Abstract
In order to solve the frequently occurred nonlinear working characteristics problem of the devices in integrated energy system (IES), where this nonlinear problem causes the offset of operation characteristics and design points of those devices, in this paper, the hierarchical multi-objective fuzzy collaborative optimization model of IES under off-design performance is proposed. Firstly, the high-order nonlinear models of devices under off-design performance, including fuel cell (FC), gas turbine (GT), absorption lithium bromide chiller (ABS), etc., are presented considering renewable energy and diversified storage devices, which can more accurately describe the actual working condition of devices. Secondly, according to the needs of different engineering application modes, the lower level collaborative optimization model of energy hub (EH) with economic, eco-friendly, primary energy saving, and renewable energy accommodation rate as optimization objectives is proposed, which can well adapt to and reflect real world energy system. Thirdly, based on the relationship between master and slave dispatch centers, the upper level modeling and optimal scheduling model of IES consisting of coupling power system, natural gas system, and heat system is proposed. Then, a multi-objective fuzzy collaborative optimization model for EH and IES is developed, where continuous differentiable Sigmoid function is taken as the membership function. Finally, simulation results show that the proposed models and optimal dispatch method can effectively solve the frequently occurred non-linear working characteristics problem of the devices in IES. The optimal results are suitable for planning, calculation, operation, dispatch of IES, which can reasonably reflect the operation characteristics of IES.
Highlights
The integrated energy system (IES) has become a vital strategic research direction in international energy field, due to its great significance in improving the comprehensive utilization efficiency of energy, the utilization efficiency of social infrastructure, and the energy supply security [1,2,3].In addition, the IES can promote the large-scale development of renewable energy and achieving energy conservation and emissions reduction in China [2,3]
The heat energy output by Recovery System (REC) is related to the heat recovery efficiency, which is affected by the part load rate, which can be expressed by: REC centralizes recovery of waste heat generated by gas turbine (GT) and fuel cell (FC) to achieve further energy hub (EH) energy
IES, which can be represented by equations models optimiz performance and models are presented in detailed lower level for EH, obtained which canoptimization, beand represente lower level optimization results to the upper level dispatching center, which prepare for upper level different engineering application modes, the lower level dispatching center uploads the data of the various data are from the lowe is optimized including single objective optimization and multi-objective w lower level optimization results to the upper level dispatching center, which prepare for upper level on the relationship between master and slave dispatching center, Firstly, the lower level model about models are proposed in upper level for IES, which can be represented by equations models and optimizatio optimization
Summary
The integrated energy system (IES) has become a vital strategic research direction in international energy field, due to its great significance in improving the comprehensive utilization efficiency of energy, the utilization efficiency of social infrastructure, and the energy supply security [1,2,3]. From the perspective of master and slave dispatch center, a hierarchical optimal scheduling model was presented for IES coupling power distribution system, natural gas transmission system and heat distribution system in [10] It focuses on each subsystem without considering the devices’ physical constraints such as load rate, start-up time, working hours and off-design performance in detail. The above “subsystem degree” research on IES is not deep enough on the whole or the system level, especially in the IES problem involving hierarchical multi-objective optimal operation and cooperative optimal scheduling of natural gas, power, and heat system. Upper level modeling and multiple optimal scheduling modes of IES with the coupling and interactions between heat system, power system, and natural gas system, are proposed, fully considering the key characteristic variables of the energy subsystems. An improved multi-objective fuzzy optimization method is presented, where continuous differentiable Sigmoid function is introduced as an improved membership function
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
