On-site Diagnostic Testing of HV / EHV class of Transformers:
Our experience spans across power transformers of all voltage class upto 1200 kV and rating upto 500 MVA.
Voltage Ratio and Vector group confirmation test,
Frequency Response Analysis (FRA),
No-load excitation current measurement
Capacitance and dissipation factor measurement of the inner insulation
Capacitance and dissipation factor measurement of high-voltage bushings
Impedance measurements (short-circuit impedance, zero sequence impedance, FRSL method)
Analysis of winding damages with the FRA method
Moisture analysis of paper insulation by dielectric method (PDC+ FDS).
OLTC operation and dynamic contact resistance measurement
Winding Resistance Measurement
Thermography , Noise , Vibration Measurement
Routine Oil test, DGA, Furan
DP test of paper insulation.
On line & Off line Partial discharge measurements of transformers
CURRENT TRANSFORMERS
On-site Testing of the HV/EHV class of Current Transformers
It is intended to perform automatic testing by CT Analyser on-site for utilities with very less testing time or by Primary injection test. The following tests can be performed:
Burden & CT winding resistance measurement
CT excitation characteristics according to IEC 60044-1, IEC 60044-6 (TPS, TPX, TPY) and IEEE C57.13. for knee-point voltages (up to 15 kV).
CT ratio & phase angle error measurement
CT phase and polarity measurement
Determination of accuracy limiting factor, instrument security factor,
Test of CTs for knee-point voltages (up to 15 kV).
Capacitance and dissipation factor measurement of the inner insulation
Capacitance and dissipation factor measurement of high-voltage bushings
Moisture analysis of paper insulation dielectric method (PDC+ FDS)
DGA test of oil.
On line & Off line Partial discharge measurements of CT.
CVT & PT
On-site Testing of the HV/EHV class of Potential Transformers and CVTs
Capacitance and dissipation factor measurement
Primary injection & Ratio test.
Moisture analysis of paper insulation by dielectric method (PDC+ FDS).
IR value with Polarization Index (PI) & Absorption Index (AI),
DC Resistance measurement On line & Off line Partial discharge measurements.