JP6610427B2 - Motor control device - Google Patents

Description

  The present invention relates to a control device that controls a motor driven by a three-phase alternating current.

  As a control device for detecting an abnormality in a motor coil, a motor control device disclosed in Patent Document 1 is known. The motor control device of Patent Document 1 includes a phase loss determination command output unit, a phase loss detection angle correction unit, a current supply unit, and a phase loss determination unit. The phase loss determination command output unit outputs a d-axis current value and a q-axis current value used when detecting an abnormality in the coil. The phase loss detection angle correction unit detects the electrical angle of the motor, and there is a phase coil in which the current value to be energized is 0 when energization is performed with the q-axis current value being 0 at the detected electrical angle. In the case of an angle, an electrical angle obtained by correcting the detected electrical angle with a predetermined correction angle is selected. In addition, the phase loss detection angle correction unit selects the detected electrical angle when the current value to be energized is not an angle at which there is a phase coil. The energization unit energizes each coil of the motor based on the d-axis current value and the q-axis current value output by the phase loss determination command output unit and the electrical angle selected by the phase loss detection angle correction unit. The phase loss determination unit determines whether or not an abnormality has occurred in any of the coils included in the motor, based on the current flowing through each coil when the energization unit energizes the motor.

JP 2014-121144 A

  However, in the motor control device of Patent Document 1, current may not flow in the phase of the motor depending on the angle of the motor. At this time, it is necessary to rotate the motor until current flows in the phase of the motor. Therefore, in spite of the process of detecting an abnormality of the motor, the motor may rotate and the user may feel uncomfortable.

  This invention is made | formed in view of such a condition, and it aims at suppressing rotation of the motor at the time of detecting failure of a motor.

  The motor control device of the present invention is a motor that is driven by a three-phase alternating current, and that controls the motor including the three electric wires through which the three-phase alternating current flows. A q-axis current is determined for each of a plurality of current patterns of a target current that is a current to be flowed, and a diagnostic q whose polarity is reversed at a predetermined timing with the smallest value among the determined absolute values of the q-axis currents being an absolute value Based on the q-axis current determining means for determining the axis current, the diagnostic q-axis current, and the diagnostic d-axis current corresponding to the diagnostic q-axis current, the current is output to the electric wire. Output current control means for performing control, and failure detection means for detecting a failure of the motor based on an actual current that has flowed through the electric wire.

  According to the motor control device of the present invention, it is possible to suppress the rotation of the motor when detecting a motor failure.

It is a block diagram of a motor control system. It is a figure which shows a 1st electric current pattern graph. It is a figure which shows a 2nd electric current pattern graph. It is a figure which shows a 3rd electric current pattern graph. It is a flowchart of the current control process of 1st Embodiment. It is a flowchart of a failure diagnosis process. It is a figure of a 1st electric current graph. It is a figure of a 2nd electric current graph and a failure counter. It is a flowchart of the current control process of 2nd Embodiment.

<First Embodiment>
[Configuration of motor control system]
First, a motor control system 1 according to the present embodiment will be described with reference to FIG.
The motor control system 1 is a system that controls the motor 20 driven by a three-phase alternating current, and includes a normal mode and a failure diagnosis mode as operation modes. In the normal mode, for example, the motor 20 is controlled by vector control so that the motor 20 outputs a predetermined driving force or rotates at a predetermined rotation speed. In the failure diagnosis mode, the failure of the motor 20 is diagnosed by detecting whether or not the electric wire 21 included in the motor 20 is disconnected.

The motor control system 1 includes a motor control device 100, a power supply device 10, an inverter 11, a current sensor 12, a motor angle sensor 13, and a motor 20.
The motor control device 100 controls the entire motor control system 1 and controls the motor 20 according to the operation mode. When the motor control system 1 is in the normal mode, the motor control device 100 performs vector control based on currents flowing through the phases of the motor 20 to control the driving force and the rotational speed of the motor 20. When performing the vector control, the motor control device 100 calculates, for example, a q-axis current and a d-axis current corresponding to a phase current flowing in each phase of the motor 20, and uses the q-axis current and the d-axis current to calculate the motor. Control is performed so that a predetermined three-phase alternating current flows through 20.

When the motor control system 1 is in the failure diagnosis mode, the motor control device 100 performs control to flow a current having a constant current value to the motor 20 as will be described in detail later. And based on the electric current which actually flows into the motor 20, it is detected whether the electric wire 21 with which the motor 20 is provided is disconnected, and a failure is diagnosed.
In the present embodiment, when the motor control device 100 is activated, the failure diagnosis mode is entered to diagnose the failure. When no failure is detected, the motor 20 is controlled by shifting to the normal mode after the failure diagnosis mode.
The motor control device 100 is a computer including a CPU and storage means. Examples of the storage means include a ROM, a RAM, and a hard disk drive. When the CPU executes the program stored in the storage unit, each function described below included in the motor control device 100 is realized.

The power supply device 10 is a device that supplies power to each unit included in the motor control system 1.
Inverter 11 passes a current through motor 20 based on an instruction from motor control device 100. The inverter 11 allows a three-phase alternating current to flow through the electric wire 21 in the normal mode, and allows a current having a constant current value to flow in the failure diagnosis mode.
The current sensor 12 detects the current value of the current flowing through the electric wire 21 included in the motor 20. Since there are three electric wires 21, that is, electric wires 21 </ b> A, B, and C, the current sensor 12 has three current sensors 12 </ b> A, B, and C so as to correspond to each of the electric wires 21. Detect value. The current sensor 12 outputs the detected current value to the motor control device 100.
The motor angle sensor 13 detects the rotation angle from the reference position of the rotor included in the motor 20 and outputs it to the motor control device 100. Hereinafter, the rotation angle from the reference position of the rotor included in the motor 20 is also referred to as a motor angle.

  The motor 20 includes a plurality of electric wires 21 that are driven by a three-phase alternating current and through which the three-phase alternating current flows. The electric wire 21 is connected to the inverter 11. In the present embodiment, as described above, there are three electric wires 21, that is, electric wires 21 </ b> A, B, and C. A three-phase alternating current is supplied to the motor 20 when the motor control system 1 is in the normal mode. In the failure diagnosis mode, a constant current value is supplied to the motor 20 and the motor 20 rotates. It is suppressed. When a three-phase alternating current is passed through the motor 20, currents in the U-phase, V-phase, and W-phase are assumed to flow through the wires 21A, B, and C, respectively.

[Outline of failure diagnosis mode processing]
Next, an outline of processing performed in the failure diagnosis mode will be described.
The motor control device 100 detects the disconnection of the electric wires 21A, B, and C by performing a control that causes a current having a constant current value to flow through the electric wires 21A, B, and C in the failure diagnosis mode. A current having a constant current value is called a target current. There are a plurality of current patterns which are patterns of the target current. Here, an example in which there are three current patterns, ie, first to third current patterns, will be described.
The first current pattern is a current pattern in which the target currents of the electric wires 21A, B, and C are 18.5 [A], 18.5 [A], and 37 [A], respectively.
The second current pattern is a current pattern in which the target current magnitudes of the electric wires 21A, B, and C are 18.5 [A], 37 [A], and 18.5 [A], respectively.
The third current pattern is a current pattern in which the target currents of the electric wires 21A, B, and C are 37 [A], 18.5 [A], and 18.5 [A], respectively.

The motor control device 100 performs the failure diagnosis mode process using the first to third current patterns as follows.
First, as the first process, the motor control device 100 assumes that the q-axis currents corresponding to the respective current patterns and the currents when the target currents of the first to third current patterns are passed through the electric wires 21A, 21B, and 21C. Determine the d-axis current. Since there are three types of current patterns, three q-axis currents and three d-axis currents are obtained.

It is known that the q-axis current is a value that contributes to the torque of the motor 20, and the torque of the motor 20 is smaller as the absolute value of the q-axis current is smaller.
Therefore, the motor control device 100 determines the q-axis current having the smallest absolute value among the calculated three q-axis currents as the diagnostic q-axis current. Further, a d-axis current that causes a current pattern current corresponding to the diagnostic q-axis current to flow is determined as the diagnostic d-axis current.
The diagnostic q-axis current is a value that becomes the target current of the electric wires 21A, B, and C together with the diagnostic d-axis current, and the electric wires 21A, B are obtained from the diagnostic q-axis current and the diagnostic d-axis current. , C target current can be calculated.

Next, as the second process, the motor control device 100 performs control so that the target current corresponding to the diagnostic q-axis current and the diagnostic d-axis current flows through the electric wire 21.
Next, as a third process, the motor control device 100 detects the disconnection state of the electric wires 21A, B, and C by detecting the actual current that actually flows through the electric wires 21A, B, and C.
Such first to third processes are repeated to increase the accuracy of detecting the disconnection of the electric wires 21A, B, and C.
However, in the second process, the motor 20 may rotate because control is performed to flow the diagnostic q-axis current and the current corresponding to the diagnostic q-axis current to the motor 20. Therefore, in the first process, the diagnostic q-axis current is determined so that the polarity (positive / negative) is reversed every time. Thus, in the second process, even if the motor 20 rotates, the rotation direction of the motor 20 is reversed every time, so that the rotor angle of the motor 20 is kept substantially constant.

[Current pattern]
Next, details of the current pattern will be described. In the present embodiment, the first to third current patterns have a first type and a second type, respectively. In the first type and the second type, the absolute values of the target currents of the electric wires 21A, 21B, and 21C are the same, but the polarity (positive / negative) is reversed. Therefore, each time the first process is performed, the first type and the second type of each current pattern are alternately switched to determine the diagnostic q-axis current and the diagnostic q-axis current, thereby obtaining the first Each time processing is performed, the sign of the diagnostic q-axis current is reversed.

Next, specific examples of current patterns will be described with reference to FIGS. 2A to 2C.
First, the first current pattern will be described with reference to FIG. 2A. FIG. 2A is a diagram illustrating a first current pattern graph.
In the first type of the first current pattern, the target currents of the electric wires 21A, B, and C are 18.5 [A], 18.5 [A], and -37 [A], respectively. In the second type of the first current pattern, the target currents of the electric wires 21A, B, and C are -18.5 [A], -18.5 [A], and 37 [A], respectively.
As described above, the first type and the second type have the same absolute value of the target current, but the polarity is inverted. This also applies to the second and third current patterns described below.

Next, the relationship between the first type or second type target current of the first current pattern and the q-axis current and d-axis current will be described.
As already known, the d-axis current can be derived from the currents of the electric wires 21A, B, and C by the following formula (1). Further, the q-axis current can be derived from the currents of the electric wires 21A, B, and C by the following formula (2). In the formula, Iq and Id are q-axis current and d-axis current, respectively. In the formula, Iu, Iv, and Iw are currents of the electric wires 21A, B, and C, respectively, and correspond to U-phase, V-phase, and W-phase currents, respectively. Θ in the equation is a motor angle.

As described above, the d-axis current and the q-axis current depend on the motor angle θ. Therefore, the d-axis current and the q-axis current such that the target currents of the electric wires 21A, B, and C are the first type and the second type of the first current pattern depend on the motor angle θ. This is illustrated in the first current pattern graph shown in FIG. 2A.
The horizontal axis of the first current pattern graph is the motor angle θ. The vertical axis of the first current pattern graph is the current value of the d-axis current and the q-axis current.
Line L11 is a d-axis current such that the target current is the first type of the first current pattern. Line L12 is a q-axis current such that the target current is the first type of the first current pattern.
Line L13 is a d-axis current such that the target current is the second type of the first current pattern. Line L14 is a q-axis current such that the target current is the second type of the first current pattern.

  As can be seen from the first current pattern graph of FIG. 2A, when the motor angle is the same, the first type q-axis current and the second type q-axis current have the same absolute value and the opposite polarities. Similarly, when the motor angle is the same, the first type d-axis current and the second type d-axis current have the same absolute value and the opposite polarities. This also applies to the second and third current patterns described below.

Next, how to obtain the q-axis current and the d-axis current so that the target current is the first type or the second type of the first current pattern will be described.
As a first method, the currents Iu, Iv, and Iw that are target currents of the first type or the second type of the first current pattern are substituted into the formulas (1) and (2), and the formulas (1) and (2) The motor angle θ is substituted into (2). Thereby, the q-axis current Iq and the d-axis current Id can be calculated such that the target current is the first type or the second type of the first current pattern.

As a second method, the calculation results of the lines L11 to L14 of the first current pattern graph are stored in the storage unit of the motor control device 100 in advance. For example, when determining the q-axis current and the d-axis current so that the target current is the first type of the first current pattern, the motor control device 100 refers to the calculation results for the lines L11 and L12 corresponding to the motor angle θ. To do. Thereby, the q-axis current Iq and the d-axis current Id that can be the first type of the first current pattern can be obtained. The q-axis current Iq and the d-axis current Id that become the second type of the first current pattern can be obtained in the same manner.
The method of obtaining the q-axis current and the d-axis current so that the target current is the first type or the second type of the second current pattern or the third current pattern is the same as in the case of the first current pattern.

Next, the second current pattern will be described with reference to FIG. 2B. FIG. 2B is a diagram illustrating a second current pattern graph.
In the first type of the second current pattern, the target currents of the electric wires 21A, B, and C are 18.5 [A], −37 [A], and 18.5 [A], respectively. In the second type of the second current pattern, the target currents of the electric wires 21A, B, and C are −18.5 [A], 37 [A], and −18.5 [A], respectively.

Next, the relationship between the first type or second type target current of the second current pattern and the q-axis current and the d-axis current will be described.
Using the above equations (1) and (2), the q-axis current and the d-axis current such that the target current is the first type and the second type of the second current pattern are shown in FIG. It is an electric current pattern graph. In the second current pattern graph, similarly to the first current pattern graph of FIG. 2A, the q-axis current and the d-axis current depend on the motor angle θ. The vertical axis and the horizontal axis of the second current pattern graph are the same as those of the first current pattern graph.
Line L21 is a d-axis current such that the target current is the first type of the second current pattern. Line L22 is a q-axis current such that the target current is the first type of the second current pattern.
Line L23 is a d-axis current such that the target current is the second type of the second current pattern. Line L24 is a q-axis current such that the target current is the second type of the second current pattern.

Next, the third current pattern will be described with reference to FIG. 2C. FIG. 2C is a diagram showing a third current pattern graph.
In the first type of the third current pattern, the target currents of the electric wires 21A, B, and C are −37 [A], 18.5 [A], and 18.5 [A], respectively. In the second type of the third current pattern, the target currents of the electric wires 21A, B, and C are 37 [A], −18.5 [A], and −18.5 [A], respectively.

Next, the relationship between the first type or second type target current of the third current pattern and the q-axis current and the d-axis current will be described.
Using the above equations (1) and (2), the q-axis current and the d-axis current such that the target current is the first type and the second type of the third current pattern are shown in FIG. It is an electric current pattern graph. In the third current pattern graph, similarly to the first current pattern graph of FIG. 2A, the q-axis current and the d-axis current depend on the motor angle θ. The vertical axis and the horizontal axis of the third current pattern graph are the same as those of the first current pattern graph.
Line L31 is a d-axis current such that the target current is the first type of the third current pattern. Line L32 is a q-axis current such that the target current is the first type of the third current pattern.
Line L33 is a d-axis current such that the target current is the second type of the third current pattern. Line L34 is a q-axis current such that the target current is the second type of the third current pattern.

Next, how to determine the target current will be described. The target current is determined so as to satisfy the following conditions.
The first condition is that the target current is a current value that can reliably detect disconnection of the electric wire 21 even if an error in the electric current flowing through the electric wire 21 or noise occurs in the electric current. The first example of current error is output control error, which is the difference between the current controlled by the motor control device 100 to flow through the electric wire 21 and the current that actually flows when the electric wire 21 is not disconnected. is there. The second example of the current error is an error of the current sensor 12, which is the difference between the current detected by the current sensor 12 and the current that actually flows.
The second condition is that the target current can be realized in terms of the configuration of the motor 20 and the circuit of the motor control device 100. In the present embodiment, the motor 20 is driven by a three-phase alternating current, and the motor control device 100 is a device that controls the driving of the motor 20. Therefore, it is necessary to determine the target current so that the total value of the electric currents of the electric wires 21A, B, and C becomes zero.
The third condition is to make the absolute value of the target current as small as possible within a range that satisfies the first condition and the second condition. Thereby, the torque of the motor 20 can be suppressed.

In the example of this embodiment, in order to satisfy the first condition, the magnitude of the target current needs to be 18.5 [A] or more. In order to satisfy the second and third conditions, for example, when two of the target currents of the electric wires 21A, 21B, and 21C are set to 18.5 [A], the other target current is −37 [A ] Is required.
Based on such a concept, the target currents of the first to third current patterns are determined.

[Function configuration]
Next, with reference to FIG. 1, the structure of the function with which the motor control apparatus 100 is provided is demonstrated.
The motor control device 100 includes a failure diagnosis unit 110, a dq-axis current calculation unit 120, a phase current calculation unit 130, an angle detection unit 140, and a current detection unit 150.
The failure diagnosis unit 110 controls the operation of the motor control system 1 in the failure diagnosis mode and diagnoses the failure of the motor 20. The failure diagnosis unit 110 includes a current control unit 111 and a failure detection unit 115.
The current control unit 111 controls the current that flows through the motor 20 in the failure diagnosis mode. The current control unit 111 includes a q-axis current determination unit 112, a d-axis current determination unit 113, and an output current control unit 114.

The q-axis current determination unit 112 determines the already described diagnostic q-axis current. In this determination, the q-axis current determination unit 112 obtains a q-axis current such that the target current of each current pattern flows through the electric wires 21A, B, and C for each of the first to third current patterns. The diagnostic q-axis current is determined based on the obtained q-axis current. The absolute value of the diagnostic q-axis current is the smallest value among the obtained absolute values of the q-axis current, and the diagnostic q-axis current is set so that the polarity of the diagnostic q-axis current is reversed at a predetermined timing. decide. The predetermined timing is, for example, a timing for each time obtained by adding up a transition period and a steady period described later.
The d-axis current determining unit 113 determines the d-axis current that causes the target current of the current pattern corresponding to the diagnostic q-axis current to flow as the already described diagnostic d-axis current.
The output current control unit 114 performs control to output a current to the electric wire 21 based on the diagnostic q-axis current and the diagnostic d-axis current. The output current control unit 114 determines the q-axis current and the d-axis current based on the diagnostic q-axis current and the diagnostic d-axis current, and outputs them to the dq-axis current calculation unit 120. Control is performed to output currents derived from the axial current and the d-axis current to the electric wires 21A, B, and C. Thus, the current that the output current control unit 114 controls to output to the electric wires 21A, B, and C via the dq axis current calculation unit 120 and the inverter 11 is referred to as an output current. As will be described later, the output current matches the target current in the steady period, but the output current varies so as to approach the target current in the transient period.
The failure detection unit 115 detects the failure of the motor 20 by detecting the disconnection of the wire 21 as a failure of the wire 21 based on the actual current of the wire 21 acquired from the current detection unit 150.

  The dq-axis current calculation unit 120 calculates the d-axis current and the q-axis current by vector control using the current flowing in each phase of the motor 20 detected by the current sensor 12 in the normal mode. The data is sent to the calculation unit 130. The dq-axis current calculation unit 120 outputs the q-axis current and the d-axis current input from the output current control unit 114 to the phase current calculation unit 130 without conversion in the failure diagnosis mode.

  The phase current calculation unit 130 calculates the current that flows through each of the electric wires 21A, B, and C from the d-axis current and the q-axis current input from the dq-axis current calculation unit 120, and outputs the calculation result to the inverter 11. . In the normal mode, the inverter 11 is instructed so that a three-phase alternating current flows through the electric wires 21A, B, and C. In the failure diagnosis mode, the inverter 11 is instructed so that the DC current calculated from the d-axis current and the q-axis current input from the dq-axis current calculation unit 120 flows through the electric wires 21A, B, and C.

The angle detection unit 140 converts the output of the motor angle sensor 13 into a format that can be handled by the motor control device 100, and outputs the converted motor angle to the current control unit 111 and the dq-axis current calculation unit 120. Thus, the motor angle is detected in the motor control device 100.
The current detection unit 150 converts the outputs of the current sensors 12A, B, and C into a format that can be handled by the motor control device 100, and converts the current flowing in the converted electric wires 21A, B, and C to the failure detection unit 115 and the phase current calculation unit 130. Output to. Thus, the actual current is detected in the motor control device 100.

[Current control processing]
Next, details of processing performed in the failure diagnosis mode will be described. The failure diagnosis mode processing includes current control processing and failure diagnosis processing. The current control process and the failure diagnosis process are executed alternately every predetermined time or every predetermined process, for example.
First, the current control process will be described with reference to FIG. FIG. 3 is a flowchart of the current control process.
In step S100, the current control unit 111 determines whether or not the operation mode of the motor control system 1 is a failure diagnosis mode. The current control unit 111 can determine the operation mode of the motor control system 1 by referring to, for example, a predetermined flag of a storage unit included in the motor control device 100. The current control unit 111 proceeds to step S101 when the operation mode is the failure diagnosis mode, and executes step S100 again when the operation mode is not the failure diagnosis mode.

In step S <b> 101, the angle detection unit 140 outputs a motor angle based on the output of the motor angle sensor 13 to the current control unit 111.
In step S <b> 102, the current control unit 111 determines whether or not the q-axis current determination unit 112 has previously determined a diagnostic q-axis current that causes the first type target current to flow through the electric wire 21. The current control unit 111 advances the process to step S <b> 106 when the q-axis current determination unit 112 has previously determined a diagnostic q-axis current such that the first type target current flows through the electric wire 21. When the q-axis current determining unit 112 has previously determined a diagnostic q-axis current such that the second type target current flows through the electric wire 21, the process proceeds to step S103.

In step S103, the q-axis current determination unit 112 calculates the q-axis current Iqf1 such that the first type target current of the first current pattern flows. In addition, the d-axis current determination unit calculates a d-axis current Idf1 such that the first type target current of the first current pattern flows.
In step S104, the q-axis current determination unit 112 calculates the q-axis current Iqf2 such that the first type target current of the second current pattern flows. In addition, the d-axis current determination unit calculates a d-axis current Idf2 such that the first type target current of the second current pattern flows.
In step S105, the q-axis current determination unit 112 calculates the q-axis current Iqf3 such that the first type target current of the third current pattern flows. Further, the d-axis current determination unit calculates a d-axis current Idf3 such that the first type target current of the third current pattern flows.
Note that the processing of steps S103 to S105 may be executed in a different order.

In step S106, the q-axis current determination unit 112 calculates the q-axis current Iqf1 such that the second type target current of the first current pattern flows. Further, the d-axis current determination unit calculates a d-axis current Idf1 such that the second type target current of the first current pattern flows.
In step S107, the q-axis current determination unit 112 calculates a q-axis current Iqf2 such that the second type target current of the second current pattern flows. In addition, the d-axis current determination unit calculates a d-axis current Idf2 such that the second type target current of the second current pattern flows.
In step S108, the q-axis current determination unit 112 calculates a q-axis current Iqf3 such that the second type target current of the third current pattern flows. In addition, the d-axis current determination unit calculates a d-axis current Idf3 such that the second type target current of the third current pattern flows.
Note that the processing of steps S106 to S108 may be executed in a different order.
In the processing from step S103 to S108, the motor angle obtained in step S101 is used.

In step S109, the q-axis current determining unit 112 determines the q-axis current Iqf1 to Iqf3 having the smallest absolute value as the diagnostic q-axis current. When the q-axis currents Iqf1 to Iqf3 are calculated in steps S103 to S105, the diagnostic q-axis current determined in step S109 is used for diagnosis such that the first type target current flows through the electric wire 21. q-axis current. Further, when the q-axis currents Iqf1 to Iqf3 are calculated in steps S106 to S108, the diagnostic q-axis current determined in step S109 is used for diagnosis such that the second type target current flows through the electric wire 21. q-axis current.
In step S110, the d-axis current determination unit 113 sets the d-axis current of the current pattern corresponding to the diagnostic q-axis current among the d-axis currents Idf1 to Idf3 calculated in steps S103 to S105 as the diagnostic d-axis current. decide. That is, when the diagnostic q-axis current is the q-axis current Iqf1, the diagnostic d-axis current is the d-axis current Idf1. When the diagnostic q-axis current is the q-axis current Iqf2, the diagnostic d-axis current is the d-axis current Idf2. When the diagnostic q-axis current is the q-axis current Iqf3, the diagnostic d-axis current is the d-axis current Idf3.

In step S <b> 111, the output current control unit 114 controls the output current that is the current output to the electric wire 21 based on the diagnostic q-axis current and the diagnostic d-axis current.
At this time, the output current control unit 114 performs control so that the output current gradually approaches the target current at a predetermined change rate within a predetermined transient period B [seconds]. Then, after the transition period B has elapsed, the output current is matched with the target current for a predetermined steady period C [seconds].
The transient period B is a predetermined period including a period in which the output current approaches the target current of the current pattern corresponding to the diagnostic q-axis current. The steady period C is a predetermined period in which the output current is maintained at the target current of the current pattern corresponding to the diagnostic q-axis current after the transition period has elapsed.

Here, the q-axis current and the d-axis current corresponding to the output current are referred to as an output q-axis current and an output d-axis current, respectively.
The output current control unit 114 changes the output q-axis current and the output d-axis current at a predetermined change rate so as to approach the diagnostic q-axis current and the diagnostic d-axis current within the transition period B [seconds]. The output q-axis current and the output d-axis current are output to the dq-axis current calculation unit. Then, after the transition period B has elapsed, during the steady period C, output d-axis current and output d-axis current equal to the diagnostic q-axis current and the diagnostic d-axis current are output to the dq-axis current calculation unit.
As a result, the output current can be controlled as described above.
And after completion | finish of the process of step S111, the output current control part 114 returns a process to step S100.

Next, with reference to FIG. 5A, an example of output current by current control processing will be described. FIG. 5A is a diagram illustrating a first current graph.
The horizontal axis of the first current graph is time, and the vertical axis is the current value of the electric wire 21A. A line L41 indicates a change over time of the target current of the electric wire 21A. A line L42 indicates a time change of the output current of the electric wire 21A. The line L43 will be described later.

As described above, the target current of the electric wire 21 is a current calculated from the diagnostic q-axis current and the diagnostic d-axis current, and the polarity is reversed in a cycle of “transient period B + steady period C”. This is because the diagnostic q-axis current determined in step S109 is inverted in polarity every time it is determined in step S109. The sign of the diagnostic q-axis current is inverted because of the diagnosis q-axis current flowing through the first type target current and the second type target current flowing at each determination in step S109. This is because the q-axis current is calculated alternately.
The output current is controlled so as to approach the target current at a predetermined change rate during the transition period B by the control in step S111. Further, after the transition period B elapses, during the steady period C, the output current is controlled to match the target current.
In the diagnostic current Iu graph shown in FIG. 5A, the target current repeats 18.5 [A] and −18.5 [A] in a cycle of “transient period B + steady period C”.

[Failure diagnosis processing]
Next, failure diagnosis processing will be described with reference to FIG. FIG. 4 is a flowchart of the failure diagnosis process.
In step S200, the failure detection unit 115 determines whether or not the motor control device 100 is turned on and an instruction to start the motor control device 100 has been issued. The failure detection unit 115 advances the process to step S201 when the power of the motor control device 100 is turned on, and executes the process of step S200 again when the power of the motor control device 100 is not turned on. Note that, even when the power is off, the motor control device 100 is operating in a state where power consumption is limited, for example, and can perform the process of step S200.
In step S201, the failure detection unit 115 initializes the failure counter to zero. The failure counter is a counter provided for each of the electric wires 21A, B, and C, and is prepared, for example, in a predetermined area of a storage unit provided in the motor control device 100.

In step S202, the failure detection unit 115 sets a predetermined flag of a storage unit included in the motor control device 100, for example, and sets the operation mode of the motor control system 1 to the failure diagnosis mode.
In step S <b> 203, the failure detection unit 115 determines whether or not the output current control unit 114 performs control to flow a target current corresponding to the diagnostic q-axis current and the diagnostic d-axis current. That is, the failure detection unit 115 determines whether or not the transition period B shown in FIG. The failure detection unit 115 makes this determination by inquiring of the output current control unit 114 or the like. The failure detection unit 115 advances the process to step S204 when the control of flowing the target current corresponding to the diagnostic q-axis current and the diagnostic d-axis current is performed, and advances the process to step S213 when it is not performed.

In step S204, the failure detection unit 115 detects the actual currents of the electric wires 21A, B, and C based on the output of the current detection unit 150 until the steady period C ends at the maximum.
In step S205, the failure detection unit 115 determines whether or not the electric wire 21A is in the failure count state from the detection result in step S204. The failure count state is a state in which the state where the absolute value of the actual current flowing through the electric wire 21 detected in step S204 is equal to or less than a predetermined failure determination current value continues for a predetermined determination period D [seconds]. The determination period D is a period equal to or less than the steady period C. It is assumed that the failure determination current value and the determination period D are stored in advance in the storage unit of the motor control device 100, for example.
The failure detection unit 115 proceeds to step S206 when the electric wire 21A is in the failure count state, and proceeds to step S207 when the electric wire 21A is not in the failure count state.
In step S206, the failure detection unit 115 increments the failure counter of the electric wire 21A.

In step S207, the failure detection unit 115 determines whether or not the electric wire 21B is in the failure count state from the detection result in step S204. The failure detection unit 115 advances the process to step S208 when the electric wire 21B is in the failure count state, and advances the process to step S209 when the electric wire 21B is not in the failure count state.
In step S208, the failure detection unit 115 increments the failure counter of the electric wire 21B.

In step S209, the failure detection unit 115 determines whether or not the electric wire 21C is in the failure count state from the detection result in step S204. The failure detection unit 115 advances the process to step S210 when the electric wire 21C is in the failure count state, and advances the process to step S211 when the electric wire 21C is not in the failure count state.
In step S210, the failure detection unit 115 increments the failure counter of the electric wire 21C.

In step S211, the failure detection unit 115 determines whether any of the failure counters of the electric wires 21A, B, and C is equal to or greater than a predetermined failure threshold. The failure threshold is assumed to be stored in advance in the storage unit of the motor control device 100, for example. The failure detection unit 115 advances the process to step S212 when there is at least one failure counter greater than or equal to the failure threshold, and advances the process to step S213 when there is no failure counter greater than or equal to the failure threshold.
When the failure counter exceeds the failure threshold, the failure detection unit 115 determines that the wire 21 corresponding to the failure counter that has exceeded the failure threshold has broken.

In step S212, the failure detection unit 115 determines that the motor 20 is disconnected and a failure has occurred, and notifies that fact.
Examples of notification destinations include a device that uses the motor control system 1 as a subsystem or a control unit of the system, a monitoring device of the motor control system 1, and a user who uses the motor control system 1. It is not limited.
As an example of the notification method, when the notification destination is an apparatus or a system, notification by a wired or wireless signal can be given. For example, when the notification destination is a user, a predetermined output is performed on an output device (not shown) included in the motor control system 1.
The notification content may be only that the disconnection has occurred in the motor 20 or may include whether the electric wire 21 that has been determined to have been disconnected is the electric wire 21A, B, or C.

In step S213, the failure detection unit 115 determines whether or not a predetermined diagnosis period Y [second] has elapsed since the failure diagnosis mode was entered. The diagnosis period Y is stored in advance in the storage unit of the motor control device 100, for example. The failure detection unit 115 advances the process to step S214 when the diagnosis period Y has elapsed, and returns the process to step S203 when it has not elapsed.
In step S214, the failure detection unit 115 determines that the motor 20 is not disconnected and a failure has not occurred, and notifies that fact. This notification destination and notification means are the same as the notification of failure occurrence in step S212. Note that the failure detection unit 115 may advance the process to step S215 without performing the process of step S214.
In step S215, the failure detection unit 115 cancels the failure diagnosis mode. At this time, when it is determined that no failure has occurred, the operation mode of the motor control system 1 is set to the normal mode, and control of the motor 20 is started. When it is determined that a failure has occurred, the motor 20 is not controlled by setting the operation mode of the motor control system 1 to the maintenance mode or the like.

Next, with reference to FIG. 5A, an operation example of failure diagnosis processing will be described.
A line L43 in FIG. 5A represents a change over time of the actual current flowing through the electric wire 21A and detected by the current sensor 12A. As can be seen from the line L43, the magnitude of the actual current is always larger than the failure determination current value during the steady period C. Therefore, the electric wire 21A is not determined to be in the failure count state in step S205. Therefore, if the state shown in FIG. 5A continues for the diagnosis period Y, the failure counter of the electric wire 21A is not incremented and is maintained as 0, and it is not determined that the electric wire 21A is disconnected.

Next, another operation example of the failure diagnosis process will be described with reference to FIG. 5B. FIG. 5B is a diagram showing the second current graph in the upper stage, and a diagram showing a change in the failure counter of the electric wire 21A in the lower stage.
The horizontal axis of the second current graph is time, and the vertical axis is the current value of the electric wire 21A. Line L41 and line L42 are the same as those in the first current graph of FIG. 5A.
Line L51 represents the change over time of the actual current of the electric wire 21A, and represents an example different from FIG. 5A. As can be seen from the line L51, when the actual current is in the steady period C, the state below the failure determination current value continues for the determination period D [seconds] or longer. Therefore, the electric wire 21A is in a failure count state. Therefore, every time the steady period C elapses, the failure counter of the electric wire 21A is incremented in step S206. This state is shown in the lower part of FIG. 5B.
As described above, when the state shown in the upper part of FIG. 5B continues and the failure counter of the electric wire 21A becomes equal to or greater than the failure threshold, it is determined in step S211 of FIG. 4 that the electric wire 21A is broken.

[effect]
As described above, the q-axis current determination unit 112 obtains a plurality of q-axis currents that cause the target currents of the first to third current patterns to flow through the electric wires 21A, B, and C. Then, the smallest value among the obtained absolute values of the q-axis current is set as the absolute value, and the diagnostic q-axis current whose polarity is inverted at a predetermined timing is determined.
The output current control unit 114 performs control to output the output current to the electric wire 21 based on the diagnostic q-axis current and the diagnostic d-axis current.
The failure detection unit 115 detects disconnection of the electric wire 21 based on the actual current of the electric wire 21.

Therefore, when the disconnection of the electric wire 21 is detected, the q-axis current is reduced, so that the torque and rotation of the motor 20 can be suppressed.
Further, the polarity of the diagnostic q-axis current is inverted at a predetermined timing. Therefore, even when the motor 20 rotates when detecting the disconnection of the electric wire 21, the rotation direction of the motor 20 is reversed at every predetermined timing. Therefore, rotation of the motor 20 when detecting disconnection of the motor 20 can be suppressed. For this reason, when the disconnection of the motor is detected, it is possible to prevent the user from feeling uncomfortable due to the rotation of the motor.
Further, the motor control device 100 does not require a dedicated circuit for detecting the disconnection of the electric wire 21. Therefore, the motor control device 100 can suppress an increase in capacity (volume) necessary for this dedicated circuit.

The target current is a current having a constant current value. Therefore, rotation of the motor 20 can be suppressed.
Moreover, the failure detection unit 115 starts detecting the disconnection of the electric wire 21 when the motor control device 100 is activated. Therefore, when the electric wire 21 is disconnected, this disconnection can be detected before the motor control device 100 controls the motor 20 in the normal mode, so that stable operation of the motor 20 can be realized.

In addition, the q-axis current determination unit 112 and the d-axis current determination unit 113 obtain a q-axis current and a d-axis current that are the target currents of the first to third current patterns based on the motor angle. Accordingly, it is possible to obtain the q-axis current and the d-axis current so as to be the target currents of the first to third current patterns regardless of the value of the motor angle.
The output current control unit 114 controls the output current during the transient period and the steady period. In the transition period, the output current is controlled so as to approach the target current of the current pattern corresponding to the diagnostic q-axis current at a predetermined change rate. Therefore, it can suppress that the output current of the electric wire 21 fluctuates greatly and the torque of the motor 20 fluctuates. Therefore, vibrations and sounds caused by the motor 20 can be suppressed.

Moreover, the failure detection part 115 determines whether the electric wire 21 is in a failure count state during a steady period, and detects the disconnection of the electric wire 21. The failure count state is a state in which the state where the actual current flowing through the electric wire 21 is equal to or less than the failure determination current value continues for the determination period D or longer. In the steady period, the output current is stable. Therefore, the possibility of detecting a disconnection by mistake is reduced.
Further, every time the polarity of the diagnostic q-axis current is reversed, the failure detection unit 115 determines whether or not the electric wire 21 is in the failure count state, and whether or not the failure count state for each of the electric wires 21 has exceeded the failure threshold value. Determine. Then, the failure detection unit 115 determines that the wire 21 in which the failure count state has occurred more than the failure threshold is disconnected. Therefore, the accuracy of detection of disconnection is improved.

  Further, when the failure detection unit 115 detects that any of the electric wires 21 is disconnected during the diagnosis period Y, the failure detection unit 115 ends the detection of the disconnection of the electric wires 21. Therefore, when any of the electric wires 21 is disconnected, the user or the like knows that the electric wires 21 are disconnected early.

Second Embodiment
Next, the motor control system 1 of this embodiment will be described. In addition, about the point similar to 1st Embodiment, description is abbreviate | omitted using the same code | symbol, and it demonstrates centering on a different point from 1st Embodiment.

  First, the current pattern of this embodiment will be described. In the present embodiment, unlike the first embodiment, the first type and the second type are not provided in the current pattern. The first to third current patterns in the present embodiment are either the first type or the second type in the first to third current patterns in the first embodiment, respectively. For example, in the present embodiment, the first to third current patterns are the first types of the first to third current patterns of the first embodiment, respectively.

Next, the current control process of this embodiment will be described with reference to FIG. FIG. 6 is a flowchart of the current control process.
In step S300, the current control unit 111 determines whether or not the operation mode of the motor control system 1 is the failure diagnosis mode. The determination method is the same as step S100 in FIG. The current control unit 111 proceeds to step S301 when the operation mode is the failure diagnosis mode, and executes step S300 again when the operation mode is not the failure diagnosis mode.
In step S <b> 301, the angle detection unit 140 outputs a motor angle based on the output of the motor angle sensor 13 to the current control unit 111.

In step S302, the q-axis current determination unit 112 calculates a q-axis current Iqf1 such that the target current of the first current pattern flows. In addition, the d-axis current determination unit calculates a d-axis current Idf1 such that the target current of the first current pattern flows.
In step S303, the q-axis current determination unit 112 calculates a q-axis current Iqf2 such that the target current of the second current pattern flows. The d-axis current determination unit calculates a d-axis current Idf2 that allows the target current of the second current pattern to flow.
In step S304, the q-axis current determination unit 112 calculates a q-axis current Iqf3 such that the target current of the third current pattern flows. The d-axis current determination unit calculates a d-axis current Idf3 that allows the target current of the third current pattern to flow.

In step S305, the q-axis current determining unit 112 determines the q-axis currents Iqf1 to Iqf3 having the smallest absolute value as a provisional diagnostic q-axis current.
In step S306, the d-axis current determination unit 113 uses the d-axis current of the current pattern corresponding to the temporary diagnosis q-axis current among the d-axis currents Idf1 to Idf3 calculated in steps S302 to S304 for temporary diagnosis. Determined as d-axis current. That is, when the temporary diagnostic q-axis current is the q-axis current Iqf1, the temporary diagnostic d-axis current is the d-axis current Idf1. When the temporary diagnostic q-axis current is the q-axis current Iqf2, the temporary diagnostic d-axis current is the d-axis current Idf2. When the temporary diagnostic q-axis current is the q-axis current Iqf3, the temporary diagnostic d-axis current is the d-axis current Idf3.

  In step S307, the q-axis current determination unit 112 determines whether or not the diagnostic q-axis current determined in the previous step S309 or step S311 is negative. The q-axis current determining unit 112 advances the process to step S308 when the previously determined q-axis current for diagnosis is negative, and advances the process to step S310 when positive.

In step S308, the q-axis current determining unit 112 determines a diagnostic q-axis current that is a positive value from the temporary diagnostic q-axis current. Specifically, when the temporary diagnostic q-axis current is positive, the temporary diagnostic q-axis current is determined as it is as the diagnostic q-axis current without inverting the polarity. Further, when the temporary diagnostic q-axis current is negative, the polarity of the temporary diagnostic q-axis current is reversed to determine the diagnostic q-axis current.
In step S309, the d-axis current determination unit 113 determines a diagnostic d-axis current corresponding to the diagnostic q-axis current from the temporary diagnostic q-axis current. Specifically, in step S308, when the diagnosis q-axis current is obtained without reversing the polarity of the temporary diagnostic q-axis current, the temporary diagnosis d-axis current is directly diagnosed without reversing the polarity. The d-axis current is determined. In step S308, when the polarity of the temporary diagnostic q-axis current is reversed to obtain the diagnostic q-axis current, the polarity of the temporary diagnostic d-axis current is reversed and determined as the diagnostic d-axis current. To do.

In step S310, the q-axis current determining unit 112 determines a diagnostic q-axis current that is a negative value from the temporary diagnostic q-axis current. Specifically, when the temporary diagnostic q-axis current is negative, the temporary diagnostic q-axis current is determined as it is as the diagnostic q-axis current without inverting the polarity. Further, when the temporary diagnostic q-axis current is positive, the polarity of the temporary diagnostic q-axis current is reversed to determine the diagnostic q-axis current.
In step S311, the d-axis current determining unit 113 determines a diagnostic d-axis current corresponding to the diagnostic q-axis current from the temporary diagnostic q-axis current. Specifically, in step S310, when the diagnostic q-axis current is used without inverting the polarity of the temporary diagnostic q-axis current, the temporary diagnostic d-axis current is directly diagnosed without inverting the polarity. The d-axis current is determined. In step S310, when the polarity of the temporary diagnostic q-axis current is reversed to obtain the diagnostic q-axis current, the polarity of the temporary diagnostic d-axis current is reversed and determined as the diagnostic d-axis current. To do.

  In step S312, the output current control unit 114 controls the output current of the electric wire 21 based on the diagnostic q-axis current and the diagnostic d-axis current. The process in step S312 is the same as the process in step S111 in FIG. After the process of step S312 ends, the output current control unit 114 returns the process to step S300.

Also in the current control process of the present embodiment shown in FIG. 6, the target current and the output current as shown in FIG. 5A are obtained as in the current control process of the first embodiment shown in FIG. 3.
That is, the target current of the electric wire 21 calculated from the diagnostic q-axis current and the diagnostic d-axis current is reversed between positive and negative in a cycle of “transient period B + steady period C”. This is because the q-axis current for diagnosis determined in step S308 or S310 in FIG. 6 is reversed in polarity every time it is determined in step S308 or S310.
Further, the output current is controlled so as to approach the target current at a predetermined change rate during the transition period B by the control in step S312. Further, after the transition period B elapses, during the steady period C, the output current is controlled to match the target current.
Also in this embodiment, the same failure diagnosis processing as that of the first embodiment shown in FIG. 4 is performed, and disconnection of the electric wire 21 is detected.

As described above, the q-axis current determination unit 112 obtains a plurality of q-axis currents that cause the currents of the first to third current patterns to flow through the electric wires 21A, B, and C. Among the obtained q-axis currents, the q-axis current having the smallest absolute value is set as a temporary diagnostic q-axis current. Then, the polarity of the provisional diagnostic q-axis current is determined and determined as the diagnostic q-axis current so that the polarity is inverted every time the diagnostic q-axis current is determined.
Therefore, it is not necessary to have the first type and the second type as in the first embodiment for each of the first to third current patterns, and the processing can be simplified.
Note that the motor control system 1 of the present embodiment has the same effects as the motor control system 1 of the first embodiment.

In the current control process illustrated in FIG. 6, the output current control unit 114 returns the process to step S300 after step S312. That is, in the current control process shown in FIG. 6, every time the diagnostic q-axis current is determined, the q-axis current and the d-axis current are calculated in steps S302 to S304 prior to the determination. In steps S305 and S306, a temporary diagnostic q-axis current and a temporary diagnostic d-axis current are determined.
However, the output current control unit 114 may return the process to step S307 after step S312. That is, when determining the first diagnostic d-axis current, the q-axis current and the d-axis current are calculated, and the temporary diagnostic q-axis current and the temporary diagnostic d-axis current are determined. When determining the diagnostic d-axis current for the second and subsequent times, this temporary diagnostic d-axis current may be used.
Thereby, the calculation amount of the motor control apparatus 100 decreases, and the load can be reduced. Further, even if such processing is performed, the motor angle does not change greatly, so that an error occurs in the diagnostic q-axis current and the diagnostic d-axis current in the steady period, and the output current does not match the target current. There is little fear.

<Other embodiments>
In the above embodiment, as described in the failure diagnosis processing of FIG. 4, when any failure counter reaches the failure threshold value in step S211, a failure occurrence is notified and the failure diagnosis processing ends. That is, the failure diagnosis process is completed when a disconnection is detected in one of the electric wires 21.
However, the failure detection unit 115 performs the process of determining the failure count state of the electric wires 21A, B, and C in the failure diagnosis process and incrementing the failure counter according to the determination result over the diagnosis period Y. Also good. In this case, the failure detection unit 115 determines whether or not the failure counter of each of the electric wires 21A, B, and C is greater than or equal to the failure threshold after the diagnosis period Y has elapsed.
Thereby, in the failure diagnosis processing, even when the disconnection has occurred in a plurality of the electric wires 21, all the disconnected electric wires 21 can be detected.

In addition, the failure detection unit 115 performs a process of determining the failure count state of the electric wires 21A, B, and C in the failure diagnosis process and incrementing the failure counter according to the determination result. Alternatively, it may be performed until the diagnosis period Y elapses.
Thereby, in the failure diagnosis processing, even when the disconnection has occurred in a plurality of the electric wires 21, all the disconnected electric wires 21 can be detected. If all the failure counters are equal to or greater than the failure threshold before the diagnosis period Y elapses, the process of incrementing the failure counter is terminated before the diagnosis period Y elapses. You can save time.

  In the above embodiment, the failure detection unit 115 detects a disconnection of the electric wire 21 as a failure of the electric wire 21. However, the failure detection unit 115 may detect that the thickness of the electric wire 21 has become a predetermined thickness or less as a failure of the electric wire 21 by adjusting the failure determination current value or the like. Thereby, the change in the state of the electric wire 21 can be detected before the electric wire 21 is disconnected.

The motor control system 1 described above can be applied to a system or apparatus that uses the motor 20 driven by a three-phase alternating current. For example, the motor control system 1 may be applied to an electric vehicle or an electric motorcycle.
Consider an electric motorcycle with a motor control system 1. It is assumed that the power supply of the motor control device 100 of the motor control system 1 is turned on with the center stand of this electric motorcycle set up and the rear wheel floating. At this time, the motor control system 1 is in a failure diagnosis mode, and the above-described failure diagnosis processing and current control processing are started. However, since the rotation of the motor 20 is suppressed as described above, the rotation of the floating rear wheel is suppressed. Therefore, it is possible to reduce a possibility that the rear wheel rotates and the user feels uncomfortable when the control for rotating the motor 20 is not performed.

  As mentioned above, although embodiment of this invention was described, the said embodiment was shown as an example and is not intending limiting the range of invention. The above-described embodiment can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. The above-described embodiments and modifications thereof are included in the invention described in the claims and equivalents thereof, as long as they are included in the scope and gist of the invention.

  The present invention supplies a program that realizes one or more functions of the above-described embodiments to a system or apparatus via a network or a storage medium, and one or more processors in a computer of the system or apparatus read and execute the program This process can be realized. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

  DESCRIPTION OF SYMBOLS 1 Motor control system, 20 Motor, 21 Electric wire, 100 Motor control apparatus, 110 Failure diagnosis part, 111 Current control part, 112 q-axis current determination part, 113 d-axis current determination part, 114 Output current control part, 115 Failure detection part

Claims (6)

A motor controller that controls a motor that is driven by a three-phase alternating current and includes three electric wires through which the three-phase alternating current flows.
A q-axis current is determined for each of a plurality of current patterns of a target current that is a current flowing through the three wires, and the smallest value among the determined absolute values of the q-axis currents is an absolute value, and the polarity is a predetermined timing. Q-axis current determining means for determining a diagnostic q-axis current that is reversed at
Output current control means for performing control to output a current to the electric wire based on the diagnostic q-axis current and a diagnostic d-axis current that is a d-axis current corresponding to the diagnostic q-axis current;
A motor control device comprising: failure detection means for detecting a failure of the motor based on an actual current that is a current flowing through the electric wire.   The motor control device according to claim 1, wherein a current value of the target current is constant.   The motor control device according to claim 1, wherein the failure detection unit starts detecting the failure of the motor when the motor control device is started. Each of the plurality of current patterns has two types in which polarities of the target current are opposite to each other,
The q-axis current determining means alternately changes the type of the current pattern every time the diagnostic q-axis current is determined, and sets the target of the type of the current pattern to the wire for each of the plurality of current patterns. 4. A q-axis current that causes a current to flow is determined, and a q-axis current having the smallest absolute value among the determined q-axis currents is determined as the diagnostic q-axis current. The motor control device according to any one of the above. The q-axis current determining means determines a q-axis current for each of the plurality of current patterns, and uses a q-axis current having the smallest absolute value among the determined q-axis currents of the plurality of current patterns for provisional diagnosis. q-axis current is determined and determined as the diagnostic q-axis current by determining the polarity of the temporary diagnostic q-axis current so that the polarity is reversed every time the diagnostic q-axis current is determined.
When the d-axis current corresponding to the temporary diagnostic q-axis current is a temporary diagnostic d-axis current, the diagnostic d-axis current is calculated by the q-axis current determination means by the temporary diagnostic q-axis current. When the diagnostic q-axis current is determined by reversing the polarity, the provisional diagnostic d-axis current is reversed in polarity, and the q-axis current determining means determines the polarity of the temporary diagnostic q-axis current. 4. The motor control device according to claim 1, wherein when the diagnostic q-axis current is determined while maintaining the polarity, the provisional diagnostic d-axis current is maintained in polarity. 5. The output current control means, as a control of the current output to the electric wire, to control the current during the transient period,
6. The transient period is a period including a period in which the output current approaches the target current of the current pattern corresponding to the diagnostic q-axis current at a predetermined rate of change. The motor control device according to any one of claims.

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