Are EMF Radiation Levels in Electric Cars Safe?

[Jurgen M]

What is power of EMF radiation inside of electric cars?
What is frequency range, ELF?

 

[f95toli]

Define "inside"? Next to one of the electric motor?
Or where the driver/passengers are sitting?

I guess it depends
The inverter takes user the DC current from the batteries and converts it to a alternating current which then goes to the motors. This is not a "simple" AC current; since -as far as I understand electric cars use pulse-width modulation variable frequency drives; meaning I would assume that the frequencies are in the low ~kHz range

edit: In reality there are -of course- a number of components that will generate EM fields and it not at all obvious that the drive unit itself would be the main source of EMC.
EMC testing of cars is a whole field in itself and there are very stringent rules in place to ensure that the fields do not cause any interference (this is true for all electrical s products

 

[berkeman]

EMC testing of cars is a whole field in itself and there are very stringent rules in place to ensure that the fields do not cause any interference (this is true for all electrical s products

Yeah, I've been at the test lab before when they had a Tesla in an adjacent Anechoic Chamber -- pretty amazing to see.

But all of the EMC testing that I know of is for external to the car, not in the interior. I wonder what kind of standards apply there...?

 

[Jurgen M]

Define "inside"? Next to one of the electric motor?
Or where the driver/passengers are sitting?

I guess it depends
The inverter takes user the DC current from the batteries and converts it to a alternating current which then goes to the motors. This is not a "simple" AC current; since -as far as I understand electric cars use pulse-width modulation variable frequency drives; meaning I would assume that the frequencies are in the low ~kHz range

edit: In reality there are -of course- a number of components that will generate EM fields and it not at all obvious that the drive unit itself would be the main source of EMC.
EMC testing of cars is a whole field in itself and there are very stringent rules in place to ensure that the fields do not cause any interference (this is true for all electrical s products

Yes in cabin, at driver and passengers seats.
Does all electric cars today use AC motors? Why, are they more efficient than DC motors?

 

[tech99]

The EMF exposure will have to comply with the international standard which is ICNIRP. https://www.icnirp.org/
The electric car is evolving towards being an entertainment centre rather than transport - the next toy after the mobile phone - so we are going to see lots of radiation from all the IT equipment.

 

[Klystron]

Increased radar use for guidance and traffic control -- onboard, roadside and above -- should also increase EMR exposure even within legacy and hydrogen fueled vehicles. While reports of highway patrol officers damaged by frequent exposure to radar 'guns' represent extremes; measuring cumulative EMR exposure appears warranted, particularly for professions such as chauffer and truck driver with long exposure.

 

[Windadct]

The vehicles drive ( Battery->Inverter->motor) are very heavily shielded as the EMI requirements for vehicles is pretty high to avoid interference with other critical on board electronics.

I believe most of this type of inquiry are health (fear) related - hyped up by people that either want to sell detectors or some other nonsense. There are many things far more hazarious in your life then the EMI of an EV. Just traveling in a vehicle is one of them.

 

[artis]

Just to add what @Windadct said, the EM radiation strength as for all EM fields drops as one moves away from the source as radius squared. So in order for the field strength to be of worry one would either need to be very close to the field source or have a very strong field.
In this regard I think it's not the drive motor that will give you most EMI instead it will be the "additional gadgets" like radar for assisted cruise control and WiFi etc as we move on to 5G possibly even on the roadside.

Does all electric cars today use AC motors? Why, are they more efficient than DC motors?

Not all AC motors are more efficient than DC and remember some motors are both AC as well as DC like universal motors with brushed commutators.
Specific types of AC motors controlled by semiconductors are indeed more efficient than brushed DC motors but honestly all DC motors that aren't semiconductor controlled like the BLDC are brushed...since you need a way to switch the current otherwise you simply have an electromagnet.

From what I know Tesla now uses a semiconductor switched/controlled synchronous AC motor, which is similar to an induction motor but has permanent magnets in the rotor which is similar to having a field coil in the rotor like synchronous motors/generators have.
The efficiency comes from the motor type and the way it is controlled because with semiconductors you can better control the current that is needed at any particular moment or the back EMF that gets generated and can be used to charge the battery back.