Dear Prof. Zimmerman, Thank you very much.
Best Wishes Silvio Miceli On Sat, Mar 24, 2012 at 01:44, Ray Zimmerman <[email protected]> wrote: > As I mentioned before, in MATPOWER's OPF the voltages *are* optimization > variables. In other words, they are *output* values that depend on all of > the input parameters. If you want to treat the voltages at generator buses > as inputs (that you can set randomly according to some distribution), then > you will need to set the VMIN and VMAX values at that corresponding bus to > the desired value before calling the OPF. > > Something like this, where randomvoltage() is a function that returns a > voltage for each generator bus drawn from some specified distribution and > ig is the vector of indexes of generator buses ... > > mpc = loadcase('mybasecase'); > for k = 1:10000 > V = randomvoltage(); % generate a random draw of voltages > mpc.bus(ig, VMIN) = V; > mpc.bus(ig, VMAX) = V; > r = runopf(mpc); > % save whatever outputs you want to collect > end > > -- > Ray Zimmerman > Senior Research Associate > 419A Warren Hall, Cornell University, Ithaca, NY 14853 > phone: (607) 255-9645 > > > > > On Mar 23, 2012, at 7:13 PM, Silvio Miceli wrote: > > Dear Johnny > > I want to do a probabilistic OPF by using Monte Carlo. So, I have to load > a distribution of voltage at the buses. I think MATPOWER is not able to > load variables as optimization variable. If you have an idea please let me > know. > > Best Wishes > > Silvio Miceli > > > On Fri, Mar 23, 2012 at 23:39, Johnny <[email protected]> wrote: > >> Silvio Miceli <[email protected]> writes: >> >> > Dear Shiyang, >> > >> > I also want to do it by Monte Carlo, but not loads. I want to have a >> > distribution of voltage as input. When I load loadcase it gives error. >> My mean >> > is this: >> > I want load variable voltage values in bus matrix. Is it possible? >> > >> >> Silvio, >> >> I believe the best way to achieve this is to generate the normal >> distibution in a script which calls the OPF solver and collect the >> results to display as a distribution. So, in the Monte Carlo, you use >> stochastic input on a Black Box model and collect stochastic >> output. This normally takes some time, but what do you look for really? >> >> >> >> > Best Wishes >> > >> > Silvio Miceli >> > >> > On Fri, Mar 23, 2012 at 23:19, 李诗旸 <[email protected]> wrote: >> > >> > HI Silvio Miceli, >> > >> > I think Mr. Zimmerman’s suggestion is the way like Monte Carlo >> Method. >> > Normally, you may have the distributions of some parameters >> (inputs) such >> > as loads and active generations, then you could use that way to get >> the >> > distributions of the optimized voltages (output) numerically. >> > >> > >> > >> > Sincerely >> > >> > Shiyang Li >> > >> > >> > >> > 发件人: [email protected] [mailto: >> > [email protected]] 代表 Silvio Miceli >> > 发送时间: 2012年3月24日 4:31 >> > 收件人: MATPOWER discussion forum; Ray Zimmerman >> > 主题: Re: probabilistic voltage >> > >> > >> > >> > I want to a have a distribution of voltage at buses that it is an >> > optimization variable in MATPOWER? These distributions are the >> inputs for >> > the OPF. >> > >> > Best Wishes >> > >> > >> > >> > Silvio Miceli >> > >> > On Fri, Mar 23, 2012 at 21:25, Ray Zimmerman <[email protected]> >> wrote: >> > >> > I'm afraid I don't know what *you* mean. The voltages are *outputs* >> of >> > MATPOWER's OPF. So what are the input parameters that you would >> like to be >> > stochastic? Voltage limits? >> > >> > >> > >> > -- >> > >> > Ray Zimmerman >> > >> > Senior Research Associate >> > >> > 419A Warren Hall, Cornell University, Ithaca, NY 14853 >> > >> > phone: (607) 255-9645 >> > >> > >> > >> > >> > >> > >> > >> > On Mar 23, 2012, at 2:40 PM, Silvio Miceli wrote: >> > >> > My problem is this I cannot do loadcase. How can I do many, many >> > deterministic optimization? If I introduce voltage as x and do it >> with a >> > FOR? >> > >> > >> > >> > Could you please explain better? I didn't understand. I am sorry. >> > >> > Best Wishes >> > >> > >> > >> > Silvio Miceli >> > >> > On Fri, Mar 23, 2012 at 19:22, Ray Zimmerman <[email protected]> >> wrote: >> > >> > MATPOWER does not implement any stochastic optimization. All of it's >> > variables and parameters are assumed to be deterministic. However, >> one >> > approach to handling probabilistic parameters is to simply do many, >> many >> > deterministic optimizations, where each one involves, for each >> > probabilistic parameter, drawing a value from the corresponding >> > distribution. Such an approach could use MATPOWER's OPF as a >> subroutine to >> > solve the deterministic sub-problem. >> > >> > >> > >> > -- >> > >> > Ray Zimmerman >> > >> > Senior Research Associate >> > >> > 419A Warren Hall, Cornell University, Ithaca, NY 14853 >> > >> > phone: (607) 255-9645 >> > >> > >> > >> > >> > >> > >> > >> > On Mar 23, 2012, at 12:42 PM, Silvio Miceli wrote: >> > >> > Dear Dr. Zimmerman, >> > >> > >> > >> > I want to have probabilistic voltage or reactive power in an OPF. >> In other >> > words, I want to do OPF with probabilistic variables,e.g. voltage >> should be >> > a normal distribution of voltage. How can insert this kind of >> variables to >> > case file of MATPOWER? Is there this possibility in MATPOWER? >> > >> > >> > >> > Best Wishes >> > >> > >> > >> > Silvio Miceli >> > >> > >> > >> > >> > >> > >> > >> > >> > >> > >> > >> > >> > >> >> -- >> Johnny >> >> >> > >
