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Concept of the Day GATE 2015 Preparation

Advantages of DC electric power transmission:
1. It requires only two conductors.

2. There is no problem of inductance, capacitance and phase displacement which is common in ac transmission.

3. For the same load and sending end voltage, the voltage drop in dc transmission lines is less than that in ac transmission.

4. As there is no skin effect on conductors, therefore entire cross-section of conductor is usefully utilized thereby affecting saving in material.

5. For the same value of voltage insulating materials on dc lines experience less stress as compared to those on ac transmission lines.

6. A dc line has less corona loss and reduced interference with communication circuits.

7. There is no problem of system instability so common in ac transmission.

Advantages of AC electric power Transmission:
1. Power can be generated at high voltages as there is no commutation problem.

2. Ac voltages can be conveniently stepped up or stepped down.

3. High voltage transmission of ac power reduces losses.

Trigonometric identities and formulae