Design of electronic speed controller for BLDC motor based on single ended primary inductance converter (SEPIC)

Brushless DC (BLDC) motors have been applied extensively in household and industrial scale because of the advantages such as high efficiency and low mechanical losses because it does not use a brush such as DC motors. Application of the BLDC motors use rectified AC source to minimize battery usage. However, the use of BLDC motors and rectifying circuit causing poor power factor and facing harmonic problems. At rated power, BLDC motors have power factor about 0.58 while the current THD at 73%. These values are outside the permitted tolerance limits. This study aims to improve power factor and THD value of current caused by the operation of brushless DC motors using a SEPIC converter. Moreover, the purpose of this study is that the motor is able to operate at different levels of speed and various loads. The results of the simulation of the design have been made, the motors can respond to variations in the speed reference given to the good. The control circuit is also able to make the motor maintain pace with changes in the load every time. Power factor observed at source will rise until 0.99 at various speeds. In addition, the current THD has an average value of 2% at various speeds. Both of these parameters are within the tolerances allowed by the standard.