Washing machine and control method for same

Abstract

This washing machine comprises: a drum rotatably provided inside a tub; a motor, which includes a stator and a rotor and rotates the drum; an inverter circuit connected to the motor; and at least one processor for compensating for a q-axis current command value of the motor on the basis of the position of the rotor and an m-th (m is a natural number) harmonic component filtered by a band pass filter from the speed error value of the rotor, and controlling the inverter circuit so as to drive the motor on the basis of the compensated q-axis current command value.

Description

Washing machine and its control method

[0001] The disclosed invention relates to a washing machine and a control method thereof, and more particularly, to a washing machine including a motor for rotating a drum and a control method thereof.

[0002] A washing machine includes a tub, a drum rotatably installed within the tub, and a motor for rotating the drum, and can wash laundry by rotating the drum containing laundry within the tub. The washing machine can perform a washing cycle for washing laundry, a rinsing cycle for rinsing washed laundry, and a spin-drying cycle for spin-drying laundry.

[0003] The dehydration cycle can separate the water absorbed in the laundry from the laundry by controlling the motor to rotate the drum containing the laundry at high speed.

[0004] Motors can experience cogging torque due to the magnetic interaction between the rotor and stator. Cogging torque generates torque ripple in the form of specific harmonic components, causing torque fluctuations in the motor.

[0005] Motor torque fluctuations can cause vibration and shock, generating motor noise. This noise is transmitted to surrounding structures connected to the motor, and can be significantly amplified when it interacts with the natural resonant frequency of the surrounding structures.

[0006] One aspect of the disclosed invention provides a washing machine and a control method thereof capable of reducing motor noise by canceling out harmonic components generated from the motor.

[0007] The technical problems to be achieved in this document are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present invention belongs from the description below.

[0008] According to one aspect of the disclosed invention, a washing machine may include: a drum rotatably provided inside a tub; a motor including a stator and a rotor and rotating the drum; an inverter circuit connected to the motor; and at least one processor for controlling the inverter circuit to compensate for a q-axis current command value of the motor based on an m-th harmonic component (m is a natural number) filtered by a bandpass filter from a speed error value of the rotor and a position of the rotor, and to drive the motor based on the compensated q-axis current command value.

[0009] A control method of a washing machine according to one aspect of the disclosed invention includes a control method of a washing machine including a drum rotatably provided inside a tub, and a motor including a stator and a rotor for rotating the drum, the method including: filtering a preset m-th harmonic component (m is a natural number) from a speed error value of the rotor through a bandpass filter; compensating a q-axis current command value of the motor based on the filtered m-th harmonic component and position information (θ) of the rotor; and driving the motor based on the compensated q-axis current command value.

[0010] Figure 1 illustrates the exterior of a washing machine according to one embodiment.

[0011] FIG. 2 illustrates a side cross-section of a washing machine according to one embodiment.

[0012] Figure 3 illustrates a motor of a washing machine according to one embodiment.

[0013] Figure 4 illustrates a control block diagram of a washing machine according to one embodiment.

[0014] FIG. 5 illustrates a control block diagram of a control circuit of a washing machine according to one embodiment.

[0015] Figure 6 is a flowchart showing a control method of a washing machine according to one embodiment.

[0016] Figure 7 illustrates an example of an operating cycle of a washing machine according to one embodiment.

[0017] FIG. 8 illustrates an active feedforward controller (AFC) of a control circuit in a washing machine according to one embodiment.

[0018] FIG. 9 illustrates an example of an active feedforward controller of a control circuit in a washing machine according to one embodiment.

[0019] Fig. 10 is a flowchart showing a process of canceling out a 36th harmonic component included in a q-axis current command of a motor in a washing machine according to one embodiment.

[0020] Fig. 11 shows the change in the 36th-order noise component when the active feedforward controller (AFC) is activated and deactivated in a washing machine according to one embodiment.

[0021] Fig. 12 illustrates a control block diagram of a control circuit of a washing machine according to another embodiment.

[0022] FIG. 13 is a flowchart illustrating a process of selecting and activating one of a plurality of active feedforward controllers (AFCs) in a washing machine according to another embodiment.

[0023] It should be understood that the various embodiments and terms used in this document are not intended to limit the technical features described in this document to specific embodiments, but rather to include various modifications, equivalents, or substitutes of the embodiments.

[0024] In connection with the description of the drawings, similar reference numerals may be used for similar or related components.

[0025] The singular form of a noun corresponding to an item may include one or more of said items, unless the relevant context clearly indicates otherwise.

[0026] In this document, each of the phrases "A or B", "at least one of A and B", "at least one of A or B", "A, B, or C", "at least one of A, B, and C", and "at least one of A, B, or C" may include any one of the items listed together in that phrase, or all possible combinations thereof.

[0027] The term "and / or" includes any combination of a plurality of related described elements or any one of a plurality of related described elements.

[0028] Terms such as "first," "second," or "first" or "second" may be used simply to distinguish one component from another and do not qualify the components in any other respect (e.g., importance or order).

[0029] When a component (e.g., a first component) is referred to as being "coupled" or "connected" to another component (e.g., a second component), with or without the terms "functionally" or "communicatively," it means that the component can be connected to the other component directly (e.g., wired), wirelessly, or through a third component.

[0030] The terms "include" or "have" are intended to specify the presence of a feature, number, step, operation, component, part or combination thereof described in this document, but do not preclude the presence or addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

[0031] When a component is said to be “connected,” “coupled,” “supported,” or “in contact with” another component, this includes not only cases where the components are directly connected, coupled, supported, or in contact, but also cases where the components are indirectly connected, coupled, supported, or in contact through a third component.

[0032] When we say that a component is "on" another component, this includes not only cases where the component is in contact with the other component, but also cases where there is another component between the two components.

[0033] Washing machines according to various embodiments can perform washing, rinsing, spin-drying, and drying processes. A washing machine is an example of a clothing treatment device, and the term "clothing treatment device" encompasses devices that wash clothing (laundry items, drying items), devices that dry clothing, and devices that can perform both washing and drying of clothing.

[0034] Washing machines according to various embodiments may include top-loading washing machines in which the laundry inlet for loading or removing laundry is provided facing upward, or front-loading washing machines in which the laundry inlet is provided facing forward. Washing machines according to various embodiments may include washing machines of other loading methods other than top-loading washing machines and front-loading washing machines.

[0035] In the case of a top-loading washing machine, laundry can be washed using a water current generated by a rotating body such as a pulsator. In the case of a front-loading washing machine, laundry can be washed by rotating the drum to repeatedly raise and lower the laundry. The front-loading washing machine may include a washing machine with a dryer that can dry the laundry contained inside the drum. The washing machine with a dryer 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 discharged from the drum. For example, the washing machine with a dryer may include a heat pump device. The washing machine according to various embodiments may include a washing machine with a washing method other than the washing method described above.

[0036] Washing machines according to various embodiments may include a housing that accommodates various components therein. The housing may be provided in the form of a box with a laundry inlet formed on one side.

[0037] A washing machine may include a door for opening and closing the laundry compartment. The door may be rotatably mounted to the housing by a hinge. At least a portion of the door may be transparent or translucent to allow the interior of the housing to be viewed.

[0038] A washing machine may include a tub provided within a housing to store wash water. The tub may be provided in a generally cylindrical shape with a tub opening formed on one side, and may be positioned within the housing such that the tub opening corresponds to a laundry inlet.

[0039] The tub may be connected to the housing by a damper. The damper can absorb vibrations generated when the drum rotates, thereby reducing the vibrations transmitted to the housing.

[0040] A washing machine may include a drum configured to accommodate laundry.

[0041] The drum may be positioned within the tub such that the drum opening provided on one side corresponds to the laundry inlet and the tub opening. Laundry may be sequentially passed through the laundry inlet, the tub opening, and the drum opening to be accommodated within the drum or taken out from the drum.

[0042] The drum rotates within the tub and can perform each of the washing, rinsing, and / or spin-drying operations. The cylindrical wall of the drum is formed with a number of perforations, allowing wash water stored in the tub to flow into or out of the drum.

[0043] A washing machine may include a drive configured to rotate a drum. The drive may include a drive motor and a rotating shaft for transmitting driving force generated by the drive motor to the drum. The rotating shaft may be connected to the drum by penetrating the tub.

[0044] The actuator can rotate the drum forward or backward to perform each operation according to the washing, rinsing, and / or dehydration, or drying cycle.

[0045] A washing machine may include a water supply unit configured to supply washing water to a tub. The water supply unit may include a water supply pipe and a water supply valve provided on the water supply pipe. The water supply pipe may be connected to an external water source. The water supply pipe may extend from the external water source to a detergent supply device and / or the tub. Washing water may be supplied to the tub via the detergent supply unit. Washing water may be supplied to the tub without passing through the detergent supply unit.

[0046] The water supply valve can open or close the water supply line in response to an electrical signal from the control circuit. The water supply valve can allow or block the supply of washing water to the tub from an external water source. The water supply valve may include, for example, a solenoid valve that opens and closes in response to an electrical signal.

[0047] A washing machine may include a detergent dispenser configured to supply detergent to a tub. The detergent dispenser may include a manual detergent dispenser that requires a user to dispense detergent for each wash cycle, and an automatic detergent dispenser that stores a large quantity of detergent and automatically dispenses a predetermined amount of detergent during a wash cycle. The detergent dispenser may include a detergent compartment for storing detergent. The detergent dispenser may be configured to supply detergent into the tub during a water supply process. Wash water supplied through a water supply pipe may be mixed with detergent via the detergent dispenser. Wash water mixed with detergent may be supplied into the tub. Detergent is used as a comprehensive term for pre-wash detergent, main wash detergent, fabric softener, bleach, etc., and the detergent compartment may be divided into a pre-wash detergent storage area, a main wash detergent storage area, a fabric softener storage area, and a bleach storage area.

[0048] A washing machine may include a drain configured to discharge wash water contained in a tub to the outside. The drain 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 wash water from the drain pipe to the outside of the housing.

[0049] The washing machine may include a control panel positioned on one side of the housing. The control panel may provide a user interface for a user to interact with the washing machine. The user interface may include at least one input interface and at least one output interface.

[0050] At least one input interface can convert sensory information received from a user into an electrical signal.

[0051] At least one input interface may include a power button, an operation button, a course selection dial (or a course selection button), and a wash / rinse / spin setting button. The at least one input interface may include, for example, a tact switch, a push 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.

[0052] At least one output interface can visually or audibly convey information related to the operation of the washing machine to the user.

[0053] For example, at least one output interface may transmit information related to the washing cycle and operating time of the washing machine, as well as washing / rinsing / spin settings to the user. Information related to the operation of the washing machine may be output via a screen, indicator, voice, etc. At least one output interface may include, for example, a liquid crystal display (LCD) panel, a light emitting diode (LED) panel, a speaker, etc.

[0054] The washing machine may include a communication module for communicating with external devices via wires and / or wirelessly.

[0055] The communication module may include at least one of a short-range communication module or a long-range communication module.

[0056] The communication module can transmit data to or receive data from external devices (e.g., a server, a user device, and / or a home appliance). For example, the communication module can establish communication with a server, a user device, and / or a home appliance, and transmit and receive various data.

[0057] To this end, the communication module may support the establishment of a direct (e.g., wired) communication channel or a wireless communication channel between external devices, and the performance of communication through the established communication channel. According to one 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). Any of these communication modules may communicate with the external device via a first network (e.g., a short-range communication network such as Bluetooth, wireless fidelity (WiFi) direct, or infrared data association (IrDA)) or a second network (e.g., a long-range communication network such as a legacy 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 may be integrated into a single component (e.g., a single chip) or implemented as multiple separate components (e.g., multiple chips).

[0058] The short-range wireless communication module may include, but is not limited to, a Bluetooth communication module, a BLE (Bluetooth Low Energy) communication module, a near field communication module, a WLAN (Wi-Fi) communication module, a Zigbee communication module, an infrared (IrDA, infrared Data Association) communication module, a WFD (Wi-Fi Direct) communication module, an UWB (ultrawideband) communication module, an Ant+ communication module, a microwave (uWave) communication module, etc.

[0059] The long-distance communication module may include a communication module that performs various types of long-distance communication and may include a mobile communication unit. The mobile communication unit transmits and receives wireless signals with at least one of a base station, an external terminal, and a server on a mobile communication network.

[0060] In one embodiment, the communication module can communicate with external devices such as a server, a user device, and other home appliances via a peripheral access point (AP). The access point (AP) can connect a local area network (LAN) to which the washing machine or the user device is connected to a wide area network (WAN) to which the server is connected. The washing machine or the user device can be connected to the server via the wide area network (WAN). The control circuit can control various components of the washing machine, such as a drive motor and a water inlet valve. The control circuit can control various components of the washing machine to perform at least one cycle, including water supply, washing, rinsing, and / or spin-drying, based on user input. For example, the control circuit can control the drive motor to adjust the rotation speed of the drum, or control the water inlet valve of the water dispenser to supply washing water to the tub.

[0061] 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 an algorithm for controlling the operation of components within the washing machine, at least one memory storing program-type data, and at least one processor performing the aforementioned operations using data stored in the at least one memory. The memory and the processor may each be implemented as separate chips. The processor may include one or more processor chips or one or more processing cores. The memory may include one or more memory chips or one or more memory blocks. Additionally, the memory and the processor may be implemented as a single chip.

[0062] Below, washing machines according to various embodiments are specifically described with reference to the attached drawings.

[0063] FIG. 1 illustrates an exterior view of a washing machine according to one embodiment, and FIG. 2 illustrates a side cross-section of the washing machine according to one embodiment.

[0064] Referring to FIGS. 1 and 2, the washing machine (100) may be a drum-type washing machine that washes laundry by rotating the drum (130) and repeatedly causing the laundry to rise and fall. The washing machine (100) may also be an electric washing machine that washes laundry by utilizing a water current generated by a pulsator when the drum (130) rotates.

[0065] That is, the control method of the washing machine (100) according to the present disclosure can be applied to both drum-type washing machines and electric washing machines. However, in the embodiment described below, for the purpose of explanation, a case in which the washing machine (100) according to one embodiment is a drum-type washing machine will be described as an example.

[0066] Referring to FIGS. 1 and 2, the washing machine (100) may include a cabinet (101). In addition, the washing machine (100) may further include a door (102), a user interface (110), a tub (120), a drum (130), a driving unit (140), a water supply unit (150), a drain unit (160), and a detergent supply unit (170) accommodated within the cabinet (101).

[0067] An inlet (101a) for loading or unloading laundry may be provided at the front center of the cabinet (101).

[0068] A door (102) may be provided in the inlet (101a). The door (102) may be rotatably mounted on the cabinet (101) by a hinge.

[0069] The door (102) can open and close the inlet (101a), and the closure of the inlet (101a) by the door (102) can be detected by the door switch (103). When the inlet (101a) is closed and the washing machine (100) is in operation, the door (102) can be locked by the door lock (104).

[0070] A user interface (110) including an input unit for obtaining user input from a user regarding the washing machine (100) and a display for displaying operation information of the washing machine (100) may be provided on the upper front side of the cabinet (101).

[0071] A tub (120) is provided inside the cabinet (101) and can accommodate water for washing and / or rinsing.

[0072] The tub (120) may include a tub front part (121) having an opening (121a) formed at the front and a tub rear part (122) having a cylindrical shape with a closed rear.

[0073] An opening (121a) may be provided on the front of the tub front part (121) for loading laundry into a drum (130) provided within the tub (120) or for taking laundry out of the drum (130). A bearing (122a) for rotatably fixing a motor (141) may be provided on the rear wall of the tub rear part (122).

[0074] The drum (130) is provided to be rotatable inside the tub (120), and is provided to be rotatable around a rotation axis (R) extending in the front-back direction, and can accommodate laundry.

[0075] The drum (130) may include a cylindrical drum body (131), a drum front part (132) provided at the front of the drum body (131), and a drum rear part (133) provided at the rear of the drum body (131).

[0076] The inner surface of the drum body (131) may be provided with a hole (131a) connecting the inside of the drum (130) and the inside of the tub (120) and a lifter (131b) for lifting laundry to the upper part of the drum (130) while the drum (130) rotates. The drum front part (132) may be provided with an opening (132a) for feeding laundry into the drum (130) or taking laundry out of the drum (130). The drum rear part (133) may be connected to a shaft (141a) of a motor (141) that rotates the drum (130).

[0077] The driving unit (140) may include a motor (141) that rotates the drum (130).

[0078] The motor (141) is provided on the outside of the tub rear part (122) of the tub (120) and can be connected to the drum rear part (133) of the drum (130) via a shaft (141a). The shaft (141a) passes through the tub rear part (122) and is rotatably supported by a bearing (122a) provided in the tub rear part (122).

[0079] The motor (141) may include a stator (142) fixed to the outside of the tub rear part (122) and a rotor (143) that is rotatably provided and connected to a shaft (141a). The rotor (143) may rotate through magnetic interaction with the stator (142), and the rotation of the rotor (143) may be transmitted to the drum (130) through the shaft (141a).

[0080] The motor (141) may include, for example, a brushless direct current motor (BLDC motor) or a permanent magnet synchronous motor (PMSM) whose rotation speed can be easily controlled.

[0081] The water supply unit (150) can supply water to the tub (120).

[0082] 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).

[0083] A water supply pipe (151) is provided on the upper side of the tub (120) and can extend from an external water source to the detergent tank (171). Water can be guided to the tub (120) through the detergent tank (171).

[0084] The water supply valve (152) can allow or block the supply of water from an external water source to the tub (120) in response to an electrical signal. The water supply valve (152) can include, for example, a solenoid valve that opens and closes in response to an electrical signal.

[0085] The drain (160) can discharge water contained in the tub (120) and / or drum (130) to the outside.

[0086] The drain (160) includes a drain pipe (161) provided on the lower side of the tub (120) and extending from the tub (120) to the outside of the cabinet (101), and a drain pump (162) provided on the drain pipe (161). The drain pump (162) can pump water in the drain pipe (161) to the outside of the cabinet (101).

[0087] The detergent supply (170) can supply detergent to the tub (120) and / or drum (130).

[0088] The detergent supply unit (170) may include a detergent container (171) provided on the upper side of the tub (120) to store detergent, and a mixing pipe (172) connecting the detergent container (171) to the tub (120).

[0089] The detergent container (171) is connected to the water supply pipe (151), and water supplied through the water supply pipe (151) can be mixed with detergent in the detergent container (171). The mixture of detergent and water can be supplied to the tub (120) through the mixing pipe (172).

[0090] Figure 3 illustrates a motor of a washing machine according to one embodiment.

[0091] Referring to FIG. 3, the motor (141) may include a stator (142) and a rotor (143). In one embodiment, the motor (141) may be a motor (141) having a rotor (143) radially outside one stator (142).

[0092] In one embodiment, the rotor (143) may be connected to the drum (130).

[0093] The rotor (143) shares the coil (142a) of the stator (142), and by supplying current (e.g., 3-phase current or 6-phase current) to the coil (142a), the motor (141) can drive the rotor (143) to rotate.

[0094] In one embodiment, the rotor (143) may be positioned outside the stator (142).

[0095] In various embodiments, the rotor (143) may be positioned inside the stator (142).

[0096] The rotor (143) is a cylindrical member with a flat bottom, and may include a rotor yoke (143a) installed on the main body of the lower part, and a plurality of magnets (143b) formed of permanent magnets in the shape of an arc.

[0097] According to various embodiments, 48 ​​magnets (143b) may be arranged in a circumferential direction with the N and S poles alternately arranged and fixed to the inner surface of the rotor yoke (143a).

[0098] The stator (142) may be formed as a member having an annular shape with an outer diameter smaller than the inner diameter of the rotor (143). The stator (142) may be provided with a plurality of teeth (142b) or coils (142a) embedded in resin. According to various embodiments, the stator (142) may be provided with 36 I-shaped teeth (142b) and coils (142a).

[0099] Teeth (142b) may be a thin plate-shaped iron member having an I-shaped cross-section, and may be arranged around the entire circumference of the stator (142) such that each is radially arranged at equal intervals. The inner and outer circumferential side ends of the teeth (142b) may protrude in a flange shape in the circumferential direction from both corners.

[0100] A coil (142a) can be formed for each tooth (142b) by sequentially winding a plurality of wires (e.g., six wires) covered with an insulating material through an insulating material in a predetermined order and configuration. A group of teeth (142b) on which a coil (142a) is formed can be embedded with a thermosetting resin by mold forming in a state where only the end faces of each diameter side are exposed, and can be fixed in a predetermined arrangement in an insulated state.

[0101] According to various embodiments, each coil (142a) may be formed by winding each of the six wires in a certain order around each of the 36 I-shaped teeth (142b).

[0102] The rotor (143) side end of the teeth (142b) is attached so that the stator (142) and the rotor (143) face each other with a small gap between them.

[0103] A motor (141) according to one embodiment can be designed so that the number of slots (S) of the stator (142) is 36 and the number of poles (P) of the rotor (143) is 48.

[0104] As previously described, the rotor (143) can be connected to the shaft (141a), and thus, can be connected to the drum (130).

[0105] A washing machine (100) according to one embodiment may include the mechanical configurations described with reference to FIGS. 1 and 2 as well as the electrical / electronic configurations described below.

[0106] Figure 4 illustrates a control block diagram of a washing machine according to one embodiment.

[0107] Referring to FIG. 4, the washing machine (100) may include a user interface (110), a driver (140), a water supply (150), a drain (160), sensors (180), and a control circuit (190).

[0108] The user interface (110) may include an input button for obtaining user input, and a display for displaying washing settings and / or washing operation information in response to the user input. The input button may include, for example, a power button, an operation button, a course selection dial, and a detailed setting button. The display may include a screen for displaying a washing course selected by rotation of the course selection dial and the operating time of the washing machine (100), and an indicator for displaying detailed settings selected by the setting button. The input button and the display may be provided separately, or may be implemented together as a touch screen.

[0109] Here, the washing cycle may include washing settings (e.g., washing temperature, number of rinse cycles, spin strength, etc.) preset by the designer of the washing machine (100) according to the type of laundry (e.g., blankets, underwear, etc.) and material (e.g., wool, etc.). For example, standard washing may include washing settings applicable to most laundry, and blanket washing may include washing settings optimized for washing blankets. Washing cycles may be categorized into, for example, standard washing, strong washing, wool washing, blanket washing, baby clothes washing, towel washing, small load washing, boiled washing, energy-saving washing, outdoor washing, rinse / spin, spin drying, etc.

[0110] The sensors (180) can detect data indicating the status of the washing machine (100). The data detected by the sensor unit (180) can be transmitted to the control circuit (190).

[0111] For example, the sensors (180) may include current sensors (181). The current sensors (181) can detect the current value supplied to the motor (141), and there is no limitation on the number of current sensors. In addition, the current sensors (181) may be installed without limitation at any location where they can detect the current supplied to the motor (141). For example, the current sensors (181) may be installed in all three-phase circuits to measure all three-phase currents, but may be installed in only two-phase circuits among the three-phase circuits depending on the embodiment. The motor current information detected by the current sensors (181) may be transmitted to the control circuit (190).

[0112] Additionally, the sensors (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 resolver. The rotor speed information detected by the speed sensor (182) may be transmitted to the control circuit (190).

[0113] The driver (140) can supply a driving current to the motor (141) in response to a control signal of the control circuit (190) to drive the motor (141).

[0114] The driver (140) can drive the motor (141) through the inverter circuit (144). The inverter circuit (144) can include an inverter including a plurality of pairs of switching elements. The inverter can convert direct current power into direct current or alternating current driving power and supply three-phase driving current to the motor (141). The inverter circuit (144) can include two switching elements (Q1 and Q2, Q3 and Q4, Q5 and Q6) in which the switching element pairs (Q1 and Q2, Q3 and Q4, Q5 and Q6) are each connected in series with each other. The switching elements (Q1, Q2, Q3, Q4, Q5, Q6) included in the inverter circuit (144) are turned on / off according to the control signal of the control circuit (190), and the three-phase driving current (I a , I b , I c ) can be supplied to the motor (141).

[0115] The driver (140) may include a rectifier circuit and a direct current link circuit in addition to the inverter circuit (144). The rectifier circuit may include a diode bridge composed of a plurality of diodes and may rectify AC power from an external power source. The direct current link circuit may include a direct current link capacitor that stores electrical energy and may remove ripples from the rectified power and output direct current power.

[0116] The control circuit (190) can be electrically connected to the user interface (110), the driver (140), the water supply (150), the drain (160), and the sensors (180).

[0117] 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 or memorizes a program and data for generating a control signal for controlling the operation of the washing machine (100).

[0118] The processor (191) and memory (192) may be implemented as separate semiconductor devices or as a single semiconductor device. In addition, the control circuit (190) may include a plurality of processors (191) or a plurality of memories (192).

[0119] The processor (191) can 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.

[0120] The processor (191) can receive user input from the user interface (110) and process the user input.

[0121] The processor (191) may output a control signal for controlling the motor (141), the water supply valve (152), the drain pump (162), and the door lock in response to a user input. 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 cycle, a rinsing cycle, and a dehydration cycle. In addition, the processor (191) may output a control signal for controlling the user interface (110) to display washing settings and washing operation information in response to the user input.

[0122] The processor (191) may include an arithmetic circuit, a memory circuit, and a control circuit. The processor (191) may include one chip or multiple chips. In addition, the processor (191) may include one core or multiple cores.

[0123] The memory (192) can store / remember data including a program for controlling washing operations according to a washing course and washing settings according to the washing course. In addition, the memory (192) can store / remember the currently selected washing course and washing settings based on user input.

[0124] The memory (192) may include volatile memory such as Static Random Access Memory (S-RAM), Dynamic Random Access Memory (D-RAM), and non-volatile memory such as Read Only Memory (ROM), Erasable Programmable Read Only Memory (EPROM). The memory (192) may include one memory or may include a plurality of memories.

[0125] The control circuit (190) can input a pulse width modulation controlled (PWM controlled) electric signal to the inverter circuit (144) using a predetermined command signal and a carrier wave composed of a triangle wave, and apply a direct current voltage to the motor (141). Each switching element (Q1, Q2, Q3, Q4, Q5, Q6) of the inverter circuit (144) can be turned on or off based on an electric signal (PWM control signal) output from the control circuit (190), and the power supplied to the motor (141) can be controlled by a combination of turning on and turning off.

[0126] The control circuit (190) can adjust an electric signal (PWM control signal) input to the inverter circuit (144) so ​​that the drum (130) rotates at the target speed based on the target speed of the drum (130) calculated from the motor current detected by the current sensor (181) or the rotor speed detected by the speed sensor (182).

[0127] FIG. 5 illustrates a control block diagram of a control circuit of a washing machine according to one embodiment.

[0128] Referring to FIG. 5, the control unit (190) and the motor (141) are connected through an inverter (144a) of an inverter circuit (144). The inverter (144a) can transmit a driving voltage to the motor (141) based on an electric signal output from the control unit (190). The operation of the rotor (143) of the motor (141) can be controlled based on the driving voltage transmitted from the inverter.

[0129] A current sensor (181) can be connected to the inverter (144a). The current sensor (181) can detect the current flowing in each phase of the inverter (144a). The current sensor (181) detects the three-phase current (phase a current, phase b current, phase c current) (I) output from the inverter (144a). abc ) can be detected. The current sensor (181) can transmit the detected three-phase current value to the control circuit (190). The current sensor (181) can detect the three-phase current (I abc ) can measure only two-phase current, and the control circuit (190) can estimate the other phase current from the two-phase current.

[0130] A speed sensor (182) that detects 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, etc. Instead of the speed sensor (182), a position sensor that detects the position (θ) of the rotor (143) may be used. At this time, 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.

[0131] 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).

[0132] The speed controller (200) compares the speed command (ω*) of the control circuit (190) with the speed value (ω) of the rotor (143), and based on the comparison result, sets the d-axis current command (I d *) and q-axis current command value (I q *) can be output. For example, the speed controller (200) uses proportional integral control (PI control) to control the speed error (ω), which is the difference between the speed command (ω*) of the rotor (143) and the speed value (ω) of the rotor (143). err = The d-axis current command (I) of the rotor (143) based on ω* - ω d *) and q-axis current command value (I q *) can be produced.

[0133] The current controller (210) outputs the d-axis current command (I) from the speed controller (200). d *) and q-axis current command value (I q *), the d-axis current value (I) output from the current converter (230) d ) and q-axis current value (I q ), the q-axis current command compensation value (I) output from the active feedforward controller (AFC) (250) qm *) and compare them, and based on the comparison results, the d-axis voltage command (V d *) and q-axis voltage reference (V q *) can be output. Specifically, the current controller (210) uses proportional integral control (PI control) to output the d-axis current command (I d *) and d-axis current value ((I d) based on the difference between the d-axis voltage command (V d *) and determine the q-axis current command (I q *), q-axis current value (I q ) and q-axis current command compensation value (I qm *) based on the difference between the q-axis voltage reference (V q *) can be judged.

[0134] The voltage converter (220) outputs the d-axis voltage command (V) from the current controller (210). d *) and q-axis voltage reference (V q *) 3-phase voltage reference (A-phase voltage reference, B-phase voltage reference, C-phase voltage reference) (V abc *) and can be output to the inverter (144a). At this time, the control circuit (190) uses a PWM generator to generate a three-phase voltage command (V abc *) can generate a PWM control signal and output it to the inverter (144a).

[0135] The current converter (230) converts the three-phase current value (I) detected by the current sensor (181) abc ) is the d-axis current value (I d ) and q-axis current value (I q ) and can be output to the current controller (210).

[0136] The position calculator (240) can convert the speed value (ω) detected by the speed sensor (182) into the position value (θ) of the rotor (143). For example, the position calculator (240) can be implemented as an integrator.

[0137] An active feedforward controller (AFC) (250) can be connected in parallel between the input node of the speed controller (200) and the input node of the current controller (210).

[0138] The active feedforward controller (AFC) (250) controls the speed error value (ω) of the rotor (143) err = ω* - ω) and the position value (θ) of the rotor (143) can be received.

[0139] The active feedforward controller (AFC) (250) controls the speed error value (ω) of the rotor (143) err = ω* - ω) and the position value (θ) of the rotor (143) based on the q-axis current command value (I q *) Q-axis current command compensation value (I qm *) can be printed.

[0140] The active feedforward controller (AFC) (250) controls the rotor speed error value (ω err ) to offset the m-th harmonic component filtered by the bandpass filter and the m-th harmonic component included in the q-axis current reference value (Iq*) based on the position value (θ) of the rotor. qm *) can be output. At this time, m can be a natural number. The active feedforward controller (AFC) (250) outputs the q-axis current command value (I q *) to compensate for the q-axis current command compensation value (I qm *) can be output to the input node of the current controller (210).

[0141] Figure 6 is a flowchart showing a control method of a washing machine according to one embodiment.

[0142] Referring to FIG. 6, the control circuit (190) can detect the speed of the motor (141) (300).

[0143] The control circuit (190) can detect the speed of the motor (141) through the speed sensor (182). Meanwhile, the control circuit (190) can detect the speed of the motor (141) through the current sensor (181) instead of the speed sensor (182). At this time, the control circuit (190) detects the three-phase current value (I) detected by the current sensor (181). abc ) is the d-axis current value (I d ) and q-axis current value (I q ) and convert it to the d-axis current value (I d ) and q-axis current value (I q) can be used to determine the speed of the motor (141). The control circuit (190) determines the d-axis current value (I) of the motor (141). d ) and q-axis current value (I q ) can be used to estimate the speed of the motor (141) from the motor modeling equation. For example, the position and speed of the motor (141) can be determined using sensorless vector control.

[0144] The control circuit (190) can determine the speed error value of the motor (141) based on the speed command of the motor (141) and the motor speed value detected by the speed sensor (182) (302).

[0145] The control circuit (190) calculates a speed error value (ω) from the speed command (ω*) of the rotor (143) and the speed value (ω) of the rotor (143). err = ω* - ω) can be determined.

[0146] The control circuit (190) can filter out the preset m-th harmonic component (m is a natural number) from the speed error value of the motor (141) through a bandpass filter (304).

[0147] The control circuit (190) can compensate for the q-axis current command value of the motor (141) based on the filtered m-th harmonic component and the position information (θ) of the rotor (141) (306).

[0148] The control circuit (190) can drive the motor (141) based on the compensated q-axis current command value (308).

[0149] According to the existing technology, cogging torque is generated due to the magnetic interaction between the stator (142) and the rotor (143) of the motor (141), and this cogging torque generates torque ripple in the form of a specific harmonic component, which causes torque fluctuations in the motor, thereby generating motor noise. Furthermore, this motor noise is greatly amplified when it meets the natural resonance frequency of the surrounding structure connected to the motor (141).

[0150] In one embodiment, the control circuit (190) filters out a harmonic component of a specific order from a speed error value of the rotor (143) through a bandpass filter, compensates for a q-axis current command value of the motor (141) based on the filtered harmonic component of a specific order and the position information (θ) of the rotor (143), and drives the motor based on the compensated q-axis current command value, thereby canceling out a harmonic component of a specific order generated by cogging torque of the motor (141) and included in the q-axis current command value of the motor, thereby reducing motor noise and reducing amplification of motor noise by meeting with a natural resonance frequency of a surrounding structure connected to the motor.

[0151] Figure 7 illustrates an example of an operating cycle of a washing machine according to one embodiment.

[0152] Referring to FIG. 7, the washing machine (100) can sequentially perform a washing cycle (400), a rinsing cycle (410), and a dehydration cycle (420) according to user input.

[0153] By the washing process (400), laundry can be washed. Specifically, foreign substances attached to the laundry can be separated by the chemical action of the detergent and / or mechanical action such as dropping.

[0154] The washing process (400) may include a laundry measurement (401) for measuring the amount of laundry, a water supply (402) for supplying water to the tub (120), a washing (403) for washing laundry by rotating the drum (130) at low speed, a drain (404) for discharging water contained in the tub (120), and an intermediate spin-drying (405) for separating water from the laundry by rotating the drum (130) at high speed.

[0155] For washing (403), the control circuit (190) can control the driver (140) to rotate the motor (141) in a forward direction (e.g., clockwise) or reverse direction (e.g., counterclockwise). By the rotation of the drum (130), laundry falls from the upper side to the lower side of the drum (130), and the laundry can be washed by the falling.

[0156] For intermediate dehydration (405), the control circuit (190) can control the driver (140) to rotate the motor (141) at high speed. By the high-speed rotation of the drum (130), water can be separated from the laundry contained in the drum (130) and discharged to the outside of the washing machine (100).

[0157] By the rinsing process (410), laundry can be rinsed. Specifically, detergent or foreign substances left on the laundry can be washed away by water.

[0158] The rinsing process (410) may include a water supply (411) that supplies water to the tub (120), a rinse (412) that drives the drum (130) to rinse laundry, a drain (413) that discharges water contained in the tub (120), and an intermediate spin-drying (414) that drives the drum (130) to separate water from laundry.

[0159] The water supply (411), drainage (413), and intermediate spin-drying (414) of the rinsing cycle (410) may be the same as the water supply (402), drainage (404), and intermediate spin-drying (405) of the washing cycle (400), respectively. During the rinsing cycle (410), the water supply (411), rinsing (412), drainage (413), and intermediate spin-drying (414) may be performed once or multiple times.

[0160] By the dehydration process (420), laundry can be dehydrated. Specifically, water is separated from the laundry by the high-speed rotation of the drum (130), and the separated water can be discharged to the outside of the washing machine (100).

[0161] The dehydration process (420) may include a final dehydration (421) that separates water from the laundry by rotating the drum (130) at high speed. Due to the final dehydration (421), the last intermediate dehydration (414) of the rinsing process (410) may be omitted.

[0162] For final dehydration (421), the control circuit (190) can control the driver (140) to rotate the motor (141) at high speed. By the high-speed rotation of the drum (130), water can 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) can be increased stepwise.

[0163] Since the operation of the washing machine (100) is terminated by the final dehydration (421), the execution time of the final dehydration (421) may be longer than the execution time of the intermediate dehydration (405, 414).

[0164] The washing machine (100) can perform a washing cycle (1010), a rinsing cycle (1020), and a spin-drying cycle (1030) to wash laundry. In particular, during the intermediate spin-drying (1015, 1024) and the final spin-drying (1031), the washing machine (100) can gradually increase the rotation speed of the motor (141) that rotates the drum (130).

[0165] The dehydration process described throughout the specification may mean all of the intermediate dehydration (405) performed in the washing process (400), the intermediate dehydration (414) performed in the rinsing process (410), and the final dehydration (421) performed in the dehydration process (420). However, for the convenience of explanation, the dehydration process is assumed to be the final dehydration (421) of the dehydration process (420) performed after the rinsing process (410).

[0166] According to one embodiment, the washing machine (100) may filter a preset m-th harmonic component (m is a natural number) from a speed error value of the rotor (143) through a bandpass filter during a spin-drying operation, compensate for a q-axis current command value of the motor (141) based on the filtered m-th harmonic component and position information (θ) of the rotor (143), and drive the motor based on the compensated q-axis current command value. At this time, the washing machine (100) may compensate for the q-axis current command value of the motor (141) in response to the speed of the rotor (143) being within a preset speed range during the spin-drying operation.

[0167] FIG. 8 illustrates an active feedforward controller (AFC) of a control circuit in a washing machine according to one embodiment.

[0168] Referring to FIG. 8, an active feedforward controller (AFC) (250) is connected in parallel between an input node (201) of a speed controller (200) and an input node (211) of a current controller (210), and can compensate for a q-axis current command value (Iq*) output from the speed controller (200) to the current controller (210).

[0169] The active feedforward controller (AFC) (250) controls the speed error value (ω) of the rotor (143) err ) to offset the m-th harmonic component filtered by the bandpass filter (221) and the m-th harmonic component included in the q-axis current command value (Iq*) based on the position value (θ) of the rotor (143). qm *) can be printed.

[0170] An active feedforward controller (AFC) (250) may include a bandpass filter (251), an AFC gain (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).

[0171] The bandpass filter (251) is used to calculate the speed error value (ω) of the rotor (143). err ) can filter out the preset m-th harmonic component. For example, the output of the bandpass filter (251) is BPF(ω err ) can be. Here, m can be a natural number. For example, m can be a multiple of 12.

[0172] The AFC gainer (252) can apply a preset gain value (-g) to the m-th harmonic component filtered by the bandpass filter (251) and output the applied value. At this time, 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 gainer (252) is ω errmth (ω errmth = BPF(ω err ) * (-g)) can be.

[0173] The first multiplier (253) can multiply the mth order cos(mθ) for the position (θ) of the rotor (143) by the output of the AFC gainer (252) and output the multiplied value. The output of the first multiplier (253) is BPF(ω err ) * (-g) * cos(mθ) can be.

[0174] The first integrator (254) can integrate the output of the first multiplier (253) and output the integrated value. The output of the first integrator (254) is β m (β m = ∫(ω errmth * cos(mθ)) can be β m may be an adaptation parameter of AFC.

[0175] The second multiplier (255) can multiply the output of the first integrator (255) by the mth order cos(mθ) and output the multiplied value. The output of the second multiplier (255) is I q β m (I q β m = β m* cos(mθ)) can be.

[0176] The third multiplier (256) can multiply the mth sin(mθ) for the position (θ) of the rotor (143) by the output of the AFC gainer (252) and output the multiplied value. The output of the third multiplier (256) is BPF(ω err ) * (-g) * sin(mθ) can be.

[0177] The second integrator (257) can integrate the output of the third multiplier (256) and output the integrated value. The output of the second integrator (257) is γ m (γ m = ∫(ω errmth * can be sin(mθ)) γ m may be an adaptation parameter of AFC.

[0178] The fourth multiplier (258) can multiply the mth order sin(mθ) by the output of the second integrator (257) and output the multiplied value. The output of the fourth multiplier (258) is I q γ m (I q γ m = γ m * can be sin(mθ)).

[0179] The adder (259) can add the outputs of the second multiplier (255) and the fourth multiplier (258) and output the added value. The output of the adder (259) is I qm *((I qm * = I q β m + I q γ m ) may be.

[0180] Adder (259) is I qm * can be output to the input node (211) of the current controller (210).

[0181] I output by the active feedforward controller (AFC) (250) qm* may be a q-axis current command compensation value to compensate for the q-axis current command value (Iq*). The q-axis current command compensation value (I qm *) can cancel out the m-th harmonic component included in the q-axis current reference value (Iq*).

[0182] Q-axis current command compensation value (I qm *) may be harmonic current values.

[0183] Q-axis current command compensation value (I qm *) may be a harmonic current value for generating a counter harmonic torque to the target harmonic torque. The q-axis current command compensation value (I qm *) may be a harmonic current value to generate a reaction harmonic torque that is equal to but opposite in direction to the target harmonic torque.

[0184] Q-axis current command compensation value (I qm *) may be a harmonic current value for offsetting the m-th harmonic torque of the motor (141).

[0185] Q-axis current command compensation value (I qm *) may be a harmonic current value to offset the harmonic torque of the cogging torque of the motor (141). The q-axis current command compensation value (I qm *) may be a harmonic current value for offsetting the m-th harmonic torque of the cogging torque of the motor (141).

[0186] The current controller (210) is an active feedforward controller (AFC) (250) that supplies a q-axis current command compensation value (I) to the input node (211) of the current controller (210). qm *) output from the speed controller (200) in response to outputting the q-axis current command (I q *), the q-axis current command compensation value (I qm *) and q-axis current value (I q ) subtracted q-axis current command (I q *) based on the q-axis voltage reference value (V q*) can be output. At this time, the control circuit (190) outputs a d-axis current command value (I) that does not contribute to the torque generation of the motor. d *) is fixed to 0 and the q-axis current command (I q *) can only be controlled. In this case, the current controller (210) controls the d-axis current value (I d ) based on the d-axis voltage reference value (V d *) can be printed.

[0187] The q-axis current command (I) output from the speed controller (200) to the current controller (210) q *) contains certain harmonic components due to cogging torque. Therefore, the q-axis current reference (I q *) may be a waveform shape that contains harmonic components rather than a sinusoidal waveform. In this way, the q-axis current command (I) of a waveform shape that contains harmonic components q *) may cause motor noise when driving the motor (141). However, in the present disclosure, the q-axis current command compensation value (I qm *) to obtain the q-axis current reference value (I q *) by compensating for the q-axis current reference value (I q *) can cancel out the harmonic components of a specific order included in the q-axis current command (I q *) can be maintained in a sinusoidal waveform, which can reduce motor noise.

[0188] The number of slots of the stator (142) of the motor (141) of the washing machine (100) is closely related to the harmonic components of the cogging torque generated in the motor (141). A change in the number of slots can affect the shape of the harmonic components of the cogging torque. For example, when the number of slots is 12, the 12th harmonic component among the harmonic components appears characteristically, when the number of slots is 24, the 24th harmonic component appears characteristically, when the number of slots is 36, the 36th harmonic component appears characteristically, and when the number of slots is 48, the 48th harmonic component may appear characteristically.

[0189] For example, in the case of the motor (141) illustrated in FIG. 3, since the number of slots of the stator (142) is 36, the 36th harmonic component is characteristically present among the harmonic components of the cogging torque, and this 36th harmonic component can have a major effect on motor noise.

[0190] FIG. 9 illustrates an example of an active feedforward controller of a control circuit in a washing machine according to one embodiment.

[0191] Referring to FIG. 9, the active feedforward controller (AFC) (250) provides a q-axis current command compensation value (I) to cancel out the 36th harmonic component. qm *) can be printed.

[0192] The first multiplier (253) outputs BPF(ω err ) * (-g) * cos(36θ) can be.

[0193] The output of the first integrator (254) is β 36th (β 36th = ∫(ω err36th * cos(36θ)) can be.

[0194] The output of the second multiplier (255) is I q β 36th (I q β 36th = β 36th * cos(36θ)) can be.

[0195] The output of the third multiplier (256) is BPF(ω err ) * (-g) * sin(36θ) can be.

[0196] The output of the second integrator (257) is γ 36th (γ 36th = ∫(ω err36th * can be sin(36θ)).

[0197] The output of the fourth multiplier (258) is I q γ 36th (I q γ 36th = γ 36th * can be sin(36θ)).

[0198] The output of the adder (259) is I qm *((I qm * = I q β 36th + I q γ 36th ) may be.

[0199] The q-axis current command compensation value (I) output by the active feedforward controller (AFC) (250) qm *) can cancel out the 36th harmonic component included in the q-axis current reference value (Iq*).

[0200] Fig. 10 is a flowchart showing a process of canceling out a 36th harmonic component included in a q-axis current command of a motor in a washing machine according to one embodiment.

[0201] Referring to FIG. 10, the control circuit (190) can initiate a dehydration process (500) based on a dehydration profile. To perform the dehydration process, the control circuit (190) can rotate the drum (130) based on the dehydration profile. The dehydration profile may be pre-stored, or may be modified based on factors such as the load of laundry.

[0202] The control circuit (190) can detect the speed of the motor (141) through the speed sensor (182) during the dehydration process (502).

[0203] The control circuit (190) can determine whether the motor speed is in the resonance band (504).

[0204] The resonance band may be the resonance band of the washing machine. The resonance band may be the resonance band of the motor or the resonance band of the surrounding structures (e.g., drum (130), tub (120), etc.) to which the motor (141) is connected. Since the motor (141) is mounted on the tub (120), if the natural frequency of the tub (120) and the rotation frequency of the motor (141) overlap, noise may increase significantly. Therefore, it is necessary to determine whether the motor speed is in the resonance band. The resonance band value may be a preset speed value or a preset speed range value. The resonance band value may be 500 rpm or a range value from 400 to 600 rpm. For example, when the number of motor slots is 36, motor noise due to the 36th harmonic component occurs during spin-drying, and the motor noise may be greatly amplified when it meets the resonance frequency of the tub (120) near 500 rpm.

[0205] If the motor speed is in the resonance band (example of 504), the control circuit (190) controls the speed error value (ω) of the motor (141). err ) can be determined (506).

[0206] The control circuit (190) calculates a speed error value (ω) from the speed command (ω*) of the rotor (143) of the motor (141) and the speed value (ω) of the rotor (143). err = ω* - ω) can be determined.

[0207] The control circuit (190) determines the speed error value (ω err ) filtered by a bandpass filter (251) that filters out the 36th harmonic component (ω) err36th ) can be determined (508).

[0208] The control circuit (190) passes the speed error value (ω) through the bandpass filter (251). err ) 36th harmonic component (BPF(ω) err)) The value to which the gain value (-g) of the AFC gainer (252) is applied ((BPF(ω) err ) * (-g)) is the 36th harmonic component (ω) filtered by the bandpass filter (251) err36th ) can be determined.

[0209] The control circuit (190) filters the 36th harmonic component (ω) filtered by the bandpass filter (251). err36th ) and the 36th adaptive parameters β of the active feedforward controller (AFC) (250) based on the position (θ) of the rotor (143). 36th and γ 36th can be determined (510).

[0210] The control circuit (190) is β 36th to ∫(ω err36th * can be determined by cos(36θ). The control circuit (190) is γ 36th to ∫(ω err36th * can be determined by sin(36θ).

[0211] The control circuit (190) is β 36th I, the current compensation value based on q β 36th and, γ 36th I, the current compensation value based on q γ 36th can be determined (512).

[0212] The control circuit (190) is I q β 36th to β 36th * can be determined by cos(36θ). The control unit (190) is I q γ 36th to γ 36th * can be determined by sin(36θ).

[0213] The control circuit (190) is I q β 36th and I q γ 36th Based on the q-axis current command compensation value (I qm *) can be determined (514).

[0214] The control circuit (190) is I q β 36th and I q γ 36th The q-axis current command compensation value (I) is calculated by adding qm *)(I qm * = I q β 36th + I q γ 36th ) can be determined.

[0215] The control unit (190) provides a q-axis current command compensation value (I qm *) can be generated to compensate for the q-axis current command value of the motor (141) (516).

[0216] The control circuit (190) can drive the motor (141) based on the compensated q-axis current command value (518).

[0217] If the motor speed is not in the resonance band (No of 504), the control circuit (190) sets the q-axis current command compensation value (I qm *) can be determined as 0 (520). Accordingly, the motor (141) can be driven based on the q-axis current command value that does not compensate for the motor (141).

[0218] In this way, the control circuit (190) provides a q-axis current command compensation value (I) in the resonance band. qm *) can be used to cancel out the 36th harmonic component included in the q-axis current reference value (Iq*), thereby reducing motor noise.

[0219] Fig. 11 shows the change in the 36th-order noise component when the active feedforward controller (AFC) is activated and deactivated in a washing machine according to one embodiment.

[0220] Figure 11 shows the results of an FFT (Fast Fourier Transform) analysis of motor noise measured at 500 rpm (36 motor slots, 60 Hz) with and without the AFC (250) in operation. This FFT analysis result shows the change in the 36th-order noise component between the activated and deactivated states of the AFC (250).

[0221] When AFC (250) was disabled (AFC off), the 36th noise component was 44.8 dBA at 300 Hz (500 rpm * 36 slots / 60 Hz). This represents the noise level when AFC (250) is not operating.

[0222] However, when AFC (250) was activated (AFC On), the 36th noise component was reduced to 30.0 dBA, which is lower than 44.8 dBA. This means that the 36th noise level was lower than before when AFC (250) was operating.

[0223] Therefore, the 36th-order noise component was reduced by 14.8 dBA depending on whether AFC (250) was activated or not. This indicates that the operation of AFC (250) is effective in reducing the 36th-order noise.

[0224] Fig. 12 illustrates a control block diagram of a control unit and a driving unit of a washing machine according to another embodiment.

[0225] Referring to FIG. 12, the AFC (250) may include a plurality of AFCs (250a to 250n).

[0226] When there are multiple m-th harmonic components to be offset, AFCs (250) can be connected in parallel as many times as the number of target order harmonic components.

[0227] The control circuit (190) can activate or deactivate all of the multiple AFCs (250a to 250n).

[0228] Unnecessarily activating too many AFCs (250) may degrade basic motor control stability. Therefore, the control circuit (190) may activate some of the multiple AFCs (250a to 250n) and deactivate the rest.

[0229] The control circuit (190) can activate only one of the multiple AFCs (250a to 250n) and deactivate all of the others. The corresponding AFC can be selected and activated depending on the m-th harmonic component to be offset.

[0230] In a washing machine (100) with 36 motor slots, the 36th harmonic component is of interest, so in order to cancel out only the 36th harmonic component, only the AFC corresponding to the 36th harmonic component among the multiple AFCs (205a to 250n) can be activated, and the remaining AFCs can be deactivated. The activated AFC extracts only the 36th harmonic component by applying a bandpass filter to the speed error value, thereby preventing deterioration of motor control stability while reducing motor noise.

[0231] The control circuit (190) can minimize the impact on motor control stability in other ranges by activating the AFC (250) only in the resonance band where the 36th noise occurs. For example, the AFC (250) can be activated only in the 400 to 600 rpm range, and deactivated in the remaining ranges.

[0232] FIG. 13 is a flowchart illustrating a process of selecting and activating one of a plurality of active feedforward controllers (AFCs) in a washing machine according to another embodiment.

[0233] Referring to FIG. 13, the control circuit (190) can initiate a dehydration process according to a dehydration profile (600). To perform the dehydration process, the control circuit (190) can rotate the drum (130) according to the dehydration profile.

[0234] The control circuit (190) can detect the speed of the motor (141) through the speed sensor (182) during the dehydration process (602).

[0235] The control circuit (190) can determine whether the motor speed is in the resonance band (604).

[0236] If the motor speed is in the resonance band (example of 604), the control circuit (190) can determine the target harmonic component of the order to be offset (606).

[0237] The control circuit (190) can determine the number of slots of the motor (141) based on information about the motor (141) mounted on the washing machine (100), and determine the target harmonic order component based on the number of motor slots. For example, if the number of motor slots is 36, the target harmonic order component can be determined as the 36th harmonic order component.

[0238] The control circuit (190) can select at least one AFC among a plurality of AFCs (250a to 250n) (608).

[0239] The control circuit (190) can select at least one AFC among a plurality of AFCs (250a to 250n) based on the target harmonic order component. For example, if the target harmonic order component is a 36th harmonic order component, an AFC designed to cancel out the 36th harmonic order component can be selected among the plurality of AFCs (250a to 250n).

[0240] The control circuit (190) can activate the selected AFC and deactivate the remaining AFCs (610).

[0241] If the motor speed is not in the resonance band (No of 604), the control circuit (190) can deactivate all of the multiple AFCs (250a to 250n) (612).

[0242] The control circuit (190) can minimize the impact on motor control stability in other ranges by activating the AFC (250) only in the resonance band where the 36th noise occurs. For example, the AFC (250) can be activated only in the 400 to 600 rpm range, and deactivated in the remaining ranges.

[0243] According to the present disclosure, harmonic components generated from a motor can be canceled out, thereby reducing motor noise.

[0244] According to the present disclosure, it is possible to reduce motor noise by canceling out specific harmonic components generated by cogging torque of the motor, and to reduce amplification of motor noise by meeting the natural resonance frequency of a surrounding structure connected to the motor.

[0245] According to one embodiment, a washing machine may include: a drum (130) rotatably provided inside a tub (120); a motor (141) including a stator (142) and a rotor (143) for rotating the drum (130); an inverter circuit (144) connected to the motor (141); and at least one processor (191) for controlling the inverter circuit (144) to compensate for a q-axis current command value of the motor (141) based on an m-th harmonic component (m is a natural number) filtered by a bandpass filter (251) from a speed error value of the rotor (143) and a position of the rotor (143), and to drive the motor (141) based on the compensated q-axis current command value.

[0246] The at least one processor can determine a q-axis current command compensation value for canceling out the m-th harmonic component included in the q-axis current command value of the motor, and compensate for the q-axis current command value of the motor based on the q-axis current command compensation value.

[0247] The at least one processor may compensate for a q-axis current command value of the motor in response to the speed of the rotor being within a preset speed range during the dehydration process.

[0248] The above m can be a multiple of 12.

[0249] The above m can be 36.

[0250] The at least one processor may include a speed controller (200) that outputs a q-axis current command value (Iq*) and a d-axis current command value (Id*) based on a speed error value of the rotor; a current controller (220) that outputs a d-axis voltage command value (Vq*) and a d-axis voltage command value (Vd*) based on the q-axis current command value (Iq*) and the d-axis current command value (Id*) output from the speed controller; and an active feedforward controller (AFC) (250) that outputs a q-axis current command compensation value for canceling an m-th harmonic component included in the q-axis current command value (Iq*) based on an m-th harmonic component filtered by the bandpass filter in the speed error value of the rotor and a position of the rotor.

[0251] The above AFC can be connected in parallel between the input node of the speed controller and the input node of the current controller.

[0252] The AFC includes a bandpass filter that filters a preset m-th harmonic component from the speed error value of the rotor, an AFC gainer (252) that applies a preset gain value to the m-th harmonic component filtered by the bandpass filter, a first multiplier (253) that multiplies the output of the AFC gainer by the m-th cos(mθ) for the position (θ) of the rotor, a first integrator (254) that integrates the output of the first multiplier, a second multiplier (255) that multiplies the output of the first integrator by the m-th cos(mθ), a third multiplier (256) that multiplies the output of the AFC gainer by the m-th sin(mθ) for the rotational position (θ) of the rotor, a second integrator (257) that integrates the output of the third multiplier, and a fourth multiplier that multiplies the output of the second integrator by the m-th sin(mθ). It may include a multiplier (258) and an adder (259) that adds the outputs of the second multiplier and the fourth multiplier.

[0253] The at least one processor may activate the AFC in response to the speed of the rotor being within a preset speed range during the dehydration process.

[0254] The above preset speed range may include the resonance band of the washing machine.

[0255] The at least one processor includes a speed controller for outputting a q-axis current command value (Iq*) and a d-axis current command value (Id*) based on a speed error value of the rotor; a current controller for outputting a q-axis voltage command value (Vq*) and a d-axis voltage command value (Vd*) based on the q-axis current command value (Iq*) and the d-axis current command value (Id*) output from the speed controller; and a plurality of active feedforward controllers (AFCs) for outputting a q-axis current command compensation value for canceling an m-th harmonic component included in the q-axis current command value (Iq*) based on an m-th harmonic component filtered by the bandpass filter in the speed error value of the rotor and a position of the rotor; wherein the plurality of AFCs may be connected in parallel between an input node of the speed controller and an input node of the current controller, respectively.

[0256] The at least one processor can determine a harmonic component of a target order based on the number of slots of the rotor, select at least one of the plurality of AFCs based on the harmonic component of the target order, activate the selected at least one AFC, and deactivate the remaining AFCs.

[0257] The at least one processor may activate the selected AFC in response to the speed of the rotor being within a resonant band of the washing machine or the speed of the rotor being within a preset speed range during a spin cycle.

[0258] A control method of a washing machine according to one embodiment may include a control method of a washing machine including a drum rotatably provided inside a tub, and a motor including a stator and a rotor for rotating the drum, the method including: filtering a preset m-th harmonic component (m is a natural number) from a speed error value of the rotor through a bandpass filter; compensating a q-axis current command value of the motor based on the filtered m-th harmonic component and the position of the rotor; and driving the motor based on the compensated q-axis current command value.

[0259] Compensating for the q-axis current command value of the motor may include determining a q-axis current command compensation value for offsetting the m-th harmonic component included in the q-axis current command value of the motor, and compensating for the q-axis current command value of the motor based on the q-axis current command compensation value.

[0260] 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 the speed of the rotor being within a preset speed range during the dehydration process.

[0261] In filtering the preset m-th harmonic component, m may be a multiple of 12.

[0262] The washing machine includes an active feedforward controller (AFC) that outputs a q-axis current command compensation value for canceling out the m-th harmonic component based on the filtered m-th harmonic component and the position of the rotor, and compensating for the q-axis current command value of the motor may include activating the AFC in response to the speed of the rotor being within a preset speed range during a spin-drying cycle.

[0263] Compensating the q-axis current command value of the motor may include activating the AFC in response to the speed of the rotor being in the resonance band of the washing machine during the spin-drying cycle.

[0264] The washing machine includes a plurality of active feedforward controllers (AFCs) that output a q-axis current command compensation value for canceling out an m-th harmonic component filtered by the bandpass filter from a speed error value of the rotor and an m-th harmonic component based on a position of the rotor; and compensating for the q-axis current command value of the motor may include determining a target-order harmonic component based on the number of slots of the rotor, selecting at least one of the plurality of AFCs based on the target-order harmonic component, activating the selected at least one AFC, and deactivating the remaining AFCs.

[0265] Meanwhile, the disclosed embodiments may be implemented in the form of a storage medium storing computer-executable instructions. The instructions may be stored in the form of program code, and when executed by a processor, may generate program modules to perform the operations of the disclosed embodiments.

[0266] A device-readable storage medium may be provided in the form of a non-transitory storage medium. Here, the term "non-transitory storage medium" simply means a tangible device that does not contain signals (e.g., electromagnetic waves). This term does not distinguish between cases where data is permanently stored in the storage medium and cases where data is temporarily stored. For example, a "non-transitory storage medium" may include a buffer in which data is temporarily stored.

[0267] According to one embodiment, the method according to various embodiments disclosed in the present document may be provided as included in a computer program product. The computer program product may be traded as a product between a seller and a buyer. The computer program product may be distributed in the form of a machine-readable storage medium (e.g., compact disc read only memory (CD-ROM)), or may be distributed online (e.g., downloaded or uploaded) via an application store (e.g., Play Store™) or directly between two user devices (e.g., smartphones). In the case of online distribution, at least a portion of the computer program product (e.g., a downloadable app) may be temporarily stored or temporarily generated in a machine-readable storage medium, such as the memory of a manufacturer's server, an application store's server, or an intermediary server.

[0268] The disclosed embodiments have been described with reference to the attached drawings as described above. Those skilled in the art will understand that the present invention can be implemented in forms other than the disclosed embodiments without altering the technical spirit or essential features of the present invention. The disclosed embodiments are illustrative and should not be construed as limiting.

Claims

1. A drum that is rotatable and provided inside the tub; A motor comprising a stator and a rotor and rotating the drum; an inverter circuit connected to the above motor; and A washing machine comprising at least one processor for controlling the inverter circuit to compensate for a q-axis current command value of the motor based on an m-th harmonic component (m is a natural number) filtered by a bandpass filter from a speed error value of the rotor and the position of the rotor, and to drive the motor based on the compensated q-axis current command value.

2. In paragraph 1, At least one processor of the above, A washing machine which determines a q-axis current command compensation value for canceling out the m-th harmonic component included in the q-axis current command value of the motor, and compensates for the q-axis current command value of the motor based on the q-axis current command compensation value.

3. In paragraph 2, At least one processor of the above, A washing machine that compensates for the q-axis current command value of the motor in response to the speed of the rotor being within a preset speed range during a dehydration process.

4. In paragraph 1, The above m is a washing machine that is a multiple of 12.

5. In paragraph 4, The above m is a 36-inch washing machine.

6. In paragraph 1, At least one processor of the above, A speed controller that outputs a q-axis current command value (Iq*) and a d-axis current command value (Id*) based on the speed error value of the rotor; A current controller that outputs a d-axis voltage command value (Vq*) and a d-axis voltage command value (Vd*) based on the q-axis current command value (Iq*) and the d-axis current command value (Id*) output from the speed controller; and A washing machine including an active feedforward controller (AFC) that outputs a q-axis current command compensation value for canceling out the m-th harmonic component filtered by the bandpass filter from the speed error value of the rotor and the m-th harmonic component included in the q-axis current command value (Iq*) based on the position of the rotor.

7. In paragraph 6, The above AFC is a washing machine connected in parallel between the input node of the speed controller and the input node of the current controller.

8. In paragraph 6, The AFC is a washing machine including a bandpass filter that filters a preset m-th harmonic component from a speed error value of the rotor, an AFC gainer that applies a preset gain value to the m-th harmonic component filtered by the bandpass filter, a first multiplier that multiplies an output of the AFC gainer by an m-th cos(mθ) with respect to the position (θ) of the rotor, a first integrator that integrates the output of the first multiplier, a second multiplier that multiplies the output of the first integrator by the m-th cos(mθ), a third multiplier that multiplies the output of the AFC gainer by an m-th sin(mθ) with respect to the rotational position (θ) of the rotor, a second integrator that integrates the output of the third multiplier, a fourth multiplier that multiplies the output of the second integrator by the m-th sin(mθ), and an adder that adds the outputs of the second multiplier and the fourth multiplier.

9. In paragraph 6, A washing machine wherein said at least one processor activates said AFC in response to the speed of said rotor being within a preset speed range during a spin-drying operation.

10. In paragraph 9, The above preset speed range is a washing machine that includes the resonance band of the washing machine.

11. In paragraph 1, At least one processor of the above, A speed controller that outputs a q-axis current command value (Iq*) and a d-axis current command value (Id*) based on the speed error value of the rotor; A current controller that outputs a q-axis voltage command value (Vq*) and a d-axis voltage command value (Vd*) based on the q-axis current command value (Iq*) and the d-axis current command value (Id*) output from the speed controller; and It includes a plurality of active feedforward controllers (AFCs) that output a q-axis current command compensation value for canceling the m-th harmonic component filtered by the bandpass filter from the speed error value of the rotor and the m-th harmonic component included in the q-axis current command value (Iq*) based on the position of the rotor; A washing machine in which the above plurality of AFCs are each connected in parallel between the input node of the speed controller and the input node of the current controller.

12. In paragraph 11, At least one processor of the above, Based on the number of slots of the above rotor, the harmonic components of the target order are determined, Selecting at least one of the plurality of AFCs based on the harmonic components of the target order, A washing machine that activates at least one AFC selected above and deactivates the remaining AFCs.

13. In paragraph 12, At least one processor of the above, A washing machine that activates the selected AFC in response to the speed of the rotor being within the resonance band of the washing machine or the speed of the rotor being within a preset speed range during a spin-drying cycle.

14. A method for controlling a washing machine including a drum rotatably provided inside a tub and a motor including a stator and a rotor and rotating the drum, Filtering out the preset m-th harmonic component (m is a natural number) from the speed error value of the rotor through a bandpass filter; Compensating the q-axis current command value of the motor based on the filtered m-th harmonic component and the position of the rotor; A control method for a washing machine, comprising: driving the motor based on the compensated q-axis current command value.

15. In paragraph 14, Compensating the q-axis current command value of the above motor is: A control method for a washing machine, comprising: determining a q-axis current command compensation value for offsetting the m-th 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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