An Active Stabilization Control Strategy for DC- DC Converter Feeding Constant Power Load in Electric Vehicle

摘要

In order to improve the drive system efficiency in electric vehicles, boost converter which added between the battery and the voltage source inverters (VSI) is proposed and widly used. Traditional dual-loop control system with current feed-forward compensation for the boost converter is presented, where the small-signal model of the system shows that a large DC-link capacitor is nessassary to matain the DC-link voltage stability. Meanwhile, this method always leads to power density reduction of the drive system. In this paper, an improved control strategy is proposed which can achieve a better DC-link voltage stability even with a small DC-link capacitor. Using the optimal control strategy, the equivalent capacitance value of the DC-link capacitor can be improved. Bassed on MATLAB, the PMSM drive system in electric vehicles (EV) is modeled. One of the typical operation conditions in EV is simulated with both control strategies, the results of the comparison show that the proposed control strategy effectively improved the DC-link voltage stability.