EMC of electric vehicles and charging
EMC aspects of electric and plug-in hybrid vehicles: traction inverter emissions, charging-mode requirements in UN R10, off-board chargers, and the relevant standards.
Electric vehicles (EVs) and plug-in hybrids bring new EMC aspects to an old field: very high power electronics, high-voltage battery systems and a connection to the public electricity grid.
Sources of disturbance in an EV
- The traction inverter switches hundreds of amperes at tens of kilohertz with fast edges, creating broadband noise on the high-voltage cables and in the motor cables.
- DC–DC converters and the on-board charger are switching power converters with their own harmonics and common-mode currents.
- The high-voltage battery system and its management electronics must stay immune to disturbance while handling safety-critical functions.
- During charging, the vehicle (or the charging station) is connected to the AC or DC supply and to communication lines, creating conducted paths to the grid.
What the regulation asks for
UN Regulation No. 10 includes requirements for vehicles and ESAs in the “REESS charging mode coupled to the power grid” (the rechargeable energy storage system is being charged from the grid). These requirements, which entered R10 before the 07 series, cover:
- harmonic current emissions and voltage fluctuations and flicker (referring to IEC 61000-3-2, -3-3, -3-11 and -3-12 depending on the current);
- radio-frequency conducted emissions on AC and DC power lines (0.15–30 MHz), referring to the limits of the generic emission standards;
- immunity to fast transients (burst) and surges on the charging lines, as well as the immunity requirements that apply to the vehicle in other modes.
The 07 series (in force since 12 June 2025) separates the conducted-emission limits for residential and non-residential charging environments: vehicles that are charged only in non-residential locations may apply the more permissive limits, with a manufacturer declaration, while the conducted-emission requirement on wired network ports was deleted. For ESAs in the charging mode, the published analyses indicate a restricted choice of test methods. Check the official UNECE text for the exact requirements. See Automotive EMC.
Charging systems
The off-board charging station (the EV supply equipment) is covered by its own EMC standard, IEC 61851-21-2 (EMC requirements for off-board charging systems), and by the generic and product standards for its power and communication ports. The charging modes of IEC 61851-1 (Mode 1 to Mode 4) describe the type of connection, from a simple socket to DC fast charging.
Low-frequency and magnetic fields
Because of the high currents, EVs also create magnetic fields at low frequency. A CISPR publication on electric and hybrid vehicles (CISPR 36) addresses emissions in the lower frequency range to protect off-board receivers; see Automotive EMC.
Design and test points
- High-voltage cables are normally shielded, with careful 360° shield termination at the connectors; the shield is part of the EMC design.
- Artificial networks for high voltage (HV-AN) are used to measure conducted emissions on the high-voltage lines in component tests.
- Filter design for the on-board charger and DC–DC converters follows the general principles in Design for EMC.
- Functional safety links to EMC: the immunity of battery-management, steering and braking electronics must be demonstrated.