Beg your pardon the missing snippet from the previous mail is as follows:
%% initial state %V0 = ones(size(bus, 1), 1); %% flat start V0 = bus(:, VM) .* exp(sqrt(-1) * pi/180 * bus(:, VA)) vcb = ones(size(V0)); %% create mask of voltage-controlled buses vcb(pq) = 0; %% exclude PQ buses k = find(vcb(gbus)); %% in-service gens at v-c buses V0(gbus(k)) = gen(on(k), VG) ./ abs(V0(gbus(k))).* V0(gbus(k)); *SAYANDEV GHOSH* Assistant Professor Electrical Engineering Department Chaibasa Engineering College, Chaibasa, Jharkhand Mob. No. - 7292880077 / 9748509620 On Tue, Aug 8, 2017 at 1:31 PM, Sayandev Ghosh <sayande...@gmail.com> wrote: > 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 >