Ok, using the example from Section 5.5 in the manual, after running the code in
the example on p. 38 to solve the case …
>> base_load = total_load(mpcb.bus)
base_load =
315
>> target_load = total_load(mpct.bus)
target_load =
787.5000
>> results.cpf.max_lam
ans =
0.9876
>> critical_load = base_load + results.cpf.max_lam * (target_load - base_load)
critical_load =
781.6386
--
Ray Zimmerman
Senior Research Associate
B30 Warren Hall, Cornell University, Ithaca, NY 14853 USA
phone: (607) 255-9645
> On Feb 9, 2015, at 3:55 AM, Natakorn Thasnas <[email protected]> wrote:
>
> Dear Ray,
>
> Regarding your previous email. Could you please explain more detail with
> example calculation how to get the values of critical power? Because I am
> new for continuation power flow.
>
> Best Regards,
>
> Natakorn Thasnas
>
> 2015-02-04 4:33 GMT+07:00 Ray Zimmerman <[email protected]
> <mailto:[email protected]>>:
> Hi Arun,
>
> Since MATPOWER’s continuation power flow transfer is set up in a very general
> fashion as the difference between a base and target case, which may involve
> changes at multiple buses, there isn’t a single “power” number associated
> with each step. However, you can recover any power of interest from the
> results.cpf.lam_p and/or results.cpf.lam_c values and transfer (target -
> base) vector from equation (5.3) in the manual. The lambda values are used to
> interpolate between the base injections (lambda = 0) and the target
> injections (lambda = 1).
>
> --
> Ray Zimmerman
> Senior Research Associate
> B30 Warren Hall, Cornell University, Ithaca, NY 14853 USA
> phone: (607) 255-9645
>
>> On Feb 3, 2015, at 12:47 PM, arun s nair <[email protected]
>> <mailto:[email protected]>> wrote:
>>
>> Hi All
>>
>> I am trying to use matpower to evaluate IEEE 39 bus system. I am able to
>> plot the PV curve of load buses and was also able to get the critical power
>> and voltage values.
>>
>> I would like to know if its possible to get the power values at each
>> iterations along with the voltage values ?
>>
>>
>> I am using runcpf, and used the below code.
>>
>> mpopt = mpoption('out.all',0,'verbose',2,'out.bus',1);
>> mpopt = mpoption(mpopt,'cpf.stop_at','nose','cpf.step',0.2);
>> mpopt = mpoption(mpopt,'cpf.plot.bus',3,'cpf.plot.level',2);
>>
>> mpcb = loadcase('case39'); % load base case
>> mpct = mpcb; % set up target case with
>> %mpct.gen(:,[PG QG]) = mpcb.gen(:,[PG QG])*2.5;
>> mpct.bus(3,PD) = mpcb.bus(3,PD)*2.5;
>> results = runcpf(mpcb, mpct, mpopt);
>>
>> CriticalPower = results.bus(3,3)
>> CriticalVoltage = results.bus(3,8)
>>
>>
>> Thanking in advance
>>
>> With Regards.
>>
>> Arun Nair
>
>
