1. Hands-On Design of BLDC Motor Control with Microchip MCUs
Class 1: Motor Control Overview
2/8/2016
Warren Miller

2. This Week’s Agenda
2/8/16 Motor Control Overview 2/9/16 Development Environment 2/10/16 Motor Algorithm Details 2/11/16 Implementation Details 2/12/16 Example Designs

3. Course Description
Running code and seeing the resulting motor movements is the best method of learning new motor control design techniques.
This Design News course provides a hands-on tutorial to one of the most popular motor control algorithms for brushless DC (BLDC) motors, cementing key concepts and techniques.
We will use Microchip’s dsPIC33F microcontroller-based DM demonstration kit, available from Digi-Key (Here).
This course encourages you to follow along the instruction. Attendees can use the Microchip kit or the company’s free MPLAB IDE and C Compilers.
Running code and seeing the resulting motor movements is the best method of learning new motor control design techniques. This Design News course provides a hands-on tutorial to one of the most popular motor control algorithms for brushless DC (BLDC) motors, cementing key concepts and techniques. We will use Microchip’s dsPIC33F microcontroller-based DM demonstration kit, available from Digi-Key ( This course encourages you to follow along the instruction. Attendees can pre-purchase the Microchip kit or use the company’s free development software MPLAB integrated development environment ( and C compliers (

4. Today’s Topics Goals and Objectives
Where is Motor Control Used and Why is it Important to You
Key Elements for Motor Control
Motor structure, Algorithms and Concepts
Important Devices Used for Motor Control
MCUs and other devices
Development Environment
Devices, Boards, Software, Reference Designs, Wizards and Libraries
Resources

5. Goals and Objectives
Understand, at the overview level, key concepts we will use in the rest of the class
Why Motor Control?
Markets
Applications
Devices
MCUs and supporting devices
Development Environment
From Devices to Boards to Libraries

6. Why Motor Control?
Electric motors consume almost 50% of the worlds electricity
Electronics control can save almost 30% on energy
Motors are the way electronics interfaces to the ‘real world’- by moving stuff…
Applications are all around you- just count the number of electric motors in your home. Would you be surprised if it was close to 100? Just start in the kitchen…
Very big topic…

7. Motor Elements Stator- stationary part of the motor
Rotor- rotating part of the motor
Permanent Magnet- fixed magnet
Windings- wire wound in a circular arrangement to create an electromagnet
Commutator- mechanical method for changing current flow within a motor
Brush- flexible metal contact to conduct current to a rotor
Current/Voltage Control- method for providing adjustable current or voltage to a motor
Sensors- elements for determining position, temperature, velocity, etc.
Motor Elements

8. Force Generated By Magnetic Fields
Current in a coil creates a magnet. The strength and orientation of the magnet depend on current intensity and current direction
A magnetic moment tends to line up with the magnetic field. The magnetic dipole created by a coil, and thus the force that attracts the north or south poles, depends on the current.
To make a motor revolve the key parameter is the torque which is the force applied to the shaft. But how is the force generated? A current flowing in an inductance or coil creates an electromagnet. The characteristics of the magnet depend on the current intensity and direction. Two magnets will attract each other- the north and south poles attract each other. The force to attract two magnets depends on the strength of the magnetic field, which depends on the current flowing through the coil. Therefore the torque will depend on the current- the amount of current controls the torque of a motor.
The torque is proportional to the force generated by the current.

9. Types of Motors Stepper Motor Brushed DC Motor Brushless DC Motor
AC Induction Motor
AC Induction Motor

10. Stepper Motors

11. Brushed DC Motors

12. Brushless DC Motors

13. AC Induction Motors (Scalar)
AC Motors Architecture and Applications
AC Induction Scalar Drives
Control frequency and voltage
Open or closed speed loops
Slip regulation can improve efficiency
More complicated control logic
Self starting
Less sparking
Robust construction
Economical (no permanent magnet, no electrical connection to rotor)
Easy to maintain (no brush)
Applications
Heavy loads (> 1 horsepower = 750 watts)
Tools- lathe, drill, hand saw
Chemical processing
Pumps
HVAC

14. AC Induction Motors (FoC)
AC Motors Architecture and Applications
AC Induction Scalar Drives
Vector or Field Oriented Control
Variable frequency
Measure motor currents
Reference frame transform- to a rotating frame of reference
Much more computation required (32-bit MCU)
Increased efficiency, reduced noise, better dynamic response and improved torque regulation
Self starting
Less sparking
Robust construction
Economical (no permanent magnet, no electrical connection to rotor)
Easy to maintain (no brush)
Applications
Heavy loads (> 1 horsepower = 750 watts)
Tools- lathe, drill, hand saw
Chemical processing
Pumps
HVAC

15. Typical Devices Current Control Full and Half Bridge
Integrated Drivers
Sensors
Algorithm Control
MCUs
FPGAs

16. Development Environment
Software
Libraries
Wizards
Example code
Development Boards
Reference Designs
GUI-based Development Environment
Tutorials
Videos

17. Conclusion
Applications Motor Types Algorithms Devices and Environments

18. Motor Control Resources
Digi-Key Product Training Modules (49) [Filter for motor control]
Microchip’s dsPIC33F microcontroller-based DM demonstration kit, available from Digi-Key (Here).
Microchip’s free MPLAB IDE and C Compilers.
Digi-Key Motor Control Reference Designs
Microchip Motor Control Web Page
Microchip Simulink Web Page
Clarke, Park, Inverse forms, PID Control, etc.
Microchip Motor Control Library

19. Additional Resources
Motor Control App Notes (Microchip) Sensorless BLDC Control with BEMF Filtering Using a Majority Function Brushless DC Motor Control Made Easy Motor Control Overview (Renesas) Renesas Motor Control Overview Motor Control Overview (TI) TI Motor Control Overview

20. This Week’s Agenda
2/8/16 Motor Control Overview 2/9/16 Development Environment 2/10/16 Motor Algorithm Details 2/11/16 Implementation Details 2/12/16 Example Designs