Advantages of DC over AC

However there are some advantages for DC over AC


DC power maintains a constant direction of current. One advantage of DC power is there is no reactance in the line. 


This allows higher power transfer capability, higher capacity utilization of generators, and less of a voltage drop along the line. 

DC also has a lower line resistance than AC because of the “skin effect” in AC. This is when charge is carried mostly near the outside of the wire.

In the DC system, power is just the real component. This means that the transmission system operator need not worry about the sufficiency of reactive power to maintain the security and stability of the system.

In DC, there is no frequency, so generators connected to the transmission grid do not need to be synchronized.

The DC system does not introduce susceptance along the line thus removing the effect of changing current and over voltages in the system.

Analysis of DC systems only involves real numbers, while AC systems involve complex numbers. (Think about a world without AC; How easy will be the calculations in Electrical Engineering :-) )