Brushless DC motor torque control
US4835448A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 28, 1987 |
| Grant date | May 30, 1989 |
| Priority date | — |
| Expiry date | Dec 28, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P6/085
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A control operates a permanent magnet brushless DC motor utilizing a phase advance signal to control motor torque. Input signals to the motor comprise a phase advance command signal and rotor position signals. The control provides switching signals to drive an inverter switch circuit to energize the motor. A start circuit is responsive to an analog rotor position signal and develops switching signals according to a preselected pattern stored in a memory. A run circuit compares a periodic sawtooth signal representing motor speed and a maximum desired phase advance, to a phase advance command signal to develop switching signals. The control switches from the start circuit to the run circuit at a preselected speed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.