I am trying to understand the solution provided to a numerical problem based on reactive power compensation. Here's the problem: Two buses A and B are connected by a transmission line of reactance j0.5 pu. Voltages at both the buses are 1 pu. Bus A is connected to a generator. If the complex power demand at bus A and bus B is 1 pu each, what is the rating of the capacitor bank connected at bus B. (There is one capacitor bank at bus 2). Since there is no real power source at bus B, all the real power at bus B must be coming from bus A, through the transmission line. Fine. In the solution provided, they say "since voltages at both the buses are 1 pu, real power at bus B is also 1 pu." I am having trouble understanding this. How can we assume this? The question says "complex" power at bus B is 1 pu. Why is real power at bus B 1 pu? (Final answer given: rating of the capacitor bank= 0.268 MVAR). Are they asking for the "minimum" rating? Thanks a lot in advance!