Cooling fan control method and system based on pd algorithm

Abstract

This invention discloses a cooling fan control method and system based on the PD algorithm. The method includes the following steps: acquiring the real-time temperature of the power battery; when the real-time temperature is detected to be greater than the cooling fan's enabling temperature, acquiring the power battery's operating time and outputting a cooling fan drive command; acquiring the power battery's temperature change and charging / discharging power after the operating time; acquiring a weighted input signal based on the charging / discharging power and the temperature change; acquiring a fan speed signal based on the PD algorithm and the weighted input signal; and controlling the cooling fan to operate based on the cooling fan drive command and the fan speed signal. This invention solves the problem that temperature-based cooling fan control methods fail to address the root cause of battery overheating, only achieving a regulating effect after the temperature rises above a suitable range, resulting in the battery still operating in an unsuitable temperature range for a considerable period.

Description

Technical Field

[0001] This invention relates to the field of power battery technology, and in particular to a cooling fan control method and system based on PD algorithm. Background Technology

[0002] When a power battery is charged and discharged with a high current, the battery heats up due to its internal resistance. This heat accumulates and is conducted outwards. When a temperature sensor detects an over-temperature signal, it triggers a cooling fan to cool the battery. However, since heat accumulation and conduction take time, by the time the temperature sensor detects the over-temperature signal, the temperature has already started to rise. Therefore, a cooling fan control strategy based solely on battery temperature has a certain lag, and the battery inevitably operates within an unsuitable temperature range for some time, negatively impacting battery performance and lifespan.

[0003] The existing cooling fan control method is mainly multi-level segmented control. The level control is based on the battery temperature range (for example, the battery operates at level 2 when the temperature is 30-40℃, and at level 3 when the temperature is 40-50℃. The larger the temperature range, the higher the level; the fan operates at levels 1, 2, and 3). This enables the cooling fan to work at different speeds, which is actually a proportional control and has low cooling efficiency. Summary of the Invention

[0004] The present invention provides a cooling fan control method and system based on PD algorithm, which solves the shortcomings of temperature-based cooling fan control methods that fail to address the root cause of battery heating and only have an adjustment effect after the temperature rises above the suitable range, resulting in the battery still operating in an unsuitable temperature range for a long time.

[0005] Firstly, a cooling fan control method based on the PD algorithm is provided, comprising the following steps:

[0006] The real-time temperature of the power battery is obtained. When the real-time temperature is detected to be greater than the cooling fan enable temperature, the power battery operating time is obtained and the cooling fan drive command is output.

[0007] The temperature change and charging / discharging power of the power battery after the operating time are obtained.

[0008] The weighted input signal is obtained based on the charging / discharging power and the temperature change.

[0009] Based on the PD algorithm, the fan speed signal is obtained according to the weighted input signal;

[0010] The cooling fan is controlled to operate according to the cooling fan drive command and the fan speed signal.

[0011] According to the first aspect, in a first possible implementation of the first aspect, the step of "obtaining the temperature change of the power battery after the operating time" specifically includes the following steps:

[0012] The temperature change ΔT of the power battery after operating for a preset time is obtained as follows:

[0013] ;

[0014] In the formula, R is the total resistance of the high-voltage circuit; r is the internal resistance of the battery; C is the specific heat capacity of the battery; m is the mass of the battery; t is the working time; and P is the charging and discharging power.

[0015] According to the first aspect, in a second possible implementation of the first aspect, the step of "obtaining the weighted input signal based on the charging / discharging power and the temperature change" specifically includes the following steps:

[0016] Based on the charging / discharging power P and the temperature change ΔT;

[0017] The weighted input signal x(t) is obtained as follows:

[0018] x(t) = k2ΔT + k3P;

[0019] In the formula, k2 is the temperature weighting coefficient; k3 is the power weighting coefficient.

[0020] According to the first aspect, in the third possible implementation of the first aspect, the PD algorithm is as follows:

[0021] ;

[0022] In the formula, k p For the proportional gain of the PD algorithm; T d This is the time constant of the PD algorithm's differential.

[0023] According to the first aspect, in the fourth possible implementation of the first aspect, the step of "obtaining the fan speed signal based on the PD algorithm and according to the weighted input signal" specifically includes the following steps:

[0024] Based on the PD algorithm u(t), according to the weighted input signal x(t);

[0025] The fan speed signal y(t) is obtained as follows:

[0026] ;

[0027] In the formula, .

[0028] According to the first aspect, in the fifth possible implementation of the first aspect, after the step of "obtaining the fan speed signal based on the PD algorithm and according to the weighted input signal", the following steps are specifically included:

[0029] The fan speed signal is filtered using the moving average filtering method.

[0030] According to the fifth possible implementation of the first aspect, in the sixth possible implementation of the first aspect, after the step of "filtering the fan speed signal based on the moving average filtering method", the following steps are specifically included:

[0031] A cooling control closed-loop transfer function is constructed based on the filtered fan speed signal to adjust the temperature change of the power battery.

[0032] According to the sixth possible implementation of the first aspect, in the seventh possible implementation of the first aspect, the step of "constructing a cooling control closed-loop transfer function based on the filtered fan speed signal to adjust the current battery temperature" specifically includes the following steps:

[0033] The fan speed signal y(t) is subjected to a Laplace transform to obtain the cooling control open-loop transfer function G(s) as follows:

[0034] ;

[0035] Based on the open-loop transfer function G(s) of the cooling control, the closed-loop transfer function A of the cooling control is constructed as follows:

[0036] ;

[0037] In the formula, s is the mapping from the preset working time t to the complex field; k is the fan cooling efficiency.

[0038] According to the first aspect, in the eighth possible implementation of the first aspect, after the step of "controlling the operation of the cooling fan according to the cooling fan drive command and the fan speed signal", the following steps are specifically included:

[0039] When the real-time temperature is detected to be lower than the cooling fan shutdown temperature, a cooling fan shutdown command is output.

[0040] Secondly, a cooling fan control system based on the PD algorithm is provided, comprising the following steps:

[0041] The drive command module is used to obtain the real-time temperature of the power battery. When the real-time temperature is detected to be greater than the cooling fan enable temperature, the module obtains the power battery working time and outputs the cooling fan drive command.

[0042] The temperature and power acquisition module is communicatively connected to the drive command module and is used to acquire the temperature change and charging / discharging power of the power battery after the working time.

[0043] An input signal module is communicatively connected to the temperature and power acquisition module, and is used to acquire a weighted input signal based on the charging and discharging power and the temperature change.

[0044] A fan speed signal module, which is communicatively connected to the input signal module, is used to obtain the fan speed signal based on the PD algorithm and the weighted input signal.

[0045] The fan operation control module is communicatively connected to the drive command module and the fan speed signal module, and is used to control the operation of the cooling fan according to the cooling fan drive command and the fan speed signal.

[0046] Compared with the prior art, the advantages of the present invention are as follows: the introduction of battery charging and discharging power to participate in the regulation of battery temperature solves the problem that the temperature-based cooling fan control method fails to address the root cause of battery heating and only has a regulating effect after the temperature rises above the suitable range, resulting in the battery still operating in the unsuitable temperature range for a long time. Therefore, the speed of battery temperature regulation can be improved. Attached Figure Description

[0047] Figure 1 This is a flowchart illustrating an embodiment of a cooling fan control method based on the PD algorithm of the present invention.

[0048] Figure 2 This is a flowchart illustrating another embodiment of a cooling fan control method based on the PD algorithm of the present invention.

[0049] Figure 3 This is a schematic diagram comparing the control effects of the PD algorithm and the proportional algorithm of the present invention;

[0050] Figure 4 This is a schematic diagram illustrating the battery temperature control effect of the PD algorithm of the present invention;

[0051] Figure 5 This is a schematic diagram of a cooling fan control system based on the PD algorithm according to the present invention. Detailed Implementation

[0052] Referring now to specific embodiments of the invention, examples of which are illustrated in the accompanying drawings. Although the invention will be described in conjunction with specific embodiments, it will be understood that it is not intended to limit the invention to the described embodiments. Rather, it is intended to cover variations, modifications, and equivalents included within the spirit and scope of the invention as defined by the appended claims. It should be noted that the method steps described herein can be implemented by any functional block or functional arrangement, and any functional block or functional arrangement can be implemented as a physical entity or a logical entity, or a combination of both.

[0053] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0054] Note: The examples described below are merely specific examples and are not intended to limit the embodiments of the present invention to the specific steps, values, conditions, data, order, etc. Those skilled in the art can utilize the concept of the present invention to construct more embodiments not mentioned herein by reading this specification.

[0055] See Figure 1 As shown, this embodiment of the invention provides a cooling fan control method based on the PD algorithm, applied to a PD controller, including the following steps:

[0056] S100: Obtain the real-time temperature of the power battery. When the real-time temperature is detected to be greater than the cooling fan enable temperature, obtain the power battery operating time and output the cooling fan drive command.

[0057] S200, acquire the temperature change and charging / discharging power of the power battery after the operating time;

[0058] S300, obtain the weighted input signal based on the charging / discharging power and the temperature change;

[0059] S400, based on the PD algorithm, obtains the fan speed signal according to the weighted input signal;

[0060] S500 controls the operation of the cooling fan according to the cooling fan drive command and the fan speed signal.

[0061] Specifically, in this embodiment, the control objective of the cooling fan is to ensure that the power battery operates within its optimal temperature range (20℃-30℃), with battery temperature being the controlled object. Battery temperature is influenced by both charging / discharging power and ambient temperature, resulting from the combined effects of internal and external factors. Therefore, this invention uses battery temperature and charging / discharging power as input signals to construct a closed-loop control system. When the real-time temperature is detected to be higher than the cooling fan's activation temperature, the cooling fan is triggered to start, and the cooling fan speed is determined based on the battery temperature and charging / discharging power. The greater the deviation of the battery temperature from the optimal temperature range or the higher the battery charging / discharging power, the higher the required fan speed. Therefore, a proportional element needs to be added to the cooling fan speed control algorithm.

[0062] Since battery charging and discharging power is the root cause of battery heat generation, controlling the cooling fan speed based on battery charging and discharging power reduces the time for battery heat accumulation and conduction compared to control methods based solely on temperature, thus improving the system's response speed.

[0063] Meanwhile, the cooling fan control method proposed in this invention has universality and can be applied not only to the thermal management system of power batteries, but also to the temperature control system of equipment such as motor controllers, motors, DC step-down converters, and high-voltage distribution boxes.

[0064] Therefore, this invention proposes a cooling fan control method based on the PD algorithm, which introduces the battery charging and discharging power to participate in the regulation of battery temperature. This solves the problem that the temperature-based cooling fan control method fails to address the root cause of battery heating and only has a regulating effect after the temperature rises above the suitable range, resulting in the battery still operating in an unsuitable temperature range for a long time. Therefore, it can improve the speed of battery temperature regulation.

[0065] Preferably, in another embodiment of this application, the step of "S200, obtaining the temperature change of the power battery after the operating time" specifically includes the following steps:

[0066] The temperature change ΔT of the power battery after operating for a preset time is obtained as follows:

[0067] ;

[0068] In the formula, R is the total resistance of the high-voltage circuit; r is the internal resistance of the battery; C is the specific heat capacity of the battery; m is the mass of the battery; t is the working time; and P is the charging and discharging power.

[0069] Specifically, in this embodiment,

[0070] Assume the charging and discharging power of the power battery is: P = I 2 R

[0071] The average heat generation power of the battery is:

[0072] ;

[0073] When the detected real-time temperature exceeds the cooling fan's enable temperature, a cooling fan drive command is output. Therefore, the cooling fan enable temperature T0 is used as a reference, and ΔT represents the temperature change above T0, which is the temperature error signal. During the battery's operating time t, the battery temperature change is:

[0074] ;

[0075] As can be seen from the above formula, the change in battery temperature ΔT is directly proportional to the integral of the battery's charging and discharging power.

[0076] Preferably, in another embodiment of this application, the step "S300, obtaining a weighted input signal based on the charging / discharging power and the temperature change" specifically includes the following steps:

[0077] Based on the charging / discharging power P and the temperature change ΔT;

[0078] The weighted input signal x(t) is obtained as follows:

[0079] x(t) = k2ΔT + k3P;

[0080] In the formula, k2 is the temperature weighting coefficient; k3 is the power weighting coefficient.

[0081] Specifically, in this embodiment, since the temperature and power signal data ranges are different, the temperature and power need to be scaled and weighted. k2 is the temperature weighting coefficient; k3 is the power weighting coefficient.

[0082] Battery temperature and charge / discharge power signals are collected, and the battery temperature and charge / discharge power are scaled and weighted. Then, they are summed as the weighted input signal. When the real-time battery temperature is lower than the cooling fan enable temperature T0, ΔT = 0; when it is higher than a certain value (let's say T1), ΔT = T1 - T0, and the cooling fan maintains maximum speed. Therefore, parameter k2 in the model is a piecewise function of ΔT. Similarly, k3 is a piecewise function of power P. Parameters k2 and k3 are set in the model using a lookup table method.

[0083] Preferably, in another embodiment of this application, the PD algorithm is as follows:

[0084] ;

[0085] In the formula, k p For the proportional gain of the PD algorithm; T d This is the time constant of the PD algorithm's differential.

[0086] Specifically, in this embodiment, since both battery temperature and power can be considered as non-periodic signals with a frequency of 0, the amplitude-frequency characteristic of the differentiating element is 0, and it does not amplify the input signal. Therefore, parameter k... p Determined by the maximum value of the input signal and the maximum value of the fan speed; parameter T d Configuration can be tested on the entire vehicle.

[0087] Preferably, in another embodiment of this application, the step "S400, based on the PD algorithm, and obtaining the fan speed signal according to the weighted input signal" specifically includes the following steps:

[0088] Based on the PD algorithm u(t), according to the weighted input signal x(t);

[0089] The fan speed signal y(t) is obtained as follows:

[0090] ;

[0091] In the formula, .

[0092] Specifically, in this embodiment, the control law of the PD controller (PD algorithm) is as follows:

[0093]

[0094] The output fan speed signal is:

[0095] .

[0096] Preferably, in another embodiment of this application, after the step "S400, based on the PD algorithm, and obtaining the fan speed signal according to the weighted input signal", the following steps are specifically included:

[0097] S600 filters the fan speed signal based on the moving average filtering method.

[0098] Specifically, in this embodiment, the fan speed signal is filtered to eliminate the spike pulses generated by the differential link of the PD controller when the power changes due to the turning on or off of electrical equipment, making the fan control signal smoother. The sliding mean filtering method is used in this model.

[0099] Moving average filtering involves first creating a data buffer in RAM to store N sampled data points sequentially. Each time a new data point is sampled, the earliest sampled data point is discarded. Then, the arithmetic or weighted average of the N data points, including the new data point, is calculated. In this way, a new average can be calculated with each sampling, thus speeding up data processing.

[0100] Preferably, in another embodiment of this application, after the step "S600, filtering the fan speed signal based on the moving average filtering method", the following steps are specifically included:

[0101] S700 constructs a cooling control closed-loop transfer function based on the filtered fan speed signal to adjust the temperature change of the power battery.

[0102] Preferably, in another embodiment of this application, the step "S700, constructing a cooling control closed-loop transfer function based on the filtered fan speed signal to adjust the current battery temperature" specifically includes the following steps:

[0103] The fan speed signal y(t) is subjected to a Laplace transform to obtain the cooling control open-loop transfer function G(s) as follows:

[0104] ;

[0105] Based on the open-loop transfer function G(s) of the cooling control, the closed-loop transfer function A of the cooling control is constructed as follows:

[0106] ;

[0107] In the formula, s is the mapping from the preset working time t to the complex domain; k is the fan cooling efficiency, and the feedback coefficient k is the coefficient between the fan speed and the cooling effect.

[0108] Specifically, in this embodiment, see Figure 2 As shown, when using the proportional control method for the cooling fan, the proportional control method uses a lookup table to control the cooling fan speed to be proportional to the battery temperature, and has the function of stepless speed regulation. The cooling efficiency of the proportional control method is higher than that of the gear speed regulation, but it does not have the function of advance adjustment and cannot react in advance to the temperature change trend.

[0109] Therefore, to address the aforementioned issues, the cooling fan's speed response should be rapid and proactive, capable of predicting changes in battery temperature and charging / discharging power to minimize settling time. Thus, the fan speed control algorithm needs to incorporate a derivative element. Since the control objective of this scheme does not require the battery to operate at a precise temperature point, but rather within a temperature range, allowing for a certain degree of steady-state error, an integral element is unnecessary. Considering the characteristics of the aforementioned control objectives, this invention employs a proportional-derivative (PD) control algorithm. The temperature control system using the PD algorithm can introduce an advance correction signal based on the rate of change of battery temperature and power, improving the response speed to temperature changes and reducing settling time.

[0110] from Figure 2As can be seen, after the process from the input signal (the combination of temperature and power) to the fan speed signal, the impact of the fan speed on the input signal, causing it to decrease (temperature decreases), has not yet been considered. Therefore, a negative feedback loop needs to be added from the output signal (fan speed) to the input signal (temperature) to achieve the effect of temperature reduction. Now, considering the factor that the output signal reduces the input signal, the entire system becomes a closed loop. The input affects the output, and the output, in turn, affects the input, thus yielding the closed-loop transfer function.

[0111] Preferably, in another embodiment of this application, after the step "S500, controlling the operation of the cooling fan according to the cooling fan drive command and the fan speed signal", the following steps are specifically included:

[0112] S800: When the real-time temperature is detected to be lower than the cooling fan shutdown temperature, a cooling fan shutdown command is output.

[0113] Specifically, in this embodiment, a cooling fan enable signal is determined. When the real-time battery temperature is greater than 30°C, the cooling fan is enabled, and when the temperature is lower than 25°C, the cooling fan is turned off. The 25-30°C range can be called the hysteresis range, which aims to improve system stability (avoiding damage caused by frequent fan on / off cycles).

[0114] This invention provides a cooling fan control method based on the PD algorithm. During model simulation, k2 = 0.056 and k3 = 0.0017 are set; then, they are summed as the input signal to the PD controller. The parameter k in the PD controller... p Set to 2, parameter T D We set the power efficiency to 0.5; simultaneously, we built a simplified heat dissipation model using a state machine, ignoring natural heat dissipation, with the battery heat dissipation efficiency being 0.0001 times the power and the fan heat dissipation efficiency k being 0.001 times the fan speed; after the model was built, we input a limited-amplitude sine wave to simulate the power signal and compared the battery temperature trend after cooling as follows: Figure 3 As shown.

[0115] At the same time, a fan control model using the proportional control method was built. Except for the control method, all other parameters were the same. Temperature curves for both control methods can be found in [reference needed]. Figure 4 As shown.

[0116] The comparison shows that the temperature control system based on battery power and temperature and using PD algorithm can adjust the temperature in advance according to the power, the fan speed response is faster, the temperature adjustment time is shorter, and the battery can work within the suitable temperature range more often. Therefore, the feasibility and superiority of the present invention are verified.

[0117] See also Figure 5As shown in the figure, a cooling fan control system based on the PD algorithm provided by an embodiment of the present invention includes the following steps:

[0118] The drive command module is used to obtain the real-time temperature of the power battery. When the real-time temperature is detected to be greater than the cooling fan enable temperature, the module obtains the power battery working time and outputs the cooling fan drive command.

[0119] The temperature and power acquisition module is communicatively connected to the drive command module and is used to acquire the temperature change and charging / discharging power of the power battery after the working time.

[0120] An input signal module is communicatively connected to the temperature and power acquisition module, and is used to acquire a weighted input signal based on the charging and discharging power and the temperature change.

[0121] A fan speed signal module, which is communicatively connected to the input signal module, is used to obtain the fan speed signal based on the PD algorithm and the weighted input signal.

[0122] The fan operation control module is communicatively connected to the drive command module and the fan speed signal module, and is used to control the operation of the cooling fan according to the cooling fan drive command and the fan speed signal.

[0123] Therefore, this invention proposes a cooling fan control method based on battery temperature and charging / discharging power, using a PD algorithm. This method introduces battery charging / discharging power into the regulation of battery temperature, addressing the root cause of battery heating, thereby improving the speed and predictability of battery temperature regulation.

[0124] The control objective of the cooling fan is to ensure that the power battery operates within its optimal temperature range (20℃-30℃), with battery temperature being the controlled object. Battery temperature is influenced by both charging / discharging power and ambient temperature, resulting from the combined effects of internal and external factors. Therefore, this invention uses battery temperature and charging / discharging power as input signals to construct a closed-loop control system. When the detected real-time temperature exceeds the cooling fan's activation temperature, the cooling fan is triggered to start, and its speed is determined based on the battery temperature and charging / discharging power. The greater the deviation of the battery temperature from the optimal temperature range or the higher the battery charging / discharging power, the higher the required fan speed. Therefore, a proportional element needs to be added to the cooling fan speed control algorithm. Simultaneously, the cooling fan's speed response should be fast and proactive, capable of predicting changes in battery temperature and charging / discharging power to minimize adjustment time. Therefore, a derivative element needs to be added to the fan speed control algorithm. Since the control objective of this scheme does not require the battery to operate at a precise temperature point but rather within a temperature range, allowing for a certain steady-state error, an integral element is not needed. Considering the characteristics of the above control objectives, this invention employs a proportional-derivative (PD) control algorithm.

[0125] Specifically, this embodiment corresponds one-to-one with the above method embodiments. The functions of each module have been described in detail in the corresponding method embodiments, so they will not be repeated here.

[0126] Based on the same inventive concept, embodiments of this application also provide a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements all or part of the method steps of the above method.

[0127] The present invention can implement all or part of the processes in the above methods, or it can be accomplished by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable file, or some intermediate form. The computer-readable medium can include: any entity or device capable of carrying computer program code, recording media, USB flash drive, portable hard drive, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc. It should be noted that the content included in the computer-readable medium can be appropriately added or removed according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, the computer-readable medium does not include electrical carrier signals and telecommunication signals.

[0128] Based on the same inventive concept, embodiments of this application also provide an electronic device, including a memory and a processor. The memory stores a computer program that runs on the processor. When the processor executes the computer program, it implements all or part of the method steps described above.

[0129] The processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor. The processor is the control center of the computer device, connecting all parts of the computer device through various interfaces and lines.

[0130] Memory can be used to store computer programs and / or modules. The processor performs various functions of the computer device by running or executing the computer programs and / or modules stored in the memory, and by accessing data stored in the memory. Memory can primarily include a program storage area and a data storage area. The program storage area can store the operating system and at least one application program required for a function (e.g., sound playback, image playback, etc.); the data storage area can store data created based on the use of the mobile phone (e.g., audio data, video data, etc.). Furthermore, memory can include high-speed random access memory, and can also include non-volatile memory, such as hard disks, RAM, plug-in hard disks, SmartMedia Cards (SMC), Secure Digital (SD) cards, Flash Cards, at least one disk storage device, flash memory device, or other volatile solid-state storage devices.

[0131] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, servers, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage and optical storage) containing computer-usable program code.

[0132] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), servers, and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0133] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0134] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0135] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A cooling fan control method based on a PD algorithm, characterized by, The method comprises the following steps: acquiring a real-time temperature of the power battery, and acquiring a working time of the power battery and outputting a cooling fan driving instruction when it is detected that the real-time temperature is greater than a cooling fan enabling temperature; acquiring a temperature variation of the power battery after the working time and a charge-discharge power; acquiring a weighting input signal according to the charge-discharge power and the temperature variation; acquiring a fan rotating speed signal according to the weighting input signal based on a PD algorithm; controlling the cooling fan to operate according to the cooling fan driving instruction and the fan rotating speed signal; The step of acquiring the temperature variation of the power battery after the working time specifically comprises the following steps: Obtaining a temperature variation of a power battery after a preset working time As follows: ； wherein R is a total resistance of a high-pressure loop, r is a battery internal resistance, C is a battery specific heat capacity, m is a battery mass, t is the working time, and P is the charge-discharge power; The step of acquiring the weighting input signal according to the charge-discharge power and the temperature variation specifically comprises the following steps: According to the charge-discharge power P and the temperature change amount ; Obtaining an empowerment input signal As follows: ； wherein T is a temperature weight coefficient; P is a power weight coefficient; The PD algorithm is as follows: ； wherein is the PD algorithm proportional term gain; is the PD algorithm derivative time constant; The step of acquiring the fan rotating speed signal according to the weighting input signal based on the PD algorithm specifically comprises the following steps: Based on the PD algorithm , according to the weighted input signal ; Acquiring a fan rotation speed signal As follows: ； In the formulae, .

2. The PD algorithm-based cooling fan control method of claim 1, wherein, After the step of acquiring the fan rotating speed signal according to the weighting input signal based on the PD algorithm, the following step is specifically included: filtering the fan rotating speed signal based on a sliding mean filtering method.

3. The PD algorithm-based cooling fan control method according to claim 2, wherein, After the step of filtering the fan rotating speed signal based on the sliding mean filtering method, the following step is specifically included: constructing a cooling control closed-loop transfer function according to the filtered fan rotating speed signal to adjust the temperature variation of the power battery.

4. The PD algorithm-based cooling fan control method according to claim 3, wherein, The step of constructing the cooling control closed-loop transfer function according to the filtered fan rotating speed signal to adjust the current battery temperature specifically comprises the following steps: The fan speed signal is converted to a digital signal A Laplace transform is performed to obtain a cooling control open loop transfer function As follows: ； According to the cooling control open-loop transfer function The cooling control closed-loop transfer function A is constructed as follows: ； wherein s is a mapping of a preset working time t to a complex domain, and k is a fan heat dissipation efficiency.

5. The PD algorithm-based cooling fan control method of claim 1, wherein, After the step of controlling the cooling fan to operate according to the cooling fan driving instruction and the fan rotating speed signal, the following step is specifically included: outputting a cooling fan shutdown instruction when it is detected that the real-time temperature is less than a cooling fan shutdown temperature.

6. A cooling fan control system based on a PD algorithm, characterized by, The method comprises the following steps: a driving instruction module, configured to acquire a real-time temperature of the power battery, and acquire a working time of the power battery and output a cooling fan driving instruction when it is detected that the real-time temperature is greater than a cooling fan enabling temperature; a temperature power acquisition module, in communication connection with the driving instruction module, configured to acquire a temperature variation of the power battery after the working time and a charge-discharge power; an input signal module, in communication connection with the temperature power acquisition module, configured to acquire a weighting input signal according to the charge-discharge power and the temperature variation; a fan rotating speed signal module, in communication connection with the input signal module, configured to acquire a fan rotating speed signal according to the weighting input signal based on a PD algorithm; a control fan operation module, in communication connection with the driving instruction module and the fan rotating speed signal module, configured to control the cooling fan to operate according to the cooling fan driving instruction and the fan rotating speed signal; The step of obtaining the temperature change amount of the power battery after the working time comprises the following steps: Obtaining a temperature variation of a power battery after a preset working time As follows: ； In the formula, R is the total resistance of the high-pressure circuit; r is the internal resistance of the battery; C is the specific heat capacity of the battery, m is the mass of the battery; t is the working time; and P is the charging and discharging power. The step of obtaining the weighting input signal according to the charging and discharging power and the temperature change amount comprises the following steps: According to the charge-discharge power P and the temperature change amount ; Obtaining an empowerment input signal As follows: ； wherein is a temperature weight coefficient; is a power weight coefficient; The PD algorithm is as follows: ； wherein is the PD algorithm proportional term gain; is the PD algorithm derivative time constant; The step of obtaining the fan rotating speed signal based on the PD algorithm and according to the weighting input signal comprises the following steps: Based on the PD algorithm , according to the weighted input signal ; Acquiring a fan rotation speed signal As follows: ； In the formulae, .

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