You are making it too complicated (and I confess I still don’t follow what you
are doing).
This line of code …
mpc=load2disp(mpc0,'mo',3,30);
… simply means that you want the load at bus 3 to be curtailed if the nodal
price goes above $30. If the original price (with no curtailment) was $40, you
should expect the load to be curtailed. If you were to use, instead of 30,
something greater than 40, say 45, as the last argument to load2disp(), then
you should see no load curtailment and the solution should be identical to the
original solution.
Ray
> On Mar 15, 2016, at 11:37 AM, Mounika Vanjarapu <[email protected]>
> wrote:
>
> sir
> actually, i run an ieee14 bus system and i get the nodal prices at the
> respective buses.i take the nodal price at 3rd bus as the marginal benefit,to
> reduce the load in that system,i write the code as
> mpc0=loadcase('case14o');
> define_constants;
> >> mpc=load2disp(mpc0,'mo',3,30);
> and i take this 30 as my curtailable price at which the load has to
> curtail.for that i formulate as,
> previously i get the nodal price 40$/MWh.for high price the load
> has to curtail,so since 30 is a negative cost,i take it as 40+(40-30).
> ie.i take them as -40 and -30.so -30 is greater than -40 so load is
> curtailed.to <http://curtailed.to/> represent it in positive values i convert
> like this
>
> On Tue, Mar 15, 2016 at 8:52 PM, Ray Zimmerman <[email protected]
> <mailto:[email protected]>> wrote:
> I’m afraid I don’t understand your description of your view. I am only aware
> of two quantities involved … (1) the marginal benefit or value of the load
> which directly determines the “cost” of the negative generator used to model
> it, and (2) the nodal price computed by the OPF. (1) is an input, (2) is an
> output, and their relative values determine whether or not the load will be
> curtailed.
>
> So, I don’t understand what you mean by the $30 price you are setting.
>
> Ray
>
>
>
>> On Mar 14, 2016, at 11:48 AM, Mounika Vanjarapu <[email protected]
>> <mailto:[email protected]>> wrote:
>>
>> sir
>> thanks for reply.But i think this concept in a different view.
>>
>> i.e i take the marginal benefit cost as the one
>> which we get in the power flow.The price which we set is the high price we
>> are setting. we are representing them as negative costs.so i take it as for
>> example
>> the marginal benefit cost is 40$/MWh,the price we are
>> setting is 30$/MWh.since 30 is a negative cost,the total cost which
>> we we have to impose to the customer is 40+(40-30)=50$/MWh where
>> representing as positive cost.
>> Therefore the high price on the customer is 50$/MWh during
>> peak periods.Is it absolutely wrong view.
>>
>> On Mon, Mar 14, 2016 at 6:50 PM, Ray Zimmerman <[email protected]
>> <mailto:[email protected]>> wrote:
>> It is working as expected. The load will be curtailed when the price is
>> higher than the value you assign to the load. So if you assign a value of
>> $38, and the price is $40, it will be curtailed. If you assign the value to
>> $45, the load will not be curtailed at a price of $40. Essentially, you are
>> saying … this load should only be curtailed if the price goes above $45, so
>> you would not expect any curtailment at lower prices (like $40).
>>
>> Ray
>>
>>
>> > On Mar 12, 2016, at 5:08 AM, Mounika Vanjarapu <[email protected]
>> > <mailto:[email protected]>> wrote:
>> >
>> > sir
>> > i am using price sensitive loads concept.i select the bus 4th as my
>> > dispatchable load.before converting the loads to dispatchable the LMP at
>> > the 4th bus is 40.19$/MWh.now i set the curtailble price at 38 as
>> > mpc=loadcase('case14m');
>> > >> mpc0=load2disp(mpc,'m',4,38);
>> > >> runopf(mpc0)
>> >
>> > MATPOWER Version 5.0b1, 01-Jul-2014 -- AC Optimal Power Flow
>> > MATLAB Interior Point Solver -- MIPS, Version 1.0.2, 01-Jul-2014
>> > Converged!
>> >
>> > Converged in 0.10 seconds
>> > Objective Function Value = 6190.15 $/hr
>> > ================================================================================
>> > | System Summary
>> > |
>> > ================================================================================
>> >
>> > How many? How much? P (MW) Q (MVAr)
>> > --------------------- ------------------- -------------
>> > -----------------
>> > Buses 14 Total Gen Capacity 772.4 -52.0 to
>> > 148.0
>> > Generators 5 On-line Capacity 772.4 -52.0 to
>> > 148.0
>> > Committed Gens 5 Generation (actual) 220.2 71.2
>> > Loads 11 Load 211.2 77.4
>> > Fixed 10 Fixed 211.2 77.4
>> > Dispatchable 1 Dispatchable 0.0 of 47.8 -0.0
>> > Shunts 1 Shunt (inj) -0.0 20.7
>> > Branches 20 Losses (I^2 * Z) 8.97 38.85
>> > Transformers 3 Branch Charging (inj) - 24.3
>> > Inter-ties 0 Total Inter-tie Flow 0.0 0.0
>> > Areas 1
>> >
>> > Minimum Maximum
>> > -------------------------
>> > --------------------------------
>> > Voltage Magnitude 1.011 p.u. @ bus 3 1.060 p.u. @ bus 1
>> > Voltage Angle -13.69 deg @ bus 14 0.00 deg @ bus 1
>> > P Losses (I^2*R) - 2.72 MW @ line 1-2
>> > Q Losses (I^2*X) - 8.30 MVAr @ line 1-2
>> > Lambda P 35.84 $/MWh @ bus 1 40.03 $/MWh @ bus 3
>> > Lambda Q -0.08 $/MWh @ bus 1 0.56 $/MWh @ bus 14
>> >
>> > ================================================================================
>> > | Bus Data
>> > |
>> > ================================================================================
>> > Bus Voltage Generation Load
>> > Lambda($/MVA-hr)
>> > # Mag(pu) Ang(deg) P (MW) Q (MVAr) P (MW) Q (MVAr) P
>> > Q
>> > ----- ------- -------- -------- -------- -------- -------- -------
>> > -------
>> > 1 1.060 0.000* 184.04 0.00 - -
>> > 35.838 -0.084
>> > 2 1.041 -3.889 34.80 25.44 21.70 12.70 37.398
>> > -
>> > 3 1.011 -10.790 1.33 28.24 94.20 19.00 40.026
>> > -
>> > 4 1.018 -7.626 - - 0.00* -0.00*
>> > 38.762 0.161
>> > 5 1.019 -6.692 - - 7.60 1.60
>> > 38.380 0.220
>> > 6 1.060 -12.021 0.00 9.97 11.20 7.50 38.386
>> > -
>> > 7 1.048 -10.804 - - - -
>> > 38.787 0.133
>> > 8 1.060 -10.804 0.00 7.52 - -
>> > 38.787 -
>> > 9 1.045 -12.468 - - 29.50 16.60
>> > 38.802 0.202
>> > 10 1.040 -12.680 - - 9.00 5.80
>> > 38.950 0.308
>> > 11 1.046 -12.482 - - 3.50 1.80
>> > 38.795 0.225
>> > 12 1.045 -12.873 - - 6.10 1.60
>> > 39.007 0.207
>> > 13 1.040 -12.934 - - 13.50 5.80
>> > 39.200 0.343
>> > 14 1.024 -13.692 - - 14.90 5.00
>> > 39.800 0.559
>> > -------- -------- -------- --------
>> > Total: 220.17 71.16 211.20 77.40
>> >
>> > ================================================================================
>> > | Branch Data
>> > |
>> > ================================================================================
>> > Brnch From To From Bus Injection To Bus Injection Loss (I^2 *
>> > Z)
>> > # Bus Bus P (MW) Q (MVAr) P (MW) Q (MVAr) P (MW) Q
>> > (MVAr)
>> > ----- ----- ----- -------- -------- -------- -------- --------
>> > --------
>> > 1 1 2 125.50 -6.03 -122.78 8.50 2.718
>> > 8.30
>> > 2 1 5 58.54 6.03 -56.86 -4.39 1.685
>> > 6.96
>> > 3 2 3 64.90 1.90 -63.07 1.21 1.834
>> > 7.73
>> > 4 2 4 39.83 0.18 -38.98 -1.19 0.853
>> > 2.59
>> > 5 2 5 31.15 2.16 -30.63 -4.25 0.518
>> > 1.58
>> > 6 3 4 -29.80 8.03 30.43 -7.74 0.632
>> > 1.61
>> > 7 4 5 -37.01 9.82 37.19 -9.22 0.189
>> > 0.60
>> > 8 4 7 28.90 -2.65 -28.90 4.28 0.000
>> > 1.63
>> > 9 4 9 16.65 1.76 -16.65 -0.35 0.000
>> > 1.41
>> > 10 5 6 42.69 16.26 -42.69 -11.86 0.000
>> > 4.40
>> > 11 6 11 6.48 4.18 -6.43 -4.08 0.050
>> > 0.11
>> > 12 6 12 7.69 2.60 -7.62 -2.45 0.072
>> > 0.15
>> > 13 6 13 17.31 7.54 -17.10 -7.12 0.210
>> > 0.41
>> > 14 7 8 -0.00 -7.43 0.00 7.52 0.000
>> > 0.09
>> > 15 7 9 28.90 3.15 -28.90 -2.30 0.000
>> > 0.85
>> > 16 9 10 6.09 3.58 -6.08 -3.55 0.015
>> > 0.04
>> > 17 9 14 9.96 3.20 -9.83 -2.93 0.127
>> > 0.27
>> > 18 10 11 -2.92 -2.25 2.93 2.28 0.010
>> > 0.02
>> > 19 12 13 1.52 0.85 -1.51 -0.85 0.006
>> > 0.01
>> > 20 13 14 5.12 2.17 -5.07 -2.07 0.049
>> > 0.10
>> > --------
>> > --------
>> > Total: 8.968
>> > 38.85
>> >
>> > ================================================================================
>> > | Voltage Constraints
>> > |
>> > ================================================================================
>> > Bus # Vmin mu Vmin |V| Vmax Vmax mu
>> > ----- -------- ----- ----- ----- --------
>> > 1 - 0.940 1.060 1.060 518.860
>> > 6 - 0.940 1.060 1.060 72.456
>> > 8 - 0.940 1.060 1.060 79.294
>> >
>> > ================================================================================
>> > | Generation Constraints
>> > |
>> > ================================================================================
>> > Gen Bus Active Power Limits
>> > # # Pmin mu Pmin Pg Pmax Pmax mu
>> > ---- ----- ------- -------- -------- -------- -------
>> > 4 6 1.614 0.00 0.00 100.00 -
>> > 5 8 1.213 0.00 0.00 100.00 -
>> >
>> > Gen Bus Reactive Power Limits
>> > # # Qmin mu Qmin Qg Qmax Qmax mu
>> > --- --- ------- -------- -------- -------- -------
>> > 1 1 0.084 0.00 0.00 10.00 -
>> >
>> > ================================================================================
>> > | Dispatchable Load Constraints
>> > |
>> > ================================================================================
>> > Gen Bus Active Power Limits
>> > # # Pmin mu Pmin Pg Pmax Pmax mu
>> > --- --- ------- -------- -------- -------- -------
>> > 6 4 - -47.80 -0.00 0.00 0.351
>> >
>> > Gen Bus Reactive Power Limits
>> > # # Qmin mu Qmin Qg Qmax Qmax mu
>> > --- --- ------- -------- -------- -------- -------
>> > 6 4 4.868 0.00 0.00 3.90 -
>> >
>> >
>> >
>> >
>> > my doubt is when i set the price at 45 more than the price 40.19 which i
>> > get in normal power flow then the load is not curtailed.
>> > 1.the load should be curtailed for prices more than the marginal cost.but
>> > here the load is curtailed for less prices.why and what is the concept
>> > behind that.
>>
>>
>>
>>
>
>
