Hello, I am Sayandev Ghosh, presently teaching power system in an undergraduate engineering college. I have done my M.Tech on Energy Science from Jadavpur University. I have been using MATPOWER for load flow analysis of till 118 bus by Newton Raphson method. While doing that I am not able to understand the following area:-
In the runpf() function while using Newton Raphson method the initial values of voltage magnitude and voltage angle have been assigned by the following lines (line 177 - 183): [image: Inline image 2] I am having a bit problem in understanding this section. Why are we considering the final values of Voltage magnitude and Voltage angle as the initial guess? In the case files for eg. 'case57' the Vm and Va are probably the final voltage magnitudes and voltage angles. Shouldn't it be like assigning all the voltage magnitudes of PQ bus as 1.0 pu and voltage angles of all PV and PQ bus as 0 degree for a flat start. Depending on the answer of this question I would like to convey my other doubts/questions. Thanks in advance. *SAYANDEV GHOSH* Assistant Professor Electrical Engineering Department Chaibasa Engineering College, Chaibasa, Jharkhand