What are the dry transformer tests?

For this common power equipment dry transformer, once failure occurs, the consequences are very serious. Therefore, before delivery, it is necessary to carry out various tests to detect hidden defects and confirm whether the technical indicators meet the requirements of the specification, which ensures that the equipment can continue to work stably under normal operation. For transformers in operation, it is also necessary to carry out regular inspection tests to evaluate the performance and status of the equipment, and make necessary repairs.

dry-type-transformer

Dry transformer test items are:

‌Routine test items:

‌Basic parameter measurement: Including transformer rated capacity, rated voltage, rated current, impedance, no-load current, short-circuit impedance measurement‌.

‌Insulation resistance test: Including the measurement of the insulation resistance between the windings, the insulation resistance between the winding and the ground‌.

‌Winding resistance test: Including low and high voltage side winding DC resistance measurement‌.

‌On-load loss and no-load loss test: Including measurement and calculation of on-load loss and no-load loss of transformer ‌.

‌Noise test: Includes measurement of the noise level of the transformer under rated load ‌.

‌Temperature rise test: Including the temperature rise test of the transformer under the rated load to detect the heat dissipation performance of the transformer ‌.

‌Short-circuit test: Including short-circuit voltage test, short-circuit current test ‌.

‌Winding steering test: Test whether the steering of the transformer winding is correct ‌.

‌Protection device test: Test whether the protection device of the transformer is normal ‌.

‌Voltage test: Test whether the insulation strength of the transformer meets the requirements ‌.

dry-type-transformer

‌Special test project:

Sound level determination: Measure the noise level of the transformer ‌.

Short-circuit bearing capacity test: Test the bearing capacity of the transformer under short-circuit condition ‌.

Environmental test: Simulate transformer performance under different environmental conditions ‌.

Climatic test: Test transformer operation in different climatic conditions ‌.

Combustion performance test: Test the fire resistance of the transformer ‌.

‌Test methods and equipment:

‌Winding DC resistance measurement: Use double-arm bridge or transformer DC resistance testing instrument to measure. Pay attention to the position of the voltage and current end of the clamp to avoid unnecessary measurement error ‌.

‌Insulation resistance and absorption ratio measurement: Use 2500V insulation resistance tester to record the temperature of the transformer body and convert the temperature to ensure the accuracy of the measurement results ‌.

When conducting these tests, the relevant test procedures and standards should be strictly followed to ensure the accuracy and reliability of the test results. At the same time, attention should also be paid to safety matters during the test to avoid accidents.

Purpose of transformer test

1. Verify that the device complies with the specifications

When designing and manufacturing transformers, various domestic and foreign standards and regulations need to be followed to ensure the quality and safety performance of the equipment. The test can verify whether the equipment meets the requirements of the specification to ensure the performance and service life of the equipment.

2. Detect hidden defects

In the production and transportation process, there will inevitably be some hidden defects, such as poor contact, insulation material damage and so on. These hidden defects can be found effectively through the test and dealt with in time to avoid major accidents in the operation of the equipment.

3. Evaluate the life of the equipment

Through a series of tests, the service life of the equipment can be evaluated to determine its replacement or maintenance time, which ensures the safe and stable operation of the equipment.

4. Improve device performance

Adjustment and improvement of technical parameters, such as phase difference and load loss, are carried out through tests to improve the performance and efficiency of the equipment.