Green Mode Control Strategy of a PMSM with Front-end SEPIC PFC Converter

Abstract

A motor drive with a PFC front-end converter provides advantages of improved power quality and over-all system efficiency. A buck-boost PFC converter provides adjustable output dc-link voltage for switching loss reduction of the connected PWM inverter drive. This paper proposes a green mode control strategy for the variable output voltage power factor correction (VOPFC) ac-dc converter and connected dc-ac inverter for PMSM drives in applications to centrifugal loads with wide speed control ranges. The VOPFC converter is a bridgeless single ended primary inductor converter (SEPIC), which both high side and low side switches are driven with the same PWM signal and is designed in operation in discontinuous conduction mode (DCM). Centrifugal load characteristics have been used for the loss analysis of the VOPFC inverter motor drive. An optimum dc-link voltage can be found for a specified operation speed with optimum over-all efficiency. Analysis-oriented simulation and experiment has been carried out for the green mode control strategy of VOPFC inverter PMSM drive.