Method and apparatus for controlling induction motor for compressor
US5119071A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 5, 1991 |
| Grant date | Jun 2, 1992 |
| Priority date | — |
| Expiry date | Mar 5, 2011 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF04B2203/0207
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
DC power is supplied to an induction motor for a compressor by switching ON/OFF in response to a modulated voltage waveform obtained from modulating waves which are used for generating AC power for energizing an induction motor and a carrier wave according to PWM theory. The compressor has a compressing element rotated by the induction motor, and the modulating wave is corrected according to a rotational angle of the compressing element. A sine wave having the same frequency as the modulating wave is added to the modulating wave, and a phase of the sine wave is controlled so that a maximum value of the sine wave corresponds to the compression stage of the compressing element. Thus, a rotation speed of the compressing element is constant in a suction stage and a compression stage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.