ETP-4 power transformer testing
Transformer Short Circuit Impedance Measurement Unit
The measurement equipment ETP-4 is a unit that automatically performs measurements in all type of power, distribution, or instruments transformers.
The measurement equipment ETP-4 is a unit that automatically performs the following measurements in all type of power, distribution, or instruments transformers:
- Short circuit Impedance measurement.
- Short circuit current at the test voltage.
- Short circuit power loss.
The unit performs the test in a fully automatic way. The test voltage is generated through a motor driven “variac”. This assures the repeatability of the successive tests in terms of the voltage application mode and avoids undesired risks due to sudden transients.
- The software program guides the correct connection of the test cables on the primary winding and the short circuits that must be done in the secondary (or tertiary) side, according with the specific connection group the transformer under test has.
- The software program recommends the tap changer positions that should be tested according with the maximum regulation % and the nominal tap.
- Displays and records the current and voltage waveform. This improves the diagnostic capability for further analysis.
From the information supplied by this test unit it is possible to have an idea about the physical integrity of the transformer under test. The typical problems that are easily detected with this unit are the following:
- Physical displacement of the transformer windings, due to electromagnetic efforts.
- Problems in the iron core.
- Transport damages.
- Fixation elements which may be broken.
The program obtains from the measured values the components of the impedance triangle in short circuit. From this information, and its evolution in time it is possible to determine which part of the transformer is being deteriorated.
The test also confirms any incipient problem, which may have been detected with other test equipment that make up the ETP system.
The following types of voltage transformers can be tested with the ETP-4, despite the size and power:
- Power Transformers (single or three phase).
- Distribution Transformers (single or three phase).
- Power Autotranformers (single or three phase)
- Instrument Voltage Transformers.