Three-phase voltage transformer used for 20-kV ring main unit

Abstract

The invention discloses a three-phase voltage transformer used for a 20-kV ring main unit. The three-phase voltage transformer comprises an iron core, a three-phase primary winding and a three-phase secondary winding, wherein the three-phase secondary winding is installed on the iron core, the three-phase primary winding sleeves the three-phase secondary winding, and a main insulation layer cast with epoxy resin is located between the three-phase primary winding and the three-phase secondary winding; the three-phase primary winding is connected with an elbow-shaped cable plug through a primarylead and a fuse separately; the outer surface of an epoxy resin shell is sprayed with the outer surface of a semi-conducting layer; a secondary connection terminal box is fixed to the lower portion of the outer surface of the shell; outgoing lines of the three-phase secondary winding are connected with connection terminals in the secondary connection terminal box respectively. By means of the three-phase voltage transformer, the technical requirements of the state grid for primary fusion and secondary fusion of the ring main unit can be met; especially when the grid complicatedly changes andresonance is strong, various resonance situations can still be effectively restrained, the high precision of measurement is guaranteed, and reliable running of electrical equipment is guaranteed; by adopting the three-phase voltage transformer, the size of the ring main unit can be reduced.

Description

technical field [0001] The transformer of the invention particularly relates to an indoor three-phase voltage transformer. Background technique [0002] my country's power distribution voltage has been raised from the previous 380V to 10KV, and pilot projects have also been carried out in some areas to increase from 10kV to 20kV. With the accumulation of high-rise residential facilities in cities, the formation of centralized power consumption and the grouping and scale of production, it is necessary to send high-voltage power to the load center. If the voltage is increased to 20kV, the line loss can be reduced, the material consumption can be saved, and the economic and social benefits are considerable. However, the ultra-high voltage operation of the grid is unstable, and the national grid, especially the urban grid, has harmonics and unbalanced three-phase loads in operation, which brings difficulties to the measurement and monitoring of the 20KV ring main unit. The vol...

AI Technical Summary

Problems solved by technology

However, the ultra-high voltage operation of the power grid is unstable, and the national power grid, especially the urban power grid, has harmonics and unbalanced three-phase loads in operation, which brings difficulties to the measurement and monitoring of 20KV ring network cabinets

The voltage transformers currently used cannot ideally meet the technical requirements of the State Grid for the primary and secondary integration of the ring network cabinet, and have poor adaptability to the harmonics in the operation of the power grid

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