Steady-State Solution for Power Networks Modeled at Bus Section Level

This paper extends the conventional power flow formulation in order to enable the solution of networks modeled at the bus section level. The proposed extension is centered on a methodology to represent zero impedance branches successfully employed in state estimation studies. Accordingly, the active and reactive power flows through switches and circuit breakers are treated as new state variables along with the complex voltage at the network nodes. Information regarding device statuses is included into the power flow problem as new (and linear) equations, producing a solvable non-redundant set of algebraic equations. Applications of the proposed modifications in connection with the power flow solution via Newton-Raphson´s method are presented and discussed. The proposed approach provides an efficient tool to directly determine the power flow distribution over selected substations of the network, avoiding unreliable artifices and tedious post-processing procedures required when a conventional power flow formulation is applied. The IEEE 24-bus and IEEE 30-bus test systems are employed to illustrate and evaluate the proposed approach, considering distinct substation layouts.