| Recently,the rise of global temperatures and the increase of extreme weather events due to climate change have been posing enormous threats to the environment and human society,while the global energy shortage has become increasingly prominent.In order to face climate change-related problems,many countries worldwide have proposed emission reduction plans,actively promoted clean energy,sought alternative energy sources,improved energy efficiency,and strengthened energy management.Within this context,traditional centralized and independently-operated electric power systems are gradually transitioning to distributed and jointly-operated multi-energy systems,with the coupled electricity and heating system being a typical form of multi-energy system and attracting attention from market operators.With the initial success of the electricity market liberalization,the lifting of regulations in the heating market will be a necessary step towards the liberalization of the future multi-energy markets.Considering that long-distance heat transportation is not economically feasible,the coupling operation of regional electricity and heating markets is more practical.The regional electricity and heating market is of great significance for ensuring energy supply of local residents,optimizing the energy consumption structure,and achieving efficient energy utilization.However,due to the diversification of participating entities and the complexity of the operating environment in the regional electricity and heating market,issues such as conflicts of interest and information asymmetry among participants have gradually emerged,leading to low market efficiency and increased operating risks.To this end,this thesis investigates in details the regional electricity and heating market.Within the context of the current operation status and future development trends of the electricity and heating markets,we thoroughly analyze the trading and operation of regional electricity and heating markets,with special focus on trading strategy,operation mechanism and distributed optimization method.A theoretical framework for regional electricity and heating markets trading and operation is developed by leveraging on the concepts of multi-agent trading strategies,efficient trading mechanisms and distributed optimisation methods with privacy protection.The derived framework provides theoretical and technical support for trading and operation of low-carbon environment electricity and heat markets of the future.The main contents of this thesis are summarized as follows:1)The analysis of multi-agent behavior in the intra-regional electricity and heating markets with social welfare optimum.Firstly,a multi-stage trading model is developed considering that the intra-regional energy market has multiple players and small trading volume.The regional trading center,as a non-profit operator,guides the market behavior of participating agents by issuing differentiated price signals to achieve the optimal social welfare of the regional market.Then,based on non-cooperative game theory,the behavioral changes of demand and supply-side market agents are characterized,and the existence and uniqueness of multi-agent game equilibrium are proved using the variational inequality.Finally,a differentiated price signal control is proposed,and a distributed bidding algorithm with nested alternating direction multiplier method is employed to reduce unnecessary information exchange,thereby achieving the convergence of individual and global interests.The case studies validate the effectiveness of the proposed algorithm and demonstrate that the model achieves weak budget balance while improving global social welfare.2)The analysis of multi-agent behavior in the inter-regional electricity and heating markets with individual interests optimal.Unlike small-scale intra-regional markets,inter-regional markets are characterised by a limited number of participants and large transaction sizes.A decentralised inter-regional electricity and heating multilateral contract trading framework is constructed based on these characteristics.A master-slave game framework is used to model the process of inter-regional multilateral trading,in which suppliers maximize their individual profits through their offers,and the demand side develops a strategy for participating in the multilateral market based on price information,and participates in the integrated demand response.Then,the existence of an equilibrium solution for the multilateral contract market is proved and an iterative distributed algorithm is proposed to reach it.At last,case studies demonstrate the effectiveness of the proposed algorithm and the results show that regarding the demand side,active participation in the multilateral contract market helps to diversify the risk of purchasing energy in the spot market and increase the profitability,whereas regarding the supply side,as the number of participants increases,suppliers who actively reduce their marginal costs are able to benefit more.The above two sections focus on the multi-agent analysis of regional electricity and heating markets,which use game models to characterize the relationship among multiple players in the market transaction and to develop individual strategies.And equilibrium analysis is performed to ensure the efficient operation of regional markets.3)Hierarchical operational method for single-regional electricity and heating market under complementary constraints.Based on the trading strategies of intra-and inter-regional electricity and heating market discussed in the previous sections,the operation of single-region and multi-region electricity and heating markets is further studied by taking into account physical constraints.By considering the operational characteristics of the “heat-based dispatch” nature of combined heat and power units in the coupled electricity and heating systems,a sequential clearing model for electricity and heating markets with multiple layers of complementary constraints is developed in accordance with their operation rules.To solve such a complex multi-layer mathematical problem,the tri-level complementary constraint problem is firstly transformed into a bi-level complementary constraint problem through the primal-dual method,and then the bilinear terms are handled by the binary expansion method.A reformulation-decomposition algorithm is then proposed to solve the reduced bi-level problem.Finally,case studies demonstrate that the proposed algorithm has good solution performance for multi-layer complementary constraint problems and show that the sequential clearing approach can bring more benefits to the operation of the coupled electricity and heating markets.4)Hierarchical operational method for multi-regional electricity and heating market based on virtual federated prosumers(VFPs).In the actual low-carbon environment,where energy systems are increasingly coupled between regions,a “from bottom to up” model for the operation of a multi-regional electricity and heating market based on VFP of producers and consumers is established.VFPs as different market players,participate in the inter-regional energy sharing market and intra-regional budget allocation,respectively,and coordinate the operation of the two-layer market.A flow-based distributed clearing approach is proposed for inter-regional energy sharing markets clearing,and a distributed feedback-based control algorithm is proposed for intra-regional budget allocation.Based on this,a progressive iterative algorithm is used to coordinate the clearing of the two-layer market.In the end,case studies show that the proposed multi-layer operational architecture helps to stimulate the participation of distributed resources in the market and increase the absorption of renewable energy.In addition,it can reduce carbon emissions associated with energy production at the market level and provide a reference for the operation of future lowcarbon regional multi-energy markets. |
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