【摘要】 针对动态电压恢复器(DVR)系统中由无功补偿电容器可能引起的谐振问题及抑制方法进行了研究。结果表明:当补偿电容器位于电网侧时,电容器与电网等效电感之间的谐振会引起电网电压畸变,此时DVR能稳定运行,但谐波补偿效果会减弱;当补偿电容器位于负载侧时,电容器与DVR滤波电感之间的谐振很容易使系统阻尼不足导致系统不稳定。将补偿电容器引入控制环,通过减小负载电流的前馈系数可以增大系统阻尼,保证系统稳定。仿真结果验证了上述分析的正确性。更多还原

【Abstract】 In this paper,the issue of resonance and suppression method possibly caused by reactive power compensation capacitor in dynamic voltage restorer(DVR)system is studied. It is shown by the result that when compensation capacitor is at the grid side,grid voltage distortion is caused by the resonance between capacitor and equivalent inductance of grid and,at this time,DVR can operate stably but the harmonic compensation result is decreased. While compensation capacitor is at the load side,the resonance between capacitor and the DVR filtering inductance will likely lead to the system unstable due to insufficient damp. By introducing compensation capacitors into the control loop,the system damp is increased by way of reducing the feed forward coefficient of load current to assure system stability. The correctness of above analysis is verified by the simulation result.更多还原