Low and high voltage complete electrical equipment refers to the combination of electrical components including circuit breakers, isolating switches, load switches, fuses, voltage transformers, current transformers, and lightning arresters, configured reasonably and enclosed in a metal shell to form a unified electrical equipment system, while possessing relatively complete functions. Complete electrical equipment includes: box-type substations (miniaturized box transformers), ring network cabinets (fully insulated gas-insulated cabinets), gas-insulated metal-enclosed switchgear (GIS), metal-enclosed switchgear (switch cabinets), and integrated control cabinets, all of which have been put into practical operation in the power industry.
Compared to traditional primary equipment, low and high voltage complete electrical equipment has advantages such as high reliability, low failure rate, and stable operation. At the same time, complete electrical equipment is relatively compact, durable, and has a high safety factor, allowing for modularization of electrical equipment. In the actual operation of electrical equipment, it facilitates maintenance personnel in operating and maintaining the equipment, thus becoming increasingly favored and developing rapidly.
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The current status of low and high voltage complete electrical equipment
Currently, low and high voltage complete electrical equipment has developed to a certain extent and has been widely applied in the power industry, playing an important role in ensuring safe and reliable power supply. In the context of rapid economic development in our country, the electrical equipment industry has also seen significant improvements. Through the "introduction-digestion-absorption-innovation" of advanced foreign technologies, the electrical equipment industry has developed rapidly, and market demand continues to increase.
The low and high voltage complete electrical equipment that has been practically applied in engineering has adopted a series of advanced technologies. In terms of high voltage electrical appliances, SF6 technology, vacuum technology, and combination technology have been widely applied in power circuit breakers, basically achieving the goal of not using oil as an arc extinguishing medium, thus realizing oil-free operation. Currently, domestic electrical equipment at voltage levels of 500kV and below can meet domestic development needs, and its technical parameters are close to or have reached advanced foreign levels.
The low voltage electrical equipment industry has taken the lead in applying computer technology to product structures, achieving product intelligence and networking, and has already seen the emergence of intelligent low voltage circuit breakers, motor controllers, overload relays, and a series of switch cabinets. In addition, low voltage electrical equipment has made gratifying achievements in reliability research, contactless switches, vacuum technology, current limiting technology, zero arc, high performance and miniaturization, modularity, and standardization.
China's high voltage switches have developed to metal-enclosed types (including armored, compartment, and box types), while low voltage equipment mainly consists of enclosed withdrawable units. Various high voltage truck-mounted, ring network cabinets, box transformers, as well as low voltage drawer cabinets and motor control centers have been widely applied in engineering.
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Development trends of low and high voltage complete electrical equipment
Complete electrical equipment is small in size, occupies less space, and has high performance, while the reliability of equipment operation is also high, and the inspection cycle of equipment can be shortened. With the rapid increase in modern electricity consumption, the demand for reliability in electricity use is also continuously rising, and the application of low and high voltage complete electrical equipment will become increasingly widespread.
At the same time, with the acceleration of smart grid construction, future power systems will not only need to achieve optimized control at the control level but also need to realize intelligence in primary electrical equipment to ensure highly reliable power supply. To achieve intelligence in low and high voltage complete electrical equipment, advanced automatic control technology must be adopted for the operation of electrical equipment.
Intelligent complete electrical equipment centralizes the protection, control, monitoring, and measurement of the entire power distribution system, achieving automation of the distribution network and laying a certain foundation for wide-area detection and diagnostic systems in the power system, ensuring the safe operation of the power system. The high voltage electrical specialty must not only adapt to the trend of integrated development across various specialties, breaking down professional barriers, but also penetrate and integrate with electronic technology, computers, and secondary systems to better realize the intelligence of electrical equipment.
At the same time, future low and high voltage complete electrical equipment should achieve informatization, with the capability for remote information reception and transmission, allowing real-time monitoring of the operational status of complete electrical equipment at the centralized control center. Moreover, advanced technologies such as CAD, CAPP, CAM, CAE, and MIS will be increasingly applied in the field of electrical equipment.
In addition, the reliability of low and high voltage complete electrical equipment will continue to improve. Currently, low and high voltage complete electrical equipment needs to be equipped with UPS power supplies due to existing power quality issues in the grid, such as power outages, lightning strikes, surges, frequency oscillations, voltage fluctuations, frequency drift, voltage drops, and pulse interference. Therefore, from the perspective of improving power quality, equipping low and high voltage complete electrical equipment with a UPS power supply is essential. Additionally, to achieve informatization of low and high voltage complete electrical equipment, precise network and communication devices must be used, which cannot tolerate power interruptions, making UPS power supplies increasingly significant in future low and high voltage complete electrical equipment.
Currently, both domestically and internationally, the scientific theory of electrical equipment is not yet fully developed, and there are still many areas that need improvement and enhancement, especially in the establishment of mathematical models for the arc process and other aspects that require further research. The heat generation, electrodynamics, electrical contact, and electromagnetic characteristics of electrical products also need in-depth analysis and research.
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Conclusion
Low and high voltage complete electrical equipment has the advantages of stable operation and high reliability, and its application fields in the power industry are continuously expanding. In the future, low and high voltage complete electrical equipment will continue to develop towards intelligence, informatization, and automation, playing an increasingly important role in ensuring the safe production and reliable supply of electricity.