Pulse width modulated inverter system for driving single phase a

Details Pulse width modulated inverter system for driving single phase a Pulse width modulated inverter system for driving single phase a

1985-11-29

1987-03-17

Smith, Jr., David

Electricity: motive power systems

Induction motor systems

Primary circuit control

318749, 318800, 318812, H02P 540

Patent

active

046510796

ABSTRACT:
A sinusoidally weighted pulse width modulated switching signal may be developed, for operating an inverter to apply sinusoidal voltage to a single phase a-c induction motor, by comparing a triangular voltage waveform of fixed frequency with a variable frequency sine wave voltage, the switching signal varying between its high and low states whenever the triangular waveform and modulating sine wave intercept one another. A constant ratio of the amplitude of the sinusoidal motor voltage relative to the voltage's frequency, and thus motor speed, may be obtained simply by translating the sinusoidal modulating waveform through a high pass filter before it is compared with the triangular wave. By setting the filter cut-off frequency above the operating frequency range (preferably from about 12 to 60 hertz) of the sine wave generator, the sine wave voltage will be attenuated by the filter in an amount inversely proportional to the sine wave frequency. In this way, the amplitude of the sine wave will vary in step with, and directly proportional to, frequency changes to achieve a constant motor voltage/frequency ratio.

REFERENCES:
patent: 3343063 (1967-09-01), Keeney et al.
patent: 3527990 (1970-09-01), Gasser
patent: 3560834 (1971-02-01), Studtmann
patent: 3760248 (1973-09-01), Nola et al.
patent: 4080554 (1978-03-01), Nordby
patent: 4320331 (1982-03-01), Plunkett
patent: 4333042 (1982-06-01), Kawada et al.
patent: 4408268 (1983-10-01), Peters et al.
patent: 4491778 (1985-01-01), Knox et al.

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