The study of fuzzy control applied to variable refrigerant flow temperature control for electric vehicle air conditioning system.

The control strategies of electric motor driving air-conditioning (A/C) system for electric vehicle will affect temperature tuning response and energy consumption. In the refrigeration cycle of automobile A/C system, the outlet temperature of the evaporator can be controlled with variable refrigeration flow (VRF). The compressor speed and opening of expansion valve are two control variables for VRF. It is a non linear multiple inputs control system. In this manuscript, we use an embedded controller to control compressor speed to vary refrigeration flow of automobile A/C system with fuzzy control rules. Comparing temperature control response and energy consumption with ON/OFF control, conventional feedback control; known by the combined results, the fuzzy control is better than the others.