Simulation Study of Power Transfer Efficiency in Non-Isolated Buck-Boost Bidirectional Converter for Electric Vehicle

This paper presents a simulation study of a non-isolated buck-boost bidirectional converter system that integrates electric vehicles (EV) and energy storage systems (ESS). The study evaluates the converter's efficiency in charging and discharging modes for EVs using a Proportional-Integral (PI) control algorithm. Simulations reveal that the converter achieves peak efficiency above 90% between 20 kW and 30 kW, with efficiency stabilizing near 98% at higher switching frequencies above 10 kHz until 100 kHz. Additionally, the converter operates optimally at a maximum voltage of 450 V, where efficiency remains close to 90%. SOC dynamics during mode 1 shows a 0.25% increase in EV SOC and a 0.1 % decrease in ESS SOC over 10 seconds. On the other hand, mode 2 shows a 0.18% increase in ESS SOC and a 0.5% decrease in EV SOC. These results demonstrate the converter's high efficiency and stable power transfer capabilities, making it a suitable solution for reliable energy management in EV and ESS integration.