Dear Ray Sir
In my case i have 4 Island and remove the buses of 3 Island
having no generation and the Island 1 have a reference bus. In generation side
dispatched load is less than the capacity due to which there is a mismatch in
load and generation. Is it a natural case or I can manually increase the
dispatch load from generation unit.
[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
________________________________
From: [email protected]
<[email protected]> on behalf of Ray Zimmerman
<[email protected]>
Sent: Monday, July 3, 2017 9:15:52 PM
To: MATPOWER discussion forum
Subject: Re: DCOPF not converge
Hi Prem,
If you are solving each island individually, the DC OPF should converge as long
as (1) you have a reference bus in the island, (2) there is adequate generation
to cover the load in the island, and (3) the line constraints do not prevent
the generated power from reaching the loads.
Ray
On Jun 23, 2017, at 9:18 AM, prem panigrahi
<[email protected]<mailto:[email protected]>> wrote:
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 me
Prem Panigrahi
Research Scholar
India
________________________________
From: prem panigrahi
<[email protected]<mailto:[email protected]>>
Sent: Tuesday, June 20, 2017 6:13:37 PM
To: [email protected]<mailto:[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? .
<result.txt>
