What Is an Induced Voltage Test (IVT)?
Quick answer — The induced voltage (or induced overvoltage) test applies a higher-than-rated frequency and voltage to the winding to stress the insulation between turns and between windings without over-exciting the core. It verifies the turn-to-turn and winding-to-winding insulation. It is often combined with a power-frequency or very-low-frequency (VLF) withstand test.
What is an induced voltage (overvoltage) test on a transformer?
Its purpose
It proves the insulation between turns, discs and windings is adequate, which the applied-voltage test (between windings and ground) does not fully cover.
How it is done
A higher-frequency voltage (so the flux stays in range) is applied to one winding with the other open or grounded as specified, inducing a test voltage across the winding that stresses the internal insulation.
What it catches
It catches inter-turn weak points, partial discharge and defects in the internal insulation system that could cause a winding failure in service.
References & standards
- IEC 60076-3 (dielectric tests)
- IEEE C57.12.90
Related
Related manufacturers
Prolec GE (GE Vernova) · Prolec GE Waukesha · Hitachi Energy USA · Siemens Energy · Eaton · Virginia Transformer Corp
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Technical content is prepared from engineering references, standards frameworks, manufacturer documentation and industry sources. Contractual or compliance decisions should refer to current official standards. TransformerPath Technical Editorial.
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