A pure electric intelligent air conditioner inverter carrier frequency control method and system

Abstract

The present invention relates to the field of air conditioning control technology, and specifically to a pure electric intelligent air conditioning inverter carrier frequency control method and system, the method comprising: judging whether to switch the air conditioning from a segmented fixed carrier frequency control mode to an adaptive carrier frequency control mode according to the load demand at each moment within a preset time in the initial operation stage of the air conditioning; in the stable operation stage of the air conditioning, obtaining the mode switching factor corresponding to the sampling moment according to the preset sampling moment, the moment before the sampling moment, and the moment after the sampling moment, the average value of the load demand before the sampling moment, and the load demand at the moment after the sampling moment, when the normalized value of the mode switching factor has a cross-mode switching threshold behavior, the air conditioning is switched to another frequency control mode, and the frequency value of the other frequency control mode is obtained. The present invention can adaptively determine the frequency control mode according to the load demand change of the external environment during the operation of the air conditioner.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioning control, and in particular to a carrier frequency control method and system for a pure electric intelligent air conditioning inverter. Background Art

[0002] Pure electric intelligent air conditioners are air conditioner products that combine pure electric technology with intelligent control technology. They have the advantages of high efficiency, energy saving, environmental sustainability, and year-round applicability. As a key component for regulating the operating speed of the air conditioner compressor, the air conditioner inverter can achieve fine management of air conditioner temperature, energy efficiency, noise and other dimensions. Among them, the carrier frequency plays a core role. It involves the modulation frequency of the power waveform by the inverter circuit inside the inverter, and is a key factor in optimizing the control performance of the compressor. The appropriate carrier frequency control strategy not only ensures the comfort of use, but also effectively reduces energy consumption and noise levels, and enhances the overall stability of the system.

[0003] At present, the methods for adjusting the carrier frequency of the air conditioner inverter are mainly divided into two categories: segmented fixed carrier frequency control mode and adaptive carrier frequency control mode. Although the segmented fixed carrier frequency control mode is easy to implement, it lacks flexibility and is difficult to respond quickly to real-time changes in the load; while the adaptive carrier frequency control mode can be flexibly adjusted according to changing conditions, but the frequent carrier frequency changes bring about problems such as increased power consumption and decreased stability. Both methods have their own limitations in carrier frequency control. Summary of the invention

[0004] In order to solve the technical problems that the current method for adjusting the carrier frequency of the air conditioner inverter has insufficient flexibility, high power consumption, and insufficient stability, the purpose of the present invention is to provide a pure electric intelligent air conditioner inverter carrier frequency control method, and the technical scheme adopted is as follows:

[0005] The air flow degree is obtained according to the first air pressure data obtained at the air supply outlet of the air conditioner, the second air pressure data obtained at the air return outlet of the air conditioner, and the air flow velocity data inside the vehicle, and the load demand degree is obtained according to the air flow degree, the temperature data inside and outside the vehicle, and the humidity data inside and outside the vehicle;

[0006] Obtaining the frequency value of the segmented fixed carrier frequency control mode in the initial operation stage of the air conditioner according to the load value corresponding to the load demand at the first sampling moment, the preset initial frequency value, and the load value corresponding to the initial frequency value, and determining whether to switch the air conditioner from the segmented fixed carrier frequency control mode to the adaptive carrier frequency control mode according to the load demand at each moment within the preset time in the initial operation stage of the air conditioner;

[0007] During the stable operation stage of the air conditioner, the mode switching factor is obtained based on the degree of change of the load demand at a preset sampling moment and the moment before and after it, the average value of the load demand before the sampling moment, and the load demand at the moment after the sampling moment. When the normalized value of the mode switching factor crosses the mode switching threshold, the current frequency control mode of the air conditioner is switched to another frequency control mode.

[0008] Further, judging whether to switch the air conditioner from the segmented fixed carrier frequency control mode to the adaptive carrier frequency control mode according to the load demand at each moment within a preset time in the initial operation stage of the air conditioner includes:

[0009] Within a preset time of the initial operation stage of the air conditioner, the degree of change of the load demand is obtained according to the load demand degree at each moment before the nth sampling moment; when the degree of change of the load demand is greater than a preset conversion threshold, the air conditioner switches from the segmented fixed carrier frequency control mode to the adaptive carrier frequency control mode, wherein n is a positive integer greater than or equal to 2.

[0010] Furthermore, the process of obtaining the air flow degree includes:

[0011] Subtracting the second air pressure data from the first air pressure data and dividing the resultant value by the second air pressure data to obtain a first ratio;

[0012] The air flow degree is obtained by multiplying the inverse of the absolute value of the first ratio by the in-vehicle air flow velocity data.

[0013] Furthermore, the process of acquiring the load demand degree includes:

[0014] The absolute value of the difference between the temperature data inside the vehicle and the temperature data outside the vehicle is recorded as the temperature difference value, and the absolute value of the difference between the humidity data inside the vehicle and the humidity data outside the vehicle is recorded as the humidity difference value;

[0015] The temperature difference value is multiplied by the humidity difference value to obtain the temperature and humidity difference value inside and outside the vehicle;

[0016] The load demand is obtained by dividing the difference between the temperature and humidity inside and outside the vehicle by the air flow degree.

[0017] Furthermore, the process of obtaining the frequency value of the segmented fixed carrier frequency control mode in the initial operation stage of the air conditioner includes:

[0018] The load value corresponding to the load demand at the first sampling moment is multiplied by the initial frequency value and then divided by the load value corresponding to the initial frequency value to obtain the frequency value of the segmented fixed carrier frequency control mode in the initial operation stage of the air conditioner.

[0019] Furthermore, the process of obtaining the load demand change degree includes:

[0020] Obtaining the absolute value of the load demand at the i+1th moment minus the load demand at the ith moment, and calculating the sum of the absolute values, wherein the value of i ranges from 1 to n-1, and n represents the nth sampling moment;

[0021] The load demand change degree is obtained by dividing the average value of the load demand before the nth sampling moment by the load demand at the first sampling moment and multiplying the average value by the sum of the absolute values.

[0022] Furthermore, the process of acquiring the mode switching factor includes:

[0023] Recording the absolute value of the load demand change degree at the sampling moment minus the load demand change degree at a moment before the sampling moment as a first absolute value;

[0024] The absolute value of the load demand change degree at the sampling moment minus the load demand change degree at a moment after the sampling moment is recorded as a second absolute value;

[0025] Dividing the average value of the load demand before the sampling moment by the load demand at a moment after the sampling moment to obtain a first ratio;

[0026] The first absolute value is divided by the second absolute value and then multiplied by the first ratio to obtain the mode switching factor at the sampling moment.

[0027] Furthermore, the method further comprises:

[0028] When the other frequency control mode is the segmented fixed carrier frequency control mode, the frequency value at a moment before the sampling moment is multiplied by the mode switching factor at a moment after the sampling moment, and then divided by the mode switching threshold to obtain the frequency value of the segmented fixed carrier frequency control mode.

[0029] Furthermore, the method further comprises:

[0030] When the other frequency control mode is the adaptive carrier frequency control mode, the frequency value at the moment before the sampling moment is multiplied by the load demand at the sampling moment, and then divided by the load demand at the moment before the sampling moment as the frequency value of the adaptive carrier frequency control mode.

[0031] The embodiment of the present invention further provides a pure electric intelligent air conditioner inverter carrier frequency control system, the system comprising:

[0032] A load demand module, used to obtain the air flow degree according to the first air pressure data obtained at the air supply outlet of the air conditioner, the second air pressure data obtained at the air return outlet of the air conditioner, and the air flow velocity data in the vehicle, and to obtain the load demand degree according to the air flow degree, the temperature data inside and outside the vehicle, and the humidity data inside and outside the vehicle;

[0033] The frequency control module of the initial operation stage of the air conditioner is used to obtain the frequency value of the segmented fixed carrier frequency control mode of the initial operation stage of the air conditioner according to the load value corresponding to the load demand at the first sampling moment, the preset initial frequency value and the load value corresponding to the initial frequency value, and determine whether to switch the air conditioner from the segmented fixed carrier frequency control mode to the adaptive carrier frequency control mode according to the load demand at each moment within the preset time of the initial operation stage of the air conditioner;

[0034] The frequency control module in the stable operation stage of the air conditioner is used to obtain the mode switching factor according to the degree of change of the load demand at a preset sampling moment and the moment before and after the sampling moment, the average value of the load demand before the sampling moment, and the load demand at the moment after the sampling moment. When the normalized value of the mode switching factor crosses the mode switching threshold, the current frequency control mode of the air conditioner is switched to another frequency control mode.

[0035] The present invention has the following beneficial effects:

[0036] First, the air flow degree is obtained according to the first air pressure data obtained at the air supply outlet of the air conditioner, the second air pressure data obtained at the air return outlet of the air conditioner, and the air flow velocity data in the vehicle, and the load demand degree is obtained according to the air flow degree, the temperature data inside and outside the vehicle, and the humidity data inside and outside the vehicle. The load demand degree is obtained for subsequent determination of different frequency control modes.

[0037] Then, the frequency value of the segmented fixed carrier frequency control mode in the initial operation stage of the air conditioner is obtained according to the load value corresponding to the load demand at the first sampling moment, the preset initial frequency value, and the load value corresponding to the initial frequency value, and whether to switch the air conditioner from the segmented fixed carrier frequency control mode to the adaptive carrier frequency control mode is determined according to the load demand at each moment within the preset time in the initial operation stage of the air conditioner. The segmented fixed carrier frequency control mode is used as the default in the initial operation stage of the air conditioner, and whether the frequency control mode needs to be switched is determined according to the load demand within the preset time in the initial operation stage of the air conditioner.

[0038] Finally, in the stable operation stage of the air conditioner, the mode switching factor is obtained according to the load demand change degree at the preset sampling moment and the moment before and after, the average value of the load demand degree before the sampling moment, and the load demand degree at the moment after the sampling moment. When the normalized value of the mode switching factor crosses the mode switching threshold, the current frequency control mode of the air conditioner is switched to another frequency control mode. This step is used to determine whether to switch the frequency control mode.

[0039] By adopting the present invention, different frequency control modes can be adaptively determined according to the load demand changes of the external environment during the operation of the air conditioner, and the power consumption can be reduced as much as possible while ensuring the efficient operation of the air conditioner. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0041] Figure 1 A flow chart of a carrier frequency control method for a pure electric intelligent air conditioner inverter provided by the first embodiment of the present invention;

[0042] Figure 2 A flow chart of the process of obtaining the air flow degree provided by the second embodiment of the present invention;

[0043] Figure 3 A flowchart of a process for obtaining the load demand degree provided in the third embodiment of the present invention;

[0044] Figure 4 A flowchart of a process for obtaining the load demand variation degree provided in the fourth embodiment of the present invention;

[0045] Figure 5 A flowchart of a process for obtaining the mode switching factor provided in the fifth embodiment of the present invention;

[0046] Figure 6 A schematic diagram of a carrier frequency control system of a pure electric intelligent air conditioner inverter provided in the sixth embodiment of the present invention. DETAILED DESCRIPTION

[0047] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following is a detailed description of the pure electric intelligent air conditioner inverter carrier frequency control method and system proposed by the present invention, its specific implementation method, structure, features and effects, in combination with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.

[0048] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0049] The specific scheme of a pure electric intelligent air conditioner inverter carrier frequency control method and system provided by the present invention is described in detail below with reference to the accompanying drawings.

[0050] See also Figure 1 , which shows a flow chart of a pure electric intelligent air conditioner inverter carrier frequency control method provided by the first embodiment of the present invention, the method comprising:

[0051] S101. Obtain the degree of air flow based on the first air pressure data obtained at the air supply outlet of the air conditioner, the second air pressure data obtained at the air return outlet of the air conditioner, and the air flow velocity data inside the vehicle, and obtain the load demand based on the air flow degree, the temperature data inside and outside the vehicle, and the humidity data inside and outside the vehicle.

[0052] First, when controlling the vehicle's electric intelligent air conditioner, the real-time temperature and humidity data inside and outside the vehicle can be obtained through the temperature and humidity sensors installed inside and outside the vehicle, and the differential pressure sensor can be used to accurately measure the air pressure at the air supply and return outlets of the air conditioner and the air flow velocity data in the vehicle (the sampling interval is 0.25 seconds). Of course, air pressure sensors can also be installed at the air supply and return outlets of the air conditioner, and wind speed sensors can be installed in the vehicle to obtain air pressure data and air flow velocity data.

[0053] Since the air conditioner inverter is usually used to adjust the operating speed of the air conditioner compressor, that is, the larger the frequency, the stronger the corresponding air conditioner heating / cooling capacity. At the same time, if the air conditioner's heating / cooling capacity is stronger, it means that the air conditioner operating load at the corresponding moment is greater. The air conditioner operating load is determined by the environment.

[0054] The process of obtaining the air flow degree will be described in detail in the second embodiment and will not be repeated here.

[0055] The process of obtaining the load demand will be described in detail in the third embodiment and will not be repeated here.

[0056] S102. Obtain the frequency value of the segmented fixed carrier frequency control mode in the initial operation stage of the air conditioner according to the load value corresponding to the load demand at the first sampling moment, the preset initial frequency value, and the load value corresponding to the initial frequency value, and determine whether to switch the air conditioner from the segmented fixed carrier frequency control mode to the adaptive carrier frequency control mode according to the load demand at each moment within the preset time in the initial operation stage of the air conditioner.

[0057] The load demand determines the size of the inverter carrier frequency. The higher the load demand, the larger the carrier frequency is required to increase the speed of the air-conditioning compressor to enhance the cooling / heating effect. Conversely, the carrier frequency can be appropriately reduced to save energy.

[0058] Since the segmented fixed carrier frequency control mode has poor coping ability for situations where the load demand changes frequently and the degree of change is large, and the adaptive carrier frequency control mode is relatively more flexible, it will increase power consumption when the load demand changes slowly and the degree of change is small. Therefore, the present invention combines the two methods, and uses the adaptive carrier frequency control method to increase the adjustment adaptability during the period when the load demand changes frequently, and uses the segmented fixed carrier frequency control mode during the period when the load demand changes slowly to ensure frequency adaptation while reducing its power consumption.

[0059] During the initial operation of the air conditioner, related sensors (temperature and humidity sensors, air pressure sensors, etc.) begin to collect data to calculate the real-time load demand. During this stage, the air conditioner operation and the load demand calculation are carried out in parallel. Therefore, it is impossible to determine the control mode of the carrier frequency specifically. In this default initial operation stage of the air conditioner, the segmented fixed carrier frequency control mode is used.

[0060] Specifically, the process of obtaining the frequency value of the segmented fixed carrier frequency control mode in the initial operation stage of the air conditioner includes:

[0061] The load value corresponding to the load demand at the first sampling moment is multiplied by the initial frequency value and then divided by the load value corresponding to the initial frequency value to obtain the frequency value of the segmented fixed carrier frequency control mode in the initial operation stage of the air conditioner.

[0062] The frequency value of the segmented fixed carrier frequency control mode in the initial operation stage of the air conditioner can be expressed by the formula:

[0063] ;

[0064] Among them, the represents the frequency value of the segmented fixed carrier frequency control mode in the initial operation stage of the air conditioner, represents the initial frequency value, the represents the load value corresponding to the load demand at the first sampling moment, Indicates the load value corresponding to the initial frequency value. The initial frequency value And the load value corresponding to the initial frequency value These are preset values.

[0065] As the air conditioner is at the frequency value Operation, segmented fixed carrier frequency control mode is not necessarily suitable for real-time load changes, the load demand changes at the initial moment may be more frequent and more suitable for adaptive carrier frequency control mode. Therefore, it is necessary to analyze the real-time load demand changes to determine whether to switch modes.

[0066] Specifically, judging whether to switch the air conditioner from the segmented fixed carrier frequency control mode to the adaptive carrier frequency control mode according to the load demand at each moment within a preset time in the initial operation stage of the air conditioner includes:

[0067] Within a preset time of the initial operation stage of the air conditioner, the degree of change of the load demand is obtained according to the load demand degree at each moment before the nth sampling moment; when the degree of change of the load demand is greater than a preset conversion threshold, the air conditioner switches from the segmented fixed carrier frequency control mode to the adaptive carrier frequency control mode, wherein n is a positive integer and is greater than or equal to 2.

[0068] The process of obtaining the load demand variation degree will be described in detail in the fourth embodiment and will not be repeated here.

[0069] The conversion threshold can be set independently, and is preferably set to 0.8.

[0070] The preset time may be set to two minutes.

[0071] If the condition that the load demand change degree is greater than the preset switching threshold is not met within the preset time of the initial operation stage of the air conditioner, the mode will not be switched and the air conditioner will continue to operate in the segmented fixed carrier frequency control mode.

[0072] S103. During the stable operation stage of the air conditioner, a mode switching factor is obtained based on the degree of change in load demand at a preset sampling moment and the moment before and after it, the average value of the load demand before the sampling moment, and the load demand at the moment after the sampling moment. When the normalized value of the mode switching factor crosses the mode switching threshold, the current frequency control mode of the air conditioner is switched to another frequency control mode.

[0073] As the initial operation phase of the air conditioner ends, it enters the stable operation phase. At this time, the possible mode switching time during the operation can be determined based on the historical load demand changes. If the load demand changes from frequent fluctuations to stable small fluctuations, it should be switched to the segmented fixed carrier frequency control mode; if the load demand changes from stable small fluctuations to frequent fluctuations, it should be switched to the adaptive carrier frequency control mode.

[0074] The process of obtaining the mode switching factor will be described in detail in the fifth embodiment and will not be repeated here.

[0075] The mode switching threshold can be set independently, and is preferably set to 0.65.

[0076] Crossing the mode switching threshold behavior means that the normalized value of the mode switching factor changes from greater than or equal to 0.65 to less than 0.65, or the normalized value of the mode switching factor changes from less than 0.65 to greater than or equal to 0.65.

[0077] It should be noted that there are only two frequency control modes of the air conditioner, including: the segmented fixed carrier frequency control mode or the adaptive carrier frequency control mode.

[0078] Specifically, when the other frequency control mode is the segmented fixed carrier frequency control mode, the process of acquiring the frequency value of the segmented fixed carrier frequency control mode includes:

[0079] The frequency value of the segmented fixed carrier frequency control mode is obtained by multiplying the frequency value at a moment before the sampling moment by the mode switching factor at a moment after the sampling moment and then dividing the result by the mode switching threshold.

[0080] The frequency value of the segmented fixed carrier frequency control mode can be expressed by the formula:

[0081] ;

[0082] Among them, the represents the frequency value of the segmented fixed carrier frequency control mode, the represents the frequency value at the moment before the sampling moment (i.e., the x-1th sampling moment), represents the mode switching factor at a moment after the sampling moment (i.e., the x+1th sampling moment), represents the mode switching threshold.

[0083] If the control mode is switched to the segmented fixed carrier frequency control mode, it means that the load demand changes slightly and smoothly. Therefore, the carrier frequency should be appropriately reduced. It represents the degree to which it needs to be reduced, so it is used as the weight to obtain a fixed frequency value.

[0084] Specifically, when the other frequency control mode is the adaptive carrier frequency control mode, the frequency of the adaptive carrier frequency control mode includes:

[0085] The frequency value of the adaptive carrier frequency control mode is obtained by multiplying the frequency value at a moment before the sampling moment by the load demand at the sampling moment and then dividing the multiplication by the load demand at the moment before the sampling moment.

[0086] The frequency value of the adaptive carrier frequency control mode can be expressed by the formula:

[0087] ;

[0088] Among them, the represents the frequency value of the adaptive carrier frequency control mode, the represents the frequency value at the moment before the sampling moment (i.e., the x-1th sampling moment), represents the load demand at the xth sampling moment, Indicates the load demand at the moment before the sampling moment (i.e., the x-1th sampling moment).

[0089] The carrier frequency is adjusted in real time by using the difference in real-time load demand as a weight to provide flexibility in responding to large changes in load demand.

[0090] The air flow characteristics of the air conditioner's environment can affect its load requirements. Poor air flow can cause certain areas to overheat or overcool, forcing the air conditioner to adjust its output more frequently, while good air flow can help evenly distribute the temperature inside the car and reduce the air conditioner's load.

[0091] Figure 2 The flowchart of the process of obtaining the air flow degree provided in the second embodiment of the present invention includes:

[0092] S201. Subtract the second air pressure data from the first air pressure data, and then divide the resultant value by the second air pressure data to obtain a first ratio.

[0093] The first ratio can be expressed as: , wherein the Indicates The first air pressure data at the time Indicates The second air pressure data at the time.

[0094] S202. Multiply the inverse of the absolute value of the first ratio by the in-vehicle air flow velocity data to obtain the air flow degree.

[0095] The degree of air flow can be expressed by the formula:

[0096] ;

[0097] Among them, the Indicates The in-vehicle airflow velocity data at the time, Indicates The degree of air flow at the moment.

[0098] Said It represents the pressure difference between the two air outlets (supply outlet and return outlet) of the air conditioner at the corresponding moment. If the air pressure in the environment is more uniform, the air pressure at the two corresponding positions will be more similar. Therefore, the larger the value, the more uneven the air pressure in the environment, and the smaller the corresponding air flow. Combined with the air flow velocity data in the car , the greater the air flow velocity, the greater the degree of air flow. The larger the value, the The greater the air flow in the environment where the air conditioner is located at any time, the smaller the air flow is.

[0099] The greater the air flow rate, the smaller the air conditioning load demand. At the same time, since the air conditioning load size is mainly determined by temperature and humidity, the real-time air conditioning load demand can be determined by combining the temperature and humidity difference with the air flow rate.

[0100] Figure 3 The flowchart of the process of obtaining the load demand provided by the third embodiment of the present invention includes:

[0101] S301. Record the absolute value of the difference between the temperature data inside the vehicle and the temperature data outside the vehicle as the temperature difference value, and record the absolute value of the difference between the humidity data inside the vehicle and the humidity data outside the vehicle as the humidity difference value.

[0102] The temperature difference value can be expressed as:

[0103] ;

[0104] Among them, the Indicates The in-vehicle temperature data at the time, Indicates The outside temperature data at the time, represents the absolute value function, the subscript w represents inside the vehicle, and the subscript o represents outside the vehicle.

[0105] The humidity difference value can be expressed as:

[0106] ;

[0107] Among them, the Indicates The in-vehicle humidity data at the time, Indicates The outside humidity data at the time, represents the absolute value function, the subscript w represents inside the vehicle, and the subscript o represents outside the vehicle.

[0108] S302: Multiply the temperature difference value by the humidity difference value to obtain the temperature and humidity difference value inside and outside the vehicle.

[0109] The difference between the temperature and humidity inside and outside the vehicle can be expressed as: .

[0110] S303: Divide the difference in temperature and humidity inside and outside the vehicle by the value of the air flow degree as the load demand.

[0111] The load demand can be expressed as:

[0112] ;

[0113] Among them, the Indicates The load demand at the time, Indicates The degree of air flow at the moment.

[0114] Represents the real-time temperature and humidity difference between the inside and outside of the car. The greater the difference, the greater the load required to compensate for the difference. The larger the value, the greater the corresponding load demand, and combined with the air flow degree to obtain .therefore, The size of reflects the relative quantitative result of the real-time load required by the environment for air conditioning. Different frequency control modes can be determined based on the changing characteristics of load demand.

[0115] Figure 4 The flowchart of the process of obtaining the load demand variation degree provided in the fourth embodiment of the present invention includes:

[0116] S401. Obtain the absolute value of the load demand at the i+1th moment minus the load demand at the ith moment, and calculate the sum of the absolute values, wherein the value of i is 1 to n-1, and n represents the nth sampling moment.

[0117] The sum of the absolute values ​​can be expressed as:

[0118] ;

[0119] Among them, the represents the load demand at the i+1th moment, represents the load demand at the i-th moment.

[0120] S402: The load demand change degree is obtained by dividing the average value of the load demand before the nth sampling moment by the load demand at the first sampling moment and multiplying the result by the sum of the absolute values.

[0121] The load demand variation degree can be expressed as:

[0122] ;

[0123] Among them, the represents the average value of the load demand before the nth sampling time, represents the load demand at the first sampling moment, represents a normalization function, preferably a range normalization function, Indicates The load demand change degree before the sampling time.

[0124] Said Represents the degree of fluctuation of real-time load demand. The larger the value, the more discrete and unsmooth the real-time load demand fluctuation is. It represents the average relative fluctuation degree during this period. The larger the value is, the corresponding load demand gradually increases, and the corresponding load demand changes more greatly.

[0125] As the initial operation phase of the air conditioner (the preset time after the air conditioner is turned on) ends, the air conditioner begins to enter the stable operation phase. At this time, the possible mode switching time during the operation process can be determined based on the historical load demand change degree. If the load demand changes from frequent fluctuations to stable small fluctuations, it should be switched to the segmented fixed carrier frequency control mode; if the load demand changes from stable small fluctuations to frequent fluctuations, it should be switched to the adaptive carrier frequency control mode.

[0126] Figure 5 The flowchart of the process of obtaining the mode switching factor provided in the fifth embodiment of the present invention includes:

[0127] S501. Record the absolute value of the load demand change degree at the sampling moment minus the load demand change degree at a moment before the sampling moment as a first absolute value.

[0128] The first absolute value can be expressed as:

[0129] ;

[0130] Among them, the represents the load demand change degree at the xth sampling moment, Indicates the degree of change of the load demand at the x-1th sampling moment.

[0131] S502. Record the absolute value of the load demand change degree at the sampling moment minus the load demand change degree at a moment after the sampling moment as the second absolute value.

[0132] The second absolute value can be expressed as:

[0133] ;

[0134] Among them, the represents the load demand change degree at the xth sampling moment, Indicates the degree of change of the load demand at the x+1th sampling moment.

[0135] S503. Divide the average value of the load demand before the sampling moment by the load demand at one moment after the sampling moment to obtain a first ratio.

[0136] The first ratio can be expressed as:

[0137] ;

[0138] Among them, the represents the average value of the load demand before the xth sampling time, It represents the load demand at the moment after the x-th sampling moment (ie, the x+1-th sampling moment).

[0139] S504. After dividing the first absolute value by the second absolute value, multiplying the first ratio by the first ratio to obtain the mode switching factor at the sampling moment.

[0140] The mode switching factor can be expressed as:

[0141] ;

[0142] Among them, the represents the mode switching factor at the xth sampling moment.

[0143] represents the difference in the load demand change degree before and after the xth sampling moment. Since a significant change in load demand will lead to a large difference in the real-time load demand change degree, The larger the value, the smaller the load demand change at the x+1 sampling moment, which means that the load demand is more likely to change from frequent fluctuations to stable small fluctuations. Conversely, it means that the load demand changes from stable small fluctuations to frequent fluctuations. At the same time, combined with the difference between the load demand at the x+1 sampling moment and the historical average load demand at this stage The larger the value, the more likely the corresponding load demand is to change from frequent fluctuations to stable small fluctuations. Conversely, it means that the load demand is changing from stable small fluctuations to frequent fluctuations.

[0144] Figure 6 A schematic diagram of a carrier frequency control system of a pure electric intelligent air conditioner inverter provided by a sixth embodiment of the present invention, the system comprising:

[0145] The load demand module 601 is used to obtain the air flow degree according to the first air pressure data obtained at the air supply outlet of the air conditioner, the second air pressure data obtained at the air return outlet of the air conditioner, and the air flow velocity data in the vehicle, and obtain the load demand degree according to the air flow degree, the temperature data inside and outside the vehicle, and the humidity data inside and outside the vehicle;

[0146] The frequency control module 602 in the initial operation stage of the air conditioner is used to obtain the frequency value of the segmented fixed carrier frequency control mode in the initial operation stage of the air conditioner according to the load value corresponding to the load demand at the first sampling moment, the preset initial frequency value and the load value corresponding to the initial frequency value, and determine whether to switch the air conditioner from the segmented fixed carrier frequency control mode to the adaptive carrier frequency control mode according to the load demand at each moment within the preset time in the initial operation stage of the air conditioner;

[0147] The frequency control module 603 in the stable operation stage of the air conditioner is used to obtain the mode switching factor according to the degree of change of the load demand at a preset sampling moment and the moment before and after it, the average value of the load demand before the sampling moment, and the load demand at the moment after the sampling moment. When the normalized value of the mode switching factor crosses the mode switching threshold, the current frequency control mode of the air conditioner is switched to another frequency control mode.

[0148] The technical features and technical effects of a pure electric intelligent air conditioner inverter carrier frequency control system proposed in an embodiment of the present invention are the same as the method proposed in an embodiment of the present invention, and will not be repeated here.

[0149] The present invention has the following beneficial effects:

[0150] First, the air flow degree is obtained according to the first air pressure data obtained at the air supply outlet of the air conditioner, the second air pressure data obtained at the air return outlet of the air conditioner, and the air flow velocity data in the vehicle, and the load demand degree is obtained according to the air flow degree, the temperature data inside and outside the vehicle, and the humidity data inside and outside the vehicle. The load demand degree is obtained for subsequent determination of different frequency control modes.

[0151] Then, the frequency value of the segmented fixed carrier frequency control mode in the initial operation stage of the air conditioner is obtained according to the load value corresponding to the load demand at the first sampling moment, the preset initial frequency value, and the load value corresponding to the initial frequency value, and whether to switch the air conditioner from the segmented fixed carrier frequency control mode to the adaptive carrier frequency control mode is determined according to the load demand at each moment within the preset time in the initial operation stage of the air conditioner. The segmented fixed carrier frequency control mode is used as the default in the initial operation stage of the air conditioner, and whether the frequency control mode needs to be switched is determined according to the load demand within the preset time in the initial operation stage of the air conditioner.

[0152] Finally, in the stable operation stage of the air conditioner, the mode switching factor is obtained according to the load demand change degree at the preset sampling moment and the moment before and after, the average value of the load demand degree before the sampling moment, and the load demand degree at the moment after the sampling moment. When the normalized value of the mode switching factor crosses the mode switching threshold, the current frequency control mode of the air conditioner is switched to another frequency control mode. This step is used to determine whether to switch the frequency control mode.

[0153] By adopting the present invention, different frequency control modes can be adaptively determined according to the load demand changes of the external environment during the operation of the air conditioner, and the power consumption can be reduced as much as possible while ensuring the efficient operation of the air conditioner.

[0154] It should be noted that the sequence of the above embodiments of the present invention is only for description and does not represent the advantages and disadvantages of the embodiments. The processes depicted in the accompanying drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0155] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

Claims

1. A pure electric intelligent air conditioner inverter carrier frequency control method, characterized in that: The method comprises: The air flow degree is obtained according to the first air pressure data obtained at the air supply outlet of the air conditioner, the second air pressure data obtained at the air return outlet of the air conditioner, and the air flow velocity data inside the vehicle, and the load demand degree is obtained according to the air flow degree, the temperature data inside and outside the vehicle, and the humidity data inside and outside the vehicle; Obtaining the frequency value of the segmented fixed carrier frequency control mode in the initial operation stage of the air conditioner according to the load value corresponding to the load demand at the first sampling moment, the preset initial frequency value, and the load value corresponding to the initial frequency value, and determining whether to switch the air conditioner from the segmented fixed carrier frequency control mode to the adaptive carrier frequency control mode according to the load demand at each moment within the preset time in the initial operation stage of the air conditioner; In the stable operation stage of the air conditioner, the mode switching factor is obtained according to the load demand change degree at the preset sampling moment and the moment before and after the sampling moment, the average value of the load demand before the sampling moment, and the load demand at the moment after the sampling moment. When the normalized value of the mode switching factor crosses the mode switching threshold, the current frequency control mode of the air conditioner is switched to another frequency control mode; The process of obtaining the load demand variation degree includes: Obtaining the absolute value of the load demand at the i+1th moment minus the load demand at the ith moment, and calculating the sum of the absolute values, wherein the value of i ranges from 1 to n-1, and n represents the nth sampling moment; The load demand change degree is obtained by dividing the average value of the load demand before the nth sampling moment by the load demand at the first sampling moment and multiplying the average value by the sum of the absolute values.

2. The pure electric intelligent air conditioner inverter carrier frequency control method according to claim 1, characterized in that: The step of judging whether to switch the air conditioner from the segmented fixed carrier frequency control mode to the adaptive carrier frequency control mode according to the load demand at each moment within a preset time in the initial operation stage of the air conditioner comprises: Within a preset time of the initial operation stage of the air conditioner, the degree of change of the load demand is obtained according to the load demand degree at each moment before the nth sampling moment; when the degree of change of the load demand is greater than a preset conversion threshold, the air conditioner switches from the segmented fixed carrier frequency control mode to the adaptive carrier frequency control mode, wherein n is a positive integer greater than or equal to 2.

3. The pure electric intelligent air conditioner inverter carrier frequency control method according to claim 1, characterized in that: The process of obtaining the air flow degree includes: Subtracting the second air pressure data from the first air pressure data and dividing the resultant value by the second air pressure data to obtain a first ratio; The air flow degree is obtained by multiplying the inverse of the absolute value of the first ratio by the in-vehicle air flow velocity data.

4. The pure electric intelligent air conditioner inverter carrier frequency control method according to claim 1, characterized in that: The process of obtaining the load demand degree includes: The absolute value of the difference between the temperature data inside the vehicle and the temperature data outside the vehicle is recorded as the temperature difference value, and the absolute value of the difference between the humidity data inside the vehicle and the humidity data outside the vehicle is recorded as the humidity difference value; The temperature difference value is multiplied by the humidity difference value to obtain the temperature and humidity difference value inside and outside the vehicle; The load demand is obtained by dividing the difference between the temperature and humidity inside and outside the vehicle by the air flow degree.

5. The pure electric intelligent air conditioner inverter carrier frequency control method according to claim 1, characterized in that: The process of obtaining the frequency value of the segmented fixed carrier frequency control mode in the initial operation stage of the air conditioner includes: The load value corresponding to the load demand at the first sampling moment is multiplied by the initial frequency value and then divided by the load value corresponding to the initial frequency value to obtain the frequency value of the segmented fixed carrier frequency control mode in the initial operation stage of the air conditioner.

6. The pure electric intelligent air conditioner inverter carrier frequency control method according to claim 1, characterized in that: The process of obtaining the mode switching factor includes: Recording the absolute value of the load demand change degree at the sampling moment minus the load demand change degree at a moment before the sampling moment as a first absolute value; The absolute value of the load demand change degree at the sampling moment minus the load demand change degree at a moment after the sampling moment is recorded as a second absolute value; Dividing the average value of the load demand before the sampling moment by the load demand at a moment after the sampling moment to obtain a first ratio; The first absolute value is divided by the second absolute value and then multiplied by the first ratio to obtain the mode switching factor at the sampling moment.

7. The pure electric intelligent air conditioner inverter carrier frequency control method according to claim 1, characterized in that: The method further comprises: When the other frequency control mode is the segmented fixed carrier frequency control mode, the frequency value at a moment before the sampling moment is multiplied by the mode switching factor at a moment after the sampling moment, and then divided by the mode switching threshold to obtain the frequency value of the segmented fixed carrier frequency control mode.

8. The pure electric intelligent air conditioner inverter carrier frequency control method according to claim 1, characterized in that: The method further comprises: When the other frequency control mode is the adaptive carrier frequency control mode, the frequency value at the moment before the sampling moment is multiplied by the load demand at the sampling moment, and then divided by the load demand at the moment before the sampling moment as the frequency value of the adaptive carrier frequency control mode.

9. A pure electric intelligent air conditioner inverter carrier frequency control system, characterized in that: The system comprises: A load demand module, used to obtain the air flow degree according to the first air pressure data obtained at the air supply outlet of the air conditioner, the second air pressure data obtained at the air return outlet of the air conditioner, and the air flow velocity data in the vehicle, and to obtain the load demand degree according to the air flow degree, the temperature data inside and outside the vehicle, and the humidity data inside and outside the vehicle; The frequency control module of the initial operation stage of the air conditioner is used to obtain the frequency value of the segmented fixed carrier frequency control mode of the initial operation stage of the air conditioner according to the load value corresponding to the load demand at the first sampling moment, the preset initial frequency value and the load value corresponding to the initial frequency value, and determine whether to switch the air conditioner from the segmented fixed carrier frequency control mode to the adaptive carrier frequency control mode according to the load demand at each moment within the preset time of the initial operation stage of the air conditioner; The frequency control module in the stable operation stage of the air conditioner is used to obtain a mode switching factor according to the load demand change degree at a preset sampling moment and the moment before and after the sampling moment, the average value of the load demand degree before the sampling moment, and the load demand degree at the moment after the sampling moment. When the normalized value of the mode switching factor crosses the mode switching threshold, the current frequency control mode of the air conditioner is switched to another frequency control mode; The process of obtaining the load demand variation degree includes: Obtaining the absolute value of the load demand at the i+1th moment minus the load demand at the ith moment, and calculating the sum of the absolute values, wherein the value of i ranges from 1 to n-1, and n represents the nth sampling moment; The load demand change degree is obtained by dividing the average value of the load demand before the nth sampling moment by the load demand at the first sampling moment and multiplying the average value by the sum of the absolute values.

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