Dryer and method for controlling same

Abstract

The disclosed dryer comprises: a drum that accommodates an object to be dried; a multi-phase circuit including a plurality of electrodes spaced apart from each other on the outside of the drum and a power supply unit for applying voltage to the plurality of electrodes; and a control unit that controls the power supply unit such that a voltage of one phase among multi-phase voltages is applied to each of the plurality of electrodes and voltages of different phases are applied between two adjacent electrodes, wherein the control unit may adjust the phase of the voltage applied to at least one of the plurality of electrodes on the basis of a voltage for determining an impedance balance of the multi-phase circuit exceeding a reference voltage or a reverse flow of power from the plurality of electrodes to the power supply unit.

Description

Dryer and method of controlling the same

[0001] The disclosed invention relates to a dryer capable of drying a drying object through genetic heating and a method for controlling the same.

[0002] A dryer is a device that dries an object by removing moisture from the object. Various types of dryers exist. For example, there are dryers that supply hot air into a drum containing the object to be dried. When supplying hot air into the drum, heat is transferred from air, which has a low specific heat, to water, which has a high specific heat. This results in low heat transfer efficiency and, consequently, low drying efficiency. Furthermore, the high-temperature air supplied into the drum can damage the object.

[0003] The present disclosure can provide a dryer and a control method of the dryer that can improve the uniformity of drying of a drying object by controlling the phase of voltage applied to a plurality of electrodes.

[0004] A dryer according to the invention comprises: a drum for accommodating a material to be dried; a multi-phase circuit including a plurality of electrodes spaced apart from each other on the outside of the drum and a power supply unit for applying voltage to the plurality of electrodes; and a control unit for controlling the power supply unit so that a voltage of one phase among multi-phase voltages is applied to each of the plurality of electrodes and voltages of different phases are applied between two adjacent electrodes; wherein the control unit can adjust the phase of the voltage applied to at least one electrode among the plurality of electrodes based on whether a voltage for determining impedance balance of the multi-phase circuit exceeds a reference voltage or whether power flows back from the plurality of electrodes to the power supply unit.

[0005] A control method of a dryer according to the idea of ​​the present disclosure may include a control method of a dryer including a multi-phase circuit including a drum for accommodating a material to be dried, a plurality of electrodes spaced apart from each other and a power supply unit for applying voltage to the plurality of electrodes, wherein the control method may include controlling the power supply unit so that a voltage of one phase among multi-phase voltages is applied to each of the plurality of electrodes and voltages of different phases are applied between two adjacent electrodes, and adjusting the phase of the voltage applied to at least one electrode among the plurality of electrodes based on whether a voltage for determining impedance balance of the multi-phase circuit exceeds a reference voltage or whether power flows back from the plurality of electrodes to the power supply unit.

[0006] According to one aspect of the disclosed invention, the uniformity of drying of a drying object can be improved by controlling the phase of voltage applied to a plurality of electrodes.

[0007] According to one aspect of the disclosed invention, when a phenomenon occurs in which power flows back from a plurality of electrodes to a power supply unit, the phase of the voltage applied to the plurality of electrodes can be adjusted to prevent damage to various components for drying.

[0008] The effects that can be obtained from the present disclosure are not limited to the effects mentioned above, and other effects that are not mentioned can be clearly understood by a person having ordinary skill in the art to which the present disclosure belongs from the description below.

[0009] Figure 1 illustrates a dryer according to one embodiment.

[0010] Figure 2 is a cross-sectional view of a dryer according to one embodiment.

[0011] Figure 3 illustrates the arrangement structure of electrodes according to one embodiment.

[0012] Figure 4 is a control block diagram of a dryer according to one embodiment.

[0013] FIG. 5 illustrates a graph of voltages applied to multiple electrodes of a dryer according to one embodiment.

[0014] FIG. 6 illustrates an example of controlling the phase and / or magnitude of voltage applied to multiple electrodes according to one embodiment.

[0015] Figure 7 illustrates an equivalent circuit diagram of a multi-phase circuit according to one embodiment.

[0016] FIG. 8 illustrates the impedance of a plurality of electrodes generated according to the rotation of the drum according to one embodiment.

[0017] Figure 9 shows a graph of the impedance of each phase of the multi-phase circuit of the dryer.

[0018] FIG. 10 is a flowchart illustrating a method for adjusting the phase of a voltage based on a voltage for determining impedance balance of a multi-phase circuit according to one embodiment.

[0019] FIG. 11 is a flowchart illustrating a method for controlling the phase of a voltage based on the reverse flow of power from a plurality of electrodes to a power supply according to one embodiment.

[0020] FIG. 12 is a flowchart illustrating a method for adjusting the phase of a voltage applied to a plurality of electrodes based on a voltage for determining impedance balance of a multi-phase circuit when power flows back from a plurality of electrodes to a power supply according to one embodiment.

[0021] The embodiments described in this specification and the configurations illustrated in the drawings are merely preferred examples of the disclosed invention, and there may be various modified examples that can replace the embodiments and drawings of this specification at the time of filing of this application.

[0022] The terminology used herein is for the purpose of describing embodiments only and is not intended to limit and / or restrict the disclosed invention.

[0023] For example, in this specification, a singular expression may include a plural expression unless the context clearly indicates otherwise.

[0024] 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.

[0025] The term "and / or" includes any combination of a plurality of related described elements or any one of a plurality of related described elements.

[0026] 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).

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] Additionally, terms such as "~part", "~device", "~block", "~absence", and "~module" may refer to a unit that processes at least one function or operation. For example, the terms may refer to at least one hardware such as an FPGA (field-programmable gate array) / ASIC (application specific integrated circuit), at least one software stored in a memory, or at least one process processed by a processor.

[0032] Hereinafter, a dryer according to various embodiments will be specifically described with reference to the attached drawings.

[0033] Figure 1 illustrates a dryer according to one embodiment.

[0034] A dryer (1) may include a cabinet (1a) forming an exterior and a drum (20) rotatably installed within the cabinet (1a). The cabinet (1a) may be provided in an approximately hexahedral shape. The cabinet (1a) may include an upper cover (1b) forming an upper surface, a front cover (1c) forming a front surface, and a base forming a bottom surface.

[0035] For example, the front cover (1c), the top cover (1b), and the base forming the cabinet (1a) may be separately prepared and assembled. As another example, some components forming the cabinet (1a) (e.g., the front cover, the top cover, and the base) may be formed integrally.

[0036] An inlet (31) is provided on the front of the cabinet (1a) for loading or unloading the material to be dried into the drum (20). The dryer (1) may include a door (50) provided to open and close the inlet (31) formed on the front cover (1c). After opening the door (50), a user can load or unload the material to be dried into the drum (20) through the inlet (31). When the inlet (31) is closed and the dryer (1) begins to operate, a door lock may lock the door (50).

[0037] A user interface (200) for interaction between a user and the dryer (1) may be provided on the upper front side of the cabinet (1a). The user interface (200) may obtain user input and display various information regarding the dryer (1). The location of the user interface (200) is not limited to the front. The user interface (200) may be provided at various locations on the dryer (1).

[0038] The user interface (200) may include a display. Furthermore, the user interface (200) may include an input unit for obtaining user input regarding the operation of the dryer (1). The input unit may include a rotatable dial and various buttons. Additionally, the user interface (200) may include various types of input units and displays.

[0039] The display may be provided in the form of various display panels. For example, the display may include a liquid crystal display panel (LCD panel), a light emitting diode panel (LED panel), an organic light emitting diode panel (OLED panel), or a micro LED panel. The display may also be used as an input device, including a touch screen.

[0040] The display can display user-entered information or information provided to the user on various screens. The display can display information related to the operation of the dryer (1) in the form of at least an image or text. In addition, the display can display a graphical user interface (GUI) that enables control of the dryer (1). That is, the display can display UI elements (User Interface Elements), such as icons.

[0041] The input unit can transmit an electrical signal (voltage or current) corresponding to a user input to the control unit (300). The input unit can include various buttons and / or dials. For example, the input unit can include at least one of a power button for turning the dryer (1) on or off, a start / stop button for starting or stopping the drying operation, a drying course button for selecting a drying course, a temperature button for setting the drying temperature, and a time button for setting the drying time. The various buttons can be provided as physical buttons or touch buttons.

[0042] The dial included in the input unit may be configured to be rotatable. UI elements displayed on the display may move sequentially as the dial rotates. The dryer (1) may perform drying according to a selected drying course. The drying course may include drying parameters such as drying temperature and drying time. Different drying courses may be selected depending on the location of the object to be dried within the drum (20), the type of the object to be dried, and / or the amount of the object to be dried.

[0043] The dryer (1) may include a filter (40) detachably mounted on the front cover (1c). The filter (40) may filter out foreign substances such as lint that flow together with the air circulating inside the drum (20).

[0044] Figure 2 is a cross-sectional view of a dryer according to one embodiment.

[0045] A cylindrical drum (20) may be provided inside the cabinet (1a). The drum (20) is provided to accommodate a drying material therein so that drying can be performed. The drum (20) may be provided to be rotatable by receiving power from a motor (72). The drum (20) may be provided inside the cabinet (1a) so as to be rotatable around a rotating axis that is provided approximately horizontally with respect to the ground.

[0046] A lifter (21) may be provided on the inner surface of the drum (20) to lift the object to be dried when the drum (20) rotates. Depending on the rotation speed of the drum (20), the object to be dried may be repeatedly raised and lowered by the lifter (21). A roller (22) may be provided on the outer surface of the drum to support the drum (20) so that it rotates smoothly.

[0047] The driving device may be placed on the inner lower part of the cabinet (1a). The driving device may be mounted on the base. The driving device may include a motor (72), a pulley (74) and a belt (75) for transmitting the power of the motor (72) to the drum (20).

[0048] A pulley (74) can be connected to a rotary shaft (73) connected to a motor (72). When the rotary shaft (73) is rotated by the motor (72), the pulley (74) can rotate together with the rotary shaft (73). A belt (75) can be installed so as to be wound around the outer surface of the pulley (74) and the outer surface of the drum (20). When the belt (75) is rotated by the driving force of the motor (72), the drum (20) can rotate together with the belt (75). The drum (20) can rotate clockwise or counterclockwise.

[0049] A passage (80) for circulating air may be formed inside the cabinet (1a) and inside the drum (20). The passage (80) may include an air exhaust passage (81) for discharging air from inside the drum (20) to outside the drum (20), and an air supply passage (82) for supplying air to inside the drum (20).

[0050] The dryer (1) may include an exhaust duct (60) forming an air exhaust path (81). A filter (40) may be arranged at an inlet (61) of the exhaust duct (60). The exhaust duct (60) may pass through the cabinet (1a), and an outlet (63) of the exhaust duct (60) may be exposed to the outside of the cabinet (1a). Air flowing into the inlet (61) of the exhaust duct (60) may be filtered while passing through the filter (40). The filter (40) may filter out foreign substances such as lint contained in the air.

[0051] A fan (71) for circulating air may be provided inside the cabinet (1a). By the rotation of the fan (71), air inside the drum (20) may be introduced into the exhaust duct (60). In addition, by the rotation of the fan (71), air may be supplied into the drum (20) through the air supply path (83) and the air inlet (20b) of the drum (20). The air supplied into the drum (20) may be used for drying the object to be dried.

[0052] The motor (72) can rotate not only the drum (20) but also the fan (71). Although the drum (20) and the fan (71) are exemplified as being driven by a single motor (72), this is not limited thereto. A separate fan motor may be provided to drive the fan (71). In addition, the motor (72) may be directly connected to the drum (20) to rotate the drum (20). If the motor (72) is directly connected to the drum (20), the pulley (74) and the belt (75) may be omitted.

[0053] A plurality of electrodes may be provided between the cabinet (1a) and the drum (20). In Fig. 3, two electrodes (90a, 90b) are illustrated. The electrodes (90a, 90b) may be spaced apart from each other on the outside of the drum (20). For example, the electrodes (90a, 90b) may be spaced apart from each other along the periphery of the drum (20). The electrodes (90a, 90b) may also be spaced apart from the cabinet (1a) and the drum (20). When voltage is applied to the electrodes (90a, 90b), an electric field may be generated inside the drum (20). The electric field generated inside the drum (20) may vibrate a dielectric (e.g., water molecules) included in the object to be dried. When the dielectric (e.g., water molecules) vibrates, dipole frictional heat may be generated, which may heat the dielectric. The object to be dried may be dried by evaporating the heated dielectric. The evaporated dielectric can be discharged outside the drum (20) together with the air supplied into the drum (20). The electrodes are described in more detail in FIG. 3 below.

[0054] Figure 3 illustrates the arrangement structure of electrodes according to one embodiment.

[0055] A plurality of electrodes (90) may be spaced apart from each other and arranged on the outside of the drum (20). For example, a plurality of electrodes (90) may be spaced apart from each other along the outer periphery of the drum (20). The plurality of electrodes (90) may each be provided in a plate shape having a curvature. The plurality of electrodes (90) may be provided in various numbers. For example, three electrodes (90a, 90b, 90c) may be spaced apart from each other and arranged adjacent to each other along the outer periphery of the drum (20). The first electrode (90a) may be arranged on the upper right side of the drum (20), the second electrode (90b) may be arranged below the drum (20) adjacent to the first electrode (90a), and the third electrode (90c) may be arranged on the upper left side of the drum (20) adjacent to the first electrode (90a). However, the arrangement of the electrodes according to the present disclosure is not limited thereto, and the electrodes may be arranged according to various embodiments. For example, the first electrode (90a) may be arranged on top of the drum (20), the second electrode (90b) may be arranged on the lower right side of the drum (20) adjacent to the first electrode (90a), and the third electrode (90c) may be arranged on the lower left side of the drum (20) adjacent to the first electrode (90a).

[0056] The number of electrodes according to the present disclosure is not limited to those illustrated in the drawings. For example, the number of electrodes may be two, or four or more.

[0057] A plurality of electrodes (90) can be fixed between the cabinet (1a) and the drum (20). Since the drum (20) is not connected to the plurality of electrodes (90), the plurality of electrodes (90) do not restrict the rotation of the drum (20). In addition, since the plurality of electrodes (90) are arranged along the circumference of the drum (20), an electric field can be generated in various areas within the drum (20). Therefore, the disclosed dryer (1) can generate an electric field within the drum (20) through the plurality of electrodes (90) even while the drum (20) rotates, and can perform drying of the object to be dried.

[0058] Fig. 4 is a control block diagram of a dryer according to one embodiment. Fig. 5 illustrates a graph of voltages applied to multiple electrodes of a dryer according to one embodiment. Fig. 6 illustrates an example of adjusting the phase and / or magnitude of voltages applied to multiple electrodes of a dryer according to one embodiment.

[0059] The dryer (1) may include a user interface (200), a communication interface (250), a multi-phase circuit (100), a power sensor (150), and a control unit (300).

[0060] The user interface (200) can acquire user input and display various information regarding the operation of the dryer (1). The user interface (200) may include an input unit for acquiring user input and a display for displaying information. In addition, the user interface (200) may also include a speaker for outputting sound.

[0061] The user interface (200) may display operation information of the dryer (1). For example, the user interface (200) may display a drying course, a drying temperature, an estimated drying time, and / or a remaining time until the end of drying. The drying course may include predetermined drying settings (e.g., a drying degree, an additional time to prevent wrinkles, a drying time) depending on the type of the object to be dried (e.g., a shirt, a comforter, an undergarment) and the material (e.g., cotton, wool). For example, the standard drying may include drying settings applicable to most objects to be dried, and the comforter drying may include drying settings optimized for drying comforters.

[0062] The communication interface (250) can connect to an external device (e.g., a user device, a server) via a network. The control unit (300) can obtain various information, signals, and / or data from the external device via the communication interface (250). For example, the communication interface (250) can receive a remote control signal from the user device. The control unit (300) can obtain firmware and / or software for the operation of the dryer (1) from the server via the communication interface (250).

[0063] The communication interface (250) may include various communication circuits. The communication interface (250) may include wireless communication circuits and / or wired communication circuits. For example, a communication circuit supporting wireless communication methods such as wireless local area network (WLAN), home radio frequency (RF), infrared communication, ultra-wide band (UWB) communication, Wi-Fi, Bluetooth, and Zigbee may be provided.

[0064] A multi-phase circuit (100) may include a plurality of electrodes (90), a power supply (110), a phase shifter (120), a coupler (130), and / or a matching circuit (140).

[0065] The power supply unit (110) may include a DC power supply unit (111) and / or an RF power supply unit (112).

[0066] The DC power supply unit (111) can convert AC power supplied from a commercial power source (S) into DC power and transmit it to the RF power supply unit (112). The control unit (300) can control the DC power supply unit (111) to adjust the magnitude of the voltage applied to the plurality of electrodes (90). When the DC power transmitted by the DC power supply unit (111) to the RF power supply unit (112) increases, the amplitude of the high-frequency signal generated by the RF power supply unit (112) increases, and the magnitude of the voltage applied to the plurality of electrodes (90) can increase. The magnitude of the voltage can be expressed as an effective value.

[0067] The RF power supply unit (112) can generate a high-frequency signal using DC power received from the DC power supply unit (111). The high-frequency signal can include an RF (Radio Frequency) signal. The RF power supply unit (112) can apply the generated high-frequency signal to a plurality of electrodes (90). A sinusoidal voltage can be applied to the plurality of electrodes (90) by the high-frequency signal.

[0068] The matching circuit (140) is composed of the impedance of the power supply unit (110) and the impedance (Z) of each of the plurality of electrodes (90). a , Z b , Z c , see Fig. 7) can be matched. The matching circuit (140) may include a variable inductor and a variable capacitor.

[0069] The impedance of the power supply unit (110) and the impedance (Z) of each of the plurality of electrodes (90) a , Z b , Z c ) if there is a difference between the impedance of the power supply unit (110) and the impedance of each of the plurality of electrodes (90), a reflected power is generated from the plurality of electrodes (90), and the power transmission efficiency is reduced. In order to minimize the reflected power, the impedance of the power supply unit (110) and the impedance (Z) of each of the plurality of electrodes (90) are a , Z b , Z c) needs to be performed. The control unit (300) can perform impedance matching by controlling the matching circuit (140).

[0070] The coupler (130) can detect a high-frequency signal generated by the power supply unit (110) to apply voltage to a plurality of electrodes (90). For example, the coupler (130) can detect a high-frequency signal generated by the RF power supply unit (112) and transmit the detected high-frequency signal to the control unit (300).

[0071] The phase shifter (120) can change the phase of the voltage applied to the plurality of electrodes (90). For example, the phase shifter (120) can change the phase of the voltage applied to the plurality of electrodes (90) by controlling the high-frequency signal generated by the power supply unit (110). The phase shifter (120) can include a PLL (Phase Locked Loop) circuit for changing the phase of the voltage applied to the plurality of electrodes (90). The PLL circuit is configured as a closed loop and can perform a function of changing the phase or frequency of the high-frequency signal.

[0072] Although the phase converter (120) according to the present disclosure is described as a separate configuration from the control unit (300), the phase converter (120) may be provided as a component of the control unit (300).

[0073] The power sensor (150) can measure the current and / or voltage output from each component of the multi-phase circuit (100) or applied to each component.

[0074] For example, the power sensor (150) can measure current and / or voltage applied to multiple electrodes (90).

[0075] For another example, if the multi-phase circuit (100) includes a matching circuit (140), the power sensor (150) can measure the current and / or voltage applied to the matching circuit (140).

[0076] As another example, the power sensor (150) can measure the current and / or voltage output from the DC power supply (111).

[0077] The power sensor (150) can transmit information about the measured current and / or voltage to the control unit (300). The control unit (300) can determine the power output from each component of the multi-phase circuit (100) and the power supplied to each component based on the information about the current and / or voltage transmitted from the power sensor (150). For example, the control unit (300) can determine the power supplied to the plurality of electrodes (90) based on the current and voltage applied to the plurality of electrodes (90). For another example, the control unit (300) can determine the power supplied to the matching circuit (140) based on the current and voltage applied to the matching circuit (140). For another example, the control unit (300) can determine the power output by the DC power supply unit (111) based on the current and voltage output by the DC power supply unit (111).

[0078] The control unit (300) may include a processor (310) and a memory (320).

[0079] The memory (320) may include volatile memory (e.g., S-RAM, D-RAM) and non-volatile memory (e.g., ROM, EPROM). The processor (310) and the memory (320) may be implemented as separate chips or as a single chip. In addition, a plurality of processors and a plurality of memories may be provided. The processor (310) may process various data and various signals using instructions, data, programs, and / or software stored in the memory (320). The processor (310) may generate control signals for controlling components of the dryer (1). The processor (310) may include one core or a plurality of cores.

[0080] In one embodiment, the control unit (300) can control the power supply unit (110) so that a voltage of one phase among the multi-phase voltages is applied to each of the plurality of electrodes (90), and voltages of different phases are applied between two adjacent electrodes.

[0081] For example, referring to FIG. 5, the multi-phase voltage may include a first voltage (V1), a second voltage (V2), and a third voltage (V3), which are voltages of different phases. The phase difference of the first voltage (V1), the second voltage (V2), and the third voltage ( p) may be 120 degrees. The control unit (300) may control the power supply unit (110) so that a first voltage (V1) is applied to the first electrode (90a). The control unit (300) may control the power supply unit (110) so that a second voltage (V2) is applied to the second electrode (90b). The control unit (300) may control the power supply unit (110) so that a third voltage (V3) is applied to the third electrode (90c). That is, voltages of different phases may be applied to the first electrode (90a), the second electrode (90b), and the third electrode (90c).

[0082] However, the phase of the voltage applied to the electrodes according to this example is not limited to this. For example, voltages of the same phase may be applied to non-adjacent electrodes among a plurality of electrodes. In another example, the phase difference of the voltage applied to adjacent electrodes may be determined depending on the number of electrodes.

[0083] Referring to FIG. 6, in one embodiment, the control unit (300) can adjust the phase of the voltage applied to at least one of the plurality of electrodes (90).

[0084] For example, the control unit (300) can adjust the phase of the first voltage (V1) applied to the first electrode (90a) (AP1). The control unit (300) can adjust the phase of the second voltage (V2) applied to the second electrode (90b) (AP2). The control unit (300) can adjust the phase of the third voltage (V3) applied to the third electrode (90c) (AP3).

[0085] When adjusting the phase of at least one electrode among the plurality of electrodes (90a), the phase difference between the voltages applied to the plurality of electrodes (90a) p) can be changed. For example, if the phase of the first voltage (V1) is adjusted (AP1), the phase difference between the first voltage (V1) and the second voltage (V2) ( p1) and the phase difference between the first voltage (V1) and the third voltage (V3) ( p3) can change.

[0086] In one embodiment, the control unit (300) can adjust the magnitude of the voltage applied to at least one of the plurality of electrodes (90).

[0087] For example, the control unit (300) can adjust the magnitude of the first voltage (V1) (AM1). The control unit (300) can adjust the magnitude of the second voltage (V2) (AM2). The control unit (300) can adjust the magnitude of the third voltage (V3) (AM3).

[0088] Fig. 7 illustrates an equivalent circuit diagram of a multi-phase circuit according to one embodiment. Fig. 8 illustrates the impedance of a plurality of electrodes generated according to the rotation of a drum according to one embodiment. Fig. 9 illustrates a graph of the impedance of each phase of a multi-phase circuit of a dryer.

[0089] The multi-phase circuit (100) may be a three-phase (R-phase, T-phase, S-phase) circuit in which a power supply unit (110) and a plurality of electrodes (90) are each connected. However, the multi-phase circuit (100) according to the present disclosure is not limited thereto, and the multi-phase circuit (100) may be a two-phase circuit or a circuit having four or more phases.

[0090] For convenience, the multi-phase circuit (100) is described below as a three-phase circuit.

[0091] A multi-phase circuit (100) may include a neutral point (N) connecting each phase of the multi-phase circuit (100). For example, if the multi-phase circuit (100) is a three-phase circuit, it may include a neutral point (N) to which all three phases (R phase, T phase, S phase) are connected.

[0092] The power supply unit (110) can perform the function of a three-phase AC power source (T-phase power source, R-phase power source, S-phase power source), and each of the plurality of electrodes (90) can be connected to each phase of the power supply unit (110). The control unit (300) can control the power supply unit (110) so that voltages (V1, V2, V3) are applied to each of the plurality of electrodes (90), and accordingly, power can be supplied to each of the plurality of electrodes (90). For example, the first power (P) is applied to the first electrode (90a). T ) can be supplied, and the second electrode (90b) is supplied with a second power (P R ) can be supplied, and the third electrode (90c) is supplied with a third power (P S ) can be supplied. When the multi-phase circuit (100) includes a matching circuit (140), the first power (P T ) may be the power supplied to the first electrode (90a) through the matching circuit (140), and the second power (P R ) may be the power supplied to the second electrode (90b) through the matching circuit (140), and the third power (P S ) may be power supplied to the third electrode (90c) through the matching circuit (140).

[0093] The coupler (130) is connected between the power supply unit (110) and the matching circuit (140) and can detect a high-frequency signal generated by the power supply unit (110). For example, the coupler (130) is connected to the power supply unit (110) and can detect a high-frequency signal transmitted from the power supply unit (110) to a plurality of electrodes (90) through the matching circuit (140).

[0094] The coupler (130) may include an isolated port through which a high-frequency signal generated by the power supply unit (110) is detected. The coupler (130) may detect the high-frequency signal detected at the isolated port and transmit the detected high-frequency signal to the control unit (300). The coupler (130) may include a high-impedance element. This may minimize electrical signal loss at the input and output terminals of the coupler (130).

[0095] In one embodiment, the control unit (300) can determine the impedance of each phase of the multi-phase circuit (100) based on the high-frequency signal detected by the coupler (130). For example, the control unit (300) receives the high-frequency signal detected by the coupler (130), processes the received high-frequency signal, and determines the voltage (V) of each phase of the multi-phase circuit (100). T , V R , V S ) and the current (I) of each phase of the multi-phase circuit (100) T , I R , I S ) and determine the voltage (V) of each phase of the multi-phase circuit (100) T , V R , V S ) and / or the current (I) of each phase of the multi-phase circuit (100) T , I R , I S ), the impedance (Z) of each phase of the multi-phase circuit (100) T , Z R , Z S ) can be judged.

[0096] The matching circuit (140) is connected between the coupler (130) and the plurality of electrodes (90), and can transmit a high-frequency signal generated by the power supply unit (110) to the plurality of electrodes (90). As described above, a sinusoidal voltage can be applied to the electrodes (90) by the high-frequency signal.

[0097] The phase converter (120) can convert the phase of the voltage applied to the plurality of electrodes (90) based on the control signal received from the control unit (300). For example, the phase converter (120) can convert the phase of the voltage applied to each of the plurality of electrodes (90) by adjusting the high-frequency signal generated by the power supply unit (110) based on the control signal received from the control unit (300).

[0098] Referring to Fig. 8, the impedance (Z) of each of the plurality of electrodes (90) a , Z b , Z c ) is a capacitor (C) formed by a plurality of electrodes (90) and a drying material (D). a ,C b, C c ) may be included. For example, the plurality of electrodes (90) function as positive and / or negative electrodes of the capacitor, and moisture contained in the drying material (D) may function as a dielectric of the capacitor formed by the plurality of electrodes (90). Therefore, when an electric field is formed inside the drum (20), polar molecules such as water molecules inside the drying material (D) exposed to the electric field vibrate, and heat is generated due to the vibration of the polar molecules. Since moisture generally has a high permittivity, moisture contained in the drying material (D) exposed to the electric field is relatively quickly heated and evaporated. Therefore, moisture in the drying material (D) can be removed.

[0099] The impedance (Z) of each of the plurality of electrodes (90) a , Z b , Z c ) is a resistance (R) formed by a plurality of electrodes (90) and a drying material (D).a , R b , R c ) may be included. For example, resistance may be formed due to the internal resistance of the plurality of electrodes (90) and / or the disturbance of electrical flow caused by the object (D).

[0100] The impedance (Z) of each of the plurality of electrodes (90) a , Z b , Z c ) may have different values ​​depending on the state of the drying material (D) (e.g., moisture content of the drying material), distribution of the drying material (D) within the drum (20), rotation speed of the drum (20), etc.

[0101] For example, if the multi-phase circuit (100) is a three-phase circuit, the impedance (Z) of each of the plurality of electrodes (90) a , Z b , Z c ) is the first electrode impedance (Z a ), second electrode impedance (Z b ) and third electrode impedance (Z c ) may be included, and when the drum (20) rotates at a predetermined speed and the state of the drying material (D) (e.g., moisture content of the drying material), distribution of the drying material (D) within the drum (20), etc. change over time, the first electrode impedance (Z a ), second electrode impedance (Z b ) and / or third electrode impedance (Z c ) can change.

[0102] Referring to Figure 9, the impedance (Z) of each of the plurality of electrodes (90) a , Z b , Z c ) is changed, the impedance (Z) of each phase of the multi-phase circuit (100) T , Z R , Z S ) can be changed. For example, as the drum (20) rotates, the first electrode impedance (Z a ), second electrode impedance (Z b ) and third electrode impedance (Zc ) is changed, the impedance (Z) of each phase of the multi-phase circuit (100) T , Z R , Z S ) at least one impedance can be changed.

[0103] Multiphase circuit (100) Impedance of each phase (Z T , Z R , Z S ) The equilibrium condition is the impedance (Z) of each phase of the multiphase circuit (100) T , Z R , Z S ) may contain all of the same values ​​(Z T = Z R = Z S ) Multi-phase circuit (100) Impedance of each phase (Z T , Z R , Z S ) When the equilibrium condition is satisfied, a uniform power can be supplied to each of the plurality of electrodes (90) from the power supply unit (110). However, as the drum (20) rotates, the impedance (Z) of each phase of the multi-phase circuit (100) T , Z R , Z S ) is changed, the impedance (Z) of each phase of the multi-phase circuit (100) T , Z R , Z S ) may have different values, which may cause power to flow back from the plurality of electrodes (90) to the power supply (110). The backflow of power may include power not being supplied from the power supply (110) to the plurality of electrodes (90) but being supplied to the power supply (110).

[0104] For example, at the first time point (t1), the first power (P T ), second power (P R ) and the third power (P S) can be supplied to each of the plurality of electrodes (90) from the power supply unit (110). At the second time point (t2), the second power (P R ) is supplied to the second electrode (90b), and the third power (P S ) is supplied to the third electrode (90c), but the first power (P T ) can be supplied to the power supply unit (110). At the third time point (t3), the third power (P S ) is supplied to the third electrode (90c), but the first power (P T ) and the second power (P R ) can be supplied to the power supply unit (110).

[0105] FIG. 10 is a flowchart illustrating a method for adjusting the phase of a voltage based on a voltage for determining impedance balance of a multi-phase circuit according to one embodiment.

[0106] The control unit (300) can control the power supply unit (110) so that voltage is applied to a plurality of electrodes (90) (1000). The control unit (300) can control the power supply unit (110) so that voltage of one phase among multi-phase voltages is applied to each of the plurality of electrodes (90), and voltages of different phases are applied between two adjacent electrodes.

[0107] The control unit (300) can obtain a voltage for determining the impedance balance of the multiphase circuit (100). For example, the voltage for determining the impedance balance of the multiphase circuit (100) may include the neutral point voltage (Vn) of the multiphase circuit (100). However, the voltage for determining the impedance balance of the multiphase circuit according to the present disclosure is not limited thereto, and may be included therein if it is a voltage capable of determining the impedance balance of the multiphase circuit.

[0108] In one embodiment, the control unit (300) controls the impedance (Z) of each phase of the multi-phase circuit (100). T , Z R , Z S) can be used to obtain a voltage for determining the impedance balance of a multi-phase circuit (100). For example, if the voltage for determining the impedance balance of a multi-phase circuit (100) is a neutral point voltage (Vn), the neutral point voltage (Vn) can be obtained by the following [Mathematical Formula 1].

[0109] [Mathematical Formula 1]

[0110]

[0111] For example, the control unit (300) uses the high-frequency signal detected by the coupler (130) to determine the impedance (Z) of each phase of the multi-phase circuit (100). T , Z R , Z S ) is obtained, and the impedance (Z) of each phase of the multi-phase circuit (100) T , Z R , Z S ) can be used to obtain a voltage for determining the impedance balance of a multi-phase circuit (100).

[0112] In one embodiment, the control unit (300) may adjust the phase of the voltage applied to at least one of the plurality of electrodes (90) based on the fact that the voltage for determining the impedance balance of the multi-phase circuit (100) exceeds the reference voltage (example of 1100) (1200). The fact that the voltage for determining the impedance balance of the multi-phase circuit (100) exceeds the reference voltage may mean that the magnitude of the voltage for determining the impedance balance of the multi-phase circuit (100) exceeds the magnitude of the reference voltage. Here, when the voltage for determining the impedance balance of the multi-phase circuit (100) is the neutral point voltage (Vn), the magnitude of the voltage for determining the impedance balance of the multi-phase circuit (100) may be expressed as the root mean square (RMS) value of the neutral point voltage (Vn). The magnitude of the reference voltage may be expressed as the root mean square (RMS) value of the reference voltage.

[0113] For example, referring to FIG. 6, the control unit (300) can adjust the phase of at least one of the first voltage (V1), the second voltage (V2), and the third voltage (V3) based on whether the voltage for determining the impedance balance of the multi-phase circuit (100) exceeds the reference voltage (AP1, AP2, AP3).

[0114] In one embodiment, the control unit (300) can control the phase shifter (120) to shift the phase of the voltage applied to the plurality of electrodes (90) based on whether the voltage for determining the impedance balance of the multi-phase circuit (100) exceeds the reference voltage.

[0115] For example, the control unit (300) can control the phase shifter (120) to change the phase of the voltage applied to the plurality of electrodes (90) by adjusting the high-frequency signal generated by the power supply unit (110) based on the voltage for determining the impedance balance of the multi-phase circuit (100) exceeding the reference voltage.

[0116] In one embodiment, the control unit (300) can adjust the magnitude of the voltage applied to the plurality of electrodes (90) based on whether the voltage for determining the impedance balance of the multi-phase circuit (100) exceeds the reference voltage.

[0117] For example, referring to FIG. 6, the control unit (300) can adjust the magnitude of at least one of the first voltage (V1), the second voltage (V2), and the third voltage (V3) based on whether the voltage for determining the impedance balance of the multi-phase circuit (100) exceeds the reference voltage (AM1, AM2, AM3).

[0118] As another example, the control unit (300) can adjust the phase and magnitude of at least one of the first voltage (V1), the second voltage (V2), and the third voltage (V3) based on whether the voltage for determining the impedance balance of the multi-phase circuit (100) exceeds the reference voltage (AP1, AP2, AP3, AM1, AM2, AM3).

[0119] In one embodiment, the control unit (300) determines the impedance balance of the multi-phase circuit (100) based on whether the voltage exceeds the reference voltage and the impedance of the power supply unit (110) and the impedance of each of the plurality of electrodes (Z a , Z b , Z c , the matching circuit (140) can be controlled so that the matching circuit (see Fig. 7) is matched.

[0120] For example, the control unit (300) adjusts the phase of the voltage applied to at least one of the plurality of electrodes (90) based on whether the voltage for determining the impedance balance of the multi-phase circuit (100) exceeds the reference voltage, and adjusts the impedance of the power supply unit (110) and the impedance of each of the plurality of electrodes (Z a , Z b , Z c ) can be controlled to match the matching circuit (140).

[0121] In one embodiment, the control unit (300) may adjust the phase of the voltage applied to at least one of the plurality of electrodes (90) so that the voltage for determining the impedance balance of the multi-phase circuit (100) becomes lower than the reference voltage based on the voltage for determining the impedance balance of the multi-phase circuit (100) exceeding the reference voltage.

[0122] In one embodiment, the control unit (300) may adjust the phase of the voltage applied to at least one of the plurality of electrodes (90) so that the voltage for determining the impedance balance of the multi-phase circuit (100) becomes lower than or equal to a reference voltage, and then adjust the phase of the voltage applied to at least one of the plurality of electrodes (90) based on the voltage for determining the impedance balance of the multi-phase circuit (100) exceeding the reference voltage. For example, after adjusting the phase of the voltage applied to at least one of the plurality of electrodes (90) so that the voltage for judging the impedance balance of the multi-phase circuit (100) becomes lower than the reference voltage, if drying is not completed (NO of 1300), the voltage for judging the impedance balance of the multi-phase circuit (100) is obtained again, and based on the fact that the obtained voltage for judging the impedance balance of the multi-phase circuit (100) exceeds the reference voltage, the phase of the voltage applied to at least one of the plurality of electrodes (90) can be adjusted again.

[0123] FIG. 11 is a flowchart illustrating a method for controlling the phase of a voltage based on the reverse flow of power from a plurality of electrodes to a power supply according to one embodiment.

[0124] As described above, the control unit (300) can control the power supply unit (110) so that voltage is applied to the plurality of electrodes (90) (2000 and 1000 of FIG. 10).

[0125] In one embodiment, the control unit (300) can adjust the phase of the voltage applied to at least one of the plurality of electrodes (90) based on the reverse flow of power from the plurality of electrodes (90) to the power supply unit (110) (example of 2100) (2200).

[0126] For example, referring to FIG. 6, the control unit (300) supplies the first power (P T ), second power (P R ) and the third power (P S) based on at least one power supplied to the power supply unit (110), the phase of at least one of the first voltage (V1), the second voltage (V2) and the third voltage (V3) can be adjusted (AP1, AP2, AP3).

[0127] In one embodiment, the control unit (300) can control the phase shifter (120) to shift the phase of the voltage applied to the plurality of electrodes (90) based on the reverse flow of power from the plurality of electrodes (90) to the power supply unit (110).

[0128] For example, the control unit (300) may supply the first power (P T ), second power (P R ) and the third power (P S ) based on at least one power supplied to the power supply unit (110), the phase shifter (120) can be controlled to change the phase of the voltage applied to the plurality of electrodes (90) by adjusting the high-frequency signal generated by the power supply unit (110).

[0129] In one embodiment, the control unit (300) can adjust the magnitude of the voltage applied to the plurality of electrodes (90) based on the reverse flow of power from the plurality of electrodes (90).

[0130] For example, referring to FIG. 6, the control unit (300) supplies the first power (P T ), second power (P R ) and the third power (P S ) can control the magnitude of at least one of the first voltage (V1), the second voltage (V2) and the third voltage (V3) based on the power supplied to the power supply unit (110) (AM1, AM2, AM3).

[0131] For another example, the control unit (300) may supply a first power (P T ), second power (P R ) and the third power (P S) based on the power supplied to the power supply unit (110), the phase and magnitude of at least one of the first voltage (V1), the second voltage (V2) and the third voltage (V3) can be adjusted (AP1, AP2, AP3, AM1, AM2, AM3).

[0132] Referring to FIGS. 10 and 11, in one embodiment, the control unit (300) may adjust the phase of the voltage applied to at least one of the plurality of electrodes (90) based on whether the voltage for determining the impedance balance of the multi-phase circuit (100) exceeds a reference voltage (example 1100 of FIG. 10) or whether power has flowed backward from the plurality of electrodes (90) to the power supply unit (110) (example 2100 of FIG. 11). For example, before detecting whether power has flowed backward from the plurality of electrodes (90) to the power supply unit (110), the control unit (300) may obtain the voltage for determining the impedance balance of the multi-phase circuit (100) and adjust the phase of the voltage applied to at least one of the plurality of electrodes (90) based on whether the obtained voltage for determining the impedance balance of the multi-phase circuit (100) exceeds the reference voltage.

[0133] According to the present disclosure, the phenomenon of power backflow in which power is supplied from a plurality of electrodes (90) to a power supply unit (110) can be prevented, thereby preventing damage to each component of a multi-phase circuit (100).

[0134] According to the present disclosure, power can be efficiently supplied to the plurality of electrodes (90) by preventing a power backflow phenomenon in which power is supplied from the plurality of electrodes (90) to the power supply unit (110).

[0135] In one embodiment, the control unit (300) determines the impedance of the power supply unit (110) and the impedance (Z) of each of the plurality of electrodes based on the reverse flow of power from the plurality of electrodes (90) to the power supply unit (110). a , Z b , Z c, the matching circuit (140) can be controlled so that the matching circuit (see Fig. 7) is matched.

[0136] For example, the control unit (300) adjusts the phase of the voltage applied to at least one of the plurality of electrodes (90) based on the reverse flow of power from the plurality of electrodes (90) to the power supply unit (1110), and adjusts the impedance of the power supply unit (110) and the impedance (Z) of each of the plurality of electrodes. a , Z b , Z c ) can be controlled to match the matching circuit (140).

[0137] According to the present disclosure, the phase of the voltage applied to the plurality of electrodes (90) is controlled while the impedance (Z) of each of the plurality of electrodes is controlled. a , Z b , Z c ) by matching the plurality of electrodes (90), power can be efficiently supplied to the plurality of electrodes (90).

[0138] FIG. 12 is a flowchart illustrating a method for adjusting the phase of a voltage applied to a plurality of electrodes based on a voltage for determining impedance balance of a multi-phase circuit when power flows back from a plurality of electrodes to a power supply according to one embodiment.

[0139] The control unit (300) can control the power supply unit (110) so that voltage is applied to the plurality of electrodes (90) (3000, 1000 of FIG. 10 and 2000 of FIG. 11). The control unit (300) can adjust the phase of the voltage applied to at least one of the plurality of electrodes (90) based on the reverse flow of power from the plurality of electrodes (90) to the power supply unit (110) (3100, example of 2100 of FIG. 11) (3200, 2200 of FIG. 11).

[0140] The control unit (300) can obtain a voltage for determining the impedance balance of the multi-phase circuit (100) (3300). For example, the control unit (300) can obtain the neutral point voltage (Vn) of the multi-phase circuit (100).

[0141] In one embodiment, the control unit (300) can adjust the phase of the voltage applied to at least one of the plurality of electrodes (90) so that the voltage for determining the impedance balance of the multi-phase circuit (100) becomes lower than the reference voltage based on the reverse flow of power from the plurality of electrodes (90) to the power supply unit (110).

[0142] For example, the control unit (300) may adjust the phase of the voltage applied to at least one of the plurality of electrodes (90) based on the reverse flow of power from the plurality of electrodes (90) to the power supply unit (110) (Example of 3100), and then obtain a voltage for determining the impedance balance of the multi-phase circuit (100) (3300), and if the obtained voltage for determining the impedance balance of the multi-phase circuit (100) is greater than the reference voltage (No of 3400), the control unit (300) may adjust the phase of the voltage applied to at least one of the plurality of electrodes (90) again.

[0143] In one embodiment, the control unit (300) may adjust the phase of the voltage applied to at least one of the plurality of electrodes (90) so that the voltage for determining the impedance balance of the multi-phase circuit (100) becomes lower than or equal to the reference voltage (example of 3400), and then adjust the phase of the voltage applied to at least one of the plurality of electrodes (90) based on the reverse flow of power from the plurality of electrodes (90) to the power supply unit (110) (example of 3100).

[0144] According to one embodiment of the present disclosure, a dryer comprises: a drum for accommodating a drying material; a multi-phase circuit including a plurality of electrodes spaced apart from each other on the outside of the drum and a power supply unit for applying voltage to the plurality of electrodes; and a control unit for controlling the power supply unit so that a voltage of one phase among multi-phase voltages is applied to each of the plurality of electrodes and voltages of different phases are applied between two adjacent electrodes; wherein the control unit can adjust the phase of the voltage applied to at least one electrode among the plurality of electrodes based on whether a voltage for determining impedance balance of the multi-phase circuit exceeds a reference voltage or whether power flows back from the plurality of electrodes to the power supply unit.

[0145] The control unit can adjust the phase of the voltage applied to at least one of the plurality of electrodes so that the voltage for determining the impedance balance of the multi-phase circuit exceeds a reference voltage or the voltage for determining the impedance balance of the multi-phase circuit becomes lower than the reference voltage based on the reverse flow of power from the plurality of electrodes to the power supply unit.

[0146] The control unit may adjust the phase of the voltage applied to at least one of the plurality of electrodes so that the voltage for determining the impedance balance of the multi-phase circuit is lower than or equal to a reference voltage, and then adjust the phase of the voltage applied to at least one of the plurality of electrodes based on whether the voltage for determining the impedance balance of the multi-phase circuit exceeds the reference voltage or whether power is reversely flowed from the plurality of electrodes to the power supply unit.

[0147] The above control unit can obtain a voltage for determining the impedance balance of the multi-phase circuit by using the impedance of each phase of the multi-phase circuit.

[0148] The above multi-phase circuit further includes a coupler that detects a high-frequency signal generated by the power supply unit to apply voltage to the plurality of electrodes; and the control unit can obtain the impedance of each phase of the multi-phase circuit using the high-frequency signal detected by the coupler.

[0149] The above multi-phase circuit may further include a phase converter that converts the phase of the voltage applied to the plurality of electrodes.

[0150] The control unit can control the phase shifter so that the phase of the voltage applied to the plurality of electrodes is shifted based on whether the voltage for determining the impedance balance of the multi-phase circuit exceeds a reference voltage or whether power flows back from the plurality of electrodes to the power supply unit.

[0151] The control unit can adjust the magnitude and phase of the voltage applied to at least one of the plurality of electrodes based on whether the voltage for determining the impedance balance of the multi-phase circuit exceeds a reference voltage or whether power flows back from the plurality of electrodes to the power supply unit.

[0152] The above multi-phase circuit may further include a matching circuit that matches the impedance of the power supply unit and the impedance of each of the plurality of electrodes.

[0153] The control unit can control the matching circuit so that the impedance of the power supply unit and the impedance of each of the plurality of electrodes are matched based on whether the voltage for determining the impedance balance of the multi-phase circuit exceeds a reference voltage or whether power flows back from the plurality of electrodes to the power supply unit.

[0154] A control method of a dryer according to one embodiment of the present disclosure may include a control method of a dryer including a multi-phase circuit including a drum for accommodating a material to be dried, a plurality of electrodes spaced apart from each other on the outside of the drum, and a power supply unit for applying voltage to the plurality of electrodes, wherein the control method may include controlling the power supply unit so that a voltage of one phase among multi-phase voltages is applied to each of the plurality of electrodes, and voltages of different phases are applied between two adjacent electrodes, and adjusting the phase of the voltage applied to at least one electrode among the plurality of electrodes based on whether a voltage for determining impedance balance of the multi-phase circuit exceeds a reference voltage or whether power flows back from the plurality of electrodes to the power supply unit.

[0155] Adjusting the phase of the voltage applied to at least one of the plurality of electrodes based on whether the voltage for determining the impedance balance of the multi-phase circuit exceeds a reference voltage or whether power flows back from the plurality of electrodes to the power supply unit; may include adjusting the phase of the voltage applied to at least one of the plurality of electrodes so that the voltage for determining the impedance balance of the multi-phase circuit exceeds a reference voltage or whether power flows back from the plurality of electrodes to the power supply unit becomes less than or equal to the reference voltage.

[0156] Adjusting the phase of the voltage applied to at least one of the plurality of electrodes based on whether the voltage for determining the impedance balance of the multi-phase circuit exceeds a reference voltage or whether power flows back from the plurality of electrodes to the power supply unit; may include adjusting the phase of the voltage applied to at least one of the plurality of electrodes so that the voltage for determining the impedance balance of the multi-phase circuit becomes lower than or equal to the reference voltage, and then adjusting the phase of the voltage applied to at least one of the plurality of electrodes based on whether the voltage for determining the impedance balance of the multi-phase circuit exceeds the reference voltage or whether power flows back from the plurality of electrodes to the power supply unit.

[0157] A method for controlling a dryer according to one embodiment of the present disclosure may further include obtaining a voltage for determining impedance balance of the multi-phase circuit by using the impedance of each phase of the multi-phase circuit.

[0158] A control method of a dryer according to one embodiment of the present disclosure may further include obtaining an impedance of each phase of the multi-phase circuit by using the high-frequency signal detected by the coupler, in a control method of a dryer, wherein the multi-phase circuit further includes a coupler that detects a high-frequency signal generated by the power supply unit to apply voltage to the plurality of electrodes.

[0159] In the method for controlling a dryer, wherein the multi-phase circuit further includes a phase shifter for shifting the phase of voltage applied to the plurality of electrodes, the method may include: controlling the phase shifter so that the phase of voltage applied to at least one of the plurality of electrodes is shifted based on whether the voltage for determining the impedance balance of the multi-phase circuit exceeds a reference voltage or whether power has flowed back from the plurality of electrodes to the power supply unit.

[0160] A method for controlling a dryer according to one embodiment of the present disclosure may further include adjusting the magnitude of a voltage applied to at least one of the plurality of electrodes based on whether a voltage for determining impedance balance of the multi-phase circuit exceeds a reference voltage or whether power flows back from the plurality of electrodes to the power supply unit.

[0161] A method for controlling a dryer according to one embodiment of the present disclosure may further include matching the impedance of the power supply unit with the impedance of each of the plurality of electrodes.

[0162] Matching the impedance of the power supply unit and the impedance of each of the plurality of electrodes may include matching the impedance of the power supply unit and the impedance of each of the plurality of electrodes based on whether a voltage for determining the impedance balance of the multi-phase circuit exceeds a reference voltage or whether power flows back to the power supply unit from the plurality of electrodes.

[0163] Meanwhile, the disclosed embodiments may be implemented in the form of a recording 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. The recording medium may be implemented as a computer-readable recording medium.

[0164] Computer-readable storage media include all types of storage media that store instructions that can be deciphered by a computer. Examples include read-only memory (ROM), random access memory (RAM), magnetic tape, magnetic disks, flash memory, and optical data storage devices.

[0165] Additionally, a computer-readable recording 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.

[0166] 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 recording 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 on a machine-readable recording medium, such as the memory of a manufacturer's server, an application store's server, or an intermediary server.

[0167] 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 for receiving the dried material; A plurality of electrodes spaced apart from each other on the outside of the drum; A multi-phase circuit including a power supply unit for applying voltage to the plurality of electrodes; and A control unit that controls the power supply unit so that a voltage of one phase among the multi-phase voltages is applied to each of the plurality of electrodes, and voltages of different phases are applied between two adjacent electrodes; The above control unit, A dryer that controls the phase of the voltage applied to at least one of the plurality of electrodes based on whether the voltage for determining the impedance balance of the multi-phase circuit exceeds the reference voltage or whether power flows back from the plurality of electrodes to the power supply unit.

2. In paragraph 1, The above control unit, A dryer that controls the phase of a voltage applied to at least one of the plurality of electrodes so that the voltage for determining the impedance balance of the multi-phase circuit exceeds a reference voltage or becomes lower than the reference voltage based on the reverse flow of power from the plurality of electrodes to the power supply unit.

3. In paragraph 2, The above control unit, A dryer which adjusts the phase of the voltage applied to at least one of the plurality of electrodes so that the voltage for determining the impedance balance of the multi-phase circuit becomes lower than or equal to a reference voltage, and then adjusts the phase of the voltage applied to at least one of the plurality of electrodes based on whether the voltage for determining the impedance balance of the multi-phase circuit exceeds the reference voltage or whether power flows back from the plurality of electrodes to the power supply unit.

4. In paragraph 2, The above control unit, A dryer for obtaining a voltage for judging the impedance balance of the multi-phase circuit by using the impedance of each phase of the multi-phase circuit.

5. In paragraph 4, The above multi-phase circuit, The power supply unit further includes a coupler for detecting a high-frequency signal generated to apply voltage to the plurality of electrodes; The above control unit, A dryer that obtains the impedance of each phase of the multi-phase circuit by using the high-frequency signal detected by the coupler.

6. In paragraph 1, The above multi-phase circuit, A dryer further comprising a phase converter for converting the phase of voltage applied to the plurality of electrodes.

7. In paragraph 6, The above control unit, A dryer that controls the phase converter so that the phase of the voltage applied to the plurality of electrodes is changed based on whether the voltage for determining the impedance balance of the multi-phase circuit exceeds the reference voltage or whether power flows back from the plurality of electrodes to the power supply unit.

8. In paragraph 1, The above control unit, A dryer that controls the magnitude and phase of the voltage applied to at least one of the plurality of electrodes based on whether the voltage for determining the impedance balance of the multi-phase circuit exceeds the reference voltage or whether power flows back from the plurality of electrodes to the power supply unit.

9. In paragraph 1, The above multi-phase circuit, A dryer further comprising a matching circuit that matches the impedance of the power supply unit and the impedance of each of the plurality of electrodes.

10. In paragraph 9, The above control unit, A dryer that controls the matching circuit so that the impedance of the power supply unit and the impedance of each of the plurality of electrodes are matched based on whether the voltage for determining the impedance balance of the multi-phase circuit exceeds the reference voltage or whether power flows back from the plurality of electrodes to the power supply unit.

11. A method for controlling a dryer including a multi-phase circuit including a drum for accommodating a drying material, a plurality of electrodes spaced apart from each other on the outside of the drum, and a power supply unit for applying voltage to the plurality of electrodes, The power supply unit is controlled so that a voltage of one phase among the multi-phase voltages is applied to each of the plurality of electrodes, and voltages of different phases are applied between two adjacent electrodes. A control method for a dryer, comprising: adjusting the phase of a voltage applied to at least one of the plurality of electrodes based on whether the voltage for determining the impedance balance of the multi-phase circuit exceeds a reference voltage or whether power flows back from the plurality of electrodes to the power supply unit.

12. In paragraph 11, Adjusting the phase of the voltage applied to at least one of the plurality of electrodes based on whether the voltage for determining the impedance balance of the multi-phase circuit exceeds the reference voltage or whether power flows back from the plurality of electrodes to the power supply unit; A method for controlling a dryer, comprising: adjusting the phase of a voltage applied to at least one of the plurality of electrodes so that the voltage for determining the impedance balance of the multi-phase circuit exceeds a reference voltage or becomes lower than the reference voltage based on the reverse flow of power from the plurality of electrodes to the power supply unit.

13. In paragraph 12, Adjusting the phase of the voltage applied to at least one of the plurality of electrodes based on whether the voltage for determining the impedance balance of the multi-phase circuit exceeds the reference voltage or whether power flows back from the plurality of electrodes to the power supply unit; A control method for a dryer, comprising: adjusting the phase of a voltage applied to at least one of the plurality of electrodes so that the voltage for determining the impedance balance of the multi-phase circuit becomes lower than or equal to a reference voltage; and then adjusting the phase of the voltage applied to at least one of the plurality of electrodes based on whether the voltage for determining the impedance balance of the multi-phase circuit exceeds the reference voltage or whether power flows back from the plurality of electrodes to the power supply unit.

14. In paragraph 12, A control method for a dryer, further comprising: obtaining a voltage for determining the impedance balance of the multi-phase circuit by using the impedance of each phase of the multi-phase circuit.

15. In paragraph 14, The above multi-phase circuit, In a control method of a dryer, the power supply unit further includes a coupler for detecting a high-frequency signal generated to apply voltage to the plurality of electrodes, A control method for a dryer, further comprising: obtaining impedance of each phase of the multi-phase circuit by using the high-frequency signal detected by the coupler.

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