This paper describes a new mathematical model of permanent magnet brushless dc motor (PMBLDC) with sensorless commutated drive on MATLAB/Simulink based platform. The main challenges in sensorless BLDC commutation techniques compared with sensored drive lies in identification of first commutation point and minimization of torque ripple. In this work, an ideal back-EMF generation methodology has been designed and implemented in order to incline the system with the ideal one.
As a result, a significant reduction in torque ripple is achieved. The characteristics of this model give satisfactory outputs over a wide range of controlled speed variation from 700 to 14000 rpm. Moreover, the torque and speed characteristic provide a high torque even at low speed. The strength of the sensorless commutation technique used here is established by performance analysis of the simulated design.