Optimal design of combined cooling, heating and power multi-energy system based on load tracking performance evaluation of adjustable equipment

Abstract

• Configuration method considering tracking ability is proposed for multi-energy system. • Tracking ability index is presented based on the closed-loop step response of device. • Relationship between tracking ability and economic cost is revealed by optimization. • Preference on tracking ability improves load following performance of the system. The load tracking performance of combined cooling, heating and power multi-energy system (CCHP-MES) is greatly dependent on the system design, including system structure optimization and equipment capacity configuration. Conventional CCHP-MES design approach only considers the economic, environmental and efficiency performance, while the dynamic load tracking performance is underestimated. For this reason, this paper proposes a novel tracking ability index in the capacity configuration optimization of the CCHP-MES by comparing the closed-loop dynamic differences of the involved adjustable equipment. The rise time and overshoot of the equipment output are selected as dynamic characteristics evaluation parameters, and their product can reflect the load following performance quality of the CCHP-IES. The tracking ability index is then embedded into the capacity configuration optimization objective of the CCHP-MES, and a novel MES configuration model is proposed with integrated consideration of the economic benefits and transient load tracking ability. Case studies using typical electrical, thermal, cooling loads and renewable power data verify the efficacy of the optimization model in the planning and design of the CCHP-MES. Considering the load tracking ability of the MES in the configuration will significantly improve the load following performance of the CCHP-MES at the expense of the increased capital investment.