A compressor discharge temperature sensor fault degradation control method

Abstract

The present application relates to the technical field of thermal management, and belongs to a compressor exhaust temperature sensor fault degradation control method. In the compressor exhaust temperature sensor fault scenario, the present application realizes the complete logic of "fault tolerance-function degradation-safety protection" of the battery thermal management system, guarantees that the vehicle still has basic battery heating capacity under the fault working condition, and improves the system reliability and vehicle driving safety. It can significantly improve the safety, energy efficiency and user experience of the thermal management system. The present application dynamically judges the available state of various heat sources such as electric drive stall and waste heat when the sensor fails, automatically selects the optimal heating mode, and cooperatively controls the compressor speed, electronic condensing fan and air inlet grille, to realize the smooth degradation of system function instead of simple shutdown. Its advantages are: preferentially using low-energy heat sources to reduce invalid power consumption; through the strengthening of heat dissipation and speed limiting strategy, the core components such as the compressor are effectively protected to prevent overheating damage, and the reliability of the system is significantly improved.

Description

A method for degraded control due to compressor exhaust temperature sensor failure Technical Field

[0001] This invention relates to the field of thermal management technology, specifically a method for controlling the degradation of compressor exhaust temperature sensor failure. Background Technology

[0002] In thermal systems (such as automotive thermal management systems), the compressor exhaust temperature sensor is a key component ensuring precise system control and safe operation. Its function is to monitor the compressor exhaust temperature in real time, providing crucial temperature feedback for the thermal management system (TMS) to adjust battery modes and for the coordinated control of components such as the compressor, intelligent air intake grille (AGS), and fan. This ensures the system operates efficiently and stably within a reasonable temperature range, preventing system failures, performance degradation, and even safety hazards caused by abnormal temperatures.

[0003] However, existing technologies have significant drawbacks and shortcomings when dealing with compressor exhaust temperature sensor failures:

[0004] 1. Limited fault response: When a sensor fails, the existing control logic often only executes a simple "one-size-fits-all" shutdown or fixed degradation strategy, without fully considering the differentiated needs in battery mode. It is difficult to maintain thermal management efficiency to the maximum extent while ensuring the basic functions of the system, which can easily lead to significant fluctuations in vehicle cabin comfort and battery thermal management effect, and cannot adapt to complex and ever-changing actual use scenarios.

[0005] 2. Risk of Uncontrolled Component Coordination: There is a lack of precise and coordinated strategies for degraded control of related components such as compressors, AGS, and fans in case of failure. After a sensor failure, the components cannot coordinate effectively based on the remaining valid information in the system (such as data from other non-faulty sensors and historical system operating parameters). This may lead to problems such as compressors starting and stopping blindly, AGS opening not matching actual cooling needs, and inaccurate fan speed adjustments. This not only wastes energy but also exacerbates abnormal system wear and tear and may even trigger secondary failures.

[0006] 3. Ambiguous fault boundary conditions: Existing technologies lack clear and scientific judgment logic when defining the impact of sensor failures on the system's battery heating operation and the corresponding degradation control boundaries. For example, variables such as system load, and the detailed refrigerant mode switching threshold and battery thermal management protection mechanism after sensor failure, can lead to overly conservative degradation (severe functional limitations) or overly risky operation (increased safety risks) under certain operating conditions.

[0007] 4. Lack of dynamic self-adaptation capability: After a failure occurs in the existing technology, the degradation strategy is fixed and rigid, and cannot be optimized according to the real-time needs of the system. It cannot restore some functions of the thermal system as much as possible while ensuring reliability, which affects the energy efficiency of the whole vehicle and the user experience. Summary of the Invention

[0008] To address the aforementioned technical problems, this invention provides a method for degraded control of compressor exhaust temperature sensor failure.

[0009] To achieve the above objectives, the present invention provides the following technical solution:

[0010] This invention provides a method for degraded control of compressor exhaust temperature sensor failure, comprising the following steps:

[0011] S1. The underlying software monitors the status of the compressor exhaust temperature sensor in real time; if a fault is detected in the compressor exhaust temperature sensor, proceed to step S2.

[0012] S2. Determine the availability of heat sources in the current battery heating scenario. The heat sources include electric drive stalled rotor heat sources, electric drive waste heat heat sources, and battery heat pump heat sources.

[0013] S3. Based on the availability of the heat source, execute the corresponding degradation control strategy, including mode switching, compressor speed limiting, electronic condenser fan speed control, and active air intake grille (AGS) opening control.

[0014] Preferably, the determination of the availability of the heat source and the mode switching are as follows:

[0015] If the electric drive stalled heat source is available, maintain or switch to the electric drive stalled heating mode;

[0016] If the waste heat source of the electric drive is available, switch to the waste heat heating mode of the electric drive;

[0017] If both the electric drive stalled heat source and the electric drive waste heat source are unavailable, the system will enter battery heat pump heating mode and will degrade to shutdown mode in case of sensor failure.

[0018] Preferably, the determination of the availability of the electric drive stalled heat source includes:

[0019] For two-wheel drive vehicles, the front electric drive stall enable request is non-zero or the front electric drive stall heating level is non-zero.

[0020] For four-wheel drive vehicles, the stall enable request for both the front electric drive and the rear electric drive must be non-zero, or the heating gear must be non-zero.

[0021] Preferably, the criteria for determining the availability of the electric drive waste heat source include:

[0022] The difference between the electric drive inlet water temperature and the lowest battery temperature is greater than or equal to the first threshold.

[0023] The difference between the electric drive inlet water temperature and the battery target inlet water temperature is greater than or equal to the second threshold.

[0024] Preferably, in the electric drive stall mode: the compressor speed is limited to a maximum of 4000 rpm; the fan speed is running at full speed; and the active air intake grille (AGS) is fully open for heat dissipation.

[0025] Preferably, in the electric drive waste heat heating mode, the waste heat availability status is continuously monitored, and if the waste heat capacity decreases, the mode is dynamically switched to battery heat pump heating mode or off mode.

[0026] A thermal management system is provided for performing the above-described method. The thermal management system includes a vehicle thermal management controller, a compressor, an electronic condenser fan, an active air intake grille, and a compressor exhaust temperature sensor. The vehicle thermal management controller is signal-connected to the compressor, the compressor exhaust temperature sensor, the electronic condenser fan, and the active air intake grille, respectively.

[0027] A vehicle equipped with the aforementioned thermal management system.

[0028] Compared with the prior art, the present invention provides a method for degraded control of compressor exhaust temperature sensor failure, which has the following beneficial effects:

[0029] This invention implements a complete "fault tolerance - function degradation - safety protection" logic for the battery thermal management system in the event of a compressor exhaust temperature sensor failure. This ensures the vehicle retains basic battery heating capabilities even under fault conditions, improving system reliability and vehicle driving safety. It significantly enhances the safety, energy efficiency, and user experience of the thermal management system. By dynamically assessing the availability of various heat sources, such as electric drive stall and waste heat, when a sensor fails, this invention automatically selects the optimal heating mode and coordinates the control of compressor speed, electronic condenser fan, and air intake grille to achieve a smooth degradation of system function rather than a simple shutdown. Its advantages include: prioritizing the use of low-energy heat sources to reduce ineffective power consumption; and effectively protecting core components such as the compressor from overheating damage through enhanced heat dissipation and speed limiting strategies, thus significantly improving system reliability.

[0030] The features and advantages of the present invention will be described in detail through embodiments and in conjunction with the accompanying drawings. Attached Figure Description

[0031] Figure 1 is a flowchart of the fault degradation process of the exhaust temperature sensor of the present invention.

[0032] Figure 2 is a schematic diagram of the hardware relationship of the thermal management system of the present invention. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. However, it should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0034] Referring to Figures 1 and 2, a method for degraded control due to compressor exhaust temperature sensor failure includes the following steps:

[0035] S1. The underlying software monitors the status of the compressor exhaust temperature sensor in real time; if a fault is detected in the compressor exhaust temperature sensor, proceed to step S2.

[0036] S2. Determine the availability of heat sources in the current battery heating scenario. The heat sources include electric drive stalled rotor heat sources, electric drive waste heat heat sources, and battery heat pump heat sources.

[0037] S3. Based on the availability of the heat source, execute the corresponding degradation control strategy, including mode switching, compressor speed limiting, electronic condenser fan speed control, and active air intake grille (AGS) opening control.

[0038] Specifically, the determination of the availability of the heat source and the mode switching are as follows:

[0039] If the electric drive stalled heat source is available, maintain or switch to the electric drive stalled heating mode;

[0040] If the waste heat source of the electric drive is available, switch to the waste heat heating mode of the electric drive;

[0041] If both the electric drive stalled heat source and the electric drive waste heat source are unavailable, the system will enter battery heat pump heating mode and will degrade to shutdown mode in case of sensor failure.

[0042] Specifically, the determination of the availability of the electric drive stalled heat source includes:

[0043] For two-wheel drive vehicles, the front electric drive stall enable request is non-zero or the front electric drive stall heating level is non-zero.

[0044] For four-wheel drive vehicles, the stall enable request for both the front electric drive and the rear electric drive must be non-zero, or the heating gear must be non-zero.

[0045] Specifically, the conditions for determining the availability of the electric drive waste heat source include:

[0046] The difference between the electric drive inlet water temperature and the lowest battery temperature is greater than or equal to the first threshold.

[0047] The difference between the electric drive inlet water temperature and the battery target inlet water temperature is greater than or equal to the second threshold.

[0048] Specifically, in the electric drive stall mode: the compressor speed is limited to a maximum of 4000 rpm; the fan speed is running at full speed; and the active air intake grille (AGS) is fully open for heat dissipation.

[0049] Specifically, in the electric drive waste heat heating mode, the availability of waste heat is continuously monitored. If the waste heat capacity decreases, the mode is dynamically switched to battery heat pump heating mode or off mode.

[0050] A thermal management system is provided for performing the above-described method. The thermal management system includes a vehicle thermal management controller, a compressor, an electronic condenser fan, an active air intake grille, and a compressor exhaust temperature sensor. The vehicle thermal management controller is signal-connected to the compressor, the compressor exhaust temperature sensor, the electronic condenser fan, and the active air intake grille, respectively.

[0051] Referring to Figure 1, as further explanation, when the compressor exhaust temperature sensor malfunctions and the battery requests heating, the vehicle thermal management controller (TMS) initiates the battery heating mode determination process:

[0052] 1. The TMS continuously monitors the signal status of the compressor exhaust temperature sensor. If a sensor malfunction is detected (such as abnormal signal, no feedback, etc.), and the battery heating requirement is received from the battery management system (such as the battery temperature being lower than the threshold, or the need for preheating during charging / discharging), the battery heating mode decision logic is entered.

[0053] 2. Based on preset conditions (such as electric drive inlet water temperature, battery inlet water temperature, etc.), TMS determines the available heating sources and modes. Specific condition branches are as follows:

[0054] Electric drive waste heat heating determination (conditions A & B): If condition A (electric drive inlet water temperature - minimum battery temperature ≥ 8℃, calibrable) and condition B (electric drive inlet water temperature - target battery inlet water temperature ≥ 8℃, calibrable) are met, then TMS determines that the electric drive waste heat source is available and enters the electric drive waste heat heating mode.

[0055] Electric drive waste heat unusable determination (condition C or not satisfied with A&B): If condition C is satisfied (battery inlet water temperature - battery target inlet water temperature < -2℃, calibrable), or if conditions A&B are not satisfied, the TMS determines that the electric drive waste heat source is unusable and enters the secondary decision process of electric drive stall heating or heat pump heating.

[0056] If the electric drive stall heating decision process is initiated, the TMS further determines the availability of the electric drive stall heat source based on the vehicle's drive type (two-wheel drive / four-wheel drive) and electric drive status:

[0057] 1. Two-wheel drive condition determination (condition F ∨ G): When the two-wheel drive vehicle is in operation, if condition F (front electric drive stalled energy storage request ≠ 0) or condition G (front electric drive stalled heating position ≠ 0) is met, the electric drive stalled usable flag will be 1, and the electric drive stalled heat source will be determined to be usable.

[0058] 2. Four-wheel drive condition determination (condition F∨G) && (H∨I): When the vehicle is in four-wheel drive mode, both (condition F∨G) and (condition H∨I, rear electric drive stalled energy storage request ≠ 0 or rear electric drive stalled heating level ≠ 0) must be met simultaneously. The electric drive stalled usable flag is 1, and the electric drive stalled heat source is determined to be usable.

[0059] 3. Execution Logic: When the heat source from the stalled electric drive is determined to be available (meeting the above two-wheel drive / four-wheel drive conditions), the TMS controls the battery mode to remain in the stalled electric drive heating mode, limiting the compressor speed to ≤4000rpm, controlling the AGS to operate at full capacity for heat dissipation, and the electric condenser fan to run at 100% speed. In this mode, the heat generated by the stalled electric drive, combined with the heat dissipation regulation of the AGS and condenser fan (actually a coordinated heating cycle of the thermal management system), is used to heat the battery.

[0060] If the waste heat from the electric drive and the stalled heat source of the electric drive are both unavailable (the conditions for all heat sources to be available are not met), the system will enter battery heat pump heating mode. However, to ensure system safety, if the heat pump heating triggers a fault or the conditions are not met, the TMS will control the battery mode to downgrade to off, prohibiting the use of heat pump heating for the battery, and avoiding damage to components such as the compressor and battery due to forced heating.

[0061] The functions and synergistic effects of each component in the thermal management system are as follows:

[0062] The vehicle thermal management controller (TMS) acts as the "decision center." By collecting sensor signals and executing preset logic, it coordinates the operating status of the compressor, electric condenser fan, and AGS. In the event of sensor failure, it ensures the basic heating function of the battery thermal management system and balances heating demand with system safety.

[0063] Compressor: In the fault degradation mode, although the speed is limited (≤4000rpm), it still serves as the power source for the refrigerant cycle, and works with the waste heat from the electric drive and the heat from the stalled rotor to maintain the energy transfer of the battery heating cycle.

[0064] Electronic condenser fan: When running at 100% speed, it enhances the heat dissipation efficiency of the condenser, ensures that the refrigerant effectively releases heat during circulation, and provides a stable heat exchange basis for battery heating.

[0065] Active grille shutters (AGS): When fully open, they maximize air intake, assist airflow to the condenser, and improve heat dissipation (actually heat exchange in the heating cycle) efficiency. They work in conjunction with the electronic condenser fan to ensure the system's heat exchange capacity.

[0066] This invention implements a complete "fault tolerance - function degradation - safety protection" logic for the battery thermal management system in the event of a compressor exhaust temperature sensor failure. This ensures the vehicle retains basic battery heating capabilities even under fault conditions, improving system reliability and vehicle driving safety. It significantly enhances the safety, energy efficiency, and user experience of the thermal management system. By dynamically assessing the availability of various heat sources, such as electric drive stall and waste heat, when a sensor fails, this invention automatically selects the optimal heating mode and coordinates the control of compressor speed, electronic condenser fan, and air intake grille to achieve a smooth degradation of system function rather than a simple shutdown. Its advantages include: prioritizing the use of low-energy heat sources to reduce ineffective power consumption; and effectively protecting core components such as the compressor from overheating damage through enhanced heat dissipation and speed limiting strategies, thus significantly improving system reliability.

[0067] The present invention also proposes a vehicle having the above-described thermal management system.

[0068] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for degraded control due to a compressor exhaust temperature sensor failure, characterized in that: Includes the following steps: S1. The underlying software monitors the status of the compressor exhaust temperature sensor in real time. When a compressor exhaust temperature sensor malfunction is detected, proceed to step S2; S2: Determine the availability status of heat sources in the current battery heating scenario, including electric drive stalled rotor heat source, electric drive waste heat heat source and battery heat pump heat source; S3: Execute the corresponding degradation control strategy according to the availability status of the heat sources, including mode switching, compressor speed limit, electronic condenser fan speed control and active air intake grille AGS opening control.

2. The compressor exhaust temperature sensor fault degradation control method as described in claim 1, characterized in that: The determination of the availability of the heat source and the mode switching are as follows: if the electric drive stalled heat source is available, then maintain or switch to the electric drive stalled heating mode; if the electric drive waste heat source is available, then switch to the electric drive waste heat heating mode; if neither the electric drive stalled heat source nor the electric drive waste heat source is available, then enter the battery heat pump heating mode, and downgrade to the off mode when the sensor fails.

3. The compressor exhaust temperature sensor fault degradation control method as described in claim 2, characterized in that: The determination of whether the electric drive stall heat source is available includes: for two-wheel drive vehicles, the front electric drive stall enable request is non-zero or the front electric drive stall heating level is non-zero; for four-wheel drive vehicles, the stall enable request or heating level of both the front and rear electric drives must be non-zero at the same time.

4. The compressor exhaust temperature sensor fault degradation control method as described in claim 2, characterized in that: The conditions for determining whether the waste heat source of the electric drive is usable include: the difference between the electric drive inlet water temperature and the lowest battery temperature is greater than or equal to a first threshold; and the difference between the electric drive inlet water temperature and the target battery inlet water temperature is greater than or equal to a second threshold.

5. The compressor exhaust temperature sensor fault degradation control method as described in claim 2, characterized in that: In the electric drive stall heating mode: the compressor speed is limited to a maximum of 4000 rpm; the fan speed is running at full speed; and the active air intake grille (AGS) is fully open for heat dissipation.

6. The compressor exhaust temperature sensor fault degradation control method as described in claim 2, characterized in that: In the electric drive waste heat heating mode, the waste heat availability status is continuously monitored. If the waste heat capacity decreases, the mode is dynamically switched to battery heat pump heating mode or off mode.

7. A thermal management system, characterized in that, The thermal management system is used to perform the method as described in any one of claims 1 to 6. The thermal management system includes a vehicle thermal management controller, a compressor, an electronic condenser fan, an active air intake grille, and a compressor exhaust temperature sensor. The vehicle thermal management controller is signal-connected to the compressor, the compressor exhaust temperature sensor, the electronic condenser fan, and the active air intake grille, respectively.

8. A vehicle, characterized in that, Includes the thermal management system as described in claim 7.

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