RE: Removing a bus with its branch

[prem panigrahi]

Hi Sir,
No  its not working.

Please correct me if I am wrong.
I believe that Matpower is mapping the array index number with bus number.
this is because, whenever I remove  a bus, perhaps the application is deleting 
the bus along with the index (may be matpower reducing array size after the 
removal of each bus), due to this when ever I remove a bus the index also 
changes. to explain this I am giving an example along with my artifacts.

I am taking approx. 4k bus for the network where the largest number of bus is 
3995.
After removing 220 bus i see the index has been rearranged and when application 
is trying to remove a bus number 3967 bus it throws array out of bound. Matlab 
command window showing following error

val =
3967
Index in position 1 exceeds array bounds. Index must not exceed 3771.
Error in testing_indian (line 24)
bn = mpc.bus(val, BUS_I);


I am, attaching the excel data sheet showing bus number with index before error 
and after error for a better clarification.

Please do let me know if I could clearly put my error statement.

Sent from Mail<https://go.microsoft.com/fwlink/?LinkId=550986> for Windows

From: Ray Daniel Zimmerman<mailto:r...@cornell.edu>
Sent: Thursday, January 13, 2022 10:36 PM
To: MATPOWER-L<mailto:matpowe...@list.cornell.edu>
Subject: Re: Removing a bus with its branch

Oops, looks like there was a typo in my example code for you. Sorry about that.

The line …

mpc.branch(k, BUS_TYPE) = NONE;

… should be …

mpc.bus(k, BUS_TYPE) = NONE;

Hopefully, that’ll fix it.

   Ray




On Jan 12, 2022, at 5:08 AM, prem panigrahi 
mailto:prempanigr...@outlook.com>> wrote:

Dear Ray Sir,  wish you are fine and healthy
 with your suggestion I am able to automate the bus and branch removal process 
with some assumption. But now I am facing another problem for which My program 
get halted. Error code showing

val =

3967

Index in position 1 exceeds array bounds. Index must not exceed 3771.

Error in testing_indian (line 24)
bn = mpc.bus(val, BUS_I);

When buses are removed there is a mismatch in array size and bus number. I have 
total 3995 number of buses, after the removal of 224 bus its coming to 3771 
bus. When I am trying to remove the bus number 3967 the above error is coming. 
How to handle this problem.

k=[1204 1051 296 300 3296 1011 3309 35 2300 872 3254 1067 39 1202 1506 1875 291 
1064 173 1496 1894 137 41 1682 983 196 3235 1882 239 1230 6 176 3311 1220 2310 
932 1504 2783 1079 232 890 564 1665 3236 104 2322 3347 130 215 2297 240 1285 
2050 114 1907 1060 1692 136 157 955 1087 753 107 144 50 2878 1439 97 2061 3304 
951 147 2076 1881 342 1198 2081 28 967 200 376 3316 1394 1256 33 329 1688 2850 
1214 3579 1494 1866 289 674 2841 47 1460 875 169 3410 1705 3010 63 1926 873 
2844 295 1048 3387 751 2053 111 400 199 1492 1097 3279 161 70 195 224 2869 1870 
132 1096 3 2306 3337 474 836 427 1558 3319 146 1670 2835 19 3348 1886 1168 3275 
124 1701 307 32 2859 2056 1427 2388 168 16 1092 1686 3967 1012 3298 459 3629 
2795 2298 25 1072 1712 1799 2810 1891 3308 191 221 293 84 944 129 2302 769 1666 
1212 1449 662 282 170 869 3416 2866 1065 3282 1869 1892 2849 250 115 3418 1247 
829 2317 1865 1897 1206 1699 134 2736 518 1344 9 2814 2345 1777 493 158 2214 
3240 1678 2525 61 203 262 155 2431 3305 126 320 92 1053 1104 2787 2831 1906 
2344 1301 1585 3280 2883 476 2052 2382 3633 1755 929 900 759 80 48 1013 1091 
469 1441 566 776 1046 2065 3255 2772 265 100 2296 2305 2 225 1797 1184 1419 344 
1901 3370 121 3657 2295 946 2798 1119 1237 2871 46 3292 887 430 1239 3335 2099 
1094 1880 3276 2888 356 1219 2863 34 407 285 3293 878 138 73 2799 382 2223 761 
1142 3343 699 1108 1917 868  233 256 3653 898 2325 3239 1730 3949 2741 3646 
2346 1590 316 856 1798 457 216 3422 349 1922 2441 290 437 2738 1395 874 2721 
480 2243 1223 2308 632 694 3355 2837 4 1107 1657 2054 1790 120 2808 677 1147 
3947 2881 167 2862 1128 758 440 1226 1280 2211 2229 3386 283 2193 141 1438 1878 
2855 2414 2993 1787 148 1397 483 1598 2728 3658 22 1411 2762 3955 2875 3662 
1257 2734 2340 2237 3301 1904 241 3329 456 1735 2378 3268 1898 881 2062 1695 
486 1689 2740 2197 1899];
z = [];
len = length(k)
for x=1:len
val = k(x)
bn = mpc.bus(val, BUS_I);
i = find(mpc.branch(:, F_BUS) == bn);
j = find(mpc.branch(:, T_BUS) == bn);
mpc.branch(val, BUS_TYPE) = NONE;
mpc.branch([i; j], BR_STATUS) = 0;
g = find(mpc.gen(:, GEN_BUS) == bn);
mpc.gen(g, GEN_STATUS) = 0;
[groups, isolated] = find_islands(mpc)
mpc_list = extract_islands(mpc)
[GROUPS, ISOLATED] = case_info(mpc)
mpc.bus([ISOLATED],BUS_TYPE)=4
results=rundcpf(mpc,opt);
if (results.success == 0)
[groups, isolated] = find_islands(mpc)
mpc_list = extract_islands(mpc)
[GROUPS, ISOLATED] = case_info(mpc)
mpc.bus([ISOLATED],BUS_TYPE)=4
mpc = extract_islands(mpc, GROUPS, 1)
   results=rundcpf(mpc,opt);
end
F1=results.bra

RE: Removing a bus with its branch

[prem panigrahi]

Dear Ray Sir,  wish you are fine and healthy
 with your suggestion I am able to automate the bus and branch removal process 
with some assumption. But now I am facing another problem for which My program 
get halted. Error code showing

val =

3967

Index in position 1 exceeds array bounds. Index must not exceed 3771.

Error in testing_indian (line 24)
bn = mpc.bus(val, BUS_I);

When buses are removed there is a mismatch in array size and bus number. I have 
total 3995 number of buses, after the removal of 224 bus its coming to 3771 
bus. When I am trying to remove the bus number 3967 the above error is coming. 
How to handle this problem.

k=[1204 1051 296 300 3296 1011 3309 35 2300 872 3254 1067 39 1202 1506 1875 291 
1064 173 1496 1894 137 41 1682 983 196 3235 1882 239 1230 6 176 3311 1220 2310 
932 1504 2783 1079 232 890 564 1665 3236 104 2322 3347 130 215 2297 240 1285 
2050 114 1907 1060 1692 136 157 955 1087 753 107 144 50 2878 1439 97 2061 3304 
951 147 2076 1881 342 1198 2081 28 967 200 376 3316 1394 1256 33 329 1688 2850 
1214 3579 1494 1866 289 674 2841 47 1460 875 169 3410 1705 3010 63 1926 873 
2844 295 1048 3387 751 2053 111 400 199 1492 1097 3279 161 70 195 224 2869 1870 
132 1096 3 2306 3337 474 836 427 1558 3319 146 1670 2835 19 3348 1886 1168 3275 
124 1701 307 32 2859 2056 1427 2388 168 16 1092 1686 3967 1012 3298 459 3629 
2795 2298 25 1072 1712 1799 2810 1891 3308 191 221 293 84 944 129 2302 769 1666 
1212 1449 662 282 170 869 3416 2866 1065 3282 1869 1892 2849 250 115 3418 1247 
829 2317 1865 1897 1206 1699 134 2736 518 1344 9 2814 2345 1777 493 158 2214 
3240 1678 2525 61 203 262 155 2431 3305 126 320 92 1053 1104 2787 2831 1906 
2344 1301 1585 3280 2883 476 2052 2382 3633 1755 929 900 759 80 48 1013 1091 
469 1441 566 776 1046 2065 3255 2772 265 100 2296 2305 2 225 1797 1184 1419 344 
1901 3370 121 3657 2295 946 2798 1119 1237 2871 46 3292 887 430 1239 3335 2099 
1094 1880 3276 2888 356 1219 2863 34 407 285 3293 878 138 73 2799 382 2223 761 
1142 3343 699 1108 1917 868  233 256 3653 898 2325 3239 1730 3949 2741 3646 
2346 1590 316 856 1798 457 216 3422 349 1922 2441 290 437 2738 1395 874 2721 
480 2243 1223 2308 632 694 3355 2837 4 1107 1657 2054 1790 120 2808 677 1147 
3947 2881 167 2862 1128 758 440 1226 1280 2211 2229 3386 283 2193 141 1438 1878 
2855 2414 2993 1787 148 1397 483 1598 2728 3658 22 1411 2762 3955 2875 3662 
1257 2734 2340 2237 3301 1904 241 3329 456 1735 2378 3268 1898 881 2062 1695 
486 1689 2740 2197 1899];
z = [];
len = length(k)
for x=1:len
val = k(x)
bn = mpc.bus(val, BUS_I);
i = find(mpc.branch(:, F_BUS) == bn);
j = find(mpc.branch(:, T_BUS) == bn);
mpc.branch(val, BUS_TYPE) = NONE;
mpc.branch([i; j], BR_STATUS) = 0;
g = find(mpc.gen(:, GEN_BUS) == bn);
mpc.gen(g, GEN_STATUS) = 0;
[groups, isolated] = find_islands(mpc)
mpc_list = extract_islands(mpc)
[GROUPS, ISOLATED] = case_info(mpc)
mpc.bus([ISOLATED],BUS_TYPE)=4
results=rundcpf(mpc,opt);
if (results.success == 0)
[groups, isolated] = find_islands(mpc)
mpc_list = extract_islands(mpc)
[GROUPS, ISOLATED] = case_info(mpc)
mpc.bus([ISOLATED],BUS_TYPE)=4
mpc = extract_islands(mpc, GROUPS, 1)
   results=rundcpf(mpc,opt);
end
F1=results.branch(:,PF);
F1=abs(F1);
ss=sum(F1);
fprintf('%d \n',ss)

   z(x) = double(ss)

end
display(z)


Sent from Mail<https://go.microsoft.com/fwlink/?LinkId=550986> for Windows

From: Ray Daniel Zimmerman<mailto:r...@cornell.edu>
Sent: Tuesday, December 7, 2021 1:56 AM
To: MATPOWER-L<mailto:matpowe...@list.cornell.edu>
Subject: Re: Removing a bus with its branch

MATPOWER does not include any code to do that automatically, but it’s trivial 
to write. Suppose k is the vector of indices of buses to eliminate. The 
following code should eliminate the buses and the branches.

bn = mpc.bus(k, BUS_I);
i = find(mpc.branch(:, F_BUS) == bn);
j = find(mpc.branch(:, T_BUS) == bn);
mpc.branch(k, BUS_TYPE) = NONE;
mpc.branch([i; j], BR_STATUS) = 0;

Btw, you may need to eliminate generators too.

g = find(mpc.gen(:, GEN_BUS) == bn);
mpc.gen(g, GEN_STATUS) = 0;

Best regards,

Ray




On Dec 6, 2021, at 11:56 AM, prem panigrahi 
mailto:prempanigr...@outlook.com>> wrote:

Dear Ray sir
Yes you are right. I am facing problem during automate the process. 
Actually I need to remove approx.. 400 buses, and each time after removal I 
need to calculate total active power of biggest Island network. Each times 
identifying the transmission lines connected to a bus and mention them to 
remove a bus is quite tidious job. If is thier any process in matpower to 
directly remove a bus along with its branches then it can help me atleast.

On 6 Dec 2021 21:07, Ray Daniel Zimmerman 
mailto:r...@cornell.edu>> wrote:
You’ve got the right idea. You can simply set the branch status to 0 and then 
use find_islands() and to f

Re: Removing a bus with its branch

[prem panigrahi]

Dear Ray sir    Yes you are right. I am facing problem during automate the process. Actually I need to remove approx.. 400 buses, and each time after removal I need to calculate total active power of biggest Island network. Each times identifying the transmission lines connected to a bus and mention them to remove a bus is quite tidious job. If is thier any process in matpower to directly remove a bus along with its branches then it can help me atleast. On 6 Dec 2021 21:07, Ray Daniel Zimmerman  wrote:
You’ve got the right idea. You can simply set the branch status to 0 and then use
find_islands() and to find the isolated buses and set their
BUS_TYPE  to NONE (4). You may then be left with multiple islands, also found via find_islands() or extract_islands().
 To solve a power flow, each island needs its own reference bus (which may have been eliminated even for the main system). The load / generation mismatch could also be potential very large in some islands, and that would show up in the slack generation (negative,
 or unreasonably large positive).


So I think the main challenge in automating everything is in selecting a new reference bus for islands without one. I’d probably go with the first PV bus, and if there are no PV buses, then that whole island blacks out and you can set all its
 buses to type NONE.



Hope this helps,


   Ray






On Dec 4, 2021, at 12:58 PM, prem panigrahi <prempanigr...@outlook.com> wrote:




Dear Ray sir, is their any direct process to remove bus along with their branches . I am using mpc.branch method to remove a bus with its branches. But I am facing difficulties when I have to remove more than 100 buses.



mpc.branch([6161;7479;7480;7488;7489;7490], BR_STATUS) = 0;



results=rundcpf(mpc,opt)



[groups, isolated] = find_islands(mpc)



mpc_list = extract_islands(mpc)



[GROUPS, ISOLATED] = case_info(mpc)



mpc.bus([ISOLATED],BUS_TYPE)=4



results=rundcpf(mpc,opt)



 

Sent from Mail for Windows

Removing a bus with its branch

[prem panigrahi]

Dear Ray sir, is their any direct process to remove bus along with their 
branches . I am using mpc.branch method to remove a bus with its branches. But 
I am facing difficulties when I have to remove more than 100 buses.
mpc.branch([6161;7479;7480;7488;7489;7490], BR_STATUS) = 0;
results=rundcpf(mpc,opt)
[groups, isolated] = find_islands(mpc)
mpc_list = extract_islands(mpc)
[GROUPS, ISOLATED] = case_info(mpc)
mpc.bus([ISOLATED],BUS_TYPE)=4
results=rundcpf(mpc,opt)

Sent from Mail for Windows

Re: DCOPF not converging for large system

[prem panigrahi]

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 -
fixed2227
dispatchable-
  on-
  off   -
  generators  979
on979
off -
  shunt elements  247
  branches   8096
on   8096
off -
ties (off)  -

Load
  active (MW)
dispatched  85879.4
  fixed 85879.4
  dispatchable  -
nominal 85879.4
  on85879.4
  off   -
  fixed 85879.4
  dispatchable  -
on  -
off -
  reactive (MVAr)
dispatched  23668.6
  fixed 23668.6
  dispatchable  -
nominal 23668.6
  on23668.6
  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 capacity69809.7
  on69809.7
  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 numbers3292



From: bounce-121637002-78651...@list.cornell.edu 
 on behalf of Ray Zimmerman 

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 
> 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]

Re: load2disp command

[prem panigrahi]

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 -
fixed2227
dispatchable-
  on-
  off   -
  generators  979
on979
off -
  shunt elements  247
  branches   8096
on   8096
off -
ties (off)  -

Load
  active (MW)
dispatched  85879.4
  fixed 85879.4
  dispatchable  -
nominal 85879.4
  on85879.4
  off   -
  fixed 85879.4
  dispatchable  -
on  -
off -
  reactive (MVAr)
dispatched  23668.6
  fixed 23668.6
  dispatchable  -
nominal 23668.6
  on23668.6
  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 capacity69809.7
  on69809.7
  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 numbers3292






From: bounce-121661719-78651...@list.cornell.edu 
 on behalf of Ray Zimmerman 

Sent: Monday, July 17, 2017 8:05:10 PM
To: MATPOWER discussion forum
Subject: Re: load2disp command

Did you check the help for the function (e.g. 
load2disp
 in the online function reference)?

idx is simply a vector of bus indexes, in your case it should be simply be 
equal to 2 (a 1 x 1 vector).

   Ray




On Jul 17, 2017, at 2:29 AM, Akash Tyagi 
> wrote:

Hello everyone,
I am using load2disp command and I understand everything in that command except 
the input index.
Suppose I want to convert the fixed load to dispatchable load at bus 2 only.
I tried by using the following command-
clc
clear
close all;
define_constants;
mpc0=loadcase(case5a);
idx1=mpc0.bus([2,3],PD);
mpc1=load2disp(mpc0,'Akash',idx1);
It is not working?
Thanks in advance

Re: DCOPF not converge

[prem panigrahi]

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 <prempanigr...@outlook.com>
Sent: Tuesday, June 20, 2017 6:13:37 PM
To: matpowe...@list.cornell.edu
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:   --  --  --  --  -- 
  buses57  45   3   3   2   
  loads42  35   2   1   2   
on 42  35   2   1   2   
off -   -   -   -   -   
fixed  42  35   2   1   2   
dispatchable-   -   -   -   -   
  on-   -   -   -   -   
  off   -   -   -   -   -   
  generators7   7   -   -   -   
on  7   7   -   -   -   
off -   -   -   -   -   
  shunt elements3   2   1   -   -   
  branches 80  59   3   2   1   
on 61  55   3   2   1   
off19   4   -   -   -   
ties (off) 14  12   4   3   2   

Load
  active (MW)   
dispatched   1375.9  1321.933.6 2.5 5.9 
  fixed  1375.9  1321.933.6 2.5 5.9 
  dispatchable  -   -   -   -   -   
nominal  1375.9  1321.933.6 2.5 5.9 
  on 1375.9  1321.933.6 2.5 5.9 
  off   -   -   -   -   -   
  fixed  1375.9  1321.933.6 2.5 5.9 
  dispatchable  -   -   -   -   -   
on  -   -   -   -   -   
off -   -   -   -   -   
  reactive (MVAr)   
dispatched336.4   317.510.4 1.0 2.7 
  fixed   336.4   317.510.4 1.0 2.7 
  dispatchable  -   -   -   -   -   
nominal   336.4   317.510.4 1.0 2.7 
  on  336.4   317.510.4 1.0 2.7 
  off   -   -   -   -   -   
  fixed   336.4   317.510.4 1.0 2.7 
  dispatchable  -   -   -   -   -   
on  -   -   -   -   -   
off -   -   -   -   -   

Generation  
  active (MW)   
dispatched928.9  

DCOPF not converge

[prem panigrahi]

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? .