Medium voltage PWM drive and method
US5625545A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 1, 1994 |
| Grant date | Apr 29, 1997 |
| Priority date | — |
| Expiry date | Mar 1, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M1/0043
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An electric drive apparatus and method for controlling medium-voltage alternating current motors wherein a multi-phase power transformer having multiple secondary windings provides multi-phase power to multiple power cells, each of which have a single-phase output and are controllable by a modulation controller. The primary and secondary windings in the power transformer may be star- or mesh-connected; the secondary windings may be shifted in phase. Because the power cells are connected in series, the maximum output voltage for each cell may be less than the maximum line-to-line voltage. The power cells can have a tri-state output which can be controlled using pulse-width modulation techniques. AC input power is converted to DC output power for each output phase. Output power modulation can be produced by interdigitating a selected number of carrier signals so that harmonic components reflected back to the input are attenuated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.