CN2073615U - Duplex shielded mutual inducer - Google Patents

Abstract

The utility model relates to a duplex shielded mutual inducer, and at least one layer of shielded coil 4 is wound on the outer layer of an iron core 5 or a secondary winding 3 of the existing mutual inducer. One half of each layer coil is wound leftward, and the other one half is wound rightward. Besides, the housing of the mutual inducer is provided with a metallic shielded housing. Therefore, the utility model has the advantages of simple structure, high reliability, and favorable shielded effect.

Description

Duplex shielded mutual inducer

The utility model relates to a kind of instrument transformer, is a kind of instrument transformer that has dual shield.

Along with the development of China's electric utility, single-machine capacity is that the generating set of 300MW and 600MW is set up in succession.Because the loop current of this heavy-duty generator group is big, and whenever nearer separately, therefore can produce very strong electromagnetic field, this is that magnetic field is not fallen as if shielding, not only to the instrument transformer serious interference, and affects measurement effect.

In order to solve the strong-electromagnetic field interference problem of big electric current major loop, abroad some manufacturer has begun in the outer safeguard measure that adopts of current transformer, and for example the Westinghouse Electric of the U.S. is exactly that skin at instrument transformer has increased a metallic shield shell.But because this screening can not only requires it to have higher metal purity and conductance, and will possess suitable thickness, smelting and casting ability that this is present to China want to reach simultaneously above-mentioned parameter than difficulty.So, just simply imitate the measure that shields with metal-back, do not reach expected effect at all.

The purpose of this utility model provides a kind of double shield instrument transformer of setting up shielded coil in instrument transformer.

The purpose of this utility model is achieved in that in the existing instrument transformer that is made of iron core, secondary winding, dielectric and metal shielding, unshakable in one's determination outer or twine one deck shielded coil at least at the skin of secondary winding.

Narrate embodiment of the present utility model according to accompanying drawing below.

Fig. 1 is the thimble tube current transformer shape assumption diagram that the 600MW generating set is used.

Fig. 2 is the left view of Fig. 1 and adopts 1/4th cutaway views.

Fig. 3 is the thimble tube current transformer shape assumption diagram that the 300MW generating set is used.

Fig. 4 is left view and 1/4th cutaway views of Fig. 3.

Fig. 5 is the thimble tube current transformer shape assumption diagram that is enclosed within Fig. 3.

Fig. 6 is left view and 1/4th cutaway views of Fig. 5.

Shown in Fig. 1-6, its basic structure of the instrument transformer of this structure is similar, and its outermost layer is an endless metal screening can 1, and shell 1 can adopt the aluminium of as cast condition or copper just can satisfy the demand, and the profile of shell 1 and thickness should be according to the size of instrument transformer and service conditions and is different.In shell 1 insulating material such as the dielectric 2 of common usefulness, dielectric 2 available epoxies, unsaturated-resin and butadiene rubber.Be secondary winding 3 in medium 2, the canoe of secondary winding 3 and the number of turn are all with existing identical.Being shielded coil 4 in secondary winding 3, is the iron core 5 of this instrument transformer in the shielded coil 4, and shielded coil 4 is to be arranged between secondary winding 3 and the iron core 5.The quick pushing manipulation of shielded coil 4 is: it should twine one deck at least outside unshakable in one's determination 5, its direction of winding is to twine by the cross-directional on the iron core 5.If be around one deck (is a circle to annular unshakable in one's determination) shielded coil 4: in 5 outsides unshakable in one's determination earlier by necessarily around to (left side around to or right around to all can) equably around full unshakable in one's determination 5 half, then with opposite around to around expiring second half iron core 5.It should be noted: each half screen on unshakable in one's determination 5 covers coil 4, and its number of turn must equate that two halves weld together mutually around the head and the tail to opposite shielded coil 4 then.Consider that shield effectiveness is better, can also become 90 ° (these 90 ° be meant for the annular of whole instrument transformer) again around one deck shielded coil at the skin of ground floor shielded coil 4 with ground floor shielded coil starting point, or 90 ° of following inequality are more around the multilayer screen coil.The winding of above shielded coil 4 is to twine near unshakable in one's determination 5, but this coil 4 also can twine at the skin of secondary winding 3, its winding identical with around iron core 5, and this also can reach shield effectiveness preferably.

Be provided with installing hole 6, secondary winding outlet box 7 and nameplate 8 in the outside of shell 1.Because metal shell 1 when playing shielding action, produces circulation and heat, for better heat radiation, also can be provided with fin 9 on bigger transformer casing 1.

The utility model is simple in structure, dependable performance, because it has adopted shielded coil, like this as long as will reach the shield effectiveness that is better than external high conductivity metal shell with common metal shell, and metal-back itself can play again the effect of protection transformer.

Claims (4)

1, a kind of double shield instrument transformer comprises iron core, secondary winding and dielectric and metal shell, it is characterized in that: outside instrument transformer unshakable in one's determination or twine the shielded coil of one deck at least outside the secondary winding.

2, double shield instrument transformer according to claim 1 is characterized in that: every layer of shielded coil is a left side around to coil around half of full iron core or secondary winding, and second half is right around to coil, and two around the equal turn numbers to coil, and be end to end.

3, double shield instrument transformer according to claim 2 is characterized in that: the winding starting point of every layer of shielded coil differs 90 °.

4, double shield instrument transformer according to claim 1, it is characterized in that: metal shell is established fin.

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