Performance Study of Regenerative Braking of BLDC Motor targeting Electric Vehicle Applications

The main barrier to the widespread adoption of electric vehicles is the low mileage on one charge. A lot of kinetic energy gets wasted on the wheels of the vehicle in the form of heat during braking. Regenerative braking is the method of recovering the kinetic energy from the motor during braking. This paper presents the study of regenerative braking of BLDC motor targeting electric vehicle (EV) applications. The induced back electromotive force (EMF) during braking at the motor terminal is used as a source to recharge the battery. This method of regeneration improves the mileage of an EV and reduces braking time as well. However, the battery can be charged with this back EMF if its magnitude is higher than the battery voltage. A boosting action is performed to boost up the level of this back EMF without using any dedicated DC-DC boost converter or an ultra-capacitor. A three phase two level VSI in the closed loop with BLDC motor load is designed and implemented in MATLAB/Simulink environment. The generations of control signals for two level VSI with BLDC motor in closed loop operation are carried out to perform trapezoidal commutation. The energy recovery operation is verified by charging the battery during the braking of BLDC Motor. Simulation results are presented to illustrate the regenerative braking of the BLDC motor.