Patent Description:
Further, the present disclosure relates to a circulation pump driving apparatus capable of driving a circulation pump motor in a sensorless manner and a laundry treatment machine including the same.

Further, the present disclosure relates to a circulation pump driving apparatus capable of improving the stability of a converter and a laundry treatment machine including the same.

A circulation pump driving apparatus drives a circulation pump motor to pump water introduced into a water introduction part and discharge it into a washing tub.

When using an AC pump motor to drive a circulation pump, the motor is normally driven by a constant speed operation with an input AC voltage.

For example, when a frequency of the input AC voltage is <NUM>, the circulation pump motor rotates at <NUM> rpm, and when the frequency of the input AC voltage is <NUM>, the circulation pump motor rotates at <NUM> rpm.

Such an AC pump motor has a drawback such as an extended period of time for completion of drainage because the speed of the motor is not controlled during drainage.

In order to address the drawback, researches are being conducted to apply a DC brushless motor as the circulation pump motor.

Examples of a drain pump motor based on a DC brushless motor are disclosed in <CIT> and <CIT>.

In the prior documents, there is a drawback such as an extended period of time for completion of drainage during drainage because speed control is performed when the drain pump motor is controlled.

In addition, the prior documents disclose control of the drain pump motor, not control of the circulation pump motor, and disclose only control when the drain pump motor is controlled, not various operations of the circulation pump motor.

<CIT> relates to a washing machine having a nozzle for discharging water circulated along a circulation pipe discharged from a tub into a drum.

The present invention provides a circulation pump driving apparatus capable of improving washing power by circulation pumping during washing and a laundry treatment machine including the same.

Further, the present invention provides a circulation pump driving apparatus capable of driving a circulation pump motor in a sensorless manner and a laundry treatment machine including the same.

Further, the present invention provides a circulation pump driving apparatus capable of improving the stability of a converter and a laundry treatment machine including the same.

An embodiment of the present invention provides a circulation pump driving apparatus and a laundry treatment machine including an inverter converting a DC voltage from a converter into an alternating current (AC) voltage by a switching operation and outputting converted AC voltage to a circulation pump motor, and a controller to control the circulation pump motor to operate in at least two modes among a first mode in which one of a speed and a power of the circulation pump motor is constant, a second mode in which the one of the speed and the power of the circulation pump motor repeatedly rises and falls, and a third mode in which the one of the speed and the power of the circulation pump motor rises at a first rising slope and a second rising slope and then remains constant. Further, in the second mode, the controller is configured to increase the speed of the circulation pump motor at a third rising slope, to then increase the speed of the circulation pump motor at a fourth rising slope, to then decrease the speed of the circulation pump motor at a first falling slope, and to then repeatedly rise and fall twice at the fourth rising slope and fall at the first falling slope, respectively, and to then decrease the speed of the circulation pump motor at a second falling slope, and wherein the third rising slope is larger than the fourth rising slope.

In the circulation pump driving apparatus or the laundry treatment machine according to an embodiment of the present invention, the controller may perform control such that the fourth rising slope of the circulation pump motor and the falling slope thereof are the same as each other in the second mode.

In the circulation pump driving apparatus or the laundry treatment machine according to an embodiment of the present invention, the controller may perform control such that the fourth rising slope of the circulation pump motor in the second mode and the second rising slope thereof in the third mode are the same as each other.

In the circulation pump driving apparatus or the laundry treatment machine according to an embodiment of the present invention, the controller sets the first rising slope in the third mode to be greater than the second rising slope.

In the circulation pump driving apparatus or the laundry treatment machine according to an embodiment of the present invention, the controller may perform control such that the first to third modes are performed sequentially and repeatedly.

A circulation pump driving apparatus and a laundry treatment machine according to an embodiment of the present disclosure includes an inverter converting the DC voltage from the converter into an alternating current (AC) voltage by a switching operation and to output the converted AC voltage to the circulation pump motor, and a controller to control the circulation pump motor to operate in at least two modes among a first mode in which a speed of the circulation pump motor is constant, a second mode in which the speed of the circulation pump motor repeatedly rises and falls, and a third mode in which the speed of the circulation pump motor rises at a first rising slope and a second rising slope and then remains constant. Accordingly, it is possible to improve washing power due to circulation pumping during washing.

In the circulation pump driving apparatus or the laundry treatment machine according to an embodiment of the present disclosure, in the second mode, the controller may perform control such that a speed rising slope of the circulation pump motor and a speed falling slope thereof are the same as each other. Accordingly, it is possible to improve washing power due to circulation pumping during washing.

In the circulation pump driving apparatus or the laundry treatment machine according to an embodiment of the present disclosure, the controller may perform control such that a speed rising slope of the circulation pump motor in the second mode and a speed rising slope in the third mode are the same as each other. Accordingly, it is possible to improve washing power due to circulation pumping during washing.

In the circulation pump driving apparatus or the laundry treatment machine according to an embodiment of the present disclosure, the controller may set the first rising slope in the third mode to be greater than the second rising slope. Accordingly, it is possible to improve washing power due to circulation pumping during washing.

In the circulation pump driving apparatus or the laundry treatment machine according to an embodiment of the present disclosure, the controller may perform control such that the first to third modes are performed sequentially and repeatedly. Accordingly, it is possible to improve washing power due to circulation pumping during washing.

Furthermore, another embodiment of the present disclosure provides a circulation pump driving apparatus and a laundry treatment machine including an inverter converting a DC voltage from a converter into an alternating current (AC) voltage by a switching operation and outputting the converted AC voltage to a circulation pump motor, and a controller to control the circulation pump motor to operate in at least two modes among a first mode in which power of the circulation pump motor is constant, a second mode in which the power of the circulation pump motor repeatedly rises and falls, and a third mode in which the power of the circulation pump motor rises at a first rising slope and a second rising slope and then remains constant. Accordingly, it is possible to improve washing power due to circulation pumping during washing.

Furthermore, yet another embodiment of the present disclosure provides a laundry treatment machine including an inverter converting a DC voltage from a converter into an alternating current (AC) voltage by a switching operation and outputting the converted AC voltage to a circulation pump motor, and a controller to control speed of the circulation pump motor to be constant when the washing tub motor operates at a speed at which laundry is attached to the washing tub. Accordingly, it is possible to improve washing power due to circulation pumping during washing.

Furthermore, yet another embodiment of the present disclosure provides a laundry treatment machine including an inverter converting a DC voltage from a converter into an alternating current (AC) voltage by a switching operation and outputting the converted AC voltage to a circulation pump motor, and a controller to control speed of the circulation pump motor to repeatedly rise and fall when a washing tub motor operates at a speed at which laundry moves in a lower portion of the washing tub. Accordingly, it is possible to improve washing power due to circulation pumping during washing.

Furthermore, yet another embodiment of the present disclosure provides a laundry treatment machine including an inverter converting a DC voltage from a converter into an alternating current (AC) voltage by a switching operation and outputting the converted AC voltage to a circulation pump motor, and a controller to control speed of the circulation pump motor to rise at a first rising slope and a second rising slope and then remain constant when a washing tub motor operates at a speed at which laundry moves from a lower portion of the washing tub to a upper portion and falls from the upper portion. Accordingly, it is possible to improve washing power due to circulation pumping during washing.

Reference will now be made in detail to the preferred embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings.

As used herein, the suffixes "module" and "unit" are added or used interchangeably to facilitate preparation of this specification and are not intended to suggest distinct meanings or functions. Accordingly, the terms "module" and "unit" may be used interchangeably.

<FIG> is a perspective view illustrating a laundry treatment machine according to an embodiment of the present disclosure, and <FIG> is a side cross-sectional view illustrating the laundry treatment machine of <FIG>.

Referring to <FIG> and <FIG>, the laundry treatment machine <NUM> according to an embodiment of the present disclosure is a laundry treatment machine in a front loading type in which laundry is inserted into a washing tub through the front of the machine.

Referring to the figures, the laundry treatment machine <NUM> is a drum-type laundry treatment machine, and includes a casing <NUM> forming an outer appearance of the laundry treatment machine <NUM>, a washing tub <NUM> disposed inside the casing <NUM> and supported by the casing <NUM>, a drum <NUM> that is a washing tub disposed inside the washing tub <NUM> to wash laundry, a motor <NUM> for driving the drum <NUM>, a wash water supply apparatus (not shown) disposed outside a cabinet body <NUM> to supply wash water into the casing <NUM>, and a drainage apparatus (not shown) formed under the washing tub <NUM> to discharge the wash water to the outside.

A plurality of through holes 122A are formed in the drum <NUM> to allow the wash water to pass therethrough, and a lifter <NUM> may be disposed on an inner surface of the drum <NUM> such that laundry is lifted to a predetermined height and then falls by gravity when the drum <NUM> rotates.

The casing <NUM> includes a cabinet body <NUM>, a cabinet cover <NUM> disposed on the front of the cabinet body <NUM> and coupled to the cabinet body <NUM>, a control panel <NUM> disposed on the cabinet cover <NUM> and coupled to the cabinet body <NUM>, and a top plate <NUM> disposed on the control panel <NUM> and coupled to the cabinet body <NUM>.

The cabinet cover <NUM> includes a laundry entrance hole <NUM> formed to allow laundry to enter and exit therethrough, and a door <NUM> disposed in such a manner as to be rotatable in a horizontal direction to open or close the laundry entrance hole <NUM>.

The control panel <NUM> includes operation keys <NUM> for controlling an operation state of the laundry treatment machine <NUM> and a display <NUM> (not shown) disposed on one side of the operation keys <NUM> to display the operation state of the laundry treatment machine <NUM>.

The operation keys <NUM> and the display <NUM> in the control panel <NUM> are electrically connected to a controller (not shown), and the controller (not shown) electrically controls each component of the laundry treatment machine <NUM>. A description about an operation of the controller (not shown) is omitted because the operation of the controller <NUM> illustrated in <FIG> can be referred to.

Meanwhile, an automatic balancer (not shown) may be provided in the drum <NUM>. The automatic balancer (not shown), which is provided to reduce vibrations generated based on an eccentric amount of laundry accommodated in the drum <NUM>, may be implemented as a liquid balancer, a ball balancer, or the like.

Meanwhile, the wash water is drained from the washing tub <NUM> through a drain channel <NUM>. A drain valve <NUM> for regulating the drain channel <NUM> and a drain pump <NUM> for pumping the wash water may be provided.

Moreover, a circulation pump <NUM> for pumping wash water may be provided on an end of the drain channel <NUM>. The wash water pumped by the circulation pump <NUM> may be introduced into a washing tub <NUM> through a circulation channel <NUM>.

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

Referring to <FIG>, in the laundry treatment machine <NUM>, the driving unit <NUM> is controlled by the main controller <NUM>, and the driving unit <NUM> drives the motor <NUM>. Thereby, the washing tub <NUM> is rotated by the motor <NUM>.

Meanwhile, the laundry treatment machine <NUM> may include a motor <NUM> for driving the drain pump <NUM> and a drain pump driving apparatus <NUM> for driving the motor <NUM>. The drain pump driving apparatus <NUM> may be controlled by the main controller <NUM>.

Meanwhile, the laundry treatment machine <NUM> may include a circulation pump motor <NUM> for driving the circulation pump <NUM> and a circulation pump driving apparatus <NUM> for driving the circulation pump motor <NUM>. The circulation pump driving apparatus <NUM> may be controlled by the main controller <NUM>.

In this specification, the circulation pump driving apparatus <NUM> may be referred to as a circulation pump driving unit.

The main controller <NUM> operates by receiving an operation signal from an operation key <NUM>. Accordingly, washing, rinsing, and dewatering processes may be performed.

In addition, the main controller <NUM> may control the display <NUM> to display a washing course, a washing time, a dewatering time, a rinsing time, a current operation state, or the like.

Meanwhile, the main controller <NUM> controls the driving unit <NUM> to operate the motor <NUM>. For example, the main controller <NUM> may control the driving unit <NUM> to rotate the motor <NUM>, based on a current detector <NUM> for detecting an output current flowing in the motor <NUM> and a position sensor <NUM> for sensing a position of the motor <NUM>. While it is illustrated in the drawing that the detected current and the sensed position signal are input to the driving unit <NUM>, embodiments of the present disclosure are not limited thereto. The detected current and the sensed position signal may be input to the main controller <NUM> or to both the main controller <NUM> and the driving unit <NUM>.

The driving unit <NUM>, which serves to drive the motor <NUM>, may include an inverter (not shown) and an inverter controller (not shown). In addition, the driving unit <NUM> may further include a converter or the like for supplying a direct current (DC) voltage input to the inverter (not shown).

For example, when the inverter controller (not shown) outputs a switching control signal in a pulse width modulation (PWM) scheme to the inverter (not shown), the inverter (not shown) may perform a high-speed switching operation to supply an alternating current (AC) voltage at a predetermined frequency to the motor <NUM>.

The main controller <NUM> may sense a laundry amount based on a current io detected by the current detector <NUM> or a position signal H sensed by the position sensor <NUM>. For example, while the washing tub <NUM> rotates, the laundry amount may be sensed based on the current value io of the motor <NUM>.

The main controller <NUM> may sense an amount of eccentricity of the washing tub <NUM>, that is, an unbalance (UB) of the washing tub <NUM>. The sensing of the amount of eccentricity may be performed based on a ripple component of the current io detected by the current detector <NUM> or an amount of change in rotational speed of the washing tub <NUM>.

Meanwhile, a water level sensor <NUM> may measure a water level in the washing tub <NUM>.

For example, a water level frequency at a zero water level with no water in the washing tub <NUM> may be <NUM>, and a frequency at a full water level at which water reaches an allowable water level in the washing tub <NUM> may be <NUM>.

That is, the frequency of the water level detected by the water level sensor <NUM> may be inversely proportional to the water level in the washing tub.

The water level Shg in the washing tub output from the water level sensor <NUM> may be a water level frequency or a water level that is inversely proportional to the water level frequency.

Meanwhile, the main controller <NUM> may determine whether the washing tub <NUM> is at a full water level, a zero water level, or a reset water level, based on the water level Shg in the washing tub detected by the water level sensor <NUM>.

<FIG> illustrates an example of an internal block diagram of the circulation pump driving apparatus of <FIG>, and <FIG> illustrates an example of an internal circuit diagram of the circulation pump driving apparatus of <FIG>.

Referring to <FIG> and <FIG>, the circulation pump driving apparatus <NUM> according to an embodiment of the present disclosure serves to drive the circulation pump motor <NUM> in a sensorless manner, and may include an inverter <NUM>, an inverter controller <NUM>, and a main controller <NUM>.

The main controller <NUM> and the inverter controller <NUM> may correspond to a controller and a second controller described in this specification, respectively.

The circulation pump driving apparatus <NUM> according to an embodiment of the present disclosure may include a converter <NUM>, a DC terminal voltage detector B, a DC terminal capacitor C, and an output current detector E. In addition, the circulation pump driving apparatus <NUM> may further include an input current detector A and a reactor L.

Hereinafter, an operation of each constituent unit in the circulation pump driving apparatus <NUM> of <FIG> and <FIG> will be described.

The reactor L is disposed between a commercial AC voltage source <NUM> (Vs) and the converter <NUM>, and performs a power factor correction operation or a boost operation. In addition, the reactor L may also function to limit a harmonic current resulting from high-speed switching of the converter <NUM>.

The input current detector A may detect an input current is input from the commercial AC voltage source <NUM>. To this end, a current transformer (CT), a shunt resistor, or the like may be used as the input current detector A. The detected input current is is may be input to the inverter controller <NUM> or the main controller <NUM> as a discrete signal in the form of a pulse. In the drawing, it is illustrated that the detected output current idc is input to the main controller <NUM>.

The converter <NUM> converts the commercial AC voltage source <NUM> having passed through the reactor L into a DC voltage and outputs the DC voltage. Although the commercial AC voltage source <NUM> is shown as a single-phase AC voltage source in the drawing, it may be a <NUM>-phase AC voltage source. The converter <NUM> has an internal structure that varies depending on the type of commercial AC voltage source <NUM>.

Meanwhile, the converter <NUM> may be configured with diodes or the like without a switching device, and may perform a rectification operation without a separate switching operation.

For example, in case of the single-phase AC voltage source, four diodes may be used in the form of a bridge. In case of the <NUM>-phase AC voltage source, six diodes may be used in the form of a bridge.

As the converter <NUM>, for example, a half-bridge type converter having two switching devices and four diodes connected to each other may be used. In case of the <NUM>-phase AC voltage source, six switching devices and six diodes may be used for the converter.

When the converter <NUM> has a switching device, a boost operation, a power factor correction, and a DC voltage conversion may be performed by the switching operation of the switching device.

Meanwhile, the converter <NUM> may include a switched mode power supply (SMPS) having a switching device and a transformer.

The converter <NUM> may convert a level of an input DC voltage and output the converted DC voltage.

The DC terminal capacitor C smooths the input voltage and stores the smoothed voltage. In the drawing, one element is exemplified as the DC terminal capacitor C, but a plurality of elements may be provided to secure element stability.

While it is illustrated in the drawing that the DC terminal capacitor C is connected to an output terminal of the converter <NUM>, embodiments of the present disclosure are not limited thereto. The DC voltage may be input directly to the DC terminal capacitor C.

For example, a DC voltage from a solar cell may be input directly to the DC terminal capacitor C or may be DC-to-DC converted and input to the DC terminal capacitor C. Hereinafter, what is illustrated in <FIG> will be mainly described.

Both ends of the DC terminal capacitor C may be referred to as DC terminals or DC link terminals because the DC voltage is stored therein.

The DC terminal voltage detector B may detect a voltage Vdc between the DC terminals, which are both ends of the DC terminal capacitor C. To this end, the DC terminal voltage detector B may include a resistance element and an amplifier. The detected DC terminal voltage Vdc may be input to the inverter controller <NUM> or the main controller <NUM> as a discrete signal in the form of a pulse. In <FIG>, it is illustrated that the detected output current idc is input to the main controller <NUM>.

The inverter <NUM> may include a plurality of inverter switching devices. The inverter <NUM> may convert the smoothed DC voltage Vdc into an AC voltage by an on/off operation of the switching device, and output the AC voltage to the synchronous motor <NUM>.

For example, when the synchronous motor <NUM> is in a <NUM>-phase type, the inverter <NUM> may convert the DC voltage Vdc into <NUM>-phase AC voltages va, vb and vc and output the <NUM>-phase AC voltages to the three-phase synchronous motor <NUM> as shown in <FIG>.

As another example, when the synchronous motor <NUM> is in a single-phase type, the inverter <NUM> may convert the DC voltage Vdc into a single-phase AC voltage and output the single-phase AC voltage to a single-phase synchronous motor <NUM>.

The inverter <NUM> includes upper switching devices Sa, Sb and Sc and lower switching devices S'a, S'b and S'c. Each of the upper switching devices Sa, Sb and Sc that are connected to one another in series and a respective one of the lower switching devices S'a, S'b and S'c that are connected to one another in series form a pair. Three pairs of upper and lower switching devices Sa and S'a, Sb and S'b, and Sc and S'c are connected to each other in parallel. Each of the switching devices Sa, S'a, Sb, S'b, Sc and S'c is connected with a diode in anti-parallel.

Each of the switching devices in the inverter <NUM> is turned on/off based on an inverter switching control signal Sic from the inverter controller <NUM>. Thereby, an AC voltage having a predetermined frequency is output to the synchronous motor <NUM>.

The inverter controller <NUM> may output the switching control signal Sic to the inverter <NUM>.

In particular, the inverter controller <NUM> may output the switching control signal Sic to the inverter <NUM>, based on a voltage command value Sn input from the main controller <NUM>.

The inverter controller <NUM> may output voltage information Sm of the circulation pump motor <NUM> to the main controller <NUM>, based on the voltage command value Sn or the switching control signal Sic.

The inverter <NUM> and the inverter controller <NUM> may be configured as one inverter module IM, as shown in <FIG> or <FIG>.

The main controller <NUM> may control the switching operation of the inverter <NUM> in a sensorless manner.

To this end, the main controller <NUM> may receive an output current io detected by the output current detector E and a DC terminal voltage Vdc detected by the DC terminal voltage detector B.

The main controller <NUM> may calculate a power based on the output current io and the DC terminal voltage Vdc, and output a voltage command value Sn based on the calculated power.

In particular, the main controller <NUM> may perform power control to stably operate the circulation pump motor <NUM> and output a voltage command value Sn based on the power control. Accordingly, the inverter controller <NUM> may output a switching control signal Sic corresponding to the voltage command value Sn based on the power control.

The output current detector E may detect an output current io flowing in the <NUM>-phase circulation pump motor <NUM>.

The output current E may be disposed between the <NUM>-phase circulation pump motor <NUM> and the inverter <NUM> to detect an output current io flowing in the motor. In the drawing, it is illustrated that the a-phase current is detected, out of the phase current ia, ib, and ic which is the output current io flowing in the circulation pump motor <NUM>.

Meanwhile, as opposed to the drawing, the output current detector E may be disposed between the DC terminal capacitor C and the inverter <NUM> and sequentially detect the output current flowing in the motor. In this case, one shunt resistance element Rs may be used, and the phase current ia, ib, and ic flowing in the circulation pump motor <NUM> may be detected in a time-division manner.

The detected output current io may be input to the inverter controller <NUM> or the main controller <NUM> as a discrete signal in the form of a pulse. In the drawing, it is illustrated that the detected output current io is input to the main controller <NUM>.

The <NUM>-phase circulation pump motor <NUM> includes a stator and a rotor. The rotor rotates when the AC voltage at a predetermined frequency for each phase is applied to a coil of the stator for each phase (phase a, b or c).

Such a circulation pump motor <NUM> may include a brushless DC (BLDC) motor.

The circulation pump motor <NUM> may include, for example, a surface-mounted permanent-magnet synchronous motor (SMPMSM), an interior permanent magnet synchronous motor (IPMSM), and a synchronous reluctance motor (SynRM). The SMPMSM and the IPMSM are permanent magnet synchronous motors (PMSM) employing permanent magnets, while the SynRM has no permanent magnet.

<FIG> is an internal block diagram of the main controller of <FIG>.

Referring to <FIG>, the main controller <NUM> may include a speed calculator <NUM>, a power calculator <NUM>, a power controller <NUM>, and a speed controller <NUM>.

The speed calculator <NUM> may calculate a speed of the circulation pump motor <NUM>, based on the voltage information Sm of the circulation pump motor <NUM> received from the inverter controller <NUM>.

Specifically, the speed calculator <NUM> may calculate a zero crossing for the voltage information Sm of the circulation pump motor <NUM> received from the inverter controller <NUM>, and calculate a speed of the circulation pump motor <NUM> based on the zero crossing.

The power calculator <NUM> may calculate a power P supplied to the circulation pump motor <NUM>, based on the output current idc detected by the output current detector E and the DC terminal voltage Vdc detected by the DC terminal voltage detector B.

The power controller <NUM> may generate a speed command value ω*r based on the power P calculated by the power calculator <NUM> and a preset power command value P*r.

For example, the power controller <NUM> may generate the speed command value ω*r, while a PI controller <NUM> performs PI control, based on a difference between the calculated power P and the power command value P*r.

Meanwhile, the speed controller <NUM> may generate a voltage command value Sn, based on the speed calculated by the speed calculator <NUM> and the speed command value ω*r generated by the power controller <NUM>.

Specifically, the speed controller <NUM> may generate the voltage command value Sn, while a PI controller <NUM> performs PI control, based on a difference between the calculated speed and the speed command value ω*r.

The generated voltage command value Sn may be output to the inverter controller <NUM>.

The inverter controller <NUM> may receive the voltage command value Sn from the main controller <NUM>, and generate and output an inverter switching control signal Sic in the PWM scheme.

The output inverter switching control signal Sic may be converted into a gate drive signal in a gate driving unit (not shown), and the converted gate drive signal may be input to a gate of each switching device in the inverter <NUM>. Thus, each of the switching devices Sa, S'a, Sb, S'b, Sc and S'c in the inverter <NUM> performs a switching operation. Accordingly, the power control can be performed stably.

Meanwhile, the main controller <NUM> according to an embodiment of the present disclosure may control the power supplied to the circulation pump motor <NUM>, during circulation pumping, to be constant, without decreasing over time. Accordingly, a drainage time can be shortened.

The main controller <NUM> according to an embodiment of the present disclosure may control the circulation pump motor <NUM> such that the power control is performed when the drainage is started and the power control is terminated when a residual water level is reached. Accordingly, the drainage operation can be efficiently performed.

The main controller <NUM> according to an embodiment of the present disclosure may control the voltage command value Sn and a duty of the switching control signal Sic to be greater as the output current io is at a smaller level. Accordingly, the circulation pump motor <NUM> can be driven with a constant power.

The circulation pump motor <NUM> according to an embodiment of the present disclosure may be implemented as a brushless DC motor <NUM>. Accordingly, the power control, rather than constant-speed control, can be implemented in a simple manner.

Meanwhile, during the circulation pumping, the main controller <NUM> according to an embodiment of the present disclosure may control the speed of the circulation pump motor <NUM> to be increased when the power supplied to the circulation pump motor <NUM> does not reach the first power, and control the speed of the circulation pump motor <NUM> to be decreased when the power supplied to the circulation pump motor <NUM> exceeds the first power.

The main controller <NUM> according to still an embodiment of the present disclosure may control the speed of the circulation pump motor <NUM> to be constant, when the power supplied to the circulation pump motor <NUM> reaches the first power.

Since the power control allows for driving at constant power as described above, the converter <NUM> supplies constant power, thereby improving the stability of the converter <NUM>. In addition, since the power control is performed, it is possible to minimize a decrease in drainage performance according to installation conditions.

Moreover, the circulation pump motor <NUM> may be driven stably, and, therefore, the drainage time may be reduced.

<FIG> is a view showing a power supplied to the motor when the power control or the speed control is performed.

First, when the power control is performed as in the embodiments of the present disclosure, a time-dependent waveform of the power supplied to the circulation pump motor <NUM> may be exemplified as Pwa.

<FIG> illustrates that the power is maintained in a substantially constant manner until time point Tm1 by performing the power control, and the power control is terminated at time point Tm1.

By performing the power control, the main controller <NUM> may control the power supplied to the circulation pump motor <NUM>, during the circulation pumping, to be constant without decreasing over time, although the water level in the washing tub <NUM> is lowered.

By performing the power control, the main controller <NUM> may control the power supplied to the circulation pump motor <NUM>, during the circulation pumping, to be the first power P1.

In particular, even if the lift is changed, the main controller <NUM> may control the power supplied to the circulation pump motor <NUM>, during the circulation pumping, to be the constant first power P1, by performing the power control.

At this time, the constant first power P1 may mean that the circulation pump motor <NUM> is driven with a power within a first allowable range Prag based on the first power P1. For example, the power within the first allowable range Prag may be a power pulsating within about <NUM>% on the basis of the first power P1.

In <FIG>, it is illustrated that when the power control is performed, the circulation pump motor <NUM> is driven with a power within the first allowable range Prag on the basis of the first power P1 from time point Tseta until completion time point Tm1, excluding an overshooting period Pov. Accordingly, water pumping can be performed smoothly even if the lift is changed during the circulation pumping. In addition, the stability of the converter <NUM> can be improved.

Here, the first allowable range Prag may be greater as the first power P1 is at a higher level. In addition, the first allowable range Prag may be greater as a completion period Pbs is longer.

To this end, when the power control is performed during the circulation pumping, the main controller <NUM> may calculate a power based on the output current io and the DC terminal voltage Vdc and output a voltage command value Sn based on the calculated power, and the inverter controller <NUM> may output a switching control signal Sic to the circulation pump motor <NUM> based on the voltage command value Sn.

Meanwhile, the main controller <NUM> may control the voltage command value Sn and a duty of the switching control signal Sic to be greater as the output current io is at a smaller level. Accordingly, the circulation pump motor <NUM> can be driven with a constant power.

Meanwhile, the main controller <NUM> may control the power supplied to the circulation pump motor <NUM> to increase abruptly during a period PoV to perform power control.

Meanwhile, the main controller <NUM> may control the power supplied to the circulation pump motor <NUM> to decrease abruptly from the time point Tm1.

Unlike the embodiments of the present disclosure, when the speed control is performed, that is, when the speed of the circulation pump motor <NUM> is controlled to be maintained constantly, a time-dependent waveform of the power supplied to the circulation pump motor <NUM> may be exemplified as Pwb.

In <FIG>, it is illustrated that the speed control is performed until time point Tm2, and the speed control is terminated at time point Tm2.

The waveform Pwb of the power based on the speed control indicates that, as the water level in the washing tub is lowered during the circulation pumping, the power supplied to the circulation pump motor <NUM> may be gradually reduced while the speed of the circulation pump motor <NUM> is constant.

In <FIG>, it is illustrated that, during a speed control period Pbsx, the power supplied to the circulation pump motor <NUM> is gradually reduced up to approximately Px at the completion time point Tm2.

Accordingly, the time point when the operation of the circulation pump motor <NUM> is terminated at the time of performing speed control is Tm2, which is delayed by approximately period Tx, compared to that at the time of performing power control.

Consequently, according to the embodiments of the present disclosure, since the power control is performed during the circulation pumping, the drainage time can be shortened by approximately period Tx, compared to that at the time of performing speed control. In addition, the power supplied from the converter <NUM> can be kept constant, thereby improving the operation stability of the converter <NUM>.

<FIG> and <FIG> are views illustrating the outer appearance of a circulation pump driving apparatus according to an embodiment of the present disclosure.

Referring to <FIG> and <FIG>, wash water is drained through the drain channel <NUM> connected to the washing tub <NUM>, and the drain channel <NUM> is connected to a water introduction part ITa of the circulation pump <NUM>.

The water introduction part ITa is formed of a hollow tube, and a vortex chamber ROOM with a larger diameter than that of the water introduction part ITa is formed within the water introduction part ITa.

An impeller IPR which rotates by the torque of the circulation pump motor <NUM> is disposed in the vortex chamber ROOM.

Meanwhile, the circulation pump motor <NUM> and a circuit board PCB for applying an electrical signal to the circulation pump motor <NUM> may be disposed on the opposite side of the water introduction part ITa relative to the impeller IPR. The above-described circulation pump driving apparatus <NUM> may be mounted on the circuit board PCB.

Meanwhile, two water discharge parts OTa and OTb for discharging water may be disposed on one side of the vortex chamber ROOM, in a direction intersecting the water introduction part ITa. In this case, the water discharge parts OTa and OTb may be connected to the circulation channel <NUM>.

In this way, the wash water pumped by the circulation pump <NUM> may be introduced into the washing tub <NUM> through the circulation channel <NUM>.

Meanwhile, the water discharge parts OTa and OTb may be formed in a direction normal to the vortex chamber ROOM, for smooth drainage. Such a structure of the circulation pump <NUM> may be called a volute-type drain pump structure.

In the case of such a volute-type drain pump structure, the water discharge parts OTa and OTb are formed on one side of the vortex chamber ROOM. Thus, it is desirable that the circulation pump motor <NUM> rotates clockwise CCW relative to <FIG>.

Meanwhile, as described above, since the drain pipe <NUM> is positioned higher than the circulation pump <NUM>, the water discharge parts OTa and OTb may be sloped in the direction of the drain pipe <NUM>.

Similarly, the water introduction part ITa also may be sloped, and the angle of slope of the water introduction part ITa to the ground may be smaller than the angle of slope of the water discharge parts OTa ans OTb to the ground. Therefore, water is introduced more smoothly into the water introduction part ITa, and the water in the vortex chamber ROOM is discharged through the water discharge parts OTa and OTb by means or the impeller IPR which rotates by the torque of the circulation pump motor <NUM>.

<FIG> is a view referred to in the description of the operation of a circulation pump motor.

Referring to <FIG>, the horizontal axis represents the level of the output current flowing through the circulation pump motor, and the vertical axis represents the washing ratio for laundry in the washing tub <NUM>.

The washing ratio is a numerical value of laundry information for laundry, and the higher the number, the higher the washing power.

Referring to <FIG>, it can be seen that the level of the output current on the horizontal axis increases from right to left, and accordingly, the washing ratio increases.

Therefore, in the present disclosure, a method for increasing the power applied to the circulation pump motor <NUM> is devised such that that washing power by circulation pumping during washing may be improved.

A method capable of improving the washing power by circulation pumping during washing while using efficient power consumption is devised.

To this end, in the present disclosure, a method of operating the circulation pump motor <NUM> with the motion of the washing tub <NUM> is devised.

For example, the circulation pump motor <NUM> operates at a constant speed when rotating with laundry attached to the washing tub <NUM>, and thus it is possible to spray the wash water through spray ports OPa to OPd formed in the washing tub <NUM>, thereby making it possible to improve the washing power.

For another example, the speed of the circulation pump motor <NUM> repeatedly rises and falls when a washing tub motor <NUM> is operated at a speed at which laundry moves in a lower portion of the washing tub <NUM>, and thus it is possible to spray wash water through the spray ports OPa to OPd formed in the washing tub <NUM>, thereby making it possible to improve the washing power.

For another example, the speed of the circulation pump motor <NUM> rises at a first rising slope and a second rising slope and then remains constant when the washing tub motor <NUM> is operated at a speed at which the laundry moves from the lower portion of the washing tub <NUM> to the upper portion and falls from the top, and thus it is possible to spray wash water through the spray ports OPa to OPd formed in the washing tub <NUM>, thereby making it possible to improve the washing power. This will be described with reference to <FIG> and subsequent drawings.

<FIG> is a flowchart illustrating an operation method for a laundry treatment machine according to an embodiment of the present disclosure, and <FIG> illustrate the operation method of <FIG>.

Referring to the drawings, a main controller <NUM> controls the washing tub motor <NUM> to be driven (S1110).

During washing, the washing tub motor <NUM> may operate at a speed at which laundry is attached to the washing tub <NUM>, operate at a speed at which the laundry moves in the lower portion of the washing tub <NUM>, or operate at a speed at which the laundry moves from the lower portion of the washing tub <NUM> to the upper portion and falls from the upper portion.

Next, the main controller <NUM> may control the circulation pump motor <NUM> to be operated in at least two of the first mode to the third mode in response to the operation of the washing tub motor <NUM>. Accordingly, it is possible to improve washing power due to circulation pumping during washing.

Here, the first mode MD1 may represent a mode in which the speed of the circulation pump motor <NUM> is constant, the second mode MD2 may represent a mode in which the speed of the circulation pump motor <NUM> repeatedly rises and falls, and the third mode MD3 may represent a mode in which the speed of the circulation pump motor <NUM> rises at the first rising slope and the second rising slope and then remains constant.

Meanwhile, according to another embodiment of the present disclosure, the main controller <NUM> may control the circulation pump motor <NUM> to be operated in at least two or three modes among the first mode MD1 in which power of the circulation pump motor <NUM> is constant, the second mode MD2 in which the power of the circulation pump motor <NUM> repeatedly risies and falls, and the third mode MD3 in which the power of the circulation pump motor <NUM> rises at the first rising slope and the second rising slope and then remains constant. Accordingly, it is possible to improve washing power due to circulation pumping during washing.

(a) of <FIG> illustrates that the washing tub motor <NUM> operates at a speed at which laundry is attached to the washing tub <NUM>. Accordingly, the main controller <NUM> may control the speed of the circulation pump motor <NUM> to be constant.

Meanwhile, (b) of <FIG> illustrates that the washing tub motor <NUM> operates at a speed at which laundry moves in the lower portion of the washing tub <NUM>. In particular, it is illustrated that the washing tub motor <NUM> operates at a speed at which the laundry moves in a lower portion Ara based on an imaginary line Wref, when the washing tub <NUM> is cylindrical.

Accordingly, the main controller <NUM> may perform control such that the speed of the circulation pump motor <NUM> repeatedly rises and falls.

(c) of <FIG> illustrates that the washing tub motor <NUM> operates at a speed at which laundry is attached to the washing tub <NUM>. In particular, it is illustrated that the washing tub motor <NUM> operates at a speed at which the laundry moves from a lower portion Ara of the washing tub <NUM> to an upper portion Arb thereof and falls from the upper portion Arb based on an imaginary line Wref, when the washing tub <NUM> is cylindrical.

Accordingly, the main controller <NUM> may perform control such that the speed of the circulation pump motor <NUM> rises at the first rising slope and second rising slope and then remains constant.

As illustrated in FIGS. (a) to (c) of <NUM>, in the main controller <NUM> is, the first mode MD1 of (a) of <FIG>, the second mode MD2 of (b) of <FIG>, and the third mode MD3 of (c) of <FIG> are performed sequentially, and may be controlled to be repeatedly performed. Accordingly, it is possible to improve washing power due to circulation pumping during washing.

<FIG> is a diagram illustrating the first mode MD1 of (a) of <FIG> in detail.

Referring to the drawing, in the first mode MD1, in order to rotate with the circulation pump motor <NUM> at a constant speed, the main controller <NUM> may increase the speed of the circulation pump motor <NUM> at a rising slope Sa1 and decrease the speed of the circulation pump motor <NUM> at a falling slope Sa3.

In this case, the rising slope and the falling slope may differ only in polarity, and have the same magnitude.

<FIG> is a diagram illustrating the second mode MD2 of (b) of <FIG> in detail.

Referring to <FIG>, in the second mode MD2, for the speed of the circulation pump motor <NUM> to repeatedly rise and fall, the main controller <NUM> may increase the speed of the circulation pump motor <NUM> at a rising slope Sb1, increase the speed of the circulation pump motor <NUM> at a rising slope Sb2, and decrease the speed of the circulation pump motor <NUM> at a falling slope Sb3, and then may further repeatedly rise and fall twice at the rising slope Sb2 and the falling slope Sb3 and decrease the speed of the circulation pump motor <NUM> at a falling slope Sb8.

In this case, it is desirable that the rising slope Sb1 is larger than the rising slope Sb2. Accordingly, it is possible to quickly increase the speed of the circulation pump motor <NUM>.

Meanwhile, the rising slope Sb2 and the falling slope Sb3 may differ only in polarity and may have the same magnitude.

In addition, the rising slope Sb1 and the falling slope Sb8 may differ only in polarity and may have the same magnitude.

<FIG> is a diagram illustrating the third mode MD2 of (c) of <FIG> in detail.

Referring to <FIG>, in the third mode MD3, for the speed of the circulation pump motor <NUM> to repeatedly rise and fall, the main controller <NUM> may increase the speed of the circulation pump motor <NUM> at a rising slope Sc1, increase the speed of the circulation pump motor <NUM> at a rising slope Sc2, and rotate at a constant speed, and then decrease the speed of the circulation pump motor <NUM> at a falling slope Sc4.

In this case, it is desirable that the rising slope Sc1 is larger than the rising slope Sc2. Accordingly, it is possible to quickly increase the speed of the circulation pump motor <NUM>.

Meanwhile, the rising slope Sc2 of <FIG> may be the same as the rising slope Sb2 of <FIG>.

<FIG> illustrates that the first mode to the third mode are performed based on power.

Referring to <FIG>, the main controller <NUM> may control the circulation pump motor <NUM> to be operated in at least two or three modes among the first mode MD1 in which power of the circulation pump motor <NUM> is constant, as illustrated in (a) of <FIG>, the second mode MD2 in which the power of the circulation pump motor <NUM> repeatedly rises and falls, as illustrated in (b) of <FIG>, and the third mode MD3 in which the power of the circulation pump motor <NUM> rises at the first rising slope and the second rising slope and then remains constant, as illustrated in (c) of <FIG>.

As described above, the first mode of (a) of <FIG> may be performed when the washing tub motor <NUM> operates at a speed at which laundry is attached to the washing tub <NUM>, the second mode of (b) of <FIG> may be performed when the washing tub motor <NUM> operates at a speed at which the laundry moves in the low portion of the washing tub <NUM>, and the third mode of (c) of <FIG> may be performed when washing tub motor <NUM> operates at a speed at which the laundry moves from the lower portion of the washing tub <NUM> to the upper portion and falls from the upper portion. Accordingly, it is possible to improve washing power due to circulation pumping during washing.

<FIG> illustrates that, while the washing tub motor <NUM> is stopped, the circulation pump motor <NUM> is also stopped, and the wash water is not sprayed through the spray ports OPa to OPd formed in the washing tub <NUM>.

Next, <FIG> illustrates that wash water circulated by pumping of the circulation pump <NUM> is sprayed through the spray ports OPa to OPd formed in the washing tub <NUM> by the rotation of the washing tub motor <NUM> and the synchronous rotation of the circulation pump motor <NUM> therewith.

To this end, the main controller <NUM> may perform control such that, in synchronization with the operation timing of the washing tub motor <NUM>, the wash water circulated of pumping by the circulation pump <NUM> is sprayed through the spray ports OPa to OPd formed in the washing tub <NUM>.

In particular, <FIG> illustrates that the wash water circulated of pumping by the circulation pump <NUM> is strongly sprayed when operating with R1 power in (a) of <FIG>, operating with R3 power in (b) of <FIG> or operating with R5 power in (c) of <FIG>.

In particular, <FIG> illustrates that the wash water circulated of pumping by the circulation pump <NUM> is weakly sprayed when operating with R2 power in (b) of <FIG> or operating with R4 power in (c) of <FIG>.

Meanwhile, <FIG> illustrates a frond loading type machine as a laundry treatment machine, but the circulation pump driving apparatus <NUM> according to an embodiment of the present disclosure may also be applied to a top loading type.

Meanwhile, the circulation pump driving apparatus <NUM> according to an embodiment of the present disclosure may be applied to various machines such as dishwashers and air conditioners, in addition to the laundry treatment machine <NUM>.

The circulation pump driving apparatus and the laundry treatment machine including the same according to embodiments of the present disclosure are not limited to the configurations and methods of the above-described embodiments, and various modifications to the embodiments may be made by selectively combining all or some of the embodiments.

Claim 1:
A circulation pump driving apparatus (<NUM>) comprising:
a circulation pump motor (<NUM>) configured to operate a circulation pump (<NUM>) for circulating wash water introduced from a washing tub (<NUM>) by pumping;
a converter (<NUM>) configured to output a direct current (DC) voltage;
an inverter (<NUM>) configured to convert the DC voltage from the converter (<NUM>) into an alternating current (AC) voltage by a switching operation and to output the converted AC voltage to the circulation pump motor (<NUM>);
a controller (<NUM>) configured to control the circulation pump motor (<NUM>) to operate in at least two modes among a first mode in which one of a speed and a power of the circulation pump motor (<NUM>) is constant, a second mode in which the one of the speed and the power of the circulation pump motor (<NUM>) repeatedly rises and falls, and a third mode in which the one of the speed and the power of the circulation pump motor (<NUM>) rises at a first rising slope (Sc1) and a second rising slope (Sc2), and then remains constant,
wherein, in the second mode, the controller (<NUM>) is configured to increase the speed of the circulation pump motor (<NUM>) at a third rising slope (Sb1), to then increase the speed of the circulation pump motor (<NUM>) at a fourth rising slope (Sb2), to then decrease the speed of the circulation pump motor (<NUM>) at a first falling slope (Sb3), to then repeatedly rise and fall twice at the fourth rising slope (Sb2) and at the first falling slope (Sb3), respectively, and to then decrease the speed of the circulation pump motor (<NUM>) at a second falling slope (Sb8), and
wherein the third rising slope (Sb1) is larger than the fourth rising slope (Sb2).