Hi, Thanks a lot for your reply.
Are you referring to Ar matrix ( The A matrix multiplied with Pg here) from the reserve formulation (since this is a subtraction with the variable z)? So, If I want to implement anything like, Pg-z*factor= Po; where Po is the dispatch in pre-contingency case how should I do it? The way I am thinking to do is, I will run the pre-contingency case, preserve the 'Pg' data, and pass it as the 'Pmin' for the redistpatch period. Then I will add the z variable with the OPF structure. I apologize I could not come up with a proper formulation as I am not quite sure what I am thinking is correct or not. Regards, Jubeyer On Tue, Apr 16, 2019 at 9:01 AM Ray Zimmerman <[email protected]> wrote: > Add a single constraint of the form … > > A * Pg - z = 0 > > … where A is a row vector, Pg is the vector of generation and z is a new > scalar variable representing the total amount of the resdispatch. > > Ray > > > On Apr 9, 2019, at 5:56 PM, Jubeyer Rahman <[email protected]> wrote: > > 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 >>>>>>>>>>>>> >>>>>>>>>>>>> >>>>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>> >>>>>>>>> >>>>>> >>>>> >>>> >>> >
