Many thanks. I will try and if I needed more help, I will ask you On Mon, Feb 11, 2019, 4:19 PM Carlos E Murillo-Sanchez < [email protected] wrote:
> Therein lies the problem. Your optimization procedure, as formulated, has > no say on the resulting voltages. I can think of two suggestions for > dealing with this: > > 1) Instead of a power flow, use an OPF with all non-slack generators' > active power outputs fixed to whatever values were assigned by the > optimization algorithm at the current iteration (set Pmin=Pg=Pmax for those > generators). What this will do is essentially a reactive redispatch which > will try to comply with voltage limits, generation limits and transmission > limits. You can expect the slack generation to vary a little bit to > compensate for the differing amount of losses. > > 2) Include the reactive generation variables in your formulation and > continue using a simple load flow. > > carlos. > > Mohamed Shaheen wrote: > > No, I don't > > On Sun, Feb 10, 2019, 1:24 AM Carlos E Murillo-Sanchez < > [email protected] wrote: > >> Do you include reactive generation in the decision variables of your >> formulation? If you don't, then your optimization algorithm does not >> really have much impact on voltages. >> >> carlos. >> >> Mohamed Shaheen wrote: >> >> I'm currently using penalty functions with GA and Tree-Seed, But after >> running Tree-Seed algorithm including 'runpf' inside, All solutions have >> violations and the algorithm chooses the minimum of these solutions which >> is also a false solution. >> ᐧ >> >> On Sat, 9 Feb 2019 at 15:42, Carlos E Murillo-Sanchez < >> [email protected]> wrote: >> >>> Rather, it seems that your optimization method should take into account >>> any constraint violation and fix the issue by itself. In some methods, >>> such as GA, one way to do this is by using penalty functions on constraint >>> violations. >>> >>> carlos. >>> >>> >>> Mohamed Shaheen wrote: >>> >>> I need to enforce limits, but I aim to get the optimal solution and best >>> parameters using another optimization method called 'Tree Seed' and compare >>> it with 'Genetic Algorithm' after running normal power flow, So I'm not >>> seeking the optimal solution using Matpower itself. >>> Can Matpower help to do this? >>> >>> ᐧ >>> >>> On Fri, 8 Feb 2019 at 23:53, Ray Zimmerman <[email protected]> wrote: >>> >>>> The power flow problem solved by runpf does not take into account >>>> voltage limits. If you need to enforce limits, you can use an appropriately >>>> constrained OPF. >>>> >>>> In this case, it just so happens that the initial voltage specified for >>>> bus 31 in the case57.m file happens to be the voltage at the power flow >>>> solution. >>>> >>>> Ray >>>> >>>> >>>> On Feb 8, 2019, at 2:54 PM, Mohamed Shaheen < >>>> [email protected]> wrote: >>>> >>>> Dear Sir, >>>> >>>> Regarding the case57, the voltage of bus 31 is 0.936 p.u which is less >>>> than the min. limit of bus voltage (0.94). Every time I run 'runpf', the >>>> voltage value is 0.936 and it doesn't change although it is a PQ bus. >>>> I need your help, please. >>>> >>>> Regards, >>>> Mohamed Shaheen. >>>> >>>> Msc. student at Ain Shams University in Egypt >>>> Teaching Assistant in Future University in Egypt >>>> ᐧ >>>> >>>> >>>> >>> >> >
