Control apparatus for an induction motor
US4785225A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 7, 1987 |
| Grant date | Nov 15, 1988 |
| Priority date | — |
| Expiry date | Oct 7, 2007 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/72
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A control apparatus for an induction motor comprises a variable voltage, variable frequency inverter feeding the motor, which is controlled by the PWM control. A secondary current component and an exciting current component of the motor are obtained by the calculation on the basis of a motor current and an actual slip frequency of the motor. From the thus obtained secondary current component, an actual torque produced by the motor is calculated. A frequency reference for the PWM control is obtained by the comparison result of the actual torque and a torque reference. A modulation factor reference for the PWM control is obtained by the comparison of the exciting current component and an exciting current reference. According to this control apparatus, the torque of the induction motor can be controlled to follow the torque reference with a high accuracy.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.