Digital induction motor control system
US4361792A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 6, 1980 |
| Grant date | Nov 30, 1982 |
| Priority date | — |
| Expiry date | May 6, 2000 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02J3/1892
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A digital self-calibrating power factor controller for an AC induction motor. During start-up a first number corresponding to the actual phase angle between motor voltage and current is determined and compared with a second number corresponding to a desired delay in energizing the motor. The second number is varied until both numbers are approximately equal. A third number corresponding to a desired phase angle is determined and stored and the system switches from start-up to run. The first number corresponding to the actual phase angle is now compared with the third number corresponding to the desired phase angle. The second number corresponding to a desired delay is now varied with motor load so as to keep the actual phase angle equal to the desired phase angle.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.