Method for determining output currents of frequency converter
US7190599B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 14, 2004 |
| Grant date | Mar 13, 2007 |
| Priority date | — |
| Expiry date | Oct 17, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M7/5395
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method for determining output currents of a three-phase frequency converter comprising a voltage intermediate circuit and three power switch pairs constituting an output of the frequency converter, wherein the power switches constituting a pair are coupled in series between a positive and a negative busbar of the voltage intermediate circuit so that a midpoint of each switch pair constitutes a phase output of the frequency converter. The method comprises, during use of the frequency converter, steps of forming a voltage reference vector for the output power switches such that only two switch pairs are modulated during one modulation sequence, controlling said two switch pairs to implement a voltage reference vector during the modulation sequence by using one zero vector, measuring current of the voltage intermediate circuit of the frequency converter at a predetermined moment in the modulation sequence, and changing actively, during use of the frequency converter, the zero vectors to be used in the modulation sequences.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.