CN203721441U - Energy-saving grounding transformer for three-phase three-dimensional iron core - Google Patents

Abstract

The utility model discloses an energy-saving grounding transformer for a three-phase three-dimensional iron core. The energy-saving grounding transformer comprises an upper clamping member, a lower clamping member, and a three-dimensional coil iron core, wherein the three-dimensional coil iron core is arranged between the upper clamping member and the lower clamping member and is in a triangular three-dimensional structure formed by splicing three same iron core single frames; three core limbs corresponding to the three phases of the transformer are formed by the three-dimensional coil iron core, and are respectively sleeved with coils, the coil of each phase is divided into an upper coil and a lower coil, the winding directions of the upper coils and the lower coils are opposite and the coils of the three phases adopt a Z-shaped connection mode. According to the transformer, the three-phase magnetic circuits of the three-dimensional coil iron core are completely symmetrically equal in length and equal in three-phase magnetic resistance, so that the grounding transformer has the advantages of low no-load loss, small no-load current, low noise and the like when the functions of the grounding transformer can be realized, and accords with the operation characteristics of long time no-load and short time overload, so that the grounding transformer is a new generation energy-saving grounding transformer product.

Description

A three-phase three-dimensional wound core energy-saving grounding transformer

technical field

The utility model relates to the technical field of electric equipment, in particular to a three-phase three-dimensional wound core energy-saving grounding transformer.

Background technique

With the increasing growth and development of the power industry, the neutral point ungrounded system in the initial stage of the power grid can no longer meet the current needs. The number of cable circuits in the urban power grid is gradually increasing, and the capacitive current is increasing (over 10A). At this time, the grounding arc cannot be extinguished reliably, which will cause overvoltage to cause electrical equipment insulation breakdown and open circuit accidents. In order to prevent accidents, provide enough zero-sequence impedance and zero-sequence voltage for the system, and make the grounding protection operate reliably, it is necessary to artificially establish a neutral point so that the grounding resistance can be connected to the neutral point. In order to solve the above problems, grounding transformers are produced under such circumstances. However, the operating characteristics of most grounding transformers are: long-term no-load, short-term overload. Therefore, how to reduce the no-load loss of the grounding transformer has become the primary consideration for the economic operation of the grounding transformer.

Utility model content

In order to overcome the shortcomings of the existing technology, the purpose of the utility model is to provide a three-phase three-dimensional wound core energy-saving grounding transformer with three-phase balance, low no-load loss, small no-load current and low noise.

The technical scheme that the utility model adopts is:

A three-phase three-dimensional wound core energy-saving grounding transformer, comprising an upper clamp and a lower clamp, and a three-dimensional wound core installed between the upper clamp and the lower clamp, the three-dimensional wound core is composed of three identical iron cores A triangular three-dimensional structure composed of frames; the three-dimensional wound iron core forms three iron core columns, and the three-phase coils of the transformer are respectively set on the three iron core columns. Each phase coil is divided into two parts, an upper coil and a lower coil, and the upper coil In contrast to the winding direction of the lower coil, the three-phase coil adopts a Z-type connection.

As an improvement of the above technical solution, the three-phase coils are correspondingly connected with a three-phase connection terminal and a zero-phase connection terminal.

Further, each phase coil is provided with an interface for connecting with other coils, three-phase connection terminals, and 0-phase connection terminals, and a voltage regulating terminal.

As an improvement of the above technical solution, each iron core single frame is wound from several trapezoidal silicon steel strips.

As an improvement of the above technical solution, both the upper clamping part and the lower clamping part are triangular frames welded by steel materials, and the upper clamping part and the lower clamping part are connected by a compression screw.

The beneficial effects of the utility model are: the three-phase three-dimensional wound core energy-saving grounding transformer, the coils of which adopt a Z-type connection mode, which can ensure the balance of the magnetic potential on each iron core column. The two coils on each phase core leg are wound in opposite directions, so that the zero-sequence current flowing through the two coils of the concentric leg is equal, and the voltage drop of the zero-sequence current on the coil is very small, showing low impedance. The utility model effectively combines the grounding transformer and the three-dimensional wound core, so that the grounding transformer has the advantages of low no-load loss, small no-load current, and low noise while realizing its functions, which is exactly in line with the grounding transformer's long-time no-load, The operating characteristics of short-term overload are a new generation of energy-saving grounding transformer products.

Description of drawings

Below in conjunction with accompanying drawing and example the utility model is described further.

Fig. 1 is the structural representation of the utility model;

Fig. 2 is a schematic structural view of the three-dimensional wound core of the present invention;

Fig. 3 is the structural representation of the coil of the present utility model;

Fig. 4 is a schematic diagram of the Z-type wiring of the present invention.

Detailed ways

Referring to Figures 1 to 4, a three-phase three-dimensional wound core energy-saving grounding transformer of the present invention includes an upper clamp 1 and a lower clamp 2, and a three-dimensional coil installed between the upper clamp 1 and the lower clamp 2 Core 3. Both the upper clamping part 1 and the lower clamping part 2 are triangular frames welded by steel materials, and the upper clamping part 1 and the lower clamping part 2 are connected by a compression screw 10 . The three-dimensional wound core is a triangular three-dimensional structure composed of three identical core single frames; the three-dimensional wound core is formed with three core columns, and the A, B, and C three-phase coils 4 of the transformer are respectively set in the three core columns. Above, each phase coil 4 is divided into two parts, an upper coil and a lower coil, and the winding directions of the upper coil and the lower coil are opposite, and the three-phase coil 4 adopts a Z-type connection method. The Z-type connection mode adopted by the utility model can ensure the balance of the magnetic potential on each iron core column. The coil 4 on each phase core column is divided into an upper coil and a lower coil with the same number of turns, wherein the tail of the upper coil of phase A is connected to the head of the lower coil of phase C, and the tail of the upper coil of phase B is connected to the head of the lower coil of phase A. The tail of the upper coil of phase C is connected to the head of the lower coil of phase B, and finally the tails of the lower coils of phase A, B, and C are connected and drawn out as a neutral point. Since the two coils on each phase core column are wound in opposite directions, the zero-sequence current flowing through the two coils in the concentric column is equal and opposite in direction, which just cancels out, so the voltage drop of the zero-sequence current on the coil is very small, showing low impedance , low no-load loss, and more than 90% of the transformer capacity can be utilized. The utility model effectively combines the grounding transformer and the three-dimensional wound iron core. The three iron core columns of the three-dimensional wound iron core are distributed in an equilateral triangle, so that the three-phase coil 4 is also arranged in an equilateral triangle. The center lines of the three-phase coil 4 are parallel to each other, so that the three-phase The phase magnetic circuits are completely symmetrical and equal in length. Since the three-phase magnetic circuit of the iron core is completely symmetrical and equal in length, and the three-phase reluctance is equal, the grounding transformer has the advantages of low no-load loss, small no-load current, and low noise while realizing its function, which is exactly in line with the grounding transformer. The operating characteristics of long-term no-load and short-time overload are a new generation of energy-saving grounding transformer products.

Specifically, one side of the upper clamp 1 is provided with A, B, C three-phase connection terminals 5 and a 0-phase connection terminal 6, and the A, B, C three-phase connection terminals 5 and 0-phase connection terminals 6 are respectively connected to A, B, and C three-phase coils 4 are correspondingly connected. Connect to the electric load through the A, B, C three-phase terminal 5 and the 0-phase terminal 6.

Specifically, each phase coil 4 is provided with an interface 8 for connecting with other coils, a three-phase connection terminal 5 and a 0-phase connection terminal 6 , and a voltage regulating terminal 9 .

Specifically, each core single frame of the three-dimensional wound core is formed by winding several trapezoidal silicon steel strips 7, the silicon steel strips 7 are tightly wound, and the magnetic conduction direction of the silicon steel strips 7 is exactly the same as the magnetic circuit direction of the iron core. Consistent, the vibration is small when working, which solves the noise caused by the incoherent magnetic circuit of the stacked iron core.

The three-phase magnetic circuit of the three-dimensional wound iron core of the utility model is completely symmetrical and equal in length, and the three-phase reluctance is equal. Therefore, the grounding transformer has the advantages of low no-load loss, small no-load current, and low noise while realizing its functions. It is in line with the long-time no-load and short-time overload operation characteristics of grounding transformers. It is a new generation of energy-saving grounding transformer products, and it is also suitable for grounding transformers with secondary windings.

The above is only a preferred embodiment of the utility model, and the utility model is not limited to the above-mentioned embodiment, as long as it achieves the technical effect of the utility model by the same means, it should belong to the protection scope of the utility model.

Claims (5)

1. a three-phase stereo is rolled up energy-conservation grounding transformer unshakable in one's determination, it is characterized in that: comprise upper clamping piece (1) and lower clamping piece (2), and being arranged on the three dimensional wound core (3) between upper clamping piece (1) and lower clamping piece (2), described three dimensional wound core (3) is the triangle stereochemical structure being pieced together by three identical single frames unshakable in one's determination; Described three dimensional wound core (3) is formed with three core limbs, the three-phase coil of transformer (4) is set on three core limbs, each phase coil (4) is divided into upper coil and lower coil two parts, and upper coil and lower coil around on the contrary, three-phase coil (4) adopts the Z-type mode of connection.

2. a kind of three-phase stereo volume according to claim 1 energy-conservation grounding transformer unshakable in one's determination, is characterized in that: described three-phase coil (4) correspondence is connected with three-phase terminal (5) and 0 phase connection terminal (6).

3. a kind of three-phase stereo according to claim 2 is rolled up energy-conservation grounding transformer unshakable in one's determination, it is characterized in that: on each phase coil (4), be provided with the interface (8) for being connected with other coil, three-phase terminal (5), 0 phase connection terminal (6), and a pressure regulation terminal (9).

4. a kind of three-phase stereo volume according to claim 1 energy-conservation grounding transformer unshakable in one's determination, is characterized in that: each single frame unshakable in one's determination is to be formed by some trapezoidal silicon strips (7) coiling.

5. a kind of three-phase stereo according to claim 1 is rolled up energy-conservation grounding transformer unshakable in one's determination, it is characterized in that: described upper clamping piece (1) and lower clamping piece (2) are the triangular framing that steel are welded into, described upper clamping piece (1) is connected by clamping screw (10) with lower clamping piece (2).