EV manufacturer Rimac, which is deep into the testing phase in development of its C_Two electric hypercar, has been working with specialist testing service provider SLG in Germany on EMC (electro magnetic compatibility) testing of the vehicle.
The principle behind EMC is the testing of all electrical devices and how they perform in the real world, both in terms of the electromagnetic emissions they give out as well as how they react when receiving inputs from outside influences. This is a crucial development stage, particularly with EVs, and emissions are measured according to an EU-approved standard – ECE R10 – which must be met for the car to be homologated.
Prior to any vehicle level tests, from the early design stages, Rimac implements design methodologies to mitigate interference and conducted testing of all high- and low-voltage systems including the battery, powertrain – inverters, OBC, controllers and communication protocols.
For the current tests, a C_Two prototype is placed inside a semi anechoic EMC chamber, equipped with hybrid absorbers and ground plane, ensuring it is completely sealed off from outside interference. During the tests themselves, the vehicle is driven at various speeds and subjected to radiation levels of between 20MHz and 20GHz.
At specific intervals, electrical systems such as the air conditioning, lights and wipers are also turned on to assess whether the car performs as expected. The tests also take into account each of the car’s specific drive modes, to ensure that the vehicle’s inverters and power distribution react as predicted.
Once the tests have been completed, the specialist teams disassemble the prototype, assess each of the key components individually, and discuss the results to identify any improvement areas. The car is then reassembled, put back into the EMC chamber and the process is conducted once again to ensure that everything is faultless.
Rimac highlighted that EMC is considered ‘black magic’ even by experts in the field, thus physical testing allows its engineers to better understand the overall vehicle behavior and map out the biggest influencing factors.
According to the company, the first test results were better than expected when compared with standardized norms. However, it noted there is still some further refinement work ahead before its own internal targets and quality standards are met. The next steps will include compliance chamber tests at a system level for the powertrain and further loops of improvement investigations on the car before the start of production.