washing machine

Abstract

The control unit of the washing machine disclosed in the present invention is capable of executing a sensorless open-loop acceleration control process as a first control process, and a sensorless phase estimation control process as a second control process, wherein the first control process performs energization regardless of the position of the permanent magnet (4d) relative to the winding (4a, 4b, 4c), and the second control process performs energization corresponding to the position of the permanent magnet (4d) relative to the winding (4a, 4b, 4c). In addition, the control device is capable of executing a sensorless phase estimation control process as a lock detection process, wherein the lock detection process detects that the permanent magnet (4d) is locked when it does not rotate at a specified speed after transferring from the first control process to the second control process. Furthermore, when the control unit detects that the motor (4) is locked in the lock detection process, when starting driving based on the first control process, phase fixing control of different phases is performed multiple times.

Description

Technical Field

[0001] The present disclosure relates to a washing machine. Background Art

[0002] In the past, this type of washing machine detected the rotational position of the motor as follows. Rotational position detection refers to using a Hall element, a rotary encoder, etc. as a rotation sensor by detecting the electrical angle of the motor. However, due to cost and structural constraints, when a rotation sensor cannot be provided, there is a method of performing rotational position detection in a sensorless manner without providing a rotation sensor, a method using an induced voltage, and a method using an inductor.

[0003] When using the induced voltage, the induced voltage proportional to the motor rotation speed is calculated from the input voltage and current input to the motor, and the rotation position is detected based on the induced voltage. With respect to this detection method, in the area where the motor rotation speed is high, the induced voltage is large, so the rotation position can be detected with good accuracy, but in the area where the motor rotation speed is low, the induced voltage is small, so the rotation cannot be detected correctly when starting or stopping.

[0004] In addition, when using inductance, the inductance of the motor is calculated from the input voltage and current input to the motor, and the rotation position is detected by using the fact that the inductance variation period is twice the motor electrical angle. This detection method is limited to motors with magnetic salient polarity, and voltage is applied to the motor at a period different from the motor rotation period (for example, refer to Patent Document 1).

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2001-169590 Summary of the invention

[0008] However, in this conventional washing machine, it is difficult to estimate the phase in the low speed region for a motor having a magnetically hidden polarity, so a control method that does not feed back phase information is used. In this case, there is a problem that the torque cannot be correctly transmitted to the motor due to the inaccurate phase, so the start fails and the machine becomes locked. In addition, there is a problem that even if the machine is restarted in the same way by the start method in order to unlock the machine, the machine cannot be unlocked and started.

[0009] The present disclosure provides a washing machine which can easily eliminate the locked state by changing the starting method when the starting fails and thus becomes locked.

[0010] The washing machine disclosed in the present invention comprises: a rotating object that contacts the laundry; a motor that has a permanent magnet and a winding; a power circuit that supplies current to the motor; a transmission mechanism that transmits the torque of the motor to the rotating object; and a control unit that performs a washing operation. In addition, the control unit is capable of performing a first control process, wherein the first control process performs energization regardless of the position of the permanent magnet relative to the winding, and a second control process, wherein the second control process performs energization corresponding to the position of the permanent magnet relative to the winding. Furthermore, the control unit is capable of performing a lock detection process, wherein the lock detection process detects that the permanent magnet is locked when it does not rotate at a specified speed after transferring from the first control process to the second control process. Then, when the control unit detects lock in the lock detection process, when starting to drive based on the first control process, it performs phase fixing control of different phases multiple times.

[0011] The washing machine of the present disclosure can easily eliminate the locked state by changing the starting method when the starting fails and becomes locked. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a cross-sectional view of the main parts of the washing machine in the first embodiment.

[0013] Figure 2 This is a block diagram of a driving system of a motor of the washing machine in the first embodiment.

[0014] Figure 3 It is an equivalent circuit diagram of the motor of the washing machine in the first embodiment.

[0015] Figure 4 This is a control block diagram when estimating the phase of the motor of the washing machine in the first embodiment.

[0016] Figure 5 This is a detailed block diagram of a speed phase estimation unit of a motor of a washing machine according to the first embodiment.

[0017] Fig. 6A This is a vector diagram showing that the estimated coordinates are in a delayed state when estimating the phase of the motor of the washing machine in the first embodiment.

[0018] Figure 6B This is a vector diagram showing that the estimated coordinates are in an advanced state when estimating the phase of the motor of the washing machine in the first embodiment.

[0019] Figure 7 This is a control block diagram of the motor of the washing machine in the open loop state according to the first embodiment.

[0020] Fig. 8A This is a flowchart of the sensorless control process of the motor of the washing machine in the first embodiment.

[0021] Figure 8B This is a flowchart of another sensorless control process of the motor of the washing machine in the first embodiment.

[0022] Fig. 9 This is a flowchart of the sensorless open-loop acceleration control process of the motor of the washing machine in the first embodiment.

[0023] Fig.10 This is a vector diagram of the initial phase fixing control of the sensorless open-loop acceleration control of the motor of the washing machine in the first embodiment.

[0024] Fig.11 1 is a graph showing the command rotation speed of the sensorless open-loop acceleration control of the motor of the washing machine in the first embodiment.

[0025] Fig.12 This is a flowchart of the sensorless phase estimation control process of the motor of the washing machine in the first embodiment.

[0026] Fig.13 This is a flowchart of the speed control process of the motor of the washing machine in the first embodiment. DETAILED DESCRIPTION

[0027] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, the present disclosure is not limited to the embodiments.

[0028] (First Embodiment)

[0029] Figure 1 It is a cross-sectional view of the main parts of the washing machine in the first embodiment.

[0030] The washing and dehydrating tank 2 is rotatably disposed inside the water receiving tank 3, and a pulsator 1 for stirring clothes is rotatably disposed at the bottom of the washing and dehydrating tank 2. The motor 4 is fixed to the outer bottom of the water receiving tank 3, and the rotation of the motor 4 is driven to rotate or brake the pulsator 1 or the washing and dehydrating tank 2 via the motor pulley 31, the belt 5, the impeller pulley 32 and the speed reduction mechanism and clutch 6 to stop the pulsator 1 or the washing and dehydrating tank 2. Regarding braking, in addition to the method of controlling the motor 4 to apply reverse torque, there is also a method of mechanically braking the washing and dehydrating tank 2 by operating the gear transmission motor 7 to make the brake belt 8 contact the rotating part. On the upper surface of the panel part 10 disposed above the outer frame 9 of the washing machine, a cover 11 is freely opened and closed, and a control device 13 is disposed in the front inner side of the panel. The control device 13 controls all the processes of the washing machine and has a display part 12.

[0031] The control device 13 controls the actions of the motor 4, the water supply valve 14, the drain valve 15, etc., and is composed of a control unit 20 composed of a microcomputer that sequentially controls a series of processes such as washing, rinsing, and dehydration. The control unit 20 displays the process progress or displays various information to notify the user through a display unit 12 composed of light-emitting elements such as LEDs and LCDs based on information from the input setting unit that the user operates the desired washing process setting, operation start, temporary stop, etc. When the operation start is set by the input setting unit, the gear transmission motor 7, the water supply valve 14, and the drain valve 15 are controlled according to data from the water level detection unit, so that the washing operation is performed.

[0032] Figure 2 This is a block diagram of a driving system of a motor of the washing machine in the first embodiment.

[0033] The AC power supply applies AC power to the rectifier circuit 16, and the rectifier circuit 16 is composed of a voltage doubling rectifier circuit, and applies the doubled DC voltage to the inverter circuit 17. The inverter circuit 17 is composed of a 3-phase full-bridge inverter circuit composed of 6 power switch semiconductors and anti-parallel diodes. The 3-phase full-bridge inverter circuit is usually composed of an intelligent power module (hereinafter referred to as IPM) with an insulated gate bipolar transistor (IGBT), an anti-parallel diode and its drive circuit and protection circuit built in. In addition, the motor 4 is connected to the output terminal of the inverter circuit 17 to drive the motor 4.

[0034] The current detection unit 18 connects a shunt resistor between the negative voltage terminal of the inverter circuit 17 and the negative voltage terminal of the rectifier circuit 16, and detects the phase currents Iu, Iv, and Iw of the motor 4 based on the input current of the inverter circuit 17 calculated from the voltage across the shunt resistor. The DC voltage applied to the inverter circuit 17 is sometimes superimposed with the regenerative energy generated by the rotation of the motor in addition to the input from the AC power supply, so detection is always performed.

[0035] The PWM control unit 19 controls a PWM signal for switching the IGBTs of the inverter circuit 17 based on the three-phase motor drive control voltage instructions Vus, Vvs, and Vws from the control unit 20, and drives the motor 4 with the output voltages Vu, Vv, and Vw of the inverter circuit.

[0036] Figure 3 It is an equivalent circuit diagram of the motor of the washing machine in the first embodiment.

[0037] Here, for simplicity of explanation, it is assumed that a two-pole structure is such that one revolution of mechanical angle rotation results in one revolution of electrical angle rotation. In the case where the number of poles changes to 4 poles, 8 poles,..., the relationship becomes such that one revolution of mechanical angle rotation results in two revolutions, four revolutions,... of electrical angle rotation. The motor 4 is a three-phase synchronous motor and is constituted by an equivalent circuit having three-phase windings 4a, 4b, and 4c with U, V, and W and a permanent magnet 4d as a rotor that rotates about the center of the rotation axis. In this equivalent circuit, the axis passing through the N-pole side of the permanent magnet in the positive direction is defined as the d-axis (direct-axis), and the axis orthogonal to the d-axis is defined as the q-axis (quadrature-axis). When defined in this way, the magnetic field in the q-axis direction mainly dominates the torque of the motor. In addition, the phase (electrical angle) is the rotation angle θ between the axis passing through the U-phase winding and the d-axis. All phases described below are electrical angles. Further, the inductance of the winding when a voltage is applied in such a way as to generate a magnetic field in the d-axis direction is denoted as Ld, and similarly, the inductance related to the q-axis direction is denoted as Lq.

[0038] The buried magnet type three-phase synchronous motor is in the relationship of Ld < Lq. In addition, as shown later, since the control unit 20 cannot accurately detect the position of the rotor at the beginning, it is assumed that there is an error Δθ between the phase θc and the actual phase θ. That is, the axes with respect to which the microcomputer performs control assuming the phase θc become the γ-axis (estimated d-axis) and the δ-axis (estimated q-axis) with respect to the actual d-axis and q-axis of the motor. Thereafter, the current component corresponding to the torque in the microcomputer is denoted as the δ-axis current Iδ, the current component corresponding to the magnetic flux in the microcomputer is denoted as the γ-axis current Iγ, the voltage component corresponding to the torque in the microcomputer is denoted as the command δ-axis voltage Vδs, and the voltage component corresponding to the magnetic flux in the microcomputer is denoted as the command γ-axis voltage Vγs. Figure 3 is a control block diagram at the time of phase estimation of the motor of the washing machine in the first embodiment.

[0039] Figure 4

[0040] The control unit 20 includes a microcomputer (μC), an inverter control timer (timer) built in the microcomputer, A / D conversion, and a memory circuit. In addition, the control unit 20 includes a speed phase estimation unit 21, a three-phase to two-phase converter 22, an Iδ error amplifier 23, an Iγ error amplifier 24, a two-phase to three-phase converter 25, a speed error amplifier 26, a weak magnetic field setting unit 27, etc., and performs inverter control as follows.

[0041] The details of the speed phase estimation unit 21 are described later. The speed phase estimation unit 21 takes the δ-axis current Iδ, the γ-axis current Iγ, and the command γ-axis voltage Vγs as inputs and outputs the speed (electrical angular speed) ω and the estimated phase θ. All speeds described below are electrical angular speeds.

[0042] As shown in equation 1, the three-phase to two-phase converter 22 calculates the γ-axis current Iγ and the δ-axis current Iδ based on the electrical angle θ, the phase currents Iu, Iv, Iw, and the sine wave data (sin, cos data) required for converting from the stationary coordinate system to the rotating coordinate system.

[0043] [Number 1]

[0044]

[0045] The Iδ error amplifier 23 receives the error ΔIδ of the δ-axis current relative to the command value Iδs based on the δ-axis current command Iδs obtained by the speed error amplifier 26 and the δ-axis current Iδ obtained by the 3-phase 2-phase converter 22, and outputs a command δ-axis voltage Vδs which is the sum of the proportional component and the integral component.

[0046] Similarly, the Iγ error amplifier 24 receives the error ΔIγ of the γ-axis current relative to the command value Iγ based on the γ-axis current command Iγs obtained by the weak magnetic field setting unit 27 and the γ-axis current Iγ obtained by the 3-phase 2-phase converter 22, and outputs a command γ-axis voltage Vγs which is the sum of a proportional component and an integral component.

[0047] Since the current is decomposed into the δ-axis current Iδ and the γ-axis current Iγ and controlled independently, it is called vector control.

[0048] As shown in Formula 2, the 2-phase to 3-phase converter 25 calculates the sinusoidal command 3-phase voltages Vus, Vvs, and Vws based on the phase θ, the command δ-axis voltage Vδs, the command γ-axis voltage Vγs, and the sinusoidal wave data (sin, cos data) required for inverse transformation from the rotating coordinate system to the stationary coordinate system.

[0049] [Number 2]

[0050]

[0051] The speed error amplifier 26 receives an error Δω with respect to the speed command ωs based on the speed command ωs and the speed ω calculated by the speed phase estimation unit 21 , and outputs a δ-axis current command Iδs which is the sum of a proportional component and an integral component.

[0052] The field weakening setting unit 27 calculates a negative γ-axis current command Iγs based on the speed ω calculated by the speed phase estimation unit 21 and the DC voltage Vdc input to the inverter circuit, and performs flux weakening control.

[0053] Figure 5 This is a detailed block diagram of a speed phase estimation unit of a motor of a washing machine according to the first embodiment.

[0054] The estimated phase θ is calculated using the resistance value Ra and the inductance value L of the windings 4 a , 4 b , 4 c as parameters of the motor 4 .

[0055] The speed phase estimation unit 21 is composed of a γ-axis induced voltage calculator 28 and a γ-axis induced voltage error amplifier 29 .

[0056] As shown in Formula 3, the γ-axis induced voltage calculator 28 calculates the γ-axis induced voltage Veγ based on the inductance value L, the resistance value Ra, the δ-axis current Iδ, the γ-axis current Iγ, the command γ-axis voltage Vγs, and the estimated speed ω.

[0057] [Number 3]

[0058] V eγ =V γs -(R a ×I γ -ω×L×I δ )

[0059] Assuming that the γ-axis induced voltage command Veγs=0, the error ΔVeγ with respect to the γ-axis induced voltage command Veγs is input to the γ-axis induced voltage error amplifier 29 .

[0060] The γ-axis induced voltage error amplifier 29 outputs the estimated speed ω calculated by the integral gain Kω, adds the estimated speed ω to the value calculated by the proportional gain Kθ, and performs time integration by an integrator to output the estimated phase θ.

[0061] However, the γ-axis induced voltage calculator 28 is not limited to using the equation 3, and may perform calculation using the equation 4 in which a time differential term is added.

[0062] [Number 4]

[0063] V eγ =V γs -(R a ×I γ +L×(dI γ / dt)-ω×L×I δ )

[0064] In addition, regarding the inductance L in the above-mentioned formulas, the same L value can be used if the motor 4 has the characteristic of Ld=Lq, but even if the motor 4 has Ld≠Lq, it can be calculated by setting a fixed L value (=Lq).

[0065] Fig. 6A This is a vector diagram showing that the estimated coordinates during phase estimation of the motor of the washing machine in the first embodiment are in a delayed state (the γδ coordinates (estimated dq coordinates) are slightly delayed relative to the dq coordinates of the motor 4). Figure 6BThis is a vector diagram showing that the estimated coordinates during phase estimation of the motor of the washing machine in the first embodiment are in an advanced state (the γδ coordinates (estimated dq coordinates) are slightly advanced relative to the dq coordinates of the motor 4).

[0066] In the vector diagram, the γ-axis induced voltage error ΔVeγ is the γ-axis component of the estimated induced voltage vector Ve (=ω×Ψa) obtained by subtracting the voltage drop of the current flowing through Ra and ωL from the input voltage Va of the motor 4. Since the induced voltage vector Ve is always on the q-axis, when the estimated phase error Δθ (the state in which the γδ coordinates rotate counterclockwise relative to the dq coordinates is set to positive) is 0, the q-axis is consistent with the δ-axis. Fig. 6A The estimated phase error Δθ is negative (Δθ<0). Figure 6B The estimated phase error Δθ is positive (Δθ>0).

[0067] Feedback control is performed by the γ-axis induced voltage error amplifier 29 in the following manner: Fig. 6A In the case of increasing the estimated speed ω, making θ more advanced, Figure 6B When , the estimated speed ω is reduced and θ is delayed, thereby making the γ-axis induced voltage error ΔVeγ and the estimated phase error Δθ zero.

[0068] As described above, phase estimation is based on the premise that the motor is rotating in a state where the induced voltage Ve exists. Therefore, phase estimation is not stable in a low-speed range at startup or stop when the induced voltage is low. Therefore, open-loop control without phase estimation will be described next.

[0069] Figure 7 This is a control block diagram of the motor of the washing machine in the open loop state according to the first embodiment.

[0070] The microcomputer (microcomputer) in the control unit 20, the inverter control timer (timer) built into the microcomputer, the A / D conversion, the memory circuit, the 3-phase 2-phase converter 22, the Iδ error amplifier 23, the Iγ error amplifier 24, the 2-phase 3-phase converter 25 and Figure 4 are common.

[0071] The phase calculation unit 30 integrates the phase per unit time based on the initial phase θinit and the speed command ωs set per unit time, thereby obtaining the phase θ. At this time, since the speed estimation is not performed in the open loop, the speed command ωs is directly used as the speed ω for control. In addition, the δ-axis current command Iδs and the γ-axis current command Iγs set per unit time are input to the Iδ error amplifier 23 and the Iγ error amplifier 24, respectively.

[0072] In the open loop, since control is performed only by the initial phase θinit, the speed command ωs set per unit time, the δ-axis current command Iδs, and the γ-axis current command Iγs, it is usually used as a driving method limited to the low-speed area where phase estimation is unstable when starting and braking. Here, an example of current control using the δ-axis current command Iδs and the γ-axis current command Iγs is described, but it can also be set as voltage control in which the command δ-axis voltage Vδs and the command γ-axis voltage Vγs are set per unit time, and it can also be replaced by voltage control in which only the modulation degree is set per unit time.

[0073] For the above structure, refer to Figure 8A to Figure 12 And Table 1 to illustrate the action.

[0074] Fig. 8A This is a flowchart of the sensorless control process of the motor of the washing machine in the first embodiment. Figure 8B This is a flowchart of another sensorless control process of the motor of the washing machine in the first embodiment.

[0075] like Fig. 8A As shown, the sensorless control process starts from step S100. In step S101, the sensorless open-loop acceleration control process routine is started from the motor stop state. After the phase estimation flag is set in step S102, the process is transferred to the sensorless phase estimation control process routine in step S103. After receiving the information of speed ω and phase θ, speed control including acceleration and deceleration is performed according to the sequence. After the phase estimation flag is cleared in step S104, the process is transferred to the sensorless open-loop deceleration control process routine in step S105. After receiving the information of speed ω and phase θ, deceleration control is performed. After the speed ω becomes 0 and stops in step S106, the sensorless control is ended in step S107.

[0076] Here, if Figure 8B As shown, Fig. 8A The steps S105 and S106 shown can also be replaced with S105a and S106a. The vehicle is stopped by braking such as short-circuit braking or mechanical braking in step S105a. In step S106a, instead of speed ω, the vehicle is considered stopped after a fixed time T1 required for stopping has passed from the time T from the start of braking, and the sensorless control is terminated in step S107.

[0077] use Figures 9 to 11 The start of the sensorless open-loop acceleration control of the motor of the washing machine in the first embodiment will be described.

[0078] Fig. 9 This is a flowchart of the sensorless open-loop acceleration control process of the motor of the washing machine in the first embodiment.

[0079] The sensorless open-loop acceleration control process starts from step S200, and it is confirmed in step S201 whether it is a restart caused by motor locking. If it is not a restart, the normal parameters are input in step S202, and if it is a restart, the locking parameters corresponding to the number of restarts are input in step S203.

[0080] Table 1 shows parameter settings when the motor of the washing machine in the first embodiment is started.

[0081] [Table 1]

[0082]

[0083] The parameters include the phase fixing time T2 of the initial phase fixing control, the fixed phase θfix, the command δ axis current Iδ, the command γ axis current Iγ, and the rotation direction, acceleration α, the command δ axis current Iδ, and the command γ axis current Iγ of the set speed control. These are examples of settings, and the settings can be changed according to the sequence of stirring, dehydration, etc., and the amount of laundry.

[0084] The initial phase fixation control performed in step S204 applies a phase-fixed DC voltage, and the rotor position is converged to a fixed phase θfix (for example, 270° or 90°). By performing the initial phase fixation control again at a phase θfix (for example, 0°) shifted by 90°, it is easy to make the rotor position converge to an arbitrary phase (for example, 0°). Continue in step S205 until a fixed time T2 has passed. In order to speed up the startup, it can be set to T2=0s and immediately transfer to step S206.

[0085] The set speed control performed in step S206 does not detect the speed ω, but maintains acceleration as an open loop equivalent to the set speed ωs. After the set speed ωs exceeds ω1 (for example, 100 rpm) set based on the speed at which the phase can be estimated in step S207, the phase estimation flag is set in step S208, and the sensorless open-loop acceleration control processing is ended in step S209.

[0086] Fig.10 This is a vector diagram of the initial phase fixing control of the motor of the washing machine in the first embodiment. Fig.11 1 is a graph showing the command rotation speed of the sensorless open-loop acceleration control of the motor of the washing machine in the first embodiment.

[0087] like Fig.10 As shown, the phase θfix is ​​set to a fixed coordinate of the initial phase fix control ωs=0 rpm, and the coordinate set by the microcomputer is 0° in the γ-axis direction and 90° in the δ-axis direction.

[0088] pass Fig.11 The following describes the operations of restarting the vehicle normally, restarting the vehicle for the first time after a lock is detected, and restarting the vehicle for the second time after a lock is detected.

[0089] Normally, the phase fixing time T2 is set to 0s, and the initial phase fixing control is not performed. From the initial start, the set speed control is accelerated to ω1 in the CW direction, with an acceleration α1 (for example, 100rpm / s, an acceleration that increases by 100rpm in one second), and a current setting (for example, Iδs=1A, Iγs=0A). Since the initial phase fixing control is not performed as in the locking operation described below, no extra time is generated during startup. In addition, since the acceleration α of the set speed control is large and the acceleration time is short compared to the locking operation, a quick startup control can be performed. In addition, since the current is suppressed compared to the locking operation, an energy-saving operation can be performed.

[0090] For the first restart after detecting the lock, during the period of 0 to T2_1 / 2 (for example, 1s), the initial phase fixation control is controlled by the current setting (for example, Iδs=-1A, Iγs=0A, θfix=270°), and during the period of T2_1 / 2 to T2_1 (for example, 2s), the initial phase fixation control is controlled by the current setting (for example, Iδs=0A, Iγs=1A, θfix=0°) to make the rotor position converge to 0°. After T2 (for example, 2s), the set speed control is made to rotate in the CCW direction opposite to the normal CW direction when accelerating to ω1 with the CCW direction, acceleration α2 (for example, 50rpm / s), and current setting (for example, Iδs=2A, Iγs=0A), so that the lock state caused by the bias of the cloth during the stirring start is easily released. The acceleration is lower than usual (e.g., 100rpm / s→50rpm / s), so that it is not easy to cause a step loss due to rapid acceleration, and the command current is increased (e.g., Iδs=1A→2A, Iγs=0A) to increase the torque, making it easy to release the lock. In addition, since the initial phase fixed control is short, the acceleration α is also large, and the acceleration time is short relative to the second restart action described below, a quick start control can be performed. In addition, since the current is suppressed relative to the second restart action, an energy-saving action can be performed.

[0091] Regarding the second restart after locking is detected, during the period of 0 to T2_2 / 2 (for example, 2s), the initial phase fixed control is controlled with the current setting (for example, Iδs=2A, Iγs=0A, θfix=90°), and during the period of T2_2 / 2 to T2_2 (for example, 4s), the initial phase fixed control is controlled with the current setting (for example, Iδs=0A, Iγs=2A, θfix=0°) so that the rotor position converges to 0°. By changing the fixed phase θfix during the period of 0 to T2 / 2 from 270° in the first restart to 90°, the phase is easy to converge even when the phase is locked for the first time near 90°. In addition, by increasing the command current (Iδs, Iγs), a larger rotation torque is generated, and the phase fixing time is increased (for example, 2s→4s), thereby ensuring the time for phase convergence. After T2 (for example, 4 seconds), the set speed control is accelerated to ω1 in the CW direction, at an acceleration α2 (for example, 25 rpm / s) and at a current setting (for example, Iδs=3A, Iγs=0A).

[0092] Rotating in the CW direction opposite to the CCW direction of the first restart makes it easy to release the locked state caused by the bias of the cloth during the stirring start. The acceleration is lower than the first restart (for example, 50rpm / s→25rpm / s), which is not easy to cause a step loss due to rapid acceleration, and the command current is increased (for example, Iδs=2A→3A, Iγs=0A) to increase the torque, making it easy to release the lock.

[0093] In the above description, the motor applied voltages (Vus, Vvs, Vws) are calculated using the currents (Iδs, Iγs). However, the motor applied voltages (Vus, Vvs, Vws) may be calculated by setting the voltages (Vδs, Vγs).

[0094] Fig.12 This is a flowchart of the sensorless phase estimation control process of the motor of the washing machine in the first embodiment.

[0095] The sensorless phase estimation control process starts from step S300, and it is determined in step S301 whether it is locked. When the speed ω and the induced voltage Ve calculated by phase estimation are extremely low relative to the set speed ωs, it is determined that they are detected. If it is not locked, it proceeds to step S302, and if it is locked, it proceeds to step S305. In step S305, if the locked state is less than the specified time T3 (for example, 5s), it proceeds to step S302, and if it exceeds T3, it proceeds to step S306.

[0096] In step S302, the final speed ω and phase θ of the sensorless open-loop acceleration control are used as initial values ​​to perform speed control, and the process proceeds to step S303.

[0097] The δ-axis current command Iδs is set according to the speed ω so that the motor rotates at the set speed ωs determined by the sequence. Fig.13 In step S303, when the speed ω becomes smaller than ω2 (for example, 100 rpm) set based on the speed at which phase estimation is impossible, the process proceeds to step S308, and when it becomes larger than ω2, the process returns to the lock state confirmation of step S301.

[0098] In step S306, the number of locking times is confirmed. If it is less than the specified number n1 (for example, 16 times), the process proceeds to step S308 and restarts through sensorless open-loop acceleration control. If it is greater than the specified number n1, an abnormality is notified in step S307 as the motor locking state has not been eliminated.

[0099] The phase estimation flag is cleared in step S308 , and the sensorless phase estimation control process is terminated in step S309 .

[0100] Fig.13 This is a flowchart of the speed control process of the motor of the washing machine in the first embodiment.

[0101] The speed control process starts from step S400, and in step S401, the command speed ωs corresponding to the acceleration or deceleration sent from the sequence unit of the washing machine is calculated. In step S402, the speed ω is calculated according to the speed phase estimation unit 21, and in step S403, it is confirmed whether the speed ω is greater than the command speed ωs. In step S403, if the speed ω is greater than the command speed ωs ("yes"), in step S404, the command Iδs is reduced to reduce the acceleration torque. In step S403, if the speed ω is less than the command speed ωs ("no"), since the torque is insufficient, the command Iδs is increased in step S405 to increase the torque.

[0102] The speed loop of steps S401 to S405 is repeated at a fixed period (for example, every 1 ms).

[0103] In step S406, 3-phase 2-phase conversion is performed based on the phase currents (Iu, Iv, Iw) detected by the current detection unit 18 and the estimated phase θ calculated by the speed phase estimation unit 21, and the δ-axis current Iδ is calculated. In step S407, it is confirmed whether Iδ is larger than the command Iδs. If Iδ is larger than the command Iδs ("Yes"), the command Vδs is reduced in step S408. If Iδ is smaller than the command Iδs ("No"), the command Vδs is increased in step S409.

[0104] In step S410, Iγ is also converted into 2-phase 3-phase in the same manner as Iδ, based on the phase currents (Iu, Iv, Iw) detected by the current detection unit 18 and the estimated phase θ calculated by the speed phase estimation unit 21, and the γ-axis current Iγ is calculated. In step S411, it is confirmed whether Iγ is larger than the command Iγs. If Iγ is larger than the command Iγs ("Yes"), the command Vγs is reduced in step S412. If Iγ is smaller than the command Iγs ("No"), the command Vγs is increased in step S413.

[0105] Next, in step S414, 2-phase to 3-phase conversion is performed based on the command Vδs and the command Vγs and the estimated phase θ calculated by the speed phase estimation unit 21, and applied voltages Vus, Vvs, and Vws are calculated. In step S415, the voltages are applied to the motor.

[0106] The current sub-loop of steps S406 to S415 is repeated at a fixed period (eg, every 0.1 ms) that is faster than the speed loop.

[0107] Finally, the speed control process ends in step S416.

[0108] The speed loop of steps S401 to S405 compares ω with the command ωs and outputs a command Iδs. However, since the variable factor is large, the control is unstable, so PI control with an integral factor such as averaging is performed.

[0109] Similarly, in the current sub-loop of steps S406 to S415, Iδ and Iγ are compared with the instructions Iδs and Iγs, respectively, and the instructions Vδs and Vγs are output, respectively. However, since the variable factors are large and the control is unstable, PI control with integral elements such as averaging is performed.

[0110] (Function, etc.)

[0111] As described above, the washing machine in the present embodiment includes: a clothes stirring impeller 1 as a rotating object, which contacts the laundry; a motor 4 as an electric motor, which has a permanent magnet 4d and windings 4a, 4b, 4c; an inverter circuit 17 as a power supply circuit, which supplies current to the motor 4; a motor pulley 31, a belt 5, an impeller pulley 32, and a speed reduction mechanism and clutch 6 as a transmission mechanism, which transmit the torque of the motor 4 to the impeller 1; and a control unit 20, which performs a washing operation. In addition, the control unit 20 performs a sensorless open-loop acceleration control process as a first control process, which performs energization regardless of the position of the permanent magnet 4d relative to the windings 4a, 4b, 4c, and the second control process performs energization according to the position of the permanent magnet 4d relative to the windings 4a, 4b, 4c. Furthermore, the control unit 20 can execute a sensorless phase estimation control process that detects that the permanent magnet 4d is locked when it does not rotate at a predetermined speed after the sensorless open-loop acceleration control process is transferred to the sensorless phase estimation control process. Then, when the control unit 20 detects that the motor 4 is locked in the sensorless phase estimation control process, the control unit 20 performs phase fixing control of different phases a plurality of times when driving is started based on the sensorless open-loop acceleration control process.

[0112] With this configuration, the rotor position can be easily converged to an arbitrary phase, the torque at the time of initial driving can be easily transmitted to the motor, and the locked state can be easily eliminated.

[0113] As in the present embodiment, when the control unit 20 detects that the motor 4 is locked during the sensorless phase estimation control process, the control unit 20 may change the phase of the phase fixing control based on the sensorless open-loop acceleration control process.

[0114] With this structure, regardless of the rotor position at which the motor is locked, the torque at the time of initial driving can be easily transmitted to the motor, thereby easily eliminating the locked state.

[0115] As in the present embodiment, when the control unit detects that the motor 4 is locked in the sensorless phase estimation control process during the stirring or rinsing sequence, the control unit may reverse the driving rotation direction by the sensorless open-loop acceleration control process.

[0116] With this structure, even if the cloth gathers in either the left or right direction of the impeller rotation and cannot be started, the gathered cloth can be untied by temporarily starting in the direction opposite to the locked rotation direction to eliminate the locked state of the original locked rotation direction.

[0117] In addition, as in the present embodiment, it is also possible to have: a clothes stirring impeller 1 as a rotating object, which contacts the laundry; a motor 4 as an electric motor, which has a permanent magnet 4d and windings 4a, 4b, 4c; an inverter circuit 17 as a power supply circuit, which supplies current to the motor 4; a motor pulley 31, a belt 5, an impeller pulley 32, and a speed reduction mechanism and clutch 6 as a transmission mechanism, which transmit the torque of the motor 4 to the impeller 1; and a control unit 20, which performs a washing operation. In addition, the control unit 20 performs a sensorless open-loop acceleration control process as a first control process, and a sensorless phase estimation control process as a second control process, the first control process performs energization regardless of the position of the permanent magnet 4d relative to the windings 4a, 4b, 4c, and the second control process performs energization according to the position of the permanent magnet 4d relative to the windings 4a, 4b, 4c. Furthermore, the control unit 20 can also perform a sensorless phase estimation control process that detects that the permanent magnet 4d is locked when it does not rotate at a predetermined speed after the sensorless open-loop acceleration control process is transferred to the sensorless phase estimation control process. Then, when the control unit 20 detects that the motor 4 is locked in the sensorless phase estimation control process, the drive speed acceleration based on the sensorless open-loop acceleration control process is reduced.

[0118] With this configuration, it is possible to suppress the step-out caused by acceleration during locking, transmit torque to the motor, and easily cancel the locked state.

[0119] As in the present embodiment, when the control unit 20 detects that the motor 4 is locked during the sensorless phase estimation control process, the control unit 20 may increase the current or voltage controlled by the sensorless open-loop acceleration control process.

[0120] With this structure, a strong torque can be transmitted to the motor, thereby making it possible to easily eliminate the locked state.

[0121] As in the present embodiment, when the control unit detects that the motor 4 is locked in the sensorless phase estimation control process during the stirring or rinsing sequence, the control unit may reverse the driving rotation direction by the sensorless open-loop acceleration control process.

[0122] With this structure, even if the cloth gathers in either the left or right direction of the impeller rotation and cannot be started, the gathered cloth can be untied by temporarily starting in the direction opposite to the locked rotation direction to eliminate the locked state of the original locked rotation direction.

[0123] (Other Embodiments)

[0124] As described above, the first embodiment has been described as an example of the present disclosure, but the technology in the present disclosure is not limited thereto.

[0125] Therefore, other embodiments are exemplified below.

[0126] The first embodiment is described by taking the vertical washing machine of the pulsator type that the motor pulley 31 is connected with the impeller pulley 32 by the belt 5 and is combined with the pulsator 1 or the washing and dehydrating groove 2 by the speed reduction mechanism and clutch 6 as an example. But, even in the washing machine of the direct drive mode that the washing and dehydrating groove is coaxial with the motor, when the startup fails and thus becomes the locked state, the locked state can be easily eliminated.

[0127] Furthermore, the first embodiment has been described by taking a pulsator-type vertical washing machine as an example. However, even in a drum-type washing machine, if a start-up fails and the washing machine is locked, the locked state can be easily released.

[0128] Industrial Applicability

[0129] The present invention can easily eliminate the locked state by changing the starting method when the start-up fails and the locked state occurs. Specifically, the present invention can be applied to a pulsator vertical washing machine and a drum washing machine.

[0130] Description of Reference Numerals

[0131] 1: Pulsator (rotating object); 2: Washing and dehydrating tank; 3: Water receiving tank; 4: Motor (electric motor); 4a: Winding; 4b: Winding; 4c: Winding; 4d: Permanent magnet (rotor); 5: Belt (transmission mechanism); 6: Speed ​​reduction mechanism and clutch (transmission mechanism); 7: Gear drive motor; 8: Brake belt; 9: Washing machine frame; 10: Panel; 11: Cover; 12: Display; 13: Control device; 14: Water supply valve; 15: Drain valve; 16: Rectifier circuit; 17: Inverter circuit ( power supply circuit); 18: current detection unit; 19: PWM control unit; 20: control unit; 21: speed phase estimation unit; 22: 3-phase 2-phase converter; 23: Iδ error amplifier; 24: Iγ error amplifier; 25: 2-phase 3-phase converter; 26: speed error amplifier; 27: weak magnetic field setting unit; 28: γ-axis induced voltage calculator; 29: γ-axis induced voltage error amplifier; 30: phase calculation unit; 31: motor pulley (transmission mechanism); 32: impeller pulley (transmission mechanism).

Claims

1. A washing machine comprising: a rotating object which comes into contact with the laundry; an electric motor having permanent magnets and windings; a power circuit that supplies current to the motor; a transmission mechanism that transmits the torque of the motor to the rotating object; and A control unit that performs a washing operation, in, The control unit is capable of executing a first control process, a second control process, and a lock detection process, wherein the first control process performs energization regardless of the position of the permanent magnet relative to the winding, the second control process performs energization corresponding to the position of the permanent magnet relative to the winding, and the lock detection process detects that the permanent magnet is locked when it does not rotate at a specified speed after the first control process is transferred to the second control process. When the control unit detects lock in the lock detection process, the control unit restarts the motor based on the first control process, wherein, when restarting the motor, the control unit performs initial phase fixing control for controlling the phase to a fixed predetermined current and performs set speed control for accelerating the permanent magnet in an open loop after the initial phase fixing control, Here, the driving speed acceleration based on the set speed control when the electric motor is restarted is made lower than the driving speed acceleration based on the set speed control before the electric motor is restarted.

2. The washing machine according to claim 1, wherein: When the control unit detects lock in the lock detection process, the current or voltage controlled in the set speed control by the first control process when restarting the motor is greater than the current or voltage controlled in the set speed control by the first control process before restarting the motor.

3. The washing machine according to claim 1 or 2, wherein: When the lock is detected in the lock detection process during the agitation or rinsing sequence, the control unit reverses the driving rotation direction of the motor based on the first control process when restarting the motor relative to the driving rotation direction based on the first control process before restarting the motor.

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