A motor controller internal condensation removal device and method

Abstract

This invention belongs to the field of motor controller technology, specifically a device and method for removing condensation inside a motor controller. It includes: a water droplet detection sensor for directly detecting the presence of liquid condensation droplets inside the motor controller; a low-pressure heating device for directional heating of areas prone to condensation; and a control unit for controlling the operation of the low-pressure heating device based on the detection signal from the water droplet detection sensor. This invention uses a water droplet detection sensor directly attached to the condensation-prone location, which can directly identify liquid water droplets rather than indirectly detecting air humidity. It triggers an early warning as soon as condensation droplets form, completely solving the problems of existing technologies lacking condensation detection and intervention and being disconnected from actual conditions. This achieves early, accurate, and targeted identification of condensation, providing the best opportunity for condensation removal and accurate feedback for closed-loop control.

Description

Technical Field

[0001] This invention relates to the field of motor controller technology, specifically to a device and method for removing condensation inside a motor controller. Background Technology

[0002] With the rapid development of the new energy vehicle industry, the drive motor controller, as one of the three core components of the new energy vehicle power system, directly determines the driving safety and performance of the entire vehicle through its operational reliability. The drive motor controller integrates high-voltage components such as IGBT power modules, film capacitors, and high-voltage copper busbars, with operating voltages generally exceeding 300V. This places extremely high demands on the insulation performance and dryness of the internal components.

[0003] Throughout the vehicle's entire lifecycle, the drive motor controller frequently undergoes temperature cycles of "heating up during operation and cooling down during shutdown," while also needing to adapt to a wide ambient temperature range of -40℃ to 85℃. The controller cavity is connected to the external environment through a pressure balancing valve to balance the air pressure inside and outside the cavity. During temperature cycles, humid air from the outside enters the cavity through the pressure balancing valve. Since the heat-generating components such as the IGBTs are concentrated inside the controller, the temperature distribution within the cavity is extremely uneven. Areas far from the heat-generating components, such as the edges of the housing and thin-walled covers, have temperatures far lower than the average cavity temperature. When humid air flows through these low-temperature areas, if the surface temperature is below the air dew point, moisture will condense on the inner wall of the housing / cover, forming condensation droplets.

[0004] In existing technologies, the vent membrane of the pressure balance valve can only allow gaseous water vapor to enter and exit, but cannot discharge liquid water droplets. As a result, condensation water droplets accumulate continuously during the long-term operation of the controller. When the water droplets accumulate to a certain amount, they will be dispersed to high-voltage exposed components such as high-voltage copper busbars and power device pins due to vehicle vibration. This will directly cause a sudden drop in insulation resistance, triggering a vehicle insulation fault, resulting in vehicle power interruption and inability to operate normally. In severe cases, it may even cause safety accidents such as high-voltage short circuits and fires.

[0005] Currently, the industry has conducted numerous studies on the condensation problem of motor controllers. Existing solutions are mostly focused on passive prevention, reducing condensation by guiding the condensation location, optimizing airflow paths, and providing thermal insulation. However, these methods cannot fundamentally solve the problem of removing condensation that has already formed. Furthermore, they suffer from defects such as detection lag, poor adaptability to operating conditions, and insufficient long-term reliability. Insulation failures caused by condensation remain a common pain point in the new energy vehicle industry.

[0006] Existing technology includes patent CN212013222U, which discloses an anti-condensation structure and power electronic equipment. This patent represents a mainstream application solution in the field of anti-condensation for motor controllers in new energy vehicles, and its core technical solution is as follows: Core structure: The anti-condensation structure includes a main shell, a condensation component, and a storage component. The main shell is equipped with a waterproof and breathable valve and a closed mounting cavity. The mounting cavity is connected to the outside through the waterproof and breathable valve. The condensation component and the storage component are both located in the mounting cavity. The condensation component is located above the storage component. A natural convection circulation air duct driven by temperature difference is formed in the mounting cavity. The core part of the condensation component is arranged on the circulation air duct.

[0007] Anti-condensation principle: By utilizing the difference in cooling rate between the casing and the core heating area during the operation and shutdown of the controller, a natural convection microcirculation is formed in the cavity. This guides the gaseous water molecules in the convective gas in the circulating air duct to condense into liquid water on the surface of the condensation component. The liquid water is then collected by the collection component below, thereby controlling the condensation location of water vapor and preventing condensate from contacting high-voltage electronic devices and electrical circuits.

[0008] Optimization solution: Install an insulation layer at the preset location on the inner wall of the installation cavity where condensation is likely to occur to reduce the cooling rate at the corresponding location and reduce water vapor condensation at that location; The condensation component adopts a heat-conducting metal component, with one end extending to the outside of the shell to achieve rapid cooling and enhance the condensation effect; The storage component has a built-in water-absorbing component to stably absorb condensate and prevent liquid water from splashing out.

[0009] Extended solution: A guide fan can be added inside the cavity to force the airflow in the circulating air duct to flow through the condensation components, thereby improving the condensation and anti-condensation effects.

[0010] Based on the above, the existing technology has the following specific problems: 1. It is impossible to actively and completely eliminate condensation; the risk of condensation can only be passively transferred. Existing technologies employ guided condensation and centralized collection solutions, which can only control the location of condensation formation but cannot remove the formed liquid condensation from the controller cavity. The liquid water remains inside the cavity. When the collection component becomes saturated with water or when the vehicle vibrates, the liquid water can easily diffuse to the high-voltage exposed components, causing malfunctions such as decreased insulation resistance and high-voltage short circuits. It is impossible to fundamentally eliminate the safety hazards caused by condensation.

[0011] 2. The lack of a direct detection mechanism for liquid condensation prevents the formation of effective closed-loop control. Existing solutions lack real-time detection components for liquid condensation, making it impossible to accurately identify the generation and development of condensation within the cavity. They also fail to trigger targeted interventions based on actual condensation conditions, resulting in a complete disconnect between intervention actions and the actual condensation state. This approach relies solely on indiscriminate, passive design to address condensation risks, failing to adapt to changes in condensation under different environments and operating conditions.

[0012] 3. The anti-condensation function relies on the high-voltage operating state of the controller, which limits its adaptability to various operating conditions. The existing solution's anti-condensation effect depends on the temperature difference and airflow circulation generated by the controller's heat generation during operation. When the vehicle is in a low-temperature, stationary state and the controller is off, there is no stable temperature difference or convection circulation within the cavity, and the anti-condensation function cannot be implemented normally. It cannot cover the operating conditions where condensation is common when the vehicle is powered on after being stationary at low temperatures.

[0013] 4. Insufficient long-term operational reliability, failing to meet the maintenance-free usage requirements throughout the vehicle's entire lifecycle. Existing solutions rely on consumable components such as water-absorbing parts, which lose their water-absorbing capacity once saturated, requiring periodic disassembly and replacement of the controller. This not only incurs high maintenance costs but also compromises the controller's protection rating. Furthermore, the insulation layers and functional coatings used in these solutions are prone to aging and peeling, and their anti-condensation performance continuously declines over time, failing to meet the long-life, high-reliability requirements of automotive products.

[0014] 5. The core conditions for condensation cannot be eliminated at their source, resulting in limited effectiveness in preventing condensation. Existing solutions can only slow down the cooling rate of the shell through the insulation layer, but cannot solve the problem of uneven temperature distribution within the controller cavity, eliminate localized low-temperature zones, or disrupt the core temperature conditions for water vapor condensation, thus still posing a risk of continuous condensation. Summary of the Invention

[0015] To solve the above-mentioned technical problems, the present invention provides the following technical solution: A device for removing condensation inside a motor controller includes a drive motor controller housing and a controller cover plate disposed on the drive motor controller housing. The drive motor controller housing contains a high-voltage copper busbar assembly, a pressure balance valve, an IGBT power module, and a thin-film capacitor. The device also includes: A water droplet detection sensor is used to directly detect whether liquid condensation water droplets exist inside the motor controller; Low-pressure heating device for directional heating of areas prone to condensation; The control unit is used to control the low-pressure heating device to work according to the detection signal of the water droplet detection sensor. The signal output terminal of the water droplet detection sensor is connected to the signal input terminal of the control unit, and the control output terminal of the control unit is connected to the power supply circuit of the low-pressure heating device.

[0016] As a preferred embodiment of the condensation removal device inside the motor controller described in this invention, the water droplet detection sensor is attached to the condensation-prone area of ​​the inner wall of the drive motor controller housing and the controller cover, and is arranged adjacent to or stacked with the low-pressure heating device.

[0017] In a preferred embodiment of the condensation removal device inside the motor controller described in this invention, when the water droplet detection sensor and the low-pressure heating device are arranged adjacent to each other, both the low-pressure heating device and the water droplet detection sensor are attached to the condensation-prone areas of the inner wall of the drive motor controller housing and the controller cover plate through an adhesive layer, and an insulating and heat-conducting layer is provided between the adhesive layer and the drive motor controller housing and the controller cover plate.

[0018] As a preferred embodiment of the condensation removal device inside the motor controller described in this invention, when the water droplet detection sensor and the low-pressure heating device are stacked and combined, the adhesive layer, the low-pressure heating device, the insulating heat-conducting layer and the water droplet detection sensor are arranged sequentially from the inner wall of the drive motor controller housing and the controller cover plate outward, so that the sensing surface of the water droplet detection sensor faces the inside of the cavity.

[0019] As a preferred embodiment of the condensation removal device inside the motor controller described in this invention, the power supply circuit of the low-pressure heating device is provided with a controllable switch, and the control unit controls the low-pressure heating device by controlling the on / off state of the controllable switch.

[0020] As a preferred embodiment of the condensation removal device inside the motor controller described in this invention, the power supply terminal of the low-voltage heating device is connected to the low-voltage electrical input interface and the control board voltage output port located in the housing of the drive motor controller.

[0021] As a preferred embodiment of the condensation removal device inside the motor controller described in this invention, the control unit is a motor controller MCU or a vehicle VCU, so that monitoring and control can be started when the vehicle is powered on at low voltage.

[0022] A method for removing condensation inside a motor controller includes the following steps: S1, the control unit collects the detection signal from the water droplet detection sensor in real time; S2, When the water droplet detection sensor detects condensation, the control unit connects the power supply circuit of the low-voltage heating device to heat it up and raise the temperature of the condensation area; S3, when the low-pressure heating device is heating, the power-off timing is controlled by either an open-loop fixed duration mode or a closed-loop detection mode. S4, after heating is complete, return to S1 for continuous monitoring.

[0023] As a preferred embodiment of the method for removing condensation inside a motor controller according to the present invention, the open-loop fixed duration mode is as follows: the optimal heating duration is determined in advance through experiments, and the power supply is turned on and the heating continues until the preset duration is reached before the power is automatically turned off. The closed-loop detection mode is as follows: continuously collect signals from the water droplet detection sensor until no condensation is detected, then immediately disconnect the power supply.

[0024] As a preferred embodiment of the method for removing condensation inside a motor controller according to the present invention, in the process of heating by the low-voltage heating device, an overtime protection, overheat protection and short-circuit protection mechanism are added. If condensation is still detected after a single heating exceeds the preset maximum duration and maximum temperature, the power supply is automatically disconnected and the fault is reported to the whole vehicle.

[0025] Compared with existing technologies: 1. By setting water droplet detection sensors that can directly detect liquid condensation in the condensation-prone areas of the motor controller, early, accurate, and targeted identification of condensation can be achieved, providing accurate feedback for condensation intervention and constructing a closed-loop control system for condensation prevention and control. 2. By using a low-pressure heating device matched with a water droplet detection sensor to directionally heat areas prone to condensation, the condensed water droplets are rapidly heated and evaporated into gaseous water vapor, which is then discharged from the controller cavity through a pressure balance valve, completely removing liquid condensation from the cavity and fundamentally solving the risk of insulation failure caused by condensation accumulation. 3. By using a low-pressure heating device to directionally raise the temperature of local low-temperature areas prone to condensation, it can eliminate local low-temperature areas in the controller cavity, reduce the temperature difference in the cavity, and destroy the core temperature conditions for water vapor condensation, thus preventing the generation of new condensation from the root. 4. By connecting the power supply terminal of the low-voltage heating device to the low-voltage power supply of the vehicle or the low-voltage output port of the motor controller board, and in conjunction with the control unit that can start working when the vehicle is powered on at low voltage, it can realize the condensation monitoring and removal work without relying on the high-voltage working state of the controller, and can operate normally under all vehicle working conditions, thus fully covering the high-concentration scenarios. 5. By using a solid-state long-life water droplet detection sensor and a low-pressure heating device to construct a condensation removal device, the device has the effect of having no consumable parts, no need for regular disassembly, maintenance and replacement of parts, stable long-term operation performance without degradation, and meeting the requirements of the whole vehicle's entire life cycle. 6. The control unit controls the start and stop of the low-voltage heating device based on the detection signal from the water droplet detection sensor. With multiple safety protection mechanisms, it can achieve intelligent and precise control of condensation prevention and control, while ensuring the electrical safety of the device and the stable operation of the vehicle's low-voltage electrical system. 7. By adopting a flexible and adaptable patch-type structure design for the water droplet detection sensor and low-pressure heating device, it is possible to directly adapt to different models of motor controllers without making significant changes to the existing motor controller's housing structure, main circuit design, and heat dissipation system, thereby reducing product modification costs and facilitating mass production and promotion. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the installation layout of the condensation removal device of the present invention inside the drive motor controller. Figure 2 This is a front view of the installation cross-section of the water droplet detection sensor of the present invention; Figure 3 This is a side view of the installation cross-section of the water droplet detection sensor of the present invention; Figure 4 This is a logic flowchart of the condensation removal control method of the present invention; Figure 5 This is a schematic diagram of a multi-point distributed installation embodiment of the present invention.

[0027] In the diagram: 1. Drive motor controller housing; 2. Controller cover; 3. Low-voltage heating device; 4. Water droplet detection sensor; 5. Motor controller MCU; 6. Low-voltage electrical input interface; 7. Control board voltage output port; 8. High-voltage copper busbar assembly; 9. Air pressure balance valve; 10. IGBT power module; 11. Thin film capacitor; 12. Insulating and thermally conductive layer; 14. Adhesive layer; 15. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0029] This invention provides a device for removing condensation inside a motor controller. Please refer to [link / reference]. Figures 1-5 The system includes a drive motor controller housing 1 and a controller cover 2 mounted on the drive motor controller housing 1. The drive motor controller housing 1 contains a high-voltage copper busbar assembly 9, a pressure balance valve 10, an IGBT power module 11, and a film capacitor 12. Each core high-voltage component is fixedly assembled in a pre-set installation position inside the drive motor controller housing 1 according to the mass production standard of new energy vehicle motor controllers. The high-voltage copper busbar assembly 9 is isolated and insulated from the drive motor controller housing 1 by insulating fixing posts. The IGBT power module 11 and the film capacitor 12 are installed by bolts to be fastened to the heat dissipation surface of the drive motor controller housing 1. The pressure balance valve 10 is sealed and embedded in the reserved installation hole on the side wall of the drive motor controller housing 1. The system ensures the IP67 protection level of the controller cavity and the high-voltage insulation safety performance throughout the process, providing a stable working condition for condensation prevention.

[0030] It also includes: a low-pressure heating device 3, used for directional heating of areas prone to condensation; specifically: the low-pressure heating device 3 is a low-pressure 12V~48V heating device, preferably using a flexible heating patch (the shape of the heating patch can be customized and cut according to the shape of the condensation-prone location), specifically, any one of graphene heating patches, ceramic heating patches, and PTC flexible heating sheets can be selected, this embodiment preferably uses a graphene flexible heating patch, which has the core advantages of being flexible and easy to cut, having uniform heat conduction, fast heating rate, resistance to high and low temperature aging, and low electromagnetic interference, adapting to the narrow and irregular installation space inside the controller, and having no risk of warping or falling off after installation, adapting to the harsh operating conditions of vibration and high and low temperature cycles throughout the vehicle's entire life cycle. The electrical parameters of the low-voltage heating device 3 strictly match the specifications of the vehicle's low-voltage electrical system. The rated operating voltage covers 12V~48V, which is compatible with the conventional low-voltage power supply system of pure electric and hybrid vehicles. The rated power is precisely controlled between 5W and 20W, which can be flexibly adjusted according to the size of the heating area and the area prone to condensation. The heating surface is stably and constantly controlled between 40℃ and 60℃. This temperature range can ensure that the condensation droplets are quickly heated and evaporated without causing additional heat load and high-temperature damage to the surrounding IGBT power module 11, film capacitor 12 and other precision electronic components. At the same time, it fully meets the design requirements of the vehicle's low-voltage electrical safety isolation, short circuit prevention and leakage prevention. The power supply scheme offers two compatible and seamlessly switchable power supply methods, allowing for flexible selection based on different vehicle controller configurations, upgrades of older models, or design requirements of new mass-produced vehicles: Method 1: The power supply is connected to the reserved wiring harness terminal of the low-voltage input interface 7 of the motor controller. The power supply voltage is the vehicle's standard 12V / 24V low-voltage power supply. The power supply circuit is connected in series with an automotive-grade low-voltage fuse and a controllable switch. The power supply is independent and not limited by the controller's high-voltage power-on or shutdown status. It can still operate normally under low-temperature static conditions. Method 2: The power supply is connected to the control board voltage output port 8 on the drive motor controller's control board. The power supply voltage is 12V~48V, the control board's output voltage. The control board directly provides basic power supply and basic overcurrent and overvoltage protection, eliminating the need for additional external protection devices and simplifying the assembly and wiring process. In terms of control interface, an automotive-grade controllable switch is set on the power supply circuit, preferably a MOSFET or a small automotive-grade relay. The control terminal of the controllable switch is precisely connected to the control I / O port of the control unit (MCU5 / VCU). The control unit outputs high and low level signals to realize the precise on / off control of the controllable switch and the start / stop control of heating. The response action is triggered in milliseconds, with high control accuracy and no delay or stuttering.Based on the above structural design, the low-pressure heating device 3 also includes several alternative solutions adapted to different mass production scenarios. Structurally, it can be replaced with hard ceramic heating elements or PTC heating blocks, and can be used with standard controller products that have flat inner walls and sufficient installation space, such as drive motor controller housing 1, and can be fixed and installed by snap-fit ​​and bolt fastening. For irregularly shaped curved drive motor controller housing 1 structures, irregularly shaped injection-molded flexible heating wire components can be used with 3D-printed mounting brackets to ensure a tight fit between the heating surface and areas prone to condensation. The power supply, power control, and heating method can all be adapted and adjusted according to the actual vehicle model requirements, taking into account both mass production matching for new models and after-sales modification and upgrade needs for older models, making it highly versatile. Among them, the heating method can be replaced with an infrared heating film, which can achieve non-contact directional heating for irregularly shaped structures and narrow gaps where patches cannot be attached, avoiding the adaptation difficulties of patch installation; it can also be replaced with a carbon fiber heating wire braided structure, which can be adapted to irregularly shaped areas prone to condensation, achieving uniform heating.

[0031] The water droplet detection sensor 4 is used to directly detect whether liquid condensation droplets exist inside the motor controller. Specifically, the water droplet detection sensor 4 preferably adopts a labyrinth-shaped interdigital electrode flexible thin-film water droplet sensor, but capacitive or resistive water droplet detection patches can also be used. In this embodiment, the labyrinth-shaped interdigital electrode flexible thin-film sensor is preferred. The spacing between the labyrinth-shaped interdigital electrodes is precisely controlled between 0.2mm and 0.5mm. The electrode surface is treated with an insulating, moisture-proof, and wear-resistant coating. When water vapor in the cavity condenses to form liquid water droplets that cover the electrode surface, the resistance and capacitance parameters between the electrodes undergo instantaneous changes. It can simultaneously output a switch signal indicating whether condensation has occurred and an analog signal indicating the degree of condensation. The detection response time is ≤1s, which can quickly and accurately identify the initial formation of a small amount of condensation droplets. The smallest detectable water droplet diameter is as low as 0.5mm. The detection sensitivity and accuracy are fully adapted to the controller's early warning requirements for condensation. The water droplet detection sensor 4 is precisely attached to the high-concentration areas on the inner walls of the drive motor controller housing 1 and the controller cover 2. It prioritizes full coverage of the low-temperature areas on the housing corners, thin-walled cover plates, and cavity edges, away from core heat-generating components such as the IGBT power module 11 and thin-film capacitor 12. It accurately focuses on the core points with the lowest temperature and the most prone to condensation, achieving dedicated monitoring of condensation without blind spots. The sensor and the low-voltage heating device 3 can be installed in two compatible modes: adjacent arrangement or stacked composite arrangement. The sensor can be flexibly selected and adapted according to the size of the installation space and structural layout inside the controller cavity. Both installation modes are fixed by a special high-temperature resistant insulating adhesive process to ensure that the installation is firm and will not fall off under long-term vibration conditions. Method 1: When the water droplet detection sensor 4 and the low-pressure heating device 3 are arranged adjacent to each other, the distance between them is controlled within a reasonable range of 10mm to 20mm. This ensures that they do not interfere with each other's operation and that the heating heat can quickly cover the sensor monitoring area. Both the low-pressure heating device 3 and the water droplet detection sensor 4 are tightly attached to the inner wall of the drive motor controller housing 1 and the controller cover plate 2, which are prone to condensation, through the adhesive layer 15. The adhesive layer 15 is made of automotive-grade high-temperature resistant and waterproof silicone adhesive material, and the adhesive thickness is uniformly controlled within 0.3mm to 0.5mm, taking into account the bonding fixation, insulation sealing and heat conduction performance. An insulating and heat-conducting layer 14 is added between the adhesive layer 15 and the drive motor controller housing 1 and the controller cover plate 2. The insulating and heat-conducting layer 14 is made of high thermal conductivity insulating silicone sheet material, which not only isolates the electromagnetic interference of the metal material of the housing to the sensor detection signal, but also can quickly conduct the heating heat, ensuring detection accuracy and heating conduction efficiency.Method 2: When the water droplet detection sensor 4 and the low-pressure heating device 3 are stacked and composited, the adhesive layer 15, the low-pressure heating device 3, the insulating and heat-conducting layer 14, and the water droplet detection sensor 4 are sequentially and orderly stacked from the inner wall of the drive motor controller housing 1 and the controller cover plate 2 outwards. They are strictly adhered to the layer order and pressed firmly to ensure that the sensing surface of the water droplet detection sensor 4 faces the inside of the controller cavity, guaranteeing that condensed water droplets inside the cavity can directly fall onto the sensor's sensing surface, achieving efficient and accurate condensation detection. Simultaneously, the insulating and heat-conducting layer 14 effectively isolates the electromagnetic signals generated by the low-pressure heating device 3 during operation, preventing interference from heating conditions on the sensor's detection accuracy. This achieves integrated arrangement of detection and heating, saving installation space inside the cavity. Regarding the signal interface, the signal output terminal of the water droplet detection sensor 4 is stably connected to the AD acquisition port or IO port of the control unit via a shielded wire harness. The shielded wire harness effectively avoids electromagnetic interference generated by the high-voltage copper busbar and power module inside the controller, ensuring stable, distortion-free, and false alarm-free transmission of the condensation detection signal. Based on the above basic structure, the water droplet detection sensor 4 can be replaced with fiber optic or infrared reflective non-contact water droplet detection sensors according to special installation scenarios. At the same time, temperature and humidity sensors and shell temperature sensors can be added to build a multi-dimensional monitoring system to achieve dual protection of condensation prediction and early warning and real-time detection.

[0032] The control unit controls the low-pressure heating device 3 based on the detection signal from the water droplet detection sensor 4. The signal output terminal of the water droplet detection sensor 4 is stably connected to the signal input terminal of the control unit, and the control output terminal of the control unit is reliably connected to the power supply circuit of the low-pressure heating device 3. Specifically, the core functions of the control unit include real-time acquisition of condensation detection signals, digital filtering and noise reduction processing, accurate judgment of condensation status logic, precise control of heating start and stop, and full-process fault monitoring and fault reporting protection. It can adaptively switch between two heating control modes: open-loop fixed duration and closed-loop real-time detection, adapting to different temperatures, humidity levels, and vehicle operating conditions. The control unit prioritizes reusing the existing VCU or the motor controller MCU5 built into the drive motor controller of the vehicle, eliminating the need for additional independent control hardware, significantly reducing hardware development costs, wiring harness layout complexity, and program development cycle. The control logic design fully meets the requirements of automotive functional safety ASIL-B level, ensuring stable operation and strong anti-interference capabilities. The core interfaces of the control unit have clearly defined functions. The signal input end is dedicated to receiving the condensation detection signal from the water droplet detection sensor 4. After filtering and noise reduction, it eliminates electromagnetic interference and false triggering signals caused by signal fluctuations. The signal output end is dedicated to connecting to the controllable switch of the power supply circuit of the low-voltage heating device 3. At the same time, a CAN bus communication interface is reserved, which can upload the cavity condensation working status, heating operation status, and fault alarm information to the vehicle controller in real time, and simultaneously feed back to the vehicle instrument panel to provide visual prompts to the driver. Based on actual adaptation needs, the control unit can be equipped with an independent automotive-grade single-chip microcomputer control chip to adapt to upgrade scenarios where the older models have insufficient controller computing power and do not require modification of the original vehicle main control program. It can also be equipped with AI optimization algorithms to optimize the heating strategy based on vehicle operating conditions and ambient temperature. Combined with current and temperature detection circuits, it can achieve comprehensive fault redundancy protection, improving the overall safety and intelligence level of the device.

[0033] A method for removing condensation inside a motor controller includes the following steps: S1, Real-time monitoring initialization: After the vehicle is powered on at low voltage, it covers the entire state of low voltage maintenance after the vehicle is turned off, low voltage wake-up when the vehicle is static at low temperature, and low voltage power supply during normal driving. The motor controller MCU5 or the vehicle VCU immediately completes the initialization and calibration of the detection port and control port, and continuously and uninterruptedly collects the output detection signal of the water droplet detection sensor 4 in real time. The monitoring work can be started without waiting for the controller to be powered on at high voltage, realizing full coverage of condensation monitoring in all working conditions and all time periods of the vehicle, with no monitoring gaps. S2, Condensation State Judgment: The control unit performs digital filtering, threshold calibration, and anti-interference processing on the collected sensor raw signals to eliminate signal fluctuation errors caused by vibration and electromagnetic interference, and accurately judges the actual condensation state of the cavity's condensation-prone areas; if the sensor signal does not reach the preset condensation trigger threshold, it is determined that there are no liquid condensation droplets in the cavity, and it automatically returns to S1 for continuous loop monitoring, without starting the heating operation to reduce low-pressure energy consumption; if the sensor signal reaches the condensation trigger threshold, it accurately identifies that liquid condensation droplets have formed in the cavity, and immediately triggers the S3 heating execution step; S3, Heating Execution Start: The control unit immediately outputs a conduction control signal to the controllable switch of the power supply circuit, connecting the complete power supply circuit of the low-pressure heating device 3. The low-pressure heating device 3 quickly starts the heating operation, precisely heating the low-temperature areas prone to condensation, such as the attached drive motor controller housing 1 and controller cover 2. During the heating process, on the one hand, the condensed water droplets that have formed are quickly heated and evaporated into gaseous water vapor through heat conduction. The gaseous water vapor flows naturally along the airflow inside the cavity and is smoothly discharged from the controller cavity through the air pressure balance valve 10, thus achieving the active and thorough removal of the condensation. On the other hand, the surface temperature of the housing in the condensation-prone area is continuously increased, eliminating the local low-temperature core area inside the cavity, reducing the temperature difference inside the cavity, and fundamentally destroying the temperature conditions for water vapor condensation, preventing the continuous generation of new condensation, and achieving the dual effect of decondensation removal and anti-condensation. During the heating process, the control unit continuously collects signals from the water droplet detection sensor 4 in real time. The two control modes can be switched through preset settings in the vehicle program background. The optimal parameters are determined based on high and low temperature environment chamber simulation tests and full-road test of the vehicle. Mode 1, Open-loop fixed duration control: The optimal heating duration T (recommended range 3min~15min) is determined in advance by simulating different temperature and humidity conditions in the environmental chamber and conducting full-scenario road tests on the whole vehicle under different ambient temperatures. After the power supply is turned on, the control unit continues to heat until the preset fixed duration T, and then automatically disconnects the controllable switch to cut off the power supply to the low-voltage heating device 3, thus ending the current heating cycle. Mode 2, closed-loop real-time control: During the heating process, sensor signals are continuously collected to determine the condensation status in real time. When the sensor signal recovers to the no-condensation threshold (no condensation water droplets are detected), the control unit immediately disconnects the controllable switch, cuts off the power supply to the low-pressure heating device 3, and ends the current heating cycle. This achieves precise control of "stopping as soon as condensation is removed," reducing the low-pressure energy consumption of the entire vehicle. S4, Cyclic Monitoring and Protection Mechanism: After a single heating cycle, the device automatically resets to S1 for continuous routine condensation monitoring. If condensation risk is detected again, the entire process of condensation judgment and heating removal is automatically repeated. Simultaneously, it is equipped with multiple safety fault protection mechanisms to comprehensively ensure the electrical safety of the device and the entire vehicle. Overtime protection: If condensation is detected after a single heating cycle exceeds the maximum preset time (30 minutes recommended), the heating circuit will be automatically disconnected and the condensation fault will be reported to the vehicle's instrument panel to avoid the risk of overheating caused by component failure. Overheat protection: A temperature sensor is added to the heating circuit to monitor the surface temperature of the low-voltage heating device 3 in real time. When the temperature exceeds the safety threshold of 70℃, the power supply is immediately disconnected. Short circuit protection: The power supply circuit is equipped with an automotive-grade low-voltage fuse. When a short circuit fault occurs, the fuse will immediately blow and cut off the power supply to protect the vehicle's low-voltage electrical system.

[0034] In summary, for large commercial motor controllers and high-power new energy vehicle motor controllers with large-size drive motor controller housings 1, multi-corner low-temperature areas, and multiple high-condensity condensation points, this invention can adopt a multi-point distributed installation implementation scheme: At multiple independent condensation-prone locations on the inner wall of the drive motor controller housing 1 and the controller cover 2, dedicated low-pressure heating devices 3 and water droplet detection sensors 4 are separately installed. The sensor detection signal and heating device control circuit at each point are independently connected to the corresponding port of the control unit, enabling independent monitoring, judgment, and heating control at each monitoring and heating point, without interference or collaborative operation. When a condensation risk is detected at a single point, only the low-pressure heating device 3 at that point is activated for targeted heating, while other non-condensation points remain in standby monitoring mode, avoiding ineffective heating energy waste, significantly improving the accuracy and efficiency of condensation removal, truly achieving full-area, no-dead-angle, precise condensation prevention and control of the motor controller cavity, and comprehensively ensuring the long-term reliable and safe operation of the motor controller.

[0035] Although the present invention has been described above with reference to embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the invention. In particular, as long as there is no structural conflict, the features in the disclosed embodiments can be combined with each other in any manner. The lack of an exhaustive description of these combinations in this specification is merely for the sake of brevity and resource conservation. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A device for removing condensation inside a motor controller, comprising a drive motor controller housing (1) and a controller cover (2) disposed on the drive motor controller housing (1), wherein the drive motor controller housing (1) is respectively provided with a high-voltage copper busbar assembly (9), a pressure balancing valve (10), an IGBT power module (11), and a thin-film capacitor (12), characterized in that, Also includes: Water droplet detection sensor (4) is used to directly detect whether there are liquid condensation water droplets inside the motor controller; Low-pressure heating device (3) is used for directional heating of areas prone to condensation; The control unit is used to control the low-pressure heating device (3) to work according to the detection signal of the water droplet detection sensor (4). The signal output terminal of the water droplet detection sensor (4) is connected to the signal input terminal of the control unit, and the control output terminal of the control unit is connected to the power supply circuit of the low-pressure heating device (3).

2. The condensation removal device for the inside of a motor controller according to claim 1, characterized by, The water droplet detection sensor (4) is attached to the condensation-prone area on the inner wall of the drive motor controller housing (1) and the controller cover plate (2), and is arranged adjacent to or stacked with the low-pressure heating device (3).

3. The condensation removal device for the inside of a motor controller according to claim 2, characterized by, When the water droplet detection sensor (4) and the low-pressure heating device (3) are arranged adjacent to each other, the low-pressure heating device (3) and the water droplet detection sensor (4) are both attached to the condensation-prone areas of the inner wall of the drive motor controller housing (1) and the controller cover plate (2) through an adhesive layer (15). An insulating heat-conducting layer (14) is provided between the adhesive layer (15) and the drive motor controller housing (1) and the controller cover plate (2).

4. The condensation removal device for the inside of a motor controller according to claim 2, characterized by When the water droplet detection sensor (4) and the low-pressure heating device (3) are stacked and combined, the adhesive layer (15), the low-pressure heating device (3), the insulating heat-conducting layer (14) and the water droplet detection sensor (4) are arranged sequentially from the inner wall of the drive motor controller housing (1) and the controller cover plate (2) outwards, so that the sensing surface of the water droplet detection sensor (4) faces the inside of the cavity.

5. The condensation removal device for the inside of a motor controller according to claim 1, characterized by The power supply circuit of the low-pressure heating device (3) is equipped with a controllable switch, and the control unit controls the low-pressure heating device (3) by controlling the on and off of the controllable switch.

6. The condensation removal device for the inside of a motor controller according to claim 1, characterized by The power supply terminal of the low-voltage heating device (3) is connected to the low-voltage electrical input interface (7) and the control board voltage output port (8) located in the drive motor controller housing (1).

7. The condensation removal device for the inside of a motor controller according to claim 1, characterized by The control unit is a motor controller MCU (5) or a vehicle VCU, which can start monitoring and control when the vehicle is powered on at low voltage.

8. A method for removing condensation inside a motor controller, characterized by, Includes the following steps: S1, the control unit collects the detection signal of the water droplet detection sensor (4) in real time; S2, when the water droplet detection sensor (4) detects condensation, the control unit connects the power supply circuit of the low-pressure heating device (3) to heat it up and raise the temperature of the condensation area; S3, when the low-pressure heating device (3) is heating, the power-off timing is controlled by either an open-loop fixed duration mode or a closed-loop detection mode. S4, after heating is complete, return to S1 for continuous monitoring.

9. The method according to claim 8, wherein the method is characterized by, The open-loop fixed-duration mode is as follows: the optimal heating time is determined in advance through experiments, and the power supply is turned on and the heating continues until the preset time is reached before the power is automatically turned off. The closed-loop detection mode is as follows: continuously collect the signal of the water droplet detection sensor (4) until no condensation water droplets are detected, and then immediately disconnect the power supply.

10. The method according to claim 9, wherein the method is characterized by: During the heating process of the low-pressure heating device (3), an overtime protection, overheat protection and short circuit protection mechanism are added. If condensation is detected when heating exceeds the preset maximum duration and maximum temperature, the power supply is automatically disconnected and the fault is reported to the whole vehicle.

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