CN104113002B - A kind of high tension cable cross connection grounding system switching device - Google Patents

Abstract

The invention discloses a switching device for a high-voltage cable cross-interconnection grounding system, which includes protectors R1~R3, ammeters A1~A3, voltmeters V1~V3, air switches K1~K6 and terminals P11~P32; the beneficial effects are: : 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 live, and the defective grounding box can be isolated to ensure the safe operation of the maintenance personnel and realize the liveliness A new breakthrough in the inspection and maintenance of the cable grounding system; the present invention integrates an ammeter and a voltmeter inside, and after connecting with the cable grounding lead, the cable live detection can be carried out, and the current load can be visually analyzed through the data display of the ammeter and voltmeter during maintenance. Status; the present invention is small in size and easy to carry.

Description

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

technical field

The invention belongs to the technical field of cable grounding system maintenance and relates to a high-voltage cable cross-connection grounding system switching device.

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.

Contents of the invention

The technical problem to be solved by the present invention is to provide a high-voltage cable cross-interconnection grounding system switching device that can perform maintenance and replacement operations on the cable protection grounding box and the direct grounding box when the cable is charged.

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 present invention are: 1. The present invention has a built-in protector and grounding structure, and according to maintenance requirements, it is possible to safely switch between the cross-interconnection mode and the direct grounding mode through the isolating knife switch (one box for multiple purposes); 2. When the cable is electrified, the original cable grounding box can be replaced or repaired. This invention can be used as a temporary grounding device. By connecting with the cable grounding wire, the defective grounding box can be isolated to ensure the safe operation of the maintenance personnel and realize the maintenance of the live cable grounding system. New breakthrough; 3. The present invention integrates an ammeter and a voltmeter inside, and after being connected with the cable grounding lead, the live cable detection can be carried out, and the current load status can be visually analyzed through the data display of the ammeter and voltmeter during maintenance; 4 , The present invention is small in size and easy to carry.

Description of drawings

Fig. 1 is the circuit schematic diagram of the present invention.

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 description

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 present invention 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 invention is aimed at the high voltage cable 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, at first the air switch K1 ~ K3 of the present invention is disconnected, and the air switch K4 ~ K6 is closed to make it a cross interconnection mode; secondly, the ground wire of the present invention is connected to the earth; then the wiring 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 metal sheath lead-out line at the left end of the B-phase cable insulation joint Sheath lead-out line, connect P32 to the metal sheath lead-out line at the right end of the B-phase cable insulation joint; connect terminal P31 to the metal-sheath lead-out line at the left end of the C-phase cable insulation joint, and connect P12 to C-phase The metal sheath lead-out line at the right end of the 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 invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention are included in the protection scope of the present invention within.

Claims (2)

1. a kind of high tension cable cross connection grounding system switching device, it is characterised in that：Including protector R1 ~ R3, ammeter A1 ~ A3, voltmeter V1 ~ V3, air switch K1 ~ K6 and binding post P11 ~ P32；

The voltmeter V1 is connected between the binding post P11 and ground；Binding post P11 ammeters described in Jing successively A1, air switch K4 meet the binding post P12；The protector R1 is in parallel with air switch K1 to be followed by the ammeter A1 And the node and ground of air switch K4 between；

The voltmeter V2 is connected between the binding post P21 and ground；Binding post P21 ammeters described in Jing successively A2, air switch K5 meet the binding post P22；The protector R2 is in parallel with air switch K2 to be followed by the ammeter A2 And the node and ground of air switch K5 between；

The voltmeter V3 is connected between the binding post P31 and ground；Binding post P31 ammeters described in Jing successively A3, air switch K6 meet the binding post P32；The protector R3 is in parallel with air switch K3 to be followed by the ammeter A3 And the node and ground of air switch K6 between.

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