【摘要】 在交直流混联电网中,由于交流侧断路器跳闸或直流侧换流器闭锁造成的甩负荷经常会引起严重的工频过电压。目前,直流系统及交流电网均配置有过电压保护,但在实际应用中往往缺乏相互协调和配合,从而可能导致不正确动作。文中通过一起过电压保护误动事故的分析,指出交直流混联电网两侧过电压保护定值应满足选择性要求,并提出了整定配合原则。该原则目前已应用于西北地区直流输电工程及邻近交流电网中,提高了交直流混联电网过电压保护的运行可靠性。更多还原

【Abstract】 In an AC-DC hybrid grid,load rejection resulting from AC circuit breaker tripping or DC converter locking frequently leads to serious frequency overvoltage in the AC bus of a converter station.To protect the related equipment against damage,overvoltage protection is equipped both in DC and AC power systems.In practice,however,the current overvoltage protection of both systems often lacks coordination with each other,which may lead to incorrect operation.Based on an analysis of maloperation in overvoltage protection,it is pointed out that overvoltage protection on both the AC and DC system sides should meet the selectivity requirement on value setting,and the principle of setting cooperation is proposed.This method has successfully been applied to the high voltage direct current(HVDC) transmission project in Northwest China and its adjacent AC grid,greatly improving the performance of overvoltage protection in the AC-DC hybrid grid.更多还原