Air conditioner and control method of air conditioner

Abstract

The invention provides an air conditioner and a control method of the air conditioner, the air conditioner comprises a machine shell, a refrigerant circulation loop, a multi-channel PFC circuit, a temperature monitoring module and a controller, and the controller is configured to control all PFC channels to operate at the same current after the multi-channel PFC circuit is started; acquiring the temperature of an inductance element of each PFC channel in the process that each PFC channel operates with the same current; the current of the corresponding PFC channel is correspondingly adjusted according to the temperature of the inductance element of each PFC channel, so that the temperature of the inductance element of each PFC channel is changed and finally kept consistent, the temperature balance control of the inductance elements of the multiple PFC channels can be realized, the temperature of each inductance element is kept consistent, and the temperature balance control of the inductance elements of the multiple PFC channels is realized. The situation that the PFC circuit is damaged due to the fact that the temperature of the inductance element is too high is avoided, and therefore the stability and reliability of operation of the PFC circuit are improved.

Description

Technical Field

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

[0002] An interleaved PFC (Power Factor Correction) circuit is a circuit that sets multiple PFC channels in parallel and is applicable to two or more PFC channels.

[0003] In the related art, after the PFC circuit is started, the current values ​​of multiple PFC channels are usually controlled to maintain a balance, that is, current equalization control. However, in actual applications, due to certain deviations in the heat dissipation conditions, device parameters and circuit parameters of each inductor element, maintaining the current balance of each PFC channel cannot guarantee that the actual temperature value of each inductor element is consistent. It is easy for one or some inductor elements to have too high a temperature, causing damage to the PFC circuit, and the stability and safety of the PFC circuit operation are low. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art.

[0005] To this end, an object of the present invention is to provide an air conditioner that can achieve temperature balance control of the inductor elements of multiple PFC channels, so that the temperatures of each inductor element remain consistent, avoiding the situation where the PFC circuit is damaged due to excessive temperature of the inductor element, thereby improving the stability and reliability of the PFC circuit operation.

[0006] Therefore, a second object of the present invention is to provide a control method for an air conditioner.

[0007] In order to achieve the above-mentioned purpose, an embodiment of the first aspect of the present invention provides an air conditioner, comprising: a casing; a refrigerant circulation circuit, so that the refrigerant performs a refrigeration cycle in a circuit composed of a compressor, a condenser, an electronic expansion valve, and an evaporator, wherein one of the condenser and the evaporator is an outdoor heat exchanger and the other is an indoor heat exchanger; a multi-channel PFC circuit, connected in parallel between a power input terminal and a power output terminal of the air conditioner, the multi-channel PFC circuit comprising a plurality of parallel PFC channels, for correcting an input current waveform of the air conditioner, wherein each of the PFC channels is provided with an inductor element; a temperature monitoring module, for monitoring the temperature of the inductor element of each of the PFC channels; a controller, wherein the controller is configured to: after the multi-channel PFC circuit is started, control each of the PFC channels to operate with the same current; in the process of each of the PFC channels operating with the same current, obtain the temperature of the inductor element of each of the PFC channels; and adjust the current size of the corresponding PFC channel according to the temperature of the inductor element of each of the PFC channels, so that the temperature of the inductor element of each of the PFC channels changes and finally remains consistent.

[0008] According to the air conditioner of the embodiment of the present invention, by monitoring the actual temperature value of the inductor element, the current distribution coefficient of each PFC channel corresponding thereto is determined, and the current value of the corresponding PFC channel is reasonably distributed according to the current distribution coefficient, so that the temperature value of the inductor element is adjusted according to the distributed current value, so that the actual temperature value of the inductor element tends to be consistent. Therefore, by determining the current distribution coefficient corresponding to the actual temperature value and adjusting the current value of the PFC channel, the temperature balance control of the inductor elements of multiple PFC channels can be achieved, so that the temperature of each inductor element is kept consistent, and the situation that the PFC circuit is damaged due to the excessive temperature of the inductor element is avoided, thereby improving the stability and reliability of the operation of the PFC circuit.

[0009] In some embodiments, when adjusting the current size of the corresponding PFC channel according to the temperature of the inductor element of each PFC channel, the controller is configured to: determine the current distribution coefficient of the corresponding PFC channel according to the temperature of the inductor element of each PFC channel; and adjust the current size of the corresponding PFC channel according to the current distribution coefficient.

[0010] In some embodiments, when adjusting the current size of the corresponding PFC channel according to the current distribution coefficient, the controller is configured to: obtain a total current target value of the multi-channel PFC circuit; obtain target currents of the corresponding PFC channels according to the product of the total current target value and the current distribution coefficients of each of the PFC channels, and adjust the current of each of the PFC channels to the corresponding target current to adjust the current size of the corresponding PFC channel.

[0011] In some embodiments, when determining the current distribution coefficient of the corresponding PFC channel according to the temperature of the inductor element of each PFC channel, if the temperature of the inductor element of the PFC channel is higher, the corresponding current distribution coefficient is lower, and if the temperature of the inductor element of the PFC channel is lower, the corresponding current distribution coefficient is higher.

[0012] In some embodiments, when determining the current distribution coefficient of the corresponding PFC channel according to the temperature of the inductor element of each PFC channel, the controller is configured to: determine the current distribution coefficient of each PFC channel by the following formula, wherein the formula includes:

[0013] R_Ln=(1 / T_Ln) / (1 / T_L1+…+1 / T_LN)

[0014] Wherein, N is the number of the PFC channels, N is an integer greater than 1, n is the current PFC channel, R_Ln is the current distribution coefficient of PFC channel n, T_Ln is the temperature of the inductor element of PFC channel n, and n is a positive integer and n is less than or equal to N.

[0015] In some embodiments, when controlling each of the PFC channels to operate with the same current, the controller is configured to: divide the total current target value of the multi-channel PFC circuit according to the number of the PFC channels to obtain an equalized current; and control each of the PFC channels to operate with the equalized current.

[0016] In some embodiments, when obtaining the total current target value of the multi-channel PFC circuit, the controller is specifically configured to: calculate the total current target value of the multi-channel PFC circuit based on the target value of the DC bus voltage of the air conditioner, the actual value of the DC bus voltage and the grid voltage.

[0017] In some embodiments, before adjusting the current size of the corresponding PFC channel according to the temperature of the inductor element of each PFC channel, the controller is further configured to: determine whether the multi-channel PFC circuit runs to a stable state; if it is determined that the multi-channel PFC circuit runs to a stable state, perform an action of adjusting the current size of the corresponding PFC channel according to the temperature of the inductor element of each PFC channel; if it is determined that the multi-channel PFC circuit does not run to a stable state, temporarily do not perform the action of adjusting the current size of the corresponding PFC channel according to the temperature of the inductor element of each PFC channel, until the multi-channel PFC circuit does not run to a stable state, then perform the action of adjusting the current size of the corresponding PFC channel according to the temperature of the inductor element of each PFC channel.

[0018] In some embodiments, the controller is specifically configured to determine that the multi-channel PFC circuit has run to a stable state when it is determined that the temperature of the inductor element of each PFC channel is continuously and stably within a set temperature range within a set time period.

[0019] In some embodiments, when adjusting the current of the PFC channel to the corresponding target current, the controller is further configured to: determine PWM modulation pulses corresponding to the target currents of multiple PFC channels; and control the on or off duration of the IGBT switch tube according to the PWM modulation pulse to adjust the current size of the PFC channel.

[0020] In order to achieve the above-mentioned object, an embodiment of a second aspect of the present invention provides a control method for an air conditioner, comprising the following steps: after a multi-channel PFC circuit of the air conditioner is started, controlling each PFC channel in the multi-channel PFC circuit to operate with the same current, wherein the multi-channel PFC circuit comprises a plurality of PFC channels connected in parallel, and each of the PFC channels is provided with an inductor element; in the process of each of the PFC channels operating with the same current, acquiring the temperature of the inductor element of each of the PFC channels; and adjusting the current of the corresponding PFC channel according to the temperature of the inductor element of each of the PFC channels, so that the temperature of the inductor element of each of the PFC channels changes and finally remains consistent.

[0021] According to the control method of the air conditioner of the embodiment of the present invention, by monitoring the actual temperature value of the inductor element, the current distribution coefficient of each PFC channel corresponding thereto is determined, and the current value of the corresponding PFC channel is reasonably distributed according to the current distribution coefficient, so that the temperature value of the inductor element is adjusted according to the distributed current value, so that the actual temperature value of the inductor element tends to be consistent. Therefore, by determining the current distribution coefficient corresponding to the actual temperature value and adjusting the current value of the PFC channel, the temperature balance control of the inductor elements of multiple PFC channels can be achieved, so that the temperature of each inductor element is kept consistent, and the situation that the PFC circuit is damaged due to the excessive temperature of the inductor element is avoided, thereby improving the stability and reliability of the operation of the PFC circuit.

[0022] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0024] Figure 1 is a structural schematic diagram of an air conditioner according to an embodiment of the present invention;

[0025] Figure 2 is a hardware configuration block diagram of a controller according to an embodiment of the present invention;

[0026] Figure 3 is a structural block diagram of an air conditioner according to an embodiment of the present invention;

[0027] Figure 4 is a schematic diagram of a control method for a PFC circuit of an air conditioner according to an embodiment of the present invention;

[0028] Figure 5 is a circuit diagram of an air conditioner according to an embodiment of the present invention;

[0029] Figure 6 is a flow chart of a control method of a PFC circuit of an air conditioner according to an embodiment of the present invention;

[0030] Figure 7 is a flow chart of a method for controlling an air conditioner according to an embodiment of the present invention.

[0031] Description of the drawings: air conditioner 100;

[0032] Indoor unit 11; air outlet 12; return air outlet 13; outdoor unit 14;

[0033] Wind deflector 2; control device 200;

[0034] Controller 71;

[0035] Bus 81; Memory 82; Processor 83; Communication interface 84;

[0036] Casing 101 ; refrigerant circulation circuit 102 ; multi-channel PFC circuit 103 ; temperature monitoring module 104 . DETAILED DESCRIPTION

[0037] 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.

[0038] 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 the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0039] The terms "first" and "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, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features.

[0040] 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.

[0041] The embodiment of the present invention provides an air conditioner 100, referring to Figure 1 The air conditioner 100 includes a refrigeration system for exchanging heat with indoor air to meet cooling or heating needs.

[0042] The refrigeration system includes a compressor, a condenser, an expansion valve, and an evaporator, and the air conditioner 100 in the present invention performs a refrigeration cycle of the air conditioner 100 by using the compressor, the condenser, the expansion valve, and the evaporator. The refrigeration cycle includes a series of processes involving compression, condensation, expansion, and evaporation, and supplies refrigerant to the conditioned and heat-exchanged air.

[0043] The compressor 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. The condenser condenses the compressed refrigerant into a liquid phase, and the heat is released to the surrounding environment through the condensation process.

[0044] The expansion valve expands the high-temperature and high-pressure liquid refrigerant condensed in the condenser into a low-pressure liquid refrigerant. The evaporator evaporates the refrigerant expanded in the expansion valve and returns the low-temperature and low-pressure refrigerant gas to the compressor.

[0045] The evaporator can achieve a refrigeration effect by using the latent heat of evaporation of the refrigerant to perform heat exchange with the material to be cooled. In the whole cycle, the air conditioner 100 can adjust the temperature of the indoor space.

[0046] The outdoor unit of the air conditioner 100 refers to a portion of a refrigeration cycle including a compressor and an outdoor heat exchanger, the indoor unit of the air conditioner 100 includes an indoor heat exchanger, and an expansion valve may be provided in the indoor unit or the outdoor unit.

[0047] The indoor heat exchanger and the outdoor heat exchanger function as a condenser or an evaporator. When the indoor heat exchanger functions as a condenser, the air conditioner 100 functions as a heater in a heating mode, and when the indoor heat exchanger functions as an evaporator, the air conditioner 100 functions as a cooler in a cooling mode.

[0048] The air conditioner 100 of the present invention includes an indoor unit 11 and an outdoor unit 14, and the indoor unit 11 and the outdoor unit 14 can be set as an integrated unit or a split unit. The indoor unit 11 can be set as a wall-mounted type, a ceiling unit, a duct unit, etc., and the indoor unit 11 is installed at the top or top of the indoor room.

[0049] Reference Figure 1 Taking an indoor wall mounted unit 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 the indoor unit 11 .

[0050] Taking a split unit as an example, the air conditioner 100 includes an indoor unit 11 and an outdoor unit 14, wherein the outdoor unit 14 is usually arranged outdoors for heat exchange in the indoor environment.

[0051] In addition, 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 operate to realize various predetermined functions of the air conditioner 100. Among them, the air conditioner 100 is also provided with a control device 200. Exemplarily, the control device 200 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.

[0052] The indoor unit 11 of the air conditioner 100 in the embodiment of the present invention is arranged at the top or upper part of the room. Generally speaking, the installation height of the indoor unit 11 is higher than the user activity area. The indoor unit 11 includes a return air port 13 and an air outlet 12 connected to the room. The indoor air enters the indoor unit 11 through the return air port 13 and flows back to the room through the air outlet 12.

[0053] The refrigerant circulation loop in the present invention allows the refrigerant to circulate in a loop consisting of a compressor, a condenser, an expansion valve, and an evaporator. One of the condenser and the evaporator is an outdoor heat exchanger, and the other is an indoor heat exchanger. The indoor heat exchanger is used to exchange heat with the air in the indoor unit 11, and the outdoor unit 14 heat exchanger is used to exchange heat with the air in the outdoor unit 14, thereby achieving the cooling or heating requirements of the air conditioner 100.

[0054] The indoor unit 11 also includes an indoor fan, which is arranged in the indoor heat exchanger near the return air port 13 or the air outlet 12 to deliver the heat-exchanged air to the room. The indoor fan includes multiple gears to change the air outlet speed of the air outlet 12.

[0055] An air guide plate 2 is provided at the position of the air outlet 12. The air guide plate 2 adjusts the outflow direction of the air flowing through the air outlet 12 by changing the relative rotation angle between the air guide plate 2 and the air outlet 12, thereby affecting the indoor air temperature stratification.

[0056] In the embodiment shown in the present invention, the air conditioner 100 further includes a controller 71, which 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 100 to execute the control instruction. For example, in response to a power-on or power-off instruction received from a user, the controller 71 can execute an operation related to the object selected by the power-on or power-off instruction.

[0057] The embodiment of the present invention also provides a hardware structure diagram of a controller 71, as shown in FIG. Figure 2 As shown, the controller 71 includes a processor 83, and optionally, further includes a memory 82 and a communication interface 84 connected to the processor 83. The processor 83, the memory 82 and the communication interface 84 are connected via a bus 81.

[0058] 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, 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).

[0059] 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 magnetic 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 embodiment of the present invention 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 PFC circuit of the air conditioner provided in the embodiment of the present invention.

[0060] The communication interface 84 can be used to communicate with other devices or communication networks (such as Ethernet, radio access network (RAN), wireless local area networks (WLAN), etc. The communication interface 84 can be a module, a circuit, a transceiver or any device that can achieve communication.

[0061] The bus 81 may be a peripheral component interconnect (PCI) 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, Figure 2 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.

[0062] Combine the following Figure 3-Figure 6 An air conditioner 100 according to an embodiment of the present invention is described.

[0063] like Figure 3As shown, the air conditioner 100 of the embodiment of the present invention comprises: a housing 101, a refrigerant circulation loop 102, a multi-channel PFC circuit 103, a temperature monitoring module 104 and a controller 71, wherein the refrigerant circulation loop 102 allows the refrigerant to refrigerate in a loop composed of a compressor, a condenser, an electronic expansion valve and an evaporator, wherein one of the condenser and the evaporator is an outdoor heat exchanger and the other is an indoor heat exchanger; the multi-channel PFC circuit 103 is connected in parallel between the power input end and the power output end of the air conditioner 100, and the multi-channel PFC circuit 103 comprises a plurality of parallel PFC channels for correcting the input current waveform of the air conditioner 100, wherein each PFC channel is provided with an inductor element; the temperature monitoring module 104 is used to monitor the temperature of the inductor element of each PFC channel. In a specific embodiment, the temperature monitoring module 104 can be a temperature sensor or a computing processor, and the computing processor can calculate the temperature of each inductor element according to the relevant operating parameters of each inductor element in each PFC channel.

[0064] The controller 71 is configured to: after the multi-channel PFC circuit 103 is started, control each PFC channel to operate with the same current; obtain the temperature of the inductor element of each PFC channel during the process of each PFC channel operating with the same current; and adjust the current size of the corresponding PFC channel according to the temperature of the inductor element of each PFC channel, so that the temperature of the inductor element of each PFC channel changes and finally remains consistent.

[0065] In the embodiment, after the multi-channel PFC circuit 103 is started, the controller 71 controls each PFC channel to operate with the same current, i.e., current sharing control, to ensure that the currents of multiple PFC channels of the PFC circuit remain balanced; while each PFC channel operates with the same current, the temperature monitoring module 104 is controlled to monitor the temperature of the inductor element of each PFC channel in real time, for example, recorded as T_Ln.

[0066] After determining the temperature T_Ln of the inductor element of each PFC channel, the current of the corresponding PFC channel is adjusted accordingly according to the temperature T_Ln of the inductor element of each PFC channel, so that the temperature T_Ln of the inductor element of each PFC channel changes until the temperature T_Ln of the inductor element of each PFC channel is finally kept consistent, so that the temperature balance control of the inductor element of each PFC channel can be achieved, and the damage of the PFC circuit caused by the excessive temperature of the inductor element is avoided, thereby improving the stability and reliability of the operation of the PFC circuit.

[0067] According to the air conditioner 100 of the embodiment of the present invention, the current distribution coefficient of each PFC channel corresponding to the actual temperature value of the inductor element is determined by monitoring the actual temperature value of the inductor element, and the current value of the corresponding PFC channel is reasonably distributed according to the current distribution coefficient, so that the temperature value of the inductor element is adjusted according to the distributed current value, so that the actual temperature value of the inductor element tends to be consistent. Therefore, by determining the current distribution coefficient corresponding to the actual temperature value and adjusting the current value of the PFC channel, the temperature balance control of the inductor elements of multiple PFC channels can be achieved, so that the temperature of each inductor element is kept consistent, and the situation that the PFC circuit is damaged due to the excessive temperature of the inductor element is avoided, thereby improving the stability and reliability of the operation of the PFC circuit.

[0068] In some embodiments, when adjusting the current size of the corresponding PFC channel according to the temperature of the inductor element of each PFC channel, the controller 71 is configured to: determine the current distribution coefficient of the corresponding PFC channel according to the temperature of the inductor element of each PFC channel; and adjust the current size of the corresponding PFC channel according to the current distribution coefficient.

[0069] In an embodiment, a current distribution coefficient of a corresponding PFC channel is determined according to the temperature of the inductor element of each PFC channel, for example, recorded as R_Ln, so that the current magnitudes of multiple PFC channels are reasonably distributed according to the current distribution coefficient R_Ln, and the current magnitudes of the corresponding PFC channels are adjusted in real time, for example, recorded as Iacn, so that the temperature T_Ln of the inductor element of each PFC channel can be balanced and controlled, so that the temperature of each inductor element is kept consistent, and damage to the PFC circuit caused by excessive temperature of the inductor element is avoided, thereby improving the stability and reliability of the operation of the PFC circuit.

[0070] like Figure 4 and Figure 5 FIG. 1 is a circuit diagram of an air conditioner according to an embodiment of the present invention. The air conditioner 100 is provided with a plurality of PFC channels in parallel. Figure 4 and Figure 5The example shown in the figure includes three PFC channels, each PFC channel is provided with an inductor element and an IGBT (Insulated Gate Bipolar Transistor) switch tube connected in series therewith, each inductor element is recorded as, for example, inductor L1, inductor L2 and inductor L3, and the corresponding IGBT switch tubes are recorded as IGBT1, IGBT2 and IGBT3. After the controller 71 controls the three PFC channels to operate at the same current, the actual temperature value of the inductor L1 monitored in real time by the temperature monitoring module 104 is obtained, for example, recorded as T_L1, the actual temperature value of the inductor L2 is recorded as T_L2, and the actual temperature value of the inductor L3 is recorded as T_L3; the current distribution coefficient R_L1 is adjusted in real time according to the actual temperature value T_L1, the current distribution coefficient R_L2 is adjusted in real time according to the actual temperature value T_L2, and the current distribution coefficient R_L3 is adjusted in real time according to the actual temperature value T_L3. The current distribution coefficient R_L3 is set; the current size Iac1 of the PFC channel is adjusted in real time according to the current distribution coefficient R_L1, the current size Iac2 of the PFC channel is adjusted in real time according to the current distribution coefficient R_L2, and the current size Iac3 of the PFC channel is adjusted in real time according to the current distribution coefficient R_L3, so as to control the on or off time of the IGBT1 switch tube according to the current size Iac1, control the on or off time of the IGBT2 switch tube according to the current size Iac2, and control the on or off time of the IGBT3 switch tube according to the current size Iac3, until the actual temperature value T_L1 of the inductor L1, the actual temperature value T_L2 of the inductor L2, and the actual temperature value T_L3 of the inductor L3 are kept consistent.

[0071] In some embodiments, when adjusting the current size of the corresponding PFC channel according to the current distribution coefficient, the controller 71 is configured to: obtain a total current target value of the multi-channel PFC circuit; obtain the target current of the corresponding PFC channel according to the product of the total current target value and the current distribution coefficient of each PFC channel, and adjust the current of each PFC channel to the corresponding target current to adjust the current size of the corresponding PFC channel.

[0072] In an embodiment, when multiple PFC channels operate at the same current, the controller 71 obtains a target value of the DC bus voltage of the PFC circuit, for example, recorded as Vdc_ref and an actual value of the DC bus voltage, for example, recorded as Vdc, and calculates a voltage error between the target value Vdc_ref of the DC bus voltage and the actual value Vdc of the DC bus voltage. The voltage controller performs PI (proportional, integral) voltage control on the target value Vdc_ref of the DC bus voltage and the actual value Vdc of the DC bus voltage according to the voltage error to obtain an output current value, and calculates the product of the output current value and the absolute value of the grid voltage Vac, i.e., |Vac|, and uses the product as the total current target value of the multi-channel PFC circuit, for example, recorded as Iac_ref.

[0073] After obtaining the total current target value Iac_ref of the multi-channel PFC circuit, the product of the total current target value Iac_ref and the current distribution coefficient of the PFC channel, i.e., R_Ln, is calculated respectively, and the current Iacn_ref of the corresponding PFC channel is obtained accordingly. The current difference between the total current target value Iac_ref and the current target value of each PFC channel, i.e., Iacn_ref, is calculated respectively. The current controller of each channel performs PI current control on the total current target value Iac_ref and the current target value Iacn_ref of each PFC channel according to the current difference, and adjusts the current of the PFC channel to the corresponding target current. By determining the target current value Iacn_ref of each PFC channel, the current of the channel can be reasonably distributed according to the current target value Iacn_ref of each PFC channel.

[0074] by Figure 4For example, the PFC circuit sets three PFC channels in parallel, and the target current distribution coefficients include R_L1, R_L2 and R_L3. The products of the total current target value Iac_ref and the current distribution coefficients R_L1, R_L2 and R_L3 are calculated respectively, and the current target values ​​Iac1_ref, Iac2_ref and Iac3_ref of the corresponding PFC channels are obtained, that is, Iac1_ref=R_L1×Iac_ref, Iac2_ref=R_L2×Iac_ref, Iac3_ref=R_L3×Iac_ref, and the current control Current controller 1 performs PI current control according to the current error Iac1_ref-Iac1, and adjusts the current Iac1 of the PFC channel in real time until it reaches the corresponding target current Iac1_ref; current controller 2 performs PI current control according to the current error Iac2_ref-Iac2, and adjusts the current Iac2 of the PFC channel in real time until it reaches the corresponding target current Iac2_ref; current controller 3 performs PI current control according to the current error Iac3_ref-Iac3, and adjusts the current Iac3 of the PFC channel in real time until it reaches the corresponding target current Iac3_ref.

[0075] In some embodiments, when determining the current distribution coefficient of the corresponding PFC channel according to the temperature of the inductor element of each PFC channel, if the temperature of the inductor element of the PFC channel is higher, the corresponding current distribution coefficient is lower, and if the temperature of the inductor element of the PFC channel is lower, the corresponding current distribution coefficient is higher.

[0076] In the embodiment, after determining the temperature T_Ln of the inductor elements in the plurality of PFC channels, the current distribution coefficient R_Ln of the corresponding PFC channel is adjusted according to the temperature T_Ln of the inductor element, and if the temperature T_Ln of the inductor element of the PFC channel is larger, the corresponding current distribution coefficient R_Ln is smaller, and if the temperature T_Ln of the inductor element of the PFC channel is smaller, the corresponding current distribution coefficient R_Ln is larger, so as to achieve temperature balance of the inductor elements of the plurality of PFC channels. That is, the temperature T_Ln of the inductor element of each PFC channel is in inverse proportion to the corresponding current distribution coefficient R_Ln.

[0077] In some embodiments, when determining the current distribution coefficient of the corresponding PFC channel according to the temperature of the inductor element of each PFC channel, the controller 71 is configured to: determine the current distribution coefficient of each PFC channel by the following formula, which includes:

[0078] R_Ln=(1 / T_Ln) / (1 / T_L1+…+1 / T_LN)

[0079] Wherein, N is the number of PFC channels, N is an integer greater than 1, n is the current PFC channel, R_Ln is the current distribution coefficient of PFC channel n, T_Ln is the temperature of the inductor element of PFC channel n, and n is a positive integer and n is less than or equal to N.

[0080] In an embodiment, after determining the temperature T_Ln of the inductor elements in the plurality of PFC channels, the temperature T_Ln of the inductor elements is substituted into a calculation formula of the current distribution coefficient R_Ln=(1 / T_Ln) / (1 / T_L1+…+1 / T_LN), thereby obtaining the current distribution coefficient R_Ln of the corresponding PFC channel.

[0081] by Figure 4 For example, the number of PFC channels is N=3, the actual temperature value of inductor L1 is T_L1, the actual temperature value of inductor L2 is T_L2, and the actual temperature value of inductor L3 is T_L3. The current distribution coefficient calculation formulas corresponding to each PFC channel are as follows:

[0082] R_L1=(1 / T_L1) / (1 / T_L1+1 / T_L2+1 / T_L3);

[0083] R_L2=(1 / T_L2) / (1 / T_L1+1 / T_L2+1 / T_L3);

[0084] R_L3=(1 / T_L3) / (1 / T_L1+1 / T_L2+1 / T_L3);

[0085] And R_L1+R_L2+R_L3=1.

[0086] Under the condition that the total current target value Iac_ref of the PFC circuit remains unchanged, the current distribution coefficients R_L1, R_L2 and R_L3 of the PFC channels are distributed to achieve reasonable distribution of the current magnitude Iacn of each channel.

[0087] In some embodiments, when controlling each PFC channel to operate with the same current, the controller 71 is configured to: divide the total current target value of the multi-channel PFC circuit according to the number of PFC channels to obtain an equal current; and control each PFC channel to operate with the equal current.

[0088] In an embodiment, after the PFC circuit is started, the controller 71 determines the number N of PFC channels, and evenly divides the total current target value Iac_ref of the PFC circuit according to the number N of PFC channels to obtain an evenly divided current, thereby controlling each PFC channel to operate with the evenly divided current.

[0089] like Figure 4 and Figure 5As shown, the number of PFC channels N=3, the total current target value Iac_ref of the PFC circuit is evenly divided to obtain an evenly divided current, that is, Iac1=Iac2=Iac3=Iac_ref / 3, and the three PFC channels are controlled to operate with the above evenly divided current.

[0090] In some embodiments, when obtaining the total current target value of the multi-channel PFC circuit, the controller 71 is specifically configured to calculate the total current target value of the multi-channel PFC circuit according to the target value of the DC bus voltage of the air conditioner, the actual value of the DC bus voltage and the grid voltage. The grid voltage is the power supply voltage of the AC grid external to the air conditioner.

[0091] In an embodiment, when multiple PFC channels operate at the same current, the controller 71 obtains the target value of the DC bus voltage of the PFC circuit, for example, recorded as Vdc_ref, the actual value of the DC bus voltage, for example, recorded as Vdc, the grid voltage, for example, recorded as Vac, and the total current target value, for example, recorded as Iac_ref. Thus, the total current target value Iac_ref of the multi-channel PFC circuit can be calculated based on the target value Vdc_ref of the DC bus voltage of the air conditioner, the actual value Vdc of the DC bus voltage, and the grid voltage Vac.

[0092] In some embodiments, before adjusting the current size of the corresponding PFC channel according to the temperature of the inductor element of each PFC channel, the controller 71 is further configured to: determine whether the multi-channel PFC circuit runs to a stable state; if it is determined that the multi-channel PFC circuit runs to a stable state, then execute the action of adjusting the current size of the corresponding PFC channel according to the temperature of the inductor element of each PFC channel; if it is determined that the multi-channel PFC circuit does not run to a stable state, then temporarily do not execute the action of adjusting the current size of the corresponding PFC channel according to the temperature of the inductor element of each PFC channel, until the multi-channel PFC circuit runs to a stable state, then execute the action of adjusting the current size of the corresponding PFC channel according to the temperature of the inductor element of each PFC channel.

[0093] In an embodiment, before adjusting the current of the corresponding PFC channel according to the temperature of the inductor element of each PFC channel, it is first determined whether the multi-channel PFC circuit runs to a stable state. If the multi-channel PFC circuit runs to a stable state, an action of adjusting the current of the corresponding PFC channel according to the temperature T_Ln of the inductor element of each PFC channel is performed; if the multi-channel PFC circuit does not run to a stable state, the action of adjusting the current of the corresponding PFC channel according to the temperature T_Ln of the inductor element of each PFC channel is temporarily not performed until the multi-channel PFC circuit runs to a stable state, and then the action of adjusting the current of the corresponding PFC channel according to the temperature T_Ln of the inductor element of each PFC channel is performed. Therefore, when the system is in a stable state, the detection result of the temperature parameter of each channel is ensured to be more accurate, and the result of the subsequent calculation of the current distribution coefficient is also made more accurate, which is conducive to more accurate adjustment of the current of each channel, so that the temperature control of the inductor element of each channel is more accurate, and the stability of the PFC circuit is fully guaranteed.

[0094] In some embodiments, when it is determined that the temperature of the inductor element of each PFC channel is continuously and stably within a set temperature range within a set time period, it is determined that the multi-channel PFC circuit has run to a stable state.

[0095] In the embodiment, since the temperature T_Ln of the inductor element of each PFC channel usually changes very slowly, it is necessary to wait until the system runs stably before adjusting the current distribution coefficient R_Ln. Therefore, whether the PFC circuit runs to a stable state is judged according to whether the temperature T_Ln of the inductor element of each PFC channel is stable. When the temperature T_Ln of the inductor element of each PFC channel is continuously and stably within a set temperature range within a set time period, it is considered that the temperature T_Ln of the inductor element of each PFC channel is relatively stable, and it is determined that the multi-channel PFC circuit has run to a stable state; when the temperature T_Ln of the inductor element of each PFC channel is not continuously and stably within the set temperature range within the set time period, it is considered that the temperature T_Ln of the inductor element of each PFC channel changes greatly, and it is determined that the multi-channel PFC circuit has not run to a stable state.

[0096] In some embodiments, when adjusting the current of the PFC channel to the corresponding target current, the controller 71 is further configured to: determine the PWM modulation pulses corresponding to the target current values ​​of the multiple PFC channels; and control the on or off time of the IGBT switch tube according to the PWM modulation pulse to adjust the current size of the PFC channel.

[0097] In an embodiment, after the current controller of each channel performs PI current control on the total current target value Iac_ref and the current target value of each PFC channel, i.e., Iacn_ref, according to the current difference, the current error output by the current controller of each channel is compensated according to the grid voltage Vac. For example, the current error output by the current controller of each channel is compensated according to the absolute value |Vac| of the grid voltage Vac and the compensation coefficient k to determine the duty cycle of multiple channels, for example, recorded as dn. After comparing the duty cycle dn of the multiple channels with the carrier, the corresponding PWM modulation pulse is determined, for example, recorded as PWMn. The on or off time of the IGBT switch tube is controlled according to the PWM modulation pulse PWMn, and the current size of the PFC channel is adjusted in real time to achieve the temperature consistency of the inductor element of each PFC channel of the multiple PFC channels, thereby improving the reliability of the PFC circuit.

[0098] by Figure 4 and Figure 5 For example, the grid voltage Vac compensates the current error Iac1_ref-Iac1 output by the current controller 1, determines the corresponding duty cycle d1, and compares the duty cycle d1 with the carrier to determine the corresponding PWM modulation pulse PWM1. According to PWM1, the on or off time of the IGBT1 switch tube is controlled to adjust the current value Iac1 of the PFC channel; the grid voltage Vac compensates the current error Iac2_ref-Iac2 output by the current controller 2, determines the corresponding duty cycle d2, and compares the duty cycle d2 with the carrier to determine the corresponding PWM modulation pulse PWM2. According to PWM2 Control the on or off time of the IGBT2 switch tube, and adjust the current value Iac2 of the PFC channel; the grid voltage Vac compensates the current error Iac3_ref-Iac3 output by the current controller 3, and determines the corresponding duty cycle d3. After comparing the duty cycle d3 with the carrier, the corresponding PWM modulation pulse is determined to be PWM3. According to the PWM modulation pulse PWM3, the on or off time of the IGBT3 switch tube is controlled, and the current value Iac3 of the PFC channel is adjusted to ensure that the actual temperature value T_L1 of the inductor L1, the actual temperature value T_L2 of the inductor L2 and the actual temperature value T_L3 of the inductor L2 remain consistent.

[0099] Reference below Figure 6 The control method of the PFC circuit of the air conditioner according to the embodiment of the present invention is described by way of example.

[0100] like Figure 6 As shown, the control method of the PFC circuit of the air conditioner according to the embodiment of the present invention at least includes steps S11 to S24.

[0101] Step S11, the multi-channel PFC circuit is started.

[0102] Step S12, dividing the target total current value of the multi-channel PFC circuit according to the number of PFC channels to obtain an evenly distributed current; and controlling each PFC channel to operate with the evenly distributed current.

[0103] Step S13, obtaining actual temperature values ​​of inductor elements in multiple PFC channels.

[0104] Step S14: if the temperature of the inductor element of the PFC channel is lower, the corresponding current distribution coefficient is larger.

[0105] Step S15: If the temperature of the inductor element of the PFC channel is higher, the corresponding current distribution coefficient is lower.

[0106] Step S16, determining whether the temperature of the inductor element of each PFC channel is continuously and stably within a set temperature range within a set time period, if so, executing step S17; otherwise, executing step S18.

[0107] Step S17, determining that the multi-channel PFC circuit has run to a stable state.

[0108] Step S18: the multi-channel PFC circuit does not run to a stable state.

[0109] Step S19: temporarily not performing the action of adjusting the current magnitude of the corresponding PFC channel according to the temperature of the inductor element of each PFC channel.

[0110] Step S20 , performing an action of adjusting the current magnitude of the corresponding PFC channel according to the temperature of the inductor element of each PFC channel.

[0111] Step S21, obtaining a total current target value of a multi-channel PFC circuit.

[0112] Step S22, calculating the product of the total current target value and the current distribution coefficient of the PFC channel, and obtaining the target current of the corresponding PFC channel.

[0113] Step S23, determining PWM modulation pulses corresponding to target current values ​​of multiple PFC channels.

[0114] Step S24, controlling the on or off time of the IGBT switch tube according to the PWM modulation pulse to adjust the current value of the PFC channel.

[0115] According to the air conditioner 100 of the embodiment of the present invention, the current distribution coefficient of each PFC channel corresponding to the actual temperature value of the inductor element is determined by monitoring the actual temperature value of the inductor element, and the current value of the corresponding PFC channel is reasonably distributed according to the current distribution coefficient, so that the temperature value of the inductor element is adjusted according to the distributed current value, so that the actual temperature value of the inductor element tends to be consistent. Therefore, by determining the current distribution coefficient corresponding to the actual temperature value and adjusting the current value of the PFC channel, the temperature balance control of the inductor elements of multiple PFC channels can be achieved, so that the temperature of each inductor element is kept consistent, and the situation that the PFC circuit is damaged due to the excessive temperature of the inductor element is avoided, thereby improving the stability and reliability of the operation of the PFC circuit.

[0116] Combine the following Figure 7 The control method of the air conditioner according to the embodiment of the present invention is described by way of example. The control method of the air conditioner can be used for the air conditioner described in any one of the above embodiments of the present invention.

[0117] like Figure 7 As shown, the air conditioner control method according to the embodiment of the present invention at least includes steps S1 to S3.

[0118] Step S1, after the multi-channel PFC circuit of the air conditioner is started, each PFC channel in the multi-channel PFC circuit is controlled to operate with the same current, wherein the multi-channel PFC circuit includes a plurality of parallel PFC channels, and each PFC channel is provided with an inductor element.

[0119] In an embodiment, after the multi-channel PFC circuit of the air conditioner is started, each PFC channel in the multi-channel PFC circuit is controlled to operate with the same current, that is, current sharing control, to ensure that the current of each PFC channel in the multi-channel PFC circuit remains balanced.

[0120] Step S2: when each PFC channel is running at the same current, the temperature of the inductor element of each PFC channel is obtained.

[0121] In an embodiment, when each PFC channel operates with the same current, the temperature monitoring module is controlled to monitor the temperature of the inductor element of each PFC channel in the multiple PFC channels in real time, for example, recorded as T_Ln.

[0122] Step S3, adjusting the current of the corresponding PFC channel according to the temperature of the inductor element of each PFC channel, so that the temperature of the inductor element of each PFC channel changes and finally remains consistent.

[0123] In an embodiment, after determining the temperature T_Ln of the inductor element of each PFC channel among the multiple PFC channels, the current distribution coefficients of the multiple PFC channels are adjusted in real time according to the temperature T_Ln of the inductor element of each PFC channel, for example, recorded as R_Ln, so as to reasonably distribute the current values ​​of the multiple PFC channels according to the current distribution coefficient R_Ln. Specifically, after determining the current distribution coefficient R_Ln, the current of the corresponding PFC channel is adjusted in real time according to the current distribution coefficient R_Ln, for example, recorded as Iacn, and the on or off time of the IGBT switch tube is controlled according to the current Iacn of the corresponding PFC channel until the temperature T_Ln of the inductor element of each PFC channel is consistent, so that the temperature T_Ln of the inductor element of each PFC channel can be balanced and controlled, so as to avoid damage to the PFC circuit caused by excessively high temperature of the inductor element, thereby improving the stability and reliability of the operation of the PFC circuit.

[0124] It should be noted that when controlling the air conditioner, the specific implementation method of the control method of the air conditioner is similar to the specific implementation method of the above-mentioned air conditioner of the present invention. Therefore, for a detailed exemplary description of the control method of the air conditioner, please refer to the aforementioned description of the air conditioner. In order to reduce redundancy, it will not be repeated here.

[0125] According to the control method of the air conditioner of the embodiment of the present invention, by monitoring the actual temperature value of the inductor element, the current distribution coefficient of each PFC channel corresponding thereto is determined, and the current value of the corresponding PFC channel is reasonably distributed according to the current distribution coefficient, so that the temperature value of the inductor element is adjusted according to the distributed current value, so that the actual temperature value of the inductor element tends to be consistent. Therefore, by determining the current distribution coefficient corresponding to the actual temperature value and adjusting the current value of the PFC channel, the temperature balance control of the inductor elements of multiple PFC channels can be achieved, so that the temperature of each inductor element is kept consistent, and the situation that the PFC circuit is damaged due to the excessive temperature of the inductor element is avoided, thereby improving the stability and reliability of the operation of the PFC circuit.

[0126] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example.

[0127] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. An air conditioner, characterized in that: include: chassis; A refrigerant circulation loop, wherein the refrigerant performs a refrigeration cycle in a loop consisting of a compressor, a condenser, an electronic expansion valve, and an evaporator, wherein one of the condenser and the evaporator is an outdoor heat exchanger and the other is an indoor heat exchanger; a multi-channel PFC circuit connected in parallel between a power input terminal and a power output terminal of the air conditioner, wherein the multi-channel PFC circuit comprises a plurality of parallel PFC channels for correcting an input current waveform of the air conditioner, wherein each of the PFC channels is provided with an inductor element; A temperature monitoring module, used to monitor the temperature of the inductor element of each PFC channel; A controller, the controller being configured to: After the multi-channel PFC circuit is started, controlling each of the PFC channels to operate with the same current; When each of the PFC channels is operated at the same current, obtaining the temperature of the inductor element of each of the PFC channels; The current magnitude of the corresponding PFC channel is adjusted according to the temperature of the inductor element of each PFC channel, so that the temperature of the inductor element of each PFC channel changes and finally remains consistent.

2. The air conditioner according to claim 1, characterized in that: When adjusting the current of the corresponding PFC channel according to the temperature of the inductor element of each PFC channel, the controller is configured as follows: Determining a current distribution coefficient of a corresponding PFC channel according to a temperature of an inductor element of each of the PFC channels; The current magnitude of the corresponding PFC channel is adjusted according to the current distribution coefficient.

3. The air conditioner according to claim 2, characterized in that: When adjusting the current size of the corresponding PFC channel according to the current distribution coefficient, the controller is configured to: Obtaining a total current target value of the multi-channel PFC circuit; According to the product of the total current target value and the current distribution coefficient of each PFC channel, the target current of the corresponding PFC channel is obtained respectively; The current of each of the PFC channels is adjusted to the corresponding target current, so as to adjust the current magnitude of the corresponding PFC channel.

4. The air conditioner according to claim 2, characterized in that: When determining the current distribution coefficient of the corresponding PFC channel according to the temperature of the inductor element of each PFC channel, if the temperature of the inductor element of the PFC channel is greater, the corresponding current distribution coefficient is smaller, and if the temperature of the inductor element of the PFC channel is smaller, the corresponding current distribution coefficient is larger.

5. The air conditioner according to claim 2, characterized in that: When determining the current distribution coefficient of the corresponding PFC channel according to the temperature of the inductor element of each PFC channel, the controller is configured to: determine the current distribution coefficient of each PFC channel by the following formula, and the formula includes: R_Ln=(1 / T_Ln) / (1 / T_L1+…+1 / T_LN) Wherein, N is the number of the PFC channels, N is an integer greater than 1, n is the current PFC channel, R_Ln is the current distribution coefficient of PFC channel n, T_Ln is the temperature of the inductor element of PFC channel n, and n is a positive integer and n is less than or equal to N.

6. The air conditioner according to claim 3, characterized in that: When controlling each of the PFC channels to operate at the same current, the controller is configured as follows: Dividing the total current target value of the multi-channel PFC circuit equally according to the number of the PFC channels to obtain an equally divided current; Each of the PFC channels is controlled to operate with the shared current.

7. The air conditioner according to claim 3, characterized in that: When obtaining the total current target value of the multi-channel PFC circuit, the controller is specifically configured to: calculate the total current target value of the multi-channel PFC circuit according to the target value of the DC bus voltage of the air conditioner, the actual value of the DC bus voltage and the grid voltage.

8. The air conditioner according to claim 1, characterized in that: Before adjusting the current of the corresponding PFC channel according to the temperature of the inductor element of each PFC channel, the controller is further configured to: Determining whether the multi-channel PFC circuit operates to a stable state; If it is determined that the multi-channel PFC circuit runs to a stable state, an action of adjusting the current of the corresponding PFC channel according to the temperature of the inductor element of each PFC channel is performed; If it is determined that the multi-channel PFC circuit has not run to a stable state, the action of adjusting the current size of the corresponding PFC channel according to the temperature of the inductor element of each PFC channel is not performed temporarily until the multi-channel PFC circuit runs to a stable state, and then the action of adjusting the current size of the corresponding PFC channel according to the temperature of the inductor element of each PFC channel is performed.

9. The air conditioner according to claim 8, characterized in that: The controller is specifically configured as follows: When it is determined that the temperature of the inductor element of each of the PFC channels is continuously and stably within the set temperature range within the set time period, it is determined that the multi-channel PFC circuit has run to a stable state.

10. A method for controlling an air conditioner, characterized in that: The following steps are involved: After the multi-channel PFC circuit of the air conditioner is started, each PFC channel in the multi-channel PFC circuit is controlled to operate with the same current, wherein the multi-channel PFC circuit includes a plurality of PFC channels connected in parallel, and each of the PFC channels is provided with an inductor element; When each of the PFC channels is operated at the same current, obtaining the temperature of the inductor element of each of the PFC channels; The current magnitude of the corresponding PFC channel is adjusted according to the temperature of the inductor element of each PFC channel, so that the temperature of the inductor element of each PFC channel changes and finally remains consistent.

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