Combined Vibro-Acoustic Measurement(VAM) and Dynamic Resistance Measurement(DRM) to Analyze on-Load Tap Changer(OLTC)

On-load tap changers (OLTCs) in power transformers are crucial for stable voltage levels within electrical grids. By adjusting the transformer's tap settings, OLTCs regulate voltage, enduring thermal and mechanical stress that causes wear over time. This paper explores the combined use of dynamic resistance measurement (DRM) and vibro-acoustic measurement (VAM) to diagnose OLTCs. VAM can be performed on operational transformers, providing vital condition data without downtime. This approach enhances preventive maintenance efficiency and improves the reliability of transformer systems.