Air conditioner

Abstract

The invention provides an air conditioner. Comprising an alternating current power supply for outputting alternating current, a rectifying circuit which is electrically connected with the alternating current power supply and is used for converting the alternating current into direct current, a PFC circuit which is electrically connected with the rectifying circuit, an energy storage capacitor which is connected with the PFC circuit in parallel, and a load element which is electrically connected with the energy storage capacitor and is connected with the energy storage capacitor in parallel, the PTC resistor is arranged between the rectifying circuit and the PFC circuit, the main relay is arranged between the rectifying circuit and the PFC circuit and connected with the PTC resistor in parallel, and the controller is configured in the mode that after a load element is powered off and before the load element is powered on again, an alternating-current power source supplies power, the main relay is controlled to be in a power-off state, and the main relay is controlled to be in a power-off state. Judging 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 judged that surge current is generated at the moment, and after a period of time is delayed to wait for charging of the energy storage capacitor, the main relay is controlled to be powered on.

Description

Technical Field

[0001] The present invention relates to the technical field of household appliances, and in particular to an air conditioner. Background Art

[0002] With the development of high-frequency PFC, PFC inductors are getting smaller and smaller, and at ultra-high frequencies, such as above 60k, new material diodes such as SiC are needed. For the same voltage fluctuation, the smaller the inductance, the greater the surge current generated. At the same time, SiC diodes are much weaker than traditional material diodes in terms of surge current resistance. As a result, the risk of surge damage to devices is increasing, and optimization is needed to reduce the risk.

[0003] The surge protection circuit commonly used in the air-conditioning industry is a combination of relays and PTC resistors. Its working principle is: when power is turned on, because the voltage of Vdc is 0 and the voltage peak of Vac is 310V (taking the mains power of 220V / 50Hz as an example), the capacitor C1 will be charged due to the voltage difference. At the same time, because the resistance of the PTC circuit is very small and the voltage difference is large, a large surge current will be generated. At this time, the PTC resistor is connected in series, which will increase the impedance of the entire loop and effectively reduce the current size to avoid excessive current exceeding the hardware's tolerance range. After the capacitor C1 is charged, there is no voltage difference between the peak values ​​of Vdc and Vac, and no surge current will be generated. The main relay can be closed to disconnect the PTC circuit, which can ensure smooth power supply to subsequent loads.

[0004] Although the above technical solution can avoid surges when powering on, other surge current situations cannot be well suppressed. Specifically, when the compressor of the air conditioner is running, the compressor suddenly loses power and is powered on again. Due to the instantaneous power loss and no power input, the power stored in the capacitor will be quickly consumed before the compressor stops, causing the voltage of the capacitor to drop rapidly. At this time, when power is turned on, the peak value of Vac is significantly higher than the Vdc voltage, and the main relay is still in the power-on state, resulting in a surge current impact.

[0005] In view of this, this application is filed. Summary of the invention

[0006] The present application provides an air conditioner, which, when a load element is powered off for a short time and then powered on, determines the state of AC and DC power and controls the action of a main relay to avoid surge current impact on hardware components when the voltage rises, thereby avoiding hardware failure.

[0007] The present application provides an air conditioner, comprising:

[0008] AC power supply, used for outputting AC power;

[0009] A rectifier circuit, which is electrically connected to the AC power source and is used to convert the AC power into DC power;

[0010] A PFC circuit electrically connected to the rectifier circuit;

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

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

[0013] A PTC resistor is provided between the rectifier circuit and the PFC circuit;

[0014] A main relay is provided between the rectifier circuit and the PFC circuit and is connected in parallel with the PTC resistor;

[0015] The controller is configured to: after the load element is powered off and before it is powered on again, the AC power supply supplies power, controls the main relay to be in a power-off state, and determines whether the AC power reaches a first threshold condition or whether the DC power reaches a second threshold condition at this time;

[0016] 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, and a delay is made 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.

[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 the main relay is powered on until the AC power reaches the first threshold condition and the DC power reaches the second threshold condition.

[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 alternating current reaches a first threshold condition or whether the direct current reaches a second threshold condition;

[0019] When the alternating current does not reach the first threshold condition and / or the direct current does not reach the second threshold condition, the main relay is controlled to be de-energized.

[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 alternating current reaches a first threshold condition and / or whether the direct current reaches a second threshold condition;

[0021] When the alternating current reaches a first threshold condition and the direct current reaches a second threshold condition, the main relay is controlled to maintain a power-on state.

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

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

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

[0025] After both the AC and DC are no longer in a low voltage state, the load element continues to work.

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

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

[0028] 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 lasts for a period of time, the main relay is powered off and is no longer powered on immediately.

[0029] In the above embodiments, the present application proposes an air conditioner, which includes an AC power supply for outputting AC power, a rectifier circuit electrically connected to the AC power supply and used to convert AC power into DC power, a PFC circuit electrically connected to the rectifier circuit, an energy storage capacitor connected in parallel with the PFC circuit, a load element electrically connected to 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 it is powered on again, the AC power supply supplies power, controls the main relay to be in a power-off state, and determines whether the AC power reaches the first threshold condition or the DC power reaches the second threshold condition at this time; 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, and a delay period of time is delayed to wait for the energy storage capacitor to be charged, and then 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 abnormality of the power grid when the air conditioner is powered off for a short time and then powered on is eliminated, thereby avoiding hardware failure. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

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

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

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

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

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

[0036] Figure 6 A control logic for a main relay provided according to an exemplary embodiment;

[0037] Figure 7 A control logic for determining that the AC power is in a low voltage state according to an exemplary embodiment;

[0038] Figure 8 A control logic for determining that the DC power is in a low voltage state according to an exemplary embodiment;

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

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

[0041] Fig.11 A hardware circuit diagram of the present application provided 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 supply 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 present invention is described in detail below by way of exemplary embodiments. However, it should be understood that elements, structures, and features in one embodiment may also be beneficially combined in other embodiments without further description.

[0048] In the description of the present invention, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

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

[0050] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

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

[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 a 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 conditioned and heat-exchanged air.

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

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

[0056] The outdoor unit of the air conditioner 100 refers to a portion of a refrigeration cycle including the compressor 1 and an outdoor heat exchanger, the indoor unit of the air conditioner 100 includes an indoor heat exchanger, and the expansion valve 3 may 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 configured as an integrated unit or a split unit, and can be configured as a cabinet unit or a wall-mounted unit.

[0059] Taking an indoor wall mounted unit (not shown in the figure) as an example, the indoor wall mounted unit is usually installed at a location such as an indoor wall. For another example, an indoor cabinet unit (not shown in the figure) is also a form of indoor unit.

[0060] Taking a split unit as an example, the air conditioner 100 includes an indoor unit and an outdoor unit, wherein the outdoor unit is usually arranged outdoors for heat exchange in the indoor environment.

[0061] In addition, if Figure 2 As shown in the figure, the air conditioner 100 is provided with a controller 71 to control the operation of various components in the air conditioner 100 so that the various components of the air conditioner 100 can be operated to realize various predetermined functions of the air conditioner 100. Among them, the air conditioner 100 is also provided with a control device 5. For example, the control device 5 is specifically configured as a remote controller, which has the function of communicating with the controller 71 using infrared or other communication methods, for example. The remote controller is used for the user to perform various controls on the air conditioner 100 and realize the interaction between the user and the air conditioner 100.

[0062] Reference Figure 3 The air conditioner 100 provided in the embodiment of the present application includes an AC power supply 6, a rectifier circuit 7 electrically connected to the AC power supply 6, a PFC circuit 8 electrically connected to the rectifier circuit 7, an energy storage capacitor 9 connected in parallel with the PFC circuit 8, a load element 10 electrically connected to 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 arranged between the rectifier circuit 7 and the PFC circuit 8, and the main relay 12 is arranged between the rectifier circuit 7 and the PFC circuit, and the main relay 12 is 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 and off of the main relay 12, the working state of the load element 10 and the input PWM signal of the PFC circuit 8.

[0064] In the embodiment shown in the present application, the controller 7171 refers to a device that can generate an operation control signal according to the instruction operation code and the timing signal to instruct the air conditioner 100100 to execute the control instruction. For example, in response to a power-on or power-off instruction received from a user, the controller 7171 can perform an operation related to the object selected by the power-on or power-off instruction.

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

[0066] The processor 83 may be a central processing unit 83 (CPU), a general processor 83, a network processor 83 (NP), a digital signal processor 83 (DSP), a microprocessor 83, a microcontroller 71718, a programmable logic device (PLD), or any combination thereof. The processor 83 may also be any other device having a processing function, such as a circuit, a device, or a software module. The processor 83 may also include multiple CPUs, and the processor 83 may be a single-CPU processor 83 or a multi-CPU processor 83. The processor 83 here may refer to one or more devices, circuits, or processing cores for processing data (such as computer program instructions).

[0067] The memory 82 may be a read-only memory 82 (ROM) or other types of static storage devices that can store static information and instructions, a random access memory 82 (RAM) or other types of dynamic storage devices that can store information and instructions, or an electrically erasable programmable read-only memory 82 (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed optical disc, laser disc, optical disc, digital versatile disc, Blu-ray disc, etc.), a disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store the desired program code in the form of an instruction or data structure and can be accessed by a computer, and the present embodiment of the application does not impose any restrictions on this. The memory 82 may exist independently or be integrated with the processor 83. Among them, the memory 82 may contain a computer program code. The processor 83 is used to execute the computer program code stored in the memory 82, so as to realize the control method of the multi-split air conditioner 100100100 system provided in the embodiment of the present application.

[0068] The communication interface 8 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 8 can be a module, a circuit, a transceiver or any device that can achieve communication.

[0069] The bus 81 may be a peripheral component interconnect (PC1) bus 81 or an extended industry standard architecture (EISA) bus 81, etc. The bus 81 may be divided into an address bus 81, a data bus 81, a control bus 81, etc. For ease of representation, Fig.11 Although only one thick line is used in the figure, it does not mean that there is only one bus 81 or only one type of bus 81.

[0070] During the power-on process of 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 excessive surge current from impacting 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 energized state, the PTC resistor 11 is short-circuited, and the entire controller 71 is powered normally. After this node, the main relay 12 is kept powered on until the controller 71 loses power.

[0071] It should be noted that in actual applications, the smaller the surge current and the stronger the device's surge resistance, the smaller the risk of hardware device damage; the larger the surge current and the weaker the hardware device's surge resistance, the greater the risk of hardware damage.

[0072] In order to solve the abnormal use test of the load element 10 of the air conditioner 100 when it loses power and then powers on again during operation, since the peak value of the AC power is significantly higher than the voltage of the DC power, when the main relay 12 is still in the power-on state, a surge current will be generated to impact the hardware.

[0073] In some implementations of this embodiment, the controller 71 is configured as follows: after the load element 10 is powered off and before it is powered on again, the AC power source 6 supplies power, controls the main relay 12 to be in a power-off state, and determines whether the AC power reaches the first threshold condition or the DC power reaches the second threshold condition at this time;

[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, and after a delay period to wait for the energy storage capacitor 9 to be charged, the main relay 12 is controlled to be powered on.

[0075] In some embodiments of the present application, when the AC power is in a low voltage state or the DC power is in a low voltage state, the load element 10 is turned off;

[0076] After the AC power and the DC power are no longer in the low voltage state, the load element 10 continues to work.

[0077] Reference Figure 5 , illustrating the control logic of eliminating surge current of the controller 71 in the embodiment of the present application.

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

[0079] In step S504, if the AC power reaches the first threshold condition, step S505 is executed to determine whether the DC power reaches the second threshold condition;

[0080] In step S505, if the DC power reaches the second threshold condition, step S507 is executed to delay for a period of time to wait for the energy storage capacitor 9 to charge; the main relay 12 is controlled to power on (step S508)

[0081] In step S505, if the DC power does not reach the second threshold condition, step S506 is executed;

[0082] In step S504 , if the AC power does not reach the first threshold condition, step S506 is executed to control the main relay 12 to not be 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, so that the main relay 12 is powered on after a delay of a period of time to charge the energy storage capacitor 9 and increase the voltage across the energy storage capacitor 9, thereby avoiding surge current from damaging hardware devices.

[0084] In the current 3-HP air conditioner 100, if the PFC carrier frequency is 40K (high frequency solution), the PFC inductor is about 430uH, and an FDR diode is used. When the PFC carrier frequency is 65K (ultra-high frequency solution), the PFC inductor will be reduced to 250uH, and a SiC diode will be used. In the process of powering off and then powering on the load element 10 again, the surge current will increase by about 70% compared with the ultra-high frequency and high frequency solutions. However, the surge resistance 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 then powering on the load element 10 again.

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

[0086] Reference Fig.10 , illustrating another control logic of eliminating surge current of the controller 71 in the embodiment of the present application.

[0087] The load element 10 is powered off (step S1001); the AC power source 6 is powered (step S1002); the main relay 12 is controlled to be in a power-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 executed to determine whether the DC power reaches the second threshold condition;

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

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

[0091] In step S1004 , if the AC power does not reach the first threshold condition, step S1006 is executed, a delay is made 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 as follows: 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, and the main relay 12 is powered on until the AC power reaches the first threshold condition and the DC power reaches the second threshold condition.

[0093] Reference Fig. 9 , illustrating another control logic of eliminating surge current of the controller 71 in the embodiment of the present application.

[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 power-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 executed to determine whether the DC power reaches the second threshold condition;

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

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

[0098] In step S904, if the AC power does not reach the first threshold condition, step S906 is executed to control the main relay 12 not to be powered on;

[0099] After executing step S906, determining whether the AC power reaches the first threshold condition and whether the DC power reaches the second threshold condition (step S909);

[0100] In step S909, if the AC power reaches the first threshold condition and the DC power reaches the second threshold condition, then step S908 is executed;

[0101] In step S909, 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 executed.

[0102] In some embodiments of the present application, the controller 71 is configured to: when the main relay 12 is in the power-on state, determine whether the alternating current reaches a first threshold condition or whether the direct current reaches a second threshold condition;

[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 de-energized.

[0104] In some embodiments of the present application, the controller 71 is configured to: when the main relay 12 is in the power-on state, determine whether the alternating current reaches a first threshold condition and / or whether the direct current reaches a second threshold condition;

[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 power-on state.

[0106] Reference Figure 6 , illustrating the control logic of the main relay 12 in the embodiment of the present application.

[0107] Determine whether the main relay 12 is in a power-on state (step S601);

[0108] In step S601, if the main relay 12 is in the power-on state, step S602 is executed to determine whether the AC power reaches a first threshold condition;

[0109] In step S602, if the AC power reaches the first threshold condition, step S603 is executed to determine whether the DC power reaches the second threshold condition;

[0110] In step S602, if the AC power does not reach the first threshold condition, step S604 is executed to control the main relay 12 to be powered off;

[0111] In step S603, if the DC power reaches the second threshold condition, step S605 is executed to maintain the main relay 12 in the powered state;

[0112] In step S603, if the DC power does not reach the second threshold condition, step S604 is executed.

[0113] In some embodiments of the present application, the controller 71 is configured to: when the load element 10 does not need to operate, control the main relay 12 to be powered off, and when the load element 10 is operating, control the main relay 12 to be powered on. This is to adapt to the situation that when the main relay 12 is disconnected, the load elements of the air conditioner, such as the compressor and the fan motor, cannot operate normally 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, a delay is required before the load element 10 is powered on to work, so as to avoid interference with 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 a first threshold condition and is maintained for a period of time, it is determined that the alternating current is in a low voltage state.

[0116] Reference Figure 7 , which explains the control logic for determining that the AC power is in a low voltage state.

[0117] Determine whether the AC power is less than a first preset value (step S701);

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

[0119] In step S703, if the duration of the current state reaches the first preset time, step S704 is executed, the AC power flag is low voltage, that is, the current AC power is in a low voltage state, and the duration is reset to zero. For example, the low voltage bit is Vac_low=1, time=0;

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

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

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

[0123] Reference Figure 8 , which explains the control logic for determining that the DC power is in a low voltage state.

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

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

[0126] In step S803, if the duration of the current state reaches the second preset time, step S804 is executed, the DC power flag is low voltage, that is, the current DC power is in a low voltage state, and the duration is reset to zero. For example, the low voltage bit is Vdc_low=1, time=0;

[0127] In step 703, if the duration of the current state does not reach the second preset time, step S802 is executed.

[0128] In step S801, if the DC power is not less than the second preset value, step S805 is executed, the DC power flag is a non-low voltage bit, and the DC power is not in a low voltage state, and time accumulation is not performed, that is, Vdc_low=0, 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 lasts for a period of time, the main relay 12 is powered off and is not powered on immediately.

[0130] In some implementations of the present embodiment, the load element 10 is specifically configured as a compressor 1. During the process of power failure and power re-application during the operation of the compressor 1, due to the instantaneous power failure and the lack of power input, the power stored in the energy storage capacitor 9 will be quickly consumed before the compressor 1 stops, causing the capacitance across the energy storage capacitor 9 to decrease rapidly. If power is turned on immediately at this time, the peak value of the AC power will be significantly higher than the voltage of the DC power. If the main relay 12 is still in the power-on state, the PTC resistor 11 will be de-energized, which will generate a surge current and impact the hardware devices.

[0131] Based on the low voltage protection judgment logic of the AC power and the low voltage protection judgment logic of the DC power of the air conditioner 100, the present application adds the power-off execution of the main relay 12 and the power-on execution of the main relay 12 after the fault is eliminated to the fault handling mechanism, so as to solve the surge current generated by the sudden drop or rise of voltage and avoid hardware damage.

[0132] The air conditioner 100100 in this embodiment includes an AC power supply 6 for outputting AC power, a rectifier circuit 7 electrically connected to the AC power supply 6 and used to convert AC power into DC power, a PFC circuit 8 electrically connected to the rectifier circuit 7, an energy storage capacitor 9 connected in parallel with the PFC circuit 8, a load element 10 electrically connected to 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. The controller 71 is configured to, after the load element 10 is powered off and before it is powered on again, the AC power supply 6 supplies power, controls the main relay 12 to be in a power-off state, and determines whether the AC power reaches a first threshold condition or whether the DC power reaches a second threshold condition at this time; 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, and a delay is made for a period of time to wait for the energy storage capacitor 9 to be charged, and then 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 abnormality of the power grid when the air conditioner 100 is powered on again after a short power outage is eliminated, thereby avoiding hardware failure.

[0133] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. An air conditioner, characterized in that: AC power supply, used for outputting AC power; a rectifier circuit, electrically connected to the AC power source, for converting the AC power into DC power; A PFC circuit electrically connected to the rectifier circuit; an energy storage capacitor 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, which is provided between the rectifier circuit and the PFC circuit; a main relay, which is provided between the rectifier circuit and the PFC circuit and connected in parallel with the PTC resistor; The controller is configured to: after the load element is powered off and before it is powered on again, the AC power supply supplies power, controls the main relay to be in a power-off state, and determines whether the AC power reaches a first threshold condition or whether the DC power reaches a second threshold condition at this time; 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, and a delay is made 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.

2. The air conditioner according to claim 1, characterized in that: The controller is configured to: when the AC power does not reach a first threshold condition and / or the DC power does not reach a second threshold condition, the main relay is powered off, and the main relay is powered on until the AC power reaches the first threshold condition and the DC power reaches the second threshold condition.

3. The air conditioner according to claim 1, characterized in that: The controller is configured to: when the main relay is in a powered-on state, determine whether the alternating current reaches a first threshold condition or whether the direct current reaches a second threshold condition; When the alternating current does not reach a first threshold condition and / or the direct current does not reach a 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 in a powered-on state, determine whether the alternating current reaches a first threshold condition and / 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, the main relay is controlled to maintain a power-on state.

5. The air conditioner according to claim 1, characterized in that: The controller is configured to: control the main relay to be powered off when the load element does not need to operate, and control the main relay to be powered on when the load element operates.

6. The air conditioner according to claim 1, characterized in that: After the main relay is powered on, a delay of a period of time is required before the load element is powered on to work, so as to avoid interference to part of the power supply when the main relay is powered on.

7. The air conditioner according to claim 1, characterized in that: When the AC power is in a low voltage state or the DC power is in a low voltage state, turning off the load element; After the alternating current and the direct current are no longer in a low voltage state, the load element continues to work.

8. The air conditioner according to claim 7, characterized in that: When the alternating current reaches a 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 direct current reaches the second threshold condition and is maintained for a period of time, it is determined that the direct 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 the instantaneous value of the direct current by a certain value and lasts for a period of time, the main relay is powered off and is no longer powered on immediately.

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