JP2022059935A - Electric angle estimation device, motor, vacuum cleaner, and electric angle estimation method - Google Patents

Abstract

To provide a motor control device that easily estimates an electric angle of a rotor immediately after motor operation is stopped and rotation by inertia is started.SOLUTION: An electric angle estimation device includes a first electric angle estimation unit 21 that estimates an electric angle as an estimated electric angle θe during motor operation in which the state of energizing one or more coils and the electric angle of a rotor are correlated and a second electric angle estimation unit 22 that estimates an electric angle after motor operation has been stopped as an estimated electric angle on the basis of the rotation speed of the rotor immediately before the operation is stopped.SELECTED DRAWING: Figure 2

Description

The present invention relates to an electric angle estimation device for estimating an electric angle of a motor, a motor, a vacuum cleaner, and an electric angle estimation method.

As a conventional electric angle detecting device, based on a detecting means for detecting the behavior of the current flowing in each of the polyphase windings by the voltage applied by the voltage applying means and a behavior of the current of each winding detected by the detecting means. , An electric angle detecting device including an electric angle calculating means for obtaining an electric angle of a motor between 0 and 2π by referring to the relationship stored in the storage means is known (see Patent Document 1).

Japanese Patent Application Laid-Open No. 09-238495

However, in the conventional electric angle detecting device, it is difficult to estimate the electric angle of the rotor immediately after the motor operation is stopped and the rotation due to inertia is started.

An object of the present invention is to provide an electric angle estimator, a motor, a vacuum cleaner, and an electric angle estimation method that can easily estimate the electric angle of a rotor immediately after the motor operation is stopped and rotation due to inertia is started. It is to be.

The electric angle estimation device according to an example of the present invention estimates the electric angle as an estimated electric angle while the motor has a correlation between the energized state of one or a plurality of coils and the electric angle of the rotor. The second electric angle estimation unit that estimates the electric angle estimation unit and the electric angle after the motor operation is stopped as the estimated electric angle based on the rotation speed of the rotor immediately before the operation is stopped. And prepare.

Further, the motor according to an example of the present invention includes the above-mentioned electric angle estimation device.

Further, the vacuum cleaner according to an example of the present invention includes the above-mentioned motor.

Further, in the electric angle estimation method according to an example of the present invention, (a) the electric angle is estimated while the motor has a correlation between the energized state of one or a plurality of coils and the electric angle of the rotor. (B) The electric angle after the operation of the motor is stopped is estimated as the estimated electric angle based on the rotation speed of the rotor immediately before the operation is stopped.

An electric angle estimation device, a motor, a vacuum cleaner, and an electric angle estimation method having such a configuration make it easy to estimate the electric angle of the rotor immediately after the operation of the motor is stopped and the rotation due to inertia is started. ..

It is a block diagram which shows an example of the electric structure of the motor which concerns on one Embodiment of this invention. It is a flowchart which shows an example of the operation of the electric angle estimation apparatus which uses the electric angle estimation method which concerns on one Embodiment of this invention. It is a flowchart which shows an example of the operation of an electric angle signal output part. It is a flowchart which shows an example of the operation of an electric angle signal output part. It is a flowchart which shows an example of the operation of an electric angle signal output part. It is a flowchart which shows an example of the operation of an electric angle signal output part. It is a flowchart which shows an example of the operation of an electric angle signal output part. It is a signal waveform diagram which shows an example of a coil voltage Vu, an estimated electric angle θe, and an electric angle signal FG. It is a waveform diagram which shows enlarged before and after the timing Turn when the operation in a positive direction was stopped. It is a waveform diagram which shows enlarged before and after the timing Turn when the operation in the reverse direction was stopped. It is a waveform diagram which enlarges and shows the timing Turn before and after when the rotation of a rotor is greatly decelerated after the operation of a forward rotation is stopped. It is a waveform diagram which enlarges and shows the timing Turn before and after when the rotation of a rotor is greatly decelerated after the operation of reverse rotation is stopped. It is a waveform diagram which enlarges and shows the timing Turn before and after when the rotation of a rotor is greatly decelerated after the operation of reverse rotation is stopped. It is a waveform diagram which enlarges and shows the timing Turn before and after when the rotation of a rotor is greatly decelerated after the operation of a forward rotation is stopped. It is a perspective view which shows an example of the vacuum cleaner provided with the motor shown in FIG.

Hereinafter, embodiments according to the present invention will be described with reference to the drawings. It should be noted that the configurations with the same reference numerals in the respective figures indicate that they are the same configurations, and the description thereof will be omitted. FIG. 1 is a block diagram showing an example of an electrical configuration of a motor according to an embodiment of the present invention. The motor 1 shown in FIG. 1 includes an electric angle estimation device 2 and a stator 3. The motor 1 further includes an inverter circuit 4.

The stator 3 includes coils Lu, Lv, Lw. One end of the coils Lu, Lv, Lw is connected to each other, and the other end is connected to the inverter circuit 4.

The inverter circuit 4 controls the energization state of the coils Lu, Lv, and Lw according to the control signal from the electric angle estimation device 2. Specifically, the inverter circuit 4 is configured by connecting a series circuit of the switching elements Qu1 and Qu2, a series circuit of the switching elements Qv1 and Qv2, and a series circuit of the switching elements Qw1 and Qw2 in parallel.

The source of the switching element Qu1 and the drain of the switching element Qu2 are connected to the U-phase coil Lu. The source of the switching element Qv1 and the drain of the switching element Qv2 are connected to the V-phase coil Lv. The source of the switching element Qw1 and the drain of the switching element Qw2 are connected to the W-phase coil Lw. The drains of the switching elements Qu1, Qv1 and Qw1 are connected to the power supply + V for driving the motor, and the sources of the switching elements Qu2, Qv2 and Qw2 are connected to the ground GND.

The anodes of the diodes Du1, Dv1, Dw1, Du2, Dv2, Dw2 are connected to the source of the switching elements Qu1, Qv1, Qw1, Qu2, Qv2, Qw2, and the drains of the switching elements Qu1, Qv1, Qw1, Qu2, Qv2, Qw2. The cathodes of the diodes Du1, Dv1, Dw1, Du2, Dv2, and Dw2 are connected to the diode.

Hereinafter, the switching elements Qu1, Qv1, Qw1, Qu2, Qv2, and Qw2 may be collectively referred to as a switching element Q, and the diodes Du1, Dv1, Dw1, Du2, Dv2, and Dw2 may be collectively referred to as a diode D.

The diodes Du1 and Du2 bypass the switching elements Qu1 and Qu2 when a counter electromotive force is generated in the coil Lu, and the diodes Dv1 and Dv2 bypass the switching elements Qv1 and Qv2 when a counter electromotive force is generated in the coil Lv. , Dw2 bypasses the switching elements Qw1 and Qw2 when a counter electromotive force is generated in the coil Lw, so that the respective return currents flow.

The gate of each switching element Q is connected to the electric angle estimation device 2. Thereby, the electric angle estimation device 2 can control the presence / absence of energization of the coils Lu, Lv, Lw and the direction of the current, that is, the energized state by controlling the on / off of each switching element Q.

As the switching element Q, various switching elements such as MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor), IGBT (Insulated Gate Bipolar Transistor), and bipolar transistor can be used.

Hereinafter, the electric angle estimation device 2 controls the energized state of the coils Lu, Lv, Lw by controlling the inverter circuit 4, and the electric angle estimation device 2 or its constituent elements simply control the coils Lu, Lv. , Lw may be described as controlling the energized state.

The electric angle estimation device 2 is, for example, a CPU (Central Processing Unit) that executes predetermined arithmetic processing, a RAM (Random Access Memory) that temporarily stores data, a non-volatile storage unit 26 such as a flash memory, and a voltage detection. It includes a circuit 27, a timer circuit, and peripheral circuits thereof. The electric angle estimation device 2 functions as a first electric angle estimation unit 21 and a second electric angle estimation unit 22 by executing a control program stored in advance in the storage unit 26, for example. The electric angle estimation device 2 preferably further functions as a third electric angle estimation unit 23, more preferably functions as an electric angle signal output unit 24, and further preferably functions as a motor control unit 25.

In the present embodiment, the first electric angle estimation unit 21 and the second electric angle estimation unit 22 are composed of a single element. Thereby, a single element can estimate the electric angle of the rotor while the motor 1 is in operation and the electric angle of the rotor after the operation of the motor 1 is stopped. Further, in the present embodiment, the first electric angle estimation unit 21, the second electric angle estimation unit 22, and the third electric angle estimation unit 23 are composed of a single element. Thereby, by a single element, the electric angle of the rotor while the motor 1 is operating, the electric angle of the rotor after the operation of the motor 1 is stopped, and the electric angle of the rotor after the switching condition is satisfied. , Can be estimated. The first electric angle estimation unit 21, the second electric angle estimation unit 22, the third electric angle estimation unit 23, the electric angle signal output unit 24, and the motor control unit 25 are single units such as an IC (Integrated Circuit). It may be composed of the elements of the above, or may be distributed and arranged in a plurality of elements.

The voltage detection circuit 27 detects the coil voltages Vu, Vv, Vw of the coils Lu, Lv, Lw. The voltage detection circuit 27 may be connected to the coils Lu, Lv, Lw via a filter, a protection circuit, or the like (not shown). The voltage detection circuit 27 detects the voltage applied to the coils Lu, Lv, Lw by the inverter circuit 4 as the coil voltages Vu, Vv, Vw during the operation period of the motor 1, and the coil Lu during the operation stop period of the motor 1. , Lv, Lw induced voltage is detected as coil voltage Vu, Vv, Vw.

In the motor 1, the state of energization of one or a plurality of coils and the electric angle of the rotor have a correlation. The motor 1 is, for example, a brushless motor. As the motor 1, a brushless DC motor can be preferably used. Further, the number of poles of the motor 1 is not limited. For example, when the motor 1 has two poles, the electric angle estimated by the electric angle estimation device 2 and the mechanical angle of the rotor match.

Brushless motors cannot mechanically turn the coil current with a brush. Therefore, in order to rotate the brushless motor, it is necessary to grasp the rotation position of the magnetic pole of the rotor on the control circuit side that controls the rotation of the motor, and to pass a current to an appropriate coil according to the position of the magnetic pole of the rotor. .. Then, the rotational position of the rotor that has started operation changes according to the current supplied to the coil by the control of the control circuit. That is, the brushless motor is a motor in which the energization state of the coil and the electric angle of the rotor have a correlation.

Therefore, during the period in which the brushless motor is operated, the control circuit of the motor controls the energization state of the coil while grasping the electric angle which is the electric rotation position of the magnetic pole of the rotor.

On the other hand, when the operation of the brushless motor is stopped and the rotor rotates due to inertia, the position of the magnetic pole moves. In order to start the operation again, it is necessary to grasp the electric angle of the rotor indicating the electric position of the magnetic pole at the start of the operation.

The motor 1 is not limited to the brushless motor. The electric angle estimation device 2 can be applied as long as the motor has a correlation between the energized state of the coil and the electric angle of the rotor.

The first electric angle estimation unit 21 estimates the electric angle of the rotor as the estimated electric angle θe while the motor is in operation. As described above, the electric angle of the rotor during the period in which the motor 1 having a correlation between the energized state of the coil and the electric angle of the rotor is operated is on the control circuit side, that is, on the first electric angle estimation unit 21 side. Can be grasped by. In this way, the first electric angle estimation unit 21 estimates the electric angle grasped by the operation control of the motor 1 as the estimated electric angle θe.

The first electric angle estimation unit 21 uses the estimated electric angle θe during the operation period as the voltage of the coils Lu, Lv, Lw detected by the voltage detection circuit 27, and / or the current flowing through the coils Lu, Lv, Lw. It may be estimated based on.

The second electric angle estimation unit 22 and the third electric angle estimation unit 23 estimate the electric angle of the rotor of the motor 1 which is stopped.

Specifically, the second electric angle estimation unit 22 estimates the electric angle after the operation of the motor 1 is stopped as the estimated electric angle θe based on the rotation speed of the rotor immediately before the operation is stopped. As a result, the electric angle of the rotor can be estimated with high accuracy even after the operation of the motor 1 is stopped.

The third electric angle estimation unit 23 is induced to at least one of the coils Lu, Lv, and Lw after the preset switching conditions are satisfied during the estimation period of the electric angle θe by the second electric angle estimation unit 22. The electric angle is estimated as the estimated electric angle θe based on the voltage to be applied. In general, as the induced voltage, a voltage induced in at least one of one or a plurality of coils may be used. As a result, the electric angle of the rotor after the preset switching condition is satisfied can be estimated with higher accuracy.

The motor control unit 25 energizes the coil of the motor 1 based on the estimated electric angle θe estimated by the first electric angle estimation unit 21, the second electric angle estimation unit 22, and the third electric angle estimation unit 23. To control. That is, the motor control unit 25 controls the energization state of the coils Lu, Lv, and Lw based on the estimated electric angle θe. As a result, the motor control unit 25 can control the energized state based on the estimated electric angle θe. The electric angle estimation device 2 does not have to include the motor control unit 25. Further, the estimated electric angle θe is not limited to the example used for the drive control of the motor.

Further, the estimated electric angle θe is not used for the drive control of the motor, and the first electric angle estimation unit 21 uses the electric angle of the rotor during the operation period to detect the voltage of the coils Lu, Lv, Lw detected by the voltage detection circuit 27. And / or the configuration is such that estimation is performed based on the current flowing through the coils Lu, Lv, and Lw, and the electric angle estimation device 2 may be used instead of the sensor that detects the electric angle of the motor.

The electric angle signal output unit 24 sets the preset reference angle θo to 0 degrees in the estimated electric angle θe, a positive sign in the range of 180 degrees in one direction from the reference angle θo, and 180 degrees in the other direction from the reference angle θo. When the range of is represented by a negative sign and the estimated electric angle θe is a positive value exceeding 0 degrees and 180 degrees or less, the electric angle signal FG representing the estimated electric angle θe is set to a high level ( First level). In addition, +180 degrees and −180 degrees represent the same electric angle.

Further, in the electric angle signal output unit 24, the estimated electric angle θe is 0 degrees or less and is on the plus side of −180 degrees, that is, the estimated electric angle θe is 0 degrees or the absolute value is a negative value less than 180 degrees. When there is, the electric angle signal FG is set to the low level (second level).

That is, in the present embodiment, the case where the estimated electric angle θe is 0 degrees or more and less than 180 degrees is the high level (first level), and the case where the estimated electric angle θe is −180 degrees or more and less than 0 degrees is the low level (1st level). Second level). The case where the estimated electric angle θe is 0 degrees or more and less than 180 degrees may be the low level, and the case where the estimated electric angle θe is −180 degrees or more and less than 0 degrees may be the high level. Further, the case where the estimated electric angle θe is larger than 0 degrees and 180 degrees or less may be the first level, and the case where the estimated electric angle θe is larger than −180 degrees and 0 degrees or less may be the second level. That is, the electric angle signal output unit 24 sets the preset reference angle θo to 0 degrees in the estimated electric angle θe, a positive sign in the range of 180 degrees in one direction from the reference angle θo, and the reference angle θo in the other direction. When the range of 180 degrees is represented by a negative sign and the estimated electric angle θe is a positive value less than 180 degrees, the signal level of the electric angle signal FG representing the estimated electric angle θe is set to the first level. When the estimated electric angle θe is a negative value whose absolute value is less than 180 degrees, the signal level of the electric angle signal FG is set to a second level different from the first level.

Further, the estimated electric angle θe may be applied to −180 degrees to 0 degrees to +180 degrees, and may be processed at, for example, 0 degrees to 360 degrees. Further, the first level may be a low level and the second level may be a high level.

FIG. 2 is a flowchart showing an example of the operation of the electric angle estimation device 2 using the electric angle estimation method according to the embodiment of the present invention. 3 to 7 are flowcharts showing an example of the operation of the electric angle signal output unit 24. Steps S1 to S8 shown in FIG. 2 and steps S11 to S53 shown in FIGS. 3 to 7 are executed in parallel. First, steps S1 to S8 will be described.

First, while the motor 1 is in operation, the first electric angle estimation unit 21 estimates the estimated electric angle θe (step S1: (a)).

Next, the motor control unit 25 controls the energization state of the coils Lu, Lv, and Lw based on the estimated electric angle θe estimated by the first electric angle estimation unit 21 (step S2).

FIG. 8 is a signal waveform diagram showing an example of the coil voltage Vu, the estimated electric angle θe, and the electric angle signal FG. The horizontal axis of FIG. 8 is time t. The estimated electric angle θe is usually processed by a digital value, but is represented by a waveform diagram in FIG. 8 for the sake of explanation.

The estimated electric angle θe estimated by the first electric angle estimation unit 21 in step S1 during the operating period shown in FIG. 8 is shown. In this case, the inclination direction of the waveform of the estimated electric angle θe represents the rotation direction of the motor 1. As shown in FIG. 8, if the inclination from the lower left to the upper right is a forward rotation, the inclination from the upper left to the lower right represents a reverse rotation. Further, the degree of inclination of the waveform of the estimated electric angle θe indicates the rotation speed of the rotor. Specifically, the larger the inclination, the faster the rotation speed.

The motor control unit 25 shows an example of controlling the energized state of the coils Lu, Lv, and Lw by PWM (Pulse Width Modulation) during operation. In the coil voltage Vu of FIG. 8, for convenience, the width of the PWM pulse is represented by the density of the line. The coil voltages Vu, Vv, and Vw have different phases depending on the electric angle of the rotor. The description of the coil voltages Vv and Vw is omitted.

Steps S1 and S2 are repeated during the period during which the operation is continued (NO in step S3). Then, when the operation is stopped (YES in step S3: Timing Off), the main body for estimating the estimated electric angle θe is switched from the first electric angle estimation unit 21 to the second electric angle estimation unit 22. Then, the second electric angle estimation unit 22 estimates the estimated electric angle θe based on the rotation speed of the rotor immediately before the operation is stopped (step S4).

As the rotation speed of the rotor immediately before the stop of operation, for example, the control value of the rotation speed of the motor control unit 25 immediately before the stop of operation can be used. Alternatively, as shown by the slope of the estimated electric angle θe shown in FIG. 8, the rotation speed may be calculated from the amount of change in the estimated electric angle θe per unit time immediately before the operation is stopped.

After the timing turn off, the motor control unit 25 does not control the drive of the motor 1, so that the estimated electric angle θe cannot be estimated based on the control value of the motor control unit 25.

Immediately after the timing turn is turned off, the current flowing through the coils Lu, Lv, and Lw is cut off, so that a counter electromotive force is generated in the coils Lu, Lv, and Lw, and a reflux current flows through the diode D. Therefore, the electric angle is not reflected in the coil voltages Vu, Vv, and Vw detected by the voltage detection circuit 27. Therefore, it is difficult to estimate the estimated electric angle θe based on the coil voltages Vu, Vv, Vw and the coil current.

On the other hand, since the second electric angle estimation unit 22 estimates the estimated electric angle θe based on the rotation speed of the rotor immediately before the operation is stopped, even when a counter electromotive force is generated in the coils Lu, Lv, and Lw, the second electric angle estimation unit 22 estimates the estimated electric angle θe. The estimated electric angle θe after the operation is stopped can be estimated.

As described above, the electric angle estimation device 2 provided with the second electric angle estimation unit 22 can easily estimate the electric angle of the rotor immediately after the operation of the motor 1 is stopped and the rotation due to the inertia is started.

9 and 10 are waveform diagrams showing enlarged images before and after the timing Turn when the operation is stopped. The waveform G1 shows the estimated electric angle θe by the first electric angle estimation unit 21, the waveform G2 shows the estimated electric angle θe by the second electric angle estimation unit 22, and the waveform G3 shows the estimated electric angle θe by the third electric angle estimation unit 23. Indicates θe. FIG. 9 shows forward rotation, and FIG. 10 shows reverse rotation.

The waveform G2 shown in FIGS. 9 and 10 is estimated after the operation is stopped by the second electric angle estimation unit 22 assuming that the rotation speed of the rotor immediately before the operation stop is equal to the rotation speed of the rotor after the operation stop. An example of estimating the electric angle θe as the waveform G2 is shown. That is, the inclination angles of the waveform G1 and the waveform G2 are equal. That is, the second electric angle estimation unit 22 estimates the estimated electric angle θe after the operation is stopped, assuming that the rotation speed of the rotor after the operation is stopped is equal to the rotation speed immediately before the stop. Thereby, the estimated electric angle θe after the operation is stopped can be estimated by a simple configuration.

After the operation is stopped, the motor 1 rotates due to inertia and decelerates slightly, but maintains substantially the same speed for a certain period of time. In particular, when the third electric angle estimation unit 23 is provided, the second electric angle estimation unit 22 may estimate the estimated electric angle θe for several tens of microseconds when the counter electromotive force is generated in the coils Lu, Lv, and Lw. After that, it is possible to switch to the estimation by the third electric angle estimation unit 23. In this case, the deceleration that occurs in a few tens of microseconds is often negligible for practical use.

Therefore, the second electric angle estimation unit 22 estimates the estimated electric angle θe after the operation is stopped, assuming that the rotation speed of the rotor immediately before the operation stop is equal to the rotation speed of the rotor after the operation stop. The estimated electric angle θe (waveform G2) after the operation is stopped can be easily estimated.

The second electric angle estimation unit 22 is limited to an example in which the estimated electric angle θe after the operation is stopped is estimated assuming that the rotation speed of the rotor immediately before the operation is stopped is equal to the rotation speed of the rotor after the operation is stopped. not. In some cases, it is desirable to have an estimated electric angle θe in consideration of the deceleration of the motor 1 after the timing Turn.

Therefore, for example, the negative acceleration (deceleration) of the motor 1 when the operation is stopped may be experimentally obtained in advance and stored in the storage unit 26. That is, the electric angle estimation device 2 further includes a storage unit 26 that stores in advance a negative acceleration when the operation is stopped. Then, the second electric angle estimation unit 22 estimates the electric angle after the operation is stopped based on the rotation speed immediately before the operation is stopped (timing Turn) and the negative acceleration stored in the storage unit 26. θe may be estimated. That is, the second electric angle estimation unit 22 may estimate the electric angle after the operation is stopped as the estimated electric angle θe based on the rotation speed immediately before the stop and the negative acceleration.

By doing so, it is possible to improve the estimation accuracy of the estimated electric angle θe after the operation is stopped.

Further, when the load of the object to be driven by the motor 1 is large, the deceleration of the motor 1 after the operation is stopped becomes large. Therefore, the following may be performed.

That is, it further includes a coil current detecting unit that detects a coil current flowing through at least one of the coils Lu, Lv, and Lw. The second electric angle estimation unit 22 estimates the load of the motor 1 based on the coil current detected by the coil current detection unit immediately before the operation is stopped. The second electric angle estimation unit 22 estimates the negative acceleration so that the deceleration increases as the estimated load increases. The second electric angle estimation unit 22 estimates the estimated electric angle θe after the operation is stopped based on the negative acceleration thus estimated and the rotation speed immediately before the operation is stopped. good.

As a method for estimating the negative acceleration from the coil current by the second electric angle estimation unit 22, for example, the correlation between the coil current obtained experimentally in advance and the negative acceleration is represented by a function or a look-up table. It is stored in the storage unit 26. The second electric angle estimation unit 22 can estimate the negative acceleration from the coil current using this function or the look-up table.

By doing so, even when the load of the motor 1 changes, the estimation accuracy of the estimated electric angle θe after the operation is stopped can be improved.

Next, the third electric angle estimation unit 23 is after the switching condition preset during the estimation period of the estimated electric angle θe by the second electric angle estimation unit 22 is satisfied (YES in step S5: timing T2). The estimated electrical angle θe is estimated based on at least one of the one or a plurality of coils, for example, the coil voltage Vu induced in the coil Lu (step S6).

After the switching condition for determining that the counter electromotive force after the operation is stopped is satisfied, the effect of the counter electromotive force is eliminated by switching to the estimation by the third electric angle estimation unit 23. However, the estimated electric angle θe can be estimated based on the coil voltage Vu induced in the coil Lu corresponding to the actual rotation position (electrical angle) of the rotor. As a result, the estimation accuracy of the estimated electric angle θe is improved.

The third electric angle estimation unit 23 may estimate the estimated electric angle θe based on the coil voltage Vv or the coil voltage Vw. Alternatively, the third electric angle estimation unit 23 may estimate the estimated electric angle θe by comprehensively using the coil voltages Vu, Vv, and Vw.

In step S5, as a switching condition, it is exemplified that a preset switching time ts elapses from the time when the operation is stopped.

The counter electromotive force after the operation is stopped disappears or decreases over time. Therefore, for example, the time required for the counter electromotive force to disappear or decrease to a negligible degree is experimentally obtained in advance and stored in the storage unit 26 as the switching time ts. The third electric angle estimation unit 23 uses the second electric angle estimation unit 22 to estimate the estimated electric angle θe when the switching time ts has elapsed since the operation was stopped (YES in step S5: timing T2). Switch to the third electric angle estimation unit 23.

By doing so, the estimated electric angle θe can be estimated based on the coil voltage Vu induced in the coil Lu corresponding to the actual rotation position (electrical angle) of the rotor while eliminating the influence of the counter electromotive force. Can be done. As a result, the estimation accuracy of the estimated electric angle θe is improved. When the switching time ts has not elapsed since the operation was stopped (NO in step S5), the process may proceed to step S4 again.

The switching condition is not limited to the lapse of the switching time ts from the time when the operation is stopped. For example, for at least one coil, for example, coil Lu, the switching condition in step S5 may be that the reflux current flowing due to the counter electromotive force generated by the stop of operation is lower than the preset switching threshold value. That is, the switching condition may be that the reflux current flowing due to the counter electromotive force generated in at least one coil due to the stop of operation is lower than the preset switching threshold value.

For example, when the coil Lu is targeted, the switching element Qu1 may be turned on and the switching element Qu2 may be turned off, or the switching element Qu1 may be turned off and the switching element Qu2 may be turned on depending on the energized state of the coil Lu.

When the switching element Qu1 is turned on and the switching element Qu2 is turned off immediately before the operation is stopped, the current supplied from the power supply + V flows into the coil Lu via the switching element Qu1. When the operation is stopped in this state and the switching element Qu1 is turned off, the back electromotive force of the coil Lu causes a reflux current flowing from the ground GND to the coil Lu via the diode Du2 to flow.

On the other hand, when the switching element Qu1 is turned off and the switching element Qu2 is turned on immediately before the operation is stopped, the current flowing out of the coil Lu flows to the ground GND via the switching element Qu2. When the operation is stopped in this state and the switching element Qu2 is turned off, the reflux current flowing out of the coil Lu flows to the power supply + V via the diode Du1 due to the back electromotive force of the coil Lu.

Therefore, a current detection circuit for detecting the current flowing through the diodes Du1 and Du2 is provided. Then, the reflux current when the counter electromotive force after the operation is stopped becomes negligibly small is obtained in advance, for example, experimentally, and stored in the storage unit 26 as a switching threshold value.

Then, in step S5, when the current flowing through the diodes Du1 and Du2 falls below the switching threshold value (YES in step S5), the process may be shifted to step S6.

By doing so, it is possible to estimate the estimated electric angle θe based on the coil voltage Vu in step S6 after confirming by actual measurement that the counter electromotive force after the operation is stopped has become negligibly small. As a result, the certainty that the estimated electric angle θe can be estimated with high accuracy is increased.

Next, when the operation of the motor 1 is started (YES in step S7), the motor control unit 25 moves to the coils Lu, Lv, Lw based on the estimated electric angle θe estimated by the third electric angle estimation unit 23. The energization control of (step S8) is started (step S8), and the process shifts to step S1 again. When the operation of the motor 1 has not been started (NO in step S7), the process may proceed to step S6 again.

As described above, according to steps S3 to S8, the estimated electric angle θe is estimated by the second electric angle estimation unit 22 and the third electric angle estimation unit 23 even when the operation is stopped, so that the operation is restarted. At this time, the motor control unit 25 can start appropriate energization control based on the estimated electric angle θe.

Next, the operation of the electric angle signal output unit 24 will be described. The electric angle signal output unit 24 operates in parallel with steps S1 to S8 to execute the following operations.

First, the electric angle signal output unit 24 acquires the latest estimated electric angle θe as the immediately preceding electric angle θp (step S11). Next, the electric angle signal output unit 24 newly acquires the latest estimated electric angle θe (step S12). Steps S11 and S12 correspond to so-called sampling processing, and the interval between steps S11 and S12 and the interval at which step S12 is repeated correspond to the sampling interval. In the following processing, the estimated electric angle θe acquired in step S12 is used.

Next, the electric angle signal output unit 24 compares the estimated electric angle θe with 0 degrees (step S13), and when the estimated electric angle θe is 0 degrees or more (YES in step S13), sets the immediately preceding electric angle θp to 0 degrees. (Step S14). If the immediately preceding electric angle θp is less than 0 degrees (YES in step S14), the process proceeds to step S15.

YES in step S13 and YES in step S14 mean that the estimated electric angle θe has changed from minus to plus across 0 degrees or from minus to 0 degrees.

In step S15, the electric angle signal output unit 24 confirms the presence or absence of angle inversion (step S15). The angle inversion means that the estimated electric angle θe changes from +180 degrees to −180 degrees, or from −180 degrees to +180 degrees, and means the timing Tr in FIGS. 9 and 10.

The method for confirming the presence or absence of angle inversion is not particularly limited. For example, within the time of the sampling interval, a predetermined determination angle, for example, 260 degrees, is set in advance as an electric angle having a magnitude that cannot be changed by a rotational motion other than angle inversion. Then, when | θp−θe | exceeds the determination angle and the signs of the estimated electric angle θe and the immediately preceding electric angle θp are inverted, it can be determined that the angle is inverted.

When the angle is inverted (YES in step S15), the electric angle signal output unit 24 confirms whether or not the rotation control direction by the motor control unit 25 is reverse rotation (step S16). If it is reverse rotation (YES in step S16), it corresponds to the timing Tr in FIG. 10 showing the reverse rotation, so that the electric angle signal output unit 24 sets the electric angle signal FG to a high level (step S17: timing Tr). , The process shifts to step S19.

On the other hand, if the rotation is forward (NO in step S16), the signal level of the electric angle signal FG is maintained as it is. That is, the electric angle signal FG is output at the same low level as immediately before the timing T2 when the estimation by the second electric angle estimation unit 22 is switched to the estimation by the third electric angle estimation unit 23.

Here, YES in step S13 and YES in step S14 mean that the estimated electric angle θe has changed from minus to plus across 0 degrees or from minus to 0 degrees, and further angle inversion is present. In the case of (YES in step S15), if the rotation is forward as shown in FIG. 9, the timing Tr of the angle inversion changes from plus to minus over 0 degrees, and therefore, normally, reverse rotation (YES in step S16). It should be YES) in step S16. Here, the forward rotation (NO in step S16) occurs in the following cases.

FIG. 11 is an enlarged waveform diagram showing before and after the timing Turn when the rotation of the rotor is greatly decelerated after the operation of the forward rotation is stopped. When the timing Tr of the angle inversion based on the waveform G2 is located immediately after the timing Stop when the operation is stopped, the estimated electric angle θe falls below 0 degrees in the timing Tr, and the electric angle signal FG becomes a low level.

After that, at timing T2, the estimation is switched to the estimation by the third electric angle estimation unit 23. At this time, since the actual rotation of the rotor is slower than the waveform G2, the estimated electric angle θe of the third electric angle estimation unit 23 shown by the waveform G3 is still 0 degrees or more as shown in the timing T2 of FIG. In this case, when the immediately preceding electric angle θp and the estimated electric angle θe are acquired before and after the timing T2, the immediately preceding electric angle θp becomes negative and the estimated electric angle θe becomes positive. In this case, YES is satisfied in steps S13, S14, and S15, and NO (forward rotation) is satisfied in step S16.

In this case, if steps S16 and S18 are not executed and the process shifts to step S17 when YES in step S15, the electric angle signal FG is displayed as shown by the waveform G4 shown by the alternate long and short dash line in FIG. Signal cracking will occur. When a signal crack such as the waveform G4 occurs in the electric angle signal FG, there is a possibility that an external circuit or an external device that uses the electric angle signal FG externally cannot correctly recognize the electric angle of the motor 1.

Therefore, the change in the estimated electric angle θe immediately after the timing T2 when the estimation by the second electric angle estimation unit 22 is switched to the estimation by the third electric angle estimation unit 23 is in the direction opposite to the rotation direction of the rotor immediately before the timing T2. When corresponding to the rotation direction (YES in steps S13 and S14, NO in step S16), the electric angle signal FG is output at the same low level as immediately before switching (step S18). That is, in the electric angle signal output unit 24, the change in the estimated electric angle θe immediately after switching from the estimation by the second electric angle estimation unit 22 to the estimation by the third electric angle estimation unit 23 is the rotation direction of the rotor immediately before the switching. Outputs the electrical angle signal FG at the same signal level as immediately before switching when corresponding to the rotation direction in the opposite direction.

Therefore, the electric angle signal output unit 24 can prevent the signal cracking of the electric angle signal FG as described above by executing steps S13 to S18.

Next, in step S19, the estimated electric angle θe is set to a new immediately preceding electric angle θp (step S19), and the processing after step S12 is repeated again.

On the other hand, in step S15, when there is no angle inversion (NO in step S15), the process shifts to step S21 (FIG. 4). When there is no angle inversion (NO in step S15), it means that the estimated electric angle θe changes in a slope shape from minus to plus.

Next, in step S21, the electric angle signal output unit 24 confirms whether or not the rotation control direction by the motor control unit 25 is forward rotation (step S21). If it is a forward rotation (YES in step S21), it corresponds to the timing T1 in FIG. 9 showing the forward rotation. Therefore, the electric angle signal output unit 24 sets the electric angle signal FG to a high level (step S22: timing T1). , The process shifts to step S19.

On the other hand, in the case of reverse rotation (NO in step S21), the signal level of the electric angle signal FG is maintained as it is (step S23). That is, the electric angle signal FG is output at the same low level as immediately before the timing T2 when the estimation by the second electric angle estimation unit 22 is switched to the estimation by the third electric angle estimation unit 23.

Here, YES in steps S13 and S14 means that the estimated electric angle θe has changed from minus to plus over 0 degrees or from minus to 0 degrees, and there is no angle reversal (moreover). NO in step S15), and if the reverse rotation is shown in FIG. 10, the timing T1 changes from plus to minus across 0 degrees. Therefore, in step S21, it is usually forward rotation (YES in step S21). Should be. Here, the reverse rotation (NO in step S21) occurs in the following cases.

FIG. 12 is an enlarged waveform diagram showing before and after the timing Turn when the rotation of the rotor is greatly decelerated after the operation of the reverse rotation is stopped. When the timing T1 in which the waveform G2 is lower than 0 degrees is located immediately after the timing Turn when the operation is stopped, the estimated electric angle θe becomes less than 0 degrees at the timing T1, and the electric angle signal FG becomes a low level.

After that, at timing T2, the estimation is switched to the estimation by the third electric angle estimation unit 23. At this time, since the actual rotation of the rotor is slower than the waveform G2, the estimated electric angle θe of the third electric angle estimation unit 23 shown by the waveform G3 still exceeds 0 degrees as shown in the timing T2 of FIG. .. In this case, when the immediately preceding electric angle θp and the estimated electric angle θe are acquired before and after the timing T2, the immediately preceding electric angle θp becomes negative and the estimated electric angle θe becomes positive. In this case, YES is satisfied in steps S13 and S14, and NO (reverse rotation) is satisfied in steps S15 and S21.

In this case, if steps S21 and S23 are not executed and the process shifts to step S22 when NO in step S15, the electric angle signal FG is displayed as shown by the waveform G4 shown by the alternate long and short dash line in FIG. Signal cracking will occur. When a signal crack such as the waveform G4 occurs in the electric angle signal FG, there is a possibility that an external circuit or an external device that uses the electric angle signal FG externally cannot correctly recognize the electric angle of the motor 1.

Therefore, the change in the estimated electric angle θe immediately after the timing T2 when the estimation by the second electric angle estimation unit 22 is switched to the estimation by the third electric angle estimation unit 23 is in the direction opposite to the rotation direction of the rotor immediately before the timing T2. When corresponding to the rotation direction (YES in steps S13 and S14, NO in steps S15 and S21), the electric angle signal FG is output at the same low level as immediately before switching.

Therefore, the electric angle signal output unit 24 can prevent the signal cracking of the electric angle signal FG as described above by executing steps S13 to S15 and S21 to S23.

On the other hand, in step S14, when the immediately preceding electric angle θp is 0 degrees or more (NO in step S14), the process shifts to step S31 (FIG. 5).

In step S31, the electric angle signal output unit 24 maintains the signal level of the electric angle signal FG as it is (step S31), and shifts the process to step S19.

YES in step S13 and NO in step S14 mean that the estimated electric angle θe and the immediately preceding electric angle θp are both 0 degrees or more. In this case, the electric angle signal FG is maintained at a high level in both FIG. 9 for forward rotation and FIG. 10 for reverse rotation.

On the other hand, in step S13, when the estimated electric angle θe is less than 0 degrees (NO in step S13), the process shifts to step S41 (FIG. 6). In step S41, the electric angle signal output unit 24 compares the immediately preceding electric angle θp with 0 degrees (step S41). When the immediately preceding electric angle θp is 0 degrees or more (YES in step S41), the process proceeds to step S42.

NO in step S13 and YES in step S41 mean that the estimated electric angle θe has changed from plus to minus 0 degrees or from plus to 0 degrees.

In step S42, the electric angle signal output unit 24 confirms the presence or absence of angle inversion (step S42).

When the angle is inverted (YES in step S42), the electric angle signal output unit 24 confirms whether or not the rotation control direction by the motor control unit 25 is forward rotation (step S43). If it is a normal rotation (YES in step S43), it corresponds to the timing Tr in FIG. 9 showing the normal rotation. Therefore, the electric angle signal output unit 24 lowers the electric angle signal FG to a low level (step S44: timing Tr). , The process shifts to step S19.

On the other hand, if the rotation is reverse (NO in step S43), the signal level of the electric angle signal FG is maintained as it is (step S45), and the process proceeds to step S19. That is, the electric angle signal FG is output at the same high level as immediately before the timing T2 when the estimation by the second electric angle estimation unit 22 is switched to the estimation by the third electric angle estimation unit 23.

Here, NO in step S13 and YES in step S41 mean that the estimated electric angle θe straddles 0 degrees from plus to minus, or changes from 0 degrees to minus, and further has angle reversal. In the case of (YES in step S43), if the reverse rotation is shown in FIG. 10, the angle inversion timing Tr changes from minus to plus across 0 degrees, and therefore, normally, forward rotation (YES in step S43). It should be YES) in step S43. Here, the reverse rotation (NO in step S43) occurs in the following cases.

FIG. 13 is an enlarged waveform diagram showing before and after the timing Turn when the rotation of the rotor is greatly decelerated after the operation of the reverse rotation is stopped. When the timing Tr of the angle inversion based on the waveform G2 is located immediately after the timing Turn when the operation is stopped, the estimated electric angle θe exceeds 0 degrees in the timing Tr, and the electric angle signal FG becomes a high level.

After that, at timing T2, the estimation is switched to the estimation by the third electric angle estimation unit 23. At this time, since the actual rotation of the rotor is slower than the waveform G2, the estimated electric angle θe of the third electric angle estimation unit 23 is still less than 0 degrees as in the waveform G3 at the timing T2 in FIG. In this case, when the immediately preceding electric angle θp and the estimated electric angle θe are acquired before and after the timing T2, the immediately preceding electric angle θp becomes positive and the estimated electric angle θe becomes negative. In this case, the conditions of NO in step S13, YES in steps S41 and S42, and NO (reverse rotation) in step S43 are satisfied.

In this case, if steps S43 and S45 are not executed and the process shifts to step S44 when YES in step S42, the electric angle signal FG is displayed as shown by the waveform G4 shown by the alternate long and short dash line in FIG. Signal cracking will occur. When a signal crack such as the waveform G4 occurs in the electric angle signal FG, there is a possibility that an external circuit or an external device that uses the electric angle signal FG externally cannot correctly recognize the electric angle of the motor 1.

Therefore, the change in the estimated electric angle θe immediately after the timing T2 when the estimation by the second electric angle estimation unit 22 is switched to the estimation by the third electric angle estimation unit 23 is in the direction opposite to the rotation direction of the rotor immediately before the timing T2. When corresponding to the rotation direction (NO in step S13, YES in steps S41 and S42, NO in step S43), the electric angle signal output unit 24 outputs the electric angle signal FG at the same high level as immediately before switching.

Therefore, the electric angle signal output unit 24 can prevent the signal cracking of the electric angle signal FG as described above by executing steps S13 and S41 to S45.

On the other hand, in step S42, when there is no angle inversion (NO in step S42), the process shifts to step S51 (FIG. 7). When there is no angle inversion (NO in step S42), it means that the estimated electric angle θe changes in a slope shape from plus to minus.

Next, in step S51, the electric angle signal output unit 24 confirms whether or not the rotation control direction by the motor control unit 25 is reverse rotation (step S51). If it is a reverse rotation (YES in step S51), it corresponds to the timing T1 in FIG. 10 showing the reverse rotation. Therefore, the electric angle signal output unit 24 lowers the electric angle signal FG to a low level (step S52: timing T1). , The process shifts to step S19.

On the other hand, if the rotation is forward (NO in step S51), the signal level of the electric angle signal FG is maintained as it is (step S53). That is, the electric angle signal FG is output at the same high level as immediately before the timing T2 when the estimation by the second electric angle estimation unit 22 is switched to the estimation by the third electric angle estimation unit 23.

Here, NO in step S13 and YES in step S41 mean that the estimated electric angle θe has changed from plus to minus 0 degrees or from plus to 0 degrees, and there is no angle inversion. In the case of (NO in step S42), if it is a forward rotation shown in FIG. 9, it changes from minus to plus across 0 degrees at timing T1, and therefore, normally, in step S51, reverse rotation (in step S51). YES) should be. Here, the forward rotation (NO in step S51) occurs in the following cases.

FIG. 14 is an enlarged waveform diagram showing before and after the timing Turn when the rotation of the rotor is greatly decelerated after the operation of the forward rotation is stopped. When the timing T1 at which the waveform G2 becomes 0 degrees or more is located immediately after the timing Turn when the operation is stopped, the estimated electric angle θe becomes 0 degrees or more at the timing T1, and the electric angle signal FG becomes a high level.

After that, at timing T2, the estimation is switched to the estimation by the third electric angle estimation unit 23. At this time, since the actual rotation of the rotor is slower than the waveform G2, the estimated electric angle θe of the third electric angle estimation unit 23 shown by the waveform G3 does not yet exceed 0 degrees as shown in the timing T2 of FIG. .. In this case, when the immediately preceding electric angle θp and the estimated electric angle θe are acquired before and after the timing T2, the immediately preceding electric angle θp becomes positive and the estimated electric angle θe becomes negative. In this case, the conditions of NO in step S13, YES in step S41, and NO (forward rotation) in steps S42 and S51 are satisfied.

In this case, if steps S51 and S53 are not executed and the process shifts to step S52 when NO in step S42, the electric angle signal FG is displayed as shown by the waveform G4 shown by the alternate long and short dash line in FIG. Signal cracking will occur. When a signal crack such as the waveform G4 occurs in the electric angle signal FG, there is a possibility that an external circuit or an external device that uses the electric angle signal FG externally cannot correctly recognize the electric angle of the motor 1.

Therefore, the change in the estimated electric angle θe immediately after the timing T2 when the estimation by the second electric angle estimation unit 22 is switched to the estimation by the third electric angle estimation unit 23 is in the direction opposite to the rotation direction of the rotor immediately before the timing T2. When corresponding to the rotation direction (NO in step S13, YES in step S41, NO in steps S42 and S51), the electric angle signal FG is output at the same high level as immediately before switching.

Therefore, the electric angle signal output unit 24 can prevent the signal cracking of the electric angle signal FG as described above by executing steps S13, S41, S42, S51 to S53.

On the other hand, in step S41, when the immediately preceding electric angle θp is less than 0 degrees (NO in step S41), the process shifts to step S31 (FIG. 5).

In step S31, the electric angle signal output unit 24 maintains the signal level of the electric angle signal FG as it is (step S31), and shifts the process to step S19.

NO in step S13 and NO in step S41 mean that the estimated electric angle θe and the immediately preceding electric angle θp are both less than 0 degrees. In this case, the electric angle signal FG is maintained at a low level in both FIG. 9 for forward rotation and FIG. 10 for reverse rotation.

The above-mentioned motor 1 can be applied to various devices using a motor, and is particularly suitable for a vacuum cleaner.

FIG. 15 is a perspective view showing an example of a vacuum cleaner provided with a motor 1. The vacuum cleaner 200 shown in FIG. 15 is a so-called stick-type vacuum cleaner. The motor 1 is not limited to the stick type, but can be applied to various types of vacuum cleaners such as a robot type, a canister type, and a handy type.

The vacuum cleaner 200 includes a housing 201 provided with an intake unit 202 and an exhaust unit 203. In the air passage in the housing 201, a dust collecting unit (not shown), a filter (not shown), a blower 100, and a motor 1 are arranged. Dust and other dust contained in the air flowing in the air passage is collected by the filter and collected in the dust collecting section. The motor 1 generates a driving force for driving the blower 100.

A grip portion 204 and an operation portion 205 are provided on the upper portion of the housing 201. The user sets the operation of the vacuum cleaner 200 by operating the operation unit 205. By operating the operation unit 205, for example, the start of operation of the motor 1, the stop of operation, the change of the rotation speed, and the like are instructed. A rod-shaped suction pipe 206 is connected to the intake portion 202. A suction nozzle 207 is attached to the tip of the suction tube 206.

The motor 1 has an electric angle estimation device 2. According to the electric angle estimation device 2 included in the motor 1, it is easy to estimate the estimated electric angle θe, which is the electric angle of the rotor immediately after the motor operation is stopped and the rotation due to inertia is started. Therefore, it becomes easy to stably estimate the estimated electric angle θe even when the operation start and stop are frequently repeated as in the vacuum cleaner 200. In this embodiment, the vacuum cleaner 200 includes a motor 1. As a result, it becomes easy to drive and control the motor 1 based on the estimated electric angle θe. Further, in the electric angle estimation method in the present embodiment, (a) the electric angle is estimated by the electric angle θe while the motor 1 has a correlation between the energized state of one or a plurality of coils and the electric angle of the rotor. Further, (b) the electric angle after the operation of the motor 1 is stopped is estimated as the estimated electric angle θe based on the rotation speed of the rotor immediately before the operation is stopped. As a result, the electric angle of the rotor can be estimated with high accuracy even after the operation of the motor 1 is stopped.

1 Motor 2 Electric angle estimation device 3 Stator 4 Inverter circuit 21 First electric angle estimation unit 22 Second electric angle estimation unit 23 Third electric angle estimation unit 24 Electric angle signal output unit 25 Motor control unit 26 Storage unit 27 Voltage detection circuit 100 Blower 200 Vacuum cleaner 201 Housing 202 Intake part 203 Exhaust part 204 Grip part 205 Operation part 206 Suction pipe 207 Suction nozzle D, Du1, Dv1, Dw1, Du2, Dv2, Dw2 Diode FG Electric angle signal G1, G2, G3 , G4 waveform Lu, Lv, Lw Coil Q, Qu1, Qv1, Qw1, Qu2, Qv2, Qw2 Switching element T1, T2, T3, Toff Timing Vu, Vv, Vw Coil voltage t Time ts Switching time θo Reference angle θ1, θ2 Electric angle θe Estimated electric angle θp Immediately before electric angle

Claims (13)

A first electric angle estimation unit that estimates the electric angle as an estimated electric angle while the motor has a correlation between the energization state of one or a plurality of coils and the electric angle of the rotor.
An electric angle estimation unit including a second electric angle estimation unit that estimates the electric angle after the motor operation is stopped as the estimated electric angle based on the rotation speed of the rotor immediately before the operation is stopped. Device. The electric angle estimation device according to claim 1, wherein the first electric angle estimation unit and the second electric angle estimation unit are composed of a single element. The second electric angle estimation unit estimates the estimated electric angle after the operation is stopped, assuming that the rotation speed of the rotor after the operation is stopped is equal to the rotation speed immediately before the stop. The electric angle estimation device according to claim 1 or 2. Further provided with a storage unit that previously stores the negative acceleration when the operation is stopped,
The second electric angle estimation unit estimates the electric angle after the operation is stopped as the estimated electric angle based on the rotation speed immediately before the stop and the negative acceleration. 2. The electric angle estimation device according to 2. After the switching conditions set in advance during the estimation period of the electric angle by the second electric angle estimation unit are satisfied, the electric angle is based on the voltage induced in at least one of the one or a plurality of coils. The electric angle estimation device according to any one of claims 1 to 4, further comprising a third electric angle estimation unit that estimates the estimated electric angle. The electric angle estimation device according to claim 5, wherein the first electric angle estimation unit, the second electric angle estimation unit, and the third electric angle estimation unit are composed of a single element. The electric angle estimation device according to claim 5 or 6, wherein the switching condition is that a preset switching time elapses from the time when the operation is stopped. The electrical angle according to claim 5 or 6, wherein the switching condition is that the reflux current flowing due to the counter electromotive force generated in the at least one coil due to the stop of the operation is lower than the preset switching threshold value. Estimator. The preset reference angle of the estimated electrical angle is represented by a positive sign, the range of 180 degrees in one direction from the reference angle is represented by a positive sign, and the range of 180 degrees in the other direction from the reference angle is represented by a negative sign. In this case, when the estimated electric angle is a positive value less than 180 degrees, the signal level of the electric angle signal representing the estimated electric angle is set as the first level, and the estimated electric angle has an absolute value of 180. Further, an electric angle signal output unit is provided, which sets the signal level of the electric angle signal to a second level different from the first level when the value is less than the negative value.
In the electric angle signal output unit, the change in the estimated electric angle immediately after switching from the estimation by the second electric angle estimation unit to the estimation by the third electric angle estimation unit is the rotation direction of the rotor immediately before the switching. The electric angle estimation device according to any one of claims 5 to 8, which outputs the electric angle signal at the same signal level as immediately before the switching when corresponding to the rotation direction in the opposite direction. The electric angle estimation device according to any one of claims 1 to 9, further comprising a motor control unit that controls an energization state of the coil based on the estimated electric angle. A motor including the electric angle estimation device according to any one of claims 1 to 10. A vacuum cleaner comprising the motor according to claim 11. (A) While the motor has a correlation between the energized state of one or a plurality of coils and the electric angle of the rotor, the electric angle is estimated as an estimated electric angle.
(B) An electric angle estimation method for estimating the electric angle after the operation of the motor is stopped as the estimated electric angle based on the rotation speed of the rotor immediately before the operation is stopped.

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