Research on current DC offset of energizing a no-load transmission line with high voltage shunt reactor

When a transmission line with high voltage shunt reactor is energized, the current DC offset will occur, which may cause a failure if the circuit breaker opens immediately after the closing operation. In this paper, a 500kV transmission line with high voltage shunt reactor is slected as the research object, and the electromagnetic transient simulation is carried out through the electromagnetic transient simulation software EMTPE to study the DC offset caused by closing of the circuit breaker of the long line with high voltage shunt reactor, including the DC offset caused by the single-phase closing of different phases. The simulation results show that for the transmission line with high voltage shunt reactor, it is reasonable that the temporary switching current doesn’t cross zero when closing the no-load line. This paper mainly analyzes the principle of this phenomenon and gives relevant suggestions.