Power battery impedance spectrum test technology based on current pulse excitation and frequency spectrum analysis

This paper provides a method and a system based on current pulse excitation and frequency spectrum analysis, which can complete battery impedance spectrum test and analysis. By exerting current excitation onto the battery, synchronously measuring current excitation and terminal voltage response, we count the amplitude spectrum and phase spectrum for current excitation and terminal voltage response under different frequencies. Also, we count the battery impedance under different frequencies according to spectrums of I and U, to get the complete spectrogram for the battery impedance. The technology provides a new solution for calculating and predicting the charge state and health state of the storage battery.

I. Introduction

In recent years, it has been widely recognized by the western countries to conduct simple and quick test the SOC (State of charge) and SOH (State of health) of the battery with internal resistance/conductivity test technology. The technology has been listed as the test standard for VRLA by IEEE.