A novel 4-limb earth fault compensation reactor for distribution network

This paper presents a novel earth fault compensation solution, which presents high positive sequence impedance and magnetically controllable zero sequence impedance. A 4-limb reactor is introduced to compensate earth fault currents in three-phase power distribution networks without the need of neutral point in substation transformer or separate earthing transformer. This results in considerably lower costs in implementing earth fault current compensation with much faster operation, making it possible to tune for 100% compensation during fault thus improving the probability of arc suppression. The presented reactor is analyzed analytically, and its performance is validated by simulations. The presented solution can significantly improve the reliability of the supply network.