开断并联电抗器过电压机理分析及应对措施

Analysis and Countermeasures of Breaking Shunt Reactor Overvoltage Mechanism

随着电力系统的发展,以及线路电缆化率的提高,电力系统在负荷低谷期间对感性无功补偿的需求在不断增大,因此并联电抗器在电力系统中的使用越来越广泛。但是并联电抗器在开断过程中会产生截流效应,从而引发截流过电压以及重燃过电压,威胁电气设备的安全,影响系统安全稳定运行。从一次220 kV变压器跳闸案例分析出发,通过理论分析以及仿真模拟的手段,还原现场真空断路器开断35 kV并联电抗器产生过电压并最终引发故障跳闸的全过程,并提出应对该问题的措施。

With the development of the power system and the improvement of the line cable rate,the demand of power system for inductive reactive power compensation is increasing during load trough,so shunt reactor is used more and more widely in power system.However,the shunt reactor will generate current closure effect in the process of breaking,which will cause closure overvoltage and restrike overvoltage,threatening the safety of electrical equipment and affecting the safe and stable operation of the system.This paper starts from a 220 kV transformer trip case analysis,and through theoretical analysis and simulation,restores the whole process of the field vacuum circuit breaker breaking 35 kV shunt reactor to generate overvoltage and finally cause fault trip.Finally,the paper puts forward the measures to deal with this problem.