Adaptive differential current protection for distribution network with inverter interface DG based on amplitude and phase characteristics of double-terminal current

As distributed generators (DGs) are installed on a large scale in distribution networks, the traditional current differential protection scheme may suffer from a lack of sensitivity, resulting in protection rejection. This paper proposes an adaptive current differential protection scheme in which the braking factor varies with the phase characteristics of the current on both sides of the protected line, and verifies the correctness of the proposed scheme through the PSCAD simulation platform. From the theoretical analysis and simulation verification, it can be seen that this scheme, compared with the traditional current differential protection, improves both the sensitivity of the protection in case of in-zone faults and the phase-shifting braking capability of the protection in case of out-of-zone faults.