Electronic oil pump over-temperature robustness improvement diagnosis method

Abstract

The invention discloses an electronic oil pump over-temperature robustness improvement diagnosis method which comprises the steps that S1, the temperature of an electronic oil pump is monitored in real time, and if an over-temperature fault condition is met, shutdown is executed, and the cumulative recovery frequency P is added with 1; s2, judging whether the accumulated recovery frequency P is greater than a preset maximum recovery frequency K or not: if P is greater than K, reporting a permanent over-temperature fault; if P < = K, waiting for the temperature to meet a recovery condition; s3, after the recovery condition is met, whether the accumulated recovery frequency P is larger than the upper limit M of the conventional recovery frequency or not is judged, M is smaller than K, and if P is smaller than or equal to M, the electronic oil pump is restarted to rotate forwards; and if P is larger than M, according to the preset temperature interval to which the peak temperature Ttop recorded in the over-temperature fault belongs, executing the reverse rotation operation of the electronic oil pump according to the reverse rotation strength level corresponding to the temperature interval to which the electronic oil pump belongs, and after the reverse rotation operation lasts for a preset duration, recovering the forward rotation operation of the electronic oil pump. The method is high in fault-tolerant capability and capable of achieving active reverse regulation and control, and the working robustness of the electronic oil pump is improved.

Description

Technical Field

[0001] This invention relates to the field of electronic oil pump over-temperature detection technology, and in particular to a method for improving the robustness of electronic oil pump over-temperature diagnosis. Background Technology

[0002] Currently, in new energy oil-cooled electric drive systems, the industry generally adopts a simple diagnostic strategy based on a fixed threshold for over-temperature protection of electronic oil pumps. Its core idea is single-point triggering and single-point recovery, aiming to prevent pump damage due to high temperatures through the most direct temperature monitoring.

[0003] The specific implementation process of existing technical solutions is generally as follows: Fault Trigger (Shutdown): The system monitors the temperature of the electronic oil pump in real time (usually through a built-in temperature sensor) and sets a fixed over-temperature fault threshold (e.g., 150℃). When the monitored temperature reaches or exceeds 150℃ for a specific time (e.g., 1 second), the control system immediately reports the over-temperature fault and executes preset protection actions, usually immediately stopping the operation of the electronic oil pump to avoid damage to the equipment at high temperatures. Fault Recovery (Restart): After the oil pump stops, since it no longer generates heat and is in a cooling environment, the temperature begins to drop naturally. A fixed fault recovery threshold (e.g., 140℃) is usually set. This threshold must be lower than the fault threshold to create a "hysteresis" to prevent frequent jumps. When the monitored temperature drops below 140℃ for a specific time (e.g., 1 second), the system determines that the fault condition has been resolved, clears the fault state, and allows or directly restarts the electronic oil pump.

[0004] Although existing technical solutions are simple, reliable, and easy to implement, they suffer from insufficient robustness, which manifests in the following two aspects: 1. Lack of fault tolerance mechanisms leads to high after-sales costs. Existing technical solutions typically employ a rigid "single-trigger, immediate reporting" strategy. Once the over-temperature condition is met, the system immediately reports a fault and initiates a shutdown. This strategy lacks any fault tolerance or buffering mechanism. For many self-recoverable short-term operating conditions (such as brief large load shocks or instantaneous disturbances in the lubrication circuit), the system cannot distinguish them from genuine hardware faults and reports them all as serious faults. This directly results in a high false alarm rate, increasing owner anxiety, triggering unnecessary after-sales repairs and component replacements, and increasing the OEM's after-sales maintenance costs.

[0005] 2. Fault recovery is relatively passive, lacking proactive intervention to improve the recovery probability. In the fault recovery process, existing solutions rely entirely on the passive reduction of temperature, without any proactive physical intervention. Therefore, when overheating is caused by foreign objects in the oil passages leading to increased operating load, passive restarting cannot change the state of foreign object obstruction, easily causing the oil pump to overheat again after restarting, falling into a fault cycle, and failing to effectively improve the recovery probability of such problems. Summary of the Invention

[0006] To address the technical problems existing in the background art, this invention proposes a diagnostic method for improving the over-temperature robustness of electronic oil pumps.

[0007] This invention proposes a diagnostic method for improving the over-temperature robustness of electronic oil pumps, the method comprising: S1. Monitor the temperature of the electronic oil pump in real time. If the over-temperature fault condition is met, execute the shutdown and increment the cumulative number of recovery times P by 1. S2. Determine whether the cumulative number of recovery attempts P is greater than the preset maximum number of recovery attempts K: If P > K, then report a permanent over-temperature fault; if P ≤ K, then wait for the temperature to meet the recovery conditions. S3. After the recovery conditions are met, determine whether the cumulative number of recovery attempts P is greater than the upper limit of the normal number of recovery attempts M, where M < K: If P≤M, the electronic oil pump will restart in forward rotation. If P>M, the electronic oil pump will reverse according to the preset temperature range to which the peak temperature Ttop recorded in this over-temperature fault belongs. After the reverse operation continues for a preset time, the electronic oil pump will resume in forward rotation.

[0008] Furthermore, the maximum number of recovery attempts K is equal to the sum of the upper limit of the number of normal recovery attempts M and the maximum number of reverse recovery attempts N allowed to be performed, i.e., K = M + N.

[0009] Furthermore, the over-temperature fault condition is: the temperature of the electronic oil pump reaches a first preset value for a duration, and the temperature is not less than a first temperature threshold.

[0010] Furthermore, the recovery condition is: the temperature of the electronic oil pump reaches a second preset value for a certain duration, and the temperature is not greater than a second temperature threshold.

[0011] Furthermore, the preset temperature range includes at least two ranges, each corresponding to a different reversal intensity level.

[0012] Furthermore, the reversal intensity level is expressed as a percentage of the peak rotational speed of the electronic oil pump, and the percentage increases as the temperature value of the preset temperature range increases.

[0013] Furthermore, the preset temperature range includes three ranges, wherein the first temperature range is 150℃≤Ttop<152℃; the second temperature range is 152℃≤Ttop<154℃; and the third temperature range is Ttop≥154℃.

[0014] Furthermore, the reversal intensity level corresponding to the first temperature range is 30% of the peak speed of the electric oil pump; the reversal intensity level corresponding to the second temperature range is 60% of the peak speed of the electric oil pump; and the reversal intensity level corresponding to the third temperature range is 90% of the peak speed of the electric oil pump.

[0015] Furthermore, the resumption of forward operation of the electronic oil pump in S3 is performed after the reverse operation ends and after a preset third preset value interval.

[0016] Furthermore, in S1, a pre-shutdown fault position is reported while the shutdown is being executed; in S2, if P≤K, the pre-shutdown fault state is cleared before or simultaneously while waiting for the temperature to meet the recovery conditions.

[0017] This invention introduces a segmented recovery fault-tolerant mechanism, allowing the system to automatically attempt recovery from over-temperature conditions within a limited number of attempts. This effectively distinguishes between short-term disturbances and genuine faults, reducing false alarm rates and after-sales costs. During the recovery attempt, different intensities of active reverse clearing actions are intelligently matched based on the severity of the over-temperature (peak temperature). This effectively disturbs the oil circuit, increasing the recovery probability of faults caused by minor blockages in the oil circuit, and significantly improving the robustness of the electronic oil pump. Attached Figure Description

[0018] Figure 1 This is a flowchart of a diagnostic method for improving the over-temperature robustness of an electronic oil pump, as proposed in this invention. Detailed Implementation

[0019] The technical solution of the present invention will now be described in detail with reference to the accompanying drawings and embodiments. The embodiments are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operating procedures. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them, and the scope of protection of the present invention is not limited to the following embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0020] This embodiment provides a diagnostic method for improving the over-temperature robustness of electronic oil pumps, applied to the cooling and lubrication electronic oil pumps of electric drive systems in new energy vehicles. For example... Figure 1 The flowchart shown includes the following methods: S1, Fault Triggering and Status Reporting.

[0021] The controller monitors the temperature of the electronic oil pump in real time. In this embodiment, the over-temperature fault condition is set as follows: the temperature duration of the electronic oil pump reaches 1 second (the first preset value), and the temperature is not less than 150 °C (the first temperature threshold). If the over-temperature fault condition is met, the controller immediately executes shutdown protection and increments the cumulative recovery count P by 1 (i.e., P = P + 1). In this embodiment, the controller also reports an internal pre-shutdown fault flag while shutting down to indicate that the over-temperature fault state has been entered currently.

[0022] S2. Judgment of the recovery count.

[0023] The controller presets a maximum recovery count K, for example, K = 10. It is judged whether the cumulative recovery count P is greater than the preset maximum recovery count K: If P > K, it is determined as an irrecoverable permanent fault, and the controller reports a permanent over-temperature fault and maintains the shutdown; If P ≤ K, wait for the temperature to meet the recovery condition. In this embodiment, the recovery condition is set as follows: the temperature duration of the electronic oil pump reaches 1 second (the second preset value), and the temperature is not greater than 140 °C (the second temperature threshold). Moreover, before or simultaneously waiting for the temperature to meet the recovery condition, the controller clears the pre-shutdown fault flag reported in step S1, indicating that the system will attempt to recover.

[0024] S3. Recovery decision-making and execution.

[0025] After the recovery condition is met, the controller makes a recovery decision. A preset upper limit M for the normal recovery count is set, M < K, for example, M = 5. It is judged whether the cumulative recovery count P is greater than the upper limit M of the normal recovery count: If P ≤ M, the controller restarts the electronic oil pump and makes it run forward; If P > M, the controller controls the electronic oil pump to enter a recovery mode with reverse rotation. The controller retrieves the peak temperature Ttop recorded in this over-temperature fault. According to the preset temperature range of the peak temperature Ttop, corresponding reverse operations are executed.

[0026] In this embodiment, three temperature ranges (i.e., at least two ranges) are preset. For example, the first temperature range is 150 °C ≤ Ttop < 152 °C; the second temperature range is 152 °C ≤ Ttop < 154 °C; the third temperature range is Ttop ≥ 154 °C. Each temperature range corresponds to a different reverse rotation intensity level of the electronic oil pump. For example, the first, second, and third temperature ranges respectively correspond to low, medium, and high intensities. The controller controls the electronic oil pump to execute reverse rotation operation according to the selected intensity level. After the reverse rotation operation lasts for a preset duration (such as 3 seconds), after an interval of a preset third preset value (such as 1 second), the forward rotation of the electronic oil pump is restored.

[0027] In this embodiment, the maximum number of recovery attempts K is equal to the sum of the upper limit of the number of normal recovery attempts M and the maximum number of reverse recovery attempts N allowed to be performed, i.e., K=M+N, where N=5.

[0028] Furthermore, in a specific embodiment, the reversal intensity level is further defined. The reversal intensity level is expressed as a percentage of the peak speed of the electronic oil pump. The higher the percentage value, the greater the reversal intensity. Moreover, the percentage increases with the increase of the temperature value in the preset temperature range, that is, for higher over-temperature peaks, a stronger reversal is used to attempt to clear the obstruction.

[0029] Furthermore, in a specific embodiment, the preset temperature range and the reversal intensity level correspond as follows: The first temperature range corresponds to a reversal intensity level of 30% of the peak speed of the electric oil pump; the second temperature range corresponds to a reversal intensity level of 60% of the peak speed of the electric oil pump; and the third temperature range corresponds to a reversal intensity level of 90% of the peak speed of the electric oil pump.

[0030] When the electric oil pump rotates forward, it drives the cooling oil to circulate in the forward direction. If small solid foreign objects (such as metal shavings, sealant debris, etc.) are present in the oil circuit, they may become stuck in the filter, narrow oil passages, or inside the pump body, increasing operating resistance (load) and leading to overheating. When reversing, the oil pump drives the cooling oil to flow in the opposite direction. This sudden change in flow direction generates a fluid impact force and mechanical force on the stuck foreign objects, opposite to the previous forward flow direction. This may loosen them, dislodge them from their stuck position, or flush them back to a larger contaminant-holding area (such as the oil pan), thereby relieving or reducing oil flow blockage and lowering the load on the oil pump during subsequent forward operation.

[0031] This embodiment uses the reverse rotation of the electronic oil pump to disturb the oil circuit, loosening tiny foreign objects obstructing oil flow and changing their stuck positions. This could potentially restore normal oil flow and reduce the operating load on the oil pump. Different intensities of reverse rotation can intelligently address varying degrees of increased operating load caused by foreign objects. Higher reverse rotation intensity provides stronger reverse oil flow impact force to cope with potentially more stubborn foreign object blockages (manifested as higher peak temperatures), increasing the system's recovery probability.

[0032] It should also be noted that the specific temperature thresholds, durations, frequency, percentages, etc. mentioned above are just examples and can be adjusted according to the specific pump type and system requirements.

[0033] This invention abandons the simplistic logic of "one overheating equals a failure" and introduces a segmented recovery strategy based on the number of attempts, giving the system the fault tolerance capability of multiple "restart attempts," thereby achieving the technical effects of increasing fault tolerance and reducing costs. For self-recoverable short-term faults, the system can automatically return to normal, significantly reducing the number of faults reported to the vehicle level and lowering after-sales return and repair costs.

[0034] Furthermore, the present invention introduces an active reversal action in the restart and recovery process, and can implement corresponding intensity control according to the severity of the fault (over-temperature peak), thereby achieving the technical effect of improving operating conditions and increasing the probability of recovery.

[0035] The term "an embodiment" or "embodiment" as used in this invention refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the invention. In the description of this invention, it should be understood that the terms "first," "second," and "third," etc., in the specification, claims, and accompanying drawings are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0036] This specification provides method operation steps as shown in the embodiments or flowcharts, but based on conventional or non-inventive labor, more or fewer operation steps may be included. The order of steps listed in the embodiments is merely one of many possible execution orders and does not represent the only possible execution order. In actual system or server product execution, the method can be executed in the order shown in the embodiments or drawings, or in parallel (e.g., in a parallel processor or multi-threaded processing environment), or the execution order of steps without timing constraints can be adjusted.

[0037] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A method for improving the robustness of an electronic oil pump in over-temperature testing, characterized in that the method... include: S1. Monitor the temperature of the electronic oil pump in real time. If the over-temperature fault condition is met, execute the shutdown and increment the cumulative number of recovery times P by 1. S2. Determine whether the cumulative number of recovery attempts P is greater than the preset maximum number of recovery attempts K: If P > K, then report a permanent over-temperature fault; if P ≤ K, then wait for the temperature to meet the recovery conditions. S3. After the recovery conditions are met, determine whether the cumulative number of recovery attempts P is greater than the upper limit of the normal number of recovery attempts M, where M < K: If P≤M, the electronic oil pump will restart in forward rotation. If P>M, the electronic oil pump will reverse according to the preset temperature range to which the peak temperature Ttop recorded in this over-temperature fault belongs. After the reverse operation continues for a preset time, the electronic oil pump will resume in forward rotation.

2. The method according to claim 1, characterized in that, The maximum number of recovery attempts K is equal to the sum of the upper limit of the number of regular recovery attempts M and the maximum number of reverse recovery attempts N allowed to be performed, i.e., K = M + N.

3. The method according to claim 1, characterized in that, The over-temperature fault condition is: the temperature of the electronic oil pump reaches a first preset value for a duration, and the temperature is not less than a first temperature threshold.

4. The method according to claim 1, characterized in that, The recovery condition is: the temperature of the electronic oil pump reaches a second preset value for a certain duration, and the temperature is not greater than a second temperature threshold.

5. The method according to claim 1, characterized in that, The preset temperature range includes at least two ranges, each corresponding to a different reversal intensity level.

6. The method according to claim 5, characterized in that, The reversal intensity level is expressed as a percentage of the peak speed of the electronic oil pump, and the percentage increases as the temperature value of the preset temperature range increases.

7. The method according to claim 6, characterized in that, The preset temperature range includes three ranges: the first temperature range is 150℃≤Ttop<152℃; the second temperature range is 152℃≤Ttop<154℃; and the third temperature range is Ttop≥154℃.

8. The method according to claim 7, characterized in that, The first temperature range corresponds to a reversal intensity level of 30% of the peak speed of the electric oil pump; the second temperature range corresponds to a reversal intensity level of 60% of the peak speed of the electric oil pump; and the third temperature range corresponds to a reversal intensity level of 90% of the peak speed of the electric oil pump.

9. The method according to claim 1, characterized in that, The resumption of forward operation of the electronic oil pump in S3 is performed after the reverse operation ends and after a preset third preset value interval.

10. The method according to claim 1, characterized in that, In S1, the pre-stop fault position is reported while the shutdown is executed; in S2, if P≤K, the pre-stop fault state is cleared before or at the same time as waiting for the temperature to meet the recovery condition.

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