Fault identification method of direct-current fan control system and direct-current fan control system

Abstract

The invention relates to a fault identification method of a direct-current fan control system and the direct-current fan control system, and relates to the technical field of fan control. The method comprises the steps that a direct current fan driving controller sends a PWM recognition request signal to a main controller; wherein the PWM identification request signal is generated based on a preset PWM duty ratio and a preset PWM frequency; after the main controller receives the PWM identification request signal, a PWM identification confirmation signal is generated based on the PWM identification request signal, and the PWM identification confirmation signal is sent to the direct current fan driving controller; and after receiving the PWM identification confirmation signal, the direct current fan driving controller obtains a confirmation PWM frequency based on the PWM identification confirmation signal, compares the confirmation PWM frequency with a preset PWM frequency, and determines whether a fault occurs according to a comparison result. Whether a communication fault exists between the main controller and the direct-current fan driving controller or not can be determined according to the comparison result.

Description

Technical Field

[0001] The present application relates to the field of fan control technology, and in particular to a fault identification method for a DC fan control system and a DC fan control system. Background Art

[0002] With the development of fan technology, DC fans have been widely used in many fields due to their advantages such as high efficiency, energy saving, good speed regulation, high control precision, and low noise. When used in gas water heaters, DC fans demonstrate significant advantages in wind resistance, energy saving, thermal efficiency, operational stability, noise control, and intelligent user experience. Currently, due to different design solutions from different suppliers, the DC fans in gas water heaters generally correspond to different fan speeds corresponding to the PWM (Pulse Width Modulation) duty cycle of the control signal. This results in different air distribution programs corresponding to different control gears of the gas water heater. Therefore, when the same gas water heater is equipped with DC fans of different brands, the air distribution data of the different brands of DC fans must be matched for normal operation.

[0003] The existing pairing mechanism is that when the gas water heater is powered on, the DC fan drive controller sends a corresponding identification frequency signal (a signal with a fixed PWM duty cycle and PWM frequency) to the gas water heater's main controller. Once the main controller recognizes the corresponding identification frequency signal, it selects the corresponding air distribution program to operate, thereby ensuring the normal operation of the gas water heater. However, with this method, if the identification signal line terminal has poor contact or there is external interference, the main controller will recognize the incorrect frequency signal, resulting in a poor user experience or even malfunction of the gas water heater. Summary of the Invention

[0004] Based on this, it is necessary to provide a fault identification method and a DC fan control system for the DC fan control system that can identify such faults in order to solve the above technical problems.

[0005] In the first aspect, the present application provides a fault identification method for a DC fan control system. The DC fan control system includes: a main controller and a DC fan drive controller, and the method includes: the DC fan drive controller sends a PWM identification request signal to the main controller; wherein the PWM identification request signal is generated based on a preset PWM duty cycle and a preset PWM frequency; after the main controller receives the PWM identification request signal, it generates a PWM identification confirmation signal based on the PWM identification request signal, and sends the PWM identification confirmation signal to the DC fan drive controller; after the DC fan drive controller receives the PWM identification confirmation signal, it obtains a confirmed PWM frequency based on the PWM identification confirmation signal, compares the confirmed PWM frequency with the preset PWM frequency, and determines whether there is a fault based on the comparison result.

[0006] In the fault identification method for the DC fan control system described above, the DC fan drive controller first sends a PWM identification request signal to the main controller. After receiving the PWM identification request signal, the main controller generates a PWM identification confirmation signal based on the PWM identification request signal and sends the PWM identification confirmation signal to the DC fan drive controller. During this signal transmission process, if the DC fan drive controller and the main controller experience poor contact or are subject to environmental interference, the PWM identification request signal received by the main controller or the PWM identification confirmation signal sent by the main controller will be abnormal. After receiving the PWM identification confirmation signal, the DC fan drive controller determines the confirmed PWM frequency based on the PWM identification confirmation signal and compares the confirmed PWM frequency with the preset PWM frequency. Based on the comparison result, it can be determined whether such a communication fault exists.

[0007] In one embodiment, the step of determining whether a fault occurs based on the comparison result includes: if the comparison result is that the confirmed PWM frequency is the same as the preset PWM frequency, determining that there is no fault and controlling the DC fan to start; if the comparison result is that the confirmed PWM frequency is different from the preset PWM frequency, determining a communication fault and sending an identification error signal to the main controller.

[0008] In one embodiment, after the step of sending the identification error signal to the main controller, the method further includes: after the main controller receives the identification error signal, generating an identification error fault code based on the identification error signal, and sending the identification error fault code to the display for display.

[0009] In one embodiment, the step of generating a PWM identification confirmation signal based on the PWM identification request signal includes: setting the PWM frequency of the PWM identification confirmation signal to be the same as the PWM frequency of the received PWM identification request signal, and setting the PWM duty cycle of the PWM identification confirmation signal to a confirmed PWM duty cycle; wherein the confirmed PWM duty cycle is less than the minimum duty cycle for starting the DC fan.

[0010] In a second aspect, the present application also provides a fault identification method for a DC fan control system. The DC fan control system includes: a main controller and a DC fan drive controller, and the method includes: after the main controller obtains the current fan model and the current air distribution gear, it determines the PWM control signal based on the current fan model and the current air distribution gear, and sends the PWM control signal to the DC fan drive controller; after the DC fan drive controller receives the PWM control signal, it matches the PWM duty cycle and PWM frequency of the PWM control signal in the preset air distribution data, and determines whether the main controller identifies the model error based on the matching result; wherein, the preset air distribution data at least includes the correspondence between multiple air distribution gears under the fan model itself and the preset PWM frequency and preset PWM duty cycle.

[0011] In the fault identification method for the DC fan control system described above, after the main controller obtains the current fan model and current air distribution level, it determines the corresponding PWM control signal based on the current fan model and current air distribution level, and sends the PWM control signal to the DC fan drive controller. If the DC fan drive controller and the main controller have poor contact or are subject to environmental interference, the PWM control signal received by the DC fan drive controller will be abnormal. The PWM duty cycle and PWM frequency of the received PWM control signal are matched against the preset air distribution data, and the matching result can be used to determine whether such a communication failure exists.

[0012] In one embodiment, the step of determining the PWM control signal based on the current fan model and the current air distribution gear includes: determining the PWM frequency of the PWM control signal based on the current air distribution gear, and determining the PWM duty cycle of the PWM control signal based on the current air distribution gear and the current fan model;

[0013] The step of matching the PWM duty cycle and PWM frequency based on the PWM control signal in the preset air distribution data, and determining whether the main controller recognizes the model error based on the matching result, includes: determining the current air distribution gear based on the matching result of the PWM frequency of the PWM control signal and the preset PWM frequency; determining the preset PWM duty cycle based on the current air distribution gear; and determining whether the main controller recognizes the model error based on the matching result of the PWM duty cycle of the PWM control signal and the preset PWM duty cycle.

[0014] In one embodiment, the step of determining whether the main controller has identified the wrong model based on the matching result of the PWM duty cycle of the PWM control signal and the preset PWM duty cycle includes: if the PWM duty cycle of the PWM control signal is the same as the preset PWM duty cycle, determining that the main controller has identified the model correctly; if the PWM duty cycle of the PWM control signal is different from the preset PWM duty cycle, determining that the main controller has identified the wrong model.

[0015] In one embodiment, after the step of determining that the main controller has identified an incorrect fan model, the method further includes: the DC fan drive controller sending the current fan current to the main controller; the main controller updating the PWM duty cycle of the PWM control signal based on the current fan current and the target fan current; wherein the target fan current is determined by the current air distribution gear;

[0016] The step of updating the PWM duty cycle of the PWM control signal based on the current fan current and the target fan current includes: if the current fan current is greater than the target fan current, reducing the PWM duty cycle of the PWM control signal; if the current fan current is less than the target fan current, increasing the PWM duty cycle of the PWM control signal.

[0017] In one embodiment, the method further includes: updating the PWM duty cycle of the PWM control signal based on the current fan current and the target fan current until the current fan current is the same as the target fan current, and then re-determining the current fan model based on the PWM duty cycle of the updated PWM control signal; if the main controller updates the PWM duty cycle of the PWM control signal and cannot make the current fan current the same as the target fan current, stopping the DC fan operation, generating an identification error fault code, and sending the identification error fault code to the display for display.

[0018] In a third aspect, the present application further provides a DC fan control system, which includes a main controller and a DC fan drive controller, and is configured to execute the steps of the above-mentioned fault identification method. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of a DC fan control system in one embodiment;

[0020] Figure 2 1 is a flow chart of a fault identification method according to an embodiment;

[0021] Figure 3 is a flow chart of a fault identification method in another embodiment;

[0022] Figure 4 Schematic diagram of a process for determining whether a fault occurs based on a matching result in one embodiment;

[0023] Figure 5 Schematic diagram of a flow chart of a fault identification method in yet another embodiment. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0025] The fault identification method of the DC fan control system provided in the embodiment of the present application can be applied to the DC fan control system. The DC fan control system can be applied to equipment systems that require air supply, such as gas water heaters, equipment cooling systems, ventilation systems, etc. The DC fan control system includes: a main controller and a DC fan drive controller. Figure 1 As shown in the figure, taking the main controller of a gas water heater as an example, the main controller includes a main control chip and a fan current sampling circuit. The DC fan drive controller is equipped with a DC fan drive circuit. The main control chip sends a PWM signal to the DC fan drive controller via a PWM control line to control the speed of the three-wire DC fan load. The DC fan drive controller feeds back a speed signal or other preset signal to the main control chip via an FG (Frequency Generator) signal line. The fan current sampling circuit is connected to the DC fan drive controller to collect the current current of the three-wire DC fan load.

[0026] In one embodiment, Figure 2 As shown, a fault identification method is provided, which is applied to Figure 1 The DC fan control system in the example is used to illustrate the following steps:

[0027] In step S110 , the DC fan drive controller sends a PWM identification request signal to the main controller.

[0028] Specifically, after the DC fan control system is powered on and started, the DC fan drive controller first sends a PWM identification request signal to the main controller through the FG signal line. The PWM identification request signal is generated based on the preset PWM duty cycle and the preset PWM frequency. It can be understood that the DC fan drive controller and the DC fan are matched, and their brands and manufacturers are the same. For DC fan drive controllers of different brands, the PWM identification request signals generated by the preset PWM duty cycle and the preset PWM frequency are different. For example, the preset PWM duty cycle of manufacturer A is set to 18%, and the preset PWM frequency is set to 1kHz; the preset PWM duty cycle of manufacturer B is set to 45.7%, and the preset PWM frequency is set to 4kHz. Therefore, the PWM duty cycle and PWM frequency of the generated PWM identification request signal are also different.

[0029] In step S120 , after receiving the PWM identification request signal, the main controller generates a PWM identification confirmation signal based on the PWM identification request signal, and sends the PWM identification confirmation signal to the DC fan drive controller.

[0030] Specifically, after receiving a PWM identification request signal from the DC fan drive controller via the FG signal line, the main controller generates a PWM identification confirmation signal based on the PWM identification request signal and transmits the PWM identification confirmation signal to the DC fan drive controller via the PWM control line. In some embodiments, the main controller sets the PWM frequency of the PWM identification confirmation signal to be the same as the PWM frequency of the received PWM identification request signal and sets the PWM duty cycle of the PWM identification confirmation signal to the confirmed PWM duty cycle; wherein the confirmed PWM duty cycle is less than the minimum duty cycle for starting the DC fan to prevent the transmitted PWM identification confirmation signal from starting the fan. In some other embodiments, the main controller may also obtain a corresponding PWM identification confirmation signal by matching the received PWM identification request signal according to a preset matching table. It is understood that because the FG signal line between the DC fan drive controller and the main controller may have poor contact or be subject to environmental interference, the PWM identification request signal received by the main controller may differ from the PWM identification request signal sent by the DC fan drive controller.

[0031] In step S130 , after receiving the PWM identification confirmation signal, the DC fan drive controller obtains a confirmed PWM frequency based on the PWM identification confirmation signal, compares the confirmed PWM frequency with a preset PWM frequency, and determines whether a fault occurs based on the comparison result.

[0032] Specifically, after the DC fan drive controller receives the PWM identification confirmation signal through the PWM control line, it obtains the confirmed PWM frequency according to the PWM identification confirmation signal. In some embodiments, the confirmed PWM frequency is the same as the PWM frequency of the PWM identification confirmation signal. In some other embodiments, the PWM frequency of the PWM identification confirmation signal can also be processed so that the obtained confirmed PWM frequency is different from the PWM frequency of the PWM identification confirmation signal. After obtaining the confirmed PWM frequency, the confirmed PWM frequency is compared with the preset PWM frequency to obtain a comparison result, and it is determined whether a fault exists based on the comparison result. It can be understood that the comparison results obtained after comparing the confirmed PWM frequency obtained by different methods with the preset PWM frequency are also different, and the corresponding fault states are also different.

[0033] In the fault identification method for the DC fan control system described above, the DC fan drive controller first sends a PWM identification request signal to the main controller. After receiving the PWM identification request signal, the main controller generates a PWM identification confirmation signal based on the PWM identification request signal and sends the PWM identification confirmation signal to the DC fan drive controller. During this signal transmission process, if the DC fan drive controller and the main controller experience poor contact or are subject to environmental interference, the PWM identification request signal received by the main controller or the PWM identification confirmation signal sent by the main controller will be abnormal. After receiving the PWM identification confirmation signal, the DC fan drive controller determines the confirmed PWM frequency based on the PWM identification confirmation signal and compares the confirmed PWM frequency with the preset PWM frequency. Based on the comparison result, it can be determined whether such a communication fault exists.

[0034] In one embodiment, in step S130 , the step of determining whether there is a fault according to the comparison result includes: if the comparison result confirms that the PWM frequency is the same as the preset PWM frequency, then determining that there is no fault, and controlling the DC fan to start.

[0035] Specifically, in this embodiment, the PWM identification confirmation signal is set to have the same PWM duty cycle and PWM frequency as the PWM identification request signal, and the PWM frequency is confirmed to be the same as the PWM frequency of the PWM identification confirmation signal. If the comparison result confirms that the PWM frequency is the same as the preset PWM frequency, it indicates that the PWM frequency of the PWM identification request signal received by the main controller and the PWM identification confirmation signal sent by the main controller have not changed. At this point, the DC fan drive controller is communicating well with the main controller, the DC fan control system is determined to be fault-free, and the DC fan can be controlled to start. In some other embodiments, a frequency error range can also be set. If the error between the PWM frequency and the preset PWM frequency is confirmed to be within the frequency error range, it can also be determined that there is no fault.

[0036] In one embodiment, in step S130 , the step of determining whether a fault occurs according to the comparison result includes: if the comparison result confirms that the PWM frequency is different from the preset PWM frequency, determining that a communication fault occurs, and sending an identification error signal to the main controller.

[0037] Specifically, in this embodiment, the PWM identification confirmation signal is set to be the same as the PWM duty cycle and PWM frequency of the PWM identification request signal, and the PWM frequency is confirmed to be the same as the PWM frequency of the PWM identification confirmation signal. If the comparison result is that the PWM frequency is confirmed to be different from the preset PWM frequency, it means that the PWM frequency of the PWM identification request signal received by the main controller through the FG signal line or the PWM identification confirmation signal sent through the PWM control line has changed during the communication process. At this time, it is determined that a communication failure has occurred between the DC fan drive controller and the main controller, and the DC fan drive controller sends an identification error signal to the main controller to prompt the occurrence of a communication failure. In some embodiments, the identification error signal is also a PWM signal, and its PWM duty cycle and PWM frequency can be preset. In some other embodiments, a frequency error range can also be set. If the error between the confirmed PWM frequency and the preset PWM frequency exceeds the frequency error range, it is determined that a communication failure has occurred.

[0038] In one embodiment, after the step of sending the identification error signal to the main controller, the fault identification method further includes: after the main controller receives the identification error signal, generating an identification error fault code based on the identification error signal, and sending the identification error fault code to the display for display.

[0039] Specifically, after receiving the identification error signal, the main controller analyzes the PWM duty cycle and PWM frequency of the identification error signal to match the corresponding identification error fault code. After determining the identification error fault code, the main controller sends the identification error fault code to the display for display. For example, after receiving the identification error fault code, the display may display "SE" to indicate a communication failure, prompting the customer to perform repairs.

[0040] In one embodiment, Figure 3 As shown, the present application also provides a fault identification method, which is applied to Figure 1 The DC fan control system in the example is used to illustrate the following steps:

[0041] In step S210 , after obtaining the current fan model and the current air distribution gear, the main controller determines a PWM control signal based on the current fan model and the current air distribution gear, and sends the PWM control signal to the DC fan drive controller.

[0042] Specifically, when the DC fan control system controls the DC fan to start running, the DC fan control system will operate at a certain initial air distribution gear. It is understandable that different air distribution gears correspond to different fan currents, and different fan models require different PWM control signal PWM duty cycles and PWM frequencies at the same air distribution gear (fan current). During operation, the main controller first obtains the current fan model and the current air distribution gear, and then matches the current fan model and the current air distribution gear in the preset matching table to determine the corresponding PWM control signal PWM duty cycle and PWM frequency. The preset matching table includes the PWM duty cycle and PWM frequency of the corresponding PWM control signal under a variety of fan models and a variety of air distribution gears.

[0043] The following table shows the corresponding relationship between PWM frequency and PWM duty cycle of different fan models at different air distribution gears in one embodiment:

[0044]

[0045] After the main controller determines the PWM control signal, it sends it to the DC fan drive controller via the PWM control line. For example, if the fan model is from manufacturer B and the current air flow level is 5 (corresponding to a fan current of 280mA), the PWM control signal has a 48.5% duty cycle and a 5kHz frequency.

[0046] In step S220, after receiving the PWM control signal, the DC fan drive controller matches the PWM duty cycle and PWM frequency of the PWM control signal with the preset air distribution data, and determines whether the main controller identifies the wrong model based on the matching result.

[0047] Specifically, after receiving a PWM control signal via the PWM control line, the DC fan drive controller matches the PWM duty cycle and PWM frequency of the PWM control signal against preset air distribution data. The preset air distribution data includes at least the correspondence between various air distribution levels for the fan model, the preset PWM frequency, and the preset PWM duty cycle. Specifically, the preset air distribution data may include only the correspondence between various air distribution levels for the fan model, the preset PWM frequency, and the preset PWM duty cycle, or it may include the correspondence between various air distribution levels for multiple fan models, the preset PWM frequency, and the preset PWM duty cycle. It is understood that when the preset air distribution data includes the correspondence between various air distribution levels for multiple fan models, the preset PWM frequency, and the preset PWM duty cycle, the DC fan drive controller can determine the currently used fan model and, when performing the match, only performs the match for the current fan model. If the DC fan drive controller successfully matches, it indicates that the main controller has not identified the model incorrectly. If the DC fan drive controller fails to match, it indicates that the main controller has identified the model incorrectly. It is understandable that when determining whether the machine model is incorrectly identified, the communication failure between the main controller and the DC fan drive controller has been ruled out.

[0048] In some embodiments, by executing steps S110 to S130 and confirming that there is no communication failure between the main controller and the DC fan drive controller, steps S210 and S220 can be performed to determine whether the main controller has an identification model error based on the matching results.

[0049] In one embodiment, in step S210, the step of determining the PWM control signal based on the current fan model and the current air distribution gear includes: determining the PWM frequency of the PWM control signal based on the current air distribution gear, and determining the PWM duty cycle of the PWM control signal based on the current air distribution gear and the current fan model.

[0050] Specifically, in this embodiment, the PWM frequency of the PWM control signal is solely dependent on the air distribution level. When determining the PWM control signal, the main controller first determines the PWM frequency of the PWM control signal based on the current air distribution level. It then determines the PWM duty cycle of the PWM control signal based on the current air distribution level and the current fan model. For example, if the current fan model is manufacturer B and the current air distribution level is level 5 (corresponding to a fan current of 280mA), the PWM frequency of the PWM control signal can be determined to be 5kHz based solely on the current air distribution level. Furthermore, the PWM duty cycle of the PWM control signal, determined based on the current air distribution level and the current fan model, is 48.5%.

[0051] In one embodiment, Figure 4As shown, in step S220, the PWM duty cycle and PWM frequency based on the PWM control signal are matched in the preset air distribution data, and the main controller is determined to have identified the wrong model according to the matching result, including:

[0052] Step S221 : determining the current air distribution gear position based on a matching result between the PWM frequency of the PWM control signal and a preset PWM frequency.

[0053] Specifically, after receiving the PWM control signal, the DC fan drive controller first determines the current air distribution level based on the matching result between the PWM control signal's PWM frequency and the preset PWM frequency. For example, if the DC fan drive controller's own fan model is from Manufacturer B, the preset air distribution data only includes the correspondence between Manufacturer B's various air distribution levels, the preset PWM frequency, and the preset PWM duty cycle. If the PWM control signal's PWM frequency matches the preset PWM frequency for level 5, the current air distribution level is determined to be level 5.

[0054] Step S222: determining a preset PWM duty cycle based on the current air distribution gear position.

[0055] Specifically, after the DC fan drive controller determines the current air distribution level, it then determines the corresponding preset PWM duty cycle based on the current air distribution level. For example, if the DC fan drive controller's fan model is from manufacturer B and the current air distribution level is level 5, the preset PWM duty cycle is 48.5%.

[0056] Step S223 : determining whether the main controller identifies a wrong model based on a matching result between the PWM duty cycle of the PWM control signal and a preset PWM duty cycle.

[0057] Specifically, after the DC fan drive controller determines the preset PWM duty cycle, it matches the PWM duty cycle of the PWM control signal with the preset PWM duty cycle and obtains a matching result. Finally, it determines whether the main controller recognizes the model error based on the matching result.

[0058] In one embodiment, in step S223, the step of determining whether the main controller has identified the wrong model based on the matching result of the PWM duty cycle of the PWM control signal and the preset PWM duty cycle includes: if the PWM duty cycle of the PWM control signal is the same as the preset PWM duty cycle, determining that the main controller has identified the model correctly.

[0059] Specifically, if the matching result of the PWM duty cycle of the PWM control signal and the preset PWM duty cycle is: the PWM duty cycle of the PWM control signal is the same as the preset PWM duty cycle, then it means that the PWM control signal sent by the main controller is correct, and the main controller correctly identifies the current fan model of the DC fan drive controller.

[0060] In one embodiment, in step S223, the step of determining whether the main controller identifies a model error based on the matching result of the PWM duty cycle of the PWM control signal and the preset PWM duty cycle includes: if the PWM duty cycle of the PWM control signal is different from the preset PWM duty cycle, determining that the main controller identifies a model error.

[0061] Specifically, if the matching result of the PWM duty cycle of the PWM control signal and the preset PWM duty cycle is: the PWM duty cycle of the PWM control signal is different from the preset PWM duty cycle, it means that the PWM control signal sent by the main controller is incorrect, and the main controller incorrectly identifies the current fan model of the DC fan drive controller.

[0062] For a specific example, when the DC fan drive controller's own fan model is manufacturer B and the preset PWM duty cycle is determined to be 48.5%, if the PWM duty cycle of the PWM control signal is also 48.5%, it means that the PWM control signal sent by the main controller is correct and the main controller has correctly identified the model; if the PWM duty cycle of the PWM control signal is not 48.5%, it means that the PWM control signal sent by the main controller is incorrect and the main controller has incorrectly identified the model.

[0063] In one embodiment, Figure 5 As shown, after the step of determining that the main controller identifies the wrong model, the fault identification method further includes:

[0064] In step S224 , the DC fan drive controller sends the current fan current to the main controller.

[0065] Specifically, when there is a model identification error in the DC fan control system, it means that the PWM duty cycle or PWM frequency of the PWM control signal sent by the main controller does not match the current fan model. At this time, the DC fan will still operate under the control of the wrong PWM control signal, but the fan current and speed during its operation will be too large or too small. For example, if the fan model of the DC fan drive controller is manufacturer A, and the received PWM control signal is a 48.5% PWM duty cycle of manufacturer B at the 5th wind gear, then it is larger than the 26.3% PWM duty cycle of manufacturer A at the 5th wind gear. At this time, the DC fan operating current is large, and the corresponding DC fan speed will also be too large. Therefore, after determining that there is a model identification error, the DC fan drive controller of this embodiment sends the detected current fan current to the main controller, that is, the main controller can collect the current fan current through the fan current sampling circuit.

[0066] In step S225 , the main controller updates the PWM duty cycle of the PWM control signal based on the current wind turbine current and the target wind turbine current.

[0067] Specifically, after the main controller receives the current fan current sent by the DC fan drive controller, it obtains the target fan current, which is determined by the current air distribution gear. Then the PWM duty cycle of the PWM control signal is updated according to the current fan current and the target fan current. In some embodiments, when the current fan current and the target fan current are updated to be the same, the PWM duty cycle of the PWM control signal is stopped from being updated. In some other embodiments, the current fan current may not be able to reach the target fan current. In this case, when the current fan current and the target fan current are closest, the PWM duty cycle of the PWM control signal can be stopped from being updated. In this way, even if there is a model recognition error in the DC fan control system, the speed and fan current of the DC fan can still be adjusted by adjusting the PWM duty cycle of the PWM control signal to ensure that the speed of the DC fan is most consistent with the current air distribution gear.

[0068] In one embodiment, in step S225, the step of updating the PWM duty cycle of the PWM control signal based on the current fan current and the target fan current includes: if the current fan current is greater than the target fan current, reducing the PWM duty cycle of the PWM control signal; if the current fan current is less than the target fan current, increasing the PWM duty cycle of the PWM control signal.

[0069] Specifically, if the main controller detects that the current fan current is greater than the target fan current, the PWM duty cycle of the PWM control signal may be gradually reduced to reduce the current fan current until the update stops. If the main controller detects that the current fan current is less than the target fan current, the PWM duty cycle of the PWM control signal may be gradually increased to increase the current fan current until the update stops. In some embodiments, when reducing or increasing the PWM duty cycle of the PWM control signal, the amount of each reduction or increase in the PWM duty cycle may be adjusted based on the degree of difference between the current fan current and the target fan current.

[0070] For example, the current fan model obtained by the main controller is manufacturer B, and the current air distribution gear is gear 5. Therefore, the PWM duty cycle of the PWM control signal sent by the main controller is 48.5%, and the PWM frequency is 5kHz. The fan model of the DC fan drive controller itself is manufacturer A. Under the control of this PWM control signal, the fan speed of the DC fan will be too high. The current fan current collected is 500mA. The target fan current determined by the main controller based on the current air distribution gear 5 is 280mA. Therefore, the main controller will gradually reduce the PWM duty cycle of the PWM control signal and compare it with the updated current fan current in real time. When the current fan current is the same as or closest to the target fan current, the main controller stops adjusting the PWM duty cycle of the PWM control signal.

[0071] In one embodiment, the fault identification method further includes: updating the PWM duty cycle of the PWM control signal based on the current fan current and the target fan current until the current fan current and the target fan current are the same, and then re-determining the current fan model based on the PWM duty cycle of the updated PWM control signal.

[0072] Specifically, in this embodiment, the main controller updates the PWM duty cycle of the PWM control signal based on the current fan current and the target fan current until the current fan current and the target fan current are equal. It then re-determines the current fan model based on the updated PWM duty cycle of the PWM control signal. During subsequent use, the main controller can output the correct PWM control signal based on the re-determined current fan model, automatically completing fan model calibration without requiring manual adjustment by the user.

[0073] For example, the main controller determines that the current fan model is manufacturer B and the current air distribution level is 5. Therefore, the PWM control signal sent by the main controller has a PWM duty cycle of 48.5% and a PWM frequency of 5 kHz. However, the DC fan drive controller's own fan model is manufacturer A. Under the control of this PWM control signal, the DC fan's fan speed will be too high. The current fan current collected is 500 mA. The main controller determines the target fan current to be 280 mA based on the current air distribution level 5. Therefore, the main controller gradually reduces the PWM duty cycle of the PWM control signal and compares it with the updated current fan current in real time. When the current fan current and the target fan current are the same, the main controller stops adjusting the PWM duty cycle of the PWM control signal. At this point, the updated PWM duty cycle of the PWM control signal is 26.3%. By matching the current fan current within the 5 air distribution levels, the main controller determines that the preset parameters of manufacturer A meet the requirements. Therefore, the main controller adjusts the current fan model to manufacturer A, completing the fan model calibration.

[0074] In one embodiment, the fault identification method also includes: if the main controller updates the PWM duty cycle of the PWM control signal and cannot make the current fan current the same as the target fan current, the DC fan is stopped, and an identification error fault code is generated, and the identification error fault code is sent to the display for display.

[0075] Specifically, in this embodiment, when the main controller updates the PWM duty cycle of the PWM control signal, it only updates according to the PWM control signal under the preset air distribution gear. If the PWM control signal under the corresponding air distribution gear cannot make the current fan current the same as the target fan current, it means that there is a problem with the signal recognition of the main controller. For example, the main controller stores PWM control signals from three different manufacturers under one air distribution gear. When updating the PWM duty cycle, it sets them to the corresponding PWM duty cycle in turn. If none of them can make the current fan current the same as the target fan current, it means that there is a problem with the signal recognition (for example, the frequency signal can be received, but the duty cycle value cannot be identified). In this case, the DC fan is stopped, the main controller generates an identification error fault code, and sends the identification error fault code to the display for display, prompting the user to perform maintenance.

[0076] It should be understood that, although the various steps in the flowcharts involved in the various embodiments described above are displayed in sequence according to the instructions of the arrows, these steps are not necessarily executed in sequence in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and these steps can be executed in other orders. Moreover, at least a portion of the steps in the flowcharts involved in the various embodiments described above can include multiple steps or multiple stages, and these steps or stages are not necessarily executed and completed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a portion of steps or stages in other steps.

[0077] Based on the same inventive concept, embodiments of the present application also provide a DC fan control system for implementing the aforementioned fault identification method. The solution provided by this DC fan control system is similar to the solution described in the aforementioned method. Therefore, the specific limitations of one or more DC fan control system embodiments provided below can be found in the limitations of the fault identification method described above and will not be further elaborated here.

[0078] In one embodiment, Figure 1 As shown, a DC fan control system is provided, including: a main controller and a DC fan drive controller, and the DC fan control system is used to execute the steps of the fault identification method in the above embodiment.

[0079] Those skilled in the art will appreciate that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the above-mentioned embodiments. In particular, any reference to memory, database, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The databases involved in the various embodiments provided herein may include at least one of a relational database and a non-relational database. Non-relational databases may include, but are not limited to, distributed databases based on blockchains. The processors involved in the various embodiments provided herein may be, but are not limited to, general-purpose processors, central processing units (CPUs), graphics processing units (GPUs), digital signal processors (DSPs), programmable logic devices (PLDs), data processing logic devices based on quantum computing, and the like.

[0080] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0081] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

Claims

1. A fault identification method for a DC fan control system, characterized in that: The DC fan control system includes: a main controller and a DC fan drive controller, and the method includes: The DC fan drive controller sends a PWM identification request signal to the main controller; wherein the PWM identification request signal is generated based on a preset PWM duty cycle and a preset PWM frequency; After receiving the PWM identification request signal, the main controller generates a PWM identification confirmation signal based on the PWM identification request signal, and sends the PWM identification confirmation signal to the DC fan drive controller; After receiving the PWM identification confirmation signal, the DC fan drive controller obtains a confirmed PWM frequency based on the PWM identification confirmation signal, compares the confirmed PWM frequency with the preset PWM frequency, and determines whether a fault occurs based on the comparison result.

2. The fault identification method according to claim 1, characterized in that: The step of determining whether there is a fault according to the comparison result includes: If the comparison result is that the confirmed PWM frequency is the same as the preset PWM frequency, it is determined that there is no fault, and the DC fan is controlled to start; If the comparison result is that the confirmed PWM frequency is different from the preset PWM frequency, a communication failure is determined and an identification error signal is sent to the main controller.

3. The fault identification method according to claim 2, characterized in that: After the step of sending the identification error signal to the main controller, the method further includes: After receiving the recognition error signal, the main controller generates a recognition error fault code based on the recognition error signal, and sends the recognition error fault code to the display for display.

4. The fault identification method according to claim 1, characterized in that: The step of generating a PWM identification confirmation signal based on the PWM identification request signal comprises: The PWM frequency of the PWM identification confirmation signal is set to be the same as the PWM frequency of the received PWM identification request signal, and the PWM duty cycle of the PWM identification confirmation signal is set to the confirmed PWM duty cycle; wherein the confirmed PWM duty cycle is less than the minimum duty cycle for starting the DC fan.

5. A fault identification method for a DC fan control system, characterized in that: The DC fan control system includes: a main controller and a DC fan drive controller, and the method includes: After obtaining the current fan model and the current air distribution gear, the main controller determines a PWM control signal based on the current fan model and the current air distribution gear, and sends the PWM control signal to the DC fan drive controller; After the DC fan drive controller receives the PWM control signal, it matches the PWM duty cycle and PWM frequency of the PWM control signal in the preset air distribution data, and determines whether the main controller has identified the model error based on the matching result; wherein, the preset air distribution data at least includes the correspondence between multiple air distribution gears under its own fan model and the preset PWM frequency and the preset PWM duty cycle.

6. The fault identification method according to claim 5, characterized in that: The step of determining the PWM control signal based on the current fan model and the current air distribution gear position includes: Determine the PWM frequency of the PWM control signal based on the current air distribution gear, and determine the PWM duty cycle of the PWM control signal based on the current air distribution gear and the current fan model; The step of matching the PWM duty cycle and PWM frequency based on the PWM control signal with the preset air distribution data, and determining whether the main controller identifies the model error according to the matching result, includes: Determining the current air distribution gear position based on a matching result of the PWM frequency of the PWM control signal and a preset PWM frequency; Determining a preset PWM duty cycle based on the current air distribution gear position; The main controller determines whether a model error is identified based on a matching result between a PWM duty cycle of the PWM control signal and a preset PWM duty cycle.

7. The fault identification method according to claim 6, characterized in that: The step of determining whether the main controller identifies a model error based on a matching result between the PWM duty cycle of the PWM control signal and a preset PWM duty cycle includes: If the PWM duty cycle of the PWM control signal is the same as the preset PWM duty cycle, it is determined that the main controller has correctly identified the model; If the PWM duty cycle of the PWM control signal is different from the preset PWM duty cycle, it is determined that the main controller has identified an incorrect model.

8. The fault identification method according to claim 7, characterized in that: After the step of determining that the main controller has identified an incorrect model, the method further includes: The DC fan drive controller sends the current fan current to the main controller; The main controller updates the PWM duty cycle of the PWM control signal based on the current fan current and the target fan current; wherein the target fan current is determined by the current air distribution gear position; The step of updating the PWM duty cycle of the PWM control signal based on the current wind turbine current and the target wind turbine current includes: If the current fan current is greater than the target fan current, reducing the PWM duty cycle of the PWM control signal; If the current fan current is less than the target fan current, the PWM duty cycle of the PWM control signal is increased.

9. The fault identification method according to claim 8, characterized in that: The method further comprises: updating the PWM duty cycle of the PWM control signal based on the current fan current and the target fan current until the current fan current is the same as the target fan current, and re-determining the current fan model based on the updated PWM duty cycle of the PWM control signal; If the main controller updates the PWM duty cycle of the PWM control signal and cannot make the current fan current the same as the target fan current, the DC fan will be stopped, and an identification error fault code will be generated and sent to the display for display.

10. A DC fan control system, characterized in that: include: A main controller and a DC fan drive controller, the DC fan control system is used to perform the steps of the fault identification method according to any one of claims 1 to 9.

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