The document summarizes information about permanent magnet synchronous motors (PMSM). It discusses that PMSMs have higher efficiency and lower losses than conventional synchronous motors. It also describes how PMSMs are constructed, classified, operated, and controlled. The document provides equations for the electromotive force and torque of PMSMs. It also discusses linear transformation of rotating electrical machines and different control methods for PMSMs like unity power factor control and sensorless control.

1. PERMANENT MAGNET SYNCHRONOUS MOTOR
● The Permanent Magnet Synchronous
Motor (PMSM) is an AC synchronous
motor whose field excitation is
provided by permanent magnets and
that has a sinusoidal back EMF
waveform
● Has higher efficiency and lower losses
as compared to conventional
synchronous motor
● Has low-operational Costs
● Easy to control because of the use of
fast-switching semiconductor devices.

2. CONSTRUCTION

3. CLASSIFICATION OF MOTOR BASED ON THE DIRECTION OF THE MAGNETIC FLUX:
RADIAL FLUX MACHINE AXIAL FLUX MACHINE

4. OPERATION
● Not a self-starting motor
● When the supply is given,the rotor poles get attracted by the stator
poles and rotor starts moving in a clockwise direction.
● During the next half cycle of the armature current the stator poles
get interchanged.
● Torque changes direction for every half cycle due to the inertia of
the rotor and fast reversal of of the developed torque the rotor
cannot move and rests in the same direction
● If rotor’s speed is brought to synchronous speed by damper
windings or any external means, the stator and rotor poles gets
interlocked and the rotor continues to move at synchronous speed

5. EMF EQUATION:
TORQUE EQUATION

6. CONTROL OF
PERMANENT MAGNET
SYNCHRONOUS
MOTOR

7. LINEAR-TRANSFORMATION OF ROTATING ELECTRICAL MACHINE
● The process of replacing one set of variables to another related set of variables is called Linear
Transformation.
● It is also known as winding transformation or simply transformation.
● The transformation of 3-phase electrical quantities in two-phase quantities is usual practise to
simplify analysis of three-phase electrical circuits.
● 3 Phase a.c machines can be represented by 2-phase model provided the rotating winding rotor
& the stationary winding the stator can be expressed in a fictitious two axes coils

8. TYPES OF CONTROL
UNITY POWER FACTOR CONTROL
CONSTANT TORQUE ANGLE CONTROL
CONSTANT MUTUAL FLUX LINKAGE CONTROL
OPTIMUM TORQUE PER AMPERE CONTROL
CONSTANT TORQUE ANGLE CONTROL
SENSORLESS CONTROL

9. CONSTANT TORQUE ANGLE CONTROL UNITY POWER FACTOR CONTROL
● Torque angle is maintained constant
● Speed of operation is lower than the base speed.
● This implies that the VA rating of the inverter is fully
utilised for real power input to PMSM.
● Torque here is controlled as a function of motor
variable

10. SENSORLESS CONTROL

11. SYNCHRONOUS RELUCTANCE MOTOR
● A synchronous motor in which only reluctance
torque is developed is called the synchronous
reluctance motor.
● It has high reliability,low cost,rigidity in
hostile environment and a desirable
torque-speed characteristics
● High efficiency
● High output power capability

12. CONSTRUCTION
ROTOR CONSTRUCTION STATOR CONSTRUCTION
● Rotor should be constructed such that the armature Inductance
varies sinusoidally
● The inductance should be maximum along the direct axis and
minimum along the quadrature axis
● As the developed reluctance torque is proportional to the difference
between direct axis and the quadrature axis synchronous
inductance should be as high as possible
● To achieve maximum value for the difference several rotors are
developed
● Rotors can be classified as Segmental, Radially laminated and
axially laminated
● Stator frame is used to hold the armature core
● Armature core is built up of laminations of the ferromagnetic steel
sheets.
● The core is laminated to minimize the loss due to the eddy currents.
● Slots for housing the armature conductors are provided along the
inner periphery of the armature,semi-closed slots are generally
used
● The armature carries 3-phase winding and arranged for the
required number of poles
● Distributed type winding is used in SyRM

13. TORQUE EQUATION OF A SyRM
OPERATION
● When the stator windings are excited with a three-phase supply, they produce a rotating magnetic field in the
stator windings.
● The magnetic field rotates at a synchronous speed based on the number of poles and frequency. The
fundamental concept behind the reluctance motor is the reluctance principle.
● The rotor windings are of squirrel cage in shape just like in induction motor. When the rotor windings are
excited with DC supply, they produce a magnetic field at rotor windings.
● Now we have two magnetic fields, one is the stator magnetic field and the other one is the rotor magnetic
field. The stator magnetic field is rotating at a speed of synchronous speed.
● Now the rotor windings are constructed in such a manner that, when the stator magnetic field tries to align
with the rotor magnetic field, it forms a minimum reluctance path.
● For that minimum reluctance path, the rotor tries to align itself with the stator magnetic field, and in that
process, it gets magnetically locked with a stator magnetic field.
● If the stator magnetic field is rotating at synchronous speed, the rotor also rotates are synchronous speed.
● In case of any overloads, the rotor comes out of magnetic locking. The rotor axis falls out of synchronism.
Then immediately, there is the production of damping torque in the damper windings.
● The damper windings try to bring the rotor back to magnetic locking. This phenomenon is called hunting.
Which is more dominant in a synchronous motor.
● The machine tries to hunt the synchronous state. Once the rotor is back to the magnetic locking, the damping
torque or synchronizing torque disappears. The same can be concluded for underloads.

14. CONTROL OF SyRM: VECTOR CONTROL

15. APPLICATIONS OF PMSM
AEROSPACE AC COMPRESSORS
AUTOMATIC STEERING WHEEL MACHINE TOOLS

16. THANK YOU :)