High efficiency and low-cost switched reluctance motor for air-conditioner blower

Abstract

To date, induction motors have mainly been used for heating, ventilation and air conditioning (HVAC) applications, however there is significant research being done world-wide on the use of switched reluctance motor (SRM) in home appliances. So far the electronics cost of SRM drives makes it uneconomical to expand their application to home appliances but it is the objective of this paper to present SRM for use as air-conditioner blowers with both cost merit, and good performance expectations compared to conventional induction motors. This paper proposes a new power device drive scheme using SRM switching characteristics which is both simple and inexpensive. It will also adopt the dwell time control method for minimum switching of the power device. By use of this scheme, SRM drives can be fabricated with rugged power devices incurring very small switching losses. Furthermore, the control method shows a very robust and reliable drive even in cases of torque disturbance or overload condition without current sensors. This SRM design also adopts a bobbin type winding and printed circuit board (PCB) connection between bobbins, which includes a single rotor position sensor assembly. This production method reduces winding time by half compared to conventional winding process. Acoustic noise is a potentially severe problem with SRM depending upon the home appliance application. This problem is remedied by the mechanical structure and control algorithm. Additionally, the proposed SRM achieves a 15% higher efficiency with lower cost, compared to the conventional use of induction! motor And lastly, the SRM can be fabricated to be 20% more compact, and run with a wider speed range than conventional motors.