Constant speed and frequency generating system
US4806841A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 29, 1988 |
| Grant date | Feb 21, 1989 |
| Priority date | — |
| Expiry date | Feb 29, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P9/42
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An output frequency control circuit is mounted on the rotating shaft connecting a motor and generator. The motor-generator system includes exciter circuits, an input power factor control and an output voltage regulator. The input power factor control ensures that the motor input power factor is unity, which is desirable for motor control. The frequency control circuit responds to variations in the AC power source frequency by generating low frequency excitation to boost or buck the operational speed of the machine, causing the generator output frequency to remain constant at a selected frequency output irrespective of input power source frequency variation. The output frequency may be selected over a given range from a control panel adjustment pot. The major innovation is that the entire frequency control circuit is shaft-mounted and requires no slip-rings or magnetic transformers for signal transfer, thus reducing the possibilities of mechanical failure. A second innovation is that the motor input power factor is held at unity. A third innovation is that the system is enabled to ride through `brownouts` or short term input power failure.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.