Distribution network directional current protection applicable boundary evaluation method under distributed photovoltaic access

The invention discloses a power distribution network directional current protection applicable boundary evaluation method under distributed photovoltaic access. By checking whether the photovoltaic capacity combination of the particle j meets a constraint condition 1 of current protection sensitivity, a constraint condition 2 of no maloperation of a reverse fault of a direction criterion or a constraint condition 3 of no refusal of operation of a forward fault of the direction criterion, the individual optimum and the global optimum of the photovoltaic capacity combination are updated according to the situation; and iteration is utilized until the current optimal photovoltaic capacity combination Gbest is obtained. Compared with the prior art, the distributed photovoltaic absorption capability of the power distribution network is improved, so that the installation of the distributed photovoltaic in actual engineering is guided, and the safe operation of the power grid is guaranteed. 本发明公开了一种分布式光伏接入下配电网方向电流保护适