Simplified quasi-harmonic neutralized high power inverters
US4870557A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 23, 1988 |
| Grant date | Sep 26, 1989 |
| Priority date | — |
| Expiry date | Sep 23, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M7/49
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A quasi-harmonic neutralized static power converter comprises one or more threephase phase shifting transformers having open primary windings fed at opposite ends by poles in separate ones of an associated pair of six-pulse bridge inverter circuits. The secondary winding of at least one of the phase shifting transformers is a delta winding or a wye winding connected to a neutral line. In order to block zero sequence currents which would be induced in such secondaries, a zero sequence blocking transformer is inserted in either the primary of secondary of any one of the phase shifting transformers. Preferably, the zero sequence blocking transformer has three identical zero sequence blocking windings wound on a common core. Each of the zero sequence windings is connected in series with a separate one of the windings in the selected transformer primary or secondary. In the case of a wye secondary connected to a neutral line, a single zero sequence winding in the neutral line can block the zero sequence current in all three phases.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.