Introduction

In recent years, the motor control industry has been focusing on designing power efficient motor control drives for a wide variety of applications. The consumer demand for improved power quality standards is driving this trend. The power quality can be enhanced by implementing Power Factor Correction (PFC), and efficient control of a motor can be realized using Sensorless Field Oriented Control (FOC) techniques. The appliance industry often requires low-cost implementation of these algorithms. This can be achieved by integrating PFC and Sensorless FOC algorithms on a single microcontroller. Microchip's 32-bit microcontrollers have sufficient computational and peripheral resources to support PFC and Sensorless FOC on a single microcontroller.

This application note describes the process of integrating two complex applications: PFC and Sensor- less FOC. These applications are implemented on a Permanent Magnet Synchronous Motor (PMSM). In addition, this application note also describes the integration of the algorithms, lists the necessary hardware requirements, and provides the guidelines to optimize the development procedure.

The integrated solution is based on these application notes:

  • AN1106, Power Factor Correction in Power Conversion Applications Using the dsPIC DSC
  • AN2520, Sensorless Field Oriented Control (FOC) for a Permanent Magnet Synchronous Motor (PMSM) Using a PLL Estimator and Equation-based Flux Weakening (FW)
Note: Both of these documents are available for download from the Microchip web site at: www.microchip.com.

The application note AN1106, describes the Power Factor Correction (PFC) method. The application note AN2520, describes the Sensorless Field Oriented Control (FOC) method. The detailed digital design and implementation techniques are provided in these application notes. This application note is an addendum to the application notes listed above.

The low cost and high performance capabilities of the microcontroller (MCU) combined with a wide variety of power electronic peripherals, such as the Analog-to-Digital Converter (ADC), Pulse Width Modulator (PWM), and on-chip Op amps, and Comparator, enable the digital design and the implementation of such a complex application to be simpler and easier.