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37345962-Written-Pole-Technology

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					 WRITTEN-POLE
ELECTRIC MOTORS
       Presented by:
       Nidhi Pansari (3rd elec)
       Preeti Baid (3rd elec)
          CONTENTS
•LIMITATIONS OF CONVENTIONAL
TECHNOLOGY
•CONSTRUCTION
•WRITTEN-POLE TECHNOLOGY
•OPERATION
•OPERATIONAL BENEFITS
•ADVANTAGES
•WEATHER CONDITIONS
•APPLICATIONS
•CONCLUSION


                               2
       LIMITATIONS OF
  CONVENTIONAL TECHNOLOGY

1.Dependence of speed on no. of poles of
   rotor.
       speed = 120 X frequency
                  no. of poles
2.The machine must have even no. of poles
   and deviating from this condition will
   cause unstability at its rated speed.
     AN INNOVATIVE
  PATENTED TECHNOLOGY
• In the 1990’s, with support from the
  EPRI, the Precise Power Corporation
  of Bradenton, Florida, developed a
  new concept in electric motors called
  the Written Pole® electric motor.
          WRITTEN-POLE
          TECHNOLOGY
• The patented Written-Pole® Technology allows the
  magnetic pole pattern on the magnet layer to be
  changed to a desired pattern while the machine is
  rotating and therefore breaks the relationship
  between rotor speed and output frequency.
CONSTRUCTION




               Contd..
• Written Pole motors use similar
  construction techniques found in
  conventional motors.
• A continuous layer of ferrite magnets on
  the surface of the rotor, along with a
  high-density exciter winding contained
  within the stator winding .
• The basic platform consists of a
  conventional steel shaft inserted into a
  lamination stack containing a high
  resistance rotor cage.

                                     Contd…
• The high resistance cage is a key factor in
  limiting the starting current of Written-
  Pole motors.
• The stator lamination stack is constructed
  using low loss electrical steel laminations.
• The concentrated excitation windings are
  contained within the stator structure and
  are located between the main stator
  windings.
         OPERATION

• A written-pole motor employs one of
  three modes of operation based on the
  rotational speed of the machine:
    1. START MODE
    2. WRITTEN POLE MODE
    3. RUN MODE
.
            OPERATIONAL
              BENEFITS
Feature                Conventional   WP
Speed                  3,560rpm       3600 rpm
Efficiency             85%            93%
Power factor           90.5%          100%
Full-load power        53kW           40kW
Full-load torque       73.7 ft-lb     73 ft-lb
Starting torque        88 ft-lb       82 ft-lb
Full-load current      219 amps       173 amps
Locked rotor current   1450 amps      312amps
Cost (p.u.)            1.0            1.2
         ADVANTAGES
1. Low starting current requirements
2. Energy efficient operation
3. Unity power factor operation
4. Simple construction
5. Low temperature rise
6. High inertia starting
7. Instantaneous restart capability
8. Ride through characteristics
9. Three-phase applications
  WEATHER CONDITIONS

• The Written-Pole motor is designed to
  operate in ambient temperatures ranging
  from 32ºF to 104ºF.
• However,test results show that Written-
  Pole motors have reliably operated in
  temperatures ranging from 42ºF to 122ºF.
• They may be operated safely in the open air
  if there is adequate protection from direct
  rain.The motor base must be mounted on
  a raised concrete pad or steel frame to
  avoid exposure to standing water.
A WRITTEN POLE RIDE THROUGH
   MOTOR USED IN A FARM
         APPLICATIONS
• Regulation of output voltage and frequency in
  electric generators,without relying on external
  regulators or power electronics.
• In a family of single and three-phase motive power
  and power protection systems used by many
  customers including the US Weather
  Service,NASA,Federal Aviation Authority,US Air
  Force and many commercial and industrial
  customers.
• To create a simple,rugged power protection unit
  combining Written-Pole motors and generators
  with an integral flywheel
      AWARD WINNING
       TECHNOLOGY

• A recipient of the R&D 100 Award in 1994,
  Written-Pole technology was recognized
  by R&D Magazine as one of that year's
  most technologically significant
  innovations.
• The technology has also been recognized
  by numerous technical organizations
  including the Professional Society of
  Engineers in the United States.
           CONCLUSION

• The written-pole motor, developed by
  Precise Power Corporation, is a motor
  design that allows for the operation of very
  large single-phase motors.
• This unique product has applications
  virtually anywhere that three-phase power
  is either not available, or is not economical
  to provide.
• This motor technology has the additional
  benefit of being able to ride through brief
  service interruptions on single-phase power
  lines.
THANK
 YOU!
WRITTEN POLE TECHNOLOGY

				
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