Wading control method for electronic fan

Abstract

The invention relates to an electronic fan wading control method which comprises the following steps: determining a target rotating speed according to the actual wading depth and current torque feedback of an electronic fan when a vehicle wades, and reducing the rotating speed of the electronic fan to the target rotating speed. Therefore, by reducing the rotating speed of the electronic fan during wading, the problems that the fan blades are damaged or deformed and the battery motor stops working due to high-speed wading of the fan blades are solved, protection of the electronic fan during wading is achieved, and the running reliability of a vehicle during wading can be effectively improved.

Description

Technical Field

[0001] The invention relates to the technical field of automobile engine cooling systems, and in particular to a water wading control method for an electronic fan. Background Art

[0002] New energy vehicles on the market can be divided into fuel cell, pure electric and other types of vehicles. Hydrogen fuel cell vehicles convert chemical energy into electrical energy to drive the vehicle through the chemical reaction of hydrogen and oxygen; pure electric vehicles directly provide electrical energy to the vehicle through the charging and discharging of the battery pack. Compared with traditional internal combustion engine vehicles, new energy vehicles have eliminated the core parts of internal combustion engine vehicles - the engine. Due to the lack of mechanical energy provided by the engine, traditional cooling electronic fans such as direct-connected electronic fans, electromagnetic clutch electronic fans and silicone oil clutch electronic fans cannot be used. Instead, electronic fans are used. Therefore, in new energy vehicles, the core of the cooling system is the radiator and a group of electronic fans.

[0003] As new energy vehicle models become more and more popular, electronic fans are used more and more widely, and various brands of electronic fans on the market are booming. With the increase in vehicle power consumption, the heat dissipation demand of the cooling system is also increasing. The number of electronic fans arranged on a single radiator is also increasing, and the arrangement of electronic fans is becoming more and more dense. The failure rate of electronic fans in the after-sales market is also increasing year by year. This is particularly obvious for new energy commercial vehicles, because the working conditions of commercial vehicles are relatively harsh. For example, long-term work without stopping, dust, and vehicle wading will reduce the service life of electronic fans.

[0004] The water-related issue has put forward more stringent requirements for electronic fans: on the one hand, if water enters the motor, it will directly cause the motor to short-circuit and shut down, affecting the end-user experience; on the other hand, when the fan blades move at high speed and cut through the water surface, the fan blades will be subjected to excessive torque, causing damage or deformation of the fan blades. At present, most electronic fan manufacturers will strengthen the waterproof level of the electronic fan itself to deal with the water-related issue, but this will incur additional design costs, and the production cost of the electronic fan will be further increased, which is not conducive to the competitiveness of the product. Summary of the invention

[0005] In order to solve the above problems, the present invention provides an electronic fan wading control method, which reduces the rotation speed of the electronic fan when the vehicle is wading to avoid damage to the fan blades.

[0006] The technical solution adopted by the present invention is: a water wading control method for an electronic fan, characterized in that it comprises the following steps: S1. Obtaining the wading depth H of the electronic fan when the vehicle is wading; S2. Obtain the actual torque T of the electronic fan when the vehicle is wading. When the actual torque T≥αTn, adjust the target speed of the electronic fan according to the wading depth H; when the actual torque T<αTn, the electronic fan continues to run at the original input speed n; where: H is the wading depth of the electronic fan; T is the actual torque; Tn is the theoretical torque at the input speed n of the electronic fan; α is the theoretical torque excess coefficient; n is the actual input speed of the electronic fan; S3. When the actual torque T≥αTn and 0≤H≤A, the target speed n1 of the wading electronic fan is regulated, n1=an; When the actual torque T≥αTn and A<H≤B, the target speed n1 of the wading electronic fan is regulated, n1=bn; When the actual torque T≥αTn and H>B, the target speed n1 of the wading electronic fan is regulated, n1=cn, where: a, b, c are constants; A and B are the wading depth values ​​of the electronic fan.

[0007] Preferably, α is 125%.

[0008] Preferably, A is 1 / 3R, B is 2 / 3R, and R is the radius of the water-carrying electronic fan.

[0009] Preferably, a is 75%, b is 25%, and c is 0.

[0010] Preferably, a liquid level sensor is installed on the electronic fan, and the water depth of the electronic fan is H=h1-h2, where h1 is the distance between the liquid level sensor and the wading liquid surface, and h2 is the distance between the liquid level sensor and the lower edge of the electronic fan blade.

[0011] Preferably, when there are x electronic fans on a single radiator, assuming that the speed of y electronic fans is reduced by a total of z% due to water wading protection, the speed of each electronic fan is increased by z% / (xy) by increasing the speed of the (xy) non-water wading electronic fans, thereby compensating for the reduction in air volume and heat dissipation, thereby further ensuring that the vehicle cooling equipment operates within a preset high-performance range.

[0012] The beneficial effects achieved by the present invention are: according to the actual wading depth of the electronic fan when the vehicle is wading and the current torque feedback, the target speed is determined, and the speed of the electronic fan is reduced to the target speed, thereby avoiding problems such as fan blade damage or deformation caused by high-speed wading and battery motor stopping working, thereby protecting the electronic fan when wading, and effectively improving the operating reliability of the vehicle when wading. The present invention has the following advantages: 1. A control strategy for the electronic fan during wading is established. The wading condition can be comprehensively judged based on the wading depth and torque feedback of the electronic fan. A lower target speed is finally given to reduce the speed of the electronic fan, reduce the risk of blade damage or deformation, and extend the service life of the electronic fan. 2. Provide a new idea for electronic fan manufacturers. In the face of the water-wading problem of the whole vehicle, in addition to continuously strengthening the waterproof level of the electronic fan body, the water-wading control strategy can also be used to reduce or even shut down the relevant electronic fans to avoid the impact of water-wading on the use of electronic fans; 3. In new energy cooling systems, a single radiator often needs to be equipped with multiple electronic fans. Through this water-wading control strategy, when the speed of some electronic fans is reduced due to water-wading protection, the speed of other non-water-wading electronic fans can be increased to maintain the overall air volume and heat dissipation of the electronic fan group, thereby further ensuring that the vehicle's pure electric battery or fuel cell and other heat-dissipating devices work in a high-performance range and ensure the vehicle's superior performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a schematic diagram of the electronic fan structure; Figure 2 This is a schematic diagram of the electronic fan thermal management system; Figure 3 A control principle diagram of the electronic fan wading control method of the present invention; Figure 4 This is an example diagram of the position of an electronic fan in a wading scene; Figure 5 Schematic diagram of using multiple electronic fans for a single heat sink; In the figure: 1.1, electronic fan; 1.2, radiator; 1.3, electronic fan control harness; 1.4, electronic fan power harness; 1.5, vehicle VCU; 1.6, vehicle power supply (battery / fuel cell); 1.7, device to be cooled; 1.8, electronic fan bracket; 2.1, fan blades; 2.2, motor; 2.3, controller. DETAILED DESCRIPTION

[0014] The present invention will be further described below in conjunction with the accompanying drawings.

[0015] like Figure 1-4 As shown, an electronic fan wading control method of the present invention can be applied to the thermal management system of new energy vehicles.

[0016] Combination Figure 1As shown, the thermal management system includes an electronic fan 1.1, a radiator 1.2, an electronic fan control harness 1.3, an electronic fan power harness 1.4, a vehicle VCU 1.5, a vehicle power supply (battery / fuel cell) 1.6 and a device to be cooled 1.7, wherein: the electronic fan 1.1 is mounted on the radiator 1.2 through an electronic fan bracket 1.8, and the electronic fan 1.1 has two power supply lines, one is a large current power supply provided by the vehicle power supply 1.6 and the electronic fan power harness 1.4, which is used to drive the electronic fan; the other is a small current control signal provided by the vehicle VCU 1.5 and the electronic fan control harness 1.4, which provides the electronic fan 1.1 with a set speed and collects the feedback signal of the electronic fan 1.1. Through the above two lines, the electronic fan 1.1 can provide air volume to the radiator 1.2, and combined with the heat exchange inside the radiator 1.2, the device to be cooled 1.7 is cooled.

[0017] The vehicle VCU 1.5 obtains the heat dissipation demand of the device to be cooled 1.7, combines the preset program inside the VCU 1.5, outputs the target speed of the electronic fan and sends the required speed signal through the electronic fan control harness 1.3; the vehicle power supply (battery / fuel cell) 1.6 is the energy source, which supplies power to the electronic fan 1.1 to ensure that it moves at the target speed. The vehicle power supply 1.6 will transfer electrical energy to the electronic fan 1.1 through the large-diameter electronic fan power harness 1.4.

[0018] Heat dissipation equipment 1.7 includes, but is not limited to, battery packs, battery stacks, fuel cells, hydrogen storage tanks, vehicle motors, in-vehicle air conditioners and other high-power components.

[0019] Combination Figure 2 As shown, the electronic fan 1.1 includes: a fan blade 2.1, a motor 2.2, and a controller 2.3. In this example, the motor 2.2 and the controller 2.3 are of an integrated design, but of course the motor 2.2 and the controller 2.3 can also be of a split design, which is not specifically limited.

[0020] Combination Figure 3 As shown, a water wading control method for an electronic fan of the present invention comprises the following steps: S1. Obtaining the wading depth H of the electronic fan when the vehicle is wading; S2. Obtain the actual torque T of the electronic fan when the vehicle is wading. When the actual torque T≥αTn, adjust the target speed of the electronic fan according to the wading depth H; when the actual torque T<αTn, the electronic fan continues to run at the original input speed n; where: H is the wading depth of the electronic fan; T is the actual torque; Tn is the theoretical torque at the input speed n of the electronic fan; α is the theoretical torque excess coefficient; n is the actual input speed of the electronic fan; S3. When the actual torque T≥αTn and 0≤H≤A, the target speed n1 of the wading electronic fan is regulated, n1=an; When the actual torque T≥αTn and A<H≤B, the target speed n1 of the wading electronic fan is regulated, n1=bn; When the actual torque T≥αTn and H>B, the target speed n1 of the wading electronic fan is regulated, n1=cn, where: a, b, c are constants; A and B are the wading depth values ​​of the electronic fan.

[0021] In a specific embodiment, a water wading control method for an electronic fan includes the following steps: 1. First, confirm the speed requirement n of 1.1 given to the electronic fan by the whole vehicle before wading. When the vehicle starts to wade, obtain the actual wading depth H of the electronic fan and the torque T of the electronic fan when the vehicle wades.

[0022] The actual wading depth H of the electronic fan when the vehicle is wading includes: obtaining the actual distance h1 detected by the wading liquid level detection sensor from the electronic fan to the wading liquid surface; and calculating the actual wading depth H of the electronic fan according to the actual distance h1 and the distance h2 between the wading liquid level detection sensor and the lower edge of the electronic fan blade.

[0023] For example, Figure 4 As shown, where: h1 is the distance between the liquid level sensor and the wading liquid surface, h2 is the distance between the liquid level sensor and the lower edge of the electronic fan blade, H is the wading depth of the electronic fan, R is the radius of the electronic fan blade, and the wading depth of the blade H = h1-h2.

[0024] 2. By determining that the wading depth H ≥ 0, the actual wading state of the electronic fan when wading is obtained, and it is determined whether the electronic fan is wading. If not, the electronic fan continues to run at the original input speed n.

[0025] When the electronic fan is wading, the actual torque feedback signal of the fan is obtained. When the actual torque T≥125%Tn, the electronic fan is judged to be actually wading, and the electronic fan enters the wading protection and reduces the speed of the electronic fan; when the actual torque T<125%Tn, the electronic fan is judged not to be actually wading, and the electronic fan continues to run at the original input speed n (to avoid misjudgment due to splashing of the electronic fan); where: Tn is the theoretical torque at the fan input speed n, and the formula of Tn is motor rated power * 9550 / n. The torque judgment point in this example is 125% of the rated load, and 125% can be adjusted according to the vehicle platform. This value must be set reasonably to avoid the fan liquid level sensor being affected by external influences such as splashing water, which causes torque increase, thereby causing misjudgment.

[0026] 3. When the electronic fan is wading, when the actual torque T≥125%Tn, it is determined that the electronic fan is actually wading; further, the corresponding relationship between the wading depth H and the target speed n1 is determined according to the actual wading depth range when the vehicle is wading: When 0≤H≤1 / 3R, the target speed n1=75%n for water wading protection of the electronic fan is determined; When 1 / 3R≤H≤2 / 3R, the target speed n1=25%n for water wading protection of the electronic fan is determined; When H>2 / 3R, it is determined that the target speed n1=0 for water wading protection of the electronic fan can be performed.

[0027] The present invention determines the target rotation speed of the electronic fan for entering the wading protection under the current situation according to the actual wading depth of the vehicle and the torque feedback signal, laying a foundation for the subsequent timely control of the rotation speed of the electronic fan.

[0028] like Figure 5 As shown, when there are x electronic fans on a single radiator, assuming that the speed of y electronic fans is reduced by a total of z% due to water wading protection, the speed of each electronic fan is increased by z% / (xy) through the increase of the speed of (xy) non-water wading electronic fans, compensating for the decrease in air volume and heat dissipation, thereby further ensuring that the vehicle cooling equipment operates in the preset high-performance range.

[0029] The above shows and describes the basic principles and main structural features of the present invention. The present invention is not limited to the above examples. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A water wading control method for an electronic fan, characterized in that: The following steps are involved: S1. Obtaining the wading depth H of the electronic fan when the vehicle is wading; S2. Obtaining the actual torque T of the electronic fan when the vehicle is wading. When the actual torque T≥αTn, adjusting the target speed of the electronic fan according to the wading depth H; When the actual torque T<αTn, the electronic fan continues to run at the original input speed n; where: H is the wading depth of the electronic fan; T is the actual torque; Tn is the theoretical torque when the electronic fan input speed n; α is the theoretical torque excess coefficient; n is the actual input speed of the electronic fan; S3. When the actual torque T≥αTn and 0≤H≤A, the target speed n1 of the wading electronic fan is regulated, n1=an; When the actual torque T≥αTn and A<H≤B, the target speed n1 of the wading electronic fan is regulated, n1=bn; When the actual torque T≥αTn and H>B, the target speed n1 of the wading electronic fan is regulated, n1=cn, where: a, b, c are constants; A and B are the wading depth values ​​of the electronic fan.

2. The electronic fan wading control method according to claim 1, characterized in that: α is taken as 125%.

3. The electronic fan wading control method according to claim 1, characterized in that: A is 1 / 3R, B is 2 / 3R, and R is the radius of the wading electronic fan.

4. The electronic fan wading control method according to claim 1, characterized in that: a is 75%, b is 25%, and c is 0.

5. The electronic fan wading control method according to claim 1, characterized in that: A liquid level sensor is installed on the electronic fan. The water depth of the electronic fan is H=h1-h2, where h1 is the distance between the liquid level sensor and the wading liquid surface, and h2 is the distance between the liquid level sensor and the lower edge of the electronic fan blade.

6. The electronic fan wading control method according to claim 1, characterized in that: When there are x electronic fans on a single radiator, assuming that the speed of y electronic fans is reduced by a total of z% due to water wading protection, the speed of each electronic fan can be increased by z% / (xy) by increasing the speed of (xy) non-water wading electronic fans, compensating for the reduction in air volume and heat dissipation, thereby further ensuring that the vehicle cooling equipment operates within the preset high-performance range.

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