Grounding handcart interlocking device of switch cabinet
By adopting an electrical interlocking circuit design in high-voltage switchgear, the problems of misjudgment and low efficiency in grounding trolley operation are solved, thereby improving safety and efficiency and avoiding power accidents caused by misoperation. This design is suitable for grounding trolley interlocking devices in high-voltage switchgear.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- XI AN BAOGUANG INTELLIGENT ELECTRIC CO LTD
- Filing Date
- 2025-06-24
- Publication Date
- 2026-06-19
AI Technical Summary
The operation of grounding trolleys for existing high-voltage switchgear suffers from problems such as manual confirmation errors and low efficiency, resulting in insufficient safety and maintenance efficiency, especially when multiple switchgears are being maintained in a coordinated manner, and reliability is reduced in harsh environments.
The electrical interlocking design employs a first interlocking circuit and a second interlocking circuit to ensure that the grounding trolley can only be pushed into the working position when all switchgear trolleys are in the test position and the busbar is de-energized. The design of miniature circuit breakers, parallel connection points, and dual redundant lines prevents misoperation and single-point failures from affecting the interlocking function.
It effectively avoids dangers such as short circuits and electric arcs caused by misoperation, eliminates safety accidents, improves maintenance efficiency, reduces manpower input and operation and maintenance costs, and ensures stable operation of the system in harsh environments.
Smart Images
Figure CN224384895U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of high-voltage switch technology, specifically to a grounding handcart interlocking device for a switchgear. Background Technology
[0002] In the daily maintenance of high-voltage switchgear, the safe operation of the grounding trolley is a crucial link in ensuring the stable operation of the power system and the safety of personnel. Currently, the industry generally uses manual verification to determine the operating conditions of the grounding trolley: before maintenance, staff must check one by one whether all switchgear trolleys are in the test position and confirm that the busbar equipment is completely de-energized. Only after all conditions are manually verified to be correct can the grounding trolley be pushed into the working position. However, this traditional operating mode has significant drawbacks: on the one hand, the accuracy and efficiency of manual operation are highly dependent on the professional skills and working conditions of the personnel. Once negligence occurs (such as missing a check or misjudging the position of a switchgear trolley), it is very easy to cause serious misoperation accidents such as pushing the grounding trolley into the working position while it is energized, leading to short circuits in the power system and seriously threatening equipment safety and personnel lives. On the other hand, when multiple switchgears are being maintained in a coordinated manner, the manual verification process for each switchgear is cumbersome and consumes a lot of time and manpower. Especially in the scenario of batch maintenance in large substations, the workload increases dramatically and efficiency is low. Furthermore, traditional operations lack a mandatory constraint mechanism, making it difficult to avoid human error; and in harsh environments such as humidity and high temperatures, the reliability of manual inspections is further reduced, while existing electrical wiring, lacking protective measures, is prone to short circuits and unstable signal transmission, further exacerbating safety risks.
[0003] With the increasing demand for intelligent and unmanned operation and maintenance of power systems, there is an urgent need for a grounding handcart interlocking device for switchgear that can reduce human error and improve maintenance efficiency and safety compared to the traditional manual confirmation mode. Utility Model Content
[0004] The purpose of this utility model is to provide a grounding handcart interlocking device for switchgear to overcome the shortcomings of the prior art.
[0005] To achieve the above objectives, the present invention provides the following technical solution:
[0006] A grounding trolley interlocking device for a switchgear includes a first interlocking circuit and a second interlocking circuit. The first interlocking circuit is installed in the PT cabinet and includes a small busbar KM on the top of the cabinet. The positive terminal of the small busbar KM is sequentially connected to a first miniature circuit breaker 3DK, a grounding trolley non-working position 1S9, and the positive terminal of the signal busbar BSM. The negative terminal of the small busbar KM is sequentially connected to the negative terminal of the first miniature circuit breaker 3DK and the signal busbar BSM. The second interlocking circuit is installed inside the switchgear cabinet.
[0007] Furthermore, the second interlocking circuit includes a small busbar KM on the top of the cabinet, the positive terminal of which is sequentially connected to the second miniature circuit breaker 4DK, the test contact S8 of the switchgear truck, the non-energized contact KZQ of the truck, the grounding truck interlocking electromagnet CZ, the second miniature circuit breaker 4DK, and the negative terminal of the small busbar KM on the top of the cabinet.
[0008] Furthermore, the non-working position 1S9 of the grounding handcart is composed of multiple units connected in parallel.
[0009] Furthermore, the grounding handcart in non-working position 1S9 consists of two parallel connections.
[0010] Furthermore, the first miniature circuit breaker 3DK is a high breaking capacity miniature circuit breaker with short-circuit protection and overload protection functions, with a rated current of 10A and a breaking capacity of not less than 6kA.
[0011] Furthermore, the signal busbar is made of brass rod with the same length as the PT cabinet width and a diameter of not less than 6mm.
[0012] Furthermore, the other switchgear trolley test contact S8 is a normally closed contact, which remains closed when the switchgear trolley is in the test position.
[0013] Furthermore, the grounding handcart locking electromagnet CZ is a DC electromagnet.
[0014] Furthermore, a heat-shrink sleeve is fitted onto the surface of the small busbar KM on the top of the cabinet.
[0015] Furthermore, the multiple parallel grounding handcarts in non-working positions 1S9 are connected to the signal busbar via the small busbar KM on the top of the cabinet.
[0016] Compared with the prior art, the present invention has the following beneficial technical effects:
[0017] This utility model provides a grounding handcart interlocking device for switchgear. Through electrical interlocking between the first and second interlocking circuits, the grounding handcart can only be pushed into the working position when all switchgear handcarts are in the test position and the busbar is de-energized. This avoids the risk of personnel forcibly operating the grounding handcart when conditions are not met due to negligence or misjudgment, preventing dangers such as short circuits and electric arcs, and eliminating safety accidents such as electric shock and burns caused by misoperation.
[0018] Specifically, if any switchgear trolley is not in the correct position and the trolley busbar is energized, the grounding trolley locking electromagnet will not be energized, and the mechanical locking mechanism will prevent it from entering the working position. At the same time, when the grounding trolley is working, other switchgear will also receive a signal to prohibit closing, fundamentally eliminating the possibility of malicious misoperations such as "closing the grounding switch with the grounding switch on" or "closing the grounding switch with the power on," thus avoiding power accidents.
[0019] Furthermore, this utility model adopts a design of miniature circuit breaker, parallel connection point, and dual redundant line. Even if a component fails, such as poor contact at the non-working position of the grounding handcart or damage to a signal transmission line, the system can still work normally, ensuring the interlocking function is stable and reliable, and the safety mechanism will not fail due to a single point of failure.
[0020] Furthermore, there is no need for staff to check the position of each switch cabinet trolley one by one. By simply observing the status indicators of this utility model, it is possible to quickly determine whether the operating conditions are met, which greatly shortens the preparation time before maintenance, reduces manpower input, and lowers operation and maintenance costs. Attached Figure Description
[0021] Figure 1 This is a schematic diagram of the grounding handcart's non-working position interlock in an embodiment of this utility model.
[0022] Figure 2 This is a schematic diagram of the grounding handcart working position interlock in an embodiment of this utility model.
[0023] In the diagram, KM is the small busbar on the top of the cabinet; 3DK is the first miniature circuit breaker; 1S9 is the non-working position of the grounding trolley; BSM is the small signal busbar; 4DK is the second miniature circuit breaker; S8 is the test contact of other switchgear trolleys; KZQ is the non-energized contact of the trolley; and CZ is the grounding trolley interlocking electromagnet. Detailed Implementation
[0024] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.
[0025] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.
[0026] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.
[0027] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.
[0028] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.
[0029] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.
[0030] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.
[0031] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.
[0032] The accompanying drawings show various structural schematic diagrams according to embodiments of the present invention. These drawings are not to scale, and some details have been enlarged and may have been omitted for clarity. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.
[0033] See Figures 1 to 2 This utility model provides a grounding handcart interlocking device for a switchgear, including a small busbar KM on the top of the cabinet, a first miniature circuit breaker 3DK, a non-working position 1S9 for the grounding handcart, a signal busbar BSM, a second miniature circuit breaker 4DK, other switchgear handcart test contacts S8, a handcart non-energized contact KZQ, and a grounding handcart interlocking electromagnet CZ.
[0034] A grounding trolley interlocking device for a switchgear includes a first interlocking circuit and a second interlocking circuit. The first interlocking circuit is installed inside the PT cabinet and includes a small busbar KM at the top of the cabinet. The positive terminal of the small busbar KM is sequentially connected to a first miniature circuit breaker 3DK, a grounding trolley non-working position 1S9, and the positive terminal of the signal busbar BSM. The negative terminal of the small busbar KM is sequentially connected to the first miniature circuit breaker 3DK and the negative terminal of the signal busbar BSM. The second interlocking circuit is installed inside the switchgear cabinet. In this embodiment, two grounding trolley non-working positions 1S9 are connected in parallel.
[0035] The second interlocking circuit includes the cabinet top busbar KM. The positive terminal of the cabinet top busbar KM is connected in sequence to the second miniature circuit breaker 4DK, the test contact S8 of the other switch cabinet trolley, the non-energized contact KZQ of the trolley, the grounding trolley interlocking electromagnet CZ, the second miniature circuit breaker 4DK, and the negative terminal of the cabinet top busbar KM.
[0036] When the grounding trolley is in a non-working position, such as in the maintenance position or when it is removed from the cabinet, the grounding trolley non-working position contact 1S9 closes. At this time, the signal busbar BSM in the first interlocking circuit introduces positive and negative power through the first miniature circuit breaker 3DK. The current transmits the signal that the grounding trolley is in a non-working position to all switchgear through the closed grounding trolley non-working position contact 1S9. At this time, all switchgear receives the status signal that the grounding trolley is in a non-working position through the signal busbar. After receiving this signal, other switchgear confirms that the grounding trolley is not in operation, meets the closing safety conditions, and can perform normal closing and opening operations.
[0037] In the second interlocking circuit, the test contact S8 of the other switchgear trolleys is a normally closed contact. That is, when all switchgear trolleys are in the test position, the test contact S8 of the other switchgear trolleys remains closed. The test contact S8 of the other switchgear trolleys is connected to the unenergized contact KZQ of the trolley. When the busbar is de-energized, the unenergized contact KZQ of the trolley is closed. The small busbar KM on the top of the cabinet in the second interlocking circuit transmits power to the grounding trolley interlocking electromagnet CZ through the second miniature circuit breaker 4D. The grounding trolley interlocking electromagnet CZ is only energized when both the test contact S8 of the other switchgear trolleys and the unenergized contact KZQ of the trolley are closed.
[0038] If the test contacts S8 of other switchgear trolleys and the non-energized contact KZQ of the trolley are all closed, then the positive terminal of the small busbar KM on the top of the cabinet, the second miniature circuit breaker 4DK, the test contacts S8 of other switchgear trolleys, the non-energized contact KZQ of the trolley, the grounding trolley locking electromagnet CZ, the second miniature circuit breaker 4DK, and the negative terminal of the small busbar KM on the top of the cabinet form a closed circuit; then the grounding trolley locking electromagnet CZ is energized, releasing the mechanical lock of the grounding trolley and allowing the grounding trolley to enter the working position.
[0039] The first interlocking circuit of this invention ensures that other switchgear can be safely closed when the grounding trolley is not in operation, while preventing accidental closing when the grounding trolley is in operation, thus avoiding short circuit accidents caused by live grounding. The second interlocking circuit ensures that the grounding trolley is allowed to operate when all other switchgear is in the test position and the busbar is not energized. The two circuits together form a closed loop.
[0040] In some preferred embodiments of this utility model, the non-working position 1S9 of the grounding handcart is multiple in parallel; the multiple parallel grounding handcart non-working positions 1S9 are connected to the signal busbar through the small busbar KM on the top of the cabinet.
[0041] In some preferred embodiments of this utility model, the first miniature circuit breaker 3DK is a high breaking capacity miniature circuit breaker with short-circuit protection and overload protection functions. Its rated current is 10A and its breaking capacity is not less than 6kA, which is used to ensure the electrical safety of the first blocking circuit.
[0042] In some preferred embodiments of this utility model, the signal busbar (BSM) is made of brass rods with the same length and width as the PT cabinet and a diameter of not less than 6mm, to ensure the stability and reliability of signal transmission in the non-working position of the grounding handcart.
[0043] In some preferred embodiments of this utility model, the grounding handcart locking electromagnet CZ is a DC electromagnet with a rated voltage of DC220V and a suction force of not less than 50N.
[0044] In some preferred embodiments of this utility model, the surface of the small busbar KM on the top of the cabinet is covered with a heat shrink sleeve, which can withstand environmental conditions of 95% humidity and temperature from -25°C to 55°C, and is suitable for the operation environment of the switchgear under different climatic conditions.
[0045] It should be noted that this utility model is used in certain special situations. During power operation, there may be situations where power outages are required for maintenance. In such cases, on-site personnel must ensure that all switchgear is de-energized before pushing the grounding trolley into the working position of the high-voltage switchgear. This is to ensure the safety of the construction workers and to prevent them from being electrocuted in an unknown situation, thus avoiding potential personal injury.
[0046] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.
Claims
1. A grounding handcart interlocking device for a switchgear, characterized in that, It includes a first interlocking circuit and a second interlocking circuit; the first interlocking circuit is located in the PT cabinet, and the first interlocking circuit includes a small busbar KM on the top of the cabinet, the positive terminal of the small busbar KM is sequentially connected to the first miniature circuit breaker 3DK, the grounding trolley non-working position 1S9, and the positive terminal of the signal busbar BSM; the negative terminal of the small busbar KM is sequentially connected to the first miniature circuit breaker 3DK and the negative terminal of the signal busbar BSM; the second interlocking circuit is located inside the switch cabinet.
2. The grounding handcart interlocking device for a switchgear according to claim 1, characterized in that, The second interlocking circuit includes a small busbar KM on the top of the cabinet. The positive terminal of the small busbar KM is connected in sequence to the second miniature circuit breaker 4DK, the test contact S8 of the switchgear truck, the non-energized contact KZQ of the truck, the grounding truck interlocking electromagnet CZ, the second miniature circuit breaker 4DK, and the negative terminal of the small busbar KM on the top of the cabinet.
3. The grounding handcart interlocking device for a switchgear according to claim 1, characterized in that, The non-working position 1S9 of the grounding handcart is composed of multiple parallel connections.
4. The grounding handcart interlocking device for a switchgear according to claim 1, characterized in that, The grounding handcart in the non-working position 1S9 consists of two parallel connections.
5. The grounding handcart interlocking device for a switchgear according to claim 1, characterized in that, The first miniature circuit breaker 3DK is a high breaking capacity miniature circuit breaker with short-circuit protection and overload protection functions. Its rated current is 10A and its breaking capacity is not less than 6kA.
6. The grounding handcart interlocking device for a switchgear according to claim 1, characterized in that, The signal busbar (BSM) is made of brass rods with the same length as the PT cabinet width and a diameter of not less than 6mm.
7. The grounding handcart interlocking device for a switchgear according to claim 2, characterized in that, The other switchgear trolley test contact S8 is a normally closed contact. When the switchgear trolley is in the test position, the contact remains closed.
8. The grounding handcart interlocking device for a switchgear according to claim 2, characterized in that, The grounding handcart locking electromagnet CZ is a DC electromagnet.
9. The grounding handcart interlocking device for a switchgear according to claim 2, characterized in that, The surface of the small busbar KM on the top of the cabinet is fitted with a heat shrink sleeve.
10. A grounding handcart interlocking device for a switchgear according to claim 3, characterized in that, The multiple parallel grounding handcarts in non-working positions 1S9 are connected to the signal busbar via the small busbar KM on the top of the cabinet.