Switching controller directly operable from AC
US4495557A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 15, 1981 |
| Grant date | Jan 22, 1985 |
| Priority date | — |
| Expiry date | Dec 15, 2001 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S388/917
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A high response motor controller is disclosed which operates directly from a multi-phase AC power line without a DC link. The controller directly converts power from a fixed frequency multi-phase input to a D.C. or variable frequency output current. The output frequency is not limited by the AC power line frequency and the switching frequency is independent of the AC power line frequency. Controlled switching devices are connected between the multi-phase power input line and the power output line. Analog input signals are compared with signals representative of actual motor currents to produce current error signals. These current error signals control the conduction state of the controlled switching output transistors by a two state modulation process. The controlled switching output devices required to conduct the commanded motor current are selected by sensing and logically comparing the relative voltages of the various AC input line phases to utilize the phase lines having the greatest potential difference therebetween.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.