Modeling and Simulation of Buck-Boost Converter with Voltage Feedback Control
Directory of Open Access Journals (Sweden)
Zhou Xuelian
2015-01-01
Full Text Available In order to design the control system, it is necessary to have an exact model of buck-boost converter. This paper put forward the transfer function model of buck-boost converter by the state-space average method. The open-loop transfer function model of uncompensated system is deduced according to the mathematic model of the buck-boost converter, the controller is designed according to frequency domain. The phase and magnitude margin of the open-loop system of the buck-boost converter with compensator have both been increased. After compensating, this control system has the advantages of small overshoot and short settling time. It can also improve control system’s real time property and anti-interference ability.
Mathematical Modeling and Digital Control of A Hybrid Switching Buck Converter
Directory of Open Access Journals (Sweden)
Muhammad Umar Abbasi
2017-06-01
Full Text Available The aim of this paper is to describe mathematical modeling and digital control of a hybrid switching buck converter. This converter belongs to a class of so called hybrid switching converters and contains a resonant capacitor, resonant inductor and a diode in addition to original buck converter components. The dc gain of this converter is shown to be independent of resonant branch parameters. Moreover the dc conversion ratio is derived for both ideal case and including main inductor dc resistance. Small signal model of the converter is derived and is shown to be similar to conventional buck converter. Simulation results in SIMPLIS Software as well as experimental results of digital control using an 8 bit STM microcontroller are presented. The potential advantages and applications of this converter are discussed.
Accurate Sliding-Mode Control System Modeling for Buck Converters
DEFF Research Database (Denmark)
Høyerby, Mikkel Christian Wendelboe; Andersen, Michael Andreas E.
2007-01-01
This paper shows that classical sliding mode theory fails to correctly predict the output impedance of the highly useful sliding mode PID compensated buck converter. The reason for this is identified as the assumption of the sliding variable being held at zero during sliding mode, effectively...... approach also predicts the self-oscillating switching action of the sliding-mode control system correctly. Analytical findings are verified by simulation as well as experimentally in a 10-30V/3A buck converter....
Analysis, control and design of a non-inverting buck-boost converter
DEFF Research Database (Denmark)
Almasi, Omid Naghash; Fereshtehpoor, Vahid; Khooban, Mohammad Hassan
2017-01-01
In this paper, a new modified fuzzy Two-Level Control Scheme (TLCS) is proposed to control a non-inverting buck-boost converter. Each level of fuzzy TLCS consists of a tuned fuzzy PI controller. In addition, a Takagi–Sugeno–Kang (TSK) fuzzy switch proposed to transfer the fuzzy PI controllers...... to eliminate these oscillations and improve the system performance. Some simulations and digital signal processor based experiments are conducted on a non-inverting buck-boost converter to support the effectiveness of the proposed TLCS in controlling the converter output voltage....... to each other in the control system. The major difficulty in designing fuzzy TLCS which degrades its performance is emerging unwanted drastic oscillations in the converter output voltage during replacing the controllers. Thereby, the fuzzy PI controllers in each level of TLCS structure are modified...
Schoenfeld, A. D.; Yu, Y.
1973-01-01
Versatile standardized pulse modulation nondissipatively regulated control signal processing circuits were applied to three most commonly used dc to dc power converter configurations: (1) the series switching buck-regulator, (2) the pulse modulated parallel inverter, and (3) the buck-boost converter. The unique control concept and the commonality of control functions for all switching regulators have resulted in improved static and dynamic performance and control circuit standardization. New power-circuit technology was also applied to enhance reliability and to achieve optimum weight and efficiency.
A Reconfigurable Buck, Boost, and Buck-Boost Converter: Unified Model and Robust Controller
Directory of Open Access Journals (Sweden)
Martín Antonio Rodríguez Licea
2018-01-01
Full Text Available The need for reconfigurable, high power density, and low-cost configurations of DC-DC power electronic converters (PEC in areas such as the transport electrification and the use of renewable energy has spread out the requirement to incorporate in a single circuit several topologies, which generally result in an increment of complexity about the modeling, control, and stability analyses. In this paper, a reconfigurable topology is presented which can be applied in alterative/changing power conversion scenarios and consists of a reconfigurable Buck, Boost, and Buck-Boost DC-DC converter (RBBC. A unified averaged model of the RBBC is obtained, a robust controller is designed through a polytopic representation, and a Lyapunov based switched stability analysis of the closed-loop system is presented. The reported RBBC provides a wide range of voltage operation, theoretically from -∞ to ∞ volts with a single power source. Robust stability, even under arbitrarily fast (bounded parameter variations and reconfiguration changes, is reported including numerical and experimental results. The main advantages of the converter and the robust controller proposed are simple design, robustness against abrupt changes in the parameters, and low cost.
Sliding-Mode Control Design of a Boost-Buck Switching Converter for AC Signal Generation
Biel Solé, Domingo; Guinjoan Gispert, Francisco; Fossas Colet, Enric; Chavarría Roé, Javier
2004-01-01
This paper presents a sliding-mode control design of a boost–buck switching converter for a voltage step-up dc–ac conversion without the use of any transformer. This approach combines the step-up/step-down conversion ratio capability of the converter with the robustness properties of sliding-mode control. The proposed control strategy is based on the design of two slidingcontrol laws, one ensuring the control of a full-bridge buck converter for proper dc–ac conversion, and the other one the c...
Application of Theory of Hybrid Systems to Control the Switching of Buck Converter
Benmiloud, Mohammed; Benalia, Atallah; Laleg-Kirati, Taous-Meriem
2013-01-01
The field of power electronics poses challenging control problems that can’t be treated in a complete manner using traditional modeling. In this paper, the buck converter operating in Continuous Conduction Mode (CCM) is represented analytically by hybrid automaton model and graphically representation is also given. The hybrid trajectory and the model behavior are presented. The control problem of buck switching converters is transformed to a guard selection problem. The guard selection calculation formulas of buck converter are derived from the basic circuit laws. The stability of the switching is established analytically by the use of multiple Lyapunov functions to ensure the convergence and Poincare map to assess the local stability of the limit cycle. Numerical results clearly bring out the advantages and effectiveness of the proposed control law under varying line voltage and load conditions. Simulation studies are carried out in Matlab/Simulink/Stateflow.
Application of Theory of Hybrid Systems to Control the Switching of Buck Converter
Benmiloud, Mohammed
2013-08-01
The field of power electronics poses challenging control problems that can’t be treated in a complete manner using traditional modeling. In this paper, the buck converter operating in Continuous Conduction Mode (CCM) is represented analytically by hybrid automaton model and graphically representation is also given. The hybrid trajectory and the model behavior are presented. The control problem of buck switching converters is transformed to a guard selection problem. The guard selection calculation formulas of buck converter are derived from the basic circuit laws. The stability of the switching is established analytically by the use of multiple Lyapunov functions to ensure the convergence and Poincare map to assess the local stability of the limit cycle. Numerical results clearly bring out the advantages and effectiveness of the proposed control law under varying line voltage and load conditions. Simulation studies are carried out in Matlab/Simulink/Stateflow.
Faisal, A.; Hasan, S.; Suherman
2018-03-01
AC-DC converter is widely used in the commercial industry even for daily purposes. The AC-DC converter is used to convert AC voltage into DC. In order to obtain the desired output voltage, the converter usually has a controllable regulator. This paper discusses buck boost regulator with a power MOSFET as switching component which is adjusted based on the duty cycle of pulse width modulation (PWM). The main problems of the buck boost converter at start up are the high overshoot, the long peak time and rise time. This paper compares the effectiveness of two control techniques: proportional integral derivative (PID) and fuzzy logic control in controlling the buck boost converter through simulations. The results show that the PID is more sensitive to voltage change than fuzzy logic. However, PID generates higher overshoot, long peak time and rise time. On the other hand, fuzzy logic generates no overshoot and shorter rise time.
Quasi-Resonant Full-Wave Zero-Current Switching Buck Converter Design, Simulation and Application
Yanik, G.; Isen, E.
2015-01-01
—This paper presents a full wave quasi-resonant zerocurrent switching buck converter design, simulation and application. The converter control uses with zero-current switching (ZCS) technique to decrease the switching losses. Comparing to conventional buck converter, resonant buck converter includes a resonant tank equipped with resonant inductor and capacitor. The converter is analyzed in mathematical for each subintervals. Depending on the desired input and output electrical quantities, con...
Hoyos Velasco, Fredy Edimer; García, Nicolás Toro; Garcés Gómez, Yeison Alberto
In this paper, the output voltage of a buck power converter is controlled by means of a quasi-sliding scheme. The Fixed Point Inducting Control (FPIC) technique is used for the control design, based on the Zero Average Dynamics (ZAD) strategy, including load estimation by means of the Least Mean Squares (LMS) method. The control scheme is tested in a Rapid Control Prototyping (RCP) system based on Digital Signal Processing (DSP) for dSPACE platform. The closed loop system shows adequate performance. The experimental and simulation results match. The main contribution of this paper is to introduce the load estimator by means of LMS, to make ZAD and FPIC control feasible in load variation conditions. In addition, comparison results for controlled buck converter with SMC, PID and ZAD-FPIC control techniques are shown.
Directory of Open Access Journals (Sweden)
R. Silva-Ortigoza
2014-01-01
Full Text Available This paper presents a hierarchical controller that carries out the angular velocity trajectory tracking task for a DC motor driven by a DC/DC Buck converter. The high level control is related to the DC motor and the low level control is dedicated to the DC/DC Buck converter; both controls are designed via differential flatness. The high level control provides a desired voltage profile for the DC motor to achieve the tracking of a desired angular velocity trajectory. Then, a low level control is designed to ensure that the output voltage of the DC/DC Buck converter tracks the voltage profile imposed by the high level control. In order to experimentally verify the hierarchical controller performance, a DS1104 electronic board from dSPACE and Matlab-Simulink are used. The switched implementation of the hierarchical average controller is accomplished by means of pulse width modulation. Experimental results of the hierarchical controller for the velocity trajectory tracking task show good performance and robustness against the uncertainties associated with different system parameters.
Decentralized Interleaving of Paralleled Dc-Dc Buck Converters: Preprint
Energy Technology Data Exchange (ETDEWEB)
Johnson, Brian B [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Rodriguez, Miguel [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Sinha, Mohit [University of Minnesota; Dhople, Sairaj [University of Minnesota; Poon, Jason [University of California at Berkeley
2017-09-01
We present a decentralized control strategy that yields switch interleaving among parallel connected dc-dc buck converters without communication. The proposed method is based on the digital implementation of the dynamics of a nonlinear oscillator circuit as the controller. Each controller is fully decentralized, i.e., it only requires the locally measured output current to synthesize the pulse width modulation (PWM) carrier waveform. By virtue of the intrinsic electrical coupling between converters, the nonlinear oscillator-based controllers converge to an interleaved state with uniform phase-spacing across PWM carriers. To the knowledge of the authors, this work represents the first fully decentralized strategy for switch interleaving of paralleled dc-dc buck converters.
Xiaobo, Wu; Qing, Liu; Menglian, Zhao; Mingyang, Chen
2013-01-01
An analog implementation of a novel fixed-frequency quasi-sliding-mode controller for single-inductor dual-output (SIDO) buck converter in pseudo-continuous conduction mode (PCCM) with a self-adaptive freewheeling current level (SFCL) is presented. Both small and large signal variations around the operation point are considered to achieve better transient response so as to reduce the cross-regulation of this SIDO buck converter. Moreover, an internal integral loop is added to suppress the steady-state regulation error introduced by conventional PWM-based sliding mode controllers. Instead of keeping it as a constant value, the free-wheeling current level varies according to the load condition to maintain high power efficiency and less cross-regulation at the same time. To verify the feasibility of the proposed controller, an SIDO buck converter with two regulated output voltages, 1.8 V and 3.3 V, is designed and fabricated in HEJIAN 0.35 μm CMOS process. Simulation and experiment results show that the transient time of this SIDO buck converter drops to 10 μs while the cross-regulation is reduced to 0.057 mV/mA, when its first load changes from 50 to 100 mA.
The Model and Quadratic Stability Problem of Buck Converter in DCM
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Li Xiaojing
2016-01-01
Full Text Available Quadratic stability is an important performance for control systems. At first, the model of Buck Converter in DCM is built based on the theories of hybrid systems and switched linear systems primarily. Then quadratic stability of SLS and hybrid feedback switching rule are introduced. The problem of Buck Converter’s quadratic stability is researched afterwards. In the end, the simulation analysis and verification are provided. Both experimental verification and theoretical analysis results indicate that the output of Buck Converter in DCM has an excellent performance via quadratic stability control and switching rules.
Evaluation of Arm Processor-based Bionic Intelligent Controller for a Buck-boost Converte
M.V. Mini; L. Padma Suresh
2015-01-01
This study focuses on performance-comparison of different tuning methods for a PI controller applied to a buck-boost converter. Comparison between the controllers is made by analysis of design methodology implementation issues and empirically measured performance. Design of PI controller is based on frequency response of the converter. The optimization of PI controller is based on ant colony algorithm. Experimental results show that, tuning the PI controller using ACO algorithm gave better pe...
Two phase interleaved buck converter for driving high power LEDs
DEFF Research Database (Denmark)
Beczkowski, Szymon; Munk-Nielsen, Stig
2011-01-01
The goal of this paper is to evaluate an interleaved buck topology for driving high current light-emitting diodes. Low output capacitor value allows the use of non-electrolytic capacitors extending the lifetime of the converter. Converter is operated as a constant, regulated current source which...... increases luminous efficacy of LED compared to PWM dimmed system. Because of the low dynamic resistance of LEDs the duty cycle of the converter does not change greatly with controlled current. By setting the input voltage of the buck converter to around twice the voltage of diode strings, converter can...
International Nuclear Information System (INIS)
Wu Xiaobo; Liu Qing; Zhao Menglian; Chen Mingyang
2013-01-01
An analog implementation of a novel fixed-frequency quasi-sliding-mode controller for single-inductor dual-output (SIDO) buck converter in pseudo-continuous conduction mode (PCCM) with a self-adaptive freewheeling current level (SFCL) is presented. Both small and large signal variations around the operation point are considered to achieve better transient response so as to reduce the cross-regulation of this SIDO buck converter. Moreover, an internal integral loop is added to suppress the steady-state regulation error introduced by conventional PWM-based sliding mode controllers. Instead of keeping it as a constant value, the free-wheeling current level varies according to the load condition to maintain high power efficiency and less cross-regulation at the same time. To verify the feasibility of the proposed controller, an SIDO buck converter with two regulated output voltages, 1.8 V and 3.3 V, is designed and fabricated in HEJIAN 0.35 μm CMOS process. Simulation and experiment results show that the transient time of this SIDO buck converter drops to 10 μs while the cross-regulation is reduced to 0.057 mV/mA, when its first load changes from 50 to 100 mA. (semiconductor integrated circuits)
Dynamics and stabilization of peak current-mode controlled buck converter with constant current load
International Nuclear Information System (INIS)
Leng Min-Rui; Zhou Guo-Hua; Zhang Kai-Tun; Li Zhen-Hua
2015-01-01
The discrete iterative map model of peak current-mode controlled buck converter with constant current load (CCL), containing the output voltage feedback and ramp compensation, is established in this paper. Based on this model the complex dynamics of this converter is investigated by analyzing bifurcation diagrams and the Lyapunov exponent spectrum. The effects of ramp compensation and output voltage feedback on the stability of the converter are investigated. Experimental results verify the simulation and theoretical analysis. The stability boundary and chaos boundary are obtained under the theoretical conditions of period-doubling bifurcation and border collision. It is found that there are four operation regions in the peak current-mode controlled buck converter with CCL due to period-doubling bifurcation and border-collision bifurcation. Research results indicate that ramp compensation can extend the stable operation range and transfer the operating mode, and output voltage feedback can eventually eliminate the coexisting fast-slow scale instability. (paper)
Bifurcation and Chaos in a Pulse Width modulation controlled Buck Converter
DEFF Research Database (Denmark)
Kocewiak, Lukasz; Bak, Claus Leth; Munk-Nielsen, Stig
2007-01-01
by a system of piecewise-smooth nonautonomous differential equations. The research are focused on chaotic oscillations analysis and analytical search for bifurcations dependent on parameter. The most frequent route to chaos by the period doubling is observed in the second order DC-DC buck converter. Other...... bifurcations as a complex behaviour in power electronic system evidence are also described. In order to verify theoretical study the experimental DC-DC buck converter was build. The results obtained from three sources were presented and compared. A very good agreement between theory and experiment was observed....
A zero-voltage-switched three-phase interleaved buck converter
Hsieh, Yao-Ching; Huang, Bing-Siang; Lin, Jing-Yuan; Pham, Phu Hieu; Chen, Po-Hao; Chiu, Huang-Jen
2018-04-01
This paper proposes a three-phase interleaved buck converter which is composed of three identical paralleled buck converters. The proposed solution has three shunt inductors connected between each other of three basic buck conversion units. With the help of the shunt inductors, the MOSFET parasitic capacitances will resonate to achieve zero-voltage-switching. Furthermore, the decreasing rate of the current through the free-wheeling diodes is limited, and therefore, their reverse-recovery losses can be minimised. The active power switches are controlled by interleaved pulse-width modulation signals to reduce the input and output current ripples. Therefore, the filtering capacitances on the input and output sides can be reduced. The power efficiency is measured to be as high as 98% in experiment with a prototype circuit.
Directory of Open Access Journals (Sweden)
Jaw-Kuen Shiau
2014-08-01
Full Text Available The power converter is one of the essential elements for effective use of renewable power sources. This paper focuses on the development of a circuit simulation model for maximum power point tracking (MPPT evaluation of solar power that involves using different buck-boost power converter topologies; including SEPIC, Zeta, and four-switch type buck-boost DC/DC converters. The circuit simulation model mainly includes three subsystems: a PV model; a buck-boost converter-based MPPT system; and a fuzzy logic MPPT controller. Dynamic analyses of the current-fed buck-boost converter systems are conducted and results are presented in the paper. The maximum power point tracking function is achieved through appropriate control of the power switches of the power converter. A fuzzy logic controller is developed to perform the MPPT function for obtaining maximum power from the PV panel. The MATLAB-based Simulink piecewise linear electric circuit simulation tool is used to verify the complete circuit simulation model.
Almasi, Omid Naghash; Fereshtehpoor, Vahid; Khooban, Mohammad Hassan; Blaabjerg, Frede
2017-03-01
In this paper, a new modified fuzzy Two-Level Control Scheme (TLCS) is proposed to control a non-inverting buck-boost converter. Each level of fuzzy TLCS consists of a tuned fuzzy PI controller. In addition, a Takagi-Sugeno-Kang (TSK) fuzzy switch proposed to transfer the fuzzy PI controllers to each other in the control system. The major difficulty in designing fuzzy TLCS which degrades its performance is emerging unwanted drastic oscillations in the converter output voltage during replacing the controllers. Thereby, the fuzzy PI controllers in each level of TLCS structure are modified to eliminate these oscillations and improve the system performance. Some simulations and digital signal processor based experiments are conducted on a non-inverting buck-boost converter to support the effectiveness of the proposed TLCS in controlling the converter output voltage. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.
Buck Converter with Soft-Switching Cells for PV Panel Applications
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Cheng-Tao Tsai
2016-03-01
Full Text Available In power conversion of photovoltaic (PV energy, a hard-switching buck converter always generates some disadvantages. For example, serious electromagnetic interference (EMI, high switching losses, and stresses on an active switch (metal-oxide-semiconductor-field-effect-transistor, MOSFET, and high reverse-recovery losses of a freewheeling diode result in low conversion efficiency. To release these disadvantages, a buck converter with soft-switching cells for PV panel applications is proposed. To create zero-voltage-switching (ZVS features of the active switches, a simple active soft-switching cell with an inductor, a capacitor, and a MOSFET is incorporated into the proposed buck converter. Therefore, the switching losses and stresses of the active switches and EMI can be reduced significantly. To reduce reverse-recovery losses of a freewheeling diode, a simple passive soft-switching cell with a capacitor and two diodes is implemented. To verify the performance and the feasibility of the proposed buck converter with soft-switching cells for PV panel applications, a prototype soft-switching buck converter is built and implemented by using a maximum-power-point-tracking (MPPT method. Simulated and experimental results are presented from a 100 W soft-switching buck converter for PV panel applications.
Non-Inverting Buck-Boost Converter for Fuel Cell Applications
DEFF Research Database (Denmark)
Schaltz, Erik; Rasmussen, Peter Omand; Khaligh, Alireza
2008-01-01
Fuel cell DC/DC converters often have to be able to both step-up and step-down the input voltage, and provide a high efficiency in the whole range of output power. Conventional negative output buck-boost and non-inverting buck-boost converters provide both step-up and step-down characteristics....... In this paper the non-inverting buck-boost with either diodes or synchronous rectifiers is investigated for fuel cell applications. Most of previous research does not consider the parasitic in the evaluation of the converters. In this study, detailed analytical expressions of the efficiencies for the system...
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Ahmed Sabah Al-Araji
2017-08-01
Full Text Available This paper presents a new development of an on-line hybrid self-tuning control algorithm of the Field Programmable Gate Array - Proportional Integral Derivative - Pulse Width Modulation (FPGA-PID-PWM controller for DC-DC buck converter which is used in battery operation of mobile applications. The main goal in this work is to propose structure of the hybrid Bees-PSO tuning control algorithm which has a capability of quickly and precisely searching in the global regions in order to obtain optimal gain parameters for the proposed controller to generate the best voltage control action to achieve the desired performance of the Buck converter output. Matlab simulation results and Xilinx development tool Integrated Software Environment (ISE experimental work show the robustness and effectiveness of the proposed on-line hybrid Bees-PSO tuning control algorithm in terms of obtaining smooth and unsaturated state voltage control action and minimizing the tracking voltage error of the Buck converter output. Moreover, the fitness evaluation number is reduced.
Spinu, V.; Oliveri, A.; Lazar, M.; Storace, M.
2012-01-01
This paper proposes a method for FPGA implementation of explicit, piecewise af¿ne (PWA) model predictive control (MPC) laws for non-inverting buck-boost DC-DC converters. A novel approach to obtain a PWA model of the power converter is proposed and two explicit MPC laws are derived, i.e., one based
Dynamics and stabilization of peak current-mode controlled buck converter with constant current load
Leng, Min-Rui; Zhou, Guo-Hua; Zhang, Kai-Tun; Li, Zhen-Hua
2015-10-01
The discrete iterative map model of peak current-mode controlled buck converter with constant current load (CCL), containing the output voltage feedback and ramp compensation, is established in this paper. Based on this model the complex dynamics of this converter is investigated by analyzing bifurcation diagrams and the Lyapunov exponent spectrum. The effects of ramp compensation and output voltage feedback on the stability of the converter are investigated. Experimental results verify the simulation and theoretical analysis. The stability boundary and chaos boundary are obtained under the theoretical conditions of period-doubling bifurcation and border collision. It is found that there are four operation regions in the peak current-mode controlled buck converter with CCL due to period-doubling bifurcation and border-collision bifurcation. Research results indicate that ramp compensation can extend the stable operation range and transfer the operating mode, and output voltage feedback can eventually eliminate the coexisting fast-slow scale instability. Project supported by the National Natural Science Foundation of China (Grant No. 61371033), the Fok Ying-Tung Education Foundation for Young Teachers in the Higher Education Institutions of China (Grant No. 142027), the Sichuan Provincial Youth Science and Technology Fund, China (Grant Nos. 2014JQ0015 and 2013JQ0033), and the Fundamental Research Funds for the Central Universities, China (Grant No. SWJTU11CX029).
Buck-Boost DC-DC Converter Control by Using the Extracted Model from Signal Flow Graph Method
Mohammadian, Leila; Babaei, Ebrahim; Bannae Sharifian, Mohammad Bagher
2015-01-01
In this paper, the signal flow graph technique and Mason gain formula are applied for extracting the model and transfer functions from control to output and from input to output of a buck-boost converter. In order to investigate a controller necessity for the converter of assumed parameters, the frequency and time domain analysis are done and the open loop system characteristics are verified and the needed closed loop controlled system specifications are determined. Finally designing a contro...
DEFF Research Database (Denmark)
Mira Albert, Maria del Carmen; Zhang, Zhe; Knott, Arnold
2015-01-01
DC microgrids or nanogrids have attracted increasing research interest in recent years. Therefore, as a critical component, dc-dc converters with multiple inputs are required. In this paper, a dual-input interleaved buck/boost converter is proposed and its corresponding power flow control methods...
A Novel Single Switch Transformerless Quadratic DC/DC Buck-Boost Converter
DEFF Research Database (Denmark)
Mostaan, Ali; A. Gorji, Saman; N. Soltani, Mohsen
2017-01-01
A novel quadratic buck-boost DC/DC converter is presented in this study. The proposed converter utilizes only one active switch and can step-up/down the input voltage, while the existing single switch quadratic buck/boost converters can only work in step-up or step-down mode. First, the proposed ...
Directory of Open Access Journals (Sweden)
R. Silva-Ortigoza
2013-01-01
differential flatness property of the DC-motor model is exploited in order to propose a first-stage controller, which is designed to achieve the desired angular velocity trajectory. This controller provides the voltage profiles that must be tracked by the Buck converter. Then, a second-stage controller is meant to assure the aforementioned. This controller is based on flatness property of the Buck power converter model, which provides the input voltage to the DC motor. Due to the fact that the two-stage controller proposed uses the average model of the system, as a practical and effective implementation of this controller, a Σ − Δ-modulator is employed. Finally, in order to verify the control performance of this approach, numerical simulations are included.
Deadbeat control of power leveling unit with bidirectional buck/boost DC/DC converter
Hamasaki, Shin-ichi; Mukai, Ryosuke; Yano, Yoshihiro; Tsuji, Mineo
2014-01-01
As a distributed generation system increases, a stable power supply becomes difficult. Thus control of power leveling (PL) unit is required to maintain the balance of power flow for irregular power generation. The unit is required to respond to change of voltage and bidirectional power flow. So the bidirectional buck/boost DC/DC converter is applied for the control of PL unit in this research. The PL unit with Electric double-layer capacitor (EDLC) is able to absorb change of power, and it is...
Research procedure for buck-boost converter for small electric vehicles
Vacheva, Gergana; Hinov, Nikolay; Penev, Dimitar
2017-12-01
In the current paper is developed a mathematical model realized in Matlab for describing a buck-boost converter for control of small electric vehicle. The model is presented with differential equations which describes the processes in the converter. Through the research of this model it can be accomplished the optimal work mode of a small electric vehicles. The proposed converter can be used in a wide range of applications like small electric vehicles, smart grids and different systems for energy storage.
Sliding Mode Control of a Bidirectional Buck/Boost DC-DC Converter with Constant Switching Frequency
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A. Safari
2018-03-01
Full Text Available In this paper, sliding mode control (SMC for a bidirectional buck/boost DC-DC converter (BDC with constant frequency in continuous conduction mode (CCM is discussed. Since the converter is a high-order converter, the reduced-order sliding manifold is exploited. Because of right-half-plan zero (RHPZ in the converter’s duty ratio to output voltage transfer function, sliding mode current controller is used. This controller benefits from various advantages such as fast dynamic response, robustness, stable and small variation of the settling time over a wide range of operation conditions. Because the converter operates in both step-down and step-up modes, two sliding manifold is derived for each mode. The existence and stability conditions are analyzed for both SMC in step-down and step-up modes. Finally, Simulation results are also provided to justify the feasibility of the controller using MATLAB/Simulink.
Generalized Switched-Inductor Based Buck-Boost Z-H Converter
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E. Babaei
2017-12-01
Full Text Available In this paper, a generalized buck-boost Z-H converter based on switched inductors is proposed. This structure consists of a set of series connected switched-inductor cells. The voltage conversion ratio of the proposed structure is adjusted by changing the number of cells and the duty cycle. Like the conventional Z-H converter, the shoot-through switching state and the diode before LC network are eliminated. The proposed converter can provide high voltage gain in low duty cycles. Considering different values for duty cycle, the proposed structure works in two operating zones. In the first operating zone, it works as a buck-boost converter and in the second operating zone, it works as a boost converter. In this paper, a complete analysis of the proposed converter is presented. In order to confirm the accuracy of mathematic calculations, the simulations results by using PSCAD/EMTDC software are given.
Closed-loop analysis and control of a non-inverting buck-boost converter
Chen, Zengshi; Hu, Jiangang; Gao, Wenzhong
2010-11-01
In this article, a cascade controller is designed and analysed for a non-inverting buck-boost converter. The fast inner current loop uses sliding mode control. The slow outer voltage loop uses the proportional-integral (PI) control. Stability analysis and selection of PI gains are based on the nonlinear closed-loop error dynamics incorporating both the inner and outer loop controllers. The closed-loop system is proven to have a nonminimum phase structure. The voltage transient due to step changes of input voltage or resistance is predictable. The operating range of the reference voltage is discussed. The controller is validated by a simulation circuit. The simulation results show that the reference output voltage is well-tracked under system uncertainties or disturbances, confirming the validity of the proposed controller.
Application of Minimum-time Optimal Control System in Buck-Boost Bi-linear Converters
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S. M. M. Shariatmadar
2017-08-01
Full Text Available In this study, the theory of minimum-time optimal control system in buck-boost bi-linear converters is described, so that output voltage regulation is carried out within minimum time. For this purpose, the Pontryagin's Minimum Principle is applied to find optimal switching level applying minimum-time optimal control rules. The results revealed that by utilizing an optimal switching level instead of classical switching patterns, output voltage regulation will be carried out within minimum time. However, transient energy index of increased overvoltage significantly reduces in order to attain minimum time optimal control in reduced output load. The laboratory results were used in order to verify numerical simulations.
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Mahmoud Shaker Nasr
2017-03-01
Full Text Available This paper presents firstly a buck-boost circuit with the advantage that its output voltage polarity is the same as the input polarity. The circuit operation is presented and analyzed in different modes of operation. The well known parameters used in evaluation of DC/DC converters like Total Harmonic Distortion THD, Power Factor PF, and Ripple Factor RF have no meaning in DC/DC converters, so it is to introduce efficient concepts to permit a fair evaluation of the converter. This paper present other parameters that can be used to study the characteristics of the converter and gives a real and logic means of its operation. These main parameters are: pumping energy PE, storage energy SE, energy factor EF, and energy losses EL. In addition, the converter efficiency is not considered as 100 % as taken in most analyzing studies. The positive DC/DC buck-boost converter is evaluated according to the new concepts and the system model is deduced for different cases of operation taking into account the resistance of the circuit inductor. The circuit is implemented practically and the presented obtained results show the correct operation under different modes of operation. In addition the control design of the converter is built such that a PI controller with windup is considered. In order to test the effectiveness of the designed control algorithm, the system were exposed to different voltage reference values and the obtained results demonstrate that the system responses for all cases are very acceptable according to the criteria of the control system theory.
Cross-Regulation Assessment of DIDO Buck-Boost Converter for Renewable Energy Application
Directory of Open Access Journals (Sweden)
Deepak Elamalayil Soman
2017-06-01
Full Text Available When medium- or high-voltage power conversion is preferred for renewable energy sources, multilevel power converters have received much of the interest in this area as methods for enhancing the conversion efficiency and cost effectiveness. In such cases, multilevel, multi-input multi-output (MIMO configurations of DC-DC converters come to the scenario for integrating several sources together, especially considering the stringent regulatory needs and the requirement of multistage power conversion systems. Considering the above facts, a three-level dual input dual output (DIDO buck-boost converter, as the simplest form of MIMO converter, is proposed in this paper for DC-link voltage regulation. The capability of this converter for cross regulating the DC-link voltage is analyzed in detail to support a three-level neutral point clamped inverter-based grid connection in the future. The cross-regulation capability is examined under a new type of pulse delay control (PDC strategy and later compared with a three-level boost converter (TLBC. Compared to conventional boost converters, the high-voltage three-level buck boost converter (TLBBC with PDC exhibits a wide controllability range and cross regulation capability. These enhanced features are extremely important for better regulating variable output renewable energy sources such as solar, wind, wave, marine current, etc. The simulation and experimental results are provided to validate the claim.
A Bond Graph Approach for the Modeling and Simulation of a Buck Converter
Directory of Open Access Journals (Sweden)
Rached Zrafi
2018-01-01
Full Text Available This paper deals with the modeling of bond graph buck converter systems. The bond graph formalism, which represents a heterogeneous formalism for physical modeling, is used to design a sub-model of a power MOSFET and PiN diode switchers. These bond graph models are based on the device’s electrical elements. The application of these models to a bond graph buck converter permit us to obtain an invariant causal structure when the switch devices change state. This paper shows the usefulness of the bond graph device’s modeling to simulate an implicit bond graph buck converter.
Directory of Open Access Journals (Sweden)
M. Č. Bošković
2016-06-01
Full Text Available This paper presents a comparison of voltage mode control (VMC and two current mode control (CMC methods of noninverting buck-boost converter. The converter control-to-output transfer function, line-to-output transfer function and the output impedance are obtained for all methods by averaging converter equations over one switching period and applying small-signal linearization. The obtained results are required for the design procedure of feedback compensator to keep a system stable and robust. A comparative study of VMC, peak current mode control (PCMC and dual-current mode control (DCMC is performed. Performance evaluation of the closed-loop system with obtained compensator between these methods is performed via numerical simulations.
A Novel Soft-Switching Synchronous Buck Converter for Portable Applications
Directory of Open Access Journals (Sweden)
Anup Kumar Panda
2008-01-01
Full Text Available This paper proposes a zero-voltage-transition (ZVT pulse-width-modulated (PWM synchronous buck converter, which is designed to operate at low voltage and high efficiency typically required for portable systems. A new passive auxiliary circuit that allows the main switch to operate with zero-voltage switching has been incorporated in the conventional PWM synchronous buck converter. The operation principles and a detailed steady-state analysis of the ZVT-PWM synchronous converter implemented with the auxiliary circuit are presented. Besides, the main switch and all of the semiconductor devices operate under soft-switching conditions. Thus, the auxiliary circuit provides a larger overall efficiency. The feasibility of the auxiliary circuit is confirmed by simulation and experimental results.
Mahrubi, Irfan; Bintoro, Jusuf; Djatmiko, Wisnu
2018-01-01
Penelitian ini bertujuan untuk merancang bangun rangkaian synchronous non-inverting buck-boost converter (SNIBBC) untuk solar charge controller guna melakukan manajemen pengisian baterai dan manajemen beban dengan menggunakan Arduino Nano V3.0 ATMega 328. Rancang bangun rangkaian synchronous non-inverting buck-boost converter (SNIBBC) menggunakan empat mosfet yang bekerja secara saling singkron dengan dikontrol oleh pulsa PWM dari Timer1 arduino nano V3.0 ATMega 328 dengan frekuensi 10KHz men...
Sensorless load torque estimation and passivity based control of buck converter fed DC motor.
Kumar, S Ganesh; Thilagar, S Hosimin
2015-01-01
Passivity based control of DC motor in sensorless configuration is proposed in this paper. Exact tracking error dynamics passive output feedback control is used for stabilizing the speed of Buck converter fed DC motor under various load torques such as constant type, fan type, propeller type, and unknown load torques. Under load conditions, sensorless online algebraic approach is proposed, and it is compared with sensorless reduced order observer approach. The former produces better response in estimating the load torque. Sensitivity analysis is also performed to select the appropriate control variables. Simulation and experimental results fully confirm the superiority of the proposed approach suggested in this paper.
DEFF Research Database (Denmark)
Jakobsen, Lars Tønnes; Garcia, O.; Oliver, J. A.
2008-01-01
The efficiency of an interleaved Buck converter is typically low at light load conditions because of the switching losses in each of the switching stages. Improvements in the converter efficiency can be achieved by dynamically changing the number of active phases depending on the load current....... This paper addresses the issues related to the transient response of the converter when the number of active phases is changed by a digital control scheme. The problem arises because the current in the individual phases of the interleaved Buck converter will not be equal immediately after the controller has...... changed the number of active phases. This paper proposes a current equalisation scheme that adjusts the duty cycle of each phase in a manner that ensures equal average inductor current in all active phases in one or two PWM periods. The current equalisation scheme relies on the measurement of the output...
1 GHz GaAs Buck Converter for High Power Amplifier Modulation Applications
Busking, E.B.; Hek, A.P. de; Vliet, F.E. van
2012-01-01
A fully integrated 1 GHz buck converter output stage, including on-chip inductor and DC output filtering has been realized, in a standard high-voltage breakdown GaAs MMIC technology. This is a significant step forward in designing highspeed power control of supply-modulated HPAs (high power
Directory of Open Access Journals (Sweden)
Emad Talib Hashim
2018-02-01
Full Text Available Maximum power point tracking (MPPT is used in photovoltaic (PV systems to enhance efficiency and maximize the output power of PV module, regardless the variation of temperature, irradiation, and the electrical characteristics of the load. A new MPPT system has been presented in this research, consisting of a synchronous DC-DC step-down Buck converter controlled by an Arduino microcontroller based unit. The MPPT process with Perturb and Observe method is performed with a DC-DC converter circuit to overcome the problem of voltage mismatch between the PV modules and the loads. The proposing system has high efficiency, lower cost and can be easily modified to handle more energy sources. The test results indicate that the use of the proposed MPPT control with the designed synchronous Buck converter increases the PV output power; hence increases the overall solar system efficiency. The synchronous Buck converter test results used in this design showed high converter efficiency up to 95% of the power produced from the solar module, leading to reduce power loss caused by the power transfer process from PV module to the loads.
A Two-Phase Buck Converter with Optimum Phase Selection for Low Power Applications
Yeago, Taylor Craig
2015-01-01
Power consumption of smart cameras varies significantly between sleep mode and active mode, and a smart camera operates in sleep mode for 80 ��" 90% of time for typical use. To prolong the battery life of smart cameras, it is essential to increase the power converter efficiency for light load, while being able to manage heavy load. The power stage of traditional buck converter is optimized for maximum load, at the cost of light-load efficiency. Wei proposed a multiphase buck converter incorpo...
Simulation analysis of cascade controller for DC-DC bank converter
International Nuclear Information System (INIS)
Mahar, M.A.; Abro, M.R.; Larik, A.S.
2009-01-01
Power electronic converters are periodic variable structure systems due to their switched operation. During the last few decades several new dc-dc converter topologies have emerged. Buck converter being simple in topology, has recently drawn attraction of many researchers. Basically, a buck converter is highly underdamped system. In order to overcome the developed oscillations in output of this converter, various control techniques have been proposed. However, these techniques are fraught with many drawbacks. This paper focus on a cascade controller based buck topology. Steady state analysis is given in this paper which shows output voltage and inductor current in detail. Dynamic analysis for line and load variation is also presented. The buck topology is implemented and simulated in MATLAB/Simulink. The simulated results are presented. (author)
FPA Tuned Fuzzy Logic Controlled Synchronous Buck Converter for a Wave/SC Energy System
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SAHIN, E.
2017-02-01
Full Text Available This paper presents a flower pollination algorithm (FPA tuned fuzzy logic controlled (FLC synchronous buck converter (SBC for an integrated wave/ supercapacitor (SC hybrid energy system. In order to compensate the irregular wave effects on electrical side of the wave energy converter (WEC, a SC unit charged by solar panels is connected in parallel to the WEC system and a SBC is controlled to provide more reliable and stable voltage to the DC load. In order to test the performance of the designed FLC, a classical proportional-integral-derivative (PID controller is also employed. Both of the controllers are optimized by FPA which is a pretty new optimization algorithm and a well-known optimization algorithm of which particle swarm optimization (PSO to minimize the integral of time weighted absolute error (ITAE performance index. Also, the other error-based objective functions are considered. The entire energy system and controllers are developed in Matlab/Simulink and realized experimentally. Real time applications are done through DS1104 Controller Board. The simulation and experimental results show that FPA tuned fuzzy logic controller provides lower value performance indices than conventional PID controller by reducing output voltage sags and swells of the wave/SC energy system.
Buck-Boost/Forward Hybrid Converter for PV Energy Conversion Applications
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Sheng-Yu Tseng
2014-01-01
Full Text Available This paper presents a charger and LED lighting (discharger hybrid system with a PV array as its power source for electronic sign indicator applications. The charger adopts buck-boost converter which is operated in constant current mode to charge lead-acid battery and with the perturb and observe method to extract maximum power of PV arrays. Their control algorithms are implemented by microcontroller. Moreover, forward converter with active clamp circuit is operated in voltage regulation condition to drive LED for electronic sign applications. To simplify the circuit structure of the proposed hybrid converter, switches of two converters are integrated with the switch integration technique. With this approach, the proposed hybrid converter has several merits, which are less component counts, lighter weight, smaller size, and higher conversion efficiency. Finally, a prototype of LED driving system under output voltage of 10 V and output power of 20 W has been implemented to verify its feasibility. It is suitable for the electronic sign indicator applications.
DEFF Research Database (Denmark)
Yang, Xi-jun; Qu, Hao; Yao, Chen
2014-01-01
As for high power plasma power supply, due to high efficiency and flexibility, multi-channel interleaved multi-stage paralleled Buck DC-DC Converter becomes the first choice. In the paper, two-channel interleaved two- stage paralleled Buck DC-DC Converter powered by three-phase AC power supply...
Simulation and Implementation a Non-Isolated Buck Converter at ZCS Condition
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Nahid Hematian
2013-10-01
Full Text Available A new soft-switching resonant inverting-buck converter with high efficiency is presented. The proposed converter steps down and inverts the input voltage. The zero-current-switching (ZCS technique is employed to reduce switching losses and Electromagnetic Interferences (EMI. An LLC resonant network is utilized to provide soft-switching conditions for all semiconductor devices. Experimental results verify the integrity of the proposed converter operation and the presented theoretical analysis.
Directory of Open Access Journals (Sweden)
Yali Xiong
2008-01-01
Full Text Available This paper investigates the performance perspectives and theoretical limitations of trench power MOSFETs in synchronous rectifier buck converters operating in the MHz frequency range. Several trench MOSFET technologies are studied using a mixed-mode device/circuit modeling approach. Individual power loss contributions from the control and synchronous MOSFETs, and their dependence on switching frequency between 500 kHz and 5 MHz are discussed in detail. It is observed that the conduction loss contribution decreases from 40% to 4% while the switching loss contribution increases from 60% to 96% as the switching frequency increases from 500 KHz to 5 MHz. Beyond 1 MHz frequency there is no obvious benefit to increase the die size of either SyncFET or CtrlFET. The RDS(ON×QG figure of merit (FOM still correlates well to the overall converter efficiency in the MHz frequency range. The efficiency of the hard switching buck topology is limited to 80% at 2 MHz and 65% at 5 MHz even with the most advanced trench MOSFET technologies.
A current-mode DC—DC buck converter with adaptive zero compensation
International Nuclear Information System (INIS)
Yang Ling; Dai Guoding; Xu Chongwei; Liu Yuezhi
2013-01-01
To achieve fast transient response for a DC—DC buck converter, an adaptive zero compensation circuit is presented. The compensation resistance is dynamically adjusted according to the different output load conditions, and achieves an adequate system phase margin under the different conditions. An improved capacitor multiplier circuit is adopted to realize the minimized compensation capacitance size. In addition, analysis of the small-signal model shows the correctness of the mechanism of the proposed adaptive zero compensation technique. A current-mode DC—DC buck converter with the proposed structure has been implemented in a 0.35 μm CMOS process, and the die size is only 800 × 1040 μm 2 . The experimental results show that the transient undershoot/overshoot voltage and the recovery times do not exceed 40 mV and 30 μs for a load current variation from 100 mA to 1 A. (semiconductor integrated circuits)
Application handbook for a Standardized Control Module (SCM) for DC-DC converters, volume 1
Lee, F. C.; Mahmoud, M. F.; Yu, Y.
1980-04-01
The standardized control module (SCM) was developed for application in the buck, boost and buck/boost DC-DC converters. The SCM used multiple feedback loops to provide improved input line and output load regulation, stable feedback control system, good dynamic transient response and adaptive compensation of the control loop for changes in open loop gain and output filter time constraints. The necessary modeling and analysis tools to aid the design engineer in the application of the SCM to DC-DC Converters were developed. The SCM functional block diagram and the different analysis techniques were examined. The average time domain analysis technique was chosen as the basic analytical tool. The power stage transfer functions were developed for the buck, boost and buck/boost converters. The analog signal and digital signal processor transfer functions were developed for the three DC-DC Converter types using the constant on time, constant off time and constant frequency control laws.
Application handbook for a Standardized Control Module (SCM) for DC-DC converters, volume 1
Lee, F. C.; Mahmoud, M. F.; Yu, Y.
1980-01-01
The standardized control module (SCM) was developed for application in the buck, boost and buck/boost DC-DC converters. The SCM used multiple feedback loops to provide improved input line and output load regulation, stable feedback control system, good dynamic transient response and adaptive compensation of the control loop for changes in open loop gain and output filter time constraints. The necessary modeling and analysis tools to aid the design engineer in the application of the SCM to DC-DC Converters were developed. The SCM functional block diagram and the different analysis techniques were examined. The average time domain analysis technique was chosen as the basic analytical tool. The power stage transfer functions were developed for the buck, boost and buck/boost converters. The analog signal and digital signal processor transfer functions were developed for the three DC-DC Converter types using the constant on time, constant off time and constant frequency control laws.
Integrated power electronic converters and digital control
Emadi, Ali; Nie, Zhong
2009-01-01
Non-isolated DC-DC ConvertersBuck ConverterBoost ConverterBuck-Boost ConverterIsolated DC-DC ConvertersFlyback ConverterForward ConverterPush-Pull ConverterFull-Bridge ConverterHalf-Bridge ConverterPower Factor CorrectionConcept of PFCGeneral Classification of PFC CircuitsHigh Switching Frequency Topologies for PFCApplication of PFC in Advanced Motor DrivesIntegrated Switched-Mode Power ConvertersSwitched-Mode Power SuppliesThe Concept of Integrated ConverterDefinition of Integrated Switched-Mode Power Supplies (ISMPS)Boost-Type Integrated TopologiesGeneral Structure of Boost-Type Integrated T
Directory of Open Access Journals (Sweden)
Fredy Edimer Hoyos Velasco
2011-02-01
Full Text Available En este trabajo se estudia el comportamiento de un convertidor electrónico en configuración buck-boost. Elobjetivo del controlador es hacer el rastreo de señales sinusoidales usando un controlador con histéresiscero, es decir que el usuario pueda tener a la salida cualquier señal a un nivel más alto de potencia y conla característica que esta señal deseada es regulada variable en frecuencia, en amplitud y forma de onda.El controlador es rápido pues se comprobó en el laboratorio que ante perturbaciones en la carga y en laseñal de referencia, se comporta adecuadamente. Se implementó el convertidor usando un inversormonofásico en configuración de medio puente y se controla el sistema con un prototipo rápido de control(RCP DS1104 en tiempo real. In this work, we analysed the behaviour of a buck-boost electronic converter. The objective of the zerohysteresis controller is to track user defined sinusoidal signals, usually featuring high power level andvariable frequency, amplitude and wave form. The controller was implemented in the laboratory, whereload and reference signal disturbances were introduced. The controller achieved a fast and adequatebehaviour. The converter was implemented using a half bridge monophasic inverter, and a rapid controlprototyping (RCP DS1104 in real time for the control task.
A Novel Application of Zero-Current-Switching Quasiresonant Buck Converter for Battery Chargers
Directory of Open Access Journals (Sweden)
Kuo-Kuang Chen
2011-01-01
Full Text Available The main purpose of this paper is to develop a novel application of a resonant switch converter for battery chargers. A zero-current-switching (ZCS converter with a quasiresonant converter (QRC was used as the main structure. The proposed ZCS dc–dc battery charger has a straightforward structure, low cost, easy control, and high efficiency. The operating principles and design procedure of the proposed charger are thoroughly analyzed. The optimal values of the resonant components are computed by applying the characteristic curve and electric functions derived from the circuit configuration. Experiments were conducted using lead-acid batteries. The optimal parameters of the resonance components were determined using the load characteristic curve diagrams. These values enable the battery charger to turn on and off at zero current, resulting in a reduction of switching losses. The results of the experiments show that when compared with the traditional pulse-width-modulation (PWM converter for a battery charger, the buck converter with a zero- current-switching quasiresonant converter can lower the temperature of the activepower switch.
Solid state light source driver establishing buck or boost operation
Palmer, Fred
2017-08-29
A solid state light source driver circuit that operates in either a buck convertor or a boost convertor configuration is provided. The driver circuit includes a controller, a boost switch circuit and a buck switch circuit, each coupled to the controller, and a feedback circuit, coupled to the light source. The feedback circuit provides feedback to the controller, representing a DC output of the driver circuit. The controller controls the boost switch circuit and the buck switch circuit in response to the feedback signal, to regulate current to the light source. The controller places the driver circuit in its boost converter configuration when the DC output is less than a rectified AC voltage coupled to the driver circuit at an input node. The controller places the driver circuit in its buck converter configuration when the DC output is greater than the rectified AC voltage at the input node.
A Tapped-Inductor Buck-Boost Converter for a Dielectric ElectroActive Polymer Generator
DEFF Research Database (Denmark)
Dimopoulos, Emmanouil; Munk-Nielsen, Stig
2014-01-01
of commercially-available, high-efficient, high-voltage, low-power semiconductor devices. In this paper, a high-efficient bidirectional tapped-inductor buck-boost converter, addressing high step-up and high step-down voltage conversion ratios, is proposed for energy harvesting applications based on DEAP...
The application of standardized control and interface circuits to three dc to dc power converters.
Yu, Y.; Biess, J. J.; Schoenfeld, A. D.; Lalli, V. R.
1973-01-01
Standardized control and interface circuits were applied to the three most commonly used dc to dc converters: the buck-boost converter, the series-switching buck regulator, and the pulse-modulated parallel inverter. The two-loop ASDTIC regulation control concept was implemented by using a common analog control signal processor and a novel digital control signal processor. This resulted in control circuit standardization and superior static and dynamic performance of the three dc-to-dc converters. Power components stress control, through active peak current limiting and recovery of switching losses, was applied to enhance reliability and converter efficiency.
Simple-topology switched-mode DC-DC converters : dynamics and control
Wertelaers, P
2018-01-01
After a rehearsal of the functioning mode and characteristics of the buck-boost and buck converters, we attempt to formalize a lower-frequency description of the converter, by smoothing the waveforms containing switching ripple. This framework enables the construction of a linear time-invariant computational model, to which voltage-regulating actions can then be added. Emphasis is on the buck converter.
Predictive Trailing-Edge Modulation Average Current Control in DC-DC Converters
Directory of Open Access Journals (Sweden)
LASCU, D.
2013-11-01
Full Text Available The paper investigates predictive digital average current control (PDACC in dc/dc converters using trailing-edge modulation (TEM. The study is focused on the recurrence duty cycle equation and then stability analysis is performed. It is demonstrated that average current control using trailing-edge modulation is stable on the whole range of the duty cycle and thus design problems are highly reduced. The analysis is carried out in a general manner, independent of converter topology and therefore the results can then be easily applied for a certain converter (buck, boost, buck-boost, etc.. The theoretical considerations are confirmed for a boost converter first using the MATLAB program based on state-space equations and finally with the CASPOC circuit simulation package.
Maximum Power Point Tracking menggunakan Buck Converter dengan Algoritma P & O untuk Turbin Angin
Directory of Open Access Journals (Sweden)
Erik Tridianto
2016-12-01
Full Text Available Energi terbarukan adalah salah satu energi alternatif sebagai pengganti bahan bakar untuk pembangkit listrik. Dari berbagai energi terbarukan,yang ada energi angin adalah yang paling mudah dicari. Indonesia merupakan negara kepulauan dengan ratusan pantai dan dengan kecepatan angin yang besar dan berfluktuasi 3-5 m / s. Dan solusi dari masalah angin yang berfluktuasi ini adalah dengan menggunakan kontrol MPPT (Maximum Power Point Tracking dengan lm2596 dc-dc buck converter. Ketika daya yang dihasilkan kurang dari yang diharapkan, maka kontrol MPPT akan menurunkan tegangan untuk mendapatkan daya maksimum. Penelitian ini dilakukan dengan menggunakan lm2596 buck dc-dc converter menggunakan kontrol MPPT dengan tujuan mendapatkan daya maksimum pada kondisi kecepatan angin yang bervariasi, dan jenis MPPT yang digunakan adalah Perturb and Observation (P & O. Untuk membaca daya yang dihasilkan menggunakan Voltage dan Current sensor. Hasil tes menunjukkan bahwa, dengan penambahan kontrol MPPT dapat meningkatkan output daya dari generator sebesar 23%-49%.
Informational model verification of ZVS Buck quasi-resonant DC-DC converter
Vakovsky, Dimiter; Hinov, Nikolay
2016-12-01
The aim of the paper is to create a polymorphic informational model of a ZVS Buck quasi-resonant DC-DC converter for the modeling purposes of the object. For the creation of the model is applied flexible open standards for setting, storing, publishing and exchange of data in distributed information environment. The created model is useful for creation of many and different by type variants with different configuration of the composing elements and different inner model of the examined object.
Research of digital controlled DC/DC converter based on STC12C5410AD
Chen, Dan-Jiang; Jin, Xin; Xiao, Zhi-Hong
2010-02-01
In order to study application of digital control technology on DC/DC converter, principle of increment mode PID control algorithm was analyzed in the paper. Then, a SCM named STC12C5410AD was introduced with its internal resources and characteristics. The PID control algorithm can be implemented easily based on it. The output of PID control was used to change the value of a variable that is 255 times than duty cycle, and this reduced the error of calculation. The valid of the presented algorithm was verified by an experiment for a BUCK DC/DC converter. The experimental results indicated that output voltage of the BUCK converter is stable with low ripple.
A fast novel soft-start circuit for peak current-mode DC—DC buck converters
International Nuclear Information System (INIS)
Li Jie; Yang Miao; Sun Weifeng; Lu Xiaoxia; Xu Shen; Lu Shengli
2013-01-01
A fully integrated soft-start circuit for DC—DC buck converters is presented. The proposed high speed soft-start circuit is made of two sections: an overshoot suppression circuit and an inrush current suppression circuit. The overshoot suppression circuit is presented to control the input of the error amplifier to make output voltage limit increase in steps without using an external capacitor. A variable clock signal is adopted in the inrush current suppression circuit to increase the duty cycle of the system and suppress the inrush current. The DC—DC converter with the proposed soft-start circuit has been fabricated with a standard 0.13 μm CMOS process. Experimental results show that the proposed high speed soft-start circuit has achieved less than 50 μs start-up time. The inductor current and the output voltage increase smoothly over the whole load range. (semiconductor integrated circuits)
Directory of Open Access Journals (Sweden)
Tiara Freitas
2015-09-01
Full Text Available A new application of the three-phase buck-resonant converter is presented in this paper. It is shown that the analyzed converter is suitable to operate as the rectifier stage in low power wind energy conversion systems (WECS based on permanent magnet synchronous generators (PMSG with variable wind speed. As main features, it presents a single controlled switch, simple implementation and control, and operates with a high power factor and low harmonic distortion over all wind speed ranges. The converter topology, its design equations and its operation are presented, as well as the simulation results of the PMSG based conversion system. From the analysis carried out in the paper it is concluded that the converter is indicated to be employed in distributed generation and hybrid systems where wind generation is associated with other sources.
DEFF Research Database (Denmark)
Wu, Weimin; Qin, Weibo; Wang, Houqin
2017-01-01
the “Buck” mode, the control-to-grid current transfer function of this dual “Buck-Boost” AC/DC converter has a movable zero, which is related to the input power and the output DC voltage. When the input power increases, the movable zero will slide to the lower frequency range. And then, the gain between...... the cut-off frequency point and the resonant frequency of LCL filter will swell up, resulting in reduced amplitude margin and suppressed bandwidth of system. Based on the theoretical analysis, a new dynamic pole placement compensation control design method is proposed for this dual AC/DC converter...
A tapped-inductor buck-boost converter for a multi-DEAP generator energy harvesting system
DEFF Research Database (Denmark)
Dimopoulos, Emmanouil; Munk-Nielsen, Stig
2014-01-01
the effective operational range of the power electronic converter. In this paper, a bidirectional tapped-inductor buck-boost converter is proposed, addressing high-efficient high step-up and high step-down voltage conversion ratios, for energy harvesting applications based on DEAP generators. The effective...... operational range of the converter is extended, by replacing its high-side switch with a string of three serialized MOSFETs, to accommodate the need for high-efficient high-voltage operation. Experiments conducted on a single DEAP generator - part of a quadruple DEAP generator energy harvesting system...... with all elements installed sequentially in the same circular disk with a 90 phase shift - validate the applicability of the proposed converter, demonstrating energy harvesting of 0.26 J, at 0.5 Hz and 60 % delta-strain; characterized by an energy density of 1.25 J per kg of active material....
Modelling and Control Design of a Dual Buck-Boost AC/DC Converter Used in the DC Nano-Grid
DEFF Research Database (Denmark)
Wu, Weimin; Liu, Yuan; Wang, Houqing
2016-01-01
Due to widely used DC characterized loads and more distributed power generation sources, the DC Nano-grid becomes more and more popular and seen as an alternative to the AC-grid in future. For the safety considerations, the DC Nano-grid should provide reliable grounding for the residential loads...... like the low voltage AC power system. In this paper, a dual Buck-Boost AC/DC converter for use in the united grounding configuration based DC Nano-grid with three terminal outputs is proposed. It will be much easy to construct an efficient DC Nano-grid based on the existing low AC power system by using...
Application of digital control techniques for satellite medium power DC-DC converters
Skup, Konrad R.; Grudzinski, Pawel; Nowosielski, Witold; Orleanski, Piotr; Wawrzaszek, Roman
2010-09-01
The objective of this paper is to present a work concerning a digital control loop system for satellite medium power DC-DC converters that is done in Space Research Centre. The whole control process of a described power converter bases on a high speed digital signal processing. The paper presents a development of a FPGA digital controller for voltage mode stabilization that was implemented using VHDL. The described controllers are a classical digital PID controller and a bang-bang controller. The used converter for testing is a simple model of 5-20 W, 200 kHz buck power converter. A high resolution digital PWM approach is presented. Additionally a simple and effective solution of filtering of an analog-to-digital converter output is presented.
A Reconfigurable Buck, Boost, and Buck-Boost Converter: Unified Model and Robust Controller
Licea, Martín Antonio Rodríguez; Pinal, Francisco Javier Perez; Gutiérrez, Alejandro Israel Barranco; Ramírez, Carlos Alonso Herrera; Perez, Jose Cruz Nuñez
2018-01-01
The need for reconfigurable, high power density, and low-cost configurations of DC-DC power electronic converters (PEC) in areas such as the transport electrification and the use of renewable energy has spread out the requirement to incorporate in a single circuit several topologies, which generally result in an increment of complexity about the modeling, control, and stability analyses. In this paper, a reconfigurable topology is presented which can be applied in alterative/changing power co...
Single Phase Transformer-less Buck-Boost Inverter with Zero Leakage Current for PV Systems
DEFF Research Database (Denmark)
Mostaan, Ali; Abdelhakim, Ahmed; N. Soltani, Mohsen
2017-01-01
In this paper, a novel single-stage single-phase transformer-less buck-boost inverter is proposed, in which a reduced number of passive components is used. The proposed inverter combines the conventional buck, boost, and buck-boost converters in one converter in order to obtain a sinusoidal output...
A THREE-PHASE BOOST DC-AC CONVERTER
African Journals Online (AJOL)
dc-ac converter (inverter) based on the dc-dc boost converters. ... Sliding mode controllers are designed to perform a robust control for the ... Computer simulations and spectral analysis demon- ... the conventional three-phase buck inverter,.
Bi-Frequency Modulated Quasi-Resonant Converters: Theory and Applications
Zhang, Yuefeng
1995-01-01
To avoid the variable frequency operation of quasi -resonant converters, many soft-switching PWM converters have been proposed, all of them require an auxiliary switch, which will increase the cost and complexity of the power supply system. In this thesis, a new kind of technique for quasi -resonant converters has been proposed, which is called the bi-frequency modulation technique. By operating the quasi-resonant converters at two switching frequencies, this technique enables quasi-resonant converters to achieve the soft-switching, at fixed switching frequencies, without an auxiliary switch. The steady-state analysis of four commonly used quasi-resonant converters, namely, ZVS buck, ZCS buck, ZVS boost, and ZCS boost converter has been presented. Using the concepts of equivalent sources, equivalent sinks, and resonant tank, the large signal models of these four quasi -resonant converters were developed. Based on these models, the steady-state control characteristics of BFM ZVS buck, BFM ZCS buck, BFM ZVS boost, and BFM ZCS boost converter have been derived. The functional block and design consideration of the bi-frequency controller were presented, and one of the implementations of the bi-frequency controller was given. A complete design example has been presented. Both computer simulations and experimental results have verified that the bi-frequency modulated quasi-resonant converters can achieve soft-switching, at fixed switching frequencies, without an auxiliary switch. One of the application of bi-frequency modulation technique is for EMI reduction. The basic principle of using BFM technique for EMI reduction was introduced. Based on the spectral analysis, the EMI performances of the PWM, variable-frequency, and bi-frequency modulated control signals was evaluated, and the BFM control signals show the lowest EMI emission. The bi-frequency modulated technique has also been applied to the power factor correction. A BFM zero -current switching boost converter has
DEFF Research Database (Denmark)
Andersen, Karsten Holm; Nymand, Morten
2017-01-01
) and discontinuous conduction mode (DCM) and supports high switching frequencies even with low cost A/D converters. The proposed controller is implemented in a Field Programmable Gate Array (FPGA) to control a 450 W buck converter and the experimental results verify the controller's capability to operate in the full...
Directory of Open Access Journals (Sweden)
S. Shiva Kumar
2015-06-01
Full Text Available In this paper, a Zero-Voltage-Transition (ZVT–Zero-Current Transition (ZCT Pulse-width Modulated (PWM synchronous buck converter (SBC, with a simple passive auxiliary circuit is proposed, which reduces the stresses and improves the efficiency by pacifying the conduction losses compared to a traditional PWM converter, typically suitable for photovoltaic applications. The important design feature of ZVT–ZCT PWM SBC converters is placement of resonant components that mollifies the conduction losses. Due to the ZVT–ZCT, the resonant components with low values are used, thereby resulting in the increase of switching frequency. The ZVT–ZCT operation of the proposed converter is presented through theoretical analysis. The characteristics of the proposed converter are verified with the simulation in the PSIM co-simulated with MATLAB/SIMULINK environment and implemented experimentally.
Digitally Controlled Point of Load Converter with Very Fast Transient Response
DEFF Research Database (Denmark)
Jakobsen, Lars Tønnes; Andersen, Michael Andreas E.
2007-01-01
voltage mode control and very fast transient response. The DiSOM modulator is combined with a digital PID compensator algorithm is implemented in a hybrid CPLD/FPGA and is used to control a synchronous Buck converter, which is used in typical Point of Load applications. The computational time is only......This paper presents a new Digital Self-Oscillating Modulator (DiSOM) that allows the duty cycle to be changed instantly. The DiSOM modulator is shown to have variable switching that is a function of the duty cycle. Compared to a more traditional digital PWM modulator based on a counter...... and comparator the DiSOM modulator allows the sampling frequency of the output voltage control loop to be higher than the switching frequency of the power converter, typically a DC/DC converter. The features of the DiSOM modulator makes it possible to design a digitally controlled DC/DC converter with linear...
Bifurcation-free design method of pulse energy converter controllers
International Nuclear Information System (INIS)
Kolokolov, Yury; Ustinov, Pavel; Essounbouli, Najib; Hamzaoui, Abdelaziz
2009-01-01
In this paper, a design method of pulse energy converter (PEC) controllers is proposed. This method develops a classical frequency domain design, based on the small signal modeling, by means of an addition of a nonlinear dynamics analysis stage. The main idea of the proposed method consists in fact that the PEC controller, designed with an application of the small signal modeling, is tuned after with taking into the consideration an essentially nonlinear nature of the PEC that makes it possible to avoid bifurcation phenomena in the PEC dynamics at the design stage (bifurcation-free design). Also application of the proposed method allows an improvement of the designed controller performance. The application of this bifurcation-free design method is demonstrated on an example of the controller design of direct current-direct current (DC-DC) buck converter with an input electromagnetic interference filter.
Bifurcation and chaos in high-frequency peak current mode Buck converter
Chang-Yuan, Chang; Xin, Zhao; Fan, Yang; Cheng-En, Wu
2016-07-01
Bifurcation and chaos in high-frequency peak current mode Buck converter working in continuous conduction mode (CCM) are studied in this paper. First of all, the two-dimensional discrete mapping model is established. Next, reference current at the period-doubling point and the border of inductor current are derived. Then, the bifurcation diagrams are drawn with the aid of MATLAB. Meanwhile, circuit simulations are executed with PSIM, and time domain waveforms as well as phase portraits in i L-v C plane are plotted with MATLAB on the basis of simulation data. After that, we construct the Jacobian matrix and analyze the stability of the system based on the roots of characteristic equations. Finally, the validity of theoretical analysis has been verified by circuit testing. The simulation and experimental results show that, with the increase of reference current I ref, the corresponding switching frequency f is approaching to low-frequency stage continuously when the period-doubling bifurcation happens, leading to the converter tending to be unstable. With the increase of f, the corresponding I ref decreases when the period-doubling bifurcation occurs, indicating the stable working range of the system becomes smaller. Project supported by the National Natural Science Foundation of China (Grant No. 61376029), the Fundamental Research Funds for the Central Universities, China, and the College Graduate Research and Innovation Program of Jiangsu Province, China (Grant No. SJLX15_0092).
Three new DC-to-DC Single-Switch Converters
Directory of Open Access Journals (Sweden)
Barry W. Williams
2017-06-01
Full Text Available This paper presents a new family of three previously unidentified dc-to-dc converters, buck, boost, and buck-boost voltage-transfer-function topologies, which offer advantageous transformer coupling features and low capacitor dc voltage stressing. The three single-switch, single-diode, converters offer the same features as basic dc-to-dc converters, such as the buck function with continuous output current and the boost function with continuous input current. Converter time-domain simulations and experimental results (including transformer coupling support and extol the dc-to-dc converter concepts and analysis presented.
A New Sliding Mode Controller for DC/DC Converters in Photovoltaic Systems
Directory of Open Access Journals (Sweden)
M. Sarvi
2013-01-01
Full Text Available DC/DC converters are widely used in many industrial and electrical systems. As DC/DC converters are nonlinear and time-variant systems, the application of linear control techniques for the control of these converters is not suitable. In this paper, a new sliding mode controller is proposed as the indirect control method and compared to a simple direct control method in order to control a buck converter in photovoltaic applications. The solar arrays are dependent power sources with nonlinear voltage-current characteristics under different environmental conditions (insolation and temperature. From this point of view, the DC/DC converter is particularly suitable for the application of the sliding mode control in photovoltaic application, because of its controllable states. Simulations are performed in Matlab/Simulink software. The simulation results are presented for a step change in reference voltage and input voltage as well as step load variations. The simulations results of proposed method are compared with the conventional PID controller. The results show the good performance of the proposed sliding mode controller. The proposed method can be used for the other DC/DC converter.
Direct switching control of DC-DC power electronic converters using hybrid system theory
Energy Technology Data Exchange (ETDEWEB)
Zhao, J.; Lin, F. [Wayne State Univ., Detroit, MI (United States). Dept. of Electrical and Computer Engineering; Wang, C. [Wayne State Univ., Detroit, MI (United States). Dept. of Electrical and Computer Engineering; Wayne State Univ., Detroit, MI (United States). Div. of Engineering Technology
2010-07-01
A direct switching control (DSC) scheme for power electronics converters was described. The system was designed for use in both traditional and renewable energy applications as well as in electric drive vehicles. The proposed control scheme was based on a detailed hybrid system converter model that used model predictive control (MPC), piecewise affine (PWA) approximations and constrained optimal control methods. A DC-DC converter was modelled as a hybrid machine. Switching among different modes of the DC-DC converter were modelled as discrete events controlled by the hybrid controller. The modelling scheme was applied to a Buck converter. The DSC was used to control the switch of the power converter based on a hybrid machine model. Results of the study showed that the method can be used to regulate output voltage and inductor currents. The method also provides fast transient responses and effectively regulates both currents and voltage. The controller can be used to provide immediate responses to dynamic disturbances and output voltage fluctuations. 23 refs., 7 figs.
Directory of Open Access Journals (Sweden)
Muhamad Otong
2017-05-01
Full Text Available In this paper, the implementation of the Maximum Power Point Tracking (MPPT technique is developed using buck-boost converter. Perturb and observe (P&O MPPT algorithm is used to searching maximum power from the wind power plant for charging of the battery. The model used in this study is the Variable Speed Wind Turbine (VSWT with a Permanent Magnet Synchronous Generator (PMSG. Analysis, design, and modeling of wind energy conversion system has done using MATLAB/simulink. The simulation results show that the proposed MPPT produce a higher output power than the system without MPPT. The average efficiency that can be achieved by the proposed system to transfer the maximum power into battery is 90.56%.
Start Up Current Control of Buck-Boost Convertor-Fed Serial DC Motor
Directory of Open Access Journals (Sweden)
Yusuf SÖNMEZ
2009-02-01
Full Text Available Generally, DC motors are given preference for industrial applications such as electric locomotives, cranes, goods lifts. Because of they have high starting moment; they initially start with high current. This high start-up current must be decreased since it may damage windings of the motor and increases power consumption. It could be controlled by an appropriate driver system and controller. The nature of fuzzy logic control has adaptive characteristics that can achieve robust response to a system with uncertainty, parameter variation, and load disturbance. In this paper, fuzzy logic based control of start-up current of a Buck-Boost Converter fed serial DC motor is examined through computer simulation. In order to see the advantages of fuzzy logic control, classical PI control has applied to the same motor, under same circumstances and has been compared. C++ Builder software has been used for the simulation. According to the simulation results, plainly, fuzzy logic control has stronger responses than classical PI control and uses lower current at starting moment.
Analysis of the Coupling Behavior of PEM Fuel Cells and DC-DC Converters
Directory of Open Access Journals (Sweden)
Achim Kienle
2009-03-01
Full Text Available The connection between PEM fuel cells and common DC-DC converters is examined. The analysis is model-based and done for boost, buck and buck-boost converters. In a first step, the effect of the converter ripples upon the PEM fuel cell is shown. They introduce oscillations in the fuel cell. Their appearance is explained, discussed and possibilities for their suppression are given. After that, the overall behaviors of the coupled fuel cell-converter systems are analyzed. It is shown, that neither stationary multiplicities nor oscillations can be introduced by the couplings and therefore separate control approaches for both the PEMFC and the DC-DC converters are applicable.
Energy Technology Data Exchange (ETDEWEB)
Amjadi, Zahra; Williamson, Sheldon
2010-09-15
This paper presents the analysis and novel hybrid controller design for an interleaved 2-quadrant switched capacitor (SC) bidirectional DC/DC converter for a hybrid electric vehicle (HEV) dual energy storage system. The designed novel control strategy enables simpler dynamics compared to a standard buck converter with input filter, good regulation capability, low EMI, lower source current ripple, ease of control, and continuous input current waveform in both buck as well as boost modes of operation.
Design of DC-DC Converter and its Control for a Wind Generation System Connected to an Isolated Load
Directory of Open Access Journals (Sweden)
Carlos A. Ramírez Gómez
2013-11-01
Full Text Available A method to design a Buck converter and its control, which are associated to a wind generation system that is feeding an isolated load, is presented in this paper. To design the converter a Thevenin equivalent is deduced, which represents the behavior of the wind turbine, the permanent magnet synchronous generator, and the rectifier. The design of the converter elements guarantees input/output voltages and inductor current ripples of 5 % or less. The output voltage control is developed with a proportional-integral-derivative controller and as design criteria a damping of 0,707 and cutoff frequency of 1/5 converter commutation frequency are selected. The designed controller regulates the output voltage faced load perturbations and wind speed variations.
Common mode noise in three-level DC-DC converters
CSIR Research Space (South Africa)
Grobler, Inus
2009-09-01
Full Text Available that three-level buck DC-DC converters in general generate much lower common mode currents than conventional two-level buck converters. Further, reductions in common mode currents are achieved by using the improved three-level topologies that have been...
Two-inductor boost and buck converters
White, J. L.; Muldoon, W. J.
The derivation, analysis and design of a coupled inductor boost converter is presented. Aspects of the qualitative ac behavior of coupled inductor converters are discussed. Considerations for the design of the magnetics for such converters are addressed.
A High Step-Down Interleaved Buck Converter with Active-Clamp Circuits for Wind Turbines
Directory of Open Access Journals (Sweden)
Chih-Lung Shen
2012-12-01
Full Text Available In this paper, a high step-down interleaved buck coupled-inductor converter (IBCC with active-clamp circuits for wind energy conversion has been studied. In high step-down voltage applications, an IBCC can extend duty ratio and reduce voltage stresses on active switches. In order to reduce switching losses of active switches to improve conversion efficiency, a IBCC with soft-switching techniques is usually required. Compared with passive-clamp circuits, the IBCC with active-clamp circuits have lower switching losses and minimum ringing voltage of the active switches. Thus, the proposed IBCC with active-clamp circuits for wind energy conversion can significantly increase conversion efficiency. Finally, a 240 W prototype of the proposed IBCC with active-clamp circuits was built and implemented. Experimental results have shown that efficiency can reach as high as 91%. The proposed IBCC with active-clamp circuits is presented in high step-down voltage applications to verify the performance and the feasibility for energy conversion of wind turbines.
Directory of Open Access Journals (Sweden)
S. Zahra Mirbagheri Golroodbari
2018-01-01
Full Text Available Partial shading has a nonlinear effect on the performance of photovoltaic (PV modules. Different methods of optimizing energy harvesting under partial shading conditions have been suggested to mitigate this issue. In this paper, a smart PV module architecture is proposed for improvement of shade resilience in a PV module consisting of 60 silicon solar cells, which compensates the current drops caused by partial shading. The architecture consists of groups of series-connected solar cells in parallel to a DC-DC buck converter. The number of cell groups is optimized with respect to cell and converter specifications using a least-squares support vector machine method. A generic model is developed to simulate the behavior of the smart architecture under different shading patterns, using high time resolution irradiance data. In this research the shading patterns are a combination of random and pole shadows. To investigate the shade resilience, results for the smart architecture are compared with an ideal module, and also ordinary series and parallel connected architectures. Although the annual yield for the smart architecture is 79.5% of the yield of an ideal module, we show that the smart architecture outperforms a standard series connected module by 47%, and a parallel architecture by 13.4%.
Escobar, Gerardo; Schaft, Arjan J. van der; Ortega, Romeo
1999-01-01
In this paper we show how, using the Hamiltonian formalism, we can systematically derive mathematical models that describe the behaviour of a large class of switching power converters, including the "Boost", "Buck", "Buck-Boost", "Čuk" and "Flyback" converters. We follow the approach earlier
Design and Simulation to Composite PI Controller on the Stratospheric Airship
Kangwen Sun; Ming Zhu; Bojin Qi; Xiaoming Chen
2014-01-01
In view of the stratospheric airship application requirements on energy storage and management system, based on the topology of DC/DC converter main circuit, the composite PI controller is designed to realize respective control with the Boost mode and Buck mode. Furthermore, limit stop integration method is proposed to achieve a buck-boost complex DC/DC converter boost with effective switching buck. Then, with the MATLAB Control System Toolbox design model, the composite PI controller design ...
Component-Minimized Buck-Boost Voltage Source Inverters
DEFF Research Database (Denmark)
Gao, F.; Loh, P.C.; Blaabjerg, Frede
2007-01-01
This paper presents the design of buck-boost B4 inverters that can be derived from either Ćuk- or SEPIC-derived buck-boost B6 inverters. Unlike traditional inverters, the integration of front-end voltage boost circuitry and inverter circuitry allows it to perform buck-boost voltage inversion...... between capacitors. Modulation wise, the proposed buck-boost B4 inverters can be controlled using a carefully designed carrier-based pulse-width modulation (PWM) scheme that will always ensure balanced threephase outputs as desired, while simultaneously achieving minimal voltage stress across...
Multi-cell DC-DC converters : modelling, analysis and control
International Nuclear Information System (INIS)
Feki, M.; El Aroudi, A.; Robert, B.G.M.
2011-01-01
This paper is devoted to modeling of a two-cell DC/DC buck converter, to the analysis of its behavior and to the design of control methods that yield to improve its performances. Various numerical simulations and dynamical aspects of this system are illustrated in the time domain and in the parameter space. Without control, the system may present many undesirable behaviors such as sub-harmonics and chaotic oscillations. The proposed controllers are able to widen the stability range of the system. Optimum values of parameters giving rise to fast response while maintaining stable periodic behavior are given in closed form. However, it is detected that in a certain region of the parameter space, the stabilized periodic orbit may coexist with a chaotic attractor. Boundary between basins of attraction are obtained by means of numerical simulations.
Design and Analysis of Two-Phase Boost DC-DC Converter
Taufik Taufik; Tadeus Gunawan; Dale Dolan; Makbul Anwari
2010-01-01
Multiphasing of dc-dc converters has been known to give technical and economical benefits to low voltage high power buck regulator modules. A major advantage of multiphasing dc-dc converters is the improvement of input and output performances in the buck converter. From this aspect, a potential use would be in renewable energy where power quality plays an important factor. This paper presents the design of a 2-phase 200W boost converter for battery charging application. Analysis of results fr...
DEFF Research Database (Denmark)
Bhaskar, Mahajan Sagar; Sanjeevikumar, Padmanaban; Wheeler, Patrick
2016-01-01
A New breed of a buck boost converter, named as the XY converter family is proposed in this article. In the XY family, 16 topologies are presented which are highly suitable for renewable energy applications which require a high ratio of DC-DC converter; such as a photovoltaic multilevel inverter...... system, high voltage automotive applications and industrial drives. Compared to the traditional boost converter and existing recent converters, the proposed XY converter family has the ability to provide a higher output voltage by using less number of power devices and reactive components. Other distinct...... features of the XY converter family are i) Single control switch ii) Provide negative output voltage iii) Non-isolated topologies iv) High conversion ratio without making the use of high duty cycle and v) modular structure. XY family is compared with the recent high step-up converters and the detailed...
Analysis and Controller Design of a Universal Bidirectional DC-DC Converter
Directory of Open Access Journals (Sweden)
Kou-Bin Liu
2016-06-01
Full Text Available In this paper, first the operating principles of a non-isolated universal bidirectional DC-DC converter are studied and analyzed. The presented power converter is capable of operating in all power transferring directions in buck/boost modes. Zero voltage switching can be achieved for all the power switches through proper modulation strategy design, therefore, the presented converter can achieve high efficiency. To further improve the efficiency, the relationship between the phase-shift angle and the overall system efficiency is analyzed in detail, an adaptive phase-shift (APS control method which determines the phase-shift value between gating signals according to the load level is then proposed. As the modulation strategy is a software-based solution, there is no requirement for additional circuits, therefore, it can be implemented easily and instability and noise susceptibility problems can be reduced. To validate the correctness and the effectiveness of the proposed method, a 300 W prototyping circuit is implemented and tested. A low cost dsPIC33FJ16GS502 digital signal controller is adopted in this paper to realize the power flow control, DC-bus voltage regulation and APS control. According to the experimental results, a 12.2% efficiency improvement at light load and 4.0% efficiency improvement at half load can be achieved.
Modeling, Analysis and Control of Different DC-DC Converter Topologies for Photo Voltaic Emulator
Directory of Open Access Journals (Sweden)
Mohammad Tauquir Iqbal
2016-05-01
Full Text Available This paper presents the modeling, analysis and control of different DC-DC converter topologies to emulate the photovoltaic (PV system. A PV emulator is basically a DC-DC converter having same electrical characteristics that of solar PV panel. The emulator helps to achieve real characteristics of PV system in a better way in an environment where using actual PV systems can produce inconsistent results due to variation in weather conditions. The paper describes different types of DC-DC converters like buck, Resonant and Quasi Resonant Converter. The complete system is modelled in MATLAB® Simulink SimPowerSystem software package. The Simulation results obtained from the MATLAB® Simulink SimPowerSystem software package for different topologies under steady and dynamic conditions are analyzed and presented. An evaluation table is also presented at the end of the paper, presenting the effectiveness of each topology.
Unified Subharmonic Oscillation Conditions for Peak or Average Current Mode Control
Fang, Chung-Chieh
2013-01-01
This paper is an extension of the author's recent research in which only buck converters were analyzed. Similar analysis can be equally applied to other types of converters. In this paper, a unified model is proposed for buck, boost, and buck-boost converters under peak or average current mode control to predict the occurrence of subharmonic oscillation. Based on the unified model, the associated stability conditions are derived in closed forms. The same stability condition can be applied to ...
Directory of Open Access Journals (Sweden)
Mohamed Boutouba
2017-12-01
Full Text Available In this paper, a voltage regulation system is proposed for photovoltaic energy sources (PV, using Single-Ended Primary Inductance Converter as a DC-DC converter to feed loads working with specific input voltage. The choose of SEPIC converter is due to the output voltage ripple of developed-type converters are usually small and can be lower than 2%, also it considered as a buck and boost converter and thereafter loads with lower or higher voltage could be powered. Matlab Simulink is used as environment to develop control strategies to guaranties a stable voltage at the loads terminals. Two algorithms are used to fulfill this role: A Conventional PID and PI-Fuzzy logic controller to generate the PWM signal for the SEPIC converter. Hence, to validate the work some real-time simulations are treated by implemented the control strategies on a low-cost control board: The Raspberry Pi 3 in order to manage the operation of system and collecting the simulation data. Also, and for verification purposes, several simulations were treated to verify the good behavior of the proposed system.
Application research of power allocation based on Buck circuit in DC microgrid
Wang Zihao; Zhou Mingyu
2017-01-01
In a traditional DC microgrid, the power sharing control strategy has been always used in the distributed power converters, resulting in not making outer power allocation arbitrarily. In order to solve the power output allocation problem of wind power in DC microgrid, the intelligent Buck circuit based on PI algorithm and the load current feed-forward method was used to realize the arbitrary regulation of the output power of the wind power in the DC microgrid system. Compared with traditional...
State-plane analysis of zero-voltage-switching resonant dc/dc power converters
Kazimierczuk, Marian K.; Morse, William D.
The state-plane analysis technique for the zero-voltage-switching resonant dc/dc power converter family of topologies, namely the buck, boost, buck-boost, and Cuk converters is established. The state plane provides a compression of information that allows the designer to uniquely examine the nonlinear dynamics of resonant converter operation. Utilizing the state plane, resonant converter modes of operation are examined and the switching frequencies are derived for the boundaries between these modes, including the boundary of energy conversion.
Buck-Boost Current-Source Inverters With Diode-Inductor Network
DEFF Research Database (Denmark)
Gao, Feng; Liang, Chao; Loh, Poh Chiang
2009-01-01
This paper presents a number of novel currentsource inverters (CSIs) with enhanced current buck-boost capability. By adding a unique diode-inductor network between the inverter circuitry and current-boost elements, the proposed buck-boost CSIs demonstrate a doubling of current-boost capability......, as compared with other recently reported buck-boost CSIs. For controlling the proposed CSIs, two modulation schemes are designed for achieving either optimized harmonic performance or minimized commutation count without influencing the inverter current buck-boost gain. These theoretical findings were...
Improved Kayaking Ergometer Using a Switch-mode Converter Driven Alternator
DEFF Research Database (Denmark)
Cornaby, Chris; Friberg, Jeppe; Søndergaard, Nikolaj B.
2016-01-01
described. A synchronous-rectified buck converter has been designed to control the current through the rotor and, by extension, the mechanical resistance felt by the oarsman. The circuit was designed to function with a 12V car battery as a supply. Necessary specifications for efficiency and output stability...
dc analysis and design of zero-voltage-switched multi-resonant converters
Tabisz, Wojciech A.; Lee, Fred C.
Recently introduced multiresonant converters (MRCs) provide zero-voltage switching (ZVS) of both active and passive switches and offer a substantial reduction of transistor voltage stress and an increase of load range, compared to their quasi-resonant converter counterparts. Using the resonant switch concept, a simple, generalized analysis of ZVS MRCs is presented. The conversion ratio and voltage stress characteristics are derived for basic ZVS MRCs, including buck, boost, and buck/boost converters. Based on the analysis, a design procedure that optimizes the selection of resonant elements for maximum conversion efficiency is proposed.
Transformerless dc-Isolated Converter
Rippel, Wally E.
1987-01-01
Efficient voltage converter employs capacitive instead of transformer coupling to provide dc isolation. Offers buck/boost operation, minimal filtering, and low parts count, with possible application in photovoltaic power inverters, power supplies and battery charges. In photovoltaic inverter circuit with transformerless converter, Q2, Q3, Q4, and Q5 form line-commutated inverter. Switching losses and stresses nil because switching performed when current is zero.
Analisys of Current-Bidirectional Buck-Boost Based Automotive Switch-Mode Audio Amplifier
DEFF Research Database (Denmark)
Bolten Maizonave, Gert; Andersen, Michael A. E.; Kjærgaard, Claus
2011-01-01
The following study was carried out in order to assess quantitatively the performance of the buck-boost converter when used as switch-mode audio amplifier. It comprises of, to begin with, the delimitation of design criteria based on the state-ofthe- art solution, which is based in a differential ...
Directory of Open Access Journals (Sweden)
Yusuke Hayashi
2016-01-01
Full Text Available An active gate controlled semiconductor protection switch using SiC-MOSFET is proposed to achieve the fault tolerant operation of ISOP (Input Series and Output Parallel connected multicell dc-dc converter. The SiC-MOSFET with high temperature capability simplifies the configuration of the protection circuit, and its on-resistance control by the active gate controller realizes the smooth protection without the voltage and the current surges. The first laboratory prototype of the protection switch is fabricated by using a SiC-MOSFET with a high frequency buck chopper for the active gate controller. The effectiveness of the proposed protection switch is verified, taking the impact of the volume reduction into account.
Liquid Nitrogen Temperature Operation of a Switching Power Converter
Ray, Biswajit; Gerber, Scott S.; Patterson, Richard L.; Myers, Ira T.
1995-01-01
The performance of a 42/28 V, 175 W, 50 kHz pulse-width modulated buck dc/dc switching power converter at liquid nitrogen temperature (LNT) is compared with room temperature operation. The power circuit as well as the control circuit of the converter, designed with commercially available components, were operated at LNT and resulted in a slight improvement in converter efficiency. The improvement in power MOSFET operation was offset by deteriorating performance of the output diode rectifier at LNT. Performance of the converter could be further improved at low temperatures by using only power MOSFET's as switches. The use of a resonant topology will further improve the circuit performance by reducing the switching noise and loss.
Design and Simulation to Composite PI Controller on the Stratospheric Airship
Directory of Open Access Journals (Sweden)
Kangwen Sun
2014-05-01
Full Text Available In view of the stratospheric airship application requirements on energy storage and management system, based on the topology of DC/DC converter main circuit, the composite PI controller is designed to realize respective control with the Boost mode and Buck mode. Furthermore, limit stop integration method is proposed to achieve a buck-boost complex DC/DC converter boost with effective switching buck. Then, with the MATLAB Control System Toolbox design model, the composite PI controller design and a simulation is accomplished. According to the simulation model, the structure and parameters of the controller to the system can be easily adjusted. Finally, by using the average large-signal switching mathematical model to create sub-circuit in place of the actual circuit model, the whole circuit model of the DC/DC converter is constructed with MATLAB, and then, from the analysis of simulation results, it’s proved that the method can shorten the simulation time and obtain better convergence of the target.
Three-Level AC-DC-AC Z-Source Converter Using Reduced Passive Component Count
DEFF Research Database (Denmark)
Loh, Poh Chiang; Gao, Feng; Tan, Pee-Chin
2009-01-01
This paper presents a three-level ac-dc-ac Z-source converter with output voltage buck-boost capability. The converter is implemented by connecting a low-cost front-end diode rectifier to a neutral-point-clamped inverter through a single X-shaped LC impedance network. The inverter is controlled...... to switch with a three-level output voltage, where the middle neutral potential is uniquely tapped from the star-point of a wye-connected capacitive filter placed before the front-end diode rectifier for input current filtering. Through careful control, the resulting converter can produce the correct volt...
Modeling, Development and Control of Multilevel Converters for Power System Application =
Vahedi, Hani
successfully to work in both stand-alone and gridconnected mode of operation. Eventually, a modified configuration of the PUC5 topology is presented to work as a buck PFC rectifier. The internal performance of the rectifier is like a buck converter to generate stepped down DC voltages at the two output terminals while the grid sees a boost converter externally. As well, a decoupled voltage/current controller is designed and applied to balance the output voltages identically and synchronize the input current with grid voltage to have a PFC operation acceptably. A power balance analysis is done to show the load variation range limit. All the theoretical and simulation studies are validated by experimental results completely.
Bridgeless SEPIC PFC Converter for Multistring LED Driver
Jha, Aman; Singh, Bhim
2018-05-01
This paper deals with Power Factor Correction (PFC) in Low Voltage High Current (LVHC) multi-string light emitting diode (LED) using a bridgeless (BL) single ended primary inductance converter (SEPIC). This application is designed for large area LED lighting with illumination control. A multi-mode LED dimming technique is used for the lighting control. The BL-SEPIC PFC converter is used as a load emulator for high power factor. The regulated low voltage from flyback converter is a source power to the synchronous buck converters for multi-string LED driver and forced cooling system for LED junction. The BL-SEPIC PFC converter inductor design is based on Discontinuous Inductor Current Modes (DICM) which provides good PFC at low cost. Test results are found quite satisfactory for universal input AC (90-265 V). There is significant improvement in the power factor and input current Total Harmonic Distortion (THD) with good margin of harmonic limits for lighting IEC 61000-3-2 Class C.
Advanced buck converter power supply ABCPS for APT
International Nuclear Information System (INIS)
Street, R.; Overett, T.; Bowles, E.
1998-01-01
The United States Department of Energy (DOE) is planning to fabricate an Accelerator for the Production of Tritium (APT) at their Savannah River Site, to provide Tritium for national defense. The 1700 million electron volt (MeV) proton beam accelerator will be powered by radio frequency (RF) klystrons. A direct current (DC) power supply is required for each of the approximately two hundred and fifty 1-megawatt (MW) continuous wave klystrons in the RF power system. The requirements are that the power supply meet output performance specifications, provide fault protection for the klystron, have high efficiency, high reliability, good maintainability, and be readily manufacturable. As the power supplies are one of the largest cost elements in the accelerator, a technology review was made to determine the most economical approach to satisfy the requirements. A switch-mode power supply employing a buck-regulator was identified as being potentially the lowest cost approach. As the switch represents a certain development risk, a small-scale prototype has been constructed for evaluation, and has resulted in the decision to fabricate a full-scale prototype power supply. A description of the hardware will be presented
A Single Phase to Three Phase PFC Half-Bridge Converter Using BLDC Drive with SPWM Technique.
Srinu Duvvada; Manmadha Kumar B
2014-01-01
In this paper, a buck half-bridge DC-DC converter is used as a single-stage power factor correction (PFC) converter for feeding a voltage source inverter (VSI) based permanent magnet brushless DC motor (BLDC) drive. The front end of this PFC converter is a diode bridge rectifier (DBR) fed from single-phase AC mains. The BLDC is used to drive a compressor load of an air conditioner through a three-phase VSI fed from a controlled DC link voltage. The speed of the compressor is controlled to ach...
Application research of power allocation based on Buck circuit in DC microgrid
Directory of Open Access Journals (Sweden)
Wang Zihao
2017-01-01
Full Text Available In a traditional DC microgrid, the power sharing control strategy has been always used in the distributed power converters, resulting in not making outer power allocation arbitrarily. In order to solve the power output allocation problem of wind power in DC microgrid, the intelligent Buck circuit based on PI algorithm and the load current feed-forward method was used to realize the arbitrary regulation of the output power of the wind power in the DC microgrid system. Compared with traditional distributed generators power-sharing method, the simulation and experimental results show the proposed method can realize arbitrary power outputting from distributed generators. Finally, the simulation and experimental results prove the validity and effectiveness of the control method.
Multi-level cascaded DC/DC converters for PV applications
Directory of Open Access Journals (Sweden)
Ahmed A.A. Hafez
2015-12-01
Full Text Available A robust multi-level cascaded DC/DC system for Photovoltaic (PV application is advised in this article. There are three PV generators, each is coupled to a half-bridge buck cell. Each PV-generator–buck-converter channel is controlled such that maximum power is captured independently under different irradiation and temperature levels. The system operation under normal and abnormal conditions was comprehensively investigated. Internal Model Control (IMC technique was adopted for tuning the controllers. An elaborate switching modulation strategy was used to reduce the current ripple and inductor size, while maintaining high efficiency. Annotative, simple and robust remedial strategies were proposed to mitigate different anticipated faults. Comprehensive simulation results in Matlab environment were illustrated for corroborating the performance of the advised cascaded DC/DC system under normal/abnormal conditions. The proposed system enjoys the merits of independency, reduced volumetric dimensions and improved efficiency. Furthermore, the system is inherently fault-tolerant.
Large step-down DC-DC converters with reduced current stress
International Nuclear Information System (INIS)
Ismail, Esam H.
2009-01-01
In this paper, several DC-DC converters with large voltage step-down ratios are introduced. A simple modification in the output section of the conventional buck and quadratic converters can effectively extend the duty-cycle range. Only two additional components (an inductor and diode) are necessary for extending the duty-cycle range. The topologies presented in this paper show an improvement in the duty-cycle (about 40%) over the conventional buck and quadratic converters. Consequently, they are well suited for extreme step-down voltage conversion ratio applications. With extended duty-cycle, the current stress on all components is reduced, leading to a significant improvement of the system losses. The principle of operation, theoretical analysis, and comparison of circuit performances with other step-down converters is discussed regarding voltage and current stress. Experimental results of one prototype rated 40-W and operating at 100 kHz are provided in this paper to verify the performance of this new family of converters. The efficiency of the proposed converters is higher than the quadratic converters
Directory of Open Access Journals (Sweden)
Ching-Ming Lai
2016-05-01
Full Text Available The main objective of this paper was to study a bidirectional direct current to direct current converter (BDC topology with a high voltage conversion ratio for electric vehicle (EV batteries connected to a dc-microgrid system. In this study, an unregulated level converter (ULC cascaded with a two-phase interleaved buck-boost charge-pump converter (IBCPC is introduced to achieve a high conversion ratio with a simpler control circuit. In discharge state, the topology acts as a two-stage voltage-doubler boost converter to achieve high step-up conversion ratio (48 V to 385 V. In charge state, the converter acts as two cascaded voltage-divider buck converters to achieve high voltage step-down conversion ratio (385 V to 48 V. The features, operation principles, steady-state analysis, simulation and experimental results are made to verify the performance of the studied novel BDC. Finally, a 500 W rating prototype system is constructed for verifying the validity of the operation principle. Experimental results show that highest efficiencies of 96% and 95% can be achieved, respectively, in charge and discharge states.
A Novel Application of Zero-Current-Switching Quasiresonant Buck Converter for Battery Chargers
Kuo-Kuang Chen
2011-01-01
The main purpose of this paper is to develop a novel application of a resonant switch converter for battery chargers. A zero-current-switching (ZCS) converter with a quasiresonant converter (QRC) was used as the main structure. The proposed ZCS dc–dc battery charger has a straightforward structure, low cost, easy control, and high efficiency. The operating principles and design procedure of the proposed charger are thoroughly analyzed. The optimal values of the resonant components are compute...
International Nuclear Information System (INIS)
Kim, Hui Jun
1993-06-01
This book concentrates on switch mode power supply. It has four parts, which are introduction of switch mode power supply with DC-DC converter such as Buck converter boost converter, Buck-boost converter and PWM control circuit, explanation for SMPS with DC-DC converter modeling and power mode control, resonance converter like resonance switch, converter, multi resonance converter and series resonance and parallel resonance converters, basic test of SMPS with PWM control circuit, Buck converter, Boost converter, flyback converter, forward converter and IC for control circuit.
Modeling of Maximum Power Point Tracking Controller for Solar Power System
Directory of Open Access Journals (Sweden)
Aryuanto Soetedjo
2012-09-01
Full Text Available In this paper, a Maximum Power Point Tracking (MPPT controller for solar power system is modeled using MATLAB Simulink. The model consists of PV module, buck converter, and MPPT controller. The contribution of the work is in the modeling of buck converter that allowing the input voltage of the converter, i.e. output voltage of PV is changed by varying the duty cycle, so that the maximum power point could be tracked when the environmental changes. The simulation results show that the developed model performs well in tracking the maximum power point (MPP of the PV module using Perturb and Observe (P&O Algorithm.
Analysis of current-bidirectional buck-boost based switch-mode audio amplifier
DEFF Research Database (Denmark)
Bolten Maizonave, Gert; Andersen, Michael A. E.; Kjærgaard, Claus
2011-01-01
The following studdy was carried out in order to assses quantitatively the performannce of the buck--boost converter whhen used as swiitch-mode audio amplifier. It comprises of, to beggin with, the de limitation of design criteria bassed on the state of-the-art solution, which is based...... in a differential mode buckbased amplifier with a boost converter as power supply. The averaged switch modelling of the differential mode current bidirectional topology is also used, in order to analyze the steady state and frequency-wise behaviour of this converter and parameterize it to meet the design criteria....... Next, several piecewise-linear siimulation resultss are shown with detail enough to emphasize the features of the converter. A simple prototype is implemented to verify the main predicted features. Presently no previous publicat ion could be found containing a thorough analysis of this topology...
DEFF Research Database (Denmark)
Pelan, Ovidiu; Cornea, Octavian; Muntean, Nicolae
2014-01-01
This paper presents and discusses design considerations and efficiency investigation of a conventional step-down and a hybrid switched-capacitor DC-DC converter. Three MOSFETs with low on-resistance have been tested for each converter in order to find the most adequate switch for this application....... The experimental results and comparative efficiency graphs were obtained with a 1kW laboratory prototype dedicated for a 42/14V dual voltage automotive system....
Pulse width modulated buck-boost five-level current source inverters
DEFF Research Database (Denmark)
Blaabjerg, Frede; Gao, F.; Loh, P.C.
2008-01-01
, resulting in the natural balance of input current. For maintaining the normalized volt-sec average unchanged, the alternative phase opposition disposition (APOD) modulation scheme with typical gating signal mapping technique from voltage source inverter (VSI) to CSI can be assumed to control the five......This paper presents new five-level current source inverters (CSIs) with voltage/current buck-boost capability. Being different from the existing multilevel CSI, the proposed CSIs were first designed to regulate the flowing path of dc input current by controlling two additional active switches......-level buck-boost CSIs. Next by observing the hidden current charging path during inductive charging interval under APOD modulation, it is noted that the buck-boost five-level CSI can then be further modified with lesser active component without degrading output performance. To verify the theoretical findings...
Directory of Open Access Journals (Sweden)
Abouchabana Nabil
2017-01-01
Full Text Available Photovoltaic generators (PVG produce a variable power according to the solar radiation (G and temperature (T. This variation affects the sizing of the components of DC / DC converters, powered by such PVG, and make it difficult. The effects may differ from one component to another. The main and critical one is presented by the inductor, the element that stores the energy during sampled periods. We propose in this work an auto-adaptation of these inductor values to maintain optimal performance of the power yield of these converters. Our idea is to replace the inductor by a coupled inductor where this adjustment is made by the addition of an adjustable electric field in the magnetic core. Low current intensities come from the PVG supply the second inductor of the coupled inductor through a circuit controlled by a fuzzy controller (FC. The whole system is modeled and simulated under MATLAB/SIMULINK for the control part of the system and under PSPICE for the power part of the system. The obtained results show good performances of the proposed converter over the standard one.
Abouchabana, Nabil; Haddadi, Mourad; Rabhi, Abdelhamid; El Hajjaji, Ahmed
2017-11-01
Photovoltaic generators (PVG) produce a variable power according to the solar radiation (G) and temperature (T). This variation affects the sizing of the components of DC / DC converters, powered by such PVG, and make it difficult. The effects may differ from one component to another. The main and critical one is presented by the inductor, the element that stores the energy during sampled periods. We propose in this work an auto-adaptation of these inductor values to maintain optimal performance of the power yield of these converters. Our idea is to replace the inductor by a coupled inductor where this adjustment is made by the addition of an adjustable electric field in the magnetic core. Low current intensities come from the PVG supply the second inductor of the coupled inductor through a circuit controlled by a fuzzy controller (FC). The whole system is modeled and simulated under MATLAB/SIMULINK for the control part of the system and under PSPICE for the power part of the system. The obtained results show good performances of the proposed converter over the standard one.
State-plane analysis of parallel resonant converter
Oruganti, R.; Lee, F. C.
1985-01-01
A method for analyzing the complex operation of a parallel resonant converter is developed, utilizing graphical state-plane techniques. The comprehensive mode analysis uncovers, for the first time, the presence of other complex modes besides the continuous conduction mode and the discontinuous conduction mode and determines their theoretical boundaries. Based on the insight gained from the analysis, a novel, high-frequency resonant buck converter is proposed. The voltage conversion ratio of the new converter is almost independent of load.
Optimal tree-stem bucking of northeastern species of China
Jingxin Wang; Chris B. LeDoux; Joseph McNeel
2004-01-01
An application of optimal tree-stem bucking to the northeastern tree species of China is reported. The bucking procedures used in this region are summarized, which are the basic guidelines for the optimal bucking design. The directed graph approach was adopted to generate the bucking patterns by using the network analysis labeling algorithm. A computer-based bucking...
Diode-Assisted Buck-Boost Voltage-Source Inverters
DEFF Research Database (Denmark)
Gao, Feng; Loh, Poh Chiang; Teodorescu, Remus
2009-01-01
, a number of diode-assisted inverter variants can be designed with each having its own operational principle and voltage gain expression. For controlling them, a generic modulation scheme that can be used for controlling all diode-assisted variants with minimized harmonic distortion and component stress......This paper proposes a number of diode-assisted buck-boost voltage-source inverters with a unique X-shaped diode-capacitor network inserted between the inverter circuitry and dc source for producing a voltage gain that is comparatively higher than those of other buck-boost conversion techniques....... Using the diode-assisted network, the proposed inverters can naturally configure themselves to perform capacitive charging in parallel and discharging in series to give a higher voltage multiplication factor without compromising waveform quality. In addition, by adopting different front-end circuitries...
Grid Connected WECS with A Five Level DCMLI using PID Controller
Directory of Open Access Journals (Sweden)
G.Balaji
2014-07-01
Full Text Available This paper deals with the analysis, modeling and control system for permanent magnet synchronous generator (PMSG based wind turbine connected to the grid. A wind energy conversion using DC-DC Buck- Boost Converter for permanent magnet synchronous generator (PMSG based variable speed wind energy conversion system (WECS has been proposed which is integrated with grid using five-level diode clamped multilevel (DCMLI inverter. In this work the instantaneous values of input side current and voltage of DC-DC buck-boost converter are utilized for implementing the PID controller. The proposed work is verified by the simulation in Powersim.
Topological Design and Modulation Strategy for Buck-Boost Three-Level Inverters
DEFF Research Database (Denmark)
Gao, Feng; Loh, Poh Chiang; Teodorescu, Remus
2009-01-01
To date, designed topologies for dc-ac inversion with both voltage buck and boost capabilities are mainly focused on two-level circuitries with extensions to three-level possibilities left nearly unexplored. Contributing to this area of research, this paper presents the design of a number of viable...... can perform distinct five-level line voltage and three-level phase voltage switching by simply controlling the active switches located in the designed voltage boost section of the circuits. As a cost saving option, one active switch can further be removed from the voltage boost section of the circuits...... buck-boost threelevel inverters that can also support bidirectional power conversion. The proposed front-end circuitry is developed from the C´ ukderived buck-boost two-level inverter, and by using the "alternative phase opposition disposition" modulation scheme, the buck-boost three-level inverters...
multilevel buck converter for automotive electrical load
African Journals Online (AJOL)
... from internal combustion engine (ICE). The mass production of the hybrid electric (HE) and the electric vehicle (EV) is still awaited due to subsystem inefficiencies. Increasing the efficiencies of the power converters within subsystems of these HEVs and EVs will increase the performance of the new transportation vehicles.
Performance evaluation of a DC-AC inverter controlled with ZAD-FPIC
Directory of Open Access Journals (Sweden)
Fredy Edimer Hoyos Velasco
2018-01-01
Full Text Available Introduction: Power converters are used in microgrids to transfer power to the load with a regulated voltage. However, the DC-AC converters present distortions in the waveform that can be improved with the help of real-time controllers. Objective: Evaluate the response in alternating current of the buck converter controlled using ZAD-FPIC technique. Methodology: Based on the differential equations that describe the buck power converter, the ZAD and FPIC controllers are designed, simulations of the complete controlled system are made in Simulink of MATLAB, the system is implemented experimentally, and the controller is executed in real-time with the help of a DS1104 from dSPACE. In the end, several tests are carried out to check the effectiveness of the controller. Results: The results show that the controller allows good stability against different variations in the system and in the load. Conclusions: The ZAD-FPIC technique controls the variable and tracks changes in the waveform, magnitude, and frequency of the reference signal. The controller presents good stability to different tests, tracking the reference signal after each event.
Bidirectional DC-DC converter fed drive for electric vehicle system
African Journals Online (AJOL)
ATHARVA
of converters can be connected in series or parallel with low switching frequency (Yu and Lai, 2008). ... reversed, the topology functions as a buck converter through the modulation of Q1 , with the .... The state space average model is shown in (9) and (10). │. ⌋. ⌉ .... terms of high energy density, compact size and reliability.
EFFECT OF MUCUNA (Mucuna pruriens ON SPERMIOGRAMS OF WEST AFRICAN DWARF BUCKS
Directory of Open Access Journals (Sweden)
James Olamitibo Daramola
2015-08-01
Full Text Available The study was carried out to investigate the potential effect of Mucuna pruriens seed powder on spermiograms of West African Dwarf bucks (WAD. Twenty bucks were randomly assigned to five treatments consisting of four animals each receiving 0, 25, 50, 75, 100mg/Bw of Mucuna pruriens seed powder administered via oral route for 30 days consecutively. Following treatment, spermiograms of the animals were determined. The results showed that exposure of bucks to Mucuna pruriens powder led to a significant increase in weight gain, scrotal width, scrotal circumference, testicular weight, gonadosomatic index, sperm motility and testicular parenchyma of animals compared to the control and the improvement in these parameters was much pronounced in bucks that received 75mg Mucuna pruriens seed powder (P<0.05. Higher (P<0.05 sperm concentration was observed in 100mg inclusion of Mucuna pruriens seed powder compared to other treatments. The results showed a decline (P<0.05 in the level of testosterone with increasing level of Mucuna pruriens seed powder administration. The findings showed that oral administration of Mucuna pruriens seed powder to the bucks for 30 days resulted in improved testicular measurements and sperm quality without any adverse effect on structure of reproductive physiology of the bucks.
High performance current controller for particle accelerator magnets supply
DEFF Research Database (Denmark)
Maheshwari, Ram Krishan; Bidoggia, Benoit; Munk-Nielsen, Stig
2013-01-01
The electromagnets in modern particle accelerators require high performance power supply whose output is required to track the current reference with a very high accuracy (down to 50 ppm). This demands very high bandwidth controller design. A converter based on buck converter topology is used...
Modeling and analysis of fractional order DC-DC converter.
Radwan, Ahmed G; Emira, Ahmed A; AbdelAty, Amr M; Azar, Ahmad Taher
2017-07-11
Due to the non-idealities of commercial inductors, the demand for a better model that accurately describe their dynamic response is elevated. So, the fractional order models of Buck, Boost and Buck-Boost DC-DC converters are presented in this paper. The detailed analysis is made for the two most common modes of converter operation: Continuous Conduction Mode (CCM) and Discontinuous Conduction Mode (DCM). Closed form time domain expressions are derived for inductor currents, voltage gain, average current, conduction time and power efficiency where the effect of the fractional order inductor is found to be strongly present. For example, the peak inductor current at steady state increases with decreasing the inductor order. Advanced Design Systems (ADS) circuit simulations are used to verify the derived formulas, where the fractional order inductor is simulated using Valsa Constant Phase Element (CPE) approximation and Generalized Impedance Converter (GIC). Different simulation results are introduced with good matching to the theoretical formulas for the three DC-DC converter topologies under different fractional orders. A comprehensive comparison with the recently published literature is presented to show the advantages and disadvantages of each approach. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.
Switched-mode converters (one quadrant)
Barrade, P
2006-01-01
Switched-mode converters are DC/DC converters that supply DC loads with a regulated output voltage, and protection against overcurrents and short circuits. These converters are generally fed from an AC network via a transformer and a conventional diode rectifier. Switched-mode converters (one quadrant) are non-reversible converters that allow the feeding of a DC load with unipolar voltage and current. The switched-mode converters presented in this contribution are classified into two families. The first is dedicated to the basic topologies of DC/DC converters, generally used for low- to mid-power applications. As such structures enable only hard commutation processes, the main drawback of such topologies is high commutation losses. A typical multichannel evolution is presented that allows an interesting decrease in these losses. Deduced from this direct DC/DC converter, an evolution is also presented that allows the integration of a transformer into the buck and the buck–boost structure. This enables an int...
Directory of Open Access Journals (Sweden)
R. Silva-Ortigoza
2014-01-01
Full Text Available Sliding mode control is a discontinuous control technique that is, by its nature, appropriate for controlling variable structure systems, such as the switch regulated systems employed in power electronics. However, when designing control laws based on the average models of these systems a modulator is necessary for their experimental implementation. Among the most widely used modulators in power electronics are the pulse width modulation (PWM and, more recently, the sigma-delta-modulator (Σ-Δ-modulator. Based on the importance of achieving an appropriate implementation of average control laws and the relevance of the trajectory tracking task in DC/DC power converters, for the first time, this research presents the assessment of the experimental results obtained when one of these controllers is implemented through either a PWM or a Σ-Δ-modulator to perform such a task. A comparative assessment based on the integral square error (ISE index shows that, at frequencies with similar efficiency, the Σ-Δ-modulator provides a better tracking performance for the DC/DC Buck converter. In this paper, an average control based on differential flatness was used to perform the experiments. It is worth mentioning that a different trajectory tracking controller could have been selected for this research.
Geologic Controls of Sand Boil Formation at Buck Chute, Mississippi
2017-06-30
26 5.1 Electrical resistivity tomography ...construction at Buck Chute in preparation to the 2011 Flood. ERDC/GSL TR-17-12 21 4 Methods 4.1 Electrical resistivity tomography The resistivity ...could contribute to sand boil formation is missed. Electrical Resistivity Tomography (ERT) is a subsurface investigation method that combines the
A Feedback Passivation Design for DC Microgrid and Its DC/DC Converters
Directory of Open Access Journals (Sweden)
Feifan Ji
2016-12-01
Full Text Available There are difficulties in analyzing the stability of microgrids since they are located on various network structures. However, considering that the network often consists of passive elements, the passivity theory is applied in this paper to solve the above-mentioned problem. It has been formerly shown that when the network is weakly strictly positive real (WSPR, the DC microgrid is stable if all interfaces between the microgrid and converters are made to be passive, which is called interface passivity. Then, the feedback passivation method is proposed for the controller design of various DC–DC converters to achieve the interface passivity. The interface passivity is different from the passivity of closed-loop systems on which the passivity based control (PBC concentrates. The feedback passivation design is detailed for typical buck converters and boost converters in terms of conditions that the controller parameters should satisfy. The theoretical results are verified by a hardware-in-loop real-time labotray (RTLab simulation of a DC microgrid with four generators.
Radiation tolerant power converter controls
Todd, B; King, Q; Uznanski, S
2012-01-01
The Large Hadron Collider (LHC) at the European Organisation for Nuclear Research (CERN) is the world's most powerful particle collider. The LHC has several thousand magnets, both warm and super-conducting, which are supplied with current by power converters. Each converter is controlled by a purpose-built electronic module called a Function Generator Controller (FGC). The FGC allows remote control of the power converter and forms the central part of a closed-loop control system where the power converter voltage is set, based on the converter output current and magnet-circuit characteristics. Some power converters and FGCs are located in areas which are exposed to beam-induced radiation. There are numerous radiation induced effects, some of which lead to a loss of control of the power converter, having a direct impact upon the accelerator's availability. Following the first long shut down (LS1), the LHC will be able to run with higher intensity beams and higher beam energy. This is expected to lead to signifi...
User's design handbook for a Standardized Control Module (SCM) for DC to DC Converters, volume 2
Lee, F. C.
1980-01-01
A unified design procedure is presented for selecting the key SCM control parameters for an arbitrarily given power stage configuration and parameter values, such that all regulator performance specifications can be met and optimized concurrently in a single design attempt. All key results and performance indices, for buck, boost, and buck/boost switching regulators which are relevant to SCM design considerations are included to facilitate frequent references.
How stem defects affect the capability of optimum bucking method?
Directory of Open Access Journals (Sweden)
Abdullah Emin Akay
2015-07-01
Full Text Available In forest harvesting activities, computer-assisted optimum bucking method increases the economic value of harvested trees. The bucking decision highly depends on the log quality grades which mainly vary with the surface characteristics such as stem defects and form of the stems. In this study, the effects of stem defects on optimum bucking method was investigated by comparing bucking applications which were conducted during the logging operations in two different Brutian Pine (Pinus brutia Ten stands. In the applications, the first stand contained the stems with relatively more stem defects than that of the stems in the second stand. The average number of defects per log for sample trees in the first and the second stand was recorded as 3.64 and 2.70, respectively. The results indicated that optimum bucking method increased the average economic value of harvested trees by 15.45% and 8.26 % in the stands, respectively. Therefore, the computer-assisted optimum bucking method potentially provides better results than that of traditional bucking method especially for the harvested trees with more stem defects.
Adaptive slope compensation for high bandwidth digital current mode controller
DEFF Research Database (Denmark)
Taeed, Fazel; Nymand, Morten
2015-01-01
An adaptive slope compensation method for digital current mode control of dc-dc converters is proposed in this paper. The compensation slope is used for stabilizing the inner current loop in peak current mode control. In this method, the compensation slope is adapted with the variations...... in converter duty cycle. The adaptive slope compensation provides optimum controller operation in term of bandwidth over wide range of operating points. In this paper operation principle of the controller is discussed. The proposed controller is implemented in an FPGA to control a 100 W buck converter...
Directory of Open Access Journals (Sweden)
Eka Prasetyono
2015-09-01
Full Text Available Bidirectional DC-DC converter is needed in the energy storage system. The converter topology used in this paper was a non-isolated bidirectional DC-DC buck-boost converter. This converter worked in two ways, which the charging mode stored energy into battery when load current was less than nominal main DC current (set point and discharging mode transferred energy from battery to the load when its current exceeded set point value. Both of these modes worked automatically according to the load current. The charging and discharging currents were controlled by fuzzy logic controller which was implemented on microcontroller ARM Cortex-M4F STM32F407VG. This paper compares two types of fuzzy membership function (triangular and sigmoid in controlling bidirectional DC-DC converter. The results showed that fuzzy logic controller with triangle membership function and sigmoid as control bidirectional DC-DC converter had no significant different response, both had an average error for charging and discharging process under 4% with ripple current on the main DC bus around 0.5%. The computing time of program for fuzzy logic controller with triangular membership functions had 19.01% faster than sigmoid, and fuzzy logic computation time on a microcontroller with hardware floating point was 60% faster than software floating point.
Investigation and improvement of high step- up converters for pv module applications
Directory of Open Access Journals (Sweden)
Hamed moradmand jazi
2017-01-01
Full Text Available sun is of the clean and cheapest sources of energy. Charging slight energy to electricity is carried out by PV modules. Since most electric consumers need Ac input voltage, the PV modules output voltage should be changed into Ac form. But, the voltage level of PV modules is much lower than the voltage needed in input stage of inverters. Because of large voltage level. Difference it is not possible to use the basic boost and buck-boost converters. The basic boost and buck-boost converters definitely can not be used in this applications, for, they will face extreme drop in efficiency in duty cycles closer to unity. In this paper The proposed converter is presented in order to decrease the voltage stress of coupled inductors based high step-up converters. The voltage stress in the proposed converter is lower than the high step-up boost converter with coupled inductors in identical condition. Also, soft switching condition for switches and diodes is realized by active clamp circuit, and with this technique and proper selection of duty cycle, large gain and high efficiency could be achieved ultimately. . In this paper theoretical analysis is used for analyzing the performance of the proposed converters, and in order to verify the theoretical analysis, simulated results from pspice software is provides.
Directory of Open Access Journals (Sweden)
Muhamad Zalani Daud
2014-01-01
Full Text Available This paper presents an evaluation of an optimal DC bus voltage regulation strategy for grid-connected photovoltaic (PV system with battery energy storage (BES. The BES is connected to the PV system DC bus using a DC/DC buck-boost converter. The converter facilitates the BES power charge/discharge to compensate for the DC bus voltage deviation during severe disturbance conditions. In this way, the regulation of DC bus voltage of the PV/BES system can be enhanced as compared to the conventional regulation that is solely based on the voltage-sourced converter (VSC. For the grid side VSC (G-VSC, two control methods, namely, the voltage-mode and current-mode controls, are applied. For control parameter optimization, the simplex optimization technique is applied for the G-VSC voltage- and current-mode controls, including the BES DC/DC buck-boost converter controllers. A new set of optimized parameters are obtained for each of the power converters for comparison purposes. The PSCAD/EMTDC-based simulation case studies are presented to evaluate the performance of the proposed optimized control scheme in comparison to the conventional methods.
Daud, Muhamad Zalani; Mohamed, Azah; Hannan, M A
2014-01-01
This paper presents an evaluation of an optimal DC bus voltage regulation strategy for grid-connected photovoltaic (PV) system with battery energy storage (BES). The BES is connected to the PV system DC bus using a DC/DC buck-boost converter. The converter facilitates the BES power charge/discharge to compensate for the DC bus voltage deviation during severe disturbance conditions. In this way, the regulation of DC bus voltage of the PV/BES system can be enhanced as compared to the conventional regulation that is solely based on the voltage-sourced converter (VSC). For the grid side VSC (G-VSC), two control methods, namely, the voltage-mode and current-mode controls, are applied. For control parameter optimization, the simplex optimization technique is applied for the G-VSC voltage- and current-mode controls, including the BES DC/DC buck-boost converter controllers. A new set of optimized parameters are obtained for each of the power converters for comparison purposes. The PSCAD/EMTDC-based simulation case studies are presented to evaluate the performance of the proposed optimized control scheme in comparison to the conventional methods.
High-frequency high-voltage high-power DC-to-DC converters
Wilson, T. G.; Owen, H. A.; Wilson, P. M.
1982-09-01
A simple analysis of the current and voltage waveshapes associated with the power transistor and the power diode in an example current-or-voltage step-up (buck-boost) converter is presented. The purpose of the analysis is to provide an overview of the problems and design trade-offs which must be addressed as high-power high-voltage converters are operated at switching frequencies in the range of 100 kHz and beyond. Although the analysis focuses on the current-or-voltage step-up converter as the vehicle for discussion, the basic principles presented are applicable to other converter topologies as well.
Primary Paralleled Isolated Boost Converter with Extended Operating Voltage Range
DEFF Research Database (Denmark)
Hernandez Botella, Juan Carlos; Sen, Gökhan; Mira Albert, Maria del Carmen
2012-01-01
Applications requiring wide input and output voltage range cannot often be satisfied by using buck or boost derived topologies. Primary paralleled isolated boost converter (PPIBC) [1]-[2] is a high efficiency boost derived topology. This paper proposes a new operation mode for extending the input...
Implementation of a PV lighting system based on DC-DC converter with intelligent controlled approach
Energy Technology Data Exchange (ETDEWEB)
Hua, C.-C.; Chuang, D.-J. [National Yunlin Univ. of Science and Technology, Douliou, Yunlin, Taiwan (China). Dept. of Electrical Engineering; Chuang, C.-W. [National Yunlin Univ. of Science and Technology, Douliou, Yunlin, Taiwan (China). Graduate School of Engineering Science and Technology
2007-07-01
Photovoltaic (PV) lighting systems for municipalities represent one of the largest cost effective markets for PVs. The installation cost of just one or two utility power poles can justify the initial cost of a PV lighting system. However, many previous PV lighting systems have experienced a number of component failures including premature charge controller, battery, and ballast illumination failures. This paper presented the design and implementation of a digital high performance photovoltaic lighting system based on a microcontroller. A high brightness light-emitting diode (HBLED), was used as it can work at very high efficiency with a specially designed lighting power module. The proposed system consisted of a photovoltaic module, a light emitting diode (LED) lighting module, a bi-directional buck-boost converter and a battery. The paper analysed battery charging methods and proposed a control strategy and hardware implementation. The dimming control methods for LED were also discussed and compared. The experimental results were also provided to verify the theoretical analysis and design procedure of a digital controlled photovoltaic lighting system. It was concluded that the experimental results verified the performance of the proposed photovoltaic lighting system. 8 refs., 1 tab., 18 figs.
Escobar, Gerardo; van der Schaft, Arjan; Ortega, Romeo
1999-01-01
In this paper we show how, using the Hamiltonian formalism, we can systematically derive mathematical models that describe the behaviour of a large class of switching power converters, including the “Boost”, “Buck”, “Buck-Boost”, “ uk” and “Flyback” converters. We follow the approach proposed by van
Reduction in electromagnetic interference of switching converters using self-excitation-chaos
DEFF Research Database (Denmark)
Li, Qingnan; Xiong, Rui; He, Ou
2008-01-01
operating in chaos, the simulation results demonstrate that a reduction of spectral peak and consequent spreading of the spectrum can be shown, any desirable amount of reduction and consequent spreading of the spectrum can be obtained simply by varying the control parameter of the circuit and a optimization......We derived a second-order S-switching iterative map describing the dynamics of simple feedback Buck switching regulator operating in continuous mode. Analysis of this map shows that chaos and bifurcations may occur along with the changing of values of some system parameters. By making the converter...
A three-port direct current converter
DEFF Research Database (Denmark)
2016-01-01
circuit comprises a connection between the at least one input direct current source and the at least one storage battery, the primary side circuit configured for operating as a buck converter; a second magnetic component serially coupled to the first single magnetic component, wherein the first and second...... magnetic components are configured to perform a voltage step-up, wherein the secondary side circuit comprises a connection between the at least one storage battery and at least one load, the secondary side configured for operating as a tapped boost converter; wherein the three-port direct current converter......The three-port direct current converter comprising: at least one input direct current source; at least one storage battery; a primary side circuit; a secondary side circuit; a first single magnetic component shared by the primary side circuit and the secondary side circuit, wherein the primary side...
High-Voltage DC-DC Converter Topology for PV Energy Utilization - Investigation and Implementation
DEFF Research Database (Denmark)
Sanjeevikumar, Padmanaban; Blaabjerg, Frede; Wheeler, Patrick
2017-01-01
This paper exploited the utilization of photovoltaic (PV) energy system with high-voltage (HV) output DC-DC converter. Classical boost converters are used for both renewable energy integration and HV applications, but limited by reducing output/efficiency in performance. Moreover, as parasitic...... elements suppress the power transfer ratio, converter needs to maximize the PV energy utilization. This investigation study focused to include additional parasitic elements (voltage-lift technique) to a standard DC-DC buck converter and to overcome all the above drawbacks to maximize the PV power...
Growth Performance of Red Sokoto Bucks Fed Inclusion levels of ...
African Journals Online (AJOL)
This study was carried out to evaluate the growth performance of red Sokoto bucks fed two (2) inclusion levels of rawwater soaked and lime soaked Hibiscus sabdariffa seeds in rice offal based diets. A total of twenty one (21) red Sokoto bucks were randomly allotted into seven treatments with three (3) bucks per group while ...
Simple DCM or CRM analog peak current controller for HV capacitor charge-discharge applications
DEFF Research Database (Denmark)
Trintis, Ionut; Dimopoulos, Emmanouil; Munk-Nielsen, Stig
2013-01-01
This paper presents a simple analog current controller suitable for buck and boost converter topologies. The controller operates in DCM or CRM, depending on the setup. The experimental results are presented to validate the proposed controller functionality for a high voltage capacitor charge...
Analysis and design of a standardized control module for switching regulators
Lee, F. C.; Mahmoud, M. F.; Yu, Y.; Kolecki, J. C.
1982-07-01
Three basic switching regulators: buck, boost, and buck/boost, employing a multiloop standardized control module (SCM) were characterized by a common small signal block diagram. Employing the unified model, regulator performances such as stability, audiosusceptibility, output impedance, and step load transient are analyzed and key performance indexes are expressed in simple analytical forms. More importantly, the performance characteristics of all three regulators are shown to enjoy common properties due to the unique SCM control scheme which nullifies the positive zero and provides adaptive compensation to the moving poles of the boost and buck/boost converters. This allows a simple unified design procedure to be devised for selecting the key SCM control parameters for an arbitrarily given power stage configuration and parameter values, such that all regulator performance specifications can be met and optimized concurrently in a single design attempt.
Energy Technology Data Exchange (ETDEWEB)
Lee, H. [Kyungnam University (Korea, Republic of)
1996-10-27
A soft switching method with small switching loss was proposed for the purpose of increasing the efficiency of a DC-DC boost converter which converted a DC current generated by solar cells to a variable DC current. Existing current converters are supplemented by using a snubber circuit around the switch so as to protect the switch by a hard switching action. However, with an increase of the output current, snubber loss is increased, reducing the efficiency. In order to solve this problem, the partial resonant switch method was applied to the converter; with this method of partially forming a resonant circuit only at the time of turning on/off of the switch, the switching loss was reduced through the soft switching, thereby making the proposed converter operate with high efficiency. Moreover, the resonant element of the partial resonant circuit using a snubber condenser, the energy accumulated in the condenser was regenerated on the power supply side without loss of snubber. With the regenerated energy, the proposed converter was provided with a smaller ratio of switching to use than the conventional converter. 4 refs., 7 figs., 1 tab.
Prasetiyo, Ryan; Maulana, Dwindra Wilham; Panatarani, Camellia; Joni, I Made
2016-01-01
In order to have a DC-DC buck boost converter with performances as desired specifications, the design process was performed by developing a model and simulation. The purpose of this research was to design a converter applied for a MINI 3 plus Wind Turbine. The converter topology was designed with Single Ended Primary Inductor Converter (SEPIC) using a Continuous Conduction Mode (CCM). The output specifications of converter are input voltage 60 V, input current 7,5 A, output voltage 25 V...
Directory of Open Access Journals (Sweden)
Zanxiang Nie
2017-01-01
Full Text Available Linear wave energy converters generate intrinsically intermittent power with variable frequency and amplitude. A composite energy storage system consisting of batteries and super capacitors has been developed and controlled by buck-boost converters. The purpose of the composite energy storage system is to handle the fluctuations and intermittent characteristics of the renewable source, and hence provide a steady output power. Linear wave energy converters working in conjunction with a system composed of various energy storage devices, is considered as a microsystem, which can function in a stand-alone or a grid connected mode. Simulation results have shown that by applying a boost H-bridge and a composite energy storage system more power could be extracted from linear wave energy converters. Simulation results have shown that the super capacitors charge and discharge often to handle the frequent power fluctuations, and the batteries charge and discharge slowly for handling the intermittent power of wave energy converters. Hardware systems have been constructed to control the linear wave energy converter and the composite energy storage system. The performance of the composite energy storage system has been verified in experiments by using electronics-based wave energy emulators.
Ram and Buck Breeding Soundness Examination
Directory of Open Access Journals (Sweden)
Ahmed TIBARY
2018-06-01
Full Text Available Male breeding soundness examination (BSE is an important component of sheep and goat farming. BSE is best performed 2 months before the breeding season and is based on clinical and physical examination as well as sperm abnormalities detection. Rams are classified based on physical examination and semen evaluation finding in one of 4 categories: Unsatisfactory, questionable, satisfactory, and excellent. The satisfactory rams will achieve good reproductive performance if joined to ewes at a ratio of 1:50 for 60 days. However exceptional rams are expected to achieve good reproductive performance at a ratio of 1 ram to 100 ewes. For Buck, scrotal circumference should be at least 25 cm for breeds weighing more than 40 kg. Buck is deemed satisfactory breeder if he passes the physical examination, and has an ejaculate with at least 50% progressively motile spermatozoa and less than 30% total sperm abnormalities. This paper reviews factors affecting fertility, sperm production and quality as well as libido and mating ability in the ram. Details of genital examination and semen evaluation and interpretation of results are discussed. Classification of rams according to their reproductive potential is presented. Specific recommendations, when available for the buck, are highlighted. The main genital diseases are presented. The most frequent culling reason for ram is epididymitis due to Brucella ovis. Systematic culling of rams with epididymitis improves flock lambing rates by 10 to 15%. Overall, the examination of the reproductive capacity in the ram and the buck is an important tool for improvement of flocks/herds fertility and prevention of contagious or hereditary diseases.
Modeling and reliability analysis of three phase z-source AC-AC converter
Directory of Open Access Journals (Sweden)
Prasad Hanuman
2017-12-01
Full Text Available This paper presents the small signal modeling using the state space averaging technique and reliability analysis of a three-phase z-source ac-ac converter. By controlling the shoot-through duty ratio, it can operate in buck-boost mode and maintain desired output voltage during voltage sag and surge condition. It has faster dynamic response and higher efficiency as compared to the traditional voltage regulator. Small signal analysis derives different control transfer functions and this leads to design a suitable controller for a closed loop system during supply voltage variation. The closed loop system of the converter with a PID controller eliminates the transients in output voltage and provides steady state regulated output. The proposed model designed in the RT-LAB and executed in a field programming gate array (FPGA-based real-time digital simulator at a fixedtime step of 10 μs and a constant switching frequency of 10 kHz. The simulator was developed using very high speed integrated circuit hardware description language (VHDL, making it versatile and moveable. Hardware-in-the-loop (HIL simulation results are presented to justify the MATLAB simulation results during supply voltage variation of the three phase z-source ac-ac converter. The reliability analysis has been applied to the converter to find out the failure rate of its different components.
Physiological response of rabbit bucks to prolonged feeding of ...
African Journals Online (AJOL)
Sixty-four (64) weanling rabbit bucks, 5 to 6 weeks old, were involved in a 2 x 4 factorial experiment to evaluate the effects of prolonged feeding of cottonseed cake (CSC) – based diets with or without vitamin E supplementation on the physiological response of the bucks. There were eight treatment combinations comprising ...
Three Phase Six-Switch PWM Buck Rectifier with Power Factor Improvement
DEFF Research Database (Denmark)
Zafar Ullah Khan, M; Mohsin Naveed, M.; Hussain, Dil Muhammad Akbar
2013-01-01
Conventional Phase Controlled Rectifier injects low order current harmonics into the AC mains. Large size filtering components are required to attenuate these harmonics. In this paper, Three Phase Six-Switch PWM Buck Rectifier[1] is presented which operates at nearly unity power factor and provides...
Directory of Open Access Journals (Sweden)
Abdelhak Bouchakour
2017-06-01
Full Text Available This study investigates the performance of three different photovoltaic (PV water pumping systems driven by three types of motors, namely a separately excited DC motor (DCM, an asynchronous motor (ASM, and a permanent magnet synchronous motor (PMSM, via a DC/DC buck-boost converter coupled to a centrifugal pump. The purpose of this study is to implement a fast and robust control for this type of a nonlinear system, controlled by sliding mode (SM. This paper presents an SM control technique for controlling a DC/DC buck-boost converter to transfer the maximum power delivered by the PV generator. Each component is studied and analyzed to simulate the global system in MATLAB/SIMULINK. The three systems are then compared to determine the overall effectiveness of the proposed command. The study concludes that the ASM-driven PV system yields highly favorable results and requires less maintenance compared with other systems.
Energy Technology Data Exchange (ETDEWEB)
Enrique, J.M.; Duran, E.; Andujar, J.M. [Departamento de Ingenieria Electronica, de Sistemas Informaticos y Automatica, Universidad de Huelva (Spain); Sidrach-de-Cardona, M. [Departamento de Fisica Aplicada, II, Universidad de Malaga (Spain)
2007-01-15
The operating point of a photovoltaic generator that is connected to a load is determined by the intersection point of its characteristic curves. In general, this point is not the same as the generator's maximum power point. This difference means losses in the system performance. DC/DC converters together with maximum power point tracking systems (MPPT) are used to avoid these losses. Different algorithms have been proposed for maximum power point tracking. Nevertheless, the choice of the configuration of the right converter has not been studied so widely, although this choice, as demonstrated in this work, has an important influence in the optimum performance of the photovoltaic system. In this article, we conduct a study of the three basic topologies of DC/DC converters with resistive load connected to photovoltaic modules. This article demonstrates that there is a limitation in the system's performance according to the type of converter used. Two fundamental conclusions are derived from this study: (1) the buck-boost DC/DC converter topology is the only one which allows the follow-up of the PV module maximum power point regardless of temperature, irradiance and connected load and (2) the connection of a buck-boost DC/DC converter in a photovoltaic facility to the panel output could be a good practice to improve performance. (author)
Testicular Morphometry and Sperm Quality of Rabbit Bucks Fed ...
African Journals Online (AJOL)
Twenty rabbit bucks of mixed breeds, aged four to five weeks which weighed between 627.4g to 631.5g were used to evaluate the effect of Moringa oleifera leaf meal (MOLM) on testicular morphometry and sperm quality. Five bucks were randomly assigned to each of the four diets containing MOLM at 0%. 5%, 10% and ...
Practical Design Guidelines of qZSI Based Step-Up DC/DC Converter
Zakis, Janis; Vinnikov, Dmitri; Roasto, Indrek; Jalakas, Tanel
2010-01-01
This paper presents some design guidelines for a new voltage fed step-up DC/DC isolated converter. The most significant advantage of proposed converter is voltage buck-boost operation on single stage. The most promising application for proposed converter is in the field of distributed power generation e.g. fuel cells or photovoltaic. The most sensitive issues - such as power losses caused by high currents in the input side of converter and high transient overvoltages across the inverter bridge caused by stray inductances were discussed and solved. The proposals and recommendations to overcome these issues are given in the paper. The Selection and design guidelines of converter elements are proposed and explained. The prototype of proposed converter was built and experimentally tested. Some results are presented and evaluated.
A Comparative Study of Analog Voltage-mode Control Methods for Ultra-Fast Tracking Power Supplies
DEFF Research Database (Denmark)
Høyerby, Mikkel Christian Wendelboe; Andersen, Michael Andreas E.
2007-01-01
This paper presents a theoretical and experimental comparison of the standard PWM/PID voltage-mode control method for single-phase buck converters with two highperformance self-oscillating (a.k.a. sliding mode) control methods. The application considered is ultra-fast tracking power supplies...... (UFTPSs) for RF power amplifiers, where the switching converter needs to track a varying reference voltage precisely and quickly while maintaining low output impedance. The small-signal analyses performed on the different controllers show that the hysteretic-type controller can achieve the highest loop...
Applying Buck Converter in Jiuquan Solar Photovoltaic Power Generation%Buck变换器在酒泉太阳能光伏发电中的应用
Institute of Scientific and Technical Information of China (English)
秦天像
2011-01-01
Solar photovoltaic effect, the output voltage is energy, as a new, easily subject not stable. The research presented to seasonal variation, diurnal alternating in this paper shows Buck converter, the perturbation method, and the MPPT control strategy can be applied to the Jiuquan solar photovoltaic power generation, which can make the output of an equivalent impedance circuit with PV battery output impedance, the photovoltaic array in any condition to obtain the maximum power output, the advantages of tracking maximum power. Simulation results show that MPPT the feasibility of the control strategy, the proposed method can effectively improve the stability of the output voltage.%太阳能光伏发电作为一种新能源，易受季节变化、昼夜交替的影响，因此其输出电压很不稳定．鉴于此，本文采用Buck变换器，采用扰动观察法的MPPT控制策略，可应用到酒泉的太阳能光伏发电中，可使得输出电路的等效阻抗跟随光伏电池的输出阻抗，使光伏阵列在任何条件下获得最大功率输出，跟踪最大功率的优点．仿真表明，MPPT（最大功率跟踪）控制策略的可行性，该方法有效地提高了输出电压的稳定性．
Controller for a wave energy converter
Wilson, David G.; Bull, Diana L.; Robinett, III, Rush D.
2015-09-22
A wave energy converter (WEC) is described, the WEC including a power take off (PTO) that converts relative motion of bodies of the WEC into electrical energy. A controller controls operation of the PTO, causing the PTO to act as a motor to widen a wave frequency spectrum that is usable to generate electrical energy.
Galvanically Isolated Quasi-Z-Source DC–DC Converter With a Novel ZVS and ZCS Technique
DEFF Research Database (Denmark)
Husev, Oleksandr; Liivik, Liisa; Blaabjerg, Frede
2015-01-01
This paper focuses on the galvanically isolated quasi-Z-source dc-dc converter with a novel zero voltage and zero current switching technique. The unique feature of the impedance network lies in combining the buck-boost operation capability with the short- and open-circuit immunity of transistors......; at the same time, it can perform zero voltage and zero current switching on the primary side. The boundary conduction mode of the current in the second inductor of the quasi-Z-source network was used along with snubber capacitors in the two out of four transistors and a special control algorithm to achieve...
EFFECT OF MUCUNA (Mucuna pruriens) ON SPERMIOGRAMS OF WEST AFRICAN DWARF BUCKS
James Olamitibo Daramola; John Adesanya Abiona; Olusiji Frederick Smith; Olubunkola Ajike Isah; Olusiji Sunday Sowande; Moshood Olajire Olaniyi; Jimoh Alao Olanite
2015-01-01
The study was carried out to investigate the potential effect of Mucuna pruriens seed powder on spermiograms of West African Dwarf bucks (WAD). Twenty bucks were randomly assigned to five treatments consisting of four animals each receiving 0, 25, 50, 75, 100mg/Bw of Mucuna pruriens seed powder administered via oral route for 30 days consecutively. Following treatment, spermiograms of the animals were determined. The results showed that exposure of bucks to Mucuna pruriens powder led to a sig...
Assessment of goat breed improvement through distribution of beetal bucks in rainfed pothwar, Punjab
International Nuclear Information System (INIS)
Akmal, N.; Shah, H.; Niazi, N.
2010-01-01
The present paper is based on the assessment of goat breed improvement intervention through supply of 65 Beetal bucks in rainfed Pothwar. To judge short term impact and assessment, a survey was carried out of both buck holder and non-holder beneficiaries in six project tehsils, after one year of buck distribution. Data were collected from a sample of 38 buck holders and 31 beneficiary farmers using a structured pretested questionnaire. The main influencing factor in keeping bucks was goat breed improvement. All the sample respondents were convinced of the benefits of crosses with Beetal buck and reported that the offsprings Beetal were of higher body weight (40% higher), good looking and well built. Regarding the suitability of Beetal with fodder and forage in the area, majority of the farmers (73%) considered it more suitable. There was a price difference of Rs. 1277 for male kids and Rs. 697 for female kids of the same age than the kids from local buck crosses. The farmers believed that the price difference was not only due to the higher weight but a better look and better structure of the Beetal goat. Farming community showed keen interest in using this intervention on a regular basis. (author)
Energy Technology Data Exchange (ETDEWEB)
Jammes, B; Marpinard, J C
1996-12-31
Neural networks are scarcely applied to power electronics. This attempt includes two different topics: optimal control and computerized simulation. The learning has been performed through output error feedback. For implementation, a buck converter has been used as a voltage pulse generator. (D.L.) 7 refs.
Fuzzy Controller Design Using FPGA for Photovoltaic Maximum Power Point Tracking
Basil M Hamed; Mohammed S. El-Moghany
2012-01-01
The cell has optimum operating point to be able to get maximum power. To obtain Maximum Power from photovoltaic array, photovoltaic power system usually requires Maximum Power Point Tracking (MPPT) controller. This paper provides a small power photovoltaic control system based on fuzzy control with FPGA technology design and implementation for MPPT. The system composed of photovoltaic module, buck converter and the fuzzy logic controller implemented on FPGA for controlling on/off time of MOSF...
Fuzzy Controlled Parallel AC-DC Converter for PFC
Directory of Open Access Journals (Sweden)
M Subba Rao
2011-01-01
Full Text Available Paralleling of converter modules is a well-known technique that is often used in medium-power applications to achieve the desired output power by using smaller size of high frequency transformers and inductors. In this paper, a parallel-connected single-phase PFC topology using flyback and forward converters is proposed to improve the output voltage regulation with simultaneous input power factor correction (PFC and control. The goal of the control is to stabilize the output voltage of the converter against the load variations. The paper presents the derivation of fuzzy control rules for the dc/dc converter circuit and control algorithm for regulating the dc/dc converter. This paper presents a design example and circuit analysis for 200 W power supply. The proposed approach offers cost effective, compact and efficient AC/DC converter by the use of parallel power processing. MATLAB/SIMULINK is used for implementation and simulation results show the performance improvement.
Buckli,J
1988-01-01
L'association du personnel a le plaisir d'accueillir Mons. James F.Buckli, astronaute, né en 1947. Il a participé à la mission Space Lab D1 qui pour la première fois mettait 8 personnes sur orbite.L'ass.du pers. remercie aussi Gordon White(s) de la mission américaine d'avoir permis d'organiser cette conférence
Fuzzy Control of a Lead Acid Battery Charger
Directory of Open Access Journals (Sweden)
A. DAOUD
2005-03-01
Full Text Available In this paper, an alternative battery charging control technique based on fuzzy logic for photovoltaic (PV applications is presented. A PV module is connected to a buck type DC/DC power converter and a microcontroller based unit is used to control the lead acid battery charging voltage. The fuzzy control is used due to the simplicity of implementation, robustness and independence from the complex mathematical representation of the battery. The usefulness of this control method is confirmed by experiments.
Mao, Mingxuan; Duan, Qichang; Zhang, Li; Chen, Hao; Hu, Bei; Duan, Pan
2017-08-24
The paper presents a novel two-stage particle swarm optimization (PSO) for the maximum power point tracking (MPPT) control of a PV system consisting of cascaded PV-converter modules, under partial shading conditions (PSCs). In this scheme, the grouping method of the shuffled frog leaping algorithm (SFLA) is incorporated with the basic PSO algorithm, ensuring fast and accurate searching of the global extremum. An adaptive speed factor is also introduced to improve its convergence speed. A PWM algorithm enabling permuted switching of the PV sources is applied. The method enables this PV system to achieve the maximum power generation for any number of PV and converter modules. Simulation studies of the proposed MPPT scheme are performed on a system having two chained PV buck-converter modules and a dc-ac H-bridge connected at its terminals for supplying an AC load. The results show that this type of PV system allows each module to achieve the maximum power generation according its illumination level without affecting the others, and the proposed new control method gives significantly higher power output compared with the conventional P&O and PSO methods.
Non-synchronous control of self-oscillating resonant converters
Glaser, John Stanley; Zane, Regan Andrew
2002-01-01
A self-oscillating switching power converter has a controllable reactance including an active device connected to a reactive element, wherein the effective reactance of the reactance and the active device is controlled such that the control waveform for the active device is binary digital and is not synchronized with the switching converter output frequency. The active device is turned completely on and off at a frequency that is substantially greater than the maximum frequency imposed on the output terminals of the active device. The effect is to vary the average resistance across the active device output terminals, and thus the effective output reactance, thereby providing converter output control, while maintaining the response speed of the converter.
Effects of Enrofloxacin Administration on Semen Quality of Barbari bucks
Directory of Open Access Journals (Sweden)
Chandrima Sinha
2012-07-01
Full Text Available The present study was undertaken to study the effect of enrofloxacin administration on semen quality of Barbari buck. Six normal, healthy adult Barbari bucks (25-30 Kg aged between 2 to 2.5 years were used as semen donors. The bucks were administered enrofloxacin at the dose of 5mg/kg body weight intra-muscularly daily for 7 days. From each buck biweekly eighteen semen ejaculates (1st to 18th were collected and one sample (0th from each buck was collected before administration of enrofloxacin, using a non-oestrous doe as dummy and investigated for semen quality parameters. There was no significant difference (P≥0.05 in seminal volume between different ejaculates. Mass motility decreased significantly (P≤0.01 and was lowest in 4th ejaculate as compared to mass motility prior to drug administration. Highest significant (P≤0.01 decrease in progressive motility was seen in 9th ejaculate as compared to progressive motility before drug administration. Sperm concentration decreased significantly (P≤0.01 and was found to be lowest in 4th ejaculate as compared to sperm concentration before enrofloxacin administration. Percent live spermatozoa decreased significantly (P≤0.01 and was found to be minmum in 12th ejaculate as compared to sperm concentration prior to drug administration. Highest significant increase (P≤ 0.01 in per cent head, mid-piece and tail abnormalities of spermatozoa was observed in 4th, 3rd and 6th ejaculate respectively following parentral administration of enrofloxacion as compared to ejaculate before drug administration. Following drug administration, the semen quality decreased progressively and then became slowly normal after 14th ejaculate.
Buck Creek River Flow Analysis
Dhanapala, Yasas; George, Elizabeth; Ritter, John
2009-04-01
Buck Creek flowing through Springfield Ohio has a number of low-head dams currently in place that cause safety issues and sometimes make it impossible for recreational boaters to pass through. The safety issues include the back eddies created by the dams that are known as drowning machines and the hydraulic jumps. In this study we are modeling the flow of Buck Creek using topographical and flow data provided by the Geology Department of Wittenberg University. The flow is analyzed using Hydraulic Engineering Center - River Analysis System software (HEC-RAS). As the first step a model of the river near Snyder Park has been created with the current structure in place for validation purposes. Afterwards the low-head dam is replaced with four drop structures with V-notch overflow gates. The river bed is altered to reflect plunge pools after each drop structure. This analysis will provide insight to how the flow is going to behave after the changes are made. In addition a sediment transport analysis is also being conducted to provide information about the stability of these structures.
Power electronic converters modeling and control with case studies
Bacha, Seddik; Bratcu, Antoneta Iuliana
2014-01-01
Modern power electronic converters are involved in a very broad spectrum of applications: switched-mode power supplies, electrical-machine-motion-control, active power filters, distributed power generation, flexible AC transmission systems, renewable energy conversion systems and vehicular technology, among them. Power Electronics Converters Modeling and Control teaches the reader how to analyze and model the behavior of converters and so to improve their design and control. Dealing with a set of confirmed algorithms specifically developed for use with power converters, this text is in two parts: models and control methods. The first is a detailed exposition of the most usual power converter models: · switched and averaged models; · small/large-signal models; and · time/frequency models. The second focuses on three groups of control methods: · linear control approaches normally associated with power converters; · resonant controllers b...
Aalborg Inverter - A new type of “Buck in Buck, Boost in Boost” Grid-tied Inverter
DEFF Research Database (Denmark)
Wu, Weimin; Blaabjerg, Frede
2013-01-01
This paper presents a new family of high efficiency DC/AC grid-tied inverter with a wide variation of input DC voltage. It is a kind of “Boost in Boost, Buck in Buck” inverter, meaning that only one power stage works at the high frequency to achieve the minimum switching loss. Furthermore......, the minimum filtering inductance in the power loop is achieved to reduce the conduction power loss whether in “Boost” or “Buck” mode. In theory, it can achieve higher efficiency than other inverters under the same condition of input DC voltage. The principle of operation is fully illustrated through...... the analysis on the equivalent circuits of a “three-level” single-phase inverter. Simulations show it has good control performance....
Artificial neural network control of sab dc/dc converter
International Nuclear Information System (INIS)
Mahar, M.A.; Abro, M.R.; Larik, A.S.
2009-01-01
The latest development of power semiconductor devices enable the modern power electronic converters to withstand high voltage and high power applications. Power electronic converters are mostly periodic variable structure systems due to their switched operations. The main drawback of these converters is the generation of oscillations which are developed during the operation of the converters under nonlinear situations. To handle these nonlinearities, various researchers have proposed different control techniques. Power electronic designers are devoting in the further development of converter topologies and their control techniques. SAB (Single Active Bridge) DC/DC converter is a new topology recently introduced by Demetriades. This topology is used in high voltage and high power applications. Because of its smart features, SAB converter has recently drawn attention of many researchers. However, during the operation of SAB converter severe oscillations are generated. In this research work, a novel NNC (Neural Network Controller) model is developed for SAB converter to minimize oscillations generated during its operation. NNC is believed to be an advanced nonlinear and robust controller which has the ability to map the nonlinear behaviour in a negligible response time. The performance of SAB converter with NNC is tested under dynamic region by considering the reference voltage variation and duty ratio variation. The SAB converter is implemented and simulated in MATLAB/Simulink. The simulated results are presented. (author)
Cross Voltage Control with Inner Hysteresis Current Control for Multi-output Boost Converter
DEFF Research Database (Denmark)
Nami, Alireza; Zare, Firuz; Blaabjerg, Frede
2009-01-01
Multi-output boost (MOB) converter is a novel DC-DC converter unlike the regular boost converter, has the ability to share its total output voltage and to have different series output voltage from a given duty cycle for low and high power applications. In this paper, discrete voltage control...... with inner hysteresis current control loop has been proposed to keep the simplicity of the control law for the double-output MOB converter, which can be implemented by a combination of analogue and logical ICs or simple microcontroller to constrain the output voltages of MOB converter at their reference...... voltages against variation in load or input voltage. The salient features of the proposed control strategy are simplicity of implementation and ease to extend to multiple outputs in the MOB converter. Simulation and experimental results are presented to show the validity of control strategy....
Impedance coordinative control for cascaded converter in bidirectional application
DEFF Research Database (Denmark)
Tian, Yanjun; Loh, Poh Chiang; Deng, Fujin
2016-01-01
A two-stage cascaded converter is formed by connecting two sub-converters in series. Output impedance of one sub-converter will therefore interact with input impedance of the other sub-converter. Such interaction may affect the system dynamics and stability, especially when one sub......-converter is constant-power-controlled, and hence has different impedance characteristics when its power reverses. To lessen such constant-power effects, a control scheme that can coordinate impedance behaviors of the two sub-converters is proposed. The idea is to reshape the lowfrequency negative impedance...
Bi-directional power control system for voltage converter
Garrigan, Neil Richard; King, Robert Dean; Schwartz, James Edward
1999-01-01
A control system for a voltage converter includes: a power comparator for comparing a power signal on input terminals of the converter with a commanded power signal and producing a power comparison signal; a power regulator for transforming the power comparison signal to a commanded current signal; a current comparator for comparing the commanded current signal with a measured current signal on output terminals of the converter and producing a current comparison signal; a current regulator for transforming the current comparison signal to a pulse width modulator (PWM) duty cycle command signal; and a PWM for using the PWM duty cycle command signal to control electrical switches of the converter. The control system may further include: a command multiplier for converting a voltage signal across the output terminals of the converter to a gain signal having a value between zero (0) and unity (1), and a power multiplier for multiplying the commanded power signal by the gain signal to provide a limited commanded power signal, wherein power comparator compares the limited commanded power signal with the power signal on the input terminals.
Synchronous Control of Modular Multilevel Converters
DEFF Research Database (Denmark)
Oleschuk, Valentin; Blaabjerg, Frede; Bose, Bimal K.
2002-01-01
A novel method of direct synchronous pulsewidth modulation (PWM) is applied for control of modular multilevel converters consisting from three standard triphase inverter modules along with an 0.33 p.u. output transformer. The proposed method provides synchronisation of the voltage waveforms...... for each module and the composed voltage at the output of the converter. Multilevel output voltage of the converter has quarter-wave symmetry during the whole range including the zone of overmodulation. Both continuous and discontinuous versions of synchronous PWM, based on vector approach...
Adaptive electrothermal protection of power converters
Directory of Open Access Journals (Sweden)
Baraniuk G. A.
2017-06-01
Full Text Available Thermal management for power converters during normal operation and transient modes when electrical components are warmed up is an actual problem. This can be particularly important for converters with intermittent duty operation, e.g. power supplies for resistance welding. According to some research, nearly 60% of failures are temperature-induced, and for every 10°C temperature rise in operating environment the failure rate nearly doubles. In this paper, thermal motion of state equations eigenvalue is analysed. It is shown, that in semiconductor converters with an output smoothing filter it is appropriate to use thermal protection devices based on thermal normalisation of the converter filter and, while for cases when short circuits are possible it is appropriate to use a soft start system with thermal adaptation for soft start time factor. Based on these results, two systems of thermal protections operating for semiconductor power converters are introduced. Simulation of combined electromagnetic and thermal processes in buck converter operating with both thermal management systems in overlapping environments MATLAB/Simulink and PLECS showed the possibility to significantly reduce thermal shock on semiconductor components. Using the system of filter parameters normalisation decreases the temperature of the crystal from 210°C to 85°C, using the adaptive soft start system decreases the temperature from 180°C to 80°C. The simulation results are confirmed by tests on real devices.
Optimization Control of Bidirectional Cascaded DC-AC Converter Systems
DEFF Research Database (Denmark)
Tian, Yanjun
in bidirectional cascaded converter. This research work analyses the control strategies based on the topology of dual active bridges converter cascaded with a three phase inverter. It firstly proposed a dc link voltage and active power coordinative control method for this cascaded topology, and it can reduce dc....... The connections of the renewable energy sources to the power system are mostly through the power electronic converters. Moreover, for high controllability and flexibility, power electronic devices are gradually acting as the interface between different networks in power systems, promoting conventional power...... the bidirectional power flow in the distribution level of power systems. Therefore direct contact of converters introduces significant uncertainties to power system, especially for the stability and reliability. This dissertation studies the optimization control of the two stages directly connected converters...
Directory of Open Access Journals (Sweden)
Chih-Lung Shen
2013-01-01
Full Text Available A self-oscillating high-voltage generator is proposed to supply voltage for a suspension system in order to control the damping force of an electrorheological (ER fluid shock absorber. By controlling the output voltage level of the generator, the damping force in the ER fluid shock absorber can be adjusted immediately. The shock absorber is part of the suspension system. The high-voltage generator drives a power transistor based on self-excited oscillation, which converts dc to ac. A high-frequency transformer with high turns ratio is used to increase the voltage. In addition, the system uses the car battery as dc power supply. By regulating the duty cycle of the main switch in the buck converter, the output voltage of the buck converter can be linearly adjusted so as to obtain a specific high voltage for ER. The driving system is self-excited; that is, no additional external driving circuit is required. Thus, it reduces cost and simplifies system structure. A prototype version of the actual product is studied to measure and evaluate the key waveforms. The feasibility of the proposed system is verified based on experimental results.
Radiometric sampling of bucked copper-nickel ores for determining chemical composition
International Nuclear Information System (INIS)
Komlev, V.N.; Eliseev, G.I.
1978-01-01
Presented are the results and the technique of experimental-methodical works on radiometric sampling of bucked copper-nickel ores for determining chemical composition with their selection and analysis by the neutron-gamma method and by the gamma-gamma method. The error is estimated according to the chosen conditions of sampling. It is found that the gamma-gamma method being more rapid but less accurate is applied for rapid control of ore current, whereas the neutron-gamma method is applied for quality control of ores extracted
Directory of Open Access Journals (Sweden)
Taofik Adam Ibrahim
2018-04-01
Full Text Available This study evaluated nutrient utilisation and blood chemistry of Red Sokoto bucks fed a 10 and 20 % inclusion level of raw, water- and lime-soaked Hibiscus sabdariffa L. seeds in rice bran based diets. 21 Red Sokoto bucks aged 8–10 months and weighing 9–13 kg were randomly allotted into six treatments with three bucks each, while a seventh dietary treatment with zero inclusion of seeds served as control in a 2 × 3 factorial arrangement using a complete randomised design. The results indicated that increase in dietary inclusion levels of soaked H. sabdariffa seeds increased (P < 0.05 the nutrient utilisation of bucks as compared to the control, while a decrease was observed with increasing dietary inclusion levels of raw seeds. Dietary inclusion of both raw and water-soaked H. sabdariffa seeds increased (P < 0.05 the packed cell volume. Soaking also influenced the white blood cell value which increased with increasing inclusion levels of H. sabdariffa seeds. However, values of haemoglobin and red blood cells were only affected by 20 % inclusion of raw and water-soaked H. sabdariffa seeds (P < 0.05 compared to control. Inclusion of H. sabdariffa seeds furthermore reduced serum protein, albumin, globulin, glucose and urea levels compared to control. It is therefore concluded that H. sabdariffa seeds support haematopoiesis in Red Sokoto bucks. While both inclusion levels of water-soaked and 10 % raw H. sabdariffa seeds improved nutrient utilisation compared to control and 20 % inclusion of raw seeds, the 20 % inclusion of water-soaked H. sabdariffa seeds recorded the best nitrogen utilisation efficiency.
Connection coefficients between Boas-Buck polynomial sets
Cheikh, Y. Ben; Chaggara, H.
2006-07-01
In this paper, a general method to express explicitly connection coefficients between two Boas-Buck polynomial sets is presented. As application, we consider some generalized hypergeometric polynomials, from which we derive some well-known results including duplication and inversion formulas.
Design of resonant converter based DC power supply for RF amplifier
International Nuclear Information System (INIS)
Mohan, Kartik; Suthar, Gajendra; Dalicha, Hrushikesh; Agarwal, Rohit; Trivedi, R.G.; Mukherjee, Aparajita
2017-01-01
ITER require 20 MW of RF power to a large variety of plasmas in the Ion Cyclotron frequency range for heating and driving plasma current. Nine RF sources of 2.5MW RF power level each collectively will accomplish the above requirement. Each RF source consists of SSPA, driver and end stage, above which driver and end stage amplifier are tube (Tetrode/Diacrode) based which requires auxiliary DC power source viz. filament, screen grid and control grid DC power supply. DC power supply has some stringent requirements like low stored energy, fast turn off, and low ripple value, etc. This paper will focus only on Zero Current Switching (ZCS) resonant converter based buck converter. This can serve the purpose of control grid and screen grid DC power supply for above requirement. IGBT switch will be used at 20 kHz so as to lower the filter requirement hence low stored energy and ripple in the output voltage. ZCS operation will also assist us in reducing EMI/EMC effect. Design of resonant tank circuit is important aspect of the converter as it forms the backbone of the complete system and basis of selection of other important parameters as well hence mathematical model analysis with the help of circuit equations for various modes have been shown as a part of selection criteria. Peak current through the switch, duty cycle, switching frequency will be the design parameters for selecting resonant tank circuit
A Control Method of Current Type Matrix Converter for Plasma Control Coil Power Supply
International Nuclear Information System (INIS)
Shimada, K.; Matsukawa, M.; Kurihara, K.; Jun-ichi Itoh
2006-01-01
In exploration to a tokamak fusion reactor, the control of plasma instabilities of high β plasma such as neoclassical tearing mode (NTM), resistive wall mode (RWM) etc., is the key issue for steady-state sustainment. One of the proposed methods to avoid suppressing RWM is that AC current having a phase to work for reduction the RWM growth is generated in a coil (sector coil) equipped spirally on the plasma vacuum vessel. To stabilize RWM, precise and fast real-time feedback control of magnetic field with proper amplitude and frequency is necessary. This implies that an appropriate power supply dedicated for such an application is expected to be developed. A matrix converter as one of power supply candidates for this purpose could provide a solution The matrix converter, categorized in an AC/AC direct converter composed of nine bi-directional current switches, has a great feature that a large energy storage element is unnecessary in comparison with a standard existing AC/AC indirect converter, which is composed of an AC/DC converter and a DC/AC inverter. It is also advantageous in cost and size of its applications. Fortunately, a voltage type matrix converter has come to be available at the market recently, while a current type matrix converter, which is advantageous for fast control of the large-inductance coil current, has been unavailable. On the background above mentioned, we proposed a new current type matrix converter and its control method applicable to a power supply with fast response for suppressing plasma instabilities. Since this converter is required with high accuracy control, the gate control method is adopted to three-phase switching method using middle phase to reduce voltage and current waveforms distortion. The control system is composed of VME-bus board with DSP (Digital Signal Processor) and FPGA (Field Programmable Gate Array) for high speed calculation and control. This paper describes the control method of a current type matrix converter
DEFF Research Database (Denmark)
Teodorescu, Remus; Blaabjerg, Frede
2004-01-01
This paper is describing the recently introduced proportional-resonant (PR) controllers and their suitability for grid-connected converters current control. It is shown that the known shortcomings associated with PI controllers like steady - state error for single-phase converters and the need...... of decoupling for three-phase converters can be alleviated. Additionally, selective harmonic compensation is also possible with PR controllers. Suggested control-diagrams for three-phase grid converters and active filters are also presented. A practical application of PR current control for a photovoltaic (PV...
Electrothermal model of choking-coils for the analysis of dc-dc converters
Energy Technology Data Exchange (ETDEWEB)
Gorecki, Krzysztof, E-mail: gorecki@am.gdynia.pl [Gdynia Maritime University, Department of Marine Electronics, Morska 83, Gdynia (Poland); Detka, Kalina [Pomeranian Higher School in Gdynia, Opata Hackiego 8-10, Gdynia (Poland)
2012-09-01
The paper concerns modelling the choking-coil for the needs of the electrothermal analysis of dc-dc converters. A new electrothermal model of the choking-coil is proposed. This model is dedicated for SPICE software and it takes into account nonlinearity of the dependences of the inductance on the current, selfheating and mutual thermal interactions between the core and the winding. The structure of this model is described in detail and its correctness is experimentally verified for the choking-coils with the ferrite and powder cores. Both the characteristics of the choking-coils and the buck converter with these choking-coils were considered. The satisfying agreement between the results of calculations and measurements is obtained.
Electrothermal model of choking-coils for the analysis of dc–dc converters
International Nuclear Information System (INIS)
Górecki, Krzysztof; Detka, Kalina
2012-01-01
The paper concerns modelling the choking-coil for the needs of the electrothermal analysis of dc–dc converters. A new electrothermal model of the choking-coil is proposed. This model is dedicated for SPICE software and it takes into account nonlinearity of the dependences of the inductance on the current, selfheating and mutual thermal interactions between the core and the winding. The structure of this model is described in detail and its correctness is experimentally verified for the choking-coils with the ferrite and powder cores. Both the characteristics of the choking-coils and the buck converter with these choking-coils were considered. The satisfying agreement between the results of calculations and measurements is obtained.
On and off controlled resonant dc-dc power converter
DEFF Research Database (Denmark)
2015-01-01
The present invention relates to a resonant DC-DC power converter comprising an input side circuit comprising a positive and a negative input terminal for receipt of an input voltage or current and an output side circuit comprising positive and negative output terminals for supply of a converter...... output voltage and connection to a converter load. The resonant DC-DC power converter further comprises a rectification circuit connected between an output of a resonant network and the output side circuit. The resonant network is configured for alternatingly being charged from the input voltage...... or current and discharged through the rectification circuit by a first controllable switch arrangement in accordance with a first switch control signal. A second controllable switch arrangement of the resonant DC-DC power converter is configured to select a first impedance characteristic of the resonant...
Power flow controller with a fractionally rated back-to-back converter
Divan, Deepakraj M.; Kandula, Rajendra Prasad; Prasai, Anish
2016-03-08
A power flow controller with a fractionally rated back-to-back (BTB) converter is provided. The power flow controller provide dynamic control of both active and reactive power of a power system. The power flow controller inserts a voltage with controllable magnitude and phase between two AC sources at the same frequency; thereby effecting control of active and reactive power flows between the two AC sources. A transformer may be augmented with a fractionally rated bi-directional Back to Back (BTB) converter. The fractionally rated BTB converter comprises a transformer side converter (TSC), a direct-current (DC) link, and a line side converter (LSC). By controlling the switches of the BTB converter, the effective phase angle between the two AC source voltages may be regulated, and the amplitude of the voltage inserted by the power flow controller may be adjusted with respect to the AC source voltages.
Optimal trajectory control of a CLCC resonant power converter
Huisman, H.; Visser, de I.; Duarte, J.L.
2015-01-01
A CLCC resonant converter to be used in an isolated power supply is operated using optimal trajectory control (OTC). As a consequence, the converter's inner loop behavior is changed to that of a controlled current source. The controller is implemented in an FPGA. Simulation results and recorded
The New Modular Control System for Power Converters at CERN
Di Cosmo, Matteo
2015-01-01
The CERN accelerator complex consists of several generations of particle accelerators, with around 5000 power converters supplying regulated current and voltage to normal and superconducting magnet circuits. Today around 12 generations of converter control platforms can be found in the accelerator complex, ranging in age and technology. The diversity of these platforms has a significant impact on operability, maintenance and support of power converters. Over the past few years a new generation of modular controls called RegFGC3 has been developed by CERN’s power conversion group, with a goal to provide a standardised control platform, supporting a wide variety of converter topologies. The aim of this project is to reduce maintenance costs by decreasing the variety and diversity of control systems whilst simultaneously improving the operability and reliability of power converters and their controls. This paper describes the state of the on-going design and realization of the RegFGC3 platform, focusing on fun...
Automatic control in multidrive electrotechnical complexes with semiconductor converters
Vasilev, B. U.; Mardashov, D. V.
2017-01-01
The frequency convertor and the automatic control system, which can be used in the multi-drive electromechanical system with a few induction motions, are considered. The paper presents the structure of existing modern multi-drive electric drives inverters, namely, electric drives with a total frequency converter and few electric motions, and an electric drive, in which the converter is used for power supply and control of the independent frequency. It was shown that such technical solutions of frequency converters possess a number of drawbacks. The drawbacks are given. It was shown that the control of technological processes using the electric drive of this structure may be provided under very limited conditions, as the energy efficiency and the level of electromagnetic compatibility of electric drives is low. The authors proposed using a multi-inverter structure with an active rectifier in multidrive electric drives with induction motors frequency converters. The application of such frequency converter may solve the problem of electromagnetic compatibility, namely, consumption of sinusoidal currents from the network and the maintenance of a sinusoidal voltage and energy compatibility, namely, consumption of practically active energy from the network. Also, the paper proposes the use of the automatic control system, which by means of a multi-inverter frequency converter provides separate control of drive machines and flexible regulation of technological processes. The authors present oscillograms, which confirm the described characteristics of the developed electrical drive. The possible subsequent ways to improve the multi-motor drives are also described.
Efficiency and reliability improvement in wind turbine converters by grid converter adaptive control
DEFF Research Database (Denmark)
Trintis, Ionut; Munk-Nielsen, Stig; Abrahamsen, Flemming
2013-01-01
This paper presents a control method that reduces the losses in wind turbine converters adaptively controlling the grid converter. The dc-link voltage adapts its reference based on the system state and therefore reduces the stored energy, and is therefore kept at the minimum necessary for the grid...... and generator side. Operating in this way, the electrical and thermal stress factors are decreased on the power electronic devices, increasing their lifetime. The simulation results using this method show efficiency increase and devices temperature cycles slightly decreased. Experimental results on a wind...... turbine power stack shows efficiency increase in the high power region....
Coordinated Control of Wave Energy Converters Subject to Motion Constraints
Directory of Open Access Journals (Sweden)
Liguo Wang
2016-06-01
Full Text Available In this paper, a generic coordinated control method for wave energy converters is proposed, and the constraints on motion amplitudes and the hydrodynamic interaction between converters are considered. The objective of the control problem is to maximize the energy converted from ocean waves, and this is achieved by coordinating the power take-off (PTO damping of each wave energy converter in the frequency domain in each sea state. In a case study, a wave energy farm consisting of four converters based on the concept developed by Uppsala University is studied. In the solution, motion constraints, including constraints on the amplitudes of displacement and velocity, are included. Twelve months of sea states, based on measured wave data at the Lysekil test site on the Swedish west coast, are used in the simulation to evaluate the performance of the wave energy farm using the new method. Results from the new coordinated control method and traditional control method are compared, indicating that the coordinated control of wave energy converters is an effective way to improve the energy production of wave energy farm in harmonic waves.
Implementation of optimal trajectory control of series resonant converter
Oruganti, Ramesh; Yang, James J.; Lee, Fred C.
1987-01-01
Due to the presence of a high-frequency LC tank circuit, the dynamics of a resonant converter are unpredictable. There is often a large surge of tank energy during transients. Using state-plane analysis technique, an optimal trajectory control utilizing the desired solution trajectory as the control law was previously proposed for the series resonant converters. The method predicts the fastest response possible with minimum energy surge in the resonant tank. The principle of the control and its experimental implementation are described here. The dynamics of the converter are shown to be close to time-optimal.
Diode-Assisted Buck-Boost Current Source Inverters
DEFF Research Database (Denmark)
Gao, F.; Cai, Liang; Loh, P.C.
2007-01-01
This paper presents a couple of novel current source inverters (CSIs) with the enhanced current buckboost capability. With the unique diode-inductor network added between current source inverter circuitry and current boost elements, the proposed buck-boost current source inverters demonstrate...... uninfluenced. Lastly, all theoretical findings were verified experimentally using constructed laboratory prototypes....
International Nuclear Information System (INIS)
Hardik, P. Desai; Ranjan Maheshwari
2011-01-01
This paper investigates the interest focused on employing parallel connected dc-dc converter with high tracking effectiveness under wide variation in environmental conditions (Insolation) and wide load variation. dc-dc converter is an essential part of the stand alone PV system. Paper also presents an approach on how duty cycle for maximum power position (MPP) is adjusted by taking care of varying load conditions and without iterative steps. Synchronized PWM pulses are employed for the converter. High tracking efficiency is achieved with continuous input and inductor current. In this approach, the converter can he utilized in buck as well in boost mode. The PV system simulation was verified and experimental results were in agreement to the presented scheme. (authors)
Wilson, P. M.; Wilson, T. G.; Owen, H. A., Jr.
Dc to dc converters which operate reliably and efficiently at switching frequencies high enough to effect substantial reductions in the size and weight of converter energy storage elements are studied. A two winding current or voltage stepup (buck boost) dc-to-dc converter power stage submodule designed to operate in the 2.5-kW range, with an input voltage range of 110 to 180 V dc, and an output voltage of 250 V dc is emphasized. In order to assess the limitations of present day component and circuit technologies, a design goal switching frequency of 10 kHz was maintained. The converter design requirements represent a unique combination of high frequency, high voltage, and high power operation. The turn off dynamics of the primary circuit power switching transistor and its associated turn off snubber circuitry are investigated.
Adaptive Quasi-Sliding Mode Control for Permanent Magnet DC Motor
Directory of Open Access Journals (Sweden)
Fredy E. Hoyos
2013-01-01
Full Text Available The motor speed of a buck power converter and DC motor coupled system is controlled by means of a quasi-sliding scheme. The fixed point inducting control technique and the zero average dynamics strategy are used in the controller design. To estimate the load and friction torques an online estimator, computed by the least mean squares method, is used. The control scheme is tested in a rapid control prototyping system which is based on digital signal processing for a dSPACE platform. The closed loop system exhibits adequate performance, and experimental and simulation results match.
Model Predictive Control of a Wave Energy Converter
DEFF Research Database (Denmark)
Andersen, Palle; Pedersen, Tom Søndergård; Nielsen, Kirsten Mølgaard
2015-01-01
In this paper reactive control and Model Predictive Control (MPC) for a Wave Energy Converter (WEC) are compared. The analysis is based on a WEC from Wave Star A/S designed as a point absorber. The model predictive controller uses wave models based on the dominating sea states combined with a model...... connecting undisturbed wave sequences to sequences of torque. Losses in the conversion from mechanical to electrical power are taken into account in two ways. Conventional reactive controllers are tuned for each sea state with the assumption that the converter has the same efficiency back and forth. MPC...
Digital control of high-frequency switched-mode power converters
Corradini, Luca; Mattavelli, Paolo; Zane, Regan
This book is focused on the fundamental aspects of analysis, modeling and design of digital control loops around high-frequency switched-mode power converters in a systematic and rigorous manner Comprehensive treatment of digital control theory for power converters Verilog and VHDL sample codes are provided Enables readers to successfully analyze, model, design, and implement voltage, current, or multi-loop digital feedback loops around switched-mode power converters Practical examples are used throughout the book to illustrate applications of the techniques developed Matlab examples are also
Modulation and control of matrix converter for aerospace application
Kobravi, Keyhan
In the context of modern aircraft systems, a major challenge is power conversion to supply the aircraft's electrical instruments. These instruments are energized through a fixed-frequency internal power grid. In an aircraft, the available sources of energy are a set of variable-speed generators which provide variable-frequency ac voltages. Therefore, to energize the internal power grid of an aircraft, the variable-frequency ac voltages should be converted to a fixed-frequency ac voltage. As a result, an ac to ac power conversion is required within an aircraft's power system. This thesis develops a Matrix Converter to energize the aircraft's internal power grid. The Matrix Converter provides a direct ac to ac power conversion. A major challenge of designing Matrix Converters for aerospace applications is to minimize the volume and weight of the converter. These parameters are minimized by increasing the switching frequency of the converter. To design a Matrix Converter operating at a high switching frequency, this thesis (i) develops a scheme to integrate fast semiconductor switches within the current available Matrix Converter topologies, i.e., MOSFET-based Matrix Converter, and (ii) develops a new modulation strategy for the Matrix Converter. This Matrix Converter and the new modulation strategy enables the operation of the converter at a switching-frequency of 40kHz. To provide a reliable source of energy, this thesis also develops a new methodology for robust control of Matrix Converter. To verify the performance of the proposed MOSFET-based Matrix Converter, modulation strategy, and control design methodology, various simulation and experimental results are presented. The experimental results are obtained under operating condition present in an aircraft. The experimental results verify the proposed Matrix Converter provides a reliable power conversion in an aircraft under extreme operating conditions. The results prove the superiority of the proposed Matrix
Design and Implementation of High Frequency Buck Converter Using Multi-Layer PCB Inductor
DEFF Research Database (Denmark)
Nour, Yasser; Ouyang, Ziwei; Knott, Arnold
2016-01-01
Increasing the switching frequency for switch mode power supplies is one of methods to achieve smaller, lighter weight and cheaper power converters. This work investigates the opportunity of using two layer circular spiral inductors implemented in a 150 μm finished thickness printed circuit board...
Aalborg Inverter - A New Type of “Buck in Buck, Boost in Boost” Grid-Tied Inverter
DEFF Research Database (Denmark)
Wu, Weimin; Ji, Junhao; Blaabjerg, Frede
2015-01-01
This paper presents a new family of high efficiency dc/ac grid-tied inverter with a wide variation of input dc voltage. It is a “boost in boost, buck in buck” inverter, meaning that only one power stage works at high frequency in order to achieve minimum switching loss. The minimum voltage drop...... of the filtering inductor in the power loop is achieved to reduce the conduction power loss in both “boost” and “buck” mode. The principle of operation is demonstrated through the analysis on the equivalent circuits of a “half-bridge” single-phase inverter. The theoretical analysis shows that when input dc voltage...... is larger than the magnitude of the ac voltage, it is a voltage-source inverter, and on the contrary it is current-source inverter in the other mode. A 220 V/50 Hz/ 2000 W prototype has been constructed. Simulations and experiments show that it has a good control and system performance....
Floating high step-down stacked dc-dc converter based on buck-boost cells
Tibola, G.; Duarte, J.L.; Blinov, A.
2015-01-01
In some high power dc-dc applications, where high voltage is present, a converter with high step-down ratio is required in order to provide an isolated low power auxiliary supply. This requirement represents a challenge and many topologies are currently being researched. The analysis of a
A Dual-Buck–Boost AC/DC Converter for DC Nanogrid With Three Terminal Outputs
DEFF Research Database (Denmark)
Wu, Weimin; Wang, Houqing; Liu, Yuan
2017-01-01
Due to the widely used dc characterized loads and more distributed power generation sources, the dc nanogrid becomes more and more popular, and it is seen as an alternative to the ac grid. For safety considerations, the dc nanogrid should provide reliable grounding for the residential loads...... such as the low-voltage ac power system. There are three typical grounding configurations for a dc nanogrid: the united grounding, the unidirectional grounding, and the virtual isolated grounding. Each grounding configuration has its own specifications to ac/dc converters. In this paper, a dual-buck-boost ac/dc...... converter for use in the united-grounding-configuration-based dc nanogrid with three terminal outputs is proposed. The working principle of this converter is presented in detail through analyzing the equivalent circuits. Experiments are carried out to verify the theoretical analysis....
Directory of Open Access Journals (Sweden)
Sergio Serna
2012-11-01
Full Text Available A novel asymmetrical interleaved dc/dc switching converters family intended for photovoltaic and fuel cell applications is presented in this paper. The main requirements on such applications are small ripples in the generator and load, as well as high voltage conversion ratio. Therefore, interleaved structures and voltage multiplier cells have been asymmetrically combined to generate new converters, which inherently operate indiscontinuous conduction mode. The novel family is derived from boost, buck-boost and flyback-based structures. This converter family is analyzed to obtain the design equations and synthesize a design process based on the typical requirements of photovoltaic and fuel cell applications. Finally, the experimental results validate the characteristics and usefulness of the asymmetrical interleaved converter family.
Multilevel Modular Converter for VSC-HVDC Transmission Applications: Control and Operational Aspects
DEFF Research Database (Denmark)
Gnanarathna, Udana N.; Gole, Aniruddha M.; Chaudhary, Sanjay Kumar
2010-01-01
Control methods for a new class of converter, the multilevel modular converter (MMC), recently introduced for HVDC transmission are discussed. The paper discusses converter-level controls including firing pulse generation and capacitor voltage balancing. It also covers higher level controls...... for incorporating the converter into a larger power network, with a weak ac receiving end. The performance behavior is studied using electromagnetic transients simulation....
Delgadillo, José Alberto; Vielma, Jesús; Hernandez, Horacio; Flores, José Alfredo; Duarte, Gerardo; Fernández, Ilda Graciela; Keller, Matthieu; Gelez, Hélène
2012-09-01
We investigated whether live vocalizations emitted by bucks interacting with anestrous females stimulate secretion of LH, estrous behavior and ovulation in anestrous goats. In experiment 1, bucks rendered sexually active by exposure to long days followed by natural photoperiod were exposed in a light-proof-building to five anestrous females. Buck vocalizations were reproduced through a microphone-amplifier-loudspeaker system to an open pen where one group of goats (n=6) was exposed for 10 days to these live vocalizations. Another group of females (n=6) was isolated from males and vocalizations. The proportion of goats displaying estrous behavior was significantly higher in females exposed to buck vocalizations than in females isolated from males. The proportion of goats that ovulated did not differ between the 2 groups (exposed to males versus isolated). In experiment 2, female goats that either had previous contact with males (n=7), or no previous contact with males (n=7) were exposed to live buck vocalizations, reproduced as described in experiment 1, for 5 days. The number and amplitude of LH pulses did not differ between groups before exposition to buck vocalizations. Five days of exposure to male vocalizations significantly increased LH pulsatility only in females that had previous contact with males, while LH pulse amplitude was not modified. We concluded that live buck vocalizations can stimulate estrous behavior and LH secretion in goats if they have had previous contact with bucks. Copyright © 2012 Elsevier Inc. All rights reserved.
A Categorization of Converter Station Controllers Within Multi-terminal DC Transmission Systems
DEFF Research Database (Denmark)
Irnawan, Roni; Silva, Filipe Miguel Faria da; Bak, Claus Leth
2016-01-01
of controller might exist in the same system. It is therefore important to identify the parameters required by the converter station controllers to ensure a smooth coordination. In this paper, different converter station controllers available in the literatures are categorized. Challenges of converter station...
Directory of Open Access Journals (Sweden)
Lourdes Gallego-Calvo
2015-12-01
Full Text Available Interest in the preservation of endangered breeds such as the Blanca Andaluza goat, has increased and some steps should be therefore taken to ensure it. The study was designed to determine the seasonal reproductive pattern of Blanca Andaluza bucks, and whether this affects the quality of their semen and its freezability over the year. Seven bucks were used and their body weight, testicular weight, plasma testosterone concentration and fresh sperm quality determined every week. The collected sperm was cryopreserved and stored; it was then thawed and the same sperm quality variables measured every fortnight. High plasma testosterone concentrations were recorded during the summer and autumn, and low concentrations were recorded during winter and spring (p<0.001. No differences were seen between seasons in terms of the percentage of bucks ejaculating, the percentage of active bucks, or ejaculate volume. However, the sperm concentration, the total number of sperm per ejaculate, and the values for most fresh sperm variables were lower during the winter period (at least p<0.05. After freezing-thawing, the quality of winter-collected sperm was better, in some respects, than that of summer-collected sperm (at least p<0.05. These results reveal that Blanca Andaluza bucks show seasonal reproductive activity in terms of their plasma testosterone concentration, but no clear change in their sexual behaviour between seasons was observed. The values of fresh sperm variables also vary over the year, reaching their lowest during winter. However, after freezing-thawing, winter-collected sperm is of overall better quality than sperm collected during the summer.
Energy Technology Data Exchange (ETDEWEB)
Gallego-Calvo, L.; Gatica, M.C.; Santiago-Moreno, J.; Guzmán, J.L.; Zarazaga, L.
2015-07-01
Interest in the preservation of endangered breeds such as the Blanca Andaluza goat, has increased and some steps should be therefore taken to ensure it. The study was designed to determine the seasonal reproductive pattern of Blanca Andaluza bucks, and whether this affects the quality of their semen and its freezability over the year. Seven bucks were used and their body weight, testicular weight, plasma testosterone concentration and fresh sperm quality determined every week. The collected sperm was cryopreserved and stored; it was then thawed and the same sperm quality variables measured every fortnight. High plasma testosterone concentrations were recorded during the summer and autumn, and low concentrations were recorded during winter and spring (p<0.001). No differences were seen between seasons in terms of the percentage of bucks ejaculating, the percentage of active bucks, or ejaculate volume. However, the sperm concentration, the total number of sperm per ejaculate, and the values for most fresh sperm variables were lower during the winter period (at least p<0.05). After freezing-thawing, the quality of winter-collected sperm was better, in some respects, than that of summer-collected sperm (at least p<0.05). These results reveal that Blanca Andaluza bucks show seasonal reproductive activity in terms of their plasma testosterone concentration, but no clear change in their sexual behaviour between seasons was observed. The values of fresh sperm variables also vary over the year, reaching their lowest during winter. However, after freezing-thawing, winter-collected sperm is of overall better quality than sperm collected during the summer. (Author)
EFFECT OF VITAMIN E ON SPERM AND OXIDATIVE STRESS PARAMETERS OF WEST AFRICAN DWARF GOAT BUCKS
Directory of Open Access Journals (Sweden)
James Olamitibo Daramola
2016-08-01
Full Text Available The aim of the present study was to determine the effect of supplementation of vitamin E on sperm and oxidative stress parameters in West African Dwarf goat bucks. The bucks were allocated to 4 treatments consisting of 0 mg, 15 mg, 30 mg and 45 mg of vitamin E. At the end of 30 days consecutive administration of vitamin E, semen and blood samples were collected and evaluated for sperm and oxidative stress parameters. The results showed that sperm motility, acrosome integrity, membrane integrity and live spermatozoa; seminal Malondialdehyde (MDA, arginase activity and leukocytes; and serum MDA and testosterone were similar in all the levels of inclusion and comparable to the control. However, higher arginase activities were observed in all the levels of vitamin E compared to the control while 15 mg of vitamin E had higher percentage of sperm abnormality compared to other treatments and the control. The findings indicated that the levels of vitamin E used did not have beneficial effect on the sperm and oxidative stress parameters. Further study of higher levels of vitamin E is therefore necessary to ascertain the appropriate level required for optimal improvement in these parameters.
Current Mode Control for LLC Series Resonant DC-to-DC Converters
Directory of Open Access Journals (Sweden)
Jinhaeng Jang
2015-06-01
Full Text Available Conventional voltage mode control only offers limited performance for LLC series resonant DC-to-DC converters experiencing wide variations in operational conditions. When the existing voltage mode control is employed, the closed-loop performance of the converter is directly affected by unavoidable changes in power stage dynamics. Thus, a specific control design optimized at one particular operating point could become unacceptable when the operational condition is varied. This paper presents a new current mode control scheme which could consistently provide good closed-loop performance for LLC resonant converters for the entire operational range. The proposed control scheme employs an additional feedback from the current of the resonant tank network to overcome the limitation of the existing voltage mode control. The superiority of the proposed current mode control over the conventional voltage mode control is verified using an experimental 150 W LLC series resonant DC-to-DC converter.
Modeling generalized interline power-flow controller (GIPFC using 48-pulse voltage source converters
Directory of Open Access Journals (Sweden)
Amir Ghorbani
2018-05-01
Full Text Available Generalized interline power-flow controller (GIPFC is one of the voltage-source controller (VSC-based flexible AC transmission system (FACTS controllers that can independently regulate the power-flow over each transmission line of a multiline system. This paper presents the modeling and performance analysis of GIPFC based on 48-pulsed voltage-source converters. This paper deals with a cascaded multilevel converter model, which is a 48-pulse (three levels voltage source converter. The voltage source converter described in this paper is a harmonic neutralized, 48-pulse GTO converter. The GIPFC controller is based on d-q orthogonal coordinates. The algorithm is verified using simulations in MATLAB/Simulink environment. Comparisons between unified power flow controller (UPFC and GIPFC are also included. Keywords: Generalized interline power-flow controller (GIPFC, Voltage source converter (VCS, 48-pulse GTO converter
On the Disillusionment of American Dream Through Buck in The Call of the Wild
Institute of Scientific and Technical Information of China (English)
吕颖
2015-01-01
The Call of the Wild,written by the famous American novelist Jack London,has attracted a large number of both readers and scholars ever since it came out.It provides the public with a fresh perspective through narrating the whole novel from the point of view of the protagonist Buck,a dog.Against the background of countless people flooding into the Alaska to search gold in order to fulfill their dream of becoming rich,which,to some extent,represents the American dream at that time,this novel vividly mirrored the then phenomenon,so illuminating and thought-provoking that it is of great value to analyze the disillusionment of American Dream through Buck.Therefore,this paper aims at exploring the disillusionment of American Dream through analyzing Buck and his rich life experiences.
Extended supervisory control of Peirce-Smith converter
International Nuclear Information System (INIS)
Hadjiski, Mincho; Boshnakov, Kosta
2014-01-01
In this paper some problems of the tight integration of the Process Control (PC) and Condition Based Maintenance (CBM) are considered in the creation of a supervised control system for Peirce-Smith Converter. The motivation of this approach is carried out on the base of numerous experimental data analyses, which show a significant improving potential. Because of a very high level of stochastic components in the direct measurements, due to the melt crystallisation a data driven degradation model is derived. A multistage procedure is proposed for effective Maintenance Decision Making (MDM) using a threshold based policy, Rule-Based Reasoning (RBR) and Case-Based Reasoning (CBR). The extended functionality of the proposed system is discussed. Key words: mathematical modelling, Peirce-Smith converter (PSC), rule-based reasoning (RBR), supervisory control, threshold based maintenance, maintenance decision making
Digital control of grid connected converters for distributed power generation
Energy Technology Data Exchange (ETDEWEB)
Skjellnes, Tore
2008-07-01
Pulse width modulated converters are becoming increasingly popular as their cost decreases and power rating increases. The new trend of small scale power producers, often using renewable energy sources, has created new demands for delivery of energy to the grid. A major advantage of the pulse width modulated converter is the ability to control the output voltage at any point in the voltage period. This enables rapid response to load changes and non-linear loads. In addition it can shape the voltage in response to the output current to create an outward appearance of a source impedance. This is called a virtual impedance. This thesis presents a controller for a voltage controlled three phase pulse width modulated converter. This controller enables operation in standalone mode, in parallel with other converters in a micro grid, and in parallel with a strong main grid. A time varying virtual impedance is presented which mainly attenuates reactive currents. A method of investigating the overall impedance including the virtual impedance is presented. New net standards have been introduced, requiring the converter to operate even during severe dips in the grid voltage. Experiments are presented verifying the operation of the controller during voltage dips. (Author). 37 refs., 65 figs., 10 tabs
Eugenics Past and Present: Remembering Buck v. Bell.
Berson, Michael J.; Cruz, Barbara
2001-01-01
Provides background information about the eugenics movement. Focuses on eugenics in the United States detailing the case, Buck v. Bell, and eugenics in Germany. Explores the present eugenic movement, focusing on "The Bell Curve," China's one child policy, and the use of eugenic sterilizations in the United States and Canada. Includes…
"The Bell Curve" and Carrie Buck: Eugenics Revisited.
Smith, J. David
1995-01-01
The 1994 publication of "The Bell Curve" by R. Herrnstein and C. Murray is compared to other examples of eugenic principles, including the sterilization of "feebleminded" Carrie Buck, family degeneracy studies focusing on lower class Caucasian families, and other works that view the poorest and least educated members of society…
Pressure intelligent control strategy of Waste heat recovery system of converter vapors
Feng, Xugang; Wu, Zhiwei; Zhang, Jiayan; Qian, Hong
2013-01-01
The converter gas evaporative cooling system is mainly used for absorbing heat in the high temperature exhaust gas which produced by the oxygen blowing reaction. Vaporization cooling steam pressure control system of converter is a nonlinear, time-varying, lagging behind, close coupling of multivariable control object. This article based on the analysis of converter operation characteristics of evaporation cooling system, of vaporization in a production run of pipe pressure variation and disturbance factors.For the dynamic characteristics of the controlled objects,we have improved the conventional PID control scheme.In Oxygen blowing process, we make intelligent control by using fuzzy-PID cascade control method and adjusting the Lance,that it can realize the optimization of the boiler steam pressure control.By design simulation, results show that the design has a good control not only ensures drum steam pressure in the context of security, enabling efficient conversion of waste heat.And the converter of 1800 flue gas through pipes and cool and dust removal also can be cooled to about 800. Therefore the converter haze evaporative cooling system has achieved to the converter haze temperature decrease effect and enhanced to the coal gas returns-ratio.
Angle Stability Analysis for Voltage-Controlled Converters
DEFF Research Database (Denmark)
Lin, Hengwei; Jia, Chenxi; Guerrero, Josep M.
2017-01-01
a criterion to analyze the quasi-steady angle stability and the direct current (DC) side stability for VSCs. The operating limit and the angle instability mechanism are revealed, which is generally applicable to the voltage-controlled converters. During the analysis, the influence of the parameters on angle...... stability is studied. Further, the difference on instability mechanism between power electronic converters and synchronous generators are explained in detail. Finally, experiment results with corrective actions verify the analysis....
Complex-Vector Time-Delay Control of Power Converters
DEFF Research Database (Denmark)
Blaabjerg, Frede; Loh, P. C.; Tang, Y.
2008-01-01
Precise controlling of current produced by power converters is an important topic that has attracted interests over the last few decades. With the recent proliferation of grid-tied converters where the control of power flow is indirectly governed by the accuracy of current tracking, motivation...... since only a small amount of memory space for storing time-delayed values and simple arithmetic computations are needed for its physical realization. In addition to that, other advantages of the scheme include its abilities to compensate for negative-sequence, load and grid harmonic components using...
Sliding-mode control of single input multiple output DC-DC converter
Zhang, Libo; Sun, Yihan; Luo, Tiejian; Wan, Qiyang
2016-10-01
Various voltage levels are required in the vehicle mounted power system. A conventional solution is to utilize an independent multiple output DC-DC converter whose cost is high and control scheme is complicated. In this paper, we design a novel SIMO DC-DC converter with sliding mode controller. The proposed converter can boost the voltage of a low-voltage input power source to a controllable high-voltage DC bus and middle-voltage output terminals, which endow the converter with characteristics of simple structure, low cost, and convenient control. In addition, the sliding mode control (SMC) technique applied in our converter can enhance the performances of a certain SIMO DC-DC converter topology. The high-voltage DC bus can be regarded as the main power source to the high-voltage facility of the vehicle mounted power system, and the middle-voltage output terminals can supply power to the low-voltage equipment on an automobile. In the respect of control algorithm, it is the first time to propose the SMC-PID (Proportion Integration Differentiation) control algorithm, in which the SMC algorithm is utilized and the PID control is attended to the conventional SMC algorithm. The PID control increases the dynamic ability of the SMC algorithm by establishing the corresponding SMC surface and introducing the attached integral of voltage error, which endow the sliding-control system with excellent dynamic performance. At last, we established the MATLAB/SIMULINK simulation model, tested performance of the system, and built the hardware prototype based on Digital Signal Processor (DSP). Results show that the sliding mode control is able to track a required trajectory, which has robustness against the uncertainties and disturbances.
Optimal control of a wave energy converter
Hendrikx, R.W.M.; Leth, J.; Andersen, P; Heemels, W.P.M.H.
2017-01-01
The optimal control strategy for a wave energy converter (WEC) with constraints on the control torque is investigated. The goal is to optimize the total energy delivered to the electricity grid. Using Pontryagin's maximum principle, the solution is found to be singular-bang. Using higher order
Control of a resonant d.c.-link converter for a.c. motor drives
Directory of Open Access Journals (Sweden)
Astrid Petterteig
1992-10-01
Full Text Available This paper presents the control of the resonant d.c.-link converter for a.c. motor drives. This is a low loss converter with higher efficiency than a conventional PWM converter, but it requires complex control. It needs a special control of the resonant d.c.-link voltage in addition to the discrete control of the a.c. side currents. Simulations show how the control of the a.c. currents, the modulation principle, influences the overall performance of the converter.
Soft-switching PWM full-bridge converters topologies, control, and design
Ruan, Xinbo
2014-01-01
Soft-switching PWM full-bridge converters have been widely used in medium-to-high power dc-dc conversions for topological simplicity, easy control and high efficiency. Early works on soft-switching PWM full-bridge converter by many researchers included various topologies and modulation strategies. However, these works were scattered, and the relationship among these topologies and modulation strategies had not been revealed. This book intends to describe systematically the soft-switching techniques for pulse-width modulation (PWM) full-bridge converters, including the topologies, control and
Three port converters used as interface in photovoltaic energy systems
Directory of Open Access Journals (Sweden)
Sarab Al-Chlaihawi
2018-04-01
Full Text Available The aim of this paper is to derive and study a full-bridge three-port converter. Based on the standard design of full-bridge converter, we have modeled and derived a three port converter. The three port converter can be used in renewable energy scenarios, such as solar cells or wind turbines connected to the input port. The input can be taken from two-ports simultaneously or from one port at a time. In order to balance the power mismatch between the input port and load port, the batteries are attached to the third port, to ensure there are no discrepancies in the power generated at the input and power demand at the load. In order to ensure isolation and reduced voltage stress on the switches, a high frequency transformer is also used in the design. The overall design contains four switches, and four diodes. MOSFETs are the strongest candidate for the switches owing to their high switching speed, lower losses and high resistance to higher voltage. Moreover, a buck-boost structure is modeled in order to ensure that it can work for a wide variety of different applications by adjusting the duty cycle of the switches properly. To minimize the switching losses in the converter, Zero-Voltage Switching (ZVS is also achievable in the modeled system.
PV power system using hybrid converter for LED indictor applications
International Nuclear Information System (INIS)
Tseng, Sheng-Yu; Wang, Hung-Yuan; Chen, Chien-Chih
2013-01-01
Highlights: • This paper presents a LED indictor driving circuit with a PV arrays as its power source. • The perturb-and-observe method is adopted to extract the maximum power of PV arrays. • The proposed circuit structure has a less component counts and higher conversion efficiency. • A prototype of LED indictor driving circuit has been implemented to verify its feasibility. • The proposed hybrid converter is suitable for LED inductor applications. - Abstract: This paper presents a LED indictor driving circuit with a PV arrays as its power source. The LED indictor driving circuit includes battery charger and discharger (LED driving circuit). In this research, buck converter is used as a charger, and forward converter with active clamp circuit is adopted as a discharger to drive the LED indictor. Their circuit structures use switch integration technique to simplify them and to form the proposed hybrid converter, which has a less component counts, lighter weight, smaller size, and higher conversion efficiency. Moreover, the proposed hybrid converter uses a perturb-and-observe method to extract the maximum power from PV arrays. Finally, a prototype of an LED indictor driving circuit with output voltage of 10 V and output power of 20 W has been implemented to verify its feasibility. It is suitable for the LED inductor applications
Neural control and transient analysis of the LCL-type resonant converter
Zouggar, S.; Nait Charif, H.; Azizi, M.
2000-07-01
This paper proposes a generalised inverse learning structure to control the LCL converter. A feedforward neural network is trained to act as an inverse model of the LCL converter then both are cascaded such that the composed system results in an identity mapping between desired response and the LCL output voltage. Using the large signal model, we analyse the transient output response of the controlled LCL converter in the case of large variation of the load. The simulation results show the efficiency of using neural networks to regulate the LCL converter.
DC-link Voltage Coordinative-Proportional Control in Cascaded Converter Systems
DEFF Research Database (Denmark)
Tian, Yanjun; Loh, Poh Chiang; Deng, Fujin
2015-01-01
PI controllers are frequently implemented in cascaded converter system to control the DC-link voltage, because they can achieve zero steady state error. However the PI controller adds a pole at the origin point and a zero on the left half plane, and it increases the control system type number......, and then the system is more difficult to control. This paper proposed a DC-link control method for the two stages cascaded converter, and it uses proportional controller for the DC-link voltage control. This control method can achieve zero steady state error on the DC-link voltage; reduce the control system type...
A fault-tolerant strategy based on SMC for current-controlled converters
Azer, Peter M.; Marei, Mostafa I.; Sattar, Ahmed A.
2018-05-01
The sliding mode control (SMC) is used to control variable structure systems such as power electronics converters. This paper presents a fault-tolerant strategy based on the SMC for current-controlled AC-DC converters. The proposed SMC is based on three sliding surfaces for the three legs of the AC-DC converter. Two sliding surfaces are assigned to control the phase currents since the input three-phase currents are balanced. Hence, the third sliding surface is considered as an extra degree of freedom which is utilised to control the neutral voltage. This action is utilised to enhance the performance of the converter during open-switch faults. The proposed fault-tolerant strategy is based on allocating the sliding surface of the faulty leg to control the neutral voltage. Consequently, the current waveform is improved. The behaviour of the current-controlled converter during different types of open-switch faults is analysed. Double switch faults include three cases: two upper switch fault; upper and lower switch fault at different legs; and two switches of the same leg. The dynamic performance of the proposed system is evaluated during healthy and open-switch fault operations. Simulation results exhibit the various merits of the proposed SMC-based fault-tolerant strategy.
Single stage buck-boost DC-AC neutral point clamped inverter
DEFF Research Database (Denmark)
Mo, Wei; Loh, Poh Chiang; Andrew, A.
2012-01-01
This paper proposes a new single stage buck-boost DC-AC neutral point clamped inverter topology which integrates the cascaded configurations of recently introduced inductor-capacitor-capacitor-transformer impedance source network (by Adamowicz) and classic NPC configuration. As a consequence......, it has enhanced buck-boost functionality and low output voltage distortions compared to the traditional Z-source inverter; it has continuous input current which reduces the source stress and inverter noise; it also contains two built-in capacitors which can block the DC current in the transformer...... windings thus preventing the core from saturation; lowers the voltage stresses and power losses of inverter switches and reduces the sizes of filtering devices and as well as obtains better output performance compared to the original two-level Z-source inverters. A phase disposition pulse width modulation...
State-Trajectory Analysis and Control of LLC Resonant Converters
Feng, Weiyi
2013-01-01
With the fast development of communication systems, computers and consumer electronics, the power supplies for telecoms, servers, desktops, laptops, flat-panel TVs, LED lighting, etc. are required for more power delivery with smaller spaces. The LLC resonant converter has been widely adopted for these applications due to the advantages in high efficiency, high power density and holdup time operation capability.However, unlike PWM converters, the control of the LLC resonant converter is much m...
CCLIBS: The CERN Power Converter Control Libraries
AUTHOR|(SzGeCERN)404953; Lebioda, Krzysztof Tomasz; Magrans De Abril, Marc; Martino, Michele; Murillo Garcia, Raul; Nicoletti, Achille
2015-01-01
Accurate control of power converters is a vital activity in large physics projects. Several different control scenarios may coexist, including regulation of a circuit’s voltage, current, or field strength within a magnet. Depending on the type of facility, a circuit’s reference value may be changed asynchronously or synchronously with other circuits. Synchronous changes may be on demand or under the control of a cyclic timing system. In other cases, the reference may be calculated in real-time by an outer regulation loop of some other quantity, such as the tune of the beam in a synchrotron. The power stage may be unipolar or bipolar in voltage and current. If it is unipolar in current, it may be used with a polarity switch. Depending on the design, the power stage may be controlled by a firing angle or PWM duty-cycle reference, or a voltage or current reference. All these cases are supported by the CERN Converter Control Libraries (CCLIBS). These open-source C libraries include advanced reference generati...
State trajectories used to observe and control dc-to-dc converters
Burns, W. W., III; Wilson, T. G.
1976-01-01
State-plane analysis techniques are employed to study the voltage stepup energy-storage dc-to-dc converter. Within this framework, an example converter operating under the influence of a constant on-time and a constant frequency controller is examined. Qualitative insight gained through this approach is used to develop a conceptual free-running control law for the voltage stepup converter which can achieve steady-state operation in one on/off cycle of control. Digital computer simulation data are presented to illustrate and verify the theoretical discussions presented.
Model predictive control for Z-source power converter
DEFF Research Database (Denmark)
Mo, W.; Loh, P.C.; Blaabjerg, Frede
2011-01-01
This paper presents Model Predictive Control (MPC) of impedance-source (commonly known as Z-source) power converter. Output voltage control and current control for Z-source inverter are analyzed and simulated. With MPC's ability of multi- system variables regulation, load current and voltage...
Experimental Learning of Digital Power Controller for Photovoltaic Module Using Proteus VSM
Directory of Open Access Journals (Sweden)
Abhijit V. Padgavhankar
2014-01-01
Full Text Available The electric power supplied by photovoltaic module depends on light intensity and temperature. It is necessary to control the operating point to draw the maximum power of photovoltaic module. This paper presents the design and implementation of digital power converters using Proteus software. Its aim is to enhance student’s learning for virtual system modeling and to simulate in software for PIC microcontroller along with the hardware design. The buck and boost converters are designed to interface with the renewable energy source that is PV module. PIC microcontroller is used as a digital controller, which senses the PV electric signal for maximum power using sensors and output voltage of the dc-dc converter and according to that switching pulse is generated for the switching of MOSFET. The implementation of proposed system is based on learning platform of Proteus virtual system modeling (VSM and the experimental results are presented.
Coconut milk - citrate as extender for West African dwarf buck ...
African Journals Online (AJOL)
JTEkanem
healthy buck certified free of obvious andrological defects. Eight trials of .... EE probe was lubricated with VaselineR before insertion into the ... A descriptive analysis was performed by calculating ..... assistance of Mr. P. I. Odili, laboratory.
Analytical Model for LLC Resonant Converter With Variable Duty-Cycle Control
DEFF Research Database (Denmark)
Shen, Yanfeng; Wang, Huai; Blaabjerg, Frede
2016-01-01
are identified and discussed. The proposed model enables a better understanding of the operation characteristics and fast parameter design of the LLC converter, which otherwise cannot be achieved by the existing simulation based methods and numerical models. The results obtained from the proposed model......In LLC resonant converters, the variable duty-cycle control is usually combined with a variable frequency control to widen the gain range, improve the light-load efficiency, or suppress the inrush current during start-up. However, a proper analytical model for the variable duty-cycle controlled LLC...... converter is still not available due to the complexity of operation modes and the nonlinearity of steady-state equations. This paper makes the efforts to develop an analytical model for the LLC converter with variable duty-cycle control. All possible operation models and critical operation characteristics...
Direct Torque Control of Matrix Converter Fed Induction Motor Drive
Directory of Open Access Journals (Sweden)
JAGADEESAN Karpagam
2011-10-01
Full Text Available This paper presents the Direct TorqueControl (DTC of induction motor drive using matrixconverters. DTC is a high performance motor controlscheme with fast torque and flux responses. However,the main disadvantage of conventional DTC iselectromagnetic torque ripple. In this paper, directtorque control for Induction Motors using MatrixConverters is analysed and points out the problem ofthe electromagnetic torque ripple which is one of themost important drawbacks of the Direct TorqueControl. Besides, the matrix converter is a single-stageac-ac power conversion device without dc-link energystorage elements. Matrix converter (MC may becomea good alternative to voltage-source inverter (VSI.This work combines the advantages of the matrixconverter with those of the DTC technique, generatingthe required voltage vectors under unity input powerfactor operation. Simulation results demonstrates theeffectiveness of the torque control.
Design of a high efficiency 30 kW boost composite converter
Energy Technology Data Exchange (ETDEWEB)
Kim, Hyeokjin [Univ. of Colorado, Boulder, CO (United States); Chen, Hua [Univ. of Colorado, Boulder, CO (United States); Maksimovic, Dragan [Univ. of Colorado, Boulder, CO (United States); Erickson, Robert W. [Univ. of Colorado, Boulder, CO (United States)
2015-09-20
An experimental 30 kW boost composite converter is described in this paper. The composite converter architecture, which consists of a buck module, a boost module, and a dual active bridge module that operates as a DC transformer (DCX), leads to substantial reductions in losses at partial power points, and to significant improvements in weighted efficiency in applications that require wide variations in power and conversion ratio. A comprehensive loss model is developed, accounting for semiconductor conduction and switching losses, capacitor losses, as well as dc and ac losses in magnetic components. Based on the developed loss model, the module and system designs are optimized to maximize efficiency at a 50% power point. Experimental results for the 30 kW prototype demonstrate 98.5%peak efficiency, very high efficiency over wide ranges of power and voltage conversion ratios, as well as excellent agreements between model predictions and measured efficiency curves.
submitter Test strategies for industrial testers for converter controls equipment
Oleniuk, P; Kasampalis, V; Nisbet, D; Todd, B; Uznański, S
2017-01-01
Power converters and their controls electronics are key elements for the operation of the CERN accelerator complex, having a direct impact on its availability. To prevent early-life failures and provide means to verify electronics, a set of industrial testers is used throughout the converters controls electronics' life cycle. The roles of the testers are to validate mass production during the manufacturing phase and to provide means to diagnose and repair failed modules that are brought back from operation. In the converter controls electronics section of the power converters group in the technology department of CERN (TE/EPC/CCE), two main test platforms have been adopted: a PXI platform for mixed analogue-digital functional tests and a JTAG Boundary-Scan platform for digital interconnection and functional tests. Depending on the functionality of the device under test, the appropriate test platforms are chosen. This paper is a follow-up to results presented at the TWEPP 2015 conference, adding the boundary s...
Analysis of a PWM Resonant Buck Chopper for Use as a Ship Service Converter Module
National Research Council Canada - National Science Library
Ciezki, John
1999-01-01
.... This study provides a background analysis into resonant converters which utilize zero-voltage-switching and zero-current-switching techniques to mitigate the aforementioned concerns and facilitate...
Rivas-Muñoz, Raymundo; Carrillo, Evaristo; Rodriguez-Martinez, Rafael; Leyva, Carlos; Mellado, Miguel; Véliz, Francisco Gerardo
2010-08-01
The effects of body condition score of does and exposure to sexually active bucks after exposure to long-day artificial photoperiod were examined in mature anovulatory French Alpine goat in Northern Mexico. In June, goats in good (2.3 +/- 0.2, scale 1 to 4; n = 10) or poor (1.6 +/- 0.3; n = 10) body condition were exposed during 15 day to sexually active bucks, which had been exposed to long photoperiod (16:8-h light-dark cycle, starting in December). A third group of goats in good body condition was exposed to bucks kept under the natural photoperiod of this region (26 degrees N). All goats in good body condition exposed to bucks treated with prolonged photoperiod exhibited estrus behavior, whereas only 50% of the does in poor body condition showed estrous behavior during the 15-day buck exposure. None of the does in good body condition showed estrus when exposed to bucks under natural photoperiod. These results revealed that a good body condition is required for maximum estrus response in anestrous Alpine goats and that exposure of bucks to long photoperiod in winter is essential for an adequate stimulus to reestablish estrus cycles in anovulatory Alpine does in Northern Mexico.
An improved control scheme based in droop characteristic for microgrid converters
Energy Technology Data Exchange (ETDEWEB)
Arboleya, P.; Diaz, D.; Guerrero, J.M.; Garcia, P.; Briz, F.; Gonzalez-Moran, C.; Gomez Aleixandre, J. [University of Oviedo, Electrical Engineering Department, 33204 Gijon, Asturias (Spain)
2010-10-15
In the present work, an improved version of the conventional-droop control for microgrid converter is presented. The modifications added to the control are based on a feed-forward current control that allows the converter to work in several modes, both when it is grid connected or in island. The use of this control represents the main contribution of this paper, permitting the inverter to work as a grid supporting source or ancillary services provider when it works grid connected. In this mode the converter varies the injected active and reactive power with the variation of voltage module and frequency using the same main control loop as when it is working in island mode. (author)
Directory of Open Access Journals (Sweden)
Rui Li
2016-12-01
Full Text Available The AC voltage control of a DC/DC converter based on the modular multilevel converter (MMC is considered under normal operation and during a local DC fault. By actively setting the AC voltage according to the two DC voltages of the DC/DC converter, the modulation index can be near unity, and the DC voltage is effectively utilized to output higher AC voltage. This significantly decreases submodule (SM capacitance and conduction losses of the DC/DC converter, yielding reduced capital cost, volume, and higher efficiency. Additionally, the AC voltage is limited in the controllable range of both the MMCs in the DC/DC converter; thus, over-modulation and uncontrolled currents are actively avoided. The AC voltage control of the DC/DC converter during local DC faults, i.e., standby operation, is also proposed, where only the MMC connected on the faulty cable is blocked, while the other MMC remains operational with zero AC voltage output. Thus, the capacitor voltages can be regulated at the rated value and the decrease of the SM capacitor voltages after the blocking of the DC/DC converter is avoided. Moreover, the fault can still be isolated as quickly as the conventional approach, where both MMCs are blocked and the DC/DC converter is not exposed to the risk of overcurrent. The proposed AC voltage control strategy is assessed in a three-terminal high-voltage direct current (HVDC system incorporating a DC/DC converter, and the simulation results confirm its feasibility.
Analysis and Design of Embedded Controlled Parallel Resonant Converter
Directory of Open Access Journals (Sweden)
P. CHANDRASEKHAR
2009-07-01
Full Text Available Microcontroller based constant frequency controlled full bridge LC parallel resonant converter is presented in this paper for electrolyser application. An electrolyser is a part of renewable energy system which generates hydrogen from water electrolysis. The DC power required by the electrolyser system is supplied by the DC-DC converter. Owing to operation under constant frequency, the filter designs are simplified and utilization of magnetic components is improved. This converter has advantages like high power density, low EMI and reduced switching stresses. DC-DC converter system is simulated using MATLAB, Simulink. Detailed simulation results are presented. The simulation results are compared with the experimental results.
Study on the Control Algorithm of Two-Stage DC-DC Converter for Electric Vehicles
Directory of Open Access Journals (Sweden)
Changhao Piao
2014-01-01
Full Text Available The fast response, high efficiency, and good reliability are very important characteristics to electric vehicles (EVs dc/dc converters. Two-stage dc-dc converter is a kind of dc-dc topologies that can offer those characteristics to EVs. Presently, nonlinear control is an active area of research in the field of the control algorithm of dc-dc converters. However, very few papers research on two-stage converter for EVs. In this paper, a fixed switching frequency sliding mode (FSFSM controller and double-integral sliding mode (DISM controller for two-stage dc-dc converter are proposed. And a conventional linear control (lag is chosen as the comparison. The performances of the proposed FSFSM controller are compared with those obtained by the lag controller. In consequence, the satisfactory simulation and experiment results show that the FSFSM controller is capable of offering good large-signal operations with fast dynamical responses to the converter. At last, some other simulation results are presented to prove that the DISM controller is a promising method for the converter to eliminate the steady-state error.
Stochastic control of inertial sea wave energy converter.
Raffero, Mattia; Martini, Michele; Passione, Biagio; Mattiazzo, Giuliana; Giorcelli, Ermanno; Bracco, Giovanni
2015-01-01
The ISWEC (inertial sea wave energy converter) is presented, its control problems are stated, and an optimal control strategy is introduced. As the aim of the device is energy conversion, the mean absorbed power by ISWEC is calculated for a plane 2D irregular sea state. The response of the WEC (wave energy converter) is driven by the sea-surface elevation, which is modeled by a stationary and homogeneous zero mean Gaussian stochastic process. System equations are linearized thus simplifying the numerical model of the device. The resulting response is obtained as the output of the coupled mechanic-hydrodynamic model of the device. A stochastic suboptimal controller, derived from optimal control theory, is defined and applied to ISWEC. Results of this approach have been compared with the ones obtained with a linear spring-damper controller, highlighting the capability to obtain a higher value of mean extracted power despite higher power peaks.
Outphasing control of gallium nitride based very high frequency resonant converters
DEFF Research Database (Denmark)
Madsen, Mickey Pierre; Knott, Arnold; Andersen, Michael A. E.
2015-01-01
In this paper an outphasing modulation control method suitable for line regulation of very high frequency resonant converters is described. The pros and cons of several control methods suitable for very high frequency resonant converters are described and compared to outphasing modulation...
Digitally Controlled Offline Converter with Galvanic Isolation Based on an 8-bit Microcontroller
DEFF Research Database (Denmark)
Jakobsen, Lars Tønnes; Andersen, Michael Andreas E.
2007-01-01
This paper presents an offline AC/DC converter with digital control and galvanic isolation that can be implemented using cheap commercially available components. An ATMEL ATTiny26 8-bit microcontroller is used to control the converter. The microcontroller is placed on the secondary side of the co......This paper presents an offline AC/DC converter with digital control and galvanic isolation that can be implemented using cheap commercially available components. An ATMEL ATTiny26 8-bit microcontroller is used to control the converter. The microcontroller is placed on the secondary side...
Power electronic converters PWM strategies and current control techniques
Monmasson, Eric
2013-01-01
A voltage converter changes the voltage of an electrical power source and is usually combined with other components to create a power supply. This title is devoted to the control of static converters, which deals with pulse-width modulation (PWM) techniques, and also discusses methods for current control. Various application cases are treated. The book is ideal for professionals in power engineering, power electronics, and electric drives industries, as well as practicing engineers, university professors, postdoctoral fellows, and graduate students.
Wind Turbine Converter Control Interaction with Complex Wind Farm Systems
DEFF Research Database (Denmark)
Kocewiak, Lukasz Hubert; Hjerrild, Jesper; Bak, Claus Leth
2013-01-01
. The same wind turbine converter control strategy is evaluated in two different wind farms. It is emphasised that the grid-side converter controller should be characterised by sufficient harmonic/noise rejection and adjusted depending on wind farms to which it is connected. Various stability indices......This study presents wind turbine converter stability analysis of wind farms in frequency domain. The interaction between the wind turbine control system and the wind farm structure in wind farms is deeply investigated. Two wind farms (i.e. Horns Rev II and Karnice) are taken into consideration...... in this study. It is shown that wind farm components, such as long high-voltage alternating current cables and park transformers, can introduce significant low-frequency series resonances seen from the wind turbine terminals that can affect wind turbine control system operation and overall wind farm stability...
Control analysis and experimental verification of a practical dc–dc boost converter
Directory of Open Access Journals (Sweden)
Saswati Swapna Dash
2015-12-01
Full Text Available This paper presents detailed open loop and closed loop analysis on boost dc–dc converter for both voltage mode control and current mode control. Here the boost dc–dc converter is a practical converter considering all possible parasitic elements like ESR and on state voltage drops. The open loop control, closed loop current mode control and voltage mode control are verified. The comparative study of all control techniques is presented. The PI compensator for closed loop current mode control is designed using these classical techniques like root locus technique and bode diagram. The simulation results are validated with the experimental results of voltage mode control for both open loop and closed loop control.
Test strategies for industrial testers for converter controls equipment
International Nuclear Information System (INIS)
Oleniuk, P.; Kasampalis, V.; Cosmo, M. Di; Nisbet, D.; Todd, B.; Uznański, S.
2017-01-01
Power converters and their controls electronics are key elements for the operation of the CERN accelerator complex, having a direct impact on its availability. To prevent early-life failures and provide means to verify electronics, a set of industrial testers is used throughout the converters controls electronics' life cycle. The roles of the testers are to validate mass production during the manufacturing phase and to provide means to diagnose and repair failed modules that are brought back from operation. In the converter controls electronics section of the power converters group in the technology department of CERN (TE/EPC/CCE), two main test platforms have been adopted: a PXI platform for mixed analogue-digital functional tests and a JTAG Boundary-Scan platform for digital interconnection and functional tests. Depending on the functionality of the device under test, the appropriate test platforms are chosen. This paper is a follow-up to results presented at the TWEPP 2015 conference, adding the boundary scan test platform and the first results from exploitation of the test system. This paper reports on the test software, hardware design and test strategy applied for a number of devices that has resulted in maximizing test coverage and minimizing test design effort.
Model and control of the isolated multi-modular converter
DEFF Research Database (Denmark)
Verdugo, Cristian; Candela, Jose Ignacio; Blaabjerg, Frede
2017-01-01
Multi-modular converters have proven to be one of the most suitable topology to be used in high and power applications. The modularity of these configurations offer several advantages, such as: high quality voltage, redundancy and high efficiency. In these converters, the series connection...... voltages. However, increasing the number of conversion stages, increase also the losses and the implementation costs. In order to overcome these drawbacks, a new configuration of multi-modular converter is proposed in this paper. The proposed converter provides isolation with one conversion stage by means...... of using low frequency transformers in each module. The main principle behind this concept, the control structure and simulation results are presented to validate the proposed configuration....
Stochastic Control of Inertial Sea Wave Energy Converter
Mattiazzo, Giuliana; Giorcelli, Ermanno
2015-01-01
The ISWEC (inertial sea wave energy converter) is presented, its control problems are stated, and an optimal control strategy is introduced. As the aim of the device is energy conversion, the mean absorbed power by ISWEC is calculated for a plane 2D irregular sea state. The response of the WEC (wave energy converter) is driven by the sea-surface elevation, which is modeled by a stationary and homogeneous zero mean Gaussian stochastic process. System equations are linearized thus simplifying the numerical model of the device. The resulting response is obtained as the output of the coupled mechanic-hydrodynamic model of the device. A stochastic suboptimal controller, derived from optimal control theory, is defined and applied to ISWEC. Results of this approach have been compared with the ones obtained with a linear spring-damper controller, highlighting the capability to obtain a higher value of mean extracted power despite higher power peaks. PMID:25874267
Stochastic Control of Inertial Sea Wave Energy Converter
Directory of Open Access Journals (Sweden)
Mattia Raffero
2015-01-01
Full Text Available The ISWEC (inertial sea wave energy converter is presented, its control problems are stated, and an optimal control strategy is introduced. As the aim of the device is energy conversion, the mean absorbed power by ISWEC is calculated for a plane 2D irregular sea state. The response of the WEC (wave energy converter is driven by the sea-surface elevation, which is modeled by a stationary and homogeneous zero mean Gaussian stochastic process. System equations are linearized thus simplifying the numerical model of the device. The resulting response is obtained as the output of the coupled mechanic-hydrodynamic model of the device. A stochastic suboptimal controller, derived from optimal control theory, is defined and applied to ISWEC. Results of this approach have been compared with the ones obtained with a linear spring-damper controller, highlighting the capability to obtain a higher value of mean extracted power despite higher power peaks.
Nonlinear control of voltage source converters in AC-DC power system.
Dash, P K; Nayak, N
2014-07-01
This paper presents the design of a robust nonlinear controller for a parallel AC-DC power system using a Lyapunov function-based sliding mode control (LYPSMC) strategy. The inputs for the proposed control scheme are the DC voltage and reactive power errors at the converter station and the active and reactive power errors at the inverter station of the voltage-source converter-based high voltage direct current transmission (VSC-HVDC) link. The stability and robust tracking of the system parameters are ensured by applying the Lyapunov direct method. Also the gains of the sliding mode control (SMC) are made adaptive using the stability conditions of the Lyapunov function. The proposed control strategy offers invariant stability to a class of systems having modeling uncertainties due to parameter changes and exogenous inputs. Comprehensive computer simulations are carried out to verify the proposed control scheme under several system disturbances like changes in short-circuit ratio, converter parametric changes, and faults on the converter and inverter buses for single generating system connected to the power grid in a single machine infinite-bus AC-DC network and also for a 3-machine two-area power system. Furthermore, a second order super twisting sliding mode control scheme has been presented in this paper that provides a higher degree of nonlinearity than the LYPSMC and damps faster the converter and inverter voltage and power oscillations. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.
A control strategy for multi-functional converter to improve grid power quality
DEFF Research Database (Denmark)
Li, Fei; Wang, Xiongfei; Chen, Zhe
2011-01-01
The extensive use of converter-interfacing distributed energy resources (DER), combined with a large amount of nonlinear and unbalanced loads connected to the distribution power system, has led to power quality problem. This paper proposes a control strategy for a three-phase four-leg multi-funct......) for multi-functional converter is described. Simulation and hardware in the loop real time test results carried on a three-phase four-wire distributed generation system illustrate the effectiveness of the proposed control strategy.......The extensive use of converter-interfacing distributed energy resources (DER), combined with a large amount of nonlinear and unbalanced loads connected to the distribution power system, has led to power quality problem. This paper proposes a control strategy for a three-phase four-leg multi......-functional converter which can compensate reactive power, harmonic currents, unbalance, and neutral current simultaneously under distorted voltage conditions, besides the active power exchange. The capacity of the converter is taken into account. The proposed control strategy based on synchronous reference frame (SRF...
Improvement of burst-mode control of piezoelectric transformer based DC/DC converter
International Nuclear Information System (INIS)
Vasic, Dejan; Liu, Yuan-Ping; Costa, François; Schwander, Denis; Wu, Wen-Jong
2013-01-01
Burst-mode operation is adopted sometimes in piezoelectric transformer based converters for two major purposes: (1) to achieve voltage regulation in DC/DC converters and (2) to achieve dimming control in backlight inverters. Burst-mode control enables the converter to operate at a constant switching frequency as well as to maintain good efficiency at light load conditions. However, in practice, the piezoelectric transformer cannot instantly stop vibrating in the burst-mode due to its high quality factor. The delay in the output voltage change resulting from this behavior influences the accuracy of the regulation. This paper proposes a control strategy to make the piezoelectric transformer stop more quickly so as to enhance the accuracy of burst-mode control. The proposed method only modifies the control signal of the burst-mode driving circuit. The proposed control strategy is verified by experiments in a step-down 9 W DC/DC converter. (paper)
Utilization of Nonlinear Converters for Audio Amplification
DEFF Research Database (Denmark)
Iversen, Niels; Birch, Thomas; Knott, Arnold
2012-01-01
Class D ampliers ts the automotive demands quite well. The traditional buck-based amplier has reduced both the cost and size of ampliers. However the buck topology is not without its limitations. The maximum peak AC output voltage produced by the power stage is only equal the supply voltage...
Zubair, M; Ahmad, M; Jamil, H; Deeba, F
2016-12-01
The present environmental study has been planned to investigate the toxic effects of arsenic on reproductive functions of Teddy bucks as well as to examine whether these toxic effects are ameliorated by vitamin E. Sixteen adult Teddy bucks were divided randomly into four equal groups A, B, C and D with following treatment: A (control), B (sodium arsenite 5 mg kg -1 BW day -1 ), C (vit E 200 mg kg -1 BW day -1 + Arsenic 5 mg kg -1 BW day -1 ) and D (vit E 200 mg kg -1 BW day -1 ). This treatment was continued for 84 days. Semen quality parameters were evaluated weekly. Male testosterone, luteinising hormone (LH), follicle-stimulating hormone (FSH) and cortisol levels were measured through enzyme-linked immunosorbent assay (ELISA) after every 2 weeks. The data were subjected to two-way analysis of variance followed by Duncan test for multiple comparisons. Semen evaluation parameters were reduced significantly (P semen and hormonal parameters. It may be concluded from this study that sodium arsenite causes major toxicity changes in semen and hormonal profile in Teddy goat bucks and vitamin E has ameliorative effects on these toxic changes. © 2016 Blackwell Verlag GmbH.
A Review on Direct Power Control for Applications to Grid Connected PWM Converters
Directory of Open Access Journals (Sweden)
T. A. Trivedi
2015-08-01
Full Text Available The Direct Power Control strategy has become popular as an alternative to the conventional vector oriented control strategy for grid connected PWM converters. In this paper, Direct Power Control as applied to various applications of grid connected converters is reviewed. The Direct Power Control for PWM rectifiers, Grid Connected DC/AC inverters applications such as renewable energy sources interface, Active Power Filters, Doubly Fed Induction Generators and AC-DC-AC converters are discussed. Control strategies such as Look-Up table based control, predictive control, Virtual Flux DPC, Model based DPC and DPC-Space Vector Modulation are critically reviewed. The effects of various key parameters such as selection of switching vector, sampling time, hysteresis band and grid interfacing on performance of direct power controlled converters are presented.
Implementation of Maximum Power Point Tracking (MPPT) Solar Charge Controller using Arduino
Abdelilah, B.; Mouna, A.; KouiderM’Sirdi, N.; El Hossain, A.
2018-05-01
the platform Arduino with a number of sensors standard can be used as components of an electronic system for acquiring measures and controls. This paper presents the design of a low-cost and effective solar charge controller. This system includes several elements such as the solar panel converter DC/DC, battery, circuit MPPT using Microcontroller, sensors, and the MPPT algorithm. The MPPT (Maximum Power Point Tracker) algorithm has been implemented using an Arduino Nano with the preferred program. The voltage and current of the Panel are taken where the program implemented will work and using this algorithm that MPP will be reached. This paper provides details on the solar charge control device at the maximum power point. The results include the change of the duty cycle with the change in load and thus mean the variation of the buck converter output voltage and current controlled by the MPPT algorithm.
PSO based PI controller design for a solar charger system.
Yau, Her-Terng; Lin, Chih-Jer; Liang, Qin-Cheng
2013-01-01
Due to global energy crisis and severe environmental pollution, the photovoltaic (PV) system has become one of the most important renewable energy sources. Many previous studies on solar charger integrated system only focus on load charge control or switching Maximum Power Point Tracking (MPPT) and charge control modes. This study used two-stage system, which allows the overall portable solar energy charging system to implement MPPT and optimal charge control of Li-ion battery simultaneously. First, this study designs a DC/DC boost converter of solar power generation, which uses variable step size incremental conductance method (VSINC) to enable the solar cell to track the maximum power point at any time. The voltage was exported from the DC/DC boost converter to the DC/DC buck converter, so that the voltage dropped to proper voltage for charging the battery. The charging system uses constant current/constant voltage (CC/CV) method to charge the lithium battery. In order to obtain the optimum PI charge controller parameters, this study used intelligent algorithm to determine the optimum parameters. According to the simulation and experimental results, the control parameters resulted from PSO have better performance than genetic algorithms (GAs).
PSO Based PI Controller Design for a Solar Charger System
Directory of Open Access Journals (Sweden)
Her-Terng Yau
2013-01-01
Full Text Available Due to global energy crisis and severe environmental pollution, the photovoltaic (PV system has become one of the most important renewable energy sources. Many previous studies on solar charger integrated system only focus on load charge control or switching Maximum Power Point Tracking (MPPT and charge control modes. This study used two-stage system, which allows the overall portable solar energy charging system to implement MPPT and optimal charge control of Li-ion battery simultaneously. First, this study designs a DC/DC boost converter of solar power generation, which uses variable step size incremental conductance method (VSINC to enable the solar cell to track the maximum power point at any time. The voltage was exported from the DC/DC boost converter to the DC/DC buck converter, so that the voltage dropped to proper voltage for charging the battery. The charging system uses constant current/constant voltage (CC/CV method to charge the lithium battery. In order to obtain the optimum PI charge controller parameters, this study used intelligent algorithm to determine the optimum parameters. According to the simulation and experimental results, the control parameters resulted from PSO have better performance than genetic algorithms (GAs.
Digital Fuzzy logic and PI control of phase-shifted full-bridge current-doubler converter
DEFF Research Database (Denmark)
Török, Lajos; Munk-Nielsen, Stig
2011-01-01
Simple digital fuzzy logic voltage control of a phaseshifted full-bridge (PSFB) converter is proposed in this article. A comparison of the fuzzy controller and the classical PI voltage controller is presented and their effects on the converter dynamics are analyzed. Simulation model of the conver...... of the converter was built in Matlab/Simulink using PLECS. A 600W PSFB convert was designed and built and the control strategies were implemented in a 16 bit fixed point dsPIC microcontroller. The advantages and disadvantages of using Fuzzy logic control are highlighted....
Power Controllability of Three-phase Converter with Unbalanced AC Source
DEFF Research Database (Denmark)
Ma, Ke; Chen, Wenjie; Liserre, Marco
2015-01-01
Three-phase DC-AC power converters suffer from power oscillation and overcurrent problems in case of unbalanced AC source voltage that can be caused by grid/generator faults. Existing solutions to handle these problems are properly selecting and controlling the positive and negative sequence...... currents. In this work a new series of control strategies which utilize the zerosequence components are proposed to enhance the power control ability under this adverse condition. It is concluded that by introducing proper zero sequence current controls and corresponding circuit configurations, the power...... converter can enable more flexible control targets, achieving better performances in the delivered power and load current when suffering from unbalanced AC voltage....
A control strategy for PV stand-alone applications
International Nuclear Information System (INIS)
Slouma, S; Baccar, H
2015-01-01
This paper proposes a stand-alone photovoltaic (PV) system study in domestic applications. Because of the decrease in power of photovoltaic module as a consequence of changes in solar radiation and temperature which affect the photovoltaic module performance, the design and control of DC-DC buck converter was proposed for providing power to the load from a photovoltaic source.In fact, the control of this converter is carried out with integrated MPPT (Maximum Power Point Tracking) algorithm which ensures a maximum energy generated by the PV arrays. Moreover, the output stage is composed by a battery energy storage system, dc-ac inverter, LCL filter which enables higher efficiency, low distortion ac waveforms and low leakage currents. The control strategy adopted is cascade control composed by two regulation loops.Simulations performed with PSIM software were able to validate the control system.The realization and testing of the photovoltaic system were achieved in the Photovoltaic laboratory of the Centre for Research and Energy Technologies at the Technopark Borj Cedria. Experimental results verify the effeciency of the proposed system
A control strategy for PV stand-alone applications
Slouma, S.; Baccar, H.
2015-04-01
This paper proposes a stand-alone photovoltaic (PV) system study in domestic applications. Because of the decrease in power of photovoltaic module as a consequence of changes in solar radiation and temperature which affect the photovoltaic module performance, the design and control of DC-DC buck converter was proposed for providing power to the load from a photovoltaic source.In fact, the control of this converter is carried out with integrated MPPT (Maximum Power Point Tracking) algorithm which ensures a maximum energy generated by the PV arrays. Moreover, the output stage is composed by a battery energy storage system, dc-ac inverter, LCL filter which enables higher efficiency, low distortion ac waveforms and low leakage currents. The control strategy adopted is cascade control composed by two regulation loops.Simulations performed with PSIM software were able to validate the control system.The realization and testing of the photovoltaic system were achieved in the Photovoltaic laboratory of the Centre for Research and Energy Technologies at the Technopark Borj Cedria. Experimental results verify the effeciency of the proposed system.
Current Mode Control for LLC Series Resonant DC-to-DC Converters
Jinhaeng Jang; Syam Kumar Pidaparthy; Byungcho Choi
2015-01-01
Conventional voltage mode control only offers limited performance for LLC series resonant DC-to-DC converters experiencing wide variations in operational conditions. When the existing voltage mode control is employed, the closed-loop performance of the converter is directly affected by unavoidable changes in power stage dynamics. Thus, a specific control design optimized at one particular operating point could become unacceptable when the operational condition is varied. This paper presents a...
New Approaches to Circulating Current Controllers for Modular Multilevel Converters
Directory of Open Access Journals (Sweden)
Miguel Moranchel
2017-01-01
Full Text Available In the next years, modular multilevel converters (MMCs are going to be a next generation multilevel converters for medium to high voltage conversion applications, such as medium voltage motor drives, medium voltage flexible AC transmission systems (FACTS and high voltage direct current transmission. They provide advantages such as high modularity, availability, low generation of harmonics, etc. However, the circulating current distorts the leg currents and increases the rated current of power devices, which further increases system cost. This paper focuses on analysis and suppression of these currents in a MMC using two algorithms for tracking of harmonics. For this work resonant controllers and repetitive controllers have been selected. Both controllers are analyzed and simulations results are presented. Moreover, the controllers have been tested and validated for a three phase MMC operating as an inverter using a real processing platform based on Zynq by Xilinx and designed to control large multilevel converters and in a real MMC prototype. These results are provided to demonstrate the feasibility of the proposed method.
A Self-Oscillating Control Scheme for a Boost Converter Providing a Controlled Output Current
DEFF Research Database (Denmark)
Knott, Arnold; Pfaffinger, Gerhard R.; Andersen, Michael A. E.
2011-01-01
Most switched mode power supplies provide a regulated voltage at their output. However, there are applications requiring a controlled current. Among others are battery chargers, test equipment for converters driven by solar cells, and LED drivers. This paper describes a dc–dc power converter real...
A DSP controlled one-to-three phase matrix converter
Energy Technology Data Exchange (ETDEWEB)
Dubovsky, J.; Dobrucly, B; Tabacek, R.; Havrila, R. [Department of Electric Traction and Energetics Faculty of Electrical Engineering, University of Zilina (Slovakia)
1997-12-31
This paper deals with the theoretical analysis computer simulation and experimental results of IM fed by a one-to-three phase matrix converter which offers a unique solution for single phase electric traction applications. The proposed drive in comparison with currently used conventional drives reduces the number of power switching elements of the converter, which increases drives dependability and brings lower investment in power electronics used in drive. Further advantage is that the converter is controlled with nearly unity power factor which cuts down the operational expenses and offers higher overall performance of the drive. (orig.) 6 refs.
Análisis de la estabilidad de un convertidor buck multicelular de dos celdas
Directory of Open Access Journals (Sweden)
Julián Pelaéz
2014-12-01
Full Text Available En este trabajo se presenta un convertidor multicelular con dos células bajo un modo de modulación (PWM de control de voltaje por ancho de pulso. El convertidor buck multicelular obtenido puede ser utilizado como un circuito electrónico de potencia para aplicaciones de alta tensión; donde los dispositivos semiconductores tienen la capacidad de cambiar solo a niveles de bajo voltaje. El análisis de estabilidad se ha hecho para un control puramente proporcional y más tarde, se ha extendido para un control Proporcional-Integral (PI. Los resultados de la simulación demuestran la validez del análisis.
Conventional control and fuzzy control of a dc-dc converter for machine drive
Energy Technology Data Exchange (ETDEWEB)
Radoi, C.; Florescu, A. [Department of Power Electronics `Politecnica` University Bucharest (Romania)
1997-12-31
Fuzzy logic or fuzzy set theory is recently getting increasing emphasis in process control applications. The paper describes an application of fuzzy logic in speed control system that uses a dc-dc converter. The fuzzy control is used to linearize the family of external characteristics of the converter in discontinuous-conduction mode occurring at light load and/or high speed. In order to compare the conventional control with the fuzzy logic control, algorithms have been developed in detail and verified by Microsoft Excel simulation. The simulation study indicates that fuzzy control is a good alternative for conventional control methods, being used particularly in non-linear complex systems ill defined or totally unknown. Where the mathematical model exists, it is useful. The applications of fuzzy set theory in power electronics are almost entirely new; fuzzy logic seems to have a lot of premises in the large industrial control field. (orig.) 2 refs.
Reproductive Parameters of the West African Dwarf Bucks Raised in ...
African Journals Online (AJOL)
Reproductive samples (scrotal circumference, testicular density, scrotal weight, left and right testicular weights, left and right tunica weights, left and right testicular length, left and right caput epididymal weights, left and right corpus epididymal weights, left and right caudal epididymal weights) from the bucks were collected ...
Resonant power converter comprising adaptive dead-time control
DEFF Research Database (Denmark)
2017-01-01
The invention relates in a first aspect to a resonant power converter comprising: a first power supply rail for receipt of a positive DC supply voltage and a second power supply rail for receipt of a negative DC supply voltage. The resonant power converter comprises a resonant network with an input...... terminal for receipt of a resonant input voltage from a driver circuit. The driver circuit is configured for alternatingly pulling the resonant input voltage towards the positive and negative DC supply voltages via first and second semiconductor switches, respectively, separated by intervening dead......-time periods in accordance with one or more driver control signals. A dead-time controller is configured to adaptively adjusting the dead-time periods based on the resonant input voltage....
Wireless power charging using point of load controlled high frequency power converters
Miller, John M.; Campbell, Steven L.; Chambon, Paul H.; Seiber, Larry E.; White, Clifford P.
2015-10-13
An apparatus for wirelessly charging a battery of an electric vehicle is provided with a point of load control. The apparatus includes a base unit for generating a direct current (DC) voltage. The base unit is regulated by a power level controller. One or more point of load converters can be connected to the base unit by a conductor, with each point of load converter comprising a control signal generator that transmits a signal to the power level controller. The output power level of the DC voltage provided by the base unit is controlled by power level controller such that the power level is sufficient to power all active load converters when commanded to do so by any of the active controllers, without generating excessive power that may be otherwise wasted.
Power Controllability of Three-phase Converter with Unbalanced AC Source
DEFF Research Database (Denmark)
Ma, Ke; Liserre, Marco; Blaabjerg, Frede
2013-01-01
Three-phase DC-AC power converters suffer from power oscillation and overcurrentt problems in case of unbalanced AC source voltage that can be caused by grid/generator faults. Existing solutions to handle these problems are properly selecting and controlling the positive and negative sequence...... currents. In this work a new series of control strategies which utilize the zero-sequence components are proposed to enhance the power control ability under this adverse conditions. It is concluded that by introducing proper zero sequence current controls and corresponding circuit configurations, the power...... converter can enable more flexible control targets, achieving better performances in the delivered power and load current when suffering from unbalanced AC sources....
Method and device for current driven electric energy conversion
DEFF Research Database (Denmark)
2012-01-01
Device comprising an electric power converter circuit for converting electric energy. The converter circuit comprises a switch arrangement with two or more controllable electric switches connected in a switching configuration and controlled so as to provide a current drive of electric energy from...... configurations such as half bridge buck, full bridge buck, half bridge boost, or full bridge boost. A current driven conversion is advantageous for high efficient energy conversion from current sources such as solar cells or where a voltage source is connected through long cables, e.g. powerline cables for long...... an associated electric source connected to a set of input terminals. This is obtained by the two or more electric swiches being connected and controlled to short-circuit the input terminals during a part of a switching period. Further, a low pass filter with a capacitor and an inductor are provided to low pass...
Power decoupling method for single phase differential buck converter
DEFF Research Database (Denmark)
Yao, Wenli; Tang, Yi; Zhang, Xiaobin
2015-01-01
inverter to improve the dc link power quality, and an improved active power decoupling method is proposed to achieve ripple power reduction for both AC-DC and DC-AC conversions. The ripple energy storage is realized by the filter capacitors, which are connected between the output terminal and the negative...... generation technique is proposed to provide accurate ripple power compensation, and closed-loop controllers are also designed based on small signal models. The effectiveness of this power decoupling method is verified by detailed simulation studies as well as laboratory prototype experimental results....... dc bus. By properly controlling the differential mode voltage of the capacitors, it is possible to transfer desired energy between the DC port and AC port. The common mode voltage is controlled in such a way that the ripple power on the dc side will be reduced. Furthermore, an autonomous reference...
Directory of Open Access Journals (Sweden)
Rathnakannan Kailasam
2008-01-01
Full Text Available This paper describes the modelling and the analysis of control logic for a Nano-Device- based PWM controller. A comprehensive simple SPICE schematic model for Single Electron transistor has been proposed. The operation of basic Single Electron Transistor logic gates and SET flip flops were successfully designed and their performances analyzed. The proposed design for realizing the logic gates and flip-flops is used in constructing the PWM controller utilized for switching the buck converter circuit. The output of the converter circuit is compared with reference voltage, and when the error voltage and the reference are matched the latch is reset so as to generate the PWM signal. Due to the simplicity and accuracy of the compact model, the simulation time and speed are much faster, which makes it potentially applicable in large-scale circuit simulation. This study confirms that the SET-based PWM controller is small in size, consumes ultra low power and operates at high speeds without compromising any performance. In addition these devices are capable of measuring charges of extremely high sensitivity.
Simulation of closed loop controlled boost converter for solar installation
Directory of Open Access Journals (Sweden)
Kalirasu Athimulam
2010-01-01
Full Text Available With the shortage of the energy and ever increasing of the oil price, research on the renewable and green energy sources, especially the solar arrays and the fuel cells, becomes more and more important. How to achieve high stepup and high efficiency DC/DC converters is the major consideration in the renewable power applications due to the low voltage of PV arrays and fuel cells. In this paper digital simulation of closed loop controlled boost converter for solar installation is presented. Circuit models for open loop and closed loop controlled systems are developed using the blocks of simulink. The simulation results are compared with the theoretical results. This converter has advantages like improved power factor, fast response and reduced hardware. .
Utilization of non-linear converters for audio amplification
DEFF Research Database (Denmark)
Iversen, Niels Elkjær; Birch, Thomas; Knott, Arnold
2012-01-01
Class D amplifiers fits the automotive demands quite well. The traditional buck-based amplifier has reduced both the cost and size of amplifiers. However the buck topology is not without its limitations. The maximum peak AC output voltage produced by the power stage is only equal the supply voltage...
High Step-Up DC—DC Converter for AC Photovoltaic Module with MPPT Control
Sundar, Govindasamy; Karthick, Narashiman; Rama Reddy, Sasi
2014-08-01
This paper presents the high gain step-up BOOST converter which is essential to step up the low output voltage from PV panel to the high voltage according to the requirement of the application. In this paper a high gain BOOST converter with coupled inductor technique is proposed with the MPPT control. Without extreme duty ratios and the numerous turns-ratios of a coupled inductor this converter achieves a high step-up voltage-conversion ratio and the leakage energy of the coupled inductor is efficiently recycled to the load. MPPT control used to extract the maximum power from PV panel by controlling the Duty ratio of the converter. The PV panel, BOOST converter and the MPPT are modeled using Sim Power System blocks in MATLAB/SIMULINK environment. The prototype model of the proposed converter has been implemented with the maximum measured efficiency is up to 95.4% and full-load efficiency is 93.1%.
Development of Sliding Mode Controller for a Modified Boost Ćuk Converter Configuration
Directory of Open Access Journals (Sweden)
Sanjeevikumar Padmanaban
2017-09-01
Full Text Available This paper introduces a sliding mode control (SMC-based equivalent control method to a novel high output gain Ćuk converter. An additional inductor and capacitor improves the efficiency and output gain of the classical Ćuk converter. Classical proportional integral (PI controllers are widely used in direct current to direct current (DC-DC converters. However, it is a very challenging task to design a single PI controller operating in different loads and disturbances. An SMC-based equivalent control method which achieves a robust operation in a wide operation range is also proposed. Switching frequency is kept constant in appropriate intervals at different loading and disturbance conditions by implementing a dynamic hysteresis control method. Numerical simulations conducted in MATLAB/Simulink confirm the accuracy of analysis of high output gain modified Ćuk converter. In addition, the proposed equivalent control method is validated in different perturbations to demonstrate robust operation in wide operation range.
Directory of Open Access Journals (Sweden)
Wenzheng Xu
2017-10-01
Full Text Available Phase-shifted converters are practically important to provide high conversion efficiencies through soft-switching techniques. However, the limitation on a resonant inductor current in the converters often leads to a non-fulfillment of the requirement of minimum load current. This paper presents a new power electronics control technique to enable the dual features of bi-directional power flow and an extended load range for soft-switching in phase-shift-controlled DC-DC converters. The proposed technique utilizes two identical full bridge converters and inverters in conjunction with a new control logic for gate-driving signals to facilitate both Zero Current Switching (ZCS and Zero Voltage Switching (ZVS in a single phase-shift-controlled DC-DC converter. The additional ZCS is designed for light load conditions at which the minimum load current cannot be attained. The bi-directional phase-shift-controlled DC-DC converter can implement the function of synchronous rectification. Its fast dynamic response allows for quick energy recovery during the regenerative braking of traction systems in electrified trains.
An Optimized Control for LLC Resonant Converter with Wide Load Range
Xi, Xia; Qian, Qinsong
2017-05-01
This paper presents an optimized control which makes LLC resonant converters operate with a wider load range and provides good closed-loop performance. The proposed control employs two paralleled digital compensations to guarantee the good closed-loop performance in a wide load range during the steady state, an optimized trajectory control will take over to change the gate-driving signals immediately at the load transients. Finally, the proposed control has been implemented and tested on a 150W 200kHz 400V/24V LLC resonant converter and the result validates the proposed method.
Wennyta
2015-01-01
This research is conducted to show that woman not always passive, weak or inferior side, but she can use her inferiority (from patriarchal point of view) as a tricky strategy to get the equality between men and women. It is described in Imperial Woman, where Yehonala succeeds in arranging many strategies inside the oppression from patriarchal system. In collecting the data, the writer conducts a library research. A novel by Pearl S. Buck, entitled Imperial Woman and also the biography of Buck...
Directory of Open Access Journals (Sweden)
Gimara Rajapakse
2017-10-01
Full Text Available Despite the predictability and availability at large scale, wave energy conversion (WEC has still not become a mainstream renewable energy technology. One of the main reasons is the large variations in the extracted power which could lead to instabilities in the power grid. In addition, maintaining the speed of the turbine within optimal range under changing wave conditions is another control challenge, especially in oscillating water column (OWC type WEC systems. As a solution to the first issue, this paper proposes the direct connection of a battery bank into the dc-link of the back-to-back power converter system, thereby smoothening the power delivered to the grid. For the second issue, model predictive controllers (MPCs are developed for the rectifier and the inverter of the back-to-back converter system aiming to maintain the turbine speed within its optimum range. In addition, MPC controllers are designed to control the battery current as well, in both charging and discharging conditions. Operations of the proposed battery direct integration scheme and control solutions are verified through computer simulations. Simulation results show that the proposed integrated energy storage and control solutions are capable of delivering smooth power to the grid while maintaining the turbine speed within its optimum range under varying wave conditions.
Asano, Hiroki; Hirose, Tetsuya; Kojima, Yuta; Kuroki, Nobutaka; Numa, Masahiro
2018-04-01
In this paper, we present a wide-load-range switched-capacitor DC-DC buck converter with an adaptive bias comparator for ultra-low-power power management integrated circuit. The proposed converter is based on a conventional one and modified to operate in a wide load range by developing a load current monitor used in an adaptive bias comparator. Measurement results demonstrated that our proposed converter generates a 1.0 V output voltage from a 3.0 V input voltage at a load of up to 100 µA, which is 20 times higher than that of the conventional one. The power conversion efficiency was higher than 60% in the load range from 0.8 to 100 µA.
Current Control of Grid Converters Connected with Series AC Capacitor
DEFF Research Database (Denmark)
Wang, Xiongfei; Blaabjerg, Frede; Loh, Poh Chiang
2015-01-01
The series ac capacitor has recently been used with the transformerless grid-connected converters in the distribution power grids. The capacitive characteristic of the resulting series LC filter restricts the use of conventional synchronous integral or stationary resonant current controllers. Thus...... this paper proposes a fourth-order resonant controller in the stationary frame, which guarantees a zero steady-state current tracking error for the grid converters with series LC filter. This method is then implemented in a three-phase experimental system for verification, where the current harmonics below...... the LC filter resonance frequency are effectively eliminated. Experimental results confirm the validity of the proposed current control scheme....
Protection of semiconductor converters for controlled bypass reactors
International Nuclear Information System (INIS)
Dolgopolov, A. G.; Akhmetzhanov, N. G.; Karmanov, V. F.
2010-01-01
Possible ways of protecting thyristor converters in systems for magnetizing 110 - 500 kV controlled bypass reactors during switching and automatic reclosing are examined based on experience with the development of equipment, line tests, and mathematical modelling.
New non-linear control strategy for non-isolated DC/DC converter with high voltage ratio
Energy Technology Data Exchange (ETDEWEB)
Shahin, A.; Huang, B.; Martin, J.P.; Pierfederici, S.; Davat, B. [Groupe de Recherche en Electronique et en Electrotechnique de Nancy - INPL - Nancy Universite, 2, Avenue de la Foret de Haye, 54516 Vandoeuvre-les-Nancy Cedex (France)
2010-01-15
In this paper, a non-isolated DC/DC converter with high voltage ratio is proposed to allow the interface between a low voltage power source like fuel cell and a high voltage DC bus. To take into account the low voltage-high density characteristics of power sources, a cascaded structure composed of two sub-converters has been chosen and allows obtaining a high voltage ratio. The choice of each sub-converter is based on the requirements of the source and its performances. Consequently, we have chosen a three-interleaved boost converter as the 1st sub-converter whereas the 2nd sub-converter is a three-level boost converter. The control of the whole system is realized thanks to energetic trajectories planning based on flatness properties of the system. The control of both the current and the balance of voltage across the output serial capacitors of the three-level boost converter is ensured by non-linear controllers based on a new non-linear model. Experimental results allow validating the proposed power architecture and its associated control. (author)
New non-linear control strategy for non-isolated DC/DC converter with high voltage ratio
International Nuclear Information System (INIS)
Shahin, A.; Huang, B.; Martin, J.P.; Pierfederici, S.; Davat, B.
2010-01-01
In this paper, a non-isolated DC/DC converter with high voltage ratio is proposed to allow the interface between a low voltage power source like fuel cell and a high voltage DC bus. To take into account the low voltage-high density characteristics of power sources, a cascaded structure composed of two sub-converters has been chosen and allows obtaining a high voltage ratio. The choice of each sub-converter is based on the requirements of the source and its performances. Consequently, we have chosen a three-interleaved boost converter as the 1st sub-converter whereas the 2nd sub-converter is a three-level boost converter. The control of the whole system is realized thanks to energetic trajectories planning based on flatness properties of the system. The control of both the current and the balance of voltage across the output serial capacitors of the three-level boost converter is ensured by non-linear controllers based on a new non-linear model. Experimental results allow validating the proposed power architecture and its associated control.
Frequency Adaptability of Harmonics Controllers for Grid-Interfaced Converters
DEFF Research Database (Denmark)
Yang, Yongheng; Zhou, Keliang; Blaabjerg, Frede
2017-01-01
sensitivity of the most popular harmonic controllers for grid-interfaced converters. The frequency adaptability of these harmonic controllers is evaluated in the presence of a variable grid frequency within a specified reasonable range, e.g., +-1% of the nominal grid frequency (50 Hz). Solutions...
Nonlinear Passive Control of a Wave Energy Converter Subject to Constraints in Irregular Waves
Directory of Open Access Journals (Sweden)
Liguo Wang
2015-06-01
Full Text Available This paper investigates a passive control method of a point absorbing wave energy converter by considering the displacement and velocity constraints under irregular waves in the time domain. A linear generator is used as a power take-off unit, and the equivalent damping force is optimized to improve the power production of the wave energy converter. The results from nonlinear and linear passive control methods are compared, and indicate that the nonlinear passive control method leads to the excitation force in phase with the velocity of the converter that can significantly improve the energy production of the converter.
New control strategy for grid connecting of wind turbine inverter without converter reactor
DEFF Research Database (Denmark)
Rasmussen, Tonny Wederberg; Sørensen, Kasper B.; Bjørneboe, Daniel
2013-01-01
Wind turbines and the belonging converters increase in size and price. A reduction in the number of main components is desirable while it reduces need of space, investments and increases the efficiency. A wind turbine contains both a converter reactor and a step up transformer. The paper presents...... theory and laboratory measurements for a new control strategy which make it possibly to connect a wind turbine converter to the utility grid without using the converter reactor or make measurements at the high voltage side of the transformer. The capability to control the DC voltage and reactive power...
IMPULSE CONTROL HYBRID ELECTRICAL SYSTEM
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A. A. Lobaty
2016-01-01
Full Text Available This paper extends the recently introduced approach for modeling and solving the optimal control problem of fixedswitched mode DC-DC power converter. DCDC converters are a class of electric power circuits that used extensively in regulated DC power supplies, DC motor drives of different types, in Photovoltaic Station energy conversion and other applications due to its advantageous features in terms of size, weight and reliable performance. The main problem in controlling this type converters is in their hybrid nature as the switched circuit topology entails different modes of operation, each of it with its own associated linear continuous-time dynamics.This paper analyses the modeling and controller synthesis of the fixed-frequency buck DC-DC converter, in which the transistor switch is operated by a pulse sequence with constant frequency. In this case the regulation of the DC component of the output voltage is via the duty cycle. The optimization of the control system is based on the formation of the control signal at the output.It is proposed to solve the problem of optimal control of a hybrid system based on the formation of the control signal at the output of the controller, which minimizes a given functional integral quality, which is regarded as a linear quadratic Letov-Kalman functional. Search method of optimal control depends on the type of mathematical model of control object. In this case, we consider a linear deterministic model of the control system, which is common for the majority of hybrid electrical systems. For this formulation of the optimal control problem of search is a problem of analytical design of optimal controller, which has the analytical solution.As an example of the hybrid system is considered a step-down switching DC-DC converter, which is widely used in various electrical systems: as an uninterruptible power supply, battery charger for electric vehicles, the inverter in solar photovoltaic power plants.. A
Directory of Open Access Journals (Sweden)
Chandra Babu Paduchuri
2014-01-01
Full Text Available A design of multiconverter unified power quality conditioner to improve the power quality issues is presents in this paper. Modified SRF theory and fuzzy logic controller technique are incorporated in this modelling. This newly designed controller is connected to a source in order to compensate voltage and current in the two feeders. The expanded concept of UPQC is multi converter-UPQC; this system has two series voltage source converter (VSC and one shunt VSC connected back to back. In the proposed system, the power can be conveyed from one feeder to another in order to mitigate the voltage sag, swell, interruption and transient response of the system. The control strategies of multi converter-UPQC are designed based on the modified synchronous reference frame theory with fuzzy logic controller. The transient response of the fuzzy logic controller in dc-link voltage controller will be very fast. The relevant simulation and compensation performance analysis of multi converter-UPQC with fuzzy logic controller is performed using MATLAB/Simulink software.
DISEÑO E IMPLEMENTACIÓN DE UN CONTROL DUAL POR MODOS DESLIZANTES PARA UN CONVERTIDOR BUCK CD-CA
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Jaime Ayala Taco
2015-01-01
Full Text Available El presente trabajo muestra un análisis orientado a la propuesta de diseño e implementaciónde un doble controlador en modo deslizante para un convertidor Buck CD-CA. Se planteanlas superficies de deslizamiento candidatas de acuerdo con las exigencias de la aplicación y,mediante una lógica de activación de las llaves semiconductoras (MOSFET, se obtiene un controlindependiente en la amplitud de la tensión para el semiciclo positivo y negativo de la onda desalida en CA, con el objetivo de lograr a voluntad un nivel de CD introducido en la señal de alterna.Se ingresan perturbaciones de tensión en la entrada del convertidor y se producen variacionesen la carga con el objetivo de probar la robustez del sistema de control propuesto. El controlse implementa en un microcontrolador AVR Atmega164PA y se prueba de manera práctica.Finalmente, se expone una comparación de los resultados obtenidos de manera experimentalcon las simulaciones realizadas en SCILAB5.
Interlink Converter with Linear Quadratic Regulator Based Current Control for Hybrid AC/DC Microgrid
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Dwi Riana Aryani
2017-11-01
Full Text Available A hybrid alternate current/direct current (AC/DC microgrid consists of an AC subgrid and a DC subgrid, and the subgrids are connected through the interlink bidirectional AC/DC converter. In the stand-alone operation mode, it is desirable that the interlink bidirectional AC/DC converter manages proportional power sharing between the subgrids by transferring power from the under-loaded subgrid to the over-loaded one. In terms of system security, the interlink bidirectional AC/DC converter takes an important role, so proper control strategies need to be established. In addition, it is assumed that a battery energy storage system is installed in one subgrid, and the coordinated control of interlink bidirectional AC/DC converter and battery energy storage system converter is required so that the power sharing scheme between subgrids becomes more efficient. For the purpose of designing a tracking controller for the power sharing by interlink bidirectional AC/DC converter in a hybrid AC/DC microgrid, a droop control method generates a power reference for interlink bidirectional AC/DC converter based on the deviation of the system frequency and voltages first and then interlink bidirectional AC/DC converter needs to transfer the power reference to the over-loaded subgrid. For efficiency of this power transferring, a linear quadratic regulator with exponential weighting for the current regulation of interlink bidirectional AC/DC converter is designed in such a way that the resulting microgrid can operate robustly against various uncertainties and the power sharing is carried out quickly. Simulation results show that the proposed interlink bidirectional AC/DC converter control strategy provides robust and efficient power sharing scheme between the subgrids without deteriorating the secure system operation.
Novel operation and control modes for series-resonant converters
Haan, de S.W.H.; Huisman, H.
1985-01-01
A series-resonant converter (SRC) able to generate an output voltage either lower or higher than the source voltage is described. Moreover, a novel control scheme is presented which renders two degrees of freedom for control and which guarantees symmetrical steady-state waveforms in all operation
National Research Council Canada - National Science Library
Floodeen, David
1998-01-01
The objective of this thesis is two-fold. The first goal is to expand the operational capabilities of the Ship's Service Converter Module control algorithm for a DC-to-DC converter using the Universal Controller...
A frequency controlled LCL - T resonant converter for H- ion source
International Nuclear Information System (INIS)
Gauttam, V.K.; Kasliwal, A.; Banwari, R.; Pandit, T.G.; Thakurta, A.C.
2013-01-01
An H - ion source is being developed at Raja Ramanna Centre for Advanced Technology, Indore. An LCL-T resonant power converter with variable frequency control is proposed which is utilized to develop a -20 kV/100 mA high voltage (HV) power supply for extraction of H - ions. The LCL-T resonant topology offers many advantages like gainful utilization of the transformer parasitics as a part of resonant network and low circulating current. The power converter is operated with variable frequency control and above resonance to get well known zero-voltage switching (ZVS) advantages for full bridge semiconductor switches in full load range. The converter energizes the symmetrical Cockcroft-Walton (CW) based HV generator to achieve required high voltage. The CW circuit is an attractive solution for HV generation since it has features like low stored energy and low output ripple. The HV power supply is operated in constant current (CC) mode with closed loop control and soft start of the power supply is achieved by sweeping the switching frequency from 40 kHz to defined operating point. Design parameters, simulation results and experimental results of the power converter are presented in this paper. (author)
Modeling and Analysis of Power Processing Systems (MAPPS). Volume 2: Appendices
Lee, F. C.; Radman, S.; Carter, R. A.; Wu, C. H.; Yu, Y.; Chang, R.
1980-01-01
The computer programs and derivations generated in support of the modeling and design optimization program are presented. Programs for the buck regulator, boost regulator, and buck-boost regulator are described. The computer program for the design optimization calculations is presented. Constraints for the boost and buck-boost converter were derived. Derivations of state-space equations and transfer functions are presented. Computer lists for the converters are presented, and the input parameters justified.
Control of a Stand-Alone Variable Speed Wind Energy Supply System †
Directory of Open Access Journals (Sweden)
Mohamed M. Hamada
2013-04-01
Full Text Available This paper presents a simple control strategy for the operation of a variable speed stand-alone wind turbine with a permanent magnet synchronous generator (PMSG. The PMSG is connected to a three phase resistive load through a switch mode rectifier and a voltage source inverter. Control of the generator side converter is used to achieve maximum power extraction from the available wind power. Control of the DC-DC bidirectional buck-boost converter, which is connected between batteries bank and DC-link voltage, is used to maintain the DC-link voltage at a constant value. It is also used to make the batteries bank stores the surplus of wind energy and supplies this energy to the load during a wind power shortage. The load side voltage source inverter uses a relatively complex vector control scheme to control the output load voltage in terms of amplitude and frequency. The control strategy works under wind speed variation as well as with variable load. Extensive simulation results have been performed using MATLAB/SIMULINK.
A Zero Input Current Ripple ZVS/ZCS Boost Converter with Boundary-Mode Control
Directory of Open Access Journals (Sweden)
Ching-Ming Lai
2014-10-01
Full Text Available In this paper, in order to achieve zero ripple conditions, the use of a ripple mirror (RM circuit for the boost converter is proposed. The operation modes are studied and steady-state analyses performed to show the merits of the proposed converter. It is found that the proposed RM circuit technique can provide much better flexibility than the two-phase interleaved boost converter for locating the zero ripple operating point in the design stage. In addition, the choice of using a boundary-mode control is mainly based on the consideration of achieving both ZVS (zero voltage switching/ZCS (zero current switching soft-switching and constant on-time control for the converter. To verify the performance of the proposed converter, a 48 V input and 200 W/200 V output prototype is constructed. Experimental results verify the effectiveness of the proposed converter.
Tuning of Passivity-Preserving Controllers for Switched-Mode Power Converters
Jeltsema, Dimitri; Scherpen, Jacquelien M.A.
2004-01-01
Nonlinear passivity-based control (PBC) algorithms for power converters have proved to be an interesting alternative to other, mostly linear, control techniques. The control objective is usually achieved through an energy reshaping process and by injecting damping to modify the dissipation structure
Modular Multilevel Converters: Control and Applications
Directory of Open Access Journals (Sweden)
Fernando Martinez-Rodrigo
2017-10-01
Full Text Available This review article is mainly oriented to the control and applications of modular multilevel converters (MMC. The main topologies of the switching modules are presented, for normal operation and for the elimination of DC faults. Methods to keep the capacitor voltage balanced are included. The voltage and current modulators, that are the most internal loops of control, are detailed. Voltage control and current control schemes are included which regulate DC link voltage and reactive power. The cases of unbalanced and distorted networks are analyzed, and schemes are proposed so that MMC contribute to improve the quality of the grid in these situations. The main applications in high voltage direct current (HVDC transmission along with other medium voltage (MV and low voltage (LV applications are included. Finally, the application to offshore wind farms is specifically analyzed.
Control of Modular Multilevel Converter with reduced internal data exchange
DEFF Research Database (Denmark)
Máthé, Lászlo; Burlacu, Paul Dan; Teodorescu, Remus
2017-01-01
for such an application, several key parameters have to be considered such as high speed data transfer with low propagation delay, data integrity, and ability for accurate synchronization. In order to minimize the data flow in the MMC a hierarchical control is proposed where a CCU calculates an identical reference......Modular Multilevel Converters (MMC) are penetrating due to their superior performances. Due to the modular structure of the converter, communication platform has to be established between the Sub-Modules (SM) and a Central Controller Unit (CCU). When the communication platform is designed...... for all the SMs while the modulation and capacitor voltage balancing is performed in the controller from the SM. Thus, at each sampling instance only four bytes references are sent by the central controller to the controllers from the SM, while one or two bytes are received from SMs. Further, the control...
Directory of Open Access Journals (Sweden)
H. Gado
2015-06-01
Full Text Available A total of 144 adult Hy-Plus rabbit bucks were randomly assigned into four treatments of 36 replicates each, in a completely randomized design. Animals were fed ad libitum on basal diet supplemented with an enzyme complex (EZ at 0 (EZ0, 1 (EZ1, 3 (EZ3 and 5 (EZ5 kg/ton of feed. Total sperm count was higher (P<0.05 in EZ5 than in EZ0. Sperm motility increased with increasing levels of the EZ additive being lowest for EZ0 and highest for EZ5 rabbits (P<0.05. Percentage of dead sperm was higher (P<0.05 in EZ0 than in EZ5 rabbits. Rabbit bucks received the highest levele of EZ in their diet, had the shorter reaction time (22.31±3.17 sec; P<0.05,whereas EZ5 bucks took 43.56±5.89 sec to mount does for the first time after exposure. Blood testosterone, 17α-estradiol and progesterone levels were highest in EZ5 rabbits and lowest in EZ0 rabbits. Enzyme addition increased (P<0.05 sperm transit in estrus doe cervical mucus. Data suggested that the EZ additive in diets of adult Hy-Plus rabbit bucks was effective to improve both semen characteristics and sexual drive.
Control of the DC-DC Converter used into Energy Generation System
International Nuclear Information System (INIS)
Bizon, Nicu; Oproescu, Mihai
2006-01-01
This paper presents an investigation of the DC-DC Converter controller used into Energy Generation System. The full bridge is used into an Energy Generation System (EGS) as second power interface between the energy source and the high DC bus. The simulation results show that the DC-DC Converter behavior can be improved using a well designed PI control surface. The used Simulink models for the EGS blocks and some design considerations are presented, too. (authors)
Double Up Food Bucks program effects on SNAP recipients' fruit and vegetable purchases.
Steele-Adjognon, Marie; Weatherspoon, Dave
2017-12-12
To encourage the consumption of more fresh fruits and vegetables, the 2014 United Sates Farm Bill allocated funds to the Double Up Food Bucks Program. This program provided Supplemental Nutrition Assistance Program beneficiaries who spent $10 on fresh fruits and vegetables, in one transaction, with a $10 gift card exclusively for Michigan grown fresh fruits and vegetables. This study analyzes how fruit and vegetable expenditures, expenditure shares, variety and purchase decisions were affected by the initiation and conclusion, as well as any persistent effects of the program. Changes in fruit and vegetable purchase behaviors due to Double Up Food Bucks in a supermarket serving a low-income, predominantly Hispanic community in Detroit, Michigan were evaluated using a difference in difference fixed effects estimation strategy. We find that the Double Up Food Bucks program increased vegetable expenditures, fruit and vegetable expenditure shares, and variety of fruits and vegetables purchased but the effects were modest and not sustainable without the financial incentive. Fruit expenditures and the fruit and vegetable purchase decision were unaffected by the program. This study provides valuable insight on how a nutrition program influences a low-income, urban, Hispanic community's fruit and vegetable purchase behavior. Policy recommendations include either removing or lowering the purchase hurdle for incentive eligibility and dropping the Michigan grown requirement to better align with the customers' preferences for fresh fruits and vegetables.
Simple Digital Control of a Two-Stage PFC Converter Using DSPIC30F Microprocessor
DEFF Research Database (Denmark)
Török, Lajos; Munk-Nielsen, Stig
2010-01-01
The use of dsPIC digital signal controllers (DSC) in Switch Mode Power Supply (SMPS) applications opens new perspectives for cheap and flexible digital control solutions. This paper presents the digital control of a two stage power factor corrector (PFC) converter. The PFC circuit is designed...... and built for 70W rated output power. Average current mode control for boost converter and current programmed control for forward converter are implemented on a dsPIC30F1010. Pulse Width Modulation (PWM) technique is used to drive the switching MOSFETs. Results show that digital solutions with ds...
Young, Candace R; Aquilante, Jennifer L; Solomon, Sara; Colby, Lisa; Kawinzi, Mukethe A; Uy, Nicky; Mallya, Giridhar
2013-10-03
We evaluated whether Philly Food Bucks, a bonus incentive program at farmers markets, is associated with increased fruit and vegetable consumption and Supplemental Nutrition Assistance Program (SNAP) sales at farmers markets in low-income areas. A convenience sample of 662 customers at 22 farmers markets in low-income neighborhoods in Philadelphia, Pennsylvania, was surveyed via face-to-face interviews. Questions addressed shopping characteristics, self-reported change in fruit and vegetable consumption, whether customers tried new fruits or vegetables, use of Philly Food Bucks, and demographic information. Market-level SNAP sales and Philly Food Bucks redemption data were also collected to monitor sales patterns. Philly Food Bucks users were significantly more likely than nonusers to report increasing fruit and vegetable consumption (OR, 2.4; 95% CI, 1.6-3.7; P < .001) and to report trying new fruits or vegetables (OR 1.8; 95% CI, 1.2-2.7; P = .006). At the market level, average SNAP sales more than doubled at farmers markets in low-income areas in the first 2 years of the Philly Food Bucks program. At the city's largest farmers market in a low-income area, the program was associated with an almost 5-fold higher increase in annual SNAP sales compared with baseline. Results from this study demonstrate that a bonus incentive program tied to SNAP was associated with self-reported increases in fruit and vegetable consumption and increased SNAP sales at participating farmers markets in low-income communities. More research is warranted to evaluate the long-term impact of bonus incentives on farmers market use, dietary behaviors, and health outcomes.
Feasibility analysis of fuzzy logic control for ITER Poloidal field (PF) AC/DC converter system
Energy Technology Data Exchange (ETDEWEB)
Hassan, Mahmood Ul; Fu, Peng [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); University of Science and Technology of China (China); Song, Zhiquan, E-mail: zhquansong@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Chen, Xiaojiao [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); University of Science and Technology of China (China); Zhang, Xiuqing [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Humayun, Muhammad [Shanghai Jiaotong University (China)
2017-05-15
Highlights: • The implementation of the Fuzzy controller for the ITER PF converter system is presented. • The comparison of the FLC and PI simulation are investigated. • The FLC single and parallel bridge operation are presented. • Fuzzification and Defuzzification algorithms are presented using FLC controller. - Abstract: This paper describes the feasibility analysis of the fuzzy logic control to increase the performance of the ITER poloidal field (PF) converter systems. A fuzzy-logic-based controller is designed for ITER PF converter system, using the traditional PI controller and Fuzzy controller (FC), the dynamic behavior and transient response of the PF converter system are compared under normal operation by analysis and simulation. The analysis results show that the fuzzy logic control can achieve better operation performance than PI control.
Elimination of output voltage oscillations in DC-DC converter using PWM with PI controller
Directory of Open Access Journals (Sweden)
Sreenivasappa Veeranna Bhupasandra
2010-01-01
Full Text Available In this paper the SIMULINK model of a PWM controlled DC-DC converter is modeled using switching function concept to control the speed of the DC motor. The presence of the voltage oscillation cycles due to higher switching frequency in the DC-DC converter is identified. The effect of these oscillations on the output voltage of the converter, Armature current, Developed torque and Speed of the DC motor is analyzed. In order to minimize the oscillation cycles the PI controller is proposed in the PWM controller.
A VHF Interleaved Self-Oscillating Resonant SEPIC Converter with Phase-Shift Burst-Mode Control
DEFF Research Database (Denmark)
Kovacevic, Milovan; Knott, Arnold; Andersen, Michael A. E.
2014-01-01
This paper presents design and implementation of the phase-shift burst-mode control method for interleaved selfoscillating resonant SEPIC converters for LED lighting applications. The proposed control method utilizes delays in the turn-on and turn-off of the power stage and control circuitry...... in order to reduce requirements for the comparator in the regulation circuit. The control method is experimentally evaluated on a 49 MHz dc-dc converter prototype, and the results are presented. The designed converter demonstrates peak efficiency of 81%, maintains efficiency above 75% from 20% load to full...
Auxiliary controller for time-to-digital converter module readout
International Nuclear Information System (INIS)
Ermolin, Yu.V.
1992-01-01
The KD-225 auxiliary controller for time-to-digital converter module readout in the SUMMA crate is described. After readout and preliminary processing the data are written in the P-140 buffer memory module. The controller is used in the FODS-2 experimental setup data acquisition system. 12 refs.; 1 fig
A Unified Voltage Harmonic Control Strategy for Coordinated Compensation with VCM and CCM Converters
DEFF Research Database (Denmark)
Zhao, Xin; Meng, Lexuan; Xie, Chuan
2018-01-01
-controlled mode (VCM) and current-controlled mode (CCM), need to cooperatively provide the compensation function. Aiming at this objective, this paper proposes a unified voltage harmonic mitigation strategy for VCM and CCM converters with high harmonic current sharing accuracy. Another advantage of the proposal......Harmonics have been considered as one of the major issues in modern power grids. Considering the high penetration level of power electronic converter interfaced distributed generators (DGs), it is of interest to provide ancillary services through DG interfacing converters, such as harmonic...... compensation. In case of that, multiple DG interfacing converters are utilized to compensate harmonics, and the compensation effort should be properly shared among these converters. However, it is rarely considered in existing literatures that converters operating in different modes, such as voltage...
On theory and simulation of heaving-buoy wave-energy converters with control
Energy Technology Data Exchange (ETDEWEB)
Eidsmoen, H.
1995-12-01
Heaving-buoy wave-energy converters with control were studied. The buoy is small compared to the wavelength. The resonance bandwidth is then narrow and the energy conversion in irregular waves can be significantly increased if the oscillatory motion of the device can be actively controlled, and the power output from the converter will vary less with time than the wave power transport. A system of two concentric cylinders of the same radius, oscillating in heave only, is analysed in the frequency-domain. The mathematical model can be used to study a tight-moored buoy, as well as a buoy reacting against a submerged body. The knowledge of the frequency-domain hydrodynamic parameters is used to develop frequency-domain and time-domain mathematical models of heaving-buoy wave energy converters. The main emphasis is on using control to maximize the energy production and to protect the machinery of the wave-energy converter in very large waves. Three different methods are used to study control. (1) In the frequency-domain explicit analytical expressions for the optimum oscillation are found, assuming a continuous sinusoidal control force, and from these expressions the optimum time-domain oscillation can be determined. (2) The second method uses optimal control theory, using a control variable as the instrument for the optimisation. Unlike the first method, this method can include non-linearities. But this method gives numerical time series for the state variables and the control variable rather than analytical expressions for the optimum oscillation. (3) The third method is time-domain simulation. Non-linear forces are included, but the method only gives the response of the system to a given incident wave. How the different methods can be used to develop real-time control is discussed. Simulations are performed for a tight-moored heaving-buoy converter with a high-pressure hydraulic system for energy production and motion control. 147 refs., 38 figs., 22 tabs.
Design, Control and Application of Modular Multilevel Converters for HVDC Transmission Systems
DEFF Research Database (Denmark)
Sharifabadi, Kamran; Harnefors, Lennart; Nee, Hans-Peter
distinct parts, the first offers an overview of MMC technology, including information on converter component sizing, Control and Communication, Protection and Fault Management, and Generic Modelling and Simulation. The second covers the applications of MMC in offshore WPP, including planning, technical......Design, Control and Application of Modular Multilevel Converters for HVDC Transmission Systems is a comprehensive guide to semiconductor technologies applicable for MMC design, component sizing control, modulation, and application of the MMC technology for HVDC transmission. Separated into three...
Grid-connected Photovoltaic Micro-inverter with New Hybrid Control LLC Resonant Converter
DEFF Research Database (Denmark)
Xingkui, Mao; Qisheng, Huang; Qingbo, Ke
2016-01-01
A high-efficiency photovoltaic (PV) micro-inverter consisting of two power stages i.e. a LLC resonant converter with a new hybrid control scheme and a dc-ac inverter is proposed, studied and designed in this paper. In the first power stage, the new hybrid control combining pulse-frequency modulat......A high-efficiency photovoltaic (PV) micro-inverter consisting of two power stages i.e. a LLC resonant converter with a new hybrid control scheme and a dc-ac inverter is proposed, studied and designed in this paper. In the first power stage, the new hybrid control combining pulse......-frequency modulation (PFM) and phase-shift pulse-width modulation (PS-PWM) is employed on a full-bridge LLC dc-dc converter, in order to achieve high efficiency when PV output voltage varies in a wide range. Moreover, a maximum power point tracking (MPPT) method based on power perturbation is implemented in the dc...
Introducing state-trajectory control for the synchronous interleaved boost converter
DEFF Research Database (Denmark)
Peña-Alzola, Rafael; Ksiazek, Peter; Ordonez, Martin
2015-01-01
Synchronous interleaved boost converters (SIBCs) result in lower ripple currents and bidirectional power flow. The boost topology has a non-minimum phase characteristic, producing instability problems when a large bandwidth is required. Linear controllers inherently limit the boost controller...
Design, operation and control of series-connected power converters for offshore wind parks
Energy Technology Data Exchange (ETDEWEB)
Ruiz, Alejandro Garces
2012-07-01
Offshore wind farms need to develop technologies that fulfill three main objectives:Efficiency, power density and reliability. The purpose of this thesis is to study an HVDC transmission system based on series connection of the turbines which theoretically meet these three objectives. A new topology of matrix converter operated at high frequency is proposed. This converter is studied using different modulation algorithms. Simulation and experimental results demonstrated that the converter can be operated as a current source converter with high efficiency. An optimal control based on a linear quadratic regulator is propose dto control the matrix converter as well as the converter placed on shore. Results demonstrated the high performance of this type of control and its simplicity for implementation. An stationary state study based on non-linear programming and Montecarlo simulation was carried out to determine the performance of the concept for long-term operation. Series connection is an efficient technology if and only if the differences in the effective wind velocity are small. This aspect limits the number of wind turbines that can be connected in series, since a numerous number of turbines will lead to high covariances in the distribution of the wind. A complementary study about active filter and reactive power compensation was carried out using an optimization-based algorithm. (Author)
Advanced Control Strategy of Back-to-Back PWM Converters in PMSG Wind Power System
Directory of Open Access Journals (Sweden)
Tan Luong Van
2015-01-01
Full Text Available This paper proposes a control scheme of back-to-back PWM converters for the permanent magnet synchronous generator (PMSG wind turbine system. The DC-link voltage can be controlled at the machine-side converter (MSC, while the grid-side converter (GSC controls the grid active power for a maximum power point tracking (MPPT. At the grid fault condition, the DC-link voltage controller is designed using a feedback linearization (FL theory. For the MPPT, a proportional control loop is added to the torque control to reduce the influence of the inertia moment in the wind turbines, which can improve its dynamic performance. The validity of this control algorithm has been verified by the simulation of the 2-MW PMSG wind turbine system.
DEFF Research Database (Denmark)
Gong, Zheng; Dai, Peng; Wu, Xiaojie
2017-01-01
In recent years, voltage source multilevel converters are very popular in medium/high-voltage industrial applications, among which the NPC/H-Bridge converter is a popular solution to the medium/high-voltage drive systems. The conventional finite control set model predictive control (FCS-MPC) stra......In recent years, voltage source multilevel converters are very popular in medium/high-voltage industrial applications, among which the NPC/H-Bridge converter is a popular solution to the medium/high-voltage drive systems. The conventional finite control set model predictive control (FCS......-MPC) strategy is not practical for multilevel converters due to their substantial calculation requirements, especially under high number of voltage levels. To solve this problem, a hierarchical model predictive voltage control (HMPVC) strategy with referring to the implementation of g-h coordinate space vector...... and experiments with a down-scaled NPC/H-Bridge converter prototype under various conditions, which validate the proposed HMPVC strategy....
Space vector-based modeling and control of a modular multilevel converter in HVDC applications
DEFF Research Database (Denmark)
Bonavoglia, M.; Casadei, G.; Zarri, L.
2013-01-01
Modular multilevel converter (MMC) is an emerging multilevel topology for high-voltage applications that has been developed in recent years. In this paper, the modeling and the control of MMCs are restated in terms of space vectors, which may allow a deeper understanding of the converter behavior....... As a result, a control scheme for three-phase MMCs based on the previous theoretical analysis is presented. Numerical simulations are used to test its feasibility.......Modular multilevel converter (MMC) is an emerging multilevel topology for high-voltage applications that has been developed in recent years. In this paper, the modeling and the control of MMCs are restated in terms of space vectors, which may allow a deeper understanding of the converter behavior...
Directory of Open Access Journals (Sweden)
Muhammad Rizal
2008-03-01
Full Text Available In processing of buck semen, seminal plasma is a problem because it contains a phospholipase A enzime produced by the Cowper gland. If this enzime interacts with egg yolk, it causes semen coagulation, and consequently death of spermatozoa. The purpose of this research was to examine the effect of Priangan ram seminal plasma on viability of Peranakan Etawah (PE buck spermatozoa preserved at 3–5oC. Semen was collected using artificial vagina once a week. Fresh semen was divided into three tubes then centrifuged at 3,000 RPM for 30 min. Supernatant of the first tube was mixed again with Pasteur pipette (treatment A or control. Supernatant of the second tube was removed (treatment B or without seminal plasma. Supernatant of the third tube was removed and changed with Priangan ram seminal plasma in the same volume (treatment C. Semen was diluted with Tris extender containing 20% egg yolk and stored in refrigerator at 3–5oC. Quality of diluted-semen including percentages of motile spermatozoa (MS, live spermatozoa (LS, and intact plasma membrane (IPM was evaluated every day during storage at 3–5oC for three days. Results of this study showed that mean volume, colour, consistency, pH, mass activity, spermatozoa concentration, MS, LS, spermatozoa abnormal, and IPM of PE buck fresh semen, respectively was 0.68 ml, cream, thick, 7, ++/+++, 4,148.57 million cell/ml, 70%, 83.89%, 7.12% and 84%. At day-4 of storage, percentages of MS, LS, and IPM for treatment C (40, 52.2 and 51.6% was significantly (P<0.05 higher than that of: treatment B (31, 44.8 and 45.2% and treatment A (11, 15.6 and 14.8%. In conclusion, seminal plasma of Priangan ram could maintain the quality of PE buck semen preserved at 3–5oC for three days, and it prevent semen from coagulation.
A high-efficiency, low-noise power solution for a dual-channel GNSS RF receiver
International Nuclear Information System (INIS)
Shi Jian; Mo Taishan; Gan Yebing; Ma Chengyan; Ye Tianchun; Le Jianlian
2012-01-01
A high-efficiency low-noise power solution for a dual-channel GNSS RF receiver is presented. The power solution involves a DC—DC buck converter and a followed low-dropout regulator (LDO). The pulse-width-modulation (PWM) control method is adopted for better noise performance. An improved low-power high-frequency PWM control circuit is proposed, which halves the average quiescent current of the buck converter to 80 μA by periodically shutting down the OTA. The size of the output stage has also been optimized to achieve high efficiency under a light load condition. In addition, a novel soft-start circuit based on a current limiter has been implemented to avoid inrush current. Fabricated with commercial 180-nm CMOS technology, the DC—DC converter achieves a peak efficiency of 93.1% under a 2 MHz working frequency. The whole receiver consumes only 20.2 mA from a 3.3 V power supply and has a noise figure of 2.5 dB. (semiconductor integrated circuits)
Designing of new structure PID controller of boost converter for solar photovoltaic stability
Shabrina, Hanifati Nur; Setiawan, Eko Adhi; Sabirin, Chip Rinaldi
2017-03-01
Nowadays, the utilization of renewable energy as the source on distributed generation system is increasing. It aims to reduce reliance and power losses from utility grid and improve power stability in near loads. One example of renewable energy technology that have been highly proven on the market is solar photovoltaic (PV). This technology converts photon from sunlight into electricity. However, the fluctuation of solar radiation that often occurs become the main problem for this system. Due to this condition, the power conversion is needed to convert the change frequently in photovoltaic panel into a stable voltage to the system. Developing control of boost converter has important role to keep ability of system stabilization. A conventional PID (Proportional, Integral, Derivative) control is mostly used to achieve this goal. In this research, a design of new structure PID controller of boost converter is offered to better optimize system stability comparing to the conventional PID. Parameters obtained from this PID structure have been successfully yield a stable boost converter output at 200 V with 10% overshoot, 1.5 seconds of settling time, and 1.5% of steady-state error.
Design of practical sliding-mode controllers with constant switching frequency for power converters
Energy Technology Data Exchange (ETDEWEB)
Navarro-Lopez, Eva M. [School of Computer Science, Centre for Interdisciplinary Computational and Dynamical Analysis, The University of Manchester, Oxford Road, Kilburn Building, Manchester M13 9PL (United Kingdom); Cortes, Domingo [Seccion de Mecatronica, Departamento de Ingenieria Electrica, CINVESTAV-IPN, Av. IPN 2508, Col. San Pedro Zacatenco, 07360 Mexico City (Mexico); Castro, Christian [Centro de Investigacion en Computacion del IPN, Av. Jose Othon de Mendizabal s/n, Col. Nueva Industrial Vallejo, 07738 Mexico City (Mexico)
2009-05-15
A novel experimentally motivated method in order to design a family of easy-to-implement sliding-mode controllers for power converters is proposed. Two main results are presented. First, the relation between sliding-mode control and average control is reinterpreted so that the limitation of the switching frequency for the closed-loop system is achieved in a more direct way than other methods so far reported in the literature. For this purpose, a class of sliding surfaces which makes the associated equivalent control be the system average control is proposed. Second, the achievement of a constant switching frequency in the controlled system is assured without requiring the sliding-mode-based controller to be modified, unlike most previous works. As a result, the proposed sliding surfaces-type can be directly implemented via a pulse-width modulator. The control methodology is implemented for the voltage control in a boost converter prototype in which the load is considered unknown. Experimental results confirm high performance and robustness under parameters variation. Furthermore, the solution proposed is easy to implement and well-suited for other power converters. (author)
DEFF Research Database (Denmark)
Su, Chi; Liu, Zhou; Chen, Zhe
2014-01-01
of network protection devices. As a protection measure commonly used in distribution network, recloser-fuse coordination could suffer from this impact. Research work has been conducted to deal with this problem by modifying the control strategy of the DG converters during faults. These solutions generally...... reduce the current output from the converters during faults so as to mitigate the influence on protection coordination. However, converter current reduction may not be necessary for all types of faults. This paper proposes a converter control strategy with adaptivity to different fault types and also non......-fault voltage drop events. This control strategy is validated by simulations in DIgSILENT PowerFactory....
DEFF Research Database (Denmark)
Török, Lajos; Munk-Nielsen, Stig
2011-01-01
A comparison of an analog and a digital controller driven 70 W two-stage power factor corrector converter is presented. Both controllers are operated in average current-mode-control for the PFC and peak current control for the DC-DC converter. Digital controller design and converter modeling...... is described. Results show that digital control can compete with the analog one in efficiency, PFC and THD....
Model Predictive Control of Buoy Type Wave Energy Converter
DEFF Research Database (Denmark)
Soltani, Mohsen N.; Sichani, Mahdi T.; Mirzaei, Mahmood
2014-01-01
by forcing this condition. In the paper the theoretical framework for this principal is shown. The optimal controller requires information of the sea state for infinite horizon which is not applicable. Model Predictive Controllers (MPC) can have finite horizon which crosses out this requirement....... This approach is then taken into account and an MPC controller is designed for a model wave energy converter and implemented on a numerical example. Further, the power outtake of this controller is compared to the optimal controller as an indicator of the performance of the designed controller....
Digital peak current mode control with adaptive slope compensation for DC-DC converters
DEFF Research Database (Denmark)
Andersen, Karsten Holm; Nymand, Morten
2017-01-01
performance and stability of current mode control. The presented method adapt to DC-DC converter operating conditions by estimating the rising and falling inductor current slopes, to apply a current slope compensation value to obtain a constant quality factor. The experimental results verifies the theoretical......This paper presents an adaptive slope compensation method for peak current mode control of digital controlled DC-DC converters, which controls the quality factor of the complex conjugated poles at half the switching frequency. Using quality factor control enables optimization of the dynamic...
Development, analysis, and control of the inductor-converter bridge
International Nuclear Information System (INIS)
Ehsani, M.; Kustom, R.L.
1981-08-01
The inductor-converter bridge (ICB) is a solid state dc-ac-dc power converter system for bidirectional, controllable, energy transfer between two high Q magnet coils. The ICB is suitable for supplying large pulsed power to such magnets as the superconducting equilibrium field (EF) coil of the proposed tokamak power reactors, from another superconducting energy storage coil. This report presents work on the analysis and control of the ICB system. The process of energy transfer between the coils is explained on the basis of a simple one line equivalent circuit. This circuit is the topological dual of the one line diagram of the nonsalient pole synchoronous generator, connected to the infinite bus through its synchronous reactance. The changes in the average power, average coil currents, and voltages, as functions of time, are calculated by the conventional Fourier method of analysis
Development, analysis, and control of the inductor-converter bridge
Energy Technology Data Exchange (ETDEWEB)
Ehsani, Mehrdad; Kustom, Robert L.
1981-08-01
The inductor-converter bridge (ICB) is a solid state dc-ac-dc power converter system for bidirectional, controllable, energy transfer between two high Q magnet coils. The ICB is suitable for supplying large pulsed power to such magnets as the superconducting equilibrium field (EF) coil of the proposed tokamak power reactors, from another superconducting energy storage coil. This report presents work on the analysis and control of the ICB system. The process of energy transfer between the coils is explained on the basis of a simple one line equivalent circuit. This circuit is the topological dual of the one line diagram of the nonsalient pole synchoronous generator, connected to the infinite bus through its synchronous reactance. The changes in the average power, average coil currents, and voltages, as functions of time, are calculated by the conventional Fourier method of analysis.
A Robust Suboptimal Current Control of an Interlink Converter for a Hybrid AC/DC Microgrid
Directory of Open Access Journals (Sweden)
Ismi Rosyiana Fitri
2018-05-01
Full Text Available A hybrid AC/DC microgrid is established with the aim of exploiting numerous types of renewable energy to meet the needs of different loads. The microgrid is decomposed by AC DC sub-grids which are connected by an interlink converter (IC. To maintain the security and reliability of the microgrid, an automatic controller for the interlink converter is needed. In this paper, we propose a Linear Matrix Inequalities (LMI-based current control method for the interlink converter. As the main features here, the interlink converter permits bidirectional power exchange between both sub-grids when a power–demand imbalance occurs in one sub-grid regardless of the converter system parameters. Simulations with various filter parameters are performed using the Matlab/Simulink software to validate the effectiveness of the proposed controller. In comparison with the existing Linear Quadratic Regulator (LQR-based current control, the proposed method is more robust against unknown system parameters and high load perturbation.
Iaverage current mode (ACM) control for switching power converters
2014-01-01
Providing a fast current sensor direct feedback path to a modulator for controlling switching of a switched power converter in addition to an integrating feedback path which monitors average current for control of a modulator provides fast dynamic response consistent with system stability and average current mode control. Feedback of output voltage for voltage regulation can be combined with current information in the integrating feedback path to limit bandwidth of the voltage feedback signal.
Chaotic Behavior in a Switched Dynamical System
Directory of Open Access Journals (Sweden)
Fatima El Guezar
2008-01-01
Full Text Available We present a numerical study of an example of piecewise linear systems that constitute a class of hybrid systems. Precisely, we study the chaotic dynamics of the voltage-mode controlled buck converter circuit in an open loop. By considering the voltage input as a bifurcation parameter, we observe that the obtained simulations show that the buck converter is prone to have subharmonic behavior and chaos. We also present the corresponding bifurcation diagram. Our modeling techniques are based on the new French native modeler and simulator for hybrid systems called Scicos (Scilab connected object simulator which is a Scilab (scientific laboratory package. The followed approach takes into account the hybrid nature of the circuit.
Autonomous Control of Interlinking Converter With Energy Storage in Hybrid AC–DC Microgrid
DEFF Research Database (Denmark)
Loh, Poh Chiang; Li, Ding; Chai, Yi Kang
2013-01-01
, simplicity, and industry relevance of the converter. The desired operating features of the hybrid microgrid can then be added through this interlinking converter. To demonstrate, an appropriate control scheme is now developed for controlling the interlinking converter. The objective is to keep the hybrid......The coexistence of ac and dc subgrids in a hybrid microgrid is likely given that modern distributed sources can either be ac or dc. Linking these subgrids is a power converter, whose topology should preferably be not too unconventional. This is to avoid unnecessary compromises to reliability...... microgrid in autonomous operation with active power proportionally shared among its distributed sources. Power sharing here should depend only on the source ratings and not their placements within the hybrid microgrid. The proposed scheme can also be extended to include energy storage within...
Control of a Modular Multilevel Converter STATCOM under internal and external unbalances
DEFF Research Database (Denmark)
Tsolaridis, Georgios; Kontos, E.; Parikh, Harsh
2016-01-01
This paper develops a complete control scheme for the Modular Multilevel Converter (MMC) in a STATCOM application. The focus is laid on the internal balancing of the converter and its reliable operation under internal mismatches as well as under external unbalanced conditions. The leg energy...... and the simulation results verified the capability to provide maximum reactive power to the AC grid while maintaining internal balance through the individual control of each arm energy level....... controller ensures that the sum of the capacitor voltages of each phase are equal. An intuitive arm energy controller is also implemented which allows the decoupled control of the energy levels of every arm. The control performance of the STATCOM was evaluated under asymmetrical grid faults...
Energy Technology Data Exchange (ETDEWEB)
Machado Neto, Lauro de Vilhena Brandao [Pontificia Universidade Catolica de Minas Gerais (PUC-Minas), Belo Horizonte, MG (Brazil); Cabral, Claudia Valeria Tavora; Oliveira Filho, Delly [Universidade Federal de Vicosa (UFV), MG (Brazil); Diniz, Antonia Sonia Alves Cardoso [Companhia Energetica de Minas Gerais (CEMIG), Belo Horizonte, MG (Brazil); Cortizo, Porfirio Cabaleiro [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil)
2004-07-01
The maximization of the efficiency in the electric energy conversion is essential to the developing of technical and economic viability of photovoltaic solar energy systems. This paper presents the development of an electronic converter with maximum power point tracking for photovoltaic systems applied to rural electrification. The standalone photovoltaic system used is similar to the systems installed by Companhia Energetica de Minas Gerais - CEMIG in the schools of isolated communities, inside the Solar Light Program. Initially were developed test procedures of the equipment used in the system like photovoltaic generators, electronic ballasts, inverters, charge controllers and batteries, covering minimum performance requirements and in compliance with national and international standards, as possible, due to the instrumentation availability. A data acquisition system was assembled to monitoring the photovoltaic system. A simulation of the system was implemented and the aims were to optimize the project and carry out a comparative study with the monitoring results. The converter with maximum power point tracking consists of a direct current converter in the buck configuration and the control algorithm was implemented in a micro controller, being the first results presented here. After finished the prototype, it will be incorporated in the photovoltaic system and will be accomplished a study of the technical and economic viability. The first results of the tests, of the monitoring and of the converter with maximum power point tracking are helping the sustainability of the systems installed by CEMIG, funding the government initiatives in the quality control of equipment and promoting the development of national technology. (author)
Energy Technology Data Exchange (ETDEWEB)
Melicio, R.; Catalao, J.P.S. [Department of Electromechanical Engineering, University of Beira Interior, R. Fonte do Lameiro, 6201-001 Covilha (Portugal); Mendes, V.M.F. [Department of Electrical Engineering and Automation, Instituto Superior de Engenharia de Lisboa, R. Conselheiro Emidio Navarro, 1950-062 Lisbon (Portugal)
2010-10-15
This paper presents new integrated model for variable-speed wind energy conversion systems, considering a more accurate dynamic of the wind turbine, rotor, generator, power converter and filter. Pulse width modulation by space vector modulation associated with sliding mode is used for controlling the power converters. Also, power factor control is introduced at the output of the power converters. Comprehensive performance simulation studies are carried out with matrix, two-level and multilevel power converter topologies in order to adequately assert the system performance. Conclusions are duly drawn. (author)
"Class-Bucks": A Motivational Tool to Encourage Active Student Participation during Lectures
de Jager, T.
2013-01-01
The purpose of this study was to ascertain the influence of an extrinsic motivational tool, "class-bucks," on the possibility of improving first year student-teachers' participation in active learning at Tshwane University of Technology in South Africa. Research participants (n=289) were divided into four classes and engaged in this…
MODEL PREDICTIVE CONTROL FOR PHOTOVOLTAIC STATION MAXIMUM POWER POINT TRACKING SYSTEM
Directory of Open Access Journals (Sweden)
I. Elzein
2015-01-01
Full Text Available The purpose of this paper is to present an alternative maximum power point tracking, MPPT, algorithm for a photovoltaic module, PVM, to produce the maximum power, Pmax, using the optimal duty ratio, D, for different types of converters and load matching.We present a state-based approach to the design of the maximum power point tracker for a stand-alone photovoltaic power generation system. The system under consideration consists of a solar array with nonlinear time-varying characteristics, a step-up converter with appropriate filter.The proposed algorithm has the advantages of maximizing the efficiency of the power utilization, can be integrated to other MPPT algorithms without affecting the PVM performance, is excellent for Real-Time applications and is a robust analytical method, different from the traditional MPPT algorithms which are more based on trial and error, or comparisons between present and past states. The procedure to calculate the optimal duty ratio for a buck, boost and buck-boost converters, to transfer the maximum power from a PVM to a load, is presented in the paper. Additionally, the existence and uniqueness of optimal internal impedance, to transfer the maximum power from a photovoltaic module using load matching, is proved.
Graphical Evaluation of Time-Delay Compensation Techniques for Digitally Controlled Converters
DEFF Research Database (Denmark)
Lu, Minghui; Wang, Xiongfei; Loh, Poh Chiang
2018-01-01
A main design constraint of the digitally controlled power electronics converters is the time delay of control systems, which may lead to the reduced control loop bandwidth and even unstable dynamics. Numerous time-delay compensation methods have been developed, of which the model-free schemes...
Digitally-controlled PC-interfaced Boost Converter for Educational Purposes
DEFF Research Database (Denmark)
Ljusev, Petar; Andersen, Michael A. E.
2004-01-01
This paper describes implementation of a simple digital PID control algorithm for a boost converter using a cheap fixed-point 8-bit microcontroller. Serial communication to a PC server program is established for easier downloading of compensator parameters and current and voltage waveform...
Peña Marrero, Liván
2008-01-01
En este trabajo se evalúa la efectividad de una modificación diseñada por el autor a la técnica de pulgarización del dedo índice descrita por Dieter Buck-Gramcko para el tratamiento de las hipoplasias y aplasias del pulgar. Se realizó un estudio prospectivo longitudinal en 17 pacientes distribuidos en dos grupos. El grupo A estuvo constituido por 9 pacientes (10 manos operadas) a quienes se le aplicó como tratamiento la técnica original de Buck-Gramcko. El grupo B estuvo integrado por 8 pacie...
Enhanced DC-Link Capacitor Voltage Balancing Control of DC–AC Multilevel Multileg Converters
DEFF Research Database (Denmark)
Busquets-Monge, Sergio; Maheshwari, Ram Krishan; Nicolas-Apruzzese, Joan
2015-01-01
This paper presents a capacitor voltage balancing control applicable to any multilevel dc–ac converter formed by a single set of series-connected capacitors implementing the dc link and semiconductor devices, such as the diode-clamped topology. The control is defined for any number of dc-link vol......This paper presents a capacitor voltage balancing control applicable to any multilevel dc–ac converter formed by a single set of series-connected capacitors implementing the dc link and semiconductor devices, such as the diode-clamped topology. The control is defined for any number of dc...
Control of improved full-bridge three-level DC/DC converter for wind turbines in a DC grid
DEFF Research Database (Denmark)
Deng, Fujin; Chen, Zhe
2013-01-01
transformer in the IFBTL dc/dc converter. A modulation strategy, including two operation modes, is proposed for the IFBTL dc/dc converter. Then, a voltage balancing control strategy is proposed for the IFBTL dc/dc converter. Furthermore, the control of the wind turbine based on the IFBTL dc/dc converter......This paper presents an improved full-bridge three-level (IFBTL) dc/dc converter for a wind turbine in a dc grid by inserting a passive filter into the dc/dc converter to improve the performance of the converter. The passive filter can effectively reduce the voltage stress of the medium frequency...
Improved Control Strategy for T-type Isolated DC/DC Converters
DEFF Research Database (Denmark)
Liu, Dong; Deng, Fujin; Wang, Yanbo
2017-01-01
T-type isolated DC/DC converters have recently attracted attention due to their numerous advantages, including few components, low cost, and symmetrical operation of transformers. This study proposes an improved control strategy for increasing the efficiency of T-type isolated DC/DC converters....... Under the proposed strategy, the primary circulating current flows through the auxiliary switches (metal–oxide–semiconductor field-effect transistors) instead of their body diodes in free-wheeling periods. Such feature can reduce conduction losses, thereby improving the efficiency of T-type isolated DC...
El-Desoky, N I; Hashem, N M; Elkomy, A; Abo-Elezz, Z R
2017-09-01
Exposure of rabbit bucks to summer heat stress reduces their homeostasis and semen quality leading to a temporal subfertility. The potentiality of ethanolic extract of Moringa oleifera leaves (M. oleifera ethanolic extract (MLEE)) to reduce negative impacts of heat stress on physiological and semen quality traits was investigated. A total of 28 adult V-line rabbit bucks were randomly distributed among four experimental groups of seven rabbits each. The first group received water (placebo) and served as a control (M0). The other three groups were given orally MLEE at levels of 50 (M50), 100 (M100) and 150 (M150) mg/kg BW every other day for 12 consecutive weeks during the summer season. Chemical constituents of MLEE were detected by gas chromatography/MS. During the experimental period, ambient temperature and relative humidity were recorded daily and were used to estimate temperature and humidity index. Feed intake, BW, rectal temperature were recorded and blood serum biochemical attributes were determined. Semen samples were collected weekly and were analyzed for semen quality traits. Results showed that MLEE contained high percentages of long-chain fatty acids and antioxidant agents. Feed intake and BW were not affected significantly by the treatment, however rectal temperature was decreased significantly by 0.42°C, 0.24°C and 0.40°C in the M50, M100 and M150 groups, respectively, compared with the M0 group. Treatment with 50 mg/kg BW increased concentration of serum albumin (115%; P<0.05), total antioxidant capacity (132%; P<0.05) and testosterone (160%; P=0.098) as well as seminal plasma initial fructose (127%; P=0.092) compared with the control group. Compared with the control, MLEE supplementation with 50, 100 and 150 mg/kg BW increased significantly sperm concentration by 118%, 151% and 158%, sperm progressive motility by 117%, 120% and 118%, sperm viability by 129%, 137% and 127%, sperm normal morphology by 114%, 113% and 114%, intact acrosome sperm by
Modeling and Control of Primary Parallel Isolated Boost Converter
DEFF Research Database (Denmark)
Mira Albert, Maria del Carmen; Hernandez Botella, Juan Carlos; Sen, Gökhan
2012-01-01
In this paper state space modeling and closed loop controlled operation have been presented for primary parallel isolated boost converter (PPIBC) topology as a battery charging unit. Parasitic resistances have been included to have an accurate dynamic model. The accuracy of the model has been...
Evolution of the SPS Power Converter Controls towards the LHC Era
Brazier, J.C.L.; Semanaz, P.
2001-01-01
By the end of the nineties, the power converter control system (Mugef) of the CERN proton accelerator (SPS) had undergone a complete modernization. This resulted in newly developed hardware for function generation, measurement and I/O in a VME environment, under the LynxOS real-time operating system. This has provided a platform on which extensions can be developed for future operation in the Large Hadron Collider (LHC) era. This paper describes some of these extensions, in particular a fast Surveillance and Interlock system for monitoring the power converter output currents. This will be mandatory for the safe operation of the SPS transfer lines TI2 & TI8 to LHC and for similar applications in the future. The strategies employed to cope with various failure modes of the power converters and the timely activation of the interlock are outlined. The new SPS controls infrastructure now under development, will give rise to new modes of operation for the Mugef systems. Integration with the proposed middleware ...
Allen, M. Brady; Burkhardt, Jeanette; Munz, Carrie; Connolly, Patrick J.
2012-01-01
We assessed the physical and biotic conditions in the part of Buck Creek, Washington, potentially accessible to anadromous fishes. This creek is a major tributary to the White Salmon River upstream of Condit Dam, which was breached in October 2011. Habitat and fish populations were characterized in four stream reaches. Reach breaks were based on stream gradient, water withdrawals, and fish barriers. Buck Creek generally was confined, with a single straight channel and low sinuosity. Boulders and cobble were the dominant stream substrate, with limited gravel available for spawning. Large-cobble riffles were 83 percent of the available fish habitat. Pools, comprising 15 percent of the surface area, mostly were formed by bedrock with little instream cover and low complexity. Instream wood averaged 6—10 pieces per 100 meters, 80 percent of which was less than 50 centimeters in diameter. Water temperature in Buck Creek rarely exceeded 16 degrees Celsius and did so for only 1 day at river kilometer (rkm) 3 and 11 days at rkm 0.2 in late July and early August 2009. The maximum temperature recorded was 17.2 degrees Celsius at rkm 0.2 on August 2, 2009. Minimum summer discharge in Buck Creek was 3.3 cubic feet per second downstream of an irrigation diversion (rkm 3.1) and 7.7 cubic feet per second at its confluence with the White Salmon River. Rainbow trout (Oncorhynchus mykiss) was the dominant fish species in all reaches. The abundance of age-1 or older rainbow trout was similar between reaches. However, in 2009 and 2010, the greatest abundance of age-0 rainbow trout (8 fish per meter) was in the most downstream reach. These analyses in Buck Creek are important for understanding the factors that may limit fish abundance and productivity, and they will help identify and prioritize potential restoration actions. The data collected constitute baseline information of pre-dam removal conditions that will allow assessment of changes in fish populations now that Condit Dam has
Directory of Open Access Journals (Sweden)
Sun Zhenchuan
2017-01-01
Full Text Available Constant value control of the DC-bus voltage is a essential problem of the control system of the DC microgrids. DC-DC converters are applied in parallel to realize the transform of energy from the distributed generations (DGs to the DC-bus. Droop control methods are applied to the DC-bus voltage while PI controllers are used in controlling the duty ratios of the converters. This method may bring out the slow response speed of the system accompanied by the large ripple of the voltage. The slide mode variable structure control can speed up the response and reduce the ripple of the voltage as well. In the traditional slide mode control based on the proportion switching function, the denominator of the transfer function of the controlled plant is a second-order characteristic polynomial without the constant term. The denominators of the transfer functions of the buck DC-DC converters contain the constant terms. The designing of the parameters of the slide mode control based on the proportion switching function is analyzed based on mathematics deductions. Simulation results show that the selected parameters can not only speed up the response of the system but also greatly reduce the ripple of the voltage.
Modeling and Control of DC/DC Boost Converter using K-Factor Control for MPPT of Solar PV System
DEFF Research Database (Denmark)
Vangari, Adithya; Haribabu, Divyanagalakshmi; Sakamuri, Jayachandra N.
2015-01-01
This paper is focused on the design of a controller for the DC/DC boost converter using K factor control, which is based on modified PI control method, for maximum power point tracking (MPPT) of solar PV system. A mathematical model for boost converter based on small signal averaging approach...... is presented. Design of the passive elements of the boost converter as per the system specifications is also illustrated. The performance of the proposed K factor control method is verified with the simulations for MPPT on solar PV system at different atmospheric conditions. A new circuit based model for solar...... PV array, which includes the effect of solar insolation and temperature on PV array output, for the application in power system transient simulations, is also presented. The performance of the PV array model is verified with simulations at different atmospheric conditions. A 160W PV module from BP...
Analysis of an AC-DC full-controlled converter supplying two DC-Series-Motor loads
International Nuclear Information System (INIS)
Al-Hindawi, Mohammed M.; Al-Turki, Yusuf A.; Al-Subaie, Obaid T.
2000-01-01
Phase-controlled converters are widely used because these converters are simple, less expensive, reliable, and do not require any communication circuit. Series motors are extensively used in many applications that require both high starting torque and essentially constant horse power. This paper is concerned with the detailed study of the performance characteristics of an AC-DC full-controlled converter supplying two DC-series-motor loads. The converter loads combination is simulated on a digital computer. Different modes of operation (continuous and discontinuous converter currents) are considered. The critical firing angle at which the mode of operation changes from one mode to another is deduced. The performance characteristics such input power factor, supply current distortion factor, supply current fundamental power factor, torque speed, and motor current ripple factor have been derived and studied for both constant firing angle and constant load factor have been derived and studied for both constant firing angle and constant load power of one motor. Waveforms for each load current and converter current are investigated for different modes of operation. (author)
Optimization of Overtopping Wave Energy Converters by Geometry Control
DEFF Research Database (Denmark)
Victor, L.; Troch, P.; Kofoed, Jens Peter
2011-01-01
In this paper, the results of a study on the effects of geometry control on the performance of overtopping wave energy converters with a simple geometry built in coastal structures (simple OWECs) are presented. Empirical formulae, derived based on experimental tests on simple OWECs with varying...
Design, control and application of modular multilevel converters for HVDC transmission systems
Sharifabadi, Kamran; Nee, Hans-Peter; Norrga, Staffan; Teodorescu, Remus
2016-01-01
Design, Control and Application of Modular Multilevel Converters for HVDC Transmission Systems is a comprehensive guide to semiconductor technologies applicable for MMC design, component sizing control, modulation, and application of the MMC technology for HVDC transmission. Separated into three distinct parts, the first offers an overview of MMC technology, including information on converter component sizing, Control and Communication, Protection and Fault Management, and Generic Modelling and Simulation. The second covers the applications of MMC in offshore WPP, including planning, technical and economic requirements and optimization options, fault management, dynamic and transient stability. Finally, the third chapter explores the applications of MMC in HVDC transmission and Multi Terminal configurations, including Supergrids.
Cascaded resonant bridge converters
Stuart, Thomas A. (Inventor)
1989-01-01
A converter for converting a low voltage direct current power source to a higher voltage, high frequency alternating current output for use in an electrical system where it is desired to use low weight cables and other circuit elements. The converter has a first stage series resonant (Schwarz) converter which converts the direct current power source to an alternating current by means of switching elements that are operated by a variable frequency voltage regulator, a transformer to step up the voltage of the alternating current, and a rectifier bridge to convert the alternating current to a direct current first stage output. The converter further has a second stage series resonant (Schwarz) converter which is connected in series to the first stage converter to receive its direct current output and convert it to a second stage high frequency alternating current output by means of switching elements that are operated by a fixed frequency oscillator. The voltage of the second stage output is controlled at a relatively constant value by controlling the first stage output voltage, which is accomplished by controlling the frequency of the first stage variable frequency voltage controller in response to second stage voltage. Fault tolerance in the event of a load short circuit is provided by making the operation of the first stage variable frequency voltage controller responsive to first and second stage current limiting devices. The second stage output is connected to a rectifier bridge whose output is connected to the input of the second stage to provide good regulation of output voltage wave form at low system loads.
Roes, M.G.L.; Duarte, J.L.; Hendrix, M.A.M.
2011-01-01
Feedback sensor isolation is often an expensive necessity in power converters, for reasons of safety and electromagnetic compatibility. A disturbance observer-based control strategy for a dual-output resonant converter is proposed to overcome this problem. Current control of two LED loads is
Roes, M.G.L.; Duarte, J.L.; Hendrix, M.A.M.
2010-01-01
Feedback sensor isolation is often an expensive necessity in power converters, for reasons of safety and electromagnetic compatibility. A disturbance observer-based control strategy for a dual-output resonant converter is proposed to overcome this problem. Current control of two LED loads is
Stability Analysis and Trigger Control of LLC Resonant Converter for a Wide Operational Range
Directory of Open Access Journals (Sweden)
Zhijian Fang
2017-09-01
Full Text Available The gain of a LLC resonant converter can vary with the loads that can be used to improve the efficiency and power density for some special applications, where the maximum gain does not apply at the heaviest loads. However, nonlinear gain characteristics can make the converters unstable during a major disturbance. In this paper, the stability of an LLC resonant converter during a major disturbance is studied and a trigger control scheme is proposed to improve the converter’s stability by extending the converter’s operational range. Through in-depth analysis of the gain curve of the LLC resonant converter, we find that the switching frequency range is one of the key factors determining the system’s stability performance. The same result is also obtained from a mathematical point of view by utilizing the mixed potential function method. Then a trigger control method is proposed to make the LLC resonant converter stable even during a major disturbance, which can be used to extend the converter’s operational range. Finally, experimental results are given to verify the analysis and proposed control scheme.
Power Control of Grid-Connected Converters Under Unbalanced Voltage Conditions
Czech Academy of Sciences Publication Activity Database
Valouch, Viktor; Bejvl, Martin; Šimek, Petr; Škramlík, Jiří
2015-01-01
Roč. 62, č. 7 (2015), s. 4241-4248 ISSN 0278-0046 Institutional support: RVO:61388998 Keywords : converter * current control * current peaks Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 6.383, year: 2015
Fertility potential of rabbit bucks fed maize-based diets containing graded levels of fumonisin B1
Directory of Open Access Journals (Sweden)
Kingsley Idahor
2012-07-01
Full Text Available Fumonisin B1-contaminated maize-based diets have been reported to be mycotoxic in animal species, yet more validated data and biomarkers are needed. In this study, Fumonisin B1 (FB1 infected yellow-maize was used to formulate Diets 1, 2 and 3, containing 1,700, 1,800 and 1,900µg FB1/kg diet, respectively. Sixty sexually matured bucks and does were used, but only the bucks were fed the FB1-contaminated diets for eight weeks. At the end of the feeding trial, the treated bucks were mated to the dry does that were fed FB1-free yellow maize-based diet. Effects on testis and live weight, feed utilisation, conception rate, embryo development and spermatozoa production per gram testis were monitored. Results indicated significant depression (P<0.05 in feed intake, from 546.77±12.09g/week in Diet 1 with the lowest FB1 concentration, to 509.84±21.98g/week in Diet 3 with the highest FB1 concentration in the diets. Weight gain was drastically reduced (P<0.05 from 34.13±9.32g/week in Diet 1 to 20.38±22.13g/week in Diet 3. Meanwhile, some of the untreated does were pregnant in all the treatments, indicating that FB1 concentration at 2.0mg/kg diet may not be spermaticidal and there were no abnormalities in the embryos. It was observed that the paired testis weight value in Diet 1 (3.06±0.31 was not significantly different (P>0.05 from that of Diet 3 (2.94±0.23. The testicular elements were distorted by the dietary FB1, but did not follow a definite pattern. Spermatozoa production per gram testis values (31.1 – 37.3 x 106 recorded were much higher than 24 x 106 for a healthy rabbit buck. Consequently, FB1 concentration < 2.0mg/kg diet may not affect the fertility potentials of bucks orally dosed for a relatively short period. This observation further elucidates earlier discoveries that FB1 is not a reproductive toxicant. Hence, the United States Food and Drug Administration proposed a guideline of 2.0mg total fumonisins/kg diet, to be adopted with
International Nuclear Information System (INIS)
Gusakovskii, K. B.; Zmaznov, E. Yu.; Katantsev, S. V.; Mazurenko, A. K.; Mestergazi, V. A.; Prochan, G. G.; Funtikova, S. F.
2006-01-01
The experience in the installation of modern digital systems for controlling converter units at the Vyborg converter substation on the basis of advanced microprocessor devices is considered. It is shown that debugging of a control and protection system on mathematical and physical models does not guarantee optimum control of actual converter devices. Examples of advancing the control and protection system are described, the necessity for which has become obvious in tests of actual equipment. Comparison of oscillograms of processes before optimization of the control system and after its optimization and adjustment shows that the digital control system makes it possible to improve substantially the algorithms of control and protection in the short term and without changing the hardware component
Directory of Open Access Journals (Sweden)
Bruno Pinto Coelho Fontes
2009-03-01
Full Text Available OBJETIVO: justificar a reconstrução da pars interarticularis pela técnica modificada de Buck como método efetivo no tratamento de lombalgia por espondilólise ou espondilolistese tipo 1, refratárias ao tratamento conservador. MÉTODOS: avaliação retrospectiva de oito pacientes com idade entre 11 e 34 anos, operados e acompanhados no período de outubro de 2004 a maio de 2008 com a técnica de Buck utilizando-se parafusos canulados de titânio. Nenhum paciente foi imobilizado no pós-operatório. Os pacientes foram selecionados após serem submetidos a estudos por imagem utilizando radiografias e ressonância magnética. Também foram avaliados no pós-operatório, segundo os critérios de Henderson e quanto à satisfação com o tratamento, assim como o índice de consolidação. RESULTADOS: sete pacientes foram classificados como excelentes, retornando ao nível de prática esportiva e laboral prévia. Dentre eles, um evoluiu com parestesia transitória, com recuperação completa. A oitava paciente apresentou uma pseudartrose bilateral, mas com bom resultado do ponto de vista clínico. Todos os pacientes ficaram satisfeitos com o resultado. CONCLUSÃO: a reconstrução ístmica com parafusos de titânio atingiu excelentes resultados ao aliar biomecânica estável, dissecção mínima da musculatura, com preservação da anatomia e mobilidade do segmento.OBJETIVO: justificar la reconstrucción de la pars interarticularis por la técnica modificada de Buck como método efectivo en el tratamiento de la lumbalgia por espondilosis o espondilolistesis tipo 1, refractarias al tratamiento conservador. MÉTODOS: evaluación retrospectiva de ocho pacientes con edad entre 11 a 34 años, operados y acompañados en el periodo de Octubre de 2004 hasta Mayo de 2008 con la técnica de Buck usando tornillos canulados de titanio. Ningún paciente fue inmovilizado en el postoperatorio. Los pacientes fueron seleccionados después de ser sometidos a
MPPT for Photovoltaic System Using Nonlinear Controller
Directory of Open Access Journals (Sweden)
Ramsha Iftikhar
2018-01-01
Full Text Available Photovoltaic (PV system generates energy that varies with the variation in environmental conditions such as temperature and solar radiation. To cope up with the ever increasing demand of energy, the PV system must operate at maximum power point (MPP, which changes with load as well as weather conditions. This paper proposes a nonlinear backstepping controller to harvest maximum power from a PV array using DC-DC buck converter. A regression plane is formulated after collecting the data of the PV array from its characteristic curves to provide the reference voltage to track MPP. Asymptotic stability of the system is proved using Lyapunov stability criteria. The simulation results validate the rapid tracking and efficient performance of the controller. For further validation of the results, it also provides a comparison of the proposed controller with conventional perturb and observe (P&O and fuzzy logic-based controller (FLBC under abrupt changes in environmental conditions.
Ancillary Frequency Control of Direct Drive Full-Scale Converter Based Wind Power Plants
DEFF Research Database (Denmark)
Hu, Weihao; Su, Chi; Fang, Jiakun
2013-01-01
This paper presents a simulation model of a wind power plant based on a MW-level variable speed wind turbine with a full-scale back-to-back power converter developed in the simulation tool of DIgSILENT Power Factory. Three different kinds of ancillary frequency control strategies, namely inertia...... control strategies are effective means for providing ancillary frequency control of variable speed wind turbines with full-scale back-to-back power converters....... emulation, primary frequency control and secondary frequency control, are proposed in order to improve the frequency stability of power systems. The modified IEEE 39-bus test system with a large-scale wind power penetration is chosen as the studied power system. Simulation results show that the proposed...
Directory of Open Access Journals (Sweden)
A. Mohammadpour
2009-12-01
Full Text Available Robust performance controller design for duty-cycle controlled series resonant converter (SRC is proposed in this paper. The uncertainties of the converter are analyzed with load variation and power circuit components tolerances are taken into consideration. Additionally, a nominal performance (NP controller is designed. Closed-loop system is simulated with Orcad and simulation results of robust controller are compared with nominal performance controller. Although nominal performance controller has better performance for nominal plant, the robust performance controller is advantageous in dealing with uncertainties.
Backscatter 0.5m TIFF Mosaic of St. Croix (Buck Island), US Virgin Islands, 2004
National Oceanic and Atmospheric Administration, Department of Commerce — This image represents a 0.5 meter resolution backscatter mosaic of the north shore of Buck Island, St. Croix, US Virgin Islands. NOAA's NOS/NCCOS/CCMA Biogeography...
Converter topologies and control
Energy Technology Data Exchange (ETDEWEB)
Rodriguez, Fernando; Qin, Hengsi; Chapman, Patrick
2018-05-01
An inverter includes a transformer that includes a first winding, a second winding, and a third winding, a DC-AC inverter electrically coupled to the first winding of the transformer, a cycloconverter electrically coupled to the second winding of the transformer, an active filter electrically coupled to the third winding of the transformer. The DC-AC inverter is adapted to convert the input DC waveform to an AC waveform delivered to the transformer at the first winding. The cycloconverter is adapted to convert an AC waveform received at the second winding of the transformer to the output AC waveform having a grid frequency of the AC grid. The active filter is adapted to sink and source power with one or more energy storage devices based on a mismatch in power between the DC source and the AC grid.
The performance of the DC motor by the PID controlling PWM DC-DC boost converter
Can, Erol; Sayan, Hasan Hüseyin
2017-01-01
This paper presents the PID controlling direct current (DC) to the direct current boost converter feds DC motor which has a 3.68 kW and 240 V of DC voltage input on its characteristics. What is first formed is the boost converter mathematical model at the design stage. Secondly, a mathematical model of the DC motor is created so that the boost converter with the machine can be established and modeled at the Matlab Simulink. The PID controller is considered for arranging a pulse width modulati...
International Nuclear Information System (INIS)
Fan, YaJun; Mu, AnLe; Ma, Tao
2016-01-01
Highlights: • Point absorber wave energy converter is presented. • Piston pump module captures and converts wave energy. • Hydraulic accumulator stores/releases the surplus energy. • Fuzzy controller adjusts the displacement of hydraulic motor. • Generator outputs meet the electricity demand precisely. - Abstract: In this paper, a point absorber wave energy converter combined with offshore wind turbine is proposed. In the system, the wave energy is captured and converted into hydraulic energy by a piston pump module, which is combined with a wind turbine floating platform, and then the hydraulic energy is converted into electricity energy by a variable displacement hydraulic motor and induction generator. In order to smooth and stabilize the captured wave energy, a hydraulic accumulator is applied to store and release the excess energy. In order to meet the demand power a fuzzy controller is designed to adjust the displacement of hydraulic motor and controlled the output power. Simulation under irregular wave condition has been carried out to verify the validity of the mathematical model and the effectiveness of the controller strategy. The results show that the wave energy converter system could deliver the required electricity power precisely as the motor output torque is controlled. The accumulator could damp out all the fluctuations in output power, so the wave energy would become a dispatchable power source.
Impedance source power electronic converters
Liu, Yushan; Ge, Baoming; Blaabjerg, Frede; Ellabban, Omar; Loh, Poh Chiang
2016-01-01
Impedance Source Power Electronic Converters brings together state of the art knowledge and cutting edge techniques in various stages of research related to the ever more popular impedance source converters/inverters. Significant research efforts are underway to develop commercially viable and technically feasible, efficient and reliable power converters for renewable energy, electric transportation and for various industrial applications. This book provides a detailed understanding of the concepts, designs, controls, and application demonstrations of the impedance source converters/inverters. Key features: Comprehensive analysis of the impedance source converter/inverter topologies, including typical topologies and derived topologies. Fully explains the design and control techniques of impedance source converters/inverters, including hardware design and control parameter design for corresponding control methods. Presents the latest power conversion solutions that aim to advance the role of pow...
Energy Technology Data Exchange (ETDEWEB)
Tom, Nathan; Lawson, Michael; Yu, Yi-Hsiang; Wright, Alan
2015-09-09
The aim of this paper is to present a novel wave energy converter device concept that is being developed at the National Renewable Energy Laboratory. The proposed concept combines an oscillating surge wave energy converter with active control surfaces. These active control surfaces allow for the device geometry to be altered, which leads to changes in the hydrodynamic properties. The device geometry will be controlled on a sea state time scale and combined with wave-to-wave power-take-off control to maximize power capture, increase capacity factor, and reduce design loads. The paper begins with a traditional linear frequency domain analysis of the device performance. Performance sensitivity to foil pitch angle, the number of activated foils, and foil cross section geometry is presented to illustrate the current design decisions; however, it is understood from previous studies that modeling of current oscillating wave energy converter designs requires the consideration of nonlinear hydrodynamics and viscous drag forces. In response, a nonlinear model is presented that highlights the shortcomings of the linear frequency domain analysis and increases the precision in predicted performance.
Design and Implementation of Digital Current Mode Controller for DC-DC Converters
DEFF Research Database (Denmark)
Taeed, Fazel
to be regulated by a closed-loop controller. The Peak Current Mode Control (PCMC) is one of the most promising control methods for dc-dc converters. It has been known for high bandwidth (speed), and inherent current protection. Increasing the controller bandwidth decreases the output filter size and cost. Analog...
Design of Current-Controller with PR-regulator for LCL-Filter Based Grid-Connected Converter
DEFF Research Database (Denmark)
Zeng, Guohong; Rasmussen, Tonny Wederberg
2010-01-01
In the application of LCL-filter based converters, the structure and parameters of current-controller is very important for the system stability and output current quality. This paper presents a filter-capacitor current feedback control scheme for grid-connected converter. The controller...... is consisted of a proportional-resonance regulator and a proportional regulator. Unlike the existing control strategy with unit capacitor current feedback, the proposed method applies the proportional regulator to the feedback path, which can decouple these two regulators, and simplify the tuning process...... of the control strategy and the proposed current controller design method are verified by the simulation results of a 50kVA grid-connected inverter....
Automatic control and monitoring of the MIT fission converter beam
International Nuclear Information System (INIS)
Wilson, B.A.; Riley, K.J.; Harling, O.K.
2000-01-01
An automated control and monitoring system for the new MIT high intensity epithermal neutron irradiation facility has been designed and constructed. The neutron beam is monitored with fission counters located at the periphery of the beam near the patient position. Control of the beam is accomplished with redundant Programmable Logic Controllers (PLCs). These industrial controllers open and close the three shutters of the Fission Converter Beam. The control system uses a series of robust components to assure that the prescribed fluence is delivered. This paper discusses the design and implementation of this system. (author)
DEFF Research Database (Denmark)
Okumus, Sinan; Fan, Lin; Nour, Yasser
2018-01-01
Most of todays power converters are based on power semiconductors, which are built in vertical power semiconductor processes. These devices result in limited packaging possibilities, which lead to physically long galvanic connections and therefore high external electromagnetic fields. These fields...
Impedance Source Power Electronic Converters
DEFF Research Database (Denmark)
Liu, Yushan; Abu-Rub, Haitham; Ge, Baoming
Impedance Source Power Electronic Converters brings together state of the art knowledge and cutting edge techniques in various stages of research related to the ever more popular impedance source converters/inverters. Significant research efforts are underway to develop commercially viable...... and technically feasible, efficient and reliable power converters for renewable energy, electric transportation and for various industrial applications. This book provides a detailed understanding of the concepts, designs, controls, and application demonstrations of the impedance source converters/inverters. Key...... features: Comprehensive analysis of the impedance source converter/inverter topologies, including typical topologies and derived topologies. Fully explains the design and control techniques of impedance source converters/inverters, including hardware design and control parameter design for corresponding...
A Practical Core Loss Model for Filter Inductors of Power Electronic Converters
DEFF Research Database (Denmark)
Matsumori, Hiroaki; Shimizu, Toshihisa; Wang, Xiongfei
2018-01-01
This paper proposes a core loss model for filter inductors of power electronic converters. The model allows a computationally efficient analysis on the core loss of the inductor under the square voltage excitation and the premagnetization condition. First, the core loss of the filter inductor under...... buck chopper excitation is evaluated with the proposed model and compared with the conventional methods. The comparison shows that the proposed method results in a better core loss prediction under the premagnetized condition than that of conventional alternatives. Then, the core loss of the filter...... inductor with the pulsewidth modulated inverter excitation is evaluated, which shows that the proposed model not only accurately predicts the core loss but also identifies the hysteresis loss part. These results demonstrate that the approach can further be used for the development of magnetic materials...
Nonlinear Control Structure of Grid Connected Modular Multilevel Converters
DEFF Research Database (Denmark)
Hajizadeh, Amin; Norum, Lars; Ahadpour Shal, Alireza
2017-01-01
in the prediction step in order to preserve the stochastic characteristics of a nonlinear system. In order to design adaptive robust control strategy and nonlinear observer, mathematical model of MMC using rotating d-q theory has been used. Digital time-domain simulation studies are carried out in the Matlab......This paper implements nonlinear control structure based on Adaptive Fuzzy Sliding Mode (AFSM) Current Control and Unscented Kalman Filter (UKF) to estimate the capacitor voltages from the measurement of arm currents of Modular Multilevel Converter (MMC). UKF use nonlinear unscented transforms....../Simulink environment to verify the performance of the overall proposed control structure during different case studies....
DEFF Research Database (Denmark)
Yang, Yongheng; Zhou, Keliang; Blaabjerg, Frede
2015-01-01
It is mandatory for grid-connected power converters to synchronize the feed-in currents with the grid. Moreover, the power converters should produce feed-in currents with low total harmonic distortions according to the demands, by employing advanced current controllers, e.g., Proportional Resonant...... deviations. Experiments on a single-phase grid-connected inverter system are presented, which have verified the proposals and also the effectiveness of the frequency adaptive current controllers....... (PR) and Repetitive Controllers (RC). The synchronization is actually to detect the instantaneous grid information (e.g., frequency and phase of the grid voltage) for the current control, which is commonly performed by a Phase-Locked-Loop (PLL) system. As a consequence, harmonics and deviations...
Directory of Open Access Journals (Sweden)
VENMATHI, M.
2016-02-01
Full Text Available In this paper, a new four-port DC-DC converter topology is proposed to interface renewable energy sources and the load along with the energy storage device. The proposed four-port SEPIC/ZETA bidirectional converter (FP-SEPIC/ZETA BDC converter comprises an isolated output port with two unidirectional and one bidirectional input ports. This converter topology is obtained by the fusion of SEPIC/ZETA BDC and full-bridge converter. This converter topology ensures the non-reversal of output voltage hence it is preferred mostly for battery charging applications. In this work, photovoltaic (PV source is considered and the power balance in the system is achieved by means of distributed maximum power point tracking (DMPPT in the PV ports. The centralized controller is implemented using fuzzy logic controller (FLC and the performance is compared with conventional proportional integral (PI controller. The results offer useful information to obtain the desired output under line and load regulations. Experimental results are also provided to validate the simulation results.
Passivity-Based Control by Series/Parallel Damping of Single-Phase PWM Voltage Source Converter
del Puerto Flores, Dunstano; Scherpen, Jacqueline; Liserre, Marco; de Vries, Martijn M. J.; Kransse, Marco J.; Monopoli, Vito Giuseppe
This paper describes a detailed design procedure for passivity-based controllers developed using the Brayton-Moser (BM) framework. Several passivity-based feedback designs are presented for the voltage-source converter, specifically for the H-bridge converter, since nowadays it is one of the
DEFF Research Database (Denmark)
Liu, Wenxin; Guerrero, Josep M.; Kim, Jang Mok
2017-01-01
In this Special Section on Systems of Power Converters: Design, Modeling, Control, and Implementation, we have 11 high-quality papers approved for publication that cover the following three topics. 1) Converter Design and Operation. 2) Subsystem-Level Applications. 3) System-Level Applications...
Directory of Open Access Journals (Sweden)
Andrés Peña Asensio
2018-02-01
Full Text Available This paper addresses the design and analysis of a voltage and frequency control (VFC strategy for full converter (FC-based wind energy conversion systems (WECSs and its applicability for the supply of an isolated load. When supplying an isolated load, the role of the back-to-back converters in the FC must change with respect to a grid-connected application. Voltage and frequency are established by the FC line side converter (LSC, while the generator side converter (GSC is responsible for maintaining constant voltage in the DC link. Thus, the roles of the converters in the WECS are inverted. Under such control strategies, the LSC will automatically supply the load power and hence, in order to maintain a stable operation of the WECS, the wind turbine (WT power must also be controlled in a load-following strategy. The proposed VFC is fully modelled and a stability analysis is performed. Then, the operation of the WECS under the proposed VFC is simulated and tested on a real-time test bench, demonstrating the performance of the VFC for the isolated operation of the WECS.
A Predictive Power Control Strategy for DFIGs Based on a Wind Energy Converter System
Directory of Open Access Journals (Sweden)
Xiaoliang Yang
2017-07-01
Full Text Available A feasible control strategy is proposed to control a doubly fed induction generator based on the wind energy converter system (DFIG-WECS. The main aim is to enhance the steady state and dynamic performance under the condition of the parameter perturbations and external disturbances and to satisfy the stator power response of the system. Within the proposed control method, the control scheme for the rotor side converter (RSC is developed on the model predictive control. Firstly, the self-adaptive reference trajectory is established from the deduced discrete state-space equation of the generator. Then, the rotor voltage is calculated by minimizing the global performance index under the current prediction steps at the sampling instant. Through the control scheme for the grid side converter (GSC and wind turbine, we have re-applied the conventional control. The effectiveness of the proposed control strategy is verified via time domain simulation of a 150 kW-575 V DFIG-WECS using Matlab/Simulink. The simulation result shows that the control of the DFIG with the proposed control method can enhance the steady and dynamic response capability better than the conventional ones when the system faces errors due to the parameter perturbations, external disturbances and the rotor speed.
A high control bandwidth design method for aalborg inverter under weak grid condition
DEFF Research Database (Denmark)
Wu, Weimin; Zhou, Cong; Wang, Houqin
2017-01-01
Aalborg Inverter is a kind of high efficient Buck-Boost inverter. Since it may work in “Buck-Boost” mode, the control bandwidth should be high enough to ensure a good performance under any grid condition. However, during the “Boost” operation, the control bandwidth depends much on the grid...
Development of a Compact Matrix Converter
Directory of Open Access Journals (Sweden)
J. Bauer
2009-01-01
Full Text Available This paper deals with the development of a matrix converter. Matrix converters belong to the category of direct frequency converters. A converter does not contain DC-link and the output voltage is provided by direct switching of voltage from the input phases. This is enabled by 9 bidirectional switches, which are provided by anti-serial connection of 18 IGBT transistors. The absence of a DC-link is great advantage of the matrix converter, but it also increases the requirements on the converter control. For this reason a new prototype of a matrix converter is being developed with sophisticated modern components (FPGA, Power PC equipped in the control part of the converter. The converter will be used for testing new control algorithms and commutation methods.
A Predictive-Control-Based Over-Modulation Method for Conventional Matrix Converters
DEFF Research Database (Denmark)
Zhang, Guanguan; Yang, Jian; Sun, Yao
2018-01-01
To increase the voltage transfer ratio of the matrix converter and improve the input/output current performance simultaneously, an over-modulation method based on predictive control is proposed in this paper, where the weighting factor is selected by an automatic adjusting mechanism, which is able...... to further enhance the system performance promptly. This method has advantages like the maximum voltage transfer ratio can reach 0.987 in the experiments; the total harmonic distortion of the input and output current are reduced, and the losses in the matrix converter are decreased. Moreover, the specific...
Sudhakar, N.; Rajasekar, N.; Akhil, Saya; Jyotheeswara Reddy, K.
2017-11-01
The boost converter is the most desirable DC-DC power converter for renewable energy applications for its favorable continuous input current characteristics. In other hand, these DC-DC converters known as practical nonlinear systems are prone to several types of nonlinear phenomena including bifurcation, quasiperiodicity, intermittency and chaos. These undesirable effects has to be controlled for maintaining normal periodic operation of the converter and to ensure the stability. This paper presents an effective solution to control the chaos in solar fed DC-DC boost converter since the converter experiences wide range of input power variation which leads to chaotic phenomena. Controlling of chaos is significantly achieved using optimal circuit parameters obtained through Nelder-Mead Enhanced Bacterial Foraging Optimization Algorithm. The optimization renders the suitable parameters in minimum computational time. The results are compared with the traditional methods. The obtained results of the proposed system ensures the operation of the converter within the controllable region.
Boost converter with combined control loop for a stand-alone photovoltaic battery charge system
DEFF Research Database (Denmark)
Mira Albert, Maria del Carmen; Knott, Arnold; Thomsen, Ole Cornelius
2013-01-01
frequency avoids perturbations in the load being propagated to the photovoltaic panel and thus deviating the operating point. Linearization of the photovoltaic panel and converter state-space modeling is performed. In order to achieve stable operation under all operating conditions, the photovoltaic panel......The converter control scheme plays an important role in the performance of maximum power point tracking (MPPT) algorithms. In this paper, an input voltage control with double loop for a stand-alone photovoltaic system is designed and tested. The inner current control loop with high crossover...
Directory of Open Access Journals (Sweden)
Zhixiang Ling
2016-09-01
Full Text Available The three-port converter has three H-bridge ports that can interface with three different energy sources and offers the advantages of flexible power transmission, galvanic isolation ability and high power density. The three-port full-bridge converter can be used in electric vehicles as a combined charger that consists of a battery charger and a DC-DC converter. Power transfer occurs between two ports while the third port is isolated, i.e., the average power is zero. The purpose of this paper is to apply an optimal phase shift strategy in isolation control and provide a detailed comparison between traditional phase shift control and optimal phase shift control under the proposed isolation control scheme, including comparison of the zero-voltage-switching range and the root mean square current for the two methods. Based on this analysis, the optimal parameters are selected. The results of simulations and experiments are given to verify the advantages of dual-phase-shift control in isolation control.
Rectifier Current Control for an LLC Resonant Converter Based on a Simplified Linearized Model
Directory of Open Access Journals (Sweden)
Zhijian Fang
2018-03-01
Full Text Available In this paper, a rectifier current control for an LLC resonant converter is proposed, based on a simplified, two-order, linearized model that adds a rectifier current feedback inner loop to improve dynamic performance. Compared to the traditional large-signal model with seven resonant states, this paper utilizes a rectifier current state to represent the characteristics of the resonant states, simplifying the LLC resonant model from seven orders to two orders. Then, the rectifier current feedback inner loop is proposed to increase the control system damping, improving dynamic performance. The modeling and design methodology for the LLC resonant converter are also presented in this paper. A frequency analysis is conducted to verify the accuracy of the simplified model. Finally, a 200 W LLC resonant converter prototype is built to verify the effectiveness of the proposed control strategy. Compared to a traditional single-loop controller, the settling time and voltage droop were reduced from 10.8 ms to 8.6 ms and from 6.8 V to 4.8 V, respectively, using the proposed control strategy.
Directory of Open Access Journals (Sweden)
Taizhou Bei
2014-01-01
Full Text Available Considering the disadvantages of the traditional high-gain DC-DC converter such as big size, high voltage stress of switches, and large input current ripple, a novel high-gain interleaved boost converter with coupled-inductor and switched-capacitor was proposed correspondingly and the operation principle together with the steady-state analysis of this converter was also described. Besides, a new control approach-dynamic sliding mode evolution PWM controller (DSME PWM for the novel topological converter based on both dynamic evolution and sliding mode control was also presented. From the simulation results and experimental validation the proposed converter can fulfill high-gain boost, low ripple of both the input current and the output voltage. Furthermore, MPPT technique can be also achieved in a short time by simulation. The efficiency and stability of the converter proposed in this paper can be improved.
Robust control of boost PFC converter using adaptive PLL for line synchronization
DEFF Research Database (Denmark)
Török, Lajos; Mathe, Laszlo; Munk-Nielsen, Stig
2013-01-01
The continuous development of the digital processing technology made advanced control strategies available for switched-mode power-supply applications. This paper presents the study and implementation of an adaptive Phased-Locked Loop (PLL)-based grid-fault tolerant control of a boost PFC converter...
A suitable model plant for control of the set fuel cell-DC/DC converter
Energy Technology Data Exchange (ETDEWEB)
Andujar, J.M.; Segura, F.; Vasallo, M.J. [Departamento de Ingenieria Electronica, Sistemas Informaticos y Automatica, E.P.S. La Rabida, Universidad de Huelva, Ctra. Huelva - Palos de la Frontera, S/N, 21819 La Rabida - Palos de la Frontera Huelva (Spain)
2008-04-15
In this work a state and transfer function model of the set made up of a proton exchange membrane (PEM) fuel cell and a DC/DC converter is developed. The set is modelled as a plant controlled by the converter duty cycle. In addition to allow setting the plant operating point at any point of its characteristic curve (two interesting points are maximum efficiency and maximum power points), this approach also allows the connection of the fuel cell to other energy generation and storage devices, given that, as they all usually share a single DC bus, a thorough control of the interconnected devices is required. First, the state and transfer function models of the fuel cell and the converter are obtained. Then, both models are related in order to achieve the fuel cell+DC/DC converter set (plant) model. The results of the theoretical developments are validated by simulation on a real fuel cell model. (author)
Nielsen, Dennis; Knott, Arnold; Andersen, Michael A. E.
2014-01-01
A practical solution is presented for the design of a non-isolated high voltage DC/AC power converter. The converter is intended to be used as a class D audio amplifier for a Dielectric Electro Active Polymer (DEAP) transducer. A simple and effective hysteretic control scheme for the converter (buck with fourth- order output filter) is developed and analyzed. The proposed design is verified experimentally by a 125 VAR prototype amplifier, capable of delivering a peak output voltage of 240 V w...
A high performance DC-DC converter with intelligent control for photovoltaic applications
M. Niroomand; M. Sherkat; M. Soheili
2013-01-01
In this paper, a SEPIC (Single-Ended Primary Inductance Converter) with high efficiency has been proposed for photovoltaic applications. In the proposed converter, an auxiliary circuit without any additional switches has been used. The switch works under ZCS and ZVS conditions. No auxiliary switch was added to the circuit, thus any additional drive circuit is not needed. The proposed control system based on fuzzy logic method, has shown the smart accurate and faster tracking of the maximum po...
DEFF Research Database (Denmark)
Klumpner, Christian; Wheeler, P.; Blaabjerg, Frede
2004-01-01
Controlling a converter requires not only a powerful processors but also accurate voltage and current sensors and fast and precise analogue-digital converters, which increase the cost per kW of the assembly, especially in the low power range. A matrix converter requires less transducers than a back...... converters but in two stages (AC/DC/AC) without using energy storage in the intermediary circuit. They also offer the possibility to reduce the number of switches compared to the standard single-stage matrix converter. This paper presents a new method to control a two-stage DPC providing sine-wave in sine...
Control systems for power electronics a practical guide
Patil, Mahesh
2015-01-01
The scope of the book covers most of the aspects as a primer on power electronics starting from a simple diode bridge to a DC-DC convertor using PWM control. The thyristor-bridge and the mechanism of designing a closed loop system are discussed in chapter one, two and three. The concepts are applied in the fourth chapter as a case study for buck converter which uses MOSFETs as switching devices and the closed loop system is elaborated in the fifth chapter. Chapter six is focused on the embedded system basics and the implementation of controls in the digital domain. Chapter seven is a case study of application of an embedded control system for a DC motor. With this book, the reader will find it easy to work on the practical control systems with microcontroller implementation. The core intent of this book is to help gain an accelerated learning path to practical control system engineering and transform control theory to an implementable control system through electronics. Illustrations are provided for most of...
DEFF Research Database (Denmark)
Rivera, M.; Nasir, U.; Tarisciotti, L.
2017-01-01
The classic model predictive control presents a variable switching frequency which could produce high ripple in the controlled waveforms or resonances in the input filter of the matrix converter, affecting the performance of the system. This paper presents two model predictive control strategies...
Design of a hybrid battery charger system fed by a wind-turbine and photovoltaic power generators.
Chang Chien, Jia-Ren; Tseng, Kuo-Ching; Yan, Bo-Yi
2011-03-01
This paper is aimed to develop a digital signal processor (DSP) for controlling a solar cell and wind-turbine hybrid charging system. The DSP consists of solar cells, a wind turbine, a lead acid battery, and a buck-boost converter. The solar cells and wind turbine serve as the system's main power sources and the battery as an energy storage element. The output powers of solar cells and wind turbine have large fluctuations with the weather and climate conditions. These unstable powers can be adjusted by a buck-boost converter and thus the most suitable output powers can be obtained. This study designs a booster by using a dsPIC30F4011 digital signal controller as a core processor. The DSP is controlled by the perturbation and observation methods to obtain an effective energy circuit with a full 100 W charging system. Also, this DSP can, day and night, be easily controlled and charged by a simple program, which can change the state of the system to reach a flexible application based on the reading weather conditions.
Design and Testing of Boost Type DC/DC Converter for DC Motor Control Applications
Samman, Faizal Arya; Akil, Yusri Syam; Noor, Nirwan A.
2017-01-01
in The Proceeding of The 2nd International Symposium on Smart Material and Mechatronics 2015 This paper presents the design and testing of a boost type DC/DC converter circuit, which can be used for DC motor control applications. The Boost converter is designed using DC chopper and DC chopper cascade configurations. The experimental setup was made by connecting the boost converter circuit with four types of DC motor, i.e. self-excited DC motor shunt, series, compound and separately exci...
Luo, Li-Chuan; Bao, De-Chun; Yu, Wu-Qi; Zhang, Zhao-Hua; Ren, Tian-Ling
2016-01-01
It is meaningful to research the Triboelectric Nanogenerators (TENG), which can create electricity anywhere and anytime. There are many researches on the structures and materials of TENG to explain the phenomenon that the maximum voltage is stable and the current is increasing. The output voltage of the TENG is high about 180-400 V, and the output current is small about 39 μA, which the electronic devices directly integration of TENG with Li-ion batteries will result in huge energy loss due to the ultrahigh TENG impedance. A novel interface circuit with the high-voltage buck regulator for TENG is introduced firstly in this paper. The interface circuit can transfer the output signal of the TENG into the signal fit to a lithium ion battery. Through the circuit of the buck regulator, the average output voltage is about 4.0 V and the average output current is about 1.12 mA. Further, the reliability and availability for the lithium ion battery and the circuit are discussed. The interface circuit is simulated using the Cadence software and verified through PCB experiment. The buck regulator can achieve 75% efficiency for the High-Voltage TENG. This will lead to a research hot and industrialization applications.
International Nuclear Information System (INIS)
Melicio, R.; Mendes, V.M.F.; Catalao, J.P.S.
2010-01-01
This paper presents a new integrated model for the simulation of wind energy systems. The proposed model is more realistic and accurate, considering a variable-speed wind turbine, two-mass rotor, permanent magnet synchronous generator (PMSG), different power converter topologies, and filters. Additionally, a new control strategy is proposed for the variable-speed operation of wind turbines with PMSG/full-power converter topology, based on fractional-order controllers. Comprehensive simulation studies are carried out with matrix and multilevel power converter topologies, in order to adequately assert the system performance in what regards the quality of the energy injected into the electric grid. Finally, conclusions are duly drawn.
Energy Technology Data Exchange (ETDEWEB)
Melicio, R.; Catalao, J.P.S. [Department of Electromechanical Engineering, University of Beira Interior, R. Fonte do Lameiro, 6201-001 Covilha (Portugal); Mendes, V.M.F. [Department of Electrical Engineering and Automation, Instituto Superior de Engenharia de Lisboa, R. Conselheiro Emidio Navarro, 1950-062 Lisbon (Portugal)
2010-06-15
This paper presents a new integrated model for the simulation of wind energy systems. The proposed model is more realistic and accurate, considering a variable-speed wind turbine, two-mass rotor, permanent magnet synchronous generator (PMSG), different power converter topologies, and filters. Additionally, a new control strategy is proposed for the variable-speed operation of wind turbines with PMSG/full-power converter topology, based on fractional-order controllers. Comprehensive simulation studies are carried out with matrix and multilevel power converter topologies, in order to adequately assert the system performance in what regards the quality of the energy injected into the electric grid. Finally, conclusions are duly drawn. (author)
Control of modular multilevel converters based on time-scale analysis and orthogonal functions
DEFF Research Database (Denmark)
Zarri, L.; Tani, A.; Mengoni, M.
2014-01-01
current is still a complex task and cannot be fully tackled with traditional linear control techniques. In this paper a multiple time-scale analysis is proposed to determine an approximated model of the MMC that can be used to solve the control problem of the capacitor voltages. In addition, it is shown...... that the reference signal of the circulating current can be built by combining orthogonal functions of the measured voltages and currents. Numerical simulations are used to test the feasibility of the developed approach.......Modular multilevel converter (MMC) is a promising multilevel topology for high-voltage applications that has been developed in recent years. The control of MMCs has been analyzed in detail in many papers, showing that the converter capacitors can be kept charged and balanced by controlling...
DEFF Research Database (Denmark)
Padmanaban, Sanjeevi Kumar; Blaabjerg, Frede; Siano, Pierluigi
2016-01-01
This paper presents the control strategies by Proportional-Integral (P-I) and Fuzzy Logic (FL) for a DC-DC boost power converter for high output voltage configuration. Standard DC-DC converters are traditionally used for high voltage direct current (HVDC) power transmission systems. But, lack its...... converter with inbuilt voltage-lift technique and overcome the aforementioned deficiencies. Further, the control strategy is adapted based on proportional-integral (P-I) and fuzzy logic, closed-loop controller to regulate the outputs and ensure the performances. Complete hardware prototype of EHV converter...... performances in terms of efficiency, reduced transfer gain and increased cost with sensor units. Moreover, the internal self-parasitic components reduce the output voltage and efficiency of classical high voltage converters (HVC). This investigation focused on extra high-voltage (EHV) DC-DC boost power...
Method and apparatus for controlling LCL converters using asymmetric voltage cancellation techniques
Wu, Hunter; Sealy, Kylee Devro; Sharp, Bryan Thomas; Gilchrist, Aaron
2016-01-26
A method and apparatus for LCL resonant converter control utilizing Asymmetric Voltage Cancellation is described. The methods to determine the optimal trajectory of the control variables are discussed. Practical implementations of sensing load parameters are included. Simple PI, PID and fuzzy logic controllers are included with AVC for achieving good transient response characteristics with output current regulation.
Directory of Open Access Journals (Sweden)
Kureve
2017-08-01
Full Text Available This paper analyzes the plug-in electric tricycle Auto rickshaw battery charging system using a non-isolated DC-DC SEPIC converter which operates as a switched mode power supply SMPS. The control of dc voltage output is by varying the gating pulses duty cycle of the switch in the dc-dc converter using PID controller based PWM technique. The 60 V 30 A DC-DC SEPIC converter is designed to provide non-inverting voltage buck from the rectified AC mains for charging deep cycle battery bank in an electric auto rickshaw. The charger system is implemented using MATLABSimulink.
The New Control and Interlock System for the SPS Main Power Converters
Denis, B; Mugnier, C; Varas, J
1999-01-01
The Control and Interlock System (CIS) of the SPS main power converters was designed in the mid-70s and became increasingly difficult to maintain. A new system based on Programmable Logic Controllers has been developed by an external contractor in close collaboration with CERN. The system is now operational and fully integrated in the SPS/LEP control infrastructure. The CIS is the first major contracted industrial solution used to control accelerator equipment directly involved in the production of particle beams at CERN. This paper gives an overview of the SPS main power converter installation and describes both the contractual and technical solution adopted for the CIS. It first explains how the system was specified and how the contractual relationship was defined to respect CERNs purchasing rules and the operational requirements of the SPS accelerator. The architectural design of the new system is presented with special emphasis on how the conflict between safety and availability has been addressed.
Fault-tolerant design of local controller for the poloidal field converter control system on ITER
International Nuclear Information System (INIS)
Shen, Jun; Fu, Peng; Gao, Ge; He, Shiying; Huang, Liansheng; Zhu, Lili; Chen, Xiaojiao
2016-01-01
Highlights: • The requirements on the Local Control Cubicles (LCC) for ITER Poloidal Field Converter are analyzed. • Decoupled service-based software architecture is proposed to make control loops on LCC running at varying cycle-time. • Fault detection and recovery methods for the LCC are developed to enhance the system. • The performance of the LCC with or without fault-tolerant feature is tested and compared. - Abstract: The control system for the Poloidal Field (PF) on ITER is a synchronously networked control system, which has several kinds of computational controllers. The Local Control Cubicles (LCC) play a critical role in the networked control system for they are the interface to all input and output signals. Thus, some additional work must be done to guarantee the LCCs proper operation under influence of faults. This paper mainly analyzes the system demands of the LCCs and faults which have been encountered recently. In order to handle these faults, decoupled service-based software architecture has been proposed. Based on this architecture, fault detection and system recovery methods, such as redundancy and rejuvenation, have been incorporated to achieve a fault-tolerant private network with the aid of QNX operating system. Unlike the conventional method, this method requires no additional hardware and can be achieved relatively easily. To demonstrate effectiveness the LCCs have been successfully tested during the recent PF Converter Unit performance tests for ITER.
Fault-tolerant design of local controller for the poloidal field converter control system on ITER
Energy Technology Data Exchange (ETDEWEB)
Shen, Jun; Fu, Peng; Gao, Ge; He, Shiying; Huang, Liansheng, E-mail: huangls@ipp.ac.cn; Zhu, Lili; Chen, Xiaojiao
2016-11-15
Highlights: • The requirements on the Local Control Cubicles (LCC) for ITER Poloidal Field Converter are analyzed. • Decoupled service-based software architecture is proposed to make control loops on LCC running at varying cycle-time. • Fault detection and recovery methods for the LCC are developed to enhance the system. • The performance of the LCC with or without fault-tolerant feature is tested and compared. - Abstract: The control system for the Poloidal Field (PF) on ITER is a synchronously networked control system, which has several kinds of computational controllers. The Local Control Cubicles (LCC) play a critical role in the networked control system for they are the interface to all input and output signals. Thus, some additional work must be done to guarantee the LCCs proper operation under influence of faults. This paper mainly analyzes the system demands of the LCCs and faults which have been encountered recently. In order to handle these faults, decoupled service-based software architecture has been proposed. Based on this architecture, fault detection and system recovery methods, such as redundancy and rejuvenation, have been incorporated to achieve a fault-tolerant private network with the aid of QNX operating system. Unlike the conventional method, this method requires no additional hardware and can be achieved relatively easily. To demonstrate effectiveness the LCCs have been successfully tested during the recent PF Converter Unit performance tests for ITER.
CSIR Research Space (South Africa)
Coetzer, A
2016-01-01
Full Text Available The design and implementation of a bidirectional current-controlled voltage-regulated DC-DC converter is presented. The converter is required to connect a battery of electrochemical cells (the battery) to an asynchronous motor-drive unit via a...
On Some Extensions of Szasz Operators Including Boas-Buck-Type Polynomials
Directory of Open Access Journals (Sweden)
Sezgin Sucu
2012-01-01
Full Text Available This paper is concerned with a new sequence of linear positive operators which generalize Szasz operators including Boas-Buck-type polynomials. We establish a convergence theorem for these operators and give the quantitative estimation of the approximation process by using a classical approach and the second modulus of continuity. Some explicit examples of our operators involving Laguerre polynomials, Charlier polynomials, and Gould-Hopper polynomials are given. Moreover, a Voronovskaya-type result is obtained for the operators containing Gould-Hopper polynomials.
Directory of Open Access Journals (Sweden)
Zheng Wang
2016-01-01
Full Text Available Three-port isolated (TPI bidirectional DC/DC converters have three energy ports and offer advantages of large voltage gain, galvanic isolation ability and high power density. For this reason this kind of converters are suitable to connect different energy sources and loads in electric and hybrid vehicles. The purpose of this paper is to propose chaotic modulation and the related control scheme for TPI bidirectional DC/DC converters, in such a way that the switching harmonic peaks can be suppressed in spectrum and the conducted electromagnetic interference (EMI is reduced. Two chaotic modulation strategies, namely the continuously chaotic modulation and the discretely chaotic modulation are presented. These two chaotic modulation strategies are applied for TPI bidirectional DC/DC converters with shifted-phase angle based control and phase-shifted PWM control. Both simulation and experiments are given to verify the validity of the proposed chaotic modulation-based control schemes.
Directory of Open Access Journals (Sweden)
Jiawei Chu
2013-07-01
Full Text Available In this paper, based on the similarity, in structure and principle, between a grid-connected converter for a direct-driven permanent magnet synchronous generator (D-PMSG and an active power filter (APF, a new D-PMSG-based wind turbine (WT system configuration that includes not only an auxiliary converter in parallel with the grid-side converter, but also a coordinated control strategy, is proposed to enhance the low voltage ride through (LVRT capability and improve power quality. During normal operation, the main grid-side converter maintains the DC-link voltage constant, whereas the auxiliary grid-side converter functions as an APF with harmonic suppression and reactive power compensation to improve the power quality. During grid faults, a hierarchical coordinated control scheme for the generator-side converter, main grid-side converter and auxiliary grid-side converter, depending on the grid voltage sags, is presented to enhance the LVRT capability of the direct-driven PMSG WT. The feasibility and the effectiveness of the proposed system’s topology and hierarchical coordinated control strategy were verified using MATLAB/Simulink simulations.
Simple Power Control for Sensorless Induction Motor Drives Fed by a Matrix Converter
DEFF Research Database (Denmark)
Blaabjerg, Frede; Lee, Kyo Beum
2008-01-01
This paper presents a new and simple method for sensorless control of matrix converter drives using a power flowing to the motor. The proposed control algorithm is based on controlling the instantaneous real and imaginary powers into the induction motor. To improve low-speed sensorless performance...
Modeling and Control of the Distributed Power Converters in a Standalone DC Microgrid
Directory of Open Access Journals (Sweden)
Xiaodong Lu
2016-03-01
Full Text Available A standalone DC microgrid integrated with distributed renewable energy sources, energy storage devices and loads is analyzed. To mitigate the interaction among distributed power modules, this paper describes a modeling and control design procedure for the distributed converters. The system configuration and steady-state analysis of the standalone DC microgrid under study are discussed first. The dynamic models of the distributed converters are then developed from two aspects corresponding to their two operating modes, device-regulating mode and bus-regulating mode. Average current mode control and linear compensators are designed accordingly for each operating mode. The stability of the designed system is analyzed at last. The operation and control design of the system are verified by simulation results.
Geetha, A.; Subramani, C.; Thamizh Thentral, T. M.; Krithika, V.; Usha, S.
2018-04-01
Non isolated Bidirectional DC-DC Converter (NIBDDC) is a good interface between DC source and inverter Fed induction motor drive. This paper deals with comparison between open loop and PI controlled Bidirectional DC to DC Converter Inverter System (BDDCIS). The modelling and control of BDDC is becomes an important issue. Open loop BDDCIS and closed loop PI controlled BDDCIS are designed, modelled and simulated using Matlab- simulink and their results are presented. The investigations indicate superior performance of PI controlled BDDCIS. The proposed BDDCIS has advantages like bidirectional power transfer ability, reduced hardware count and improved dynamic response.
Directory of Open Access Journals (Sweden)
Xianjin Huang
2017-11-01
Full Text Available In the application of vehicle power supply and distributed power generation, there are strict requirements for the pulse width modulation (PWM converter regarding power density and reliability. When compared with the conventional insulated gate bipolar transistor (IGBT module, the Reverse Conducting-Insulated Gate Bipolar Transistor (RC-IGBT with the same package has a lower thermal resistance and higher current tolerance. By applying the gate desaturation control, the reverse recovery loss of the RC-IGBT diode may be reduced. In this paper, a loss threshold desaturation control method is studied to improve the output characteristics of the single-phase PWM converter with a low switching frequency. The gate desaturation control characteristics of the RC-IGBT’s diode are studied. A proper current limit is set to avoid the ineffective infliction of the desaturation pulse, while the bridge arm current crosses zero. The expectation of optimized loss decrease is obtained, and the better performance for the RC-IGBTs of the single-phase PWM converter is achieved through the optimized desaturation pulse distribution. Finally, the improved predictive current control algorithm that is applied to the PWM converter with RC-IGBTs is simulated, and is operated and tested on the scaled reduced power platform. The results prove that the gate desaturation control with the improved predictive current algorithm may effectively improve the RC-IGBT’s characteristics, and realize the stable output of the PWM converter.
Directory of Open Access Journals (Sweden)
José Rafael García-Sánchez
2017-01-01
Full Text Available The trajectory tracking task in a wheeled mobile robot (WMR is solved by proposing a three-level hierarchical controller that considers the mathematical model of the mechanical structure (differential drive WMR, actuators (DC motors, and power stage (DC/DC Buck power converters. The highest hierarchical level is a kinematic control for the mechanical structure; the medium level includes two controllers based on differential flatness for the actuators; and the lowest hierarchical level consists of two average controllers also based on differential flatness for the power stage. In order to experimentally validate the feasibility of the proposed control scheme, the hierarchical controller is implemented via a Σ–Δ-modulator in a differential drive WMR prototype that we have built. Such an implementation is achieved by using MATLAB-Simulink and the real-time interface ControlDesk together with a DS1104 board. The experimental results show the effectiveness and robustness of the proposed control scheme.
A Voltage Feedback Based Harmonic Compensation Strategy for Current-Controlled Converters
DEFF Research Database (Denmark)
Zhao, Xin; Meng, Lexuan; Xie, Chuan
2018-01-01
Harmonics have been considered as one of the major issues in future power grids. With the increasing demand in advanced control functions, power electronic converter interfaced distributed generators (DGs) are expected to perform harmonic compensation when necessary. It has been demonstrated in a...
Bathymetry 1M Grid of St. Croix (Buck Island), US Virgin Islands 2005, UTM 20 NAD83
National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains an ESRI Grid with 1 meter cell size representing the bathymetry of the north shore of St. Croix (Buck Island), US Virgin Islands. NOAA's...
NOAA TIFF Graphic- 0.5m Backscatter Mosaic of St. Croix (Buck Island), US Virgin Islands, 2004
National Oceanic and Atmospheric Administration, Department of Commerce — This geotiff represents a 0.5 meter resolution backscatter mosaic of the north shore of Buck Island, St. Croix, US Virgin Islands.NOAA's NOS/NCCOS/CCMA Biogeography...
Bathymetry 1M GRID of St. Croix (Buck Island), US Virgin Islands, 2004, UTM 20 WGS84
National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains an ESRI Grid with 1 meter cell size representing the bathymetry of the north shore of Buck Island St. Croix, US Virgin Islands. NOAA's...
NOAA TIFF Graphic- 0.5m Backscatter Mosaic of St. Croix (Buck Island), US Virgin Islands, 2004
National Oceanic and Atmospheric Administration, Department of Commerce — This image represents a 1 meter resolution backscatter mosaic of the north shore of Buck Island, St. Croix, US Virgin Islands.NOAA's NOS/NCCOS/CCMA Biogeography Team...
Study of matrix converter as a current-controlled power supply in QUEST tokamak
International Nuclear Information System (INIS)
Liu, Xiaolong; Jiang, Yi; Nakamura, Kazuo
2011-01-01
Because QUEST tokamak has a divertor configuration with a higher κ and a negative n-index, a precise power supply with a rapid response is needed to control the vertical position of the plasma. A matrix converter is a direct power conversion device that uses an array of controlled bidirectional switches as the main power elements for creating a variable-output current system. This paper presents a novel three-phase to two-phase topological matrix converter as a proposed power supply that stabilizes the plasma vertical position and achieves unity input power factor. An indirect control strategy in which the matrix converter is split into a virtual rectifier stage and a virtual inverter stage is adopted. In the virtual rectifier stage, the instantaneous active power and reactive power are decoupled on the basis of system equations derived from the DQ transformation; hence, unity power factor is achieved. Space vector pulse width modulation is adopted to determine the switching time of each switch in the virtual rectifier; the output voltage of the virtual rectifier is adjusted by the virtual inverter stage to obtain the desired load current. Theoretical analyses and simulation results are provided to verify its feasibility. (author)
DEFF Research Database (Denmark)
Zhu, Jiebei; Guerrero, Josep M.; Hung, William
2014-01-01
A generic Inertia Emulation Controller (INEC) scheme for Multi-Terminal Voltage-Source-Converter based HVDC (VSC-MTDC) systems is proposed and presented in this paper. The proposed INEC can be incorporated in any Grid-side Voltage-Source-Converter (GVSC) station, allowing the MTDC terminal...
Directory of Open Access Journals (Sweden)
Sumedha Mahajan
2017-04-01
Full Text Available This paper proposes a Capacitor Excited Induction Generator (CEIG-Matrix Converter (MC system for feeding stand-alone AC loads. The variable output voltage magnitude and frequency from CEIG is converted into a constant voltage magnitude and frequency at the load terminals by controlling MC using Space Vector Modulation (SVM technique. This single-stage MC is turned up as a good alternative for the proposed system against commonly used AC/DC/AC two stage power converters. The configuration and implementation of the closed-loop control scheme employing dSPACE 1103 real time controller have been fully described in the paper. The proposed closed-loop controller regulates the AC load voltage irrespective of changes in the prime mover speed and load. A method for predetermining the steady-state performance of the proposed system has been developed and described with relevant analytical expressions. The effectiveness of the proposed system is exemplified through simulation results for various operating conditions. The proposed control technique is further validated using an experimental setup developed in the laboratory.
Soft switching resonant converter with duty-cycle control in DC micro-grid system
Lin, Bor-Ren
2018-01-01
Resonant converter has been widely used for the benefits of low switching losses and high circuit efficiency. However, the wide frequency variation is the main drawback of resonant converter. This paper studies a new modular resonant converter with duty-cycle control to overcome this problem and realise the advantages of low switching losses, no reverse recovery current loss, balance input split voltages and constant frequency operation for medium voltage direct currentgrid or system network. Series full-bridge (FB) converters are used in the studied circuit in order to reduce the voltage stresses and power rating on power semiconductors. Flying capacitor is used between two FB converters to balance input split voltages. Two circuit modules are paralleled on the secondary side to lessen the current rating of rectifier diodes and the size of magnetic components. The resonant tank is operated at inductive load circuit to help power switches to be turned on at zero voltage with wide load range. The pulse-width modulation scheme is used to regulate output voltage. Experimental verifications are provided to show the performance of the proposed circuit.
High-frequency matrix converter with square wave input
Carr, Joseph Alexander; Balda, Juan Carlos
2015-03-31
A device for producing an alternating current output voltage from a high-frequency, square-wave input voltage comprising, high-frequency, square-wave input a matrix converter and a control system. The matrix converter comprises a plurality of electrical switches. The high-frequency input and the matrix converter are electrically connected to each other. The control system is connected to each switch of the matrix converter. The control system is electrically connected to the input of the matrix converter. The control system is configured to operate each electrical switch of the matrix converter converting a high-frequency, square-wave input voltage across the first input port of the matrix converter and the second input port of the matrix converter to an alternating current output voltage at the output of the matrix converter.
DEFF Research Database (Denmark)
Liu, Dong; Deng, Fujin; Chen, Zhe
2017-01-01
The capacitor current would be imbalanced under the conventional control strategy in the half-bridge three-level (HBTL) DC/DC converter due to the effect of the output inductance of the power supply and the input line inductance, which would affect the converter's reliability. This paper proposes...... a pulse-wide modulation (PWM) strategy composed of two operation modes for the HBTL DC/DC converter, which can realize the zero-voltage switching (ZVS) for the efficiency improvement. In addition, a capacitor current balancing control is proposed by alternating the two operation modes of the proposed ZVS...... PWM strategy, which can eliminate the current imbalance among the two input capacitors. Therefore, the proposed control strategy can improve the converter's performance and reliability in: 1) reducing the switching losses and noises of the power switches; 2) balancing the thermal stresses...
Directory of Open Access Journals (Sweden)
Pui-Sun Lei
2015-01-01
Full Text Available This Letter presents a low start-up voltage dc–dc converter for low-power thermoelectric systems which uses a native n-type MOS transistor as the start-up switch. The start-up voltage of the proposed converter is 300 mV and the converter does not need batteries to start up. The negative voltage control is proposed to reduce the leakage current caused by native n-type transistor and increase the efficiency. The proposed converter was designed using standard 0.18 µm CMOS process with chip size of 0.388 mm^2. The peak efficiency is 63% at load current of 1.5 mA. The proposed converter provides output voltage >1 V at maximum load current of 3.2 mA.
Research and implementation of PC data synchronous backup based on cloud computing
Directory of Open Access Journals (Sweden)
JIANG Lan
2013-02-01
Full Text Available A kind of anti－saturated digital PI regulator is designed and implemented based on DSP.This PI regulator was applied to the system design of voltage and current double－loop control in a BUCK converter and related experimental research was made in a 5.5 KW prototype machine.Experimental results show that the converter has good static and dynamic performances and the validity of the design of the PI regulator is verified.
Efficient Visible Light Communication Transmitters Based on Switching-Mode dc-dc Converters
2018-01-01
Visible light communication (VLC) based on solid-state lighting (SSL) is a promising option either to supplement or to substitute existing radio frequency (RF) wireless communication in indoor environments. VLC systems take advantage of the fast modulation of the visible light that light emitting diodes (LEDs) enable. The switching-mode dc-to-dc converter (SMCdc-dc) must be the cornerstone of the LED driver of VLC transmitters in order to incorporate the communication functionality into LED lighting, keeping high power efficiency. However, the new requirements related to the communication, especially the high bandwidth that the LED driver must achieve, converts the design of the SMCdc-dc into a very challenging task. In this work, three different methods for achieving such a high bandwidth with an SMCdc-dc are presented: increasing the order of the SMCdc-dc output filter, increasing the number of voltage inputs, and increasing the number of phases. These three strategies are combinable and the optimum design depends on the particular VLC application, which determines the requirements of the VLC transmitter. As an example, an experimental VLC transmitter based on a two-phase buck converter with a fourth-order output filter will demonstrate that a bandwidth of several hundred kilohertz (kHz) can be achieved with output power levels close to 10 W and power efficiencies between 85% and 90%. In conclusion, the design strategy presented allows us to incorporate VLC into SSL, achieving high bit rates without damaging the power efficiency of LED lighting. PMID:29642455
LPV model for PV cell and fractional control of DC/DC converter for photovoltaic systems
Martínez González, Rubén; Bolea Monte, Yolanda; Grau Saldes, Antoni; Martínez García, Herminio
2011-01-01
This paper deals with the fractional modelling of a DC-DC converter, suitable in solar-powered electrical generation systems, and the design of a fractional controller for the aforementioned switching converter. A new model for PV cells is proposed in order to obtain a linear equation for V-I characteristic via scheduling dependence of temperature and irradiance. Due to the fractional nature of the ultracapacitors this kind of controller gives a suitable and good performance. Peer Reviewed
LPV model for PV cells and fractional control of DC/DC converter for photovoltaic systems
Martínez González, Rubén; Bolea Monte, Yolanda; Grau Saldes, Antoni; Martínez García, Herminio
2011-01-01
This paper deals with the fractional modelling of a DC-DC converter, suitable in solar-powered electrical generation systems, and the design of a fractional controller for the aforementioned switching converter. A new model for PV cells is proposed in order to obtain a linear equation for VI characteristic via scheduling dependence of temperature and irradiance. Due to the fractional nature of the ultracapacitors this kind of controller gives a suitable and good performance. Peer Rev...
International Nuclear Information System (INIS)
King, Q.; Page, S.T.; Thiesen, H.; Veenstra, M.
2012-01-01
Power converter control for the LHC is based on an embedded control computer called a Function Generator/Controller (FGC). Every converter includes an FGC with responsibility for the generation of the reference current as a function of time and the regulation of the circuit current, as well as control of the converter state. With many new converter controls software classes in development it was decided to generalize several key components of the FGC software in the form of C libraries: function generation in libfg, regulation, limits and simulation in libreg and DCCT, ADC and DAC calibration in libcal. These libraries were first used in the software class dedicated to controlling the new 60 MW main power converter (POPS) at the CERN Proton Synchrotron (CPS) where regulation of both magnetic field and circuit current is supported. This paper reports on the functionality provided by each library and in particular libfg and libreg. The libraries are already being used by software classes in development for the next generation FGC for Linac4 converters, as well as the CERN SPS converter controls (MUGEF) and MedAustron converter regulation board. (authors)
Directory of Open Access Journals (Sweden)
Ramji Tiwari
2018-02-01
Full Text Available This paper proposes an artificial neural network (ANN based maximum power point tracking (MPPT control strategy for wind energy conversion system (WECS implemented with a DC/DC converter. The proposed topology utilizes a radial basis function network (RBFN based neural network control strategy to extract the maximum available power from the wind velocity. The results are compared with a classical Perturb and Observe (P&O method and Back propagation network (BPN method. In order to achieve a high voltage rating, the system is implemented with a quadratic boost converter and the performance of the converter is validated with a boost and single ended primary inductance converter (SEPIC. The performance of the MPPT technique along with a DC/DC converter is demonstrated using MATLAB/Simulink.
Optimising Reactive Control in non-ideal Efficiency Wave Energy Converters
DEFF Research Database (Denmark)
Strager, Thomas; Lopez, Pablo Fernandez; Giorgio, Giuseppe
2014-01-01
When analytically optimising the control strategy in wave energy converters which use a point absorber, the efficiency aspect is generally neglected. The results presented in this paper provide an analytical expression for the mean harvested electrical power in non-ideal efficiency situations....... These have been derived under the assumptions of monochromatic incoming waves and linear system behaviour. This allows to establish the power factor of a system with non-ideal efficiency. The locus of the optimal reactive control parameters is then studied and an alternative method of representation...... is developed to model the optimal control parameters. Ultimately we present a simple method of choosing optimal control parameters for any combination of efficiency and wave frequency....
DEFF Research Database (Denmark)
Tang, Yi; Yoon, Changwoo; Zhu, Rongwu
2015-01-01
This paper investigates the stability regions of current control for LCL-filtered grid-connected converters, where no active or passive damping is required to stabilize the closed-loop control system. It is already identified in the literature that if the LCL resonance frequency is placed within 1....../6 to 1/2 of the system sampling frequency, the grid current control can be directly used without damping. If the resonance frequency is smaller than 1/6 of the sampling frequency, the converter current control should then be adopted. This paper further extends the analysis to the cases where...... the resonance frequency could be larger than 1/2 of the sampling frequency, and derives the complete stability regions for both grid and converter current control. Interestingly, it is found that for any given LCL-filter design, there will always be one stable current control design without any damping, which...
Control Strategy of Active Power Filter Based on Modular Multilevel Converter
Xie, Xifeng
2018-03-01
To improve the capacity, pressure resistance and the equivalent switching frequency of active power filter (APF), a control strategy of APF based on Modular Multilevel Converter (MMC) is presented. In this Control Strategy, the indirect current control method is used to achieve active current and reactive current decoupling control; Voltage Balance Control Strategy is to stabilize sub-module capacitor voltage, the predictive current control method is used to Track and control of harmonic currents. As a result, the harmonic current is restrained, and power quality is improved. Finally, the simulation model of active power filter controller based on MMC is established in Matlab/Simulink, the simulation proves that the proposed strategy is feasible and correct.
International Nuclear Information System (INIS)
Hirano, M.; Kustom, R.L.
1984-03-01
An inductor-converter bridge (ICB) is a solid state DC-AC-DC power converter system for bidirectional, controllable, energy transfer between two coils. The ICB is suitable for supplying large pulsed power to such magnets as the superconducting equilibrium field coil of the proposed tokamak power reactors from another superconducting energy storage coil
Multi-Objective Optimization Control for the Aerospace Dual-Active Bridge Power Converter
Directory of Open Access Journals (Sweden)
Tao Lei
2018-05-01
Full Text Available With the development of More Electrical Aircraft (MEA, the electrification of secondary power systems in aircraft is becoming more and more common. As the key power conversion device, the dual active bridge (DAB converter is the power interface for the energy storage system with the high voltage direct current (HVDC bus in aircraft electrical power systems. In this paper, a DAB DC-DC converter is designed to meet aviation requirements. The extended dual phase shifted control strategy is adopted, and a multi-objective genetic algorithm is applied to optimize its operating performance. Considering the three indicators of inductance current root mean square root (RMS value, negative reverse power and direct current (DC bias component of the current for the high frequency transformer as the optimization objectives, the DAB converter’s optimization model is derived to achieve soft switching as the main constraint condition. Optimized methods of controlling quantity for the DAB based on the evolution and genetic algorithm is used to solve the model, and a number of optimal control parameters are obtained under different load conditions. The results of digital, hard-in-loop simulation and hardware prototype experiments show that the three performance indexes are all suppressed greatly, and the optimization method proposed in this paper is reasonable. The work of this paper provides a theoretical basis and researching method for the multi-objective optimization of the power converter in the aircraft electrical power system.
A novel grounded to floating admittance converter with electronic control
Prasad, Dinesh; Ahmad, Javed; Srivastava, Mayank
2018-01-01
This article suggests a new grounded to floating admittance convertor employing only two voltage differencing transconductance amplifiers (VDTAs). The proposed circuit can convert any arbitrary grounded admittance into floating admittance with electronically controllable scaling factor. The presented converter enjoys the following beneficial: (1) no requirement of any additional passive element (2) scaling factor can be tuned electronically through bias currents of VDTAs (3) no matching constraint required (4) low values of active/passive sensitivity indexes and (5) excellent non ideal behavior that indicates no deviation in circuit behavior even under non ideal environment. Application of the proposed configuration in realization of floating resistor and floating capacitor has been presented and the workability of these floating elements has been confirmed by active filter design examples. SPICE simulations have been performed to demonstrate the performance of the proposed circuits.
DEFF Research Database (Denmark)
Ekhtiari, Marzieh
electromagnetic interference, compact, light, high power density and low cost allows for promising market in the near future. The piezoelectric transformer technology has the potential to be used in various applications e.g. motor driver for magnetic resonance imaging scans, the electronic ballast for fluorescent...... of inductorless switch-mode power supplies employing piezoelectric transformers. The main focus of this research is on the functionality of the piezoelectric transformer-based power converters and applying control techniques in order to exploit advantages of the piezoelectric transformers for the power converters...... detector applicable for switch-mode power supplies, optimum phase detector, bi-directional wide bandwidth current sensor and a comprehensive analysis of piezoelectric transformer-based switch-mode power supplies for zero-voltage switching, where all finalized with improving the unidirectional topology...
DEFF Research Database (Denmark)
Jia, Jundi; Yang, Guangya; Nielsen, Arne Hejde
2017-01-01
behave significantly different from the traditional alternators under grid faults. In order to evaluate the potential impact of future converter-based power systems on protective relays, it is necessary to consider diverse current control strategies of voltage source converters (VSC) under unbalanced...
International Nuclear Information System (INIS)
Etxeberria, A.; Vechiu, I.; Camblong, H.; Kreckelbergh, S.; Bacha, S.
2014-01-01
Highlights: • The control of a hybrid storage system using a Three Level NPC converter is analysed. • A sinusoidal PWM with an offset injection is used to control the storage system. • The operation of the selected converter is analysed in its entire operation range. • The operational limits of the Three Level NPC converter are defined. - Abstract: This work analyses the use of a Three-Level Neutral Point Clamped (3LNPC) converter to control the power flow of a Hybrid Energy Storage System (HESS) and at the same time interconnect it with the common AC bus of a microgrid. Nowadays there is not any storage technology capable of offering a high energy storage capacity, a high power capacity and a fast response at the same time. Therefore, the necessity of hybridising more than one storage technology is a widely accepted idea in order to satisfy the mentioned requirements. This work shows how the operational limits of the 3LNPC converter can be calculated and integrated in a control structure to facilitate an optimal use of the HESS according to the rules fixed by the user
DEFF Research Database (Denmark)
Blaabjerg, Frede; Vilathgamuwa, D. M.; Loh, Poh Chiang
2009-01-01
Distributed generation (DG) systems are usually connected to the grid using power electronic converters. Power delivered from such DG sources depends on factors like energy availability and load demand. The converters used in power conversion do not operate with their full capacity all the time......-stage buck-boost inverter, recently proposed Z-source inverter (ZSI) is a good candidate for future DG systems. This paper presents a controller design for a ZSI-based DG system to improve power quality of distribution systems. The proposed control method is tested with simulation results obtained using...
Directory of Open Access Journals (Sweden)
Kil To Chong
2013-10-01
Full Text Available The main objective of the present work is to apply a sliding mode controller (SMC to medium voltage and high power output energy recovery Li-ion power accumulator battery pack testing systems (ERLPABTSs, which are composed of a three-level neutral-point-clamped (NPC three-phase voltage source inverter (VSI and a two-level buck-boost converter without an isolating transformer. An inner current decoupled control scheme for the aforementioned system is proposed and two sliding mode planes for active and reactive current control are designed based on the control scheme. An optimized switching table for current convergence is used according to the error sign of the equivalent input voltage and feedback voltage. The proposed ERLPABTS could be used to integrate discharging energy into the power grid when performing high accuracy current testing. The active and reactive power references for the grid-connected inverter are determined based on the discharging energy from the DC-DC converter. Simulations and experiments on a laboratory hardware platform using a 175 kW insulated gate bipolar transistor (IGBT-based ERLPABTS have been implemented and verified, and the performance is found satisfactory and superior to conventional ERLPABPTS.
Discussion on the control method of the inductor-converter bridge by simulation and experiment
International Nuclear Information System (INIS)
Hirano, M.; Kustom, R.L.
1983-07-01
With the development of the superconducting magnet as an energy storage unit, pulsed power loads between superconducting magnets of increasing magnitude up to several hundred megawatts or more appear within the realm of possibility. An energy storage unit that is independent of the power grid can be used in applications where the pulsed power required from the power grid may cause a hazardous effect on the power system. An energy transfer system between the storage and the load units eliminates the disturbance on the power grid. An inductor-converter bridge is proposed for such a purpose. The inductor-converter bridge (ICB) is a solid state DC-AC-DC converter system for reversible energy transfer between two high-inductance inductors. The converter thyristors are naturally commutated by a set of wye-connected capacitors on the AC lines of the circuit. The circuit is designed so that, in every converter cycle, a very small fraction of the magnet energy is stored in these capacitors. The characteristics of the inductor-converter bridge are briefly summarized as follows: low energy loss, reversibility of the energy transfer direction, controllability of the energy transfer rate, and no conversion to another energy form
New drive converter and digital control for the pulsed power supply system of ASDEX Upgrade
Energy Technology Data Exchange (ETDEWEB)
Käsemann, Claus-Peter, E-mail: c.p.kaesemann@ipp.mpg.de [Max Planck Institute for Plasma Physics, Boltzmannstraße 2, 85748 Garching (Germany); Jacob, Christian; Nguyen, Hong Ha; Stobbe, Ferdinand; Mayer, Alois [Max Planck Institute for Plasma Physics, Boltzmannstraße 2, 85748 Garching (Germany); Sachs, Edgar; Klein, Reiner [Siemens AG, Industrial Automation Systems, Gleiwitzer Straße 555, 90475 Nürnberg (Germany)
2015-10-15
Highlights: • IGBT converter system with integrated control. • Proven technology reduces time and budget. • Flexibility to be integrated into a 35 years old installation. • Stable control algorithms for static and dynamic speed control. • Possibilities for active and reactive power management. - Abstract: Safety and reliability are major issues for the ASDEX Upgrade (AUG) pulsed power supply systems. To avoid long downtimes during an experimental campaign, fault-prone components have to be identified and treated early. This becomes even more important due to the AUG participation in the EUROfusion Medium Sized Tokamak (MST) program. Operating equipment which is up to 40 years old adds additional complications. This contribution describes one such example where a 35 year old flywheel generator at AUG was identified as fault-prone and pre-emptively upgraded with a new drive converter with integrated control. Most challenging was to adapt a modern converter, originally designed for wind turbines, toward a drive system for a flywheel-motor-generator system. To identify the layout of the controller and the control parameters, accurate modeling and comprehensive simulations were performed. This effort paid off during commissioning and measuring results verified the calculated design values. Finally, the system shows good performance during AUG plasma experiments.
One-phase dual converter for two quadrant power control of superconducting magnets
International Nuclear Information System (INIS)
Ehsani, M.; Kustom, R.I.; Boom, R.W.
1985-01-01
This paper presents the results of theoretical and experimental development of a new dc-ac-dc converter for superconducting magnet power supplies. The basic operating principles of the circuit are described followed by a theoretical treatment of the dynamics and control of the system. The successful results of the first experimental operation and control of such a circuit are presented and discussed
Directory of Open Access Journals (Sweden)
Nagarajan Booma
2016-04-01
Full Text Available This paper discusses about the fixed frequency pulse mask control based high frequency AC conversion circuit for industrial induction heating applications. Conventionally, for induction heating load, the output power control is achieved using the pulse with modulation based converters. The conventional converters do not guarantee the zero voltage switching condition required for the minimization of the switching losses. In this paper, pulse mask control scheme for the power control of induction heating load is proposed. This power control strategy allows the inverter to operate closer to the resonant frequency, to obtain zero voltage switching condition. The proposed high frequency AC power conversion circuit has lesser total harmonic distortion in the supply side. Modeling of the IH load, design of conversion circuit and principle of the control scheme and its implementation using low cost PIC controller are briefly discussed. Simulation results obtained using the Matlab environment are presented to illustrate the effectiveness of the pulse mask scheme. The obtained results indicate the reduction in losses, improvement in the output power and lesser harmonic distortion in the supply side by the proposed converter. The hardware results are in good agreement with the simulation results.
Distributed control system for parallel-connected DC boost converters
Goldsmith, Steven
2017-08-15
The disclosed invention is a distributed control system for operating a DC bus fed by disparate DC power sources that service a known or unknown load. The voltage sources vary in v-i characteristics and have time-varying, maximum supply capacities. Each source is connected to the bus via a boost converter, which may have different dynamic characteristics and power transfer capacities, but are controlled through PWM. The invention tracks the time-varying power sources and apportions their power contribution while maintaining the DC bus voltage within the specifications. A central digital controller solves the steady-state system for the optimal duty cycle settings that achieve a desired power supply apportionment scheme for a known or predictable DC load. A distributed networked control system is derived from the central system that utilizes communications among controllers to compute a shared estimate of the unknown time-varying load through shared bus current measurements and bus voltage measurements.
DEFF Research Database (Denmark)
Taeed, Fazel; Salam, Z.; Ayob, S.
2012-01-01
converter (ADC). Instead, a simple analog-to-digital conversion scheme is implemented using the FPGA itself. Due to the simplicity of the SIFLC algorithm and the absence of an external ADC, the overall implementation requires only 408 logic elements and five input-output pins of the FPGA.......) and applied on a 50-W boost converter. The SIFLC is compared to the proportional-integral controller; the simulation and practical results indicate that SIFLC exhibits excellent performance for step load and input reference changes. Another feature of this work is the absence of an external analog-to-digital...
Umar, S; Ahmad, M; Ahmad, I; Zubair, M; Umar, Z; Qureshi, A S; Manzoor, A; Murtaza, A; Shaukat, A
2018-04-01
This study was planned to determine the relationship between semen quality parameters and the levels of biochemical constituents of seminal plasma of Teddy (Capra hircus) buck semen. For this purpose, semen ejaculates were collected from five mature healthy Teddy bucks. All the experimental bucks were kept under natural environmental conditions. Semen was collected twice in a week for the duration of 6 weeks by Artificial Vagina (AV) in the breeding season (February-April). Two successive ejaculates of single buck were pooled at time of collection, and a total of 60 semen samples were processed for semen analysis. Sperm per cent motility, sperm concentration, dead sperm percentage, morphological abnormal spermatozoa, plasma membrane integrity were correlated with biochemical constituents of seminal plasma. The mean per cent motility (89.18% ± 0.37%), sperm concentration (1.86 ± 0.04 × 10 9 /ml), dead sperm percentage (8.08% ± 0.29%), morphological abnormal spermatozoa (6.05% ± 0.29%) and plasma membrane integrity (88.22% ± 0.34%) were recorded. The seminal plasma contained Na + (144.12 ± 1.59 mEq/L), K + (27.38 ± 0.49 mEq/L), Cl - (65.73 ± 0.45 mEq/L), Ca ++ (9.34 ± 0.22 mg/dl), P (19.32 ± 0.97 mg/dl), aspartate aminotransferase (AST; 26.48 ± 1.30 IU/L), alanine aminotransferase (ALT; 168.47 ± 5.18 IU/L), lactate dehydrogenase (LDH; 215.98 ± 6.06 IU/L), albumin (1.90 ± 0.10 g/dl), globulins (2.08 ± 0.11 g/dl) and total protein (3.98 ± 0.20 g/dl). The collected data were analysed by applying Pearson's correlation coefficients. Dead sperm percentage had negative correlation with sodium (r = -.278, p correlated with plasma membrane integrity (r = -.292, p correlated with biochemical constituents, but opposite trends were found in case of dead sperm percentage. The seminal biochemical constituents dynamically interact with each other. © 2017 Blackwell Verlag GmbH.
Directory of Open Access Journals (Sweden)
Mahdi Shahparasti
2018-02-01
Full Text Available In renewable energy based systems Grid-Connected Voltage Source Converters (GC-VSC are used in many applications as grid-feeding converters, which transfer the power coming from the renewable energy sources to the grid. In some cases, the operation of GC-VSC may become unstable or uncontrollable due to, among others: a grid fault or an inappropriate current-power reference, that give rise to fast electrical transients or a saturation of the controller. In this paper, an improved control scheme is proposed to enhance the controllability of GC-VSC in all these situations. This solution consists of two parts, on the one hand a new Proportional-Resonant (PR controller with anti-windup capability to be used as current controller, and secondly a new current/power reference modifier, which defines the suitable reactive current/power reference to keep the system stable. It is worth to mention that the proposed scheme does not need information about the grid parameters as it only uses the converter current, and the voltage at the capacitors of Inductor-Capacitor (LC output filter.
Control method of Three-phase Four-leg converter based on repetitive control
Hui, Wang
2018-03-01
The research chose the magnetic levitation force of wind power generation system as the object. In order to improve the power quality problem caused by unbalanced load in power supply system, we combined the characteristics and repetitive control principle of magnetic levitation wind power generation system, and then an independent control strategy for three-phase four-leg converter was proposed. In this paper, based on the symmetric component method, the second order generalized integrator was used to generate the positive and negative sequence of signals, and the decoupling control was carried out under the synchronous rotating reference frame, in which the positive and negative sequence voltage is PI double closed loop, and a PI regulator with repetitive control was introduced to eliminate the static error regarding the fundamental frequency fluctuation characteristic of zero sequence component. The simulation results based on Matlab/Simulink show that the proposed control project can effectively suppress the disturbance caused by unbalanced loads and maintain the load voltage balance. The project is easy to be achieved and remarkably improves the quality of the independent power supply system.
multilevel buck converter for automotive electrical load
African Journals Online (AJOL)
user
The electrical low voltage load requirement in the passenger vehicle is ... oxides emissions, and 82% of carbon monoxides (CO). [4]. ... government placed an order restricting the movement ... transient and steady-state characteristics of the.
Burns, W. W., III; Wilson, T. G.
1976-01-01
State-plane analysis techniques are employed to study the voltage step up energy storage dc-to-dc converter. Within this framework, an example converter operating under the influence of a constant on time and a constant frequency controller is examined. Qualitative insight gained through this approach is used to develop a conceptual free running control law for the voltage step up converter which can achieve steady state operation in one on/off cycle of control. Digital computer simulation data is presented to illustrate and verify the theoretical discussions presented.
Power Control at Grid Connected Converters and Analytical Solution of Steady States
Czech Academy of Sciences Publication Activity Database
Valouch, Viktor; Škramlík, Jiří; Muller, Z.; Švec, J.; Tlustý, J.
2015-01-01
Roč. 2015, September (2015), s. 1-12 ISSN 1024-123X Institutional support: RVO:61388998 Keywords : power control * converter * grid Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 0.644, year: 2015 http://downloads.hindawi.com/journals/mpe/2015/601916.pdf
GeoTIFF of 3x3 m Bathymetry for Buck Island, St. Croix, 2011, UTM 20N NAD83
National Oceanic and Atmospheric Administration, Department of Commerce — This image represents a LiDAR (Light Detection & Ranging) 3x3 meter resolution bathymetric surface for an area including and surrounding Buck Island Reef...
Electromagnetic Compatibility of Matrix Converter System
Directory of Open Access Journals (Sweden)
S. Fligl
2006-12-01
Full Text Available The presented paper deals with matrix converters pulse width modulation strategies design with emphasis on the electromagnetic compatibility. Matrix converters provide an all-silicon solution to the problem of converting AC power from one frequency to another, offering almost all the features required of an ideal static frequency changer. They possess many advantages compared to the conventional voltage or current source inverters. A matrix converter does not require energy storage components as a bulky capacitor or an inductance in the DC-link, and enables the bi-directional power flow between the power supply and load. The most of the contemporary modulation strategies are able to provide practically sinusoidal waveforms of the input and output currents with negligible low order harmonics, and to control the input displacement factor. The perspective of matrix converters regarding EMC in comparison with other types of converters is brightly evident because it is no need to use any equipment for power factor correction and current and voltage harmonics reduction. Such converter with proper control is properly compatible both with the supply mains and with the supplied load. A special digital control system was developed for the realized experimental test bed which makes it possible to achieve greater throughput of the digital control system and its variability.
Distributed maximum power point tracking in photovoltaic applications: active bypass DC/DC converter
Directory of Open Access Journals (Sweden)
Carlos Andrés Ramos-Paja
2012-01-01
Full Text Available Se propone una estructura de desvío activo para maximizar la producción de potencia en sistemas fotovoltaicos bajo condiciones irregulares de operación, comparando su eficiencia con soluciones individuales y distribuidas basadas en convertidores DC/DC convencionales. Los análisis y simulaciones realistas demuestran las ventajas del nuevo convertidor de desvío activo sobre soluciones basadas en convertidores Boost, Buck y Buck-Boost.