What is Transformer Testing ?

What is Transformer Testing ?

Transformer test definition

Transformer testing involves various procedures to confirm the specifications and performance of the transformer before and after installation.

Transformer test type

• Type test

• Routine inspection
  

• Special test

Transformer type test

In order to prove that the transformer meets the customer's specifications and design expectations, the transformer must undergo different test procedures at the manufacturer's site. Some transformer tests are performed to confirm the basic design expectations of the transformer. These tests are carried out primarily in prototype units rather than in batches across all manufacturing units. The type test of the transformer confirmed the main and basic design criteria of the production lot.

Transformer type test type

• Transformer winding resistance test

• Transformer ratio test

• Transformer vector group test

• Measurement of impedance voltage/short-circuit impedance (main tap) and load loss (short-circuit test)

• Measurement of no-load loss and current (open circuit test)

• Measurement of insulation resistance

• Dielectric testing of transformers

• Transformer temperature rise test

• Test of on-load tap-changer

• Vacuum testing of tanks and radiators

Routine testing of transformers

Routine testing of transformers is mainly used to confirm the operational performance of individual units in a production batch. Routine testing is performed on each unit manufactured.

Conventional test types for transformers

• Transformer winding resistance test

• Transformer ratio test

• Transformer vector group test

• Impedance voltage/short-circuit impedance (main tap) and load loss measurement (short-circuit test)

• Measurement of no-load loss and current (open circuit test)

• Measurement of insulation resistance

• Dielectric testing of transformers

• Test on an on-load tap-changer.

• Perform an oil pressure test on the transformer to check for leaks in joints and gaskets

Special testing of transformers

Perform special tests on transformers according to customer requirements, providing valuable information for operation and maintenance.

Special test types for transformers

• Dielectric test

• Measurement of zero sequence impedance of three-phase transformer

• Short-circuit test

• Acoustic Measurement of noise levels

• Measurement of no-load current harmonics

• Measure the power consumed by the fan and oil pump

• Test purchased components/accessories such as buchhloz relays, temperature indicators, pressure relief devices, oil retention systems, etc

Sum up

Transformer testing is an important means to ensure the safe operation of transformers, including type test, routine test and special test. The specific test items include variable ratio test, winding resistance test, short circuit impedance test, on-load tap-changer test, no-load test, dielectric loss test, sweep frequency response analysis, etc. In addition, there are insulation testing, coil on-off detection, no-load current and voltage detection, temperature rise test. Through these tests, the performance and status of the transformer can be comprehensively understood, potential problems can be discovered and dealt with in time, and the safe and stable operation of the transformer can be ensured.