JP2019115504A - Washing machine - Google Patents

Abstract

To provide a washing machine which uses a new determination method in eccentricity determination which properly complements in determining a state of eccentricity at a d-axis voltage, and which can perform determination of the state of eccentricity equally with the d-axis voltage or instead of the d-axis voltage in some cases.SOLUTION: A washing machine includes: a motor M for rotationally driving a dewatering tub; and control means C for vector-controlling generation torque of the motor M. The control means C includes an eccentricity determination unit 100 which performs determination of a state of eccentricity in the dewatering tub according to the magnitude of a phase error Δθ between a phase of a d-axis estimated so as to perform the vector control and an actual phase of the d-axis.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a washing machine which can determine the eccentricity state easily and accurately even if it is sensorless.

  If the distribution of laundry in the dewatering tank of the washing machine is uneven, large vibration may occur when the dewatering operation is performed. When the dewatering tank is rotated to perform the dewatering process, if the laundry is eccentric, excessive vibration occurs, so it is necessary to stop the rotation.

  Therefore, for example, a method disclosed in Patent Document 1 is known as one that performs control to stop the rotation when necessary, by detecting the eccentricity without using a sensor.

  This method is configured to determine the occurrence of abnormal vibration based on the q-axis current, noting that there is a correlation between the q-axis current of the motor calculated for performing vector control and the eccentricity state. ing.

Patent No. 4406176

  However, since the q-axis current appears as a result of voltage control, it is susceptible to external noise, and the change as an absolute value is small. Therefore, if the eccentricity state is determined based on the q-axis current, an erroneous determination is likely to occur.

  Therefore, the inventor focused on the d-axis voltage. The d-axis voltage is a manipulated variable of the q-axis current, and changes depending on the eccentricity state as the q-axis current. In addition, since it is an operation amount, it is difficult to be influenced by external noise, and the change as an absolute value is also large.

  However, since the d-axis voltage fluctuates more than the q-axis current, if the eccentricity state is determined depending only on the d-axis voltage, the possibility of an erroneous determination still remains.

  Based on such new findings, the present invention makes appropriate complementation in determining eccentricity with d-axis voltage, and in some cases eccentricity in place of d-axis voltage or equivalent or d-axis voltage It is an object of the present invention to realize a washing machine using a new determination method capable of performing the determination of the eccentricity state.

  In order to achieve the above object, the washing machine according to the present invention comprises a motor for rotationally driving a dewatering tank, and a control means for performing vector control of the generated torque of the motor, wherein the control means is It is characterized by comprising an eccentricity judgment unit which judges the eccentricity state of the dehydration tank by the magnitude of the phase error between the phase of the d axis estimated for performing vector control and the phase of the actual d axis. Do.

  In the washing machine according to the present invention, the washing machine according to the present invention comprises a motor for rotationally driving the dewatering tank, and a control means for vector control of the generated torque of the motor, wherein the control means estimates for performing the vector control. And an eccentricity determination unit that determines an eccentricity state of the dewatering tank based on the degree of change in phase error between the d-axis phase and the actual d-axis phase.

  In the washing machine according to the present invention, the washing machine according to the present invention includes a motor for rotationally driving the dewatering tank and a control means for vector control of the generated torque of the motor, wherein the control means generates the vector control. The decentered state of the dewatering tank according to the value obtained by correcting the d-axis voltage to be corrected by the load, and the correlation between the phase of the d axis estimated when performing the vector control and the phase error of the actual d axis. And an eccentricity determination unit for determining the eccentricity.

  Further, in the washing machine according to the present invention, in each of the above-described configurations, the value of the Fourier coefficient corresponding to the actual frequency among the Fourier series expanded with respect to the waveform of the phase error is used as the phase error. It features.

  The washing machine of the present invention determines the eccentricity state based on the magnitude of the phase error between the d-axis phase and the actual d-axis phase. The phase error does not fluctuate as much as the d-axis voltage, but increases or decreases depending on the eccentricity. Therefore, according to the present invention, it is possible to determine the eccentricity state from the viewpoint different from the case of monitoring the d-axis voltage. Therefore, when determining the eccentricity state by the d-axis voltage, it is possible to perform appropriate complementation, and in some cases, it is possible to determine the eccentricity state instead of the d-axis voltage equally or in place of the d-axis voltage. The phase error tends to be large at the time of acceleration in the low speed region.

  Further, the washing machine of the present invention determines the eccentricity state based on the degree of change in the phase error between the phase of the d axis and the phase of the actual d axis. The degree of change of the phase error does not fluctuate as much as the degree of change of the d-axis voltage, and becomes large depending on the eccentricity while excluding the influence of the load. Therefore, according to the present invention, it is possible to accurately determine the eccentricity state which accurately captures the eccentricity state changing from the viewpoint different from the case of monitoring the d-axis voltage and also from the viewpoint different from the magnitude of the phase error. it can. The phase error tends to change significantly during acceleration in the high speed region.

  Further, the washing machine of the present invention determines the eccentricity state by the correlation between the value obtained by correcting the d-axis voltage by the load and the phase error described above. Even when the d-axis voltage is corrected by the load, the d-axis voltage may be increased due to other factors, and the phase error does not greatly fluctuate at this time. Therefore, according to the present invention, the determination based on the d-axis voltage can be complemented by the phase error, and the eccentricity state can be determined more accurately. Another factor is the condition of so-called "water" in which water remains between the dewatering tank and the outer tank due to poor drainage.

  Further, the washing machine according to the present invention Fourier-transforms the waveform of the phase error to take out the phase error corresponding to the actual frequency, so that it is possible to eliminate noise and perform highly accurate determination.

BRIEF DESCRIPTION OF THE DRAWINGS The perspective view which shows the external appearance of the washing machine which concerns on one Embodiment of this invention. The longitudinal cross-sectional view which shows schematic structure of the washing machine. The block diagram which shows the system configuration of the motor control system used as the premise composition of load measurement in the embodiment. The figure which shows schematic structure of the speed estimation part in the motor control system. The figure which shows the speed estimation principle in the motor control system. The figure which shows the outline | summary of the PLL control part in the motor control system. The sequence diagram which shows the control process at the time of the spin-drying | dehydration process of the washing machine. The flowchart which shows the processing procedure of low speed territory decision 1 in the same embodiment. The flowchart which shows the processing procedure of low speed territory decision 2 in the same embodiment. The flowchart which shows the processing procedure of high speed zone decision 1 in the same embodiment. The flowchart which shows the processing procedure of high speed zone decision 2 in the same execution form. The graph which showed transition of the detected value of d axis voltage when low speed area | region determination 1 is not applied in area C by the case where eccentricity amount is small, and the case where eccentricity amount is large. The graph which showed transition of the phase error when the low speed area | region determination 2 is not applied in C area by the case where eccentricity amount is small, and the case where eccentricity amount is large. The graph which showed transition of the d-axis voltage in case D not apply the high speed area | region determination 1 in D area, and phase error (DELTA) (theta) in the case of small eccentricity amount, and the case of large eccentricity amount. The graph which showed transition of the d-axis voltage in case D not apply the high speed area | region determination 2 in D area, and phase error (DELTA) (theta) in the case of small eccentricity amount, and the case of large eccentricity amount.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a perspective view showing the appearance of a vertical washing machine (hereinafter referred to as a "washing machine") 1 according to an embodiment of the present invention. Moreover, FIG. 2 is a longitudinal cross-sectional view which shows schematic structure of the washing machine 1 of this embodiment.

  As shown in FIG. 2, the washing machine 1 of the present embodiment includes a washing machine main body 11, an outer tub 12, a dewatering tub (washing tub) 13, a drive unit 16, and control means C (see FIG. 3). Equipped with When such a washing machine 1 is in the input unit 14 and a start key (not shown) for performing automatic washing is pressed, the amount of laundry in the dewatering tank 13 is automatically determined as the load amount, and the load amount is The amount of water stored in the outer tub 12 in the washing step and the rinsing step is automatically determined based on the above, and the washing operation is performed. After that, in the dewatering process, it shifts to sensorless control after low speed rotation, and while monitoring the eccentricity state of the dehydration tank 13 sensorlessly, stops rotation in the case of eccentricity abnormality, and if there is no eccentricity abnormality, maximum speed Accelerate to

  FIG. 3 is a functional block schematically showing control means. The present embodiment includes the eccentricity determination unit 100 in the determination of the eccentricity state, and the eccentricity determination unit 100 uses the value of the d-axis voltage instead of the value of the q-axis current, and is estimated on control. The phase error Δθ between the d axis and the actual d axis is used. With respect to the Vd value and the Δθ value, processing for removing steeply changing data is performed by a low pass filter, moving average processing, or the like as necessary. The following will be described in order.

  The washing machine main body 11 has a substantially rectangular parallelepiped shape, and has an opening 11b for taking laundry (garment) into and out of the dewatering tank 13 on the upper surface 11a, and an open / close lid 11c capable of opening and closing the opening 11b. By opening the open / close lid 11c, the laundry can be taken in and out of the dehydration tank 13 through the opening 11b. Further, the above-mentioned input unit 14 is formed on the upper surface 11 a of the washing machine main body 11 as described above.

  The outer tank 12 shown in FIG. 2 is a cylindrical member with a bottom, which is disposed inside the washing machine main body 11 and capable of storing water.

  The dewatering tank 13 as the washing tank is a bottomed cylindrical member which is coaxially disposed with the outer tank 12 inside the outer tank 12 and rotatably supported by the outer tank 12. The dehydration tank 13 has a diameter smaller than that of the outer tank 12, and has a number of water flow holes (not shown) in its wall surface 13a.

  A pulsator (agitating blade) 15 is rotatably disposed at the center of the bottom portion 13 b of the dewatering tank 13. The pulsator 15 agitates the water stored in the outer tank 12 to generate a water flow.

  The pulsator 15 is also rotationally driven at the start of the washing step and before water supply to the dehydration tank 13, and the detected value obtained by the rotation dragging the laundry at this time detects the load amount Used for

  Drive unit 16 includes a motor M and a clutch 16b. The motor M rotates the dewatering tank 13 by rotating a drive shaft m extending toward the bottom 13 a of the dewatering tank 13. Further, the motor M can give a driving force to the pulsator 15 by switching the clutch 16b, and can rotate the pulsator 15. Therefore, the washing machine 1 can rotate only the pulsator 15 mainly in the washing process and the rinsing process at the time of measuring the load amount to be described later, and can rotate the dewatering tank 13 and the pulsator 15 integrally at high speed in the dewatering process.

The following is the voltage equation of a permanent magnet synchronous motor. Only in this equation, each velocity ω is represented as ωe.
... (1)

In this equation, assuming steady rotation and ignoring differential terms,
Vd = R.Id.-L.Lq.iq (2)
Vq = ω · Ld · id + R · iq + ω · Φ (3)

Furthermore, if ω is large and the voltage drop due to R is negligible, then
Vd = −ω · Lq · iq (4)
Vq = ω · Ld · id + ω · ... (5)

If flux-weakening control has not started, control is usually performed with id 0 0.
Vq ω ωΦ (6)

  Although it is also described in Patent Document 1 that iq depends on the eccentricity state, the state change of the d-axis voltage Vd, which is the manipulated variable of the q-axis current Iq, is also It depends on eccentricity.

  In particular, the d-axis voltage Vd is a control operation amount, and does not appear as a result of control as in the q-axis current Iq. Therefore, in this embodiment, the eccentricity state is determined using the d-axis voltage Vd.

  However, as a disadvantage compared to the case of using the q-axis current Iq, the fluctuation tends to be large. Therefore, when determining eccentricity, it is necessary to use values obtained by arithmetic processing as integrated values or average values, instead of using instantaneous values, and between the d axis estimated for control and the actual d axis The phase error Δθ is also added to the judgment factor. The phase error Δθ is a state in which the phase of the three-phase applied voltage is shifted with respect to the actual phase of the dehydration tank 13, and the control system controls the phase error Δθ to be 0, but the phase error Δθ converges. If not, it can be said that large eccentricity and vibration occur. That is, the phase error can be treated as a parameter reflecting eccentricity.

  Therefore, the eccentricity determination unit 100 determines the eccentricity state based on the magnitude of the phase error Δθ and the change degree of the phase error Δθ. Alternatively, the eccentricity determination unit 100 may calculate a value obtained by correcting the d-axis voltage with a load, and a phase error Δθ between the d-axis phase estimated when the torque control means performs vector control and the actual d-axis phase. The eccentricity state is determined based on the correlation with.

  As a result, it is possible to supplement or substitute for the defect when using the d-axis voltage Vd which is not easily influenced by the disturbance but has a large fluctuation, and can lead to an appropriate judgment result.

  FIG. 3 is a sensorless vector control block diagram showing the control means C according to the present invention, and the d-axis voltage Vd for determining the eccentricity state and the phase error Δθ are calculated in this control block. First, this control block will be described.

The basic configuration of the control means C includes a torque command generation unit 2 that generates a torque command based on a deviation between a motor rotational speed command value ω ^* _m given as a control amount and a motor rotational speed estimated value ω _m ; The deviation between the motor current Iq (Id) and the current command value Iq ^* (Id) corresponding to the torque command value T ^* is converted into motor voltage command values V ^* q and V ^* d which are control manipulated variables, and the motor M To estimate the motor rotational speed ω _m and the phase error Δθ using the motor drive control unit 3 for driving the motor, the motor currents Iq and Id and the motor voltages Vq and Vd related to the motor voltage command values V ^* q and V ^* d. The estimator 4 is configured in the feedback loop 5. The torque command generator 2 and the motor drive controller 3 are components of an inverter controller generally referred to. In addition, here, it is treated that the motor voltages Vq and Vd equal to the motor voltage command values V ^* q and V ^* d are generated.

The torque command generation section 2, first subtracter 21, and inputs the estimated speed value omega _m estimated from the rotational speed command omega ^* m and a motor drive state given from the microcomputer 6 for controlling the operation in general of the washing machine 1. The differential output of the subtractor 21 is input to the speed controller 22.

Speed controller 22, to control the rotational speed of the motor M to the target value, and generates a torque command T ^* by the PI control based on the difference amount between the rotation speed command omega ^* _m and estimated speed omega _m.

The torque command T ^* generated by the torque command generation unit 22 is input to the motor drive control unit 3.

  The motor drive control unit 3 performs voltage drive under the coordinate system (d, q) of the magnetic poles rotating with the rotation of the rotor of the synchronous motor M.

First, the torque command value T ^* is a q-axis current command value Iq ^* by a torque coefficient 1 / K _E is multiplied by the gain multiplication unit 31, is input to the q-axis current controller 33 via the subtractor 32 . In general, the d-axis current command unit 34 outputs a command value Id = 0, which is input to the d-axis current controller 36 via the subtracter 35. The subtracter 32 is supplied with a q-axis current value Iq output from a second converter 51 described later which performs [uvw → dq] conversion as a subtraction value, and the subtracter 35 is set to the second one. The d-axis current value Iq output from the converter 51 is given as a subtraction value.

The q-axis current controller 33 generates a q-axis voltage command value Vq ^* by performing PI control based on the difference between the q-axis current command value Iq ^* and the q-axis current value Iq. The d-axis current controller 36 generates a d-axis voltage command value Vd ^* by performing PI control based on the difference between the d-axis current command value Id ^* (= 0) and the q-axis current value Iq. Then, the signal is input to a first converter 37 that performs [dq → uvw] conversion to convert it into a three-phase voltage command.

The first converter 37 is provided with an estimated rotor rotational phase angle θ obtained by integrating the motor electrical angular velocity ω _e output from the estimator 4 described later by the integrator 44. Then, q and d voltage command values Vq ^* and Vd ^* are converted into three-phase voltage command values Vu, Vv and Vw based on the estimated rotor rotational phase angle θ, and the motor M is energized via the motor excitation circuit 38.

On the other hand, the feedback loop 5 detects the phase currents Iu, Iv, Iw through the phase current detection unit 50 provided in the motor excitation circuit 38, and carries out a second conversion that performs [uvw → dq] conversion. Input to the storage unit 51. The second converter 51 is provided with an estimated rotor rotational phase angle θ obtained by integrating the motor electrical angular velocity ω _e output from the estimator 4 described later by the integrator 44, thereby setting the phase current value q, Convert into d-axis current values Id and Iq. These q and d axis current values are input to the subtractors 35 and 32, respectively.

On the other hand, the estimator 4 is composed of a rotor phase error estimator 41 and a PLL (Phase Locked Loop) controller 42 as shown in FIG. The rotor phase error estimator 41 uses the motor voltages Vd (= Vd ^* ) and Vq (= Vq ^* ), the motor currents Id and Iq, the motor parameters R, L, and the like to calculate the estimated phase error Δθ. R is a motor winding resistance, and L is a motor winding inductance.

  When the motor M is a permanent magnet synchronous motor, as shown in the coordinate system of FIG. 5, the rotor rotates at the electrical angular velocity ωn in the dq rotational coordinate system with respect to the stationary coordinate systems α and β. On the other hand, a rotational speed estimation algorithm generally called a sensorless algorithm estimates rotational coordinates of γ-δ. Although the magnetic pole is actually on the d-axis, when it is estimated that the magnetic pole is on the γ-axis, a phase error of Δθ is generated between the estimated d-axis and the actual d-axis.

And the estimator 41 has the following formula as an example,
Δθ = tan ⁻¹ {(Vd−R · Id + ω _γ · L · Iq) / (Vq−R · Iq−ω _γ · Li · d)} (7)
The phase error Δθ is calculated based on

  In order to turn the motor M stably, it is necessary to locate the dq axes and match the r-δ axes recognized by the control means 1. That is, it is necessary to aim at Δθ → 0.

  Therefore, the PLL controller 42 is used. The contents of this PLL controller 42 are shown in FIG.

The PLL controller 42 uses PI control. ω _γ is the angular velocity (angular frequency) of the three-phase voltage applied to the motor by the motor drive controller 3. Naturally, the motor drive controller 3 can output a free value by the inverter method. As seen in FIG. 5, as ω _γ increases, Δθ → increases due to the speed difference with ω _n, and Δθ decreases as ω _γ decreases.

  FIG. 7 shows the sequence from the start at the time of dehydration, with time on the horizontal axis and rotation speed on the vertical axis. Synchronous rotation control is performed in the A section, and after synchronization is completed in the B section, the process shifts to sensorless vector control in the C section and D section. The section C is operated in the low speed mode, and the section D is operated in the high speed mode.

  As described above, this embodiment uses the d-axis voltage input to the estimator 4 shown in FIG. 3 and the phase error Δθ estimated by the estimator 4. The d-axis voltage Vd and the phase error Δθ are updated for each carrier frequency which is the basic frequency of control, but in the current detection, the d-axis voltage V and the phase error Δθ are extracted from the estimator 4 every predetermined period of time And input to the eccentricity determination unit 100.

  The eccentricity determination unit 100 is configured to execute a program and data for performing eccentricity determination in advance using the d-axis voltage Vd and the phase error Δθ. The eccentricity determination in this eccentricity determination unit 100 is performed in parallel in low speed region determination 1 and low speed region determination 2 in section C, high speed region determination 1 is performed from the first half in section D, and ultra high speed region determination from the second half Two are executed in parallel.

  FIGS. 8 to 11 are flowcharts showing a processing procedure of eccentricity determination performed by the eccentricity determination unit 100 for each section.

(Low speed zone judgment 1)
First, the processing procedure of the low speed range determination 1 will be described based on FIG.
Enter section C and start judgment flow with acceleration started.

<Step S11>
First, in step S11, the eccentricity determination unit 100 measures the maximum value of the Vd value. Since the Vd value is approximately proportional to the load amount, the Vd value can be estimated as the load amount.

<Step S12>
When the measurement of the maximum value of the Vd value is completed, the eccentricity determination unit 100 integrates the Vd value after a predetermined time.

<Step S13>
Next, the eccentricity determination unit 100 corrects the integrated value with the maximum value calculated in step S11, that is, the load amount. For example, assuming that the integrated value is Vd _int , the maximum value is Vd _max , the counter value of the measurement counter is CT, and the load amount correction value is Vd _amd ,
Vd _amd = Vd _int + (30-Vd _max ) x 0.3 x (CT-40) (8)
Calculate as The counting of CT starts at the time of step S11, and after acquiring the maximum value Vd _max at CT (0 to 40), step S13 is performed at CT> 40. As a result, a value obtained by multiplying the integrated value Vd _int including the amount of load by the coefficient obtained by multiplying the maximum value Vd _{max including the} amount of load by a factor is partially canceled.

<Step S14>
The eccentricity determination unit 100 compares the load amount correction value Vd _amd calculated in step S13 with a preset threshold value. Then, if the load amount correction value Vd _amd is equal to or greater than the threshold value, it is determined that the eccentricity amount is large and the process proceeds to step S15. If less than the threshold value, step S15 is skipped and the process ends.

<Step S15>
In step S15, the eccentricity determination unit 100 issues a spin-off instruction to stop the spin-drying tank and the process ends. This command interrupts the dewatering sequence and stops the rotation. In the rotation stop, necessary processing is performed such as setting the rotation speed command ω ^* m shown in FIG. 4 to 0 and applying mechanical braking by a brake mechanism (not shown). The same applies below.

  Usually, when the amount of eccentricity is small, the Vd value decreases rapidly after the maximum value appears. For this reason, the values after the processes of steps S12 and S13 become low. However, when the eccentricity amount is large, the decrease of the Vd value becomes small. Therefore, the values after the processes in steps S12 and S13 will exceed the threshold.

(Low speed zone judgment 2)
Next, the processing procedure of the low speed range determination 2 will be described based on FIG. The flow of FIG. 9 is started at any time and repeatedly executed from the time when acceleration is started in section C.

<Step S21>
First, the eccentricity determination unit 100 measures the phase error Δθ.

<Step S22>
Next, the eccentricity determination unit 100 compares the phase error Δθ with a preset threshold. If the phase error Δθ is equal to or greater than the threshold value, the process proceeds to step S23. If the phase error Δθ is less than the threshold value, step S23 is skipped.

<Step S23>
Here, the eccentricity determination unit 100 issues a spin-off instruction to stop the spin-drying tank and ends the process. This command interrupts the dewatering sequence to stop dewatering.

  For this reason, even if the fluctuation of the Vd value appears small in the flowchart of FIG. 8 and the eccentric abnormality is overlooked, the eccentricity state can be reliably determined by complementing with θ in the flowchart of FIG. 9. it can.

(High-speed range judgment 1)
Next, the processing procedure of the high speed area determination 1 will be described based on FIG. In FIG. 10, first, after performing the procedure along the flowchart of (a), the procedure along the flowchart of (b) is performed.

<Step S31>
In the procedure of (a), the eccentricity determination unit 100 starts as needed after entering the D section, and determines whether the number of rotations has reached a predetermined number of rotations, for example, 400 rpm. If YES, the process proceeds to step 32, and if NO, the determination of step S31 is repeated.

<Step S32>
Here, the eccentricity determination unit 100 measures, stores, and ends the Vd value. Once this step S32 is performed, the procedure of (a) may not be performed. The measurement of the Vd value at this 400 rpm time is an estimated value of the load amount, and it is set based on the number of rotations at which the rotation is stabilized beyond the resonance rotation number and the load amount can be estimated without being affected by the eccentricity load. Yes.

  However, if there is a possibility that the error may increase if it is judged only by the Vd value only once, the average of the determined sections in step S32, for example, the average value of the Vd values between 400rpm and 500rpm while changing You may use Also, the number of revolutions does not have to be 400 to 500 rpm.

  Subsequently, the eccentricity determination unit 100 starts the procedure of FIG. Here, the eccentricity amount is determined based on the difference between the Vd value measured at any time and the Vd value regarded as the previous load amount.

<Step S41>
First, the eccentricity determination unit 100 determines whether or not the number of revolutions has reached 500 rpm in step S41. If YES, the process proceeds to step S42. If NO, the determination of step S41 is repeated.

<Step S42>
Here, the eccentricity determination unit 100 measures the Vd value. If there is a possibility that the error may increase if this measurement is judged by only one Vd value, the average of the finished section in step S42, for example, the Vd value between 500 and 550 rpm while changing by 50 rpm You may measure and use the average value. Then, the process proceeds to step S43.

<Step S43>
The eccentricity determination unit 100 calculates the difference between the Vd value measured in step S42 and the Vd value regarded as the load amount, and compares this difference with a preset threshold value. Then, if the difference is equal to or more than the threshold value, the rotation stop command is not issued immediately but the process proceeds to step S44, and if less than the threshold value, the process ends.

<Step S44>
Here, the eccentricity determination unit 100 measures the phase error Δθ. The phase error Δθ may also be measured a plurality of times and taken as an average value, instead of being measured only once. In this case, the same processing as the Vd value described above may be performed. Since the phase error Δθ changes less than the d-axis voltage Vd, the phase error Δθ tends not to require an average of as many values as the d-axis voltage Vd. Alternatively, the value of the Fourier coefficient corresponding to the actual frequency (rotational speed) of the Fourier series expanded with respect to the phase error waveform may be used as the phase error Δθ. By using the values of the Fourier coefficients, it is possible to eliminate noise and make highly accurate determinations. Then, the process proceeds to step S45.

<Step S45>
In step S45, the eccentricity determination unit 100 determines whether the phase error Δθ is equal to or greater than a threshold. If it is equal to or greater than the threshold value, it is treated as large eccentricity, and the process proceeds to step S46. The state of water retention refers to a state in which drainage is bad as described above, and water remains between the dehydration tank and the outer tank.

<Step S46>
In step S46, the eccentricity determination unit 100 issues a rotation stop command of the dehydration stop tank and ends. The rotation stop command interrupts the dewatering sequence to stop the dewatering process.

<Step S47>
In step S47, the eccentricity determination unit 100 issues an instruction to maintain a predetermined number of revolutions for a predetermined time, and ends. This command interrupts the dewatering sequence, maintains a predetermined number of revolutions for a certain period of time, and raises the number of revolutions after that time. When the rotation speed is increased in the water clamp condition, the water clamp condition is further deteriorated. Therefore, the increase in the rotation rpm is stopped, and the predetermined rotation speed is maintained to promote drainage.

  As described above, since the eccentricity state is determined by the correlation between the d-axis voltage Vd and the phase error Δθ, an unnecessary stop command can be avoided.

(High-speed range judgment 2)
Next, the processing procedure of the high speed area determination 1 will be described based on FIG. In FIG. 11, first, the procedure along the flowchart of (a) is performed, and then the procedure along the flowchart of (b) is performed.

<Step S51>
In the procedure of (a), the eccentricity determination unit 100 starts as needed after entering the D section, and determines whether or not the number of revolutions has reached a predetermined number of revolutions, for example, 1000 rpm. If YES, the process proceeds to step 52. If NO, the determination of step S61 is repeated.

<Step S52>
Here, the eccentricity determination unit 100 measures, stores, and ends the Vd value and the θ value. Once this step S52 is performed, the procedure of (a) may not be performed. When the rotational speed goes from 1000 rpm to the ultra high speed rotation range, the influence of the eccentric load becomes greater than that at normal high speed rotation. Therefore, the above value at 1000 rpm is set as a reference at the entrance toward the super high speed rotation range.

However, if there is a possibility that the error may become large if it is judged only by the Vd value or θ value only once, the same average value as described above may be used.
Subsequently, the eccentricity determination unit 100 starts (b) every two seconds as needed. Here, Vd and θ are measured at any time, and the eccentricity amount is determined based on the difference between the reference Vd value and the θ value at 1000 rpm.

<Step S61>
First, the eccentricity determination unit 100 waits in step S61 whether or not a predetermined time has elapsed from the start. If YES, the process proceeds to step S62. If NO, the determination of step S61 is repeated.

<Step S62>
Here, the eccentricity determination unit 100 measures the Vd value and the θ value. Also in this measurement, if there is a possibility that the error may become large if it is judged by only one Vd value, an average value similar to the above may be used. Then, the process proceeds to step S63.

<Step S63>
Here, the eccentricity determination unit 100 calculates the difference between the Vd value measured in step S52 and the Vd value measured every two seconds in step S62, and compares this difference with a preset threshold value. Then, if it is equal to or more than the threshold value, the process proceeds to step S64, and if it is less than the threshold value, the process does not immediately end but proceeds to step S65.

<Step S64>
Here, the eccentricity determination unit 100 considers that the eccentricity amount is large, issues a rotation stop command of the dewatering tank, and ends. This command interrupts the dewatering sequence to stop dewatering.

<Step S65>
Here, the eccentricity determination unit 100 calculates the difference between the Δθ value measured in step S52 and the Δθ value measured every two seconds in step S62, and compares this difference with a preset threshold value. And when it is more than a threshold value, it moves to said step S64, and when less than a threshold value, it is ended.

  As described above, the degree of change of the d-axis voltage Vd and the degree of change of the phase error Δθ are monitored, and if any one is equal to or more than the threshold, it is treated as eccentricity abnormality. It is possible to make a judgment that you have captured.

  FIG. 12 is a graph showing the transition of the detected value of the d-axis voltage in the case where the low speed range determination 1 is not applied in the C section, in the case of the small eccentricity amount and in the case of the large eccentricity amount. FIG. 13 is a graph showing the transition of the phase error Δθ when the low speed range determination 2 is not applied in the C section in the case of the small eccentricity amount and the case of the large eccentricity amount. FIG. 14 is a graph showing transitions of the d-axis voltage and the phase error Δθ when the high speed range determination 1 is not applied in the D section in the case of small eccentricity amount and in the case of large eccentricity amount. Among the graphs of FIG. 14, the upper graph is at 10 kg load, and the middle graph is at 1 kg load. FIG. 15 is a graph showing transitions of the d-axis voltage and the phase error Δθ when the high speed range determination 2 is not applied in the D section in the case of the small eccentricity amount and in the case of the large eccentricity amount.

  In any case, by applying the present invention, the magnitude and the change degree of the phase error Δθ between the phase of the d axis and the actual phase, or the phase error Δθ and the d axis voltage Vd are corrected by the load. Since the method of determining the eccentricity state by the correlation with the value is used in combination or complemented, the eccentricity state can be accurately determined.

  As mentioned above, although one Embodiment of this invention was described, the specific structure of each part is not limited only to embodiment mentioned above.

  For example, the procedure shown in the flowcharts of FIGS. 8 and 9 may be performed in the D section, or the procedure shown in the flowcharts of FIGS. 10 and 11 may be performed in the C section.

  Also, various methods other than the above can be used as a method of estimating the phase error.

  Other configurations can be variously modified without departing from the spirit of the present invention.

100 Eccentricity determination unit A4 Dehydration tank M Motor Vd d-axis voltage Vd _amd Load amount correction value Δθ Phase error between estimated d-axis phase and actual d-axis phase

Claims (4)

In a motor comprising a motor for rotationally driving the dewatering tank, and a control means for vector controlling the generated torque of the motor,
The control means includes an eccentricity determination unit which determines an eccentricity state of the dehydration tank based on the magnitude of the phase error between the phase of the d axis estimated to perform the vector control and the phase of the actual d axis. Washing machine characterized by having. In a motor comprising a motor for rotationally driving the dewatering tank, and a control means for vector controlling the generated torque of the motor,
The control means includes an eccentricity determination unit that determines an eccentricity state of the dehydration tank based on the degree of change in phase error between the d-axis phase estimated to perform the vector control and the actual d-axis phase. Washing machine characterized by having. In a motor comprising a motor for rotationally driving the dewatering tank, and a control means for vector controlling the generated torque of the motor,
The control means is a value obtained by correcting the d-axis voltage generated when performing the vector control with a load, and a phase between the d-axis phase estimated when performing the vector control and the actual d-axis phase A washing machine comprising: an eccentricity determination unit which determines an eccentricity state of the dewatering tank based on a correlation with an error. The washing machine according to any one of claims 1 to 3, wherein a value of a Fourier coefficient corresponding to an actual frequency out of Fourier series expansion of a waveform of a phase error is used as the phase error.