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

Abstract

The embodiment of the utility model 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 isolating switch, a copper bar, a copper bar, a wire outlet sleeve and a circuit breaker are arranged in the gas box, and dry gas is filled in the gas box. 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. According to the utility model, 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] This utility model relates to the field of switchgear, and in particular to an environmentally friendly gas-insulated AC metal-enclosed ring network switchgear. Background Technology

[0002] In recent years, some European countries have gradually begun to ban SF6 gas. Furthermore, with the progress made by some large foreign companies in researching SF6 alternatives applicable to high-voltage GIS products, the elimination of SF6 from power transmission and distribution products has become increasingly possible. Because SF6 has 2.5 times the insulation strength of nitrogen at the same pressure, 100 times the arc-extinguishing capacity of air, and 2.3 times the breakdown strength of air in a uniform electric field, maintaining the original SF6-insulated C-GIS switchgear structure and dimensions while simply replacing the gas to meet insulation requirements is extremely difficult.

[0003] Currently, if dry gas is directly used to replace SF6 gas in switchgear on the domestic market, partial discharge may occur. Existing designs mainly address this issue by increasing the phase spacing and ground spacing, but this approach results in a very large gas tank volume, which cannot meet application requirements. Utility Model Content

[0004] The technical problem to be solved by this utility model embodiment 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 ground, and reduce the gas box volume.

[0005] To address the aforementioned technical problems, this utility model provides an environmentally friendly gas-insulated AC metal-enclosed ring network switchgear, comprising a gas box, an instrument compartment, a mechanism compartment, and a cable compartment. The gas box contains a three-position disconnect switch, copper busbars, copper rods, outgoing bushings, and a circuit breaker. The gas box is filled with a pre-set dry gas. Pressure rings are provided at the connection points between the copper busbars and the circuit breaker, the isolating blades of the three-position disconnect switch, and the connections between the copper rods and the lower outgoing bushings and the three-position disconnect switch. The surface of the pressure rings is covered with a sulfide layer.

[0006] Furthermore, the maximum allowable electric field strength on the surface of the pressure ring satisfies the following equation:

[0007] ;

[0008] in, Let be the maximum allowable electric field intensity on the surface of the pressure ring, k be a proportionality constant, U be the potential difference between the point of maximum electric field intensity and the low potential of the pressure ring, and P be the geometric characteristic coefficient of the pressure ring. r is the radius of the pressure ring, d is the minimum net distance between the point of maximum electric field intensity and the low potential of the pressure ring; α is the first correction coefficient. is the dielectric constant of the dry gas; ζ is the relative permittivity of the material of the pressure ring, and ζ is the thickness of the sulfide layer on the surface of the pressure ring.

[0009] Furthermore, α = 1.19.

[0010] Furthermore, insulating skirts are provided at the connection points between the copper busbar and the circuit breaker, and the maximum allowable electric field strength on the surface of the skirts satisfies the following formula:

[0011] / β ;

[0012] E represents the maximum allowable electric field strength on the surface of the umbrella skirt. x E y E z , , respectively, represent the tangential electric fields in the x, y, and z directions at the connection between the copper busbar and the circuit breaker, and β is the second correction coefficient.

[0013] Furthermore, β = 1.53.

[0014] Furthermore, the preset drying gas is dry air.

[0015] The beneficial effects of this utility model are as follows: This utility model optimizes the electrode shape, reduces the electric field strength, avoids extremely non-uniform electric fields, improves the electric field distribution, and strictly controls partial discharge by designing the pressure ring, thereby optimizing the electric field distribution, reducing the phase spacing and the distance to ground, and effectively reducing the volume of the gas box without affecting the performance. Attached Figure Description

[0016] Figure 1 This is a side view of an environmentally friendly gas-insulated AC metal-enclosed ring network switchgear according to an embodiment of this utility model.

[0017] Figure 2 This is an internal structural diagram of the air box according to an embodiment of the present invention.

[0018] Explanation of icon numbers

[0019] Gas box 10, three-position disconnect switch 11, copper busbar 12, copper rod 13, outgoing bushing 14, circuit breaker 15, pressure ring 16, umbrella skirt 17, instrument room 20, mechanism room 30, cable room 40. Detailed Implementation

[0020] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of this application can be combined with each other. The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] In this embodiment of the invention, directional indicators (such as up, down, left, right, front, back, etc.) are only used to explain the relative positional relationship and movement of the components in a specific posture (as shown in the attached figure). If the specific posture changes, the directional indicators will also change accordingly.

[0022] Furthermore, in this utility model, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features.

[0023] Please refer to Figures 1-2 The environmentally friendly gas-insulated AC metal-enclosed ring network switchgear of this utility model embodiment includes a gas box, an instrument compartment, a mechanism compartment, and a cable compartment. The gas box, instrument compartment, mechanism compartment, and cable compartment are existing mechanisms.

[0024] The gas chamber contains a three-position disconnect switch, copper busbars, copper rods, outgoing bushings, and a circuit breaker, which is part of the existing design. The gas chamber is filled with a pre-set dry gas. The pre-set dry gas is dry air, composed of 79% N2 and 21% O2. This invention uses a dry gas with a slight positive pressure of 0.14 MPa as the main insulating medium, reducing gas consumption and resulting in lower absolute pressure and enhanced safety.

[0025] Pressure rings are provided at the connections between the copper busbar and the circuit breaker, at the isolating blade of the three-position disconnector, and at the connections between the copper rod and the lower outgoing bushing and the three-position disconnector. A sulfide layer is provided on the surface of the pressure rings. This invention adds a sulfide layer as an insulating layer, which is equivalent to increasing the insulation distance between conductors, compensating for the loss of clearance due to the addition of the shielding cover.

[0026] As one implementation method, the maximum allowable electric field strength on the surface of the pressure ring satisfies the following equation:

[0027] ;

[0028] in, Let be the maximum allowable electric field intensity on the surface of the pressure ring, k be a proportionality constant (a correction parameter that can be obtained by correcting actual results), U be the potential difference between the point of maximum electric field intensity and the low potential of the pressure ring, and P be the geometric characteristic coefficient of the pressure ring. r is the radius of the pressure ring, d is the minimum net distance between the point of maximum electric field intensity and the low potential of the pressure ring; α is the first correction coefficient. is the dielectric constant of the dry gas; Let ζ be the relative permittivity of the material of the pressure ring, and ζ be the thickness of the sulfide layer on the surface of the pressure ring. In practice, the shape of the pressure ring can be continuously adjusted by the above formula, and the results can be substituted into the formula to determine whether the modification direction is reasonable (if the electric field value increases after the next shape change, it means that the modification is unreasonable).

[0029] In one implementation, α = 1.19.

[0030] As one implementation method, insulating skirts are provided at the connection points between the copper busbar and the circuit breaker. The maximum allowable electric field strength on the surface of the skirts satisfies the following formula:

[0031] / β ;

[0032] E represents the maximum allowable electric field strength on the surface of the umbrella skirt. x E y E z Here, ∠x, ∠y, and ∠z represent the tangential electric fields in the x, y, and z directions at the connection point between the copper busbar and the circuit breaker, and β is the second correction coefficient. In practical implementation, the discharge path of the conductor can be blocked by continuously adjusting the sheds using the above formula, preventing the high-potential conductor at this point from directly discharging to the nearest low-potential conductor.

[0033] As one implementation method, β=1.53.

[0034] This invention uses the shielding of the umbrella skirt to improve the electric field and reduce the field strength.

[0035] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which 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 compartment, a mechanism compartment, and a cable compartment, wherein the gas box contains a three-position disconnect switch, copper busbars, copper rods, outgoing bushings, and a circuit breaker, characterized in that, The gas box is filled with a 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 disconnect switch, and the connection between the copper rod and the lower outgoing bushing and the three-position disconnect switch. The surface of the pressure ring is covered with a sulfide layer.

2. The environmentally friendly gas-insulated AC metal-enclosed ring network switchgear as described in claim 1, characterized in that, The maximum allowable electric field strength on the surface of the pressure ring must satisfy the following formula: ； in, Let be the maximum allowable electric field intensity on the surface of the pressure ring, k be a proportionality constant, U be the potential difference between the point of maximum electric field intensity and the low potential of the pressure ring, and P be the geometric characteristic coefficient of the pressure ring. r is the radius of the pressure ring, d is the minimum net distance between the point of maximum electric field intensity and the low potential of the pressure ring; α is the first correction coefficient. is the dielectric constant of the dry gas; ζ is the relative permittivity 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 as described in claim 2, characterized in that, α=1.19。 4. The environmentally friendly gas-insulated AC metal-enclosed ring network switchgear as described in claim 2, characterized in that, Insulating skirts are provided at the connection points between the copper busbar and the circuit breaker. The maximum allowable electric field strength on the surface of the skirts satisfies the following formula: / β ； E represents the maximum allowable electric field strength on the surface of the umbrella skirt. x E y E z , , respectively, represent the tangential electric fields in the x, y, and z 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 as described in claim 4, characterized in that, β=1.53。 6. The environmentally friendly gas-insulated AC metal-enclosed ring network switchgear as described in claim 1, characterized in that, The preset drying gas is dry air.

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