论文部分内容阅读
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。
Dynamic Voltage Restorer (DVR) is a cost-effective solution to the grid voltage sag. Based on the brief introduction of DVR principle, firstly, the current feedforward control strategy and feedback control strategy used in DVR are analyzed. Then, aiming at the DVR with the main structure of half-bridge inverter, a feedforward control, Voltage instantaneous value feedback control and filter capacitor current instantaneous value feedback control. The system transfer function is derived and the Bode plot analysis is carried out. Finally, the PSCAD / EMTDC software simulation and the prototype experiment are used to verify that the composite control strategy is reasonable Sexuality and effectiveness. The experimental results also show that the composite control strategy can improve the dynamic performance, followability and stability of DVR system.