一种新型动态电压恢复器的仿真与实验

Simulation and experiment of new-type dynamic voltage restorer

提出一种新型可连续运行动态电压恢复器,主电路采用级联多电平结构,电网电压经过各隔离变压器后分别进行整流,给逆变单元的直流电容供电,通过电容耦合方式串入电网与负载之间;采用同相补偿法对电网电压进行幅值补偿,并引入改进的dq变换直接在线计算出补偿电压。利用PSIM软件进行仿真分析,并研制了实验样机。仿真及实验结果表明,该动态电压恢复器能够快速、有效补偿电网电压跌落以及电网电压谐波,保证了负载侧的用电质量。

A new-type uninterrupted dynamic voltage restorer is proposed,which adopts mulh-level topology in its main circuit and locates between grid and load via capacitor coupling. Grid voltage is isolated by transformer and rectified to supply DC capacitor. The in-phase compensation is applied for the magnitude compensation of grid voltage and the improved dq transformation for the calculation of compensation voltage. Simulation with software PSIM and experiment of a prototype demonstrate that,the proposed dynamic voltage restorer compensates the voltage drop and voltage harmonies of power grid quickly and effectively,ensuring the power quality at load side.