Regenerative braking system using brushless DC motor for electric bicycle

Most industrialized countries seek for an alternative solution in reducing the use of oil as a main source of energy in transportation. The use of electric vehicles has become an alternative solution wherein it produces zero emission. Electric bicycle would be ideal for fast travel due to numerous cars causing traffic and delaying travel time. Unfortunately, the use of electric bicycles has the burden of having short drive range. Thus, the study aims to implement regenerative braking system for a brushless DC motor intended for electric bicycle that recollects the kinetic energy that could go to waste due to braking and converts it to electric energy. The study develops a microcontroller-base control stsytem for regenerative braking and an algorithm for controlling the charging of the battery based from the power generated from the motor. For this study, the e-bike consists of the BLDC motor, motor controller, rechargeable battery, electronic design and the charging algorithm and telemetry for data. An XMC 4700 relax kit microcontroller was used and a voltage sensor was connected to the mocrocontroller with the use of software Dave application for programming. A ratiometric hall sensor A1302 was used to employ a proportional analog output for the brake to specify its level of depression, therefore, when the brake is triggered, it automatically disconnects the motor from the motor controller through the switching circuit and the motor runs as a free-wheel. A throttle, brake control, 3-phase conection, DC supply and hall sensors were the connections used in the motor controller. For the gathering of data, a bluetooth module was connected to the microcontroller to implement a wireless connectivity to the smartphone which serves as telemetry and states the voltage output from the motor and boost converter, brake and the actual PWM. In developing the algorithm for controlling the charging of the battery based from the power generated from the motor, it measures and sends all the inputs of the sensors as the microcontroller calculates the theoretical PWM from the attained value of vin and send a high output that turns on the switch of the MC brake. The results attained shows that the distance traveled by the e-bike with the use of regenerative braking and speed of 15kph was extended from an average distance of 6.23km to an average distance of 8.4km with 29.05% battery increase. As a result, this study determined the way fro extending the distance an electric bicycle could travel. It may then be adapted as a regenerative braking module that may be connected to any motor controller which implements the system of regenerative braking and extends the distance traveled without recharging the battery