Fuzzy logic speed controller implementation to a supercapacitor based-regenerative brake system

During the braking process, the efficiency for the electric vehicles is improved through the recovery of energy by the regenerative brake system. The mechanical energy is lost and converted to heat when the conventional contact brake system is used. In this study, fuzzy-logic speed controller for a regenerative brake system using supercapacitors was designed, prototyped and tested. The prototype is mainly composed of a suspended wheel driven by a DC motor whose speed is varied and controlled through fuzzy logic algorithm. This study aimed at improving and maintaining the speed of the wheel to a set-point as compared with an open-loop system. This study also aimed to compare the performance of the proposed system that utilizes supercapacitor bank against a conventional system that uses a battery based on the recovered energy and the braking time. According to the experimental results, the proposed system improved its speed control through the fuzzy logic method as compared against an open-loop system. The data also showed that the proposed system using supercapacitor bank is significantly better in energy recovery and braking compared to the conventional system using a battery. On the average, the system using battery achieved 4.81% reduction in stopping time, while the system using supercapacitor achieved 30.29% in reducing the stopping time of the wheel during coasting. In a single braking, the average recovered energy using the battery is 0.01 J while 0.69 J of energy is recovered using the supercapacitor bank. Therefore, the system using supercapacitor recovered an average of 0.68 J more energy than using a battery in a single braking