A BLDC Motor Control with Variable Excitation Angle to Obtain Optimum Torque

Application of electric drives on electric vehicles requires high torque. One of the electric drive is BLDC motor for its high torque density. Operating such a motor require a proper control to excite the stator of the motor to produce maximum torque. The use of hall-effect sensor displaced 120 electrical degrees has some limitations. A control with capability to turn on and turn off the switches of the converter will determine the generated torque. In this paper, a control strategy that able to adjust the excitation angle for commutation is proposed. By using input capture facility of Digital Signal Controller, the angle can be adjusted in high precision. To support the analysis, experimental works were done by implementing dsPIC30F as a control core. The result showed that the proper excitation angle is able to maximize the generated torque.