Transformer development history
The transformers first appeared at the end of the 19th century. With the development of the power industry, the voltage of the transformer, etc.
The transformer level and accuracy level have been greatly improved, and many special transformers have been developed, such as voltage and current composite transformers, DC current transformers, high-accuracy current ratiors and voltage ratiors, and high-current lasers. Current transformers, electronic circuit compensation transformers, photoelectric transformers in ultra-high voltage systems, and voltage and current transformers in SF6 fully enclosed combined electrical appliances (GIS). In the power industry, to develop power systems of any voltage class and scale, it is necessary to develop transformers with corresponding voltage levels and accuracy to meet the needs of power supply system measurement, protection and control.
With the continuous application of many new materials, many new types of transformers have emerged, and electromagnetic transformers have been fully developed. Among them, the core-type current transformers are dry, oil-immersed and gas-insulated. Adapted to the development needs of power construction. However, with the continuous increase of power transmission capacity, the continuous improvement of the voltage level of the power grid and the continuous improvement of the protection requirements, the general core-type current transformer structure has gradually exposed the weak points that are incompatible with it, and its inherent large volume and magnetic Saturated, ferromagnetic resonance, small dynamic range, narrow band of use and other weaknesses, it is difficult to meet the development needs of the new generation of power system automation, power digital network and so on.
With the rapid development of optoelectronic technology, many developed countries have turned their attention to the use of optical sensing technology and electronic methods to develop new types of electronic current transformers, referred to as photoelectric current transformers. The International Electrotechnical Commission has published standards for electronic current transformers. The meaning of electronic transformers, in addition to including photoelectric transformers, includes various other voltage and current sensors that utilize the principles of electronic testing.
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