动态电压恢复器电压补偿策略的研究

ANALYSIS OF VOLTAGE COMPENSATION STRATEGIES FOR DYNAMIC VOLTAGE RESTORER (DVR)

动态电压恢复器(DVR)在保证敏感负荷电压质量的同时与系统间存在能量交换,为了减少DVR的有功输出,提高DVR的补偿极限,文中针对不平衡电压跌落的特点,在考虑不同性质负荷对电压幅值和相移有一定容许范围的基础上,提出了新的最小能量补偿策略。通过对不对称三相电压相量的旋转和对称分量法来确定DVR的最优输出电压。仿真结果证明了该方法比其他电压控制方法更能有效地减少DVR的有功输出,加大了DVR的补偿范围。

The dynamic voltage restorer (DVR) is used to protect critical load from voltage disturbances and it exchanges energy with the connected distribution system. In order to reduce the active power output from DVR and enhance the DVR ' s compensation limit, this paper proposes a novel voltage control strategy producing the least energy output based on the analysis of the characteristics of the DVR compensation voltage when the system voltages are unbalanced and the definition of voltage tolerance of the different load. The optimum compensation voltage is presented by rotating three unbalanced voltage phase diagrams and using symmetrical component method. Simulation results show that the proposed method can reduce more discharge power between DVR and system than those using conventional methods, and effectively expands the compensation range of DVR.