Yes , the Newton Raphson LF has convergence issues for high R/X ratios. However , does MATPOWER only utilize NR method ? If I could change the method by which is solved the Load Flow, would it be able to still operate for high R/X ratios?
Thank you ________________________________ From: Ray Zimmerman <[email protected]> To: MATPOWER discussion forum <[email protected]> Sent: Friday, April 19, 2013 2:27 PM Subject: Re: Distribution system a) You'll have to try it to see if it works for your system. I just know that Newton method power flow is more likely to have convergence issues as the system moves to higher R/X ratios. b) I simply mean that MATPOWER does not model all 3 phases explicitly; it assumes the 3 phases are balanced and simply uses a single phase to represent the positive sequence components to approximate the 3-phase operation. If you don't know what I'm talking about, check out a good textbook (or on-line tutorial) on symmetrical components for 3-phase networks. -- Ray Zimmerman Senior Research Associate 419A Warren Hall, Cornell University, Ithaca, NY 14853 phone: (607) 255-9645 On Apr 18, 2013, at 8:54 AM, Aftognosia Aftognosia <[email protected]> wrote: Dr Zimmerman >Regarding the modelling of a radial distribution system (eg 11kV system) , you >informed me that MATPOWER should work fine, >except for high R/X ratios. > >a) Could you please specify this numerically? ie R/X > 2 is an example of a >high ratio that could cause problems in MATPOWER ? > >b) Furthermore, when you are referring to a 'balanced system' , what exactly >do you mean? >In distribution systems, 'balanced' system sometimes is the system that has >all its lateral feeders having the same load. >Or do you mean you mean that MATPOWER cannot work with loads such as >inverters, drives , etc which are non-linear? > >Thank you > > > > > > > >________________________________ > From: Ray Zimmerman <[email protected]> >To: MATPOWER discussion forum <[email protected]> >Sent: Tuesday, April 16, 2013 1:20 PM >Subject: Re: MATPOWER > > > >It should work fine depending on the parameters. Very high R/X ratios in the >lines can possibly cause numerical difficulties. And, of course, MATPOWER >would only model a balanced system. It does not model an unbalanced 3-phase >network. > > >-- >Ray Zimmerman >Senior Research Associate >419A Warren Hall, Cornell University, Ithaca, NY 14853 >phone: (607) 255-9645 > > > > >On Apr 15, 2013, at 1:36 PM, Aftognosia Aftognosia <[email protected]> >wrote: > >Hello, >> >> >>Is it possible to use MATPOWER in order to implement ACOPF in a radial >>distribution system ? >> >> >>Are there any limitations for distribution system? >> >> >> > > >
