Since the beginning of this year, many cities, including Beijing, Shanghai, Guangzhou, Shenzhen, and Hangzhou, have introduced measures to promote automobile consumption and boost car sales. On July 31 , the Beijing Municipal Commission of Transport announced that Beijing will issue 20,000 additional new energy passenger vehicle license plates to "carless families" starting August 1 .
Once upon a time, it was rare to see cars with gradient green or yellow-green license plates on the road, and if you did see one, you would wonder, "Does such a license plate exist?" Now, they are everywhere, and people have become accustomed to and look forward to owning a "cool" new energy vehicle.
New energy vehicles, also known as "alternative fuel vehicles" or "low-emission vehicles," replace petroleum and internal combustion engines with electricity and power batteries (including fuel cells), ushering humanity into a clean energy era and becoming the future direction of automobile development under the dual pressures of energy and environmental protection.
The high electrification rate of new energy vehicles makes them more susceptible to electromagnetic interference (EMI) problems compared to conventional vehicles, becoming a significant factor restricting their development. Therefore, research, testing, and improvement of the EMI performance of new energy vehicles are crucial and will have a profound impact on the development of the new energy vehicle industry.
NO.1 What are new energy vehicles?
In layman's terms, vehicles with gradient green or yellow-green dual-color license plates are considered new energy vehicles. Theoretically, they refer to automobiles that use unconventional vehicle fuels as their power source (or use conventional vehicle fuels with new onboard power devices), integrating advanced technologies in vehicle power control and drive systems to create vehicles with advanced technical principles, new technologies, and new structures.
New energy vehicles include four main types: hybrid electric vehicles (HEVs) , battery electric vehicles (BEVs , including solar-powered vehicles ) , fuel cell electric vehicles (FCEVs) , and other new energy vehicles (such as those using supercapacitors, flywheels, and other high-efficiency energy storage devices). Unconventional vehicle fuels refer to fuels other than gasoline, diesel, natural gas (NG) , liquefied petroleum gas (LPG) , ethanol gasoline (EG) , methanol, and dimethyl ether.
NO.2 What is electromagnetic compatibility?
Electromagnetic compatibility ( EMC ) refers to the ability of a device or system to operate within its electromagnetic environment without generating unacceptable electromagnetic interference ( EMI ) to any other device in that environment. EMC includes two aspects: firstly, the EMI generated by the device during normal operation must not exceed certain limits; secondly, the device must have a certain degree of immunity to EMI present in its environment, i.e., electromagnetic susceptibility ( EMS ).
Electromagnetic compatibility measurement is imperative
With the increasing number of intelligent and entertainment devices in vehicles, their high frequency, high speed, high sensitivity, multi - functionality, and miniaturization significantly increase the probability of EMI generation and impact, making the EMC environment of electric vehicles more complex. Failure to pass electromagnetic compatibility (EMC) testing will not only significantly affect the internal systems but also impact vehicle performance during operation, potentially causing adverse effects on user safety and the environment. EMC issues increase consumer concerns and reduce their enthusiasm for purchasing new energy vehicles. It is no exaggeration to say that EMC has become a crucial indicator for evaluating the performance of new energy vehicles; poor EMC can seriously affect their safety and reliability. Improving the EMC performance of new energy vehicles will be a vital step in promoting the further development of the new energy vehicle industry.
Electromagnetic interference (EMI) is a serious problem in new energy vehicles. It's not just the electric drive equipment and DC/DC or DC/AC components that cause EMI; the systems within the vehicle itself also contribute, such as the high-voltage integrated system, which connects components prone to radiating interference. Furthermore, the electronic controllers and battery management systems of new energy vehicles also generate significant radiated interference.
