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.

Describe the major applications of High Voltage (HV) technology in electrical and industrial fields. Highlight both power and non-power applications.

What is the need for generating high voltages in a laboratory environment? Describe different purposes and testing scenarios where HV generation is essential.

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?

Explain the phenomenon of corona discharge and breakdown Mechanism in non-uniform fields.

Explain the breakdown mechanism of liquid dielectrics.

Describe the streamer mechanism of breakdown in non-uniform fields. How does it improve upon the Townsend theory in explaining practical gaseous breakdown?

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

How does a breakdown voltage discharge happen in a deep vacuum? What makes arcing inside it?

Define Townsend's first and second ionization coefficients. How is the condition for breakdown obtained in a Townsend discharge?

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.

Briefly describe Tesla coil, voltage doubler circuit, and generation of switching impulse voltage.

Explain the cascaded connection of transformer for producing very high AC voltages.

Explain the principle of operation of a series resonant circuit used in high voltage testing. Derive the condition for resonance.

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

Explain why the high frequency and high voltage produced by a Tesla coil allow current to flow in nearby objects.

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 methods and instruments used for surge current measurement and challenges in high-voltage systems.

Write short notes on power transformer, electrostatic voltmeter, Tesla coil, and statistical and formative time lags in electrical breakdown.

Explain the operation of electrostatic voltmeter with neat sketch.

Explain the conditions to be satisfied by a potential divider for use in impulse work.

Explain surge current measurement, cavity breakdown and Paschen's law.

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

Describe short-circuit and dielectric tests performed on circuit breakers and their objectives.

Write short notes on testing of cable isolators and testing of circuit breakers.

Explain the different electrical tests performed on isolators and circuit breakers.

Explain partial discharge testing of high-voltage cables and location of insulation faults.

Difference between high voltage (dielectric withstand) test and insulation resistance test for insulation assessment.

What is high voltage test? Why do transformers have high voltage tests?

How many pouring methods are there for a motor coil insulating paint?