Design and implementation of a parametric battery emulator based on a power converter

Abstract

Real batteries used for the performance testing and evaluation of the drive systems of electric vehicles (EVs) are being replaced by battery emulators (BEs) because of the high test costs, long test cycles, and difficulty in adapting to extreme operating conditions associated with the use of real batteries. A parametric BE for a lithium-ion battery based on a voltage source converter is presented. First, a Thevenin model of the battery is established, and a parameter identification method is proposed to obtain the relationship between the parameters of the battery model and the characteristics of the external electrical port (i.e. I–V characteristics) of the battery. Subsequently, based on the I–V characteristics, the topological structure of the power electronic device of the BE is designed, and the working modes under charging and discharging conditions are presented. Finally, an experimental prototype of the BE is designed and tested. The experimental results show that the proposed BE power converter can successfully simulate the external port voltage and current characteristics of the battery, which can replace the real battery to provide an effective test environment for the test and evaluation of the electric drive system of EVs.