sir
by calculating like that,i find the elasticity value based on the
prices and demand at one bus and from that elasticity value i calculate
theoritically the load at other buses.and i get the value equal to the load
which i get when i run the power flow.is it absolutely wrong or there may
be chances.please dont feel bad for my doubts
On Tue, Mar 15, 2016 at 10:54 PM, Ray Zimmerman <[email protected]> wrote:
> 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 represent it in positive values i convert like this
>
> On Tue, Mar 15, 2016 at 8:52 PM, Ray Zimmerman <[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 $30 price you are setting.
>>
>> Ray
>>
>>
>>
>> On Mar 14, 2016, at 11:48 AM, Mounika Vanjarapu <
>> [email protected]> wrote:
>>
>> sir
>> thanks for reply.But i think this concept in a different view.
>>
>> i.e i take the marginal benefit cost as the one
>> which we get in the power flow.The price which we set is the high price we
>> are setting. we are representing them as negative costs.so i take it as for
>> example
>> the marginal benefit cost is 40$/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]> 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 $40).
>>>
>>> Ray
>>>
>>>
>>> > On Mar 12, 2016, at 5:08 AM, Mounika Vanjarapu <
>>> [email protected]> wrote:
>>> >
>>> > sir
>>> > i am using price sensitive loads concept.i select the bus 4th as my
>>> dispatchable load.before converting the loads to dispatchable the LMP at
>>> the 4th bus is 40.19$/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.
>>>
>>>
>>>
>>>
>>
>>
>
>
