KR20100105197A - Washing machine - Google Patents

Abstract

PURPOSE: A washing machine is provided to enable the circuit in a driver to be protected by decreasing the speed of a motor if the overload of the motor is detected. CONSTITUTION: A washing machine is composed of a motor, an inverter, a DC terminal voltage detector, and a controller. The motor supplies the torque to a tub. The inverter comprises a plurality of switching elements. The inverter converts the given DC voltage into the AC voltage of a given frequency according to the switching operation to drive the motor. The DC terminal voltage detector momentarily detects the DC voltage. The controller compares the initial value of the DC terminal voltage with the instantaneous value of the DC voltage. The controller controls the motor to lower the speed if the difference between the initial value and the instantaneous value is above a fixed value.

Description

Laundry processing machine {Washing machine}

The present invention relates to a laundry treatment apparatus, and more particularly, to a laundry treatment apparatus that can simply and accurately detect the overload of the motor to protect the motor.

In general, laundry treatment equipment uses chemical reaction between water and detergent and physical action such as friction between water and laundry to separate contaminants on clothes, bedding, etc. (hereinafter referred to as 'laundry'). Say the device. In addition, the wet laundry may be dehydrated and dried, or heated steam may be sprayed onto the laundry. In this way, the laundry treating apparatus is collectively referred to as various apparatuses for applying a physical and chemical effect to the laundry to process the laundry.

On the other hand, the laundry treatment machine is classified into an agitator type, a drum type and a pulsator type according to its structure and washing method.

Such a laundry treatment device, which normally washes laundry while sequentially performing a washing stroke, a rinsing stroke, and a dehydrating stroke, may perform only a predetermined stroke among the above-described strokes according to a user's selection, and according to the type of laundry. Washing is done in a suitable way.

On the other hand, the laundry treatment machine uses a motor to transmit the rotational force to the washing tank. Such a motor may be overloaded or restrained according to the amount of laundry in the washing tank, and in this case, the circuit elements in the driving device for driving the motor may be overwhelmed, resulting in an increase in temperature of the circuit elements or burnout of the circuit elements. The probability is high. This phenomenon is particularly aggravated in light of the current trend of increasing the size of the washing tank.

An object of the present invention is to provide a laundry treatment device that can protect the motor by simply and accurately detecting the overload of the motor.

Laundry processing apparatus according to the present invention for achieving the above object is provided with a motor for supplying rotational force to the washing tank, and a plurality of switching elements, by converting a predetermined DC power to an AC power of a predetermined frequency in accordance with the switching operation Compare the inverter driving the motor, the dc stage voltage sensing unit that instantaneously detects the DC power supply, the initial value of the dc stage voltage and the instantaneous value of the dc voltage, and if the difference is more than a predetermined value, reduce the speed of the motor. It includes a control unit for controlling.

According to the present invention, the dc terminal voltage in the motor driving apparatus is instantaneously sensed, so that the sudden change of the dc terminal voltage can be easily judged by the overload or restraint of the motor. In addition, when it is determined that the motor is overloaded or restrained, the circuit element in the driving apparatus can be protected by reducing the speed of the motor.

Hereinafter, with reference to the drawings will be described the present invention in more detail.

1 is a perspective view showing a laundry treatment apparatus according to an embodiment of the present invention, Figure 2 is a side view of the laundry treatment apparatus shown in FIG.

Referring to the drawings, the laundry treatment apparatus 100, the cabinet 110 forming the appearance of the laundry treatment apparatus 100, and the washing tank 120 is disposed inside the cabinet 110 and the laundry is accommodated therein And, the control unit 140 for controlling the overall operation of the laundry processing apparatus 100, and a driving device 150 for supplying a rotational force into the washing tank 120 to rotate the laundry in the washing tank 120.

In addition, the laundry treatment apparatus 100 includes a door 135 rotatably mounted in the cabinet 110 and a detergent box 179 mounted in and out of the cabinet 110 so that laundry can be loaded into and out of the washing tub 120. ), A water supply valve 183 connected to an external water source to regulate a water supply flow path into which the wash water flows, and a drain valve 186 to intercept a drain flow path for discharging the wash water in the washing tank 120 to the outside. .

Some of the washing water introduced from the water supply passage is introduced into the detergent box 179 and mixed with the detergent, and then supplied to the washing tank 120. At this time, the washing water flowing into the detergent box 179 may be interrupted by the auxiliary valve 189.

The washing tub 120 includes an outer tub 128 in which washing water is contained, and an inner tub 125 rotatably disposed in the outer tub 128 to accommodate laundry therein. At this time, the inner tank 125 is formed with a plurality of through-holes (not shown) to allow the wash water to circulate between the outer tank 128 and the inner tank (125).

A pulsator 130 may be disposed at the bottom of the inner tank 125 to generate a rotational flow of fresh water. The pulsator 130 is rotated forward and backward by a motor (not shown) in the driving device 150 to supply rotational force into the washing tank 130. The driving device 150 may be controlled by the controller 140. Meanwhile, a clutch (not shown) may be further disposed between the motor (not shown) and the pulsator 130 to transmit rotational force from the motor (not shown). The driving device 150 may further include such a clutch (not shown).

On the other hand, the driving device 150 may rotate the washing tank 120. Specifically, by transmitting the rotational force to the inner tank 125 of the washing tank 12, it may be rotated forward, reverse.

An auto balance (not shown) is provided at an upper portion of the inner tank 125 of the washing tank 120. Auto balance (not shown) is to reduce the vibration caused by the eccentric amount of the laundry contained in the inner tank 125, it may be implemented as a liquid balance, ball balance and the like.

The outer tub 128 of the washing tub 120 may be suspended from the cabinet 110 by the support member 173, and a damper 176 may be provided at one end of the support member 173 to act as a buffer.

On the other hand, the control panel 115 is disposed above the cabinet 110. The control panel 115 is provided with operation keys (not shown) for operating the operation state of the laundry processing apparatus 100 and a display disposed on one side of the operation keys (not shown) to display the operation state of the laundry processing apparatus 100. Device (not shown).

The operation keys (not shown) and the display device (not shown) in the control panel 115 are electrically connected to the control unit 140, and the control unit (not shown) electrically connects each component of the laundry processing apparatus 100, and the like. To control. The operation of the controller (not shown) will be described later.

3 is an internal block diagram of the laundry treatment machine of FIG.

Referring to the drawings, the laundry treatment apparatus of FIG. 3 includes an operation key 117, a display device 118, a washing tub 120, a controller 140, a motor 210, and a position sensing unit 220. It may include.

First, the control unit 140 receives an operation signal from the operation key 117 to operate. Accordingly, main washing, rinsing, and dehydration strokes can be performed.

The controller 140 controls the motor 210 for main washing, rinsing, and dehydration stroke. Although not shown in the figure for motor control, it is possible to be controlled by an inverter (not shown). For example, when the control unit 140 outputs a PWM switching control signal to an inverter (not shown), the inverter (not shown) having a plurality of switching elements performs a high-speed switching operation, and thus, AC power having a predetermined frequency and a predetermined size. This may be supplied to the motor 210. The AC power of the predetermined frequency and the predetermined size at this time may be variously set according to main washing, rinsing, dehydration stroke, and the like. An operation of the inverter (not shown) will be described later with reference to FIG. 4 or below.

In addition, the controller 140 determines the overload or restraint of the motor 210 according to the instantaneously detected dc terminal voltage in the driving device (150 of FIG. 1) to be described later. In order to protect the circuit elements in the driving apparatus 150 of FIG. 1, the rotation speed of the motor 150 is controlled to be lowered. Detailed description thereof will be described later.

On the other hand, the controller 140 may control to display the operation state of the laundry processing apparatus 100 through the display device 118. For example, an operation state such as main washing, rinsing, and dehydration stroke can be displayed.

The motor 210 includes a stator and a rotor, and an alternating current power of each phase is applied to a coil of each stator so that the rotor rotates. The type of the motor 210 may be various forms such as a BLDC motor and a synRM motor.

The motor 210 supplies rotational force to the washing tub 120. As shown in FIG. 1, the motor 210 in the driving device 150 may rotate the pulsator 130. In addition, the washing tank 120, specifically, the inner tank 125 in the washing tank 120 may be rotated. In this way, by rotating the pulsator 130 or by rotating the inner tank 125 in the washing tank 120, thereby providing a rotational force in the washing tank 120.

The position detector 220 detects the position of the motor 210. That is, the position of the rotor of the motor 210 is sensed. The position detecting unit 220 may be various examples such as a hall sensor and an encoder. The position signal H detected through the position sensor 220 is input to the controller 140 for the control operation of the motor 210.

On the other hand, when the Hall sensor is used as the position sensing unit 220, it is also possible to detect the rotor position of each phase of the three-phase motor 210, for example, it is also possible to detect the rotor position of the two phases. The detected two-phase rotor position signals Ha and Hb are input to the controller 140. The position signal H is used herein in the sense including the two-phase rotor position signals Ha, Hb.

4 is an internal block diagram of the driving device of FIG. 1.

Referring to the drawings, the driving device 150 includes a position sensor 220, a converter 410, an inverter 420, and a dc terminal voltage detector A. In addition, the driving device 150 of FIG. 4 may further include a reactor L, a smoothing capacitor C, and the like.

The reactor L is disposed between the commercial AC power supply 405 and the converter 410 to perform power factor correction or step-up operation. In addition, the reactor L may perform a function of limiting harmonic currents due to the fast switching of the converter 410.

The converter 410 converts the commercial AC power 405 into a DC power and outputs the DC power. The commercial AC power 405 input to the converter 410 may be applied via the reactor L as shown in the drawing, but is not limited thereto. Meanwhile, although the commercial AC power supply 405 is illustrated as a single phase AC power in the drawing, it may be a three phase AC power supply.

The converter 410 includes at least one diode element, and may be implemented in various forms.

Sex is possible. For example, it can be configured in various forms, such as a bridge having four diodes. In this case, only the rectifying operation may be performed without the switching operation of the separate switching element.

In addition, the converter 410 may be configured in various forms, including at least one diode and a switching element. For example, a half bridge type converter in which two switching elements and four diodes are connected may be used. In this case, the converter 410 may perform a boost operation, a power factor improvement, and a DC power conversion by a switching operation.

The smoothing capacitor C is connected to the output terminal of the converter 410. The converted DC power output from the converter 410 is smoothed. Hereinafter, the output terminal of the converter 410 is called a dc terminal. The DC voltage smoothed at the dc stage is applied to the inverter 420.

The inverter 420 includes a plurality of inverter switching elements, converts a smoothed DC power source into a three-phase AC power source having a variable frequency and magnitude by on / off operation of the switching element, and outputs the same to the motor 210.

Inverter 420 is a pair of upper arm switching elements Sa, Sb, Sc and lower arm switching elements S'a, S'b, S'c, which are connected in series with each other, and a total of three pairs of upper and lower arms The switching elements are connected in parallel with each other (Sa & S'a, Sb & S'b, Sc & S'c). Diodes are connected in anti-parallel to each of the switching elements Sa, S'a, Sb, S'b, Sc, and S'c.

The switching elements in the inverter 420 perform on / off operations of the respective switching elements based on the inverter switching control signal Sic from the controller 140. By the on / off operation of each switching element, the pulse width of the inverter switching control signal (Sic) is variable, so that the three-phase AC power having a predetermined frequency is output to the motor 210.

On the other hand, the control unit 140 controls the switching operation of the inverter 420. The controller 140 outputs an inverter switching control signal Sic to the inverter 420 in order to control the switching operation of the inverter 420. A detailed operation of the output of the inverter switching control signal Sic in the controller 140 will be described later with reference to FIG. 5.

The controller 140 may determine whether the motor 210 operates abnormally based on the dc terminal voltage Vdc that is momentarily sensed by the dc terminal voltage detector A. FIG. For example, when the difference between the initial value and the instantaneous value of the c-stage voltage Vdc is greater than or equal to the predetermined value, it is determined that the motor 210 in the driving device 150 is abnormally operated. Accordingly, the controller 140 controls the speed of the motor 210 to decrease. Specifically, the speed of the motor 210 is lowered by lowering the pulse width of the inverter switching control signal Sic. Meanwhile, after a predetermined time, the controller 140 may increase the speed of the motor 210 to approach the target speed.

 The dc terminal voltage detection unit A may instantaneously detect a dc terminal voltage Vdc, which is both ends of the smoothing capacitor C. To this end, the dc terminal voltage sensing unit A may include a resistor or the like. The instantaneous value of the detected dc terminal voltage Vdc is input to the controller 140 to determine whether the motor 210 operates abnormally.

5 is an internal block diagram of the controller of FIG. 4.

Referring to the drawings, the controller 140 controls the speed calculator 505, the current command generator 510, the voltage command generator 520, and the switching control to output the inverter switching control signal Sic. The signal output unit 530 may be included.

The speed calculator 505 calculates the speed of the motor 210, specifically, the speed of the rotor of the motor 210, based on the position signal H detected by the position sensor 220. Here, the speed of the motor 210 may be an angular speed. The speed of the motor 210 may be calculated as the change amount of the position signal H with respect to the unit time.

The speed calculator 505 estimates the output current io flowing through the motor 210 based on the position signal H detected by the position sensor 220. For example, calculating the speed of the motor 210 based on the position signal H, the output current is derived from the relationship between the mechanical equation based on the speed of the motor 210 and the electrical equation based on the current of the motor 210. (io) can be estimated.

The current command generation unit 510 generates a d, q-axis current command value i ^* d, i ^* q through a PI controller or the like based on the estimated speed v and the speed command value v ^* . In the drawing, although the d, q-axis current command value (i ^* d, i ^* q) is generated by vector control, the present invention is not limited thereto, and the current command value I, which is a scalar value, may be output. .

The voltage command generation unit 520, based on the d, q-axis current command value (i ^* d, i ^* q) and the output current (io) estimated by the speed calculating unit 505, via the PI controller, d, Generate the q-axis voltage command value (v ^* d, v ^* q). In the drawing, although the d, q-axis voltage command value (v ^* d, v ^* q) is generated through vector control, the present invention is not limited thereto, and the voltage command value V, which is a scalar value, may be output.

Switching control signal output unit 530 is d, q-axis voltage command value (v ^* d, v ^* q), switching elements (Sa, S'a, Sb, S'b, Sc in the inverter 420 based on, The inverter switching control signal Sic is output to the inverter 420 to drive S'c.

As a result, the controller 140 controls the inverter switching control signal whose pulse width is variable based on the speed command value v ^* determined according to the steps of the washing stroke, the rinsing stroke, the dehydrating stroke, and the like and the amount of the laundry. Output (Sic).

FIG. 6 is a diagram illustrating a change in dc voltage and temperature of FIG. 4 according to a motor speed.

Referring to the drawings, FIG. 6 (a) shows that the motor 210 or the washing tub 120 is driven in a predetermined pattern. Once shown, the forward rotation of the first speed v1 and the reverse rotation of the second speed v2 are shown to be repeated several times. Here, the magnitude of the first velocity v1 and the magnitude of the second velocity may be the same but are not limited thereto.

In addition, FIG. 6 (a) may be at the time of stirring washing or inflated stroke in which forward rotation and reverse rotation are repeated.

Next, FIG. 6 (b) shows the instantaneous value of the dc terminal voltage Vdc in the driving device 150 when the motor 210 repeats the forward rotation or the reverse rotation several times as shown in FIG. 6 (a). During the initial driving, that is, when there is almost no load connected to the motor 210, the dc terminal voltage Vdc maintains the voltage of the initial value Vdc1, but when the load is largely generated in the motor 210, the dc terminal voltage Is momentarily lowered. In FIG. 6 (b), in particular, when the motor 210 repeats the forward rotation or the reverse rotation several times in a state in which there is a considerable amount of laundry in the washing tank 120, the instantaneous value of the dc terminal voltage is significantly larger than the initial value Vdc1. Shows lowering.

Next, FIG. 6 (c) shows the temperature Tm of the motor 210 and the temperature Ti of the inverter 420 when the motor 210 repeats the forward or reverse rotation several times as shown in FIG. 6 (a). The trends of changes are shown. That is, when the motor 210 repeats the forward rotation or the reverse rotation several times, the temperature Tm of the motor 210 and the temperature Ti of the inverter 420 rise considerably. As a result, the possibility of burnout of the circuit elements in the driving apparatus 150 increases.

7 is a view for explaining the motor speed in connection with an embodiment of the present invention.

Referring to the drawings, first, as shown in FIG. 7A, as shown in FIG. 6A, the motor 210 rotates forward and backward in the first speed v1 and reverse in the second speed v2 several times. It is shown to be repeated.

The controller 140 compares an initial value and an instantaneous value of the dc terminal voltage detected by the dc terminal voltage detector A, and determines that the motor 210 is overloaded or restrained when the difference is greater than or equal to a predetermined value.

In the related art, the output current sensing means between the motor 210 and the inverter 420 is used to directly determine whether the motor 210 is overloaded or restrained from the output current, but in the embodiment of the present invention, simply, dc By instantaneously detecting the dc terminal voltage from the short voltage detecting unit A, it is determined whether the motor 210 is overloaded or restrained.

When the overload or restraint of the motor 210 occurs, if the output current (or phase current) supplied to the motor 210 momentarily increases, the amount of power consumed by the motor 210 is within a certain range. The output voltage supplied to the motor 210 is inevitably reduced. Therefore, the instantaneous value of the dc terminal voltage is also rapidly lowered as shown in FIG. 6 (b). In the embodiment of the present invention, by using this principle, it is possible to infer whether or not the abnormal operation of the motor 210 by the detection of the Vdc voltage.

Therefore, the controller 140 compares the initial value Vdc1 of the dc terminal voltage with the instantaneous value of the dc voltage, and controls the motor 210 to be lowered when the difference is more than a predetermined value.

In FIG. 7B, the control operation is performed such that the forward rotation of the third speed v3 is smaller than the first speed v1 and the second speed v2 of FIG. 7A. , And the reverse rotation of the fourth speed v4 is repeated several times. By operating the motor 210 in this way, it is possible to protect the circuit elements in the driving device 150.

Meanwhile, the controller 140 may compare the initial value Vdc1 of the dc terminal voltage with the instantaneous value of the dc voltage, and may stop the motor 210 at all when the difference exceeds the lower limit.

FIG. 8 is a diagram for describing switching control signal variation in connection with an embodiment of the present invention. FIG. 8A shows the inverter switching control signal Sic1 corresponding to FIG. 7A, and FIG. 8B shows the inverter switching control signal SIC2 corresponding to FIG. 7B.

That is, the controller 140 compares the initial value and the instantaneous value of the dc terminal voltage detected by the dc terminal voltage detection unit A in a normal case, and when the difference is less than the predetermined value, the predetermined inverter switching control signal. Outputs (Sic1).

Next, the controller 140 compares the initial value and the instantaneous value of the dc terminal voltage detected from the dc terminal voltage detection unit A in a normal case, and when the difference is more than a predetermined value, the speed of the motor 210 is increased. In order to reduce, the pulse width of the inverter switching control signal Sic2 is reduced. In the drawing, the pulse width of the inverter switching control signal Sic2 of FIG. 8B is smaller than the pulse width of the inverter switching control signal Sic1 of FIG. 8A. In particular, the maximum pulse width Pm1 of the inverter switching control signal Sic2 of FIG. 8B is narrower than the maximum pulse width Pm1 of the inverter switching control signal Sic1 of FIG. 8A.

On the other hand, the controller 140 compares the initial value of the dc terminal voltage (Vdc1) and the instantaneous value of the dc voltage, and when the difference exceeds the lower limit, the inverter switching control signal is low level so as to stop the motor 210 at all. It can be to have. As a result, all switching elements Sa, S'a, Sb, S'b, Sc, and S'c in the inverter 420 are opened.

On the other hand, the laundry treatment apparatus according to the embodiment of the present invention described above, but described mainly with a vortex-type laundry treatment device having a pulsator, irrespective of this will be applicable to a stirring or drum-type laundry treatment device. That is, it will be sufficient if the washing rod, the drum, the pulsator, etc. are rotated by the driving of the motor so that the rotational force is transmitted to the washing tank.

While the above has been shown and described with respect to preferred embodiments of the present invention, the present invention is not limited to the specific embodiments described above, it is usually in the technical field to which the invention belongs without departing from the spirit of the invention claimed in the claims. Various modifications can be made by those skilled in the art, and these modifications should not be individually understood from the technical spirit or the prospect of the present invention.

1 is a perspective view showing a laundry treatment apparatus according to an embodiment of the present invention.

Figure 2 is a side view of the laundry treatment machine shown in FIG.

3 is an internal block diagram of the laundry treatment machine of FIG.

4 is an internal block diagram of the driving device of FIG. 1.

5 is an internal block diagram of the controller of FIG. 4.

FIG. 6 is a diagram illustrating a change in dc voltage and temperature of FIG. 4 according to a motor speed.

7 is a view for explaining the motor speed in connection with an embodiment of the present invention.

FIG. 8 is a diagram for describing switching control signal variation in connection with an embodiment of the present invention.

<Explanation of symbols on main parts of the drawings>

100: laundry processing apparatus 110: cabinet

120: washing tank 140: control unit

150: drive device 210: motor

220: position detection unit 410: converter

420: inverter A: dc terminal voltage detection unit

Claims (7)

A motor for supplying rotational force to the washing tank; An inverter having a plurality of switching elements and converting a predetermined DC power source into an AC power source having a predetermined frequency according to a switching operation to drive the motor; A dc terminal voltage detector configured to detect the DC power supply instantaneously; And And a controller for comparing the initial value of the dc terminal voltage with the instantaneous value of the dc voltage, and controlling the speed of the motor to be lowered when the difference is greater than or equal to a predetermined value. The method of claim 1, The control unit, Outputs a switching control signal having a variable pulse width to control a switching operation of the inverter, And the pulse width of the switching control signal is reduced if the difference is greater than or equal to a predetermined value. The method of claim 1, The control unit, And while the motor is repeatedly performing the forward rotation and the reverse rotation, when the difference is greater than or equal to a predetermined value, the laundry treating apparatus for controlling the speed of the motor. The method of claim 1, And a converter for converting commercial AC power into DC power. The method of claim 1, Laundry treatment apparatus further comprises a; position detection unit for detecting the position of the motor. The method of claim 5, The control unit, A speed calculator configured to estimate a speed based on the detected position of the motor; A current command generation unit that generates a current command value based on the estimated speed and the speed command value; A voltage command generator that generates a voltage command value based on the current command value; And And a switching control signal output unit configured to generate and output an inverter switching control signal based on the voltage command value. The method of claim 6, The speed calculator, based on the detected position of the motor, estimates the output current of the motor, And the voltage command generator generates the voltage command value based on the estimated output current and the current command value.

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