Method for power control of an electric motor
US7342372B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 5, 2005 |
| Grant date | Mar 11, 2008 |
| Priority date | — |
| Expiry date | Mar 9, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P23/26
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The invention relates to a method for power control of an electric motor, in particular a motor for driving the suction fan of a vacuum cleaner connected to an AC mains power supply. The power control is effected by varying the phase angle of the electric alternating quantity supplied to the motor by the use of semiconductor switches. AC power supplied to the motor is switched by using different delay times for the switching in each half-period of a full AC period to suppress odd harmonics, particularly the third harmonic of the mains power line frequency. Half-periods of a full period are mirrored in the next consecutive full period in order to suppress even harmonics, particularly the second harmonic of the mains power line frequency. A set of delay times t1 and t2 are defined and selected to be used in further avoiding critical delay time areas for harmonics and minimize the generation of vibrations.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.