说明：  UPFC中间直流电容上电压控制的重要性 论文在传统 PID控制的基础上 设计模糊自适应 PID控制策略 控制方案能有效地提高直流电容上电压的稳定性 改善功率波形 取得了类似扩大电容容量后的效果
(UPFC DC capacitor voltage control among the importance of paper in the traditional PID control based on fuzzy adaptive PID control strategy designed control scheme can effectively improve the stability of the DC voltage on the capacitor to improve the power waveform to obtain a similar effect after the expansion of capacitance)