Speed Control of BLDC Motor Drive Using SVPWM Inverter

Abstract

BLDC motors find applications in Automotive (especially) electric vehicle (EV)), appliance and industries because it does not require mechanical commutator used in traditional motors, replacing it with an electronic commutator that commutator improves the reliability and durability of the motor. Three phase voltage source inverter feeds power to the BLDC motor. It is operated by energizing two of its three phase windings at a time. This makes efficient use of windings and develops higher motor torque. The energization of the stator windings are dependent on the position of the rotor. Hall sensors are used for determining the position of the rotor. Based on the position of the rotor the switching devices in the inverter are commutated for every degrees. The inverter gives desirable voltage and output frequency by controlling the switching times on or off using PWM techniques. There are various PWM techniques, among these sinusoidal PWM method and space vector PWM methods are mostly used today. SVPWM inverter gives better dc-bus voltage utilization, lower switching losses and better harmonic performance in comparison to the carrier based sine PWM inverter. PI controller is used for the speed control of the BLDC motor which leads to improve the behaviour of the motor. The SVPWM technique and speed control of the BLDC motor is simulated using the MATLAB Software package