Electric drive assembly efficiency test method

Abstract

The invention discloses an electric drive assembly efficiency test method. The method comprises the following steps: correspondingly loading a test sample to a test bench; an efficiency test working condition point is set, different torques are tested at the same rotating speed, the absolute values of the torques are from small to large, unloading is conducted firstly after loading, then new torques are loaded, and the efficiency test working condition point is shown in the specification; limiting test boundaries, wherein the test boundaries at least comprise bus voltage, torque rise time, torque rise stabilization time and test time of each torque point; a test bench voltage and current sensor sets efficiency test working condition points, tests are carried out from large to small, and jump test cannot be carried out during the test; recording power generation working condition data of each management and control point; and the friction torque limit value data and the drag torque limit data of the test bench are used to form an electric drive assembly efficiency measurement program with a unified test boundary.

Description

Technical Field

[0001] The present invention relates to testing technology, and in particular to new energy vehicle testing, and specifically to an electric drive assembly efficiency testing method. Background Art

[0002] With the continuous development of the country's new energy industry, the market share of new energy vehicles continues to increase, and performance assurance testing of new energy vehicles also needs to be put on the agenda.

[0003] The electric drive assembly is an important component of new energy vehicles. It connects to the battery assembly and drives the wheels, display screens and other components of the new energy vehicle.

[0004] The efficiency of the electric drive assembly is directly related to the performance of new energy vehicles.

[0005] Therefore, efficiency testing of electric drive assemblies is essential to ensuring the factory quality of new energy vehicles.

[0006] Therefore, it is necessary to provide an electric drive assembly efficiency testing method to solve the above problems. Summary of the invention

[0007] The purpose of the present invention is to provide a method for testing the efficiency of an electric drive assembly.

[0008] The present invention achieves the above object through the following technical solutions:

[0009] A method for testing the efficiency of an electric drive assembly, comprising the following steps:

[0010] 1) Load the test samples onto the test bench;

[0011] 2) The friction torque limit of the test bench itself:

[0012] The test bench speed is increased at a rate of 600 rpm for no less than 3 seconds, and then enters the friction measurement stage for no less than 10 seconds. The friction measurement stage time is averaged, and no less than 10 working points are recorded. The original data of each working point is recorded as multiple lines of data and the average data of a single line of data. The average value of the torque reading is the bench friction torque at the speed, and is recorded as the test bench's own friction torque limit value data.

[0013] 3) Drag torque limitation:

[0014] After the test sample is loaded onto the test bench, it is towed by the test bench when not in operation to test and obtain the drag torque limit data;

[0015] 4) Electric drive assembly efficiency test:

[0016] 4-1) Set the efficiency test operating point: measure different torques at the same speed, the absolute value of the torque increases from small to large, unload after loading and then load the new torque, the efficiency test operating point is; the torque rise time is not less than 2s, the torque rise stabilization time is not less than 3s, and the effective test time is not less than 5s, and the time is evenly divided to take the value at several intervals;

[0017] 4-2) Define the test boundaries: at least including bus voltage, torque rise time, torque rise stabilization time, and test time for each torque point;

[0018] 4-3) Set the efficiency test operating point for the voltage and current sensors on the test bench, and test from high to low. Do not skip the test during the test.

[0019] 4-4) Record the power generation condition data of each control point;

[0020] 5) Using the test bench’s own friction torque limit value data and drag torque limit data, a program for determining the efficiency of the electric drive assembly with a unified test boundary is formed.

[0021] Furthermore, the test sample needs to be subjected to the test of the friction torque of the test stand itself before installation and after removal of the test stand; step 2) also includes:

[0022] 2-1) Confirm that the half-axle hub bearing or spline flange is disconnected from the bench connection flange;

[0023] 2-2) The test bench is disabled and the torque / speed sensor is zeroed.

[0024] Further, in step 2-2), when the torque / speed sensor cannot be adjusted to zero, the corresponding reading is recorded.

[0025] Furthermore, each time the test bench friction torque is tested, three sets of data need to be measured repeatedly. After each set of measurements, the bench dynamometer needs to be reversed to a speed of 500 r / s for a period of no less than 30 s.

[0026] Further, step 3) includes:

[0027] 3-1) Record at least the half-shaft A speed, half-shaft B speed, half-shaft A torque, half-shaft B torque, and total torque at the wheel end speeds of 0 rpm, 10 rpm, 25 rpm, 50 rpm, and 100 rpm;

[0028] 3-2) The test sample enters the standby mode at low voltage and then enters the high voltage state of not less than 730V;

[0029] 3-3) The test bench is accelerated at a speed not higher than 20r / S for 5-8s;

[0030] 3-4) Set no less than 3 intervals and record the drag loss value;

[0031] 3-5) Perform drag loss measurements at least three times, and when the deviation is no more than 10%, obtain the drag torque data using the average value.

[0032] Furthermore, the electric drive and dynamometer under test are both in standby mode, and the torque sensor reading is not 0. It is necessary to record the torque zero drift once before and after the efficiency and drag tests.

[0033] Furthermore, during the test, the oil temperature needs to be maintained at 65°C-85°C, the oil cooling system is circulated, and the preheating condition is set to 500rpm, 150N.

[0034] Furthermore, step 5) requires material quantity recording, which at least includes the specified motor torque, the specified left / right half-shaft speed, the specified left / right half-shaft torque, the actual left / right half-shaft speed, and the actual left / right half-shaft torque.

[0035] Compared with the prior art, the present invention ensures the consistency of test boundaries by uniformly defining test conditions and test working conditions, and eliminates the possibility that the accuracy of efficiency testing is affected by external interference, thereby causing inconsistent sample efficiency results. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic table for recording the data of the friction torque limit value of the test bench itself.

[0037] Figure 2 It is a schematic table of drag torque limit data recording.

[0038] Figure 3 It is a schematic diagram of the operating point setting principle.

[0039] Figure 4 It is a test boundary diagram.

[0040] Figure 5 It is a table of test condition points.

[0041] Figure 6 It is a table of power generation condition data. DETAILED DESCRIPTION

[0042] Example:

[0043] This embodiment is a method for testing the efficiency of an electric drive assembly, and the steps include:

[0044] 1) Load the test samples onto the test bench;

[0045] 2) The friction torque limit of the test bench itself:

[0046] The test bench speed is increased at a rate of 600 rpm for no less than 3 seconds, and then enters the friction measurement stage for no less than 10 seconds. The friction measurement stage time is averaged and no less than 10 working points are recorded. The original data of each working point, multiple rows of data and the average data of a single row of data, the average value of the torque reading, is recorded as the bench friction torque at the speed, and is recorded as the test bench's own friction torque limit value data. The data table can be referred to Figure 1 ;

[0047] 3) Drag torque limitation:

[0048] After the test sample is loaded onto the test bench, it is towed by the test bench when not working, and the drag torque limit data is tested and obtained. The record table is referenced Figure 2 ;

[0049] 4) Electric drive assembly efficiency test:

[0050] 4-1) Set the efficiency test operating point: measure different torques at the same speed, the absolute value of the torque increases from small to large, unload after loading and then load the new torque. The efficiency test operating point is: the torque rise time is not less than 2s, the torque rise stabilization time is not less than 3s, and the effective test time is not less than 5s. The time is divided into several intervals to take the value. You can refer to Figure 3 Schematic diagram of the operating point setting principle;

[0051] 4-2) Define the test boundaries: at least include bus voltage, torque rise time, torque rise stabilization time, and test time for each torque point. Figure 4 Schematic diagram of test boundaries;

[0052] 4-3) Test bench voltage and current sensors set efficiency test conditions, test from high to low, do not skip during test, refer to Figure 5 Table of test conditions;

[0053] 4-4) Record the power generation data at each operating point, refer to Figure 6 The power generation condition data table;

[0054] 5) Using the test bench’s own friction torque limit value data and drag torque limit data, a program for determining the efficiency of the electric drive assembly with a unified test boundary is formed.

[0055] The test sample needs to be tested for the friction torque of the test stand itself before installation and after removal of the test stand; step 2) also includes:

[0056] 2-1) Confirm that the half-axle hub bearing or spline flange is disconnected from the bench connection flange;

[0057] 2-2) The test bench is disabled and the torque / speed sensor is zeroed.

[0058] In step 2-2), when the torque / speed sensor cannot be adjusted to zero, record the corresponding reading.

[0059] Each time the bench friction torque is tested, three sets of data need to be measured repeatedly. After each set of measurements, the bench dynamometer needs to be reversed to a speed of 500r / s for no less than 30s.

[0060] Step 3) includes:

[0061] 3-1) Record at least the half-shaft A speed, half-shaft B speed, half-shaft A torque, half-shaft B torque, and total torque at the wheel end speeds of 0 rpm, 10 rpm, 25 rpm, 50 rpm, and 100 rpm;

[0062] 3-2) The test sample enters the standby mode at low voltage and then enters the high voltage state of not less than 730V;

[0063] 3-3) The test bench is accelerated at a speed not higher than 20r / S for 5-8s;

[0064] 3-4) Set no less than 3 intervals and record the drag loss value;

[0065] 3-5) Perform drag loss measurements at least three times, and when the deviation is no more than 10%, obtain the drag torque data using the average value.

[0066] The electric drive and dynamometer under test are both in standby mode, and the torque sensor reading is not 0. It is necessary to record the torque zero drift once before and after the efficiency and drag tests.

[0067] During the test, the oil temperature must be maintained at 65℃-85℃, the oil cooling system must be circulated, and the preheating condition must be set to 500rpm, 150N.

[0068] Step 5) requires material quantity recording, which at least includes the specified motor torque, the specified left / right half-shaft speed, the specified left / right half-shaft torque, the actual left / right half-shaft speed, and the actual left / right half-shaft torque.

[0069] Compared with the prior art, the present invention uniformly defines the test conditions and test working conditions to ensure the consistency of the test boundaries and eliminate the inconsistency of sample efficiency caused by external interference affecting the accuracy of the efficiency test.

[0070] The above are only some embodiments of the present invention. For those skilled in the art, several modifications and improvements can be made without departing from the creative concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A method for testing the efficiency of an electric drive assembly, characterized in that: include: 1) Load the test samples onto the test bench; 2) The friction torque limit of the test bench itself: The test bench speed is increased at a rate of 600 rpm for no less than 3 seconds, and then enters the friction measurement stage for no less than 10 seconds. The friction measurement stage time is averaged and no less than 10 working condition points are recorded; Record the original data of each working point, multiple lines of data, and the average value of the single line of data torque readings, which is the test bench friction torque at the speed, and is recorded as the test bench's own friction torque limit value data; 3) Drag torque limitation: After the test sample is loaded onto the test bench, it is towed by the test bench when not in operation to test and obtain the drag torque limit data; 4) Electric drive assembly efficiency test: 4-1) Set the efficiency test operating point: measure different torques at the same speed, the absolute value of the torque increases from small to large, unload after loading and then load the new torque, the efficiency test operating point is; the torque rise time is not less than 2s, the torque rise stabilization time is not less than 3s, and the effective test time is not less than 5s, and the time is evenly divided to take the value at several intervals; 4-2) Define the test boundaries: at least including bus voltage, torque rise time, torque rise stabilization time, and test time for each torque point; 4-3) Set the efficiency test operating point for the voltage and current sensors on the test bench, and test from high to low. Do not skip the test during the test. 4-4) Record the power generation condition data of each control point; 5) Using the test bench’s own friction torque limit value data and drag torque limit data, a program for determining the efficiency of the electric drive assembly with a unified test boundary is formed.

2. A method for testing the efficiency of an electric drive assembly according to claim 1, characterized in that: The test sample needs to be tested for the friction torque of the test stand itself before installation and after removal of the test stand; step 2) also includes: 2-1) Confirm that the half-axle hub bearing or spline flange is disconnected from the bench connection flange; 2-2) The test bench is disabled and the torque / speed sensor is zeroed.

3. A method for testing the efficiency of an electric drive assembly according to claim 2, characterized in that: In step 2-2), when the torque / speed sensor cannot be adjusted to zero, record the corresponding reading.

4. A method for testing the efficiency of an electric drive assembly according to claim 3, characterized in that: Each time the bench friction torque is tested, three sets of data need to be measured repeatedly. After each set of measurements, the bench dynamometer needs to be reversed to a speed of 500r / s for no less than 30s.

5. A method for testing the efficiency of an electric drive assembly according to claim 4, characterized in that: Step 3) includes: 3-1) Record at least the half-shaft A speed, half-shaft B speed, half-shaft A torque, half-shaft B torque, and total torque at the wheel end speeds of 0 rpm, 10 rpm, 25 rpm, 50 rpm, and 100 rpm; 3-2) The test sample enters the standby mode at low voltage and then enters the high voltage state of not less than 730V; 3-3) The test bench is accelerated at a speed not higher than 20r / S for 5-8s; 3-4) Set no less than 3 intervals and record the drag loss value; 3-5) Perform drag loss measurements at least three times, and when the deviation is no more than 10%, obtain the drag torque data using the average value.

6. A method for testing the efficiency of an electric drive assembly according to claim 5, characterized in that: The electric drive and dynamometer under test are both in standby mode, and the torque sensor reading is not 0. It is necessary to record the torque zero drift once before and after the efficiency and drag tests.

7. A method for testing the efficiency of an electric drive assembly according to claim 6, characterized in that: During the test, the oil temperature must be maintained at 65℃-85℃, the oil cooling system must be circulated, and the preheating condition must be set to 500rpm, 150N.

8. A method for testing the efficiency of an electric drive assembly according to claim 7, characterized in that: Step 5) requires material quantity recording, which at least includes the specified motor torque, the specified left / right half-shaft speed, the specified left / right half-shaft torque, the actual left / right half-shaft speed, and the actual left / right half-shaft torque.

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