High Voltage Engineering (EX-702 (C)) - Important Questions

Explain the concept of High Voltage (HV) technology, its significance and necessity in modern power systems including high DC voltage, and the voltage levels classified under HV, EHV and UHV.

Explain the advantages and limitations of transmitting electrical power at high transmission voltages.

Explain Townsend's primary (first) and secondary (second) ionization processes in gaseous dielectrics and how they lead to gas breakdown.

What is meant by the intrinsic strength of a solid dielectric and by what mechanisms does breakdown occur in solid dielectrics in practice, including electronic breakdown?

State and derive Paschen's law. Discuss the significance of the Paschen minimum and its practical implications for high voltage equipment design.

Explain the construction and working of the Cockcroft-Walton voltage multiplier circuit for generation of high DC voltages, including its advantages and limitations.

Explain the triggering of an impulse generator using a trigatron (three-electrode) gap, its functions, and why triggering is required and preferred.

What is the analysis of single stage impulse generator? Derive the expression for output impulse voltage.

Explain the principle, construction and operation of the standard sphere gap for measurement of peak high AC, DC and impulse voltages and the factors influencing the measurement.

Discuss the working principle and compare the advantages, disadvantages and performance of resistance, capacitance, and mixed R-C potential dividers for impulse voltage measurement.

Describe the construction and principle of operation of the generating voltmeter for measuring high DC voltages with a suitable diagram, including its applications and limitations.

Explain the operation of electrostatic voltmeter with neat sketch, its principle, construction and limitations.

Describe the tests conducted on high-voltage insulators including flash-over voltage, mechanical strength and puncture voltage tests.

What is a circuit breaker? Describe the short-circuit test and dielectric test performed on circuit breakers and their objectives.

Write short notes on any two of the following: (i) Testing of cables and isolators (ii) High voltage tests on transformers (iii) Tests on circuit breakers and insulators.