Formulation and Convexity of an Approximate Energy Function for Power System Operation

It is suggested in the literature that the stationary point of the energy function is exactly equivalent to the power flow solution. However, a general form of exact energy function has been proven to be nonexistent. This letter derives an approximate energy function by intentionally approximating the network transfer conductance and theoretically characterizes its convex domain. Further, an energy function-based convex optimization is established for power flow calculations. Case studies on multiple test systems validate the effectiveness of the proposed method.