Motor three-phase current construction method, refrigeration equipment and household electrical appliance product

Abstract

The invention discloses a motor three-phase current construction method, refrigeration equipment and a household appliance. A sampling period comprises two pulse width modulation periods, and a first sampling window and a second sampling window of the first pulse width modulation period are obtained; when the width of the sampling window is smaller than the preset shortest window width, performing phase shift processing on the first pulse width modulation period to enable the widths of all the sampling windows to be larger than or equal to the shortest window width to meet the sampling requirement, and performing phase shift processing opposite to the first pulse width modulation period on the second pulse width modulation period to enable the width of all the sampling windows to be larger than or equal to the preset shortest window width to meet the sampling requirement; the waveforms in the two pulse width modulation periods are kept symmetrical as far as possible; the first current and the second current of the motor are acquired to construct the three-phase current of the motor under the condition that the sampling window meets the sampling requirement and the waveform in the sampling period is kept symmetrical as far as possible, so that the accuracy of current acquisition is ensured, the accurate construction of the three-phase current is ensured, and the reliability of the motor is improved. And meanwhile, the influence of phase shifting on motor control performance is reduced.

Description

Technical Field

[0001] This invention relates to the field of motor technology, and in particular to a method for constructing three-phase current in a motor, a refrigeration device, and a household appliance. Background Technology

[0002] As an electromagnetic device, the electric motor is mainly used to convert electrical energy into mechanical energy to drive various electrical appliances or machines. For example, electric motors are used in household appliances such as refrigerators and air conditioners to provide power for their compressors. A crucial step in motor control is the detection of the motor's three-phase current. Considering factors such as cost and board layout flexibility, a single-resistor sampling method is typically used for current detection.

[0003] The single-resistor sampling method requires sampling the current twice at different times within a carrier frequency cycle to construct the three-phase current. This method has the risk of not providing a sufficient sampling time window for current sampling, leading to inaccurate current sampling. Phase shifting of the PWM waveform is often used to address this technical deficiency, but this method alters the waveform and affects motor control performance. Summary of the Invention

[0004] The purpose of this invention is to provide a method for constructing three-phase current of a motor, a refrigeration device, and a home appliance. This method can set two pulse width modulation cycles within one sampling period, and perform phase shifting processing on the waveforms within the two pulse width modulation cycles to ensure that the sampling window meets the sampling requirements, maintain the symmetry of the waveforms within the sampling period, guarantee the accuracy of the constructed three-phase current, and reduce the impact of phase shifting on motor control performance.

[0005] To achieve the above objectives, embodiments of the present invention provide a method for constructing three-phase current in a motor, comprising:

[0006] Obtain the sampling window of the first pulse width modulation period within the sampling period; wherein, the sampling period includes the first pulse width modulation period and the second pulse width modulation period, and the sampling window includes a first sampling window and a second sampling window;

[0007] When the width of a sampling window is less than the preset minimum window width, the first pulse width modulation period is phase-shifted, and the second pulse width modulation period is phase-shifted in the opposite direction to the first pulse width modulation period, so that the widths of the first sampling window and the second sampling window are both greater than or equal to the minimum window width.

[0008] The first and second currents of the motor are collected in a sampling window whose width is greater than or equal to the width of the shortest window.

[0009] The three-phase current of the motor is constructed based on the first current and the second current.

[0010] As an improvement to the above scheme, when the width of a sampling window is less than the preset minimum window width, the first pulse width modulation period is phase-shifted, and the second pulse width modulation period is phase-shifted in the opposite direction to the first pulse width modulation period, so that the widths of both the first and second sampling windows are greater than or equal to the minimum window width, including:

[0011] When the sum of the widths of the first sampling window and the second sampling window is greater than or equal to twice the preset shortest window width, and the width of the second sampling window is less than the shortest window width, the middle phase in the first pulse width modulation period is shifted to the left, and the middle phase in the second pulse width modulation period is shifted to the right, so that the widths of both the first and second sampling windows are greater than or equal to the shortest window width; wherein the middle phases in the first and second pulse width modulation periods move to the same degree, the first sampling window is determined based on the maximum and middle phases in the first pulse width modulation period, and the second sampling window is determined based on the middle and minimum phases in the first pulse width modulation period.

[0012] As an improvement to the above scheme, when the width of a sampling window is less than the preset minimum window width, the first pulse width modulation period is phase-shifted, and the second pulse width modulation period is phase-shifted in the opposite direction to the first pulse width modulation period, so that the widths of both the first and second sampling windows are greater than or equal to the minimum window width, including:

[0013] When the sum of the widths of the first sampling window and the second sampling window is greater than or equal to twice the preset minimum window width, and the width of the first sampling window is less than the minimum window width, the middle phase in the first pulse width modulation period is controlled to shift to the right, and the middle phase in the second pulse width modulation period is controlled to shift to the left, so that the widths of both the first and second sampling windows are greater than or equal to the minimum window width; wherein, the middle phases in the first and second pulse width modulation periods move to the same degree, the first sampling window is determined based on the maximum and middle phases in the first pulse width modulation period, and the second sampling window is determined based on the middle and minimum phases in the first pulse width modulation period.

[0014] As an improvement to the above scheme, when the width of a sampling window is less than the preset minimum window width, the first pulse width modulation period is phase-shifted, and the second pulse width modulation period is phase-shifted in the opposite direction to the first pulse width modulation period, so that the widths of both the first and second sampling windows are greater than or equal to the minimum window width, including:

[0015] When the sum of the widths of the first sampling window and the second sampling window is less than twice the preset minimum window width, and the width of the first sampling window is greater than or equal to the minimum window width, the minimum phase in the first pulse width modulation period is shifted to the right, and the minimum phase in the second pulse width modulation period is shifted to the left, so that the widths of both the first and second sampling windows are greater than or equal to the minimum window width; wherein the minimum phase shifts to the same extent in the first and second pulse width modulation periods, the first sampling window is determined based on the maximum and intermediate phases in the first pulse width modulation period, and the second sampling window is determined based on the intermediate and minimum phases in the first pulse width modulation period.

[0016] As an improvement to the above scheme, when the width of a sampling window is less than the preset minimum window width, the first pulse width modulation period is phase-shifted, and the second pulse width modulation period is phase-shifted in the opposite direction to the first pulse width modulation period, so that the widths of both the first and second sampling windows are greater than or equal to the minimum window width, including:

[0017] When the sum of the widths of the first sampling window and the second sampling window is less than twice the preset minimum window width, and the width of the first sampling window is less than the minimum window width, the intermediate phase and the minimum phase within the first pulse width modulation period are shifted to the right, and the intermediate phase and the minimum phase within the second pulse width modulation period are shifted to the left, so that the widths of both the first sampling window and the second sampling window are greater than or equal to the minimum window width; wherein, the intermediate phase within the first pulse width modulation period and the second pulse width modulation period shift to the same degree, the minimum phase within the first pulse width modulation period and the second pulse width modulation period shift to the same degree, the first sampling window is determined based on the maximum phase and the intermediate phase within the first pulse width modulation period, and the second sampling window is determined based on the intermediate phase and the minimum phase within the first pulse width modulation period.

[0018] As an improvement to the above scheme, the step of obtaining the sampling window of the first pulse width modulation period within the sampling period includes:

[0019] The duty cycle information of the PWM waveform in the first and second pulse width modulation periods within the new sampling period is calculated based on the historical current sampling results, in order to determine the sampling window of the first pulse width modulation period within the new sampling period; wherein, the sampling window includes a first sampling window and a second sampling window;

[0020] When the width of a sampling window is less than the preset minimum window width, the first pulse width modulation period is phase-shifted, and the second pulse width modulation period is phase-shifted in the opposite direction to the first pulse width modulation period, so that the widths of both the first and second sampling windows are greater than or equal to the minimum window width, including:

[0021] When the width of the sampling window is less than the preset minimum time window width, the PWM waveform duty cycle information of the first pulse width modulation cycle in the new sampling cycle is updated with the goal that the widths of both the first and second sampling windows are greater than the minimum time window width. Based on the principle that the PWM waveforms of the first and second pulse width modulation cycles in the same sampling cycle are axially symmetrical, the PWM waveform duty cycle information of the second pulse width modulation cycle is updated according to the adjusted PWM waveform duty cycle information of the first pulse width modulation cycle, so as to control the current parameters of the motor in the first and second pulse width modulation cycles in the new sampling cycle.

[0022] The step of acquiring the first and second currents of the motor within a sampling window with a width greater than or equal to the width of the shortest window includes:

[0023] The first acquisition time and the second acquisition time are determined based on the first target duty cycle information; wherein, the first target duty cycle information is the PWM waveform duty cycle information of the first pulse width modulation period within the new round of sampling period, and the sampling window of the first target duty cycle information is greater than or equal to the minimum time window width;

[0024] The first current and the second current of the motor are collected at the first acquisition time and the second acquisition time, respectively.

[0025] As an improvement to the above solution, it also includes:

[0026] If there is an update operation in the PWM waveform of the first pulse width modulation cycle in the new sampling cycle, the specified flag bit is set to the first specified value; if there is no update operation in the PWM waveform of the first pulse width modulation cycle in the new sampling cycle, the specified flag bit is set to the second specified value.

[0027] At the end of the previous sampling cycle, the first target duty cycle information is updated to the designated duty cycle register to control the current parameters of the motor in the new sampling cycle.

[0028] At the end of the first pulse width modulation cycle of a new sampling cycle, if the specified flag bit is the first specified value, the second target duty cycle information is updated in the duty cycle register to control the current parameters of the motor in the second pulse width modulation cycle of the new sampling cycle; wherein, the second target duty cycle information is the updated PWM waveform duty cycle information in the second pulse width modulation cycle of the new sampling cycle.

[0029] As an improvement to the above scheme, the shortest window width is calculated based on the acquired ringing time, dead time, and hardware sampling time.

[0030] To achieve the above objectives, embodiments of the present invention provide a refrigeration device, comprising:

[0031] The refrigerant circuit circulates refrigerant sequentially through a compressor, condenser, pressure reducer, and evaporator;

[0032] The compressor has a motor and a compression mechanism inside its cavity. The motor is used to drive the compression mechanism to compress the refrigerant and provide power for the refrigeration cycle.

[0033] The controller is used to perform the method as described in any of the above embodiments, and is also used to control the operating parameters of the compressor based on the three-phase current of the motor.

[0034] To achieve the above objectives, embodiments of the present invention provide a home appliance product, comprising:

[0035] The appliance body includes a motor and a driven device, wherein the motor is used to drive the driven device to operate.

[0036] The controller is configured to perform the method described in any of the above embodiments, and is also configured to control the operating parameters of the motor according to the three-phase current of the motor to drive the driven device to operate.

[0037] Compared to existing technologies, the method for constructing three-phase current of a motor, the refrigeration equipment, and the home appliance products disclosed in this invention have a sampling period that is pre-set to include a first pulse width modulation period and a second pulse width modulation period. First, a first sampling window and a second sampling window of the first pulse width modulation period are acquired. When the width of a sampling window is less than the preset minimum window width, on the one hand, the first pulse width modulation period is phase-shifted so that the width of all sampling windows is greater than or equal to the minimum window width to meet the sampling requirements. On the other hand, the second pulse width modulation period is phase-shifted in the opposite direction to the first pulse width modulation period so that the waveforms within the two pulse width modulation periods are kept as symmetrical as possible. Then, while ensuring that the sampling windows meet the sampling requirements and the waveforms within the sampling period are kept as symmetrical as possible, the first current and the second current of the motor are acquired to construct the three-phase current of the motor, ensuring the accuracy of current acquisition and thus ensuring the accurate construction of the three-phase current, while reducing the impact of phase shifting on the motor control performance. Attached Figure Description

[0038] Figure 1 This is a perspective view of the refrigerator provided in an embodiment of the present invention;

[0039] Figure 2 This is a schematic diagram of the refrigeration system of the refrigerator provided in an embodiment of the present invention;

[0040] Figure 3 This is a schematic diagram of the structure of the air conditioner provided in an embodiment of the present invention;

[0041] Figure 4 This is a schematic diagram of the refrigeration system of the air conditioner provided in an embodiment of the present invention;

[0042] Figure 5 This is a schematic diagram of the working principle of the compressor provided in an embodiment of the present invention;

[0043] Figure 6 This is a first working flowchart of the controller provided in an embodiment of the present invention;

[0044] Figure 7 It is the PWM waveform signal of the first pulse width modulation period provided in the embodiments of the present invention;

[0045] Figure 8 This is a schematic diagram of a phase-shifting process provided in an embodiment of the present invention;

[0046] Figure 9 This is a second workflow diagram of the controller provided in an embodiment of the present invention;

[0047] Figure 10 This is a third workflow diagram of the controller provided in an embodiment of the present invention;

[0048] Figure 11 This is the fourth workflow diagram of the controller provided in this embodiment of the invention;

[0049] Figure 12 This is the fifth workflow diagram of the controller provided in this embodiment of the invention;

[0050] Figure 13 This is a flowchart of motor control provided in an embodiment of the present invention;

[0051] Figure 14 This is a flowchart illustrating a method for constructing three-phase current in a motor, as provided in an embodiment of the present invention.

[0052] Among them, 100 is the cabinet, 200 is the door, 300 is the indoor unit, 400 is the outdoor unit, 1 is the compressor, 2 is the condenser, 3 is the anti-condensation pipe, 4 is the dryer filter, 5 is the pressure reducer, 6 is the evaporator, 7 is the gas-liquid separator, 8 is the motor, 9 is the crank, 10 is the connecting rod, 11 is the slider, 12 is the cylinder, 13 is the piston, 14 is the intake valve, and 15 is the exhaust valve. Detailed Implementation

[0053] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0054] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0055] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0056] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0057] This invention provides a refrigeration device, including a refrigerant circuit in which refrigerant circulates sequentially through a compressor, a condenser, a pressure reducer, and an evaporator. The compressor has a motor and a compression mechanism inside its cavity. The motor drives the compression mechanism to compress the refrigerant, providing power for the refrigeration cycle. A controller is used to generate the three-phase current of the motor and control the operating parameters of the compressor based on the three-phase current of the motor.

[0058] Specifically, the refrigeration equipment may be a refrigerator, an air conditioner, a wine cabinet, etc., and is not limited thereto.

[0059] The following section will take refrigerators and air conditioners as examples to provide a detailed introduction to the refrigerant circuit of refrigeration equipment.

[0060] See Figure 1 , Figure 1 This is a perspective view of a refrigerator according to an embodiment of the present invention. The refrigerator of this embodiment has an approximately cuboid shape and includes a cabinet 100 defining a storage space and multiple doors 200 disposed at the opening of the cabinet 100. Each door 200 includes a door shell located outside the cabinet 100, a door inner liner located inside the cabinet 100, an upper end cover, a lower end cover, and an insulation layer located between the door shell, door inner liner, upper end cover, and lower end cover; typically, the insulation layer is filled with foam material. The cabinet 100 has chambers, including component storage chambers for placing refrigerator components, such as a compressor, and storage space for storing food, etc. The refrigerator in this embodiment of the present invention includes a refrigeration system, see [link to relevant documentation]. Figure 3 The diagram shows the structure of the refrigeration system, which is located in the component storage cavity and provides power for the refrigerator's refrigeration cycle. It includes a compressor, evaporator, pressure reducer, and condenser. The storage space can be divided into multiple compartments, which can be configured as refrigerator compartments, freezer compartments, etc., depending on their purpose. Each compartment corresponds to one or more doors, for example, in... Figure 1 The upper compartment has double doors. These doors can be pivotally mounted at the opening of the cabinet or can open like drawers for drawer-style storage.

[0061] A refrigeration system includes at least a compressor, a condenser, a pressure reducer, and an evaporator, forming a refrigerant circuit. For example, see [link to relevant documentation]. Figure 2 , Figure 2 This is a schematic diagram of the refrigeration system in a refrigerator provided in an embodiment of the present invention. The refrigeration system includes a compressor 1, a condenser 2, an anti-condensation pipe 3, a dryer filter 4, a pressure reducer 5, an evaporator 6, and a gas-liquid separator 7. The working process of the refrigeration system includes a compression process, a condensation process, a throttling process, and an evaporation process.

[0062] Among them, combined Figure 2 The compression process is as follows: When the refrigerator power cord is plugged in and the thermostat contacts are closed, compressor 1 starts working. Low-temperature, low-pressure refrigerant is drawn into compressor 1 and compressed into high-temperature, high-pressure superheated gas in the cylinder of compressor 1 before being discharged into condenser 2. The condensation process is as follows: The high-temperature, high-pressure refrigerant gas dissipates heat through condenser 2, and its temperature continuously decreases, gradually cooling into room-temperature, high-pressure saturated vapor, and further cooling into saturated liquid, at which point the temperature no longer decreases. This temperature is called the condensation temperature, and the pressure of the refrigerant remains almost constant throughout the entire condensation process. The throttling process is as follows: After passing through... After condensation, the saturated liquid refrigerant flows into the pressure reducer 5 (e.g., a capillary tube) after being filtered to remove moisture and impurities by the dryer filter 4. The pressure is reduced by the pressure reducer, turning the refrigerant into a room-temperature, low-pressure wet vapor. The evaporation process is as follows: the room-temperature, low-pressure wet vapor begins to absorb heat and vaporize in the evaporator 6, which not only lowers the temperature of the evaporator and its surroundings but also turns the refrigerant into a low-temperature, low-pressure gas. The refrigerant exiting the evaporator 6 passes through the gas-liquid separator 7 and returns to the compressor 1, repeating the above process to transfer heat from inside the refrigerator to the outside air, thus achieving the purpose of refrigeration.

[0063] See Figure 3 The air conditioner described in this embodiment of the invention includes an indoor unit 300 and an outdoor unit 400. The indoor unit 300 is used to regulate the temperature and humidity of the indoor air. The outdoor unit 400 is connected to the indoor unit 300 through a connecting pipe. The outdoor unit 400 is installed outdoors, and the indoor unit 300 is installed indoors.

[0064] The air conditioner is equipped with a refrigerant circuit. Specifically, the refrigerant circuit circulates refrigerant sequentially through a compressor, condenser, depressurizer, and evaporator. One of the condenser and the evaporator is an outdoor heat exchanger, and the other is an indoor heat exchanger.

[0065] The heat exchange principle in the refrigerant circuit of an air conditioner is as follows:

[0066] See Figure 4The diagram shows the structure of the refrigeration system of an air conditioner. The refrigeration system includes a compressor 1, a condenser 2, a pressure reducer 5, and an evaporator 6, forming a refrigerant circuit. The refrigerant cycle involves a series of processes, including compression, condensation, expansion, and evaporation, supplying refrigerant to regulated and heat-exchanged air. The compressor 1 compresses the refrigerant gas at high temperature and high pressure and discharges the compressed refrigerant gas. The discharged refrigerant gas flows into the condenser 2, where it condenses the compressed refrigerant into a liquid phase, releasing heat to the surrounding environment through the condensation process. The pressure reducer 5 expands the high-temperature, high-pressure liquid refrigerant condensed in the condenser 2 into a low-pressure liquid refrigerant. The evaporator 6 evaporates the refrigerant that expanded in the pressure reducer and returns the low-temperature, low-pressure refrigerant gas to the compressor 1. The evaporator 6 achieves the cooling effect by utilizing the latent heat of refrigerant evaporation to exchange heat with the material being cooled.

[0067] It is worth noting that the air conditioner described in the embodiments of the present invention is not limited to the specific split-type air conditioner mentioned above, but can also be an integrated air conditioner, such as a window air conditioner. The specific type of air conditioner is not limited here.

[0068] Specifically, the compressor's internal cavity includes the motor and compression mechanism. The compressor mainly consists of a housing, motor (including rotor and stator), crankshaft, connecting rod, piston, cylinder, and piping. The motor, connecting rod, and cylinder are supported on the housing by several springs. See also... Figure 5 , Figure 5 This is a schematic diagram of the working principle of a compressor provided in an embodiment of the present invention. The motor 8 rotates, and the crank 9 drives the connecting rod 10 to control the slider 11 to slide, thereby acting on the piston 13 in the cylinder 12, controlling the intake valve 14 and exhaust valve 15 of the cylinder 12 to perform intake and exhaust.

[0069] Specifically, the refrigeration equipment further includes a controller. In this embodiment of the invention, the controller is electrically connected to each of the controllable devices. The controller is configured to: acquire a sampling window of a first pulse width modulation period within a sampling period; wherein the sampling period includes the first pulse width modulation period and a second pulse width modulation period, and the sampling window includes a first sampling window and a second sampling window; when the width of a sampling window is less than a preset minimum window width, perform phase shifting processing on the first pulse width modulation period and perform phase shifting processing on the second pulse width modulation period in the opposite direction to the first pulse width modulation period, so that the widths of the first sampling window and the second sampling window are both greater than or equal to the minimum window width; acquire the first current and the second current of the motor within the sampling window whose width is greater than or equal to the minimum window width; construct the three-phase current of the motor based on the first current and the second current; and control the operating parameters of the compressor based on the three-phase current of the motor.

[0070] For example, see Figure 6 , Figure 6 This is a first flowchart of the controller provided in an embodiment of the present invention, wherein the controller is used to execute steps S11 to S14:

[0071] S11. Obtain the first sampling window and the second sampling window of the first pulse width modulation period within the sampling period, and then proceed to step S12.

[0072] Specifically, see Figure 7 , Figure 7 This invention provides a PWM waveform signal for the first pulse width modulation cycle, including the duty cycle information of the three phases U, V, and W. The sampling window is determined based on the phase flip point: the first sampling window is between the rising edge of phase U and the rising edge of phase V, and the second sampling window is between the rising edge of phase V and the rising edge of phase W. Within one sampling cycle, corresponding to two PWM carrier frequency cycles (i.e., two pulse width modulation cycles), one sampling operation generates two PWM waves. Analog-to-digital sampling is generally set within the first carrier frequency cycle (by phase shifting to obtain the minimum sampling time), and the second carrier frequency cycle uses symmetrical complementary phase shifting to generate the PWM wave. PWM stands for Pulse Width Modulation.

[0073] S12. Determine whether the width of the first sampling window or the width of the second sampling window is less than the preset minimum window width. If yes, proceed to step S13; otherwise, proceed to step S14.

[0074] Specifically, the shortest window width is the shortest time required for current sampling. It is determined whether there is a sampling window with a width less than the shortest window width. If so, it means that the sampling window width is too small to meet the current sampling requirements and cannot accurately collect the current. If the widths of the two sampling windows are both greater than or equal to the shortest window width, then the current sampling requirements are met, and the current can be collected directly using the sampling window.

[0075] S13. Perform phase shifting processing on the first pulse width modulation period and perform phase shifting processing on the second pulse width modulation period in the opposite direction to the first pulse width modulation period, so that the widths of the first sampling window and the second sampling window are both greater than or equal to the shortest window width, and proceed to step S14.

[0076] Specifically, when the sampling window width is too small, the three-phase duty cycle of the first pulse width modulation period needs to be phase-shifted accordingly to ensure that the widths of both the first and second sampling windows are greater than or equal to the shortest window width, thus meeting the current sampling requirements. For example... Figure 8 As shown, Figure 8This is a schematic diagram of a phase-shifting process provided in this embodiment. Assuming that the duty cycle of phase U is close to that of phase V, then Ton(U) - Ton(V) < Tp, where Ton refers to the rising edge time and Tp refers to the shortest window width. The first sampling window does not have sufficient current sampling time to complete two current samples within one cycle. In this case, the sampling time is obtained by shifting the largest phase U to the left. Phase U is shifted to the left by TP - [Ton(U) - Ton(V)] time, so that the shifted Ton(U) - Ton(V) = Tp, thus obtaining sufficient sampling time. Simultaneously, it is necessary to ensure the effective duty cycle of phase U, i.e., the duty cycle remains unchanged after the shift, with the entire phase shifted (both rising and falling edges). While the phase-shifting method ensures the effective duty cycle and solves the current sampling problem, it also introduces changes to the PWM waveform and waveform asymmetry, affecting control and EMC performance. To address this issue, a left-right symmetrical phase-shifting method was adopted. After completing the phase-shifting process for the first pulse width modulation cycle, the second pulse width modulation cycle underwent the opposite phase-shifting process. That is, if the maximum phase U was shifted to the left in the first pulse width modulation cycle, then the U phase in the second pulse width modulation cycle was shifted to the right, so that the waveforms of the two pulse width modulation cycles were as symmetrical as possible, thereby optimizing control and EMC performance.

[0077] S14. Collect the first current and the second current of the motor in the sampling window, construct the three-phase current of the motor based on the first current and the second current, and control the operating parameters of the compressor based on the three-phase current of the motor.

[0078] Specifically, after ensuring that the sampling windows are all greater than or equal to the shortest window width, the first and second currents of the motor are collected based on the sampling windows. Using the principle that the sum of the three-phase currents is 0, the third current is calculated based on the first and second currents, that is, the three-phase currents of the motor are constructed. The motor is controlled based on the three-phase currents, thereby realizing the control of the compressor's operating parameters.

[0079] It is worth noting that, preferably, one sampling period includes only two pulse width modulation (PWM) periods. Optionally, one sampling period may also include more than two PWM periods, wherein the PWM waveform should be kept as axially symmetric as possible for the sampling period.

[0080] Compared with the prior art, the refrigeration device disclosed in this invention has a sampling cycle that is pre-set to include a first pulse width modulation cycle and a second pulse width modulation cycle. First, a first sampling window and a second sampling window of the first pulse width modulation cycle are acquired. When the width of a sampling window is less than the preset minimum window width, on the one hand, the first pulse width modulation cycle is phase-shifted so that the width of all sampling windows is greater than or equal to the minimum window width to meet the sampling requirements. On the other hand, the second pulse width modulation cycle is phase-shifted in the opposite way to the first pulse width modulation cycle so that the waveforms in the two pulse width modulation cycles are kept as symmetrical as possible. Then, while ensuring that the sampling windows meet the sampling requirements and the waveforms in the sampling cycle are kept as symmetrical as possible, the first current and the second current of the motor are acquired to construct the three-phase current of the motor, ensuring the accuracy of current acquisition and thus ensuring the accurate construction of the three-phase current, while reducing the impact of phase shifting on the motor control performance. In addition, for the Ground Fault Circuit Interrupter (GFCI) commonly used in North America, research and testing have shown that it is sensitive to high-frequency switching signals and easily interfered with by frequency converter switching signals, leading to tripping. This embodiment improves this problem by increasing the carrier frequency while keeping the sampling period unchanged and by using symmetrical complementary phase shifting.

[0081] In a preferred embodiment, when the width of a sampling window is less than a preset minimum window width, the first pulse width modulation period is phase-shifted, and the second pulse width modulation period is phase-shifted in the opposite direction to the first pulse width modulation period, so that the widths of both the first and second sampling windows are greater than or equal to the minimum window width, including:

[0082] When the sum of the widths of the first sampling window and the second sampling window is greater than or equal to twice the preset shortest window width, and the width of the second sampling window is less than the shortest window width, the middle phase in the first pulse width modulation period is shifted to the left, and the middle phase in the second pulse width modulation period is shifted to the right, so that the widths of both the first and second sampling windows are greater than or equal to the shortest window width; wherein the middle phases in the first and second pulse width modulation periods move to the same degree, the first sampling window is determined based on the maximum and middle phases in the first pulse width modulation period, and the second sampling window is determined based on the middle and minimum phases in the first pulse width modulation period.

[0083] For example, see Figure 9 , Figure 9 This is a second flowchart of the controller provided in an embodiment of the present invention, wherein the controller is used to execute steps S1301 to S1305:

[0084] S1301. Obtain the width T1 of the first sampling window and the width T2 of the second sampling window, add T1 and T2 together, and then proceed to step S1302.

[0085] S1302. Determine whether T1 is greater than or equal to the shortest window width Tp. If yes, proceed to step S1303. If no, proceed to other control logic, such as steps S1307 to S1309.

[0086] S1303. Determine whether T1+T2 is greater than or equal to twice Tp. If yes, proceed to step S1304. If no, proceed to other control logic, such as steps S1310 to S1313.

[0087] S1304. Determine whether T2 is less than Tp. If yes, proceed to step S1305. If no, proceed to other control logic, such as step S14.

[0088] S1305. The middle phase of the PWM waveform in the first pulse width modulation period is shifted to the left, and the PWM waveform in the second pulse width modulation period is shifted complementaryly; wherein the middle phases of the first pulse width modulation period and the second pulse width modulation period shift in opposite directions and shift to the same degree.

[0089] Specifically, the phase-shifting processing method varies depending on the width of the sampling window. In this embodiment, see [link to relevant documentation]. Figure 7Assuming the width T1 of the first sampling window is the window width between the rising edges of the maximum phase U and the intermediate phase V, and the width T2 of the second sampling window is the window width between the rising edges of the intermediate phase V and the minimum phase W, with Tp being the shortest window width, if the width T1 of the first sampling window is greater than or equal to the shortest window width Tp and the width T2 of the second sampling window is less than the shortest window width Tp, then the phases associated with the second sampling window need to be moved to increase the width T2 of the second sampling window. The specific moving method needs to consider the total width of the two sampling windows. If the total width is greater than or equal to the shortest... If the window width is doubled, then the middle phase V of the PWM waveform in the first pulse width modulation cycle is shifted to the left, increasing the width T2 of the second sampling window. Simultaneously, as the width of the second sampling window increases, the width of the first sampling window decreases. However, by appropriately shifting the middle phase V to the left, the widths of both the first and second sampling windows can be greater than or equal to the shortest window width Tp. After completing the waveform shift for the first pulse width modulation cycle, the middle phase of the second pulse width modulation cycle undergoes the opposite phase shift operation, resulting in the same degree of shift for the middle phases of both cycles. It is worth noting that, preferably, "same degree of shift" means that the shift distance is completely identical under ideal conditions. However, in actual operation, some unavoidable deviations may occur. Therefore, optionally, "same degree of shift" means that the difference in shift distance does not exceed a set threshold, the specific value of which is set according to the actual situation and is not limited here.

[0090] In a preferred embodiment, when the width of a sampling window is less than a preset minimum window width, the first pulse width modulation period is phase-shifted, and the second pulse width modulation period is phase-shifted in the opposite direction to the first pulse width modulation period, so that the widths of both the first and second sampling windows are greater than or equal to the minimum window width, including:

[0091] When the sum of the widths of the first sampling window and the second sampling window is greater than or equal to twice the preset minimum window width, and the width of the first sampling window is less than the minimum window width, the middle phase in the first pulse width modulation period is controlled to shift to the right, and the middle phase in the second pulse width modulation period is controlled to shift to the left, so that the widths of both the first and second sampling windows are greater than or equal to the minimum window width; wherein, the middle phases in the first and second pulse width modulation periods move to the same degree, the first sampling window is determined based on the maximum and middle phases in the first pulse width modulation period, and the second sampling window is determined based on the middle and minimum phases in the first pulse width modulation period.

[0092] See Figure 10 , Figure 10This is a third flowchart of the controller provided in an embodiment of the present invention, wherein the controller is used to execute steps S1306 to S1309:

[0093] S1306. Obtain the width T1 of the first sampling window and the width T2 of the second sampling window, add T1 and T2 together, and then proceed to step S1307.

[0094] S1307. Determine whether T1 is less than the shortest window width Tp. If yes, proceed to step S1308. If no, proceed to other control logic, such as steps S1302 to S1305.

[0095] S1308. Determine whether T1+T2 is greater than or equal to twice Tp. If yes, proceed to step S1309. If no, proceed to other control logic, such as steps S1314 to S1317.

[0096] S1309. The middle phase of the PWM waveform in the first pulse width modulation period is shifted to the right, and the PWM waveform in the second pulse width modulation period is shifted complementaryly; wherein the middle phases of the first pulse width modulation period and the second pulse width modulation period shift in opposite directions and shift to the same degree.

[0097] Specifically, the phase-shifting processing method varies depending on the width of the sampling window. In this embodiment, see [link to relevant documentation]. Figure 7Assuming the width T1 of the first sampling window is the window width between the rising edges of the maximum phase U and the intermediate phase V, and the width T2 of the second sampling window is the window width between the rising edges of the intermediate phase V and the minimum phase W, and Tp is the shortest window width, if the width T1 of the first sampling window is less than or equal to the shortest window width Tp and the width T2 of the second sampling window is greater than or equal to the shortest window width Tp, the phases associated with the first sampling window need to be moved to increase the width T1 of the first sampling window. The specific moving method needs to consider the total width of the two sampling windows. If the total width is greater than or equal to the shortest window width... If the width of the first sampling window is increased by twice the width of the second sampling window, then the middle phase V of the PWM waveform in the first pulse width modulation cycle is shifted to the left, increasing the width T1 of the first sampling window. Simultaneously, as the width of the first sampling window increases, the width of the second sampling window decreases. However, by reasonably shifting the middle phase V to the right, the widths of both the first and second sampling windows can be greater than or equal to the shortest window width Tp. After completing the waveform shift for the first pulse width modulation cycle, the middle phase of the second pulse width modulation cycle undergoes the opposite phase shift operation. The shift directions of the middle phases in the first and second pulse width modulation cycles are opposite, and the shift degrees are the same. It is worth noting that, preferably, "the same shift degree" means that the shift distance is completely identical under ideal conditions. However, in actual operation, some unavoidable deviations may occur. Therefore, optionally, "the same shift degree" means that the difference in shift distance does not exceed a set threshold. The specific value is set according to the actual situation and is not limited here.

[0098] In a preferred embodiment, when the width of a sampling window is less than a preset minimum window width, the first pulse width modulation period is phase-shifted, and the second pulse width modulation period is phase-shifted in the opposite direction to the first pulse width modulation period, so that the widths of both the first and second sampling windows are greater than or equal to the minimum window width, including:

[0099] When the sum of the widths of the first sampling window and the second sampling window is less than twice the preset minimum window width, and the width of the first sampling window is greater than or equal to the minimum window width, the minimum phase in the first pulse width modulation period is shifted to the right, and the minimum phase in the second pulse width modulation period is shifted to the left, so that the widths of both the first and second sampling windows are greater than or equal to the minimum window width; wherein the minimum phase shifts to the same extent in the first and second pulse width modulation periods, the first sampling window is determined based on the maximum and intermediate phases in the first pulse width modulation period, and the second sampling window is determined based on the intermediate and minimum phases in the first pulse width modulation period.

[0100] For example, see Figure 11 , Figure 11This is a fourth flowchart of the controller provided in an embodiment of the present invention, wherein the controller is used to execute steps S1310 to S1313:

[0101] S1310. Obtain the width T1 of the first sampling window and the width T2 of the second sampling window, add T1 and T2 together, and then proceed to step S1311.

[0102] S1311. Determine whether T1 is greater than or equal to the shortest window width Tp. If yes, proceed to step S1312. If no, proceed to other control logic, such as steps S1307 to S1309, or steps S1315 to S1317.

[0103] S1312. Determine whether T1+T2 is less than twice Tp. If yes, proceed to step S1313. If no, proceed to other control logic, such as steps SS1301 to S1305.

[0104] S1313. The minimum phase of the PWM waveform in the first pulse width modulation period is shifted to the right, and the PWM waveform in the second pulse width modulation period is shifted complementaryly; wherein the minimum phases of the first pulse width modulation period and the second pulse width modulation period shift in opposite directions and shift to the same degree.

[0105] Specifically, the phase-shifting processing method varies depending on the width of the sampling window. In this embodiment, see [link to relevant documentation]. Figure 7Assuming the width T1 of the first sampling window is the window width between the rising edges of the maximum phase U and the intermediate phase V, and the width T2 of the second sampling window is the window width between the rising edges of the intermediate phase V and the minimum phase W, with Tp being the shortest window width, if the width T1 of the first sampling window is greater than or equal to the shortest window width Tp and the width T2 of the second sampling window is less than the shortest window width Tp, the phase associated with the second sampling window needs to be shifted to increase the width T2 of the second sampling window. The specific shifting method needs to consider the total width of the two sampling windows. If the total width is less than twice the width of the shortest window, then the minimum phase W of the PWM waveform in the first pulse width modulation period is shifted to the right to increase the width T2 of the second sampling window. At the same time, the width of the first sampling window will not decrease as the width of the second sampling window decreases. By reasonably shifting the minimum phase W to the right, the width of the second sampling window is made greater than or equal to the shortest window width Tp. After completing the waveform shifting in the first pulse width modulation period, the minimum phase of the second pulse width modulation period is shifted in the opposite direction. The intermediate phases of the first and second pulse width modulation periods are shifted to the same degree. It is worth noting that, preferably, "same degree of movement" means that the distance moved is exactly the same under ideal conditions. However, in actual operation, some unavoidable deviations may occur. Therefore, alternatively, "same degree of movement" means that the difference in the distance moved does not exceed a set threshold. The specific value is set according to the actual situation and is not limited here.

[0106] In a preferred embodiment, when the width of a sampling window is less than a preset minimum window width, the first pulse width modulation period is phase-shifted, and the second pulse width modulation period is phase-shifted in the opposite direction to the first pulse width modulation period, so that the widths of both the first and second sampling windows are greater than or equal to the minimum window width, including:

[0107] When the sum of the widths of the first sampling window and the second sampling window is less than twice the preset minimum window width, and the width of the first sampling window is less than the minimum window width, the intermediate phase and the minimum phase within the first pulse width modulation period are shifted to the right, and the intermediate phase and the minimum phase within the second pulse width modulation period are shifted to the left, so that the widths of both the first sampling window and the second sampling window are greater than or equal to the minimum window width; wherein, the intermediate phase within the first pulse width modulation period and the second pulse width modulation period shift to the same degree, the minimum phase within the first pulse width modulation period and the second pulse width modulation period shift to the same degree, the first sampling window is determined based on the maximum phase and the intermediate phase within the first pulse width modulation period, and the second sampling window is determined based on the intermediate phase and the minimum phase within the first pulse width modulation period.

[0108] See Figure 12 , Figure 12 This is the fifth workflow diagram of the controller provided in this embodiment of the invention, wherein the controller is used to execute steps S1314 to S1317:

[0109] S1314. Obtain the width T1 of the first sampling window and the width T2 of the second sampling window, add T1 and T2 together, and then proceed to step S1315.

[0110] S1315. Determine whether T1 is less than the shortest window width Tp. If yes, proceed to step S1316. If no, proceed to other control logic, such as steps S1303 to S1305, or steps S1312 to S1313, etc.

[0111] S1316. Determine whether T1+T2 is less than twice Tp. If yes, proceed to step S1317. If no, proceed to other control logic, such as step S1309.

[0112] S1317. The middle phase of the PWM waveform in the first pulse width modulation period is shifted to the right, the minimum phase of the PWM waveform in the first pulse width modulation period is shifted to the right, and the PWM waveform in the second pulse width modulation period is shifted complementaryly; wherein, the middle phases of the first pulse width modulation period and the second pulse width modulation period shift in opposite directions and shift to the same degree, and the minimum phases of the first pulse width modulation period and the second pulse width modulation period shift in opposite directions and shift to the same degree.

[0113] It is worth noting that, preferably, "same degree of movement" means that the distance moved is exactly the same under ideal conditions. However, in actual operation, some unavoidable deviations may occur. Therefore, alternatively, "same degree of movement" means that the difference in the distance moved does not exceed a set threshold. The specific value is set according to the actual situation and is not limited here.

[0114] Specifically, to make the phase shifting operation under different conditions clearer, a table is used to summarize the process. Please refer to the table below for details.

[0115]

[0116] In a preferred embodiment, the step of obtaining the sampling window of the first pulse width modulation period within the sampling period includes:

[0117] The duty cycle information of the PWM waveform in the first and second pulse width modulation periods within the new sampling period is calculated based on the historical current sampling results, in order to determine the sampling window of the first pulse width modulation period within the new sampling period; wherein, the sampling window includes a first sampling window and a second sampling window;

[0118] When the width of a sampling window is less than the preset minimum window width, the first pulse width modulation period is phase-shifted, and the second pulse width modulation period is phase-shifted in the opposite direction to the first pulse width modulation period, so that the widths of both the first and second sampling windows are greater than or equal to the minimum window width, including:

[0119] When the width of the sampling window is less than the preset minimum time window width, the PWM waveform duty cycle information of the first pulse width modulation cycle in the new sampling cycle is updated with the goal that the widths of both the first and second sampling windows are greater than the minimum time window width. Based on the principle that the PWM waveforms of the first and second pulse width modulation cycles in the same sampling cycle are axially symmetrical, the PWM waveform duty cycle information of the second pulse width modulation cycle is updated according to the adjusted PWM waveform duty cycle information of the first pulse width modulation cycle, so as to control the current parameters of the motor in the first and second pulse width modulation cycles in the new sampling cycle.

[0120] The step of acquiring the first and second currents of the motor within a sampling window with a width greater than or equal to the width of the shortest window includes:

[0121] The first acquisition time and the second acquisition time are determined based on the first target duty cycle information; wherein, the first target duty cycle information is the PWM waveform duty cycle information of the first pulse width modulation period within the new round of sampling period, and the sampling window of the first target duty cycle information is greater than or equal to the minimum time window width;

[0122] The first current and the second current of the motor are collected at the first acquisition time and the second acquisition time, respectively.

[0123] Specifically, the three-phase current constructed in the previous sampling period is used to determine the initial PWM waveform information of the first pulse width modulation period and the second pulse width adjustment period of the new sampling period, and then the initial duty cycle information is determined to determine the initial sampling window. When the sampling window is too small, the initial PWM waveform is phase-shifted to obtain the final duty cycle information. The final duty cycle information is used to determine the first acquisition time and the second acquisition time, and the motor is controlled to run. The first current and the second current of the motor are acquired at the first acquisition time and the second acquisition time to construct the three-phase current.

[0124] Furthermore, the controller is also used for:

[0125] If there is an update operation in the PWM waveform of the first pulse width modulation cycle in the new sampling cycle, the specified flag bit is set to the first specified value; if there is no update operation in the PWM waveform of the first pulse width modulation cycle in the new sampling cycle, the specified flag bit is set to the second specified value.

[0126] At the end of the previous sampling cycle, the first target duty cycle information is updated to the designated duty cycle register to control the current parameters of the motor in the new sampling cycle.

[0127] At the end of the first pulse width modulation cycle of a new sampling cycle, if the specified flag bit is the first specified value, the second target duty cycle information is updated in the duty cycle register to control the current parameters of the motor in the second pulse width modulation cycle of the new sampling cycle; wherein, the second target duty cycle information is the updated PWM waveform duty cycle information in the second pulse width modulation cycle of the new sampling cycle.

[0128] Specifically, while keeping the sampling period unchanged, the carrier frequency is increased, and the current sampling timing is not changed during the left and right complementary phase shifting process. See [link to documentation]. Figure 13 The specific operation process is as follows: Assume the sampling and calculation frequency is 5kHz, and the PWM carrier frequency is 10kHz (this can be achieved by configuring two center-aligned synchronous timing devices, TIMER1 (5kHz frequency) and TIMER2 (10kHz frequency), i.e., the sampling period is 0.0002 seconds, and the pulse width modulation period (carrier frequency period) is 0.0001 seconds. Current sampling and calculation are performed in the 5kHz interrupt. Through sampling and calculation, the three-phase duty cycle value for the next sampling period is obtained. If a phase shift operation occurs during the calculation, the flag bit is set to 1; otherwise, it is set to 0. In the 10kHz interrupt, the calculation result is updated from the buffer to the corresponding duty cycle register, generating the PWM waveform. If no phase shift operation occurs, the flag bit is 0, the duty cycle buffer value is not updated within the carrier frequency period, and the PWM waveform remains unchanged in the next carrier frequency period within the same sampling period. If the flag is set to 1, it is considered that two PWM signals within the same sampling period require complementary phase shifting. Within the period corresponding to the first 10kHz carrier frequency, the buffer value is updated again according to the complementary phase shifting principle. In the period corresponding to the next 10kHz carrier frequency, a 10kHz interrupt is entered, and the PWM duty cycle register is updated again based on the complementary phase shift buffer value of the previous 10kHz carrier frequency period, thus achieving two symmetrical phase-shifted PWM signals generated within the same sampling period. During current sampling and calculation, FOC (field-oriented control) is used for calculation, and combined with the phase shifting processing method provided in this embodiment, the duty cycle information of the first pulse width modulation period of the next sampling period is calculated.

[0129] In a preferred embodiment, the shortest window width is calculated based on the acquired ringing time, dead time, and hardware sampling time.

[0130] Specifically, for the compressor drive, a three-phase inverter circuit is set up. The three-phase inverter circuit consists of 6 switching transistors. The sampling resistor R converts the current value on the DC bus into a voltage signal. After processing by the operational amplifier, it is sent to the microcontroller unit (MCU). Since the sampling resistor R collects the bus current, while the calculation requires the phase current, the MCU triggers sampling at a specific time through the above method to obtain the phase current. By sampling twice in one cycle, the three-phase current is calculated and the six-channel duty cycle signal of the next cycle is output to control the switching transistors, thereby driving the compressor to run. From the compressor drive process, it can be seen that the determination of the shortest window width needs to consider the ringing time, dead time, and hardware sampling time. Among them, (1) Ringing time Trie: When the corresponding bridge arm switching transistor is activated, it is necessary to wait for a period of time until the voltage on the sampling resistor stabilizes before sampling. This time is defined as Trie. (2) Dead time Tdead: During the operation of a three-phase inverter circuit, the upper and lower switches on the same bridge arm are usually in a complementary output state. To prevent the same bridge arm switches from shoot-through (simultaneous activation leading to a short circuit) during switching, a dead time is usually added to the control. (3) Hardware sampling time Tad: The time from when the control circuit triggers the ADC to complete sampling; where ADC stands for Analog-to-Digital Converter. In summary, the minimum window width Tp is set as follows: ringing time Trie + dead time Tdead + hardware sampling time Tad.

[0131] Compared with the prior art, the refrigeration device disclosed in this invention has a sampling cycle that is pre-set to include a first pulse width modulation (PWM) cycle and a second PWM cycle. First, a first sampling window and a second sampling window of the first PWM cycle are acquired. When the width of a sampling window is less than the preset minimum window width, on the one hand, the first PWM cycle is phase-shifted so that the width of all sampling windows is greater than or equal to the minimum window width to meet the sampling requirements. On the other hand, the second PWM cycle is phase-shifted in the opposite direction to the first PWM cycle so that the waveforms within the two PWM cycles are kept as symmetrical as possible. Then, while ensuring that the sampling windows meet the sampling requirements and the waveforms within the sampling cycle are kept as symmetrical as possible, the first current and the second current of the motor are acquired to construct the three-phase current of the motor for controlling the compressor of the refrigeration device. This ensures the accuracy of current acquisition, thereby ensuring the accurate construction of the three-phase current, while reducing the impact of phase shifting on the motor control performance and improving the compressor control performance.

[0132] See Figure 14 , Figure 14 This is a flowchart illustrating a method for constructing three-phase current in a motor according to an embodiment of the present invention. The method described in this embodiment includes steps S1 to S4:

[0133] S1. Obtain the sampling window of the first pulse width modulation period within the sampling period; wherein, the sampling period includes the first pulse width modulation period and the second pulse width modulation period, and the sampling window includes a first sampling window and a second sampling window;

[0134] S2. When the width of a sampling window is less than the preset minimum window width, the first pulse width modulation period is phase-shifted, and the second pulse width modulation period is phase-shifted in the opposite direction to the first pulse width modulation period, so that the widths of the first sampling window and the second sampling window are both greater than or equal to the minimum window width.

[0135] S3. Collect the first current and the second current of the motor in a sampling window whose width is greater than or equal to the width of the shortest window;

[0136] S4. Construct the three-phase current of the motor based on the first current and the second current.

[0137] In one implementation, when the width of a sampling window is less than a preset minimum window width, the first pulse width modulation period is phase-shifted, and the second pulse width modulation period is phase-shifted in the opposite direction to the first pulse width modulation period, so that the widths of both the first and second sampling windows are greater than or equal to the minimum window width, including:

[0138] When the sum of the widths of the first sampling window and the second sampling window is greater than or equal to twice the preset shortest window width, and the width of the second sampling window is less than the shortest window width, the middle phase in the first pulse width modulation period is shifted to the left, and the middle phase in the second pulse width modulation period is shifted to the right, so that the widths of both the first and second sampling windows are greater than or equal to the shortest window width; wherein the middle phases in the first and second pulse width modulation periods move to the same degree, the first sampling window is determined based on the maximum and middle phases in the first pulse width modulation period, and the second sampling window is determined based on the middle and minimum phases in the first pulse width modulation period.

[0139] In one implementation, when the width of a sampling window is less than a preset minimum window width, the first pulse width modulation period is phase-shifted, and the second pulse width modulation period is phase-shifted in the opposite direction to the first pulse width modulation period, so that the widths of both the first and second sampling windows are greater than or equal to the minimum window width, including:

[0140] When the sum of the widths of the first sampling window and the second sampling window is greater than or equal to twice the preset minimum window width, and the width of the first sampling window is less than the minimum window width, the middle phase in the first pulse width modulation period is controlled to shift to the right, and the middle phase in the second pulse width modulation period is controlled to shift to the left, so that the widths of both the first and second sampling windows are greater than or equal to the minimum window width; wherein, the middle phases in the first and second pulse width modulation periods move to the same degree, the first sampling window is determined based on the maximum and middle phases in the first pulse width modulation period, and the second sampling window is determined based on the middle and minimum phases in the first pulse width modulation period.

[0141] In one implementation, when the width of a sampling window is less than a preset minimum window width, the first pulse width modulation period is phase-shifted, and the second pulse width modulation period is phase-shifted in the opposite direction to the first pulse width modulation period, so that the widths of both the first and second sampling windows are greater than or equal to the minimum window width, including:

[0142] When the sum of the widths of the first sampling window and the second sampling window is less than twice the preset minimum window width, and the width of the second sampling window is less than the minimum window width, the minimum phase in the first pulse width modulation period is shifted to the right, and the minimum phase in the second pulse width modulation period is shifted to the left, so that the widths of the first sampling window and the second sampling window are both greater than or equal to the minimum window width; wherein, the minimum phase shifts to the same extent in the first pulse width modulation period and the second pulse width modulation period, the first sampling window is determined based on the maximum phase and the intermediate phase in the first pulse width modulation period, and the second sampling window is determined based on the intermediate phase and the minimum phase in the first pulse width modulation period.

[0143] In one implementation, when the width of a sampling window is less than a preset minimum window width, the first pulse width modulation period is phase-shifted, and the second pulse width modulation period is phase-shifted in the opposite direction to the first pulse width modulation period, so that the widths of both the first and second sampling windows are greater than or equal to the minimum window width, including:

[0144] When the sum of the widths of the first sampling window and the second sampling window is less than twice the preset minimum window width, and the width of the first sampling window is less than the minimum window width, the intermediate phase and the minimum phase within the first pulse width modulation period are shifted to the right, and the intermediate phase and the minimum phase within the second pulse width modulation period are shifted to the left, so that the widths of both the first sampling window and the second sampling window are greater than or equal to the minimum window width; wherein, the intermediate phase within the first pulse width modulation period and the second pulse width modulation period shift to the same degree, the minimum phase within the first pulse width modulation period and the second pulse width modulation period shift to the same degree, the first sampling window is determined based on the maximum phase and the intermediate phase within the first pulse width modulation period, and the second sampling window is determined based on the intermediate phase and the minimum phase within the first pulse width modulation period.

[0145] In one embodiment, the step of acquiring the sampling window of the first pulse width modulation period within the sampling period includes:

[0146] The duty cycle information of the PWM waveform in the first and second pulse width modulation periods within the new sampling period is calculated based on the historical current sampling results, in order to determine the sampling window of the first pulse width modulation period within the new sampling period; wherein, the sampling window includes a first sampling window and a second sampling window;

[0147] When the width of a sampling window is less than the preset minimum window width, the first pulse width modulation period is phase-shifted, and the second pulse width modulation period is phase-shifted in the opposite direction to the first pulse width modulation period, so that the widths of both the first and second sampling windows are greater than or equal to the minimum window width, including:

[0148] When the width of the sampling window is less than the preset minimum time window width, the PWM waveform duty cycle information of the first pulse width modulation cycle in the new sampling cycle is updated with the goal that the widths of both the first and second sampling windows are greater than the minimum time window width. Based on the principle that the PWM waveforms of the first and second pulse width modulation cycles in the same sampling cycle are axially symmetrical, the PWM waveform duty cycle information of the second pulse width modulation cycle is updated according to the adjusted PWM waveform duty cycle information of the first pulse width modulation cycle, so as to control the current parameters of the motor in the first and second pulse width modulation cycles in the new sampling cycle.

[0149] The step of acquiring the first and second currents of the motor within a sampling window with a width greater than or equal to the width of the shortest window includes:

[0150] The first acquisition time and the second acquisition time are determined based on the first target duty cycle information; wherein, the first target duty cycle information is the PWM waveform duty cycle information of the first pulse width modulation period within the new round of sampling period, and the sampling window of the first target duty cycle information is greater than or equal to the minimum time window width;

[0151] The first current and the second current of the motor are collected at the first acquisition time and the second acquisition time, respectively.

[0152] It is worth noting that the specific steps of the method described in the above embodiments can be found in the working process of the controller of the refrigeration equipment in the above embodiments, and will not be repeated here.

[0153] Compared to existing technologies, the method disclosed in this invention pre-sets a sampling period to include a first pulse width modulation (PWM) period and a second PWM period. First, a first sampling window and a second sampling window of the first PWM period are acquired. When the width of a sampling window is less than a preset minimum window width, on the one hand, the first PWM period is phase-shifted to ensure that the width of all sampling windows is greater than or equal to the minimum window width to meet sampling requirements. On the other hand, the second PWM period is phase-shifted in the opposite direction to the first PWM period to maintain the waveforms within the two PWM periods as symmetrical as possible. Then, while ensuring that the sampling windows meet the sampling requirements and that the waveforms within the sampling period maintain symmetry as much as possible, the first and second currents of the motor are acquired to construct the three-phase currents of the motor. This ensures the accuracy of current acquisition, thereby guaranteeing the accurate construction of the three-phase currents, while reducing the impact of phase shifting on motor control performance.

[0154] This embodiment also provides a home appliance product, including a home appliance body and a controller. The home appliance body includes a motor and a driven device, and the motor is used to drive the driven device to operate.

[0155] It's worth noting that home appliances can include washing machines, refrigerators, air conditioners, range hoods, and other appliances equipped with motors. For washing machines, the driven device is the drum or pulsator; the motor drives the drum to rotate or the pulsator to rotate in either direction. For refrigeration equipment like refrigerators and air conditioners, the driven device is the compressor's compression mechanism; the motor drives the compressor to compress the refrigerant, providing power for the refrigeration cycle. For range hoods, the driven device is an axial fan, fan cabinet, or centrifugal fan; the motor drives the axial fan, fan cabinet, or centrifugal fan. It's also important to note that home appliances are not limited to the specific product types mentioned above; the scope and specific driven device of the appliance can be determined based on the actual situation.

[0156] The controller of the home appliance is specifically used for: acquiring a sampling window of a first pulse width modulation period within a sampling period; wherein the sampling period includes the first pulse width modulation period and a second pulse width modulation period, and the sampling window includes a first sampling window and a second sampling window; when the width of a sampling window is less than a preset minimum window width, performing phase shifting processing on the first pulse width modulation period and performing phase shifting processing on the second pulse width modulation period in the opposite direction to the first pulse width modulation period, so that the widths of the first sampling window and the second sampling window are both greater than or equal to the minimum window width; acquiring the first current and the second current of the motor within the sampling window whose width is greater than or equal to the minimum window width; constructing the three-phase current of the motor based on the first current and the second current; and controlling the operating parameters of the motor based on the three-phase current to drive the driven device to operate.

[0157] It is worth noting that the specific working process of the controller of the home appliance product described in the above embodiments can be found in the specific steps of the motor three-phase current construction method described in the above embodiments, and will not be repeated here.

[0158] Compared to existing technologies, the home appliance product disclosed in this invention has a sampling period pre-set to include a first pulse width modulation (PWM) period and a second PWM period. First, a first sampling window and a second sampling window of the first PWM period are acquired. When the width of a sampling window is less than the preset minimum window width, on the one hand, the first PWM period is phase-shifted to ensure that the width of all sampling windows is greater than or equal to the minimum window width to meet the sampling requirements. On the other hand, the second PWM period is phase-shifted in the opposite direction to the first PWM period to ensure that the waveforms within the two PWM periods are as symmetrical as possible. Then, while ensuring that the sampling windows meet the sampling requirements and that the waveforms within the sampling period are as symmetrical as possible, the first current and the second current of the motor are acquired to construct the three-phase current of the motor for control of the driven device. This ensures the accuracy of current acquisition, thereby ensuring the accurate construction of the three-phase current and reducing the impact of phase shifting on motor control performance.

[0159] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A method for constructing three-phase current in a motor, characterized in that, include: Obtain the sampling window of the first pulse width modulation period within the sampling period; wherein, the sampling period includes the first pulse width modulation period and the second pulse width modulation period, and the sampling window includes a first sampling window and a second sampling window; When the width of a sampling window is less than the preset minimum window width, the first pulse width modulation period is phase-shifted, and the second pulse width modulation period is phase-shifted in the opposite direction to the first pulse width modulation period, so that the widths of the first sampling window and the second sampling window are both greater than or equal to the minimum window width. The first and second currents of the motor are collected in a sampling window whose width is greater than or equal to the width of the shortest window. The three-phase current of the motor is constructed based on the first current and the second current.

2. The method for constructing three-phase current of a motor as described in claim 1, characterized in that, When the width of a sampling window is less than the preset minimum window width, the first pulse width modulation period is phase-shifted, and the second pulse width modulation period is phase-shifted in the opposite direction to the first pulse width modulation period, so that the widths of both the first and second sampling windows are greater than or equal to the minimum window width, including: When the sum of the widths of the first sampling window and the second sampling window is greater than or equal to twice the preset shortest window width, and the width of the second sampling window is less than the shortest window width, the middle phase in the first pulse width modulation period is shifted to the left, and the middle phase in the second pulse width modulation period is shifted to the right, so that the widths of both the first and second sampling windows are greater than or equal to the shortest window width; wherein the middle phases in the first and second pulse width modulation periods move to the same degree, the first sampling window is determined based on the maximum and middle phases in the first pulse width modulation period, and the second sampling window is determined based on the middle and minimum phases in the first pulse width modulation period.

3. The method for constructing three-phase current of a motor as described in claim 1, characterized in that, When the width of a sampling window is less than the preset minimum window width, the first pulse width modulation period is phase-shifted, and the second pulse width modulation period is phase-shifted in the opposite direction to the first pulse width modulation period, so that the widths of both the first and second sampling windows are greater than or equal to the minimum window width, including: When the sum of the widths of the first sampling window and the second sampling window is greater than or equal to twice the preset minimum window width, and the width of the first sampling window is less than the minimum window width, the middle phase in the first pulse width modulation period is controlled to shift to the right, and the middle phase in the second pulse width modulation period is controlled to shift to the left, so that the widths of both the first and second sampling windows are greater than or equal to the minimum window width; wherein, the middle phases in the first and second pulse width modulation periods move to the same degree, the first sampling window is determined based on the maximum and middle phases in the first pulse width modulation period, and the second sampling window is determined based on the middle and minimum phases in the first pulse width modulation period.

4. The method for constructing three-phase current of a motor as described in claim 1, characterized in that, When the width of a sampling window is less than the preset minimum window width, the first pulse width modulation period is phase-shifted, and the second pulse width modulation period is phase-shifted in the opposite direction to the first pulse width modulation period, so that the widths of both the first and second sampling windows are greater than or equal to the minimum window width, including: When the sum of the widths of the first sampling window and the second sampling window is less than twice the preset minimum window width, and the width of the first sampling window is greater than or equal to the minimum window width, the minimum phase in the first pulse width modulation period is shifted to the right, and the minimum phase in the second pulse width modulation period is shifted to the left, so that the widths of both the first and second sampling windows are greater than or equal to the minimum window width; wherein the minimum phase shifts to the same extent in the first and second pulse width modulation periods, the first sampling window is determined based on the maximum and intermediate phases in the first pulse width modulation period, and the second sampling window is determined based on the intermediate and minimum phases in the first pulse width modulation period.

5. The method for constructing three-phase current of a motor as described in claim 1, characterized in that, When the width of a sampling window is less than the preset minimum window width, the first pulse width modulation period is phase-shifted, and the second pulse width modulation period is phase-shifted in the opposite direction to the first pulse width modulation period, so that the widths of both the first and second sampling windows are greater than or equal to the minimum window width, including: When the sum of the widths of the first sampling window and the second sampling window is less than twice the preset minimum window width, and the width of the first sampling window is less than the minimum window width, the intermediate phase and the minimum phase within the first pulse width modulation period are shifted to the right, and the intermediate phase and the minimum phase within the second pulse width modulation period are shifted to the left, so that the widths of both the first sampling window and the second sampling window are greater than or equal to the minimum window width; wherein, the intermediate phase within the first pulse width modulation period and the second pulse width modulation period shift to the same degree, the minimum phase within the first pulse width modulation period and the second pulse width modulation period shift to the same degree, the first sampling window is determined based on the maximum phase and the intermediate phase within the first pulse width modulation period, and the second sampling window is determined based on the intermediate phase and the minimum phase within the first pulse width modulation period.

6. The method for constructing three-phase current of a motor as described in claim 1, characterized in that, The sampling window for obtaining the first pulse width modulation period within the sampling period includes: The duty cycle information of the PWM waveform in the first and second pulse width modulation periods within the new sampling period is calculated based on the historical current sampling results, in order to determine the sampling window of the first pulse width modulation period within the new sampling period; wherein, the sampling window includes a first sampling window and a second sampling window; When the width of a sampling window is less than the preset minimum window width, the first pulse width modulation period is phase-shifted, and the second pulse width modulation period is phase-shifted in the opposite direction to the first pulse width modulation period, so that the widths of both the first and second sampling windows are greater than or equal to the minimum window width, including: When the width of the sampling window is less than the preset minimum time window width, the PWM waveform duty cycle information of the first pulse width modulation cycle in the new sampling cycle is updated with the goal that the widths of both the first and second sampling windows are greater than the minimum time window width. Based on the principle that the PWM waveforms of the first and second pulse width modulation cycles in the same sampling cycle are axially symmetrical, the PWM waveform duty cycle information of the second pulse width modulation cycle is updated according to the adjusted PWM waveform duty cycle information of the first pulse width modulation cycle, so as to control the current parameters of the motor in the first and second pulse width modulation cycles in the new sampling cycle. The step of acquiring the first and second currents of the motor within a sampling window with a width greater than or equal to the width of the shortest window includes: The first acquisition time and the second acquisition time are determined based on the first target duty cycle information; wherein, the first target duty cycle information is the PWM waveform duty cycle information of the first pulse width modulation period within the new round of sampling period, and the sampling window of the first target duty cycle information is greater than or equal to the minimum time window width; The first current and the second current of the motor are collected at the first acquisition time and the second acquisition time, respectively.

7. The method for constructing three-phase current of a motor as described in claim 6, characterized in that, Also includes: If there is an update operation in the PWM waveform of the first pulse width modulation cycle in the new sampling cycle, the specified flag bit is set to the first specified value; if there is no update operation in the PWM waveform of the first pulse width modulation cycle in the new sampling cycle, the specified flag bit is set to the second specified value. At the end of the previous sampling cycle, the first target duty cycle information is updated to the designated duty cycle register to control the current parameters of the motor in the new sampling cycle. At the end of the first pulse width modulation cycle of a new sampling cycle, if the specified flag bit is the first specified value, the second target duty cycle information is updated in the duty cycle register to control the current parameters of the motor in the second pulse width modulation cycle of the new sampling cycle; wherein, the second target duty cycle information is the updated PWM waveform duty cycle information in the second pulse width modulation cycle of the new sampling cycle.

8. The method for constructing three-phase current of a motor as described in claim 1, characterized in that, The shortest window width is obtained by adding the acquired ringing time, dead time, and hardware sampling time.

9. A refrigeration device, characterized in that, include: The refrigerant circuit circulates refrigerant sequentially through a compressor, condenser, pressure reducer, and evaporator; The compressor has a motor and a compression mechanism inside its cavity. The motor is used to drive the compression mechanism to compress the refrigerant and provide power for the refrigeration cycle. The controller is configured to perform the method as described in any one of claims 1 to 8, and further configured to control the operating parameters of the compressor based on the three-phase current of the motor.

10. A household appliance, characterized in that, include: The appliance body includes a motor and a driven device, wherein the motor is used to drive the driven device to operate. The controller is configured to perform the method as described in any one of claims 1 to 8, and is further configured to control the operating parameters of the motor according to the three-phase current of the motor, so as to drive the driven device to operate.

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