Induction motor controller
US4629960A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 11, 1984 |
| Grant date | Dec 16, 1986 |
| Priority date | — |
| Expiry date | Dec 11, 2004 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P27/026
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A motor control apparatus is disclosed for controlling and reducing power consumption of a 3-phase induction motor, wherein the motor control apparatus includes control means for controlling current flow in each phase line and voltage sensing means across each control means for sensing back emf when the control means is electrically open in order to measure slip of the motor. A reference voltage signal representative of line voltage is subtracted from the summed back emf measurements in order to provide a voltage control signal which is a function of motor slip. Current measurement means in the form of a current transformer associated with one supply line is provided for measuring current drawn by the motor. The voltage control signal and the current signal are processed to develop a phase control signal for controlling a phase control means and a driver means associated with each control means. A starting control means for providing a soft start for the induction motor is also disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.