Dragging test bench applied to new energy commercial vehicle electric drive system test

Abstract

The invention relates to a twin trawling test bench for testing an electric driving system of a new energy commercial vehicle, and the bench comprises a computer information system, a power analyzer, a driving system cooling liquid temperature control system, a driving motor, and a driving motor controller. The driving motor controller and the power analyzer are respectively connected with the computer information system, the driving motor is connected with the driving system cooling liquid temperature control system and comprises a bidirectional direct-current power supply and a twin-trawling rack, the driving motor comprises a tested motor and a test accompanying motor, the driving motor controller comprises a tested end controller and a test accompanying end controller, and the tested end controller is connected with the tested end controller. The tested motor and the test accompanying motor are respectively arranged on the twin-trawling rack and are connected with each other, the tested motor is connected with the tested end controller, the test accompanying motor is connected with the test accompanying end controller, the tested end controller and the test accompanying end controller are respectively connected with the bidirectional direct current power supply, the tested end controller and the test accompanying end controller are both connected to the common direct current bus, and the common direct current bus is connected with the test accompanying end controller. And feedback circulation is formed.

Description

Technical Field

[0001] The invention relates to a test bench, in particular to a towing test bench used for testing an electric drive system of a new energy commercial vehicle. Background Art

[0002] With the rapid development of the automobile industry, how to quickly and accurately test and evaluate the newly developed permanent magnet synchronous motor products for new energy vehicles has received increasing attention and attention from research institutions and manufacturers. It has become an indispensable means to complete various performance assessments of drive motors on test benches in accordance with relevant national standards. In the design process of new energy drive motors, motors and controllers must undergo multiple rounds of development tests. As a permanent magnet synchronous motor (PMSM) in the power drive system of new energy vehicles, the demand for test benches is also increasing, and the requirements are becoming higher and higher. The consumption of power resources during the test process is also very large. Summary of the invention

[0003] The technical problem to be solved by the present invention is: a towing test bench for testing an electric drive system of a new energy commercial vehicle, which is convenient for testing a permanent magnet synchronous motor of a power drive system of a new energy vehicle.

[0004] The technical solution to solve the above technical problems is: a towing test bench for testing the electric drive system of new energy commercial vehicles, including a computer information system, a power analyzer, a drive system coolant temperature control system, a drive motor and a drive motor controller, the drive motor is connected to the drive motor controller, the drive motor controller and the power analyzer are respectively connected to the computer information system, the drive motor is connected to the drive system coolant temperature control system, including a bidirectional DC power supply and a towing test bench, the drive motor includes a tested motor and a companion tested motor, the drive motor controller includes a tested end controller and a companion tested end controller, the tested motor and the companion tested motor are respectively arranged on the towing test bench and connected to each other, the tested motor is connected to the tested end controller, the companion tested motor is connected to the companion tested end controller, the tested end controller and the companion tested end controller are respectively connected to the bidirectional DC power supply, and the tested end controller and the companion tested end controller are both connected to a common DC bus.

[0005] A further technical solution of the present invention is: two drive motors and drive motor controllers can be mutually tested during the test, the tested motor and the test companion motor are coaxially connected to each other in a coaxial transmission mode, the tested end controller and the test companion end controller are both connected to a common DC bus, and energy can form a feedback loop on the DC bus during the test, and the test companion motor is controlled by controlling the test companion end controller to provide loading capacity for the tested motor, and the bidirectional DC power supply converts the AC incoming line into a continuously adjustable DC output to supply power to the common DC bus, and through the feedback loop, the bidirectional DC power supply can feed power to other power grid equipment at full power. Specifically, the tested motor and the test companion motor are connected to each other through a diaphragm coupling. The tested end controller and the test companion end controller are respectively connected to the bidirectional DC power supply through an electrical parameter measurement junction box.

[0006] The bidirectional DC power supply (battery simulator) converts the AC input line into a continuously adjustable DC output to supply power to the common DC bus. The motor under test and the accompanying motor under test share the bus during the measurement process, forming a feedback loop, reducing the power resource consumption during the test process, achieving the effect of energy saving and cost reduction, and significantly reducing the test cost. The specific method includes the following steps: A. Use a bidirectional DC power supply (bidirectional DC battery simulator) to convert the AC input line into a continuously adjustable DC current output to supply power to the public DC bus; B. Connect the motor under test and the companion motor to the common DC bus; C. Start the test, the computer information system collects the signals from the test end controller, the test motor, the motor under test, the test end controller, and the speed and torque sensor for processing; D. After the computer information system processes the data, it controls the accompanying motor to put it in output torque mode and feeding mode to complete data collection.

[0007] Test method: The motor under test is tested according to the design parameters of the accompanying motor as a reference. The motor under test and the accompanying motor are coaxially connected. The accompanying motor as the accompanying test piece applies speed or torque to the motor under test and rotates under the same conditions. The data of the motor under test and the accompanying motor under test are collected and compared by the computer information system and the power analyzer respectively. The design parameters are compared. If the parameters of the motor under test are consistent with the design parameters, it is qualified. If the design parameters between the two drive motors and the drive motor controller are consistent, it indicates that the accompanying motor under test is qualified. The method for judging whether the experimental data of the motor under test is consistent with the data of the accompanying motor under test is: the experimental data of the motor under test is the same as the data of the accompanying motor under test, or is within the conventional allowable error range. The data or parameters are voltage, current, speed, torque and power, etc.

[0008] Test method: According to the test requirements of the motor under test, the design parameters for reference are set manually, and the corresponding companion motor, the test end controller and the test end controller are used according to the set design parameters. The motor under test and the companion motor are coaxially connected and rotated under the same conditions. The data of the motor under test and the companion motor are collected and the design parameters are compared through the computer information system and the power analyzer. The parameters of the motor under test are qualified if they are consistent with the design parameters. If the design parameters between the two drive motors and the drive motor controllers are consistent, it indicates that the companion motor is qualified. The method for judging whether the experimental data of the motor under test is consistent with the data of the companion motor is: the experimental data of the motor under test is the same as the data of the companion motor, or is within the conventional allowable error range. The data or parameters are voltage, current, speed, torque and power, etc.

[0009] The towing stand comprises a base, an adapter plate, a coupling and a connecting shaft, the adapter plate, the coupling and the connecting shaft are respectively arranged on the base, the adapter plates are respectively arranged at both ends of the base, the couplings are respectively arranged at both ends of the base, the motor to be tested and the accompanying motor to be tested are respectively arranged on the adapter plates at both ends of the base, the motor to be tested and the accompanying motor to be tested are respectively connected to the couplings at both ends of the base through spline shafts, and the couplings at both ends of the base are connected through a connecting shaft.

[0010] Due to the adoption of the above technical solution, a towing test bench for testing the electric drive system of a new energy commercial vehicle according to the present invention has the following beneficial effects: 1. The present invention can carry out towing loading tests on new energy drive motors, and can also undertake single-machine testing tasks for new energy drive motors. The two drive motors can be tested with each other during the test, which can improve the test efficiency of the test bench. The controllers of the tested motor and the accompanying motor are both connected to a common DC bus. The accompanying motor is controlled by the accompanying motor controller to provide loading capacity for the tested motor. During the test, energy can form a feedback loop on the DC bus. The loss of the test equipment and the acceleration and deceleration power energy of starting and stopping are all provided by the battery simulator or power supply. The battery simulator converts the AC incoming line into a continuously adjustable DC output to supply power to the common DC bus. The battery simulator can have the function of feeding power to the power grid at full power, achieving the effect of energy saving and cost reduction.

[0011] 2. The present invention controls the two drive motors to be in output torque mode and feeding mode respectively through the control unit to test the two drive motors at the same time. It can be effectively applied to various load and no-load test scenarios of electric drive assemblies, avoiding the existing test bench using gear boxes or dynamometers, reducing the test bench investment and construction costs, and significantly reducing the test costs. The motor being tested and the accompanying motor are respectively driven by the same specification product coaxial transmission mode, and are driven by the controller matching the drive motor to solve the problem of expensive testing costs of existing electric drive systems.

[0012] Below, the technical features of a towing test bench for testing an electric drive system of a new energy commercial vehicle of the present invention will be further described in conjunction with the accompanying drawings and specific embodiments of the specification. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 : Test block diagram of the electric drive system for new energy commercial vehicles in the present invention.

[0014] Figure 2 : Schematic diagram of the structure of the towing test bench.

[0015] Figure 3 : Schematic diagram of the mounting stand structure used to place sensors and power meters.

[0016] In the above drawings, the descriptions of the reference numerals are as follows: 1-base, 2-adapter, 3-coupling, 4-spline shaft, 5-motor under test, 6-motor under test, 7-torque sensor, 8-temperature sensor, 9-speed sensor, 10-controller placement area, 11-Hall sensor placement area, 12-power analyzer placement area. DETAILED DESCRIPTION

[0017] A towing test bench for testing electric drive systems of new energy commercial vehicles includes a computer information system, a power analyzer, a drive system coolant temperature control system, a drive motor, a drive motor controller, a bidirectional DC power supply and a towing test bench. The drive motor is connected to the drive motor controller, the drive motor controller and the power analyzer are respectively connected to the computer information system, and the drive motor is connected to the drive system coolant temperature control system. The drive motor includes a motor under test and a companion motor under test, the drive motor controller includes a test end controller and a companion test end controller, the motor under test and the companion test motor are respectively arranged on the towing test bench and connected to each other, the motor under test is connected to the test end controller, the companion motor is connected to the companion test end controller, the test end controller and the companion test end controller are respectively connected to the bidirectional DC power supply, the test end controller and the companion test end controller are both connected to a common DC bus, the test end controller and the companion test end controller are respectively connected to the computer information system, and the test end controller, the companion test end controller and the computer information system are respectively connected to the power analyzer.

[0018] Specifically, the measured end controller and the accompanying measured end controller are respectively connected to the common DC bus of the bidirectional DC power supply, the measured motor and the measured end controller are connected to each other, the accompanying measured motor and the accompanying measured end controller are connected to each other, the current can flow from the bidirectional DC power supply to the measured end controller and the accompanying measured end controller, and the current can also flow from the accompanying measured motor to the bidirectional DC power supply, the bidirectional DC power supply is connected to the power grid, the power grid can supply power to the bidirectional DC power supply, and the current from the motor obtained by the bidirectional DC power supply can also feed power to other devices in the power grid, the power analyzer is respectively connected to the drive motor and the drive motor controller, and the drive system coolant temperature control system is respectively connected to the measured motor and the accompanying measured motor. The computer information system is respectively connected to the power analyzer, the drive system coolant temperature control system, the drive motor, the drive motor controller and the bidirectional DC power supply. Specifically, the measured motor and the accompanying measured motor are connected to each other through a diaphragm coupling. The measured end controller and the accompanying measured end controller are respectively connected to the bidirectional DC power supply through an electrical parameter measurement junction box. The computer information system is some existing monitoring systems, and the computer information system includes an industrial computer, a UPS power supply, a host computer and a measurement and control unit. The industrial computer is connected to the UPS power supply, the host computer is connected to the industrial computer, and the measurement and control unit is connected to the host computer. The drive motor and the drive motor controller are matching motors and motor controllers. The present invention also includes an environmental chamber, which is suitable for the needs of different environments.

[0019] The two drive motors and the drive motor controllers can be mutually tested during the test. The tested motor and the test motor are coaxially connected and tested in a coaxial transmission mode. The tested end controller and the test end controller are both connected to the common DC bus. During the test, energy can form a feedback loop on the DC bus. The test end controller controls the test motor to provide loading capacity for the tested motor. The bidirectional DC power supply converts the AC input line into a continuously adjustable DC output to supply power to the common DC bus. Through the feedback loop, the bidirectional DC power supply can feed power to other power grid equipment at full power. The towing stand includes a base, an adapter, a coupling and a connecting shaft. The adapter, the coupling and the connecting shaft are respectively arranged on the base. The adapter is respectively arranged at both ends of the base. The coupling is respectively arranged at both ends of the base. The tested motor and the test motor are respectively arranged on the adapter at both ends of the base. The tested motor and the test motor are respectively connected to the couplings at both ends of the base through spline shafts. The couplings at both ends of the base are connected through a connecting shaft. The coaxial connection of the tested motor and the test motor is realized. Coupling: Wei diaphragm coupling.

[0020] The bidirectional DC power supply (battery simulator) converts the AC input line into a continuously adjustable DC output to supply power to the common DC bus. The motor under test and the accompanying motor under test share the bus during the measurement process, forming a feedback loop, reducing the power resource consumption during the test process, achieving the effect of energy saving and cost reduction, and significantly reducing the test cost. The specific method includes the following steps: A. Use a bidirectional DC power supply (bidirectional DC battery simulator) to convert the AC input line into a continuously adjustable DC current output to supply power to the public DC bus; B. Connect the motor under test and the companion motor to the common DC bus; C. Start the test, the computer information system collects the signals from the test end controller, the test motor, the motor under test, the test end controller, and the speed and torque sensor for processing; D. After the computer information system processes the data, it controls the accompanying motor to put it in output torque mode and feeding mode, and completes data collection.

[0021] A test method for electric drive systems of new energy commercial vehicles: the motor under test is tested according to the design parameters of the accompanying motor as a reference, the motor under test and the accompanying motor are coaxially connected, that is, the motor under test and the accompanying motor are connected to each other through a diaphragm coupling, and the accompanying motor as a test companion applies a rotation speed or torque to the test companion. Rotate under the same conditions, collect and compare data of the motor under test and the accompanying motor respectively through a computer information system and a power analyzer, and compare the parameters and design parameters of the motor under test and the controller under test. If the experimental data of the motor under test is consistent with the data of the accompanying motor, it indicates that the accompanying motor is qualified. If the test parameters of the motor under test are consistent with the design parameters of the accompanying motor, the test parameters of the controller under test are consistent with the design parameters of the accompanying controller, that is, the design parameters of the two drive motors and the drive motor controller are consistent, it indicates that the accompanying motor is qualified.

[0022] Alternatively, according to the test requirements of the motor under test, design parameters for reference are manually set, and the corresponding accompanying test motor, the tested end controller and the accompanying test end controller are used according to the set design parameters. The motor under test and the accompanying test motor are coaxially connected and rotated under the same conditions. Data of the motor under test and the accompanying test motor are collected and compared through a computer information system and a power analyzer, and data of the tested end controller and the accompanying test end controller are collected and compared. The parameters of the motor under test and the tested end controller are compared with the design parameters of the accompanying test motor and the accompanying test end controller. If the test parameters of the motor under test are consistent with the design parameters of the accompanying test motor, and the test parameters of the tested end controller are consistent with the design parameters of the accompanying test end controller, that is, the design parameters of the two groups of drive motors and drive motor controllers are consistent, it indicates that the accompanying test motor is qualified.

[0023] The method for judging whether the test parameters of the motor under test are consistent with the design parameters of the accompanying motor under test is as follows: the experimental data of the motor under test is the same as the data of the accompanying motor under test, or is within the conventionally allowed error range; the experimental data of the controller under test is the same as the data of the accompanying controller under test, or is within the conventionally allowed error range. The data or parameters are voltage, current, speed, torque and power, etc.

[0024] The present invention sets two test stations for setting the power drive assembly to be tested, connects the output shafts of two power drive assemblies in four inspection stations, and controls the two power drive assemblies to be in output torque mode and feeding mode respectively by a computer information system, tests the two wheel hub power drive assemblies at the same time, collects the speed and torque data carried by the four inspection stations, and can be effectively applied to some load and no-load test scenarios of the power drive assembly, avoids the existing test bench using solutions such as gear boxes or dynamometers, reduces the test bench investment and construction costs, and can greatly reduce the test costs.

[0025] Specific embodiment: A new energy motor uses a shared busbar technology to tow test bench, including a detection unit and a control unit. The detection unit includes four test stations and a connection detection unit. The four test stations are divided into two drive motor controller test stations and two new energy permanent magnet synchronous motor test stations, that is, the accompanying test end controller, the accompanying test motor, the tested motor, and the tested end controller are four detection stations. The drive motor controller test station is arranged on both sides of the mounting table of the integrated power analyzer and the precision sensor, and the two new energy permanent magnet synchronous motor test stations are arranged in parallel and at intervals on the base of the tow bench for installing new energy permanent magnet synchronous motors. The torque and speed sensors are installed on the base and connected to the power analyzer.

[0026] The control unit consists of two drive motor controllers, which are connected to the new energy permanent magnet synchronous motor assemblies on the two workstations respectively, and are used to generate output torque signals and feed signals to the two new energy permanent magnet synchronous motor assemblies respectively, so that they are in output torque mode and feed mode respectively. The control unit is also connected to the connection detection unit signal to receive the speed and torque carried by the connection detection unit.

[0027] By setting up two test stations for setting up the new energy permanent magnet synchronous motors to be tested, and setting a connection detection part to connect the output shafts of the two new energy permanent magnet synchronous motor assemblies, the control part controls the two new energy permanent magnet synchronous motors to be in output torque mode and feeding mode respectively, so as to test the two new energy permanent magnet synchronous motors at the same time, and at the same time, the speed and torque data carried by the connection detection part can be collected, which can be effectively applied to some load and no-load test scenarios of the new energy permanent magnet synchronous motor assembly, avoiding the existing test bench using solutions such as gear boxes or dynamometers, reducing the test bench investment and construction costs, and greatly reducing the test costs.

[0028] The connection detection part is a coupling, which can be a diaphragm coupling. The coupling is equipped with a speed detection device and a torque detection device to detect the speed and torque of the coupling and output them to the control part. The coupling uses a flange coupling. The coupling and the drive motor are connected by a spline shaft. The spline has a certain gap and has a certain performance of compensating the relative offset of the two shafts (compensating the concentricity deviation of the drive motor) and shock absorption. The strength must meet the torque required for the test.

[0029] The control unit may specifically include an industrial computer, a first bus, a second bus, and a data acquisition system. The industrial computer is connected to two drive motor controllers and drive motors through the first bus and the second bus, respectively, to form output torque signals and feed signals to the two new energy permanent magnet synchronous motors, respectively, to control the operating states of the two new energy permanent magnet synchronous motors, the output torque signal includes torque information and speed information, and the feed signal includes torque information.

[0030] The DC power supply used in the test uses a DC battery simulator (bidirectional DC power supply) in which energy can flow in both directions. During the test, the battery simulator converts the AC input line into a continuously adjustable DC output to supply power to the public DC bus. The battery simulator can feed power to the grid at full power and has the capacity expansion function, and can meet the capacity expansion capacity according to the product test requirements. The motor under test and the accompanying motor under test are both connected to the public DC bus. The accompanying motor is controlled to provide loading capacity for the motor under test. During the test, energy can form a feedback loop on the DC bus. The losses of the participating equipment and the acceleration and deceleration power energy of starting and stopping are all provided by the battery simulator or power supply.

[0031] The motor under test and the accompanying motor under test both use product drivers (controllers) that match the new energy motor under test, which can meet the function of increasing the dynamometer test. Precision measuring sensors, power analyzers and necessary control power supply equipment can be integrated on the mounting bench. The towing bench used to install the motor under test and the accompanying motor under test is designed to be equal. Precision Hall sensors are set at the input and output of the motor under test for current measurement. The voltage measurement sensor and the power meter are customized and integrated into the mounting bench. The voltage can be directly connected to the power meter for measurement. The speed torque sensor is set between the motor under test and the accompanying motor under test. The speed torque sensor can be connected to the power meter. All test data are read into the computer information system of the test bench through the communication interface. The two motors can be tested by each other during the test. The motor under test and the accompanying motor under test are installed on the base platform of the towing bench. The two motors are connected through a coupling and a connecting shaft. The coupling is a flange coupling. Two permanent magnet synchronous motors are installed on the shaft.

[0032] During the test, a closed constant temperature water cooling device can also be configured, with a control accuracy of ±1°C; temperature rise and fall time: ≥±2°C / min; the coolant inlet and outlet temperature measurement range is 5~130°C, with an accuracy of ≤±1°C; single-channel coolant flow: 30L / min, two-channel total 60L / min, coolant flow measurement range: 3-30L / min, with an accuracy of ±0.2L / min measurement value. The water cooling system of the motor under test, the accompanying motor under test, and its controller should have a temperature acquisition function, and the inlet water temperature range, pressure, and flow should all be monitored. At the same time, information such as temperature, pressure, and flow can be uploaded to the host computer through the acquisition module for unified monitoring and processing.

[0033] The basic design principle of the new energy permanent magnet synchronous motor using the shared busbar technology to tow the test bench is as follows: The purpose of the design of the durability test of the new energy permanent magnet synchronous motor is to verify its life in actual use through an accelerated model. This embodiment is designed for durability testing. Two samples (i.e., two new energy permanent magnet synchronous motor assemblies) are placed in the connection detection unit respectively, and the required test conditions are set. The output shafts relative to the two samples are connected by a flange coupling and a spline shaft. Therefore, at the same time, one sample runs in motor mode (i.e., output torque mode) and the other runs in generator mode (i.e., feed mode). During the test, the switching of the motor mode and generator mode of the test sample can be realized by industrial computer software control. When conducting the test, whether it is running in generator mode or motor mode, the key to detecting the life of the motor is to see the reliability of the mechanical structure of the new energy permanent magnet synchronous motor during operation and the durability of the insulation (current condition). During the operation of the two opposing motors, the effect of nearly equal and opposite torques on the mechanical structure and the effect of heat generation caused by currents of similar magnitude on the insulation can ensure the effectiveness of the endurance test of the towing bench using this example.

[0034] The present invention utilizes a common busbar technology to drag test method, which is applied to the common busbar technology to drag test. The test bench of the present invention mainly performs a new energy drive motor to drag loading test, and can also undertake the new energy drive motor single machine test task. The tested motor and the accompanying test motor respectively adopt the coaxial transmission mode of the same specification product, and are driven by the controller matched with the motor to solve the problem of expensive testing cost of the existing electric drive system. The two new energy drive motors and controllers can be tested with each other during the test, which can improve the test bench test efficiency. The controllers of the tested motor and the accompanying test motor are both connected to the common DC bus. The accompanying test motor controller is controlled to control the accompanying test motor to provide loading capacity for the tested motor. During the test, energy can form a feedback loop on the DC bus, and the loss of the test equipment and the acceleration and deceleration power energy of the start and stop are all provided by the battery simulator or power supply. The battery simulator converts the AC incoming line into a continuously adjustable DC output to power the common DC bus. The battery simulator has the function of feeding power to the power grid at full power, achieving the effect of energy saving and cost reduction. The copper nose connection mode is adopted for the controller to the controller installation bench and the new energy motor cable connection.

Claims

1. A towing test bench for testing electric drive systems of new energy commercial vehicles, comprising a computer information system, a power analyzer, a drive system coolant temperature control system, a drive motor and a drive motor controller, wherein the drive motor is connected to the drive motor controller, the drive motor controller and the power analyzer are respectively connected to the computer information system, and the drive motor is connected to the drive system coolant temperature control system, characterized in that: It includes a bidirectional DC power supply and a towing stand, the driving motor includes a measured motor and a companion measured motor, the driving motor controller includes a measured end controller and a companion measured end controller, the measured motor and the companion measured motor are respectively arranged on the towing stand and connected to each other, the measured motor is connected to the measured end controller, the companion measured motor is connected to the companion measured end controller, the measured end controller and the companion measured end controller are respectively connected to the bidirectional DC power supply, and the measured end controller and the companion measured end controller are both connected to a common DC bus.

2. According to claim 1, a towing test bench for testing the electric drive system of a new energy commercial vehicle is characterized by: The two drive motors and the drive motor controllers can be tested with each other during the test. The tested motor and the test motor are coaxially connected and tested with each other in a coaxial transmission mode. Both the tested end controller and the test end controller are connected to a common DC bus. During the test, energy can form a feedback loop on the DC bus. The test end controller controls the test motor to provide loading capacity for the tested motor. The bidirectional DC power supply converts the AC input line into a continuously adjustable DC output to supply power to the common DC bus. Through the feedback loop, the bidirectional DC power supply can feed power to other power grid equipment at full power.

3. According to claim 1, a towing test bench for testing the electric drive system of a new energy commercial vehicle is characterized in that: The bidirectional DC power supply converts the AC input line into a continuously adjustable DC output to supply power to the common DC bus. The motor under test and the accompanying motor under test share the bus during the measurement process to form a feedback loop. The specific method includes the following steps: A. Use a bidirectional DC power supply to convert the AC input line into a continuously adjustable DC current output to supply power to the public DC bus; B. Connect the motor under test and the companion motor to the common DC bus; C. Start the test, the computer information system collects the signals from the test end controller, the test motor, the motor under test, the test end controller, and the speed and torque sensor for processing; D. After the computer information system processes the data, it controls the accompanying motor to put it in output torque mode and feeding mode to complete data collection.

4. According to claim 1, a towing test bench for testing the electric drive system of a new energy commercial vehicle is characterized in that: Test method: The motor under test is tested according to the parameters of the companion motor as the reference design parameters. The motor under test and the companion motor are coaxially connected and rotated under the same conditions. The computer information system and power analyzer are used to collect data from the motor under test and the companion motor respectively and compare the design parameters. The motor under test is qualified if the parameters are consistent with the design parameters.

5. According to claim 1, a towing test bench for testing the electric drive system of a new energy commercial vehicle is characterized in that: Test method: According to the test requirements of the motor under test, artificially set the design parameters for reference, and use the corresponding companion test motor, test end controller and companion test end controller according to the set design parameters. The motor under test and the companion test motor are coaxially connected and rotated under the same conditions. The data of the motor under test and the companion test motor are collected and compared respectively through the computer information system and power analyzer. The motor under test is qualified if the parameters are consistent with the design parameters.

6. According to claim 1, a towing test bench for testing the electric drive system of a new energy commercial vehicle is characterized by: The towing stand comprises a base, an adapter plate, a coupling and a connecting shaft, the adapter plate, the coupling and the connecting shaft are respectively arranged on the base, the adapter plates are respectively arranged at both ends of the base, the couplings are respectively arranged at both ends of the base, the motor to be tested and the accompanying motor to be tested are respectively arranged on the adapter plates at both ends of the base, the motor to be tested and the accompanying motor to be tested are respectively connected to the couplings at both ends of the base through spline shafts, and the couplings at both ends of the base are connected through a connecting shaft.

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