CN101958191B - Zero sequence current mutual inductor - Google Patents

Abstract

The invention relates to a zero-sequence current transformer, the center of the zero-sequence current transformer body (1) is provided with a separation area, which is divided into a front separation area structure (11) of the transformer main body and a separation area structure (12) at the back of the transformer main body ); the front separation area structure (11) of the main body of the transformer and the separation area structure (12) on the back of the main body of the transformer are both cross-protruding structures, and are equally divided into four separation areas, and the conductive copper rod (2) and the back conductive copper bar A whole; the conductive copper rod (2) is set in the central separation area of the zero-sequence current transformer body (1), and the conductive copper rod (2) is provided with a threaded hole (2-a), and the screw (4) passes through the zero-sequence current transformer The current transformer connects the front conductive copper bar to the back conductive copper bar welded on the conductive copper rod (2), the front conductive copper bar is located in the front separation area structure (11) of the main body of the transformer, and the back conductive copper bar is located on the back of the main body of the transformer Separated area structure (12).

Description

A zero-sequence current transformer

technical field

The invention relates to a zero-sequence current transformer, in particular to a zero-sequence current transformer for a residual current circuit breaker.

Background technique

In the three-phase low-voltage power supply system, when the load and insulation are symmetrical, the vector sum of the three-phase currents is equal to zero. If the insulation of a certain phase of the three-phase power grid is damaged or leakage or grounding occurs, the vector sum of the three-phase currents is not zero, and this current is generally called zero-sequence current. The zero-sequence current transformer is used to measure the magnitude of the zero-sequence current. Put the transformer on the outside of the conductive rod, that is, the three-phase current passes through the iron core of the zero-sequence current transformer as its primary side (the primary side of the primary wire), and according to the requirements of sensitivity and angular characteristics, wind the iron core A coil with several turns acts as its secondary side. When a leakage or ground fault occurs in the primary system, a zero-sequence current will be generated. Using the principle of electromagnetic induction, an electric potential (or current) will be induced on the secondary side. By measuring the magnitude and phase of the secondary signal, it can be known Grid leakage.

In the residual current circuit breaker, the zero-sequence current transformer is an important part. Whether the structural design of the zero-sequence current transformer is reasonable will directly affect the overall volume design and compact structure design of the residual current circuit breaker.

At present, traditional zero-sequence current transformers used in residual current circuit breakers generally consist of a transformer body and conductive copper bars. Due to the limited internal space of the leakage circuit breaker, the volume of the main body of the transformer is also limited, so the shape of the conductive copper bar is bent, and it is very difficult to actually install the conductive copper bar, especially for the four-phase transformer. At the same time, due to the main circuit structure of the zero-sequence current transformer, the three-phase conductive copper bars (or four-phase) need to be insulated from each other. The traditional method is to wrap insulating tape on the surface of the conductive copper bars, which is very easy to cause If the insulating tape is scratched and damaged, it is necessary to re-wrap the insulating tape and re-thread the row, which increases the workload; the conductive copper row behind the traditional zero-sequence current transformer also takes up space at the connection with the thermal element of the trip unit. Therefore, the zero-sequence current transformer is an important consideration when designing a residual current circuit breaker.

Contents of the invention

Technical problems to be solved:

Aiming at the above deficiencies, the present invention provides a new type of zero-sequence current transformer structure, which not only solves the defects of the original zero-sequence current transformer in threading, but also does not increase the volume of the zero-sequence current transformer, and the assembly convenient.

Technical solutions:

A zero-sequence current transformer, comprising a zero-sequence current transformer body, a conductive copper rod, a first back conductive copper bar, a second back conductive copper bar, a first front conductive copper bar, a second front conductive copper bar, and screws;

The center of the zero-sequence current transformer body is provided with a separation area, which is divided into the front separation area structure of the transformer body and the rear separation area structure of the transformer body; the front separation area structure of the transformer body and the rear separation area structure of the transformer body are cross-convex structure; the structure of the front separation area of the main body of the transformer divides the front into the first area on the front, the second area on the front, the third area on the front, and the fourth area on the front; the separation area structure on the back of the main body of the transformer divides the back into the first area on the back, The second area on the back, the third area on the back, and the fourth area on the back;

The first back conductive copper bar and the second back conductive copper bar are provided with connection holes connected to the trip unit;

One end of the first front conductive copper bar and the second front conductive copper bar is provided with a connection hole for fastening the external wiring bar and the circuit breaker, and the first front conductive copper bar and the second front conductive copper bar are connected to the circuit breaker base. , process hole; the other end is provided with the fourth hole on the front side;

The conductive copper rod is integrated with the first back conductive copper bar and the second back conductive copper bar; A second back conductive copper bar is respectively located in the third area and the fourth area on the back;

The conductive copper bar is provided with threaded holes, and the screws are installed on the threaded holes through the fourth hole on the front of the first front conductive copper bar and the second front conductive copper bar. The screws pass through the zero-sequence current transformer to connect the first front conductive copper The row and the second front conductive copper row are connected to the first back conductive copper row and the second back conductive copper row welded on the conductive copper bar;

The first front conductive copper bar is located in the second front area, and the two second front conductive copper bars are located in the third front area and the fourth front area.

The connection holes connected to the release provided on the first back conductive copper bar and the second back conductive copper bar are the first back hole and the second back hole arranged at one end.

One end of the first front conductive copper bar and the second front conductive copper bar is provided with a connection hole for fastening the external terminal block and the circuit breaker, which is the first hole on the front; the first front conductive copper bar and the second front conductive copper bar The connection hole between the row and the circuit breaker base is the second hole on the front; the process hole is the third hole on the front.

The first front conductive copper bar and the second front conductive copper bar are common wiring copper bars.

The second back conductive copper bar is the heating element material, the first back conductive copper bar material is divided into two types, the part with the first hole on the back and the second hole on the back is the heating element material, and the other part is the common wiring copper bar.

Beneficial effect:

The four separation areas in the center of the transformer body of the present invention play the role of insulation protection, reducing the process of wrapping the conductive copper bars with insulating tape and shortening the working hours; the conductive copper rods are provided with threaded holes for screw fixing the front and rear conductive copper bars , which avoids the complicated threading process, saves the space occupied by the nut, and is more convenient to install; the threaded holes (the first hole on the back and the second hole on the back) at the connection between the conductive copper bar on the back and the release device are set in the vertical position of the copper bar There is no bending structure in the part, which saves space in connection with the trip unit.

Description of drawings

Figure 1 is a schematic structural diagram of a zero-sequence current transformer;

Figure 2 is a rear view of the zero-sequence current transformer;

Fig. 3 is the structural representation of conductive copper row and conductive copper bar on the back side of the present invention;

Fig. 4 is the structural representation of front conductive copper bar of the present invention;

Fig. 5 is the front view of the zero-sequence current transformer body of the present invention;

Fig. 6 is the rear view of the zero-sequence current transformer body of the present invention;

Figure 7 is a schematic diagram of the connection between the zero-sequence current transformer and the release;

Detailed ways

The present invention will be described in further detail below in conjunction with the accompanying drawings and specific embodiments.

As shown in Figures 1 to 7, 1 is the zero-sequence current transformer body; 11 is the front separation area structure of the transformer main body, 11-a is the first front area, 11-b is the second front area, and 11-c is The third area on the front, 11-d is the fourth area on the front; 12 is the partition structure on the back of the main body of the transformer, 12-a is the first area on the back, 12-b is the second area on the back, and 12-c is the third area on the back , 12-d is the fourth area on the back; 2 is the conductive copper rod, 2-a is the threaded hole; 31-a is the first back conductive copper row, 31-b is the second back conductive copper row, 32-a is the first A front conductive copper bar, 32-b is the second front conductive copper bar; 4 is a screw, 5 is the first hole on the back, 6 is the second hole on the back, 7 is the first hole on the front, 8 is the second hole on the front, 9 The third hole on the front side, and 10 is the fourth hole on the front side.

The zero-sequence current transformer of the present invention includes a zero-sequence current transformer body 1, a conductive copper rod 2, a first back conductive copper bar 31-a, a second back conductive copper bar 31-b, and a first front conductive copper bar 32- a, the second front conductive copper bar 32-b, and screws 4 .

The center of the zero-sequence current transformer body 1 is provided with a separation area, which is divided into a front separation area structure 11 of the transformer body and a rear separation area structure 12 of the transformer body; the front separation area structure 11 and the back separation area structure 12 are cross protrusions Structure; the transformer main body front separation area structure 11 divides the front into the first front area 11-a, the second front area 11-b, the third front area 11-c, and the fourth front area 11-d (as shown in Figure 5 shown); the separation area structure 12 on the back of the main body of the transformer divides the back into the first area 12-a on the back, the second area 12-b on the back, the third area 12-c on the back, and the fourth area 12-d on the back (as shown in Figure 6 shown);

One end of the first back conductive copper bar 31-a and the second back conductive copper bar 31-b is provided with a first hole 5 and a second hole 6 on the back;

One end of the folded edge of the first front conductive copper row 32-a and the second front conductive copper row 32-b is provided with a front first hole 7 and a front second hole 8, and the other end is provided with a front fourth hole 10. A third front hole 9 is provided on the vertical surface close to the folding edge;

The first hole 5 on the back, and the second hole 6 on the back are connection holes connected with the trip unit;

The first hole 7 on the front is the connecting hole for fastening the external terminal block and the circuit breaker, the second hole 8 on the front is the connection hole between the first front conductive copper bar and the second front conductive copper bar and the base of the circuit breaker, and the third front hole 9 For the process hole;

The conductive copper bar 2 and the back conductive copper bar are welded into a whole; the conductive copper bar 2 is arranged in the central separation area of the zero-sequence current transformer body 1, and the first back conductive copper bar 31-a is located in the second back area 12-b. The two second back conductive copper bars 31-b are located in the third rear area 12-c and the fourth rear area 12-d;

The conductive copper rod 2 is provided with a threaded hole 2-a, and the screw 4 is installed on the threaded hole 2-a through the fourth hole 10 on the front side of the front conductive copper bar, and the screw 4 passes through the zero-sequence current transformer to connect the front conductive copper bar It is connected with the conductive copper row welded on the back of the conductive copper rod 2;

The first front conductive copper bar 32-a is located in the second front area 11-b, and the two second front conductive copper bars 32-b are located in the third front area 11-c and the fourth front area 11-d;

The first front conductive copper row 32-a and the second front conductive copper row 32-b are common wiring copper rows;

The second back conductive copper bar 31-b is the heating element material, the first back conductive copper bar 31-a material is divided into two types, and the part with the first hole 5 and the second hole 6 on the back is the heating element materials, and the other part is ordinary wiring copper bars.

Conductive copper rods 2 are placed in the four separate areas in the center of the zero-sequence current transformer body 1, which can also play an insulating and protective role, reducing the process of wrapping the conductive copper bars with insulating tape.

The conductive copper rod 2 is provided with a threaded hole 2-a, which is used for the conductive copper row before and after the screw 4 is fixed, so as to avoid complicated threading procedures.

The screw 4 passes through the zero-sequence current transformer to connect the front conductive copper bar to the back conductive copper bar welded by the conductive copper rod 2. Compared with the traditional zero-sequence current transformer, the conductive copper bar is divided into two parts , connected by screws, so there is no threading process, and there is no need to increase the volume of the transformer body; at the same time, because the zero-sequence current transformer body 1 itself has a structure of separating areas, there is no need to wrap insulating tape on the conductive copper bars, shortening working hours. At the same time, the traditional transformer connects the conductive copper bar and the heating element with screws at the connection part of the conductive copper bar and the trip unit; and the back conductive copper bar in this structure itself is the material of the heating element, which saves material , Also save the internal space of the leakage circuit breaker.

Compared with the existing transformer structure, the zero-sequence current transformer in the present invention is more simplified in terms of the number of parts, and the conductive copper rod 2 is welded into a whole with the back conductive copper bar; the zero-sequence current transformer in the present invention is conductive The copper rod 2 is provided with a threaded hole 2-a, which only needs to be fastened by screws, saving the space occupied by the nut; secondly, the conductive copper row on the back of the existing transformer is provided with a threaded hole at the bending place for connecting with The release is connected, and the threaded holes (the first hole 5 on the back and the second hole 6 on the back) at the connection between the back conductive copper bar and the release in the zero-sequence current transformer of the present invention are arranged on the vertical part of the copper bar. The bending structure saves space in the connection with the trip unit.

Although the present invention has been disclosed as above with preferred embodiments, they are not intended to limit the present invention. Any skilled person can make various changes or modifications without departing from the spirit and scope of the present invention. Therefore The protection scope of the present invention should be defined by the protection scope of the claims of the present application.

Claims (5)

1. A zero-sequence current transformer, characterized in that: it comprises a zero-sequence current transformer body (1), a conductive copper rod (2), a first back conductive copper bar (31-a), a second back conductive copper bar (31-b), first front conductive copper row (32-a), second front conductive copper row (32-b), screw (4); The center of the zero-sequence current transformer body (1) is provided with a separation area, which is divided into a front separation area structure (11) of the transformer body and a separation area structure (12) at the back of the transformer body; a separation area structure (11) at the front of the transformer body and the separation area structure (12) on the back of the main body of the transformer are both cross-protruding structures; the front separation area structure (11) of the main body of the transformer divides the front into the first front area (11-a) and the second front area (11-b ), the third area on the front (11-c), the fourth area on the front (11-d); (12-b), the third area on the back (12-c), the fourth area on the back (12-d); The first back conductive copper bar (31-a) and the second back conductive copper bar (31-b) are provided with connection holes connected to the release; One end of the first front conductive copper bar (32-a) and the second front conductive copper bar (32-b) is provided with a connection hole for fastening the external terminal block and the circuit breaker, a connection hole with the circuit breaker base, and a process hole , the other end is provided with a front fourth hole (10); The conductive copper rod (2) is integrated with the first back conductive copper bar (31-a) and the second back conductive copper bar (31-b); the conductive copper bar (2) is arranged on the zero-sequence current transformer body (1 ), the first rear conductive copper row (31-a) is located in the second rear region (12-b), and the two second rear conductive copper rows (31-b) are respectively located in the third rear region (12-b). c) and the fourth region on the back (12-d); Conductive copper bar (2) is provided with threaded hole (2-a), and screw (4) passes through the front fourth of the first front conductive copper row (32-a) and the second front conductive copper row (32-b). The hole (10) is installed on the threaded hole (2-a), and the screw (4) passes through the zero-sequence current transformer to connect the first front conductive copper bar (32-a) and the second front conductive copper bar (32-b) Be connected to the first back conductive copper bar (31-a) and the second back conductive copper bar (31-b) welded on the conductive copper bar (2); The first front conductive copper row (32-a) is located in the second front area (11-b), and the two second front conductive copper bars (32-b) are located in the third front area (11-c) and the fourth front area (11-d). 2. A zero-sequence current transformer according to claim 1, characterized in that: the first back conductive copper bar (31-a) and the second back conductive copper bar (31-b) are provided with The connecting holes connected with the release are the first hole (5) and the second hole (6) on the back which are arranged at one end. 3. A zero-sequence current transformer according to claim 1, characterized in that: one end of the first front conductive copper row (32-a) and the second front conductive copper row (32-b) is arranged There is a connection hole for fastening the external terminal block and the circuit breaker to the first hole (7) on the front; the first front conductive copper bar (32-a) and the second front conductive copper bar (32-b) are connected to the circuit breaker base The connection hole is the second hole (8) on the front side; the process hole is the third hole (9) on the front side. 4. A zero-sequence current transformer according to claim 1, characterized in that: the first front conductive copper bar (32-a) and the second front conductive copper bar (32-b) are common wiring Copper row. 5. A zero-sequence current transformer according to claim 2, characterized in that: said second back conductive copper bar (31-b) is a heating element material, said first back conductive copper bar ( 31-a) There are two kinds of materials, the part with the first hole (5) and the second hole (6) on the back is the heating element material, and the other part is the common wiring copper bar.

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