Configuration Optimization Of Capacity Of Distributed Generation And Energy Storage In Micro-Grid Considering Grid Constraints

The micro-grid has the characteristics of flexible operation mode, independent control, and can effectively regulate the distributed generation, therefore distributed generation in the form of micro-grid has important practical significance in efficient utilization of renewable energy. When distributed generation and energy storage access superior grid in the same micro-grid node, we can use the good charge and discharge characteristics of storage system, to absorb and storage power from the grid in the load valley, and release it to micro-grid in the load peak, thus can compensate the intermittent output of distributed generation, smooth power fluctuations, and improve the power supply reliability and renewable energy absorption effectively. At the same time, it can also reduce the load peak and valley difference in micro-grid and in response to the scheduling constraints of superior grid, so as to effectively improve the power equipment utilization rate, delay the upgrading and reconstruction of power transmission and distribution equipment, and reduce the power loss of the grid.In grid-connection condition, considering the constraints of the superior power grid, respectively from the micro-grid power supply reliability and user benefits aspects, this paper studies the configuration objectives, the evaluation criteria and constraints of the distributed generation and energy storage, proposes and solves two optimal complementary capacity configuration models of capacity of distributed generation and energy storage in micro-grids. In addition, different capacity configuration strategies corresponding to different types of micro-grids are given by example analysis.First of all, analyze load characteristics of kinds of common urban micro-grids and new load characteristic (including electric vehicles slow charging pile, fast charging pile, street lamp charging pile integration equipment, etc.) in detail, study the analysis method of load models, and achieve a comprehensive classification of micro-grids by the fuzzy clustering algorithm, thus obtain five types of typical micro-grids for distributed generation and energy storage capacity configuration and simplify the research of capacity configuration strategies for a large number of micro-grids.Secondly, using the JB test method, prove that the distributed generation output does not have normal distribution, and cannot be estimated simply by using the normal probability distribution model, estimate the probability distribution of the output on the hour by studying the frequency of the distributed generation output on the hour, and study the daily output curve of distributed generation in different confidence levels for capacity configuration model by using the confidence interval method.Then, from the aspect of micro-grid power supply reliability, taking peak load shaving of micro-grid tie line power as configuration objective, establish the economic evaluation criteria of the distributed generation and energy storage, design and solve the optimal complementary capacity configuration models of the micro grid system, and get the different capacity configuration strategies corresponding to different types of micro-grids by example analysis.Finally, from the aspect of user benefits, analysis the economic benefits of distributed generation and energy storage, set up the different configuration schemes, objective functions and constraint conditions of different types of micro-grids, design and solve the optimal complementary capacity configuration models of the micro grid system, and get the different capacity configuration strategies corresponding to different types of micro-grids by example analysis.