EVALUATION OF POLE FACE LOSSES FOR THE 467 KVA EXPERIMENTAL GENERATOR
Abstract
The pole face losses associated with the alternating flux density that is produced by the slot and teeth in the armature for the 467 kva experimental generator were experimentally evaluated by using an eddy-current dynamometer. The design factors which influence pole face losses in the generator were duplicated in the test fixture as close as possible. Centrifugal stress in the rotor limited the tooth ripple frequency to one-half the tooth ripple frequency of the generator and it was necessary to extrapolate the data from 24,000 cps to 48,000 cps to determine the pole face losses at these conditions. No attempt was made to control the temperature of the pole faces. Therefore, the test results had to be corrected for a change of resistivity since the pole faces will operate at a much higher temperature in the generator. A complete analysis of the pole face loss problem based upon theoretical considerations is presented in the report. The problem of dealing quantitatively with the magnetic flux density distribution at the surface of the poles is treated analytically. Harmonic frequencies and the losses due to each harmonic frequency were considered. The effect of grooves in the pole faces were also considered in the theoretical analysis. The theoretical equations show that the eddy-current losses are a function of permeability of the pole face material. In the actual problem this quantity is a variable and a method for determining the applicable value of this variable is presented.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1967
- Accession Number
- AD0809319
Entities
People
- Carroll C. Kouba
- Jack L. Mccabria
Organizations
- Westinghouse Electric Corporation