Germany, Regensburg: Maschinenfabrik Reinhausen (MR) has released TAPSCAN® VAM – the new diagnostic tool for evaluating acoustic noise.
The new tool evaluates the state of the on-load tap-changer, which is responsible for regulating power transformers. Each on-load tap-changer has a specific profile which is recorded and transmitted using acceleration sensors.
The sensors are attached to suitable measuring points depending on the design of the transformer. They are attached with either screw or cap nut adapters or using an adapter glued or magnetically attached to the transformer tank.
Then, the sensors are connected to the measuring device via a measuring cable. Additionally, a self-powered current clamp is attached to the motor-drive unit to trigger the measurement.
This is used to determine when the motor is running or the OLTC is being driven and when the next tap change operation is imminent. All noises of an on-load tap-change operation are recorded and the data is evaluated using a time frequency domain analysis.
A special Software is used to compare the analysed and processed data with stored reference data from the type of tap changer measured. During the measurement process, the transformer does not have to be switched off.