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International Women's Day is just around the corner, and the atmosphere at our company is buzzing with excitement. The 8th of March is a day we eagerly look forward to, as it allows us to celebrate and appreciate the remarkable women who contribute their talents and hard work to our organization. Each and every female member of our team was greeted with a stunning bouquet of flowers, symbolizing the elegance and grace they bring to the workplace. The delicate petals intertwined, creating an enchanting display of femininity and resilience. But the festivities didn't stop there. The aroma of freshly brewed tea filled the air as delicious and refreshing milk teas were presented to the deserving ladies.  The entire workforce radiated joy and camaraderie, united in the celebration of womanhood. Laughter echoed through the corridors, blending harmoniously with the hum of productivity. Happy conversations filled every corner, as colleagues shared stories of empowerment, achievements, and dreams for the future. This momentous occasion served as a gentle reminder of the immense contributions women make in all spheres of life. It showcased the power of unity and recognition, reminding us that true success lies in embracing diversity and empowering one another.

With the continuous development of science and technology and the continuous expansion of human activities, microelectronics technology, computer technology is applied to all aspects of social life, a large number of high technology content, complex internal structure of electrical and electronic products are widely used, so that it is increasingly informatization and electromagnetic sensitivity. The influence of complex electromagnetic environment on human beings has attracted more and more people's attention. Therefore, it is of great significance to study the coupling mechanism of electromagnetism.   I. Concept of electromagnetic environment 　　Electromagnetic environment refers to the sum of electromagnetic phenomena existing in space. A variety of man-made electromagnetic radiation and natural electromagnetic radiation constitute a complex electromagnetic environment, in which man-made electromagnetic radiation, including mobile phones, radio conversational machines, radio and television transmitters, satellites, radar, etc., lightning, static electricity, geomagnetic field, sunspot activity, cosmic rays, etc., constitute a natural source of electromagnetic radiation. 　　The formation of electromagnetic radiation effects requires the simultaneous presence of the following three elements: 　　Electromagnetic wave source, refers to the components, equipment, systems or natural phenomena that generate electromagnetic waves; 　　A coupling channel, meaning a channel or medium that couples or propagates energy from a wave source to a sensitive device and causes that device to respond; 　　Sensitive device, a device that responds to electromagnetic waves. 　　These three elements are usually referred to as the three elements of electromagnetic coupling.   Ⅱ. The coupling mode of electromagnetic radiation 　　(A) antenna coupling 　　All exposed to the electromagnetic field of the metal conductor can be considered as an antenna, "front door" coupling ("front-door" coupling) means that the electromagnetic pulse or microwave energy through the target on the antenna coupled to the electronic system. Therefore, according to the design characteristics of the antenna to calculate the coupling strength, when the electromagnetic wave frequency and antenna design frequency is equal, the coupling reaches the peak. 　　(B) hole and seam coupling 　　Generally, electronic equipment is encapsulated in a container composed of conducting material. Due to equipment cooling and ventilation, notches, cracks, and feed, signal transmission needs, the container can not be sealed, there are different types of holes and seams, which provides a coupling pathway for electromagnetic radiation. "Back-door" coupling ("back-door" coupling) is a high-energy electromagnetic pulse energy through the target on the hole, gap coupling into the system, interference or destruction of electronic equipment. When the wavelength is smaller than the size of the holes, electromagnetic waves will enter the shielding body without obstruction; when the wavelength is larger than the size of the holes, electromagnetic waves will be blocked; when there is the size and length of the electromagnetic wave comparable to the holes, electromagnetic wave coupling is very serious, will produce resonance. 　　(C) power line, transmission line coupling 　　Power line is exposed to the system outside the long line, vulnerable to electromagnetic energy attack, both to receive interference energy can also transmit interference energy. If there is a power line or signal transmission line from the shielding shell connected to the inside of the system, the received, induced current will propagate along the line into the shielding body. The general propagation is microwave pulse current, even if the current is not introduced from the lead of the transmission cable core, but is induced on the outer shield, through the transfer impedance will also be coupled to the core, directly into the electronic system. For microwave, shielded cable transfer impedance is also much larger than the RF, so microwave can be through the power line, the braided shield of the transmission line into the core. 　　(D) the skin effect of metal shells 　　Electromagnetic wave penetration of the metal shell is realized through the skin effect, electromagnetic waves in the material skinning depth as follows 　　Where f is the frequency of the electromagnetic wave, and respectively for the magnetic permeability and electrical conductivity of the metal shell material. For 2GHz microwave signals, it is in the copper (=5.5 × 107S/m) and aluminum (=3.2 × 107S/m) in the skinning depth of 1.52 and 2.82. For higher frequency microwave signals, the value of the skinning depth is smaller.   Ⅲ. the role of electromagnetic energy mechanism 　　Electromagnetic hazards on the impact of high-tech equipment, mainly through the energy of conduction coupling, radiation coupling occurs, the role of the mechanism can be summarized as follows four aspects: 　　(A) thermal effect 　　Electrostatic discharge and high-power electromagnetic pulse generated by the thermal effect is generally completed in nanoseconds or microseconds, is an adiabatic process. As an ignition source and detonation source, instantly cause flammable, explosive gas or electrical fireworks explosion, but also can make the system of microelectronic devices, electromagnetic sensitive circuits overheating, resulting in localized thermal damage, circuit performance deterioration or failure, and even lead to the stockpile of material combustion and explosion. 　　(B) radio frequency interference and "surge" effect 　　Electromagnetic radiation caused by radio frequency interference, information technology equipment caused by electrical noise, electromagnetic interference, so that it produces false action or functional failure. Strong electromagnetic pulse and its "surge" effect on the system will also cause hard damage, not only can make the device or the performance parameters of the circuit deterioration or failure, but also the formation of cumulative effects, buried potential hazards, so that the circuit or the use of equipment to reduce. 　　(C) strong electric field effect 　　Electromagnetic hazards generated by the strong electric field (especially static field) can not only make the MOS circuit gate oxide layer breakdown or intermetallic dielectric breakdown, resulting in circuit failure, but also the formation of potential damage to the system self-testing instrumentation and sensitive devices affect the work. 　　(D) magnetic effect 　　Electrostatic discharge, lightning strikes, lightning and similar electromagnetic pulse caused by strong currents can produce a strong magnetic field, so that the electromagnetic energy is directly coupled to the internal system, interfering with the normal operation of electronic equipment.   　　References: 　　[1] Liu Shanghe, Wu Zhancheng:Electromagnetic environment and high-tech weaponry[J]. Modern Military,2001. 　　[2] Wu Xiong:Environmental Problems of Electric, Magnetic and Electromagnetic Fields[J]. Electric Power Environmental Protection,2007,(4). 　　[3] Gao Yan and Yu Bo: Characteristics of Complex Electromagnetic Environment[J]. Sichuan Journal of Military Engineering,2008,(1). 　　[4] Gao Bin, Tang Xiaobin: Complex Electromagnetic Environment Effects[J]. Journal of China Academy of Electronic Science,2008,(4).

Current transformer has the role of current conversion and electrical isolation, is the power system measuring instruments, relay protection and other secondary equipment to obtain electrical primary circuit current information sensor. The structure of the current transformer, by the mutual insulation of the primary winding, secondary winding, iron core and frame, shell, terminals and other components. Its working principle is basically the same as the transformer, the primary winding turns N1 less, directly connected in series with the power line, the primary load current through the primary winding, the alternating magnetic flux induction generated by the proportionally reduced secondary current; the secondary winding turns N2 more, and instruments, relays, and other current coils of the secondary load in series to form a closed loop. energy harvesting current transformer self-powered current transformer split core current transformer Positive oil-immersed current transformer  　　At present, the domestic current transformer is mainly oil-immersed orthostatic, is a traditional form of our country, the primary line for the traditional U-shaped structure, its main insulation for the transformer oil and cable paper insulation structure, the main insulation is mainly made of cable paper wrapped and become, in order to make the internal electric field is more uniform, the insulation layer has a main screen and the end of the internal screen. As the current transformer is a U-shaped structure, the outer insulation casing is generally tower-shaped structure. 　　Advantage is that you can use insulation banding machine for insulation banding, banding equipment is generally relatively simple, low price. 　　The disadvantage is that the product is bulky, tower casing internal cavity is relatively large, the amount of oil is relatively large.    Inverted SF6 gas-insulated current transformer  　　Through the introduction of technology in China appeared inverted SF6 gas-insulated current transformer, the structure of the product using inverted structure, the secondary coil through the metal shielding package, placed in the upper part of the product, due to the coil is relatively heavy, generally need to pot insulator or insulated strut support, the secondary coil through the introduction of its internal a metal tube into the low-voltage side of the primary wire is generally a straight line of copper or aluminum tubes, all the cavities filled with SF6 gas. 　　The advantage is that the resistance to dynamic thermally stabilized current is strong. 　　The disadvantage is that its electric field distribution is very uneven, especially in the upper flange of the casing electric field is more concentrated, some products are equipped with shielding electrodes, the volume is larger, at the same time, because of its internal SF6 gas-filled, if the gas leakage, or impact on the atmospheric protective layer, is not conducive to environmental protection.    Inverted oil-immersed current transformer  　　Through the introduction of technology domestic production of inverted oil-immersed current transformer, the product for the oil-immersed cable-paper insulated current transformer, the secondary coil wrapped through the metal shielding, placed in the upper part of the product, the secondary coil of its internal a metal pipe into the low-voltage side of the secondary coil and the lead outside the metal pipe is not wrapped in cable paper and crumpled paper insulation, the primary wire is generally a straight line of copper or aluminum tubes. 　　Advantages are small size, light weight, beautiful appearance and resistance to dynamic heat stabilization of current capacity. 　　The disadvantage is that the coil part and the lead pipe part of the insulation package can not be completed at once, the coil part of the insulation package needs to be completed manually, and need to be insulated with the lead pipe part of the docking, insulation package time-consuming and laborious, long processing cycle.    Dry type current transformer  　　Dry current transformer is a new product, the primary line using U-shaped copper or aluminum wires, insulation for the polyester film banding, banding process between the polyester film gap filled with silicone grease to improve insulation properties, in the insulation layer outside the bonding of the silicone rubber umbrella, the formation of the current transformer's external insulation; secondary coils were set on both sides, and closed with a metal shell. The product due to the insulation layer filled with semi-liquid medium, there will be no oil leakage phenomenon.    Electronic Current Transformer  　　With the rapid development of optoelectronics technology, many developed countries have turned their attention to the use of optical sensing technology and electronics to develop a new type of electronic current transformer, referred to as photoelectric current transformer. Electronic current transformer refers to the output of small voltage analog signal or digital signal current transformer, its meaning in addition to include photoelectric current transformer, but also includes a variety of other current sensors using electronic testing principles. Electronic current transformer is divided into active and passive two categories. 　　The advantages of electronic current transformer is, no iron core, insulation structure is simple, small size, small quality, good linearity, good resistance to electromagnetic interference, no magnetic saturation phenomenon, high measurement accuracy, the output signal can be directly into the microcomputerized measurement and protection equipment interface. 　　Disadvantage is that the sensing head is more sensitive to temperature and vibration, in order to improve accuracy and stability, electronic signal processing part of the line will be more complex, and for active electronic current transformer, must protect the stability of the power supply.

Hemei Electronics is honored to participate in Power Asia 2021, which is themed "Smart Energy, Green Grid" and aims to focus on innovation and development in the fields of electric power, smart grid, energy, construction, rail transportation, wire and cable. As an experienced and visionary company, Hemei Electronics has always been committed to promoting the maturity and transformation of the power industry. We understand the growing demand for green, sustainable energy worldwide, and we are committed to providing our customers with innovative solutions to meet the ever-changing needs of the industry. At this Power Asia, we will showcase our unique smart power products and solutions, which include source-less power supply units, CT pickup power modules, ultra-high precision AC measurement sensors, pomo alloy cores, magnetic shielding boxes, and more. These products not only enable effective dispatch and supply of power, but also minimize energy loss and improve energy efficiency. Whether you are an exhibition visitor, industry expert or partner, we sincerely invite you to visit our booth and learn about our innovative products and solutions. We look forward to exploring the future of the power industry with you and laying the cornerstone for a better tomorrow! In building and rail transportation, Hemei Electronics will showcase our innovative electrical products and systems to improve energy efficiency and safety in buildings and transportation facilities. Our rugged wire and cable products offer good insulation and reliable current transmission capabilities to meet the demands of a wide range of demanding environments. We are confident that our participation in Power Genius Asia will bring more business opportunities and partnerships to Hemei Electronics. We are looking forward to in-depth exchanges and cooperation with professionals from all walks of life to jointly promote the development of smart energy and green power grids, and to contribute to the sustainable development of the world.

On the 24th September 2022, the inauguration ceremony of the new headquarters of Hemei Electronics came to a perfect end, leaving a colourful mark in the long river of history. All employees gathered together to witness this important moment. Under the ethereal golden light, the stylish and modern architectural style of the new headquarter highlights Hemei's firm commitment to innovation and progress. It kicked off with a powerful welcome speech from the honourable General Manager, who pulled off the salute with a resolute and dignified expression that embodied the spirit of joy. His words contained a firm belief in the unlimited potential of the future of Hemei Electronics. Every syllable contained ambition and the promise of a better tomorrow.