Motor control device

Abstract

A motor control device (40) for controlling the driving of a motor (10) having a motor winding (11) is provided with a drive circuit (41) and a control unit (50). The drive circuit (41) has switching elements (411-413) for switching the ON / OFF of energization to each phase of the motor winding (11). The control unit (50) has a drive control unit (55) for controlling the on / off operation of the switching elements (411-413), and an abnormality determination unit (52) for determining an abnormality in a current path to the motor winding (11). The abnormality determination unit (52) determines a faulty phase on the basis of a voltage detection value when switching elements (411-413) of all phases are turned off, and determines the abnormality of the faulty phase on the basis of at least one of a current detection value when switching elements of the determined faulty phase are turned on and a rotational position detection value when switching elements (411-413) of one or more phases of a normal phase are turned on. And determining the always power-on fault of the fault phase.

Description

[0001] Related Application

[0002] This application is made based on Japanese Patent Application No. 2022-150083 filed on September 21, 2022, and the contents described therein are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to a motor control device. Background Art

[0004] Conventionally, there are known motor control devices for controlling the driving of a motor. For example, in Patent Document 1, a wire breakage detection circuit is provided in each current supply path of a winding of each phase to detect a wire breakage.

[0005] Prior Art Literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2004-129450 Summary of the invention

[0008] In Patent Document 1, when the switching element is turned off, the voltage becomes high when a disconnection fault or a ground short-circuit fault occurs, and the two cannot be distinguished. The present disclosure aims to provide a motor control device capable of appropriately identifying a fault state.

[0009] The motor control device disclosed in the present invention controls the drive of a motor having a motor winding of more than three phases, and comprises a drive circuit and a control unit. The drive circuit comprises a switch element for switching on and off the power supply to each phase of the motor winding. The control unit comprises a drive control unit for controlling the on and off action of the switch element and an abnormality determination unit for determining an abnormality in a power supply path to the motor winding.

[0010] The control unit can obtain the detection value of the voltage detection unit that detects the phase voltage of the motor winding, namely the voltage detection value, the detection value of the current detection unit that detects the current supplied to the motor winding, namely the current detection value, and the detection value of the rotation detection unit that detects the rotation position of the motor, namely the rotation position detection value.

[0011] The abnormality determination unit determines the faulty phase based on the voltage detection value when the switch elements of all phases are set to be disconnected. The abnormality determination unit determines the always-on fault of the faulty phase based on at least one of the current detection value when the switch element of the determined faulty phase is set to be turned on and the rotation position detection value when the switch element of one or more phases of the normal phase is set to be turned on. In this way, the fault state can be appropriately determined. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The above-mentioned purpose and other purposes, features and advantages of the present disclosure will be more clearly understood through the following detailed description with reference to the accompanying drawings.

[0013] Figure 1 is a perspective view showing a shift-by-wire system according to a first embodiment;

[0014] Figure 2 is a schematic structural diagram showing a shift-by-wire system according to a first embodiment;

[0015] Figure 3 is a circuit diagram illustrating an ECU according to a first embodiment;

[0016] Figure 4 is a schematic diagram showing a motor according to a first embodiment;

[0017] Figure 5 is a schematic diagram showing an encoder according to a first embodiment;

[0018] Figure 6 is a circuit diagram illustrating a U-phase disconnection;

[0019] Figure 7 is a circuit diagram illustrating a short circuit to ground;

[0020] Figure 8 is a circuit diagram illustrating an incomplete ground short circuit;

[0021] Fig. 9 is a flowchart illustrating a fault phase determination process of the first embodiment;

[0022] Fig.10 is an explanatory diagram for explaining the current when the switching element of the faulty phase is turned on during an incomplete ground short circuit;

[0023] Fig.11 is an explanatory diagram showing a current when a switching element of a faulty phase is turned on during a ground fault;

[0024] Fig.12 This is an explanatory diagram for explaining the magnetic attraction when power is supplied to the V phase;

[0025] Fig.13 This is an explanatory diagram for explaining the behavior of the rotor when the energization state is switched when the U phase is disconnected in the first embodiment;

[0026] Fig.14 This is an explanatory diagram for explaining the behavior of the rotor when the energization state is switched when the U phase is disconnected in the first embodiment;

[0027] Fig.15 This is an explanatory diagram for explaining the behavior of the rotor when the energization state is switched when the U phase is always energized in the first embodiment;

[0028] Fig.16 This is an explanatory diagram for explaining the behavior of the rotor when the energization state is switched when the U phase is always energized in the first embodiment;

[0029] Fig.17 is an explanatory diagram for explaining the rotation angle difference corresponding to the switching of the energization state in the first embodiment;

[0030] Fig.18 is a flowchart illustrating a power-on process involved in fault determination according to the first embodiment;

[0031] Fig.19 is a flowchart illustrating a power-on process involved in fault determination according to the first embodiment;

[0032] Fig. 20 is a flowchart illustrating the failure state determination process of the first embodiment;

[0033] Fig.21 is a timing chart for explaining the behavior of the rotor in the energization process of the first embodiment;

[0034] Fig. 22 This is a subroutine for explaining the maximum value update process in the power-on state ST13 of the first embodiment;

[0035] Fig.23 This is a subroutine for explaining the minimum value update process in the power-on state ST14 of the first embodiment;

[0036] Fig.24 is a timing chart illustrating the shift switching process of the first embodiment;

[0037] Fig.25 A correspondence table in which the energized phase numbers and the energized phases are associated with each other in the first embodiment;

[0038] Fig.26 A timing chart for explaining the processing when a stall abnormality occurs when the motor is driven by two normal phases in the first embodiment;

[0039] Fig. 27 is a flowchart illustrating a power-on process involved in fault determination according to the second embodiment;

[0040] Fig.28 is a flowchart illustrating the failure state determination process of the second embodiment;

[0041] Fig.29 is a timing chart illustrating the shift switching process of the second embodiment;

[0042] Fig.30This is an explanatory diagram for explaining the behavior of the rotor when the energization state is switched when the U phase is disconnected in the third embodiment;

[0043] Fig.31 This is an explanatory diagram for explaining the behavior of the rotor when the energization state is switched when the U phase is disconnected in the third embodiment;

[0044] Fig.32 This is an explanatory diagram for explaining the behavior of the rotor when the energization state is switched in the event of a U-phase always-energized failure in the third embodiment;

[0045] Fig.33 This is an explanatory diagram for explaining the behavior of the rotor when the energization state is switched in the event of a U-phase always-energized failure in the third embodiment;

[0046] Fig.34 is an explanatory diagram for explaining the rotation angle difference corresponding to the switching of the energization state in the third embodiment;

[0047] Fig.35 is a flowchart illustrating a power-on process related to fault determination according to the third embodiment;

[0048] Fig.36 is a flowchart illustrating a power-on process related to fault determination according to the third embodiment;

[0049] Fig.37 This is an explanatory diagram for explaining the behavior of the rotor when the energization state is switched when the U phase is disconnected in the fourth embodiment;

[0050] Fig.38 This is an explanatory diagram for explaining the behavior of the rotor when the energization state is switched when the U phase is disconnected in the fourth embodiment;

[0051] Fig.39 It is an explanatory diagram for explaining the behavior of the rotor when the energization state is switched in the event of a U-phase always-energized failure in the fourth embodiment;

[0052] Fig.40 It is an explanatory diagram for explaining the behavior of the rotor when the energization state is switched in the event of a U-phase always-energized failure in the fourth embodiment;

[0053] Fig.41 is a flowchart illustrating a fault state determination process according to a fourth embodiment;

[0054] Fig.42 is a timing chart for explaining the behavior of the rotor when the energization state is switched when the U phase is disconnected in the fifth embodiment;

[0055] Fig.43 is a timing chart for explaining the behavior of the rotor when the energization state is switched when the U phase is disconnected in the fifth embodiment;

[0056] Fig.44 is a timing chart for explaining the behavior of the rotor when the energization state is switched when the U phase is always energized in the fifth embodiment;

[0057] Fig.45 is a flowchart illustrating a power-on process involved in fault determination according to the fifth embodiment;

[0058] Fig.46 is a flowchart illustrating a fault state determination process according to a fifth embodiment;

[0059] Fig.47 This is a subroutine for explaining the maximum and minimum value update process in the power-on state ST22 of the fifth embodiment;

[0060] Fig.48 This specification describes the subroutine of the maximum and minimum value updating process in the power-on state ST23 of the fifth embodiment. DETAILED DESCRIPTION

[0061] (First Embodiment)

[0062] Hereinafter, the motor control device of the present disclosure will be described based on the drawings. In the following, in a plurality of embodiments, substantially the same configurations are denoted by the same reference numerals and description thereof will be omitted.

[0063] The first embodiment is as follows Figure 1 to Figure 26 As shown. Figure 1 and Figure 2 As shown, the shift-by-wire system 1 includes a motor 10 , a detent mechanism 20 , a parking lock mechanism 30 , and an ECU 40 as a motor control device.

[0064] The motor 10 is rotated by being supplied with electric power from a battery 90 mounted on a vehicle (not shown), and functions as a driving source for the locking mechanism 20. The motor 10 is, for example, a switched reluctance motor.

[0065] like Figure 3 and Figure 4 As shown, the motor 10 includes a stator 101, a rotor 103, a motor winding 11, etc. The motor winding 11 includes a U-phase coil 111, a V-phase coil 112, and a W-phase coil 113, which are wound around the salient pole 102 of the stator 101. The coils 111 to 113 are connected by a connection unit 115. The connection unit 115 is connected to the battery 90 via the motor relay 91 and the fuse 92.

[0066] The rotor 103 has salient poles and is rotatably disposed radially inside the stator 101. The rotor 103 is driven to rotate by switching the energized phases of the coils 111 to 113. In the present embodiment, the number of salient poles of the stator 101 is 12, and the number of salient poles of the rotor 103 is 8. Hereinafter, the salient poles of the rotor 103 are referred to as convex portions 104, and the space between the convex portions is referred to as concave portions 105.

[0067] The encoder 13 is a magnetic rotary encoder for detecting the rotation position of the rotor 103. The encoder 13 includes Hall elements 131 and 132 for magnetic detection and a magnet 135 that rotates integrally with the rotor 103. The Hall elements 131 and 132 output pulse signals at every predetermined angle in synchronization with the rotation of the rotor 103. In this embodiment, when the Hall elements 131 and 132 are opposite to the N pole, a Lo signal is output, and when the Hall elements 131 and 132 are opposite to the S pole, a Hi signal is output.

[0068] like Figure 5 As shown, the magnet 135 is formed into a circular ring shape and is arranged coaxially with the rotor 103. The magnet 135 is magnetized alternately with N poles and S poles at equal intervals in the circumferential direction. The magnetization pitch of this embodiment is 7.5°. This magnetization pitch is the same as the rotation angle of the rotor 103 each time the motor 10 is excited. That is, if the energized phase is switched six times in a 1-2 phase excitation method of switching the energized phase such as U phase → UV phase → V phase → VW phase → W phase → WU phase for one cycle, the rotor 103 rotates at a mechanical angle of 7.5×6=45°.

[0069] The Hall elements 131 and 132 are arranged on the same circumference in such a way that the phase difference becomes an electrical angle of 90°. In the present embodiment, the electrical angle of 90° corresponds to the mechanical angle of 3.75°, and the Hall elements 131 and 132 are arranged at an interval of 48.75°. In the present embodiment, the signal of the Hall element 131 is set to the A phase, and the signal of the Hall element 132 is set to the B phase. In addition, the encoder 13 is a 2-phase encoder, but it can also be a 3-phase encoder, and it can also output a Z-phase signal as a reference signal in addition to the detection signal.

[0070] Return to Figure 1 The reducer 14 is provided between the motor shaft of the motor 10 and the output shaft 15, and reduces the rotation speed of the motor 10 and outputs it to the output shaft 15. Thus, the rotation of the motor 10 is transmitted to the locking mechanism 20. The output shaft sensor 16 is, for example, a potentiometer, and is used to detect the rotation position of the output shaft 15 (refer to Figure 2 ).

[0071] The lock mechanism 20 includes a lock plate 21 , a lock spring 25 , and a lock roller 26 , and transmits the rotational drive force output from the speed reducer 14 to the parking lock mechanism 30 .

[0072] The lock plate 21 is fixed to the output shaft 15 and driven by the motor 10. The lock plate 21 has two valleys 211 and 212 and a peak 215 sandwiching the valleys 211 and 212 on the lock spring 25 side.

[0073] The lock spring 25 is a plate-shaped member capable of elastic deformation, and a lock roller 26 is provided at the front end thereof. The lock spring 25 urges the lock roller 26 toward the rotation center side of the lock plate 21 .

[0074] When a rotational force greater than a predetermined value is applied to the lock plate 21, the lock spring 25 is elastically deformed, and the lock roller 26 moves between the valleys 211 and 212. The lock roller 26 is inserted into one of the valleys 211 and 212, thereby limiting the swing of the lock plate 21, and the state of the parking lock mechanism 30 and the shift position of the automatic transmission 5 are determined.

[0075] The parking lock mechanism 30 includes a parking rod 31, a cone 32, a parking brake lever 33, a shaft 34, and a parking gear 35. The parking rod 31 is formed in a substantially L-shaped shape, and one end 311 is fixed to the locking plate 21. The cone 32 is provided on the other end 312 of the parking rod 31. The cone 32 is formed in a manner that the diameter decreases toward the other end 312. When the locking plate 21 rotates in a direction in which the locking roller 26 is embedded in the valley 211 corresponding to the P gear, the cone 32 moves in the direction of the arrow P.

[0076] The parking brake lever 33 is in contact with the conical surface of the cone 32 and is provided so as to be able to swing around the shaft 34. A convex portion 331 capable of meshing with the parking gear 35 is provided on the parking gear 35 side of the parking brake lever 33. When the cone 32 moves in the direction of the arrow P by the rotation of the lock plate 21, the parking brake lever 33 is pressed up and the convex portion 331 meshes with the parking gear 35. On the other hand, when the cone 32 moves in the direction of the arrow notP, the meshing of the convex portion 331 with the parking gear 35 is released.

[0077] The parking gear 35 is connected to a drive shaft (not shown) and is configured to be meshed with a convex portion 331 of the parking brake lever 33. When the parking gear 35 is meshed with the convex portion 331, the rotation of the drive shaft is restricted. When the shift position is a gear other than P, i.e., notP, the parking gear 35 is not locked by the parking brake lever 33, and the rotation of the drive shaft is not hindered by the parking lock mechanism 30. In addition, when the shift position is P, the parking gear 35 is locked by the parking brake lever 33, and the rotation of the drive shaft is restricted.

[0078] like Figure 2 and Figure 3As shown, the ECU 40 includes a drive circuit 41, a current detection unit 45, a voltage detection circuit 46, a control unit 50, etc. The drive circuit 41 has three switching elements 411, 412, and 413. The switching elements 411 to 413 are respectively arranged corresponding to the coils 111 to 113 to switch the energization of the corresponding phases. In the present embodiment, the switching elements 411 to 413 are arranged between the coils 111 to 113 and the ground. The switching elements 411 to 413 of the present embodiment are MOSFETs, but may also be IGBTs, etc. In the figures, etc., the switching elements 411 to 413 are appropriately recorded as "MOS".

[0079] The current detection unit 45 is provided in the collective wiring connecting the source of the switching elements 411 to 413 to the ground, and detects the sum of the currents flowing in the coils 111 to 113. Hereinafter, the current detected by the current detection unit 45 is referred to as the motor current Im. The current detection unit 45 can be provided at any position capable of detecting the current of the coils 111 to 113, and can also be provided for each phase.

[0080] The voltage detection circuit 46 is connected between the coils 111 to 113 and the switching elements 411 to 413 to detect the terminal voltage of each phase. The relay driver 48 controls the on / off operation of the motor relay 91 .

[0081] The control unit 50 is mainly composed of a microcomputer, etc., and has a CPU, ROM, RAM, I / O, and a bus connecting these structures, all of which are not shown in the figure. Each process in the control unit 50 can be a software process implemented by the CPU executing a program pre-stored in a physical memory device such as a ROM (i.e., a readable non-temporary tangible storage medium), or a hardware process implemented by a dedicated electronic circuit.

[0082] The control unit 50 controls the switching of the shift position by controlling the driving of the motor 10 based on a shift signal corresponding to the shift position requested by the driver, a signal from a brake switch, an accelerator opening, a vehicle speed, and the like, thereby controlling the switching of the shift position and the like.

[0083] The control unit 50 includes a signal acquisition unit 51, an abnormality determination unit 52, and a drive control unit 55 as functional modules. The signal acquisition unit 51 acquires detection signals from the encoder 13, the output shaft sensor 16, the current detection unit 45, and the voltage detection circuit 46. The abnormality determination unit 52 determines the abnormality of the shift-by-wire system 1. The details of the abnormality determination will be described later. The drive control unit 55 controls the drive of the motor 10 by controlling the on and off actions of the switch elements 411 to 413.

[0084] Hereinafter, the case where the fault phase is the U phase is taken as an example, and the abnormality detection is mainly described. The voltage detection circuit 46 has a voltage-dividing resistor (not shown) corresponding to each phase, and the abnormality determination unit 52 determines the fault phase based on the voltage level of the intermediate connection point of the voltage-dividing resistor of the voltage detection circuit 46. Hereinafter, the voltage level of the intermediate connection point of the voltage-dividing resistor is referred to as the "port level".

[0085] When the coils 111 to 113 are normal, the motor relay 91 is turned on, and the switch elements 411 to 413 are turned off, the port level becomes a voltage level corresponding to the battery voltage and the resistance value of the voltage-dividing resistor (hereinafter referred to as "high level"). Figure 6 As shown by the dotted ellipse in FIG. 1 , if a disconnection occurs in the U-phase power supply line, the U-phase port level becomes a low level. Figure 7 and Figure 8 As shown in FIG. 1 , when a ground fault occurs in the current supply line of the U phase, the port level of the U phase also becomes a low level.

[0086] In this embodiment, if Figure 7 As shown, the power line and the ground are set to be (completely) short-circuited to the ground with a resistance of ≈ 0. Figure 8 As shown in FIG. 1 , the power supply line and the grounding line are set to an incomplete ground short circuit in a state where there is resistance conduction. Figure 7 , Figure 8 and the following Fig. 9 , Fig.10 , the ground short-circuit state is schematically depicted as a circuit surrounded by an ellipse with a dotted line.

[0087] Reference Fig. 9 The fault phase determination process based on the port level is described with reference to the flowchart of FIG. This process is executed by the control unit 50 at a predetermined period (e.g., 8 [ms]). Hereinafter, the "steps" such as step S101 are omitted and simply referred to as "S".

[0088] In S101, the control unit 50 determines whether all phases are deenergized. If it is determined that all phases are not deenergized (No in S101), the process after S102 is skipped. If it is determined that all phases are deenergized (Yes in S101), the process proceeds to S102.

[0089] In S102, the abnormality determination unit 52 determines whether the port level of the U phase is at a high level. Here, when it is above the determination threshold value set according to the battery voltage and the resistance value of the voltage-dividing resistor, it is determined to be at a high level, and when it is less than the determination threshold value, it is determined to be at a low level. When it is determined that the port level of the U phase is at a low level (S102 is no), the process moves to S103 and sets the U phase fault flag to ON. When it is determined that the port level of the U phase is at a high level (S102 is yes), the process moves to S104.

[0090] In S104, the abnormality determination unit 52 determines whether the port level of the V phase is at a high level. If it is determined that the port level of the V phase is at a low level (S104 is No), the process moves to S105 and turns on the V phase fault flag. If it is determined that the port level of the V phase is at a high level (S104 is Yes), the process moves to S106.

[0091] In S106, the abnormality determination unit 52 determines whether the port level of the W phase is at a high level. If it is determined that the port level of the W phase is at a low level (S106 is No), the process proceeds to S107 and the W phase fault flag is turned on. If it is determined that the port level of the W phase is at a high level (S106 is Yes), the process proceeds to S108.

[0092] In S108, the abnormality determination unit 52 determines whether two or more phases have failed. If it is determined that the failed phase is one phase or less (S108: No), the process proceeds to S112. If it is determined that two or more phases have failed (S108: Yes), the process proceeds to S109.

[0093] In S109, the abnormality determination unit 52 turns on the two-phase or more fault flag. In S110, the control unit 50 prohibits energization of all phases, and in S111, displays a warning to a dashboard (not shown). The method of displaying the warning is not limited, and the warning may be performed by sound or the like.

[0094] In S112, the abnormality determination unit 52 determines whether there is a 1-phase fault. If it is determined that there is a 1-phase fault (S112 is yes), the process moves to S113 and the 1-phase fault flag is turned on. If it is determined that there is no 1-phase fault (S112 is no), that is, if all phases are normal, the process moves to S114 and the normal flag is turned on.

[0095] exist Fig. 9 In the processing, although the fault phase can be determined, it is impossible to distinguish whether the fault is a disconnection fault or a power-on fault caused by a ground short circuit. Here, if the fault is a 1-phase disconnection, the normal 2 phases can be used for gear switching.

[0096] On the other hand, if the fault is a permanent power-on fault caused by a ground short circuit or the like, the gear shift cannot be performed using the normal two phases. In addition, if the motor relay 91 remains on, the current will continue to flow to the faulty phase, and the motor 10 may overheat. Therefore, it is desirable to disconnect the motor relay 91 and stop the drive control of the motor 10 in the event of a permanent power-on fault.

[0097] For example, as a reference example, after the fault phase is determined based on the port level, the gear switching can be implemented by using the normal two phases to switch the open circuit drive of the energized phase at a predetermined time, and the disconnection or ground short circuit can be determined based on whether the gear switching is successful. However, this method has the concern of distinguishing and determining delays. In addition, if Figure 8 As shown, if the shift position can be switched in the case of an incomplete ground short circuit in which a small amount of current flows on the ground side and the motor drive control is continued by mistakenly determining that the wire is broken, the motor 10 may overheat.

[0098] Therefore, in this embodiment, after the fault phase is identified based on the port level, a disconnection fault and a ground fault are distinguished based on the behavior when the switching elements 411 to 413 are turned on and off.

[0099] First, the detection value of the current detection unit 45 when the switch element 411 of the U phase, which is the fault phase, is turned on will be described. When the U phase is disconnected, even if the switch element 411 is turned on, the current does not flow to the U phase current line, so the current detection unit 45 does not detect the current (see Figure 6 ).

[0100] like Fig.10 and Fig.11 As shown by the arrow Isa in the middle, when the switch element 411 is turned on during a ground short circuit, current flows to the switch element 411. When the ground short circuit is incomplete and the resistance value of the short circuit portion is relatively large, a relatively large current flows to the current detection unit 45 side (refer to Fig.10 ). Therefore, when the U-phase fails, a disconnection and an incomplete ground short circuit can be distinguished based on the detection value of the current detection unit 45 when the switching element 411 is turned on.

[0101] In addition, if Fig.11 As shown in FIG. 1 , if the resistance at the ground short-circuit portion is close to 0, the current flowing to the current detection unit 45 side becomes small. Therefore, when the resistance at the ground short-circuit portion is close to 0, it is difficult to distinguish whether it is a wire break or a ground short-circuit based on the detection value of the current detection unit 45 when the switch element 411 is turned on. Fig.10 and Fig.11 In FIG. 1 , the amount of current is schematically indicated by the thickness of the arrow.

[0102] Therefore, in this embodiment, in addition to setting the current value when the switching element of the faulty phase is turned on, abnormality determination is performed based on the motor rotation angle when power is supplied to the normal phase. Before describing abnormality determination using the motor rotation angle, the behavior of the rotor 103 when power is supplied is described. Fig.12 In FIG. 1 , the horizontal axis is the motor rotation angle, and the vertical axis is the coil attraction force, showing the coil attraction force when power is supplied to the V phase. Fig.12 In the figure, the V-phase salient pole 102 of the stator 101 faces the concave portion 105 of the rotor 103 at the position of the circle, and the V-phase salient pole 102 faces the convex portion 104 of the rotor 103 at the position of the square.

[0103] When the switch element 412 is turned on and only the V phase is energized, the magnetic attraction acts to move the convex portion 104 toward the salient pole 102 of the V phase, except when the concave portion 105 is opposite to the salient pole 102 of the V phase at the position of the circle. Fig.12 In the figure, the attraction force when the V phase is energized is schematically indicated by a dotted arrow. In the area recorded as "+", it acts as a force to rotate the rotor 103 in the positive direction, and in the area recorded as "-", it acts as a force to rotate the rotor 103 in the negative direction.

[0104] based on Figure 13 to Figure 16 The behavior of the rotor 103 when the energization mode of the V-phase and W-phase, which are normal phases, is switched when the U-phase fails will be described. Fig.13 and Fig.14 Shows the behavior when the U phase is disconnected. Fig.15 and Fig.16 It shows the behavior when the U phase is short-circuited to ground.

[0105] exist Figure 13 to Figure 16 In the figure, the switching elements 411 to 413 of all phases are set to the disconnected state, i.e., the energized state ST11, the switching element 412 of the V phase is set to the connected state, i.e., the energized state ST12, the switching elements 412 and 413 of the V phase and the W phase are set to the connected state, i.e., the energized state ST13, and the switching element 413 of the W phase is set to the connected state, i.e., the energized state ST14, and the energized phases are switched in this order for explanation. In addition, when the switching element 411 of the U phase is turned on when the U phase is disconnected, the behavior is the same as when all phases are disconnected.

[0106] in addition, Figure 13 to Figure 16 The left part is for Figure 4The portion surrounded by the dotted line L in the figure schematically shows the positional relationship between the stator salient pole 102 and the rotor 103 by setting the rotation direction to the left and right directions, with the left direction being the positive rotation direction and the right direction being the negative rotation direction. In the figure on the left, the phase that is not energized due to a wire break (in the example of a U-phase wire break, the U-phase) is marked with an × mark, and the energized phase is shown with a pear skin pattern. In addition, the right side shows the difference in the motor rotation angle when the energized phase is switched, that is, the rotation angle difference Δθ. Fig.30 The same goes for etc.

[0107] Fig.13 The figure shows a case where the concave portion 105 of the rotor 103 is not opposite to V when the U phase is disconnected and all phases are disconnected. When all phases are disconnected in the energized state ST11, the attraction force of the motor winding 11 is not generated, so the position of the rotor 103 becomes uncertain. In addition, when the U phase is disconnected, even if the switching element 411 of the U phase is turned on, the motor winding 11 is not energized, so the same state is achieved.

[0108] When the V-phase switching element 412 is turned on to energize the V-phase by changing from the energized state ST11 to ST12, the coil 112 is energized to generate an attractive force, so that the convex portion 104 of the rotor 103 rotates to a position opposite to the V. In the energized state ST11, the rotor position is uncertain, so the rotation angle difference Δθ when changing from the energized state ST11 to ST12 becomes a value corresponding to the rotor position in the energized state ST11.

[0109] When the energized state ST12 is changed to ST13 and the switching elements 412 and 413 of the V phase and the W phase are turned on to energize the VW phase, the coils 112 and 113 are energized, and the convex portion 104 rotates by +7.5° to a position opposite to the V phase and the W phase. That is, the rotation angle difference Δθ when the energized state ST12 is changed to ST13 is +7.5°.

[0110] When the energized state ST13 is changed to ST14 and the switching element 412 of the V phase is turned off and the switching element 413 of the W phase is turned on to energize the W phase, the coil 113 is energized and the convex portion 104 rotates by +7.5° to a position opposite to W. That is, the rotation angle difference Δθ when the energized state ST12 is changed to ST13 is +7.5°.

[0111] Fig.14The figure shows the situation where the concave portion 105 of the rotor 103 faces V when the U phase is broken and all phases are disconnected. When the V phase is energized by turning on the switch element 412 of the V phase from the energized state ST11 to ST12, the coil 112 is energized. If the concave portion 105 faces V in the energized state ST11, the convex portions 104 on the left and right are pulled by the V phase, so the concave portion 105 remains facing V and the rotor 103 does not rotate. That is, the rotation angle difference Δθ when the energized state ST11 is changed to ST12 is 0°.

[0112] When the switching elements 412 and 413 of the V and W phases are turned on from the energized state ST12 to ST13, the coils 112 and 113 are energized, and the convex portion 104 rotates by -15° to a position facing the V and W phases. That is, the rotation angle difference Δθ when the energized state ST12 is changed to ST13 is -15°.

[0113] When the energized state ST13 is changed to ST14 and the switch element 412 of the V phase is turned off and the switch element 413 of the W phase is turned on, the coil 113 is energized and the convex portion 104 rotates +7.5° to a position opposite to W. Fig.13 Likewise, the rotation angle difference Δθ when the energization state ST12 is changed to ST13 is +7.5°.

[0114] Fig.15 The figure shows a situation where the U phase is short-circuited to the ground and the U phase coil 111 is energized so that the convex portion 104 faces the U phase. When the energized state ST11 is changed to ST12 and the switch element 412 of the V phase is turned on, the UV phase is energized and the convex portion 104 rotates by +7.5° to a position facing the U phase and the V phase. That is, the rotation angle difference Δθ when the energized state ST11 is changed to ST12 is +7.5°.

[0115] When the V-phase and W-phase switching elements 412 and 413 are turned on from the energized state ST12 to ST13, the W-phase is energized, but the rotor 103 does not rotate because the W-phase faces the recess 105. That is, the rotation angle difference Δθ when the energized state ST12 is changed to ST13 is 0°.

[0116] When the energized state ST13 is changed to ST14 and the switch element 412 of the V phase is turned off and the switch element 413 of the W phase is turned on, the WU phase is energized, and the convex portion 104 rotates by -15° to a position opposite to the U phase and the W phase. That is, the rotation angle difference Δθ when the energized state ST13 is changed to ST14 is -15°.

[0117] Fig.16The figure shows a situation in which the U phase is short-circuited to the ground and the U phase coil 111 is energized so that the concave portion 105 faces the U phase. When the energized state ST11 is changed to ST12 and the switch element 412 of the V phase is turned on, the UV phase is energized and the convex portion 104 rotates by -15° to a position facing the U phase and the V phase. That is, the rotation angle difference Δθ when the energized state ST11 is changed to ST12 is -15°.

[0118] When the V-phase and W-phase switching elements 412 and 413 are turned on from the energized state ST12 to ST13, the W-phase is energized, but the rotor 103 does not rotate because the W-phase faces the recess 105. That is, the rotation angle difference Δθ when the energized state ST12 is changed to ST13 is 0°.

[0119] When the energized state ST13 is changed to ST14, the switch element 412 of the V phase is turned off and the switch element 413 of the W phase is turned on, the WU phase is energized, and the convex portion 104 rotates -15° to a position opposite to the U phase and the W phase. Fig.15 Similarly, the rotation angle difference Δθ when the energization state ST13 is changed to ST14 is -15°.

[0120] Fig.17 1 is a diagram for explaining the rotation angle difference Δθ corresponding to the switching of the energization states ST11 to ST14. Fig.17 Mode 1 in Fig.13 Correspondingly, in the energizing state ST11, the concave portion 105 is not opposite to the concave portion 105 which is energized in the energizing state ST12. Fig.14 Correspondingly, this is a mode in which the concave portion 105 is opposite to the concave portion 105 in the energizing state ST11 and is energized in the energizing state ST12. Fig.15 Correspondingly, in the energized state ST11, the convex portion 104 faces the always-energized fault. Fig.16 Correspondingly, in the energized state ST11, the concave portion 105 faces the always-energized fault.

[0121] like Fig.17As shown, when the energized phase is switched to the energized state ST11 to ST14, regardless of the rotor position in the energized state ST11, when the energized state ST13 is changed to ST14, the rotation direction of the rotor 103 is different in the case of a U-phase disconnection and a ground short circuit, so it is possible to distinguish between a disconnection and a ground short circuit. In particular, in the case of a ground short circuit in a state of low resistance that is difficult to distinguish by the current value when the faulty phase is connected, the energized state of the normal 1-phase switch element when it is turned on is closer to the 2-phase energized state, and the encoder output is easy to stabilize in the same state as when the 2-phase is energized, so it is easy to distinguish.

[0122] In addition, when all phases are normal, when switching from the energized state ST13 to ST14, the behavior is the same as when the line is disconnected. Therefore, it can also be understood that the rotor rotation direction during ground short circuit when switching from the energized state ST13 to ST14 is different from the rotation direction when all phases are normal.

[0123] based on Fig.18 and Fig.19 The flowchart of the power-on process involved in fault determination is described. In S201, the control unit 50 determines whether the always-on fault flag FlgA described later is turned on. When it is determined that the always-on fault flag FlgA is turned on (S201 is yes), the process after S202 is skipped. When it is determined that the always-on fault flag FlgA is turned off (S201 is no), it moves to S202.

[0124] In S202, the control unit 50 determines whether the 2-phase pre-switching energization processing flag FlgP is turned on. If it is determined that the 2-phase pre-switching energization processing flag FlgP is turned on (S202 is yes), the process proceeds to S210. If it is determined that the 2-phase pre-switching energization processing flag is off (S202 is no), the process proceeds to S203.

[0125] In S203, the control unit 50 determines whether there is a shift position switching request. If it is determined that there is no shift position switching request (S203: No), the processing after S204 is skipped. If it is determined that there is a shift position switching request (S203: Yes), the process proceeds to S204.

[0126] In S204, the control unit 50 determines whether the 1-phase fault flag is turned on. Fig. 9 If it is determined that the 1-phase fault flag is turned off (S204 is No), the processing after S205 is skipped. If it is determined that the 1-phase fault flag is turned on (S204 is Yes), the process moves to S205.

[0127] In S205, the control unit 50 determines whether the motor relay 91 is turned on. If it is determined that the motor relay 91 is not turned on (S205: No), the process proceeds to S206 to turn on the motor relay 91. If it is determined that the motor relay 91 is turned on (S205: Yes), the process proceeds to S207.

[0128] In S207, the control unit 50 considers the delay in turning on the motor relay 91 and determines whether the standby time has passed since the motor relay 91 was turned on. If it is determined that the standby time has not passed since the motor relay 91 was turned on (S207: No), the processing after S208 is skipped. If it is determined that the standby time has passed since the motor relay 91 was turned on (S207: Yes), the process proceeds to S208.

[0129] In S208, the control unit 50 turns on the 2-phase pre-switching energization processing flag FlgP and turns off the 2-phase pre-switching energization processing completion flag FlgC. In S209, the control unit 50 turns the state to the energization state ST11.

[0130] like Fig.19 As shown, in S210, the control unit 50 determines whether the current state is the power-on state ST11. If it is determined that the current state is not the power-on state ST11 (S210: No), the process proceeds to S213. If it is determined that the current state is the power-on state ST11 (S210: Yes), the process proceeds to S211.

[0131] In S211, the control unit 50 determines whether the duration X11 has passed since the start of the power-on state ST11. If it is determined that the duration X11 has passed (S211: Yes), the state is set to the power-on state ST12 and the process proceeds to S215. If it is determined that the duration X11 has not passed (S211: No), the process proceeds to S212.

[0132] In S212, the control unit 50 performs power-on in the power-on state ST11. The power-on state ST11 is power-on of the fault phase. When the U-phase fault flag is turned on, the switch element 411 of the U-phase is turned on, when the V-phase fault flag is turned on, the switch element 412 of the V-phase is turned on, and when the W-phase fault flag is turned on, the switch element 413 of the W-phase is turned on.

[0133] In S213, which is the process of moving to the control unit 50 when it is determined that the current state is not the power-on state ST11 (S210 is No), the control unit 50 determines whether the current state is the power-on state ST12. If it is determined that the current state is not the power-on state ST12 (S213 is No), the process moves to S216. If it is determined that the current state is the power-on state ST12 (S213 is Yes), the process moves to S214.

[0134] In S214, the control unit 50 determines whether the duration X12 has passed since the start of the power-on state ST12. If it is determined that the duration X12 has passed (S214: Yes), the state is set to the power-on state ST13 and the process proceeds to S218. If it is determined that the duration X12 has not passed (S214: No), the process proceeds to S215.

[0135] In S215, the control unit 50 performs power-on in the power-on state ST12. The power-on state ST12 is that the normal phase 1 is powered on, and when the U phase fault flag is turned on, the switch element 412 of the V phase is turned on, when the V phase fault flag is turned on, the switch element 413 of the W phase is turned on, and when the W phase fault flag is turned on, the switch element 411 of the U phase is turned on.

[0136] In S216, which is the process that moves to the state when it is determined that the current state is not the power-on state ST12 (S213 is No), the control unit 50 determines whether the current state is the power-on state ST13. If it is determined that the current state is not the power-on state ST13 (S216 is No), the process moves to S219. If it is determined that the current state is the power-on state ST13 (S216 is Yes), the process moves to S217.

[0137] In S217, the control unit 50 determines whether the duration X13 has passed since the start of the power-on state ST13. If it is determined that the duration X13 has passed (S217: Yes), the state is set to the power-on state ST14 and the process proceeds to S220. If it is determined that the duration X13 has not passed (S217: No), the process proceeds to S218.

[0138] In S218, the control unit 50 performs power-on in the power-on state ST13. The power-on state ST13 is a normal two-phase power-on state. When the U-phase fault flag is turned on, the switch elements 412 and 413 of the V-phase and W-phase are turned on. When the V-phase fault flag is turned on, the switch elements 411 and 413 of the U-phase and W-phase are turned on. When the W-phase fault flag is turned on, the switch elements 411 and 412 of the U-phase and V-phase are turned on.

[0139] In S219, which is transferred to when it is determined that the power-on state ST13 is not in progress (S216 is No), the control unit 50 determines whether the duration X14 has passed since the start of the power-on state ST14. The durations X11 to X14 can be set arbitrarily, and may be at least partially the same or different. When it is determined that the duration X14 has passed (S219 is No), the process proceeds to S221. When it is determined that the duration X14 has not passed (S219 is Yes), the process proceeds to S220.

[0140] In S220, the control unit 50 performs power-on in the power-on state ST14. The power-on state ST14 is a single-phase power-on performed on a normal phase different from the power-on state ST12. When the U-phase fault flag is turned on, the W-phase switch element 413 is turned on. When the V-phase fault flag is turned on, the U-phase switch element 411 is turned on. When the W-phase fault flag is turned on, the V-phase switch element 412 is turned on.

[0141] In S221 to which the control unit 50 moves after the duration X14 has passed since the start of the power-on state ST14, the control unit 50 sets the 2-phase switching pre-power-on processing flag FlgP to off and sets the 2-phase switching pre-power-on completion flag FlgC to off. In S222, the control unit 50 sets the power-on state to undetermined ST0. The power-on phase in the normal 1-phase power-on of the power-on states ST12 and ST14 can be set arbitrarily, and it can be distinguished whether the line is disconnected or always powered based on the rotation direction corresponding to the set power-on phase.

[0142] based on Fig. 20 The fault state determination process is explained with reference to the flowchart of. In S501, the abnormality determination unit 52 determines whether the 2-phase switching before power-on completion flag FlgC is turned on. When it is determined that the 2-phase switching before power-on completion flag FlgC is turned on (S501 is yes), the process moves to S510. When it is determined that the 2-phase switching before power-on completion flag FlgC is turned off (S501 is no), the process moves to S502.

[0143] In S502, the abnormality determination unit 52 determines whether the current state is the power-on state ST11. If it is determined not to be the power-on state ST11 (S502: No), the process proceeds to S504. If it is determined to be the power-on state ST11 (S502: Yes), the process proceeds to S503.

[0144] In S503, the abnormality determination unit 52 determines whether the state in which the motor current Im is above the current determination threshold value Ith continues for more than the determination time Xi. The current determination threshold value Ith is set according to the current flowing through the current detection unit 45 when a ground short circuit occurs. In addition, the determination time Xi is set to a time shorter than the duration X11. In the case where it is determined that the motor current Im is less than the current determination threshold value Ith or the duration in which the motor current Im is above the current determination threshold value Ith is less than the determination time Xi (S503 is No), the subsequent processing is skipped. In the case where it is determined that the state in which the motor current Im is above the current determination threshold value Ith continues for more than the determination time Xi (S503 is Yes), it moves to S511.

[0145] In S504, the abnormality determination unit 52 determines whether the current state is the power-on state ST13. If it is determined not to be the power-on state ST13 (S504: No), the process proceeds to S507. If it is determined to be the power-on state ST13 (S504: Yes), the process proceeds to S505.

[0146] In S505, the abnormality determination unit 52 determines whether the standby time Xw13 has passed since the power-on state ST13. The standby time Xw13 is set according to the time required for the vibration of the rotor 103 to calm down to a certain extent in the power-on state ST13. In the case where it is determined that the standby time Xw13 has not passed since the power-on state ST13 (S505 is No), the subsequent processing is skipped. In the case where it is determined that the standby time Xw13 has passed since the power-on state ST13 (S505 is Yes), the process moves to S506 and performs the update processing of the maximum value CTmax13 in the power-on state ST13. The update processing of the maximum value CTmax13 will be described later.

[0147] In S507, the abnormality determination unit 52 determines whether the current state is the power-on state ST14. If it is determined not to be the power-on state ST14 (S507: No), the subsequent processing is skipped. If it is determined to be the power-on state ST14 (S507: Yes), the process proceeds to S508.

[0148] In S508, the abnormality determination unit 52 determines whether the standby time Xw14 has passed since the power-on state ST14. The standby time Xw14 is set according to the time required for the vibration of the rotor 103 to calm down to a certain extent in the power-on state ST14, and may be the same as or different from the standby time Xw13. The same applies to the standby time Xw12 and the like in the later-described embodiments. In the case where it is determined that the standby time Xw14 has not passed since the power-on state ST14 (S508 is No), the subsequent processing is skipped. In the case where it is determined that the standby time Xw14 has passed since the power-on state ST14 (S508 is Yes), the process moves to S509 and performs the updating process of the minimum value CTmin14 in the power-on state ST14.

[0149] based on Figure 21 to Figure 23 The updating process of the maximum value CTmax13 in the energizing state ST13 and the updating process of the minimum value CTmin14 in the energizing state ST14 will be described. Fig.21This is a diagram for explaining the behavior of the rotor 103 in the power-on states ST11 to ST14, with the horizontal axis being time and the vertical axis being the motor rotation angle. Here, as an example, the behavior when the U phase is disconnected is shown. In addition, in this embodiment, the rotation position of the rotor 103 is detected using the encoder 13, and the rotation angle is obtained by converting the encoder count value. Hereinafter, the rotation angle is appropriately referred to as the encoder count value.

[0150] After the start of the power-on state ST13, the maximum value CTmax13 is updated from the moment xa after the waiting time Xw13 for waiting for the vibration of the rotor 103 to decrease has passed until the transition to the power-on state ST14. In addition, after the start of the power-on state ST14, the minimum value CTmin14 is updated from the moment xb after the waiting time Xw14 for waiting for the vibration of the rotor 103 to decrease has passed until the end of the power-on state ST14. The power-on state ST14 is a one-phase power-on state, and it takes more time for the vibration of the rotor 103 to decrease than the power-on state ST13 as a two-phase power-on state, so the waiting time Xw14 is set to be longer than the waiting time Xw13.

[0151] Maximum value CTmax13 of power-on state ST13 is updated ( Fig. 20 The sub-process of S506 in Fig. 22 In S561, the abnormality determination unit 52 determines whether it is the first calculation after the waiting time Xw13 has passed. If it is determined that it is the first calculation after the waiting time Xw13 has passed (S561 is yes), the process moves to S562, and the current encoder count value EN is set to the maximum value CTmax13. If it is determined that it is not the first calculation after the waiting time Xw13 has passed (S561 is no), the process moves to S563.

[0152] In S563, the abnormality determination unit 52 determines whether the current encoder count value EN is greater than the maximum value CTmax13. When it is determined that the current encoder count value EN is less than the maximum value CTmax13 (S563 is No), the value stored as the maximum value CTmax13 is not updated, and this process ends. When it is determined that the current encoder count value EN is greater than the maximum value CTmax13 (S563 is Yes), the process moves to S564, and the maximum value CTmax13 is updated as the current encoder count value EN.

[0153] The minimum value CTmin14 of the power-on state ST14 is updated ( Fig. 20 The sub-process of S509) in Fig.23In S591, the abnormality determination unit 52 determines whether it is the first operation after the waiting time Xw14 has passed. If it is determined that it is the first operation after the waiting time Xw14 has passed (S591 is yes), the process moves to S592, and the current encoder count value EN is set to the minimum value CTmin14. If it is determined that it is not the first operation after the waiting time Xw13 has passed (S591 is no), the process moves to S593.

[0154] In S593, the abnormality determination unit 52 determines whether the current encoder count value EN is smaller than the minimum value CTmin14. When it is determined that the current encoder count value EN is greater than the minimum value CTmin14 (S593 is No), the value stored as the minimum value CTmin14 is not updated, and this process ends. When it is determined that the current encoder count value EN is smaller than the minimum value CTmin14 (S593 is Yes), the process moves to S594, and the minimum value CTmin14 is updated to the current encoder count value EN.

[0155] Return to Fig. 20 In S510, when it is determined that the 2-phase switching pre-energization processing completion flag FlgC is turned on (S501 is yes), the abnormality determination unit 52 determines whether the value obtained by subtracting the maximum value CTmax13 of the energization state ST13 from the minimum value CTmin14 of the energization state ST14 is less than the determination threshold TH. The determination threshold TH can be set to an arbitrary value that can distinguish whether the rotation direction is different depending on whether it is a one-phase disconnection or a ground short circuit, for example, it is set to 0 or a value close to 0. When it is determined that the value obtained by subtracting the maximum value CTmax13 from the minimum value CTmin14 is less than the determination threshold TH (S510 is yes), that is, when the rotation direction of the rotor 103 when the energization state ST13 is changed to ST14 is negative, the process proceeds to S511. When it is determined that the value obtained by subtracting the maximum value CTmax13 from the minimum value CTmin14 is greater than the determination threshold TH (S510 is no), the process proceeds to S514.

[0156] When it is determined that the motor current Im in the power-on state ST11 is above the current judgment threshold value Ith for a period of time Xi or longer (Yes in S503) or when it is determined that the value obtained by subtracting the maximum value CTmax13 from the minimum value CTmin14 is below the judgment threshold value TH after the power-on process before the two-phase switching is completed (Yes in S510), the abnormality judgment unit 52 determines that a power-on fault caused by a ground short circuit or the like has occurred, and sets the power-on fault flag FlgA to on. The processing of S512 and S513 is the same as that of Fig. 9 The processing of S110 and S111 is the same as that of S110, S111, in which energization of all phases is prohibited and a warning display is performed.

[0157] When it is determined that the value obtained by subtracting the maximum value CTmax13 from the minimum value CTmin14 is greater than the determination threshold value TH (S510 is No), the abnormality determination unit 52 determines whether the always-on fault flag FlgA is off in S514. When it is determined that the always-on fault flag FlgA is on (S514 is No), the processing of S515 is skipped. When it is determined that the always-on fault flag FlgA is off (S515 is Yes), the process proceeds to S515 and the 1-phase disconnection fault flag FlgD is turned on.

[0158] based on Fig.24 The timing diagram of FIG. 1 is used to illustrate the shift switching process of this embodiment. Fig.24 In the figure, the common time axis is set as the horizontal axis, and from the upper section, the 1-phase fault flag, the requested shift position, the on / off state of the motor relay 91, the 2-phase switching pre-power-on processing flag FlgP, the power-on state, the always-power-on fault flag FlgA, the 1-phase disconnection flag FlgD, and the 2-phase switching pre-power-on completion flag FlgC are shown. In the embodiment described later Fig.29 Same here.

[0159] At time x50, if a phase failure occurs and the phase failure flag is turned on by the failure phase determination process, the motor relay 91 is turned off. At time x51, if a shift position switching request is generated, the requested shift position is changed from the P position to the notP position, and the motor relay 91 is turned on.

[0160] At time x52, if the 2-phase switching pre-energization processing flag FlgP is turned on, the energization state ST11 is set, and the fault phase is energized. At time x53, if it is determined that it is a constant energization fault based on the motor current Im, the constant energization fault flag FlgA is turned on as shown by the single-dot chain line, and the motor relay 91 is disconnected. In addition, if it is determined that it is a constant energization fault caused by a ground short circuit in the energization state ST11, the processing after the energization state ST12 and the normal 2-phase shift switching are not performed.

[0161] If the power-on state ST11 is not determined to be a permanent power-on failure, power-on in the power-on states ST12, ST13, and ST14 is performed in sequence. Fig.24 In the figure, for simplicity, the timing when the always-on fault flag FlgA is turned on is aligned with the timing of switching from the energizing state ST11 to ST12, but in reality, the transition to the energizing state ST12 is set to be slower.

[0162] If the energized state ST14 ends at time x54, the 2-phase switching pre-energization completion flag FlgC is turned on. Here, if it is determined that the power-on fault is always on based on the maximum value CTmax13 of the energized state ST13 and the minimum value CTmin14 of the energized state ST14, the power-on fault flag FlgA is turned on as shown by the double-dashed line, and the motor relay 91 is disconnected. In addition, if it is not determined that the power-on fault is always on based on the maximum value CTmax13 and the minimum value CTmin14, it is determined that the 1-phase line is broken, and the 1-phase line is broken flag FlgD is turned on as shown by the solid line.

[0163] When it is determined that the fault in the faulty phase is not always energized due to a ground short circuit but is a phase disconnection, the two phases with normal encoders are used to perform gear switching using feedback control based on encoder count values.

[0164] In the gear shifting drive, the energized phase of the motor winding 11 is switched by using feedback control based on the encoder count value, thereby driving the motor 10. Fig.25 As shown, the control unit 50 has a correspondence table that associates the energized phase number with the energization, and each time a pulse edge of the encoder signal is detected, the energized phase number is shifted by 1, and the energized phase is switched to rotate the motor 10. When the motor 10 is rotated in the forward direction, the energized phase number is increased by 1 each time a pulse edge of the encoder signal is detected, and when the motor 10 is rotated in the reverse direction, the energized phase is decreased by 1. The energized phase number can also be understood as the remainder when the encoder count value is divided by 12, for example.

[0165] Under normal circumstances, when a stagnation abnormality such as a stagnation of the encoder count value occurs, the motor 10 is rotated by switching the energized phase at a predetermined time through an open circuit drive. In the open circuit drive, in order to reliably position the convex portion 104 of the rotor 103 at the energized phase and synchronize the rotation phase of the rotor 103 with the energized phase, the excitation time of each energized phase is set to a relatively long time (for example, 50 [ms]).

[0166] In the case of a one-phase disconnection, the motor 10 is driven by energizing the normal two phases based on feedback control to switch gears. For example, if the U phase is disconnected, when the energized phase number is "0" or "1", the W phase is energized, and when the energized phase number is "4" or "5", the V phase is energized. In addition, in the area of ​​energized phase numbers "2" and "3" that are not energized when the U phase is disconnected, although no torque is generated, the motor 10 can continue to be driven by passing through this area under inertia.

[0167] When a stagnation abnormality occurs when the motor is driven by the normal two phases when one phase is disconnected, if the motor 10 is driven by the open circuit drive whose motor rotation speed is lower than the feedback control, there is a concern that the motor 10 may not pass through the area corresponding to the disconnection under inertia. Therefore, in this embodiment, when a stagnation abnormality occurs when the gear is switched by the two phases when one phase is disconnected, the open circuit drive is not switched, but it is determined as a gear switching abnormality.

[0168] based on Fig.26 The timing diagram is used to illustrate the gear switching process when one phase is disconnected. Fig.26 In , set the public time axis as the horizontal axis. Fig.24 The lower part of each item shows the encoder count value and the system diagnosis flag. As for the encoder count value, the value when the locking roller 26 is embedded in the valley portion 211 is recorded as "P", and the value when the locking roller 26 is embedded in the valley portion 212 is recorded as "notP".

[0169] Processing of time x60 to time x63 Fig.24 The same process is applied to the case of a one-phase disconnection at moments x20 to x24. At moment x63, if it is determined that one phase is disconnected, the gear shift is performed using the normal two phases. At moment x64, the encoder count value stagnates before the locking roller 26 reaches the valley 212 as the target valley. At moment x65 after the stagnation determination time has passed, the drive is not switched to open circuit drive, but the switching elements 411 to 413 are set to be disconnected to disconnect the power to the motor 10, and the motor relay 91 is set to be disconnected. In addition, the system diagnostic flag is set to on.

[0170] In this embodiment, after the fault phase is determined based on the port level when the switch elements 411 to 413 are turned off, it is determined whether it is a disconnection abnormality or a permanent power-on abnormality caused by a ground short circuit based on the current detection value when the switch element of the fault phase is turned on and the rotation position of the motor 10 when the power-on mode to the normal phase is switched. In this way, it is possible to appropriately distinguish whether a single-phase fault is a permanent power-on abnormality or a disconnection abnormality regardless of the degree of the ground short circuit.

[0171] As described above, the ECU 40 controls the driving of the motor 10 having the motor winding 11 of three or more phases, and includes the drive circuit 41 and the control unit 50. The drive circuit 41 includes the switching elements 411 to 413 for switching the energization of each phase of the motor winding 11 on and off.

[0172] The control unit 50 includes a drive control unit 55 and an abnormality determination unit 52. The drive control unit 55 controls the on and off operations of the switching elements 411 to 413. The abnormality determination unit 52 performs abnormality determination on the current supply path to the motor winding 11.

[0173] The control unit 50 is capable of obtaining the detection value of the voltage detection circuit 46 for detecting the phase voltage of the motor winding 11, namely the voltage detection value, the detection value of the current detection unit 45 for detecting the current supplied to the motor winding 11, namely the current detection value, and the detection value of the encoder 13 for detecting the rotational position of the motor 10, namely the encoder signal.

[0174] The abnormality determination unit 52 determines the faulty phase based on the voltage detection value when the switch elements 411 to 413 of all phases are turned off. The abnormality determination unit 52 determines the always-on fault of the faulty phase based on at least one of the current detection value when the switch element of the determined faulty phase is turned on and the rotation position detection value when the switch elements 411 to 413 of one or more phases of the normal phase are turned on.

[0175] This makes it possible to appropriately identify the fault state. Specifically, it is possible to appropriately distinguish whether the fault occurring in the faulty phase is a permanent energization fault caused by a ground short circuit or the like or a line disconnection fault in which power cannot be supplied to the faulty phase.

[0176] Here, if the fault state determination process based on the current detection value when the switching element of the faulty phase is connected is set as the "first fault state determination process", and the fault state determination process based on the rotation position detection value when the normal phase is energized is set as the "second fault state determination process", it can be understood that the fault state of the faulty phase is determined by implementing at least one of the first fault state determination process and the second fault state determination process.

[0177] In particular, in the present embodiment, by using the first fault state determination processing and the second fault state determination processing in combination, it is possible to prevent the always-on fault from being misjudged as a disconnection fault, regardless of the deviation in the degree of current flowing into the location where the always-on fault occurs (for example, the resistance during a ground short circuit).

[0178] The abnormality determination unit 52 determines that there is an always-on abnormality when the motor current Im when the switch element of the faulty phase is turned on is greater than the current determination threshold value Ith. By detecting the current on the downstream side of the switch element when the switch element of the faulty phase is turned on, it can be determined that there is no disconnection in the faulty phase when the current is flowing, that is, it can be determined that an always-on fault has occurred.

[0179] The abnormality determination unit 52 determines the always-on fault based on the change in the rotational position of the motor 10 when performing the first normal phase power-on process of powering one or more phases of the normal phase and the second normal phase power-on process, wherein the second normal phase power-on process is a process of powering one or more phases of the normal phase that is different from the first normal phase power-on process. In the present embodiment, the power-on state ST13 of powering two phases of the normal phase corresponds to the "first normal phase power-on process", and the power-on state ST14 of powering one phase of the normal phase corresponds to the "second normal phase power-on process". In detail, the abnormality determination unit 52 determines it as a always-on fault when the rotation direction when switching from the first normal phase power-on process to the second normal phase power-on process is different from that when all phases are normal. In this way, the always-on fault can be appropriately determined.

[0180] The drive control unit 55 performs a preliminary energization process of energizing one or more phases of at least one normal phase that is different from the first normal phase energization process before the first normal phase energization process. In the present embodiment, the energization state ST12 of energizing one phase of the normal phase corresponds to the "preliminary energization process". When energization is initially performed on any normal phase from a non-energized state, there are two positions where the rotor 103 becomes stationary under the balance of attraction according to the rotor position in the non-energized state, but it can be moved to the desired equilibrium position by the second energization. Therefore, in the present embodiment, by performing the first normal phase energization process and the second energized phase energization process after performing the preliminary energization process, it is possible to appropriately implement fault judgment regardless of the rotor position in the non-energized state.

[0181] The motor 10 is a three-phase motor. When the drive control unit 55 determines that the faulty phase is one phase and that the fault is not always energized, the motor 10 is driven by energizing the normal two-phase motor winding 11. Thus, the motor 10 can continue to be driven. In this embodiment, the shift-by-wire system 1 is applied, and the shift position can be switched when one phase is disconnected.

[0182] When all phases are normal and a stagnation abnormality such as a stagnation of the encoder count value occurs, the drive control unit 55 performs open circuit driving that switches the energized phase without using the encoder count value instead of feedback control based on the encoder count value. When the faulty phase is one phase and it is not a constant energization fault, the drive control unit 55 drives the motor 10 by energizing the normal two-phase motor winding 11 using feedback control, and stops the drive control of the motor 10 when a stagnation abnormality occurs.

[0183] When one phase is disconnected, the normal two phases are used for drive control, and the disconnected phase needs to be passed by inertia, and there is a concern that the motor 10 may stop under the open circuit drive with a relatively slow rotation speed. Therefore, when a stagnation abnormality occurs when one phase is disconnected, the open circuit drive is not switched to, but the unnecessary power supply is avoided by stop control.

[0184] (Second Embodiment)

[0185] The second embodiment is as follows Figure 27 to Figure 29 As shown in Fig.17 As described in , when the energized state ST12 of 1-phase energization is changed to the energized state ST13 of 2-phase energization, the motor rotation angle does not change when a ground short circuit occurs. Therefore, in this embodiment, when the motor rotation angle does not change when switching from 1-phase energization to 2-phase energization, it is determined to be a constant energization fault.

[0186] The power-on process involved in the fault determination of this embodiment is as follows: Fig. 27 In addition, since the first half is different from the first embodiment Fig.18 Likewise, therefore in Fig. 27 Shown in Fig.19 In this embodiment, since the power-on state ST14 is not performed, Fig. 27 S216, S219, and S220 are omitted in the Fig.19 Similarly, if a negative determination is made in S213, the process proceeds to S217, and if an affirmative determination is made in S217, the process proceeds to S221.

[0187] based on Fig.28 The flowchart of the fault state determination process is described. S601 to S603 and Fig. 20 The same is true for S501 to S503 in the above. In S604, which is moved to when a negative judgment is made in S602, the abnormality determination unit 52 determines whether the current state is the power-on state ST12. If it is determined that it is not the power-on state ST12 (S604 is No), the process moves to S607. If it is determined that it is the power-on state ST12 (S604 is Yes), the process moves to S605.

[0188] In S605, the abnormality determination unit 52 determines whether the standby time Xw12 has passed since the power-on state ST12. If it is determined that the standby time Xw12 has not passed since the power-on state ST12 (S605 is no), the subsequent processing is skipped. If it is determined that the standby time Xw12 has passed since the power-on state ST12 (S605 is yes), the process moves to S606, smoothing the count value, and calculating the smoothed count value CT12 (refer to formula (1)). The subscript (n) in the formula is the current value, and (n-1) is the previous value.

[0189] CT12 (n) =(2×CT12 (n-1) -EN) / 3 ··· (1)

[0190] In the case where it is determined that the current state is not the power-on state ST12 (S604 is No), the abnormality determination unit 52 determines whether the current state is the power-on state ST13 in S607. If it is determined that it is not the power-on state ST13 (S607 is No), the subsequent processing is skipped. If it is determined that it is the power-on state ST13 (S607 is Yes), the process proceeds to S608.

[0191] In S608, the abnormality determination unit 52 determines whether the standby time Xw13 has passed since the start of the power-on state ST13. If it is determined that the standby time Xw13 has not passed (S608 is No), the subsequent processing is skipped. If it is determined that the standby time Xw13 has passed (S608 is Yes), the process moves to S609, smoothing the count value is performed, and the count value CT13 after the smoothing process is calculated (refer to formula (2)).

[0192] CT13 (n) =(2×CT13 (n-1) -EN) / 3 ··· (2)

[0193] In S610, which is moved to when it is judged that the flag FlgC for completing the power-on process before the 2-phase switching is turned on (S601 is yes), the abnormality judgment unit 52 judges whether the absolute value of the difference between the count values ​​CT12 and CT13 after the smoothing process is greater than the difference judgment threshold ΔCTth. The difference judgment threshold ΔCTth is set to a value close to 0 so that it can be judged that the rotor 103 is not moving when the power-on state ST12 is changed to ST13. In the case where it is judged that the absolute value of the difference between the count values ​​CT12 and CT13 is smaller than the difference judgment threshold ΔCTth (S610 is no), it is judged to be a always-power-on fault and the process moves to S611. In the case where it is judged that the absolute value of the difference between the count values ​​CT12 and CT13 is greater than the difference judgment threshold ΔCTth (S610 is yes), it is judged to be not a always-power-on fault but a line break fault and the process moves to S614. S611 to S615 are the same as Fig. 20 The processing of S511 to S515 in is the same.

[0194] based on Fig.29 The shift switching process of this embodiment is described with reference to the timing diagram. When it is determined that the power-on failure is always detected in the power-on state ST11, the process is the same as that of the first embodiment, so the description is omitted. Fig.24 The processing at time x50 to time x52 is the same.

[0195] After time x62, power is supplied in power supply states ST11, ST12, and ST13 in sequence. At time x63, when power supply state ST13 ends, the power supply completion flag FlgC before two-phase switching is turned on. Here, if it is determined to be a power-on fault based on the difference between count values ​​CT12 and CT13, the power-on fault flag FlgA is turned on as shown by the double-dotted line, and the motor relay 91 is disconnected.

[0196] If the count values ​​CT12 and CT13 are not determined to be a constant-power failure, a single-phase disconnection is determined, and the single-phase disconnection flag FlgD is turned on as shown by the solid line. Fig.24 The same process applies after time x54.

[0197] In the present embodiment, as the second normal phase power-on process, when the change in the encoder count value is smaller than the difference determination threshold value ΔCTth when all the normal phase switch elements are turned on, it is determined as a always-on fault. In the present embodiment, the power-on state ST12 corresponds to the "first normal phase power-on process", and the power-on state ST13 corresponds to the "second normal phase power-on process". Thus, the always-on fault can be appropriately determined. In addition, the same effect as the above-mentioned embodiment is achieved.

[0198] (Third Embodiment)

[0199] The third embodiment is as follows Figure 30 to Figure 36 As shown. In the above embodiment, when one phase fails, the power-on state ST12 is set to 1-phase power-on, the power-on state ST13 is set to 2-phase power-on, and the power-on state ST14 is set to 1-phase power-on. Based on the motor rotation angle when the power-on phase is switched from 1-phase power-on to 2-phase power-on to 1-phase power-on, it is distinguished whether the fault phase is a broken wire or a ground short circuit. In this embodiment, the power-on states ST22 to ST24 are all set to 1-phase power-on, and the abnormal state of the fault phase is distinguished based on the motor rotation angle when the power-on phase is switched.

[0200] exist Figure 30 to Figure 33 In the figure, the switching elements 411 to 413 of all phases are set to the disconnected state, i.e., the energized state ST21, the switching element 412 of the V phase is set to the connected state, i.e., the energized state ST22, the switching element 413 of the W phase is set to the connected state, i.e., the energized state ST23, and the switching element 412 of the V phase is set to the connected state, i.e., the energized state ST24, and the energized phases are switched in this order for explanation. In addition, since the energized states ST21 and ST22 are the same as the energized states ST11 and 12 of the above-mentioned embodiment, the explanation is appropriately omitted.

[0201] Fig.30 The figure shows a case where the concave portion 105 of the rotor 103 is not opposite to V when the U phase is disconnected and all phases are disconnected. When the switching element 412 of the V phase is turned off and the switching element 413 of the W phase is turned on to switch to W phase energization from the energized state ST22 to ST23, the convex portion 104 of the rotor 103 rotates by +15° to a position opposite to W. That is, the rotation angle difference Δθ when the energized state ST22 is changed to ST23 is +15°.

[0202] When the energization state ST23 changes to ST24 and the V-phase switching element 412 is turned on and the W-phase switching element 413 is turned off to switch to the V-phase, the convex portion 104 rotates by -15° to a position facing V. That is, the rotation angle difference Δθ when the energization state ST23 changes to ST24 is -15°.

[0203] Fig.31 The figure shows a case where the concave portion 105 of the rotor 103 is opposite to V when the U phase is disconnected and all phases are disconnected. When the switching element 412 of the V phase is turned off and the switching element 413 of the W phase is turned on to switch to W phase energization from the energized state ST22 to ST23, the convex portion 104 rotates by -7.5° to a position opposite to W. That is, the rotation angle difference Δθ when the energized state ST22 is changed to ST23 is -7.5°.

[0204] When the energized state ST23 is changed to ST24, the switch element 412 of the V phase is turned on and the switch element 413 of the W phase is turned off to switch to the V phase, the convex portion 104 rotates by -15° to a position opposite to the V phase. Fig.30 Similarly, the rotation angle difference Δθ when the energization state ST23 changes to ST24 is -15.

[0205] Fig.32 The figure shows a case where the U phase is short-circuited to the ground and the U phase coil 111 is energized so that the convex portion 104 faces the U phase. When the energized state ST22 is changed to ST23 and the switch element 412 of the V phase is turned off and the switch element 413 of the W phase is turned on, the WU phase is energized and the convex portion 104 rotates by -15° to a position facing the U phase and the W phase. That is, the rotation angle difference Δθ when the energized state ST22 is changed to ST23 is -15°.

[0206] When the energized state ST23 is changed to ST24 and the switch element 412 of the V phase is turned on and the switch element 413 of the W phase is turned off, the UV phase is energized and the convex portion 104 rotates by +15° to a position opposite to the U phase and V. That is, the rotation angle difference Δθ when the energized state ST23 is changed to ST24 is +15°.

[0207] Fig.33 The figure shows a situation in which the U phase is short-circuited to the ground and the U phase coil 111 is energized so that the concave portion 105 faces the U phase. When the energized state ST22 is changed to ST23 and the switch element 412 of the V phase is turned off and the switch element 413 of the W phase is turned on, the WU phase is energized and the convex portion 104 rotates by -15° to a position facing the U phase and the W phase. That is, the rotation angle difference Δθ when the energized state ST22 is changed to ST23 is -15°.

[0208] When the energized state ST23 is changed to ST24, the switch element 412 of the V phase is turned on and the switch element 413 of the W phase is turned off, the UV phase is energized, and the convex portion 104 rotates +15° to a position opposite to the U phase and the V phase. Fig.32 Likewise, the rotation angle difference Δθ when the energization state ST23 changes to ST24 is +15°.

[0209] Fig.34 1 is a diagram for explaining the rotation angle difference Δθ corresponding to the switching of the energization states ST21 to ST24. Fig.34 Mode 1 in Fig.30Correspondingly, in the energizing state ST21, the concave portion 105 is not opposite to the concave portion 105 which is energized in the energizing state ST22. Fig.31 Correspondingly, this is a mode in which the concave portion 105 is opposite to the concave portion 105 in the energizing state ST21 and is energized in the energizing state ST22. Fig.32 Correspondingly, in the power-on state ST21, the convex portion 104 faces the always-on fault. Fig.33 Correspondingly, in the energized state ST21, the concave portion 105 faces the always-energized fault.

[0210] like Fig.34 As shown, when the energized phase is switched to the energized state ST21 to ST24, regardless of the rotor position in the energized state ST21, when the energized state ST23 is changed to ST24, the rotation direction of the rotor 103 is different when the U phase is disconnected and when a ground short circuit occurs, so it is possible to distinguish between a disconnection and a ground short circuit. In particular, in the case of a ground short circuit in a state of low resistance that is difficult to distinguish by the current value when the faulty phase is connected, the energized state when the normal 1-phase switching element is turned on is closer to the 2-phase energized state, and the encoder output is easy to stabilize in the same state as when the 2-phase is energized, so it is easy to distinguish.

[0211] based on Fig.35 and Fig.36 A flowchart is used to illustrate the power-on process involved in fault phase determination. Fig.35 The processing of S251~S258 and Fig.18 The processing of S201 to S208 in is the same. In S259, the control unit 50 sets the state to the power-on state ST21.

[0212] like Fig.36 As shown, in S260, the control unit 50 determines whether the current state is the power-on state ST21. If it is determined that it is not the power-on state ST21 (S260: No), the process proceeds to S263. If it is determined that it is the power-on state ST21 (S260: Yes), the process proceeds to S261.

[0213] In S261, the control unit 50 determines whether the duration X21 has passed since the start of the power-on state ST21. If it is determined that the duration X21 has passed (S261: Yes), the state is set to the power-on state ST22 and the process proceeds to S265. If it is determined that the duration X21 has not passed (S261: No), the process proceeds to S262.

[0214] In S262, the control unit 50 performs power-on in the power-on state ST21. The power-on state ST11 is power-on of the fault phase. When the U-phase fault flag is turned on, the switch element 411 of the U-phase is turned on. When the V-phase fault flag is turned on, the switch element 412 of the V-phase is turned on. When the W-phase fault flag is turned on, the switch element 413 of the W-phase is turned on.

[0215] In the case where it is determined that the current state is not the power-on state ST21 (S260 is No), the control unit 50 moves to S263 to determine whether the current state is the power-on state ST22. If it is determined that the current state is not the power-on state ST22 (S263 is No), the control unit 50 moves to S266. If it is determined that the current state is the power-on state ST22 (S263 is Yes), the control unit 50 moves to S264.

[0216] In S264, the control unit 50 determines whether the duration X22 has passed since the start of the power-on state ST22. If it is determined that the duration X22 has passed (S264: Yes), the state is set to the power-on state ST23 and the process proceeds to S268. If it is determined that the duration X22 has not passed (S264: No), the process proceeds to S265.

[0217] In S265, the control unit 50 performs power-on in the power-on state ST22. The power-on state ST22 is that the normal phase 1 is powered on, and when the U phase fault flag is turned on, the switch element 412 of the V phase is turned on, when the V phase fault flag is turned on, the switch element 413 of the W phase is turned on, and when the W phase fault flag is turned on, the switch element 411 of the U phase is turned on.

[0218] In the case where it is determined that the current state is not the power-on state ST22 (S263 is No), the control unit 50 moves to S266 to determine whether the current state is the power-on state ST23. If it is determined that the current state is not the power-on state ST23 (S266 is No), the control unit 50 moves to S269. If it is determined that the current state is the power-on state ST23 (S266 is Yes), the control unit 50 moves to S267.

[0219] In S267, the control unit 50 determines whether the duration X23 has passed since the start of the power-on state ST23. If it is determined that the duration X23 has passed (S267: Yes), the state is set to the power-on state ST24 and the process proceeds to S270. If it is determined that the duration X23 has not passed (S267: No), the process proceeds to S268.

[0220] In S268, the control unit 50 performs power-on in the power-on state ST23. The power-on state ST23 is the power-on of the normal phase 1 which is different from the power-on state ST22. When the U-phase fault flag is turned on, the switch element 413 of the W-phase is turned on, when the V-phase fault flag is turned on, the switch element 411 of the U-phase is turned on, and when the W-phase fault flag is turned on, the switch element 412 of the V-phase is turned on.

[0221] In S269, which is transferred to when it is determined that the power-on state ST23 is not in progress (S266 is No), the control unit 50 determines whether the duration X24 has passed since the start of the power-on state ST24. The durations X21 to X24 can be set arbitrarily, and may be at least partially the same or different. When it is determined that the duration X24 has passed (S269 is No), the process moves to S271. When it is determined that the duration X24 has not passed (S269 is Yes), the process moves to S270.

[0222] In S270, the control unit 50 performs power-on in the power-on state ST24. The power-on state ST24 is the same as the power-on state ST22, in which the normal phase 1 is powered on. When the U phase fault flag is turned on, the switch element 412 of the V phase is turned on. When the V phase fault flag is turned on, the switch element 413 of the W phase is turned on. When the W phase fault flag is turned on, the switch element 411 of the U phase is turned on. The processing of S271 and S272 is the same as that of Fig.19 The same is true for S221 and S222.

[0223] If the power-on states ST11 to ST14 are renamed as ST21 to ST24, the fault state determination process and the gear shift process are the same as those in the first embodiment, so the description is omitted. In addition, in the first embodiment, the power-on state ST13 is 2-phase power-on, so the standby time Xw13 in the power-on state ST13 is set to be shorter than the standby time Xw14 in the power-on state ST14, but in the present embodiment, since the power-on states ST23 and ST24 are both 1-phase power-on, it is expected that the standby time Xw23 in the power-on state ST23 and the standby time Xw24 in the power-on state ST24 are set to be equal.

[0224] In this embodiment, the power-on state ST23 in which power is supplied to one phase of the normal phase corresponds to the "first normal phase power-on process", and the power-on state ST24 in which power is supplied to one phase of the normal phase different from the power-on state ST23 corresponds to the "second normal phase power-on process". In addition, the power-on state ST22 corresponds to the "preliminary power-on process". This configuration also has the same effect as the above-mentioned embodiment.

[0225] (Fourth Embodiment)

[0226] The fourth embodiment is as follows Figures 37 to 41 In the above embodiment, ground short circuit and wire break abnormality are distinguished based on the motor rotation angle when the energization mode is switched to the normal phase. In this embodiment, ground short circuit and wire break abnormality are distinguished based on the encoder output when one phase is energized.

[0227] Figures 37 to 40 The left side of the first embodiment Figure 13 to Figure 16 Likewise, the right side portion shows the encoder outputs of the A phase and the B phase. Fig.37 The figure shows a case where the concave portion 105 of the rotor 103 is not opposite to V when the U phase is disconnected and all phases are disconnected. When all phases are disconnected, the attraction force of the motor winding 11 is not generated, so the position of the rotor 103 becomes uncertain. In addition, when the U phase is disconnected, even if the switching element 411 of the U phase is turned on, the motor winding 11 is not energized, so the same state is achieved.

[0228] When the V phase is energized by turning on the V phase switching element 412 from the energized state ST11 to ST12, the convex portion 104 of the rotor 103 faces V. At this time, both the A phase and the B phase face the N pole, and the encoder output becomes Lo.

[0229] When the energized state ST12 is changed to ST13 and the switching elements 412 and 413 of the V and W phases are turned on to energize the VW phases, the convex portion 104 faces the V and W phases. At this time, both the A and B phases face the S pole, and the encoder output becomes Hi.

[0230] When the energized state ST13 changes to ST14 and the V-phase switching element 412 is turned off and the W-phase switching element 413 is turned on to energize the W-phase, the convex portion 104 faces the W pole. At this time, both the A-phase and the B-phase face the N pole, and the encoder output becomes Lo.

[0231] Fig.38 The figure shows a case where the concave portion 105 of the rotor 103 faces V when the U phase is broken and all phases are disconnected. When the concave portion 105 faces V when all phases are disconnected, both the A phase and the B phase face the S pole, and the encoder output becomes Hi.

[0232] When the switching element 412 of the V phase is turned on to energize the V phase by changing from the energized state ST11 to ST12, the coil 112 is energized. When the concave portion 105 is opposite to the V phase, the left and right convex portions 104 are pulled toward the V phase, so the concave portion 105 still maintains a state of being opposite to the V phase. At this time, both the A phase and the B phase are opposite to the S pole, and the encoder output becomes Hi, which is different from the encoder output when the concave portion 105 is not opposite to the V when the power is turned off.

[0233] When the energized state ST12 is changed to ST13 and the switching elements 412 and 413 of the V and W phases are turned on to energize the VW phases, the convex portion 104 faces the V and W phases. At this time, both the A and B phases face the S pole, and the encoder output becomes Hi.

[0234] When the W-phase switching element 413 is turned on from the energized state ST13 to ST14 to conduct W-phase energization, the convex portion 104 faces the W pole. At this time, both the A-phase and the B-phase face the N pole, and the encoder output becomes Lo. That is, by setting the 1-phase energization after the 2-phase energization, regardless of the rotor position when all phases are disconnected, a so-called "1-phase 1-tooth" state is achieved in which the convex portion 104 faces the 1-phase energization, and the encoder output becomes Lo.

[0235] Fig.39 The figure shows a case where the U phase is short-circuited to the ground when all phases are disconnected and the U phase coil 111 is energized so that the convex portion 104 of the rotor 103 faces U. When the convex portion 104 faces U, both the A phase and the B phase face the N pole, and the encoder output becomes Lo.

[0236] When the switching element 412 of the V phase is turned on from the energized state ST11 to ST12, the U phase is short-circuited to the ground and the UV phase is energized, and the convex portion 104 faces the U phase and the V phase. At this time, both the A phase and the B phase face the S pole, and the encoder output becomes Hi. In addition, at this time, the W phase faces the concave portion 105.

[0237] When the state ST12 is changed to ST13 and the switching elements 412 and 413 of the V phase and the W phase are turned on, the W phase is energized, but since the W phase is opposite to the recess 105, the rotor 103 does not rotate, and the A phase and the B phase are opposite to the S pole, maintaining the encoder output Hi state.

[0238] When the W-phase switch element 413 is turned on from the energized state ST13 to ST14, the U-phase is short-circuited to the ground and the WU-phase is energized, and the convex portion 104 faces the U-phase and the W-phase. At this time, both the A-phase and the B-phase face the S pole, and the encoder output becomes Hi.

[0239] Fig.40 The figure shows a case where the U phase is grounded and short-circuited when all phases are disconnected and the U phase coil 111 is energized so that the concave portion 105 of the rotor 103 faces U. When the concave portion 105 faces U, both the A phase and the B phase face the S pole, and the encoder output becomes Hi.

[0240] When the switch element 412 of the V phase is turned on from the energized state ST11 to ST12, the U phase is short-circuited to the ground and becomes the UV phase energized state, and the convex portion 104 faces the U phase and the V phase. At this time, both the A phase and the B phase face the S pole, and the encoder output becomes Hi. Fig.39 Likewise, the description is therefore omitted.

[0241] In the case of a ground short circuit in the U phase, even if the normal phase is energized, since the U phase is also energized, it is also a state of energizing the two phases, and the encoder output is different, so it is possible to distinguish between a wire break and a ground short circuit. In particular, a ground short circuit in a state of low resistance is difficult to distinguish by the current value when the faulty phase is connected, because it is closer to a state of energizing the two phases than an incomplete ground short circuit, and the encoder output is easy to stabilize in the same state as when the two phases are energized, so it is easy to distinguish.

[0242] In addition, Figures 37 to 40 In the description, when switching to 1-phase energization, 2-phase energization, and 1-phase energization when the U-phase fails, the energization state ST22 is set to V-phase energization and the energization state ST24 after 2-phase energization is set to W-phase energization. However, the energized phase in the two 1-phase energizations is arbitrary, for example, in the case of V-phase energization, VW-phase energization, and V-phase energization, the same phase can be energized. In addition, the first 1-phase energization can be omitted and start from 2-phase energization.

[0243] The energization process related to the fault phase identification in this embodiment is the same as that in the first embodiment, and thus the description thereof will be omitted. Fig.41 The process of determining the fault state of this embodiment is described with reference to the flowchart of FIG. Fig. 20 The processing of S501 to S503 in the above is the same. If an affirmative determination is made in S701, the process proceeds to S713.

[0244] If it is determined that the power-on state is not ST11 (S702: No), the processing proceeds to S704 and S705. Fig. 20 The processing of S507 and S508 in is the same. If it is determined in S705 that the waiting time Xw14 has not passed since the power-on state ST14 (S705 is No), the process moves to S706 and the counter Chi is cleared. If it is determined that the waiting time Xw14 has passed (S705 is Yes), the process moves to S707.

[0245] In S707, it is determined whether the encoder outputs of phase A and phase B are both Hi. The state in which the encoder outputs of phase A and phase B are both Hi is a signal mode when the two phases are energized to form a two-phase two-tooth state. When it is determined that at least one of the encoder outputs of phase A and phase B is Lo (S707 is No), the subsequent processing is skipped. When it is determined that the encoder outputs of phase A and phase B are both Hi (S707 is Yes), the process moves to S708 and the counter Chi is incremented.

[0246] In S709, the abnormality determination unit 52 determines whether the counter Chi is greater than the count determination threshold Cth. If it is determined that the counter Chi is less than the count determination threshold Cth (S709 is No), the subsequent processing is skipped. If it is determined that the counter Chi is greater than the count determination threshold Cth (S709 is Yes), the process moves to S710. The processing of S710 to S714 is the same as Fig. 20 The processing of S511 to S515 in the above embodiment is the same as that of the first embodiment. The shift switching processing is the same as that of the first embodiment except for the details of the failure determination.

[0247] The rotation detection unit of this embodiment is the encoder 13, and the abnormality determination unit 52 determines that the fault is always powered on when the encoder signal pattern when energizing one phase in the normal phase is the pattern when energizing two phases. Thus, the fault is always powered on appropriately. In addition, the same effect as the above embodiment is achieved.

[0248] In this embodiment, similarly to the first embodiment, the energization state ST13 in which energization is applied to two normal phases corresponds to the "first normal phase energization process", and the energization state ST14 in which energization is applied to one normal phase corresponds to the "second normal phase energization process".

[0249] (Fifth Embodiment)

[0250] The fifth embodiment is as follows Figures 42 to 48 As described in the above embodiment, when a 1-phase fault occurs, when the switch element of the 1-phase of the normal phase is turned on, if it is a line break fault, it becomes a 1-phase energized state, and if it is a constant energized fault caused by a ground short circuit, it becomes a 2-phase energized state. In the case of 2-phase energization, the convergence of the rotational vibration generated by the switching of the energized phase is better than that of 1-phase energization. Therefore, in this embodiment, the difference in the characteristics of vibration convergence in 1-phase energization and 2-phase energization is used to distinguish whether it is a line break fault or a ground short circuit.

[0251] based on Figure 42 to Figure 44 The behavior of the rotor 103 when the energization mode is switched to the V-phase and W-phase, which are normal phases, when the U-phase fails will be described. Figure 42 to Figure 44 In the example, the horizontal axis is set to time and the vertical axis is set to the motor rotation angle.

[0252] Fig.42 The figure shows that when the U phase is disconnected and in the energized state ST21, the convex portion 104 of the rotor 103 is not facing V. In the energized state ST21, even if the switching element 411 of the U phase, which is the faulty phase, is turned on, the motor winding 11 is not energized, so the rotor 103 does not move.

[0253] When the energized state ST21 changes to ST22, the U-phase switching element 411 is turned off and the V-phase switching element 412 is turned on, the rotor 103 rotates to a position where the convex portion 104 faces V. At this time, since only one phase is energized, the vibration is relatively large even after the waiting time Xw22 has passed.

[0254] When the energized state ST22 is changed to ST23, the V-phase switching element 412 is turned off and the W-phase switching element 413 is turned on, the rotor 103 rotates to a position where the convex portion 104 faces W. At this time, since only one phase is energized, the vibration is relatively large even after the standby time Xw23.

[0255] Fig.43 FIG. 2 shows a case where the convex portion 104 of the rotor 103 faces V in the energized state ST21 when the U phase is disconnected. Fig.42 same.

[0256] From the energized state ST21 to ST22, the switch element 411 of the U phase is turned off and the switch element 412 of the V phase is turned on. In this example, in the energized state ST21, the convex portion 104 is opposite to V, so even if the V phase is energized, the rotor 103 does not move and the rotation angle does not change. In addition, in the case where the concave portion 105 is opposite to V in the energized state ST21, the rotation angle does not change. That is, in the energized state ST21, the rotor position is uncertain, and when the position of the rotor 103 close to the convex portion 104 or the concave portion 105 is opposite to V, the vibration of the rotor 103 is small even if the energization is switched to the V phase.

[0257] The behavior when the power-on state changes from ST22 to ST23 is Fig.42 Similarly, by energizing the W phase, the rotor 103 rotates to a position where the convex portion 104 faces W. At this time, since only one phase is energized, the vibration is relatively large even after the waiting time Xw23 has passed.

[0258] Fig.44 The U-phase is always energized. In the energized state ST21, when the U-phase switching element 411 is turned on, the U-phase coil 111 is energized, and the convex portion 104 faces the U-phase.

[0259] When the energized state ST21 is changed to ST22 and the switching element 411 of the U phase is turned off and the switching element 412 of the V phase is turned on, a two-phase energized state of the U-V phase is achieved, and the rotor 103 rotates to a position where the convex portion 104 faces the U phase and the V phase.

[0260] When the energized state ST22 is changed to ST23 and the switching element 412 of the V phase is turned off and the switching element 413 of the W phase is turned on, a two-phase energized state of W and U phases is achieved, and the rotor 103 rotates to a position where the convex portion 104 faces the U phase and the W phase.

[0261] In the case of a constant power-on fault, the 2-phase power-on state is achieved in the power-on state ST22 and ST23, and the convergence of the vibration is better than that in the case of a line break fault in which the 1-phase power-on state is achieved. Therefore, in this embodiment, the difference between the maximum value and the minimum value after the standby time Xw22 and Xw23 in the power-on state ST22 and ST23 is used to distinguish whether it is a 1-phase line break or a ground short circuit.

[0262] In addition, as in Fig.43 As described in FIG. 1 , depending on the rotor position in the power-on state ST21, there is a case where the rotor 103 does not move even when switching from the power-on state ST21 to ST22 when one phase is disconnected, and an erroneous judgment may occur only based on the switching to the power-on state ST22. Therefore, in this embodiment, judgment is made based on the power-on states ST22 and ST23.

[0263] The power-on process involved in the fault determination of this embodiment is as follows: Fig.45 In addition, since the first half is different from the second embodiment Fig.35 Likewise, therefore in Fig.45 Shown in Fig.36 The corresponding second half. Fig.45 Except for omitting S266, S269, and S270, Fig.36 Similarly, if a negative determination is made in S263, the process proceeds to S267, and if an affirmative determination is made in S267, the process proceeds to S271.

[0264] based on Fig.46 The process of determining the fault state is described in the flowchart of S801. Fig. 20 The processing of S501 is the same. When it is determined that the 2-phase switching before power-on completion flag FlgC is turned on (S801 is yes), it moves to S813. When it is determined that the 2-phase switching before power-on completion flag FlgC is turned off (S801 is no), it moves to S802.

[0265] In S802, the abnormality determination unit 52 determines whether the current state is the power-on state ST21. If it is determined to be the power-on state ST21 (S802: Yes), the process proceeds to S803. The process of S803 is the same as that of Fig. 20 The process of S503 in FIG. 1 is similar to that of S503. If an affirmative determination is made in S803, the process proceeds to S814. If it is determined that the state is not the power-on state ST21 (No in S802), the process proceeds to S804.

[0266] In S804, the abnormality determination unit 52 determines whether the current state is the power-on state ST22. If it is determined not to be the power-on state ST22 (S804: No), the process proceeds to S808. If it is determined to be the power-on state ST22 (S804: Yes), the process proceeds to S805.

[0267] In S805, the abnormality determination unit 52 determines whether the standby time Xw22 has passed since the start of the power-on state ST22. If it is determined that the standby time Xw22 has not passed (S805 is No), the subsequent processing is skipped. If it is determined that the standby time Xw22 has passed (S805 is Yes), the process moves to S806 and performs the maximum value and minimum value update processing in the power-on state ST22.

[0268] The sub-routine for the maximum and minimum value update process in the power-on state ST22 is as follows: Fig.47 In S861, the abnormality determination unit 52 determines whether it is the first operation after the waiting time Xw22 has passed. If it is determined that it is the first operation after the waiting time Xw22 has passed (S861 is yes), the process moves to S862, and the current encoder count value EN is set to the maximum value CTmax22 and the minimum value CTmin22. If it is determined that it is not the first operation after the waiting time Xw22 has passed (S861 is no), the process moves to S863.

[0269] In S863, the abnormality determination unit 52 determines whether the current encoder count value EN is greater than the maximum value CTmax22. When it is determined that the current encoder count value EN is less than the maximum value CTmax22 (S863: No), the value stored as the maximum value CTmax22 is not updated, and the process moves to S865. When it is determined that the current encoder count value EN is greater than the maximum value CTmax22 (S863: Yes), the process moves to S864, and the maximum value CTmax22 is updated as the current encoder count value EN.

[0270] In S865, the abnormality determination unit 52 determines whether the current encoder count value EN is smaller than the minimum value CTmin22. When it is determined that the current encoder count value EN is greater than the minimum value CTmin22 (S865 is No), the value stored as the minimum value CTmin22 is not updated, and the present process is terminated. When it is determined that the current encoder count value EN is smaller than the minimum value CTmin22 (S865 is Yes), the minimum value CTmin22 is updated to the current encoder count value EN.

[0271] Return to Fig.46 In S807, which is followed by the maximum and minimum value update process in the power-on state ST22, the abnormality determination unit 52 determines whether the vibration amplitude A22 (see formula (3)) is greater than the amplitude determination threshold Ath. If it is determined that the vibration amplitude A22 is smaller than the amplitude determination threshold Ath (S807 is No), the subsequent processing is skipped. If it is determined that the vibration amplitude A22 is greater than the amplitude determination threshold Ath (S807 is Yes), the process proceeds to S812.

[0272] A22=CTmax22-CTmin22 · · · (3)

[0273] In the case where it is determined that the current state is not the power-on state ST22 (S804 is No), the abnormality determination unit 52 determines whether the current state is the power-on state ST23 in S808. If it is determined that the current state is not the power-on state ST23 (S808 is No), the subsequent processing is skipped. If it is determined that the current state is the power-on state ST23 (S808 is Yes), the process proceeds to S809.

[0274] In S809, the abnormality determination unit 52 determines whether the standby time Xw23 has passed since the start of the power-on state ST23. If it is determined that the standby time Xw23 has not passed (S809 is No), the subsequent processing is skipped. If it is determined that the standby time Xw23 has passed (S809 is Yes), the process moves to S810 and performs the maximum value and minimum value update processing in the power-on state ST23.

[0275] The sub-routine for the maximum and minimum value update process in the power-on state ST23 is as follows: Fig.48 As shown. In S891, the abnormality determination unit 52 determines whether it is the first calculation after the waiting time Xw23 has passed. If it is determined that it is the first calculation after the waiting time Xw23 has passed (S891 is yes), it moves to S892 and sets the current encoder count value EN to the maximum value CTmax23 and the minimum value CTmin23. If it is determined that it is not the first calculation after the waiting time Xw23 has passed (S891 is no), it moves to S893.

[0276] In S893, the abnormality determination unit 52 determines whether the current encoder count value EN is greater than the maximum value CTmax23. When it is determined that the current encoder count value EN is less than the maximum value CTmax23 (S893: No), the value stored as the maximum value CTmax23 is not updated, and the process moves to S895. When it is determined that the current encoder count value EN is greater than the maximum value CTmax23 (S893: Yes), the process moves to S894, and the maximum value CTmax23 is updated as the current encoder count value EN.

[0277] In S895, the abnormality determination unit 52 determines whether the current encoder count value EN is smaller than the minimum value CTmin23. When it is determined that the current encoder count value EN is greater than the minimum value CTmin23 (No in S895), the value stored as the minimum value CTmin23 is not updated, and the present process is terminated. When it is determined that the current encoder count value EN is smaller than the minimum value CTmin23 (Yes in S895), the minimum value CTmin23 is updated to the current encoder count value EN.

[0278] Return to Fig.46 In S811, which is followed by the maximum and minimum value update process in the power-on state ST23, it is determined whether the vibration amplitude A23 (refer to formula (4)) is greater than the amplitude determination threshold Ath. The amplitude determination threshold Ath is set to be the same as the value used in S807, but it can also be different. In the case where it is determined that the vibration amplitude A23 is smaller than the amplitude determination threshold Ath (S811 is no), the subsequent processing is skipped. In the case where it is determined that the vibration amplitude A23 is greater than the amplitude determination threshold Ath (S811 is yes), it moves to S812.

[0279] A23=CTmax23-CTmin23···(4)

[0280] When it is determined that the vibration amplitudes A22 and A23 are equal to or larger than the amplitude determination threshold value Ath (Yes in S807 or Yes in S811 ), the process proceeds to S812 , where the abnormality determination unit 52 determines that the fault occurring in the faulty phase is a line break fault and turns on a one-phase line break fault flag FlgD.

[0281] In the case where it is determined that the 2-phase switching pre-energization completion flag FlgC is on (S801 is yes), the abnormality determination unit 52 determines whether the 1-phase disconnection fault flag FlgD is off in S813. If it is determined that the 1-phase disconnection fault flag FlgD is on (S813 is no), the subsequent processing is skipped. If it is determined that the 1-phase disconnection fault flag FlgD is off (S813 is yes), it is determined that the abnormality generated in the faulty phase is a constant power-on fault, and the process moves to S814. The processing of S814 to S816 is the same as that of Fig. 20 The processing of S511 to S513 in is the same.

[0282] In this embodiment, the abnormality determination unit 52 determines that the power-on fault is always on when the vibration amplitude A22, A23 of the encoder count value after the standby time from the start of power on is smaller than the amplitude determination threshold value Ath when one of the normal phases is powered on. Thus, the power-on fault can be appropriately determined. In addition, the same effect as the above-mentioned embodiment is achieved.

[0283] In the above embodiment, the encoder 13 corresponds to the "rotation position detection unit", the ECU 40 corresponds to the "motor control device", and the voltage detection circuit 46 corresponds to the "voltage detection unit". The port level corresponds to the "voltage detection value", and the motor current Im corresponds to the "current detection value". In addition, the encoder signal including the A-phase signal and the B-phase signal corresponds to the "rotation position detection value", the encoder count value corresponds to the "rotation position of the motor", and the vibration amplitudes A22 and A23 correspond to the "amplitude of the rotation position".

[0284] (Other Embodiments)

[0285] In the above-mentioned embodiment, the first fault state determination process based on the motor current and the second fault state determination process based on the motor rotation position are performed to determine the always-on fault. In other embodiments, the always-on fault can also be determined by using either the first fault state determination process or the second fault state determination process.

[0286] In the first embodiment and the like, the energization state ST12 as the preliminary energization process is performed before the energization state ST13 as the first normal phase energization process. In other embodiments, the preliminary energization process may be omitted.

[0287] In the above embodiment, the rotation detection unit is an encoder. In other embodiments, for example, a sensor capable of detecting the rotation position other than an encoder such as a resolver may be used. The structure of the current detection unit and the voltage detection unit may also be different from the above embodiment.

[0288] In the above embodiment, the motor is a switched reluctance motor. In other embodiments, the motor may be a component other than a switched reluctance motor, for example, a DC brushless motor, etc. In addition, the number of phases of the motor winding may be 4 or more.

[0289] In the above embodiment, two valleys are provided on the locking plate. In other embodiments, the number of valleys is not limited to two, and for example, four valleys corresponding to the respective gear positions of P, R, N, and D may be formed. In addition, the locking mechanism, the parking lock mechanism, etc. may also be different from the above embodiment.

[0290] In the above-mentioned embodiment, the motor control device is applied to the shift-by-wire system. In other embodiments, the motor control device may be applied to a vehicle-mounted system other than the shift-by-wire system or a non-vehicle motor drive system.

[0291] The present disclosure may also be, for example, "According to the motor control device recorded in item 3 or 4, the drive control unit performs a preliminary energization process of energizing at least one phase or more phases of a normal phase different from the first normal phase energization process before the first normal phase energization process", "According to the motor control device recorded in any one of items 1 to 8, the motor is a three-phase motor, and the drive control unit drives the motor by energizing the motor windings of the normal two phases when it is determined that the faulty phase is one phase and is not the always-energized fault."

[0292] The control unit and method described in the present disclosure can be implemented by a special-purpose computer, which is provided by constituting a processor and a memory programmed in a manner to execute one or more functions embodied by a computer program. Alternatively, the control unit and method described in the present disclosure can also be implemented by a special-purpose computer as follows, which is provided by constituting a processor using one or more special-purpose hardware logic circuits. Alternatively, the control unit and method described in the present disclosure can also be implemented by one or more special-purpose computers consisting of the following combination, which refers to a combination of a processor and a memory programmed in a manner to execute one or more functions and a processor consisting of one or more hardware logic circuits. In addition, the computer program can also be stored as an instruction executed by a computer in a non-temporary tangible storage medium that can be read by a computer. As described above, the present disclosure is not limited by the above-mentioned embodiments in any way, and can be implemented in various forms without departing from its main purpose.

[0293] The present disclosure is described based on the implementation mode. However, the present disclosure is not limited to the implementation mode and structure. The present disclosure also includes various modifications and modifications within the equivalent range. In addition, various combinations and forms, and other combinations and forms in which only one element, more than one element, or less than one element are included, also fall within the scope and scope of the present disclosure.

Claims

1. A motor control device for controlling the drive of a motor (10) having a motor winding (11) of three or more phases, characterized in that: The motor control device comprises: a drive circuit (41) having switch elements (411 to 413) for switching on and off power to each phase of the motor winding; and a control unit (50) comprising a drive control unit (55) for controlling the on / off operation of the switching element and an abnormality determination unit (52) for determining an abnormality of a current supply path for supplying electricity to the motor winding, The control unit is capable of obtaining a detection value of a voltage detection unit (46) for detecting the voltage of each phase of the motor winding, namely a voltage detection value, a detection value of a current detection unit (45) for detecting the current supplied to the motor winding, namely a current detection value, and a detection value of a rotation detection unit (13) for detecting the rotation position of the motor, namely a rotation position detection value. The abnormality determination unit determines a faulty phase based on the voltage detection value when the switching elements of all phases are turned off. The abnormality determination unit determines that the faulty phase is always energized based on at least one of the current detection value when the switching element of the determined faulty phase is turned on and the rotational position detection value when the switching elements of one or more normal phases are turned on.

2. The motor control device according to claim 1, characterized in that: The abnormality determination unit determines that the fault is the always-on fault when the current detection value when the switching element of the faulty phase is turned on is equal to or greater than a current determination threshold.

3. The motor control device according to claim 1 or 2, characterized in that: The abnormality determination unit determines the always-power-on fault based on the change in the rotational position of the motor when a first normal phase power-on process is performed and when a second normal phase power-on process is performed, wherein the first normal phase power-on process is a process of powering one or more phases of a normal phase, and the second normal phase power-on process is a process of powering one or more phases of a normal phase that is different in at least one phase from the first normal phase power-on process.

4. The motor control device according to claim 3, characterized in that: The abnormality determination unit determines that the fault is the always-on fault when the rotation direction when switching from the first normal phase energization process to the second normal phase energization process is different from when all phases are normal.

5. The motor control device according to claim 3, characterized in that: The drive control unit performs a preliminary energization process of energizing one or more normal phases that are different in at least one phase from the first normal phase energization process before performing the first normal phase energization process.

6. The motor control device according to claim 3, characterized in that: When the switching elements of all the normal phases are turned on as the second normal phase energization process, the abnormality determination unit determines that the motor is the always-energized fault if the amount of change in the rotational position of the motor is smaller than a determination threshold.

7. The motor control device according to claim 1 or 2, characterized in that: The abnormality determination unit determines that the fault is the always-on fault when power is supplied to one of the normal phases and the amplitude of the rotation position of the motor after a waiting time has elapsed from the start of power supply is smaller than an amplitude determination threshold.

8. The motor control device according to claim 1 or 2, characterized in that: The rotation detection unit is an encoder, The abnormality determination unit determines that the fault is the always-on fault when the encoder signal pattern when energizing one of the normal phases is the same as the pattern when energizing two phases.

9. The motor control device according to claim 1, characterized in that: The motor is a 3-phase motor. The drive control unit drives the motor by energizing the motor windings of two normal phases when it is determined that the faulty phase is one phase and the fault is not the always-on fault.

10. The motor control device according to claim 9, characterized in that: When all phases are normal and a stagnation abnormality occurs in which the rotation position detection value is stagnant, the drive control unit performs open circuit driving for switching the energized phase without using the rotation position detection value instead of feedback control based on the rotation position detection value. The drive control unit drives the motor by energizing the normal two-phase motor windings through the feedback control when the faulty phase is one phase and it is not the always-on fault, and stops the drive control of the motor when the stagnation abnormality occurs.

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