After years of trial practice, the advantages of electronic transformer technology have been verified on some typical power stations. However, while the effect of technological advancement is obvious, the application of expansion is also facing new problems. The most concentrated performance is in dealing with the harsh electromagnetic environment. The underlying reason is that it is not fully aware of the standard system, test method and design specification, both domestically and abroad. The severity of special electromagnetic interference to the power station.
So far, there has not been systematic testing and theoretical research on electromagnetic interference in high-voltage power stations. The result is that the industrial standards for electronic transformers lack test standards and evaluation methods equivalent to the actual operation of power plants. Many manufacturers simply aim at the current standards for research and development, even if they reach the highest level, they can not fully adapt to the field application conditions.
Relevant standards need to be improved
The electronic transformer is an electronic device that runs directly on hundreds of thousands of volts of high-voltage wires. The electromagnetic interference received is much stronger than any other existing electronic devices. We lack research and testing for this unique condition. There are no specific terms in the standard. For example, the IEC and GB/T standards for electronic transformers do not involve the equivalent of the switch arcing operation and the strong current impact test content and evaluation criteria. The existing EMC test is mainly for indoor electronic equipment and cannot be replaced. The physical mechanism and intensity level of electromagnetic interference from power stations. E.g:
First, for space radiation interference, the test standard of GB/T17626.x is the maximum electric field strength of 10 volts/meter, and the maximum frequency of the power frequency magnetic field or pulse magnetic field is 1 kiloamperes per meter. However, when the open isolation knife is operated on the actual power station, the peak value of the electric field generated by the fracture arc is as high as 3 kV/m or more; the high-voltage transmutation transformer installed close to the wire will withstand up to 10 to 100 thousand electronic circuits. The magnetic field impact interference of the amperage/meter scale is about several hundred times higher than the value specified in the GB/T17626.x test standard. The electromagnetic interference intensity greatly exceeds people's habit thinking, and extraordinary measures must be taken. The protection method is obviously a new topic. .
The second is the interference introduced by the signal and power line. The GB/T17626.x standard mainly involves the radio frequency electromagnetic interference received by the wire from the space. The test strength is far less than the real strength on the power station. GIS-type fully enclosed combination electric appliance, the transient potential change of the shell (ground) caused by VFTO (fast transient over-voltage) phenomenon - its interference peak intensity is about 10 ~ 30 kV, the frequency is about 10 ~ 30 MHz The unique interference phenomenon of this high-voltage switch-type electrical appliance is not included in the national standard test content. It is the most important electromagnetic compatibility issue currently faced in the application of electronic transformers. It is this phenomenon that leads to many combinations in primary electrical appliances. The transformer on the fault is frequently transmitted. General interference can cause the transformer to send out distortion data or communication errors, causing the protection device to misjudge or malfunction, and more serious damage to the electronic device, causing the acquisition circuit device to permanently fail.
Successful cases can learn from
In 2011, more than 200 sets of various types of electronic transformers on Yan'an 750 kV intelligent substation were successfully put into operation, and the 750 and 330 sides were subjected to dozens of open-close operation tests, and successfully passed the comprehensive annual inspection. This also proves the fact that electromagnetic interference can be effectively protected even in ultra-high voltage power plants as long as the measures are right. This fact is exactly the opposite of the predictions made by some experts based on the current state of the art in the technical demonstration stage. It also contrasts with the frequent electromagnetic compatibility problems of individual power stations below 220 kV. In fact, the problem lies in the misunderstanding of electromagnetic compatibility. The developers of Yan'an station transformers have realized the seriousness of the electromagnetic compatibility problem. They have adopted the equivalent test method that is higher than the national standard and more harsh than the scene. The 6-month verification test and technical improvements guide the product's electromagnetic compatibility technology and achieve the expected protection effect step by step. The success of the station has broken the imprisonment of the anti-electromagnetic interference technology of the ultra-high voltage station, reflecting the latest achievements of China in this technical field, and has a leading and demonstrating role.
At present, under the leadership of the relevant departments of the State Grid Corporation, new test standards for electronic transformers are being discussed and formulated. The new standards will add some operational tests equivalent to the site to be closer to the actual operating conditions of the power station. This orientation will inevitably become a signpost that leads the scientific, orderly and healthy development of transformer technology. Here, the electric power research institutes are called upon to establish physical and mathematical models of power plant operation disturbances from theoretical and experimental methods as soon as possible, so as to quantitatively describe the mechanism of interference and time and space laws, and develop a reproducible and quantifiable equivalent experimental device. Provide theoretical guidance for establishing the pertinence and effectiveness of protective measures and avoid accidental “trial†tests. In addition, we hope that the new standard will be wide and strict, focus on tightening safety stability indicators, and relax other technical indicators with little relevance to facilitate the integration of modern scientific and technological achievements of various categories into transformer products and maintain China's electronic transformer technology. The good momentum of innovation.
So far, there has not been systematic testing and theoretical research on electromagnetic interference in high-voltage power stations. The result is that the industrial standards for electronic transformers lack test standards and evaluation methods equivalent to the actual operation of power plants. Many manufacturers simply aim at the current standards for research and development, even if they reach the highest level, they can not fully adapt to the field application conditions.
Relevant standards need to be improved
The electronic transformer is an electronic device that runs directly on hundreds of thousands of volts of high-voltage wires. The electromagnetic interference received is much stronger than any other existing electronic devices. We lack research and testing for this unique condition. There are no specific terms in the standard. For example, the IEC and GB/T standards for electronic transformers do not involve the equivalent of the switch arcing operation and the strong current impact test content and evaluation criteria. The existing EMC test is mainly for indoor electronic equipment and cannot be replaced. The physical mechanism and intensity level of electromagnetic interference from power stations. E.g:
First, for space radiation interference, the test standard of GB/T17626.x is the maximum electric field strength of 10 volts/meter, and the maximum frequency of the power frequency magnetic field or pulse magnetic field is 1 kiloamperes per meter. However, when the open isolation knife is operated on the actual power station, the peak value of the electric field generated by the fracture arc is as high as 3 kV/m or more; the high-voltage transmutation transformer installed close to the wire will withstand up to 10 to 100 thousand electronic circuits. The magnetic field impact interference of the amperage/meter scale is about several hundred times higher than the value specified in the GB/T17626.x test standard. The electromagnetic interference intensity greatly exceeds people's habit thinking, and extraordinary measures must be taken. The protection method is obviously a new topic. .
The second is the interference introduced by the signal and power line. The GB/T17626.x standard mainly involves the radio frequency electromagnetic interference received by the wire from the space. The test strength is far less than the real strength on the power station. GIS-type fully enclosed combination electric appliance, the transient potential change of the shell (ground) caused by VFTO (fast transient over-voltage) phenomenon - its interference peak intensity is about 10 ~ 30 kV, the frequency is about 10 ~ 30 MHz The unique interference phenomenon of this high-voltage switch-type electrical appliance is not included in the national standard test content. It is the most important electromagnetic compatibility issue currently faced in the application of electronic transformers. It is this phenomenon that leads to many combinations in primary electrical appliances. The transformer on the fault is frequently transmitted. General interference can cause the transformer to send out distortion data or communication errors, causing the protection device to misjudge or malfunction, and more serious damage to the electronic device, causing the acquisition circuit device to permanently fail.
Successful cases can learn from
In 2011, more than 200 sets of various types of electronic transformers on Yan'an 750 kV intelligent substation were successfully put into operation, and the 750 and 330 sides were subjected to dozens of open-close operation tests, and successfully passed the comprehensive annual inspection. This also proves the fact that electromagnetic interference can be effectively protected even in ultra-high voltage power plants as long as the measures are right. This fact is exactly the opposite of the predictions made by some experts based on the current state of the art in the technical demonstration stage. It also contrasts with the frequent electromagnetic compatibility problems of individual power stations below 220 kV. In fact, the problem lies in the misunderstanding of electromagnetic compatibility. The developers of Yan'an station transformers have realized the seriousness of the electromagnetic compatibility problem. They have adopted the equivalent test method that is higher than the national standard and more harsh than the scene. The 6-month verification test and technical improvements guide the product's electromagnetic compatibility technology and achieve the expected protection effect step by step. The success of the station has broken the imprisonment of the anti-electromagnetic interference technology of the ultra-high voltage station, reflecting the latest achievements of China in this technical field, and has a leading and demonstrating role.
At present, under the leadership of the relevant departments of the State Grid Corporation, new test standards for electronic transformers are being discussed and formulated. The new standards will add some operational tests equivalent to the site to be closer to the actual operating conditions of the power station. This orientation will inevitably become a signpost that leads the scientific, orderly and healthy development of transformer technology. Here, the electric power research institutes are called upon to establish physical and mathematical models of power plant operation disturbances from theoretical and experimental methods as soon as possible, so as to quantitatively describe the mechanism of interference and time and space laws, and develop a reproducible and quantifiable equivalent experimental device. Provide theoretical guidance for establishing the pertinence and effectiveness of protective measures and avoid accidental “trial†tests. In addition, we hope that the new standard will be wide and strict, focus on tightening safety stability indicators, and relax other technical indicators with little relevance to facilitate the integration of modern scientific and technological achievements of various categories into transformer products and maintain China's electronic transformer technology. The good momentum of innovation.
Patch Panel,48 ports patch panel,half U patch panel,patch panel 24 port
NINGBO UONICORE ELECTRONICS CO., LTD , https://www.uonicore.com