A Faulted Terminal Open Circuit Voltage Controller for Arc Suppression in Distribution Network

Existing active arc suppression methods compensate fault current through controlling busbar voltage to zero. However, it may boost the fault point voltage in the case of considering load and feeder impedance, and fail to suppress arc. This study proposes a fault current suppression method by controlling the faulted terminal open-circuit voltage (FTOCV) and harmonic impedance of neutral-point. The effect of load and feeder impedance are taken into account. Depending on this, a faulted terminal open-circuit voltage controller (FTOCVC) is proposed for arc suppression, which consists of a reference voltage calculation module (RVCM) and a reference voltage tracking controller (RVTC). RVTC utilises a dual-loop voltage control method to adjust the neutral voltage for reducing FTOCV and providing a very low harmonic impedance for neutral-point. A reference voltage needed by RVTC can be figured out using RVCM accurately considering load impedance and fault distance. Thus, the proposed method can restrain the fault current to almost zero without influence by the load and feeder impedance. Comparison of several arc suppression methods was performed by simulation, and the results indicated the proposed method is more beneficial to extinguish fault arc.