Combined solid-state and mechanically-switched transformer tap-changer
US5408171A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 23, 1994 |
| Grant date | Apr 18, 1995 |
| Priority date | — |
| Expiry date | Jun 23, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H9/541
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Disclosed is an End-Turn Solid-State Switching (ETSS) transfomer tap which makes use of a high-speed solid-state switching network to select either the end-turn lead or one of a number of non-isolated taps on a transformer regulating winding, and connects the selected tap to, while disconnecting the previously selected tap from, a single output conductor carrying the transformer load current. ETSS effectively changes the reference to one of the possible taps interfaced to a solid-state switching network. The same transformer regulating winding connected to ETSS can also be connected in series with a slow-speed mechanically-switched tap-changer (LTC). ETSS selects one connection point on the regulating winding while LTC operation selects the second point. A difference voltage is produced, depending on the number of turns between the ETSS selected tap and the LTC selected tap. The sign of the difference in voltage depends on whether the ETSS selected tap is higher or lower than the LTC selected tap. The difference or tap selected voltage is in series with the transformer load current. In one embodiment, the high-speed solid-state switching network uses a "Staggered Progression of Sol…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.