Prospect of electromagnetic compatibility of radio energy transmission system

In the past decade, scholars at home and abroad have made a lot of progress in the field of electromagnetic compatibility of radio power transmission system, but there is still room for progress. The author looks forward to the future from the aspects of mechanism analysis, medium influence, electromagnetic compatibility of free radio energy transmission technology system and dynamic WPT system. In the practical application process, the WPT system will deviate from the original expected working state due to environmental factors, load changes, coil offset or coil over coupling and other factors. < p > < p > take the coil offset as an example, when the magnetic coupling coil has a lateral offset, it will cause serious electromagnetic distortion, which will make the electromagnetic interference in some positions significantly enhanced. The change of self inductance coefficient caused by environmental factors will also make WPT system deviate from the original resonance state, which makes the distribution of electromagnetic field different from the resonance state. < p > < p > in addition, the electromagnetic environment of induction type and resonant type WPT system also has different electromagnetic mechanism [65]. The action mechanism of electromagnetic field in near-field and far-field region also needs further theoretical research. The impact of environmental media is one of the problems that must be considered in the practical application of WPT technology. At present, most scholars focus on the research of metal media and water medium, among which metal media has rich theoretical results, but the relevant literature on water medium, especially in seawater environment, is relatively rare. < p > < p > due to eddy current loss, shielding refraction and other phenomena in seawater environment, the corresponding electromagnetic field analysis is more complex than metal medium and fresh water medium; at the same time, the disturbance, salt content and temperature of seawater will further degrade the electromagnetic field distribution of WPT system, making the electromagnetic radiation phenomenon more serious. Exploring the influence mechanism of environmental media can promote the application of WPT to better adapt to the changing environmental factors. < / P > < p > at this stage, commercial WPT products mainly use one-to-one charging, and are often required to fully align the charging equipment with the transmitting coil. In the future, WPT technology may be developed to realize ubiquitous Contactless charging, that is, u-ipt can realize the charging service without plug-in line in a three-dimensional space, no matter how the battery position and direction changes. < / P > < p > in order to meet the safety limit of electromagnetic radiation, the u-ipt system should have a uniform magnetic field distribution in a large area, and achieve effective EMI suppression through electromagnetic shielding. < / P > < p > some scholars have explored the electromagnetic radiation suppression effect of conductive electromagnetic shielding on u-ipt system. The aluminum plate shield is placed on the side of the coil conductor which is close to the coil conductor to generate the unexpected magnetic flux. This scheme can effectively offset the unexpected magnetic field distribution and enhance the magnetic flux density in the expected region of the u-ipt system. The experiment has been carried out in a u-ipt system with nine power receiving loads verification. At present, there are few researches on electromagnetic compatibility of u-ipt system, which may become a research direction for future researchers. < / P > < p > dynamic wireless charging technology is an extension of static wireless charging technology, which can provide continuous charging service during the driving process of electric vehicles. Compared with the static WPT system, the dynamic WPT system needs to face the problem of fast changing coupling coefficient between coils, which means that the electromagnetic environment of dynamic WPT system is constantly changing, which brings certain challenges to the EMC Research of WPT system. At present, KAIST has successfully applied this technology to olev and realized commercial operation. Meanwhile, in order to make the electromagnetic radiation of WPT system meet the limit requirements of ICNIRP guidelines, KAIST proposed a series of electromagnetic interference suppression measures for WPT system of olev, effectively limiting the electromagnetic radiation of WPT system in the range of not endangering human safety. In order to make the dynamic WPT system more commercialized, its electromagnetic compatibility research will become the research focus of future scholars. < p > < p > this paper is compiled from, the original title is “research status and development trend of electromagnetic compatibility of radio energy transmission system”, and the authors are Shen Dong, Du Guiping, Qiu Dongyuan and Zhang Bo. Continue ReadingIqoo5 series debut strength interpretation of “120 super full mark flagship”

Author: zmhuaxia