2. Electrical machine
• A electrical machine consumes electrical energy to do
a specific work or it convert electrical energy to other
forms like mechanical energy, light energy, heat etc.,
3. Special Electrical Machines Types
Permanent Magnet DC Motor
1. PM synchronous motor
2.PM brushless DC motor
Reluctance motors
3. Synchronous reluctance
4.Switched Reluctance
Stepping motors
5. Single stack multi-machine
6. Multi stack multi-machine
14. PMSM
• Depending on how magnets are attached to the
rotor, PMSM motors can be classified into
• Two types: Surface PMSM (SPMSM) and
interior PMSM (IPMSM).
• Permanent Magnet Synchronous Motor,
PMSM is a kind of synchronous motor in
which permanent magnet is used as rotor to
create field poles. No field winding is wound
on the rotor.
15. of Switching power
1950’s
• Advent
transistor
replaced
and SCR in
the
with
mechanical
electrical
in the form of
commutator
commutator
inverter.
PMSM
16. • The main advantage when
compared with the conventional
synchronous
elimination of the field
machine is the
coil, dc
supply, and slip rings; hence, lower
loss and a less complex motor.
PMSM
17. INTRODUCTION
A permanent magnet synchronous motor is also called as
brushless permanent magnet sine wave motor. A sine
wave motor has a
1. Sinusoidal or quasi-sinusoidal distribution of magnetic
flux in the air gap.
2. Sinusoidal or quasi-sinusoidal current wave forms.
3. Quasi-sinusoidal distribution of stator conductors (i.e.)
short-pitched and distributed or concentric stator
windings.
18.
19. Construction
• The basic construction of PMSM is same as that of
synchronous motor. The only difference lies with the
rotor. Unlike synchronous motor, there is no filed
winding on the rotor of PMSM. Field poles are
created by using permanent magnet. These Permanent
magnets are made up of high permeability and high
coercivity materials like Samarium-Cobalt and
Neodium-Iron-Boron. Neodium-Iron-Boron is mostly
used due to its ease of availability
effectiveness. Theses permanent magnets
and cost
are
mounted on the rotor core.
20. Working principle
• The working principle of permanent magnet synchronous
motor is same as that of synchronous motor. When three phase
winding of stator is energized from 3 phase supply, rotating
magnetic field is set up in the air gap. At synchronous speed,
the rotor field poles locks with the rotating magnetic field to
produce torque and hence rotor continues to rotate.
• As we know that synchronous motors are not self starting,
PMSM needs to be started somehow. Since there is no winding
on the rotor, induction windings for starting is not applicable
for such motors and therefore variable frequency power supply
for this purpose.
21. Application:
Permanent Magnet Synchronous Motor can be used as an
alternative for servo drives. It is widely used in various
industrial application viz. robotics, traction, aerospace etc.
