New method for assessment of distributed generation impact on distribution system reliability: Islanded operation

The power generation, transmission & distribution system must be able to supply uninterrupted power reliably while maintaining the power quality throughout. The constraints like the generation capacity and system disturbances, affect the reliability and overall performance of system adversely. Thus, there is a strong need of enhancing power system capability to maintain power quality of the grid along non-conventional energy resources units. Distributed generation (DG) plants produce power on an electricity consumer´s own site or at the local distribution substation and can supply power directly to the customer or to the local distribution network. DG technologies are already having a large impact, particularly for high-reliability applications, as a source of emergency capacity or as a way of deferring the expansion of a local network. DG can be available in the case of a power system outage to assure a more reliable supply. This paper presents the role of the DG in improving the system reliability by proposing a new analytical method for calculation of load point indices in the case of DG presence in the system. The method is then applied to a study case.