Air conditioner

Abstract

The application discloses an air conditioner, which comprises an input power supply, a buffer starting module, a rectifier module, a switching power supply module, a detection module and a controller. When the air conditioner is powered on and in a standby state, the controller receives a voltage feedback signal, determines a corresponding actual DC bus voltage according to the voltage feedback signal, and controls the on-off state of a relay based on the comparison result of the actual DC bus voltage, a preset minimum working voltage threshold and a hysteresis voltage threshold, so as to switch the conduction path of the buffer starting module, thereby adjusting the power supply state of the input power supply to the rectifier module. The preset minimum working voltage threshold is the minimum input voltage required for the switching power supply module to work. In this way, the operating voltage range of the controller is effectively widened while the standby power consumption is significantly reduced. Moreover, without additional complex elements, the energy saving, reliability and wide voltage adaptability can be considered, thereby reducing the overall system cost.

Description

Technical Field

[0001] This invention relates to the field of air conditioner technology, and in particular to an air conditioner. Background Technology

[0002] In existing technologies, low-power processing in air conditioners mainly relies on two schemes. The first scheme is a normally closed control of the main control power relay, meaning that no control logic is set in the main control power circuit, and the relay always remains closed, causing the switching power supply in the main power supply to work continuously, converting AC power into low-voltage DC power to supply the standby circuit of the controller. Although this design is simple in structure and low in cost, the continuous power conversion process causes significant energy loss, significantly increasing power consumption in standby mode.

[0003] The second approach involves adding an auxiliary power supply to achieve relay disconnection control: when the air conditioner enters standby mode, the control system cuts off the main power supply via an additional relay drive circuit, while simultaneously providing additional power to the controller to supply the DC power required to maintain standby functionality. While this approach effectively reduces the no-load loss of the main power supply and decreases overall standby power consumption, and the control logic is relatively clear, it increases the system's hardware cost and circuit complexity due to the need for an additional auxiliary power supply module and related control circuits. Summary of the Invention

[0004] The present invention aims to at least solve one of the technical problems existing in the prior art. Therefore, the object of the present invention is to provide an air conditioner.

[0005] The present invention provides an air conditioner comprising: Input power supply, used to provide AC input voltage; A buffer start-up module, comprising a PTC (Positive Temperature Coefficient) resistor and a relay connected in parallel, wherein one end of the PTC resistor and one end of the relay are respectively connected to the input power supply; A rectifier module, one end of which is connected to the other end of the PTC resistor and the other end of the relay, is used to rectify the AC input voltage into a DC bus voltage; A switching power supply module, connected to the other end of the rectifier module, is used to convert the DC bus voltage into low-voltage DC power to power the controller and detection module. The detection module is connected to the other end of the rectifier module and is used to detect the DC bus voltage and generate a corresponding voltage feedback signal. The controller is connected to the relay, the switching power supply module, and the detection module, respectively. When the air conditioner is powered on and in standby mode, it receives the voltage feedback signal, determines the corresponding actual DC bus voltage based on the voltage feedback signal, and controls the on / off state of the relay based on the comparison result of the actual DC bus voltage with the preset minimum operating voltage threshold and the hysteresis voltage threshold, so as to switch the conduction path of the buffer start-up module, thereby adjusting the power supply state of the input power supply to the rectifier module. The preset minimum operating voltage threshold is the minimum input voltage required for the switching power supply module to operate.

[0006] According to an embodiment of the present invention, when the air conditioner is powered on and in standby mode, it receives a voltage feedback signal detected by a detection module, determines the corresponding actual DC bus voltage based on the voltage feedback signal, and compares the actual DC bus voltage with a preset minimum operating voltage threshold and a hysteresis voltage threshold. Based on the comparison result, it controls the on / off state of a relay to switch the conduction path of the buffer start-up module according to the closed or open state of the relay, thereby adjusting the power supply state of the input power supply to the rectifier module. This not only ensures that the controller can reliably power on and continue to operate under abnormal conditions such as grid voltage fluctuations or low input voltage, but also automatically switches the power supply mode according to voltage conditions in standby mode, significantly reducing standby power consumption while effectively widening the controller's operating voltage range. Furthermore, it achieves energy saving, reliability, and wide voltage adaptability without the need for additional complex components, thereby reducing the overall system cost.

[0007] In addition, the air conditioner according to embodiments of the present invention may also have the following additional technical features: Furthermore, before receiving the voltage feedback signal, the controller is configured to: control the relay to disconnect, so that the AC input voltage provided by the input power supply powers the rectifier module through the path of the PTC resistor, thereby establishing the DC bus voltage, so that the switching power supply module, the detection module and the controller are powered on and enter normal working state.

[0008] The above technical solution has the following advantages or beneficial effects: it not only achieves soft start and surge suppression, but also ensures that the system can still establish the necessary power supply voltage and complete the bootstrap power-on even when the main circuit where the relay is located is not conducting, thereby improving the reliability of the air conditioner system.

[0009] Furthermore, before controlling the on / off state of the relay based on the comparison results between the actual DC bus voltage and the preset minimum operating voltage threshold and hysteresis voltage threshold, the controller is configured to: control the relay to remain in the closed state for a first preset time.

[0010] The above technical solution has the following advantages or beneficial effects: it avoids misjudgment caused by power-on transient fluctuations, thereby improving the reliability of system startup and the accuracy of control.

[0011] Furthermore, when controlling the on / off state of the relay based on the comparison result between the actual DC bus voltage and the preset minimum operating voltage threshold and the hysteresis voltage threshold, the controller is configured to: obtain a first duration of relay closure; when the first duration is greater than the first preset time, and the actual DC bus voltage is less than or equal to the sum of the preset minimum operating voltage threshold and the hysteresis voltage threshold, determine whether the actual DC bus voltage is less than the preset minimum operating voltage threshold; if so, control the relay to remain closed.

[0012] The above technical solution has the following advantages or beneficial effects: it ensures that the input power supply is continuously supplied through the low-resistance path where the relay is located, avoids the voltage drop caused by the PTC resistor voltage drop, thereby ensuring the stable operation of the switching power supply module, maintaining the continuity of the controller's own power supply, and effectively preventing the system from malfunctioning during instantaneous voltage fluctuations or in the initial stage of power-on, thus improving the operational stability.

[0013] Furthermore, when controlling the on / off state of the relay based on the comparison result of the actual DC bus voltage with the preset minimum operating voltage threshold and the hysteresis voltage threshold, the controller is also configured to: when the first duration is greater than the first preset time, and the actual DC bus voltage is greater than the sum of the preset minimum operating voltage threshold and the hysteresis voltage threshold, control the relay to disconnect, and store the currently detected actual DC bus voltage as the maximum value of the bus voltage.

[0014] The above technical solution has the following advantages or beneficial effects: it significantly reduces the standby power consumption of the whole machine and the adaptability and reliability of the air conditioner in the environment of low grid voltage, thereby improving the accuracy of circuit control.

[0015] Furthermore, after controlling the relay to disconnect and storing the currently detected actual DC bus voltage as the maximum bus voltage, the controller is configured to: acquire a second duration of the relay disconnection and a new maximum bus voltage during the relay disconnection period; and control the on / off state of the relay based on the second duration and the new maximum bus voltage.

[0016] The above technical solution has the following advantages or beneficial effects: it can avoid frequent malfunctions, achieve dynamic adaptation to changes in the power grid while maintaining energy-saving effects, and improve the reliability and intelligence level of the system in complex power consumption environments.

[0017] Furthermore, when controlling the on / off state of the relay based on the second duration and the new maximum bus voltage, the controller is configured to: determine the difference between the new maximum bus voltage and the hysteresis voltage threshold; and control the relay to close when the new maximum bus voltage is less than the difference and the second duration is greater than a second preset time.

[0018] The above-mentioned technical solution has the following advantages or beneficial effects: it can effectively avoid malfunctions caused by instantaneous voltage fluctuations or brief power outages, prevent frequent switching of relays, and improve the system's anti-interference capability and operational reliability. Simultaneously, by dynamically adjusting the voltage threshold for restoring closure based on the new maximum bus voltage, the system can adapt to different power grid environments, achieving precise power management and maximizing energy savings while ensuring stability.

[0019] Furthermore, when the maximum value of the new bus voltage is less than the difference and the second duration is greater than the second preset time, and the controller controls the relay to close, the controller is configured to: obtain the third duration of the relay closure; and control the relay to open after the third duration reaches the third preset time.

[0020] The above technical solution has the following advantages or beneficial effects: it can realize the automatic reset function after the relay is closed, avoid the extra energy consumption caused by the relay being closed for a long time, enable the system to intelligently recover and save energy again after dealing with voltage fluctuations, thus ensuring the reliability of operation under low voltage conditions, while also taking into account the energy efficiency optimization of long standby, and improving the air conditioner's adaptability and comprehensive performance in complex power grid environments.

[0021] Furthermore, when acquiring a new maximum bus voltage during the relay disconnection period, the controller is configured to: acquire a first voltage feedback signal during the relay disconnection period; determine a first actual DC bus voltage based on the first voltage feedback signal; and update the first actual DC bus voltage to the new maximum bus voltage and store it when the first actual DC bus voltage is greater than the maximum bus voltage.

[0022] The above technical solution has the following advantages or beneficial effects: it realizes the adaptive learning capability of the power supply environment, enhances the intelligence and reliability of the control logic, and avoids misjudgment caused by fixed thresholds.

[0023] Furthermore, when controlling the on / off state of the relay based on the comparison results of the actual DC bus voltage with the preset minimum operating voltage threshold and hysteresis voltage threshold, the controller is configured to: acquire the actual DC bus voltage of the relay during the off or closed period in real time, and when it is detected that the current actual DC bus voltage is greater than the stored maximum bus voltage, update the current actual DC bus voltage to the latest maximum bus voltage and store it.

[0024] The above technical solution has the following advantages or beneficial effects: it realizes intelligent tracking of power supply status, improves the accuracy of relay on / off control and the stability of system operation, and enhances the adaptability of standby energy-saving strategy.

[0025] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0026] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of the structure of an air conditioner according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the controller according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of an air conditioner according to another embodiment of the present invention; Figure 4 This is a circuit diagram of an air conditioner according to an embodiment of the present invention; Figure 5 This is a flowchart of an air conditioner control method according to an embodiment of the present invention; Figure 6 This is a flowchart of controlling the on / off state of a relay according to an embodiment of the present invention; Figure 7 This is a flowchart of controlling the on / off state of a relay according to another embodiment of the present invention; Figure 8 This is a flowchart of determining a new maximum bus voltage according to an embodiment of the present invention. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] In the description of this invention, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0029] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0030] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0031] This invention provides an air conditioner 10, with reference to... Figure 1 The air conditioner 10 includes a refrigeration system for exchanging heat with indoor air to meet cooling or heating needs.

[0032] The refrigeration system includes a compressor, a condenser, an electronic expansion valve, and an evaporator. In this invention, the air conditioner 10 performs a refrigeration cycle by using the compressor, condenser, electronic expansion valve, and evaporator. The refrigeration cycle includes a series of processes involving compression, condensation, expansion, and evaporation, and supplies refrigerant to the conditioned and heat-exchanged air.

[0033] The compressor compresses refrigerant gas under high temperature and pressure and discharges the compressed refrigerant gas. The discharged refrigerant gas flows into the condenser. The condenser condenses the compressed refrigerant into a liquid phase, and the heat is released to the surrounding environment through the condensation process.

[0034] The electronic expansion valve expands the high-temperature, high-pressure liquid refrigerant condensed in the condenser into a low-pressure liquid refrigerant. The evaporator evaporates the refrigerant that has expanded in the electronic expansion valve and returns the low-temperature, low-pressure refrigerant gas to the compressor.

[0035] The evaporator achieves a cooling effect by utilizing the latent heat of refrigerant evaporation to exchange heat with the material being cooled. Throughout the cycle, the air conditioner 10 can regulate the temperature of the indoor space.

[0036] The outdoor unit 2 of the air conditioner 10 refers to the part of the refrigeration cycle that includes the compressor and the outdoor heat exchanger. The indoor unit 1 of the air conditioner 10 includes the indoor heat exchanger, and an electronic expansion valve can be provided in either the indoor unit 1 or the outdoor unit 2.

[0037] The indoor and outdoor heat exchangers are used as condensers or evaporators. When the indoor heat exchanger is used as a condenser, the air conditioner 10 is used as a heater in heating mode, and when the indoor heat exchanger is used as an evaporator, the air conditioner 10 is used as a cooler in cooling mode.

[0038] The air conditioner 10 of this invention includes an indoor unit 1 and an outdoor unit 2, which can be configured as an integrated unit or a split unit. The indoor unit 1 can be configured as a wall-mounted unit, a ceiling-mounted unit, a ducted unit, etc., and the indoor unit 1 is installed on the top of the room.

[0039] Reference Figure 1 Taking indoor wall-mounted units as an example, indoor wall-mounted units are usually installed on indoor walls or other locations. For example, indoor cabinet units (not shown in the figure) are also a type of indoor unit 1.

[0040] Taking a split-type air conditioner as an example, the air conditioner 10 includes an indoor unit 1 and an outdoor unit 2. The outdoor unit 2 is usually installed outdoors and is used for heat exchange in the indoor environment.

[0041] Furthermore, as shown in the figure, the air conditioner 10 includes a controller 71 to control the operation of various components within the air conditioner 10, enabling each component to perform its predetermined functions. The air conditioner 10 also includes a control device 200, which, for example, is a remote control. This remote control has the function of communicating with the controller 71 using, for example, infrared or other communication methods. The remote control allows the user to perform various controls on the air conditioner 10, enabling interaction between the user and the air conditioner 10.

[0042] In this embodiment of the invention, the indoor unit 1 of the air conditioner 10 is located at the top or upper part of the room. Generally, the installation height of the indoor unit 1 is higher than the user's activity area. The indoor unit 1 includes a return air vent and an air outlet that communicate with the room. Indoor air passes through the return air vent into the indoor unit 1 and flows back into the room through the air outlet.

[0043] The refrigerant circulation loop in this invention allows the refrigerant to circulate within a circuit consisting of a compressor, condenser, electronic expansion valve, and evaporator. One of the condenser and evaporator is an outdoor heat exchanger, and the other is an indoor heat exchanger. The indoor heat exchanger exchanges heat with the air inside the indoor unit 1, and the outdoor unit 2 heat exchanger exchanges heat with the air inside the outdoor unit 2, thereby fulfilling the cooling or heating requirements of the air conditioner 10.

[0044] The indoor unit 1 also includes an indoor fan, which is located near the return air vent or the air outlet of the indoor heat exchanger. It is used to deliver the heat-exchanged air to the room. The indoor fan has multiple speed settings to change the airflow speed at the air outlet.

[0045] An air guide plate is installed at the air outlet. By changing its relative rotation angle with the air outlet, the air guide plate adjusts the direction of the airflow through the air outlet, thereby affecting the stratification of indoor air temperature.

[0046] In the embodiment shown in this invention, the air conditioner 10 further includes a controller 71, which is a device that can generate operation control signals according to instruction operation codes and timing signals to instruct the air conditioner 10 to execute control commands. For example, in response to a power-on or power-off command issued by a user, the controller 71 can perform an operation related to the object selected by the power-on or power-off command.

[0047] This invention also provides a hardware structure diagram of the controller 71, as shown in the embodiment. Figure 2 As shown, the controller 71 includes a processor 83, and optionally, a memory 82 and a communication interface 84 connected to the processor 83. The processor 83, memory 82, and communication interface 84 are connected via a bus 81.

[0048] Processor 83 can be a central processing unit (CPU), a general-purpose processor (NP), a network processor (NP), a digital signal processor (DSP), a microprocessor (Microcontroller 718), a programmable logic device (PLD), or any combination thereof. Processor 83 can also be any other device with processing capabilities, such as a circuit, device, or software module. Processor 83 can also include multiple CPUs, and processor 83 can be a single-core processor 83 or a multi-core processor 83. Here, processor 83 can refer to one or more devices, circuits, or processing cores used for processing data (e.g., computer program instructions).

[0049] The memory 82 can be a read-only memory (ROM) or other type of static storage device capable of storing static information and instructions, a random access memory (RAM) or other type of dynamic storage device capable of storing information and instructions, or an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD ROM) or other optical disc storage, optical disc storage (including compressed optical discs, laser discs, optical discs, digital universal optical discs, Blu-ray discs, etc.), a magnetic disk storage medium or other magnetic storage device, or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer. This embodiment of the invention does not impose any limitations on this. The memory 82 can exist independently or be integrated with the processor 83. The memory 82 may contain computer program code. The processor 83 is used to execute the computer program code stored in the memory 82, thereby implementing the air conditioner control method provided in this embodiment of the invention.

[0050] The communication interface 84 can be used to communicate with other devices or communication networks (such as Ethernet, radio access network (RAN), wireless local area networks (WLAN), etc.). The communication interface 84 can be a module, circuit, transceiver, or any device capable of communication.

[0051] Bus 81 can be a Peripheral Component Interconnect (PCI) bus 81 or an Extended Industry Standard Architecture (EISA) bus 81, etc. Bus 81 can be divided into address bus 81, data bus 81, control bus 81, etc. For ease of representation, Figure 2 The bus is represented by only one thick line, but this does not mean that there is only one bus 81 or one type of bus 81.

[0052] The following is for reference. Figure 3 An air conditioner according to an embodiment of the present invention is described.

[0053] Figure 3 This is a schematic diagram of the structure of an air conditioner according to an embodiment of the present invention. Figure 3 As shown, an air conditioner 10 includes: an input power supply 11, a buffer start-up module 12, a rectifier module 13, a switching power supply module 14, a detection module 15, and a controller 71.

[0054] Among them, such as Figure 4 As shown, the input power supply 11 provides AC input voltage; the buffer start-up module 12 includes a PTC resistor and a relay K1 connected in parallel, with one end of the PTC resistor and one end of the relay K1 respectively connected to the input power supply 11; one end of the rectifier module 13 is connected to the other end of the PTC resistor and the other end of the relay K1 respectively, for rectifying the AC input voltage into a DC bus voltage; the switching power supply module 14 is connected to the other end of the rectifier module 13, for converting the DC bus voltage into low-voltage DC power to power the controller 71 and the detection module 15; the detection module 15 is connected to the other end of the rectifier module 13, for detecting the DC bus voltage and generating a corresponding voltage feedback signal.

[0055] The controller 71 is connected to the relay K1, the switching power supply module 14, and the detection module 15 respectively. When the air conditioner 10 is powered on and in standby mode, it receives a voltage feedback signal, determines the corresponding actual DC bus voltage based on the voltage feedback signal, and controls the on / off state of the relay K1 based on the comparison result of the actual DC bus voltage with the preset minimum operating voltage threshold and the hysteresis voltage threshold, so as to switch the conduction path of the buffer start module 12, thereby adjusting the power supply state of the input power supply 11 to the rectifier module 13. The preset minimum operating voltage threshold is the minimum input voltage required for the switching power supply module 14 to work.

[0056] In an embodiment, such as Figure 4As shown, the input power supply 11 provides AC input voltage to the entire circuit. This AC input voltage is connected to the buffer start-up module 12, which consists of a PTC resistor and a relay K1 connected in parallel. The PTC resistor has a positive temperature coefficient and a high cold-state resistance, for example, around 100Ω, which effectively suppresses surge current during initial power-on, preventing damage to the rectifier bridge and electrolytic capacitors due to instantaneous high current. The relay K1 acts as the main circuit switch, and its on / off state is dynamically controlled by the controller 71 according to the system operating status. The rectifier module 13 rectifies the AC input voltage from the buffer start-up module 12 into a DC bus voltage.

[0057] One end of the switching power supply module 14 is connected to the other end of the rectifier module 13. It can receive the DC bus voltage output by the rectifier module 13 and convert the DC bus voltage into low-voltage DC (such as 5V or 3.3V) to provide a stable working power supply for the controller 71 and the detection module 15, ensuring the continuous operation of the system.

[0058] The detection module 15 is connected to the other end of the rectifier module 13. It can sample the DC bus voltage at the other end of the rectifier module 13 in real time and generate a voltage feedback signal proportional to it, which is sent to the controller 71 to ensure that the controller 71 can accurately obtain the voltage information of the input power supply 11 within the safe voltage range.

[0059] After receiving the voltage feedback signal, the controller 71 reads the signal, for example, through analog-to-digital conversion, and calculates the corresponding actual DC bus voltage according to a preset voltage division ratio. This enables real-time monitoring of the input power supply 11 voltage, allowing the controller 71 to dynamically grasp the power supply status. Based on this, the controller 71 compares the actual DC bus voltage value with a preset minimum operating voltage threshold and a hysteresis voltage threshold. The preset minimum operating voltage threshold refers to the minimum input voltage (e.g., 60V) required for the switching power supply module 14 to operate continuously and stably. If the DC bus voltage is lower than this value, the switching power supply module 14 may fail to start normally or its output may be unstable, causing the controller 71 and core components such as the detection module 15 to lose power. The hysteresis voltage threshold is introduced to prevent the system from oscillating frequently near the critical voltage, thus improving control stability.

[0060] The controller 71, based on the comparison results, dynamically controls the on / off state of relay K1. For example, if the comparison results indicate that the current power supply conditions are good and energy-saving operation is possible, the controller immediately controls relay K1 to disconnect. At this time, the conduction path of the buffer start-up module 12 switches to the path formed by the PTC resistor, and the input power supply 11 continuously supplies power to the rectifier module 13 through the PTC resistor. Since the load current is small in standby mode, the voltage drop across the PTC resistor is limited, which can still maintain sufficient DC bus voltage to ensure stable operation of the switching power supply module 14. In this state, the drive coil of relay K1 no longer consumes electrical energy (e.g., power consumption of approximately 0.96W), thereby effectively reducing the overall standby power consumption and achieving the energy-saving goal.

[0061] When the comparison result indicates insufficient current power supply capacity, the controller 71 re-closes relay K1, switching to low-resistance power supply. That is, the conduction path is switched from the path containing the PTC resistor to the low-resistance path containing relay K1. This switching eliminates the voltage drop and power loss across the PTC resistor, allowing more input voltage to be effectively transferred to the rectifier module 13, thereby increasing the DC bus voltage and ensuring it remains above the minimum operating voltage requirement of the switching power supply module 14. Through this mechanism, the controller 71 achieves precise control over the conduction path of the buffer start-up module 12. This not only ensures reliable power-on and continuous operation under abnormal conditions such as grid voltage fluctuations or low input voltage, but also allows the controller 71 to automatically switch power supply modes based on voltage conditions in standby mode. This significantly reduces standby power consumption while effectively expanding the operating voltage range of the controller 71. Furthermore, it achieves energy efficiency, reliability, and wide voltage adaptability without the need for additional complex components, thus reducing the overall system cost.

[0062] In one embodiment of the present invention, before receiving the voltage feedback signal, the controller 71 is configured to: control the relay K1 to open, so that the AC input voltage provided by the input power supply 11 supplies power to the rectifier module 13 through the path of the PTC resistor to establish the DC bus voltage, thereby powering on the switching power supply module 14, the detection module 15 and the controller 71 and putting them into normal operation.

[0063] In this embodiment, before receiving the voltage feedback signal, the controller 71 is configured to perform the power-on initialization phase power-up setup process. Specifically, when the air conditioner 10 is first powered on or re-powered, the controller 71 has not yet received a stable power supply, and its internal logic is in a reset or standby state. At this time, the controller 71 controls the relay K1 to be in the open state, so that the AC input voltage provided by the input power supply 11 flows to the rectifier module 13 through the path formed by the PTC resistor.

[0064] As current continuously flows through the PTC resistor to supply power to the rectifier module 13, the AC input voltage is converted into a DC bus voltage by the rectifier module 13, and the filter electrolytic capacitors within the rectifier module 13 are charged, gradually establishing a stable DC bus voltage. When the DC bus voltage rises above the start-up threshold of the switching power supply module 14, the switching power supply module 14 begins normal operation, converting it into low-voltage DC power to supply power to the detection module 15 and the controller 71 in sequence.

[0065] Once the controller 71 receives a stable power supply, the power-on process is complete, and it enters a normal operating state. At this time, its internal analog-to-digital converter, control logic unit, and other functional modules are activated, enabling them to receive and process voltage feedback signals from the detection module 15. Therefore, this initial stage, by controlling the relay K1 to disconnect and relying on the PTC resistor for power supply, not only achieves soft start and surge suppression but also ensures that the system can still establish the necessary power supply voltage and complete bootstrapping power-on even when the main path where relay K1 is located is not conducting, thereby improving the reliability of the air conditioner 10 system.

[0066] In one embodiment of the present invention, before controlling the on / off state of relay K1 based on the comparison result between the actual DC bus voltage and the preset minimum operating voltage threshold and hysteresis voltage threshold, the controller 71 is configured to control relay K1 to remain in the closed state for a first preset time.

[0067] In this embodiment, after the system is powered on and operating normally, relay K1 is first kept closed for a first preset time. This ensures that after relay K1 is closed, the input power supply 11 provides stable power to the rectifier module 13 through the low-resistance path of relay K1, allowing the DC bus voltage to fully establish and enter a steady state. During this period, the switching power supply module 14, the detection module 15, and the controller 71 complete their own power-on initialization, and the voltage feedback signal tends to stabilize, avoiding misjudgments caused by transient fluctuations during power-on. After the first preset time has elapsed, the controller 71 performs logical judgment based on the stable voltage feedback signal and initiates the intelligent on / off control of relay K1, thereby improving the reliability and accuracy of system startup.

[0068] In one embodiment of the present invention, when controlling the on / off state of relay K1 based on the comparison result of the actual DC bus voltage with the preset minimum operating voltage threshold and the hysteresis voltage threshold, the controller 71 is configured to: obtain the first duration of relay K1 being closed; when the first duration is greater than the first preset time, and the actual DC bus voltage is less than or equal to the sum of the preset minimum operating voltage threshold and the hysteresis voltage threshold, determine whether the actual DC bus voltage is less than the preset minimum operating voltage threshold; if so, control relay K1 to remain closed.

[0069] For example, the actual DC bus voltage is denoted as Vdc, the preset minimum operating voltage threshold is denoted as V_low_on and V_low_on=60V, and the hysteresis voltage threshold is denoted as V_delta and V_delta=20V.

[0070] In this embodiment, the controller 71 first obtains the duration of the current closed state of relay K1, which is recorded as the first duration. Only when the first duration exceeds a first preset time is the subsequent voltage judgment process allowed, so as to avoid misjudgment when relay K1 has just closed and the system has not yet stabilized.

[0071] Specifically, when the first duration is greater than a first preset time, and the detected actual DC bus voltage Vdc is less than or equal to the sum of the preset minimum operating voltage threshold V_low_on and the hysteresis voltage threshold V_delta, i.e., Vdc... When V_low_on + V_delta, controller 71 further determines whether Vdc is lower than V_low_on. For example, if V_low_on is set to 60V and V_delta to 20V, then the sum of the preset minimum operating voltage threshold V_low_on and the hysteresis voltage threshold V_delta is 80V. If Vdc If the voltage is 80V and Vdc < 60V, it indicates that the current DC bus voltage is approaching or below the minimum input voltage required for the switching power supply module 14 to maintain normal operation, posing a risk of system power failure. At this time, the controller 71 immediately controls the relay K1 to remain closed, ensuring that the input power supply 11 continues to supply power through the low-resistance path where the relay K1 is located, avoiding further voltage drop due to the voltage drop of the PTC resistor, thereby ensuring the stable operation of the switching power supply module 14 and maintaining the continuity of the power supply to the controller 71 itself. This effectively prevents the system from malfunctioning during instantaneous voltage fluctuations or in the initial power-on period, and improves operational stability.

[0072] In one embodiment of the present invention, when controlling the on / off state of relay K1 based on the comparison result of the actual DC bus voltage with the preset minimum operating voltage threshold and the hysteresis voltage threshold, the controller 71 is further configured to: when the first duration is greater than the first preset time and the actual DC bus voltage is greater than the sum of the preset minimum operating voltage threshold and the hysteresis voltage threshold, control relay K1 to open and store the currently detected actual DC bus voltage as the maximum value of the bus voltage.

[0073] In this embodiment, when the controller 71 detects that the first duration of the relay K1's closure has exceeded the first preset time, it indicates that the system has completed the power-on stabilization process and entered normal operation. At this time, if the actual DC bus voltage Vdc is detected to be greater than the sum of the preset minimum operating voltage threshold V_low_on and the hysteresis voltage threshold V_delta, i.e., Vdc > V_low_on + V_delta = 80V, it indicates that the current power supply is sufficient. Under this condition, the controller 71 determines that the system can safely enter the energy-saving mode, and then controls the relay K1 to open, switching the current path of the input power supply 11 to the current-limiting path composed of the PTC resistor.

[0074] For example, the PTC resistor has a cold resistance of 100Ω, and the downstream load current is approximately 0.1A in standby mode. When relay K1 is disconnected, current flows through the PTC resistor, and the voltage drop across it is 100Ω × 0.1A = 10V. Because the downstream load is relatively light when the air conditioner 10 is in standby mode, the current flowing through the PTC resistor is small (e.g., 0.1A), and the resulting voltage drop is limited (e.g., 100Ω × 0.1A = 10V). The DC bus voltage output by the rectifier module 13 can still be maintained above the minimum operating voltage of the switching power supply module 14, ensuring continuous and stable system operation.

[0075] When the actual DC bus voltage is higher than 80V, the control relay K1 is disconnected, and the operation of the switching power supply module 14 can be maintained by charging the rectified electrolytic capacitor with the PTC resistor alone. For example, when the relay K1 is working, it requires a working voltage and current of 12V and 80mA, which will generate 0.96W of standby power consumption. However, after the control relay K1 is disconnected, its drive coil no longer consumes drive power (i.e., 12V×80mA=0.96W), and this part of the standby power consumption is completely eliminated, thereby significantly reducing the standby power consumption of the whole machine.

[0076] To ensure the normal operation of the switching power supply module 14, the DC bus voltage after rectification and passing through the PTC resistor must be at least 60V. However, considering hysteresis control, it actually needs to be maintained above 80V. Since the standby load is relatively light, the DC bus voltage after rectification and filtering is close to the peak value of the AC input voltage. Therefore, the minimum effective value of the required AC input voltage is: 10V + (80V / √2) ≈ 10V + 56.58V = 66.58V.

[0077] Furthermore, when relay K1 is closed, the PTC resistor is short-circuited, resulting in no additional voltage drop. At this time, as long as the rectified DC bus voltage is greater than or equal to 80V, the corresponding minimum effective value of the AC input voltage is: 80V / √2≈56.58V.

[0078] It can be seen that by closing relay K1 under low voltage conditions, the system can still operate stably when the AC input voltage is as low as about 56.58V. Compared with the lower limit of 66.58V of the PTC path, the minimum AC voltage that can be operated is widened by 10V, which significantly improves the adaptability and reliability of the air conditioner in the environment of low grid voltage.

[0079] Simultaneously, while executing the relay K1 disconnection operation, the controller 71 records and stores the currently detected actual DC bus voltage value as the maximum bus voltage. This value represents the highest voltage level reached by the system during the most recent main path conduction period, serving as a benchmark for subsequent voltage drop judgment. Through this mechanism, the system not only achieves automatic energy saving when the power supply is good, but also establishes a dynamic voltage reference, providing a reliable basis for subsequent judgments on whether the relay needs to be re-closed (e.g., when the grid voltage drops to a critical value), thereby improving the accuracy of circuit control.

[0080] In one embodiment of the present invention, after controlling relay K1 to disconnect and storing the currently detected actual DC bus voltage as the maximum bus voltage, controller 71 is configured to: acquire a second duration of relay K1 disconnection and a new maximum bus voltage during the period of relay K1 disconnection; and control the on / off state of relay K1 according to the second duration and the new maximum bus voltage.

[0081] In this embodiment, the controller 71 begins the second duration of the timer relay K1 being disconnected, while simultaneously continuing to sample the DC bus voltage in real time via the detection module 15 and updating the system status based on the voltage feedback signal. During this period, the controller 71 dynamically records the new maximum bus voltage value that occurs during the disconnection phase. This new maximum bus voltage value may be higher or lower than the initially stored maximum bus voltage value due to grid fluctuations.

[0082] The controller 71 controls the on / off state of the relay K1 based on the second duration and the new maximum value of the bus voltage to avoid frequent malfunctions. This achieves dynamic adaptation to grid changes while maintaining energy-saving effects, and improves the reliability and intelligence of the system in complex power environments.

[0083] In one embodiment of the present invention, when controlling the on / off state of relay K1 according to a second duration and a new maximum bus voltage, controller 71 is configured to: determine the difference between the new maximum bus voltage and a hysteresis voltage threshold; and control relay K1 to close when the new maximum bus voltage is less than the difference and the second duration is greater than a second preset time.

[0084] In this embodiment, the controller 71 first calculates the difference between the new maximum bus voltage and the preset hysteresis voltage threshold V_delta. For example, the new maximum bus voltage is denoted as V1, and the difference is denoted as V_delta. ,but =V1-V_delta.

[0085] When controller 71 detects that the actual DC bus voltage Vdc is lower than this difference Meanwhile, the second duration of relay K1 being open has exceeded the second preset time, indicating that the air conditioner 10 has been operating in PTC resistor power supply mode for a sufficient period of time, and the mains voltage has remained low to a level that could threaten the normal operation of the switching power supply module 14. At this time, the controller 71 determines that continuing to maintain the open state of relay K1 poses a risk of power loss, and then controls relay K1 to close, switching the power supply path from the PTC resistor path back to the low-resistance path where relay K1 is located, eliminating the voltage drop across the PTC resistor, increasing the DC bus voltage output by the rectifier module 13, and ensuring the stable operation of the switching power supply module 14.

[0086] This effectively avoids malfunctions caused by instantaneous voltage fluctuations or brief power outages, prevents frequent switching of relay K1, and improves the system's anti-interference capability and operational reliability. Simultaneously, by dynamically adjusting the voltage threshold for restoring closure based on the new maximum bus voltage, the system can adapt to different power grid environments, achieving precise power management and maximizing energy savings while ensuring stability.

[0087] In one embodiment of the present invention, when the maximum value of the new bus voltage is less than the difference and the second duration is greater than the second preset time, the controller 71 is configured to: obtain the third duration of the relay K1 closing; and after the third duration reaches the third preset time, control the relay K1 to open.

[0088] In this embodiment, when the controller 71 determines that the new maximum bus voltage is less than the difference between it and the preset hysteresis voltage threshold (i.e., the actual DC bus voltage has fallen back to the safe voltage range) and the disconnection time of relay K1 has exceeded the second preset time, in order to restore the reliability of the system power supply, the controller 71 controls relay K1 to close, switching back to the low-resistance conduction path to increase the DC bus voltage and ensure the stable operation of the switching power supply module 14. Furthermore, to prevent the system from being in a high-power state for an extended period and to maintain energy-saving capabilities after a brief rise in the grid voltage, the controller 71 starts timing the third duration of relay K1's closure after the relay K1 closes.

[0089] When the third duration reaches the third preset time, the controller 71 determines that the system has been sufficiently stable under the power supply of the path where relay K1 is located, and the mains voltage has been maintained at a high level for a period of time, thus meeting the conditions for re-entering the energy-saving mode. At this time, the controller 71 controls relay K1 to disconnect again, switching the power supply path back to the PTC resistor path. Under the premise of ensuring that the system can still operate normally, the power consumption of the relay K1 drive coil is eliminated, for example, about 0.96W, and the system re-enters the low-power standby state.

[0090] This enables the automatic reset function after relay K1 is closed, avoiding the extra energy consumption caused by relay K1 being closed for a long time. It allows the system to intelligently recover and save energy again after dealing with voltage fluctuations, thus ensuring the reliability of operation under low voltage conditions and taking into account the energy efficiency optimization during long standby. This improves the adaptability and overall performance of air conditioner 10 in complex power grid environments.

[0091] In one embodiment of the present invention, when obtaining a new maximum bus voltage during the period when relay K1 is disconnected, controller 71 is configured to: obtain a first voltage feedback signal during the period when relay K1 is disconnected; determine a first actual DC bus voltage based on the first voltage feedback signal; and update the first actual DC bus voltage to the new maximum bus voltage and store it when the first actual DC bus voltage is greater than the maximum bus voltage.

[0092] In this embodiment, after the relay K1 is disconnected, the controller 71 acquires the first voltage feedback signal provided by the detection module 15 in real time. The controller 71 calculates the corresponding first actual DC bus voltage value based on the first voltage feedback signal and the preset voltage division ratio.

[0093] Subsequently, the controller 71 compares the first actual DC bus voltage detected in real time with the currently stored maximum bus voltage (i.e., the highest voltage recorded during the last closing or previous opening of relay K1). If the detected first actual DC bus voltage is higher than the stored value, it indicates that the current grid voltage has rebounded and the system is in a better power supply state. At this time, the controller 71 immediately updates the higher voltage value as the new maximum bus voltage and stores it. In this way, the system achieves adaptive learning capability to the power supply environment, enhances the intelligence and reliability of the control logic, and avoids misjudgments caused by fixed thresholds.

[0094] In one embodiment of the present invention, when controlling the on / off state of relay K1 based on the comparison result of the actual DC bus voltage with the preset minimum operating voltage threshold and hysteresis voltage threshold, the controller 71 is configured to: acquire the actual DC bus voltage of relay K1 during the off or closed period in real time, and when it is detected that the current actual DC bus voltage is greater than the stored maximum bus voltage, update the current actual DC bus voltage to the latest maximum bus voltage and store it.

[0095] In this embodiment, when controlling the on / off state of relay K1, controller 71 continuously acquires the actual DC bus voltage of relay K1 during its closed or open state in real time. Through the voltage feedback signal from detection module 15, controller 71 continuously compares the current actual DC bus voltage with the stored maximum bus voltage. Once it detects that the current actual DC bus voltage is higher than the stored maximum bus voltage, it immediately updates it to the latest maximum bus voltage and stores it. This ensures that the system always uses the most recently observed highest voltage as a reference, dynamically adapting to changes in the power grid and avoiding misjudgments due to voltage fluctuations. Through real-time voltage monitoring and automatic updates, controller 71 achieves intelligent tracking of the power supply status, improving the accuracy of relay K1 on / off control and the stability of system operation, while also enhancing the adaptability of standby energy-saving strategies.

[0096] According to an embodiment of the present invention, when the air conditioner 10 is powered on and in standby mode, the controller 71 receives a voltage feedback signal detected by the detection module 15, determines the corresponding actual DC bus voltage based on the voltage feedback signal, and compares the actual DC bus voltage with a preset minimum operating voltage threshold and a hysteresis voltage threshold. Based on the comparison result, the controller controls the on / off state of the relay K1 to switch the conduction path of the buffer start module 12 according to the closed or open state of the relay K1, thereby adjusting the power supply state of the input power supply 11 to the rectifier module 13. This not only ensures that the controller 71 can reliably power on and continue to operate under abnormal conditions such as grid voltage fluctuations or low input voltage, but also automatically switches the power supply mode according to voltage conditions in standby mode, significantly reducing standby power consumption while effectively widening the operating voltage range of the controller 71. Furthermore, without adding additional complex components, it can balance energy saving, reliability, and wide voltage adaptability, thereby reducing the overall system cost.

[0097] The following is for reference. Figures 5-8 This invention describes a control method for an air conditioner according to an embodiment of the present invention.

[0098] like Figure 5 As shown, the control method of the air conditioner in this embodiment of the invention includes at least step S1.

[0099] Step S1: When the air conditioner is powered on and in standby mode, a voltage feedback signal is received, the corresponding actual DC bus voltage is determined according to the voltage feedback signal, and the on / off state of the relay is controlled based on the comparison result of the actual DC bus voltage with the preset minimum operating voltage threshold and the hysteresis voltage threshold, so as to switch the conduction path of the buffer start module, thereby adjusting the power supply state of the input power supply to the rectifier module. The preset minimum operating voltage threshold is the minimum input voltage required for the switching power supply module to work.

[0100] In one embodiment of the present invention, before receiving the voltage feedback signal, the method includes: controlling the relay to disconnect, so that the AC input voltage provided by the input power supply supplies power to the rectifier module through the path of the PTC resistor to establish the DC bus voltage, thereby powering on the switching power supply module, the detection module and the controller and putting them into normal operation.

[0101] In one embodiment of the present invention, before controlling the on / off state of the relay based on the comparison result of the actual DC bus voltage with the preset minimum operating voltage threshold and the hysteresis voltage threshold, the method includes: controlling the relay to remain in a closed state for a first preset time.

[0102] In one embodiment of the present invention, such as Figure 6 As shown, when controlling the on / off state of the relay based on the comparison results of the actual DC bus voltage with the preset minimum operating voltage threshold and the hysteresis voltage threshold, the following steps are included: obtaining the first duration of the relay closure; when the first duration is greater than the first preset time, and the actual DC bus voltage is less than or equal to the sum of the preset minimum operating voltage threshold and the hysteresis voltage threshold, determining whether the actual DC bus voltage is less than the preset minimum operating voltage threshold; if so, controlling the relay to remain closed.

[0103] In one embodiment of the present invention, such as Figure 6 As shown, when controlling the on / off state of the relay based on the comparison results of the actual DC bus voltage with the preset minimum operating voltage threshold and the hysteresis voltage threshold, the following steps are taken: when the first duration is greater than the first preset time and the actual DC bus voltage is greater than the sum of the preset minimum operating voltage threshold and the hysteresis voltage threshold, the relay is controlled to open, and the currently detected actual DC bus voltage is stored as the maximum value of the bus voltage.

[0104] In one embodiment of the present invention, such as Figure 7 As shown, after controlling the relay to disconnect and storing the currently detected actual DC bus voltage as the maximum bus voltage, the process includes: obtaining the second duration of the relay disconnection and the new maximum bus voltage during the relay disconnection period; and controlling the on / off state of the relay based on the second duration and the new maximum bus voltage.

[0105] In one embodiment of the present invention, such as Figure 7 As shown, when controlling the on / off state of the relay based on the second duration and the new maximum value of the bus voltage, the method includes: determining the difference between the new maximum value of the bus voltage and the hysteresis voltage threshold; and controlling the relay to close when the new maximum value of the bus voltage is less than the difference and the second duration is greater than the second preset time.

[0106] In one embodiment of the present invention, such as Figure 7 As shown, when the maximum value of the new bus voltage is less than the difference and the second duration is greater than the second preset time, when the relay is closed, the following steps are taken: obtaining the third duration of the relay closure; and controlling the relay to open after the third duration reaches the third preset time.

[0107] In one embodiment of the present invention, such as Figure 8 As shown, when obtaining the new maximum value of the bus voltage during the relay disconnection period, the process includes: obtaining a first voltage feedback signal during the relay disconnection period; determining a first actual DC bus voltage based on the first voltage feedback signal; and updating the first actual DC bus voltage to the new maximum value of the bus voltage and storing it when the first actual DC bus voltage is greater than the maximum value of the bus voltage.

[0108] In one embodiment of the present invention, when controlling the on / off state of a relay based on a comparison between the actual DC bus voltage and a preset minimum operating voltage threshold and a hysteresis voltage threshold, the method includes: acquiring the actual DC bus voltage of the relay during the off or closed period in real time, and updating the current actual DC bus voltage to the latest maximum bus voltage and storing it when it is detected that the current actual DC bus voltage is greater than the stored maximum bus voltage.

[0109] According to the air conditioner control method of this embodiment, when the air conditioner is powered on and in standby mode, a detected voltage feedback signal is received. The actual DC bus voltage corresponding to the voltage feedback signal is determined, and the actual DC bus voltage is compared with a preset minimum operating voltage threshold and a hysteresis voltage threshold. Based on the comparison result, the on / off state of a relay is controlled. The conduction path of the buffer start-up module is switched according to the closed or open state of the relay, thereby adjusting the power supply state of the input power to the rectifier module. This not only ensures that the controller can reliably power on and continuously operate under abnormal conditions such as grid voltage fluctuations or low input voltage, but also automatically switches the power supply mode according to voltage conditions in standby mode. This significantly reduces standby power consumption while effectively widening the controller's operating voltage range. Furthermore, it achieves energy saving, reliability, and wide voltage adaptability without the need for additional complex components, thereby reducing the overall system cost.

[0110] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0111] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. An air conditioner, characterized in that, include: Input power supply, used to provide AC input voltage; A buffer start module, comprising a PTC resistor and a relay connected in parallel, wherein one end of the PTC resistor and one end of the relay are respectively connected to the input power supply; A rectifier module, one end of which is connected to the other end of the PTC resistor and the other end of the relay, is used to rectify the AC input voltage into a DC bus voltage; A switching power supply module, connected to the other end of the rectifier module, is used to convert the DC bus voltage into low-voltage DC power to power the controller and detection module. The detection module is connected to the other end of the rectifier module and is used to detect the DC bus voltage and generate a corresponding voltage feedback signal. The controller is connected to the relay, the switching power supply module, and the detection module respectively. When the air conditioner is powered on and in standby mode, it receives the voltage feedback signal, determines the corresponding actual DC bus voltage based on the voltage feedback signal, compares the actual DC bus voltage with the sum of a preset minimum operating voltage threshold and a hysteresis voltage threshold, and controls the on / off state of the relay based on the comparison result to switch the conduction path of the buffer start-up module, thereby adjusting the power supply state of the input power supply to the rectifier module. The preset minimum operating voltage threshold is the minimum input voltage required for the switching power supply module to operate. Specifically, before comparing the actual DC bus voltage with the sum of a preset minimum operating voltage threshold and a hysteresis voltage threshold, and controlling the on / off state of the relay based on the comparison result, the controller is configured as follows: The relay is controlled to remain closed for a first preset time. When comparing the actual DC bus voltage with the sum of a preset minimum operating voltage threshold and a hysteresis voltage threshold, and controlling the on / off state of the relay based on the comparison result, the controller is configured to: Obtain the first duration of the relay closure; When the first duration is greater than the first preset time, and the actual DC bus voltage is less than or equal to the sum of the preset minimum operating voltage threshold and the hysteresis voltage threshold, it is determined whether the actual DC bus voltage is less than the preset minimum operating voltage threshold. If so, then control the relay to remain in the closed state; When comparing the actual DC bus voltage with the sum of a preset minimum operating voltage threshold and a hysteresis voltage threshold, and controlling the on / off state of the relay based on the comparison result, the controller is further configured to: When the first duration is greater than the first preset time, and the actual DC bus voltage is greater than the sum of the preset minimum operating voltage threshold and the hysteresis voltage threshold, the relay is controlled to disconnect, and the currently detected actual DC bus voltage is stored as the maximum bus voltage value.

2. The air conditioner according to claim 1, characterized in that, Before receiving the voltage feedback signal, the controller is configured to: The relay is controlled to disconnect, so that the AC input voltage provided by the input power supply powers the rectifier module through the path of the PTC resistor to establish the DC bus voltage, thereby powering on the switching power supply module, the detection module and the controller and putting them into normal operation.

3. The air conditioner according to claim 1, characterized in that, After controlling the relay to disconnect and storing the currently detected actual DC bus voltage as the maximum bus voltage, the controller is configured to: Obtain the second duration of the relay being disconnected, and the new maximum bus voltage during the relay being disconnected; The on / off state of the relay is controlled based on the second duration and the new maximum value of the bus voltage.

4. The air conditioner according to claim 3, characterized in that, When controlling the on / off state of the relay based on the second duration and the new maximum bus voltage, the controller is configured to: Determine the difference between the new maximum bus voltage and the hysteresis voltage threshold; When the actual DC bus voltage is less than the difference and the second duration is greater than the second preset time, the relay is controlled to close.

5. The air conditioner according to claim 4, characterized in that, When the actual DC bus voltage is less than the difference and the second duration is greater than the second preset time, and the relay is controlled to close, the controller is configured to: Obtain the third duration of the relay closure; After the third duration reaches the third preset time, the relay is controlled to disconnect.

6. The air conditioner according to claim 4, characterized in that, When acquiring the new maximum bus voltage during the period when the relay is disconnected, the controller is configured to: Obtain the first voltage feedback signal during the period when the relay is disconnected; The first actual DC bus voltage is determined based on the first voltage feedback signal; When the first actual DC bus voltage is greater than the maximum bus voltage, the first actual DC bus voltage is updated to the new maximum bus voltage and stored.

7. The air conditioner according to claim 1, characterized in that, When comparing the actual DC bus voltage with the sum of a preset minimum operating voltage threshold and a hysteresis voltage threshold, and controlling the on / off state of the relay based on the comparison result, the controller is further configured to: The actual DC bus voltage of the relay during the open or closed period is acquired in real time, and when the current actual DC bus voltage is detected to be greater than the stored maximum bus voltage value, the current actual DC bus voltage is updated to the latest maximum bus voltage value and stored.

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