Closed allrashdi10 closed 4 years ago
rdzman
commented
4 years ago It seems likely that there is some problem with the case file, possibly a disconnected network or something. I would start looking at the output of case_info('OETC_PF') to see if it shows anything unexpected.
allrashdi10
commented
4 years ago This is the output I get from case_info
>> Untitled
Checking connectivity ... 4 connected groups, 3 isolated buses
Elapsed time is 0.080425 seconds.
================================================================================
Full Island Island Island Island
System 1 2 3 4
Number of: ---------- ---------- ---------- ---------- ----------
buses 126 84 26 11 2
loads 86 72 8 5 -
on 86 72 8 5 -
off - - - - -
fixed 86 72 8 5 -
dispatchable - - - - -
on - - - - -
off - - - - -
generators 10 1 6 2 1
on 10 1 6 2 1
off - - - - -
shunt elements 74 65 4 5 -
branches 135 96 28 10 1
on 135 96 28 10 1
off - - - - -
ties (off) - - - - -
Load
active (MW)
dispatched 7605.2 6863.6 424.2 223.5 -
fixed 7605.2 6863.6 424.2 223.5 -
dispatchable - - - - -
curtailed - - - - -
nominal 7605.2 6863.6 424.2 223.5 -
on 7605.2 6863.6 424.2 223.5 -
off - - - - -
fixed 7605.2 6863.6 424.2 223.5 -
dispatchable - - - - -
on - - - - -
off - - - - -
reactive (MVAr)
dispatched 2698.6 2455.4 138.9 73.5 -
fixed 2698.6 2455.4 138.9 73.5 -
dispatchable - - - - -
curtailed - - - - -
nominal 2698.6 2455.4 138.9 73.5 -
on 2698.6 2455.4 138.9 73.5 -
off - - - - -
fixed 2698.6 2455.4 138.9 73.5 -
dispatchable - - - - -
on - - - - -
off - - - - -
Generation
active (MW)
dispatched 8230.1 241.9 4425.5 1711.6 1851.1
max capacity 8932.5 263.8 4811.5 1839.0 2018.2
on 8932.5 263.8 4811.5 1839.0 2018.2
off - - - - -
min capacity 2679.8 79.1 1443.5 551.7 605.5
on 2679.8 79.1 1443.5 551.7 605.5
off - - - - -
reactive (MVAr)
dispatched 3396.1 24.7 1700.9 837.8 832.7
max capacity 5359.5 158.3 2886.9 1103.4 1210.9
on 5359.5 158.3 2886.9 1103.4 1210.9
off - - - - -
min capacity -1607.9 -47.5 -866.1 -331.0 -363.3
on -1607.9 -47.5 -866.1 -331.0 -363.3
off - - - - -
Shunt Injections
active (MW) - - - - -
reactive (MVAr) 2795.9 2418.9 174.5 202.4 -
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 0 0 0 1
ref bus numbers 40 40
--------------------------------------------------------------------------------
Isolated
Buses
Number of: ----------
buses 3
loads 1
on 1
off -
fixed 1
dispatchable -
on -
off -
generators -
on -
off -
shunt elements -
branches -
on -
off -
ties (off) -
Load
active (MW)
dispatched 93.9
fixed 93.9
dispatchable -
curtailed -
nominal 93.9
on 93.9
off -
fixed 93.9
dispatchable -
on -
off -
reactive (MVAr)
dispatched 30.8
fixed 30.8
dispatchable -
curtailed -
nominal 30.8
on 30.8
off -
fixed 30.8
dispatchable -
on -
off -
Generation
active (MW)
dispatched -
max capacity -
on -
off -
min capacity -
on -
off -
reactive (MVAr)
dispatched -
max capacity -
on -
off -
min capacity -
on -
off -
Shunt Injections
active (MW) -
reactive (MVAr) -
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 0
ref bus numbers
>>
As I suspected. Your network is not fully connected. You have 4 islands, plus another 3 isolated buses. Make sure that all buses are connected via branches into a single network ... or at least that there are no isolated buses and you have defined a REF bus in each island and each island has adequate generator to supply its own load.
allrashdi10
commented
4 years ago We found the 3 isolated buses and we put ref for them, and the result after that is :
>> Untitled33333
MATPOWER Version 7.0, 20-Jun-2019 -- AC Power Flow (Newton)
Newton's method power flow (power balance, polar) did not converge in 10 iterations.
>>>>> Did Not converge (0.02 seconds) <<<<<
How can we get rid of this?
Also I would like to ask you about the purpose of islands. Because in our project we did not use islands or zones. I mean how can we know the way to separate the islands?
rdzman
commented
4 years ago I think the power flow problem is still caused by a system that is not fully connected. Rather than changing isolated buses to type REF (which will only work if they have a generator that can meet all of their load), you probably want to add the missing branches between them and the rest of the system and between the disconnected islands. Normally you want all buses to be connected into a single network.
allrashdi10
commented
4 years ago After solving the previous problem I proceed to find the OPF of the system but this problem is showing up.
>> dola
MATPOWER Version 7.0, 20-Jun-2019 -- AC Optimal Power Flow
AC OPF formulation: polar voltages, power balance eqns
MATPOWER Interior Point Solver -- MIPS, Version 1.3.1, 20-Jun-2019
(using built-in linear solver)Warning: Matrix is close to singular or badly scaled. Results may be inaccurate. RCOND = 1.714762e-16.
> In mplinsolve (line 70)
In mips (line 467)
In mipsopf_solver (line 129)
In opf_execute (line 86)
In opf (line 232)
In runopf (line 75)
In dola (line 2)
Warning: Matrix is close to singular or badly scaled. Results may be inaccurate. RCOND = 7.953985e-18.
> In mplinsolve (line 70)
In mips (line 467)
In mipsopf_solver (line 129)
In opf_execute (line 86)
In opf (line 232)
In runopf (line 75)
In dola (line 2)
Warning: Matrix is close to singular or badly scaled. Results may be inaccurate. RCOND = 3.907404e-19.
> In mplinsolve (line 70)
In mips (line 467)
In mipsopf_solver (line 129)
In opf_execute (line 86)
In opf (line 232)
In runopf (line 75)
In dola (line 2)
Warning: Matrix is close to singular or badly scaled. Results may be inaccurate. RCOND = 3.104240e-21.
> In mplinsolve (line 70)
In mips (line 467)
In mipsopf_solver (line 129)
In opf_execute (line 86)
In opf (line 232)
In runopf (line 75)
In dola (line 2)
Numerically Failed
Did not converge in 16 iterations.
>>>>> Did NOT converge (1.16 seconds) <<<<<
How to solve it ? :(
rdzman
commented
4 years ago It's hard to say. These sorts of numerical failures can be for a variety of reasons.
The first one to check is for infeasibility of the problem. The easiest way to do that is to try relaxing all branch flow constraints completely by setting the RATE_A column to 0 ...
mpc.branch(:, RATE_A) = 0;... and increasing the generator P and Q ranges sufficient to make sure they are not preventing feasibility. If that works, you can check which of the original limits are violated and begin tightening the constraints again until you identify which one(s) are making the problem infeasible.
If the problem appears to be feasible, you could try turning on the mips.step_control option. If that doesn't help, maybe try a different OPF solver. If you have the Optimization Toolbox, try setting opf.ac.solver to FMINCON. Or try installing IPOPT (e.g. via OPTI Toolbox if you are on MS Windows) and setting opf.ac.solver to IPOPT.
These are just some ideas ...
allrashdi10
commented
4 years ago We try to put all branches equal to zero and then the system code is work! Now we want to know which one is the tightening line because we have 161 line. I mean is there a way to know directly which one is tightening ?
rdzman
commented
4 years ago Try multiplying the RATE_A column by a scale factor instead to relax the limits. Once it is large enough to converge, you should be able to decrease it gradually and observe the shadow prices on the binding constraints MU_SF and MU_ST columns in branch to see which are the flows that bind first and hardest.
Hello, I'm working in my FYP which needs to make a study using the MATPOWER. I was enter all Power Flow data (Generation data, Bus data and Branch data) correctly. when I run this code
where OETC_PF is my Power Flow data. and I get this message :
How can I slove it?