Research On The Coordinated Regulation Strategy For The Generalized Battery Energy Storage System

With the development of renewable energy power generation and global energy Internet,energy storage technology and demandside regulation technology have gradually become the key technologies to regulate the output of the intermittent energy,promote the clean energy consumption and improve the flexibility of power system,due to their strong controllability and high user participation.In order to reduce the practical application cost,energy storage technology has gradually developed from a single electric energy storage technology to an electro-thermal coupled energy storage technology.Demandside regulation technology has also gradually focused on thermal load regulation technology.The integrated clean energy consumption technology based on the hybrid energy storage and heating system has been under heated research.Based on the above technical background,this paper proposes a key coordinated regulation technology for the novel generalized battery energy storage system(GBESS).The research in this paper aims to realize the modeling analysis,balanced operation,complemental regulation,life depreciation optimization and decommissioning risk optimization of the multi-energy storage system.The concrete research content is as follows:(1)This paper proposes a novel concept of the GBESS.The regulating device that can be analyzed as a battery energy storage model is defined as a GBESS.The equivalent virtual battery storage models of the thermal storage and thermal load are studied to build the model for the GBESS.Based on the model for the GBESS,the equivalent electric models of the GBESS in different application scenarios are established for the battery-thermal storage system,battery-thermal extended storage system,battery-supercapacitor storage system,and supercapacitor-battery-thermal extended storage system.Based on the equivalent electric models,the characteristics of the State-of-Charge(SOC)and life depreciation for the GBESS are analyzed.Besides,a life depreciation evaluation method for the GBESS is proposed.(2)This paper systematically analyzes the differences of the SOCs and the capacity for the regulating units in the GBESS.The optimal rule of the balanced power allocation for the GBESS under the conditions of multi-unit participation is formulated and proved.An SOC balanced approximation algorithm is proposed to approximate the optimal state of the balanced power allocation.Based on the actual engineering data,testing results show that the proposed algorithm decreases the operation imbalance for the GBESS.Besides,when part of the energy storage units operate abnormally,the normal energy storage units will adjust their output power to satisfy the demand of the total dispatch power.(3)Considering the grade difference of the heterogeneous energy,the performance coefficient of the heat pump and the adjustable range of each unit,this paper formulates a fuzzy regulation rule and proposes a heterogeneous-energy complemental regulation scheme.The proposed scheme aims to improve the energy grade of the GBESS,reduce the energy dissipation of the GBESS and improve the comfort level of users.Based on the actual engineering data,testing results show that the proposed scheme increases the content of the high-grade electric energy in the GBESS,decreases the energy dissipation of the hot water storage tank,and decreases the fluctuation range of indoor temperature.(4)This paper systematically analyzes the depreciation characteristics of the GBESS.The GBESS is divided into three types: I,II and III.Based on the above analysis,the optimal charging and discharging rule for the life depreciation of GBESS is proposed.The minimum depreciation power tracking algorithm is designed to satisfy the optimal charging and discharging rule for different types of the GBESS.Based on the actual engineering data,testing results show that the minimum depreciation power tracking algorithm can reduce the life depreciation of type-I and type-II GBESS,compared to the conventional SOC balancing algorithm and the minimum depreciation unit selecting algorithm.For the type-III GBESS,the life depreciations using the conventional SOC balancing algorithm,the minimum depreciation unit selecting algorithm,and the minimum depreciation power tracking algorithm are the same.(5)This paper systematically analyzes the depreciation characteristics and dynamic response ability of supercapacitor,battery energy storage system and virtual battery of the heating system.A decommissioning risk assessment model is established to evaluate the healthy state of the GBESS.A maximum consistency tracking algorithm is proposed to minimize the decommissioning risk.Based on the actual engineering data,Testing results show that the proposed algorithm decreases the decommissioning risk index of the energy storage system and effectively reduced the utilization of the energy storage systems with high history depreciations.Hence,the operation stability of the energy storage systems is improved.Besides,the proposed algorithm make full use of the regulating units with high energy density and high power density.Hence,the total life depreciation of the energy storage system is decreased.Finally,the work of the whole paper is summarized,and the prospect of the further research is proposed.