Research On Optimal Operation Algorithm Of Microgrid In Island Model

Microgrid is considered to be one of the effective ways to make use of distributed power,especially renewable energy.Microgrid research aims to strengthen the scientific management of energy and improve the utilization ratio of renewable energy.Operation optimization is one of the important contents.From the bottom distributed power,due to the intermittent characteristics of renewable energy,how to maximize the distributed energy conversion efficiency and improve the steady-state accuracy of the bottom units,are the basis for optimal operation of microgrid.From the top of microgrid energy management and optimization,microgrid contains a wide variety of distributed power equipments influenced by the external environment,and the microgrid has obvious differences in different operation modes of mathematical model and the corresponding differences in energy management.On the basis of respecting the operation characteristics of the bottom units(bottom units benefit)basis,using effective optimization method and realize the optimal microgrid system are important guarantees for the reliability of power supply and environmental protection to improve the utilization rate of renewable energy,to meet the requirements of economy.Therefore,in this paper,based on the research of the microgrid system structure,two aspects of the underlying distributed power units and the top level energy management optimization algorithm are studied.The main work of this paper is as follows:(1)Research on microgrid architecture.The microgrid system with wind solar storage and multi load is established;the load is divided into three categories: non interruptible load,translational load and interruptible load;the microgrid energy management system is designed;the distributed micro sources are modeled,introducing the photovoltaic cell engineering using mathematical modeling scheme,analysis of the output characteristics of the photovoltaic cell,as the basis of microgrid optimization and maximum power point tracking strategy.(2)Research on the optimization strategy of the micro grid units.Focus on the maximum power point tracking strategy of photovoltaic power generation system,through the analysis of the existing MPPT control strategy when the light intensity changes dramatically leading to the problem of dead zone.In this paper,an improved variable step size optimization algorithm is proposed,and the step transition function and the algorithm flow are designed.At the same time,the algorithm is used to adjust the initial step length on the left and right sides of the MPP.Using the proposed algorithm,both the dynamic response speed and steady state precision of the system are considered in two aspects.When the external conditions change,the step transformation function will be divided into fixed step size and variable step size region.Avoiding the problem of dead zone of the traditional algorithm,the effectiveness of the algorithm is proved by simulation and experiment.(3)Research on optimization algorithm of microgrid energy management system.In this paper,non-cooperative perfect information dynamic game theory is introduced,making load participate in active energy management of microgrid to realize interaction between supply and load sides.User's economic interests and satisfaction are taken into consideration to guiding load plan.Then this plan is used as load demand to optimize the microgrid output.Simulation results show that the proposed method can not only balance the user's satisfaction and interests in load side effectively,but also make the best use of renewable energy in supply side.Via the rational action of microgrid individuals,the optimization of microgrid energy is realized.