High Voltage Engineering — Winter 2018

What is treeing and tracking? Explain in concern with solid breakdown.

Draw layout of typical high voltage laboratory. Enlist equipments with typical specifications.

Explain high voltage schering bridge for measurement of capacitance and tan δ of insulators.

Enlist methods of controlled tripping of impulse generator. Explain any one method in detail.

Explain with neat diagram the principle of operation of a Generating Voltmeter. Discuss its advantages and limitations for high voltage measurements.

What is CVT? Explain with phasor diagram how a tuned CVT can be used for voltage measurements in power system.

Explain how a sphere gap can be used to measure impulse voltage? What are the parameters and factors that influence such measurements?

Explain charge simulation method for solving field problems and estimation of potential distribution.

Explain various theories of breakdown in commercial liquid dielectrics.

Explain purification & breakdown tests for liquid dielectric or transformer oil.

Explain the Streamer theory of breakdown in air at atmospheric pressure.

Define and derive Townsend's first ionization coefficient. How is the condition of breakdown obtained in a Townsend discharge?

What is non-destructive testing of insulating materials? Give very briefly the characteristics of these methods.

Explain insulation coordination. How protective devices are chosen for optimum insulation level?

Explain: Charge formation in clouds

Explain the working of Cockcroft-Walton circuit with schematic diagram.

Explain briefly the different electrical tests carried out on isolators and circuits breakers.