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, when the main relay is in a power-on state, in a current period, judge whether the instantaneous value of the alternating current exceeds a certain threshold value of the direct current, when the instantaneous value of the alternating current exceeds the certain threshold value of the direct current, control the main relay to be powered off, and when the instantaneous value of the alternating current still exceeds the certain threshold value of the direct current in a next period, control the main relay to be powered on, so that the surge current is inhibited by using the dithering action of the main relay before being attracted to a position.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of household appliances, in particular to an air conditioner. BACKGROUND

[0002] With the development of PFC high frequency, the PFC inductance is getting smaller and smaller, and when it is in ultra-high frequency, such as 60k or more, new materials such as SiC diodes need to be used. With the same voltage fluctuation, the smaller the inductance, the greater the surge current generated, and the SiC diode is much weaker than the traditional material diode in terms of surge current resistance. Under the trade-off between the two, the risk of surge damage to the device is increasing, and optimization is needed to reduce the risk.

[0003] The anti-surge circuit commonly used in the air conditioner industry is a combination of a relay and a PTC resistor, as shown in Figure 1 The working principle is: when power is turned on, because the voltage of Vdc is 0 and the peak value of Vac is 310V (for example, the mains is 220V / 50Hz), because of the voltage difference, the capacitor C1 will be charged, and because the resistance of the PTC circuit is small and the voltage difference is large, a large surge current will be generated. At this time, the PTC resistor is inserted, which increases the impedance of the entire circuit and effectively reduces the current size to avoid excessive current exceeding the hardware bearing range. After the capacitor C1 is fully charged, there is no voltage difference between the peak values of Vdc and Vac, so no surge current will be generated, and the main relay can be closed to disconnect the PTC circuit to ensure smooth power supply to the subsequent load.

[0004] The above technical solution can avoid the surge when power is turned on, but the remaining surge current cannot be well inhibited. Specifically, the air conditioner operates in the normal voltage range, but due to external reasons, Vac suddenly rises to 400V (peak value 560V), at which time the voltage is obviously higher than the protection value, and the load element will stop working. At the same time, because the peak value of Vac is much higher than the voltage of Vdc, a large surge current will also be generated.

[0005] Therefore, the present application is proposed. SUMMARY

[0006] The air conditioner provided by the present application determines the power-on and power-off state of the main relay by judging the size of the alternating current and the instantaneous value and the direct current, so as to avoid the short-time surge current generated by using the jitter of the main relay, and to avoid the long-time surge current by using the long-time disconnection of the main relay.

[0007] The air conditioner provided by the present application comprises:

[0008] An alternating current power supply for outputting alternating current;

[0009] a rectifier circuit electrically connected with the AC power supply, configured to convert 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: when the main relay is in a power-on state, in a current period, determine whether the instantaneous value of the AC power exceeds a certain threshold of the DC power, when the instantaneous value of the AC power exceeds the certain threshold of the DC power, control the main relay to be powered off, and in the next period, if the instantaneous value of the AC power does not exceed the certain threshold of the DC power, control the main relay to be powered on, so as to suppress the inrush current by using the pre-attraction damping action of the main relay powered on.

[0016] In some embodiments of the present application, the controller is configured to: when the instantaneous value of the AC power exceeds the certain threshold of the DC power and lasts for a certain time, control the main relay not to be powered on immediately.

[0017] In some embodiments of the present application, the controller is configured to: after the main relay is powered off, only when both the AC power and the DC power recover to the corresponding normal voltage range, the main relay is powered on again.

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

[0019] when the AC power reaches the first threshold condition and the DC power reaches the second threshold condition, it is determined that the inrush current will be generated at this time, and a delay time is set to wait for the energy storage capacitor to be charged, and then the main relay is powered on.

[0020] 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 until the AC power reaches the first threshold condition and the DC power reaches the second threshold condition, the main relay is powered on.

[0021] In some embodiments of the present application, the controller is configured to: when the instantaneous value of the AC power does not exceed the certain threshold of the DC power, control the main relay to be powered on or maintain the power-on state.

[0022] In some embodiments of the present application, 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.

[0023] In some embodiments of the present application, after the main relay is powered on, the load element is powered on to work after a period of time, 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 alternating current is in a low-voltage state or the direct current is in a low-voltage state.

[0025] After the alternating current and the direct current are not in the low-voltage state, the load element continues to work.

[0026] In some embodiments of the present application, the load element at least includes a compressor, a fan and a motor.

[0027] In the above embodiments, the present application provides an air conditioner, which comprises an alternating current power supply for outputting an alternating current, a rectifier circuit electrically connected with the alternating current power supply and used for converting the alternating current into a 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. The controller is configured to, when the main relay is in a powered-on state, determine whether an instantaneous value of the alternating current exceeds a certain threshold value of the direct current in a current period, control the main relay to be powered off when the instantaneous value of the alternating current exceeds the certain threshold value of the direct current, and control the main relay to be powered on in a next period if the instantaneous value of the alternating current still exceeds the certain threshold value of the direct current, so as to suppress inrush current by using a hunting action of the main relay before the main relay is attracted to a position. By determining the power-on and power-off states of the main relay according to the alternating current and the instantaneous value and the size of the direct current, short-time inrush current generated by the hunting action of the main relay is avoided, and hardware damage is avoided. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, hereinafter, a brief introduction will be given to 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 any creative effort on the basis of these drawings.

[0029] Figure 1 is a refrigeration system diagram of an air conditioner provided according to an exemplary embodiment;

[0030] Figure 2 Connection diagram of an air conditioner and a control device according to an exemplary embodiment;

[0031] Figure 3 Hardware configuration block diagram of an air conditioner according to an exemplary embodiment;

[0032] Figure 4 Hardware configuration block diagram of a controller according to an exemplary embodiment;

[0033] Figure 5 Control logic for eliminating inrush current of a controller according to an exemplary embodiment;

[0034] Figure 6 Control logic of a main relay according to an exemplary embodiment;

[0035] Figure 7 Control logic for determining low voltage of AC power according to an exemplary embodiment;

[0036] Figure 8 Control logic for determining low voltage of DC power according to an exemplary embodiment;

[0037] Figure 9 Another control logic for eliminating inrush current of a controller according to an exemplary embodiment;

[0038] Figure 10 Another control logic for eliminating inrush current of a controller according to an exemplary embodiment;

[0039] Figure 11 Hardware circuit diagram of an air conditioner according to an exemplary embodiment;

[0040] Figure 12 Control logic for when AC power suddenly rises to much higher than DC power according to an exemplary embodiment;

[0041] Figure 13 Another control logic for when AC power suddenly rises to much higher than DC power 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] In the following, the application will be described by way of example with reference to the embodiments. It is to be understood that elements, structures and features of one embodiment can be beneficially incorporated in other embodiments without further recitation.

[0048] In the description of the present application, it needs to be understood that the terms "center", "upper", "lower", "front", "back", "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 convenience of describing 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 needs to be understood 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 integrally connected; it can be directly connected, or indirectly connected through an intermediate medium; it can be the communication inside 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 demand.

[0052] The refrigeration system includes a compressor 1, a condenser 2, an expansion valve 3 and an evaporator 4, and 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 drawings) is usually installed at a position of an indoor wall surface or the like, and the indoor cabinet machine (not shown in the drawings) 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 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, using infrared rays or other communication methods. The remote controller is used for various controls of the air conditioner 100 by a user, so as to realize the interaction between the user and the air conditioner 100.

[0062] Referring to Figure 3 , 11The air conditioner 100 provided by the embodiment of the present application comprises an AC power supply 6, a rectifier circuit 7 electrically connected with the AC 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 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 8 and connected in parallel with the PTC resistor 11. The controller 71 is electrically connected with the main relay 12, the load element 10 and the PFC circuit 8 to control the on-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 71 refers to a device capable of generating operation control signals according to instruction operation codes and timing signals to instruct the air conditioner 100 to execute control instructions. For example, in response to the received power-on or power-off instruction issued by the user, the controller 71 can execute operations related to the selected object of the power-on or power-off instruction.

[0065] The embodiment of the present application also provides a hardware structure schematic diagram of the controller 71, as shown in Figure 4 The controller 71 comprises a processor 83, and optionally comprises a memory 82 and a communication interface 8 connected with the processor 83. The processor 83, the memory 82 and the communication interface 8 are connected through a bus 81.

[0066] The processor 83 can be a central processing unit (CPU), a general processor (NP), a digital signal processor (DSP), a microprocessor, a microcontroller, a programmable logic device (PLD) or any combination thereof. The processor 83 can also be any other device with processing function, such as a circuit, a device or a software module. The processor 83 can also comprise a plurality of CPUs, and the processor 83 can be a single-CPU processor 83 or a multi-CPU processor 83. The processor 83 herein can refer to one or more devices, circuits or processing cores for processing data (such as 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 100100 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 4 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] 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 the surge current from being too large and 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 attracted state, the PTC resistor 11 is short-circuited, the entire controller 71 is normally powered, and the power-on state of the main relay 12 is maintained 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 actual application, when the air conditioner is in a normal voltage range, but due to external reasons, the alternating current is increased to a peak value of the alternating current that is much higher than the voltage of the direct current, a large surge current shock can be generated. Because the above-mentioned surge current is generated when the voltage is increased, and the time is very short, at this time, the main relay 12 is still in the power-on state, and therefore the real-time requirement for solving the above-mentioned surge current is very high.

[0073] In some embodiments of the present embodiment, the controller 71 is configured to: when the main relay 12 is in the power-on state, in a current period, determine whether the instantaneous value of the alternating current exceeds a certain threshold value of the direct current, when the instantaneous value of the alternating current exceeds the certain threshold value of the direct current, control the main relay 12 to be powered off, and if the instantaneous value of the alternating current does not exceed the certain threshold value of the direct current in the next period, control the main relay 12 to be powered on, to suppress the surge current by using the jitter action of the main relay 12 before the power-on action of the main relay 12 is in place.

[0074] Compared with the high-voltage protection of the alternating current, the high-voltage protection of the direct current, and the fault elimination logic in the related art, the above-mentioned technical solution has a faster response and can improve the influence of the surge current to a greater extent, fully considers the short-time voltage disturbance and the short-time surge condition, and uses multiple sampling to perform shutdown protection, thereby improving the anti-power disturbance capability of the entire machine while solving the influence of the surge current on the hardware.

[0075] It should be noted that the reason why the above-mentioned technical solution can suppress the current is that the power-on action of the above-mentioned main relay 12 needs time to be in place, and jitter will be generated before the action is in place, and the jitter can be used to effectively suppress the surge current. Moreover, the sampling frequency of the alternating current and the direct current is very fast, and if the alternating current fluctuates for a short time, the current can be suppressed by the action of the main relay 12.

[0076] The surge current is eliminated by the jitter of the main relay 12, mainly to deal with the case of short-time AC current rise, in which case the surge current is not large because the AC exceeds the limit time for a short time. The above technical solution can also avoid misjudgment, and the main relay 12 does not need to be disconnected for a long time in all AC over-limit situations.

[0077] Referring to Figure 12 , the control logic when the AC suddenly rises to much higher than the DC in this application is explained.

[0078] The main relay 12 is in the power-on state (step S1101); in the current period, it is judged whether the instantaneous value of the AC exceeds the instantaneous value of the DC by a certain threshold (step S1102);

[0079] In step S1102, if the instantaneous value of the AC exceeds the instantaneous value of the DC by a certain threshold, step S1103 is executed to control the main relay 12 to be powered off, and the next period is judged whether the instantaneous value of the AC still exceeds the instantaneous value of the DC by a certain threshold (step S1104);

[0080] In step S1104, if the instantaneous value of the AC still exceeds the instantaneous value of the DC by a certain threshold, step S1105 is executed to maintain the power-off state of the main relay 12;

[0081] In step S1104, if the instantaneous value of the AC does not exceed the instantaneous value of the DC by a certain threshold, step S1106 is executed to control the main relay 12 to be attracted;

[0082] In step S1102, if the instantaneous value of the AC does not exceed the instantaneous value of the DC by a certain threshold, step S1107 is executed to maintain the power-on state of the main relay 12.

[0083] In some embodiments of the present embodiment, the controller 71 is configured to control the main relay 12 not to be powered on immediately when the instantaneous value of the AC exceeds the DC by a certain threshold and lasts for a certain time.

[0084] Referring to Figure 13 , another control logic when the AC suddenly rises to much higher than the DC in this application is explained.

[0085] The main relay 12 is in the power-on state (step S1201); in the current period, it is judged whether the instantaneous value of the AC exceeds the instantaneous value of the DC by a certain threshold (step S1202);

[0086] If the instantaneous value of the AC exceeds the instantaneous value of the DC by a certain threshold value, step S1203 is performed to control the main relay 12 to be de-energized, and the next cycle determines whether the instantaneous value of the AC still exceeds the instantaneous value of the DC by the certain threshold value (step S1204) in step S1202;

[0087] If the instantaneous value of the AC still exceeds the instantaneous value of the DC by the certain threshold value, step S1205 is performed to maintain the de-energized state of the main relay 12 in step S1204, and it is determined whether the time during which the instantaneous value of the AC exceeds the instantaneous value of the DC by the certain threshold value reaches a preset time (step S1208) ;

[0088] If the time reaches the preset time, step S1209 is performed to not immediately energize the main relay 12 when the instantaneous value of the AC does not exceed the instantaneous value of the DC by a certain value in step S1208;

[0089] If the time does not reach the preset time, step S1204 is performed in step S1208;

[0090] If the instantaneous value of the AC does not exceed the instantaneous value of the DC by the certain threshold value, step S1206 is performed to control the main relay 12 to be energized in step S1204;

[0091] If the instantaneous value of the AC does not exceed the instantaneous value of the DC by the certain threshold value, step S1207 is performed to maintain the energized state of the main relay 12 in step S1202.

[0092] In the present application, the instantaneous value of the AC and the instantaneous value of the DC are used to control the air conditioner. If the difference between the instantaneous value of the AC and the instantaneous value of the DC is large, the main relay 12 is de-energized. If the difference between the instantaneous value of the AC and the instantaneous value of the DC is restored to a small value in a short time, the main relay 12 is immediately energized. If the difference between the instantaneous value of the AC and the instantaneous value of the DC is maintained to be large for a long time, the main relay 12 is de-energized until the AC and the DC are restored to the normal operating range. Thus, the short-time inrush current is avoided by using the jitter of the main relay 12 when the difference is restored in a short time, and the long-time inrush current is avoided by using the long-time de-energization of the main relay 12 when the difference is maintained to be large for a long time.

[0093] In some embodiments of the present embodiment, the load elements can include a compressor 1, a fan, a motor, various valves, etc. The AC power supply 6 supplies power to the load elements 10 through the rectifier circuit 7, the PFC circuit 8, the PTC resistor 11, and the main relay 12 to maintain the operation of the entire air conditioner.

[0094] In some embodiments of the present embodiment, the load element 10 is specifically configured as the compressor 1, and during the process of power-off and re-power-on of the compressor 1 during operation, due to instantaneous power-off, there is no power input, and the power stored in the energy storage capacitor 9 is quickly consumed before the compressor 1 stops, causing the capacitance at both ends of the energy storage capacitor 9 to quickly decrease, and if power is immediately turned on at this time, due to the fact that the peak value of alternating current is significantly higher than the voltage of direct current, if the main relay 12 is still in the power-on state, the PTC resistor 11 will be powered off, and a surge current will be generated, which will cause an impact on the hardware devices.

[0095] In order to solve the problem that, during the abnormal use test of the load element 10 of the air conditioner 100 in the process of power-off and re-power-on during operation, due to the fact that the peak value of alternating current is significantly higher than the voltage of direct current, if the main relay 12 is still in the power-on state, a surge current will be generated, which will cause an impact on the hardware.

[0096] In some embodiments of the present embodiment, the controller 71 is further configured to, after the main relay 12 is powered off, only when the alternating current and the direct current both recover to the corresponding normal voltage range, the main relay 12 will be powered on again.

[0097] In some embodiments of the present embodiment, the controller 71 is configured to, before the load element 10 is powered on again after being powered off, the alternating current source 6 supplies power, the main relay 12 is controlled to be in a power-off state, and it is judged whether the alternating current reaches a first threshold condition or the direct current reaches a second threshold condition at this time.

[0098] 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 time delay is performed to wait for the charging of the energy storage capacitor 9, and then the main relay 12 is controlled to be powered on.

[0099] 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.

[0100] After the alternating current and the direct current are both not in a low-voltage state, the load element 10 continues to work.

[0101] Referring to Figure 5 , the control logic of the controller 71 for eliminating the surge current in the embodiments of the present application is described.

[0102] 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 judged whether the alternating current reaches a first threshold condition (step S504);

[0103] In step S504, if the alternating current reaches the first threshold condition, step S505 is performed to judge whether the direct current reaches a second threshold condition.

[0104] If the DC voltage reaches the second threshold condition, step S507 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 powered on (step S508)

[0105] If the DC voltage does not reach the second threshold condition, step S506 is performed.

[0106] If the AC voltage does not reach the first threshold condition, step S506 is performed to control the main relay 12 to not be powered on.

[0107] Through the above steps, when the AC voltage reaches the first threshold condition and the DC voltage 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 period of time to charge the energy storage capacitor 9, so that the voltage across the energy storage capacitor 9 is increased, thereby avoiding damage to hardware devices caused by the surge current.

[0108] 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.

[0109] In the present application, the voltage of the AC or DC voltage is judged, and the main relay 12 is powered off when the AC or DC voltage is lower than the corresponding threshold value, so that the PTC resistor 11 is connected in series to the main circuit. If the AC or DC voltage rises to a certain value, the main relay 12 is powered on after a period of time to bypass the PTC resistor 11, so that the load element 10 at the back end of the air conditioner 100 can be normally powered and operated. On the basis of the low-voltage protection logic of the AC and the low-voltage protection logic of the DC and the fault elimination logic, the execution of the powering off of the main relay 12 is increased, and after the fault is eliminated, the execution of the powering on of the main relay 12 is increased, thereby avoiding the impact of the surge current on the hardware devices when the voltage rises, and avoiding the failure of the hardware.

[0110] 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.

[0111] 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 judged whether the AC power reaches a first threshold condition (step S1004);

[0112] In step S1004, if the AC power reaches the first threshold condition, step S1005 is performed to judge whether the DC power reaches a second threshold condition;

[0113] 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)

[0114] In step S1005, if the DC power does not reach the second threshold condition, step S1006 is performed.

[0115] 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).

[0116] 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.

[0117] Referring to Figure 9 , another control logic of the controller 71 for eliminating inrush current in the embodiments of the present application is described.

[0118] 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 judged whether the AC power reaches a first threshold condition (step S904);

[0119] In step S904, if the AC power reaches the first threshold condition, step S905 is performed to judge whether the DC power reaches a second threshold condition;

[0120] 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)

[0121] In step S905, if the DC power does not reach the second threshold condition, step S906 is performed.

[0122] 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.

[0123] 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).

[0124] If the AC power reaches the first threshold condition and the DC power reaches the second threshold condition, step S908 is performed.

[0125] 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.

[0126] 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.

[0127] 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.

[0128] 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.

[0129] 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.

[0130] Referring to Figure 6 , the control logic of the main relay 12 in the embodiments of the present application is described.

[0131] It is determined whether the main relay 12 is in the powered-on state (step S601).

[0132] 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.

[0133] 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.

[0134] 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.

[0135] 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.

[0136] In step S603, if the direct current does not reach the second threshold condition, step S604 is performed.

[0137] 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 because the reactance of the PTC resistor is large when the main relay 12 is disconnected.

[0138] In some embodiments of the present application, after the main relay 12 is powered on, the load element 10 needs to be powered on and work after a period of time, so as to avoid interference to part of the power supply when the main relay 12 is powered on.

[0139] 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 at this time.

[0140] Referring to Figure 7 , the control logic for determining that the alternating current is in a low-voltage state is described.

[0141] It is determined whether the alternating current is less than a first preset value (step S701);

[0142] 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);

[0143] 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.

[0144] In step 703, if the current state duration does not reach the first preset time, step S702 is performed.

[0145] 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 is not accumulated, i.e., Vac_low = 0, and time = 0.

[0146] 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 at this time.

[0147] Referring to Figure 8 , the control logic for determining that the direct current is in a low-voltage state is described.

[0148] determining whether the direct current is less than a second preset value (step S801);

[0149] In step S801, if the direct current is less than the second preset value, step S802 is executed, the time is accumulated, time = time++, and it is determined whether the current state duration reaches the second preset time (step S803);

[0150] In step S803, if the current state duration reaches the second preset time, step S804 is executed, the direct current flag is a low voltage bit, i.e., the current direct current is in a low voltage state, the duration is reset to zero, and an example is that the low voltage bit is Vdc_low = 1 and time = 0.

[0151] In step 703, if the current state duration does not reach the second preset time, step S802 is executed.

[0152] 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 a non-low voltage bit, at this time, the direct current is not in a low voltage state, and the time is not accumulated, i.e., Vdc_low = 0 and time = 0.

[0153] 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 application increases the power-off execution of the main relay 12 and the power-on execution of the main relay 12 after the fault is removed in the fault processing mechanism, so as to solve the inrush current generated due to the sudden drop and rise of the voltage and avoid the damage of the hardware.

[0154] The air conditioner 100 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 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, when the main relay is in a power-on state, in a current period, determine whether an instantaneous value of the alternating current exceeds a certain threshold value of the direct current, when the instantaneous value of the alternating current exceeds the certain threshold value of the direct current, control the main relay to be powered off, and if the instantaneous value of the alternating current still exceeds the certain threshold value of the direct current in a next period, control the main relay to be powered on, so as to utilize the pre-engagement jitter action of the main relay powered on to suppress the inrush current. By determining the alternating current, the instantaneous value and the direct current, the power-on and power-off states of the main relay are determined, so as to utilize the jitter of the main relay to avoid the short-time inrush current and avoid hardware damage.

[0155] 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, include: 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: when the main relay is in the powered-on state, in the current cycle, determine whether the instantaneous value of the AC current exceeds a certain threshold of the DC current; when the instantaneous value of the AC current exceeds a certain threshold of the DC current, control the main relay to de-energize; in the next cycle, if the instantaneous value of the AC current does not exceed a certain threshold of the DC current, control the main relay to energize, so as to use the jitter action before the main relay is energized and engaged to suppress the surge current; When the instantaneous value of the alternating current exceeds a certain threshold of the direct current for a certain period of time, the main relay is controlled not to be energized immediately. After the main relay is de-energized, it will only be energized again after both the AC and DC power have returned to their corresponding normal voltage ranges.

2. The air conditioner according to claim 1, characterized in that, The controller is configured to determine whether the AC current reaches a first threshold condition or the DC current reaches a second threshold condition when the main relay is in a de-energized state. 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.

3. The air conditioner according to claim 2, 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.

4. The air conditioner according to claim 1, characterized in that, The controller is configured to: control the main relay to power on or maintain the power-on state when the instantaneous value of the AC power does not exceed a certain threshold of the DC power.

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 1, characterized in that, The load components include at least a compressor, a fan, and a motor.

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