Electronic apparatus for positioning and using AC motors
US4088938A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 17, 1976 |
| Grant date | May 9, 1978 |
| Priority date | — |
| Expiry date | Dec 17, 1996 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05D3/18
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A solid-state valve actuator control system using three-phase AC motors as prime movers having a summing point with a set point input, a position feedback input and a velocity feedback input. Velocity feedback being produced by differentiating position feedback. Summing point output error signal provides input to each of three integrators. Integrator outputs, synchronized with the three-phase AC power input, supply control signals to an AC solid-state power bridge having as its power input three-phase AC and as its power output controlled three-phase AC to drive three-phase AC motors in the proper direction. For small errors, the AC drive supplied to the prime mover is proportional to the magnitude of the error. For large errors, full voltage is applied to the prime mover. Motor transients are minimized by the proportional band on start-up and on motor reversal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.