Quasi sinusoid commutation for BLDC motor — A simplified approach on 16 bit microcontroller platform

Brushless DC (BLDC) motors are increasingly demanded in various industrial and aerospace control applications. The conventional methods of implementing commutation for the BLDC motors are the Trapezoidal and Sinusoidal Commutation. Trapezoidal Commutation although has the inherent advantage of simpler implementation and lower switching losses, has the disadvantage of increased torque ripple. Sinusoidal Commutation on the other hand offers theoretically zero torque ripples, however has increased switching loss and implementation complexity. The paper proposes the Quasi sinusoid commutation scheme which combines the advantages of both Trapezoidal and Sinusoidal commutation. The proposed commutation offers the advantage of reduced switching loss, reduced torque ripple and does not require complex implementation. A comparative analysis based on simulation of the Trapezoidal, Sinusoidal and Quasi Sinusoid commutation is presented. Trapezoidal commutation and Quasi Sinusoid commutation schemes are implemented on a 24HJ128GP310 PIC microcontroller platform and the experimental results are presented.