Research On Contracts For Difference For Ancillary Services For Electrochemical Energy Storage Under The Dual Carbon Target

To achieve the dual carbon goal,China’s new power system must transform into a new power system with renewable energy as the main body.However,the randomness,volatility,and uncontrollability of renewable energy such as wind and photovoltaics will have a revolutionary impact on power system operation when developed on a large scale,leading to an increased risk of systemic accidents in the power system.It requires comprehensive support for power system auxiliary services.At the same time,the complexity of the power system is increasing,and energy storage technology is gradually being introduced into the power system.Energy storage technology can effectively smooth system power fluctuations and improve the stability of the grid.Achieving peak-valley transfer and responding quickly to load changes in the large power grid can promote the consumption of a higher proportion of renewable energy in the power system.Therefore,for the new power system with renewable energy as the main body,it is necessary to study the differential contract mechanism of energy storage participating in auxiliary services and the construction path of the differential contract market,solve the market mechanism problems of electrochemical energy storage applied to auxiliary services,and promote the consumption of renewable energy at a high proportion,and improve the stability of the grid.In order to design a suitable market mechanism for energy storage auxiliary service CFD,this paper constructs a two-tier dynamic optimisation game model for the construction of energy storage auxiliary service CFD mechanism,and a two-tier market transaction decision model is constructed with independent energy storage power plants as the main body.Firstly,the trading model of energy storage in the auxiliary services market and the CFD market is analysed,and a general framework for energy storage participation in market trading is proposed.On this basis,a two-tier decision model is established to comprehensively consider the participation of energy storage in the FM auxiliary service and CFD markets.The upper-tier model aims at maximising therevenue of energy storage power plants to obtain the optimal bidding strategy for energy storage;the lower-tier model aims at minimising the system cost to carry out the joint clearing of the auxiliary service market and the CFD market.The evolutionary algorithm is then used to solve the two-tier optimisation model,and an arithmetic analysis is conducted to verify the validity and rationality of the proposed two-tier model.In the last,the construction path of the energy storage auxiliary service differential contract market was discussed.The delivery methods of power contracts in the spot market are mainly physical delivery and differential contract delivery,but currently,the settlement of power market contracts in China is mainly physical settlement.In the process of building a sound spot market,promoting the participation of energy storage in the auxiliary service market,and establishing a differential contract settlement mechanism for the process of energy storage participating in the auxiliary service market,can improve the flexibility of the existing auxiliary service market trading mechanism and ensure the efficiency of resource allocation in the auxiliary service market.Therefore,based on the current development status of the power auxiliary service market,this article proposes a development path that promotes the participation of energy storage in the auxiliary service market and transitions from physical contracts to differential contracts,and provides specific design solutions for key market operation issues during the contract conversion process.