Research And Design Of Power Battery Simulator

Today,the problem of environmental pollution caused by fuel vehicles is becoming increasingly serious,and the fossil energy is drying up.The research of new energy vehicles has been paid more and more attention.Power lithium-ion battery as a new energy vehicle core components,but directly to its test,there is a long charging time,low efficiency,high cost.To this end,must be designed to replace the power battery pack of high-precision analog devices.Firstly,the background and significance of the research are expounded,and the research status of the battery simulator is introduced in detail.In order to establish an accurate battery model,aiming at the inherent performance parameters,the open circuit voltage(OCV)and the state of charge(SOC),the charge and discharge work of the lithium battery was selected as the research object.Characteristics and second-order RC physical equivalent model.According to SOC and battery ohmic resistance,OCV,polarization resistance,the relationship between the polarization capacitance,and the use of SOC as OCV and second-order equivalent resistance of the control variables,to establish a dynamic characteristics of the battery with the battery effective model.Simulink software is used to simulate the equivalent model,and compared with the experimental data,verify the accuracy of the established battery simulator.Secondly,the hardware design scheme of the battery simulator is put forward from the dynamic characteristics of the battery and the relevant parameters.In this paper,the main circuit uses two-way DC-DC topology,the system according to the battery equivalent circuit model to provide reference voltage,to achieve the dynamic characteristics of the battery simulation.The voltage output of the system is controlled by introducing the voltage outer ring so that the circuit output voltage can be changed according to the battery charging characteristic curve.At the same time,the working principle of bi-directional DC-DC topology is analyzed,and the equivalent mathematical model is established by using the state space averaging method.According to the system characteristics,the frequency function is used to adjust the transfer function in series to make the system maintain good dynamic and static characteristics.The implementation of control strategy adopts the model-based software design method.By establishing the Simulink algorithm model,the control algorithm and the code are unified,thus speeding up the design process of the system.Finally,the data acquisition system of the battery simulator based on Lab VIEW is designed.The prototype is charged and discharged,and compared with the actual battery test results.From the comparison results,the test results of the battery simulator is similar as the actual results,it proves that the experimental study,theoretical analysis,simulation modeling and other methods of correctness,in order to further develop a more fully functional battery simulation Device laid the foundation.