CN203895836U - Switching device of cross-connected high-voltage cable grounding system - Google Patents

Abstract

The utility model discloses a switching device for a high-voltage cable cross-interconnection grounding system, which comprises protectors R1~R3, ammeters A1~A3, voltmeters V1~V3, air switches K1~K6 and connection terminals P11~P32; and has beneficial effects Yes: The air switch can be used to safely switch between the cross-connection mode and the direct grounding mode; the original cable grounding box can be replaced or repaired when the cable is charged, and the defective grounding box can be isolated to ensure the safe operation of the maintenance personnel. A new breakthrough in the cable grounding system for live maintenance; the utility model integrates an ammeter and a voltmeter inside, and can carry out cable live detection after being connected with the cable grounding lead, and can visually analyze the current situation through the data display of the ammeter and voltmeter during maintenance. The load state; the utility model is small in size and easy to carry.

Description

A high-voltage cable cross-interconnection grounding system switching device

technical field

The utility model belongs to the technical field of cable grounding system maintenance, and relates to a switching device for a high-voltage cable cross-interconnection grounding system.

Background technique

The main function of the high-voltage cable protective grounding system is to reduce the induced voltage accumulated in the metal protective layer of the running cable, and to eliminate excess induced current through the grounding system. At present, single-core high-voltage cables mostly adopt single-point grounding mode, one-end grounding and one-end protection mode, and cross-connection mode. If there is a grounding system fault, the grounding system should be overhauled after the cable is powered off.

Cable grounding boxes are mostly used in 35kV and above cable grounding systems. Due to the poor sealing of the cable grounding boxes and the lack of strict control of the construction process, the faults of some cable grounding boxes have occurred frequently recently, resulting in forced power outages for maintenance of the power grid. Every power outage for maintenance will cause a single-line power outage in the power grid, which will cause great economic losses to users and cause transmission pressure to adjacent power grids. At the same time, the number of staff to cooperate with the power outage increases, including operation personnel for power outage switching operations, maintenance personnel to eliminate shortages, dispatchers to order, line personnel to maintain power, etc., which increases the workload and the loss of manpower and material resources.

Utility model content

The technical problem to be solved by the utility model is to provide a high-voltage cable cross-interconnection grounding system switching device that can repair and replace the cable protection grounding box and the direct grounding box when the cable is electrified.

The technical solution adopted to solve the above technical problems is: a high-voltage cable cross-connection grounding system switching device, including protectors R1~R3, ammeters A1~A3, voltmeters V1~V3, air switches K1~K6 and terminal blocks P11~P32;

The voltmeter V1 is connected between the terminal P11 and the ground; the terminal P11 is connected to the terminal P12 through the ammeter A1 and the air switch K4 in turn; after the protector R1 is connected in parallel with the air switch K1 Connected between the node of the ammeter A1 and the air switch K4 and ground;

The voltmeter V2 is connected between the terminal P21 and the ground; the terminal P21 is connected to the terminal P22 through the ammeter A2 and the air switch K5 in sequence; after the protector R2 is connected in parallel with the air switch K2 Connected between the node of the ammeter A2 and the air switch K5 and ground;

The voltmeter V3 is connected between the terminal P31 and the ground; the terminal P31 is connected to the terminal P32 through the ammeter A3 and the air switch K6 in sequence; after the protector R3 is connected in parallel with the air switch K3 It is connected between the node of the ammeter A3 and the air switch K6 and the ground.

The models of the protectors R1~R3 are all BHQ-10/400; the models of the ammeters A1~A3 are all AOB194Z-8×4-3U; the models of the voltmeters V1~V3 are all AOB194Z-8× 4-3U; the models of the air switches K1~K3 are all DZ20L-250/4300.

The beneficial effects of the utility model are: 1. The utility model has a built-in protector and a grounding structure. According to maintenance needs, the air switch can be used for safe switching between the cross-interconnection mode and the direct grounding mode (multi-purpose in one box); Replace or overhaul the original cable grounding box when the cable is charged. The utility model can be used as a temporary grounding device. By connecting with the cable grounding wire, the defective grounding box is isolated to ensure the safe operation of the maintenance personnel and realize the live maintenance cable grounding system. 3. The utility model integrates an ammeter and a voltmeter inside, and the live cable detection can be carried out after being connected with the cable grounding lead, and the current load status can be visually analyzed through the data display of the ammeter and voltmeter during maintenance. ; 4. The utility model is small in size and easy to carry.

Description of drawings

Fig. 1 is the circuit schematic diagram of the utility model.

Fig. 2 is a schematic diagram of the principle of live maintenance and monitoring in the cable cross-connection protection mode.

In Figure 2, AJT——A phase cable insulation joint; BJT——B phase cable insulation joint; CJT——C phase cable insulation joint; A——A phase cable; B——B phase cable; C——C Phase cables; JCHL—cross connection box; A-1, A-2, B-1, B-2, C-1, and C-2 are the terminals of the cross connection grounding box respectively.

Detailed ways

It can be known from the embodiment shown in Figure 1 that it includes protectors R1~R3, ammeters A1~A3, voltmeters V1~V3, air switches K1~K6 and terminals P11~P32;

The voltmeter V1 is connected between the terminal P11 and the ground; the terminal P11 is connected to the terminal P12 through the ammeter A1 and the air switch K4 in turn; after the protector R1 is connected in parallel with the air switch K1 Connected between the node of the ammeter A1 and the air switch K4 and ground;

The voltmeter V2 is connected between the terminal P21 and the ground; the terminal P21 is connected to the terminal P22 through the ammeter A2 and the air switch K5 in sequence; after the protector R2 is connected in parallel with the air switch K2 Connected between the node of the ammeter A2 and the air switch K5 and ground;

The voltmeter V3 is connected between the terminal P31 and the ground; the terminal P31 is connected to the terminal P32 through the ammeter A3 and the air switch K6 in sequence; after the protector R3 is connected in parallel with the air switch K3 It is connected between the node of the ammeter A3 and the air switch K6 and the ground.

The models of the protectors R1~R3 are all BHQ-10/400; the models of the ammeters A1~A3 are all AOB194Z-8×4-3U; the models of the voltmeters V1~V3 are all AOB194Z-8× 4-3U; the models of the air switches K1~K3 are all DZ20L-250/4300.

The working process of the utility model is as follows: the main function of the high-voltage cable protective grounding system is to reduce the induced voltage accumulated in the metal protective layer of the running cable, and to eliminate redundant induced current through the grounding system. At present, single-core high-voltage cables mostly adopt single-point grounding mode, one-end grounding and one-end protection mode, and cross-connection mode. If there is a fault in the protective grounding system of the high-voltage cable, the protective grounding system of the high-voltage cable should be overhauled after the cable is powered off. The utility model is aimed at the high-voltage cables under the protection mode of cable cross-interconnection.

As shown in Figure 2, A-1 of the cross-interconnection grounding box is connected to the metal sheath lead-out line at the left end of the A-phase cable insulation joint, and A-2 of the cross-interconnection grounding box is connected to the metal sheath lead-out line at the right end of the A-phase cable insulation joint Above; B-1 of the cross-interconnection grounding box is connected to the metal sheath lead-out line at the left end of the B-phase cable insulation joint, and B-2 of the cross-interconnection grounding box is connected to the metal sheath lead-out line at the right end of the B-phase cable insulation joint; cross-connection C-1 of the grounding box is connected to the metal sheath lead-out line at the left end of the C-phase cable insulation joint, and C-2 of the cross-connection grounding box is connected to the metal sheath lead-out line at the right end of the C-phase cable insulation joint.

If there is a defect in the cross-interconnection grounding box, live inspection is required. Before overhauling the cross interconnection grounding box, first disconnect the air switches K1~K3 of the present invention, and close the air switches K4~K6 to make it a cross interconnection mode; secondly, connect the ground wire of the present invention to the earth; then Connect terminal P11 to the metal sheath lead-out line at the left end of the A-phase cable insulation joint, connect P22 to the metal sheath lead-out line at the right end of the A-phase cable insulation joint; connect terminal P21 to the left end of the B-phase cable insulation joint Connect P32 to the metal sheath lead wire at the right end of the B-phase cable insulation joint; connect terminal P31 to the metal sheath lead wire at the left end of the C-phase cable insulation joint, and connect P12 to the The lead wire of the metal sheath at the right end of the C-phase cable insulation joint (see Figure 2).

After the connection is completed, the staff can disconnect the defective cross-connection grounding box from the cable. At this time, the cross-connection grounding box that needs to be repaired is isolated to make it safe for maintenance.

The above descriptions are only preferred embodiments of the present utility model, and are not intended to limit the present utility model. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present utility model are included in this utility model. within the scope of the new protection.

Claims (2)

1. the cross interconnected grounding system switching device of high-tension cable, is characterized in that: comprise protector R1 ~ R3, ammeter A1 ~ A3, voltmeter V1 ~ V3, air switch K1 ~ K6 and binding post P11 ~ P32;

Described voltmeter V1 is connected between described binding post P11 and ground; Described binding post P11 meets described binding post P12 through described ammeter A1, air switch K4 successively; After described protector R1 is in parallel with air switch K1, be connected between described ammeter A1 and the node and ground of air switch K4;

Described voltmeter V2 is connected between described binding post P21 and ground; Described binding post P21 meets described binding post P22 through described ammeter A2, air switch K5 successively; After described protector R2 is in parallel with air switch K2, be connected between described ammeter A2 and the node and ground of air switch K5;

Described voltmeter V3 is connected between described binding post P31 and ground; Described binding post P31 meets described binding post P32 through described ammeter A3, air switch K6 successively; After described protector R3 is in parallel with air switch K3, be connected between described ammeter A3 and the node and ground of air switch K6.

2. the cross interconnected grounding system switching device of a kind of high-tension cable according to claim 1, is characterized in that: the model of described protector R1 ~ R3 is BHQ-10/400; The model of described ammeter A1 ~ A3 is AOB194Z-8 × 4-3U; The model of described voltmeter V1 ~ V3 is AOB194Z-8 × 4-3U; The model of described air switch K1 ~ K3 is DZ20L-250/4300.