thank you Yi
On Tue, Jun 4, 2013 at 2:30 AM, <[email protected]> wrote: > Hi Yi Liang, > I think most of your questions are beyond the scope of this forum and are > not with simple answers. So maybe it's more proper to discuss on other > professional forums. > 1. I never use Matpower for the system as large as 30k bus, but I could > predict with high confidence that it cannot be done within one second. I > suggest you ask this kind of questions only after you run several given > test systems in Matpower. Actually, if you have tried the 2~3k bus systems, > the answer is obvious. I ever solved power flow for eastern interconnection > by PSS/E. It takes tens of seconds. But the system contains models much > more complicated than those in Matpower. > > 2. No one can give you a simple answer for this question I guess. Because > computing time is determined by many factors, including your model in > details, algorithm, codes and your computer capability. Several minutes are > possible. > > 3. Again, I suggest you try the given test systems first. > > 4. It's really a big question. I just want to say Matpower is not for > industrial application, especially on real-time platform. I guess you may > need even more than one year of study to get the full answer for relevant > questions. > > 5. Again, read the manual first. > > 6. Did you loss a "price" ? > > Shiyang Li > > ----- 原始邮件 ----- > 发件人：Yi Liang <[email protected]> > 收件人：MATPOWER discussion forum <[email protected]> > 主题：Re: A general question about large scale power system > 日期：2013年06月04日 13点27分 > > Dear Dr. Zimmerman, > > Thanks very much for your reply. I have some more questions. > 1, Can I know for 30,000 bus system, how long will it take to run a AC > power flow in MATPOWER? Can it be done in less than one second? or in > seconds, or in tens of seconds, or in mins? > Still for 30,000 bus system, can you also let me know how long will it > take by using the fastest power flow solution method, if you know anything > about it? > > 2, As far as I know, OPF is usually slower than PF. If the objective > function is the loss of the power at lines, which is a quadratic function, > then how long will it take to run an AC OPF on a 30,000 bus system? > > 3, Compare to using AC model, how long does it take for DC PF and DC OPF > in MATPOWER for 30,000 bus system? > > 4, As far as I know, from the data in PNNL (Pacific North National Lab), > the SCADA data is feed into the control center every 4 seconds. If I want > to predict normal current flows (consider AC model) and voltages and > determine the voltage levels to avoid under or over voltage problems, how > fast should it be ? Since the power system can be unstable in seconds, is > it correct that we need to finish that in less than 10 seconds? Can > MATPOWER be that fast? > > 5, For the price, do we need to update the electricity price hourly or > even every minute? Is it possible for matpower to solve a certain kind of > OPF to achieve that goal? > 6, And does the industry want to update the electricity as frequently as > possible? > > > I really appreciate you reading this email. Thank you for your kindly > help. > > Best Regards, > Yi Liang > > > > > > > > > On Mon, Jun 3, 2013 at 2:10 PM, Ray Zimmerman <[email protected]> wrote: > > 1. Some might consider 30,000 buses to be large. Certainly systems of this > size are solved in industry. It depends on the level of the modeling, but > I've seen models of the U.S. Eastern Interconnect that are on the order of > 60,000 buses. > > 2. Of course, and the requirement depends on the application. > > 3. It depends on the system, PF vs. OPF, AC vs DC model, the solver, etc., > etc. The range of run-times can vary over several orders of magnitude. > > -- > Ray Zimmerman > Senior Research Associate > B30 Warren Hall, Cornell University, Ithaca, NY 14853 > phone: (607) 255-9645 > > > > > > On Jun 2, 2013, at 7:34 PM, Yi Liang <[email protected]> wrote: > > > Dear all, > > > > I am wondering if the performance of current power flow analysis tool is > good enough in terms of speed. > > 1, What is the size of a power system that is large in reality? 30,000 > bus -system? > > What is the size of the United States power system? > > > > 2, In the real industrial world, is there any requirements for the > speed? what is it? > > > > 3, If we use MATPOWER to solve the power flow analysis problems and the > OPF problems, how long will it take? I don't have that kind of test cases > in hand, so I cannot test them. Can anyone theoretically estimate the time > complexity? As far as I know, it depends on the iterations it takes for > newton's method( for example, if we use newton's method) > > > > > > > Thank you! > > > > Best Regards, > > Yi > > > > > > -- Yi Liang, Master Candidate Room 403, Coordinated Science Laboratory Department of Electrical and Computer Engineering University of Illinois at Urbana Champaign 1308 W Main Street, Urbana, IL, 61801-2307
