A method and device for driving a fan of a water heater and a water heater

Abstract

The application discloses a method and device for driving a fan of a water heater and the water heater. The method is applied to a fan driving chip and comprises the following steps: when the water heater starts heating, a real-time pulse width modulation value of the water heater is acquired, and a target driving mode interval matched with the real-time pulse width modulation value is determined according to a driving mode interval including at least two driving modes which is stored in advance; the operation of the fan of the water heater is controlled according to a driving mode corresponding to the target driving mode interval; during the operation of the fan, a real-time temperature rise of a MOS tube of a fan driving board is monitored; if the real-time temperature rise meets a preset temperature rise condition, the driving mode of the fan is switched; a pulse width modulation value at the time of switching is acquired and recorded; whether the driving mode interval is updated is judged according to the pulse width modulation value at the time of switching; and the method effectively avoids the case that the temperature rise of the MOS tube is too high, improves the precision of the fan mode switching control, and improves the stability and reliability of the fan control.

Description

Technical Field

[0001] This application relates to the field of water heater control technology, and in particular to a method for driving a fan of a water heater, a device for driving a fan of a water heater, and a water heater. Background Technology

[0002] Currently, some DC fans used in gas water heaters employ SVPWM (Space Vector Pulse Width Modulation) drive control. This drive control method can use different segment control modes, with the most common being 7-segment or 5-segment.

[0003] When driving a DC motor, a 7-segment control method offers the advantage of a modulation current closer to a sine wave and lower harmonic interference. However, it involves more switching operations and higher switching losses, leading to increased heat generation in the MOSFETs, resulting in excessive temperature rise and reduced efficiency. A 5-segment control method, on the other hand, has the advantage of fewer switching operations and lower switching losses, resulting in less heat generation in the MOSFETs. However, fewer switching operations also lead to higher harmonic interference, making it easier for EMI (Electro-Magnetic Interference) tests to exceed limits.

[0004] Therefore, traditional technologies often employ cross-control by switching modes. However, this typically involves setting up a flue and electrical environment in a laboratory setting. Experiments are then conducted under this standard environment based on the water heater's combustion load and fan speed, measuring the corresponding temperature of the MOSFET. The switching range corresponding to the MOSFET temperature at each combustion load and fan speed is then obtained. This method yields a relatively fixed switching range because it is obtained under a standard environment. However, the environment in which the water heater is installed and operates in the user's home differs from the standard environment to varying degrees, which can easily lead to low precision in mode switching control and affect the stability and reliability of fan control. Summary of the Invention

[0005] This application provides a method, apparatus, and water heater for driving a fan in a water heater, thereby overcoming the aforementioned shortcomings of existing DC motor drives.

[0006] According to a first aspect of this application, a method for driving a fan in a water heater is provided, the method being applied in a fan drive chip, the method comprising:

[0007] When the water heater starts heating, the real-time pulse width modulation value of the water heater is obtained, and a target driving mode interval that matches the real-time pulse width modulation value is determined according to a pre-stored driving mode interval including at least two driving modes.

[0008] The operation of the water heater fan is controlled according to the drive mode corresponding to the target drive mode range;

[0009] During the operation of the fan, the real-time temperature rise of the MOS transistor on the fan drive board is monitored;

[0010] If the real-time temperature rise meets the preset temperature rise condition, the drive mode of the fan is switched.

[0011] Acquire and record the pulse width modulation value of the water heater during switching;

[0012] Whether to update the drive mode range is determined based on the pulse width modulation value of the water heater during the switching.

[0013] According to a second aspect of this application, a device for driving a fan in a water heater is provided, the device being incorporated into a fan drive chip, the device comprising:

[0014] The pulse width modulation value acquisition module is used to acquire the real-time pulse width modulation value of the water heater when the water heater starts heating.

[0015] The target drive mode interval determination module is used to determine the target drive mode interval that matches the real-time pulse width modulation value based on a pre-stored drive mode interval including at least two drive modes.

[0016] The fan control module is used to control the operation of the water heater fan according to the drive mode corresponding to the target drive mode range;

[0017] The MOSFET monitoring module is used to monitor the real-time temperature rise of the MOSFETs on the fan drive board during the operation of the fan; if the real-time temperature rise meets the preset temperature rise condition, the switching module is invoked.

[0018] A switching module is used to switch the driving mode;

[0019] The drive mode interval update judgment module is used to acquire and record the pulse width modulation value of the water heater when switching, and to determine whether to update the drive mode interval based on the pulse width modulation value of the water heater when switching.

[0020] According to a third aspect of this application, a water heater is provided, including a main controller and a fan drive chip connected to the main controller. The fan drive chip includes at least one processor and a memory connected to the at least one processor. The memory stores a computer program executable by the at least one processor, which is executed by the at least one processor to enable the at least one processor to perform the method described in the first aspect.

[0021] In this embodiment, when the water heater starts heating, it determines the target drive mode range that matches the acquired PWM value, and then controls the operation of the water heater fan according to the drive mode corresponding to the target drive mode range. During the operation of the fan, the temperature rise of the MOSFET is also monitored. A 7-segment drive mode is used at low duty cycles to improve efficiency, and a 5-segment drive mode is used at high duty cycles to reduce the temperature rise of the MOSFET. This avoids the problem of excessive temperature rise of the power MOSFET caused by continuously using the 7-segment drive mode, and also avoids the problem of large harmonic interference caused by continuously using the 5-segment drive mode. This improves the drive efficiency of the fan and the operating efficiency and stability of the motor, while ensuring that EMI testing meets the requirements.

[0022] Furthermore, since the initial drive mode range is obtained from testing under standard experimental conditions, and the environment in which the water heater is installed and operates in a user's home differs from the standard environment to varying degrees, it can easily lead to low precision in mode switching control, affecting the stability and reliability of fan control. Therefore, this embodiment also records the PWM value of the water heater during switching and determines whether to update the drive mode range based on this PWM value. This enables dynamic modulation of the DC fan space vector pulse width of the gas water heater, controlling the fan to operate in an optimal state, making the fan operation more adaptable to the current environment, and improving the fan's driving effect and efficiency.

[0023] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this application, nor is it intended to limit the scope of this application. Other features of this application will become readily apparent from the following description. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a flowchart of an embodiment of a method for driving a fan of a water heater provided in Embodiment 1 of this application;

[0026] Figure 2 This is a pulse width modulation method with a 7-segment driving mode provided in Embodiment 1 of this application;

[0027] Figure 3 This is a pulse width modulation method with a 5-segment driving mode provided in Embodiment 1 of this application;

[0028] Figure 4This is a schematic diagram of the connection architecture of a wind turbine drive chip provided in Embodiment 1 of this application;

[0029] Figure 5 This is a flowchart of an exemplary scenario embodiment of driving a fan in a water heater, provided in Embodiment 1 of this application;

[0030] Figure 6 This is a schematic diagram of a device for driving a fan of a water heater, provided in Embodiment 2 of this application;

[0031] Figure 7 This is a schematic diagram of the structure of a water heater provided in Embodiment 3 of this application. Detailed Implementation

[0032] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0033] Example 1

[0034] Figure 1 This is a flowchart illustrating a method for driving a fan in a water heater, as provided in Embodiment 1 of this application. The fan can be a DC fan located inside the gas water heater. A DC fan is a fan that converts DC electrical energy into mechanical energy by inputting DC electrical energy, causing a DC motor to rotate and thus driving the fan impeller. The most significant characteristic of a DC fan is the use of a DC motor.

[0035] This embodiment can be applied to a wind turbine driver chip, which controls the operation of the wind turbine through a drive control circuit.

[0036] During the operation of the fan, if an abnormal fault occurs (such as short circuit or open circuit in the fan winding, jamming of the fan impeller, severe blockage of the fan duct, excessively high or low operating voltage of the fan, etc.), the fan drive chip can automatically detect it and immediately stop the fan operation, as well as send a fault code to the main controller of the gas water heater. The gas water heater then displays the fault information on the display.

[0037] like Figure 1 As shown, this embodiment may include the following steps:

[0038] Step 101: When the water heater starts heating, obtain the real-time pulse width modulation value of the water heater, and determine the target drive mode interval that matches the real-time pulse width modulation value according to the pre-stored drive mode interval including at least two drive modes.

[0039] Pulse-width modulation (PWM) is an analog control method that modulates the bias of the base of a transistor or the gate of a MOSFET according to changes in the load, thereby changing the conduction time of the transistor or MOSFET and thus changing the output of the switching power supply. This method allows the power supply's output voltage to remain constant under changing operating conditions and is a very effective technique for controlling analog circuits using digital signals from a microprocessor.

[0040] When the water heater starts heating, the fan drive chip receives the PWM value sent by the main controller of the water heater and controls the operation of the fan according to the PWM value.

[0041] After the fan drive chip obtains the PWM value of the water heater, it reads at least two pre-stored drive mode intervals and matches the PWM value with each drive mode interval to determine the drive mode interval into which the PWM value falls as the target drive mode interval.

[0042] Each drive mode range has a corresponding drive mode, namely the SVPWM drive mode. The SVPWM drive mode can include a 7-segment drive mode and a 5-segment drive mode. The pulse width modulation method of the 7-segment drive mode is as follows: Figure 2 As shown, its characteristic is that all three lower bridge arms have chopping within one carrier cycle, which has the advantage of the modulation current being closer to a sine wave. The disadvantages are a high number of switching cycles, high switching losses, and high heat generation in the power MOSFETs. The pulse width modulation method of the 5-segment drive mode is as follows: Figure 3 As shown, its characteristics include only two lower bridge arms chopping within one carrier cycle, fewer switching cycles, lower switching losses, and lower power MOSFET heat generation, but it also has significant interference from modulation current harmonics. Therefore, this embodiment can combine the advantages of the 7-segment drive mode and the 5-segment drive mode, leveraging their strengths and avoiding their weaknesses, and dynamically switching between the 7-segment drive mode and the 5-segment drive mode.

[0043] Step 102: Control the operation of the water heater fan according to the drive mode corresponding to the target drive mode range.

[0044] For example, if the drive mode range of the 7-segment control mode is 0% to 30%, and the drive mode range of the 5-segment control mode is 30% to 100%, assuming the PWM value is 28%, then it falls within the drive mode range of 0% to 30%, and the operation of the water heater fan can be controlled according to the 7-segment control mode.

[0045] Step 103: During the operation of the fan, monitor the real-time temperature rise of the MOSFET on the fan drive board.

[0046] In one embodiment, the real-time temperature rise of the MOSFET on the fan drive board can be monitored in step 103 as follows:

[0047] Step 103-1-1: Obtain the temperature of each power MOSFET in the driver board.

[0048] The drive board of the fan can include multiple power MOSFETs. By measuring the temperature of each power MOSFET, the real-time temperature rise of the drive board can be obtained. In particular, by detecting the temperature of each power MOSFET, the occurrence of overheating of the MOSFETs can be reduced, thereby improving the service life of the drive board.

[0049] The fan driver chip can acquire the temperature of each power MOSFET in the driver board. In one implementation, a temperature detection circuit connected to each power MOSFET can be used in the driver board to detect the temperature of that power MOSFET. Specifically, for example... Figure 4 As shown, the temperature detection circuit of each power MOSFET is connected between the fan driver chip and the power MOSFET to measure the temperature of the power MOSFET. Then, the measured temperature AD signal is transmitted to the fan driver chip for processing through the I / O port of the microcontroller.

[0050] Step 103-1-2: Select the highest temperature from the temperatures of each power MOSFET and record it as the highest temperature of the power MOSFET.

[0051] After obtaining the temperatures of each power MOSFET of the fan, the fan driver chip selects the highest temperature and records it as the maximum temperature of the power MOSFET, T(MOS_MAX).

[0052] Step 103-1-3: Obtain the real-time ambient temperature of the driver board.

[0053] In implementation, such as Figure 4 As shown, the fan drive chip is connected to the main controller of the gas water heater. An ambient temperature detection circuit can be set in the gas water heater. Through this ambient temperature detection circuit and the matching temperature sensor, the main controller can obtain the real-time ambient temperature T (ambient) and send the real-time ambient temperature to the fan drive chip.

[0054] Step 103-1-4: Determine the real-time temperature rise of the MOSFET based on its maximum temperature and the real-time ambient temperature.

[0055] In implementation, the temperature difference between the highest temperature of the power MOSFET and the real-time ambient temperature can be calculated, and then this temperature difference can be converted into a real-time temperature rise, which is used as the real-time temperature rise of the MOSFET.

[0056] Step 104: If the real-time temperature rise meets the preset temperature rise condition, then the drive mode of the fan is switched.

[0057] If the real-time temperature rise meets the preset temperature rise condition, it can be considered that the switching time for the fan's SVPWM drive mode has been reached, and the fan's SVPWM drive mode can be switched. For example, if the current drive mode is a 5-segment drive mode, then switch to a 7-segment drive mode; if the current drive mode is a 7-segment drive mode, then switch to a 5-segment drive mode.

[0058] In one embodiment, step 104 may include:

[0059] Step 104-1: Obtain the preset temperature rise conditions for the drive mode corresponding to the target drive mode range.

[0060] Step 104-2: If the real-time temperature rise meets the preset temperature rise condition, then the driving mode is switched.

[0061] In implementation, once the driving mode corresponding to the current target driving mode range is determined, the preset temperature rise conditions of the driving mode corresponding to the target driving mode range can be read from the data pre-recorded by the water heater.

[0062] For example, the preset temperature rise conditions may include a preset temperature rise threshold and a preset duration.

[0063] Specifically, if the current driving mode is a 7-segment driving mode, when the real-time temperature rise is greater than or equal to the preset temperature rise threshold, and the duration of the real-time temperature rise being greater than or equal to the preset temperature rise threshold reaches the preset duration, then the current real-time temperature rise is determined to meet the preset temperature rise condition.

[0064] For example, if the current driving mode is a 7-segment driving mode, when T (temperature rise) ≥ T (MOS_temperature rise threshold) and stabilizes for 5 seconds, it is determined that the current real-time temperature rise of the driver board meets the preset temperature rise condition for switching.

[0065] If the current driving mode is a 5-stage driving mode, when the real-time temperature rise is less than the preset temperature rise threshold, and the duration of the real-time temperature rise being less than the preset temperature rise threshold reaches the preset duration, it is determined that the real-time temperature rise meets the preset temperature rise condition.

[0066] For example, if the current driving mode is a 5-segment driving mode, when T (temperature rise) < T (MOS_temperature rise threshold) and stabilizes for 5 seconds, it is determined that the current real-time temperature rise of the driver board meets the preset temperature rise condition for switching.

[0067] The preset temperature rise threshold can be a fixed value, or it can be an adjustable range of that fixed value. For example, a temperature rise limit can be set, and the preset temperature rise threshold = temperature rise limit - 10K, i.e., T(MOS_temperature rise threshold) = T(MOS_MAX) - 10K. It is understandable that in actual operation, for example, when the water heater switches from a 7-stage to a 5-stage function, the temperature of the MOS tube will not immediately drop, but will often continue to rise first, then stabilize before slowly decreasing.

[0068] Step 105: Obtain and record the pulse width modulation value of the water heater during switching.

[0069] When switching between SVPWM drive modes, the PWM value of the water heater at the time of switching can also be recorded. In implementation, when the fan's SVPWM drive mode switches, the fan driver chip can record the PWM value obtained at this time as the PWM value of the water heater at the time of switching. For example, when the fan switches from a 7-segment drive mode to a 5-segment drive mode, its PWM value can be recorded as PWM(7to5); when the fan switches from a 5-segment drive mode to a 7-segment drive mode, its PWM value can be recorded as PWM(5to7).

[0070] Step 106: Determine whether to update the drive mode range based on the pulse width modulation value of the water heater during switching.

[0071] Once a mode switch occurs and the PWM value of the water heater at the time of the switch is obtained, the fan drive chip can determine whether to update each drive mode range based on the PWM value.

[0072] In one embodiment, step 106 may further include the following steps:

[0073] Step 106-1: Obtain the buffer space of the drive mode range.

[0074] The buffer zone refers to the range of change in the switching point between two adjacent drive mode zones. For example, if the drive mode zone of the 7-segment control mode is 0% to 30%, and the drive mode zone of the 5-segment control mode is 30% to 100%, with a switching point of 30%, the buffer zone can be [26%, 30%].

[0075] In one implementation, the buffer space can be stored in the water heater's storage area, and then the current drive mode range of the buffer space can be read from the water heater's storage area.

[0076] Step 106-2: Determine whether the pulse width modulation value of the water heater during the switching belongs to the buffer zone. If it does not, proceed to step 106-3.

[0077] In this step, if the water heater's PWM value falls within the buffer range during mode switching, it indicates that the water heater's current operating environment is a standard environment, and no adjustment to the drive mode range and buffer range is required. If the water heater's PWM value is outside the buffer range during mode switching, it indicates that the water heater's current operating environment is not a standard environment, and the drive mode range and buffer range need to be adjusted to better adapt the fan's operation to the current operating environment. Setting the buffer range effectively avoids frequent updates.

[0078] Step 106-3: Update the drive mode range based on the pulse width modulation value of the water heater during the switching, and update the buffer range based on the pulse width modulation value of the water heater during the switching.

[0079] In one implementation, if the PWM value of the water heater is outside the buffer range during switching, the PWM value of the water heater at the time of switching can be used as the switching point to update the corresponding drive mode range and buffer range. For example, if the PWM value of the drive mode range in the 7-segment control mode is 0%–30%, and the PWM value of the drive mode range in the 5-segment control mode is 30%–100%, the switching point is 30%, and the buffer range is [26%, 30%]. During the operation of the water heater driving the fan in the 7-segment control mode, the temperature rise continuously causes the drive mode to switch from the 7-segment control mode to the 5-segment control mode. At the time of switching, the PWM value of the water heater is 33%. Therefore, 33% is used as the switching point to update the drive mode ranges of the 7-segment and 5-segment control modes. The updated drive mode range for the 7-segment control mode is 0%–33%, and the drive mode range for the 5-segment control mode is 33%–100%. Additionally, the buffer can be updated at 33% as the switching point, resulting in a buffer range of [29%, 33%] (assuming a default range of 5% fluctuation between buffers).

[0080] In another embodiment, step 106 may further include the following steps:

[0081] Determine whether the preset update cycle has been reached; if not, continue recording the pulse width modulation value of the water heater during the switch; if so, calculate the average value of the pulse width modulation value of the water heater during the switch, and determine whether to update the drive mode range and buffer based on the average value.

[0082] The difference between this embodiment and the previous embodiment is that the previous embodiment determines whether the drive mode interval and buffer interval need to be updated each time the pulse width modulation value of the water heater is obtained during switching. In this embodiment, the pulse width modulation value of the water heater is recorded each time the switch is obtained, and the drive mode interval and buffer interval are not immediately determined. Instead, after the update cycle arrives, the average value of the recorded pulse width modulation value is used to determine whether the drive mode interval and buffer interval need to be updated, thereby further avoiding frequent updates of the drive mode interval and buffer interval.

[0083] For example, the update cycle could be one week. Within this cycle, the recorded PWM values ​​are PWM(7to5) 33% and PWM(5to7) 29%, respectively. The average value would then be (33% + 29%) / 2 = 31%. Therefore, 31% can be used as the switching point to update the drive mode ranges for both the 7-segment and 5-segment control modes. The updated drive mode range for the 7-segment control mode would be 0%–31%, and for the 5-segment control mode, it would be 31%–100%. Simultaneously, the buffer range can also be updated using 31% as the switching point, resulting in a buffer range of [27%, 31%] (assuming a default range of 5% fluctuation for the buffer range).

[0084] In other embodiments, in step 106, the buffer interval can be updated based on the PWM value of the water heater at the time of switching, and then the drive mode interval can be updated based on the updated buffer interval. For example, assuming PWM(7to5) is 33% and PWM(5to7) is 29%, the buffer interval is [29%, 33%]. Next, the drive mode interval can be divided using the maximum value of the buffer interval as the switching point, such as the updated 7-segment control mode drive mode interval being 0%–33%, and the updated 5-segment control mode drive mode interval being 33%–100%. Alternatively, the average value of the buffer interval, 31%, can be used as the switching point to divide the drive mode interval into 0%–31% and 31%–100%.

[0085] In one embodiment, the following steps may also be included:

[0086] When the drive mode is switched to the 5-stage drive mode, if the real-time temperature rise exceeds the preset limit, the fan is judged to be faulty and the fan is controlled to stop running.

[0087] Specifically, when the drive mode is switched to the 5-segment drive mode, the real-time temperature rise will decrease as the heat generated by the power MOSFET decreases. For example, after switching to the 5-segment drive mode, if T(temperature rise) ≥ T(MOS_MAX) - 10K, and after 1 minute, T(temperature rise) ≥ T(MOS_MAX), then the MOSFET is considered to be operating abnormally, and a fan failure can be determined. At this time, the fan can be controlled to stop running.

[0088] One method to stop the fan is as follows: the fan drive chip stops the fan and sends a stop command to the main controller of the gas water heater. The main controller then displays the corresponding fault code on the corresponding display.

[0089] To enable those skilled in the art to better understand the embodiments of this application, reference is made to... Figure 5 This embodiment will be illustrated by an example of an application scenario:

[0090] Step S1: Power on the gas water heater and obtain the PWM value of the water heater; then execute step S2 or step S3.

[0091] Step S2: When the PWM value is within the range of 0% to 30% in the drive mode range, the fan is driven in 7-segment control mode, and step S4 is executed.

[0092] Step S3: When the PWM value is within the range of 30% to 100% in the drive mode range, the fan is driven in the 5-segment control mode, and step S4 is executed.

[0093] Step S4: During the operation of the fan, continuously monitor the real-time temperature rise of the MOSFET on the fan drive board, and determine whether to preset the temperature rise condition based on the real-time temperature rise; if not, continue to monitor the real-time temperature rise of the MOSFET in step S4; if yes, proceed to step S5.

[0094] Step S5: Switch the drive mode of the wind turbine, including: switching the current 7-segment control mode to a 5-segment control mode, or switching the current 5-segment control mode to a 7-segment control mode; continue to execute step S6 or S7.

[0095] Step S6: Obtain and record the PWM value of the water heater when switching, and determine whether to update the drive mode range based on the PWM value of the water heater when switching, and update the drive mode range when it is necessary to update it.

[0096] Step S7: After the drive mode is switched to the 5-stage drive mode, if the real-time temperature rise exceeds the preset limit, the fan is determined to be faulty and the fan is controlled to stop running.

[0097] In this embodiment, when the water heater starts heating, it determines the target drive mode range that matches the acquired PWM value, and then controls the operation of the water heater fan according to the drive mode corresponding to the target drive mode range. During the operation of the fan, the real-time temperature rise of the MOSFET on the fan drive board is also monitored. When the real-time temperature rise meets the preset temperature rise condition, the current drive mode is switched. A 7-segment drive mode is used to improve efficiency at low duty cycles, and a 5-segment drive mode is used to reduce the temperature rise of the MOSFET at high duty cycles. This avoids the problem of reduced efficiency caused by excessive temperature rise of the power MOSFET due to continuous use of the 7-segment drive mode, and also avoids the problem of large harmonic interference caused by continuous use of the 5-segment drive mode. This improves the drive efficiency of the fan and the operating efficiency and stability of the motor, while ensuring that EMI testing meets the requirements.

[0098] Furthermore, since the initial drive mode range is obtained from testing under standard experimental conditions, and the environment in which the water heater is installed and operates in a user's home differs from the standard environment to varying degrees, it can easily lead to low precision in mode switching control, affecting the stability and reliability of fan control. Therefore, this embodiment also records the PWM value of the water heater during switching and determines whether to update the drive mode range based on this PWM value. This enables dynamic modulation of the DC fan space vector pulse width of the gas water heater, controlling the fan to operate in an optimal state, making the fan operation more adaptable to the current environment, and improving the fan's driving effect and efficiency.

[0099] Example 2

[0100] Figure 6 This is a schematic diagram of a device for driving a fan in a water heater, provided in Embodiment 2 of this application. The device is applied in a fan drive chip and may include the following modules:

[0101] The pulse width modulation value acquisition module 201 is used to acquire the real-time pulse width modulation value of the water heater when the water heater starts heating.

[0102] The target drive mode range determination module 202 is used to determine a target drive mode range that matches the real-time pulse width modulation value based on a pre-stored drive mode range including at least two drive modes.

[0103] The fan control module 203 is used to control the operation of the water heater fan according to the drive mode corresponding to the target drive mode range;

[0104] The MOS transistor monitoring module 204 is used to monitor the real-time temperature rise of the MOS transistor on the fan drive board during the operation of the fan; if the real-time temperature rise meets the preset temperature rise condition, the switching module is invoked.

[0105] The switching module 205 is used to switch the driving mode;

[0106] The drive mode interval update judgment module 206 is used to acquire and record the pulse width modulation value of the water heater when switching, and to determine whether to update the drive mode interval based on the pulse width modulation value of the water heater when switching.

[0107] In one embodiment, the MOS transistor monitoring module 204 is specifically used for:

[0108] Obtain the temperature of each power MOSFET in the driver board;

[0109] Select the highest temperature from the temperatures of each power MOSFET and record it as the highest temperature of the power MOSFET.

[0110] Obtain the real-time ambient temperature of the driver board;

[0111] The real-time temperature rise of the MOSFET is determined based on the highest temperature of the power MOSFET and the real-time ambient temperature.

[0112] In one embodiment, the MOSFET monitoring module 204 is further configured to:

[0113] The temperature of each power MOSFET is detected by a temperature detection circuit connected to each power MOSFET in the driver board.

[0114] In one embodiment, the driving mode includes a 7-stage driving mode and a 5-stage driving mode; the preset temperature rise condition includes a preset temperature rise threshold and a preset duration.

[0115] When the driving mode is the 7-segment driving mode, if the real-time temperature rise is greater than or equal to the preset temperature rise threshold, and the duration for which the real-time temperature rise is greater than or equal to the preset temperature rise threshold reaches the preset duration, then it is determined that the real-time temperature rise meets the preset temperature rise condition.

[0116] When the driving mode is the 5-segment driving mode, if the real-time temperature rise is less than the preset temperature rise threshold, and the duration for which the real-time temperature rise is less than the preset temperature rise threshold reaches the preset duration, then it is determined that the real-time temperature rise meets the preset temperature rise condition.

[0117] In one embodiment, the device may further include a fan fault handling module, used for:

[0118] When the drive mode is switched to the 5-segment drive mode, if the real-time temperature rise exceeds the preset limit, the fan is determined to be faulty.

[0119] Control the fan to stop running.

[0120] In one embodiment, the driving mode interval update determination module 206 is specifically used for:

[0121] Obtain the buffer space of the drive mode range;

[0122] Determine whether the pulse width modulation value of the water heater during the switching process belongs to the buffer zone;

[0123] If it does not belong to the range, the drive mode range is updated based on the pulse width modulation value of the water heater at the time of switching, and the buffer range is updated based on the pulse width modulation value of the water heater at the time of switching.

[0124] In another embodiment, the driving mode interval update determination module 206 is specifically used for:

[0125] Determine whether the preset update cycle has been reached;

[0126] If not, continue recording the pulse width modulation value of the water heater during switching;

[0127] If so, calculate the average value of the pulse width modulation value of the water heater during the switching, and determine whether to update the drive mode interval and the buffer interval based on the average value.

[0128] The device for driving the fan of a water heater provided in this application embodiment can execute the method for driving the fan of a water heater provided in the above-described method embodiment of this application, and has the corresponding functional modules and beneficial effects of executing the method.

[0129] Example 3

[0130] Figure 7 A schematic diagram of the structure of a water heater 10, which can be used to implement an embodiment of the method of this application, is shown. Figure 7 As shown, the water heater 10 may include a main controller 11 and a fan drive chip 12 connected to the main controller 11. The fan drive chip 12 includes at least one processor 121 and a memory, such as a read-only memory (ROM) 122 or a random access memory (RAM) 123, communicatively connected to the at least one processor 121. The memory stores computer programs executable by the at least one processor 121. The processor 121 can perform various appropriate actions and processes based on the computer program stored in the ROM 122 or loaded into the RAM 123. The RAM 123 may also store various programs and data required for the operation of the fan drive chip 12. The processor 121, ROM 122, and RAM 123 are interconnected via a bus 124.

[0131] Processor 121 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of processor 121 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. Processor 121 performs the various methods and processes described above.

[0132] In some embodiments, the method described in Embodiment 1 may be implemented as a computer program tangibly contained in a computer-readable storage medium. In some embodiments, part or all of the computer program may be loaded and / or mounted on the wind turbine driver chip 12 via ROM 122. When the computer program is loaded into RAM 123 and executed by processor 121, one or more steps of the method described in Embodiment 1 above may be performed. Alternatively, in other embodiments, processor 121 may be configured to perform the method described in Embodiment 1 by any other suitable means (e.g., by means of firmware).

[0133] It should be understood that the various forms of processes shown above can be used to rearrange, add, or delete steps. For example, the steps described in this application can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this application can be achieved, and this is not limited herein.

[0134] The specific embodiments described above do not constitute a limitation on the scope of protection of this application. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A method for driving a fan in a water heater, characterized in that, The method is applied to a wind turbine drive chip, and the method includes: When the water heater starts heating, the real-time pulse width modulation value of the water heater is obtained, and a target driving mode interval that matches the real-time pulse width modulation value is determined according to a pre-stored driving mode interval including at least two driving modes. The operation of the water heater fan is controlled according to the drive mode corresponding to the target drive mode range; During the operation of the fan, the real-time temperature rise of the MOS transistor on the fan drive board is monitored; If the real-time temperature rise meets the preset temperature rise condition, the drive mode of the fan is switched. Acquire and record the pulse width modulation value of the water heater during switching; Whether to update the drive mode range is determined based on the pulse width modulation value of the water heater during the switching.

2. The method according to claim 1, characterized in that, The real-time temperature rise of the MOSFET on the fan drive board is monitored, including: Obtain the temperature of each power MOSFET in the driver board; Select the highest temperature from the temperatures of each power MOSFET and record it as the highest temperature of the power MOSFET. Obtain the real-time ambient temperature of the driver board; The real-time temperature rise of the MOSFET is determined based on the highest temperature of the power MOSFET and the real-time ambient temperature.

3. The method according to claim 2, characterized in that, The step of obtaining the temperature of each power MOSFET in the driver board includes: The temperature of each power MOSFET is detected by a temperature detection circuit connected to each power MOSFET in the driver board.

4. The method according to claim 1, characterized in that, The driving modes include a 7-segment driving mode and a 5-segment driving mode; The preset temperature rise conditions include a preset temperature rise threshold and a preset duration. The real-time temperature rise meets the preset temperature rise conditions, including: When the driving mode is the 7-segment driving mode, if the real-time temperature rise is greater than or equal to the preset temperature rise threshold, and the duration for which the real-time temperature rise is greater than or equal to the preset temperature rise threshold reaches the preset duration, then it is determined that the real-time temperature rise meets the preset temperature rise condition. When the driving mode is the 5-segment driving mode, if the real-time temperature rise is less than the preset temperature rise threshold, and the duration for which the real-time temperature rise is less than the preset temperature rise threshold reaches the preset duration, then it is determined that the real-time temperature rise meets the preset temperature rise condition.

5. The method according to claim 4, characterized in that, The method further includes: When the drive mode is switched to the 5-segment drive mode, if the real-time temperature rise exceeds the preset limit, the fan is determined to be faulty. Control the fan to stop running.

6. The method according to claim 1, characterized in that, Determining whether to update the drive mode range based on the pulse width modulation value of the water heater during the switching includes: Obtain the buffer space of the drive mode range; Determine whether the pulse width modulation value of the water heater during the switching process belongs to the buffer zone; If it does not belong to the range, the drive mode range is updated based on the pulse width modulation value of the water heater at the time of switching, and the buffer range is updated based on the pulse width modulation value of the water heater at the time of switching.

7. The method according to claim 1, characterized in that, The step of determining whether to update the drive mode range based on the pulse width modulation value of the water heater during the switching includes: Determine whether the preset update cycle has been reached; If not, continue recording the pulse width modulation value of the water heater during switching; If so, calculate the average value of the pulse width modulation value of the water heater during the switching, and determine whether to update the drive mode interval and the buffer between the drive mode intervals based on the average value.

8. A device for driving a fan in a water heater, characterized in that, The device is used in a wind turbine drive chip, and the device includes: The pulse width modulation value acquisition module is used to acquire the real-time pulse width modulation value of the water heater when the water heater starts heating. The target drive mode interval determination module is used to determine the target drive mode interval that matches the real-time pulse width modulation value based on a pre-stored drive mode interval including at least two drive modes. The fan control module is used to control the operation of the water heater fan according to the drive mode corresponding to the target drive mode range; The MOSFET monitoring module is used to monitor the real-time temperature rise of the MOSFETs on the fan drive board during the operation of the fan; if the real-time temperature rise meets the preset temperature rise condition, the switching module is invoked. A switching module is used to switch the driving mode; The drive mode interval update judgment module is used to acquire and record the pulse width modulation value of the water heater when switching, and to determine whether to update the drive mode interval based on the pulse width modulation value of the water heater when switching.

9. A water heater, characterized in that, The device includes a main controller and a wind turbine drive chip connected to the main controller. The wind turbine drive chip includes at least one processor and a memory connected to the at least one processor. The memory stores a computer program that can be executed by the at least one processor, and the computer program is executed by the at least one processor to enable the at least one processor to perform the method of any one of claims 1-7.

Images