A control method and system for a PCBA motor

Abstract

The application relates to the technical field of motor control, and discloses a control method and system for a PCBA motor, which comprises the following steps: obtaining the temperature of a cooling object, the rotating speed of the motor, the driving current, the temperature of a PCBA board and the temperature of a metal bottom plate; determining a target rotating speed according to the temperature of the cooling object; determining a load fluctuation parameter according to the rotating speed deviation and the driving current; determining a heat conduction representation parameter according to the temperature difference and the change rate of the PCBA board and the metal bottom plate; determining a current heat dissipation state according to the heat conduction representation parameter, and determining a start-up acceleration mode, a steady-state speed regulation mode or a heat inhibition mode in combination with the rotating speed deviation and the load fluctuation parameter; and outputting driving signals according to corresponding rules in different modes to control the conduction of the PCBA board winding and drive the rotation of the fan blade. The application intelligently selects a driving mode by comprehensively considering multiple-dimensional operation parameters, and solves the problem of poor matching between an existing control mode and actual heat dissipation requirements.

Description

Technical Field

[0001] This invention relates to the field of motor control technology, and more specifically, to a control method and system for PCBA motors. Background Technology

[0002] As computers, servers, display terminals, and other electronic devices develop towards higher integration and miniaturization, the heat generated by internal chips, power devices, and other heat-generating components during operation is constantly increasing. To ensure that these heat-generating components operate within a suitable temperature range, cooling fans are typically installed inside the equipment to remove heat promptly through airflow. The motor, as the core driving component of the cooling fan, directly affects the fan's airflow capacity and cooling effect.

[0003] In related technologies, the motors used in cooling fans are typically controlled according to preset speed curves, fixed speed settings, or based on a single detection parameter to achieve motor start-up, speed regulation, and operational maintenance. This type of control can meet basic cooling requirements under normal conditions. However, electronic equipment often experiences rapid load changes, uneven heat distribution, and frequent changes in operating conditions during actual operation, leading to corresponding changes in cooling requirements. In such cases, if the motor control process does not respond promptly to changes in operating status, or if the control strategy is not well-matched with the actual cooling requirements, a discrepancy may easily arise between the cooling fan's operating state and the equipment's current cooling needs.

[0004] Especially when electronic equipment is running continuously or under significant fluctuations in operating conditions, cooling fans need to maintain adequate airflow while ensuring good stability during motor operation. Existing control methods, due to their simplistic control criteria, struggle to meet the control requirements of different operating stages, thus affecting the overall adaptability of cooling fans under complex conditions. Summary of the Invention

[0005] In view of this, the present invention proposes a control method and system for PCBA motors, aiming to solve the problem of insufficient matching between the control process and actual heat dissipation requirements of PCBA motors in electronic device heat dissipation scenarios in the prior art.

[0006] In one aspect, the present invention proposes a control method for a PCBA motor, comprising: Acquire temperature data of the object being cooled, real-time speed data of the PCBA motor, drive current data, PCBA board temperature data, and temperature data of the metal base plate that is attached to the PCBA board; The target speed is determined based on the temperature data of the object being cooled; the speed deviation is determined based on the real-time speed data of the PCBA motor and the target speed; and the load fluctuation parameters are determined based on the drive current data; the thermal conductivity characterization parameters are determined based on the temperature difference between the PCBA board temperature data and the metal base plate temperature data, and the rate of change of the temperature difference. The current heat dissipation state is determined based on the comparison between the thermal conductivity characterization parameters and the preset thermal conductivity threshold, and the target driving mode is determined based on the speed deviation, the load fluctuation parameters and the current heat dissipation state. The target driving mode includes a start-up acceleration mode, a steady-state speed regulation mode and a thermal suppression mode. When in acceleration mode, a start drive signal is output according to the preset duty cycle climbing rule and the preset drive parameter climbing rule to control the PCBA motor to speed up to the target speed. When in steady-state speed regulation mode, the PWM drive duty cycle and drive parameters are adjusted according to the speed deviation and load fluctuation parameters, a steady-state drive signal is output, and the PCBA motor is controlled to run at the target speed. When in thermal suppression mode, the upper limit of the PWM drive duty cycle is limited according to the thermal conductivity characterization parameters, and the drive parameters are corrected according to the speed deviation, and a thermal suppression drive signal is output to control the PCBA motor to operate under limited drive conditions. The starting drive signal, the steady-state drive signal, or the heat suppression drive signal controls the windings on the PCBA board to conduct, thereby driving the heat dissipation fan blades to rotate.

[0007] Further, when determining the target rotational speed based on the temperature data of the object being cooled, the process includes: Obtain the current temperature value and target temperature value of the object being cooled; The temperature deviation value is determined based on the current temperature value and the target temperature value; The temperature deviation values ​​of different numerical ranges are divided into a first interval, a second interval, and a third interval in ascending order of value. The upper limit of the first interval is equal to the lower limit of the second interval, and the upper limit of the second interval is equal to the lower limit of the third interval. When the temperature deviation value is greater than or equal to the lower limit of the first interval and less than the upper limit of the first interval, a first target rotational speed is determined; When the temperature deviation value is greater than or equal to the lower limit of the second interval and less than the upper limit of the second interval, the second target rotational speed is determined according to the linear mapping relationship; When the temperature deviation value is greater than or equal to the lower limit of the third interval, the third target rotational speed is determined; The first target speed, the second target speed, or the third target speed is determined as the target speed.

[0008] Further, when determining the load fluctuation parameters based on the drive current data, the process includes: Within a continuous sampling window, acquire the drive current values ​​corresponding to multiple sampling moments; The average drive current value is determined based on each of the aforementioned drive current values; The current fluctuation amplitude is determined based on the absolute value of the difference between each of the aforementioned drive current values ​​and the average drive current value. The rate of change of current is determined by the difference between the driving current values ​​at adjacent sampling times and the sampling interval. The amplitude of the current fluctuation and the rate of change of the current are normalized. The load fluctuation parameters are obtained by weighting the normalized current fluctuation amplitude and the normalized current change rate.

[0009] Furthermore, when determining the thermal conductivity characterization parameters based on the temperature difference between the PCBA board temperature data and the metal substrate temperature data, and the rate of change of the temperature difference, the following steps are included: The temperature difference between the bottom of the board is determined based on the temperature data of the PCBA board and the temperature data of the metal base plate. The rate of change of temperature difference is determined based on the difference in temperature difference at the bottom of the plate between adjacent control cycles and the duration of the control cycle. The temperature difference at the bottom of the plate and the rate of change of the temperature difference are normalized. The normalized temperature difference at the bottom of the plate and the normalized rate of change of temperature difference are calculated according to the weighted fusion relationship to obtain the thermal conductivity characterization parameters.

[0010] Further, when determining the current heat dissipation state based on the comparison result between the thermal conductivity characterization parameters and the preset thermal conductivity threshold, the following steps are included: Based on the range of values ​​of the thermal conductivity characterization parameters, the normal heat dissipation range, the warning heat dissipation range, and the limited heat dissipation range are divided in ascending order of value. The maximum value of the normal heat dissipation range is less than the minimum value of the warning heat dissipation range, and the maximum value of the warning heat dissipation range is less than the minimum value of the limited heat dissipation range. When the thermal conductivity characterization parameters fall within the normal heat dissipation range, the current heat dissipation state is determined to be the normal heat dissipation state. When the thermal conductivity characterization parameter falls into the warning heat dissipation range, the current heat dissipation state is determined to be the warning heat dissipation state; When the thermal conductivity characterization parameters fall within the limited heat dissipation range, the current heat dissipation state is determined to be a limited heat dissipation state.

[0011] Further, when determining the target drive mode based on the speed deviation, the load fluctuation parameters, and the current heat dissipation status, the following steps are included: The starting speed range and the running speed range are divided according to the value range of the real-time speed in ascending order. The upper limit of the starting speed range is less than the lower limit of the running speed range. Based on the value range of the load fluctuation parameter, the stable fluctuation range and the enhanced fluctuation range are divided in ascending order of value. The upper limit of the stable fluctuation range is less than the lower limit of the enhanced fluctuation range. When the real-time rotational speed falls into the starting speed range, the target drive mode is determined to be the start-up acceleration mode; When the real-time speed falls within the operating speed range, the load fluctuation parameter falls within the stable fluctuation range, and the current heat dissipation state is a normal heat dissipation state or a warning heat dissipation state, the target drive mode is determined to be a steady-state speed regulation mode. When the current heat dissipation state is a limited heat dissipation state, the target driving mode is determined to be a thermal suppression mode; When the current heat dissipation state is a warning heat dissipation state and the load fluctuation parameter falls into the enhanced fluctuation range, the target driving mode is determined to be the heat suppression mode.

[0012] Furthermore, when in acceleration mode, the startup drive signal is output according to the preset duty cycle ramp-up rule and the preset drive parameter ramp-up rule, including: Set the initial duty cycle and initial drive frequency at startup; The range of the rotational speed deviation is divided into a large deviation range and a small deviation range in descending order of value, wherein the lower limit of the large deviation range is greater than the upper limit of the small deviation range. When the speed deviation falls into the large deviation range, the PWM drive duty cycle is increased according to the first ramp slope, and the drive frequency is adjusted according to the first frequency ramp amount. When the speed deviation falls into the small deviation range, the PWM drive duty cycle is increased according to the second ramp slope, and the drive frequency is adjusted according to the second frequency ramp amount. The first ramp slope is greater than the second ramp slope, and the first frequency ramp amount is greater than the second frequency ramp amount. The start-up drive signal is output based on the improved PWM drive duty cycle and the adjusted drive frequency.

[0013] Furthermore, when in steady-state speed regulation mode, adjusting the PWM drive duty cycle and drive parameters according to the speed deviation and load fluctuation parameters includes: Obtain the absolute value of the speed deviation; Based on the range of the absolute value of the speed deviation, the speed regulation dead zone and the speed regulation correction interval are divided in ascending order of value. The maximum value of the speed regulation dead zone is less than the minimum value of the speed regulation correction interval. When the absolute value of the speed deviation falls into the speed regulation dead zone and the load fluctuation parameter falls into the stable fluctuation range, the current PWM drive duty cycle and the current drive parameter remain unchanged. When the absolute value of the speed deviation falls into the speed regulation correction range and the load fluctuation parameter falls into the stable fluctuation range, the PWM drive duty cycle and drive parameters are increased when the real-time speed is lower than the target speed, and the PWM drive duty cycle and drive parameters are decreased when the real-time speed is higher than the target speed. When the load fluctuation parameters fall into the enhanced fluctuation range, the PWM drive duty cycle and drive parameters are adjusted according to the gradual slope.

[0014] Furthermore, when in thermal suppression mode, limiting the upper limit of the PWM drive duty cycle based on the thermal conductivity characterization parameters and correcting the drive parameters based on the speed deviation includes: Based on the range of values ​​of the thermal conductivity characterization parameters, the first thermal suppression interval and the second thermal suppression interval are divided in ascending order of value. The upper limit of the first thermal suppression interval is less than the lower limit of the second thermal suppression interval. When the thermal conductivity characterization parameters fall into the first thermal suppression range, the upper limit of the PWM drive duty cycle is reduced according to the first compression ratio, and the drive frequency is corrected according to the first frequency correction amount. When the thermal conductivity characterization parameter falls into the second thermal suppression range, the upper limit of the PWM drive duty cycle is reduced according to the second compression ratio, and the drive frequency is corrected according to the second frequency correction amount. The second compression ratio is greater than the first compression ratio, and the second frequency correction amount is greater than the first frequency correction amount. The thermal suppression drive signal is output based on the upper limit of the restricted PWM drive duty cycle and the corrected drive frequency.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: By acquiring the temperature data of the cooling object, the real-time speed data of the PCBA motor, the drive current data, the PCBA board temperature data, and the metal base plate temperature data, and determining the target speed, speed deviation, load fluctuation parameters, and thermal conductivity characterization parameters based on the above data, and then determining the corresponding target drive mode in combination with the current heat dissipation state, the control process of the PCBA motor no longer relies on the adjustment of a single parameter, but can comprehensively consider the heat dissipation requirements, motor operating status, and board-level thermal state changes. At the same time, by dividing the target drive mode into a start-up acceleration mode, a steady-state speed regulation mode, and a thermal suppression mode, and outputting corresponding drive signals in different modes, the PCBA motor can adopt different control methods in the start-up stage, the normal operation stage, and the thermal state tightening stage, which is beneficial to improving the adaptability between the control process and the current operating conditions. In addition, by controlling the winding on the PCBA board according to the start-up drive signal, the steady-state drive signal, or the thermal suppression drive signal, the rotation state of the heat dissipation fan can be specifically adjusted, thereby better balancing the heat dissipation requirements and the thermal state changes of the PCBA board.

[0016] On the other hand, this application also provides a control system for a PCBA motor, for implementing the above-described control method for a PCBA motor, including: The data acquisition module is configured to acquire temperature data of the object being cooled, real-time speed data of the PCBA motor, drive current data, PCBA board temperature data, and temperature data of the metal base plate that is attached to the PCBA board. The operating parameter determination module is configured to determine the target speed based on the temperature data of the object being cooled; determine the speed deviation based on the real-time speed data of the PCBA motor and the target speed; determine the load fluctuation parameters based on the drive current data; and determine the thermal conductivity characterization parameters based on the temperature difference between the PCBA board temperature data and the metal base plate temperature data and the rate of change of the temperature difference. The drive mode determination module is configured to determine the current heat dissipation state based on the comparison between the thermal conductivity characterization parameters and the preset thermal conductivity threshold, and to determine the target drive mode based on the speed deviation, load fluctuation parameters and the current heat dissipation state. The target drive mode includes start-up acceleration mode, steady-state speed regulation mode and thermal suppression mode. The startup acceleration control module is configured to output a startup drive signal according to the preset duty cycle climbing rule and the preset drive parameter climbing rule when the startup acceleration mode is in operation, thereby controlling the PCBA motor to accelerate to the target speed. The steady-state speed control module is configured to adjust the PWM drive duty cycle and drive parameters according to the speed deviation and load fluctuation parameters when in steady-state speed control mode, output a steady-state drive signal, and control the PCBA motor to run at the target speed. The thermal suppression control module is configured to limit the upper limit of the PWM drive duty cycle according to the thermal conductivity characterization parameters when in thermal suppression mode, and to correct the drive parameters according to the speed deviation, and output a thermal suppression drive signal to control the PCBA motor to run under limited drive conditions. The drive execution module is configured to control the windings set on the PCBA board to conduct according to the start drive signal, steady-state drive signal or thermal suppression drive signal, thereby driving the heat dissipation fan blades to rotate.

[0017] It is understandable that the aforementioned control system and method for PCBA motors have the same beneficial effects, and will not be repeated here. Attached Figure Description

[0018] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 A flowchart of a control method for a PCBA motor provided in an embodiment of the present invention; Figure 2 This is a functional block diagram of a control system for a PCBA motor provided in an embodiment of the present invention. Detailed Implementation

[0019] Exemplary embodiments of the present invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specified, embodiments and features in the embodiments of the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0020] See Figure 1 As shown, this application proposes a control method for a PCBA motor, comprising: S1: Acquire temperature data of the object being cooled, real-time speed data of the PCBA motor, drive current data, PCBA board temperature data, and temperature data of the metal base plate that is attached to the PCBA board; S2: Determine the target speed based on the temperature data of the object being cooled; determine the speed deviation based on the real-time speed data of the PCBA motor and the target speed, and determine the load fluctuation parameters based on the drive current data; determine the thermal conductivity characterization parameters based on the temperature difference between the PCBA board temperature data and the metal base plate temperature data and the rate of change of the temperature difference. S3: Determine the current heat dissipation state based on the comparison results between the thermal conductivity characterization parameters and the preset thermal conductivity threshold, and determine the target drive mode based on the speed deviation, load fluctuation parameters and the current heat dissipation state. The target drive mode includes start-up acceleration mode, steady-state speed regulation mode and thermal suppression mode. S4: When in start-up acceleration mode, output start-up drive signal according to preset duty cycle climbing rules and preset drive parameter climbing rules to control PCBA motor to speed up to the target speed; S5: When in steady-state speed regulation mode, the PWM drive duty cycle and drive parameters are adjusted according to the speed deviation and load fluctuation parameters, a steady-state drive signal is output, and the PCBA motor is controlled to run at the target speed. S6: When in thermal suppression mode, the upper limit of the PWM drive duty cycle is limited according to the thermal conductivity characterization parameters, and the drive parameters are corrected according to the speed deviation. The thermal suppression drive signal is output to control the PCBA motor to run under limited drive conditions. S7: Controls the windings set on the PCBA board to conduct according to the start drive signal, steady-state drive signal or thermal suppression drive signal, driving the heat dissipation fan blades to rotate.

[0021] Specifically, the cooling target can be a heat-generating chip, power device, or other component requiring airflow cooling on a computer motherboard. Temperature data can be acquired by a temperature sensor located near the cooling target. Real-time speed data can be calculated using a motor speed measurement circuit, back EMF detection signal, or speed feedback circuit. Drive current data can be obtained by a sampling resistor or current sensor. PCBA board temperature data and metal base plate temperature data are acquired by temperature sensors located in the heat-generating area of ​​the PCBA board and the contact area of ​​the metal base plate, respectively. When determining the target speed based on the temperature data of the cooling target, a temperature rise calibration test can be performed on the prototype beforehand. The temperature changes of the cooling target under different heating conditions and different fan speeds can be recorded, and a correspondence between the cooling target temperature and the target speed can be established. For example, the target operating temperature range of the cooling target can be determined first, and then the deviation between the current temperature and the target operating temperature range can be mapped to different speed levels to obtain a target speed that matches the current heat dissipation requirements. When determining the speed deviation based on the real-time speed data and the target speed, the current real-time speed can be compared with the target speed, and the difference between the two can be used as the basis for subsequent adjustments. When determining the load fluctuation parameters based on the drive current data, the drive current can be acquired at multiple consecutive sampling times. To determine the current value, first determine the average level of the drive current within a given time period, then analyze the fluctuation of the drive current relative to the average level at each sampling moment. Simultaneously, further analyze the rate of change of the drive current between adjacent sampling moments. Then, combine the data reflecting the fluctuation amplitude and the data reflecting the rate of change with a unified dimension and proportionally synthesize them into a comprehensive parameter. The synthesis ratio can be determined through calibration tests under no-load, rated load, and sudden load change conditions. When determining the thermal conductivity characterization parameters based on the temperature difference between the PCBA board temperature data and the metal base plate temperature data, and the rate of change of the temperature difference, first determine the difference between the PCBA board temperature and the metal base plate temperature, then compare the values ​​within adjacent control cycles. The variation of the difference reflects the temperature difference level and its trend when heat is transferred to the metal base plate. Then, the data reflecting the current temperature difference magnitude and the data reflecting the rate of temperature difference change are normalized and fused according to the pre-calibrated weights to obtain the thermal conductivity characterization parameters. The weights can be obtained by fitting multiple sets of thermal test results. The preset thermal conductivity threshold can be determined through thermal calibration. Specifically, the value range of the thermal conductivity characterization parameters can be collected under normal heat dissipation conditions, heat dissipation under stress conditions, and heat dissipation under significantly limited conditions. Combined with the safety margin of the allowable temperature rise of key components of the PCBA board, the boundary value between different heat dissipation states is selected to ensure that the threshold has a clear source.After obtaining the speed deviation, load fluctuation parameters, and thermal conductivity parameters, the current heat dissipation status can be determined based on the range of the thermal conductivity parameters. Then, the target drive mode can be determined by combining the real-time speed stage and the degree of load fluctuation. Specifically, the start-up acceleration mode is suitable for situations where the motor is starting or accelerating at low speed; the steady-state speed regulation mode is suitable for situations where the motor has entered its normal operating range and the system state is relatively stable; and the thermal suppression mode is suitable for situations where the thermal conductivity deteriorates or the thermal load increases. In the start-up acceleration mode, the duty cycle ramp-up rules and drive parameter ramp-up rules can be obtained through start-up calibration tests. For example, the start-up success rate, start-up time, and temperature rise level can be tested under different duty cycle ramp-up speeds and different drive frequency ramp-up speeds, and a mode that balances start-up reliability and temperature rise control can be selected. The control mechanism operates as follows: In steady-state speed regulation mode, the PWM drive duty cycle can be adjusted according to the speed deviation, and the drive frequency can be fine-tuned synchronously in conjunction with load fluctuation parameters to gradually bring the actual speed closer to the target speed. In thermal suppression mode, the upper limit of the PWM drive duty cycle can be limited according to the level of the thermal conductivity parameter. The higher the thermal conductivity parameter, the greater the compression of the upper limit of the duty cycle. At the same time, the drive frequency is corrected in conjunction with the speed deviation to balance heat dissipation requirements and board-level heat control. Finally, the controller controls the windings set on the PCBA board to conduct sequentially according to the start drive signal, steady-state drive signal, or thermal suppression drive signal generated corresponding to the current target drive mode, thereby driving the cooling fan blades to rotate, realizing closed-loop control for different heat dissipation requirements and operating states.

[0022] In some embodiments of this application, determining the target rotational speed based on the temperature data of the object being cooled includes: Obtain the current temperature and target temperature of the object being cooled; Determine the temperature deviation value based on the current temperature value and the target temperature value; The temperature deviation values ​​of different numerical ranges are divided into three intervals in ascending order: the first interval, the second interval, and the third interval. The upper limit of the first interval is equal to the lower limit of the second interval, and the upper limit of the second interval is equal to the lower limit of the third interval. When the temperature deviation value is greater than or equal to the lower limit of the first interval and less than the upper limit of the first interval, the first target rotational speed is determined; When the temperature deviation value is greater than or equal to the lower limit of the second interval and less than the upper limit of the second interval, the second target rotational speed is determined according to the linear mapping relationship; When the temperature deviation is greater than or equal to the lower limit of the third interval, the third target rotational speed is determined; The first target speed, the second target speed, or the third target speed is determined as the target speed.

[0023] Specifically, the current temperature value can be acquired in real time by a temperature sensor located near the object being cooled. The target temperature value can be preset based on the allowable operating temperature range, long-term stable operating temperature requirements, and product heat dissipation design specifications of the object being cooled. For example, when the object being cooled is a chip, the target temperature value can be the safe temperature value below the upper limit of the chip's recommended operating temperature. After obtaining the current and target temperature values, the current and target temperature values ​​can be compared, and the difference between them can be used as the temperature deviation value. The larger the temperature deviation value, the higher the current heat dissipation requirement. The division of the first, second, and third intervals can be determined through prototype testing, historical operating data statistics, or calibration tests. Specifically, temperature change data of the object being cooled can be collected under different ambient temperatures, different load levels, and different fan speeds. Combined with the fan speed corresponding to the stable temperature of the object being cooled, the speed adjustment intervals corresponding to different temperature deviation value ranges can be determined. The range with a small temperature deviation and the temperature of the object being cooled is close to the target temperature value, which can be divided into the first interval; the range with a continuously increasing temperature deviation and in a stable speed adjustment stage, which can be divided into the second interval; and the range with a large temperature deviation and requiring increased heat dissipation output, which can be divided into the third interval. The system consists of three intervals. The upper limit of the first interval equals the lower limit of the second interval, and the upper limit of the second interval equals the lower limit of the third interval. Adjacent intervals are connected end-to-end. Boundary values ​​are assigned to the next adjacent interval according to the rule of "greater than or equal to the lower limit and less than the upper limit," ensuring no overlap or uncovered numerical gaps between intervals. When the temperature deviation falls within the first interval, a first target speed can be determined. This first target speed can be a lower speed or a base maintenance speed, such as a fixed speed value within a lower percentage range of the rated speed. When the temperature deviation falls within the second interval, a second target speed is determined according to a linear mapping relationship. The linear mapping relationship can be obtained through calibration. Specifically, a linear correspondence between the temperature deviation value and the target speed can be established based on the starting speed corresponding to the lower limit of the second interval and the upper limit of the target speed corresponding to the upper limit of the second interval. This ensures that as the temperature deviation value increases within the second interval, the target speed increases proportionally. When the temperature deviation value falls into the third interval, the third target speed can be determined. The third target speed can be a higher speed value, such as a speed value close to the upper limit of the rated speed. Finally, based on the interval in which the temperature deviation value is located, the corresponding value is selected from the first target speed, the second target speed, and the third target speed as the target speed.

[0024] In some embodiments of this application, determining load fluctuation parameters based on drive current data includes: Within a continuous sampling window, acquire the drive current values ​​corresponding to multiple sampling moments; The average drive current value is determined based on each drive current value; The current fluctuation amplitude is determined based on the absolute value of the difference between each drive current value and the average drive current value. The rate of change of current is determined by the difference between the driving current values ​​at adjacent sampling times and the sampling interval. The amplitude of current fluctuations and the rate of change of current are normalized. The load fluctuation parameters are obtained by weighting the normalized current fluctuation amplitude and the normalized current change rate.

[0025] Specifically, drive current data can be acquired through sampling resistors, current detection chips, or Hall current sensors installed in the motor drive circuit. A continuous sampling window refers to a data set formed by sampling the drive current multiple times within a continuous time period. Its length can be set according to the motor control cycle and load change rate; for example, it can be the time length corresponding to several to dozens of control cycles to balance data stability and response speed. After acquiring drive current values ​​corresponding to multiple sampling moments within this continuous sampling window, the drive current values ​​at each sampling moment can be statistically processed to obtain the average drive current value within that time period. The average drive current value reflects the current... The overall level of the motor drive current in the previous stage is determined. Based on this, the drive current value at each sampling time is compared with the average drive current value, and the absolute value of each comparison result is taken to characterize the degree of deviation of each sampling point from the average level. Then, the current fluctuation amplitude is determined based on these deviations. The current fluctuation amplitude can be the maximum value among the absolute differences, or the average value of multiple absolute differences, or a weighted average value. The specific method can be selected based on the prototype test results. At the same time, the change of drive current between adjacent sampling times can also be analyzed, that is, the drive current values ​​of two adjacent sampling times are compared and combined with the difference between the two sampling times. The sampling interval is used to determine the rate of change of current per unit time, thus obtaining the current change rate, which reflects whether the load change is gradual or abrupt. Since the current fluctuation amplitude and current change rate are usually inconsistent in numerical range and dimensions, they can be normalized before subsequent comprehensive processing to map them to a unified numerical range. For example, by combining the test results of the prototype under no-load, rated load, and sudden load change conditions, reference upper and lower limits for current fluctuation amplitude and current change rate can be determined respectively. Then, the actual collected values ​​are converted into dimensionless values ​​according to the corresponding reference ranges. After normalization, the normalized current fluctuation amplitude... The load fluctuation parameters are obtained by weighting the value and the normalized rate of change of current. The weighting coefficients can be obtained through calibration tests or analysis of historical operating data. For example, when sudden load changes are more likely to affect the stability of motor operation in actual application scenarios, the weight of the rate of change of current can be appropriately increased. When load fluctuations are mainly manifested as amplitude changes in actual application scenarios, the weight of the amplitude of current fluctuations can be appropriately increased. The load fluctuation parameters obtained in this way do not simply represent the magnitude of the drive current, but rather a parameter that comprehensively reflects the degree and rate of change of the current load. It can be used as a basis for subsequently determining the target drive mode and adjusting the drive parameters.

[0026] In some embodiments of this application, determining the thermal conductivity characterization parameters based on the temperature difference between the PCBA board temperature data and the metal substrate temperature data, and the rate of change of the temperature difference, includes: Determine the temperature difference between the board bottom and the metal substrate based on the PCBA board temperature data and the metal substrate temperature data. The rate of change of temperature difference is determined based on the difference in temperature difference at the bottom of the plate between adjacent control cycles and the duration of the control cycle. The temperature difference at the bottom of the plate and the rate of change of temperature difference were normalized. The normalized temperature difference at the bottom of the plate and the rate of change of temperature difference were calculated based on the weighted fusion relationship to obtain the thermal conductivity characterization parameters.

[0027] Specifically, PCBA board temperature data can be collected by temperature sensors located in the heat-concentrating areas of the PCBA board or near the driving components and winding areas. Metal substrate temperature data can be collected by temperature sensors located at the corresponding positions in the area where the PCBA board is in contact with the metal substrate. By acquiring temperature data from these two locations, the heat transfer between the PCBA board and the metal substrate can be reflected. After obtaining the PCBA board temperature data and the metal substrate temperature data, they can be compared. The difference between the PCBA board temperature and the metal substrate temperature is taken as the board-substrate temperature difference. A larger board-substrate temperature difference usually indicates a significant temperature gradient in the heat transfer process between the PCBA board and the metal substrate. Furthermore, the change in board-substrate temperature difference within adjacent control cycles can be compared. That is, the board-substrate temperature difference of the previous control cycle and the current control cycle are obtained, and combined with the duration between the two control cycles, the rate of change of the board-substrate temperature difference per unit time is determined as the temperature difference change rate. The temperature difference change rate reflects whether the board-substrate temperature difference is continuously increasing, basically stable, or gradually decreasing. Since the board-substrate temperature difference and the temperature difference change rate are usually not consistent in numerical range and dimensions... Therefore, before comprehensively processing both, normalization can be performed first to convert them to a unified numerical scale. The reference range for normalization can be determined through thermal calibration experiments. For example, data on the temperature difference and rate of change of the plate bottom can be collected under normal heat dissipation, boundary heat dissipation, and limited heat dissipation conditions, respectively, and then the upper and lower reference limits can be determined accordingly. After normalization, the normalized plate bottom temperature difference and the normalized rate of change of the temperature difference are comprehensively calculated according to the weighted fusion relationship to obtain the thermal conductivity characterization parameters. The weights of each component in the system can be determined through prototype thermal testing, long-term operational data statistics, or temperature rise experiments under different environmental conditions. For example, when the temperature difference at the bottom of the plate is more directly reflected in the change of thermal state in practical applications, the weight corresponding to the temperature difference at the bottom of the plate can be appropriately increased. Conversely, when the trend of temperature difference change is more sensitive to the judgment of thermal risk in practical applications, the weight corresponding to the rate of change of temperature difference can be appropriately increased. The thermal conductivity characterization parameters obtained in this way do not simply represent the temperature difference value at a certain moment, but rather are parameters that comprehensively reflect the current level of temperature difference at the bottom of the plate and its changing trend, which can be used as the basis for subsequently determining the heat dissipation state and switching the target driving mode.

[0028] In some embodiments of this application, determining the current heat dissipation state based on a comparison between thermal conductivity characterization parameters and a preset thermal conductivity threshold includes: Based on the range of values ​​of the thermal conductivity characterization parameters, the normal heat dissipation range, the warning heat dissipation range, and the limited heat dissipation range are divided in ascending order of value. The maximum value of the normal heat dissipation range is less than the minimum value of the warning heat dissipation range, and the maximum value of the warning heat dissipation range is less than the minimum value of the limited heat dissipation range. When the thermal conductivity characterization parameters fall within the normal heat dissipation range, the current heat dissipation state is determined to be the normal heat dissipation state. When the thermal conductivity characterization parameters fall into the warning heat dissipation range, the current heat dissipation state is determined to be the warning heat dissipation state; When the thermal conductivity characterization parameters fall within the limited heat dissipation range, the current heat dissipation state is determined to be a limited heat dissipation state.

[0029] Specifically, after obtaining the thermal conductivity characterization parameters, the current heat dissipation state can be graded based on their values. To this end, the state division intervals corresponding to the thermal conductivity characterization parameters can be determined in advance by combining the prototype thermal test results, operating data under different ambient temperatures, and the allowable temperature rise range of key components on the PCBA board. Specifically, the distribution data of the thermal conductivity characterization parameters can be collected under various operating conditions such as normal load, high load, and limited heat dissipation. Combined with the PCBA board temperature, metal substrate temperature, and system stability, the typical value ranges of the thermal conductivity characterization parameters under various operating conditions can be statistically analyzed. Based on this, the thermal conductivity characterization parameters are divided into normal heat dissipation intervals, warning heat dissipation intervals, and limited heat dissipation intervals in ascending order of value. The normal heat dissipation interval corresponds to a state where the temperature difference at the bottom of the board is small and the temperature difference change is relatively gradual. The warning heat dissipation interval corresponds to a state where the temperature difference at the bottom of the board has increased or the temperature difference change trend has begun to accelerate but has not yet reached a significant limiting level. The limited heat dissipation interval corresponds to a state where the temperature difference at the bottom of the board is large and the temperature difference change continues to worsen. The maximum value of the normal heat dissipation interval is smaller than that of the warning heat dissipation interval. The minimum value of the warning heat dissipation range is less than the minimum value of the restricted heat dissipation range, thus ensuring that there is no overlap between the ranges and avoiding multiple heat dissipation states corresponding to the same thermal conductivity parameter. The boundary values ​​of the above ranges can be determined based on the statistical results of thermal test data. For example, the common upper limit of the thermal conductivity parameter during long-term stable operation can be statistically analyzed and used as the upper boundary of the normal heat dissipation range. Then, the upper and lower boundaries of the warning heat dissipation range can be determined by combining the range of thermal conductivity parameters where the heat dissipation capacity begins to decline but the system can still operate. Data that exceeds this range and is close to the device's allowable temperature rise boundary are corresponding to the restricted heat dissipation range. If necessary, a certain safety margin can be introduced on the basis of statistical boundaries to improve the stability of the judgment. In actual operation, when the thermal conductivity parameter falls into the normal heat dissipation range, the current heat dissipation state is determined to be the normal heat dissipation state. When the thermal conductivity parameter falls into the warning heat dissipation range, the current heat dissipation state is determined to be the warning heat dissipation state. When the thermal conductivity parameter falls into the restricted heat dissipation range, the current heat dissipation state is determined to be the restricted heat dissipation state. This realizes the graded judgment of heat dissipation state based on the numerical range of thermal conductivity parameters.

[0030] In some embodiments of this application, determining the target drive mode based on the rotational speed deviation, load fluctuation parameters, and current heat dissipation status includes: Based on the range of real-time rotational speed values, the starting speed range and the running speed range are divided in ascending order of value. The upper limit of the starting speed range is less than the lower limit of the running speed range. Based on the range of values ​​of the load fluctuation parameter, the stable fluctuation range and the enhanced fluctuation range are divided in ascending order of value. The upper limit of the stable fluctuation range is less than the lower limit of the enhanced fluctuation range. When the real-time speed falls into the starting speed range, the target drive mode is determined to be the start-up acceleration mode; When the real-time speed falls within the operating speed range, the load fluctuation parameters fall within the stable fluctuation range, and the current heat dissipation status is normal or warning heat dissipation status, the target drive mode is determined to be steady-state speed regulation mode. When the current heat dissipation state is a limited heat dissipation state, the target driving mode is determined to be the thermal suppression mode; When the current heat dissipation status is a warning heat dissipation status and the load fluctuation parameters fall into the enhanced fluctuation range, the target driving mode is determined to be the thermal suppression mode.

[0031] Specifically, after obtaining the speed deviation, load fluctuation parameters, and current heat dissipation status, a comprehensive judgment can be made on the current control situation based on the motor's current speed stage, the degree of load change, and the level of heat dissipation status to determine the target drive mode that matches the current operating conditions. The starting speed range and the operating speed range can be determined based on prototype start-up tests and stable operation tests. Specifically, speed change data of the motor from standstill to stable operation can be collected under different power supply conditions and load conditions. The speed range where the motor has not yet left the starting stage, has large speed fluctuations, and has not yet established a stable airflow output is divided into the starting speed range, and the speed range where the motor has already entered the starting stage is divided into the operating speed range. The operating speed range is defined as the range of speeds that allow for continuous and stable operation and maintain a relatively stable airflow output. The upper limit of the starting speed range is set lower than the lower limit of the operating speed range to avoid mode overlap. The stable fluctuation range and the enhanced fluctuation range can be defined based on the statistical results of load fluctuation parameters under different load conditions. For example, the distribution range of load fluctuation parameters can be collected under no-load, rated load, and rapid load change conditions. The range of values ​​corresponding to small and gradual current fluctuations is defined as the stable fluctuation range, while the range of values ​​corresponding to significantly increased current fluctuations or a significantly faster rate of change is defined as the enhanced fluctuation range. The stable fluctuation range is further defined as... The upper limit is less than the lower limit of the enhanced fluctuation range; in actual control, when the real-time speed falls into the starting speed range, it indicates that the motor is still in the stage of increasing from standstill or low speed to the target speed. At this time, the target drive mode is determined to be the start-up acceleration mode; when the real-time speed falls into the operating speed range, the load fluctuation parameters fall into the stable fluctuation range, and the current heat dissipation state is normal heat dissipation state or warning heat dissipation state, it indicates that the motor has entered the stage where it can maintain continuous operation, and the load change is relatively stable. Although the thermal state has changed to some extent in the warning heat dissipation state, it has not yet reached the level that requires immediate suppression of output. Therefore, the target drive mode is determined to be the steady-state speed regulation mode; when the current heat dissipation... When the thermal state is a limited heat dissipation state, it indicates that the board-level thermal conductivity has deteriorated significantly or the degree of heat accumulation is already high. To prevent the heat load from continuing to increase, the target drive mode can be directly determined as the thermal suppression mode. In addition, when the current heat dissipation state is a warning heat dissipation state and the load fluctuation parameters fall into the enhanced fluctuation range, it indicates that the system not only has a tight thermal state, but also that the load changes are more obvious, and the factors of operational instability have further increased. At this time, the target drive mode is also determined as the thermal suppression mode. Through the above determination method, the basis for switching between different modes can be clearly derived, and different drive control strategies can be corresponding to the startup phase, the stable operation phase, and the thermal risk increase phase.

[0032] In some embodiments of this application, when the startup acceleration mode is active, outputting the startup drive signal according to the preset duty cycle ramp-up rule and the preset drive parameter ramp-up rule includes: Set the initial duty cycle and initial drive frequency at startup; Based on the range of values ​​for the speed deviation, the large deviation range and the small deviation range are divided in descending order of value. The lower limit of the large deviation range is greater than the upper limit of the small deviation range. When the speed deviation falls into the large deviation range, the PWM drive duty cycle is increased according to the first ramp slope, and the drive frequency is adjusted according to the first frequency ramp amount. When the speed deviation falls into the small deviation range, the PWM drive duty cycle is increased according to the second ramp slope, and the drive frequency is adjusted according to the second frequency ramp amount. The first ramp slope is greater than the second ramp slope, and the first frequency ramp amount is greater than the second frequency ramp amount. The start drive signal is output based on the improved PWM drive duty cycle and the adjusted drive frequency.

[0033] Specifically, when the motor is in start-up acceleration mode, the control objective is to smoothly accelerate the motor from a standstill or low speed to the target speed, while avoiding start-up failure, increased vibration, or excessive temperature rise caused by excessively rapid increase in duty cycle or abrupt changes in drive frequency during the start-up phase. The initial duty cycle and initial drive frequency can be predetermined through prototype start-up calibration tests. Specifically, under different ambient temperatures, different supply voltages, and different mechanical loads, the start-up success rate, start-up response time, and temperature rise during the start-up phase are tested under multiple combinations of initial duty cycles and initial drive frequencies, selecting a frequency that balances start-up reliability and thermal stability. The combination of these parameters serves as the initial duty cycle and initial drive frequency for startup. For example, the initial duty cycle can be selected as a value slightly higher than the critical duty cycle for motor startup, and the initial drive frequency can be selected as a lower frequency value that ensures stable starting torque output. During startup, the speed deviation reflects the difference between the current real-time speed and the target speed. To facilitate graded control, the range of speed deviation values ​​can be divided into large deviation ranges and small deviation ranges according to the speed catch-up situation of the prototype at different startup stages. The large deviation range corresponds to the stage where the motor has not yet established a stable acceleration state and the difference from the target speed is large, while the small deviation range corresponds to the stage where the motor is already close to the target speed. During the initial speed deviation phase, the adjustment range needs to be reduced to avoid overshoot, and the lower limit of the large deviation range should be greater than the upper limit of the small deviation range to ensure no overlap between them. When the speed deviation falls into the large deviation range, it indicates that the current speed is significantly lower than the target speed, and the drive force needs to be increased. At this time, the PWM drive duty cycle is increased according to the first ramp slope, and the drive frequency is adjusted according to the first frequency ramp amount. The first ramp slope and the first frequency ramp amount can be determined through a start-up test, and are usually selected to allow the motor to quickly establish speed without causing excessive current surge. When the speed deviation falls into the small deviation range, it indicates that the current real-time speed is gradually approaching the target speed. At this point, the PWM drive duty cycle is increased according to the second ramp rate, and the drive frequency is adjusted according to the second frequency ramp amount to allow the motor to continue accelerating but reduce the intensity of adjustment, avoiding overshoot and oscillation. The second ramp rate and the second frequency ramp amount are both less than the corresponding first ramp rate and the first frequency ramp amount, and their values ​​can also be obtained through multiple sets of start-up condition tests. After the duty cycle and drive frequency are increased, the controller generates a start-up drive signal based on the updated PWM drive duty cycle and drive frequency, and outputs the start-up drive signal to the drive circuit to control the windings set on the PCBA board to conduct sequentially, so that the motor accelerates in layers according to the size of the deviation during the start-up phase.

[0034] In some embodiments of this application, when adjusting the PWM drive duty cycle and drive parameters according to the speed deviation and load fluctuation parameters in steady-state speed regulation mode, the following steps are included: Obtain the absolute value of the speed deviation; Based on the range of absolute values ​​of speed deviation, the speed regulation dead zone and speed regulation correction zone are divided in ascending order of value. The maximum value of the speed regulation dead zone is less than the minimum value of the speed regulation correction zone. When the absolute value of the speed deviation falls into the speed regulation dead zone and the load fluctuation parameters fall into the stable fluctuation range, the current PWM drive duty cycle and the current drive parameters remain unchanged. When the absolute value of the speed deviation falls within the speed regulation correction range and the load fluctuation parameter falls within the stable fluctuation range, increase the PWM drive duty cycle and drive parameters when the real-time speed is lower than the target speed, and decrease the PWM drive duty cycle and drive parameters when the real-time speed is higher than the target speed. When the load fluctuation parameters fall into the enhanced fluctuation range, the PWM drive duty cycle and drive parameters are adjusted according to the gradual slope.

[0035] Specifically, when the motor is in steady-state speed regulation mode, the control objective is no longer rapid start-up, but rather to suppress fluctuations caused by frequent adjustments while maintaining the target speed as much as possible. Therefore, the absolute value of the speed deviation can be obtained first to reflect only the degree of deviation between the current actual speed and the target speed, without distinguishing the direction of deviation. Based on this, according to the results of the prototype's steady-state operation test, long-term operation data, or statistical results of speed fluctuations under different load conditions, the range of the absolute value of the speed deviation can be divided into a speed regulation dead zone and a speed regulation correction interval in ascending order of value. The speed regulation dead zone corresponds to the range where the deviation between the actual speed and the target speed is small, the impact on heat dissipation is not significant, and no immediate adjustment is required. The speed regulation correction interval... The corresponding deviation has reached the range requiring active correction. To avoid triggering two types of control actions simultaneously with the same deviation value, the maximum value of the speed dead zone is less than the minimum value of the speed correction interval. In this embodiment, the drive parameter can be the drive frequency or a commutation cycle parameter that changes synchronously with the drive frequency, preferably the drive frequency. When the absolute value of the speed deviation falls into the speed dead zone and the load fluctuation parameter falls into the stable fluctuation range, it indicates that the motor's current operating state is basically stable, the difference between the actual speed and the target speed is within the allowable range, and the load change is not significant. At this time, the current PWM drive duty cycle and the current drive parameters are kept unchanged to avoid unnecessary fluctuations due to overly sensitive adjustment. When the absolute value of the speed deviation falls into the speed correction interval... When the load fluctuation parameters still fall within the stable fluctuation range, it indicates that although the overall load of the motor is relatively stable, the actual speed has deviated from the target speed to a degree that requires correction. At this time, differentiated adjustments can be made based on the direction of the real-time speed relative to the target speed. That is, when the real-time speed is lower than the target speed, the PWM drive duty cycle and drive parameters are increased to improve the driving force and speed; when the real-time speed is higher than the target speed, the PWM drive duty cycle and drive parameters are decreased to reduce the driving force and suppress the speed from continuing to rise. The adjustment range of the duty cycle and drive parameters can be determined through steady-state calibration tests. Specifically, the speed recovery time and speed fluctuation after adjustment can be tested under different target speeds, different ambient temperatures, and different load levels. The dynamic range and temperature rise level are selected, and parameters that balance speed regulation sensitivity and operational stability are chosen. When the load fluctuation parameters fall into the enhanced fluctuation range, it indicates that the current load change is relatively obvious. If a faster adjustment method is still used, it is easy to cause frequent changes in duty cycle and drive parameters, which in turn leads to motor oscillation. Therefore, in this case, the PWM drive duty cycle and drive parameters are adjusted according to the gradual slope. The gradual slope can be understood as an adjustment speed that is smaller than the normal correction slope. Its value can be determined through load change test. For example, under the conditions of changes in duct resistance, external airflow disturbance or instantaneous changes in mechanical load, the speed stability and current fluctuation corresponding to different adjustment speeds are compared, and the adjustment slope that can reduce oscillation and maintain speed regulation continuity is selected.By employing the above methods, in steady-state speed regulation mode, ineffective adjustments can be avoided when the deviation is small, clear corrections can be made when the deviation increases, and the degree of adjustment abruptness can be reduced when load fluctuations intensify, thereby improving the control smoothness during steady-state motor operation.

[0036] In some embodiments of this application, when in thermal suppression mode, limiting the upper limit of the PWM drive duty cycle based on thermal conductivity parameters and correcting the drive parameters based on the speed deviation includes: Based on the range of values ​​of the thermal conductivity characterization parameters, the first thermal suppression interval and the second thermal suppression interval are divided in ascending order of value. The upper limit of the first thermal suppression interval is less than the lower limit of the second thermal suppression interval. When the thermal conductivity characterization parameters fall into the first thermal suppression range, the upper limit of the PWM drive duty cycle is reduced according to the first compression ratio, and the drive frequency is corrected according to the first frequency correction amount. When the thermal conductivity characterization parameters fall into the second thermal suppression range, the upper limit of the PWM drive duty cycle is reduced according to the second compression ratio, and the drive frequency is corrected according to the second frequency correction amount. The second compression ratio is greater than the first compression ratio, and the second frequency correction amount is greater than the first frequency correction amount. The thermal suppression drive signal is output based on the upper limit of the PWM drive duty cycle after the limitation and the corrected drive frequency.

[0037] Specifically, when the motor enters the thermal suppression mode, it indicates that the heat transfer between the PCBA board and the metal base plate has become tight or restricted. At this time, the control focus is no longer just on maintaining the speed, but on constraining the drive output to prevent the local temperature rise of the PCBA board from continuing to increase. To this end, based on the prototype thermal test results, long-term operating data under different ambient temperatures, and the allowable temperature rise range of key components, the range of values ​​for the thermal conductivity characterization parameters can be further divided into a first thermal suppression interval and a second thermal suppression interval. The first thermal suppression interval corresponds to a situation where the thermal state has deviated from normal but has not yet reached a high level of thermal risk, while the second thermal suppression interval corresponds to a situation where the thermal state has further deteriorated and stronger suppression measures are required. Furthermore, the upper limit of the first thermal suppression interval is lower than the lower limit of the second thermal suppression interval to ensure that there is no overlap between them; the first compression ratio and the second compression ratio can be determined through thermal calibration tests. Specifically, the temperature rise of the PCBA board, the output capacity of the heat dissipation fan, and the running stability of the motor can be tested under different duty cycle limitation levels, and a duty cycle compression range that can reduce board-level heat generation without causing motor instability can be selected. For example, the first compression ratio can be a smaller compression ratio to initially limit the drive output, and the second compression ratio can be a larger compression ratio than the first compression ratio to implement stronger limitations when the thermal condition deteriorates further; similarly, the first frequency correction amount and the second frequency correction amount can also be determined through... The overheat suppression test determines the specific characteristics, including drive loss, speed maintenance capability, and temperature rise changes at different drive frequencies. The correction magnitude is then selected based on the speed deviation. The first frequency correction corresponds to a milder frequency adjustment, while the second frequency correction corresponds to a larger adjustment, with the second correction being greater than the first. In actual control, when the thermal conductivity parameters fall within the first thermal suppression range, the upper limit of the PWM drive duty cycle is reduced by the first compression ratio to initially limit the drive output, while simultaneously correcting the drive frequency according to the first frequency correction. When the thermal conductivity parameters fall within the second thermal suppression range, the PWM drive duty cycle is further reduced by the second compression ratio. The upper limit is compared with the target speed, and the drive frequency is adjusted according to the second frequency correction amount to improve the thermal suppression intensity. When adjusting the drive frequency according to the speed deviation, the correction direction and correction magnitude can be determined by combining the difference between the current real-time speed and the target speed. For example, when the real-time speed is low but still within the allowable range, a small frequency correction can be maintained within the limited upper limit. When the real-time speed is high or the thermal condition continues to deteriorate, a more obvious frequency reduction method can be adopted. After completing the duty cycle upper limit limit and drive frequency correction, the controller generates a thermal suppression drive signal based on the limited PWM drive duty cycle upper limit and the corrected drive frequency, and outputs it to the drive circuit so that the motor can operate in a graded suppression manner when the thermal condition becomes tight.

[0038] In another preferred embodiment based on the above embodiments, see [reference] Figure 2 As shown, this embodiment provides a control system for a PCBA motor, including: The data acquisition module is configured to acquire temperature data of the object being cooled, real-time speed data of the PCBA motor, drive current data, PCBA board temperature data, and temperature data of the metal base plate that is attached to the PCBA board. The operating parameter determination module is configured to determine the target speed based on the temperature data of the object being cooled; determine the speed deviation based on the real-time speed data of the PCBA motor and the target speed; determine the load fluctuation parameters based on the drive current data; and determine the thermal conductivity characterization parameters based on the temperature difference between the PCBA board temperature data and the metal base plate temperature data and the rate of change of the temperature difference. The drive mode determination module is configured to determine the current heat dissipation state based on the comparison between the thermal conductivity characterization parameters and the preset thermal conductivity threshold, and to determine the target drive mode based on the speed deviation, load fluctuation parameters and the current heat dissipation state. The target drive mode includes start-up acceleration mode, steady-state speed regulation mode and thermal suppression mode. The startup acceleration control module is configured to output a startup drive signal according to the preset duty cycle climbing rule and the preset drive parameter climbing rule when the startup acceleration mode is in operation, thereby controlling the PCBA motor to accelerate to the target speed. The steady-state speed control module is configured to adjust the PWM drive duty cycle and drive parameters according to the speed deviation and load fluctuation parameters when in steady-state speed control mode, output a steady-state drive signal, and control the PCBA motor to run at the target speed. The thermal suppression control module is configured to limit the upper limit of the PWM drive duty cycle according to the thermal conductivity characterization parameters when in thermal suppression mode, and to correct the drive parameters according to the speed deviation, and output a thermal suppression drive signal to control the PCBA motor to run under limited drive conditions. The drive execution module is configured to control the windings set on the PCBA board to conduct according to the start drive signal, steady-state drive signal or thermal suppression drive signal, thereby driving the heat dissipation fan blades to rotate.

[0039] Understandably, by setting up a data acquisition module, an operating parameter determination module, a drive mode determination module, a start-up acceleration control module, a steady-state speed regulation control module, a thermal suppression control module, and a drive execution module, the temperature of the cooled object, the operating status of the PCBA motor, and the thermal state between the PCBA board and the metal base plate can be incorporated into a unified control process. The data acquisition module acquires basic operating and temperature data; the operating parameter determination module determines the target speed, speed deviation, load fluctuation parameters, and thermal conductivity parameters; and the drive mode determination module selects the corresponding target drive mode based on the heat dissipation and operating status. The control module outputs corresponding drive signals during the startup, steady-state operation, and thermal suppression phases, respectively. Finally, the drive execution module controls the windings on the PCBA board to conduct, enabling the PCBA motor to adjust accordingly according to the current operating conditions. Compared to methods that rely solely on a single parameter for start-stop or speed regulation, the above control system can employ different control strategies at different operating stages of the motor. This results in a clearer division of labor between the startup process, steady-state speed regulation process, and the restricted operation process when thermal conditions become tight. This improves the compatibility between the control process and actual heat dissipation requirements and helps to balance speed regulation and changes in board-level thermal conditions.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A control method for a PCBA motor, characterized by, include: Acquire temperature data of the object being cooled, real-time speed data of the PCBA motor, drive current data, PCBA board temperature data, and temperature data of the metal base plate that is attached to the PCBA board; The target rotational speed is determined based on the temperature data of the object being cooled. The speed deviation is determined based on the real-time speed data of the PCBA motor and the target speed, and the load fluctuation parameters are determined based on the drive current data. The thermal conductivity characterization parameters are determined based on the temperature difference between the PCBA board temperature data and the metal base plate temperature data, and the rate of change of the temperature difference. The current heat dissipation state is determined based on the comparison between the thermal conductivity characterization parameters and the preset thermal conductivity threshold, and the target driving mode is determined based on the speed deviation, the load fluctuation parameters and the current heat dissipation state. The target driving mode includes a start-up acceleration mode, a steady-state speed regulation mode and a thermal suppression mode. When in acceleration mode, a start drive signal is output according to the preset duty cycle climbing rule and the preset drive parameter climbing rule to control the PCBA motor to speed up to the target speed. When in steady-state speed regulation mode, the PWM drive duty cycle and drive parameters are adjusted according to the speed deviation and load fluctuation parameters, a steady-state drive signal is output, and the PCBA motor is controlled to run at the target speed. When in thermal suppression mode, the upper limit of the PWM drive duty cycle is limited according to the thermal conductivity characterization parameters, and the drive parameters are corrected according to the speed deviation, and a thermal suppression drive signal is output to control the PCBA motor to operate under limited drive conditions. The starting drive signal, the steady-state drive signal, or the heat suppression drive signal controls the windings on the PCBA board to conduct, thereby driving the heat dissipation fan blades to rotate.

2. The control method for PCBA motors according to claim 1, characterized in that, Determining the target rotational speed based on the temperature data of the object being cooled includes: Obtain the current temperature value and target temperature value of the object being cooled; The temperature deviation value is determined based on the current temperature value and the target temperature value; The temperature deviation values ​​of different numerical ranges are divided into a first interval, a second interval, and a third interval in ascending order of value. The upper limit of the first interval is equal to the lower limit of the second interval, and the upper limit of the second interval is equal to the lower limit of the third interval. When the temperature deviation value is greater than or equal to the lower limit of the first interval and less than the upper limit of the first interval, a first target rotational speed is determined; When the temperature deviation value is greater than or equal to the lower limit of the second interval and less than the upper limit of the second interval, the second target rotational speed is determined according to the linear mapping relationship; When the temperature deviation value is greater than or equal to the lower limit of the third interval, the third target rotational speed is determined; The first target speed, the second target speed, or the third target speed is determined as the target speed.

3. The control method for PCBA motors according to claim 2, characterized in that, When determining the load fluctuation parameters based on the drive current data, the following are included: Acquire drive current values ​​corresponding to multiple sampling moments within a continuous sampling window; The average drive current value is determined based on each of the aforementioned drive current values; The current fluctuation amplitude is determined based on the absolute value of the difference between each of the aforementioned drive current values ​​and the average drive current value. The rate of change of current is determined by the difference between the driving current values ​​at adjacent sampling times and the sampling interval. The amplitude of the current fluctuation and the rate of change of the current are normalized. The load fluctuation parameters are obtained by weighting the normalized current fluctuation amplitude and the normalized current change rate.

4. The control method for PCBA motor according to claim 3, characterized in that, When determining the thermal conductivity characterization parameters based on the temperature difference between the PCBA board temperature data and the metal substrate temperature data, and the rate of change of the temperature difference, the following are included: The temperature difference between the bottom of the board is determined based on the temperature data of the PCBA board and the temperature data of the metal base plate. The rate of change of temperature difference is determined based on the difference in temperature difference at the bottom of the plate between adjacent control cycles and the duration of the control cycle. The temperature difference at the bottom of the plate and the rate of change of the temperature difference are normalized. The normalized temperature difference at the bottom of the plate and the normalized rate of change of temperature difference are calculated according to the weighted fusion relationship to obtain the thermal conductivity characterization parameters.

5. The control method for PCBA motor according to claim 4, characterized in that, When determining the current heat dissipation state based on the comparison result between the thermal conductivity characterization parameters and the preset thermal conductivity threshold, the following steps are included: Based on the range of values ​​of the thermal conductivity characterization parameters, the normal heat dissipation range, the warning heat dissipation range, and the limited heat dissipation range are divided in ascending order of value. The maximum value of the normal heat dissipation range is less than the minimum value of the warning heat dissipation range, and the maximum value of the warning heat dissipation range is less than the minimum value of the limited heat dissipation range. When the thermal conductivity characterization parameters fall within the normal heat dissipation range, the current heat dissipation state is determined to be the normal heat dissipation state. When the thermal conductivity characterization parameter falls into the warning heat dissipation range, the current heat dissipation state is determined to be the warning heat dissipation state; When the thermal conductivity characterization parameters fall within the limited heat dissipation range, the current heat dissipation state is determined to be a limited heat dissipation state.

6. The control method for PCBA motor according to claim 5, characterized in that, When determining the target drive mode based on the speed deviation, the load fluctuation parameters, and the current heat dissipation status, the following are included: The starting speed range and the running speed range are divided according to the value range of the real-time speed in ascending order. The upper limit of the starting speed range is less than the lower limit of the running speed range. Based on the value range of the load fluctuation parameter, the stable fluctuation range and the enhanced fluctuation range are divided in ascending order of value. The upper limit of the stable fluctuation range is less than the lower limit of the enhanced fluctuation range. When the real-time rotational speed falls into the starting speed range, the target drive mode is determined to be the start-up acceleration mode; When the real-time speed falls within the operating speed range, the load fluctuation parameter falls within the stable fluctuation range, and the current heat dissipation state is a normal heat dissipation state or a warning heat dissipation state, the target drive mode is determined to be a steady-state speed regulation mode. When the current heat dissipation state is a limited heat dissipation state, the target driving mode is determined to be a thermal suppression mode; When the current heat dissipation state is a warning heat dissipation state and the load fluctuation parameter falls into the enhanced fluctuation range, the target driving mode is determined to be the heat suppression mode.

7. The control method for PCBA motors according to claim 6, characterized in that, When in acceleration mode, the startup drive signal is output according to the preset duty cycle ramp-up rule and the preset drive parameter ramp-up rule, including: Set the initial duty cycle and initial drive frequency at startup; The range of the rotational speed deviation is divided into a large deviation range and a small deviation range in descending order of value, wherein the lower limit of the large deviation range is greater than the upper limit of the small deviation range. When the speed deviation falls into the large deviation range, the PWM drive duty cycle is increased according to the first ramp slope, and the drive frequency is adjusted according to the first frequency ramp amount. When the speed deviation falls into the small deviation range, the PWM drive duty cycle is increased according to the second ramp slope, and the drive frequency is adjusted according to the second frequency ramp amount. The first ramp slope is greater than the second ramp slope, and the first frequency ramp amount is greater than the second frequency ramp amount. The start-up drive signal is output based on the improved PWM drive duty cycle and the adjusted drive frequency.

8. The control method for PCBA motor according to claim 7, characterized in that, In steady-state speed control mode, when adjusting the PWM drive duty cycle and drive parameters according to the speed deviation and load fluctuation parameters, the following steps are included: Obtain the absolute value of the speed deviation; Based on the range of the absolute value of the speed deviation, the speed regulation dead zone and the speed regulation correction interval are divided in ascending order of value. The maximum value of the speed regulation dead zone is less than the minimum value of the speed regulation correction interval. When the absolute value of the speed deviation falls into the speed regulation dead zone and the load fluctuation parameter falls into the stable fluctuation range, the current PWM drive duty cycle and the current drive parameter remain unchanged. When the absolute value of the speed deviation falls into the speed regulation correction range and the load fluctuation parameter falls into the stable fluctuation range, the PWM drive duty cycle and drive parameters are increased when the real-time speed is lower than the target speed, and the PWM drive duty cycle and drive parameters are decreased when the real-time speed is higher than the target speed. When the load fluctuation parameters fall into the enhanced fluctuation range, the PWM drive duty cycle and drive parameters are adjusted according to the gradual slope.

9. The control method for a PCBA motor according to claim 8, characterized in that, When in thermal suppression mode, limiting the upper limit of the PWM drive duty cycle based on the thermal conductivity characterization parameters and correcting the drive parameters based on the speed deviation includes: Based on the range of values ​​of the thermal conductivity characterization parameters, the first thermal suppression interval and the second thermal suppression interval are divided in ascending order of value. The upper limit of the first thermal suppression interval is less than the lower limit of the second thermal suppression interval. When the thermal conductivity characterization parameters fall into the first thermal suppression range, the upper limit of the PWM drive duty cycle is reduced according to the first compression ratio, and the drive frequency is corrected according to the first frequency correction amount. When the thermal conductivity characterization parameter falls into the second thermal suppression range, the upper limit of the PWM drive duty cycle is reduced according to the second compression ratio, and the drive frequency is corrected according to the second frequency correction amount. The second compression ratio is greater than the first compression ratio, and the second frequency correction amount is greater than the first frequency correction amount. The thermal suppression drive signal is output based on the upper limit of the restricted PWM drive duty cycle and the corrected drive frequency.

10. A control system for a PCBA motor, used to implement the control method for a PCBA motor as described in any one of claims 1-9, characterized in that, include: The data acquisition module is configured to acquire temperature data of the object being cooled, real-time speed data of the PCBA motor, drive current data, PCBA board temperature data, and temperature data of the metal base plate that is attached to the PCBA board. The operating parameter determination module is configured to determine the target speed based on the temperature data of the object being cooled; determine the speed deviation based on the real-time speed data of the PCBA motor and the target speed; and determine the load fluctuation parameters based on the drive current data. The thermal conductivity characterization parameters are determined based on the temperature difference between the PCBA board temperature data and the metal base plate temperature data, as well as the rate of change of the temperature difference. The drive mode determination module is configured to determine the current heat dissipation state based on the comparison between the thermal conductivity characterization parameters and the preset thermal conductivity threshold, and to determine the target drive mode based on the speed deviation, load fluctuation parameters and the current heat dissipation state. The target drive mode includes start-up acceleration mode, steady-state speed regulation mode and thermal suppression mode. The startup acceleration control module is configured to output a startup drive signal according to the preset duty cycle climbing rule and the preset drive parameter climbing rule when the startup acceleration mode is in operation, thereby controlling the PCBA motor to accelerate to the target speed. The steady-state speed control module is configured to adjust the PWM drive duty cycle and drive parameters according to the speed deviation and load fluctuation parameters when in steady-state speed control mode, output a steady-state drive signal, and control the PCBA motor to run at the target speed. The thermal suppression control module is configured to limit the upper limit of the PWM drive duty cycle according to the thermal conductivity characterization parameters when in thermal suppression mode, and to correct the drive parameters according to the speed deviation, and output a thermal suppression drive signal to control the PCBA motor to run under limited drive conditions. The drive execution module is configured to control the windings set on the PCBA board to conduct according to the start drive signal, steady-state drive signal or thermal suppression drive signal, thereby driving the heat dissipation fan blades to rotate.

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