Phase shifting transformer with low zero phase sequence impedance
US5982262A · kind A · utility
Inventor
Key dates
| Filing date | Dec 8, 1997 |
| Grant date | Nov 9, 1999 |
| Priority date | — |
| Expiry date | Dec 8, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01F30/12
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A phase shifting transformer or autotransformer for a three phase power distribution network in which selected outputs have a low zero phase sequence impedance. At least one low zero phase sequence impedance output is fed by a plurality of windings distributed amongst the three core legs such that the number of turns of windings generating a flux in the positive direction is substantially equal to the number of turns of windings generating a flux in the negative direction. Thus, according to the invention, the transformer may be provided with any necessary phase shifting angles between different harmonic sources, with some or all outputs having a low zero phase sequence impedance to reduce voltage distortion created by zero phase sequence harmonics.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.