| With the increasing proportion of new energy in the power system,the difficulty of power balance increases,and the uncertainty of power flow distribution increases sharply,which also brings challenges to the safety of the power grid itself and the operation control of peak and frequency regulation.Therefore,a certain proportion of flexible regulation of power supply is needed as support.However,the proportion of oil and gas generation in primary energy is very small,which lacks the large-scale flexible power regulation.Modern energy storage system has excellent performance and can be used to smooth power fluctuations and improve power quality,but the current power market mechanism needs to be improved.Based on this,this paper establishes a dynamic pricing mechanism for auxiliary services to promote the full participation of energy storage in auxiliary services,while coordinating the interests of multi-stakeholders of the grid-energy storage system,and optimizing the technical and economic performance of multi-stakeholders by allocating reasonable energy storage.In the coordination between the power grid and the solar power storage station,the capacity configuration of the energy storage in the new energy station is considered,and a two-layer optimal configuration model is established.The upper and lower layers aim at the lowest operating cost of the power grid and the solar power storage station respectively.In order to effectively coordinate the interest relationship between upper and lower levels,a dynamic pricing mechanism for energy storage auxiliary services is proposed,which uses price to guide the charge and discharge plan of energy storage,so that energy storage can fully participate in the auxiliary service market and balance the interests of upper and lower levels.By using CPLEX solver to solve the two-layer model iteratively,the optimal price of energy storage participation in the auxiliary service market is obtained.And the optimal configuration of the energy storage system.Finally,through the simulation analysis of the actual operation data of a provincial power grid,the dynamic auxiliary mechanism designed in this paper has better technical and economic benefits.The upper layer was optimal power flow optimization of distribution network,and the lower layer was the economic operation model of hybrid energy storage system.Considering the distribution network loss factors,a dynamic pricing mechanism based on branch network loss is proposed.On the one hand,four scenarios are selected respectively from the charge and discharge plan of energy storage,network loss performance,economic indicators for simulation and comparison.It is concluded that hybrid energy storage can reduce branch loss and voltage fluctuation on the basis of participating in auxiliary services.Through rational allocation of capacity,the benefits of grid-energy storage system can be maximized.On the other hand,through the simulation analysis of energy storage configuration and network loss and other indicators under different pricing mechanisms,it is verified that the optimal configuration model of hybrid energy storage has good performance under the dynamic electricity price mechanism considering network loss proposed in this paper. |
