Brushless DC motors are synchronous motors powered by a DC source via an inverter that produces an AC signal. There are three main types - inrunner, outrunner, and axial flux. Inrunners have the rotor inside the stator, outrunners have the stator inside the rotor, and axial flux uses facing plates. Brushless DC motors are complex but offer benefits over brushed DC motors like higher efficiency, speed, and lifetime. They are well-suited for applications like computer fans and industrial systems where those advantages outweigh their higher cost.

1. Brushless DC electric
motor
卡帝諾

2. General Definition
• BLDC motors are synchronous motors that are powered by a DC electric
source via an integrated inverter/switching power supply, which produces an
AC electric signal to drive the motor

4. Types of Construction

5. Inrunner (Conventional)
• Rotational core is within the motor’s can.
• Permanent Magnets are part of the rotor and there are 3
stator windings surround it.
• They can run up as high as 11000 RPM per volt.
• No torque

6. Outrunner
• the stator coils form the
center (core) of the motor,
while the permanent
magnets spin within an
overhanging rotor which
surrounds the core.
• Spins slower, but has
greater torque than
Inrunner
• Typically has more poles

7. The flat or axial flux type
• uses stator and rotor plates, mounted face to
face

8. Physical Representation
Brushed vs Brushless

9. Brushed
(SERIE WOUND FORKLIFT MOTOR)
DRIVE SHAFT
ELECTROMAGNET
COMMUTATOR

10. COIL
BRUSH

11. CHECK HOW STATOR IS
MAGNETIZED

12. • AFTER CHECKING THE STRATOR
FIELD, WE DETERMINE THAT
THERE ARE 2 POLES (NORTH AND
SOUTH)
WHEN THE ROTOR IS
INTRODUCED, THE FLUX
WILL BEND BECAUSE THE
ROTOR HAS HIGHER
MAGNETIC
PERMEABILITY THAN AIR.

13. WHEN THE COMUTATOR IS
INTRODUCED AN ELECTRIC
CURRENT FLOWS BUILDING A
SECOND MAGNETIC FIELD
AROUND THE ROTOR
CURRENT WILL FLOW
THROUGH ALL 3 COILS, YET
ONE COIL WILL ALWAYS BE
CONNECTED DIRECTLY TO
THE CURRENT HENCE
GIVING THE ROTATING
MOTION.

14. Brushless
(CD ROM MOTOR)

17. WE CAN OBSERVE THAT WE
HAVE 2 WINDINGS.
A PAIR OF WINDINGS ARE
CONNECTED TO PLUS POLE
VOLTAGE SOURCE Vcc, WHILE THE
OTHER PAIR OF WINDINGS ARE
CONNECTED TO GROUND VIA 2
ELECTRONIC SWITCHES

18. ONE SWITCH IS CLOSED
TO GENERATE A STATOR
FIELD. THE TWO FIELDS
TRY TO ALIGN AND THEY
START SPINNING.
THEN THE SWITCH CLOSES AND
THE OTHER OPENS GENERATING A
SECOND FIELD, HENCE IT KEEPS
THE SPINNING. A HALL EFFECT
SENSOR CAN BE INTEGRATED.

19. Function of MCU in BLDC motor

20. PID Regulation
• The ATmega32M1
microcontroller controls the speed
through a PID corrector.
• 3 Main coefficients:
 KP: Motor Response Time
 KI: Cancels the static error.
 KD: position regulator

21. Conclusion

22. Brushed
• PROS
• inexpensive and reliable
• simple control or no control at all
in fixed-speed designs.
• CONS
• require periodic maintenance
• brush friction increases and
viable torque decreases. (Not in
the case of toothbrush)
• inadequate heat dissipation
caused by the rotor limitations
• high rotor inertia
• low speed range
• electromagnetic interference

23. Brushless
• PROS
• more accurate in positioning apps
• require less and sometimes no
maintenance
• speed/torque
• no power loss across brushes
• high output power
• small size
• better heat dissipation
• higher speed ranges
• low-noise operation.
• CONS
• higher cost of construction
• Complex and expensive control
strategies
• require a controller that can cost
almost as much as if not more
than the BLDC motor it governs

24. • In general I would conclude the following:
 BLDC motors should not be used for every product. A perfect example are toy robots
targeting youngsters. It will be just a waste of money.
 BLDC motors should be used for computer hard drives, mechanical-based media
players, electronic-component cooling fans, cordless power tools, HVAC and
refrigeration, industrial and manufacturing systems, and direct-drive turntables.
 As an automobile enthusiast, I am eager to see the use of BLDC engines on HEV
cars. I believe that by improving the torque, heat dissipation, electromagnetic
interference, and high rotor inertia, a HEV will have the same power as a fuel
vehicle.

25. Bibliography
• Peng Zhang. Industrial Control Technology: A Handbook for Engineers and
Researchers.
• AVR194: Brushless DC Motor by ATMEL
• Brushless DC (BLDC) Motor Fundamentals by Padmaraja Yedamale,
Microchip Technology Inc.
• DIY Electric Car: 04 DC Motor Basics by Benjamin Nelson
• https://www.youtube.com/watch?v=C1-klL3B9LU