TWI833808B - Motor control circuit and motor control apparatus - Google Patents

Abstract

Subject of this invention is to obtain a motor control circuit capable of improving the accuracy of motor control. A motor control circuit 3-1 includes a control circuit 11 that controls switching operation of an inverter circuit which supplies AC power to motor, and a determination information generating circuit 12 that generates a conversion result that is a determination information for determining whether the motor is in a breakdown or deterioration. The motor control circuit 3-1 includes a determining circuit 10 that determines whether the motor is in a breakdown or deterioration state based on the conversion result, and outputs a signal indicating that the motor is in a breakdown or deterioration state to the control circuit 11 as an interrupt signal.

Description

Motor control circuit and motor control device

The present invention relates to a motor control circuit and a motor control device that control switching operations of an inverter circuit that supplies AC power to a motor.

Patent Document 1 discloses a technology for controlling the switching operation of an inverter circuit. Motor control is an operation that changes the energization rate of the pulse width modulation (PWM) signal used to control the operation of the switching element of the inverter circuit so that the rotation speed of the motor follows the value of the speed command signal.

[Prior technical literature] [Patent Document]

Patent Document 1: Japanese Patent Application Publication No. 2018-107914.

However, in the prior art represented by Patent Document 1, the control unit including the arithmetic processing function for controlling the motor also performs abnormality determination for determining whether the motor is malfunctioning or deteriorating, and determining whether the speed command signal has expired. Determining the speed of change, etc. Therefore, compared with the case where the control unit only performs motor control, there is a problem that the processing load of the control unit increases, the responsiveness of the motor control to changes in the speed command signal decreases, and the motor control cannot be performed with high accuracy.

The present invention is proposed in view of the above problems, and its purpose is to provide a method to alleviate the A motor control circuit that eliminates the processing burden on the control unit of the arithmetic processing function of motor control and improves the accuracy of motor control.

The motor control circuit according to the embodiment of the present invention includes: a control circuit that controls the switching operation of an inverter circuit that supplies AC power to the motor; and a determination information generation circuit that generates a determination for determining whether the motor is malfunctioning or deteriorating. information. The motor control circuit includes a determination circuit that determines whether the motor is malfunctioning or deteriorating based on the determination information, and outputs information indicating that the motor is malfunctioning or deteriorating as an interrupt signal to the control circuit 11 .

The motor control circuit of the present invention has the effect of improving the accuracy of motor control.

1:Inverter circuit

2: Drive signal generation circuit

3-1, 3-1A, 3-2, 3-2’, 3-2A, 3-3, 3-4, 300, 400: Motor control circuit

4: Motor

4-1: Shell

4-2:Bearing lining

4-3:Bearing

4-4:Insulator

4-5:Iron core

4-6: Coil

4-7:Printed substrate

5:Current detection part

6: Temperature detection department

6A: IC temperature detection department

6B: Bearing lining temperature detection part

6C: Motor external temperature detection part

7: Power supply voltage detection department

8:AD converter

9:AD sequencer

10, 10A, 10B: Determination circuit

11, 11A: Control circuit

12: Determination information generation circuit

13:Notification terminal

20, 20’: Speed change detection circuit

20A: Capture timer

21: No. 1 catcher

22: 2nd catcher

23: Counter clock

24, 24A: Comparison circuit

25:Catcher

31, 31’, 31A: control circuit

40, 60: Judgment value

50:Input terminal

71, 72, 73: 1st count value

81, 82, 83: 2nd count value

91, 92, 93: count value

100-1, 100-2, 100-3, 100-4: Motor control device

410: IC

T1, T2: Fixed period

FIG. 1 is a diagram showing the structure of a motor control device according to Embodiment 1.

FIG. 2 is a diagram showing the structure of the motor control circuit according to the first embodiment.

FIG. 3 is a sequence chart for explaining the operation of the motor control circuit according to the first embodiment.

FIG. 4 is a flow chart for explaining the operation of the motor control circuit according to the first embodiment.

FIG. 5 is a time chart for explaining the operation of the motor control circuit according to the first embodiment.

FIG. 6 is a diagram showing the structure of a motor control circuit according to a comparative example of Embodiment 1. FIG.

FIG. 7 is a sequence diagram for explaining the operation of the motor control circuit in the comparative example of Embodiment 1. FIG.

FIG. 8 is a flowchart for explaining the operation of the motor control circuit in the comparative example of Embodiment 1. FIG.

FIG. 9 is a time chart for explaining the operation of the motor control circuit in the comparative example of Embodiment 1. FIG.

FIG. 10 is a diagram showing a modification of the motor control circuit of Embodiment 1. FIG.

FIG. 11 is a diagram showing the structure of a motor control device according to Embodiment 2. FIG.

Fig. 12 is a diagram showing the structure of a motor control circuit according to Embodiment 2.

FIG. 13 is a diagram showing the structure of a conventional motor control circuit.

FIG. 14 is a sequence diagram for explaining the operation of the motor control circuit according to the second embodiment.

FIG. 15 is a flowchart for explaining the operation of the motor control circuit according to the second embodiment.

FIG. 16 is a time chart for explaining the operation of the motor control circuit according to the second embodiment.

FIG. 17 is a diagram showing the structure of a motor control circuit according to a comparative example of Embodiment 2.

FIG. 18 is a sequence diagram for explaining the operation of the motor control circuit in the comparative example of Embodiment 2. FIG.

FIG. 19 is a flowchart for explaining the operation of the motor control circuit in the comparative example of Embodiment 2. FIG.

FIG. 20 is a time chart for explaining the operation of the motor control circuit in the comparative example of Embodiment 2. FIG.

FIG. 21 is a diagram showing a modification of the motor control circuit of Embodiment 2. FIG.

FIG. 22 is a flowchart for explaining the operation of the motor control circuit shown in FIG. 21 .

FIG. 23 is a diagram showing the structure of a motor control device according to Embodiment 3. FIG.

FIG. 24 is a diagram showing a structural example of the motor 4 .

FIG. 25 is a diagram showing the structure of a motor control circuit according to Embodiment 3. FIG.

Fig. 26 is a flowchart for explaining the operation of the motor control circuit according to the third embodiment.

FIG. 27 is a diagram showing an example of IC (integrated circuit) internal temperature and bearing liner temperature in Embodiment 3. FIG.

Fig. 28 is a diagram showing the structure of the motor control device according to the fourth embodiment.

Fig. 29 is a diagram showing the structure of the motor control circuit according to the fourth embodiment.

Fig. 30 is a flowchart for explaining the operation of the motor control circuit according to the fourth embodiment.

31 is a first diagram showing an example of IC internal temperature, bearing lining temperature, motor external temperature, etc. in Embodiment 4.

32 is a second diagram showing an example of IC internal temperature, bearing lining temperature, motor external temperature, etc. in Embodiment 4.

Hereinafter, the structures of the motor control circuit and the motor control device according to the embodiment of the present invention will be described in detail based on the drawings. In addition, this invention is not limited by this embodiment.

(Embodiment 1)

FIG. 1 is a diagram showing the structure of a motor control device according to Embodiment 1. The motor control device 100 - 1 includes an inverter circuit 1 that supplies AC power to the motor 4 and a drive signal generation circuit 2 that generates a drive signal for operating a switching element provided in the inverter circuit 1 . Furthermore, the motor control device 100-1 includes a motor control circuit 3-1 that generates a PWM signal for controlling the operation of the switching element of the inverter circuit 1. In FIG. 1 , illustrations of a rectifier circuit, a converter circuit, an AC power supply, and the like that supply DC power to the inverter circuit 1 are omitted. The motor 4 is a rotary electric machine rotated by AC power. The drive signal is a signal in which the PWM signal input to the drive signal generation circuit 2 is converted into a voltage capable of driving the switching element. The PWM signal is a rectangular wave signal with two values of high level or low level used to control switching operations.

Next, the structure of the motor control circuit 3-1 will be described. FIG. 2 is a diagram showing the structure of the motor control circuit according to the first embodiment. The motor control circuit 3-1 includes a control circuit 11 that generates a PWM signal, and a determination information generation circuit 12 that generates determination information for determining whether the motor 4 is malfunctioning or deteriorating. In addition, the motor control circuit 3-1 is provided with a determination circuit 10 that determines whether the motor 4 is malfunctioning or degrading based on the determination information generated by the determination information generation circuit 12, and uses a signal indicating that the motor 4 is malfunctioning or degrading as an interrupt. The signal is output to the control circuit 11 including the arithmetic processing function. The determination circuit 10 is used to replace the operation implemented in the conventional control circuit 11 A circuit that reduces the processing load of the control circuit 11 by performing calculation processing. In addition, when the judgment information is measured for a long period of time, the deterioration of the motor 4 is judged by detecting slight changes in the judgment information.

The determination information generated by the determination information generation circuit 12 is information in which at least one of current detection information, temperature detection information, and voltage detection information is converted into a digital value by an AD (analog-digital; digital-analog) converter 8, where the current The detection information indicates the value of the current detected by the current detection unit 5 , the temperature detection information indicates the value of the temperature detected by the temperature detection unit 6 , and the voltage detection information indicates the power supply detected by the power supply voltage detection unit 7 voltage value. In addition, the detection information input to the determination information generation circuit 12 is not limited to current detection information, temperature detection information, and voltage detection information as long as it is information necessary for determining whether the motor 4 is malfunctioning or deteriorating. The determination information generated by the determination information generation circuit 12 in this way is information obtained by converting the detection information detected by the current detection unit 5 and the like into a digital value using the AD converter 8, and is therefore sometimes referred to as a "conversion result" below.

The determination information generation circuit 12 includes an AD converter 8 and an AD sequencer 9 . The AD converter 8 converts at least one of current detection information, temperature detection information, and voltage detection information into a digital value, and outputs the conversion result to the AD sequencer 9 . The AD sequencer 9 holds the conversion result, and the decision circuit 10 reads the conversion result held by the AD sequencer 9 .

The determination circuit 10 is provided with a determination value 40 for comparing each of the current detection information, the temperature detection information, and the voltage detection information. For example, the determination value 40 is set based on the current, temperature, and power supply voltage detected when the motor 4 is malfunctioning or degrading.

Next, the operation of the motor control circuit 3-1 will be described. FIG. 3 is a sequence diagram for explaining the operation of the motor control circuit according to the first embodiment. FIG. 4 is a flowchart for explaining the operation of the motor control circuit according to the first embodiment. The control circuit 11 performs motor control based on the speed command signal (step S1). The speed command signal is a signal that specifies a target value of the rotation speed of the motor 4 .

When receiving current detection information, temperature detection information and voltage detection information, The AD converter 8 at least converts the values of the detection information into digital values that can be processed by the AD sequencer 9 . The AD sequencer 9 holds the conversion result of the AD converter 8 every fixed period, and outputs a conversion completion signal every time this period elapses. The conversion end signal is a signal indicating that holding of the conversion result in this cycle has ended.

The determination circuit 10 determines whether the conversion end signal is received (step S2). If the conversion completion signal is not received (NO in step S2), the processing of steps S1 and S2 is repeated. When the conversion completion signal is received (YES in step S2), the determination circuit 10 reads the conversion result held by the AD sequencer 9 (step S3).

The determination circuit 10 compares the read conversion result value with a preset determination value 40, and determines whether the conversion result value is equal to or greater than the determination value 40 (step S4). When the value of the conversion result is smaller than the determination value 40 (NO in step S4), the processing from step S1 to step S4 is repeated. When the value of the conversion result is equal to or greater than the judgment value 40 (YES in step S4), the judgment circuit 10 outputs an interrupt signal (step S5). The interrupt signal is a signal notifying that the value of the conversion result is equal to or greater than the judgment value 40. . The control circuit 11 that has received the interrupt signal performs, for example, external notification (step S6), which is an operation of outputting a signal that notifies an external device that the motor 4 is malfunctioning or deteriorating. In addition, the judgment circuit 10 may output an external notification at the timing of outputting the interrupt signal.

FIG. 5 is a time chart for explaining the operation of the motor control circuit according to the first embodiment. FIG. 5 shows the operating state of the control circuit 11, the timing of the conversion completion signal change, the conversion result, the timing of the judgment process of the judgment circuit 10, and the timing of the interrupt signal change. When the control circuit 11 performs motor control, when the first conversion end signal changes from low to high, a fixed period elapses from the time point when the conversion end signal changes from low to high. Until T1, the determination circuit 10 performs determination processing. The determination process corresponds to the process of step S4 for determining whether the value of the conversion result is equal to or greater than the determination value 40. Since the determination process is performed by the determination circuit 10, the motor control by the control circuit 11 is not interrupted. In this determination process, for example, because the value of the current detection information is smaller than the determination value 40, so the interrupt signal is low. In addition, the conversion end signal changes to low again immediately after changing from low to high.

During motor control, when the second conversion completion signal changes from low to high, the determination circuit 10 determines the motor 4 from the time point when the conversion completion signal changes from low to high until the fixed period T2 elapses. Determining whether there is a malfunction or deterioration. In this determination process, for example, since the value of the current detection information is equal to or greater than the determination value 40, the interrupt signal changes from low to high. Thereby, the motor control of the control circuit 11 is interrupted, and external notification is performed.

FIG. 6 is a diagram showing the structure of a motor control circuit according to a comparative example of Embodiment 1. FIG. The motor control circuit 300 shown in FIG. 6 includes a control circuit 11A in place of the determination circuit 10 and the control circuit 11 shown in FIG. 2 . In the control circuit 11A, the aforementioned motor control and determination processing are performed.

Next, the operation of the motor control circuit 300 will be described. FIG. 7 is a sequence diagram for explaining the operation of the motor control circuit in the comparative example of Embodiment 1. FIG. FIG. 8 is a flowchart for explaining the operation of the motor control circuit in the comparative example of Embodiment 1. FIG. The control circuit 11A performs motor control based on the speed command signal (step S11). In the AD converter 8 that receives at least one of the current detection information, temperature detection information, and voltage detection information, the values of these detection information are converted into digital values that can be processed by the AD sequencer 9 . The AD sequencer 9 holds the conversion result of the AD converter 8 every fixed period, and when the period elapses, the AD sequencer 9 outputs a conversion completion signal.

The control circuit 11A determines whether the conversion end signal is received (step S12). If the conversion completion signal is not received (NO in step S12), the processing of steps S11 and S12 is repeated. When receiving the conversion completion signal (YES in step S12), the control circuit 11A reads the conversion result held by the AD sequencer 9 (step S13).

The control circuit 11A compares the read conversion result value with a preset judgment value 40, and determines whether the conversion result value is equal to or higher than the judgment value 40 (step S14). When the value of the conversion result is less than the determination value 40 (NO in step S14), steps S11 to S14 are repeated. handle. When the value of the conversion result is equal to or greater than the judgment value 40 (YES in step S14), the control circuit 11A performs external notification (step S15).

FIG. 9 is a time chart for explaining the operation of the motor control circuit in the comparative example of Embodiment 1. FIG. FIG. 9 shows the operation state of the control circuit 11A, the timing of change of the conversion end signal, and the conversion result. When the control circuit 11A performs motor control, when the first conversion completion signal changes from low to high, the control circuit 11A controls the motor from the time point when the conversion completion signal changes from low to high until the fixed period T1 elapses. Determination processing is performed instead of motor control. The determination process corresponds to the process of step S14 for determining whether the value of the conversion result is equal to or greater than the determination value 40. Since the determination process is performed by the control circuit 11A, the motor control is interrupted until the fixed period T1 elapses. In this determination process, for example, since the value of the current detection information is smaller than the determination value 40, external notification is not performed. In addition, the conversion end signal changes from low to high immediately after changing to low again.

In the control circuit 11A, motor control is resumed after the fixed period T1 has elapsed. When this motor control is performed, when the second conversion end signal changes from low to high, the control circuit 11A performs a determination process from the time when the conversion end signal changes from low to high until the fixed period T2 elapses. . In this determination process, for example, since the value of the current detection information is equal to or greater than the determination value 40, an external notification is performed when the fixed period T2 has elapsed.

In this way, in the motor control circuit 300 of the comparative example, from the time point when the conversion completion signal changes from low to high until the fixed periods T1 and T2 elapse, the determination process performed by the control circuit 11A, that is, the motor 4 Determine whether it is malfunctioning or deteriorating. Therefore, motor control is interrupted during this determination process.

On the other hand, in the motor control circuit 3-1 of Embodiment 1, as shown in FIG. 5, from the time point when the conversion completion signal changes from low to high until the fixed periods T1 and T2 elapse, the determination circuit performs 10. Judgment and processing. That is, the determination circuit 10 is used instead of the arithmetic processing (abnormality determination processing) conventionally performed by the control circuit 11 . Therefore, in the motor control circuit 3-1, with the motor The motor control is continued in parallel with the determination process of whether there is a malfunction or deterioration. Therefore, motor control is not interrupted by this determination process. In this way, since the motor control is not interrupted, for example, even if the value of the speed command signal changes during the fixed periods T1 and T2 shown in FIG. 5 , the motor control can be changed immediately in response to the change in the speed command signal. Specifically, for example, when the on-duty of the speed command signal becomes longer, the energization rate of the PWM signal becomes larger, and when the on-duty of the speed command signal becomes shorter, the energization of the PWM signal becomes larger. rate becomes smaller. As a result, the responsiveness of the motor control accompanying changes in the speed command signal is improved. In addition, the calculation processing (abnormality determination processing) performed by the control circuit 11 is replaced by the determination circuit 10, thereby reducing the processing load of the control circuit 11.

In addition, even when the value of the speed command signal changes frequently in a short period of time, the energization rate of the PWM signal can be changed without delay. Therefore, by using the motor control circuit 3-1, it is possible to perform motor failure determination and motor control. Deterioration determination, etc., and a motor control device 100-1 that can cope with complex motor control is obtained. In addition, as the calculation load on the control circuit 11 is reduced, more complex motor control can be performed. In addition, when it is determined that a failure or deterioration has occurred as a result of motor failure determination, motor deterioration determination, etc., an external notification can be made immediately.

FIG. 10 is a diagram showing a modification of the motor control circuit of Embodiment 1. FIG. The motor control circuit 3-1A shown in FIG. 10 is provided with the notification terminal 13. The notification terminal 13 is electrically connected to the determination circuit 10, for example. The notification terminal 13 is a terminal for notifying at least one of the failure of the motor 4 and the deterioration of the motor 4 to a circuit provided outside the motor control circuit 3-1A. In addition, the notification terminal 13 can be, for example, a metal terminal provided on a printed circuit board provided with the determination information generation circuit 12, the determination circuit 10 and the control circuit 10, or a terminal of a processor constituting the determination circuit 10. Circuit 11.

The judgment circuit 10 causes the value of the voltage applied to the notification terminal 13 to be higher or lower when the value of the conversion result is equal to or higher than the judgment value 40. Know the value of the voltage at terminal 13. That is, the voltage applied to the notification terminal 13 is changed to a different value. A circuit provided outside the motor control circuit 3-1A detects that the change amount of the voltage applied to the notification terminal 13 has increased compared with a predetermined value for detecting a malfunction or deterioration of the motor 4, for example. It is possible to detect that the motor 4 has failed or deteriorated.

By arranging the notification terminal 13 in this way, even if the external notification operation by the control circuit 11 is not performed, whether the motor 4 is malfunctioning, deteriorating, etc. can be communicated to an external circuit only by the voltage change applied to the notification terminal 13 . Therefore, external notification operation of the control circuit 11 is unnecessary, further reducing the calculation load of the control circuit 11 .

(Embodiment 2)

FIG. 11 is a diagram showing the structure of a motor control device according to Embodiment 2. FIG. In the following, the same parts as those in Embodiment 1 are assigned the same reference numerals and their descriptions are omitted, and different parts are explained. The motor control device 100-2 of the second embodiment includes a motor control circuit 3-2 instead of the motor control circuit 3-1 of the first embodiment.

Fig. 12 is a diagram showing the structure of a motor control circuit according to Embodiment 2. The motor control circuit 3-2 of the second embodiment includes a control circuit 31 that generates a PWM signal, and a speed change detection circuit 20. The speed change detection circuit 20 includes a first capturer 21 , a second capturer 22 , a counter clock 23 and a comparison circuit 24 . FIG. 13 is a diagram showing the structure of a conventional motor control circuit. The conventional motor control circuit 3-2' includes a control circuit 31' for generating a PWM signal, and a speed change detection circuit 20'. The speed change detection circuit 20' includes a first catcher 21, a second catcher 22, and a counter clock 23. The counter clock 23 generates a fixed period clock signal. In order to measure the time when the speed command signal is high, the first catcher 21 counts, for example, the clock signal generated during the period from the time when the speed command signal changes from low to high until the speed command signal changes from high to low. Count it and keep the counting result as the first count value. The first catcher 21 is a register that holds a first count value. The first count value of the first catcher 21 is, for example, the speed command Updated when the signal changes from high to low. For example, the second catcher 22 copies the first count value held by the first catcher 21 before the update and holds it as a second count value. The timing for holding the second count value is, for example, the timing when the speed command signal changes from high to low. The second catcher 22 is a register that holds the second count value. The latest first count value held by the first catcher 21 and the latest second count value held by the second catcher 22 are input to the conventional control circuit 31'. The control circuit 31' detects the difference between the first count value and the second count value, that is, the speed difference of the speed command signal, and performs a calculation to determine whether the speed difference is above a certain threshold value. In this way, in the conventional motor control circuit 3-2', the control circuit 31' performs the change determination process of the speed command signal. Even if there is almost no speed difference in the speed command signal, the control circuit 31' performs the process at a fixed speed. The operation to determine whether the speed difference is above a threshold value is performed periodically. In contrast, the motor control circuit 3-2 of Embodiment 2 is configured to use the comparison circuit 24 included in the speed change detection circuit 20 to determine whether the speed difference is equal to or greater than the threshold value, and only when the speed difference exceeds In the case of a threshold value, the control circuit 31 changes the motor control based on the signal from the speed change detection circuit 20, so the processing load of the control circuit 31 is reduced.

The speed change detection circuit 20 is connected to an input terminal 50 for inputting a speed command signal. The speed change detection circuit 20 detects changes in the speed command signal input through the input terminal 50 and outputs a signal indicating that the speed command signal has changed as an interrupt signal to the control circuit 31, thereby changing the energization rate of the PWM signal.

The comparison circuit 24 compares the latest first count value held by the first catcher 21 with the latest second count value held by the second catcher 22, thereby detecting changes in the speed command signal and outputting a signal indicating the speed command. Signal that has changed.

Next, the operation of the motor control circuit 3-2 will be described. FIG. 14 is a sequence diagram for explaining the operation of the motor control circuit according to the second embodiment. FIG. 15 is a flowchart for explaining the operation of the motor control circuit according to the second embodiment. The control circuit 31 performs motor control based on the speed command signal (step S21). When the speed command signal does not change from low to high ("No" in step S22), the process is repeated. Processing of steps S21 and S22. When the speed command signal changes from low to high (YES in step S22), the first catcher 21 counts the clock signal to obtain a first count value (step S23).

Thereafter, the processing of steps S23 and S24 is repeated until the speed command signal changes from high to low ("No" in step S24). When the speed command signal changes from high to low ("Yes" in step S24), the update The first count value of the first catcher 21. At this time, the second catcher 22 holds the first count value just before the update as the second count value (step S25).

Thereafter, the processing of steps S25 and S26 is repeated until the speed command signal changes from low to high ("No" in step S26). When the speed command signal changes from low to high ("YES" in step S26), the comparison The circuit 24 compares the first count value with the second count value and determines whether the second count value is different from the first count value (step S27). When the second count value is the same as the first count value (NO in step S27), the processes from step S21 to step S27 are repeated. When the second count value is different from the first count value (YES in step S27), the comparison circuit 24 outputs an interrupt signal (step S28). The control circuit 31 that has received the interrupt signal changes the motor control (step S29).

FIG. 16 is a time chart for explaining the operation of the motor control circuit according to the second embodiment. FIG. 16 shows the speed command signal, the first count value, the second count value, the interrupt signal, and the operating state of the control circuit 31 . The period shown by T is the change period of the speed command signal. The periods shown by T _on1 , T _on2 , and T _on3 are the time when the speed command signal is high, that is, the time when the speed command signal is on. T _on1 and T _on2 are equal to each other, and T _on3 is shorter than T _on1 and T _on2 . The first count value 71 held by the first catcher 21 corresponds to T _on1 , for example, "10". The first count value 72 corresponds to T _on2 , for example, "10". The first count value 73 corresponds to T _on3 , for example, "3". The second count value 81 held by the second catcher 22 corresponds to the first count value 71, for example, "10". Similarly, the second count value 82 corresponds to the first count value 72 and is "10", and the second count value 83 corresponds to the first count value 73 and is "3".

When the first count value 72 and the second count value 81 are compared, the first count value 72 and the second count value 81 have the same value, so the interrupt signal continues to be low. That is, no interrupt is output signal. When the first count value 73 and the second count value 82 are compared, the first count value 73 and the second count value 82 are different values from each other, so the interrupt signal changes from low to high. That is, an interrupt signal is output. When the interrupt signal is output, the control circuit 31 determines that the speed command signal has changed and generates a PWM signal, that is, changes the motor control so that the rotation speed of the motor 4 follows the value of the changed speed command signal. In the example of FIG. 16 , since the second count value 82 is larger than the first count value 73 , the motor is controlled so as to increase the energization rate of the PWM signal.

In the motor control circuit 3-2 of the second embodiment, the speed change detection circuit 20 performs the speed change determination, so the calculation load of the motor control of the control circuit 31 does not increase due to the speed change determination.

FIG. 17 is a diagram showing the structure of a motor control circuit according to a comparative example of Embodiment 2. The motor control circuit 400 shown in FIG. 17 includes a capturer timer 20A and a control circuit 31A instead of the speed change detection circuit 20 and the control circuit 31 shown in FIG. 12 . Motor control and speed change determination are performed in the control circuit 31A. The catcher timer 20A includes a counter clock 23 and a catcher 25 . In order to measure the time when the speed command signal is high, the catcher 25 counts the clock signals generated during the period from the time when the speed command signal changes from low to high until the speed command signal changes from high to low, for example. And the count result is retained as the count value. The clock signal is a signal output from the counter clock 23 .

Next, the operation of the motor control circuit 400 will be described. FIG. 18 is a sequence diagram for explaining the operation of the motor control circuit in the comparative example of Embodiment 2. FIG. FIG. 19 is a flowchart for explaining the operation of the motor control circuit in the comparative example of Embodiment 2. FIG. In the control circuit 31A, the motor is controlled based on the speed command signal (step S31). When the speed command signal does not change from low to high (NO in step S32), the processes of steps S31 and S32 are repeated. When the speed command signal changes from low to high (YES in step S32), the catcher 25 counts the clock signal to obtain a count value (step S33).

Thereafter, the processing of steps S33 and S34 is repeated until the speed command signal changes from high to low ("No" in step S34). When the speed command signal changes from high to low ("Yes" in step S34), the update The count value catcher 25 outputs a counter update signal indicating that the count value has been updated (step S35).

The control circuit 31A that receives the counter update signal reads the count value held by the catcher 25 (step S36), and compares the count value before the update with the count value after the update (step S37). If the result of the comparison is that the count values are the same (NO in step S37), the processes of steps S36 and S37 are repeated. When the count values are different (YES in step S37), the control circuit 31A changes the motor control (step S38). In this way, the control circuit 31A maintains the count value before the update while performing motor control, and compares the count value before the update with the count value after the update.

FIG. 20 is a time chart for explaining the operation of the motor control circuit in the comparative example of Embodiment 2. FIG. FIG. 20 shows the speed command signal, count value, counter update signal, timing of detecting the speed change, and the operating state of the control circuit. The periods shown by T _on1 , T _on2 , and T _on3 are the time when the speed command signal is high, that is, the time when the speed command signal is on. T _on1 and T _on2 are equal to each other, and T _on3 is shorter than T _on1 and T _on2 . The count value 91 corresponds to T _on1 , for example, "10". The count value 92 corresponds to T _on2 , for example, "10". The count value 93 corresponds to T _on3 , for example, "3".

When the count value 91 and the count value 92 are compared, since the count value 91 and the count value 92 have the same value, no speed change is detected. When the count value 92 and the count value 93 are compared, since the count value 92 and the count value 93 are different values from each other, a speed change is detected. When the speed change is detected, the control circuit 31A determines that the speed command signal has changed and changes the energization rate of the PWM signal so that the rotation speed of the motor 4 follows the value of the changed speed command signal. In the motor control circuit 400 of the comparative example, since the control circuit 31A performs the speed change determination, the calculation load of the control circuit 31A increases compared with the case where only motor control calculations are performed.

On the other hand, in the motor control circuit 3-2 of the second embodiment, the speed change detection The measuring circuit 20 determines the speed change. Therefore, the control circuit 31 can perform only motor control. Therefore, the calculation load of the control circuit 31 is reduced, and even if the speed command signal has changed, the motor control can be immediately changed in response to the change in the speed command signal. As a result, the responsiveness of the motor control accompanying changes in the speed command signal is improved. In addition, even when the value of the speed command signal changes frequently in a short period of time, the energization rate of the PWM signal can be changed without delay. Therefore, the motor control device 100-2 can also be obtained that can cope with complex motor control. In addition, more complex motor control can be performed while reducing the calculation load on the control circuit 31 .

FIG. 21 is a diagram showing a modification of the motor control circuit of Embodiment 2. FIG. The speed change detection circuit 20 of the motor control circuit 3-2A shown in FIG. 21 includes a comparison circuit 24A instead of the comparison circuit 24. In the comparison circuit 24A, the difference between the speed command signal before the change and the speed command signal after the change is calculated, and the difference is compared with the determination value 60 set in the comparison circuit 24A. In addition, the comparison circuit 24A does not output an interrupt signal when the difference value is smaller than the judgment value 60 as a result of comparing the difference value with the judgment value 60, but outputs an interrupt signal when the difference value is equal to or greater than the judgment value 60. In addition, the determination processing of the comparison circuit 24A is not limited to this, and the comparison circuit 24A may be configured not to output an interrupt signal when the difference is equal to or less than the determination value 60, but to output an interrupt signal when the difference exceeds the determination value 60.

Next, the operation of the motor control circuit 3-2A will be described. FIG. 22 is a flowchart for explaining the operation of the motor control circuit shown in FIG. 21 . The processing from step S21 to step S27 shown in FIG. 22 is the same as the processing from step S21 to step S27 shown in FIG. 15 , so the description is omitted.

After the processing of step S27, the comparison circuit 24A calculates the difference between the speed command signal before the change and the speed command signal after the change. That is, the difference between the first count value held by the first catcher 21 and the second count value held by the second catcher 22 is calculated. The comparison circuit 24A determines whether the calculated difference is equal to or greater than the determination value 60 (YES in step S30). When the difference is smaller than the determination value 60 (NO in step S30), the processes from steps S21 to S30 are repeated. If the calculated difference is equal to or greater than the judgment value 60 (YES in step S30), steps S28 and S29 are repeated. processing. The processing of steps S28 and S29 is the same as the processing of steps S28 and S29 shown in FIG. 15 , so the description thereof is omitted.

For example, when the first count value is "3" and the second count value is "10", the difference is "7". Furthermore, when the value of the determination value 60 is, for example, "2", the difference value "7" is equal to or greater than the determination value 60, so the motor control is changed. On the other hand, when the first count value is "9" and the second count value is "10", since the difference is "1", when the value of the determination value 60 is, for example, "2", If the difference value "1" is less than the judgment value 60, the motor control will not be changed.

In the motor control circuit 3-2A, even if the waveform of the speed command signal is deformed due to, for example, noise generated from a processor or the like provided around the motor control circuit 3-2A, the relative speed of the speed command signal is Motor control does not need to be changed even if a small change is made, so a motor control device 100-2 with high robustness can be obtained. In addition, in the motor control circuit 3-2A, the motor control can be changed only when the speed command signal changes by a specific value. Therefore, the processing load accompanying the calculation operation in the control circuit 31 is reduced, and the power consumption can be reduced.

In addition, the motor control circuits 3-2 and 3-2A according to the second embodiment of the present invention include a motor rotation speed determination circuit (control circuit 31) that determines the rotation speed of the motor, and switches the motor drive waveform generation in accordance with the rotation speed of the motor. handle. Furthermore, the motor control circuits 3-2 and 3-2A according to Embodiment 2 of the present invention include a speed change detection circuit 20 and detect changes in the speed command signal. In addition, the motor control circuits 3-2 and 3-2A according to Embodiment 2 of the present invention only use hardware to detect changes in the speed command signal and reflect them in the motor control.

(Embodiment 3)

FIG. 23 is a diagram showing the structure of a motor control device according to Embodiment 3. FIG. In the following, the same parts as in Embodiment 1 are assigned the same reference numerals and their descriptions are omitted, and different parts are described. The motor control device 100-3 of the third embodiment includes a motor control circuit 3-3 instead of the motor control circuit 3-1 of the first embodiment. The IC temperature detection part 6A and the bearing bushing are connected to the motor control circuit 3-3. Temperature detection unit 6B.

Next, a structural example of the motor 4 and the structure of the motor control circuit 3-3 will be described with reference to FIGS. 24 and 25. The motor control circuit 3-3 uses the IC temperature detection unit 6A and the bearing lining temperature detection unit 6B to detect detection information for external communication, etc.

FIG. 24 is a diagram showing a structural example of the motor 4 . As shown in Figure 24, the motor 4 series includes a casing 4-1, a bearing bush 4-2, a bearing 4-3, an insulator 4-4, an iron core 4-5, a coil 4-6, and a printed circuit board 4- 7. IC410, IC temperature detection part 6A and bearing lining temperature detection part 6B. A cylindrical bearing bush 4-2 is provided with two bearings 4-3. For convenience of explanation, the IC temperature detection unit 6A is arranged outside the IC 410 in FIG. 24 , but the IC temperature detection unit 6A is built into the IC 410 . The IC temperature detection unit 6A is a circuit component temperature detection unit that detects the internal temperature of the IC 410 (hereinafter referred to as the IC internal temperature) which is an example of a circuit component provided on the printed circuit board 4 - 7 . Since the IC temperature detection unit 6A is built into the IC 410 , no external parts are required for detecting the temperature of the IC 410 , thereby reducing the manufacturing cost of the printed circuit board 4 - 7 , further simplifying the structure of the printed circuit board 4 - 7 and improving reliability. In addition, the IC temperature detection unit 6A may be provided outside the IC 410 to detect the external temperature of the IC 410 .

Fig. 25 is a diagram showing the structure of the motor control circuit according to the third embodiment. The motor control circuit 3-3 is provided with a determination circuit 10A instead of the determination circuit 10. The IC temperature detection unit 6A inputs detection information indicating the value of the detected IC internal temperature to the motor control circuit 3-3.

If poor lubrication of the bearing 4-3 occurs and the sliding friction between the inner ring, the rolling element, and the outer ring of the bearing 4-3 increases, the bearing 4-3 generates heat and the heat is transmitted to the bearing bush 4-2. The bushing temperature detection unit 6B detects the temperature of the bearing bush 4-2 (hereinafter referred to as the bushing temperature) and inputs detection information indicating the value of the detected temperature to the motor control circuit 3-3.

The IC temperature detection part 6A and the bearing lining temperature detection part 6B are each made of, for example, a thermistor, a thermocouple, a silicon band gap temperature sensor, a digital temperature sensor, or any combination thereof. Sensors composed of.

In the judgment information generation circuit 12 of the motor control circuit 3-3, these detection information are converted into judgment information and input to the judgment circuit 10A. Like the above-mentioned determination circuit 10 , the determination circuit 10A determines whether the motor 4 is malfunctioning or degrading based on the determination information generated by the determination information generation circuit 12 , and uses information indicating that the motor 4 is malfunctioning or degrading as an interrupt signal. to be output to the control circuit 11 including arithmetic processing functions.

Next, the operation of the motor control circuit 3-3 will be described with reference to FIGS. 26 and 27 . FIG. 26 is a flowchart for explaining the operation of the motor control circuit according to the third embodiment. In FIG. 26 , the difference from FIG. 4 is that the processing of steps S40 and S41 is performed instead of the processing of step S4 . The respective processes of steps S1, S2, S3, S5, and S6 are the same as those in Embodiment 1, and therefore descriptions thereof are omitted. FIG. 27 is a diagram showing an example of IC internal temperature and bearing lining temperature in Embodiment 3. FIG. The vertical axis of Figure 27 is temperature, and the horizontal axis is time.

In step S3 of FIG. 26 , the determination circuit 10A, which has read the conversion result held by the AD sequencer 9 , determines the relationship between the IC internal temperature and the bearing lining by, for example, subtracting the bearing lining temperature from the IC internal temperature in step S40 . The difference in lining temperature. Furthermore, the determination circuit 10A calculates the first temperature difference between the IC internal temperature and the bearing lining temperature by calculating the absolute value of the difference between the IC internal temperature and the bearing lining temperature.

The determination circuit 10A that calculates the first temperature difference compares the preset first temperature threshold value for temperature determination with the first temperature difference in step S41. The first temperature threshold value is an example of the judgment value 40.

For example, in FIG. 27 , when the IC internal temperature at time t1 after a fixed time has elapsed since the start of power supply to the motor 4 is 50°C, and the bearing bush temperature is 75°C, the first temperature difference is 25°C. . For example, when the first temperature threshold value is 50°C, it is determined that the first temperature difference is lower than the first temperature threshold value (step S41, No). Therefore, in this case, the determination circuit 10A repeats step S1. future processing.

On the other hand, when the bearing bush 4-2 reaches a high temperature due to poor lubrication of the bearing 4-3, etc., the first temperature difference may exceed the first temperature threshold value. Specifically, if the power supply to the motor 4 continues and the IC internal temperature at time t2 after a fixed time has elapsed from time t1 is 50°C, and the bearing bush temperature exceeds 100°C, the first temperature difference exceeds 50°C. . When the first temperature threshold value is 50°C, it is determined that the first temperature difference exceeds the first temperature threshold value (step S41, YES). In this case, the determination circuit 10A performs steps S5 and S6. processing, thereby notifying the outside that an abnormality may have occurred in motor 4.

In addition, in Embodiment 3, the structural example in which the bearing bush temperature and the internal temperature of the IC are compared is explained. However, as long as the temperature at different positions inside the motor 4 can be compared, for example, the detection coil 4-6 may be provided. The temperature detection unit of the temperature detects the temperature of the coil and compares the coil temperature detected by the temperature detection unit with the internal temperature of the IC. In addition, a temperature detection unit that detects the temperature of the core 4 - 5 may be provided, and the core temperature detected by the temperature detection unit may be compared with the IC internal temperature.

According to the motor control device 100-3 of Embodiment 3, a plurality of temperature detection units are used to comparatively detect temperatures at different locations inside the motor 4 which is relatively easy, thereby determining whether the motor 4 is malfunctioning or deteriorating and providing external notification.

In addition, it is configured to compare the bearing lining temperature and the internal temperature of the IC to detect a temperature rise caused by poor lubrication of the bearing 4-3 that deteriorates the earliest in the motor 4. Therefore, it is similar to the case where the temperature of other locations in the motor 4 is used. ratio, it is possible to improve the accuracy of diagnosis of deterioration and the like.

(Embodiment 4)

Fig. 28 is a diagram showing the structure of the motor control device according to the fourth embodiment. Hereinafter, the same parts as in Embodiment 3 are assigned the same reference numerals and their description is omitted, and different parts are described. The motor control device 100-4 of the fourth embodiment includes a motor control circuit 3-4 instead of the motor control circuit 3-3 of the third embodiment. The IC temperature detection part 6A, the bearing bush temperature detection part 6B, and the motor external temperature detection part 6C are connected to the motor control circuit 3-4.

Next, the structure of the motor control circuit 3-4 will be described with reference to FIG. 29. The motor control circuit 3-4 uses the detection signals detected by each of the IC temperature detection unit 6A, the bearing lining temperature detection unit 6B, and the motor external temperature detection unit 6C. Information for external notifications, etc.

Fig. 29 is a diagram showing the structure of the motor control circuit according to the fourth embodiment. The motor external temperature detection unit 6C is provided, for example, in the casing 4-1 of the motor 4 or the like. In addition, the motor external temperature detection part 6C may be fixed to the casing 4-1 via a heat insulating part or the like so as not to be affected by the heat generated by driving the motor 4, or may be provided around the casing 4-1 so as to be able to detect the motor. The outside air temperature is around 4.

The motor external temperature detection unit 6C detects the external air temperature around the casing 4-1, the surface temperature of the casing 4-1, and the like, and inputs detection information indicating the value of the detected temperature as the motor external temperature. to motor control circuit 3-4. The motor external temperature detection unit 6C is, for example, a thermistor, a thermocouple, a silicon bandgap temperature sensor, a digital temperature sensor, or a sensor composed of any combination thereof.

In the judgment information generation circuit 12 of the motor control circuit 3-4, these detection information are converted into judgment information and input to the judgment circuit 10B. Like the above-mentioned determination circuit 10 , the determination circuit 10B determines whether the motor 4 is malfunctioning or degrading based on the determination information generated by the determination information generation circuit 12 , and outputs a signal indicating that the motor 4 is malfunctioning or degrading as an interrupt signal. to the control circuit 11 including arithmetic processing functions.

Next, the operation of the motor control circuit 3-4 will be described with reference to FIGS. 30, 31, and 32.

Fig. 30 is a flowchart for explaining the operation of the motor control circuit according to the fourth embodiment. In FIG. 30 , the difference from FIG. 26 is that processing such as step S42 is performed between the processing of step S41 and step S5 .

31 is a first diagram showing an example of IC internal temperature, bearing lining temperature, motor external temperature, etc. in Embodiment 4. Figure 32 shows the IC internal temperature and bearing lining temperature in Embodiment 4. The second diagram shows an example of temperature, motor external temperature, etc. The vertical axis of FIG. 31 and FIG. 32 represents temperature, and the horizontal axis represents time.

FIG. 31 shows the transition of the bearing lining temperature and the IC internal temperature when the motor external temperature does not change with the elapsed time. In FIG. 31 , the first temperature difference between the bearing bushing temperature and the IC internal temperature at time t2 is larger than the first temperature difference at time t1 .

On the other hand, as shown in FIG. 32 , for example, when the temperature outside the motor rises due to the influence of heat generated by a heat source provided around the motor 4 , the heat is transmitted to the IC 410 via the casing 4 - 1 of the motor 4 . As a result, not only the bearing lining temperature, but also the IC410 temperature gradually increases. Therefore, the first temperature difference between the bearing bushing temperature and the IC internal temperature changes at approximately the same value with respect to the elapsed time. Taking into consideration that when the external temperature of the motor rises, the internal temperature of the IC rises, the flow chart shown in FIG. 30 will be described.

In step S41 of FIG. 30 , when it is determined that the first temperature difference between the IC internal temperature and the bearing lining temperature exceeds the first temperature threshold (step S41 , yes), the motor control circuit 3 - 4 executes step S42 processing.

In step S42, the motor control circuit 3-4 calculates the absolute value of the difference between the bearing lining temperature and the motor external temperature, thereby calculating the second temperature difference between the IC internal temperature and the motor external temperature.

Then, the motor control circuit 3-4 that has calculated the second temperature difference compares the preset second temperature threshold value for temperature determination with the second temperature difference in step S43. The second temperature threshold value is an example of the judgment value 40.

When the second temperature difference is lower than the second temperature threshold value (step S43, No), the motor control circuit 3-4 repeats the processing from step S1 onwards.

When the second temperature difference exceeds the second temperature threshold value (step S43, Yes), the motor control circuit 3-4 performs the processing of steps S5 and S6, thereby notifying the outside that a possible occurrence in the motor 4 Exception.

The processing of steps S42 and S43 will be described in detail.

In FIG. 31 , when the IC internal temperature at time t1 immediately after the power supply to the motor 4 is started is, for example, 30°C, the motor external temperature is 25°C, and the bearing bushing temperature is 50°C, the first temperature difference is 20°C. (=Bearing lining temperature 50℃-IC internal temperature 30℃), the second temperature difference is 5℃ (=IC internal temperature 30℃-Motor external temperature 25℃). When the first temperature threshold is, for example, 30° C., since the first temperature difference is equal to or less than the first temperature threshold, notification to the outside is not performed at time t1.

After that, if the external temperature of the motor does not change and the bearing lining temperature exceeds, for example, 100°C due to an abnormality in the motor 4 at time t2, the first temperature difference exceeds 70°C (= bearing lining temperature 100°C - IC internal temperature 30 ℃) and exceeds the first temperature threshold value, therefore an external notification is performed. In addition, as the bearing lining temperature rises, the IC internal temperature may rise slightly. However, for convenience of explanation in Figure 31, it is assumed that the IC internal temperature is not affected by the bearing lining temperature.

On the other hand, as shown in FIG. 32 , when the temperature outside the motor rises due to the influence of heat generated from the heat source provided around the motor 4 , the temperature inside the IC also rises. In this case, assume that the bearing lining temperature at time t2 exceeds 100°C, the IC internal temperature is 70°C, the motor external temperature is 65°C, and the first temperature threshold is 30°C, due to the first temperature difference system exceeds 30°C, thus exceeding the first temperature threshold.

However, even if the first temperature difference exceeds the first temperature threshold value, for example, assuming that the second temperature threshold value is 10°C, since the second temperature difference is 5°C (= IC internal temperature 70°C - The motor external temperature is 65°C), so it is below the second temperature threshold value. That is, by comparing the second temperature threshold value and the second temperature difference, it can be distinguished whether the increase in the bearing lining temperature is caused by the temperature outside the motor or by a failure of the motor 4 .

According to Embodiment 4, it can be determined whether the increase in the bearing lining temperature is caused by an increase in the temperature outside the motor or by a failure of the motor 4 . Therefore, it is possible to improve the accuracy of determining whether the motor 4 is malfunctioning or deteriorating. Therefore, when the motor 4 does not malfunction or deteriorate, unnecessary external notifications can be suppressed, and the work efficiency of the operator who monitors the external notifications can be improved.

In addition, the structure shown in the above embodiment is an example of the content of the present invention, and may be combined with other known techniques, or part of the structure may be omitted or changed within the scope that does not deviate from the gist of the present invention.

3-1: Motor control circuit

5:Current detection part

6: Temperature detection department

7: Power supply voltage detection part

8:AD converter

9:AD sequencer

10: Determination circuit

11:Control circuit

12: Determination information generation circuit

40: Judgment value

Claims (8)

A motor control circuit including: a control circuit that controls the switching operation of an inverter circuit that supplies AC power to the motor; a determination information generation circuit that generates determination information for determining whether the motor is malfunctioning or deteriorating; and a determination circuit , determines whether the aforementioned motor is malfunctioning or deteriorating based on the aforementioned determination information, and outputs a signal indicating that the aforementioned motor is malfunctioning or deteriorating as an interrupt signal to the aforementioned control circuit; and the notification terminal is connected to the aforementioned determination circuit, and connects the aforementioned motor A malfunction or deterioration is notified to a circuit provided outside the motor control circuit; the judgment circuit compares the value of the judgment information with a preset judgment value and determines that the value of the judgment information is the judgment value. In the above case, the voltage applied to the notification terminal is set to a value different from the voltage applied to the notification terminal when the value of the determination information is smaller than the determination value. The motor control circuit as described in claim 1, wherein the control circuit generates the determination information when detecting failure or degradation of the motor. The motor control circuit as described in claim 1, wherein the motor is provided with: a plurality of temperature detection parts, which detect the temperatures of at least two different positions; and the judgment information generation circuit is an input to indicate the plurality of temperature detection parts. The judgment information is generated based on the detection information of each detected temperature value; the judgment circuit controls the motor when the first temperature difference exceeds the first temperature threshold based on the judgment information corresponding to the detection information. The outside of the circuit notifies that the motor is malfunctioning or deteriorating, and the first temperature difference is used to represent a difference in temperature detected by each of the plurality of temperature detection units. A motor control circuit having: The control circuit controls the switching operation of the inverter circuit that supplies AC power to the motor; the determination information generation circuit generates determination information for determining whether the motor is malfunctioning or deteriorating; the determination circuit determines whether the motor is malfunctioning or deteriorating based on the determination information. Whether the motor is malfunctioning or deteriorating, and a signal indicating that the motor is malfunctioning or deteriorating is output as an interrupt signal to the aforementioned control circuit; the aforementioned motor system is equipped with: a plurality of temperature detection parts, which detect the temperature of at least two different positions; the aforementioned determination The information generation circuit generates the determination information by inputting detection information indicating the value of the temperature detected by each of the plurality of temperature detection units; the determination circuit generates the determination information in the first step based on the determination information corresponding to the detection information. When the temperature difference exceeds the first temperature threshold value, a malfunction or deterioration of the motor is notified to the outside of the motor control circuit. The first temperature difference is used to represent the difference in temperature detected by each of the plurality of temperature detection parts. value. The motor control circuit according to claim 4, wherein the plurality of temperature detection units are circuit component temperature detection units and bearing lining temperature detection units, and the circuit component temperature detection unit detects the temperature of circuit components provided on the printed circuit board, The printed circuit board is provided in the motor, and the bearing bush temperature detection unit detects the temperature of the bearing bush provided in the motor. The motor control circuit as described in claim 5, wherein the determination circuit determines whether the first temperature difference exceeds the first temperature threshold and the second temperature difference exceeds the second temperature threshold. An external notification indicates that the motor is malfunctioning or deteriorating, and the second temperature difference represents the difference between the temperature of the circuit component and the external temperature of the motor. A motor control device having: The motor control circuit described in any one of claims 1 to 6; the inverter circuit; and the drive signal generation circuit are configured to generate, based on the pulse width modulation signal used to control the switching operation, the inverter circuit. The driving signal for the operation of the switching elements of the inverter circuit. A motor control circuit including: a control circuit that controls the switching operation of an inverter circuit that supplies AC power to the motor; a determination information generation circuit that generates determination information for determining whether the motor is malfunctioning or deteriorating; and a determination circuit , determines whether the aforementioned motor is malfunctioning or deteriorating based on the aforementioned determination information, and outputs a signal indicating that the aforementioned motor is malfunctioning or deteriorating to the aforementioned control circuit; and the notification terminal is connected to the aforementioned determination circuit, and outputs a signal indicating that the aforementioned motor is malfunctioning or deteriorating. The deterioration is notified to a circuit provided outside the motor control circuit; and when the judgment circuit compares the value of the judgment information with a preset judgment value and the result is that the value of the judgment information is greater than or equal to the judgment value, The voltage applied to the notification terminal is set to a value different from the voltage applied to the notification terminal when the value of the determination information is smaller than the determination value.

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