模糊PID控制策略在动态电压恢复器中的应用研究

针对动态电压恢复器采用前馈控制方法和PID控制方法处理电压跌落问题的不足,提出了一种模糊PID控制策略。该控制策略实现原理:当电网电压检测系统检测到供电端电压发生跌落时,使动态电压恢复器投入到电网中运行;由标准信号产生模块产生与电网电压同步的标准正弦信号,用该信号与实际电网电压进行比较;然后通过模糊PID控制器调节得到需要实际补偿的电压给定信号,并利用控制环节生成逆变器所需要的PWM信号,通过驱动电路去控制逆变器功率开关的通断;逆变器输出电压经滤波后通过串联变压器注入电网,产生补偿电压用于抵消电网电压的波动。仿真结果验证了该控制策略的有效性。

Research of Application of Fuzzy PID Control Strategy in DVR

In view of deficiency that DVR uses feed forward control method and PID control method to process voltage sag problem,the paper proposed a fuzzy PID control strategy.Implementing principle of the control strategy is as follows: when detection system of power grid voltage detects voltage of power supply appears sag,DVR is put into power grid;a standard sine signal is generated by standard signal model which is synchronous with power grid voltage,and the signal is compared with actual power grid voltage;then a compensated voltage set signal is obtained after fuzzy PID controller regulates the signal,and a PWM signal needed by inverter is produced by control link,which controls on-off of power switch of inverter through driving circuit;the filtered output voltage of inverter is injected into power grid through series transformer to counteract fluctuation of power grid voltage.The simulation result proved effectiveness of the control strategy.