Method, device and controller for detecting failure of electric pump, electric oil pump and vehicle

Abstract

The application discloses a kind of electric pump fault detection method, device and controller, electronic fuel pump, vehicle, wherein the electric pump fault detection method includes: obtaining the current feedback speed of electric pump motor, and obtaining the current cross-axis current of electric pump motor;According to the lower limit curve of pre-fitting dry running determination current and current feedback speed, determine minimum determination current;According to the relationship between current cross-axis current and minimum determination current, determine whether electric pump occurs dry running failure.By this, by calculating the minimum determination current corresponding to current feedback speed, and according to the relationship between current cross-axis current and minimum determination current, whether electric pump is in dry running state can be detected in time, so that electric pump is damaged to avoid electric pump long time in dry running state.

Description

Technical Field

[0001] This application relates to the field of electric pump technology, and in particular to a fault detection method, device and controller for an electric pump, an electronic oil pump, and a vehicle. Background Technology

[0002] During use, automotive electronic oil pumps may experience pipeline leaks, causing the pump to run dry (i.e., idling: the pump operates with no or less than 20% of the pumped medium). If the pump runs dry for an extended period, it will damage the electric pump. Summary of the Invention

[0003] This invention aims to at least partially solve one of the technical problems in related technologies. Therefore, the first objective of this invention is to propose a fault detection method for an electric pump. By calculating the minimum judgment current corresponding to the current feedback speed and based on the relationship between the current quadrature shaft current and the minimum judgment current, it is possible to detect in a timely manner whether the electric pump is in a dry-running state, thereby preventing damage to the electric pump caused by prolonged dry-running.

[0004] A second objective of this invention is to provide a computer-readable storage medium.

[0005] The third objective of this invention is to provide an electric pump controller.

[0006] The fourth objective of this invention is to provide a fault detection device for an electric pump.

[0007] The fifth objective of this invention is to provide an electronic oil pump.

[0008] The sixth objective of this invention is to provide a vehicle.

[0009] To achieve the above objectives, a fault detection method for an electric pump is proposed according to a first aspect embodiment of the present invention, comprising: acquiring the current feedback speed of the electric pump motor and acquiring the current quadrature shaft current of the electric pump motor; determining a minimum judgment current based on a pre-fitted dry running judgment current lower limit curve and the current feedback speed; and determining whether the electric pump has experienced a dry running fault based on the relationship between the current quadrature shaft current and the minimum judgment current.

[0010] According to the fault detection method for an electric pump of the present invention, the current feedback speed and current quadrature-axis current of the electric pump motor are first obtained. Then, a minimum judgment current is determined using a pre-fitted dry-run judgment current lower limit curve and the current feedback speed. Finally, the relationship between the current quadrature-axis current and the minimum judgment current is used to determine whether the electric pump has experienced a dry-run fault. Thus, by calculating the minimum judgment current corresponding to the current feedback speed (the minimum judgment current being the quadrature-axis current corresponding to the current feedback speed when the electric pump motor is in a dry-running state), and based on the relationship between the current quadrature-axis current and the minimum judgment current, it is possible to detect in a timely manner whether the electric pump is in a dry-running state, thereby preventing damage to the electric pump caused by prolonged dry-running.

[0011] According to one embodiment of the present invention, before determining the minimum judgment current based on the pre-fitted dry-run judgment current lower limit curve and the current feedback speed, the method further includes: acquiring multiple dry-run feedback speeds and corresponding cross-axis currents of the electric pump motor in dry-run operation; and performing curve fitting based on each dry-run feedback speed and corresponding cross-axis current to obtain the dry-run judgment current lower limit curve.

[0012] According to one embodiment of the present invention, curve fitting is performed based on each dry-run feedback speed and the corresponding quadrature-axis current to obtain a dry-run judgment current lower limit curve, including: dividing multiple dry-run feedback speeds into speed ranges to obtain multiple speed ranges; performing linear fitting on the dry-run feedback speed and the corresponding AC current of each speed range to obtain a fitting function curve corresponding to each speed range; and splicing the fitting function curves corresponding to each speed range to obtain the dry-run judgment current lower limit curve.

[0013] According to one embodiment of the present invention, linear fitting is performed on the dry-run feedback speed and the corresponding AC current for each speed range, including: fitting the dry-run feedback speed and the corresponding quadrature-axis current for each speed range using a linear function fitting method to obtain a linear function curve corresponding to each speed range; shifting the linear function curve corresponding to each speed range down by a predetermined margin to obtain a fitted function curve corresponding to each speed range.

[0014] According to one embodiment of the present invention, after stitching together the fitted function curves corresponding to each speed range, the method further includes: shifting the stitched function curves down by a predetermined margin in order to obtain the lower limit curve of the dry-run judgment current.

[0015] According to one embodiment of the present invention, determining the minimum judgment current based on a pre-fitted dry-run judgment current lower limit curve and the current feedback speed includes: finding the target speed range corresponding to the current feedback speed from multiple speed ranges, and determining the fitting function curve corresponding to the target speed range; determining the minimum judgment current corresponding to the current feedback speed based on the fitting function curve corresponding to the target speed range and the current feedback speed.

[0016] According to one embodiment of the present invention, determining whether an electric pump has experienced a dry running fault based on the relationship between the current quadrature axis current and the minimum determination current includes: determining that the electric pump has experienced a dry running fault when the current quadrature axis current is less than the minimum determination current for a predetermined duration.

[0017] To achieve the above objectives, a computer-readable storage medium is provided according to a second aspect of the present invention, having stored thereon a fault detection program for an electric pump, which, when executed by a processor, implements the fault detection method for an electric pump according to any of the foregoing embodiments.

[0018] According to the computer-readable storage medium of the present invention, by executing the computer program of the above-described electric pump fault detection method, by calculating the minimum judgment current corresponding to the current feedback speed and based on the relationship between the current quadrature shaft current and the minimum judgment current, it is possible to detect in a timely manner whether the electric pump is in a dry running state, thereby avoiding damage to the electric pump caused by the electric pump being in a dry running state for a long time.

[0019] To achieve the above objectives, an electric pump controller is provided according to a third aspect of the present invention, comprising: a memory, a processor, and an electric pump fault detection program stored in the memory and executable on the processor. When the processor executes the program, it implements the electric pump fault detection method of any of the foregoing embodiments.

[0020] According to the electric pump controller of the present invention, the computer program of the above-mentioned electric pump fault detection method is executed by the processor. By calculating the minimum judgment current corresponding to the current feedback speed and based on the relationship between the current quadrature shaft current and the minimum judgment current, the controller can detect in a timely manner whether the electric pump is in a dry running state, thereby avoiding damage to the electric pump caused by the electric pump being in a dry running state for a long time.

[0021] To achieve the above objectives, a fault detection device for an electric pump is provided according to a fourth aspect of the present invention, comprising: a first acquisition module for acquiring the current feedback speed of the electric pump motor; a second acquisition module for acquiring the current quadrature-axis current of the electric pump motor; a determination module for determining a minimum judgment current based on a pre-fitted dry-run judgment current lower limit curve and the current feedback speed; and a judgment module for determining whether the electric pump has experienced a dry-run fault based on the relationship between the current quadrature-axis current and the minimum judgment current.

[0022] According to an embodiment of the present invention, the electric pump fault detection device acquires the current feedback speed of the electric pump motor through a first acquisition module and the current quadrature-axis current through a second acquisition module. Then, a determination module determines a minimum judgment current based on a pre-fitted dry-run judgment current lower limit curve and the current feedback speed. Finally, a judgment module determines whether the electric pump has experienced a dry-run fault based on the relationship between the current quadrature-axis current and the minimum judgment current. Thus, by calculating the minimum judgment current corresponding to the current feedback speed (the minimum judgment current being the quadrature-axis current corresponding to the current feedback speed when the electric pump motor is in a dry-running state), and based on the relationship between the current quadrature-axis current and the minimum judgment current, it is possible to detect in a timely manner whether the electric pump is in a dry-running state, thereby preventing damage to the electric pump caused by prolonged dry-running.

[0023] To achieve the above objectives, an electronic oil pump is provided according to a fifth aspect embodiment of the present invention, including the aforementioned fault detection device for an electric pump.

[0024] According to the embodiment of the present invention, the electric oil pump, by employing the above-mentioned fault detection device for electric pumps, can promptly detect whether the electric pump is in a dry running state by calculating the minimum judgment current corresponding to the current feedback speed and based on the relationship between the current quadrature shaft current and the minimum judgment current, thereby avoiding damage to the electric pump caused by the electric pump being in a dry running state for a long time.

[0025] To achieve the above objectives, a vehicle comprising the aforementioned electronic oil pump is provided according to a sixth aspect embodiment of the present invention.

[0026] According to the vehicle of the present invention, by employing the above-described electronic oil pump, by calculating the minimum judgment current corresponding to the current feedback speed and based on the relationship between the current cross-axis current and the minimum judgment current, it is possible to detect in a timely manner whether the electric pump is in a dry running state, thereby avoiding damage to the electric pump caused by the electric pump being in a dry running state for a long time.

[0027] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0028] Figure 1 This is a flowchart illustrating a fault detection method for an electric pump according to an embodiment of the present invention.

[0029] Figure 2 This is a flowchart of obtaining the lower limit curve of the dry-run determination current according to an embodiment of the present invention;

[0030] Figure 3This is a flowchart of obtaining the lower limit curve of the dry-run determination current according to another embodiment of the present invention;

[0031] Figure 4 This is a flowchart illustrating the process of determining the minimum judgment current corresponding to the current feedback speed according to an embodiment of the present invention.

[0032] Figure 5 This is a flowchart illustrating a fault detection method for an electric pump according to another embodiment of the present invention;

[0033] Figure 6 It is a graph showing the actual operating curve, actual dry running curve, fitting function curve, and dry running judgment current lower limit curve of the oil pump at different temperatures according to an embodiment of the present invention.

[0034] Figure 7 This is a schematic diagram of the structure of an electric pump controller according to an embodiment of the present invention;

[0035] Figure 8 This is a schematic diagram of the structure of a fault detection device for an electric pump according to an embodiment of the present invention;

[0036] Figure 9 This is a schematic diagram of the structure of an electronic oil pump according to an embodiment of the present invention;

[0037] Figure 10 This is a structural schematic diagram of a vehicle according to an embodiment of the present invention. Detailed Implementation

[0038] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0039] The following description, with reference to the accompanying drawings, describes a fault detection method, apparatus, electric pump controller, electronic oil pump, vehicle, and storage medium for an electric pump according to embodiments of the present invention.

[0040] Figure 1 This is a schematic flowchart of a fault detection method for an electric pump according to a first embodiment of the present invention. Figure 1 As shown, the fault detection method for this electric pump includes the following steps:

[0041] S101, obtain the current feedback speed of the electric pump motor and the current quadrature shaft current of the electric pump motor.

[0042] It should be noted that the current feedback speed ω1 of the electric pump motor can be obtained by detecting the speed sensor, and the current quadrature-axis current i qf1 It can be obtained by collecting the three-phase current of the electric pump motor and then performing Clark and Park transformations on the three-phase current.

[0043] S102, determine the minimum judgment current based on the pre-fitted dry-run judgment current lower limit curve and the current feedback speed.

[0044] Specifically, the pre-fitted dry-run judgment current lower limit curve i qf2 (ω f1 ω is the dry-run feedback speed of the electric pump motor. f1 With dry rotation determination current i qf2 The curves between, from the dry-run current lower limit curve i qf2 (ω f1 The minimum decision current i corresponding to the current feedback speed ω1 can be obtained. qf2 (ω f1 (That is, the quadrature-axis current corresponding to the current feedback speed of the electric pump motor when it is running dry).

[0045] S103, based on the relationship between the current quadrature shaft current and the minimum judgment current, determine whether the electric pump has experienced a dry running fault.

[0046] In some embodiments, determining whether the electric pump has experienced a dry running fault based on the relationship between the current quadrature shaft current and the minimum determination current includes: determining that the electric pump has experienced a dry running fault when the current quadrature shaft current is less than the minimum determination current and continues for a predetermined duration.

[0047] Specifically, because the electric pump motor has no load when running dry, the quadrature-axis current it generates is relatively small. Therefore, if the current quadrature-axis current i qf1 Less than the minimum judgment current i qf2 (ω f1 If the current cross-axis current is low, it indicates that the electric pump motor is not under load, and therefore the electric pump is experiencing a dry-running fault; if the current cross-axis current is low, it indicates that the electric pump motor is not under load. qf1 Greater than or equal to the minimum judgment current i qf2 (ω f1 If the current is within the normal range, it indicates that the electric pump motor is under load, and therefore the electric pump is in normal operation. However, to avoid misjudgment, when the current quadrature-axis current i... qf1 Less than the minimum judgment current i qf2 (ω f1 And the electric pump is only confirmed to have a dry running fault after a predetermined duration Tc.

[0048] In the above embodiment, by calculating the minimum judgment current corresponding to the current feedback speed, the minimum judgment current is the quadrature shaft current corresponding to the current feedback speed when the electric pump motor is in dry running state. Based on the relationship between the current quadrature shaft current and the minimum judgment current, it is possible to detect in a timely manner whether the electric pump is in dry running state, thereby avoiding damage to the electric pump caused by the electric pump being in dry running state for a long time.

[0049] In some embodiments, such as Figure 2 As shown, before determining the minimum judgment current based on the pre-fitted dry-run judgment current lower limit curve and the current feedback speed, the method further includes:

[0050] S201, obtain multiple dry-run feedback speeds and corresponding quadrature-axis currents of the electric pump motor when it is in dry-run operation.

[0051] Specifically, the quadrature shaft current corresponding to the maximum feedback speed from 0 to the maximum feedback speed is obtained when the electric pump motor is running dry. In this way, the lower limit curve of the dry running judgment current obtained by subsequent fitting can obtain the minimum judgment current of the electric pump motor at all feedback speeds, thereby avoiding the situation where the minimum judgment current cannot be obtained when the current feedback speed is outside the speed range of the lower limit curve of the dry running judgment current.

[0052] S202, based on the dry-run feedback speed and the corresponding quadrature shaft current, curve fitting is performed to obtain the dry-run judgment current lower limit curve.

[0053] Specifically, the least squares method can be used, with each dry-run feedback speed as the independent variable and the corresponding quadrature-axis current as the dependent variable, to perform curve fitting and obtain the function curve between each dry-run feedback speed and the corresponding quadrature-axis current. This function curve is the lower limit curve for the dry-run judgment current.

[0054] In some embodiments, such as Figure 3 As shown, curve fitting is performed based on each dry-run feedback speed and the corresponding quadrature-axis current to obtain the lower limit curve of the dry-run judgment current, including:

[0055] S301 divides multiple dry-rotation feedback speeds into speed ranges to obtain multiple speed range segments.

[0056] Specifically, for the dry-rotor feedback speed ω f1 By dividing the interval, multiple velocity intervals [0, ω] are obtained. f10 ), [ω f10 ,ω f11 ), [ω f11 ,ω f12 ), …, [ω f1x ,ω f1max), where x = 0, 1, 2, ... . The speed range is defined based on the error between the fitted curve and the actual dry-running curve. For example, the electric pump motor in [0, ω f10 The error between the fitted curve and the actual dry-running curve is the first error. The electric pump motor operates in [0, ω]. f11 The error between the fitted curve and the actual dry-wheel curve is the second error. If the first error is less than the second error, the speed range is divided into [0, ω]. f10 If the first error is greater than or equal to the second error, the velocity range is divided into [0, ω]. f11 Compared to directly fitting a curve using multiple dry-run feedback speeds and corresponding quadrature-axis currents, this method yields a lower limit curve for the dry-run judgment current with smaller errors, thus avoiding the influence of curve fitting errors on the determination of dry-run faults. The number of speed range divisions can be adjusted based on the operating speed range of the electric pump motor.

[0057] S302 performs linear fitting on the dry-run feedback speed and the corresponding AC current for each speed range to obtain the fitting function curve for each speed range.

[0058] Specifically, the fitting method here can be the same as the method described above that directly performs curve fitting on each dry-engine feedback speed and the corresponding cross-axis current. Using the least squares method, and with the dry-engine feedback speed of each speed range as the independent variable and the corresponding cross-axis current as the dependent variable, a linear fit is performed to obtain the fitting function curve for each speed range. Compared to directly performing curve fitting on each dry-engine feedback speed and the corresponding cross-axis current, the fitting function curve obtained in this way has a smaller error.

[0059] In some embodiments, linear fitting is performed on the dry-run feedback speed and the corresponding AC current for each speed range, including: fitting the dry-run feedback speed and the corresponding quadrature-axis current for each speed range using a linear function fitting method to obtain a linear function curve corresponding to each speed range; shifting the linear function curve corresponding to each speed range down by a predetermined margin to obtain a fitted function curve corresponding to each speed range.

[0060] Specifically, the dry-rotation feedback speed ω for each speed range is... f1 and the corresponding quadrature-axis current i qf0 Substitute into the linear function i qf0 (ω f1 )=k*ω f1 In +b, the slope k and intercept b of the linear function for each velocity interval are obtained, thus yielding the linear function curve i. qf0 (ω f1 )=k0*ω f1 +b0. Considering the dry-wheel feedback speed ωf1 and the corresponding quadrature-axis current i qf0 There are inherent errors (such as performance differences in electric pump motors and errors during data acquisition), various interference factors in the curve fitting process, and the margin required during the operation of the electric pump motor. Therefore, it is necessary to retain a certain current margin and shift the linear function curve downward by a predetermined margin Δi. q , and Δi q <0, thus obtaining the fitted function curve i qf2 (ω f1 ) = i qf0 (ω f1 )+Δi q .

[0061] In this embodiment, considering the performance differences of the electric pump motor and the errors in data acquisition, the linear function curve is shifted down by a predetermined margin to obtain the fitted function curve, so the error of the fitted function curve is small.

[0062] S303 splices the fitted function curves corresponding to each speed range to obtain the lower limit curve of the dry running current.

[0063] Specifically, by connecting the fitting function curves corresponding to different speed ranges end to end, the lower limit curve of the dry running current is obtained.

[0064] In some embodiments, after stitching together the fitted function curves corresponding to each speed range, the method further includes: shifting the stitched function curves down by a predetermined margin to obtain the lower limit curve of the dry-run judgment current.

[0065] In other words, when linearly fitting the dry-run feedback speed and the corresponding AC current for each speed range, the function curve can be shifted down by a predetermined margin, or the function curve can be shifted down by a predetermined margin after splicing the fitted function curves, thereby obtaining the lower limit curve of the dry-run judgment current.

[0066] In this embodiment, by dividing multiple dry-run feedback speeds into different speed ranges, calculating the fitting function curves for each range, and shifting the fitting function curves down by a predetermined margin, the error between the dry-run judgment current lower limit curve and the actual dry-run curve is reduced, thereby further improving the accuracy of dry-run state detection.

[0067] In some embodiments, such as Figure 4 As shown, the minimum judgment current is determined based on the pre-fitted dry-run judgment current lower limit curve and the current feedback speed, including:

[0068] S401, find the target speed range corresponding to the current feedback speed from multiple speed ranges, and determine the fitting function curve corresponding to the target speed range.

[0069] Specifically, the speed range containing the current feedback rotational speed ω1 is found from multiple speed ranges, and this speed range is taken as the target speed range. The fitting function curve i corresponding to this range is then determined. qf2 (ω f1 )=k2*ω f1 +b2.

[0070] S402, based on the fitting function curve corresponding to the target speed range and the current feedback speed, determine the minimum judgment current corresponding to the current feedback speed.

[0071] Specifically, the current feedback rotational speed ω1 is substituted into the fitting function curve i corresponding to the target speed range. qf2 (ω f1 )=k2*ω f1 +b2, since k2 and b2 have already been fitted, the minimum decision current i can be obtained. qf2 (ω1).

[0072] For example, the current feedback speed ω1 of the electric pump motor is within the speed range [ω f10 ,ω f11 In the given information, the fitting function curve corresponding to this speed range is i. qf2 (ω f1 )=k2*ω f1 +b2, substitute the current feedback speed ω1 into the fitted function curve i qf2 (ω f1 )=k2*ω f1 +b2, the minimum decision current i can be obtained. qf2 (ω1).

[0073] In this embodiment, the minimum judgment current can be obtained by finding the speed range in which the current feedback speed is located and the fitting function curve corresponding to the speed range, and by substituting the current feedback speed into the fitting function curve.

[0074] The technical solution of this application will be further described in detail below with reference to specific implementation methods:

[0075] like Figure 5 As shown, the fault detection methods for electric pumps include:

[0076] S501, Obtain multiple dry-running feedback speeds ω of the electric pump motor during dry-running operation. f1 and the corresponding quadrature-axis current i qf0 .

[0077] S502, divides multiple dry-rotor feedback speeds into speed ranges, resulting in multiple speed ranges: [0, ω f10 ), [ω f10 ,ω f11), [ω f11 ,ω f12 ), …, [ω f1x ,ω f1max ), where x = 0, 1, 2, ...

[0078] S503, using a linear function i qf0 (ω f1 )=k*ω f1 +b provides feedback speed ω for dry rotation within each speed range. f1 and the corresponding quadrature-axis current i qf0 By performing fitting, the dry-rotation feedback speed ω for each speed range is obtained. f1 and the corresponding quadrature-axis current i qf0 The linear function curve i qf0 (ω f1 )=k0*ω f1 +b0.

[0079] S504, considering the required margin during the operation of the electric pump motor, as well as the error interference factors in the data calibration and curve fitting process, the linear function curve i corresponding to each speed range is... qf0 (ω f1 )=k0*ω f1 +b0 shifts down the predetermined margin Δi q To obtain the fitting function curve i corresponding to each speed range. qf2 (ω f1 ) = i qf0 (ω f1 )+Δi q And the fitting function curve i corresponding to each speed range qf2 (ω f1 ) = i qf0 (ω f1 )+Δi q By splicing the curves, we obtain the lower limit curve of the dry-running judgment current. qf2 (ω f1 ).

[0080] S505, obtain the current feedback speed ω1 and current quadrature-axis current i during the operation of the electric pump motor. qf1 And find the speed range in which the current feedback rotation speed ω1 is located (e.g., [ω f10 ,ω f11 And the linear function curve i corresponding to this speed range. qf2 (ω f1 )=k2*ω f1 +b2, using the linear function curve i qf2 (ω f1 )=k2*ω f1 +b2 calculates the minimum decision current iqf2 (ω1).

[0081] S506, Determine the current quadrature-axis current i qf1 Is it less than the minimum judgment current i? qf2 (ω1), if the current quadrature-axis current i qf1 Less than the minimum judgment current i qf2 (ω1), execute step S507, if the current quadrature-axis current i qf1 Greater than or equal to the minimum judgment current i qf2 (ω1), proceed to step S505.

[0082] S507, Determine the current quadrature-axis current i qf1 Less than the minimum judgment current i qf2 If the duration of (ω1) is greater than the predetermined duration Tc, proceed to step S508; if the duration is less than the predetermined duration Tc, proceed to step S505.

[0083] S508 indicates that the electric pump has experienced a dry running fault.

[0084] In this embodiment, by calculating the minimum judgment current corresponding to the current feedback speed and based on the relationship between the current quadrature shaft current and the minimum judgment current, it is possible to detect in a timely manner whether the electric pump is in a dry running state, thereby avoiding damage to the electric pump caused by prolonged dry running. Furthermore, when fitting the lower limit curve of the dry running judgment current, the process is divided into different speed ranges for linear fitting and the fitted function curve is shifted down by a predetermined margin, reducing the error between the lower limit curve of the dry running judgment current and the actual dry running curve, thereby further improving the accuracy of dry running state detection.

[0085] Furthermore, Figure 6 The graphs show the actual operating curves, actual dry-running curves, fitted function curves, and dry-running judgment current lower limit curves of the oil pump's feedback speed and cross-axis current at different temperatures. Figure 6 It can be seen that the cross-axis current of the oil pump at high oil temperature is less than that at low oil temperature. The cross-axis current of the oil pump at high oil temperature is closer to that of the oil pump in dry running condition. Therefore, as long as the cross-axis current of the oil pump at high oil temperature is greater than the minimum judgment current, the oil pump is in normal working condition. Furthermore, the fitting function curve obtained by the method of this embodiment has a small error with the actual dry running curve. At the same time, shifting the fitting function curve down by a predetermined margin can avoid interference caused by data acquisition errors, further improving the accuracy of the dry running condition detection results.

[0086] In summary, the electric pump fault detection method according to embodiments of the present invention first obtains the current feedback speed and current quadrature-axis current of the electric pump motor. Then, it determines the minimum judgment current using a pre-fitted dry-run judgment current lower limit curve and the current feedback speed. Finally, it determines whether the electric pump has experienced a dry-run fault based on the relationship between the current quadrature-axis current and the minimum judgment current. Therefore, by calculating the minimum judgment current corresponding to the current feedback speed (the minimum judgment current being the quadrature-axis current corresponding to the current feedback speed when the electric pump motor is in a dry-running state), and based on the relationship between the current quadrature-axis current and the minimum judgment current, it is possible to detect in a timely manner whether the electric pump is in a dry-running state, thereby preventing damage to the electric pump caused by prolonged dry-running.

[0087] Corresponding to the above embodiments, embodiments of the present invention also provide a computer-readable storage medium storing a fault detection program for an electric pump, which, when executed by a processor, implements the fault detection method for an electric pump of any of the foregoing embodiments.

[0088] According to the computer-readable storage medium of the present invention, by executing the computer program of the above-described electric pump fault detection method, by calculating the minimum judgment current corresponding to the current feedback speed and based on the relationship between the current quadrature shaft current and the minimum judgment current, it is possible to detect in a timely manner whether the electric pump is in a dry running state, thereby avoiding damage to the electric pump caused by the electric pump being in a dry running state for a long time.

[0089] Corresponding to the above embodiments, embodiments of the present invention also provide an electric pump controller. For example... Figure 7 As shown, the electric pump controller 600 includes: a memory 610, a processor 620, and an electric pump fault detection program stored in the memory 610 and executable on the processor 620. When the processor 620 executes the program, it implements the electric pump fault detection method of any of the foregoing embodiments.

[0090] According to the electric pump controller of the present invention, the computer program of the above-mentioned electric pump fault detection method is executed by the processor. By calculating the minimum judgment current corresponding to the current feedback speed and based on the relationship between the current quadrature shaft current and the minimum judgment current, the controller can detect in a timely manner whether the electric pump is in a dry running state, thereby avoiding damage to the electric pump caused by the electric pump being in a dry running state for a long time.

[0091] Corresponding to the above embodiments, embodiments of the present invention also provide a fault detection device for an electric pump. For example... Figure 8 As shown, the device includes: a first acquisition module 10, a second acquisition module 20, a determination module 30, and a judgment module 40.

[0092] The first acquisition module 10 is used to acquire the current feedback speed of the electric pump motor; the second acquisition module 20 is used to acquire the current quadrature shaft current of the electric pump motor; the determination module 30 is used to determine the minimum judgment current based on the pre-fitted dry running judgment current lower limit curve and the current feedback speed; and the judgment module 40 is used to determine whether the electric pump has a dry running fault based on the relationship between the current quadrature shaft current and the minimum judgment current.

[0093] In some embodiments, the apparatus further includes a fitting module (not shown), configured to: acquire multiple dry-run feedback speeds and corresponding cross-axis currents of the electric pump motor in dry-run operation state before determining the minimum judgment current based on the pre-fitted dry-run judgment current lower limit curve and the current feedback speed; and perform curve fitting based on each dry-run feedback speed and corresponding cross-axis current to obtain the dry-run judgment current lower limit curve.

[0094] In some embodiments, the fitting module is further configured to: divide the multiple dry-run feedback speeds into speed ranges to obtain multiple speed ranges; perform linear fitting on the dry-run feedback speed and the corresponding AC current of each speed range to obtain the fitting function curve corresponding to each speed range; and splice the fitting function curves corresponding to each speed range to obtain the dry-run judgment current lower limit curve.

[0095] In some embodiments, the fitting module is further configured to: fit the dry-running feedback speed and the corresponding quadrature-axis current of each speed range using a linear function fitting method to obtain a linear function curve corresponding to each speed range; and shift the linear function curve corresponding to each speed range down by a predetermined margin to obtain a fitted function curve corresponding to each speed range.

[0096] In some embodiments, the device further includes a downward shifting module (not shown) for shifting the spliced ​​function curves down by a predetermined margin after splicing the fitted function curves corresponding to each speed range, so as to obtain the dry-run judgment current lower limit curve.

[0097] In some embodiments, the determining module 30 is specifically used to: find the target speed range corresponding to the current feedback speed from multiple speed ranges, and determine the fitting function curve corresponding to the target speed range; and determine the minimum judgment current corresponding to the current feedback speed based on the fitting function curve corresponding to the target speed range and the current feedback speed.

[0098] In some embodiments, the determination module 40 is specifically used to: determine that the electric pump has a dry running fault when the current cross-axis current is less than the minimum determination current and continues for a predetermined time.

[0099] It should be noted that the specific implementation of the electric pump fault detection device in this embodiment of the invention corresponds one-to-one with the specific implementation of the electric pump fault detection method in the foregoing embodiments of the invention, and will not be repeated here.

[0100] According to an embodiment of the present invention, the electric pump fault detection device acquires the current feedback speed of the electric pump motor through a first acquisition module and the current quadrature-axis current through a second acquisition module. Then, a determination module determines a minimum judgment current based on a pre-fitted dry-run judgment current lower limit curve and the current feedback speed. Finally, a judgment module determines whether the electric pump has experienced a dry-run fault based on the relationship between the current quadrature-axis current and the minimum judgment current. Thus, by calculating the minimum judgment current corresponding to the current feedback speed (the minimum judgment current being the quadrature-axis current corresponding to the current feedback speed when the electric pump motor is in a dry-running state), and based on the relationship between the current quadrature-axis current and the minimum judgment current, it is possible to detect in a timely manner whether the electric pump is in a dry-running state, thereby preventing damage to the electric pump caused by prolonged dry-running.

[0101] Corresponding to the above embodiments, embodiments of the present invention also provide an electronic oil pump. For example... Figure 9 As shown, the electronic oil pump 800 includes the aforementioned electric pump fault detection device 700.

[0102] According to the embodiment of the present invention, the electric oil pump, by employing the above-mentioned fault detection device for electric pumps, can promptly detect whether the electric pump is in a dry running state by calculating the minimum judgment current corresponding to the current feedback speed and based on the relationship between the current quadrature shaft current and the minimum judgment current, thereby avoiding damage to the electric pump caused by the electric pump being in a dry running state for a long time.

[0103] Corresponding to the above embodiments, embodiments of the present invention also provide a vehicle. For example... Figure 10 As shown, vehicle 900 includes the aforementioned electronic oil pump 800.

[0104] The vehicle 900 according to an embodiment of the present invention includes the aforementioned electronic oil pump 800. Here, the vehicle 900 can be a new energy vehicle. In some embodiments, the new energy vehicle can be a pure electric vehicle with an electric motor as the main driving force; in other embodiments, the new energy vehicle can also be a hybrid vehicle with both an internal combustion engine and an electric motor as the main driving force. Regarding the internal combustion engine and electric motor mentioned in the above embodiments that provide driving power to the new energy vehicle, the internal combustion engine can use gasoline, diesel, hydrogen, etc., as fuel, and the method of providing electrical energy to the electric motor can use a power battery, hydrogen fuel cell, etc., without special limitation. It should be noted that this is merely an exemplary description of the structure of new energy vehicles, etc., and is not intended to limit the scope of protection of the present invention.

[0105] According to the vehicle of the present invention, by employing the above-described electronic oil pump, by calculating the minimum judgment current corresponding to the current feedback speed and based on the relationship between the current cross-axis current and the minimum judgment current, it is possible to detect in a timely manner whether the electric pump is in a dry running state, thereby avoiding damage to the electric pump caused by the electric pump being in a dry running state for a long time.

[0106] It should be noted that the logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Alternatively, the computer-readable medium may be paper or other suitable media on which the program can be printed, since the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.

[0107] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0108] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0109] Furthermore, the terms "first," "second," etc., used in the embodiments of this invention are for descriptive purposes only and should not be construed as indicating or implying relative importance, or implicitly specifying the number of technical features indicated in this embodiment. Therefore, features defined with terms such as "first" and "second" in the embodiments of this invention can explicitly or implicitly indicate that the embodiment includes at least one of those features. In the description of this invention, the word "multiple" means at least two or more, such as two, three, four, etc., unless otherwise explicitly specified in the embodiments.

[0110] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A fault detection method for an electric pump, characterized in that, include: Obtain the current feedback speed of the electric pump motor and the current quadrature-axis current of the electric pump motor; The minimum judgment current is determined based on the pre-fitted dry-run judgment current lower limit curve and the current feedback speed; Based on the relationship between the current quadrature current and the minimum determination current, determine whether the electric pump has experienced a dry running fault; Before determining the minimum judgment current based on the pre-fitted dry-run judgment current lower limit curve and the current feedback speed, the method further includes: Obtain multiple dry-run feedback speeds and corresponding quadrature-axis currents of the electric pump motor during dry-run operation; Based on the dry-run feedback speed and the corresponding cross-axis current, curve fitting is performed to obtain the lower limit curve of the dry-run judgment current; Based on curve fitting of each dry-run feedback speed and the corresponding quadrature-axis current, the lower limit curve of the dry-run judgment current is obtained, including: The multiple dry-rotation feedback speeds are divided into speed ranges to obtain multiple speed range segments; Linear fitting is performed on the dry-run feedback speed and the corresponding AC current for each speed range to obtain the fitting function curve for each speed range. The fitted function curves corresponding to each speed range are spliced ​​together to obtain the lower limit curve of the dry running current; The minimum judgment current is determined based on the pre-fitted dry-run judgment current lower limit curve and the current feedback speed, including: Find the target speed range corresponding to the current feedback rotation speed from the multiple speed ranges, and determine the fitting function curve corresponding to the target speed range; Based on the fitted function curve corresponding to the target speed range and the current feedback speed, determine the minimum judgment current corresponding to the current feedback speed.

2. The method according to claim 1, characterized in that, Linear fitting is performed on the dry-run feedback speed and corresponding AC current for each speed range, including: The dry-run feedback speed and the corresponding quadrature-axis current of each speed range are fitted using a linear function fitting method to obtain the linear function curve corresponding to each speed range. The linear function curve corresponding to each speed range is shifted down by a predetermined margin to obtain the fitted function curve corresponding to each speed range.

3. The method according to claim 1, characterized in that, After stitching together the fitted function curves corresponding to each velocity range, the method further includes: The spliced ​​function curve is shifted down by a predetermined margin to obtain the lower limit curve of the dry-run judgment current.

4. The method according to any one of claims 1-3, characterized in that, Based on the relationship between the current quadrature-axis current and the minimum determination current, determine whether the electric pump has experienced a dry-running fault, including: When the current cross-axis current is less than the minimum determination current and continues for a predetermined duration, it is determined that the electric pump has experienced a dry running fault.

5. A computer-readable storage medium, characterized in that, It stores a fault detection program for an electric pump, which, when executed by a processor, implements the fault detection method for an electric pump according to any one of claims 1-4.

6. An electric pump controller, characterized in that, include: A memory, a processor, and a fault detection program for an electric pump stored in the memory and executable on the processor, wherein when the processor executes the program, it implements the fault detection method for the electric pump according to any one of claims 1-4.

7. A fault detection device for an electric pump, characterized in that, include: The first acquisition module is used to acquire the current feedback speed of the electric pump motor; The second acquisition module is used to acquire the current quadrature-axis current of the electric pump motor; The determination module is used to determine the minimum determination current based on the pre-fitted dry-run determination current lower limit curve and the current feedback speed; The judgment module is used to determine whether the electric pump has experienced a dry running fault based on the relationship between the current quadrature axis current and the minimum judgment current; Before determining the minimum judgment current based on the pre-fitted dry-run judgment current lower limit curve and the current feedback speed, the process also includes: Obtain multiple dry-run feedback speeds and corresponding quadrature-axis currents of the electric pump motor during dry-run operation; Based on the dry-run feedback speed and the corresponding cross-axis current, curve fitting is performed to obtain the lower limit curve of the dry-run judgment current; Based on curve fitting of each dry-run feedback speed and the corresponding quadrature-axis current, the lower limit curve of the dry-run judgment current is obtained, including: The multiple dry-rotation feedback speeds are divided into speed ranges to obtain multiple speed range segments; Linear fitting is performed on the dry-run feedback speed and the corresponding AC current for each speed range to obtain the fitting function curve for each speed range. The fitted function curves corresponding to each speed range are spliced ​​together to obtain the lower limit curve of the dry running current; The minimum judgment current is determined based on the pre-fitted dry-run judgment current lower limit curve and the current feedback speed, including: Find the target speed range corresponding to the current feedback rotation speed from the multiple speed ranges, and determine the fitting function curve corresponding to the target speed range; Based on the fitted function curve corresponding to the target speed range and the current feedback speed, determine the minimum judgment current corresponding to the current feedback speed.

8. An electronic oil pump, characterized in that, Includes the fault detection device for the electric pump according to claim 7.

9. A vehicle, characterized in that, Including the electronic oil pump according to claim 8.

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