JP6023974B2 - Washing machine - Google Patents

Description

  The present invention relates to a motor drive device for a washing machine.

  Conventionally, this type of washing machine is driven by vector control to allow constant torque control when detecting the load imbalance of the washing and dewatering tub, and by detecting fluctuations in the rotation speed during dewatering rotation. By detecting the imbalance of the clothes and controlling the rotation speed according to the imbalance of the clothes, the imbalance detection accuracy is improved and the washing and dewatering tub is rotated at a high speed to improve the dehydration rate. (For example, Reference 1).

Japanese Patent No. 3915557

  However, in such a configuration, even when a high load is applied to the motor, since the rotational speed control is performed so as to maintain the set rotational speed, the motor input power increases, and the motor, motor drive circuit, power supply circuit Therefore, there is a problem that the current flowing through the power supply circuit is increased, the fuse for protecting the power supply circuit is blown, and the motor, the motor drive circuit, and the power supply circuit components are broken.

  The present invention solves the above-described conventional problems, and is a washing machine that protects a motor, a motor drive circuit, and a power circuit by controlling the motor input power within an allowable range and suppresses a decrease in dewatering performance. It is intended to provide.

  In order to solve the conventional problems, a washing machine of the present invention includes a rotating drum that accommodates laundry and is driven to rotate, an inverter circuit that converts DC power rectified by a rectifier circuit into AC power, and the rotation A motor for driving the drum by the inverter circuit; position detecting means for detecting a rotor position of the motor; a rotational speed control means for controlling the rotational speed so that the motor has a set rotational speed; and an input to the motor Motor electric power detection means for detecting the electric power to be performed, and control means for controlling at least one of the washing, rinsing and dehydration processes, wherein the control means has a first motor input power during the dehydration operation. When the first predetermined power is exceeded for a predetermined time or longer, the set rotational speed is changed, and the motor input power is controlled to be a constant power.

  As a result, the dehydration operation can be performed while suppressing the motor input power, and the dehydration operation can be continued.

  And an input voltage control means for controlling the input voltage of the motor, and a current detection means for detecting the input current of the motor, wherein the motor power detection means has a rotational coordinate synchronized with the rotor of the motor. The motor input power is calculated from the components of the motor input voltage and the motor input current.

  As a result, the motor input power can be easily calculated without being affected by the position detection detection error.

  The motor power detection means calculates the motor input power from the components of the motor input voltage and the motor input current at a stationary coordinate.

  As a result, even when the motor control is performed other than the vector control, the motor input power can be calculated.

  The power supply current detection means for detecting a power supply input current flowing in the power supply circuit; and a power supply voltage detection means for detecting a power supply input voltage applied to the power supply circuit, wherein the motor power detection means includes the power supply input voltage and the power supply voltage detection means. The power input power is calculated from the power input current component, and the motor input power is calculated at a predetermined ratio from the power input power.

  As a result, the motor input power can be easily calculated even in a circuit that already has a power supply power detection circuit.

  Further, the control means extends the dehydration set time in accordance with a decrease in the set rotational speed.

  As a result, the set time for dehydration can be increased, and the decrease in dewatering performance due to the decrease in the rotational speed can be suppressed.

Further, the control means stops the dehydration operation when the motor input power exceeds a second predetermined power greater than the first predetermined power for a second predetermined time or more, and performs the same dehydration operation again. Is.

  As a result, when the motor input power continues to increase, the motor can be safely stopped.

  In addition, a water level detection means for detecting the water level of the water receiving tank and a drain means for draining the water of the water receiving tank, the control means when the dehydration operation is stopped due to an increase in motor input power, Is detected, the drainage is continued until the drainage is completed, and the dehydration operation is started after the drainage.

  As a result, when water cannot be discharged well in a short time and the load increases, the load due to water can be reduced by continuing to drain.

  In addition, a notification unit that performs a notification operation is provided, and the control unit stops the dehydration operation due to an increase in motor input power, and notifies the abnormality by the notification unit when the dehydration operation to be performed again reaches a predetermined number of times. It is a thing.

  As a result, when the motor input power is increased due to a failure of the motor, the motor drive circuit, or the power supply circuit, the user can be encouraged to respond by this abnormality notification.

  In the washing machine of the present invention, when a high load is applied to the motor, the motor input power is controlled to be within an allowable range to protect the motor, the motor drive circuit, and the power supply circuit, and to prevent a decrease in dewatering performance. Can do.

Sectional drawing of the principal part of the washing machine in this Embodiment Block diagram of the washing machine Time chart of motor control of the washing machine Flow chart of dehydration process of the washing machine Flow chart of motor control setting subroutine of the washing machine Flow chart of constant power control subroutine of the washing machine The figure which shows the setting rotation speed and dewatering setting time of the same washing machine Flow chart of high power detection control subroutine of the washing machine Time chart of constant power control of the washing machine Time chart of high power detection control of the washing machine Flow chart of motor drive subroutine of the washing machine Flow chart of carrier signal interrupt subroutine of the washing machine Flowchart of position signal interrupt subroutine of the washing machine Flow chart of rotation speed control subroutine of the washing machine

  According to a first aspect of the present invention, there is provided a washing machine according to the present invention, comprising: a rotary drum that accommodates laundry and is driven to rotate; an inverter circuit that converts DC power rectified by a rectifier circuit into AC power; A motor driven by an inverter circuit; position detecting means for detecting a rotor position of the motor; rotation speed control means for controlling the rotation speed so that the motor has a set rotation speed; and electric power input to the motor And a control means for controlling at least one of the washing, rinsing, and dehydration strokes, and the control means has a motor input power for a first predetermined time during the dehydration operation. As described above, when the first predetermined power is exceeded, by changing the set rotation speed and controlling the motor input power to be constant, it is possible to perform the dehydrating operation while suppressing the motor input power. In the motor due to high power, the motor driving circuit to prevent breakdown of the power supply circuit, not stop immediately, by continuing the dehydration operation, it is possible to suppress deterioration in dewatering performance in normal dewatering time.

  The second invention, in particular, in the configuration of the first invention, comprises input voltage control means for controlling the input voltage of the motor, and current detection means for detecting the input current of the motor, and the motor power detection means. The motor input power is calculated from the motor input voltage and motor input current components at the rotation coordinates synchronized with the motor rotor, so that it is not affected by the detection error of the position detection, and the motor input is simple. Electric power can be calculated.

  According to a third aspect of the invention, in particular, in the configuration of the second aspect of the invention, the motor power detection means calculates the motor input power from the motor input voltage and motor input current components at a stationary coordinate, thereby vectorizing the motor control. The motor input power can be calculated even when performing other than control.

  According to a fourth aspect of the invention, in particular, in the configuration of any one of the first to third aspects of the invention, a power source current detecting means for detecting a power source input current flowing in the power source circuit, and a power source for detecting the power source input voltage applied to the power source circuit Voltage detection means, and the motor power detection means calculates power input power from the power input voltage and power input current components, and calculates motor input power at a predetermined ratio from the power input power. In the case of a circuit that already has a power supply power detection circuit, the motor input power can be easily calculated.

  According to a fifth invention, in particular, in the configuration of any one of the first to fourth inventions, the control means increases the motor input power by extending the dehydration set time in response to a decrease in the set rotational speed. Thus, even when the dehydrating operation is controlled at a low set rotational speed, it is possible to increase the set time for dehydration and suppress a decrease in dewatering performance due to a decrease in the rotational speed.

In a sixth aspect of the invention, in particular, in the configuration according to any one of the first to fifth aspects, the control means supplies a second predetermined power that is greater than the first predetermined power for a motor input power that is equal to or longer than a second predetermined time. If the motor input power continues to increase by stopping the dehydration operation when it exceeds the limit and performing the same dehydration operation again, the motor, motor drive circuit, and power supply circuit can be safely The motor can be stopped.

  According to a seventh aspect of the present invention, in the configuration of the sixth aspect of the invention, the seventh aspect further comprises a water level detecting means for detecting the water level of the water receiving tank and a drain means for draining the water in the water receiving tank, and the control means has motor input power. When the dewatering operation is stopped due to an increase in water, the water level is detected, and the drainage is continued until the drainage is completed. Is not drained, and the drainage hose and the lower end of the drum accumulate from the drainage groove to increase the load. By continuing to drain, the load due to water can be reduced. Further, since the detected water level is fluctuated by the wind pressure generated by the rotating drum during dehydration, the water level detecting means can detect that the water has been drained accurately by detecting the water level after stopping the rotation.

  In an eighth aspect of the present invention, in particular, in the configurations of the sixth and seventh aspects of the present invention, the control unit includes a notification unit that performs a notification operation. When the number of times is reached, an abnormal notification is made by the notification means, thereby causing an abnormal load state that is a cause of generation of large power (for example, sandwiching of laundry between a rotating drum and a water receiving tub, excessively heavy laundry The user can be urged to reduce the excessive load (such as residual water in the rotating drum), thereby reducing the load, reducing the motor input power, and performing a normal dehydrating operation. Further, when the motor input power is increased due to failure of the motor, the motor drive circuit, and the power supply circuit, the user can be urged to repair the parts by this abnormality notification.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a cross-sectional view of a main part of a washing machine. A rotary drum 1 is formed in a bottomed cylindrical shape and has a large number of water passage holes in a side wall and is rotatably disposed in a water receiving tub 2. ing. One end of a rotation shaft (rotation center shaft) provided in the tilt direction is fixed to the rotation center of the rotary drum 1, and a drum pulley 3 is fixed to the other end of the rotation shaft. Note that the direction of the rotation axis of the rotation axis is inclined downward from the horizontal direction from the front side of the washing machine toward the back side as the bottom.

  The motor 4 attached to the back surface of the water receiving tank 2 is connected to the drum pulley 3 by a belt 5, and is configured and rotated so that the rotating drum 1 can be rotated forward or reverse by the motor 4. Several projecting plates are provided on the inner wall surface of the rotating drum 1, and the laundry is caught by the projecting plates at the time of rotation and dropped from an appropriate height. Further, the water receiving tub 2 is suspended by a top plate of the washing machine main body so as to be swingable by a spring body, and the opening on the front side of the rotary drum 1 is covered with a lid (lid) so as to be freely opened and closed.

  As shown in FIG. 2, the AC power supply applies AC power to the rectifier circuit 6, the rectifier circuit 6 constitutes a voltage doubler rectifier circuit, and the full-wave rectifier diode 6a causes a capacitor 6b when the AC power supply is positive. When the AC power supply is a negative voltage, the capacitor 6c is charged, a double voltage DC voltage is generated across the capacitors 6b and 6c connected in series, and the double voltage DC voltage is applied to the inverter circuit 7.

  The inverter circuit 7 is constituted by a three-phase full-bridge inverter circuit composed of six power switching semiconductors and an antiparallel diode, and normally includes an insulated gate bipolar transistor (IGBT), an antiparallel diode, its driving circuit, and a protection circuit. It consists of an intelligent power module (hereinafter referred to as IPM). The motor 4 is connected to the output terminal of the inverter circuit 7 and driven.

  The motor 4 is constituted by a direct current brushless motor, and the position detecting means 8 detects the relative position (rotor position) between the permanent magnet and the stator constituting the rotor. The position detection means 8 is usually composed of three hall sensors 8a, 8b, 8c and detects a position signal for every 60 electrical angles.

  The current detection means 9 connects shunt resistors 9a, 9b, 9c between the negative voltage terminal of the inverter circuit 7 and the negative voltage terminal of the rectifier circuit 6, and inputs the input current of the inverter circuit 7 calculated from the voltage across the shunt resistor. Originally, the phase currents Iu, Iv, Iw of the motor 4 are detected. Usually, a shunt resistor is used, but it can also be detected by an AC current transformer or a DC current transformer.

  The control means 10 controls the number of revolutions of the motor 4 by controlling the inverter circuit 7 based on the information on the motor phase and the motor phase current detected by the position detection means 8 and the current detection means 9. is there. A microcomputer and an inverter control timer (PWM timer) built in the microcomputer, a high-speed A / D conversion circuit, a memory circuit (ROM, RAM), and the like are used to detect the electrical angle from the output signal of the position detection means 8 An angle detection unit 11; a three-phase / 2-phase dq conversion unit 12 that decomposes an output signal from the current detection unit 9 and a signal from the electrical angle detection unit 11 into a current component Id corresponding to magnetic flux and a current component Iq corresponding to torque; , Storage means 13 for storing sine wave data (sin, cos data) necessary for converting from a stationary coordinate system to a rotating coordinate system, or reverse conversion, a voltage component Vd corresponding to magnetic flux, and a voltage component corresponding to torque Two-phase / 3-phase dq reverse conversion means 14 for converting Vq into three-phase motor drive control voltages Vu, Vv, Vw, and three-phase motor drive control voltages Vu, Vv Depending on Vw has a an input voltage control means 15 for controlling the PWM output for controlling the IGBT switching of the inverter circuit 7.

  The control means 10 detects the motor rotation speed and the drum rotation speed from the setting change means 16 for controlling the start, stop, rotation speed, braking and the like of the motor 4 according to the stroke, and the output signal of the position detection means 8. The rotational speed detection means 17, the rotational speed control means 18 for controlling the rotational speed of the rotary drum 1 in accordance with the output signal of the rotational speed detection means 17, the d axis (direct) from the setting change means 16 and the rotational speed control means 18. -Axis) The current setting signal Ids, the q-axis (quadrature-axis) current setting signal Iqs, and Id and Iq calculated by the three-phase / 2-phase dq converting means 12 are compared, and the magnetic flux corresponding to the motor current is controlled. Current control means 19 for calculating the voltage component Vd and the voltage component Vq corresponding to the torque is provided.

  Torque control can be performed by performing feedback control so that the q-axis current Iq corresponding to the torque becomes the set value Iqs. However, when the drum rotation speed increases, the motor induced voltage increases and the torque current Iq does not increase. Therefore, the q-axis current can also be increased by so-called weakening magnetic flux control that increases the d-axis current according to the drum rotation speed. And torque can be increased.

  Furthermore, the control means 10 has a display means 21 and a sounding means 22, a notification means 23 for displaying an operating state and a notification at the time of abnormality, a water supply valve 24 connected between the AC voltage terminals, a drain valve (drainage means) ) 25 is detected by a water supply valve control means 27, a drain valve control means 28, which controls 25 by a switching means drive circuit 26, and a water pressure at a connection portion under the water receiving tank 2 is converted into an electrical frequency. The power level detection means 29 calculates the power level power averaged every cycle of the AC power source from the power level power detected by the water level detecting means 29 and the power source power detection circuit 30 connected between the AC power source and the rectifier circuit 6. Means 31 and motor power detection means 32 for calculating motor power are provided.

  The water supply valve 24 supplies the tap water to the water receiving tank 2 and is constituted by an electromagnetic valve. The drain valve (drainage means) 25 is a drain means for draining the water in the water receiving tank 2. The switching means driving circuit 26 is constituted by a solid state relay such as a bidirectional thyristor or a mechanical relay.

  The power supply power detection circuit 30 includes power supply current detection means 30a for detecting current and power supply voltage detection means 30b for detecting voltage.

  The motor power detection means 32 calculates motor power by one of the following three methods.

  The first is that the motor input voltages Vd and Vq at the rotation coordinates (dq plane) synchronized with the rotor of the motor 4 from the two-phase / three-phase dq reverse conversion means 14 and the three-phase / 2-phase dq conversion means. 12, Vd · Id + Vq · Iq is calculated using motor input currents Id and Iq in the rotational coordinates (dq plane). This value is a scalar product of the voltage vector and the current vector, and is the product of the absolute value of the voltage vector, the absolute value of the current vector, and the power factor cos θ (phase difference θ between the voltage and current), so that the motor input power Pi is Pi = | V || I | cos θ = Vd · Id + Vq · Iq. Here, even if the position detection means 8 has a detection error Δθ, it does not affect the power factor cos θ, so that the motor input power Pi is not affected by the detection error Δθ. In general, since Vd, Vq, Id, and Iq always exist in a motor control system based on vector control, it can be realized easily. In actual operation, there are noise components in which Vd, Vq, Id, and Iq fluctuate due to load fluctuations. Therefore, LPF (low-pass filter) is used for Vd, Vq, Id, and Iq before calculating Pi = Vd · Id + Vq · Iq. ) Or passing LPF through Pi after calculation, the influence of noise components can be suppressed.

  Second, the motor input voltages Vu, Vv, Vw from the 2-phase / 3-phase dq inverse conversion means 14 to the stationary coordinates, and the motor input currents Iu, Iv from the 3-phase / 2-phase dq conversion means 12 to the stationary coordinates. , Iw, and motor input power Pi is calculated as Pi = Vu · Iu + Vv · Iv + Vw · Iw. Thereby, the motor input power can be calculated even in cases other than the motor control system based on vector control.

  Third, a ratio Rm (for example, 0.8) of electric power to be supplied to the motor in the circuit is set, and the motor input power Pi is calculated from the power supply power Pa calculated by the power supply power detection circuit 30 by Pi = Pa × Rm. Calculate as Thereby, in the case of a circuit that already has a power supply power detection circuit, the motor input power can be easily calculated.

  FIG. 3 shows the waveform relationship of each part, and the edge signals of the output signals H1, H2, and H3 of the hall sensors 8a, 8b, and 8c change every 60 degrees, and the angle obtained by dividing 360 degrees from each part state signal is determined. it can. A high edge where the signal H1 changes from low to high is indicated as a reference electrical angle of 0 degree, and the U-phase winding induced voltage Ec of the motor 4 has a waveform delayed by 30 degrees from the reference signal H1. Maximum efficiency is obtained when the phases of the U-phase motor current Iu and the motor-induced voltage Ec are the same. The motor induced voltage Ec is the same axis as the q axis, and the d axis is delayed by 90 degrees. Since the q-axis current is in phase with the motor induced voltage phase, it is called torque current.

  In FIG. 3, the U-phase motor current Iu slightly advances from the U-phase winding induced voltage Ec, and the motor applied voltage Vu shows a waveform advanced 30 degrees from the U-phase winding induced voltage Ec. Vc is a sawtooth waveform carrier signal generated in the input voltage control means 15, Vu is a sine wave U phase control voltage, and a PWM signal u which compares the carrier signal Vc and the U phase control voltage Vu is input voltage control means. 15 and is added as a control signal for the U-phase upper arm transistor of the inverter circuit 7. ck is a synchronizing signal of the carrier signal Vc, and is an interrupt signal when the carrier counter counts up and overflows.

  Coordinate conversion from the stationary coordinate system to the rotating coordinate system, that is, dq conversion, is performed with the electrical angle at which the rotor magnet axis of the motor 4 and the magnetic flux axis of the stator coincided as the d axis, and a reference electrical angle of 0 degrees. 11 detects electrical angles such as 30 degrees, 90 degrees, and 150 degrees from the output signals H1, H2, and H3 of the hall sensors 8a, 8b, and 8c, and calculates the electrical angle θ by estimation except every 60 degrees.

  Generally, a current component corresponding to the magnetic flux is called a d-axis current Id, and the torque is zero because the permanent magnet magnetic flux and the field magnetic flux are coaxially attracted to the field magnet. Also, the axis that has the same phase as the induced voltage phase and the maximum torque at an electrical angle of 90 degrees from the d axis is called the q axis, and is called the q axis current Iq because it is a current component corresponding to the torque. Further, increasing the d-axis current in the negative direction is equivalent to weakening the field magnetic flux on the d-axis, and is called field weakening control or weakening magnetic flux control (or magnetic flux weakening control). Also, since it is divided into d-axis current and q-axis current and controlled independently, it is called vector control.

  The three-phase / two-phase dq conversion means 12 converts the motor currents Iu, Iv, and Iw into the d-axis current Id and the q-axis current Iq according to (Equation 1). Then, Id and Iq are calculated from the instantaneous motor current value detected corresponding to the electrical angle θ.

  Since the storage unit 13 stores data of sin θ and cos θ, it can be decomposed into the d-axis current Id and the q-axis current Iq by calling the data corresponding to the electrical angle data and performing the product-sum operation. The detection of the electrical angle θ and the detection of the instantaneous motor current value are performed in synchronization with the carrier signal, and will be described in detail according to the flowchart described later.

  The rotation speed detection means 17 detects the motor rotation speed from any one of the output signals H1, H2, and H3 of the hall sensors 8a, 8b, and 8c, and determines the drum from the number of poles of the motor 4 and the ratio of the drum pulley 3 and the motor pulley. The drum rotation number signal is applied to the setting change means 16 and the rotation speed control means 18 after being converted into the rotation speed. The setting changing means 16 performs start-up control of the motor 4, setting of the drum rotation speed, and calculation of the d-axis current Ids according to the drum rotation speed and the q-axis current setting value Iqs. The setting signal Ns is added, and the d-axis setting signal Ids is added to the current control means 19.

  The rotational speed control means 18 is a rotational speed comparison means 18a for comparing the detected rotational speed n of the drum (hereinafter referred to as detected rotational speed) with the set rotational speed Ns of the drum (hereinafter referred to as set rotational speed), and the detected rotational speed n is set. It comprises an error signal Δn with respect to the rotational speed Ns and torque current setting means 18b for controlling the q-axis current set value Iqs in accordance with the change rate (acceleration) of the rotational speed.

  The current control means 19 compares the output signals Iq and Id of the three-phase / two-phase dq conversion means 12 with the setting signals Iqs and Ids and outputs control voltage signals Vq and Vd, respectively. The q-axis current comparison means 19a , Q-axis voltage setting means 19b, d-axis current comparison means 19c, and d-axis voltage setting means 19d, and generate voltage signals Vq and Vd for controlling the q-axis current and the d-axis current, respectively.

  The d-axis current set value Ids is a signal applied from the setting change means 16 to the current control means 19, and in the case of an embedded magnet motor, the d-axis current set value Ids is increased in accordance with the rotational speed to perform field weakening control. Do. In the case of a surface magnet motor, Ids is normally set to zero, and Ids is increased in the case of high rotational speed driving.

  The two-phase / three-phase dq reverse conversion means 14 calculates the three-phase motor drive control voltages Vu, Vv, and Vw from the voltage signals Vq and Vd according to (Equation 2), and converts them from the rotating coordinate system to the stationary coordinate system. In synchronization with the carrier signal, a sinusoidal signal corresponding to the electrical angle θ detected by the electrical angle detection means 11 is applied to the input voltage control means 15. The method of product-sum calculation of sin θ and cos θ stored in the storage means 13 is almost the same as the calculation of the three-phase / 2-phase dq conversion means 12.

  The operation of the above configuration will be described with reference to FIG. FIG. 4 is a flowchart of the dehydration process. The dehydration process is started from step 100, various initial settings of the dehydration process are performed in step 101, and the set rotational speed Ns is increased with time in step 102. In step 103, the motor drive subroutine shown in FIG. 11 is executed. In step 104, it is determined whether or not the set rotational speed Ns has reached the final set rotational speed Nmax (for example, 900 r / min), and if it has reached Nmax, the process proceeds to step 105 to execute a motor control setting subroutine. If Nmax or less, the process returns to step 102. In step 106, the set time T1 for dewatering is called. In step 107, it is determined whether the set time T1 has elapsed. The motor drive in step 105 is continued until the set time elapses. End the process.

  A flowchart of the motor control setting subroutine shown in FIG. 5 will be described. From step 200, the motor control setting subroutine starts. In step 201, it is determined whether or not the motor input power Pi is greater than or equal to a first predetermined power Pmax1 (for example, 1000 W). If it is greater than or equal to Pmax1, it is determined in step 202 whether or not the detection time Tp1 (for example, 5 seconds) has elapsed. Then, the process continues to return to step 201 until the time elapses, and when Tp1 elapses, Tp1 elapse is held until it becomes less than Pmax1, and the process proceeds to step 203. If it is less than Pmax1, the process proceeds to step 207.

  In step 203, a constant power control subroutine is executed. In step 204, it is determined whether or not the motor input power Pi is greater than or equal to a second predetermined power Pmax2 (eg, 1200 W) that is greater than Pmax1. Then, it is determined whether or not the detection time Tp2 (for example, 1 second) has elapsed, and the process continues to return to step 203 until it elapses. When Tp2 elapses, Tp2 elapses is held until it becomes less than Pmax2, and the process proceeds to step 206. If it is less than Pmax2, the process proceeds to step 207.

  In step 206, a high power detection control subroutine is executed. Subsequently, in step 207, the motor drive subroutine is executed in the same manner as in step 103, and the process returns in step 208.

  A flowchart of the constant power control subroutine shown in FIG. 6 will be described. From step 300, the constant power control subroutine starts. In step 301, the set rotational speed Ns is called. In step 302, it is determined whether or not the motor input power Pi is equal to or greater than the motor input power set value Ps (for example, 1100 W) that is greater than or equal to Pmax1 and less than Pmax2. If the rotational speed Ns is lowered and the set rotational speed Ns is smaller than the minimum Nmin (for example, 500 r / min) that can maintain the dewatering performance in Step 304, Ns = Nmin is set in Step 305, and the set rotational speed Ns falls below Nmin. If not, go to step 310. If it is less than Ps, the set rotational speed Ns is increased in step 307, and if the set rotational speed Ns is larger than the initial final dewatering rotational speed Nmax (for example, 900 r / min) in step 308, the rotational speed is set as Ns = Nmax in step 309. Proceed to step 310 so that the number Ns does not rise above Nmax. If the motor input power Pi and the motor input power set value Ps are compared and determined for each carrier, the fluctuation element is large and the control is not stable. Therefore, it is necessary to add an integral element such as averaging.

  In general, motor output power Po = drum shaft torque T × drum rotation speed n and motor output power Po = motor input power Pi × motor efficiency e are established. When the rotational speed n is decreased, the motor input power Pi decreases, and when the drum rotational speed is increased, the motor input power Pi increases. Therefore, by changing the set rotational speed Ns, the drum rotational speed n changes, and the motor input power Pi is reduced. It can be controlled constantly. However, if the number of revolutions is suddenly reduced, the DC voltage rises due to the effect of regenerative power from the motor, leading to failure of the power supply circuit and inverter circuit. Therefore, it is necessary to gradually reduce the speed during deceleration. Because of the control restrictions during deceleration and the upper limit Nmax and the lower limit Nmin in the set rotational speed, the constant power cannot be maintained even during constant power control and becomes less than Pmax1 for normal rotational speed control. Or return to Pmax2 or more and shift to large current detection control. Usually, the water in the laundry is drained by dehydration, and the drum shaft torque T is reduced. Therefore, the motor input power Pi is decreased and the control returns to the rotational speed control.

  As a result, when the motor input power Pi increases, it is possible to shift to constant power control and perform the dehydration operation while suppressing the motor input power Pi, and the motor, the motor drive circuit, and the power supply circuit are destroyed by the high power. Can be prevented. Further, by continuing the dehydration operation without stopping immediately, it is possible to suppress a decrease in dehydration performance within a normal dehydration time.

  Subsequently, the routine proceeds to step 310, where the final set rotational speed Nmax is set at step 104, and the minimum value Nsmin of the subsequent set rotational speed Ns is stored. In step 311, a dehydration setting time T 1 corresponding to Nsmin is set as shown in FIG. 7, and the process returns in step 312.

  As a result, even when the motor input power Pi is increased and the dehydrating operation is controlled at a low set rotational speed Ns, the dehydrating set time T1 can be increased to suppress a decrease in dewatering performance due to a decrease in the rotational speed. Here, the set time T1 for dewatering is set so that the dewatering performance can be secured even at a low rotation speed.

  A flowchart of the high power detection control subroutine shown in FIG. 8 will be described. From step 400, the high power detection control subroutine starts. In step 401, the same brake control as in step 108 is performed to stop the motor. In step 402, the large current detection number Pct is counted up. In step 403, it is determined whether the large current detection number Pct is equal to or greater than the maximum detection number Ctmax (for example, 10 times). If it is equal to or greater than Ctmax, an abnormality notification is made in step 404 to inform the user that the motor input power Pi is large and the dehydration operation cannot be continued. If it is less than Ctmax, in step 405, the water level is detected again by the water level detecting means 29, and it is determined whether there is water. If there is water, drain in step 406 and continue draining until there is no water. If there is no water, dehydration restart setting is performed in step 407, and the process returns in step 408.

  Thereby, even when the motor input power Pi continues to increase, the motor can be safely stopped before a problem occurs in the motor, the motor drive circuit, and the power supply circuit due to the high power. In particular, when the drainage capacity is poor and the dehydrated water is not drained, and the drainage hose and the lower end of the drum accumulate from the drainage groove and the load is increased, the load due to water can be reduced by continuing drainage. Since the detected water level is fluctuated by the wind pressure generated by the rotating drum during dehydration, the water level detecting means can detect that the water has been drained accurately by detecting the water level after stopping the rotation.

  Furthermore, when this state occurs a plurality of times, an abnormality is notified and an abnormal load state (for example, sandwiching of laundry between the rotating drum and the water receiving tub, excessively heavy laundry, The user can be urged to reduce an excessive load such as residual water in the rotating drum. As a result, the load is reduced, the torque T, the motor output power Po, and the motor input power Pi can be reduced, and a normal dehydrating operation can be performed. Further, when the motor input power Pi is increased due to a failure of the motor, the motor drive circuit, or the power supply circuit, the user can be urged to repair the parts by this abnormality notification.

  The actual operation will be described with reference to the time chart of the rotational speed control and constant power control shown in FIG. 9, and the rotational speed control and high power detection control shown in FIG. FIG. 9 shows a time chart when the rotational speed control is shifted to the constant power control and the rotational speed control is restored. The set rotational speed Ns is increased to point a, and the final set rotational speed Nmax of 900 r / min is reached. The rotational speed control is performed at 900 r / min up to point b where 5 seconds have elapsed with the motor input power Pi exceeding 1000 W, and the control shifts to constant power control at point b. It is controlled to be 1100 W by constant power control, and the set rotational speed Ns varies. When the water in the laundry is drained and drained by dehydration and the load is lightened, the set rotational speed Ns that can be controlled at 1100 W increases, and reaches the maximum value Nmax at the point c. Since Ns does not increase any more, the motor input power Pi starts to decrease. When the motor input power Pi becomes less than 1000 W at the point d, the control shifts to the rotation speed control. Since the minimum value Nsmin of the set rotational speed Ns during constant power control from the point b to the point d is 880 r / min, the set time T1 for dehydration is 500 s. When reaching 500 s at point e, the brake is applied and the dehydrating operation is terminated.

  Next, FIG. 10 shows a time chart when shifting from the rotational speed control to the constant power control and the high power detection control and dehydration is started again. As in FIG. 9, the rotational speed control is performed at point a reaching 900 r / min. Since the motor input power Pi exceeds 1000 W at this point, the control shifts to constant power control at point b after 5 seconds. Since 1100 W is controlled by constant power control, the set rotational speed Ns varies, but when the minimum value Nmin is reached at the point c, Ns does not decrease and the motor input power Pi starts to increase. At a point d, when the motor input power Pi exceeds 1200 W, 1 second elapses, and the process shifts to the large current detection control. Brake control is performed, and after stopping at point e, the number of detections is less than 10, so it is confirmed that there is no water, dehydration restart setting is performed, and restart is performed at point f.

  Next, the flowchart of the motor drive subroutine shown in FIG. 11 will be described. From step 500, the motor drive subroutine starts. In step 501, the initial determination is made at the beginning of the subroutine execution to determine the start or initial braking. If the initial start or the initial braking, various initial settings are performed in step 502, and parameters are transferred from the main routine and various settings are executed. To do. In step 503, rotation start control or braking initial control is performed. Steps 502 and 503 are executed only once at the beginning. In the start control, at the time of start in which the rotation speed feedback control cannot be performed, a predetermined motor applied voltage is set and energized 120 degrees, and soft start is performed to increase the voltage from the low motor applied voltage to the high voltage with time. In the case of braking operation, the negative d-axis current is increased, the negative q-axis current is decreased, and soft braking is performed so that a sudden brake torque is not applied.

  Next, at step 504, the presence / absence of a carrier signal interrupt is determined. The carrier signal interrupt is executed by the interrupt signal ck generated when the carrier counter of the input voltage control means 15 overflows. In step 505, the carrier signal interrupt subroutine shown in FIG.

  Here, the flowchart of the carrier signal interrupt subroutine shown in FIG. 12 will be described. In step 600, the carrier signal interrupt subroutine is started. In step 601, the interrupt signal ck is counted. In step 602, the rotor position electrical angle θ is calculated. As the rotor position signal θ, a value k · Δθ obtained by multiplying the separately obtained electrical angle Δθ per cycle of the carrier signal and the count value k of the carrier counter is added to the electrical angle φ every 60 degrees that can be detected by the position detecting means 8. The estimation is calculated. For example, if the motor 4 has 4 poles, the ratio of the drum pulley 3 to the motor pulley is 8.25: 1, the carrier frequency is 15.6 kHz, and the rotation speed is 900 r / min, the motor drive frequency is 240 Hz, and the electrical angle is within 60 degrees. The carrier counter count value k is about 11. Therefore, Δθ is about 5.5 degrees. As the motor rotational speed is lower, the count value k within an electrical angle of 60 degrees is higher, and the electrical angle detection resolution in calculation is improved. Therefore, it can be understood that there is no problem even when the rotational speed is low and accuracy is required.

  Next, in step 603, motor currents Iu, Iv, and Iw are detected. In step 604, the three-phase / 2-phase dq conversion is performed by the calculation of (Equation 1) from the electrical angle θ and the motor current to obtain the d-axis current Id and the q-axis current Iq. In step 605, Id and Iq are stored in memory and used separately as rotation speed control data.

  Next, in step 606, the d-axis control voltage Vd and the q-axis control voltage Vq are called, and in step 607, two-phase / three-phase dq inverse conversion is performed by the calculation of (Equation 2), and the three-phase control voltages Vu, Vv, Vw. Ask for. This inverse transformation uses sin θ and cos θ data corresponding to the electrical angle of the storage means 13 as in step 604 and performs a product-sum operation at high speed. In step 608, the PWM output values PWMu, PWMv, and PWMw corresponding to the three-phase control voltages Vu, Vv, and Vw are converted, and in step 609, PWM output is performed. In step 610, the three-phase PWM output values PWMu, PWMv, and PWMw are stored in memory and used in the next carrier signal interrupt. In step 611, the subroutine is returned.

  As described in FIG. 2, the PWM control is performed by comparing the sawtooth wave (or triangular wave) carrier signal with the control voltages Vu, Vv, and Vw in correspondence with the U phase, V phase, and W phase. The IGBT on / off control signal of the circuit 7 is generated and the motor 4 is driven in a sine wave. The signals of the upper arm transistor and the lower arm transistor are inverted waveforms. When the conduction ratio of the upper arm transistor is increased, the output voltage becomes positive. When the voltage is increased and the conduction ratio of the lower arm transistor is increased, the output voltage becomes a negative voltage. When the conduction ratio is 50%, the output voltage becomes zero.

  When the control voltage is changed in a sine wave shape corresponding to the electrical angle θ, a sine wave current flows. In the case of sine wave drive, when the transistor conduction ratio is set to the maximum value of 100%, the output voltage is maximum and the modulation degree Am is 100%. When the maximum value of the conduction ratio is 50%, the output voltage is minimum and the modulation is performed. The degree Am is called 0%.

  Since 3-phase / 2-phase dq conversion and 2-phase / 3-phase dq reverse conversion for vector control of motor current are executed at high speed for each carrier, high-speed current control becomes possible, and torque current for each carrier. Since Iq is detected, the load amount can be determined instantaneously.

  After executing the carrier signal interrupt subroutine, returning to FIG. 11, it is determined in step 506 whether or not there is a position signal interrupt. When any one of the position signals H1, H2, and H3 changes, an interrupt signal is generated, and the position signal interrupt subroutine shown in FIG. As shown in FIG. 2, an interrupt signal is generated every 60 electrical angles.

  Here, the flowchart of the position signal interrupt subroutine shown in FIG. 13 will be described. In step 700, the position signal interrupt subroutine is started. In step 701, position signals H1, H2, and H3 are input to detect the position. In step 702, the rotor electrical angle θc is detected from the position signal. Proceeding to step 703, the count value k counted in the carrier signal interruption subroutine is stored in kc, the count value k is cleared in step 704, and in step 705, the carrier counter count value kc between 60 electrical angles is set to 1. The electrical angle Δθ of the carrier is calculated.

  Next, in step 706, it is determined whether or not the interrupt signal is based on the reference position signal H1, and if it is a reference position signal interrupt, in step 707, the count value T of the rotation period measuring timer T is stored as the period To, and in step 708 the timer is counted. T is cleared, and in step 709, the motor speed n is calculated. Next, in step 710, counting of the rotation period measurement timer is started, and in step 711, the subroutine is returned.

  If the detection resolution of the rotation period measurement timer is set to 8-bit accuracy, the clock becomes 64 μs and the carrier signal can be used as the clock. However, in order to improve the rotation control performance, it is necessary to improve the rotation period detection resolution. It is necessary to set to 1 to 10 μs. In this case, the microcomputer system clock is divided and used as the clock.

  Although the rotation speed detection method described above has shown the method of calculating | requiring from the period of the position signal H1, you may use all the position signals H1, H2, and H3. If the carrier signal is a triangular wave, the carrier counter timer has a period twice that of the sawtooth wave. Therefore, if the triangular wave overflow signal is used as a clock, the resolution is improved. Therefore, the triangular wave timer overflow signal may be used as a clock.

  After executing the position signal interrupt subroutine, returning to FIG. 11, the rotational speed control subroutine is executed at step 508. In step 509, the subroutine is returned.

  Here, the flowchart of the rotation speed control subroutine shown in FIG. 14 will be described. A rotational speed control subroutine is started from step 800, the motor rotational speed n is called in step 801, and a flag determination is made in step 802 as to whether normal driving or deceleration braking.

  In the case of normal driving, torque control is performed by controlling the q-axis current set value Iqs in step 803 based on the error between the set rotational speed Ns and the detected rotational speed n, and in step 804 the q-axis current set value Iqs is compared with the upper limit value Iqmax. If Iqs> Iqmax, Iqs is set to Iqmax in step 805 so that the q-axis current Iq does not exceed the upper limit value Iqmax. If Iqs ≦ Iqmax, step 805 is skipped.

  In the case of deceleration braking, in step 806, the q-axis current set value is set to -Iqs for negative torque control, that is, brake torque control.

  Next, in step 807, the phase angle δ is set from the set rotational speed Ns, and in step 808, the d-axis current set value Ids is calculated from Iqs and the phase angle δ. When the d-axis current is controlled only with the set rotation speed Ns, if the q-axis current Iq is small, the advance angle is excessive and torque may not be obtained. Therefore, d corresponding to the set rotation speed Ns and the q-axis current set value Iqs It is necessary to set the shaft current.

  Next, in step 809, the d-axis current Id is called, and in step 810, Id and Ids are compared in magnitude. If the d-axis current Id is larger than the set value Ids, the d-axis control voltage Vd is decreased in step 811. If the shaft current Id is smaller than the set value Ids, the d-axis control voltage Vd is increased in step 812.

  Next, in step 813, the q-axis current Iq is called, and in step 814, the magnitude comparison between Iq and Iqs is performed. If the q-axis current Iq is larger than the set value Iqs, the q-axis control pressure Vq is decreased in step 815, and q If the shaft current Iq is smaller than the set value Iqs, the q-axis control voltage Vq is increased in step 816.

  Next, the d-axis control voltage Vd and the q-axis control voltage Vq calculated in step 817 are stored in memory, and the subroutine is returned in step 818.

  Since the d-axis current Id and the q-axis current Iq are basically converted for each carrier signal, fluctuations including torque ripple are large. If the converted d-axis current Id and q-axis current Iq and the set values Ids and Iqs are compared and determined for each carrier, the fluctuation element is large and the control is not stable. Therefore, it is necessary to add an integration element such as averaging.

  Therefore, as shown in FIG. 13, the rotation speed control subroutine is not executed in the carrier signal interruption subroutine or the position signal interruption subroutine, but is executed independently in the motor drive control. However, in order to increase the response speed of the rotation control, a method performed in the position signal interruption subroutine is also conceivable, but there is a drawback that the response is delayed when the rotation speed is low.

  The above is an example of a belt-driven washing machine in which a rotating drum is driven by a belt. However, even in a direct-drive washing machine in which a rotating drum and a motor are coaxial, the drum rotation speed is the motor rotation speed. Thus, when a high load is applied to the motor, it is possible to control the motor input power within an allowable range to protect the motor, the motor drive circuit, and the power supply circuit, and to suppress a decrease in dewatering performance.

  Although the above description is based on a drum type washing machine as an example, even in a pulsator type vertical washing machine in which the rotational drive shaft of the motor is connected to a stirring blade or a washing and dewatering tub by a clutch, a high load is applied to the motor. In this case, it is possible to control the motor input power within an allowable range to protect the motor, the motor drive circuit, and the power supply circuit, and to suppress a decrease in dewatering performance.

  As described above, the washing machine according to the present invention protects the motor, the motor drive circuit, and the power supply circuit by controlling the motor input power within an allowable range when a high load is applied to the motor, and performs dehydration. Useful for washing machines that suppress performance degradation.

DESCRIPTION OF SYMBOLS 1 Rotating drum 2 Water receiving tank 4 Motor 6 Rectification circuit 7 Inverter circuit 8 Position detection means 9 Current detection means 10 Control means 15 Input voltage control means 18 Speed control means 23 Notification means 25 Drain valve (drainage means)
29 Water level detection means 30a Power supply current detection means 30b Power supply voltage detection means 32 Motor power detection means

Claims (8)

A rotating drum that accommodates laundry and is rotationally driven, an inverter circuit that converts DC power rectified by a rectifying circuit into AC power, a motor that drives the rotating drum by the inverter circuit, and a rotor of the motor Position detection means for detecting the position, rotation speed control means for controlling the rotation speed so that the motor has a set rotation speed, motor power detection means for detecting the power input to the motor, washing, rinsing, Control means for controlling at least one or more strokes of each process of dehydration, the control means when the motor input power exceeds the first predetermined power for a first predetermined time or more during the dehydration operation, A washing machine characterized by controlling the motor input power to be a constant power by changing the set rotational speed. An input voltage control means for controlling an input voltage of the motor; and a current detection means for detecting an input current of the motor, wherein the motor power detection means is a motor input at a rotational coordinate synchronized with a rotor of the motor. The washing machine according to claim 1, wherein the motor input power is calculated from the components of the voltage and the motor input current. The washing machine according to claim 2, wherein the motor power detection means calculates motor input power from a component of a motor input voltage and a motor input current at a stationary coordinate. A power supply current detection means for detecting a power supply input current flowing in the power supply circuit; and a power supply voltage detection means for detecting a power supply input voltage applied to the power supply circuit, wherein the motor power detection means comprises the power supply input voltage and the power supply input. The washing machine according to any one of claims 1 to 3, wherein power input power is calculated from a current component, and motor input power is calculated at a predetermined ratio from the power input power. The washing machine according to any one of claims 1 to 4, wherein the control means extends a dehydration set time in accordance with a decrease in the set rotation speed. When the motor input power exceeds a second predetermined power greater than the first predetermined power for a second predetermined time or longer, the control means stops the dehydrating operation and performs the same dehydrating operation again. The washing machine according to any one of claims 1 to 5. Water level detection means for detecting the water level in the water receiving tank and drainage means for draining the water in the water receiving tank, and the control means detects the water level when the dehydrating operation is stopped due to an increase in motor input power. The washing machine according to claim 6, wherein drainage is continued until drainage is completed, and dewatering operation is started after drainage. Informing means for performing a notifying operation, wherein the control means stops the dehydrating operation due to an increase in motor input power, and when the dehydrating operation to be performed again reaches a predetermined number of times, the notifying means notifies the abnormality. The washing machine according to claim 6 or 7.

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