与超高压输电线路加装串补装置有关的系统问题及其解决方案

文章结合我国南方电网河池固定串补及平果可控串补工程,对超高压输电线路装设串联电容补偿装置后的系统状况进行了比较深入的研究,指出一些系统问题,如过电压水平升高、潜供电流增大和可能发生的次同步谐振均源于串联电容补偿装置的固有特性,通过研究认为当串补所在输电线路发生内部故障时,采取强制触发旁路间隙等保护措施,是避免出现系统恢复电压水平超标和潜供电流增大等问题的有效途径.此外,还建议在串补站内装设抑制或监视次同步谐振的二次装置以抑制和避免系统发生次同步谐振.

PROBLEMS CAUSED BY ADDING SERIES COMPENSATION DEVICES TO EHV TRANSMISSION SYSTEM AND THEIR SOLUTION

Taking the Fixed Series Compensation (FSC) and the Thyristor Controlled Series Compensation (TCSC) respectively installed at Hechi and Pingguo substations in South China Power Grid for example, the situation of power grid after the series compensation devices are installed is deeply researched and it is pointed out that a series of systematic problems, such as the arising of overvoltage level, enlargement of coupling current and the possibility of taking place the subsynchronous resonance (SSR), are caused by the inherent characteristics of series compensation devices. After the research it is held that when internal fault takes place in the transmission line where the series compensation device is located, the corresponding protective measures, e.g., the forced triggering the by-pass gap, etc., is the effective approach to avoid the appearance of excessing level of transient recovery voltage (TRV)and oversize coupling current. In addition, in order to suppress or avoid SSR it is suggested to install the devices such as the secondary equipments to suppress or monitor the subsynchronous resonance.