Step-by-Step Formation of Bus Admittance Matrix

An algorithm has been developed to form the bus admittance matrix Ybu,, by forming the network through a step-by- step addition of a line or a passive element to the system, taking into account the mutual coupling between the elements. Two sets of formulas have been derived for the addition of a tree branch and for the addition of a link. This method eliminates the formation of incidence matrices and does not require singular or nonsingular transformations. This algorithm is very convenient for calculation in digital computers.