Oil-cooled electric drive assembly of electric automobile and oil leakage detection strategy of oil-cooled electric drive assembly

Abstract

The invention relates to the field of electric vehicles, and discloses an oil-cooled electric drive assembly of an electric vehicle and an oil leakage detection strategy of the oil-cooled electric drive assembly. According to the detection strategy, whether the starting condition of oil leakage detection is met or not is firstly determined, if yes, an oil pump of the electric automobile is controlled to reach a preset rotating speed, if not, an end mark is judged, under the condition that the end mark is not received, first cumulative time is determined, and it is determined that oil leakage does not exist according to judgment of the first cumulative time and preset time. And other oil leakage conditions are judged according to other marks. According to the detection strategy, on the basis that an oil level sensor is not added, oil liquid in an oil cavity of the oil pump is diagnosed through the motor and the oil pump, oil leakage detection is started according to preset conditions, meanwhile, the oil pump carries out phase current detection, and whether the oil pump has an air suction fault or not is judged according to the magnitude of the phase current; the cost can be reduced, the oil leakage phenomenon can be detected and actively recognized in real time, and the running safety of the electric automobile is guaranteed.

Description

Technical Field

[0001] The present invention relates to the field of electric vehicles, and in particular to an oil-cooled electric drive assembly of an electric vehicle and an oil leakage detection strategy thereof. Background Art

[0002] Electric vehicles use the electric energy stored in batteries as energy supply, and have the characteristics of high efficiency, energy saving, low noise and zero emissions. They have incomparable advantages in energy saving and environmental protection, and have gradually become one of the important development trends in the automotive industry. As an important part of electric vehicles, the oil-cooled electric drive system includes oil-cooled accessories such as motor controllers, oil-cooled motors, reducers and oil pumps. The cooling oil is stored in the reducer. If oil leaks, it will not only affect the cooling of the motor and reducer, but the leaked oil may also get on the peripheral components of the electric drive, and in serious cases, it may cause the risk of combustion. The traditional solution for detecting oil is to add an oil level sensor, but this solution is not easy to implement in complex oil-cooled electric drives, and it is necessary to add hardware circuits to the motor controller, which has no advantages in terms of cost and space. In the prior art, there are built-in oil channels or anti-leakage oil sleeves to reduce the risk of oil leakage by eliminating external pipelines. However, they are all optimizations in mechanical structure and lack active diagnosis of oil leakage events. Summary of the invention

[0003] In order to achieve the above-mentioned purpose, the present invention provides an oil-cooled electric drive assembly of an electric vehicle and an oil leakage detection strategy thereof. The detection strategy can diagnose the oil in the oil chamber of an oil pump through a motor and an oil pump without adding an oil level sensor, and judge whether an oil leakage occurs based on the performance of the oil pump; and compared with the use of an oil level sensor or the addition of an anti-leakage oil pipeline, the strategy can reduce costs and space occupancy, can detect in real time, actively identify the occurrence of oil leakage, and ensure the safety of the operation of the electric vehicle.

[0004] In order to achieve the above object, the present invention provides, on one hand, a strategy for detecting oil leakage of an oil-cooled electric drive assembly of an electric vehicle, wherein the electric vehicle comprises a motor and an oil pump, and the detection strategy comprises:

[0005] Determine whether the start condition of oil leakage detection is currently met;

[0006] When it is determined that the start condition is currently met, controlling the oil pump of the electric vehicle to a preset speed;

[0007] Determining whether an end mark of the oil pump feedback is currently received;

[0008] In the case that the end mark is not currently received, determining a first accumulated time during which the end mark is not received;

[0009] Determining whether the first accumulated time is greater than or equal to a preset first time threshold;

[0010] When it is determined that the first accumulated time is greater than or equal to a preset first time threshold, it is determined that there is no oil leakage.

[0011] Preferably, determining whether the start condition of oil leakage detection is currently met includes:

[0012] Determine whether the oil pump has a fault report before starting;

[0013] In the case that the oil pump has no fault report before being turned on, determining whether the speed of the electric vehicle is between a preset first minimum speed and a first maximum speed, whether the oil temperature of the cooling oil of the oil pump is between a preset first minimum temperature and a first maximum temperature, and whether the absolute value of the driving slope of the electric vehicle is less than a preset first slope;

[0014] When the vehicle speed of the electric vehicle is between a preset first minimum vehicle speed and a first maximum vehicle speed, the oil temperature of the cooling oil of the oil pump is between a preset first minimum temperature and a first maximum temperature, and the absolute value of the driving slope of the electric vehicle is between the preset first slopes, it is determined that the start condition of the oil leakage detection is currently met.

[0015] Preferably, when it is determined that the start condition is currently met, controlling the oil pump of the vehicle to a preset speed includes:

[0016] After the oil pump reaches a preset speed, phase current detection is performed to determine whether a second accumulated time of the oil pump operation is greater than or equal to a preset second time threshold, and the first time threshold is greater than the second time threshold;

[0017] When the second accumulated operation time of the oil pump is greater than or equal to a preset second time threshold, the oil pump feeds back the end mark;

[0018] judging whether a vacuum fault occurs according to the phase current;

[0019] In the event of an air suction fault, the oil pump feeds back an air suction fault flag, the oil pump stops the phase current detection, and clears the second accumulated time;

[0020] When no cavitation failure occurs, the oil pump stops the phase current detection and clears the second accumulated time.

[0021] Preferably, determining whether an end mark of oil pump feedback is currently received includes:

[0022] Determine whether the termination condition is currently met;

[0023] When the termination condition is currently met, the oil leakage detection operation is terminated and the first accumulated time is cleared.

[0024] Preferably, determining whether the oil pump feedback end flag is currently received includes:

[0025] Determine whether the oil pump feedback air suction fault flag is currently received;

[0026] If no oil pump feedback suction failure mark is received, it is determined that there is no oil leakage;

[0027] When receiving the oil pump feedback suction fault sign, oil leakage is determined.

[0028] Preferably, determining whether the termination condition is currently met includes:

[0029] Determine whether there is a fault report when the oil pump performs oil leakage detection;

[0030] In the case where a fault is reported when the oil pump is performing oil leakage detection, it is determined that the termination condition is met; it is determined whether the speed of the electric vehicle is less than a preset second minimum speed or greater than a second maximum speed, the second minimum speed is less than the first minimum speed, and the second maximum speed is greater than the first maximum speed;

[0031] When the speed of the electric vehicle is less than a preset second minimum speed or greater than a preset second maximum speed, it is determined that the termination condition is met.

[0032] Preferably, determining whether the termination condition is currently met includes:

[0033] Determining whether the oil temperature of the cooling oil of the oil pump is lower than a preset second minimum temperature or higher than a second maximum temperature, the second minimum temperature being lower than the first minimum temperature, and the second maximum temperature being higher than the first maximum temperature;

[0034] When the oil temperature of the cooling oil of the oil pump is lower than a preset second minimum temperature or higher than a preset second maximum temperature, it is determined that the termination condition is satisfied.

[0035] Preferably, determining whether the termination condition is currently met includes:

[0036] Determining whether the absolute value of the driving slope of the electric vehicle is greater than a preset second slope, and whether the second slope is greater than the first slope;

[0037] When the absolute value of the driving slope of the electric vehicle is greater than a preset second slope, it is determined that the termination condition is met.

[0038] Preferably, the electric vehicle obtains the oil leakage condition of the oil leakage detection only once in each driving cycle.

[0039] A second aspect of the present invention provides an oil-cooled electric drive assembly for an electric vehicle, the oil-cooled electric drive assembly comprising:

[0040] Motor controller;

[0041] An oil-cooled motor, the oil-cooled motor being electrically connected to the motor controller;

[0042] A reducer, the reducer being drivingly connected to the oil-cooled motor;

[0043] An oil pump, wherein the oil pump pipeline is connected to the oil-cooled motor and the reducer;

[0044] The motor controller is used to execute any detection strategy as described above.

[0045] Through the above technical scheme, the detection strategy can diagnose the oil in the oil chamber of the oil pump through the motor and the oil pump without adding an oil level sensor, start the oil leakage detection according to the preset conditions, and at the same time the oil pump performs phase current detection, so that the oil pump can judge whether the oil pump has an air suction failure according to the phase current after detection. Compared with the installation of oil level sensors or the addition of anti-leakage pipelines, it can reduce costs and space occupancy, can detect in real time, and actively identify the occurrence of oil leakage, thereby ensuring the safety of electric vehicle operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 is a flow chart of an oil leakage detection strategy for an oil-cooled electric drive assembly of an electric vehicle according to an embodiment of the present invention;

[0047] Figure 2 It is a schematic block diagram of judging the oil leakage detection start condition of an oil leakage detection strategy of an oil-cooled electric drive assembly of an electric vehicle according to one embodiment of the present invention;

[0048] Figure 3 It is a schematic block diagram of judging the oil pump feedback mark situation of an oil leakage detection strategy of an oil-cooled electric drive assembly of an electric vehicle according to an embodiment of the present invention;

[0049] Figure 4 A schematic block diagram of oil leakage determination of an oil-cooled electric drive assembly of an electric vehicle according to an embodiment of the present invention;

[0050] Figure 5-8 The present invention is a schematic block diagram of determining the oil leakage detection termination condition of an oil leakage detection strategy for an oil-cooled electric drive assembly of an electric vehicle according to an embodiment of the present invention. DETAILED DESCRIPTION

[0051] The specific implementation of the embodiment of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the embodiment of the present invention, and is not used to limit the embodiment of the present invention.

[0052] like Figure 1 Shown is a flow chart of an oil leakage detection strategy for an oil-cooled electric drive assembly of an electric vehicle according to an embodiment of the present invention;

[0053] Electric vehicles include a set of motors and a set of oil pumps. Figure 1 The detection strategy may include the following steps:

[0054] In step S10, it is determined whether the start condition of oil leakage detection is currently met;

[0055] In step S11, when it is determined that the start condition is currently met, the oil pump of the electric vehicle is controlled to a preset speed;

[0056] In step S12, it is determined whether an end mark of the oil pump feedback is currently received;

[0057] In step S13, if the end mark is not currently received, determining a first accumulated time during which the end mark is not received;

[0058] In step S14, it is determined whether the first accumulated time is greater than or equal to a preset first time threshold;

[0059] In step S15 , when it is determined that the first accumulated time is greater than or equal to a preset first time threshold, it is determined that there is no oil leakage.

[0060] exist Figure 1 In step S10, firstly, according to the current speed, oil temperature and other data of the electric vehicle, it is determined whether the start condition of the oil leakage detection is met;

[0061] In step S11, when the electric vehicle meets the start-up conditions, the oil pump is regulated to reach a preset speed.

[0062] Step S12 determines whether an end mark of oil pump feedback is currently received.

[0063] Step S13, if the end mark is not currently received, determining a first accumulated time during which the end mark is not received;

[0064] Step S14 determines whether the first accumulated time is greater than or equal to a preset first time threshold;

[0065] In step S15, when it is determined that the first accumulated time is greater than or equal to the preset first time threshold, it is determined that there is no oil leakage.

[0066] Through the above strategy, the detection strategy can diagnose the oil in the oil chamber of the oil pump through the motor and the oil pump without adding an oil level sensor, start the oil leakage detection according to the preset conditions, and at the same time the oil pump performs phase current detection, so that the oil pump can judge whether the oil pump has an air suction failure according to the phase current after detection. Compared with the installation of oil level sensors or the addition of anti-leakage pipelines, it can reduce costs and space occupancy, can detect in real time, actively identify the occurrence of oil leakage, and ensure the safety of electric vehicle operation.

[0067] like Figure 2 The figure is a schematic block diagram of judging the oil leakage detection start condition of an oil leakage detection strategy for an oil-cooled electric drive assembly of an electric vehicle according to an embodiment of the present invention;

[0068] exist Figure 2 In the process, considering the start-up conditions that need to be met when the electric vehicle starts the oil leakage detection, it is determined whether the start-up conditions of the oil leakage detection are currently met, and feedback needs to be given according to the current vehicle condition. In one embodiment of the present invention, step S20 determines whether the oil pump has a fault report before being turned on. If there is a problem with the oil pump, subsequent phase current detection cannot be performed, so it is necessary to determine whether the oil pump has a fault report before being turned on;

[0069] Step S21, when the oil pump has no fault report before being turned on, determines whether the speed of the electric vehicle is between a preset first minimum speed and a preset first maximum speed, whether the oil temperature of the cooling oil of the oil pump is between a preset first minimum temperature and a preset first maximum temperature, and whether the absolute value of the driving slope of the electric vehicle is less than a preset first slope. The turning-on condition needs to satisfy multiple conditions coexisting.

[0070] In step S22, the start condition is met only when the vehicle speed of the electric vehicle is between a preset first minimum speed and a first maximum speed, the oil temperature of the cooling oil of the oil pump is between a preset first minimum temperature and a first maximum temperature, and the absolute value of the driving slope of the electric vehicle is between the preset first slopes.

[0071] like Figure 3 FIG. 1 is a schematic block diagram of a fuel pump feedback sign for an oil leakage detection strategy for an oil-cooled electric drive assembly of an electric vehicle according to an embodiment of the present invention. Figure 3 In the embodiment of the present invention, considering that the motor can perform oil leakage detection and judgment only after receiving feedback from the oil pump, the oil pump needs to perform phase current detection before feeding back a flag to the motor.

[0072] Step S30 performs phase current detection after the oil pump reaches a preset speed and determines whether the second accumulated time of the oil pump operation is greater than or equal to the preset second time threshold, and the first time threshold is greater than the second time threshold, so that the phase current detection time of the oil pump needs to be greater than the preset second time threshold to produce a feedback result. At the same time, the first time threshold is greater than the second time threshold to avoid turning off the oil leakage detection when the motor does not receive the feedback mark.

[0073] Step S31: When the second accumulated time of the oil pump operation is greater than or equal to a preset second time threshold, the oil pump feeds back an end flag;

[0074] Step S32 determines whether a vacuum failure occurs according to the phase current result after the oil pump performs phase current detection;

[0075] Step S33: In the event of an air suction fault, the oil pump feeds back an air suction fault flag, and at the same time the oil pump stops phase current detection and clears the second accumulated time;

[0076] In step S34, when no air suction failure occurs, the oil pump stops phase current detection and clears the second accumulated time.

[0077] like Figure 4 The figure is a schematic block diagram of oil leakage discrimination of an oil-cooled electric drive assembly oil leakage detection strategy of an electric vehicle according to an embodiment of the present invention; considering that the electric vehicle needs to maintain a certain vehicle condition during the process of receiving the feedback end mark, the test of the termination condition is a real-time test, therefore, in an embodiment of the present invention, step S40 determines whether the current vehicle condition meets the termination condition, and at this time, it is also determined whether the end mark of the oil pump feedback is received;

[0078] In step S41, when the termination condition is currently met, the electric vehicle ends the oil leakage detection operation and clears the first accumulated time.

[0079] exist Figure 4 In the embodiment of the present invention, it is considered that when the motor receives the end mark of the oil pump feedback, it is necessary to report whether oil leakage occurs according to the received suction failure mark. Therefore, in one embodiment of the present invention,

[0080] Step S50 determines whether the current motor receives an air suction fault flag fed back by the oil pump;

[0081] Step S51: When the motor does not receive the suction fault flag fed back by the oil pump, the motor reports to confirm that the oil pump is not leaking oil;

[0082] In step S52, when the motor receives the suction fault flag fed back by the oil pump, it is determined that the oil pump has an oil leakage fault.

[0083] Figure 5-8The present invention is a schematic block diagram of the judgment of the oil leakage detection termination condition of the oil-cooled electric drive assembly oil leakage detection strategy of an electric vehicle according to an embodiment of the present invention. In the figure, considering that the oil pump will affect the oil leakage detection when the vehicle condition changes during the detection process, in order to ensure the accuracy of the detection, the oil leakage detection needs to be terminated; therefore, in one embodiment of the present invention, it is necessary to judge whether the termination condition is currently met based on the current vehicle condition. The termination conditions to be judged include:

[0084] Determine whether there is a fault report when the oil pump is performing oil leakage detection. If there is a fault report when the oil pump is performing oil leakage detection, the current vehicle condition meets the termination condition;

[0085] Determine whether the speed of the electric vehicle is less than a preset second minimum speed or greater than a second maximum speed, the second minimum speed is less than the first minimum speed, and the second maximum speed is greater than the first maximum speed, and when the speed of the electric vehicle is less than the preset second minimum speed or greater than the second maximum speed, the current vehicle condition meets the suspension condition;

[0086] Determine whether the oil temperature of the cooling oil of the oil pump is lower than a preset second minimum temperature or higher than a second maximum temperature, the second minimum temperature is lower than the first minimum temperature, and the second maximum temperature is higher than the first maximum temperature, and when the oil temperature of the cooling oil of the oil pump is lower than the preset second minimum temperature or higher than the second maximum temperature, the current vehicle condition satisfies the termination condition;

[0087] It is determined whether the absolute value of the driving slope of the electric vehicle is greater than a preset second slope, and the second slope is greater than the first slope. When the absolute value of the driving slope of the electric vehicle is greater than the preset second slope, the current vehicle condition meets the termination condition.

[0088] If one of the current vehicle conditions, such as vehicle speed, cooling oil temperature, oil pump, or the slope of the electric vehicle, meets the preset conditions, the oil leak detection will be terminated.

[0089] Considering the running conditions of the vehicle and the process of oil leakage detection, in one embodiment of the present invention, the electric vehicle only obtains the oil leakage condition of the oil leakage detection once in each driving cycle, and the detection result is recorded. A new oil leakage detection can only be performed after the electric vehicle is restarted. This method helps to ensure the accuracy of the detection while avoiding excessive use of the equipment or system of the electric vehicle.

[0090] A second aspect of the present invention provides an oil-cooled electric drive assembly for an electric vehicle, the oil-cooled electric drive assembly comprising a motor controller, an oil-cooled motor, a reducer, and an oil pump; the oil-cooled motor is electrically connected to the motor controller, the reducer is transmission-connected to the oil-cooled motor, and the oil pump pipeline connects the oil-cooled motor and the reducer. The motor controller can be used to execute any of the detection strategies described above to achieve oil leakage detection of the oil pump by the oil-cooled electric drive assembly.

[0091] Through the above technical scheme, the detection strategy can diagnose the oil in the oil chamber of the oil pump through the motor and the oil pump without adding an oil level sensor, start the oil leakage detection according to the preset conditions, and at the same time the oil pump performs phase current detection, so that the oil pump can judge whether the oil pump has an air suction failure according to the phase current after detection. Compared with the installation of oil level sensors or the addition of anti-leakage pipelines, it can reduce costs and space occupancy, can detect in real time, and actively identify the occurrence of oil leakage, thereby ensuring the safety of electric vehicle operation.

[0092] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0093] The above are only embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included within the scope of the claims of the present application.

Claims

1. An oil leakage detection strategy for an oil-cooled electric drive assembly of an electric vehicle, the electric vehicle comprising a motor and an oil pump, characterized in that: The detection strategy includes: Determine whether the start condition of oil leakage detection is currently met; When it is determined that the start condition is currently met, controlling the oil pump of the electric vehicle to a preset speed; Determining whether an end mark of the oil pump feedback is currently received; In the case that the end mark is not currently received, determining a first accumulated time during which the end mark is not received; Determining whether the first accumulated time is greater than or equal to a preset first time threshold; When it is determined that the first accumulated time is greater than or equal to a preset first time threshold, it is determined that there is no oil leakage.

2. The detection strategy according to claim 1, characterized in that: Determine whether the current conditions for oil leak detection are met, including: Determine whether the oil pump has a fault report before starting; In the case that the oil pump has no fault report before being turned on, determining whether the speed of the electric vehicle is between a preset first minimum speed and a first maximum speed, whether the oil temperature of the cooling oil of the oil pump is between a preset first minimum temperature and a first maximum temperature, and whether the absolute value of the driving slope of the electric vehicle is less than a preset first slope; When the vehicle speed of the electric vehicle is between a preset first minimum vehicle speed and a first maximum vehicle speed, the oil temperature of the cooling oil of the oil pump is between a preset first minimum temperature and a first maximum temperature, and the absolute value of the driving slope of the electric vehicle is between the preset first slopes, it is determined that the start condition of the oil leakage detection is currently met.

3. The detection strategy according to claim 2, characterized in that: When it is determined that the start condition is currently met, the oil pump of the vehicle is controlled to a preset speed, including: After the oil pump reaches a preset speed, phase current detection is performed to determine whether a second accumulated time of the oil pump operation is greater than or equal to a preset second time threshold, and the first time threshold is greater than the second time threshold; When the second accumulated operation time of the oil pump is greater than or equal to a preset second time threshold, the oil pump feeds back the end mark; judging whether a vacuum fault occurs according to the phase current; In the event of an air suction fault, the oil pump feeds back an air suction fault flag, the oil pump stops the phase current detection, and clears the second accumulated time; When no cavitation failure occurs, the oil pump stops the phase current detection and clears the second accumulated time.

4. The detection strategy according to claim 3, characterized in that: The end flag for judging whether the oil pump feedback is currently received includes: Determine whether the termination condition is currently met; When the termination condition is currently met, the oil leakage detection operation is terminated and the first accumulated time is cleared.

5. The detection strategy according to claim 4, characterized in that: Determine whether the oil pump feedback end flag is currently received, including: Determine whether the oil pump feedback emptying fault flag is currently received; If no oil pump feedback suction failure mark is received, it is determined that there is no oil leakage; When receiving the oil pump feedback suction fault sign, oil leakage is determined.

6. The detection strategy according to claim 4, characterized in that: Determining whether the current termination conditions are met includes: Determine whether there is a fault report when the oil pump performs oil leakage detection; In the case where a fault is reported when the oil pump is performing oil leakage detection, determining that a termination condition is met; Determining whether the speed of the electric vehicle is less than a preset second minimum speed or greater than a second maximum speed, the second minimum speed being less than the first minimum speed, and the second maximum speed being greater than the first maximum speed; When the speed of the electric vehicle is less than a preset second minimum speed or greater than a preset second maximum speed, it is determined that the termination condition is met.

7. The detection strategy according to claim 4, characterized in that: Determine whether the current termination conditions are met, including: Determining whether the oil temperature of the cooling oil of the oil pump is lower than a preset second minimum temperature or higher than a second maximum temperature, the second minimum temperature being lower than the first minimum temperature, and the second maximum temperature being higher than the first maximum temperature; When the oil temperature of the cooling oil of the oil pump is lower than a preset second minimum temperature or higher than a preset second maximum temperature, it is determined that the termination condition is satisfied.

8. The detection strategy according to claim 4, characterized in that: Determine whether the current termination conditions are met, including: Determining whether the absolute value of the driving slope of the electric vehicle is greater than a preset second slope, and whether the second slope is greater than the first slope; When the absolute value of the driving slope of the electric vehicle is greater than a preset second slope, it is determined that the termination condition is met.

9. The detection strategy according to claim 1, characterized in that: The electric vehicle obtains the oil leakage condition of the oil leakage detection only once in each driving cycle.

10. An oil-cooled electric drive assembly for an electric vehicle, characterized in that: The oil-cooled electric drive assembly includes: Motor controller; An oil-cooled motor, the oil-cooled motor being electrically connected to the motor controller; A reducer, the reducer being drivingly connected to the oil-cooled motor; An oil pump, wherein the oil pump pipeline is connected to the oil-cooled motor and the reducer; The motor controller is used to execute the detection strategy as described in any one of claims 1 to 9.

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