Air conditioner

Abstract

The air conditioner comprises a refrigerant circulation loop, a current detection device and a controller, and the controller is connected with the current detection device and is configured to obtain three-phase current; determining the angular frequency of the three-phase current; and judging whether the phase sequence of the compressor is correct based on the angular frequency. The angular frequency of the three-phase current of the compressor can be determined by collecting the three-phase current signal of the compressor within the full rotating speed range of the compressor, so that whether the phase sequence of the compressor is correct or not can be judged according to positive and negative of the angular frequency without voltage sampling, meanwhile, the phase sequence is judged by directly determining an angular frequency symbol without complex calculation, and the accuracy of the phase sequence is improved. And the low-speed failure problem does not exist, and the phase sequence judgment accuracy is high.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioners, and more particularly to an air conditioner. Background Art

[0002] In a variable-frequency air-conditioning system, the phase-sequence connection between a variable-frequency driver and a compressor is usually completed manually. However, this method highly depends on the experience and technical level of the operator, and it is easy to cause incorrect phase-sequence connection due to human error, resulting in the reverse rotation of the compressor and ultimately the problem of equipment damage. To solve the above problems, in the prior art, the three-phase voltage and current of the compressor can be collected, and the back electromotive force difference can be calculated to determine whether the phase sequence is correct.

[0003] However, this method requires simultaneous sampling of voltage and current, and the calculation of the back electromotive force difference, which requires three variables: voltage, current, and electromotive force. The algorithm is complex. At the same time, the electromotive force is small during low-speed operation of the compressor, the detection accuracy is low, and the accuracy of phase-sequence judgment is poor. 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, which can determine the angular frequency of the three-phase current of the compressor by collecting the three-phase current signals of the compressor in the full speed range of the compressor, so as to determine whether the phase sequence of the compressor is correct according to the positive or negative of the angular frequency, without voltage sampling. At the same time, the phase sequence is directly determined by determining the angular frequency symbol, without complex calculation, and there is no low-speed failure problem, and the accuracy of phase-sequence judgment is relatively high.

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

[0007] To achieve the above object, an embodiment of the first aspect of the present invention provides an air conditioner, which includes: a refrigerant circulation circuit for enabling the refrigerant to perform a refrigeration cycle in a circuit composed of a compressor, a condenser, a throttling component, an evaporator, and a four-way valve, where one of the condenser and the evaporator is an outdoor heat exchanger, and the other is an indoor heat exchanger; a current detection device for collecting the three-phase current passing through the compressor; and a controller connected to the current detection device, where the controller is configured to: acquire the three-phase current; determine the angular frequency of the three-phase current; and judge whether the phase sequence of the compressor is correct based on the angular frequency.

[0008] According to the air conditioner of the embodiment of the present invention, within the full speed range of the compressor, by collecting the three-phase current signals of the compressor, the angular frequency of the three-phase current of the compressor can be determined. Thus, it is possible to judge whether the phase sequence of the compressor is correct according to the positive or negative of the angular frequency, without the need for voltage sampling. At the same time, by directly determining the angular frequency symbol to judge the phase sequence, complex calculations are not required, and there is no low-speed failure problem, and the accuracy of phase sequence judgment is relatively high.

[0009] In some embodiments, when determining the angular frequency of the three-phase current, the controller is configured to: perform a static coordinate system transformation and a rotating coordinate system transformation on the three-phase current to determine the actual angle of the three-phase current in the static coordinate system and the estimated angle of the three-phase current in the rotating coordinate system; determine the target current corresponding to the three-phase current based on the actual angle and the estimated angle; determine the angular frequency of the three-phase current based on the target current.

[0010] The above technical solution has the following beneficial effects: By performing coordinate transformation on the three-phase current to determine the actual angle and the estimated angle of the three-phase current in the coordinate system, high-precision measurement of the angular frequency of the three-phase current can be achieved.

[0011] In some embodiments, when determining the target current corresponding to the three-phase current based on the actual angle and the estimated angle, the controller is configured to: obtain the angle difference between the actual angle and the estimated angle; determine the target current corresponding to the three-phase current based on the angle difference.

[0012] The above technical solution has the following beneficial effects: By calculating the difference value between the actual angle and the estimated angle to determine the target current, it is convenient to dynamically adjust the angle error and output a stable angular frequency to reflect the phase sequence direction.

[0013] In some embodiments, when determining the target current corresponding to the three-phase current based on the angle difference, the controller is configured to: obtain the peak current corresponding to the three-phase current; determine the target current corresponding to the three-phase current based on the peak current and the angle difference.

[0014] The above technical solution has the following beneficial effects: By determining the peak current corresponding to the three-phase current, the target current corresponding to the three-phase current can be accurately obtained, and then the angular frequency of the three-phase current can be accurately determined.

[0015] In some embodiments, when determining the angular frequency of the three-phase current based on the target current, the controller is configured to: perform PI adjustment on the target current to determine the angular frequency of the three-phase current.

[0016] The above technical solution has the following beneficial effects: By performing PI regulation on the target current, the angular frequency of the three-phase current can be accurately output.

[0017] In some embodiments, when performing PI regulation on the target current to determine the angular frequency of the three-phase current, the controller is configured to: obtain the proportional coefficient and the integral coefficient of the PI regulation; perform the PI regulation based on the proportional coefficient and the integral coefficient to determine the angular frequency of the three-phase current.

[0018] The above technical solution has the following beneficial effects: By determining the proportional coefficient and the integral coefficient of the PI regulation, the angular frequency can converge stably during the PI regulation, so as to accurately obtain the angular frequency of the three-phase current.

[0019] In some embodiments, when obtaining the proportional coefficient and the integral coefficient of the PI regulation, the controller is configured to: obtain a preset damping coefficient and a preset current frequency; determine the proportional coefficient and the integral coefficient based on the preset damping coefficient and the preset current frequency.

[0020] The above technical solution has the following beneficial effects: By obtaining the preset damping coefficient and the preset current frequency, the optimal proportional coefficient and integral coefficient can be accurately obtained, making the angular frequency output by the PI regulation closer to the true value, and thus the angular frequency of the three-phase current with high precision can be obtained.

[0021] In some embodiments, when determining whether the phase sequence of the compressor is correct based on the angular frequency, the controller is further configured to: when the angular frequency is positive, determine that the phase sequence of the compressor is correct; when the angular frequency is negative, determine that the phase sequence of the compressor is incorrect.

[0022] The above technical solution has the following beneficial effects: By judging whether the phase sequence of the compressor is correct through the positive and negative of the angular frequency, voltage sampling can be avoided. At the same time, by directly determining the positive and negative of the angular frequency to judge the phase sequence, complex calculations are not required, and there is no low-speed failure problem, and the accuracy of phase sequence judgment is relatively high.

[0023] In some embodiments, the current detection device includes at least two current transformers, and the at least two current transformers are respectively connected to at least two phases of the three-phase wires of the compressor.

[0024] The above technical solution has the following beneficial effects: By setting at least two current transformers, the hardware design can be simplified, and at the same time, the accuracy of the angular frequency of the three-phase current is ensured.

[0025] In some embodiments, the air conditioner further includes a display module connected to the controller, configured to receive a signal sent by the controller indicating whether the phase sequence of the compressor is correct or incorrect, and display the judgment result of the phase sequence of the compressor based on the signal.

[0026] The above technical solution has the following beneficial effects: By conveying the state of the compressor phase sequence to the user in an intuitive manner, the reliability of phase sequence detection and the user experience can be improved.

[0027] To achieve the above object, an embodiment of the second aspect of the present invention provides a control method for an air conditioner, the method including the following steps: acquiring the three-phase current; determining the angular frequency of the three-phase current; and judging whether the phase sequence of the compressor is correct based on the angular frequency.

[0028] According to the control method of the air conditioner in the embodiment of the present invention, in the full speed range of the compressor, by collecting the three-phase current signal of the compressor, the angular frequency of the three-phase current of the compressor can be determined, so that it is possible to judge whether the phase sequence of the compressor is correct according to the positive or negative of the angular frequency, without voltage sampling. At the same time, directly determining the phase sequence by determining the angular frequency symbol does not require complex calculations and there is no low-speed failure problem, and the accuracy of phase sequence judgment is relatively high.

[0029] The additional aspects and advantages of the present invention will be partly given in the following description, partly will become obvious from the following description, or be understood through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The above and / or additional aspects and advantages of the present invention will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, where: Figure 1 is a schematic diagram of a refrigeration cycle system of an air conditioner according to an embodiment of the present invention; Figure 2 is a schematic diagram of the structure of an air conditioner according to an embodiment of the present invention; Figure 3 is a schematic diagram of the structure of a controller according to an embodiment of the present invention; Figure 4 is a schematic diagram of the structure of an air conditioner according to another embodiment of the present invention; Figure 5 is a schematic diagram of the principle of determining the angular frequency of three-phase current according to an embodiment of the present invention; Figure 6 is a schematic diagram of the principle of determining the target current corresponding to three-phase current based on the actual angle and the estimated angle according to an embodiment of the present invention; Figure 7 is a schematic diagram of the simulation result of estimating the angular frequency based on a phase-locked loop according to an embodiment of the present invention; Figure 8 It is a schematic diagram of the simulation result of estimating the angular frequency based on a phase-locked loop according to another embodiment of the present invention; Figure 9 It is a schematic structural diagram of a current detection device according to an embodiment of the present invention; Figure 10 It is a schematic structural diagram of a current detection device according to an embodiment of the present invention; Figure 11 It is a schematic structural diagram of the compressor phase sequence detection according to an embodiment of the present invention; Figure 12 It is a schematic structural diagram of the compressor phase sequence detection according to another embodiment of the present invention; Figure 13 It is a flowchart of a control method for an air conditioner according to an embodiment of the present invention. Detailed implementation manners

[0031] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0032] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is 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 thus should not be construed as a limitation to the present invention.

[0033] The terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise stated, the meaning of "plurality" is two or more.

[0034] In the description of the present invention, it should be noted that, unless otherwise clearly specified and defined, the terms "installed", "connected", and "coupled" 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 mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] As Figure 1 shown, in the present invention, the air conditioner 1 performs a refrigeration cycle by using a compressor, a condenser, an evaporator, a throttling component, and a four-way valve. The refrigeration cycle includes a series of processes involving compression, condensation, and evaporation, and supplies refrigerant to the air that has been conditioned and heat-exchanged.

[0036] The compressor compresses the refrigerant gas in a high-temperature and high-pressure state that enters from the suction pipe and discharges the compressed refrigerant gas through the discharge pipe. The discharged refrigerant gas flows into the condenser from the condenser inlet pipe. The condenser condenses the compressed refrigerant into a liquid phase, and heat is released to the surrounding environment through the condensation process.

[0037] The evaporator evaporates the refrigerant that expands in the throttling device and returns the refrigerant gas in a low-temperature and low-pressure state to the compressor. 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. Throughout the cycle, the air conditioner 1 can adjust the temperature of the indoor space.

[0038] Combined Figure 2 and Figure 4 shown, the air conditioner 1 in the present application includes an indoor fan 12 and an outdoor fan 13. The indoor fan 12 and the outdoor fan 13 can be set as an integrated machine or a split machine. The indoor fan 12 can be set as a wall-mounted type, a ceiling type, a duct type, etc., and the indoor fan 12 is installed on the top or ceiling of the indoor room.

[0039] Taking the indoor wall-mounted unit as an example, the indoor wall-mounted unit is usually installed at positions such as the indoor wall surface. Again, for example, an indoor cabinet unit (not shown in the figure) is also a form of the indoor fan 12.

[0040] Taking the split machine as an example, the air conditioner 1 includes an indoor fan 12 and an outdoor fan 13. Among them, the outdoor fan 13 is usually set outdoors and is used for heat exchange with the indoor environment.

[0041] In addition, the air conditioner 1 is provided with a controller 71 to control the operation of various components inside the air conditioner 1, so that the operation of each component of the air conditioner 1 realizes each predetermined function of the air conditioner 1. Among them, a control device 200 is additionally attached to the air conditioner 1. Exemplarily, the control device 200 is specifically set as a remote controller, and the remote controller has a function of communicating with the controller 71 using, for example, infrared rays or other communication methods. The remote controller is used for the user to perform various controls on the air conditioner 1, realizing the interaction between the user and the air conditioner 1.

[0042] In the embodiment of the present application, the indoor fan 12 of the air conditioner 1 is arranged at the top or upper part of the room. Generally speaking, the installation height of the indoor fan 12 is higher than the user activity area. The indoor fan 12 includes an air return port 17 and an air outlet 16 communicating with the room. The indoor air passes through the air return port 17 into the indoor fan 12 and flows back into the room through the air outlet 16.

[0043] At the position of the air outlet 16, a wind deflector 2 is provided. The wind deflector 2 adjusts the outflow direction of the air flowing through the air outlet 12 by changing its relative rotation angle with the air outlet 16, thereby affecting the air temperature stratification in the room.

[0044] The embodiment of the present application also provides a schematic diagram of the hardware structure of the controller 71, as Figure 3 shown. The controller 71 includes a processor 83. Optionally, it 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 through a bus 81.

[0045] The processor 83 may be a central processing unit (CPU), a general-purpose processor, a network processor (NP), a digital signal processor (DSP), a microprocessor, a microcontroller, a programmable logic device (PLD), or any combination thereof. The processor 83 may also be any other device with processing functions, 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 or a multi-CPU processor. Here, the processor 83 may refer to one or more devices, circuits, or processing cores for processing data (such as computer program instructions).

[0046] The memory 82 can be a read-only memory (ROM), or other types of static storage devices that can store static information and instructions, a random access memory (RAM), or other types of dynamic storage devices that can store information and instructions. It can also be an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM), or other optical disc storage, optical disc storage (including compact discs, laser discs, optical discs, digital versatile discs, Blu-ray discs, etc.), magnetic disk storage media, or other magnetic storage devices, or any other medium that can be used to carry or store the desired program code in the form of instructions or data structures and can be accessed by a computer. The embodiments of the present application do not impose any restrictions on this. The memory 82 can exist independently or be integrated with the processor 83. Among them, the memory 82 can contain computer program code. The processor 83 is used to execute the computer program code stored in the memory 82, thereby implementing the control method of the air conditioner 1 provided by the embodiments of the present application.

[0047] 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 capable of implementing communication.

[0048] 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.

[0049] The following combines Figures 4 - 13 to describe the air conditioner 1 and its control method according to the embodiments of the present invention.

[0050] In some embodiments, as Figure 4 shown, the air conditioner 1 includes: a refrigerant circulation circuit 10. The refrigerant circulation circuit enables the refrigerant to perform a refrigeration cycle in a circuit composed of a compressor, a condenser, a throttling device, and an evaporator. One of the condenser and the evaporator is an outdoor heat exchanger, and the other is an indoor heat exchanger.

[0051] In some embodiments, as Figure 4 shown, the air conditioner 1 may include: a current detection device 11 for collecting the three-phase current passing through the compressor.

[0052] In some embodiments, as Figure 4 shown, the air conditioner 1 may include: a controller 71 configured to: obtain the three-phase current; determine the angular frequency of the three-phase current; judge whether the phase sequence of the compressor is correct based on the angular frequency.

[0053] Specifically, in the existing air conditioner 1, the compressor is usually powered by three-phase alternating current. Therefore, in the process of judging whether the phase sequence of the compressor is correct, the three-phase current can be obtained through the current detection device 11, where the current detection device 11 includes but is not limited to a Hall effect sensor or a current transformer.

[0054] Further, after obtaining the three-phase current, the angular frequency corresponding to the three-phase current can be determined, that is, the phase angle radian value of the change of the three-phase current per unit time. Specifically, based on the phase-locked loop principle, in the process of performing coordinate transformation and closed-loop control on the three-phase current to achieve high-precision tracking of the current phase, the angular frequency of the three-phase current can be determined.

[0055] Further, since the variable-frequency compressor is a permanent magnet synchronous motor, and for a synchronous motor, the angular frequency of the compressor operation is equal to the angular frequency of the three-phase current. At the same time, since the general minimum operating mechanical frequency of the compressor is greater than 10 Hz and the minimum number of pole pairs (P) of the compressor is 2 pairs of poles, therefore, according to the following formula: , where is the angular frequency of the three-phase current, is the mechanical angular velocity of the compressor, is the number of pole pairs of the compressor, is the mechanical frequency of the compressor, it can be known that the angular frequency of the three-phase current is greater than 63 rad / s, that is, 2π×10×2≈63. Therefore, after determining the angular frequency of the three-phase current, it can be judged whether the phase sequence of the compressor is correct based on the angular frequency.

[0056] According to the air conditioner 1 of the embodiment of the present invention, in the full speed range of the compressor, by collecting the three-phase current signal of the compressor, the angular frequency of the three-phase current of the compressor can be determined, so that it can be judged whether the phase sequence of the compressor is correct according to the positive and negative of the angular frequency, without voltage sampling. At the same time, directly determining the phase sequence by determining the angular frequency symbol does not require complex calculations and there is no low-speed failure problem, and the accuracy of phase sequence judgment is relatively high. In an embodiment of the present invention, when determining the angular frequency of the three-phase current, the controller 71 is configured to: perform a stationary coordinate system transformation and a rotating coordinate system transformation on the three-phase current to determine the actual angle of the three-phase current in the stationary coordinate system and the estimated angle of the three-phase current in the rotating coordinate system; Determine the target current corresponding to the three-phase current based on the actual angle and the estimated angle; Determine the angular frequency of the three-phase current based on the target current.

[0057] Specifically, as shown in Figure 5 , when determining the angular frequency of the three-phase current, based on the phase-locked loop principle, the acquired three-phase current (IU, IV, IW) can be subjected to a stationary coordinate system transformation (Clarke transformation) and a rotating coordinate system transformation (Park transformation) to determine the actual angle of the three-phase current in the stationary coordinate system and the estimated angle of the three-phase current in the rotating coordinate system . Among them, the stationary coordinate system transformation adopts an equal-amplitude transformation, which can transform the three-phase current (IU, IV, IW) from the three-phase stationary coordinate system (d-q axis coordinate system) to the two-phase stationary coordinate system ( - axis coordinate system) to determine the actual angle of the three-phase current in the stationary coordinate system , that is, the angle between the d-axis and the α-axis. The transformation formula is as follows: ; at the same time, the two-phase stationary coordinate system current can be further transformed into the rotating coordinate system ( - axis coordinate system) to determine the estimated angle of the three-phase current in the rotating coordinate system, that is, axis and axis, and its transformation formula is as follows: , where is the estimated angle.

[0058] Furthermore, since the essence of the phase-locked loop principle is to correct the angle difference between the actual angle and the estimated angle to achieve phase tracking, therefore, the component related to the angle difference between the actual angle and the estimated angle can be extracted, that is, axis current, as the target current corresponding to the three-phase current.

[0059] Furthermore, the angular frequency of the three-phase current can be determined based on the target current, including but not limited to inputting the target current to a PI regulator to determine the angular frequency of the three-phase current.

[0060] In an embodiment of the present invention, when determining the target current corresponding to the three-phase current based on the actual angle and the estimated angle, the controller 71 is configured to: obtain the angle difference between the actual angle and the estimated angle; Determine the target current corresponding to the three-phase current based on the angle difference.

[0061] Specifically, when determining the target current corresponding to the three-phase current based on the actual angle and the estimated angle, the angle difference between the actual angle and the estimated angle can be obtained. At the same time, since the component related to the angle difference is the shaft current, therefore, the target current corresponding to the three-phase current can be determined based on the angle difference, that is the shaft current.

[0062] In an embodiment of the present invention, when determining the target current corresponding to the three-phase current based on the angle difference, the controller is configured to: obtain the peak current corresponding to the three-phase current; Determine the target current corresponding to the three-phase current based on the peak current and the angle difference.

[0063] Specifically, since the peak currents of the three-phase currents are the same and are fixed values, that is, the peak values of the three-phase currents never change and are fixed values, which will not affect the subsequent correction of the angle difference. Therefore, combining Figure 6 it can be obtained that , that is , where , is the target current, is the peak current of the three-phase current, is the angle difference.

[0064] In an embodiment of the present invention, as shown in combination with Figure 5 , when determining the angular frequency of the three-phase current based on the target current, the controller 71 is configured to: perform PI regulation on the target current to determine the angular frequency of the three-phase current.

[0065] Specifically, since the PI regulator can perform proportional (P) and integral (I) operations on the error signal to make the angle difference approach zero, realize the angle estimation of the current signal by the phase-locked loop, and perform angle iteration, thereby realizing the phase tracking function of the current signal, that is, the phase-locked function. In this process, since the relationship between the angular frequency and the estimated angle is: , that is , therefore, the output of the PI regulation must be the angular frequency and the estimated angle, that is, performing PI regulation on the target current can determine the angular frequency of the three-phase current.

[0066] In an embodiment of the present invention, when performing PI regulation on the target current to determine the angular frequency of the three-phase current, the controller is configured to: obtain the proportional coefficient and the integral coefficient of the PI regulation; Perform PI regulation based on the proportional coefficient and the integral coefficient to determine the angular frequency of the three-phase current.

[0067] Specifically, in the process of performing PI regulation on the target current to ensure the angular frequency of the three-phase current, the proportional coefficient and the integral coefficient of the PI regulation can be obtained. Among them, the proportional coefficient affects the system bandwidth and the dynamic response speed, while the integral coefficient determines the error elimination speed.

[0068] Furthermore, by performing PI regulation through the proportional coefficient and the integral coefficient, the target value can be tracked quickly and stably, that is, an accurate and stable angular frequency can be obtained based on the target current (such as the q-axis current Iδ in the rotating coordinate system).

[0069] In an embodiment of the present invention, when obtaining the proportional coefficient and the integral coefficient of the PI regulation, the controller is configured to: obtain a preset damping coefficient and a preset current frequency; Determine the proportional coefficient and the integral coefficient based on the preset damping coefficient and the preset current frequency.

[0070] Specifically, in the phase-locked loop technology, the parameters of the PI regulation (the proportional coefficient and the integral coefficient) are crucial for the dynamic performance and the static performance of the system. Among them, if the proportional coefficient is too large, overshoot may occur, and if it is too small, the response will be slow. And if the integral coefficient is too large, integral saturation may occur. Therefore, a preset damping coefficient and a preset current frequency can be obtained. Among them, the preset damping coefficient can be preset according to the specific operating characteristics of the compressor, including but not limited to 0.7, and the preset current frequency can be the mechanical frequency of the three-phase current, including but not limited to 40Hz.

[0071] Furthermore, the proportional coefficient and the integral coefficient can be determined based on the preset damping coefficient and the preset current frequency. Among them, the specific formula for the proportional coefficient is: , where represents the proportional coefficient, represents the preset damping coefficient, is the preset current frequency, is a constant fixed value, including but not limited to the peak value of the three-phase current; the specific formula for the integral coefficient is: , where represents the proportional coefficient, is the preset current frequency, is a constant fixed value, including but not limited to the peak value of the three-phase current.

[0072] In a specific embodiment, the proportional coefficient includes but is not limited to 666, and the integral coefficient includes but is not limited to 16666.

[0073] In an embodiment of the present invention, when determining whether the phase sequence of the compressor is correct based on the angular frequency, the controller 71 is further configured to: when the angular frequency is positive, determine that the phase sequence of the compressor is correct; when the angular frequency is negative, determine that the phase sequence of the compressor is incorrect.

[0074] Specifically, since the variable-frequency compressor is a permanent magnet synchronous motor, and for a synchronous motor, the angular frequency of the compressor operation is equal to the angular frequency of the three-phase current. At the same time, since the general minimum operating mechanical frequency of the compressor is greater than 10 Hz, the minimum number of pole pairs (P) of the compressor is 2 pairs of poles. Therefore, the angular frequency of the three-phase current is greater than 63 rad / s. Thus, when the angular frequency is positive, it can be determined that the phase sequence of the compressor is correct, and when the angular frequency is negative, it can be determined that the phase sequence of the compressor is incorrect.

[0075] In a specific embodiment, in combination with Figure 7 and Figure 8 As shown, based on the simulation results of estimating the angular frequency by the phase-locked loop, if the simulation conditions are: the peak values of IU, IV, and IW are 1.5 A, the current frequency is 40 Hz, and the parameter configuration of the PI regulator is = 666, the integral coefficient = 16666, then the simulation results are as follows: when the current sampling is the positive sequence IU, IV, IW, in the phase-locked loop simulation waveform, the U-phase current input by the phase-locked loop leads the V-phase current by 120 degrees, the V-phase current leads the W-phase current by 120 degrees, and the U, V, and W three-phase currents are in the positive sequence. The angular frequency output by the phase-locked loop starts to converge stably after 0.02 s, and the angular frequency of the three-phase current is 251.3 rad / s, which is a positive number. The theoretical value of the angular frequency of the three-phase current is 2×π×40 = 251.327408≈251.3 rad / s. It can be seen that the simulation conforms to the theoretical design.

[0076] Furthermore, when the current sampling is the reverse sequence IU, IW, IV, in the phase-locked loop simulation waveform, the U-phase current input by the phase-locked loop leads the W-phase current by 120 degrees, the W-phase current leads the V-phase current by 120 degrees, and the U, V, and W three-phase currents are in the reverse sequence. The angular frequency output by the phase-locked loop starts to converge stably after 0.02 s, and the angular frequency of the three-phase current is -251.3, which is a negative number. The theoretical value of the angular frequency of the three-phase current is -2×π×40 = -251.327408≈-251.3 rad / s. It can be seen that the simulation conforms to the theoretical design.

[0077] In summary, based on the simulation results of estimating the angular frequency by the phase-locked loop, it can be known that when the phase sequence is correct, the angular frequency of the three-phase current converges to a positive number, and when the phase sequence is incorrect, the angular frequency of the three-phase current converges to a negative number.

[0078] In an embodiment of the present invention, the current detection device 11 includes at least two current transformers, and the at least two current transformers are respectively connected to at least two phases of the three-phase wires of the compressor in one-to-one correspondence.

[0079] Specifically, as Figure 9As shown, the current detection device 11 can be provided with three current transformers, namely CT1, CT2, and CT3, which are respectively connected to the three phases of the three-phase wires of the compressor. After passing through the differential amplifier circuit, the three-phase currents can be collected simultaneously. Further, since the windings of the compressor are star-connected, the sum of the three-phase currents is 0, that is, IU + IV + IW = 0. Therefore, when collecting the three-phase currents, any two-phase currents can also be sampled, and the third-phase current can be calculated from the sampled two-phase currents. It can be understood that by setting the current transformers to collect the three-phase currents, the anti-interference ability during the three-phase current collection can be improved, the accuracy of the three-phase current collection can be improved, and further the accuracy of the angular frequency of the three-phase currents can be improved.

[0080] In an embodiment of the present invention, the air conditioner 1 further includes: a display module, connected to the controller 71, for receiving a signal sent by the controller 71 indicating whether the phase sequence of the compressor is correct or incorrect, and displaying the phase sequence judgment result of the compressor based on the signal.

[0081] Specifically, as Figure 10 shown, the air conditioner 1 is also provided with a display module connected to the current-limiting resistor and the controller 71. Among them, the display module includes, but is not limited to, one or more LED lights, which are used to intuitively display the phase sequence state of the compressor, can receive a signal sent by the controller 71 indicating whether the phase sequence of the compressor is correct or incorrect, and display the phase sequence judgment result based on the signal. For example, when the phase sequence is correct, the controller 71 can send a high-level signal (such as 5V), and when the display module receives the high-level signal, it can display the state of "correct phase sequence" (such as the LED light is off or the display screen shows "Correct"); when the phase sequence is incorrect, the controller 71 can send a low-level signal (such as 0V), and when the display module receives the low-level signal, it displays the state of "incorrect phase sequence" (such as the LED light is on or the display screen shows "Error").

[0082] To sum up, in a specific embodiment, as shown in combination with Figure 11 and Figure 12 during the process of detecting the phase sequence of the compressor, the current detection device 11 can detect the three-phase currents (IU, IV, IW) between the frequency converter and the compressor through three current transformers or two current transformers, and send them to the controller. The controller can calculate the angular frequency of the three-phase currents based on the phase-locked loop principle, judge whether it is correct according to the positive and negative of the angular frequency, and output the detection result to the display module for display.

[0083] According to the air conditioner 1 of the embodiment of the present invention, within the full speed range of the compressor, by collecting the three-phase current signals of the compressor, the angular frequency of the three-phase current of the compressor can be determined. Thus, it is possible to judge whether the phase sequence of the compressor is correct according to the positive or negative of the angular frequency, without the need for voltage sampling. At the same time, by directly determining the sign of the angular frequency to judge the phase sequence, there is no need for complex calculations, and there is no low-speed failure problem, and the accuracy of phase sequence judgment is relatively high.

[0084] As Figure 13 shown, the control method of the air conditioner according to the embodiment of the present invention at least includes step S1-step S3.

[0085] Step S1, obtaining three-phase current.

[0086] Step S2, determining the angular frequency of the three-phase current.

[0087] Step S3, judging whether the phase sequence of the compressor is correct based on the angular frequency.

[0088] In some embodiments, determining the angular frequency of the three-phase current specifically includes: performing a stationary coordinate system transformation and a rotating coordinate system transformation on the three-phase current to determine the actual angle of the three-phase current in the stationary coordinate system and the estimated angle of the three-phase current in the rotating coordinate system; determining the target current corresponding to the three-phase current based on the actual angle and the estimated angle; determining the angular frequency of the three-phase current based on the target current.

[0089] In some embodiments, determining the target current corresponding to the three-phase current based on the actual angle and the estimated angle specifically includes: obtaining the angle difference between the actual angle and the estimated angle; determining the target current corresponding to the three-phase current based on the angle difference.

[0090] In some embodiments, determining the target current corresponding to the three-phase current based on the angle difference specifically includes: obtaining the peak current corresponding to the three-phase current; determining the target current corresponding to the three-phase current based on the peak current and the angle difference.

[0091] In some embodiments, determining the angular frequency of the three-phase current based on the target current specifically includes: performing PI regulation on the target current to determine the angular frequency of the three-phase current.

[0092] In some embodiments, performing PI regulation on the target current to determine the angular frequency of the three-phase current specifically includes: obtaining the proportional coefficient and the integral coefficient of the PI regulation; performing PI regulation based on the proportional coefficient and the integral coefficient to determine the angular frequency of the three-phase current.

[0093] In some embodiments, obtaining the proportional coefficient and the integral coefficient of the PI regulation specifically includes: obtaining the preset damping coefficient and the preset current frequency; determining the proportional coefficient and the integral coefficient based on the preset damping coefficient and the preset current frequency.

[0094] In some embodiments, it is determined whether the phase sequence of the compressor is correct based on the angular frequency, which specifically includes: when the angular frequency is positive, it is determined that the phase sequence of the compressor is correct; when the angular frequency is negative, it is determined that the phase sequence of the compressor is incorrect.

[0095] In some embodiments, the control method of the air conditioner further includes: receiving a signal sent by the controller indicating that the phase sequence of the compressor is correct or incorrect, and displaying the phase sequence determination result of the compressor based on the signal.

[0096] It should be noted that when controlling the air conditioner, the specific implementation manner is similar to that of the air conditioner in any one of the above embodiments of the present invention. Therefore, for a detailed exemplary description of the control process of the air conditioner, reference can be made to the relevant description part of the air conditioner mentioned above. To reduce redundancy, it will not be repeated here.

[0097] According to the control method of the air conditioner in the embodiments of the present invention, within the full speed range of the compressor, by collecting the three-phase current signals of the compressor, the angular frequency of the three-phase current of the compressor can be determined, so that it is possible to determine whether the phase sequence of the compressor is correct according to the positive or negative of the angular frequency, without the need for voltage sampling. At the same time, the phase sequence is directly determined by determining the angular frequency symbol, without complex calculations, and there is no low-speed failure problem, and the accuracy of phase sequence determination is relatively high.

[0098] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example.

[0099] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirits of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims

1. An air conditioner, characterized in that, Comprising: A refrigerant circulation circuit that enables the refrigerant to perform a refrigeration cycle in a circuit composed of a compressor, a condenser, a throttling component, an evaporator, and a four-way valve, where one of the condenser and the evaporator is an outdoor heat exchanger and the other is an indoor heat exchanger; A current detection device for collecting the three-phase current passing through the compressor; A controller connected to the current detection device, and the controller is configured to: Obtain the three-phase current; Determine the angular frequency of the three-phase current; Judge whether the phase sequence of the compressor is correct based on the angular frequency.

2. The air conditioner according to claim 1, characterized in that When determining the angular frequency of the three-phase current, the controller is configured to: Perform a static coordinate system transformation and a rotating coordinate system transformation on the three-phase current to determine the actual angle of the three-phase current in the static coordinate system and the estimated angle of the three-phase current in the rotating coordinate system; Determine the target current corresponding to the three-phase current based on the actual angle and the estimated angle; Determine the angular frequency of the three-phase current based on the target current.

3. The air conditioner according to claim 2, wherein When determining the target current corresponding to the three-phase current based on the actual angle and the estimated angle, the controller is configured to: Obtain the angle difference between the actual angle and the estimated angle; Determine the target current corresponding to the three-phase current based on the angle difference.

4. The air conditioner according to claim 3, wherein, When determining the target current corresponding to the three-phase current based on the angle difference, the controller is configured to: Obtain the peak current corresponding to the three-phase current; Determine the target current corresponding to the three-phase current based on the peak current and the angle difference.

5. The air conditioner according to claim 4, characterized in that, When determining the angular frequency of the three-phase current based on the target current, the controller is configured to: Perform PI regulation on the target current to determine the angular frequency of the three-phase current.

6. The air conditioner according to claim 5, characterized in that, When performing PI regulation on the target current to determine the angular frequency of the three-phase current, the controller is configured to: Obtain the proportional coefficient and the integral coefficient of the PI regulation; Perform the PI regulation based on the proportional coefficient and the integral coefficient to determine the angular frequency of the three-phase current.

7. The air conditioner according to claim 5, characterized in that, When obtaining the proportional coefficient and the integral coefficient of the PI regulation, the controller is configured to: Obtain a preset damping coefficient and a preset current frequency; Determine the proportional coefficient and the integral coefficient based on the preset damping coefficient and the preset current frequency.

8. The air conditioner according to claim 1, characterized in that When judging whether the phase sequence of the compressor is correct based on the angular frequency, the controller is further configured to: When the angular frequency is positive, determine that the phase sequence of the compressor is correct; When the angular frequency is negative, determine that the phase sequence of the compressor is incorrect.

9. The air conditioner according to claim 1, characterized in that, The current detection device includes at least two current transformers, and the at least two current transformers are respectively connected to at least two of the three-phase wires of the compressor.

10. The air conditioner according to claim 1, characterized in that, Further comprising: A display module connected to the controller, for receiving a signal sent by the controller for indicating whether the phase sequence of the compressor is correct or incorrect, and correspondingly displaying the phase sequence judgment result of the compressor based on the signal.

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