Analysis on Capability of Units in Shanghai Power Grid to Cope with Severe HVDC Accidents and Corresponding Countermeasures
CHEN Ming, CHENG Hao-zhong, LI Zhou-yan, WENG Wei-hua (School of Electronic, Information and Electrical Engineering, Shanghai Jiaotong University, Xuhui District, Shanghai 200030, China;Shanghai Municipal Electric Power Company, Pudong New District, Shanghai 200122, China)
At 13:56:59 on Nov. 20, 2005, double-pole block fault occurred in Long-Zheng HVDC transmission system, at that time about 3GW of power in East China power grid was affected. After lost HVDC power source, the frequency of East China power grid suddenly dropped to 49.518Hz, 231 seconds later the frequency was restored to normal value. Through the analysis on the response of units in Shanghai power grid during this period, the authors knew about the capability of units in Shanghai power grid to cope with frequency accidents and found the deficiencies of strategies for frequency accidents in primary frequency control and automatic generation control(AGC). To improve the capability of units in Shanghai power grid to cope with frequency accidents, corresponding strategies for these deficiencies were proposed.