Radio frequency interference measurements of wireless power transfer for electrical vehicles
Publish date: 2023-03-06
Report number: FOI-R--5430--SE
Pages: 64
Written in: English
Keywords:
- WPT
- wireless power transfer
- electromagnetic interference
- radio frequency interference
- interference
Abstract
Wireless power transfer (WPT) is a collective term for transmitting energy wirelessly. This work is a part of a measurement campaign to measure the electromagnetic emission from potential interference sources, with the long-term goal to assess its impact on radio communication systems nearby. Another goal is to gain knowledge about the emission levels radiated by the WPT station and the characteristics of the potential electromagnetic interference signals. This report presents results for stationary charging of vehicles using inductive wireless charging. The measurements cover 9 kHz-1 GHz, with additional measurement around GPS L1 (1575.42 MHz) and GPS L2 (1227.60 MHz). Measurements are made on five different measurement cases: background noise environment, charging system in stand-by, but no vehicle charging, vehicle (not charging), vehicle charging, and two vehicles charging simultaneously. The overall conclusion is that the WPT station is emitting interference, in particular at frequencies up to 30 MHz, when it is charging. The charging frequency at 85 kHz is clearly seen in the measurements and at frequencies between 60 kHz and 30 MHz, a distinct effect from the charging vehicle is evident. There are disturbances at higher frequencies, but the levels are lower and it is not as evident, as for lower frequencies, that they originate from the WPT station.