The Influence Of Micro-grid For Distribution Network Protection System And Countermeasures Research

Micro-grid as a new form of power systems can reduce the impact of fluctuations in the output of distributed power system incorporated within the micro-grid by each distributed power(DG)control and management.However,the emergence of micro-grid also bring a lot of adverse effects to the scheduling,operation and protection of power systems,to study it and take the appropriate methods to eliminate its adverse effects are a micro-grid technology from theory into practical use an important issue.In this paper,the impact of micro-grid distribution power system protection systems and new protection schemes do the following work:This paper introduces the definition of micro-grid structure,control methods and characteristics.The micro-grid structure of the United States Association for Electric Reliability Technology Solutions(CERTS)raised is studied.Micro grid control strategies the Grid and isolated operation is analyzed.Secondly,in the analysis of various types of distributed power control features based on the study of Direct DG fault characteristics and fault mode and control characteristics of PQ under V/f control mode of inverter type of distributed power.Through theoretical analysis and examples in PSCAD simulation environment,After MG access to the distribution network,the impact on the distribution network line protection MG is studied.Finally,the distribution power system layered protection scheme containing micro-grid is analyzed.The adaptive current instantaneous trip protection implementation methods are introduced.The mutation current algorithm is used to determine the fault.Two-phase current difference between the amounts of mutation algorithm is used for fault phase selection.The adaptive three-current protection utility formula is proposed.Containing micro-grid distribution power system improved adaptive instantaneous trip current protection algorithm and the scope of protection to be analyzed.In PSCAD simulation environment,the feasibility of includingmicro-grid distribution power system adaptive protection is verified.The results of this study,the development and improvement of distribution power system protection strategy have some theoretical significance and application value.