L-type grounding switching switch of high-voltage switch cabinet and switching method

Abstract

The application provides an L-shaped grounding switching switch and a switching method of a high-voltage switch cabinet, the grounding switching switch comprises a transmission mechanism, an L-shaped knife switch, an insulating rod, a grounding porcelain support, a lightning arrester porcelain support, a current transformer and a knife switch clamp; the L-shaped knife switch is fixed on the insulating rod, the transmission mechanism drives the insulating rod to rotate, thereby driving the L-shaped knife switch to rotate, the L-shaped knife switch comprises two rotation angles, when the first rotation angle, one L-shaped end of the L-shaped knife switch is in contact with the current transformer through the knife switch clamp, and the other L-shaped end is in contact with the grounding porcelain support through the knife switch clamp; when the second rotation angle, one L-shaped end of the L-shaped knife switch is in contact with the lightning arrester porcelain support through the knife switch clamp, and the other L-shaped end is in contact with the current transformer through the knife switch clamp. The novel L-shaped grounding switching switch separates the lightning arrester and the high-voltage cable, avoids disassembling the lightning arrester lead during maintenance experiment, greatly improves the test efficiency and shortens the maintenance time.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of energy recovery and power generation, in particular to an L-shaped grounding switch of a high-voltage switch cabinet and a switching method. BACKGROUND

[0002] In a centrally-arranged high-voltage switch cabinet, a grounding switch is one of indispensable devices for ensuring the power-off maintenance of the equipment, and together constitutes a five-prevention interlocking protection of the high-voltage switch cabinet, the structure of which is shown in Figure 1 After the grounding switch is closed, the front and rear cabinet doors of the high-voltage switch cabinet are allowed to be opened, and the current transformer, the lightning arrester and the high-voltage cable are grounded. For a running substation, in order to ensure the safety of high-voltage equipment, the lightning arrester needs to be separated from other equipment for annual insulation test, which requires the disconnection of the lightning arrester lead, and the restoration after the test. The disconnection of the lead occupies three fourths of the time, and since the power-off maintenance time is short, the work efficiency of the maintenance is greatly restricted. SUMMARY

[0003] In order to solve the technical problems in the background art, the present application provides an L-shaped grounding switch of a high-voltage switch cabinet and a switching method. The novel L-shaped grounding switch separates the lightning arrester from the high-voltage cable, avoids the disconnection of the lightning arrester lead during the maintenance test, greatly improves the test efficiency and shortens the maintenance time.

[0004] In order to achieve the above-mentioned purposes, the present application adopts the following technical solutions:

[0005] An L-shaped grounding switch of a high-voltage switch cabinet comprises a transmission mechanism, an L-shaped knife switch, an insulating rod, a grounding porcelain support, a lightning arrester porcelain support, a current transformer and a knife switch clamp. The L-shaped knife switch is fixed on the insulating rod, the transmission mechanism drives the rotation of the insulating rod, thereby driving the rotation of the L-shaped knife switch. The L-shaped knife switch comprises two rotation angles. At the first rotation angle, one L end of the L-shaped knife switch is in contact with the current transformer through the knife switch clamp, and the other L end is in contact with the grounding porcelain support through the knife switch clamp. At the second rotation angle, one L end of the L-shaped knife switch is in contact with the lightning arrester porcelain support through the knife switch clamp, and the other L end is in contact with the current transformer through the knife switch clamp.

[0006] Further, the transmission mechanism comprises a transmission rod, a positioning pin, a crank arm and an angle adjusting rod. The transmission rod drives the 90-degree rotation of the L-shaped knife switch through the crank arm and the angle adjusting rod, and the rotation is positioned by the positioning pin after being rotated to the position.

[0007] Further, the insulating rod insulates the three-phase knife switches from each other and from the ground. The cross section of the insulating rod is a square four-rib structure. The four sides of the insulating rod are recessed at the fixing position of the L-shaped knife switch, so as to position the knife switch. The L-shaped knife switch is a copper conductor, which plays a role of a conductor connection.

[0008] Further, the switching method of the L-shaped grounding switching switch of the high-voltage switch cabinet has the bidirectional switching function and is divided into a grounding state and a running state; in the grounding state, the lightning arrester is disconnected from the current transformer and the external high-voltage cable; in the running state, the lightning arrester is connected with the cable through the knife switch, and the switching method comprises the following steps:

[0009] 1) in normal operation, the grounding switching switch is located in the running state, at this time, the lightning arrester is connected with the current transformer and the high-voltage cable through the L-shaped knife switch, and the equipment is protected from overvoltage;

[0010] 2) when maintenance is needed, the transmission mechanism is operated to switch the grounding switching switch to the grounding state, the cabinet door is opened, at this time, the lightning arrester is disconnected from other equipment, and insulation inspection and high-voltage leakage test of the lightning arrester can be performed without disassembling the lightning arrester lead;

[0011] 3) when the maintenance is completed, the transmission mechanism is operated to switch the grounding switching switch to the running state;

[0012] 4) the grounding state and the running state of the grounding switching switch are positioned by the transmission mechanism through the locking pin.

[0013] Compared with the prior art, the beneficial effects of the present application are:

[0014] 1) the L-shaped grounding switching switch of the present application separates the lightning arrester from the high-voltage cable and connects them through the L-shaped knife switch, in the grounding state, the lightning arrester is disconnected from the high-voltage cable, which facilitates lightning arrester detection, and the biggest feature of this switch is that the L-shaped knife switch body is insulated from the ground, and the L-shaped knife switch is operated by the transmission mechanism to rotate 90 degrees for switching.

[0015] 2) the grounding switching switch only needs to be switched to the grounding state, and insulation test and leakage test of the lightning arrester can be performed without disassembling the lightning arrester lead. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a traditional grounding switch structure diagram mentioned in the background art;

[0017] Figure 2 is a grounding state position diagram of the L-shaped grounding switching switch of the high-voltage switch cabinet of the present application;

[0018] Figure 3 is a running state position diagram of the L-shaped grounding switching switch of the high-voltage switch cabinet of the present application;

[0019] Figure 4 is a grounding state position side view of the L-shaped grounding switching switch of the high-voltage switch cabinet of the present application;

[0020] Figure 5 This is a structural diagram of the insulating rod of an L-shaped grounding switching device in a high-voltage switchgear according to the present invention.

[0021] Figure 6 This is a control diagram of an L-shaped grounding switching switch in a high-voltage switchgear according to the present invention.

[0022] In the diagram: 1-Metal grounding switch; 2-Grounding flexible wire; 3-Surge arrester; 4-Positioning pin; 5-Transmission rod; 6-Crank arm; 7-Angle adjustment rod; 8-Insulating rod; 9-L-type knife switch; 10-Grounding porcelain insulator support; 11-Grounding busbar; 12-Current transformer; 13-Knife switch clamp; 14-Surge arrester porcelain insulator support; 15-Busbar; 16-Fixing bolt hole. Detailed Implementation

[0023] The specific embodiments provided by the present invention will be described in detail below with reference to the accompanying drawings.

[0024] like Figures 2-5 As shown, an L-shaped grounding switch for a high-voltage switchgear includes a transmission mechanism, an L-shaped knife switch 9, an insulating rod 8, a grounding porcelain insulator support 10, a surge arrester porcelain insulator support 14, a current transformer 12, and a knife switch clamp 13. The L-shaped knife switch 9 is fixed on the insulating rod 8. The transmission mechanism drives the insulating rod 8 to rotate, thereby driving the L-shaped knife switch 9 to rotate. The L-shaped knife switch 9 has two rotation angles. At the first rotation angle, one L-end of the L-shaped knife switch 9 contacts the current transformer 12 through the knife switch clamp 13, and the other L-end contacts the grounding porcelain insulator support 10 through the knife switch clamp 13. At the second rotation angle, one L-end of the L-shaped knife switch 9 contacts the surge arrester porcelain insulator support 14 through the knife switch clamp 13, and the other L-end contacts the current transformer 12 through the knife switch clamp 13.

[0025] The transmission mechanism includes a transmission rod 5, a positioning pin 4, a crank arm 6, and an angle adjustment rod 7. The transmission rod 5 drives the L-shaped knife switch 9 to rotate 90 degrees through the crank arm 6 and the angle adjustment rod 7. After rotating into position, it is positioned by the positioning pin 4.

[0026] like Figure 5 As shown, the insulating rod 8 ensures insulation between the three-phase disconnectors and to ground. The cross-section of the insulating rod 8 is a square quadrangular structure. Grooves are made on all four sides of the insulating rod 8 at the fixing point of the L-shaped disconnector 9 to facilitate the positioning of the disconnector. The L-shaped disconnector 9 is a copper conductor and serves as a conductor connection.

[0027] The switching method of the L-type grounding switch in a high-voltage switchgear, wherein the grounding switch has a bidirectional switching function, divided into grounding state and operating state; in the grounding state, the surge arrester 3 is disconnected from the current transformer 12 and the external high-voltage cable; in the operating state, the surge arrester 3 is connected to the cable through the L-type knife switch 9, and the switching method includes the following:

[0028] 1) During normal operation, the grounding switch is in the running state. At this time, the surge arrester 3 is connected to the current transformer 12 and the high-voltage cable through the L-shaped knife switch 9 to protect the equipment from overvoltage.

[0029] 2) When maintenance is required, operate the transmission mechanism to switch the grounding switch to the grounding position and open the switch cabinet door. At this time, the surge arrester 3 is disconnected from other equipment, and the insulation inspection and high voltage leakage test of the surge arrester 3 can be carried out without disconnecting the leads of the surge arrester 3.

[0030] 3) After the maintenance is completed, operate the transmission mechanism to switch the grounding switch to the running position;

[0031] 4) The grounding status and operating status of the grounding switch are positioned by the locking pin 4 through the transmission mechanism.

[0032] like Figure 6 The diagram shows the control circuit of the L-type grounding switch. Before operating the L-type grounding switch, ensure the high-voltage circuit breaker trolley is in the test position, activate the unlocking button TA, energize the locking electromagnet YT, and simultaneously charge capacitor C, unlocking the positioning pin 4. After button TA returns to its original position, the electromagnet discharges through the capacitor for a delayed locking. Rotate the transmission rod 5 to the grounding state, causing the L-type disconnect switch 9 to rotate, grounding the high-voltage cable and current transformer 12. Simultaneously, the surge arrester 3 is disconnected from the high-voltage cable. After rotation to the correct position, it is locked by the positioning pin 4. If the disconnect switch does not rotate to the correct position, adjust the adjusting bolt on the crank arm 6 and tighten the nut after adjustment. When switching to the working state, unlock the positioning pin 4 and rotate the transmission rod 5 in the opposite direction to switch the switch to the working position. The L-type disconnect switch 9 disengages from the grounding porcelain insulator support 10, connecting the surge arrester 3 to the high-voltage cable. After reaching the correct position, it is locked by the positioning pin 4.

[0033] The L-type grounding switch of this invention separates the surge arrester 3 from the high-voltage cable, connecting them via an L-type disconnector 9. In the grounded state, the surge arrester 3 is disconnected from the high-voltage cable, facilitating surge arrester 3 testing. The most significant feature of this switch is that the L-type disconnector 9 itself is insulated from ground. A transmission mechanism operates the L-type disconnector 9 to rotate 90 degrees for switching. This grounding switch allows for insulation and leakage tests of the surge arrester 3 simply by switching the switch to the grounded state, without needing to disconnect the surge arrester leads.

[0034] The above examples are implemented on the premise of the technical solution of the present application, and detailed implementation modes and specific operation processes are given, but the protection scope of the present application is not limited to the above examples. The methods used in the above examples are all conventional methods unless otherwise specified.

Claims

1. A switching method for an L-type grounding changeover switch in a high-voltage switchgear, characterized in that, The grounding switching switch includes a transmission mechanism, an L-shaped knife switch, an insulating rod, a grounding porcelain insulator support, a surge arrester porcelain insulator support, a current transformer, and a knife switch clamp. The L-shaped knife switch is fixed on the insulating rod. The transmission mechanism drives the insulating rod to rotate, thereby driving the L-shaped knife switch to rotate. The L-shaped knife switch has two rotation angles. At the first rotation angle, one L-end of the L-shaped knife switch contacts the current transformer through the knife switch clamp, and the other L-end contacts the grounding porcelain insulator support through the knife switch clamp. At the second rotation angle, one L-end of the L-shaped knife switch contacts the surge arrester porcelain insulator support through the knife switch clamp, and the other L-end contacts the current transformer through the knife switch clamp. The grounding switch has a bidirectional switching function, divided into grounding state and operating state; in the grounding state, the surge arrester is disconnected from the current transformer and the external high-voltage cable. In operation, the surge arrester is connected to the cable via an L-shaped disconnect switch: 1) During normal operation, the grounding switch is in the running position. At this time, the surge arrester is connected to the current transformer and high-voltage cable through the L-type knife switch to protect the equipment from overvoltage. 2) When maintenance is required, operate the transmission mechanism to switch the grounding switch to the grounding position, open the switch cabinet door, and the surge arrester will be disconnected from other equipment. Insulation inspection and high voltage leakage test of the surge arrester can be carried out without disconnecting the surge arrester leads. 3) After the maintenance is completed, operate the transmission mechanism to switch the grounding switch to the running position; 4) The grounding status and operating status of the grounding switch are positioned by a locking pin through a transmission mechanism.

2. The switching method of the L-type grounding switch in a high-voltage switchgear according to claim 1, characterized in that, The transmission mechanism includes a transmission rod, a positioning pin, a crank arm, and an angle adjustment rod. The transmission rod drives the L-shaped knife switch to rotate 90 degrees through the crank arm and the angle adjustment rod. After rotating to the correct position, it is positioned by the positioning pin.

3. The switching method of the L-type grounding switch in a high-voltage switchgear according to claim 1, characterized in that, The insulating rod ensures insulation between the three-phase disconnect switches and to ground. The cross-section of the insulating rod is a square quadrangular structure. Grooves are made on all four sides of the insulating rod at the L-shaped disconnect switch fixing point to facilitate switch positioning. The L-shaped disconnect switch is a copper conductor and serves as a conductor connection.

Images