静止无功发生器补偿电网电压不平衡的控制及其优化方法

Control and Optimization of Static var Generator for Grid Voltage Unbalance Mitigation

针对电网电压不平衡问题,提出了一种用静止无功发生器(SVG)抑制公共连接点(PCC)不平衡电压的控制方法。该方法既发挥了SVG补偿系统无功功率的优势,又在电网电压严重不平衡时扩展了SVG的补偿功能,充分地利用了补偿装置。文中详细讨论了SVG补偿电网电压不平衡的原理,将SVG控制作为受负载端负序电压控制的电流源,分析了其补偿性能与各个参数的相互关系。在补偿效果相同的前提下,对系统的控制参数进行了优化,使SVG的补偿容量最小。最后介绍了PCC处负序电压的实时检测方法。仿真和实验结果表明,该方法可以有效地补偿电源或负载引起的电压不平衡问题。

In this paper, a direct-current-controlled Static Var Generator （SVG） is proposed to solve the voltage unbalance issue at the Point of Common Coupling （PCC）. The SVG is operated as a current source controlled by the negative sequence voltage at the PCC. The relationship between all the parameters and the compensating characteristics is analyzed in detail. And an optimum control parameter is decided. The negative sequence voltage decomposition method is also introduced. Simulation and experiment results verify the satisfactory performance of the SVG in compensating voltage unbalance with the proposed control strategy.