The sale of electric vehicles (EVs) continues to accelerate around the world as both governments and consumers seek vehicular transportation options that contribute to the reduction in greenhouse gas emissions. But for many, aspects of the emerging charging infrastructure required to power EVs may come with an unwelcome threat to legacy AM radio broadcasting.
According to an extensive article posted last month to the website of RadioWorld, wireless power transfer systems for electric vehicles (WPT-EV) rely on the use of switching frequencies that generate harmonic interference in the lower AM band. Specifically, WPT-EV charging can produce harmonics in several frequency bands, including 148.5-283.5 kHz, 525-1705 kHz, and 2300-26100 kHz, resulting in interference with the reception of broadcasts using these frequencies.
Electromagnetic interference (EMI) generated by wired EV charging units can be mitigated by shielding cables and installing filters as required. But that option is clearly not available with wireless charging since electrical power is transmitted through the air as a magnetic field.
According to the RadioWorld posting, the WPT-EV threat is only the latest example of the continuing erosion of AM broadcast quality due to the increased volume of EMI.
Read the RadioWorld posting on the potential risks to AM radio reception from wireless EV charging.
