Transformer protection circuit and method
US9564753B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 6, 2015 |
| Grant date | Feb 7, 2017 |
| Priority date | — |
| Expiry date | Jul 26, 2035 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H3/52
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Systems and methods for protecting an electrical component in an alternating current system that includes a transformer are disclosed. In one aspect, a circuit includes a switch assembly connected between a transformer neutral of a transformer and a ground and having an open position and a closed position. In normal operation, the switch remains in a closed position. The circuit further includes a DC blocking component positioned in parallel with the switch assembly and connected between the transformer neutral and the ground, a voltage probe connected between the transformer neutral and ground and configured to monitor an instantaneous voltage level at the transformer neutral, and a control circuit configured to control the switch assembly, the control circuit including a sensor configured to actuate the switch assembly to an open position at least upon detection of a harmonic signal in at least one phase of the transformer or a predetermined threshold of DC or quasi DC current between the transformer neutral and the ground.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.