云广HVDC孤网运行瞬时频率抑制的附加控制

在孤网运行方式下,为抑制交流故障后交流系统的瞬时频率,利用换流器稳态方程导出换流母线电压与直流电流的动态关系,结合故障特点,应用HVDC的快速和高可控特性,设计了一种反映整流站换流母线电压具有惯性环节的高压直流输电(HVDC)瞬时频率附加控制器,实现对整流器给定电流的修正和直流功率调制,提高了故障后送端交流系统瞬时频率稳定性。云广±800kV特高压直流输电系统的电磁仿真结果表明,在送端交流系统故障下,该附加控制器能够有效抑制交流系统的瞬时频率。

Instantaneous Frequency Suppression of Additional Control for HVDC Transmission System from Yunnan to Guangdong Under Islanded Operation

In the isolated AC system running mode,for suppressing instantaneous frequency when AC system faults,using the steady-state equations of converter,the dynamic relationship between direct current and busbar voltage was deduced.with application of the rapid and HVDC high controllable characteristics,a kind of reflection rectifier busbar voltage HVDC instantaneous frequency additional controller with inertial link was designed,which gives the current correction of rectifiers,to realize power modulation,and to keep frequency stability of sending end AC system after sending terminal AC system fault.On Yun Guang ± 800 kV DC transmission system,electro-magnetic simulation results show that the additional control can suppress the AC system of sending instantaneous frequency with AC system fault occurring in sending end.