A fan control method and system for heat dissipation of different heat sources

Abstract

The application discloses a fan control method and system for heat dissipation of different heat sources, relates to the field of engineering machinery, and comprises the following steps: collecting a heat source temperature signal, obtaining a PWM fan input duty ratio, taking a maximum value of the fan input duty ratio, and controlling a fan motor according to a PWM fan output value. The control method integrates the duty ratios of different heat sources to realize one machine controlling multiple machines. The control method can automatically adjust the rotating speed of the fan according to the temperature of each heat source, can reduce noise, save energy, prolong the service life of the fan, and can simultaneously meet the heat dissipation requirements of different heat sources by taking the maximum value of the duty ratios required for heat dissipation of different heat sources. The control system comprises a signal acquisition unit for collecting the temperature of the heat source and a main control unit for controlling the fan motor.

Description

Technical Field

[0001] This application relates to the field of engineering machinery, and in particular to a fan control method and system for cooling different heat sources. Background Technology

[0002] Currently, the general construction machinery industry uses DC24V to drive DC fans to dissipate heat from the source. This traditional cooling method has shortcomings such as high noise, high power consumption, and short service life. However, fans controlled by PWM signals can automatically adjust the fan speed according to the water temperature at each sensing point, which has the advantages of reducing noise, saving energy, and extending the fan's service life.

[0003] For operating conditions where multiple heat sources dissipate heat simultaneously, existing technologies lack effective control methods that can meet the heat dissipation needs of different heat sources while saving energy and extending lifespan. Summary of the Invention

[0004] This application provides a fan control method and system for cooling different heat sources, which can automatically adjust the fan speed according to the temperature of each heat source, and simultaneously meet the cooling needs of different heat sources.

[0005] In a first aspect, this application provides a fan control method for cooling different heat sources, comprising: Step S100: Collect temperature signals from different heat sources; Step S200: Obtain the PWM fan input duty cycle corresponding to different heat sources based on the temperature signal; Step S300: Based on all PWM fan input duty cycles, take the maximum value; Step S400: Calculate the PWM fan output value based on the maximum value of the PWM fan input duty cycle, and control the fan motor according to the PWM fan output value.

[0006] Preferably, in step S100, the heat source includes a charger, an oil pump motor controller, and an oil pump motor.

[0007] Preferably, step S200 includes: Step S210: Obtain the PWM fan input duty cycle corresponding to the charger according to Formula 1.

[0008] in, This indicates the PWM fan input duty cycle corresponding to the charger. This indicates the measured temperature of the charger; The raw parameters representing the measured temperature of the charger; Step S220: Obtain the PWM fan input duty cycle corresponding to the oil pump motor controller according to Formula 2.

[0009] in, This indicates the PWM fan input duty cycle corresponding to the oil pump motor controller. This indicates the measured temperature of the oil pump motor controller; The original parameters representing the measured temperature of the oil pump motor controller; Step S230: Obtain the PWM fan input duty cycle corresponding to the oil pump motor according to Formula 3.

[0010] in, This indicates the PWM fan input duty cycle corresponding to the oil pump motor. This indicates the measured temperature of the oil pump motor; The original parameter represents the measured temperature of the oil pump motor.

[0011] Preferably, in step S210, when hour, ; when hour, ; In step S220, when hour, ; when hour, ; In step S230, when hour, ; when hour, .

[0012] Preferably, in step S300, the maximum value of the input duty cycle is obtained according to Formula 4;

[0013] in, This indicates the maximum value of the PWM fan input duty cycle.

[0014] Preferably, step S400 includes: Step S410: Use a ramp function to ramp the maximum value of the PWM fan input duty cycle; Step S420: Calculate the PWM fan output value based on the maximum value of the PWM fan input duty cycle.

[0015] Preferably, in step S410, the ramp processing is configured to have a predetermined acceleration time and deceleration time, with the acceleration time set to 3500 milliseconds and the deceleration time set to 1500 milliseconds.

[0016] Preferably, in step S420, the PWM fan output value is calculated according to formula five;

[0017] in, This indicates the PWM fan output value.

[0018] Preferably, when When the temperature exceeds the set threshold, the auxiliary cooling system will be activated.

[0019] Secondly, this application provides a fan control system for cooling different heat sources, including a signal acquisition unit and a main control unit. The signal acquisition unit is connected to the main control unit and is used to acquire temperature signals from different heat sources. The main control unit is equipped with a fan control method.

[0020] The control method and system of this application have at least the following beneficial effects: This application achieves multi-control by integrating the duty cycles of different heat sources. This application can automatically adjust the fan speed according to the temperature of each heat source, which can reduce noise, save energy, and extend the service life of the fan. Furthermore, after calculating the duty cycle required for heat dissipation of different heat sources, the maximum value is taken, which can simultaneously meet the heat dissipation needs of different heat sources. Attached Figure Description

[0021] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 This is a graph showing the relationship between the fan duty cycle and speed in Example 1; Figure 2 This is the first flowchart of the control method in Embodiment 1; Figure 3 This is the second flowchart of the control method in Example 1; Figure 4 This is a control relationship diagram between the duty cycle and the charger in Example 1; Figure 5 This is a control relationship diagram between the duty cycle and the oil pump motor controller in Example 1; Figure 6 This is a control relationship diagram between duty cycle and oil pump motor in Example 1; Figure 7This is a schematic diagram of the duty cycle ramp processing function in Example 1; Figure 8 This is a flowchart of the control method in Example 2; Figure 9 This is a schematic diagram of the control system in Example 3; The annotations in the attached figures are explained as follows: 100. Signal acquisition unit; 200. Main control unit. Detailed Implementation

[0022] The features and exemplary embodiments of various aspects of this application will be described in detail below. To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain this application and not to limit it. For those skilled in the art, this application can be implemented without some of these specific details. The following description of the embodiments is merely to provide a better understanding of this application by illustrating examples.

[0023] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0024] Example 1: This embodiment discloses a fan control method for cooling different heat sources, wherein the fan is connected to a fan motor, and the fan speed is controlled by controlling the fan motor. In this embodiment, a PWM signal is used to control the fan speed.

[0025] In this embodiment, the relationship between the fan's PWM duty cycle and its speed is as follows: Figure 1 As shown, when the fan's PWM duty cycle input signal reaches 15%, the fan will start at the lowest speed (25% of the maximum speed), and when the fan's PWM duty cycle input signal reaches 90%, the fan will work at the maximum speed.

[0026] The fan control method in this embodiment includes steps S100, S200, S300, and S400, as follows: Figure 2 As shown.

[0027] Step S100: Collect the temperature of the heat source The temperature of the heat source can be collected via CAN bus or temperature sensor. In addition, the temperature of the heat source can also be collected by other means. In this embodiment, the heat source preferably includes a charger (OBC), an oil pump motor controller (MCU), and an oil pump motor (MOTER). That is, there are three heat sources in this embodiment. The fan is set to correspond to these three heat sources at the same time to cool down these three heat sources simultaneously.

[0028] Step S200: Obtain the PWM fan input duty cycle corresponding to different heat sources under the premise of meeting basic heat dissipation requirements. This specifically includes steps S210, S220, and S230. Preferably, steps S210, S220, and S230 are not performed in order. Figure 3 As shown.

[0029] Step S210: Obtain the PWM fan input duty cycle corresponding to the charger, as shown in Formula 1:

[0030] in, This indicates the PWM fan input duty cycle corresponding to the charger. This indicates the measured temperature of the charger; The original parameter represents the measured temperature of the charger. The original parameter refers to the value of the measured temperature, that is, the resolution is 1. For example, the value 65 represents 65℃. The 0.1% in Formula 1 can be understood as the resolution of the fan duty cycle, that is, the resolution is 0.1%. For example, 900 represents 90%.

[0031] In Formula 1, as follows Figure 4 As shown, when the charger temperature reaches 40℃, the PWM fan input duty cycle starts at the lowest speed with a 15% signal. When the charger temperature reaches 65℃, it operates at the maximum speed with a 90% signal. When the charger temperature is between 40℃ and 65℃, the PWM fan input duty cycle is linearly adjusted according to the charger temperature. In this embodiment, preferably, when... hour, ,when hour, .

[0032] Step S220: Obtain the PWM fan input duty cycle corresponding to the oil pump motor controller, as shown in Formula 2:

[0033] in, This indicates the PWM fan input duty cycle corresponding to the oil pump motor controller. This indicates the measured temperature of the oil pump motor controller; The original parameter represents the measured temperature of the oil pump motor controller. The original parameter refers to the value of the measured temperature, that is, the resolution is 1. For example, the value 65 represents 65℃. The 0.1% in Formula 2 can be understood as the resolution of the fan duty cycle, that is, the resolution is 0.1%. For example, 900 represents 90%.

[0034] In Formula 2, as Figure 5 As shown, when the oil pump motor controller temperature reaches 40℃, the PWM fan input duty cycle starts at the minimum speed with a 15% signal. When the oil pump motor controller temperature reaches 60℃, the PWM fan input duty cycle starts at the maximum speed with a 90% signal. When the oil pump motor controller temperature is between 40℃ and 60℃, the duty cycle is linearly adjusted according to the oil pump motor controller temperature. In this embodiment, preferably, when... hour, ;when hour, .

[0035] Step S230: Obtain the PWM fan input duty cycle corresponding to the oil pump motor, as shown in Formula 3:

[0036] in, This indicates the PWM fan input duty cycle corresponding to the oil pump motor. This indicates the measured temperature of the oil pump motor; The original parameter represents the measured temperature of the oil pump motor. The original parameter refers to the value of the measured temperature, that is, the resolution is 1. For example, the value 65 represents 65℃. The 0.1% in Formula 3 can be understood as the resolution of the fan duty cycle, that is, the resolution is 0.1%. For example, 900 represents 90%.

[0037] In Formula 3, as Figure 6 As shown, when the oil pump motor temperature reaches 40℃, the PWM fan input duty cycle starts at the minimum speed with a 15% signal; when the oil pump motor temperature reaches 80℃, the PWM fan input duty cycle starts at the maximum speed with a 90% signal. When the oil pump motor temperature is between 40℃ and 80℃, the duty cycle is linearly adjusted according to the oil pump motor temperature. Preferably, when... hour, ;when hour, .

[0038] Step S300: Select the maximum value of the PWM fan input duty cycle. Because the characteristics of the charger, oil pump motor controller, and oil pump motor are different, the temperature points at which the maximum speed is triggered for cooling these three individual heat sources are also different. Therefore, in this embodiment, the maximum value of the PWM fan input duty cycle is taken as the final value used to calculate the PWM fan output value. Specifically, the selection is made using Formula 4.

[0039]

[0040] In Formula 4, Real-time selection , and The maximum value in the value is used as the duty cycle input control signal for the PWM fan. The value range is [0, 900], representing a duty cycle of 0% to 90%.

[0041] Step S400: Input the maximum value of the duty cycle through the PWM fan. Calculate the PWM fan output value, and then control the fan motor using the PWM fan output value; Step S410, in order to prevent The sudden change ensures a smooth increase or decrease in fan speed, based on the calculated... The values ​​are processed using a ramp mechanism, where 3500ms (ms: milliseconds) represents the acceleration time and 1500ms represents the deceleration time. The acceleration and deceleration times can be adjusted in real-time as needed. Figure 7 As shown.

[0042] Step S420: Calculate the PWM fan output value and control the fan motor based on the PWM fan output value. In this embodiment, the PWM fan output value is defined according to the inherent characteristics of the PLC. The maximum value of the PWM output port is 65535, which corresponds to a voltage output of 24V (equal to the power supply voltage of the PLC).

[0043] This embodiment integrates the duty cycles of three heat sources to achieve one machine (fan motor) and three controls (charger / oil pump motor controller / oil pump motor). The fan motor adopts linear control and ramp control, which makes the start and stop smooth and avoids repeated start and stop, reducing motor noise and extending service life. The maximum speed can be reached at a maximum duty cycle of 90%, which reduces the energy consumption of the system.

[0044] Example 2: The difference between this embodiment two and embodiment one is that: Figure 8 As shown, when the PWM fan output value When the temperature exceeds a set threshold, the auxiliary cooling system is activated. The set threshold in this embodiment is determined based on actual needs, and the auxiliary cooling system can refer to existing electronic water pump cooling systems or other cooling systems.

[0045] This embodiment activates the auxiliary cooling system in a timely manner based on the PWM fan output value, and can activate dual cooling modes for special operating conditions to ensure heat dissipation efficiency.

[0046] Example 3: like Figure 9 As shown in the figure, this embodiment discloses a fan control system for heat dissipation from different heat sources. The fan control system includes a signal acquisition unit, a main control unit, and a fan motor.

[0047] The signal acquisition unit preferably has multiple temperature sensors, each corresponding to a heat source. In this embodiment, at least three temperature sensors are provided: the first temperature sensor is used to acquire the temperature of the charger, the second temperature sensor is used to acquire the temperature of the oil pump motor controller, and the third temperature sensor is used to acquire the temperature of the oil pump motor. Each temperature sensor is electrically connected to the main control unit.

[0048] The main control unit is preferably a PLC controller. The main control unit is equipped with the fan control method described in Embodiment 1 or Embodiment 2. The main control unit is electrically connected to the fan motor and controls the speed of the fan motor through the main control unit. When the main control unit of this embodiment is equipped with the fan control method described in Embodiment 2, the main control unit is also electrically connected to the auxiliary cooling system (electronic water pump cooling system).

[0049] The above description is merely a specific implementation of this application. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, modules, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here. It should be understood that the protection scope of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the protection scope of this application.

Claims

1. A fan control method for cooling different heat sources, characterized in that, include: Step S100: Collect temperature signals from different heat sources; Step S200: Obtain the PWM fan input duty cycle corresponding to different heat sources based on the temperature signal; Step S300: Based on all PWM fan input duty cycles, take the maximum value; Step S400: Calculate the PWM fan output value based on the maximum value of the PWM fan input duty cycle, and control the fan motor according to the PWM fan output value.

2. The fan control method according to claim 1, characterized in that, In step S100, the heat source includes a charger, an oil pump motor controller, and an oil pump motor.

3. The fan control method according to claim 2, characterized in that, Step S200 includes: Step S210: Obtain the PWM fan input duty cycle corresponding to the charger according to Formula 1. in, This indicates the PWM fan input duty cycle corresponding to the charger. This indicates the measured temperature of the charger; The original parameters representing the measured temperature of the charger; Step S220: Obtain the PWM fan input duty cycle corresponding to the oil pump motor controller according to Formula 2. in, This indicates the PWM fan input duty cycle corresponding to the oil pump motor controller. This indicates the measured temperature of the oil pump motor controller; The original parameters representing the measured temperature of the oil pump motor controller; Step S230: Obtain the PWM fan input duty cycle corresponding to the oil pump motor according to Formula 3. in, This indicates the PWM fan input duty cycle corresponding to the oil pump motor. This indicates the measured temperature of the oil pump motor; The original parameter represents the measured temperature of the oil pump motor.

4. The fan control method according to claim 3, characterized in that, In step S210, when hour, ; when hour, ; In step S220, when hour, ; when hour, ; In step S230, when hour, ; when hour, .

5. The fan control method according to claim 3 or 4, characterized in that, In step S300, the maximum value of the input duty cycle is obtained according to Formula 4; in, This indicates the maximum value of the PWM fan input duty cycle.

6. The fan control method according to claim 5, characterized in that, Step S400 includes: Step S410: Use a ramp function to ramp the maximum value of the PWM fan input duty cycle; Step S420: Calculate the PWM fan output value based on the maximum value of the PWM fan input duty cycle.

7. The fan control method according to claim 6, characterized in that, In step S410, the ramp processing is configured to have a predetermined acceleration time and deceleration time, with the acceleration time set to 3500 milliseconds and the deceleration time set to 1500 milliseconds.

8. The fan control method according to claim 6, characterized in that, In step S420, the PWM fan output value is calculated according to formula five; in, This indicates the PWM fan output value.

9. The fan control method according to claim 8, characterized in that, when When the temperature exceeds the set threshold, the auxiliary cooling system will be activated.

10. A fan control system for cooling different heat sources, characterized in that, include: The signal acquisition unit (100) is connected to the main control unit and is used to acquire temperature signals from different heat sources; The main control unit (200) is equipped with the fan control method according to any one of claims 1 to 9.

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