Isolated Zeta PFC converter based voltage controlled PMBLDCM drive for air-conditioning application

An isolated Zeta converter is proposed as a power factor correction (PFC) converter with DC link voltage control for speed control of a permanent magnet brushless DC motor (PMBLDCM). The voltage source inverter (VSI) is used as an electronic commutator of PMBLDCM. The proposed converter performs the PFC action and DC link voltage control in single stage using only one controller. The current multiplier approach with average current control is used for operation of the isolated Zeta converter in continuous conduction mode (CCM). A rate limiter in the reference DC link voltage is designed for the control of current and torque in PMBLDCM. Detailed design, modeling and performance of the proposed PFC drive are presented for an air-conditioner driven by a PMBLDCM having 5.2Nm rated torque at rated speed of 1500 rpm. The designed PFC converter results in an improved power quality at AC mains in a wide range of speed control and input AC voltage.