Downclocking control method, control circuit, air conditioner and computer readable storage medium

Abstract

The invention provides a frequency reduction control method, a control circuit, an air conditioner and a computer readable storage medium. The frequency reduction control method comprises the following steps that the original fixed frequency of a motor and the input current and the bus voltage of the control circuit are obtained; pID adjustment is carried out according to the input current and the bus voltage, and the proportional quantity, the integral quantity and the differential quantity of the current control period are obtained; determining a frequency decline value according to the proportional quantity, the integral quantity and the differential quantity; and determining a target frequency according to the frequency drop value and the original fixed frequency, and controlling the motor to drop from the original fixed frequency to the target frequency. According to the embodiment of the invention, as the given operation frequency of the motor is adjusted and compensated through proportional-integral-differential control, when the input voltage drops, the input current can be reduced by rapidly limiting the frequency of the motor, and the method has a function of rapid closed-loop frequency reduction after the input voltage drops; input current over-current protection or motor faults can be prevented, and the possibility of damage to the electric control board is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of air conditioners, and in particular to a frequency reduction control method, a control circuit, an air conditioner and a computer-readable storage medium. Background Art

[0002] In the related art, when the input grid voltage drops, the input current will inevitably increase due to the basically unchanged load power in a short period of time, and the circuit's overcurrent capacity is limited. When the input current is too large, the input circuit will be damaged, and the air-conditioning system will fail. Secondly, when the input voltage drops, the bus voltage will inevitably decrease significantly. Since the compressor frequency remains almost unchanged in a short period of time, the compressor will stall or overcurrent failure will occur due to the low voltage.

[0003] Currently, there is no special treatment for input voltage drop, and the electric control board is only protected by other fault judgments. However, when a voltage drop occurs, the electric control board is still likely to be damaged or report a fault. Summary of the invention

[0004] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, the present application proposes a frequency reduction control method, a control circuit, an air conditioner and a computer-readable storage medium, which are intended to reduce system failures when an input voltage drops.

[0005] In a first aspect, an embodiment of the present application provides a frequency reduction control method, which is applied to a control circuit, wherein the control circuit is used to control the operation of a motor, and the frequency reduction control method includes:

[0006] Obtaining the original frequency of the motor and the input current and bus voltage of the control circuit;

[0007] Perform PID adjustment according to the input current and the bus voltage to obtain a proportional quantity, an integral quantity and a differential quantity of a current control cycle;

[0008] Determine a frequency drop value according to the proportional amount, the integral amount and the derivative amount;

[0009] The target frequency is determined according to the frequency reduction value and the original frequency, and the motor is controlled to reduce the frequency from the original frequency to the target frequency.

[0010] According to some embodiments of the present application, performing PID regulation according to the input current and the bus voltage to obtain a proportional amount, an integral amount, and a differential amount of a current control cycle includes:

[0011] Perform proportional adjustment according to the input current and the preset current frequency limit threshold to obtain a proportional amount of the current control cycle;

[0012] Performing integral adjustment according to the input current and the preset current frequency limiting threshold to obtain an integral amount of the current control cycle;

[0013] A differential adjustment is performed according to the bus voltage to obtain a differential amount of the current control cycle.

[0014] According to some embodiments of the present application, performing proportional adjustment according to the input current and the preset current frequency limit threshold to obtain the proportional amount of the current control cycle includes:

[0015] Get the proportional adjustment coefficient;

[0016] Subtracting the preset current frequency limiting threshold from the input current to obtain a current error value;

[0017] The proportional amount of the current control cycle is obtained according to the current error value and the proportional adjustment coefficient.

[0018] According to some embodiments of the present application, after obtaining the current error value, the frequency reduction control method further includes:

[0019] Get the first clipping interval;

[0020] When the current error value is within the first limiting interval, retaining the current error value;

[0021] When the current error value is outside the first amplitude limiting interval, the current error value is discarded.

[0022] According to some embodiments of the present application, performing integral adjustment according to the input current and the preset current frequency limit threshold to obtain the integral amount of the current control cycle includes:

[0023] Obtain the integral adjustment coefficient and the historical integral amount of the historical control cycle;

[0024] Subtracting the preset current frequency limiting threshold from the input current to obtain a current error value;

[0025] The integral amount of the current control cycle is obtained according to the current error value, the integral adjustment coefficient and the historical integral amount.

[0026] According to some embodiments of the present application, obtaining the integral amount of the current control cycle according to the current error value, the integral adjustment coefficient and the historical integral amount includes:

[0027] Calculating the product of the current error value and the integral adjustment coefficient to obtain an initial integral amount;

[0028] The sum of the initial integral amount and the historical integral amount is calculated to obtain the integral amount of the current control cycle.

[0029] According to some embodiments of the present application, after obtaining the integral amount of the current control cycle, the frequency reduction control method further includes:

[0030] Obtain the second clipping interval;

[0031] When the integral amount of the current control cycle is within the second clipping interval, retaining the integral amount;

[0032] When the integral amount of the current control cycle is outside the second clipping interval, the integral amount is discarded.

[0033] According to some embodiments of the present application, performing differential adjustment according to the bus voltage to obtain a differential amount of the current control cycle includes:

[0034] Get the differential adjustment coefficient;

[0035] Performing low-pass filtering on the bus voltage to obtain a historical bus voltage of a historical control period;

[0036] Subtracting the bus voltage from the historical bus voltage to obtain a voltage error value;

[0037] The differential amount of the current control cycle is obtained according to the voltage error value and the differential adjustment coefficient.

[0038] According to some embodiments of the present application, after obtaining the voltage error value, the frequency reduction control method further includes:

[0039] Get the third clipping interval;

[0040] When the voltage error value is within the third clipping interval, retaining the voltage error value;

[0041] When the voltage error value is outside the third clipping interval, the voltage error value is discarded.

[0042] According to some embodiments of the present application, after determining the frequency reduction value according to the proportional amount, the integral amount and the differential amount, the frequency reduction control method further includes:

[0043] Get the fourth clipping interval;

[0044] When the frequency decrease value is within the fourth limiting interval, retaining the frequency decrease value;

[0045] When the frequency drop value is outside the fourth clipping interval, the frequency drop value is discarded.

[0046] In a second aspect, an embodiment of the present application provides a control circuit, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the frequency reduction control method as described in the first aspect above when running the computer program.

[0047] In a third aspect, an embodiment of the present application provides an air conditioner, comprising the control circuit of the second aspect described above.

[0048] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium storing computer-executable instructions, wherein the computer-executable instructions are used to execute the frequency reduction control method as described in the first aspect above.

[0049] According to the technical solution of the embodiment of the present application, it includes but is not limited to the following technical effects: first, the embodiment of the present application will obtain the original frequency of the motor and the input current and bus voltage of the control circuit; then, the embodiment of the present application will perform PID adjustment according to the input current and bus voltage to obtain the proportional amount, integral amount and differential amount of the current control cycle; then, the embodiment of the present application will determine the frequency drop value according to the proportional amount, integral amount and differential amount; finally, the embodiment of the present application will determine the target frequency according to the frequency drop value and the original frequency, and control the motor to drop from the original frequency to the target frequency. Since the embodiment of the present application adjusts and compensates the given motor operating frequency through proportional-integral-differential control, when the input voltage drops, the input current can be reduced by quickly limiting the frequency of the motor, and it has the function of fast closed-loop frequency reduction after the input voltage drops, which can prevent the input current overcurrent protection or motor failure and reduce the possibility of damage to the electric control board.

[0050] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] The accompanying drawings are used to provide further understanding of the technical solution of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present application and do not constitute a limitation on the technical solution of the present application.

[0052] Figure 1 is a schematic diagram of the structure of a control circuit provided by an embodiment of the present application;

[0053] Figure 2 This is a schematic diagram of a fast closed-loop frequency reduction function after input voltage drops provided by an embodiment of the present application;

[0054] Figure 3 is a flow chart of a frequency reduction control method provided by an embodiment of the present application;

[0055] Figure 4 is a flow chart of a frequency reduction control method provided by another embodiment of the present application;

[0056] Figure 5 is a flow chart of a frequency reduction control method provided by another embodiment of the present application;

[0057] Figure 6 is a flow chart of a frequency reduction control method provided by another embodiment of the present application;

[0058] Figure 7 is a flow chart of a frequency reduction control method provided by another embodiment of the present application;

[0059] Figure 8 is a flow chart of a frequency reduction control method provided by another embodiment of the present application;

[0060] Fig. 9 is a flow chart of a frequency reduction control method provided by another embodiment of the present application;

[0061] Fig.10 is a flow chart of a frequency reduction control method provided by another embodiment of the present application;

[0062] Fig.11 is a flow chart of a frequency reduction control method provided by another embodiment of the present application;

[0063] Fig.12 is a flow chart of a frequency reduction control method provided by another embodiment of the present application;

[0064] Fig.13 This is the existing AC input voltage drop test diagram;

[0065] Fig.14 This is an AC input voltage drop test diagram of an embodiment of the present application;

[0066] Fig.15 is a current waveform diagram when the frequency is reduced to the lowest point during the AC input voltage drop test of the embodiment of the present application;

[0067] Fig.16 It is a structural diagram of a controller for executing a frequency reduction control method provided in one embodiment of the present application. DETAILED DESCRIPTION

[0068] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0069] In the description of the present application, it should be understood that descriptions involving orientation, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0070] In the description of this application, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed", etc. are understood to exclude the number itself, and "above", "below", "within", etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0071] In the description of this application, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in this application based on the specific content of the technical solution.

[0072] In some cases, when the input grid voltage drops, the input current will inevitably increase in a short period of time because the load power remains basically unchanged, and the circuit's overcurrent capacity is limited. When the input current is too large, the input circuit will be damaged, and the air-conditioning system will fail. Secondly, when the input voltage drops, the bus voltage will inevitably decrease significantly. Since the compressor frequency remains almost unchanged in a short period of time, the compressor will stall or overcurrent failure will occur due to the voltage being too low.

[0073] The existing air conditioner control scheme has no special processing for input voltage drop, but protects the electronic control board by judging the following faults: 1. The whole machine current exceeds the overcurrent protection threshold, and the whole machine overcurrent protection is reported; 2. The compressor current exceeds the compressor overcurrent protection threshold, and the compressor overcurrent protection is reported; 3. The compressor speed error exceeds the stall judgment threshold, and the compressor stall protection is reported.

[0074] Therefore, there is currently no special treatment for input voltage drops, and the electric control board is only protected by other fault judgments. However, when a voltage drop occurs, the electric control board is still likely to be damaged or report a fault.

[0075] Based on the above situation, the embodiments of the present application propose a frequency reduction control method, a control circuit, an air conditioner and a computer-readable storage medium, which are intended to reduce system failures when the input voltage drops.

[0076] The various embodiments of the control circuit of the present application are further described below in conjunction with the accompanying drawings.

[0077] like Figure 1As shown, Figure 1 It is a structural diagram of a control circuit provided by an embodiment of the present application.

[0078] The control circuit of the embodiment of the present application includes but is not limited to a rectifier module 100, a charge and discharge module 200 and a power factor adjustment module IPM, wherein the input side of the rectifier module 100 is used to connect to an alternating current power source AC, and the output side is connected to the input side of the charge and discharge module 200, and the output side of the charge and discharge module 200 is connected to a load M via the power factor adjustment module IPM.

[0079] In one embodiment, the rectifier module 100 in the embodiment of the present application can receive alternating current from an alternating current power source AC, convert the alternating current into direct current, and then supply the direct current to the charging and discharging module 200. The charging and discharging module 200 will obtain direct current with a certain voltage value after the charging and discharging operation, and supply the direct current to the power factor adjustment module IPM. Then the power factor adjustment module IPM will convert the direct current into alternating current, and supply the alternating current to the load M.

[0080] It can be understood that the above-mentioned load M can be a fan, specifically a motor in the fan; it can also be a compressor, specifically a motor in the compressor; it can also be other equipment; the embodiment of the present application does not specifically limit the type of the above-mentioned load M.

[0081] For example, Figure 1 As shown, the rectifier module 100 can be a bridge stack composed of four diodes D1, D2, D3 and D4, which can convert the AC input voltage of the AC power supply AC into a DC voltage and supply the DC voltage to the charge and discharge module 200; in addition, the charge and discharge module 200 includes but is not limited to an inductor L, a switching device Q, a diode D5, a capacitor C and a control unit, wherein one end of the inductor L is connected to the rectifier module 100, the other end is connected to the input end of the switching device Q and is also connected to the capacitor C through the diode D5, and the output end of the control unit is connected to the control end of the switching device Q; wherein the voltage across the capacitor C is the bus voltage, which is used to provide energy for the operation of the load M; in addition, when the switching device Q is turned on, the inductor L stores energy, and when the switching device Q is turned off, the inductor L charges the capacitor C.

[0082] In addition, the embodiments of the present application may also include but are not limited to a current detection unit, which is connected to the output side of the rectifier module 100. For example, the current detection unit may correspond to Figure 1 The resistance R in.

[0083] like Figure 1As shown in FIG. 1 , when the input AC voltage drops instantly, the bus voltage across the capacitor C will inevitably decrease significantly, and the current will increase significantly, which is insufficient to satisfy the load M to maintain the current frequency operation. In this regard, the embodiment of the present application proposes a control method for fast closed-loop frequency reduction after the input voltage drops, such as Figure 2 As shown, Figure 2 This is a schematic diagram of a fast closed-loop frequency reduction function after an input voltage drop provided by an embodiment of the present application.

[0084] Among them, Figure 2 It can be seen that its input parameters include Iin_thr, Iin_rms and Vn; its output parameters include Fn. Among them, Iin_thr is used to characterize the current frequency limit threshold, Iin_rms is used to characterize the input current effective value, Vn is used to characterize the actual bus voltage of the current control cycle, and Fn is used to characterize the final target frequency.

[0085] Therefore, by Figure 2 It can be seen that the embodiment of the present application can adjust the load operating frequency according to the input current and the frequency-limiting current by proportional-integral, and at the same time compensate the load operating frequency according to the differential change of the bus voltage, so as to achieve the effect of fast frequency reduction and protection of the input circuit. The specific control process in the control process can be seen Figures 3 to 12 The method steps in .

[0086] Based on the hardware structure of the control circuit of each of the above embodiments, various embodiments of the frequency reduction control method of the present application are respectively proposed below.

[0087] like Figure 3 As shown, Figure 3 is a flow chart of a frequency reduction control method provided by an embodiment of the present application. The frequency reduction control method can be applied to the above Figure 1 The control circuit shown may also be applied to control circuits of other structural forms, which may include but are not limited to step S310, step S320, step S330 and step S340.

[0088] Step S310, obtaining the original frequency of the motor and the input current and bus voltage of the control circuit;

[0089] Step S320, adjusting according to the input current and bus voltage to obtain the proportional amount, integral amount and differential amount of the current control cycle;

[0090] Step S330, determining the frequency drop value according to the proportional amount, the integral amount and the differential amount;

[0091] Step S340: determine the target frequency according to the frequency reduction value and the original frequency, and control the motor to reduce the original frequency to the target frequency.

[0092] In one embodiment, in combination Figure 2 As shown, first, the embodiment of the present application needs to obtain the bus voltage and input current of the control circuit, and then perform PID (Proportion-Integral-Differential) adjustment according to the bus voltage and the input current, so as to obtain the proportional amount corresponding to the proportional adjustment, the integral amount corresponding to the integral adjustment, and the differential amount corresponding to the differential adjustment; then, the embodiment of the present application combines and adds the proportional amount, integral amount and differential amount obtained above to obtain the required frequency reduction value; finally, the embodiment of the present application will obtain the original frequency of the load, that is, the original target frequency, and then calculate the new target frequency based on the original frequency and the frequency reduction value, and control the motor to quickly drop from the original frequency to the target frequency.

[0093] Since the embodiment of the present application uses proportional-integral-differential control to adjust and compensate for the given motor operating frequency, when the input voltage drops, the input current can be reduced by quickly limiting the frequency of the motor. It has the function of fast closed-loop frequency reduction after the input voltage drops, which can prevent input current overcurrent protection or motor failure and reduce the possibility of damage to the electronic control board.

[0094] It should be noted that closed-loop control is a control method that performs corrections based on the output feedback of the controlled object. It corrects according to the quota or standard when the actual deviation from the plan is measured. For example, to control the speed of a motor, there must be a sensor that measures the speed and feeds the result back to the control route. Among them, PID is a closed-loop control algorithm, which represents three control algorithms. The combination of these three algorithms can effectively correct the deviation of the controlled object, so that it can reach a stable state.

[0095] In addition, it should be noted that the characteristics of proportional regulation are simple and fast. The disadvantage is that there is a static error for the control object with self-balancing properties; for the system with hysteresis, oscillation may occur and the dynamic characteristics are also poor. Increasing the proportional coefficient can speed up the response speed, reduce the steady-state error of the system, and improve the control accuracy. However, if it is too large, it will produce a large overshoot and even lead to instability; if it is too small, it can reduce the overshoot of the system and increase the stability margin, but it will reduce the regulation accuracy of the system and prolong the transition process time. According to the requirements of the transition process at different stages of the system control process and the experience of the operator, it is usually taken in the initial stage of control to speed up the response speed of the system and reduce the rise time; in the middle of the control process, it is appropriately reduced to reduce the system overshoot; and in the later stage of the transition process, in order to ensure the rapid response performance and steady-state accuracy of the system, it should be appropriately increased.

[0096] In addition, it should be noted that integral regulation can eliminate the static error of the system and is suitable for self-balancing systems. Increasing the integral coefficient is conducive to reducing the static error of the system, but too strong an integral effect will increase the overshoot and even cause oscillation; although reducing the integral coefficient is conducive to system stability, avoiding oscillation and reducing overshoot, it is not conducive to eliminating the static error of the system. Usually in the initial stage of the regulation process, in order to prevent the integral saturation phenomenon caused by certain factors such as saturation nonlinearity, thereby causing a large overshoot in the response process, the integral effect should be weaker and smaller; in the middle of the response process, in order to avoid affecting dynamic stability, the integral effect should be moderate; in the later stage of the process, a larger value should be taken to reduce the static error of the system and improve the regulation accuracy.

[0097] In addition, it should be noted that the differential regulation effect is mainly aimed at improving the dynamic characteristics of the inertia of the controlled object. It can give a deceleration signal for early braking of the response process. It helps to reduce overshoot, overcome oscillation, and make the system stable; at the same time, it speeds up the response speed of the system and reduces the adjustment time, thereby improving the dynamic characteristics of the system. If the differential effect is increased, it will help to speed up the system response, reduce the overshoot, and increase stability, but it will also bring disturbance sensitivity and weaken the ability to suppress interference. If it is too large, the response process will be braked too early, thereby extending the adjustment time; on the contrary, if it is too small, the deceleration of the adjustment process will lag, the overshoot will increase, the system response will slow down, and the stability will deteriorate. Therefore, for time-varying and uncertain systems, a fixed value should not be taken, but should be adapted to the time constant of the controlled object and change immediately. For this type of system, in the early stage of the response process, appropriately increasing the differential action can reduce or even avoid overshoot. In the middle stage of the response process, since the change is very sensitive, it should be smaller and remain unchanged. In the later stage of the adjustment process, it should be even smaller, thereby weakening the braking effect of the process and increasing the ability to suppress disturbances, so that the increase in adjustment time caused by the larger value in the early stage of the adjustment process can be compensated.

[0098] In addition, if Figure 4 As shown, Figure 4 The flowchart of the frequency reduction control method provided by another embodiment of the present application is as follows. Regarding the above step S320 in which PID adjustment is performed according to the input current and the bus voltage to obtain the proportional quantity, integral quantity and differential quantity of the current control cycle, it may include but is not limited to step S410, step S420 and step S430.

[0099] Step S410, performing proportional adjustment according to the input current and the preset current frequency limit threshold to obtain the proportional amount of the current control cycle;

[0100] Step S420, performing integral adjustment according to the input current and the preset current frequency limit threshold to obtain the integral amount of the current control cycle;

[0101] Step S430: Perform differential adjustment according to the bus voltage to obtain the differential amount of the current control cycle.

[0102] In one embodiment, in combination Figure 2 As shown, the PID adjustment method in the embodiment of the present application may include but is not limited to the following three control processes:

[0103] The first control process: Regarding the proportional regulation in the above PID regulation, it refers to performing proportional regulation according to the preset current frequency limit threshold and the actual input current, so as to obtain the proportional amount corresponding to the proportional regulation.

[0104] The second control process: Regarding the integral regulation in the above PID regulation, it refers to performing integral regulation according to a preset current frequency limit threshold and the actual input current, so as to obtain the integral amount corresponding to the integral regulation.

[0105] The third control process: Regarding the differential regulation in the above PID regulation, it refers to performing differential regulation according to the actual bus voltage, so as to obtain the differential amount corresponding to the differential regulation.

[0106] In addition, if Figure 5 As shown, Figure 5 The flowchart of the frequency reduction control method provided by another embodiment of the present application is as follows. Regarding the above step S410, proportional adjustment is performed according to the input current and the preset current frequency limit threshold to obtain the proportional amount of the current control cycle, which may include but is not limited to step S510, step S520 and step S530.

[0107] Step S510, obtaining a proportional adjustment coefficient;

[0108] Step S520, subtract the preset current frequency limit threshold from the input current to obtain a current error value;

[0109] Step S530: Obtain the proportional amount of the current control cycle according to the current error value and the proportional adjustment coefficient.

[0110] In one embodiment, in combination Figure 2 As shown, regarding the above-mentioned proportional regulation process, it is specifically as follows: first, the embodiment of the present application will obtain a preset proportional regulation coefficient; then, the embodiment of the present application will calculate the difference between the preset current frequency limiting threshold and the input current, and use the difference as the current error value; then, the embodiment of the present application will calculate the product value of the current error value and the proportional regulation coefficient, and use the product value as the proportional amount of the current control cycle.

[0111] It can be understood that the above-mentioned proportional adjustment coefficient can be pre-set, and its value can be 2, 3, or other values. The embodiment of the present application does not specifically limit the value of the proportional adjustment coefficient.

[0112] In addition, it can be understood that the above-mentioned current frequency limit threshold can be preset, and the embodiment of the present application does not specifically limit the value of the current frequency limit threshold.

[0113] In addition, if Figure 6 As shown, Figure 6 4 is a flow chart of a frequency reduction control method provided by another embodiment of the present application. After obtaining the current error value in the above step S520, the frequency reduction control method of the embodiment of the present application may also include but is not limited to step S610, step S620 and step S630.

[0114] Step S610, obtaining a first clipping interval;

[0115] Step S620: When the current error value is within the first amplitude limiting interval, retain the current error value;

[0116] Step S630: When the current error value is outside the first limiting interval, the current error value is discarded.

[0117] In one embodiment, in combination Figure 2 As shown, the proportional regulation process after adding the limiting means is as follows: First, the embodiment of the present application will obtain a preset proportional regulation coefficient; then, the embodiment of the present application will calculate the difference between the preset current frequency limiting threshold and the input current, and use the difference as the current error value; then, the embodiment of the present application will limit the current error value, as follows: set a first limiting interval, if the current error value is less than or equal to the upper limit value of the first limiting interval, and greater than or equal to the lower limit value of the first limiting interval, then the current error value is considered to meet the conditions, and the current error value is retained; if the current error value is greater than the upper limit value of the first limiting interval, or less than the lower limit value of the first limiting interval, then the current error value is considered to be unqualified, and the current error value is discarded. Finally, if the current error value is retained, the embodiment of the present application will calculate the product value of the current error value and the proportional regulation coefficient, and use the product value as the proportional amount of the current control cycle.

[0118] It should be noted that the upper limit value of the first limiting interval can be set to 0, so that the expected calculated ratio can be a negative value, thereby ensuring that the final calculated frequency reduction value can be less than or equal to 0, that is, it plays a frequency reduction role instead of frequency increase.

[0119] In addition, it should be noted that the lower limit value of the first clipping interval can be set arbitrarily as needed, and the embodiment of the present application does not specifically limit the lower limit value of the first clipping interval.

[0120] In addition, if Figure 7 As shown, Figure 7 The flowchart of the frequency reduction control method provided by another embodiment of the present application is as follows. Regarding the above step S420, the integral adjustment is performed according to the input current and the preset current frequency limit threshold to obtain the integral amount of the current control cycle, which may include but is not limited to step S710, step S720 and step S730.

[0121] Step S710, obtaining the integral adjustment coefficient and the historical integral amount of the historical control cycle;

[0122] Step S720, subtract the preset current frequency limit threshold from the input current to obtain a current error value;

[0123] Step S730: Obtain the integral amount of the current control cycle according to the current error value, the integral adjustment coefficient and the historical integral amount.

[0124] In addition, if Figure 8 As shown, Figure 8 The flowchart of the frequency reduction control method provided by another embodiment of the present application is as follows. The step S730 of obtaining the integral amount of the current control cycle according to the current error value, the integral adjustment coefficient and the historical integral amount may include but is not limited to step S810 and step S820.

[0125] Step S810, calculating the product of the current error value and the integral adjustment coefficient to obtain an initial integral value;

[0126] Step S820: Calculate the sum of the initial integral amount and the historical integral amount to obtain the integral amount of the current control cycle.

[0127] In one embodiment, in combination Figure 2 As shown, regarding the above-mentioned integral regulation process, it is specifically as follows: first, the embodiment of the present application will obtain a pre-set integral regulation coefficient and the historical integral amount calculated in the previous control cycle; then, the embodiment of the present application will calculate the difference between the preset current frequency limit threshold and the input current, and use the difference as the current error value; then, the embodiment of the present application will calculate the product value of the current error value and the integral regulation coefficient, and use the product value as the initial integral amount; then, the embodiment of the present application calculates the sum of the historical integral amount and the initial integral amount, and uses the sum as the integral amount of the current control cycle.

[0128] It can be understood that the above-mentioned integral adjustment coefficient can be pre-set, and its value can be 10, 20, or other values. The embodiment of the present application does not specifically limit the value of the integral adjustment coefficient.

[0129] In addition, it can be understood that the above-mentioned current frequency limit threshold can be preset, and the embodiment of the present application does not specifically limit the value of the current frequency limit threshold.

[0130] In addition, if Fig. 9 As shown, Fig. 9 1 is a flow chart of a frequency reduction control method provided by another embodiment of the present application. After executing the above step S730 to obtain the integral of the current control cycle, the frequency reduction control method of the embodiment of the present application may also include but is not limited to step S910, step S920 and step S930.

[0131] Step S910, obtaining a second clipping interval;

[0132] Step S920: when the integral amount of the current control cycle is within the second clipping interval, retain the integral amount;

[0133] Step S930: When the integral amount of the current control cycle is outside the second clipping interval, the integral amount is discarded.

[0134] In one embodiment, in combination Figure 2 As shown, the integral adjustment process after adding the limiting means is as follows: First, the embodiment of the present application will obtain the preset integral adjustment coefficient and the historical integral amount calculated in the previous control cycle; then, the embodiment of the present application will calculate the difference between the preset current frequency limit threshold and the input current, and use the difference as the current error value; then, the embodiment of the present application will calculate the product value of the current error value and the integral adjustment coefficient, and use the product value as the initial integral amount; then, the embodiment of the present application will calculate the sum of the historical integral amount and the initial integral amount, and use the sum as the integral amount of the current control cycle. Then, the embodiment of the present application will limit the integral amount, as follows: set a second limiting interval, if the integral amount is less than or equal to the upper limit of the second limiting interval, and greater than or equal to the lower limit of the second limiting interval, then it is considered that the integral amount meets the conditions, and the integral amount is retained; if the integral amount is greater than the upper limit of the second limiting interval, or less than the lower limit of the second limiting interval, then it is considered that the integral amount does not meet the conditions, and the integral amount is discarded.

[0135] It should be noted that the upper limit value of the second limiting interval can be set to 0, so that the expected calculated integral amount can be a negative value, thus ensuring that the final calculated frequency reduction value can be less than or equal to 0, that is, it has a frequency reduction effect instead of frequency increase.

[0136] In addition, it should be noted that the lower limit value of the second clipping interval can be set arbitrarily as needed, and the embodiment of the present application does not specifically limit the lower limit value of the second clipping interval.

[0137] In addition, if Fig.10 As shown, Fig.10 The flowchart of the frequency reduction control method provided by another embodiment of the present application is as follows. Regarding the differential adjustment according to the bus voltage in the above step S430 to obtain the differential amount of the current control cycle, it may include but is not limited to step S1010, step S1020, step S1030 and step S1040.

[0138] Step S1010, obtaining a differential adjustment coefficient;

[0139] Step S1020, low-pass filtering the bus voltage to obtain a historical bus voltage of a historical control period;

[0140] Step S1030, subtract the bus voltage from the historical bus voltage to obtain a voltage error value;

[0141] Step S1040: Obtain the differential amount of the current control cycle according to the voltage error value and the differential adjustment coefficient.

[0142] In one embodiment, in combination Figure 2 As shown, regarding the above-mentioned differential regulation process, it is specifically as follows: first, the embodiment of the present application will obtain a pre-set differential regulation coefficient; then, the embodiment of the present application will perform a low-pass filter on the current actual bus voltage to obtain the historical bus voltage of the previous control cycle; then, the difference between the current actual bus voltage and the historical bus voltage is calculated, and the difference is used as the voltage error value; then, the embodiment of the present application calculates the product value of the voltage error value and the differential regulation coefficient, and uses the product value as the differential amount of the current control cycle.

[0143] It can be understood that the above-mentioned differential adjustment coefficient can be pre-set, and its value can be 0.1, 0.5, or other values. The embodiment of the present application does not specifically limit the value of the differential adjustment coefficient.

[0144] In addition, if Fig.11 As shown, Fig.11 1 is a flow chart of a frequency reduction control method provided by another embodiment of the present application. After obtaining the voltage error value in the above step S1030, the frequency reduction control method of the embodiment of the present application may also include but is not limited to step S1110, step S1120 and step S1130.

[0145] Step S1110, obtaining a third clipping interval;

[0146] Step S1120: when the voltage error value is within the third clipping interval, retain the voltage error value;

[0147] Step S1130: When the voltage error value is outside the third clipping interval, the voltage error value is discarded.

[0148] In one embodiment, in combination Figure 2 As shown, the differential regulation process after adding the limiting means is as follows: first, the embodiment of the present application will obtain a pre-set differential regulation coefficient; then, the embodiment of the present application will perform a low-pass filter on the current actual bus voltage to obtain the historical bus voltage of the previous control cycle; then, the difference between the current actual bus voltage and the historical bus voltage is calculated, and the difference is used as the voltage error value; then, the embodiment of the present application will limit the voltage error value, as follows: a third limiting interval is set, if the voltage error value is less than or equal to the upper limit value of the third limiting interval, and greater than or equal to the lower limit value of the third limiting interval, then the voltage error value is considered to meet the conditions, and the voltage error value is retained; if the voltage error value is greater than the upper limit value of the third limiting interval, or less than the lower limit value of the third limiting interval, then the voltage error value is considered to not meet the conditions, and the voltage error value is discarded. Finally, if the voltage error value is retained, the embodiment of the present application will calculate the product value of the voltage error value and the differential adjustment coefficient, and use the product value as the differential value of the current control cycle.

[0149] It should be noted that the upper limit value of the third limiting interval can be set to 0, so that the expected calculated differential value can be a negative value, thereby ensuring that the final calculated frequency reduction value can be less than or equal to 0, that is, it plays a frequency reduction role instead of frequency increase.

[0150] In addition, it should be noted that the lower limit value of the third clipping interval can be set arbitrarily as needed, and the embodiment of the present application does not specifically limit the lower limit value of the third clipping interval.

[0151] In addition, if Fig.12 As shown, Fig.12 After determining the frequency reduction value according to the proportional amount, integral amount and differential amount in step S330, the frequency reduction control method of the embodiment of the present application may also include but is not limited to step S1210, step S1220 and step S1230.

[0152] Step S1210, obtaining a fourth clipping interval;

[0153] Step S1220: When the frequency drop value is within the fourth clipping interval, retain the frequency drop value;

[0154] Step S1230: When the frequency decrease value is outside the fourth clipping interval, the frequency decrease value is discarded.

[0155] In one embodiment, in combination Figure 2 As shown, after the embodiment of the present application calculates the proportional amount, the integral amount and the differential amount, the proportional amount, the integral amount and the differential amount are combined and added to obtain the required frequency drop value; then, the embodiment of the present application limits the frequency drop value, specifically as follows: a fourth limiting interval is set, if the frequency drop value is less than or equal to the upper limit value of the fourth limiting interval, and is greater than or equal to the lower limit value of the fourth limiting interval, then the frequency drop value is considered to meet the conditions, and the frequency drop value is retained; if the frequency drop value is greater than the upper limit value of the fourth limiting interval, or is less than the lower limit value of the fourth limiting interval, then the frequency drop value is considered to not meet the conditions, and the frequency drop value is discarded.

[0156] It should be noted that the upper limit value of the fourth limiting interval can be set to 0, so that the expected calculated frequency reduction value can be a negative value, that is, it plays a frequency reduction role instead of frequency increase.

[0157] In addition, it should be noted that the lower limit value of the fourth limiting interval can be the maximum frequency value allowed to decrease. The function of this value is to avoid excessive decrease in frequency. The embodiment of the present application does not specifically limit the lower limit value of the fourth limiting interval.

[0158] Based on the frequency reduction control methods of the above-mentioned various embodiments, overall embodiments of the frequency reduction control method of the present application are respectively proposed below.

[0159] In one embodiment, in combination Figure 2 As shown, Figure 2 The parameters in are defined as follows: Iin_thr is used to characterize the current frequency limit threshold, Iin_rms is used to characterize the input current effective value, ΔI is used to characterize the difference between the current frequency limit threshold and the input current effective value, Vn is used to characterize the actual bus voltage in this cycle, Vn-1 is used to characterize the actual bus voltage in the previous cycle, ΔV is used to characterize the difference between the actual bus voltage in this cycle and the actual bus voltage in the previous cycle, F_thr is used to characterize the maximum frequency value allowed to decrease, which is used to avoid excessive frequency decrease, ΔF is used to characterize the calculated frequency decrease value, and Fn is used to characterize the final target frequency.

[0160] Combination Figure 2 As shown, the overall steps of the frequency reduction control method in the embodiment of the present application are as follows:

[0161] (1) Calculate the effective value of the input current Iin_rms and the actual bus voltage Vn in this cycle.

[0162] (2) Proportional-integral regulation based on input current: When the bus voltage drops, the input current will definitely increase significantly. The error ΔI is obtained by subtracting the current frequency limit threshold Iin_thr from the input current effective value Iin_rms. The error ΔI is limited (the upper limit is 0) and multiplied by the proportional regulation coefficient Kp to obtain the proportional amount output in the current control cycle. In addition, the error ΔI is multiplied by the integral regulation coefficient Ki, and the historical integral amount output in a control cycle is added. The integral amount of the current control cycle is obtained after limiting (the upper limit is 0).

[0163] (3) Differential regulation based on bus voltage: The actual bus voltage Vn of the current cycle is low-pass filtered to obtain the actual bus voltage Vn-1 of the previous cycle. The differential error ΔV is obtained by subtracting Vn from Vn-1. The error ΔV is limited (the upper limit is 0) and multiplied by the differential regulation coefficient Kd to obtain the differential amount of the current control cycle.

[0164] (4) Rapid frequency reduction of the compressor operating frequency: The calculated proportional, integral and differential quantities are added together, and the reduced frequency value ΔF is obtained after limiting (lower limit F_thr, upper limit 0), and then the original frequency of the compressor is added to ΔF to obtain the final target frequency Fn, which is used as the input of the motor speed loop control.

[0165] It should be noted that the reason why the upper limit of ΔI and ΔV is 0 is that the calculated proportional quantity, integral quantity, and differential quantity are expected to be negative values, so as to ensure that the final calculated ΔF ≤ 0, that is, it plays a role of frequency reduction instead of frequency increase. If the upper limit is not limited to 0, when the grid voltage rises, ΔI and ΔV are positive values, and then ΔF before the limit is positive.

[0166] In addition, it should be noted that different setting values ​​can be set according to the air conditioner model, usage environment and other conditions. In the embodiment of the present application, the following values ​​can be set but are not limited to them, as shown in the following Table 1:

[0167] Table 1

[0168] Iin_thr / A Proportional coefficient Kp Integration coefficient Ki Differential coefficient Kd Threshold F_thr / hz 8-15A 1-10 10-30 0.1-1 20-50

[0169] In addition, if Figures 13 to 15 As shown, Fig.13 This is the existing AC input voltage drop test diagram; Fig.14 This is an AC input voltage drop test diagram of an embodiment of the present application; Fig.15 is a current waveform diagram when the frequency is reduced to the lowest point during the AC input voltage drop test of the embodiment of the present application;

[0170] in, Fig.13 The waveform a1 in the figure is used to represent the compressor current, the waveform b1 is used to represent the input current, and the waveform c1 is used to represent the frequency; Fig.14 and Fig.15 The waveform a2 is used to represent the compressor current, the waveform b2 is used to represent the input current, the waveform c2 is used to represent the calculated frequency drop value ΔF, and the horizontal line d2 is a mark of the fast frequency reduction function.

[0171] Depend on Fig.13 It can be seen that for the existing control scheme, when a voltage drop occurs, for example, when the input voltage drops from 264V to 150V within 0.5s, the input current suddenly increases to the protection current threshold, triggering an overcurrent protection shutdown.

[0172] However, by Fig.14 It can be seen that after adopting the control scheme of the embodiment of the present application, when a voltage drop occurs, the air conditioner does not report a fault and shuts down. For example, the input voltage drops from 264V to 150V within 0.5s, and the air conditioner does not report a fault and shuts down. The compressor frequency drop value ΔF calculated within 0.57s is 26.2hz, and the compressor frequency drops from 96.6hz to 70.4hz, and the frequency reduction rate reaches 46hz / s, while the fastest frequency reduction rate of the existing control scheme is only 1hz / s, and the improvement effect is obvious.

[0173] Based on the frequency reduction control methods of the above-mentioned embodiments, various embodiments of the controller, control circuit, air conditioner and computer-readable storage medium of the present application are respectively proposed below.

[0174] like Fig.16 As shown, Fig.16 300 is a schematic diagram of a controller for executing a frequency reduction control method provided by an embodiment of the present application. The controller 300 implemented in the present application includes: a processor 310, a memory 320, and a computer program stored in the memory 320 and executable on the processor 310, wherein: Fig.16 In the figure, a processor 310 and a memory 320 are taken as an example.

[0175] The processor 310 and the memory 320 may be connected via a bus or other means. Fig.16 The example of connecting through bus is taken in the following.

[0176] The memory 320, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs and non-transitory computer executable programs. In addition, the memory 320 may include a high-speed random access memory, and may also include a non-transitory memory, such as at least one disk storage device, a flash memory device, or other non-transitory solid-state storage device. In some embodiments, the memory 320 may optionally include a memory 320 remotely arranged relative to the processor 310, and these remote memories 320 may be connected to the controller 300 via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0177] Those skilled in the art will understand that Fig.16 The device structure shown in the figure does not constitute a limitation on the controller 300, and may include more or less components than shown in the figure, or combine certain components, or arrange the components differently.

[0178] exist Fig.16 In the controller 300 shown, the processor 310 can be used to call the frequency reduction control program stored in the memory 320, so as to implement the above-mentioned frequency reduction control method. Specifically, the non-transient software program and instructions required to implement the frequency reduction control method of the above-mentioned embodiment are stored in the memory 320, and when executed by the processor 310, the frequency reduction control method of the above-mentioned embodiment is executed.

[0179] It is worth noting that since the controller 300 of the embodiment of the present application can execute the frequency reduction control method of any of the above-mentioned embodiments, the specific implementation manner and technical effects of the controller 300 of the embodiment of the present application can refer to the specific implementation manner and technical effects of the frequency reduction control method of any of the above-mentioned embodiments.

[0180] In addition, an embodiment of the present application further provides a control circuit, comprising the controller of any of the above embodiments.

[0181] It is worth noting that since the control circuit of the embodiment of the present application includes the controller of any of the above-mentioned embodiments, and the controller of the above-mentioned embodiments is capable of executing the frequency reduction control method of any of the above-mentioned embodiments, the specific implementation manner and technical effects of the control circuit of the embodiment of the present application can refer to the specific implementation manner and technical effects of the frequency reduction control method of any of the above-mentioned embodiments.

[0182] In addition, an embodiment of the present application further provides an air conditioner, comprising the control circuit of any of the above embodiments.

[0183] It is worth noting that since the air conditioner of the embodiment of the present application includes the control circuit of the above-mentioned embodiment, and the control circuit of the above-mentioned embodiment includes the controller of the above-mentioned embodiment, and the controller of the above-mentioned embodiment can execute the frequency reduction control method of any of the above-mentioned embodiments, therefore, the specific implementation manner and technical effects of the air conditioner of the embodiment of the present application can refer to the specific implementation manner and technical effects of the frequency reduction control method of any of the above-mentioned embodiments.

[0184] In addition, an embodiment of the present application further provides a computer-readable storage medium, which stores computer-executable instructions, and the computer-executable instructions are used to execute the above-described frequency reduction control method. Figures 3 to 12 The method steps in .

[0185] It is worth noting that since the computer-readable storage medium of the embodiment of the present application can execute the frequency reduction control method of any of the above-mentioned embodiments, the specific implementation methods and technical effects of the computer-readable storage medium of the embodiment of the present application can refer to the specific implementation methods and technical effects of the frequency reduction control method of any of the above-mentioned embodiments.

[0186] It will be appreciated by those skilled in the art that all or some of the steps and systems in the disclosed method above may be implemented as software, firmware, hardware and appropriate combinations thereof. Some physical components or all physical components may be implemented as software executed by a processor, such as a central processing unit, a digital signal processor or a microprocessor, or may be implemented as hardware, or may be implemented as an integrated circuit, such as an application specific integrated circuit. Such software may be distributed on a computer-readable medium, which may include a computer storage medium (or a non-transitory medium) and a communication medium (or a temporary medium). As known to those skilled in the art, the term computer storage medium includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules or other data). Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tapes, disk storage or other magnetic storage devices, or any other medium that may be used to store desired information and may be accessed by a computer. Furthermore, it is well known to those skilled in the art that communication media generally include computer readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism, and may include any information delivery media.

[0187] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, the terms "connection", "direct connection", "indirect connection", "fixed connection", "installation", and "assembly" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; the terms "installation", "connection", and "fixed connection" can be a direct connection, or an indirect connection through an intermediate medium, or the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0188] Although the implementation methods disclosed in this application are as above, the contents are only implementation methods adopted to facilitate understanding of this application, and are not intended to limit this application. Any technician in the field to which this application belongs can make any modifications and changes in the form and details of implementation without departing from the spirit and scope disclosed in this application, but the scope of patent protection of this application shall still be defined by the attached claims.

[0189] The above is a specific description of the preferred implementation of the present application, but the present application is not limited to the above implementation mode. Technical personnel familiar with the field can also make various equivalent modifications or substitutions under the shared conditions without violating the spirit of the present application. These equivalent modifications or substitutions are all included in the scope defined by the claims of the present application.

Claims

1. A frequency reduction control method, characterized in that: Applied to a control circuit, the control circuit is used to control the operation of a motor, and the frequency reduction control method includes: Obtaining the original frequency of the motor and the input current and bus voltage of the control circuit; Perform PID adjustment according to the input current and the bus voltage to obtain a proportional quantity, an integral quantity and a differential quantity of a current control cycle; Determine a frequency drop value according to the proportional amount, the integral amount and the derivative amount; The target frequency is determined according to the frequency reduction value and the original frequency, and the motor is controlled to reduce the frequency from the original frequency to the target frequency.

2. The frequency reduction control method according to claim 1, characterized in that: The PID adjustment is performed according to the input current and the bus voltage to obtain the proportional quantity, integral quantity and differential quantity of the current control cycle, including: Perform proportional adjustment according to the input current and the preset current frequency limit threshold to obtain a proportional amount of the current control cycle; Performing integral adjustment according to the input current and the preset current frequency limiting threshold to obtain an integral amount of the current control cycle; A differential adjustment is performed according to the bus voltage to obtain a differential amount of the current control cycle.

3. The frequency reduction control method according to claim 2, characterized in that: The proportional adjustment is performed according to the input current and the preset current frequency limiting threshold to obtain the proportional amount of the current control cycle, including: Get the proportional adjustment coefficient; Subtracting the preset current frequency limiting threshold from the input current to obtain a current error value; The proportional amount of the current control cycle is obtained according to the current error value and the proportional adjustment coefficient.

4. The frequency reduction control method according to claim 3, characterized in that: After obtaining the current error value, the frequency reduction control method further includes: Get the first clipping interval; When the current error value is within the first amplitude limiting interval, retaining the current error value; When the current error value is outside the first amplitude limiting interval, the current error value is discarded.

5. The frequency reduction control method according to claim 2, characterized in that: The step of performing integral adjustment according to the input current and the preset current frequency limiting threshold to obtain the integral amount of the current control cycle includes: Obtain the integral adjustment coefficient and the historical integral amount of the historical control cycle; Subtracting the preset current frequency limiting threshold from the input current to obtain a current error value; The integral amount of the current control cycle is obtained according to the current error value, the integral adjustment coefficient and the historical integral amount.

6. The frequency reduction control method according to claim 5, characterized in that: The step of obtaining the integral amount of the current control cycle according to the current error value, the integral adjustment coefficient and the historical integral amount includes: Calculating the product of the current error value and the integral adjustment coefficient to obtain an initial integral amount; The sum of the initial integral amount and the historical integral amount is calculated to obtain the integral amount of the current control cycle.

7. The frequency reduction control method according to claim 5 or 6, characterized in that: After obtaining the integral amount of the current control cycle, the frequency reduction control method further includes: Obtain the second clipping interval; When the integral amount of the current control cycle is within the second clipping interval, retaining the integral amount; When the integral amount of the current control cycle is outside the second clipping interval, the integral amount is discarded.

8. The frequency reduction control method according to claim 2, characterized in that: The differential adjustment is performed according to the bus voltage to obtain the differential amount of the current control cycle, including: Get the differential adjustment coefficient; Performing low-pass filtering on the bus voltage to obtain a historical bus voltage of a historical control period; Subtracting the bus voltage from the historical bus voltage to obtain a voltage error value; The differential amount of the current control cycle is obtained according to the voltage error value and the differential adjustment coefficient.

9. The frequency reduction control method according to claim 8, characterized in that: After obtaining the voltage error value, the frequency reduction control method further includes: Get the third clipping interval; When the voltage error value is within the third clipping interval, retaining the voltage error value; When the voltage error value is outside the third clipping interval, the voltage error value is discarded.

10. The frequency reduction control method according to claim 1, characterized in that: After determining the frequency reduction value according to the proportional amount, the integral amount and the differential amount, the frequency reduction control method further includes: Get the fourth clipping interval; When the frequency decrease value is within the fourth limiting interval, retaining the frequency decrease value; When the frequency drop value is outside the fourth clipping interval, the frequency drop value is discarded.

11. A control circuit, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the frequency reduction control method according to any one of claims 1 to 10 when executing the computer program.

12. An air conditioner, characterized in that: Comprising the control circuit as claimed in claim 11.

13. A computer-readable storage medium, characterized in that: Computer executable instructions are stored, and the computer executable instructions are used to execute the frequency reduction control method according to any one of claims 1 to 10.

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