Power device double-string crimping structure for converter valve
By setting IGBTs and diodes as independent voltage strings and connecting them through supporting structures, a compact electrical circuit is formed, which solves the problem of mismatched pressure surfaces and achieves uniform distribution of pressure force on power devices and cost reduction.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- TBEA SUNOASIS
- Filing Date
- 2025-04-23
- Publication Date
- 2026-05-05
AI Technical Summary
Traditional press-fit power device packaging methods struggle to address the mismatch between press surfaces of different shapes and sizes, resulting in uneven press-fit forces that affect the normal operation of converter valves and increase manufacturing costs.
The IGBT and diode voltage strings are set up independently and connected by supporting structural components to form a double-string voltage connection structure. The mechanical strength and conductivity are improved by using aluminum alloy heat sinks and carbon steel materials, forming a compact electrical circuit.
This ensures uniform distribution of crimping force on the crimping surface of power devices, reduces the amount of raw materials used in heat sinks, lowers the manufacturing cost of converter valves, and improves crimping effect and operational reliability.
Smart Images
Figure CN224204964U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of flexible DC power transmission, specifically to a double-string press-fit structure for power devices used in converter valves. Background Technology
[0002] Flexible DC transmission technology is a stable, reliable, and efficient new power transmission method suitable for scenarios such as renewable energy grid integration, islanded power supply, and urban power grid interconnection. It is an important supporting technology for the construction of future smart grids. The converter valve is a key device in a flexible DC transmission system. To cope with the complex and diverse power supply and grid usage scenarios, the selection of key components within the converter valve, namely power devices, is becoming increasingly diverse. Press-fit insulated-gate bipolar transistors (IGBTs) and press-fit diodes are two commonly used power devices in converter valves for current conversion, and they are usually used together in a parallel configuration with opposite polarities. Traditional press-fit power device packaging encapsulates the IGBT and diode into a single component. Taking the 4.5kV / 2kA class device, which is widely used in flexible DC transmission projects, as an example, several power devices and heat sinks are staggered and stacked in alignment and press-fitted into a series of press-fit components, which are then installed inside the converter valve. The pressing surfaces of multiple power devices are all the same in shape and size, which can ensure that the pressing force is evenly distributed on the pressing surfaces of the power devices, resulting in a good pressing effect.
[0003] However, with the changing requirements for power device selection in converter valves, traditional press-fit power device packaging methods are insufficient to meet the complex and diverse requirements. Many press-fit IGBTs and diodes have begun to adopt separate packaging designs with different press-fit surface shapes and sizes. When applying converter valves, it is necessary to press-fit the separately packaged IGBTs and diodes into a series of press-fit components, which leads to the problem of mismatched power device press-fit surfaces. The quality of the press-fit directly affects whether the power device can operate well and normally. Mismatched power device press-fit surfaces can easily cause uneven press-fit forces on the press-fit surfaces, posing a significant challenge to the press-fit process.
[0004] Existing technologies address the mismatch between the crimping surfaces of power devices primarily by increasing the thickness of the heat sink between the mismatched surfaces to improve its strength and thus disperse uneven pressure. However, this method leads to an increase in the amount of heat sink material used and the volume of the converter valve, resulting in wasted manufacturing costs. Furthermore, it does not completely eliminate the problem of mismatch between the crimping surfaces of adjacent power devices, and the crimping effect is still difficult to achieve the level of crimping identical power devices, posing a certain risk to the normal operation of the converter valve. Utility Model Content
[0005] The purpose of this invention is to provide a dual-string press-fit structure for power devices used in converter valves, in order to solve the problem of mismatched press-fit surfaces during the packaging of press-fit power devices when different types of press-fit power devices are selected in the prior art.
[0006] To achieve the above objectives, the present invention adopts the following technical solution:
[0007] In a first aspect, a dual-string press-fit structure for power devices used in a converter valve includes: IGBT press-fit string, diode press-fit string, stacked busbar, first copper busbar, second copper busbar, third copper busbar, equalizing resistor, piping assembly, and supporting structure.
[0008] The IGBT voltage string is composed of several IGBTs and a first heat sink stacked alternately. The diode voltage string is composed of several diodes and a second heat sink stacked alternately. The IGBT voltage strings and diode voltage strings are parallel to each other and connected by a supporting structure to form a double-string press-fit structure. The second heat sink has a protruding structure located on the bottom outer side of the double-string press-fit structure. The first copper busbar and the voltage equalizing resistor are mounted on the protruding structure. The second copper busbar is mounted between the first heat sink and the second heat sink and corresponds to the mounting position of the first copper busbar. The third copper busbar and the stacked busbar are sequentially stacked on the side of the double-string press-fit structure. The third copper busbar corresponds to the mounting position of the first copper busbar. The piping assembly connects to the adjacent first heat sink and to the adjacent second heat sink.
[0009] In some embodiments, the IGBT string includes a plurality of IGBTs, a first lower pressure plate, a first insulating pressure block, a second insulating pressure block, a first conical pressure block, a first ball-head guide rod, a first disc spring, a first upper pressure plate, a first screw, and a plurality of first heat sinks; the plurality of IGBTs and the plurality of first heat sinks are alternately stacked to form an IGBT stacked structure, with a first heat sink provided on both sides of each IGBT, and a first heat sink at both ends of the IGBT stacked structure; the first insulating pressure block and the first lower pressure plate are sequentially stacked on the first heat sink at one end of the IGBT stacked structure, and the second insulating pressure block, the first conical pressure block, the first ball-head guide rod, the first disc spring, and the first upper pressure plate are sequentially stacked on the first heat sink at the other end of the IGBT stacked structure; the first screw connects the first lower pressure plate and the first upper pressure plate.
[0010] In some embodiments, the diode voltage string includes a plurality of diodes, a second lower pressure plate, a third insulating pressure block, a fourth insulating pressure block, a second conical pressure block, a second ball-head guide rod, a second disc spring, a second upper pressure plate, a second screw, and a plurality of second heat sinks; the plurality of diodes and the plurality of second heat sinks are alternately stacked to form a diode stack structure, with a second heat sink provided on both sides of each diode, and the diode stack structure having second heat sinks at both ends; the third insulating pressure block and the second lower pressure plate are sequentially stacked on the second heat sink at one end of the diode stack structure, and the fourth insulating pressure block, the second conical pressure block, the second ball-head guide rod, the second disc spring, and the second upper pressure plate are sequentially stacked on the second heat sink at the other end of the diode stack structure; the second screw connects the second upper pressure plate and the second lower pressure plate.
[0011] In some embodiments, the support structure is disposed between the first lower pressure plate and the second lower pressure plate, and between the first upper pressure plate and the second upper pressure plate.
[0012] In some embodiments, the first lower pressure plate, the first conical pressure block, the first ball-head guide rod, and the first screw are made of carbon steel.
[0013] In some embodiments, the second lower pressure plate, the second conical pressure block, the second ball-head guide rod, and the second screw are made of carbon steel.
[0014] In some embodiments, the first and second heat sinks are made of aluminum alloy, and their bases are both thick plates.
[0015] In some embodiments, the protruding structures are symmetrically arranged on the bottom outer side of the double-string crimping structure, and each protruding structure is equipped with the first copper busbar and a voltage equalizing resistor, wherein the first copper busbar is an L-shaped copper busbar.
[0016] In some embodiments, the second copper busbar is provided with two parts inside the double-string crimping structure, which are respectively connected to the first heat sink and the second heat sink corresponding to the symmetrically arranged protruding structure.
[0017] In some embodiments, the third copper busbar has two parts on the outer surface of the double-string crimped structure, which are respectively connected to the first heat sink and the second heat sink corresponding to the symmetrically arranged protruding structure.
[0018] Compared with the prior art, the present invention has the following beneficial effects:
[0019] This invention independently sets up IGBT and diode voltage strings, respectively. The IGBT and diode voltage strings are parallel to each other and connected by a supporting structure to form a double-string press-fit structure. Each voltage string contains only power devices with matching press-fit surfaces, solving the problem of mismatched press-fit surfaces of power devices in the converter valve and ensuring uniform distribution of press-fit force on the press-fit surfaces of the power devices. In addition, through this design, the IGBT and diode voltage strings are press-fitted separately without interference. Compared with the existing technology that thickens the heat sink to address the mismatch of press-fit surfaces of adjacent power devices, this invention reduces the material usage of the heat sink, and the resulting double-string press-fit structure is compact, reducing the manufacturing cost of the converter valve.
[0020] Furthermore, the first and second heat sinks made of aluminum alloy are stacked alternately with IGBTs and diodes to form low-impedance conductive paths. At the same time, the adjacent heat sinks are connected by a pipeline assembly to form a cooling channel, which can reduce the temperature rise of the power devices.
[0021] Furthermore, the IGBT voltage string is isolated from the high-voltage components by the first and second insulating blocks, and its mechanical strength and overall structural rigidity are improved by the first lower pressure plate, the first conical pressure block, the first ball-head guide rod, and the first screw made of carbon steel, ensuring uniform pressure transmission within the IGBT voltage string. Similarly, the diode voltage string is isolated from the high-voltage components by the third and fourth insulating blocks, and its mechanical strength and overall structural rigidity are improved by the second lower pressure plate, the second conical pressure block, the second ball-head guide rod, and the second screw made of carbon steel, ensuring uniform pressure transmission within the diode voltage string.
[0022] Furthermore, the supporting structural members are arranged between the first lower pressure plate and the second lower pressure plate, and between the first upper pressure plate and the second upper pressure plate, which can form a rigid frame to prevent structural deformation.
[0023] Furthermore, the protruding structure is equipped with a first copper busbar and a voltage equalizing resistor, which can form a complete electrical circuit for the converter valve crimping assembly, allowing the double-string crimping structure to be installed inside the converter valve and complete its converter function. Attached Figure Description
[0024] Figure 1 This is a front view of a dual-string press-fit structure for a power device used in a converter valve, as provided in Embodiment 1.
[0025] Figure 2 This is a schematic diagram of the IGBT string compression structure provided in Example 1;
[0026] Figure 3 This is a schematic diagram of the diode voltage string structure provided in Embodiment 1;
[0027] Figure 4This is a schematic diagram of the back structure of a dual-string press-fit structure (excluding stacked busbars) for a power device used in a converter valve, provided in Embodiment 1.
[0028] Figure 5 This is a schematic diagram of the back structure of a dual-string press-fit structure (including stacked busbars) for a power device used in a converter valve, provided in Embodiment 1.
[0029] In the diagram, 1. IGBT voltage string; 2. Diode voltage string; 3. Laminated busbar; 4. First copper busbar; 5. Second copper busbar; 6. Third copper busbar; 7. Equalizing resistor; 8. Piping assembly; 9. Support structure; 101. First lower pressure plate; 102. First insulating pressure block; 103. Second insulating pressure block; 104. First conical pressure block; 105. First ball-head guide rod; 106. First disc spring; 107. First upper pressure plate; 108. First screw; 109. First heat sink; 110. IGBT; 201. Second lower pressure plate; 202. Third insulating pressure block; 203. Fourth insulating pressure block; 204. Second conical pressure block; 205. Second ball-head guide rod; 206. Second disc spring; 207. Second upper pressure plate; 208. Second screw; 209. Second heat sink; 210. Diode. Detailed Implementation
[0030] In the following description, only certain exemplary embodiments are briefly described. The described embodiments can be modified in various ways without departing from the spirit or scope of this invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.
[0031] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed or operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.
[0032] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.
[0033] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.
[0034] The embodiments of this utility model will now be described in detail with reference to the accompanying drawings.
[0035] Example 1
[0036] like Figure 1 As shown, this embodiment provides a dual-string press-fit structure for power devices used in a converter valve, including: IGBT press-fit string 1, diode press-fit string 2, stacked busbar 3, first copper busbar 4, second copper busbar 5, third copper busbar 6, equalizing resistor 7, pipeline assembly 8, and supporting structure 9, wherein two first copper busbars 4, two second copper busbars 5, two third copper busbars 6, and two equalizing resistors 7 are provided;
[0037] like Figure 2 As shown, the IGBT string 1 includes a first lower pressure plate 101, a first insulating pressure block 102, a second insulating pressure block 103, a first conical pressure block 104, a first ball-head guide rod 105, a first disc spring 106, a first upper pressure plate 107, four first screws 108, five first heat sinks 109, and four IGBTs 110. The four IGBTs 110 and the five first heat sinks 109 are alternately stacked to form an IGBT stacked structure. Each IGBT... Both sides of 110 are provided with first heat sinks 109, and both ends of the IGBT stacked structure are also provided with first heat sinks 109. The components are stacked in the following order from right to left: first lower pressure plate 101, first insulating pressure block 102, IGBT stacked structure, second insulating pressure block 103, first conical pressure block 104, first ball head guide rod 105, first disc spring 106, and first upper pressure plate 107. After stacking, a hydraulic press is used to apply axial pressure along the left and right directions from the center of the first lower pressure plate 101 and the first upper pressure plate 107 at both ends of the IGBT stack 1 to press the IGBT stack 1. In the pressed state, four first screws 108 are used to pass through the four corners of the first lower pressure plate 101 and the first upper pressure plate 107 along the left and right directions to tighten and fix them. Finally, the pressure of the hydraulic press is released, and the assembly of the IGBT stack 1 is completed.
[0038] like Figure 3As shown, the diode voltage string 2 includes a second lower pressure plate 201, a third insulating pressure block 202, a fourth insulating pressure block 203, a second conical pressure block 204, a second ball-head guide rod 205, a second disc spring 206, a second upper pressure plate 207, a second screw 208 with four components, a second heat sink 209 with five components, and four diodes 210. The four diodes 210 and the five second heat sinks 209 are alternately stacked to form a diode stack structure. Each diode 210 has a second heat sink 209 on both sides, and both ends of the diode stack structure are second heat sinks 209. The components are stacked sequentially from right to left in the following order: second lower pressure plate 201, third insulating pressure block 202, diode stacked structure, fourth insulating pressure block 203, second conical pressure block 204, second ball-head guide rod 205, second disc spring 206, and second upper pressure plate 207. After stacking, a hydraulic press is used to apply axial pressure along the left and right directions from the center positions of the second lower pressure plate 201 and the second upper pressure plate 207 at both ends of the diode string 2 to press it tight. In the pressed state, four second screws 208 are used to pass through the four corners of the second lower pressure plate 201 and the second upper pressure plate 207 in the left and right directions to tighten and fix it. Finally, the pressure of the hydraulic press is released, thus completing the assembly of the diode string 2.
[0039] Therefore, through the above-mentioned process, IGBT voltage string 1 and diode voltage string 2 are assembled separately without interference. Furthermore, each voltage string contains only one type of power device, either an IGBT 110 or a diode 210, and their pressing surfaces have the same shape and size. This ensures that the pressing force is evenly distributed on the pressing surface of the power device, thus guaranteeing the pressing effect.
[0040] The first lower pressure plate 101, the first conical pressure block 104, the first ball-head guide rod 105, the first screw 108, the second lower pressure plate 201, the second conical pressure block 204, the second ball-head guide rod 205, and the second screw 208 are all made of carbon steel. Their function is to ensure the transmission effect of internal pressure of IGBT voltage string 1 and diode voltage string 2, as well as the rigidity of the overall structure of each voltage string. The first heat sink 109 and the second heat sink 209 are both made of aluminum alloy, and the appearance of the base is thick plate, which can conduct electricity and dissipate heat inside each voltage string.
[0041] like Figure 4 and Figure 5As shown, the IGBT voltage string 1 and the diode voltage string 2 are parallel to each other and are fixed by two supporting structural members 9 to form a double-string pressure connection structure. One supporting structural member is located between the first lower pressure plate 101 and the second lower pressure plate 201, and the other is located between the first upper pressure plate 107 and the second upper pressure plate 207. The IGBT voltage string 1 is installed directly above the diode voltage string 2. The conduit assembly 8 is installed on the front of the entire double-string pressure connection structure. The conduit assembly 8 is connected to the adjacent first heat sink 109 and the adjacent second heat sink 209.
[0042] The second heat sink 209 has a protruding structure, which is symmetrically arranged on the bottom outer side of the double-string crimped structure. Each protruding structure is equipped with the first copper busbar 4 and an equalizing resistor 7. The first copper busbar 4 is an L-shaped copper busbar. The first copper busbar 4 and the equalizing resistor 7 are mounted on the protruding structure. Two second copper busbars 5 are disposed inside the double-string crimped structure and are respectively connected to the first heat sink 109 and the second heat sink 209 corresponding to the symmetrically arranged protruding structures. The third copper busbar 6 and the stacked busbar 3 are sequentially stacked on the back side of the double-string crimped structure. The two third copper busbars 6 are respectively connected to the first heat sink 109 and the second heat sink 209 corresponding to the symmetrically arranged protruding structures. The first copper busbar 4, the second copper busbar 5, the third copper busbar 6, the stacked busbar 3, and the equalizing resistor 7 are all conductive components of the double-string crimped structure, together forming a complete electrical circuit of the double-string crimped structure.
[0043] This embodiment separates the crimping of power devices (i.e., IGBTs and diodes) with different crimping surface shapes and sizes. Each crimp string contains only power devices with mutually compatible crimping surfaces, fundamentally avoiding the problem of mismatched crimping surfaces of power devices in the converter valve. This ensures uniform distribution of crimping force on the crimping surfaces of the power devices and good crimping effect. IGBT crimp string 1 and diode crimp string 2 are crimped separately without interference, and each crimp string is small in weight and volume, making assembly and maintenance convenient. Compared with the existing technology that uses thickened heat sinks to address the mismatch of crimping surfaces between adjacent power devices, this reduces the amount of heat sink material used, and the overall crimping structure is compact, reducing the overall manufacturing cost of the converter valve.
[0044] Example 2
[0045] This embodiment provides a dual-string press-fit structure for power devices used in a converter valve. Unlike the first embodiment, the first heat sink 109 in the IGBT press-fit string 1 is provided in three pieces, and the IGBT is provided in two pieces. The two IGBTs 110 and the three first heat sinks 109 are alternately stacked to form an IGBT stack structure. The first heat sink 109 is provided on both sides of each IGBT 110, and the first heat sink 109 is provided at both ends of the IGBT stack structure.
[0046] In the diode voltage series 2, three second heat sinks 209 are provided, and two diodes are provided. The two diodes 210 and the three second heat sinks 209 are stacked alternately to form a diode stack structure. Each diode 210 has a second heat sink 209 on both sides, and the two ends of the diode stack structure are both second heat sinks 209.
[0047] As is known from common technical knowledge, this utility model can be implemented through other embodiments that do not depart from its spirit or essential characteristics. Therefore, the above-disclosed embodiments are merely illustrative in all respects and are not the only ones. All changes within the scope of this utility model or equivalent to this utility model are included in this utility model.
Claims
1. A double-string press-fit structure for power devices used in converter valves, characterized in that, include: IGBT voltage string, diode voltage string, multilayer busbar, first copper busbar, second copper busbar, third copper busbar, equalizing resistor, piping assembly and supporting structure; The IGBT voltage string is composed of several IGBTs and a first heat sink stacked alternately. The diode voltage string is composed of several diodes and a second heat sink stacked alternately. The IGBT voltage strings and diode voltage strings are parallel to each other and connected by a supporting structure to form a double-string press-fit structure. The second heat sink has a protruding structure located on the bottom outer side of the double-string press-fit structure. The first copper busbar and the voltage equalizing resistor are mounted on the protruding structure. The second copper busbar is mounted between the first heat sink and the second heat sink and corresponds to the mounting position of the first copper busbar. The third copper busbar and the stacked busbar are sequentially stacked on the side of the double-string press-fit structure. The third copper busbar corresponds to the mounting position of the first copper busbar. The piping assembly connects to the adjacent first heat sink and to the adjacent second heat sink.
2. The power device double-string press-fit structure for a converter valve according to claim 1, characterized in that, The IGBT string includes several IGBTs, a first lower pressure plate, a first insulating pressure block, a second insulating pressure block, a first conical pressure block, a first ball-head guide rod, a first disc spring, a first upper pressure plate, a first screw, and several first heat sinks; The IGBTs and the first heat sinks are alternately stacked to form an IGBT stacked structure. Each IGBT has a first heat sink on both sides, and the IGBT stacked structure has a first heat sink at both ends. The first insulating pressure block and the first lower pressure plate are stacked on the first heat sink at one end of the IGBT stacked structure in sequence. The second insulating pressure block, the first conical pressure block, the first ball-head guide rod, the first disc spring, and the first upper pressure plate are stacked on the first heat sink at the other end of the IGBT stacked structure in sequence. The first screw connects the first lower pressure plate and the first upper pressure plate.
3. The power device double-string press-fit structure for a converter valve according to claim 2, characterized in that, The diode voltage string includes a plurality of diodes, a second lower pressure plate, a third insulating pressure block, a fourth insulating pressure block, a second conical pressure block, a second ball-head guide rod, a second disc spring, a second upper pressure plate, a second screw, and a plurality of second heat sinks; The diodes and the second heat sinks are alternately stacked to form a diode stack structure. Each diode has a second heat sink on both sides. The diode stack structure has a second heat sink at both ends. The third insulating pressure block and the second lower pressure plate are stacked on the second heat sink at one end of the diode stack structure. The fourth insulating pressure block, the second conical pressure block, the second ball-head guide rod, the second disc spring, and the second upper pressure plate are stacked on the second heat sink at the other end of the diode stack structure. The second screw connects the second upper pressure plate and the second lower pressure plate.
4. The power device double-string press-fit structure for a converter valve according to claim 3, characterized in that, The supporting structure is disposed between the first lower pressure plate and the second lower pressure plate, and between the first upper pressure plate and the second upper pressure plate.
5. The power device double-string press-fit structure for a converter valve according to claim 2, characterized in that, The first lower pressure plate, the first conical pressure block, the first ball-head guide rod, and the first screw are made of carbon steel.
6. The power device double-string press-fit structure for a converter valve according to claim 3, characterized in that, The second lower pressure plate, the second conical pressure block, the second ball-head guide rod, and the second screw are made of carbon steel.
7. The power device double-string press-fit structure for a converter valve according to claim 1, characterized in that, The first and second heat sinks are made of aluminum alloy, and their bases are both thick plates.
8. The power device double-string press-fit structure for a converter valve according to claim 1, characterized in that, The protruding structures are symmetrically arranged on the bottom outer side of the double-string crimping structure. Each protruding structure is equipped with the first copper busbar and a voltage equalizing resistor. The first copper busbar is an L-shaped copper busbar.
9. A double-string press-fit structure for power devices used in a converter valve according to claim 8, characterized in that, The second copper busbar has two parts inside the double-string crimping structure, which are respectively connected to the first heat sink and the second heat sink corresponding to the symmetrically arranged protruding structure.
10. A double-string press-fit structure for power devices in a converter valve according to claim 8, characterized in that, The third copper busbar has two parts on the outer surface of the double-string press-fit structure, which are respectively connected to the first heat sink and the second heat sink corresponding to the symmetrically arranged protruding structure.