The Optimal Electricity Allocation In Power Market Considering Microgrid

Power market reform has been the general direction of worldwide electricity powerindustry developing and reforming. While, distribution electricity market is an important partof power market reform. In the traditional electricity market，distribution company isconfronted with the problem of optimization of purchase electricity from generators andmarkets in order to reduce the cost of purchasing cost. At the same time, for the purpose ofincreasing revenue, distribution company is faced with the problem of power saleoptimization. With the continuous development of market reform and the openness of powermarket, microgrids which use renewable energy wil participate in the competition of powermarket. The effective trading between microgrid agents and a distribution company canpromote the development of distributed clean energy. Simultaneously, it’s consistent with thedirection of smart grid development.This paper first introduced the concept of the power market and microgrid、thedevelopment of power market at home and abroad from the power market. On the basis ofgrasp the microgrid’s construction situation、economic operating research status at home andabroad, analysis and summary of microgrid participate in the competition in power market.Distribution company purchase power in power market including several generators, in orderto reduce power supply cost, it is necessary not only to reduce network loss and avoid risk,but also to improve the efficienc of power production and transmission. Bases on analysis thefactors which effects the decision of distribution company purchase power from generators,this paper establishes an optimization model considering network loss and risk. Moreover, theeffectiveness of the model is proved by simulation.Secondly, by analyzing the operation characteristics of microgrid participate in powermarket, an optimization model which takes maximum revenue for microgrid agent as thetarget is established based on considering microgrid’s role duality. The model takes generatedenergy in microgrid、electric quantity sell to user、purchase and sale of electricity betweenmicrogrid and distribution company as optimization variables, considering both thecharacteristics of microgrid operation and the interruptible load in microgrid. Finally,optimized purchase and sell electric quantity of micro-grid agent participated in market indifferent roles was carried by an example. Simultaneously comparison and analysis wascarried under island model and grid-connected. Simulation reflected in order to pursuit benefitmaximization microgrid agent should regulate microgrid operator, balance the power sell toown users and distribution network. Result demonstrated the validity and feasibility ofmicrogrid’s optimal purchase and sell strategy after associate with main network. Under a competitive environment, the emergence of microgrid has a certain effect ondistribution company’s selling electricity quantity, it reduces the distribution company’selectricity sale to affect their interests. Developing effective strategy to optimally scheduleenergy trading between microgrid agents and the distribution company will bring benefits toall parties and promote further development of distributed clean energy. Electricity purchaseand sell electricity is joint optimized by analyzing the game relationship between microgridand distribution company. A bi-level optimization model which takes maximum revenue fordistribution company and microgrid agent as the target is established. According to the resultsof the model, distribution company can decide the purchase allocation from micro-grid agentsand generation companies. At the same time, micro-grid agents can determine electricity pricewhich selling to distribution company, the power purchase quantity with distribution companyas well as the electric quantity which selling to micro-grid users. A simulation example isused to demonstrate the validity and feasibility of this bi-level optimization model.The studying of microgrid participate in power market will be richer with the continuousdevelopment power market and the participate of new energy. More and more problems willappear in the process of practicing. How to actually and practically solve the transactionproblems between distribution and microgrid, that need to more research.