Research On Energy Dispatch Management Of Microgrid Based On Petri Net

With the global energy crisis and environmental degradation becoming more and more serious,clean renewable energy such as wind,solar and water has been widely used.In recent years,people have become more and more demanding on the safety,reliability and flexibility of the power supply,but it is difficult for traditional centralized power supply to meet these requirements.Because of its advantages in economy,environmental protection and flexibility,distributed power generation technology based on renewable energy has received extensive attention.Lots of distributed power supplies are connected to the large grid directly,which have a great impact on the safe and reliable operation of the large grid.In order to alleviate the impacts of distributed power supplies directly connected to the large grid,the microgrid technology emerged as the times require.There are many types of distributed micro-sources and a certain capacity of energy storage equipment in the microgrid.Due to the working characteristics of these distributed units are different,it is necessary to formulate appropriate energy dispatching strategy to properly manage the distributed micro-sources and energy storage equipment in the microgrid,and then realize the optimal operation of the microgrid.From the perspective of microgrid energy optimization scheduling,this paper mainly studies the optimal operation of distributed micro-sources and energy storage equipment in the microgrid.Firstly,this paper briefly summarizes the characteristics of different operating modes and different control modes of the microgrid,analyzes the working characteristics of wind turbines,photovoltaic arrays,diesel generators and storage batteries in the microgrid,and establishes the power output mathematical models of these distributed units in the microgrid.Secondly,due to the modal switching of these distributed units in the microgrid is complicated and Petri net can flexibly and conveniently describe systems with parallel,asynchronous and distributed features.This paper introduces the Petri net theory to describe the modal switching behavior of these distributed units in the microgrid,and the Petri net model is used to establish the energy dispatching strategy of each distributed micro-source,battery and the overall scheduling strategy of the microgrid system.For a microgrid system consisting of wind turbines,photovoltaic arrays,diesel generators and storage batteries,considers the microgrid grid-connected operation and island operation modes,under the premise of satisfying the constraints of system power balance constraint,distributed unit output power constraint,battery state of charge constraint,etc.,with the goal of economic operation and environmental protection operation of the microgrid,a multi-objective optimization scheduling model of the microgrid is established.Thirdly,in order to reduce the difficulty of solving the multi-objective optimal scheduling model of the microgrid,the multi-objective and multi-constraint problems in the optimal scheduling model are processed by linear weighting method and penalty function method.In order to solve the multi-objective optimal scheduling model of the microgrid,the particle swarm optimization algorithm is introduced,and the inertia weight and learning factor of the particle swarm optimization algorithm are improved,and the specific output of each distributed unit is allocated according to the solution result of the optimized scheduling model.Finally,taking an actual microgrid project as an example,two typical natural climates were selected to simulate and analyze the microgrid grid-connected operation and island operation.The simulation results show that the proposed microgrid energy dispatching method effectively reduces the overall operating cost of the system,and verify the validity and rationality of the microgrid energy dispatching method.