1、 Introduction: The DC motor testing system consists of a dynamometer, a dynamometer controller, electrical parameter measurement, a test power supply, an operating table and electrical cabinet, a dynamometer stand, fixtures, a computer, and specialized testing software. It can arbitrarily change the load of the tested motor and directly measure the input voltage, current, power and output torque, speed, output power and efficiency of the motor under no-load, load and locked rotor conditions, as well as the input voltage, current, power and efficiency of the controller.
2、 Test parameters
a) Input voltage, current, and power of the controller
b) Input voltage, current, and power of the motor
c) Output voltage, current, and power of the motor
d) Efficiency of controller, efficiency of motor, and overall efficiency of the machine
3、 Main features of the system
1. Sampling time can be set
2. Range and number of teeth setting: Users set the corresponding torque range and speed of the dynamometer according to the number of teeth on the gear plate or photoelectric encoder.
3. Hub function: When configuring multiple (≥ 2) dynamometers, the hub automatically switches corresponding signals to avoid operational errors and safety caused by frequent plugging and unplugging of signal ports during dynamometer station replacement.
4. 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 achieve the entire process of dynamometer calibration on the computer. The calibration process is clear, and calibration data can be stored on the computer. Calibration data tables can be automatically generated and printed out.
5. Durability function: According to the requirements of the tested motor, the number of cycles, duration of each time period, load size (including no-load, light load, rated load, overload, locked rotor, stop, etc.), and durability conditions such as forward/reverse rotation can be set arbitrarily, and the set durability curve and the actual operating durability curve can be automatically displayed.
6. Load 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.
7. Synchronous sampling of motor operation input and output parameters: input voltage, current, power, power factor, frequency and output torque, speed, input power, efficiency. Having synchronous sampling during measurement ensures data consistency.
8. T-n characteristic testing function: For asynchronous motors, T-n characteristic testing is of great significance. On the T-n curve, the maximum, minimum torque, and highest efficiency points of the motor can be tested.
9. 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.
10. Curve drawing and fitting function: The system can meet the testing requirements of users for various motors and test projects, and draw various parameter characteristic original curves, fit curves, and automatically generate no-load point parameters (current, speed), maximum torque point parameters (voltage, current, speed, efficiency, output power), maximum efficiency point parameters (speed, torque, current, output power), and maximum output power point parameters (speed, torque, current, output power).
11. Report and query function: Multiple curves can be drawn in the same coordinate to meet customers' analysis of product consistency and repeatability.
12. The system has a complete self checking function, which is particularly suitable for customers to quickly diagnose and maintain on site.
(3) Self check of each module unit (or instrument): By opening the software, users can automatically enter the self check function and perform self checks on each instrument and unit in sequence.
13. The system has strong anti-interference ability: the system adopts a multi-level and rich electromagnetic compatibility design, which is particularly suitable for harsh on-site environments.
14. System accuracy consistency and repeatability: The repeatability of the dynamometer system accuracy is the most important indicator for measuring the accuracy of the entire system. Without repeatability, accuracy is meaningless.
15. Out of step point testing and maximum torque point capture function: Many motors require automatic testing of out of step point parameters or maximum torque point testing at different speeds, and automatic generation of characteristic curves of out of step torque or maximum torque versus speed (frequency).
4. Automatic slope loading 5. Durability test 6. Out of step point test (optional)
The dynamometer controller is used in conjunction with various types of dynamometers, torque and speed sensors, tension and compression sensors, etc. The instrument adopts a new core with high-speed, assembly line, and advanced simplified instruction set structure, with a running speed of 10MIPS, and is equipped with an integrated high-speed digital filter A/D for sampling.
| Test function |
Measure/Set Parameters |
Remarks |
| no-load test |
No load speed (n), no load torque (M), no load output power (P) |
|
| Manual excitation loading test |
Load speed (n), load torque (M) Load output power (P), excitation current value (I) |
| Automatic slope loading test |
Load speed (n), load torque (M), load output power (P) Excitation current value (I), automatic slope loading full offset (AEC_S) Automatic slope loading time (AEC_T) |
| Constant speed test |
Load speed (n), load torque (M), load output power (P) Speed fixed-point value setting (SET-N) Fixed point coefficients (proportional P, integral I, differential D) |
Set circuit control coefficients for different motors |
| Fixed torque test |
Load speed (n), load torque (M), load output power (P) Speed fixed-point value setting (SET_S) Fixed point coefficients (proportional P, integral I, differential D) |
| durability test |
Load speed (n), load torque (M), load output power (P) Durability frequency (Num), durability alarm lower limit (ALARM_S) |
Specially made according to the requirements of the motor |
| Out of step testing |
Load speed (n), load torque (M), load output power (P) Out of step value, automatic slope loading time (AEC_T) Automatic slope loading full offset (AEC_S), |
Specially made according to the requirements of the motor |
Equipped with RS232 interface, it can form an automatic testing system with a computer
By utilizing speed feedback (PID regulation), the excitation current of the dynamometer is controlled to achieve stable operation of the asynchronous motor in the unstable region, solving the problem of testing the characteristics of asynchronous motors in the unstable region.