Air-Conditioning Optimal Scheduling Based on Finite Difference Thermal Model

Abstract

Optimal air-conditioning (AC) scheduling takes considerable potential in saving electricity cost and consuming local photovoltaic power generation for prosumers. In existing literatures, first-order or second-order equivalent thermal parametric (ETP) model is always used to approximate the thermal model of house, which remains significant discrepancy with the physical system. In this paper, we propose a finite difference thermal model (FDTM) to formulate the thermal dynamic of a house, and then develop an optimal look-ahead AC scheduling model based on the FDTM. Since the FDTM are linear difference equations, it can be easily integrated into the optimal scheduling model. Numerical tests are conducted to compare our model with a second-order ETP model, and verified by TRNSYS as the benchmark. The results show our model can achieve at least 10% improvement on temperature accuracy. The proposed AC scheduling method can reduce electricity cost without violating the allowable limits of indoor temperatures.