DVR(动态电压恢复器 )的作用是抑制电压波动对用户侧敏感负荷的影响。文中运用相量法分析了负荷功率因数与 DVR补偿范围及其容量的关系 ,即当 DVR装置只输出无功功率时 ,其补偿范围受负荷的功率因数的限制 ,在负荷功率因数较大时 ,甚至无法满足要求。通过分析 ,给出了确定 DVR合理容量的定量描述。并根据装置的状态方程解决了 DVR不同控制目标的求解问题 ,对不同控制目标得出了不同的输出电压方案 The role of DVR (Dynamic Voltage Restorer) is to suppress the influence of voltage fluctuation on the user-side sensitive load. In this paper, the relationship between load power factor and DVR compensation range and its capacity is analyzed by using the phasor method. When the DVR device only outputs reactive power, the compensation range is limited by the load power factor. When the load power factor is large, Can not even meet the requirements. Through the analysis, a quantitative description to determine the reasonable capacity of DVR is given. According to the state equation of the device, the solving problems of different control objectives of the DVR are solved, and different output voltage schemes are obtained for different control targets