The integrated reliability evaluation of distribution system considering the system voltages adjustment

Abstract

In modern society, with the development of electricity grids, besides the power supply continuity and stability, more attention are paid on the system voltage level and voltage parameters. Therefore, traditional reliability evaluation method with only some those reliability indexes cannot meet the situation and voltage attribute parameters and current power losses also need be calculated at the same time, which can prove a more comprehensive estimation for distribution system. Based on related researches from domestic and overseas, this paper is to find an efficient, feasible and flexible integrated reliability evaluation of distribution network. In this paper, a distribution reliability evaluation model is established in Matlab as a platform, using the Sequential Monte Carlo Simulation method to simulate elements' faults more accurately. This model includes the adjustment of nodes voltages in system, by the means of reactive power compensation and optimization using the Particle Swarm Optimization (OPS) algorithm. When the OPS is be used to solve optimization problem, power flow need to be calculated repeatedly, so the tool, Open DSS, is chosen to solve power flow calculation fast. In addition, the interface between Open DSS and Matlab is designed for Matlab invoking Open DSS which will make iteration faster. Finally, a series of improved reliability integrated evaluation indexes are defined. Combined reliability indexes, SAIFI, CAIDI, CAIFI, EENS, ASAI, with power quality indexes such as system voltage eligibility rate, voltage offset, power loss rate and other indicators to form a new reliability evaluation index system of distribution system. Taking the improved PG&E 69 node system as an example, use the model and algorithm proposed in this paper to evaluate reliability of this system.