The Effect of Rotor Geometry on the Harmonic Performance of Synchronous Generators.
Abstract
The use of rotor geometry as a specification in the control of generator voltage and flux density harmonics is studied. The possibility of generating a specific voltage waveform at the load with only a three-phase rectifier between the AC generator and the load is investigated. The armature reaction MMF is expressed as an infinite set of traveling waves with an infinite set of velocities. It is shown that the rotor MMF cannot cancel armature reaction everywhere because the rotor MMF has only the velocity of the rotor. The MMFs present at all the stator slots of an armature coil group are reflected into a single slot in an attempt to control the air gap flux density harmonics be selectively positioning increments of rotor reluctance. This method fails because a general solution for the reflected flux densities could not be obtained. Specifying the air gap reluctance incrementally as the rotor moves under successive stator slots is also tried as a means of harmonic control. This method proves unworkable due to negative MMF requirements and conflicting geometry specifications. Finite Element analysis is introduced as a computer aid to the design of a magnetic structure. Recommendations for further study are included. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1980
- Accession Number
- ADA100813
Entities
People
- Cecil Stuerke
- David W. Nordquist
Organizations
- Air Force Institute of Technology