This model demonstrates the transmission of active power through a purely inductive transmission line, connected to two infinite buses with a phase-to-phase voltage of 10 kV. The generator at portA of the line has 30 deg phase, the other one has 0 deg phase. The reactance of each conductor is 1 Ohm.
The active power flow from portA to portB is
P = 3(VA*VB)/X*sin(delta)= UA*UB/X*sin(delta) = 50 MW.
By choosing a base power of 100 MW and a base voltage of 10 kV, the active power flow from portA to portB is 0.5 p.u.