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Title: Method and apparatus for pulse width modulation control of an AC induction motor

Abstract

An inverter is connected between a source of DC power and a three-phase AC induction motor, and a micro-processor-based circuit controls the inverter using pulse width modulation techniques. In the disclosed method of pulse width modulation, both edges of each pulse of a carrier pulse train are equally modulated by a time proportional to sin .THETA., where .THETA. is the angular displacement of the pulse center at the motor stator frequency from a fixed reference point on the carrier waveform. The carrier waveform frequency is a multiple of the motor stator frequency. The modulated pulse train is then applied to each of the motor phase inputs with respective phase shifts of 120.degree. at the stator frequency. Switching control commands of electronic switches in the inverter are stored in a random access memory (RAM) and the locations of the RAM are successively read out in a cyclic manner, each bit of a given RAM location controlling a respective phase input of the motor. The DC power source preferably comprises rechargeable batteries and all but one of the electronic switches in the inverter can be disabled, the remaining electronic switch being part of a "flyback" DC-DC converter circuit for recharging the battery.

Inventors:
 [1];  [2]
  1. (Bloomfield Hills, MI)
  2. (Union Lake, MI)
Publication Date:
OSTI Identifier:
865073
Patent Number(s):
US 4458194
Assignee:
Eaton Corporation (Cleveland, OH) OSTI
DOE Contract Number:  
DEN 3-211
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
method; apparatus; pulse; width; modulation; control; induction; motor; inverter; connected; source; dc; power; three-phase; micro-processor-based; circuit; controls; techniques; disclosed; edges; carrier; train; equally; modulated; time; proportional; theta; angular; displacement; center; stator; frequency; fixed; reference; waveform; multiple; applied; phase; inputs; respective; shifts; 120; degree; switching; commands; electronic; switches; stored; random; access; memory; locations; successively; cyclic; manner; bit; location; controlling; input; preferably; comprises; rechargeable; batteries; disabled; remaining; switch; flyback; dc-dc; converter; recharging; battery; random access; width modulation; access memory; carrier wave; rechargeable batteries; angular displacement; circuit controls; motor stator; electronic switches; dc-dc converter; disclosed method; induction motor; pulse train; phase shift; dc power; pulse width; power source; preferably comprises; phase shifts; phase input; respective phase; source preferably; modulated pulse; fixed reference; electronic switch; cyclic manner; modulation techniques; modulation control; preferably comprise; /318/363/

Citation Formats

Geppert, Steven, and Slicker, James M. Method and apparatus for pulse width modulation control of an AC induction motor. United States: N. p., 1984. Web.
Geppert, Steven, & Slicker, James M. Method and apparatus for pulse width modulation control of an AC induction motor. United States.
Geppert, Steven, and Slicker, James M. Sun . "Method and apparatus for pulse width modulation control of an AC induction motor". United States. https://www.osti.gov/servlets/purl/865073.
@article{osti_865073,
title = {Method and apparatus for pulse width modulation control of an AC induction motor},
author = {Geppert, Steven and Slicker, James M.},
abstractNote = {An inverter is connected between a source of DC power and a three-phase AC induction motor, and a micro-processor-based circuit controls the inverter using pulse width modulation techniques. In the disclosed method of pulse width modulation, both edges of each pulse of a carrier pulse train are equally modulated by a time proportional to sin .THETA., where .THETA. is the angular displacement of the pulse center at the motor stator frequency from a fixed reference point on the carrier waveform. The carrier waveform frequency is a multiple of the motor stator frequency. The modulated pulse train is then applied to each of the motor phase inputs with respective phase shifts of 120.degree. at the stator frequency. Switching control commands of electronic switches in the inverter are stored in a random access memory (RAM) and the locations of the RAM are successively read out in a cyclic manner, each bit of a given RAM location controlling a respective phase input of the motor. The DC power source preferably comprises rechargeable batteries and all but one of the electronic switches in the inverter can be disabled, the remaining electronic switch being part of a "flyback" DC-DC converter circuit for recharging the battery.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1984},
month = {1}
}

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