Anna University of Technology Tirunelveli 2010 B.E Electrical and Electronics Engineering Ee 1402- high voltage engineering - Question Paper

PART A-(10*2=20marks)

1. elaborate the kinds of power voltages arising in power system?
2. elaborate called as switching surges?
3. Mention a few of the solid dielectrics?
4. What is Towensend's discharge?
5. Mention the specifications ofthe impulse voltages as per Indian standards?
6. describe chopped impulse voltage?
7. What is the capacitance voltage transformer?
8. State the advantages of generating voltmeters?
9. describe Insulation co-ordination?
10.Define Creepage distance in high voltage insulators?

PART B-(5*16=80marks)

11. (a) (i)Explain the mechanism of lighting strokes.(10)
(ii)Cloud discharges 14 coulombs within two ms on to a transmission line during lighting
Estimate the voltage produced at the point of stroke on transmission line.Assume the
surge impedance of the line is 350 ohm.(6)
or
(b) (i)Discuss the various methods of controlling switching over voltages.(8)
(ii)Explain the operation of explusion kind lighting arresters.(8)

12. (a)Explain different theories of breakdown in liquid dielectrics.(16)
or
(b) (i)Discuss Meek's theory of breakdown in gases under non-uniform fields.
(ii)Explain thermal breakdown in solid dielectrics.(8)

13. (a) (i)Develop the circuit of a modern multistage impulse voltage generator and discuss its
operation.(8)
(ii)How high high frequency high voltage is generated in test laboratories.(8)
or
(i)Explain the generation of high DC voltages using n-stage Cockroft-walton circuit(10)
(ii)Explain the significance of controlled tripping of impulse generators.(6)

14. (a) (i)Describe the generating voltmeter method for measuring high DC voltages.(8)
(ii)Discuss the function of CRO for impulse and high frequency measurements in high voltage
Test circuits.(8)
or
(b) (i)Explain the operation of the hall effect generator for measuring high DC currents.(8)
(ii)Discuss the effect of humidity and dust particles on the voltage measurement using
Sphere gaps.(8)

15. (a) (i)With neat sketch discuss the impulse testing of power transformer.(10)
(ii)Explain theneed for high voltage testing of electrical apparatus.(6)
or
(b) (i)Describe synthetic theory of circuit breakers.(8)
(ii)Describe operating duty cycle test on surge diverters.(8)

Earning:   Approval pending.