Washing machine and control method of washing machine

Abstract

A washing machine includes: a drum configured to be rotatable inside a tub; a motor including a stator and a rotor and configured to rotate the drum; an inverter circuit connected to the motor; and at least one processor configured to compensate for a q-axis current command value (m is a natural number) of the motor based on an m-order harmonic component and a position of the rotor, and control the inverter circuit to drive the motor based on the compensated q-axis current command value, the m-order harmonic component being filtered by the band-pass filter from a speed error value of the rotor.

Description

Technical Field

[0001] The present disclosure relates to a washing machine and a method for controlling the same, and more particularly, to a washing machine including a motor that rotates a drum and a method for controlling the same. Background Art

[0002] Generally, a washing machine may include a tub, a drum rotatably mounted in the tub, and a motor for rotating the drum, and may wash clothes by rotating the drum containing clothes in the tub. The washing machine may perform a washing process for washing clothes, a rinsing process for rinsing the washed clothes, and a spin drying process for spin drying clothes.

[0003] During the spin drying process, the water absorbed in the clothes can be separated from the clothes by controlling the motor to make the drum containing the clothes rotate at a high speed.

[0004] Due to the magnetic interaction between the rotor and stator, the motor can generate cogging torque. Cogging torque generates torque ripple in the form of specific harmonic components, which causes torque ripple in the motor.

[0005] Motor torque fluctuations can cause vibration and shock in the motor, resulting in motor noise. Motor noise is transmitted to the surrounding structure connected to the motor and can be significantly amplified when the motor noise coincides with the natural resonant frequency of the surrounding structure. Summary of the Invention

[0006] [Technical Issues]

[0007] An aspect of the present disclosure provides a washing machine and a method for controlling the same, which can reduce noise of a motor by offsetting harmonic components generated by the motor.

[0008] The technical objectives that can be achieved by the present disclosure are not limited to the above-mentioned objectives, and a person skilled in the art in the art to which the present disclosure belongs will clearly understand other technical objectives that are not mentioned based on the following description.

[0009] [Technical solution]

[0010] According to aspects of the present disclosure, a washing machine may include: a drum configured to rotate inside a tub; a motor including a stator and a rotor and configured to rotate the drum; an inverter circuit connected to the motor; and at least one processor configured to compensate a q-axis current command value of the motor based on an m-order harmonic component (m is a natural number) and a position of a rotor, and control the inverter circuit to drive the motor based on the compensated q-axis current command value, wherein the m-order harmonic component is filtered from a speed error value of the rotor by a bandpass filter.

[0011] According to one aspect of the present disclosure, a method for controlling a washing machine, the washing machine comprising: a drum configured to rotate inside a tub; and a motor comprising a stator and a rotor and configured to rotate the drum, the method may include: filtering a speed error value of the rotor by a bandpass filter to obtain a preset m-order harmonic component (m is a natural number); compensating a q-axis current command value of the motor based on the filtered m-order harmonic component and the position of the rotor; and driving the motor based on the compensated q-axis current command value. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 The exterior of a washing machine according to an embodiment is shown.

[0013] Figure 2 is a side sectional view of a washing machine according to an embodiment.

[0014] Figure 3 A motor of a washing machine according to an embodiment is shown.

[0015] Figure 4 is a control block diagram illustrating a washing machine according to an embodiment.

[0016] Figure 5 is a control block diagram illustrating a control circuit of a washing machine according to an embodiment.

[0017] Figure 6 is a flowchart illustrating a method for controlling a washing machine according to an embodiment.

[0018] Figure 7 An example of an operation cycle of the washing machine according to the embodiment is shown.

[0019] Figure 8 An active feedforward controller (AFC) of a control circuit of a washing machine according to an embodiment is shown.

[0020] Figure 9 An example of AFC of a control circuit of a washing machine according to an embodiment is shown.

[0021] Figure 10 is a flowchart illustrating an operation of canceling a 36th-order harmonic component included in a q-axis current command of a motor in a washing machine according to an embodiment.

[0022] Figure 11 The change of the 36th order noise component in the AFC in the washing machine according to the embodiment in the activated state and the deactivated state is shown.

[0023] Figure 12 is a control block diagram illustrating a control circuit of a washing machine according to another embodiment.

[0024] Figure 13is a flowchart illustrating an operation of selecting and activating one of a plurality of AFCs in a washing machine according to another embodiment. DETAILED DESCRIPTION

[0025] The various embodiments of the present disclosure and the terms used therein are not intended to limit the technical features described in the present disclosure to specific embodiments, but should be construed as including various modifications, equivalents, or substitutes of the corresponding embodiments.

[0026] Regarding the description of the drawings, like reference numerals may be used for similar or related components.

[0027] Unless otherwise indicated herein or clearly contradicted by context, a singular expression may include a plural expression.

[0028] The expressions "A or B", "at least one of A or / and B" or "one or more of A or / and B", "A, B or C", "at least one of A, B or / and C" or "one or more of A, B or / and C" etc. used herein may include any and all combinations of one or more of the associated listed items.

[0029] The term "and / or" includes plural combinations of related items or any one item among the plural related items.

[0030] Herein, the expressions “first,” “second,” or variations thereof may be used simply to distinguish an element from other elements, but are not limited to another aspect (eg, importance or sequence) of the elements.

[0031] When an element (e.g., a first element) is referred to as being "(functionally or communicatively) coupled" or "connected" to another element (e.g., a second element), the first element may be connected to the second element directly (e.g., wired), wirelessly, or through a third element.

[0032] In the present disclosure, the terms "including", "having" and the like are used to specify features, quantities, steps, operations, elements, components or a combination thereof, but do not exclude the existence or addition of one or more of the features, elements, steps, operations, elements, components or a combination thereof.

[0033] When an element is referred to as being “connected,” “coupled,” “supported,” or “in contact with” another element, this includes not only the case where the elements are directly connected, coupled, supported, or in contact with each other, but also the case where the elements are indirectly connected, coupled, supported, or in contact with each other through a third element.

[0034] Throughout this specification, when an element is “on” another element, this includes not only a case where the element is in contact with the other element but also a case where the other element exists between the two elements.

[0035] The washing machine according to various embodiments can perform washing, rinsing, spin drying, and drying processes. A washing machine is an example of a clothing care device, and a clothing care device is a concept including an apparatus capable of washing clothes (objects to be washed and objects to be dried), an apparatus capable of drying clothes, and an apparatus capable of washing and drying clothes.

[0036] The washing machine according to various embodiments may include a top-loading washing machine in which a laundry inlet for inserting or withdrawing laundry is disposed facing upward, or a front-loading washing machine in which the laundry inlet is disposed facing forward. The washing machine according to various embodiments may include a washing machine of a loading type other than the top-loading washing machine and the front-loading washing machine.

[0037] In a top-loading washing machine, laundry can be washed using a water flow generated by a rotating body such as a pulsator. In a front-loading washing machine, laundry can be washed by repeatedly lifting and lowering the laundry by rotating the drum. A front-loading washing machine may include a dryer-type washing machine capable of drying the laundry stored in the drum. The dryer-type washing machine may include a hot air supply device for supplying high-temperature air into the drum and a condensing device for removing moisture from the air exhausted from the drum. For example, the dryer-type washing machine may include a heat pump device. Washing machines according to various embodiments may include washing machines using washing methods other than the above-described washing methods.

[0038] The washing machine according to various embodiments may include a housing that accommodates various components. The housing may be provided in the form of a box including a laundry inlet on one side thereof.

[0039] The washing machine may include a door for opening and closing the laundry inlet. The door may be rotatably mounted to the housing via a hinge. At least a portion of the door may be transparent or translucent to allow viewing into the housing.

[0040] The washing machine may include a tub arranged inside the housing to store water. The tub may be formed in a generally cylindrical shape with a tub opening formed at one side thereof. The tub may be arranged inside the housing so that the tub opening corresponds to the laundry inlet.

[0041] The tub may be connected to the housing via a damper that absorbs vibrations generated when the drum rotates and reduces the vibrations transmitted to the housing.

[0042] A washing machine may include a drum arranged to receive laundry.

[0043] The drum can be arranged inside the barrel so that the drum opening arranged at one side of the drum corresponds to the clothing inlet and the barrel opening. Clothes can pass through the clothing inlet, the barrel opening and the drum opening in sequence and then be accommodated in the drum or drawn out from the drum.

[0044] The drum can perform each operation according to washing, rinsing and / or spin drying when rotating inside the tub. A plurality of through holes can be formed in the cylindrical wall of the drum to allow water stored in the tub to be introduced into the drum or drained from the drum.

[0045] The washing machine may include a driver configured to rotate the drum. The driver may include a drive motor and a rotating shaft for transmitting the driving force generated by the drive motor to the drum. The rotating shaft may pass through the tub to connect to the drum.

[0046] The driver may perform corresponding operations according to a washing, rinsing and / or spin drying or drying process by rotating the drum in a forward or reverse direction.

[0047] The washing machine may include a water supply device configured to supply water to the tub. The water supply device may include a water supply pipe and a water supply valve disposed in the water supply pipe. The water supply pipe may be connected to an external water supply source. The water supply pipe may extend from the external water supply source to the detergent supply device and / or the tub. Water may be supplied to the tub via the detergent supply device. Alternatively, water may be supplied to the tub without passing through the detergent supply device.

[0048] The water supply valve can open or close the water supply pipe in response to an electrical signal from the control circuit. The water supply valve can allow or prevent water from being supplied to the tub from an external water supply source. The water supply valve can include a solenoid valve configured to open and close in response to the electrical signal.

[0049] The washing machine may include a detergent supply device configured to supply detergent to the tub. The detergent supply device may include a manual detergent supply device and an automatic detergent supply device. The manual detergent supply device requires the user to put in the detergent to be used for each wash, and the automatic detergent supply device stores a large amount of detergent and automatically puts in a predetermined amount of detergent during the wash. The detergent supply device may include a detergent box for storing detergent. The detergent supply device may be configured to supply detergent to the tub during the water supply process. The water supplied by the water supply pipe may be mixed with the detergent via the detergent supply device. The water mixed with the detergent may be supplied to the tub. Detergent is used as a term including detergents for pre-washing, detergents for main wash, fabric softener, bleach, etc., and the detergent box may be divided into a storage area for pre-wash detergent, a storage area for main wash detergent, a storage area for fabric softener, and a storage area for bleach.

[0050] The washing machine may include a drainage device configured to drain water contained in the tub to the outside. The drainage device may include a drain pipe extending from the bottom of the tub to the outside of the housing, a drain valve provided on the drain pipe to open and close the drain pipe, and a pump provided on the drain pipe. The pump may pump water from the drain pipe to the outside of the housing.

[0051] The washing machine may include a control panel disposed on one side of the housing. The control panel may provide a user interface for interaction between the user and the washing machine. The user interface may include at least one input interface and at least one output interface.

[0052] The at least one input interface may convert sensing information received from a user into an electrical signal.

[0053] The at least one input interface may include a power button, an operation button, a process selection dial (or process selection button), and a wash / rinse / spin-dry setting button. The at least one input interface may include a tactile switch, a push button switch, a slide switch, a toggle switch, a micro switch, a touch switch, a touch pad, a touch screen, a jog dial, and / or a microphone.

[0054] The at least one output interface may visually or auditorily transmit information related to the operation of the washing machine to the user.

[0055] For example, at least one output interface can transmit information related to the washing process, the operating time of the washing machine, and the wash / rinse / spin dry settings to the user. The operating information about the washing machine can be output via a screen, an indicator, or voice. The at least one output interface can include a liquid crystal display (LCD) panel, a light-emitting diode (LED) panel, or a speaker.

[0056] The washing machine may include a communication module for wired and / or wireless communication with an external device.

[0057] The communication module may include at least one of a short-range wireless communication module and a long-range wireless communication module.

[0058] The communication module can send data to or receive data from an external device (e.g., a server, a user device, and / or a home appliance). For example, the communication module can establish communication with a server and / or a user device and / or a home appliance, and send and receive various types of data.

[0059] For communication, the communication module can establish a direct (e.g., wired) communication channel or a wireless communication channel between external devices and support the execution of communication through the established communication channel. Depending on the embodiment, the communication module may include a wireless communication module (e.g., a cellular communication module, a short-range wireless communication module, or a global navigation satellite system (GNSS) communication module) or a wired communication module (e.g., a local area network (LAN) communication module or a power line communication module). Among these communication modules, the corresponding communication module can communicate with the external device via a first network (e.g., a short-range wireless communication network such as Bluetooth, Wireless Fidelity (Wi-Fi) Direct, or Infrared Data Association (IrDA)) or a second network (e.g., a long-range wireless communication network such as a traditional cellular network, a 5G network, a next-generation communication network, the Internet, or a computer network (e.g., a LAN or WAN)). These various types of communication modules can be integrated into one component (e.g., a single chip) or implemented as multiple separate components (e.g., multiple chips).

[0060] The short-range wireless communication module may include a Bluetooth communication module, a Bluetooth Low Energy (BLE) communication module, a near field communication module, a WLAN (Wi-Fi) communication module, a Zigbee communication module, an Infrared Data Association (IrDA) communication module, a Wi-Fi Direct (WFD) communication module, an Ultra-Wideband (UWB) communication module, an Ant+ communication module, a microwave (uWave) communication module, etc., but is not limited thereto.

[0061] The long-distance wireless communication module may include a communication module that performs various types of long-distance wireless communications and may include a mobile communication circuit that transmits and receives radio signals with at least one of a base station, an external terminal, and a server on a mobile communication network.

[0062] According to an embodiment, the communication module can communicate with external devices such as servers, user devices, and other home appliances through an access point (AP). The access point (AP) can connect a local area network (LAN) to which the washing machine or user device is connected to a wide area network (WAN) to which the server is connected. The washing machine or user device can be connected to the server through a wide area network (WAN). The control circuit can control various components of the washing machine (e.g., a drive motor and a water supply valve). The control circuit can control the various components of the washing machine to perform at least one operation including water supply, washing, rinsing, and / or spin drying according to user input. For example, the control circuit can control the drive motor to adjust the rotation speed of the drum, or control the water supply valve of the water supply device to supply water to the tub.

[0063] The control circuit may include hardware such as a CPU or memory and software such as a control program. For example, the control circuit may include: at least one memory for storing algorithms and program-type data to control the operation of components in a washing machine; and at least one processor configured to perform the above operations by using the data stored in the at least one memory. The memory and the processor may each be implemented as a separate chip. The processor may include one or more processor chips, or may include one or more processing cores. The memory may include one or more memory chips or one or more memory blocks. Alternatively, the memory and the processor may be implemented as a single chip.

[0064] Hereinafter, a washing machine according to an embodiment of the present disclosure will be described in detail with reference to the accompanying drawings.

[0065] Figure 1 The exterior of a washing machine according to an embodiment is shown. Figure 2 is a side sectional view of a washing machine according to an embodiment.

[0066] refer to Figure 1 and Figure 2 The washing machine 100 may be a drum type washing machine that rotates the drum 130 and repeatedly raises and lowers the laundry to wash the laundry. The washing machine 100 may be a motor-operated washing machine that washes the laundry using a water flow generated by a pulsator when the drum 130 rotates.

[0067] That is, the method for controlling the washing machine 100 according to the present disclosure is applicable to both a drum type washing machine and a motor operation type washing machine. However, in the embodiment described below, a drum type washing machine is described as an example of the washing machine 100 for description.

[0068] refer to Figure 1 and Figure 2 The washing machine 100 may include a cabinet 101. The washing machine 100 may further include a door 102, a user interface 110, a tub 120, a drum 130, a driver 140, a water supply device 150, a drainage device 160, and a detergent supply device 170, all of which are accommodated in the cabinet 101.

[0069] The cabinet 101 may have an opening 101 a formed at a front side thereof, through which laundry may be inserted and withdrawn.

[0070] The opening 101a may be provided with a door 102. The door 102 may be rotatably installed at the front side of the cabinet 101 by a hinge.

[0071] The opening 101a may be opened or closed by the door 102, and closing of the opening 101a by the door 102 may be detected by the door switch 103. In response to the opening 101a being closed to start operating the washing machine 100, the door 102 may be locked by the door lock 104.

[0072] On the front upper side of the cabinet 101 , the user interface 110 includes an input interface for receiving a user input of the washing machine 100 from a user and a display for displaying operation information of the washing machine 100 .

[0073] The tub 120 may be disposed inside the cabinet 101 and may contain water for washing and / or rinsing.

[0074] The tub 120 may include a tub front 121 having an opening 121 a formed on a front side and a tub rear 122 having a cylindrical shape with a closed rear side.

[0075] An opening 121a for placing laundry into or taking laundry out of the drum 130 provided in the tub 120 may be provided at the front side of the tub front 121. A bearing 122a for rotatably fixing the motor 141 may be provided on the rear wall of the tub rear 122.

[0076] The drum 130 may be provided inside the tub 120 to be rotatable about a rotation axis R extending in the front-rear direction, and may accommodate laundry.

[0077] The drum 130 may include a drum body 131 having a cylindrical shape, a drum front 132 disposed in front of the drum body 131 , and a drum rear 133 disposed behind the drum body 131 .

[0078] The inner surface of the drum body 131 may be provided with a through hole 131a connecting the interior of the drum 130 and the interior of the tub 120, and a lifter 131b for lifting laundry to the upper portion of the drum 130 when the drum 130 rotates. The drum front portion 132 may be provided with an opening 132a for placing laundry into or removing laundry from the drum 130. The drum rear portion 133 may be connected to a shaft 141a of a motor 141 that rotates the drum 130.

[0079] The driver 140 may include a motor 141 that rotates the drum 130 .

[0080] The motor 141 may be provided outside the tub rear 122 of the tub 120 and may be connected to the drum rear 133 of the drum 130 via a shaft 141a. The shaft 141a penetrates the tub rear 122 and is rotatably supported by a bearing 122a provided therein.

[0081] The motor 141 may include a stator 142 fixed to the outside of the tub rear 122 and a rotor 143 rotatable and connected to the shaft 141a. The rotor 143 may rotate by interacting with the stator 142 through magnetic force, and the rotation of the rotor 143 may be transmitted to the drum 130 through the shaft 141a.

[0082] For example, the motor 141 may include a permanent magnet synchronous motor (PMSM) or a brushless direct current (BLDC) motor whose rotation speed is easily controlled.

[0083] The water supply device 150 may supply water to the tub 120 .

[0084] The water supply device 150 may include a water supply pipe 151 connected to an external water supply source to supply water to the tub 120 , and a water supply valve 152 provided on the water supply pipe 151 .

[0085] The water supply pipe 151 is provided above the tub 120 and may extend from an external water supply source to the detergent box 171. Water may be guided to the tub 120 through the detergent box 171.

[0086] The water supply valve 152 may allow or prevent water from being supplied from an external water supply source to the tub 120 in response to an electrical signal. The water supply valve 152 may include, for example, a solenoid valve that opens and closes in response to an electrical signal.

[0087] The drain device 160 may drain water contained in the tub 120 and / or the drum 130 to the outside.

[0088] The drainage device 160 includes a drainage pipe 161 provided below the tub 120 and extending from the tub 120 to the outside of the cabinet 101, and a drainage pump 162 provided on the drainage pipe 161. The drainage pump 162 can pump water in the drainage pipe 161 to the outside of the cabinet 101.

[0089] The detergent supply device 170 may supply detergent to the tub 120 and / or the drum 130 .

[0090] The detergent supply device 170 may include a detergent box 171 disposed above the tub 120 to store detergent, and a mixing pipe 172 connecting the detergent box 171 to the tub 120 .

[0091] The detergent box 171 may be connected to the water supply pipe 151, and water supplied through the water supply pipe 151 may be mixed with the detergent in the detergent box 171. The mixture of the detergent and water may be supplied to the tub 120 through the mixing pipe 172.

[0092] Figure 3 A motor of a washing machine according to an embodiment is shown.

[0093] refer to Figure 3The motor 141 may include a stator 142 and a rotor 143 . In an embodiment, the motor 141 may be provided with a rotor 143 on a radially outer side of one stator 142 .

[0094] In an embodiment, the rotor 143 may be connected to the drum 130 .

[0095] The rotor 143 shares the coil 142 a of the stator 142 , and the motor 141 may rotate the rotor 143 by receiving current (eg, three-phase current or six-phase current) from the coil 142 a .

[0096] In an embodiment, the rotor 143 may be disposed outside the stator 142 .

[0097] In various embodiments, the rotor 143 may be disposed inside the stator 142 .

[0098] The rotor 143 is a cylindrical member having a flat bottom, and may include a rotor yoke 143 a erected around the circumference of the bottom and a plurality of magnets 143 b made of arc-shaped permanent magnets.

[0099] According to various embodiments, the 48 magnets 143 b may be arranged such that N poles and S poles are continuously alternately arranged in a circumferential direction, and may be fixed to the inner surface of the rotor yoke 143 a .

[0100] The stator 142 may be formed as an annular member having an outer diameter smaller than an inner diameter of the rotor 143. The stator 142 may be provided with a plurality of teeth 142b embedded in resin, coils 142a, etc. According to various embodiments, the stator 142 may be provided with 36 I-shaped teeth 142b and coils 142a.

[0101] The teeth 142b may be thin plate-shaped steel members having an I-shaped longitudinal cross-section and may be arranged around the entire circumference of the stator 142 so that each tooth is radially arranged at equal intervals. The inner and outer circumferential ends of the teeth 142b may protrude from both ends in a flange shape in the circumferential direction.

[0102] The coil 142a of each tooth 142b can be formed by continuously winding a plurality of conductive wires (e.g., six conductive wires) coated with an insulating material in a predetermined order and configuration. A group of teeth 142b on which the coil 142a is formed can be embedded in a thermosetting resin by molding, with only each diameter-side end surface exposed, and can be fixed in a regular arrangement in an insulated state.

[0103] According to various embodiments, each coil 142 a may be formed by winding each of six wires around each of the 36 I-shaped teeth 142 b in a predetermined order.

[0104] The stator 142 and the rotor 143 are attached so that the ends of the teeth 142 b on the rotor 143 side face the magnets 143 b with a small gap.

[0105] The motor 141 according to the embodiment may be designed to include 36 slots S of the stator 142 and 48 poles P of the rotor 143 .

[0106] As described above, the rotor 143 may be connected to the shaft 141 a , and thus the rotor 143 may be connected to the drum 130 .

[0107] The washing machine 100 according to the embodiment may include not only Figure 1 and Figure 2 The mechanical components described above may also include the electrical / electronic components described below.

[0108] Figure 4 is a control block diagram illustrating a washing machine according to an embodiment.

[0109] refer to Figure 4 , the washing machine 100 may include a user interface 110 , a driver 140 , a water supply device 150 , a drainage device 160 , a sensor 180 , and a control circuit 190 .

[0110] The user interface 110 may include input buttons for obtaining user input, and a display for displaying washing settings and / or washing operation information in response to the user input. For example, the input buttons may include a power button, an operation button, a course selection dial, and detailed setting buttons. The display may include a screen for displaying the washing course selected by rotating the course selection dial and the operating time of the washing machine 100, and an indicator for displaying the detailed settings selected by the setting buttons. The input buttons and the display may be provided separately, or may be integrated into a touch screen.

[0111] Here, the washing process may include washing settings (e.g., washing temperature, number of rinses, spin drying intensity, etc.) pre-set by the designer of the washing machine 100 according to the type of clothing (e.g., bedding, underwear, etc.) and material (e.g., wool, etc.). For example, standard wash may include washing settings that can be applied to most clothing, and bedding wash may include washing settings optimized for washing bedding. Washing processes may be divided into, for example, standard wash, power wash, delicate laundry wash, bedding wash, baby laundry wash, towel wash, small wash, boiling wash, energy-saving wash, outdoor laundry wash, rinse / spin dry, spin dry, etc.

[0112] The sensor 180 may detect data indicating a state of the washing machine 100. The data detected by the sensor 180 may be transmitted to the control circuit 190.

[0113] For example, the sensor 180 may include a current sensor 181. The current sensor 181 can detect the current value supplied to the motor 141, and the number of current sensors 181 is not limited. Furthermore, the current sensor 181 can be located anywhere as long as it can detect the current supplied to the motor 141. For example, the current sensor 181 can be located in all three-phase circuits to measure all three-phase currents, but according to embodiments, the current sensor 181 may be located in only two of the three-phase circuits. The motor current information detected by the current sensor 181 may be transmitted to the control circuit 190.

[0114] In addition, the sensor 180 may include a speed sensor 182. The speed sensor 182 may detect the speed of the rotor 143 of the motor 141. The speed sensor 182 may include an encoder, a Hall sensor, or a rotary transformer. The rotor speed information detected by the speed sensor 182 may be sent to the control circuit 190.

[0115] The driver 140 may supply a driving current for driving the motor 141 to the motor 141 in response to a control signal from the control circuit 190 .

[0116] The driver 140 can drive the motor 141 through the inverter circuit 144. The inverter circuit 144 may include an inverter including a plurality of switching element pairs. The inverter may convert DC power into DC driving power or AC driving power, and may supply a three-phase driving current to the motor 141. The inverter circuit 144 may include two switching elements (Q1 and Q2, Q3 and Q4, Q5 and Q6), wherein each pair of switching element pairs (Q1 and Q2, Q3 and Q4, Q5 and Q6) are connected in series with each other. The switching elements (Q1, Q2, Q3, Q4, Q5, Q6) included in the inverter circuit 144 may be turned on / off according to a control signal from the control circuit 190, and a three-phase driving current (I a , I b , I c ).

[0117] In addition to the inverter circuit 144, the driver 140 may also include a rectifier circuit and a DC link circuit. The rectifier circuit may include a diode bridge comprising a plurality of diodes and may rectify AC power from an external power source. The DC link circuit may include a DC link capacitor for storing electrical energy and may remove ripple from the rectified power to output DC power.

[0118] The control circuit 190 may be electrically connected to the user interface 110 , the driver 140 , the water supply device 150 , the drainage device 160 , and the sensor 180 .

[0119] The control circuit 190 may include a processor 191 that generates a control signal for controlling the operation of the washing machine 100 , and a memory 192 that stores a program and data for generating the control signal for controlling the operation of the washing machine 100 .

[0120] The processor 191 and the memory 192 may be implemented in separate semiconductor devices or a single semiconductor device. In addition, the control circuit 190 may include a plurality of processors 191 and a plurality of memories 192.

[0121] The processor 191 may process data and / or signals according to a program provided from the memory 192 and provide a control signal to each component of the washing machine 100 based on the processing result.

[0122] The processor 191 may receive a user input from the user interface 110 and may process the user input.

[0123] In response to user input, the processor 191 may output control signals for controlling the motor 141, the water supply valve 152, the drain pump 162, and the door lock. For example, the processor 191 may control the motor 141, the water supply valve 152, the drain pump 162, and the door lock to sequentially perform a washing process, a rinsing process, and a spin-drying process. Furthermore, the processor 191 may output control signals for controlling the user interface 110 to display washing settings and washing operation information in response to user input.

[0124] The processor 191 may include an arithmetic circuit, a memory circuit, and a control circuit. The processor 191 may include a single chip or multiple chips. In addition, the processor 191 may include a single core or multiple cores.

[0125] The memory 192 may store a program for performing a washing operation according to a washing course and data including settings for operations according to the washing course. In addition, the memory 192 may store a currently selected washing course and washing settings based on a user input.

[0126] Memory 192 may include volatile memory (e.g., static random access memory (SRAM) or dynamic random access memory (DRAM)) and nonvolatile memory (e.g., read-only memory (ROM) or erasable programmable read-only memory (EPROM). Memory 192 may include a single memory or multiple memories.

[0127] The control circuit 190 can input a pulse width modulated (PWM-controlled) electrical signal to the inverter circuit 144 using a predetermined command signal and a carrier wave composed of a triangular wave, and can apply a DC voltage to the motor 141. Each of the switching elements (Q1, Q2, Q3, Q4, Q5, Q6) of the inverter circuit 144 can be turned on or off based on the electrical signal (PWM control signal) output from the control circuit 190, thereby adjusting the power supplied to the motor 141 through a combination of turning on and off.

[0128] The control circuit 190 can adjust the electrical signal (PWM control signal) input to the inverter circuit 144 based on the target speed of the drum 130 calculated according to the motor current detected by the current sensor 181 or the rotor speed detected by the speed sensor 182 to allow the drum 130 to rotate at the target speed.

[0129] Figure 5 is a control block diagram illustrating a control circuit of a washing machine according to an embodiment.

[0130] refer to Figure 5 The control circuit 190 and the motor 141 are connected via the inverter 144a of the inverter circuit 144. The inverter 144a may transmit a driving voltage to the motor 141 based on an electrical signal output from the control circuit 190. The operation of the rotor 143 of the motor 141 may be controlled based on the driving voltage transmitted from the inverter.

[0131] The current sensor 181 may be connected to the inverter 144a. The current sensor 181 may detect the current flowing in each phase of the inverter 144a. The current sensor 181 may detect the three-phase current I output from the inverter 144a. abc (a-phase current, b-phase current, c-phase current). The current sensor 181 can send the detected three-phase current values ​​to the control circuit 190. The current sensor 181 can only measure the three-phase current I abc The two-phase currents in the circuit 190 can be used to estimate the other phase current based on the two-phase currents.

[0132] A speed sensor 182 for detecting the speed of the rotor 143 may be connected to the motor 141. The speed sensor 182 may detect the speed of the rotor 143 of the motor 141. The speed sensor 182 may transmit the detected speed value ω of the rotor 143 to the control circuit 190. The speed sensor 182 may be implemented as a Hall sensor, an encoder, a resolver, or the like. Instead of the speed sensor 182, a position sensor may be used that detects the position θ of the rotor 143. In this case, the control circuit 190 may estimate the speed value ω of the rotor 143 by differentiating the rotor position value detected by the position sensor.

[0133] The control circuit 190 may include a speed controller 200 , a current controller 210 , a voltage converter 220 , a current converter 230 , a position calculator 240 , and an active feedforward controller (AFC, 250 ).

[0134] The speed controller 200 can compare the speed command ω of the control circuit 190 with * and the speed value ω of the rotor 143, and the d-axis current command I can be output based on the comparison result. d* and q-axis current command I q* For example, the speed controller 200 can be controlled by using proportional integral control (PI control) based on the speed error (ω err =ω * -ω) to calculate the d-axis current command I of the rotor 143 d* and q-axis current command I q* Here, the speed error is the speed command ω of the rotor 143 * and the difference between the speed value ω of the rotor 143.

[0135] The current controller 210 can compare the d-axis current command I output from the speed controller 200 with the current command I d* and q-axis current command I q* , the d-axis current value I output from the current converter 230 d and the q-axis current value I q、 and the q-axis current command compensation value I output from the AFC 250 qm* The current controller 210 may output a d-axis voltage command V based on the comparison result. d* and q-axis voltage command V q* Specifically, the current controller 210 can control the d-axis current command I by using proportional integral (PI) control. d* and the d-axis current value I d The difference between the d-axis voltage command V d* The current controller 210 can be based on the q-axis current command I q* , q-axis current value I q and q-axis current command compensation value I qm* The difference between the q-axis voltage command V q* .

[0136] The voltage converter 220 can convert the d-axis voltage command V outputted from the current controller 210 into d* and q-axis voltage command V q* Converted into three-phase voltage command V abc* (a phase voltage command, b phase voltage command, c phase voltage command), and the three-phase voltage command V abc*Output to inverter 144a. In this case, the control circuit 190 can use the PWM generator to generate the three-phase voltage command V abc* A PWM control signal is generated and may be output to the inverter 144 a .

[0137] The current converter 230 can convert the three-phase current value I detected by the current sensor 181 into abc Converted to d-axis current value I d and the q-axis current value I q , and can be output to the current controller 210.

[0138] The position calculator 240 may convert the speed value ω detected by the speed sensor 182 into a position value θ of the rotor 143. For example, the position calculator 240 may be implemented as an integrator.

[0139] The AFC 250 may be connected in parallel between an input node of the speed controller 200 and an input node of the current controller 210 .

[0140] The AFC 250 may receive a speed error value (ω err =ω * -ω) and the position value θ of the rotor 143.

[0141] The AFC 250 may be configured to calculate the speed error value (ω) of the rotor 143 based on the speed error value (ω err =ω * -ω) and the position value θ of the rotor 143 to output the q-axis current command value I for compensating q* The q-axis current command compensation value I qm* .

[0142] The AFC 250 can be configured based on the position value θ of the rotor 143 and the speed error value (ω) of the rotor 143 obtained by the bandpass filter. err =ω * -ω) filter to obtain the m-order harmonic component to be output to offset the current command value I q* The q-axis current command compensation value I of the m-order harmonic component in qm* In this case, m can be a natural number. AFC 250 can set the q-axis current command compensation value I qm* Output to the input node of the current controller 210 to compensate for the q-axis current command value I q* .

[0143] Figure 6 is a flowchart illustrating a method for controlling a washing machine according to an embodiment.

[0144] refer to Figure 6, the control circuit 190 can detect the speed of the motor 141 ( 300 ).

[0145] The control circuit 190 can detect the speed of the motor 141 through the speed sensor 182. At the same time, the control circuit 190 can detect the speed of the motor 141 through the current sensor 181 instead of the speed sensor 182. In this case, the control circuit 190 can detect the three-phase current value I detected by the current sensor 181. abc Converted to d-axis current value I d and the q-axis current value I q and can be based on the d-axis current value I d and the q-axis current value I q To identify the speed of the motor 141. The control circuit 190 can use the d-axis current value I of the motor 141 d and the q-axis current value I q , the speed of the motor 141 is estimated based on the motor modeling equation. For example, the speed and position of the motor 141 can be identified using sensorless vector control.

[0146] Control circuit 190 may determine a speed error value of motor 141 based on the speed command of motor 141 and the motor speed value detected by speed sensor 182 ( 302 ).

[0147] The control circuit 190 can generate a speed command ω according to the speed of the rotor 143. * and the speed value ω of the rotor 143 to determine the speed error value (ω err =ω * -ω).

[0148] The control circuit 190 may filter the speed error value of the motor 141 through a bandpass filter to obtain a preset m-order harmonic component (m is a natural number) ( 304 ).

[0149] The control circuit 190 may compensate the q-axis current command value of the motor 141 based on the filtered m-order harmonic component and the position information θ of the rotor 143 ( 306 ).

[0150] The control circuit 190 may drive the motor 141 based on the compensated q-axis current command value ( 308 ).

[0151] In the prior art, cogging torque occurs due to the magnetic interaction between stator 142 and rotor 143 of motor 141. This cogging torque generates torque fluctuations in the form of specific harmonic components, resulting in motor torque fluctuations and motor noise. Furthermore, when the noise coincides with the natural resonant frequency of the surrounding structure connected to motor 141, the motor noise is greatly amplified.

[0152] In an embodiment, the control circuit 190 can filter the speed error value of the rotor 143 using a bandpass filter to obtain a harmonic component of a specific order, can compensate the q-axis current command value of the motor 141 based on the filtered harmonic component of the specific order and the position information θ of the rotor 143, and can drive the motor based on the compensated q-axis current command value, thereby canceling the harmonic component of the specific order that occurs due to the cogging torque of the motor 141 and is included in the q-axis current command value of the motor. Therefore, the motor noise can be reduced, and the amplification of the motor noise that occurs when the noise coincides with the natural resonant frequency of the surrounding structure connected to the motor can be reduced.

[0153] Figure 7 An example of an operation cycle of the washing machine according to the embodiment is shown.

[0154] refer to Figure 7 , the washing machine 100 may sequentially perform a washing process 400 , a rinsing process 410 , and a spin-drying process 420 according to a user input.

[0155] The laundry may be washed through the washing process 400. Specifically, foreign matter attached to the laundry may be separated by a chemical action of a detergent and / or a mechanical action (eg, falling).

[0156] The washing process 400 may include laundry measurement 401 for measuring the amount of laundry, water supply 402 for supplying water to the tub 120, washing 403 for washing the laundry by rotating the drum 130 at a low speed, drainage 404 for draining the water contained in the tub 120, and intermediate spin drying 405 for separating water from the laundry by rotating the drum 130 at a high speed.

[0157] For washing 403, the control circuit 190 may control the driver 140 to rotate the motor 141 in a forward direction (e.g., clockwise) or a reverse direction (e.g., counterclockwise). As the drum 130 rotates, the laundry falls from the upper side of the drum 130 to the lower side, so that the laundry can be washed by falling.

[0158] For the intermediate spin drying 405, the control circuit 190 may control the driver 140 to rotate the motor 141 at high speed. By the high-speed rotation of the drum 130, water may be separated from the laundry contained in the drum 130 and thus discharged to the outside of the washing machine 100.

[0159] The clothes may be rinsed through the rinsing process 410. Specifically, detergent or foreign matter remaining on the clothes may be washed away with water.

[0160] The rinsing process 410 may include water supply 411 for supplying water to the tub 120, rinsing 412 for rinsing clothes by driving the drum 130, draining 413 for draining the water contained in the tub 120, and intermediate spin drying 414 for separating water from clothes by driving the drum 130.

[0161] The water supply 411, drainage 413, and intermediate spin drying 414 of the rinsing process 410 may be respectively the same as the water supply 402, drainage 404, and intermediate spin drying 405 of the washing process 400. During the rinsing process 410, the water supply 411, rinsing 412, drainage 413, and intermediate spin drying 414 may be performed once or several times.

[0162] The laundry may be dehydrated through the spin drying process 420. Specifically, water may be separated from the laundry by the high-speed rotation of the drum 130, and the separated water may be discharged to the outside of the washing machine 100.

[0163] The spin drying process 420 may include a final spin drying 421 in which the drum 130 is rotated at a high speed to separate water from the laundry. Due to the final spin drying 421, the final intermediate spin drying 414 of the rinsing process 410 may be omitted.

[0164] For the final spin drying 421, the control circuit 190 may control the driver 140 to rotate the motor 141 at high speed. By the high-speed rotation of the drum 130, water may be separated from the laundry contained in the drum 130 and discharged to the outside of the washing machine 100. In addition, the rotation speed of the motor 141 may be gradually increased.

[0165] Since the operation of the washing machine 100 ends with the final spin-drying 421 , the operation time of the final spin-drying 421 may be longer than the operation times of the intermediate spin-drying 405 and 414 .

[0166] The washing machine 100 may perform a washing process 400, a rinsing process 410, and a spin drying process 420 to wash clothes. Specifically, during the intermediate spin drying 405 and 414 and the final spin drying 421, the washing machine 100 may increase the rotation speed of the motor 141, which rotates the drum 130 in a stepwise manner.

[0167] The spin drying process described throughout this specification may refer to the intermediate spin drying 405 performed in the washing process 400, the intermediate spin drying 414 performed in the rinsing process 410, and the final spin drying 421 performed in the spin drying process 420. However, hereinafter, for ease of description, it is assumed that the spin drying process is the final spin drying 421 of the spin drying process 420 performed after the rinsing process 410.

[0168] According to an embodiment, washing machine 100 may filter the speed error value of rotor 143 using a bandpass filter to obtain a preset m-order harmonic component (m is a natural number) during a spin-drying process. The q-axis current command value of motor 141 may be compensated based on position information θ of rotor 143 and the filtered m-order harmonic component, and the motor may be driven based on the compensated q-axis current command value. In this case, washing machine 100 may compensate the q-axis current command value of motor 141 in response to the speed of rotor 143 being within a preset speed range during the spin-drying process.

[0169] Figure 8 An AFC of a control circuit of a washing machine according to an embodiment is shown.

[0170] refer to Figure 8 The AFC 250 may be connected in parallel between the input node 201 of the speed controller 200 and the input node 211 of the current controller 210, and may compensate for the q-axis current command value I output from the speed controller 200 to the current controller 210. q* .

[0171] The AFC 250 can be configured based on the position value θ of the rotor 143 and the speed error value ω of the rotor 143 obtained by the bandpass filter. err The m-order harmonic component obtained by filtering is output to offset the q-axis current command value I q* The q-axis current command compensation value I of the m-order harmonic component included in qm* .

[0172] The AFC 250 may include a bandpass filter 251 , an AFC gainer 252 , a first multiplier 253 , a first integrator 254 , a second multiplier 255 , a third multiplier 256 , a second integrator 257 , a fourth multiplier 258 , and an adder 259 .

[0173] The bandpass filter 251 can obtain the speed error value ω of the rotor 143 from the err The preset m-order harmonic component is obtained by filtering. For example, the output of the bandpass filter 251 can be BPF (ω err Here, m can be a natural number. For example, m can be a multiple of 12.

[0174] The AFC gain controller 252 may apply a preset gain value (-g) to the m-order harmonic component filtered by the bandpass filter 251 and may output the applied value. In this case, the AFC gain g may be a value corresponding to the number of slots of the motor 141. For example, the output of the AFC gain controller 252 may be ω errmth (ω errmth =BPF(ω err )*(-g)).

[0175] The first multiplier 253 may multiply the output of the AFC gain device 252 by the m-order cosine (mθ) of the position θ relative to the rotor 143 and may output the multiplied value. The output of the first multiplier 253 may be the BPF (ω err )*(-g)*cos(mθ).

[0176] The first integrator 254 may integrate the output of the first multiplier 253 and output an integrated value. The output of the first integrator 254 may be β m (β m =∫(ω errmth *cos(mθ)). β m It can be an adaptive parameter of AFC.

[0177] The second multiplier 255 may multiply the m-order cosine (mθ) by the output of the first integrator 254 and output the multiplied value. The output of the second multiplier 255 may be I q β m (I q β m =β m *cos(mθ)).

[0178] The third multiplier 256 may multiply the output of the AFC gain device 252 by the m-order sin(mθ) of the position θ relative to the rotor 143 and output the multiplied value. The output of the third multiplier 256 may be the BPF(ω err )*(-g)*sin(mθ).

[0179] The second integrator 257 may integrate the output of the third multiplier 256 and output an integrated value. The output of the second integrator 257 may be γ m (γ m =∫(ω errmth *sin(mθ)) γ m It can be an adaptive parameter of AFC.

[0180] The fourth multiplier 258 may multiply the m-order sin(mθ) by the output of the second integrator 257 and output the multiplied value. The output of the fourth multiplier 258 may be I q γ m (I q γ m =γ m *sin(mθ)).

[0181] The adder 259 may add the output of the second multiplier 255 and the output of the fourth multiplier 258 and output the summed value. The output of the adder 259 may be I qm*((I qm* =I q β m +I q γ m ).

[0182] The adder 259 can output I to the input node 211 of the current controller 210. qm* .

[0183] I output by AFC 250 qm* It can be used to compensate the q-axis current command value I q* The q-axis current command compensation value of q-axis current command compensation value I qm* Can offset the q-axis current command value I q* The m-th order harmonic component in .

[0184] q-axis current command compensation value I qm* It can be a harmonic current value.

[0185] q-axis current command compensation value I qm* It can be a harmonic current value used to generate a reaction harmonic torque relative to the target harmonic torque. qm* It can be a harmonic current value used to generate a reaction harmonic torque that is equal to but opposite in direction to the target harmonic torque.

[0186] q-axis current command compensation value I qm* It may be a harmonic current value for canceling the m-th order harmonic torque of the motor 141 .

[0187] q-axis current command compensation value I qm* It can be a harmonic current value for offsetting the harmonic torque of the cogging torque of the motor 141. The q-axis current command compensation value I qm* It may be a harmonic current value of the m-th order harmonic torque for canceling the cogging torque of the motor 141 .

[0188] In response to the AFC 250 setting the q-axis current command compensation value I qm* Output to the input node 211 of the current controller 210, the current controller 210 can be based on the q-axis current command I q* To output the q-axis voltage command value V q*， Among them, the q-axis current command I q* The q-axis current command I output from the speed controller 200 is obtained as follows: q* Subtract the q-axis current command compensation value I from qm* and the q-axis current value I q In this case, the control circuit 190 may set the d-axis current command value I to 1, which does not contribute to the torque generation of the motor. d*Fixed to 0, and can only control the q-axis current command I q* In this case, the current controller 210 may be based on the d-axis current value I d To output the d-axis voltage command value V d* .

[0189] The q-axis current command I output from the speed controller 200 to the current controller 210 q* Including certain harmonic components due to cogging torque. Therefore, the q-axis current command I q* It can be a waveform including harmonic components instead of a sine waveform. Therefore, in the q-axis current command I q* In the case of driving the motor 141, motor noise may occur. However, according to the present disclosure, the q-axis current command value I q* The q-axis current command compensation value I can be used qm* To compensate, thereby offsetting the q-axis current command value I q* The harmonic components of a specific order included in the q-axis current command I are kept in the form of a sine waveform. q* Therefore, the motor noise can be reduced.

[0190] The number of slots in the stator 142 of the motor 141 of the washing machine 100 is highly correlated with the harmonic components of the cogging torque generated by the motor 141. A change in the number of slots can affect the form of the harmonic components of the cogging torque. For example, when the number of slots is 12, a 12th-order harmonic component can clearly appear among the harmonic components. When the number of slots is 24, a 24th-order harmonic component can clearly appear. When the number of slots is 36, a 36th-order harmonic component can clearly appear. When the number of slots is 48, a 48th-order harmonic component can clearly appear.

[0191] For example, in Figure 3 In the illustrated motor 141 , since the number of slots of the stator 142 is 36, the 36th-order harmonic component clearly appears between the harmonic components of the cogging torque, and the 36th-order harmonic component may mainly affect the motor noise.

[0192] Figure 9 An example of AFC of a control circuit of a washing machine according to an embodiment is shown.

[0193] refer to Figure 9 , AFC 250 can output the q-axis current command compensation value I used to offset the 36th order harmonic component qm* .

[0194] The output of the first multiplier 253 may be BPF(ω err )*(-g)*cos(36θ).

[0195] The output of the first integrator 254 may be β 36th (β 36th =∫(ω err36th *cos(36θ)).

[0196] The output of the second multiplier 255 can be I q β 36th (I q β 36th =β 36th *cos(36θ)).

[0197] The output of the third multiplier 256 may be BPF(ω err )*(-g)*sin(36θ).

[0198] The output of the second integrator 257 may be γ 36th (γ 36th =∫(ω err36th *sin(36θ)).

[0199] The output of the fourth multiplier 258 may be I q γ 36th (I q γ 36th =γ 36th *sin(36θ)).

[0200] The output of adder 259 can be I qm* ((I qm* =I q β 36th +I q γ 36th ).

[0201] The q-axis current command compensation value I output by AFC 250 qm* Can offset the q-axis current command value I q* The 36th harmonic component included.

[0202] Figure 10 is a flowchart illustrating an operation of canceling a 36th-order harmonic component included in a q-axis current command of a motor in a washing machine according to an embodiment.

[0203] refer to Figure 10 , the control circuit 190 may start the spin drying process according to the spin drying profile (500). To perform the spin drying process, the control circuit 190 may rotate the drum 130 according to the spin drying profile. The spin drying profile may be a pre-stored spin drying profile, or may be a spin drying profile in which the stored spin drying profile is changed based on factors such as the load of laundry.

[0204] The control circuit 190 may detect the speed of the motor 141 through the speed sensor 182 during the spin drying process (502).

[0205] The control circuit 190 may identify whether the motor speed is in the resonant band (504).

[0206] The resonant band can be the resonant band of the washing machine. The resonant band can be the resonant band of the motor or the resonant band of the surrounding structure to which the motor 141 is connected (e.g., the drum 130, tub 120, etc.). Since the motor 141 is mounted on the tub 120, the overlap of the natural frequency of the tub 120 and the rotational frequency of the motor 141 can significantly increase the noise. Therefore, it is necessary to determine whether the motor speed is within the resonant band. The resonant band value can be a preset speed value or a preset speed range value. The resonant band value can be 500 rpm or a value within the range of 400 to 600 rpm. For example, when the number of motor slots is 36, motor noise caused by the 36th-order harmonic component occurs during the spin drying process. In this case, when the motor noise coincides with the resonant frequency of the tub 120 at approximately 500 rpm, the motor noise can be greatly amplified.

[0207] In response to the motor speed being in the resonant band (Yes in Operation 504 ), the control circuit 190 may determine a speed error value ω of the motor 141. err (506).

[0208] The control circuit 190 can generate a speed command ω according to the speed of the rotor 143 of the motor 141. * and the speed value ω of the rotor 143 to determine the speed error value (ω err =ω * -ω).

[0209] The control circuit 190 can determine the 36th order harmonic component ω filtered by the bandpass filter 251 err36th , the bandpass filter 251 is used to filter the speed error value ω err The 36th harmonic component (508) is obtained by filtering.

[0210] The control circuit 190 can convert the value ((BPF(ω)) obtained by the following method into err) *(-g)) is determined as the 36th order harmonic component ω obtained by filtering by the bandpass filter 251 err36th : Apply the gain value (-g) of the AFC gain unit 252 to the speed error value ω err The 36th order harmonic component (BPF (ω) of the bandpass filter 251 err） )).

[0211] The control circuit 190 can be based on the 36th order harmonic component ω filtered by the bandpass filter 251.err36th and the position θ of the rotor 143 to determine β as the 36th order adaptive parameter of the AFC 250 36th and γ 36th (510).

[0212] The control circuit 190 can 36th Determined as ∫(ω err36th *cos(36θ). The control circuit 190 can 36th Determined as ∫(ω err36th *sin(36θ)).

[0213] The control circuit 190 may determine the 36th Current compensation value I q β 36th and as based on γ 36th Current compensation value I q γ 36th (512).

[0214] The control circuit 190 can q β 36th Determined as β 36th *cos(36θ). The control circuit 190 can q γ 36th Determined as γ 36th *sin(36θ).

[0215] The control circuit 190 can be based on I q β 36th and I q γ 36th To determine the q-axis current command compensation value I qm* (514).

[0216] The control circuit 190 can be controlled by I q β 36th and I q γ 36th Add to determine the q-axis current command compensation value I qm*， I qm* =I q β 36th +I q γ 36th .

[0217] The control circuit 190 can generate a q-axis current command compensation value I qm* to compensate the q-axis current command value (516).

[0218] The control circuit 190 may drive the motor 141 based on the compensated q-axis current command value ( 518 ).

[0219] In response to the motor speed not being in the resonant band (No in operation 504 ), the control circuit 190 may set the q-axis current command compensation value I qm* It is determined to be 0 (520). Therefore, the control circuit 190 can drive the motor 141 based on the uncompensated q-axis current command value.

[0220] Therefore, the control circuit 190 can use the q-axis current command compensation value I in the resonant frequency band qm* To offset the q-axis current command value I q* The 36th harmonic component included in the output can reduce motor noise.

[0221] Figure 11 The change of the 36th order noise component in the AFC in the washing machine according to the embodiment in the activated state and the deactivated state is shown.

[0222] Figure 11 The results of a Fast Fourier Transform (FFT) analysis of measured motor noise are shown, depending on whether the AFC 250 is operated at 500 rpm (36 motor slots, 60 Hz). The FFT analysis results show changes in the 36th order noise component between the activated and deactivated states of the AFC 250.

[0223] In a case where the AFC 250 is deactivated (AFC OFF), a 36th-order noise component is 44.8 dBA at 300 Hz (500 rpm*36 slots / 60 Hz), which indicates a noise level when the AFC 250 does not operate.

[0224] However, with the AFC 250 activated (AFC on), the 36th order noise component is reduced to 30.0 dBA, lower than 44.8 dBA, which indicates that when the AFC 250 operates, the 36th order noise level is lower than the previous state.

[0225] Therefore, depending on whether the AFC 250 is activated, the 36th order noise component is reduced by 14.8 dBA, indicating that the operation of the AFC 250 is effective in reducing the 36th order noise.

[0226] Figure 12 is a control block diagram illustrating a control circuit of a washing machine according to another embodiment.

[0227] refer to Figure 12 , the AFC 250 may include a plurality of AFCs, namely 250a to 250n.

[0228] In the case where there are a plurality of m-order harmonic components to be canceled, a plurality of AFCs 250 equal to the number of harmonic components of the target order may be connected in parallel.

[0229] The control circuit 190 may activate or deactivate all of the AFCs in the plurality of AFCs ( 250 a to 250 n ).

[0230] Unnecessarily activating too many AFCs 250 may reduce motor control stability. Therefore, the control circuit 190 may activate some of the multiple AFCs (250a to 250n) and may deactivate other AFCs.

[0231] The control circuit 190 may activate only one of the plurality of AFCs (250a to 250n) and may deactivate all other AFCs. Depending on the m-th order harmonic component to be canceled, the corresponding AFC may be selected and activated.

[0232] In a washing machine 100 having 36 motor slots, the 36th-order harmonic component is of interest. Therefore, to cancel only the 36th-order harmonic component, only the AFC corresponding to the 36th-order harmonic component can be activated among the multiple AFCs (250a to 250n), and the other AFCs can be deactivated. The activated AFC can extract only the 36th-order harmonic component from the speed error value by applying a bandpass filter, thereby preventing a decrease in motor control stability and reducing motor noise.

[0233] The control circuit 190 can activate the AFC 250 only in the resonance band where the 36th-order noise occurs, thereby preventing the motor control stability from being affected in other frequency bands. For example, the AFC 250 can be activated only in the range of 400 to 600 rpm and can be deactivated in the remaining ranges.

[0234] Figure 13 is a flowchart illustrating an operation of selecting and activating one of a plurality of AFCs in a washing machine according to another embodiment.

[0235] refer to Figure 13 , the control circuit 190 may start the spin drying process according to the spin drying profile ( 600 ). To perform the spin drying process, the control circuit 190 may rotate the drum 130 according to the spin drying profile.

[0236] The control circuit 190 may detect the speed of the motor 141 through the speed sensor 182 during the spin drying process ( 602 ).

[0237] The control circuit 190 may identify whether the motor speed is in the resonant band ( 604 ).

[0238] In response to the motor speed being in the resonant frequency band (YES in operation 604 ), the control circuit 190 may identify a target-order harmonic component (a harmonic component of a target order), which is a harmonic component of an order to be canceled ( 606 ).

[0239] The control circuit 190 can identify the number of slots of the motor 141 based on information about the motor 141 in the washing machine 100, and can identify the target order harmonic component based on the number of slots of the motor. For example, when the number of slots of the motor is 36, the target order harmonic component can be identified as the 36th order harmonic component.

[0240] The control circuit 190 may select at least one AFC ( 608 ) from among the plurality of AFCs ( 250 a to 250 n ).

[0241] The control circuit 190 may select at least one AFC from the plurality of AFCs (250a to 250n) based on the target-order harmonic component. For example, if the target-order harmonic component is a 36th-order harmonic component, an AFC for canceling the 36th-order harmonic component may be selected from the plurality of AFCs (250a to 250n).

[0242] The control circuit 190 may activate the selected AFCs and deactivate the remaining AFCs ( 610 ).

[0243] In response to the motor speed not being in the resonant band (NO in operation 604 ), the control circuit 190 may deactivate all AFCs in the plurality of AFCs ( 250 a to 250 n ) ( 612 ).

[0244] The control circuit 190 can activate the AFC 250 only in the resonant frequency band where 36th-order noise occurs, thereby preventing the motor control stability from being affected in other frequency bands. For example, the AFC 250 can be activated only in the range of 400 to 600 rpm and can be deactivated in the remaining ranges.

[0245] According to the present disclosure, harmonic components generated in a motor can be offset, thereby reducing motor noise.

[0246] According to the present disclosure, motor noise can be reduced by canceling specific harmonic components generated by cogging torque of a motor, and motor noise amplified when the motor noise coincides with a natural resonant frequency of a surrounding structure connected to the motor can be reduced.

[0247] According to an embodiment of the present disclosure, a washing machine may include: a drum 130, configured to rotate inside a tub 120; a motor 141, including a stator 142 and a rotor 143, and configured to rotate the drum 130; an inverter circuit 144, connected to the motor 141; and at least one processor 191, configured to: compensate for a q-axis current command value of the motor 141 based on an m-order harmonic component (m is a natural number) and the position of the rotor 143, and control the inverter circuit 144 based on the compensated q-axis current command value to drive the motor 141, wherein the m-order harmonic component is filtered from a speed error value of the rotor 143 by a bandpass filter.

[0248] The at least one processor may be configured to determine a q-axis current command compensation value for canceling an m-order harmonic component included in a q-axis current command value of the motor, and compensate the q-axis current command value of the motor based on the q-axis current command compensation value.

[0249] The at least one processor may be configured to compensate a q-axis current command value of the motor in response to a speed of the rotor being within a preset speed range during the spin-drying process.

[0250] m can be a multiple of 12.

[0251] m can be 36.

[0252] At least one processor may include: a speed controller 200 configured to output a q-axis current command value I based on the speed error value of the rotor. q* and the d-axis current command value I d* Current controller 210, is configured to be based on the q-axis current command value I output from the speed controller q* and the d-axis current command value I d* To output the q-axis voltage command value V q* and the d-axis voltage command value V d* and an active feedforward controller (AFC) 250), configured to output an m-order harmonic component for canceling the current command value I included in the q-axis current command value based on the rotor position and the speed error value filtered from the rotor by the bandpass filter. q* The q-axis current command compensation value of the m-order harmonic component in .

[0253] The AFC may be configured to be connected in parallel between an input node of the speed controller and an input node of the current controller.

[0254] The AFC may include: a bandpass filter configured to filter a speed error value of the rotor to obtain a preset m-order harmonic component; an AFC gainer 252 configured to apply a preset gain value to the m-order harmonic component filtered by the bandpass filter; a first multiplier 253 configured to multiply an output of the AFC gainer by an m-order cosine (mθ) relative to a position θ of the rotor; a first integrator 254 configured to integrate the output of the first multiplier; a second multiplier 255 configured to multiply the output of the first integrator by an m-order cosine (mθ); a third multiplier 256 configured to multiply the output of the AFC gainer by an m-order sin (mθ) relative to a rotational position θ of the rotor; a second integrator 257 configured to integrate the output of the third multiplier; a fourth multiplier 258 configured to multiply the output of the second integrator by an m-order sin (mθ); and an adder 259 configured to add the output of the second multiplier and the output of the fourth multiplier.

[0255] The at least one processor may be configured to activate the AFC in response to a speed of the rotor being within a preset speed range during the spin drying process.

[0256] The preset speed range may include a resonance band of the washing machine.

[0257] The at least one processor may include a speed controller configured to output a q-axis current command value I based on a speed error value of the rotor. q* and the d-axis current command value I d* ; A current controller configured to output a q-axis current command value I based on the speed controller q* and the d-axis current command value I d* To output the q-axis voltage command value V q* and the d-axis voltage command value V d* and a plurality of AFCs configured to output an m-order harmonic component for canceling the current command value I included in the q-axis current command value based on the rotor position and the speed error value filtered from the rotor by a bandpass filter; q* A plurality of AFCs may be configured to be connected in parallel between an input node of the speed controller and an input node of the current controller.

[0258] The at least one processor may be configured to identify a target order harmonic component based on a number of slots in the rotor, select at least one AFC from a plurality of AFCs based on the target order harmonic component, and activate the at least one selected AFC and deactivate the remaining AFCs.

[0259] The at least one processor may be configured to activate the selected AFC in response to the speed of the rotor being within a resonance band of the washing machine or the speed of the rotor being within a preset speed range during the spin-drying process.

[0260] According to an embodiment of the present disclosure, a method for controlling a washing machine, which includes: a drum configured to rotate inside a tub; and a motor including a stator and a rotor and configured to rotate the drum, the method may include: filtering a speed error value of the rotor by a bandpass filter to obtain a preset m-order harmonic component (m is a natural number); compensating a q-axis current command value of the motor based on the filtered m-order harmonic component and the position of the rotor; and driving the motor based on the compensated q-axis current command value.

[0261] Compensating the q-axis current command value of the motor may include determining a q-axis current command compensation value for canceling an m-order harmonic component included in the q-axis current command value of the motor, and compensating the q-axis current command value of the motor based on the q-axis current command compensation value.

[0262] Compensating the q-axis current command value of the motor may include compensating the q-axis current command value of the motor in response to a speed of the rotor being within a preset speed range during the spin-drying process.

[0263] When the preset m-th order harmonic component is obtained by filtering, m may be a multiple of 12.

[0264] A washing machine may include an automatic fuel cell (AFC) configured to output a q-axis current command compensation value for canceling the m-order harmonic component based on a filtered m-order harmonic component and a position of a rotor. Compensating the q-axis current command value of the motor may include activating the AFC in response to a rotor speed within a preset speed range during a spin-drying process.

[0265] Compensating the q-axis current command value of the motor may include activating the AFC in response to a speed of the rotor being within a resonance band of the washing machine during the spin-drying process.

[0266] A washing machine may include a plurality of automatic frequency converters (AFCs) configured to output a q-axis current command compensation value for canceling an m-order harmonic component based on a rotor position and an m-order harmonic component filtered from a speed error value of the rotor by a bandpass filter. Compensating the q-axis current command value of the motor may include identifying a target-order harmonic component based on the number of slots in the rotor, selecting at least one AFC from the plurality of AFCs based on the target-order harmonic component, and activating the at least one selected AFC while deactivating the remaining AFCs.

[0267] The disclosed embodiments may be implemented in the form of a recording medium storing computer-executable instructions. These instructions may be stored in the form of program codes, and when executed by a processor, these instructions may create a program module for performing the operations of the disclosed embodiments.

[0268] The machine-readable recording medium may be provided in the form of a non-transitory storage medium. The term "non-transitory storage medium" may refer to a tangible device that does not include signals (e.g., electromagnetic waves) and may not distinguish between semi-permanent and temporary storage of data in the storage medium. For example, the non-transitory storage medium may include a buffer that temporarily stores data.

[0269] The methods according to various embodiments of the present disclosure may be provided in a computer program product. A computer program product may be a commercial product that can be traded between a seller and a buyer. The computer program product may be distributed in the form of a storage medium (e.g., a compact disc read-only memory (CD-ROM)), through an app store (e.g., Play Store™), directly between two user devices (e.g., smartphones), or online (e.g., by downloading or uploading). In the case of online distribution, at least a portion of the computer program product (e.g., a downloadable application) may be at least temporarily stored or arbitrarily created in a storage medium readable by a device (e.g., a manufacturer's server, an app store's server, or a relay server).

[0270] While the disclosure has been shown and described in conjunction with particular embodiments, it will be appreciated by those skilled in the art that changes and modifications may be made in these embodiments without departing from the principles and scope of the disclosure, which is defined by the claims and their equivalents.

Claims

1. A washing machine comprising: a drum configured to rotate within the tub; a motor including a stator and a rotor and configured to rotate the drum; an inverter circuit connected to the motor; as well as At least one processor is configured to compensate a q-axis current command value of the motor based on an m-th order harmonic component and a position of the rotor, and control the inverter circuit to drive the motor based on the compensated q-axis current command value, wherein m is a natural number and the m-th order harmonic component is filtered from a speed error value of the rotor by a bandpass filter.

2. The washing machine according to claim 1, wherein The at least one processor is configured to determine a q-axis current command compensation value for canceling an m-order harmonic component included in a q-axis current command value of the motor, and compensate the q-axis current command value of the motor based on the q-axis current command compensation value.

3. The washing machine according to claim 2, wherein: The at least one processor is configured to compensate a q-axis current command value of the motor in response to a speed of the rotor being within a preset speed range during a spin-drying process.

4. The washing machine according to claim 1, wherein m is a multiple of 12.

5. The washing machine according to claim 4, wherein m is 36. The washing machine according to claim 1 , wherein: The at least one processor comprises: A speed controller is configured to output a q-axis current command value I based on the speed error value of the rotor. q* and the d-axis current command value I d* ; The current controller is configured to: based on the q-axis current command value I output from the speed controller q* and the d-axis current command value I d* To output the q-axis voltage command value V q* and the d-axis voltage command value V d* ;as well as The active feedforward controller AFC is configured to output a current command value I for canceling the q-axis current command value I based on the position of the rotor and the m-th order harmonic component obtained by filtering the speed error value of the rotor by the bandpass filter. q* The q-axis current command compensation value of the m-order harmonic component included in .

7. The washing machine according to claim 6, wherein: The AFC is connected in parallel between an input node of the speed controller and an input node of the current controller.

8. The washing machine according to claim 6, wherein The AFC includes: a bandpass filter configured to filter the speed error value of the rotor to obtain a preset m-th order harmonic component, An AFC gainer is configured to apply a preset gain value to the m-th order harmonic component filtered by the bandpass filter, a first multiplier configured to multiply the output of the AFC gainer by an m-order cosine (mθ) relative to a position θ of the rotor, a first integrator configured to integrate the output of the first multiplier, a second multiplier configured to multiply the output of the first integrator by m-th order cos(mθ), a third multiplier configured to multiply the output of the AFC gainer by an m-th order sin(mθ) relative to a rotational position θ of the rotor, a second integrator configured to integrate the output of the third multiplier, a fourth multiplier configured to multiply the output of the second integrator by m-order sin(mθ), and An adder is configured to add the output of the second multiplier and the output of the fourth multiplier.

9. The washing machine according to claim 6, wherein: The at least one processor is configured to activate the AFC in response to a speed of the rotor being within a preset speed range during a spin drying process.

10. The washing machine according to claim 9, wherein The preset speed range includes a resonance band of the washing machine.

11. The washing machine according to claim 1, wherein The at least one processor comprises: A speed controller configured to output a q-axis current command value I based on the speed error value of the rotor q* and the d-axis current command value I d* ; A current controller configured to generate a q-axis current command value I output from the speed controller based on the q-axis current command value I q* and the d-axis current command value I d* To output the q-axis voltage command value V q* and the d-axis voltage command value V d* ;as well as A plurality of AFCs are configured to output a current command value I for canceling the q-axis current command value I based on the position of the rotor and the m-th order harmonic component filtered from the speed error value of the rotor by the bandpass filter. q* The q-axis current command compensation value of the m-order harmonic component included in Each of the plurality of AFCs is connected in parallel between an input node of the speed controller and an input node of the current controller.

12. The washing machine according to claim 11, wherein The at least one processor is configured to: identifying harmonic components of a target order based on the number of slots in the rotor, selecting at least one AFC from the plurality of AFCs based on the harmonic components of the target order, and The selected at least one AFC is activated and the remaining AFCs are deactivated.

13. The washing machine according to claim 12, wherein: The at least one processor is configured to activate the selected AFC in response to a speed of the rotor being within a resonance band of the washing machine or a speed of the rotor being within a preset speed range during a spin drying process.

14. A method for controlling a washing machine, the washing machine comprising a drum and a motor, the drum being configured to rotate inside a tub, the motor comprising a stator and a rotor and configured to rotate the drum, the method comprising: filtering the speed error value of the rotor using a bandpass filter to obtain a preset m-th order harmonic component, where m is a natural number; compensating a q-axis current command value of the motor based on the filtered m-order harmonic component and the position of the rotor; as well as The motor is driven based on the compensated q-axis current command value.

15. The method according to claim 14, wherein Compensating the q-axis current command value of the motor includes determining a q-axis current command compensation value for canceling an m-order harmonic component included in the q-axis current command value of the motor, and compensating the q-axis current command value of the motor based on the q-axis current command compensation value.

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