基于高耦合分裂电抗器的短路发电机保护断路器TRV仿真与分析

Simulation and Analysis of TRV for Short-Circuit Generator Protection Circuit-Breaker Based on High Coupling Split Reactor

基于高耦合分裂电抗器(HCSR)的保护断路器是大容量试验站发电机系统的重要保护装置,可以有效解决短路发电机系统短路故障的开断难题。本文研究了短路发电机保护断路器在均流开断和限流开断两种工作模式下,计算过零开断后暂态恢复电压(TRV)特性的等效电路和边界条件的问题,并以额定电压为14 kV、短路容量为6500 MVA的短路发电机出口端短路故障为例,计算两台并联的真空断路器在两种开断模式下的TRV参数。结果表明,在均流开断模式下,断路器BK1和BK2的预期TRV基本不受高耦合分裂电抗器的影响;在限流开断模式下,首先开断的断路器在第一和第二过零点的预期TRV均低于标准值,最后开断的断路器在第二个过零点的预期TRV上升率(RRRV)高于标准值,通过在高耦合分裂电抗器支路并联1000Ω电阻可以将RRRV降至合理的范围内。

The protective circuit breaker based on high coupling split reactor(HCSR)is an important protection device for generator system in large capacity test station,which can effectively solve the problem of short circuit fault.The calculation of the equivalent circuit and boundary conditions of the transient recovery voltage(TRV)parameters after zero crossing under two working modes of the short-circuit generator protection circuit breaker,i.e.,current sharing and current limiting breaking is studied.The short circuit fault at the outlet of the short-circuit generator with rated voltage of 14 kV and short circuit capacity of 6500 MVA is taken as an example.The TRV parameters of two vacuum circuit breakers in parallel under two working mode are calculated.The results show that the TRV of BK1 and BK2 is not affected by the high coupling split reactor under the mode of current sharing,while under the current limiting mode,the TRV of the first breaker at the first and second zero crossing is lower than the standard value,the TRV rise rate(RRRV)of the second breaker at the second zero crossing is higher than the standard value,and the RRRV can be reduced to a reasonable range through parallel connection of 1000Ωresistor in branch of split reactor.