动态电压恢复器的最小能量补偿策略改进

Improvement of Minimum Power Compensation Strategy for Dynamic Voltage Restorer

通过对动态电压恢复器(DVR)进行电压跌落补偿策略的研究和最小能量补偿策略分析,发现改进DVR接入系统的拓扑结构,即在负荷端并联一个可调电抗器,电压跌落补偿时投入使用,负载功率因数越低,DVR补偿时消耗的能量越小,越容易实现纯无功补偿。提出暂时降低负荷功率因数来保证DVR在补偿时消耗能量最小的补偿策略。仿真结果表明,对结构改进是有效的,另外还可延长补偿时间。

A method for sag mitigation of a cascaded inverter DVR（Dynamic Voltage Restorer）with energy storage capability is studied.Through the analysis of phasor diagram and sag mitigation in different situations,the functional relation between DVR compensation capability and load power factor is obtained.It is found that energy consumption is more less with little load power factor and the pure reactive compensation is easier to be achieved.According to these conclusions,the topological structure of DVR connected to the system is improved in this way that a thyristor-switched inductor is added across the load which is be carried out when the DVR is compensating sags.Minimum power consumption is achieved with deliberate reduction of the power factor by the thyristor-switched inductor.Simulation results show the proposed method is effective which shall prolong compensating time.