500kV变电站SF6断路器投切并联电容/电抗器过电压现场测试OA

The new type of power system has imposed new requirements on the reactive power regulation capacity of the system.The switching frequency of traditional parallel reactors and capacitor bands has in-creased,and the failure rate has risen sharply.To investigate the causes of faults in parallel reactors and capacitor banks,a test system was developed to monitor 10 voltage signals simultaneously,with a sam-pling frequency of 100 MHz per channel.Using this test system,on-site tests were conducted to monitor SF6 circuit breaker operations-specifically,switching on and off parallel capacitors and reactors-at three different 500 kV substations,for a total of 80 tests in five intervals.The overvoltage suppression performance of RC snubbers was also evaluated.Based on the field test results,the voltage characteristics during opening and closing operations of parallel reactors and capacitor banks interrupted by SF6 circuit breakers were clarified;the statistical features of characteristic quantities such as the expected through and over-voltage-multiples were obtained,and the effectiveness of RC snubbers in suppressing both switching-on and switching-off overvoltages was quantified.In addition,a new set of key problems about suppressing the overvoltages of the parallel reactors and capacitor banks was also proposed.