Dear All
I am facing convergence problem during the calculation of DCOPF in
IEEE buses. For my work I have fixed the capacity of transmission line 110% of
initial power flow by changing the RATE_A field, then at each time, I increase
the load and generation with a factor (1+alpha). I remove the lines whose power
flow is more than their capacity. After the certain load, the grid divided
into many parts. I tried to solve the island problem but dcopf not converged. I
found on one island the dispatchable load is less than its generation. Should I
take this situation as a blackout??. Please help mePrem Panigrahi Research Scholar India ________________________________ From: prem panigrahi <[email protected]> Sent: Tuesday, June 20, 2017 6:13:37 PM To: [email protected] Subject: DCOPF not converge Hello Sir In IEEE 57 bus, I fixed the capacity of transmission line and then increase the load and generation. I removed those lines whose power flow is more than their capacities. When the grid is divided into 4 parts. I remove the isolated buses. In island 1------- 45 buses are there including 7 generators. Matpower automatically considers the slack bus. But the DCOPF doesn't converge as the generation has a capacity of 1975.9 MW, but it dispatches only 928.9 MW. So there is a mismatch in load and generation. Load requirement is 1321.9 MW. Is there any mistake that I am doing? .
[GROUPS, ISOLATED] = case_info(mpc)
Checking connectivity ... 4 connected groups, 4 isolated buses
Elapsed time is 0.034766 seconds.
================================================================================
Full Island Island Island Island
System 1 2 3 4
Number of: ---------- ---------- ---------- ---------- ----------
buses 57 45 3 3 2
loads 42 35 2 1 2
on 42 35 2 1 2
off - - - - -
fixed 42 35 2 1 2
dispatchable - - - - -
on - - - - -
off - - - - -
generators 7 7 - - -
on 7 7 - - -
off - - - - -
shunt elements 3 2 1 - -
branches 80 59 3 2 1
on 61 55 3 2 1
off 19 4 - - -
ties (off) 14 12 4 3 2
Load
active (MW)
dispatched 1375.9 1321.9 33.6 2.5 5.9
fixed 1375.9 1321.9 33.6 2.5 5.9
dispatchable - - - - -
nominal 1375.9 1321.9 33.6 2.5 5.9
on 1375.9 1321.9 33.6 2.5 5.9
off - - - - -
fixed 1375.9 1321.9 33.6 2.5 5.9
dispatchable - - - - -
on - - - - -
off - - - - -
reactive (MVAr)
dispatched 336.4 317.5 10.4 1.0 2.7
fixed 336.4 317.5 10.4 1.0 2.7
dispatchable - - - - -
nominal 336.4 317.5 10.4 1.0 2.7
on 336.4 317.5 10.4 1.0 2.7
off - - - - -
fixed 336.4 317.5 10.4 1.0 2.7
dispatchable - - - - -
on - - - - -
off - - - - -
Generation
active (MW)
dispatched 928.9 928.9 - - -
max capacity 1975.9 1975.9 - - -
on 1975.9 1975.9 - - -
off - - - - -
min capacity - - - - -
on - - - - -
off - - - - -
reactive (MVAr)
dispatched 193.3 193.3 - - -
max capacity 699.0 699.0 - - -
on 699.0 699.0 - - -
off - - - - -
min capacity -468.0 -468.0 - - -
on -468.0 -468.0 - - -
off - - - - -
Shunt Injections
active (MW) - - - - -
reactive (MVAr) 21.6 11.6 10.0 - -
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 1 0 0 0
ref bus numbers 1 1
--------------------------------------------------------------------------------
Isolated
Buses
Number of: ----------
buses 4
loads 2
on 2
off -
fixed 2
dispatchable -
on -
off -
generators -
on -
off -
shunt elements -
branches -
on -
off -
ties (off) 7
Load
active (MW)
dispatched 12.0
fixed 12.0
dispatchable -
nominal 12.0
on 12.0
off -
fixed 12.0
dispatchable -
on -
off -
reactive (MVAr)
dispatched 4.8
fixed 4.8
dispatchable -
nominal 4.8
on 4.8
off -
fixed 4.8
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
