Devices and methods for detecting islanding operation of a static power source
US7106564B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 23, 2002 |
| Grant date | Sep 12, 2006 |
| Priority date | — |
| Expiry date | Dec 10, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02J3/388
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Devices and methods for detecting islanding operation of a static power source involve injection of a non-harmonic error on the phase angle of the static power source in regular steps to introduce a very small intentional phase shift for the output voltage of the static power source in every voltage cycle which is corrected in each cycle in synchronization with the grid voltage in normal operation of the grid. In abnormal operation of a grid loss, this intentional small phase shift or error causes an intentional small frequency drift in each voltage cycle that continues in one cycle after another cycle. When the intentional frequency drift is over a preset level, a detection circuit starts to isolate the static power source from the grid to prevent islanding operation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.