Electromagnetic interference characteristics during switching operation in power distribution network

Abstract The disturbance problem caused by the transient electromagnetic field during high-voltage switching operation is the most typical. Electromagnetic interference can be coupled to the secondary circuit in a conductive and radiating manner, then, affects the reliability of the secondary-side circuit. The key to the simulation calculation of the operating switch overvoltage is the judgment and simulation of its opening and closing conditions. The arc current zero-crossing judgment signal, the arc extinguishing and reignition judgment signals are fused, and a control signal is recursively obtained for switching operation. By analyzing the transient process during switch operation, a simplified model for isolating and closing the no-load bus, an overvoltage calculation model, and a fast transient model for overvoltage time-frequency signals are established. The characteristics of the transient electromagnetic field generated when the no-load bus and the circuit breaker of the disconnector are charged to the no-load transformer are simulated. The mechanism of fast transient pulse group generated by switching operation is obtained. The maximum overvoltage amplitude generated during the disconnector’s switching, and the no-load bus is obtained by simulation. Comparing with the measured data, the laws of electromagnetic interference characteristics during switching operation in power distribution network are verified.