And for redispatch case as you have mentioned , if I want the generators redispatch in a certain way (make them produce power like Pg+some factor*some variable), how should I do that?
On Tue, Apr 9, 2019 at 4:56 PM Jubeyer Rahman <[email protected]> wrote: > 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 >>>>>>>>>>>> >>>>>>>>>>>> >>>>>>>>>>>> >>>>>>>>>> >>>>>>>>> >>>>>>>> >>>>> >>>> >>> >>
