I would suggest you firstly learn more about the definition of PTDF (power transmission distribution factor). You could also get some hint from its name.. it is a "factor" which basically gives you information as to how power would distribute over the whole network (each line) if you want to transmit some power from one bus to another, of course, linearity is assumed when using PTDF. So, as long as you do not change the topology or parameters of the GRID, the PTDF would keep the same. That is the reason why the results are always the same in your case.
Pls try to cut a line in your network and see. tao From: [email protected] [mailto:[email protected]] On Behalf Of Jaimini Gohel Sent: Wednesday, March 12, 2014 9:49 AM To: MATPOWER discussion forum Subject: Re: regarding makePTDF Sir I tried again to see if am making a mistake in using makePTDF..but its again giving me the same ans and not a single change is there in result. Please if anyone can give me the reason behind it i'l be very thankful. Thank y On Wed, Mar 12, 2014 at 10:22 AM, Jaimini Gohel <[email protected] <mailto:[email protected]> > wrote: Sir there is no specific error that it displays..it just gives me the same ans every time i run it with any loadcase as in changed data. I tried to see again if am doing or entering wrong arguments but I couldn't figure out. What I did was I ran a generator outage case, an increased load case and the normal standard data case (say 6 bus system), and all of them gave me the same result. Why is it not giving any difference between its answers? Will appreciate a quick response. Thank you for your time sir. On Tue, Mar 11, 2014 at 7:25 PM, Ray Zimmerman <[email protected] <mailto:[email protected]> > wrote: There is no way for us to guess without specifics of the error message and the inputs that are producing it. -- Ray Zimmerman Senior Research Associate B30 Warren Hall, Cornell University, Ithaca, NY 14853 phone: (607) 255-9645 On Mar 11, 2014, at 8:20 AM, Jaimini Gohel <[email protected] <mailto:[email protected]> > wrote: Hello, Can someone please tell me why makePTDF is not taking any loadcase data..the one that I want to run and not the standard figures? Whenever I try to it gives me error On Sun, Mar 2, 2014 at 10:53 PM, Jaimini Gohel <[email protected] <mailto:[email protected]> > wrote: thank you so much for your timely help. On Sun, Mar 2, 2014 at 9:06 PM, Jovan Ilic <[email protected] <mailto:[email protected]> > wrote: Jaimini, Reading the help (>> help makePTDF) and an example is probably the best answer here: case4gs = loadcase(case4gs) >> makePTDF(100,case4gs.bus,case4gs.branch,1) ans = 0 -0.7325 -0.1975 -0.5350 0 -0.2675 -0.8025 -0.4650 0 0.2675 -0.1975 -0.5350 0 -0.2675 0.1975 -0.4650 >> makePTDF(100,case4gs.bus,case4gs.branch,2) ans = 0.7325 0 0.5350 0.1975 0.2675 0 -0.5350 -0.1975 -0.2675 0 -0.4650 -0.8025 0.2675 0 0.4650 -0.1975 On Sun, Mar 2, 2014 at 3:33 AM, Jaimini Gohel <[email protected] <mailto:[email protected]> > wrote: I am having a rough time using makePTDF function..every time I try to use that I get the same error saying it has prob in identifying the slack bus and bus type. can anyone please guide me as to how do i use this function? I did read the manual n help instriuctions too and tried to follow them but I guess am not able to interpret those help instructions correctly. Please guide me on this. I'd appreciate a quick response. Thank you -- A pessimist is an optimist with experience.
