ABSTRACT
Permanent magnets (PMs) eliminate the use of field exciting coils and slip rings for current conduction. Permanent magnet synchronous motors (PMSMs) are advantageous in incorporating the reluctance torque in the field-weakening range, so that they can be designed to have a wide constant power speed range (CPSR). Due to recent reduction in PM material cost and growing concern for greenhouse gases, PMSMs are widely used in home appliances such as refrigerators, air conditioners, vacuum cleaners, washers and so on. PMSMs are better in speed and position accuracies than brushless DC motors (BLDC). BLDC motors are normally used for low cost, low power (less than 5kW) applications such as blowers, material handling equipments, home appliances and so on. PMSMs are better in speed and position accuracies than BLDC motors. But the merits of BLDC motors lie in simplicity and costwise competitiveness.
