动态电压恢复器的复合控制策略

动态电压恢复器（DVR）是解决电网电压跌落的一种经济有效的方案。文中在简要介绍DVR原理的基础上，首先分析了目前DVR所用的前馈控制策略和反馈控制策略，然后针对以半桥式逆变器为主结构的DVR，提出了一种由前馈控制、电压瞬时值反馈控制和滤波电容电流瞬时值反馈控制构成的复合控制策略，并推导了系统传递函数，进行了Bode图分析，最后，通过PSCAD/ EMTDC软件仿真和样机实验验证了复合控制策略的合理性和有效性。实验结果也表明复合控制策略能提高DVR系统的动态性能、跟随性和稳定性。

Compound Control Strategy of Dynamic Voltage Restorer

The dynamic voltage restorer (DVR) is effectively used in mitigating voltage sags. In this paper the principle and the current control strategies of DVR, including forward-feed control and feed-back control, are summarized. A compound contro strategy, consisting of forward-feed control, instantaneous voltage feed-back control and instantaneous capacitor current feedback control is proposed. The transfer function of system is deduced and its performance is also analyzed by Bode diagram. Finally, the results of simulation and prototype experiment verify the rationality and effectiveness of the compound control strategy, which greatly improves the tracking ability, dynamic performance and stability of DVR system.