Yash Highvoltage® Carries Out Successful Seismic Test on Its IEEE Compliant 138 kV OIP Transformer Bushings
Updated: 2 hours ago
Yash Highvoltage Limited has successfully completed seismic qualification of its 138 kV Oil-Impregnated Paper (OIP) Condenser Transformer Bushing as per requirements of IEEE 693 & response spectrum corresponding to 0.5g seismic level. The successful testing demonstrates bushing's capability to sustain severe earthquake events.
The seismic qualification has been performed using a tri-axial shake-table test under realistic service conditions. In order to simulate the actual installation in the field, during testing the bushing was mounted on a steel structure at an angle of 30° to vertical. The test sequence included instrumentation, calibration, resonance node identification, full seismic excitation, post-test verification, and routine electrical testing before and after seismic testing.
During the testing, 33-second time-history earthquake simulation was applied simultaneously in the X, Y and Z directions across a frequency range of 0.3 Hz to 50 Hz.
Outcome & the Results
No cracking, no oil leakage, and the absence of visible damage.
No loosening, deformation, or structural damage.
Bushing successfully withstood routine electrical tests after seismic tests.
Resonance frequency shift (between before and after seismic tests) found to be well within acceptance limit of 20%.
Maximum HV terminal displacement recorded was 7.33 mm.
The exceptionally low resonance frequency shift after the seismic test confirmed the structural integrity of bushing. Routine electrical tests have been successfully carried out (after the seismic test) in line with requirements of IEEE C57.19.00/01 in our 600 kV EHV laboratory (Certified as per ISO/IEC 17025).
This successful seismic qualification demonstrates Yash Highvoltage’s commitment to delivering transformer bushings of superior quality and exceptional reliability for earthquake-prone regions, reinforcing our position as a trusted global partner for utilities, transformer manufacturers and EPC contractors.