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 >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>> >>>>>>> >>>>>> >>> >> >
