Electric vehicle power electronics cooling system pump control using fuzzy logic

Electric vehicles rely exclusively on electrical energy not only for propulsion, but also to power all of the vehicle subsystems. It then becomes critical that each subsystem is controlled in the most energy efficient manner possible. Some of the most energy consuming elements of a vehicle are the electric pumps that circulate coolant through an electric vehicle's coolant loop. Typically, these pumps are controlled through nothing more than simple temperature switch points, creating a sink for electrical energy. To improve the overall energy consumption, a fuzzy logic control (FLC) strategy for controlling an automotive coolant pump has been proposed. The power electronics coolant loop, which can be found in most hybrid/electric vehicles, have been examined as a temperature-based strategy which is formulated to control an industry standard pulse-width-modulated (PWM) fluid pump. Simulation of the proposed FLC has shown improvement of the overall efficiency of the coolant pump and has also reduced the overall energy consumption of the vehicle-thereby improving the electric propulsion range.