UNIT VI

Busbar Protection, Transmission Line Protection

Q1) Explain differential protection scheme in case of busbar.

Q2) Explain correct method of selection of CT ratio.

Q3) Explain High impedance differential protection scheme.

Q4) Explain Distance relay and state types of Distance realy.

Q5) Explain effect of arc resistance, load encroachment and power swing on distance relays.

Q6) Draw the characteristics of the following distance relays in the R-X diagram and explain

                        i) Mho – relay                   ii) Reactance relay 

Q7) Draw and explain the schematic of an impedance relay and its operating characteristics on R-X diagram.

Q8) Explain the construction, working principle and characteristics or reactance relay type distance relay.

Q9) Derive a generalized mathematical model of distance relays for digital protection.

Q10) Explain the working principle of distance relays.

Q11) Write a short note on WAM.

Q12) Write a short note on setting and co-ordination of distance relay.

Q13) Draw the characteristics of the following distance relays in the R-X diagram and explain

                        i) Quadrilateral – relay                   ii) Impedance-relay 

Q14) Explain realization of distance relays using numerical relaying algorithm.

Q15) What is PLCC? Explain with neat block diagram.

Q16) State advantages and disadvantages of PLCC.

Q17) Explain three stepped distance protection.