Anti-condensation structure and method for motor controller

Abstract

The present invention provides an anti-condensation structure and method for a motor controller, comprising a shell, an upper cover, and a double-breathing structure. The shell and the upper cover are detachably connected, and the double-breathing structure is installed on the side of the shell to change the path of heat convection of the shell. The present invention adopts a double-breathing valve structure, that is, a moisture-proof valve is added at a position with low condensation risk (low temperature rise area) to change the heat convection path, slow down the frequency of hot air concentrated in one place for gas exchange, and reduce the humidity inside the controller cavity; the present invention adopts a controller with a moisture-proof valve, and the gas pressure in the closed cavity changes due to temperature changes. The purpose of installing a breathing valve on the controller is to balance the gas pressure difference inside and outside the controller to prevent the shell from cracking. After the moisture-proof valve is applied, the influence of the external environmental humidity on the humidity of the air inside the controller will be greatly reduced, thereby achieving the purpose of moisture prevention and greatly reducing the risk of condensation.

Description

Technical Field

[0001] The present invention belongs to the technical field of controllers, and in particular relates to an anti-condensation structure and method for a motor controller. Background Art

[0002] Condensation in motor controllers for new energy vehicles usually occurs in two situations. One is when the external environment begins to heat up. Due to the difference in thermal inertia and specific heat capacity of materials, the heating and cooling rates of the controller housing surface and the surrounding air are different, making the temperature of the outer wall of the housing lower than the ambient temperature. The external hot water vapor will be cooled and liquefied on the outer wall of the housing to form condensation. Because the waterproof level of motor controllers for new energy vehicles meets the IPX7 requirements, this external condensation phenomenon will not affect the service life of the controller and there are usually no preventive measures. The other is when the motor controller has just stopped working. The temperature inside the controller housing is high. At this time, the cooling rate of the housing is large. The hot water vapor inside the controller will be cooled and liquefied on the inner wall of the housing to form condensation. Long-term internal condensation will cause corrosion of controller parts, short circuit of circuit boards, electrical insulation, creepage and other problems, which has a great impact on the service life of the controller. Therefore, designers need to try their best to avoid this internal condensation.

[0003] Absolute humidity refers to the weight of water per unit volume of air, generally measured in mg / L. Saturated humidity indicates the maximum amount of water vapor that can be contained in a unit volume of air at a given temperature. Relative humidity, on the other hand, is the ratio of absolute humidity to the maximum absolute humidity that a gas can reach at the same temperature, expressed as a percentage. Since the saturated humidity of air decreases with decreasing temperature, if the absolute humidity remains constant, once the temperature drops to a certain value, the air will reach the saturated humidity corresponding to that temperature. At this point, excess water vapor condenses and forms small droplets. This is the principle of condensation and the main reason for the so-called liquefaction of water vapor upon cooling.

[0004] Based on the above principles, motor controller designers can clearly calculate and verify the controller's condensation risk using known relative humidity, controller cavity volume, controller temperature conditions, and a table comparing saturated vapor pressure and water content at different temperatures. However, in practice, even with these pre-calibrated designs, motor controllers frequently experience design failures due to condensation. This is because the temperature rise of various modules in a motor controller varies significantly during operation, leading to significant temperature differences between different areas within the controller cavity. Consequently, the absolute humidity of the air within the cavity is not uniform (hygroscopic substances strive to maintain a balance between their own humidity and the surrounding humidity, known as relative humidity balance). Since the saturated humidity in high-temperature areas is higher than that in low-temperature areas, the absolute humidity in high-temperature areas is higher than that in low-temperature areas. Furthermore, motor controller casings are often equipped with a breather valve (also known as a vent valve) to balance the pressure difference between the inside and outside air caused by temperature fluctuations. This vent valve utilizes the order of magnitude difference in volume between gas and liquid to achieve a waterproof and breathable effect. However, since gas flows through the vent valve, the exchange of high-temperature gas in the cold casing is somewhat increased. Therefore, when we disassemble a motor controller that has failed due to condensation or perform a condensation test, we can find that condensation always occurs locally, usually near the high temperature rise module (the temperature rises during operation and the temperature difference is the largest when it stops working), the breathing valve installation area (where gas exchange is frequent), or the inner wall of the controller cavity in the upper half of the shell (because water vapor is lighter than air).

[0005] In addition to calculating and verifying condensation risks in advance, existing anti-condensation measures typically focus on dehumidification and insulation. For example: 1. Placing a desiccant inside the controller to reduce internal humidity and minimize condensation risk; 2. Adding a dehumidifier, using the same principle as in step 1; 3. Adding an insulation layer to the inner wall of the housing to reduce local temperature differences, such as by adding insulation pads or applying insulation paint.

[0006] Among the above-mentioned existing technical solutions, Solution 1 requires regular replacement of the desiccant, and the controller cover needs to be opened during replacement, which has poor maintainability and high risks; Solution 2 requires a larger installation space, a complex structure, and high costs; Solution 3 will increase the temperature rise inside the controller, requiring improved temperature resistance of internal parts materials or a larger structural space to help dissipate heat, but the structural space utilization rate is poor and the cost is high. Summary of the Invention

[0007] In view of the above problems, the present invention proposes an anti-condensation structure and method for a motor controller.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] An anti-condensation structure for a motor controller comprises a shell, an upper cover and a double breathing structure;

[0010] The shell and the upper cover are detachably connected;

[0011] The double-breathing structure is installed on the side of the shell to change the path of heat convection of the shell.

[0012] Preferably, the shell and the upper cover are connected by screws, and a flat sealant is applied between the joint surfaces of the shell and the upper cover. The shell is a rectangular shell structure, and the upper cover is a rectangular cover plate structure.

[0013] Preferably, the double-breathing structure includes a plurality of moisture-proof valves, which are installed in a low-temperature rise area of the shell, and the moisture-proof valves are detachably connected to the shell.

[0014] Preferably, the moisture-proof valve comprises a first spring, a second spring, a first valve, a second valve and a main body;

[0015] The main body is a T-shaped rotating body structure, with an opening at one end and a columnar inner cavity with a stepped structure at the other end;

[0016] The first spring, the second spring, the first valve and the second valve are all arranged in the inner cavity, and the elastic force of the first spring is greater than the elastic force of the second spring.

[0017] Preferably, the first spring is arranged inside the inner cavity;

[0018] The first valve is a rotating body structure with a cross-section, one end of which is fixedly connected to the first spring;

[0019] A fixing seat in a rotating body structure is installed in the inner cavity away from the opening, and a mounting cavity and an air hole communicating with the mounting cavity are defined in the fixing seat, and the second spring is installed in the mounting cavity;

[0020] The second valve is an annular structure, one end of which is fixedly connected to the second spring, and the other end of which is against the shoulder of the inner cavity step structure;

[0021] The first valve and the second valve are coaxially arranged, and one end of the first valve away from the first spring passes through the center of the second valve, and the first valve is positioned by the second valve.

[0022] Preferably, a breathable membrane and a breathable membrane protection cover are installed in the opening, and the breathable membrane protection cover is located outside the breathable membrane.

[0023] Preferably, a heat-spreading film is further included, which is adhered to the inner walls of the housing and the upper cover. The heat-spreading film is used to diffuse the heat of the local high-temperature area on the inner wall of the controller housing along the plane.

[0024] Preferably, the outer surface of the moisture-blocking valve is provided with threads, which are threadedly connected to the housing;

[0025] A sealing ring is provided on the flange surface of the moisture-proof valve close to the thread side.

[0026] A method for preventing condensation in a motor controller, which uses a double-breathing structure to conduct heat convection in a housing, comprises the following steps:

[0027] Preset intake and exhaust pressure values for the dual-breathing structure;

[0028] When the gas pressure inside the shell increases to a value greater than the exhaust pressure due to the increase in temperature, the double breathing structure performs positive pressure exhaust;

[0029] When the temperature inside the shell decreases and the gas pressure decreases to a value lower than the intake pressure, the double breathing structure performs negative pressure intake.

[0030] Preferably, the positive pressure exhaust comprises the following steps:

[0031] The high-pressure gas in the shell is exhausted to the outside through the moisture-proof structure until the pressure in the shell is lower than the exhaust pressure value;

[0032] The negative pressure air intake comprises the following steps:

[0033] When the air pressure in the shell is negative, the outside air flows into the shell through the moisture-proof structure until the air pressure in the shell is greater than the intake pressure value.

[0034] Beneficial effects of the present invention:

[0035] 1. Adopt a double breathing valve structure, that is, add a moisture-blocking valve at a location with low condensation risk (low temperature rise area), change the heat convection path, slow down the frequency of gas exchange when hot air is concentrated in one place, and reduce the humidity inside the controller cavity;

[0036] 2. Use a moisture-blocking valve. The gas pressure in the closed cavity changes with temperature. The purpose of installing a breather valve on the controller is to balance the gas pressure difference inside and outside the controller and prevent the shell from cracking. After the moisture-blocking valve is applied, the impact of external ambient humidity on the humidity of the air inside the controller will be greatly reduced, thereby achieving the purpose of moisture blocking and greatly reducing the risk of condensation. Since most of the electronic components inside the controller are electronic, the reduced humidity will obviously greatly improve the electrical insulation performance. Compared with traditional desiccant and dehumidification equipment, this method does not require regular replacement and maintenance, is easy to maintain, does not require additional installation space, has a compact structure, and is inexpensive.

[0037] 3. A heat-dissipating film is adhered to the inner wall of the controller housing to quickly spread the heat along the plane, thereby reducing the local temperature difference on the inner wall of the controller housing. This not only achieves the purpose of reducing local temperature differences and "heat dissipation", but also significantly improves the heat dissipation performance of the product. At the same time, its flexible film form can be well applied to the product surface. The film thickness can be as low as 12μm, which has almost no impact on the internal volume and quality of the product itself, and has a compact structure and high space utilization.

[0038] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0040] Figure 1 A schematic diagram of an anti-condensation structure of a motor controller of the present invention is shown;

[0041] Figure 2 The diagram shows the working principle of the positive pressure exhaust of the moisture-blocking valve of the present invention;

[0042] Figure 3 The diagram shows the working principle of the negative pressure air intake of the moisture-proof valve of the present invention.

[0043] In the figure: 1. Shell; 2. Upper cover; 3. Moisture-proof valve; 4. Heat-dissipating membrane; 5. First spring; 6. Second spring; 7. First valve; 8. Second valve; 9. Breathable membrane; 10. Main body; 1001. Inner cavity; 1002. Opening; 11. Fixed seat; 1101. Installation cavity; 1102. Air hole; 12. Breathable membrane protective cover; 13. Sealing ring. DETAILED DESCRIPTION

[0044] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0045] An anti-condensation structure for a motor controller, such as Figure 1 As shown, it includes a housing 1, an upper cover 2 and a moisture-proof structure;

[0046] The housing 1 and the upper cover 2 are detachably connected;

[0047] The double-breathing structure is installed on the side of the shell 1 to change the path of heat convection of the shell 1.

[0048] It should be noted that the high temperature rise area and the low temperature rise area of the housing 1 each have a breathing valve, and the heat convection path refers to the gas convection path in the high temperature rise area and the low temperature rise area.

[0049] Furthermore, the shell 1 and the upper cover 2 are connected by screws, and a flat sealant is applied between the joint surfaces of the shell 1 and the upper cover 2. The shell 1 is a rectangular shell structure, and the upper cover 2 is a rectangular cover plate structure.

[0050] It should be noted that other places on the housing 1 that need to be sealed will use sealing structures to form a closed cavity. In addition, the housing 1 is of various types and is generally a rectangular structure with various electronic components installed inside. The upper cover 2 is adaptively matched with the housing 1.

[0051] Furthermore, the double-breathing structure includes a plurality of moisture-proof valves 3 , which are installed in the low-temperature rise area of the housing 1 , and the moisture-proof valves 3 are detachably connected to the housing 1 .

[0052] It should be noted that the double breathing structure changes the heat convection and generally adopts two moisture-proof valves 3 to reduce the ventilation frequency of hot air concentrated in the local area. Obviously, more than two moisture-proof valves 3 or other breathing valves can also be used to change the convection mode of the air inside the controller to achieve the same effect.

[0053] It should be noted that in actual application, the moisture-proof structure generally adopts a moisture-proof valve 3, or a structure with similar function to the moisture-proof valve 3. The installation method can be a snap connection or a threaded connection. The structure adopts a double breathing valve structure, and a moisture-proof valve 3 is installed at two positions shown in the figure.

[0054] It should be further explained that a double breathing valve structure is formed by adopting two moisture-proof valves 3: The heat transfer process of an object is divided into three basic heat transfer modes, namely heat transfer, heat convection and heat radiation. Under low temperature conditions (below 2000K), the influence of thermal radiation of the air is very small and is generally not considered in engineering calculations. In addition, the thermal conductivity of air is very low and can usually be ignored. Therefore, changing the thermal convection of the air inside the controller is the most direct and effective way to affect the heat transfer of the air. Based on this idea, the present invention proposes a double breathing valve arrangement structure to reduce the ventilation frequency of hot air concentrated in one place of the shell 1, which can effectively suppress the occurrence of condensation. It should be noted that the breathing valve proposed in this patent must be arranged in the low-temperature rise area of the shell 1, and is usually arranged on the side of the shell 1. This is because: the energy of the hot air flow is high, the distance between gas molecules is large, and the gas with low density is light, so the hot air will rise. If it is arranged above the shell 1, it will intensify the local convection heat transfer of the hot air, thereby increasing the probability of condensation; if it is arranged below the shell 1, the dust and powder raised when the car is driving will act on the breathing valve, and if it is under long-term working conditions, it will cause blockage, corrosion and other failure risks.

[0055] Furthermore, the moisture-proof valve 3 includes a first spring 5, a second spring 6, a first valve 7, a second valve 8 and a main body 10;

[0056] The main body 10 is a T-shaped rotating body structure, with an opening 1002 at one end and a cylindrical inner cavity 1001 with a stepped structure at the other end;

[0057] The first spring 5 , the second spring 6 , the first valve 7 and the second valve 8 are all arranged in the inner cavity 1001 , and the elastic force of the first spring 5 is greater than the elastic force of the second spring 6 .

[0058] Furthermore, the first spring 5 is arranged inside the inner cavity 1001;

[0059] The first valve 7 is a rotating body structure with a cross-section, one end of which is fixedly connected to the first spring 5;

[0060] A fixing base 11 of a rotating body structure is installed in the inner cavity 1001 away from the opening 1002. The fixing base 11 has an installation cavity 1101 and an air hole 1102 communicating with the installation cavity 1101. The second spring 6 is installed in the installation cavity 1101.

[0061] The second valve 8 is an annular structure, one end of which is fixedly connected to the second spring 6, and the other end of which is against the shoulder of the step structure of the inner cavity 1001;

[0062] The first valve 7 and the second valve 8 are coaxially arranged, and one end of the first valve 7 away from the first spring 5 passes through the center of the second valve 8 , so that the first valve 7 is positioned by the second valve 8 .

[0063] It should be noted that when the temperature rises, the gas will be discharged; when the temperature drops, the gas will be inhaled. This is the "breathing effect". The general breathing valve only uses the order of magnitude difference between the volume of liquid and gas to set a layer of microporous breathable membrane 9 to achieve a waterproof effect, but the air can still circulate freely, so the relative humidity of the air inside the controller will be balanced with the external environment. If we can preset the pressure value required for the breathing valve inlet and exhaust valves to open, we can achieve an effect of "easy to exhaust and difficult to intake", which can obviously effectively prevent the entry of external humid air. The present invention is based on this idea and applies the moisture-proof valve 3 described in this article. Usually, controllers are assembled in a dust-free workshop with constant temperature and humidity. The relative humidity of the air inside the controller can be effectively guaranteed. After applying the moisture-proof valve 3, the influence of the external environmental humidity on the humidity of the air inside the controller will be greatly reduced, thereby achieving the purpose of moisture prevention and greatly reducing the risk of condensation. In addition, there are mostly electronic components inside the controller, and the reduction in humidity will obviously also greatly improve the electrical insulation performance. Compared with traditional desiccant and dehumidification equipment, this method does not require regular replacement and maintenance, has good maintainability, does not require additional installation space, has a compact structure, and is inexpensive.

[0064] Furthermore, a breathable membrane 9 and a breathable membrane protection cover 12 are installed in the opening 1002 , and the breathable membrane protection cover 12 is located outside the breathable membrane 9 .

[0065] It should be noted that the function of the breathable membrane 9 is to utilize the volume order of magnitude difference between gas molecules and liquid and dust particles to allow gas molecules to pass through while liquid and dust cannot pass through, thereby achieving the waterproof and breathable function.

[0066] Furthermore, a heat-spreading film 4 is included. The heat-spreading film 4 is attached to the inner walls of the housing 1 and the upper cover 2 . The heat-spreading film 4 is used to diffuse the heat of the local high-temperature area on the inner wall of the controller housing 1 along the plane.

[0067] It should be noted that the heat spreader film 4 is a brand-new thermally conductive and heat-dissipating material with a unique nano-carbon atom orientation structure. It has excellent thermal conductivity in both horizontal and vertical directions (the thermal conductivity coefficient can reach up to 1900W / m·K, which is 4 to 5 times that of copper, while the density is only 1 / 4 of copper). It can quickly diffuse heat from the local high-temperature area on the inner wall of the controller housing along the plane, not only achieving the purpose of reducing local temperature differences and "heat equalization", but also significantly improving the product's heat dissipation performance. At the same time, its flexible film form is well suited for application on product surfaces. The film thickness can be as low as 12μm, with almost no impact on the internal volume and mass of the product itself, and the structure is compact and space utilization is high.

[0068] It should be further explained that the materials and processes for equalizing heat can obviously be replaced by other materials and processes that can achieve the same effect: such as applying equalizing heat paint, equalizing heat silicone grease, glue, etc.

[0069] Furthermore, the outer surface of the moisture-proof valve 3 is provided with threads and is threadedly connected to the housing 1 .

[0070] A sealing ring 13 is provided on the flange surface of the moisture-proof valve 3 close to the thread side.

[0071] It should be noted that the sealing ring 13 is used to improve the sealing between the housing 1 and the moisture-blocking valve 3 .

[0072] A method for preventing condensation of a motor controller, wherein heat convection of a housing 1 is performed through a double-breathing structure, comprises the following steps:

[0073] Preset intake and exhaust pressure values of the moisture-proof structure;

[0074] When the gas pressure inside the shell 1 increases to a value greater than the exhaust pressure due to the increase in temperature, the double breathing structure performs positive pressure exhaust;

[0075] When the temperature inside the shell 1 drops and the gas pressure decreases to a value lower than the intake pressure, the double breathing structure performs negative pressure intake.

[0076] It should be noted that the region in the housing 1 where the temperature rises is generally a region where condensation is likely to occur (high temperature rise region).

[0077] Furthermore, the positive pressure exhaust comprises the following steps:

[0078] The high-pressure gas in the shell 1 is exhausted to the outside through the double-breathing structure until the pressure in the shell 1 is lower than the exhaust pressure value;

[0079] Negative pressure air intake includes the following steps:

[0080] When the air pressure in the shell 1 is negative, the outside air is drawn into the shell 1 through the double-breathing structure until the air pressure in the shell 1 is greater than the intake pressure value.

[0081] It should be noted that if Figure 2 As shown, when the gas pressure inside the controller increases due to rising temperature, the moisture-proof valve 3 is in a positive pressure exhaust state, that is, the internal air overcomes the elastic force of the second spring 6, pushes the first valve 7 open, and the air passes through the gap between the first valve 7 and the second valve 8, and then is discharged from the controller cavity through the breathable membrane 9.

[0082] like Figure 3As shown, when the controller's internal temperature drops and the gas pressure decreases, moisture-blocking valve 3 enters a negative-pressure intake state. This means that outside air must overcome the elastic force of first spring 5 to push open second valve 8. At this point, due to the elastic force of second spring 6, first valve 7 remains firmly against second valve 8. After passing through breathable membrane 9, outside air passes through the gap between second valve 8 and main body 10. Given the spring force F = -kx, where k is the spring constant and x is the amount of spring compression, this structure can increase the pressure required for the negative-pressure intake state without increasing the pressure required for the positive-pressure exhaust state by adjusting the spring constants and compression of first and second springs 5 and 6. Specifically, moisture-blocking valve 3 enters the intake state only when the external air pressure exceeds the internal air pressure by a certain value. It remains in the exhaust state at all other times, thereby preventing external moisture from entering and reducing the humidity within the cavity.

[0083] It should be noted that the purpose of using the anti-humidity valve 3 in the present invention is mainly to enable the designer to preset the pressure values required for opening the inlet and exhaust valves. The anti-humidity valve 3 exemplified in this article uses the principle of spring structure to achieve this function. Obviously, a breathing valve that achieves the same function through other structural forms can also replace the "anti-humidity valve 3" described in this article.

[0084] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An anti-condensation structure for a motor controller, characterized in that: It comprises a shell (1), an upper cover (2), a double breathing structure and a heat-dissipating film (4); The anti-condensation structure is installed in the motor controller of the automobile; The shell (1) and the upper cover (2) are detachably connected; the shell (1) and the upper cover (2) are connected by screws, and a flat sealant is applied between the joint surfaces of the shell (1) and the upper cover (2); the shell (1) is a rectangular shell structure, and the upper cover (2) is a rectangular cover plate structure; The double breathing structure is installed on the side of the shell (1) and is used to change the path of heat convection of the shell (1); The double-breathing structure comprises two moisture-blocking valves (3), the moisture-blocking valves (3) being installed in a low-temperature rise region of the housing (1) and located on two adjacent sides of the housing (1), and the moisture-blocking valves (3) being detachably connected to the housing (1); The heat-dissipating film (4) is attached to the inner walls of the housing (1) and the upper cover (2). The heat-dissipating film (4) is used to diffuse the heat of the local high-temperature area of the inner wall of the controller housing (1) along the plane, thereby reducing the local temperature difference. The heat-dissipating film (4) has a thermal conductivity of 4 to 5 times that of copper and a density of 1 / 4 that of copper. The energy of the thermal airflow at the top of the shell (1) is higher than the energy of the thermal airflow at the side of the shell (1); The moisture-proof valve (3) comprises a first spring (5), a second spring (6), a first valve (7), a second valve (8) and a main body (10); The main body (10) is a T-shaped rotating body structure, with an opening (1002) provided at one end and a columnar inner cavity (1001) with a stepped structure provided at the other end; The first spring (5), the second spring (6), the first valve (7) and the second valve (8) are all arranged in the inner cavity (1001), and the elastic force of the first spring (5) is greater than the elastic force of the second spring (6); The first spring (5) is arranged inside the inner cavity (1001); The first valve (7) is a rotating body structure with a cross-section, one end of which is fixedly connected to the first spring (5); A fixing seat (11) having a rotating body structure is installed in the inner cavity (1001) away from the opening (1002), and a mounting cavity (1101) and an air hole (1102) communicating with the mounting cavity (1101) are provided in the fixing seat (111), and the second spring (6) is installed in the mounting cavity (1101); The second valve (8) is an annular structure, one end of which is fixedly connected to the second spring (6), and the other end of which is against the shoulder of the step structure of the inner cavity (1001); The first valve (7) and the second valve (8) are coaxially arranged, and the end of the first valve (7) away from the first spring (5) passes through the center of the second valve (8), and the first valve (7) is positioned by the second valve (8).

2. The anti-condensation structure of a motor controller according to claim 1, characterized in that: A breathable membrane (9) and a breathable membrane protection cover (12) are installed in the opening (1002), and the breathable membrane protection cover (12) is located outside the breathable membrane (9).

3. The anti-condensation structure of a motor controller according to claim 1 or 2, characterized in that: The outer surface of the moisture-blocking valve (3) is provided with threads, and is threadedly connected to the housing (1); A sealing ring (13) is provided on the flange surface of the moisture-blocking valve (3) close to the threaded side.

4. A method for preventing condensation of a motor controller, characterized in that: The anti-condensation structure for the motor controller according to any one of claims 1 to 3 comprises the following steps: Preset intake and exhaust pressure values for the dual-breathing structure; When the gas pressure inside the shell (1) increases to a value greater than the exhaust pressure due to temperature rise, the double breathing structure performs positive pressure exhaust; When the temperature inside the shell (1) decreases and the gas pressure decreases to a value less than the intake pressure, the double breathing structure performs negative pressure intake.

5. The anti-condensation method for a motor controller according to claim 4, characterized in that: The positive pressure exhaust comprises the following steps: The high-pressure gas in the shell (1) is exhausted to the outside through the moisture-proof structure until the gas pressure in the shell (1) is lower than the exhaust pressure value; The negative pressure air intake comprises the following steps: When the air pressure in the shell (1) is negative, external air is drawn into the shell (1) through the moisture-blocking structure until the air pressure in the shell (1) is greater than the intake pressure value.

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