Behaviours of thermal management system with micro channels for cylindrical Lithium-ion cells under Fuzzy-PID control strategy

Abstract

Replacing conventional fuel vehicles with electric vehicles can effectively reduce pollution from fossil fuels. However, quick charging has been an urgently solved problem to promote the broad application of electric vehicles. A water-cooled battery thermal management system has been proposed, in which the cylindrical batteries were embedded into the cold plate with parallel microchannels in the height direction. It greatly enlarges the contact areas between the battery and the cold plate to strengthen the cooling capacity and improve the temperature uniformity in a high-rate charge. The charge experiments for the prototype of the battery module have been carried out at a 4C charge rate. the cooling behaviours of the system have been investigated including the heat dissipation, the response time, and the average state of charge under Switch, PID, and fuzzy PID control strategies. The fuzzy PID controller shows a desired control effect on the maximum module temperature and temperature difference at different ambient temperatures. Compared with the Switch and PID control strategies, the response time of the fuzzy PID controller is the shortest. At the same time, the average state of charge at the ambient temperature of 298.15 K, 308.15 K, and 323.15 K under fuzzy PID control can be improved to 94.3%, 94.2%, and 93.5 %, respectively. The cooling behaviours of the proposed battery thermal management system under fuzzy PID control are outstanding at a charge rate of 4C and the system is suitable for electric vehicles.