Mathematical reconsideration of number of variables in power flow computation

Abstract

It has been conventionally believed that there exist 4n variables P, Q, V, for an n-bus system in the power flow computation, while we have 2n power flow equations. In this article, the authors argue that the number of variables in an n-bus system is not 4n but , hence the power flow solution can be obtained without specifying the reference angle of the slack bus. We then deliver a mathematical reasoning why the number of variables in an n-bus system is not 4n but .