Power conversion device, refrigeration device and control method for PFC circuit of refrigeration device, and controller

Abstract

A power conversion device, a refrigeration device and a control method for a PFC circuit of the refrigeration device, and a controller. The power conversion device is adapted to convert an input alternating-current power supply into a direct-current power supply, so as to supply power for a compressor of the refrigeration device. The power conversion device comprises: a conversion bridge, comprising a plurality of components and provided with an input end and an output end; an inductor, connected between the alternating-current power supply and the input end; a capacitor, connected to the output end and adapted to carry out voltage stabilization treatment on the output voltage of the conversion bridge so as to provide the direct-current power supply; and a controller, configured to determine a temperature slope on the basis of temperature information and control switching transistors in the plurality of components on the basis of the temperature slope, so as to switch the working mode of the conversion bridge, wherein the working mode of the conversion bridge comprises a discontinuous turn-on mode and a continuous turn-on mode.

Description

Power conversion device, refrigeration equipment, and control method and controller for PFC circuit thereof

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application filed with the Patent Office of China on November 28, 2023, with application number CN202311612697.3 and application name “Power conversion device, refrigeration equipment and control method and controller of its PFC circuit”, as well as priority to the Chinese patent application filed with the Patent Office of China on November 28, 2023, with application number CN202323234221.9 and application name “Power conversion device and refrigeration equipment”, all of which are incorporated herein by reference. Technical Field

[0003] The present disclosure 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

[0004] In related technologies, switching the compressor's operating mode during the operation of refrigeration equipment such as air conditioners is typically controlled using a shunt resistor or current sensor. This uses the compressor's current as a threshold to determine whether to switch the compressor's operating mode. However, this switching control relies solely on the compressor's current, which means the compressor's operating mode may not fully adapt to the indoor environment, resulting in poor indoor comfort.

[0005] Application Contents

[0006] According to various embodiments of the present disclosure, the present disclosure proposes 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 efficiency.

[0007] According to various embodiments of the present disclosure, an embodiment of the first aspect of the present disclosure proposes a power conversion device, which is suitable for converting an input AC power supply into a DC power supply to power a compressor of a refrigeration device. The power conversion device includes: a conversion bridge, which includes multiple components, and the multiple components are connected in a bridge shape and are constructed with an input end and an output end; an inductor, which is connected between the AC power supply and the input end; a capacitor, which is connected to the output end and is suitable for stabilizing the output voltage of the conversion bridge to provide the DC power supply; a temperature detector, which is suitable for detecting the indoor ambient temperature and obtaining temperature information; a controller, which is configured to determine a temperature slope according to the temperature information, and control the switching tubes in the multiple components according to the temperature slope to switch the working mode of the conversion bridge, wherein the working mode of the conversion bridge includes a discontinuous conduction mode and a continuous conduction mode.

[0008] According to the power conversion device of the disclosed embodiment, a capacitor is used to stabilize the output voltage of the converter bridge to provide a DC power supply. A temperature detector is used to detect the indoor ambient temperature to obtain temperature information. A controller determines a temperature slope based on the temperature information and controls the switches in multiple components based on the temperature slope to switch the operating mode of the converter bridge between discontinuous conduction mode and continuous conduction mode. Thus, the device can switch the operating mode of the converter bridge based on the temperature slope of the indoor environment, accurately tracking the room temperature, improving indoor comfort, and enhancing efficiency.

[0009] In addition, the power conversion device according to the above embodiment of the present invention may also have the following additional technical features:

[0010] According to one embodiment of the present disclosure, the multiple 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 constitute a first bridge arm, the first freewheeling device and the second freewheeling device constitute a second bridge arm, the midpoint of the first bridge arm and the midpoint of the second bridge arm serve as the input end, the two ends of the first bridge arm or the second bridge arm serve as the output end, and the midpoint of the first bridge arm is connected to the AC power supply through the inductor.

[0011] According to one embodiment of the present disclosure, 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.

[0012] According to one embodiment of the present disclosure, the first switching tube and the second switching tube are respectively gallium nitride MOSFETs, and the first freewheeling device and the second freewheeling device are respectively diodes.

[0013] According to one embodiment of the present disclosure, the temperature detector is arranged at an air inlet of an indoor unit of the refrigeration equipment.

[0014] According to an embodiment of the present disclosure, 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 turned on or off alternately.

[0015] According to one embodiment of the present disclosure, when the conversion bridge operates in the continuous conduction mode, the first switching tube and the second switching tube are respectively turned on or off continuously, and the first switching tube and the second switching tube are turned on or off alternately.

[0016] According to one embodiment of the present disclosure, the controller includes a Kalman filter, and the temperature information within a target time period is processed by the Kalman filter to obtain the temperature slope.

[0017] According to another embodiment of the present disclosure, the controller processes the temperature information within the target time period based on a recursive line approximation method to obtain the temperature slope.

[0018] According to various embodiments of the present disclosure, a second aspect of the present disclosure provides a refrigeration device, including: a compressor; and the above-mentioned power conversion device, suitable for converting input AC power into DC power to power the compressor.

[0019] According to the refrigeration equipment of the embodiment of the present disclosure, through the above-mentioned power conversion device, the working mode of the conversion bridge can be switched according to the temperature slope of the indoor environment, and the room temperature can be accurately tracked, the comfort of the indoor environment can be improved, and the efficiency can be improved.

[0020] According to various embodiments of the present disclosure, a third aspect of the present disclosure provides a method for controlling a PFC circuit in a refrigeration device. The method includes: detecting an indoor ambient temperature to obtain temperature information; determining a temperature slope based on the temperature information; and controlling a switch in the PFC circuit based on the temperature slope to switch an operating mode of the PFC circuit. The operating modes of the PFC circuit include a discontinuous conduction mode and a continuous conduction mode.

[0021] According to the disclosed embodiment of the PFC circuit control method for refrigeration equipment, the indoor ambient temperature is first detected to obtain temperature information. A temperature slope is then determined based on the temperature information. Based on the temperature slope, the switching transistor in the PFC circuit is controlled to switch the PFC circuit's operating mode between discontinuous conduction mode and continuous conduction mode. This method can thus switch the PFC circuit's operating mode based on the indoor ambient temperature slope, accurately tracking the indoor room temperature, improving indoor comfort, and enhancing efficiency.

[0022] In addition, the control method of the PFC circuit in the refrigeration equipment according to the above embodiment of the present disclosure may also have the following additional technical features:

[0023] According to an embodiment of the present disclosure, determining the temperature slope according to the temperature information includes: processing the temperature information within a target time period using a Kalman filter to obtain the temperature slope.

[0024] According to another embodiment of the present disclosure, determining a temperature slope according to the temperature information includes: processing the temperature information within a target time period based on a recursive line approximation method to obtain the temperature slope.

[0025] According to one embodiment of the present disclosure, controlling the switches in the PFC circuit based on the temperature slope includes: when the temperature slope is greater than or equal to a first set threshold, controlling the first and second switches to be continuously turned on or off, respectively, and the first and second switches to be alternately turned on or off, so that the PFC circuit operates in the continuous conduction mode; and when the temperature slope is less than the first set threshold, controlling the first and second switches to be alternately turned on or off, respectively, and the first and second switches to be alternately turned on or off, so that the PFC circuit operates in the discontinuous conduction mode.

[0026] According to one embodiment of the present disclosure, the discontinuous conduction mode includes a first burst control mode and a second burst control mode. When the temperature slope is less than a 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, wherein the second set threshold is less than the first set threshold; and if the temperature slope is less than the second set threshold, controlling the PFC circuit to operate in the second burst control mode, wherein a duty cycle corresponding to the second burst control mode is less than a duty cycle corresponding to the first burst control mode.

[0027] According to various embodiments of the present disclosure, a fourth aspect of the present disclosure provides a computer-readable storage medium storing a control program for a PFC circuit in a refrigeration device. When the program is executed by a processor, the control method for a PFC circuit in a refrigeration device is implemented.

[0028] According to the computer-readable storage medium of the embodiment of the present disclosure, through the above-mentioned control method of the PFC circuit in the refrigeration equipment, the operating 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.

[0029] According to various embodiments of the present disclosure, a fifth aspect of the present disclosure provides a controller, comprising: a memory, a processor, and a control program for a PFC circuit in a refrigeration device stored in the memory and executable on the processor. When the processor executes the program, the above-mentioned method for controlling a PFC circuit in the refrigeration device is implemented.

[0030] According to the controller of the embodiment of the present disclosure, through the above-mentioned control method of the PFC circuit in the refrigeration equipment, the operating 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] According to various embodiments of the present disclosure, a sixth aspect of the present disclosure provides a refrigeration device, comprising: a compressor; a PFC circuit adapted to provide a DC power supply to the compressor, wherein the operating modes of the PFC circuit include a discontinuous conduction mode and a continuous conduction mode; a temperature detector adapted to detect an indoor ambient temperature and obtain temperature information; and a controller configured to determine a temperature slope based on the temperature information, and control a switch in the PFC circuit based on the temperature slope to switch the operating mode of the PFC circuit.

[0032] According to the refrigeration equipment of the disclosed embodiment, a PFC circuit provides DC power to the compressor. A temperature detector detects the indoor ambient temperature to obtain temperature information. A controller determines a temperature slope based on the temperature information and controls the switching transistor in the PFC circuit based on the temperature slope to switch the PFC circuit's operating mode between discontinuous conduction mode and continuous conduction mode. Thus, the device can switch the PFC circuit's operating mode based on the indoor ambient temperature slope, accurately tracking the indoor room temperature, improving indoor comfort, and increasing efficiency.

[0033] Additional aspects and advantages of the present disclosure will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] FIG1 is a block diagram of a power conversion device according to an embodiment of the present disclosure;

[0035] FIG2 is a schematic diagram of the current flow direction of the positive half cycle of the AC power supply in the discontinuous conduction mode of the converter bridge according to one embodiment of the present disclosure;

[0036] 3 is a schematic diagram of the current flow direction of the negative half cycle of the AC power supply in the discontinuous conduction mode of the converter bridge according to one embodiment of the present disclosure;

[0037] 4 is a schematic diagram of the current flow direction of the positive half cycle of the AC power supply in a converter bridge in a continuous conduction mode according to one embodiment of the present disclosure;

[0038] 5 is a schematic diagram of the current flow direction of the positive half cycle of the AC power supply in a converter bridge in a continuous conduction mode according to one embodiment of the present disclosure;

[0039] FIG6 is a block diagram of a refrigeration device according to an embodiment of the present disclosure;

[0040] FIG7 is a flow chart of a method for controlling a PFC circuit in a refrigeration device according to an embodiment of the present disclosure;

[0041] FIG8 is a hardware topology diagram of a PFC circuit in a refrigeration device according to an embodiment of the present disclosure;

[0042] FIG9 is a block diagram of a controller according to an embodiment of the present disclosure;

[0043] FIG10 is a block diagram of a refrigeration device according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0044] The following describes in detail embodiments of the present disclosure, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present disclosure, and should not be construed as limiting the present disclosure.

[0045] The following describes a power conversion device, a refrigeration device, a control method for a PFC circuit in a refrigeration device, a computer-readable storage medium, and a controller proposed in embodiments of the present disclosure with reference to the accompanying drawings.

[0046] FIG1 is a block diagram of a power conversion device according to an embodiment of the present disclosure.

[0047] As shown in Figure 1, the power conversion device 100 of the embodiment of the present disclosure is suitable for converting the input AC power supply into a DC power supply to power the compressor of the refrigeration equipment. 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.

[0048] The conversion bridge 110 includes multiple components connected in a bridge shape and having an input terminal and an output terminal. It should be noted that the circuit in which the multiple components are connected in a bridge shape can be a half-bridge circuit, an H-bridge circuit, a three-phase bridge circuit, etc., and is not specifically limited to this.

[0049] The inductor L1 is connected between the AC power source AC and the input terminal. The inductor L1 can store the power supplied from the AC power source AC and release the stored energy to thereby boost the voltage and improve the power factor.

[0050] 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.

[0051] Temperature detector 120 is adapted to detect the indoor ambient temperature and obtain temperature information. Controller 130 is configured to determine a temperature slope based on the temperature information and, based on the temperature slope, control switches in multiple components to switch the operating mode of converter bridge 110, which includes a discontinuous conduction mode and a continuous conduction mode.

[0052] Specifically, the AC power source (AC) is input to the converter bridge 110 through inductor L1 for conversion. Capacitor C1 smoothes the voltage output from the converter bridge 110 into a DC voltage, which is then output to the compressor of the refrigeration equipment to power the compressor. Once the compressor is running, the refrigeration equipment can heat or cool the indoor environment according to user needs. During compressor operation, the temperature detector 120 detects the indoor ambient temperature in real time, obtains temperature information, and transmits it to the controller 130. Controller 130 calculates a temperature slope from discrete sampled temperature data within any time range and, based on this temperature slope, controls the switches in various components to switch the operating mode of the converter bridge 110 between discontinuous conduction mode and continuous conduction mode. For example, in the initial cooling phase of a refrigeration equipment, the indoor temperature changes rapidly from high to low. The corresponding temperature slope is large, indicating a high cooling load. Therefore, controller 130 can switch the converter bridge 110 to continuous conduction mode to drive the compressor. As cooling progresses, the indoor temperature gradually approaches the set temperature. At this point, the corresponding temperature slope is small, indicating a low cooling load. Controller 130 can then switch bridge 110 to drive the compressor in discontinuous conduction mode. By switching the compressor motor's operating mode, the efficiency of the compressor and circuit can be improved, accurately tracking the room temperature, enhancing indoor comfort and improving efficiency.

[0053] According to one embodiment of the present disclosure, as shown in Figure 1, 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 constitute a first bridge arm 111, and the first freewheeling device D1 and the second freewheeling device D2 constitute a second bridge arm 112. The midpoint of the first bridge arm 111 and the midpoint of the second bridge arm 112 serve as input ends, and the two ends of the first bridge arm 111 or the second bridge arm 112 serve as output ends. The midpoint of the first bridge arm 111 is connected to the AC power supply AC through the inductor L1.

[0054] Specifically, as shown in Figure 1, a first switching transistor Q1 and a second switching transistor Q2 are connected in series to form a first bridge arm 111. The first switching transistor Q1 serves as the upper bridge switching transistor of the first bridge arm 111, and the second switching transistor Q2 serves as the lower bridge switching transistor of the first bridge arm 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 bridge arm 112. One end of an inductor L1 is connected to one end of an AC power source AC, and the other end of the inductor L1 is connected to the connection point between the first switching transistor Q1 and the second freewheeling device 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 bridge arm 112, while the negative electrode is connected to the source of the lower bridge switching transistor in the first bridge arm 111 and the anode of the second freewheeling device D2 in the second bridge arm 112. A controller 130 is connected to the control terminals of the first switching transistor Q1 and the second freewheeling device Q2, respectively.

[0055] Furthermore, according to an embodiment of the present disclosure, the first switch tube Q1 and the second switch tube Q2 in the first bridge arm 111 are high-side power devices, and the first freewheeling device D1 and the second freewheeling device D2 in the second bridge arm 112 are low-side freewheeling devices.

[0056] According to one embodiment of the present disclosure, the first switch tube Q1 and the second switch tube Q2 are respectively gallium nitride MOSFETs, and the first freewheeling device D1 and the second freewheeling device D2 are respectively diodes.

[0057] It's important to understand that traditional SiC MOSFETs have inherent freewheeling diodes and experience recovery losses during turn-off, making it difficult to improve efficiency at switching frequencies (e.g., above 20kHz). Furthermore, SiC MOSFETs are relatively large. In contrast, GaN MOSFETs have zero recovery losses during turn-off, and their discharge and turn-off times are shorter than those of traditional SiC MOSFETs. This allows for high switching frequencies, the absence of a freewheeling diode, and a smaller size, making it possible to implement low-cost, high-efficiency PFC circuits.

[0058] According to an embodiment of the present disclosure, the temperature detector 120 is disposed at the air inlet of the indoor unit of the refrigeration equipment, thereby being able to detect the indoor ambient temperature in real time and obtain temperature information.

[0059] According to an embodiment of the present disclosure, when the conversion bridge 110 operates in the discontinuous conduction mode, the first switch tube Q1 and the second switch tube Q2 are turned on or off at intervals, and the first switch tube Q1 and the second switch tube Q2 are turned on or off alternately.

[0060] Specifically, when the converter bridge 110 operates in discontinuous conduction mode, during the positive half-cycle of the AC power source AC, the controller 130 turns on the first switch Q1 and turns off the second switch Q2. The AC power source AC, inductor L1, first switch Q1, capacitor C1, second freewheeling device D2, and AC power source AC form a loop, and the current flows as shown by the dotted line in FIG2 . Similarly, during the negative half-cycle of the AC power source AC, the controller 130 controls the first switch Q1 to turn off and the second switch Q2 to turn on. The AC power source AC, first freewheeling device D1, capacitor C1, second switch Q2, inductor L1, and AC power source AC form a loop, and the current flows as shown by the dotted line in FIG3 .

[0061] According to an embodiment of the present disclosure, when the conversion bridge 110 operates in a continuous conduction mode, the first switch tube Q1 and the second switch tube Q2 are respectively turned on or off continuously, and the first switch tube Q1 and the second switch tube Q2 are turned on or off alternately.

[0062] Specifically, when the converter bridge 110 operates in continuous conduction mode, during the positive half-cycle of the AC power source AC, the controller 130 first controls the second switch Q2 to turn on and the first switch Q1 to turn off. At this point, the AC power source AC, inductor L1, second switch Q2, second freewheeling device D2, and AC power source AC form a loop. The current flows as shown by the dashed line in Figure 4, and the AC power source AC charges inductor L1. Then, the controller 130 controls the first switch Q1 to turn on and the second switch Q2 to turn off. The AC power source AC, inductor L1, first switch Q1, capacitor C1, second freewheeling device D2, and AC power source AC form a loop. The current flows as shown by the dashed line in Figure 5. The charge stored in inductor L1 is released and superimposed with the voltage of the AC power source AC to boost and charge capacitor C1, thereby boosting the voltage and improving the power factor. This cycle continues, with the controller 130 alternatingly turning the first and second switches Q1 and Q2 on and off based on a set frequency.

[0063] During the negative half-cycle of the AC power supply, the controller 130 first turns on the first switch Q1 and turns off the second switch Q2. Although not shown in the diagram, the AC power supply, the first freewheeling device D1, the first switch Q1, the inductor L1, and the AC power supply form a loop, charging the inductor L1. The controller then turns on the second switch Q2 and turns off the first switch Q1. Although not shown in the diagram, the AC power supply, the first freewheeling device D1, the capacitor C1, the second switch Q2, the inductor L1, and the AC power supply form a loop. The stored charge in the inductor L1 is released and superimposed with the voltage of the AC power supply to boost and charge the capacitor C1, thereby boosting the voltage and improving the power factor. In this cycle, the controller 130 controls the first switch Q1 and the second switch Q2 in the first bridge arm 111 to alternately turn on and off based on the set frequency.

[0064] According to one embodiment of the present disclosure, the controller 130 includes a Kalman filter, and processes the temperature information within the target time period through the Kalman filter to obtain a temperature slope.

[0065] Specifically, the temperature detector 120 detects the indoor ambient temperature in real time, obtains 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, and then calculates the temperature slope based on the temperature information. The temperature slope at the next moment can be predicted based on 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 moment, which can further improve the comfort of the indoor environment and improve efficiency.

[0066] According to another embodiment of the present disclosure, the controller 130 processes the temperature information within the target time period based on a recursive line approximation method to obtain a temperature slope.

[0067] 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.

[0068] In one embodiment of the present disclosure, the power conversion device 100 further includes an EMI filter, which can be disposed between the AC power source AC and the inductor L1. The EMI filter can filter out high-frequency and high-order harmonics in the AC power output by the AC power source AC, thereby preventing these high-frequency and high-order harmonics from affecting the power conversion device 100 and improving the stability of the power conversion device 100.

[0069] In summary, the power conversion device according to the disclosed embodiment stabilizes the output voltage of the converter bridge using a capacitor to provide a DC power supply. A temperature detector detects the indoor ambient temperature to obtain temperature information. A controller determines a temperature slope based on this temperature information and controls the switches in multiple components based on the temperature slope to switch the converter bridge's operating mode between discontinuous conduction mode and continuous conduction mode. Thus, the device can switch the converter bridge's operating mode based on the indoor ambient temperature slope, accurately tracking the room temperature, improving indoor comfort, and increasing efficiency.

[0070] Corresponding to the above embodiment, the present disclosure also proposes a refrigeration device.

[0071] FIG6 is a block diagram of a refrigeration device according to an embodiment of the present disclosure.

[0072] As shown in FIG6 , the refrigeration device 200 according to the embodiment of the present disclosure includes a compressor 210 ; and the power conversion device 100 described above, adapted to convert an input AC power supply into a DC power supply to power the compressor 210 .

[0073] According to the refrigeration equipment of the embodiment of the present disclosure, through the above-mentioned power conversion device, the working mode of the conversion bridge can be switched according to the temperature slope of the indoor environment, and the room temperature can be accurately tracked, the comfort of the indoor environment can be improved, and the efficiency can be improved.

[0074] Corresponding to the above embodiment, the present disclosure further proposes a method for controlling a PFC circuit in a refrigeration device.

[0075] FIG7 is a flow chart of a method for controlling a PFC circuit in a refrigeration device according to an embodiment of the present disclosure.

[0076] In one embodiment of the present disclosure, as shown in Figure 8, a PFC circuit may include a converter bridge 110, an inductor L1, and a capacitor C1. The converter bridge 110 includes multiple components connected in a bridge shape and has an input and an output. The inductor L1 is connected between the AC power source (AC) and the input terminal. The inductor L1 is capable of storing power supplied by the AC power source (AC) and releasing the stored energy to boost the voltage and improve the power factor. The capacitor C1 is connected to the output terminal and is suitable for stabilizing the output voltage of the converter bridge to provide a DC power supply. The multiple components include a first switching transistor Q1, a second switching transistor Q2, a first freewheeling device D1, and a second freewheeling device D2. The first switching transistor Q1 and the second switching transistor 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 midpoint of the first bridge arm 111 and the midpoint of the second bridge arm 112 serve as input terminals, and both ends of the first bridge arm 111 or the second bridge arm 112 serve as output terminals. The midpoint of the first bridge arm 111 is connected to the AC power supply AC via an inductor L1. 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.

[0077] As shown in FIG7 , the control method of the PFC circuit in the refrigeration equipment according to the embodiment of the present disclosure may include the following steps:

[0078] S1, detect the indoor ambient temperature and obtain temperature information.

[0079] S2, determining a temperature slope according to the temperature information, and controlling a switch tube in the PFC circuit according to the temperature slope to switch an operating mode of the PFC circuit, wherein the operating mode of the PFC circuit includes a discontinuous conduction mode and a continuous conduction mode.

[0080] Specifically, the AC power source's electrical energy is converted via an inductor input to a converter bridge. A capacitor smoothes the output voltage from the converter bridge into a DC voltage, which is then fed to the refrigeration unit's compressor to power the compressor. Once the compressor is running, the refrigeration unit can heat or cool the indoor environment according to user demand. During compressor operation, a temperature detector measures the indoor ambient temperature in real time, obtains temperature information, and transmits it to a controller. The controller calculates a temperature slope from discrete sampled temperature data within any time range and, based on this temperature slope, controls the switches in multiple components to switch the converter bridge's operating mode between discontinuous conduction mode and continuous conduction mode. For example, in the initial cooling phase of a refrigeration unit, the indoor temperature rapidly decreases from high to low. This corresponds to a larger temperature slope, indicating a high cooling load. The controller can then use the PFC circuit to drive the compressor in continuous conduction mode. As cooling progresses, the indoor temperature gradually approaches the set temperature. The corresponding temperature slope decreases, indicating a low cooling load. The controller can then use the PFC circuit to drive the compressor in discontinuous conduction mode. Therefore, by switching the operating mode of the compressor motor, the efficiency of the compressor and the circuit can be improved, and the room temperature can be accurately tracked, the comfort of the indoor environment can be improved, and the efficiency can be improved.

[0081] According to an embodiment of the present disclosure, determining a temperature slope based on temperature information includes: processing temperature information within a target time period using a Kalman filter to obtain a temperature slope.

[0082] Specifically, the indoor ambient temperature can be detected in real time through a temperature detector to obtain temperature information and transmit it 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, and then calculates the temperature slope based on the temperature information. The temperature slope at the next moment can be predicted based on 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 moment, which can further improve the comfort of the indoor environment and improve efficiency.

[0083] According to another embodiment of the present disclosure, determining a temperature slope according to temperature information includes: processing temperature information within a target time period based on a recursive line approximation method to obtain a temperature slope.

[0084] Specifically, after obtaining the temperature information, the controller 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.

[0085] According to one embodiment of the present disclosure, controlling a switch in a PFC circuit based on a temperature slope includes: when the temperature slope is greater than or equal to a first set threshold, controlling a first switch and a second switch to be continuously turned on or off, respectively, with the first switch and the second switch being alternately turned on or off, so that the PFC circuit operates in a continuous conduction mode; and when the temperature slope is less than the first set threshold, controlling the first switch and the second switch to be alternately turned on or off, respectively, with the first switch and the second switch being alternately turned on or off, so that the PFC circuit operates in a discontinuous conduction mode. The first set threshold can be calibrated based on actual conditions.

[0086] Specifically, when the temperature slope is greater than or equal to the first set threshold, the room temperature differs significantly from the set temperature, and the compressor is in a high-load operating state. The controller controls the PFC circuit to operate in a continuous conduction mode. During the positive half cycle of the AC power supply AC, the controller 130 first controls the second switch tube Q2 to be turned on and the first switch tube Q1 to be turned off. At this time, the AC power supply AC, the inductor L1, the second switch tube Q2, the second freewheeling device D2, and the AC power supply AC form a loop. The current flows as shown by the dotted line in FIG4 , and the AC power supply AC charges the inductor L1. Then, the first switch tube Q1 is controlled to be turned on and the second switch tube Q2 is controlled to be 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. The current flows as shown by the dotted line in FIG5 , and the charge stored in the inductor L1 is released and superimposed with the voltage of the AC power supply AC to boost and charge the capacitor C1, thereby boosting the voltage and improving the power factor. In this cycle, the controller 130 controls the first switch Q1 and the second switch Q2 to alternately turn on and off based on the set frequency. During the negative half-cycle of the AC power supply AC, the controller 130 first controls the first switch Q1 to turn on and the second switch Q2 to turn off. Although not shown in the figure, the AC power supply AC, the first freewheeling device D1, the first switch Q1, the inductor L1, and the AC power supply AC form a loop, and the AC power supply AC charges the inductor L1. Then, the controller controls the second switch Q2 to turn on and the first switch Q1 to turn off. Although not shown in the figure, the AC power supply AC, the first freewheeling device D1, the capacitor C1, the second switch Q2, the inductor L1, and the AC power supply AC form a loop. The energy stored in the inductor L1 is released and superimposed with the voltage of the AC power supply AC to boost and charge the capacitor C1, thereby boosting the voltage and improving the power factor. In this cycle, the controller 130 controls the first switch Q1 and the second switch Q2 in the first bridge arm 111 to alternately turn on and off based on the set frequency.

[0087] When the temperature slope is less than the first set threshold, the difference between the room temperature and the set temperature is small, and the compressor is in a low-load state. The controller controls the PFC circuit to operate in discontinuous conduction mode. During the positive half-cycle of the AC power supply AC, the controller 130 turns on the first switch Q1 and turns off the second switch Q2. The AC power supply AC, inductor L1, the first switch Q1, capacitor C1, the second freewheeling device D2, and the AC power supply AC form a loop, and the current flow is shown by the dotted line in Figure 2. Similarly, during the negative half-cycle of the AC power supply AC, the controller 130 turns off the first switch Q1 and turns on the second switch Q2. The AC power supply AC, the first freewheeling device D1, capacitor C1, the second switch Q2, the inductor L1, and the AC power supply AC form a loop, and the current flow is shown by the dotted line in Figure 3.

[0088] According to one embodiment of the present disclosure, the discontinuous conduction mode includes a first burst control mode and a second burst control mode. When the temperature slope is less than a 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, wherein the second set threshold is less than the first set threshold; and 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 cycle corresponding to the second burst control mode is less than the duty cycle corresponding to the first burst control mode. The second set threshold can be calibrated according to actual conditions.

[0089] Specifically, for ease of control, the load range of the compressor can be divided according to the size 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 a 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 a 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 a low load range.

[0090] Specifically, when the temperature slope is less than the first set threshold, when the temperature slope is greater than or equal to the second set threshold, the controller controls the PFC circuit to operate in a first burst control mode. For example, the controller may control the first switch tube and the second switch tube in the PFC circuit to be turned on or off at intervals at a duty cycle of 70%, and the first switch tube and the second switch tube are alternately turned on or off. When the temperature slope is less than the second set threshold, the controller controls the PFC circuit to operate in a second burst control mode. For example, the controller may control the first switch tube and the second switch tube in the PFC circuit to be turned on or off at intervals at a duty cycle of 50% or less, and the first switch tube and the second switch tube are alternately turned on or off.

[0091] In summary, the PFC circuit control method for refrigeration equipment according to the disclosed embodiments first detects the indoor ambient temperature to obtain temperature information. A temperature slope is then determined based on this temperature information. The switching transistor in the PFC circuit is controlled based on the temperature slope to switch the PFC circuit's operating mode between discontinuous conduction mode and continuous conduction mode. This method can thus switch the PFC circuit's operating mode based on the indoor ambient temperature slope, accurately tracking the room temperature, improving indoor comfort, and enhancing efficiency.

[0092] Corresponding to the above embodiments, the present disclosure also proposes a computer-readable storage medium.

[0093] The computer-readable storage medium of the embodiment of the present disclosure stores a control program for a PFC circuit in a refrigeration device. When the program is executed by a processor, the control method for a PFC circuit in a refrigeration device is implemented.

[0094] According to the computer-readable storage medium of the embodiment of the present disclosure, through the above-mentioned control method of the PFC circuit in the refrigeration equipment, the operating 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.

[0095] Corresponding to the above embodiments, the present disclosure also proposes a controller.

[0096] FIG9 is a block diagram of a controller according to an embodiment of the present disclosure.

[0097] As shown in FIG9 , the controller 300 of the embodiment of the present disclosure includes: a memory 310, a processor 320, and a control program for a PFC circuit in a refrigeration device stored in the memory 310 and executable on the processor 320. When the processor 320 executes the program, the control method for a PFC circuit in a refrigeration device described above is implemented.

[0098] According to the controller of the embodiment of the present disclosure, through the above-mentioned control method of the PFC circuit in the refrigeration equipment, the operating 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.

[0099] Corresponding to the above embodiment, the present disclosure also proposes another refrigeration device.

[0100] FIG10 is a block diagram of a refrigeration device according to an embodiment of the present disclosure.

[0101] As shown in FIG10 , a refrigeration device 400 according to an embodiment of the present disclosure includes: a compressor 410; a PFC circuit 420 adapted to provide a DC power supply to the compressor 410, wherein the operating 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 ambient temperature and obtain temperature information; and a controller 440 configured to determine a temperature slope based on the temperature information and control a switch in the PFC circuit 420 based on the temperature slope to switch the operating mode of the PFC circuit 420.

[0102] According to an embodiment of the present disclosure, the controller 440 determines the temperature slope based on the temperature information, specifically, using a Kalman filter to process the temperature information within the target time period to obtain the temperature slope.

[0103] According to another embodiment of the present disclosure, the controller 440 determines a temperature slope according to the temperature information, and is specifically configured to process the temperature information within the target time period based on a recursive line approximation method to obtain the temperature slope.

[0104] According to one embodiment of the present disclosure, the controller 440 controls the switches in the PFC circuit 420 based on a temperature slope. Specifically, when the temperature slope is greater than or equal to a first set threshold, the controller 440 controls the first and second switches to be continuously turned on or off, respectively, and the first and second switches are 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, the controller 440 controls the first and second switches to be alternately turned on or off, respectively, and the first and second switches are alternately turned on or off, so that the PFC circuit 420 operates in a discontinuous conduction mode.

[0105] According to one embodiment of the present disclosure, the discontinuous conduction mode includes a first burst control mode and a second burst control mode. In this case, 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; and 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.

[0106] It should be noted that for details not disclosed in the refrigeration device of the embodiment of the present disclosure, please refer to the details disclosed in the control method of the PFC circuit in the refrigeration device of the embodiment of the present disclosure, and the details will not be repeated here.

[0107] According to the refrigeration equipment of the disclosed embodiment, a PFC circuit provides DC power to the compressor. A temperature detector detects the indoor ambient temperature to obtain temperature information. A controller determines a temperature slope based on the temperature information and controls the switching transistor in the PFC circuit based on the temperature slope to switch the PFC circuit's operating mode between discontinuous conduction mode and continuous conduction mode. Thus, the device can switch the PFC circuit's operating mode based on the indoor ambient temperature slope, accurately tracking the indoor room temperature, improving indoor comfort, and increasing efficiency.

[0108] It should be noted that the logic and / or steps represented in the flowcharts or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing the logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (e.g., a computer-based system, a system including a processor, or other system that can fetch and execute instructions from an instruction execution system, apparatus, or device). For 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 conjunction with, an instruction execution system, apparatus, or device. More specific examples (non-exhaustive list) of computer-readable media include the following: an electrical connection with one or more wires (electronic device), a portable computer disk cartridge (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and programmable read-only memory (EPROM or flash memory), fiber optic devices, and portable compact disc read-only memory (CDROM). Furthermore, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing it in another suitable manner if necessary, and then storing it in a computer memory.

[0109] It should be understood that various parts of the present disclosure can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented using hardware, as in another embodiment, any one of the following technologies known in the art or a combination thereof can be used to implement: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application-specific integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0110] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present disclosure. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0111] Furthermore, 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 being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. Throughout the present disclosure, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0112] In this disclosure, unless otherwise expressly specified or limited, terms such as "installed," "connected," "connect," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components, unless otherwise expressly limited. Those skilled in the art will understand the specific meanings of the above terms in this disclosure based on specific circumstances.

[0113] Although the embodiments of the present disclosure have been shown and described above, it is understood that the above embodiments are illustrative and are not to be construed as limitations on the present disclosure. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present disclosure.

Claims

1. A power conversion device, wherein: Suitable for converting input AC power into DC power to power the compressor of the refrigeration equipment, the power conversion device comprises: A conversion bridge, the conversion bridge comprising a plurality of components, the plurality of components are connected into a bridge shape and is configured with an input end and an output end; an inductor connected between the AC power source and the input terminal; 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 is suitable for detecting the indoor ambient temperature and obtaining temperature information; The controller is configured to determine a temperature slope according to the temperature information, and control the switch tubes in the multiple components according to the temperature slope to switch the working mode of the conversion bridge, wherein the working mode of the conversion bridge includes a discontinuous conduction mode and a continuous conduction mode.

2. The power conversion device according to claim 1, wherein: The multiple 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 constitute a first bridge arm, and the first freewheeling device and the second freewheeling device constitute a second bridge arm. The midpoint of the first bridge arm and the midpoint of 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.

3. The power conversion device according to claim 2, wherein: The first switch tube and the second switch 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, wherein: The first switch tube and the second switch tube are respectively gallium nitride MOSFETs, and the first freewheeling device and the second freewheeling device are respectively diodes.

5. The power conversion device according to any one of claims 1 to 4, wherein: The temperature detector is arranged at the air inlet of the indoor unit of the refrigeration equipment.

6. The power conversion device according to any one of claims 2 to 4, wherein: When the conversion bridge operates in the discontinuous conduction mode, the first switch tube and the second switch tube are respectively turned on or off at intervals, and the first switch tube and the second switch tube are turned on or off alternately.

7. The power conversion device according to any one of claims 2 to 4, wherein: When the conversion bridge operates in the continuous conduction mode, the first switch tube and the second switch tube are respectively turned on or off continuously, and the first switch tube and the second switch tube are turned on or off alternately.

8. The power conversion device according to any one of claims 1 to 7, wherein: The controller includes a Kalman filter, and the temperature information within a target time period is processed by the Kalman filter to obtain the temperature slope.

9. The power conversion device according to any one of claims 1 to 7, wherein: The controller processes the temperature information within a target time period based on a recursive line approximation method to obtain the temperature slope.

10. A refrigeration device, wherein: include: compressor; The power conversion device according to any one of claims 1 to 9 is suitable for converting input AC power into DC power to power the compressor.

11. A method for controlling a PFC circuit in a refrigeration device, wherein: The method comprises: Detect the indoor ambient temperature and obtain temperature information; A temperature slope is determined according to the temperature information, and a switch tube in the PFC circuit is controlled according to the temperature slope to switch an operating mode of the PFC circuit, wherein the operating mode of the PFC circuit includes a discontinuous conduction mode and a continuous conduction mode.

12. The method according to claim 11, wherein: Determining a temperature slope according to the temperature information includes: The temperature information in the target time period is processed by using a Kalman filter to obtain the temperature slope.

13. The method according to claim 11, wherein: Determining a temperature slope according to the temperature information includes: The temperature slope is obtained by processing the temperature information in the target time period based on the recursive line approximation method.

14. The method according to any one of claims 11 to 13, wherein: Controlling a switch 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 switch tube and the second switch tube to be turned on or off respectively and the first switch tube and the second switch tube to be turned on or off alternately, so that the PFC circuit operates in the continuous conduction mode; When the temperature slope is less than a first set threshold, the first switch tube and the second switch tube are controlled to be turned on or off at intervals, and the first switch tube and the second switch tube are turned on or off alternately, so that the PFC circuit operates in the discontinuous conduction mode.

15. The method according to claim 14, wherein: 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 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, wherein the second set threshold is less than the first set threshold; If the temperature slope is less than a second set threshold, the PFC circuit is controlled to operate in the second Burst control mode, wherein the duty cycle corresponding to the second Burst control mode is smaller than the duty cycle corresponding to the first Burst control mode.

16. A computer-readable storage medium, wherein: A control program for a PFC circuit in a refrigeration device is stored thereon, and when the program is executed by a processor, a control method for a PFC circuit in a refrigeration device according to any one of claims 11-15 is implemented.

17. A controller, wherein: include: A memory, a processor, and a control program for a PFC circuit in a refrigeration device stored in the memory and executable on the processor, wherein when the processor executes the program, a control method for a PFC circuit in a refrigeration device according to any one of claims 11 to 15 is implemented.

18. A refrigeration device, wherein: include: compressor; A PFC circuit adapted to provide a DC power supply to the compressor, wherein the operating modes of the PFC circuit include a discontinuous conduction mode and a continuous conduction mode; A temperature detector is suitable for detecting the indoor ambient temperature and obtaining temperature information; The controller is configured to determine a temperature slope according to the temperature information, and control a switch tube in the PFC circuit according to the temperature slope to switch an operating mode of the PFC circuit.

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