I am really sorry that I haven't been able to make it more clear. However, I will come up with a clear formulation later on.
Actually, I have already formualted that and am getting some value for R. But I am not quite sure whether I have been able to get the cost formulation correct. So, for now , can you only tell me, that if I do get some value for R, which is supposed to come from some certain generator's, how can I make that calculated as a total power generation Pg+R from the gencost information and not from the reserve cost. On Tue, Apr 9, 2019 at 4:50 PM Ray Zimmerman <[email protected]> wrote: > I’m afraid I still don’t understand the problem you intend to solve. The > formulation you provided is completely equivalent to the standard OPF with > some additional variables and constraints that have no effect ultimately > (since r_i = 0 is feasible). > > It sounds like you want to apply some kind of constraint to Pg to restrict > redispatches from some initial dispatch or something, but the formulation > you provided does not accomplish that. > > So, it seems like the first step would be to get the problem formulation > clear and correct, then we can help if you have questions about the > implementation. > > Ray > > > On Apr 9, 2019, at 4:33 PM, Jubeyer Rahman <[email protected]> wrote: > > Yes, I don't want the objective function to be affected in that way. The > reason of formulating that way is if I don't have all the generators active > in my system (in case I loose one generator for example, I want the rest > of the generator's to respond in a certain way). > > On Tue, Apr 9, 2019 at 4:30 PM Ray Zimmerman <[email protected]> wrote: > >> I think there must be something missing. Because the addition of these >> variables and constraints will not affect the OPF solution at all. It will >> be the same as the standard OPF formulation with no reserves. That is, the >> original solution will still be both optimal (since there is no change to >> the objective function in (6.34)) and feasible (since r_i = 0 is feasible >> and imposes no additional restrictions on the problem). >> >> Your formulation as stated includes no reason for r_i to be non-zero. >> >> Ray >> >> >> >> On Apr 9, 2019, at 3:33 PM, Jubeyer Rahman <[email protected]> wrote: >> >> Ok. Here they go: >> >> similar to 7.2 >> >> 0<=r_i<=Pmax >> >> for 7.3: Since I don't want the cost to be calculated separately, I don't >> need anything here (reserves from generators should be calculated as the >> total power generation cost, no separate cost for generator) >> >> for 7.4 >> pg^i+x*r_i<=pg^i,max >> >> x is given as parameters here. >> >> for 7.5; since I don't have zonal requirement I don't have anything for >> that. >> >> Let me know if you need anything for more clarification. >> >> >> >> On Tue, Apr 9, 2019 at 3:13 PM Ray Zimmerman <[email protected]> wrote: >> >>> Ok, so you are attempting to modify the existing fixed reserves >>> implementation to something with a similar, but not identical structure. I >>> think I need to fully understand the formulation. Can you provide the >>> equivalent of equations (7.2)–(7.5) for your problem so I can see exactly >>> where the differences are? >>> >>> Ray >>> >>> >>> On Apr 9, 2019, at 11:43 AM, Jubeyer Rahman <[email protected]> wrote: >>> >>> Ok. Thanks a lot for your reply. >>> >>> What I am trying to implement is something like this 'Pg+x*R', where >>> 'Pg' is real power generation, x is a collection of factors (parameters) >>> usually fraction number ranging between 0 and 1, and R will be a variable >>> for reserves. Usually the minimum value for R is 0 and maximum value is >>> equal to the 'Pmax' for each generator asked to provide reserves. What I >>> also want is that the reserve cost to be ignored ,rather the cost of total >>> power generation 'Pg+x*R' should be calculated from the generator cost >>> information and not from the reserve costs ( I have tried that by making >>> all the reserve costs zero). In addition to these I have no zonal reserve >>> requirement ( I have made the constraint deactivated and deleted the second >>> row of the mpc.reserves.zones, deactivated mpc.reserves.req and also >>> deactivated where 'req' has been implemented). >>> >>> >>> Can you suggest how can how I do it? or do you have any comments on the >>> process I am already following? >>> >>> Just to illustrate more on the reserve cost modification: >>> >>> For example, I have 'Pg' from a particular generator (generator 1) 5 >>> MW, now after implementing the reserve , it is supplying another 1 MW from >>> its capacity (it's Pmax is 10 MW). Now what I want is that this (5+1)=6 MW >>> generation cost to be calculated by using the polynomial cost information >>> from the mpc.gencost section. >>> >>> >>> >>> On Tue, Apr 9, 2019 at 10:38 AM Ray Zimmerman <[email protected]> wrote: >>> >>>> I think it might help me to have a high-level view of what you are >>>> trying to accomplish. If you are simply trying to *use* the already >>>> implemented fixed reserve capability, you shouldn’t need to even concern >>>> yourself at all with the implementation (i.e. the Ar matrix and the various >>>> callback functions, etc.). In that case, all you need is to understand the >>>> inputs in Table 7-5. If, on the other hand, you are modifying the >>>> implementation to do something other than what is currently implemented, >>>> then I need to understand what that is. >>>> >>>> In what is already implemented, the generation cost is simply the cost >>>> of Pg. There is a separate cost of R that is added as a user cost. See >>>> (7.3). So the cost coefficients of R are provided in mpc.reserves.cost >>>> (see Table 7-5). >>>> >>>> Ray >>>> >>>> >>>> >>>> On Apr 8, 2019, at 2:39 PM, Jubeyer Rahman <[email protected]> wrote: >>>> >>>> Hi, >>>> >>>> I have another few questions regarding the addition of the fixed zonal >>>> reserves. So, far I understand, after adding the reserves, the real power >>>> output of the generator will be added with reserve amount, so in the part >>>> of the objective function where real power cost is being calculated, which >>>> power is fed into as for calculation is it the 'Pg' part of 'Pg+R' or is it >>>> the total 'Pg'? >>>> >>>> If I want to implement a reation like 'Pg+x*R' , where x is a >>>> collection of parameters (n-by-1) , which place can I feed into these >>>> parameters? I am assuming, this should be the second column of the Ar >>>> matrix. Is that correct? >>>> >>>> Regards >>>> >>>> >>>> >>>> On Fri, Apr 5, 2019 at 10:53 AM Jubeyer Rahman <[email protected]> >>>> wrote: >>>> >>>>> Please ignore the last email, I have figured this out. Every column in >>>>> the first row corresponds the generators supposed to participate in the >>>>> reserve provision , that's why they are made one. >>>>> >>>>> On Wed, Apr 3, 2019 at 5:27 PM Jubeyer Rahman <[email protected]> >>>>> wrote: >>>>> >>>>>> Are you talking about the columns in the second row? >>>>>> >>>>>> On Mon, Apr 1, 2019 at 5:21 PM Ray Zimmerman <[email protected]> >>>>>> wrote: >>>>>> >>>>>>> The only thing you need to do is make sure the corresponding column >>>>>>> in mpc.reserves.zones is all zeros. >>>>>>> >>>>>>> Ray >>>>>>> >>>>>>> On Apr 1, 2019, at 10:31 AM, Jubeyer Rahman <[email protected]> >>>>>>> wrote: >>>>>>> >>>>>>> Ok, I got your point and realized my mistake in understanding the >>>>>>> zone handling section. So, if I want some of the generator's choosing >>>>>>> not >>>>>>> to provide ramp, should just setting the element of Identity matrix's >>>>>>> corresponding rows of first column of Ar be Ok? or I may need to change >>>>>>> something else as well? >>>>>>> >>>>>>> On Mon, Apr 1, 2019 at 9:45 AM Ray Zimmerman <[email protected]> >>>>>>> wrote: >>>>>>> >>>>>>>> Regarding your first question, as described by (7.2) in the User’s >>>>>>>> Manual, the reserve for a given generator is bounded above by both any >>>>>>>> limit provided in mpc.reserves.qty (r_i^{max}) and by any physical >>>>>>>> ramp rate (∆_i) given in mpc.gen(:, RAMP_10). It just so happens >>>>>>>> that the example in t_case30_userfcn does not specify any physical >>>>>>>> ramp rates, but the code still needs to handle cases which *do* provide >>>>>>>> physical ramp limits. >>>>>>>> >>>>>>>> I’m not sure why you say only two generators are supposed to take >>>>>>>> part in the reserve provision. In t_case30_userfcn there are two >>>>>>>> reserve zones defined, but all 6 generators are able to participate in >>>>>>>> providing the required reserves. >>>>>>>> >>>>>>>> You may want to review carefully the formulation in (7.2)–(7.5) and >>>>>>>> Table 7-2. >>>>>>>> >>>>>>>> Ray >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> On Mar 29, 2019, at 4:06 PM, Jubeyer Rahman <[email protected]> >>>>>>>> wrote: >>>>>>>> >>>>>>>> Referring to the 'userfcn_reserves_formulation', there is a line >>>>>>>> which is finding the value of k, which seems to be zero since none of >>>>>>>> the >>>>>>>> data in 'Ramp_10' column in t_case_30_userfcn is all zeros. so I >>>>>>>> don't >>>>>>>> see any point of using the line >>>>>>>> >>>>>>>> Rmax(k)=mpc.gen(k,Ramp_10), can you explain why the code is written >>>>>>>> that way. >>>>>>>> >>>>>>>> From my understanding only two generators are supposed to take part >>>>>>>> in the reserve provision, but the while putting the value for Rmax and >>>>>>>> Rmin, the code is considering all of them, which looks kind of >>>>>>>> unreasonable >>>>>>>> to me. Can you please explain this section as well? >>>>>>>> >>>>>>>> Regards, >>>>>>>> Jubeyer >>>>>>>> >>>>>>>> On Fri, Mar 29, 2019 at 12:43 PM Ray Zimmerman <[email protected]> >>>>>>>> wrote: >>>>>>>> >>>>>>>>> That is correct. All of the callbacks are technically optional. >>>>>>>>> Typically you need the formulation callback to implement the >>>>>>>>> actual problem modifications, and possibly ext2int and int2ext if >>>>>>>>> you need to do some handling of input and output data, respectively. >>>>>>>>> The >>>>>>>>> printpf and savecase callbacks are only needed if you want to add >>>>>>>>> things to the standard pretty-printed output or saved case data. >>>>>>>>> >>>>>>>>> Ray >>>>>>>>> >>>>>>>>> >>>>>>>>> On Mar 29, 2019, at 12:15 PM, Jubeyer Rahman <[email protected]> >>>>>>>>> wrote: >>>>>>>>> >>>>>>>>> Just how important it is to include printpf and savecase callback >>>>>>>>> during the extension of OPF, if I don't really need anything printed >>>>>>>>> out >>>>>>>>> right after I call the power flow? Will it be still possible to >>>>>>>>> extract >>>>>>>>> information from the 'results' when I say results=runopf(mycase)? >>>>>>>>> >>>>>>>>> To my understanding, after runopf being called, 'results' struct >>>>>>>>> will be returned and can be accessed by writing some command like >>>>>>>>> results.gen(:,2), etc. Let me know if I am thinking correctly or not? >>>>>>>>> >>>>>>>>> On Fri, Mar 29, 2019 at 9:53 AM Jubeyer Rahman <[email protected]> >>>>>>>>> wrote: >>>>>>>>> >>>>>>>>>> Thank you very much. >>>>>>>>>> >>>>>>>>>> On Fri, Mar 29, 2019 at 8:43 AM Ray Zimmerman <[email protected]> >>>>>>>>>> wrote: >>>>>>>>>> >>>>>>>>>>> Are you attempting to use the provided extension for fixed >>>>>>>>>>> reserves, or are you attempting to write your own extension? >>>>>>>>>>> >>>>>>>>>>> If it’s the former, the full implementation is included in >>>>>>>>>>> toggle_reserves() >>>>>>>>>>> <http://www.pserc.cornell.edu/matpower/docs/ref/matpower6.0/toggle_reserves.html>. >>>>>>>>>>> Simply load your case file, use toggle_reserves() to enable the >>>>>>>>>>> callbacks, then run the OPF (or just call runopf_w_res() >>>>>>>>>>> <http://www.pserc.cornell.edu/matpower/docs/ref/matpower6.0/runopf_w_res.html>, >>>>>>>>>>> which does these 3 steps automatically for you). >>>>>>>>>>> >>>>>>>>>>> If you are attempting to write your own extension, I suggest >>>>>>>>>>> making a copy of toggle_reserves.m and rename it and all of the >>>>>>>>>>> functions in it and use it as a template for your own extension. >>>>>>>>>>> >>>>>>>>>>> Ray >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> On Mar 28, 2019, at 12:40 PM, Jubeyer Rahman <[email protected]> >>>>>>>>>>> wrote: >>>>>>>>>>> >>>>>>>>>>> Hi, >>>>>>>>>>> >>>>>>>>>>> Recently I was digging through the extending OPF chapter of >>>>>>>>>>> Matpower manual, but I don't quite catch the process. Regarding the >>>>>>>>>>> example >>>>>>>>>>> given there on 'Fixed zonal reserves' what I understand from my >>>>>>>>>>> reading is, >>>>>>>>>>> it is required to write down a call back function for formulation >>>>>>>>>>> along >>>>>>>>>>> with some call of callback functions. I have followed every steps >>>>>>>>>>> mentioned >>>>>>>>>>> there but could not make the code run (I am using version 6.0). I >>>>>>>>>>> am adding >>>>>>>>>>> my code snippet here for better conveying. >>>>>>>>>>> >>>>>>>>>>> %%% >>>>>>>>>>> mpc=loadcase('case30.m'); >>>>>>>>>>> mpopt = mpoption('out.all', 0, 'verbose', 0); >>>>>>>>>>> mpc=add_usefcn(mpc,'formulation',@userfcn_reserves_formulation); >>>>>>>>>>> mpc=ext2int(mpc,mpopt); >>>>>>>>>>> results=runopf(mpc); >>>>>>>>>>> results=int2ext; >>>>>>>>>>> >>>>>>>>>>> %%%% >>>>>>>>>>> *Error message:* >>>>>>>>>>> *Access to an object's fields is only permitted within its >>>>>>>>>>> methods.* >>>>>>>>>>> >>>>>>>>>>> I have added the mpc.reserve data(cost, req, zones) posted in >>>>>>>>>>> 't_case30_userfcns.m' file. >>>>>>>>>>> I have written the userfcn_reserves_formulation in a different >>>>>>>>>>> script , but it is not working. >>>>>>>>>>> I didn't write the add_var and add_constraint explicitly since >>>>>>>>>>> the add_userfcn callback function already contains those. >>>>>>>>>>> >>>>>>>>>>> Can you tell me what I am missing? >>>>>>>>>>> >>>>>>>>>>> Regards, >>>>>>>>>>> Jubeyer >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>> >>>>>>>> >>>>>>> >>>> >>> >> >
