Motor starting and switching
US7812563B2 · kind B2 · utility
Inventors
Key dates
| Filing date | Sep 12, 2005 |
| Grant date | Oct 12, 2010 |
| Priority date | — |
| Expiry date | Jan 8, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P1/029
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method of starting and apparatus for starting a multiphase electrical machine is disclosed. The aim is to reduce oscillatory pulsation in torque generated by the motor and inrush current that occurs shortly after start-up. The starting method comprises the steps of first connecting at least one, but less than all, of a plurality of windings to a respective phase-shifted supply voltage at a controlled point in the supply phase. Then, after a controlled delay following the first connection, connecting the or each remaining winding of the machine a respective phase-shifted supply voltage. The invention has particular application to multiphase (most usually, 3-phase) motors. However, it can also be applied to other electrical machines, such as generators and transformers. The method can be performed at initial start-up or, in the case of application to a motor, at Y-delta switchover.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.