Motor control device, washing machine, and motor control method

Abstract

To provide a motor control device and a washing machine that can easily suppress false detection of step-out.SOLUTION: A motor control device according to the present disclosure is a motor control device for controlling a synchronous motor, and includes speed estimation means for estimating a rotational speed of a rotor of the motor; a speed command output unit for outputting a speed command for the rotational speed of the rotor; drive control means for controlling driving of the motor such that the estimated rotational speed obtained by estimation by the speed estimation means follows the speed command; step-out detection means for detecting step-out in a detection section during rotational operation of the motor; and detection section change means for changing a range of the detection section based on a first condition.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present disclosure relates to a motor control device, a washing machine, and a method for controlling a motor. [Background technology]

[0002] Patent Document 1 describes a technology for detecting loss of synchronism in a synchronous motor drive device, which includes an inverter that applies voltage to the motor, a current detection means that detects the phase current flowing through the motor, and a control means that controls the voltage that the inverter applies to the motor.The control means calculates the magnetic flux of the motor based on the output of the current detection means and a command value for the motor's rotation speed, and when the calculated value falls below a predetermined threshold, outputs a signal indicating that the motor has lost synchronism.

[0003] Patent Document 2 has a power supply circuit that supplies current to the windings of an electric motor and has the characteristic that the phase of the current relative to the permanent magnet changes depending on the magnitude of the electromotive force.The power supply circuit is configured to change the frequency of the current when a step-out occurs and then restart the motor, thereby reducing false detection of step-out even in cases where the motor has a high winding resistance or is driven at low speeds and with low induced electromotive force. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-92787 [Patent Document 2] International Publication No. 2018 / 123524 Summary of the Invention [Problem to be solved by the invention]

[0005] The present disclosure provides a motor control device and a washing machine that can easily suppress erroneous detection of step-out by the motor control device. [Means for solving the problem]

[0006] The motor control device and washing machine disclosed herein are a motor control device that controls a synchronous motor, and include: a speed estimation means for estimating the rotational speed of a rotor of the motor; a speed command output unit that outputs a speed command for the rotational speed of the rotor; a drive control means that drives and controls the motor so that the estimated rotational speed obtained by estimation by the speed estimation means follows the speed command; a step-out detection means that detects step-out in a detection section during rotational operation of the motor; and a detection section change means that changes the range of the detection section based on a first condition. [Effects of the Invention]

[0007] The motor control device and washing machine according to the present disclosure can easily suppress false detection of out-of-step. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a cross-sectional view showing a simplified configuration of a main part of a washing machine according to a first embodiment; [Figure 2] FIG. 1 is a simplified block diagram showing the configuration of a motor drive system according to a first embodiment. [Figure 3] FIG. 1 is a diagram showing some of the functions of the control means 20 according to the first embodiment. [Figure 4] Equivalent circuit diagram of motor 4 in embodiment 1 [Figure 5] FIG. 1 is a simplified block diagram showing the configuration of a control unit 51 when open-loop control is performed in the first embodiment. [Figure 6] FIG. 1 is a simplified block diagram showing the configuration of a control unit 51 when feedback control is performed in the first embodiment. [Figure 7] FIG. 1 is a block diagram showing a configuration of a speed phase estimation means 21 according to a first embodiment. [Figure 8] 1 is a timing chart showing a simplified agitation operation by the pulsator 1 according to the first embodiment. [Figure 9] FIG. 1 is a flowchart showing a simplified motor operation according to the first embodiment. [Figure 10]Flowchart of step-out detection processing in the first embodiment [Figure 11] Flowchart of section detection processing in the first embodiment [Figure 12] FIG. 10 is a schematic diagram showing the relationship between the target rotation speed and successive target rotation speeds in the first embodiment; DETAILED DESCRIPTION OF THE INVENTION

[0009] (Findings that formed the basis of this disclosure) At the time when the inventors came up with the idea for the present disclosure, washing machines were known that used position sensors such as Hall elements or rotary encoders to detect motor rotation (detect rotation speed and rotation position), and washing machines that controlled the motor using a so-called sensorless method, which detects rotation without using a position sensor, from the standpoint of cost reduction and structural constraints, etc.

[0010] One type of sensorless method is a method that uses induced voltage. This method detects the motor current flowing through the motor, calculates the induced voltage based on the voltage applied to the motor and the motor current, and estimates the motor rotation speed based on this induced voltage.

[0011] The induced voltage can be calculated using the formula: the voltage (Vd, Vq) is the magnetic flux Ψ (magnetic flux Ψa of the permanent magnet + winding current (Id, Iq) × inductance (Ld, Lq)) multiplied by ω (speed) plus the drop (RaId, RaIq) due to resistance Ra.

[0012] Therefore, the inventors of the present invention discovered a problem in that when the rotation speed of the motor or the load changes suddenly, the calculated induced voltage is also calculated accordingly, resulting in a large deviation from the theoretical value, and there is a high possibility of false detection due to out-of-step detection.

[0013] Furthermore, at the time the inventors arrived at the idea of ​​the present disclosure, washing machines with a pulsator (agitation mechanism) located at the bottom of the washing tub (storage tub) were known. In such washing machines, agitation operations are performed by rotating the pulsator with a motor during laundry load determination, the washing process, the rinsing process, etc., to detect the load of laundry on the pulsator and generate a water current in the washing tub to agitate the laundry. Therefore, in such washing machines, the rotation speed of the motor or the load may suddenly fluctuate during the agitation operation.

[0014] Therefore, the inventors of the present invention have also discovered that the agitation operation of a washing machine with a pulsator (agitation mechanism) located at the bottom of the washing tub (storage tub) is likely to cause a large deviation between the induced voltage and the theoretical value, which increases the likelihood of false detection due to out-of-step detection. They have also discovered the problem that if false detection occurs when determining the amount of laundry, it becomes impossible to set the optimal process and water volume for the laundry volume.

[0015] In order to solve these problems, the inventors came up with the idea that by limiting the range in which out-of-step detection is performed during stirring operation to a certain section excluding sections in which the motor rotation speed or load fluctuates suddenly, it would be possible to accurately detect out-of-step (without determining that an out-of-step has occurred when in fact it has not) under simple conditions, and this idea formed the subject of the present disclosure.

[0016] Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to these embodiments.

[0017] (Embodiment 1) Hereinafter, the first embodiment will be described with reference to FIGS.

[0018] [1-1. Washing machine configuration] FIG. 1 is a cross-sectional view of a main part, showing a simplified configuration of a washing machine according to a first embodiment.

[0019] Washing machine 100 is provided with a water receiving tub 3 inside an outer frame 9. A washing / spinning tub 2 (storage tub) is disposed inside water receiving tub 3 so as to be rotatable left and right. A pulsator 1 (agitation mechanism) is disposed at the inner bottom of washing / spinning tub 2 so as to be rotatable left and right.

[0020] A panel unit 10 is disposed on top of the outer frame 9 of the washing machine. A lid 11 that can be opened and closed is disposed on the top surface of the panel unit 10. A control device 13 having a display unit 12 is disposed inside the panel unit 10. The control device 13 controls all of the washing processes performed by the washing machine. The washing processes include determining the amount of laundry, a washing process, a rinsing process, and a spin-drying process, and the desired washing process is performed according to the washing course input by the user.

[0021] The control device 13 controls the operation of the motor 4, the speed reducer / clutch 6, the geared motor 7, the water supply valve 14, the drain valve 15, and the like, which will be described later, to thereby carry out the washing operation.

[0022] A motor 4 is disposed on the outer bottom of the water receiving tub 3. When the rotor of the motor 4 rotates, the torque is transmitted to the pulsator 1 via a motor pulley 31 (transmission mechanism), a belt 5 (transmission mechanism), an impeller pulley 32 (transmission mechanism), and a speed reducer / clutch 6 (transmission mechanism). The speed reducer / clutch 6 connects or disconnects the pulsator 1 from the washing / spinning tub 2. This allows the motor 4 to rotate the pulsator 1 and the washing / spinning tub 2 together, or to rotate only the pulsator 1. In this embodiment, the operation of rotating the pulsator 1 and the washing / spinning tub 2 together is defined as a tub rotation operation, and the operation of rotating only the pulsator 1 is defined as a stirring operation.

[0023] Geared motor 7 has brake belt 8 that contacts the rotating part to mechanically brake the rotation of washing / spin-drying tub 2. In this embodiment, contact of brake belt 8 with the rotating part may be referred to as a stopping operation.

[0024] [1-2. Motor control device configuration] FIG. 2 is a block diagram showing a simplified configuration of the motor drive system. The motor drive system includes a rectifier circuit 16, an inverter circuit 17, a current detection means 18, a PWM control means 19, and a control means 20. In other words, the inverter circuit 17, the current detection means 18, the PWM control means 19, and the control means 20 constitute a drive control means. In this embodiment, the inverter circuit 17, the current detection means 18, the PWM control means 19, and the control means 20 constitute a motor control device. In other words, the rectifier circuit 16 can be referred to as a power supply system, the inverter circuit 17 and the current detection means 18 as a drive system, and the motor 4 as an object to be driven. In this embodiment, the operation of the motor control device is sometimes described as the operation of the control means 20, but this does not limit the configuration of the motor control device.

[0025] The control means 20 is configured using a microcontroller, etc. The control means 20 may be part of the functions of the control device 13.

[0026] FIG. 3 is a diagram showing some of the functions of the control means 20. As shown in FIG.

[0027] The control means 20 is a so-called microcomputer. The control means 20 has a control unit 51, a laundry amount detection unit 52, a setting unit 53, an error calculation unit 54, a correction unit 55, and a sequence control unit 56 as functions realized by a processor such as a CPU executing a program. The control means 20 may be configured such that the error calculation unit 54 and the correction unit 55 are omitted. The details of the processing executed by these units will be described later. In this embodiment, the sequence control unit 56 is a part of the control means 20, and therefore the control by the sequence control unit 56 may be rephrased as the control by the control means 20.

[0028] Referring to Fig. 2, the rectifier circuit 16 is configured as, for example, a voltage doubler rectifier circuit. The rectifier circuit 16 voltage-doubles and rectifies an AC voltage input from an AC power supply, thereby inputting a DC voltage Vdc to the inverter circuit 17. The inverter circuit 17 is a motor drive circuit that drives the motor 4 with applied voltages Vu, Vv, and Vw, and is configured using, for example, an intelligent power module (hereinafter referred to as "IPM"). The IPM incorporates a three-phase full-bridge inverter circuit, a drive circuit, and a protection circuit. The three-phase full-bridge inverter circuit has six power switching elements such as insulated gate bipolar transistors (hereinafter referred to as "IGBTs"), and diodes connected in anti-parallel to each power switching element.

[0029] The current detection means 18 detects the current value of the motor current flowing through the motor 4 by measuring the voltage across the shunt resistor. The shunt resistor is connected to a wiring path between the negative voltage terminal of the inverter circuit 17 and the negative voltage terminal of the motor 4. The motor current includes phase currents Iu, Iv, and Iw of the motor 4. The current detection means 18 inputs the phase currents Iu, Iv, and Iw to the control means 20.

[0030] The control means 20 inputs voltage commands Vus, Vvs, and Vws for driving the three-phase motor to the PWM control means 19.

[0031] The PWM control means 19 generates a PWM signal based on the voltage commands Vus, Vvs, and Vws, and inputs the PWM signal to the inverter circuit 17 to control the switching operation of the IGBTs included in the inverter circuit 17 .

[0032] FIG. 4 is an equivalent circuit diagram of the motor 4.

[0033] For simplicity of explanation, an example of a two-pole configuration in which one mechanical angle rotation is one electrical angle rotation is shown in Figure 4. If the number of poles changes to four, eight, etc., the relationship changes to one mechanical angle rotation being two, four, etc. electrical angle rotations.

[0034] The motor 4 is a three-phase synchronous motor and has three-phase windings 4a, 4b, and 4c (U, V, and W), and a permanent magnet 4d, which is a rotor that rotates around a rotation axis. The axis that passes through the N-pole side of the permanent magnet 4d in the positive direction is defined as the d-axis (direct axis), and the axis perpendicular to this is defined as the q-axis (quadrature axis). With these definitions, the torque of the motor 4 is primarily governed by the magnetic field in the q-axis direction. Furthermore, the phase θ (electrical angle) is the angle formed by the axis α that passes through the U-phase winding 4a and the d-axis. All phases described below are electrical angles. Note that the inductance of the winding when a voltage is applied to generate a magnetic field in the d-axis direction is defined as Ld, and the inductance in the q-axis direction is defined as Lq. In an interior magnet type three-phase synchronous motor, Ld <Lqとなる。

[0035] The washing machine according to this embodiment is a sensorless washing machine using induced voltage. As described above, the sensorless method using induced voltage has, as the control period for the motor 4, an open-loop control period in the low-speed range and a feedback control period in the high-speed range. Open-loop control is a control method in which the rotation speed of the motor 4 is not estimated and the estimated value of the rotation speed is not fed back to the input side. In open-loop control, the voltage applied to the motor 4 is controlled based on the target value of the control current (magnetic flux current or torque current) supplied to the motor 4 and the target value of the rotation speed of the motor 4. In feedback control, the rotation speed of the motor 4 is controlled based on the induced voltage. In this control, the rotation speed is estimated and the estimated value of the rotation speed is fed back to the input side. In the feedback control, the control current (magnetic flux current or torque current) and the voltage applied to the motor 4 are controlled based on the deviation between the target value of the rotation speed of the motor 4 and the fed back estimated value.

[0036] Because the sensorless system does not use a position sensor, the control unit 20 cannot accurately detect the rotor position. In particular, in open-loop control, the rotational speed of the motor 4 is not estimated, and the estimated rotational speed value is not fed back to the input side. Therefore, the control unit 20 assumes the rotor position to be a phase θc, and an error Δθ occurs between the phase θc and the phase θ. Therefore, the axis controlled by the control unit 20 assuming the phase θc is the γ-axis (estimated d-axis) relative to the d-axis, and the δ-axis (estimated q-axis) relative to the q-axis. Hereinafter, the current component corresponding to the d-axis magnetic flux current is referred to as the γ-axis current Iγ, and the current component corresponding to the q-axis torque current is referred to as the δ-axis current Iδ. Furthermore, the command voltage component corresponding to the d-axis magnetic flux is referred to as the γ-axis voltage command Vγs, and the command voltage component corresponding to the q-axis torque is referred to as the δ-axis voltage command Vδs.

[0037] In this embodiment, the control means 20 is a speed command output unit.

[0038] FIG. 5 is a simplified block diagram showing the configuration of the control unit 51 when open-loop control is performed.

[0039] The phase calculation means 30 receives a speed command ωs corresponding to a target value for the rotational speed of the motor 4 and an initial phase θinit of the motor 4. The phase calculation means 30 calculates the phase θ by integrating the phase per unit time based on the initial phase θinit and the speed command ωs set for each unit time. Since open-loop control does not perform speed estimation, the speed command ωs is treated as the speed ω as is. The phase calculation means 30 inputs the phase θ to the three-phase to two-phase converter 22 and the two-phase to three-phase converter 25.

[0040] The phase θ and the phase currents Iu, Iv, and Iw are input to the three-phase to two-phase converter 22. The three-phase to two-phase converter 22 calculates the δ-axis current Iδ and the γ-axis current Iγ using the following equation (1) based on the phase θ, the phase currents Iu, Iv, and Iw, and sine wave data required for conversion from the stationary coordinate system to the rotating coordinate system.

[0041]

number

[0042] The Iδ error amplifier 23 receives an error ΔIδ between the δ-axis current Iδ and a δ-axis current command Iδs corresponding to the target value of the control current. The Iδ error amplifier 23 calculates a δ-axis voltage command Vδs as the sum of a proportional component and an integral component. The Iδ error amplifier 23 inputs the δ-axis voltage command Vδs to a two-phase to three-phase converter 25.

[0043] An error ΔIγ between a γ-axis current command Iγs corresponding to a target value of the control current and the γ-axis current Iγ is input to the Iγ error amplifier 24. The Iγ error amplifier 24 calculates a γ-axis voltage command Vγs as the sum of a proportional component and an integral component. The Iγ error amplifier 24 inputs the γ-axis voltage command Vγs to a two-phase to three-phase converter 25.

[0044] At least one of the δ-axis current command Iδs and the γ-axis current command Iγs corresponds to the control current supplied from the inverter circuit 17 to the motor 4 during the open-loop control period.

[0045] The phase θ, a δ-axis voltage command Vδs, and a γ-axis voltage command Vγs are input to the two-phase to three-phase converter 25. The two-phase to three-phase converter 25 calculates sinusoidal voltage commands Vus, Vvs, and Vws using the following equation (2) based on the phase θ, the δ-axis voltage command Vδs, the γ-axis voltage command Vγs, and sinusoidal wave data required for inverse transformation from the rotating coordinate system to the stationary coordinate system.

[0046]

number

[0047] The two-phase to three-phase converter 25 inputs voltage commands Vus, Vvs, and Vws to the PWM control means 19 .

[0048] FIG. 6 is a simplified block diagram showing the configuration of the control unit 51 when feedback control is performed.

[0049] The speed phase estimation means 21 receives the initial phase θinit of the motor 4, the δ-axis current Iδ, the γ-axis current Iγ, and the γ-axis voltage command Vγs.

[0050] FIG. 7 is a block diagram showing the configuration of the speed phase estimation means 21. As shown in FIG.

[0051] The speed phase estimation means 21 has a γ-axis induced voltage calculator 28 and a γ-axis induced voltage error amplifier 29. The γ-axis induced voltage calculator 28 calculates the γ-axis induced voltage Veγ by the following equation (3) based on the inductance value L, the resistance value Ra, the δ-axis current Iδ, the γ-axis current Iγ, the γ-axis voltage command Vγs, and the estimated speed ω.

[0052]

number

[0053] With the γ-axis induced voltage command Veγs=0, the error ΔVeγ relative to the γ-axis induced voltage command Veγs is input to the γ-axis induced voltage error amplifier 29 .

[0054] The γ-axis induced voltage error amplifier 29 outputs an estimated speed ω calculated from the integral gain Kω, adds the estimated speed ω to a value calculated from the proportional gain Kθ, and performs time integration in an integrator to output an estimated phase θ.

[0055] Referring to FIG. 6, the speed phase estimation means 21 inputs the estimated phase θ to the three-phase to two-phase converter 22 and the two-phase to three-phase converter 25.

[0056] An error Δω between a speed command ωs corresponding to a target value of the rotation speed and an estimated speed ω is input to the speed error amplifier 26. The speed error amplifier 26 calculates a δ-axis current command Iδs as the sum of a proportional component and an integral component.

[0057] The field-weakening setting means 27 receives the estimated speed ω and the DC voltage Vdc input to the inverter circuit 17. The field-weakening setting means 27 calculates a γ-axis current command Iγs in the negative direction based on the estimated speed ω and the DC voltage Vdc.

[0058] An error ΔIδ between the δ-axis current command Iδs and the δ-axis current Iδ is input to the Iδ error amplifier 23. The Iδ error amplifier 23 calculates a δ-axis voltage command Vδs as the sum of a proportional component and an integral component. The Iδ error amplifier 23 inputs the δ-axis voltage command Vδs to a two-phase to three-phase converter 25.

[0059] An error ΔIγ between the γ-axis current command Iγs and the γ-axis current Iγ is input to the Iγ error amplifier 24. The Iγ error amplifier 24 calculates a γ-axis voltage command Vγs as the sum of a proportional component and an integral component. The Iγ error amplifier 24 inputs the γ-axis voltage command Vγs to a two-phase to three-phase converter 25.

[0060] At least one of the δ-axis current command Iδs and the γ-axis current command Iγs corresponds to the control current supplied from the inverter circuit 17 to the motor 4 during the feedback control period.

[0061] The two-phase to three-phase converter 25 receives the estimated phase θ, the δ-axis voltage command Vδs, and the γ-axis voltage command Vγs. The two-phase to three-phase converter 25 calculates the sinusoidal voltage commands Vus, Vvs, and Vws using the above equation (2) based on the estimated phase θ, the δ-axis voltage command Vδs, the γ-axis voltage command Vγs, and sine wave data required for inverse transformation from the rotating coordinate system to the stationary coordinate system. The two-phase to three-phase converter 25 inputs the voltage commands Vus, Vvs, and Vws to the PWM control means 19.

[0062] [1-3. Mixing and tank rotation operations] FIG. 8 is a timing chart showing the stirring operation of the pulsator 1 in a simplified manner.

[0063] The agitation operation is an operation in which the pulsator 1 is driven to rotate for a predetermined time range, and is performed intermittently multiple times (twice in FIG. 8, for agitation operation M1 and agitation operation M2). During the agitation operation, the pulsator 1 is accelerated and driven to rotate up to a target value R0, which is the target rotation speed of the pulsator 1 set for the agitation operation (acceleration section E1). Once the target value R0 is reached, the pulsator 1 is driven to maintain the rotation speed for a predetermined time (target rotation speed section E2). After the predetermined time has elapsed, the geared motor 7 is driven to control the stopping operation by the brake belt 8 until the rotation of the pulsator 1 stops (deceleration section E3).

[0064] For example, the target value R0 of the rotation speed in the stirring operation may be set to 80 rpm to 120 rpm, and the target value R0 of the rotation speed in the tank rotation operation may be set to 680 rpm to 720 rpm. The rotation direction of the pulsator 1 in the stirring operation may be different for each stirring operation (for example, between stirring operations M1 and M2 described below), or may be the same. Furthermore, at least one of the target value R0 of the rotation speed, the time interval, and the acceleration may be different.

[0065] In this embodiment, step-out means that the actual rotation speed of the motor 4 deviates significantly from the target rotation speed.

[0066] During the tub rotation operation, water receiving tub 3 vibrates as washing and spin tub 2 rotates, which is highly likely to vibrate outer frame 9, and if step-out occurs, it will have a significant impact on the vibration of outer frame 9. Therefore, in this embodiment, step-out detection is performed to check whether step-out has occurred in all sections of the tub rotation operation (acceleration section E1, target rotation speed section E2, deceleration section E3).

[0067] On the other hand, the stirring operation rarely causes large vibrations of the water receiving tub 3 due to the rotation of the pulsator 1, and is unlikely to vibrate the outer frame 9. Therefore, even if a step-out occurs, it is not affected by the vibration of the outer frame 9. Therefore, in this embodiment, only in the stirring operation, out-of-step detection is not performed in a section where there is a high possibility of false detection of out-of-step detection.

[0068] Specifically, while the motor 4 is driving, the speed phase estimation means 21 always calculates the γ-axis induced voltage Veγ by the above formula (3) and performs demagnetization detection of the motor 4. However, in the stirring operation, in the time ranges of T1 - T2 and T5 - T6 which are the acceleration sections E1, and in the time ranges of T3 - T4 and T6 - T7 which are the deceleration sections E3, there is a risk of false detection due to load fluctuations. Therefore, in the stirring operation, only in the time ranges of T2 - T3 and T7 - T8 which are the target rotation speed sections E2, the control means 20 compares the γ-axis induced voltage Veγ with the demagnetization detection threshold value Vα set in the control means 20 in advance. When Veγ < Vα for the γ-axis induced voltage, it is determined that the motor 4 is demagnetized. [[ID=​​​​​​​​​​​​​​​​​​​​​

[0074] When the predetermined time has elapsed (S103, Yes), the control device 13 ends the motor operation (S104).

[0075] FIG. 10 is a flowchart of the out-of-step detection process according to the first embodiment.

[0076] When the step-out detection process starts (S201), the control means 20 determines whether or not the drive state quantity of the motor 4 is being measured using the induced voltage (S202). The control means 20 may determine No in S202 if the control is the open loop control described above, or Yes in S202 if the control is the feedback control described above.

[0077] If the induced voltage is not used (S202, No), the process proceeds to a step-out detection method different from the step-out detection process of this embodiment (S202). The step-out detection method is, for example, a detection using current information or rotation speed information.

[0078] If an induced voltage is used (S202, Yes), the control means 20 determines whether the motor operation is a stirring operation (S205), and if the first condition is satisfied (S205, Yes), in this embodiment, if the motor operation is a stirring operation, the control means 20 executes a section detection process (S207). On the other hand, if the first condition is not satisfied (S205, No), in this embodiment, If the current operation is a tank rotation operation, step-out detection is performed in all sections of the acceleration section E1, the target rotation speed section E2, and the deceleration section E3, and the process proceeds to the next step S208.

[0079] Next, the control means 20 determines whether the induced voltage is equal to or greater than a given voltage (S208). In this embodiment, the given voltage used for the determination in S208 during the stirring operation is set as the out-of-step detection threshold Vα. S208 may also be referred to as out-of-step detection determination.

[0080] If the induced voltage is smaller than the predetermined voltage (S208, No), there is a possibility of out-of-step, so motor operation is stopped (S209). Specifically, the geared motor 7 is driven and a stopping operation is performed by the brake belt 8. After the rotation of the pulsator 1 stops, the motor is restarted (S211). In restarting the motor, the motor operation may be executed again to accelerate the rotation up to the target rotation speed of the pulsator 1 and drive the pulsator 1 to rotate. Note that if out-of-step is determined, the execution of the motor operation may be canceled. Note that since out-of-step is more likely to occur when the load is heavy, if out-of-step is determined, the laundry amount may be determined to be the maximum value within a predetermined range. Actions such as stopping, restarting, canceling execution of motor operation, and determining that an out-of-step has occurred, which are performed after it has been determined that an out-of-step has occurred, may be defined as out-of-step response actions.

[0081] If the induced voltage is equal to or greater than the predetermined voltage (S208, Yes), the out-of-step detection process is terminated (S210). The out-of-step detection process is repeatedly performed as described above.

[0082] Fig. 11 is a flowchart of the section detection process according to embodiment 1. Fig. 12 is a schematic diagram showing the relationship between the target rotation speed and the sequential target rotation speed according to embodiment 1.

[0083] 12, in the acceleration section E1, the control means 20 controls the rotation speed of the motor 4 so that it gradually coincides with the target rotation speed Rt, gradually increasing the target rotation speed Rt in stages toward the target rotation speed R0. Meanwhile, in the deceleration section E3, the control means 20 gradually decreases the target rotation speed Rt in stages toward the target rotation speed for deceleration that is set to 0.

[0084] When the interval detection process starts (S301), it is determined whether the sequential target rotation speed Rt and the target rotation speed R0 match (S302), that is, whether it is in the target rotation speed interval E2. If the sequential target rotation speed and the target rotation speed match (Yes in S302), that is, if it is in the target rotation speed interval E2, the process proceeds to S208.

[0085] If the sequential target rotation speed and the target rotation speed do not match (S302, No), i.e., if it is not in the target rotation speed section E2, step-out detection is not performed (S303), and it is determined whether the target rotation speed has been reached (S305). If the target rotation speed has not been reached (S305, Yes), i.e., if it is in the acceleration section E1, the process returns to the determination of whether the sequential target rotation speed and the target rotation speed match (S302). If the target rotation speed has already been reached (S305, Yes), i.e., if it is in the deceleration section E3, the process proceeds to S210 and the step-out detection process ends.

[0086] [1-5. Actions, etc.] The motor control device of washing machine 100 in embodiment 1 is a motor control device composed of inverter circuit 17, current detection means 18, PWM control means 19, and control means 20, and includes speed phase estimation means 21 that estimates the rotational speed of a rotating part of motor 4, control means 20 that outputs a speed command for the rotational speed of the rotating part, inverter circuit 17, current detection means 18, PWM control means 19, and control means 20 that drive and control motor 4 so that the estimated rotational speed follows the speed command, control means 20 that detects step-out in the detection section during rotation operation of motor 4, and control means 20 that changes the range of the detection section based on a first condition.

[0087] This allows the detection section of the out-of-step to be changed when the first condition is met, which indicates that the disadvantage of erroneously detecting the out-of-step is great.

[0088] The control means 20 may change the detection section when the first condition that the controlled object is not synchronized with the rotation of the motor 4 is satisfied.

[0089] As a result, when the object to be controlled is the pulsator 1, the pulsator 1 is not synchronized with the rotation of the motor 4, and therefore the first condition is met, and when the object to be controlled is the washing and spin-drying tub 2, the washing and spin-drying tub 2 is synchronized with the rotation of the motor 4, and therefore the first condition is not met.

[0090] Therefore, the detection section can be changed during the stirring operation by the pulsator 1.

[0091] The motor control device controls the tub rotation operation, which is the rotation of the washing and spin-drying tub 2, or the agitation operation, which is the rotation of the pulsator 1 relative to the washing and spin-drying tub 2, via the transmission mechanism, which is the motor pulley 31, belt 5, impeller pulley 32, and reduction mechanism / clutch 6, and the first condition may be a case where the agitation operation is controlled.

[0092] As a result, the stirring operation satisfies the first condition, but the tank rotation operation does not satisfy the first condition.

[0093] Therefore, the detection section can be changed during the stirring operation by the pulsator 1.

[0094] If the first condition is satisfied, the control means 20 may exclude from the range of the detection section the range of the second condition, which is the acceleration section E1 in which the rotation of the motor 4 is accelerated toward the target rotation speed set by the control means 20 as the target value for the motor operation, or the deceleration section E3 in which the rotation of the motor 4 is decelerated toward stopping the rotation of the motor 4.

[0095] As a result, the acceleration section E1 and deceleration section E3, which are the second condition, are excluded from the detection section, and the detection section can be limited to the target rotation speed section E2.

[0096] Therefore, during the stirring operation by the pulsator 1, the section where misdetection of out-of-step is likely to occur can be excluded from the detection section.

[0097] In the feedback control, the control means 20 performs drive control of the motor 4 so that the successive target rotation speed set by the control means 20 at predetermined time intervals until the target rotation speed is reached matches the rotation speed of the estimated rotation speed, and the range of the second condition is a range in which the successive target rotation speed does not match the target rotation speed (S302, No), and the range of the detection section may be a range in which the successive target rotation speed matches the target rotation speed (S302, Yes).

[0098] This makes it possible to determine the acceleration section E1 and deceleration section E3, which are the second condition, and to exclude them from the detection section.

[0099] In addition, the second condition may start when a predetermined time has elapsed since the motor control device started rotating the motor 4 (between T1 and T2, or T5 and T6), and end when the motor control device starts the stopping operation of the motor 4 (T3 or T7).

[0100] This makes it possible to determine the acceleration section E1 and deceleration section E3, which are the second condition, and to exclude them from the detection section.

[0101] The control means 20 calculates a first state quantity related to the motor voltage applied to the motor 4, a second state quantity related to the rotation speed of the rotor, and a third state quantity related to the motor current supplied to the motor 4. Alternatively, the control means 20 may estimate the other state quantity based on one or two of the state quantities, and detect out-of-sync based on the estimation result. Furthermore, the control means 20 may estimate the δ-axis component of the motor current as the third state quantity based on the first and second state quantities, where, assuming that an axis parallel to the magnetic flux generated by a permanent magnet provided in the rotor is the d-axis, an estimated axis for control corresponding to the d-axis is the γ-axis, and an estimated axis for control orthogonal to the γ-axis is the δ-axis, the first state quantity is represented by a δ-axis voltage command that the δ-axis component of the motor voltage should follow, and the second state quantity is represented by a first estimated rotational speed or the speed command.

[0102] (Other embodiments) As described above, the first embodiment has been described as an example of the technology disclosed in this application. However, the technology in this disclosure is not limited to this, and can be applied to embodiments in which modifications, substitutions, additions, omissions, etc. are made. Furthermore, it is also possible to combine the components described in the first embodiment above to create new embodiments. Therefore, other embodiments will be exemplified below.

[0103] In the first embodiment, a drum-type washing machine has been described as an example of a washing machine. The washing machine is not limited to the drum-type washing machine of the first embodiment, and may be a washer-dryer with a drying function or a vertical washing machine.

[0104] In the first embodiment, washing machine 100, which is a pulsator type vertical washing machine, has been described as an example of a washing machine. The washing machine is not limited to a pulsator type vertical washing machine as long as it is equipped with a motor control device. The washing machine may be, for example, a drum type washing machine or an agitator type washing machine.

[0105] In the first embodiment, as an example of the motor and transmission mechanism, a configuration in which the rotation of the motor 4 is transmitted to the pulsator 1 and the washing and spin-drying tub 2 via the belt 5 has been described, but the present invention is not limited to this. The motor and transmission mechanism may be a direct drive type that transmits the rotation of the motor to the drive mechanism and the storage tub without using a belt.

[0106] In the first embodiment, the pulsator 1 is described as an example of the stirring mechanism, but the stirring mechanism is not limited to this. For example, the stirring mechanism may be a baffle provided on the inner surface of the storage tank, or an agitator provided at the center of the storage tank and extending in the direction of the rotation axis.

[0107] In the first embodiment, steps S101 to S104, S201 to S211, and S301 to S305 have been described as examples of the detection of out-of-step by the out-of-step detecting means and the change of the detection section by the detection section change means, but the present invention is not limited to executing all of these steps. For example, the detection of out-of-step and the change of the detection section may not include some steps, or the order of the steps may be reversed. [Industrial Applicability]

[0108] The present disclosure is applicable to motor control devices and washing machines, specifically to top-loading washing machines, washer-dryers, drum-type washing machines, agitator-type washing machines, twin-tub washing machines, and commercial washer-dryers. [Explanation of symbols]

[0109] 1 Pulsator (stirring mechanism) 2 Washing and spin-drying tub (storage tub) 3 Water receiving tank 4 Motor (transmission mechanism) 5 Belt (transmission mechanism) 6. Reduction mechanism and clutch (transmission mechanism) 7 Geared motor (transmission mechanism) 8 Brake belt (transmission mechanism) 9 Outer Frame 10 Panel section 12 Display section 13 Control device 14 Water supply valve 15 Drain valve 16 Rectifier circuit 17 Inverter circuit (drive control means) 18 Current detection means (drive control means) 19 PWM control means (drive control means) 20 control means (speed command output unit, drive control means, step-out detection means, detection section change means) 21 Speed ​​phase estimation means (speed estimation means) 22 Three-phase to two-phase converter 23 Iδ error amplifier 24 Iγ error amplifier 25 2-phase to 3-phase converter 26 Speed ​​error amplifier 27 Field weakening setting means 28 γ-axis induced voltage calculator 29 γ-axis induced voltage error amplifier 30 Phase calculation means 51 Control section 52 Cloth amount detection unit 53 Setting section 54 Error calculation section 55 Correction section 100 washing machines

Claims

1. A motor control device for controlling a synchronous motor, a speed estimation means for estimating the rotation speed of the rotor of the motor; a speed command output unit that outputs a speed command for the rotation speed of the rotor; drive control means for controlling the drive of the motor so that the estimated rotational speed obtained by the estimation by the speed estimation means follows the speed command; a step-out detection means for detecting step-out in a detection section during rotation of the motor; a detection section changing means for changing the range of the detection section based on a first condition; A motor control device comprising:

2. the detection section change means changes the range of the detection section when the first condition is satisfied, that is, an object controlled by the motor control device is not synchronized with rotation of the motor. The motor control device according to claim 1 .

3. the motor control device controls the rotation of the storage tank and the relative rotation of the agitation mechanism with respect to the storage tank via a transmission mechanism that is switchably coupled to the motor; the first condition is a case where the rotation of the stirring mechanism relative to the storage tank is controlled. The motor control device according to claim 2 .

4. If the first condition is met, the detection interval change means excludes from the range of the detection interval a range that satisfies a second condition, in which the rotation of the motor is accelerating toward an arbitrary target rotation number or is decelerating toward a stop. The motor control device according to claim 1 .

5. the drive control means controls the drive of the motor so that the sequential target rotation speed of the speed command coincides with the rotation speed of the estimated rotation speed; the range of the second condition is a range in which the successive target rotation speed does not match the target rotation speed, The range of the detection section is a range in which the successive target rotation speed coincides with the target rotation speed. The motor control device according to claim 4.

6. 4. The motor control device according to claim 3, wherein the second condition starts when a predetermined time has elapsed since the motor control device started rotating the motor, and ends when the motor control device starts an operation to stop the motor.

7. The motor control device according to claim 1 ; a storage tank that is rotationally driven by the motor; a stirring mechanism provided inside the container and rotated by the motor; a transmission mechanism configured to be able to switch between a storage tank rotation operation for rotating the storage tank and a stirring operation for rotating the stirring mechanism relative to the storage tank, and which transmits the driving force of the motor to the storage tank and / or the stirring mechanism; A washing machine equipped with

8. the first condition is a case where the motor control device controls the stirring operation; The washing machine according to claim 7.

9. where an axis parallel to a magnetic flux generated by a permanent magnet provided in the rotor is defined as a d-axis, an estimated axis for control corresponding to the d-axis is defined as a γ-axis, and an estimated axis for control perpendicular to the γ-axis is defined as a δ-axis, the first state quantity is represented by a δ-axis voltage command that a δ-axis component of the motor voltage should follow, and the second state quantity is represented by the first estimated rotation speed or the speed command, and the out-of-sync detection means estimates the δ-axis component of the motor current as the third state quantity based on the first state quantity and the second state quantity, and detects out-of-sync based on the estimated δ-axis current obtained by the estimation. The motor control device according to claim 1 .

10. A method for controlling a motor, comprising: Estimating the rotational speed of the rotor of the motor; outputting a speed command for the rotation speed of the rotor; driving and controlling the motor so that the estimated rotational speed obtained by the estimation follows the speed command; Detecting step-out in a detection section during rotation of the motor; changing the range of the detection section based on a first condition; How to control a motor.

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