Results of cycling with battery charging management; Resultats de cyclage avec gestion de charge au niveau batterie

Energy Technology Data Exchange (ETDEWEB)

Verniolle, J; Fernandez, C [European Space Research and Technology Centre, Noordwijk (Netherlands)

1997-12-31

In order to investigate the charging mode of an in-series assembly of lithium-carbon battery cells, a test has been performed on 5 commercial cells (18650) of 0.95 Ah nominal capacity. Results show that it is possible to cycle the cells at 80% of their output capacities during more than 2000 cycles. The management of the battery consists in maintaining a constant battery voltage as soon as a cell reaches its limit voltage during constant current charging. The initial dispersion of cells has been maintained practically constant during the cycling and the charge state of all cells has decreased progressively. (J.S.)

Supervised chaos genetic algorithm based state of charge determination for LiFePO4 batteries in electric vehicles

Science.gov (United States)

Shen, Yanqing

2018-04-01

LiFePO4 battery is developed rapidly in electric vehicle, whose safety and functional capabilities are influenced greatly by the evaluation of available cell capacity. Added with adaptive switch mechanism, this paper advances a supervised chaos genetic algorithm based state of charge determination method, where a combined state space model is employed to simulate battery dynamics. The method is validated by the experiment data collected from battery test system. Results indicate that the supervised chaos genetic algorithm based state of charge determination method shows great performance with less computation complexity and is little influenced by the unknown initial cell state.

Inline state of health estimation of lithium-ion batteries using state of charge calculation

Science.gov (United States)

Sepasi, Saeed; Ghorbani, Reza; Liaw, Bor Yann

2015-12-01

The determination of state-of-health (SOH) and state-of-charge (SOC) is challenging and remains as an active research area in academia and industry due to its importance for Li-ion battery applications. The estimation process poses more challenges after substantial battery aging. This paper presents an inline SOH and SOC estimation method for Li-ion battery packs, specifically for those based on LiFePO4 chemistry. This new hybridized SOC and SOH estimator can be used for battery packs. Inline estimated model parameters were used in a compounded SOC + SOH estimator consisting of the SOC calculation based on coulomb counting method as an expedient approach and an SOH observer using an extended Kalman filter (EKF) technique for calibrating the estimates from the coulomb counting method. The algorithm's low SOC and SOH estimation error, fast response time, and less-demanding computational requirement make it practical for on-board estimations. The simulation and experimental results, along with the test bed structure, are presented to validate the proposed methodology on a single cell and a 3S1P LiFePO4 battery pack.

High-Power Collective Charging of a Solid-State Quantum Battery

Science.gov (United States)

Ferraro, Dario; Campisi, Michele; Andolina, Gian Marcello; Pellegrini, Vittorio; Polini, Marco

2018-03-01

Quantum information theorems state that it is possible to exploit collective quantum resources to greatly enhance the charging power of quantum batteries (QBs) made of many identical elementary units. We here present and solve a model of a QB that can be engineered in solid-state architectures. It consists of N two-level systems coupled to a single photonic mode in a cavity. We contrast this collective model ("Dicke QB"), whereby entanglement is genuinely created by the common photonic mode, to the one in which each two-level system is coupled to its own separate cavity mode ("Rabi QB"). By employing exact diagonalization, we demonstrate the emergence of a quantum advantage in the charging power of Dicke QBs, which scales like √{N } for N ≫1 .

Alternator control for battery charging

Energy Technology Data Exchange (ETDEWEB)

Brunstetter, Craig A.; Jaye, John R.; Tallarek, Glen E.; Adams, Joseph B.

2015-07-14

In accordance with an aspect of the present disclosure, an electrical system for an automotive vehicle has an electrical generating machine and a battery. A set point voltage, which sets an output voltage of the electrical generating machine, is set by an electronic control unit (ECU). The ECU selects one of a plurality of control modes for controlling the alternator based on an operating state of the vehicle as determined from vehicle operating parameters. The ECU selects a range for the set point voltage based on the selected control mode and then sets the set point voltage within the range based on feedback parameters for that control mode. In an aspect, the control modes include a trickle charge mode and battery charge current is the feedback parameter and the ECU controls the set point voltage within the range to maintain a predetermined battery charge current.

Estimating Lithium-Ion Battery State of Charge and Parameters Using a Continuous-Discrete Extended Kalman Filter

Directory of Open Access Journals (Sweden)

Yasser Diab

2017-07-01

Full Text Available A real-time determination of battery parameters is challenging because batteries are non-linear, time-varying systems. The transient behaviour of lithium-ion batteries is modelled by a Thevenin-equivalent circuit with two time constants characterising activation and concentration polarization. An experimental approach is proposed for directly determining battery parameters as a function of physical quantities. The model’s parameters are a function of the state of charge and of the discharge rate. These can be expressed by regression equations in the model to derive a continuous-discrete extended Kalman estimator of the state of charge and of other parameters. This technique is based on numerical integration of the ordinary differential equations to predict the state of the stochastic dynamic system and the corresponding error covariance matrix. Then a standard correction step of the extended Kalman filter (EKF is applied to increase the accuracy of estimated parameters. Simulations resulting from this proposed estimator model were compared with experimental results under a variety of operating scenarios—analysis of the results demonstrate the accuracy of the estimator for correctly identifying battery parameters.

Adaptive estimation of state of charge and capacity with online identified battery model for vanadium redox flow battery

Science.gov (United States)

Wei, Zhongbao; Tseng, King Jet; Wai, Nyunt; Lim, Tuti Mariana; Skyllas-Kazacos, Maria

2016-11-01

Reliable state estimate depends largely on an accurate battery model. However, the parameters of battery model are time varying with operating condition variation and battery aging. The existing co-estimation methods address the model uncertainty by integrating the online model identification with state estimate and have shown improved accuracy. However, the cross interference may arise from the integrated framework to compromise numerical stability and accuracy. Thus this paper proposes the decoupling of model identification and state estimate to eliminate the possibility of cross interference. The model parameters are online adapted with the recursive least squares (RLS) method, based on which a novel joint estimator based on extended Kalman Filter (EKF) is formulated to estimate the state of charge (SOC) and capacity concurrently. The proposed joint estimator effectively compresses the filter order which leads to substantial improvement in the computational efficiency and numerical stability. Lab scale experiment on vanadium redox flow battery shows that the proposed method is highly authentic with good robustness to varying operating conditions and battery aging. The proposed method is further compared with some existing methods and shown to be superior in terms of accuracy, convergence speed, and computational cost.

A low cost, microprocessor-based battery charge controller

Energy Technology Data Exchange (ETDEWEB)

Pulfrey, D L; Hacker, J [Pulfrey Solar Inc., Vancouver, BC (Canada)

1990-01-01

This report describes the design, construction, testing, and evaluation of a microprocessor-based battery charge controller that uses charge integration as the method of battery state-of-charge estimation. The controller is intended for use in medium-size (100-1000W) photovoltaic systems that employ 12V lead-acid batteries for charge storage. The controller regulates the charge flow to the battery and operates in three, automatically-determined modes, namely: charge, equalize, and float. The prototype controller is modular in nature and can handle charge/discharge currents of magnitude up to 80A, depending on the number of circuit boards employed. Evaluation tests and field trials have shown the controller to be very accurate and reliable. Based on the cost of the prototype, it appears that an original equipment manufacturer's selling price of $400 for a 40A (500W) unit may be realistic. 18 figs., 2 tabs.

Uncertainty analysis in a real-time state-of-charge evaluation system for lithium-ion batteries

NARCIS (Netherlands)

Pop, V.; Regtien, P.P.L.; Bergveld, H.J.; Notten, P.H.L.; Op het Veld, B.

2006-01-01

Lithium-ion (Li-ion) is the most commonly used battery chemistry in portable applications nowadays. Accurate State-of-Charge (SoC) and remaining run-time (t,) calculation for portable devices is important for the user convenience and to prolong the lifetime of batteries. A new SoC algorithm for

Adaptive State of Charge Estimation for Li-Ion Batteries Based on an Unscented Kalman Filter with an Enhanced Battery Model

Directory of Open Access Journals (Sweden)

Yuanyuan Liu

2013-08-01

Full Text Available Accurate estimation of the state of charge (SOC of batteries is one of the key problems in a battery management system. This paper proposes an adaptive SOC estimation method based on unscented Kalman filter algorithms for lithium (Li-ion batteries. First, an enhanced battery model is proposed to include the impacts due to different discharge rates and temperatures. An adaptive joint estimation of the battery SOC and battery internal resistance is then presented to enhance system robustness with battery aging. The SOC estimation algorithm has been developed and verified through experiments on different types of Li-ion batteries. The results indicate that the proposed method provides an accurate SOC estimation and is computationally efficient, making it suitable for embedded system implementation.

Ni-MH batteries state-of-charge prediction based on immune evolutionary network

International Nuclear Information System (INIS)

Cheng Bo; Zhou Yanlu; Zhang Jiexin; Wang Junping; Cao Binggang

2009-01-01

Based on clonal selection theory, an improved immune evolutionary strategy is presented. Compared with conventional evolutionary strategy algorithm (CESA) and immune monoclonal strategy algorithm (IMSA), experimental results show that the proposed algorithm is of high efficiency and can effectively prevent premature convergence. A three-layer feed-forward neural network is presented to predict state-of-charge (SOC) of Ni-MH batteries. Initially, partial least square regression (PLSR) is used to select input variables. Then, five variables, battery terminal voltage, voltage derivative, voltage second derivative, discharge current and battery temperature, are selected as the inputs of NN. In order to overcome the weakness of BP algorithm, the new algorithm is adopted to train weights. Finally, under the state of dynamic power cycle, the predicted SOC and the actual SOC are compared to verify the proposed neural network with acceptable accuracy (5%).

Method of estimating the State-of-Charge and of the use time left of a rechageable battery, and apparatus for executing such a method

NARCIS (Netherlands)

Bergveld, Hendrik Johannes; Pop, V.; Notten, Petrus Henricus Laurentius

2006-01-01

Disclosed is a method of estimating the state-of-charge of a rechargeable battery, taking into account the factors battery spread and ageing. The method comprises the steps of: determining the starting state-of-charge of the battery by measuring the voltage across the battery and converting this

High rate partial-state-of-charge operation of VRLA batteries

Science.gov (United States)

Moseley, Patrick T.

The world market for 12 V SLI batteries currently stands at around US$ 12 billion. The lack of a serious challenge from other battery types has allowed lead-acid products to serve this market exclusively, with minimal demand for product improvement through research and development, and a sharp competition has, over time, cut sales prices to commodity levels. The electrochemical storage of energy in automobiles now faces the possibility of a major change, in the form of the proposed 36/42 V electrical systems for vehicles that remain primarily powered by internal combustion engines, and of the hybrid electric vehicle. The duty cycle for these two applications sees the battery held at a partial-state-of-charge (PSoC) for most of its life and required to supply, and to accept, charge at unprecedented rates. The remarkable advances achieved with VRLA battery technology for electric vehicles during the past 8-10 years will be of only passing value in overcoming the challenges posed by high rate PSoC service in 36/42 V and HEV duty. This is because the failure modes seen in PSoC are quite different from those faced in EV (deep cycle) use. The replacement of the 12 V SLI will not take place rapidly. However, if the applications which take its place are to be satisfied by a lead-acid product (probably VRLA), rather than by a battery of a different chemistry, a program of development as successful as that mounted for deep cycle duty will be required. The present phase of the Advanced Lead-Acid Battery Consortium (ALABC) R&D program has begun to shed light on those aspects of the function of a VRLA battery which currently limit its life in high rate PSoC duty. The program is also pursuing the several technologies which show promise of overcoming those limits, including multiple tab plate design, mass transport facilitation and minor component (both beneficial and detrimental impurity) management. This paper presents a brief review of the changes which are taking place in

Discrimination of Li-ion batteries based on Hamming network using discharging-charging voltage pattern recognition for improved state-of-charge estimation

Energy Technology Data Exchange (ETDEWEB)

Kim, Jonghoon; Lee, Seongjun; Cho, B.H. [Power Electronics System Laboratory, School of Electrical Engineering and Computer Science, Seoul National University, Seoul 151-744 (Korea, Republic of)

2011-02-15

Differences in electrochemical characteristics among Li-ion batteries and factors such as temperature and ageing result in erroneous state-of-charge (SoC) estimation when using the existing extended Kalman filter (EKF) algorithm. This study presents an application of the Hamming neural network to the identification of suitable battery model parameters for improved SoC estimation. The discharging-charging voltage (DCV) patterns of ten fresh Li-ion batteries are measured, together with the battery parameters, as representative patterns. Through statistical analysis, the Hamming network is applied for identification of the representative DCV pattern that matches most closely of the pattern of the arbitrary battery to be measured. Model parameters of the representative battery are then applied to estimate the SoC of the arbitrary battery using the EKF. This avoids the need for repeated parameter measurement. Using model parameters selected by the proposed method, all SoC estimates (off-line and on-line) based on the EKF are within {+-}5% of the values estimated by ampere-hour counting. (author)

Charging performance of automotive batteries-An underestimated factor influencing lifetime and reliable battery operation

Science.gov (United States)

Sauer, Dirk Uwe; Karden, Eckhard; Fricke, Birger; Blanke, Holger; Thele, Marc; Bohlen, Oliver; Schiffer, Julia; Gerschler, Jochen Bernhard; Kaiser, Rudi

Dynamic charge acceptance and charge acceptance under constant voltage charging conditions are for two reasons essential for lead-acid battery operation: energy efficiency in applications with limited charging time (e.g. PV systems or regenerative braking in vehicles) and avoidance of accelerated ageing due to sulphation. Laboratory tests often use charge regimes which are beneficial for the battery life, but which differ significantly from the operating conditions in the field. Lead-acid batteries in applications with limited charging time and partial-state-of-charge operation are rarely fully charged due to their limited charge acceptance. Therefore, they suffer from sulphation and early capacity loss. However, when appropriate charging strategies are applied most of the lost capacity and thus performance for the user may be recovered. The paper presents several aspects of charging regimes and charge acceptance. Theoretical and experimental investigations show that temperature is the most critical parameter. Full charging within short times can be achieved only at elevated temperatures. A strong dependency of the charge acceptance during charging pulses on the pre-treatment of the battery can be observed, which is not yet fully understood. But these effects have a significant impact on the fuel efficiency of micro-hybrid electric vehicles.

Method and apparatus for controlling battery charging in a hybrid electric vehicle

Science.gov (United States)

Phillips, Anthony Mark; Blankenship, John Richard; Bailey, Kathleen Ellen; Jankovic, Miroslava

2003-06-24

A starter/alternator system (24) for hybrid electric vehicle (10) having an internal combustion engine (12) and an energy storage device (34) has a controller (30) coupled to the starter/alternator (26). The controller (30) has a state of charge manager (40) that monitors the state of charge of the energy storage device. The controller has eight battery state-of-charge threshold values that determine the hybrid operating mode of the hybrid electric vehicle. The value of the battery state-of-charge relative to the threshold values is a factor in the determination of the hybrid mode, for example; regenerative braking, charging, battery bleed, boost. The starter/alternator may be operated as a generator or a motor, depending upon the mode.

Evaluation of several state-of-charge algorithms

Science.gov (United States)

Espinosa, J. M.; Martin, M. E.; Burke, A. F.

1988-09-01

One of the important needs in marketing an electric vehicle is a device which reliably indicates battery state-of-charge for all types of driving. The purpose of the state-of-charge indicator is analogous to a gas gauge in an internal combustion engine powered vehicle. Many different approaches have been tried to accurately predict battery state-of-charge. This report evaluates several of these approaches. Four different algorithms were implemented into software on an IBM PC and tested using a battery test database for ALCO 2200 lead-acid batteries generated at the INEL. The database was obtained under controlled conditions which compare with the battery response in real EV use. Each algorithm is described in detail as to theory and operational functionality. Also discussed is the hardware and data requirements particular to implementing the individual algorithms. The algorithms were evaluated for accuracy using constant power, stepped power, and simulated vehicle (SFUDS79) discharge profiles. Attempts were made to explain the cause of differences between the predicted and actual state-of-charge and to provide possible remedies to correct them. Recommendations for future work on battery state-of-charge indicators are presented that utilize the hardware and software now in place in the INEL Battery Laboratory.

Accuracy analysis of the State-of-Charge and remaining run-time determination for lithium-ion batteries

NARCIS (Netherlands)

Pop, V.; Bergveld, H.J.; Notten, P.H.L.; Op het Veld, J.H.G.; Regtien, Paulus P.L.

2008-01-01

This paper describes the various error sources in a real-time State-of-Charge (SoC) evaluation system and their effects on the overall accuracy in the calculation of the remaining run-time of a battery-operated system. The SoC algorithm for Li-ion batteries studied in this paper combines direct

Accuracy analysis of the state-of-charge and remaining run-time determination for lithium-ion batteries

NARCIS (Netherlands)

Pop, V.; Bergveld, H.J.; Notten, P.H.L.; Op het Veld, J.H.G.; Regtien, P.P.L.

2009-01-01

This paper describes the various error sources in a real-time State-of-Charge (SoC) evaluation system and their effects on the overall accuracy in the calculation of the remaining run-time of a battery-operated system. The SoC algorithm for Li-ion batteries studied in this paper combines direct

Influence of plug-in hybrid electric vehicle charging strategies on charging and battery degradation costs

International Nuclear Information System (INIS)

Lunz, Benedikt; Yan, Zexiong; Gerschler, Jochen Bernhard; Sauer, Dirk Uwe

2012-01-01

The profitability of plug-in hybrid electric vehicles (PHEVs) is significantly influenced by battery aging and electricity costs. Therefore a simulation model for PHEVs in the distribution grid is presented which allows to compare the influence of different charging strategies on these costs. The simulation is based on real-world driving behavior and European Energy Exchange (EEX) intraday prices for obtaining representative results. The analysis of comprehensive lithium-ion battery aging tests performed within this study shows that especially high battery states of charge (SOCs) decrease battery lifetime, whereas the cycling of batteries at medium SOCs only has a minor contribution to aging. Charging strategies that take into account the previously mentioned effects are introduced, and the SOC distributions and cycle loads of the vehicle battery are investigated. It can be shown that appropriate charging strategies significantly increase battery lifetime and reduce charging costs at the same time. Possible savings due to lifetime extension of the vehicle battery are approximately two times higher than revenues due to energy trading. The findings of this work indicate that car manufacturers and energy/mobility providers have to make efforts for developing intelligent charging strategies to reduce mobility costs and thus foster the introduction of electric mobility. - Highlights: ► Modeling of PHEVs based on real-world driving behavior and electricity prices. ► Consideration of battery degradation for the calculation of mobility costs. ► Smart charging decreases battery degradation and electricity costs simultaneously. ► Reduction of battery degradation costs is around two times higher than reduction of electricity costs.

State of Charge Estimation of Lithium-Ion Batteries Using an Adaptive Cubature Kalman Filter

Directory of Open Access Journals (Sweden)

Bizhong Xia

2015-06-01

Full Text Available Accurate state of charge (SOC estimation is of great significance for a lithium-ion battery to ensure its safe operation and to prevent it from over-charging or over-discharging. However, it is difficult to get an accurate value of SOC since it is an inner sate of a battery cell, which cannot be directly measured. This paper presents an Adaptive Cubature Kalman filter (ACKF-based SOC estimation algorithm for lithium-ion batteries in electric vehicles. Firstly, the lithium-ion battery is modeled using the second-order resistor-capacitor (RC equivalent circuit and parameters of the battery model are determined by the forgetting factor least-squares method. Then, the Adaptive Cubature Kalman filter for battery SOC estimation is introduced and the estimated process is presented. Finally, two typical driving cycles, including the Dynamic Stress Test (DST and New European Driving Cycle (NEDC are applied to evaluate the performance of the proposed method by comparing with the traditional extended Kalman filter (EKF and cubature Kalman filter (CKF algorithms. Experimental results show that the ACKF algorithm has better performance in terms of SOC estimation accuracy, convergence to different initial SOC errors and robustness against voltage measurement noise as compared with the traditional EKF and CKF algorithms.

Online available capacity prediction and state of charge estimation based on advanced data-driven algorithms for lithium iron phosphate battery

International Nuclear Information System (INIS)

Deng, Zhongwei; Yang, Lin; Cai, Yishan; Deng, Hao; Sun, Liu

2016-01-01

The key technology of a battery management system is to online estimate the battery states accurately and robustly. For lithium iron phosphate battery, the relationship between state of charge and open circuit voltage has a plateau region which limits the estimation accuracy of voltage-based algorithms. The open circuit voltage hysteresis requires advanced online identification algorithms to cope with the strong nonlinear battery model. The available capacity, as a crucial parameter, contributes to the state of charge and state of health estimation of battery, but it is difficult to predict due to comprehensive influence by temperature, aging and current rates. Aim at above problems, the ampere-hour counting with current correction and the dual adaptive extended Kalman filter algorithms are combined to estimate model parameters and state of charge. This combination presents the advantages of less computation burden and more robustness. Considering the influence of temperature and degradation, the data-driven algorithm namely least squares support vector machine is implemented to predict the available capacity. The state estimation and capacity prediction methods are coupled to improve the estimation accuracy at different temperatures among the lifetime of battery. The experiment results verify the proposed methods have excellent state and available capacity estimation accuracy. - Highlights: • A dual adaptive extended Kalman filter is used to estimate parameters and states. • A correction term is introduced to consider the effect of current rates. • The least square support vector machine is used to predict the available capacity. • The experiment results verify the proposed state and capacity prediction methods.

Evaluation of Model Based State of Charge Estimation Methods for Lithium-Ion Batteries

Directory of Open Access Journals (Sweden)

Zhongyue Zou

2014-08-01

Full Text Available Four model-based State of Charge (SOC estimation methods for lithium-ion (Li-ion batteries are studied and evaluated in this paper. Different from existing literatures, this work evaluates different aspects of the SOC estimation, such as the estimation error distribution, the estimation rise time, the estimation time consumption, etc. The equivalent model of the battery is introduced and the state function of the model is deduced. The four model-based SOC estimation methods are analyzed first. Simulations and experiments are then established to evaluate the four methods. The urban dynamometer driving schedule (UDDS current profiles are applied to simulate the drive situations of an electrified vehicle, and a genetic algorithm is utilized to identify the model parameters to find the optimal parameters of the model of the Li-ion battery. The simulations with and without disturbance are carried out and the results are analyzed. A battery test workbench is established and a Li-ion battery is applied to test the hardware in a loop experiment. Experimental results are plotted and analyzed according to the four aspects to evaluate the four model-based SOC estimation methods.

Fuzzy logic-based battery charge controller

International Nuclear Information System (INIS)

Daoud, A.; Midoun, A.

2006-01-01

Microchip's 8-bit microcontroller PICI6F877, where the fuzzy controller reads the voltage of the battery to determine the state of charge and then controls the amount of current flowing into battery by using a DC to DC buck converter.(Author)

An Improved Wireless Battery Charging System

OpenAIRE

Woo-Seok Lee; Jin-Hak Kim; Shin-Young Cho; Il-Oun Lee

2018-01-01

This paper presents a direct wireless battery charging system. The output current of the series-series compensated wireless power transfer (SS-WPT) system is used as a current source, and the output voltage of AC-DC converter controls the current source. Therefore, the proposed wireless battery charging system needs no battery charging circuit to carry out charging profiles, and can solve space constraints and thermal problems in many battery applications. In addition, the proposed wireless b...

State-of-Charge Balancing Control of a Modular Multilevel Converter with an Integrated Battery Energy Storage

Directory of Open Access Journals (Sweden)

Hui Liang

2018-04-01

Full Text Available With the fast development of the electric vehicle industry, the reuse of second-life batteries in vehicles are becoming more attractive, however, both the state-of-charge (SOC inconsistency and the capacity inconsistency of second-life batteries have limits in their utilization. This paper focuses on the second-life batteries applied battery energy storage system (BESS based on modular multilevel converter (MMC. By analyzing the power flow characteristics among all sources within the MMC-BESS, a three-level SOC equilibrium control strategy aiming to battery capacity inconsistency is proposed to balance the energy of batteries, which includes SOC balance among three-phase legs, SOC balance between the upper and lower arms of each phase, and SOC balance of submodules within each arm. In battery charging and discharging control, by introducing power regulations based on battery capacity proportion of three-phase legs, capacity deviation between the upper and lower’s arm, and the capacity coefficient of the submodule into the SOC feedback control loop, SOC balance of all battery modules is accomplished, thus effectively improving the energy utilization of second-life battery energy storage system. Finally, the effectiveness and feasibility of the proposed methods are verified by results obtained from simulations and the experimental platform.

Adaptive state-of-charge indication system for a Li-ion battery-powered devices

NARCIS (Netherlands)

Pop, V.; Danilov, D.; Bergveld, H.J.; Notten, P.H.L.; Regtien, P.P.L.

2006-01-01

Accurate State-of-Charge (SoC) and remammg run-time indication for portable devices is important for the user convenience and to prolong the lifetime of batteries. So far, no one succeeded in coming up with a SoC system that is accurate enough under all realistic user conditions. An algorithm that

Overview of Lithium-Ion Battery Modeling Methods for State-of-Charge Estimation in Electrical Vehicles

DEFF Research Database (Denmark)

Jinhao, Meng; Guangzhao, Luo; Ricco, Mattia

2018-01-01

As a critical indictor in the Battery Management System (BMS), State of Charge (SOC) is closely related to the reliable and safe operation of lithium-ion (Li-ion) batteries. Model-based methods are an effective solution for accurate and robust SOC estimation, the performance of which heavily relies...... on the battery model. This paper mainly focuses on battery modeling methods, which have the potential to be used in a model-based SOC estimation structure. Battery modeling methods are classified into four categories on the basis of their theoretical foundations, and their expressions and features are detailed....... Furthermore, the four battery modeling methods are compared in terms of their pros and cons. Future research directions are also presented. In addition, after optimizing the parameters of the battery models by a Genetic Algorithm (GA), four typical battery models including a combined model, two RC Equivalent...

A combination Kalman filter approach for State of Charge estimation of lithium-ion battery considering model uncertainty

International Nuclear Information System (INIS)

Li, Yanwen; Wang, Chao; Gong, Jinfeng

2016-01-01

An accurate battery State of Charge estimation plays an important role in battery electric vehicles. This paper makes two contributions to the existing literature. (1) A recursive least squares method with fuzzy adaptive forgetting factor has been presented to update the model parameters close to the real value more quickly. (2) The statistical information of the innovation sequence obeying chi-square distribution has been introduced to identify model uncertainty, and a novel combination algorithm of strong tracking unscented Kalman filter and adaptive unscented Kalman filter has been developed to estimate SOC (State of Charge). Experimental results indicate that the novel algorithm has a good performance in estimating the battery SOC against initial SOC errors and voltage sensor drift. A comparison with the unscented Kalman filter-based algorithms and adaptive unscented Kalman filter-based algorithms shows that the proposed SOC estimation method has better accuracy, robustness and convergence behavior. - Highlights: • Recursive least squares method with fuzzy adaptive forgetting factor is presented. • The innovation obeying chi-square distribution is used to identify uncertainty. • A combination Karman filter approach for State of Charge estimation is presented. • The performance of the proposed method is verified by comparison results.

Rapid Estimation Method for State of Charge of Lithium-Ion Battery Based on Fractional Continual Variable Order Model

Directory of Open Access Journals (Sweden)

Xin Lu

2018-03-01

Full Text Available In recent years, the fractional order model has been employed to state of charge (SOC estimation. The non integer differentiation order being expressed as a function of recursive factors defining the fractality of charge distribution on porous electrodes. The battery SOC affects the fractal dimension of charge distribution, therefore the order of the fractional order model varies with the SOC at the same condition. This paper proposes a new method to estimate the SOC. A fractional continuous variable order model is used to characterize the fractal morphology of charge distribution. The order identification results showed that there is a stable monotonic relationship between the fractional order and the SOC after the battery inner electrochemical reaction reaches balanced. This feature makes the proposed model particularly suitable for SOC estimation when the battery is in the resting state. Moreover, a fast iterative method based on the proposed model is introduced for SOC estimation. The experimental results showed that the proposed iterative method can quickly estimate the SOC by several iterations while maintaining high estimation accuracy.

?Just-in-Time? Battery Charge Depletion Control for PHEVs and E-REVs for Maximum Battery Life

Energy Technology Data Exchange (ETDEWEB)

DeVault, Robert C [ORNL

2009-01-01

Conventional methods of vehicle operation for Plug-in Hybrid Vehicles first discharge the battery to a minimum State of Charge (SOC) before switching to charge sustaining operation. This is very demanding on the battery, maximizing the number of trips ending with a depleted battery and maximizing the distance driven on a depleted battery over the vehicle s life. Several methods have been proposed to reduce the number of trips ending with a deeply discharged battery and also eliminate the need for extended driving on a depleted battery. An optimum SOC can be maintained for long battery life before discharging the battery so that the vehicle reaches an electric plug-in destination just as the battery reaches the minimum operating SOC. These Just-in-Time methods provide maximum effective battery life while getting virtually the same electricity from the grid.

State of Charge Estimation Based on Microscopic Driving Parameters for Electric Vehicle's Battery

Directory of Open Access Journals (Sweden)

Enjian Yao

2013-01-01

Full Text Available Recently, battery-powered electric vehicle (EV has received wide attention due to less pollution during use, low noise, and high energy efficiency and is highly expected to improve urban air quality and then mitigate energy and environmental pressure. However, the widespread use of EV is still hindered by limited battery capacity and relatively short cruising range. This paper aims to propose a state of charge (SOC estimation method for EV’s battery necessary for route planning and dynamic route guidance, which can help EV drivers to search for the optimal energy-efficient routes and to reduce the risk of running out of electricity before arriving at the destination or charging station. Firstly, by analyzing the variation characteristics of power consumption rate with initial SOC and microscopic driving parameters (instantaneous speed and acceleration, a set of energy consumption rate models are established according to different operation modes. Then, the SOC estimation model is proposed based on the presented EV power consumption model. Finally, by comparing the estimated SOC with the measured SOC, the proposed SOC estimation method is proved to be highly accurate and effective, which can be well used in EV route planning and navigation systems.

Electric vehicle battery charging controller

DEFF Research Database (Denmark)

2016-01-01

The present invention provides an electric vehicle charging controller. The charging controller comprises a first interface connectable to an electric vehicle charge source for receiving a charging current, a second interface connectable to an electric vehicle for providing the charging current...... to a battery management system in the electric vehicle to charge a battery therein, a first communication unit for receiving a charging message via a communication network, and a control unit for controlling a charging current provided from the charge source to the electric vehicle, the controlling at least...... in part being performed in response to a first information associated with a charging message received by the first communication unit...

Peukert-Equation-Based State-of-Charge Estimation for LiFePO4 Batteries Considering the Battery Thermal Evolution Effect

Directory of Open Access Journals (Sweden)

Jiale Xie

2018-05-01

Full Text Available To achieve accurate state-of-charge (SoC estimation for LiFePO4 (lithium iron phosphate batteries under harsh conditions, this paper resorts to the Peukert’s law to accommodate different temperatures and load excitations. By analyzing battery heat generation and dissipation, a thermal evolution model (TEM is elaborated and exploited for on-line parameter identification of the equivalent circuit model (ECM. Then, a SoC estimation framework is proposed based on the Adaptive Extended Kalman Filter (AEKF algorithm. Experimental results on a LiFePO4 pack subject to the Federal Urban Driving Schedule (FUDS profile under different temperatures and initial states suggest that the proposed SoC estimator provides good robustness and accuracy against changing temperature and highly dynamic loads.

Microprocessor controlled pulse charge and testing of batteries

International Nuclear Information System (INIS)

Kerezov, A.; Gishin, S.; Ivanov, Ratcho; Savov, S.

2002-01-01

The principle of the developed new method for pulse charge of batteries with microprocessor control of the electrochemical processes is the use of current pulses with microprocessor control of the period and the amplitude according to the dynamically changing state of the electrochemical system. In order to realize the method described above a programmable current source was developed. It is connected with a Personal Computer via RS232 standard serial interface in order to control the electrochemical processes. The parameters to be set, the graphical presentation of the pulse current and tension, the used quantity of electricity and electrical energy for every pulse and for the process as a hole are shown on the PC display. In order to test dry-charged and wet-charged batteries a specialized current generator was developed. It is connected also with a Personal Computer via R5232 standard serial interface in order to con-trol the testing of the starting capability of the batteries according to the requirements of the Bulgarian State Standard Ell 60095-1. (Author)

Battery pack state of charge balancing algorithm for cascaded H-Bridge multilevel converters

DEFF Research Database (Denmark)

Máthé, Lászlo; Burlacu, Paul Dan; Schaltz, Erik

2016-01-01

For most of the Multilevel Converter (MC) applications a commonly discussed issue is the maintenance of balance between the energy storage elements from the SubModules (SM). In applications where a battery pack is also part of the SM storage, such as STATCOMs or motor drives, the SM voltage...... is not in linear relation with the State Of Charge (SOC) of the entire battery; thus, the balancing becomes more cumbersome. A method to balance the SOC of the battery packs in a system using cascaded H-Bridge is proposed in this paper. The method uses nearest level control followed by sorting and selection based...... on the SOC of the battery packs. Based on the simulation results the number of switching is reduced considerably compared to the method where the phase shifted PWM is used. In addition, the time needed to achieve the balanced SOC is also reduced. The proposed method has been verified through experiments...

A Novel Methodology for Estimating State-Of-Charge of Li-Ion Batteries Using Advanced Parameters Estimation

Directory of Open Access Journals (Sweden)

Ibrahim M. Safwat

2017-11-01

Full Text Available State-of-charge (SOC estimations of Li-ion batteries have been the focus of many research studies in previous years. Many articles discussed the dynamic model’s parameters estimation of the Li-ion battery, where the fixed forgetting factor recursive least square estimation methodology is employed. However, the change rate of each parameter to reach the true value is not taken into consideration, which may tend to poor estimation. This article discusses this issue, and proposes two solutions to solve it. The first solution is the usage of a variable forgetting factor instead of a fixed one, while the second solution is defining a vector of forgetting factors, which means one factor for each parameter. After parameters estimation, a new idea is proposed to estimate state-of-charge (SOC of the Li-ion battery based on Newton’s method. Also, the error percentage and computational cost are discussed and compared with that of nonlinear Kalman filters. This methodology is applied on a 36 V 30 A Li-ion pack to validate this idea.

Estimation of State of Charge for Two Types of Lithium-Ion Batteries by Nonlinear Predictive Filter for Electric Vehicles

Directory of Open Access Journals (Sweden)

Yin Hua

2015-04-01

Full Text Available Estimation of state of charge (SOC is of great importance for lithium-ion (Li-ion batteries used in electric vehicles. This paper presents a state of charge estimation method using nonlinear predictive filter (NPF and evaluates the proposed method on the lithium-ion batteries with different chemistries. Contrary to most conventional filters which usually assume a zero mean white Gaussian process noise, the advantage of NPF is that the process noise in NPF is treated as an unknown model error and determined as a part of the solution without any prior assumption, and it can take any statistical distribution form, which improves the estimation accuracy. In consideration of the model accuracy and computational complexity, a first-order equivalent circuit model is applied to characterize the battery behavior. The experimental test is conducted on the LiCoO2 and LiFePO4 battery cells to validate the proposed method. The results show that the NPF method is able to accurately estimate the battery SOC and has good robust performance to the different initial states for both cells. Furthermore, the comparison study between NPF and well-established extended Kalman filter for battery SOC estimation indicates that the proposed NPF method has better estimation accuracy and converges faster.

A contact-less method to evaluate the state of charge of nickel batteries using Foucault's eddy currents

Science.gov (United States)

Mancier, V.; Metrot, A.; Willmann, P.

A nickel hydroxide electrode and a commercial battery have been studied by a new and contact-less impedance method, based on Foucault's eddy currents, with the aim of determining their state of charge. Four different current line distributions have been employed and the impedance versus time graphs obtained show a linear variation of this impedance during charge and discharge for all configurations. This new method allows the determination of the state of charge and, furthermore some "artifacts" obvious on these graphs may be useful to detect a deterioration of the studied material.

State of charge classification for lithium-ion batteries using impedance based features

Directory of Open Access Journals (Sweden)

M. P. Felder

2017-09-01

Full Text Available Currently, the electrification of the drive train of passenger cars takes place, and the task of obtaining precise knowledge about the condition of the on board batteries gains importance. Due to a flat open circuit voltage (OCV to state of charge (SoC characteristic of lithium ion batteries, methods employed in applications with other cell chemistries cannot be adapted. Exploiting the higher significance of the impedance for state estimation for that chemistry, new impedance based features are proposed by this work. To evaluate the suitability of these features, simulations have been conducted using a simplified on-board power supply net as excitation source. The simulation outcome has been investigated regarding the cross correlation factor rxy and in a polynomial regression scenario. The results of the simulations show a best case error below 1 % SoC, which is 3 percentage points lower than using terminal voltage and impedance. When increasing the measurement uncertainty, the difference remains around 2 percent points.

Develop improved battery charger (Turbo-Z Battery Charging System). Final report

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-09-01

The output of this project was a flexible control board. The control board can be used to control a variety of rapid battery chargers. The control module will reduce development cost of rapid battery charging hardware. In addition, PEPCO's proprietary battery charging software have been pre-programmed into the control microprocessor. This product is being applied to the proprietary capacitive charging system now under development.

A Novel Active Online State of Charge Based Balancing Approach for Lithium-Ion Battery Packs during Fast Charging Process in Electric Vehicles

Directory of Open Access Journals (Sweden)

Xiudong Cui

2017-11-01

Full Text Available Abstract: Non-uniformity of Lithium-ion cells in a battery pack is inevitable and has become the bottleneck to the pack capacity, especially in the fast charging process. Therefore, a balancing approach is essentially required. This paper proposes an active online cell balancing approach in a fast charging process using the state of charge (SOC as balancing criterion. The goal of this approach is to complete pack balancing within the limited charging time. An adaptive extended Kalman filter (AEKF is applied to estimate the pack cell SOC during the charging process to obtain accurate results under modeling errors and measurement noises. To implement the proposed AEKF, only one additional current sensor is required to obtain the current of each cell required for the SOC estimation. An experimental platform is established to verify the effectiveness of the proposed approach. The results show that the proposed balancing approach with the SOC as a balancing criterion can overcome the challenges of non-uniformity and flat voltage plateau and charge more capacity into a LiFePO4 battery pack than those with the terminal voltage as a balancing criterion in the fast charging process.

State-of-charge estimation in lithium-ion batteries: A particle filter approach

Science.gov (United States)

Tulsyan, Aditya; Tsai, Yiting; Gopaluni, R. Bhushan; Braatz, Richard D.

2016-11-01

The dynamics of lithium-ion batteries are complex and are often approximated by models consisting of partial differential equations (PDEs) relating the internal ionic concentrations and potentials. The Pseudo two-dimensional model (P2D) is one model that performs sufficiently accurately under various operating conditions and battery chemistries. Despite its widespread use for prediction, this model is too complex for standard estimation and control applications. This article presents an original algorithm for state-of-charge estimation using the P2D model. Partial differential equations are discretized using implicit stable algorithms and reformulated into a nonlinear state-space model. This discrete, high-dimensional model (consisting of tens to hundreds of states) contains implicit, nonlinear algebraic equations. The uncertainty in the model is characterized by additive Gaussian noise. By exploiting the special structure of the pseudo two-dimensional model, a novel particle filter algorithm that sweeps in time and spatial coordinates independently is developed. This algorithm circumvents the degeneracy problems associated with high-dimensional state estimation and avoids the repetitive solution of implicit equations by defining a 'tether' particle. The approach is illustrated through extensive simulations.

Prediction Model of Battery State of Charge and Control Parameter Optimization for Electric Vehicle

Directory of Open Access Journals (Sweden)

Bambang Wahono

2015-07-01

Full Text Available This paper presents the construction of a battery state of charge (SOC prediction model and the optimization method of the said model to appropriately control the number of parameters in compliance with the SOC as the battery output objectives. Research Centre for Electrical Power and Mechatronics, Indonesian Institute of Sciences has tested its electric vehicle research prototype on the road, monitoring its voltage, current, temperature, time, vehicle velocity, motor speed, and SOC during the operation. Using this experimental data, the prediction model of battery SOC was built. Stepwise method considering multicollinearity was able to efficiently develops the battery prediction model that describes the multiple control parameters in relation to the characteristic values such as SOC. It was demonstrated that particle swarm optimization (PSO succesfully and efficiently calculated optimal control parameters to optimize evaluation item such as SOC based on the model.

Kalman filtering state of charge estimation for battery management system based on a stochastic fuzzy neural network battery model

International Nuclear Information System (INIS)

Xu Long; Wang Junping; Chen Quanshi

2012-01-01

Highlights: ► A novel extended Kalman Filtering SOC estimation method based on a stochastic fuzzy neural network (SFNN) battery model is proposed. ► The SFNN which has filtering effect on noisy input can model the battery nonlinear dynamic with high accuracy. ► A robust parameter learning algorithm for SFNN is studied so that the parameters can converge to its true value with noisy data. ► The maximum SOC estimation error based on the proposed method is 0.6%. - Abstract: Extended Kalman filtering is an intelligent and optimal means for estimating the state of a dynamic system. In order to use extended Kalman filtering to estimate the state of charge (SOC), we require a mathematical model that can accurately capture the dynamics of battery pack. In this paper, we propose a stochastic fuzzy neural network (SFNN) instead of the traditional neural network that has filtering effect on noisy input to model the battery nonlinear dynamic. Then, the paper studies the extended Kalman filtering SOC estimation method based on a SFNN model. The modeling test is realized on an 80 Ah Ni/MH battery pack and the Federal Urban Driving Schedule (FUDS) cycle is used to verify the SOC estimation method. The maximum SOC estimation error is 0.6% compared with the real SOC obtained from the discharging test.

Fast Charging and Smart Charging Tests for Electric Vehicles Batteries Using Renewable Energy

DEFF Research Database (Denmark)

Forero Camacho, Oscar Mauricio; Mihet-Popa, Lucian

2016-01-01

Electric Vehicles (EV) technologies are still relatively new and under strong development. Although some standardized solutions are being promoted and becoming a new trend, there is an outstanding need for common platforms and sharing of knowledge and core technologies. This paper presents......, and forced and pulsed power. The aim of the tests has been to study the impact of smart charging and fast charging on the power system, on the battery state of health and degradation, and to find out the limitations of the batteries for a Smart Grid. The paper outlines the advantages and disadvantages...

Fabrication of solid-state secondary battery using semiconductors and evaluation of its charge/discharge characteristics

Science.gov (United States)

Sasaki, Atsuya; Sasaki, Akito; Hirabayashi, Hideaki; Saito, Shuichi; Aoki, Katsuaki; Kataoka, Yoshinori; Suzuki, Koji; Yabuhara, Hidehiko; Ito, Takahiro; Takagi, Shigeyuki

2018-04-01

Li-ion batteries have attracted interest for use as storage batteries. However, the risk of fire has not yet been resolved. Although solid Li-ion batteries are possible alternatives, their performance characteristics are unsatisfactory. Recently, research on utilizing the accumulation of carriers at the trap levels of semiconductors has been performed. However, the detailed charge/discharge characteristics and principles have not been reported. In this report, we attempted to form new n-type oxide semiconductor/insulator/p-type oxide semiconductor structures. The battery characteristics of these structures were evaluated by charge/discharge measurements. The obtained results clearly indicated the characteristics of rechargeable batteries. Furthermore, the fabricated structure accumulated an approximately 5000 times larger number of carriers than a parallel plate capacitor. Additionally, by constructing circuit models based on the experimental results, the charge/discharge mechanisms were considered. This is the first detailed experimental report on a rechargeable battery that operates without the double injection of ions and electrons.

Enabling fast charging - Battery thermal considerations

Science.gov (United States)

Keyser, Matthew; Pesaran, Ahmad; Li, Qibo; Santhanagopalan, Shriram; Smith, Kandler; Wood, Eric; Ahmed, Shabbir; Bloom, Ira; Dufek, Eric; Shirk, Matthew; Meintz, Andrew; Kreuzer, Cory; Michelbacher, Christopher; Burnham, Andrew; Stephens, Thomas; Francfort, James; Carlson, Barney; Zhang, Jiucai; Vijayagopal, Ram; Hardy, Keith; Dias, Fernando; Mohanpurkar, Manish; Scoffield, Don; Jansen, Andrew N.; Tanim, Tanvir; Markel, Anthony

2017-11-01

Battery thermal barriers are reviewed with regards to extreme fast charging. Present-day thermal management systems for battery electric vehicles are inadequate in limiting the maximum temperature rise of the battery during extreme fast charging. If the battery thermal management system is not designed correctly, the temperature of the cells could reach abuse temperatures and potentially send the cells into thermal runaway. Furthermore, the cell and battery interconnect design needs to be improved to meet the lifetime expectations of the consumer. Each of these aspects is explored and addressed as well as outlining where the heat is generated in a cell, the efficiencies of power and energy cells, and what type of battery thermal management solutions are available in today's market. Thermal management is not a limiting condition with regard to extreme fast charging, but many factors need to be addressed especially for future high specific energy density cells to meet U.S. Department of Energy cost and volume goals.

Accurate Online Full Charge Capacity Modeling of Smartphone Batteries

OpenAIRE

Hoque, Mohammad A.; Siekkinen, Matti; Koo, Jonghoe; Tarkoma, Sasu

2016-01-01

Full charge capacity (FCC) refers to the amount of energy a battery can hold. It is the fundamental property of smartphone batteries that diminishes as the battery ages and is charged/discharged. We investigate the behavior of smartphone batteries while charging and demonstrate that the battery voltage and charging rate information can together characterize the FCC of a battery. We propose a new method for accurately estimating FCC without exposing low-level system details or introducing new ...

State of Charge Estimation for Lithium-Ion Battery with a Temperature-Compensated Model

Directory of Open Access Journals (Sweden)

Shichun Yang

2017-10-01

Full Text Available Accurate estimation of the state of charge (SOC of batteries is crucial in a battery management system. Many studies on battery SOC estimation have been investigated recently. Temperature is an important factor that affects the SOC estimation accuracy while it is still not adequately addressed at present. This paper proposes a SOC estimator based on a new temperature-compensated model with extended Kalman Filter (EKF. The open circuit voltage (OCV, capacity, and resistance and capacitance (RC parameters in the estimator are temperature dependent so that the estimator can maintain high accuracy at various temperatures. The estimation accuracy decreases when applied in high current continuous discharge, because the equivalent polarization resistance decreases as the discharge current increases. Therefore, a polarization resistance correction coefficient is proposed to tackle this problem. The estimator also demonstrates a good performance in dynamic operating conditions. However, the equivalent circuit model shows huge uncertainty in the low SOC region, so measurement noise variation is proposed to improve the estimation accuracy there.

A New State of Charge Estimation Method for LiFePO4 Battery Packs Used in Robots

Directory of Open Access Journals (Sweden)

Han-Pang Huang

2013-04-01

Full Text Available The accurate state of charge (SOC estimation of the LiFePO4 battery packs used in robot applications is required for better battery life cycle, performance, reliability, and economic issues. In this paper, a new SOC estimation method, “Modified ECE + EKF”, is proposed. The method is the combination of the modified Equivalent Coulombic Efficiency (ECE method and the Extended Kalman Filter (EKF method. It is based on the zero-state hysteresis battery model, and adopts the EKF method to correct the initial value used in the Ah counting method. Experimental results show that the proposed technique is superior to the traditional techniques, such as ECE + EKF and ECE + Unscented Kalman Filter (UKF, and the accuracy of estimation is within 1%.

A New State of Charge Estimation Method for LiFePO4 Battery Packs Used in Robots

Energy Technology Data Exchange (ETDEWEB)

NONE

2013-04-15

The accurate state of charge (SOC) estimation of the LiFePO4 battery packs used in robot applications is required for better battery life cycle, performance, reliability, and economic issues. In this paper, a new SOC estimation method, ''Modified ECE + EKF'', is proposed. The method is the combination of the modified Equivalent Coulombic Efficiency (ECE) method and the Extended Kalman Filter (EKF) method. It is based on the zero-state hysteresis battery model, and adopts the EKF method to correct the initial value used in the Ah counting method. Experimental results show that the proposed technique is superior to the traditional techniques, such as ECE + EKF and ECE + Unscented Kalman Filter (UKF), and the accuracy of estimation is within 1%.

Micro-hybrid electric vehicle application of valve-regulated lead-acid batteries in absorbent glass mat technology: Testing a partial-state-of-charge operation strategy

Energy Technology Data Exchange (ETDEWEB)

Schaeck, S.; Stoermer, A.O.; Hockgeiger, E. [BMW Group, Powertrain Development, Energy Storage, Hufelandstrasse 4, 80788 Muenchen (Germany)

2009-05-01

The BMW Group has launched two micro-hybrid functions in high volume models in order to contribute to reduction of fuel consumption in modern passenger cars. Both the brake energy regeneration (BER) and the auto-start-stop function (ASSF) are based on the conventional 14 V vehicle electrical system and current series components with only little modifications. An intelligent control algorithm of the alternator enables recuperative charging in braking and coasting phases, known as BER. By switching off the internal combustion engine at a vehicle standstill the idling fuel consumption is effectively reduced by ASSF. By reason of economy and package a lead-acid battery is used as electrochemical energy storage device. The BMW Group assembles valve-regulated lead-acid (VRLA) batteries in absorbent glass mat (AGM) technology in the micro-hybrid electrical power system since special challenges arise for the batteries. By field data analysis a lower average state-of-charge (SOC) due to partial state-of-charge (PSOC) operation and a higher cycling rate due to BER and ASSF are confirmed in this article. Similar to a design of experiment (DOE) like method we present a long-term lab investigation. Two types of 90 Ah VRLA AGM batteries are operated with a test bench profile that simulates the micro-hybrid vehicle electrical system under varying conditions. The main attention of this lab testing is focused on capacity loss and charge acceptance over cycle life. These effects are put into context with periodically refresh charging the batteries in order to prevent accelerated battery aging due to hard sulfation. We demonstrate the positive effect of refresh chargings concerning preservation of battery charge acceptance. Furthermore, we observe moderate capacity loss over 90 full cycles both at 25 C and at 3 C battery temperature. (author)

Micro-hybrid electric vehicle application of valve-regulated lead-acid batteries in absorbent glass mat technology: Testing a partial-state-of-charge operation strategy

Science.gov (United States)

Schaeck, S.; Stoermer, A. O.; Hockgeiger, E.

The BMW Group has launched two micro-hybrid functions in high volume models in order to contribute to reduction of fuel consumption in modern passenger cars. Both the brake energy regeneration (BER) and the auto-start-stop function (ASSF) are based on the conventional 14 V vehicle electrical system and current series components with only little modifications. An intelligent control algorithm of the alternator enables recuperative charging in braking and coasting phases, known as BER. By switching off the internal combustion engine at a vehicle standstill the idling fuel consumption is effectively reduced by ASSF. By reason of economy and package a lead-acid battery is used as electrochemical energy storage device. The BMW Group assembles valve-regulated lead-acid (VRLA) batteries in absorbent glass mat (AGM) technology in the micro-hybrid electrical power system since special challenges arise for the batteries. By field data analysis a lower average state-of-charge (SOC) due to partial state-of-charge (PSOC) operation and a higher cycling rate due to BER and ASSF are confirmed in this article. Similar to a design of experiment (DOE) like method we present a long-term lab investigation. Two types of 90 Ah VRLA AGM batteries are operated with a test bench profile that simulates the micro-hybrid vehicle electrical system under varying conditions. The main attention of this lab testing is focused on capacity loss and charge acceptance over cycle life. These effects are put into context with periodically refresh charging the batteries in order to prevent accelerated battery aging due to hard sulfation. We demonstrate the positive effect of refresh chargings concerning preservation of battery charge acceptance. Furthermore, we observe moderate capacity loss over 90 full cycles both at 25 °C and at 3 °C battery temperature.

State of charge monitoring of vanadium redox flow batteries using half cell potentials and electrolyte density

Science.gov (United States)

Ressel, Simon; Bill, Florian; Holtz, Lucas; Janshen, Niklas; Chica, Antonio; Flower, Thomas; Weidlich, Claudia; Struckmann, Thorsten

2018-02-01

The operation of vanadium redox flow batteries requires reliable in situ state of charge (SOC) monitoring. In this study, two SOC estimation approaches for the negative half cell are investigated. First, in situ open circuit potential measurements are combined with Coulomb counting in a one-step calibration of SOC and Nernst potential which doesn't need additional reference SOCs. In-sample and out-of-sample SOCs are estimated and analyzed, estimation errors ≤ 0.04 are obtained. In the second approach, temperature corrected in situ electrolyte density measurements are used for the first time in vanadium redox flow batteries for SOC estimation. In-sample and out-of-sample SOC estimation errors ≤ 0.04 demonstrate the feasibility of this approach. Both methods allow recalibration during battery operation. The actual capacity obtained from SOC calibration can be used in a state of health model.

Modeling and state-of-charge prediction of lithium-ion battery and ultracapacitor hybrids with a co-estimator

International Nuclear Information System (INIS)

Wang, Yujie; Liu, Chang; Pan, Rui; Chen, Zonghai

2017-01-01

The modeling and state-of-charge estimation of the batteries and ultracapacitors are crucial to the battery/ultracapacitor hybrid energy storage system. In recent years, the model based state estimators are welcomed widely, since they can adjust the gain according to the error between the model predictions and measurements timely. In most of the existing algorithms, the model parameters are either configured by theoretical values or identified off-line without adaption. But in fact, the model parameters always change continuously with loading wave or self-aging, and the lack of adaption will reduce the estimation accuracy significantly. To overcome this drawback, a novel co-estimator is proposed to estimate the model parameters and state-of-charge simultaneously. The extended Kalman filter is employed for parameter updating. To reduce the convergence time, the recursive least square algorithm and the off-line identification method are used to provide initial values with small deviation. The unscented Kalman filter is employed for the state-of-charge estimation. Because the unscented Kalman filter takes not only the measurement uncertainties but also the process uncertainties into account, it is robust to the noise. Experiments are executed to explore the robustness, stability and precision of the proposed method. - Highlights: • A co-estimator is proposed to estimate the model parameters and state-of-charge. • The extended Kalman filter is used for model parameter adaption. • The unscented Kalman filter is designed for state estimation with strong robust. • The dynamic profiles are employed to verify the proposed co-estimator.

Method and apparatus for indicating electric charge remaining in batteries based on electrode weight and center of gravity

Science.gov (United States)

Rouhani, S.Z.

1996-12-03

In most electrochemical batteries which generate electricity through the reaction of a battery electrode with an electrolyte solution, the chemical composition, and thus the weight and density, of the electrode changes as the battery discharges. The invention measures a parameter of the battery which changes as the weight of the electrode changes as the battery discharges and relates that parameter to the value of the parameter when the battery is fully charged and when the battery is functionally discharged to determine the state-of-charge of the battery at the time the parameter is measured. In one embodiment, the weight of a battery electrode or electrode unit is measured to determine the state-of-charge. In other embodiments, where a battery electrode is located away from the geometrical center of the battery, the position of the center of gravity of the battery or shift in the position of the center of gravity of the battery is measured (the position of the center of gravity changes with the change in weight of the electrode) and indicates the state-of-charge of the battery. 35 figs.

Device and Method for Continuously Equalizing the Charge State of Lithium Ion Battery Cells

Science.gov (United States)

Schwartz, Paul D. (Inventor); Martin, Mark N. (Inventor); Roufberg, Lewis M. (Inventor)

2015-01-01

A method of equalizing charge states of individual cells in a battery includes measuring a previous cell voltage for each cell, measuring a previous shunt current for each cell, calculating, based on the previous cell voltage and the previous shunt current, an adjusted cell voltage for each cell, determining a lowest adjusted cell voltage from among the calculated adjusted cell voltages, and calculating a new shunt current for each cell.

Self-healing liquid/solid state battery

Science.gov (United States)

Burke, Paul J.; Chung, Brice H.V.; Phadke, Satyajit R.; Ning, Xiaohui; Sadoway, Donald R.

2018-02-27

A battery system that exchanges energy with an external device is provided. The battery system includes a positive electrode having a first metal or alloy, a negative electrode having a second metal or alloy, and an electrolyte including a salt of the second metal or alloy. The positive electrode, the negative electrode, and the electrolyte are in a liquid phase at an operating temperature during at least one portion of operation. The positive electrode is entirely in a liquid phase in one charged state and includes a solid phase in another charged state. The solid phase of the positive electrode includes a solid intermetallic formed by the first and the second metals or alloys. Methods of storing electrical energy from an external circuit using such a battery system are also provided.

An adaptive state of charge estimation approach for lithium-ion series-connected battery system

Science.gov (United States)

Peng, Simin; Zhu, Xuelai; Xing, Yinjiao; Shi, Hongbing; Cai, Xu; Pecht, Michael

2018-07-01

Due to the incorrect or unknown noise statistics of a battery system and its cell-to-cell variations, state of charge (SOC) estimation of a lithium-ion series-connected battery system is usually inaccurate or even divergent using model-based methods, such as extended Kalman filter (EKF) and unscented Kalman filter (UKF). To resolve this problem, an adaptive unscented Kalman filter (AUKF) based on a noise statistics estimator and a model parameter regulator is developed to accurately estimate the SOC of a series-connected battery system. An equivalent circuit model is first built based on the model parameter regulator that illustrates the influence of cell-to-cell variation on the battery system. A noise statistics estimator is then used to attain adaptively the estimated noise statistics for the AUKF when its prior noise statistics are not accurate or exactly Gaussian. The accuracy and effectiveness of the SOC estimation method is validated by comparing the developed AUKF and UKF when model and measurement statistics noises are inaccurate, respectively. Compared with the UKF and EKF, the developed method shows the highest SOC estimation accuracy.

Battery-powered transport systems. Possible methods of automatically charging drive batteries

Energy Technology Data Exchange (ETDEWEB)

1981-03-01

In modern driverless transport systems, not only easy maintenance of the drive battery is important but also automatic charging during times of standstill. Some systems are presented; one system is pointed out in particular in which 100 batteries can be charged at the same time.

Estimation of State of Charge of Lithium-Ion Batteries Used in HEV Using Robust Extended Kalman Filtering

Directory of Open Access Journals (Sweden)

Suleiman M. Sharkh

2012-04-01

Full Text Available A robust extended Kalman filter (EKF is proposed as a method for estimation of the state of charge (SOC of lithium-ion batteries used in hybrid electric vehicles (HEVs. An equivalent circuit model of the battery, including its electromotive force (EMF hysteresis characteristics and polarization characteristics is used. The effect of the robust EKF gain coefficient on SOC estimation is analyzed, and an optimized gain coefficient is determined to restrain battery terminal voltage from fluctuating. Experimental and simulation results are presented. SOC estimates using the standard EKF are compared with the proposed robust EKF algorithm to demonstrate the accuracy and precision of the latter for SOC estimation.

Battery State-of-Charge and Parameter Estimation Algorithm Based on Kalman Filter

DEFF Research Database (Denmark)

Dragicevic, Tomislav; Sucic, Stjepan; Guerrero, Josep M.

2013-01-01

Electrochemical battery is the most widely used energy storage technology, finding its application in various devices ranging from low power consumer electronics to utility back-up power. All types of batteries show highly non-linear behaviour in terms of dependence of internal parameters...... on operating conditions, momentary replenishment and a number of past charge/discharge cycles. A good indicator for the quality of overall customer service in any battery based application is the availability and reliability of these informations, as they point out important runtime variables...

Incremental Capacity Analysis of a Lithium-Ion Battery Pack for Different Charging Rates

DEFF Research Database (Denmark)

Kalogiannis, Theodoros; Stroe, Daniel-Ioan; Nyborg, Jonas

2017-01-01

-depth investigation of two battery packs composed of 14 Lithium-ion cells each; for the purpose of evaluating the applicability and the challenges of the ICA on a battery pack level by means of different charging current rates. Also, at a certain charging current, the influence of the temperature on the ICA curves......Incremental Capacity Analysis (ICA) is a method used to investigate the capacity state of health of batteries by tracking the electrochemical properties of the cell. It is based on the differentiation of the battery capacity over the battery voltage, for a full or a partial cycle regarding...

Effect of thermal contact resistances on fast charging of large format lithium ion batteries

International Nuclear Information System (INIS)

Ye, Yonghuang; Saw, Lip Huat; Shi, Yixiang; Somasundaram, Karthik; Tay, Andrew A.O.

2014-01-01

Highlights: • The effect of thermal contact resistance on thermal performance of large format lithium ion batteries. • The effect of temperature gradient on electrochemical performance of large format batteries during fast charging. • The thermal performance of lithium ion battery utilizing pulse charging protocol. • Suggestions on battery geometry design optimization to improve thermal performance. - Abstract: A two dimensional electrochemical thermal model is developed on the cross-plane of a laminate stack plate pouch lithium ion battery to study the thermal performance of large format batteries. The effect of thermal contact resistance is taken into consideration, and is found to greatly increase the maximum temperature and temperature gradient of the battery. The resulting large temperature gradient would induce in-cell non-uniformity of charging-discharging current and state of health. Simply increasing the cooling intensity is inadequate to reduce the maximum temperature and narrow down the temperature difference due to the poor cross-plane thermal conductivity. Pulse charging protocol does not help to mitigate the temperature difference on the bias of same total charging time, because of larger time-averaged heat generation rate than constant current charging. Suggestions on battery geometry optimizations for both prismatic/pouch battery and cylindrical battery are proposed to reduce the maximum temperature and mitigate the temperature gradient within the lithium ion battery

State of Charge Balancing Control of a Multi-Functional Battery Energy Storage System Based on a 11-Level Cascaded Multilevel PWM Converter

DEFF Research Database (Denmark)

Wang, Songcen; Teodorescu, Remus; Máthé, Lászlo

2015-01-01

This paper focuses on modeling and SOC (State of Charge) balancing control of lithium-ion battery energy storage system based on cascaded multilevel converter for both grid integration and electric vehicle propulsion applications. The equivalent electrical circuit model of lithium-ion battery...

Robust Online State of Charge Estimation of Lithium-Ion Battery Pack Based on Error Sensitivity Analysis

Directory of Open Access Journals (Sweden)

Ting Zhao

2015-01-01

Full Text Available Accurate and reliable state of charge (SOC estimation is a key enabling technique for large format lithium-ion battery pack due to its vital role in battery safety and effective management. This paper tries to make three contributions to existing literatures through robust algorithms. (1 Observer based SOC estimation error model is established, where the crucial parameters on SOC estimation accuracy are determined by quantitative analysis, being a basis for parameters update. (2 The estimation method for a battery pack in which the inconsistency of cells is taken into consideration is proposed, ensuring all batteries’ SOC ranging from 0 to 1, effectively avoiding the battery overcharged/overdischarged. Online estimation of the parameters is also presented in this paper. (3 The SOC estimation accuracy of the battery pack is verified using the hardware-in-loop simulation platform. The experimental results at various dynamic test conditions, temperatures, and initial SOC difference between two cells demonstrate the efficacy of the proposed method.

A Consistent Derivation of the Impedance of a Lithium-Ion Battery Electrode and its Dependency on the State-of-Charge

International Nuclear Information System (INIS)

Schönleber, M.; Uhlmann, C.; Braun, P.; Weber, A.; Ivers-Tiffée, E.

2017-01-01

Highlights: •A derivation of the impedance model of a Lithium-Ion battery electrode is given. •The dependency of all partial impedances on the State-of-Charge is revealed. •The lasting disagreement in how to model solid-state diffusion is settled. •A solid starting point to derive models of any complexity is provided. •The connection between differential capacity and solid-state diffusion is revealed. -- Abstract: A derivation of the fundamental impedance of a Lithium-Ion battery electrode is given, exemplarily conducted for a solid thin-film electrode. The focus of this derivation is not on developing a model which is able to reproduce the exact behaviour of a given electrode, but rather on deriving its fundamental characteristics from few and intuitive assumptions in a simple and transparent way. It is thus shown, that the fundamental impedance of a solid thin-film electrode consists of an RC-element for charge-transfer, a Finite-Length Warburg element for diffusion in the electrolyte and a Finite-Space Warburg element for diffusion in the solid-state. The use of a Finite-Length Warburg element with a serially connected capacitor for modelling diffusion in the solid-state is thus indicated to be physically questionable. In addition, the theoretically expected behaviour of charge-transfer and solid-state diffusion on the degree of lithiation (State-of-Charge) is derived and discussed.

Quantacell: powerful charging of quantum batteries

International Nuclear Information System (INIS)

Binder, Felix C; Vinjanampathy, Sai; Modi, Kavan; Goold, John

2015-01-01

We study the problem of charging a quantum battery in finite time. We demonstrate an analytical optimal protocol for the case of a single qubit. Extending this analysis to an array of N qubits, we demonstrate that an N-fold advantage in power per qubit can be achieved when global operations are permitted. The exemplary analytic argument for this quantum advantage in the charging power is backed up by numerical analysis using optimal control techniques. It is demonstrated that the quantum advantage for power holds when, with cyclic operation in mind, initial and final states are required to be separable. (paper)

Estimating state of charge and health of lithium-ion batteries with guided waves using built-in piezoelectric sensors/actuators

Science.gov (United States)

Ladpli, Purim; Kopsaftopoulos, Fotis; Chang, Fu-Kuo

2018-04-01

This work presents the feasibility of monitoring state of charge (SoC) and state of health (SoH) of lithium-ion pouch batteries with acousto-ultrasonic guided waves. The guided waves are propagated and sensed using low-profile, built-in piezoelectric disc transducers that can be retrofitted onto off-the-shelf batteries. Both experimental and analytical studies are performed to understand the relationship between guided waves generated in a pitch-catch mode and battery SoC/SoH. The preliminary experiments on representative pouch cells show that the changes in time of flight (ToF) and signal amplitude (SA) resulting from shifts in the guided wave signals correlate strongly with the electrochemical charge-discharge cycling and aging. An analytical acoustic model is developed to simulate the variations in electrode moduli and densities during cycling, which correctly validates the absolute values and range of experimental ToF. It is further illustrated via a statistical study that ToF and SA can be used in a prediction model to accurately estimate SoC/SoH. Additionally, by using multiple sensors in a network configuration on the same battery, a significantly more reliable and accurate SoC/SoH prediction is achieved. The indicative results from this study can be extended to develop a unified guided-wave-based framework for SoC/SoH monitoring of many lithium-ion battery applications.

Enabling fast charging – Battery thermal considerations

International Nuclear Information System (INIS)

Keyser, Matthew; Pesaran, Ahmad; Li, Qibo; Santhanagopalan, Shriram; Smith, Kandler

2017-01-01

Battery thermal barriers are reviewed with regards to extreme fast charging. Present-day thermal management systems for battery electric vehicles are inadequate in limiting the maximum temperature rise of the battery during extreme fast charging. If the battery thermal management system is not designed correctly, the temperature of the cells could reach abuse temperatures and potentially send the cells into thermal runaway. Furthermore, the cell and battery interconnect design needs to be improved to meet the lifetime expectations of the consumer. Each of these aspects is explored and addressed as well as outlining where the heat is generated in a cell, the efficiencies of power and energy cells, and what type of battery thermal management solutions are available in today’s market. Here, thermal management is not a limiting condition with regard to extreme fast charging, but many factors need to be addressed especially for future high specific energy density cells to meet U.S. Department of Energy cost and volume goals.

Adaptive estimation of the electromotive force of the lithium-ion battery after current interruption for an accurate state-of-charge and capacity determination

International Nuclear Information System (INIS)

Waag, Wladislaw; Sauer, Dirk Uwe

2013-01-01

Highlights: • New adaptive approach for the EMF estimation. • The EMF is estimated by observing the voltage change after the current interruption. • The approach enables an accurate SoC and capacity determination. • Real-time capable algorithm. - Abstract: The online estimation of battery states and parameters is one of the challenging tasks when battery is used as a part of the pure electric or hybrid energy system. For the determination of the available energy stored in the battery, the knowledge of the present state-of-charge (SOC) and capacity of the battery is required. For SOC and capacity determination often the estimation of the battery electromotive force (EMF) is employed. The electromotive force can be measured as an open circuit voltage (OCV) of the battery when a significant time has elapsed since the current interruption. This time may take up to some hours for lithium-ion batteries and is needed to eliminate the influence of the diffusion overvoltages. This paper proposes a new approach to estimate the EMF by considering the OCV relaxation process within only some first minutes after the current interruption. The approach is based on an online fitting of an OCV relaxation model to the measured OCV relaxation curve. This model is based on an equivalent circuit consisting of a voltage source (represents the EMF) in series with the parallel connection of the resistance and a constant phase element (CPE). Based on this fitting the model parameters are determined and the EMF is estimated. The application of this method is exemplarily demonstrated for the state-of-charge and capacity estimation of the lithium-ion battery in an electrical vehicle. In the presented example the battery capacity is determined with the maximal inaccuracy of 2% using the EMF estimated at two different levels of state-of-charge. The real-time capability of the proposed algorithm is proven by its implementation on a low-cost 16-bit microcontroller (Infineon XC2287)

Particle-filtering-based estimation of maximum available power state in Lithium-Ion batteries

International Nuclear Information System (INIS)

Burgos-Mellado, Claudio; Orchard, Marcos E.; Kazerani, Mehrdad; Cárdenas, Roberto; Sáez, Doris

2016-01-01

Highlights: • Approach to estimate the state of maximum power available in Lithium-Ion battery. • Optimisation problem is formulated on the basis of a non-linear dynamic model. • Solutions of the optimisation problem are functions of state of charge estimates. • State of charge estimates computed using particle filter algorithms. - Abstract: Battery Energy Storage Systems (BESS) are important for applications related to both microgrids and electric vehicles. If BESS are used as the main energy source, then it is required to include adequate procedures for the estimation of critical variables such as the State of Charge (SoC) and the State of Health (SoH) in the design of Battery Management Systems (BMS). Furthermore, in applications where batteries are exposed to high charge and discharge rates it is also desirable to estimate the State of Maximum Power Available (SoMPA). In this regard, this paper presents a novel approach to the estimation of SoMPA in Lithium-Ion batteries. This method formulates an optimisation problem for the battery power based on a non-linear dynamic model, where the resulting solutions are functions of the SoC. In the battery model, the polarisation resistance is modelled using fuzzy rules that are function of both SoC and the discharge (charge) current. Particle filtering algorithms are used as an online estimation technique, mainly because these algorithms allow approximating the probability density functions of the SoC and SoMPA even in the case of non-Gaussian sources of uncertainty. The proposed method for SoMPA estimation is validated using the experimental data obtained from an experimental setup designed for charging and discharging the Lithium-Ion batteries.

Battery Aging, Battery Charging and the Kinetic Battery Model : A First Exploration

NARCIS (Netherlands)

Jongerden, Marijn R.; Haverkort, Boudewijn R.; Bertrand, Nathalie; Bortolussi, Luca

2017-01-01

Rechargeable batteries are omnipresent and will be used more and more, for instance for wearables devices, electric vehicles or domestic energy storage. However, batteries can deliver power only for a limited time span. They slowly degrade with every charge-discharge cycle. This degradation needs to

Methods for thermodynamic evaluation of battery state of health

Science.gov (United States)

Yazami, Rachid; McMenamin, Joseph; Reynier, Yvan; Fultz, Brent T

2013-05-21

Described are systems and methods for accurately characterizing thermodynamic and materials properties of electrodes and battery systems and for characterizing the state of health of electrodes and battery systems. Measurement of physical attributes of electrodes and batteries corresponding to thermodynamically stabilized electrode conditions permit determination of thermodynamic parameters, including state functions such as the Gibbs free energy, enthalpy and entropy of electrode/electrochemical cell reactions, that enable prediction of important performance attributes of electrode materials and battery systems, such as energy, power density, current rate, cycle life and state of health. Also provided are systems and methods for charging a battery according to its state of health.

On-line adaptive battery impedance parameter and state estimation considering physical principles in reduced order equivalent circuit battery models part 2. Parameter and state estimation

Science.gov (United States)

Fleischer, Christian; Waag, Wladislaw; Heyn, Hans-Martin; Sauer, Dirk Uwe

2014-09-01

Lithium-ion battery systems employed in high power demanding systems such as electric vehicles require a sophisticated monitoring system to ensure safe and reliable operation. Three major states of the battery are of special interest and need to be constantly monitored. These include: battery state of charge (SoC), battery state of health (capacity fade determination, SoH), and state of function (power fade determination, SoF). The second paper concludes the series by presenting a multi-stage online parameter identification technique based on a weighted recursive least quadratic squares parameter estimator to determine the parameters of the proposed battery model from the first paper during operation. A novel mutation based algorithm is developed to determine the nonlinear current dependency of the charge-transfer resistance. The influence of diffusion is determined by an on-line identification technique and verified on several batteries at different operation conditions. This method guarantees a short response time and, together with its fully recursive structure, assures a long-term stable monitoring of the battery parameters. The relative dynamic voltage prediction error of the algorithm is reduced to 2%. The changes of parameters are used to determine the states of the battery. The algorithm is real-time capable and can be implemented on embedded systems.

High Reversibility of Soft Electrode Materials in All-solid-state Batteries

Directory of Open Access Journals (Sweden)

Atsushi eSakuda

2016-05-01

Full Text Available All-solid-state batteries using inorganic solid electrolytes (SEs are considered to be ideal batteries for electric vehicles (EVs and plug-in hybrid electric vehicles (PHEVs because they are potentially safer than conventional lithium-ion batteries (LIBs. In addition, all-solid-state batteries are expected to have long battery lives owing to the inhibition of chemical side reactions because only lithium ions move through the typically used inorganic SEs. The development of high-energy (more than 300 Wh kg-1 secondary batteries has been eagerly anticipated for years. The application of high-capacity electrode active materials is essential for fabricating such batteries. Recently, we proposed metal polysulfides as new electrode materials. These materials show higher conductivity and density than sulfur, which is advantageous for fabricating batteries with relatively higher energy density. Lithium niobium sulfides, such as Li3NbS4, have relatively high density, conductivity, and rate capability among metal polysulfide materials, and batteries with these materials have capacities high enough to potentially exceed the gravimetric energy density of conventional LIBs.Favorable solid-solid contact between the electrode and electrolyte particles is a key factor for fabricating high performance all-solid-state batteries. Conventional oxide-based positive electrode materials tend to be given rise to cracks during fabrication and/or charge-discharge processes. Here we report all-solid-state cells using lithium niobium sulfide as a positive electrode material, where favorable solid-solid contact was established by using lithium sulfide electrode materials because of their high processability. Cracks were barely observed in the electrode particles in the all-solid-state cells before or after charging and discharging with a high capacity of approx. 400 mAh g-1, suggesting that the lithium niobium sulfide electrode charged and discharged without experiencing

State of Charge Estimation Using the Extended Kalman Filter for Battery Management Systems Based on the ARX Battery Model

Directory of Open Access Journals (Sweden)

Hongjie Wu

2013-01-01

Full Text Available State of charge (SOC is a critical factor to guarantee that a battery system is operating in a safe and reliable manner. Many uncertainties and noises, such as fluctuating current, sensor measurement accuracy and bias, temperature effects, calibration errors or even sensor failure, etc. pose a challenge to the accurate estimation of SOC in real applications. This paper adds two contributions to the existing literature. First, the auto regressive exogenous (ARX model is proposed here to simulate the battery nonlinear dynamics. Due to its discrete form and ease of implemention, this straightforward approach could be more suitable for real applications. Second, its order selection principle and parameter identification method is illustrated in detail in this paper. The hybrid pulse power characterization (HPPC cycles are implemented on the 60AH LiFePO4 battery module for the model identification and validation. Based on the proposed ARX model, SOC estimation is pursued using the extended Kalman filter. Evaluation of the adaptability of the battery models and robustness of the SOC estimation algorithm are also verified. The results indicate that the SOC estimation method using the Kalman filter based on the ARX model shows great performance. It increases the model output voltage accuracy, thereby having the potential to be used in real applications, such as EVs and HEVs.

Hierarchical control of a photovoltaic/battery based DC microgrid including electric vehicle wireless charging station

DEFF Research Database (Denmark)

Xiao, Zhao xia; Fan, Haodong; Guerrero, Josep M.

2017-01-01

In this paper, the hierarchical control strategy of a photovoltaic/battery based dc microgrid is presented for electric vehicle (EV) wireless charging. Considering irradiance variations, battery charging/discharging requirements, wireless power transmission characteristics, and onboard battery...... coils, receiving coils and compensation capacitors, the wireless power transmission system is designed to be resonant when it is operating at the rated power, with the aim to achieve the optimum transmission system efficiency. Simulation and experimental results of the hierarchical control...... charging power change and other factors, the possible operation states are obtained. A hierarchical control strategy is established, which includes central and local controllers. The central controller is responsible for the selection and transfer of operation states and the management of the local...

Equivalent circuit model parameters of a high-power Li-ion battery: Thermal and state of charge effects

Science.gov (United States)

Gomez, Jamie; Nelson, Ruben; Kalu, Egwu E.; Weatherspoon, Mark H.; Zheng, Jim P.

2011-05-01

Equivalent circuit model (EMC) of a high-power Li-ion battery that accounts for both temperature and state of charge (SOC) effects known to influence battery performance is presented. Electrochemical impedance measurements of a commercial high power Li-ion battery obtained in the temperature range 20 to 50 °C at various SOC values was used to develop a simple EMC which was used in combination with a non-linear least squares fitting procedure that used thirteen parameters for the analysis of the Li-ion cell. The experimental results show that the solution and charge transfer resistances decreased with increase in cell operating temperature and decreasing SOC. On the other hand, the Warburg admittance increased with increasing temperature and decreasing SOC. The developed model correlations that are capable of being used in process control algorithms are presented for the observed impedance behavior with respect to temperature and SOC effects. The predicted model parameters for the impedance elements Rs, Rct and Y013 show low variance of 5% when compared to the experimental data and therefore indicates a good statistical agreement of correlation model to the actual experimental values.

A model-based adaptive state of charge estimator for a lithium-ion battery using an improved adaptive particle filter

International Nuclear Information System (INIS)

Ye, Min; Guo, Hui; Cao, Binggang

2017-01-01

Highlights: • Propose an improved adaptive particle swarm filter method. • The SoC estimation method for the battery based on the adaptive particle swarm filter is presented. • The algorithm is validated by the case study of different aged extent batteries. • The effectiveness and applicability of the algorithm are validated by the LiPB batteries. - Abstract: Obtaining accurate parameters, state of charge (SoC) and capacity of a lithium-ion battery is crucial for a battery management system, and establishing a battery model online is complex. In addition, the errors and perturbations of the battery model dramatically increase throughout the battery lifetime, making it more challenging to model the battery online. To overcome these difficulties, this paper provides three contributions: (1) To improve the robustness of the adaptive particle filter algorithm, an error analysis method is added to the traditional adaptive particle swarm algorithm. (2) An online adaptive SoC estimator based on the improved adaptive particle filter is presented; this estimator can eliminate the estimation error due to battery degradation and initial SoC errors. (3) The effectiveness of the proposed method is verified using various initial states of lithium nickel manganese cobalt oxide (NMC) cells and lithium-ion polymer (LiPB) batteries. The experimental analysis shows that the maximum errors are less than 1% for both the voltage and SoC estimations and that the convergence time of the SoC estimation decreased to 120 s.

State-of-charge inconsistency estimation of lithium-ion battery pack using mean-difference model and extended Kalman filter

Science.gov (United States)

Zheng, Yuejiu; Gao, Wenkai; Ouyang, Minggao; Lu, Languang; Zhou, Long; Han, Xuebing

2018-04-01

State-of-charge (SOC) inconsistency impacts the power, durability and safety of the battery pack. Therefore, it is necessary to measure the SOC inconsistency of the battery pack with good accuracy. We explore a novel method for modeling and estimating the SOC inconsistency of lithium-ion (Li-ion) battery pack with low computation effort. In this method, a second-order RC model is selected as the cell mean model (CMM) to represent the overall performance of the battery pack. A hypothetical Rint model is employed as the cell difference model (CDM) to evaluate the SOC difference. The parameters of mean-difference model (MDM) are identified with particle swarm optimization (PSO). Subsequently, the mean SOC and the cell SOC differences are estimated by using extended Kalman filter (EKF). Finally, we conduct an experiment on a small Li-ion battery pack with twelve cells connected in series. The results show that the evaluated SOC difference is capable of tracking the changing of actual value after a quick convergence.

Electrical circuit for checking the state of charge of a vehicle battery. Elektrische Schaltung zur Kontrolle des Ladezustandes einer Batterie in Kraftfahrzeugen

Energy Technology Data Exchange (ETDEWEB)

Gamulescu, A

1981-05-27

The invention concerns an electrical circuit for checking the state of charge of a vehicle battery. The circuit consists of a transistor, whose collector is connected via a series resistance and a Zener diode to the positive pole of the battery. The breakdown voltage of the Zener diode is about 12 volts. The emitter of the transistor is connected via an LED to earth. A second LED is connected in parallel with the collector-emitter circuit of the transistor, which works via a voltage divider. This voltage divider reduces the voltage at the LED with the transistor which is conducting to about 0.7 volts. A second Zener diode connected via a series resistance to the positive pole is also provided. Its breakdown voltage is 15 volts.

Estimation of State of Charge of a Lithium-Ion Battery Pack for Electric Vehicles Using an Adaptive Luenberger Observer

Directory of Open Access Journals (Sweden)

Yuan Zou

2010-09-01

Full Text Available In order to safely and efficiently use the power as well as to extend the lifetime of the traction battery pack, accurate estimation of State of Charge (SoC is very important and necessary. This paper presents an adaptive observer-based technique for estimating SoC of a lithium-ion battery pack used in an electric vehicle (EV. The RC equivalent circuit model in ADVISOR is applied to simulate the lithium-ion battery pack. The parameters of the battery model as a function of SoC, are identified and optimized using the numerically nonlinear least squares algorithm, based on an experimental data set. By means of the optimized model, an adaptive Luenberger observer is built to estimate online the SoC of the lithium-ion battery pack. The observer gain is adaptively adjusted using a stochastic gradient approach so as to reduce the error between the estimated battery output voltage and the filtered battery terminal voltage measurement. Validation results show that the proposed technique can accurately estimate SoC of the lithium-ion battery pack without a heavy computational load.

Photovoltaic battery charging experience in the Philippines

Energy Technology Data Exchange (ETDEWEB)

Navarro, S.T. Jr.

1997-12-01

With the turn of the century, people in remote areas still live without electricity. Conventional electrification will hardly reach the remaining 50% of the population of the Philippines in remote areas. With photovoltaic technology, the delivery of electricity to remote areas can be sustainable. Malalison island was chosen as a project site for electrification using photovoltaic technology. With the fragile balance of ecology and seasonal income in this island, the PV electrification proved to be a better option than conventional fossil based electrification. The Solar Battery Charging Station (SBCS) was used to suit the economic and geographical condition of the island. Results showed that the system can charge as many as three batteries in a day for an average fee of $0.54 per battery. Charging is measured by an ampere-hour counter to determine the exact amount of charge the battery received. The system was highly accepted by the local residents and the demand easily outgrew the system within four months. A technical, economic and social evaluation was done. A recovery period of seven years and five months is expected when competed with the conventional battery charging in the mainland. The technical, economic, institutional and social risks faced by the project were analyzed. Statistics showed that there is a potential of 920,000 households that can benefit from PV electrification in the Philippines. The data and experiences gained in this study are valuable in designing SBCS for remote unelectrified communities in the Philippines and other developing countries.

New battery model considering thermal transport and partial charge stationary effects in photovoltaic off-grid applications

Science.gov (United States)

Sanz-Gorrachategui, Iván; Bernal, Carlos; Oyarbide, Estanis; Garayalde, Erik; Aizpuru, Iosu; Canales, Jose María; Bono-Nuez, Antonio

2018-02-01

The optimization of the battery pack in an off-grid Photovoltaic application must consider the minimum sizing that assures the availability of the system under the worst environmental conditions. Thus, it is necessary to predict the evolution of the state of charge of the battery under incomplete daily charging and discharging processes and fluctuating temperatures over day-night cycles. Much of previous development work has been carried out in order to model the short term evolution of battery variables. Many works focus on the on-line parameter estimation of available charge, using standard or advanced estimators, but they are not focused on the development of a model with predictive capabilities. Moreover, normally stable environmental conditions and standard charge-discharge patterns are considered. As the actual cycle-patterns differ from the manufacturer's tests, batteries fail to perform as expected. This paper proposes a novel methodology to model these issues, with predictive capabilities to estimate the remaining charge in a battery after several solar cycles. A new non-linear state space model is proposed as a basis, and the methodology to feed and train the model is introduced. The new methodology is validated using experimental data, providing only 5% of error at higher temperatures than the nominal one.

A New Method for State of Charge Estimation of Lithium-Ion Battery Based on Strong Tracking Cubature Kalman Filter

Directory of Open Access Journals (Sweden)

Bizhong Xia

2015-11-01

Full Text Available The estimation of state of charge (SOC is a crucial evaluation index in a battery management system (BMS. The value of SOC indicates the remaining capacity of a battery, which provides a good guarantee of safety and reliability of battery operation. It is difficult to get an accurate value of the SOC, being one of the inner states. In this paper, a strong tracking cubature Kalman filter (STCKF based on the cubature Kalman filter is presented to perform accurate and reliable SOC estimation. The STCKF algorithm can adjust gain matrix online by introducing fading factor to the state estimation covariance matrix. The typical second-order resistor-capacitor model is used as the battery’s equivalent circuit model to dynamically simulate characteristics of the battery. The exponential-function fitting method accomplishes the task of relevant parameters identification. Then, the developed STCKF algorithm has been introduced in detail and verified under different operation current profiles such as Dynamic Stress Test (DST and New European Driving Cycle (NEDC. Making a comparison with extended Kalman filter (EKF and CKF algorithm, the experimental results show the merits of the STCKF algorithm in SOC estimation accuracy and robustness.

SOLID STATE BATTERIES WITH CONDUCTING POLYMERS

OpenAIRE

Bénière , F.; Boils , D.; Cánepa , H.; Franco , J.; Le Corre , A.; Louboutin , J.

1983-01-01

The conducting polymers like (CH)x are very interesting materials for electrodes in electrochemical cells. We have combined such electrodes with solid electrolytes to build "all solid-state" batteries. The first prototypes using a silver anode and a silver conducting electrolyte have been working satisfactorily since two years. The performances have been tested with many batteries to study the electrical properties as well as the thermodynamical parameters. A number of cycles of charge-discha...

Identifying Potential Markets for Behind-the-Meter Battery Energy Storage: A Survey of U.S. Demand Charges

Energy Technology Data Exchange (ETDEWEB)

McLaren, Joyce A [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Gagnon, Pieter J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Mullendore, Seth [Clean Energy Group, Montpelier, Vermont

2017-08-07

This paper presents the first publicly available comprehensive survey of the magnitude of demand charges for commercial customers across the United States -- a key predictor of the financial performance of behind-the-meter battery storage systems. Notably, the analysis estimates that there are nearly 5 million commercial customers in the United States who can subscribe to retail electricity tariffs that have demand charges in excess of $15 per kilowatt (kW), over a quarter of the 18 million commercial customers in total in the United States. While the economic viability of installing battery energy storage must be determined on a case-by-case basis, high demand charges are often cited as a critical factor in battery project economics. Increasing use of demand charges in utility tariffs and anticipated future declines in storage costs will only serve to unlock additional markets and strengthen existing ones.

Modeling charge polarization voltage for large lithium-ion batteries in electric vehicles

Directory of Open Access Journals (Sweden)

Yan Jiang

2013-06-01

Full Text Available Purpose: Polarization voltage of the lithium-ion battery is an important parameter that has direct influence on battery performance. The paper aims to analyze the impedance characteristics of the lithium-ion battery based on EIS data. Design/methodology/approach: The effects of currents, initial SOC of the battery on charge polarization voltage are investigated, which is approximately linear function of charge current. The change of charge polarization voltage is also analyzed with the gradient analytical method in the SOC domain. The charge polarization model with two RC networks is presented, and parts of model parameters like Ohmic resistance and charge transfer impedance are estimated by both EIS method and battery constant current testing method. Findings: This paper reveals that the Ohmic resistance accounts for much contribution to battery total polarization compared to charge transfer impedance. Practical implications: Experimental results demonstrate the efficacy of the model with the proposed identification method, which provides the foundation for battery charging optimization. Originality/value: The paper analyzed the impedance characteristics of the lithium-ion battery based on EIS data, presented a charge polarization model with two RC networks, and estimated parameters like Ohmic resistance and charge transfer impedance.

State of health detection for Lithium ion batteries in photovoltaic system

International Nuclear Information System (INIS)

Tsang, K.M.; Chan, W.L.

2013-01-01

Highlights: ► DC resistances of batteries. ► Fuzzy logic inference. ► SOH detection for battery. - Abstract: In many photovoltaic systems, rechargeable batteries are required to even out irregularities in solar irradiation. However, the health conditions of the batteries are crucial for the reliability of the overall system. In this paper, the equivalent DC resistances of Lithium ion battery cells of various health conditions during charging under different temperatures have been collected and the relationships between equivalent DC resistance, health condition and working temperature have been identified. The equivalent DC resistance can easily be obtained during the charging period of a battery by switching off the charging current periodically for a very short duration of time. A simple and effective battery charger with state of health (SOH) detection for Lithium ion battery cell has been developed based on the identified equivalent DC resistance. Experimental results are included to demonstrate the effectiveness of the proposed SOH determination scheme.

Process for charging batteries and circuit for carrying out the process. Verfahren zum Laden von Batterien und Schaltung zur Durchfuehrung des Verfahrens

Energy Technology Data Exchange (ETDEWEB)

Grauel, B

1992-03-05

The invention concerns a process for charging batteries and a circuit for carrying out the process. First, in a test routine, the battery temperature, the correct polarity of the battery and the actual state of battery charge are measured and the number of cells is determined from the battery no-load voltage. If this falls below the reference no-load voltage, the charging current is repeatedly switched on for a predetermined period of time, and the battery voltage is measured. If an equilibrium voltage predetermined by heating of the battery cells is determined, the battery is charged for a predetermined period of time, until the charged capacity has reached the nominal capacity. Then a maintenance charge to maintain the batter capacity is provided at a time space after the charge.

A novel Gaussian process regression model for state-of-health estimation of lithium-ion battery using charging curve

Science.gov (United States)

Yang, Duo; Zhang, Xu; Pan, Rui; Wang, Yujie; Chen, Zonghai

2018-04-01

The state-of-health (SOH) estimation is always a crucial issue for lithium-ion batteries. In order to provide an accurate and reliable SOH estimation, a novel Gaussian process regression (GPR) model based on charging curve is proposed in this paper. Different from other researches where SOH is commonly estimated by cycle life, in this work four specific parameters extracted from charging curves are used as inputs of the GPR model instead of cycle numbers. These parameters can reflect the battery aging phenomenon from different angles. The grey relational analysis method is applied to analyze the relational grade between selected features and SOH. On the other hand, some adjustments are made in the proposed GPR model. Covariance function design and the similarity measurement of input variables are modified so as to improve the SOH estimate accuracy and adapt to the case of multidimensional input. Several aging data from NASA data repository are used for demonstrating the estimation effect by the proposed method. Results show that the proposed method has high SOH estimation accuracy. Besides, a battery with dynamic discharging profile is used to verify the robustness and reliability of this method.

A Protocol for Electrochemical Evaluations and State of Charge Diagnostics of a Symmetric Organic Redox Flow Battery.

Science.gov (United States)

Duan, Wentao; Vemuri, Rama S; Hu, Dehong; Yang, Zheng; Wei, Xiaoliang

2017-02-13

Redox flow batteries have been considered as one of the most promising stationary energy storage solutions for improving the reliability of the power grid and deployment of renewable energy technologies. Among the many flow battery chemistries, non-aqueous flow batteries have the potential to achieve high energy density because of the broad voltage windows of non-aqueous electrolytes. However, significant technical hurdles exist currently limiting non-aqueous flow batteries to demonstrate their full potential, such as low redox concentrations, low operating currents, under-explored battery status monitoring, etc. In an attempt to address these limitations, we recently reported a non-aqueous flow battery based on a highly soluble, redox-active organic nitronyl nitroxide radical compound, 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (PTIO). This redox material exhibits an ambipolar electrochemical property, and therefore can serve as both anolyte and catholyte redox materials to form a symmetric flow battery chemistry. Moreover, we demonstrated that Fourier transform infrared (FTIR) spectroscopy could measure the PTIO concentrations during the PTIO flow battery cycling and offer reasonably accurate detection of the battery state of charge (SOC), as cross-validated by electron spin resonance (ESR) measurements. Herein we present a video protocol for the electrochemical evaluation and SOC diagnosis of the PTIO symmetric flow battery. With a detailed description, we experimentally demonstrated the route to achieve such purposes. This protocol aims to spark more interests and insights on the safety and reliability in the field of non-aqueous redox flow batteries.

A multi-timescale estimator for battery state of charge and capacity dual estimation based on an online identified model

International Nuclear Information System (INIS)

Wei, Zhongbao; Zhao, Jiyun; Ji, Dongxu; Tseng, King Jet

2017-01-01

Highlights: •SOC and capacity are dually estimated with online adapted battery model. •Model identification and state dual estimate are fully decoupled. •Multiple timescales are used to improve estimation accuracy and stability. •The proposed method is verified with lab-scale experiments. •The proposed method is applicable to different battery chemistries. -- Abstract: Reliable online estimation of state of charge (SOC) and capacity is critically important for the battery management system (BMS). This paper presents a multi-timescale method for dual estimation of SOC and capacity with an online identified battery model. The model parameter estimator and the dual estimator are fully decoupled and executed with different timescales to improve the model accuracy and stability. Specifically, the model parameters are online adapted with the vector-type recursive least squares (VRLS) to address the different variation rates of them. Based on the online adapted battery model, the Kalman filter (KF)-based SOC estimator and RLS-based capacity estimator are formulated and integrated in the form of dual estimation. Experimental results suggest that the proposed method estimates the model parameters, SOC, and capacity in real time with fast convergence and high accuracy. Experiments on both lithium-ion battery and vanadium redox flow battery (VRB) verify the generality of the proposed method on multiple battery chemistries. The proposed method is also compared with other existing methods on the computational cost to reveal its superiority for practical application.

A Real-Time Simulink Interfaced Fast-Charging Methodology of Lithium-Ion Batteries under Temperature Feedback with Fuzzy Logic Control

Directory of Open Access Journals (Sweden)

Muhammad Umair Ali

2018-05-01

Full Text Available The lithium-ion battery has high energy and power density, long life cycle, low toxicity, low discharge rate, more reliability, and better efficiency compared to other batteries. On the other hand, the issue of a reduction in charging time of the lithium-ion battery is still a bottleneck for the commercialization of electric vehicles (EVs. Therefore, an approach to charge lithium-ion batteries at a faster rate is needed. This paper proposes an efficient, real-time, fast-charging methodology of lithium-ion batteries. Fuzzy logic was adopted to drive the charging current trajectory. A temperature control unit was also implemented to evade the effects of fast charging on the aging mechanism. The proposed method of charging also protects the battery from overvoltage and overheating. Extensive testing and comprehensive analysis were conducted to examine the proposed charging technique. The results show that the proposed charging strategy favors a full battery recharging in 9.76% less time than the conventional constant-current–constant-voltage (CC/CV method. The strategy charges the battery at a 99.26% state of charge (SOC without significant degradation. The entire scheme was implemented in real time, using Arduino interfaced with MATLABTM Simulink. This decrease in charging time assists in the fast charging of cell phones and notebooks and in the large-scale deployment of EVs.

Characterization of 109 Ah Ni-MH batteries charging with hydrogen sensing termination

Science.gov (United States)

Viera, J. C.; González, M.; Liaw, B. Y.; Ferrero, F. J.; Álvarez, J. C.; Campo, J. C.; Blanco, C.

The use of Ni-MH batteries for traction applications in electric and hybrid vehicles is increasingly attractive and reliable. Besides the energy and power handling, and the cost issues, high tolerance to abuse is an important aspect of the Ni-MH technology. Thus, the ability to reduce charging time and to absorb regenerative breaking is highly desirable in these traction applications. This requires an accurate control of the charge termination. To facilitate an easy and reliable charging control and to avoid battery premature failure or ageing it is very important to know the behavior of the battery under a range of charging conditions. In this paper, we described the performance of high capacity commercial Ni-MH traction batteries (12 V, 109 Ah modules) when subjected to different charging rates (0.1, 0.2, 0.5, and 1.0 C) from 100% depth of discharge (DOD). Changes in battery voltage and temperature during charging were monitored, with a particular emphasis on the detection of the presence of hydrogen near the battery. This unique hydrogen detection outside the battery was used as the method for the end-of-charge termination to prevent overcharging of the battery. Relevant parameters, such as charge acceptance, energy efficiency, and charging time, were analyzed for comparison.

Analysis of the Deposit Layer from Electrolyte Side Reaction on the Anode of the Pouch Type Lithium Ion Polymer Batteries: The Effect of State of Charge and Charge Rate

International Nuclear Information System (INIS)

Agubra, Victor A.; Fergus, Jeffrey W.; Fu, Rujian; Choe, Song-yul

2014-01-01

Highlights: • Raising the battery cycling potential increased the rate of side reaction. • Growth of deposit layer thickness at the electrode/electrolyte interface at high SOC. • A significant amount of lithium was consumed in forming the deposit layer. • Some of the lithium were “trapped” in the graphite after the discharge cycle. - Abstract: The formation of the solid electrolyte interface (SEI) layer on the surface of the anode electrode of a lithium ion battery prevents further electrolyte decomposition reaction. However, at certain battery operating conditions, the SEI breakdown leading to more electrolyte decomposition reactions that form several species on the anode electrode surface. This paper focuses on the effect of battery potential and charge rate on the decomposition side reaction on the anode electrode of a lithium ion polymer battery, as a result of the breakdown of the SEI layer. The results from this study indicate that raising the state of charge (SOC) increases the rate of the electrolyte decomposition side reaction that resulted in formation of a thick deposit layer at the electrolyte/electrolyte interface. This deposit layer contains lithium that can no longer participate in the reversible electrochemical reaction. In addition, at high cycling potential and charge rates the amount of lithium in the graphite after complete cell discharge increased due to the entrapment of lithium in the graphite. The amount of irreversible capacity loss for the batteries cycled at high potential and current correlates with the amount of trapped lithium in the graphite and the growth of the deposit layer thickness at the electrode/electrolyte interface

Impact of Fast Charging on Life of EV Batteries

Energy Technology Data Exchange (ETDEWEB)

Neubauer, Jeremy; Wood, Eric; Burton, Evan; Smith, Kandler; Pesaran, Ahmad A.

2015-05-03

Utilization of public charging infrastructure is heavily dependent on user-specific travel behavior. The availability of fast chargers can positively affect the utility of battery electric vehicles, even given infrequent use. Estimated utilization rates do not appear frequent enough to significantly impact battery life. Battery thermal management systems are critical in mitigating dangerous thermal conditions on long distance tours with multiple fast charge events.

Methods and systems for thermodynamic evaluation of battery state of health

Science.gov (United States)

Yazami, Rachid; McMenamin, Joseph; Reynier, Yvan; Fultz, Brent T

2014-12-02

Described are systems and methods for accurately characterizing thermodynamic and materials properties of electrodes and battery systems and for characterizing the state of health of electrodes and battery systems. Measurement of physical attributes of electrodes and batteries corresponding to thermodynamically stabilized electrode conditions permit determination of thermodynamic parameters, including state functions such as the Gibbs free energy, enthalpy and entropy of electrode/electrochemical cell reactions, that enable prediction of important performance attributes of electrode materials and battery systems, such as energy, power density, current rate, cycle life and state of health. Also provided are systems and methods for charging a battery according to its state of health.

A novel multi-model probability battery state of charge estimation approach for electric vehicles using H-infinity algorithm

International Nuclear Information System (INIS)

Lin, Cheng; Mu, Hao; Xiong, Rui; Shen, Weixiang

2016-01-01

Highlights: • A novel multi-model probability battery SOC fusion estimation approach was proposed. • The linear matrix inequality-based H∞ technique is employed to estimate the SOC. • The Bayes theorem has been employed to realize the optimal weight for the fusion. • The robustness of the proposed approach is verified by different batteries. • The results show that the proposed method can promote global estimation accuracy. - Abstract: Due to the strong nonlinearity and complex time-variant property of batteries, the existing state of charge (SOC) estimation approaches based on a single equivalent circuit model (ECM) cannot provide the accurate SOC for the entire discharging period. This paper aims to present a novel SOC estimation approach based on a multiple ECMs fusion method for improving the practical application performance. In the proposed approach, three battery ECMs, namely the Thevenin model, the double polarization model and the 3rd order RC model, are selected to describe the dynamic voltage of lithium-ion batteries and the genetic algorithm is then used to determine the model parameters. The linear matrix inequality-based H-infinity technique is employed to estimate the SOC from the three models and the Bayes theorem-based probability method is employed to determine the optimal weights for synthesizing the SOCs estimated from the three models. Two types of lithium-ion batteries are used to verify the feasibility and robustness of the proposed approach. The results indicate that the proposed approach can improve the accuracy and reliability of the SOC estimation against uncertain battery materials and inaccurate initial states.

Battery charging stations

Energy Technology Data Exchange (ETDEWEB)

Bergey, M.

1997-12-01

This paper discusses the concept of battery charging stations (BCSs), designed to service rural owners of battery power sources. Many such power sources now are transported to urban areas for recharging. A BCS provides the opportunity to locate these facilities closer to the user, is often powered by renewable sources, or hybrid systems, takes advantage of economies of scale, and has the potential to provide lower cost of service, better service, and better cost recovery than other rural electrification programs. Typical systems discussed can service 200 to 1200 people, and consist of stations powered by photovoltaics, wind/PV, wind/diesel, or diesel only. Examples of installed systems are presented, followed by cost figures, economic analysis, and typical system design and performance numbers.

29 CFR 1917.157 - Battery charging and changing.

Science.gov (United States)

2010-07-01

... jumper battery is connected to a battery in a vehicle, the ground lead shall connect to ground away from...) Metallic objects shall not be placed on uncovered batteries. (m) When batteries are being charged, the vent caps shall be in place. (n) Chargers shall be turned off when leads are being connected or disconnected...

State-of-Charge Estimation and Active Cell Pack Balancing Design of Lithium Battery Power System for Smart Electric Vehicle

Directory of Open Access Journals (Sweden)

Z. C. Gao

2017-01-01

Full Text Available This paper presents an integrated state-of-charge (SOC estimation model and active cell balancing of a 12-cell lithium iron phosphate (LiFePO4 battery power system. The strong tracking cubature extended Kalman filter (STCEKF gave an accurate SOC prediction compared to other Kalman-based filter algorithms. The proposed groupwise balancing of the multiple SOC exhibited a higher balancing speed and lower balancing loss than other cell balancing designs. The experimental results demonstrated the robustness and performance of the battery when subjected to current load profile of an electric vehicle under varying ambient temperature.

Battery control system for hybrid vehicle and method for controlling a hybrid vehicle battery

Science.gov (United States)

Bockelmann, Thomas R [Battle Creek, MI; Hope, Mark E [Marshall, MI; Zou, Zhanjiang [Battle Creek, MI; Kang, Xiaosong [Battle Creek, MI

2009-02-10

A battery control system for hybrid vehicle includes a hybrid powertrain battery, a vehicle accessory battery, and a prime mover driven generator adapted to charge the vehicle accessory battery. A detecting arrangement is configured to monitor the vehicle accessory battery's state of charge. A controller is configured to activate the prime mover to drive the generator and recharge the vehicle accessory battery in response to the vehicle accessory battery's state of charge falling below a first predetermined level, or transfer electrical power from the hybrid powertrain battery to the vehicle accessory battery in response to the vehicle accessory battery's state of charge falling below a second predetermined level. The invention further includes a method for controlling a hybrid vehicle powertrain system.

Life cycle assessment of five batteries for electric vehicles under different charging regimes

Energy Technology Data Exchange (ETDEWEB)

Rantik, M. [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Transportation and Logistics

1999-12-01

Life Cycle Assessment (LCA) methodology is used in this study to assess the environmental impact of five candidate batteries for electric vehicles under different conditions of charging. The entire lifetime of a passenger electric vehicle is considered as the basis for all batteries. Five different battery systems are considered. The four of them are electrically recharged - Lead-Acid, Nickel-Cadmium, Nickel-Metal hydride and Sodium-Nickel chloride whereas one system comprises batteries that are recharged mechanically (Zinc-Air). One specific battery from these five systems is selected. The results are representative of these particular batteries and not of the battery systems to which they belong. The study includes three scenarios, the basic scenario and two fast charging scenarios. The difference between the scenarios is in the phase of the battery's use and involves the charging regimes. Consequently, the other stages of the battery's life are identical in all three scenarios. The basic scenario implies normal overnight charging is used during the entire lifetime of an electric vehicle. In the first fast charging scenario, fast charging is combined with normal charging. The second fast charging scenario involves the exclusive use of fast charging. In both fast charging scenarios the user's behaviour is considered. In this study, it is believed that it is the violation of fast charging rules, set by the battery manufacturer rather than the fast charging technique, that will be critical for the cycle life of the battery. Due to low energy efficiency of the batteries and losses in the charging procedure, the use of energy for operating the electric vehicle seems to be a major contributor to the total environmental impact of the system. Significant resource constraints may prevent mass production of certain batteries or lead to increased prices of others. Use of fast charging increases the number of batteries used during the lifetime of the electric

Charging system and method for multicell storage batteries

Science.gov (United States)

Cox, Jay A.

1978-01-01

A battery-charging system includes a first charging circuit connected in series with a plurality of battery cells for controlled current charging. A second charging circuit applies a controlled voltage across each individual cell for equalization of the cells to the fully charged condition. This controlled voltage is determined at a level above the fully charged open-circuit voltage but at a sufficiently low level to prevent corrosion of cell components by electrochemical reaction. In this second circuit for cell equalization, a transformer primary receives closely regulated, square-wave voltage which is coupled to a plurality of equal secondary coil windings. Each secondary winding is connected in parallel to each cell of a series-connected pair of cells through half-wave rectifiers and a shared, intermediate conductor.

Active-charging based powertrain control in series hybrid electric vehicles for efficiency improvement and battery lifetime extension

Science.gov (United States)

Zhang, Xi; Mi, Chris Chunting; Yin, Chengliang

2014-01-01

This paper presents a powertrain control strategy for a series hybrid electric vehicle (SHEV) based on the integrated design of an active charging scenario and fixed-boundary-layer sliding mode controllers (FBLSMCs). An optimized charging curve for the battery is predetermined rather than subject to engine output and vehicle power demand, which is a total inverse of normal SHEV powertrain control process. This is aimed to remove surge and high-frequency charge current, keep the battery staying in a high state-of-charge (SOC) region and avoid persistently-high charge power, which are positive factors to battery lifetime extension. Then two robust chattering-free FBLSMCs are designed to locate the engine operation in the optimal efficiency area. One is in charge of engine speed control, and the other is for engine/generator torque control. Consequently, not only fuel economy is improved but also battery life expectancy could be extended. Finally, simulation and experimental results confirm the validity and application feasibility of the proposed strategy.

A Protocol for Electrochemical Evaluations and State of Charge Diagnostics of a Symmetric Organic Redox Flow Battery

Energy Technology Data Exchange (ETDEWEB)

Duan, Wentao; Vemuri, Rama S.; Hu, Dehong; Yang, Zheng; Wei, Xiaoliang

2017-01-01

Redox flow batteries have been considered as one of the most promising stationary energy storage solutions for improving the reliability of the power grid and deployment of renewable energy technologies. Among the many flow battery chemistries, nonaqueous flow batteries have the potential to achieve high energy density because of the broad voltage windows of nonaqueous electrolytes. However, significant technical hurdles exist currently limiting nonaqueous flow batteries to demonstrate their full potential, such as low redox concentrations, low operating currents, under-explored battery status monitoring, etc. In an attempt to address these limitations, we report a nonaqueous flow battery based on a highly soluble, redox-active organic nitronyl nitroxide radical compound, 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (PTIO). This redox materials exhibits an ambipolar electrochemical property with two reversible redox pairs that are moderately separated by a voltage gap of ~1.7 V. Therefore, PTIO can serve as both anolyte and catholyte redox materials to form a symmetric flow battery chemistry, which affords the advantages such as high effective redox concentrations and low irreversible redox material crossover. The PTIO flow battery shows decent electrochemical cyclability under cyclic voltammetry and flow cell conditions; an improved redox concentration of 0.5 M PTIO and operational current density of 20 mA cm-2 were achieved in flow cell tests. Moreover, we show that Fourier transform infrared (FTIR) spectroscopy could measure the PTIO concentrations during the PTIO flow battery cycling and offer reasonably accurate detection of the battery state of charge (SOC) as cross-validated by electron spin resonance measurements. This study suggests FTIR can be used as a reliable online SOC sensor to monitor flow battery status and ensure battery operations stringently in a safe SOC range.

Electric and hybrid vehicles charge efficiency tests of ESB EV-106 lead acid batteries

Science.gov (United States)

Rowlette, J. J.

1981-01-01

Charge efficiencies were determined by measurements made under widely differing conditions of temperature, charge procedure, and battery age. The measurements were used to optimize charge procedures and to evaluate the concept of a modified, coulometric state of charge indicator. Charge efficiency determinations were made by measuring gassing rates and oxygen fractions. A novel, positive displacement gas flow meter which proved to be both simple and highly accurate is described and illustrated.

Multi-temperature state-dependent equivalent circuit discharge model for lithium-sulfur batteries

DEFF Research Database (Denmark)

Propp, Karsten; Marinescu, Monica; Auger, Daniel J.

2016-01-01

Lithium-sulfur (Li-S) batteries are described extensively in the literature, but existing computational models aimed at scientific understanding are too complex for use in applications such as battery management. Computationally simple models are vital for exploitation. This paper proposes a non......-linear state-of-charge dependent Li-S equivalent circuit network (ECN) model for a Li-S cell under discharge. Li-S batteries are fundamentally different to Li-ion batteries, and require chemistry-specific models. A new Li-S model is obtained using a ‘behavioural’ interpretation of the ECN model; as Li...... pulse profile at four temperatures from 10 °C to 50 °C, giving linearized ECN parameters for a range of states-of-charge, currents and temperatures. These are used to create a nonlinear polynomial-based battery model suitable for use in a battery management system. When the model is used to predict...

High Reversibility of “Soft” Electrode Materials in All-Solid-State Batteries

Energy Technology Data Exchange (ETDEWEB)

Sakuda, Atsushi, E-mail: a.sakuda@aist.go.jp; Takeuchi, Tomonari, E-mail: a.sakuda@aist.go.jp; Shikano, Masahiro; Sakaebe, Hikari; Kobayashi, Hironori [Department of Energy and Environment, Research Institute for Electrochemical Energy, National Institute of Advanced Industrial Science and Technology (AIST), Ikeda (Japan)

2016-05-10

All-solid-state batteries using inorganic solid electrolytes (SEs) are considered to be ideal batteries for electric vehicles and plug-in hybrid electric vehicles because they are potentially safer than conventional lithium-ion batteries (LIBs). In addition, all-solid-state batteries are expected to have long battery life owing to the inhibition of chemical side reactions because only lithium ions move through the typically used inorganic SEs. The development of high-energy density (more than 300 Wh kg{sup −1}) secondary batteries has been eagerly anticipated for years. The application of high-capacity electrode active materials is essential for fabricating such batteries. Recently, we proposed metal polysulfides as new electrode materials. These materials show higher conductivity and density than sulfur, which is advantageous for fabricating batteries with relatively higher energy density. Lithium niobium sulfides, such as Li{sub 3}NbS{sub 4}, have relatively high density, conductivity, and rate capability among metal polysulfide materials, and batteries with these materials have capacities high enough to potentially exceed the gravimetric-energy density of conventional LIBs. Favorable solid–solid contact between the electrode and electrolyte particles is a key factor for fabricating high performance all-solid-state batteries. Conventional oxide-based positive electrode materials tend to give rise to cracks during fabrication and/or charge–discharge processes. Here, we report all-solid-state cells using lithium niobium sulfide as a positive electrode material, where favorable solid–solid contact was established by using lithium sulfide electrode materials because of their high processability. Cracks were barely observed in the electrode particles in the all-solid-state cells before or after charging and discharging with a high capacity of approximately 400 mAh g{sup −1} suggesting that the lithium niobium sulfide electrode charged and discharged without

High Reversibility of “Soft” Electrode Materials in All-Solid-State Batteries

International Nuclear Information System (INIS)

Sakuda, Atsushi; Takeuchi, Tomonari; Shikano, Masahiro; Sakaebe, Hikari; Kobayashi, Hironori

2016-01-01

All-solid-state batteries using inorganic solid electrolytes (SEs) are considered to be ideal batteries for electric vehicles and plug-in hybrid electric vehicles because they are potentially safer than conventional lithium-ion batteries (LIBs). In addition, all-solid-state batteries are expected to have long battery life owing to the inhibition of chemical side reactions because only lithium ions move through the typically used inorganic SEs. The development of high-energy density (more than 300 Wh kg −1 ) secondary batteries has been eagerly anticipated for years. The application of high-capacity electrode active materials is essential for fabricating such batteries. Recently, we proposed metal polysulfides as new electrode materials. These materials show higher conductivity and density than sulfur, which is advantageous for fabricating batteries with relatively higher energy density. Lithium niobium sulfides, such as Li 3 NbS 4 , have relatively high density, conductivity, and rate capability among metal polysulfide materials, and batteries with these materials have capacities high enough to potentially exceed the gravimetric-energy density of conventional LIBs. Favorable solid–solid contact between the electrode and electrolyte particles is a key factor for fabricating high performance all-solid-state batteries. Conventional oxide-based positive electrode materials tend to give rise to cracks during fabrication and/or charge–discharge processes. Here, we report all-solid-state cells using lithium niobium sulfide as a positive electrode material, where favorable solid–solid contact was established by using lithium sulfide electrode materials because of their high processability. Cracks were barely observed in the electrode particles in the all-solid-state cells before or after charging and discharging with a high capacity of approximately 400 mAh g −1 suggesting that the lithium niobium sulfide electrode charged and discharged without experiencing

Design and Experiment of Nonlinear Observer with Adaptive Gains for Battery State of Charge Estimation

Directory of Open Access Journals (Sweden)

Linhui Zhao

2017-12-01

Full Text Available State of charge (SOC is an important evaluation index for lithium-ion batteries (LIBs in electric vehicles (EVs. This paper proposes a nonlinear observer with a new adaptive gain structure for SOC estimation based on a second-order RC model. It is able to dynamically adjust the gains and obtain a better balance between convergence speed and estimation accuracy with less computational time. A sufficient condition is derived to guarantee the uniform asymptotic stability of the observer, and its robustness with respect to disturbances and uncertainties is analyzed with the help of input-to-state stability (ISS theory. A selection guide of the observer gains in practical application is presented. The estimation accuracy and convergence rate of the observer are evaluated and compared with those of extended Kalman filter (EKF based on multi-temperature datasets from two different types of LIB cells. The robustness against different disturbances and uncertainties that may appear in a real vehicle is validated and discussed in detail. The experimental results show that the proposed observer is capable of achieving better performance with less computational time in comparison to EKF for different types of LIB cells under various working conditions. The observer is also capable of estimating SOC accurately for real life conditions according to the validation results of datasets from a battery management system (BMS in an EV battery pack. Furthermore, the observer is simple enough, and is suitable for implementation on embedded hardware for LIB cells of EVs.

A method for state of energy estimation of lithium-ion batteries based on neural network model

International Nuclear Information System (INIS)

Dong, Guangzhong; Zhang, Xu; Zhang, Chenbin; Chen, Zonghai

2015-01-01

The state-of-energy is an important evaluation index for energy optimization and management of power battery systems in electric vehicles. Unlike the state-of-charge which represents the residual energy of the battery in traditional applications, state-of-energy is integral result of battery power, which is the product of current and terminal voltage. On the other hand, like state-of-charge, the state-of-energy has an effect on terminal voltage. Therefore, it is hard to solve the nonlinear problems between state-of-energy and terminal voltage, which will complicate the estimation of a battery's state-of-energy. To address this issue, a method based on wavelet-neural-network-based battery model and particle filter estimator is presented for the state-of-energy estimation. The wavelet-neural-network based battery model is used to simulate the entire dynamic electrical characteristics of batteries. The temperature and discharge rate are also taken into account to improve model accuracy. Besides, in order to suppress the measurement noises of current and voltage, a particle filter estimator is applied to estimate cell state-of-energy. Experimental results on LiFePO_4 batteries indicate that the wavelet-neural-network based battery model simulates battery dynamics robustly with high accuracy and the estimation value based on the particle filter estimator converges to the real state-of-energy within an error of ±4%. - Highlights: • State-of-charge is replaced by state-of-energy to determine cells residual energy. • The battery state-space model is established based on a neural network. • Temperature and current influence are considered to improve the model accuracy. • The particle filter is used for state-of-energy estimation to improve accuracy. • The robustness of new method is validated under dynamic experimental conditions.

Charging a Li-O₂ battery using a redox mediator.

Science.gov (United States)

Chen, Yuhui; Freunberger, Stefan A; Peng, Zhangquan; Fontaine, Olivier; Bruce, Peter G

2013-06-01

The non-aqueous Li-air (O2) battery is receiving intense interest because its theoretical specific energy exceeds that of Li-ion batteries. Recharging the Li-O2 battery depends on oxidizing solid lithium peroxide (Li2O2), which is formed on discharge within the porous cathode. However, transporting charge between Li2O2 particles and the solid electrode surface is at best very difficult and leads to voltage polarization on charging, even at modest rates. This is a significant problem facing the non-aqueous Li-O2 battery. Here we show that incorporation of a redox mediator, tetrathiafulvalene (TTF), enables recharging at rates that are impossible for the cell in the absence of the mediator. On charging, TTF is oxidized to TTF(+) at the cathode surface; TTF(+) in turn oxidizes the solid Li2O2, which results in the regeneration of TTF. The mediator acts as an electron-hole transfer agent that permits efficient oxidation of solid Li2O2. The cell with the mediator demonstrated 100 charge/discharge cycles.

Battery control system for hybrid vehicle and method for controlling a hybrid vehicle battery

Science.gov (United States)

Bockelmann, Thomas R [Battle Creek, MI; Beaty, Kevin D [Kalamazoo, MI; Zou, Zhanijang [Battle Creek, MI; Kang, Xiaosong [Battle Creek, MI

2009-07-21

A battery control system for controlling a state of charge of a hybrid vehicle battery includes a detecting arrangement for determining a vehicle operating state or an intended vehicle operating state and a controller for setting a target state of charge level of the battery based on the vehicle operating state or the intended vehicle operating state. The controller is operable to set a target state of charge level at a first level during a mobile vehicle operating state and at a second level during a stationary vehicle operating state or in anticipation of the vehicle operating in the stationary vehicle operating state. The invention further includes a method for controlling a state of charge of a hybrid vehicle battery.

Co-estimation of state-of-charge, capacity and resistance for lithium-ion batteries based on a high-fidelity electrochemical model

International Nuclear Information System (INIS)

Zheng, Linfeng; Zhang, Lei; Zhu, Jianguo; Wang, Guoxiu; Jiang, Jiuchun

2016-01-01

Highlights: • The numerical solution for an electrochemical model is presented. • Trinal PI observers are used to concurrently estimate SOC, capacity and resistance. • An iteration-approaching method is incorporated to enhance estimation performance. • The robustness against aging and temperature variations is experimentally verified. - Abstract: Lithium-ion batteries have been widely used as enabling energy storage in many industrial fields. Accurate modeling and state estimation play fundamental roles in ensuring safe, reliable and efficient operation of lithium-ion battery systems. A physics-based electrochemical model (EM) is highly desirable for its inherent ability to push batteries to operate at their physical limits. For state-of-charge (SOC) estimation, the continuous capacity fade and resistance deterioration are more prone to erroneous estimation results. In this paper, trinal proportional-integral (PI) observers with a reduced physics-based EM are proposed to simultaneously estimate SOC, capacity and resistance for lithium-ion batteries. Firstly, a numerical solution for the employed model is derived. PI observers are then developed to realize the co-estimation of battery SOC, capacity and resistance. The moving-window ampere-hour counting technique and the iteration-approaching method are also incorporated for the estimation accuracy improvement. The robustness of the proposed approach against erroneous initial values, different battery cell aging levels and ambient temperatures is systematically evaluated, and the experimental results verify the effectiveness of the proposed method.

State of Charge and State of Health Estimation of AGM VRLA Batteries by Employing a Dual Extended Kalman Filter and an ARX Model for Online Parameter Estimation

Directory of Open Access Journals (Sweden)

Ngoc-Tham Tran

2017-01-01

Full Text Available State of charge (SOC and state of health (SOH are key issues for the application of batteries, especially the absorbent glass mat valve regulated lead-acid (AGM VRLA type batteries used in the idle stop start systems (ISSs that are popularly integrated into conventional engine-based vehicles. This is due to the fact that SOC and SOH estimation accuracy is crucial for optimizing battery energy utilization, ensuring safety and extending battery life cycles. The dual extended Kalman filter (DEKF, which provides an elegant and powerful solution, is widely applied in SOC and SOH estimation based on a battery parameter model. However, the battery parameters are strongly dependent on operation conditions such as the SOC, current rate and temperature. In addition, battery parameters change significantly over the life cycle of a battery. As a result, many experimental pretests investigating the effects of the internal and external conditions of a battery on its parameters are required, since the accuracy of state estimation depends on the quality of the information regarding battery parameter changes. In this paper, a novel method for SOC and SOH estimation that combines a DEKF algorithm, which considers hysteresis and diffusion effects, and an auto regressive exogenous (ARX model for online parameters estimation is proposed. The DEKF provides precise information concerning the battery open circuit voltage (OCV to the ARX model. Meanwhile, the ARX model continues monitoring parameter variations and supplies information on them to the DEKF. In this way, the estimation accuracy can be maintained despite the changing parameters of a battery. Moreover, online parameter estimation from the ARX model can save the time and effort used for parameter pretests. The validation of the proposed algorithm is given by simulation and experimental results.

State of charge estimation of lithium-ion batteries based on an improved parameter identification method

International Nuclear Information System (INIS)

Xia, Bizhong; Chen, Chaoren; Tian, Yong; Wang, Mingwang; Sun, Wei; Xu, Zhihui

2015-01-01

The SOC (state of charge) is the most important index of the battery management systems. However, it cannot be measured directly with sensors and must be estimated with mathematical techniques. An accurate battery model is crucial to exactly estimate the SOC. In order to improve the model accuracy, this paper presents an improved parameter identification method. Firstly, the concept of polarization depth is proposed based on the analysis of polarization characteristics of the lithium-ion batteries. Then, the nonlinear least square technique is applied to determine the model parameters according to data collected from pulsed discharge experiments. The results show that the proposed method can reduce the model error as compared with the conventional approach. Furthermore, a nonlinear observer presented in the previous work is utilized to verify the validity of the proposed parameter identification method in SOC estimation. Finally, experiments with different levels of discharge current are carried out to investigate the influence of polarization depth on SOC estimation. Experimental results show that the proposed method can improve the SOC estimation accuracy as compared with the conventional approach, especially under the conditions of large discharge current. - Highlights: • The polarization characteristics of lithium-ion batteries are analyzed. • The concept of polarization depth is proposed to improve model accuracy. • A nonlinear least square technique is applied to determine the model parameters. • A nonlinear observer is used as the SOC estimation algorithm. • The validity of the proposed method is verified by experimental results.

State of health assessment for lithium batteries based on voltage–time relaxation measure

International Nuclear Information System (INIS)

Baghdadi, Issam; Briat, Olivier; Gyan, Philippe; Vinassa, Jean Michel

2016-01-01

Highlights: • Calendar aging under different storage conditions for three different battery technologies studied. • Two scenarios of aging under power cycling at two different temperatures investigated for one battery technology. • Relaxation profile of battery voltage just after full charge is highly correlated to aging. • Linear dependence between just after charge open circuit voltage and remaining capacity demonstrated. • No computational method and direct prediction of battery state of health or remaining capacity. - Abstract: The performance of lithium batteries degrades over time. The degradation rate strongly depends on stress conditions during use and even at rest. Thus, accurate and rapid diagnosis of battery state of health (SOH) is necessary for electric vehicle manufacturers to manage their vehicle fleets and warranties. This paper demonstrates a simple method for assessing SOH related to battery energy capability (SOH E ). The presented method is based on the monitoring of U relax over aging. U relax is the open-circuit voltage of the battery measured after full charging and 30 min of rest. A linear dependence between U relax and remaining capacity is noted. This correlation is demonstrated for three different commercial battery technologies (different chemistries) aged under different calendar and power cycling aging conditions. It was determined that the difference between two U relax voltages measured at two different aging states is proportional to SOH E decay. The mean error of the linear model is less than 2% for certain cases. This method could also be a highly useful and rapid tool for a complete battery pack diagnosis.

Non-Faradaic Li ⁺ Migration and Chemical Coordination across Solid-State Battery Interfaces

Energy Technology Data Exchange (ETDEWEB)

Gittleson, Forrest S. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); El Gabaly, Farid [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

2017-10-17

Efficient and reversible charge transfer is essential to realizing high-performance solid-state batteries. Efforts to enhance charge transfer at critical electrode–electrolyte interfaces have proven successful, yet interfacial chemistry and its impact on cell function remains poorly understood. Using X-ray photoelectron spectroscopy combined with electrochemical techniques, we elucidate chemical coordination near the LiCoO₂–LIPON interface, providing experimental validation of space-charge separation. Space-charge layers, defined by local enrichment and depletion of charges, have previously been theorized and modeled, but the unique chemistry of solid-state battery interfaces is now revealed. Here we highlight the non-Faradaic migration of Li+ ions from the electrode to the electrolyte, which reduces reversible cathodic capacity by ~15%. Inserting a thin, ion-conducting LiNbO₃ interlayer between the electrode and electrolyte, however, can reduce space-charge separation, mitigate the loss of Li+ from LiCoO₂, and return cathodic capacity to its theoretical value. This work illustrates the importance of interfacial chemistry in understanding and improving solid-state batteries.

A Real-Time Joint Estimator for Model Parameters and State of Charge of Lithium-Ion Batteries in Electric Vehicles

Directory of Open Access Journals (Sweden)

Jianping Gao

2015-08-01

Full Text Available Accurate state of charge (SoC estimation of batteries plays an important role in promoting the commercialization of electric vehicles. The main work to be done in accurately determining battery SoC can be summarized in three parts. (1 In view of the model-based SoC estimation flow diagram, the n-order resistance-capacitance (RC battery model is proposed and expected to accurately simulate the battery’s major time-variable, nonlinear characteristics. Then, the mathematical equations for model parameter identification and SoC estimation of this model are constructed. (2 The Akaike information criterion is used to determine an optimal tradeoff between battery model complexity and prediction precision for the n-order RC battery model. Results from a comparative analysis show that the first-order RC battery model is thought to be the best based on the Akaike information criterion (AIC values. (3 The real-time joint estimator for the model parameter and SoC is constructed, and the application based on two battery types indicates that the proposed SoC estimator is a closed-loop identification system where the model parameter identification and SoC estimation are corrected mutually, adaptively and simultaneously according to the observer values. The maximum SoC estimation error is less than 1% for both battery types, even against the inaccurate initial SoC.

Features of the low-power charge controller of lead-acid current sources charged by solar batteries

International Nuclear Information System (INIS)

Tukfatullin, O.F.; Yuldoshev, I.A.; Solieva, N.A.

2008-01-01

Influence of different factors on exploitations characteristics of solar photoelectric plant is investigated by field-performance data. A construction of charge controller of the lead-acid accumulator battery charging by means of solar battery is analyzed taking into account these factors. (authors)

FY14 Milestone: Simulated Impacts of Life-Like Fast Charging on BEV Batteries

Energy Technology Data Exchange (ETDEWEB)

Neubauer, Jeremy [National Renewable Energy Lab. (NREL), Golden, CO (United States). Transportation and Hydrogen Systems Center; Wood, Eric [National Renewable Energy Lab. (NREL), Golden, CO (United States). Transportation and Hydrogen Systems Center; Burton, Evan [National Renewable Energy Lab. (NREL), Golden, CO (United States). Transportation and Hydrogen Systems Center; Smith, Kandler [National Renewable Energy Lab. (NREL), Golden, CO (United States). Transportation and Hydrogen Systems Center; Pesaran, Ahmad [National Renewable Energy Lab. (NREL), Golden, CO (United States). Transportation and Hydrogen Systems Center

2014-09-01

Fast charging is attractive to battery electric vehicle (BEV) drivers for its ability to enable long-distance travel and quickly recharge depleted batteries on short notice. However, such aggressive charging and the sustained vehicle operation that results could lead to excessive battery temperatures and degradation. Properly assessing the consequences of fast charging requires accounting for disparate cycling, heating, and aging of individual cells in large BEV packs when subjected to realistic travel patterns, usage of fast chargers, and climates over long durations (i.e., years). The U.S. Department of Energy's Vehicle Technologies Office has supported NREL's development of BLAST-V 'the Battery Lifetime Analysis and Simulation Tool for Vehicles' to create a tool capable of accounting for all of these factors. The authors present on the findings of applying this tool to realistic fast charge scenarios. The effects of different travel patterns, climates, battery sizes, battery thermal management systems, and other factors on battery performance and degradation are presented. The primary challenge for BEV batteries operated in the presence of fast charging is controlling maximum battery temperature, which can be achieved with active battery cooling systems.

A novel method for state of charge estimation of lithium-ion batteries using a nonlinear observer

Science.gov (United States)

Xia, Bizhong; Chen, Chaoren; Tian, Yong; Sun, Wei; Xu, Zhihui; Zheng, Weiwei

2014-12-01

The state of charge (SOC) is important for the safety and reliability of battery operation since it indicates the remaining capacity of a battery. However, as the internal state of each cell cannot be directly measured, the value of the SOC has to be estimated. In this paper, a novel method for SOC estimation in electric vehicles (EVs) using a nonlinear observer (NLO) is presented. One advantage of this method is that it does not need complicated matrix operations, so the computation cost can be reduced. As a key step in design of the nonlinear observer, the state-space equations based on the equivalent circuit model are derived. The Lyapunov stability theory is employed to prove the convergence of the nonlinear observer. Four experiments are carried out to evaluate the performance of the presented method. The results show that the SOC estimation error converges to 3% within 130 s while the initial SOC error reaches 20%, and does not exceed 4.5% while the measurement suffers both 2.5% voltage noise and 5% current noise. Besides, the presented method has advantages over the extended Kalman filter (EKF) and sliding mode observer (SMO) algorithms in terms of computation cost, estimation accuracy and convergence rate.

Transportation Safety of Lithium Iron Phosphate Batteries - A Feasibility Study of Storing at Very Low States of Charge.

Science.gov (United States)

Barai, Anup; Uddin, Kotub; Chevalier, Julie; Chouchelamane, Gael H; McGordon, Andrew; Low, John; Jennings, Paul

2017-07-11

In freight classification, lithium-ion batteries are classed as dangerous goods and are therefore subject to stringent regulations and guidelines for certification for safe transport. One such guideline is the requirement for batteries to be at a state of charge of 30%. Under such conditions, a significant amount of the battery's energy is stored; in the event of mismanagement, or indeed an airside incident, this energy can lead to ignition and a fire. In this work, we investigate the effect on the battery of removing 99.1% of the total stored energy. The performance of 8Ah C 6 /LiFePO 4 pouch cells were measured following periods of calendar ageing at low voltages, at and well below the manufacturer's recommended value. Battery degradation was monitored using impedance spectroscopy and capacity tests; the results show that the cells stored at 2.3 V exhibited no change in cell capacity after 90 days; resistance rise was negligible. Energy-dispersive X-ray spectroscopy results indicate that there was no significant copper dissolution. To test the safety of the batteries at low voltages, external short-circuit tests were performed on the cells. While the cells discharged to 2.3 V only exhibited a surface temperature rise of 6 °C, cells at higher voltages exhibited sparks, fumes and fire.

Development of a Microcontroller-based Battery Charge Controller for an Off-grid Photovoltaic System

Science.gov (United States)

Rina, Z. S.; Amin, N. A. M.; Hashim, M. S. M.; Majid, M. S. A.; Rojan, M. A.; Zaman, I.

2017-08-01

A development of a microcontroller-based charge controller for a 12V battery has been explained in this paper. The system is designed based on a novel algorithm to couple existing solar photovoltaic (PV) charging and main grid supply charging power source. One of the main purposes of the hybrid charge controller is to supply a continuous charging power source to the battery. Furthermore, the hybrid charge controller was developed to shorten the battery charging time taken. The algorithm is programmed in an Arduino Uno R3 microcontroller that monitors the battery voltage and generates appropriate commands for the charging power source selection. The solar energy is utilized whenever the solar irradiation is high. The main grid supply will be only consumed whenever the solar irradiation is low. This system ensures continuous charging power supply and faster charging of the battery.

Solar photovoltaic charging of high voltage nickel metal hydride batteries using DC power conversion

Science.gov (United States)

Kelly, Nelson A.; Gibson, Thomas L.

There are an increasing number of vehicle choices available that utilize batteries and electric motors to reduce tailpipe emissions and increase fuel economy. The eventual production of electricity and hydrogen in a renewable fashion, such as using solar energy, can achieve the long-term vision of having no tailpipe environmental impact, as well as eliminating the dependence of the transportation sector on dwindling supplies of petroleum for its energy. In this report we will demonstrate the solar-powered charging of the high-voltage nickel-metal hydride (NiMH) battery used in the GM 2-mode hybrid system. In previous studies we have used low-voltage solar modules to produce hydrogen via the electrolysis of water and to directly charge lithium-ion battery modules. Our strategy in the present work was to boost low-voltage PV voltage to over 300 V using DC-DC converters in order to charge the high-voltage NiMH battery, and to regulate the battery charging using software to program the electronic control unit supplied with the battery pack. A protocol for high-voltage battery charging was developed, and the solar to battery charging efficiency was measured under a variety of conditions. We believe this is the first time such high-voltage batteries have been charged using solar energy in order to prove the concept of efficient, solar-powered charging for battery-electric vehicles.

Hybrid supercapacitor-battery materials for fast electrochemical charge storage

Science.gov (United States)

Vlad, A.; Singh, N.; Rolland, J.; Melinte, S.; Ajayan, P. M.; Gohy, J.-F.

2014-01-01

High energy and high power electrochemical energy storage devices rely on different fundamental working principles - bulk vs. surface ion diffusion and electron conduction. Meeting both characteristics within a single or a pair of materials has been under intense investigations yet, severely hindered by intrinsic materials limitations. Here, we provide a solution to this issue and present an approach to design high energy and high power battery electrodes by hybridizing a nitroxide-polymer redox supercapacitor (PTMA) with a Li-ion battery material (LiFePO4). The PTMA constituent dominates the hybrid battery charge process and postpones the LiFePO4 voltage rise by virtue of its ultra-fast electrochemical response and higher working potential. We detail on a unique sequential charging mechanism in the hybrid electrode: PTMA undergoes oxidation to form high-potential redox species, which subsequently relax and charge the LiFePO4 by an internal charge transfer process. A rate capability equivalent to full battery recharge in less than 5 minutes is demonstrated. As a result of hybrid's components synergy, enhanced power and energy density as well as superior cycling stability are obtained, otherwise difficult to achieve from separate constituents. PMID:24603843

Modeling all-solid-state Li-ion batteries

NARCIS (Netherlands)

Danilov, D.; Niessen, R.A.H.; Notten, P.H.L.

2011-01-01

A mathematical model for all-solid-state Li-ion batteries is presented. The model includes the charge transfer kinetics at the electrode/electrolyte interface, diffusion of lithium in the intercalation electrode, and diffusion and migration of ions in the electrolyte. The model has been applied to

Effects of battery charge acceptance and battery aging in complete vehicle energy management

NARCIS (Netherlands)

Khalik, Z.; Romijn, T.C.J.; Donkers, M.C.F.; Weiland, S.

2017-01-01

In this paper, we propose a solution to the complete vehicle energy management problem with battery charge acceptance limitations and battery aging limitations. The problem is solved using distributed optimization for a case study of a hybrid heavy-duty vehicle, equipped with a refrigerated

Comparative Study of Online Open Circuit Voltage Estimation Techniques for State of Charge Estimation of Lithium-Ion Batteries

Directory of Open Access Journals (Sweden)

Hicham Chaoui

2017-04-01

Full Text Available Online estimation techniques are extensively used to determine the parameters of various uncertain dynamic systems. In this paper, online estimation of the open-circuit voltage (OCV of lithium-ion batteries is proposed by two different adaptive filtering methods (i.e., recursive least square, RLS, and least mean square, LMS, along with an adaptive observer. The proposed techniques use the battery’s terminal voltage and current to estimate the OCV, which is correlated to the state of charge (SOC. Experimental results highlight the effectiveness of the proposed methods in online estimation at different charge/discharge conditions and temperatures. The comparative study illustrates the advantages and limitations of each online estimation method.

A method for state-of-charge estimation of Li-ion batteries based on multi-model switching strategy

International Nuclear Information System (INIS)

Wang, Yujie; Zhang, Chenbin; Chen, Zonghai

2015-01-01

Highlights: • Build a multi-model switching SOC estimate method for Li-ion batteries. • Build an improved interpretative structural modeling method for model switching. • The feedback strategy of bus delay is applied to improve the real-time performance. • The EKF method is used for SOC estimation to improve the estimated accuracy. - Abstract: The accurate state-of-charge (SOC) estimation and real-time performance are critical evaluation indexes for Li-ion battery management systems (BMS). High accuracy algorithms often take long program execution time (PET) in the resource-constrained embedded application systems, which will undoubtedly lead to the decrease of the time slots of other processes, thereby reduce the overall performance of BMS. Considering the resource optimization and the computational load balance, this paper proposes a multi-model switching SOC estimation method for Li-ion batteries. Four typical battery models are employed to build a close-loop SOC estimation system. The extended Kalman filter (EKF) method is employed to eliminate the effect of the current noise and improve the accuracy of SOC. The experiments under dynamic current conditions are conducted to verify the accuracy and real-time performance of the proposed method. The experimental results indicate that accurate estimation results and reasonable PET can be obtained by the proposed method

In situ X-ray near-edge absorption spectroscopy investigation of the state of charge of all-vanadium redox flow batteries.

Science.gov (United States)

Jia, Chuankun; Liu, Qi; Sun, Cheng-Jun; Yang, Fan; Ren, Yang; Heald, Steve M; Liu, Yadong; Li, Zhe-Fei; Lu, Wenquan; Xie, Jian

2014-10-22

Synchrotron-based in situ X-ray near-edge absorption spectroscopy (XANES) has been used to study the valence state evolution of the vanadium ion for both the catholyte and anolyte in all-vanadium redox flow batteries (VRB) under realistic cycling conditions. The results indicate that, when using the widely used charge-discharge profile during the first charge process (charging the VRB cell to 1.65 V under a constant current mode), the vanadium ion valence did not reach V(V) in the catholyte and did not reach V(II) in the anolyte. Consequently, the state of charge (SOC) for the VRB cell was only 82%, far below the desired 100% SOC. Thus, such incompletely charged mix electrolytes results in not only wasting the electrolytes but also decreasing the cell performance in the following cycles. On the basis of our study, we proposed a new charge-discharge profile (first charged at a constant current mode up to 1.65 V and then continuously charged at a constant voltage mode until the capacity was close to the theoretical value) for the first charge process that achieved 100% SOC after the initial charge process. Utilizing this new charge-discharge profile, the theoretical charge capacity and the full utilization of electrolytes has been achieved, thus having a significant impact on the cost reduction of the electrolytes in VRB.

A novel approach of battery pack state of health estimation using artificial intelligence optimization algorithm

Science.gov (United States)

Zhang, Xu; Wang, Yujie; Liu, Chang; Chen, Zonghai

2018-02-01

An accurate battery pack state of health (SOH) estimation is important to characterize the dynamic responses of battery pack and ensure the battery work with safety and reliability. However, the different performances in battery discharge/charge characteristics and working conditions in battery pack make the battery pack SOH estimation difficult. In this paper, the battery pack SOH is defined as the change of battery pack maximum energy storage. It contains all the cells' information including battery capacity, the relationship between state of charge (SOC) and open circuit voltage (OCV), and battery inconsistency. To predict the battery pack SOH, the method of particle swarm optimization-genetic algorithm is applied in battery pack model parameters identification. Based on the results, a particle filter is employed in battery SOC and OCV estimation to avoid the noise influence occurring in battery terminal voltage measurement and current drift. Moreover, a recursive least square method is used to update cells' capacity. Finally, the proposed method is verified by the profiles of New European Driving Cycle and dynamic test profiles. The experimental results indicate that the proposed method can estimate the battery states with high accuracy for actual operation. In addition, the factors affecting the change of SOH is analyzed.

Influence of different open circuit voltage tests on state of charge online estimation for lithium-ion batteries

International Nuclear Information System (INIS)

Zheng, Fangdan; Xing, Yinjiao; Jiang, Jiuchun; Sun, Bingxiang; Kim, Jonghoon; Pecht, Michael

2016-01-01

Highlights: • Two common tests for observing battery open circuit voltage performance are compared. • The temperature dependency of the OCV-SOC relationship is investigated. • Two estimators are evaluated in terms of accuracy and robustness for estimating battery SOC. • The incremental OCV test is better to predetermine the OCV-SOCs for SOC online estimation. - Abstract: Battery state of charge (SOC) estimation is a crucial function of battery management systems (BMSs), since accurate estimated SOC is critical to ensure the safety and reliability of electric vehicles. A widely used technique for SOC estimation is based on online inference of battery open circuit voltage (OCV). Low-current OCV and incremental OCV tests are two common methods to observe the OCV-SOC relationship, which is an important element of the SOC estimation technique. In this paper, two OCV tests are run at three different temperatures and based on which, two SOC estimators are compared and evaluated in terms of tracking accuracy, convergence time, and robustness for online estimating battery SOC. The temperature dependency of the OCV-SOC relationship is investigated and its influence on SOC estimation results is discussed. In addition, four dynamic tests are presented, one for estimator parameter identification and the other three for estimator performance evaluation. The comparison results show that estimator 2 (based on the incremental OCV test) has higher tracking accuracy and is more robust against varied loading conditions and different initial values of SOC than estimator 1 (based on the low-current OCV test) with regard to ambient temperature. Therefore, the incremental OCV test is recommended for predetermining the OCV-SOCs for battery SOC online estimation in BMSs.

Joint Estimation of the Electric Vehicle Power Battery State of Charge Based on the Least Squares Method and the Kalman Filter Algorithm

Directory of Open Access Journals (Sweden)

Xiangwei Guo

2016-02-01

Full Text Available An estimation of the power battery state of charge (SOC is related to the energy management, the battery cycle life and the use cost of electric vehicles. When a lithium-ion power battery is used in an electric vehicle, the SOC displays a very strong time-dependent nonlinearity under the influence of random factors, such as the working conditions and the environment. Hence, research on estimating the SOC of a power battery for an electric vehicle is of great theoretical significance and application value. In this paper, according to the dynamic response of the power battery terminal voltage during a discharging process, the second-order RC circuit is first used as the equivalent model of the power battery. Subsequently, on the basis of this model, the least squares method (LS with a forgetting factor and the adaptive unscented Kalman filter (AUKF algorithm are used jointly in the estimation of the power battery SOC. Simulation experiments show that the joint estimation algorithm proposed in this paper has higher precision and convergence of the initial value error than a single AUKF algorithm.

An Adaptive Gain Nonlinear Observer for State of Charge Estimation of Lithium-Ion Batteries in Electric Vehicles

Directory of Open Access Journals (Sweden)

Yong Tian

2014-09-01

Full Text Available The state of charge (SOC is important for the safety and reliability of battery operation since it indicates the remaining capacity of a battery. However, it is difficult to get an accurate value of SOC, because the SOC cannot be directly measured by a sensor. In this paper, an adaptive gain nonlinear observer (AGNO for SOC estimation of lithium-ion batteries (LIBs in electric vehicles (EVs is proposed. The second-order resistor–capacitor (2RC equivalent circuit model is used to simulate the dynamic behaviors of a LIB, based on which the state equations are derived to design the AGNO for SOC estimation. The model parameters are identified using the exponential-function fitting method. The sixth-order polynomial function is used to describe the highly nonlinear relationship between the open circuit voltage (OCV and the SOC. The convergence of the proposed AGNO is proved using the Lyapunov stability theory. Two typical driving cycles, including the New European Driving Cycle (NEDC and Federal Urban Driving Schedule (FUDS are adopted to evaluate the performance of the AGNO by comparing with the unscented Kalman filter (UKF algorithm. The experimental results show that the AGNO has better performance than the UKF algorithm in terms of reducing the computation cost, improving the estimation accuracy and enhancing the convergence ability.

Numerical analyses on optimizing a heat pipe thermal management system for lithium-ion batteries during fast charging

International Nuclear Information System (INIS)

Ye, Yonghuang; Saw, Lip Huat; Shi, Yixiang; Tay, Andrew A.O.

2015-01-01

Thermal management is crucial for the operation of electric vehicles because lithium ion batteries are vulnerable to excessive heat generation during fast charging or other severe scenarios. In this work, an optimized heat pipe thermal management system (HPTMS) is proposed for fast charging lithium ion battery cell/pack. A numerical model is developed and comprehensively validated with experimental results. This model is then employed to investigate the thermal performance of the HPTMS under steady state and transient conditions. It is found that a cylinder vortex generator placed in front of the heat pipe condensers in the coolant stream improves the temperature uniformity. The uses of cooper heat spreaders and cooling fins greatly improve the performance of the thermal management system. Experiments and transient simulations of heat pipe thermal management system integrated with batteries prove that the improved HPTMS is capable for thermal management of batteries during fast charging. The air-cooled HPTMS is infeasible for thermal management of batteries during fast charging at the pack level due to the limitation of low specific heat capacity. - Highlights: • We develop a numerical model for optimizing a heat pipe thermal management system for fast charging batteries. • The numerical model is comprehensively validated with experimental data. • A cylinder vortex generator is placed at the inlet of the cooling stream to improve the temperature uniformity. • We validate the effectiveness of the optimized system with integration of prismatic batteries

Strain measurement based battery testing

Science.gov (United States)

Xu, Jeff Qiang; Steiber, Joe; Wall, Craig M.; Smith, Robert; Ng, Cheuk

2017-05-23

A method and system for strain-based estimation of the state of health of a battery, from an initial state to an aged state, is provided. A strain gauge is applied to the battery. A first strain measurement is performed on the battery, using the strain gauge, at a selected charge capacity of the battery and at the initial state of the battery. A second strain measurement is performed on the battery, using the strain gauge, at the selected charge capacity of the battery and at the aged state of the battery. The capacity degradation of the battery is estimated as the difference between the first and second strain measurements divided by the first strain measurement.

Development, modeling and research of the system of automatic control and equalization of the charge state of a battery pack of a hybrid engine of a vehicle

Science.gov (United States)

Bakhmutov, S.; Sizov, Y.; Kim, M.

2018-02-01

The article is devoted to the topical problem of developing effective means of monitoring and leveling the charge state of batteries in a power unit of hybrid and electric cars. A system for automatic control and equalization of the charge state of a battery pack of a combined power plant, the originality of which is protected by the Russian Federation patent, is developed and described. A distinctive feature of the device is the possibility of using it both in conditions of charging (power consumption) and in operating conditions (energy recovery). The device is characterized by high reliability, simplicity of the circuit-making solution, low self-consumption and low cost. To test the efficiency of the proposed device, its computer simulation and experimental research were carried out. As a result of multi factorial experiment, a regression equation has been obtained which makes it possible to judge the high efficiency of detecting the degree of inhomogeneity of controlled batteries with respect to the parameters of an equivalent replacement circuit: voltage, internal resistance and capacitance in the magnitude of the obtained coefficients of influence of each of these factors, and also take into account the effects of their pair interactions.

Influence of memory effect on the state-of-charge estimation of large-format Li-ion batteries based on LiFePO4 cathode

Science.gov (United States)

Shi, Wei; Wang, Jiulin; Zheng, Jianming; Jiang, Jiuchun; Viswanathan, Vilayanur; Zhang, Ji-Guang

2016-04-01

In this work, we systematically investigated the influence of the memory effect of LiFePO4 cathodes in large-format full batteries. The electrochemical performance of the electrodes used in these batteries was also investigated separately in half-cells to reveal their intrinsic properties. We noticed that the memory effect of LiFePO4/graphite cells depends not only on the maximum state of charge reached during the memory writing process, but is also affected by the depth of discharge reached during the memory writing process. In addition, the voltage deviation in a LiFePO4/graphite full battery is more complex than in a LiFePO4/Li half-cell, especially for a large-format battery, which exhibits a significant current variation in the region near its terminals. Therefore, the memory effect should be taken into account in advanced battery management systems to further extend the long-term cycling stabilities of Li-ion batteries using LiFePO4 cathodes.

Predicting state of charge of lead-acid batteries for hybrid electric vehicles by extended Kalman filter

International Nuclear Information System (INIS)

Vasebi, A.; Bathaee, S.M.T.; Partovibakhsh, M.

2008-01-01

This paper describes and introduces a new nonlinear predictor and a novel battery model for estimating the state of charge (SoC) of lead-acid batteries for hybrid electric vehicles (HEV). Many problems occur for a traditional SoC indicator, such as offset, drift and long term state divergence, therefore this paper proposes a technique based on the extended Kalman filter (EKF) in order to overcome these problems. The underlying dynamic behavior of each cell is modeled using two capacitors (bulk and surface) and three resistors (terminal, surface and end). The SoC is determined from the voltage present on the bulk capacitor. In this new model, the value of the surface capacitor is constant, whereas the value of the bulk capacitor is not. Although the structure of the model, with two constant capacitors, has been previously reported for lithium-ion cells, this model can also be valid and reliable for lead-acid cells when used in conjunction with an EKF to estimate SoC (with a little variation). Measurements using real-time road data are used to compare the performance of conventional internal resistance (R int ) based methods for estimating SoC with those predicted from the proposed state estimation schemes. The results show that the proposed method is superior to the more traditional techniques, with accuracy in estimating the SoC within 3%

On-board adaptive model for state of charge estimation of lithium-ion batteries based on Kalman filter with proportional integral-based error adjustment

Science.gov (United States)

Wei, Jingwen; Dong, Guangzhong; Chen, Zonghai

2017-10-01

With the rapid development of battery-powered electric vehicles, the lithium-ion battery plays a critical role in the reliability of vehicle system. In order to provide timely management and protection for battery systems, it is necessary to develop a reliable battery model and accurate battery parameters estimation to describe battery dynamic behaviors. Therefore, this paper focuses on an on-board adaptive model for state-of-charge (SOC) estimation of lithium-ion batteries. Firstly, a first-order equivalent circuit battery model is employed to describe battery dynamic characteristics. Then, the recursive least square algorithm and the off-line identification method are used to provide good initial values of model parameters to ensure filter stability and reduce the convergence time. Thirdly, an extended-Kalman-filter (EKF) is applied to on-line estimate battery SOC and model parameters. Considering that the EKF is essentially a first-order Taylor approximation of battery model, which contains inevitable model errors, thus, a proportional integral-based error adjustment technique is employed to improve the performance of EKF method and correct model parameters. Finally, the experimental results on lithium-ion batteries indicate that the proposed EKF with proportional integral-based error adjustment method can provide robust and accurate battery model and on-line parameter estimation.

State-of-Charge Estimation and Active Cell Pack Balancing Design of Lithium Battery Power System for Smart Electric Vehicle

OpenAIRE

Gao, Z. C.; Chin, C. S.; Toh, W. D.; Chiew, J.; Jia, J.

2017-01-01

This paper presents an integrated state-of-charge (SOC) estimation model and active cell balancing of a 12-cell lithium iron phosphate (LiFePO4) battery power system. The strong tracking cubature extended Kalman filter (STCEKF) gave an accurate SOC prediction compared to other Kalman-based filter algorithms. The proposed groupwise balancing of the multiple SOC exhibited a higher balancing speed and lower balancing loss than other cell balancing designs. The experimental results demonstrated t...

Comparative Study Between Internal Ohmic Resistance and Capacity for Battery State of Health Estimation

Directory of Open Access Journals (Sweden)

M. Nisvo Ramadan

2015-12-01

Full Text Available In order to avoid battery failure, a battery management system (BMS is necessary. Battery state of charge (SOC and state of health (SOH are part of information provided by a BMS. This research analyzes methods to estimate SOH based lithium polymer battery on change of its internal resistance and its capacity. Recursive least square (RLS algorithm was used to estimate internal ohmic resistance while coloumb counting was used to predict the change in the battery capacity. For the estimation algorithm, the battery terminal voltage and current are set as the input variables. Some tests including static capacity test, pulse test, pulse variation test and before charge-discharge test have been conducted to obtain the required data. After comparing the two methods, the obtained results show that SOH estimation based on coloumb counting provides better accuracy than SOH estimation based on internal ohmic resistance. However, the SOH estimation based on internal ohmic resistance is faster and more reliable for real application

Nickel-Hydrogen Battery Fault Clearing at Low State of Charge

Science.gov (United States)

Lurie, C.

1997-01-01

Fault clearing currents were achieved and maintained at discharge rates from C/2 to C/3 at high and low states of charge. The fault clearing plateau voltage is strong function of: discharge current, and voltage-prior-to-the-fault-clearing-event and a weak function of state of charge. Voltage performance, for the range of conditions reported, is summarized.

Online state of charge and model parameter co-estimation based on a novel multi-timescale estimator for vanadium redox flow battery

International Nuclear Information System (INIS)

Wei, Zhongbao; Lim, Tuti Mariana; Skyllas-Kazacos, Maria; Wai, Nyunt; Tseng, King Jet

2016-01-01

Highlights: • Battery model parameters and SOC co-estimation is investigated. • The model parameters and OCV are decoupled and estimated independently. • Multiple timescales are adopted to improve precision and stability. • SOC is online estimated without using the open-circuit cell. • The method is robust to aging levels, flow rates, and battery chemistries. - Abstract: A key function of battery management system (BMS) is to provide accurate information of the state of charge (SOC) in real time, and this depends directly on the precise model parameterization. In this paper, a novel multi-timescale estimator is proposed to estimate the model parameters and SOC for vanadium redox flow battery (VRB) in real time. The model parameters and OCV are decoupled and estimated independently, effectively avoiding the possibility of cross interference between them. The analysis of model sensitivity, stability, and precision suggests the necessity of adopting different timescales for each estimator independently. Experiments are conducted to assess the performance of the proposed method. Results reveal that the model parameters are online adapted accurately thus the periodical calibration on them can be avoided. The online estimated terminal voltage and SOC are both benchmarked with the reference values. The proposed multi-timescale estimator has the merits of fast convergence, high precision, and good robustness against the initialization uncertainty, aging states, flow rates, and also battery chemistries.

Lithium-ion battery state of function estimation based on fuzzy logic algorithm with associated variables

Science.gov (United States)

Gan, L.; Yang, F.; Shi, Y. F.; He, H. L.

2017-11-01

Many occasions related to batteries demand to know how much continuous and instantaneous power can batteries provide such as the rapidly developing electric vehicles. As the large-scale applications of lithium-ion batteries, lithium-ion batteries are used to be our research object. Many experiments are designed to get the lithium-ion battery parameters to ensure the relevance and reliability of the estimation. To evaluate the continuous and instantaneous load capability of a battery called state-of-function (SOF), this paper proposes a fuzzy logic algorithm based on battery state-of-charge(SOC), state-of-health(SOH) and C-rate parameters. Simulation and experimental results indicate that the proposed approach is suitable for battery SOF estimation.

Online model-based estimation of state-of-charge and open-circuit voltage of lithium-ion batteries in electric vehicles

International Nuclear Information System (INIS)

He, Hongwen; Zhang, Xiaowei; Xiong, Rui; Xu, Yongli; Guo, Hongqiang

2012-01-01

This paper presents a method to estimate the state-of-charge (SOC) of a lithium-ion battery, based on an online identification of its open-circuit voltage (OCV), according to the battery’s intrinsic relationship between the SOC and the OCV for application in electric vehicles. Firstly an equivalent circuit model with n RC networks is employed modeling the polarization characteristic and the dynamic behavior of the lithium-ion battery, the corresponding equations are built to describe its electric behavior and a recursive function is deduced for the online identification of the OCV, which is implemented by a recursive least squares (RLS) algorithm with an optimal forgetting factor. The models with different RC networks are evaluated based on the terminal voltage comparisons between the model-based simulation and the experiment. Then the OCV-SOC lookup table is built based on the experimental data performed by a linear interpolation of the battery voltages at the same SOC during two consecutive discharge and charge cycles. Finally a verifying experiment is carried out based on nine Urban Dynamometer Driving Schedules. It indicates that the proposed method can ensure an acceptable accuracy of SOC estimation for online application with a maximum error being less than 5.0%. -- Highlights: ► An equivalent circuit model with n RC networks is built for lithium-ion batteries. ► A recursive function is deduced for the online estimation of the model parameters like OCV and R O . ► The relationship between SOC and OCV is built with a linear interpolation method by experiments. ► The experiments show the online model-based SOC estimation is reasonable with enough accuracy.

Supercapacitor performance evaluation in replacing battery based on charging and discharging current characteristics

Science.gov (United States)

Sani, A.; Siahaan, S.; Mubarakah, N.; Suherman

2018-02-01

Supercapacitor is a new device of energy storage, which has much difference between ordinary capacitors and batteries. Supercapacitor have higher capacitance and energy density than regular capacitors. The supercapacitor also has a fast charging time, as well as a long life. To be used as a battery replacement please note the internal parameters of the battery to be replaced. In this paper conducted a simulation study to utilize supercapacitor as a replacement battery. The internal parameters of the battery and the supercapacitor are obtained based on the characteristics of charging and discharging current using a predefined equivalent circuit model. The battery to be replaced is a 12-volt lead-acid type, 6.5 Ah which is used on motorcycles with 6A charging and discharging currents. Super capacitor replacement capacitor is a capacity of 1600F, 2.7V which is connected in series as many as 6 pieces with 16.2 volt terminal voltage and charging current 12A. To obtain the same supercapacitor characteristic as the battery characteristic to be replaced, modification of its internal parameters is made. The results show that the super-capacitor can replace the battery function for 1000 seconds.

An advanced Lithium-ion battery optimal charging strategy based on a coupled thermoelectric model

International Nuclear Information System (INIS)

Liu, Kailong; Li, Kang; Yang, Zhile; Zhang, Cheng; Deng, Jing

2017-01-01

Lithium-ion batteries are widely adopted as the power supplies for electric vehicles. A key but challenging issue is to achieve optimal battery charging, while taking into account of various constraints for safe, efficient and reliable operation. In this paper, a triple-objective function is first formulated for battery charging based on a coupled thermoelectric model. An advanced optimal charging strategy is then proposed to develop the optimal constant-current-constant-voltage (CCCV) charge current profile, which gives the best trade-off among three conflicting but important objectives for battery management. To be specific, a coupled thermoelectric battery model is first presented. Then, a specific triple-objective function consisting of three objectives, namely charging time, energy loss, and temperature rise (both the interior and surface), is proposed. Heuristic methods such as Teaching-learning-based-optimization (TLBO) and particle swarm optimization (PSO) are applied to optimize the triple-objective function, and their optimization performances are compared. The impacts of the weights for different terms in the objective function are then assessed. Experimental results show that the proposed optimal charging strategy is capable of offering desirable effective optimal charging current profiles and a proper trade-off among the conflicting objectives. Further, the proposed optimal charging strategy can be easily extended to other battery types.

System state estimation and optimal energy control framework for multicell lithium-ion battery system

International Nuclear Information System (INIS)

Wei, Jingwen; Dong, Guangzhong; Chen, Zonghai; Kang, Yu

2017-01-01

Highlights: • Employed a dual-scale EKF based estimator for in-pack cells’ SOC values. • Proposed a two-stage hybrid state-feedback and output-feedback equalization algorithm. • A switchable balance current mode is designed in the equalization topology. • Verified the performance of proposed method under two conditions. - Abstract: Cell variations caused by the inevitable inconsistency during manufacture and use of battery cells have significant impacts on battery capacity, security and durability for battery energy storage systems. Thus, the battery equalization systems are essentially required to reduce variations of in-pack cells and increase battery pack capability. In order to protect all in-pack cells from damaging, estimate battery state and reduce variations, a system state estimation and energy optimal control framework for multicell lithium-ion battery system is proposed. The state-of-charge (SOC) values of all in-pack cells are firstly estimated using a dual-scale extended Kalman filtering (EKF) to improve estimation accuracy and reduce computation simultaneously. These estimated SOC values provide specific details of battery system, which cannot only be used to protect cells from over-charging/over-discharging, but also be employed to design state-feedback controller for battery equalization system. A two-stage hybrid state-feedback and output-feedback equalization algorithm is proposed. The state-feedback controller is firstly employed for coarse-grained adjustment to reduce equalization time cost with large current. However, due to the inevitable SOC estimation errors, the output-feedback controller is then used for fine-grained adjustment with trickle current. Experimental results show that the proposed framework can provide an effectively estimation and energy control for multicell battery systems. Finally, the implementation of the proposed method is further discussed for the real applications.

Photovoltaic battery & charge controller market & applications survey. An evaluation of the photovoltaic system market for 1995

Energy Technology Data Exchange (ETDEWEB)

Hammond, R.L.; Turpin, J.F.; Corey, G.P. [and others

1996-12-01

Under the sponsorship of the Department of Energy, Office of Utility Technologies, the Battery Analysis and Evaluation Department and the Photovoltaic System Assistance Center of Sandia National Laboratories (SNL) initiated a U.S. industry-wide PV Energy Storage System Survey. Arizona State University (ASU) was contracted by SNL in June 1995 to conduct the survey. The survey included three separate segments tailored to: (a) PV system integrators, (b) battery manufacturers, and (c) PV charge controller manufacturers. The overall purpose of the survey was to: (a) quantify the market for batteries shipped with (or for) PV systems in 1995, (b) quantify the PV market segments by battery type and application for PV batteries, (c) characterize and quantify the charge controllers used in PV systems, (d) characterize the operating environment for energy storage components in PV systems, and (e) estimate the PV battery market for the year 2000. All three segments of the survey were mailed in January 1996. This report discusses the purpose, methodology, results, and conclusions of the survey.

State-of-charge indication in portable applications

NARCIS (Netherlands)

Pop, V.; Bergveld, H.J.; Notten, P.H.L.; Regtien, Paulus P.L.

2005-01-01

The known methods of state-of-charge (SoC) indication in portable applications are not accurate enough under all practical conditions. The method presented in this paper aims at designing and testing an SoC indication system capable of predicting the remaining capacity of the battery and the

State-of-Charge Indication in Portable Applications

NARCIS (Netherlands)

Pop, V.; Bergveld, H.J.; Notten, P.H.L.; Regtien, Paulus P.L.

2005-01-01

The known methods of state-of-charge (SoC) indication in portable applications are not accurate enough under all practical conditions. The method presented in this paper aims at designing and testing an SoC indication system capable of predicting the remaining capacity of the battery and the

State-of-charge indication for portable applications

NARCIS (Netherlands)

Pop, V.; Bergveld, H.J.; Notten, P.H.L.; Regtien, P.P.L.

2005-01-01

The known methods of state-of-charge (SoC) indication in portable applications are not accurate enough under all practical conditions. The method presented in this paper aims at designing and testing an SoC indication system capable of predicting the remaining capacity of the battery and the

Two-Stage Battery Energy Storage System (BESS in AC Microgrids with Balanced State-of-Charge and Guaranteed Small-Signal Stability

Directory of Open Access Journals (Sweden)

Bing Xie

2018-02-01

Full Text Available In this paper, a two-stage battery energy storage system (BESS is implemented to enhance the operation condition of conventional battery storage systems in a microgrid. Particularly, the designed BESS is composed of two stages, i.e., Stage I: integration of dispersed energy storage units (ESUs using parallel DC/DC converters, and Stage II: aggregated ESUs in grid-connected operation. Different from a conventional BESS consisting of a battery management system (BMS and power conditioning system (PCS, the developed two-stage architecture enables additional operation and control flexibility in balancing the state-of-charge (SoC of each ESU and ensures the guaranteed small-signal stability, especially in extremely weak grid conditions. The above benefits are achieved by separating the control functions between the two stages. In Stage I, a localized power sharing scheme based on the SoC of each particular ESU is developed to manage the SoC and avoid over-charge or over-discharge issues; on the other hand, in Stage II, an additional virtual impedance loop is implemented in the grid-interactive DC/AC inverters to enhance the stability margin with multiple parallel-connected inverters integrating at the point of common coupling (PCC simultaneously. A simulation model based on MATLAB/Simulink is established, and simulation results verify the effectiveness of the proposed BESS architecture and the corresponding control diagram.

An automatic device for charging a storage battery

Energy Technology Data Exchange (ETDEWEB)

Pasyukov, A A

1984-01-01

The purpose of the invention is to increase the service life of storage batteries (AB) through ensuring automatic protection of the device from overloads with short circuits (KZ) and from incorrect switching polarity of the storage batteries. The device contains a transformer, a rectifier, a smoothing capacitor, a trigger capacitor, a charge current control transistor, a controllable transistor, a shielding transistor, two resistors, a diode, a resistor and a voltage divider, another resistor, a reference voltage stabilitron, a resistor and another diode and the storage battery.

On-line adaptive battery impedance parameter and state estimation considering physical principles in reduced order equivalent circuit battery models. Part 1. Requirements, critical review of methods and modeling

Science.gov (United States)

Fleischer, Christian; Waag, Wladislaw; Heyn, Hans-Martin; Sauer, Dirk Uwe

2014-08-01

Lithium-ion battery systems employed in high power demanding systems such as electric vehicles require a sophisticated monitoring system to ensure safe and reliable operation. Three major states of the battery are of special interest and need to be constantly monitored, these include: battery state of charge (SoC), battery state of health (capcity fade determination, SoH), and state of function (power fade determination, SoF). In a series of two papers, we propose a system of algorithms based on a weighted recursive least quadratic squares parameter estimator, that is able to determine the battery impedance and diffusion parameters for accurate state estimation. The functionality was proven on different battery chemistries with different aging conditions. The first paper investigates the general requirements on BMS for HEV/EV applications. In parallel, the commonly used methods for battery monitoring are reviewed to elaborate their strength and weaknesses in terms of the identified requirements for on-line applications. Special emphasis will be placed on real-time capability and memory optimized code for cost-sensitive industrial or automotive applications in which low-cost microcontrollers must be used. Therefore, a battery model is presented which includes the influence of the Butler-Volmer kinetics on the charge-transfer process. Lastly, the mass transport process inside the battery is modeled in a novel state-space representation.

Charge Equalization Controller Algorithm for Series-Connected Lithium-Ion Battery Storage Systems: Modeling and Applications

Directory of Open Access Journals (Sweden)

Mahammad A. Hannan

2017-09-01

Full Text Available This study aims to develop an accurate model of a charge equalization controller (CEC that manages individual cell monitoring and equalizing by charging and discharging series-connected lithium-ion (Li-ion battery cells. In this concept, an intelligent control algorithm is developed to activate bidirectional cell switches and control direct current (DC–DC converter switches along with pulse width modulation (PWM generation. Individual models of an electric vehicle (EV-sustainable Li-ion battery, optimal power rating, a bidirectional flyback DC–DC converter, and charging and discharging controllers are integrated to develop a small-scale CEC model that can be implemented for 10 series-connected Li-ion battery cells. Results show that the charge equalization controller operates at 91% efficiency and performs well in equalizing both overdischarged and overcharged cells on time. Moreover, the outputs of the CEC model show that the desired balancing level occurs at 2% of state of charge difference and that all cells are operated within a normal range. The configuration, execution, control, power loss, cost, size, and efficiency of the developed CEC model are compared with those of existing controllers. The proposed model is proven suitable for high-tech storage systems toward the advancement of sustainable EV technologies and renewable source of applications.

Comparison of Nonlinear Filtering Methods for Estimating the State of Charge of Li4Ti5O12 Lithium-Ion Battery

Directory of Open Access Journals (Sweden)

Jianping Gao

2015-01-01

Full Text Available Accurate state of charge (SoC estimation is of great significance for the lithium-ion battery to ensure its safety operation and to prevent it from overcharging or overdischarging. To achieve reliable SoC estimation for Li4Ti5O12 lithium-ion battery cell, three filtering methods have been compared and evaluated. A main contribution of this study is that a general three-step model-based battery SoC estimation scheme has been proposed. It includes the processes of battery data measurement, parametric modeling, and model-based SoC estimation. With the proposed general scheme, multiple types of model-based SoC estimators have been developed and evaluated for battery management system application. The detailed comparisons on three advanced adaptive filter techniques, which include extend Kalman filter, unscented Kalman filter, and adaptive extend Kalman filter (AEKF, have been implemented with a Li4Ti5O12 lithium-ion battery. The experimental results indicate that the proposed model-based SoC estimation approach with AEKF algorithm, which uses the covariance matching technique, performs well with good accuracy and robustness; the mean absolute error of the SoC estimation is within 1% especially with big SoC initial error.

Infinite-Dimensional Boundary Observer for Lithium-Ion Battery State Estimation

DEFF Research Database (Denmark)

Hasan, Agus; Jouffroy, Jerome

2017-01-01

This paper presents boundary observer design for state-of-charge (SOC) estimation of lithium-ion batteries. The lithium-ion battery dynamics are governed by thermal-electrochemical principles, which mathematically modeled by partial differential equations (PDEs). In general, the model is a reaction......-diffusion equation with time-dependent coefficients. A Luenberger observer is developed using infinite-dimensional backstepping method and uses only a single measurement at the boundary of the battery. The observer gains are computed by solving the observer kernel equation. A numerical example is performed to show...

Rechargeable sodium all-solid-state battery

International Nuclear Information System (INIS)

Zhou, Weidong; Li, Yutao; Xin, Sen; Goodenough, John B.

2017-01-01

A reversible plating/stripping of a dendrite-free metallic-sodium anode with a reduced anode/ceramic interfacial resistance is created by a thin interfacial interlayer formed in situ or by the introduction of a dry polymer film. Wetting of the sodium on the interfacial interlayer suppresses dendrite formation and growth at different discharge/charge C-rates. Furthermore, all-solid-state batteries were obtained with a high cycling stability and Coulombic efficiency at 65 °C.

A Combined State of Charge Estimation Method for Lithium-Ion Batteries Used in a Wide Ambient Temperature Range

Directory of Open Access Journals (Sweden)

Fei Feng

2014-05-01

Full Text Available Ambient temperature is a significant factor that influences the characteristics of lithium-ion batteries, which can produce adverse effects on state of charge (SOC estimation. In this paper, an integrated SOC algorithm that combines an advanced ampere-hour counting (Adv Ah method and multistate open-circuit voltage (multi OCV method, denoted as “Adv Ah + multi OCV”, is proposed. Ah counting is a simple and general method for estimating SOC. However, the available capacity and coulombic efficiency in this method are influenced by the operating states of batteries, such as temperature and current, thereby causing SOC estimation errors. To address this problem, an enhanced Ah counting method that can alter the available capacity and coulombic efficiency according to temperature is proposed during the SOC calculation. Moreover, the battery SOCs between different temperatures can be mutually converted in accordance with the capacity loss. To compensate for the accumulating errors in Ah counting caused by the low precision of current sensors and lack of accurate initial SOC, the OCV method is used for calibration and as a complement. Given the variation of available capacities at different temperatures, rated/non-rated OCV–SOCs are established to estimate the initial SOCs in accordance with the Ah counting SOCs. Two dynamic tests, namely, constant- and alternated-temperature tests, are employed to verify the combined method at different temperatures. The results indicate that our method can provide effective and accurate SOC estimation at different ambient temperatures.

Novel methods for estimating lithium-ion battery state of energy and maximum available energy

International Nuclear Information System (INIS)

Zheng, Linfeng; Zhu, Jianguo; Wang, Guoxiu; He, Tingting; Wei, Yiying

2016-01-01

Highlights: • Study on temperature, current, aging dependencies of maximum available energy. • Study on the various factors dependencies of relationships between SOE and SOC. • A quantitative relationship between SOE and SOC is proposed for SOE estimation. • Estimate maximum available energy by means of moving-window energy-integral. • The robustness and feasibility of the proposed approaches are systematic evaluated. - Abstract: The battery state of energy (SOE) allows a direct determination of the ratio between the remaining and maximum available energy of a battery, which is critical for energy optimization and management in energy storage systems. In this paper, the ambient temperature, battery discharge/charge current rate and cell aging level dependencies of battery maximum available energy and SOE are comprehensively analyzed. An explicit quantitative relationship between SOE and state of charge (SOC) for LiMn_2O_4 battery cells is proposed for SOE estimation, and a moving-window energy-integral technique is incorporated to estimate battery maximum available energy. Experimental results show that the proposed approaches can estimate battery maximum available energy and SOE with high precision. The robustness of the proposed approaches against various operation conditions and cell aging levels is systematically evaluated.

Estimation method of state-of-charge for lithium-ion battery used in hybrid electric vehicles based on variable structure extended kalman filter

Science.gov (United States)

Sun, Yong; Ma, Zilin; Tang, Gongyou; Chen, Zheng; Zhang, Nong

2016-07-01

Since the main power source of hybrid electric vehicle(HEV) is supplied by the power battery, the predicted performance of power battery, especially the state-of-charge(SOC) estimation has attracted great attention in the area of HEV. However, the value of SOC estimation could not be greatly precise so that the running performance of HEV is greatly affected. A variable structure extended kalman filter(VSEKF)-based estimation method, which could be used to analyze the SOC of lithium-ion battery in the fixed driving condition, is presented. First, the general lower-order battery equivalent circuit model(GLM), which includes column accumulation model, open circuit voltage model and the SOC output model, is established, and the off-line and online model parameters are calculated with hybrid pulse power characteristics(HPPC) test data. Next, a VSEKF estimation method of SOC, which integrates the ampere-hour(Ah) integration method and the extended Kalman filter(EKF) method, is executed with different adaptive weighting coefficients, which are determined according to the different values of open-circuit voltage obtained in the corresponding charging or discharging processes. According to the experimental analysis, the faster convergence speed and more accurate simulating results could be obtained using the VSEKF method in the running performance of HEV. The error rate of SOC estimation with the VSEKF method is focused in the range of 5% to 10% comparing with the range of 20% to 30% using the EKF method and the Ah integration method. In Summary, the accuracy of the SOC estimation in the lithium-ion battery cell and the pack of lithium-ion battery system, which is obtained utilizing the VSEKF method has been significantly improved comparing with the Ah integration method and the EKF method. The VSEKF method utilizing in the SOC estimation in the lithium-ion pack of HEV can be widely used in practical driving conditions.

A Comparative Study Based on the Least Square Parameter Identification Method for State of Charge Estimation of a LiFePO4 Battery Pack Using Three Model-Based Algorithms for Electric Vehicles

Directory of Open Access Journals (Sweden)

Taimoor Zahid

2016-09-01

Full Text Available Battery energy storage management for electric vehicles (EV and hybrid EV is the most critical and enabling technology since the dawn of electric vehicle commercialization. A battery system is a complex electrochemical phenomenon whose performance degrades with age and the existence of varying material design. Moreover, it is very tedious and computationally very complex to monitor and control the internal state of a battery’s electrochemical systems. For Thevenin battery model we established a state-space model which had the advantage of simplicity and could be easily implemented and then applied the least square method to identify the battery model parameters. However, accurate state of charge (SoC estimation of a battery, which depends not only on the battery model but also on highly accurate and efficient algorithms, is considered one of the most vital and critical issue for the energy management and power distribution control of EV. In this paper three different estimation methods, i.e., extended Kalman filter (EKF, particle filter (PF and unscented Kalman Filter (UKF, are presented to estimate the SoC of LiFePO4 batteries for an electric vehicle. Battery’s experimental data, current and voltage, are analyzed to identify the Thevenin equivalent model parameters. Using different open circuit voltages the SoC is estimated and compared with respect to the estimation accuracy and initialization error recovery. The experimental results showed that these online SoC estimation methods in combination with different open circuit voltage-state of charge (OCV-SoC curves can effectively limit the error, thus guaranteeing the accuracy and robustness.

Charge-discharge characteristics of nickel/zinc battery with polymer hydrogel electrolyte

Energy Technology Data Exchange (ETDEWEB)

Iwakura, Chiaki; Murakami, Hiroki; Nohara, Shinji; Furukawa, Naoji; Inoue, Hiroshi [Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Sakai, Osaka 599-8531 (Japan)

2005-12-01

A new nickel/zinc (Ni/Zn) battery was assembled by using polymer hydrogel electrolyte prepared from cross-linked potassium poly(acrylate) and KOH aqueous solution, and its charge-discharge characteristics were investigated. The experimental Ni/Zn cell with the polymer hydrogel electrolyte exhibited well-defined charge-discharge curves and remarkably improved charge-discharge cycle performance, compared to that with a KOH aqueous solution. Moreover, it was found that dendritic growth hardly occurred on the zinc electrode surface during charge-discharge cycles in the polymer hydrogel electrolyte. These results indicate that the polymer hydrogel electrolyte can successfully be used in Ni/Zn batteries as an electrolyte with excellent performance. (author)

Charge-discharge characteristics of nickel/zinc battery with polymer hydrogel electrolyte

Science.gov (United States)

Iwakura, Chiaki; Murakami, Hiroki; Nohara, Shinji; Furukawa, Naoji; Inoue, Hiroshi

A new nickel/zinc (Ni/Zn) battery was assembled by using polymer hydrogel electrolyte prepared from cross-linked potassium poly(acrylate) and KOH aqueous solution, and its charge-discharge characteristics were investigated. The experimental Ni/Zn cell with the polymer hydrogel electrolyte exhibited well-defined charge-discharge curves and remarkably improved charge-discharge cycle performance, compared to that with a KOH aqueous solution. Moreover, it was found that dendritic growth hardly occurred on the zinc electrode surface during charge-discharge cycles in the polymer hydrogel electrolyte. These results indicate that the polymer hydrogel electrolyte can successfully be used in Ni/Zn batteries as an electrolyte with excellent performance.

Dynamic Electrochemical Impedance Spectroscopy of a Three-Electrode Lithium-Ion Battery during Pulse Charge and Discharge

International Nuclear Information System (INIS)

Huang, Jun; Ge, Hao; Li, Zhe; Zhang, Jianbo

2015-01-01

Highlights: • Dynamic EIS is performed on a three-electrode pouch cell; • Charge transfer resistance during insertion is generally larger than that during deinsertion due to the surface concentration change; • An inductive behavior is revealed at low frequencies due to the violation of stationary condition in DEIS measurement; • Electrochemical models of a single active particle in both time and frequency domain are developed. • The model predicts a positive correlation between the lower frequency limit and the DC current. - Abstract: The dynamic electrochemical impedance spectroscopy (DEIS) of a three-electrode pouch type lithium-ion battery is measured using a series of sine wave perturbations super-imposed on pulse charge and discharge. The DEIS reveals noticeable differences between charge and discharge at frequencies corresponding to the charge transfer reaction. The charge transfer resistance during intercalation is generally found to be larger than that during deintercalation for the battery chemistry in this study. This result is mainly attributed to the decreased Li ion concentration in the electrolyte during intercalation. At low frequencies, an abnormal inductive behavior is also observed. Such abnormality is found to result from the violation of stationary condition, i.e. the state of the battery under pulse charge or discharge deviates significantly from its initial condition for the perturbation of low frequencies. To analytically define the stationary condition, we develop electrochemical models of a single active particle in both time and frequency domain, which describes the transport of lithium ions in both active particle and electrolyte phase and the interfacial charge transfer reactions at their interface. The lower frequency limit is a key parameter to ensure a quasistationary state during the DEIS measurement. An explicit formulation of the stationary condition predicts a positive correlation between the lower frequency limit and

Impact of Fast Charging on Life of EV Batteries; NREL (National Renewable Energy Laboratory)

Energy Technology Data Exchange (ETDEWEB)

Neubauer, Jeremy; Wood, Eric; Burton, Evan; Smith, Kandler; Pesaran, Ahmad

2015-05-03

Installation of fast charging infrastructure is considered by many as one of potential solutions to increase the utility and range of electric vehicles (EVs). This is expected to reduce the range anxiety of drivers of EVs and thus increase their market penetration. Level 1 and 2 charging in homes and workplaces is expected to contribute to the majority of miles driven by EVs. However, a small percentage of urban driving and most of inter-city driving could be only achieved by a fast-charging network. DC fast charging at 50 kW, 100 kW, 120 kW compared to level 1 (3.3 kW) and level 2 (6.6 kW) results in high-current charging that can adversely impact the life of the battery. In the last couple of years, we have investigated the impact of higher current rates in batteries and potential of higher temperatures and thus lower service life. Using mathematical models, we investigated the temperature increase of batteries due to higher heat generation during fast charge and have found that this could lead to higher temperatures. We compared our models with data from other national laboratories both for fine-tuning and calibration. We found that the incremental temperature rise of batteries during 1C to 3C fast charging may reduce the practical life of the batteries by less than 10% over 10 to 15 years of vehicle ownership. We also found that thermal management of batteries is needed for fast charging to prevent high temperature excursions leading to unsafe conditions.

Simulation and Comparison of HEV Battery Control for Best Fuel Economy and Longer Battery Life

OpenAIRE

Adel, Boukehili; Youtong, Zhang; shuai, Sun

2010-01-01

Almost all HEV battery control strategies keep the battery state of charge (SOC) within a lower limit (SOCmin) (these strategies also called charge sustaining strategies). The goal from sustaining the SOC in this way is to prolong the battery life. But the question is

System dynamic model and charging control of lead-acid battery for stand-alone solar PV system

KAUST Repository

Huang, B.J.

2010-05-01

The lead-acid battery which is widely used in stand-alone solar system is easily damaged by a poor charging control which causes overcharging. The battery charging control is thus usually designed to stop charging after the overcharge point. This will reduce the storage energy capacity and reduce the service time in electricity supply. The design of charging control system however requires a good understanding of the system dynamic behaviour of the battery first. In the present study, a first-order system dynamics model of lead-acid battery at different operating points near the overcharge voltage was derived experimentally, from which a charging control system based on PI algorithm was developed using PWM charging technique. The feedback control system for battery charging after the overcharge point (14 V) was designed to compromise between the set-point response and the disturbance rejection. The experimental results show that the control system can suppress the battery voltage overshoot within 0.1 V when the solar irradiation is suddenly changed from 337 to 843 W/m2. A long-term outdoor test for a solar LED lighting system shows that the battery voltage never exceeded 14.1 V for the set point 14 V and the control system can prevent the battery from overcharging. The test result also indicates that the control system is able to increase the charged energy by 78%, as compared to the case that the charging stops after the overcharge point (14 V). © 2010 Elsevier Ltd. All rights reserved.

A comparative study of kalman filtering based observer and sliding mode observer for state of charge estimation

Science.gov (United States)

Ben Sassi, Hicham; Errahimi, Fatima; Es-Sbai, Najia; Alaoui, Chakib

2018-05-01

Nowadays, electric mobility is starting to define society and is becoming more and more irreplaceable and essential to daily activities. Safe and durable battery is of a great significance for this type of mobility, hence the increasing interest of research activity oriented to battery studies, in order to assure safe operating mode and to control the battery in case of any abnormal functioning conditions that could damage the battery if not properly managed. Lithium-ion technology is considered the most suitable existing technology for electrical storage, because of their interesting features such as their relatively long cycle life, lighter weight, their high energy density, However, there is a lot of work that is still needed to be done in order to assure safe operating lithium-ion batteries, starting with their internal status monitoring, cell balancing within a battery pack, and thermal management. Tasks that are accomplished by the battery management system (BMS) which uses the state of charge (SOC) as an indicator of the internal charge level of the battery, in order to avoid unpredicted system interruption. Since the state of charge is an inner state of a the battery which cannot be directly measured, a powerful estimation technique is inevitable, in this paper we investigate the performances of tow estimation strategies; kalman filtering based observers and sliding mode observers, both strategies are compared in terms of accuracy, design requirement, and overall performances.

Electrolyte additive enabled fast charging and stable cycling lithium metal batteries

Energy Technology Data Exchange (ETDEWEB)

Zheng, Jianming; Engelhard, Mark H.; Mei, Donghai; Jiao, Shuhong; Polzin, Bryant J.; Zhang, Ji-Guang; Xu, Wu

2017-03-01

Batteries using lithium (Li) metal as anodes are considered promising energy storage systems because of their high energy densities. However, safety concerns associated with dendrite growth along with limited cycle life, especially at high charge current densities, hinder their practical uses. Here we report that an optimal amount (0.05 M) of LiPF6 as an additive in LiTFSI-LiBOB dual-salt/carbonate-solvent-based electrolytes significantly enhances the charging capability and cycling stability of Li metal batteries. In a Li metal battery using a 4-V Li-ion cathode at a moderately high loading of 1.75mAh cm(-2), a cyclability of 97.1% capacity retention after 500 cycles along with very limited increase in electrode overpotential is accomplished at a charge/discharge current density up to 1.75 mA cm(-2). The fast charging and stable cycling performances are ascribed to the generation of a robust and conductive solid electrolyte interphase at the Li metal surface and stabilization of the Al cathode current collector.

All-Solid-State Textile Batteries Made from Nano-Emulsion Conducting Polymer Inks for Wearable Electronics

Directory of Open Access Journals (Sweden)

Tapani Ryhänen

2012-08-01

Full Text Available A rollable and all-solid-state textile lithium battery based on fabric matrix and polymer electrolyte that allows flexibility and fast-charging capability is reported. When immerged into poly(3,4-ethylenedioxythiophene (PEDOT nano-emulsion inks, an insulating fabric is converted into a conductive battery electrode for a fully solid state lithium battery with the highest specific energy capacity of 68 mAh/g. This is superior to most of the solid-state conducting polymer primary and/or secondary batteries reported. The bending radius of such a textile battery is less than 1.5 mm while lightening up an LED. This new material combination and inherent flexibility is well suited to provide an energy source for future wearable and woven electronics.

A comprehensive review of on-board State-of-Available-Power prediction techniques for lithium-ion batteries in electric vehicles

Science.gov (United States)

Farmann, Alexander; Sauer, Dirk Uwe

2016-10-01

This study provides an overview of available techniques for on-board State-of-Available-Power (SoAP) prediction of lithium-ion batteries (LIBs) in electric vehicles. Different approaches dealing with the on-board estimation of battery State-of-Charge (SoC) or State-of-Health (SoH) have been extensively discussed in various researches in the past. However, the topic of SoAP prediction has not been explored comprehensively yet. The prediction of the maximum power that can be applied to the battery by discharging or charging it during acceleration, regenerative braking and gradient climbing is definitely one of the most challenging tasks of battery management systems. In large lithium-ion battery packs because of many factors, such as temperature distribution, cell-to-cell deviations regarding the actual battery impedance or capacity either in initial or aged state, the use of efficient and reliable methods for battery state estimation is required. The available battery power is limited by the safe operating area (SOA), where SOA is defined by battery temperature, current, voltage and SoC. Accurate SoAP prediction allows the energy management system to regulate the power flow of the vehicle more precisely and optimize battery performance and improve its lifetime accordingly. To this end, scientific and technical literature sources are studied and available approaches are reviewed.

Modeling the effect of shunt current on the charge transfer efficiency of an all-vanadium redox flow battery

Science.gov (United States)

Chen, Yong-Song; Ho, Sze-Yuan; Chou, Han-Wen; Wei, Hwa-Jou

2018-06-01

In an all-vanadium redox flow battery (VRFB), a shunt current is inevitable owing to the electrically conductive electrolyte that fills the flow channels and manifolds connecting cells. The shunt current decreases the performance of a VRFB stack as well as the energy conversion efficiency of a VRFB system. To understand the shunt-current loss in a VRFB stack with various designs and operating conditions, a mathematical model is developed to investigate the effects of the shunt current on battery performance. The model is calibrated with experimental data under the same operating conditions. The effects of the battery design, including the number of cells, state of charge (SOC), operating current, and equivalent resistance of the electrolytes in the flow channels and manifolds, on the shunt current are analyzed and discussed. The charge-transfer efficiency is calculated to investigate the effects of the battery design parameters on the shunt current. When the cell number is increased from 5 to 40, the charge transfer efficiency is decreased from 0.99 to a range between 0.76 and 0.88, depending on operating current density. The charge transfer efficiency can be maintained at higher than 0.9 by limiting the cell number to less than 20.

Non-destructive fast charging algorithm of lithium-ion batteries based on the control-oriented electrochemical model

International Nuclear Information System (INIS)

Chu, Zhengyu; Feng, Xuning; Lu, Languang; Li, Jianqiu; Han, Xuebing; Ouyang, Minggao

2017-01-01

Highlights: •A novel non-destructive fast charging algorithm of lithium-ion batteries is proposed. •A close-loop observer of lithium deposition status is constructed based on the SP2D model. •The charging current is modified online using the feedback of the lithium deposition status. •The algorithm can shorten the charging time and can be used for charging from different initial SOCs. •The post-mortem observation and degradation tests show that no lithium deposition occurs during fast charging. -- Abstract: Fast charging is critical for the application of lithium-ion batteries in electric vehicles. Conventional fast charging algorithms may shorten the cycle life of lithium-ion batteries and induce safety problems, such as internal short circuit caused by lithium deposition at the negative electrode. In this paper, a novel, non-destructive model-based fast charging algorithm is proposed. The fast charging algorithm is composed of two closed loops. The first loop includes an anode over-potential observer that can observe the status of lithium deposition online, whereas the second loop includes a feedback structure that can modify the current based on the observed status of lithium deposition. The charging algorithm enhances the charging current to maintain the observed anode over-potential near the preset threshold potential. Therefore, the fast charging algorithm can decrease the charging time while protecting the health of the battery. The fast charging algorithm is validated on a commercial large-format nickel cobalt manganese/graphite cell. The results showed that 96.8% of the battery capacity can be charged within 52 min. The post-mortem observation of the surface of the negative electrode and degradation tests revealed that the fast charging algorithm proposed here protected the battery from lithium deposition.

A comparative study of three model-based algorithms for estimating state-of-charge of lithium-ion batteries under a new combined dynamic loading profile

International Nuclear Information System (INIS)

Yang, Fangfang; Xing, Yinjiao; Wang, Dong; Tsui, Kwok-Leung

2016-01-01

Highlights: • Three different model-based filtering algorithms for SOC estimation are compared. • A combined dynamic loading profile is proposed to evaluate the three algorithms. • Robustness against uncertainty of initial states of SOC estimators are investigated. • Battery capacity degradation is considered in SOC estimation. - Abstract: Accurate state-of-charge (SOC) estimation is critical for the safety and reliability of battery management systems in electric vehicles. Because SOC cannot be directly measured and SOC estimation is affected by many factors, such as ambient temperature, battery aging, and current rate, a robust SOC estimation approach is necessary to be developed so as to deal with time-varying and nonlinear battery systems. In this paper, three popular model-based filtering algorithms, including extended Kalman filter, unscented Kalman filter, and particle filter, are respectively used to estimate SOC and their performances regarding to tracking accuracy, computation time, robustness against uncertainty of initial values of SOC, and battery degradation, are compared. To evaluate the performances of these algorithms, a new combined dynamic loading profile composed of the dynamic stress test, the federal urban driving schedule and the US06 is proposed. The comparison results showed that the unscented Kalman filter is the most robust to different initial values of SOC, while the particle filter owns the fastest convergence ability when an initial guess of SOC is far from a true initial SOC.

A Bi-Level Optimization Approach to Charging Load Regulation of Electric Vehicle Fast Charging Stations Based on a Battery Energy Storage System

Directory of Open Access Journals (Sweden)

Yan Bao

2018-01-01

Full Text Available Fast charging stations enable the high-powered rapid recharging of electric vehicles. However, these stations also face challenges due to power fluctuations, high peak loads, and low load factors, affecting the reliable and economic operation of charging stations and distribution networks. This paper introduces a battery energy storage system (BESS for charging load control, which is a more user-friendly approach and is more robust to perturbations. With the goals of peak-shaving, total electricity cost reduction, and minimization of variation in the state-of-charge (SOC range, a BESS-based bi-level optimization strategy for the charging load regulation of fast charging stations is proposed in this paper. At the first level, a day-ahead optimization strategy generates the optimal planned load curve and the deviation band to be used as a reference for ensuring multiple control objectives through linear programming, and even for avoiding control failure caused by insufficient BESS energy. Based on this day-ahead optimal plan, at a second level, real-time rolling optimization converts the control process to a multistage decision-making problem. The predictive control-based real-time rolling optimization strategy in the proposed model was used to achieve the above control objectives and maintain battery life. Finally, through a horizontal comparison of two control approaches in each case study, and a longitudinal comparison of the control robustness against different degrees of load disturbances in three cases, the results indicated that the proposed control strategy was able to significantly improve the charging load characteristics, even with large disturbances. Meanwhile, the proposed approach ensures the least amount of variation in the range of battery SOC and reduces the total electricity cost, which will be of a considerable benefit to station operators.

Understanding the molecular mechanism of pulse current charging for stable lithium-metal batteries

Science.gov (United States)

Li, Qi; Tan, Shen; Li, Linlin; Lu, Yingying; He, Yi

2017-01-01

High energy and safe electrochemical storage are critical components in multiple emerging fields of technologies. Rechargeable lithium-metal batteries are considered to be promising alternatives for current lithium-ion batteries, leading to as much as a 10-fold improvement in anode storage capacity (from 372 to 3860 mAh g−1). One of the major challenges for commercializing lithium-metal batteries is the reliability and safety issue, which is often associated with uneven lithium electrodeposition (lithium dendrites) during the charging stage of the battery cycling process. We report that stable lithium-metal batteries can be achieved by simply charging cells with square-wave pulse current. We investigated the effects of charging period and frequency as well as the mechanisms that govern this process at the molecular level. Molecular simulations were performed to study the diffusion and the solvation structure of lithium cations (Li+) in bulk electrolyte. The model predicts that loose association between cations and anions can enhance the transport of Li+ and eventually stabilize the lithium electrodeposition. We also performed galvanostatic measurements to evaluate the cycling behavior and cell lifetime under pulsed electric field and found that the cell lifetime can be more than doubled using certain pulse current waveforms. Both experimental and simulation results demonstrate that the effectiveness of pulse current charging on dendrite suppression can be optimized by choosing proper time- and frequency-dependent pulses. This work provides a molecular basis for understanding the mechanisms of pulse current charging to mitigating lithium dendrites and designing pulse current waveforms for stable lithium-metal batteries. PMID:28776039

Study of nickel hydrogen battery discharge performance after charge and stand at warm temperature

International Nuclear Information System (INIS)

Donley, S.W.; Verrier, D.C.

1992-01-01

Spacecraft batteries are normally installed in the discharged condition. It may be necessary that they be charged and trickle-charged prior to launch in an environment different from that in which they are intended to operate. The purpose of the testing described in this paper was to determine the battery capacity achieved after treatment at prelaunch conditions as a function of charge rate, charge temperature, trickle charge temperature, and time. In this testing the discharge in every case was performed under simulated space thermal conditions

Unbiased, complete solar charging of a neutral flow battery by a single Si photocathode

DEFF Research Database (Denmark)

Wedege, Kristina; Bae, Dowon; Dražević, Emil

2018-01-01

Solar redox flow batteries have attracted attention as a possible integrated technology for simultaneous conversion and storage of solar energy. In this work, we review current efforts to design aqueous solar flow batteries in terms of battery electrolyte capacity, solar conversion efficiency...... and depth of solar charge. From a materials cost and design perspective, a simple, cost-efficient, aqueous solar redox flow battery will most likely incorporate only one semiconductor, and we demonstrate here a system where a single photocathode is accurately matched to the redox couples to allow...... for a complete solar charge. The single TiO2 protected Si photocathode with a catalytic Pt layer can fully solar charge a neutral TEMPO-sulfate/ferricyanide battery with a cell voltage of 0.35 V. An unbiased solar conversion efficiency of 1.6% is obtained and this system represents a new strategy in solar RFBs...

Enhanced Prognostic Model for Lithium Ion Batteries Based on Particle Filter State Transition Model Modification

Directory of Open Access Journals (Sweden)

Buddhi Arachchige

2017-11-01

Full Text Available This paper focuses on predicting the End of Life and End of Discharge of Lithium ion batteries using a battery capacity fade model and a battery discharge model. The proposed framework will be able to estimate the Remaining Useful Life (RUL and the Remaining charge through capacity fade and discharge models. A particle filter is implemented that estimates the battery’s State of Charge (SOC and State of Life (SOL by utilizing the battery’s physical data such as voltage, temperature, and current measurements. The accuracy of the prognostic framework has been improved by enhancing the particle filter state transition model to incorporate different environmental and loading conditions without retuning the model parameters. The effect of capacity fade in the reduction of the EOD (End of Discharge time with cycling has also been included, integrating both EOL (End of Life and EOD prediction models in order to get more accuracy in the estimations.

Battery model for electrical power system energy balance

Science.gov (United States)

Hafen, D. P.

1983-01-01

A model to simulate nickel-cadmium battery performance and response in a spacecraft electrical power system energy balance calculation was developed. The voltage of the battery is given as a function of temperature, operating depth-of-charge (DOD), and battery state-of-charge. Also accounted for is charge inefficiency. A battery is modeled by analysis of the results of a multiparameter battery cycling test at various temperatures and DOD's.

Lithium-ion Battery Charge Methodologies Observed with Portable Electronic Equipment

Science.gov (United States)

Jeevarajan, Judith

2009-01-01

Commercial lithium-ion batteries in portable electronic equipment has been used by NASA for space applications since 1999. First battery that was certified for flight and flown for Shuttle use was the Canon BP 927 (2.7 Ah) battery pack. Since then, numerous portable equipment with li-ion batteries have been certified and flown and remain on-orbit for crew usage. Laptops (two generations with third one being worked on now) Camcorder Camera PDA 2 versions (second one being li-ion polymer cells) Satellite Phone Due to expense and time, certified batteries are used with different equipment with the help of adapters or by working with the manufacturer of the equipment to build the appropriate battery compartment and connector. Certified and dedicated chargers are available on Shuttle and on the ISS for safe charging.

Comparisons of Modeling and State of Charge Estimation for Lithium-Ion Battery Based on Fractional Order and Integral Order Methods

Directory of Open Access Journals (Sweden)

Renxin Xiao

2016-03-01

Full Text Available In order to properly manage lithium-ion batteries of electric vehicles (EVs, it is essential to build the battery model and estimate the state of charge (SOC. In this paper, the fractional order forms of Thevenin and partnership for a new generation of vehicles (PNGV models are built, of which the model parameters including the fractional orders and the corresponding resistance and capacitance values are simultaneously identified based on genetic algorithm (GA. The relationships between different model parameters and SOC are established and analyzed. The calculation precisions of the fractional order model (FOM and integral order model (IOM are validated and compared under hybrid test cycles. Finally, extended Kalman filter (EKF is employed to estimate the SOC based on different models. The results prove that the FOMs can simulate the output voltage more accurately and the fractional order EKF (FOEKF can estimate the SOC more precisely under dynamic conditions.

Cost-effectiveness of plug-in hybrid electric vehicle battery capacity and charging infrastructure investment for reducing US gasoline consumption

International Nuclear Information System (INIS)

Peterson, Scott B.; Michalek, Jeremy J.

2013-01-01

Federal electric vehicle (EV) policies in the United States currently include vehicle purchase subsidies linked to EV battery capacity and subsidies for installing charging stations. We assess the cost-effectiveness of increased battery capacity vs. nondomestic charging infrastructure installation for plug-in hybrid electric vehicles as alternate methods to reduce gasoline consumption for cars, trucks, and SUVs in the US. We find across a wide range of scenarios that the least-cost solution is for more drivers to switch to low-capacity plug-in hybrid electric vehicles (short electric range with gasoline backup for long trips) or gasoline-powered hybrid electric vehicles. If more gasoline savings are needed per vehicle, nondomestic charging infrastructure installation is substantially more expensive than increased battery capacity per gallon saved, and both approaches have higher costs than US oil premium estimates. Cost effectiveness of all subsidies are lower under a binding fuel economy standard. Comparison of results to the structure of current federal subsidies shows that policy is not aligned with fuel savings potential, and we discuss issues and alternatives. - Highlights: ► We compare cost of PHEV batteries vs. charging infrastructure per gallon of gasoline saved. ► The lowest cost solution is to switch more drivers to low-capacity PHEVs and HEVs. ► If more gasoline savings is needed, batteries offer a better value than chargers. ► Extra batteries and chargers are both more costly per gal than oil premium estimates. ► Current subsidies are misaligned with fuel savings. We discuss alternatives.

Off-grid photovoltaic vehicle charge using second life lithium batteries: An experimental and numerical investigation

International Nuclear Information System (INIS)

Tong, Shi Jie; Same, Adam; Kootstra, Mark A.; Park, Jae Wan

2013-01-01

Highlights: ► We have examined the feasibility of a second life battery pack for an off-grid photovoltaic vehicle charging system. ► The second life battery successfully achieved the desired function using simple control methods. ► The system has been modeled using equivalent circuit techniques. ► The model can simulate the system’s performance under different application scenarios. - Abstract: Partially degraded lithium batteries from automotive applications, also known as second life batteries, are becoming more available for secondary applications due to the increasing market share of plug-in hybrid and electric vehicles. This study examines the feasibility of installing a second life battery pack in an off-grid photovoltaic vehicle charging system. The system was constructed using a photovoltaic array to charge a battery pack via a maximum power point tracking controller and later charge a vehicle via an inverter. The battery pack was configured using 135 second life LiFePO 4 based battery cells, selected based on remaining capacity, connected to form a nine parallel by 15 serial battery pack with accessible storage capacity of 13.9 kW h. Experimental results show that the proposed second life battery system successfully achieves the desired function with a simple system structure and control methods. A numerical simulation was performed by constructing an equivalent system model, where the photovoltaic array and battery pack were modeled using equivalent circuit techniques. The model was parameterized and validated via testing of the system. Coupled with weather data, the model can simulate the system’s performance under different application scenarios. The numerical investigation reveals that the proposed system, using second life batteries, can achieve similar performance to systems using new lithium batteries, but at a reduced cost

Sunlight-charged electrochromic battery based on hybrid film of tungsten oxide and polyaniline

Science.gov (United States)

Chang, Xueting; Hu, Ruirui; Sun, Shibin; Liu, Jingrong; Lei, Yanhua; Liu, Tao; Dong, Lihua; Yin, Yansheng

2018-05-01

Electrochromic (EC) energy storage devices that could realize the multifunctional integration of energy storage and electrochromism have gained much recent attention. Herein, an EC battery based on the hybrid film of W18O49 and polyaniline (PANI) is developed and assembled, which integrates energy storage and EC functions in one device. The W18O49/PANI-EC battery delivers a discharging capacity of 52.96 mA h g-1, which is about two times higher than that of the W18O49-EC battery. Sunlight irradiation could greatly promote the oxidation reactions of both W18O49 and PANI during the charging process of the W18O49/PANI-EC battery, thus effectively accelerating the charging rate. This work provides a green, convenient, environmentally friendly, and cost-free charging strategy for the EC energy systems and could further advance the development of the multifunctional EC devices based on the organic/inorganic composites.

Investigating the error sources of the online state of charge estimation methods for lithium-ion batteries in electric vehicles

Science.gov (United States)

Zheng, Yuejiu; Ouyang, Minggao; Han, Xuebing; Lu, Languang; Li, Jianqiu

2018-02-01

Sate of charge (SOC) estimation is generally acknowledged as one of the most important functions in battery management system for lithium-ion batteries in new energy vehicles. Though every effort is made for various online SOC estimation methods to reliably increase the estimation accuracy as much as possible within the limited on-chip resources, little literature discusses the error sources for those SOC estimation methods. This paper firstly reviews the commonly studied SOC estimation methods from a conventional classification. A novel perspective focusing on the error analysis of the SOC estimation methods is proposed. SOC estimation methods are analyzed from the views of the measured values, models, algorithms and state parameters. Subsequently, the error flow charts are proposed to analyze the error sources from the signal measurement to the models and algorithms for the widely used online SOC estimation methods in new energy vehicles. Finally, with the consideration of the working conditions, choosing more reliable and applicable SOC estimation methods is discussed, and the future development of the promising online SOC estimation methods is suggested.

Stability Analysis for Li-Ion Battery Model Parameters and State of Charge Estimation by Measurement Uncertainty Consideration

Directory of Open Access Journals (Sweden)

Shifei Yuan

2015-07-01

Full Text Available Accurate estimation of model parameters and state of charge (SoC is crucial for the lithium-ion battery management system (BMS. In this paper, the stability of the model parameters and SoC estimation under measurement uncertainty is evaluated by three different factors: (i sampling periods of 1/0.5/0.1 s; (ii current sensor precisions of ±5/±50/±500 mA; and (iii voltage sensor precisions of ±1/±2.5/±5 mV. Firstly, the numerical model stability analysis and parametric sensitivity analysis for battery model parameters are conducted under sampling frequency of 1–50 Hz. The perturbation analysis is theoretically performed of current/voltage measurement uncertainty on model parameter variation. Secondly, the impact of three different factors on the model parameters and SoC estimation was evaluated with the federal urban driving sequence (FUDS profile. The bias correction recursive least square (CRLS and adaptive extended Kalman filter (AEKF algorithm were adopted to estimate the model parameters and SoC jointly. Finally, the simulation results were compared and some insightful findings were concluded. For the given battery model and parameter estimation algorithm, the sampling period, and current/voltage sampling accuracy presented a non-negligible effect on the estimation results of model parameters. This research revealed the influence of the measurement uncertainty on the model parameter estimation, which will provide the guidelines to select a reasonable sampling period and the current/voltage sensor sampling precisions in engineering applications.

Evaluation of Lithium-Ion Battery Equivalent Circuit Models for State of Charge Estimation by an Experimental Approach

Directory of Open Access Journals (Sweden)

Jinxin Fan

2011-03-01

Full Text Available To improve the use of lithium-ion batteries in electric vehicle (EV applications, evaluations and comparisons of different equivalent circuit models are presented in this paper. Based on an analysis of the traditional lithium-ion battery equivalent circuit models such as the Rint, RC, Thevenin and PNGV models, an improved Thevenin model, named dual polarization (DP model, is put forward by adding an extra RC to simulate the electrochemical polarization and concentration polarization separately. The model parameters are identified with a genetic algorithm, which is used to find the optimal time constant of the model, and the experimental data from a Hybrid Pulse Power Characterization (HPPC test on a LiMn2O4 battery module. Evaluations on the five models are carried out from the point of view of the dynamic performance and the state of charge (SoC estimation. The dynamic performances of the five models are obtained by conducting the Dynamic Stress Test (DST and the accuracy of SoC estimation with the Robust Extended Kalman Filter (REKF approach is determined by performing a Federal Urban Driving Schedules (FUDS experiment. By comparison, the DP model has the best dynamic performance and provides the most accurate SoC estimation. Finally, sensitivity of the different SoC initial values is investigated based on the accuracy of SoC estimation with the REKF approach based on the DP model. It is clear that the errors resulting from the SoC initial value are significantly reduced and the true SoC is convergent within an acceptable error.

Nonlinear Dynamics and Bifurcation Analysis of a Boost Converter for Battery Charging in Photovoltaic Applications

Science.gov (United States)

Al-Hindawi, Mohammed M.; Abusorrah, Abdullah; Al-Turki, Yusuf; Giaouris, Damian; Mandal, Kuntal; Banerjee, Soumitro

Photovoltaic (PV) systems with a battery back-up form an integral part of distributed generation systems and therefore have recently attracted a lot of interest. In this paper, we consider a system of charging a battery from a PV panel through a current mode controlled boost dc-dc converter. We analyze its complete nonlinear/nonsmooth dynamics, using a piecewise model of the converter and realistic nonlinear v-i characteristics of the PV panel. Through this study, it is revealed that system design without taking into account the nonsmooth dynamics of the converter combined with the nonlinear v-i characteristics of the PV panel can lead to unpredictable responses of the overall system with high current ripple and other undesirable phenomena. This analysis can lead to better designed converters that can operate under a wide variation of the solar irradiation and the battery's state of charge. We show that the v-i characteristics of the PV panel combined with the battery's output voltage variation can increase or decrease the converter's robustness, both under peak current mode control and average current mode control. We justify the observation in terms of the change in the discrete-time map caused by the nonlinear v-i characteristics of the PV panel. The theoretical results are validated experimentally.

Fading Kalman filter-based real-time state of charge estimation in LiFePO_4 battery-powered electric vehicles

International Nuclear Information System (INIS)

Lim, KaiChin; Bastawrous, Hany Ayad; Duong, Van-Huan; See, Khay Wai; Zhang, Peng; Dou, Shi Xue

2016-01-01

Highlights: • Real-time battery model parameters and SoC estimation with novel method is proposed. • Cascading filtering stages are used for parameters identification and SoC estimation. • Optimized fading Kalman filter is implemented for SoC estimation. • Accurate SoC estimation is validated in UDDS load profile experiment. • This approach is suitable for BMS in EV applications due to its simplicity. - Abstract: A novel online estimation technique for estimating the state of charge (SoC) of a lithium iron phosphate (LiFePO_4) battery has been developed. Based on a simplified model, the open circuit voltage (OCV) of the battery is estimated through two cascaded linear filtering stages. A recursive least squares filter is employed in the first stage to dynamically estimate the battery model parameters in real-time, and then, a fading Kalman filter (FKF) is used to estimate the OCV from these parameters. FKF can avoid the possibility of large estimation errors, which may occur with a conventional Kalman filter, due to its capability to compensate any modeling error through a fading factor. By optimizing the value of the fading factor in the set of recursion equations of FKF with genetic algorithms, the errors in estimating the battery’s SoC in urban dynamometer driving schedules-based experiments and real vehicle driving cycle experiments were below 3% compared to more than 9% in the case of using an ordinary Kalman filter. The proposed method with its simplified model provides the simplicity and feasibility required for real-time application with highly accurate SoC estimation.

Practical state of health estimation of power batteries based on Delphi method and grey relational grade analysis

Science.gov (United States)

Sun, Bingxiang; Jiang, Jiuchun; Zheng, Fangdan; Zhao, Wei; Liaw, Bor Yann; Ruan, Haijun; Han, Zhiqiang; Zhang, Weige

2015-05-01

The state of health (SOH) estimation is very critical to battery management system to ensure the safety and reliability of EV battery operation. Here, we used a unique hybrid approach to enable complex SOH estimations. The approach hybridizes the Delphi method known for its simplicity and effectiveness in applying weighting factors for complicated decision-making and the grey relational grade analysis (GRGA) for multi-factor optimization. Six critical factors were used in the consideration for SOH estimation: peak power at 30% state-of-charge (SOC), capacity, the voltage drop at 30% SOC with a C/3 pulse, the temperature rises at the end of discharge and charge at 1C; respectively, and the open circuit voltage at the end of charge after 1-h rest. The weighting of these factors for SOH estimation was scored by the 'experts' in the Delphi method, indicating the influencing power of each factor on SOH. The parameters for these factors expressing the battery state variations are optimized by GRGA. Eight battery cells were used to illustrate the principle and methodology to estimate the SOH by this hybrid approach, and the results were compared with those based on capacity and power capability. The contrast among different SOH estimations is discussed.

Smart and accurate state-of-charge indication in portable applications

NARCIS (Netherlands)

Pop, V.; Bergveld, H.J.; Notten, P.H.L.; Regtien, P.P.L.

2005-01-01

Accurate state-of-charge (SoC) and remaining run-time indication for portable devices is important for the user-convenience and to prolong the lifetime of batteries. However, the known methods of SoC indication in portable applications are not accurate enough under all practical conditions. The

Smart and accurate State-of-Charge indication in Portable Applications

NARCIS (Netherlands)

Pop, V.; Bergveld, H.J.; Notten, P.H.L.; Regtien, Paulus P.L.

2006-01-01

Accurate state-of-charge (SoC) and remaining run-time indication for portable devices is important for the user-convenience and to prolong the lifetime of batteries. However, the known methods of SoC indication in portable applications are not accurate enough under all practical conditions. The

On the optimal sizing of batteries for electric vehicles and the influence of fast charge

Science.gov (United States)

Verbrugge, Mark W.; Wampler, Charles W.

2018-04-01

We provide a brief summary of advanced battery technologies and a framework (i.e., a simple model) for assessing electric-vehicle (EV) architectures and associated costs to the customer. The end result is a qualitative model that can be used to calculate the optimal EV range (which maps back to the battery size and performance), including the influence of fast charge. We are seeing two technological pathways emerging: fast-charge-capable batteries versus batteries with much higher energy densities (and specific energies) but without the capability to fast charge. How do we compare and contrast the two alternatives? This work seeks to shed light on the question. We consider costs associated with the cells, added mass due to the use of larger batteries, and charging, three factors common in such analyses. In addition, we consider a new cost input, namely, the cost of adaption, corresponding to the days a customer would need an alternative form of transportation, as the EV would not have sufficient range on those days.

A Review on Battery Charging and Discharging Control Strategies: Application to Renewable Energy Systems

Directory of Open Access Journals (Sweden)

Edison Banguero

2018-04-01

Full Text Available Energy storage has become a fundamental component in renewable energy systems, especially those including batteries. However, in charging and discharging processes, some of the parameters are not controlled by the battery’s user. That uncontrolled working leads to aging of the batteries and a reduction of their life cycle. Therefore, it causes an early replacement. Development of control methods seeks battery protection and a longer life expectancy, thus the constant-current–constant-voltage method is mostly used. However, several studies show that charging time can be reduced by using fuzzy logic control or model predictive control. Another benefit is temperature control. This paper reviews the existing control methods used to control charging and discharging processes, focusing on their impacts on battery life. Classical and modern methods are studied together in order to find the best approach to real systems.

Wind driven mobile charging of automobile battery- A case study ...

African Journals Online (AJOL)

This paper deals with implementation of mobile wind driven generator technology to produce electricity in charging of two wheeler (12V) automobile battery. The use of PWM methodology with pulse charging method at a constant rate has been adopted for this purpose. The low speed PMSG driven by wind at speed of ...

Enhanced online model identification and state of charge estimation for lithium-ion battery with a FBCRLS based observer

International Nuclear Information System (INIS)

Wei, Zhongbao; Meng, Shujuan; Xiong, Binyu; Ji, Dongxu; Tseng, King Jet

2016-01-01

Highlights: • Integrated online model identification and SOC estimate is explored. • Noise variances are online estimated in a data-driven way. • Identification bias caused by noise corruption is attenuated. • SOC is online estimated with high accuracy and fast convergence. • Algorithm comparison shows the superiority of proposed method. - Abstract: State of charge (SOC) estimators with online identified battery model have proven to have high accuracy and better robustness due to the timely adaption of time varying model parameters. In this paper, we show that the common methods for model identification are intrinsically biased if both the current and voltage sensors are corrupted with noises. The uncertainties in battery model further degrade the accuracy and robustness of SOC estimate. To address this problem, this paper proposes a novel technique which integrates the Frisch scheme based bias compensating recursive least squares (FBCRLS) with a SOC observer for enhanced model identification and SOC estimate. The proposed method online estimates the noise statistics and compensates the noise effect so that the model parameters can be extracted without bias. The SOC is further estimated in real time with the online updated and unbiased battery model. Simulation and experimental studies show that the proposed FBCRLS based observer effectively attenuates the bias on model identification caused by noise contamination and as a consequence provides more reliable estimate on SOC. The proposed method is also compared with other existing methods to highlight its superiority in terms of accuracy and convergence speed.

Modeling and analysis of LiFePO4/Carbon battery considering two-phase transition during galvanostatic charging/discharging

International Nuclear Information System (INIS)

Li, Xueyan; Xiao, Meng; Choe, Song-Yul; Joe, Won Tae

2015-01-01

Highlights: • Reduced order model for LiFePO 4 particles considering two-phase transition • Model validation with experimental results of current and voltage • Analysis of two-phase transition and path dependence - Abstract: Batteries with lithium iron phosphate (LFP) cathode and carbon anode have shown various advantages over those with other chemistries, but the plateau and path dependence caused by the two-phase transition taking place during charging and discharging make it difficult to estimate the states of battery. Thus, based on electrochemical principles we propose a new reduced order model that has been validated against experimental data obtained during galvanostatic charging/discharging. The mechanism of the two-phase transition during lithiation and delithiation in LFP particles is approximated using a shrinking corewith a moving interface between the two phases and is described by modified diffusion equations that take into account multiple layers formed within LFP particles. The shrinking core model is integrated into a cell model developed previously, which is used to analyze the path dependence at different load profiles. The results show that the model is capable of representing the characteristics of the plateau and path dependence. Particularly, the available charge at a certain State of Charge (SOC) varies dependent upon paths to reach the SOC. When an initial SOC is reached by discharging, the cell can accept more charges during charging, while when an initial SOC is reached by charging, more charge will be available during discharging

Battery Charge Affects the Stability of Light Intensity from Light-emitting Diode Light-curing Units.

Science.gov (United States)

Tongtaksin, A; Leevailoj, C

This study investigated the influence of battery charge levels on the stability of light-emitting diode (LED) curing-light intensity by measuring the intensity from fully charged through fully discharged batteries. The microhardness of resin composites polymerized by the light-curing units at various battery charge levels was measured. The light intensities of seven fully charged battery LED light-curing units-1) LY-A180, 2) Bluephase, 3) Woodpecker, 4) Demi Plus, 5) Saab II, 6) Elipar S10, and 7) MiniLED-were measured with a radiometer (Kerr) after every 10 uses (20 seconds per use) until the battery was discharged. Ten 2-mm-thick cylindrical specimens of A3 shade nanofilled resin composite (PREMISE, Kerr) were prepared per LED light-curing unit group. Each specimen was irradiated by the fully charged light-curing unit for 20 seconds. The LED light-curing units were then used until the battery charge fell to 50%. Specimens were prepared again as described above. This was repeated again when the light-curing units' battery charge fell to 25% and when the light intensity had decreased to 400 mW/cm 2 . The top/bottom surface Knoop hardness ratios of the specimens were determined. The microhardness data were analyzed by one-way analysis of variance with Tukey test at a significance level of 0.05. The Pearson correlation coefficient was used to determine significant correlations between surface hardness and light intensity. We found that the light intensities of the Bluephase, Demi Plus, and Elipar S10 units were stable. The intensity of the MiniLED unit decreased slightly; however, it remained above 400 mW/cm 2 . In contrast, the intensities of the LY-A180, Woodpecker, and Saab II units decreased below 400 mW/cm 2 . There was also a significant decrease in the surface microhardnesses of the resin composite specimens treated with MiniLED, LY-A180, Woodpecker, and Saab II. In conclusion, the light intensity of several LED light-curing units decreased as the battery was

Online Identification with Reliability Criterion and State of Charge Estimation Based on a Fuzzy Adaptive Extended Kalman Filter for Lithium-Ion Batteries

Directory of Open Access Journals (Sweden)

Zhongwei Deng

2016-06-01

Full Text Available In the field of state of charge (SOC estimation, the Kalman filter has been widely used for many years, although its performance strongly depends on the accuracy of the battery model as well as the noise covariance. The Kalman gain determines the confidence coefficient of the battery model by adjusting the weight of open circuit voltage (OCV correction, and has a strong correlation with the measurement noise covariance (R. In this paper, the online identification method is applied to acquire the real model parameters under different operation conditions. A criterion based on the OCV error is proposed to evaluate the reliability of online parameters. Besides, the equivalent circuit model produces an intrinsic model error which is dependent on the load current, and the property that a high battery current or a large current change induces a large model error can be observed. Based on the above prior knowledge, a fuzzy model is established to compensate the model error through updating R. Combining the positive strategy (i.e., online identification and negative strategy (i.e., fuzzy model, a more reliable and robust SOC estimation algorithm is proposed. The experiment results verify the proposed reliability criterion and SOC estimation method under various conditions for LiFePO4 batteries.

A Hydrogen-Evolving Hybrid-Electrolyte Battery with Electrochemical/Photoelectrochemical Charging from Water Oxidation.

Science.gov (United States)

Jin, Zhaoyu; Li, Panpan; Xiao, Dan

2017-02-08

Decoupled hydrogen and oxygen production were successfully embedded into an aqueous dual-electrolyte (acid-base) battery for simultaneous energy storage and conversion. A three-electrode configuration was adopted, involving an electrocatalytic hydrogen-evolving electrode as cathode, an alkaline battery-type or capacitor-type anode as shuttle, and a charging-assisting electrode for electro-/photoelectrochemically catalyzing water oxidation. The conceptual battery not only synergistically outputs electricity and chemical fuels with tremendous specific energy and power densities, but also supports various approaches to be charged by pure or solar-assisted electricity. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Discrete wavelet transform-based denoising technique for advanced state-of-charge estimator of a lithium-ion battery in electric vehicles

International Nuclear Information System (INIS)

Lee, Seongjun; Kim, Jonghoon

2015-01-01

Sophisticated data of the experimental DCV (discharging/charging voltage) of a lithium-ion battery is required for high-accuracy SOC (state-of-charge) estimation algorithms based on the state-space ECM (electrical circuit model) in BMSs (battery management systems). However, when sensing noisy DCV signals, erroneous SOC estimation (which results in low BMS performance) is inevitable. Therefore, this manuscript describes the design and implementation of a DWT (discrete wavelet transform)-based denoising technique for DCV signals. The steps for denoising a noisy DCV measurement in the proposed approach are as follows. First, using MRA (multi-resolution analysis), the noise-riding DCV signal is decomposed into different frequency sub-bands (low- and high-frequency components, A n and D n ). Specifically, signal processing of the high frequency component D n that focuses on a short-time interval is necessary to reduce noise in the DCV measurement. Second, a hard-thresholding-based denoising rule is applied to adjust the wavelet coefficients of the DWT to achieve a clear separation between the signal and the noise. Third, the desired de-noised DCV signal is reconstructed by taking the IDWT (inverse discrete wavelet transform) of the filtered detailed coefficients. Finally, this signal is sent to the ECM-based SOC estimation algorithm using an EKF (extended Kalman filter). Experimental results indicate the robustness of the proposed approach for reliable SOC estimation. - Highlights: • Sophisticated data of the experimental DCV is required for high-accuracy SOC. • DWT (discrete wavelet transform)-based denoising technique is newly investigated. • Three steps for denoising a noisy DCV measurement in this work are implemented. • Experimental results indicate the robustness of the proposed work for reliable SOC

A High-Gain Reflex-Based Bidirectional DC Charger with Efficient Energy Recycling for Low-Voltage Battery Charging-Discharging Power Control

Directory of Open Access Journals (Sweden)

Ching-Ming Lai

2018-03-01

Full Text Available This study proposes a high-gain reflex-charging-based bidirectional DC charger (RC-BDC to enhance the battery charging efficiency of light electric vehicles (LEV in a DC-microgrid. The proposed charger topology consists of an unregulated level converter (ULC and a two-phase interleaved buck-boost charge-pump converter (IBCPC, which together provide low ripple and high voltage conversion ratio. As the high-gain RC-BDC charges, the LEV’s battery with reflex charging currents, high battery charging efficiency, and prolonged battery life cycles are achieved. This is possible due to the recovering of negative pulse energy of reflex charging currents to reduce charge dissipations within LEV’s batteries. Derivations of the operating principles of the high-gain RC-BDC, analyses of its topology, and the closed-loop control designs were presented. Simulations and experiments were implemented with battery voltage of 48 V and DC-bus voltage of 400 V for a 500 W prototype. The results verify the feasibility of the proposed concept and were compared with the typical constant-current/constant-voltage (CC/CV charger. The comparison shows that the proposed high gain RC-BDC improves battery charging speed and reduces the battery thermal deterioration effect by about 12.7% and 25%, respectively.

A Battery Power Bank with Series-Connected Buck–Boost-Type Battery Power Modules

Directory of Open Access Journals (Sweden)

Tsung-Hsi Wu

2017-05-01

Full Text Available The operation of a battery power bank with series-connected buck–boost-type battery power modules (BPMs was investigated in this study. Each BPM consisted of a battery pack with an associated buck–boost converter for individually controlling battery currents. With a proposed discharging scenario, load voltage regulation with charge equalization among batteries was performed by controlling the battery currents in accordance with their state-of-charges (SOCs estimated by real-time battery-loaded voltages detected under the same operating condition. In addition, the fault tolerance was executed to isolate exhausted or faulty batteries from the battery power bank without interrupting the system operation. Experiments were conducted to verify the effectiveness of the discharging scenario for a laboratory battery power bank with four series buck–boost BPMs.

Polyoxometalate active charge-transfer material for mediated redox flow battery

Energy Technology Data Exchange (ETDEWEB)

Anderson, Travis Mark; Hudak, Nicholas; Staiger, Chad; Pratt, Harry

2017-01-17

Redox flow batteries including a half-cell electrode chamber coupled to a current collecting electrode are disclosed herein. In a general embodiment, a separator is coupled to the half-cell electrode chamber. The half-cell electrode chamber comprises a first redox-active mediator and a second redox-active mediator. The first redox-active mediator and the second redox-active mediator are circulated through the half-cell electrode chamber into an external container. The container includes an active charge-transfer material. The active charge-transfer material has a redox potential between a redox potential of the first redox-active mediator and a redox potential of the second redox-active mediator. The active charge-transfer material is a polyoxometalate or derivative thereof. The redox flow battery may be particularly useful in energy storage solutions for renewable energy sources and for providing sustained power to an electrical grid.

Electric vehicle battery charging algorithm using PMSM windings and an inverter as an active rectifier

DEFF Research Database (Denmark)

Zaja, Mario; Oprea, Matei-lon; Suárez, Carlos Gómez

2014-01-01

for battery charging. Alternatively, charging could be done using the motor windings as grid side inductors and controlling the inverter to operate as an active boost rectifier. The challenge in this approach is the unequal phase inductances which depend on the rotor position. Another problem appears when...... an integrated charger control algorithm to charge the battery through a permanent magnet synchronous machine (PMSM) windings....

Cyclic steady states in diffusion-induced plasticity with applications to lithium-ion batteries

Science.gov (United States)

Peigney, Michaël

2018-02-01

Electrode materials in lithium-ion batteries offer an example of medium in which stress and plastic flow are generated by the diffusion of guest atoms. In such a medium, deformation and diffusion are strongly coupled processes. For designing electrodes with improved lifetime and electro-mechanical efficiency, it is crucial to understand how plasticity and diffusion evolve over consecutive charging-recharging cycles. With such questions in mind, this paper provides general results for the large-time behavior of media coupling plasticity with diffusion when submitted to cyclic chemo-mechanical loadings. Under suitable assumptions, we show that the stress, the plastic strain rate, the chemical potential and the flux of guest atoms converge to a cyclic steady state which is largely independent of the initial state. A special emphasis is laid on the special case of elastic shakedown, which corresponds to the situation where the plastic strain stops evolving after a sufficiently large number of cycles. Elastic shakedown is expected to be beneficial for the fatigue behavior and - in the case of lithium-ion batteries - for the electro-chemical efficiency. We provide a characterization of the chemo-mechanical loadings for which elastic shakedown occurs. Building on that characterization, we suggest a general method for designing structures in such fashion that they operate in the elastic shakedown regime, whatever the initial state is. An attractive feature of the proposed method is that incremental analysis of the fully coupled plasticity-diffusion problem is avoided. The results obtained are applied to the model problem of a battery electrode cylinder particle under cyclic charging. Closed-form expressions are obtained for the set of charging rates and charging amplitudes for which elastic shakedown occurs, as well as for the corresponding cyclic steady states of stress, lithium concentration and chemical potential. Some results for a spherical particle are also presented.

Integrating a redox-coupled dye-sensitized photoelectrode into a lithium-oxygen battery for photoassisted charging.

Science.gov (United States)

Yu, Mingzhe; Ren, Xiaodi; Ma, Lu; Wu, Yiying

2014-10-03

With a high theoretical specific energy, the non-aqueous rechargeable lithium-oxygen battery is a promising next-generation energy storage technique. However, the large charging overpotential remains a challenge due to the difficulty in electrochemically oxidizing the insulating lithium peroxide. Recently, a redox shuttle has been introduced into the electrolyte to chemically oxidize lithium peroxide. Here, we report the use of a triiodide/iodide redox shuttle to couple a built-in dye-sensitized titanium dioxide photoelectrode with the oxygen electrode for the photoassisted charging of a lithium-oxygen battery. On charging under illumination, triiodide ions are generated on the photoelectrode, and subsequently oxidize lithium peroxide. Due to the contribution of the photovoltage, the charging overpotential is greatly reduced. The use of a redox shuttle to couple a photoelectrode and an oxygen electrode offers a unique strategy to address the overpotential issue of non-aqueous lithium-oxygen batteries and also a distinct approach for integrating solar cells and batteries.

Battery Management Systems in Electric and Hybrid Vehicles

Directory of Open Access Journals (Sweden)

Michael Pecht

2011-10-01

Full Text Available The battery management system (BMS is a critical component of electric and hybrid electric vehicles. The purpose of the BMS is to guarantee safe and reliable battery operation. To maintain the safety and reliability of the battery, state monitoring and evaluation, charge control, and cell balancing are functionalities that have been implemented in BMS. As an electrochemical product, a battery acts differently under different operational and environmental conditions. The uncertainty of a battery’s performance poses a challenge to the implementation of these functions. This paper addresses concerns for current BMSs. State evaluation of a battery, including state of charge, state of health, and state of life, is a critical task for a BMS. Through reviewing the latest methodologies for the state evaluation of batteries, the future challenges for BMSs are presented and possible solutions are proposed as well.

Study on the Optimal Charging Strategy for Lithium-Ion Batteries Used in Electric Vehicles

Directory of Open Access Journals (Sweden)

Shuo Zhang

2014-10-01

Full Text Available The charging method of lithium-ion batteries used in electric vehicles (EVs significantly affects its commercial application. This paper aims to make three contributions to the existing literature. (1 In order to achieve an efficient charging strategy for lithium-ion batteries with shorter charging time and lower charring loss, the trade-off problem between charging loss and charging time has been analyzed in details through the dynamic programing (DP optimization algorithm; (2 To reduce the computation time consumed during the optimization process, we have proposed a database based optimization approach. After off-line calculation, the simulation results can be applied to on-line charge; (3 The novel database-based DP method is proposed and the simulation results illustrate that this method can effectively find the suboptimal charging strategies under a certain balance between the charging loss and charging time.

Energy efficiency and capacity retention of Ni–MH batteries for storage applications

International Nuclear Information System (INIS)

Zhu, Wenhua H.; Zhu, Ying; Davis, Zenda; Tatarchuk, Bruce J.

2013-01-01

Highlights: ► Ni–MH battery energy efficiency was evaluated at full and partial state-of-charge. ► State-of-charge and state-of-recharge were studied by voltage changes and capacity measurement. ► Capacity retention of the NiMH-B2 battery was 70% after fully charge and 1519 h of storage. ► The inefficient charge process started at ca. 90% of rated capacity when charged at ⩽0.2 C rate. ► Battery durability and low self-discharge strategies are analyzed and discussed for energy storage needs. - Abstract: The Ni–MH batteries were tested for battery energy storage characteristics, including the effects of battery charge or discharge at different rates. The battery energy efficiency and capacity retention were evaluated through measuring the charge/discharge capacities and energies during full and partial state-of-charge (SoC) operations. Energy efficiency results were obtained at various charge input levels and different charge and discharge rates. The inefficient charging process started to take place at ca. 90% state-of-recharge (SoR) when charged at no more than 0.2 C rate. For the NiMH-B2 battery after an approximately full charge (∼100% SoC at 120% SoR and a 0.2 C charge/discharge rate), the capacity retention was obtained as 83% after 360 h of storage, and 70% after 1519 h of storage. The energy efficiency was decreased from 74.0% to 50% after 1519 h of storage time. The Coulomb efficiency was initially 83.34%, and was reduced to 57.95% after 1519 h of storage. The battery has relatively higher energy efficiency at approximately 50% SoC. The energy efficiency was calculated to be more than 92% when the NiMH-C3 battery was charged to 30–70% SoC then discharged to 0% SoC at a 0.2 C charge/discharge rate. In consideration of energy efficiency, charge acceptance, capacity retention rate, and power output needs, as well as Nelson’s analysis on HEV power requirements, the Ni–MH battery is appropriate to work at ca. 50 ± 10% SoC with an

On-line parameter, state-of-charge and aging estimation of Li-ion batteries

NARCIS (Netherlands)

Rosca, B.; Kessels, J.T.B.A.; Bergveld, H.J.; Bosch, P.P.J. van den

2012-01-01

This paper presents an on-line model identification method for Li-ion battery parameters that combines high accuracy and low computational complexity. Experimental results show that modeling errors are smaller than 1% throughout the feasible operating range. The identified model is used in a state

Organic hydrogen peroxide-driven low charge potentials for high-performance lithium-oxygen batteries with carbon cathodes

Science.gov (United States)

Wu, Shichao; Qiao, Yu; Yang, Sixie; Ishida, Masayoshi; He, Ping; Zhou, Haoshen

2017-06-01

Reducing the high charge potential is a crucial concern in advancing the performance of lithium-oxygen batteries. Here, for water-containing lithium-oxygen batteries with lithium hydroxide products, we find that a hydrogen peroxide aqueous solution added in the electrolyte can effectively promote the decomposition of lithium hydroxide compounds at the ultralow charge potential on a catalyst-free Ketjen Black-based cathode. Furthermore, for non-aqueous lithium-oxygen batteries with lithium peroxide products, we introduce a urea hydrogen peroxide, chelating hydrogen peroxide without any water in the organic, as an electrolyte additive in lithium-oxygen batteries with a lithium metal anode and succeed in the realization of the low charge potential of ~3.26 V, which is among the best levels reported. In addition, the undesired water generally accompanying hydrogen peroxide solutions is circumvented to protect the lithium metal anode and ensure good battery cycling stability. Our results should provide illuminating insights into approaches to enhancing lithium-oxygen batteries.

Control Algorithms Charge Batteries Faster

Science.gov (United States)

2012-01-01

On March 29, 2011, NASA s Mercury Surface, Space Environment, Geochemistry and Ranging (MESSENGER) spacecraft beamed a milestone image to Earth: the first photo of Mercury taken from orbit around the solar system s innermost planet. (MESSENGER is also the first spacecraft to orbit Mercury.) Like most of NASA s deep space probes, MESSENGER is enabled by a complex power system that allows its science instruments and communications to function continuously as it travels millions of miles from Earth. "Typically, there isn't one particular power source that can support the entire mission," says Linda Taylor, electrical engineer in Glenn Research Center s Power Systems Analysis Branch. "If you have solar arrays and you are in orbit, at some point you re going to be in eclipse." Because of this, Taylor explains, spacecraft like MESSENGER feature hybrid power systems. MESSENGER is powered by a two-panel solar array coupled with a nickel hydrogen battery. The solar arrays provide energy to the probe and charge the battery; when the spacecraft s orbit carries it behind Mercury and out of the Sun s light, the spacecraft switches to battery power to continue operations. Typically, hybrid systems with multiple power inputs and a battery acting alternately as storage and a power source require multiple converters to handle the power flow between the devices, Taylor says. (Power converters change the qualities of electrical energy, such as from alternating current to direct current, or between different levels of voltage or frequency.) This contributes to a pair of major concerns for spacecraft design. "Weight and size are big drivers for any space application," Taylor says, noting that every pound added to a space vehicle incurs significant costs. For an innovative solution to managing power flows in a lightweight, cost-effective manner, NASA turned to a private industry partner.

Electrolyte additive enabled fast charging and stable cycling lithium metal batteries

Energy Technology Data Exchange (ETDEWEB)

Zheng, Jianming; Engelhard, Mark H.; Mei, Donghai; Jiao, Shuhong; Polzin, Bryant J.; Zhang, Ji-Guang; Xu, Wu

2017-03-01

Lithium (Li) metal battery is an attractive energy storage system owing to the ultrahigh specific capacity and the lowest redox potential of Li metal anode. However, safety concern associated with dendrite growth and limited cycle life especially at a high charge current density are two critical challenges hindering the practical applications of rechargeable Li metal batteries. Here, we report for the first time that an optimal amount (0.05 M) of LiPF6 as additive in the LiTFSI-LiBOB dual-salt/carbonate-based electrolyte can significantly enhance the charging capability and the long-term cycle life of Li metal batteries with a moderately high cathode loading of 1.75 mAh cm-2. Unprecedented stable-cycling (97.1% capacity retention after 500 cycles) along with very limited increase in electrode over-potential has been achieved at a high current density of 1.75 mA cm-2. This unparalleled fast charging and stable cycling performance is contributed from both the stabilized Al cathode current collector, and, more importantly, the robust and conductive SEI layer formed on Li metal anode in the presence of the LiPF6 additive.

A brief review on key technologies in the battery management system of electric vehicles

Science.gov (United States)

Liu, Kailong; Li, Kang; Peng, Qiao; Zhang, Cheng

2018-04-01

Batteries have been widely applied in many high-power applications, such as electric vehicles (EVs) and hybrid electric vehicles, where a suitable battery management system (BMS) is vital in ensuring safe and reliable operation of batteries. This paper aims to give a brief review on several key technologies of BMS, including battery modelling, state estimation and battery charging. First, popular battery types used in EVs are surveyed, followed by the introduction of key technologies used in BMS. Various battery models, including the electric model, thermal model and coupled electro-thermal model are reviewed. Then, battery state estimations for the state of charge, state of health and internal temperature are comprehensively surveyed. Finally, several key and traditional battery charging approaches with associated optimization methods are discussed.

All-solid-state lithium-sulfur battery based on a nanoconfined LiBH4 electrolyte

DEFF Research Database (Denmark)

Das, Supti; Ngene, Peter; Norby, Poul

2016-01-01

In this work we characterize all-solid-state lithium-sulfur batteries based on nano-confined LiBH4 in mesoporous silica as solid electrolytes. The nano-confined LiBH4 has fast ionic lithium conductivity at room temperature, 0.1 mScm-1, negligible electronic conductivity and its cationic transport...... number (t+ = 0.96), close to unity, demonstrates a purely cationic conductor. The electrolyte has an excellent stability against lithium metal. The behavior of the batteries is studied by cyclic voltammetry and repeated charge/discharge cycles in galvanostatic conditions. The batteries show very good...

Computational models of an inductive power transfer system for electric vehicle battery charge

Science.gov (United States)

Anele, A. O.; Hamam, Y.; Chassagne, L.; Linares, J.; Alayli, Y.; Djouani, K.

2015-09-01

One of the issues to be solved for electric vehicles (EVs) to become a success is the technical solution of its charging system. In this paper, computational models of an inductive power transfer (IPT) system for EV battery charge are presented. Based on the fundamental principles behind IPT systems, 3 kW single phase and 22 kW three phase IPT systems for Renault ZOE are designed in MATLAB/Simulink. The results obtained based on the technical specifications of the lithium-ion battery and charger type of Renault ZOE show that the models are able to provide the total voltage required by the battery. Also, considering the charging time for each IPT model, they are capable of delivering the electricity needed to power the ZOE. In conclusion, this study shows that the designed computational IPT models may be employed as a support structure needed to effectively power any viable EV.

Computational models of an inductive power transfer system for electric vehicle battery charge

International Nuclear Information System (INIS)

Anele, A O; Hamam, Y; Djouani, K; Chassagne, L; Alayli, Y; Linares, J

2015-01-01

One of the issues to be solved for electric vehicles (EVs) to become a success is the technical solution of its charging system. In this paper, computational models of an inductive power transfer (IPT) system for EV battery charge are presented. Based on the fundamental principles behind IPT systems, 3 kW single phase and 22 kW three phase IPT systems for Renault ZOE are designed in MATLAB/Simulink. The results obtained based on the technical specifications of the lithium-ion battery and charger type of Renault ZOE show that the models are able to provide the total voltage required by the battery. Also, considering the charging time for each IPT model, they are capable of delivering the electricity needed to power the ZOE. In conclusion, this study shows that the designed computational IPT models may be employed as a support structure needed to effectively power any viable EV. (paper)

Adiabatic and Nonadiabatic Charge Transport in Li-S Batteries

DEFF Research Database (Denmark)

Park, Haesun; Kumar, Nitin; Melander, Marko

2018-01-01

The insulating nature of the redox end members in Li-S batteries, -S and Li2S, has the potential to limit the capacity and efficiency of this emerging energy storage system. Nevertheless, the mechanisms responsible for ionic and electronic transport in these materials remain a matter of debate...... studies, we conclude that low equilibrium carrier concentrations are responsible for sluggish charge transport in -S and Li2S. Thus, a potential strategy for improving the performance of Li-S batteries is to increase the concentrations of holes in these redox end members....

Novel Energy Sources -Material Architecture and Charge Transport in Solid State Ionic Materials for Rechargeable Li ion Batteries

Energy Technology Data Exchange (ETDEWEB)

Katiyar, Ram S; Gómez, M; Majumder, S B; Morell, G; Tomar, M S; Smotkin, E; Bhattacharya, P; Ishikawa, Y

2009-01-19

Since its introduction in the consumer market at the beginning of 1990s by Sony Corporation ‘Li-ion rechargeable battery’ and ‘LiCoO2 cathode’ is an inseparable couple for highly reliable practical applications. However, a separation is inevitable as Li-ion rechargeable battery industry demand more and more from this well serving cathode. Spinel-type lithium manganate (e.g., LiMn2O4), lithium-based layered oxide materials (e.g., LiNiO2) and lithium-based olivine-type compounds (e.g., LiFePO4) are nowadays being extensively studied for application as alternate cathode materials in Li-ion rechargeable batteries. Primary goal of this project was the advancement of Li-ion rechargeable battery to meet the future demands of the energy sector. Major part of the research emphasized on the investigation of electrodes and solid electrolyte materials for improving the charge transport properties in Li-ion rechargeable batteries. Theoretical computational methods were used to select electrodes and electrolyte material with enhanced structural and physical properties. The effect of nano-particles on enhancing the battery performance was also examined. Satisfactory progress has been made in the bulk form and our efforts on realizing micro-battery based on thin films is close to give dividend and work is progressing well in this direction.

Performance Modeling of a Vanadium Redox Flow Battery during Discharging

International Nuclear Information System (INIS)

Yang, W.W.; He, Y.L.; Li, Y.S.

2015-01-01

A two-dimensional quasi-steady-state model is presented to simulate coupled mass-species-charge transfer and electrochemical reactions in all vanadium redox flow battery. Emphasis is located on examining the influences of applied current density, initial vanadium concentration, initial acid concentration and electrolyte flow rate on overpotentials in both electrodes, ohmic loss in electrolyte phase as well as battery discharging voltage. It is indicated that overpotential in negative electrode is the dominant factor causing the loss of battery discharging voltage at relatively lower or higher state of charge, while ohmic loss in electrolyte phase is dominant when discharging at moderate state of charge. Increasing initial vanadium concentration, the battery discharging voltage is significantly increased due to the reduced overpotentials in both electrodes. With the increase in initial acid concentration, the battery discharging voltage is also obviously increased because of increased open circuit voltage and decreased ohmic loss in electrolyte phase. As the electrolyte flow rate increases, the total discharging time is extended due to the retarded concentration polarization and the battery discharging voltage is obviously increased at lower state of charge

Charge retention test experiences on Hubble Space Telescope nickel-hydrogen battery cells

Science.gov (United States)

Nawrocki, Dave E.; Driscoll, J. R.; Armantrout, J. D.; Baker, R. C.; Wajsgras, H.

1993-01-01

The Hubble Space Telescope (HST) nickel-hydrogen battery module was designed by Lockheed Missile & Space Co (LMSC) and manufactured by Eagle-Picher Ind. (EPI) for the Marshall Space Flight Center (MSFC) as an Orbital Replacement Unit (ORU) for the nickel-cadmium batteries originally selected for this low earth orbit mission. The design features of the HST nickel hydrogen battery are described and the results of an extended charge retention test are summarized.

Functional Two-Dimensional Coordination Polymeric Layer as a Charge Barrier in Li–S Batteries

KAUST Repository

Huang, Jing-Kai

2018-01-04

Ultrathin two-dimensional (2D) polymeric layers are capable of separating gases and molecules based on the reported size exclusion mechanism. What is equally important but missing today is an exploration of the 2D layers with charge functionality, which enables applications using the charge exclusion principle. This work demonstrates a simple and scalable method of synthesizing a free-standing 2D coordination polymer Zn2(benzimidazolate)2(OH)2 at the air–water interface. The hydroxyl (−OH) groups are stoichiometrically coordinated and implement electrostatic charges in the 2D structures, providing powerful functionality as a charge barrier. Electrochemical performance of the Li–S battery shows that the Zn2(benzimidazolate)2(OH)2 coordination polymer layers efficiently mitigate the polysulfide shuttling effects and largely enhance the battery capacity and cycle performance. The synthesis of the proposed coordination polymeric layers is simple, scalable, cost saving, and promising for practical use in batteries.

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

Science.gov (United States)

Badawy, Mohamed O.

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

A PSO-Optimized Fuzzy Logic Control-Based Charging Method for Individual Household Battery Storage Systems within a Community

Directory of Open Access Journals (Sweden)

Yu-Shan Cheng

2018-02-01

Full Text Available Self-consumption of household photovoltaic (PV storage systems has become profitable for residential owners under the trends of limited feed-in power and decreasing PV feed-in tariffs. For individual PV-storage systems, the challenge mainly lies in managing surplus generation of battery and grid power flow, ideally without relying on error-prone forecasts for both generation and consumption. Considering the large variation in power profiles of different houses in a neighborhood, the strategy is also supposed to be beneficial and applicable for the entire community. In this study, an adaptable battery charging control strategy is designed in order to obtain minimum costs for houses without any meteorological or load forecasts. Based on fuzzy logic control (FLC, battery state-of-charge (SOC and the variation of SOC (∆SOC are taken as input variables to dynamically determine output charging power with minimum costs. The proposed FLC-based algorithm benefits from the charging battery as much as possible during the daytime, and meanwhile properly preserves the capacity at midday when there is high possibility of curtailment loss. In addition, due to distinct power profiles in each individual house, input membership functions of FLC are improved by particle swarm optimization (PSO to achieve better overall performance. A neighborhood with 74 houses in Germany is set up as a scenario for comparison to prior studies. Without forecasts of generation and consumption power, the proposed method leads to minimum costs in 98.6% of houses in the community, and attains the lowest average expenses for a single house each year.

A Novel Observer for Lithium-Ion Battery State of Charge Estimation in Electric Vehicles Based on a Second-Order Equivalent Circuit Model

Directory of Open Access Journals (Sweden)

Bizhong Xia

2017-08-01

Full Text Available Accurate state of charge (SOC estimation can prolong lithium-ion battery life and improve its performance in practice. This paper proposes a new method for SOC estimation. The second-order resistor-capacitor (2RC equivalent circuit model (ECM is applied to describe the dynamic behavior of lithium-ion battery on deriving state space equations. A novel method for SOC estimation is then presented. This method does not require any matrix calculation, so the computation cost can be very low, making it more suitable for hardware implementation. The Federal Urban Driving Schedule (FUDS, The New European Driving Cycle (NEDC, and the West Virginia Suburban Driving Schedule (WVUSUB experiments are carried to evaluate the performance of the proposed method. Experimental results show that the SOC estimation error can converge to 3% error boundary within 30 seconds when the initial SOC estimation error is 20%, and the proposed method can maintain an estimation error less than 3% with 1% voltage noise and 5% current noise. Further, the proposed method has excellent robustness against parameter disturbance. Also, it has higher estimation accuracy than the extended Kalman filter (EKF, but with decreased hardware requirements and faster convergence rate.

Online Estimation of Model Parameters and State of Charge of LiFePO4 Batteries Using a Novel Open-Circuit Voltage at Various Ambient Temperatures

Directory of Open Access Journals (Sweden)

Fei Feng

2015-04-01

Full Text Available This study describes an online estimation of the model parameters and state of charge (SOC of lithium iron phosphate batteries in electric vehicles. A widely used SOC estimator is based on the dynamic battery model with predeterminate parameters. However, model parameter variances that follow with their varied operation temperatures can result in errors in estimating battery SOC. To address this problem, a battery online parameter estimator is presented based on an equivalent circuit model using an adaptive joint extended Kalman filter algorithm. Simulations based on actual data are established to verify accuracy and stability in the regression of model parameters. Experiments are also performed to prove that the proposed estimator exhibits good reliability and adaptability under different loading profiles with various temperatures. In addition, open-circuit voltage (OCV is used to estimate SOC in the proposed algorithm. However, the OCV based on the proposed online identification includes a part of concentration polarization and hysteresis, which is defined as parametric identification-based OCV (OCVPI. Considering the temperature factor, a novel OCV–SOC relationship map is established by using OCVPI under various temperatures. Finally, a validating experiment is conducted based on the consecutive loading profiles. Results indicate that our method is effective and adaptable when a battery operates at different ambient temperatures.

An improved charging/discharging strategy of lithium batteries considering depreciation cost in day-ahead microgrid scheduling

International Nuclear Information System (INIS)

Zhang, Zhong; Wang, Jianxue; Wang, Xiuli

2015-01-01

Highlights: • A quantitative depreciation cost model is put forward for lithium batteries. • A practical charging/discharging strategy is applied to battery management. • The depth of discharge of the battery storage is scheduled more rationally. • The proposed strategy improves the cost efficiency of lithium batteries in MGs. - Abstract: An energy storage system is critical for the safe and stable operation of a microgrid (MG) and has a promising prospect in future power system. Economical and safe operation of storage system is of great significance to MGs. This paper presents an improved management strategy for lithium battery storage by establishing a battery depreciation cost model and employing a practical charging/discharging strategy. Firstly, experimental data of lithium battery cycle lives, which are functions of the depth of discharge, are investigated and synthesized. A quantitative depreciation cost model is put forward for lithium batteries from the perspective of cycle life. Secondly, a practical charging/discharging strategy is applied to the lithium battery management in MGs. Then, an optimal scheduling model is developed to minimize MG operational cost including battery depreciation cost. Finally, numerical tests are conducted on a typical grid-connected MG. Results show that the depth of discharge of storage is scheduled more rationally, and operational cost is simultaneously saved for MG under the proposed management strategy. This study helps to improve the cost efficiency and alleviate the aging process for lithium batteries.

A novel ultrasonic velocity sensing approach to monitoring state of charge of vanadium redox flow battery

International Nuclear Information System (INIS)

Chou, Yi-Sin; Hsu, Ning-Yih; Jeng, King-Tsai; Chen, Kuan-Hsiang; Yen, Shi-Chern

2016-01-01

Highlights: • This is the first to apply ultrasonic sensing technique to monitor SOC of VRB. • Ultrasound velocity is affected by concentration and temperature of a solution. • The ultrasonic sensing is applicable to both positive and negative sides of VRB. • An empirical model equation fits the results of this two-component system well. • The SOC of a VRB can be properly measured using ultrasonic sensing. - Abstract: A novel ultrasonic velocity sensing approach is proposed and investigated to monitor the state of charge (SOC) of a vanadium redox flow battery (VRB, or VRFB). The positive electrode is designated as the energy storage capacity-limiting one so that the molar ratio of the V"5"+ ion in the positive electrolyte solution determines the SOC of a VRB. The tested single-cell VRB is connected to an ultrasonic sensor and charged/discharged almost to its two extremes at a constant current of 2 A under various operating temperatures. It is found that the ultrasound velocity exhibits distinct variations in accordance with changes of vanadium ion compositions in the positive electrolyte solution as the SOC of the VRB varies. The SOC obtained can be depicted in a 3D plot in terms of ultrasound velocity and operating temperature. An empirical model equation is proposed and found to fit the experimental results of both charging and discharging stages quite well. The advantages of this SOC sensing approach are that it is totally independent of VRB operations and can be readily applied to both sides of the electrodes. It is expected to develop into a dependable method for accurate and real-time monitoring of SOC for VRB.

State of charge estimation of lithium-ion batteries using the open-circuit voltage at various ambient temperatures

International Nuclear Information System (INIS)

Xing, Yinjiao; He, Wei; Pecht, Michael; Tsui, Kwok Leung

2014-01-01

Highlights: • An offline OCV–SOC–temperature table was established to infer battery SOC. • A temperature-based model was developed to estimate SOC at different temperatures. • The algorithm for SOC estimation was verified by dynamic current load. • The robustness of the approach was validated by different initial SOC values. - Abstract: Ambient temperature is a significant factor that influences the accuracy of battery SOC estimation, which is critical for remaining driving range prediction of electric vehicles (EVs) and optimal charge/discharge control of batteries. A widely used method to estimate SOC is based on an online inference of open-circuit voltage (OCV). However, the fact that the OCV–SOC is dependent on ambient temperature can result in errors in battery SOC estimation. To address this problem, this paper presents an SOC estimation approach based on a temperature-based model incorporated with an OCV–SOC–temperature table. The unscented Kalman filtering (UKF) was applied to tune the model parameters at each sampling step to cope with various uncertainties arising from the operation environment, cell-to-cell variation, and modeling inaccuracy. Two dynamic tests, the dynamic stress test (DST) and the federal urban driving schedule (FUDS), were used to test batteries at different temperatures. Then, DST was used to identify the model parameters while FUDS was used to validate the performance of the SOC estimation. The estimation was made covering the major working range from 25% to 85% SOC. The results indicated that our method can provide accurate SOC estimation with smaller root mean squared errors than the method that does not take into account ambient temperature. Thus, our approach is effective and accurate when battery operates at different ambient temperatures. Since the developed method takes into account the temperature factor as well as the complexity of the model, it could be effectively applied in battery management systems for

A Novel Electric Bicycle Battery Monitoring System Based on Android Client

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Chuanxue Song

2017-01-01

Full Text Available The battery monitoring system (BMS plays a crucial role in maintaining the safe operation of the lithium battery electric bicycle and prolonging the life of the battery pack. This paper designed a set of new battery monitoring systems based on the Android system and ARM single-chip microcomputer to enable direct management of the lithium battery pack and convenient monitoring of the state of the battery pack. The BMS realizes the goal of monitoring the voltage, current, and ambient temperature of lithium batteries, estimating the state of charge (SOC and state of health (SOH, protecting the battery from abuse during charging or discharging, and ensuring the consistency of the batteries by integrating the passive equalization circuit. The BMS was proven effective and feasible through several tests, including charging/discharging, estimation accuracy, and communication tests. The results indicated that the BMS could be used in the design and application of the electric bicycle.

q-deformed charged fermion coherent states and SU(3) charged, Hyper-charged fermion coherent states

International Nuclear Information System (INIS)

Hao Sanru; Li Guanghua; Long Junyan

1994-01-01

By virtue of the algebra of the q-deformed fermion oscillators, the q-deformed charged fermion coherent states and SU(3) charged, hyper-charged fermion coherent states are discussed. The explicit forms of the two kinds of coherent states mentioned above are obtained by making use of the completeness of base vectors in the q-fermion Fock space. By comparing the q-deformed results with the ordinary results, it is found that the q-deformed charged fermion coherent states and SU(3) charged, hyper-charged fermion coherent states are automatically reduced to the ordinary charged fermion coherent states and SU(3) charged hyper-charged fermion coherent states if the deformed parameter q→1

Machine Learning Based Diagnosis of Lithium Batteries

Science.gov (United States)

Ibe-Ekeocha, Chinemerem Christopher

The depletion of the world's current petroleum reserve, coupled with the negative effects of carbon monoxide and other harmful petrochemical by-products on the environment, is the driving force behind the movement towards renewable and sustainable energy sources. Furthermore, the growing transportation sector consumes a significant portion of the total energy used in the United States. A complete electrification of this sector would require a significant development in electric vehicles (EVs) and hybrid electric vehicles (HEVs), thus translating to a reduction in the carbon footprint. As the market for EVs and HEVs grows, their battery management systems (BMS) need to be improved accordingly. The BMS is not only responsible for optimally charging and discharging the battery, but also monitoring battery's state of charge (SOC) and state of health (SOH). SOC, similar to an energy gauge, is a representation of a battery's remaining charge level as a percentage of its total possible charge at full capacity. Similarly, SOH is a measure of deterioration of a battery; thus it is a representation of the battery's age. Both SOC and SOH are not measurable, so it is important that these quantities are estimated accurately. An inaccurate estimation could not only be inconvenient for EV consumers, but also potentially detrimental to battery's performance and life. Such estimations could be implemented either online, while battery is in use, or offline when battery is at rest. This thesis presents intelligent online SOC and SOH estimation methods using machine learning tools such as artificial neural network (ANN). ANNs are a powerful generalization tool if programmed and trained effectively. Unlike other estimation strategies, the techniques used require no battery modeling or knowledge of battery internal parameters but rather uses battery's voltage, charge/discharge current, and ambient temperature measurements to accurately estimate battery's SOC and SOH. The developed

Batteries. Fundamentals and theory, present state of the art of technology and trends of developments. 5. ed.; Batterien. Grundlagen und Theorie, aktueller technischer Stand und Entwicklungstendenzen

Energy Technology Data Exchange (ETDEWEB)

Kiehne, H.A.; Berndt, D.; Fischer, W.; Franke, H.; Koenig, W.; Koethe, H.K.; Preuss, P.; Sassmannshausen, G.; Stahl, U.C.; Wehrle, E.; Will, G.; Willmes, H.

2003-07-01

This volume gives a comprehensive survey of the present state of the electrochemical power storage with special consideration of their technical characteristics of application. The volume is structured as follows: 1) Electrochemical energy storage, general fundamentals; 2) Batteries for electric-powered industrial trucks; 3) Energy supply concepts for driverless industrial trucks; 4) Batteries for electric-powered road vehicles; 5) Battery-fed electric drive from the user's point of view (=charging, maintenance); 6) Safety standards for stationary batteries and battery systems; 7) Batteries for stationary power supplies; 8) Battery operation from the user's point of view; 9) Starter batteries of vehicles; 10) High-energy batteries (e.g. Zn/Br{sub 2}-, Na/S-, Li/FeS-cells, fuel cells); 11) Solar-electric power supply with batteries; 12) Charging methods and charging technique; 13) Technology of battery chargers and current transformer, monitoring methods; 14) Standards and regulations for batteries and battery systems.

Research on SOC Calibration of Large Capacity Lead Acid Battery

Science.gov (United States)

Ye, W. Q.; Guo, Y. X.

2018-05-01

Large capacity lead-acid battery is used in track electric locomotive, and State of Charge (SOC) is an important quantitative parameter of locomotive power output and operating mileage of power emergency recovery vehicle. But State of Charge estimation has been a difficult part in the battery management system. In order to reduce the SOC estimation error better, this paper uses the linear relationship of Open Circuit Voltage (OCV) and State of Charge to fit the SOC-OCV curve equation by MATLAB. The method proposed in this paper is small, easy to implement and can be used in the battery non-working state SOC estimation correction, improve the estimation accuracy of SOC.

Effect of shrapnel penetration on lithium-carbon monofluoride and lithium-manganese dioxide batteries

Science.gov (United States)

Garrard, W. N. C.

National BR2/3A lithium-carbon monofluoride and Duracell DL2/3A lithium-manganese dioxide batteries were subjected to simulated shrapnel penetration using a projectile from an M16 rifle. Trials were conducted on batteries in various states of charge (0, 50, and 100 percent discharged) in both wet and dry environments. Only one fully charged Duracell Battery (under wet conditions) caught fire during the test. The effects of environmental conditions, the chemical reactions involved, and the state of charge of the batteries on the probability of the batteries igniting are discussed.

Effect of extreme temperatures on battery charging and performance of electric vehicles

Science.gov (United States)

Lindgren, Juuso; Lund, Peter D.

2016-10-01

Extreme temperatures pose several limitations to electric vehicle (EV) performance and charging. To investigate these effects, we combine a hybrid artificial neural network-empirical Li-ion battery model with a lumped capacitance EV thermal model to study how temperature will affect the performance of an EV fleet. We find that at -10 °C, the self-weighted mean battery charging power (SWMCP) decreases by 15% compared to standard 20 °C temperature. Active battery thermal management (BTM) during parking can improve SWMCP for individual vehicles, especially if vehicles are charged both at home and at workplace; the median SWMCP is increased by over 30%. Efficiency (km/kWh) of the vehicle fleet is maximized when ambient temperature is close to 20 °C. At low (-10 °C) and high (+40 °C) ambient temperatures, cabin preconditioning and BTM during parking can improve the median efficiency by 8% and 9%, respectively. At -10 °C, preconditioning and BTM during parking can also improve the fleet SOC by 3-6%-units, but this also introduces a ;base; load of around 140 W per vehicle. Finally, we observe that the utility of the fleet can be increased by 5%-units by adding 3.6 kW chargers to workplaces, but further improved charging infrastructure would bring little additional benefit.

The Shortest Path Problems in Battery-Electric Vehicle Dispatching with Battery Renewal

Directory of Open Access Journals (Sweden)

Minfang Huang

2016-06-01

Full Text Available Electric vehicles play a key role for developing an eco-sustainable transport system. One critical component of an electric vehicle is its battery, which can be quickly charged or exchanged before it runs out. The problem of electric vehicle dispatching falls into the category of the shortest path problem with resource renewal. In this paper, we study the shortest path problems in (1 electric transit bus scheduling and (2 electric truck routing with time windows. In these applications, a fully-charged battery allows running a limited operational distance, and the battery before depletion needs to be quickly charged or exchanged with a fully-charged one at a battery management facility. The limited distance and battery renewal result in a shortest path problem with resource renewal. We develop a label-correcting algorithm with state space relaxation to find optimal solutions. In the computational experiments, real-world road geometry data are used to generate realistic travel distances, and other types of data are obtained from the real world or randomly generated. The computational results show that the label-correcting algorithm performs very well.

Enabling fast charging – A battery technology gap assessment

Energy Technology Data Exchange (ETDEWEB)

Ahmed, Shabbir; Bloom, Ira; Jansen, Andrew N.; Tanim, Tanvir; Dufek, Eric J.; Pesaran, Ahmad; Burnham, Andrew; Carlson, Richard B.; Dias, Fernando; Hardy, Keith; Keyser, Matthew; Kreuzer, Cory; Markel, Anthony; Meintz, Andrew; Michelbacher, Christopher; Mohanpurkar, Manish; Nelson, Paul A.; Robertson, David C.; Scoffield, Don; Shirk, Matthew; Stephens, Thomas; Vijayagopal, Ram; Zhang, Jiucai

2017-11-01

The battery technology literature is reviewed, with an emphasis on key elements that limit extreme fast charging. Key gaps in existing elements of the technology are presented as well as developmental needs. Among these needs are advanced models and methods to detect and prevent lithium plating; new positive-electrode materials which are less prone to stress-induced failure; better electrode designs to accommodate very rapid diffusion in and out of the electrode; measure temperature distributions during fast charge to enable / validate models; and develop thermal management and pack designs to accommodate the higher operating voltage.

Nickel-cadmium battery system for electric vehicles

Science.gov (United States)

Klein, M.; Charkey, A.

A nickel-cadmium battery system has been developed and is being evaluated for electric vehicle propulsion applications. The battery system design features include: (1) air circulation through gaps between cells for thermal management, (2) a metal-gas coulometric fuel gauge for state-of-charge and charge control, and (3) a modified constant current ac/dc power supply for the charger. The battery delivers one and a half to two times the energy density of comparable lead-acid batteries depending on operating conditions.

Advanced solid state batteries

Energy Technology Data Exchange (ETDEWEB)

Levasseur, A; Delmas, C; Menetrier, M; Hagenmuller, P

1984-01-01

Direct electrochemical storage of electricity is attractive because of its adaptability to vehicle traction as well as to stationary applications. Important advancements are necessary to improve primary or secondary batteries so far used. The aim of this study was to develop and to characterize materials for the next generation of advanced, rechargeable solid state batteries for vehicle transport and stationary storage applications. One of the best electricity storage systems was the lithium/intercalation compound secondary battery, though up to now the behavior of liquid organic electrolytes did not allow for good recycling in such systems. The research program for these batteries is described.

Nonlinear Filtering Techniques Comparison for Battery State Estimation

Directory of Open Access Journals (Sweden)

Aspasia Papazoglou

2014-09-01

Full Text Available The performance of estimation algorithms is vital for the correct functioning of batteries in electric vehicles, as poor estimates will inevitably jeopardize the operations that rely on un-measurable quantities, such as State of Charge and State of Health. This paper compares the performance of three nonlinear estimation algorithms: the Extended Kalman Filter, the Unscented Kalman Filter and the Particle Filter, where a lithium-ion cell model is considered. The effectiveness of these algorithms is measured by their ability to produce accurate estimates against their computational complexity in terms of number of operations and execution time required. The trade-offs between estimators' performance and their computational complexity are analyzed.

A physics-based fractional order model and state of energy estimation for lithium ion batteries. Part II: Parameter identification and state of energy estimation for LiFePO4 battery

Science.gov (United States)

Li, Xiaoyu; Pan, Ke; Fan, Guodong; Lu, Rengui; Zhu, Chunbo; Rizzoni, Giorgio; Canova, Marcello

2017-11-01

State of energy (SOE) is an important index for the electrochemical energy storage system in electric vehicles. In this paper, a robust state of energy estimation method in combination with a physical model parameter identification method is proposed to achieve accurate battery state estimation at different operating conditions and different aging stages. A physics-based fractional order model with variable solid-state diffusivity (FOM-VSSD) is used to characterize the dynamic performance of a LiFePO4/graphite battery. In order to update the model parameter automatically at different aging stages, a multi-step model parameter identification method based on the lexicographic optimization is especially designed for the electric vehicle operating conditions. As the battery available energy changes with different applied load current profiles, the relationship between the remaining energy loss and the state of charge, the average current as well as the average squared current is modeled. The SOE with different operating conditions and different aging stages are estimated based on an adaptive fractional order extended Kalman filter (AFEKF). Validation results show that the overall SOE estimation error is within ±5%. The proposed method is suitable for the electric vehicle online applications.

Lithium position and occupancy fluctuations in a cathode during charge/discharge cycling of lithium-ion battery

International Nuclear Information System (INIS)

Sharma, N.; Yu, D.; Zhu, Y.; Wu, Y.; Peterson, V. K.

2012-01-01

Lithium-ion batteries are undergoing rapid development to meet the energy demands of the transportation and renewable energy-generation sectors. The capacity of a lithium-ion battery is dependent on the amount of lithium that can be reversibly incorporated into the cathode. Neutron diffraction provides greater sensitivity towards lithium relative to other diffraction techniques. In conjunction with the penetration depth afforded by neutron diffraction, the information concerning lithium gained in a neutron diffraction study allows commercial lithium-ion batteries to be explored with respect to the lithium content in the whole cathode. Furthermore, neutron diffraction instruments featuring area detectors that allow relatively fast acquisitions enable perturbations of lithium location and occupancy in the cathode during charge/discharge cycling to be determined in real time. Here, we present the time, current, and temperature dependent lithium transfer occurring within a cathode functioning under conventional charge-discharge cycling. The lithium location and content, oxygen positional parameter, and lattice parameter of the Li 1+y Mn 2 0 4 cathode are measured and linked to the battery's charge/discharge characteristics (performance). We determine that the lithium-transfer mechanism involves two crystallographic sites, and that the mechanism differs between discharge and charge, explaining the relative ease of discharging (compared with charging) this material. Furthermore, we find that the rate of change of the lattice is faster on charging than discharging, and is dependent on the lithium insertion/ extraction processes (e.g. dependent on how the site occupancies evolve). Using in situ neutron diffraction data the atomic-scale understanding of cathode functionality is revealed, representing detailed information that can be used to direct improvements in battery performance at both the practical and fundamental level.

Batteries. Fundamentals and theory, present state of the art of technology and trends of development. 4. compl. rev. ed.; Batterien. Grundlagen und Theorie, aktueller technischer Stand und Entwicklungstendenzen

Energy Technology Data Exchange (ETDEWEB)

Kiehne, H.A.; Berndt, D.; Fischer, W. [and others

2000-07-01

This volume gives a comprehensive survey of the present state of the electrochemical power storage with special consideration of their technical characteristics of application. The volume is structured as follows: 1) Electrochemical energy storage, general fundamentals; 2) Batteries for electric-powered industrial trucks; 3) Energy supply concepts for driverless industrial trucks; 4) Batteries for electric-powered road vehicles; 5) Battery-fed electric drive from the user's point of view (=charging, maintenance); 6) Safety standards for stationary batteries and battery systems; 7) Batteries for stationary power supplies; 8) Battery operation from the user's point of view; 9) Starter batteries of vehicles; 10) High-energy batteries (e.g. Zn/Br{sub 2}-, Na/S-, Li/FeS-cells, fuel cells); 11) Solar-electric power supply with batteries; 12) Charging methods and charging technique; 13) Technology of battery chargers and current transformer, monitoring methods; 14) Standards and regulations for batteries and battery systems.

Solid-state lithium battery

Science.gov (United States)

Ihlefeld, Jon; Clem, Paul G; Edney, Cynthia; Ingersoll, David; Nagasubramanian, Ganesan; Fenton, Kyle Ross

2014-11-04

The present invention is directed to a higher power, thin film lithium-ion electrolyte on a metallic substrate, enabling mass-produced solid-state lithium batteries. High-temperature thermodynamic equilibrium processing enables co-firing of oxides and base metals, providing a means to integrate the crystalline, lithium-stable, fast lithium-ion conductor lanthanum lithium tantalate (La.sub.1/3-xLi.sub.3xTaO.sub.3) directly with a thin metal foil current collector appropriate for a lithium-free solid-state battery.

Real-Time Implementation of an Extended Kalman Filter and a PI Observer for State Estimation of Rechargeable Li-Ion Batteries in Hybrid Electric Vehicle Applications—A Case Study

Directory of Open Access Journals (Sweden)

Roxana-Elena Tudoroiu

2018-04-01

Full Text Available The Li-Ion battery state-of-charge estimation is an essential task in a continuous dynamic automotive industry for large-scale and successful marketing of hybrid electric vehicles. Also, the state-of-charge of any rechargeable battery, regardless of its chemistry, is an essential condition parameter for battery management systems of hybrid electric vehicles. In this study, we share from our accumulated experience in the control system applications field some preliminary results, especially in modeling, control and state estimation techniques. We investigate the design and effectiveness of two state-of-charge estimators, namely an extended Kalman filter and a proportional integral observer, implemented in a real-time MATLAB environment for a particular Li-Ion battery. Definitely, the aim of this work is to find the most suitable estimator in terms of estimation accuracy and robustness to changes in initial conditions (i.e., the initial guess value of battery state-of-charge and changes in process and measurement noise levels. By a rigorous performance analysis of MATLAB simulation results, the potential estimator choice is revealed. The performance comparison can be done visually on similar graphs if the information gathered provides a good insight, otherwise, it can be done statistically based on the calculus of statistic errors, in terms of root mean square error, mean absolute error and mean square error.

Development of battery management system for nickel-metal hydride batteries in electric vehicle applications

Science.gov (United States)

Jung, Do Yang; Lee, Baek Haeng; Kim, Sun Wook

Electric vehicle (EV) performance is very dependent on traction batteries. For developing electric vehicles with high performance and good reliability, the traction batteries have to be managed to obtain maximum performance under various operating conditions. Enhancement of battery performance can be accomplished by implementing a battery management system (BMS) that plays an important role in optimizing the control mechanism of charge and discharge of the batteries as well as monitoring the battery status. In this study, a BMS has been developed for maximizing the use of Ni-MH batteries in electric vehicles. This system performs several tasks: the control of charging and discharging, overcharge and over-discharge protection, the calculation and display of state-of-charge (SOC), safety, and thermal management. The BMS is installed in and tested in a DEV5-5 electric vehicle developed by Daewoo Motor Co. and the Institute for Advanced Engineering in Korea. Eighteen modules of a Panasonic nickel-metal hydride (Ni-MH) battery, 12 V, 95 A h, are used in the DEV5-5. High accuracy within a range of 3% and good reliability are obtained. The BMS can also improve the performance and cycle-life of the Ni-MH battery peak, as well as the reliability and the safety of the electric vehicles.

Thermal Conductivity Changes Due to Degradation of Cathode Film Subjected to Charge-Discharge Cycles in a Li Ion Battery

Science.gov (United States)

Jagannadham, K.

2018-05-01

A battery device with graphene platelets as anode, lithium nickel manganese oxide as cathode, and solid-state electrolyte consisting of layers of lithium phosphorous oxynitride and lithium lanthanum titanate is assembled on the stainless steel substrate. The battery in a polymer enclosure is subjected to several electrical tests consisting of charge and discharge cycles at different current and voltage levels. Thermal conductivity of the cathode layer is determined at the end of charge-discharge cycles using transient thermoreflectance. The microstructure and composition of the cathode layer and the interface between the cathode, the anode, and the electrolyte are characterized using scanning electron microscopy and elemental mapping. The decrease in the thermal conductivity of the same cathode observed after each set of electrical test cycles is correlated with the volume changes and formation of low ionic and thermal conductivity lithium oxide and lithium oxychloride at the interface and along porous regions. The interface between the metal current collector and the cathode is also found to be responsible for the increase in thermal resistance. The results indicate that changes in the thermal conductivity of the electrodes provide a measure of the resistance to heat transfer and degradation of ionic transport in the cathode accompanying the charge-discharge cycles in the batteries.

Adaptive thermal modeling of Li-ion batteries

International Nuclear Information System (INIS)

Shadman Rad, M.; Danilov, D.L.; Baghalha, M.; Kazemeini, M.; Notten, P.H.L.

2013-01-01

Highlights: • A simple, accurate and adaptive thermal model is proposed for Li-ion batteries. • Equilibrium voltages, overpotentials and entropy changes are quantified from experimental results. • Entropy changes are highly dependent on the battery State-of-Charge. • Good agreement between simulated and measured heat development is obtained under all conditions. • Radiation contributes to about 50% of heat dissipation at elevated temperatures. -- Abstract: An accurate thermal model to predict the heat generation in rechargeable batteries is an essential tool for advanced thermal management in high power applications, such as electric vehicles. For such applications, the battery materials’ details and cell design are normally not provided. In this work a simple, though accurate, thermal model for batteries has been developed, considering the temperature- and current-dependent overpotential heat generation and State-of-Charge dependent entropy contributions. High power rechargeable Li-ion (7.5 Ah) batteries have been experimentally investigated and the results are used for model verification. It is shown that the State-of-Charge dependent entropy is a significant heat source and is therefore essential to correctly predict the thermal behavior of Li-ion batteries under a wide variety of operating conditions. An adaptive model is introduced to obtain these entropy values. A temperature-dependent equation for heat transfer to the environment is also taken into account. Good agreement between the simulations and measurements is obtained in all cases. The parameters for both the heat generation and heat transfer processes can be applied to the thermal design of advanced battery packs. The proposed methodology is generic and independent on the cell chemistry and battery design. The parameters for the adaptive model can be determined by performing simple cell potential/current and temperature measurements for a limited number of charge/discharge cycles

The quasi-steady state of all-vanadium redox flow batteries: A scale analysis

International Nuclear Information System (INIS)

Sharma, A.K.; Vynnycky, M.; Ling, C.Y.; Birgersson, E.; Han, M.

2014-01-01

Highlights: • We present a transient 2D model for a VRFB (conservation of species and charge); • Carry out scale analysis of the species conservation equation; • Derive the condition characterizing the quasi-steadiness of VRFB operation; • Verify it by comparing charge-discharge curve with transient simulations. - Abstract: In general, mathematical models for all-vanadium redox flow batteries (VRFB) that seek to capture the transport phenomena are transient in nature. In this paper, we carry out scale analysis of VRFB operation and derive the conditions when it can be assumed to be quasi-steady state in nature, i.e., time-dependence only through a boundary condition. We find that it is true for typical tank volume and flow rate employed for VRFBs. The proposed analysis is generic and can also be employed for other types of redox flow batteries

Battery charging and discharging research based on the interactive technology of smart grid and electric vehicle

Science.gov (United States)

Zhang, Mingyang

2018-06-01

To further study the bidirectional flow problem of V2G (Vehicle to Grid) charge and discharge motor, the mathematical model of AC/DC converter and bi-directional DC/DC converter was established. Then, lithium battery was chosen as the battery of electric vehicle and its mathematical model was established. In order to improve the service life of lithium battery, bidirectional DC/DC converter adopted constant current and constant voltage control strategy. In the initial stage of charging, constant current charging was adopted with current single closed loop control. After reaching a certain value, voltage was switched to constant voltage charging controlled by voltage and current. Subsequently, the V2G system simulation model was built in MATLAB/Simulink. The simulation results verified the correctness of the control strategy and showed that when charging, constant current and constant voltage charging was achieved, the grid side voltage and current were in the same phase, and the power factor was about 1. When discharging, the constant current discharge was applied, and the grid voltage and current phase difference was r. To sum up, the simulation results are correct and helpful.

A Lossy Counting-Based State of Charge Estimation Method and Its Application to Electric Vehicles

Directory of Open Access Journals (Sweden)

Hong Zhang

2015-12-01

Full Text Available Estimating the residual capacity or state-of-charge (SoC of commercial batteries on-line without destroying them or interrupting the power supply, is quite a challenging task for electric vehicle (EV designers. Many Coulomb counting-based methods have been used to calculate the remaining capacity in EV batteries or other portable devices. The main disadvantages of these methods are the cumulative error and the time-varying Coulombic efficiency, which are greatly influenced by the operating state (SoC, temperature and current. To deal with this problem, we propose a lossy counting-based Coulomb counting method for estimating the available capacity or SoC. The initial capacity of the tested battery is obtained from the open circuit voltage (OCV. The charging/discharging efficiencies, used for compensating the Coulombic losses, are calculated by the lossy counting-based method. The measurement drift, resulting from the current sensor, is amended with the distorted Coulombic efficiency matrix. Simulations and experimental results show that the proposed method is both effective and convenient.

Determination of regression functions for the charging and discharging processes of valve regulated lead-acid batteries

Directory of Open Access Journals (Sweden)

Vukić Vladimir Đ.

2012-01-01

Full Text Available Following a deep discharge of AGM SVT 300 valve-regulated lead-acid batteries using the ten-hour discharge current, the batteries were charged using variable current. In accordance with the obtained results, exponential and polynomial functions for the approximation of the specified processes were analyzed. The main evaluation instrument for the quality of the implemented approximations was the adjusted coefficient of determination R-2. It was perceived that the battery discharge process might be successfully approximated with both an exponential and the second order polynomial function. On all the occasions analyzed, values of the adjusted coefficient of determination were greater than 0.995. The charging process of the deeply discharged batteries was successfully approximated with the exponential function; the measured values of the adjusted coefficient of determination being nearly 0.95. Apart from the high measured values of the adjusted coefficient of determination, polynomial approximations of the second and third order did not provide satisfactory results regarding the interpolation of the battery charging characteristics. A possibility for a practical implementation of the procured regression functions in uninterruptible power supply systems was described.

Monolithic All-Phosphate Solid-State Lithium-Ion Battery with Improved Interfacial Compatibility.

Science.gov (United States)

Yu, Shicheng; Mertens, Andreas; Tempel, Hermann; Schierholz, Roland; Kungl, Hans; Eichel, Rüdiger-A

2018-06-22

High interfacial resistance between solid electrolyte and electrode of ceramic all-solid-state batteries is a major reason for the reduced performance of these batteries. A solid-state battery using a monolithic all-phosphate concept based on screen printed thick LiTi 2 (PO 4 ) 3 anode and Li 3 V 2 (PO 4 ) 3 cathode composite layers on a densely sintered Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 solid electrolyte has been realized with competitive cycling performance. The choice of materials was primarily based on the (electro-)chemical and mechanical matching of the components instead of solely focusing on high-performance of individual components. Thus, the battery utilized a phosphate backbone in combination with tailored morphology of the electrode materials to ensure good interfacial matching for a durable mechanical stability. Moreover, the operating voltage range of the active materials matches with the intrinsic electrochemical window of the electrolyte which resulted in high electrochemical stability. A highly competitive discharge capacity of 63.5 mAh g -1 at 0.39 C after 500 cycles, corresponding to 84% of the initial discharge capacity, was achieved. The analysis of interfacial charge transfer kinetics confirmed the structural and electrical properties of the electrodes and their interfaces with the electrolyte, as evidenced by the excellent cycling performance of the all-phosphate solid-state battery. These interfaces have been studied via impedance analysis with subsequent distribution of relaxation times analysis. Moreover, the prepared solid-state battery could be processed and operated in air atmosphere owing to the low oxygen sensitivity of the phosphate materials. The analysis of electrolyte/electrode interfaces after cycling demonstrates that the interfaces remained stable during cycling.

HST Replacement Battery Initial Performance

Science.gov (United States)

Krol, Stan; Waldo, Greg; Hollandsworth, Roger

2009-01-01

The Hubble Space Telescope (HST) original Nickel-Hydrogen (NiH2) batteries were replaced during the Servicing Mission 4 (SM4) after 19 years and one month on orbit.The purpose of this presentation is to highlight the findings from the assessment of the initial sm4 replacement battery performance. The batteries are described, the 0 C capacity is reviewed, descriptions, charts and tables reviewing the State Of Charge (SOC) Performance, the Battery Voltage Performance, the battery impedance, the minimum voltage performance, the thermal performance, the battery current, and the battery system recharge ratio,

Model Based Optimal Control, Estimation, and Validation of Lithium-Ion Batteries

Science.gov (United States)

Perez, Hector Eduardo

This dissertation focuses on developing and experimentally validating model based control techniques to enhance the operation of lithium ion batteries, safely. An overview of the contributions to address the challenges that arise are provided below. Chapter 1: This chapter provides an introduction to battery fundamentals, models, and control and estimation techniques. Additionally, it provides motivation for the contributions of this dissertation. Chapter 2: This chapter examines reference governor (RG) methods for satisfying state constraints in Li-ion batteries. Mathematically, these constraints are formulated from a first principles electrochemical model. Consequently, the constraints explicitly model specific degradation mechanisms, such as lithium plating, lithium depletion, and overheating. This contrasts with the present paradigm of limiting measured voltage, current, and/or temperature. The critical challenges, however, are that (i) the electrochemical states evolve according to a system of nonlinear partial differential equations, and (ii) the states are not physically measurable. Assuming available state and parameter estimates, this chapter develops RGs for electrochemical battery models. The results demonstrate how electrochemical model state information can be utilized to ensure safe operation, while simultaneously enhancing energy capacity, power, and charge speeds in Li-ion batteries. Chapter 3: Complex multi-partial differential equation (PDE) electrochemical battery models are characterized by parameters that are often difficult to measure or identify. This parametric uncertainty influences the state estimates of electrochemical model-based observers for applications such as state-of-charge (SOC) estimation. This chapter develops two sensitivity-based interval observers that map bounded parameter uncertainty to state estimation intervals, within the context of electrochemical PDE models and SOC estimation. Theoretically, this chapter extends the

Application-specific electrical characterization of high power batteries with lithium titanate anodes for electric vehicles

International Nuclear Information System (INIS)

Farmann, Alexander; Waag, Wladislaw; Sauer, Dirk Uwe

2016-01-01

This study shows results of extensive experimental measurements performed on high power lithium titanate based batteries. Characterization tests are performed over a wide temperature range (−20 °C – +40 °C) by employing electrochemical impedance spectroscopy and modified hybrid pulse power characterization tests. Furthermore, the behavior of battery impedance parameters over the battery lifetime with regard to temperature, State-of-Charge and their influence on available battery power in an example of electric vehicles is discussed. Based on extracted parameters, a reduced order equivalent circuit model considering the nonlinearity of the charge transfer resistance is parametrized. The obtained results indicate that ohmic resistance increases with decreasing State-of-Charge while the shape of the curve remains almost constant over the battery lifetime. The total impedance determined at 1 mHz shows almost no dependence on State-of-Charge and remains constant over the whole State-of-Charge range. The necessity of considering the impact of the current dependence of the direct current resistance at least at low temperatures (i.e., below 0 °C) is confirmed. Moreover, by investigating the Butler-Volmer equation the behavior of exchange current density and symmetry factor is analyzed for various temperatures and State-of-Charges over the battery lifetime. - Highlights: • Impedance characteristic over the battery lifetime is investigated. • Batteries at different aging states using lithium titanate anodes are investigated. • The influence of temperature on impedance characteristic is investigated. • Butler-Volmer behavior is comprehensively investigated under various conditions.

Sequential Monte Carlo filter for state estimation of LiFePO4 batteries based on an online updated model

Science.gov (United States)

Li, Jiahao; Klee Barillas, Joaquin; Guenther, Clemens; Danzer, Michael A.

2014-02-01

Battery state monitoring is one of the key techniques in battery management systems e.g. in electric vehicles. An accurate estimation can help to improve the system performance and to prolong the battery remaining useful life. Main challenges for the state estimation for LiFePO4 batteries are the flat characteristic of open-circuit-voltage over battery state of charge (SOC) and the existence of hysteresis phenomena. Classical estimation approaches like Kalman filtering show limitations to handle nonlinear and non-Gaussian error distribution problems. In addition, uncertainties in the battery model parameters must be taken into account to describe the battery degradation. In this paper, a novel model-based method combining a Sequential Monte Carlo filter with adaptive control to determine the cell SOC and its electric impedance is presented. The applicability of this dual estimator is verified using measurement data acquired from a commercial LiFePO4 cell. Due to a better handling of the hysteresis problem, results show the benefits of the proposed method against the estimation with an Extended Kalman filter.

Integration of sampling based battery state of health estimation method in electric vehicles

International Nuclear Information System (INIS)

Ozkurt, Celil; Camci, Fatih; Atamuradov, Vepa; Odorry, Christopher

2016-01-01

Highlights: • Presentation of a prototype system with full charge discharge cycling capability. • Presentation of SoH estimation results for systems degraded in the lab. • Discussion of integration alternatives of the presented method in EVs. • Simulation model based on presented SoH estimation for a real EV battery system. • Optimization of number of battery cells to be selected for SoH test. - Abstract: Battery cost is one of the crucial parameters affecting high deployment of Electric Vehicles (EVs) negatively. Accurate State of Health (SoH) estimation plays an important role in reducing the total ownership cost, availability, and safety of the battery avoiding early disposal of the batteries and decreasing unexpected failures. A circuit design for SoH estimation in a battery system that bases on selected battery cells and its integration to EVs are presented in this paper. A prototype microcontroller has been developed and used for accelerated aging tests for a battery system. The data collected in the lab tests have been utilized to simulate a real EV battery system. Results of accelerated aging tests and simulation have been presented in the paper. The paper also discusses identification of the best number of battery cells to be selected for SoH estimation test. In addition, different application options of the presented approach for EV batteries have been discussed in the paper.

Adaptive online state-of-charge determination based on neuro-controller and neural network

Energy Technology Data Exchange (ETDEWEB)

Shen Yanqing, E-mail: network_hawk@126.co [Department of Automation, Chongqing Industry Polytechnic College, Jiulongpo District, Chongqing 400050 (China)

2010-05-15

This paper presents a novel approach using adaptive artificial neural network based model and neuro-controller for online cell State of Charge (SOC) determination. Taking cell SOC as model's predictive control input unit, radial basis function neural network, which can adjust its structure to prediction error with recursive least square algorithm, is used to simulate battery system. Besides that, neuro-controller based on Back-Propagation Neural Network (BPNN) and modified PID controller is used to decide the control input of battery system, i.e., cell SOC. Finally this algorithm is applied for the SOC determination of lead-acid batteries, and results of lab tests on physical cells, compared with model prediction, are presented. Results show that the ANN based battery system model adaptively simulates battery system with great accuracy, and the predicted SOC simultaneously converges to the real value quickly within the error of +-1 as time goes on.

Performance comparison of four lithium–ion battery technologies under calendar aging

International Nuclear Information System (INIS)

Eddahech, Akram; Briat, Olivier; Vinassa, Jean-Michel

2015-01-01

This work depicts the calendar aging results of four Li-ion battery technologies. The differences in the chemistry of Li-ion batteries was studied and revealed that cathodes containing manganese are more sensitive to state-of-charge and temperature increase than lithium–iron-phosphate or lithium–nickel–cobalt–aluminum batteries. The first step in presenting the differences in technology of the Li-ion battery is through the study of the battery voltage evolution versus the amount of charge at various states of health. This study revealed a significant increase in resistance on lithium–nickel–manganese–cobalt and lithium–manganese-oxide cells; a result which was confirmed through impedance spectroscopy measurements. Finally, a study of the comparison of the different types of Li-ion batteries was undertaken, based on the analysis of the evolution of energy efficiency with respect to aging. - Highlights: • Calendar aging results of four Li-ion battery technologies are presented. • High temperature and/or the increased state-of-charge accelerated battery aging. • We analyzed the evolution of energy efficiency with respect to aging. • Cathodes with manganese are more sensitive to SOC and temperature increase

Using Atmospheric Pressure Tendency to Optimise Battery Charging in Off-Grid Hybrid Wind-Diesel Systems for Telecoms

Directory of Open Access Journals (Sweden)

Stephen Daniels

2013-06-01

Full Text Available Off grid telecom base stations in developing nations are powered by diesel generators. They are typically oversized and run at a fraction of their rated load for most of their operating lifetime. Running generators at partial load is inefficient and, over time, physically damages the engine. A hybrid configuration uses a battery bank, which powers the telecoms’ load for a portion of the time. The generator only operates when the battery bank needs to be charged. Adding a wind turbine further reduces the generator run hours and saves fuel. The generator is oblivious to the current wind conditions, which leads to simultaneous generator-wind power production. As the batteries become charged by the generator, the wind turbine controller is forced to dump surplus power as heat through a resistive load. This paper details how the relationship between barometric pressure and wind speed can be used to add intelligence to the battery charger. A Simulink model of the system is developed to test the different battery charging configurations. This paper demonstrates that if the battery charger is aware of upcoming wind conditions, it will provide modest fuel savings and reduce generator run hours in small-scale hybrid energy systems.

Photovoltaic battery charging stations for sustainable off-grid rural electrification in the Philippines

International Nuclear Information System (INIS)

Pascual, C.M.; Acebedo, I.P.; Gudoy, F.

2005-01-01

The Mariano Marcos State University-Affiliated Non Conventional Energy Center (MMSU-ANEC) in partnership with the Energy Management Bureau-Renewable Energy Management Division, Department of Energy implemented the Barangay Electrification Program (BEP) of the government in the off-grid rural areas at the northern Philippines from 1995-2004 with a common vision of promoting the use of new and renewable energy systems for rural electrification in order to spur development in the far-flung, off-grid rural areas. Such activity of the MMSU-ANEC on BEP used modified and improved Photovoltaic battery charging stations (PVBCS) to energize households and augment their livelihood in collaboration with the local government units and the beneficiaries. Socioeconomic and environmental impacts using long-range energy alternative planning or LEAP software showed that PVBCS are indispensable, feasible, economical, environmental-friendly and sustainable renewable energy resources systems in off-grid areas. Improvement of a locally-made battery charging unit (patent applied at IPO, Manila) which is cheaper and comparable than the imported unit, enabling project implementation strategies in community organizing and lessons learned during the implementation of BEP are also presented. Such improvement of the PVBCS is considered an innovative advancement in renewable energy that can be commercialized towards a sustainable agro-industrial development in far-flung, off-grid rural areas, among other applications for rural electrification and power generation using clean and environment-friendly sustainable technologies. (author)

Polyoxovanadate-alkoxide clusters as multi-electron charge carriers for symmetric non-aqueous redox flow batteries.

Science.gov (United States)

VanGelder, L E; Kosswattaarachchi, A M; Forrestel, P L; Cook, T R; Matson, E M

2018-02-14

Non-aqueous redox flow batteries have emerged as promising systems for large-capacity, reversible energy storage, capable of meeting the variable demands of the electrical grid. Here, we investigate the potential for a series of Lindqvist polyoxovanadate-alkoxide (POV-alkoxide) clusters, [V 6 O 7 (OR) 12 ] (R = CH 3 , C 2 H 5 ), to serve as the electroactive species for a symmetric, non-aqueous redox flow battery. We demonstrate that the physical and electrochemical properties of these POV-alkoxides make them suitable for applications in redox flow batteries, as well as the ability for ligand modification at the bridging alkoxide moieties to yield significant improvements in cluster stability during charge-discharge cycling. Indeed, the metal-oxide core remains intact upon deep charge-discharge cycling, enabling extremely high coulombic efficiencies (∼97%) with minimal overpotential losses (∼0.3 V). Furthermore, the bulky POV-alkoxide demonstrates significant resistance to deleterious crossover, which will lead to improved lifetime and efficiency in a redox flow battery.

Redox reactions with empirical potentials: atomistic battery discharge simulations.

Science.gov (United States)

Dapp, Wolf B; Müser, Martin H

2013-08-14

Batteries are pivotal components in overcoming some of today's greatest technological challenges. Yet to date there is no self-consistent atomistic description of a complete battery. We take first steps toward modeling of a battery as a whole microscopically. Our focus lies on phenomena occurring at the electrode-electrolyte interface which are not easily studied with other methods. We use the redox split-charge equilibration (redoxSQE) method that assigns a discrete ionization state to each atom. Along with exchanging partial charges across bonds, atoms can swap integer charges. With redoxSQE we study the discharge behavior of a nano-battery, and demonstrate that this reproduces the generic properties of a macroscopic battery qualitatively. Examples are the dependence of the battery's capacity on temperature and discharge rate, as well as performance degradation upon recharge.

Fuzzy logic modeling of EIS measurements on lithium-ion batteries

International Nuclear Information System (INIS)

Singh, Pritpal; Vinjamuri, Ramana; Wang, Xiquan; Reisner, David

2006-01-01

A fuzzy logic-based state of health (SOH) meter is being developed for lithium-ion (Li-ion) batteries for potential use in portable defibrillators. Electrochemical impedance spectroscopy (EIS) measurements have been made from which input parameters for a fuzzy logic model to estimate the state of charge (SOC) and SOH are derived. The batteries are discharged continuously at a 1.4 A load current to simulate the constant current draw during the monitoring and recording of a patient's EKG, and periodically interrupted by 10 A pulses to simulate the battery discharge to charge up the capacitor that is in turn discharged to supply high voltage to the electrodes for the defibrillation of the patient. The test procedures included both voltage recovery and EIS measurements, and were made as the batteries were being discharged and over 30 charge/discharge cycles. Accurate models have been developed to estimate the number of pulses that the battery pack can deliver at various stages of its cycle life (SOC measure) and the number of charge/discharge cycles (SOH measure) that it had undergone

A comparative study and validation of state estimation algorithms for Li-ion batteries in battery management systems

International Nuclear Information System (INIS)

Klee Barillas, Joaquín; Li, Jiahao; Günther, Clemens; Danzer, Michael A.

2015-01-01

Highlights: • Description of state observers for estimating the battery’s SOC. • Implementation of four estimation algorithms in a BMS. • Reliability and performance study of BMS regarding the estimation algorithms. • Analysis of the robustness and code properties of the estimation approaches. • Guide to evaluate estimation algorithms to improve the BMS performance. - Abstract: To increase lifetime, safety, and energy usage battery management systems (BMS) for Li-ion batteries have to be capable of estimating the state of charge (SOC) of the battery cells with a very low estimation error. The accurate SOC estimation and the real time reliability are critical issues for a BMS. In general an increasing complexity of the estimation methods leads to higher accuracy. On the other hand it also leads to a higher computational load and may exceed the BMS limitations or increase its costs. An approach to evaluate and verify estimation algorithms is presented as a requisite prior the release of the battery system. The approach consists of an analysis concerning the SOC estimation accuracy, the code properties, complexity, the computation time, and the memory usage. Furthermore, a study for estimation methods is proposed for their evaluation and validation with respect to convergence behavior, parameter sensitivity, initialization error, and performance. In this work, the introduced analysis is demonstrated with four of the most published model-based estimation algorithms including Luenberger observer, sliding-mode observer, Extended Kalman Filter and Sigma-point Kalman Filter. The experiments under dynamic current conditions are used to verify the real time functionality of the BMS. The results show that a simple estimation method like the sliding-mode observer can compete with the Kalman-based methods presenting less computational time and memory usage. Depending on the battery system’s application the estimation algorithm has to be selected to fulfill the

Electric batteries. Fundamental principles and theory, present state of the art of technology and trends of development. 3. rev. and enlarged ed. Batterien. Grundlagen und Theorie, aktueller technischer Stand und Entwicklungstendenzen

Energy Technology Data Exchange (ETDEWEB)

Kiehne, H.A.; Berndt, D.; Boettger, K.; Fischer, W.; Franke, H.; Friedheim, G.; Koethe, H.K.; Krakowski, H.; Middendorf, E.; Preuss, P.

1988-01-01

This volume gives a comprehensive survey of the present state of the electrochemical power storage with special consideration of their technical characteristics of application. The volume is structured as follows: 1) Electrochemical energy storage, general fundamentals; 2) Batteries for electric-powered industrial trucks; 2a) Energy supply concepts for driverless industrial trucks; 3) Batteries for electric-powered road vehicles; 4) Battery-fed electric drive from the user's point of view (=charging, maintenance); 5) Secured power supply with electric batteries; 6) Batteries for stationary power supplies; 7) Operation and use of batteries for a large-scale consumer (emergency power supplies for communication equipment of the Deutsche Bundespost); 8) Starter batteries of vehicles; 9) High-energy batteries (e.g. Zn/Cl/sub 2/-, Na/S-, Li/FeS-cells, fuel cells); 10) Solar-electric power supply with batteries; 11) Charging methods and charging technique; 12) Technology of battery chargers and current transformer, monitoring methods; 13) Standards and regulations for batteries and battery systems. (MM) With 192 figs.

Lead-acid batteries life time prolongation in renewable energy source plants

Directory of Open Access Journals (Sweden)

Костянтин Ігорович Ткаченко

2015-11-01

Full Text Available Charge controllers with microprocessor control are recognized to be almost optimal process control devices for collecting and storing energy in batteries in power systems with renewable energy sources such as solar photoelectric batteries, wind electrogenerators and others. The task of the controller is charging process control, that is such as charging and discharging the batteries while providing maximum charging speed and battery saving parameters that characterize the state of the battery, within certain limits, preventing overcharging, overheating and the batteries deep discharge. The possibility of archiving data that keeps the battery parameters time dependance is also important. Thus, the concept of a charge controller with Texas Instruments microcontroller device MSP430G2553 was introduced in the study. The program saved in the ROM microcontroller provides for: charge regime(with a particular algorithm; control and training cycle followed by charging; continuous charge-discharge regime to restore the battery or the study of charge regime algorithms influence on repair effectiveness. The device can perform its functions without being connected to a personal computer, but this connection makes it possible to observe in real time the characteristics of a number of discharge and charge regimes parameters, as well as reading the stored data from microcontroller flash memory and storing these data on the PC hard disk for further analysis. A four stages charging algorithm with reverse charging regime was offered by the author and correctness of algorithm was proved

Cascade redox flow battery systems

Science.gov (United States)

Horne, Craig R.; Kinoshita, Kim; Hickey, Darren B.; Sha, Jay E.; Bose, Deepak

2014-07-22

A reduction/oxidation ("redox") flow battery system includes a series of electrochemical cells arranged in a cascade, whereby liquid electrolyte reacts in a first electrochemical cell (or group of cells) before being directed into a second cell (or group of cells) where it reacts before being directed to subsequent cells. The cascade includes 2 to n stages, each stage having one or more electrochemical cells. During a charge reaction, electrolyte entering a first stage will have a lower state-of-charge than electrolyte entering the nth stage. In some embodiments, cell components and/or characteristics may be configured based on a state-of-charge of electrolytes expected at each cascade stage. Such engineered cascades provide redox flow battery systems with higher energy efficiency over a broader range of current density than prior art arrangements.

An improved PNGV modeling and SOC estimation for lithium iron phosphate batteries

Science.gov (United States)

Li, Peng

2017-11-01

Because lithium iron phosphate battery has many advantages, it has been used more and more widely in the field of electric vehicle. The lithium iron phosphate battery, presents the improved PNGV model, and the batteries charge discharge characteristics and pulse charge discharge experiments, identification of parameters of the battery model by interpolation and least square fitting method, to achieve a more accurate modeling of lithium iron phosphate battery, and the extended Calman filter algorithm (EKF) is completed state nuclear power battery (SOC) estimate.

Crash Models for Advanced Automotive Batteries: A Review of the Current State of the Art

Energy Technology Data Exchange (ETDEWEB)

Turner, John A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Allu, Srikanth [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Gorti, Sarma B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Kalnaus, Sergiy [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Kumar, Abhishek [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lebrun-Grandie, Damien T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Pannala, Sreekanth [Saudi Arabia Basic Industries Corporation (SABIC), Houston, TX (United States); Simunovic, Srdjan [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Slattery, Stuart R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wang, Hsin [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2015-02-01

Safety is a critical aspect of lithium-ion (Li-ion) battery design. Impact/crash conditions can trigger a complex interplay of mechanical contact, heat generation and electrical discharge, which can result in adverse thermal events. The cause of these thermal events has been linked to internal contact between the opposite electrodes, i.e. internal short circuit. The severity of the outcome is influenced by the configuration of the internal short circuit and the battery state. Different loading conditions and battery states may lead to micro (soft) shorts where material burnout due to generated heat eliminates contact between the electrodes, or persistent (hard) shorts which can lead to more significant thermal events and potentially damage the entire battery system and beyond. Experimental characterization of individual battery components for the onset of internal shorts is limited, since it is impractical to canvas all possible variations in battery state of charge, operating conditions, and impact loading in a timely manner. This report provides a survey of modeling and simulation approaches and documents a project initiated and funded by DOT/NHTSA to improve modeling and simulation capabilities in order to design tests that provide leading indicators of failure in batteries. In this project, ORNL has demonstrated a computational infrastructure to conduct impact simulations of Li-ion batteries using models that resolve internal structures and electro-thermo-chemical and mechanical conditions. Initial comparisons to abuse experiments on cells and cell strings conducted at ORNL and Naval Surface Warfare Center (NSWC) at Carderock MD for parameter estimation and model validation have been performed. This research has provided insight into the mechanisms of deformation in batteries (both at cell and electrode level) and their relationship to the safety of batteries.

Portable Battery Charger Berbasis Sel Surya

Directory of Open Access Journals (Sweden)

Budhi Anto

2014-04-01

Full Text Available A type of solar battery charger is introduced in this paper. This equipment functions as a medium size rechargeable battery that is needed to move culinary merchants and coastal fishermen living in area which is not supplied by electrical networks. The equipment consists of solar module mounted onto portable mechanical construction, a 12-V 7.5-Ah lead acid battery and charge controller. Solar module charges the battery through charge controller and then the battery can be discharged to power on electric lamps for lightening culinary wagon or fisherman’s boat at night. Charge controller charges the battery with float charging which is implemented by maintaining 13.5 Volt between battery terminals and limiting the charging current to 1.5 Amperes. Charge controller circuit is based on adjustable linear voltage regulator LM338. The battery is of sealed lead acid type. This type of battery is maintenance free and more hygiene than other types of lead acid battery. The field experiment of charging the baterry of 50% residual capacity from 8 am to 4 pm under sunny weather shows that the solar module has charged the battery to its full capacity under battery safe charging conditions.Keywords: portable solar battery charger, float charging, LM338

A New Battery Energy Storage Charging/Discharging Scheme for Wind Power Producers in Real-Time Markets

Directory of Open Access Journals (Sweden)

Minh Y Nguyen

2012-12-01

Full Text Available Under a deregulated environment, wind power producers are subject to many regulation costs due to the intermittence of natural resources and the accuracy limits of existing prediction tools. This paper addresses the operation (charging/discharging problem of battery energy storage installed in a wind generation system in order to improve the value of wind power in the real-time market. Depending on the prediction of market prices and the probabilistic information of wind generation, wind power producers can schedule the battery energy storage for the next day in order to maximize the profit. In addition, by taking into account the expenses of using batteries, the proposed charging/discharging scheme is able to avoid the detrimental operation of battery energy storage which can lead to a significant reduction of battery lifetime, i.e., uneconomical operation. The problem is formulated in a dynamic programming framework and solved by a dynamic programming backward algorithm. The proposed scheme is then applied to the study cases, and the results of simulation show its effectiveness.

A VRLA battery simulation model

International Nuclear Information System (INIS)

Pascoe, Phillip E.; Anbuky, Adnan H.

2004-01-01

A valve regulated lead acid (VRLA) battery simulation model is an invaluable tool for the standby power system engineer. The obvious use for such a model is to allow the assessment of battery performance. This may involve determining the influence of cells suffering from state of health (SOH) degradation on the performance of the entire string, or the running of test scenarios to ascertain the most suitable battery size for the application. In addition, it enables the engineer to assess the performance of the overall power system. This includes, for example, running test scenarios to determine the benefits of various load shedding schemes. It also allows the assessment of other power system components, either for determining their requirements and/or vulnerabilities. Finally, a VRLA battery simulation model is vital as a stand alone tool for educational purposes. Despite the fundamentals of the VRLA battery having been established for over 100 years, its operating behaviour is often poorly understood. An accurate simulation model enables the engineer to gain a better understanding of VRLA battery behaviour. A system level multipurpose VRLA battery simulation model is presented. It allows an arbitrary battery (capacity, SOH, number of cells and number of strings) to be simulated under arbitrary operating conditions (discharge rate, ambient temperature, end voltage, charge rate and initial state of charge). The model accurately reflects the VRLA battery discharge and recharge behaviour. This includes the complex start of discharge region known as the coup de fouet

A Practical Circuit-based Model for State of Health Estimation of Li-ion Battery Cells in Electric Vehicles

Energy Technology Data Exchange (ETDEWEB)

Lam, Long

2011-08-23

In this thesis the development of the state of health of Li-ion battery cells under possible real-life operating conditions in electric cars has been characterised. Furthermore, a practical circuit-based model for Li-ion cells has been developed that is capable of modelling the cell voltage behaviour under various operating conditions. The Li-ion cell model can be implemented in simulation programs and be directly connected to a model of the rest of the electronic system in electric vehicles. Most existing battery models are impractical for electric vehicle system designers and require extensive background knowledge of electrochemistry to be implemented. Furthermore, many models do not take the effect of regenerative braking into account and are obtained from testing fully charged cells. However, in real-life applications electric vehicles are not always fully charged and utilise regenerative braking to save energy. To obtain a practical circuit model based on real operating conditions and to model the state of health of electric vehicle cells, numerous 18650 size LiFePO4 cells have been tested under possible operating conditions. Capacity fading was chosen as the state of health parameter, and the capacity fading of different cells was compared with the charge processed instead of cycles. Tests have shown that the capacity fading rate is dependent on temperature, charging C-rate, state of charge and depth of discharge. The obtained circuit model is capable of simulating the voltage behaviour under various temperatures and C-rates with a maximum error of 14mV. However, modelling the effect of different temperatures and C-rates increases the complexity of the model. The model is easily adjustable and the choice is given to the electric vehicle system designer to decide which operating conditions to take into account. By combining the test results for the capacity fading and the proposed circuit model, recommendations to optimise the battery lifetime are proposed.

A Novel Intelligent Method for the State of Charge Estimation of Lithium-Ion Batteries Using a Discrete Wavelet Transform-Based Wavelet Neural Network

Directory of Open Access Journals (Sweden)

Deyu Cui

2018-04-01

Full Text Available State of charge (SOC estimation is becoming increasingly important, along with electric vehicle (EV rapid development, while SOC is one of the most significant parameters for the battery management system, indicating remaining energy and ensuring the safety and reliability of EV. In this paper, a hybrid wavelet neural network (WNN model combining the discrete wavelet transform (DWT method and adaptive WNN is proposed to estimate the SOC of lithium-ion batteries. The WNN model is trained by Levenberg-Marquardt (L-M algorithm, whose inputs are processed by discrete wavelet decomposition and reconstitution. Compared with back-propagation neural network (BPNN, L-M based BPNN (LMBPNN, L-M based WNN (LMWNN, DWT with L-M based BPNN (DWTLMBPNN and extend Kalman filter (EKF, the proposed intelligent SOC estimation method is validated and proved to be effective. Under the New European Driving Cycle (NEDC, the mean absolute error and maximum error can be reduced to 0.59% and 3.13%, respectively. The characteristics of high accuracy and strong robustness of the proposed method are verified by comparison study and robustness evaluation results (e.g., measurement noise test and untrained driving cycle test.

Online Parameter Identification and State of Charge Estimation of Lithium-Ion Batteries Based on Forgetting Factor Recursive Least Squares and Nonlinear Kalman Filter

Directory of Open Access Journals (Sweden)

Bizhong Xia

2017-12-01

Full Text Available State of charge (SOC estimation is the core of any battery management system. Most closed-loop SOC estimation algorithms are based on the equivalent circuit model with fixed parameters. However, the parameters of the equivalent circuit model will change as temperature or SOC changes, resulting in reduced SOC estimation accuracy. In this paper, two SOC estimation algorithms with online parameter identification are proposed to solve this problem based on forgetting factor recursive least squares (FFRLS and nonlinear Kalman filter. The parameters of a Thevenin model are constantly updated by FFRLS. The nonlinear Kalman filter is used to perform the recursive operation to estimate SOC. Experiments in variable temperature environments verify the effectiveness of the proposed algorithms. A combination of four driving cycles is loaded on lithium-ion batteries to test the adaptability of the approaches to different working conditions. Under certain conditions, the average error of the SOC estimation dropped from 5.6% to 1.1% after adding the online parameters identification, showing that the estimation accuracy of proposed algorithms is greatly improved. Besides, simulated measurement noise is added to the test data to prove the robustness of the algorithms.

Joint optimisation of arbitrage profits and battery life degradation for grid storage application of battery electric vehicles

Science.gov (United States)

Kies, Alexander

2018-02-01

To meet European decarbonisation targets by 2050, the electrification of the transport sector is mandatory. Most electric vehicles rely on lithium-ion batteries, because they have a higher energy/power density and longer life span compared to other practical batteries such as zinc-carbon batteries. Electric vehicles can thus provide energy storage to support the system integration of generation from highly variable renewable sources, such as wind and photovoltaics (PV). However, charging/discharging causes batteries to degradate progressively with reduced capacity. In this study, we investigate the impact of the joint optimisation of arbitrage revenue and battery degradation of electric vehicle batteries in a simplified setting, where historical prices allow for market participation of battery electric vehicle owners. It is shown that the joint optimisation of both leads to stronger gains then the sum of both optimisation strategies and that including battery degradation into the model avoids state of charges close to the maximum at times. It can be concluded that degradation is an important aspect to consider in power system models, which incorporate any kind of lithium-ion battery storage.

Integrated modeling for the cyclic behavior of high power Li-ion batteries under extended operating conditions

International Nuclear Information System (INIS)

Miranda, Á.G.; Hong, C.W.

2013-01-01

Highlights: • Redefine the traditional concepts of state of charge modeling. • Accurate non-intrusive extraction method of an integrated battery model. • Indexes of performance can be employed to compare different types of batteries. • High power electrical battery model dependent on current and temperature effects. - Abstract: The dynamic thermal and electrical behavior of high power LiFePO 4 cathode-type Li-ion batteries is studied with extended considerations such as demanded current ranging from 12 to 30 A, battery temperatures ranging from 283 to 313 K and a redefinition of the concept of state of charge during cycling conditions. The equivalent electrical model, consisting of a series resistance, a parallel resistance–capacitor, a voltage source and state of charge calculators, can be improved with the addition of current and temperature gains for each element. In addition, a non-intrusively-obtained alternative thermal model extraction is proposed to uncouple from the experimental battery temperature based on electrochemical research found in the literature. This improved model extraction for high power cylindrical batteries can achieve a temperature and voltage relative runtime error in the range of 1% and 5% in average, respectively. The effects of lithium concentration in the anode and cathode are accurately predicted with state of charge accelerators, which vary linearly with temperature. Aiming for a power systems environment, the integrated battery model is built and validated experimentally to demonstrate its accurate prediction. This improved integrated battery model can be employed for battery stack simulations, improved state of charge algorithm testing and optimization of hybrid systems - with a light computational demand. Finally, a performance index radar plot is proposed to conveniently compare electrical and thermal properties of different types of batteries

Fast charging technique for high power LiFePO4 batteries: A mechanistic analysis of aging

Science.gov (United States)

Anseán, D.; Dubarry, M.; Devie, A.; Liaw, B. Y.; García, V. M.; Viera, J. C.; González, M.

2016-07-01

One of the major issues hampering the acceptance of electric vehicles (EVs) is the anxiety associated with long charging time. Hence, the ability to fast charging lithium-ion battery (LIB) systems is gaining notable interest. However, fast charging is not tolerated by all LIB chemistries because it affects battery functionality and accelerates its aging processes. Here, we investigate the long-term effects of multistage fast charging on a commercial high power LiFePO4-based cell and compare it to another cell tested under standard charging. Coupling incremental capacity (IC) and IC peak area analysis together with mechanistic model simulations ('Alawa' toolbox with harvested half-cell data), we quantify the degradation modes that cause aging of the tested cells. The results show that the proposed fast charging technique caused similar aging effects as standard charging. The degradation is caused by a linear loss of lithium inventory, coupled with a less degree of linear loss of active material on the negative electrode. This study validates fast charging as a feasible mean of operation for this particular LIB chemistry and cell architecture. It also illustrates the benefits of a mechanistic approach to understand cell degradation on commercial cells.

Analysis of Pressure Variations in a Low-Pressure Nickel-Hydrogen Battery - Part 1.

Science.gov (United States)

Purushothaman, B K; Wainright, J S

2012-05-15

A low pressure nickel-hydrogen battery using either a metal hydride or gaseous hydrogen for H(2) storage has been developed for use in implantable neuroprosthetic devices. In this paper, pressure variations inside the cell for the gaseous hydrogen version are analyzed and correlated with oxygen evolution side reaction at the end of charging, the recombination of oxygen with hydrogen during charging and a subsequent rest period, and the self-discharge of the nickel electrode. About 70% of the recombination occurred simultaneously with oxygen evolution during charging and the remaining oxygen recombined with hydrogen during the 1(st) hour after charging. Self-discharge of the cell varies linearly with hydrogen pressure at a given state of charge and increased with increasing battery charge levels. The coulometric efficiency calculated based on analysis of the pressure-time data agreed well with the efficiency calculated based on the current-time data. Pressure variations in the battery are simulated accurately to predict coulometric efficiency and the state of charge of the cell, factors of extreme importance for a battery intended for implantation within the human body.

Fuzzy Sliding Mode Observer with Grey Prediction for the Estimation of the State-of-Charge of a Lithium-Ion Battery

Directory of Open Access Journals (Sweden)

Daehyun Kim

2015-11-01

Full Text Available We propose a state-of-charge (SOC estimation method for Li-ion batteries that combines a fuzzy sliding mode observer (FSMO with grey prediction. Unlike the existing methods based on a conventional first-order sliding mode observer (SMO and an adaptive gain SMO, the proposed method eliminates chattering in SOC estimation. In this method, which uses a fuzzy inference system, the gains of the SMO are adjusted according to the predicted future error and present estimation error of the terminal voltage. To forecast the future error value, a one-step-ahead terminal voltage prediction is obtained using a grey predictor. The proposed estimation method is validated through two types of discharge tests (a pulse discharge test and a random discharge test. The SOC estimation results are compared to the results of the conventional first-order SMO-based and the adaptive gain SMO-based methods. The experimental results show that the proposed method not only reduces chattering, but also improves estimation accuracy.

A quick on-line state of health estimation method for Li-ion battery with incremental capacity curves processed by Gaussian filter

Science.gov (United States)

Li, Yi; Abdel-Monem, Mohamed; Gopalakrishnan, Rahul; Berecibar, Maitane; Nanini-Maury, Elise; Omar, Noshin; van den Bossche, Peter; Van Mierlo, Joeri

2018-01-01

This paper proposes an advanced state of health (SoH) estimation method for high energy NMC lithium-ion batteries based on the incremental capacity (IC) analysis. IC curves are used due to their ability of detect and quantify battery degradation mechanism. A simple and robust smoothing method is proposed based on Gaussian filter to reduce the noise on IC curves, the signatures associated with battery ageing can therefore be accurately identified. A linear regression relationship is found between the battery capacity with the positions of features of interest (FOIs) on IC curves. Results show that the developed SoH estimation function from one single battery cell is able to evaluate the SoH of other batteries cycled under different cycling depth with less than 2.5% maximum errors, which proves the robustness of the proposed method on SoH estimation. With this technique, partial charging voltage curves can be used for SoH estimation and the testing time can be therefore largely reduced. This method shows great potential to be applied in reality, as it only requires static charging curves and can be easily implemented in battery management system (BMS).

System and Battery Charge Control for PV-Powered AC Lighting Systems

Energy Technology Data Exchange (ETDEWEB)

Kern, G.

1999-04-01

This report reviews a number of issues specific to stand-alone AC lighting systems. A review of AC lighting technology is presented, which discusses the advantages and disadvantages of various lamps. The best lamps for small lighting systems are compact fluorescent. The best lamps for intermediate-size systems are high- or low-pressure sodium. Specifications for battery charging and load control are provided with the goal of achieving lamp lifetimes on the order of 16,000 to 24,000 hours and battery lifetimes of 4 to 5 years. A rough estimate of the potential domestic and global markets for stand-alone AC lighting systems is presented. DC current injection tests were performed on high-pressure sodium lamps and the test results are presented. Finally, a prototype system was designed and a prototype system controller (with battery charger and DC/AC inverter) was developed and built.

Voltage and capacity stability of the Hubble telescope nickel-hydrogen battery

Energy Technology Data Exchange (ETDEWEB)

Vaidyanathan, H. [Communications Satellite Corp., Clarksburg, MD (United States). COMSAT Labs.; Wajsgras, H. [NASA Goddard Space Flight Center, Greenbelt, MD (United States); Rao, G.M. [NASA Goddard Space Flight Center, Greenbelt, MD (United States)

1996-01-01

The power system of the Ubble Space Telescope includes two orbital replacement units, each containing three nickel-hydrogen (Ni-H{sub 2}) batteries of 88 Ah capacity. Since launch in April 1990, the batteries have completed 23 000 charge and discharge cycles and continue to meet the power demands of the satellite. The voltage, capacity, and pressure characteristics of all six batteries were analyzed to determine the state of health of the battery and to identify any signs of performance degradation. The battery pressures have changed to varying degrees. The end-of-charge pressure for battery 4 increased by 96 psi, while that for battery 3 decreased by 37 psi. The voltages of the individual cells show a decay rate of 0.69 mV per 1000 cycles, and the capacity of the batteries has apparently decreased, possibly due to the system being operated at a lower stage of charge. Autonomous battery operation involving charge termination at a preselected voltage continues to restore the energy dissipated during each orbit. The accumulated data on voltages and recharge ratios can be used to design new temperature-compensated voltage levels for similar missions that employ Ni-H{sub 2} batteries. (orig.)

Lead/acid batteries for photovoltaic applications. Test results and modelling

Energy Technology Data Exchange (ETDEWEB)

Copetti, J B [CIEMAT, Inst. de Energias Renovables, Madrid (Spain); Chenlo, F [CIEMAT, Inst. de Energias Renovables, Madrid (Spain)

1994-01-01

This work presents the results of experiments carried out on lead/acid batteries during charge and discharge processes at different currents and temperatures, selected to a cover a large range of operating conditions, including those encountered in photovoltaic (PV) system applications. The results allow us to verify the relations among the battery external parameters (voltage, current, state-of-charge and temperature), the behaviour of the internal resistance, and to deduce a model that represents the discharge and charge processes, including the overcharge. Finally, normalized equations with respect to the battery capacity are proposed, which allow us to fix the values of parameters and hence the model is valid for any type and size of lead/acid battery. (orig.)

Comparative study of a small size wind generation system efficiency for battery charging

Directory of Open Access Journals (Sweden)

Mayouf Messaoud

2013-01-01

Full Text Available This paper presents an energetic comparison between two control strategies of a small size wind generation system for battery charging. The output voltage of the direct drive PMSG is connected to the battery through a switch mode rectifier. A DC-DC boost converter is used to regulate the battery bank current in order to achieve maximum power from the wind. A maximum powertracking algorithm calculates the current command that corresponds to maximum power output of the turbine. The DC-DC converter uses this current to calculate the duty cycle witch is necessary to control the pulse width modulated (PWM active switching device (IGPT. The system overview and modeling are presented including characteristics of wind turbine, generator, batteries, power converter, control system, and supervisory system. A simulation of the system is performed using MATLAB/SIMULINK.

Carbon-enhanced VRLA batteries.

Energy Technology Data Exchange (ETDEWEB)

Enos, David George; Hund, Thomas D.; Shane, Rod (East Penn Manufacturing, Lyon Station, PA)

2010-10-01

The addition of certain forms of carbon to the negative plate in valve regulated lead acid (VRLA) batteries has been demonstrated to increase the cycle life of such batteries by an order of magnitude or more under high-rate, partial-state-of-charge operation. Such performance will provide a significant impact, and in some cases it will be an enabling feature for applications including hybrid electric vehicles, utility ancillary regulation services, wind farm energy smoothing, and solar photovoltaic energy smoothing. There is a critical need to understnd how the carbon interacts with the negative plate and achieves the aforementioned benefits at a fundamental level. Such an understanding will not only enable the performance of such batteries to be optimzied, but also to explore the feasibility of applying this technology to other battery chemistries. In partnership with the East Penn Manufacturing, Sandia will investigate the electrochemical function of the carbon and possibly identify improvements to its anti-sulfation properties. Shiomi, et al. (1997) discovered that the addition of carbon to the negative active material (NAM) substantially reduced PbSO{sub 4} accumulation in high rate, partial state of charge (HRPSoC) cycling applications. This improved performance with a minimal cost. Cycling applications that were uneconomical for traditional VRLA batteries are viable for the carbon enhanced VRLA. The overall goal of this work is to quantitatively define the role that carbon plays in the electrochemistry of a VRLA battery.

Enhanced closed loop State of Charge estimator for lithium-ion batteries based on Extended Kalman Filter

International Nuclear Information System (INIS)

Pérez, Gustavo; Garmendia, Maitane; Reynaud, Jean François; Crego, Jon; Viscarret, Unai

2015-01-01

Highlights: • Based on a general model valid in full range of SOC considering varied dynamics. • Integration of an accurate OCV model in EKF taking into account hysteresis effect. • Experimental validation with different current profiles: pulses, EV and lift. • Validated with specifically designed profile demanding accurate OCV modeling. - Abstract: The accurate State of Charge (SOC) estimation in a Li-ion battery requires a suitable model of the cell behavior. In this work an enhanced closed loop estimator based on Extended Kalman Filter (EKF) is proposed, considering a precise model of the cell dynamics valid for different current profiles and SOCs, and a complete model of the Open Circuit Voltage (OCV) which takes into account the hysteresis influence. The employed model and proposed estimator are validated with experimental results obtained from the response of a 40 Ah NMC Li-ion cell to several current profiles. These tests include current pulses, FUDS driving cycles, residential lift profiles, and specially designed profiles which demand an accurate modeling of the transitions between OCV boundaries. In each case, it is demonstrated that the enhanced model can reduce the estimation error nearly by half compared to an estimator ignoring the hysteresis effect. Furthermore, the good performance of the cell dynamics model allows an accurate and stable estimation over different conditions

The LiBH₄-LiI Solid Solution as an Electrolyte in an All-Solid-State Battery

DEFF Research Database (Denmark)

Sveinbjörnsson, Dadi Þorsteinn; Christiansen, Ane Sælland; Viskinde, Rasmus

2014-01-01

The charge and discharge performance of an all-solid-state lithium battery with the LiBH4-LiI solid solution as an electrolyte is reported. Lithium titanate (Li4Ti5O12) was used as the positive electrode and lithium metal as the negative electrode. The performance of the all-solid-state cell...

Monitoring and control system for the charging of batteries in photovoltaic applications; Sistema para monitorizar y controlar la carga de baterias en aplicaciones fotovoltaicas

Energy Technology Data Exchange (ETDEWEB)

Ortega S, Cesar A; Pacheco A, Maria Jojutla; Orozco V, Jaime A; Cristin V, Miguel A [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

2004-07-01

The appropriate monitoring and control of the charging of lead-acid (LAB) batteries is an increasing necessity in an industry that demands systems with low maintenance costs and high availability. The problem of extending the batteries useful life becomes more complex when the batteries are charged through photovoltaic panels. The purpose of the present article is to offer the description of the system for monitoring and control for the charging of batteries developed at the Instituto de Investigaciones Electricas (IIE). This system performs a continuous monitoring of the charging state of the battery and of the main operation parameters. With the extracted information of the data, the fine tuning algorithm control can be made. The data are acquired in a personal computer through a serial connection. Once stored, they are presented to the user in a graphical way so that they can be analyzed. [Spanish] El adecuado monitoreo y control de carga de baterias plomo-acido (BPA) es una necesidad creciente en una industria que demanda sistemas con bajos costos de mantenimiento y alta disponibilidad. El problema de extender la vida util de las baterias se vuelve mas complejo cuando las baterias son cargadas a traves de paneles fotovoltaicos. La intencion del presente articulo es ofrecer la descripcion del sistema para monitoreo y control de carga de baterias desarrollado en el Instituto de Investigaciones Electricas (IIE). Este sistema realiza un monitoreo continuo del estado de carga de la bateria y de los principales parametros de operacion. Con la informacion extraida de los datos, se puede hacer la sintonizacion fina del algoritmo de control. Los datos se adquieren en una computadora personal a traves de un enlace serial. Una vez almacenados, se presentan al usuario de manera grafica para que puedan ser analizados.

Electrode property of single-walled carbon nanotubes in all-solid-state lithium ion battery using polymer electrolyte

International Nuclear Information System (INIS)

Sakamoto, Y.; Ishii, Y.; Kawasaki, S.

2016-01-01

Electrode properties of single-walled carbon nanotubes (SWCNTs) in an all-solid-state lithium ion battery were investigated using poly-ethylene oxide (PEO) solid electrolyte. Charge-discharge curves of SWCNTs in the solid electrolyte cell were successfully observed. It was found that PEO electrolyte decomposes on the surface of SWCNTs.

Electrode property of single-walled carbon nanotubes in all-solid-state lithium ion battery using polymer electrolyte

Energy Technology Data Exchange (ETDEWEB)

Sakamoto, Y.; Ishii, Y.; Kawasaki, S., E-mail: kawasaki.shinji@nitech.ac.jp [Nagoya Institute of Technology, Gokiso, Showa, Nagoya, Aichi (Japan)

2016-07-06

Electrode properties of single-walled carbon nanotubes (SWCNTs) in an all-solid-state lithium ion battery were investigated using poly-ethylene oxide (PEO) solid electrolyte. Charge-discharge curves of SWCNTs in the solid electrolyte cell were successfully observed. It was found that PEO electrolyte decomposes on the surface of SWCNTs.

Cell overcharge testing inside sodium metal halide battery

Science.gov (United States)

Frutschy, Kris; Chatwin, Troy; Bull, Roger

2015-09-01

Testing was conducted to measure electrical performance and safety of the General Electric Durathon™ E620 battery module (600 V class 20 kWh) during cell overcharge. Data gathered from this test was consistent with SAE Electric Vehicle Battery Abuse Testing specification J2464 [1]. After cell overcharge failure and 24 A current flow for additional 60 minutes, battery was then discharged at 7.5 KW average power to 12% state of charge (SOC) and recharged back to 100% SOC. This overcharging test was performed on two cells. No hydrogen chloride (HCl) gas was detected during front cell (B1) test, and small amount (6.2 ppm peak) was measured outside the battery after center cell (F13) overcharge. An additional overcharge test was performed per UL Standard 1973 - Batteries for Use in Light Electric Rail (LER) Applications and Stationary Applications[2]. With the battery at 11% SOC and 280 °C float temperature, an individual cell near the front (D1) was deliberately imbalanced by charging it to 62% SOC. The battery was then recharged to 100% SOC. In all three tests, the battery cell pack was stable and individual cell failure did not propagate to other cells. Battery discharge performance, charge performance, and electrical isolation were normal after all three tests.

Low-charge-state linac

Energy Technology Data Exchange (ETDEWEB)

Shepard, K.W.; Kim, J.W.

1995-08-01

A design is being developed for a low-charge-state linac suitable for injecting ATLAS with a low-charge-state, radioactive beam. Initial work indicates that the existing ATLAS interdigital superconducting accelerating structures, together with the superconducting quadrupole transverse focussing element discussed above, provides a basis for a high-performance low-charge-state linac. The initial 2 or 3 MV of such a linac could be based on a normally-conducting, low-frequency RFQ, possibly combined with 24-MHz superconducting interdigital structures. Beam dynamics studies of the whole low-charge-state post-accelerator section were carried out in early FY 1995.

Quantifying TEMPO Redox Polymer Charge Transport toward the Organic Radical Battery.

Science.gov (United States)

Karlsson, Christoffer; Suga, Takeo; Nishide, Hiroyuki

2017-03-29

To design new and better organic active battery materials in a rational fashion, fundamental parameters of the charge transport must be studied. Herein we report on the electronic conductivity by electron diffusion in a TEMPO-containing redox polymer, and the reorganization energy of the TEMPO self-exchange in an organic solvent is determined for the first time. The electronic conductivity was 8.5 μS/cm at E 0 and corresponded to a redox hopping mechanism. The apparent electron diffusion coefficient was 1.9 × 10 -9 cm 2 /s at room temperature, and at short times the ion diffusion was limiting with a diffusion coefficient of 6.5 × 10 -10 cm 2 /s. The reorganization energy was determined to be 1.01 eV, indicating a rather polar chemical environment for the TEMPO groups. The implications for the usage of this type of materials in organic energy storage are discussed. As conductivity through 10 μm was demonstrated, we show that, if sufficient swellability can be ensured, charge can be transported through several micrometer thick layers in a battery electrode without any conducting additive.

Magnetic susceptibility as a direct measure of oxidation state in LiFePO4 batteries and cyclic water gas shift reactors.

Science.gov (United States)

Kadyk, Thomas; Eikerling, Michael

2015-08-14

The possibility of correlating the magnetic susceptibility to the oxidation state of the porous active mass in a chemical or electrochemical reactor was analyzed. The magnetic permeability was calculated using a hierarchical model of the reactor. This model was applied to two practical examples: LiFePO4 batteries, in which the oxidation state corresponds with the state-of-charge, and cyclic water gas shift reactors, in which the oxidation state corresponds to the depletion of the catalyst. In LiFePO4 batteries phase separation of the lithiated and delithiated phases in the LiFePO4 particles in the positive electrode gives rise to a hysteresis effect, i.e. the magnetic permeability depends on the history of the electrode. During fast charge or discharge, non-uniform lithium distributionin the electrode decreases the hysteresis effect. However, the overall sensitivity of the magnetic response to the state-of-charge lies in the range of 0.03%, which makes practical measurement challenging. In cyclic water gas shift reactors, the sensitivity is 4 orders of magnitude higher and without phase separation, no hysteresis occurs. This shows that the method is suitable for such reactors, in which large changes of the magnetic permeability of the active material occurs.

Assessment of the use of vanadium redox flow batteries for energy storage and fast charging of electric vehicles in gas stations

International Nuclear Information System (INIS)

Cunha, Álvaro; Brito, F.P.; Martins, Jorge; Rodrigues, Nuno; Monteiro, Vitor; Afonso, João L.; Ferreira, Paula

2016-01-01

A network of conveniently located fast charging stations is one of the possibilities to facilitate the adoption of Electric Vehicles (EVs). This paper assesses the use of fast charging stations for EVs in conjunction with VRFBs (Vanadium Redox Flow Batteries). These batteries are charged during low electricity demand periods and then supply electricity for the fast charging of EVs during day, thus implementing a power peak shaving process. Flow batteries have unique characteristics which make them especially attractive when compared with conventional batteries, such as their ability to decouple rated power from rated capacity, as well as their greater design flexibility and nearly unlimited life. Moreover, their liquid nature allows their installation inside deactivated underground gas tanks located at gas stations, enabling a smooth transition of gas stations' business model towards the emerging electric mobility paradigm. A project of a VRFB system to fast charge EVs taking advantage of existing gas stations infrastructures is presented. An energy and cost analysis of this concept is performed, which shows that, for the conditions tested, the project is technologically and economically viable, although being highly sensitive to the investment costs and to the electricity market conditions. - Highlights: • Assessment of Vanadium Redox Flow Battery use for EV fast charge in gas stations. • This novel system proposal allows power peak shaving and use of deactivated gas tanks. • Philosophy allows seamless business transition towards the Electric Mobility paradigm. • Project is technologically and economically viable, although with long payback times. • Future Cost cuts due to technology maturation will consolidate project attractiveness.

Simultaneous Determination of Electrochemical Impedance of Lithium-ion Rechargeable Batteries with Measurement of Charge-discharge Curves by Wavelet Transformation

International Nuclear Information System (INIS)

Itagaki, Masayuki; Ueno, Masaki; Hoshi, Yoshinao; Shitanda, Isao

2017-01-01

Highlights: • Wavelet transformation (WT) was used to obtain electrochemical impedance (EI) from time domain data. • Complex Morlet mother wavelet was employed to transform current and voltage time series from time domain to frequency domain. • An analytical method to determine EI of LIRB at arbitrary state of charge was proposed. • EI of LIRB was determined at arbitrary state of charge without stopping galvanostatic polarization for charge and discharge. - Abstract: A new analytical method was developed to determine the electrochemical impedance of lithium-ion rechargeable batteries (LIRB) at an arbitrary state of charge (SOC). Wavelet transformation (WT) is one of the waveform analysis methods, which allows the determination of frequency domain data as a function of time. The frequency domain data are obtained by convolution integral of a mother wavelet and original time domain data via the WT. A complex Morlet mother wavelet is used to obtain the complex number data in the frequency domain. The time series data of input current and output voltage signals are recorded by superimposing the double pulse current as an input signal to constant charge current for the charge of LIRB without stopping galvanostatic polarization. The double pulse current is composed of symmetrical positive and negative square waves. In this case, the SOC of LIRB is not affected by the input signal because the total amount of charge calculated from double pulse current is 0C. The impedance spectrum of LIRB at SOC 25% is determined in the frequency range from 0.1 to 100 Hz during charge/discharge cycles without stopping galvanostatic polarization for the charge/discharge.

Analysis of Pressure Variations in a Low-Pressure Nickel-Hydrogen Battery – Part 1

Science.gov (United States)

Purushothaman, B. K.; Wainright, J. S.

2012-01-01

A low pressure nickel-hydrogen battery using either a metal hydride or gaseous hydrogen for H2 storage has been developed for use in implantable neuroprosthetic devices. In this paper, pressure variations inside the cell for the gaseous hydrogen version are analyzed and correlated with oxygen evolution side reaction at the end of charging, the recombination of oxygen with hydrogen during charging and a subsequent rest period, and the self-discharge of the nickel electrode. About 70% of the recombination occurred simultaneously with oxygen evolution during charging and the remaining oxygen recombined with hydrogen during the 1st hour after charging. Self-discharge of the cell varies linearly with hydrogen pressure at a given state of charge and increased with increasing battery charge levels. The coulometric efficiency calculated based on analysis of the pressure-time data agreed well with the efficiency calculated based on the current-time data. Pressure variations in the battery are simulated accurately to predict coulometric efficiency and the state of charge of the cell, factors of extreme importance for a battery intended for implantation within the human body. PMID:22423175

Influence of expander components on the processes at the negative plates of lead-acid cells on high-rate partial-state-of-charge cycling. Part II. Effect of carbon additives on the processes of charge and discharge of negative plates

Energy Technology Data Exchange (ETDEWEB)

Pavlov, D.; Nikolov, P.; Rogachev, T. [Institute of Electrochemistry and Energy Systems, Bulgarian Academy of Sciences, Acad. Georgi Bonchev Street, bl. 10, Sofia 1113 (Bulgaria)

2010-07-15

Lead-acid batteries operated in the high-rate partial-state-of-charge (HRPSoC) duty rapidly lose capacity on cycling, because of sulfation of the negative plates. As the battery operates from a partially discharged state, the small PbSO{sub 4} crystals dissolve and precipitate onto the bigger crystals. The latter have low solubility and hence PbSO{sub 4} accumulates progressively in the negative plates causing capacity loss. In order to suppress this process, the rate of the charge process should be increased. In a previous publication of ours we have established that reduction of Pb{sup 2+} ions to Pb may proceed on the surface of both Pb and carbon black particles. Hence, the reversibility of the charge-discharge processes improves, which leads to improved cycle life performance of the batteries in the HRPSoC mode. However, not all carbon forms accelerate the charge processes. The present paper discusses the electrochemical properties of two groups of carbon blacks: Printex and active carbons. The influence of Vaniseprse A and BaSO{sub 4} (the other two components of the expander added to the negative plates) on the reversibility of the charge-discharge processes on the negative plates is also considered. It has been established that lignosulfonates are adsorbed onto the lead surface and retard charging of the battery. BaSO{sub 4} has the opposite effect, which improves the reversibility of the processes on cycling and hence prolongs battery life in the HRPSoC duty. It has been established that the cycle life of lead-acid cells depends on the type of carbon black or active carbon added to the negative plates. When the carbon particles are of nano-sizes (<180 nm), the HRPSoC cycle life is between 10,000 and 20,000 cycles. Lignosulfonates suppress this beneficial effect of carbon black and activated carbon additives to about 10,000 cycles. Cells with active carbons have the longest cycle life when they contain also BaSO{sub 4} but no lignosulfonate. A summary of

A Sepic Type Switched Mode Power Supply System For Battery Charging In An Electric Tricycle Auto-Rickshaw

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.

A method of computer modelling the lithium-ion batteries aging process based on the experimental characteristics

Science.gov (United States)

Czerepicki, A.; Koniak, M.

2017-06-01

The paper presents a method of modelling the processes of aging lithium-ion batteries, its implementation as a computer application and results for battery state estimation. Authors use previously developed behavioural battery model, which was built using battery operating characteristics obtained from the experiment. This model was implemented in the form of a computer program using a database to store battery characteristics. Batteries aging process is a new extended functionality of the model. Algorithm of computer simulation uses a real measurements of battery capacity as a function of the battery charge and discharge cycles number. Simulation allows to take into account the incomplete cycles of charge or discharge battery, which are characteristic for transport powered by electricity. The developed model was used to simulate the battery state estimation for different load profiles, obtained by measuring the movement of the selected means of transport.

OCV Hysteresis in Li-Ion Batteries including Two-Phase Transition Materials

Directory of Open Access Journals (Sweden)

Michael A. Roscher

2011-01-01

Full Text Available The relation between batteries' state of charge (SOC and open-circuit voltage (OCV is a specific feature of electrochemical energy storage devices. Especially NiMH batteries are well known to exhibit OCV hysteresis, and also several kinds of lithium-ion batteries show OCV hysteresis, which can be critical for reliable state estimation issues. Electrode potential hysteresis is known to result from thermodynamical entropic effects, mechanical stress, and microscopic distortions within the active electrode materials which perform a two-phase transition during lithium insertion/extraction. Hence, some Li-ion cells including two-phase transition active materials show pronounced hysteresis referring to their open-circuit voltage. This work points out how macroscopic effects, that is, diffusion limitations, superimpose the latte- mentioned microscopic mechanisms and lead to a shrinkage of OCV hysteresis, if cells are loaded with high current rates. To validate the mentioned interaction, Li-ion cells' state of charge is adjusted to 50% with various current rates, beginning from the fully charged and the discharged state, respectively. As a pronounced difference remains between the OCV after charge and discharge adjustment, obviously the hysteresis vanishes as the target SOC is adjusted with very high current rate.

Battery Monitoring and Charging System

National Research Council Canada - National Science Library

Thivierge, Daniel P

2007-01-01

A battery monitoring device for a battery having cells grouped in modules. The device includes a monitoring circuit for each module which monitors the voltage in each cell and the overall module voltage...

Non-Destructive Monitoring of Charge-Discharge Cycles on Lithium Ion Batteries using 7Li Stray-Field Imaging

Science.gov (United States)

Tang, Joel A.; Dugar, Sneha; Zhong, Guiming; Dalal, Naresh S.; Zheng, Jim P.; Yang, Yong; Fu, Riqiang

2013-01-01

Magnetic resonance imaging provides a noninvasive method for in situ monitoring of electrochemical processes involved in charge/discharge cycling of batteries. Determining how the electrochemical processes become irreversible, ultimately resulting in degraded battery performance, will aid in developing new battery materials and designing better batteries. Here we introduce the use of an alternative in situ diagnostic tool to monitor the electrochemical processes. Utilizing a very large field-gradient in the fringe field of a magnet, stray-field-imaging (STRAFI) technique significantly improves the image resolution. These STRAFI images enable the real time monitoring of the electrodes at a micron level. It is demonstrated by two prototype half-cells, graphite∥Li and LiFePO4∥Li, that the high-resolution 7Li STRAFI profiles allow one to visualize in situ Li-ions transfer between the electrodes during charge/discharge cyclings as well as the formation and changes of irreversible microstructures of the Li components, and particularly reveal a non-uniform Li-ion distribution in the graphite. PMID:24005580

A Review of Approaches for the Design of Li-Ion BMS Estimation Functions Revue de différentes approches pour l’estimation de l’état de charge de batteries Li-ion

Directory of Open Access Journals (Sweden)

Di Domenico D.

2013-02-01

Full Text Available This paper aims at comparing different approaches for the estimation of the state of charge of lithium-ion batteries. The main advantages as well as the critical points of the considered techniques are analyzed, highlighting the impact of the cell model precision and complexity on the estimator performance. Among others, the electrical equivalent circuit based technique is selected for further development. The results of a complete procedure from the cell characterization to the online estimation are illustrated. The experimental tests based on the data collected on batteries testing facilities of IFP Energies nouvelles show that the proposed strategy allows a satisfying state of charge real time estimation. Cet article vise à comparer différentes approches pour l’estimation de l’état de charge pour les batteries Li-ion. Les principaux avantages ainsi que les points critiques des différentes techniques sont analysés, en soulignant l’impact de la complexité et de la précision du modèle sur les performances de l’estimateur. La procédure complète, allant de la caractérisation de la cellule jusqu’à l’estimation en ligne de l’état de charge, est présentée pour la modélisation par circuit électrique équivalent. Les tests expérimentaux sur la base des données acquises au laboratoire batteries d’IFP Energies nouvelles montrent que cette stratégie permet d’obtenir un estimateur en temps réel de l’état de charge présentant de bonnes performances.

Effects of lead-foam grids on performance of VRLA battery

Energy Technology Data Exchange (ETDEWEB)

Dai, Changsong; Yi, Tingfeng; Wang, Dianlong; Hu, Xinguo [Department of Applied Chemistry, Harbin Institute of Technology, P.O. Box 411, Harbin 150001 (China)

2006-08-25

Lead-foam grids have been prepared by electrodepositing lead on a copper-foam substrate that has good conductibility and a symmetrically three-dimensional reticulated structure. VRLA batteries with lead foam as the negative electrode current collector material have been fabricated; the effects of the lead foam on the specific capacity, the active material utilization efficiency and the negative active material transformation process of the VRLA batteries have been studied. The results show that a lead-foam grid has a bigger specific surface area than a cast grid. The charge voltage of a VRLA battery with a lead-foam negative electrode is significantly lower than that of a VRLA battery with a cast grid electrode during a charge process. The discharge capacity, the mass specific capacity, and the active material utilization efficiency of a VRLA battery with a lead-foam electrode can be greatly improved at different states of discharge. The EIS research revealed that a lead-foam negative electrode has higher electrochemical reactivity. Observed by means of a scanning electron microscope, it was found that the spongy Pb crystals at a lead-foam grid negative electrode are smaller than that of a cast grid negative electrode at a state of charge; while the PbSO{sub 4} crystals are smaller than that of a cast grid negative electrode at a state of discharge. (author)

Online Reliable Peak Charge/Discharge Power Estimation of Series-Connected Lithium-Ion Battery Packs

Directory of Open Access Journals (Sweden)

Bo Jiang

2017-03-01

Full Text Available The accurate peak power estimation of a battery pack is essential to the power-train control of electric vehicles (EVs. It helps to evaluate the maximum charge and discharge capability of the battery system, and thus to optimally control the power-train system to meet the requirement of acceleration, gradient climbing and regenerative braking while achieving a high energy efficiency. A novel online peak power estimation method for series-connected lithium-ion battery packs is proposed, which considers the influence of cell difference on the peak power of the battery packs. A new parameter identification algorithm based on adaptive ratio vectors is designed to online identify the parameters of each individual cell in a series-connected battery pack. The ratio vectors reflecting cell difference are deduced strictly based on the analysis of battery characteristics. Based on the online parameter identification, the peak power estimation considering cell difference is further developed. Some validation experiments in different battery aging conditions and with different current profiles have been implemented to verify the proposed method. The results indicate that the ratio vector-based identification algorithm can achieve the same accuracy as the repetitive RLS (recursive least squares based identification while evidently reducing the computation cost, and the proposed peak power estimation method is more effective and reliable for series-connected battery packs due to the consideration of cell difference.

Prospects and Limits of Energy Storage in Batteries.

Science.gov (United States)

Abraham, K M

2015-03-05

Energy densities of Li ion batteries, limited by the capacities of cathode materials, must increase by a factor of 2 or more to give all-electric automobiles a 300 mile driving range on a single charge. Battery chemical couples with very low equivalent weights have to be sought to produce such batteries. Advanced Li ion batteries may not be able to meet this challenge in the near term. The state-of-the-art of Li ion batteries is discussed, and the challenges of developing ultrahigh energy density rechargeable batteries are identified. Examples of ultrahigh energy density battery chemical couples include Li/O2, Li/S, Li/metal halide, and Li/metal oxide systems. Future efforts are also expected to involve all-solid-state batteries with performance similar to their liquid electrolyte counterparts, biodegradable batteries to address environmental challenges, and low-cost long cycle-life batteries for large-scale energy storage. Ultimately, energy densities of electrochemical energy storage systems are limited by chemistry constraints.

Further demonstration of the VRLA-type UltraBattery under medium-HEV duty and development of the flooded-type UltraBattery for micro-HEV applications

Energy Technology Data Exchange (ETDEWEB)

Furukawa, J.; Takada, T.; Monma, D. [The Furukawa Battery Co., Ltd., R and D Division, 23-6 Kuidesaku, Shimofunao-machi, Joban, Iwaki-city, 972-8501 (Japan); Lam, L.T. [CSIRO Energy Technology, Bayview Avenue, Clayton South, Vic. 3169 (Australia)

2010-02-15

The UltraBattery has been invented by the CSIRO Energy Technology in Australia and has been developed and produced by the Furukawa Battery Co., Ltd., Japan. This battery is a hybrid energy storage device which combines a super capacitor and a lead-acid battery in single unit cells, taking the best from both technologies without the need of extra, expensive electronic controls. The capacitor enhances the power and lifespan of the lead-acid battery as it acts as a buffer during high-rate discharging and charging, thus enabling it to provide and absorb charge rapidly during vehicle acceleration and braking. The laboratory results of the prototype valve-regulated UltraBatteries show that the capacity, power, available energy, cold cranking and self-discharge of these batteries have met, or exceeded, all the respective performance targets set for both minimum and maximum power-assist HEVs. The cycling performance of the UltraBatteries under micro-, mild- and full-HEV duties is at least four times longer than that of the state-of-the-art lead-acid batteries. Importantly, the cycling performance of UltraBatteries is proven to be comparable or even better than that of the Ni-MH cells. On the other hand, the field trial of UltraBatteries in the Honda Insight HEV shows that the vehicle has surpassed 170,000 km and the batteries are still in a healthy condition. Furthermore, the UltraBatteries demonstrate very good acceptance of the charge from regenerative braking even at high state-of-charge, e.g., 70% during driving. Therefore, no equalization charge is required for the UltraBatteries during field trial. The HEV powered by UltraBatteries gives slightly higher fuel consumption (cf., 4.16 with 4.05 L/100 km) and CO{sub 2} emissions (cf., 98.8 with 96 g km{sup -1}) compared with that by Ni-MH cells. There are no differences in driving experience between the Honda Insight powered by UltraBatteries and by Ni-MH cells. Given such comparable performance, the UltraBattery pack

Optimization of batteries for plug-in hybrid electric vehicles

Science.gov (United States)

English, Jeffrey Robb

This thesis presents a method to quickly determine the optimal battery for an electric vehicle given a set of vehicle characteristics and desired performance metrics. The model is based on four independent design variables: cell count, cell capacity, state-of-charge window, and battery chemistry. Performance is measured in seven categories: cost, all-electric range, maximum speed, acceleration, battery lifetime, lifetime greenhouse gas emissions, and charging time. The performance of each battery is weighted according to a user-defined objective function to determine its overall fitness. The model is informed by a series of battery tests performed on scaled-down battery samples. Seven battery chemistries were tested for capacity at different discharge rates, maximum output power at different charge levels, and performance in a real-world automotive duty cycle. The results of these tests enable a prediction of the performance of the battery in an automobile. Testing was performed at both room temperature and low temperature to investigate the effects of battery temperature on operation. The testing highlighted differences in behavior between lithium, nickel, and lead based batteries. Battery performance decreased with temperature across all samples with the largest effect on nickel-based chemistries. Output power also decreased with lead acid batteries being the least affected by temperature. Lithium-ion batteries were found to be highly efficient (>95%) under a vehicular duty cycle; nickel and lead batteries have greater losses. Low temperatures hindered battery performance and resulted in accelerated failure in several samples. Lead acid, lead tin, and lithium nickel alloy batteries were unable to complete the low temperature testing regime without losing significant capacity and power capability. This is a concern for their applicability in electric vehicles intended for cold climates which have to maintain battery temperature during long periods of inactivity

Rapid hydrogen charging on metal hydride negative electrode of Fuel Cell/Battery (FCB) systems

Energy Technology Data Exchange (ETDEWEB)

Choi, Bokkyu; Lee, Sunmook; Kawai, Hiroyuki; Fushimi, Chihiro; Tsutsumi, Atsushi [Collaborative Research Center for Energy Engineering, Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505 (Japan)

2009-02-15

The characteristics of rapid gaseous H{sub 2} charging/electrochemical discharging of the metal hydride negative electrode were investigated for the application in Fuel Cell/Battery (FCB) systems. They were evaluated with the H{sub 2} gas absorption, followed by the subsequent electrochemical discharging in the electrolyte solution (6M KOH). Then, the cyclability of charge-discharge was also examined. It was observed that more than 70% of the theoretical capacity was charged within 10 min with 0.3 MPa and 0.5 MPa of the initial H{sub 2} pressures. The electrochemical discharge curve showed that more than 86% of the absorbed H{sub 2} was discharged. Furthermore, the cycled charge-discharge process indicated that the H{sub 2} gas charge and electrochemical discharge process is an effective way to rapidly charge and activate the metal hydride without degeneration. (author)

Advanced state prediction of lithium-ion traction batteries in hybrid and battery electric vehicle applications

Energy Technology Data Exchange (ETDEWEB)

Jadidi, Yasser

2011-07-01

Automotive power trains with high energy efficiencies - particularly to be found in battery and hybrid electric vehicles - find increasing attention in the focus of reduction of exhaust emissions and increase of mileage. The underlying concept, the electrification of the power train, is subject to the traction battery and its battery management system since the capability of the battery permits and restricts electric propulsion. Consequently, the overall vehicle efficiency and in particular the operation strategy performance strongly depends on the quality of information about the battery. Besides battery technology, the key challenges are given by both the accurate prediction of battery behaviour and the electrochemical battery degradation that leads to power and capacity fade of the traction battery. This book provides the methodology for development of a battery state monitoring and prediction algorithm for application in a battery management system that accounts for the effects of electrochemical degradation. (orig.)

Exploring the Model Design Space for Battery Health Management

Science.gov (United States)

Saha, Bhaskar; Quach, Cuong Chi; Goebel, Kai Frank

2011-01-01

Battery Health Management (BHM) is a core enabling technology for the success and widespread adoption of the emerging electric vehicles of today. Although battery chemistries have been studied in detail in literature, an accurate run-time battery life prediction algorithm has eluded us. Current reliability-based techniques are insufficient to manage the use of such batteries when they are an active power source with frequently varying loads in uncertain environments. The amount of usable charge of a battery for a given discharge profile is not only dependent on the starting state-of-charge (SOC), but also other factors like battery health and the discharge or load profile imposed. This paper presents a Particle Filter (PF) based BHM framework with plug-and-play modules for battery models and uncertainty management. The batteries are modeled at three different levels of granularity with associated uncertainty distributions, encoding the basic electrochemical processes of a Lithium-polymer battery. The effects of different choices in the model design space are explored in the context of prediction performance in an electric unmanned aerial vehicle (UAV) application with emulated flight profiles.

Impact of battery weight and charging patterns on the economic and environmental benefits of plug-in hybrid vehicles

International Nuclear Information System (INIS)

Shiau, Ching-Shin Norman; Samaras, Constantine; Hauffe, Richard; Michalek, Jeremy J.

2009-01-01

Plug-in hybrid electric vehicle (PHEV) technology is receiving attention as an approach to reducing US dependency on foreign oil and greenhouse gas (GHG) emissions from the transportation sector. PHEVs require large batteries for energy storage, which affect vehicle cost, weight, and performance. We construct PHEV simulation models to account for the effects of additional batteries on fuel consumption, cost, and GHG emissions over a range of charging frequencies (distance traveled between charges). We find that when charged frequently, every 20 miles or less, using average US electricity, small-capacity PHEVs are less expensive and release fewer GHGs than hybrid electric vehicles (HEVs) or conventional vehicles. For moderate charging intervals of 20-100 miles, PHEVs release fewer GHGs, but HEVs have lower lifetime costs. High fuel prices, low-cost batteries, or high carbon taxes combined with low-carbon electricity generation would make small-capacity PHEVs cost competitive for a wide range of drivers. In contrast, increased battery specific energy or carbon taxes without decarbonization of the electricity grid would have limited impact. Large-capacity PHEVs sized for 40 or more miles of electric-only travel do not offer the lowest lifetime cost in any scenario, although they could minimize GHG emissions for some drivers and provide potential to shift air pollutant emissions away from population centers. The tradeoffs identified in this analysis can provide a space for vehicle manufacturers, policymakers, and the public to identify optimal decisions for PHEV design, policy and use. Given the alignment of economic, environmental, and national security objectives, policies aimed at putting PHEVs on the road will likely be most effective if they focus on adoption of small-capacity PHEVs by urban drivers who can charge frequently.

Technical and legal considerations and solutions in the area of battery charging for electric vehicles

Science.gov (United States)

Juda, Z.

2016-09-01

The issue of protecting health of residents of urbanized areas from the effect of excessive particulate matter and toxic components of car exhaust gases imposes the need of introduction of clean electric vehicles to the market. The increasing market availability of electric vehicles, especially in the segment of short-range (neighborhood) vehicles is followed by development of new and advanced infrastructure solutions. This also applies to the increasingly popular hybrid vehicles PHEV (Plug-in Hybrid Electric Vehicles). However, problems with the existing designs are primarily associated with limited driving range on a single battery charge, the density of charging stations in urban and suburban area, energy system efficiency due to increased electricity demand and the unification of solutions for charging stations, on-board chargers and the necessary accessories. Technical solutions are dependent on many factors, including the type and size of battery in the vehicle and access to power grid with increased load capacity. The article discusses the legal and technical actions outlined in the above directions. It shows the available and planned solutions in this area.

Control oriented 1D electrochemical model of lithium ion battery

International Nuclear Information System (INIS)

Smith, Kandler A.; Rahn, Christopher D.; Wang, Chao-Yang

2007-01-01

Lithium ion (Li-ion) batteries provide high energy and power density energy storage for diverse applications ranging from cell phones to hybrid electric vehicles (HEVs). For efficient and reliable systems integration, low order dynamic battery models are needed. This paper introduces a general method to generate numerically a fully observable/controllable state variable model from electrochemical kinetic, species and charge partial differential equations that govern the discharge/charge behavior of a Li-ion battery. Validated against a 313th order nonlinear CFD model of a 6 Ah HEV cell, a 12th order state variable model predicts terminal voltage to within 1% for pulse and constant current profiles at rates up to 50 C. The state equation is constructed in modal form with constant negative real eigenvalues distributed in frequency space from 0 to 10 Hz. Open circuit potential, electrode surface concentration/reaction distribution coupling and electrolyte concentration/ionic conductivity nonlinearities are explicitly approximated in the model output equation on a local, electrode-averaged and distributed basis, respectively. The balanced realization controllability/observability gramian indicates that the fast electrode surface concentration dynamics are more observable/controllable than the electrode bulk concentration dynamics (i.e. state of charge)

The testing of batteries linked to supercapacitors with electrochemical impedance spectroscopy: A comparison between Li-ion and valve regulated lead acid batteries

Science.gov (United States)

Ferg, Ernst; Rossouw, Claire; Loyson, Peter

2013-03-01

For electric vehicles, a supercapacitor can be coupled to the electrical system in order to increase and optimize the energy and power densities of the drive system during acceleration and regenerative breaking. This study looked at the charge acceptance and maximum discharge ability of a valve regulated lead acid (VRLA) and a Li-ion battery connected in parallel to supercapacitors. The test procedure evaluated the advantage of using a supercapacitor at a 2 F:1 Ah ratio with the battery types at various states of charge (SoC). The results showed that about 7% of extra charge was achieved over a 5-s test time for a Li-ion hybrid system at 20% SoC, whereas at the 80% SoC the additional capacity was approximately 16%. While for the VRLA battery hybrid system, an additional charge of up to 20% was achieved when the battery was at 80% SoC, with little or no benefit at the 20% SoC. The advantage of the supercapacitor in parallel with a VRLA battery was noticeable on its discharge ability, where significant extra capacity was achieved for short periods of time for a battery at the 60% and 40% SoC when compared to the Li-ion hybrid system. The study also made use of Electrochemical Impedance Spectroscopy (EIS) with a suitable equivalent circuit model to explain, in particular, the internal resistance and capacitance differences observed between the different battery chemistries with and without a supercapacitor.

About the Territorial Potential of the Construction of Battery-Charging Stations for Autonomous Electric Motor Vehicles in the Regions

Directory of Open Access Journals (Sweden)

Shilova Lyubov

2016-01-01

Full Text Available The article describes the main current trends in the development of electric motor vehicles with "zero emission" as well as the battery-charging stations concerned. The study is based on a preliminary comparative analysis of the RF regions with respect to five indices (average per capita income, number of private cars in the region, air pollution level, provision of the region with power supply and the potential use of local renewable energy resources, and it gives some recommendations on the prospects of possible construction of battery-charging stations in the regions.

Behavior Patterns, Origin of Problems and Solutions Regarding Hysteresis Phenomena in Complex Battery Systems

DEFF Research Database (Denmark)

Khan, Mohammad Rezwan; Barreras, Jorge Varela; Stan, Ana-Irina

2014-01-01

. Therefore, an accurate knowledge of the hysteresis of OCV is vital for various applications and battery models. This is because currently Battery Management Systems (BMS) use the well-defined OCV-SoC representative curve for SoC estimation and power prediction. Particularly lithium-ion batteries with iron......One of the common phenomenona for most of the battery cell chemistries is hysteresis. Since an open circuit voltage (OCV) path is not identical for the charge and discharge of the battery cell at different states of charge (SoC) level, the battery cells show the hysteresis effect. Usually, the OCV...... i.e. voltage with zero current after previous charge is higher than the OCV after discharge at the same SoC level. It embodies the hysteresis of the battery cell. The OCV is principally subjected to previous operating condition and cannot be taken as self-regulating from the operating history...

Experimental and Computational Approaches to Interfacial Resistance in Solid-State Batteries

Energy Technology Data Exchange (ETDEWEB)

Takada, Kazunori, E-mail: takada.kazunori@nims.go.jp [Battery Materials Unit, National Institute for Materials Science, Tsukuba (Japan); Global Research Center for Environment and Energy Based on Nanomaterials Science, National Institute for Materials Science, Tsukuba (Japan); Ohno, Takahisa [Global Research Center for Environment and Energy Based on Nanomaterials Science, National Institute for Materials Science, Tsukuba (Japan); Computational Materials Science Unit, National Institute for Materials Science, Tsukuba (Japan)

2016-03-30

Solid-state batteries with inorganic solid electrolytes are expected to be an efficient solution to the issues of current lithium-ion batteries that are originated from their organic-solvent electrolytes. Although solid-state batteries had been suffering from low rate capability due to low ionic conductivities of solid electrolytes, some sulfide solid electrolytes exhibiting high ionic conductivity of the order of 10{sup −2} S cm{sup −1} have been recently developed. Since the conductivity is comparable to or even higher than that of liquid electrolytes, when taking the transport number of unity into account, ion transport in solid electrolytes has ceased from rate determination; however, it has been replaced by that across interfaces. The sulfide electrolytes show high interfacial resistance to the high-voltage cathodes. Our previous studies have demonstrated that oxide solid electrolytes interposed at the interface reduce the resistance, and they also suggest that the high resistance is attributable to a lithium-depleted layer formed at the interface. This study employs the first-principles calculation in order to gain insight into the interface. The interface structure between an oxide cathode/sulfide electrolyte simulated by the first-principles molecular dynamics has disclosed the presence of lithium-depleted layer at the interface, and the electronic structure calculated on the basis of density functional theory strongly suggests that the charge current preferentially removes lithium ions from the sulfide electrolyte side of the interface to deplete the lithium ion there. These calculation results are consistent with the transport mechanism proposed from the experimental results.