Increasing the Effectiveness of Interface MW Limits for Maintaining Voltage Security

Interface MW limits are commonly used as surrogates
for voltage constraints in DC power flow models. This
work proposes a simple improvement to accepted practice so
that the interface MW limits better represent actual voltage
vulnerability. Weights are assigned to the individual lines in the
interface so that the weighted interface MW flows have the same
sensitivity to real power injections as the underlying voltage
constraints. Calculation of the weights requires the solution
of a small dimensional linear regression equation and is of
slight computational burden. The weighted interface MW limit
is demonstrated to be an accurate proxy for low voltage limits
to inter-area transfers using the Nordic test system.