Control method of multi-energy system based on layered control architecture

Abstract

The application of hierarchical control to complicated systems can considerably simplify the complexity of system control. The multi-energy system can be divided into superior control (such as load forecasting), intermediate control (dispatch control of each subsystem), and subordinate control (equipment operation control under each subsystem), and a realisation path for the theory of overall control strategy based on hierarchical control is formulated. In this work, the combined cooling, heating, and power system(CCHP) + ground-source heat pump(GSHP) + conventional cold and heat source + storage systems are used as examples based on the TRNSYS platform. The objective is to achieve the best comprehensive evaluation index by simulating the system’s key parameters of control. The operation control strategy method applicable to the typical multi-energy system is identified. When the system load rate exceeds 5%, the CCHP is switched on as a priority. Energy storage equipment release energy when the system load rate exceeds 13% with priority release at spike and peak sections. GSHP are turned on when the system load rate exceeds 37%. The gas boiler unit is turned on when the system load rate exceeds 72%. The system water supply temperature is simultaneously optimised in stages according to the outdoor air temperature. This strategy can make the annual comprehensive energy consumption per unit area of the case system the lowest. It can achieve better energy-saving operation effect in multi-energy system.