Game Analysis Of Electricity Retail Market Considering Market Linkage And Consumers' Switching Behaviors

Introducing competition into electricity wholesale and retail markets is an irreversible trend around the world.Also,relevant documents have issued in China to promote the establishment of wholesale markets,encourage different types of retailers to participate in the retail competition and thereby enrich consumers' choices.For now,both the wholesale market and retail market of a certain region are akin to the oligopoly,and there is a strong linkage between the wholesale market competiton and retail market competition.Oligopoly equilibrium models are important tools for analyzing and forecasting the strategic bidding behaviors of market participants.Therefore,investigating market participants' strategic behaviors and corresponding impacts on market equilibrium based on oligopoly equilibrium models are helpful to the design and operation of the electricity market.In allusion to the shortcomings of the existing studies on retail market game,such as the insufficient consideration of consumers' switching behaviors and the linkage between wholesasle market and retail market,this dissertation has carried out a reseach of game modeling in the electricity retail market by considering retailers' contract trading,consumers' switching behaviors,retailers' risk preferences,and the linkage between wholesasle market and retail market.Specifically,the main work and innovations are as follows:Firstly,in order to analyze the impacts of retail contract trading between retailers and consumers on retail market equilibrium,the Bertrand game model for retailers' bidding in the retail market is proposed by considering the retail contract trading.In this model,the market share function(MSF)is introduced to describe the reputation differences among retailers and the loads to be served by a retailer against different retail prices.Meanwhile,the supply function is employed to model the relationship between the wholesale price and purchase demand of retailers,so as to reflect the close-loop interaction of the wholesale market and retail market.Then,the existence and uniqueness of the Nash equilibrium are proved.The impacts of retail contract volume on retailers' bidding strategies and market equilibrium outcomes are theoretically analyzed.Finally,the equilibrium model is solved by the nonlinear complementarity approach and Levenberg-Marquardt algorithm.The effectiveness of the theoretical analysis is verified by numerical examples.It is shown that a retailer with relatively higher reputation can occupy a relatively larger market share and gain more profit by offering a relatively higher retail price.Besides,the market power abuse of retailers can be mitigated by retail contract trading in the oligopolistic retail market,which can contribute to improve the retail market efficiency.Secondly,deregulation of electricity retail market enables competition among retailers and thereby enriches consumers' choices.In this environment,consumers are allowed to switch retailers according to their retail bidding prices.In order to quantitatively study the impact of consumers' switching behaviors on retailers' bidding strategies,a Bertrand-based game model for the retail market is proposed.Specifically,in the proposed model,the MSF is introduced to describe consumers' elasticity and switching behaviors,which is derived by assuming that a fictional representative consumer exists in the retail market who determines retail loads for all retailers so as to maximize the total payoff.Also,the close-loop interaction of the wholesale market and retail market is considered by using the supply function.Then,the existence and uniqueness of the Nash equilibrium are theoretically proved.The nonlinear complementarity approach and Levenberg-Marquardt algorithm are employed to find the Nash equilibrium outcomes Finally,the effectiveness of the theoretical model is verified by numerical examples.It is shown that consumers' switching behaviors can help mitigate market power abuse issues of retailers.Besides,due to the gradual mitigation of retailers' market power,the difference between retail prices and wholesale price will decrease.Thus,in the long term,the way to earn profits from the difference between retail price and wholesale price cannot fully support the effective operation of retailers.Therefore,in order to attract consumers and seek further development,retailers need to explore and offer innovative services in the electricity retail market.Thirdly,facing the uncertainty of wholesale price,retailers with different risk preferences will make tradeoffs between their market profits and risks through strategic bidding behaviors.In allusion to this problem,the mean-variance utility theory is utilized to model retailers' risk preferences and a Bertrand-based game model of the retail market is proposed.The MSF is used to describe the consumers' switching behaviors among retailers.Then,theoretical analysis is presented to investigate impacts of wholesale price uncertainty and risk preference on the bidding strategy.The Nash equilibrium of the proposed model is proved to exist and be unique,and further obtained via the nonlinear complementary approach and Levenberg-Marquardt algorithm.Finally,the effectiveness of the theoretical model is verified by numerical examples.It is shown that when risk-averse retailers participate in the retail market competition,the increase in the uncertainty of wholesale price will lead to the increase in the retail bidding price.Besides,the bidding price of a retailer will increase with the increasing risk-averse levels of itself and its rivals.In addition,consumers' switching behaviors can help to mitigate the market power of risk-averse retailers.The more risk-averse the retailers are,the more obvious the mitigative effect of consumers' switching behavior on their strategic behaviors will be.Finally,in order to study the interaction mechanism of strategic behaviors between the electricity wholesale market and retail market,a game model of the joint electricity wholesale market and retail market is proposed.In this model,the supply function bidding mode is applied to generators in the wholesale side,and the Bertrand bidding mode is employed to retailers in the retail side.Meanwhile,the contract trading between generators and retailers,as well as consumers' switching behaviors in the retail market are also considered.Then,by combining the first-order optimal conditions of all generators and retailers,the joint game problem is converted into a mixed nonlinear complementarity problem(NCP).The nonlinear complementarity approach is applied to reformulate the mixed NCP to a set of nonlinear equations,which are solved by Levenberg-Marquardt algorithm.Finally,numerical examples are presented to verify the effectiveness of the joint game model.It is shown that strategic bidding behaviors of generators and retailers will have significant impacts on equilibrium outcomes of both wholesale market and retail market.In addition,both the contract trading between generators and retailers,and consumers' switching behavior can help to improve social welfare.