JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD B.Tech IV Year ELECTRICAL DISTRIBUTION SYSTEMS Previous Question Paper (June - 2024 - R16)

Define distribution system.

Obtain the relation between the load factor and loss factor.

State the factors to be considered for location of a substation.

Write about non - three phase primary lines.

List out the main objective of distribution system protection.

What is the importance of coordination of protection devices?

What are the advantages of shunt compensation?

Explain different capacitors.

What are the advantages and disadvantages of automatic voltage booster?

Compare and explain the role of shunt and series capacitor in voltage control.

Draw a block diagram in flow chart form for a typical distribution system planning process and explain the techniques for distribution planning.

Assume that a star connected three phase load is made up of three impedances of 50 angle -25 ohms each and that the load is supplied by a three phase four wire primary express feeder. The balanced line to neutral voltages at the receiving end are Van=7630 angle 0V, Vbn=7630 angle 240V, Vcn=7630 angle 120V. Determine the following, i) The phase currents in each line ii) The line to line phase voltages iii) The total active and reactive power supplied to the load.

Explain briefly the classification of loads and modeling of load in distribution networks?

A 3 phase radial express feeder has a line to line voltage of 22.0 kV at the receiving end, a total impedance of (5.25+J10.95) ohm/phase, and a load of 5MW with a lagging power factor of 0.9. Determine the following: i) Line to neutral and line to line voltage at the sending end ii) Load angle.

How the rating of distribution substation can be calculated. Explain taking a general case with 'n' no. of feeders?

Derive an approximate voltage drop and power loss equation of primary feeder and give the condition for load p.f. at which voltage drop is maximum.

Discuss about the classification of different types of substations. State the advantages and disadvantages of each substation.

Discuss about the different types of manual methods used for the solution of radial networks? Explain them?

Discuss about advantages and disadvantages of fuse to circuit breaker coordination.

The per unit values of positive, negative and zero sequence reactances of a network at fault are 0.08, 0.07 and 0.05 respectively. Determine the fault current if the fault is double line to ground.

Distinguish between the fuse to fuse coordination and fuse to recloser coordination?

The per unit positive, negative and zero sequence impedances of a distributed network are 0.06, 0.06 and 0.04 respectively. Determine the fault current for L-L and L-G faults.

What are the differences between fixed and switched capacitors? What are their effects on distribution systems?

A 3-phase substation transformer has a name plate rating of 7500 kVA and a thermal capability of 125% of the name plate rating. If the connected load is 8816 kVA with a 0.9 power factor (lagging), determine the following: i) the kVAR rating of the shunt capacitor bank required to decrease the kVA load of the transformer to its capability level ii) The power factor of the corrected level.

Why the improvement of power factor is very important for both consumers and generating stations? List the various causes of low power factor and explain.

A single-phase motor takes a current of 10 amps at a p.f. of 0.707 lagging from a 230V, 50 Hz supply. What value must a shunting capacitor have to raise the p.f. to unity.

With the help of a phasor diagram, show how a series capacitor boosts the voltage. What are the drawbacks of this method?

How an AVR can control voltage? With the aid of suitable diagram, explain its function?

Discuss the way to improve the distribution system overall voltage regulation.

How do the shunt capacitors and reactors control the voltage? List the disadvantages of using a shunt capacitor for voltage control?