Research On The Joint Optimization Clearing For Eneregy And Primary Frequency Regulation Markets Incorporating Energy Storage

In the future low-carbon energy system,with a higher proportion of renewable energy connected to the grid,energy storage,as a new type of flexible resource,plays an increasingly important role in power system regulation by its fast response characteristics and flexible arrangement.With the development of the power spot market,energy storage as an independent market player to participate in the market operation strategy and market mechanism has been the focus of research in recent years.However,there are still many deficiencies in the market mechanism and policy environment for the efficient and reasonable application of energy storage.At present,the market-oriented operation mechanism has not been adopted for primary frequency regulation ancillary service in China.With the increasing demand for system frequency regulation,the construction of a primary frequency regulation ancillary service market is imperative.The battery energy storage system has the characteristic of precise control,bidirectional regulation,and rapid response,which has a significant advantage in participating in the primary frequency regulation ancillary service.Energy storage can replace conventional units to participate in primary frequency regulation service,to further optimize regulation capacity.Therefore,according to the technical characteristics of battery energy storage,this paper puts forward the characteristic model of energy storage participating in primary frequency regulation and a joint market clearing model including primary frequency regulation.Finally,the paper puts forward the coordination mechanism of its participation in the joint optimization clearing for the spot energy and the primary frequency regulation ancillary service markets.The main research contents of this paper are as follows:(1)The characteristics of different energy storage types are compared and analyzed.According to the characteristics of various energy storage technologies and application scenarios,battery energy storage is selected as the response resource to participate in the primary frequency regulation of the power grid.The frequency control process of the power system and the frequency regulation characteristics of the battery energy storage system are analyzed,and the frequency response demand process of battery energy storage is modeled.(2)The joint optimization model for energy and primary frequency regulation markets is established.The clearing mechanism of the primary frequency regulation market is described,and the calculation model of dynamic frequency constraints is established according to the reliability requirements of primary frequency regulation.Further,the joint optimization clearing model of the spot energy market and primary frequency regulation ancillary service markets constructed.Aiming at the minimum market joint clearing cost,the nonlinear constraint model is transformed into a two-stage model using the L-shape algorithm.Market entities provide ancillary services will produce lost opportunity cost.Finally,the calculation process of lost opportunity cost compensation is inferred.Case studies prove the effectiveness of the proposed joint optimization market clearing mechanism.(3)A joint optimization model of energy and primary frequency regulation ancillary service markets incorporating battery energy storage is established.Energy storage participates in the energy and primary frequency regulation market as an independent market player.The goal of energy storage is to pursue revenue maximization and form a secondary market with the market operator.Therefore,a two-level model between energy storage and the markets is established.The level of energy storage equipment aims at maximizing the energy storage owners’ profit,and the system level aims at minimizing the market-clearing cost.However,the model is non-convex nonlinear and cannot be calculated by conventional methods.The relaxation and primary dual reformulation of the original,and penalization of the associated duality gap are used to transform the non-convex model into a single-level mixed-integer linear programming problem that can be solved directly.The results reflect the influence of energy storage on system frequency and market-clearing price.The interactive decision-making relationship between energy storage operation and clearing price is balanced.