Application of three-phase load flow to power system distribution automation

The authors introduce three-phase distribution power flow in a rigid approach for large-scale distribution systems. The solution method is the optimally ordered triangular factorization Y_Bus, Method (implicit Z_Bus Gauss Method). This method not only takes advantage of the sparsity of system equations but also has very good convergence characteristics from a distribution systems point of view. The detailed component models along with suitable solution techniques are the essence of more accurate simulation results of a system. Detailed component models, therefore, are needed for all system components in the simulation. Utilizing the phase frame representation for all network elements, a program, entitled `Generalized Distribution Analysis Systems-GDAS´, with a number of features and capabilities not found in existing packages has been developed for large-scale distribution system simulations. The system being analyzed can be unbalanced. It can be a radial, network (loop), or mixed type distribution system. Furthermore, because the individual phase representation is employed for both system and component models, the system can comprise single, double, and three-phase systems simultaneously. Additionally, with detailed component models, the program can also perform system loss and contingency analyses