Environment-friendly gas-insulated alternating-current metal closed looped network switchgear

Abstract

The embodiment of the invention discloses environment-friendly gas insulation alternating current metal closed looped network switch equipment which comprises a gas box, an instrument chamber, a mechanism chamber and a cable chamber, a three-position disconnecting switch, a copper bar, a copper bar, a wire outlet sleeve and a circuit breaker are arranged in the gas box, and the gas box is filled with dry gas. The connection part of the copper bar and the circuit breaker, the isolation knife of the three-position isolation switch, and the connection part of the copper bar and the lower outgoing line sleeve and the three-position isolation switch are respectively provided with a compression ring, and the surface of the compression ring is provided with a vulcanization layer. Through the design of the compression ring, the electrode shape is optimized, the electric field intensity is reduced, the uneven electric field of the electrode is avoided, the electric field distribution is improved, and the partial discharge is strictly controlled, so that the electric field distribution is optimized, the phase spacing and the ground spacing are reduced, and the volume of the gas tank is effectively reduced on the premise that the performance is not influenced.

Description

Technical Field

[0001] The invention relates to the field of switchgear, and in particular to an environmentally friendly gas-insulated AC metal-enclosed ring network switchgear. Background Art

[0002] Since the insulation strength of SF6 is 2.5 times that of nitrogen at the same pressure, the arc extinguishing ability is 100 times that of air, and the breakdown strength in a uniform electric field is 2.3 times that of air, it is very difficult to maintain the original SF6 insulated C-GIS switchgear structure and size and only replace the gas to meet the insulation requirements.

[0003] If the switchgear on the domestic market directly uses dry gas to replace SF6 gas, partial discharge will occur. The existing design mainly solves this problem by increasing the phase spacing and the distance to the ground, but this solution will make the gas box design very large and cannot meet the application requirements. Summary of the invention

[0004] The technical problem to be solved by the embodiments of the present invention is to provide an environmentally friendly gas-insulated AC metal-enclosed ring network switchgear to optimize the electric field distribution, reduce the phase spacing and the distance to the ground, and reduce the volume of the gas box.

[0005] In order to solve the above technical problems, an embodiment of the present invention proposes an environmentally friendly gas-insulated AC metal-enclosed ring network switch device, including a gas box, an instrument room, a mechanism room, and a cable room. The gas box is equipped with a three-position disconnector, a copper busbar, a copper rod, an outlet bushing, and a circuit breaker. The gas box is filled with a preset dry gas. The connection between the copper busbar and the circuit breaker, the isolating knife of the three-position disconnector, and the connection between the copper rod and the lower outlet bushing and the three-position disconnector are all provided with a pressure ring, and the surface of the pressure ring is provided with a vulcanized layer.

[0006] Furthermore, the maximum electric field strength allowed by the pressure ring surface satisfies the following formula: ; in, is the maximum allowable electric field strength on the surface of the pressure ring, k is the proportional constant, U is the potential difference between the maximum electric field strength point of the pressure ring and the low potential potential, P is the geometric characteristic coefficient of the pressure ring, , r is the radius of the pressure ring, d is the minimum clear distance between the point of maximum electric field strength of the pressure ring and the low potential; α is the first correction coefficient, is the dielectric constant of the dry gas; is the relative dielectric constant of the material of the pressure ring, and ζ is the thickness of the sulfide layer on the surface of the pressure ring.

[0007] Furthermore, α=1.19.

[0008] Furthermore, an insulating shed is provided outside the connection between the copper busbar and the circuit breaker, and the maximum electric field strength allowed on the surface of the shed satisfies the following formula: / β ; is the maximum allowable electric field strength on the shed surface, E x 、E y 、E z are the tangential electric fields in the xyz directions at the connection between the copper busbar and the circuit breaker, and β is the second correction coefficient.

[0009] Furthermore, β=1.53.

[0010] Furthermore, the preset drying gas is dry air.

[0011] The beneficial effects of the present invention are as follows: the present invention optimizes the electrode shape, reduces the electric field strength, avoids extremely uneven electric fields, improves the electric field distribution and strictly controls local discharge through the design of the pressure ring, thereby optimizing the electric field distribution, reducing the phase spacing and the distance to the ground, and effectively reducing the volume of the gas box without affecting the performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a side view of an environmentally friendly gas-insulated AC metal-enclosed ring network switchgear according to an embodiment of the present invention.

[0013] Figure 2 1 is a diagram showing the internal structure of an air box according to an embodiment of the present invention.

[0014] Description of Figure Numbers Gas box 10, three-position disconnector 11, copper busbar 12, copper rod 13, outlet bushing 14, circuit breaker 15, pressure ring 16, umbrella skirt 17, instrument room 20, mechanism room 30, cable room 40. DETAILED DESCRIPTION

[0015] It should be noted that, in the absence of conflict, the embodiments in the present application and the features in the embodiments may be combined with each other. The present invention is further described in detail below in conjunction with the drawings and specific embodiments.

[0016] In the embodiments of the present invention, if there are directional indications (such as up, down, left, right, front, back, etc.), they are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0017] In addition, in the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features.

[0018] Please refer to Figure 1-2 The environmentally friendly gas-insulated AC metal-enclosed ring network switchgear of the embodiment of the present invention comprises a gas box, an instrument room, a mechanism room, and a cable room. The gas box, the instrument room, the mechanism room, and the cable room are existing mechanisms.

[0019] The gas box is equipped with a three-position disconnector, copper busbar, copper rod, outlet bushing, and circuit breaker, which are the existing designs. The gas box is filled with a preset dry gas. The preset dry gas is dry air, which is composed of 79% N2+21% O2. The present invention uses 0.14MPa slightly positive pressure dry gas as the main insulating medium, which reduces the gas consumption, and the absolute pressure is lower, which is safer.

[0020] The connection between the copper bar and the circuit breaker, the isolating knife of the three-position isolating switch, and the connection between the copper rod and the lower outlet bushing and the three-position isolating switch are all provided with a pressure ring, and a sulfide layer is provided on the surface of the pressure ring. The invention adds a sulfide layer as an insulating layer, which is equivalent to increasing the insulation distance between the conductors and compensating for the net distance lost due to the addition of the shielding cover.

[0021] As an implementation method, the maximum electric field strength allowed by the pressure ring surface satisfies the following formula: ; in, is the maximum allowable electric field strength on the surface of the pressure ring, k is the proportional constant (the proportional constant is a correction parameter and can be obtained by correcting the actual result), U is the potential difference between the maximum electric field strength point of the pressure ring and the low potential potential, P is the geometric characteristic coefficient of the pressure ring, , r is the radius of the pressure ring, d is the minimum clear distance between the point of maximum electric field strength of the pressure ring and the low potential; α is the first correction coefficient, is the dielectric constant of the dry gas; is the relative dielectric constant of the material of the pressure ring, and ζ is the thickness of the sulfide layer on the surface of the pressure ring. In specific implementation, the shape of the pressure ring can be continuously adjusted by the above formula, and the calculation can be substituted into the formula to determine whether the modification direction is reasonable (if the field strength value increases after the next shape change, it means that the change is unreasonable).

[0022] As an implementation, α=1.19.

[0023] As an implementation method, an insulating shed is provided outside the connection between the copper busbar and the circuit breaker, and the maximum electric field strength allowed on the surface of the shed satisfies the following formula: / β ; is the maximum allowable electric field strength on the shed surface, E x 、E y 、E z are the tangential electric fields in the xyz directions at the connection between the copper busbar and the circuit breaker, and β is the second correction coefficient. In specific implementation, the shed skirt can be continuously adjusted by the above formula to block the discharge path of the conductor, so that the high-potential conductor here cannot discharge linearly to the low-potential conductor closest to it.

[0024] As an implementation, β=1.53.

[0025] The present invention achieves the purpose of improving the electric field and reducing the field strength through the shielding of the umbrella skirt.

[0026] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An environmentally friendly gas-insulated AC metal-enclosed ring network switchgear, comprising a gas box, an instrument room, a mechanism room, and a cable room, wherein a three-position isolating switch, a copper bus, a copper rod, an outlet bushing, and a circuit breaker are arranged in the gas box, characterized in that: The gas box is filled with preset dry gas. Pressure rings are provided at the connection between the copper busbar and the circuit breaker, the isolating knife of the three-position isolating switch, and the connection between the copper rod and the lower outlet bushing and the three-position isolating switch. The surface of the pressure ring is provided with a vulcanized layer.

2. The environmentally friendly gas-insulated AC metal-enclosed ring network switchgear according to claim 1, characterized in that: The maximum electric field strength allowed on the pressure ring surface satisfies the following formula: ； in, is the maximum allowable electric field strength on the surface of the pressure ring, k is the proportional constant, U is the potential difference between the maximum electric field strength point of the pressure ring and the low potential potential, P is the geometric characteristic coefficient of the pressure ring, , r is the radius of the pressure ring, d is the minimum clear distance between the point of maximum electric field strength of the pressure ring and the low potential; α is the first correction coefficient, is the dielectric constant of the dry gas; is the relative dielectric constant of the material of the pressure ring, and ζ is the thickness of the sulfide layer on the surface of the pressure ring.

3. The environmentally friendly gas-insulated AC metal-enclosed ring network switchgear according to claim 2, characterized in that: α=1.19。 4. The environmentally friendly gas-insulated AC metal-enclosed ring network switchgear according to claim 2, characterized in that: There are insulating sheds outside the connection between the copper busbar and the circuit breaker. The maximum electric field strength allowed on the shed surface satisfies the following formula: / β ； is the maximum allowable electric field strength on the shed surface, E x 、E y 、E z are the tangential electric fields in the xyz directions at the connection between the copper busbar and the circuit breaker, and β is the second correction coefficient.

5. The environmentally friendly gas-insulated AC metal-enclosed ring network switchgear according to claim 4, characterized in that: β=1.53。 6. The environmentally friendly gas-insulated AC metal-enclosed ring network switchgear according to claim 1, characterized in that: The preset drying gas is dry air.

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