Benefits of Sparse Tableau over Nodal Admittance Formulation for Power Flow Studies

Assembly of power flow equations has traditionally begun from a nodal analysis formulation of the underlying transmission circuit behavior. Most power flow formulations encapsulate network constraints in the bus admittance matrix, $Y_{bus}$ . From a circuit perspective, this admittance representation restricts network elements to be voltage controlled; resulting drawbacks treating zero impedance branches in such applications as state estimation have long been recognized. This paper explores advantages of alternatives to $Y_{bus}$ -based formulations in power flow. It proposes a Sparse Tableau Formulation (STF), and demonstrates its computational efficiency, robustness and generality in detailed comparison to traditional $Y_{bus}$ -based solution algorithms. In examples of power networks ranging from 1,888 buses to 82,000 buses, computational case studies indicate that STF provides comparable computational speed, while allowing simple treatment of zero impedance branches and more reliably converging to solutions in many cases for which $Y_{bus}$ -based Newton algorithms diverge.