Modelling and control of current full compensation system‐based controllable voltage source

Abstract

Current active suppression technology of arc overvoltage in distribution network has small capacity of controllable voltage source and complex control and cannot flexibly adjust the zero-sequence voltage of neutral point. This study proposes a controllable voltage source system to fully compensate the arc current of ground fault for solving these problems. A controllable voltage source model based on passive supply voltage converter is established, utilising Dyn transformer to carry unbalanced load for a long time. The model output voltage is the same amplitude and frequency as that of single-phase ground fault phase, but opposite phase. The compensation switch is operated when a ground fault occurs. The output voltage amplitude of the controllable voltage source is controlled, the fault phase voltage is controlled to be 0 in the closed loop, the grounding fault arc current is eliminated and the arc grounding overvoltage is suppressed. The control strategy was verified by the PSCAD/EMTDC simulation model of single-phase grounding fault arc in 10 kV distribution network and the real single-phase fault experiment platform of 0.4 kV distribution network. Results proved the model and strategy's accuracy and effectiveness. It provides an engineering practical method for active suppression of arc grounding overvoltage in distribution network.