An Improved Flux Observer Based Position Sensorless Single Stage BLDC Motor Drive With Regenerative Braking For Solar Powered LEV

In this paper, solar-PV array and battery assisted light electric vehicle (LEV) drive train with (brushless direct current) BLDC motor is designed considering Indian drive cycles. An improved flux observer is implemented for position sensorless commutation of BLDC motor, suitable for wide speed range with optimal torque and current control. The estimated rotor position is further improved using a PLL structure, which provides smooth commutation, thus reducing commutation torque ripples to a great extent. Regenerative braking is incorporated into the system by modifying the gate pulses to the VSI without additional external circuit arrangements. The overall drive structure, including solar and regenerative braking, helps to improve EV drive efficiency. The MPPT control is achieved in single stage, avoids an additional DC-DC converter, thus further reducing cost of the system. The system is designed in MATLAB/Simulink environment and analysed in detail for suitability in practical condition.