A PT cabinet arrangement for suppressing overvoltage of 10kV motor feeder cabinet

Abstract

The utility model belongs to the technical field of electrical equipment, concretely relates to a PT cabinet arrangement structure for inhibiting 10kV motor feeder cabinet overvoltage, the utility model discloses a suitable capacity capacitor is arranged in the PT cabinet of motor feeder cabinet side and is connected into the medium voltage system bus, can when motor feeder cabinet encounters thunder overvoltage situation, through capacitor reduces the steepness of thunder invasion wave, to protect motor vertical insulation, simultaneously through the reasonable arrangement of each element in PT cabinet, its overall structure is compact, and the operation is flexible, does not occupy the other cabinet body space of medium voltage system bus, and through the setting of capacitor, voltage transformer, lightning arrester, electrified indicating lamp etc. electrical components below handcart type isolator, can when PT cabinet electrical equipment overhauls, timely isolation equipment and power supply, form the obvious visible disconnecting point, to avoid the electrified condition of overhauls, effectively guarantee the safety of staff and equipment.

Description

Technical Field

[0001] This utility model belongs to the field of electrical equipment technology, specifically relating to a PT cabinet arrangement structure for suppressing overvoltage in a 10kV motor feeder cabinet. Background Technology

[0002] In the petrochemical industry, the power distribution system for some high-voltage motors in gas gathering stations is installed inside the compressor skid-mounted housing, with high-voltage transmission lines directly connected to the incoming power distribution cabinet of the skid-mounted housing. Extreme weather events such as severe lightning strikes can cause grid fluctuations, triggering the protection circuitry of the skid-mounted power supply lines to trip and resulting in insulation damage to the corresponding compressor motors in the skid-mounted housing.

[0003] Since lightning surges reach peak values ​​in the microsecond range, while the current skid-mounted power supply and distribution system's microprocessor-based protection instantaneous tripping time and circuit breaker tripping time are in the millisecond range, with a total tripping time of approximately 80 milliseconds, the microprocessor-based protection cannot clear the lightning current in time, which can easily cause instantaneous insulation breakdown of the compressor motor, seriously affecting equipment operation. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide a PT cabinet arrangement structure for suppressing overvoltage of 10kV motor feeder cabinet. The structure is compact, flexible in operation, convenient in maintenance, stable and reliable in use, and can effectively suppress the impact of power grid fluctuations caused by lightning weather on the motor feeder cabinet, thereby improving the lightning protection performance of the equipment.

[0005] The technical solution adopted by this utility model to solve the above-mentioned technical problems is as follows: A PT cabinet arrangement structure for suppressing overvoltage in a 10kV motor feeder cabinet, wherein the PT cabinet (voltage transformer cabinet) is arranged on the side of the 10kV motor feeder cabinet and both are connected to the medium voltage busbar, and the 10kV motor feeder cabinet is connected to the motor of a compressor device. The PT cabinet includes: cabinet body 11 and the following components installed inside: grounding capacitor 1, handcart-type disconnect switch 2, voltage transformer 3, grounding surge arrester 4, live indicator light 5, live sensor 6, fuse 7, and grounding busbar 8. The handcart-type disconnect switch 2 is installed in the middle of the cabinet 11. One end of the handcart-type disconnect switch 2 is connected to the medium-voltage busbar branch line 10 that passes through the cabinet through the contact box 9. The other end of the handcart-type disconnect switch 2 is connected to the grounding capacitor 1 installed at the bottom right side of the cabinet 11 and the voltage transformer 3, grounding arrester 4, and live indicator light 5 installed at the bottom left side of the cabinet 11. The grounding capacitor 1, voltage transformer 3, grounding arrester 4, and live indicator light 5 are all connected to the grounding busbar 8 installed at the bottom of the cabinet 11.

[0006] Preferably, a fuse 7 is provided between the handcart-type disconnect switch 2 and the voltage transformer 3, with one end of the fuse 7 connected to the handcart-type disconnect switch 2 and the other end connected to the voltage transformer 3.

[0007] Preferably, the handcart-type disconnect switch 2 is equipped with a live sensor 6 for monitoring the continuity of the switch circuit.

[0008] Preferably, the grounding surge arrester 4 and the live indicator light 5 are both installed at the bottom of the cabinet 11 on the lower left side of the handcart-type disconnect switch 2 and connected to the grounding busbar 8.

[0009] Preferably, the grounding surge arrester 4 is a zinc oxide surge arrester.

[0010] Preferably, the grounding capacitor 1 is installed at the bottom of the cabinet 11 on the lower right side of the handcart-type disconnect switch 2 and connected to the grounding busbar 8.

[0011] Preferably, a second surge arrester is installed on the grounding capacitor 1.

[0012] Preferably, a light is installed on the top of the cabinet 11, and a transparent observation window is provided on the cabinet door of the cabinet 11.

[0013] Compared with the prior art, the present invention has the following main advantages: 1. This utility model, by setting a capacitor of appropriate capacity in the PT cabinet next to the motor feeder cabinet and connecting it to the medium voltage system bus, can reduce the steepness of the lightning intrusion wave when the motor feeder cabinet encounters lightning overvoltage, thereby protecting the longitudinal insulation of the motor. 2. This utility model, through the reasonable arrangement of various components in the PT cabinet, has a compact overall structure and flexible operation. It does not occupy the space of other cabinets in the medium-voltage system busbar. Furthermore, by placing electrical components such as capacitors, voltage transformers, surge arresters, and live indicator lights below the handcart-type disconnect switch, it can promptly isolate the equipment from the power supply during the maintenance of the PT cabinet electrical equipment, forming a clearly visible disconnect point to avoid live maintenance and effectively protect the safety of personnel and equipment. Attached Figure Description

[0014] Figure 1 This is an overall schematic diagram of the PT cabinet layout structure in an embodiment of this utility model; Figure 2 This is a wiring diagram inside the PT cabinet in an embodiment of this utility model; Figure 3 This is a schematic diagram of the system inside the PT cabinet in an embodiment of this utility model.

[0015] In the diagram: 1-grounding capacitor, 2-handcart type disconnect switch, 3-voltage transformer, 4-grounding surge arrester, 5-live indicator light, 6-live sensor, 7-fuse, 8-grounding busbar, 9-contact box, 10-medium voltage busbar branch, 11-cabinet. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0017] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0018] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0019] In the description of this application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this application is in use. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0020] The features and performance of this application will be further described in detail below with reference to the embodiments.

[0021] Example 1: This example provides a PT cabinet arrangement structure for suppressing overvoltage in a 10kV motor feeder cabinet. The PT cabinet is arranged on the side of the 10kV motor feeder cabinet, and both are connected to the medium voltage busbar. The 10kV motor feeder cabinet is connected to the motor of a compressor device. like Figures 1-3 As shown, it mainly includes: cabinet 11 and the grounding capacitor 1, handcart-type disconnect switch 2, voltage transformer 3, grounding surge arrester 4, live indicator light 5, live sensor 6, fuse 7 and grounding busbar 8 installed inside it; The handcart-type disconnect switch 2 is installed in the middle of the cabinet 11. One end of the handcart-type disconnect switch 2 is connected to the medium-voltage busbar branch line 10 that passes through the cabinet through the contact box 9. The other end of the handcart-type disconnect switch 2 is connected to the grounding capacitor 1 installed at the bottom right side of the cabinet 11 and the voltage transformer 3, grounding arrester 4, and live indicator light 5 installed at the bottom left side of the cabinet 11. The grounding capacitor 1, voltage transformer 3, grounding arrester 4, and live indicator light 5 are all connected to the grounding busbar 8 installed at the bottom of the cabinet 11.

[0022] Furthermore, a fuse 7 is provided between the handcart-type disconnect switch 2 and the voltage transformer 3. One end of the fuse 7 is connected to the handcart-type disconnect switch 2, and the other end is connected to the voltage transformer 3.

[0023] Furthermore, the handcart-type disconnect switch 2 is equipped with a live sensor 6 for monitoring the continuity of the switch circuit.

[0024] Furthermore, the grounding surge arrester 4 and the live indicator light 5 are both installed at the bottom of the cabinet 11 on the lower left side of the handcart-type disconnect switch 2 and connected to the grounding busbar 8.

[0025] Furthermore, the grounding surge arrester 4 is specifically a zinc oxide surge arrester.

[0026] Furthermore, the grounding capacitor 1 is installed at the bottom of the cabinet 11 on the lower right side of the handcart-type disconnect switch 2 and connected to the grounding busbar 8.

[0027] Furthermore, a second surge arrester is installed on the grounding capacitor 1.

[0028] Furthermore, a light is installed on the top of the cabinet 11, and a transparent observation window is provided on the cabinet door of the cabinet 11.

[0029] Example 2: This example provides a PT cabinet arrangement structure for suppressing overvoltage in a 10kV motor feeder cabinet. The skid-mounted 10kV busbar incoming and outgoing cables have a cross-section of 3x70mm². 2 Considering the total length of the incoming and outgoing cables is 800m, the total capacitance of the skid-mounted incoming and outgoing circuit cables is approximately 0.216uF. Taking into account the single-phase grounding capacitance current, the capacitance including the cable section is taken as 1.5uF. The capacitor capacity is Q=C*0.314*U 2 = (1.5 - 0.216) * 0.314 * 10.5 2 kVar = 44.45kVar. Referring to the manufacturer's sample, the capacitor model selected is BMF-11-50-3 (1.444uF). The final capacitance including the cable section is 1.66uF. The single-phase grounding capacitor current is approximately Ic = 2π * 50 * 1.66 * 10⁻⁶.-6 *1.732*10.5*10 3 =9.47A.

[0030] Furthermore, the handcart-type disconnect switch 2 is installed above the grounding capacitor, voltage transformer, surge arrester, and live indicator. It is used to isolate the equipment under maintenance from the power supply during PT cabinet electrical equipment maintenance, forming a clearly visible disconnect point to ensure the safety of personnel and equipment.

[0031] Furthermore, the voltage transformer 3 is installed at the bottom of the PT cabinet below the isolation truck, providing a standard secondary voltage of 100V or 100 / 3V to secondary equipment such as measuring instruments and protection devices.

[0032] Furthermore, the surge arrester 4 is installed at the bottom of the PT cabinet below the isolation truck, and the surge arrester serves to reduce the peak voltage of the lightning surge.

[0033] Furthermore, all parts of this application that are not described in detail are the same as or implemented using existing technology.

[0034] In summary: 1. This utility model, by setting a capacitor of appropriate capacity in the PT cabinet next to the motor feeder cabinet and connecting it to the medium voltage system bus, can reduce the steepness of the lightning intrusion wave when the motor feeder cabinet encounters lightning overvoltage, thereby protecting the longitudinal insulation of the motor. 2. This utility model, through the reasonable arrangement of various components in the PT cabinet, has a compact overall structure and flexible operation. It does not occupy the space of other cabinets in the medium-voltage system busbar. Furthermore, by placing electrical components such as capacitors, voltage transformers, surge arresters, and live indicator lights below the handcart-type disconnect switch, it can promptly isolate the equipment from the power supply during the maintenance of the PT cabinet electrical equipment, forming a clearly visible disconnect point to avoid live maintenance and effectively protect the safety of personnel and equipment.

[0035] The above embodiments are only used to illustrate the design concept and features of this utility model, and their purpose is to enable those skilled in the art to understand the content of this utility model and implement it accordingly. The protection scope of this utility model is not limited to the above embodiments. Therefore, all equivalent changes or modifications made based on the principles and design ideas disclosed in this utility model are within the protection scope of this utility model.

Claims

1. A PT cabinet arrangement for suppressing overvoltage of a 10 kV motor feeder cabinet, the PT cabinet is arranged on one side of the 10 kV motor feeder cabinet, and the PT cabinet and the 10 kV motor feeder cabinet are connected with a medium voltage bus, characterized in that: Includes the cabinet (11) and the grounding capacitor (1) installed inside it, the handcart-type disconnect switch (2), the voltage transformer (3), the grounding surge arrester (4), the live indicator light (5), the live sensor (6), the fuse (7) and the grounding busbar (8); ​ The handcart-type disconnect switch (2) is installed in the middle of the cabinet (11). One end of the handcart-type disconnect switch (2) is connected to the medium-voltage busbar branch (10) that passes through the cabinet through the contact box (9). The other end of the handcart-type disconnect switch (2) is connected to the grounding capacitor (1) installed at the bottom right side of the cabinet (11) and the voltage transformer (3), grounding arrester (4), and live indicator light (5) installed at the bottom left side of the cabinet (11). The grounding capacitor (1), voltage transformer (3), grounding arrester (4), and live indicator light (5) are all connected to the grounding busbar (8) installed at the bottom of the cabinet (11).

2. A PT cabinet arrangement for suppressing overvoltage in a 10 kV motor feeder cabinet according to claim 1, characterized in that: A fuse (7) is provided between the handcart-type disconnect switch (2) and the voltage transformer (3). One end of the fuse (7) is connected to the handcart-type disconnect switch (2), and the other end is connected to the voltage transformer (3).

3. A PT cabinet arrangement for suppressing overvoltage in a 10 kV motor feeder cabinet according to claim 1, characterized in that: The handcart-type disconnect switch (2) is equipped with a live sensor (6) for monitoring the continuity of the switch circuit.

4. A PT cabinet arrangement for suppressing overvoltage in a 10 kV motor feeder cabinet according to claim 1, characterized in that: The grounding arrester (4) and the live indicator light (5) are both installed at the bottom of the cabinet (11) on the lower left side of the handcart-type disconnect switch (2) and connected to the grounding busbar (8).

5. A PT cabinet arrangement for suppressing overvoltage in a 10 kV motor feeder cabinet according to claim 4, characterized in that: The grounding surge arrester (4) is specifically a zinc oxide surge arrester.

6. A PT cabinet arrangement for suppressing overvoltage in a 10 kV motor feeder cabinet according to claim 1, characterized in that: The grounding capacitor (1) is installed at the bottom of the cabinet (11) below the right side of the handcart-type disconnect switch (2) and connected to the grounding busbar (8).

7. A PT cabinet arrangement for suppressing overvoltage in a 10 kV motor feeder cabinet according to claim 5, characterized in that: A second surge arrester is installed on the grounding capacitor (1).

8. A PT cabinet arrangement for suppressing overvoltage in a 10 kV motor feeder cabinet according to claim 1, characterized in that: The cabinet (11) is equipped with a lighting lamp on the top and a transparent observation window is provided on the cabinet door.

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