Advanced Transformer Services

A Vital Asset

Power transformers are the most significant and vital component of the power delivery system. Their reliability and performance remain of great importance to the utilities. Irrespective of the failure rate, transformers are also of high concern from the point of asset management. Sudden failure of a large transformer may cause interruption in power supply resulting in a high repair costs, revenue losses as well as environmental and collateral damages. Many factors such as loading, ambient temperatures, over voltages and short circuits can lead to accelerated aging processes.  Proper commissioning and condition-based maintenance (CBM) are critical in optimizing the lifecycle costs of this critical asset

Potential Defects and Aging Factors


  • Cracks, contamination, and breakdown of capacitive grading layers
  • Moisture ingress
  • Capacitive tap issues
  • Breakdown and internal insulation


Current transformer:

  • Burden related issues
  • Insulation problems
  • Shorted turns

Tap changer:

  • Contact problems
  • Shorted turns or open circuits


  • Moisture and contamination
  • Deterioration of paper


  • Shorted turns and open circuits
  • Short circuit to ground
  • Mechanical deformations
  • Contact problems


  • Mechanical deformation
  • Floating core ground
  • Shorted laminates
  • Residual magnetism

Our Comprehensive list of Transformer Diagnostic Techniques

  • DC winding Resistance
  • Transformer Turns Ration(TTR)
  • Excitation Current Measurement
  • Leakage Reactance Measurements
  • Variable Frequency Capacitance & Power/Dissipation Factor (C&DF)
  • Dielectric Frequency Response(DFR)
  • Frequency Response of stray losses
  • Partial Discharge measurement and localization
  • Demagnetization
  • Sweep Frequency Response Analysis
  • Current Transformer winding resistance, burden, excitation and ratio