Study on Switching Transient and Influencing Factors of 330kV Cable Transmission System

The transient impact caused by switching operation in power system threatens the life of equipment and may endanger the security of system. In particular, the inrush current and reignition overvoltage in the process of switching on and off have become the focus of academic and industrial circles. In order to fully understand the transient behavior and its influencing factors of cable transmission system during switching on and off, in this paper, the effects of line length, closing resistance and shunt compensation on closing inrush current and opening reignition overvoltage are studied systematically. It is found that with the increase of line length and the decrease of reactive power compensation capacity, the inrush current and reignition overvoltage are on the rise. In addition, the inrush current can be effectively reduced by introducing the closing resistance as the restraining measure, but the selection of the resistance value is not the bigger the better. The research in this paper shows that the value of 200-400 Ω closing resistance is more recommended in practical application. The research results of this paper have important engineering value and guiding significance for the design and optimal operation of power system.