Inverter device and method for protecting the same

Abstract

To continue inverter control even when some components are short-circuited.SOLUTION: An inverter device 1 includes a plurality of inverter circuits 10 that convert a voltage supplied from a power supply line L1 and output the converted voltage to an output line L2, and a protection device 20. The protection device 20 has grouping information that groups the plurality of inverter circuits 10 into a plurality of groups GL1 to GLn, and when an abnormality occurs in any of the inverter circuits 10, the protection device 20 cuts off power supply to an inverter circuit 10 in which the abnormality has occurred and to inverter circuits 10 that belong to the same group as the inverter circuit 10.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an inverter device and a method for protecting the same. [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 device and a method for protecting the same 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 device according to one embodiment of the present disclosure includes a plurality of inverter circuits that convert a voltage supplied from a first line and output the converted voltage to a second line, and a protection device that has grouping information that groups the plurality of inverter circuits into a plurality of groups, and that, when an abnormality occurs in any of the inverter circuits, cuts off the supply of power to the inverter circuit in which the abnormality occurred and to the inverter circuits that belong to the same group as the inverter circuit in which the abnormality occurred.

[0007] A method for protecting an inverter device according to one embodiment of the present disclosure is a method for protecting an inverter device having a plurality of inverter circuits that convert a voltage supplied from a first line and output the voltage to a second line, the method having grouping information that groups the plurality of inverter circuits into a plurality of groups, and when an abnormality occurs in any of the inverter circuits, cutting off the supply of power to the inverter circuit in which the abnormality occurred and to the inverter circuits that belong to the same group as the inverter circuit in which the abnormality occurred. [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 schematic configuration diagram showing a configuration example of an inverter device according to a first embodiment of the present disclosure. [Figure 2] 1 is a diagram illustrating a configuration example of a protection device according to a first embodiment of the present disclosure. [Figure 3] 2 is a diagram illustrating an example of a hardware configuration of a protection control unit according to the first embodiment of the present disclosure. FIG. [Figure 4] 3A and 3B are diagrams for explaining the operation of the inverter device according to the first embodiment of the present disclosure. [Figure 5] FIG. 10 is a schematic configuration diagram showing a configuration example of an inverter device according to a second modification of the present disclosure. [Figure 6] FIG. 10 is a schematic configuration diagram showing a configuration example of an inverter device according to a third modification of the present disclosure. [Figure 7] FIG. 10 is a diagram for explaining grouping of inverter devices according to a fourth modification of the present disclosure. [Figure 8] FIG. 10 is a diagram for explaining grouping of inverter devices according to a fourth modification of the present disclosure. [Figure 9] FIG. 6 is a schematic configuration diagram showing a configuration example of an inverter device according to a second embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0010] [First embodiment] A first embodiment of an inverter device and a protection method thereof according to the present disclosure will be described below with reference to the drawings. Fig. 1 is a diagram showing a schematic configuration of an inverter device 1 according to this embodiment. As shown in Fig. 1, the inverter device 1 includes a plurality of inverter circuits 10 that convert a voltage supplied from a power supply line (first line) L1 and output the converted voltage to an output line (second line), and a protection device 20.

[0011] The inverter circuit 10 converts, for example, a DC voltage supplied from a power supply line L1 to which a power supply 7 is connected, into an AC voltage and outputs the AC voltage to an output line L2. A multi-pole three-phase motor 30, which is a load, is connected to the output line L2, and the AC voltage output from the inverter circuit 10 is supplied to the multi-pole three-phase motor 30. Each inverter circuit 10 is provided corresponding to, for example, each winding 5 of the multi-pole three-phase motor 30, and outputs an AC voltage to each winding 5. Note that various elements and circuits, such as a converter device, may be interposed between the power supply 7 and the inverter circuit 10 on the power supply line L1.

[0012] The plurality of inverter circuits 10 are grouped into, for example, a plurality of groups GL1 to GLn, with the minimum unit being three inverter circuits 10a to 10c corresponding to three-phase windings 5a to 5c consisting of U-phase, V-phase, and W-phase. Hereinafter, when it is necessary to distinguish between the inverter circuits, they will be referred to as inverter circuits 10a, 10b, etc., and when it is not necessary to distinguish between them, they will be simply referred to as inverter circuit 10. The same applies to other configurations. The three inverter circuits 10 (10a to 10c) that make up the minimum unit are referred to as inverter unit GU. In this embodiment, a case where the inverter units are grouped for each inverter unit GU, in other words, a case where each inverter unit GU forms one group GL, will be described as an example.

[0013] The inverter circuit 10 includes, for example, a half-bridge circuit or a full-bridge circuit. In one inverter circuit 10, each switch constituting the full-bridge circuit or half-bridge circuit is configured with a plurality of switching elements (for example, FETs, IGBTs, etc.) connected in parallel. Furthermore, a plurality of capacitors may be further connected in parallel to the switching elements.

[0014] One inverter circuit 10 may be realized by, for example, one inverter board. In this case, each inverter circuit 10 can be read as each inverter board. Furthermore, each inverter circuit (inverter board) may be mounted with a protection component that, in the event of an abnormality (short-circuit fault), cuts off the connection between the short-circuited element and the power line (power supply pattern on the board) L1. In this way, by having the protection component in the inverter circuit and the protection device 20 described below, it is possible to further improve safety.

[0015] The protection device 20 has grouping information that groups multiple inverter circuits 10 into multiple groups GL, and when an abnormality occurs in any of the inverter circuits 10, it cuts off the power supply to the inverter circuit 10 in which the abnormality occurred and to the inverter circuits 10 that belong to the same group GL as the inverter circuit 10. For example, the protection device 20 is provided on the power supply line L1 and includes protection circuits 2 provided corresponding to the inverter circuits 10, respectively. The protection circuits 2 are, for example, switches, contactors, etc. Each protection circuit 2 is controlled, for example, by a protection control unit 3 (see FIG. 2).

[0016] The protection control unit 3 is configured to be able to communicate bidirectionally with, for example, the inverter control unit 8 provided in each inverter circuit 10. The inverter control unit 8 transmits, for example, sensor signals measured by various sensors provided in the inverter circuit 10 to the protection control unit 3. The protection control unit 3 detects an abnormality in the inverter circuit 10 based on these sensor signals. Here, the various sensors include at least one of a current sensor, a voltage sensor, and a temperature sensor. The sensor signals include, for example, at least one of a current measurement value, a voltage measurement value, and a temperature measurement value. The protection control unit 3 determines whether an abnormality has occurred in the inverter circuit 10 based on the sensor signals acquired from each inverter circuit 10. For example, the protection control unit 3 may have a preset threshold and detect an abnormality by comparing the sensor signal with the threshold. An example of an abnormality is a short-circuit fault.

[0017] Fig. 3 is a diagram showing an example of the hardware configuration of the protection control unit 3. As shown in Fig. 3, the protection control unit 3 includes, for example, a CPU (Central Processing Unit: processor) 11, a main memory 12, a secondary storage (memory) 13, a communication interface 15, and the like.

[0018] The CPU 11 controls the protection circuit 2 using, for example, an embedded operating system (OS) stored in a secondary storage device 13 connected via a bus, and executes various processes by executing various programs stored in the secondary storage device 13. One or more CPUs 11 may be provided, and they may perform processes in cooperation with each other. Note that an OS does not necessarily have to be implemented. In other words, it is not necessary to use an OS to execute a program.

[0019] The main memory device 12 is composed of writable memory such as cache memory and RAM (Random Access Memory), and is used as a working area for reading out programs executed by the CPU 11 and writing data processed by the programs. The secondary storage device 13 is a non-transitory computer-readable storage medium. The secondary storage device 13 is, for example, a semiconductor memory. An example of the secondary storage device 13 is a flash memory. The secondary storage device 13 stores programs for implementing various processes and various data required for implementing the various processes. A plurality of secondary storage devices 13 may be provided, and the above-mentioned programs and data may be divided and stored in each secondary storage device 13.

[0020] The communication interface 15 functions as an interface for connecting to a network within the device to communicate with other devices and send and receive information. For example, the communication interface 15 communicates with other devices via wired or wireless communication. Examples of wired communication include serial communication such as RS-232C and RS-485, CAN (Controller Area Network), and Ethernet. Examples of wireless communication include communication via lines such as Bluetooth (registered trademark), Wi-Fi, mobile communication systems (3G, 4G, 5G, 6G, LTE, etc.), and wireless LAN.

[0021] A series of processes for realizing the functions of the protection control unit 3 is stored in the form of a program in the secondary storage device 13, for example, and the CPU (processor) 11 reads this program into the main storage device 12 and executes information processing and arithmetic processing to realize various functions. Note that the program may be pre-installed in the secondary storage device 13, or may be distributed via wired or wireless communication means, for example.

[0022] For example, the protection control unit 3 may be realized by a PLC (Programmable Logic Controller) or the like. The inverter control unit 8 included in the inverter circuit 10 also has a similar configuration.

[0023] The protection control unit 3 has grouping information that groups the inverter circuits 10 into groups GL. The grouping information is stored in the secondary storage device 13 that the protection control unit 3 includes, for example.

[0024] The protection control unit 3 determines whether or not an abnormality (e.g., short-circuit fault) has occurred in the inverter circuit 10, for example, based on a sensor signal from each inverter control unit 8. If it determines that an abnormality has occurred in the inverter circuit 10, it acquires information about the inverter circuits 10 that belong to the same group GL as the inverter circuit 10 from the grouping information, and outputs an operation command to the protection circuits 2 corresponding to the inverter circuit 10 in which the abnormality has occurred and the inverter circuits 10 that belong to the same group GL as the inverter circuit 10. As a result, the protection circuits 2 are activated, and the power supply to each inverter circuit 10 is cut off.

[0025] Furthermore, the protection control unit 3 may transmit an abnormality occurrence signal to all inverter control units 8 that belong to the group GL of the inverter circuit 10 in which the abnormality has occurred. The inverter control unit 8 that has received the abnormality occurrence signal stops control of the inverter circuit 10. For example, the control of the inverter circuit is stopped by turning off all switching elements (e.g., FETs, IGBTs, etc.) of the bridge circuit provided in the inverter circuit 10.

[0026] The function of detecting an abnormality may be provided in each inverter control unit 8 instead of the protection control unit 3. In this case, when an abnormality is detected in each inverter control unit 8, an abnormality occurrence signal indicating this is transmitted from the inverter control unit 8 to the protection control unit 3.

[0027] As described above, according to this embodiment, the protection device 20 has grouping information that groups a plurality of inverter circuits 10 into a plurality of groups GL, and, when an abnormality occurs in any of the inverter circuits 10, cuts off the power supply to the inverter circuit 10 in which the abnormality occurred and to the inverter circuits 10 that belong to the same group as that inverter circuit 10. As a result, when an abnormality such as a short circuit occurs in the inverter circuit 10, the inverter circuit 10 in which the abnormality occurred and the inverter circuits 10 that belong to the same group as that inverter circuit 10 can be quickly disconnected from the power supply line L1. As a result, the power supply line L1 can be maintained at a normal voltage, and inverter control by the remaining inverter circuits 10 can be continued.

[0028] Furthermore, the three inverter circuits 10 corresponding to the U phase, V phase, and W phase, which constitute the inverter unit GU, which is the smallest unit constituting the group GL, are inverter circuits 10 that may become uncontrollable if an abnormality occurs in any of the inverter circuits 10. Therefore, by making such an inverter unit GU the smallest unit of the group GL, it is possible to improve the safety of the inverter device 1.

[0029] 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 following modifications can be adopted as alternatives or additions, and each modification can be applied in appropriate combination.

[0030] [Variation 1] In the first embodiment described above, the protection control unit 3 controls the protection circuit 2, but this is not limiting. For example, the inverter control unit 8 of each inverter circuit 10 may control the corresponding protection circuit 2. In this case, the inverter control units 8 are configured to be able to communicate with each other. As shown in FIG. 4, for example, when an abnormality occurs in its own inverter circuit 10, the operation of the inverter circuit 10 is stopped and the corresponding protection circuit 2 is activated. Specifically, a switch is opened. This allows the inverter circuit 10 in which the abnormality has occurred to be quickly disconnected from the power supply line L1.

[0031] Furthermore, the inverter control unit 8 of the inverter circuit 10 in which the abnormality has occurred transmits an abnormality notification signal to the inverter control units 8 of the other inverter circuits 10 that belong to the same group GL. In this case, each inverter control unit 8 only needs to have information about the other inverter control units 8 that belong to the same group.

[0032] An inverter control unit 8 that receives an abnormality notification signal from another inverter control unit 8 stops the operation of its own inverter circuit 10 and activates the corresponding protection circuit 2. This makes it possible to disconnect from the power supply line L1 the inverter circuits 10 that belong to the same group as the inverter circuit 10 in which the abnormality occurred. For example, as shown in FIG. 4, if an abnormality occurs in the inverter circuit 10a of the group GL1, the inverter circuits 10a to 10c of the same group GL1 are disconnected from the power supply line L1. This makes it possible to continue inverter control by the other groups GL2 to GLn. Furthermore, the inverter device 1 according to the first modification does not require the protection control unit 3, and therefore the inverter device 1 can be made smaller and lighter.

[0033] [Variation 2] In the first embodiment described above, the protection circuit 2 is configured as a switch, but this is not limiting. For example, as shown in FIG. 5, the protection circuit 2 may be configured as a fuse. Configuring the protection circuit 2 as a fuse makes it possible to easily detect an abnormality by detecting a blown fuse. Note that if the protection circuit 2 is a fuse, an overcurrent does not flow through an inverter circuit 10 in which no abnormality has occurred, and the inverter circuit 10, which is a fuse, cannot be disconnected from the power supply line L1 by the protection circuit 2, which is a fuse. Therefore, in the second modification, the inverter circuits 10 in the same group GL (e.g., the inverter circuits 10b and 10c in the group GL1) as the inverter circuit 10 in which an abnormality has occurred (e.g., the inverter circuit 10a in the group GL1) are disconnected from the power supply line L1 by control in the inverter circuit 10. For example, the connection to the power supply line L1 is disconnected by turning off all switching elements (e.g., FETs, IGBTs, etc.) of the bridge circuit provided in the inverter circuit 10. In this case, notification of the occurrence of an abnormality to inverter control units 8 belonging to the same group may be made from the inverter control unit 8 of the inverter circuit 10 in which the abnormality has occurred, or may be made from the protection control unit 3. In particular, by making the notification from the inverter control unit 8, the protection control unit 3 can be made unnecessary.

[0034] [Variation 3] In the first embodiment described above, the protection circuit 2 is connected to each inverter circuit 10, but this is not limiting. For example, as shown in FIG. 6, a protection circuit 2 may be provided for each group GL. In this case, the protection circuit 2 may be a switch as shown in FIG. 6, or may be configured as a fuse as in Modification 2. In particular, when a protection circuit 2 is provided for each group GL, by using a fuse as the protection circuit 2, if a short circuit occurs in an inverter circuit 10, an overcurrent will flow through the inverter circuit 10 in which the short circuit has occurred, causing the fuse of the corresponding protection circuit 2 to blow. This eliminates the need for communication of an abnormality notification signal within the group and simplifies protection control.

[0035] [Variation 4] In the first embodiment described above, three inverter circuits 10 (10a-10c) corresponding to three-phase windings 5a-5c consisting of U, V, and W phases are registered as one group GL. However, the grouping method is not limited to this. For example, as shown in FIGS. 7 and 8, six inverter circuits 10 corresponding to at least two three-phase windings 5a-5c provided at opposing positions on the stator 31 of a multi-pole three-phase motor 30 may be grouped. For example, if the multi-pole three-phase motor 30 is a two-pole three-phase motor, as shown in FIG. 8, the inverter device will have four inverter units GU1-GU4. In this case, the six inverter circuits 10 (10a-10c) corresponding to the three-phase windings 5a-5c consisting of U, V, and W phases provided at opposing positions on the stator 31 will be grouped. As a result, a group GL1 including inverter units GU1 and GU4 and a group GL2 including inverter units GU2 and GU3 will be registered as group information.

[0036] For example, if an abnormality occurs in the inverter circuit 10 (e.g., inverter circuit 10a) of inverter unit G1, an abnormality notification signal is sent to the inverter circuits 10 in the same group GL1 as the inverter circuit 10 in which the abnormality occurred (e.g., inverter circuits 10b, 10c of inverter unit GU1 and inverter circuits 10a to 10c of inverter unit G4), thereby stopping the operation of each inverter circuit 10 and cutting off the connection to the power supply line L1 due to activation of protection circuit 2.

[0037] According to the fourth modification, grouping is performed taking into consideration the arrangement of the coils in the stator 31, so that it is possible to prevent the occurrence of axial vibration due to imbalance in the arrangement, and it is possible to continue stable motor operation.

[0038] Second Embodiment Next, a second embodiment of the present disclosure will be described. In the first embodiment described above, a case was described in which a multi-pole, three-phase motor 30 was used as a load and power was supplied to the multi-pole, three-phase motor, but in this embodiment, an inverter device 1a will be described in which a multi-pole, three-phase motor is used as a generator. Hereinafter, the same components as in the first embodiment will be assigned the same reference numerals and explanations will be omitted, and differences will be mainly described.

[0039] Fig. 9 is a diagram showing an example of the configuration of an inverter device 1a according to this embodiment. As shown in Fig. 9, the inverter device 1 includes a plurality of inverter circuits 10 that convert AC voltage supplied from a power supply line (first line) L1 connected to a multi-pole three-phase motor 30 into DC voltage and output it to an output line (second line) L2. In this embodiment, in which the multi-pole three-phase motor 30 is used as a generator, the input and output of the inverter circuits 10 are reversed from those in the first embodiment.

[0040] Each power supply line L1 connecting the inverter circuit 10 and the multi-pole three-phase motor 30 is provided with a protection circuit 2. That is, in the protection device 20a according to this embodiment, the power supply line (first line) L1 and the output line (second line) L2 are each provided with a protection circuit 2. As described in the first embodiment and Modification 4 above, the inverter circuits 10 are grouped with the inverter unit GU being the smallest unit.

[0041] In such an inverter device 1a, if an abnormality is detected in the inverter circuit 10, the operation of the inverter circuit 10 in which the abnormality occurred and other inverter circuits 10 belonging to the same group as that inverter circuit 10 is stopped, and the protection circuits 2 corresponding to these inverter circuits 10 are activated, cutting off the connection to the power supply line L1 and the output line L2.

[0042] As described above, according to this embodiment, when a multi-pole three-phase motor 30 is used as a generator, the protection circuits 2 are provided on both the power supply line L1 and the output line L2, and if an abnormality occurs in any of the inverter circuits 10, a protection device 20a is provided that cuts off the power supply to the inverter circuits 10 that belong to the same group as the inverter circuit 10 where the abnormality occurred. As a result, if an abnormality such as a short circuit occurs in an inverter circuit 10, the inverter circuit 10 where the abnormality occurred and the inverter circuits 10 that belong to the same group as that inverter circuit 10 can be quickly disconnected from the power supply line L1 and the output line L2. As a result, the power supply line L1 and the output line L2 can be maintained at normal voltage, and inverter control by the remaining inverter circuits 10 can be continued.

[0043] Furthermore, the three inverter circuits 10 corresponding to the U phase, V phase, and W phase, which constitute the inverter unit GU, which is the smallest unit constituting the group GL, are inverter circuits 10 that may become uncontrollable if an abnormality occurs in any of the inverter circuits 10. Therefore, by making such an inverter unit GU the smallest unit of the group GL, it is possible to improve the safety of the inverter device 1.

[0044] Also, in the second embodiment, the above-described modified examples 2 to 4 can be applied in appropriate combination. For example, the operation of the protection circuit 2 may be performed by the protection control unit 3 as in the first embodiment, or by the inverter control unit 8 provided in each inverter circuit 10 as in Modification 1. Furthermore, Modification 2 can be adopted to use fuses instead of switches in the protection circuit 2. Furthermore, Modification 3 can be adopted to provide the protection circuits 2 provided on the output line L2 in the protection device 20a for each group. Here, the protection circuit 2 provided on the power supply line L1 needs to be provided for each inverter circuit 10. Furthermore, Modification 4 can be adopted to group the multiple inverter circuits 10, with six inverter circuits 10 corresponding to opposing windings in the coil arrangement of the stator 31 being treated as one group GL.

[0045] Furthermore, the first and second embodiments may be combined, which makes it possible to use the multi-pole three-phase motor 30 both as a load and as a generator.

[0046] The inverter board and the inverter device described in each of the above-described embodiments can be understood, for example, as follows.

[0047] An inverter device (1, 1a) according to a first aspect of the present disclosure includes a plurality of inverter circuits (10) that convert a voltage supplied from a first line (L1) and output the converted voltage to a second line (L2), and a protection device (20, 20a) that has grouping information that groups the plurality of inverter circuits into a plurality of groups (GL) and, when an abnormality occurs in any of the inverter circuits, cuts off the supply of power to the inverter circuit in which the abnormality occurred and to the inverter circuits that belong to the same group as the inverter circuit in which the abnormality occurred.

[0048] According to the above aspect, when an abnormality such as a short circuit occurs in an inverter circuit, the inverter circuit in question and the inverter circuits in the same group as that inverter circuit can be quickly disconnected from the power supply line, thereby maintaining the power supply line at a normal voltage and enabling the remaining inverter circuits to continue to control the inverters.

[0049] In the inverter device according to a second aspect of the present disclosure, in the above-described first aspect, a multi-pole three-phase motor (30) is connected to the second line, and each of the inverter circuits is provided corresponding to each winding (5) of the multi-pole three-phase motor and outputs an AC voltage to each of the windings, and the plurality of inverter circuits are grouped into a plurality of groups, with three of the inverter circuits (10a to 10c) corresponding to a three-phase winding being the smallest unit.

[0050] According to the above aspect, the minimum grouping unit is three inverter circuits corresponding to a three-phase winding consisting of a U-phase winding, a V-phase winding, and a W-phase winding. If an abnormality occurs in any of these three inverter circuits, these three inverter circuits may be affected by the abnormality and become uncontrollable. Therefore, by using these three inverter circuits as the minimum grouping unit, it is possible to improve the safety of the inverter device.

[0051] In the inverter device (1, 1a) according to a third aspect of the present disclosure, in the second aspect, each group includes six inverter circuits corresponding to at least two of the three-phase windings (5a to 5c) arranged in opposing positions in the stator (31) of the multi-pole three-phase motor (30).

[0052] According to the above aspect, grouping is performed taking into consideration the arrangement of the coils in the stator, so that it is possible to prevent the occurrence of axial vibration due to imbalance in the arrangement, and it is possible to continue stable motor operation.

[0053] An inverter device (1, 1a) according to a fourth aspect of the present disclosure is any one of the first to third aspects, wherein the protection devices (20, 20a) are provided on the first line (L1) and include protection circuits (2) provided corresponding to the inverter circuits (10), respectively, and control units (3, 8) capable of controlling the protection circuits.

[0054] According to the above aspect, a protection circuit corresponding to each inverter circuit is provided on the first line, and this protection circuit is controlled by the control unit to cut off power supply not only to the inverter circuit in which an abnormality has occurred, but also to inverter circuits belonging to the same group as that inverter circuit.

[0055] An inverter device according to a fifth aspect of the present disclosure is the inverter device of any of the first to third aspects, wherein the protection device (20) is provided in the first line (L1) and includes protection circuits (2) provided corresponding to each of the groups (GL).

[0056] According to the above aspect, since a protection circuit is provided for each group, it is possible to easily cut off the power supply to multiple inverter circuits belonging to the same group by activating the protection circuit, thereby achieving miniaturization and cost reduction of the inverter device.

[0057] An inverter device (1a) according to a sixth aspect of the present disclosure is any one of the first to fifth aspects, wherein the protection device (20a) is provided on each of the first line (L1) and the second line (L2), and includes a plurality of protection circuits 2 provided corresponding to each of the inverter circuits (10) or each of the groups (GL), and a control unit (3, 8) that controls the plurality of protection circuits 2.

[0058] According to the above aspect, for example, it is possible to deal with both the case where the motor is treated as a load and the case where the motor is treated as a generator.

[0059] A seventh aspect of the present disclosure provides a method for protecting an inverter device (1, 1a) including a plurality of inverter circuits (10) that convert a voltage supplied from a first line (L1) and output the converted voltage to a second line (L2), the method including grouping information that groups the plurality of inverter circuits (10) into a plurality of groups (GL), and when an abnormality occurs in any of the inverter circuits, cutting off the supply of power to the inverter circuit in which the abnormality occurred and to the inverter circuits that belong to the same group as the inverter circuit in which the abnormality occurred. [Explanation of symbols]

[0060] 1: Inverter device 1a: Inverter device 2 :Protection circuit 3: Protection control unit (control unit) 5: Winding 5a: Three-phase winding 5b: Three-phase winding 5c: Three-phase winding 8: Inverter control unit (control unit) 10: Inverter circuit 10a: Inverter circuit 10b: Inverter circuit 10c: Inverter circuit 11: CPU 12: Main memory 13:Secondary storage device 20 :Protective device 20a: Protective device 30: Multi-pole three-phase motor 31: Stator G1: Inverter unit G4: Inverter unit GL: Group GL1: Group GL2: Group GU: Inverter unit GU1: Inverter unit GU2: Inverter unit GU3: Inverter unit GU4: Inverter unit L1: Power line (first line) L2: Output line (second line)

Claims

1. a plurality of inverter circuits that convert a voltage supplied from a first line and output the converted voltage to a second line; a protection device that has grouping information that groups the plurality of inverter circuits into a plurality of groups, and that, when an abnormality occurs in any of the inverter circuits, cuts off the supply of power to the inverter circuit in which the abnormality occurs and to the inverter circuits that belong to the same group as the inverter circuit in which the abnormality occurs; An inverter device comprising:

2. a multi-pole three-phase motor is connected to the second line; Each of the inverter circuits is provided corresponding to each winding of the multi-pole three-phase motor, and outputs an AC voltage to each of the windings; 2. The inverter device according to claim 1, wherein the plurality of inverter circuits are grouped into a plurality of groups, with three of the inverter circuits corresponding to three-phase windings being the minimum unit.

3. 3. The inverter device according to claim 2, wherein each of the groups includes six of the inverter circuits corresponding to at least two of the three-phase windings provided at positions facing each other in the stator of the multi-pole three-phase motor.

4. The protection device comprises: protection circuits provided on the first line and corresponding to each of the inverter circuits; a control unit capable of controlling the protection circuit; The inverter device according to claim 1 , comprising:

5. The inverter device according to claim 1 , wherein the protection device is provided on the first line and includes a protection circuit provided corresponding to each of the groups.

6. The protection device comprises: a plurality of protection circuits provided on the first line and the second line, respectively, corresponding to each of the inverter circuits or each of the groups; a control unit that controls the plurality of protection circuits; The inverter device according to claim 1 , comprising:

7. A method for protecting an inverter device including a plurality of inverter circuits that convert a voltage supplied from a first line and output the converted voltage to a second line, comprising: A protection method for an inverter device that has grouping information that groups a plurality of the inverter circuits into a plurality of groups, and that, when an abnormality occurs in any of the inverter circuits, cuts off the supply of power to the inverter circuit in which the abnormality occurred and to the inverter circuits that belong to the same group as the inverter circuit in which the abnormality occurred.

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