The Research On Optimal Allocation Of Micro-Grid Based On Power Supply Reliability Analysis

With the coal, oil and other fossil energy supply problems becoming increasingly prominent, people pay more attention to the renewable energy and the clean energy,Distributed power generation mode has developed rapidly in the world. But when a lot of different properties of the distributed power supply connect to distribution network, due to its control is complex and difficult to manage, will cause great impact on the security and stability of the distribution network. On the other hand, with the rapid development of social economy, electric power consumption value increases ceaselessly, people are also getting higher requirements on the quality of electric energy and power supply reliability, Distribution system is the terminal part of power system, is directly connected with a power user. In our country, distribution network systems cause blackout about 80%,The reliability of power supply of distribution system is directly related to the industry, agricultural production and the quality of people's life level, is an important part of power system reliability analysis. This paper base on the power supply reliability of distribution network for the study of allocation optimization problem of micro-grid based.Micro-grid is an autonomous system of self-control, protection and management. It can operate both jointly and separately and improve to a great extent the reliability of power supply,and effectively improve the relationship between the distributed power generation and distribution network. Micro-grid optimal allocation is directly related to the safety and economical operation of distribution network. The methods of traditional optimal allocation mainly used multi-objective calculations to calculate. The present work provides a multi-stage decision planning method for Micro-grid, less time-consuming and easier to solve in comparison with the traditional method, aiming at the promotion of the reliability of power supply of the distribution network. At the first phase, according to the fault traversal influence matrix, a reliability evaluation is implemented on the system to find out the load point which can't meet the requirement for reliability. At the second phase, the position and number of micro-grid are confirmed by node adjacent matrix aiming on the basis of the load point searched at the first phase. At the third phrase, consider DG- BA combination complementary unit as the power source, with the voltage deviation, minimum network loss and minimum power loss as the objective functions and calculated by Harmony Search with global searching ability, the capacity and location of distributed generation in all micro-grids are defined. In order to improve the stability of the algorithm and avoid falling into localoptimum, It improve the initial solution of Harmony algorithm with merging the selection?crossover and mutation of genetic algorithm. In addition, the dynamic memory choice probability and disturbance probability of harmony search are used, changing with the increase of the number of iterations, and selects the solutions of harmony memory based on crowded degree distance. The effectiveness and rationality of this method is verified by simulation results of RBTS-BUS 6 system.