CN206274478U - A secondary insulation resistor - Google Patents

Abstract

The utility model discloses a secondary insulation resistor, including shell and resistance circuit subassembly, the resistance circuit subassembly is including a plurality of resistance cards that parallel and the boom that is used for a plurality of resistance cards to get up in cluster, the both ends of boom are worn out from the both sides of shell in order to erect the inside at the shell to the resistance card, the surface cladding of boom has the outside that mica layer and mica layer extend to the shell, the boom is worn to be equipped with the porcelain and is separated shell inner wall and resistance card, be provided with interior mica ring between the inner wall of porcelain and shell, the outside part that the shell was worn out to the boom is provided with the mounting that is used for locking the boom, be provided with outer mica ring between the outer wall of mounting and shell. Compared with the prior art, the mica layer extends to the position where the string rod penetrates through the side wall of the shell, primary insulation is realized between the shell and the resistance loop assembly, a porcelain piece and an inner mica ring are also arranged between the inner wall of the resistance chip and the inner wall of the shell, and a secondary insulation effect is formed, so that a double insulation structure is adopted, and the insulation performance between the shell and the resistance loop assembly is improved.

Description

A secondary insulation resistor

technical field

The utility model relates to the technical field of resistors, in particular to a secondary insulation resistor.

Background technique

Crowbar resistors are mainly used in the low voltage ride through technology of wind power inverters. It is used on the rotor side of the wind turbine to bypass the converter on the rotor side, and prevent the DC bus voltage from being too high and the rotor current from being too large when a low voltage disturbance occurs in the power grid. Mainly working in the fault state, damping the stator flux linkage, the Crowbar resistor can dissipate huge energy in an instant. As a clean and renewable energy, wind energy has attracted more and more attention from all over the world. Wind power converters can optimize the operation of wind power generation systems, realize variable speed and constant frequency power generation within a wide wind speed range, and improve fan efficiency and transmission chain work. conditions, reduce generator loss, improve operating efficiency, and increase wind energy utilization. Wind converters are widely used because of their excellent control performance and good grid adaptability. The application conditions of wind power crowbar resistors are relatively harsh. The surface of the resistor’s casing often generates condensation due to high humidity. The existing casing and resistance circuit components have low insulation performance and insufficient electrical reliability, which cannot meet the requirements of the resistor in harsh conditions. environmental requirements.

Contents of the invention

In view of the above-mentioned technical problems in the prior art, the utility model provides a secondary insulation resistor which improves the insulation performance between the casing and the resistance circuit assembly.

In order to achieve the above object, the utility model provides the following technical solutions:

A secondary insulation resistor is provided, which includes a casing and a resistance loop assembly. The resistance loop assembly includes a plurality of parallel resistance slices and a string bar for connecting the multiple resistance slices in series. The side is pierced to erect the resistance sheet inside the shell. The surface of the string rod is covered with a mica layer and the mica layer extends to the outside of the shell. An inner mica ring is arranged between the inner walls of the casing, and a fixing piece for locking the stringing rod is arranged at the place where the skewer passes through the outside of the casing, and an outer mica ring is arranged between the fixing piece and the outer wall of the casing, and the inner mica ring and the outer The mica rings are all worn on the string rods.

Wherein, the fixing member is a nut.

Wherein, a flat gasket is arranged between the outer mica ring and the fixing member, and the flat gasket is passed through the string rod.

Wherein, the thickness of the flat gasket is 2.5 millimeters, and the thickness of the inner mica ring and the outer mica ring are both 1.5 millimeters.

Wherein, the length of the skewer passing out of the casing ranges from 2 mm to 3.5 mm.

Wherein, the string bar is also connected with a ceramic sleeve for insulating between two adjacent resistor sheets and a conductive ring for connecting multiple resistor sheets in series or in parallel.

The beneficial effects of the utility model:

A secondary insulation resistor of the present utility model includes a casing and a resistance loop assembly. The resistance loop assembly includes a plurality of parallel resistance slices and a string bar for connecting the multiple resistance slices in series. The two ends of the string bar are from The two sides of the casing are pierced to erect the resistor inside the casing. The surface of the string rod is covered with a mica layer and the mica layer extends to the outside of the casing. The string rod is pierced with porcelain parts to separate the inner wall of the casing from the resistor sheet. An inner mica ring is arranged between the porcelain part and the inner wall of the shell, and a fixing piece for locking the stringing rod is set at the place where the skewer passes through the outside of the shell, and an outer mica ring is set between the fixing piece and the outer wall of the shell, and the inner mica Both the ring and the outer mica ring are passed through the string rod. Compared with the prior art, the utility model is coated with a mica layer on the surface of the string rod, and the mica layer extends to the place where the string rod passes through the side wall of the shell, so that the shell and the resistance circuit assembly are separated by the mica layer. To achieve preliminary insulation, there is also a porcelain piece and an inner mica ring between the resistor sheet and the inner wall of the shell to form a second insulation effect. Therefore, the double insulation structure greatly improves the insulation performance between the shell and the resistance circuit assembly.

Description of drawings

Fig. 1 is a perspective view of a secondary insulation resistor in the embodiment.

Fig. 2 is a side view of a secondary insulation resistor in the embodiment.

Fig. 3 is a sectional view along G-G direction in Fig. 2 .

FIG. 4 is an enlarged view of A in FIG. 3 .

Fig. 5 is a sectional view along B-B direction in Fig. 2 .

Reference signs:

shell1;

resistor sheet 2;

Skewer 3;

Porcelain set 4;

Conductive ring 5;

mica layer 6;

Nut 7;

Inner mica ring 8;

outer mica ring 9;

flat gasket 10;

Porcelain 11.

detailed description

The utility model is described in detail below in conjunction with specific embodiments and accompanying drawings.

A secondary insulation resistor of this embodiment, as shown in Figures 1 to 5, includes a housing 1 and a resistance loop assembly, the resistance loop assembly includes a plurality of resistance sheets 2 in parallel and is used to connect the plurality of resistance sheets 2 in series The four string rods 3 that get up, four string rods 3 are mutually parallel, and wherein two string rods 3 are placed left and right to string up resistor slices 2, and the other two string up and down place to string up resistor slices 2, and string rods 3 are also connected in string for making adjacent two The ceramic sleeve 4 for insulation between the resistance pieces 2 and the conductive ring 5 for connecting multiple resistance pieces 2 in series or in parallel to meet different resistance requirements. The two ends of the string rod 3 pass through both sides of the shell 1 to erect the resistance sheet 2 inside the shell 1, the surface of the string rod 3 is coated with a mica layer 6 and the mica layer 6 extends to the outside of the shell 1, the string The rod 3 is pierced with a porcelain piece 11 to separate the inner wall of the shell 1 from the resistor sheet 2, an inner mica ring 8 is arranged between the porcelain piece 11 and the inner wall of the shell 1, and a ring 8 is provided at the place where the string rod 3 passes through the outside of the shell 1. The fixing part for locking the string rod 3 is a nut 7, and an outer mica ring 9 is arranged between the nut 7 and the outer wall of the shell 1, and the inner mica ring 8 and the outer mica ring 9 are both installed on the string rod 3.

In this embodiment, a flat gasket 10 is arranged between the outer mica ring 9 and the fixing member, and the flat gasket 10 is installed on the string rod 3. When the nut 7 fixes the string rod 3, the flat gasket 10 is screwed in and compressed, so that Indirect compression of the outer mica ring 9 prevents the nut 7 from directly crushing the outer mica ring 9.

In this embodiment, the thickness of the flat gasket 10 is 2.5 mm, and the thickness of the inner mica ring 8 and the outer mica ring 9 are both 1.5 mm. The length of the skewer 3 passing through the shell 1 ranges from 2 mm to 3.5 mm.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present utility model, rather than limiting the protection scope of the present utility model. Personnel should understand that the technical solution of the utility model can be modified or equivalently replaced without departing from the essence and scope of the technical solution of the utility model.

Claims (6)

1. A secondary insulation resistor is characterized in that: it comprises a shell and a resistance loop assembly, the resistance loop assembly includes a plurality of resistance sheets in parallel and a string bar for connecting a plurality of resistance sheets in series, and the two ends of the string bar The part passes through both sides of the shell to erect the resistor sheet inside the shell. The surface of the string rod is covered with a mica layer and the mica layer extends to the outside of the shell. Porcelain pieces, an inner mica ring is set between the porcelain piece and the inner wall of the shell, a fixing piece for locking the stringing rod is set at the place where the skewer passes through the outside of the shell, and an outer mica ring is set between the fixing piece and the outer wall of the shell , both the inner mica ring and the outer mica ring are set on the skewer. 2. A secondary insulation resistor according to claim 1, characterized in that: said fixing member is a nut. 3. A secondary insulation resistor according to claim 1, characterized in that: a flat gasket is arranged between the outer mica ring and the fixing member, and the flat gasket is passed through the string rod. 4. A secondary insulation resistor according to claim 3, characterized in that: the thickness of the flat gasket is 2.5 mm, and the thickness of the inner mica ring and the outer mica ring are both 1.5 mm. 5. A secondary insulation resistor according to claim 1, characterized in that: the length of the string rod passing through the shell is 2mm~3.5mm. 6. A secondary insulation resistor according to claim 1, characterized in that: the string bar is also connected in series with a porcelain sleeve for insulating between two adjacent resistor sheets and for insulating between multiple resistor sheets. Conductive rings in series or parallel.