power Generation Strategies for Single-Phase Grid-Connected Photovoltaic Systems

    DEFF Research Database (Denmark)

    Sangwongwanich, Ariya; Yang, Yongheng; Blaabjerg, Frede

    2018-01-01

    strategies based on: 1) a power control method (P-CPG), 2) a current limit method (I-CPG) and 3) the Perturb and Observe algorithm (P&O-CPG). However, the operational mode changes (e.g., from the maximum power point tracking to a CPG operation) will affect the entire system performance. Thus, a benchmarking...... of the presented CPG strategies is also conducted on a 3-kW single-phase grid-connected PV system. Comparisons reveal that either the P-CPG or I-CPG strategies can achieve fast dynamics and satisfactory steady-state performance. In contrast, the P&O-CPG algorithm is the most suitable solution in terms of high...... active power control methods are required. As a cost-effective solution to avoid overloading, a Constant Power Generation (CPG) control scheme by limiting the feed-in power has been introduced into the currently active grid regulations. In order to achieve a CPG operation, this paper presents three CPG...

  1. Benchmarking of Constant Power Generation Strategies for Single-Phase Grid-Connected Photovoltaic Systems

    DEFF Research Database (Denmark)

    Sangwongwanich, Ariya; Yang, Yongheng; Blaabjerg, Frede

    2016-01-01

    strategies based on: 1) a power control (P-CPG), 2) a current limit method (I-CPG) and 3) the Perturb and Observe algorithm (P&O-CPG). However, the operational mode changes (e.g., from the maximum power point tracking to a CPG operation) will affect the entire system performance. Thus, a benchmarking...... of the proposed CPG strategies is also conducted on a 3-kW single-phase grid-connected PV system. Comparisons reveal that either the P-CPG or I-CPG strategies can achieve fast dynamics and satisfactory steady-state performance. In contrast, the P&OCPG algorithm is the most suitable solution in terms of high...... active power control methods are required. As a cost-effective solution to avoid overloading, a Constant Power Generation (CPG) control scheme by limiting the feed-in power has been introduced into the currently active grid regulations. In order to achieve a CPG operation, this paper proposes three CPG...

  2. Augmented Nonlinear Controller for Maximum Power-Point Tracking with Artificial Neural Network in Grid-Connected Photovoltaic Systems

    Directory of Open Access Journals (Sweden)

    Suliang Ma

    2016-11-01

    Full Text Available Photovoltaic (PV systems have non-linear characteristics that generate maximum power at one particular operating point. Environmental factors such as irradiance and temperature variations greatly affect the maximum power point (MPP. Diverse offline and online techniques have been introduced for tracking the MPP. Here, to track the MPP, an augmented-state feedback linearized (AFL non-linear controller combined with an artificial neural network (ANN is proposed. This approach linearizes the non-linear characteristics in PV systems and DC/DC converters, for tracking and optimizing the PV system operation. It also reduces the dependency of the designed controller on linearized models, to provide global stability. A complete model of the PV system is simulated. The existing maximum power-point tracking (MPPT and DC/DC boost-converter controller techniques are compared with the proposed ANN method. Two case studies, which simulate realistic circumstances, are presented to demonstrate the effectiveness and superiority of the proposed method. The AFL with ANN controller can provide good dynamic operation, faster convergence speed, and fewer operating-point oscillations around the MPP. It also tracks the global maxima under different conditions, especially irradiance-mutating situations, more effectively than the conventional methods. Detailed mathematical models and a control approach for a three-phase grid-connected intelligent hybrid system are proposed using MATLAB/Simulink.

  3. Design of smart power grid renewable energy systems

    CERN Document Server

    Keyhani, Ali

    2011-01-01

    To address the modeling and control of smart grid renewable energy system into electric power systems, this book integrates three areas of electrical engineering: power system engineering, control systems engineering and power electronics  The approach to the integration of these three areas differs from classical methods. Due to complexity of this task, the author has decided to present the basic concepts, and then present a simulation test bed in matlab to use these concepts to solve a basic problem in development of smart grid energy system. Therefore, each chapter has three parts: first a

  4. Active current control in wind power plants during grid faults

    DEFF Research Database (Denmark)

    Martinez, Jorge; Kjær, Phillip C.; Rodriguez, Pedro

    2010-01-01

    , wind turbines usually have solutions that enable the turbines to control the generation of reactive power during faults. This paper addresses the importance of using an optimal injection of active current during faults in order to fulfil these grid codes. This is of relevant importance for severe......Modern wind power plants are required and designed to ride through faults in electrical networks, subject to fault clearing. Wind turbine fault current contribution is required from most countries with a high amount of wind power penetration. In order to comply with such grid code requirements...

  5. Cyber physical systems approach to smart electric power grid

    CERN Document Server

    Khaitan, Siddhartha Kumar; Liu, Chen Ching

    2015-01-01

    This book documents recent advances in the field of modeling, simulation, control, security and reliability of Cyber- Physical Systems (CPS) in power grids. The aim of this book is to help the reader gain insights into working of CPSs and understand their potential in transforming the power grids of tomorrow. This book will be useful for all those who are interested in design of cyber-physical systems, be they students or researchers in power systems, CPS modeling software developers, technical marketing professionals and business policy-makers.

  6. The Next-Generation Power Electronics Technology for Smart Grids

    Science.gov (United States)

    Akagi, Hirofumi

    This paper presents an overview of the next-generation power electronics technology for the Japanese-version smart grid. It focuses on a grid-level battery energy storage system, a grid-level STATCOM (STATic synchronous COMpensator), and a 6.6-kV BTB (Back-To-Back) system for power flow control between two power distribution feeders. These power electronic devices play an important role in achieving load frequency control and voltage regulation. Their circuit configurations based on modular multilevel cascade PWM converters are characterized by flexible system design, low voltage steps, and low EMI (Electro-Magnetic Interference) emission. Their downscaled laboratory models are designed, constructed, and tested to verify the viability and effectiveness of the circuit configurations and control methods.

  7. Low Voltage Ride-Through of Two-Stage Grid-Connected Photovoltaic Systems Through the Inherent Linear Power-Voltage Characteristic

    DEFF Research Database (Denmark)

    Yang, Yongheng; Sangwongwanich, Ariya; Liu, Hongpeng

    2017-01-01

    In this paper, a cost-effective control scheme for two-stage grid-connected PhotoVoltaic (PV) systems in Low Voltage Ride-Through (LVRT) operation is proposed. In the case of LVRT, the active power injection by PV panels should be limited to prevent from inverter over-current and also energy...... aggregation at the dc-link, which will challenge the dc-link capacitor lifetime if remains uncontrolled. At the same time, reactive currents should be injected upon any demand imposed by the system operators. In the proposed scheme, the two objectives can be feasibly achieved. The active power is regulated...... automatically through a proportional controller according to the voltage sag level and PV inherent characteristics (i.e., the voltage and power droop). Compared to prior-art LVRT schemes, the proposed method is cost-effective, as it is achieved by simply plugging the proportional controller into a maximum power...

  8. Design and evaluation of hybrid wind/PV/diesel power systems for Brazilian applications

    Energy Technology Data Exchange (ETDEWEB)

    McGowan, J.G.; Manwell, J.F.; Avelar, C. [Univ. of Massachusetts, Amherst, MA (United States); Warner, C. [National Renewable Energy Lab., Golden, CO (United States)

    1996-12-31

    This paper presents a summary of a study centered on the design and evaluation of hybrid wind/PV/diesel systems for remote locations in Brazil. The objective of this work was to evaluate high reliability hybrid power systems that have been designed for the lowest life cycle costs. The technical and economic analysis of the hybrid wind/PV/diesel systems was carried out using HYBRID2, a computational code developed at the University of Massachusetts in conjunction with the National Renewable Energy Laboratory (NREL). After a summary of a generalized design procedure for such systems based on the use of this code, a systematic parametric evaluation of a representative design case for a village power system in Brazil is presented. As summarized in the paper, the performance and economic effects of key design parameters are illustrated. 8 refs., 10 figs.

  9. A Novel Design and Optimization Software for Autonomous PV/Wind/Battery Hybrid Power Systems

    Directory of Open Access Journals (Sweden)

    Ali M. Eltamaly

    2014-01-01

    Full Text Available This paper introduces a design and optimization computer simulation program for autonomous hybrid PV/wind/battery energy system. The main function of the new proposed computer program is to determine the optimum size of each component of the hybrid energy system for the lowest price of kWh generated and the best loss of load probability at highest reliability. This computer program uses the hourly wind speed, hourly radiation, and hourly load power with several numbers of wind turbine (WT and PV module types. The proposed computer program changes the penetration ratio of wind/PV with certain increments and calculates the required size of all components and the optimum battery size to get the predefined lowest acceptable probability. This computer program has been designed in flexible fashion that is not available in market available software like HOMER and RETScreen. Actual data for Saudi sites have been used with this computer program. The data obtained have been compared with these market available software. The comparison shows the superiority of this computer program in the optimal design of the autonomous PV/wind/battery hybrid system. The proposed computer program performed the optimal design steps in very short time and with accurate results. Many valuable results can be extracted from this computer program that can help researchers and decision makers.

  10. Investigation of power values of PV rooftop systems based on heat gain reduction

    Science.gov (United States)

    Chenvidhya, Tanokkorn; Seapan, Manit; Parinya, Panom; Wiengmoon, Buntoon; Chenvidhya, Dhirayut; Songprakorp, Roongrojana; Limsakul, Chamnan; Sangpongsanont, Yaowanee; Tannil, Nittaya

    2015-09-01

    PV rooftop system can generally be installed to produce electricity for the domestic house, office, small enterprise as well as factory. Such a system has direct useful for reducing peak load, meanwhile it also provides shaded area on the roof and hence the heat gain into the building is reduced. This study aims to investigate the shading effect on reduction of heat transfer into the building. The 49 kWp of PV rooftop system has been installed on the deck of the office building located in the middle of Thailand where the latitude of 14 ° above the equator. The estimation of heat gain into the building due to the solar irradiation throughout a day for one year has been carried out, before and after the installation of the PV rooftop system. Then the Newton's law of cooling is applied to calculate the heat gain. The calculation and the measurement of the heat reduction are compared. Finally, the indirect benefit of the PV rooftop system installed is evaluated in terms of power value.

  11. Alternative energies. Sahara Power needs pan-European grid operator

    Energy Technology Data Exchange (ETDEWEB)

    Van Wijland, G.

    2009-09-15

    A consortium of leading European - mostly German - companies plans to invest 400 billion euros in a megaproject to generate solar power in the Sahara desert. Desertec, as the project is called, could cover 15 percent of European electricity demand. The problem is, how do you transport this power to Paris and Berlin? It can only work with a pan-European grid operator.

  12. Using Heat Pump Energy Storages in the Power Grid

    DEFF Research Database (Denmark)

    Pedersen, Tom S.; Andersen, Palle; Nielsen, Kirsten M.

    2011-01-01

    The extensive growth of installed wind energy plants lead to increasing balancing problems in the power grid due to the nature of wind fields and diurnal variations in consumption. One way to overcome these problems is to move consumption to times where wind power otherwise cause overproduction...

  13. Wide-area situation awareness in electric power grid

    Energy Technology Data Exchange (ETDEWEB)

    Greitzer, Frank L.

    2010-04-28

    Two primary elements of the US energy policy are demand management and efficiency and renewable sources. Major objectives are clean energy transmission and integration, reliable energy transmission, and grid cyber security. Development of the Smart Grid seeks to achieve these goals by lowering energy costs for consumers, achieving energy independence and reducing greenhouse gas emissions. The Smart Grid is expected to enable real time wide-area situation awareness (SA) for operators. Requirements for wide-area SA have been identified among interoperability standards proposed by the Federal Energy Regulatory Commission and the National Institute of Standards and Technology to ensure smart-grid functionality. Wide-area SA and enhanced decision support and visualization tools are key elements in the transformation to the Smart Grid. This paper discusses human factors research to promote SA in the electric power grid and the Smart Grid. Topics that will be discussed include the role of human factors in meeting US energy policy goals, the impact and challenges for Smart Grid development, and cyber security challenges.

  14. A Wavelet-Based Unified Power Quality Conditioner to Eliminate Wind Turbine Non-Ideality Consequences on Grid-Connected Photovoltaic Systems

    Directory of Open Access Journals (Sweden)

    Bijan Rahmani

    2016-05-01

    Full Text Available The integration of renewable power sources with power grids presents many challenges, such as synchronization with the grid, power quality problems and so on. The shunt active power filter (SAPF can be a solution to address the issue while suppressing the grid-end current harmonics and distortions. Nonetheless, available SAPFs work somewhat unpredictably in practice. This is attributed to the dependency of the SAPF controller on nonlinear complicated equations and two distorted variables, such as load current and voltage, to produce the current reference. This condition will worsen when the plant includes wind turbines which inherently produce 3rd, 5th, 7th and 11th voltage harmonics. Moreover, the inability of the typical phase locked loop (PLL used to synchronize the SAPF reference with the power grid also disrupts SAPF operation. This paper proposes an improved synchronous reference frame (SRF which is equipped with a wavelet-based PLL to control the SAPF, using one variable such as load current. Firstly the fundamental positive sequence of the source voltage, obtained using a wavelet, is used as the input signal of the PLL through an orthogonal signal generator process. Then, the generated orthogonal signals are applied through the SRF-based compensation algorithm to synchronize the SAPF’s reference with power grid. To further force the remained uncompensated grid current harmonics to pass through the SAPF, an improved series filter (SF equipped with a current harmonic suppression loop is proposed. Concurrent operation of the improved SAPF and SF is coordinated through a unified power quality conditioner (UPQC. The DC-link capacitor of the proposed UPQC, used to interconnect a photovoltaic (PV system to the power grid, is regulated by an adaptive controller. Matlab/Simulink results confirm that the proposed wavelet-based UPQC results in purely sinusoidal grid-end currents with total harmonic distortion (THD = 1.29%, which leads to high

  15. A Study of Dynamic Interaction Between PV Grid-connected Inverters and Grid Based on the Impedance Analysis Method%基于阻抗分析法研究光伏并网逆变器与电网的动态交互影响

    Institute of Scientific and Technical Information of China (English)

    陈新; 张旸; 王赟程

    2014-01-01

    大量存在的并网逆变器会对分布式发电系统的电能质量和系统稳定性造成深刻影响,该文基于阻抗分析方法研究光伏并网逆变器与电网间的交互影响。论文定量分析光伏并网逆变器与电网之间由于阻抗交互影响所产生的谐波振荡,并通过基于硬件在环的分布式发电综合实验平台验证不同电网接入条件对并网逆变器稳定性的影响;推导LCL型并网逆变器的系统阻抗模型,并提出一种基于电压前馈的主动阻抗控制策略来提高逆变器与电网之间的稳定相角裕度,使光伏并网逆变器在不同的动态电网条件下均具有较好的控制鲁棒性;最后给出阻抗主动调整控制策略的设计过程和参数设计方法,并通过仿真验证主动阻抗控制策略的有效性。%The power quality and system stability in Distributed Generation (DG) systems are important issues with the far-ranging application of grid-connected inverters. The study of the dynamic interaction between PV Grid-Connected inverters and the grid based on impedance analysis was presented in this paper. The harmonic resonance due to the impedance interaction between PV inverters and the grid was analyzed in quantity, and the effect of the grid impedance on the stability of PV inverters was evaluated through the hardware-in-loop DG test-bed system. The impedance modeling of LCL type PV inverter was derived in the paper. In order to increase the phase margin of the impedance ratio, a novel active impedance control was proposed, which is beneficial to improve control robustness of PV inverters under different grid impedance conditions. The operation principle and design of the active impedance control were depicted, and the control performance was verified by the simulation evaluation.

  16. Driving Energy System Transformation with "Vehicle-to-Grid" Power

    OpenAIRE

    Moura, F

    2006-01-01

    Today's electricity and transport systems face a number of challenges related to reliability, security and environmental sustainability. New technologies may provide a means by which to overcome some of these challenges, yet many such technologies are confronted with substantial technical or commercial hurdles. This report explores one promising technology, "Vehicle-to-Grid" (V2G) power generation, whereby parked Electric-Drive Vehicles (EDVs) are used to provide electricity to the grid. EDV...

  17. Methods and Strategies for Overvoltage Prevention in Low Voltage Distribution Systems with PV

    DEFF Research Database (Denmark)

    Hashemi Toghroljerdi, Seyedmostafa; Østergaard, Jacob

    2016-01-01

    , the overvoltage caused by high PV penetration is described, solutions to facilitate higher PV penetration are classified, and their effectiveness, advantages, and disadvantages are illustrated. The investigated solutions include the grid reinforcement, electrical energy storage application, reactive power......The rapid development of photovoltaic (PV) systems in electrical grids brings new challenges in the control and operation of power systems. A considerable share of already installed PV units are small-scale units, usually connected to low voltage (LV) distribution systems that were not designed...... to handle a high share of PV power. This paper provides an in-depth review of methods and strategies proposed to prevent overvoltage in LV grids with PV, and discusses the effectiveness, advantages, and disadvantages of them in detail. Based on the mathematical framework presented in the paper...

  18. Photovoltaic (PV) building design guide. Collection of worldwide cases of photovoltaic power generation buildings; PV kenchiku design guide. Sekai no taiyoko hatsuden kenchiku jireishu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-09-20

    This paper notices design possibility of PV buildings, and describes attempts to grasp the building integrated PV (BIPV) system in terms of total building design. The paper sets the principal object in providing photographs, specifications, and design data of the cases especially excellent in design sense, wherein, among the buildings adopting the photovoltaic power generation system, the handling of solar cell panels is integrated with the design of the building. Symbolic significance possessed by building patterns is great, and the symbolism and message expression over the environment are the important interests. Working on the BIPV from these viewpoints requires a number of hints in the design aspects, not to speak of the fundamental knowledge about photovoltaic power generation. This paper is intended to present the minimum necessary fundamental knowledge about PV systems, introduce excellent actual examples that can call for attention to photovoltaic power generation systems, and provide clues to proceeding to the next step toward the introduction thereof. The cases introduced in the paper include 36 PV cases in overseas countries, and 15 cases in Japan. (NEDO)

  19. Hybrid PV/Wind Power Systems Incorporating Battery Storage and Considering the Stochastic Nature of Renewable Resources

    Science.gov (United States)

    Barnawi, Abdulwasa Bakr

    Hybrid power generation system and distributed generation technology are attracting more investments due to the growing demand for energy nowadays and the increasing awareness regarding emissions and their environmental impacts such as global warming and pollution. The price fluctuation of crude oil is an additional reason for the leading oil producing countries to consider renewable resources as an alternative. Saudi Arabia as the top oil exporter country in the word announced the "Saudi Arabia Vision 2030" which is targeting to generate 9.5 GW of electricity from renewable resources. Two of the most promising renewable technologies are wind turbines (WT) and photovoltaic cells (PV). The integration or hybridization of photovoltaics and wind turbines with battery storage leads to higher adequacy and redundancy for both autonomous and grid connected systems. This study presents a method for optimal generation unit planning by installing a proper number of solar cells, wind turbines, and batteries in such a way that the net present value (NPV) is minimized while the overall system redundancy and adequacy is maximized. A new renewable fraction technique (RFT) is used to perform the generation unit planning. RFT was tested and validated with particle swarm optimization and HOMER Pro under the same conditions and environment. Renewable resources and load randomness and uncertainties are considered. Both autonomous and grid-connected system designs were adopted in the optimal generation units planning process. An uncertainty factor was designed and incorporated in both autonomous and grid connected system designs. In the autonomous hybrid system design model, the strategy including an additional amount of operation reserve as a percent of the hourly load was considered to deal with resource uncertainty since the battery storage system is the only backup. While in the grid-connected hybrid system design model, demand response was incorporated to overcome the impact of

  20. Design, Fabrication, and Certification of Advanced Modular PV Power Systems Final Technical Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    Lambarski, T.; Minyard, G. (Solar Electric Specialties Co., Willits, California)

    1998-10-06

    This report describes the overall accomplishments and benefits of Solar Electric Specialties Co. (SES) under this Photovoltaic Manufacturing Technology (PVMaT) subcontract. SES addressed design issues related to their modular autonomous PV power supply (MAPPS) and a mobile photogenset. MAPPS investigations included gel-cell batteries mounted horizontally; redesign of the SES power supply; modified battery enclosure for increased safety and reduced cost; programmable, interactive battery charge controllers; and UL and FM listings. The photogenset systems incorporate generators, battery storage, and PV panels for a mobile power supply. The unit includes automatic oil-change systems for the propane generators, collapsible array mounts for the PV enclosure, and internal stowage of the arrays. Standardizing the products resulted in product lines of MAPPS and Photogensets that can be produced more economically and with shorter lead times, while increasing product quality and reliability. Product assembly and quality control have also been improved and streamlined with the development of standardized assembly processes and QC testing procedures. SES offers the UL-listed MAPPS at about the same price as its previous non-standardized, unlisted products.

  1. Multiresonant Frequency-Locked Loop for Grid Synchronization of Power Converters Under Distorted Grid Conditions

    DEFF Research Database (Denmark)

    Rodriguez, Pedro; Luna, Alvaro; Candela, Ignacio

    2011-01-01

    This paper presents a new multiresonant frequency-adaptive synchronization method for grid-connected power converters that allows estimating not only the positive- and negative-sequence components of the power signal at the fundamental frequency but also other sequence components at other harmonic......- and three-phase applications, deducing some key expressions regarding its stability and tuning. Moreover, the performance of the MSOGI-FLL is evaluated by both simulations and experiments to show its capability for detecting different harmonic components in a highly polluted grid scenario....

  2. Solar activity and economic fundamentals: Evidence from 12 geographically disparate power grids

    Science.gov (United States)

    Forbes, Kevin F.; St. Cyr, O. C.

    2008-10-01

    This study uses local (ground-based) magnetometer data as a proxy for geomagnetically induced currents (GICs) to address whether there is a space weather/electricity market relationship in 12 geographically disparate power grids: Eirgrid, the power grid that serves the Republic of Ireland; Scottish and Southern Electricity, the power grid that served northern Scotland until April 2005; Scottish Power, the power grid that served southern Scotland until April 2005; the power grid that serves the Czech Republic; E.ON Netz, the transmission system operator in central Germany; the power grid in England and Wales; the power grid in New Zealand; the power grid that serves the vast proportion of the population in Australia; ISO New England, the power grid that serves New England; PJM, a power grid that over the sample period served all or parts of Delaware, Maryland, New Jersey, Ohio, Pennsylvania, Virginia, West Virginia, and the District of Columbia; NYISO, the power grid that serves New York State; and the power grid in the Netherlands. This study tests the hypothesis that GIC levels (proxied by the time variation of local magnetic field measurements (dH/dt)) and electricity grid conditions are related using Pearson's chi-squared statistic. The metrics of power grid conditions include measures of electricity market imbalances, energy losses, congestion costs, and actions by system operators to restore grid stability. The results of the analysis indicate that real-time market conditions in these power grids are statistically related with the GIC proxy.

  3. Harnessing the hybrid power supply systems of utility grid and photovoltaic panels at retrofit residential single family building in Medan

    Science.gov (United States)

    Pangaribuan, A. B.; Rahmat, R. F.; Lidya, M. S.; Zálešák, M.

    2017-01-01

    The paper describes improvisation mode of energy supply source by collaboration between national utility grid as represented by fossil fuels and PV as independent renewable power resource in order to aim the energy consumptions efficiently in retrofit single family house. In this case, one existing single family house model in Medan, Indonesia was observed for the possibility of future refurbishment. The eco-design version of the house model and prediction analyses regarding nearby potential renewable energy resource (solar system) had been made using Autodesk Revit MEP 2015, Climate Consultant 6.0 and Green Building Studio Analysis. Economical evaluation of using hybrid power supply is discussed as well.

  4. Comparative analysis of existing models for power-grid synchronization

    Science.gov (United States)

    Nishikawa, Takashi; Motter, Adilson E.

    2015-01-01

    The dynamics of power-grid networks is becoming an increasingly active area of research within the physics and network science communities. The results from such studies are typically insightful and illustrative, but are often based on simplifying assumptions that can be either difficult to assess or not fully justified for realistic applications. Here we perform a comprehensive comparative analysis of three leading models recently used to study synchronization dynamics in power-grid networks—a fundamental problem of practical significance given that frequency synchronization of all power generators in the same interconnection is a necessary condition for a power grid to operate. We show that each of these models can be derived from first principles within a common framework based on the classical model of a generator, thereby clarifying all assumptions involved. This framework allows us to view power grids as complex networks of coupled second-order phase oscillators with both forcing and damping terms. Using simple illustrative examples, test systems, and real power-grid datasets, we study the inherent frequencies of the oscillators as well as their coupling structure, comparing across the different models. We demonstrate, in particular, that if the network structure is not homogeneous, generators with identical parameters need to be modeled as non-identical oscillators in general. We also discuss an approach to estimate the required (dynamical) system parameters that are unavailable in typical power-grid datasets, their use for computing the constants of each of the three models, and an open-source MATLAB toolbox that we provide for these computations.

  5. Smart Power Grid: A Holonic Approach

    NARCIS (Netherlands)

    Negeri, E.O.

    2014-01-01

    The electrical power system provides vital support for the functioning of modern so- cieties. Driven by the growing interest in clean, reliable and affordable energy, the electrical power system is facing transitions. The share of renewable energy sources in electricity supply is growing. In

  6. Smart Power Grid: A Holonic Approach

    NARCIS (Netherlands)

    Negeri, E.O.

    2014-01-01

    The electrical power system provides vital support for the functioning of modern so- cieties. Driven by the growing interest in clean, reliable and affordable energy, the electrical power system is facing transitions. The share of renewable energy sources in electricity supply is growing. In additio

  7. Smart Power Grid: A Holonic Approach

    NARCIS (Netherlands)

    Negeri, E.O.

    2014-01-01

    The electrical power system provides vital support for the functioning of modern so- cieties. Driven by the growing interest in clean, reliable and affordable energy, the electrical power system is facing transitions. The share of renewable energy sources in electricity supply is growing. In additio

  8. Simulation of Power Produced by a Building Added PV System in Indonesia using virtual reality

    NARCIS (Netherlands)

    Veldhuis, A.J.; Reinders, A.H.M.E.

    2014-01-01

    In this study a PV system will be simulated using virtual reality software for PV system simulations -called VR4PV - to show the effectiveness of the modelling of PV systems on buildings which are placed in the tropics. The PV system used for this study has been installed in Papua, Indonesia and inc

  9. Power grid dynamics. Electro-mechanical compensation processes in electric power grids; Netzdynamik. Elektromechanische Ausgleichsvorgaenge in elektrischen Energieversorgungsnetzen

    Energy Technology Data Exchange (ETDEWEB)

    Nelles, Dieter

    2009-07-01

    The dynamical behaviour of electric power grids is described. The focus is on explanation of physical phenomena, occuring during electro-mechanical compensation processes. Special emphasis is given on grid stability, the condition for a reliable line operation. Furtheron discussed are measures to enhance grid operation by power plant control and installation of power electronic control systems like FACTS (Flexible ALternating Current Transmission Systems) and UPFC (Unified Power Flow Controller). (orig./GL) [German] Das dynamische Verhalten von elektrischen Energieversorgungsnetzen wird beschrieben. Dabei liegt das Schwergewicht auf der Erlaeuterung der physikalischen Phaenomene, die bei den elektromechanischen Ausgleichvorgaengen auftreten. Naturgemaess steht die Netzstabilitaet, die Voraussetzung fuer jeden zuverlaessigen Netzbetrieb ist, im Vordergrund. Ebenfalls diskutiert werden die Massnahmen zur Verbesserung des Netzbetriebs durch die Kraftwerksregelung und den Einbau von leistungselektronischen Wirkleistungs- und Blindleistungsstellern wie FACTS und UPFC. (orig.)

  10. Reinforcing Power Grid Transmission with FACTS Devices

    CERN Document Server

    Frolov, Vladimir; Chertkov, Misha

    2013-01-01

    We explore optimization methods for planning the placement, sizing and operations of Flexible Alternating Current Transmission System (FACTS) devices installed into the grid to relieve congestion created by load growth or fluctuations of intermittent renewable generation. We limit our selection of FACTS devices to those that can be represented by modification of the inductance of the transmission lines. Our master optimization problem minimizes the $l_1$ norm of the FACTS-associated inductance correction subject to constraints enforcing that no line of the system exceeds its thermal limit. We develop off-line heuristics that reduce this non-convex optimization to a succession of Linear Programs (LP) where at each step the constraints are linearized analytically around the current operating point. The algorithm is accelerated further with a version of the cutting plane method greatly reducing the number of active constraints during the optimization, while checking feasibility of the non-active constraints post...

  11. PSCAD Modules Representing PV Generator

    Energy Technology Data Exchange (ETDEWEB)

    Muljadi, E.; Singh, M.; Gevorgian, V.

    2013-08-01

    Photovoltaic power plants (PVPs) have been growing in size, and the installation time is very short. With the cost of photovoltaic (PV) panels dropping in recent years, it can be predicted that in the next 10 years the contribution of PVPs to the total number of renewable energy power plants will grow significantly. In this project, the National Renewable Energy Laboratory (NREL) developed a dynamic modeling of the modules to be used as building blocks to develop simulation models of single PV arrays, expanded to include Maximum Power Point Tracker (MPPT), expanded to include PV inverter, or expanded to cover an entire PVP. The focus of the investigation and complexity of the simulation determines the components that must be included in the simulation. The development of the PV inverter was covered in detail, including the control diagrams. Both the current-regulated voltage source inverter and the current-regulated current source inverter were developed in PSCAD. Various operations of the PV inverters were simulated under normal and abnormal conditions. Symmetrical and unsymmetrical faults were simulated, presented, and discussed. Both the three-phase analysis and the symmetrical component analysis were included to clarify the understanding of unsymmetrical faults. The dynamic model validation was based on the testing data provided by SCE. Testing was conducted at SCE with the focus on the grid interface behavior of the PV inverter under different faults and disturbances. The dynamic model validation covers both the symmetrical and unsymmetrical faults.

  12. Synchronization in single-phase grid-connected photovoltaic systems under grid faults

    DEFF Research Database (Denmark)

    Yang, Yongheng; Blaabjerg, Frede

    2012-01-01

    The highly increasing penetration of single-phase photovoltaic (PV) systems pushes the grid requirements related to the integration of PV power systems to be updated. These upcoming regulations are expected to direct the grid-connected renewable generators to support the grid operation...... and stability both under grid faulty conditions and under normal operations. Grid synchronization techniques play an important role in the control of single-phase systems in order to fulfill these demands. Thus, it is necessary to evaluate the behaviors of grid synchronization methods in single phase systems...... under grid faults. The focus of this paper is put on the benchmarking of synchronization techniques, mainly about phase locked loop (PLL) based methods, in single-phase PV power systems operating under grid faults. Some faulty mode cases are studied at the end of this paper in order to compare...

  13. Power control for wind turbines in weak grids: Concepts development

    Energy Technology Data Exchange (ETDEWEB)

    Bindner, Henrik

    1999-03-01

    Presently, high wind potentials in remote areas may not be utilized for electricity production due to limited grid transmission capacity and/or difficulties in matching the electricity production with the demand. The overall project objective is to help overcome these bottlenecks, i.e. to identify and analyze methods and technologies for making it viable to utilize more of the wind potential in remote areas. The suggestion is to develop a power control concept for wind turbines which will even out the power fluctuations and make it possible to increase the wind energy penetration. The main options are to combine wind power with a pumped hydro power storage or with an AC/DC converter and battery storage. The AC/DC converter can either be an `add-on` type or it can be designed as an integrated part of a variable speed wind turbine. The idea is that combining wind power with the power control concept will make wind power more firm and possible to connect to weaker grids. So, when the concept is matured, the expectation is that for certain wind power installations, the cost of the power control is paid back as added wind power capacity value and saved grid reinforcement costs. Different systems for controlling the power output from a wind farm connected to a weak grid have been investigated. The investigation includes development of different control strategies, use of different storage types, development of a framework for comparing different options and tools needed as part of the framework. The main issues in the assessment of the power control concept are the storage capacity and power rating compared to the installed wind power capacity. The model SimStore has been developed to assess that. The economic investigations have shown that for small systems where only small amounts of wind energy would otherwise have been dumped add-on PQ-controllers with battery storage can be the least cost option compared to grid reinforcement and dumping of energy. For larger

  14. 考虑需求侧响应的光储并网型微电网优化配置%Optimal Sizing for Grid-connected PV-and-storage Microgrid Considering Demand Response

    Institute of Scientific and Technical Information of China (English)

    赵波; 包侃侃; 徐志成; 张有兵

    2015-01-01

    The high penetration distributed grid-tied photovoltaic (PV) generation demonstration areas have been formed in China due to the rapid development of PV power generation. Considering the limited PV accommodation of distributed networks, the high PV penetration integration will have negative effect on stable and economic operation of distribution system. In this paper, the object of study is grid-connected PV-and-storage microgrid system which is formed by installing storage energy in distributed PV generation system. Firstly, the storage system optimization is conducted. In addition, a demand response (DR) model is established to analyze its impact on the microgrid economic benefits and storage system optimization. A combinatorial optimization method combining with particle swarm optimization (PSO) is introduced to solve the DR model. The case study indicates the proposed grid-connected PV-and-storage microgrid system has a high economic benefits, low PV power generation curtailment, and beneficial impact on power system. It also demonstrates DR can effectively improve the load characteristics and further reduce storage capacity so that great economic benefits can be achieved.%针对我国分布式光伏的快速发展,一些地区已经形成高渗透率分布式光伏并网的示范区域。由于配电网消纳能力有限,较高的光伏渗透率已不利于配电网的安全稳定和经济运行,增加储能系统成为有效改善措施之一。该文研究对象为增加储能装置与已有分布式光伏组成并网型光储微电网,引入需求侧响应模型,对微电网储能进行优化配置,并以组合规划结合粒子群算法求解需求侧响应过程,分析需求侧响应对微电网经济效益和储能配置的影响。算例表明并网型光储微电网具有较高的经济效益,有效改善高渗透率分布式光伏并网对系统的影响和弃光限电现象;需求侧响应能够减少储能容量的配置,进一

  15. Curing critical links in oscillator networks as power grid models

    CERN Document Server

    Rohden, Martin; Timme, Marc; Meyer-Ortmanns, Hildegard

    2015-01-01

    Modern societies crucially depend on the robust supply with electric energy. Blackouts of power grids can thus have far reaching consequences. During a blackout, often the failure of a single infrastructure, such as a critical transmission line, results in several subsequent failures that spread across large parts of the network. Preventing such large-scale outages is thus key for assuring a reliable power supply. Here we present a non-local curing strategy for oscillatory power grid networks based on the global collective redistribution of loads. We first identify critical links and compute residual capacities on alternative paths on the remaining network from the original flows. For each critical link, we upgrade lines that constitute bottlenecks on such paths. We demonstrate the viability of this strategy for random ensembles of network topologies as well as topologies derived from real transmission grids and compare the nonlocal strategy against local back-ups of critical links. These strategies are indep...

  16. Methods and apparatus of analyzing electrical power grid data

    Energy Technology Data Exchange (ETDEWEB)

    Hafen, Ryan P.; Critchlow, Terence J.; Gibson, Tara D.

    2017-09-05

    Apparatus and methods of processing large-scale data regarding an electrical power grid are described. According to one aspect, a method of processing large-scale data regarding an electrical power grid includes accessing a large-scale data set comprising information regarding an electrical power grid; processing data of the large-scale data set to identify a filter which is configured to remove erroneous data from the large-scale data set; using the filter, removing erroneous data from the large-scale data set; and after the removing, processing data of the large-scale data set to identify an event detector which is configured to identify events of interest in the large-scale data set.

  17. Protecting Intelligent Distributed Power Grids against Cyber Attacks

    Energy Technology Data Exchange (ETDEWEB)

    Dong Wei; Yan Lu; Mohsen Jafari; Paul Skare; Kenneth Rohde

    2010-12-31

    Like other industrial sectors, the electrical power industry is facing challenges involved with the increasing demand for interconnected operations and control. The electrical industry has largely been restructured due to deregulation of the electrical market and the trend of the Smart Grid. This moves new automation systems from being proprietary and closed to the current state of Information Technology (IT) being highly interconnected and open. However, while gaining all of the scale and performance benefits of IT, existing IT security challenges are acquired as well. The power grid automation network has inherent security risks due to the fact that the systems and applications for the power grid were not originally designed for the general IT environment. In this paper, we propose a conceptual layered framework for protecting power grid automation systems against cyber attacks. The following factors are taken into account: (1) integration with existing, legacy systems in a non-intrusive fashion; (2) desirable performance in terms of modularity, scalability, extendibility, and manageability; (3) alignment to the 'Roadmap to Secure Control Systems in the Energy Sector' and the future smart grid. The on-site system test of the developed prototype security system is briefly presented as well.

  18. TOPOLOGY AND CASCADING LINE OUTAGES IN POWER GRIDS

    Institute of Scientific and Technical Information of China (English)

    David L. PEPYNE

    2007-01-01

    Motivated by the small world network research of Watts & Strogatz, this paper studies relationships between topology and cascading line outages in electric power grids. Cascading line outages are a type of cascading collapse that can occur in power grids when the transmission network is congested. It is characterized by a self-sustaining sequence of line outages followed by grid breakup, which generally leads to widespread blackout. The main findings of this work are twofold: On one hand, the work suggests that topologies with more disorder in their interconnection topology tend to be robust with respect to cascading line outages in the sense of being able to support greater generation and demand levels than more regularly interconnected topologies. On the other hand, the work suggests that topologies with more disorder tend to be more fragile in that should a cascade get started, they tend to break apart after fewer outages than more regularly interconnected topologies. Thus, as has been observed in other complex networks, there appears to be a tradeoff between robustness and fragility.These results were established using synthetically generated power grid topologies and verified using the IEEE 57 bus and 188 bus power grid test cases.

  19. Optimal Capacity Allocation of Large-Scale Wind-PV-Battery Units

    OpenAIRE

    Kehe Wu; Huan Zhou; Jizhen Liu

    2014-01-01

    An optimal capacity allocation of large-scale wind-photovoltaic- (PV-) battery units was proposed. First, an output power model was established according to meteorological conditions. Then, a wind-PV-battery unit was connected to the power grid as a power-generation unit with a rated capacity under a fixed coordinated operation strategy. Second, the utilization rate of renewable energy sources and maximum wind-PV complementation was considered and the objective function of full life cycle-net...

  20. A New Control Structure for Grid-Connected LCL PV Inverters with Zero Steady-State Error and Selective Harmonic Compensation

    DEFF Research Database (Denmark)

    Teodorescu, Remus; Blaabjerg, Frede; Borup, Uffe;

    2004-01-01

    disturbance rejection capability leads to the need of grid feed-forward compensation. However the imperfect compensation action of the feed-forward control results in high harmonic distortion of the current and consequently non-compliance with international standards. In this paper a new control strategy...... aimed to mitigate these problems is proposed. Stationary-frame generalized integrators are used to control the fundamental current and to compensate the grid harmonics providing disturbance rejection capability without the need of feed-forward grid compensation. Moreover the use of a grid LCL......-filter is investigated with the proposed controller. The current control strategy has been experimentally tested with success on a 3 kW PV inverter....