With any new MATPOWER function, such as scale_load() <http://www.pserc.cornell.edu//matpower/docs/ref/matpower5.1/scale_load.html>, or any Matlab function for that matter, always start by reading the help to understand the input and output arguments and the purpose of the function. For scale_load() <http://www.pserc.cornell.edu//matpower/docs/ref/matpower5.1/scale_load.html> you can’t just pass in case file name and assume it knows what you want it to do.
If you want to double the active and reactive power load (for a fixed, i.e. non-dispatchable, load) at bus k, for example, you can change the values of the PD and QD columns in the bus matrix directly (this is basic Matlab, so go find a good Matlab tutorial if this still looks mysterious) … mpc = loadcase('mycase'); mpc.bus(k, PD) = mpc.bus(k, PD) * 2; mpc.bus(k, QD) = mpc.bus(k, QD) * 2; … or ... nb = size(mpc.bus, 1); load_zone = zeros(nb, 1); load_zone(k) = 1; mpc.bus = loadcase(2, mpc.bus, [], load_zone); Both methods accomplish the same thing, though scale_load() <http://www.pserc.cornell.edu//matpower/docs/ref/matpower5.1/scale_load.html> can also handle dispatchable loads, etc. (see the opt argument). Ray > On Apr 29, 2015, at 12:02 AM, Aruna Dharmala <dharmala.aruna...@gmail.com> > wrote: > > This the error by giving scale_load() > scale_load('case4arunmod.m') > Error using scale_load (line 119) > Not enough input arguments. > > how to fixed the load at given bus and how to change the PD column in the bus > matrix > > On Tue, Apr 28, 2015 at 2:13 PM, Ray Zimmerman <r...@cornell.edu > <mailto:r...@cornell.edu>> wrote: > See scale_load() > <http://www.pserc.cornell.edu//matpower/docs/ref/matpower5.1/scale_load.html>. > Or if it’s a simple fixed load at a given bus, just change the value of the > PD column in the bus matrix. > > Ray > > > >> On Apr 28, 2015, at 4:55 AM, Aruna Dharmala <dharmala.aruna...@gmail.com >> <mailto:dharmala.aruna...@gmail.com>> wrote: >> >> Dear all, >> For available transfer capability calculations i have to >> increase load(sink) at single bus and check the system performance >> by increasing load if their is any voilation in line >> limit that is taken as TTC candidate >> can you please suggest code for increasing load at single >> bus that can implement in matpower >> please help >> >> On Mon, Apr 6, 2015 at 1:07 PM, Ray Zimmerman <r...@cornell.edu >> <mailto:r...@cornell.edu>> wrote: >> I’m not sure I understand what you want to do. You could certainly create a >> new function with the appropriate inputs and outputs, that wraps the code >> below and use it to compute ATC. >> >> Ray >> >> >>> On Apr 6, 2015, at 1:06 AM, Aruna Dharmala <dharmala.aruna...@gmail.com >>> <mailto:dharmala.aruna...@gmail.com>> wrote: >>> >>> Respected sir, >>> how to add the given below program to existing >>> inbuilt opf code in matpower software.....? >>> % get indices of generators >>> ga = find(ismember(mpc.gen(:, GEN_BUS), mpc.bus(a, BUS_I))); % area A gens >>> gb = find(ismember(mpc.gen(:, GEN_BUS), mpc.bus(b, BUS_I))); % area B gens >>> gother = find(~ismember((1:ng)', [ga; gb])); % remaining gens >>> >>> % fix dispatches of all gens outside areas A and B >>> mpc.gen(gother, PMIN) = mpc.gen(gother, PG); >>> mpc.gen(gother, PMAX) = mpc.gen(gother, PG); >>> >>> % scale down prices in area A by factor of 10 >>> % scale up prices in area B by factor of 10 >>> % (important thing is to make everything in A cheaper than >>> % everything in B to maximize transfer from A to B) >>> mpc.gencost(ga, :) = modcost(mpc.gencost(ga, :), 0.1); >>> mpc.gencost(gb, :) = modcost(mpc.gencost(gb, :), 10); >>> >>> % re-run the OPF and compute ATC as total decrease in area B dispatch >>> r = runopf(mpc); >>> ATC = sum(mpc.gen(gb, PG)) - sum(r.gen(gb, PG)); >>> >>> >>> On Thu, Apr 2, 2015 at 1:52 PM, Ray Zimmerman <r...@cornell.edu >>> <mailto:r...@cornell.edu>> wrote: >>> I’ll assume you have a base case power flow (or OPF) solution in a MATPOWER >>> case struct mpc and want to find the maximum additional power that can be >>> transferred from area A to area B without violating constraints, where the >>> areas are defined via two vectors of bus indices (a and b), possibly by >>> using a = find(mpc.bus(:, BUS_AREA) == A), etc. Then you’ll just modify the >>> case, something like this … >>> >>> % get indices of generators >>> ga = find(ismember(mpc.gen(:, GEN_BUS), mpc.bus(a, BUS_I))); % area A gens >>> gb = find(ismember(mpc.gen(:, GEN_BUS), mpc.bus(b, BUS_I))); % area B gens >>> gother = find(~ismember((1:ng)', [ga; gb])); % remaining gens >>> >>> % fix dispatches of all gens outside areas A and B >>> mpc.gen(gother, PMIN) = mpc.gen(gother, PG); >>> mpc.gen(gother, PMAX) = mpc.gen(gother, PG); >>> >>> % scale down prices in area A by factor of 10 >>> % scale up prices in area B by factor of 10 >>> % (important thing is to make everything in A cheaper than >>> % everything in B to maximize transfer from A to B) >>> mpc.gencost(ga, :) = modcost(mpc.gencost(ga, :), 0.1); >>> mpc.gencost(gb, :) = modcost(mpc.gencost(gb, :), 10); >>> >>> % re-run the OPF and compute ATC as total decrease in area B dispatch >>> r = runopf(mpc); >>> ATC = sum(mpc.gen(gb, PG)) - sum(r.gen(gb, PG)); >>> >>> Hope this helps, >>> >>> Ray >>> >>> >>>> On Apr 2, 2015, at 12:10 AM, Aruna Dharmala <dharmala.aruna...@gmail.com >>>> <mailto:dharmala.aruna...@gmail.com>> wrote: >>>> >>>> Respected sir, >>>> I am doing ATC computation by optimal power flow >>>> method.. >>>> By using matpower software i run the load flow >>>> solution by optimal power flow.by <http://flow.by/> doing load flow i am >>>> not geting how to take a group of buses as an area and how to interface >>>> between areas for available transfer capability calculation..? >>>> >>>> On Wed, Apr 1, 2015 at 6:34 PM, Ray Zimmerman <r...@cornell.edu >>>> <mailto:r...@cornell.edu>> wrote: >>>> Another possible approach is to use an OPF and shift the prices down for >>>> the sending group of generators and up for the receiving group. >>>> >>>> Ray >>>> >>>> >>>>> On Apr 1, 2015, at 8:02 AM, Abhyankar, Shrirang G. <abhy...@mcs.anl.gov >>>>> <mailto:abhy...@mcs.anl.gov>> wrote: >>>>> >>>>> Although Matpower does not have a function for ATC, it has all the >>>>> required building blocks for doing the calculations You can take a look >>>>> at the continuation power flow feature in the MatPower manual as a >>>>> starting point. >>>>> >>>>> Shri >>>>> >>>>> On Apr 1, 2015, at 5:07 AM, "Aruna Dharmala" <dharmala.aruna...@gmail.com >>>>> <mailto:dharmala.aruna...@gmail.com>> wrote: >>>>> >>>>>> Respected sir, >>>>>> can we do available transfer capability >>>>>> calculation using matpower it is possible..? >>>>>> if it possible in this software how the >>>>>> interfacing between two areas of available transfer capability takes >>>>>> place for group of buses >>>> >>>> >>> >>> >> >> > >