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 $30 price you are setting.
Ray
> On Mar 14, 2016, at 11:48 AM, Mounika Vanjarapu <[email protected]>
> wrote:
>
> sir
> thanks for reply.But i think this concept in a different view.
>
> i.e i take the marginal benefit cost as the one which
> we get in the power flow.The price which we set is the high price we are
> setting. we are representing them as negative costs.so i take it as for
> example
> the marginal benefit cost is 40$/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.
>
>
>
>
