Market Equilibrium Analysis And Market Power Assessment Based On Electicity-Heat Integrated Market Clearing Mechanism

The integrated energy system(IES)with source-grid-load-storage coupling,coordinated planning and operation is gradually becoming an important form of energy system.With the reform of energy market,multi-energy coupling in the integrated energy system will gradually expand from the physical level to the market level.The form,subject,and characteristics of market competition have undergone major changes.Traditional operation methods such as determining power by heating load only focus on the economy of single energy source,which distorts the price signal of energy and limits the flexibility and economy of the IES operation.Physically coupled multi-energy production and energy-using equipment can hardly support the need for completely free and separate discrete transactions.Therefore,the market mechanism for the flexible discovery of multi-energy price signals under the complex physical coupling conditions in IES urgently needs to be designed and studied.In the face of changes in the form and characteristics of competition,the multi-energy coupling market power assessment based on the integrated energy system market is an important tool for evaluating new market mechanisms and exploring methods to restrain market power.In this paper,a clearing mechanism is proposed for the electricity-heat integrated energy market.The supply-side bidding considers the electrical-thermal coupling characteristics to satisfy the physical operation constraints,and the demand-side bidding uses the terminal utility to measure the value of multi-energy supply.Furthermore,a bi-level electricity-heat integrated market bidding model is established to analyze the supply side equilibrium.The upper level is the strategic offering of electricity-heat suppliers,whose goal is to maximize its own revenues.The lower level is the clearing model of the market operator(MO),whose goal is to maximize the social welfare of electricity and heat transaction.After translating the problem of the market clearing into the equivalent KKT condition,the supplier’s competitive equilibrium problem is transformed into an equilibrium problem with equilibrium constraint(EPEC).After simplification by the Big-M method and strong duality theorem,the diagonal algorithm is used to iteratively solve the market equilibrium.Furthermore,for the IES with multi-energy coupling and ambiguous roles of producers and sellers,cross-demand elasticity is used to describe the coupling between multi-energy market power,and a universal comprehensive evaluation index for multi-energy market power,multi-energy price controllable index,is proposed.The key to the multi-energy price controllable index is to solve the limit price strategy of each market entity.Aiming at the electricity-heat integrated energy market proposed in this paper,a limit price solution model and an improved particle swarm-Quadprog solution algorithm are established.Finally,a series of factors affecting market equilibrium are studied through the case analysis.The comparison of the social welfare of the integrated market and the traditional energy market reflects the superiority of the integrated market,and the multi-energy price controllable index is used to evaluate the market power of the integrated market to verify the effectiveness of the proposed method.