Synchronous DG planning for simultaneous improvement of technical, overcurrent and timely anti-islanding protection indices of the network to preserve protection coordination
The deployment of the distributed generation (DG), especially the synchronous distributed generation (SDG), as the energy infrastructure of smart grid in the distribution systems has drawn the attention of the distribution utilities to improve the system performance through DG planning. In this paper, a methodology has been proposed for the planning of SDG units in the distribution system in an attempt to optimize a multi-objective index including the active energy losses during the planning period, the active and reactive power losses at the peak demand, voltage deviations from a reference value, the network investment deferral, the overcurrent protection system speed, and the anti-islanding protection speed. The constraints include the feeders’ capacity, the maximum penetration limit due to anti-islanding protection requirements, the voltage limit, the preservation of the overcurrent protection system coordination, and the discrete size of SDG units. The proposed method has been applied to IEEE 14-bus test system with different cases including the different sets of weighting coefficients and the anti-islanding protections.