Power conversion device, refrigeration equipment and control method and controller of PFC (Power Factor Correction) circuit of refrigeration equipment

Abstract

The invention discloses a power conversion device, refrigeration equipment, a control method of a PFC circuit of the refrigeration equipment and a controller, the power conversion device is suitable for converting an input alternating current power supply into a direct current power supply so as to supply power to a compressor of the refrigeration equipment, and the power conversion device comprises a conversion bridge which comprises a plurality of components and is provided with an input end and an output end; the inductor is connected between an alternating current power supply and the input end; the capacitor is connected to the output end and is suitable for carrying out voltage stabilization processing on the output voltage of the conversion bridge so as to provide a direct-current power supply; and the controller is configured to determine a temperature slope according to the temperature information and control the switching tubes in the plurality of components according to the temperature slope so as to switch working modes of the conversion bridge, and the working modes of the conversion bridge comprise a discontinuous conduction mode and a continuous conduction mode. According to the device, the working mode of the conversion bridge can be switched according to the temperature slope of the indoor environment, the room temperature can be accurately tracked, the comfort of the indoor environment is improved, and the efficiency can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of refrigeration equipment, and in particular, to a power conversion device, a refrigeration equipment, a control method for a PFC (Power Factor Correction) circuit in a refrigeration equipment, a computer-readable storage medium, and a controller. Background Art

[0002] In related technologies, during the operation of refrigeration equipment such as air conditioners, the switching control of the compressor working mode is usually performed using a shunt resistor or a current sensor, that is, the current flowing in the compressor is used as a threshold to determine whether to switch the compressor working mode. However, the switching control using a shunt resistor or a current sensor only relies on the current flowing in the compressor, so that the compressor working mode cannot fully conform to the indoor environment, and the comfort of the indoor environment is poor. Summary of the Invention

[0003] The present invention aims to at least solve one of the technical problems in the related technologies to some extent. For this purpose, the first object of the present invention is to provide a power conversion device that can switch the working mode of the conversion bridge according to the temperature slope of the indoor environment, can accurately track the room temperature, improve the comfort of the indoor environment, and can improve the efficiency.

[0004] The second object of the present invention is to provide a refrigeration equipment.

[0005] The third object of the present invention is to provide a control method for a PFC circuit in a refrigeration equipment.

[0006] The fourth object of the present invention is to provide a computer-readable storage medium.

[0007] The fifth object of the present invention is to provide a controller.

[0008] The sixth object of the present invention is to provide another refrigeration equipment.

[0009] To achieve the above object, an embodiment of the first aspect of the present invention provides a power conversion device adapted to convert an input AC power supply into a DC power supply to supply power to a compressor of a refrigeration device. The power conversion device includes: a conversion bridge, which includes a plurality of components connected in a bridge shape and configured with an input end and an output end; an inductor connected between the AC power supply and the input end; a capacitor connected to the output end and adapted to stabilize the output voltage of the conversion bridge to provide the DC power supply; a temperature detector adapted to detect the indoor ambient temperature to obtain temperature information; and a controller configured to determine a temperature slope based on the temperature information and control a switching transistor among the plurality of components according to the temperature slope to switch the operating mode of the conversion bridge, where the operating modes of the conversion bridge include a discontinuous conduction mode and a continuous conduction mode.

[0010] According to the power conversion device of the embodiment of the present invention, the capacitor is used to stabilize the output voltage of the conversion bridge to provide a DC power supply. The temperature detector detects the indoor ambient temperature to obtain temperature information. The controller determines the temperature slope based on the temperature information and controls the switching transistor among the plurality of components according to the temperature slope to switch the operating mode of the conversion bridge between the discontinuous conduction mode and the continuous conduction mode. Thus, the device can switch the operating mode of the conversion bridge according to the temperature slope of the indoor environment, accurately track the room temperature, improve the comfort of the indoor environment, and improve the efficiency.

[0011] In addition, according to the power conversion device of the above embodiment of the present invention, the following additional technical features may also be provided:

[0012] According to an embodiment of the present invention, the plurality of components include a first switching transistor, a second switching transistor, a first freewheeling device, and a second freewheeling device. The first switching transistor and the second switching transistor form a first bridge arm, and the first freewheeling device and the second freewheeling device form a second bridge arm. The midpoints of the first bridge arm and the second bridge arm serve as the input end, and the two ends of the first bridge arm or the second bridge arm serve as the output end. The midpoint of the first bridge arm is connected to the AC power supply through the inductor.

[0013] According to an embodiment of the present invention, the first switching transistor and the second switching transistor in the first bridge arm are high-side power devices, and the first freewheeling device and the second freewheeling device in the second bridge arm are low-side freewheeling devices.

[0014] According to an embodiment of the present invention, the first switching transistor and the second switching transistor are gallium nitride MOSFETs respectively, and the first freewheeling device and the second freewheeling device are diodes respectively.

[0015] According to an embodiment of the present invention, the temperature detector is disposed at the air inlet of the indoor unit of the refrigeration device.

[0016] According to an embodiment of the present invention, when the conversion bridge operates in the discontinuous conduction mode, the first switching tube and the second switching tube are respectively turned on or off at intervals, and the first switching tube and the second switching tube are alternately turned on or off.

[0017] According to an embodiment of the present invention, when the conversion bridge operates in the continuous conduction mode, the first switching tube and the second switching tube are respectively continuously turned on or off, and the first switching tube and the second switching tube are alternately turned on or off.

[0018] According to an embodiment of the present invention, the controller includes a Kalman filter, and processes the temperature information within a target time period through the Kalman filter to obtain the temperature slope.

[0019] According to another embodiment of the present invention, the controller processes the temperature information within a target time period based on the recursive line approximation method to obtain the temperature slope.

[0020] To achieve the above object, an embodiment of the second aspect of the present invention provides a refrigeration device, including: a compressor; the above-mentioned power conversion device, which is adapted to convert the input AC power supply into a DC power supply to supply power to the compressor.

[0021] The refrigeration device according to the embodiment of the present invention can switch the working mode of the conversion bridge according to the temperature slope of the indoor environment through the above-mentioned power conversion device, can accurately track the room temperature, improve the comfort of the indoor environment, and can improve the efficiency.

[0022] To achieve the above object, an embodiment of the third aspect of the present invention provides a control method for a PFC circuit in a refrigeration device, the method including: detecting the indoor environment temperature to obtain temperature information; determining a temperature slope according to the temperature information, and controlling a switching tube in the PFC circuit according to the temperature slope to switch the working mode of the PFC circuit, where the working modes of the PFC circuit include a discontinuous conduction mode and a continuous conduction mode.

[0023] According to the control method of the PFC circuit in the refrigeration equipment according to an embodiment of the present invention, first, the indoor ambient temperature is detected to obtain temperature information, then the temperature slope is determined according to the temperature information, and the switching tube in the PFC circuit is controlled according to the temperature slope to switch the working mode of the PFC circuit between the discontinuous conduction mode and the continuous conduction mode. Thus, this method can switch the working mode of the PFC circuit according to the temperature slope of the indoor environment, can accurately track the room temperature, improve the comfort of the indoor environment, and can improve the efficiency.

[0024] In addition, the control method of the PFC circuit in the refrigeration equipment according to the above embodiment of the present invention may further have the following additional technical features:

[0025] According to an embodiment of the present invention, determining the temperature slope according to the temperature information includes: processing the temperature information within a target time period by using a Kalman filter to obtain the temperature slope.

[0026] According to another embodiment of the present invention, determining the temperature slope according to the temperature information includes: processing the temperature information within a target time period based on the recursive line approximation method to obtain the temperature slope.

[0027] According to an embodiment of the present invention, controlling the switching tube in the PFC circuit according to the temperature slope includes: when the temperature slope is greater than or equal to a first set threshold, controlling the first switching tube and the second switching tube to be continuously turned on or off respectively, and the first switching tube and the second switching tube are alternately turned on or off, so that the PFC circuit operates in the continuous conduction mode; when the temperature slope is less than the first set threshold, controlling the first switching tube and the second switching tube to be turned on or off at intervals respectively, and the first switching tube and the second switching tube are alternately turned on or off, so that the PFC circuit operates in the discontinuous conduction mode.

[0028] According to an embodiment of the present invention, the discontinuous conduction mode includes a first Burst control mode and a second Burst control mode. Wherein, when the temperature slope is less than the first set threshold, the method further includes: if the temperature slope is greater than or equal to a second set threshold, controlling the PFC circuit to operate in the first Burst control mode, where the second set threshold is less than the first set threshold; if the temperature slope is less than the second set threshold, controlling the PFC circuit to operate in the second Burst control mode, where the duty cycle corresponding to the second Burst control mode is less than the duty cycle corresponding to the first Burst control mode.

[0029] To achieve the above object, an embodiment of the fourth aspect of the present invention provides a computer-readable storage medium, on which a control program for a PFC circuit in a refrigeration device is stored. When the program is executed by a processor, the control method for the PFC circuit in the refrigeration device described above is implemented.

[0030] According to the computer-readable storage medium of the embodiment of the present invention, through the above control method for the PFC circuit in the refrigeration device, the working mode of the PFC circuit can be switched according to the temperature slope of the indoor environment, the room temperature can be accurately tracked, the comfort of the indoor environment can be improved, and the efficiency can be improved.

[0031] To achieve the above object, an embodiment of the fifth aspect of the present invention provides a controller, including: a memory, a processor, and a control program for a PFC circuit in a refrigeration device stored on the memory and executable on the processor. When the processor executes the program, the control method for the PFC circuit in the refrigeration device described above is implemented.

[0032] According to the controller of the embodiment of the present invention, through the above control method for the PFC circuit in the refrigeration device, the working mode of the PFC circuit can be switched according to the temperature slope of the indoor environment, the room temperature can be accurately tracked, the comfort of the indoor environment can be improved, and the efficiency can be improved.

[0033] To achieve the above object, an embodiment of the sixth aspect of the present invention provides a refrigeration device, including: a compressor; a PFC circuit adapted to provide a DC power supply to the compressor, the working modes of the PFC circuit including a discontinuous conduction mode and a continuous conduction mode; a temperature detector adapted to detect the indoor environment temperature to obtain temperature information; a controller configured to determine a temperature slope according to the temperature information and control a switching tube in the PFC circuit according to the temperature slope to switch the working mode of the PFC circuit.

[0034] According to the refrigeration device of the embodiment of the present invention, a DC power supply is provided to the compressor through the PFC circuit, the indoor environment temperature is detected by the temperature detector to obtain temperature information, the controller determines the temperature slope according to the temperature information, and controls the switching tube in the PFC circuit according to the temperature slope to switch the working mode of the PFC circuit between the discontinuous conduction mode and the continuous conduction mode. Thus, the device can switch the working mode of the PFC circuit according to the temperature slope of the indoor environment, accurately track the room temperature, improve the comfort of the indoor environment, and improve the efficiency.

[0035] Additional aspects and advantages of the present invention will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present invention. Description of the Drawings

[0036] Figure 1 Schematic block diagram of a power conversion device according to an embodiment of the present invention;

[0037] Figure 2 Schematic diagram of the current flow direction during the positive half - cycle of an AC power supply in a discontinuous conduction mode of a conversion bridge according to an embodiment of the present invention;

[0038] Figure 3 Schematic diagram of the current flow direction during the negative half - cycle of an AC power supply in a discontinuous conduction mode of a conversion bridge according to an embodiment of the present invention;

[0039] Figure 4 Schematic diagram of the current flow direction during the positive half - cycle of an AC power supply in a continuous conduction mode of a conversion bridge according to an embodiment of the present invention;

[0040] Figure 5 Schematic diagram of the current flow direction during the positive half - cycle of an AC power supply in a continuous conduction mode of a conversion bridge according to an embodiment of the present invention;

[0041] Figure 6 Schematic block diagram of a refrigeration device according to an embodiment of the present invention;

[0042] Figure 7 Flowchart of a control method for a PFC circuit in a refrigeration device according to an embodiment of the present invention;

[0043] Figure 8 Hardware topology diagram of a PFC circuit in a refrigeration device according to an embodiment of the present invention;

[0044] Figure 9 Schematic block diagram of a controller according to an embodiment of the present invention;

[0045] Figure 10 Schematic block diagram of a refrigeration device according to an embodiment of the present invention. Detailed implementation manners

[0046] The embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present invention, and should not be construed as limiting the present invention.

[0047] The power conversion device, refrigeration device, control method for a PFC circuit in a refrigeration device, computer - readable storage medium, and controller proposed according to embodiments of the present invention will be described below with reference to the accompanying drawings.

[0048] Figure 1 Schematic block diagram of a power conversion device according to an embodiment of the present invention.

[0049] As shown Figure 1 in FIG. 1, the power conversion device 100 according to an embodiment of the present invention is adapted to convert an input AC power supply AC into a DC power supply to supply power to a compressor of a refrigeration device. The power conversion device 100 may include: a conversion bridge 110, an inductor L1, a capacitor C1, a temperature detector 120, and a controller 130.

[0050] Among them, the conversion bridge 110 includes a plurality of components, which are connected in a bridge shape and are configured with an input end and an output end. It should be noted that the circuit in which the plurality of components are connected in a bridge shape can be a half-bridge circuit, an H-bridge circuit, a three-phase bridge circuit, etc., and no specific limitation is made thereto.

[0051] The inductor L1 is connected between the AC power supply AC and the input end. The inductor L1 can store the power supplied from the AC power supply AC and improve the voltage boost and power factor by releasing the stored energy.

[0052] The capacitor C1 is connected to the output end and is adapted to perform voltage stabilization processing on the output voltage of the conversion bridge to provide a DC power supply.

[0053] The temperature detector 120 is adapted to detect the indoor environmental temperature and obtain temperature information. The controller 130 is configured to determine a temperature slope according to the temperature information and control a switching transistor among the plurality of components according to the temperature slope to switch the working mode of the conversion bridge 110, where the working mode of the conversion bridge 110 includes a discontinuous conduction mode and a continuous conduction mode.

[0054] Specifically, the electric energy provided by the AC power supply AC is input into the conversion bridge 110 through the inductor L1. The capacitor C1 can smooth the voltage output from the conversion bridge 110 into a DC voltage and output it to the compressor of the refrigeration device to supply power to the compressor. After the compressor operates, the refrigeration device can heat or cool the indoor environment according to the user's needs. During the operation of the compressor, the temperature detector 120 detects the indoor environment temperature in real time, obtains the temperature information, and transmits it to the controller 130. The controller 130 can calculate the temperature slope from the discrete sampled temperature data within an arbitrary time range, and can control the switching tube among multiple components according to the temperature slope to switch the working mode of the conversion bridge 110 between the discontinuous conduction mode and the continuous conduction mode. Taking the refrigeration device cooling the indoor environment as an example, at the initial stage of refrigeration, the temperature of the indoor environment decreases from high to low and the change speed is relatively fast. At this time, the corresponding temperature slope is large, indicating that the refrigeration load is high at this time. The controller 130 can drive the compressor in the continuous conduction mode with the conversion bridge 110. As the refrigeration progresses, the temperature of the indoor environment gradually approaches the set temperature. At this time, the corresponding temperature slope is small, indicating that the refrigeration load is low at this time. The controller 130 can drive the compressor in the discontinuous conduction mode with the conversion bridge 110. Thus, by switching the operation mode of the compressor motor, the efficiency of the compressor and the circuit can be improved, and the room temperature can be accurately tracked, improving the comfort of the indoor environment and the efficiency.

[0055] According to an embodiment of the present invention, as Figure 1 shown, the multiple components include a first switching tube Q1, a second switching tube Q2, a first freewheeling device D1, and a second freewheeling device D2. The first switching tube Q1 and the second switching tube Q2 form a first bridge arm 111, the first freewheeling device D1 and the second freewheeling device D2 form a second bridge arm 112. The midpoint of the first bridge arm 111 and the midpoint of the second bridge arm 112 are used as the input terminals, and the two ends of the first bridge arm 111 or the second bridge arm 112 are used as the output terminals. The midpoint of the first bridge arm 111 is connected to the AC power supply AC through the inductor L1.

[0056] Specifically, as Figure 1As shown, the first switching transistor Q1 and the second switching transistor Q2 are connected in series with each other to form a first leg 111. Among them, the first switching transistor Q1 is the upper-bridge switching transistor of the first leg 111, and the second switching transistor Q2 is the lower-bridge switching transistor of the first leg 111. The anode of the first freewheeling device D1 and the cathode of the second freewheeling device D2 are connected in series to form a second leg 112. One end of the inductor L1 is connected to one end of the AC power supply AC, and the other end of the inductor L1 is connected to the connection point of the first switching transistor Q1 and the second switching transistor Q2. The positive electrode of the capacitor C1 is connected to the drain of the first switching transistor Q1 and the cathode of the first freewheeling device D1 in the second leg 112, and the negative electrode is connected to the source of the lower-bridge switching transistor in the first leg 111 and the anode of the second freewheeling device D2 in the second leg 112. The controller 130 is respectively connected to the control terminals of the first switching transistor Q1 and the second switching transistor Q2.

[0057] Further, according to an embodiment of the present invention, the first switching transistor Q1 and the second switching transistor Q2 in the first leg 111 are high-side power devices, and the first freewheeling device D1 and the second freewheeling device D2 in the second leg 112 are low-side freewheeling devices.

[0058] According to an embodiment of the present invention, the first switching transistor Q1 and the second switching transistor Q2 are gallium nitride MOSFETs respectively, and the first freewheeling device D1 and the second freewheeling device D2 are diodes respectively.

[0059] It should be understood that traditional silicon carbide MOSFETs have built-in freewheeling diodes and have recovery losses during turn-off, making it difficult to improve efficiency at switching frequencies (such as higher than 20 kHz), and the silicon carbide MOSFETs have relatively large volumes. In comparison, gallium nitride MOSFETs have zero recovery losses during turn-off, and the discharge time and turn-off time of gallium nitride MOSFETs are shorter than those of traditional silicon carbide MOSFETs, thus enabling high switching frequencies, no freewheeling diodes, and smaller volumes, making it possible to implement a low-cost and high-efficiency PFC circuit.

[0060] According to an embodiment of the present invention, the temperature detector 120 is arranged at the air inlet of the indoor unit of the refrigeration device. Thus, the indoor environmental temperature can be detected in real time to obtain temperature information.

[0061] According to an embodiment of the present invention, when the conversion bridge 110 operates in a discontinuous conduction mode, the first switching transistor Q1 and the second switching transistor Q2 are respectively turned on or off at intervals, and the first switching transistor Q1 and the second switching transistor Q2 are alternately turned on or off.

[0062] Specifically, when the conversion bridge 110 operates in the discontinuous conduction mode, during the positive half-cycle of the AC power supply AC, the first switching tube Q1 of the controller 130 conducts and the second switching tube Q2 turns off. The AC power supply AC, the inductor L1, the first switching tube Q1, the capacitor C1, the second freewheeling device D2, and the AC power supply AC form a loop, and the current flow direction is as shown by the dashed line in Figure 2 Similarly, during the negative half-cycle of the AC power supply AC, the controller 130 controls the first switching tube Q1 to turn off and the second switching tube Q2 to conduct. The AC power supply AC, the first freewheeling device D1, the capacitor C1, the second switching tube Q2, the inductor L1, and the AC power supply AC form a loop, and the current flow direction is as shown by the dashed line in Figure 3

[0063] According to an embodiment of the present invention, when the conversion bridge 110 operates in the continuous conduction mode, the first switching tube Q1 and the second switching tube Q2 conduct or turn off continuously respectively, and the first switching tube Q1 and the second switching tube Q2 conduct or turn off alternately.

[0064] Specifically, when the conversion bridge 110 operates in the continuous conduction mode, during the positive half-cycle of the AC power supply AC, the controller 130 first controls the second switching tube Q2 to conduct and the first switching tube Q1 to turn off. At this time, the AC power supply AC, the inductor L1, the second switching tube Q2, the second freewheeling device D2, and the AC power supply AC form a loop, and the current flow direction is as shown by the dashed line in Figure 4 The AC power supply AC charges the inductor L1; then it controls the first switching tube Q1 to conduct and the second switching tube Q2 to turn off. The AC power supply AC, the inductor L1, the first switching tube Q1, the capacitor C1, the second freewheeling device D2, and the AC power supply AC form a loop, and the current flow direction is as shown by the dashed line in Figure 5 The electric quantity stored in the inductor L1 is released and superimposed on the voltage of the AC power supply AC to boost-charge the capacitor C1, so as to boost the voltage and improve the power factor. In this cycle, the controller 130 controls the first switching tube Q1 and the second switching tube Q2 to conduct or turn off alternately based on the set frequency.

[0065] ​During the negative half - cycle of the AC power supply AC, the controller 130 first controls the first switching transistor Q1 to turn on and the second switching transistor Q2 to turn off. Although not shown in the figure, at this time, a loop is formed by the AC power supply AC, the first free - wheeling device D1, the first switching transistor Q1, the inductor L1, and the AC power supply AC, and the AC power supply AC charges the inductor L1. Then, it controls the second switching transistor Q2 to turn on and the first switching transistor Q1 to turn off. Although not shown in the figure, a loop is formed by the AC power supply AC, the first free - wheeling device D1, the capacitor C1, the second switching transistor Q2, the inductor L1, and the AC power supply AC. The electric charge stored in the inductor L1 is released and superimposed on the voltage of the AC power supply AC to boost - charge the capacitor C1, thereby achieving voltage boost and improving the power factor. In this cycle, the controller 130 controls the first switching transistor Q1 and the second switching transistor Q2 in the first bridge arm 111 to alternately turn on or off based on the set frequency.

[0066] According to an embodiment of the present invention, the controller 130 includes a Kalman filter, and processes the temperature information within a target time period through the Kalman filter to obtain the temperature slope.

[0067] Specifically, the temperature detector 120 detects the indoor ambient temperature in real - time to obtain temperature information and transmits it to the controller 130. The Kalman filter processes the temperature information within the target time period in real - time, removes the noise in the temperature data, calculates the temperature slope based on the temperature information, and can predict the temperature slope at the next moment according to the temperature slope at the previous moment and the temperature slope at the current moment. The controller 130 controls the working mode of the conversion bridge 110 based on the predicted temperature slope at a certain moment, which can further improve the comfort of the indoor environment and can improve the efficiency.

[0068] According to another embodiment of the present invention, the controller 130 processes the temperature information within a target time period based on the recursive line approximation method to obtain the temperature slope.

[0069] Specifically, after obtaining the temperature information, the controller 130 can process the discrete sampled temperature data within the target time range according to the recursive line approximation method to obtain the recursive line approximation line type of the temperature information. The line type can be a linear function, and the slope of the function is the temperature slope.

[0070] In an embodiment of the present invention, the power conversion device 100 further includes an EMI filter, and the EMI filter can be disposed between the AC power supply AC and the inductor L1. The EMI filter can filter out the high - frequency and high - order harmonics in the alternating current output by the AC power supply AC, prevent the high - frequency and high - order harmonics from affecting the power conversion device 100, and improve the stability of the power conversion device 100.

[0071] In summary, for the power conversion device according to the embodiment of the present invention, the output voltage of the conversion bridge is regulated by a capacitor to provide a DC power supply. The indoor ambient temperature is detected by a temperature detector to obtain temperature information. The controller determines the temperature slope according to the temperature information and controls the switching tube among multiple components according to the temperature slope to switch the operating mode of the conversion bridge between the discontinuous conduction mode and the continuous conduction mode. Thus, the device can switch the operating mode of the conversion bridge according to the temperature slope of the indoor environment, accurately track the room temperature, improve the comfort of the indoor environment, and improve the efficiency.

[0072] Corresponding to the above embodiment, the present invention also proposes a refrigeration device.

[0073] Figure 6 It is a block diagram of the refrigeration device according to the embodiment of the present invention.

[0074] As Figure 6 shown, the refrigeration device 200 according to the embodiment of the present invention includes: a compressor 210; the above-mentioned power conversion device 100, which is adapted to convert the input AC power supply into a DC power supply to supply power to the compressor 210.

[0075] For the refrigeration device according to the embodiment of the present invention, through the above-mentioned power conversion device, the operating mode of the conversion bridge can be switched according to the temperature slope of the indoor environment, accurately track the room temperature, improve the comfort of the indoor environment, and improve the efficiency.

[0076] Corresponding to the above embodiment, the present invention also proposes a control method for the PFC circuit in a refrigeration device.

[0077] Figure 7 It is a flowchart of the control method for the PFC circuit in the refrigeration device according to the embodiment of the present invention.

[0078] In an embodiment of the present invention, as Figure 8As shown in the figure, the PFC circuit may include a conversion bridge 110, an inductor L1, and a capacitor C1. Among them, the conversion bridge 110 includes a plurality of components, which are connected in a bridge shape and are constructed with an input end and an output end. The inductor L1 is connected between the AC power supply AC and the input end. The inductor L1 can store the power supplied from the AC power supply AC and improve the voltage boost and power factor by releasing the stored energy. The capacitor C1 is connected to the output end and is suitable for stabilizing the output voltage of the conversion bridge to provide a DC power supply. The plurality of components include a first switching tube Q1, a second switching tube Q2, a first freewheeling device D1, and a second freewheeling device D2. The first switching tube Q1 and the second switching tube Q2 form a first bridge arm 111, and the first freewheeling device D1 and the second freewheeling device D2 form a second bridge arm 112. The midpoints of the first bridge arm 111 and the second bridge arm 112 are used as the input end, and the two ends of the first bridge arm 111 or the second bridge arm 112 are used as the output end. The midpoint of the first bridge arm 111 is connected to the AC power supply AC through the inductor L1. Among them, the first switching tube Q1 and the second switching tube Q2 are gallium nitride MOSFETs respectively, and the first freewheeling device D1 and the second freewheeling device D2 are diodes respectively.

[0079] As Figure 7 shown, the control method of the PFC circuit in the refrigeration device according to the embodiment of the present invention may include the following steps:

[0080] S1, Detect the indoor ambient temperature to obtain temperature information.

[0081] S2, Determine the temperature slope according to the temperature information, and control the switching tube in the PFC circuit according to the temperature slope to switch the working mode of the PFC circuit, where the working mode of the PFC circuit includes a discontinuous conduction mode and a continuous conduction mode.

[0082] Specifically, the electric energy provided by the AC power supply is input into the conversion bridge through an inductor for conversion. The capacitor can smooth the voltage output from the conversion bridge into a DC voltage and output it to the compressor of the refrigeration device to supply power to the compressor. After the compressor operates, the refrigeration device can heat or cool the indoor environment according to user needs. During the operation of the compressor, the temperature detector detects the indoor environment temperature in real time, obtains temperature information, and transmits it to the controller. The controller can calculate the temperature slope from the discrete sampled temperature data within an arbitrary time range and can control the switching tube in multiple components according to the temperature slope to switch the working mode of the conversion bridge between the discontinuous conduction mode and the continuous conduction mode. Taking the refrigeration of the indoor environment by the refrigeration device as an example, at the initial stage of refrigeration, the temperature of the indoor environment decreases from high to low and the change speed is relatively fast. At this time, the corresponding temperature slope is large, indicating that the refrigeration load is high at this time. The controller can drive the compressor in the continuous conduction mode by the PFC circuit. As refrigeration progresses, the temperature of the indoor environment gradually approaches the set temperature. At this time, the corresponding temperature slope is small, indicating that the refrigeration load is low at this time. The controller can drive the compressor in the discontinuous conduction mode by the PFC circuit. Thus, by switching the operation mode of the compressor motor, the efficiency of the compressor and the circuit can be improved, and the room temperature can be accurately tracked, improving the comfort of the indoor environment and improving the efficiency.

[0083] According to an embodiment of the present invention, determining the temperature slope according to the temperature information includes: processing the temperature information within a target time period by using a Kalman filter to obtain the temperature slope.

[0084] Specifically, the indoor environment temperature can be detected in real time by a temperature detector to obtain temperature information and transmitted to the controller. The Kalman filter processes the temperature information within the target time period in real time, removes the noise in the temperature data, then calculates the temperature slope according to the temperature information, and can predict the temperature slope at the next moment according to the temperature slope at the previous moment and the temperature slope at the current moment. The controller controls the working mode of the conversion bridge based on the predicted temperature slope at a certain moment, which can further improve the comfort of the indoor environment and improve the efficiency.

[0085] According to another embodiment of the present invention, determining the temperature slope according to the temperature information includes: processing the temperature information within a target time period based on the recursive line approximation method to obtain the temperature slope.

[0086] Specifically, after the controller obtains the temperature information, it can process the discrete sampled temperature data within the target time range according to the recursive line approximation method to obtain the recursive line approximation line type of the temperature information. The line type can be a linear function, and the slope of the function is the temperature slope.

[0087] According to an embodiment of the present invention, controlling a switching transistor in a PFC circuit according to a temperature slope includes: when the temperature slope is greater than or equal to a first set threshold, controlling a first switching transistor and a second switching transistor to be continuously turned on or off respectively, and the first switching transistor and the second switching transistor are alternately turned on or off, so that the PFC circuit operates in a continuous conduction mode; when the temperature slope is less than the first set threshold, controlling the first switching transistor and the second switching transistor to be turned on or off at intervals respectively, and the first switching transistor and the second switching transistor are alternately turned on or off, so that the PFC circuit operates in a discontinuous conduction mode. Wherein, the first set threshold can be calibrated according to actual conditions.

[0088] Specifically, when the temperature slope is greater than or equal to the first set threshold, at this time, the room temperature differs greatly from the set temperature, and the compressor is in a high-load working state. The controller controls the PFC circuit to operate in a continuous conduction mode. In the positive half-cycle of the AC power supply AC, the controller 130 first controls the second switching transistor Q2 to be turned on and the first switching transistor Q1 to be turned off. At this time, the AC power supply AC, the inductor L1, the second switching transistor Q2, the second freewheeling device D2, and the AC power supply AC form a loop, and the current flow is as shown by the dotted line in Figure 4 , and the AC power supply AC charges the inductor L1; then controls the first switching transistor Q1 to be turned on and the second switching transistor Q2 to be turned off. The AC power supply AC, the inductor L1, the first switching transistor Q1, the capacitor C1, the second freewheeling device D2, and the AC power supply AC form a loop, and the current flow is as shown by the dotted line in Figure 5 . The electric quantity stored in the inductor L1 is released and superimposed on the voltage of the AC power supply AC to boost-charge the capacitor C1, so as to boost the voltage and improve the power factor. In this cycle, the controller 130 controls the first switching transistor Q1 and the second switching transistor Q2 to be alternately turned on or off based on the set frequency. In the negative half-cycle of the AC power supply AC, the controller 130 first controls the first switching transistor Q1 to be turned on and the second switching transistor Q2 to be turned off. Although not shown, at this time, the AC power supply AC, the first freewheeling device D1, the first switching transistor Q1, the inductor L1, and the AC power supply AC form a loop, and the AC power supply AC charges the inductor L1; then controls the second switching transistor Q2 to be turned on and the first switching transistor Q1 to be turned off. Although not shown, the AC power supply AC, the first freewheeling device D1, the capacitor C1, the second switching transistor Q2, the inductor L1, and the AC power supply AC form a loop, and the electric quantity stored in the inductor L1 is released and superimposed on the voltage of the AC power supply AC to boost-charge the capacitor C1, so as to boost the voltage and improve the power factor. In this cycle, the controller 130 controls the first switching transistor Q1 and the second switching transistor Q2 in the first bridge arm 111 to be alternately turned on or off based on the set frequency.

[0089] When the temperature slope is less than the first set threshold, the difference between the room temperature and the set temperature is small at this time, and the compressor is in a low-load state. The controller controls the PFC circuit to operate in a discontinuous conduction mode. During the positive half-cycle of the AC power supply AC, the first switch tube Q1 of the controller 130 is turned on and the second switch tube Q2 is turned off. The AC power supply AC, the inductor L1, the first switch tube Q1, the capacitor C1, the second freewheeling device D2, and the AC power supply AC form a loop, and the current flow is as shown in Figure 2 the dotted line in. Similarly, during the negative half-cycle of the AC power supply AC, the controller 130 controls the first switch tube Q1 to be turned off and the second switch tube Q2 to be turned on. The AC power supply AC, the first freewheeling device D1, the capacitor C1, the second switch tube Q2, the inductor L1, and the AC power supply AC form a loop, and the current flow is as shown in Figure 3 the dotted line in.

[0090] According to an embodiment of the present invention, the discontinuous conduction mode includes a first Burst control mode and a second Burst control mode. Among them, when the temperature slope is less than the first set threshold, the method further includes: if the temperature slope is greater than or equal to the second set threshold, controlling the PFC circuit to operate in the first Burst control mode, where the second set threshold is less than the first set threshold; if the temperature slope is less than the second set threshold, controlling the PFC circuit to operate in the second Burst control mode, where the duty cycle corresponding to the second Burst control mode is less than the duty cycle corresponding to the first Burst control mode. Among them, the second set threshold can be calibrated according to the actual situation.

[0091] Specifically, for the convenience of control, the load range of the compressor can be divided according to the magnitude of the temperature slope. For example, when the temperature slope is greater than or equal to the first set threshold, the load range of the compressor is the high-load range; when the temperature slope is greater than or equal to the second set threshold and less than the first set threshold, the load range of the compressor is the medium-load range, and the medium-load range can also be used as the rated medium load; when the temperature slope is less than the second set threshold, the load range of the compressor is the low-load range.

[0092] Specifically, when the temperature slope is less than the first set threshold and greater than or equal to the second set threshold, the controller controls the PFC circuit to operate in the first Burst control mode. For example, the controller can control the first switching transistor and the second switching transistor in the PFC circuit to conduct or turn off at intervals with a duty cycle of 70%, and the first switching transistor and the second switching transistor conduct or turn off alternately; when the temperature slope is less than the second set threshold, the controller controls the PFC circuit to operate in the second Burst control mode. For example, the controller can control the first switching transistor and the second switching transistor in the PFC circuit to conduct or turn off at intervals with a duty cycle of 50% or less, and the first switching transistor and the second switching transistor conduct or turn off alternately.

[0093] In summary, according to the control method of the PFC circuit in the refrigeration device of the embodiment of the present invention, the indoor ambient temperature is first detected to obtain temperature information, then the temperature slope is determined according to the temperature information, and the switching transistors in the PFC circuit are controlled according to the temperature slope to switch the working mode of the PFC circuit between the discontinuous conduction mode and the continuous conduction mode. Thus, this method can switch the working mode of the PFC circuit according to the temperature slope of the indoor environment, can accurately track the room temperature, improve the comfort of the indoor environment, and can improve the efficiency.

[0094] Corresponding to the above embodiment, the present invention also proposes a computer-readable storage medium.

[0095] The computer-readable storage medium of the embodiment of the present invention stores a control program for the PFC circuit in the refrigeration device, and when the program is executed by a processor, the control method of the PFC circuit in the refrigeration device as described above is implemented.

[0096] According to the computer-readable storage medium of the embodiment of the present invention, through the above control method of the PFC circuit in the refrigeration device, the working mode of the PFC circuit can be switched according to the temperature slope of the indoor environment, the room temperature can be accurately tracked, the comfort of the indoor environment can be improved, and the efficiency can be improved.

[0097] Corresponding to the above embodiment, the present invention also proposes a controller.

[0098] Figure 9 It is a block diagram of the controller according to the embodiment of the present invention.

[0099] As Figure 9 shown, the controller 300 of the embodiment of the present invention includes: a memory 310, a processor 320, and a control program for the PFC circuit in the refrigeration device stored on the memory 310 and operable on the processor 320. When the processor 320 executes the program, the control method of the PFC circuit in the refrigeration device as described above is implemented.

[0100] According to the controller of the embodiment of the present invention, through the control method of the PFC circuit in the above refrigeration device, the working mode of the PFC circuit can be switched according to the temperature slope of the indoor environment, accurately tracking the room temperature, improving the comfort of the indoor environment, and improving the efficiency.

[0101] Corresponding to the above embodiment, the present invention also proposes another refrigeration device.

[0102] Figure 10 It is a block diagram of the refrigeration device according to the embodiment of the present invention.

[0103] As Figure 10 shown, the refrigeration device 400 according to the embodiment of the present invention includes: a compressor 410; a PFC circuit 420 adapted to provide a DC power supply to the compressor 410, and the working modes of the PFC circuit 420 include a discontinuous conduction mode and a continuous conduction mode; a temperature detector 430 adapted to detect the indoor environment temperature to obtain temperature information; a controller 440 configured to determine a temperature slope according to the temperature information and control a switching tube in the PFC circuit 420 according to the temperature slope to switch the working mode of the PFC circuit 420.

[0104] According to an embodiment of the present invention, the controller 440 determines the temperature slope according to the temperature information, specifically, using a Kalman filter to process the temperature information within a target time period to obtain the temperature slope.

[0105] According to another embodiment of the present invention, the controller 440 determines the temperature slope according to the temperature information, specifically, processing the temperature information within a target time period based on the recursive line approximation method to obtain the temperature slope.

[0106] According to an embodiment of the present invention, the controller 440 controls the switching tube in the PFC circuit 420 according to the temperature slope. Specifically, when the temperature slope is greater than or equal to a first set threshold, controlling the first switching tube and the second switching tube to be continuously turned on or off respectively, and the first switching tube and the second switching tube to be alternately turned on or off, so that the PFC circuit 420 operates in a continuous conduction mode; when the temperature slope is less than the first set threshold, controlling the first switching tube and the second switching tube to be turned on or off at intervals respectively, and the first switching tube and the second switching tube to be alternately turned on or off, so that the PFC circuit 420 operates in a discontinuous conduction mode.

[0107] According to an embodiment of the present invention, the discontinuous conduction mode includes a first Burst control mode and a second Burst control mode. Wherein, when the temperature slope is less than a first set threshold, the controller 440 is further configured to, if the temperature slope is greater than or equal to a second set threshold, control the PFC circuit 420 to operate in the first Burst control mode, wherein the second set threshold is less than the first set threshold; if the temperature slope is less than the second set threshold, control the PFC circuit 420 to operate in the second Burst control mode, wherein the duty cycle corresponding to the second Burst control mode is less than the duty cycle corresponding to the first Burst control mode.

[0108] It should be noted that for the details not disclosed in the refrigeration device of the embodiment of the present invention, please refer to the details disclosed in the control method of the PFC circuit in the refrigeration device of the embodiment of the present invention, and will not be elaborated here specifically.

[0109] For the refrigeration device according to the embodiment of the present invention, a DC power supply is provided to the compressor through the PFC circuit, the indoor ambient temperature is detected by the temperature detector to obtain temperature information, the controller determines the temperature slope according to the temperature information, and controls the switching tube in the PFC circuit according to the temperature slope to switch the operating mode of the PFC circuit between the discontinuous conduction mode and the continuous conduction mode. Thus, the device can switch the operating mode of the PFC circuit according to the temperature slope of the indoor environment, can accurately track the room temperature, improve the comfort of the indoor environment, and can improve the efficiency.

[0110] It should be noted that the logic and / or steps represented in the flowchart or described otherwise herein, for example, can be considered as a definite sequence list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by an instruction execution system, apparatus, or device (such as a computer-based system, a system including a processor, or other systems that can fetch and execute instructions from the instruction execution system, apparatus, or device), or in combination with these instruction execution systems, apparatuses, or devices. For the purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transport a program for use by or in combination with an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of the computer-readable medium include the following: an electrical connection part with one or more wirings (electronic device), a portable computer diskette (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM). Additionally, the computer-readable medium can even be paper or other suitable media on which the program can be printed, because the program can be obtained electronically, for example, by optically scanning the paper or other media, followed by editing, interpretation, or other suitable processing as necessary, and then stored in a computer memory.

[0111] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware, or a combination thereof. In the above-described embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, any one or a combination of the following techniques well known in the art can be used: discrete logic circuits with logic gate circuits for implementing logical functions on data signals, application specific integrated circuits with suitable combinational logic gate circuits, programmable gate arrays (PGAs), field programmable gate arrays (FPGAs), etc.

[0112] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0113] In addition, 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 quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0114] In the present invention, unless otherwise clearly specified and limited, the terms "mounted", "connected", "coupled", "fixed", etc. shall be construed in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0115] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A power conversion device, characterized in that, it is adapted to convert an input AC power supply into a DC power supply to supply power to the compressor of a refrigeration device, and the power conversion device includes: a conversion bridge, the conversion bridge includes a plurality of components, the plurality of components are connected in a bridge shape, and are configured with an input end and an output end; an inductor, the inductor is connected between the AC power supply and the input end; a capacitor, the capacitor is connected to the output end, and is adapted to perform voltage stabilization processing on the output voltage of the conversion bridge to provide the DC power supply; a temperature detector, adapted to detect the indoor ambient temperature and obtain temperature information; a controller, configured to determine a temperature slope according to the temperature information, and control a switching tube among the plurality of components according to the temperature slope to switch the working mode of the conversion bridge, wherein the working modes of the conversion bridge include a discontinuous conduction mode and a continuous conduction mode.

2. The power conversion device according to claim 1, characterized in that, the plurality of components include a first switching tube, a second switching tube, a first freewheeling device and a second freewheeling device, the first switching tube and the second switching tube form a first bridge arm, the first freewheeling device and the second freewheeling device form a second bridge arm, the midpoints of the first bridge arm and the second bridge arm are used as the input end, the two ends of the first bridge arm or the second bridge arm are used as the output end, and the midpoint of the first bridge arm is connected to the AC power supply through the inductor.

3. The power conversion device according to claim 2, characterized in that, the first switching tube and the second switching tube in the first bridge arm are high-side power devices, and the first freewheeling device and the second freewheeling device in the second bridge arm are low-side freewheeling devices.

4. The power conversion device according to claim 2, characterized in that, the first switching tube and the second switching tube are gallium nitride MOSFETs respectively, and the first freewheeling device and the second freewheeling device are diodes respectively.

5. The power conversion device according to any one of claims 1-4, characterized in that, the temperature detector is arranged at the air inlet of the indoor unit of the refrigeration device.

6. The power conversion device according to any one of claims 2-4, characterized in that, when the conversion bridge operates in the discontinuous conduction mode, the first switching tube and the second switching tube are respectively turned on or off at intervals, and the first switching tube and the second switching tube are alternately turned on or off.

7. The power conversion device according to any one of claims 2-4, characterized in that, when the conversion bridge operates in the continuous conduction mode, the first switching tube and the second switching tube are respectively continuously turned on or off, and the first switching tube and the second switching tube are alternately turned on or off.

8. The power conversion device according to any one of claims 1-4, characterized in that, the controller includes a Kalman filter, and processes the temperature information within a target time period through the Kalman filter to obtain the temperature slope.

9. The power conversion device according to any one of claims 1-4, characterized in that, the controller processes the temperature information within a target time period based on the recursive line approximation method to obtain the temperature slope.

10. A refrigeration device, characterized in that, comprising: a compressor; the power conversion device according to any one of claims 1-9, adapted to convert an input AC power supply into a DC power supply to supply power to the compressor.

11. A control method for a PFC circuit in a refrigeration device, characterized in that, the method comprises: detecting the indoor ambient temperature to obtain temperature information; determining a temperature slope according to the temperature information, and controlling a switching tube in the PFC circuit according to the temperature slope to switch the working mode of the PFC circuit, wherein the working modes of the PFC circuit include a discontinuous conduction mode and a continuous conduction mode.

12. The method according to claim 11, characterized in that, determining a temperature slope according to the temperature information, comprising: processing the temperature information within a target time period by using a Kalman filter to obtain the temperature slope.

13. The method according to claim 11, characterized in that, determining a temperature slope according to the temperature information, comprising: processing the temperature information within a target time period based on the recursive line approximation method to obtain the temperature slope.

14. The method according to any one of claims 11-13, characterized in that, controlling the switching tube in the PFC circuit according to the temperature slope, comprising: when the temperature slope is greater than or equal to a first set threshold, controlling a first switching tube and a second switching tube to be continuously turned on or off respectively, and the first switching tube and the second switching tube are alternately turned on or off, so that the PFC circuit operates in the continuous conduction mode; when the temperature slope is less than the first set threshold, controlling the first switching tube and the second switching tube to be turned on or off at intervals respectively, and the first switching tube and the second switching tube are alternately turned on or off, so that the PFC circuit operates in the discontinuous conduction mode.

15. The method according to claim 14, characterized in that, the discontinuous conduction mode includes a first Burst control mode and a second Burst control mode, wherein, when the temperature slope is less than the first set threshold, the method further comprises: if the temperature slope is greater than or equal to a second set threshold, controlling the PFC circuit to operate in the first Burst control mode, wherein the second set threshold is less than the first set threshold; if the temperature slope is less than the second set threshold, controlling the PFC circuit to operate in the second Burst control mode, wherein the duty ratio corresponding to the second Burst control mode is less than the duty ratio corresponding to the first Burst control mode.

16. A computer-readable storage medium, characterized in that, It stores a control program for the PFC circuit in a refrigeration device, and when the program is executed by a processor, it implements the control method for the PFC circuit in the refrigeration device according to any one of claims 11-15.

17. A controller, characterized in that it includes: a memory, a processor, and a control program for the PFC circuit in the refrigeration device stored on the memory and operable on the processor, and when the processor executes the program, it implements the control method for the PFC circuit in the refrigeration device according to any one of claims 11-15.

18. A refrigeration device, characterized in that it includes: a compressor; a PFC circuit adapted to provide a DC power supply to the compressor, and the operating modes of the PFC circuit include a discontinuous conduction mode and a continuous conduction mode; a temperature detector adapted to detect the indoor ambient temperature to obtain temperature information; a controller configured to determine a temperature slope according to the temperature information and control a switching tube in the PFC circuit according to the temperature slope to switch the operating mode of the PFC circuit.

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