Air conditioner

Abstract

The application provides an air conditioner, which comprises an alternating current power supply for outputting alternating current, a rectifier circuit electrically connected with the alternating current power supply and used for converting the alternating current into direct current, a PFC circuit electrically connected with the rectifier circuit, an energy storage capacitor connected in parallel with the PFC circuit, a load element electrically connected with the energy storage capacitor and connected in parallel with the energy storage capacitor, a PTC resistor arranged between the rectifier circuit and the PFC circuit, a main relay arranged between the rectifier circuit and the PFC circuit and connected in parallel with the PTC resistor, and a controller, wherein the controller is configured to: after the load element is powered off and before the load element is powered on again, the alternating current power supply supplies power, the main relay is controlled to be in a power-off state, and it is judged whether the alternating current reaches a first threshold condition or whether the direct current reaches a second threshold condition; when the alternating current reaches the first threshold condition and the direct current reaches the second threshold condition, it is determined that a surge current is generated at this time, a time delay is performed for a period of time to wait for the energy storage capacitor to be charged, and then the main relay is controlled to be powered on.

Description

Technical Field

[0001] This invention relates to the field of household appliance technology, and more particularly to an air conditioner. Background Technology

[0002] With the development of PFC at higher frequencies, PFC inductors are becoming smaller and smaller. Furthermore, at ultra-high frequencies, such as above 60kHz, new materials like SiC diodes are required. For the same voltage fluctuation, a smaller inductance results in a larger inrush current. At the same time, SiC diodes are significantly weaker in surge current resistance than diodes made of traditional materials. This trade-off increases the risk of surge damage to devices, necessitating optimization to mitigate this risk.

[0003] In the air conditioning industry, surge protection circuits typically use a combination of relays and PTC resistors. Their working principle is as follows: Upon power-up, because Vdc is 0V and Vac's peak voltage is 310V (taking a mains voltage of 220V / 50Hz as an example), the voltage difference causes capacitor C1 to charge. Simultaneously, because the PTC circuit has a very low resistance and a large voltage difference, a large surge current is generated. Connecting the PTC resistor increases the overall circuit impedance, effectively reducing the current and preventing excessive current from exceeding the hardware's capacity. After capacitor C1 is fully charged, there is no voltage difference between the peak values ​​of Vdc and Vac, preventing surge current. The main relay can then close, disconnecting the PTC circuit and ensuring smooth power supply to subsequent loads.

[0004] While the above technical solutions can avoid surges during power-on, they cannot effectively suppress other surge current scenarios. Specifically, during the operation of an air conditioner compressor, if the compressor suddenly loses power and then regains power, the lack of electrical input due to the momentary power loss causes the stored energy in the capacitor to be rapidly consumed before the compressor stops, resulting in a rapid drop in the capacitor's voltage. When power is restored at this time, the peak value of Vac is significantly higher than the Vdc voltage, and the main relay is still energized, thus generating a surge current impact.

[0005] In view of the above, this application is hereby submitted. Summary of the Invention

[0006] This application provides an air conditioner that, when the load element is briefly de-energized and then powered on again, determines the state of AC and DC power and controls the operation of the main relay to prevent surge current from impacting hardware devices when the voltage rises, thus preventing hardware failure.

[0007] This application provides an air conditioner, comprising:

[0008] AC power supply, used to output alternating current;

[0009] a rectifier circuit electrically connected with the AC power supply, for converting the AC power into DC power;

[0010] a PFC circuit electrically connected with the rectifier circuit;

[0011] an energy storage capacitor connected in parallel with the PFC circuit;

[0012] a load element electrically connected with the energy storage capacitor and connected in parallel with the energy storage capacitor;

[0013] a PTC resistor arranged between the rectifier circuit and the PFC circuit;

[0014] a main relay arranged between the rectifier circuit and the PFC circuit and connected in parallel with the PTC resistor;

[0015] a controller configured to: after the load element is powered off and before the load element is powered on again, the AC power supply is powered on, control the main relay to be in a powered-off state, and determine whether the AC power reaches a first threshold condition or the DC power reaches a second threshold condition;

[0016] when the AC power reaches the first threshold condition and the DC power reaches the second threshold condition, it is determined that a surge current will be generated at this time, a period of time is delayed to wait for the energy storage capacitor to be charged, and the main relay is controlled to be powered on.

[0017] In some embodiments of the present application, the controller is configured to: when the AC power does not reach the first threshold condition and / or the DC power does not reach the second threshold condition, the main relay is powered off, and when the AC power reaches the first threshold condition and the DC power reaches the second threshold condition, the main relay is powered on.

[0018] In some embodiments of the present application, the controller is configured to: when the main relay is in a powered-on state, determine whether the AC power reaches the first threshold condition or the DC power reaches the second threshold condition;

[0019] when the AC power does not reach the first threshold condition and / or the DC power does not reach the second threshold condition, the main relay is controlled to be powered off.

[0020] In some embodiments of the present application, the controller is configured to: when the main relay is in a powered-on state, determine whether the AC power reaches the first threshold condition and / or the DC power reaches the second threshold condition;

[0021] when the AC power reaches the first threshold condition and the DC power reaches the second threshold condition, the main relay is controlled to maintain the powered-on state.

[0022] In some embodiments of the present application, the controller is configured to: when the load element does not need to run, control the main relay to be powered off, and when the load element runs, control the main relay to be powered on.

[0023] In some embodiments of the present application, the main relay is powered on, and the load element is powered on after a delay, so as to avoid interference to part of the power supply when the main relay is powered on.

[0024] In some embodiments of the present application, the load element is turned off when the AC power is in a low voltage state or the DC power is in a low voltage state.

[0025] After the AC power and the DC power are not in the low voltage state, the load element continues to work.

[0026] In some embodiments of the present application, when the AC power reaches a first threshold condition and maintains for a period of time, it is determined that the AC power is in a low voltage state.

[0027] In some embodiments of the present application, when the DC power reaches a second threshold condition and maintains for a period of time, it is determined that the DC power is in a low voltage state.

[0028] In some embodiments of the present application, when the instantaneous value of the AC power exceeds the instantaneous value of the DC power by a certain value and maintains for a period of time, the main relay is not powered on immediately after being powered off.

[0029] In the above embodiments, the present application provides an air conditioner, which comprises an AC power supply for outputting AC power, a rectifier circuit electrically connected with the AC power supply and used for converting the AC power into DC power, a PFC circuit electrically connected with the rectifier circuit, an energy storage capacitor connected in parallel with the PFC circuit, a load element electrically connected with the energy storage capacitor and connected in parallel with the energy storage capacitor, a PTC resistor arranged between the rectifier circuit and the PFC circuit, a main relay arranged between the rectifier circuit and the PFC circuit and connected in parallel with the PTC resistor, and a controller. Before the load element is powered on again, the AC power supply is powered on, the main relay is controlled to be in a power-off state, and it is determined whether the AC power reaches a first threshold condition or the DC power reaches a second threshold condition. When the AC power reaches the first threshold condition and the DC power reaches the second threshold condition, it is determined that a surge current is generated, a delay is performed for a period of time to wait for the energy storage capacitor to be charged, and the main relay is controlled to be powered on. By controlling the action of the main relay, the surge current generated by the voltage drop caused by the power grid under the condition that the air conditioner is powered off for a short time and then powered on again is eliminated, and hardware failure is avoided. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0031] Figure 1 A refrigeration system diagram of an air conditioner according to an exemplary embodiment;

[0032] Figure 2 A connection diagram of an air conditioner and a control device according to an exemplary embodiment;

[0033] Figure 3 A hardware configuration block diagram of an air conditioner according to an exemplary embodiment;

[0034] Figure 4 A hardware configuration block diagram of a controller according to an exemplary embodiment;

[0035] Figure 5 Control logic for eliminating inrush current of a controller according to an exemplary embodiment;

[0036] Figure 6 Control logic of a main relay according to an exemplary embodiment;

[0037] Figure 7 Control logic for determining low voltage state of AC power according to an exemplary embodiment;

[0038] Figure 8 Control logic for determining low voltage state of DC power according to an exemplary embodiment;

[0039] Figure 9 Another control logic for eliminating inrush current of a controller according to an exemplary embodiment;

[0040] Figure 10 Another control logic for eliminating inrush current of a controller according to an exemplary embodiment;

[0041] Figure 11 A hardware circuit diagram of the present application according to an exemplary embodiment;

[0042] In the above figures:

[0043] Air conditioner 100; compressor 1; condenser 2; expansion valve 3; evaporator 4;

[0044] Control device 5; controller 71; processor 83; memory 82; communication interface 84; bus 81;

[0045] AC power source 6; rectifier circuit 7; PFC circuit 8; energy storage capacitor 9; load element 10;

[0046] PTC resistor 11; main relay 12. DETAILED DESCRIPTION

[0047] The application will be described in detail below with reference to exemplary embodiments. However, it should be understood that elements, structures and features in one embodiment can be beneficially combined with elements, structures and features of other embodiments without further recitation.

[0048] In the description of the present application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0049] The terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features.

[0050] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be direct connection, or indirect connection through intermediate medium, or internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0051] The embodiment of the present application provides an air conditioner 100, referring to Figure 1 The air conditioner 100 includes a refrigeration system for heat exchange with indoor air to achieve refrigeration or heating requirements.

[0052] The refrigeration system includes a compressor 1, a condenser 2, an expansion valve 3 and an evaporator 4. In the present application, the air conditioner 100 performs the refrigeration cycle of the air conditioner 100 by using the compressor 1, the condenser 2, the expansion valve 3 and the evaporator 4. The refrigeration cycle includes a series of processes involving compression, condensation, expansion and evaporation, and supplies refrigerant to the air that has been adjusted and heat exchanged.

[0053] The compressor 1 compresses the refrigerant gas in a high temperature and high pressure state and discharges the compressed refrigerant gas. The discharged refrigerant gas flows into the condenser 2. The condenser 2 condenses the compressed refrigerant into a liquid phase, and heat is released to the surrounding environment through the condensation process.

[0054] The expansion valve 3 expands the high-temperature and high-pressure liquid-phase refrigerant condensed in the condenser 2 into a low-pressure liquid-phase refrigerant. The evaporator 4 evaporates the refrigerant expanded in the expansion valve 3 and returns the refrigerant gas in a low-temperature and low-pressure state to the compressor 1.

[0055] The evaporator 4 can achieve a refrigeration effect by exchanging heat with a material to be cooled using latent heat of evaporation of the refrigerant. Throughout the cycle, the air conditioner 100 can adjust the temperature of an indoor space.

[0056] The outdoor unit of the air conditioner 100 refers to a portion of the refrigeration cycle including the compressor 1 and the outdoor heat exchanger, the indoor unit of the air conditioner 100 includes the indoor heat exchanger, and the expansion valve 3 can be provided in the indoor unit or the outdoor unit.

[0057] The indoor heat exchanger and the outdoor heat exchanger function as the condenser 2 or the evaporator 4. When the indoor heat exchanger functions as the condenser 2, the air conditioner 100 functions as a heater in a heating mode, and when the indoor heat exchanger functions as the evaporator 4, the air conditioner 100 functions as a cooler in a cooling mode.

[0058] The air conditioner 100 in the present application can be provided as an all-in-one machine or a split machine, and can be provided as a cabinet machine or a hanging machine.

[0059] For example, the indoor hanging machine (not shown in the figure) is usually installed at a position such as an indoor wall, and the indoor cabinet machine (not shown in the figure) is also a type of indoor machine.

[0060] For example, the air conditioner 100 includes an indoor machine and an outdoor machine, and the outdoor machine is usually provided outdoors and is used for heat exchange with an indoor environment.

[0061] In addition, as shown in the Figure 2 The air conditioner 100 is provided with a controller 71 to control the operation of each component in the air conditioner 100, so that each component of the air conditioner 100 operates to achieve the predetermined functions of the air conditioner 100. In the air conditioner 100, a control device 5 is also attached, which is exemplarily provided as a remote controller having a function of communicating with the controller 71, for example, by using infrared rays or other communication methods. The remote controller is used for various controls of the air conditioner 100 by the user, so as to realize the interaction between the user and the air conditioner 100.

[0062] With reference to Figure 3 The air conditioner 100 provided by the embodiment of the present application includes an alternating current power supply 6, a rectifier circuit 7 electrically connected with the alternating current power supply 6, a PFC circuit 8 electrically connected with the rectifier circuit 7, an energy storage capacitor 9 connected in parallel with the PFC circuit 8, a load element 10 electrically connected with the energy storage capacitor 9 and connected in parallel with the energy storage capacitor 9, a PTC resistor 11, a main relay 12, and a controller 71,

[0063] The PTC resistor 11 is positioned between the rectifier circuit 7 and the PFC circuit 8, and the main relay 12 is positioned between the rectifier circuit 7 and the PFC circuit, with the main relay 12 connected in parallel with the PTC resistor 11. The controller 71 is electrically connected to the main relay 12, the load element 10, and the PFC circuit 8 to control the on / off state of the main relay 12, the operating state of the load element 10, and the input PWM signal of the PFC circuit 8.

[0064] In the embodiments shown in this application, controller 7171 refers to a device that can generate operation control signals according to instruction operation codes and timing signals, instructing air conditioner 100100 to execute control commands. For example, in response to a power-on or power-off command issued by a user, controller 7171 can perform an operation related to the object selected by the power-on or power-off command.

[0065] This application also provides a hardware structure diagram of a controller 7171, as shown in the embodiment. Figure 4 As shown, the controller 7171 includes a processor 83, and optionally, a memory 82 and a communication interface 8 connected to the processor 83. The processor 83, memory 82, and communication interface 8 are connected via a bus 81.

[0066] 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 (MCU), a microcontroller (71718), 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 (single-CPU) processor 83 or a multi-core (multi-CPU) 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).

[0067] The memory 82 can be a read-only memory (ROM) or other type of static storage device that can store static information and instructions, a random access memory (RAM), or other type of dynamic storage device that can store information and instructions, an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disk storage, a magneto-optical disk storage, a magnetic disk storage or other magnetic storage devices, or any other medium capable of storing instructions or data that can be accessed by a computer, and the embodiments of the present application do not make any limitation on this. The memory 82 can exist independently or be integrated with the processor 83. The memory 82 can contain computer program codes. The processor 83 is configured to execute the computer program codes stored in the memory 82, so as to implement the control method of the multi-connection air conditioning system 100100100 provided by the embodiments of the present application.

[0068] The communication interface 8 can be configured to communicate with other devices or communication networks (such as Ethernet, radio access network (RAN), wireless local area networks (WLAN), etc. The communication interface 8 can be a module, a circuit, a transceiver, or any device capable of realizing communication.

[0069] The bus 81 can be a peripheral component interconnect (PCI) bus 81 or an extended industry standard architecture (EISA) bus 81, etc. The bus 81 can be divided into an address bus 81, a data bus 81, a control bus 81, etc. For the convenience of representation, Figure 11 Only one thick line is used in the figure, but it does not mean that there is only one bus 81 or only one type of bus 81.

[0070] In the process of powering on the air conditioner 100, the main relay 12 does not work, that is, the main relay 12 is in a power-off state, to prevent the surge current from being too large to impact the rectifier diode in the rectifier circuit 7. After the energy storage capacitor 9 in the main circuit is fully charged, the main relay 12 is powered on, that is, the main relay 12 is in an attracted state, the PTC resistor 11 is short-circuited, the entire controller 71 is normally powered, and the main relay 12 is maintained in the powered-on state after this node until the controller 71 is powered off.

[0071] It should be noted that in actual application, the smaller the surge current is, the stronger the anti-surge capability of the device is, and the smaller the risk of damage to the hardware device is; the larger the surge current is, and the weaker the anti-surge capability of the hardware device is, and the greater the risk of damage to the hardware is.

[0072] In order to solve the problem that the load element 10 of the air conditioner 100 is powered off and re-powered in the process of running, and when the main relay 12 is still in the powered-on state, a surge current is generated to impact the hardware due to the fact that the peak value of the alternating current is significantly higher than the voltage of the direct current.

[0073] In some embodiments of the present embodiment, the controller 71 is configured to: after the load element 10 is powered off and before the load element 10 is powered on again, the alternating current source 6 supplies power, the main relay 12 is controlled to be in a power-off state, and it is determined whether the alternating current reaches a first threshold condition or the direct current reaches a second threshold condition;

[0074] When the alternating current reaches the first threshold condition and the direct current reaches the second threshold condition, it is determined that a surge current will be generated at this time, a time delay is performed to wait for the charging of the energy storage capacitor 9, and the main relay 12 is controlled to be powered on.

[0075] In some embodiments of the present application, when the alternating current is in a low-voltage state or the direct current is in a low-voltage state, the load element 10 is turned off;

[0076] After the alternating current and the direct current are not in the low-voltage state, the load element 10 continues to work.

[0077] Referring to Figure 5 , the control logic of the controller 71 for eliminating the surge current in the present embodiment is described.

[0078] The load element 10 is powered off (step S501); the alternating current source 6 supplies power (step S502); the main relay 12 is controlled to be in a power-off state (step S503); it is determined whether the alternating current reaches a first threshold condition (step S504);

[0079] In step S504, if the alternating current reaches the first threshold condition, step S505 is performed to determine whether the direct current reaches a second threshold condition;

[0080] In step S505, if the direct current reaches the second threshold condition, step S507 is performed, and a time delay is performed to wait for the charging of the energy storage capacitor 9; the main relay 12 is powered on (step S508)

[0081] In step S505, if the direct current does not reach the second threshold condition, step S506 is performed.

[0082] In step S504, if the alternating current does not reach the first threshold condition, step S506 is performed, and the main relay 12 is not powered on.

[0083] Through the above steps, when the alternating current reaches the first threshold condition and the direct current reaches the second threshold condition, it is determined that a surge current may be generated at this time, and the main relay 12 is powered on after a time delay, so that the energy storage capacitor 9 is charged, and the voltage across the energy storage capacitor 9 is increased, thereby avoiding damage to hardware devices caused by the surge current.

[0084] In the current 3-horsepower air conditioner 100, if the PFC carrier frequency is 40K (high-frequency scheme), the PFC inductance is about 430uH, and an FDR diode is used, and if the PFC carrier frequency is 65K (ultra-high-frequency scheme), the PFC inductance is reduced to 250uH, and an SiC diode is used. In the process of powering off and powering on the load element 10, compared with the ultra-high-frequency scheme, the surge current of the high-frequency scheme increases by about 70%. However, the anti-surge capability of the SiC diode is weaker than that of the FDR diode, so it is necessary to improve the surge current generated in the process of powering off and powering on the load element 10.

[0085] In the present application, the voltage of the alternating current or the direct current is judged, and the main relay 12 is powered off when the alternating current or the direct current is lower than the corresponding threshold value, so that the PTC resistor 11 is connected in series to the main circuit. If the alternating current or the direct current rises to a certain value, the main relay 12 is powered on after a time delay, the PTC resistor 11 is bypassed, and the load element 10 at the rear end of the air conditioner 100 can be normally powered and operated. On the basis of the low-voltage protection logic of the alternating current, the low-voltage protection logic of the direct current, and the fault elimination logic, the powering off of the main relay 12 is added, and after the fault is eliminated, the powering on of the main relay 12 is added, thereby avoiding the impact of the surge current on the hardware devices when the voltage rises, and avoiding hardware failure.

[0086] Referring to Figure 10 , another control logic for eliminating the surge current of the controller 71 in the embodiment of the present application is described.

[0087] The load element 10 is powered off (step S1001); the AC power source 6 is powered on (step S1002); the main relay 12 is controlled to be in a powered-off state (step S1003); it is determined whether the AC power reaches a first threshold condition (step S1004);

[0088] In step S1004, if the AC power reaches the first threshold condition, step S1005 is performed to determine whether the DC power reaches a second threshold condition;

[0089] In step S1005, if the DC power reaches the second threshold condition, step S1007 is performed to delay for a period of time to wait for the charging of the energy storage capacitor 9; the main relay 12 is controlled to be powered on (step S1008)

[0090] In step S1005, if the DC power does not reach the second threshold condition, step S1006 is performed.

[0091] In step S1004, if the AC power does not reach the first threshold condition, step S1006 is performed to delay for a period of time, and the main relay 12 is controlled not to be powered on (step S1009).

[0092] In some embodiments of the present application, the controller 71 is configured to: when the AC power does not reach the first threshold condition and / or the DC power does not reach the second threshold condition, the main relay 12 is powered off, until the AC power reaches the first threshold condition and the DC power reaches the second threshold condition, the main relay 12 is powered on.

[0093] Referring to Figure 9 , another control logic of the controller 71 for eliminating inrush current in the embodiments of the present application is described.

[0094] The load element 10 is powered off (step S901); the AC power source 6 is powered on (step S902); the main relay 12 is controlled to be in a powered-off state (step S903); it is determined whether the AC power reaches a first threshold condition (step S904);

[0095] In step S904, if the AC power reaches the first threshold condition, step S905 is performed to determine whether the DC power reaches a second threshold condition;

[0096] In step S905, if the DC power reaches the second threshold condition, step S907 is performed to delay for a period of time to wait for the charging of the energy storage capacitor 9; the main relay 12 is controlled to be powered on (step S908)

[0097] In step S905, if the DC power does not reach the second threshold condition, step S906 is performed.

[0098] If the AC power does not reach the first threshold condition, step S906 is performed, and the main relay 12 is controlled to be powered off.

[0099] After step S906 is performed, it is determined whether the AC power reaches the first threshold condition and the DC power reaches the second threshold condition (step S909).

[0100] If the AC power reaches the first threshold condition and the DC power reaches the second threshold condition, step S908 is performed.

[0101] If the AC power does not reach the first threshold condition or the DC power does not reach the second threshold condition, step S909 is performed.

[0102] In some embodiments of the present application, the controller 71 is configured to determine whether the AC power reaches the first threshold condition or the DC power reaches the second threshold condition when the main relay 12 is in the powered-on state.

[0103] When the AC power does not reach the first threshold condition and / or the DC power does not reach the second threshold condition, the main relay 12 is controlled to be powered off.

[0104] In some embodiments of the present application, the controller 71 is configured to determine whether the AC power reaches the first threshold condition and / or the DC power reaches the second threshold condition when the main relay 12 is in the powered-on state.

[0105] When the AC power reaches the first threshold condition and the DC power reaches the second threshold condition, the main relay 12 is controlled to maintain the powered-on state.

[0106] Referring to Figure 6 , the control logic of the main relay 12 in the embodiments of the present application is described.

[0107] It is determined whether the main relay 12 is in the powered-on state (step S601).

[0108] If the main relay 12 is in the powered-on state, step S602 is performed, and it is determined whether the AC power reaches the first threshold condition.

[0109] If the AC power reaches the first threshold condition, step S603 is performed, and it is determined whether the DC power reaches the second threshold condition.

[0110] If the AC power does not reach the first threshold condition, step S604 is performed, and the main relay 12 is controlled to be powered off.

[0111] If the DC power reaches the second threshold condition, step S605 is performed, and the powered-on state of the main relay 12 is maintained.

[0112] In step S603, if the direct current does not reach the second threshold condition, step S604 is performed.

[0113] In some embodiments of the present application, the controller 71 is configured to control the main relay 12 to be powered off when the load element 10 does not need to operate, and to be powered on when the load element 10 operates. This is to accommodate the situation where the load element of the air conditioner, such as the compressor and the fan motor, cannot operate normally when the main relay 12 is disconnected because the reactance of the PTC resistor is large.

[0114] In some embodiments of the present application, after the main relay 12 is powered on, the load element 10 is powered on to operate after a period of time, so as to avoid interference to part of the power supply when the main relay 12 is powered on.

[0115] In some embodiments of the present application, when the alternating current reaches the first threshold condition and maintains for a period of time, it is determined that the alternating current is in a low-voltage state.

[0116] Referring to Figure 7 , the control logic for determining that the alternating current is in a low-voltage state is described.

[0117] It is determined whether the alternating current is less than a first preset value (step S701);

[0118] In step S701, if the alternating current is less than the first preset value, step S702 is performed, and the time duration is accumulated, time = time++, and it is determined whether the current state duration reaches a first preset time (step S703);

[0119] In step S703, if the current state duration reaches the first preset time, step S704 is performed, the alternating current flag is a low-voltage bit, i.e., the current alternating current is in a low-voltage state, and the duration is reset to zero. For example, the low-voltage bit is Vac_low = 1, and time = 0.

[0120] In step 703, if the current state duration does not reach the first preset time, step S702 is performed.

[0121] In step S701, if the alternating current is not less than the first preset value, step S705 is performed, the alternating current flag bit is a non-low-voltage bit, i.e., the alternating current is not in a low-voltage state, and the time accumulation is not performed, i.e., Vac_low = 0, and time = 0.

[0122] In some embodiments of the present application, when the direct current reaches the second threshold condition and maintains for a period of time, it is determined that the direct current is in a low-voltage state.

[0123] Referring to Figure 8 , the control logic for determining that the direct current is in a low-voltage state is described.

[0124] determining whether the direct current is less than a second preset value (step S801) ;

[0125] In step S801, if the direct current is less than the second preset value, step S802 is executed, the time duration is accumulated, time = time++, and it is determined whether the current state duration reaches the second preset time (step S803) ;

[0126] In step S803, if the current state duration reaches the second preset time, step S804 is executed, the direct current flag is low voltage bit, i.e., the current direct current is in low voltage state, the time duration is reset to zero, and the low voltage bit is Vdc_low = 1 and time = 0.

[0127] In step S703, if the current state duration does not reach the second preset time, step S802 is executed.

[0128] In step S801, if the direct current is not less than the second preset value, step S805 is executed, the direct current flag bit is non-low voltage bit, i.e., the direct current is not in low voltage state, and the time accumulation is not performed, i.e., Vdc_low = 0 and time = 0.

[0129] In some embodiments of the present application, when the instantaneous value of the alternating current exceeds the instantaneous value of the direct current by a certain value and for a period of time, the main relay 12 is not immediately powered on after being powered off.

[0130] In some embodiments of the present application, the load element 10 is specifically set as the compressor 1. During the process of power failure and re-powering of the compressor 1, due to instantaneous power failure, there is no power input, and the stored power in the energy storage capacitor 9 is quickly consumed before the compressor 1 stops, causing the capacitance of the energy storage capacitor 9 to quickly decrease. If the power is immediately turned on at this time, the peak value of the alternating current is obviously higher than the voltage of the direct current, and if the main relay 12 is still in the power-on state, i.e., the PTC resistor 11 is powered off, a surge current will be generated, which will cause an impact on the hardware devices.

[0131] On the basis of the low voltage protection judgment logic of the alternating current of the air conditioner 100 and the low voltage protection judgment logic of the direct current, the present application increases the execution of power-off of the main relay 12 in the fault handling mechanism and the execution of power-on of the main relay 12 after the fault is removed, to solve the surge current generated in the case of sudden voltage drop and surge, and to avoid hardware damage.

[0132] The air conditioner 100100 in the embodiment includes an alternating current power supply 6 for outputting alternating current, a rectifier circuit 7 electrically connected with the alternating current power supply 6 and used for converting the alternating current into direct current, a PFC circuit 8 electrically connected with the rectifier circuit 7, an energy storage capacitor 9 connected in parallel with the PFC circuit 8, a load element 10 electrically connected with the energy storage capacitor 9 and connected in parallel with the energy storage capacitor 9, a PTC resistor 11 arranged between the rectifier circuit 7 and the PFC circuit 8, a main relay 12 arranged between the rectifier circuit 7 and the PFC circuit 8 and connected in parallel with the PTC resistor 11, and a controller 71, wherein the controller 71 is configured to, after the load element 10 is powered off and before the load element 10 is powered on again, supply power by the alternating current power supply 6, control the main relay 12 to be in a power-off state, and determine whether the alternating current reaches a first threshold condition or the direct current reaches a second threshold condition; when the alternating current reaches the first threshold condition and the direct current reaches the second threshold condition, it is determined that a surge current will be generated at this time, a time delay is performed for a period of time to wait for the energy storage capacitor 9 to be charged, and the main relay 12 is controlled to be powered on. By controlling the action of the main relay 12, the surge current generated by the voltage drop caused by the power grid anomaly when the air conditioner 100 is powered off for a short time and then powered on is eliminated, and hardware failure is avoided.

[0133] The above merely provides a specific implementation of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. An air conditioner, characterized in that, AC power supply, used to output alternating current; A rectifier circuit, which is electrically connected to the AC power supply, is used to convert the AC power into DC power; The PFC circuit is electrically connected to the rectifier circuit; An energy storage capacitor is connected in parallel with the PFC circuit. A load element, which is electrically connected to the energy storage capacitor and connected in parallel with the energy storage capacitor; A PTC resistor is disposed between the rectifier circuit and the PFC circuit; A main relay is located between the rectifier circuit and the PFC circuit and is connected in parallel with the PTC resistor; The controller is configured to: supply power to the AC power source after the load element is de-energized and before it is re-energized, control the main relay to be in a de-energized state, and determine whether the AC power reaches a first threshold condition or the DC power reaches a second threshold condition at this time. When the AC current reaches the first threshold condition and the DC current reaches the second threshold condition, it is determined that a surge current will be generated at this time. After a delay to wait for the energy storage capacitor to charge, the main relay is controlled to be powered on.

2. The air conditioner according to claim 1, characterized in that, The controller is configured to de-energize the main relay when the AC current does not reach a first threshold condition and / or the DC current does not reach a second threshold condition, until the AC current reaches the first threshold condition and the DC current reaches the second threshold condition, at which point the main relay is energized.

3. The air conditioner according to claim 1, characterized in that, The controller is configured to: when the main relay is powered on, determine whether the AC current reaches a first threshold condition or the DC current reaches a second threshold condition. When the AC current does not reach the first threshold condition and / or the DC current does not reach the second threshold condition, the main relay is controlled to be de-energized.

4. The air conditioner according to claim 3, characterized in that, The controller is configured to: when the main relay is powered on, determine whether the AC current reaches a first threshold condition and / or whether the DC current reaches a second threshold condition. When the AC current reaches the first threshold condition and the DC current reaches the second threshold condition, the main relay is controlled to maintain the energized state.

5. The air conditioner according to claim 1, characterized in that, The controller is configured to: de-energize the main relay when the load element is not required to operate, and energize the main relay when the load element is operating.

6. The air conditioner according to claim 1, characterized in that, After the main relay is powered on, the load element needs to be powered on and operated after a certain period of time to avoid interference to some power supply components when the main relay is powered on.

7. The air conditioner according to claim 1, characterized in that, When the AC power is at a low voltage or the DC power is at a low voltage, the load element is turned off; Once both the AC and DC power supplies are no longer in a low-voltage state, the load element continues to operate.

8. The air conditioner according to claim 7, characterized in that, When the alternating current reaches the first threshold condition and is maintained for a period of time, it is determined that the alternating current is in a low-voltage state.

9. The air conditioner according to claim 7, characterized in that, When the DC current reaches the second threshold condition and is maintained for a period of time, it is determined that the DC current is in a low-voltage state.

10. The air conditioner according to claim 1, characterized in that, When the instantaneous value of the alternating current exceeds a certain instantaneous value of the direct current for a period of time, the main relay will not be immediately powered on after being de-energized.

Images