KR101470628B1 - Motor, washing machine comprising the motor and method of controlling the washing machine - Google Patents

Abstract

The present invention relates to a motor, a washing machine including the same, and a control method thereof. In the present invention, the motor is controlled by abbreviated operation according to the variation of the load in the drying cycle. Therefore, according to the motor, the washing machine including the same, and the control method therefor according to the present invention, there is an advantage that the driving of the motor can be controlled in accordance with the variation of the load during the drying stroke.

Washing machine, motor, abbreviated control

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor, a washing machine including the same,

The present invention relates to a motor, and more particularly, to a motor used in a washing machine, a washing machine including the motor, and a control method thereof.

The motor provides rotational force of the rotor by electromagnetic interaction between a stator and a rotor, and is used in a household appliance such as a washing machine. Such a washing machine is a household appliance for washing / drying laundry, and a drum washing machine has recently been released. In the drum type washing machine, a drum in which a washing bag is accommodated is rotatably installed inside a tub in which wash water is stored, and the drum is rotated by the motor to wash / dry the laundry.

Meanwhile, an outer rotor type BLDC motor is used as the motor in the drum washing machine. Such a BLDC motor is driven by abbreviated operation in order to enable relatively high speed rotation relative to the output.

Generally, when the motor reaches the rated speed, the amount of current that can be input to the motor decreases due to the back electromotive force, so that even if a current is applied, the rotational speed of the motor no longer increases. In order to solve such a problem, when the motor reaches the rated speed, the abbreviated operation is performed in the dq axis coordinate system used in the vector control method to calculate the amount of the current input to the d axis parallel to the magnetic flux direction of the permanent magnet Thereby weakening the magnetic flux of the permanent magnet. When the motor is driven by the abbreviated operation, the operation efficiency of the motor is lowered, but the motor can be operated at a speed higher than the rated speed.

However, such abbreviated operation of the motor according to the related art has a disadvantage that it does not sufficiently reflect the characteristics of the washing machine due to the stroke. More specifically, in the case of the drying stroke of the washing machine, the load is substantially reduced by drying the laundry. However, the conventional abbreviated operation does not reflect such a decrease in the load, so that the efficiency of the motor is lowered, and noise and vibration generated when the motor is driven are increased.

It is an object of the present invention to provide a motor configured to be driven in response to a decrease in load due to a drying stroke, a washing machine including the same, and a control method thereof will be.

According to an aspect of the present invention, there is provided a stator comprising: a stator including a plurality of wound coils; A rotor including a plurality of magnets for generating an electromagnetic interaction with the coil; A speed sensor for sensing a current speed of the rotor during a drying stroke; And comparing the current speed and the command speed of the rotor sensed by the speed sensor and comparing the current speed and the command speed of the rotor detected by the speed sensor with a d axis parallel to the magnetic flux direction of the magnet so that the current speed of the rotor follows the command speed, a speed controller for outputting command currents Id * and Iq * coordinate-converted to a current component on a dq synchronous coordinate defined by the q-axis; A current controller for outputting command voltages Vd * and Vq * based on Id * and Iq * output from the speed controller; An inverter for applying power to the coil based on Vd * and Vq * output from the current controller; .

According to another embodiment of the present invention, the present invention provides a cabinet comprising: a cabinet; A tub disposed inside the cabinet; A drum rotatably installed in the tub and containing a laundry therein; The motor according to any one of claims 1 to 3, which provides a driving force for rotation of the drum. .

According to another embodiment of the present invention, there is provided a washing machine comprising: (a) a control unit of a washing machine receiving an operation signal for starting a drying cycle; (b) initializing the rotor in accordance with the operation signal received by the controller; (c) detecting, by the speed sensor, a rotational speed of the rotor; (d) The speed controller compares the current speed of the rotor sensed by the speed sensor with the command speed so that the d-axis parallel to the magnetic flux direction of the magnet so that the current speed of the rotor follows the command speed, Outputting coordinate-converted command currents Id * and Iq * with a current component on a dq synchronous coordinate defined as a q-axis orthogonal to the magnetic flux direction of the magnet; (e) the current controller outputs command voltages Vd * and Vq * based on Id * and Iq * output from the speed controller; (f) powering the coils of the stator based on Vd * and Vq * output from the current controller; .

INDUSTRIAL APPLICABILITY According to the motor, the washing machine including the same, and the control method therefor according to the present invention, there is an advantage that the driving of the motor can be controlled in accordance with the variation of the load during the drying stroke.

Hereinafter, embodiments of a motor, a washing machine including the same, and a control method thereof according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a sectional view showing an embodiment of a washing machine according to the present invention.

Referring to Fig. 1, the cabinet 1 forms an outer appearance of the drum type washing machine. The cabinet 1 may be formed in a hexahedron shape in which a part of a front surface thereof is opened.

Inside the cabinet 1, a tub 3 is provided. The washing water is stored in the tub 3. The tub 3 may be formed in a cylindrical shape having a generally open front surface. The tub 3 is provided with a washing and drinking inlet 4 for the inflow of washing water and a washing water outlet 5 for discharging the washing water.

A drum 7 is installed in the tub 3. The drum (7) is rotatably installed inside the tub (3). The laundry 7 is accommodated in the drum 7. The laundry 7 is washed by the friction between the drum 7 and the laundry cloth or the laundry cloth by the rotation of the drum 7. The drum 7 may also be formed in a cylindrical shape having a front surface corresponding to the tub 3.

The door 9 selectively opens and closes the opened front face of the cabinet 1, the tub 3, and the drum 7. The door (9) can be installed on one side of the cabinet (1) so as to be rotatable about one end thereof.

A damper 11 and a spring 13 are provided between the cabinet 1 and the tub 3 to absorb vibrations generated during the rotation of the drum 7. The damper 11 is positioned between the bottom surface of the cabinet 1 and the bottom surface of the tub 3 and the spring 13 is positioned between the top surface of the cabinet 1 and the top surface of the tub 3 do.

A motor 20 is provided on the rear surface of the tub 3. The motor 20 serves to provide a driving force for rotation of the drum 7. The motor (20) includes a stator (21) and a rotor (23). More specifically, the stator 21 is provided with a plurality of winded coils. The rotor (23) is provided with a plurality of magnets for generating an electromagnetic interaction with the coil. The rotor (23) is provided with a rotating shaft (25) for substantially providing a rotational force to the drum (7). That is, the rotor 23 is rotated by the electromagnetic interaction between the coil and the magnet, and the rotational force of the rotor 23 is transmitted to the drum 7 through the rotating shaft 25.

On the other hand, the motor 20 is provided with a hall sensor 27. The Hall sensor 27 senses the position of the rotor 23. Normally, two Hall sensors 27 are provided on the stator 21. [ The hall sensor 27 generates an ON / OFF signal by the rotation of the rotor 23. [ For example, when the rotor 23 rotates 360 degrees, the hall sensor 27 generates four on / off signals. The position of the rotor 23 is estimated based on the on / off signal generated by the hall sensor 27, thereby controlling the motor 20.

Hereinafter, the operation of the washing machine according to the embodiment of the present invention will be described.

First, the user opens the door (9) and inserts the laundry into the drum (7). Then, the user operates the control panel (not shown) to select the washing cycle of the washing machine. When the washing cycle is started, the motor 20 is rotated, and the amount of the washing cloth is detected by the load detected by the motor 20. And a stroke of the washing machine is performed so as to match the detected laundry amount.

More specifically, when the washing cycle is started, the washing water flows into the tub 3 through the washing and drinking inlet 4 and is stored. When an appropriate amount of wash water is introduced into the tub 3 and stored therein, the motor 20 is rotated to rotate the drum 7. At this time, the drum 7 rotates in a direction opposite to the forward direction, thereby preventing the laundry from clogging and increasing the washing efficiency.

When it is determined that the washing of the laundry is completed by a predetermined time, the washing water stored in the tub 3 is drained through the washing water outlet 5. Thus, the washing cycle is terminated and the rinsing cycle is started. The rinsing cycle is similar to the above-described washing cycle, and the drum 7 is rotated alternately in the forward and reverse directions to rinse the laundry.

When the rinsing cycle is completed, a dewatering and drying cycle for removing water from the laundry is performed. In the dehydrating step, the drum 7 is rotated at a high speed to remove water from the laundry. When the predetermined time has elapsed, the dehydration process is terminated. When the rolling process is completed, when the drying cycle is started and the laundry is dried, washing of the laundry by the washing machine is completed. In the drying process, high temperature air is usually supplied to the inside of the drum 7 to dry the laundry.

On the other hand, in the case of the above-mentioned drying process, the laundry is dried, so that the load acting on the drum 7 substantially decreases over time. Therefore, when the motor 20 is controlled without considering the variation of the load in the drying stroke, the generation of vibration and noise due to the driving of the motor 20 increases. Therefore, in the present embodiment, The motor 20 is operated in the abbreviated mode using the vector driving method in consideration of the variation of the load in the mode.

In the vector control method, the vector control method is a kind of power supply control method for controlling the application of the coil current. More specifically, a d-axis coordinate defined by a d-axis parallel to the magnetic flux direction of the magnet and a q-axis perpendicular to the magnet direction of the magnet is set, and current is accurately applied to the d-axis and the q-axis. In the abbreviated operation, the abbreviated operation weakens the magnetic flux of the magnet so that the command speed of the motor (20), more specifically, the command speed of the rotor (23) (23), the current amount of the current input to the d-axis parallel to the direction of the magnetic flux of the magnet in the dq-axis coordinate system is increased and output so that the current speed of the rotor (23) Follow the speed.

Next, a motor control apparatus according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

2 is a block diagram showing a control device for controlling a motor in an embodiment of the present invention.

2, the control device for controlling the motor 20 includes a motor control unit 30, a PWM computing unit 40, an inverter 50, and a current sensing unit 60.

The motor control unit 30 controls the power supplied to the motor 20. More specifically, the motor control unit 30 includes a speed / position detector 31, a speed controller 33, a current controller 35, and a coordinate conversion unit 37. The speed / position detector 31 detects the rotational speed and the rotational position of the motor 20, that is, the rotational speed and the rotational position of the rotor 23 (see FIG. 1). At this time, the speed / position detector 31 detects the rotational speed and position of the rotor 23 by virtue of the position of the rotor 23 sensed by the hall sensor 27 (see FIG. 1) can do. The speed controller 33 compares the current speed ω of the rotor 23 detected by the speed / position detector 31 with the command speed ω * so that the current speed ω follows the command speed ω * , The d-axis command current Id * and the q-axis command (Iq) are adjusted by adjusting the current components Id and Iq on the dq axis rotation coordinate system defined by the d axis parallel to the magnetic flux direction of the permanent magnet and the q axis perpendicular to the magnetic flux direction of the permanent magnet, Thereby generating a current Iq *, respectively. Based on the command current Id * and the command current Iq * output from the speed controller 33, the current controller 35 performs PID control on the current Id and the current Iq to calculate the d-axis command voltage Vd * and the q-axis command Voltage Vq *, respectively. The coordinate conversion unit 37 converts the rotation coordinate system of d-q axis and the rotation coordinate system of uvw.

The PWM calculator 40 receives a signal of the uvw stationary coordinate system output from the motor controller 30 and generates a PWM signal. The inverter 50 receives the PWM signal from the PWM calculator 40, and directly controls the power input to the motor 20. Also, the current sensing unit 60 senses the d-axis current Id and the q-axis current Iq as current currents output from the inverter 50.

First, the speed / position detector 31 continuously estimates and detects the current speed? Of the rotor 23. The current speed? Of the rotor 23 detected by the speed / position detector 31 is input to the speed controller 33. [ The speed controller 33 performs PID control of the current speed of the rotor 23 and the command speed ω * of the rotor to output the d-axis command current Id * and the q-axis command current Iq * of the d-q rotational coordinate system.

At this time, the speed controller 33 adjusts the output values of the command currents Id * and Iq * in accordance with the abrupt speed operation. More specifically, in the abbreviated operation, the speed controller 33 outputs command currents Id * and Iq *. Therefore, the abbreviated operation in which the magnetic flux of the magnet is weakened by the command current Iq * in the d-axis direction outputted from the speed controller 33 is performed. The speed controller 33 outputs only the command current Iq * in the case of normal operation.

Meanwhile, the command currents Id * and Iq * output from the speed controller 33 are input to the current controller 35. The current controller 35 performs PID control by comparing the command currents Id * and Iq * with the currents Id and Iq of the inverter 50 sensed by the current sensing unit 60 to calculate a command voltage Vd * and Vq *.

The command voltages Vd * and Vq * output from the current controller 35 are converted into command voltages on the uvw stop coordinate system by the coordinate converter 37 and input to the PWM operator 40. [ The PWM calculator 40 generates a PWM signal corresponding to the input command voltages Vd * and Vq * and inputs the PWM signal to the inverter 50. The inverter 50 drives the motor 20 by turning on / off the six transistors according to the input PWM signal.

Hereinafter, a method of controlling a washing machine according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

3 is a control flowchart showing a control method of a washing machine according to an embodiment of the present invention.

3, first, the speed / position detector 31 detects the current speed of the rotor 23 (S11). The speed / position detector 31 detects the current speed of the rotor 23 Detection will be accomplished by sensing the position of the rotor 23 by the hall sensor 27.

(S13). If it is determined in step S13 that the washing machine is in the drying cycle, the command speed of the rotor 23 is set to be the same as that of the rotor 23 It is determined whether or not it is faster than the rated speed (S15)

If it is determined in step S15 that the command speed is higher than the rated speed, the motor 20 is operated in abbreviated mode (S17). If it is determined in step S13 that the stroke of the washing machine is not the drying stroke And if it is determined in S15 that the command speed is not faster than the rated speed, the motor 20 is operated normally (S19)

If it is determined in S17 or S19 that the operation mode of the motor 20 is selected as the abrupt speed operation or the normal operation, the speed controller 33 compares the measured current speed with the command speed, * And Iq * or Iq * (S21). More specifically, when the operation mode of the motor 20 is selected as abbreviated operation, the speed controller 33 outputs Id * and Iq *. When the operation mode of the motor 20 is selected as the normal operation, the speed controller 33 outputs only Iq *.

The command currents Id * and Iq * or Iq * generated in step S21 are input to the current controller 35. The current controller 35 controls the inverter 50 sensed by the current sensing unit 60, And outputs the command voltages Vd * and Vq * on the current dq rotating coordinate system (S23).

In step S23, the command voltages Vd * and Vq * output from the current controller 35 are converted to command voltages on the uvw stop coordinate system via the coordinate converter 37 and input to the PWM calculator 40 The PWM calculator 40 generates a PWM signal corresponding to the command voltage and inputs the PWM signal to the inverter 50. In step S25, the inverter 50 drives the motor 20 in accordance with the PWM signal received in step S25. (S27)

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the appended claims and their equivalents. .

According to the motor, the washing machine including the same, and the control method of the present invention configured as described above, the motor is abruptly controlled in accordance with the variation of the load in the drying stroke, and the rotation speed thereof is changed. Therefore, according to the present invention, it is possible to minimize the occurrence of vibration or noise during operation of the motor in accordance with the decrease in the load during the drying stroke.

1 is a sectional view showing an embodiment of a washing machine according to the present invention;

2 is a block diagram showing a control device for controlling a motor in an embodiment of the present invention.

3 is a control flowchart showing a control method of a washing machine according to an embodiment of the present invention.

Claims (6)

A stator comprising a plurality of wound coils; A rotor including a plurality of magnets for generating an electromagnetic interaction with the coil; A speed sensor for sensing a current speed of the rotor during a drying stroke; And comparing the current speed and the command speed of the rotor sensed by the speed sensor and comparing the current speed and the command speed of the rotor detected by the speed sensor with a d axis parallel to the magnetic flux direction of the magnet so that the current speed of the rotor follows the command speed, a speed controller for outputting command currents Id * and Iq * coordinate-converted to a current component on a dq synchronous coordinate defined by the q-axis; A current controller for outputting command voltages Vd * and Vq * based on Id * and Iq * output from the speed controller; An inverter for applying power to the coil based on Vd * and Vq * output from the current controller; / RTI > Wherein the speed controller comprises: And outputs Id * and Iq * when the command speed of the rotor is faster than the rated speed of the rotor, And outputs only Iq * when the command speed of the rotor is equal to the rated speed of the rotor or slower than the rated speed of the rotor. The method according to claim 1, Wherein the speed sensor is at least two hall sensors provided in the stator. delete cabinet; A tub disposed inside the cabinet; A drum rotatably installed in the tub and containing a laundry therein; And The motor according to any one of claims 1 to 3, which provides a driving force for rotation of the drum. . (a) a control section of a washing machine receives an operation signal for starting a drying cycle; (b) initializing the rotor in accordance with the operation signal received by the controller; (c) detecting, by the speed sensor, a rotational speed of the rotor; (d) The speed controller compares the current speed of the rotor sensed by the speed sensor with the command speed so that the d-axis parallel to the magnetic flux direction of the magnet so that the current speed of the rotor follows the command speed, Outputs command currents Id * and Iq * coordinate-converted to current components on a dq synchronous coordinate defined by a q-axis orthogonal to the magnetic flux direction of the magnet, And outputs Id * and Iq * when the command speed of the rotor is faster than the rated speed of the rotor, Outputting only Iq * when the command speed of the rotor is equal to the rated speed of the rotor or slower than the rated speed of the rotor; (e) the current controller outputs command voltages Vd * and Vq * based on Id * and Iq * output from the speed controller; (f) powering the coils of the stator based on Vd * and Vq * output from the current controller; And a controller for controlling the washing machine. delete

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