Dryer and control method therefor

Abstract

This dryer comprises: a motor for providing rotational force to a compressor; an inverter including a single shunt structure composed of a plurality of switches and one resistor, and supplying driving power to the motor; and one or more processors for controlling the inverter so that the motor rotates at a preset speed, wherein the one or more processors check an operation section of the motor, generate a control signal in a first control method when the operation section of the motor is a forced align section in which a rotor in the motor is disposed at a preset position, generate a control signal in a second control method different from the first control method when the operation section of the motor is not the forced align section, and provide the generated control signal to the plurality of switches.

Description

Dryer and control method thereof

[0001] The present disclosure relates to a dryer capable of controlling an inverter by changing the inverter control method according to the operating range of the motor, and a method for controlling the same.

[0002] A dryer is a device that dries items, such as clothing and bedding, by supplying high-temperature (or dry) hot air into the drum while the drum containing the items rotates.

[0003] The dryer dries the material to be dried by carrying out a drying process that supplies dry air into the drum. This dry air is generated using a compressor, which is operated by a drive unit comprising a motor and an inverter that provides driving power to the motor.

[0004] The embodiments of the present disclosure may solve at least one of the previously described problems and / or disadvantages and provide the advantages described below. Accordingly, the embodiments of the present disclosure provide a dryer and a method for controlling the same, which can control the inverter by changing the inverter control method according to the motor's operating range.

[0005] Additional embodiments will be presented in the detailed description below, some of which are obvious from the detailed description, and other embodiments can also be presented through learning from the presented embodiments.

[0006] A dryer according to an embodiment of the present disclosure is disclosed. The dryer comprises a motor that provides rotational force to a compressor, a single shunt structure composed of a plurality of switches and a single resistor, an inverter that supplies driving power to the motor, and one or more processors that control the inverter so that the motor rotates at a preset speed. The one or more processors identify an operating section of the motor, and if the operating section of the motor is a forced alignment section in which a rotor within the motor is placed at a preset position, generate a control signal using a first control method, and if the operating section of the motor is not a forced alignment section, generate a control signal using a second control method different from the first control method, and provide the generated control signal to the plurality of switches.

[0007] The above inverter may include first to third switches, each having one end commonly connected to a DC power source and the other end individually connected to one of the plurality of terminals of the motor, and fourth to sixth switches, each having one end individually connected to one terminal of the motor and the other end connected to the resistor.

[0008] The above one or more processors can check the current flowing through each phase of the motor and generate a driving signal for the plurality of switches based on the current magnitude of each phase checked and the first control method.

[0009] The above one or more processors can measure the voltage value of the resistor at two different points in time within one cycle to determine the current magnitude of the two phases of the motor, and calculate the current magnitude of the remaining phase based on the two determined current magnitudes.

[0010] The above one or more processors can adjust the trigger timing of the driving signal for the plurality of switches so that the maintenance time of the switch state at the time of checking the voltage value of the resistor is greater than or equal to a preset minimum time.

[0011] The above one or more processors can adjust the trigger timing of the driving signal so that each of the first interval in which the first switch is turned on, the second switch is turned off, and the third switch is turned off, and the second interval in which the first switch and the second switch are turned on and the third switch is turned off, is greater than or equal to the minimum time.

[0012] The first control method above is a method of modulating the three-phase command voltage through a spatial vector in complex space, and the second control method above may be a method of not performing switching control for the plurality of switches within a preset 120-degree interval within one cycle.

[0013] The first control method above is a Space Vector PWM (SVPWM) method, and the second control method above may be a 120-degree Discontinuous PWM (DPWM).

[0014] The dryer may further include a second motor that rotates the drum and a second inverter that provides driving power to the second motor.

[0015] One or more processors above may identify a forced alignment section if, after a driving command for the motor is input, the reference voltage for the motor is less than or equal to a preset size.

[0016] The above one or more processors can switch the control method from the first control method to the second control method when the operating section of the motor is switched from the forced alignment section to the acceleration section.

[0017] A control method for a dryer having an inverter that provides three-phase driving power to a motor using a single shunt structure composed of a plurality of switches and a single resistor according to one embodiment of the present disclosure includes the steps of: checking the operating section of the motor; generating a control signal using a first control method if the operating section of the motor is a forced alignment section in which a rotor within the motor is placed at a preset position; generating a control signal using a second control method different from the first control method if the operating section of the motor is not a forced alignment section; and providing the generated control signal to the plurality of switches.

[0018] The present control method includes a step of checking the current flowing through each phase of the motor, and the step of generating a driving signal using the first control method can generate a driving signal for the plurality of switches based on the current magnitude of each phase checked and the first control method.

[0019] The step of verifying the current can be performed by measuring the voltage value of the resistor at two different points within one cycle to verify the current of the two phases of the motor, and calculating the magnitude of the current of the remaining phase based on the two verified currents.

[0020] The step of generating a driving signal using the first control method above can adjust the trigger timing of the driving signal for the plurality of switches so that the maintenance time of the switch state at the time of checking the voltage value of the resistor is greater than or equal to a preset minimum time.

[0021] The above plurality of switches includes first to third switches at the top, and the step of generating a driving signal in the first control method can adjust the trigger timing of the driving signal so that the first section in which the first switch is turned on, the second switch is turned off, and the third switch is turned off, and the second section in which the first switch and the second switch are turned on and the third switch is turned off are greater than or equal to the minimum time.

[0022] The above verification step can be checked as a forced alignment section if, after a driving command for the motor is input, the reference voltage for the motor is less than or equal to a preset size.

[0023] The step of generating a control signal using the second control method described above can switch the control method to the second control method when the operating section of the motor switches from the forced alignment section to the acceleration section.

[0024] A home appliance according to one embodiment of the present disclosure comprises a single shunt structure composed of a motor, a plurality of switches, and a single resistor, an inverter that supplies driving power to the motor, and one or more processors that control the inverter so that the motor rotates at a preset speed, wherein the one or more processors identify an operating section of the motor, and if the operating section of the motor is a forced alignment section in which a rotor within the motor is placed at a preset position, generate a control signal using a first control method, and if the operating section of the motor is not a forced alignment section, generate a control signal using a second control method different from the first control method, and provide the generated control signal to the plurality of switches.

[0025] One or more processors above can identify a forced alignment section when a driving command for the motor is input and the reference voltage for the motor is less than or equal to a preset size.

[0026] The above-described or other aspects, features, and benefits of embodiments of the present disclosure will become more apparent from the following description with reference to the accompanying drawings. In the accompanying drawings:

[0027] FIG. 1 is a perspective view of a dryer according to one embodiment of the present disclosure,

[0028] FIG. 2 is a block diagram illustrating the configuration of a dryer according to one embodiment of the present disclosure,

[0029] FIG. 3 is a block diagram illustrating the configuration of a dryer according to one embodiment of the present disclosure,

[0030] FIG. 4 is a circuit diagram illustrating the configuration of an inverter having three shunts according to one embodiment of the present disclosure.

[0031] FIG. 5 is a drawing for explaining an SVPWM method according to one embodiment of the present disclosure,

[0032] FIG. 6 is a drawing for explaining a DPWM method according to one embodiment of the present disclosure,

[0033] FIG. 7 is a circuit diagram illustrating the configuration of an inverter having a single shunt according to one embodiment of the present disclosure.

[0034] FIG. 8 is a drawing for explaining the adjustment of the switch timing when having the configuration of FIG. 7,

[0035] FIG. 9 is a waveform diagram for explaining the current waveform of the forced alignment section in an inverter having a single shunt,

[0036] FIG. 10 is a diagram illustrating an example of a control signal when the DPWM method is applied to an inverter having a single shunt.

[0037] FIG. 11 is a diagram showing the current waveform of each phase of the motor in the case of FIG. 10.

[0038] FIG. 12 is a diagram illustrating an example of a control signal when the SVPWM method is applied to an inverter having a single shunt.

[0039] FIG. 13 is a diagram showing the current waveform of each phase of the motor in the case of FIG. 12, and,

[0040] FIG. 14 is a flowchart illustrating a method for controlling a dryer according to one embodiment of the present disclosure.

[0041] The embodiments described herein are subject to various modifications and may have various forms; specific embodiments are illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the scope of specific embodiments and should be understood to include various modifications, equivalents, and / or alternatives of the embodiments of the present disclosure. In relation to the description of the drawings, similar reference numerals may be used for similar components.

[0042] In describing the present disclosure, if it is determined that a detailed description of related known functions or configurations could unnecessarily obscure the essence of the present disclosure, such detailed description is omitted.

[0043] Additionally, the following embodiments may be modified in various other forms, and the scope of the technical concept of the present disclosure is not limited to the following embodiments. Rather, these embodiments are provided to make the present disclosure more faithful and complete and to fully convey the technical concept of the present disclosure to those skilled in the art.

[0044] The terms used in this disclosure are used merely to describe specific embodiments and are not intended to limit the scope of the rights. The singular expression includes the plural expression unless the context clearly indicates otherwise.

[0045] In the present disclosure, expressions such as “have,” “may have,” “include,” or “may include” indicate the presence of such features (e.g., numerical values, functions, actions, or components, etc.) and do not exclude the presence of additional features.

[0046] In the present disclosure, expressions such as “A or B,” “at least one of A or / and B,” or “one or more of A or / and B” may include all possible combinations of items listed together. For example, “A or B,” “at least one of A and B,” or “at least one of A or B” may refer to cases including (1) at least one A, (2) at least one B, or (3) both at least one A and at least one B.

[0047] Expressions such as “first,” “second,” “first,” or “second” used in this disclosure may modify various components regardless of order and / or importance, and are used only to distinguish one component from another and do not limit said components.

[0048] Where it is stated that a component (e.g., a first component) is "(operatively or communicatively) coupled with / to" or "connected to" another component (e.g., a second component), it should be understood that the component may be directly connected to the other component or connected through the other component (e.g., a third component).

[0049] On the other hand, when it is stated that a certain component (e.g., a first component) is "directly connected" or "directly coupled" to another component (e.g., a second component), it may be understood that no other component (e.g., a third component) exists between said certain component and said other component.

[0050] As used in this disclosure, the expression “configured to” may be replaced, depending on the context, with, for example, “suitable for,” “having the capacity to,” “designed to,” “adapted to,” “made to,” or “capable of.” The term “configured to” may not necessarily mean only “specifically designed to” in hardware.

[0051] Instead, in some situations, the expression “device configured to do something” may mean that the device is “capable of doing something” together with other devices or components. For example, the phrase “processor configured (or set) to perform A, B, and C” may mean a dedicated processor for performing the said operation (e.g., an embedded processor), or a generic-purpose processor (e.g., a CPU or application processor) capable of performing the said operation by executing one or more software programs stored in a memory device.

[0052] In the embodiments, a 'module' or 'part' performs at least one function or operation and may be implemented in hardware or software, or a combination of hardware and software. Additionally, a plurality of 'modules' or a plurality of 'parts' may be integrated into at least one module and implemented by at least one processor, except for the 'module' or 'part' that needs to be implemented in specific hardware.

[0053] Operations performed by a module, program, or other component according to various embodiments may be executed sequentially, in parallel, iteratively, or heuristically, or at least some operations may be executed in a different order, omitted, or other operations may be added.

[0054] Meanwhile, various elements and areas in the drawings are depicted schematically. Accordingly, the technical concept of the present disclosure is not limited by the relative sizes or spacing depicted in the attached drawings.

[0055] Meanwhile, an electronic device according to various embodiments of the present disclosure may include, for example, at least one of a smartphone, a tablet PC, a desktop PC, a laptop PC, a server, or a wearable device. The wearable device may include at least one of an accessory type (e.g., a watch, ring, bracelet, anklet, necklace, glasses, contact lens, or head-mounted device (HMD)), a fabric or clothing integrated type (e.g., electronic clothing), a body-attached type (e.g., a skin pad or tattoo), or a bio-implantable circuit.

[0056] In some embodiments, the electronic device is, for example, a television, a DVD (digital video disk) player, an audio device, a refrigerator, an air conditioner, a dehumidifier, a vacuum cleaner, an oven, a microwave oven, a washing machine, an air purifier, a set-top box, a home automation control panel, a security control panel, a media box (e.g., Samsung HomeSync). TMIt may include at least one of a game console, an electronic dictionary, an electronic key, a camcorder, or an electronic photo frame. Meanwhile, among the electronic devices described above, a device equipped with a motor may be referred to as a home appliance.

[0057] For example, home appliances may include washing machines, dryers, refrigerators, dehumidifiers, vacuum cleaners, water purifiers, air conditioners, etc. Although the present disclosure is described below assuming it is applied to a dryer, as described above, it may be applied not only to dryers but also to other electronic devices equipped with a three-phase motor (or compressor).

[0058] Hereinafter, embodiments according to the present disclosure are described in detail with reference to the attached drawings so that those skilled in the art can easily implement them.

[0059] FIG. 1 is a perspective view of a dryer according to one embodiment of the present disclosure.

[0060] A dryer according to one embodiment of the present disclosure can perform a drying process. The dryer is a device for drying clothes, as an example of a clothing processing device. Such a dryer may perform not only the function of drying clothes but also the function of washing clothes. Such a dryer may be referred to as a washing machine or a washing machine.

[0061] Referring to FIG. 1, the dryer (100) may include a housing (10) that accommodates various components inside. The housing (10) may be provided in the form of a box with a drying opening formed on one side.

[0062] The housing (10) may include an upper cover (11), a front panel, and a rear panel. The front of the housing (10) may include a door (13) for opening and closing a drying opening. The door (13) may be rotatably mounted to the housing (10) by means of a hinge. At least a portion of the door (13) may be made transparent or translucent so that the interior of the housing (10) is visible.

[0063] A dryer (100) may include a drum provided to accommodate a drying material. The drum may be positioned inside a tub such that a drum opening provided on one side corresponds to a drying material inlet and a tub opening. The drying material may pass through the drying material inlet, the tub opening, and the drum opening in sequence to be accommodated inside the drum or withdrawn from the drum. The drum may rotate inside the tub.

[0064] The dryer (100) may include a heat exchanger to provide high-temperature dry air. The heat exchanger can heat the air supplied to the drum. The high-temperature, high-humidity air that has passed through the inside of the drum can be recirculated to the heat exchanger along the inlet path. The high-temperature, dry air that has passed through the heat exchanger can be discharged back into the inside of the drum along the outlet path and circulated.

[0065] This air circulation can be induced by a blower fan installed on the inlet side. For example, hot and humid air discharged from the drum can be introduced into the heat exchanger through the blower fan.

[0066] A heat exchanger may include an evaporator and a condenser. High-temperature, high-humidity air can pass through the evaporator. A refrigerant that absorbs heat by expanding due to a pressure drop may flow inside the evaporator. As the refrigerant evaporates in the evaporator, it absorbs heat, and the high-temperature, high-humidity air passing through it cools down, loses moisture, and becomes low-temperature, dry air. In other words, the high-temperature, high-humidity air discharged from the drum is transformed into low-temperature, dry air as it passes through the evaporator.

[0067] Low-temperature dry air that has passed through the evaporator can pass through the condenser. Inside the condenser, refrigerant that has been compressed and superheated by the compressor can flow. As the superheated refrigerant flows through the condenser, it releases heat, and the low-temperature dry air passing through the condenser is heated to become high-temperature dry air. In other words, the low-temperature dry air that has passed through the evaporator changes into high-temperature dry air as it passes through the condenser.

[0068] The dryer (100) may include a driving device that rotates the compressor described above. The driving device may include a motor that provides driving force to the compressor and an inverter that provides driving power to the motor described above. For example, the motor that rotates the compressor may be a three-phase motor.

[0069] The inverter includes a plurality of switches and can generate three-phase power according to a combination of the operating states of each of the plurality of switches. The configuration and operation of the plurality of switches within the inverter will be described later in FIGS. 4 and FIGS. 7.

[0070] When the drying process begins, the second drive unit operates, thereby enabling the drum and the blower fan to operate. The blower fan generates airflow. The air then passes through a heat exchanger, transforming into high-temperature, dry air, which can then flow into the drum.

[0071] The hot, dry air introduced into the drum removes moisture from the object to be dried contained inside the drum (30) and dries the object to be dried. At the same time, the air changes into hot, humid air. The hot, humid air flows back into the heat exchanger along the inlet path and can change into hot, dry air in the heat exchanger. This hot, dry air can be introduced back into the drum.

[0072] The dryer (100) may include a control panel (12) disposed on one side of the housing (10). The control panel (12) may provide a user interface for the user to interact with the dryer. The user interface may include at least one input interface (160) and at least one output interface (170). The input interface and the output interface will be described later in FIG. 3.

[0073] Energy efficiency is important for a dryer (100) in that a large amount of energy is used during the drying process. Accordingly, the dryer (100) generally controls the inverter using a 120-degree DPWM (Discontinuous PWM) method, which reduces the amount of heat generated by the switching element in the inverter and thus has high efficiency.

[0074] Recently, in order to reduce the size of the inverter circuit, there have been attempts to change from a 3-shunt structure to a single-shunt structure. Here, the 3-shunt structure is a structure in which each arm within the inverter is grounded through a separate resistor, and the single-shunt structure is a structure in which multiple arms are grounded through a single resistor. The 3-shunt structure will be described later in FIG. 4, and the single-shunt structure will be described later in FIG. 7.

[0075] However, if the structure is changed to a single shunt, significant abnormal noise occurs during the initial operation of the dryer. The causes of this problem and solutions will be described later in FIGS. 8 and 9.

[0076] To solve these problems, the present disclosure controls the operation of the inverter using a first control method during the initial operation of the compressor (i.e., when a motor start command is input, and during the forced alignment section, the operation of the inverter is controlled using a second control method during the subsequent section).

[0077] Here, the first control method is a Space Vector PWM (SVPWM) method, which modulates the three-phase command voltage through a space vector in complex space. The detailed operation of the first control method is described later in FIG. 5.

[0078] The second control method is a 120-degree DPWM (Discontinuous PWM) that does not perform switching control for multiple switches within a preset 120-degree interval within a single cycle. The detailed operation of the second control method is described later in FIG. 6.

[0079] Meanwhile, although the illustrated example describes the configuration and operation of the present disclosure assuming that they are applied to a dryer, in practice, they can be applied not only to dryers but also to any device that uses a three-phase motor. In particular, they can be applied to refrigerators, water purifiers, dehumidifiers, air conditioners, etc., that drive a compressor using a three-phase motor.

[0080] FIG. 2 is a block diagram illustrating the configuration of a dryer according to one embodiment of the present disclosure.

[0081] Referring to FIG. 2, the dryer (100) may include a motor (110), an inverter (120), and a processor (130).

[0082] The motor (110) provides rotational force to the compressor. For example, the motor (110) can provide rotational force to the compressor when the drying process starts.

[0083] Such a motor may be a three-phase motor operating on a three-phase power supply. Meanwhile, although the illustrated example assumes that rotational force is provided to a compressor, rotational force may also be provided to a drum during implementation. Such a three-phase motor can divide its operating sections into a forced alignment section, an acceleration section, and a constant speed section.

[0084] Here, the forced alignment section is the period in which the rotor within the motor is positioned at a specific location (or specific phase), the acceleration section is the period in which the motor speed increases (or decreases), and the constant speed section is the period in which a specific speed is maintained. Each of these sections can be distinguished based on the magnitude of the reference voltage, or based on the motor speed or driving time.

[0085] The inverter (120) provides three-phase driving power to the motor using a plurality of switches. For example, the inverter can generate and provide three-phase driving power to the motor using six switches. These switches may be IGBTs (Insulated Gate Bipolar Transistors), MOSFETs (metal-oxide-semiconductor field-effect transistors), etc.

[0086] The inverter (120) may operate based on the SVPWM (Space Vector PWM) method or the 120-degree DPWM (Discontinuous PWM) method. For example, the inverter (120) may operate in the SVPWM method up to a certain speed (or below a preset target voltage) at the initial stage of driving the compressor, and then operate in the 120-degree DPWM method thereafter. Meanwhile, although the present disclosure assumes the 120-degree DPWM method, other types of DPWM methods may be used depending on the application environment or if they have higher operating efficiency than the 120-degree DPWM.

[0087] Meanwhile, an IPM including an inverter can be used for implementation. An IPM (Intelligent Power Module) is an intelligent power module that is a power module capable of performing self-protection functions along with the inverter function described above.

[0088] For example, the IPM can also perform overheat protection, short-circuit protection, overcurrent protection, and control power abnormality protection functions, and can output a fault signal when the aforementioned protection functions are activated. Although the dryer is described below as being equipped with an inverter, the illustrated inverter may be replaced with an IPM.

[0089] The processor (130) controls the overall operation of the dryer (100). Specifically, the processor (130) is connected to the configuration of the dryer including the motor (110) and the inverter (120) and can control the overall operation of the dryer by executing at least one stored instruction. In particular, the processor (130) can be implemented as a single processor as well as as a plurality of processors.

[0090] The processor (130) may be implemented as one or more IC (integrated circuit (or circuitry)) chips and may perform various data processing operations. The processor (130) may include at least one electrical circuit and may process instructions (or programs, data, etc.) stored in memory individually or collectively in a distributed manner.

[0091] The processor (130) may include a processor assembly comprising one or more processing circuits. The processor (130) may include any processing circuit that is operative to control the performance and operation of one or more components of the dryer (e.g., memory and / or drive unit (sensor)). For example, the processor (130) (e.g., AP) may be implemented as a system on chip (SoC) (e.g., a single chip or a chipset). For example, the processor (130) may be implemented as multiple cores (or at least one core circuit), multiple chips, or multiple chipsets.

[0092] For example, the processor (130) may include one or more processing circuits. The processor (130) may include one or more processing circuits configured to perform various functions of the present disclosure individually and / or collectively. As an example without limitation, at least a portion of the processor (130) may be included in a first chip of the dryer (100), and at least another portion of the processor (130) may be included in a second chip of a dryer different from the first chip of the dryer (100).

[0093] For example, the processor (130) may include a central processing unit (CPU), a graphics processing unit (GPU), a neural processing unit (NPU), an image signal processor (ISP), a display controller, a memory controller, a storage controller, a communication processor (CP), and / or a sensor interface. These components of the processor (130) are merely exemplary. The processor (130) may include additional components other than those described above. Additionally, some components of the processor (130) may be omitted. Furthermore, some components of the processor (130) may be included as separate components of the dryer (100) outside of the processor (130). For example, some components of the processor (130) (e.g., a memory controller) may be included within other components (e.g., at least a portion of memory, an interface (e.g., available for connection to at least one component of the dryer (100)), a display).

[0094] The processor (130) can cause other components of the dryer (100) to perform various operations by executing instructions stored in the dryer. The processor (130) processes setting values, function commands, etc. according to a stored control program or control data, and can output control signals related to functions that the dryer (100) can perform or communication signals for communicating with an external electronic device.

[0095] The processor (130) can control the inverter (120) based on the input drying course. For example, when information about the drying course is input, the processor (130) can control the inverter (120) to proceed with the drying operation according to the input drying course.

[0096] For example, the processor (130) can operate by determining the drying temperature and drying time according to the drying course (e.g., the type and weight of the material to be dried).

[0097] If the processor (130) needs to start a drying process, it first controls the inverter to operate using a first control method, and, for example, if the inverter is in a forced alignment section, it can operate using an SVPWM method. Afterwards, if the target voltage of the inverter becomes above a certain voltage and the motor enters a synchronous acceleration or speed control section, it can control the inverter to operate using a second control method.

[0098] The processor (130) can check the operating section of the motor. For example, the processor (130) can consider a situation where a drying start command is input and the rotor inside the motor is positioned at a specific location as a forced alignment section.

[0099] Meanwhile, during implementation, the processor (130) may identify the motor as a forced alignment section or a section operating in the first control method described later if the reference voltage is less than or equal to a preset size, and may identify it as a section operating in the second control method if it exceeds a preset size.

[0100] Additionally, when a control command to control the motor is input to the processor (130), the processor (130) can control the rotor of the motor to be positioned at a specific location for a certain period of time after the input control command. By utilizing this certain period of time, the processor (130) can identify the aforementioned certain period of time as a forced alignment section or a section operating in the first control method. Conversely, the processor (130) can identify the aforementioned certain period of time as an acceleration section or a constant speed section, or a section operating in the second control method.

[0101] And if the processor (130) is in the process of rotating the motor, the motor can be identified as an acceleration section or a speed control section.

[0102] Meanwhile, although the above description explains that the motor is divided into a forced alignment section and a remaining section that is not, in implementation, the motor operation section described above may be distinguished based on whether the target voltage of the inverter is below a preset voltage or above a preset voltage. Alternatively, the space within the space vector for controlling the inverter may be distinguished based on whether it is within the hatching area within the space illustrated in FIG. 8 or an external space.

[0103] When the operating section is identified, the processor (130) can control the inverter to operate in a control method corresponding to the identified operating section. For example, if the processor (130) needs to drive the motor, it can first control the motor in a first control method, and if it is confirmed that the motor has moved out of the forced alignment section, it can switch the control method to a second control method.

[0104] At this time, the processor (130) can check the current magnitude of the driving voltage in each cycle and generate a control signal for each switch in the inverter based on the checked current magnitude.

[0105] For example, if each arm (or leg) in the inverter is grounded with an individual resistor, that is, if it is a 3-shunt structure, the processor (130) can easily measure the current of each arm (or phase) through the individual resistor.

[0106] Conversely, if each arm in the inverter is grounded through a single resistor, that is, if it is a single shunt structure, the processor (130) must measure the voltage value of the single resistor at multiple times within one cycle to determine the current for each phase of the motor.

[0107] For example, the processor (130) can measure the voltage value of the resistor at two different points within one cycle to determine the current magnitude of the two phases of the motor and calculate the current magnitude of the remaining phase based on the two determined current magnitudes.

[0108] Meanwhile, since the current fluctuates significantly instantaneously when the inverter switch is turned on or off, the measurement described above must be performed after the current signal has stabilized.

[0109] To this end, the processor (130) can adjust the trigger timing of the driving signals for a plurality of switches so that the maintenance time of the switch state at the time of checking the voltage value of the resistor is greater than or equal to a preset minimum time. Such timing may be a first interval in which the first switch is turned on, the second switch is turned off, and the third switch is turned off, and a second interval in which the first switch and the second switch are turned on, and the third switch is turned off. Here, the trigger timing may be referred to as the turn-on time or the turn-off time.

[0110] The timing of current measurement during such a single shunt is explained in more detail in Figures 8 and 10.

[0111] As described above, the dryer according to the present disclosure operates in a manner that reduces noise generation during the initial stage of the drying function and subsequently operates in a manner that is highly energy efficient, thereby enabling the reduction of noise while increasing energy efficiency.

[0112] Meanwhile, although only a simple configuration constituting the dryer (100) has been illustrated and described above, various additional configurations may be provided during implementation. This will be explained below with reference to FIG. 3.

[0113] FIG. 3 is a block diagram illustrating the configuration of a dryer according to one embodiment of the present disclosure.

[0114] Referring to FIG. 3, the dryer (100) may include a motor (110), an inverter (120), a processor (130), a memory (140), a communication interface (150), an input interface (160), an output interface (170), a sensor (180), a second motor (191), and a second inverter (193).

[0115] The configuration of the motor (110) and processor (130) was previously described in FIG. 2, and only the operation different from FIG. 2 will be described below.

[0116] The inverter (120) can be configured as an IPM. When configured as an IPM, it can perform not only the basic functions of the inverter described above, but also a self-protection function.

[0117] For example, the inverter (120) can operate in an SVPWM or DPWM manner to check for overcurrent, overheating, short circuits, etc. in the motor. And if such abnormalities are detected, it can output a fault signal. Meanwhile, the fault signal can be detected by the processor (130), and if the fault signal is detected, it is determined that motor stopping is required and motor braking can be performed.

[0118] The memory (140) may be implemented as internal memory such as ROM (e.g., EEPROM (electrically erasable programmable read-only memory)) or RAM included in the processor (130), or as memory separate from the processor (130). In this case, the memory (140) may be implemented in the form of memory embedded in the dryer (100) or in the form of memory that can be attached to and detached from the dryer (100), depending on the purpose of data storage. For example, data for operating the dryer (100) may be stored in memory embedded in the dryer (100), and data for the expansion function of the dryer (100) may be stored in memory that can be attached to and detached from the dryer (100).

[0119] Meanwhile, the memory embedded in the dryer (100) is implemented as at least one of volatile memory (e.g., DRAM (dynamic RAM), SRAM (static RAM), or SDRAM (synchronous dynamic RAM), non-volatile memory (e.g., OTPROM (one time programmable ROM), PROM (programmable ROM), EPROM (erasable and programmable ROM), EEPROM (electrically erasable and programmable ROM), mask ROM, flash ROM, flash memory (e.g., NAND flash or NOR flash), hard drive, or solid state drive (SSD), and the memory that can be attached to and detached from the dryer (100) can be implemented in the form of a memory card (e.g., CF (compact flash), SD (secure digital), Micro-SD (micro secure digital), Mini-SD (mini secure digital), xD (extreme digital), MMC (multi-media card), etc.), external memory that can be connected to a USB port (e.g., USB memory).

[0120] Meanwhile, although the dryer (100) is depicted as being composed of a single memory in the illustrated example, when distinguishing between volatile memory and non-volatile memory, the dryer (100) may be described as including multiple memories.

[0121] The memory (140) may store time information required for the drying course or inverter driving method (or motor rotation speed information). According to one example, there may be a drying course corresponding to each of a plurality of operating modes.

[0122] The memory (140) can store information regarding whether the inverter is faulty, etc. If a user drying command is input while there is fault information (or a fault flag), the processor (130) can control the output interface (170) to notify the user that drying cannot be performed.

[0123] The communication interface (150) includes a circuitry. The communication interface (150) can perform data communication with other electronic devices under the control of the processor (130). Here, the electronic devices may include a server, a home appliance, a mobile device (e.g., a user terminal device such as a smartphone, a tablet PC, or a wearable device).

[0124] For example, the communication interface (150) may include a communication circuit capable of performing data communication between the dryer (100) and an electronic device using at least one of the data communication methods including wired LAN, wireless LAN, Wi-Fi, Wi-Fi Direct, Bluetooth, ZigBee, WFD (Wi-Fi Direct), infrared communication (IrDA, infrared Data Association), BLE (Bluetooth Low Energy), NFC (Near Field Communication), Wibro (Wireless Broadband Internet), WiMAX (World Interoperability for Microwave Access), SWAP (Shared Wireless Access Protocol), WiGig (Wireless Gigabit Alliances, WiGig), and RF communication.

[0125] The communication interface (150) can transmit fault information to a server or user terminal device. For example, if a short circuit occurs in a switch element within the inverter, the processor (130) can transmit fault information to a server or user terminal device, etc., to notify a user or manager of such fault.

[0126] The input interface (160) can receive user input and transmit the user input to the processor (130). For example, the input interface (160) can receive various user inputs for setting or selecting various functions supported by the dryer (100). For example, the input interface (160) can receive inputs such as the type of item to be dried, the degree of drying, and the reservation time.

[0127] The input interface (160) may include physical buttons. The physical buttons may include a power button, an operation button, a course selection dial (or course selection button), a drying setting button, etc. Such physical buttons may include, for example, a tact switch, a push switch, a slide switch, a toggle switch, a micro switch, a touch switch, a touchpad, a touchscreen, a jog dial, and / or a microphone, etc.

[0128] According to one example, the input interface (160) can receive user input using a touch method. For example, the input interface (160) can be implemented as a touchscreen capable of performing the function of a display (171).

[0129] According to one example, the input interface (160) can receive user voice using a microphone. The processor (130) can perform a function corresponding to the user voice using voice recognition. For example, the processor (130) can convert the user voice into text data using a Speech To Text (STT) function, obtain control command data based on the text data, and perform a function corresponding to the user voice based on the control command data. According to an embodiment, the STT function may be performed on an external server.

[0130] The output interface (170) can visually or audibly convey information related to the operation of the dryer (100) to the user. For example, the output interface can convey information related to the washing course, the operating time of the dryer (100), and the drying settings to the user. Here, information regarding the operation of the dryer (100) can be output via a screen, an indicator, voice, etc.

[0131] This output interface (170) may include a display (171) and a speaker (172).

[0132] The display (171) can display various screens. The processor (130) can display various notifications, messages, information, etc. related to the operation of the dryer (100) on the display (171).

[0133] The display (171) may be implemented as a display including a self-emissive element or as a display including a non-emissive element and a backlight. For example, the display (171) may be implemented as various types of displays such as an LCD (Liquid Crystal Display), an OLED (Organic Light Emitting Diodes) display, an LED (Light Emitting Diodes) display, a micro LED display, a Mini LED display, a QLED (Quantum dot light-emitting diodes) display, etc.

[0134] The speaker (172) can output an audio signal. The processor (130) can output warning sounds, notification messages, response messages corresponding to user input, etc. related to the operation of the dryer (100) through the speaker (172).

[0135] The sensor (180) can detect the operation of various components within the dryer or detect humidity within the drum. For example, the sensor (180) may include a humidity sensor. The humidity sensor is a sensor that detects humidity within the drum. The processor (130) can adjust the drying time based on the humidity detected by the sensor.

[0136] The sensor (180) may include a current sensor that detects the magnitude of the current within the inverter. In implementation, the sensor described above may be implemented through the combination of a resistor connected in series to the lower switch of the inverter and an ADC within the processor. Alternatively, instead of using a separate sensor, the current sensor within the IPM may be used.

[0137] The second motor (191) provides rotational force to the drum. For example, the second motor (191) can rotate the drum (30) in the forward or reverse direction to perform an action corresponding to the stroke according to each function provided by the dryer. Such a motor may be a three-phase motor that operates on a three-phase power supply. Meanwhile, although the compressor and the drum have been illustrated and described above as being operated by different motors, both configurations may be controlled by a single motor during implementation.

[0138] The second inverter (193) provides three-phase driving power to the second motor (191) using a plurality of switches. For example, the inverter can generate and provide three-phase driving power to the motor using six switches. These switches may be IGBTs (Insulated Gate Bipolar Transistors), MOSFETs (metal-oxide-semiconductor field-effect transistors), etc. This second inverter (193) may be configured in a three-shunt form or in a single-shunt form.

[0139] Meanwhile, although FIG. 3 illustrates the dryer (100) as including various configurations, some configurations may be omitted during implementation. Additionally, if the dryer (100) also supports a washing function, configurations such as a water supply device, a drainage device, and a detergent supply device may be added. Furthermore, if the operation of the present disclosure is applied to a home appliance other than the dryer (100), some of the above-described configurations may be applied by adding or omitting configurations suitable for the modified home appliance.

[0140] FIG. 4 is a circuit diagram illustrating the configuration of an inverter having three shunts according to one embodiment of the present disclosure.

[0141] Referring to FIG. 4, the dryer (100) may include a power supply and a driving device.

[0142] The power supply unit receives an external AC power source (50) and converts it into DC power to supply to internal components within the dryer. For example, the power supply unit may include a rectifier circuit (60) and a smoothing circuit (70).

[0143] The rectifier circuit (60) can output only the preset phase of the input AC power. And the smoothing circuit (70) can smooth the rectified power using a capacitor.

[0144] The drive unit provides rotational force to the compressor. For example, the drive unit may include a motor (110) and an inverter (120).

[0145] The motor (110) receives driving power and can provide rotational force to the compressor using the driving power. The motor (110) according to the present disclosure may be a three-phase motor, and accordingly, may receive three-phase driving power through three terminals (a, b, c). Such a motor (110) may be modeled to include a resistor (R) and an inductor (L) inside, as illustrated.

[0146] The inverter (120) can provide driving power to the motor (110). For example, the inverter (120) includes a plurality of switches (121 to 126) and can generate driving power through the switching operation of the plurality of switches and provide it to the motor (110).

[0147] The first switch (121) has one end DC power supply (V dc One end of the motor is connected to the other end of the fourth switch (121), and the other end can be commonly connected to one end of the motor (e.g., terminal a) and one end of the fourth switch (121).

[0148] The second switch (122) has one end DC power supply (V dc One end of the motor is connected to the other end of the motor (e.g., terminal b) and the other end of the fifth switch (125) can be commonly connected to the other end of the motor (e.g., terminal b).

[0149] The third switch (123) has one end DC power supply (V dc One end of the motor is connected to the other end of the sixth switch (126), and the other end can be commonly connected to one end of the motor (e.g., terminal c) and one end of the sixth switch (126).

[0150] One end of the fourth switch (124) is commonly connected to one end of the motor (e.g., terminal a) and the other end of the first switch (121), and the other end can be connected to ground through the first resistor (127). Here, ground may be described as the other end of the power supply or referred to as the negative terminal of the DC link voltage.

[0151] One end of the fifth switch (125) is commonly connected to one end of the motor (e.g., terminal b) and the other end of the second switch (122), and the other end can be connected to ground through the second resistor (128).

[0152] One end of the sixth switch (126) is commonly connected to one end of the motor (e.g., terminal c) and the other end of the third switch (123), and the other end can be connected to ground through the third resistor (129).

[0153] One end of the first resistor (127) is connected to the other end of the fourth switch (124), and the other end can be connected to ground.

[0154] One end of the second resistor (128) is connected to the other end of the fifth switch (125), and the other end can be connected to ground.

[0155] One end of the third resistor (129) is connected to the other end of the sixth switch (126), and the other end can be connected to ground.

[0156] Here, the first to third switches are upper switches, and the fourth to sixth switches are lower switches.

[0157] Meanwhile, in the illustrated example, three resistors (127, 128, 129) are shown connected to the fourth to sixth switches, respectively. That is, the inverter is configured in a three-shunt form, but in implementation, the inverter can also be configured in a single-shunt form using only one resistor. This will be described later in FIG. 7.

[0158] In this way, when using three resistors, the dryer can easily check the current flowing through each phase of the motor by using the voltage of each resistor. Here, 3 shunts refer to resistors connected to each of the three legs (or arms).

[0159] The inverter (120) can generate three-phase power by adjusting the state of the six switches (121 to 126) described above. For example, the upper switch may have approximately six combinations when operating as shown in Table 1 below. Here, Table 1 indicates which phase of the three-phase current the voltage vector output and the current measurement with a single shunt correspond to when a single shunt is applied.

[0160] Meanwhile, the two switches within a single arm (or leg) are not turned on simultaneously, and at least one remains in a turned-off state. That is, although only the state of the upper switch is described in Table 1, the lower switch may have a state opposite to the operation of the upper switch.

[0161] Switching function(S1, S2, S3)DC_link current100Iu110-Iw010Iv011-Iu001IW101-Iv000, 111N / A

[0162] In this way, three-phase power can be generated by adjusting the operating state of six switches, and for proper operation, it is necessary to measure the current flowing through each phase. The inverter (120) can perform control operations on multiple switches based on the measured current. For such control operations in the inverter, a PWM control method can basically be used, and in this disclosure, an SVPWM method and a 120-degree DPWM method are used. First, the SVPWM method will be explained with reference to FIG. 5. Meanwhile, such control operations on multiple switches may be performed internally by the inverter (120) or by control by an external processor. For example, if the inverter (120) is implemented as an IPM, some functions of the processor described above can be performed by the inverter.

[0163] FIG. 5 is a drawing for explaining a first control method according to one embodiment of the present disclosure.

[0164] The SVPWM method is a method of modulating a three-phase command voltage through a spatial vector in complex space, and by using such an SVPWM method, a driving power supply as illustrated in FIG. 5 can be generated. For example, FIG. 5 shows the waveform (510) of the three-phase voltage of the SVPWM method, the three-phase duty cycle (520), and the control signal (530) for each switch.

[0165] First, looking at the waveform (510) of the three-phase voltage, it can be seen that a driving voltage is generated in which the three phases have a phase difference of 120 degrees.

[0166] And if you look at the three-phase duty (520), you can see that the current ripple is small because the deviation of the duty is not large.

[0167] And looking at the control signal (530), it can be seen that all three switches are operating throughout the entire section.

[0168] Meanwhile, as energy efficiency has recently become important, the highly energy-efficient 120-degree DPWM method is being used. Below, the 120-degree DPWM method will be explained with reference to Fig. 6.

[0169] FIG. 6 is a drawing for explaining a second control method according to one embodiment of the present disclosure.

[0170] The 120-degree DPWM method is a control method that does not perform switching control for multiple switches within a preset 120-degree interval within a single cycle. By using such a method, a driving power supply as illustrated in FIG. 6 can be generated. For example, FIG. 6 shows the waveform (610) of the three-phase voltage of the 120-degree DPWM method, the three-phase duty cycle (620), and the control signal (630) for each switch.

[0171] First, looking at the waveform (610) of the three-phase voltage, it can be seen that the DPWM method also generates a driving voltage in which the three phases have a phase difference of 120 degrees.

[0172] However, looking at the control signal (630), it can be seen that each phase does not operate in a specific phase. Specifically, the 120-degree PWM method is a control method in which the three phases alternately remain in the off state by 120 degrees during one 360-degree rotation.

[0173] Since each phase does not switch by 120 degrees, switching loss is reduced and heat generation is reduced. In addition, if the heat generated by the switching element is high, protection control is applied and the dryer performance deteriorates; however, the 120-degree DPWM method can reduce the heat generated by the switching element, thereby improving not only energy efficiency but also drying performance.

[0174] As such, the 120-degree DPWM method is being adopted in dryers for energy efficiency reasons.

[0175] Meanwhile, as home appliances are designed to be more compact and PCB sizes have decreased recently, there are efforts to apply a single-shunt structure to the inverter instead of a three-shunt structure. The single-shunt structure will be explained with reference to Figure 7 below.

[0176] FIG. 7 is a circuit diagram illustrating the configuration of an inverter having a single shunt according to one embodiment of the present disclosure.

[0177] Referring to FIG. 7, the dryer (100) may include a power supply and a driving device. The power supply and motor (110) are identical to the configuration of FIG. 4, so a redundant description is omitted.

[0178] The inverter (120') can provide driving power to the motor (110). For example, the inverter (120') includes a plurality of switches (121 to 126) and a first resistor (127), and can generate three-phase driving power through the switching operation of the plurality of switches.

[0179] The first switch (121) has one end DC power supply (V dc One end of the motor is connected to the other end of the fourth switch (121), and the other end can be commonly connected to one end of the motor (e.g., terminal a) and one end of the fourth switch (121).

[0180] The second switch (122) has one end DC power supply (V dc One end of the motor is connected to the other end of the motor (e.g., terminal b) and the other end of the fifth switch (125) can be commonly connected to the other end of the motor (e.g., terminal b).

[0181] The third switch (123) has one end DC power supply (V dc One end of the motor is connected to the other end of the sixth switch (126), and the other end can be commonly connected to one end of the motor (e.g., terminal c) and one end of the sixth switch (126).

[0182] One end of the fourth switch (124) is commonly connected to one end of the motor (e.g., terminal a) and the other end of the first switch (121), and the other end can be connected to ground through the first resistor (127). Here, ground may be described as the other end of the power supply or referred to as the negative terminal of the DC link voltage.

[0183] One end of the fifth switch (125) is commonly connected to one end of the motor (e.g., terminal b) and the other end of the second switch (122), and the other end can be connected to ground through the first resistor (127).

[0184] One end of the sixth switch (126) is commonly connected to one end of the motor (e.g., terminal c) and the other end of the third switch (123), and the other end can be connected to ground through the first resistor (127) (or common resistor).

[0185] One end of the first resistor (127) is commonly connected to the other end of the fourth switch (124), the other end of the fifth switch (125), and the other end of the sixth switch (126), and the other end can be connected to ground.

[0186] Compared to Fig. 5, it can be seen that the number of resistors connected to the lower switches (124-126) has been reduced from three to one. Previously, current from each arm (or leg) flowed through each resistor, but in Fig. 7, the currents from each arm (or leg) are combined and flow through a single resistor.

[0187] Accordingly, when configuring the inverter in a single shunt form as shown in Fig. 7, in order to measure the current of each phase, the voltage of the resistor must be measured at multiple points within one cycle. For example, the current of two phases can be measured within one PWM cycle, and the current of the remaining phase can be calculated and used.

[0188] Meanwhile, since the current fluctuates significantly instantaneously when the switch is turned on or off, current measurement must be performed after the current has stabilized. In this regard, when a state change occurs in which at least one switch is turned on, the measurement must be performed after a minimum time has passed until the next state change.

[0189] For example, a change in the state of at least one of the multiple switches must occur after a minimum time (T1, T2). Here, the minimum time can be calculated by summing the current stabilization time, dead time, and A / D converter time.

[0190] If the operation transition of the switch is performed while guaranteeing the aforementioned minimum time, no problem occurs. However, there are cases where the state change of the switch is very short in certain intervals. In such cases where the minimum time cannot be secured, the trigger timing of the PWM signal can be adjusted to guarantee the aforementioned minimum time. This will be explained with reference to FIG. 8.

[0191] FIG. 8 is a diagram for explaining the adjustment of the switch timing when having the configuration of FIG. 7.

[0192] Referring to FIG. 8, the left region of FIG. 8 illustrates the output vector space, and the right region illustrates the switch states at three points within the space. In the illustrated example, the operation of sector 1 (i.e., 100) is shown, but it can be similarly applied to other sectors.

[0193] First, when the target command is set to the center position of sector 1, it can be confirmed that the time between the turn-on of the first switch and the turn-on of the next sector is greater than or equal to T1 as described above, and that the time between the turn-on of the third switch after the turn-on of the second switch (S2) is also greater than or equal to T2.

[0194] In such cases, since the current stabilization time is sufficient, there is no need to adjust the turn-on time of the switch for measurement.

[0195] However, when the target command is close to the section boundary, as in the second or third waveform, the trigger timing of the switch may be very close. For example, as in the second waveform, the third turn-on may proceed immediately after the turn-on of the second switch. Or, as in the third waveform, the second switch may turn on immediately after the turn-on of the first switch.

[0196] In cases where transition intervals are adjacent in this manner, the time interval required for the aforementioned current measurement cannot be secured. Therefore, in such cases, for current measurement, the current measurement time can be secured by adjusting at least one of the aforementioned multiple turn-on times (or turn-off times). Additionally, the adjusted time can be compensated for in the latter part of the PWM.

[0197] In this regard, when using an inverter with a single shunt resistor, there was a problem where the motor current ripple increased due to the influence of adjusting the trigger timing (or turn-on timing) of the PWM signal described above.

[0198] In particular, when the inverter is controlled using the DPWM method, the degree of this is very severe, and consequently, noise is generated. This will be explained below with reference to Fig. 9.

[0199] Figure 9 is a diagram showing the waveform of the three-phase current when a driving signal is generated in the DPWM method in an inverter having a single shunt.

[0200] Referring to FIG. 9, three driving currents (a-phase current (910), b-phase current (920), and c-phase current (930)) are shown. For example, the process proceeds stepwise through an alignment section, a synchronous acceleration section, and a speed control section. In the alignment section, it can be seen that among the three phase currents, the b-phase current (920) has a value of 0, the a-phase current (910) gradually increases, and the c-phase current (930) gradually decreases. Also, in the alignment section, it can be seen that each current does not have a constant value, but rather the current value changes with a considerably wide width (or amplitude). That is, it can be seen that the current of each phase has ripple.

[0201] As such, current ripple increases during the alignment section, and consequently, motor noise occurs.

[0202] Meanwhile, since the motor does not rotate during the alignment phase, there is no back EMF, so a small voltage (or target voltage, command voltage) is applied. This controls the system to have a target voltage near the origin within the output vector space of Fig. 8. It was confirmed that timing adjustments like those in Fig. 8 significantly increase the difference between the target vector and the actual vector, causing current ripple and generating loud noise. This will be explained in more detail with reference to Fig. 10.

[0203] FIG. 10 is a diagram illustrating an example of a control signal when the DPWM method is applied to an inverter having a single shunt. FIG. 11 is a diagram illustrating the current waveform of each phase of the motor in the case of FIG. 10.

[0204] Referring to Fig. 10, specifically, if we check the vector at the top of Fig. 10, a PWM signal is generated to output a small command voltage because the motor does not rotate during the alignment period.

[0205] If you check the reference voltage PWM at the bottom of Fig. 10, you can see that two of the three control signals have a narrow width. Meanwhile, since the operation of Fig. 10 is a DPWM method, one of the three does not operate, so only two PWM signals are generated.

[0206] In this state, in order to secure T1 and T2 as described above, if the modulation / compensation voltage PWM waveform diagram is checked as shown below in Fig. 10, it can be confirmed that the turn-on time of the first switch is adjusted and the turn-on time of the second switch is also adjusted.

[0207] Meanwhile, when such adjustment is made, compensation according to the aforementioned adjustment must be provided in the latter half of the PWM cycle; however, as explained earlier, the DPWM control method does not perform a single switch, so it can be confirmed that all switches are in a turned-off state without compensation in the latter half of the PWM. That is, referring to FIG. 11, it can be confirmed that the phase a current (1110) has a positive value, the phase c current (1130) has a negative value, and the phase b current (1120) remains at 0.

[0208] That is, as shown on the left side of Fig. 10, the actual target vector is an arrow corresponding to 0 degrees. It can be confirmed that the actual output vector is output as a vector with an angle of about 45 degrees.

[0209] Based on the actual simulation results and the measured data, it was confirmed that although the target vector was 0 degrees, a current corresponding to approximately 30 degrees was output. In particular, it was confirmed that in the alignment section, the magnitude of the target voltage itself was small, resulting in a large current error and consequently, motor noise.

[0210] To resolve such problems, the present disclosure utilizes the SVPWM method instead of the DPWM method in the aforementioned forced alignment section. The operation when SVPWM is applied in a single shunt environment is described below.

[0211] FIG. 12 is a diagram illustrating an example of a control signal when a first control method is applied to an inverter having a single shunt. FIG. 13 is a diagram illustrating the current waveform of each phase of the motor in the case of FIG. 12.

[0212] Referring to Fig. 12, as previously explained, since the motor does not rotate during the alignment period, a PWM signal is generated to output a small command voltage.

[0213] When checking the reference voltage PWM of Fig. 12, it can be seen that, unlike Fig. 10, there is a state where all three switch elements are turned on. However, even in that case, due to the insufficient time T1 or T2 for current measurement, the turn-on time of the first switch and the turn-on time of the third switch were adjusted as shown at the bottom of the waveform diagram on the right.

[0214] However, unlike FIG. 10, when checking the corrected PWM in FIG. 12, it can be seen that all switches were in a turned-off state in the latter part of the PWM signal, but in FIG. 12, the V6 vector is output in the latter part of the PWM signal. That is, referring to FIG. 13, it can be seen that the phase a current (1310) has a positive value, and the phase b and c currents (1320, 1330) have negative values.

[0215] Accordingly, when checking the vector space on the left, it can be seen that a vector with an angle of approximately 45 degrees, as shown in Fig. 10, is output at the beginning of the operation, but the actual vector of about 5 degrees is finally formed by a vector pointing toward -45 degrees during the latter part of the PWM. The error between this actual vector (dotted line) and the target vector is significantly reduced compared to the case of Fig. 10.

[0216] In other words, it was confirmed that applying the SVPWM method to the alignment section instead of using the DPWM method reduces the difference in error between the actual vector and the target vector, thereby reducing noise.

[0217] Meanwhile, when comparing the current waveforms of the SVPWM method and the DPWM method for all intervals, it was confirmed that the phase angles of the voltage and current were different in the 120-degree DPWM method at 0 degrees, 120 degrees, and 240 degrees.

[0218] In other sections, the phase angles of voltage and current are similar, but errors occur. On the other hand, it was confirmed that the SVPWM method exhibits almost no error in the phase angles of voltage and current across all sections.

[0219] In this regard, the present disclosure controls the inverter using the SVPWM method during the forced alignment section and the DPWM method during other sections. That is, by operating in the SVPWM method during the initial operation and in the DPWM method after the initial operation, the generation of initial noise can be reduced. Furthermore, since the SVPWM method is used initially, overall energy consumption is not significantly affected.

[0220] FIG. 14 is a flowchart illustrating a method for controlling a dryer according to one embodiment of the present disclosure.

[0221] Referring to FIG. 14, the processor may receive a drive command (1410). For example, this drive command may be a command to start operation for a compressor. For example, it may be a drying start command from a user.

[0222] When a drive command is input in this manner, an operation can be performed to position the rotor within the motor at a preset position. This operation may be a forced alignment operation of the motor.

[0223] First, the dryer checks whether the motor's operating range is a forced alignment range (1420). Whether it is a forced alignment range can be determined by whether it is within a preset time after the motor's driving command input, or whether the reference voltage for the motor is less than or equal to a preset magnitude. Here, the reference voltage may be a voltage capable of creating a vector located at a certain distance from the origin in the vector space of FIG. 8, or a voltage that vectors in a space other than the hatched area in the vector space of FIG. 9.

[0224] If the operating section of the motor is a forced alignment section in which the rotor within the motor is placed at a preset position, the dryer generates a control signal using a first control method (1430). Here, the first control method may be a Space Vector PWM (SVPWM) method, which modulates the three-phase command voltage through a space vector in complex space.

[0225] For example, first, the dryer can check the current flowing through each phase of the motor and generate driving signals for a plurality of switches based on the current magnitude of each phase checked and the first control method.

[0226] If the inverter uses a single shunt, the dryer can measure the voltage value of the resistor at two different points within a cycle to determine the current of the two phases of the motor and calculate the magnitude of the current of the remaining phase based on the two determined currents. To this end, the dryer can generate a driving signal in which the trigger timing of the driving signals for multiple switches is adjusted so that the holding time of the switch state at the point where the voltage value of the resistor is checked is greater than or equal to a preset minimum time.

[0227] Here, the point in time for checking the voltage value described above may be located within a first section in which the first switch is turned on, the second switch is turned off, and the third switch is turned off, and a second section in which the first switch and the second switch are turned on and the third switch is turned off.

[0228] If the motor operation section of the dryer is not a forced alignment section, the first control method generates a control signal using a different second control method (1440). For example, if a certain amount of time has elapsed since the initial operation, or if the reference voltage is greater than a certain magnitude, it is determined that it is not a forced alignment section, and the control method can be switched from the first control method to the second control method. Accordingly, the current flowing through each phase of the motor is checked, and a driving signal for a plurality of switches can be generated based on the current magnitude of each confirmed phase and the second control method. Here, the second control method may be a 120-degree DPWM (Discontinuous PWM) method, which does not perform switching control for a plurality of switches within a preset 120-degree section within one cycle.

[0229] The generated control signal is provided to a plurality of switches (1450). For example, the processor may provide a control signal for each of the six switches to the six switches. Meanwhile, in implementation, the processor may not provide the control information directly to the switches, but may provide the control information to the IPM, and the IPM may control the switches based on the control information.

[0230] As described above, the control method according to the present disclosure utilizes the SVPWM method only during the initial operation of the motor and operates using the DPWM method thereafter, thereby reducing overall energy consumption while also reducing the generation of initial noise.

[0231] Meanwhile, methods according to at least some of the various embodiments of the present disclosure described above may be implemented in the form of an application that can be installed on an existing electronic device.

[0232] In addition, methods according to at least some of the various embodiments of the present disclosure described above may be implemented by software upgrades or hardware upgrades alone for existing electronic devices.

[0233] In addition, methods according to at least some of the various embodiments of the present disclosure described above may also be performed through an embedded server equipped in an electronic device, or through an external server of at least one of the electronic devices.

[0234] Meanwhile, according to one embodiment of the present disclosure, the various embodiments described above may be implemented as software containing instructions stored on a machine-readable storage medium (e.g., a computer). The machine may include an electronic device (e.g., a dryer) according to the disclosed embodiments, which is a device capable of calling instructions stored from the storage medium and operating according to the called instructions. When instructions are executed by a processor, the processor may perform a function corresponding to the instructions directly or using other components under the control of the processor. Instructions may include code generated or executed by a compiler or an interpreter. The machine-readable storage medium may be provided in the form of a non-transitory storage medium. Here, "non-transitory storage medium" simply means that it is a tangible device and does not contain a signal (e.g., electromagnetic waves), and this term does not distinguish between cases where data is stored semi-permanently and cases where it is stored temporarily. For example, A 'non-transient storage medium' may include a buffer in which data is temporarily stored. According to one embodiment, the method according to the various embodiments disclosed herein may be provided by being included in a computer program product. The computer program product may be traded between a seller and a buyer as a product. The computer program product may be distributed in the form of a device-readable storage medium (e.g., compact disc read-only memory (CD-ROM)) or an application store (e.g., Play Store).TM It can be distributed online (e.g., downloaded or uploaded) through ) or directly between two user devices (e.g., terminal devices). For online distribution, at least a portion of the computer program product (e.g., a downloadable app) may be temporarily stored or temporarily created on a device-readable storage medium, such as the memory of a manufacturer's server, an application store's server, or a relay server.

[0235] Various embodiments of the present disclosure may be implemented as software including instructions stored on a machine-readable storage medium (e.g., a computer). The machine may include an electronic device (e.g., a dryer (100)) according to the disclosed embodiments, which is a device capable of calling instructions stored from the storage medium and operating according to the called instructions.

[0236] When the above-described instruction is executed by a processor, the processor may perform the function corresponding to the above-described instruction directly or by using other components under the control of the above-described processor. The instruction may include code generated or executed by a compiler or an interpreter.

[0237] Although preferred embodiments of the present disclosure have been illustrated and described above, the present disclosure is not limited to the specific embodiments described above. It is understood that various modifications can be made by those skilled in the art without departing from the essence of the present disclosure as claimed in the claims, and such modifications should not be understood individually from the technical spirit or perspective of the present disclosure.

Claims

1. Regarding the dryer, A motor that provides rotational force to the compressor; An inverter comprising a single shunt structure composed of a plurality of switches and a single resistor, which supplies driving power to the motor; and One or more processors that control the inverter so that the motor rotates at a preset speed; and The above one or more processors, Check the operating range of the above motor, and If the operating section of the above motor is a forced alignment section in which a rotor within the motor is placed at a preset position, a control signal is generated using a first control method, and If the above motor operation section is not a forced alignment section, the above first control method generates a control signal using a different second control method, and A dryer that provides the above-generated control signal to the plurality of switches.

2. In Paragraph 1, The above inverter is, First to third switches that are commonly connected to one end of a DC power source, with each other end individually connected to one of the plurality of terminals of the motor; and A dryer comprising: fourth to sixth switches, each individually connected to one terminal of the motor and the other terminal connected to the resistor.

3. In Paragraph 2, The above one or more processors, Check the current flowing through each phase of the above motor, and A dryer that generates a driving signal for the plurality of switches based on the current magnitude of each phase identified above and the first control method.

4. In Paragraph 3, The above one or more processors, A dryer that measures the voltage value of the above resistor at two different points within one cycle to determine the current magnitudes of the two phases of the motor, and calculates the current magnitude of the remaining phase based on the two determined current magnitudes.

5. In Paragraph 4, The above one or more processors, A dryer that adjusts the trigger timing of a driving signal for a plurality of switches so that the maintenance time of the switch state at the time of checking the voltage value of the resistor is greater than or equal to a preset minimum time.

6. In Paragraph 5, The above one or more processors, A dryer that adjusts the trigger timing of a driving signal so that each of the first section in which a first switch is turned on, a second switch is turned off, and a third switch is turned off, and the second section in which the first switch and the second switch are turned on and the third switch is turned off, is greater than or equal to the minimum time.

7. In Paragraph 1, The above first control method is, It is a method of modulating the three-phase command voltage through a spatial vector in complex space, and The above second control method is, A dryer that does not perform switching control for the plurality of switches within a preset 120-degree interval within a single cycle.

8. In Paragraph 1, The above first control method is, It is the SVPWM (Space Vector PWM) method, and The above second control method is, A dryer with 120-degree DPWM (Discontinuous PWM).

9. In Paragraph 1, A second motor that rotates the drum; and A dryer further comprising a second inverter that provides driving power to the second motor.

10. In Paragraph 1, The above one or more processors, A dryer that checks for a forced alignment section when the reference voltage for the motor is less than or equal to a preset size after a driving command for the motor is input.

11. In Paragraph 10, The above one or more processors, A dryer that switches the control method from a first control method to a second control method when the operating section of the above motor switches from a forced alignment section to an acceleration section.

12. A control method for a dryer comprising an inverter that provides three-phase driving power to a motor using a single shunt structure composed of a plurality of switches and a single resistor, wherein A step of verifying the operating range of the above motor; If the operating section of the motor is a forced alignment section in which a rotor within the motor is placed at a preset position, a step of generating a control signal using a first control method; If the motor operation section above is not a forced alignment section, the step of generating a control signal using a second control method different from the first control method; and A control method comprising the step of providing the generated control signal to the plurality of switches.

13. In Paragraph 12, The method includes the step of checking the current flowing through each phase of the above motor; and The step of generating a driving signal using the above-mentioned first control method is: A control method for generating a driving signal for the plurality of switches based on the current magnitude of each phase identified above and the first control method.

14. In Paragraph 13, The step of verifying the above current is, The voltage value of the above resistor is measured at two different points within one cycle to determine the current of the two phases of the motor, and the magnitude of the current of the remaining phase is calculated based on the two confirmed currents. The step of generating a driving signal using the above-mentioned first control method is: A control method for adjusting the trigger timing of a driving signal for a plurality of switches such that the time of maintaining the switch state at the time of checking the voltage value of the resistor is greater than or equal to a preset minimum time.

15. In Paragraph 13, The above verification step is, After a driving command for the above motor is input, if the reference voltage for the above motor is below a preset level, it is identified as a forced alignment section, and The step of generating a control signal using the above second control method is: A control method that switches the control method to the second control method when the operating section of the above motor is switched from the forced alignment section to the acceleration section.

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