Vibro-acoustic measurements for On Load Tap Changers
Listen to what your OLTC has to say
The vibro-acoustic measurement (VAM) method focuses on the mechanical integrity of the On Load Tap Changer. The OLTC is a mechanical switching device that regulates the system voltage by adjusting the transformer turns ratio. Due to the thermal and mechanical stresses generated when switching the load current, various OLTC components such as the contacts can suffer wear and tear over their lifetime.
Therefore, the new VAM1 accessory for TESTRANO 600 records a detailed vibration pattern produced during the switching operation using piezoelectric sensors. These sensors are temporarily mounted to the power transformer tank via magnets.
The results are compared with reference data such as a fingerprint or previously recorded data. Mechanical deviations in the OLTC will lead to an altered vibration pattern and thus be detectable.
The VAM solution can be performed offline or while the power transformer is still connected to the grid.
Combined mechanical and electrical analysis
The VAM is a Primary Test Manager™ (PTM) only test
The VAM is a Primary Test Manager™ (PTM) only test. PTM is a powerful testing suite with a built-in database and analysis features. It supports you in the best possible way when you’re executing diagnostic tests via wiring diagrams and asset-specific test plans according to international standards like IEEE and IEC. PTM offers automatic result assessment, comparisons, and customized reporting for a more comprehensive analysis.
- Easy installation for sensors using magnets
- Synchronized VAM and DRM measurement
- Motor current analysis
- Can be performed both offline and online
- Applicable for resistive-and inductive-type OLTCs