Dear all I am facing problem in DCOPF. I need help. In my power grid model i have fixed the capacity of transmission line in RATE A column by 110% of initial power flow. Then increase the load by a factor (1.01) and run the dcopf. But matpower showing infeasible model due to which it is not converging. I am not able to understand the problem. Here load and generation is also well balanced. Now which parameter constraint to converging of my test case. I stuck here for a long time, so please help me
The result shown below is after increasing the load by 1.01. MATPOWER Version 6.0, 16-Dec-2016 -- DC Optimal Power Flow Gurobi Version 7.0.2 -- automatic LP solver Optimize a model with 19515 rows, 4968 columns and 47500 nonzeros Coefficient statistics: Matrix range [2e-03, 9e+05] Objective range [1e+02, 2e+02] Bounds range [5e-03, 1e+02] RHS range [3e-17, 4e+02] Concurrent LP optimizer: dual simplex and barrier Showing barrier log only... Presolve removed 2 rows and 17 columns Presolve time: 0.06s Solved with dual simplex Solved in 0 iterations and 0.07 seconds Infeasible model >>>>> Did NOT converge (0.17 seconds) <<<<< Checking connectivity ... single fully connected network Elapsed time is 0.051284 seconds. ================================================================================ Full System Number of: ---------- buses 3989 loads 2227 on 2227 off - fixed 2227 dispatchable - on - off - generators 979 on 979 off - shunt elements 247 branches 8096 on 8096 off - ties (off) - Load active (MW) dispatched 85879.4 fixed 85879.4 dispatchable - nominal 85879.4 on 85879.4 off - fixed 85879.4 dispatchable - on - off - reactive (MVAr) dispatched 23668.6 fixed 23668.6 dispatchable - nominal 23668.6 on 23668.6 off - fixed 23668.6 dispatchable - on - off - Generation active (MW) dispatched 86451.8 max capacity 213706.7 on 213706.7 off - min capacity -72665.3 on -72665.3 off - reactive (MVAr) dispatched 24069.5 max capacity 69809.7 on 69809.7 off - min capacity -50352.2 on -50352.2 off - Shunt Injections active (MW) - reactive (MVAr) 10848.8 Branch Losses active (MW) - reactive (MVAr) - DC line export (MW) dispatch - max capacity - on - off - min capacity - on - off - Reference Buses num of ref buses 1 ref bus numbers 3292 ________________________________ From: bounce-121637002-78651...@list.cornell.edu <bounce-121637002-78651...@list.cornell.edu> on behalf of Ray Zimmerman <r...@cornell.edu> Sent: Monday, July 3, 2017 9:33:26 PM To: MATPOWER discussion forum Subject: Re: DCOPF not converging for large system If you have a solved AC power flow, that’s a good start. Normally, the first step I try when faced with an OPF that won’t converge is to eliminate the branch flow limits by setting the RATE_A column of the branch matrix to zero (or by increasing the values by some factor). In your case, you can check which flows in the power flow solution exceed their limits and only relax those to begin with. If I were you, I would relax any branch, voltage and generator limits as required to make the power flow solution you have feasible for the AC OPF problem. It should solve. If it does, then you can begin to eliminate those relaxations to find the source of the infeasibility. Ray On Jun 23, 2017, at 10:55 AM, Mort D. Webster <md...@psu.edu<mailto:md...@psu.edu>> wrote: Dear Matpower Folks: I have larger network that is a solved load flow case from an ISO. The AC power flow converges fine, but neither AC nor DC OPF solve. I supplied my own estimated generator costs, and perturbed them so that none are identical. I get the following error: >> mpc = iso2015sum mpc = version: '2' baseMVA: 100 bus: [7108x13 double] gen: [720x25 double] branch: [8930x13 double] bus_name: {7108x1 cell} dcline: [4x17 double] gencost: [720x6 double] >> results = rundcopf(mpc) opf_setup: Warning: Multiple reference buses. For a system with islands, a reference bus in each island may help convergence, but in a fully connected system such a situation is probably not reasonable. MATPOWER Version 6.0b2, 01-Nov-2016 -- DC Optimal Power Flow The interior-point-legacy algorithm uses a built-in starting point; ignoring supplied X0. Exiting: One or more of the residuals, duality gap, or total relative error has stalled: the primal appears to be infeasible and the dual unbounded since the dual objective > 1e+10 and the primal objective > -1e+6. >>>>> Did NOT converge (7.52 seconds) <<<<< results = version: '2' baseMVA: 100 bus: [7108x17 double] gen: [720x25 double] branch: [8930x21 double] bus_name: {7108x1 cell} dcline: [4x17 double] gencost: [720x6 double] order: [1x1 struct] om: [1x1 opf_model] x: [7700x1 double] mu: [1x1 struct] f: 2.1192e+06 var: [1x1 struct] lin: [1x1 struct] et: 7.5220 success: 0 raw: [1x1 struct] The system has several complex features: 4 HVDC lines several storage resources as generators 4 buses as reference/slack bus type many "isolated" bus types ("4"). Can you suggest where in the results I can look to diagnose the problem? Thanks so much! Mort Webster -- Mort Webster Associate Professor of Energy Engineering Dept of Energy and Mineral Engineering Pennsylvania State University University Park, PA 16802 (814) 863-1640 m...@psu.edu<mailto:m...@psu.edu>