电网电压骤降时PWM整流器的控制

Control of PWM Rectifier Under Grid Voltage Dips

研究了电网连接的三相两电平电压源转换器(VSC)在电网电压发生扭曲时的控制结构。电网电压发生扭曲是由电压平衡或电压非平衡跌落、高次谐波等原因引起的。为了解决这个问题,提出了一种转换器控制结构。控制系统是基于双矢量电流控制器(DVCC)的电压定向控制器(VOC)的改进。在电压扭曲情况下通过采用锁相环(PLL),实现电网同步。仿真结果和试验证明了系统的性能。

I he control structure lor grla connectea mree-pnase two-level voltage source converter （VSC） under distorted grid voltage conditions was researched. Grid voltage is distorted by balanced and unbalanced voltage dips and higher harmonics. To address the problem,the control structure of converter was presented. The control system is a modification of voltage oriented control （VOC） based on dual vector current controllers （DVCC）. Grid synchronization under distorted voltage is achieved by employing phase locked loop （PLL）. Simulation and experimental results illustrate properties of proposed system.