Power modules based on integrated gate-commutated thyristors

Abstract

The present invention relates to a power module based on an integrated gate-commutated thyristor, and to the field of power electronics technology. The power module based on an integrated gate-commutated thyristor of the present invention comprises at least two stacked power subunits. Since adjacent power subunits are symmetrically arranged about the upper surface or the lower surface of a first device, the current directions in adjacent first conduction structures can be opposite, and the current directions in adjacent second conduction structures are also opposite, and the electromagnetic induction generated by the currents flowing in opposite directions will partially offset each other, thereby achieving the purpose of reducing the loop stray inductance.

Description

Technical Field

[0001] The invention relates to the technical field of power electronics, and in particular to a power module based on an integrated gate-commutated thyristor. Background Art

[0002] Integrated Gate Commutated Thyristors (IGCT) are high-efficiency and high-reliability power semiconductor devices, which are developed from Gate Turn-off Thyrisitors (GTO). When turned on, IGCT is a gate turn-off thyristor (GTO), and when turned off, it is a transistor. It has the characteristics of fast switching speed and low switching loss of transistors and low conduction loss, high blocking voltage and large output current of thyristors. Therefore, it combines the high-speed switching characteristics of Insulated Gate Bipolar Transistor (IGBT) and the high blocking voltage and low conduction loss characteristics of GTO.

[0003] The current 4-inch IGCT bidirectional circuit breaker press-fit structure presses five groups of H-bridge circuits in series, among which there is a large stray inductance of the circuit, which has a significant impact on the shutdown capability of the device. Summary of the invention

[0004] The present invention provides a power module based on an integrated gate commutated thyristor, which is used for reducing loop stray inductance.

[0005] The present invention provides a power module based on an integrated gate-commutated thyristor, comprising at least two stacked power subunits, each of which comprises a first device and at least two second device assemblies;

[0006] The first device and at least two second devices are electrically connected through a first conductive structure and a second conductive structure respectively;

[0007] Wherein, in the stacking direction of the power subunits, adjacent power subunits are symmetrical to each other, so that the current directions in adjacent first conductive structures are opposite, and the current directions in adjacent second conductive structures are also opposite.

[0008] In one embodiment, an angle is formed between the first conductive structure and the second conductive structure.

[0009] In one embodiment, at least two RC absorption units are further included, wherein the RC absorption units are respectively arranged on insulating plates located at the sides of the power subunit, and the RC absorption units are respectively electrically connected to the corresponding first devices through third conductive structures having a bending angle;

[0010] Wherein, in the stacking direction of the power subunits, the current directions in the adjacent third conductive structures are opposite.

[0011] In one embodiment, the bending angle of the third conductive structure is an obtuse angle.

[0012] In one embodiment, a groove is provided on a portion of the insulating plate between two adjacent RC absorption units, and the groove is used to increase the creepage distance.

[0013] In one embodiment, the second device assembly comprises:

[0014] second devices, which are at least two; and

[0015] a metal block disposed between two of the second devices;

[0016] The two second devices are symmetrical to each other in the stacking direction of the power subunit.

[0017] In one embodiment, a first insulating block is disposed between adjacent first components, and metal pads for contacting surfaces of the first components are respectively disposed at opposite ends of the first insulating block.

[0018] In one embodiment, a groove surrounding the circumference of the first insulating block is disposed on the side wall of the first insulating block.

[0019] In one embodiment, the device further comprises a frame, in which the power subunit is arranged; and an isolation transformer and a power supply for supplying power to the first device are also arranged in the frame.

[0020] In one embodiment, a central force applying mechanism for pressing the power subunits together is further included.

[0021] Compared with the prior art, the advantage of the present invention is that, since adjacent power subunits are symmetrically arranged about the upper surface or the lower surface of the first device, the current directions in adjacent first conductive structures can be opposite, and the current directions in adjacent second conductive structures can also be opposite, and the electromagnetic induction generated by the currents flowing in opposite directions will partially offset each other, thereby achieving the purpose of reducing the loop stray inductance. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Hereinafter, the present invention will be described in more detail based on embodiments and with reference to the accompanying drawings.

[0023] Figure 1 is an electrical schematic diagram of a power module based on an integrated gate-commutated thyristor in one embodiment of the present invention;

[0024] Figure 2 and Figure 3 is a schematic diagram of a three-dimensional structure of a power module based on an integrated gate-commutated thyristor in one embodiment of the present invention;

[0025] Figure 4 1 is a front view of a power module based on an integrated gate-commutated thyristor according to an embodiment of the present invention (the third power string is not shown in the figure)

[0026] Figure 5 yes Figure 2 A schematic diagram of the three-dimensional structure of the power subunit shown;

[0027] Figure 6 yes Figure 4 A front view of the first insulating block shown;

[0028] Figure 7 yes Figure 4 A front view of the first guide post is shown.

[0029] Reference numerals:

[0030] 100-a first power string; 110-an IGCT device;

[0031] 200-a second power string; 210-a diode device;

[0032] 400-frame; 410-upper pressure plate; 420-lower pressure plate; 430-power supply; 440-isolation transformer; 450-support column;

[0033] 500-resistance-capacitance absorption unit; 510-copper busbar; 520-absorption resistor; 530-absorption capacitor; 540-voltage-equalizing resistor; 501-insulation board; 502-tank body;

[0034] 600-power subunit;

[0035] 120-central force mechanism; 121-first stud; 122-first guide post; 123-second stud; 124-second guide post;

[0036] 130 - second insulating block; 131 - first insulating block; 1311 - groove; 1312 - metal pad;

[0037] 132-Metal block. DETAILED DESCRIPTION

[0038] The present invention will be further described below in conjunction with the accompanying drawings.

[0039] The present invention provides a power module based on an integrated gate commutated thyristor. The power module may be a circuit breaker. More specifically, the power module is an H-bridge type circuit breaker.

[0040] like Figure 1 As shown, the circuit breaker requires four-quadrant operation, but the current integrated gate commutated thyristor (IGCT) does not have reverse withstand voltage capability, so a reverse blocking diode needs to be added, and the reverse cutoff capability of the diode is utilized at the same time, with the IGCT as the branch node, to form an H-bridge circuit. In the circuit, the RC absorption part is connected in parallel at both ends of the IGCT, and the MOV is connected in parallel at both ends of the entire electrical circuit. Therefore, the power module of the present invention has an IGBT device and a diode device, wherein the turn-off current of a single IGCT device can reach 5KA.

[0041] like Figure 1 The circuit topology shown is a bidirectional current-carrying circuit breaker loop. The shutdown current of a single device reaches the nominal limit of the device, and the stray inductance of the loop has a significant effect on the shutdown capability of the device. Therefore, the inventive concept of the present invention is to reduce the stray inductance of the loop between devices.

[0042] Specifically, if Figure 2-5 As shown, the power module of the present invention includes a frame 400 and at least two power sub-units 600. The frame 400 includes an upper pressing plate 410 and a lower pressing plate 420, and the at least two power sub-units 600 are arranged between the upper pressing plate 410 and the lower pressing plate 420. A support column 450 is arranged between the upper pressing plate 410 and the lower pressing plate 420, and the support column 450 extends along the Z-axis direction to define a space between the upper pressing plate 410 and the lower pressing plate 420 for installing a power string.

[0043] The power subunit 600 is along Figure 2 The Z-axis direction is shown as stacked in sequence, and the present invention is described in detail below by taking stacking 5 power subunits 600 as an example.

[0044] Each power subunit 600 includes a first device 110 and at least two second device assemblies; wherein the first device and the at least two second device assemblies are electrically connected through a first conductive structure 111 and a second conductive structure 112. Adjacent power subunits 600 are arranged in a stacking direction ( Figure 2 In other words, the adjacent power subunits 600 are placed in opposite directions, so that the current directions in the adjacent first conductive structures 111 are opposite, and the current directions in the adjacent second conductive structures 112 are also opposite. Since the electromagnetic inductions generated by the currents flowing in opposite directions will partially cancel each other out, the purpose of reducing the loop stray inductance can be achieved.

[0045] It can be understood that the first conductive structure 111 and the second conductive structure 112 can both be conductive bodies such as copper busbars.

[0046] First, the first device 110 is an integrated gate-commutated thyristor (IGCT) device, hereinafter referred to as the IGCT device 110 .

[0047] like Figure 2 and 3 As shown in FIG. 1 , a circuit breaker having five power subunits 600 is shown. Therefore, the number of IGCT devices 110 is five. Figure 2 As shown, the first devices 110 are stacked and pressed together in sequence in the Z-axis direction, so that five pressed together first devices 110 constitute a first power string 100 .

[0048] exist Figure 2 The adjacent IGCT devices 110 in the Z-axis direction are symmetrical to each other, that is, they are placed in reverse. Specifically, if a certain IGCT device 110 is placed with the anode at the bottom and the cathode at the top, then the IGCT device 110 located on the upper layer is placed with the anode at the top and the cathode at the bottom, and the IGCT device 110 located on the lower layer is also placed with the anode at the top and the cathode at the bottom, and so on.

[0049] In some embodiments, a first insulating block 131 is disposed between adjacent IGCT devices 110. Figure 6 As shown, a groove 1311 surrounding the circumference of the first insulating block 131 is disposed on the side wall thereof, and metal pads 1312 for contacting the surface of the IGCT device 110 are disposed at both ends of the first insulating block 131 .

[0050] Among them, the first insulating block 131 is made of glass fiber with CTI>600 to improve its insulation ability and reduce the height size. The metal pad 1312 is embedded in the end of the first insulating block 131 and protrudes 3 to 5 mm from the surface of the first insulating block 131. The metal pad 1312 can be an aluminum alloy, and its surface has better processing performance than epoxy material, and can be processed to a higher flatness and roughness. For example, the surface of the metal pad 1312 is finely processed (flatness is less than 0.006, roughness is less than 0.8) to ensure uniform contact of the crimping surface, and is electroplated or anodized to further improve its surface finish.

[0051] While ensuring the insulation performance, the metal spacer 1312 can make the contact of the crimping surface of the IGCT device 110 more uniform.

[0052] The second device assembly is described below by taking the example that each power subunit 600 includes two second device assemblies.

[0053] like Figure 5As shown, the two second device assemblies are respectively located on the left and right sides of the IGCT device 110 , and the two second device assemblies are symmetrically arranged with respect to the first device 110 .

[0054] Among them, five pressed together second device assemblies constitute one second power string 200, and another five pressed together second device assemblies constitute another second power string 200. The two second power strings 200 are located on the left and right sides of the first power string 100, respectively.

[0055] The second device assembly includes two second devices, and the second devices may be diode devices 210 . Therefore, each second power string 200 has 10 diode devices 210 .

[0056] The two diode devices 210 in the second device assembly are arranged in the stacking direction of the power subunit 600 ( Figure 2 Specifically, if a diode device 210 is placed with the anode at the bottom and the cathode at the top, then the diode device 210 located on the upper layer (or lower layer) is placed with the anode at the top and the cathode at the bottom.

[0057] The two diode devices 210 in one second power string 200 and the corresponding two diode devices 210 in another second power string 200 are electrically connected to a corresponding one IGCT device 110 in the first power string 100 , respectively.

[0058] like Figure 5 As shown, one of the power subunits 600 is shown, which includes an IGCT device 110 and two diode device assemblies located on the left and right sides thereof. The diode device assemblies on the left and right sides of the IGCT device 110 each include two upper and lower diode devices 210. In addition, a metal block 132 is provided between the two diode devices 210, and the metal block 132 may be a copper block.

[0059] The IGCT device 110 is electrically connected to the diode device 210 in the diode device assembly on its left side through the first conductive structure 111 , and is electrically connected to the diode device 210 in the diode device assembly on its right side through the second conductive structure 112 .

[0060] like Figure 5 As shown, there is an angle between the first conductive structure 111 and the second conductive structure 112 . Specifically, the angle is an acute angle, such as 60°, to ensure that the loop is shortened under constraints such as installation and processing.

[0061] In addition, the spacing between adjacent first conductive structures 111 and the spacing between adjacent second conductive structures 112 need to be as small as possible to shorten the loop.

[0062] Since adjacent IGCT devices 110 are placed in opposite directions and adjacent diode devices 210 are also placed in opposite directions, the current directions in adjacent first conductive structures 111 are opposite, and the current directions in adjacent second conductive structures 112 are also opposite, thereby reducing loop stray inductance.

[0063] In addition, the interval between the first power string 100 and the two second power strings 200 needs to be as small as possible under the constraints of production, assembly, electrical clearance, etc. For example, the two second power strings 200 are symmetrically arranged with respect to the first power string 100 .

[0064] Furthermore, if Figure 2 As shown, the power module of the present invention further includes a RC absorption unit 500, which is disposed on an insulating plate 501 at the side of the IGCT device 110 and connected in parallel with the IGCT device 110. The distance between the RC absorption unit 500 and the corresponding IGCT device 110 should be as small as possible to shorten the loop and thus reduce the loop stray inductance.

[0065] Specifically, insulating plates 501 are respectively provided on both sides of the IGCT device 110, so the RC absorption units 500 are respectively provided on both sides of the IGCT device 110, which can reduce the size of the entire component while shortening the length of this part of the loop and reducing the stray inductance of the loop.

[0066] There are at least two RC absorption units 500 . Since the number of the power subunits 600 is five, five RC absorption units 500 are used for description below.

[0067] like Figure 2 and 3 As shown, insulating plates 501 are respectively provided on both sides of the IGCT device 110. Figure 2 As shown, three RC absorbing units 500 are arranged on the insulating plate 501 on the left side of the IGCT device 110, and the three RC absorbing units 500 are stacked in the Z-axis direction; Figure 3 As shown, two RC absorption units 500 are arranged on the insulating plate 501 on the right side of the IGCT device 110 , and the two RC absorption units 500 are stacked in the Z-axis direction.

[0068] like Figure 2 As shown, a groove 502 is provided on the portion of the insulating plate 501 between two adjacent RC absorption units 500 to increase the creepage distance.

[0069] Preferably, the RC absorption units 500 are connected in parallel with the corresponding IGCT devices 110 through the third conductive structures with bending angles. The current direction in the third conductive structures is also opposite, so the loop stray inductance can be further eliminated.

[0070] The third conductive structure may be a copper busbar 510 , which may be made of red copper, and can eliminate stress caused by the height difference between different power strings and avoid deformation of the crimping surface of the copper busbar 510 due to stress.

[0071] In addition, the bending angle of the copper busbar 510 is an obtuse angle (the angle value is greater than 130°), which is used to prevent the copper busbar 510 from having a right angle and thus increasing the stray inductance of the loop.

[0072] Taking one of the RC absorption units 500 as an example, it includes an absorption resistor 520, an absorption capacitor 530 and a voltage-equalizing resistor 540 connected to the copper bus 510 respectively. The absorption resistor 520, the absorption capacitor 530 and the voltage-equalizing resistor 540 are connected to the copper bus 510 respectively. Figure 2 The X-axis directions are shown as being arranged sequentially.

[0073] In addition, the frame 400 is also provided with an isolation transformer 440 and a power supply 430 for supplying power to the IGCT device 110 , so that the isolation transformer 440 and the power supply 430 can be isolated in the power module.

[0074] In some embodiments, a central force applying mechanism 120 is also included for pressing the power subunits 600 together. Each of these will be described below.

[0075] The first power string 100 also includes a central force mechanism 120, wherein the central force mechanism 120 is used to apply pressure to the IGCT device 110; a second insulating block 130 is also provided between the IGCT device 110 and the central force mechanism 120, which is used to transfer the pressure applied by the central force mechanism 120 to the IGCT device 110.

[0076] The contact area between the central force applying mechanism 120 and the second insulating block 130 is smaller than the contact area between the second insulating block 130 and the IGCT device 110 , so as to ensure that the pressure is evenly distributed when being transmitted to the surface of the IGCT device 110 .

[0077] Specifically, the central force applying mechanism 120 includes a first stud 121 and a first guide post 122 . The first stud 121 is disposed above the topmost IGCT device 110 , and the first guide post 122 is disposed below the bottommost IGCT device 110 .

[0078] like Figure 7As shown, the first guide pillar 122 is constructed as a structure with a large first end area and a small second end area, and the first end area of ​​the first guide pillar 122 is greater than or equal to the crimping area of ​​the IGCT device 110. The first end of the first guide pillar 122 is an end close to the IGCT device 110, and the second end is an end away from the IGCT device 110. For example, the diameter of the first end of the first guide pillar 122 is about 90 mm, and the diameter of the second end of the first guide pillar 122 is 50 mm to 60 mm.

[0079] The first stud 121 passes through the upper pressing plate 410 and contacts the upper end of the second insulating block 130, while the lower end of the second insulating block 130 contacts the upper end of the topmost IGCT device 110. At the lower end, one end (i.e., the small end) of the first guide pillar 122 contacts the surface of the lower pressing plate 420, and the other end (i.e., the large end) of the first guide pillar 122 contacts the second insulating block 130, which contacts the IGCT device 110 at the bottom.

[0080] Therefore, the first stud 121 is tightened downward by a torque wrench (torque is 50-60 N.m), so that the first stud 121 can be pressed against the second insulating block 130 and exert downward pressure, while the first guide column 122 at the bottom presses the second insulating block 130 upward and exerts upward pressure, thereby providing the required crimping force to the IGCT device 110.

[0081] Preferably, the first stud 121 is a ball head stud, whose end surface area is much smaller than the end surface area of ​​the second insulating block 130, so that the contact area between the first stud 121 and the second insulating block 130 is much smaller than the contact area between the second insulating block 130 and the topmost IGCT device 110.

[0082] Preferably, the axis of the first stud 121 coincides with the axis of the IGCT device 110 , and the first stud 121 is located at the center of the IGCT device 110 , thereby enabling the first stud 121 to achieve central force application to ensure that the pressure can be evenly distributed when transmitted to the surface of the IGCT device 110 .

[0083] Similarly, if Figure 5 As shown, the second power string 200 also has a central force mechanism 120 , which includes a second stud 123 and a second guide column 124 . The second stud 123 is disposed above the topmost diode device 210 , and the second guide column 124 is disposed below the bottommost diode device 210 .

[0084] The second stud 123 may be a ball stud, and its configuration is the same as that of the first stud 121 , which will not be described in detail herein.

[0085] The second guide pillar 124 is different from the first guide pillar 122 in that the second guide pillar 124 can be set to a columnar structure. Since the crimping requirement of the diode device 210 is lower than the crimping requirement of the IGCT device 110, the second guide pillar 124 in the second power string 200 can be set to a columnar structure that is easier to process.

[0086] The same thing is that a second insulating block 130 is disposed between the central force applying mechanism 120 and the second guide pillar 124 .

[0087] Although the present invention has been described with reference to preferred embodiments, various modifications may be made thereto and parts thereof may be replaced by equivalents without departing from the scope of the present invention. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there are no structural conflicts. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A power module based on an integrated gate-commutated thyristor, characterized in that: It comprises at least two stacked power subunits, each of which comprises a first device and at least two second device assemblies; The first device and at least two second devices are electrically connected through a first conductive structure and a second conductive structure respectively; Wherein, in the stacking direction of the power subunits, the adjacent power subunits are symmetrical to each other, so that the current directions in the adjacent first conductive structures are opposite, and the current directions in the adjacent second conductive structures are also opposite; An angle is formed between the first conductive structure and the second conductive structure; It also includes at least two RC absorption units, each of which is disposed on an insulating plate located on a side of the power subunit, and each of which is electrically connected to the corresponding first device through a third conductive structure having a bending angle; Wherein, in the stacking direction of the power subunits, the current directions in the adjacent third conductive structures are opposite; A slot is provided on the portion of the insulating plate between two adjacent RC absorption units, and the slot is used to increase the creepage distance; The second device assembly comprises: second devices, which are at least two; and a metal block disposed between two of the second devices; The two second devices are symmetrical to each other in the stacking direction of the power subunit.

2. The power module based on integrated gate-commutated thyristor according to claim 1, characterized in that: The bending angle of the third conductive structure is an obtuse angle.

3. The power module based on integrated gate-commutated thyristor according to claim 1, characterized in that: A first insulating block is arranged between adjacent first components, and metal pads for contacting the surface of the first component are respectively arranged at two opposite ends of the first insulating block.

4. The power module based on integrated gate-commutated thyristor according to claim 3, characterized in that: A groove surrounding the circumference of the first insulating block is arranged on the side wall of the first insulating block.

5. The power module based on integrated gate-commutated thyristor according to claim 1, characterized in that: It also includes a frame, in which the power subunit is arranged; the frame is also provided with an isolation transformer and a power supply for supplying power to the first device.

6. The power module based on integrated gate-commutated thyristor according to claim 1, characterized in that: Also included is a central force mechanism for crimping the power subunits together.

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