Method for estimating oil temperature of oil-cooled motor by using electronic oil pump
By acquiring and processing the speed and torque current signals of the electronic oil pump and calculating and correcting the oil temperature, the problem of increasing cost and complexity of traditional oil temperature sensors is solved, and faster and more economical oil temperature monitoring is achieved.
Patent Information
- Application Number
- CN202411344187.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-25
- Publication Date
- 2025-02-18
AI Technical Summary
In the prior art, the traditional way of obtaining motor oil temperature requires adding oil temperature sensors, which leads to an increase in system cost and complexity, and the sensor layout is limited, which cannot effectively reflect the oil temperature changes in the entire oil circuit.
By obtaining the speed signal and torque current signal of the electronic oil pump, the sliding average filtering process is performed, the oil temperature is calculated and corrected, and finally the filtering process is performed to output the estimated oil temperature.
Without a temperature sensor, the oil temperature can be calculated and the oil temperature changes in the entire oil circuit can be quickly reflected, saving space for laying out the sensors, reducing economic costs, and optimizing the overall structural layout.
Smart Images
Figure CN119469470A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of oil-cooling motor control, and in particular to a method for estimating the oil temperature of an oil-cooling motor by utilizing an electronic oil pump. Background Art
[0002] The motor oil temperature signal is crucial to motor control technology. The traditional way to obtain the motor oil temperature is to add an oil temperature sensor to directly collect the oil temperature at a certain point and provide it to the motor for algorithm processing. Although the addition of the oil temperature sensor increases the flexibility and stability of the oil circulation system control. However, the additional oil temperature sensor also increases the system cost and system complexity. The failure and signal distortion of the oil temperature sensor itself will also have a negative impact on the system protection. However, there is currently no simpler and lower-cost oil temperature detection solution in the industry. The layout of the oil temperature sensor is limited by space and has certain limitations. In addition, the oil temperature sensor can only represent the oil temperature at a local location, and the average oil temperature of the system as a whole often still has a certain deviation from the oil temperature at the oil temperature sensor location. Moreover, with the continuous development of new energy vehicle drive motor technology and increasingly fierce market competition, new requirements have been put forward for the cost of motor control and the overall structural layout. Summary of the invention
[0003] The purpose of the present invention is to address the corresponding deficiencies of the prior art and provide a method for estimating the oil temperature of an oil-cooled motor using an electronic oil pump, so as to achieve the purpose of optimizing the overall structural layout, improving the oil temperature accuracy and reducing the economic cost.
[0004] The technical solutions to the above problems are as follows:
[0005] A method for estimating the oil temperature of an oil-cooled motor using an electronic oil pump, characterized by comprising the following steps:
[0006] S1: Signal acquisition: obtain the electronic oil pump speed signal and the electronic oil pump torque current signal;
[0007] S2: Electronic oil pump speed filtering: performing sliding mean filtering on the acquired electronic oil pump speed;
[0008] S3: electronic oil pump torque current filtering: performing sliding mean filtering on the acquired electronic oil pump torque current;
[0009] S4: Oil temperature calculation: Calculate the oil temperature based on the electronic oil pump speed and torque current after filtering by S2 and S3;
[0010] S5: Oil temperature correction: Correct the oil temperature calculated in S4;
[0011] S6: Oil temperature filtering: filtering the oil temperature corrected in S5;
[0012] S7: Output oil temperature: Output the oil temperature after filtering in S6.
[0013] Furthermore, in S2, the steps of sliding mean filtering the electronic oil pump speed are as follows:
[0014] S21, setting the sliding window size: setting the sliding window size according to the number of electronic oil pump speed data points;
[0015] S22, initializing the sliding window: before starting the filtering process, the sliding window is initialized to obtain a buffer with a length equal to the window size, which is used to store the data points in the window;
[0016] S23, data processing: gradually obtain new electronic oil pump speed data points from the input data stream and add them to the window buffer. When the buffer is full, delete the oldest data point to free up window space.
[0017] S24, calculating the average value: after each adding of a new electronic oil pump speed data point, calculating the average value of all electronic oil pump speed data points in the buffer zone;
[0018] S25, output average value: use the calculated average value as the numerical output after the input data is filtered. Further, in S3, the steps of sliding mean filtering of the torque current of the electronic oil pump are as follows:
[0019] S31, setting the sliding window size: setting the sliding window size according to the number of electronic oil pump torque current data points;
[0020] S32, initializing the sliding window: before starting the filtering process, initializing the sliding window to obtain a buffer with a length equal to the window size, which is used to store the torque and current data points of the electronic oil pump in the window;
[0021] S33, data processing: gradually acquiring new electronic oil pump torque and current data points from the input data stream, and adding them to the window buffer. When the buffer is full, deleting the oldest data point to free up window space.
[0022] S34, calculating the average value: after each adding of a new electronic oil pump torque current data point, calculating the average value of all electronic oil pump torque current data points in the buffer;
[0023] S35, output average value: use the calculated average value of the electronic oil pump torque current as the input filtered data output.
[0024] Furthermore, in S4, the steps of calculating the oil temperature are as follows:
[0025] S41, obtaining the torque current of the electronic oil pump at different speeds at different temperatures;
[0026] S42, according to the difference in oil pump motor load current at different oil temperatures, calibrate the relationship between the oil temperature and the electronic oil pump speed and torque current, and generate an oil temperature database;
[0027] S43, using the electronic oil pump speed and torque current after filtering in S2 and S3 to search the oil temperature value from the oil temperature database.
[0028] Furthermore, in S5, the method for correcting the oil temperature is:
[0029] S51, correcting the oil temperature calculated in S4 according to the speed of the electronic oil pump;
[0030] S52, correcting the oil temperature calculated in S4 according to the torque current of the electronic oil pump;
[0031] S53: Calculate the corrected estimated oil temperature value.
[0032] Furthermore, in S6, the method for oil temperature sliding mean filtering processing comprises the following steps:
[0033] S61, setting the sliding window size: setting the sliding window size according to the number of corrected oil temperature data points in S5;
[0034] S62, initializing the sliding window: before starting the filtering process, the sliding window is initialized to obtain a buffer with a length equal to the window size, which is used to store the oil temperature data points in the window;
[0035] S63, data processing: gradually obtain new oil temperature data points from the input oil temperature data stream, and add them to the window buffer. When the buffer is full, delete the oldest data point to free up window space.
[0036] S64, calculating the average value: after each addition of a new oil temperature data point, calculating the average value of all oil temperature data points in the buffer zone;
[0037] S65, output average value: use the calculated oil temperature average value as the filtered data output.
[0038] The beneficial technical effects of the present invention are:
[0039] The present invention can calculate the oil temperature without a temperature sensor, and the oil temperature estimated by this method can directly reflect the oil temperature change of the entire oil circuit, and can reflect the change of oil temperature faster than the temperature collected by the sensor at a certain point. The invention saves space for arranging sensors, optimizes the overall structural layout, reduces economic costs, and improves the response time of the temperature change of the entire oil circuit. BRIEF DESCRIPTION OF THE DRAWINGS
[0040] Figure 1It is a flow chart of the present invention. DETAILED DESCRIPTION
[0041] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.
[0042] like Figure 1 As shown, a method for estimating the oil temperature of an oil-cooled motor using an electronic oil pump of the present invention comprises the following steps:
[0043] S1: Signal acquisition: obtain the electronic oil pump speed signal and the electronic oil pump torque current signal.
[0044] S2: Electronic oil pump speed filtering: Perform sliding mean filtering on the acquired electronic oil pump speed.
[0045] In S2, the steps of sliding mean filtering of the electronic oil pump speed are as follows:
[0046] S21. Setting the sliding window size: setting the sliding window size to N according to the number of electronic oil pump speed data points.
[0047] S22, initializing the sliding window: before starting the filtering process, the sliding window is initialized to obtain a buffer with a length equal to the window size, which is used to store the data points in the window.
[0048] S23, data processing: gradually obtain new electronic oil pump speed data points from the input data stream and add them to the window buffer. When the buffer is full, delete the oldest data point to free up window space.
[0049] The buffer data storage diagram is shown in the following table:
[0050] Electronic oil pump speed data points X1 X2 X3 X4 ...
[0051] S24, calculating the average value: after each adding of a new electronic oil pump speed data point, the average value of all electronic oil pump speed data points in the buffer is calculated, and the calculation formula is as follows:
[0052] SpdAvg=(X1+X2+X3+X4+……) / N
[0053] SpdAvg represents the average speed of the electronic oil pump after filtering.
[0054] S25, output average value: use the calculated average value as the numerical output after the input data is filtered.
[0055] S3: Electronic oil pump torque current filtering: Perform sliding mean filtering on the acquired electronic oil pump torque current. In S3, the steps of performing sliding mean filtering on the electronic oil pump torque current are as follows:
[0056] S31, setting the sliding window size: setting the sliding window size to L according to the number of electronic oil pump torque current data points.
[0057] S32, initializing the sliding window: before starting the filtering process, the sliding window is initialized to obtain a buffer with a length equal to the window size, which is used to store the torque and current data points of the electronic oil pump within the window.
[0058] S33, data processing: gradually obtain new electronic oil pump torque and current data points from the input data stream and add them to the window buffer. When the buffer is full, delete the oldest data point to free up window space.
[0059] The buffer data storage diagram is shown in the following table:
[0060] Electronic oil pump torque current data points Y1 Y2 Y3 Y4 ...
[0061] S34, calculate the average value: after adding a new electronic oil pump torque current data point each time, calculate the average value of all electronic oil pump torque current data points in the buffer. The calculation formula is as follows:
[0062] IqAvg=(Y1+Y2+Y3+Y4+……) / L
[0063] IqAvg represents the average value of the electronic oil pump torque current after filtering.
[0064] S35, output average value: use the calculated average value of the electronic oil pump torque current as the numerical output after input data filtering.
[0065] S4: Oil temperature calculation: Calculate the oil temperature based on the electronic oil pump speed and torque current after filtering in S2 and S3; in S4, the steps of oil temperature calculation are as follows:
[0066] S41, obtaining the torque current of the electronic oil pump at different speeds at different temperatures.
[0067] S42. According to the difference in oil pump motor load current at different oil temperatures, the relationship between the oil temperature and the electronic oil pump speed and torque current is calibrated to generate an oil temperature database.
[0068] The oil temperature database is shown in the following table:
[0069]
[0070] The above table is for reference only. In actual practice, the electronic oil pump torque current breakpoints and speed breakpoints can be added or deleted, and then the corresponding temperature values can be added or deleted.
[0071] S43, using the electronic oil pump speed and torque current after filtering in S2 and S3, searching the corresponding oil temperature value from the oil temperature database, and recording it as T0.
[0072] S5: Oil temperature correction: Correct the oil temperature calculated in S4; in this step, the method of oil temperature correction is:
[0073] S51. Correct the oil temperature calculated in S4 according to the speed of the electronic oil pump.
[0074] The electronic oil pump speed correction estimated oil temperature is shown in the following table:
[0075] Electronic oil pump speed S1 S2 S3 S4 ... Corrected temperature T1 TS1 TS2 TS3 TS4 ...
[0076] The above table is for reference only. In actual practice, the electronic oil pump speed breakpoints can be increased or decreased, and then the corresponding correction temperature T1 breakpoints can be increased or decreased.
[0077] S52, correcting the oil temperature calculated in S4 according to the torque current of the electronic oil pump.
[0078] The electronic oil pump torque current correction estimated oil temperature is shown as follows:
[0079] Electronic oil pump torque current I1 I2 I3 I4 ... Corrected temperature T2 TI1 TI2 TI3 TI4 ...
[0080] This table is for reference only. In actual practice, the electronic oil pump torque current breakpoints can be increased or decreased, and then the corresponding correction temperature T2 breakpoints can be increased or decreased.
[0081] S53, calculating the corrected estimated oil temperature value, the calculation formula is:
[0082] T=T0+T1+T2
[0083] Among them, T is the corrected oil temperature value.
[0084] T0 is the oil temperature value found from the oil temperature database based on the electronic oil pump speed and the electronic oil pump torque current.
[0085] T1 is the oil temperature value corrected according to the speed of the electronic oil pump.
[0086] T2 is the oil temperature value corrected according to the torque current of the electronic oil pump.
[0087] S6: Oil temperature filtering: Filter the oil temperature corrected in S5. In this step, the method of oil temperature sliding mean filtering is as follows:
[0088] S61, setting the sliding window size: setting the sliding window size to M according to the number of electronic pump speed data points.
[0089] S62, initializing the sliding window: before starting the filtering process, the sliding window is initialized to obtain a buffer with a length equal to the window size, which is used to store the data points in the window.
[0090] S63, data processing: gradually obtain new oil temperature data points from the input data stream and add them to the window oil temperature buffer. When the buffer is full, delete the oldest data point to free up window space.
[0091] The buffer data storage is shown in the following table:
[0092] Oil Temperature Data Points Temp1 Temp2 Temp3 Temp4 ...
[0093] This table is for reference only. In actual practice, oil temperature data points are added or deleted according to the size of the set sliding window.
[0094] S64, calculate the average value: after each new data point is added, calculate the average value of all data points in the buffer. The calculation formula is as follows:
[0095] OilTempAvg=(Temp1+Temp2+Temp3+Temp4+……) / M
[0096] OilTempAvg indicates the average oil temperature after filtering.
[0097] S65, output average value: use the calculated average value as the numerical output after the input data is filtered.
[0098] S7: Output oil temperature: Output the oil temperature after filtering in S6, that is, the calculated average oil temperature OilTempAvg is used as the filtered data output;
[0099] The above embodiments are part of the embodiments of the present invention. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but cannot be simply understood as limiting the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.
Claims
1. A method for estimating the oil temperature of an oil-cooled motor using an electronic oil pump, characterized in that The following steps are involved: S1: Signal acquisition: obtain the electronic oil pump speed signal and the electronic oil pump torque current signal; S2: Electronic oil pump speed filtering: performing sliding mean filtering on the acquired electronic oil pump speed; S3: electronic oil pump torque current filtering: performing sliding mean filtering on the acquired electronic oil pump torque current; S4: Oil temperature calculation: Calculate the oil temperature based on the electronic oil pump speed and torque current after filtering by S2 and S3; S5: Oil temperature correction: Correct the oil temperature calculated in S4; S6: Oil temperature filtering: filtering the oil temperature corrected in S5; S7: Output oil temperature: Output the oil temperature after filtering in S6.
2. The method for estimating the oil temperature of an oil-cooled motor using an electronic oil pump according to claim 1, characterized in that: In S2, the steps of sliding mean filtering of the electronic oil pump speed are as follows: S21, setting the sliding window size: setting the sliding window size according to the number of electronic oil pump speed data points; S22, initializing the sliding window: before starting the filtering process, the sliding window is initialized to obtain a buffer with a length equal to the window size, which is used to store the data points in the window; S23, data processing: gradually obtain new electronic oil pump speed data points from the input data stream and add them to the window buffer. When the buffer is full, delete the oldest data point to free up window space. S24, calculating the average value: after each adding of a new electronic oil pump speed data point, calculating the average value of all electronic oil pump speed data points in the buffer zone; S25, output average value: use the calculated average value as the numerical output after the input data is filtered.
3. The method for estimating the oil temperature of an oil-cooled motor using an electronic oil pump according to claim 1, characterized in that: In S3, the steps of sliding mean filtering of the electronic oil pump torque current are as follows: S31, setting the sliding window size: setting the sliding window size according to the number of electronic oil pump torque current data points; S32, initializing the sliding window: before starting the filtering process, initializing the sliding window to obtain a buffer with a length equal to the window size, which is used to store the torque and current data points of the electronic oil pump in the window; S33, data processing: gradually acquiring new electronic oil pump torque and current data points from the input data stream, and adding them to the window buffer. When the buffer is full, deleting the oldest data point to free up window space. S34, calculating the average value: after each adding of a new electronic oil pump torque current data point, calculating the average value of all electronic oil pump torque current data points in the buffer; S35, output average value: use the calculated average value of the electronic oil pump torque current as the input filtered data output.
4. The method for estimating the oil temperature of an oil-cooled motor using an electronic oil pump according to claim 1, characterized in that: In S4, the steps for calculating the oil temperature are as follows: S41, obtaining the torque current of the electronic oil pump at different speeds at different temperatures; S42, according to the difference in oil pump motor load current at different oil temperatures, calibrate the relationship between the oil temperature and the electronic oil pump speed and torque current, and generate an oil temperature database; S43, using the electronic oil pump speed and torque current after filtering in S2 and S3 to search the oil temperature value from the oil temperature database.
5. The method for estimating the oil temperature of an oil-cooled motor using an electronic oil pump according to claim 1, characterized in that: In S5, the method of oil temperature correction is: S51, correcting the oil temperature calculated in S4 according to the speed of the electronic oil pump; S52, correcting the oil temperature calculated in S4 according to the torque current of the electronic oil pump; S53: Calculate the corrected estimated oil temperature value.
6. The method for estimating the oil temperature of an oil-cooled motor using an electronic oil pump according to claim 1, characterized in that: In S6, the method for oil temperature sliding mean filtering processing comprises the following steps: S61, setting the sliding window size: setting the sliding window size according to the number of corrected oil temperature data points in S5; S62, initializing the sliding window: before starting the filtering process, the sliding window is initialized to obtain a buffer with a length equal to the window size, which is used to store the oil temperature data points in the window; S63, data processing: gradually obtain new oil temperature data points from the input oil temperature data stream, and add them to the window buffer. When the buffer is full, delete the oldest data point to free up window space. S64, calculating the average value: after each addition of a new oil temperature data point, calculating the average value of all oil temperature data points in the buffer zone; S65, output average value: use the calculated oil temperature average value as the filtered data output.
Citation Information
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