High current battery impedance testing for power electronics circuit design

Abstract

In hybrid electric vehicles, the operation of the power electronics circuits usually generates great amount of switching frequency related current ripple. This current ripple would be absorbed by both the battery and the passive components at the front end of the power electronics circuits. The amount of the current ripple that goes into the battery is largely decided by the battery impedance. So, in this paper, a high power converter based impedance tester and an impedance test of nickel-metal hydride (NiMH) battery at power converter switching frequency with high DC offset current are presented. The test method and test platform introduced in this paper can also be used for other different types of batteries, ultra capacitors, fuel cells, and as well as photovoltaic modules.