Power Transformer

Transformer testing

Testing of power transformers makes a couple of different measurements necessary, which are described in the international IEC 6’’76 standard.

Scope and Vector Scope offer the capability to analyze the voltage ratio and phase displacement of different primary and secondary configurations (star, delta, interconnected star).

Transient recording functionality allows storing all signals at the full sampling rate for detailed analysis. In combination with the trigger functionality failures and transient events (also during long-term measurements of the transformer) can easily be detected.

Power quality

The Power quality module allows measuring harmonics of the voltage and the current up to some hundred kHz. The data can be represented in percentage of the fundamental frequency as required for the no-load current according to IEC 6’’76 standard.

The power quality module also automatically calculates the zero-sequence impedance which is required in the power transformer testing.

The math library allows to automatically calculate parameters like the magnetizing current, the iron losses, the main inductance for example out of the no-load test or the stray inductances out of the short-circuit tests.

For more information check the power quality application page.

Power and Efficiency

Power and efficiency analysis of the transformers require the highest accuracy of the power calculation for all phase angles. Especially analysis at lower power factors is very difficult with conventional measurement equipment.

The additional sensor calibration functionality allows correcting the behavior of voltage and current transducers for amplitude and phase over the whole frequency range.

Furthermore, IEC 6’’76-1 standard requires the correction of measured power losses depending on the temperature. Dewesoft power analyzer makes it easy to measure all the required temperatures (winding, oil, ambient, etc.) perfectly synchronized to voltage, current and other measured parameters.

In addition, it’s possible to automatically calculate the corrected power losses. You can also measure the power of oil pumps and fan motors, and even the sound level of the transformer according to IEC 6’551 standard.

This covers all the possible tests that you can experience with power transformers, and Dewesoft can cover them all with one single device.