Variable frequency power converter for ac motor drive
US3939387A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 19, 1974 |
| Grant date | Feb 17, 1976 |
| Priority date | — |
| Expiry date | Apr 19, 1994 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P2201/03
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
In a variable frequency power converter of a current type for driving an AC motor including a rectifier, an inverter, and a smoothing reactor disposed on a DC transmission line between the rectifier and the inverter, there are provided a series circuit having a switching circuit and a smoothing capacitor on the DC input side of the inverter and a feedback circuit having controlled rectifier elements and commutation reactors for feeding back the reactive power of the AC motor. The power converter operates as a current type converter until the output frequency of the converter reaches a predetermined value under the condition that the switching circuit and the controlled rectifier elements are non-conductive, and operates as a voltage type converter when the output frequency has reached the predetermined value under the condition that the switching circuit and the controlled rectifier elements are conductive.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.