Inverter substrate and inverter device

Abstract

To continue inverter control even if a part of a component experiences a short-circuit failure.SOLUTION: A first pattern 31 where a plurality of low-frequency capacitors 22 are mounted, a plurality of second patterns 32, which are electrically insulated from the first pattern 31 and mounted with at least one high-voltage-side switching element 20a and at least one high-frequency capacitor 21, and a plurality of short-circuit protection components 25 which are provided corresponding to each second pattern 32, electrically connected to the corresponding second pattern 32 and first pattern 31, are provided on a first surface of a substrate 41 of an inverter substrate 40. The first pattern 31 is connected to the DC bus, each short-circuit protection component 25 disconnects the electrical connection between the corresponding second pattern 32 and the first pattern 31 when the high-voltage-side switching element 20a or high-frequency capacitor 21 mounted on the corresponding second pattern 32 short-circuits.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to an inverter board and an inverter device. [Background technology]

[0002] Conventionally, an inverter device using a switching element, which is a power element, has been known as one type of power conversion device. For example, Non-Patent Document 1 discloses an inverter device in which a full-bridge inverter is provided for each winding of a multi-pole motor. The inverter device disclosed in Non-Patent Document 1 is an inverter for controlling a 10-pole motor, and has 30 inverter boards (= 10 poles × 3 phases). To reduce losses, multiple FET elements (e.g., 10 FET elements) are connected in parallel per switch of the full-bridge inverter. Furthermore, multiple high-frequency capacitors (e.g., 11 capacitors) are connected in parallel with the FET elements. This results in an extremely large number of components being mounted on one inverter board. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] Mohammad M. Qasim and 5 others, “Design and Optimization of an Inverter for a One-Megawatt Ultra-Light Motor Drive”, AIAA Aviation Forum 2023, Internet <https: / / dspace.mit.edu / bitstream / handle / 1721.1 / 150871 / 2023_AIAA_Paper_1MW_PE%5B99%5D.pdf?sequence=2&isAllowed=y> Summary of the Invention [Problem to be solved by the invention]

[0004] In an inverter device where multiple components are mounted on a single inverter board, many of the components are connected in parallel to the high-voltage DC bus. Therefore, if even one of these components experiences a short-circuit failure, the voltage on the high-voltage DC bus may drop to 0V, causing all inverter boards to stop functioning.

[0005] The present disclosure has been made in consideration of the above circumstances, and aims to provide an inverter board and an inverter device that can continue to perform inverter control even if some of the components fail due to a short circuit. [Means for solving the problem]

[0006] An inverter board according to one embodiment of the present disclosure is an inverter board on which a plurality of switching elements, a plurality of first capacitors, and a plurality of second capacitors having a smaller capacitance than the first capacitors are mounted, the inverter board comprising: a first pattern provided on a first surface of the board and on which a plurality of the first capacitors are mounted; a plurality of second patterns provided on the first surface of the board and electrically insulated from the first pattern and on which at least one switching element and at least one second capacitor are mounted; and a plurality of short-circuit protection components provided corresponding to each of the second patterns and electrically connecting the corresponding second pattern to the first pattern, wherein the first pattern is connected to a DC bus, and each of the short-circuit protection components cuts off the electrical connection between the corresponding second pattern and the first pattern when the switching element or the second capacitor mounted on the corresponding second pattern is short-circuited.

[0007] An inverter device according to one aspect of the present disclosure includes the inverter board described above and a control circuit that controls the switching elements. [Effects of the Invention]

[0008] According to the present disclosure, inverter control can be continued even if some of the components are short-circuited. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a diagram schematically illustrating a configuration example of an inverter circuit included in an inverter device according to a first embodiment of the present disclosure. [Figure 2] 2 is a diagram schematically illustrating a configuration example of an inverter circuit when the inverter device according to the first embodiment of the present disclosure is a three-phase inverter. FIG. [Figure 3] 1 is a diagram schematically illustrating a configuration example of a half-bridge circuit according to a first embodiment of the present disclosure. [Figure 4] 3A and 3B are diagrams illustrating an example of component mounting on a first surface of an inverter board according to a first embodiment of the present disclosure. [Figure 5] 3A and 3B are diagrams illustrating an example of component mounting on a second surface of the inverter board according to the first embodiment of the present disclosure. [Figure 6] 3A to 3C are diagrams illustrating an example of component mounting on a first pattern according to a first embodiment of the present disclosure. [Figure 7] 3A to 3C are diagrams illustrating an example of component mounting on a first pattern according to a first embodiment of the present disclosure. [Figure 8] 3A to 3C are diagrams illustrating an example of component mounting on a first pattern according to a first embodiment of the present disclosure. [Figure 9] FIG. 2 is a diagram showing an example of substrate mounting of a high-voltage side switching element and a low-voltage side switching element that configure one leg in the first embodiment of the present disclosure. [Figure 10] 2A and 2B are diagrams for explaining the arrangement of a short-circuit protection component according to the first embodiment of the present disclosure. [Figure 11] 2A and 2B are diagrams for explaining the arrangement of a short-circuit protection component according to the first embodiment of the present disclosure. [Figure 12] 2A and 2B are diagrams for explaining the arrangement of a short-circuit protection component according to the first embodiment of the present disclosure. [Figure 13] 2A and 2B are diagrams for explaining the arrangement of a short-circuit protection component according to the first embodiment of the present disclosure. [Figure 14] 10 is a diagram showing an example of component mounting on a first surface of an inverter board according to a second embodiment of the present disclosure. FIG. [Figure 15]FIG. 4 is a block diagram showing a schematic configuration of an inverter device according to a second embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0010] [First embodiment] Hereinafter, a first embodiment of an inverter board and an inverter device according to the present disclosure will be described with reference to the drawings. Fig. 1 is a diagram schematically illustrating an example of the configuration of an inverter circuit 1 included in an inverter device according to this embodiment. As shown in Fig. 1, the inverter circuit 1 according to this embodiment is a single-phase full-bridge inverter circuit including two half-bridge circuits 3 (3a, 3b). Hereinafter, when it is necessary to distinguish between the half-bridge circuits, they will be referred to as half-bridge circuits 3a, 3b, and when it is not necessary to distinguish between them, they will be simply referred to as half-bridge circuit 3. The same applies to other configurations.

[0011] Each half-bridge circuit 3 includes an upper arm 10a and a lower arm 10b. The upper arm 10 a is connected to the positive side of the DC bus 12 , and the lower arm 10 b is connected to the negative side of the DC bus 12 . A midpoint A between the upper arm 10a and the lower arm 10b of the half-bridge circuit 3a and a midpoint B between the upper arm 10a and the lower arm 10b of the half-bridge circuit 3b are connected via a load 5. The load 5 is, for example, an inductive load, and one example is a motor winding. In the half-bridge circuit 3, the upper arm 10a includes a plurality of high-voltage side switching elements 20a connected in parallel (see FIG. 3), and the lower arm 10b includes a plurality of low-voltage side switching elements 20b connected in parallel (see FIG. 3). The inverter circuit 1 controls the on / off of the switching elements 20 (see FIG. 3) provided in each arm 10, thereby converting a direct current into an alternating current and supplying it to the load 5. If the inverter device is a three-phase inverter, as shown in Figure 2, an inverter circuit 1 is provided for each phase, for a total of three inverter circuits 1. If the motor is a multi-pole motor, an inverter circuit 1 may be provided for each pole. In this case, a 10-pole three-phase motor requires 30 inverter circuits 1.

[0012] Fig. 3 is a diagram schematically illustrating an example of the configuration of the half-bridge circuit 3. As shown in Fig. 3, the half-bridge circuit 3 includes a plurality of switching elements 20. Specifically, the half-bridge circuit 3 includes a plurality of sets of legs, each set having a high-voltage side switching element 20a connected to the positive side of the DC bus 12 and a low-voltage side switching element 20b connected to the negative side of the DC bus 12 connected in series. Each leg may have at least one high-frequency capacitor (second capacitor) 21 connected in parallel, for example. Note that Fig. 3 illustrates an example in which two high-frequency capacitors 21 are provided for each leg.

[0013] As shown in Fig. 3, the multiple legs included in the half-bridge circuit 3 are divided into multiple groups. In other words, the half-bridge circuit 3 has multiple leg groups 30. In the half-bridge circuit 3 shown in Fig. 3, each leg group 30 includes two legs. At least one low-frequency capacitor (first capacitor) 22 may be provided for each leg group 30. The low-frequency capacitor 22 is connected between the positive and negative poles of the DC bus 12, and has a larger capacitance than the high-frequency capacitor 21. Examples of the high frequency capacitor 21 include a ceramic capacitor and a multilayer ceramic capacitor. An example of the low frequency capacitor 22 is a film capacitor.

[0014] A short-circuit protection component 25 is provided between each leg group 30 and the positive side of the DC bus 12. An example of the short-circuit protection component 25 is a fuse. The short-circuit protection component 25 cuts off the electrical connection between the leg group 30 and the positive side bus of the DC bus 12 when any element (e.g., switching element 20) constituting the corresponding leg group 30 is short-circuited.

[0015] Figures 4 and 5 show examples of component mounting on the inverter board 40 of this embodiment, where Figure 4 shows an example of component mounting on the first surface (e.g., the front surface) of the inverter board 40, and Figure 5 shows an example of component mounting on the second surface (e.g., the back surface) of the inverter board 40. For example, components that constitute the inverter circuit 1 are mounted on the inverter board 40. Specifically, a plurality of switching elements 20, a plurality of high frequency capacitors 21, a plurality of low frequency capacitors 22, and a plurality of short circuit protection components 25 are mounted on one inverter board 40. Note that the numbers of switching elements 20, high frequency capacitors 21, low frequency capacitors 22, and short circuit protection components 25 mounted on one inverter board 40 are merely examples and are determined appropriately depending on the design.

[0016] As shown in FIG. 4, a first pattern 31 and a plurality of second patterns 32 provided so as to be electrically insulated from the first pattern 31 are provided on the first surface. The first pattern 31 is connected to a DC connector 33, which is a connector for the DC bus 12. On the first pattern 31, a plurality of low frequency capacitors 22 are mounted. At least one switching element 20 and at least one high-frequency capacitor 21 are mounted on each second pattern 32. Specifically, the high-voltage side elements of the leg group 30 are mounted on each second pattern 32. For example, as shown in FIG. 3, when the leg group 30 is made up of two legs, two high-voltage side switching elements 20a and two high-frequency capacitors 21 are mounted on the first pattern 31.

[0017] On the first surface, short-circuit protection components 25 are provided corresponding to each second pattern 32. The short-circuit protection components 25 electrically connect the corresponding second pattern 32 and the first pattern 31. Each short-circuit protection component 25 cuts off the electrical connection between the corresponding second pattern 32 and the first pattern 31 when the high-voltage side switching element 20a or the high-frequency capacitor 21 mounted on the corresponding second pattern 32 is short-circuited.

[0018] The number of high-voltage side switching elements 20a and the number of high-frequency capacitors 21 mounted on the first pattern 31, in other words, the number of these elements constituting the leg group, are merely examples and can be determined appropriately depending on the design. Various embodiments are possible, as shown in FIGS. 6 to 8. For example, as shown in FIG. 6, one high-voltage side switching element 20a and one high-frequency capacitor 21 may be mounted on the first pattern 31. Alternatively, as shown in FIG. 7, two high-voltage side switching elements 20a and three high-frequency capacitors 21 may be mounted on the first pattern 31. Alternatively, as shown in FIG. 8, three high-voltage side switching elements 20a and four high-frequency capacitors 21 may be mounted on the first pattern 31. However, it is preferable that the same number of high-voltage side switching elements 20a and the same number of high-frequency capacitors 21 are mounted on each second pattern 32.

[0019] 5, a third pattern 35 to which the negative terminal of the low-frequency capacitor 22 is connected, and a plurality of fourth patterns 36 are provided on the second surface (rear surface) of the substrate 41. Each fourth pattern 36 is provided at a position facing the first pattern 31 provided on the first surface with the substrate 41 in between. At least one switching element 20 and at least one high-frequency capacitor 21 are mounted in each fourth pattern 36. Specifically, the low-voltage side elements of the leg group 30 are mounted in each fourth pattern 36. For example, as shown in FIG. 3, when a leg group is made up of two legs, two low-voltage side switching elements 20b and two high-frequency capacitors 21 are mounted in the fourth pattern 36.

[0020] The high-voltage side switching element 20a and the low-voltage side switching element 20b that make up one leg are mounted in opposing positions across the substrate 41 as shown in FIG. 9, and are electrically connected, for example, inside the substrate. Furthermore, on the second surface, the number of low-voltage side switching elements 20b mounted on each fourth pattern 36 is the same as the number of high-voltage side switching elements 20a mounted on the second pattern 32. Similarly, on the second surface, the number of high-frequency capacitors 21 mounted on each fourth pattern 36 is the same as the number of high-frequency capacitors 21 mounted on the second pattern 32. On the second surface, a switching drive circuit 38 is provided corresponding to each low-voltage side switching element 20b. The switching drive circuit 38 is a drive circuit for supplying gate charge for turning on and off (driving) the low-voltage side switching elements 20b, and is mounted between the third pattern 35 and the fourth pattern 36. The switching drive circuit 38 is controlled by a control circuit (not shown) provided in the inverter device. Note that various known techniques have been proposed for controlling the on and off of switching elements in the inverter, and these techniques may be adopted as appropriate. Therefore, detailed explanations will be omitted here. Although not shown, a switching drive circuit corresponding to each high-voltage side switching element 20a is also provided on the first surface of the substrate 41. The switching drive circuit for driving the high-voltage side switching element 20a is provided, for example, on the end side of the substrate 41 (for example, area A in FIG. 4).

[0021] Here, as shown in Fig. 4, the short-circuit protection component 25 is provided on the first surface. This is because if the short-circuit protection component 25 were provided on the second surface, the distance D between the low-voltage side switching element 20b and the short-circuit protection component 25 would be long due to the presence of the switching drive circuit 38, as shown in Fig. 10, which would increase the stray capacitance C and inductance L, and would be undesirable from the standpoint of noise effects, etc. For this reason, it is preferable that the short-circuit protection component 25 be connected to a pattern on which a switching element 20 not connected to the switching drive circuit 38 is mounted, i.e., the second pattern 32.

[0022] 4 and 5, various patterns for realizing the inverter circuit 1 shown in FIG. 3 are mounted on the substrate 41. Although the switching elements 20 are shown with their leads facing outward, this is merely a schematic representation of the switching elements 20 being lead components, and in reality, the switching elements 20 are mounted by soldering the leads to patterns on the inverter substrate 40 (see, for example, FIG. 9). Each switching element 20 may be fitted with a heat sink for heat dissipation.

[0023] In such an inverter board 40 (inverter circuit 1), the components for each switching element 20 may be selected with a margin taken into consideration in case some of the switching elements 20 become unusable due to activation of any of the short-circuit protection components 25. Below, the selection of components for the switching elements 20 will be described, assuming that the number of switching elements 20 mounted on each second pattern 32 is the same.

[0024] For example, let Nf be the number of switching elements 20 included in one arm 10 (see FIG. 1), Ns be the number of short-circuit protection components 25 included in one arm 10 (where Ns is a divisor of Nf excluding 1), Id0 be the rated current of the switching elements 20 without taking a margin into account, and Pd0 be the rated power without taking a margin into account. Here, the rated current Id0 and rated power Pd0 refer to the maximum current or maximum power of the switching elements that is allowable in normal control of the inverter circuit 1, and are values ​​that are set appropriately by a designer, for example, taking into account the cooling design of the inverter circuit 1, etc.

[0025] In this case, the rated current Id and rated power Pd of the switching element 20 taking the margin into consideration are expressed by the following equations (1) and (2). In other words, the switching element 20 is an element having a rated current and a rated voltage that satisfy the margin conditions determined according to the number Ns of short-circuit protection components 25.

[0026] Id>{Ns / (Ns-1)}×Id0 (1) Pd>{Ns / (Ns-1)} 2 ×Pd0 (2)

[0027] For example, if one arm 10 is composed of ten switching elements 20 and five short-circuit protection components 25 are provided, the rated current and rated power of the switching elements 20 after taking margins into account are expressed as follows:

[0028] Id>{Ns / (Ns-1)}×Id0=(5 / 4)×Id0=1.25×Id0 Pd>{Ns / (Ns-1)} 2 ×Pd0=1.5625×Pd0

[0029] According to such an inverter board 40, even if some elements fail, the performance can be maintained by the other components, thereby improving the reliability of the inverter board 40 (inverter circuit 1).

[0030] 11, when multiple short-circuit protection components 25 are connected adjacent to one low-frequency capacitor 22, an LC resonance loop may occur due to the stray capacitance C between the parasitic inductance L of the multiple short-circuit protection components 25 and the second pattern 32, as shown in FIG. 12. For this reason, when multiple short-circuit protection components 25 are connected to one low-frequency capacitor 22, the second patterns 32 are arranged on both sides of the low-frequency capacitor 22, and each second pattern 32 is connected by a short-circuit protection component 25, as shown in FIG. 13. This makes it possible to avoid the occurrence of an LC resonance loop caused by the stray capacitance C between the parasitic inductance L of the multiple short-circuit protection components 25 and the second pattern 32.

[0031] As described above, the inverter board 40 and inverter device according to this embodiment include a first pattern 31 provided on a first surface of the board 41 and on which a plurality of low-frequency capacitors 22 are mounted, and a plurality of second patterns 32 provided on the first surface of the board 41 and electrically insulated from the first pattern 31 and on which at least one switching element 20 and at least one high-frequency capacitor 21 are mounted. Each second pattern 32 and the first pattern 31 are electrically connected by a short-circuit protection component 25. When a switching element 20 mounted on a corresponding second pattern 32 is short-circuited, the short-circuit protection component 25 cuts off the electrical connection between the corresponding second pattern 32 and the first pattern 31. Thus, even if a switching element 20 or high-frequency capacitor 21 mounted on any of the second patterns 32 fails, the short-circuit protection component 25 cuts off the electrical connection, thereby maintaining the voltage of the DC bus 12 within a normal range. As a result, the inverter circuit 1 can continue to control the inverter.

[0032] Second Embodiment Hereinafter, a second embodiment of an inverter board and an inverter device according to the present disclosure will be described with reference to the drawings. In the following description, the same components as those in the first embodiment will be denoted by the same reference numerals and will not be described again, and different components will be mainly described.

[0033] 14 is a diagram showing an example of component mounting on the first surface of the inverter board 40a according to this embodiment. As shown in FIG. 14, the inverter board 40a according to this embodiment has a temperature sensor 45 attached to each second pattern 32. Fig. 15 is a block diagram showing a schematic configuration of an inverter device according to this embodiment. As shown in Fig. 15, a temperature measurement value measured by a temperature sensor 45 is transmitted to a control circuit 50. At this time, the temperature measurement value measured by the temperature sensor 45 may be transmitted to the control circuit 50 via a temperature detection circuit 46.

[0034] The control circuit 50 controls the inverter circuit 1 included in the inverter device. The control circuit 50 has, for example, a computer, and is equipped with a CPU (Central Processing Unit: processor), a main memory, a secondary storage, etc. The main memory is composed of writable memory, such as a cache memory or RAM (Random Access Memory), and is used as a work area for reading execution programs of the CPU and writing processing data by the execution programs. The secondary storage is a non-transitory computer-readable storage medium. Examples of secondary storage include magnetic disks such as HDDs (Hard Disk Drives), magneto-optical disks, CD-ROMs, DVD-ROMs, SSDs (Solid State Drives), and semiconductor memories such as flash memories.

[0035] A series of processes for realizing the various functions described below is stored in a secondary storage device or the like in the form of a program, and the various functions are realized by a CPU (processor) reading this program into a main storage device and executing information processing and arithmetic operations. Note that the program may be pre-installed in a secondary storage device, provided in a state stored in a non-transitory computer-readable storage medium, or distributed via wired or wireless communication means. Examples of non-transitory computer-readable storage media include magnetic disks, magneto-optical disks, CD-ROMs, DVD-ROMs, and semiconductor memories.

[0036] The control circuit 50 includes, for example, a determination unit 51 and an output control unit 52. The determination unit 51 determines whether the short-circuit protection component 25 is activated based on the pattern temperature measured by the temperature sensor 45. More specifically, the determination unit 51 may determine whether the short-circuit protection component 25 is activated based not only on the pattern temperature but also on the current command or the operation mode and the pattern temperature. For example, the determination unit 51 has a temperature threshold based on the current command or the operation mode, and when the pattern temperature is equal to or lower than the temperature threshold, the determination unit 51 determines that the short-circuit protection component 25 of the second pattern 32 corresponding to that pattern temperature is activated.

[0037] When the determining unit 51 determines that the short-circuit protection component 25 is activated, the output control unit 52 performs control to reduce the output. The output control unit 52 limits the output current to the load, for example, by reducing the required load. For example, the current command Iout after the limit is set as shown in the following equation (3).

[0038] Iout * <{1-(ns / Ns)}×Iout0 * (3)

[0039] In the above equation (3), Iout *is the current command after limitation for one arm 10 (see FIG. 1), Ns is the number of short-circuit protection circuits provided in one arm 10, ns is the number of short-circuit protection components 25 that have been activated in one arm 10, Iout0 * is a current command for one arm 10 before the short circuit protection device 25 is activated. * Instead, a measurement value of a current flowing through one arm 10 may be used.

[0040] According to this embodiment, a temperature sensor 45 is provided in each second pattern, and the operation of the short circuit protection component 25 is determined based on the temperature measurement value of the temperature sensor 45. This makes it possible to determine the operation of the short circuit protection component 25 without providing a sensor that detects voltage or current. This makes it possible to avoid an increase in inductance that would be caused by providing a voltage detection circuit or a current detection circuit. Furthermore, according to this embodiment, when the operation of the short circuit protection component 25 is detected, the output of the inverter circuit 1 is controlled, thereby making it possible to suppress secondary failures due to current concentration in power elements such as the switching element 20.

[0041] Although the present disclosure has been described above using embodiments, the technical scope of the present disclosure is not limited to the scope described in the above embodiments. Various modifications or improvements can be made to the above embodiments without departing from the gist of the disclosure, and such modifications or improvements are also included in the technical scope of the present disclosure. Furthermore, the above embodiments may be combined as appropriate.

[0042] The inverter board and the inverter device described in each of the above-described embodiments can be understood, for example, as follows.

[0043] The inverter board (40, 40a) according to a first aspect of the present disclosure is an inverter board on which a plurality of switching elements (20), a plurality of first capacitors (22), and a plurality of second capacitors (21) having a smaller capacitance than the first capacitors are mounted, and includes: a first pattern (31) provided on a first surface of the board (41) and on which the plurality of first capacitors are mounted; a plurality of second patterns (32) provided on the first surface of the board and electrically insulated from the first pattern and on which at least one switching element and at least one second capacitor are mounted; and a plurality of short-circuit protection components (25) provided corresponding to each of the second patterns and electrically connecting the corresponding second pattern and the first pattern, wherein the first pattern is connected to a DC bus (12), and each of the short-circuit protection components cuts off the electrical connection between the corresponding second pattern and the first pattern when the switching element or the second capacitor mounted on the corresponding second pattern is short-circuited.

[0044] According to the above aspect, each second pattern and each first pattern are electrically connected by a short-circuit protection component. When a switching element mounted on a corresponding second pattern is short-circuited, the short-circuit protection component cuts off the electrical connection between the corresponding second pattern and the first pattern. Even if a switching element or high-frequency capacitor mounted on any of the second patterns fails, the short-circuit protection component can cut off the electrical connection, thereby maintaining the voltage of the DC bus within a normal range. This allows the inverter circuit to continuously control the inverter, enabling a highly reliable inverter device to be realized.

[0045] The inverter board according to the second aspect of the present disclosure is the inverter board according to the first aspect, which comprises: a third pattern (35) provided on the second surface of the substrate (41) and to which low-voltage side terminals of the plurality of first capacitors are connected; and a fourth pattern (36) provided on the second surface of the substrate and located opposite each of the second patterns across the substrate, wherein a high-voltage side switching element (20a) is mounted on each of the second patterns, and a low-voltage side switching element (20b) is mounted on each of the fourth patterns.

[0046] According to the above aspect, a fourth pattern is provided on the second surface of the substrate at a position facing the second pattern with the substrate in between, and a high-voltage side switching element is mounted on the second pattern provided on the first surface of the substrate, and a low-voltage side switching element is mounted on the fourth pattern provided on the second surface of the substrate.

[0047] The inverter board according to the third aspect of the present disclosure is the inverter board according to the second aspect, which is provided in correspondence with each of the low-voltage side switching elements and includes a switching drive circuit (38) mounted between the third pattern and the fourth pattern.

[0048] According to the above aspect, the switching drive circuit is provided between the third pattern and the fourth pattern provided on the second surface of the substrate. This means that the switching drive circuit is not provided on the first surface of the substrate where the short-circuit protection component is provided. As a result, the distance between the short-circuit protection component and the first pattern can be shortened. This, for example, can avoid an increase in inductance due to the short-circuit protection component being provided near the switching drive circuit, and can also avoid the risk of switching noise and gate resonance.

[0049] According to a fourth aspect of the present disclosure, in the inverter board of any one of the first to third aspects, the same number of switching elements (20) are mounted on each of the second patterns and each of the fourth patterns.

[0050] According to the above aspect, the second pattern and the fourth pattern are provided with the same number of switching elements, so that balanced control can be performed.

[0051] An inverter board according to a fifth aspect of the present disclosure is the inverter board of the fourth aspect, wherein the switching element is a component having characteristics that satisfy margin conditions determined according to the number of short-circuit protection components.

[0052] According to the above aspect, even if some elements fail, the performance can be maintained by the other parts, thereby improving the reliability of the inverter.

[0053] An inverter board according to a sixth aspect of the present disclosure is any one of the first to fifth aspects, in which two of the short-circuit protection components are connected to each of the first capacitors, and the two short-circuit protection components are arranged on both sides of the first capacitor.

[0054] According to the above aspect, it is possible to prevent the occurrence of an LC resonance loop caused by stray capacitance between the parasitic inductance of the plurality of short circuit protection components and the second pattern.

[0055] According to a seventh aspect of the present disclosure, in the inverter board of any one of the first to sixth aspects, a temperature sensor (45) is provided on each of the second patterns.

[0056] According to the above aspect, it is possible to determine whether or not an element mounted on the second pattern is faulty using a temperature sensor, in other words, whether or not a short-circuit protection component is activated. This eliminates the need for a voltage sensor or a current sensor, making it possible to avoid an increase in inductance due to the provision of a voltage sensor or a current sensor. Furthermore, by eliminating the need for a voltage sensor or a current sensor, it is possible to reduce costs and the size of the board.

[0057] An inverter device according to an eighth aspect of the present disclosure includes the inverter board according to any one of the first to seventh aspects, and a control circuit that controls the switching elements.

[0058] An inverter device according to a ninth aspect of the present disclosure includes the inverter board according to the seventh aspect and a control circuit that controls the switching elements, and the control circuit includes a determination unit that determines whether the short-circuit protection component is activated based on the temperature sensor, and an output control unit that performs control to reduce the output when it is determined that the short-circuit protection component is activated.

[0059] According to the above aspect, when it is determined that the short-circuit protection component is activated, the output is reduced, so that it is possible to prevent a secondary failure due to current concentration in the switching element. [Explanation of symbols]

[0060] 1: Inverter circuit 3(3a, 3b): Half-bridge circuit 5: Load 10: Arm 10a: Upper arm 10b: Lower arm 12: DC bus 20: Switching element 20a: High-voltage side switching element 20b: Low-voltage side switching element 21: High frequency capacitor 22: Low frequency capacitor 25: Short circuit protection components 30: Leg Group 31: First pattern 32: Second pattern 33: DC connector 35: Third pattern 36: Fourth pattern 38: Switching drive circuit 40, 40a: Inverter board 41: Substrate 45: Temperature sensor 46: Temperature detection circuit 50: Control circuit 51: Judgment section 52: Output control section

Claims

1. An inverter board on which a plurality of switching elements, a plurality of first capacitors, and a plurality of second capacitors having a capacitance smaller than that of the first capacitors are mounted, a first pattern provided on a first surface of a substrate and having a plurality of the first capacitors mounted thereon; a plurality of second patterns provided on the first surface of the substrate and electrically insulated from the first patterns, and each having at least one switching element and at least one second capacitor mounted thereon; a plurality of short circuit protection components provided corresponding to the second patterns, the short circuit protection components electrically connecting the corresponding second patterns and the first patterns; Equipped with the first pattern is connected to a DC bus; Each of the short circuit protection components is an inverter board that cuts off the electrical connection between the corresponding second pattern and the first pattern when the switching element or the second capacitor mounted on the corresponding second pattern is short-circuited.

2. a third pattern provided on the second surface of the substrate and connected to low-voltage side terminals of the first capacitors; fourth patterns provided on the second surface of the substrate and facing each of the second patterns across the substrate; Equipped with A high-voltage side switching element is mounted on each of the second patterns, The inverter board according to claim 1 , wherein a low-voltage side switching element is mounted on each of the fourth patterns.

3. The inverter board according to claim 2 , further comprising a switching drive circuit provided in correspondence with each of the low-voltage side switching elements and mounted between the third pattern and the fourth pattern.

4. The inverter board according to claim 1 , wherein the same number of switching elements are mounted on each of the second patterns and each of the fourth patterns.

5. 5. The inverter board according to claim 4, wherein the switching elements are components having characteristics that satisfy margin conditions determined according to the number of the short-circuit protection components.

6. Two of the short-circuit protection components are connected to each of the first capacitors; The inverter board according to claim 1 , wherein the two short-circuit protection components are provided on both sides of the first capacitor.

7. The inverter board according to claim 1 , wherein a temperature sensor is provided on each of the second patterns.

8. An inverter board according to any one of claims 1 to 7; a control circuit for controlling the switching element; An inverter device comprising:

9. The inverter board according to claim 7; a control circuit for controlling the switching element; Equipped with the control circuit includes a determination unit that determines whether the short circuit protection component is activated based on the temperature sensor; an output control unit that performs control to reduce the output when it is determined that the short-circuit protection component is activated; An inverter device comprising:

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