WO2021019977A1

WO2021019977A1 - Washing machine

Info

Publication number: WO2021019977A1
Application number: PCT/JP2020/024939
Authority: WO
Inventors: 昊孫; 中尾　浩; 亀田　晃史; 冉王; 高橋　新
Original assignee: パナソニックＩｐマネジメント株式会社
Priority date: 2019-07-29
Filing date: 2020-06-25
Publication date: 2021-02-04
Also published as: TW202108840A; JP7324971B2; JP2021019916A; CN114144552A

Abstract

This drum-type washing machine comprises: a rotary tub; a motor (7) which rotationally drives the rotary tub; an inverter circuit (24) which converts direct current into alternating current and drives the motor (7); and a current detection unit which detects the current flowing through the motor (7). The drum-type washing machine further comprises: a low-pass filter processing unit (33) which performs low-pass filter processing on the current detected by the current detection unit and outputs the low-pass filtered value as a processed current value; an overload detection unit (34) which detects the overload state of the motor (7); and a control unit (31) which transmits a motor drive command to the inverter circuit (24) and controls the motor (7) through the inverter circuit (24). Further, the overload detection unit (34) determines the overload state of the motor (7) on the basis of the processed current value output by the low-pass filter processing unit (33), and the control unit (31) controls the rotational drive of the motor (7) on the basis of the determination result of the overload detection unit (34).

Description

Washing machine

This disclosure relates to a washing machine.

Conventionally, a washing machine that detects the temperature of the winding of the stator with a thermistor has been proposed.

This washing machine is provided with a water tank, a rotary tank rotatably arranged inside the water tank, a motor for rotating the rotary tank, and a control circuit for controlling the motor and the like. The motor is composed of a rotor having a ring-shaped permanent magnet and a stator having a three-phase winding, and a thermistor which is a temperature detecting means is arranged in the vicinity of the winding of the stator. The control circuit detects the temperature of the winding of the stator by the voltage of the thermistor (see, for example, Patent Document 1).

JP-A-11-239688

However, parts such as thermistors are expensive, and there is a problem that the manufacturing cost is high.

The present disclosure provides a washing machine that improves the safety of the motor with an inexpensive configuration.

The washing machine in the present disclosure includes a rotary tub, a motor that rotationally drives the rotary tub, an inverter circuit that converts a direct current into an alternating current to drive the motor, and a current detector that detects the current flowing through the motor. Be prepared. In addition, a low-pass filter unit that performs low-pass filter processing on the current detected by the current detection unit and outputs the low-pass filtered value as the processed current value, and an overload detection unit that detects the overload state of the motor. It includes a control unit that transmits a motor drive command to the inverter circuit and controls the motor through the front inverter circuit. Further, the overload detection unit determines the overload state of the motor based on the processed current value output by the low-pass filter unit, and the control unit determines the overload state of the motor based on the determination result of the overload detection unit. Controls rotational drive.

The washing machine in the present disclosure improves the safety of the motor due to its inexpensive configuration.

FIG. 1 is a vertical cross-sectional view showing a schematic configuration of a washing machine according to the first embodiment. FIG. 2 is a block diagram showing a circuit configuration of the washing machine according to the first embodiment. FIG. 3 is a characteristic diagram of the motor winding temperature at each current value of the motor of the washing machine according to the first embodiment. FIG. 4 is a flowchart of the overload state detection process of the motor of the washing machine according to the first embodiment. FIG. 5 is a flowchart of the inverter control process of the motor of the washing machine according to the first embodiment. FIG. 6 is a diagram showing the relationship between the motor current (after low-pass filter processing) of the washing machine and the motor drive command according to the first embodiment. FIG. 7 is a flowchart of the inverter control process of the motor of the washing machine according to the second embodiment.

Hereinafter, embodiments will be described in detail with reference to the drawings. The present invention is not limited by the accompanying drawings and the following description.

(First Embodiment)
Hereinafter, the first embodiment will be described with reference to FIGS. 1 to 6.

(Basic configuration of washing machine)
FIG. 1 is a vertical cross-sectional view showing a schematic configuration of a washing machine according to the first embodiment.

As shown in FIG. 1, inside the washing machine main body 1, a water tank 2 formed in a bottomed cylindrical shape is elastically supported by a suspension structure (not shown). The water tank 2 is supported by tilting its axial direction downward from the front side (left side in FIG. 1) to the back side (right side in FIG. 1). Inside the water tank 2, a rotary tank 3 formed in a bottomed cylindrical shape is rotatably arranged. On the inner wall surface of the rotary tub 3, a plurality of water passage holes 6 for passing washing water to the inside and outside of the rotary tub 3 and a plurality of stirring protrusions (not shown) for stirring clothes are formed.

A donut-shaped fluid balancer 15 is arranged on the front side of the rotary tank 3. The fluid balancer 15 is divided into a plurality of storage chambers (not shown) by a plurality of partition plates provided in the circumferential direction, and each partition plate is formed with a communication hole. A liquid having a large specific gravity, such as calcium chloride, is stored inside the fluid balancer 15. Liquid can move from one storage chamber to the next through the communication holes. If the laundry inside the rotary tub 3 is biased during the washing operation, an eccentric load is generated on the rotary tub 3. The liquid moves to the opposite side of the eccentric load to correct the deviation of the center of gravity and reduce the vibration noise of the rotary tank 3.

A clothes entrance 4 leading to the opening end of the rotary tub 3 is formed on the front side of the washing machine main body 1, and the clothes entrance 4 is covered with a door 5 so as to be openable and closable. The user can put in and take out the laundry in the rotary tub 3 through the clothes entrance 4 with the door 5 open. An operation display panel 10 which is an input setting unit 25 (see FIG. 2) is provided on the upper part of the front surface of the washing machine main body 1 which is above the clothes entrance 4. The user can set a desired driving course by operating the operation display panel 10.

The motor 7 is arranged in the lower part of the water tank 2. The motor 7 is connected to a rotation center shaft 17 provided at the lower bottom of the rotary tank 3 via a pulley 14 and a belt 16. The rotational driving force of the motor 7 is transmitted to the rotary tank 3 via the pulley 14 and the belt 16 to rotate the rotary tank 3 in the forward or reverse direction.

The water injection pipe 8 is connected to the upper part of the water tank 2, and the drainage pipe 9 is connected to the lower part of the water tank 2. A water supply valve 27 and a drain valve 28 are provided in the water injection pipe line 8 and the drainage pipe line 9 so as to be openable and closable. By opening the water supply valve 27 and the drain valve 28, water injection and drainage into the water tank 2 are executed.

(Composition of motor drive device)
FIG. 2 is a block diagram showing a circuit configuration of the washing machine according to the first embodiment.

As shown in FIG. 2, the circuit for driving the motor 7 is provided with a rectifier 21, a choke coil 22, and a smoothing capacitor 23. The AC voltage of the commercial power supply 20 is rectified by the rectifier 21. The rectified AC power is converted into a DC voltage by a smoothing circuit including a choke coil 22 and a smoothing capacitor 23. Therefore, the converted DC voltage is applied to the inverter circuit 24.

The inverter circuit 24 is composed of a three-phase full-bridge inverter circuit composed of six power switching semiconductors 24a to 24f and an antiparallel diode. In the present embodiment, the inverter circuit 24 is composed of an insulated gate bipolar transistor (IGBT), an antiparallel diode, and an intelligent power module (hereinafter referred to as IPM) incorporating a drive circuit and a protection circuit thereof. A motor 7 is connected to the output terminal of the inverter circuit 24. Further, the inverter circuit 24 controls the operation of the water supply valve 27, the drain valve 28, the blower fan 12, and the heat pump 29 by the load drive unit 26 based on the operation instruction and the monitoring information.

The motor 7 is a brushless motor. The motor 7 includes a permanent magnet constituting a rotor, a stator, and a rotor position detecting unit composed of three Hall ICs, Hall IC30a, Hall IC30b, and Hall IC30c. The Hall IC 30a, Hall IC 30b, and Hall IC 30c detect a position output reference signal for each 60 degree electric angle from the relative position (rotor position) between the permanent magnet and the stator.

The current detecting means in the present embodiment is composed of a shunt resistor (not shown) and is provided in the inverter circuit 24. The current detecting means detects the motor currents Iu, Iv, and Iw of the motor 7.

The control unit 31 is composed of a microcomputer, 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. The control unit 31 detects the electric angle from the output signals of the hall IC 30a, the hall IC 30b, and the hall IC 30c that constitute the rotor position detection unit. Further, the control unit 31 performs 3-phase / 2-phase dq conversion that decomposes the current component Id corresponding to the magnetic flux and the current component Iq corresponding to the torque, and 3 the voltage component Vd corresponding to the magnetic flux and the voltage component Vq corresponding to the torque. The 2-phase / 3-phase dq inverse conversion that converts the phase motor drive control voltage Vu, Vv, Vw is performed, and the switching of the IGBT of the drive circuit 32 is PWM-controlled according to the 3-phase motor drive control voltage Vu, Vv, Vw. As a result, the control unit 31 controls energization of the

windings

7a, 7b, and 7c, which are the three-phase windings of the stator, and rotates the motor 7 at a required rotation speed.

In the present embodiment, the microcomputer of the control unit 31 plays the roles of the low-pass filter processing unit 33 and the overload detection unit 34. The detailed operation of the low-pass filter processing unit 33 and the overload detection unit 34 will be described later.

(Basic operation of washing operation)
The user opens the door 5, puts the laundry and the detergent into the rotary tub 3, and operates the operation display panel 10 which is the input setting unit 25 to start the operation. When the operation starts, the control unit 31 opens the water supply valve 27 and injects water into the water tank 2. When the predetermined water level is reached, the control unit 31 closes the water supply valve 27 and starts the washing operation.

In the washing operation, the control unit 31 rotates the rotary tank 3 by rotationally driving the motor 7. The laundry housed in the rotary tub 3 is lifted in the rotational direction by the stirring protrusions as the rotary tub 3 rotates, and is dropped from an appropriate height position and stirred. In this way, in the washing operation, the dirt is removed by tapping the laundry by lifting and dropping it.

When a predetermined time elapses in the washing operation, the control unit 31 opens the drain valve 28 and discharges the dirty washing liquid from the drain pipe line 9. Subsequently, the control unit 31 dehydrates the washing liquid contained in the laundry by a dehydrating operation of rotating the rotary tub 3 at high speed.

(Relationship between motor current value and motor winding temperature)
When the clothes are excessively stored in the rotary tank 3, there is a problem that the clothes are twisted or bitten during the rotation operation of the rotary tank 3 and an excessive load is applied to the motor 7. In a state where the motor 7 is overloaded, that is, in a motor overloaded state, the current value flowing through the motor 7, that is, the motor current value becomes higher than the motor current value during normal washing operation.

FIG. 3 is a characteristic diagram of the motor winding temperature at each current value of the motor of the washing machine according to the first embodiment.

The motor winding temperature is the temperature of the

windings

7a, 7b, and 7c, which are three-phase windings. In FIG. 3, the horizontal axis represents the operating time and the vertical axis represents the motor winding temperature, and the change in the motor winding temperature at each current value is shown. Each current value is set to a predetermined value so as to decrease in the order of motor current A, motor current B, motor current C, and motor current D.

Generally, the motor winding temperature rises in proportion to the square of the motor current value, and after a certain period of time, the motor winding temperature saturates. If this saturation temperature exceeds the heat resistant temperature of the motor winding, the motor winding may burn out. Therefore, it is necessary to control the motor current value so that the motor winding temperature does not exceed the heat resistant temperature.

In the present embodiment, the current value at which the winding saturation temperature may exceed the heat resistant temperature of the motor winding is experimentally measured in advance, and a predetermined threshold value is set based on the current value. When a predetermined time elapses while the motor current value exceeds a predetermined threshold value, it is defined as a motor overload state.

(Overload state detection processing and inverter control processing)
FIG. 4 is a flowchart of the overload state detection process of the washing machine motor according to the first embodiment, and FIG. 5 is a flowchart of the inverter control process of the washing machine motor according to the first embodiment.

In the washing operation, the control unit 31 starts the overload state detection process (step S101) and also starts the inverter control process shown in FIG. The two processes are performed independently in parallel, and are repeatedly executed at their respective time intervals.

First, the overload state detection process will be explained.

As shown in FIG. 4, when the overload state detection process is started (step S101), the overload detection unit 34 performs a low-pass filter process of the motor current value (step S102).

In the low-pass filter processing in the present embodiment, the change between the previous motor current value and the current motor current value is calculated, the change is reduced by a constant ratio, and the change is added to the previously detected current. These processes are arithmetically processed by the low-pass filter processing unit 33, which is a microcomputer. In general, it is known that the current value that flows when the motor is started becomes a large current value momentarily and gradually converges to a constant value. By performing the low-pass filter processing, the component due to the input current can be removed from the measured value of the motor current value, and the false detection of the overload state due to the instantaneous large current flowing can be suppressed. The time constant of the low-pass filter is set to a time (for example, 10 seconds) that is substantially equivalent to the ON time of the motor drive.

Next, the overload detection unit 34 compares the motor current value after the low-pass filter processing with the threshold value α to determine whether the motor is in the overload state (step S103). In S103, when the motor current value is less than α (steps S103, No), or when the motor current value is α or more and the predetermined time t1 has not elapsed (steps S103, No), the overload state detection process (Step S107). As a result, when the motor current value momentarily becomes α or more, it is possible to prevent erroneous detection of a motor overload state.

In step S103, when the predetermined time t1 elapses with the motor current value being α or more (step S103, Yes), the overload detection unit 34 sets the motor overload state, that is, the motor is in the overload state. If there is, it is set (step S104).

As mentioned above, in the motor overload state, the motor winding temperature may exceed the heat resistant temperature. Therefore, the motor winding must be allowed to cool until the motor current value after the low-pass filter processing becomes equal to or less than a predetermined value. In the present embodiment, the threshold value β, which is one-third of the threshold value α, is provided, and if the motor current value is equal to or less than the threshold value β, it is determined that the motor is not in the overloaded state.

The overload detection unit 34 compares the motor current value after the low-pass filter processing with the threshold value β (step S105). In step S105, if the motor current value exceeds the threshold value β (steps S105, No), the overload state detection process ends (step S107).

In step S105, if the motor current value is equal to or less than the threshold value β (step S105, Yes), the motor overload state is cleared, that is, the determination that the motor is overloaded state is canceled (step S106). After that, the overload state detection process is terminated (step S107).

Next, the inverter control process will be described.

As shown in FIG. 5, the control unit 31 starts the inverter control process (step S201). The control unit 31 causes the drive circuit 32 to PWM control the switching of the IGBT by issuing a motor drive command (step S202). As a result, the motor 7 rotationally drives the rotary tank 3 based on the motor drive command.

When the motor overload state is set in step S203 (step S203, Yes), the control unit 31 stops the PWM output in the drive circuit 32 (step S204). After that, the inverter control process is terminated (step S205). If the motor overload state is not set (step S203, No), the inverter control process ends (step S205).

Next, the characteristics of the motor current value (after low-pass filter processing) and the motor drive command in this embodiment will be described.

FIG. 6 is a diagram showing the relationship between the motor current (after low-pass filter processing) of the washing machine and the motor drive command in the first embodiment. The horizontal axis is the operating time, the left vertical axis is the motor current value after low-pass filter processing, and the right vertical axis is the motor drive command.

The stirring period during washing is set to 1 cycle for 10 seconds in the ON state and 1 second in the OFF state, and the stirring operation is performed while flipping left and right for each cycle. At this time, the motor current value after the low-pass filter processing rises while vibrating up and down when stirring is ON, and gradually decreases when stirring is OFF. When the motor overload state is set in the overload state detection process shown in FIG. 4 (step S104), the PWM output is stopped in the inverter control process shown in FIG. 5 (step S204). Since the motor current does not flow during the period when the PWM output is stopped, the motor current value after the low-pass filter processing gradually decreases.

It is known that the motor current value after the low-pass filter processing takes longer to decrease as the motor current value increases. Therefore, when the motor current value is large, the time until the motor current value becomes the threshold value β or less becomes long, and as a result, the period during which the motor drive is stopped becomes long. As a result, even if the motor current value suddenly rises by the time t1 elapses in a state where the motor current value is equal to or higher than the threshold value α, the cooling time becomes longer according to the motor current value, so that the motor winding The temperature can be lowered more reliably.

When the motor current value after the low-pass filter processing falls below the threshold value β, the motor overload state is cleared in the overload state detection process shown in FIG. 4 (step S106). Then, the PMW output is restarted in the inverter control process shown in FIG. 5 (step S202).

As described above, the motor safety function can be realized at a lower cost than before by detecting the motor overload state based on the motor current after the low-pass filter processing and suppressing the motor winding temperature within the heat resistant temperature.

(Action, etc.)
The drum-type washing machine according to this embodiment has a rotary tub 3, a motor 7 that rotationally drives the rotary tub 3, an inverter circuit 24 that converts a direct current into an alternating current and drives the motor 7, and a motor 7. It includes a current detection unit that detects a current. Further, the low-pass filter processing unit 33 that performs low-pass filter processing on the current detected by the current detection unit and outputs the low-pass filtered value as the processed current value, and the overload detection that detects the overload state of the motor 7. A unit 34 and a control unit 31 that transmits a motor drive command to the inverter circuit 24 and controls the motor 7 through the inverter circuit 24 are provided.

Further, the overload detection unit 34 determines that the motor 7 is in an overload state based on the processed current value output by the low-pass filter processing unit 33, and the control unit 31 determines that the overload detection unit 34 is in an overload state. The rotational drive of the motor 7 is controlled based on the determination result.

With this configuration, it is possible to detect an increase in the motor winding temperature from changes in the motor current value without installing separate parts such as a thermal fuse and thermistor. Therefore, it is possible to suppress the excessive rise in the motor winding temperature and realize the safety of the motor at low cost.

Further, as in the present embodiment, the overload detection unit 34 states that the motor 7 is in an overload state when a predetermined time elapses in a state where the processed current value is α or more, which is the first value. The motor overload state may be released when it is determined that the current value is present and the processed current value is β, which is a second value smaller than α, which is the first value.

With this configuration, the time from when the motor 7 is determined to be in the overload state and the drive is stopped until the motor current value falls below β becomes longer as the motor current value increases. Therefore, when the winding temperature is likely to be high, the heat dissipation time can be long, so that the safety of the motor can be realized at low cost.

(Second Embodiment)
The washing machine according to the second embodiment is different from the washing machine 100 according to the first embodiment in the inverter control process during the dehydration operation. Hereinafter, the second embodiment will be described with reference to the same reference numerals for the same configurations as those of the first embodiment.

FIG. 7 is a flowchart of the inverter control process of the motor of the washing machine according to the second embodiment.

The control unit 31 starts the inverter control process (step S301). The control unit 31 determines whether or not the PWM output stop history is set, that is, whether or not the history of stopping due to the motor overload state is set in the previous inverter control process (step S302). .. When the PWM output stop history is set (step S302, Yes), a motor drive command is transmitted so that the rotation speed of the motor 7 decreases (step S303). For example, when an overload state is detected when the dehydration rotation speed is 1400 rpm, the dehydration rotation speed is reduced to 1300 rpm in the next inverter control process.

In step S304, the control unit 31 clears the PWM output stop history, that is, cancels the history of stopping due to the motor overload state in the previous inverter control process (step S304).

In step S305, the drive circuit 32 outputs PWM according to the motor drive command received from the control unit 31 (step S305).

In step 306, the control unit 31 refers to the motor overload state (S306). When the motor overload state is set (step S306, Yes), the PWM output is stopped in the drive circuit 32 (step S307), and the PWM output stop history is set (step S308). After that, the inverter control process is terminated (step S309). When the predetermined time elapses, the next inverter control process is started (step S301).

By repeating the above inverter control processes (steps S301 to S309), the rotation speed of the motor 7 is adjusted so that the motor current value becomes equal to or less than the overload current value.

In particular, in the dehydration operation, the weakening magnetic flux is controlled according to the increase in the motor-induced voltage, so the motor current increases as the rotation speed increases. Therefore, by adjusting the rotation speed of the motor 7, it is possible to effectively suppress an excessive rise in the motor winding temperature.

(Action, etc.)
The drum-type washing machine according to this embodiment has a rotary tub 3, a motor 7 that rotationally drives the rotary tub 3, an inverter circuit 24 that converts a direct current into an alternating current and drives the motor 7, and a motor 7. It includes a current detection unit that detects a current. Further, the low-pass filter processing unit 33 that performs low-pass filter processing on the current detected by the current detection unit and outputs the low-pass filtered value as the processed current value, and the overload detection that detects the overload state of the motor 7. A unit 34 and a control unit 31 that transmits a motor drive command to the inverter circuit 24 and controls the motor 7 through the inverter circuit 24 are provided. Further, the overload detection unit 34 determines that the motor 7 is in the overload state based on the processed current value output by the low-pass filter processing unit 33, and the control unit 31 determines that the motor 7 is in the overload state, and the control unit 31 is in the overload state in the dehydration operation. If is, the rotation speed of the motor 7 is reduced.

With this configuration, in the dehydration operation in which the motor current increases as the rotation speed increases, it is possible to effectively suppress an excessive increase in the motor winding temperature by adjusting the rotation speed of the motor 7.

(Other embodiments)
As described above, the first embodiment and the second embodiment have been described as examples of the techniques disclosed in the present application. However, the techniques in this disclosure are not limited to this.

Therefore, other embodiments will be illustrated below.

In the first embodiment and the second embodiment, the rotary tub type washing machine has been described as an example of the washing machine. However, the washing machine may be any one in which the rotary tub is rotationally driven by a motor. Therefore, the washing machine is not limited to the drum type washing machine, and may be a vertical type washing machine or a two-tank type washing machine.

In the first embodiment and the second embodiment, the IGBT has been described as an example of the power switching semiconductor. The power switching semiconductor may be composed of a metal oxide film semiconductor field effect transistor (MOSFET) or the like.

In the first embodiment and the second embodiment, the shunt resistance has been described as an example of the current detection unit. However, the current detection unit may use a method of measuring a DC current transformer or an AC current transformer from a low frequency including a DC current. Further, in the case of a three-phase motor, a method of obtaining a two-phase current and obtaining the remaining one phase from Kirchhoff's law (Iu + Iv + Iw = 0) may be used.

In the first embodiment and the second embodiment, as an example of the rotor position detection unit, the rotor position detection unit 30 that detects the rotor position based on the output reference signals H1 to H3 by the Hall IC has been described. However, the rotor position detection unit is not limited to the one using the Hall IC. The rotor position detection unit may detect the rotor position by calculation from the phase current of the motor and the three-phase motor drive control voltage.

In the first embodiment and the second embodiment, the arithmetic processing in the microcomputer has been described as an example of the low-pass filter unit, but the present invention is not limited to this. A low-pass filter configuration may be realized on the circuit by using a resistor and a capacitor as the low-pass filter unit. Further, in the first embodiment and the second embodiment, as an example of the low-pass filter processing, the change amount between the previous motor current value and the current motor current value is calculated, and the change amount is reduced by a constant ratio. Then, the configuration added to the previously detected current was explained. However, the low-pass filter processing is not limited to this method. For example, a simple moving average value may be used.

In the first embodiment and the second embodiment, the low-pass filter processing (S102) performed as a part of the overload state detection processing has been described as an example of the low-pass filter processing. The timing of executing the low-pass filter processing is not limited to step 102, and may be executed independently of the overload state detection processing.

In the first embodiment and the second embodiment, the threshold value β, which is one-third of the threshold value α, has been described as a reference value for determining that the motor is not in an overloaded state. However, the reference value is not limited to one-third of the threshold value α as long as it can be determined that the motor is not overloaded.

In the first embodiment, as an example of controlling the rotation drive of the motor in the motor overload state, an example of stopping the drive of the motor 7 in the motor overload state has been described. However, the control of the rotary drive of the motor in the motor overload state is not limited to the stop of the drive. For example, the stirring time during washing may be changed, the ON state time may be shortened, and the OFF state time may be lengthened.

In the first embodiment, as a method of controlling the rotational drive of the motor based on the determination result of the overload detection unit, an example of stopping the drive of the motor 7 in the motor overload state has been described. However, the method of controlling the rotational drive of the motor is not limited to the drive stop of the motor 7 in the motor overload state, and may be the stop of the washing operation. For example, when it is determined that the motor is overloaded a predetermined number of times or more, it may be determined that the motor 7 has an abnormality. If it is determined that the motor 7 has an abnormality, the washing operation may be stopped to notify the abnormality.

The present disclosure is applicable to a device for rotationally driving a rotary tank with a motor. Specifically, the present disclosure is applicable to vertical washing machines, drum-type washing machines, two-tank washing machines, and the like.

1 Washing machine body 2 Water tank 3 Rotating tank 4 Clothes entrance 5 Door 6 Water passage hole 7

Motor

7a, 7b, 7c Winding 8 Water injection pipeline 9 Drainage pipeline 10 Operation display panel 12 Blower fan 14 Pulley 15 Fluid balancer 16 Belt 17 Center of rotation 20 Commercial power supply 21 Rectifier 22 Choke coil 23 Smoothing capacitor 24 Inverter circuit 24a to 24f Power switch Semiconductor 25 Input setting unit 26 Load drive unit 27 Water supply valve 28 Drain valve 29 Heat pump 30

Rotor position detector

30a, 30b, 30c hole IC
31 Control unit 32 Drive circuit 33 Low-pass filter processing unit 34 Overload detection unit

Claims

Rotating tank and
A motor that rotationally drives the rotary tank and
An inverter circuit that converts direct current into alternating current and drives the motor,
A current detector that detects the current flowing through the motor,
A low-pass filter unit that performs low-pass filter processing on the current detected by the current detection unit and outputs the processed value as a processed current value.
An overload detection unit that detects the overload state of the motor, and
A control unit that transmits a motor drive command to the inverter circuit and controls the motor through the inverter circuit.
With
The overload detection unit determines that the motor is in an overload state based on the processed current value output by the low-pass filter unit.
The control unit controls the rotational drive of the motor based on the determination result of the overload detection unit.
Washing machine.
The overload detection unit determines that the motor is in an overload state when a predetermined time elapses in a state where the current value after the processing is equal to or higher than the first value.
When the current value after the processing is a second value smaller than the first value, the overload state is released.
The washing machine according to claim 1.
When the control unit is in an overloaded state in the dehydration operation, the control unit reduces the rotation speed of the motor.
The washing machine according to any one of claims 1 or 2.