An Adaptive Event-Triggered Distributed PID Control for State of Charge Balancing of Multiple Batteries Based Electric Vehicles

This work designs a distributed proportional-integral-derivative (PID) controller integrated with the adaptive event-triggered (AET) mechanism to cope with the state of charge (SoC) balancing issue while ensuring the stability of the voltage of DC bus in multiple batteries based electric vehicles (EVs). The SoC balancing is realized by the distributed PID controller in the multiple bidirectional DC-DC converter buck-boost circuit, so that the battery with the high SoC value releases more energy and absorbs less energy, and the battery with low SoC absorbs more energy and releases less energy. Meanwhile, the adaptive eventtriggered strategy configured with each battery proposed in this work can adjust the release threshold according to the deviation of each SoC from the average value, which can greatly reduce unnecessary waste of communication resources while achieving SoC balancing. A three-battery based EVs with time-varying operating mode is simulated to verify the effectiveness of the designed approach.