What is electromagnetic compatibility?

The ability of any other thing to constitute an intolerable electromagnetic nuisance. Electromagnetic compatibility technology is a rapidly developing cross-disciplinary, involving electronics, computers, communications, aerospace, railroad transportation, electric power, military and even all aspects of people's lives. In today's information society, with the development of electronic technology, computer technology, the number of electrical and electronic equipment used in a system has increased greatly, and electronic equipment, the bandwidth of the increasingly wider, the power gradually increased, the sensitivity is improved, connecting a variety of equipment cable network is also becoming more and more complex, so the electromagnetic compatibility problem is becoming more and more important. Power system, in the grid capacity increase, transmission voltage increase at the same time, computer and microprocessor-based relay protection, grid control, communication equipment is widely used. As a result, power system electromagnetic compatibility issues have also become very prominent. For example, substation integrated automation equipment, which integrates relay protection, communication, and SCADA functions, is usually installed in the vicinity of substation high-voltage equipment, and a prerequisite for the normal operation of this equipment is that it is able to withstand the extremely strong electromagnetic interference generated in the substation during normal operation or in the event of an accident. In addition, since modern high-voltage switches are often integrated with electronic control and protection equipment, this combination of strong and weak power equipment needs to be tested not only for high voltage and high current, but also for electromagnetic compatibility.The operation of a GIS disconnect switch can generate fast transient voltages with frequencies up to several megahertz. This fast transient overvoltage will not only jeopardize the insulation of transformers and other equipment, but also propagate outward through the grounding network, interfering with the normal work of substation relay protection and control equipment. With the improvement of the automation level of the power system, the importance of electromagnetic compatibility technology is increasingly apparent. The main content and development trend of electromagnetic compatibility technology The main content of electromagnetic compatibility of power system includes: (1) electromagnetic environment evaluation. That is, the electromagnetic interference level (amplitude, frequency, waveform, etc.) to which the equipment may be subjected during operation is estimated by means of actual measurement or digital simulation. For example, the use of movable electromagnetic compatibility test vehicle on high-voltage transmission lines or substations generated by a variety of interference for actual measurement, or through the electromagnetic transient calculation program on the possible generation of transient electromagnetic field digital simulation. Electromagnetic environment evaluation is an important part of electromagnetic compatibility technology and is the basis of anti-interference design. (2) Electromagnetic interference coupling path. Figure out the electromagnetic interference generated by the source of interference through what path to the object being interfered with. Generally speaking, the interference can be divided into conduction-type interference and radiation-type interference 2 categories. Conducted interference refers to electromagnetic interference through the power line, grounding line and signal line propagation to reach the object of the interference caused by, for example, through the power line incoming lightning impact source interference; radiation interference refers to the electromagnetic source of space propagation to reach the sensitive equipment interference. For example, the transmission line corona generated by radio interference or television interference that belongs to the radiation type of interference. The study of interference coupling pathway, the development of anti-interference measures to eliminate or inhibit interference is of great significance. (3) electromagnetic immunity evaluation. The study of the power system in a variety of sensitive equipment and instruments, such as relay protection, automatic devices, computer systems, power measurement instruments and other electromagnetic interference resistance. Generally, the test is used to simulate the operation of the possible interference and in the equipment as close as possible to the working conditions, test the equipment under test whether it will produce false action or permanent damage. The immunity of the equipment is determined by the working principle of the equipment, electronic circuit arrangement, the working signal level, as well as the anti-interference measures taken. With the power system in a variety of automation systems and communication systems are widely used, with the integration of strong electrical equipment and strong electrical equipment into one tendency, how to evaluate the ability of these devices to withstand interference, the study of practical and effective test methods, the development of evaluation standards will become an important topic of electromagnetic compatibility technology of the power system. (4) anti-interference measures, electromagnetic interference generation and coupling. Sensitive equipment is impossible to completely avoid electromagnetic scratching. Therefore, often more economical and reasonable solution is to apply anti-interference measures on sensitive equipment. For example, lightning strikes on power dispatch buildings are unavoidable. However, the safe operation of the access system and dispatch automation system can be ensured by proper grounding, shielding and isolation measures. Research on effective economic and applicable anti-jamming measures is also an important task in the field of electromagnetic compatibility in the future. (5) Power Quality. International Conference on Large Grids 36 Academic Committee (power system electromagnetic compatibility) to power quality control is also included in the scope of electromagnetic compatibility, the study of frequency variations, harmonics, voltage flicker, voltage dips and other effects on the performance of user equipment. Electromagnetic Field Ecological Impacts Public concerns about the possible harmful effects of industrial frequency electromagnetic fields on human health have become an important constraint on the development of high-voltage power transmission in some countries. The harmful effects of ionizing radiation, such as X-rays and gamma rays, on human health have become familiar. Whether non-ionizing radiation, including low-frequency electromagnetic fields, has harmful effects on biological systems, especially on human health, has always been an open question. Despite extensive research by scientists around the world, it has been difficult to reach a conclusion due to the extreme complexity of the issue. It is predicted that more research is needed in the future.