Digital control of two phase interleaved PFC and motor drive using MCU with CLA

Power Factor Correction (PFC) is used in power systems operating from single phase AC to correct for the non linearity of the rectifier. Use of PFC in motor drives is increasing because of increased regulation from the power utility side. However, integration of PFC and field oriented control of motor on a single controller remains challenging from a processor bandwidth point of view while keeping system costs down. The integration also brings challenges like better control of PFC output voltage under dynamic load and line condition while maintaining high input power factor. In this paper design of a motor control and PFC development hardware platform using a low cost microcontroller (MCU) is presented. Software and system integration challenges are illustrated and improvements to PFC algorithm using non linear control technique and anti windup integral controller are shown. It is further shown how the use of small footprint Control Law Accelerator (CLA) processor enables offloading control of PFC algorithm from the main core thus freeing up bandwidth to enable higher switching frequency operation of the power stage.