Apparatus for controlling electric motor
US4788485A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 23, 1987 |
| Grant date | Nov 29, 1988 |
| Priority date | — |
| Expiry date | Mar 23, 2007 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B70/10
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A control apparatus for controlling the main circuit for driving an AC electric motor consisting of a diode converter and a pulse width modulation (PWM) power converting device, in which it is arranged that the DC current as the output of the diode converter is detected by a current detector, the AC component of this DC current is filtered through a high-pass filter, and a pulse-width-modulation control is exercised by a control circuit in response to the output of the high-pass filter so that the DC current as the output of the diode converter may be smoothed out in the main circuit by the PWM power converting device. By such arrangement, this control apparatus of an electric motor is made smaller in size and simplified in structure and enabled to control the power factor of the power source of the diode converter to close to 1.0.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.