An Analysis of Noise Reduction in Variable Reluctance Motors Using Pulse Position Randomization

Abstract

The design and implementation of a control system to introduce randomization into the control of a variable reluctance motor (VRM) is presented. The goal is to reduce noise generated by radial vibrations of the stator. Motor phase commutation angles are dithered by 1 or 2 mechanical degrees to investigate the effect of randomization on acoustic noise. VRM commutation points are varied using a uniform probability density function and a 4 state Markov chain among other methods. The theory of VRM and inverter operation and a derivation of the major source of acoustic noise are developed. The experimental results show the effects of randomization. Uniform dithering and Markov chain dithering both tend to spread the noise spectrum, reducing peak noise components. No clear evidence is found to determine which is the optimum randomization scheme. The benefit of commutation angle randomization in reducing VRM loudness as perceived by humans is found to be questionable

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Document Details

Document Type
Technical Report
Publication Date
May 01, 1994
Accession Number
ADA283846

Entities

People

  • Melissa C. Smoot

Organizations

  • Massachusetts Institute of Technology

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Communities of Interest

  • Advanced Electronics
  • Energy and Power Technologies
  • Ground and Sea Platforms
  • Sensors

DTIC Thesaurus Topics

  • Air Gaps
  • Computer Programming
  • Computer Programs
  • Computer Science
  • Computers
  • Control Systems
  • Detectors
  • Electrical Engineering
  • Engineering
  • Field Effect Transistors
  • Hall Effect
  • Hall Effect Sensors
  • Measurement
  • Power Electronics
  • Random Number Generators
  • Resonant Frequency
  • Semiconductors

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  • Electrical Engineering
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