The emergence of electronic transformers has been hailed as a revolution in the manufacturing of high-voltage electrical appliances in the early 2000s. Its digital output and networked wiring make the power grid safer, more environmentally friendly, and more conducive to the intelligence of the primary equipment and even the entire transmission and distribution system. Compared with traditional transformers, electronic transformers have the following characteristics:
Small signal transmission replaces high power output. Miniaturization and low power of transformers can reduce the weight of tens of kilograms or even tons to a few kilograms. 代替油、气绝缘。 Optically isolated plastic tube float flowmeter replaces oil and gas insulation. Independent high-voltage transformers use optical fiber digital connections once and twice. Optical isolation replaces complex and expensive oil and gas insulation systems. This is a revolutionary change. The higher the voltage, the higher the cost-effectiveness of the transformer. Digital output replaces analog output, which is convenient for subsequent network connection and intelligent processing. It adopts optical fiber transmission and has stronger ability to resist electromagnetic interference. Network data sharing replaces multi-winding parallel wiring. Single-point measurement data of electronic transformers can be transmitted via Industrial Ethernet, so they are shared, and a large number of parallel cables can be omitted at the power station.
Statistics on the application data show that there are currently hundreds of units in China engaged in the tentative research and development of new electronic transformers. There are about ten preliminary supply capacities, and the categories are relatively complete. Currently, there are 3 to 3 5 homes. The products involve different varieties such as 10 ～ 800 kV, current, voltage, free-standing type and combined electrical type. Since 2004, active electronic transformers have entered the market before optical transformers. The high-voltage side of active electronic transformers converts current signals into digital signals and transmits them to ground potential through optical fibers. Like optical sensing solutions, Optical isolation between high and low voltages, coupled with industrial mass production, has become the dominant type of transformer.
During the same period, China developed a more practical "self-excitation source" technology, which has actively transformed into a "quasi-passive" structure. This solution greatly simplifies the transformer and fundamentally improves reliability and life cycle.
和测量精度指标，因而可以替代传统依靠油、气绝缘的互感器。 Soon, a kind of "equal-potential cavity" partial pressure structure suitable for electronic low-power partial pressure appeared in China. It has high insulation safety plastic tube float flow meter and measurement accuracy index, so it can replace the traditional oil and gas Insulated transformer. This technology is particularly suitable for the dry type of high-voltage and ultra-high-voltage voltage divider structures. It is a new type of electronic voltage transformer that has grown out of China. In order to overcome the measurement performance susceptible to temperature and vibration stress, the optical solution has been improved from a ring magneto-optical glass to a fiber-optic sensor, making the optical solution a new technical platform, closer to the practical requirements. A few types of electronic transformers known as fiber optics have been tried out, and they need to further overcome the problems of complex structure and high cost.
The main problems faced by the application Electronic transformers have changed the original assembly application methods. For example, microelectronic devices have been moved forward to high-voltage lines, isolated knife gates, circuit breakers and other strong interference sources in outdoor environments. The test of strong electromagnetic interference rules, so the current major problems in the development and application of electronic transformers are: electromagnetic interference protection, communication error control, reliable power supply methods, and adaptation to outdoor environments. If improper measures are taken, signal failures and protection errors may easily occur. Judgment, aging and so on. To solve these problems, we need to improve the test and inspection standards as soon as possible to promote the focus of the next development of electronic transformers to be highly reliable and stable.
Future research and development direction: Passive sensing: Due to the technical advantages of passive sensing, independent ECT sensing components will tend to be passive. This includes active sensors that will achieve self-power supply by getting rid of dependence on external sources. Going quasi-passive, the average life cycle of electronic transformers will reach more than 10 years. The optical sensor improves the measurement performance, simplifies the system structure, reduces the cost, and becomes practical.
Combined structure: Utilizing the advantages of electronic micropower and miniaturization, the transformers are combined in components as transformers, fully-enclosed plastic tube float flowmeter combination appliances, isolation knives and other combination appliances to reduce land occupation and cost. Through the reuse of functions, the miniaturization and intelligence of the primary electrical appliances themselves are promoted. 各种方案在发挥各自优势的同时，也会相互组合，优势互补，除了会出现各种独立、封闭式电流—电压组合互感器外，今后几年，预计还会出现LPCT/ROG-CT与光学组合版电流互感器。 Various schemes of plastic tube float flowmeters will be combined with each other while taking advantage of their advantages. In addition to various independent and closed current-voltage combination transformers, LPCT / ROG-CT and optical combination version of current transformer.