I agree with Uriel that many of these parameters cannot simply be assumed without more information about the system. You can make up numbers, but the OPF results will be garbage. I think you need more information.
Ray > On Nov 3, 2014, at 8:55 AM, Zeya Aung [11547809d] <zya....@connect.polyu.hk> > wrote: > > Thanks Ureil! > > Do you have some reference to support the Qmin= -1/3 Qmax assumption? If it > is a good approximation used in the industry, i think it’s justified to make > this assumption in my project. > > What do you think should i assume the values of RateA B C for the Matpower > case format branch data? > > Many thanks. > Will appreciate if anyone else has some comments on my 4 problems. > > Best > Zeya > > On 3 Nov, 2014, at 9:22 pm, Uriel Fernando Sandoval <uriel_sando...@ieee.org> > wrote: > >> Hi Zeya, >> >> >> I’ll try to answer some of your questions: >> >> 1) Reactive power consumption (Qmin) is typically smaller than Qmax. >> Sometimes a good approximation is to take Qmin= -1/3 Qmax, but to a better >> assumptions you have to look at the generator’s capability curve. >> >> 2) If you are doing PF analysis you don’t need these parameters. But in my >> opinion the line’s capacity typically are between 25-1000 MW. This parameter >> depends on the physical construction of the line and i think you can’t >> assume it. >> >> 3) The best way is to use either pice-wise or quadratical convex functions. >> If you have a set of points that represent the generator cost under >> different powers, you can approximate this set to a quadratical function >> using least squares regression. >> >> 4) This data is very important and you should not assume it. if you can >> obtain the cost functions you should run an OPF to dispatch active power >> generation and then you will have a base case to perform all your steady >> state analysis. >> >> >> Best regards, >> >> Uriel >> >> >> >> >> >> >>> El 02/11/2014, a las 14:09, Zeya Aung [11547809d] >>> <zya....@connect.polyu.hk> escribió: >>> >>> Anyone help with this question please….? Really need some feedback to >>> continue my work. >>> >>> Many thanks guys!!! >>> >>> Best >>> Zeya >>> >>> On 24 Oct, 2014, at 12:22 am, Zeya Aung <115478...@connect.polyu.hk> wrote: >>> >>>> Hey guys >>>> >>>> I’m missing some data in my real case analysis. Please advise on the best >>>> approximation methods and assumptions. >>>> >>>> 1) Generator (min and max Q limit) - I’ve the power factor and capacity, >>>> and i suppose the max Q generation can be assumed using the p.f, but how >>>> about min Q? >>>> 2) Line transfer capacity - I’ve all the impedance, susceptance, and >>>> length, should i set 9900 in rateA of manpower format? Is this realistic? >>>> 3) Generator cost functions - for hydropower, coal power and natural gas >>>> turbines, how can i best approximate the cost functions? >>>> 4) I’ve the load profile (i.e. max load per month at transformers) but i >>>> do not have the generator data supplying this load. What can i do about >>>> this considering there are no accurate generation cost functions to run a >>>> optimal power flow and get a steady state solution? >>>> >>>> Many thanks. >>>> >>>> >>>> >>>> Best >>>> Zeya >>>> >>> >>> >>> --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- >>> Disclaimer: >>> >>> This message (including any attachments) contains confidential information >>> intended for a specific individual and purpose. If you are not the intended >>> recipient, you should delete this message and notify the sender and The >>> Hong Kong Polytechnic University (the University) immediately. Any >>> disclosure, copying, or distribution of this message, or the taking of any >>> action based on it, is strictly prohibited and may be unlawful. >>> >>> The University specifically denies any responsibility for the accuracy or >>> quality of information obtained through University E-mail Facilities. Any >>> views and opinions expressed are only those of the author(s) and do not >>> necessarily represent those of the University and the University accepts no >>> liability whatsoever for any losses or damages incurred or caused to any >>> party as a result of the use of such information. >>> >>> >> >> >> > > > --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- > Disclaimer: > > This message (including any attachments) contains confidential information > intended for a specific individual and purpose. If you are not the intended > recipient, you should delete this message and notify the sender and The Hong > Kong Polytechnic University (the University) immediately. Any disclosure, > copying, or distribution of this message, or the taking of any action based > on it, is strictly prohibited and may be unlawful. > > The University specifically denies any responsibility for the accuracy or > quality of information obtained through University E-mail Facilities. Any > views and opinions expressed are only those of the author(s) and do not > necessarily represent those of the University and the University accepts no > liability whatsoever for any losses or damages incurred or caused to any > party as a result of the use of such information. > >
