糯扎渡直流频率限制控制器研究

直流孤岛系统送端容量小，抗扰动能力差，送端系统故障容易引起交直流功率不匹配，系统频率失稳，甚至导致孤岛系统崩溃。频率限制控制器能够根据交流系统频率，改变直流功率参考值，使交流系统向直流输送功率与直流功率参考值相匹配，保证系统有功平衡，维持交直流系统稳定运行。结合糯扎渡直流工程分析FLC结构和功能，对其主要参数进行整定，并通过仿真验证FLC的作用。

Study on the Frequency Limit Control of Nuozhadu DC Transmission Project

The sending end of a DC islanded system has poor anti - disturbance ablity because of its small system capacity. When AC and DC powers do not match in condition of fault, the frequency balance can not be maintained; even the DC islanded system will collapse. Frequency Limit Control （FLC） can adjust the DC power reference value according to the AC system frequency, ensure ac-tive power balance of the system, and make the system maintain stable. Combined with Nuozhadu DC transmission project, and analy- zing the structure and function of FLC, this paper makes settings of its main parameters and verifies its function by simulation.