Electric drive system efficiency test compensation method, storage medium and program product

Abstract

The invention relates to an electric drive system efficiency test compensation method, a storage medium and a program product, and relates to the technical field of new energy automobiles. The method is executed by a rack control system, and comprises the following steps: acquiring mechanical friction torque and friction mechanical power when a dynamometer idles; collecting the line resistance of a direct current bus between a power battery of the vehicle and a motor controller and the line resistance of a three-phase end line between a motor of the vehicle and the motor controller before the efficiency test; relevant parameters in the efficiency testing process are collected, wherein the relevant parameters comprise direct-current bus current, direct-current bus power, U-phase current, V-phase current, W-phase current, three-phase electric power, dynamometer rotating speed, dynamometer actual measurement torque and dynamometer mechanical power; according to the friction mechanical power, the line resistance of the direct current bus, the line resistance of the three-phase end line and related parameters, the efficiency compensation of the electric driving system is calculated, so that the accuracy of the efficiency test compensation calculation of the electric driving system is improved.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of new energy vehicle technology, and in particular to an electric drive system efficiency test compensation method, storage medium, and program product. Background Art

[0002] With the rapid development of the new energy vehicle industry, efficiency index is one of the important indicators for evaluating motors, electronic controls and electric drive systems in the new energy vehicle industry. At present, with the increasing development of new energy vehicles, users' requirements for the range of new energy vehicles are constantly increasing, and improving efficiency and reducing power consumption have become important solutions.

[0003] In related technologies, engineers obtain the initial temperature and initial resistance of the busbar cable and three-phase cable before the electric drive system test, the test current, test temperature, and test power during the test, and calculate the test resistance of the busbar cable and three-phase cable based on these data. Ultimately, they obtain the compensated electric drive system efficiency to improve the compensated electric drive system efficiency, making it closer to the actual efficiency after the motor and controller are integrated.

[0004] However, the above-mentioned efficiency test and compensation method of the electric drive system is relatively simple, and the accuracy of the electric drive system efficiency test and compensation calculation is low. Summary of the Invention

[0005] The present invention provides an electric drive system efficiency test compensation method, storage medium, and program product, which can improve the accuracy of the electric drive system efficiency test compensation efficiency calculation. The technical solution is as follows:

[0006] In one aspect, a method for compensating for an electric drive system efficiency test is provided, the method being executed by a test bench control system and comprising:

[0007] Obtain the mechanical friction torque and friction mechanical power when the dynamometer is idling;

[0008] The line resistance of the DC bus between the power battery and the motor controller of the vehicle before the acquisition efficiency test and the line resistance of the three-phase terminal line between the motor of the vehicle and the motor controller;

[0009] Collect relevant parameters during the efficiency test, including DC bus current, DC bus power, U-phase current, V-phase current, W-phase current, three-phase power, dynamometer speed, dynamometer measured torque, and dynamometer mechanical power;

[0010] The efficiency compensation of the electric drive system is calculated according to the friction mechanical power, the line resistance of the DC bus, the line resistance of the three-phase end line and the relevant parameters.

[0011] In another aspect, a device for testing and compensating efficiency of an electric drive system is provided, the device comprising:

[0012] An acquisition module is used to obtain the mechanical friction torque and friction mechanical power when the dynamometer is idling;

[0013] A first acquisition module is used to acquire the line resistance of the DC bus between the power battery and the motor controller of the vehicle and the line resistance of the three-phase terminal line between the motor of the vehicle and the motor controller before the efficiency test;

[0014] The second acquisition module is used to collect relevant parameters during the efficiency test, wherein the relevant parameters include DC bus current, DC bus power, U-phase current, V-phase current, W-phase current, three-phase power, dynamometer speed, dynamometer measured torque, and dynamometer mechanical power;

[0015] A calculation module is used to calculate the efficiency compensation of the electric drive system according to the friction mechanical power, the line resistance of the DC bus, the line resistance of the three-phase end line and the relevant parameters.

[0016] In one possible implementation, the first acquisition module is used to collect the resistance between the DC bus end current sensor acquisition point and the electronic control end wiring harness before the test, the resistance of the U-phase wiring harness between the controller end and the current sensor acquisition point before the test, the resistance of the V-phase wiring harness between the controller end and the current sensor acquisition point before the test, the resistance of the W-phase wiring harness between the controller end and the current sensor acquisition point before the test, the resistance of the U-phase wiring harness between the motor end and the current sensor acquisition point before the test, the resistance of the V-phase wiring harness between the motor end and the current sensor acquisition point before the test, and the resistance of the W-phase wiring harness between the motor end and the current sensor acquisition point before the test.

[0017] In a possible implementation, the calculation module is configured to calculate the motor efficiency based on the friction mechanical power, the line resistance of the DC bus, the line resistance of the three-phase terminal line, and the relevant parameters, where the motor efficiency is the ratio of the power of the motor to the power of the motor controller;

[0018] Calculating the electric control efficiency according to the line resistance of the DC bus, the line resistance of the three-phase terminal line and the relevant parameters, where the electric control efficiency is the ratio of the power of the motor controller to the power of the power battery;

[0019] The product of the motor efficiency and the electric control efficiency is obtained as efficiency compensation of the electric drive system.

[0020] In a possible implementation, the calculation module is configured to calculate the motor efficiency using the following formula based on the friction mechanical power, the line resistance of the DC bus, the line resistance of the three-phase terminal line, and the relevant parameters:

[0021] Motor efficiency = (P mech +P mech_loss ) / (P ac -I u ^2·R u2 -I v ^2·R v2 -I w ^2·R w2 )

[0022] Among them, the P mech is the mechanical power of the dynamometer, the P mech_loss is the friction mechanical power, the P ac is the three-phase electric power, the I u is the U phase current, the R u2 is the U-phase harness resistance between the motor end and the current sensor collection point before the test, the I v is the W phase current, the R v2 is the V-phase harness resistance between the motor end and the current sensor collection point before the test, Iw is the W-phase current, and R w2 is the W-phase harness resistance between the motor end and the current sensor collection point before the test;

[0023] The electric control efficiency is calculated according to the line resistance of the DC bus, the line resistance of the three-phase end line and the related parameters using the following formula:

[0024] Electronic control efficiency = (P ac +I u ^2·R u1 +I v ^2·R v1 +I w ^2·R w1 ) / (P dc -2·I dc+ ^2R dc+ )

[0025] Among them, the P ac is the three-phase electric power, the I u is the U phase current, the R u1 is the U-phase harness resistance between the controller end and the current sensor collection point before the test, the I v is the V phase current, the R v1is the V-phase harness resistance between the controller end and the current sensor collection point before the test, the I w is the W phase current, the R w1 is the W-phase harness resistance between the controller end and the current sensor collection point before the test, the P dc is the DC bus power, the I dc+ is the DC bus current, the R dc+ is the DC bus power.

[0026] In a possible implementation, the apparatus further includes:

[0027] The operation control module is used to control the dynamometer to operate in the same rotation direction as that during the rated efficiency test of the motor under test before obtaining the mechanical friction torque and friction mechanical power when the dynamometer is idling, so as to simulate the friction state under the actual test environment.

[0028] In one possible implementation, the acquisition module is used to measure from low speed to high speed in sequence after the dynamometer reaches a hot state; start measurement after each speed point is stable for N seconds, and collect M groups of data, where N and M are integers greater than or equal to 2; perform outlier removal on the M groups of data; determine the mechanical friction torque of the dynamometer when idling based on the M groups of data that have undergone the outlier removal; and determine the friction mechanical power based on the mechanical friction torque of the dynamometer when idling.

[0029] On the other hand, a computer device is provided, which includes a processor and a memory, wherein the memory stores at least one instruction, at least one program, code set or instruction set, and the at least one instruction, at least one program, code set or instruction set is loaded and executed by the processor to implement the electric drive system efficiency test compensation method as described above.

[0030] On the other hand, a computer-readable storage medium is provided, in which at least one instruction, at least one program, code set or instruction set is stored, and the at least one instruction, the at least one program, the code set or instruction set is loaded and executed by a processor to implement the electric drive system efficiency test compensation method as described above.

[0031] In yet another aspect, a computer program product is provided, comprising a computer program stored in a computer-readable storage medium. A processor of a computer device reads the computer program from the computer-readable storage medium and executes the computer program, causing the computer device to perform the electric drive system efficiency test and compensation methods provided in the various optional implementations described above.

[0032] The technical solution provided by this application may have the following beneficial effects:

[0033] By obtaining the mechanical friction torque and friction mechanical power when the dynamometer is idling, the energy loss of the dynamometer itself can be accurately evaluated in the no-load state. At the same time, by collecting the line resistance of the DC bus between the power battery and the motor controller and the line resistance of the three-phase end line between the motor and the motor controller, the resistive loss in the line can be quantified. Collecting multiple key parameters during the efficiency test process helps to comprehensively analyze the energy flow state of the electric drive system during operation. Based on the above data, the efficiency compensation of the electric drive system is calculated in combination with the friction mechanical power, line resistance and real-time parameters, which effectively improves the accuracy of the efficiency compensation calculation of the electric drive system.

[0034] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0036] Figure 1 This is a system configuration diagram of an electric drive system efficiency test and compensation system according to one embodiment of the present application;

[0037] Figure 2 This is a flow chart of an electric drive system efficiency test and compensation method provided by one embodiment of the present application;

[0038] Figure 3 This is a flow chart of an electric drive system efficiency test and compensation method provided by one embodiment of the present application;

[0039] Figure 4 This is a schematic structural diagram of an efficiency test for an electric drive system of a new energy vehicle provided by an exemplary embodiment of the present application;

[0040] Figure 5 This is a flow chart of a new energy vehicle electric drive system efficiency test and compensation method provided by an exemplary embodiment of the present application;

[0041] Figure 6 is a block diagram of an electric drive system efficiency test and compensation device provided by an exemplary embodiment of the present application;

[0042] Figure 7 It is a structural diagram of a computer device provided by an exemplary embodiment of the present application. DETAILED DESCRIPTION

[0043] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.

[0044] Please refer to Figure 1 , Figure 1 FIG. 1 is a system diagram of an electric drive system efficiency test and compensation system according to an embodiment of the present application. Figure 1 As shown, the system structure diagram includes a test bench control system 100, a power battery 101, a motor controller 102, a motor 103 and a dynamometer 104. The test bench control system 100 is connected to the power battery 101 and the dynamometer 104 respectively through a communication control harness. The power battery 101 is connected to the motor controller 102 through a DC bus. The motor controller 102 is connected to the motor 103 through a three-phase terminal line. The motor 103 is connected to the dynamometer 104 through a communication control harness.

[0045] The test bench control system 100 can obtain the mechanical friction torque and friction mechanical power when the dynamometer is idling; collect the line resistance of the DC bus between the vehicle's power battery and the motor controller and the line resistance of the three-phase end line between the vehicle's motor and the motor controller before the efficiency test; collect the relevant parameters corresponding to the DC bus and the three-phase end lines during the efficiency test, and the relevant parameters include DC bus current, DC bus power, U-phase current, V-phase current, W-phase current, three-phase electric power, dynamometer speed, dynamometer measured torque, and dynamometer mechanical power; calculate the efficiency compensation of the electric drive system based on the friction mechanical power, the line resistance of the DC bus, the line resistance of the three-phase end lines and related parameters.

[0046] Please refer to Figure 2 , Figure 2 This is a flow chart of an electric drive system efficiency test compensation method provided by an embodiment of the present application. The electric drive system efficiency test compensation method can be executed by a test bench control system, for example, the test bench control system can be the above-mentioned Figure 1 The test bench control system 100 shown in FIG. 1 may include the following steps:

[0047] Step 210: Obtain the mechanical friction torque and friction mechanical power of the dynamometer when it is idling.

[0048] The dynamometer is a device used to measure the output torque and speed of a motor.

[0049] The idling mentioned above refers to a state in which the motor drives the dynamometer to rotate but there is no external load.

[0050] The mechanical friction torque is the resistance torque generated by the friction between mechanical components such as bearings and gears when the dynamometer is idling.

[0051] The friction mechanical power is a power value obtained by multiplying the mechanical friction torque by the dynamometer speed when the dynamometer is idling. The friction mechanical power represents the energy lost by the dynamometer itself due to friction.

[0052] In an embodiment of the present application, the test bench control system operates the dynamometer under no-load conditions, records the rotational speed and mechanical friction torque of the dynamometer, and calculates the friction mechanical power based on the rotational speed and mechanical friction torque.

[0053] For example, within the rated test speed range of the motor, the friction torque is measured every 500 rpm from 500 rpm to 6000 rpm, stable data is collected for more than 3 seconds at each point, and the average value is taken as the friction power at that speed.

[0054] Step 220: Collect the line resistance of the DC bus between the vehicle's power battery and the motor controller and the line resistance of the three-phase terminal line between the vehicle's motor and the motor controller before the efficiency test.

[0055] Among them, the above-mentioned power battery is a high-voltage energy storage device that powers the motor, such as a lithium-ion battery pack.

[0056] Among them, the above-mentioned motor controller is the central control unit that controls the power system of the entire vehicle.

[0057] Among them, the above-mentioned DC bus is the main power transmission line connecting the power battery and the motor controller.

[0058] The three-phase terminal line is a three-phase AC power transmission line connecting the motor controller and the motor.

[0059] The line resistance of the DC bus between the vehicle's power battery and the motor controller refers to the resistance between the main power transmission line between the power battery and the motor controller; the line resistance of the three-phase terminal line between the vehicle's motor and the motor controller refers to the resistance between the three-phase AC power transmission line between the motor controller and the motor.

[0060] In an embodiment of the present application, the test bench control system can use a high-precision micro-ohmmeter or a four-wire resistance meter to measure the U / V / W three-phase wiring harness resistance from the positive and negative poles of the power battery to the motor controller, and from the motor controller to the motor junction box in the power-off state.

[0061] Step 230: Collect relevant parameters during the efficiency test, including DC bus current, DC bus power, U-phase current, V-phase current, W-phase current, three-phase power, dynamometer speed, dynamometer measured torque, and dynamometer mechanical power.

[0062] Among them, the DC bus current refers to the current flowing through the DC bus, and the DC bus current reflects the power supply of the power battery to the vehicle control system.

[0063] Among them, the DC bus power is the product of the DC bus voltage and current, which represents the power output of the power battery.

[0064] Among them, the U / V / W phase current is the current flowing through the three-phase AC wiring harness, corresponding to the three-phase windings of the motor respectively.

[0065] Among them, the three-phase electric power is the sum of the products of the three-phase voltage and current, which represents the power output by the vehicle control system to the motor.

[0066] The dynamometer speed is the actual rotation speed of the dynamometer.

[0067] The dynamometer measured torque is the actual output torque of the dynamometer.

[0068] The dynamometer mechanical power is the mechanical output power obtained by multiplying the dynamometer speed by the dynamometer measured torque.

[0069] In the embodiment of the present application, the test bench control system can collect the above parameters in real time through a high-speed data acquisition module. For the parameters on the DC side, Hall current sensors and voltage probes can be used, and for the parameters on the three-phase side, shunts or Rogowski coils combined with voltage transformers can be used for sampling.

[0070] Step 240: Calculate the efficiency compensation of the electric drive system according to the friction mechanical power, the line resistance of the DC bus, the line resistance of the three-phase terminal line, and related parameters.

[0071] The efficiency compensation of the electric drive system refers to the actual efficiency value of the electric drive system corrected after taking into account factors such as line loss and dynamometer friction.

[0072] In an embodiment of the present application, by obtaining the mechanical friction torque and friction mechanical power when the dynamometer is idling, the energy loss of the dynamometer itself in a no-load state can be accurately evaluated. At the same time, by collecting the line resistance of the DC bus between the power battery and the motor controller and the line resistance of the three-phase end line between the motor and the motor controller, the resistive loss in the line can be quantified. Collecting multiple key parameters during the efficiency test helps to comprehensively analyze the energy flow state of the electric drive system during operation. Based on the above data, the efficiency compensation of the electric drive system is calculated in combination with the friction mechanical power, line resistance and real-time parameters, which effectively improves the accuracy of the efficiency compensation calculation of the electric drive system.

[0073] Based on the scheme shown in any corresponding one or more embodiments above, in a possible implementation method, the above step 220 can be implemented as: collecting the resistance between the current sensor collection point at the DC bus end and the electrical control end wiring harness before the test, the resistance of the U-phase wiring harness between the controller end and the current sensor collection point before the test, the resistance of the V-phase wiring harness between the controller end and the current sensor collection point before the test, the resistance of the W-phase wiring harness between the controller end and the current sensor collection point before the test, the resistance of the U-phase wiring harness between the motor end and the current sensor collection point before the test, the resistance of the V-phase wiring harness between the motor end and the current sensor collection point before the test, and the resistance of the W-phase wiring harness between the motor end and the current sensor collection point before the test.

[0074] The current sensor collection point is a location for detecting the DC bus current, which is usually a location where a Hall current sensor or a shunt is installed.

[0075] Among them, the above-mentioned electronic control end is the motor controller end.

[0076] The harness resistance from the current sensor collection point at the DC bus end to the electronic control end refers to the resistance value formed by the conductor material and connectors between the current sensor collection point and the electronic control end.

[0077] In an embodiment of the present application, the test bench control system can measure the resistance value from the current sensor collection point to the positive and negative input terminals of the motor controller respectively in the power-off state, and obtain the wiring harness resistance from the current sensor collection point at the DC bus end to the electronic control end before the test.

[0078] In an embodiment of the present application, the gantry control system can measure the harness resistance between the three-phase output terminals of the motor controller and the current sensor collection points respectively when the power is off.

[0079] In an embodiment of the present application, the test bench control system can measure the wiring harness resistance between the three-phase output end of the motor end and the current sensor collection point in a power-off state.

[0080] In the embodiment of the present application, the process of collecting the harness resistance is further refined, and it is clearly pointed out that it is necessary to measure the line resistance of the DC bus from the power battery to the electronic control end, as well as the resistance of different sections of the U / V / W three-phase harness between the controller and the motor. The segmented resistance measurement method can more accurately identify the resistance differences that may exist in each circuit. By collecting the resistance of each section and using the collected resistance for subsequent calculations, the line loss calculation is more precise, avoiding efficiency errors caused by ignoring local resistance, and ensuring the comprehensiveness of the collected line resistance.

[0081] Based on the solutions shown in any one or more of the above embodiments, in one possible implementation, Figure 2 Step 240 can be implemented as follows: calculating the motor efficiency based on the friction mechanical power, the line resistance of the DC bus, the line resistance of the three-phase end line and related parameters, where the motor efficiency is the ratio of the power of the motor to the power of the motor controller; calculating the electronic control efficiency based on the line resistance of the DC bus, the line resistance of the three-phase end line and related parameters, where the electronic control efficiency is the ratio of the power of the motor controller to the power of the power battery; obtaining the product of the motor efficiency and the electronic control efficiency as the efficiency compensation of the electric drive system.

[0082] In the embodiment of the present application, the motor efficiency is obtained by the ratio of the mechanical power output by the dynamometer to the motor input power after deducting the line loss, which reflects the actual working capacity of the motor; the electronic control efficiency is determined by the ratio of the motor input power to the battery output power, which reflects the energy conversion efficiency of the electronic control device. Through hierarchical calculation, independent evaluation of the performance of the motor and the electronic control can be achieved, thereby improving the reliability and accuracy of the calculation results of the efficiency compensation of the electric drive system.

[0083] Based on the solutions shown in any corresponding one or more embodiments above, in one possible implementation, the test bench control system can calculate the motor efficiency according to the friction mechanical power, the line resistance of the DC bus, the line resistance of the three-phase end line, and related parameters using the following formula:

[0084] Motor efficiency = (P mech +P mech_loss ) / (P ac -I u ^2·R u2 -I v ^2·R v2 -I w ^2·R w2 )

[0085] Among them, P mech is the dynamometer mechanical power, P mech_loss is the frictional mechanical power, P ac is the three-phase electric power, I u is the U phase current, R u2It is the U-phase harness resistance between the motor end and the current sensor collection point before the test, I v is the W phase current, R v2 It is the V-phase harness resistance between the motor end and the current sensor collection point before the test, I w is the W phase current, R w2 It is the W-phase harness resistance between the motor end and the current sensor collection point before the test.

[0086] In the embodiment of the present application, the above formula calculates the motor efficiency by adding the actual measured mechanical power to the friction loss as the effective output power of the motor and deducting the actual input power after the motor side line loss. mech +P mech_loss ), represents the actual mechanical power output of the motor, the denominator: (P ac -I u ^2·R u2 -I v ^2·R v2 -I w ^2·R w2 ), represents the net electrical energy actually received by the motor. This formula accurately evaluates the motor's energy conversion efficiency, taking into account friction losses in the dynamometer and wiring losses on the motor side.

[0087] The above step 240 can be implemented as follows: according to the line resistance of the DC bus, the line resistance of the three-phase end line and related parameters, the electric control efficiency is calculated by the following formula:

[0088] Electronic control efficiency = (P ac +I u ^2·R u1 +I v ^2·R v1 +I w ^2·R w1 ) / (P dc -2·I dc+ ^2R dc+ )

[0089] Among them, P ac is the three-phase electric power, I u is the U phase current, R u1 It is the U-phase harness resistance between the controller end and the current sensor collection point before the test, I v is the V phase current, R v1 It is the V phase harness resistance between the controller end and the current sensor collection point before the test, I w is the W phase current, R w1 It is the resistance of the W phase wiring harness between the controller end and the current sensor collection point before the test, P dc is the DC bus power, I dc+is the DC bus current, R dc+ is the DC bus power.

[0090] In the embodiment of the present application, the above formula calculates the energy conversion efficiency of the electric control system by adding the three-phase power output by the controller to the line loss on its output side as the actual output energy of the controller; and subtracting the DC bus line loss from the battery output power as the input energy of the controller. Wherein, the numerator: (P ac +I u ^2·R u1 +I v ^2·R v1 +I w ^2·R w1 ), represents the controller output plus transmission loss, the denominator: (P dc -2·I dc+ ^2R dc+ ), which represents the controller input minus DC line losses. This formula accurately estimates the efficiency of the electronic control system in converting DC power to three-phase AC power by correcting the electrical parameters of the controller's front and back ends.

[0091] In the embodiment of the present application, the motor efficiency formula takes into account the influence of the dynamometer mechanical power, friction loss, three-phase current and motor side wiring resistance, thereby improving the accuracy of the calculation of the effective power actually output by the motor; the electronic control efficiency formula takes into account factors such as three-phase electric power, controller side wire loss and DC bus power, which can accurately reflect the energy conversion process of the electronic control device and improve the accuracy of the electronic control efficiency calculation.

[0092] based on Figure 2 The embodiment shown, referring to Figure 3 , which shows a flow chart of an electric drive system efficiency test compensation method provided by an embodiment of the present application. Figure 3 As shown, step 200 is also included before step 210, and the details are as follows.

[0093] Step 200: Control the dynamometer to run in the same rotation direction as that during the rated efficiency test of the motor under test, so as to simulate the friction state under the actual test environment.

[0094] The motor under test is a motor whose efficiency and output characteristics are to be tested, and is generally a vehicle drive motor.

[0095] The above-mentioned simulated real test environment is to ensure that the operating conditions of the dynamometer during the no-load test phase are consistent with those during the actual load test.

[0096] In an embodiment of the present application, before formally obtaining the idling friction parameters of the dynamometer, the bench test system must first set the dynamometer to run in the same rotation direction as that of the subsequent motor efficiency test. This can be achieved through software control or physical wiring, and the dynamometer is controlled to maintain stable operation for a certain period of time under no-load conditions, so that the internal temperature and friction state of the dynamometer approach the actual test state.

[0097] In an embodiment of the present application, before obtaining the idling friction parameters of the dynamometer, the bench test system needs to operate the dynamometer in the same rotation direction as the motor rated efficiency test to simulate the actual test environment, ensure the consistency of the internal friction state of the dynamometer and the actual working state, and avoid friction characteristic deviations caused by different rotation directions. Using the same rotation direction can put the dynamometer in a stress state similar to the actual test, thereby improving the accuracy of the no-load friction parameters, laying a more realistic foundation for subsequent efficiency compensation calculations, and helping to improve the accuracy of the overall efficiency compensation calculations.

[0098] Based on the solutions shown in any corresponding one or more embodiments above, in a possible implementation method, the above step 200 can be implemented as follows: after the dynamometer reaches a hot state, measurements are performed in sequence from low speed to high speed; measurement is started after each speed point is stable for N seconds, and M groups of data are collected, where N and M are integers greater than or equal to 2; outlier removal is performed on each of the M groups of data; the mechanical friction torque of the dynamometer when idling is determined based on the M groups of data after outlier removal is performed; and the friction mechanical power is determined based on the mechanical friction torque of the dynamometer when idling.

[0099] The above-mentioned hot state refers to the operating condition in which the temperature of the dynamometer tends to be stable during continuous operation.

[0100] In the embodiment of the present application, in order to ensure that the internal bearings, lubrication system and other components of the dynamometer are in a real working state, the bench test system needs to let the dynamometer run for a period of time before the formal measurement until its temperature stabilizes (i.e., "hot state"), and then test it step by step from low speed to high speed in a predetermined order.

[0101] For example, in a test of a new energy vehicle drive motor, the dynamometer is idle for 10 minutes in the direction of rotation during the rated efficiency test under no-load conditions. After the temperature of the dynamometer rises from the initial room temperature to 60°C and stabilizes, measurements are taken every 500 rpm starting from 500 rpm until 6000 rpm.

[0102] The above-mentioned speed points refer to the specific speed values ​​set during the test.

[0103] The M sets of data collected are repeatedly sampled M times at the same rotation speed point to improve the reliability of the collected data.

[0104] In the embodiment of the present application, an automatic control program is provided at each speed point, so that after the dynamometer runs stably at the set speed for N seconds, the data acquisition module is triggered to record M measurement values, with each interval not exceeding 1 second.

[0105] The above-mentioned outliers refer to data points that deviate from the normal range, and the outliers may be caused by instantaneous interference, sensor drift or system instability.

[0106] Among them, the above-mentioned outlier elimination refers to identifying and eliminating data points that do not meet the expected range through statistical methods (such as the quartile method).

[0107] In the embodiment of the present application, after removing outliers from the M sets of data, the bench test system takes the arithmetic mean or weighted mean of the remaining data as the friction torque value at the speed point. For example, after removing one outlier, the average of four values ​​is taken.

[0108] In the embodiment of the present application, after obtaining the friction torque value at a specific speed, the friction mechanical power at the corresponding speed is calculated using the known speed and friction torque values. Specifically, the friction mechanical power is equal to the friction torque multiplied by the speed, divided by a coefficient used to convert the units from speed and torque to power units.

[0109] In the examples of this application, the process for acquiring the idling friction torque of a dynamometer is described in detail. After the dynamometer reaches a hot state, measurements are performed sequentially from low to high speeds, and M sets of data are collected after each speed point stabilizes for N seconds. By measuring after heating, the dynamometer is more closely aligned with actual operating conditions, resulting in data that is more consistent with actual conditions. By removing outliers from each set of data, accidental interference factors are effectively eliminated, improving the stability and reliability of the collected data. The mechanical friction torque is determined based on this data after outliers have been removed, effectively improving the accuracy of the mechanical friction torque determination during idling of the dynamometer.

[0110] For example, based on Figures 2 to 3 Corresponding to any one or more embodiments, the embodiments of the present application propose a new energy vehicle electric drive system motor, motor controller and system efficiency test and compensation method.

[0111] Please refer to Figure 4 , which shows a schematic structural diagram of an efficiency test of a new energy vehicle electric drive system provided by an exemplary embodiment of the present application. Figure 4 As shown, Figure 4 The system includes a test bench control system 401 , a battery simulator 402 , a motor controller 403 , a drive motor 404 , a power analyzer 405 , a dynamometer 406 , a low-voltage DC power supply 407 and a connection board 40 .

[0112] The test bench control system 401 is connected to the battery simulator 402, the motor controller 403, the power analyzer 405 and the dynamometer 406 through the communication control harness; the battery simulator 402 is connected to the motor controller 403 through the DC bus, and there are DC current collection points and DC voltage collection points on the DC bus; the DC current collection points and the DC voltage collection points are connected to the power analyzer 405 respectively; the motor controller 403 is connected to the drive motor 404 through a three-phase harness, and there are three-phase AC current collection points and AC voltage collection points on the three-phase harness, and the three-phase AC current collection points and AC voltage collection points are connected to the power analyzer 405 respectively; the drive motor 404 is connected to the dynamometer 406 through the connecting plate 40; the low-voltage DC power supply 407 is connected to the motor controller 403 through a low-voltage connecting harness.

[0113] based on Figure 4 Please refer to the system environment diagram of the new energy vehicle electric drive system efficiency test shown in the figure. Figure 5 , which shows a flow chart of a new energy vehicle electric drive system efficiency test compensation method provided by an exemplary embodiment of the present application. Figure 5 As shown, the method includes the following steps.

[0114] Step S1: Measuring the idling mechanical friction torque of the dynamometer

[0115] The test bench control system 401 is unloaded before the test (the motor under test is not installed), and the redundant friction pairs are removed. The rotation direction of the dynamometer 406 is required to be consistent with the rotation direction of the motor under test during the efficiency test. Before the test, the dynamometer 406 idles at the rated speed of the motor under test for 8 minutes and idles at the peak speed for 3 minutes to make the dynamometer 406 reach a hot state. During the test, the idling speed point can be the same as the speed point of the efficiency test motor. The speed is measured from low speed to high speed. Each speed point is stable for 3 seconds before the measurement begins, and 5 sets of data are measured. After the measurement is completed, the idling torque data is processed and the average T1 and idling friction mechanical power P are taken after the abnormal data points are eliminated. mech_loss , keep three decimal places.

[0116] Step S2: Measure the DC bus line resistance and three-phase end line resistance

[0117] Before testing, measure the wiring harness resistance R from the DC bus current sensor collection point to the electronic control end dc+ ;

[0118] Before the test, measure the U-phase harness resistance R between the controller end and the current sensor collection point. u1 ;

[0119] Before testing, measure the V-phase harness resistance R between the controller end and the current sensor collection point. v1 ;

[0120] Before the test, measure the W phase harness resistance R between the controller end and the current sensor collection point w1 ;

[0121] Before testing, measure the U-phase harness resistance R between the motor end and the current sensor collection point. u2 ;

[0122] Before testing, measure the V-phase harness resistance R between the motor end and the current sensor collection point. v2 ;

[0123] Before testing, measure the W-phase harness resistance R between the motor end and the current sensor collection point. w2 .

[0124] Step S3: Collect relevant parameters such as current, power, torque, etc. during the efficiency test

[0125] Collect DC bus current I dc+ , DC bus power P dc , U phase current I u , V phase current I v , W phase current I w , three-phase power P ac , dynamometer speed N, dynamometer measured torque T, dynamometer mechanical power P mech Other related parameters are used for efficiency calculation.

[0126] Step S4: Efficiency compensation calculation

[0127] η Motor efficiency = (P mech +P mech_loss ) / (P ac -I u ^2·R u2 -I v ^2·R v2 -I w ^2·R w2 )

[0128] ηElectronic control efficiency=(P ac +I u ^2·R u1 +I v ^2·R v1 +I w ^2·R w1 ) / (P dc -2·I dc +^2R dc+ )

[0129] η system efficiency = η motor efficiency * η electronic control efficiency

[0130] Note: The above is the calculation formula for the motor drive direction. The power values ​​involved in the calculation are all positive numbers (the dynamometer idling friction torque T1 and the dynamometer measured torque T are both positive numbers)

[0131] In the embodiment of the present application, this technical solution can make up for the shortcomings of the current efficiency test in the calculation method, which is conducive to the acceptance of efficiency indicators and meets the development work of high-quality electric drive systems.

[0132] The above is merely an example of an embodiment of the present application and should not be construed as limiting the present application. Professionals should understand that various variations and modifications may be made to the embodiment to accommodate different application requirements. Therefore, the scope of the present application should be defined by the claims appended hereto.

[0133] Please refer to Figure 6 , which shows a block diagram of an electric drive system efficiency test compensation device provided by an exemplary embodiment of the present application. The electric drive system efficiency test compensation device can be implemented as all or part of the test bench control system by hardware or a combination of hardware and software to achieve the above-mentioned Figures 2 to 3 All or part of the steps in the embodiment shown. Figure 6 As shown, the electric drive system efficiency test compensation device includes:

[0134] An acquisition module 601 is used to acquire the mechanical friction torque and friction mechanical power of the dynamometer when the dynamometer is idling;

[0135] A first acquisition module 602 is configured to acquire the line resistance of the DC bus between the vehicle's power battery and the motor controller and the line resistance of the three-phase terminal line between the vehicle's motor and the motor controller before the efficiency test;

[0136] The second acquisition module 603 is used to collect relevant parameters corresponding to the DC bus and the three-phase end lines during the efficiency test, including DC bus current, DC bus power, U-phase current, V-phase current, W-phase current, three-phase power, dynamometer speed, dynamometer measured torque, and dynamometer mechanical power;

[0137] The calculation module 604 is used to calculate the efficiency compensation of the electric drive system according to the friction mechanical power, the line resistance of the DC bus, the line resistance of the three-phase terminal line and related parameters.

[0138] In one possible implementation, the first acquisition module 602 is used to collect the resistance between the current sensor acquisition point at the DC bus end and the electrical control end wiring harness before the test, the resistance of the U-phase wiring harness between the controller end and the current sensor acquisition point before the test, the resistance of the V-phase wiring harness between the controller end and the current sensor acquisition point before the test, the resistance of the W-phase wiring harness between the controller end and the current sensor acquisition point before the test, the resistance of the U-phase wiring harness between the motor end and the current sensor acquisition point before the test, the resistance of the V-phase wiring harness between the motor end and the current sensor acquisition point before the test, and the resistance of the W-phase wiring harness between the motor end and the current sensor acquisition point before the test.

[0139] In one possible implementation, the calculation module 604 is configured to calculate the motor efficiency based on the friction mechanical power, the line resistance of the DC bus, the line resistance of the three-phase terminal line, and related parameters. The motor efficiency is the ratio of the motor power to the motor controller power.

[0140] The electric control efficiency is calculated based on the line resistance of the DC bus, the line resistance of the three-phase terminal line and related parameters. The electric control efficiency is the ratio of the power of the motor controller to the power of the power battery.

[0141] The product of the motor efficiency and the electronic control efficiency is obtained as the efficiency compensation of the electric drive system.

[0142] In one possible implementation, the calculation module 604 is configured to calculate the motor efficiency using the following formula based on the friction mechanical power, the line resistance of the DC bus, the line resistance of the three-phase terminal line, and related parameters:

[0143] Motor efficiency = (P mech +P mech_loss ) / (P ac -I u ^2·R u2 -I v ^2·R v2 -I w ^2·R w2 )

[0144] Among them, P mech is the dynamometer mechanical power, P mech_loss is the frictional mechanical power, P ac is the three-phase electric power, I u is the U phase current, R u2 It is the U-phase harness resistance between the motor end and the current sensor collection point before the test, I v is the W phase current, R v2 It is the V-phase harness resistance between the motor end and the current sensor collection point before the test, I w is the W phase current, R w2 It is the resistance of the W-phase harness between the motor end and the current sensor collection point before the test;

[0145] It is used to calculate the electric control efficiency according to the line resistance of the DC bus, the line resistance of the three-phase end line and related parameters using the following formula:

[0146] Electronic control efficiency = (P ac +I u ^2·R u1 +I v ^2·R v1 +I w ^2·R w1 ) / (P dc -2·I dc+ ^2R dc+ )

[0147] Among them, P ac is the three-phase electric power, I u is the U phase current, R u1 It is the U-phase harness resistance between the controller end and the current sensor collection point before the test, I v is the V phase current, R v1 It is the V phase harness resistance between the controller end and the current sensor collection point before the test, I w is the W phase current, R w1 It is the resistance of the W phase wiring harness between the controller end and the current sensor collection point before the test, P dc is the DC bus power, I dc+ is the DC bus current, R dc+ is the DC bus power.

[0148] In a possible implementation, the apparatus further includes:

[0149] The operation control module is used to control the dynamometer to operate in the same rotation direction as that during the rated efficiency test of the motor under test before obtaining the mechanical friction torque and friction mechanical power when the dynamometer is idling, so as to simulate the friction state under the actual test environment.

[0150] In one possible implementation, the acquisition module 601 is used to measure from low speed to high speed in sequence after the dynamometer reaches a hot state; start measurement after each speed point is stable for N seconds, and collect M groups of data, where N and M are integers greater than or equal to 2; perform outlier removal on the M groups of data; determine the mechanical friction torque of the dynamometer when idling based on the M groups of data that have undergone outlier removal; and determine the friction mechanical power based on the mechanical friction torque of the dynamometer when idling.

[0151] Please refer to Figure 7 , Figure 77 is a schematic diagram of the structure of a computer device provided by an exemplary embodiment of the present application. The computer device 700 includes a central processing unit (CPU) 701, a system memory 704 including a random access memory (RAM) 702 and a read-only memory (ROM) 703, and a system bus 705 connecting the system memory 704 and the central processing unit 701. The computer device 700 also includes a basic input / output system (I / O system) 706 that helps transfer information between various components within the computer, and a large-capacity storage device 707 for storing an operating system 713, application programs 714, and other program modules 715.

[0152] The basic input / output system 706 includes a display 708 for displaying information and an input device 709 such as a mouse and keyboard for user input. The display 708 and the input device 709 are connected to the central processing unit 701 via an input / output controller 710 connected to the system bus 705. The basic input / output system 706 may also include an input / output controller 710 for receiving and processing input from a variety of other devices such as a keyboard, mouse, or electronic stylus. Similarly, the input / output controller 710 also provides output to a display screen, printer, or other types of output devices.

[0153] The mass storage device 707 is connected to the central processing unit 701 via a mass storage controller (not shown) connected to the system bus 705. The mass storage device 707 and its associated computer-readable media provide non-volatile storage for the computer device 700. In other words, the mass storage device 707 may include a computer-readable medium (not shown) such as a hard disk or a CD-ROM (Compact Disc Read-Only Memory) drive.

[0154] Without loss of generality, the computer-readable medium may include computer storage media and communication media. Computer storage media include volatile and non-volatile, removable and non-removable media implemented using any method or technology for storing information such as computer-readable instructions, data structures, program modules, or other data. Computer storage media include RAM (Random Access Memory), ROM (Read-Only Memory), EPROM (Erasable Programmable Read-Only Memory), EEPROM (Electrically Erasable Programmable Read-Only Memory), flash memory or other solid-state storage technologies, CD-ROM, DVD (Digital Video Disc) or other optical storage, tape cassettes, magnetic tape, disk storage or other magnetic storage devices. Of course, those skilled in the art will appreciate that the computer storage media are not limited to the aforementioned types. The above-mentioned system memory 704 and mass storage device 707 can be collectively referred to as memory.

[0155] The computer device 700 can be connected to the Internet or other network devices through the network interface unit 711 connected to the system bus 705 .

[0156] The memory also includes one or more programs, which are stored in the memory. The central processing unit 701 implements the one or more programs by executing the one or more programs. Figures 2 to 3 All or part of the steps in the method shown.

[0157] In an exemplary embodiment, a chip is also provided, which includes a programmable logic circuit and / or program instructions. When the chip runs on a computer device, it is used to implement all or part of the steps of the method shown in the above embodiments of the present application.

[0158] In an exemplary embodiment, a computer program product is also provided, comprising computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium, reads the computer instructions from the computer-readable storage medium, and executes the computer instructions to implement all or part of the steps of the methods described in the various embodiments of the present application.

[0159] In an exemplary embodiment, a computer-readable storage medium is further provided, in which a computer program is stored. The computer program is loaded and executed by a processor to implement all or part of the steps of the method shown in the above embodiments of the present application.

[0160] Those skilled in the art will understand that all or part of the steps to implement the above embodiments may be accomplished by hardware, or by a program to instruct the relevant hardware, and the program may be stored in a computer-readable storage medium, which may be a read-only memory, a disk, or an optical disk, etc.

[0161] Those skilled in the art will appreciate that in one or more of the above examples, the functions described in the embodiments of the present application can be implemented using hardware, software, firmware, or any combination thereof. When implemented using software, these functions can be stored in a computer-readable medium or transmitted as one or more instructions or codes on a computer-readable medium. Computer-readable media include computer storage media and communication media, wherein communication media include any media that facilitates the transmission of computer programs from one place to another. The storage medium can be any available medium that can be accessed by a general-purpose or special-purpose computer.

[0162] The above description is merely an optional embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A method for compensating an electric drive system efficiency test, characterized in that: The method is executed by a gantry control system, and includes: Obtain the mechanical friction torque and friction mechanical power when the dynamometer is idling; The line resistance of the DC bus between the power battery and the motor controller of the vehicle before the acquisition efficiency test and the line resistance of the three-phase terminal line between the motor of the vehicle and the motor controller; Collect relevant parameters during the efficiency test, including DC bus current, DC bus power, U-phase current, V-phase current, W-phase current, three-phase power, dynamometer speed, dynamometer measured torque, and dynamometer mechanical power; The efficiency compensation of the electric drive system is calculated according to the friction mechanical power, the line resistance of the DC bus, the line resistance of the three-phase end line and the relevant parameters.

2. The method according to claim 1, characterized in that The line resistance of the DC bus between the power battery and the motor controller of the vehicle before the acquisition efficiency test and the line resistance of the three-phase terminal line between the motor of the vehicle and the motor controller include: Collect the resistance between the DC bus end current sensor collection point and the electronic control end wiring harness before the test, the resistance of the U-phase wiring harness between the controller end and the current sensor collection point before the test, the resistance of the V-phase wiring harness between the controller end and the current sensor collection point before the test, the resistance of the W-phase wiring harness between the controller end and the current sensor collection point before the test, the resistance of the U-phase wiring harness between the motor end and the current sensor collection point before the test, the resistance of the V-phase wiring harness between the motor end and the current sensor collection point before the test, and the resistance of the W-phase wiring harness between the motor end and the current sensor collection point before the test.

3. The method according to claim 1, characterized in that The calculating the efficiency compensation of the electric drive system according to the friction mechanical power, the line resistance of the DC bus, the line resistance of the three-phase terminal line, and the related parameters includes: Calculating the motor efficiency according to the friction mechanical power, the line resistance of the DC bus, the line resistance of the three-phase end line, and the relevant parameters, wherein the motor efficiency is the ratio of the power of the motor to the power of the motor controller; Calculating the electric control efficiency according to the line resistance of the DC bus, the line resistance of the three-phase terminal line and the relevant parameters, where the electric control efficiency is the ratio of the power of the motor controller to the power of the power battery; The product of the motor efficiency and the electric control efficiency is obtained as efficiency compensation of the electric drive system.

4. The method according to claim 3, characterized in that The calculating of the motor efficiency according to the friction mechanical power, the line resistance of the DC bus, the line resistance of the three-phase end line and the related parameters includes: The motor efficiency is calculated according to the friction mechanical power, the line resistance of the DC bus, the line resistance of the three-phase end line, and the relevant parameters using the following formula: Motor efficiency = (P mech +P mech_loss ) / (P ac -I u ^2·R u2 -I v ^2·R v2 -I w ^2·R w2 ) Among them, the P mech is the mechanical power of the dynamometer, the P mech_loss is the friction mechanical power, the P ac is the three-phase electric power, the I u is the U phase current, the R u2 is the U-phase harness resistance between the motor end and the current sensor collection point before the test, the I v is the W phase current, the R v2 is the V-phase harness resistance between the motor end and the current sensor collection point before the test, the I w is the W phase current, the R w2 is the W-phase harness resistance between the motor end and the current sensor collection point before the test; The calculating of the electric control efficiency according to the line resistance of the DC bus, the line resistance of the three-phase end line and the related parameters includes: The electric control efficiency is calculated according to the line resistance of the DC bus, the line resistance of the three-phase end line, and the relevant parameters using the following formula: Electronic control efficiency = (P ac +I u ^2·R u1 +I v ^2·R v1 +I w ^2·R w1 ) / (P dc -2·I dc+ ^2R dc+ ) Among them, the P ac is the three-phase electric power, the I u is the U phase current, the R u1 is the U-phase harness resistance between the controller end and the current sensor collection point before the test, the I v is the V phase current, the R v1 is the V-phase harness resistance between the controller end and the current sensor collection point before the test, the I w is the W phase current, the R w1 is the W-phase harness resistance between the controller end and the current sensor collection point before the test, the P dc is the DC bus power, the I dc+ is the DC bus current, the R dc+ is the DC bus power.

5. The method according to claim 1, wherein Before obtaining the mechanical friction torque and friction mechanical power when the dynamometer is idling, the method further includes: The dynamometer is controlled to run in the same rotation direction as that during the rated efficiency test of the motor under test, so as to simulate the friction state under the actual test environment.

6. The method according to claim 1, characterized in that The obtaining of the mechanical friction torque and friction mechanical power when the dynamometer is idling includes: After the dynamometer reaches a hot state, measurements are performed sequentially from low speed to high speed; The measurement starts after each speed point stabilizes for N seconds, and M sets of data are collected, where N and M are integers greater than or equal to 2. Perform outlier removal on the M groups of data respectively; determining the mechanical friction torque of the dynamometer when idling based on the M groups of data after the outlier elimination; The friction mechanical power is determined based on the mechanical friction torque when the dynamometer is idling.

7. An electric drive system efficiency test and compensation device, characterized in that: The device comprises: An acquisition module is used to obtain the mechanical friction torque and friction mechanical power when the dynamometer is idling; A first acquisition module is used to acquire the line resistance of the DC bus between the power battery and the motor controller of the vehicle and the line resistance of the three-phase terminal line between the motor of the vehicle and the motor controller before the efficiency test; a second acquisition module, configured to acquire relevant parameters corresponding to the DC bus and the three-phase end lines during the efficiency test, the relevant parameters including DC bus current, DC bus power, U-phase current, V-phase current, W-phase current, three-phase power, dynamometer speed, dynamometer measured torque, and dynamometer mechanical power; A calculation module is used to calculate the efficiency compensation of the electric drive system according to the friction mechanical power, the line resistance of the DC bus, the line resistance of the three-phase end line and the relevant parameters.

8. A computer device, characterized in that: The computer device includes a processor and a memory, wherein the memory stores instructions, and the instructions are executed by the processor to implement the electric drive system efficiency test and compensation method according to any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that The storage medium stores instructions, and the instructions are executed by a processor of a computer device to implement the electric drive system efficiency test and compensation method according to any one of claims 1 to 6.

10. A computer program product, characterized in that The computer program product includes computer instructions, which are stored in a computer-readable storage medium; the computer instructions are read and executed by a processor of a computer device to implement the electric drive system efficiency test compensation method as described in any one of claims 1 to 6.

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