Method and apparatus for starting polyphase dc motor
US5572097A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 15, 1994 |
| Grant date | Nov 5, 1996 |
| Priority date | — |
| Expiry date | Jul 15, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P6/12
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
In a method for aligning a rotor of a polyphase dc motor in preparation for starting the motor. a first energization signal is applied to field coils of the motor in a first predetermined phase for a first predetermined time. Then, a second energization signal having a second predetermined phase displaced from the first phase by a predetermined amount is applied to the field coils for a second predetermined time period. In one embodiment, the second energization signal is applied to produce a maximum torque upon the rotor when the rotor is positioned at a location determined by the first energization signal. In the case of a three phase motor, the second energization signal is displaced by two commutations from the first energization signal. Circuitry for aligning a rotor of a polyphase dc motor in preparation for startup is also presented having circuitry for applying a first signal to selected field coils of the polyphase dc motor having a first commutative phase for a first predetermined time, and circuitry for applying a second signal to other selected field coils of the polyphase dc motor having a second commutative phase for a second predetermined time.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.