Stability constrained optimal distribution system reconfiguration considering uncertainties in correlated loads and distributed generations

Abstract

This paper proposes a small signal stability constrained distribution system reconfiguration (DSR) methodology under uncertainties associated with the load demand and the power output of the renewable energy based distributed generation. Further, the correlation among the uncertain load demand and among the uncertain DG power output has also been considered. This DSR problem is formulated for minimising real power loss, number of switching operations as well as maximizing the voltage stability margin. This formulation takes into consideration the system’s probabilistic operational constraints such as maximum limit on line current, minimum and maximum limits on bus voltage magnitude, radiality of distribution system and probabilistic small signal stability constraint. A KnEA-PE approach, consisting of a knee point driven method and 3 point estimation method, is then utilized to solve this DSR problem. The effectiveness and feasibility of presented formulation has been tested on IEEE 33-bus, 69 bus and 119-bus distribution systems. The obtained results are compared with those obtained by the multi-objective NSGA-II-based method.