中文摘要：

在dq0坐标系下建立了双端VSC-HVDC系统的数学模型,并基于该坐标系制定了相应的控制策略。所采用的控制器由外环控制器和内环控制器构成,外环控制器由基于常规PI调节器的定功率控制器/定电压控制器构成,输出为内环控制器的参考值;内环电流控制器采用电流反馈和电压前馈的解耦控制策略,实现电流的快速跟踪控制。此外,针对VSC-HVDC启动时需要限流和限压的要求,在启动前投入限流电阻,确保系统能够平稳快速的响应,系统达到稳态后切除限流电阻。最后,在PSCAD/EMTDC的仿真结果表明,所设计的控制器具有很好的调节性能。

英文摘要：

A mathematical model of double-pointed VSC-HVDC system was established and its control strategy was draw up in dq0 coordinate system. The controller consisted of outer loop and inner loop. The outer loop, which combined power/voltage controller based on conventional PI regulator, its output was reference of inner controller.The inner current loop, which adopted current feed-back and voltage feed-forward, realizing the current＇s fast tracking. In consideration of the requirement of current and voltage＇s limitation in the process of start-up, resistors were inserted and made the system＇s response smooth and fast. They were cut off after the system＇s going to steady. Last, simulation tests realized by PSCAD/EMTDC were performed to verify the designed controllers have good response speed and recovery ability after fault.