A while ago, the country released a series of national standards on "wireless charging of electric vehicles".
The National Standardization Administration Committee released in the announcement: "Electric Vehicle Wireless Charging System Part 1: General Requirements" (GB/T 38775.1), "Electric Vehicle Wireless Charging System Part 2: On-board Charger and Communication Protocol between Charging Equipment" (GB/T 38775.2), "Electric Vehicle Wireless Charging System Part 3: Special Requirements" (GB/T 38775.3), "Electric Vehicle Wireless Charging System Part 4: Electromagnetic Environment Limits and Test Methods" (GB/T 38775.4) ***4 national standards.
This standard system plans 18 standards, standardizing the technical requirements, performance requirements, functional requirements, safety requirements, communication protocols, test requirements and experiments of electric vehicle wireless charging systems in public and private applications. Methods, interoperability requirements and testing methods, construction acceptance, operation and maintenance, etc. Four national standards have been released this time, and four more national standards are in the process of being compiled.
Wireless charging is nothing new in this day and age.
Especially for those of you who are using mobile phones, you may have just picked up your mobile phone from the wireless charging pad. However, for electric vehicles, wireless charging technology has always been in the stage of "only hearing the sound, not seeing the person". Although many car companies have demonstrated wireless charging functions in real vehicles in recent years, they have not been able to measure them in quantity. It is installed on production cars, let alone popularized.
In theory, wireless charging technology for electric vehicles can not only greatly improve the user’s car experience, but also pave the way for the final step of unmanned autonomous driving scenarios in the future. One of the important reasons why it has not really entered the market is that various countries failed to formulate unified standards for this technology as early as possible, which resulted in a series of "chain reactions" and made it difficult to scale up and market the technology. Only after relevant standards are determined can the industry develop truly rapidly.
What is quite interesting is that in the national standard released this time, in addition to being led by the China Electricity Council and the China Electricity Council, as well as the participation of two government departments, the Institute of Electric Power Research and the China Automotive Research Institute, there are also The only foreign company involved in the formulation of the national standard is WiTricity. In fact, WiTricity has also participated in the formulation of wireless charging standards for electric vehicles in the two major markets of North America (SAE J2954) and Europe (ISO 19363, IEC 61980).
What is the origin of this company? This has to start with the wireless charging technology itself.
Wireless charging originated from Michael Faraday’s electromagnetic induction and was invented by Nicholas Tesla. It was not really put into use until the past 10 years. Currently, there are three main methods: electromagnetic induction, electromagnetic vibration, and radio wave. However, the radio wave type converts electromagnetic waves into electrical energy, so the balance between power and safety is a tricky issue, and it is currently rarely used. Let’s not mention it here for now.
(Nicholas Tesla’s vision of global wireless charging)
Electromagnetic induction, a simple understanding is the principle of a transformer, which transmits electrical energy to the primary coil, causing the secondary coil to couple Induction creates an electric current, allowing energy to be transferred "wirelessly" from one end to the other.
(Principle diagram of mobile phone wireless charger, picture/Real Engineering)
The principle and hardware requirements of this method are relatively simple, and relevant standards were formulated earlier, such as the well-known Qi wireless Charging standards are formulated by WPC (Wireless Power Consortium, Wireless Charging Alliance). Therefore, this type of charging technology has achieved large-scale production, has low production costs, has been tested by the market, and is relatively popular.
The disadvantage is that due to the limitations of the technical principle itself, the transmission distance is too short. As the distance increases, the loss of wireless charging will increase and the efficiency will decrease. So this is also the reason why when the mobile phone is a little further away from the wireless charging pad, it cannot be charged.
The electromagnetic vibration type, simply understood, is the "upgraded version" of the electromagnetic induction type. Essentially, it uses electromagnetic vibration technology to improve the transmission efficiency of electromagnetic induction under loose coupling. , thereby achieving a longer transmission distance while ensuring efficiency (charging distance and charging area are more than 10 times higher than electromagnetic induction methods).
(Electromagnetic vibration wireless charging technology demonstrated by MIT professor Marin Solja?i? team in 2007)
In 2007, MIT professor Marin Solja?i? team wrote a paper and It demonstrated electromagnetic vibration wireless charging technology, using two 5-turn copper coils as two ends, lighting a 60W power bulb at a distance of two meters, with an efficiency of about 45%. The research team then adopted the name of the project, established a private company, WiTricity, and applied for relevant patents on this technology.
Compared with the electromagnetic induction type, the characteristics of the electromagnetic vibration type are obviously more in line with the needs of wireless charging of electric vehicles. Therefore, not long after the technology demonstration was announced, WiTricity received offers from Audi, BMW, Chrysler, Jaguar, Nissan and Toyota, all of whom expressed their willingness to cooperate with it.
However, after receiving financial support, the development of wireless charging technology for electric vehicles did not go as well as expected. There are only a few models that have actually been implemented, such as the 530e iPerformance displayed by BMW in 2018, which can wirelessly transmit power with a power of 3.2kW.
During this period, competing Qualcomm acquired Halo wireless charging company and also vigorously developed electromagnetic vibration wireless charging technology. It also announced that it would install wireless charging technology on mobile phones in 2018. On the Mercedes-Benz S550e model. However, after years of development, Qualcomm may have considered the consumer electronics market to be more important, so it sold its electric vehicle wireless charging division and all technology patents to WiTricity in 2019.
Since then, WiTricity has acquired a large number of patents for wireless charging of electric vehicles, and has used this advantage to begin to promote the formulation of relevant standards in various regions.
In fact, there are many companies focusing on wireless charging technology for electric vehicles, but in the end they either fell into the experimental stage, or after market research and research, they found that this technology seemed to have no future, and finally gave up and switched to Heading towards wireless charging technology in the field of consumer electronics. Most of the major car companies that entered the market early retained a tepid attitude in the end.
(WattUp’s electromagnetic vibration multi-device simultaneous charging technology demonstrated by WattUp can charge devices within a certain range without the need to be in contact with the charging source)
Wireless charging, On the surface, it seems to only solve the "laziness" problem, eliminating the process of picking up the charging gun and inserting it into the charging port; but in fact, wireless charging solves more than this problem. Charging specifications and interfaces can be completely unified through wireless charging. , compared with wired charging layout, it saves space, can solve many charging pile safety issues, and can provide completely unmanned operation for autonomous driving travel business.
(Charging robot tested by Tesla)
Of course, from a power point of view, the maximum wireless charging capacity of the sample product is only 22kW, which is indeed slower than overcharging, which can easily exceed 100kW. A lot; but this does not hinder the practical convenience in many scenarios, such as when the vehicle is placed in the parking lot or when it is parked in the garage at home. The insensitivity brought by wireless charging can truly allow the vehicle to charge "all the time" without any interruption. Worried about being "replenished".
But then again, so many "pioneers" eventually gave up one by one. It's not that they don't know these advantages, but it's not that easy to achieve all of this relatively perfectly.
In addition to the lack of charging speed advantages, the safety issues of wireless charging of electric vehicles have always been one of the important reasons hindering market acceptance. Although from the perspective of scientific demonstration, the wavelength of the 6.78MHz frequency band used in electromagnetic vibration technology is approximately 30 meters and is harmless to the human body, the demonstration of these issues still requires a lot of experiments and time.
Not only that, the previous lack of standard setting has prevented the entire industry from reaching scale, resulting in the cost of hardware equipment being much more expensive than wired charging. In this way, both individual users and public companies cannot use it. The construction of facilities is not cost-effective, so it will be difficult to promote it. In fact, even if China now formulates relevant standards, it will take a long time to gradually improve the entire industry, thereby gradually reducing costs and truly being accepted by the market.
In other words, for the wireless charging technology of electric vehicles, the current situation is very similar to Tesla’s just starting stage. The immaturity of related industries will definitely mean difficulties in the early stage. Coincidentally, the "bumpy" experiences of wireless charging technology and electric vehicles are very similar. They are both centuries-old things and are not new technologies. However, due to the influence of various environmental factors, real development has been delayed; however, once these technologies are assisted, they will quickly release energy and reveal strong development potential.
From quantitative changes to qualitative changes, the "spring" of electric vehicle charging technology may really be coming.