补偿约束下动态电压恢复器不对称电压暂降补偿方法  

A Method to Compensate Asymmetrical Voltage Sag of Dynamic Voltage Restorer Under Constraint of Compensation Voltage Injection

作　　者：魏小淤[1] 杨洪耕[1] 

机构地区：[1]四川大学电气信息学院,四川省成都市610065

出　　处：《电网技术》2011年第2期78-83,共6页Power System Technology

摘　　要：针对补偿电压注入约束下的不对称电压暂降补偿,提出一种新的动态电压恢复器补偿策略。首先以A相为参考相,以各相电压端点为圆心作补偿极限圆,通过旋转B、C相极限圆得到有效补偿域;然后根据有效补偿域与参考电压圆的交角来确定完全补偿弧;最后沿此弧旋转负荷电压,在弧内求取最小能量注入解。该方法简单直观,适用于补偿三相负荷完全对称时由各种故障类型引起的电压暂降。由于此方法无需先抵偿负序和零序分量,通过在有效补偿域内对源电压进行直接计算,最大故障范围内实现负荷电压的对称补偿,且求解过程无循环搜索,响应速度快,满足实际工程应用的需求。To compensate asymmetrical voltage sag under the constraint of compensation voltage injection, a new dynamic compensation strategy for dynamic voltage restorer （DVR） is proposed. Firstly, taking phase A as the reference phase, compensation horocircles, whose centers are terminal points of three-phase voltage vectors, are plotted and by means of rotating the horocircles of phase B and C the active compensating area is obtained; then, according to the angle by which the active compensating area intersects to the circle of reference voltage, the complete compensation arc is determined; finally, rotating the load voltage along the arc, the least energy injection of DVR for each phase can be solved. The proposed method is simple and intuitional, so it is suitable to compensate the voltage sag caused by various faults under symmetrical three-phase load. In view of the fact that in the proposed method it is not necessary to pre-compensate the negative- and zero-sequence components, so the source voltage within by means of directly calculating active compensating area the symmetrical compensation of load voltage inside the maximum fault coverage can be implemented. The proposed method can fast respond to voltage sag and the cyclic search during the solution is not needed, thus this method can meet the need of practical engineering application.

关 键 词：动态电压恢复器 补偿电压约束 不对称电压暂降 有效补偿域 

分 类 号：TM76[电气工程—电力系统及自动化]