Reliability assessment and enhancement of distribution networks integrated with renewable distributed generators: A review

Majority of the power system faults occur at the distribution side and hence distribution network reliability studies have gained momentum in the recent decades. The increased penetration of renewable energy based Distributed Generation (DG) sources introduces lot of uncertainties in the planning and operation of the distribution network. This can have a detrimental effect on the reliability and hence proper measures are to be taken to maintain the reliability parameters within the specified limits. This paper gives a brief overview about the various impacts of renewable DG integration on reliability and the methods used for DG modelling. The various distribution network reliability evaluation techniques namely analytical, simulation and hybrid methods available in literature are also discussed and compared. Different reliability improvement techniques such as optimal switch/recloser placement, optimal DG allocation and sizing, reconfiguration of distribution networks etc. are also examined. Few niche areas of research in the field of distribution network reliability like handling uncertainties during reliability analysis, the relation between reliability and economics and the effect of protection devices on reliability are also explored. This paper gives a quick overview about the effects, evaluation methods and improvement techniques from a reliability perspective when renewable DGs are integrated into the distribution network.