An alternating current contactor

Abstract

This invention provides an AC contactor, wherein a power supply board is arranged above an upper pressure plate, and an insulating support component is provided between the power supply board and the upper pressure plate. A lower pressure plate is arranged below the upper pressure plate, and a bidirectional thyristor is located between the upper and lower pressure plates. Heat sinks are symmetrically arranged on both sides of the bidirectional thyristor. A drive plate electrically connected to the power supply board and the bidirectional thyristor is provided on one side of each of the upper and lower pressure plates. The upper and lower pressure plates are connected to each other by evenly spaced tie rods. The AC contactor provided by this invention, based on a bidirectional thyristor and employing a press-fit structure, features a compact structure, short breaking time, no mechanical wear, and strong current carrying capacity. Furthermore, by controlling the thyristor's turn-on angle, it achieves the system charging function, and can replace the charging contactor and charging resistor functions required in the original system, making it widely applicable.

Description

Technical Field

[0001] This invention relates to the field of power electronic converter technology for rail transit, specifically to an AC contactor. Background Technology

[0002] Currently, most AC contactors on the market are still mechanical products. Traditional mechanical contactors suffer from problems such as long breaking times, contact erosion, and mechanical wear. Although various contactless AC contactor products have emerged to replace traditional AC contactors, most are low-voltage products, while traditional mechanical contactors still dominate the medium and high voltage fields. Therefore, developing a widely applicable contactless AC contactor product is particularly important. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide an AC contactor based on a bidirectional thyristor and using a press-fit structure. It has a compact structure, short breaking time, no mechanical wear, and strong current carrying capacity. At the same time, the system charging function is realized by controlling the opening angle of the thyristor. It can replace the charging contactor and charging resistor functions required by the original system and has wide applicability.

[0004] To solve the above-mentioned technical problems, the technical solution proposed by this invention is as follows:

[0005] An AC contactor includes a power supply board, an upper pressure plate, a heat sink, a bidirectional thyristor, and a lower pressure plate. The power supply board is arranged above the upper pressure plate, and an insulating support component is provided between the power supply board and the upper pressure plate. The lower pressure plate is arranged below the upper pressure plate. The bidirectional thyristor is located between the upper and lower pressure plates. The heat sink is symmetrically arranged on both sides of the bidirectional thyristor. A drive plate electrically connected to the power supply board and the bidirectional thyristor is provided on one side of the upper and lower pressure plates, respectively. The upper and lower pressure plates are pressed together by tie rods arranged at even intervals.

[0006] The AC contactor according to the present invention uses a bidirectional thyristor as the main switching device, a single device realizes bidirectional flow, and integrates a thyristor drive board and a power supply board. The heat sink is symmetrically arranged on both sides of the bidirectional thyristor and adopts a compact press-fit structure. Therefore, it has the advantages of compact structure, short breaking time, no mechanical wear, and strong current carrying capacity.

[0007] The above technical solution can be further improved as described below.

[0008] According to a preferred embodiment of the AC contactor of the present invention, both ends of the pull rod are provided with a first thread structure, the upper pressure plate is provided with a clamping nut and a washer that cooperate with the first thread structure, the lower pressure plate is provided with a hollow mounting post that can cooperate with the pull rod, and the inner wall of the hollow mounting post is provided with a second thread structure that can cooperate with the first thread structure.

[0009] The above-described tie rod press-fit positioning structure allows the entire contactor to be press-fitted using a press. The press force is applied to the upper pressure plate, and after the preset pressure is reached, the clamping nut and washer are tightened. Alternatively, the clamping torque of the clamping nut can be controlled to tighten it. When tightening, the clamping nut is tightened diagonally in sequence to ensure that the upper and lower pressure plates are in a parallel state after press-fitting. The entire press-fitting process is stable, reliable, and easy to operate.

[0010] Furthermore, in a preferred embodiment, the driver board is provided with resistors and capacitors that are electrically connected to each other, and the resistors and capacitors are electrically connected to the two ends of the bidirectional thyristor respectively.

[0011] Adding a resistor-capacitor (RC) circuit to the driver board can effectively absorb high-frequency or low-frequency signals, thus acting as a filter. In cases where the voltage change rate is small or a high-voltage bidirectional thyristor is used, the resistor-capacitor circuit may not be necessary.

[0012] Specifically, in a preferred embodiment, the radiator is a water-cooled radiator, and an insulating plate and a copper busbar are arranged sequentially from top to bottom between the radiator and the bidirectional thyristor.

[0013] The bidirectional thyristor device is water-cooled. Considering that many applications do not use deionized water (due to its very low conductivity), ordinary water (with relatively high conductivity) is used for cooling the heat sink. An insulating plate separates the heat sink from the thyristor, and a copper busbar is added between the thyristor and the insulating plate to bring out the corresponding electrodes, thus meeting the requirements for high current carrying capacity. Since the heat sink only contacts the bidirectional thyristor on one side, it can be designed as a single-sided flow channel, resulting in lower overall flow resistance.

[0014] Specifically, in a preferred embodiment, the outgoing copper busbar includes a circular plate structure that mates with an insulating plate and a bidirectional thyristor, a first extension that extends horizontally along the circular plate structure, and a second extension that is bent in a direction perpendicular to the first extension. There is a preset height difference between the first extension and the outer surface of the circular plate structure that mates with the heat sink.

[0015] The electricity on the outgoing copper busbar can creep up to the heat sink through the insulating plate. It is necessary to ensure the creepage distance required by the standard. The outgoing copper busbar with the above structure has a step with a preset height difference. The circular part of the step contacts the insulating plate, while the other part does not contact the insulating plate. This can effectively increase the creepage distance and make the size of the insulating plate relatively small.

[0016] Furthermore, in a preferred embodiment, the water path between the radiators symmetrically arranged on both sides of the bidirectional thyristor is connected in series with the water pipes via quick-connect fittings on the radiators, and the radiators are also provided with quick-connect fittings for connecting to external water paths.

[0017] The two radiator water circuits are connected in series using quick-connect fittings and water pipes, and the external water circuit interface uses quick-connect fittings, making the connection simple.

[0018] Specifically, in a preferred embodiment, the insulating plate is made of aluminum nitride (ALN).

[0019] Insulation boards made of ALN material have excellent thermal conductivity and insulation properties, and can effectively serve as insulation and heat conduction boards.

[0020] Furthermore, in a preferred embodiment, a thermally conductive silicone grease layer is applied between the heat sink and the insulating plate, and between the insulating plate and the outgoing copper busbar.

[0021] By applying a thermally conductive silicone grease layer, the contact thermal resistance between the heat sink and the insulating plate, as well as between the insulating plate and the outgoing copper busbar, can be effectively reduced, thereby effectively improving the heat dissipation effect of the heat sink.

[0022] Furthermore, in a preferred embodiment, a conductive and thermally conductive silicone grease layer is applied between the outgoing copper busbar and the bidirectional thyristor.

[0023] By applying a conductive and thermally conductive silicone grease layer between the outgoing copper busbar and the bidirectional thyristor, the contact thermal resistance between the two can be effectively reduced while ensuring conductivity, thus improving the heat sink performance.

[0024] Furthermore, in a preferred embodiment, the upper pressure plate, the lower pressure plate, the heat sink, and the copper busbar are provided with evenly spaced positioning holes, and a removable positioning rod is provided in the positioning hole.

[0025] The combination of the positioning holes and positioning rods makes the positioning of the insulation board and the copper busbar more stable and reliable during installation, which makes the assembly of the entire AC contactor more convenient. Furthermore, the positioning rods can be reused during mass production, thus effectively saving costs.

[0026] Furthermore, in a preferred embodiment, a control board electrically connected to the power board and the bidirectional thyristor is provided above the upper pressure plate, and an insulating support component is provided between the control board and the upper pressure plate.

[0027] The control board enables the charging function of the system's backend by controlling the opening angle of the bidirectional thyristor. This replaces the method of using a charging contactor and charging resistor to charge the backend system in some situations, effectively simplifying the structure, saving costs, and improving the overall applicability of the AC contactor. When the contactor is operating normally, the bidirectional thyristor is driven by a constant pulse, meaning the thyristor's drive pulse is continuously maintained. Simultaneously, the control board can also be used for external signal communication, command execution, fault transmission, and the issuance of drive signals.

[0028] Furthermore, in a preferred embodiment, the radiator is provided with a temperature measuring device electrically connected to the control board.

[0029] A temperature measuring device is installed on the radiator to detect the temperature on the radiator and transmit the temperature signal to the control board. The control board reads the temperature signal, makes judgments and analyses, thereby effectively improving the heat dissipation effect of the radiator.

[0030] Furthermore, in a preferred embodiment, a force transmission pad is provided between the upper pressure plate and the heat sink, and the force transmission pad has an inverted conical structure.

[0031] By using force transmission pads, it is possible to ensure that the force is stably and reliably transmitted to the pressed parts during the pressing process, and the conical force transmission pads can make the pressing force transmission more uniform.

[0032] Furthermore, in a preferred embodiment, an elastic support member is provided between the radiator and the lower pressure plate.

[0033] By setting up elastic support components, the stress on the entire AC contactor during the press-fitting process can be buffered, thus providing good protection for each press-fitting component.

[0034] Specifically, in a preferred embodiment, the elastic support component includes a spring plate and a disc spring sleeved on the spring plate, with the lower pressure plate and the spring plate positioned and installed through pin holes.

[0035] The elastic support component using the above-mentioned combined structure is structurally stable and reliable, and can protect the components from damage during the pressing process to the greatest extent.

[0036] Compared with the prior art, the advantages of this invention are: based on bidirectional thyristors and using a press-fit structure, it has a compact structure, short switching time, no mechanical wear, and strong current carrying capacity. At the same time, by controlling the switching angle of the thyristor, the system charging function can be realized, which can replace the charging contactor and charging resistor functions required by the original system, and has wide applicability. Attached Figure Description

[0037] The invention will now be described in more detail with reference to embodiments and the accompanying drawings.

[0038] Figure 1 The schematic diagram illustrates the main circuit topology of an AC contactor according to an embodiment of the present invention;

[0039] Figure 2 The schematic diagram illustrates the three-dimensional structure of an AC contactor according to an embodiment of the present invention;

[0040] Figure 3 The schematic diagram shows the three-dimensional structure of the AC contactor in another direction according to an embodiment of the present invention;

[0041] Figure 4 The schematic diagram shows the three-dimensional structure of the AC contactor in another direction according to an embodiment of the present invention;

[0042] Figure 5 The schematic diagram illustrates the three-dimensional structure of the force transmission pad in an embodiment of the present invention;

[0043] Figure 6 The schematic diagram illustrates the three-dimensional structure of the force transmission pad block in another direction in an embodiment of the present invention;

[0044] Figure 7 The schematic diagram illustrates the three-dimensional structure of the outgoing copper busbar in an embodiment of the present invention;

[0045] Figure 8 The schematic diagram illustrates the positioning structure of the spring plate, disc spring, and pressure plate in an embodiment of the present invention.

[0046] In the accompanying drawings, the same parts use the same reference numerals. The drawings are not drawn to scale. Detailed Implementation

[0047] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments, but this does not limit the scope of protection of the present invention.

[0048] Figure 1 The schematic diagram illustrates the main circuit topology of the AC contactor 10 according to an embodiment of the present invention. Figure 2 The schematic diagram shows the three-dimensional structure of the AC contactor 10 according to an embodiment of the present invention. Figure 3 The schematic diagram shows the three-dimensional structure of the AC contactor 10 according to an embodiment of the present invention from another direction. Figure 4 The schematic diagram shows the three-dimensional structure of the AC contactor 10 according to an embodiment of the present invention from another direction. Figure 5 The schematic diagram shows the three-dimensional structure of the force transmission pad 103 in an embodiment of the present invention. Figure 6 The schematic diagram shows the three-dimensional structure of the force transmission pad 103 in another direction in an embodiment of the present invention. Figure 7 The schematic diagram shows the three-dimensional structure of the copper busbar 9 in an embodiment of the present invention. Figure 8 The schematic diagram illustrates the positioning structure of the spring plate 1031, disc spring 1032, and lower pressure plate 5 in an embodiment of the present invention.

[0049] like Figures 1 to 4 As shown, the AC contactor 10 of this embodiment includes a power board 1, an upper pressure plate 2, a heat sink 3, a bidirectional thyristor 4, and a lower pressure plate 5. The power board 1 is arranged above the upper pressure plate 2, and insulating support columns 6 are evenly spaced between the power board 1 and the upper pressure plate 2. The lower pressure plate 5 is arranged below the upper pressure plate 1. The bidirectional thyristor 4 is located between the upper pressure plate 2 and the lower pressure plate 5. The heat sink 3 is symmetrically arranged on both sides of the bidirectional thyristor 4. A drive plate 7 is provided on one side of the upper pressure plate 2 and the lower pressure plate 5, which is electrically connected to the power board 1 and the bidirectional thyristor 4, respectively. The upper pressure plate 2 and the lower pressure plate 5 are pressed together by tie rods 7 arranged at even intervals.

[0050] According to an embodiment of the present invention, the AC contactor uses a bidirectional thyristor as the main switching device, a single device realizes bidirectional flow, and integrates a thyristor drive board and a power supply board. Heat sinks are symmetrically arranged on both sides of the bidirectional thyristor. It adopts a compact press-fit structure, thus having the advantages of compact structure, short breaking time, no mechanical wear, and strong current carrying capacity.

[0051] Specifically, in this embodiment, both ends of the pull rod 7 are provided with a first thread structure. The upper pressure plate 2 is provided with a clamping nut and a washer structure 21 that mate with the first thread structure. The lower pressure plate 5 is provided with a hollow mounting post 51 that mates with the pull rod 7. The inner wall of the hollow mounting post 51 is provided with a second thread structure that mates with the first thread structure. The pull rod press-fitting positioning structure described above allows the entire contactor to be press-fitted using a press. The force of the press press is applied to the upper pressure plate, and after reaching the preset pressure, the clamping nut and washer are tightened. Alternatively, the clamping torque of the clamping nut can be controlled to tighten it. During tightening, the clamping nuts are tightened diagonally in sequence to ensure that the upper and lower pressure plates are in a parallel state after press-fitting. The entire press-fitting process is stable, reliable, and easy to operate.

[0052] like Figure 4As shown, further, in this embodiment, the driver board 7 is provided with a resistor 71 and a capacitor 72 that are electrically connected to each other, and the resistor 71 and capacitor 72 are respectively electrically connected to the two ends of the bidirectional thyristor 4. The resistor-capacitor (RC) circuit on the driver board can effectively absorb high-frequency or low-frequency signals, i.e., it serves a filtering function. In cases where the voltage change rate is small or a high-voltage bidirectional thyristor is used, the resistor-capacitor circuit may not be necessary.

[0053] Specifically, in this embodiment, such as Figure 2 and Figure 3 As shown, heat sink 3 is a water-cooled heat sink, and an insulating plate 8 and a copper busbar 9 are arranged sequentially from top to bottom between heat sink 3 and bidirectional thyristor 4. The bidirectional thyristor device is water-cooled. Considering that many applications do not use deionized water (which has very low conductivity), ordinary water (with relatively high conductivity) is used for cooling the heat sink. The heat sink is separated by an insulating plate, and a copper busbar is added between the thyristor and the insulating plate to lead out the corresponding electrodes, thereby meeting the requirements for high current carrying capacity. Since the heat sink only contacts the bidirectional thyristor on one side, the heat sink can be designed as a single-sided flow channel, thus reducing the overall flow resistance.

[0054] like Figure 7 As shown, specifically in this embodiment, the outgoing copper busbar 9 includes a circular plate structure 91 that mates with the insulating plate 8 and the bidirectional thyristor 4, a first extension 92 extending horizontally along the circular plate structure 91, and a second extension 93 bent in a direction perpendicular to the first extension 91. There is a preset height difference between the first extension 92 and the outer surfaces of the circular plate structure 91 that mate with the heat sink 3. Electricity on the outgoing copper busbar can creep up to the heat sink through the insulating plate. To ensure the required creepage distance, the outgoing copper busbar with the above-described structure uses a step with a preset height difference. The circular portion of the step contacts the insulating plate, while the other portion does not. This effectively increases the creepage distance and makes the size of the insulating plate relatively small.

[0055] like Figure 2 As shown, further, in this embodiment, the water path between the radiators 3 symmetrically arranged on both sides of the bidirectional thyristor 4 is connected in series via a quick-connect fitting 31 and a water pipe 32 arranged on the radiator 3, and the radiator 31 is also provided with a quick connector 33 for connecting to the external water path. The water paths of the two radiators are connected in series using quick-connect fittings and water pipes, and the external water path interface uses a quick connector, making the connection simple.

[0056] Specifically, in this embodiment, the insulating plate 8 is made of aluminum nitride (ALN). The ALN insulating plate has excellent thermal conductivity and insulation properties, effectively serving as both insulation and heat conduction. Furthermore, in this embodiment, a thermally conductive silicone grease layer is applied between the heat sink 3 and the insulating plate 8, and between the insulating plate 8 and the outgoing copper busbar 9. Applying the thermally conductive silicone grease layer effectively reduces the contact thermal resistance between the heat sink and the insulating plate, and between the insulating plate and the outgoing copper busbar, thereby effectively improving the heat dissipation effect of the heat sink. Furthermore, in this embodiment, a conductive and thermally conductive silicone grease layer is applied between the outgoing copper busbar 9 and the bidirectional thyristor 4. Applying a conductive and thermally conductive silicone grease layer between the outgoing copper busbar and the bidirectional thyristor ensures conductivity while effectively reducing the contact thermal resistance between them, thus improving the heat sink's performance.

[0057] like Figures 2 to 4 As shown, further, in this embodiment, a control board 101 is provided above the upper pressure plate 2, which is electrically connected to the power supply board 1 and the bidirectional thyristor 4 respectively. Insulating support columns 6 are evenly spaced between the control board 101 and the upper pressure plate 2. The control board 101 can realize the charging function of the system's backend by controlling the opening angle of the bidirectional thyristor. This can replace the method of using a charging contactor and charging resistor to charge the backend system in some situations, thereby effectively simplifying the structure, saving costs, and improving the applicability of the entire AC contactor. When the contactor is normally conducting, the bidirectional thyristor is driven by a constant pulse, that is, the driving pulse of the thyristor is maintained continuously. Simultaneously, the control board can also be used for external signal communication, command execution, fault transmission, and the issuance of drive signals.

[0058] like Figure 2 As shown, in this embodiment, the radiator 3 is further provided with a temperature sensor 34 electrically connected to the control board 101. A temperature measuring device is arranged on the radiator to detect the temperature on the radiator and transmit the temperature signal to the control board. The control board reads the temperature signal, makes judgments and analyses, thereby effectively improving the heat dissipation effect of the radiator.

[0059] like Figure 4 As shown, further, in this embodiment, the upper pressure plate 2, lower pressure plate 5, heat sink 3, and copper busbar 9 are provided with evenly spaced positioning holes, and removable positioning rods 102 are provided in the positioning holes. Through the cooperation of the positioning holes and positioning rods, the positioning of the insulating plate and copper busbar during installation is more stable and reliable, thereby making the assembly of the entire AC contactor more convenient. Furthermore, the positioning rods can be reused during mass production, thus effectively saving costs.

[0060] like Figure 3 , Figure 5 and Figure 6As shown, further, in this embodiment, a force transmission pad 103 is provided between the upper pressure plate 2 and the heat sink 3. The force transmission pad 103 has an inverted conical structure. By using the force transmission pad, it can be ensured that the force during the pressing process is stably and reliably transmitted to the pressed parts, and the conical force transmission pad can make the pressing force transmission more uniform.

[0061] like Figure 3 and Figure 8 As shown, in this embodiment, an elastic support component 104 is provided between the radiator 3 and the lower pressure plate 5. By providing the elastic support component, the force on the entire AC contactor during the press-fitting process can be buffered, thereby providing good protection for each press-fitting component. Specifically, in this embodiment, the elastic support component includes a spring plate 1041 and a disc spring 1032 sleeved on the spring plate 1041. The lower pressure plate 5 and the spring plate 1031 are positioned and installed through pin holes. The elastic support component with the above-described combined structure is structurally stable and reliable, and can maximize the protection of components from damage during the press-fitting process.

[0062] As can be seen from the above embodiments, the AC contactor of the present invention is based on a bidirectional thyristor and adopts a press-fit structure. It has a compact structure, short breaking time, no mechanical wear, and strong current carrying capacity. At the same time, the system charging function is realized by controlling the opening angle of the thyristor. It can replace the charging contactor and charging resistor functions required by the original system and has wide applicability.

[0063] Although the invention has been described with reference to preferred embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the invention. In particular, the technical features mentioned in the various embodiments can be combined in any manner as long as there is no structural conflict. The invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. An AC contactor, characterized by, It includes a power supply board, an upper voltage plate, a heat sink, a bidirectional thyristor, and a lower voltage plate; among which, The power board is arranged above the upper pressure plate, and an insulating support component is provided between the power board and the upper pressure plate; The lower pressure plate is arranged below the upper pressure plate, the bidirectional thyristor is located between the upper pressure plate and the lower pressure plate, and the heat sink is symmetrically arranged on both sides of the bidirectional thyristor; One side of the upper pressure plate and the lower pressure plate is provided with a drive board that is electrically connected to the power board and the bidirectional thyristor, respectively. The upper pressure plate and the lower pressure plate are connected to each other by tie rods arranged at even intervals; Both ends of the pull rod are provided with a first thread structure. The upper pressure plate is provided with a clamping nut and a washer that cooperate with the first thread structure. The lower pressure plate is provided with a hollow mounting post that can cooperate with the pull rod. The inner wall of the hollow mounting post is provided with a second thread structure that can cooperate with the first thread structure. The driver board is provided with resistors and capacitors that are electrically connected to each other, and the resistors and capacitors are respectively electrically connected to the two ends of the bidirectional thyristor; Above the upper pressure plate is a control board that is electrically connected to the power board and the bidirectional thyristor respectively, and an insulating support component is provided between the control board and the upper pressure plate.

2. The AC contactor according to claim 1, characterized in that, The radiator is a water-cooled radiator, and an insulating plate and a copper busbar are arranged between the radiator and the bidirectional thyristor from top to bottom.

3. The AC contactor according to claim 2, characterized in that, The outgoing copper busbar includes a circular plate structure that mates with the insulating plate and the bidirectional thyristor, a first extension extending horizontally along the circular plate structure, and a second extension bent in a direction perpendicular to the first extension. There is a preset height difference between the first extension and the outer surface of the circular plate structure that mates with the heat sink.

4. The AC contactor according to claim 2, characterized in that, The water passage between the radiators symmetrically arranged on both sides of the bidirectional thyristor is connected in series with the water pipes via quick-connect fittings on the radiators, and the radiators are also provided with quick-connect fittings for connecting to external water passages.

5. The AC contactor according to claim 2, characterized in that, The insulating board is made of aluminum nitride.

6. The AC contactor according to claim 2, characterized in that, A thermally conductive silicone grease layer is applied between the heat sink and the insulating plate, and between the insulating plate and the outgoing copper busbar.

7. The AC contactor according to claim 2, characterized in that, A conductive and thermally conductive silicone grease layer is applied between the outgoing copper busbar and the bidirectional thyristor.

8. The AC contactor according to claim 2, characterized in that, The upper pressure plate, the lower pressure plate, the heat sink, and the copper busbar are provided with evenly spaced positioning holes, and a removable positioning rod is provided in each positioning hole.

9. The AC contactor according to claim 1, characterized in that, The radiator is equipped with a temperature measuring device that is electrically connected to the control board.

10. The AC contactor according to claim 1, characterized in that, A force-transmitting pad is provided between the upper pressure plate and the heat sink, and the force-transmitting pad has an inverted conical structure.

11. The AC contactor according to claim 1, characterized in that, An elastic support component is provided between the radiator and the lower pressure plate.

12. The AC contactor according to claim 11, characterized in that, The elastic support component includes a spring plate and a disc spring sleeved on the spring plate; the lower pressure plate is positioned and installed with the spring plate through a pin hole.

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