This SAE Recommended Practice specifies measurement procedures and performance levels for magnetic and electric field emissions and conducted power mains emissions over the frequency range 150 kHz to 30 MHz, for vehicles incorporating electric propulsion systems, e.g., battery, hybrid, or plug-in hybrid electric vehicles.
Conducted emission measurements in this document are applicable only to battery-charging systems which utilize a switching frequency above 9 kHz, are mounted on the vehicle, and whose power is transferred by metallic conductors. Conducted emission requirements apply only during charging of the batteries from AC power lines.
Conducted and radiated emissions measurements of battery-charging systems that use an induction power coupling device are not covered by this document.
The measurement of electromagnetic disturbances for frequencies from 30 MHz to 1000 MHz is covered in CISPR 12.
This revision of SAE J551 includes numerous technical changes. The conducted limits are re-aligned with current FCC limits, and the radiated emission limits now begin at 150 kHz, corresponding to the CISPR/D decision regarding frequency coverage in CISPR 25. Limit scaling in the near field (Appendix A) now utilizes the 60dB/decade distance relationship due to measurement of both E and H fields, but the vertical H field measurement is deleted due to its typically low magnitude, poor far field radiation efficiency, and lack of receiving systems using this field component. In recognition of the changing nature of electric vehicles (which primarily utilized DC brush motors when the limits were proposed in 1983), the scope has been expanded and ANSI C63.12 limits with average detection are added, while the impulsive bandwidth normalization has been removed from the expression of fields and limits. The emission maximizing procedure has been updated based on experience acquired since the initial procedure was developed.