1. The testing capabilities and related requirements required by this experimental system are shown in Table 1.

Table 1 Test Capability and Related Requirements

2. Explanation:

2.1 The maximum power of the tested motor is related to the power capacity, and the maximum power is a parameter that all rated voltages of the tested motor should meet.

2.2 The tested motor with a rated voltage of multiple voltages should be connected to a voltage close to 380V for testing in principle.

2.3 The test method adopts the direct load method (drag), with the vast majority using torque and speed sensors to implement the B method specified in GB/T1032-2012. The efficiency of single-phase asynchronous motors below 0.75 kW is determined using the A method.

The input of the experimental system is a customer provided frequency converter with a power factor of 37KW/18.5KW and other requirements for the power supply.

2.4.1 The harmonic pollution of the test system on the power grid shall comply with the relevant national standards.

2.4.2. The system can drive the motor to run and also quickly brake and stop the motor. The test motor shutdown time meets the requirements for shutdown time during temperature rise testing.

2.4.3. The system can achieve smooth and adjustable automatic or manual loading of the tested motor during the drag test.

2.4.4. The system should have comprehensive protection functions, providing at least overvoltage, overload (overcurrent), and overheating protection, etc; When a serious malfunction occurs, the system will automatically shut down with sound and light alarms, display the fault point, and can be recorded and saved for future reference.

1. Manual control

In order to ensure the completion of certain new special test projects and to ensure that the computer system does not have a significant impact on the test progress in the event of short-term unrecoverable faults, the bidder must provide complete manual operation control functions (control and measurement of the computer can be completed by manually reading the test items when it is not running), and the operator can complete the test through the switches, buttons, and adjustment devices on the control console.

2. Automatic control

2.1 To ensure the safety of the experiment, power switches, output voltage conversion switches, etc. are not automatic and are operated manually through buttons or buttons designed on the computer.

2.2 After inputting the rated parameters of the tested motor, select the test item. The system can be controlled by computer and PLC to automatically complete the entire process of the test item with the participation of manual labor according to the initial set test item and test plan.

3. The operation control system must have an emergency stop (power button) function.

Realize the collection, analysis, processing, display, printing of test reports, data storage, and partial control functions of experimental data through computer software. The entire testing system consists of an industrial computer, range gear switching device, sensors, signal conditioning module, hardware for data acquisition and measurement instruments, measurement software, and other components.

1. The data measurement system adopts two display modes: computer automatic acquisition and instrument display.

2. Automatically collect experimental data on input and output three-phase voltage, three-phase current, phase power, power factor, total power, total power factor, frequency, speed, torque, etc; Automatically save and process data; Draw curves and automatically generate printed test reports; Establish a test database and product quality statistics table, and the query method should be convenient and fast.

3. The test report can be automatically generated during the testing process or manually inputted, and its format is agreed upon by both parties. The report should be prepared using the most convenient computer language currently available, which is easy for manual operation, including manual participation functions such as adjusting certain data.

4. The accuracy of the measuring instrument should meet the electrical testing requirements of the standard for power frequency, variable frequency three-phase motors, and traction machines.

5. The system uncertainty is not less than 0.5%.

6. The accuracy of the torque speed sensor is 0.2 level, requiring high dynamic stability.

7. The measurement of input power (three-phase voltage, current, power, etc.) is carried out using a 0.5 level three-phase electrical parameter tester with an accuracy of 0.5 level. The measurement of output power (three-phase voltage, current, power, etc.) adopts a 0.2 level three-phase electrical parameter tester with an accuracy of 0.2 level.

8. The measurement system and control system must be equipped with backup software CDs.

9. Sampling time: Set the sampling time arbitrarily (20ms~1000ms) to meet the high-speed measurement needs of users.

10. Range and number of teeth setting: Users set the range and number of teeth on the gear plate or photoelectric encoder based on the torque range and speed of the dynamometer itself.

11. Hub function (station number selection): When configuring multiple (≥ 2) dynamometers, users can choose the VG2218C-JXQ type 8-way hub, which can be operated by computer software or VG2218C to select the specified dynamometer (or station). The hub automatically switches the corresponding signal, avoiding operational errors and safety caused by frequent plugging and unplugging of signal ports when changing dynamometer positions.

12. Automatic calibration and calibration function: In addition to retaining manual calibration (including positive full-scale, negative full-scale, and zero adjustment) functions, users can automatically calibrate the entire process of the dynamometer on the computer. The calibration process is clear, and the calibration data can be stored on the computer. The calibration data table can be automatically generated and printed out.

13. Load loading modes of dynamometer: excitation mode, constant torque mode, constant speed mode, constant current mode; The PID function ensures fast dynamic response and more stable operation of the load.

14. Synchronous sampling of input and output parameters for motor operation: input voltage, current, power, power factor, frequency and output torque, speed, input power, efficiency. Having synchronous sampling during measurement ensures data consistency.

15. Dynamometer loading method: In addition to the traditional manual excitation loading method, this system has multiple automatic loading methods: constant excitation incremental loading method, constant torque incremental loading method, constant speed incremental loading method, constant torque loading method, constant speed loading method, and constant slope loading method.

16. The powerful system function self-test and rapid on-site fault diagnosis capability are important indicators that the new generation of high-performance dynamometer systems must possess. Our company has carefully launched a portable dynamometer signal detection tool, which can detect the input and output signal size of various module units (such as sensors, acquisition boards, dynamometer controllers, etc.) of the dynamometer system on site, quickly identify the fault source (fault point), and greatly improve the system's service capability and efficiency.

17. Unique anti-interference and reliability design: The application of multi-level electromagnetic compatibility (EMC) technology (such as grounding, shielding, isolation, filtering, etc.) and the guarantee of good manufacturing processes. Ensure the reliability and anti-interference ability of the system, and the system can operate stably and reliably in environments with interference, sparks, high frequency, high voltage, and strong electrical shocks. Especially in the current environment, there is radiation from high-frequency power electronic devices, which is particularly necessary.

18. The new generation of high-quality dynamometer systems focuses on current motor energy efficiency certification and high-precision testing, and therefore is committed to the overall accuracy consistency of the system. Research on measurement repeatability is an important aspect of dynamometer systems. According to the characteristics of the usage scenario of the dynamometer system (the workplace is not equipped with air conditioning, and the ambient temperature cannot be guaranteed), it is necessary to improve the working temperature range of all module units and instruments in the dynamometer system under measurement accuracy (considering 0 ℃~50 ℃), and solve the problem that is easily overlooked by users in terms of ambient temperature (i.e. poor efficiency measurement repeatability in summer and winter).