Mathematical reconsideration of number of variables in power flow computation

Abstract It has been conventionally believed that there exist 4n variables P, Q, V, θ 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 nbus system is not 4n but 4n−1, hence the power flowsolution can be obtained without specifying the reference angle of the slack bus.We then deliv…