Massive catastrophic failure of an high voltage transformer

Massive catastrophic failure of an HV transformer

HIGH VOLTAGE TRANSFORMERS

A high voltage transformer is a kind of transformer operating at a high voltage level. This transformer is designed to use in high voltage labs with the aim of testing.
It has to withstand surges and transient voltages during its normal operation when the insulation under test breaks down. In order to withstand this impulse voltage, its insulation must be carefully designed. It is a usually single-phase core-type transformer.

This type of transformer is generally immersed in oil. Bakelite sheets are used for separating low-tension and high-tension windings. The high voltage transformers which are used for HV cable testing also are required to supply sufficient electric current.

In electrical engineering, a transformer is a passive component that transfers electrical energy from one electrical circuit to another circuit, or multiple circuits. A varying current in any coil of the transformer produces a varying magnetic flux in the transformer's core, which induces a varying electromotive force (EMF) across any other coils wound around the same core. Electrical energy can be transferred between separate coils without a metallic (conductive) connection between the two circuits. Faraday's law of induction, discovered in 1831, describes the induced voltage effect in any coil due to a changing magnetic flux encircled by the coil.