Here's IMHO the simplest explanation of the equations I'm trying to solve: http://home.eng.iastate.edu/~jdm/ee458_2011/PowerFlowEquations.pdf
Right now we're just trying to solve eq(5) (in section 1), inverting the linear Y-bus matrix. Eventually we have to be able to solve equations like those in the next section. On Thu, Jan 31, 2019 at 1:47 PM Matthew Knepley <knep...@gmail.com> wrote: > On Thu, Jan 31, 2019 at 3:20 PM Justin Chang via petsc-users < > petsc-users@mcs.anl.gov> wrote: > >> Hi all, >> >> I'm working with some folks to extract a linear system of equations from >> an external software package that solves power flow equations in complex >> form. Since that external package uses serial direct solvers like KLU from >> suitesparse, I want a proof-of-concept where the same matrix can be solved >> in PETSc using its parallel solvers. >> >> I got mumps to achieve a very minor speedup across two MPI processes on a >> single node (went from solving a 300k dog system in 1.8 seconds to 1.5 >> seconds). However I want to use iterative solvers and preconditioners but I >> have never worked with complex numbers so I am not sure what the "best" >> options are given PETSc's capabilities. >> >> So far I tried GMRES/BJACOBI and it craps out (unsurprisingly). I believe >> I also tried BICG with BJACOBI and while it did converge it converged >> slowly. Does anyone have recommendations on how one would go about >> preconditioning PETSc matrices with complex numbers? I was originally >> thinking about converting it to cartesian form: Declaring all voltages = >> sqrt(real^2+imaginary^2) and all angles to be something like a conditional >> arctan(imaginary/real) because all the papers I've seen in literature that >> claim to successfully precondition power flow equations operate in this >> form. >> > > 1) We really need to see the (simplified) equations > > 2) All complex equations can be converted to a system of real equations > twice as large, but this is not necessarily the best way to go > > Thanks, > > Matt > > >> Justin >> > > > -- > What most experimenters take for granted before they begin their > experiments is infinitely more interesting than any results to which their > experiments lead. > -- Norbert Wiener > > https://www.cse.buffalo.edu/~knepley/ > <http://www.cse.buffalo.edu/~knepley/> >