Dear all, I feel confused about the unit of the shadow price of the line flow constraints in AC based OPF. Since the square of the apparent power is used when building the line flow constraints, the shadow price should be with a unit of $/(MVA*MVA). When it is converted to the shadow price $/MVA, MatPower times the RateA of that line, but for me, it more makes sense if it is multiplied with the apparent power flowing through the line. What is the reason behind multiplying that RateA. Thanks!
Kind regards, Jin
