The presentation contains the details about construction, rotor configuration,characteristics and commutation of PMBLDC motor

1. CONTENTS
 Definition
 Diagram
 Hall effect
 Hall effect sensors
 Transverse rotor
 Commutation Sequence
 Torque Speed Characteristics
 Comparison
 Six step commutation
 References
Permanent magnet
Brushless DC (PmBlDC)
motors
Kongunadu College of Engineering & Technology PMBLDC Motor

2. Permanent Magnet Brushless DC
(PMBLDC) Motors
• Permanent Magnet Brushless DC Motor is the
special type of DC motor
– Magnetic fields generated by the stator and rotor
rotate at the same frequency
– No slip
• Rotor has no windings. Which has permanent
magnets
Kongunadu College of Engineering & Technology PMBLDC Motor

3. PMBLDC Motor
Kongunadu College of Engineering & Technology PMBLDC Motor

4. BLDC Motor Rotors
Kongunadu College of Engineering & Technology PMBLDC Motor

5. Hall-Effect
• If a current-carrying conductor is kept in a
magnetic field, the magnetic field exerts a
force on the moving charge carriers, tending to
push them to one side of the conductor,
producing a measurable voltage difference
between the two sides of the conductor.
Kongunadu College of Engineering & Technology PMBLDC Motor

6. Hall-Effect Sensors
• Need 3 sensors to determine the position of the
rotor
• When a rotor pole passes a Hall-Effect sensor,
get a high or low signal, indicating that a
North or South pole
Kongunadu College of Engineering & Technology PMBLDC Motor

7. Transverse Sectional View of Rotor
Kongunadu College of Engineering & Technology PMBLDC Motor

8. Commutation Sequence
Each sequence has
– one winding energized positive (current into the
winding)
– one winding energized negative (current out of the
winding)
– one winding non-energized
Kongunadu College of Engineering & Technology PMBLDC Motor

9. Torque-Speed Characteristics
Kongunadu College of Engineering & Technology PMBLDC Motor

10. Kongunadu College of Engineering & Technology PMBLDC Motor
Comparison

11. Six-Step Commutation (4-pole)
• Hall-Effect Sensors
spaced 60 electrical
degrees apart
• 6 steps to complete one
electrical cycle
• Phase current switching
updated every 60
electrical degrees
Kongunadu College of Engineering & Technology PMBLDC Motor

12. Kongunadu College of Engineering & Technology PMBLDC Motor

13. REFERENCES
S.No Books / Web Sources
1. K.Venkataratnam, ‘Special Electrical Machines’, Universities Press (India) Private Limited, 2008
2. T.J.E. Miller, ‘Brushless Permanent Magnet and Reluctance Motor Drives’, Clarendon Press,Oxford, 1989.
3. T. Kenjo, ‘Stepping Motors and Their Microprocessor Controls’, Clarendon Press London, 1984.
4.
R.Krishnan, ‘Switched Reluctance Motor Drives – Modeling, Simulation, Analysis, Design andApplication’, CRC
Press, New York, 2001.
5. P.P. Aearnley, ‘Stepping Motors – A Guide to Motor Theory and Practice’, Peter Perengrinus ,London, 1982.
6. T. Kenjo and S. Nagamori, ‘Permanent Magnet and Brushless DC Motors’, Clarendon Press, London, 1988.
7. K.Dhayalini, “Special Electrical Machines,” Anuradha Publications, 2017.
8. Google and Wikipedia
Kongunadu College of Engineering & Technology PMBLDC Motor