Thank you so much Dr Ray! I’m so sorry to bother you with careless questions!
Anyway i’ve got the PF running. And the system is very very weak - this is a real case system of a developing country. What i want to do now is to optimise the capacitor bank investment using NSGA-II with 2 objectives - minimizing investment cost and power losses - and voltage deviation from 1 p.u. Obviously OPF itself is an optimisation process and i wish to use this to help my process - my algorithm now is as below. 1) run my candidate solution variables in the OPF 2) get the fitness function (generation cost) 3) use non-domination / diversity comparator and rank solutions 4) GA - select crossover mutate 5) repeat until converge My key question is that - obviously the OPF does not converge now because the system is in need of local VARs! What methods in the OPF object can i use to check if 1) there is convergence so i can add VARs until convergence, 2) or other methods i can use to combine my NSGA algorithm with the OPF Many thanks!!!!! Best Zeya On 12 Jan, 2015, at 11:13 pm, Ray Zimmerman <[email protected]<mailto:[email protected]>> wrote: Let’s start with 3 issues with your input data … 1. gen matrix should have 21 columns, not 10. 2. You have VMIN and VMAX columns in the bus matrix swapped. 3. You have ANGMIN and ANGMAX columns in the branch matrix swapped. Fixing those things won’t make the OPF converge, but the power flow (which converges already) solution should give you some indicators of where to look. Namely, a minimum voltage magnitude of 0.742, to me indicates the need for a lot of additional VArs somewhere. Ray MATPOWER Version 5.0, 17-Dec-2014 -- AC Power Flow (Newton) it max P & Q mismatch (p.u.) ---- --------------------------- 0 2.300e+00 1 3.464e-01 2 9.258e-02 3 1.521e-02 4 5.680e-04 5 7.341e-07 6 1.094e-12 Newton's method power flow converged in 6 iterations. Converged in 0.01 seconds ================================================================================ | System Summary | ================================================================================ How many? How much? P (MW) Q (MVAr) --------------------- ------------------- ------------- ----------------- Buses 84 Total Gen Capacity 2805.0 348.4 to 1742.0 Generators 18 On-line Capacity 2805.0 348.4 to 1742.0 Committed Gens 18 Generation (actual) 1590.6 642.7 Loads 45 Load 1388.6 1041.4 Fixed 45 Fixed 1388.6 1041.4 Dispatchable 0 Dispatchable -0.0 of -0.0 -0.0 Shunts 29 Shunt (inj) -0.0 276.9 Branches 109 Losses (I^2 * Z) 202.04 763.39 Transformers 0 Branch Charging (inj) - 885.2 Inter-ties 0 Total Inter-tie Flow 0.0 0.0 Areas 1 Minimum Maximum ------------------------- -------------------------------- Voltage Magnitude 0.742 p.u. @ bus 58 1.052 p.u. @ bus 13 Voltage Angle -111.02 deg @ bus 43 8.82 deg @ bus 4 P Losses (I^2*R) - 20.92 MW @ line 55-67 Q Losses (I^2*X) - 53.65 MVAr @ line 55-67 On Jan 9, 2015, at 11:41 AM, Zeya Aung [11547809d] <[email protected]<mailto:[email protected]>> wrote: Hi all I’ve tried FAQ #5 - still no convergence. Please help. Attached are the excel file and code to convert into matpower structure. Many thanks. --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Disclaimer: This message (including any attachments) contains confidential information intended for a specific individual and purpose. If you are not the intended recipient, you should delete this message and notify the sender and The Hong Kong Polytechnic University (the University) immediately. Any disclosure, copying, or distribution of this message, or the taking of any action based on it, is strictly prohibited and may be unlawful. The University specifically denies any responsibility for the accuracy or quality of information obtained through University E-mail Facilities. Any views and opinions expressed are only those of the author(s) and do not necessarily represent those of the University and the University accepts no liability whatsoever for any losses or damages incurred or caused to any party as a result of the use of such information. <Myn-Matpower.xlsx><mepe_case.m> Best Zeya --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Disclaimer: This message (including any attachments) contains confidential information intended for a specific individual and purpose. If you are not the intended recipient, you should delete this message and notify the sender and The Hong Kong Polytechnic University (the University) immediately. Any disclosure, copying, or distribution of this message, or the taking of any action based on it, is strictly prohibited and may be unlawful. The University specifically denies any responsibility for the accuracy or quality of information obtained through University E-mail Facilities. Any views and opinions expressed are only those of the author(s) and do not necessarily represent those of the University and the University accepts no liability whatsoever for any losses or damages incurred or caused to any party as a result of the use of such information.
