Method and device for controlling piezoelectric fan, electronic device and storage medium

Abstract

This application discloses a control method, control device, electronic device, and computer-readable storage medium for a piezoelectric fan, relating to the field of fan control technology. The piezoelectric fan is connected to a device to be cooled. The control method includes: determining the operating level of the piezoelectric fan based on the hot spot temperature of the power device and the casing temperature of the device to be cooled; the operating level includes an off level, a low-power optimal operating level, and a full-power level; and when the operating level of the piezoelectric fan is the low-power optimal operating level, adjusting the driving voltage and operating frequency of the piezoelectric fan according to a multi-objective function until the parameters of the multi-objective function are reduced to a minimum value, the parameters of the multi-objective function including the fan power consumption and fan noise of the piezoelectric fan. This application ensures that the piezoelectric fan maintains low power consumption and low noise operation while ensuring safe heat dissipation.

Description

Technical Field

[0001] This application relates to the field of fan control technology, and more specifically, to a control method for a piezoelectric fan, a control device for a piezoelectric fan, an electronic device, and a computer-readable storage medium. Background Technology

[0002] As portable energy storage, electric vehicles, inverters, and other devices become increasingly miniaturized, traditional electric motor fans, with their large size and high energy consumption, are struggling to meet the demands of increasingly compact spaces. Small-sized, low-power piezoelectric fans have thus become ideal heat dissipation devices. The heat dissipation capacity of a piezoelectric fan is affected by parameters such as its vibration amplitude and frequency. Adjusting these parameters to ensure safe heat dissipation while simultaneously achieving low power consumption and low noise is a pressing issue that needs to be addressed. Summary of the Invention

[0003] This application provides a control method, control device, electronic device, and computer-readable storage medium for a piezoelectric fan, which can ensure that the piezoelectric fan can maintain low power consumption and low noise operation while ensuring safe heat dissipation.

[0004] The present application discloses a control method for a piezoelectric fan, wherein the piezoelectric fan is connected to a device to be cooled. The control method includes: determining the operating level of the piezoelectric fan based on the hot spot temperature of the power device and the shell temperature of the device to be cooled, wherein the operating level includes an off level, a low-power optimal operating level, and a full-power level; and when the operating level of the piezoelectric fan is the low-power optimal operating level, adjusting the driving voltage and operating frequency of the piezoelectric fan according to a multi-objective function until the parameters of the multi-objective function are reduced to a minimum value, wherein the parameters of the multi-objective function include the fan power consumption and the fan noise of the piezoelectric fan.

[0005] In some embodiments, determining the operating level of the piezoelectric fan based on the hot spot temperature of the power device and the casing temperature of the device to be cooled includes: determining the operating level of the piezoelectric fan as the off level when the hot spot temperature of the power device is less than or equal to a first device temperature threshold and the casing temperature is less than or equal to a first casing temperature threshold; determining the operating level of the piezoelectric fan as the low-power optimal operating level when the hot spot temperature of the power device is greater than the first device temperature threshold and the casing temperature is less than a second casing temperature threshold, wherein the first casing temperature threshold is less than the second casing temperature threshold; and determining the operating level of the piezoelectric fan as the full-power level when the hot spot temperature of the power device is greater than or equal to the second device temperature threshold and the casing temperature is greater than or equal to the second casing temperature threshold, wherein the first device temperature threshold is less than the second device temperature threshold.

[0006] In some embodiments, the multi-objective function includes an initial function to be adjusted and an adjusted objective function. The step of adjusting the drive voltage and operating frequency of the piezoelectric fan according to the multi-objective function until the parameters of the multi-objective function are reduced to a minimum value includes: obtaining the initial function, which includes a power consumption weight of the fan's power consumption and a noise weight of the fan's noise; adjusting the power consumption weight and the noise weight according to the surrounding environment of the piezoelectric fan to obtain the objective function; and adjusting the drive voltage and operating frequency of the piezoelectric fan according to the objective function until the parameters of the objective function are reduced to a minimum value.

[0007] In some embodiments, adjusting the drive voltage and operating frequency of the piezoelectric fan according to the objective function until the parameters of the objective function are reduced to a minimum value includes: obtaining the maximum value of the drive voltage, the lower limit coefficient of the heat dissipation capacity of the piezoelectric fan, and the number of blades of the piezoelectric fan; obtaining the minimum value of the drive voltage according to the lower limit coefficient of the heat dissipation capacity and the number of blades; determining the value range of the drive voltage according to the minimum value and the maximum value of the drive voltage; obtaining multiple preset initial frequencies and obtaining multiple preset initial voltages according to the value range of the drive voltage; and calculating the objective function according to the preset initial frequencies and the preset initial voltages, and determining the preset initial frequency and the preset initial voltage corresponding to the minimum value of the objective function as the operating frequency and the drive voltage, respectively.

[0008] In some embodiments, obtaining the lower limit coefficient of the heat dissipation capacity of the piezoelectric fan includes: obtaining the heat generation of the piezoelectric fan based on the power loss ratio and the inverter output power; and determining the lower limit coefficient of heat dissipation capacity based on the heat generation, the heat exchange surface area of ​​the piezoelectric fan, the hot spot temperature of the power device, and the ambient temperature.

[0009] In some implementations, obtaining multiple preset initial frequencies and obtaining multiple preset initial voltages according to the value range of the driving voltage includes: obtaining multiple preset initial frequencies according to a preset frequency step size, and obtaining multiple preset initial voltages according to a preset voltage step size and the value range of the driving voltage.

[0010] In some embodiments, the step of calculating the objective function based on the preset initial frequency and the preset initial voltage, and determining the preset initial frequency and the preset initial voltage corresponding to the minimum value of the objective function as the operating frequency and the driving voltage, respectively, includes: obtaining the load equivalent capacitance of the piezoelectric fan; obtaining the initial power consumption based on the load equivalent capacitance, the preset initial frequency, and the preset initial voltage; obtaining the initial noise based on the number of blades, the preset initial frequency, and the preset initial voltage; and obtaining the objective function based on the initial power consumption and the initial noise, and determining the preset initial frequency and the preset initial voltage corresponding to the minimum value of the objective function as the operating frequency and the driving voltage, respectively.

[0011] In some embodiments, the control method further includes: controlling the piezoelectric fan to shut down when the piezoelectric fan is in the off position; and controlling the drive voltage and the operating frequency to increase to their maximum values ​​when the piezoelectric fan is in the full power position.

[0012] This application provides a control device for a piezoelectric fan. The piezoelectric fan is connected to a device to be cooled. The control device includes a determining module and an adjusting module. The determining module is used to determine the operating level of the piezoelectric fan based on the hot spot temperature of the power device and the casing temperature of the device to be cooled. The operating levels include an off level, a low-power optimal operating level, and a full-power level. The adjusting module is used to adjust the driving voltage and operating frequency of the piezoelectric fan according to a multi-objective function when the operating level of the piezoelectric fan is the low-power optimal operating level, until the parameters of the multi-objective function are reduced to a minimum value. The parameters of the multi-objective function include the fan power consumption and fan noise of the piezoelectric fan.

[0013] This application also provides an electronic device, which includes the control device for the piezoelectric fan described in any of the above embodiments.

[0014] This application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the control method described in any of the above embodiments.

[0015] In the piezoelectric fan control method, control device, electronic device, and computer-readable storage medium provided in this application, the piezoelectric fan is connected to the device to be cooled, and the piezoelectric fan can dissipate heat for the device when it needs to dissipate heat. This method determines the operating position of the piezoelectric fan—whether it is in the off position, the optimal low-power operating position, or the full-power position—based on the hot spot temperature of the power devices and the casing temperature of the device to be cooled, ensuring that the temperature of the internal power devices and the casing of the device to be cooled does not become excessively high. While ensuring that the internal power device temperature and the casing temperature of the device to be cooled meet the conditions for normal operation, the method adjusts the drive voltage and operating frequency of the piezoelectric fan to minimize the fan power consumption and fan noise parameters in the multi-objective function, thereby ensuring that the piezoelectric fan can maintain low power consumption and low noise operation while ensuring safe heat dissipation.

[0016] Additional aspects and advantages of embodiments of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of embodiments of this application. Attached Figure Description

[0017] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, wherein:

[0018] Figure 1 This is a flowchart illustrating the control method of a piezoelectric fan according to some embodiments of this application;

[0019] Figure 2 This is a schematic diagram of the control device for a piezoelectric fan according to some embodiments of this application;

[0020] Figure 3 These are example diagrams of a piezoelectric fan and a device to be cooled according to some embodiments of this application;

[0021] Figure 4 This is a flowchart illustrating the process of determining the operating level of a piezoelectric fan based on the hot spot temperature of the power device of the device to be cooled and the shell temperature of the device to be cooled in some embodiments of this application.

[0022] Figure 5This is a flowchart illustrating the process of adjusting the drive voltage and operating frequency of a piezoelectric fan according to a multi-objective function in the control method of a piezoelectric fan according to some embodiments of this application, until the parameters of the multi-objective function are reduced to the minimum value.

[0023] Figure 6 This is a flowchart illustrating the process of adjusting the drive voltage and operating frequency of a piezoelectric fan according to an objective function in a control method for a piezoelectric fan according to some embodiments of this application, until the parameters of the objective function are reduced to the minimum value.

[0024] Figure 7 This is a flowchart illustrating the process of obtaining the maximum value of the driving voltage, the lower limit coefficient of the heat dissipation capacity of the piezoelectric fan, and the number of blades of the piezoelectric fan in the control method of some embodiments of this application.

[0025] Figure 8 This is a schematic diagram of the process of obtaining multiple preset initial frequencies and obtaining multiple preset initial voltages according to the value range of the driving voltage in the control method of a piezoelectric fan of some embodiments of this application.

[0026] Figure 9 This is a flowchart illustrating the control method of a piezoelectric fan according to some embodiments of this application, in which an objective function is calculated based on a preset initial frequency and a preset initial voltage, and the preset initial frequency and preset initial voltage corresponding to the minimum value of the objective function are determined as the operating frequency and driving voltage, respectively.

[0027] Figure 10 This is a flowchart illustrating the control method of a piezoelectric fan according to other embodiments of this application;

[0028] Figure 11 This is a schematic diagram of the structure of an electronic device according to some embodiments of this application;

[0029] Figure 12 This is a schematic diagram illustrating the connection state of a computer-readable storage medium and a processor according to certain embodiments of this application.

[0030] Explanation of key component symbols:

[0031] Electronic device 100;

[0032] Control device 10 for piezoelectric blower;

[0033] Determine module 11; Adjust module 12;

[0034] Processor 20;

[0035] 200; computer-readable storage medium; 202; computer program;

[0036] Energy storage inverter 30;

[0037] Thermally conductive and insulating material 40;

[0038] Power radiator 50;

[0039] Air duct plate 60;

[0040] Piezoelectric fan 70. Detailed Implementation

[0041] The embodiments of this application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the embodiments of this application, and should not be construed as limiting the embodiments of this application.

[0042] As portable energy storage devices, electric vehicle controllers, and high-density inverters continue to evolve towards miniaturization and high integration, the limitations of traditional motor-driven cooling fans are becoming increasingly apparent. The large size of traditional motor-driven cooling fans, with their built-in motors and drive units, not only occupies already limited internal space but also contradicts the current mainstream trend of energy conservation and emission reduction in equipment. Therefore, piezoelectric fans, with their slim and lightweight characteristics, low power consumption, and lack of magnetic interference, have become the preferred component for cooling these space-compact power electronic devices. However, the core cooling mechanism of piezoelectric fans originates from the high-frequency reciprocating oscillations of their metal or ceramic blades under the influence of a driving electric field. The periodic pushing and suction action of the blades forms an effective flow layer on the surface, enhancing local heat exchange capacity. The cooling performance of a piezoelectric fan depends on whether the oscillation amplitude can establish a sufficiently wide displacement stroke at the blade tip and whether a sufficient number of oscillations are completed per unit time. Therefore, parameters such as the vibration amplitude and frequency of a piezoelectric fan affect its heat dissipation effect. How to adjust these parameters to achieve effective heat dissipation while also maintaining low power consumption and low noise is a pressing problem. To address this issue, this application provides a control method for a piezoelectric fan (e.g., Figure 1 As shown), the control device for the piezoelectric fan (such as...) Figure 2 As shown), electronic devices (such as...) Figure 11 (as shown) and computer-readable storage media (such as Figure 12 (As shown).

[0043] Please see Figures 1 to 3 The control method for a piezoelectric fan according to embodiments of this application, wherein the piezoelectric fan is connected to the device to be cooled, includes:

[0044] 03: Based on the hot spot temperature of the power devices in the device to be cooled and the casing temperature of the device, determine the operating level of the piezoelectric fan. The operating levels include the off level, the optimal low-power operating level, and the full-power level;

[0045] 05: When the piezoelectric fan is in the low-power optimal operating mode, adjust the drive voltage and operating frequency of the piezoelectric fan according to the multi-objective function until the parameters of the multi-objective function are reduced to the minimum value. The parameters of the multi-objective function include the fan power consumption and fan noise of the piezoelectric fan.

[0046] The above-described control method for a piezoelectric fan can be applied to a control device 10 for a piezoelectric fan. The control device 10 for the piezoelectric fan in this embodiment includes a determining module 11 and an adjusting module 12. The determining module 11 determines the operating level of the piezoelectric fan based on the hot spot temperature of the power device in the device to be cooled and the casing temperature of the device. The operating levels include a shut-off level, a low-power optimal operating level, and a full-power level. The adjusting module 12, when the piezoelectric fan is operating at the low-power optimal operating level, adjusts the drive voltage and operating frequency of the piezoelectric fan according to a multi-objective function until the parameters of the multi-objective function are reduced to their minimum values. The parameters of the multi-objective function include the fan power consumption and fan noise of the piezoelectric fan.

[0047] Specifically, the piezoelectric fan control device 10 is the core device for controlling the piezoelectric fan to achieve its heat dissipation function. The piezoelectric fan control device 10 is a physical device integrating hardware and software logic. The piezoelectric fan control device 10 can be installed on the internal control module, control device, or controller of the piezoelectric fan, or it can be installed on other devices used for remote control of the piezoelectric fan's operation. Through temperature sensing, speed selection, and operating parameter optimization, the piezoelectric fan control device 10 achieves effective heat dissipation in various scenarios, while also ensuring low power consumption and low noise operation. The specific functions of the piezoelectric fan control device 10 include temperature monitoring, speed switching, drive parameter adjustment, and multi-objective optimization algorithms, which will be explained in detail below.

[0048] More specifically, the control device 10 of the piezoelectric fan includes a determining module 11 and an adjusting module 12. The determining module 11 is one of the core functional units of the control device 10, and it is a logic module that determines the operating state of the piezoelectric fan based on data obtained from real-time monitoring of the hot spot temperature of the power device and the temperature of the device casing. The adjusting module 12 is also one of the core functional units of the control device 10, and it is an execution module that optimizes various operating parameters (such as drive voltage and operating frequency) of the piezoelectric fan under the optimal low-power operating mode.

[0049] Furthermore, the piezoelectric fan is connected to the device that needs cooling. There are no special requirements regarding the type of device; any device that generates heat during operation can be used. Please refer to [link / reference]. Figure 3 ,exist Figure 3 In this design, the device to be cooled is the energy storage inverter 30, which is the source of heat and needs to be cooled. At least one side of the energy storage inverter 30 is provided with a thermally conductive insulating material 40. This material 40 fills the tiny gaps between the power device (such as the energy storage inverter 30) and the power heat sink 50, reducing contact thermal resistance and efficiently transferring heat from the power device (such as the energy storage inverter 30) to the power heat sink 50. The thermally conductive insulating material 40 can be any sheet of thermally conductive insulating material with a certain thickness and flexibility, or it can be silicone grease or phase change material applied to the power device (such as the energy storage inverter 30). The power heat sink 50 receives the heat transferred through the thermally conductive insulating material 40 and, through its large surface area provided by numerous fins or tapers, dissipates the heat to the surrounding air via conduction and convection. The air duct plate 60 forms a channel (air duct) around the fin area of ​​the power radiator 50, thereby forcing the airflow (driven by the piezoelectric fan 70) to concentrate and flow through the narrow gaps between the fins of the power radiator 50, maximizing the contact area between the airflow and the heat dissipation fins, and improving heat exchange efficiency. The piezoelectric fan 70 is used to generate directional airflow (usually along the direction of the air duct), forcing air to flow through the fins of the power radiator 50 within the air duct at a certain speed and flow rate.

[0050] Furthermore, the core component of a piezoelectric fan is a piezoelectric element (such as a piezoelectric ceramic). When an alternating voltage is applied to the piezoelectric fan, the piezoelectric element deforms (bends upward or downward) due to the inverse piezoelectric effect. This deformation causes the connected metal or plastic blades to vibrate, thereby driving the surrounding airflow and carrying away heat to achieve the heat dissipation function.

[0051] Furthermore, in step 03, the hot spot temperature of the power device in the device to be cooled refers to the temperature of the area where the power conversion components (such as MOSFETs and insulated-gate bipolar transistors) inside the device operate at their highest temperature. Therefore, the hot spot temperature of the power device directly reflects the thermal load status of the core heat-generating components of the device and is a key indicator for triggering the start / stop and speed switching of the piezoelectric fan. The outer casing temperature of the device to be cooled refers to the temperature of its outer surface. The outer casing temperature reflects the overall heat dissipation status of the device. The outer casing temperature and the hot spot temperature of the internal power device together constitute the temperature criterion for fan speed switching, avoiding mis-adjustment of the speed due to local temperature measurement errors. The operating speeds of the piezoelectric fan include the off speed, the low-power optimal operating speed, and the full-power speed. The relevant information about these speeds will be further explained below.

[0052] Furthermore, in step 05, the multi-objective function can be a mathematical model containing parameters, each with a corresponding weight coefficient. In this application, the parameters of the multi-objective function include the power consumption and noise of the piezoelectric fan. The power consumption and noise are related to the driving voltage and operating frequency of the piezoelectric fan. Relevant personnel can adjust the weight coefficients corresponding to the power consumption and the noise to meet different scenario requirements.

[0053] Furthermore, the driving voltage is the voltage applied to the piezoelectric element (such as a piezoelectric ceramic plate) of the piezoelectric fan. The higher the driving voltage, the greater the deformation of the piezoelectric element, the larger the amplitude, and the greater the airflow. The operating frequency refers to the frequency of the driving voltage, which is directly proportional to the deformation frequency of the piezoelectric element.

[0054] Understandably, this application provides a control method for a piezoelectric fan. The piezoelectric fan is connected to the device to be cooled, and it provides cooling to the device when needed. This method determines the operating position of the piezoelectric fan—whether it is in the off position, the optimal low-power operating position, or the full-power position—based on the hot spot temperature of the power devices and the casing temperature of the device. This ensures that the temperatures of the internal power devices and the casing of the device do not become excessively high. While ensuring that the internal power device temperatures and casing temperatures meet the conditions for normal operation, the method adjusts the drive voltage and operating frequency of the piezoelectric fan to minimize the fan power consumption and fan noise parameters in the multi-objective function. This ensures that the piezoelectric fan maintains low power consumption and low noise operation while ensuring safe heat dissipation.

[0055] In some implementations, please refer to Figure 4 03: Determine the operating speed of the piezoelectric fan based on the hot spot temperature of the power devices in the device to be cooled and the casing temperature of the device, including:

[0056] 031: When the hot spot temperature of the power device is less than or equal to the first device temperature threshold and the casing temperature is less than or equal to the first casing temperature threshold, the operating position of the piezoelectric fan is determined to be the off position;

[0057] 032: When the hot spot temperature of the power device is greater than the first device temperature threshold and the casing temperature is less than the second casing temperature threshold, the operating mode of the piezoelectric fan is determined to be the optimal low-power operating mode, where the first casing temperature threshold is less than the second casing temperature threshold; and

[0058] 033: When the hot spot temperature of the power device is greater than or equal to the second device temperature threshold and the casing temperature is greater than or equal to the second casing temperature threshold, the operating mode of the piezoelectric fan is determined to be the full power mode, and the first device temperature threshold is less than the second device temperature threshold.

[0059] The above-described control method for the piezoelectric fan can be applied to the control device 10 of the piezoelectric fan. The determination module 11 in this embodiment is further configured to determine the operating mode of the piezoelectric fan as the off mode when the hot spot temperature of the power device is less than or equal to the first device temperature threshold and the casing temperature is less than or equal to the first casing temperature threshold; to determine the operating mode of the piezoelectric fan as the low-power optimal operating mode when the hot spot temperature of the power device is greater than the first device temperature threshold and the casing temperature is less than the second casing temperature threshold, wherein the first casing temperature threshold is less than the second casing temperature threshold; and to determine the operating mode of the piezoelectric fan as the full-power mode when the hot spot temperature of the power device is greater than or equal to the second device temperature threshold and the casing temperature is greater than or equal to the second casing temperature threshold, wherein the first device temperature threshold is less than the second device temperature threshold.

[0060] Specifically, if the hot spot temperature of the power device is less than or equal to the first device temperature threshold (which can be set by relevant personnel according to the actual situation) and the casing temperature is less than or equal to the first casing temperature threshold (which can be set by relevant personnel according to the actual situation), it indicates that the temperature of the device to be cooled has not risen to the point where the piezoelectric fan is needed for heat dissipation. At this time, the device to be cooled may have just been started or has not yet been started. Therefore, the piezoelectric fan is set to the off position at this time.

[0061] Specifically, if the hot spot temperature of the power device is greater than the first device temperature threshold (which can be set by relevant personnel according to the actual situation) and the casing temperature is less than the second casing temperature threshold (which can be set by relevant personnel according to the actual situation, with the first casing temperature threshold being less than the second casing temperature threshold), it indicates that the temperature of the device to be cooled has risen to the point where a piezoelectric fan is needed for heat dissipation. At this time, the device to be cooled may have been running for a period of time. Therefore, the piezoelectric fan is determined to be in the optimal low-power operation mode at this time.

[0062] Specifically, if the hot spot temperature of the power device is greater than or equal to the second device temperature threshold (which can be set by relevant personnel according to the actual situation, and the first device temperature threshold is less than the second device temperature threshold) and the casing temperature is greater than or equal to the second casing temperature threshold (which can be set by relevant personnel according to the actual situation, and the first casing temperature threshold is less than the second casing temperature threshold), it indicates that the temperature of the device to be cooled has risen to a high level and needs to be reduced as soon as possible. At this time, the device to be cooled may have been running for a long time. Therefore, the piezoelectric fan is set to full power to reduce the temperature of the device to be cooled as soon as possible.

[0063] Please combine Figure 5 In some implementations, the multi-objective function includes an initial function to be adjusted and an adjusted objective function. 05: Based on the multi-objective function, adjust the drive voltage and operating frequency of the piezoelectric fan until the parameters of the multi-objective function are reduced to their minimum values, including:

[0064] 051: Obtain the initial function, which includes the power consumption weight of the wind turbine and the noise weight of the wind turbine;

[0065] 053: Based on the surrounding environment of the piezoelectric fan, adjust the power consumption weight and noise weight to obtain the objective function; and

[0066] 055: Based on the objective function, adjust the drive voltage and operating frequency of the piezoelectric fan until the parameters of the objective function are reduced to their minimum values.

[0067] The above-described control method for a piezoelectric fan can be applied to the control device 10 of the piezoelectric fan. The adjustment module 12 in this embodiment is further used to: obtain an initial function, which includes a power consumption weight and a noise weight of the fan; adjust the power consumption weight and noise weight according to the surrounding environment of the piezoelectric fan to obtain a target function; and adjust the driving voltage and operating frequency of the piezoelectric fan according to the target function until the parameters of the target function are reduced to the minimum value.

[0068] Specifically, the initial function includes power consumption weights for wind turbine power consumption and noise weights for wind turbine noise. The initial function can be a weighted multi-objective optimization model: J = w1•P fan (Wind turbine power consumption) +w2•L noise (Fan noise), where w1 is the weighting coefficient corresponding to fan power consumption and w2 is the weighting coefficient corresponding to fan noise.

[0069] Furthermore, relevant personnel can adjust the power consumption weight and noise weight based on the surrounding environment of the piezoelectric fan to obtain the objective function. For example, if the current scenario is nighttime, the focus can be on reducing noise, increasing the weight coefficient corresponding to fan noise (i.e., increasing w2 and decreasing w1). Similarly, if the current scenario is nighttime, the focus can be on reducing fan power consumption, increasing the weight coefficient corresponding to fan power consumption (i.e., increasing w1 and decreasing w2).

[0070] Furthermore, after adjusting the power consumption and noise weights according to the surrounding environment to obtain the objective function, the drive voltage and operating frequency of the piezoelectric fan can be adjusted according to the objective function until the parameters of the objective function are reduced to their minimum values. This process will be explained in detail below.

[0071] Please see Figure 6In some implementations, 055: Adjusting the drive voltage and operating frequency of the piezoelectric fan according to the objective function until the parameters of the objective function are reduced to their minimum values, including:

[0072] 0551: Obtain the maximum value of the driving voltage, the lower limit coefficient of the heat dissipation capacity of the piezoelectric fan, and the number of blades of the piezoelectric fan;

[0073] 0552: Based on the lower limit coefficient of heat dissipation capacity and the number of blades, the minimum value of the driving voltage is obtained;

[0074] 0553: Determine the range of values ​​for the driving voltage based on the minimum and maximum values ​​of the driving voltage;

[0075] 0554: Obtain multiple preset initial frequencies, and obtain multiple preset initial voltages based on the range of driving voltage values; and

[0076] 0555: Calculate the objective function based on the preset initial frequency and preset initial voltage, and determine the preset initial frequency and preset initial voltage corresponding to the minimum value of the objective function as the operating frequency and driving voltage, respectively.

[0077] The above-described control method for a piezoelectric fan can be applied to the control device 10 of the piezoelectric fan. The adjustment module 12 in this embodiment is further configured to: obtain the maximum value of the driving voltage, the lower limit coefficient of the heat dissipation capacity of the piezoelectric fan, and the number of blades of the piezoelectric fan; obtain the minimum value of the driving voltage based on the lower limit coefficient of the heat dissipation capacity and the number of blades; determine the range of driving voltage values ​​based on the minimum and maximum values ​​of the driving voltage; obtain multiple preset initial frequencies and obtain multiple preset initial voltages based on the range of driving voltage values; calculate an objective function based on the preset initial frequencies and preset initial voltages, and determine the preset initial frequency and preset initial voltage corresponding to the minimum value of the objective function as the operating frequency and driving voltage, respectively.

[0078] Specifically, based on the lower limit coefficient of heat dissipation capacity and the number of blades, the minimum value of the driving voltage can be obtained, while the maximum value of the driving voltage is the calibration parameter of the piezoelectric fan itself. Therefore, after obtaining the minimum and maximum values ​​of the driving voltage, the range of driving voltage values ​​can be obtained. The operating frequency also has an upper limit (which is also a calibration parameter of the piezoelectric fan). The adjustment module 12 selects multiple initial frequencies and multiple initial voltages within the range according to a certain rule, and substitutes them into the objective function for calculation. Then, the adjustment module 12 determines the initial frequency and initial voltage corresponding to the minimum value of the objective function as the operating frequency and driving voltage of the piezoelectric fan.

[0079] Furthermore, since the objective function is J = w1•P fan (Wind turbine power consumption) +w2•L noise(Wind turbine noise), therefore, by substituting multiple initial frequencies and multiple initial voltages into the objective function in groups, different values ​​of the objective function can be obtained. The formula for wind turbine power consumption is as follows:

[0080] ;

[0081] Among them, P fan This refers to the power consumption of the wind turbine, C load This refers to the equivalent capacitance of a piezoelectric fan, V. drv "f" refers to the driving voltage, and "f" refers to the operating frequency. This formula is essentially derived from the AC power consumption calculation of capacitive loads. The driving voltage supplied to the piezoelectric fan is a high-frequency AC voltage applied to the piezoelectric ceramic plate; therefore, the piezoelectric fan is essentially a pure capacitive load. In a pure capacitive load, there is no resistive dissipation; the energy depends entirely on the establishment and release of the electric field. It charges and discharges once per cycle, consuming energy of 1 / 2 * C (capacitance) * V. 2 (The square of the driving voltage) occurs f (operating frequency) times per second, so the power consumption is the energy multiplied by the operating frequency.

[0082] Furthermore, the noise level of the fan is disclosed as follows:

[0083] ;

[0084] Among them, L noise For fan noise, α and β are fitting coefficients, which can be determined through prototype testing or based on the experience of relevant personnel. blades N represents the number of blades in a piezoelectric fan. blades •V drv • f represents the intensity factor of the noise source (such as the product of flow rate, air volume, power, etc.). The product of these three parameters represents the equivalent vibration intensity factor of the fan (the higher the value, the greater the air volume, and the more noticeable the noise). The logarithmic function conforms to the human ear's perception of noise (human ear perception is logarithmic). α determines the sensitivity to noise growth (for example, when α=20, it is equivalent to a 10-fold change in sound pressure, resulting in a 20dB increase in noise). β determines the minimum noise baseline value (floor noise, i.e., background noise) when there is no air volume.

[0085] Furthermore, for example, assuming that the power consumption weight and noise weight are determined to be 0.7 and 0.3 respectively based on the surrounding environment, the following table can be obtained based on the calibration parameters of the piezoelectric fan (such as the maximum driving voltage, number of blades, maximum operating frequency, etc.):

[0086] Table 1 Example of Parameters

[0087]

[0088] As shown in Table 1 above, assuming an operating frequency f = 100 Hz, the corresponding lower limit of the driving voltage can be calculated as V. drv,min =K / N blades • f = 200 / (5 × 100) = 200 / 500 = 0.4 V, upper voltage limit V drv,max =12 V, therefore, the range of the driving voltage is V. drv ∈[0.4 V, 12 V]. An example voltage V is taken from the range of driving voltage values. drv =6V fan power consumption: P fan =1 / 2•0.01•(6) 2 •100=18, Fan noise: L noise =10•log(5•6•100)+30=110.06. At this time, the objective function J=0.7•18+0.3•110.06=45.618.

[0089] Furthermore, change V again drv And f, repeat the above steps multiple times until the minimum value of the objective function is found. For example, let's take: V drv =8 V, f=120 Hz. Calculate the following for V: drv,min =200 / 5•120≈0.33 V, the driving voltage range is 0.33V~12V. At this time, the fan power consumption is 38.4. The fan noise is 114.7. Objective function: J=0.7•38.4+0.3•114.7=61.2. Comparing these two sets of results, it can be seen that the second set of objective function values ​​is higher, indicating that the first set of parameters offers a better trade-off between energy efficiency and noise. The value of the objective function represents the overall cost of fan operation. The smaller the value of the objective function, the better the overall score (balancing low energy consumption and low noise).

[0090] Please see Figure 7 In some implementations, 0551: Obtaining the lower limit coefficient of the heat dissipation capacity of the piezoelectric fan includes:

[0091] 05511: Based on the power loss ratio and the inverter output power, the heat generation of the piezoelectric fan is obtained; and

[0092] 05513: Determine the lower limit coefficient of heat dissipation capacity based on the heat generation, heat exchange surface area of ​​the piezoelectric fan, hot spot temperature of the power device, and ambient temperature.

[0093] The above-mentioned control method for piezoelectric fans can be applied to the control device 10 of the piezoelectric fan. The adjustment module 12 in the embodiment of this application is also used to: obtain the heat generation of the piezoelectric fan based on the power loss ratio and the inverter output power; and determine the lower limit coefficient of heat dissipation capacity based on the heat generation, the heat exchange surface area of ​​the piezoelectric fan, the hot spot temperature of the power device and the ambient temperature.

[0094] Specifically, the formula for calculating the heat generated by the fan is as follows: Q gen =η loss •P out , where η loss ∈[0.03, 0.1], used to reflect the proportion of device losses. Qgen is the heat generation, and Pout is the output power of the inverter. Then, the lower limit coefficient of heat dissipation capacity can be calculated according to the following formula:

[0095] ;

[0096] Where K is the lower limit coefficient of heat dissipation capacity, and A surf T represents the heat exchange surface area of ​​the piezoelectric fan. core T represents the hotspot temperature of the power device. amb Let C be the ambient temperature and C be the specific heat capacity of the surrounding air. The larger C is, the better the heat dissipation. The exponent 1 / n is added because the relationship between air volume and heat exchange capacity is often not perfectly linear. After increasing the air volume, the cooling capacity per unit air volume will gradually decrease. Therefore, a nonlinear factor is introduced to correct the formula.

[0097] Please see Figure 8 In some implementations, 0554: Acquire multiple preset initial frequencies, and acquire multiple preset initial voltages based on the range of driving voltage values, including:

[0098] 05541: Based on the preset frequency step size, obtain multiple preset initial frequencies, and based on the preset voltage step size and the value range of the driving voltage, obtain multiple preset initial voltages.

[0099] The above-mentioned control method for piezoelectric fans can be applied to the control device 10 of the piezoelectric fan. The adjustment module 12 in this embodiment is also used to obtain multiple preset initial frequencies according to a preset frequency step size, and to obtain multiple preset initial voltages according to a preset voltage step size and the value range of the driving voltage.

[0100] Specifically, both the preset frequency step size and the preset voltage step size can be set by the relevant personnel. For example, assuming the preset frequency step size is set to 10Hz and the preset voltage step size is set to 0.1V, the initial frequency is selected from 0 to the maximum operating frequency, taking a value every 10Hz. The initial voltage is selected from the minimum driving voltage, taking a value every 0.1V until the maximum driving voltage. Then, all combinations of initial frequency and initial voltage are enumerated, and the objective function is calculated.

[0101] Please see Figure 9In some implementations, 0555: Calculate an objective function based on a preset initial frequency and a preset initial voltage, and determine the preset initial frequency and preset initial voltage corresponding to the minimum value of the objective function as the operating frequency and driving voltage, respectively, including:

[0102] 05551: Obtain the load equivalent capacitance of the piezoelectric fan, and obtain the initial power consumption based on the load equivalent capacitance, the preset initial frequency, and the preset initial voltage.

[0103] 05553: Based on the number of blades, the preset initial frequency, and the preset initial voltage, the initial noise is obtained; and

[0104] 05555: Based on the initial power consumption and initial noise, the objective function is obtained, and the preset initial frequency and preset initial voltage corresponding to the minimum value of the objective function are determined as the operating frequency and driving voltage, respectively.

[0105] The above-described control method for a piezoelectric fan can be applied to the control device 10 of the piezoelectric fan. The adjustment module 12 in this embodiment is further configured to: obtain the load equivalent capacitance of the piezoelectric fan; obtain the initial power consumption based on the load equivalent capacitance, a preset initial frequency, and a preset initial voltage; obtain the initial noise based on the number of blades, a preset initial frequency, and a preset initial voltage; and obtain an objective function based on the initial power consumption and the initial noise, and determine the preset initial frequency and preset initial voltage corresponding to the minimum value of the objective function as the operating frequency and driving voltage, respectively.

[0106] Specifically, the calculation process for initial power consumption and initial noise has been explained above, and will not be repeated here.

[0107] Please see Figure 10 In some implementations, the control method further includes:

[0108] 04: When the piezoelectric blower is in the off position, control the piezoelectric blower to shut down; and

[0109] 06: When the piezoelectric fan is running at full power, the control drive voltage and operating frequency are both increased to their maximum values.

[0110] The aforementioned control method for the piezoelectric fan can be applied to the control device 10 for the piezoelectric fan. The control device 10 further includes a first control module and a second control module. The first control module is used to control the piezoelectric fan to shut down when the piezoelectric fan is in the off position. The second control module is used to control the drive voltage and operating frequency to be increased to their maximum values ​​when the piezoelectric fan is in the full power position.

[0111] Understandably, when the piezoelectric blower is in the off position, it no longer needs to run, and the first control module controls it to shut down. When the piezoelectric blower is in the full power position, it needs to run at maximum amplitude and maximum operating frequency, and the second control module controls the drive voltage and operating frequency to be increased to their maximum values.

[0112] In summary, in the piezoelectric fan control method provided in this application, the piezoelectric fan is connected to the device to be cooled, and the piezoelectric fan can dissipate heat for the device when it needs to dissipate heat. This method determines the operating position of the piezoelectric fan—whether it is in the off position, the optimal low-power operating position, or the full-power position—by using the hot spot temperature of the power devices and the casing temperature of the device to be cooled, ensuring that the temperature of the internal power devices and the casing of the device to be cooled does not become excessively high. While ensuring that the internal power device temperature and the casing temperature of the device to be cooled meet the conditions for normal operation, the method adjusts the drive voltage and operating frequency of the piezoelectric fan to minimize the fan power consumption and fan noise parameters in the multi-objective function, thereby ensuring that the piezoelectric fan can maintain low power consumption and low noise operation while ensuring safe heat dissipation.

[0113] Please see Figure 11 In some embodiments, this application also provides an electronic device 100, which includes a control device 10 for the piezoelectric fan in any of the above embodiments.

[0114] Please see Figure 12 In some embodiments, this application also provides a computer-readable storage medium 200 having a computer program 202 stored thereon, which, when executed by a processor, implements the method in any of the above embodiments.

[0115] For example, when computer program 202 is executed by processor 20, the following method is implemented:

[0116] 03: Based on the hot spot temperature of the power devices in the device to be cooled and the casing temperature of the device, determine the operating level of the piezoelectric fan. The operating levels include the off level, the optimal low-power operating level, and the full-power level;

[0117] 05: When the piezoelectric fan is in the low-power optimal operating mode, adjust the drive voltage and operating frequency of the piezoelectric fan according to the multi-objective function until the parameters of the multi-objective function are reduced to the minimum value. The parameters of the multi-objective function include the fan power consumption and fan noise of the piezoelectric fan.

[0118] For example, when computer program 202 is executed by processor 20, the following method is implemented:

[0119] 031: When the hot spot temperature of the power device is less than or equal to the first device temperature threshold and the casing temperature is less than or equal to the first casing temperature threshold, the operating position of the piezoelectric fan is determined to be the off position;

[0120] 032: When the hot spot temperature of the power device is greater than the first device temperature threshold and the casing temperature is less than the second casing temperature threshold, the operating mode of the piezoelectric fan is determined to be the optimal low-power operating mode, where the first casing temperature threshold is less than the second casing temperature threshold; and

[0121] 033: When the hot spot temperature of the power device is greater than or equal to the second device temperature threshold and the casing temperature is greater than or equal to the second casing temperature threshold, the operating mode of the piezoelectric fan is determined to be the full power mode, and the first device temperature threshold is less than the second device temperature threshold.

[0122] For example, when computer program 202 is executed by processor 20, it can also implement the methods in 04, 051, 053, 055, 0551, 05511, 05513, 0552, 0553, 0554, 05541, 0555, 05551, 05553, 05555 and 06.

[0123] In the computer-readable storage medium 200 of this application, a piezoelectric fan is connected to the device to be cooled, and the piezoelectric fan can dissipate heat for the device when it needs to be cooled. This method determines the operating position of the piezoelectric fan—whether it is in the off position, the optimal low-power operating position, or the full-power position—by using the hot spot temperature of the power devices and the casing temperature of the device to be cooled, ensuring that the temperature of the internal power devices and the casing of the device to be cooled does not become excessively high. While ensuring that the internal power device temperature and the casing temperature of the device to be cooled meet the conditions for normal operation, the method adjusts the drive voltage and operating frequency of the piezoelectric fan to minimize the fan power consumption and fan noise parameters in the multi-objective function, thereby ensuring that the piezoelectric fan can maintain low power consumption and low noise operation while ensuring safe heat dissipation.

[0124] In the description of this specification, the references to terms such as "some embodiments," "in one example," "exemplarily," etc., indicate that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0125] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing a particular logical function or process, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the function involved, as will be understood by those skilled in the art to which embodiments of this application pertain.

[0126] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A control method for a piezoelectric fan, characterized in that, The piezoelectric fan is connected to the device to be cooled, and the control method includes: Based on the hot spot temperature of the power device in the device to be cooled and the casing temperature of the device to be cooled, the operating level of the piezoelectric fan is determined, including an off level, a low-power optimal operating level, and a full-power level; and When the piezoelectric fan is in the optimal low-power operating mode, the drive voltage and operating frequency of the piezoelectric fan are adjusted according to a multi-objective function until the parameters of the multi-objective function are reduced to the minimum value. The parameters of the multi-objective function include the fan power consumption and fan noise of the piezoelectric fan. Determining the operating level of the piezoelectric fan based on the hot spot temperature of the power device in the heat dissipation device and the casing temperature of the heat dissipation device includes: When the hot spot temperature of the power device is less than or equal to the first device temperature threshold and the housing temperature is less than or equal to the first housing temperature threshold, the operating position of the piezoelectric fan is determined to be the off position. When the hot spot temperature of the power device is greater than a first device temperature threshold and the housing temperature is less than a second housing temperature threshold, the operating mode of the piezoelectric fan is determined to be the optimal low-power operating mode, where the first housing temperature threshold is less than the second housing temperature threshold; and When the hot spot temperature of the power device is greater than or equal to the second device temperature threshold and the housing temperature is greater than or equal to the second housing temperature threshold, the operating mode of the piezoelectric fan is determined to be the full power mode, and the first device temperature threshold is less than the second device temperature threshold.

2. The control method according to claim 1, characterized in that, The multi-objective function includes an initial function to be adjusted and an adjusted objective function. Adjusting the drive voltage and operating frequency of the piezoelectric fan according to the multi-objective function until the parameters of the multi-objective function are reduced to their minimum values ​​includes: Obtain the initial function, which includes the power consumption weight of the wind turbine power consumption and the noise weight of the wind turbine noise; Based on the surrounding environment of the piezoelectric fan, the power consumption weight and the noise weight are adjusted to obtain the objective function; and According to the objective function, the driving voltage and operating frequency of the piezoelectric fan are adjusted until the parameters of the objective function are reduced to their minimum values.

3. The control method according to claim 2, characterized in that, The step of adjusting the drive voltage and operating frequency of the piezoelectric fan according to the objective function until the parameters of the objective function are reduced to their minimum values ​​includes: Obtain the maximum value of the driving voltage, the lower limit coefficient of the heat dissipation capacity of the piezoelectric fan, and the number of blades of the piezoelectric fan; The minimum value of the driving voltage is obtained based on the lower limit coefficient of heat dissipation capacity and the number of blades; The range of values ​​for the driving voltage is determined based on the minimum and maximum values ​​of the driving voltage. Obtain multiple preset initial frequencies, and obtain multiple preset initial voltages based on the value range of the driving voltage; and The objective function is calculated based on the preset initial frequency and the preset initial voltage, and the preset initial frequency and the preset initial voltage corresponding to the minimum value of the objective function are respectively determined as the operating frequency and the driving voltage.

4. The control method according to claim 3, characterized in that, The step of obtaining the lower limit coefficient of the heat dissipation capacity of the piezoelectric fan includes: The heat generation of the piezoelectric fan is obtained based on the power loss ratio and the inverter output power; and The lower limit coefficient of heat dissipation capacity is determined based on the heat generation, the heat exchange surface area of ​​the piezoelectric fan, the hot spot temperature of the power device, and the ambient temperature.

5. The control method according to claim 3, characterized in that, The step of obtaining multiple preset initial frequencies and obtaining multiple preset initial voltages based on the value range of the driving voltage includes: According to a preset frequency step size, multiple preset initial frequencies are obtained, and according to a preset voltage step size and the value range of the driving voltage, multiple preset initial voltages are obtained.

6. The control method according to claim 3, characterized in that, The step of calculating the objective function based on the preset initial frequency and the preset initial voltage, and determining the preset initial frequency and the preset initial voltage corresponding to the minimum value of the objective function as the operating frequency and the driving voltage, respectively, includes: Obtain the load equivalent capacitance of the piezoelectric fan, and obtain the initial power consumption based on the load equivalent capacitance, the preset initial frequency, and the preset initial voltage; The initial noise is obtained based on the number of blades, the preset initial frequency, and the preset initial voltage; and Based on the initial power consumption and the initial noise, the objective function is obtained, and the preset initial frequency and the preset initial voltage corresponding to the minimum value of the objective function are respectively determined as the operating frequency and the driving voltage.

7. The control method according to claim 1, characterized in that, The control method further includes: When the piezoelectric blower is in the off position, control the piezoelectric blower to turn off; and When the piezoelectric fan is operating at full power, the drive voltage and the operating frequency are both increased to their maximum values.

8. A control device for a piezoelectric fan, characterized in that, The piezoelectric fan is connected to the equipment to be cooled, and the control device includes: The determining module is used to determine the operating level of the piezoelectric fan based on the hot spot temperature of the power device of the device to be cooled and the casing temperature of the device to be cooled. The operating levels include an off level, a low-power optimal operating level, and a full-power level. The adjustment module is used to adjust the drive voltage and operating frequency of the piezoelectric fan according to a multi-objective function when the piezoelectric fan is in the low-power optimal operating mode, until the parameters of the multi-objective function are reduced to the minimum value. The parameters of the multi-objective function include the fan power consumption and fan noise of the piezoelectric fan. Determining the operating level of the piezoelectric fan based on the hot spot temperature of the power device in the heat dissipation device and the casing temperature of the heat dissipation device includes: When the hot spot temperature of the power device is less than or equal to the first device temperature threshold and the housing temperature is less than or equal to the first housing temperature threshold, the operating position of the piezoelectric fan is determined to be the off position. When the hot spot temperature of the power device is greater than a first device temperature threshold and the housing temperature is less than a second housing temperature threshold, the operating mode of the piezoelectric fan is determined to be the optimal low-power operating mode, where the first housing temperature threshold is less than the second housing temperature threshold; and When the hot spot temperature of the power device is greater than or equal to the second device temperature threshold and the housing temperature is greater than or equal to the second housing temperature threshold, the operating mode of the piezoelectric fan is determined to be the full power mode, and the first device temperature threshold is less than the second device temperature threshold.

9. An electronic device, characterized in that, The electronic device includes the control device for the piezoelectric fan as described in claim 8.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the control method according to any one of claims 1-7.

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