Research On Optimal Configuration Andday-Ahead Optimization Scheduling Of AC/DC Hybrid Microgrid

Environmental problems and energy crisis are increasingly serious,countries in the world have turned to the development and utilization of new energy.Microgrid technology has been widely used because of its advantages such as high clean energy efficiency and flexible control.AC/DC hybrid microgrid has the advantages of both AC microgrid and DC microgrid,so it is a hot spot in the research of microgrid at present.The optimal allocation and economic dispatching are the key problems in the research of microgrid.Whether the optimal allocation and economic dispatching is reasonable directly determines the economical and reliable operation of the microgrid.In order to solve the problem of reasonable configuration and economic dispatch of AC/DC hybrid microgrid,this paper deeply studies the optimal configuration and day-ahead optimization scheduling of AC/DC hybrid microgrid.The main contents are as follows:Firstly,the typical topology of AC/DC hybrid microgrid is given,and its energy flow is analyzed.Mathematical models of photovoltaic cell,wind turbine and battery output power are given.Secondly,the distributed generation's site and size on the AC/DC hybrid microgrid is studied.The influence of distributed generation access on active power loss and node voltage of AC/DC hybrid microgrid is analyzed.The access node of distributed generation is selected according to the network loss sensitivity factor and voltage sensitivity factor of the node as the addressing index.On the basis of completing the location of distributed generation,capacity optimization is carried out.Considering the economy and stability of the system operation,the objective function with the minimum active power loss and the total voltage deviation of each node is established.Particle swarm optimization algorithm is used to optimize the capacity of the corresponding nodes to access the distributed generation,so that the AC/DC hybrid microgrid can be operated economically and stably.And then,the capacity optimization problem of AC/DC hybrid microgrid based on charge-discharge control strategy of TOU price is studied.An economic cost objective function is established to minimize the equivalent annual cost in the whole life cycle of AC/DC hybrid microgrid,taking into account the converter loss.It is proposed that environment-friendly index constraint and autonomous index constraint be included in the objective function in the form of penalty terms to participate in optimization.According to this model,considering the fluctuation of wind and light,the operation control strategy of battery charging and discharging based on TOU price is proposed.Particle swarm optimization algorithm is used to solve the problem,and the installed capacity of wind turbine,photovoltaic cell and battery under different AC/DC load ratio is obtained.The optimization results are compared and analyzed,and the capacity allocation principle of AC/DC hybrid microgrid under the operation control strategy is obtained.Finally,on the basis of optimal configuration,the day-ahead optimization scheduling of AC/DC hybrid microgrid is studied.Considering the economic index and reliability index,the day-ahead optimization scheduling model is established.The corresponding optimal scheduling strategy is worked out,and the particle swarm optimization algorithm is used to optimize the scheduling cycle,and the economic cost and clean energy electricity self-sufficient rate of a scheduling cycle are obtained.The energy scheduling within a scheduling day is analyzed,and the effectiveness of the model and method is verified.