Maximum Power Flow Analysis of Simultaneous AC-DC Power Transmission System

Abstract

Simultaneous AC-DC system can be used to increase the power flow capacity of existing AC
transmission system. Present analysis shows that simultaneous AC-DC system can be
operated at larger transmission angle compare to pure AC system. In AC system, power flow
increases with the increase of transmission angle. But in simultaneous, AC-DC system power
flow nature with respect to angle is a bit different from pure AC system. That is, initially
power flow increases with the increase of transmission angle and after certain angle the
power flow decreases. It is seen that the maximum power flow occurs at an angle which is
less than 900. This paper presents a detail analysis about the maximum power flow point in
case of simultaneous AC- DC system. The impacts of line voltage, line reactance and thermal
limits of the conductor on the maximum power flow point are also clearly investigated in this
paper. To get the clear view of the occurrence of maximum power flow point a case study is
performed.