Abnormality detection circuit, motor drive device, motor system, and vehicle

Abstract

This abnormality detection circuit is configured so as to detect abnormality of a first half bridge including a first switching element and a second switching element. The abnormality detection circuit includes: a series circuit of a first switch and a first resistor provided between a first node which is a connection node for the first switching element and the second switching element and a second node configured so as to have a first constant voltage applied thereto; and a first comparator configured so as to compare a first reference voltage and a voltage corresponding to the voltage of the first node.

Description

Abnormality detection circuit, motor drive device, motor system, and vehicle

[0001] The invention disclosed in this specification relates to an abnormality detection circuit, and a motor drive device, a motor system, and a vehicle that have the abnormality detection circuit.

[0002] 2. Description of the Related Art Conventionally, there exists an abnormality detection circuit that drives a motor and detects an abnormality based on the rotation state of the motor (see, for example, Patent Document 1).

[0003] JP 2015-226450 A

[0004] Conventional abnormality detection circuits cannot detect abnormalities unless the motor is driven.

[0005] The abnormality detection circuit disclosed in this specification is configured to detect an abnormality in a first half bridge including a first switching element and a second switching element, and includes: a series circuit of a first resistor and a first switch provided between a first node which is a connection node of the first switching element and the second switching element and a second node configured to receive a first constant voltage; and a first comparator configured to compare a voltage corresponding to the voltage of the first node with a first reference voltage.

[0006] The motor drive device disclosed in this specification has an abnormality detection circuit with the above configuration.

[0007] The motor system disclosed in this specification includes a motor and a motor drive device configured to drive the motor.

[0008] The vehicle disclosed in this specification has a motor system having the above-described configuration.

[0009] According to the invention disclosed in this specification, an abnormality can be detected without driving the motor.

[0010] FIG. 1 is a diagram showing a schematic configuration of a motor system according to a first embodiment. FIG. 2 is a diagram showing the details of abnormality detection. FIG. 3 is a diagram showing a schematic configuration of a motor system according to a second embodiment. FIG. 4 is a diagram showing a schematic configuration of a motor system according to a third embodiment. FIG. 5 is a diagram showing a schematic configuration of a motor system according to a fourth embodiment. FIG. 6 is a diagram showing the details of abnormality detection. FIG. 7 is a diagram showing a schematic configuration of a motor system according to a fifth embodiment. FIG. 8 is a diagram showing a schematic configuration of a motor system according to a sixth embodiment. FIG. 9 is a diagram showing the motor system mounted on a vehicle.

[0011] In this specification, a MOS transistor refers to a field effect transistor whose gate structure is made up of at least three layers: a layer made of a conductor or a semiconductor such as polysilicon with a low resistance value, an insulating layer, and a P-type, N-type, or intrinsic semiconductor layer. In other words, the gate structure of a MOS transistor is not limited to a three-layer structure of a metal, an oxide, and a semiconductor.

[0012] In this specification, a constant voltage means a voltage that is constant under ideal conditions, but in reality it is a voltage that may fluctuate slightly due to temperature changes and the like.

[0013] In this specification, the reference voltage means a voltage that is constant under ideal conditions, but in reality it is a voltage that may fluctuate slightly due to temperature changes and the like.

[0014] 1 is a diagram showing a schematic configuration of a motor system 11 according to Embodiment 1. The motor system 11 has a motor drive device 21, which is a so-called motor driver IC (integrated circuit), switching elements M1A, M2A, M1B, and M2B, and a motor 31.

[0015] The motor drive device 21 drives the motor 31 via switching elements M1A, M2A, M1B, and M2B. In this embodiment, the switching elements M1A, M2A, M1B, and M2B are externally connected to the motor drive device 21. Unlike this embodiment, the switching elements M1A, M2A, M1B, and M2B may be built into the motor drive device 21. Also, in this embodiment, the switching elements M1A, M2A, M1B, and M2B are N-channel MOS transistors. Unlike this embodiment, the switching elements M1A, M2A, M1B, and M2B may be switching elements other than N-channel MOS transistors. Examples of switching elements other than N-channel MOS transistors include P-channel MOS transistors, IGBTs (Insulated Gate Bipolar Transistors), and transistors using compound semiconductors such as SiC.

[0016] Motor drive device 21 includes pre-drivers 1A and 1B, a reference voltage source 2A, a comparator 3A, a logic unit 4, resistors R1A, R2A, and R3A, and a switch SW1A. Motor drive device 21 also includes a bootstrap circuit (not shown) for switching elements M1A and M1B, a rotation speed detection unit (not shown) that detects the rotation speed of a rotor provided in motor 31, and the like.

[0017] A power supply voltage VBB, which is a constant voltage, is applied to the drains of the switching elements M1A and M1B, the pre-drivers 1A and 1B, and the logic unit 4.

[0018] The motor 31 is provided between the node N1A and the node N1B. More specifically, the stator coil (not shown) of the motor 31 is provided between the node N1A and the node N1B. The stator coil (not shown) of the motor 31 is an example of a load provided between the node N1A and the node N1B. The resistance value of the stator coil (not shown) of the motor 31 is sufficiently smaller than the resistance values ​​of the resistors R1A, R2A, and R3A. The node N1A is a connection node between the source of the switching element M1A and the drain of the switching element M2A. The node N1B is a connection node between the source of the switching element M1B and the drain of the switching element M2B.

[0019] A ground voltage, which is a constant voltage lower than the power supply voltage VBB, is applied to the sources of the switching elements M1A and M1B. The ground voltage, which is a constant voltage lower than the power supply voltage VBB, is also supplied to the pre-drivers 1A and 1B.

[0020] The logic unit 4 performs on / off control of the switching elements M1A, M2A, M1B, and M2B. The logic unit 4 supplies a switch signal S1A for performing on / off control of the switching elements M1A and M2A to the pre-driver 1A. The logic unit 4 supplies a switch signal S1B for performing on / off control of the switching elements M1B and M2B to the pre-driver 1B.

[0021] The pre-driver 1A generates gate signals G1A and G2A according to the switch signal S1A, supplies the gate signal G1A to the gate of the switching element M1A, and supplies the gate signal G2A to the gate of the switching element M2A.

[0022] The pre-driver 1B generates gate signals G1B and G2B according to the switch signal S1B, supplies the gate signal G1B to the gate of the switching element M1B, and supplies the gate signal G2B to the gate of the switching element M2B.

[0023] An abnormality detection circuit constituted by a reference voltage source 2A, a comparator 3A, a logic unit 4, resistors R1A, R2A, and R3A, a switch SW1A, and the logic unit 4 detects an abnormality in the half bridge including the switching elements M1A and M2A.

[0024] A first end of resistor R1A and a first end of resistor R2A are connected to node N1A. A second end of resistor R1A is connected to node N2A via switch SW1A. A constant ground voltage is applied to node N2A. In other words, a series circuit of resistor R1A and switch SW1A is provided between node N1A and node N2A. When switch SW1A is on, resistor R1A functions as a pull-down resistor.

[0025] A second terminal of the resistor R2A is connected to a first terminal of the resistor R3A and a non-inverting input terminal of the comparator 3A. A ground voltage is applied to the second terminal of the resistor R3A.

[0026] The reference voltage source 2A supplies a reference voltage VREF1A to the inverting input terminal of the comparator 3A. The comparator 3A supplies a signal OUT1A to the logic unit 4, which is the result of comparing a voltage corresponding to the voltage of the node N1A (a voltage obtained by dividing the voltage of the node N1A by resistors R2A and R3A) with the reference voltage VREF1A.

[0027] A current is supplied from the pre-driver 1A to the series circuit of resistors R2A and R3A. The product of this current and the resistance of resistor R3A is set to be greater than the reference voltage VREF1A. In other words, the reference voltage VREF1A is smaller than the voltage drop across resistor R3A when switch SW1A is off. As a result, in the initial state, i.e., when switching elements M1A and M2A are off and switch SW1A is off, signal OUT1A goes high.

[0028] The resistance value of the resistor R3A is set to be larger than the resistance value of the resistor R1A, so that when the switch SW1A is turned on, the voltage supplied to the non-inverting input terminal of the comparator 3A is reliably at a low level.

[0029] The logic unit 4 also controls the on / off of the switch SW1A. The logic unit 4 detects an abnormality in the half bridge including the switching elements M1A and M2A by combining the on / off states of the switching elements M1A, M2A, and switch SW1A with the level of the signal OUT1A. Specifically, the logic unit 4 detects an abnormality as shown in Figure 2. Note that (1) in Figure 2 indicates that the abnormality has occurred in the switching element M1A, and (5) in Figure 2 indicates that the abnormality has occurred in the switching element M2A.

[0030] The abnormality detection circuit provided in the motor drive device 21 can detect an abnormality without driving the motor 31.

[0031] Furthermore, the abnormality detection circuit provided in the motor drive device 21 can prevent current from constantly flowing through the resistor R1A by having the logic unit 4 turn off the switch SW1A unless an abnormality is detected, thereby suppressing unnecessary current consumption in the resistor R1A.

[0032] Furthermore, the abnormality detection circuit provided in the motor drive device 21 is configured so that only one comparator is required for the half bridge including the switching elements M1A and M2A, and therefore an increase in the circuit area can be suppressed.

[0033] 3 is a diagram showing a schematic configuration of a motor system 12 according to a second embodiment. The motor system 12 includes a motor drive device 22, switching elements M1A, M2A, M1B, and M2B, and a motor 31. Note that in this embodiment, descriptions of parts that are the same as those in the first embodiment will be omitted.

[0034] Motor driving device 22 differs from motor driving device 21 in that power supply voltage VBB is applied to node N2A instead of ground voltage.

[0035] In this embodiment, the reference voltage VREF1A is greater than the voltage drop across the resistor R3A when the switch SW1A is off, so that in the initial state, i.e., when the switching elements M1A and M2A are off and the switch SW1A is off, the signal OUT1A goes low.

[0036] In this embodiment, when the switch SW1A is on, the resistor R1A functions as a pull-up resistor.

[0037] The abnormality detection circuit provided in the motor drive device 22 has the same effect as the abnormality detection circuit provided in the motor drive device 21 .

[0038] 4 is a diagram showing a schematic configuration of a motor system 13 according to a third embodiment. The motor system 13 includes a motor drive device 23, switching elements M1A, M2A, M1B, and M2B, and a motor 31. Note that in this embodiment, descriptions of parts that are the same as those in the first embodiment will be omitted.

[0039] Motor drive device 23 differs from motor drive device 21 in that it has resistor R1A' and switch SW1A', and logic unit 4 also controls the on / off of switch SW1A'.

[0040] A first end of the resistor R1A' is connected to the node N1A. A second end of the resistor R1A' is connected to the node N2A' via the switch SW1A. That is, the series circuit of the resistor R1A' and the switch SW1A' is provided between the node N1A and the node N2A'. The power supply voltage VBB is applied to the node N2A'. When the switch SW1A' is on, the resistor R1A' functions as a pull-up resistor.

[0041] When abnormality detection is performed with switch SW1A' fixed to off, reference voltage VREF1A is set to be smaller than the voltage drop across resistor R3A when switch SW1A is off. Conversely, when abnormality detection is performed with switch SW1A fixed to off, reference voltage VREF1A is set to be larger than the voltage drop across resistor R3A when switch SW1A is off.

[0042] The abnormality detection circuit provided in the motor drive device 23 has the same effect as the abnormality detection circuits provided in the motor drive devices 21 and 22 .

[0043] 5 is a diagram showing a schematic configuration of a motor system 14 according to a fourth embodiment. The motor system 14 includes a motor drive device 24, switching elements M1A, M2A, M1B, and M2B, and a motor 31. Note that in this embodiment, descriptions of parts that are the same as those in the first embodiment will be omitted.

[0044] Motor driving device 24 differs from motor driving device 21 in that motor driving device 24 includes resistors R1B, R2B, and R3B, a switch SW1B, a reference voltage source 2B, and a comparator 3B.

[0045] An abnormality detection circuit composed of reference voltage sources 2A and 2B, comparators 3A and 3B, a logic unit 4, resistors R1A, R2A, R3A, R1B, R2B, and R3B, switches SW1A and SW1B, and the logic unit 4 detects an abnormality in the half bridge including switching elements M1A and M2A and an abnormality in the half bridge including switching elements M1B and M2B.

[0046] A first end of resistor R1B and a first end of resistor R2B are connected to node N1A. A second end of resistor R1B is connected to node N2B via switch SW1B. A constant ground voltage is applied to node N2B. In other words, a series circuit of resistor R1B and switch SW1B is provided between node N1B and node N2B. When switch SW1B is on, resistor R1B functions as a pull-down resistor.

[0047] A second terminal of the resistor R2B is connected to a first terminal of the resistor R3B and a non-inverting input terminal of the comparator 3B. A ground voltage is applied to a second terminal of the resistor R3B.

[0048] The reference voltage source 2B supplies a reference voltage VREF1B to the inverting input terminal of the comparator 3B. The comparator 3B supplies a signal OUT1B to the logic unit 4, which is the result of comparing a voltage corresponding to the voltage of the node N1B (a voltage obtained by dividing the voltage of the node N1B by resistors R2B and R3B) with the reference voltage VREF1B.

[0049] A current is supplied from the pre-driver 1B to the series circuit of resistors R2B and R3B. The product of this current and the resistance of resistor R3B is set to be greater than the reference voltage VREF1B. In other words, the reference voltage VREF1B is smaller than the voltage drop across resistor R3B when switch SW1B is off. As a result, in the initial state, i.e., when switching elements M1A, M2A, M1B, and M2B are off and switches SW1A and SW1B are off, signal OUT1B goes high.

[0050] The resistance value of the resistor R3B is set to be larger than the resistance value of the resistor R1B, so that when the switch SW1B is turned on, the voltage supplied to the non-inverting input terminal of the comparator 3B is reliably at a low level.

[0051] The logic unit 4 also controls the on / off of the switch SW1B. The logic unit 4 detects an abnormality in the half bridge including the switching elements M1A and M2A and an abnormality in the half bridge including the switching elements M1B and M2B based on a combination of the on / off states of the switching elements M1A, M2A, M1B, M2B, switch SW1A, and switch SW1B and the levels of the signals OUT1A and OUT1B. Specifically, the logic unit 4 detects an abnormality as shown in FIG. 6.

[0052] The first mode in FIG. 6 is a mode in which the switch SW1A is turned off, the switch SW1B is turned off, the gate signal G1A is a signal (low-level signal) for turning off the switching element M1A, the gate signal G2A is a signal (low-level signal) for turning off the switching element M2A, the gate signal G1B is a signal (low-level signal) for turning off the switching element M1B, and the gate signal G2B is a signal (low-level signal) for turning off the switching element M2B.

[0053] The second mode in FIG. 6 is a mode in which switch SW1A is turned on, switch SW1B is turned off, gate signal G1A is a signal (low-level signal) for turning off switching element M1A, gate signal G2A is a signal (low-level signal) for turning off switching element M2A, gate signal G1B is a signal (low-level signal) for turning off switching element M1B, and gate signal G2B is a signal (low-level signal) for turning off switching element M2B.

[0054] The third mode in FIG. 6 is a mode in which switch SW1A is turned off, switch SW1B is turned on, gate signal G1A is a signal (low-level signal) for turning off switching element M1A, gate signal G2A is a signal (low-level signal) for turning off switching element M2A, gate signal G1B is a signal (low-level signal) for turning off switching element M1B, and gate signal G2B is a signal (low-level signal) for turning off switching element M2B.

[0055] The fourth mode in FIG. 6 is a mode in which switch SW1A is turned on, switch SW1B is turned off, gate signal G1A is a signal (high-level signal) for turning on switching element M1A, gate signal G2A is a signal (low-level signal) for turning off switching element M2A, gate signal G1B is a signal (low-level signal) for turning off switching element M1B, and gate signal G2B is a signal (low-level signal) for turning off switching element M2B.

[0056] The fifth mode in FIG. 6 is a mode in which switch SW1A is turned off, switch SW1B is turned off, gate signal G1A is a signal (low-level signal) for turning off switching element M1A, gate signal G2A is a signal (high-level signal) for turning on switching element M2A, gate signal G1B is a signal (low-level signal) for turning off switching element M1B, and gate signal G2B is a signal (low-level signal) for turning off switching element M2B.

[0057] The sixth mode in FIG. 6 is a mode in which switch SW1A is turned off, switch SW1B is turned on, gate signal G1A is a signal (low-level signal) for turning off switching element M1A, gate signal G2A is a signal (low-level signal) for turning off switching element M2A, gate signal G1B is a signal (high-level signal) for turning on switching element M1B, and gate signal G2B is a signal (low-level signal) for turning off switching element M2B.

[0058] The seventh mode in FIG. 6 is a mode in which switch SW1A is turned off, switch SW1B is turned off, gate signal G1A is a signal (low-level signal) for turning off switching element M1A, gate signal G2A is a signal (low-level signal) for turning off switching element M2A, gate signal G1B is a signal (low-level signal) for turning off switching element M1B, and gate signal G2B is a signal (high-level signal) for turning on switching element M2B.

[0059] (1) in Fig. 6 indicates that the abnormality has occurred in switching element M1A. (2) in Fig. 6 indicates that the abnormality has occurred in switching element M1B. (3) in Fig. 6 indicates that the abnormality has occurred in the path from node N1A to motor 31. (4) in Fig. 6 indicates that the abnormality has occurred in the path from node N1B to motor 31. (5) in Fig. 6 indicates that the abnormality has occurred in switching element M2A. (6) in Fig. 6 indicates that the abnormality has occurred in switching element M2B.

[0060] In the first mode, if both signals OUT1A and OUT1B are at a high level, the logic unit 4 determines that no abnormality has occurred.

[0061] In the first mode, if the signals OUT1A and OUT1B are both at a low level, the logic unit 4 determines that an abnormality has occurred in that at least one of the switching elements M2A and M2B is short-circuited to ground.

[0062] In the second mode, if both signals OUT1A and OUT1B are at a low level, the logic unit 4 determines that no abnormality has occurred.

[0063] In the second mode, if the signals OUT1A and OUT1B are both high, the logic unit 4 determines that an abnormality has occurred in that at least one of the switching elements M1A and M1B is shorted to the power supply. Note that by limiting the current flowing through the motor 31 using the resistance value of the resistor R1A, a short in at least one of the switching elements M1A and M1B can be detected without rotating the rotor of the motor 31.

[0064] In the second mode, if the signal OUT1A is at a low level and the signal OUT1B is at a high level, the logic unit 4 determines that an abnormality has occurred in that at least one of the paths from the node N1A to the motor 31 and the path from the node N1B to the motor 31 is open.

[0065] In the third mode, if both signals OUT1A and OUT1B are at a low level, the logic unit 4 determines that no abnormality has occurred.

[0066] In the third mode, if the signals OUT1A and OUT1B are both high, the logic unit 4 determines that an abnormality has occurred in that at least one of the switching elements M1A and M1B is shorted to the power supply. Note that by limiting the current flowing through the motor 31 using the resistance value of the resistor R1A, a short in at least one of the switching elements M1A and M1B can be detected without rotating the rotor of the motor 31.

[0067] In the third mode, if the signal OUT1A is at a high level and the signal OUT1B is at a low level, the logic unit 4 determines that an abnormality has occurred in that at least one of the paths from the node N1A to the motor 31 and the path from the node N1B to the motor 31 is open.

[0068] In the fourth mode, if both signals OUT1A and OUT1B are at a high level, the logic unit 4 determines that no abnormality has occurred. In the fourth mode, only the switching element M1A of the four switching elements is turned on, so the rotor of the motor 31 does not rotate.

[0069] In the fourth mode, if both the signals OUT1A and OUT1B are at a low level, the logic unit 4 determines that an abnormality has occurred in that the switching element M1A is open.

[0070] In the fifth mode, if the signals OUT1A and OUT1B are both at a low level, the logic unit 4 determines that no abnormality has occurred. In the fifth mode, only the switching element M2A of the four switching elements is turned on, so the rotor of the motor 31 does not rotate.

[0071] In the fifth mode, if both the signals OUT1A and OUT1B are at a high level, the logic unit 4 determines that an abnormality has occurred in that the switching element M2A is open.

[0072] In the sixth mode, if both signals OUT1A and OUT1B are at a high level, the logic unit 4 determines that no abnormality has occurred. In the sixth mode, only the switching element M1B of the four switching elements is turned on, so the rotor of the motor 31 does not rotate.

[0073] In the sixth mode, if both the signals OUT1A and OUT1B are at a low level, the logic unit 4 determines that an abnormality has occurred in that the switching element M1B is open.

[0074] In the seventh mode, if both signals OUT1A and OUT1B are at a low level, the logic unit 4 determines that no abnormality has occurred. In the seventh mode, only the switching element M2B of the four switching elements is turned on, so the rotor of the motor 31 does not rotate.

[0075] In the seventh mode, if both the signals OUT1A and OUT1B are at a high level, the logic unit 4 determines that an abnormality has occurred in that the switching element M2B is open.

[0076] Furthermore, if the path from node N1A to resistor R1A is open, signal OUT1A will not go low even if signal OUT1B goes low in the seventh mode. Therefore, in the seventh mode, the logic unit 4 can also determine whether the path from node N1A to resistor R1A is open.

[0077] Furthermore, if the path from node N1B to resistor R1B is open, signal OUT1B will not go low even if signal OUT1A goes low in the seventh mode. Therefore, in the seventh mode, the logic unit 4 can also determine whether the path from node N1B to resistor R1B is open.

[0078] Furthermore, if the gate signal transmission line is open, the switching element corresponding to the open gate signal transmission line will not be turned on, and therefore the logic unit 4 can also determine whether the gate signal transmission line is open by monitoring changes in the signals OUT1A and OUT1B of the fourth to seventh modes.

[0079] The abnormality detection circuit provided in the motor drive device 24 can detect an abnormality without driving the motor 31.

[0080] In addition, the abnormality detection circuit provided in the motor drive device 24 can suppress current consumption by stopping the current supply from the pre-driver 1A to the resistors R2A and R3A and stopping the current supply from the pre-driver 1B to the resistors R2B and R3B while the motor 31 is being driven.

[0081] Furthermore, the abnormality detection circuit provided in the motor drive device 24 is configured so that only one comparator is required for the half bridge including the switching elements M1A and M2A, and only one comparator is required for the half bridge including the switching elements M1B and M2B, thereby preventing an increase in the circuit area.

[0082] 7 is a diagram showing a schematic configuration of a motor system 15 according to a fifth embodiment. The motor system 15 includes a motor drive device 25, switching elements M1A, M2A, M1B, and M2B, and a motor 31. Note that in this embodiment, descriptions of parts that are the same as those in the fourth embodiment will be omitted.

[0083] Motor drive device 25 differs from motor drive device 24 in that it does not have switch SW1B.

[0084] In the fourth embodiment, an abnormality that can be detected in the second mode can also be detected in the third mode (see FIG. 6).

[0085] In this embodiment, the second mode cannot be executed, but as described above, the abnormalities that can be detected in the second mode can also be detected in the third mode. Therefore, the abnormality detection circuit provided in motor drive device 25 has the same effect as each abnormality detection circuit provided in motor drive device 24.

[0086] 8 is a diagram showing a schematic configuration of a motor system 16 according to a sixth embodiment. The motor system 16 has a motor drive device 26, switching elements M1A, M2A, M1B, and M2B, and a motor 31. Note that in this embodiment, descriptions of parts that are the same as those in the fourth embodiment will be omitted.

[0087] Motor drive device 26 differs from motor drive device 24 in that it does not have resistors R2A and R2B.

[0088] In the fourth embodiment, the voltage corresponding to the voltage at node N1A supplied to the non-inverting input terminal of comparator 3A is a voltage obtained by dividing the voltage at node N1A using resistors R2A and R3A, and the voltage corresponding to the voltage at node N1B supplied to the non-inverting input terminal of comparator 3B is a voltage obtained by dividing the voltage at node N1B using resistors R2B and R3B.

[0089] In contrast, in the fifth embodiment, the voltage corresponding to the voltage of node N1A supplied to the non-inverting input terminal of comparator 3A is the voltage of node N1A itself, and the voltage corresponding to the voltage of node N1B supplied to the non-inverting input terminal of comparator 3B is the voltage of node N1B itself.

[0090] Therefore, for example, when it is not necessary to lower the withstand voltage of the comparators 3A and 3B, the configuration of this embodiment may be adopted instead of the configuration of embodiment 4. By adopting the configuration of this embodiment, the circuit configuration of the abnormality detection circuit can be simplified compared to when the configuration of embodiment 4 is adopted.

[0091] <Application Example> Each of the above-described motor systems 11 to 16 is mounted on a vehicle CC such as an automobile, for example, as shown in FIG.

[0092] The motor systems 11 to 16 mounted on the vehicle CC are used, for example, as sunroof motor systems, sliding door motor systems, EPS (Electric Power Steering) motor systems, oil pump motor systems, water pump motor systems, etc.

[0093] The installation of each of the motor systems 11 to 16 is not limited to a vehicle, but may also be industrial equipment, consumer equipment, or the like.

[0094] <Others> Various modifications can be made to the embodiments of the present disclosure as appropriate within the scope of the technical ideas set forth in the claims. The various embodiments described so far may be combined as appropriate within a consistent scope. The above-described embodiments are merely examples of embodiments of the present disclosure, and the meanings of the terms in the present disclosure and each constituent element are not limited to those described in the above embodiments.

[0095] For example, if the motor is a three- or more-phase motor, the motor drive circuit may drive the polyphase motor via three or more half bridges, and the abnormality detection circuit provided in the motor drive circuit may have the same number of comparators as the number of half bridges. In this case, desired two half bridges are selected in order from the three or more half bridges, and the switching elements and switches corresponding to the half bridges not selected are turned off, thereby enabling abnormalities to be detected in a manner similar to that of the fourth embodiment.

[0096] <Supplementary Note> Supplementary notes are provided for the present disclosure, the specific configuration examples of which have been shown in the above-described embodiments.

[0097] The abnormality detection circuit of the present disclosure is an abnormality detection circuit configured to detect an abnormality in a first half bridge including a first switching element (M1A) and a second switching element (M2A), and has a configuration (first configuration) including: a series circuit of a first resistor (R1A) and a first switch (SW1A) provided between a first node (N1A) that is a connection node of the first switching element and the second switching element and a second node (N2A) configured to receive a first constant voltage; and a first comparator (3A) configured to compare a voltage corresponding to the voltage of the first node with a first reference voltage.

[0098] In the abnormality detection circuit of the first configuration described above, the abnormality detection circuit may be configured to detect an abnormality in the first half bridge and an abnormality in a second half bridge including a third switching element (M1B) and a fourth switching element (M2B), and may further include a second resistor (R1B) provided between a third node (N1B) which is a connection node between the third switching element and the fourth switching element and a fourth node (N2B) configured to apply a second constant voltage, and a second comparator (3B) configured to compare a voltage corresponding to the voltage of the third node with a second reference voltage (second configuration).

[0099] The abnormality detection circuit of the second configuration may further include a second switch (SW1B) connected in series to the second resistor (third configuration).

[0100] In the abnormality detection circuit of the second or third configuration, the resistance value of the load provided between the first half bridge and the second half bridge may be smaller than the resistance value of the first resistor and the resistance value of the second resistor (fourth configuration).

[0101] The abnormality detection circuit of any of the first to fourth configurations may further include a third resistor (R3A) configured so that a voltage corresponding to the voltage of the first node is applied to a first terminal and a ground voltage is applied to a second terminal, and the resistance value of the third resistor may be greater than the resistance value of the first resistor (fifth configuration).

[0102] In the anomaly detection circuit of the fifth configuration described above, the first resistor may be a pull-down resistor when the first switch is on, and the first reference voltage may be smaller than the voltage drop across the third resistor when the first switch is off (sixth configuration).

[0103] In the abnormality detection circuit of the fifth configuration described above, the first resistor may be a pull-up resistor when the first switch is on, and the first reference voltage may be larger than the voltage drop across the third resistor when the first switching element and the second switching element are normal and the first switch is off (seventh configuration).

[0104] The motor drive devices (21 to 26) of the present disclosure have a configuration (eighth configuration) that includes an abnormality detection circuit having any of the first to seventh configurations.

[0105] The motor system (11 to 26) of the present disclosure has a configuration (ninth configuration) that includes a motor (31) and a motor drive device of the eighth configuration configured to drive the motor.

[0106] The vehicle (CC) of the present disclosure has a configuration (tenth configuration) that includes the motor system of the ninth configuration described above.

[0107] 1A, 1B Pre-driver 2A, 2B Reference voltage source 3A, 3B Comparator 4 Logic unit 11 to 16 Motor system 21 to 26 Motor drive device 31 Motor CC Vehicle R1A, R1A', R2A, R3A, R1B, R2B, R3B Resistors SW1A, SW1A', SW1B Switches M1A, M1B, M2A, M2B Switching elements N1A, N2A, N2A', N1B, N2B Nodes

Claims

1. An abnormality detection circuit configured to detect an abnormality in a first half bridge including a first switching element and a second switching element, a series circuit including a first resistor and a first switch provided between a first node which is a connection node between the first switching element and the second switching element and a second node configured to receive a first constant voltage; a first comparator configured to compare a voltage corresponding to the voltage of the first node with a first reference voltage; An abnormality detection circuit having

2. An abnormality detection circuit configured to detect an abnormality in the first half bridge and an abnormality in a second half bridge including a third switching element and a fourth switching element, a second resistor provided between a third node, which is a connection node between the third switching element and the fourth switching element, and a fourth node configured to receive a second constant voltage; a second comparator configured to compare a voltage at the third node with a second reference voltage; The anomaly detection circuit of claim 1 , further comprising:

3. 3. The abnormality detection circuit according to claim 2, further comprising a second switch connected in series with the second resistor.

4. 3. The abnormality detection circuit according to claim 2, wherein a resistance value of a load provided between the first half bridge and the second half bridge is smaller than a resistance value of the first resistor and a resistance value of the second resistor.

5. a third resistor configured to apply a voltage corresponding to the voltage of the first node to a first terminal and a ground voltage to a second terminal; 2. The abnormality detection circuit according to claim 1, wherein a resistance value of the third resistor is greater than a resistance value of the first resistor.

6. the first resistor becomes a pull-down resistor when the first switch is on; 6. The abnormality detection circuit according to claim 5, wherein the first reference voltage is smaller than a voltage drop across the third resistor when the first switching element and the second switching element are normal and the first switch is off.

7. the first resistor becomes a pull-up resistor when the first switch is on; 6. The abnormality detection circuit according to claim 5, wherein the first reference voltage is greater than a voltage drop across the third resistor when the first switching element and the second switching element are normal and the first switch is off.

8. A motor drive device comprising the abnormality detection circuit according to any one of claims 1 to 7.

9. A motor; A motor drive device according to claim 8 configured to drive the motor; A motor system comprising:

10. A vehicle comprising the motor system according to claim 9.