Detection and mitigation of DC injection on the power grid system
US11462911B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 10, 2020 |
| Grant date | Oct 4, 2022 |
| Priority date | — |
| Expiry date | Sep 19, 2040 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY04S40/121
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The presence of injected DC has harmful consequences for a power grid system. A piecewise sinusoidal ripple voltage wave at the line-frequency that rides on the main capacitor bank of the power converter is observed. This observation leads to a new detection method and mitigation method. A two-stage control circuit is added to the operation of a power converter that controls power line impedance in order to mitigate the injected DC and to block DC circulation. This control computes a correction angle to adjust the timing of generated pulsed square waves to counter-balance the ripple. A functional solution and the results of experiments are presented. Furthermore, an extraction method and three elimination methods for this ripple component are presented to allow dissipation of DC energy through heat and/or electronic magnetic wave, or to allow transformation of this energy into usable power that is fed back into the power grid.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.