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Motor DC Motor Comprehensive Test Bench Tongliao Motor Comprehensive Test Bench



I. System Design Basis Standards:

The test items and methods for motor products comply with the following standard versions, but are not limited to the following standards.

1. GB755/IEC 60034-1 "Rotating Electrical Machines - Rating and Performance"

2. GB/T1032 "Test Methods for Three-Phase Asynchronous Motors"

3. GB/T9651 "Test Methods for Single-Phase Asynchronous Motors"

4. GB14711 "Requirements for Small and Medium-Sized Rotating Electrical Machines"

5. GB12350 "Requirements for Small Power Motors"



The DC Motor Comprehensive Test Bench Tongliao system software uses full Chinese operation, Windows XP system, with simple and convenient human-machine dialogue. The system software establishes a motor standard parameter database (the database can be stored by date, serial number, motor model, etc., and can also be set up according to user requirements). The standard database has permission management functions, accessed or modified through passwords. The system automatically records test data (three-wire detection of inter-turn, power-frequency withstand voltage to ground, and insulation resistance to ground are qualified, and the record table defaults to phase-to-phase power-frequency withstand voltage and phase-to-phase insulation resistance as qualified), determines conclusions, and saves them. It can also query in multiple ways. The software has statistical analysis and printing functions for recorded data, and can import test data into Excel spreadsheets. It can also design tables according to user requirements (adding Party A's company graphic logo). The system has strong anti-electromagnetic interference capability.

The system is simple to operate and easy to learn, with high reliability and anti-interference capability. This system is suitable for laboratories and workshops in any environment, and the system software is free to upgrade for life.

II. DC Motor Comprehensive Test Bench TongliaoTest System Features:

1. One-time wiring, press the start button once to complete all test items. Untested items can be shielded, and one or several items can be done individually.

2. Automatic data analysis, comparison, judgment, and alarm, automatic storage and printing, and print report formats according to Party A's requirements.

3. High performance with good protective measures.

4. The equipment has barcode scanning function and also has barcode or QR code printing function; hardware is optional.

5. It has the function of connecting to the factory LAN in the future; hardware is provided separately.

6. Open database interfaces and data structures to enterprises, facilitating the free use of data in the test system database by enterprise self-made software.

7. Uses a 20-inch 16:9 high-definition LCD large display screen, reducing eye fatigue for long-term viewing.

8. This equipment's relays are equipped with imported brand relays such as ABB, Schneider, Hequan, and Omron according to different functions.



III. DC Motor Comprehensive Test Bench TongliaoScope of Application: Applicable to three-phase AC asynchronous motorstators (below 200KW) factory inspection tests;

1. Resistance: 0.01-3000Ω;  

2. Two 3-meter test leads are given to Party A; these test leads are not covered by warranty. (One station has three wires, the other station has six wires.)

3. Test wiring method: 2-way wiring output test.



Remarks Test Content and Methods:

This test system can automatically test all test items such as DC resistance, insulation resistance, inter-turn insulation strength, power-frequency withstand voltage, and leakage current of the motor.

After connecting the test leads, input or select the standard parameter range for the motor model and the selected test lead serial number, press the test start button, and the system program will automatically test according to the following test items and sequence. The test sequence follows previous equipment.

1. DC Resistance

First, measure the current ambient temperature as the basis for resistance correction, then automatically select the resistance range according to the input standard parameters, measure the three line resistances of the three-phase stator winding in sequence, and calculate the resistance unbalance. All resistance values and unbalance are automatically judged as qualified or not based on the upper and lower limits in the standard parameters. If unqualified, terminate the test for that circuit, continue testing other circuits, then alarm and display; otherwise, continue the following test process.

Insulation Resistance

The test system sequentially applies DC 500V voltage between the winding of each tested machine and the housing (ground wire), measures the insulation resistance, subtracts the background, and outputs the result for display. When the measured insulation resistance value is greater than 500M, it displays 500M, and automatically judges qualification based on the standard lower limit.

Insulation resistance test: three-phase to ground

3. Inter-turn Insulation Strength

The traditional inter-turn test method for DC Motor Comprehensive Test Bench Tongliao is to run at 130% rated voltage for 3 minutes to see if the motor burns out, which is a destructive test and wastes electrical energy. Up to the mid-1980s, the high-voltage pulse surge waveform comparison method was introduced, where a standard motor and the tested motor are surged simultaneously, and two decay waveforms are displayed on an oscilloscope tube for manual comparison and judgment of waveform differences. Although this method has made great progress, long-term testing of standard motors reduces inter-turn insulation performance, and judgment results are also affected by human factors. Therefore, to improve detection accuracy and ensure test effectiveness, when designing this solution, our company combines foreign advanced technology with computer application technology, adopts a high-speed A/D test system, uses the high-voltage pulse waveform comparison method, digitizes the inter-turn waveform, and calculates several parameters of the waveform through a computer to obtain quantitative indicators of the waveform: (1) decay rate, (2) frequency, (3) integral area. The motor waveform is automatically stored in the computer for comparison and automatic judgment.

Inter-turn insulation is very important in motor testing. If missed, it can cause very serious consequences. The main reason for missed judgments is insufficient inter-turn energy. Some instruments only pursue small equipment size and low cost, using electronic voltage regulation, which cannot achieve sufficient energy storage. Additionally, to reduce costs, thyristors or IGBTs are used instead of traditional thyratrons as switching devices, and the pulse current and wavefront time are far from achieving the effect of thyratrons. Our company uses thyratrons as switching devices, with a storage capacitor of 0.1uF and output energy of 0.25J, to ensure products are not missed.

During testing, according to the sampling speed and magnification determined when making the standard waveform in advance, the adjusted inter-turn high voltage is applied to the motor winding through the thyratron, and the resulting damped oscillation waveform is sampled. Using a high-speed A/D test system, the inter-turn waveform is digitized, and several parameters of the waveform are calculated and processed by a computer to obtain quantitative indicators of the waveform: (1) decay rate, (2) frequency, (3) integral area. For three-phase motors, the inter-turn waveforms are compared using the self-comparison method, and the waveforms of the three windings are displayed overlapping on the screen. Judgment accuracy: when the number of winding turns is within 400 turns, adjacent one-turn inter-turn short circuits can be detected.