Optimal design of brushless dc motor using soft computing techniques

Abstract

The Brushless DC (BLDC) motors are increasingly being used for domestic, industrial, medical and aerospace application, as they are found to be more efficient than the existing DC motors due to their simplicity in control, high power density, reliability and maintenance free operation. The stator of the BLDC motor is like that conventional DC motor and the rotor has the permanent magnet. The BLDC motor control has two major parts. The inner part takes care of the commutation using feedback signals such as outputs from Hall Effect sensors, position encoders, B-EMF voltage sensors and phase currents depending on the commutation method. In the outer part, the motor speed and position are controlled. The type of supply required is 120 degree square wave of the alternating polarity or three phase sine wave and needs rotor position feedback. In the conventional design method the draw backs such as complex derivative, sensitivity to initial values and the large amount of enumeration memory requirement etc., have forced the researchers to relay on meta heuristic algorithms to solve optimization problems and randomness to initiate natural phenomena. newline