2. I’m not sure where you are referring to, but numerical sensitivity calculations can be performed with any small perturbation (either direction). 3. It looks like you probably have an old get_losses() function in your Matlab path that is overriding the one provided by MATPOWER 5.
Ray > On Jan 29, 2015, at 11:06 PM, nivedita arunachalam > <[email protected]> wrote: > > 1. k. Then I get higher values after optimization while using LSF to place my > DG than I get from weak bus placement. > 2. And another question is for voltage sensitivities why do you add epsilon > to voltage why not to subtract. > 3. I get an error > > >> t_get_losses > Error using get_losses > Too many output arguments. > > Error in t_get_losses (line 99) > [loss, fchg, tchg, dloss_dV, dchg_dVm] = get_losses(r); > > why does this occur. > > Nivedita..... > > On Thu, Jan 29, 2015 at 9:37 PM, Ray Zimmerman <[email protected] > <mailto:[email protected]>> wrote: > In the t/t_get_losses.m file, the loss sensitivities are computed > analytically and numerically (just to check the correctness of the > analytically computed ones). The analytical computation of the sensitivities > is certainly much more computationally efficient. Adding them across all > lines does give you sensitivities of total losses, which I believe is what > you want. The only part I’m not convinced about is subtracting epsilon from > both PD and QD at the same time. This sensitivity of losses to simultaneous > and equal changes PD and QD seems an odd sort of sensitivity to me. > > Ray > > >> On Jan 29, 2015, at 9:40 AM, nivedita arunachalam >> <[email protected] <mailto:[email protected]>> wrote: >> >> Dear Ray, >> I am working on optimal placement and optimal sizing of solar >> generators on standard ieee 30 bus system. I determine the size of >> generators using different algorithms and for optimal placement I use two >> methods weak bus placement and loss sensitivity factor method. I calculate >> the Loss sensitivity factor numerically alone as on the file you sent me. >> But I subtract the epsilon values to both PD and QD at the same time. And >> calculated the LSF. To order the sensitivity I added all the line losses >> togather and ordered them. I got to know from the codings that the matrix I >> got as numLSF is from making changes to each bus and gives line losses. This >> is want I understood and process. Am I right or not. Please suggest me. >> > >
