Shruti is right, the value you obtain for lambda is valid for all the network, since voltage collapse is a global phenomenon (in other words, you'll see a nose point at the same value of lambda regardless of which bus you choose to plot). Remember that lambda represents a fraction along the vector of injections linearly iterpolating [P_base, Q_base] to [P_target, Q_target]. The value of Lambda at the nose point is NOT the maximum loading point for that bus; rather, it is the maximum loading value along the path to the particular load/gen profile chosen as a target.
Of course, one may wonder about this other problem: for a given profile [P_base, Q_base], what is the target direction [P_target, Q_target] for which one would obtain the shortest value of critical lambda? If this is what you're thinking about, then it is in general a hard problem. I suggest these references by Ian Dobson, on the concept of "shortest distance" to voltage collapse: - http://www.ece.wisc.edu/~dobson/PAPERS/publications.html#loading -- Jose L. Marin Gridquant España SL Grupo AIA On Mon, Aug 10, 2015 at 6:23 AM, nilesh patel <[email protected]> wrote: > > Sir, > When we run continuation power flow for particular system, we get p-v > curve for selected bus. using this p-v curve, we can find Voltage stability > Margin (in MW) on that bus by difference of operating point to nose point > lamda. > I agree lambda at nose point provides maximum loading value but > that is for that bus only for which p-v curve is plotted. > > My question is How to find Voltage Stability Margin for whole Network > using P-V curve ? I mean how to find maximum lamda for whole network using > p-v curve? > > Thanks. > > From: "Abhyankar, Shrirang G." <[email protected]> > Sent: Fri, 07 Aug 2015 22:31:31 > To: MATPOWER discussion forum <[email protected]> > Subject: Re: PV curve using CPF > I donⴠquite understand your question, can you please elaborate. > > The maximum value of loading scaling parameter ᬡmbda⠧ives a measure of how > much power can be transferred for a given transfer direction. So, lambda is > also a measure of the nose point for the whole network. > > Shri > > From: nilesh patel <[email protected]> > Reply-To: MATPOWER discussion forum <[email protected]> > Date: Friday, August 7, 2015 at 8:46 AM > To: matpower-l <[email protected]>, MATPOWER-L < > [email protected]> > Subject: PV curve using CPF > > Dear Sir, > P-V curve solution using continuation power flow gives nose point (maximum > loading point) for individual bus. > > My question is - How to get nose point for whole network (all buses) using > PV curve ? I want to find network voltage stability margin rather than > individual bus margin using CPF. > > Thanks. > > > Nilesh Patel > > Get your own *FREE* website, *FREE* domain & *FREE* mobile app with > Company email. > *Know More >* > <//www.rediffmail.com/cgi-bin/red.cgi?red=http%3A%2F%2Ftrack%2Erediff%2Ecom%2Fclick%3Furl%3D%5F%5F%5Fhttp%3A%2F%2Fbusinessemail%2Erediff%2Ecom%3Fsc%5Fcid%3Dsign%2D1%2D10%2D13%5F%5F%5F%26amp%3Bcmp%3Dhost%26amp%3Blnk%3Dsign%2D1%2D10%2D13%26amp%3Bnsrv1%3Dhost&isImage=0&BlockImage=0&rediffng=0&rogue=387537254f7eee557c3b17544bd037e8098bd82e> > <https://sigads.rediff.com/RealMedia/ads/click_nx.ads/www.rediffmail.com/signatureline.htm@Middle?> > > > > <https://sigads.rediff.com/RealMedia/ads/click_nx.ads/www.rediffmail.com/signatureline.htm@Middle?> > Get your own *FREE* website, *FREE* domain & *FREE* mobile app with > Company email. > *Know More >* > <http://track.rediff.com/click?url=___http://businessemail.rediff.com?sc_cid=sign-1-10-13___&cmp=host&lnk=sign-1-10-13&nsrv1=host> >
