Anti-islanding detection for three-phase distributed generation
US9634673B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 16, 2013 |
| Grant date | Apr 25, 2017 |
| Priority date | — |
| Expiry date | Jan 6, 2036 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02J3/388
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Wobbling the operating frequency of a phase-locked loop (PLL), preferably by adding a periodic variation is feedback gain or delay in reference signal phase allows the avoidance of any non-detection zone that might occur due to exact synchronization of the phase locked loop operating frequency with a reference signal. If the change in PLL operating frequency is periodic, it can be made of adequate speed variation to accommodate and time requirement for islanding detection or the like when a reference signal being tracked by the PLL is lost. Such wobbling of the PLL operating frequency is preferably achieved by addition a periodic variable gain in a feedback loop and/or adding a periodically varying phase delay in a reference signal and/or PLL output.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.