Research On Application Of High-Power Battery Testing Device

High-power battery plays a certain buffering role when all kinds of new energy power generation are connected to the grid.When using battery prototype to build an experimental platform for research,it will cost a lot of money to buy and maintain batteries,and there will be potential safety hazards when conducting experiments under extreme working conditions.Therefore,it is of certain significance to use high-power battery testing device instead of battery prototype for research.At present,the research of high-power battery testing device in China is still in the initial stage.On the one hand,the battery model is too simple to simulate the external characteristics of the battery,or the battery model is too complex to realize.On the other hand,the topology can only simulate the charging or discharging of a single battery,and the power output is too small to limit the number of simulated batteries.In order to solve the above problems,this paper proposes a high-power battery test device,and the battery model adopts the second-order RC equivalent model to solve the battery model problem.The topology structure of three-phase PWM rectifier +DC/DC is designed to solve the problems of non-bidirectional flow of topological energy and too small power output.The details are as follows:In order to obtain a battery model with moderate complexity that can simulate the external characteristics of the battery,this paper establishes a second-order RC equivalent model by consulting the data,and then verifies the second-order RC equivalent model by using MATLAB/Simulink,and completes the parameter identification of the second-order RC equivalent model by using the least square method.At the same time,the measured data are compared with the data after parameter identification,and the error between the simulation results and the measured data is within 0.15 V,which verifies the accuracy of the battery model.In order to obtain a circuit topology with bidirectional energy flow and a wide power output range,the front stage of the high-power battery test device designed in this paper adopts a three-phase voltage-source PWM rectifier circuit,which can work in the rectifier or inverter state to realize bidirectional energy flow,and the DC side can stably output 800 V voltage.In the latter stage,four-phase staggered DC/DC circuit is used to realize the battery simulation function,and the energy can flow in two directions,and the power output range is 24V-800 V.Then MATLAB/Simulink is used to build a simulation to verify the correctness of the control method and topology.Finally,the experimental platform of high-power battery testing device was built,and the battery load switching and battery constant current charging and discharging experiments were carried out respectively.The experimental results show that the designed high-power battery test device can flow in both directions,the output power can be increased to 300 k W,and the output error of the simulated battery is within0.15 V V.Compared with the traditional battery simulation power supply,the accuracy and performance are improved.The research results of this paper have practical significance for accelerating the research of batteries.Fig [60] Table [7] Reference [83]...