CN107863211A - High-voltage damping resistor and manufacturing process thereof - Google Patents

Abstract

The invention relates to the technical field of resistors, in particular to a high-voltage damping resistor and a manufacturing process thereof, wherein the high-voltage damping resistor structurally comprises a resistance belt, the resistance belt is coated by a heat-conducting coating body, two end parts of the resistance belt extend out of the heat-conducting coating body, a heat-radiating pipe is also inserted in the heat-conducting coating body, and a pipe orifice of the heat-radiating pipe leads to the outside of the heat-conducting coating body; the high-voltage damping resistor is cast in vacuum to form the epoxy resin cast body, so that the strength of the epoxy resin cast body is improved, and the defects are reduced.

Description

A high-voltage damping resistor and its manufacturing process

technical field

The invention relates to the technical field of resistors, in particular to a high-voltage damping resistor and a manufacturing process thereof.

Background technique

In the high-voltage power system, it is necessary to set a damping resistor between the gap or the bypass switch, which is used to limit and damp the current of the capacitor in the high-voltage power system, so as to prevent the discharge process damaged. Since damping resistors are used in high-voltage power systems, there will be large electric heat latent in the resistors. In the prior art, in order to ensure the heat dissipation performance of damping resistors, the resistance strips or resistance wires of damping resistors are exposed to the environment. However, the above-mentioned exposed resistance wire will make the protection performance of the resistance wire or resistance strip poor, so that the accumulated pollution will cause the problem of easy arcing of the resistor, which will affect the service life of the damping resistor. Moreover, the heat radiation generated by the exposed resistance wire will affect the parts around it for a long time, which is not conducive to maintaining the stability of the high-voltage power system; in addition, the damping resistor needs to have a certain volume to ensure the heat dissipation effect of the resistor itself.

Contents of the invention

In view of the above-mentioned technical problems in the prior art, the present invention provides a high-voltage damping resistor with good sealing performance, good heat dissipation and small volume and a manufacturing process capable of manufacturing the high-voltage damping resistor with the above-mentioned advantages.

To achieve the above object, the present invention provides the following technical solutions:

A high-voltage damping resistor is provided, including a resistance band, the resistance band is covered by a heat-conducting coating body, both ends of the resistance band protrude from the heat-conducting coating body, and the heat-conducting coating body is interspersed with A heat dissipation pipe, the nozzle of the heat dissipation pipe leads to the heat conduction cladding body.

Wherein, the thermally conductive cladding body is an epoxy resin casting body.

Wherein, the bottom of the heat-conducting covering body is provided with a supporting bracket.

Wherein, the supporting bracket includes a bottom plate and an insulator arranged under the bottom plate for supporting the bottom plate, and the epoxy resin casting body is fixed on the bottom plate.

Wherein, the bottom plate includes a flat plate, and the opposite edges of the flat plate are provided with limiting side plates for limiting the position of the epoxy resin cast body.

Wherein, the resistance band located in the heat-conducting envelope is curved.

Wherein, the heat dissipation pipes are provided with eight, and the eight heat dissipation pipes are evenly distributed on the outer periphery of the resistance band.

Wherein, the heat-conducting covering body is configured as a cuboid, and the two ends of the resistance band protrude from opposite surfaces of the cuboid.

Wherein, the epoxy resin casting body is made of the following components by weight: 90-100 parts of epoxy resin, 45-55 parts of curing agent, 15-25 parts of toughening agent, and 220-280 parts of filler.

Also provided is a method for preparing a high-voltage damping resistor, comprising the steps of:

Step 1. Preheat the vacuum casting tank to 90-94°C, preheat the mixing container to 76-80°C, weigh epoxy resin, curing agent, toughening agent and filler according to the formula, and then mix the raw materials And preheat to 46 ~ 50 ℃;

Step 2. Inject the preheated raw materials into the mixing container, heat the mixing container to 65-70°C and vacuumize it, and stir and degas the mixing material in the mixing container for 2-2.5 hours;

Step 3, place the resistance band and the heat dissipation pipe in a mold for forming the epoxy resin casting body, put the mold into the vacuum casting tank, and inject the mixture into the mold in the vacuum casting tank , the temperature of the vacuum casting tank is kept at 70-80° C., the mixed material is injected into the mold in the vacuum casting tank body, and the obtained casting body is left standing for 10-15 minutes to obtain a high-voltage damping resistor.

Beneficial effects of the present invention:

A high-voltage damping resistor of the present invention, the resistance band is covered with a heat-conducting coating body, so that the resistance band has better sealing performance, and overcomes the problem in the prior art that the exposed resistance band is easy to accumulate pollution and cause arcing , which is conducive to improving the service life of the damping resistor, and the heat-conducting coating can effectively block the heat radiation of the resistance band from directly radiating to the surrounding parts, which improves the stability of the power system where it is located; and although the heat-conducting coating prevents the middle part of the resistance band from being directly exposed to the outside The heat dissipation must be dissipated through the heat-conducting covering body, but because the heat-conducting covering body has a built-in heat dissipation pipe leading to the environment, it can effectively transfer the heat energy in the heat-conducting covering body to the environment, ensuring the heat dissipation performance of the damping resistor; in addition, Due to the good heat transfer function of the heat-conducting covering body and the heat-dissipating pipe, the heat dissipation effect can be guaranteed even if the resistor has a small volume, so that the overall volume of the damping resistor can be reduced, and the convenience of transportation and use of the damping resistor can be improved. sex.

The manufacturing process of a high-voltage damping resistor of the present invention is to cast the epoxy resin casting body in a vacuum state, and the vacuum environment can reduce the pouring temperature, thereby reducing or eliminating the internal bubbles of the material, which is beneficial to improving the epoxy resin casting body. strength and reduce the presence of its defects.

Description of drawings

Fig. 1 is the schematic diagram of a kind of high voltage damping resistor of the present invention;

Fig. 2 is a schematic side view of a high voltage damping resistor of the present invention;

Fig. 3 is a front view schematic diagram and a partial schematic diagram of a high voltage damping resistor of the present invention.

Reference signs:

Resistance band—1; epoxy resin cast body—2; heat pipe—3; bottom plate—4, flat plate—41, limit side plate—42; insulator—5.

Detailed ways

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

Example 1.

As shown in Figures 1 and 2, a high-voltage damping resistor has a resistance band 1 wrapped in an epoxy resin cast body 2, and the two ends of the resistance band 1 extend out of the epoxy resin cast body 2 , so as to be electrically connected to the external circuit, of course, the epoxy resin casting body can also be other heat-conducting covering body. As shown in Figure 3, preferably, the resistance band 1 is a resistance band made of nickel-chromium alloy and bent into a curved shape in a zigzag manner. The advantage of this is that the nickel-chromium alloy has the advantages of high resistivity and small temperature drift , and the curved shape can effectively increase the weight and strength of the resistance band. The resistance band 1 can also be a curved surface of other structures, such as a shape-forming surface, that is, as long as it is a curved surface. The epoxy resin pouring body 2 is provided with a heat dissipation pipe 3, and the heat dissipation pipe 3 surrounds the resistance band 1 evenly, and the nozzle of the heat dissipation pipe 3 communicates with the external environment. The epoxy resin casting body 2 is delivered to the environment and further discharged from the heat dissipation pipe, which not only ensures the sealing performance of the resistor but also ensures the heat dissipation effect of the resistor, and the epoxy resin casting body can reduce the heat radiation of the resistance band. Further, the epoxy resin casting body 2 is set as a cuboid, and the two ends of the resistance band 1 protrude from the corresponding surfaces of the cuboid, and eight heat dissipation pipes 3 are provided, and the eight heat dissipation pipes 3 are evenly distributed on the three resistance bands 1 The outer periphery of the heat sink, thereby enhancing the heat dissipation effect, and the eight heat dissipation pipes 3 are all mica pipes, so as to avoid short-circuit connection with the resistance band 1.

In addition, the bottom of the epoxy resin casting body 1 is provided with a supporting bracket, which has a bottom plate 4 and two insulators 5 for supporting the bottom plate 5 arranged below the bottom plate 4, the bottom plate 4 includes a flat plate 41, and the ring The epoxy resin casting body 1 is fixed on a flat plate 41 , and the opposite edge of the flat plate 41 is provided with a limiting side plate 42 for limiting the position of the epoxy resin casting body 1 .

Example 2.

A manufacturing process of a high-voltage damping resistor in this embodiment includes the following steps:

Step 1. Preheat the vacuum casting tank to 90°C, preheat the mixing container to 76°C, weigh 90 parts of epoxy resin, 45 parts of curing agent, 15 parts of toughening agent and 220 parts of filler, and add appropriate amount Accelerator, then mix the above raw materials evenly and preheat to 46°C, so that the container and raw materials are in a preheated state, preventing the problem of uneven heating or overheating of raw materials during the preparation process;

Step 2. Pour the preheated raw materials into the mixing container, then heat the mixing container to 65°C and vacuumize it. The raw materials are stirred and degassed in the mixing container for 2 hours to discharge the raw material bubbles;

Step 3: Place the resistance band and heat dissipation pipe in the damping resistor in the mold used to form the epoxy resin casting body, put the mold into the vacuum casting tank, and keep the temperature of the vacuum casting tank at 70°C , the mixed material is injected into the mold in the vacuum casting tank body, after the casting is completed, the resulting casting body is allowed to stand for 10 minutes to form the epoxy resin casting body so as to make a high-voltage damping resistor, wherein, casting in a vacuum state, can Pouring at low temperature.

Example 3.

A manufacturing process of a high-voltage damping resistor in this embodiment includes the following steps:

Step 1. Preheat the vacuum casting tank to 94°C, preheat the mixing container to 80°C, weigh 100 parts of epoxy resin, 55 parts of curing agent, 25 parts of toughening agent and 280 parts of filler, and add appropriate amount Accelerator, then mix the above raw materials evenly and preheat to 50°C, so that the container and raw materials are in a preheated state, and prevent the problem of uneven heating or overheating of raw materials during the preparation process;

Step 2. Pour the preheated raw materials into the mixing container, then heat the mixing container to 70°C and vacuumize the mixture. Stir and degas the mixture in the mixing container for 2.5 hours to discharge the raw material bubbles;

Step 3: Place the resistance band and heat dissipation pipe in the damping resistor in the mold used to form the epoxy resin casting body, put the mold into the vacuum casting tank, and keep the temperature of the vacuum casting tank at 80°C , the mixed material is injected into the mold in the vacuum casting tank body, after the casting is completed, the resulting casting body is allowed to stand for 15 minutes to form the epoxy resin casting body so as to obtain a high-voltage damping resistor. Pouring at low temperature.

Example 4.

A manufacturing process of a high-voltage damping resistor in this embodiment includes the following steps:

Step 1. Preheat the vacuum casting tank to 92°C, preheat the mixing container to 78°C, weigh 95 parts of epoxy resin, 43 parts of curing agent, 20 parts of toughening agent and 260 parts of filler, and add appropriate amount Accelerator, then mix the above raw materials evenly and preheat to 48°C, so that the container and raw materials are in a preheated state, and prevent the problem of uneven heating or overheating of raw materials during the preparation process;

Step 2. Pour the preheated raw materials into the mixing container, then heat the mixing container to 67°C and vacuumize it. Stir and degas the mixing material in the mixing container for 2.1 hours to discharge the raw material bubbles;

Step 3: Place the resistance band and heat dissipation pipe in the damping resistor in the mold used to form the epoxy resin casting body, put the mold into the vacuum casting tank, and keep the temperature of the vacuum casting tank at 75°C , the mixed material is injected into the mold in the vacuum casting tank body, after the casting is completed, the resulting casting body is allowed to stand for 12 minutes to form the epoxy resin casting body so as to obtain a high-voltage damping resistor. Pouring at low temperature.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than limiting the protection scope of the present invention, although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand , the technical solution of the present invention may be modified or equivalently replaced without departing from the spirit and scope of the technical solution of the present invention.

Claims (10)

1. A high-voltage damping resistor, characterized in that: comprising a resistance band, the resistance band is coated by a heat-conducting coating, both ends of the resistance band stretch out from the heat-conducting coating, and the heat-conducting band A heat dissipation pipe is inserted into the covering body, and the nozzle of the heat dissipation pipe leads to the heat conducting covering body. 2. A high-voltage damping resistor according to claim 1, characterized in that: the heat-conducting covering body is an epoxy resin casting body. 3. A high-voltage damping resistor according to claim 1, characterized in that: the bottom of the heat-conducting covering body is provided with a supporting bracket. 4. A high-voltage damping resistor according to claim 3, characterized in that: the support bracket includes a bottom plate, an insulator arranged below the bottom plate for supporting the bottom plate, and the epoxy resin cast The body is fixed on the base plate. 5. A high-voltage damping resistor according to claim 4, characterized in that: the bottom plate comprises a flat plate, and the opposite edge of the flat plate is provided with a limit side for limiting the position of the epoxy resin cast body plate. 6. A high-voltage damping resistor according to claim 1, characterized in that: the resistance strip located in the heat-conducting envelope is curved. 7. A high voltage damping resistor according to claim 6, characterized in that: there are eight heat dissipation pipes, and the eight heat dissipation pipes are evenly distributed on the outer periphery of the resistance band. 8 . The high-voltage damping resistor according to claim 1 , wherein the heat-conducting covering body is a rectangular parallelepiped, and the two ends of the resistance band protrude from opposite surfaces of the rectangular parallelepiped. 9. A high-voltage damping resistor according to claim 2, characterized in that: the epoxy resin casting body is made of the following components by weight: 90-100 parts of epoxy resin, 45-55 parts of cured Agent, 15-25 parts of toughening agent, 220-280 parts of filler. 10. The manufacturing process of the high-voltage damping resistor according to claim 9, characterized in that: comprising the following steps: Step 1. Preheat the vacuum casting tank to 90-94°C, preheat the mixing container to 76-80°C, weigh epoxy resin, curing agent, toughening agent and filler according to the formula, and then mix the raw materials And preheat to 46 ~ 50 ℃; Step 2. Inject the preheated raw materials into the mixing container, heat the mixing container to 65-70°C and vacuumize it, and stir and degas the mixing material in the mixing container for 2-2.5 hours; Step 3, place the resistance band and the heat dissipation pipe in a mold for forming the epoxy resin casting body, put the mold into the vacuum casting tank, and inject the mixture into the mold in the vacuum casting tank , the temperature of the vacuum casting tank is kept at 70-80° C., the mixed material is injected into the mold in the vacuum casting tank body, and the obtained casting body is left standing for 10-15 minutes to obtain a high-voltage damping resistor.