Research On Monitoring System And Islanding Detection Of Microgrid

Micro-grid is a distributed generation system that can integrate a variety of micro source and load together to achieve efficient use of energy,it can work on the run-grid and off-grid state autonomously. Currently, micro-grid technology has become a hot topic in the field of distributed generation. Micro-grid system consists of a bottom layer equipment and monitoring system, Monitoring system is the brain of micro-grid, is responsible for coordinating the entire system control. Islanding detection is an essential function of micro-grid because it requires the ability to run in island conditions.The relevant research about the design of micro-grid monitoring system and islanding detection algorithm has been done, Related algorithms of micro-grid monitoring systems were studied, and micro-grid coordinated control has been improved, a new black start strategy of micro-grid and islanding detection algorithm control based on droop control, and its related improvements has been maken.The structure of the monitoring system of micro-grid which uses hierarchical control is designed, according to different functions,the micro-grid monitoring system is divided into central control system and human-computer interaction system. On this basis, the microgrid cooperative control and black-start algorithm have been researched, experiments and simulations have been done.This paper analyzes the principle of droop controland mechanism of island effect occurrence detailedly,on this basis, an islanding detection method based on droop control is proposed, add frequency positive feedback to the coefficient by judging continuous times of frequency deviation to give corresponding disturbance to improve the selection of active power disturbance,which can accelerate the speed of islanding detection and reduce the impact on power quality when grid is in the normal state.At last simulation results show the effectiveness of islanding detection algorithm.