Voltage controlled PFC SEPIC converter fed PMBLDCM drive for an air-conditioner

This paper presents a single ended primary inductor converter (SEPIC) as a power factor correction (PFC) converter which is operated in voltage control mode for the speed control of a permanent magnet brushless DC motor (PMBLDCM) driven air-conditioner (Air-Con). The proposed converter combines the PFC and DC link voltage control in single stage and uses only one controller. The PFC controller uses current multiplier approach with average current control which is designed for continuous conduction mode (CCM) of operation. Moreover, a rate limiter is designed and introduced in the reference voltage at DC link for the control of current and torque in the PMBLDCM. Detailed design, modeling and performance evaluation of the proposed drive are presented for an Air-Con driven by a PMBLDCM of 0.816 kW, 1500 rpm rating. The designed PFC converter offers less than 5% total harmonic distortion (THD) in current at AC mains with near unity power factor in a wide speed range of the motor and input AC voltage.