Control method of PFC circuit of air conditioner, outdoor unit control circuit and air conditioner

Abstract

The invention discloses a control method of a PFC circuit of an air conditioner, an outdoor unit control circuit and the air conditioner, the PFC circuit comprises a first bridge arm and a second bridge arm, the first bridge arm comprises a first gallium nitride switching tube and a second gallium nitride switching tube which are connected in series, and the air conditioner comprises a load module powered by the PFC circuit. The load module comprises a compressor. The method comprises the steps that the running state of the compressor is obtained; and controlling the first gallium nitride switching tube and the second gallium nitride switching tube according to the running state so as to reduce current flowing through a fly-wheel diode of the first gallium nitride switching tube and a fly-wheel diode of the second gallium nitride switching tube in the starting process of the compressor. A large current is prevented from flowing through a fly-wheel diode of the gallium nitride switch tube for a long time, so that the risk of burning of the gallium nitride switch tube is reduced, and the problem of burning of the gallium nitride switch tube is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioning circuits, and in particular to a control method for a PFC circuit of an air conditioner, an outdoor unit control circuit and an air conditioner. Background Art

[0002] At present, with the development of semiconductors, more efficient GaN switches are gradually being used in PFC circuits. However, due to the large voltage drop of GaN switches and the poor overcurrent capacity of the internal diodes, when GaN switches are used as rectifier diodes during compressor startup, the current flowing through the internal diodes of GaN switches is large, which can easily burn the GaN switches. Summary of the invention

[0003] The purpose of the present invention is to solve at least one of the technical problems existing in the prior art, and to provide a control method for a PFC circuit of an air conditioner, an external unit control circuit and an air conditioner, which can solve the problem of burning of a gallium nitride switch tube.

[0004] In a first aspect, an embodiment of the present invention provides a control method for a PFC circuit of an air conditioner, wherein the PFC circuit includes a first bridge arm and a second bridge arm, wherein the first bridge arm includes a first gallium nitride switch tube and a second gallium nitride switch tube connected in series, and the air conditioner includes a load module powered by the PFC circuit, wherein the load module includes a compressor, and the method includes:

[0005] Acquiring the operating status of the compressor;

[0006] The first gallium nitride switch tube and the second gallium nitride switch tube are controlled according to the operating state to reduce the current flowing through the freewheeling diode of the first gallium nitride switch tube and the freewheeling diode of the second gallium nitride switch tube during the startup of the compressor.

[0007] The control method of the PFC circuit of the air conditioner provided by the embodiment of the present invention has at least the following beneficial effects: by acquiring the operating state of the compressor and controlling the first gallium nitride switch tube and the second gallium nitride switch tube according to the operating state of the compressor, the current flowing through the freewheeling diode of the gallium nitride switch tube during the startup of the compressor is reduced, thereby avoiding a large current flowing through the freewheeling diode of the gallium nitride switch tube for a long time, thereby reducing the risk of burning of the gallium nitride switch tube and solving the problem of burning of the gallium nitride switch tube.

[0008] According to some embodiments of the present invention, the control method of the PFC circuit of the air conditioner is provided, wherein the operating state of the compressor includes an open-loop control state during the startup process, and the controlling of the first gallium nitride switch tube and the second gallium nitride switch tube according to the operating state includes:

[0009] When the compressor is in the open-loop control state, in the positive half cycle of the AC power supply, the first gallium nitride switch tube is controlled to be turned on and the second gallium nitride switch tube is controlled to be turned off. In the negative half cycle of the AC power supply, the first gallium nitride switch tube is controlled to be turned off and the second gallium nitride switch tube is controlled to be turned on.

[0010] According to the control method of the PFC circuit of an air conditioner provided in some embodiments of the present invention, the air conditioner also includes a power module for inverting the output voltage of the PFC circuit to supply the compressor, and the open-loop control state is to control the power module according to a given first drive control current.

[0011] According to the control method of the PFC circuit of the air conditioner provided by some embodiments of the present invention, the operating state of the compressor also includes a positioning state and a closed-loop control state, the positioning state is to control the power module according to a given second drive control current, and the closed-loop control state is to control the power module according to a given third drive control current and the actual operating parameters of the compressor.

[0012] In a second aspect, an embodiment of the present invention provides an external unit control circuit of an air conditioner, including a PFC circuit, a load module and an MCU module, wherein:

[0013] The PFC circuit comprises a first bridge arm and a second bridge arm, wherein the first bridge arm comprises a first gallium nitride switch tube and a second gallium nitride switch tube connected in series;

[0014] The load module includes a compressor powered by the PFC circuit;

[0015] The MCU module is connected to the load module and the PFC circuit respectively, and is used to obtain the operating status of the compressor, and control the first gallium nitride switch tube and the second gallium nitride switch tube according to the operating status, so as to reduce the current flowing through the freewheeling diode of the first gallium nitride switch tube and the freewheeling diode of the second gallium nitride switch tube during the startup of the compressor.

[0016] The external unit control circuit of the air conditioner provided according to the embodiment of the present invention has at least the following beneficial effects: by acquiring the operating state of the compressor and controlling the first gallium nitride switch tube and the second gallium nitride switch tube according to the operating state of the compressor, the current flowing through the freewheeling diode of the gallium nitride switch tube during the startup of the compressor is reduced, thereby avoiding a large current flowing through the freewheeling diode of the gallium nitride switch tube for a long time, thereby reducing the risk of burning of the gallium nitride switch tube and solving the problem of burning of the gallium nitride switch tube.

[0017] According to the external machine control circuit provided by some embodiments of the present invention, the PFC circuit also includes a first inductor and a first capacitor, the second bridge arm includes a third switch tube and a fourth switch tube connected in series, one end of the AC power supply is connected to the connection point of the first gallium nitride switch tube and the second gallium nitride switch tube through the first inductor, the other end of the AC power supply is connected to the connection point of the third switch tube and the fourth switch tube, the first gallium nitride switch tube and the third switch tube are connected to one end of the first capacitor, and the second gallium nitride switch tube and the fourth switch tube are connected to the other end of the first capacitor.

[0018] The external machine control circuit provided according to some embodiments of the present invention further includes an input voltage sampling module connected to the first inductor, and an output end of the input voltage sampling module is connected to the MCU module.

[0019] The external machine control circuit provided according to some embodiments of the present invention further includes an input current sampling module connected to the first inductor, and an output end of the input current sampling module is connected to the MCU module.

[0020] The external machine control circuit provided according to some embodiments of the present invention further includes an output voltage sampling module connected to the first capacitor, and an output end of the output voltage sampling module is connected to the MCU module.

[0021] In a third aspect, an embodiment of the present invention provides an operation control device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the control method as described in the embodiment of the first aspect above.

[0022] The operation control device provided according to the embodiment of the present invention has at least the following beneficial effects: by acquiring the operating status of the compressor and controlling the first gallium nitride switch tube and the second gallium nitride switch tube according to the operating status of the compressor, the current flowing through the freewheeling diode of the gallium nitride switch tube during the startup of the compressor is reduced, thereby avoiding a large current flowing through the freewheeling diode of the gallium nitride switch tube for a long time, thereby reducing the risk of burning of the gallium nitride switch tube and solving the problem of burning of the gallium nitride switch tube.

[0023] In a fourth aspect, an embodiment of the present invention provides an air conditioner, comprising the external unit control circuit as described in the embodiment of the second aspect above or comprising the operation control device as described in the embodiment of the third aspect above.

[0024] The air conditioner provided according to the embodiment of the present invention has at least the following beneficial effects: by acquiring the operating status of the compressor and controlling the first gallium nitride switch tube and the second gallium nitride switch tube according to the operating status of the compressor, the current flowing through the freewheeling diode of the gallium nitride switch tube during the startup of the compressor is reduced, thereby avoiding a large current flowing through the freewheeling diode of the gallium nitride switch tube for a long time, thereby reducing the risk of burning out the gallium nitride switch tube and solving the problem of burning out the gallium nitride switch tube.

[0025] In a fifth aspect, an embodiment of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer-executable instructions, and the computer-executable instructions are used to enable a computer to execute the control method as described in the embodiment of the first aspect above.

[0026] The computer-readable storage medium provided according to the embodiment of the present invention has at least the following beneficial effects: by acquiring the operating status of the compressor and controlling the first gallium nitride switch tube and the second gallium nitride switch tube according to the operating status of the compressor, the current flowing through the freewheeling diode of the gallium nitride switch tube during the startup of the compressor is reduced, thereby avoiding a large current flowing through the freewheeling diode of the gallium nitride switch tube for a long time, thereby reducing the risk of burning of the gallium nitride switch tube and solving the problem of burning of the gallium nitride switch tube.

[0027] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings are used to provide a further understanding of the technical solution of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the technical solution of the present invention and do not constitute a limitation on the technical solution of the present invention.

[0029] The present invention is further described below in conjunction with the accompanying drawings and embodiments;

[0030] Figure 1 is a circuit schematic diagram of a PFC circuit of an air conditioner provided by an embodiment of the present invention;

[0031] Figure 2 is a flow chart of a method for controlling a PFC circuit of an air conditioner provided by an embodiment of the present invention;

[0032] Figure 3 is an operating state diagram of a compressor of an air conditioner provided by an embodiment of the present invention;

[0033] Figure 4is a flow chart of a method for controlling a PFC circuit of an air conditioner provided by another embodiment of the present invention;

[0034] Figure 5 It is a structural schematic diagram of the operation control device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0035] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present invention, but it cannot be understood as a limitation on the scope of protection of the present invention.

[0036] In the description of the embodiments of the present invention, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed", etc. are understood to exclude the number itself, "above", "below", "within", etc. are understood to include the number itself, "at least one" means one or more, "at least one of the following" and similar expressions refer to any combination of these items, including any combination of single or plural items. If there is a description of "first", "second", etc., it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0037] It should be noted that the terms such as setting, installing, and connecting in the embodiments of the present invention should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above terms in the embodiments of the present invention in combination with the specific content of the technical solution. For example, the term "connection" can be a mechanical connection, an electrical connection, or mutual communication; it can be directly connected or indirectly connected through an intermediate medium.

[0038] It should be noted that the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0039] At present, with the development of semiconductors, more efficient GaN switches are gradually being used in PFC circuits. However, due to the large voltage drop of GaN switches and the poor overcurrent capacity of the internal diodes, when GaN switches are used as rectifier diodes during compressor startup, the current flowing through the internal diodes of GaN switches is large, which can easily burn the GaN switches.

[0040] Based on this, an embodiment of the present invention provides a control method for a PFC circuit of an air conditioner, an external unit control circuit and an air conditioner. By obtaining the operating status of the compressor and controlling the first gallium nitride switch tube and the second gallium nitride switch tube according to the operating status of the compressor, the current flowing through the freewheeling diode of the gallium nitride switch tube during the startup of the compressor is reduced, thereby avoiding a large current flowing through the freewheeling diode of the gallium nitride switch tube for a long time, thereby reducing the risk of burning out the gallium nitride switch tube and solving the problem of burning out the gallium nitride switch tube.

[0041] The embodiments of the present invention are further described below in conjunction with the accompanying drawings.

[0042] Reference Figure 1 , Figure 1: is a circuit schematic diagram of the PFC circuit of the air conditioner provided by an embodiment of the present invention. The PFC circuit includes a first bridge arm and a second bridge arm, the first bridge arm includes a first gallium nitride switch tube Q1 and a second gallium nitride switch tube Q2 connected in series, the air conditioner includes a load module powered by the PFC circuit, and the load module includes a compressor. It can be understood that the PFC circuit also includes a first inductor L and a first capacitor C1, the second bridge arm includes a third switch tube Q3 and a fourth switch tube 34 connected in series, one end of the AC power supply AC is connected to the connection point of the first gallium nitride switch tube Q1 and the second gallium nitride switch tube Q2 through the first inductor L, the other end of the AC power supply AC is connected to the connection point of the third switch tube Q3 and the fourth switch tube Q4, the first gallium nitride switch tube Q1 and the third switch tube Q2 are connected to one end of the first capacitor C1, and the second gallium nitride switch tube Q3 and the fourth switch tube Q4 are connected to the other end of the first capacitor C1. In addition, the load module also includes loads such as fans and switching power supplies. In addition, the air conditioner also includes an MCU module, which outputs a PWM control signal to the control pins of the first gallium nitride switch tube Q1, the second gallium nitride switch tube Q2, the third switch tube Q3 and the fourth switch tube Q4, thereby controlling the conduction and shutdown of the first gallium nitride switch tube Q1, the second gallium nitride switch tube Q2, the third switch tube Q3 and the fourth switch tube Q4 to achieve control of the PFC circuit operation mode. It can also be seen that the air conditioner also includes an input voltage sampling module and an input current sampling module connected to the input side of the PFC circuit, and an output voltage sampling module connected to the output side of the PFC circuit. Specifically, the input end of the input voltage sampling module is connected to the connection point between the AC power supply AC and the first inductor L, and the output end of the input voltage sampling module can be connected to the input port of the MCU module to transmit the measured input voltage Vac to the MCU module; the input end of the input current sampling module can be connected to the connection point between the first inductor L and the first bridge arm, and the output end of the input current sampling module is connected to the input port of the MCU module to transmit the measured input current Ipfc to the MCU module; the input end of the output voltage sampling module is connected to the connection point between the first capacitor C1 and the load module, and the output end of the output voltage sampling module can be connected to the input port of the MCU module to transmit the measured output voltage Vbus to the MCU module; the input port of the MCU module can also be connected to the load module to obtain the actual operating parameters of the load module, for example, it can be connected to the compressor to obtain the speed of the compressor.

[0043] When the air conditioner is running, if the load is small, if the high-frequency PFC control mode is turned on directly, the switching frequency of the switch tube will be high, which will cause greater circuit loss. Therefore, the control method currently used in air conditioners is to wait for the compressor to enter the closed-loop control mode before the high-frequency PFC control mode is performed. The fourth-generation semiconductor GaN power tube with higher efficiency has poor overcurrent capacity of the internal freewheeling diode. When used as a high-frequency switch tube for bridgeless (totem pole) PFC, if the GaN power tube is used as a rectifier diode during the open-loop startup process of the compressor, the current flowing through is large and will burn the GaN power tube.

[0044] Reference Figure 2 A first aspect of the present invention provides a method for controlling a PFC circuit of an air conditioner, which is applied to Figure 1 The PFC circuit of the air conditioner shown in the figure, the control method includes but is not limited to steps S210 to S220:

[0045] Step S210: obtaining the operating status of the compressor;

[0046] Step S220: controlling the first gallium nitride switch tube and the second gallium nitride switch tube according to the operating state to reduce the current flowing through the freewheeling diode of the first gallium nitride switch tube and the freewheeling diode of the second gallium nitride switch tube during the compressor startup process.

[0047] According to the control method of the PFC circuit of the air conditioner provided by the embodiment of the present invention, the operating state of the compressor is obtained, and the first gallium nitride switch tube and the second gallium nitride switch tube are controlled according to the operating state of the compressor, so as to reduce the current flowing through the freewheeling diode of the gallium nitride switch tube during the startup of the compressor, thereby avoiding a large current flowing through the freewheeling diode of the gallium nitride switch tube for a long time, thereby reducing the risk of burning of the gallium nitride switch tube and solving the problem of burning of the gallium nitride switch tube.

[0048] It should be noted that the operating status of the compressor is Figure 3As shown, the compressor generally has three states from stopping to stable operation, namely: positioning state, open-loop control state and closed-loop control state. It can be understood that the air conditioner also includes a power module that inverts the output voltage of the PFC circuit to supply the compressor, that is, the input end of the power module is connected to the output end of the PFC circuit to obtain direct current, and the direct current is inverted to obtain the AC drive voltage required by the compressor. It should also be noted that when the compressor starts, it will first enter the positioning state. At this time, the MCU module performs PWM control according to the given drive control current, and outputs the corresponding PWM signal to the power module to control each switch tube of the power module; after the compressor is positioned, it enters the open-loop control state. In this state, the MCU module will also perform PWM control according to the given drive control current, and output the corresponding PWM signal to the power module to control each switch tube of the power module, and will not perform feedback adjustment based on the actual operating parameters of the compressor combined with the given control data; after the open-loop control state runs for a period of time, the MCU module will start to collect the actual operating parameters of the compressor and combine the required power of the compressor to control the power module.

[0049] In the control method of the PFC circuit of the air conditioner provided by some embodiments of the present invention, the operating state of the compressor includes an open-loop control state during the startup process, and the step S220 of controlling the first gallium nitride switch tube and the second gallium nitride switch tube according to the operating state includes:

[0050] When the compressor is in an open-loop control state, in the positive half cycle of the AC power supply, the first gallium nitride switch tube is controlled to be turned on and the second gallium nitride switch tube is controlled to be turned off. In the negative half cycle of the AC power supply, the first gallium nitride switch tube is controlled to be turned off and the second gallium nitride switch tube is controlled to be turned on.

[0051] It can be understood that, due to the open-loop control state during the compressor startup process, the current flowing through the PFC circuit is relatively large. If the first gallium nitride switch tube and the second gallium nitride switch tube are used as rectifier tube diodes at this time, the current flowing through the freewheeling diodes inside the first gallium nitride switch tube and the second gallium nitride switch tube will also be very large. Therefore, in this embodiment, by controlling the first gallium nitride switch tube to be turned on and the second gallium nitride switch tube to be turned off in the positive half cycle of the AC power supply, and controlling the first gallium nitride switch tube to be turned off and the second gallium nitride switch tube to be turned on in the negative half cycle of the AC power supply, it is avoided that a large current flows through the freewheeling diode of the gallium nitride switch tube for a long time, thereby reducing the risk of burning out the gallium nitride switch tube.

[0052] Reference Figure 4 , Figure 4This is a flow chart of a control method for a PFC circuit of an air conditioner provided by an embodiment of the present invention. When the compressor is in a stopped state and needs to be started, it first enters a positioning state, and then the MCU module determines whether the compressor enters a switch control state according to the drive control current applied to the power module of the compressor; if the compressor enters an open-loop control state, the voltage of the AC power supply is judged; if the voltage of the AC power supply is greater than 0, it is in a positive half-cycle, at which time the first gallium nitride switch tube Q1 is controlled to be turned on and the second gallium nitride switch tube Q2 is controlled to be turned off; if the voltage of the AC power supply is less than 0, it is in a negative half-cycle, at which time the first gallium nitride switch tube Q1 is controlled to be turned off and the second gallium nitride switch tube Q2 is controlled to be turned on; if the compressor does not enter an open-loop control state, it enters a PFC control mode, for example, high-frequency switch control of the PFC circuit is performed.

[0053] In the control method of the PFC circuit of the air conditioner provided in some embodiments of the present invention, the air conditioner also includes a power module that inverts the output voltage of the PFC circuit to supply the compressor, and the open-loop control state is to control the power module according to a given first drive control current.

[0054] It should be noted that, in the open-loop control state, the given first drive control current is generally obtained by synthesizing the direct-axis current Id and the quadrature-axis current Iq.

[0055] In the control method of the PFC circuit of the air conditioner provided in some embodiments of the present invention, the operating state of the compressor also includes a positioning state and a closed-loop control state. The positioning state is to control the power module according to a given second drive control current, and the closed-loop control state is to control the power module according to a given third drive control current and the actual operating parameters of the compressor.

[0056] It should be noted that, in the positioning state, the given second drive control current generally only includes the DC current Id; in the closed-loop control state, the given third drive control current is generally synthesized by the direct-axis current Id and the quadrature-axis current Iq, and the third drive control current is generally converted from the required power of the compressor.

[0057] Reference Figure 1 According to a second aspect of the present invention, an external unit control circuit of an air conditioner is provided, including a PFC circuit, a load module and an MCU module, wherein:

[0058] The PFC circuit includes a first bridge arm and a second bridge arm, wherein the first bridge arm includes a first gallium nitride switch tube Q1 and a second gallium nitride switch tube Q2 connected in series;

[0059] The load module includes a compressor powered by the PFC circuit;

[0060] The MCU module is connected to the load module and the PFC circuit respectively, and is used to obtain the operating state of the compressor, and control the first gallium nitride switch tube and the second gallium nitride switch tube according to the operating state, so as to reduce the current flowing through the freewheeling diode of the first gallium nitride switch tube and the freewheeling diode of the second gallium nitride switch tube during the compressor startup process. Specifically, the MCU module can be used to execute the control method of the PFC circuit described in the first aspect embodiment.

[0061] The external unit control circuit of the air conditioner provided by the embodiment of the present invention obtains the operating status of the compressor and controls the first gallium nitride switch tube and the second gallium nitride switch tube according to the operating status of the compressor to reduce the current flowing through the freewheeling diode of the gallium nitride switch tube during the startup of the compressor, thereby avoiding a large current flowing through the freewheeling diode of the gallium nitride switch tube for a long time, thereby reducing the risk of burning out the gallium nitride switch tube and solving the problem of burning out the gallium nitride switch tube.

[0062] Reference Figure 1 In the external machine control circuit provided in some embodiments of the present invention, the PFC circuit further includes a first inductor L and a first capacitor C1, the second bridge arm includes a third switch tube Q3 and a fourth switch tube Q4 connected in series, one end of the AC power supply AC is connected to the connection point of the first gallium nitride switch tube Q1 and the second gallium nitride switch tube Q2 through the first inductor L, the other end of the AC power supply AC is connected to the connection point of the third switch tube Q3 and the fourth switch tube Q4, the first gallium nitride switch tube Q1 and the third switch tube Q3 are connected to one end of the first capacitor C1, and the second gallium nitride switch tube Q2 and the fourth switch tube Q4 are connected to the other end of the first capacitor C1.

[0063] Reference Figure 1 In some embodiments of the present invention, the external machine control circuit further includes an input voltage sampling module connected to the first inductor L, and the output end of the input voltage sampling module is connected to the MCU module.

[0064] In this embodiment, the input voltage sampling module transmits the collected input voltage Vac to the MCU module, so that the MCU module controls the PFC circuit.

[0065] Reference Figure 1 In some embodiments of the present invention, the external machine control circuit further includes an input current sampling module connected to the first inductor L, and the output end of the input current sampling module is connected to the MCU module.

[0066] In this embodiment, the input voltage sampling module transmits the collected input current Ipfc to the MCU module, so that the MCU module controls the PFC circuit.

[0067] In the external machine control circuit provided in some embodiments of the present invention, it further includes an output voltage sampling module connected to the first capacitor C1, and the output end of the output voltage sampling module is connected to the MCU module.

[0068] In this embodiment, the output voltage sampling module transmits the collected output voltage Vbus to the MCU module, so that the MCU module controls the PFC circuit.

[0069] In addition, refer to Figure 5 The third aspect of the present invention provides an operation control device 500, including a memory 510, a processor 520, and a computer program stored in the memory 510 and executable on the processor 520. The processor 520 executes the program to implement the control method of the first aspect of the present invention, for example, to execute Figure 2 Method steps S210 to S220.

[0070] According to the operation control device provided by the embodiment of the present invention, the operating status of the compressor is obtained, and the first gallium nitride switch tube and the second gallium nitride switch tube are controlled according to the operating status of the compressor, so as to reduce the current flowing through the freewheeling diode of the gallium nitride switch tube during the startup of the compressor, thereby avoiding a large current flowing through the freewheeling diode of the gallium nitride switch tube for a long time, thereby reducing the risk of burning of the gallium nitride switch tube and solving the problem of burning of the gallium nitride switch tube.

[0071] In a fourth aspect, an embodiment of the present invention provides an air conditioner, comprising an external unit control circuit according to the embodiment of the second aspect or comprising an operation control device 500 according to the embodiment of the third aspect.

[0072] According to the air conditioner provided by the embodiment of the present invention, the operating status of the compressor is obtained, and the first gallium nitride switch tube and the second gallium nitride switch tube are controlled according to the operating status of the compressor, so as to reduce the current flowing through the freewheeling diode of the gallium nitride switch tube during the startup of the compressor, thereby avoiding a large current flowing through the freewheeling diode of the gallium nitride switch tube for a long time, thereby reducing the risk of burning of the gallium nitride switch tube and solving the problem of burning of the gallium nitride switch tube.

[0073] In a fifth aspect, an embodiment of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer-executable instructions, and the computer-executable instructions are used to enable a computer to execute the control method of the first aspect embodiment above, for example, to execute Figure 2 Method steps S210 to S220.

[0074] According to the computer-readable storage medium provided in an embodiment of the present invention, the operating status of the compressor is obtained, and the first gallium nitride switch tube and the second gallium nitride switch tube are controlled according to the operating status of the compressor, so as to reduce the current flowing through the freewheeling diode of the gallium nitride switch tube during the startup of the compressor, thereby avoiding a large current flowing through the freewheeling diode of the gallium nitride switch tube for a long time, thereby reducing the risk of burning of the gallium nitride switch tube and solving the problem of burning of the gallium nitride switch tube.

[0075] It will be appreciated by those skilled in the art that all or some of the steps and systems in the disclosed methods above may be implemented as software, firmware, hardware and appropriate combinations thereof. Some physical components or all physical components may be implemented as software executed by a processor, such as a central processing unit, a digital signal processor or a microprocessor, or implemented as hardware, or implemented as an integrated circuit, such as an application specific integrated circuit. Such software may be distributed on a computer-readable medium, which may include a computer storage medium or a non-transitory medium and a communication medium or a temporary medium. As known to those skilled in the art, the term computer storage medium includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information such as computer-readable instructions, data structures, program modules or other data. Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disk DVD or other optical disk storage, magnetic cassettes, magnetic tapes, disk storage or other magnetic storage devices, or any other medium that may be used to store desired information and may be accessed by a computer. Furthermore, it is well known to those skilled in the art that communication media typically embodies computer readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism, and may include any information delivery media.

[0076] The embodiments of the present invention are described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Various changes can be made within the knowledge scope of ordinary technicians in the technical field without departing from the purpose of the present invention.

Claims

1. A method for controlling a PFC circuit of an air conditioner, characterized in that: The PFC circuit includes a first bridge arm and a second bridge arm, the first bridge arm includes a first gallium nitride switch tube and a second gallium nitride switch tube connected in series, the air conditioner includes a load module powered by the PFC circuit, the load module includes a compressor, and the method includes: Acquiring the operating status of the compressor; The first gallium nitride switch tube and the second gallium nitride switch tube are controlled according to the operating state to reduce the current flowing through the freewheeling diode of the first gallium nitride switch tube and the freewheeling diode of the second gallium nitride switch tube during the startup of the compressor.

2. The control method according to claim 1, characterized in that: The operating state of the compressor includes an open-loop control state during startup, and the controlling the first gallium nitride switch tube and the second gallium nitride switch tube according to the operating state includes: When the compressor is in the open-loop control state, in the positive half cycle of the AC power supply, the first gallium nitride switch tube is controlled to be turned on and the second gallium nitride switch tube is controlled to be turned off. In the negative half cycle of the AC power supply, the first gallium nitride switch tube is controlled to be turned off and the second gallium nitride switch tube is controlled to be turned on.

3. The control method according to claim 2, characterized in that: The air conditioner further includes a power module for inverting the output voltage of the PFC circuit to supply the power to the compressor, and the open-loop control state is to control the power module according to a given first drive control current.

4. The control method according to claim 3, characterized in that: The operating state of the compressor also includes a positioning state and a closed-loop control state. The positioning state is to control the power module according to a given second drive control current, and the closed-loop control state is to control the power module according to a given third drive control current and actual operating parameters of the compressor.

5. An outdoor unit control circuit of an air conditioner, characterized in that: include: The PFC circuit comprises a first bridge arm and a second bridge arm, wherein the first bridge arm comprises a first gallium nitride switch tube and a second gallium nitride switch tube connected in series; a load module, comprising a compressor powered by the PFC circuit; The MCU module is connected to the load module and the PFC circuit respectively, and is used to obtain the operating status of the compressor and control the first gallium nitride switch tube and the second gallium nitride switch tube according to the operating status to reduce the current flowing through the freewheeling diode of the first gallium nitride switch tube and the freewheeling diode of the second gallium nitride switch tube during the startup of the compressor.

6. The external machine control circuit according to claim 5, characterized in that: The PFC circuit also includes a first inductor and a first capacitor, the second bridge arm includes a third switch tube and a fourth switch tube connected in series, one end of the AC power supply is connected to the connection point of the first gallium nitride switch tube and the second gallium nitride switch tube through the first inductor, the other end of the AC power supply is connected to the connection point of the third switch tube and the fourth switch tube, the first gallium nitride switch tube and the third switch tube are connected to one end of the first capacitor, and the second gallium nitride switch tube and the fourth switch tube are connected to the other end of the first capacitor.

7. The external machine control circuit according to claim 6, characterized in that: It also includes an input voltage sampling module connected to the first inductor, and an output end of the input voltage sampling module is connected to the MCU module.

8. The external machine control circuit according to claim 6, characterized in that: It also includes an input current sampling module connected to the first inductor, and an output end of the input current sampling module is connected to the MCU module.

9. The external machine control circuit according to claim 6, characterized in that: It also includes an output voltage sampling module connected to the first capacitor, and the output end of the output voltage sampling module is connected to the MCU module.

10. An operation control device, characterized in that: The invention comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the control method according to any one of claims 1 to 4.

11. An air conditioner, characterized in that: It includes the external machine control circuit according to any one of claims 5 to 9 or the operation control device according to claim 10.

12. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer-executable instructions, and the computer-executable instructions are used to enable a computer to execute the control method according to any one of claims 1 to 4.

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