Power supply for measuring the line impedance of underground cable
US7023675B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 9, 2003 |
| Grant date | Apr 4, 2006 |
| Priority date | — |
| Expiry date | Jan 26, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01F30/02
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Disclosed is a power supply for measuring the line impedance of an underground cable, which includes an input terminal section having a plurality of input terminals, a plurality of autotransformers, a transformer adjustment tap, a plurality of 3rd-harmonics cancellation transformers, and an output terminal section having a plurality of output terminals. The autotransformers are connected respectively to the input terminals. The transformer adjustment tap is connected to all of the autotransformers. The 3rd-harmonics cancellation transformers are connected respectively to the autotransformers. The output terminals are connected respectively to the 3rd-harmonics cancellation transformers. The autotransformers are simultaneously controlled by the transformer adjustment tap so as to uniformly boost the powers supplied respectively to the autotransformers, and 3rd-harmonics of the powers are cancelled in the 3rd-harmonics cancellation transformers to remove noise, so that the powers are stably applied respectively to the phases of the underground cable.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.