A Power Electronic Starter Motor Emulator for Investigating Battery Behaviour

This paper is concerned with the design, implementation and testing of a power electronic starter motor emulator for investigating starter motor impact on lead-acid based batteries. A programmable load circuit topology is developed in to generate the cranking load profile of the starter motor. Cranking current waveform profile of a 1. 2L Fiat Punto was measured and was used for the study. Further two cranking waveforms were generated from the measured waveform by varying the second peak, trough and waveform period of the of the original load waveform. Measurement systems were also incorporated to monitor the device's thermal stability as well as various battery parameters. The key findings of the work suggest that the peak current magnitude is a contributing factor in degrading battery state of health. Furthermore, a resistive strain ratio within the starter motor waveform is found to be related to battery failure. The emulator proved to be highly robust, sustaining over 25 000 discharge waveforms. The emulator achieved a peak current of 386 A and can dissipate 220W at 75°C.