Coordinated Control Strategy and Optimization of Composite Energy Storage System Considering Technical and Economic Characteristics

Abstract

-Control strategy and corresponding parameters have significant impacts on the overall technical and economic characteristics of composite energy storage systems (CESS). A better control strategy and optimized control parameters can be used to improve the economic and technical characteristics of CESS, and determine the maximum power and stored energy capacity of CESS. A novel coordinated control strategy is proposed considering the coordination of various energy storage systems in CESS. To describe the degree of coordination, a new index, i.e. state of charge coordinated response margin of supercapacitor energy storage system, is presented. Based on the proposed control strategy and index, an optimization model was formulated to minimize the total equivalent cost in a given period for two purposes. The one is to obtain optimal control parameters of an existing CESS, and the other is to obtain the integrated optimal results of control parameters, maximum power and stored energy capacity for CESS in a given period. Case studies indicate that the developed index, control strategy and optimization model can be extensively applied to optimize the economic and technical characteristics of CESS. In addition, impacts of control parameters are discussed in detail.

Economic Operation Optimization for 2nd Use Batteries in Battery Energy Storage Systems

“…Numerous optimal operation methods for BESSs have been reported in the literature. These methods can mainly be categorized as power and energy optimization control [4], [5] and economic operation control [6]- [11]. Power and energy optimization-based methods focus on charging and discharging control.…”

“…Economic operation control based methods focus on cost saving. Reference [6] proposes a novel coordinated control strategy to obtain optimal control parameters and minimize the total cost. Reference [7] proposes a model predictive control based optimization method considering battery degradation caused cost variation.…”