Modeling And Optimal Operation Of Power And Heat Integrated Energy System

Environmental pollution,climate change,and energy security put forward higher requirements for energy supply systems.With the increasing requirement on comfort and energy reliability,traditional single energy system cannot meet the users' demand.To further improve energy efficiency,alleviate the environmental pollution crisis,and break through the traditional energy architecture and industry barriers,it is an efficiency way to study the integrated energy system.The integrated energy system can promote the coordinated operation efficiency of different energy systems.By utilizing the complementary characteristics of heat and electricity,it can reduce the pressures on a single energy system and realize peak staggering regulation.It is a good way to improve the reliability of each energy system comprehensively.On the other hand,more and more countries are aware of the vitality and competition after the power market is introduced into the power industry.Promoting the reform of power industry and applying more innovative achievements will significantly improve the benefits of enterprise.With the wide application of gas-fired combined heat and power units,the coupling of power and heat in production,transmission and sales is deepening.In the light of the positive impact of the electricity market on the power industry,the Nordic countries have begun to introduce competition into the heat production industry and have opened their heat markets.The capacity of cogeneration units accounts for a considerable proportion in northern China.It is a prospective and challenging task to establish an effect mechanism for the combined heart and power market.Based on the mentioned background,this dissertation studies the optimal operation of power and heat integrated energy systems and combined heat and power market.The main contents of this dissertation are as follows:1)An optimal operation method of combined heat and power is proposed considering transmission delay and the heat inertia of buildings.Considering the huge difference between power and thermal transmission mode,a heat network model considering transmission delay,node pressure and transmission loss is constructed.In order to achieve the zonal thermal balance and make full use of building thermal inertia,this dissertation built a thermal model of buildings considering heat consumption of building envelope,infiltration heat loss,and ventiliation heat loss.In the aspect of operation strategy of power and heat integrated energy system,a real-time error correction and optimization operation strategy is proposed to deal with uncertainties.The state equations are constructed by using autogressive model.The kalman filter method is applied to predict the load and renewable energies.To further improve the accuracy of prediction and decrease prediction errors,the residual error is used to modify GM(1,1)model,and then the prediction is corrected by numerical approximation.Based on error prediction,the output of equipment should be readjusted with the goal of minimum adjustment.On the premise of ensuring the safety of equipment and system operation,the output of equipment should be readjusted to improve the tracking ability to wind power output and load.2)Optimal dispatching method of heat and power integrated energy based on bilevel programming considering bilateral interests.In order to better consider the interests of users in energy consumption,this dissertation builds a bilateral programming model considering the bilateral interests of energy producers and energy users.Considering that gas turbines need stable and reliable gas supply,an upper optimization model is established,which takes stable operation of intgrated energy systems as constraints and maximizes the profits of energy producers.The lower level considers the thermal inertia of buildings and the thermal comfort of inhabitants.The indoor temperature demand is converted into the heat demand within a feasible interval.This bi-level model was transformed to a mathematic program with equilibrium constraint by KKT conditions,and further converted to a mixed integer linear programming problem.The convex combination method is used to linearize the non-linear constraints,and the original problem is transformed into a bi-level problem with only linear constraints.The original problem can be transformed into a mathematical program with equilibrium constraints by KKT conditions,and the complementary constraints are treated by the big M method.Finally,the bi-level problem is transformed into a single-level mixed integrated linear programming problem.3)A two-stage game research of multi-agents in combined heat and power market.To analyze the economic behavior of rational energy producers and consumers in the market environment,this dissertation constructs a framework of combined heat and power market including integrate energy suppliers,combined heat and power trading market,and consumers.The independent energy trading center is responsible for collecting and publishing information,so that there is no need for direct communication between consumers and between consumers and integrated energy suppliers.On the premise of fully considering consumers' thermal comfort and energy preferences,the response mechanism of consumers to energy prices is established.The existence and uniqueness of Nash equilibrium are proved in detail.It offers an approach to build an effective game model when using game theory for similar applications.Furthermore,a distributed algorithm is proposed that requires only limited message exchanges between players and IETC,which helps consumers to protect their anonymity.4)Research on multi-round quotation of combined heat and power market based on Generalized Nash Equilibrium Theory.This dissertation simulates the multi-round auction process in combined heat and power market by applying generalized Nash equilibrium theory.The equipment operation constraints of integrated energy suppliers are fully considered.Based on the mixed demand response,an analytical solution of the optimal energy purchasing strategy is obtained by constructing a consumer benefit maximization model.The proof of existence and uniqueness of generalized Nash equilibrium are presented in detail.In order to protect the privacy of game participants,a distributed algorithm based on augmented Lagrange multiplier is proposed to solve the optimization problem with privacy parameters in a distributed way.The multi-round bidding process under imperfect competitive market environment is simulated by updating Lagrange multipliers.After that,this dissertation analyzed the impact of the heat-electricity ratio on the game results.