高倍率放电锂电储能系统的输出电压斩波补偿控制方法与电流波动抑制策略

The lithium battery energy storage system (LBESS) can provide short-term high power and long-term high energy for electromagnetic launch system through high-rate discharge. However, the high-rate discharge LBESS has the problems of output voltage drop and current low-frequency fluctuation in the high-voltage and high-power launch process. This article introduces an energy storage system topology with N+1-level dynamic chopping converter, which can realize dynamic compensation of output voltage. To promote the rapidity of output voltage compensation, an improved active disturbance rejection control method by designing the variable gain (VG) control law with initial small gain is proposed to suppress the initial peak of total disturbance observation, thus improving the response speed of VG-ADRC controller. In order to decrease the dc current fluctuation, a nonlinear extended state observer with a muti-cascade notch filter is designed to attenuate the low-frequency components in total disturbance observation, the reference current is adjusted in real-time, thereby greatly suppressing the fluctuation amplitude of output current. Moreover, the frequency analysis shows that the proposed method does not introduce the negative phase into the loop transfer function and affect the stability of the original system. Finally, a 10 MW peak power pulsed discharge experimental platform was built to verify the effectiveness and practicability of the proposed strategies.