Harmonic current monitoring in a wireless power system
US11967836B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 8, 2022 |
| Grant date | Apr 23, 2024 |
| Priority date | — |
| Expiry date | Aug 8, 2042 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M3/335
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Metal object detection may be performed in a wireless power system by monitoring the 5th or other order harmonic current of a dual-frequency power transmitter driven by a voltage-fed inverter with square-wave output. While power transfer is maintained by tuning at the fundamental frequency, the transmitter circuit is tuned simultaneously at the 5th order frequency or other harmonic frequencies to increase or decrease the flow of the harmonic current for when a metal object is present. The receiver circuit may include a notch filter to filter out the 5th order frequency. With the dual-frequency tuning configuration, the presence of a metal object causes a significant drop of the increase in the harmonic current at the transmitter side while the receiver behaves as an open circuit with no effect on power transfer. The harmonic tuning circuit may be switched off as necessary to leave only the fundamental frequency for power transfer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.