Household appliance including motor and household appliance control method

Abstract

There is provided a control method of a household appliance (100), the household appliance (100) comprising a motor (120) driven by a driving current, the method comprising the steps of: receiving a stop signal for stopping the motor (120); executing an open brake control for stopping the supply of the drive current to the motor (120) on the basis of receiving the stop signal; estimating an initial motor speed of the motor at the start of the open brake control based on a motor phase current of the motor at the start of the open brake control; determining a start time of short-circuit brake control for applying torque in a direction opposite to a rotation direction of the motor based on the estimated initial motor speed; and executing short-circuit brake control at the determined short-circuit brake control start time.

Description

Technical Field

[0001] Embodiments of the present disclosure relate to a home appliance including a motor, a control method of the home appliance, and a computer-readable recording medium having recorded thereon a program executable by a computer to perform the control method of the home appliance. Background Art

[0002] Home appliances such as refrigerators and air conditioners may include a motor for driving a compressor. For example, home appliances may use a motor such as a brushless three-phase permanent magnet synchronous motor. In order to drive the brushless three-phase permanent magnet synchronous motor, motor phase current and motor speed sensors are required. However, motor speed sensors may not be installed in compressors used in products such as refrigerators and air conditioners. In addition, three current sensors should be used for three-phase current sensing. However, for low cost, small size and small volume, circuits that use one current sensor to sense three-phase current in a DC link have been widely used in home products. Summary of the invention

[0003] According to an embodiment of the present disclosure, a control method for a household appliance (100) is provided, the household appliance (100) comprising a motor (120) driven by a driving current, the control method comprising: receiving a stop signal for stopping the motor (120); based on the received stop signal, performing open-circuit braking control, the open-circuit braking control stopping the supply of driving current to the motor (120); estimating an initial motor speed of the motor when the open-circuit braking control starts based on a motor phase current of the motor when the open-circuit braking control starts; determining a start time point of short-circuit braking control based on the estimated initial motor speed, the short-circuit braking control applying torque in a direction opposite to the rotation direction of the motor (120); and performing short-circuit braking control at the determined start time point of short-circuit braking control.

[0004] In addition, according to an embodiment of the present disclosure, a household appliance (100) is provided, comprising: a motor (120); an inverter (122) configured to output an AC drive current to the motor (120) by generating an AC power supply from a DC power supply; a current sensor (210) configured to measure a motor phase current of the motor (120); a memory (210) storing at least one instruction; and at least one processor (110) configured to execute at least one instruction to: receive a stop signal for stopping the motor (120); based on receiving the stop signal, perform open-circuit braking control, the open-circuit braking control stopping the supply of drive current to the motor (120); based on the motor phase current measured by the current sensor when the open-circuit braking control starts, estimate the initial motor speed of the motor when the open-circuit braking control starts; based on the estimated initial motor speed, determine a start time point of short-circuit braking control, the short-circuit braking control applying torque in a direction opposite to the rotation direction of the motor (120); and perform short-circuit braking control at the determined start time point of short-circuit braking control.

[0005] Furthermore, according to an embodiment of the present disclosure, there is provided a computer-readable recording medium having recorded thereon a program for executing the home appliance control method on a computer. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 is a diagram illustrating the operation of a motor according to an embodiment of the present disclosure.

[0007] Figure 2 is a diagram of a structure of a home appliance according to an embodiment of the present disclosure.

[0008] Figure 3 is a flowchart of a household appliance control method according to an embodiment of the present disclosure.

[0009] Figure 4 is a diagram of the structure of an inverter and a motor according to an embodiment of the present disclosure.

[0010] Figure 5 is a diagram illustrating a process of performing open-circuit brake control according to an embodiment of the present disclosure.

[0011] Figure 6 is a diagram showing a case where a reverse current is generated during open-circuit brake control according to a comparative example.

[0012] Figure 7 is a diagram illustrating a process of performing short-circuit braking control according to an embodiment of the present disclosure.

[0013] Figure 8a is a diagram showing a situation where a braking current is generated according to a comparative example of the present disclosure.

[0014] Figure 8b is a graph showing braking torque according to motor angular velocity.

[0015] Fig. 9 is a diagram of a structure of a home appliance according to an embodiment of the present disclosure.

[0016] Fig.10 is a flowchart illustrating a process of determining a start time point of short-circuit brake control and performing the short-circuit brake control according to an embodiment of the present disclosure.

[0017] Fig.11 is a control block diagram of a drive motor according to an embodiment of the present disclosure.

[0018] Fig.12 is a diagram illustrating a process of estimating a motor speed during open-circuit braking control according to an embodiment of the present disclosure.

[0019] Fig.13 is a flowchart illustrating a process of determining a start time point of short-circuit brake control and performing the short-circuit brake control according to an embodiment of the present disclosure.

[0020] Fig.14 is a diagram illustrating a process of estimating a motor speed according to an embodiment of the present disclosure.

[0021] Fig.15 is a flowchart illustrating a process of determining a start time point of short-circuit brake control and performing the short-circuit brake control according to an embodiment of the present disclosure.

[0022] Fig.16 is a diagram illustrating a process of estimating a start time point of short-circuit braking control according to an embodiment of the present disclosure.

[0023] Fig.17 is a graph of a driving voltage and a direct current (DC) link capacitor voltage for performing open-circuit braking control in a comparative example and an embodiment of the present disclosure.

[0024] Fig.18 is a graph of a driving voltage and a DC link capacitor voltage for performing short-circuit braking control in a comparative example and an embodiment of the present disclosure.

[0025] Fig.19 is a block diagram of a structure of a home appliance according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0026] Throughout the disclosure, the expression "at least one of a, b, or c" means only a, only b, only c, both a and b, both a and c, both b and c, all of a, b, and c, or variations thereof.

[0027] The specification clarifies the scope of the claims, and the principles of the embodiments of the present disclosure are described and explained herein so that a person skilled in the art can practice the embodiments of the present disclosure described in the claims. The embodiments of the present disclosure can be implemented in various forms.

[0028] Throughout the specification, the same reference numerals represent the same components. The specification does not describe all elements of the embodiments of the present disclosure, and a general description of the technical field to which the embodiments of the present disclosure belong or a redundant description of the embodiments of the present disclosure will not be provided herein. The term "module" or "unit" used herein can be implemented as one or a combination of two or more of software, hardware or firmware, and according to an embodiment of the present disclosure, multiple "modules" or "units" can be implemented as one element, or one "module" or "unit" can include multiple elements.

[0029] In the description of the embodiments of the present disclosure, when it is determined that the detailed description of the related known technology may unnecessarily obscure the subject matter of the present disclosure, the detailed description thereof will not be provided herein. In addition, the numbers (e.g., first and second) used in the description of the specification are merely identifiers for distinguishing one component from another component.

[0030] Furthermore, as used herein, unless otherwise described, when one component is referred to as being “connected” to another component, it should be understood that the one component may be directly connected to the other component but may also be connected to the other component with other components in between.

[0031] Hereinafter, working principles of embodiments of the present disclosure and various embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0032] Figure 1 is a diagram illustrating the operation of a motor according to an embodiment of the present disclosure.

[0033] Embodiments of the present disclosure relate to a household appliance 100 including a motor 120. The household appliance 100 may be implemented in the form of, for example, a refrigerator, an air conditioner, a dryer, a dehumidifier, a clothing management device, a shoe management device, etc. The household appliance 100 performs operations such as temperature control and drying by using a compressor 130. The household appliance 100 may include a motor 120 that drives the compressor 130. The motor 120 may supply a driving force for driving the compressor 130. The household appliance 100 may turn on / off the compressor 130 and the motor 120 to perform operations such as temperature control and drying. The household appliance 100 outputs a stop signal to the motor 120 to stop the operation of the compressor 130 and the motor 120.

[0034] The motor 120 stops in response to the stop signal. The inverter 122 controlling the motor 120 may receive a stop drive signal for controlling the motor 120 to stop from the processor 110. The inverter 122 driving the motor 120 may perform a stop operation of stopping the motor 120 in response to the stop drive signal. The method of stopping the motor 120 may include an open-circuit brake control 144 and a short-circuit brake control 146.

[0035] The open-circuit brake control 144 is an operation of stopping supplying a driving current to the motor 120 by turning off all switches of the inverter 122, wherein the inverter 122 supplies the driving current to the motor 120 to drive the motor 120. When the open-circuit brake control 144 is executed, the motor 120 runs freely and stops.

[0036] The short-circuit brake control 146 stops the motor 120 by applying a reverse torque relative to the rotation direction of the motor 120. The short-circuit brake control 146 may turn on some of the multiple switches of the inverter 122 and turn off other switches, forming a closed loop between the motor 120 and the inverter 122, and applying a reverse torque to the motor 120.

[0037] According to an embodiment of the present disclosure, when the motor 120 is stopped, the open-circuit brake control 144 is first performed, and the short-circuit brake control 146 is started at a dynamically determined time point. The time point at which the short-circuit brake control 146 is performed when the open-circuit brake control 144 is performed is dynamically determined by the home appliance 100 based on the speed of the motor 120 when the stop operation starts. The home appliance 100 can estimate the speed (140) of the motor 120, and determine the start time point of the short-circuit brake control 146 based on the estimated speed of the motor 120. The home appliance 100 determines the start time point of the short-circuit brake control 146 so that the short-circuit brake control 146 is started after the speed of the motor 120 decreases to a reference speed value or below.

[0038] When the open circuit braking control 144 is performed, the motor 120 may be reversely rotated due to the pressure difference between the suction and discharge parts of the compressor 130. During the open circuit braking control 144, due to the pressure difference between the suction and discharge parts of the compressor 130, a reverse torque may be applied from the compressor 130 to the motor 120. When the motor 120 is reversely rotated due to the reverse torque, a back electromotive force voltage proportional to the reverse rotation speed of the motor 120 may be generated. When the back electromotive force voltage is applied to the DC link capacitor U DC When charging, the DC link voltage can be increased. When the motor 120 rotates in the reverse direction due to the back electromotive force while the motor 120 is free running due to the open circuit brake control 144, the motor 120 can be used as a generator to increase the DC link capacitor U DCThe DC voltage across the two ends of the inverter 122 flows through the diode of the inverter 122. When the DC link voltage rises, when the DC link voltage exceeds the DC link capacitor U DC When the rated voltage of the DC link capacitor U DC According to an embodiment of the present disclosure, by executing the open-circuit braking control 144 until the speed of the motor 120 reaches the reference speed value and switching to the short-circuit braking control 146, the DC link capacitor U that occurs during the open-circuit braking control 144 can be prevented from being damaged. DC Be penetrated.

[0039] In addition, the short-circuit brake control 146 applies a reverse torque to the rotating motor 120 and stops the motor 120. When the motor 120 rotating at a high speed is stopped using the short-circuit brake control 146, the current flowing to the DC link capacitor U DC The current is blocked, but a large braking current flows to the power switch or diode of the inverter 122. In this case, when the braking current exceeds the rated level of the power switch or diode of the inverter 122, the inverter 122 may be damaged. In addition, when the short-circuit braking control 146 is applied to the inverter 122 using a single DC link current sensor, there is no current sensor in the motor phase current path, so the motor current may not be sensed. According to an embodiment of the present disclosure, in order to prevent excessive breakdown current during the short-circuit braking control 146, the short-circuit braking control 146 is applied after the rotation speed of the motor 120 is reduced by the open-circuit braking control 144. When the timing of entering the short-circuit braking control 146 after the open-circuit braking control 144 is set to be constant, the speed of the motor 120 when entering the short-circuit braking control 146 varies according to the operating speed of the motor 120 before the stop signal is input and the difference between the suction pressure and the discharge pressure. In an embodiment of the present disclosure, the start time point of switching from the open-circuit brake control 144 to the short-circuit brake control 146 is dynamically adjusted so that the short-circuit brake control 146 starts at the same motor speed.

[0040] According to an embodiment of the present disclosure, by performing the open-circuit braking control 144 only before the motor speed reaches the reference speed value, the DC link capacitor U can be prevented from DC Breakdown due to reverse current In addition, according to an embodiment of the present disclosure, by starting the short-circuit brake control 146 when the motor speed reaches the reference speed value, it is possible to prevent the switch or diode of the inverter 122 from being damaged due to excessive braking current.

[0041] Figure 2 is a diagram of a structure of a home appliance according to an embodiment of the present disclosure.

[0042] According to an embodiment of the present disclosure, the home appliance 100 may include a processor 110 , a motor 120 , an inverter 122 , a memory 210 , and a current sensor 220 .

[0043] The processor 110 controls the overall operation of the home appliance 100. The processor 110 may be implemented as one or more processors. The processor 110 may perform a specific operation by executing instructions or commands stored in the memory 210. In addition, the processor 110 controls the operation of components provided in the home appliance 100. The processor 110 may include at least one of a central processing unit (CPU), a graphics processing unit (GPU), or a neural processing unit (NPU), or a combination thereof.

[0044] The motor 120 outputs driving force to a specific home appliance function module of the home appliance 100. The motor 120 may be operated by receiving a driving current from the inverter 122. The motor 120 may be a brushless three-phase permanent magnet synchronous motor.

[0045] The inverter 122 supplies a driving current to the motor 120 to drive the motor 120. The inverter 122 maintains the torque of the motor 120 and controls the speed of the motor 120. The inverter 122 receives DC power, generates an AC driving current through a switching operation, and outputs the driving current to the motor 120. The inverter 122 may include a DC link capacitor U DC The inverter 122 generates a three-phase driving current by controlling the on and off of the multiple switches, and outputs the three-phase driving current to the motor 120 .

[0046] The processor 110 generates a driving signal for driving the inverter 122 and outputs the driving signal. The processor 110 can adjust the driving signal of the inverter 122 to adjust the rotation speed of the motor 120. The processor 110 can adjust the rotation speed of the motor 120 by adjusting the switching frequency of the switch of the inverter 122.

[0047] The memory 210 stores various information, data, instructions, and programs required for the operation of the household appliance 100. The memory 210 may include at least one of a volatile memory or a non-volatile memory or a combination thereof. The memory 210 may include at least one type of storage medium: a flash memory, a hard disk memory, a multimedia card micro memory, a card-type memory (e.g., a secure digital (SD) or extreme digital (XD) memory), a random access memory (RAM), a static RAM (SRAM), a read-only memory (ROM), an electrically erasable programmable ROM (EEPROM), a PROM, a magnetic memory, a magnetic disk, and an optical disk. In addition, the memory 210 may correspond to a network storage device or a cloud server that performs a storage function on the Internet.

[0048] The current sensor 220 measures the current between the inverter 122 and the DC power supply 230. According to an embodiment of the present disclosure, the current sensor 220 may be located between the cathode of the DC power supply 230 and the inverter 122. The current detected by the current sensor 220 in the motor operating state in which the motor 120 supplies a driving force to the compressor 130 corresponds to the motor phase current supplied to the motor 120. The motor phase current has a correlation with the rotation speed of the motor 120. Therefore, the processor 110 may calculate the rotation speed of the motor 120 based on the motor phase current detected by the current sensor 220 when the motor 120 is operating. However, in the motor stop state in which the current is not supplied to the motor 120, the current is not supplied from the DC power supply 230 to the inverter 122. Therefore, in the motor stop state, even the current sensor 220 cannot measure the current flowing through the inverter 122 and the motor 120.

[0049] The DC power supply 230 may correspond to a power module ( Fig.19 1980). The power module receives power from an external power source, converts the power into a rated voltage and current of the home appliance 100, and supplies a driving current to each component.

[0050] When the processor 110 stops the motor 120, the processor 110 generates a stop drive signal for stopping the motor 120, and outputs the stop drive signal to the inverter 122. The stop drive signal includes an open-circuit brake drive signal and a short-circuit brake drive signal. The processor 110 generates a stop drive signal when performing a motor stop operation, and outputs the stop drive signal to the inverter 122.

[0051] The processor 110 estimates the speed of the motor 120 based on the motor phase current. The processor 110 obtains the motor phase current value measured by the current sensor 220 when the stop drive signal is output. The processor 110 estimates the initial motor speed corresponding to the motor speed at the start of the stop operation by using the motor phase current value when the stop drive signal is output. The processor 110 can estimate the initial motor speed according to the motor phase current value by using a function or a lookup table of the correlation between the motor phase current value and the motor speed. The memory 210 can pre-store a function or a lookup table of the correlation between the motor phase current value and the motor speed. The processor 110 can use a function or a lookup table of the correlation between the motor phase current value and the motor speed stored in the memory 210.

[0052] The processor 110 determines the start time point of the short-circuit braking control based on the initial motor speed. The processor 110 determines the start time point of the short-circuit braking control so that the short-circuit braking control starts when the motor speed reaches the reference speed value. When the start time point of the short-circuit braking control is determined, the processor 110 switches from the open-circuit braking control to the short-circuit braking control at the determined start time point of the short-circuit braking control. The processor 110 generates a short-circuit braking drive signal for the short-circuit braking control and outputs the short-circuit braking drive signal to the inverter 122.

[0053] After the short-circuit brake control is performed, after a certain period of time has passed, or after the motor 120 is stopped, the processor 110 terminates the motor stop operation.

[0054] Figure 3 is a flowchart of a household appliance control method according to an embodiment of the present disclosure.

[0055] In a household appliance control method, according to an embodiment of the present disclosure, a household appliance including a motor is controlled. In the present disclosure, the following embodiment of the present disclosure will be mainly described: the household appliance 100 according to the embodiment of the present disclosure performs the household appliance control method. Therefore, the embodiment of the present disclosure described for the household appliance 100 is applicable to the embodiment of the present disclosure for the household appliance control method. On the contrary, the embodiment of the present disclosure described for the household appliance control method is applicable to the embodiment of the present disclosure for the household appliance 100. The household appliance control method according to an embodiment of the present disclosure is not limited to the embodiment of the present disclosure performed by the household appliance 100 set forth in the present disclosure, and can be performed by various types of household appliances.

[0056] In operation S302, the home appliance 100 measures the motor phase current while driving the motor 120. The home appliance 100 measures the current flowing between the DC power source 230 and the inverter 122 by using the current sensor 220.

[0057] Next, in operation S304, the household appliance 100 performs a motor stop operation to stop the motor 120. The household appliance 100 can use the motor 120 to drive a component such as a compressor. For example, the household appliance 100 controls the compressor to perform operations such as temperature control and humidity control. The household appliance 100 can turn on / off the compressor according to a set temperature or a set humidity. The household appliance 100 can stop the operation of the compressor when the compressor is operating to perform temperature control or humidity control. As described above, in order to stop the operation of the compressor, the household appliance 100 can stop the motor 120.

[0058] Next, in operation S306, the household appliance 100 performs open-circuit braking control. The household appliance 100 first performs open-circuit braking control to perform a motor stop operation. The processor 110 generates an open-circuit braking drive signal and outputs the open-circuit braking drive signal to the inverter 122. The inverter 122 disconnects all switches of the inverter 122 by receiving the open-circuit braking drive signal. Since all switches of the inverter 122 are disconnected, the drive current is not output from the inverter 122 to the motor 120. The motor 120 rotates in a free-running state without a drive current.

[0059] Next, in operation S308, the home appliance 100 estimates an initial motor speed based on the motor phase current when the open-circuit braking control starts, which is the motor speed when the open-circuit braking control starts. The home appliance 100 can estimate the initial motor speed according to the motor phase current by using a predefined function or a lookup table.

[0060] Next, in operation S310, the household appliance 100 determines the start time point of the short-circuit braking control based on the initial motor speed. The start time point of the short-circuit braking control is determined as the time point when the motor speed reaches the reference speed value. According to an embodiment of the present disclosure, the household appliance 100 can estimate the motor speed based on the initial motor speed, determine whether the motor speed reaches the reference speed value, and determine the start time point of the short-circuit braking control. In addition, according to an embodiment of the present disclosure, the household appliance 100 can determine the start time point of the short-circuit braking control according to the initial motor speed by using a lookup table.

[0061] Next, in operation S312, the household appliance 100 switches from the open-circuit braking control to the short-circuit braking control at the start time point of the short-circuit braking control. The household appliance 100 generates a short-circuit braking control drive signal for the short-circuit braking control and outputs the short-circuit braking control drive signal to the inverter 122. The inverter 122 receives the short-circuit braking control drive signal, applies a reverse torque to the motor 120, and stops the motor 120.

[0062] Figure 4 is a diagram of the structure of an inverter and a motor according to an embodiment of the present disclosure.

[0063] According to an embodiment of the present disclosure, the inverter 122 may include a plurality of switches (SW1, SW2, SW3, SW4, SW5, and SW6), a plurality of diodes (D1, D2, D3, D4, D5, and D6), and a DC link capacitor U DCA plurality of switches SW1, SW2, SW3, SW4, SW5, SW6 are connected in parallel with diodes D1, D2, D3, D4, D5, and D6, respectively. The first switch SW1 is connected in parallel with the first diode D1, and the second switch SW2 is connected in parallel with the second diode D2. The third switch SW3 is connected in parallel with the third diode D3, and the fourth switch SW4 is connected in parallel with the fourth diode D4. The fifth switch SW5 is connected in parallel with the fifth diode D5, and the sixth switch SW6 is connected in parallel with the sixth diode D6.

[0064] The plurality of switches SW1, SW2, SW3, SW4, SW5, and SW6 perform an on / off operation by receiving a drive signal output from the drive circuit 410. The drive circuit 410 generates a drive signal to be output to the plurality of switches SW1, SW2, SW3, SW4, SW5, and SW6 by receiving a drive signal from the processor 110. The drive circuit 410 generates a drive signal for determining the on / off timing of each of the switches SW1, SW2, SW3, SW4, SW5, and SW6, and outputs the drive signal to each of the switches SW1, SW2, SW3, SW4, SW5, and SW6. For example, the plurality of switches SW1, SW2, SW3, SW4, SW5, and SW6 may correspond to transistors.

[0065] The first phase drive current is generated by the on / off operation of the first switch SW1 and the second switch SW2. The second phase drive current is generated by the on / off operation of the third switch SW3 and the fourth switch SW4. The third phase drive current is generated by the on / off operation of the fifth switch SW5 and the sixth switch SW6. The first phase drive current, the second phase drive current, and the third phase drive current are output to the motor 120. The motor 120 rotates by receiving the first phase drive current, the second phase drive current, and the third phase drive current from the inverter 122.

[0066] Inverter 122 receives a power supply voltage from DC power source 230. DC link capacitor U DC Located across the DC supply voltage.

[0067] The current sensor 220 is between the DC power source 230 and the inverter 122, and measures the current between the DC power source 230 and the inverter 122. The current sensor 220 may be located between the low potential side of the DC power source 230 and the inverter 122.

[0068] Figure 5 is a diagram illustrating a process of performing open-circuit brake control according to an embodiment of the present disclosure.

[0069] When the open-circuit braking control is performed, the switches SW1, SW2, SW3, SW4, SW5, and SW6 of the inverter 122 are all turned off. An open-circuit braking drive signal is generated to turn off all switches of the inverter 122. When the switches SW1, SW2, SW3, SW4, SW5, and SW6 are all turned off, the drive current is not supplied to the motor 120, and the motor 120 enters a free-running state.

[0070] Figure 6 is a diagram showing a case where a reverse current is generated during open-circuit brake control according to a comparative example.

[0071] When the motor 120 is used to drive the compressor, the motor 120 may receive pressure from the compressor. When the motor 120 is stopped using the open circuit brake control, the driving of the compressor is also stopped. When the driving of the compressor is stopped, the motor 120 may rotate in the reverse direction due to the pressure difference between the suction part and the discharge part. When the motor 120 rotates in the reverse direction, in response to the increase in the reverse rotation speed of the motor 120, a back electromotive force voltage proportional to the motor speed is generated. A reverse current may be generated by the back electromotive force voltage. For example, Figure 6 As shown, a reverse current can be generated.

[0072] When the motor 120 rotates in the reverse direction, the motor 120 acts as a generator and generates a back electromotive force voltage. When the back electromotive force is generated, a reverse current flows through the diodes D1, D2, D3, D4, D5, and D6 of the inverter 122. When the reverse current flows through the diodes D1, D2, D3, D4, D5, and D6 of the inverter 122, the DC link capacitor U DC The voltage across the two ends increases. In addition, the DC link capacitor U DC is charged by the reverse current, and therefore, the DC link capacitor U DC The voltage across the DC link voltage increases. When the DC link voltage exceeds the DC link capacitor U DC When the rated voltage of the DC link capacitor U DC Can be damaged.

[0073] According to an embodiment of the present disclosure, before the motor 120 starts to rotate in reverse, the open-circuit brake control is switched to the short-circuit brake control, so that the reverse rotation of the motor 120 can be prevented. In the open-circuit brake control state, after the forward rotation of the motor 120 stops, the motor 120 starts to rotate in reverse. According to an embodiment of the present disclosure, the short-circuit brake control is started when the motor 120 reaches the reference speed value. Therefore, the short-circuit brake control starts before the motor 120 stops. Therefore, the short-circuit brake control starts in the forward rotation state of the motor 120, and the reverse rotation of the motor 120 does not occur.

[0074] Figure 7is a diagram illustrating a process of performing short-circuit braking control according to an embodiment of the present disclosure.

[0075] When short-circuit braking control is performed, some of the switches SW1, SW2, SW3, SW4, SW5, and SW6 of the inverter 122 are turned on, while the other switches are turned off. During the short-circuit braking control, some switches of the inverter 122 form a closed loop with the motor 120. According to an embodiment of the present disclosure, the second switch SW2, the fourth switch SW4, and the sixth switch SW6 of the inverter 122 are turned on, and the first switch SW1, the third switch SW3, and the fifth switch SW5 are turned off. When the short-circuit braking control is performed, the rotation of the motor 120 is stopped by applying a reverse torque to the motor 120.

[0076] Figure 8a is a diagram showing a situation where a braking current is generated according to a comparative example of the present disclosure.

[0077] When short-circuit braking control is performed in a state where the motor speed has a certain magnitude or more, reverse current does not flow to the DC link capacitor U DC , but a large braking current flows to the switches SW1, SW2, SW3, SW4, SW5, and SW6 or the diodes D1, D2, D3, D4, D5, and D6 of the inverter 122. When the braking current exceeds the rated level of the switches SW1, SW2, SW3, SW4, SW5, and SW6 or the diodes D1, D2, D3, D4, D5, and D6 of the inverter 122, the inverter 122 may be damaged. In addition, when the short-circuit braking control is applied to the inverter 122 using a single DC link current sensor, there is no current sensor in the motor phase current path, so the motor current may not be sensed.

[0078] The process of obtaining the motor current during the short-circuit brake control is as follows. The short-circuit brake control forcibly stops the rotation of the motor 120. The driving voltage of the motor 120 is determined by the motor resistance r s , motor current, motor angular velocity ω e , motor inductance and back electromotive force constant. Since the driving voltage becomes 0 during the short-circuit braking control, the driving voltage corresponding to 0 can be expressed as Equation 1 and Equation 2.

[0079] [Equation 1]

[0080]

[0081] [Equation 2]

[0082]

[0083] In this regard, I e drepresents the direct axis (d axis) current, i e q Indicates the quadrature axis (q axis) current, L d represents the d-axis inductance, and L q represents the q-axis inductance. From equations 1 and 2, it can be seen that the d-axis current I during short-circuit braking control is d is defined as Equation 3, and the q-axis current I during short-circuit braking control q is defined as Equation 4.

[0084] [Equation 3]

[0085]

[0086] [Equation 4]

[0087]

[0088] Braking current I s (as the motor current during short-circuit braking control) is defined as Equation 5.

[0089] [Equation 5]

[0090]

[0091] During short-circuit braking control, the motor angular velocity ω e The braking torque due to the braking current generated in this case is defined as Equation 6.

[0092] [Equation 6]

[0093]

[0094] Figure 8b is a graph showing braking torque according to motor angular velocity.

[0095] Referring to Equation 3 and Equation 4, at the motor angular velocity ω e In the case of short-circuit braking control when the motor angular velocity ω is high, the magnitude of the braking current increases rapidly. e When short-circuit braking control is performed at a high value, the braking torque T e On the contrary, it decreases. Figure 8b The curve diagram shows that as the motor angular velocity ω e The increase of the motor angular velocity ω e When the braking torque T e The amplitude increases, but when the motor angular velocity ω e When the braking torque T increases to a certain value or above, e The magnitude is reduced.

[0096] According to an embodiment of the present disclosure, by starting the short-circuit braking control after the open-circuit braking control reduces the motor speed, the short-circuit braking control can not only prevent the generation of the braking current I of the inverter 122 at a rated level or higher, but also s , and can also perform the optimal braking function. Therefore, it is possible to prevent the inverter 122 from being short-circuited during the braking control due to the braking current I s and be damaged.

[0097] Fig. 9 is a diagram of a structure of a home appliance according to an embodiment of the present disclosure.

[0098] According to an embodiment of the present disclosure, the home appliance 100 may include a processor 110, a motor 120, a compressor 130, an inverter 122, a memory 210, a current sensor 220, a first pressure gauge 910, and a second pressure gauge 920. Fig. 9 In the main description and Figure 2 100's of differences in home appliances.

[0099] The motor 120 can provide driving force to the compressor 130. The compressor 130 can be used for temperature control and humidity control. The compressor 130 includes a suction part for sucking air and a discharge part for discharging high-pressure air. The first pressure gauge 910 measures the suction pressure by measuring the air pressure of the suction part. The first pressure gauge 910 outputs the measured suction pressure to the processor 110. The second pressure gauge 920 measures the discharge pressure by measuring the air pressure of the discharge part. The second pressure gauge 920 outputs the measured discharge pressure to the processor 110.

[0100] The processor 110 obtains a suction pressure value and a discharge pressure value. The processor 110 calculates the load torque of the motor 120 by using the suction pressure and the discharge pressure during the open circuit brake control. The processor 110 calculates a reverse pressure obtained by subtracting the suction pressure from the discharge pressure, and calculates the load torque based on the reverse pressure.

[0101] Fig.10 is a flowchart illustrating a process of determining a start time point of short-circuit brake control and performing the short-circuit brake control according to an embodiment of the present disclosure.

[0102] According to an embodiment of the present disclosure, the home appliance 100 repeatedly estimates the motor speed and starts the short-circuit braking control when the motor speed reaches a reference speed value.

[0103] First, in operation S1002, the home appliance 100 measures the suction pressure and the discharge pressure. The home appliance 100 measures the suction pressure by using the first pressure gauge 910, and measures the discharge pressure by using the second pressure gauge 920.

[0104] According to an embodiment of the present disclosure, the home appliance 100 may measure the suction pressure and the discharge pressure after the open-circuit brake control starts. In addition, the home appliance 100 may measure the suction pressure and the discharge pressure while performing the open-circuit brake control.

[0105] In addition, according to an embodiment of the present disclosure, the home appliance 100 can measure the suction pressure and the discharge pressure during the period of driving the compressor 130 and during the period of motor stop operation. The home appliance 100 can monitor the state of the compressor 130 by measuring the suction pressure and the discharge pressure of the compressor 130.

[0106] Next, in operation S1004, the home appliance 100 calculates a load torque based on the suction pressure and the discharge pressure. The load torque is determined based on a value obtained by subtracting the suction pressure from the discharge pressure.

[0107] Next, in operation S1006, the home appliance 100 calculates the sum of the load torque and the friction torque. The friction torque is a torque generated by the friction force of the motor 120. The sum of the load torque and the friction torque corresponds to the reverse torque.

[0108] Next, in operation S1008, the home appliance 100 estimates the motor speed based on the current motor speed and the reverse torque. * , to repeatedly estimate the motor speed ω. At the beginning of the open-circuit braking control, the initial motor speed corresponds to the motor speed ω of the previous cycle e[n-1] . Thereafter, the current cycle motor speed ω estimated in the previous cycle * e[n] Corresponding to the current motor speed, that is, the motor speed of the previous cycle ω e[n-1] The motor speed estimation is repeated until the motor speed reaches the reference speed value.

[0109] Next, in operation S1010, the home appliance 100 determines whether the motor speed is less than or equal to a reference speed value. The reference speed value is determined as a motor speed at which reverse rotation does not occur during open-circuit braking control and a braking current does not exceed a rated current of the inverter 122 during short-circuit braking control.

[0110] When the motor speed is not less than or equal to the reference speed value, the home appliance 100 returns to operation S1002 and re-estimates the motor speed.

[0111] When the motor speed is less than or equal to the reference speed value, the home appliance 100 determines to start the short-circuit braking control in operation S1012.

[0112] In response to determining the start time point of starting the short-circuit brake control, the home appliance 100 performs the short-circuit brake control in operation S312.

[0113] Fig.11 is a control block diagram of a drive motor according to an embodiment of the present disclosure.

[0114] Fig.11 is a model showing the control and motor operation of the motor 120. Fig.11 The model describes the motor operation. Fig.11 The control operation of the motor 120 shown can be performed by the processor 110. The motor model 1130 is a diagram showing the motor 120 based on the input voltage V a（s） Model of the motor speed ω.

[0115] The current sensor 220 measures the motor phase current I during operation of the motor 120. a The proportional-integral-derivative (PID) controller 1110 receives the motor phase current I a and reference current I ref PID controller 1110 uses the difference between V and V generated by PWM control to perform PWM control. a（s） Input to motor model 1130.

[0116] The motor model 1130 has a back electromotive force Back emf generated by the rotation of the motor 120. The back electromotive force Backemf can be calculated by multiplying the rotation speed ω of the motor 120 by the back electromotive force constant K e to calculate.

[0117] The driving voltage V input from the PID controller 1110 a（s） The back electromotive force Back emf is input to the electrical model 1134 of the motor 120. The electrical model 1134 of the motor 120 represents the motor phase current I relative to the input voltage a In the electrical model 1134 of the motor 120, R a represents the motor resistance, and L a Represents the motor inductance. Motor phase current I a and motor resistance R a and motor inductance L a The motor phase current I a The current is detected by the current sensor 220 and fed back to the input end of the PID controller 1110 again.

[0118] Motor phase current I a Drive motor 120. Based on motor phase current I a and motor torque constant K t The driving torque T is generated. In addition, the reverse torque T of the motor 120 l +T f By load torque T l and friction torque Tf The sum of the driving torque T and the reverse torque T l +T f The difference between is input to the motor mechanical model 1136 to calculate the motor speed ω. In the motor mechanical model 1136, B represents the friction coefficient and J represents the moment of inertia. The motor speed ω is inversely proportional to the sum of the integral values ​​of the friction coefficient B and the moment of inertia J.

[0119] When the open-circuit braking control is performed, the current output from the PID controller 1110 is 0. Therefore, since the motor phase current I a is 0, so it can be based on the reverse torque T l +T f The motor speed ω is determined by using the motor mechanical model 1136 . The processor 110 estimates the motor speed ω by using the motor mechanical model 1136 .

[0120] Fig.12 is a diagram illustrating a process of estimating a motor speed during open-circuit braking control according to an embodiment of the present disclosure.

[0121] Fig.12 The process of estimating the motor speed shown corresponds to Fig.10 Operations S1004, S1006 and S1008.

[0122] According to an embodiment of the present disclosure, during the open circuit braking control, the motor phase current I a is 0. Therefore, the motor speed ω is determined by the motor mechanical model 1136. Fig.12 In, ω e[n-1] represents the estimated motor speed in the previous cycle, and ω * e[n] Indicates the estimated motor speed in the current cycle. The estimated motor speed in the current cycle ω * e[n] Again fed back to the reverse torque estimator 1210 .

[0123] The processor 110 repeatedly estimates the motor speed ω during the open-circuit braking control. In the first estimation, the initial motor speed ω * e[n] Input as the motor speed ω of the previous cycle e[n-1] In the second subsequent estimation, the motor speed estimated in the previous cycle is input as the previous cycle motor speed ω e[n-1] .

[0124] The processor 110 obtains the suction pressure P measured by the first pressure gauge 910. 吸入 and the discharge pressure P measured by the second pressure gauge 920 排出 The processor 110 converts the motor speed ω of the previous cycle intoe[n-1] , discharge pressure P 排出 and suction pressure P 吸入 Input to the reverse torque estimator 1210. The reverse torque estimator 1210 receives the motor speed ω of the previous cycle e[n-1] , discharge pressure P 排出 and suction pressure P 吸入 To estimate the reverse torque T l +T f . Load torque T l Based on the discharge pressure P 排出 With suction pressure P 吸入 The friction torque T f Based on the motor speed ω of the previous cycle e[n-1] To determine the reverse torque T l +T f Corresponding to load torque T l and friction torque T f sum.

[0125] The driving torque T is 0 during the open-circuit braking control. Therefore, the current circulating motor speed ω * e[n] By the reverse torque T l +T f The processor 110 determines by using the reverse torque T l +T f and the motor mechanical model 1136 to estimate the current cycle motor speed ω * e[n] In addition, the processor 110 converts the current cycle motor speed ω * e[n] Feedback is given to the reverse torque estimator 1210 to repeatedly estimate the motor speed.

[0126] When the current cycle motor speed ω is calculated * e[n] When the processor 110 determines the current cycle motor speed ω * e[n] Is it less than or equal to the reference speed value? Fig.10 As described in operation S1010, when the current cycle motor speed ω * e[n] When the current cycle motor speed ω is less than or equal to the reference speed value, the processor 110 determines to start the short-circuit braking control in operation S1012. * e[n] When it is greater than the reference speed value, the processor 110 returns to operation S1002 and repeats estimating the motor speed.

[0127] Fig.13is a flowchart illustrating a process of determining a start time point of short-circuit brake control and performing the short-circuit brake control according to an embodiment of the present disclosure.

[0128] Fig.14 is a diagram illustrating a process of estimating a motor speed according to an embodiment of the present disclosure.

[0129] According to an embodiment of the present disclosure, the home appliance 100 repeatedly estimates the motor speed and starts short-circuit braking control when the motor speed reaches a reference speed value. The home appliance 100 may repeatedly estimate the motor speed by using the first lookup table 1410 .

[0130] First, in operation S1302, the home appliance 100 measures the suction pressure and the discharge pressure. The home appliance 100 measures the suction pressure by using the first pressure gauge 910, and measures the discharge pressure by using the second pressure gauge 920.

[0131] According to an embodiment of the present disclosure, the home appliance 100 may measure the suction pressure and the discharge pressure after the open-circuit brake control starts. In addition, the home appliance 100 may measure the suction pressure and the discharge pressure while performing the open-circuit brake control.

[0132] In addition, according to an embodiment of the present disclosure, the home appliance 100 can measure the suction pressure and the discharge pressure during the period of driving the compressor 130 and during the period of motor stop operation. The home appliance 100 can monitor the state of the compressor 130 by measuring the suction pressure and the discharge pressure of the compressor 130.

[0133] Next, in operation S1304, based on the motor speed ω of the previous cycle e[n-1] , discharge pressure P 排出 and suction pressure P 吸入 To estimate the current cycle motor speed ω according to the first lookup table 1410 * e[n] .

[0134] refer to Fig.14 , the household appliance 100 estimates the motor speed ω by using the first lookup table 1410. The first lookup table 1410 includes estimated motor speed values ​​corresponding to the current motor speed, suction pressure, and discharge pressure. The first lookup table 1410 may be pre-stored in the memory 210 of the household appliance 100. The processor 110 may estimate the motor speed ω according to the previous cycle motor speed ω by using the first lookup table 1410 stored in the memory 210. e[n-1] , discharge pressure P 排出 and suction pressure P 吸入 To estimate the current cycle motor speed ω * e[n] .

[0135] Based on the estimated motor speed ω * , to repeatedly estimate the motor speed ω. At the beginning of the open-circuit braking control, the initial motor speed corresponds to the motor speed ω of the previous cycle e[n-1] . Thereafter, the current cycle motor speed ω estimated in the previous cycle * e[n] Corresponding to the current motor speed, that is, the motor speed of the previous cycle ω e[n-1] The motor speed estimation is repeated until the motor speed reaches the reference speed value.

[0136] Next, in operation S1306, the home appliance 100 determines whether the motor speed is less than or equal to a reference speed value. The reference speed value is determined as a motor speed at which reverse rotation does not occur during open-circuit braking control and a braking current does not exceed a rated current of the inverter 122 during short-circuit braking control.

[0137] When the motor speed is not less than or equal to the reference speed value, the home appliance 100 returns to operation S1302 and re-estimates the motor speed.

[0138] When the motor speed is less than or equal to the reference speed value, the home appliance 100 determines to start the short-circuit braking control in operation S1308.

[0139] In response to determining the start time point of starting the short-circuit brake control, the home appliance 100 performs the short-circuit brake control in operation S312.

[0140] Fig.15 is a flowchart illustrating a process of determining a start time point of short-circuit brake control and performing the short-circuit brake control according to an embodiment of the present disclosure.

[0141] Fig.16 is a diagram illustrating a process of estimating a start time point of short-circuit braking control according to an embodiment of the present disclosure.

[0142] According to an embodiment of the present disclosure, the home appliance 100 may be configured based on the initial motor speed ω i , discharge pressure P 排出 and suction pressure P 吸入 Determine the start time point of the short-circuit braking control. The home appliance 100 can be based on the initial motor speed ω i , discharge pressure P 排出 and suction pressure P 吸入 The start time point of the short-circuit braking control is calculated according to the second lookup table 1610 .

[0143] First, in operation S1502, the home appliance 100 measures the suction pressure and the discharge pressure. The home appliance 100 measures the suction pressure by using the first pressure gauge 910 and measures the discharge pressure by using the second pressure gauge 920.

[0144] According to an embodiment of the present disclosure, the home appliance 100 may measure the suction pressure and the discharge pressure after the open-circuit brake control starts. In addition, the home appliance 100 may measure the suction pressure and the discharge pressure while performing the open-circuit brake control.

[0145] In addition, according to an embodiment of the present disclosure, the home appliance 100 can measure the suction pressure and the discharge pressure during the period of driving the compressor 130 and during the period of motor stop operation. The home appliance 100 can monitor the state of the compressor 130 by measuring the suction pressure and the discharge pressure of the compressor 130.

[0146] Next, in operation S1504, based on the initial motor speed ω i , discharge pressure P 排出 and suction pressure P 吸入 The start time point of the short-circuit brake control is determined according to the second lookup table 1610. The start time point of the short-circuit brake control can define the time from the current time point to the start time point of the short-circuit brake control. For example, the start time point of the short-circuit brake control can be defined as after 34:05 seconds.

[0147] refer to Fig.16 , the household appliance 100 estimates the start time point of the short-circuit braking control by using the second lookup table 1610. The second lookup table 1610 includes the start time point values ​​of the short-circuit braking control corresponding to the current motor speed, suction pressure, and discharge pressure. The second lookup table 1610 may be pre-stored in the memory 210 of the household appliance 100. The processor 110 may estimate the start time point of the short-circuit braking control by using the second lookup table 1610 stored in the memory 210 according to the initial motor speed ω i , discharge pressure P 排出 and suction pressure P 吸入 To determine the starting time of short-circuit braking control.

[0148] Next, in operation S1506, when the start time point of the short-circuit brake control is reached, the home appliance 100 performs the short-circuit brake control.

[0149] Fig.17 is a graph of a driving voltage and a DC link capacitor voltage for performing open-circuit braking control in a comparative example and an embodiment of the present disclosure.

[0150] Fig.17The comparative example of shows a case where only the open-circuit braking control is applied. The embodiment of the present disclosure shows a case where the short-circuit braking control is performed at the start time point of the short-circuit braking control determined dynamically after the open-circuit braking control. In the comparative example, it can be seen that the DC link voltage increases during the open-circuit braking control. In contrast, according to the embodiment of the present disclosure, it can be seen that the open-circuit braking control and the short-circuit braking control are performed without an increase in the DC link voltage. In addition, according to the embodiment of the present disclosure, it is determined that the braking current is at a level similar to the operating current.

[0151] Fig.18 is a graph of a driving voltage and a DC link capacitor voltage for performing short-circuit braking control in a comparative example and an embodiment of the present disclosure.

[0152] Fig.18 The comparative example of shows a case where only the short-circuit brake control is applied. The embodiment of the present disclosure shows a case where the short-circuit brake control is performed at a start time point of the short-circuit brake control that is dynamically determined after the open-circuit brake control.

[0153] According to the comparative example, it can be seen that the braking current increases rapidly after the short-circuit braking control starts. In the comparative example, the magnitude of the braking current greatly exceeds the magnitude of the general driving current.

[0154] In contrast, according to the embodiment of the present disclosure, it was determined that the braking current was reduced by 50% or more compared to the comparative example.

[0155] According to an embodiment of the present disclosure, by dynamically adjusting the open-circuit braking control time, even under various conditions where the motor speed is different and the pressure difference between the discharge pressure and the suction pressure is different, short-circuit braking control can be started from the same motor speed. Therefore, according to an embodiment of the present disclosure, the braking current can be significantly reduced, and the increase of the DC link voltage can be prevented. In addition, by adjusting the start time point of the short-circuit braking control, the noise during the stop operation of the motor 120 can be reduced.

[0156] Fig.19 is a block diagram of a structure of a home appliance according to an embodiment of the present disclosure.

[0157] According to an embodiment of the present disclosure, the home appliance 100 may correspond to the home appliance 1900. According to an embodiment of the present disclosure, the home appliance 1900 includes a sensor 1910, an output interface 1920, an input interface 1930, a memory 1940, a communication module 1950, a home appliance operation module 1960, a power module 1980, and a processor 1990. The home appliance 1900 may include Fig.19 Various combinations of components shown, and Fig.19 Not all components shown are required.

[0158] Fig.19 The household appliances 1900 correspond to the reference Figure 2 The household appliance 100 described herein, the memory 1940 corresponds to the reference Figure 2 The memory 210 described above and the processor 1990 correspond to the reference Figure 2 The processor 110 is described.

[0159] The sensor 1910 may include various types of sensors. For example, the sensor 1910 may include various types of sensors, such as a pressure gauge, a current sensor, an image sensor, an infrared sensor, an ultrasonic sensor, a lidar sensor, a human detection sensor, a motion detection sensor, a proximity sensor, and an illumination sensor. A person of ordinary skill in the art can intuitively infer the function of each sensor based on the name of the sensor, and therefore, a detailed description thereof is omitted.

[0160] The output interface 1920 may include a display 1921 and a speaker 1922. The output interface 1920 may output various notifications, messages, and information generated by the processor 1990.

[0161] The input interface 1930 may include a key 1931 and a touch screen 1932. The input interface 1930 receives a user input and transmits the user input to the processor 1990.

[0162] The memory 1940 stores various information, data, instructions, and programs required for the operation of the household appliance 1900. The memory 1940 may include at least one of a volatile memory or a non-volatile memory or a combination thereof. The memory 1940 may include at least one type of storage medium: a flash memory, a hard disk memory, a multimedia card micro memory, a card-type memory (e.g., an SD or XD memory), a random access memory (RAM), a static RAM (SRAM), a read-only memory (ROM), an electrically erasable programmable ROM (EEPROM), a PROM, a magnetic memory, a magnetic disk, and an optical disk. In addition, the household appliance 1900 may operate a network storage device or a cloud server that performs a storage function on the Internet.

[0163] The communication module 1950 may include at least one of a short-range wireless communication module 1952 or a long-range wireless communication module 1954, or a combination thereof. The communication module 1950 may include at least one antenna for wireless communication with another device.

[0164] The short-range wireless communication module 1952 may include a Bluetooth communication module, a Bluetooth low energy (BLE) communication module, a near field communication (NFC) module, a wireless local area network (WLAN) (Wi-Fi) communication module, a Zigbee communication module, an infrared data association (IrDA) communication module, a Wi-Fi direct (WFD) communication module, an ultra-wideband (UWB) communication module, an Ant+ communication module, a microwave (uWave) communication module, etc., but is not limited thereto.

[0165] The long-distance wireless communication module 1954 may include a communication module for performing various types of long-distance communications, and may include a mobile communicator. The mobile communicator transmits or receives wireless signals to or from at least one of a base station, an external terminal, and a server on a mobile communication network. In this case, the wireless signal may include a voice call signal, a video call signal, or various types of data according to the transmission or reception of text / multimedia messages.

[0166] The home appliance operation module 1960 includes an operation module that performs inherent functions of the home appliance 1900. The home appliance operation module 1960 may include a compressor 130, a motor 120, and an inverter 122.

[0167] The power module 1980 is connected to a power source and supplies power to the home appliance 1900 .

[0168] The processor 1990 controls the overall operation of the home appliance 1900. The processor 1990 may control the components of the home appliance 1900 by executing a program stored in the memory 1940.

[0169] According to an embodiment of the present disclosure, the processor 1990 may include a separate NPU that performs operations of an artificial intelligence model. In addition, the processor 1990 may include a CPU, a GPU, and the like.

[0170] The machine-readable storage medium may be provided in the form of a non-transitory storage medium. In this regard, "non-transitory storage medium" simply means that the storage medium is a tangible device and does not include signals (e.g., electromagnetic waves), but the term does not distinguish between the case where data is semi-permanently stored in the storage medium and the case where data is temporarily stored in the storage medium. For example, the "non-transitory storage medium" may include a buffer that temporarily stores data.

[0171] According to an embodiment of the present disclosure, the methods according to various embodiments provided in this document 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 machine-readable storage medium (e.g., a compact disc read-only memory (CD-ROM)), or distributed (e.g., downloaded or uploaded) through an application store, or distributed directly or online 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 application) may be temporarily stored in a machine-readable storage medium (e.g., a memory of a manufacturer's server, an application store's server, or a relay server), or may be temporarily generated.

[0172] According to an embodiment of the present disclosure, a control method for a household appliance 100 is provided, which household appliance 100 includes a motor 120 driven by a driving current, and the control method includes: receiving a stop signal for stopping the motor 120; based on the received stop signal, performing open-circuit braking control, which stops supplying the driving current to the motor 120; based on the motor phase current of the motor when the open-circuit braking control starts, estimating the initial motor speed of the motor when the open-circuit braking control starts; based on the estimated initial motor speed, determining the starting time point of short-circuit braking control, the short-circuit braking control applying torque in a direction opposite to the rotation direction of the motor 120; and performing short-circuit braking control at the determined starting time point of the short-circuit braking control.

[0173] Furthermore, according to an embodiment of the present disclosure, the motor 120 may be a brushless three-phase permanent magnet synchronous motor.

[0174] In addition, according to an embodiment of the present disclosure, the driving current is an AC driving current, the motor 120 receives the driving current from the inverter 122 which is input with a DC power supply, and the method also includes: measuring the motor phase current of the motor 120 when the open-circuit braking control starts by measuring the current input from the DC power supply to the inverter 122.

[0175] In addition, according to an embodiment of the present disclosure, the motor 120 can be configured to drive the compressor 130, and determining the starting time point of the short-circuit braking control may include: repeatedly estimating the motor speed of the motor 120, which is reduced from the initial motor speed; and determining the starting time point of the short-circuit braking control so that the short-circuit braking control is started after the estimated motor speed is reduced to a reference speed value or less.

[0176] In addition, according to an embodiment of the present disclosure, the control method of the household appliance 100 may further include measuring the suction pressure value of the compressor 130 and measuring the discharge pressure value of the compressor 130, wherein repeatedly estimating the motor speed may include: repeatedly estimating the motor speed based on the estimated motor speed, the measured suction pressure value and the measured discharge pressure value.

[0177] In addition, according to an embodiment of the present disclosure, repeatedly estimating the motor speed may also include: calculating the load torque of the motor 120 based on the difference between the suction pressure value and the discharge pressure value; and repeatedly estimating the motor speed based on the sum of the load torque of the motor 120 and the friction torque of the motor 120, the estimated motor speed, the friction coefficient of the motor 120, and the integral value of the moment of inertia of the motor 120.

[0178] In addition, according to an embodiment of the present disclosure, determining the starting time point of short-circuit braking control may also include: based on a first lookup table including estimated motor speed values ​​corresponding to the current motor speed, suction pressure and discharge pressure, repeatedly estimating the motor speed according to the estimated motor speed value, the measured suction pressure value and the measured discharge pressure value; and determining the starting time point of short-circuit braking control so that the short-circuit braking control is started after the estimated motor speed is reduced to a reference speed value or less.

[0179] In addition, according to an embodiment of the present disclosure, the motor 120 may be a motor configured to drive the compressor 130, and the control method of the household appliance 100 may further include measuring the suction pressure value of the compressor 130 and measuring the discharge pressure value of the compressor 130, and determining the starting time point of the short-circuit braking control may include: based on a second lookup table including short-circuit braking switching time values ​​corresponding to the current motor speed, suction pressure and discharge pressure, determining the starting time point of the short-circuit braking control according to the initial motor speed, the measured suction pressure value and the measured discharge pressure value.

[0180] Furthermore, according to an embodiment of the present disclosure, performing the open-circuit braking control may include stopping supplying current to the motor 120 by turning off a switch of the inverter 122 configured to drive the motor 120 .

[0181] Furthermore, according to an embodiment of the present disclosure, performing the short-circuit braking control may include generating a closed loop between circuits of the motor 120 and the inverter 122 by turning on some of the switches of the inverter 122 configured to drive the motor 120 .

[0182] In addition, according to an embodiment of the present disclosure, a household appliance 100 is provided, including: a motor 120; an inverter 122, configured to output an AC drive current to the motor 120 by generating AC power from a DC power supply; a current sensor 210, configured to measure the motor phase current of the motor 120; a memory 210, storing at least one instruction; and at least one processor 110, configured to execute at least one instruction to: receive a stop signal for stopping the motor 120; based on the receipt of the stop signal, perform open-circuit braking control, which stops supplying drive current to the motor 120; based on the motor phase current measured by the current sensor at the start of the open-circuit braking control, estimate the initial motor speed of the motor at the start of the open-circuit braking control; based on the estimated initial motor speed, determine the start time point of the short-circuit braking control, the short-circuit braking control applies torque in a direction opposite to the rotation direction of the motor 120; and perform the short-circuit braking control at the determined start time point of the short-circuit braking control.

[0183] Furthermore, according to an embodiment of the present disclosure, the motor 120 may be a brushless three-phase permanent magnet synchronous motor.

[0184] Furthermore, according to an embodiment of the present disclosure, the current sensor 210 is configured to measure the current input from the DC power source to the inverter 122 to measure the motor phase current.

[0185] In addition, according to an embodiment of the present disclosure, the household appliance 100 may further include a compressor 130 driven by a motor 120, wherein at least one processor 110 may further be configured to execute at least one instruction to: repeatedly estimate the motor speed, which is reduced from an initial motor speed; and determine the starting time point of short-circuit braking control so that the short-circuit braking control starts after the estimated motor speed is reduced to a reference speed value or less.

[0186] In addition, according to an embodiment of the present disclosure, the household appliance 100 may further include a first pressure gauge 910 configured to measure the suction pressure of the compressor 130 and a second pressure gauge 920 configured to measure the discharge pressure of the compressor 130, wherein at least one processor 110 may further be configured to execute at least one instruction to repeatedly estimate the motor speed based on the estimated motor speed, the measured suction pressure value, and the measured discharge pressure value.

[0187] In addition, according to an embodiment of the present disclosure, at least one processor 110 can also be configured to execute at least one instruction to: calculate the load torque of the motor 120 based on the difference between the suction pressure value and the discharge pressure value; and repeatedly estimate the motor speed based on the sum of the load torque of the motor 120 and the friction torque of the motor 120, the estimated motor speed, the friction coefficient of the motor 120, and the integral value of the moment of inertia of the motor 120.

[0188] In addition, according to an embodiment of the present disclosure, the household appliance 100 may further include a compressor 130 driven by a motor 120, a first pressure gauge 910 configured to measure the suction pressure of the compressor 130, and a second pressure gauge 920 configured to measure the discharge pressure of the compressor 130, wherein at least one processor 110 may further be configured to execute at least one instruction to: based on a first lookup table including estimated motor speed values ​​corresponding to the current motor speed, suction pressure and discharge pressure, repeatedly estimate the motor speed according to the estimated motor speed value, the measured suction pressure value and the measured discharge pressure value; and determine the starting time point of the short-circuit braking control so that the short-circuit braking control is started after the estimated motor speed is reduced to a reference speed value or less.

[0189] In addition, according to an embodiment of the present disclosure, the household appliance 100 may further include a compressor 130 driven by a motor 120, a first pressure gauge 910 configured to measure the suction pressure of the compressor 130, and a second pressure gauge 920 configured to measure the discharge pressure of the compressor 130, wherein at least one processor 110 may further be configured to execute at least one instruction to determine the start time point of the short-circuit braking control based on the initial motor speed, the measured suction pressure value, and the measured discharge pressure value based on a second lookup table including short-circuit braking switching time values ​​corresponding to the current motor speed, suction pressure, and discharge pressure.

[0190] In addition, according to an embodiment of the present disclosure, at least one processor 110 may also be configured to execute at least one instruction to perform open-circuit braking control by turning off a switch of an inverter 122 configured to drive the motor 120 and stopping supplying current to the motor 120 .

[0191] In addition, according to an embodiment of the present disclosure, at least one processor 110 can also be configured to execute at least one instruction to perform short-circuit braking control by turning on some of the switches of the inverter 122 configured to drive the motor 120 and generating a closed loop between the circuits of the motor 120 and the inverter 122.

[0192] According to an embodiment of the present disclosure, there is provided a computer-readable recording medium having recorded thereon a program for executing a home appliance control method on a computer.

Claims

1. A control method for a household appliance (100), the household appliance comprising a motor (120) driven by a driving current, the control method comprising: receiving a stop signal for stopping the motor (120); Based on receiving the stop signal, executing open-circuit braking control, the open-circuit braking control stopping supplying the drive current to the motor (120); estimating an initial motor speed of the motor when the open-circuit braking control starts based on a motor phase current of the motor when the open-circuit braking control starts; determining a start time point of a short-circuit braking control that applies a torque in a direction opposite to a rotation direction of the motor (120) based on the estimated initial motor speed; and The short-circuit brake control is executed at the determined start time point of the short-circuit brake control.

2. The control method according to claim 1, wherein: The motor (120) is a brushless three-phase permanent magnet synchronous motor.

3. The control method according to any one of claims 1 and 2, wherein: The driving current is an AC driving current, The motor (120) receives the driving current from an inverter (122) which receives current from a DC power source, and The method further includes measuring a motor phase current of the motor (120) when the open-circuit braking control starts by measuring the current input from the DC power supply to the inverter (122).

4. The control method according to any one of claims 1 to 3, wherein: The motor (120) is configured to drive a compressor (130), and Determining the starting time point of the short-circuit braking control includes: repeatedly estimating a motor speed of the motor (120), the motor speed decreasing from the initial motor speed, and A start time point of the short-circuit brake control is determined such that the short-circuit brake control is started after a time point at which the estimated motor speed decreases to a reference speed value or less.

5. The control method according to claim 4, further comprising: measuring a suction pressure value of the compressor (130); as well as measuring the discharge pressure value of the compressor (130), Wherein, repeatedly estimating the motor speed includes: repeatedly estimating the motor speed based on the estimated motor speed, the measured suction pressure value, and the measured discharge pressure value.

6. The control method according to claim 5, wherein: Repeatingly estimating the motor speed further comprises: calculating the load torque of the motor (120) based on the difference between the measured suction pressure value and the measured discharge pressure value, and The motor speed is repeatedly estimated based on the calculated sum of the load torque of the motor (120) and the friction torque of the motor (120), the estimated motor speed, the friction coefficient of the motor (120), and the integrated value of the inertia moment of the motor (120).

7. The control method according to any one of claims 1 to 6, wherein: Determining the starting time point of the short-circuit braking control includes: repeatedly estimating the motor speed based on the estimated motor speed value, the measured suction pressure value, and the measured discharge pressure value based on a lookup table including estimated motor speed values ​​corresponding to current motor speed, suction pressure, and discharge pressure, and A start time point of the short-circuit brake control is determined such that the short-circuit brake control is started after a time point at which the estimated motor speed decreases to the reference speed value or less.

8. The control method according to any one of claims 1 to 6, wherein: The motor (120) is configured to drive a compressor (130), and The control method further comprises: measuring the suction pressure value of the compressor (130), and measuring the discharge pressure value of the compressor (130), and Determining the starting time point of the short-circuit braking control includes: based on a lookup table including short-circuit braking switching time values ​​corresponding to the current motor speed, suction pressure and discharge pressure, determining the starting time point of the short-circuit braking control according to the initial motor speed, the measured suction pressure value and the measured discharge pressure value.

9. The control method according to any one of claims 1 to 8, wherein: Executing the open circuit braking control includes: By turning off a switch of an inverter (122) configured to drive the motor (120), supply of the driving current to the motor (120) is stopped.

10. The control method according to any one of claims 1 to 9, wherein: Executing the short-circuit braking control includes: By turning on some switches of an inverter (122) configured to drive the motor, a closed loop is generated between the motor (120) and the circuit of the inverter (122).

11. A household appliance (100), comprising: Motor (120); An inverter (122) configured to output an AC driving current to the motor (120) by generating AC power from a DC power source; A current sensor (210) configured to measure a motor phase current of the motor (120); A memory (210) storing at least one instruction; as well as At least one processor (110) configured to execute the at least one instruction to: receiving a stop signal for stopping the motor (120), Based on receiving the stop signal, an open-circuit brake control is performed, wherein the open-circuit brake control stops supplying the drive current to the motor (120), estimating an initial motor speed of the motor when the open-circuit brake control starts based on the motor phase current measured by the current sensor when the open-circuit brake control starts, determining a start time point of a short-circuit braking control based on the estimated initial motor speed, the short-circuit braking control applying a torque in a direction opposite to the rotation direction of the motor (120); and The short-circuit brake control is executed at the determined start time point of the short-circuit brake control.

12. The household appliance (100) according to claim 11, wherein: The motor (120) is a brushless three-phase permanent magnet synchronous motor.

13. The household appliance (100) according to any one of claims 11 and 12, wherein: The current sensor (210) is configured to measure the current input from the DC power source to the inverter (122) to measure the motor phase current.

14. The household appliance (100) according to any one of claims 11 to 13, further comprising: A compressor (130), driven by the motor (120), The at least one processor (110) is further configured to execute the at least one instruction to: repeatedly estimating a motor speed of the motor (120), the motor speed decreasing from the initial motor speed, and A start time point of the short-circuit brake control is determined such that the short-circuit brake control is started after a time point at which the estimated motor speed decreases to a reference speed value or less. 15 . A computer-readable recording medium having recorded thereon a program that can be executed by a computer to execute the control method according to claim 1 .

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