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IARU Region 1 President Warns of Wireless Power Transfer Interference Threat


IARU Region 1 President Don Beattie, G3BJ, is expressing concern that Wireless Power Transfer for Electric Vehicles — also referred to as WPT(EV) — equipment could pose a threat to Amateur Radio spectrum. WPT(EV), which typically uses frequencies in the LF and MF range, allows the charging of electric vehicle batteries without having to “plug in” to a power source.

“WPT(EV) is high duty cycle, located in residential areas, and its harmonics are likely to be spread across a band of frequencies,” Beattie explained in a briefing, Wireless Power Transmission for Electric Vehicles – WPT(EV). Beattie fears that WPT(EV) could end up being installed at residences of electric vehicle owners, generating noise that could obscure radio communications in and around the home environment.

“Many non-radio devices are coming on stream, which emit high levels of wideband ‘radio noise’ which can mask essential communications,” the latest technology being WPT(EV), Beattie said in a post on his website, The Threats to Radiocommunication. “It is rather like a thick fog which prevents us seeing things at any distance. So, it is that the radio spectrum is being polluted in a way which, if unchecked, will radically reduce its usefulness.”

Beattie said that, in his role as IARU Region 1 President, he has been heavily involved in discussions on this technology. He pointed to a IARU Region 1 white paper, Unwanted Emissions in the Spurious Domain from Wireless Power Transfer For Electric Vehicles on Frequencies Allocated to the Amateur Service, which seeks the support of other countries “to ensure that spurious emission limits are set for WPT(EV), which will protect incumbent radio services in the urban/suburban residential environment.”

World Radiocommunication Conference (WRC-19) agenda item 9.1.6 calls for “urgent studies” of WPT(EV) to assess its impact on radiocommunication services and to study suitable harmonized frequency ranges that could minimize its impact on the radio spectrum. In a 2016 report, Applications of wireless power transmission via radio frequency beam, the International Telecommunication Union (ITU) called WPT “game-changing” technology. “We will be able to become free from lacking electric power when [it] will be supplied wirelessly,” the report said.

WPT(EV) would operate using inductive coupling from a charging “pad” on the floor beneath the vehicle. “Whilst the technology is still under development, some installations for public service vehicles (buses) are already in operation, using charging frequencies around 20 kHz,” Beattie said. “Discussions are under way in CEPT [European Conference of Postal and Telecommunications Administration], CISPR [International Special Committee on Radio Interference], and ITU over the introduction of Wireless Power Transmission for Electric Vehicles on a widespread basis across Europe.” Domestic charging systems are expected to use a frequency around 85 kHz, and Beattie said this poses a real risk to radio communication resulting from the harmonics that the high-power WPT(EV) installations would generate.

“It is not yet clear what the actual spurious performance of WPT(EV) will be, but it is clear that to provide adequate protection to radio services…in the residential environment, the existing limits will need to be tightened very significantly,” the IARU Region 1 white paper asserted.




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