A modular bridge arm switchgear applied to a bridge arm type on-load voltage regulating device

Abstract

The utility model discloses a modularization bridge arm switch cabinet applied to bridge arm type on -load voltage regulating device. Modularization bridge arm switch cabinet includes cabinet body and a plurality of single -phase bridge arm switch module, each single -phase bridge arm switch module is side by side arrangement along the height direction of cabinet body, and is electrically connected with cabinet backplate busbar, single -phase bridge arm switch module is slidably connected with cabinet through plug -in guiding mechanism, single -phase bridge arm switch module includes module casing and sets up in module casing and is separated through the energy -taking mutual -induction unit of upper layer insulating partition and lower layer insulating partition, power device unit and control board card unit. The utility model discloses through the modularization design of single -phase bridge arm switch, and the plug -in assembly mode of each module and cabinet body, has simplified the internal layout and wiring relation of cabinet body of bridge arm type on -load voltage regulating device.

Description

Technical Field

[0001] This utility model belongs to the field of on-load tap changer technology for power equipment, specifically relating to a modular bridge arm switchgear used in bridge arm type on-load tap changers. Background Technology

[0002] The bridge-arm type on-load tap changer combines the different potentials of the multi-tap regulating winding through the upper and lower bridge arm switch groups, realizing multi-stage voltage regulation of the transformer under load. In practical engineering applications, the bridge-arm type on-load tap changer is usually installed in a complete equipment cabinet, with each bridge arm switch, transition switch, and its control circuit distributed inside the cabinet.

[0003] However, the above-mentioned distributed layout has the following drawbacks: Firstly, the wiring relationships between each bridge arm switch and its control circuit are complex. When a bridge arm switch or its control circuit fails, it is necessary to check and repair them one by one inside the cabinet, resulting in a large workload, long power outage time, and affecting the reliability of power supply. Secondly, the control boards of each bridge arm switch usually require external auxiliary power supply. The control power cables are introduced from outside the cabinet, increasing the wiring complexity inside the cabinet. Moreover, a failure of the external auxiliary power supply may cause the control board to lose power, affecting the normal control of the bridge arm switch.

[0004] Furthermore, power devices (such as thyristors) in the bridge arm switch generate heat during operation. In a distributed arrangement, the heat dissipation conditions of each power device are inconsistent, and some devices may overheat due to poor heat dissipation, affecting device lifespan and device reliability. In similar power equipment such as hybrid phase-shifting transformers, there are existing technical solutions that use parallel energy extraction windings to draw power locally from the main circuit to power the control module; however, this energy extraction method has not yet been integrated with the modular design of bridge arm on-load tap changers.

[0005] Therefore, it is necessary to provide a structural solution that integrates the bridge arm switch, local power source and control board into an independent module, so as to realize the modular design of the bridge arm switch assembly, simplify the internal wiring of the cabinet, and improve the convenience of maintenance and heat dissipation uniformity.

[0006] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this utility model, and therefore may include information that does not constitute prior art known to those skilled in the art. Utility Model Content

[0007] To address the aforementioned problems in the existing technology, this utility model provides a modular bridge arm switchgear for use in bridge arm type on-load tap changers. The technical problem to be solved by this utility model is achieved through the following technical solution: This utility model provides a modular bridge arm switchgear for use in bridge arm type on-load tap changers, comprising: The cabinet includes a front panel and a back panel that are arranged opposite to each other; a back panel busbar is provided on the back panel. Multiple single-phase bridge arm switch modules are arranged side by side along the height of the cabinet; each of the single-phase bridge arm switch modules is electrically connected to the busbar of the cabinet back panel. The cabinet interior is equipped with a plug-in guide mechanism for each single-phase bridge arm switch module, and each single-phase bridge arm switch module is slidably connected to the cabinet through the plug-in guide mechanism. The insertion and removal direction of the single-phase bridge arm switch module is perpendicular to both the front panel and the rear panel of the cabinet. The single-phase bridge arm switch module includes a module housing and, from top to bottom, a power inductor unit, a power device unit, and a control board unit arranged within the module housing. An upper insulating partition is provided between the power inductor unit and the power device unit, and a lower insulating partition is provided between the power device unit and the control board unit.

[0008] Compared with the prior art, the beneficial effects of this utility model are as follows: 1. This utility model achieves modular design of bridge arm switch components by encapsulating the power devices, local energy transformers, and control boards of a single-phase bridge arm switch in a single modular housing. Each module has the same structure and is interchangeable, simplifying the internal layout and wiring of the bridge arm on-load tap changer cabinet. At the same time, insulating partitions (upper and lower insulating partitions) are used to divide the interior of the single-phase bridge arm switch module into three areas, which respectively house the energy transformer unit, the power device unit, and the control board unit. The electrical and thermal isolation between each layer is clear, and the structure is clear, which helps to improve the insulation reliability of the single-phase bridge arm switch module.

[0009] 2. In this utility model, the single-phase bridge arm switch module is placed in the cabinet using a drawer-type plug-in method. When one of the single-phase bridge arm switch modules fails, the faulty module can be pulled out as a whole and replaced with a spare module. There is no need to check and rewire one by one inside the cabinet, which greatly shortens the power outage time for maintenance and improves the reliability of power supply.

[0010] 3. The local power supply transformer of this invention draws power locally from the load current in the main circuit busbar to power the control board unit, eliminating the dependence on external auxiliary power cables, simplifying the internal wiring of the cabinet, and avoiding the risk of power loss to the control board unit due to external auxiliary power failure. Furthermore, the local power supply transformer and the main circuit busbar are only coupled by electromagnetic induction, with no direct electrical connection. Electrical isolation is maintained between the main circuit (power supply transformer unit) and the control circuit (control board unit), improving the safety of the control circuit.

[0011] 4. Each single-phase bridge arm switch module provided by this utility model has heat dissipation fins and air-cooling duct structure inside, so that the heat dissipation conditions of the power semiconductor devices in each single-phase bridge arm switch module are consistent and controllable, avoiding the problem of poor heat dissipation of some devices under the distributed arrangement, and improving the operational reliability and service life of the power semiconductor devices.

[0012] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0013] Figure 1 This is a cross-sectional view of a single-phase bridge arm switch module along the insertion / removal direction provided in an embodiment of this utility model; Figure 2 This is a cross-sectional view of another single-phase bridge arm switch module provided in this embodiment of the present invention along the insertion / removal direction; Figure 3 This is a cross-sectional schematic diagram of the modular bridge arm switchgear used in the bridge arm type on-load tap changer provided in this utility model embodiment, in the insertion and removal direction.

[0014] Explanation of reference numerals in the attached figures: 100-Cabinet; 101-Cabinet air inlet grille; 102-Cabinet air outlet grille; 103-Cabinet back panel busbar; 104-Cabinet front panel; 105-Cabinet rear panel; 200-Single-phase bridge arm switch module; 201-Housing front panel; 202-Housing rear panel; 203-Upper connector terminal; 204-Lower connector terminal; 205-Operating handle; 11-Main circuit busbar; 12-Ring magnetic core; 13-Secondary winding; 14-Energy extraction lead; 21-Power semiconductor device; 22-Heat dissipation substrate; 23-Heat dissipation fins; 24-Control signal line; 25-Air duct partition; 26-Housing air inlet; 27-Housing air outlet; 28-Axial flow fan; 30-Control board unit; 31-Rectifier and voltage regulator circuit; 32-Trigger drive circuit; 40-Upper insulating partition; 50-Lower insulating partition. Detailed Implementation

[0015] To further illustrate the technical means and effects adopted by this utility model to achieve its intended purpose, the following detailed description, in conjunction with the accompanying drawings and specific embodiments, describes a modular bridge arm switchgear applied in a bridge arm type on-load tap changer according to this utility model.

[0016] The foregoing and other technical contents, features, and effects of this utility model will be clearly presented in the following detailed description of the specific embodiments with reference to the accompanying drawings. Through the description of the specific embodiments, a more in-depth and specific understanding can be gained of the technical means and effects adopted by this utility model to achieve the intended purpose. However, the accompanying drawings are only provided for reference and illustration and are not intended to limit the technical solution of this utility model.

[0017] It should be noted that, in this document, the terms “comprising,” “including,” or any other variations are intended to cover non-exclusive inclusion, such that an article or device that comprises a list of elements includes not only those elements but also other elements not expressly listed.

[0018] The term "height direction" is defined as follows: the plane in which the cabinet is located is the horizontal plane, and the direction perpendicular to the horizontal plane is the height direction.

[0019] This utility model provides a modular bridge arm switchgear for use in bridge arm type on-load tap changers, such as... Figures 1-3 As shown, the modular bridge arm switch includes a cabinet 100 and multiple single-phase bridge arm switch modules 200. The cabinet 100 includes a front panel 104 and a rear panel 105 arranged opposite each other; a back panel busbar 103 is provided on the rear panel 105. Multiple single-phase bridge arm switch modules 200 are arranged side-by-side along the height of the cabinet 100; each single-phase bridge arm switch module 200 is electrically connected to the back panel busbar 103. A plug-in / plug-out guide mechanism is provided inside the cabinet 100 for each single-phase bridge arm switch module 200, and each single-phase bridge arm switch module 200 is slidably connected to the cabinet 100 through the plug-in / plug-out guide mechanism. The plug-in / plug-out direction of all single-phase bridge arm switch modules 200 is perpendicular to both the front panel 104 and the rear panel 105 of the cabinet. Each single-phase bridge arm switch module 200 includes a module housing and, from top to bottom, a power inductor unit, a power device unit, and a control board unit 30 arranged within the module housing; an upper insulating partition 40 is provided between the power inductor unit and the power device unit, and a lower insulating partition 50 is provided between the power device unit and the control board unit 30.

[0020] The modular bridge arm switchgear provided by this utility model integrates the energy harvesting transformer unit, power device unit, and control board unit 30 required for a single-phase bridge arm switch into an independent module forming a single-phase bridge arm switch module 200. Multiple single-phase bridge arm switch modules 200 are slidably assembled with the cabinet 100. This allows for rapid replacement or repair of individual single-phase bridge arm switch modules 200, significantly reducing maintenance downtime. Furthermore, within the single-phase bridge arm switch module 200, three spaces are isolated by an upper insulating partition 40 and a lower insulating partition 50, respectively accommodating the energy harvesting transformer unit, power device unit, and control board unit 30, which helps improve the insulation reliability of the single-phase bridge arm switch module 200.

[0021] In one example, the cabinet 100 also includes two opposing side panels; the insertion / removal guide mechanism consists of parallel guide rails mounted on the inner walls of the two side panels, and each single-phase bridge arm switch module 200 has a groove on its outer side wall that mates with the parallel guide rail, allowing the single-phase bridge arm switch module 200 to slide along the parallel guide rail. In other words, the single-phase bridge arm switch module 200 is removed and inserted through the cooperation of the parallel guide rail and the groove.

[0022] For example, the module housing can be a rectangular metal housing made of aluminum alloy or steel plate, and its external dimensions can be standardized and identical, allowing multiple single-phase bridge arm switch modules 200 to be arranged at equal intervals along the height direction of the cabinet 100. The module housing provides structural support and mechanical protection for the internal components of the single-phase bridge arm switch module 200, and also serves as a carrier for drawer-type plug-in operations.

[0023] For example, the front panel 201 of the module housing (the side near the front panel 104 of the cabinet) is provided with a status indicator light and a manual operation handle 205. The rear panel 202 of the module housing (the side near the rear panel 105 of the cabinet) is provided with module rear connector terminals, including an upper connector terminal 203 and a lower connector terminal 204, both of which are used for electrical connection with the corresponding terminals of the busbar 103 of the cabinet rear panel.

[0024] For example, the front end plate 201 of the module housing is also provided with a module latch, and the inner side of the cabinet 100 is provided with a latch mating hole that matches the module latch. When the single-phase bridge arm switch module 200 is fully inserted into the cabinet 100, the module latch engages with the latch mating hole to fix the single-phase bridge arm switch module 200 on the cabinet frame and prevent the single-phase bridge arm switch module 200 from loosening during operation.

[0025] For example, the housing air inlet and housing air outlet of the single-phase bridge arm switch module 200 are both equipped with dust filters.

[0026] For ease of description, the single-phase bridge arm switch module 200 is defined as having an upper space, a middle space, and a lower space separated by an upper insulating partition 40 and a lower insulating partition 50. The upper space houses the energy harvesting mutual inductor unit, the middle space houses the power device unit, and the lower space houses the control board unit 30.

[0027] In one embodiment of this utility model, the energy harvesting transformer unit includes a main circuit busbar 11 and a local energy harvesting transformer. One end of the main circuit busbar 11 is electrically connected to the upper connector terminal 203; the other end of the main circuit busbar 11 is electrically connected to the lower connector terminal 204. Figure 1 (Not shown in the diagram); the upper plug-in terminal 203 and the lower plug-in terminal 204 are both disposed through the module housing on the side near the rear panel 105 of the cabinet (i.e., the upper plug-in terminal 203 and the lower plug-in terminal 204 are disposed through the rear panel 202 of the module housing), and are both electrically connected to the busbar 103 of the cabinet back panel, realizing a quick electrical connection between the single-phase bridge arm switch module 200 and the main circuit of the cabinet (busbar 103 of the cabinet back panel). The local energy harvesting transformer includes a toroidal magnetic core 12 and a secondary winding 13; the toroidal magnetic core 12 is sleeved on the outside of the main circuit busbar 11, and the secondary winding 13 is wrapped around the outer side of the toroidal magnetic core 12, and the lead-out end of the secondary winding 13 is electrically connected to the control board unit 30.

[0028] For example, such as Figure 1 As shown, the main circuit busbar 11 can be a rectangular copper conductor, horizontally arranged in the upper space inside the module housing along the insertion and removal direction of the single-phase bridge arm switch module 200. One end of the main circuit busbar 11 is electrically connected to the upper plug-in terminal 203 in the module's rear plug-in terminal. When the single-phase bridge arm switch module 200 is inserted into the cabinet 100, the upper plug-in terminal 203 mates with the corresponding terminal of the cabinet back panel busbar 103, so that the main circuit busbar 11 is connected to the main circuit of the bridge arm type on-load tap changer.

[0029] The other end of the main circuit busbar 11 is bent downward inside the module housing. Figure 1 (Not shown in the diagram) After passing through the power device unit, it is electrically connected to the lower connector 204 in the module's rear connector terminals. Thus, the load current enters the main circuit busbar 11 from the upper connector 203, passes through the local power transformer and the power device unit, and then flows out from the lower connector 204. The main circuit busbar 11 serves to carry the load current of the bridge-arm type on-load tap changer and also acts as the primary conductor of the local power transformer.

[0030] For example, such as Figure 1As shown, the local energy harvesting transformer is installed in the upper space inside the module housing and is fitted onto the main circuit busbar 11. The toroidal core 12 is made of high-permeability nanocrystalline, amorphous alloy, ferrite, or silicon steel sheet, or other high-magnetic-content materials, as long as it can effectively draw power within the load current range of the main circuit busbar 11. The inner hole of the toroidal core 12 is fitted onto the outer circumference of the main circuit busbar 11, allowing the main circuit busbar 11 to pass through the inner hole of the core. The secondary winding 13 is uniformly wound on the outer circumference of the toroidal core 12, and its two leads are electrically connected to the control board unit 30 via energy harvesting leads 14 (connected to the rectifier and voltage regulator circuit 31 of the control board unit 30). There is no electrical connection between the local energy harvesting transformer and the main circuit busbar 11 (i.e., no direct wire connection); energy is transferred only through electromagnetic induction coupling. The main circuit busbar 11 and the control board unit 30 are electrically isolated.

[0031] The working principle of the local power supply transformer is as follows: When the load current flows through the main circuit busbar 11, the main circuit busbar 11, as the primary conductor, generates alternating magnetic flux in the toroidal core 12. This alternating magnetic flux induces an AC voltage in the secondary winding 13. After rectification and voltage regulation by the rectifier and voltage regulator circuit 31 of the control board unit 30, it provides operating power to the control board unit 30. The function of the local power supply transformer is to draw power locally from the load current flowing through the main circuit busbar 11 to power the control board unit 30 of the corresponding single-phase bridge arm switch module 200, eliminating the need to introduce auxiliary power cables from outside the cabinet 100 and eliminating dependence on external auxiliary power.

[0032] In one embodiment of this invention, the power device unit includes a heat dissipation assembly and a power semiconductor device 21 located on the upper surface of the heat dissipation assembly. The heat dissipation assembly includes a heat dissipation substrate 22 connected to the power semiconductor device 21 and an array of heat dissipation fins 23 arranged on the side of the heat dissipation substrate 22 away from the power semiconductor device 21; the heat dissipation channel formed by the heat dissipation fins 23 is at least partially parallel to the insertion / removal direction. The power semiconductor device 21 is electrically connected to the main circuit busbar 11 and is also connected to the control board unit 30. The power device unit functions as a power switching device for the bridge arm switch, controlling the on / off state of the load current.

[0033] In some examples, the module housing has an air inlet 26 on the side near the front panel 104 of the cabinet, and an air outlet 27 on the side near the rear panel 105 of the cabinet. Along the insertion / removal direction of the single-phase bridge arm switch module 200, the position of the air inlet 26 on the module housing corresponds to the power device unit. The lower part of the front panel 104 of the cabinet has a cabinet air inlet grille 101, and the upper part of the rear panel 105 of the cabinet has a cabinet air outlet grille 102. That is, cool air from the outside enters the cabinet 100 through the cabinet air inlet grille 101, and then flows through the air inlets 26 of each single-phase bridge arm switch module 200, passing through the power device unit. The cool air carries away the heat generated by the power device unit, and the heat is discharged from the single-phase bridge arm switch module 200 through the air outlet 27, and then discharged into the external environment of the cabinet 100 through the cabinet air outlet grille 102, thus achieving heat dissipation for each single-phase bridge arm switch module 200. In other possible implementations, the heat dissipation component can also be a liquid-cooled heat dissipation component, for example, using a liquid cooling plate to achieve rapid heat exchange of the power semiconductor device 21. Alternatively, the heat dissipation component can also be a heat pipe cooling method, depending on the specific configuration requirements of the bridge arm type on-load tap changer.

[0034] In some examples, the power semiconductor device 21 can be any of a thyristor chip, an insulated gate bipolar transistor, and a metal-oxide-semiconductor field-effect transistor.

[0035] Taking the power semiconductor device 21 as an example of a thyristor chip, the power device unit will be explained in detail.

[0036] like Figure 1 As shown, the power device unit is installed in the middle space inside the module housing, below the local power transformer, and is electrically isolated from it by an upper insulating partition 40. The power device unit includes a thyristor chip, a heat sink substrate 22, and heat sink fins 23. The thyristor chip is mounted on the upper surface of the heat sink substrate 22 by press-fitting or welding. The heat sink substrate 22 is a copper or aluminum plate, with the thyristor chip mounted on its upper surface and its lower surface in thermal contact with the base surface of the heat sink fins 23 (through thermal grease or welding). The heat sink fins 23 can be extruded aluminum alloy parts with a flat base surface. Multiple heat sink fins 23 are arranged below the base surface, and the heat dissipation channel formed by two adjacent heat sink fins 23 extends along the insertion direction. The heat dissipation channels formed between each heat sink fin 23 are equally spaced. The height, thickness, and spacing of the heat sink fins 23 are determined according to the heat generation power of the power device unit and the airflow velocity in the air duct. The function of the heat sink fins 23 is to transfer the heat generated by the power device unit during operation to the surface of the heat sink fins 23 through heat conduction, and then dissipate the heat into the air through convective heat exchange between the heat sink fins 23 and the cooling air flowing through the heat dissipation channel.

[0037] The anode and cathode of the thyristor chip are electrically connected to corresponding sections of the main circuit busbar 11 via copper connecting pieces, allowing the load current to flow through the thyristor chip. The gate of the thyristor chip is electrically connected to the control board unit 30 via control signal line 24. When the bridge arm switch needs to be turned on, the control board unit 30 sends a trigger pulse to the gate of the thyristor chip via control signal line 24, turning on the thyristor chip and allowing the load current to flow through it; when the bridge arm switch needs to be turned off, the thyristor chip naturally turns off when the current crosses zero.

[0038] It should be noted that, Figure 1 The power extraction lead 14 is shown as a dashed line because it only indicates the connection between the two leads of the secondary winding 13 and the control board unit 30, not their actual connection structure. Similarly, the control signal line 24, also shown as a dashed line, only indicates the connection between the gate of the thyristor chip and the control board unit 30, not their actual connection structure. It is worth noting that the upper insulating partition 40 and the lower insulating partition 50 are complete insulating partitions (without through holes in the middle). The power extraction lead 14 and the control signal line 24 are actually electrically connected to the control board unit 30 through reserved positions on the edge of the insulating partition.

[0039] In one implementation, such as Figure 2 As shown, a duct baffle 25 is also provided on the side of the heat sink 23 away from the power semiconductor device 21. The height of the duct baffle 25 is no greater than the height of the lower edge of the housing air inlet 26. The duct baffle 25 is a horizontally positioned baffle, located below the heat sink 23 and above the lower insulating baffle 50, so that cooling air flows centrally through the heat dissipation channels of the heat sink 23, preventing hot air from being directly blown towards the control board unit 30 area. This forms the following airflow: cooling air enters the single-phase bridge arm switch module 200 from the housing air inlet 26, flows horizontally through the heat dissipation channels between the fins of the heat sink 23, undergoes convective heat exchange with the surface of the heat sink 23, and is then discharged from the housing air outlet 27 of the single-phase bridge arm switch module 200, dissipating the heat from the power device unit into the air.

[0040] Furthermore, an axial fan 28 is provided at the air outlet 27 of the housing. The axial fan 28 is a DC brushless fan, and its power supply is provided by the control board unit 30 (rectifier and voltage regulator circuit 31). The function of the axial fan 28 is to create forced convection within the air duct, thereby improving the heat dissipation efficiency of the heat sink fins 23.

[0041] In one embodiment of this utility model, the control board unit 30 includes a rectifier and voltage regulator circuit 31 and a trigger drive circuit 32. The input terminal of the rectifier and voltage regulator circuit 31 is electrically connected to the lead-out terminal of the secondary winding 13; the input terminal of the trigger drive circuit 32 is used to connect to the voltage regulator controller of the bridge arm type on-load tap changer, and the output terminal of the trigger drive circuit 32 is electrically connected to the power semiconductor device 21.

[0042] In one example, such as Figure 1 As shown, the control board unit 30 is located in the lower space within the module housing, below the lower insulating partition 50, to achieve electrical and thermal isolation. The control board unit 30 is a printed circuit board, integrating a rectifier and voltage regulator circuit 31 and a trigger drive circuit 32. The input terminal of the rectifier and voltage regulator circuit 31 is electrically connected to the lead-out terminal of the secondary winding of the local power transformer, used to rectify the AC voltage output by the local power transformer into a DC voltage, which is then regulated by the rectifier and voltage regulator circuit 31 to provide a stable operating power supply for the various circuits on the control board unit 30. The input terminal of the trigger drive circuit 32 is connected to the voltage regulator controller of the bridge-arm on-load tap changer via fiber optic communication, wireless communication, shielded cable, or CAN bus, used to receive switching operation commands from the voltage regulator controller. The output terminal of the trigger drive circuit 32 is electrically connected to the power semiconductor device 21 in the power device unit. For example, the output terminal of the trigger drive circuit 32 is electrically connected to the gate of the thyristor chip, used to send trigger pulse signals to the thyristor chip according to the commands of the voltage regulator controller. The function of the control board unit 30 is to receive the electrical energy provided by the local energy transformer and convert it into a stable working power supply. At the same time, it receives the instructions of the voltage regulator and drives the power semiconductor device 21 in the power device unit to complete the switching action.

[0043] In one example, both the upper insulating partition 40 and the lower insulating partition 50 are flat insulating components made of epoxy resin board or phenolic laminate, and are horizontally arranged inside the module housing. The upper insulating partition 40 electrically isolates the upper space (main circuit busbar 11 and local power transformer) inside the module housing from the middle space (power device unit), preventing the high voltage of the main circuit busbar 11 from posing an insulation threat to the power device unit and control board unit 30. The lower insulating partition 50 electrically and thermally isolates the middle space from the lower space (control board unit 30), preventing the heat-carrying air flowing through the heat sink fins 23 from causing thermal damage to the electronic components on the control board unit 30, while maintaining electrical isolation between the power circuit and the control circuit.

[0044] like Figure 3As shown, taking eight single-phase bridge arm switch modules 200 as an example, their arrangement in the cabinet 100 is illustrated. Each single-phase bridge arm switch module 200 is arranged at equal intervals along the height of the cabinet 100. Each single-phase bridge arm switch module 200 corresponds to one bridge arm switch (T1-T6) or one transition switch (K1, K2) position in the bridge arm type on-load tap changer. When the single-phase bridge arm switch module 200 is fully inserted into the cabinet 100 along the guide rail, the upper connector 203 and lower connector 204 of the module's rear connector automatically connect to the corresponding terminals on the cabinet's back panel busbar 103, completing the electrical connection of the main circuit. The module latch on the front panel 201 of the single-phase bridge arm switch module 200 engages with the latching hole on the cabinet 100, fixing the single-phase bridge arm switch module 200 inside the cabinet 100. Thus, when a single-phase bridge arm switch module 200 needs to be maintained or replaced, the operator can open the module latch, pull out the corresponding single-phase bridge arm switch module 200 along the guide rail, replace it with a spare module, and reinsert it to restore operation. There is no need to perform wiring and troubleshooting one by one inside the cabinet 100.

[0045] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the protection scope of the present invention.

Claims

1. A modular bridge arm switchgear for use in a bridge arm type on-load tap changer, characterized in that, include: The cabinet (100) includes a front panel (104) and a back panel (105) arranged opposite to each other; a back panel busbar (103) is provided on the back panel (105); Multiple single-phase bridge arm switch modules (200) are arranged side by side along the height direction of the cabinet (100); each of the single-phase bridge arm switch modules (200) is electrically connected to the busbar (103) of the cabinet back panel; The cabinet (100) is equipped with a plug-in guide mechanism for each single-phase bridge arm switch module (200) on its inner side, and each single-phase bridge arm switch module (200) is slidably connected to the cabinet (100) through the plug-in guide mechanism; The insertion and removal direction of the single-phase bridge arm switch module (200) is perpendicular to both the front panel (104) and the rear panel (105) of the cabinet. The single-phase bridge arm switch module (200) includes a module housing and, from top to bottom, a power inductor unit, a power device unit, and a control board unit (30) arranged in sequence within the module housing; an upper insulating partition (40) is provided between the power inductor unit and the power device unit, and a lower insulating partition (50) is provided between the power device unit and the control board unit (30).

2. The modular bridge arm switchgear applied in a bridge arm type on-load tap changer according to claim 1, characterized in that, The cabinet (100) also includes two side panels arranged opposite to each other; The insertion and removal guide mechanism is a parallel guide rail set on the inner wall of the two side plates. Each single-phase bridge arm switch module (200) has a groove on its outer side wall that cooperates with the parallel guide rail, so that the single-phase bridge arm switch module (200) slides along the parallel guide rail.

3. The modular bridge arm switchgear applied in a bridge arm type on-load tap changer according to claim 1, characterized in that, The energy harvesting transformer unit includes a main circuit busbar (11) and a local energy harvesting transformer; One end of the main circuit busbar (11) is electrically connected to the upper plug-in terminal (203); the other end of the main circuit busbar (11) is electrically connected to the lower plug-in terminal (204); the upper plug-in terminal (203) and the lower plug-in terminal (204) are both disposed through the module housing on the side near the cabinet back panel (105), and are both electrically connected to the cabinet back panel busbar (103); The local power transformer includes a toroidal magnetic core (12) and a secondary winding (13); the toroidal magnetic core (12) is sleeved on the outside of the main circuit busbar (11), the secondary winding (13) is wrapped around the outer side of the toroidal magnetic core (12), and the lead-out end of the secondary winding (13) is electrically connected to the control board unit (30).

4. The modular bridge arm switchgear applied in a bridge arm type on-load tap changer according to claim 3, characterized in that, The power device unit includes a heat dissipation assembly and a power semiconductor device (21) located on the upper surface of the heat dissipation assembly; The heat dissipation assembly includes a heat dissipation substrate (22) connected to the power semiconductor device (21) and an array of heat dissipation fins (23) arranged on the side of the heat dissipation substrate (22) away from the power semiconductor device (21); the heat dissipation channel formed by the heat dissipation fins (23) is at least partially parallel to the insertion / removal direction. The power semiconductor device (21) is electrically connected to the main circuit busbar (11), and at the same time, the power semiconductor device (21) is connected to the control board unit (30).

5. The modular bridge arm switchgear applied in a bridge arm type on-load tap changer according to claim 4, characterized in that, The module housing has a housing air inlet (26) on the side near the front panel (104) of the cabinet, and a housing air outlet (27) on the side near the back panel (105) of the cabinet; along the insertion and removal direction of the single-phase bridge arm switch module (200), the housing air inlet (26) is positioned on the module housing in a manner corresponding to the power device unit; The lower part of the front panel (104) of the cabinet has a cabinet air inlet grille (101), and the upper part of the rear panel (105) of the cabinet has a cabinet air outlet grille (102).

6. The modular bridge arm switchgear applied in a bridge arm type on-load tap changer according to claim 5, characterized in that, A duct baffle (25) is also provided on the side of the heat dissipation fins (23) away from the power semiconductor device (21); Along the height direction, the height of the air duct baffle (25) is not greater than the height of the lower edge of the housing air inlet (26).

7. The modular bridge arm switchgear applied in a bridge arm type on-load tap changer according to claim 6, characterized in that, An axial fan (28) is provided at the air outlet (27) of the housing.

8. The modular bridge arm switchgear applied in a bridge arm type on-load tap changer according to claim 7, characterized in that, The power semiconductor device (21) is one of a thyristor chip, an insulated gate bipolar transistor, and a metal oxide semiconductor field-effect transistor.

9. The modular bridge arm switchgear applied in a bridge arm type on-load tap changer according to claim 4, characterized in that, The control board unit (30) includes a rectifier and voltage regulator circuit (31) and a trigger drive circuit (32); The input terminal of the rectifier and voltage regulator circuit (31) is electrically connected to the lead-out terminal of the secondary winding (13); the input terminal of the trigger drive circuit (32) is used to connect to the voltage regulator controller, and the output terminal of the trigger drive circuit (32) is electrically connected to the power semiconductor device (21).

10. The modular bridge arm switchgear applied in a bridge arm type on-load tap changer according to claim 1, characterized in that, The single-phase bridge arm switch module (200) has an operating handle (205) and a module lock on the side of the module housing near the front panel (104) of the cabinet; The inner side of the cabinet (100) is provided with a locking hole that matches the module locking buckle, for fixing the single-phase bridge arm switch module (200) inside the cabinet (100).

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