Apparatus for applying field excitation to a synchronous electric motor
US5565750A · kind A · utility
5Cited by
7References
18Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Aug 30, 1995 |
| Grant date | Oct 15, 1996 |
| Priority date | — |
| Expiry date | Aug 30, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P25/024
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The present invention provides a digital circuit for controlling application of DC excitation to the rotor field winding of a synchronous electric motor. The circuit detects the analog slip frequency of the motor and converts the analog signal to a digital signal. A digital timer produces a timing signal after a predetermined time interval. After the frequency of the slip signal has slowed sufficiently, as indicated by the timing signal, a control signal is supplied to a thyristor to gate the thyristor and provide DC excitation to the rotor field winding.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.