A Simplified Equivalent Circuit Model of Magnesium-air Batteries Used with Power Converters

Abstract

This paper proposes a simplified equivalent circuit model of magnesium-air batteries focusing on the frequency characteristics from 0.1 Hz to 100 kHz for magnesium-air batteries used as a power source in power converters. The proposed simplified equivalent circuit model has fewer circuit elements than the conventional models, so the identification of each circuit parameter can be calculated from the frequency characteristics without trial-and-error fitting. The frequency characteristics of the magnesium-air batteries were measured using an impedance analyzer IM3590. The circuit parameters of the equivalent circuit model were identified from the measured frequency characteristics, and the voltage-current response characteristics under load fluctuation were simulated by a circuit simulator PSIM using the identified circuit parameters. A comparison of simulation and experimental results shows that the proposed simplified equivalent circuit model reproduces the voltage and current characteristics of the magnesium-air batteries under load fluctuations and its usefulness.