다중 분산전원으로 구성된 마이크로그리드의 유무효전력 제어원리 연구

Microgrids are new distribution level power networks that consist of various electronically-interfaced generators and sensitive loads. The important control object of Microgrids is to supply reliable and high-quality power even during the faults or loss of mains (islanding) cases. This paper presents power control methods to coordinate multiple distributed generators (DGs) against abnormal cases such as islanding and load power variations. Using speed-droop and voltage-droop characteristics, multiple distributed generators can share the load power based on locally measured signals without any communications between them. This paper adopts the droop controllers for multiple DG control and improved them by considering the generation speed of distribution level generators. Dynamic response of the proposed control scheme has been investigated under severe operation cases such as islanding and abrupt load changes through PSCAD/EMTDC simulations.