08-08-2012, 12:52 PM
Written-Pole Technology
WRITTEN- POLE TECHNOLOGY.pptx (Size: 286.92 KB / Downloads: 34)
Introduction
Traditional UPS and power quality solutions such as batteries and diesel generators pose costs and operational limitations.
Written-pole technology may be an economical alternative that offers reliable ride-through power as well as protection from transient power disturbances around the clock, protecting customers from costly losses.
An innovative patented technology
Precise Power Corp. of Bradenton, Florida is the industry leader in patented written-pole™ technology and with the support of EPRI, NRECA and utility partners. In early 1980s Precise Power set out to develop and commercialize a range of single-phase written-pole motors up to 75 hp in size.
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.
Starting Characteristics Of Written-Pole motor
The written-pole motor is a synchronous motor that inherently develops starting torque. The rotor magnetics are designed to allow the stator winding starting current to influence the magnet layer and provide hysteresis torque. A squirrel-cage is added under the magnet layer in the rotor for additional starting torque.
The high resistance rotor cage is designed for 20% slip or more and with the inherent hysteresis torque brings the rotor to partial speed before the motor exciter coil winding is energized. The exciter coil is energized with alternating current at line frequency writing a pole pattern in the rotor magnetic surface that is magnetically synchronous with the stator rotating field.