Research On Optimal Dispatching Of Virtual Power Plant Under Electricity Market Environment

With the depletion of traditional fossil energy,environmental problems such as smog and greenhouse effect are becoming more and more serious,and the contradiction between energy and environment is becoming more and more prominent.These problems seriously restrict the development and progress of human and economic society.In order to achieve sustainable development,people turn their attention to clean energy such as wind power and photovoltaic.On the one hand,wind energy and solar energy have become indispensable clean and renewable energy.On the other hand,the output of distributed generators such as wind power and photovoltaic is uncertain.When many distributed generators are disorderly connected,it brings many problems to the grid,which affects the economics,security and stability of the grid.In order to solve a series of problems caused by the operation and management of distributed generators,virtual power plants have emerged.The virtual power plant aggregates distributed generators such as wind power,photovoltaics,gas turbines,and energy storage to form a physically disconnected special power plant.Many small-capacity,disorderly connected distributed generators can participate in the management and operation of the virtual power plant.Their participation in electricity market transactions improves the economic and safety benefits of distributed generators.Consequently,this thesis studies the optimal dispatching problem of virtual power plants under the market environment.First of all,this thesis gives an overview of the concept of virtual power plants,analyzes the background and significance of the birth of virtual power plants,and analyzes the characteristics of distributed energy resources that make up virtual power plants and the processes and modes of participating in market transactions,and establishes the mathematical model to reflect the characteristics of distributed generators.For the uncertainty of distributed generators,this thesis uses Latin hypercube sampling to generate wind power output scenarios,and reduces them to obtain a certain number of scenarios.The expected output of wind power based on the scenario weighting is used as the actual value.Then,by taking the bid deviation of the virtual power plant within the day into account,and optimizing the plan of the day ahead and the day,and taking the maximum expected net profit of the virtual power plant as the objective function,an optimized dispatching mathematical model considering the complementary mechanism of bidding power deviation is established.This thesis considers the complementary mechanism of intraday deviation to reduce the penalty of bidding deviation.The results of the calculation examples show that the model proposed in this thesis can reduce the bid deviation penalty to a certain extent and improve the expected profit of the virtual power plant.Finally,in order to further reduce the uncertainty faced by the virtual power plant and stimulate the enthusiasm of demand response users' participation in the transactions,the market contract mechanism is considered,and the demand response incentive electricity price mechanism is formulated.Then the maximization of virtual power plant's net profit and the minimization of users' electricity purchase cost are used as the objection,and take the customers' electricity satisfaction into account,a multi-objective optimal dispatching model is established.This thesis uses the ideal point method to solve the model based on the introduction of agglomeration function.The simulation verification results show that the introduced market contract mechanism can avoid the penalty caused by uncertainty to a certain extent.The model taking the interests of users into account can stimulate the enthusiasm of users to participate in market transactions of the virtual power plant.