Dear Dr. Ray
 
Thanks very much for your support. I made use of the case file that you has 
sent me and I have changed the values of BR_R and BR_X to per unit values 
dividing them by Zbase and then the program converges after 5 iterations and I 
think the results are reasonable. I will try to run optimal power flow. 
 Thanks 

Amal Elramly

 

________________________________
 From: Ray Zimmerman <[email protected]>
To: MATPOWER discussion forum <[email protected]> 
Sent: Wednesday, November 28, 2012 6:16 PM
Subject: Re: question
  

Ok, I spent some time trying to get to something that converges …

- there is no reference bus (set bus type to 3 for bus 1)
- gencost format is incorrect, it should be polynomial (set first column to 2)
- the bus matrix is missing the VM column

If you fix these issues, then it is a valid, but infeasible problem. I believe 
the infeasibility is related to voltage and reactive power. In case it is 
useful, dividing BR_R by 1000, BR_X by 100 and setting RATE_A to 0 in the 
branch matrix and dividing QD by 10 in the bus matrix, yields a feasible 
problem. This may give you a useful starting point for this topology from which 
to begin investigating where the unfeasibility comes from.

-- 
Ray Zimmerman
Senior Research Associate
419A Warren Hall, Cornell University, Ithaca, NY 14853
phone: (607) 255-9645


 

On Nov 28, 2012, at 3:47 AM, Amal Elramly <[email protected]> wrote:

Dr. Ray
> 
>yes all lines have non-zero reactance 
>The case file of the test bus system is attached below:
> system MVA basempc.baseMVA = 1;
>%% bus data
>%   bus_i   type    Pd  Qd  Gs  Bs      Vm  Va  baseKV  zone    Vmax    
>Vminmpc.bus = [
>1   2   0       0       0   0       1   0   12.6    1   1.05    0.95;
>2   1   0.1     0.06    0   0       1   0   12.6    1   1.1     0.95;
>3   1   0.09    0.04    0   0       1   0   12.6    1   1.05    0.95;
>4   1   0.12    0.08    0   0       1   0   12.6    1   1.05    0.95;
>5   1   0.06    0.03    0   0       1   0   12.6    1   1.05    0.95;
>6   1   0.06    0.02    0   0       1   0   12.6    1   1.05    0.95;
>7   1   0.2     0.1     0   0       1   0   12.6    1   1.05    0.95;
>8   1   0.2     0.1     0   0       1   0   12.6    1   1.05    0.95;
>9   1   0.06    0.02    0   0       1   0   12.6    1   1.05    0.95;
>10  1   0.06    0.02    0   0       1   0   12.6    1   1.05    0.95;
>11  1   0.045   0.03    0   0       1   0   12.6    1   1.05    0.95;
>12  1   0.06    0.035   0   0       1   0   12.6    1   1.05    0.95;
>13  1   0.06    0.035   0   0       1   0   12.6    1   1.1     0.95;
>14  1   0.12    0.08    0   0       1   0   12.6    1   1.05    0.95;
>15  1   0.06    0.01    0   0       1   0   12.6    1   1.05    0.95;
>16  1   0.06    0.02    0   0       1   0   12.6    1   1.05    0.95;
>17  1   0.06    0.02    0   0       1   0   12.6    1   1.05    0.95;
>18  1   0.09    0.04    0   0       1   0   12.6    1   1.05    0.95;
>19  1   0.09    0.04    0   0       1   0   12.6    1   1.05    0.95;
>20  1   0.09    0.04    0   0       1   0   12.6    1   1.05    0.95;
>21  1   0.09    0.04    0   0       1   0   12.6    1   1.05    0.95;
>22  1   0.09    0.04    0   0       1   0   12.6    1   1.1     0.95;
>23  1   0.42    0.05    0   0       1   0   12.6    1   1.1     0.95;
>24  1   0.42    0.2     0   0       1   0   12.6    1   1.05    0.95;
>25  1   0.06    0.2     0   0       1   0   12.6    1   1.05    0.95;
>26  1   0.06    0.025   0   0       1   0   12.6    1   1.05    0.95;
>27  1   0.06    0.025   0   0       1   0   12.6    1   1.1     0.95;
>28  1   0.12    0.02    0   0       1   0   12.6    1   1.05    0.95;
>29  1   0.2     0.07    0   0       1   0   12.6    1   1.05    0.95;
>30  1   0.15    0.6     0   0       1   0   12.6    1   1.05    0.95;
>31  1   0.21    0.07    0   0       1   0   12.6    1   1.05    0.95;
>32  1   0.06    0.1     0   0       1   0   12.6    1   1.05    0.95;
>33  1   0.06    0.04    0   0       1   0   12.6    1   1.05    0.95;
>];
>%% generator data
>%   bus Pg  Qg  Qmax    Qmin    Vg  mBase   status  Pmax    Pmin    Pc1 Pc2 
>Qc1min  Qc1max  Qc2min  Qc2max  ramp_agc    ramp_10 ramp_30 ramp_q  apfmpc.gen 
>= [
>1   0.5 0   1   -0.5    1   100 1   6   0   0   0   0   0   0   0   0   0   0  
> 0   0;
>];%% branch data
>%   fbus    tbus    r   x   b   rateA   rateB   rateC   ratio   angle   status 
> angmin  angmaxmpc.branch = [
>1   2   0.0922   0.0477   0     0.2 0.2 0.2 0   0   1   -360    360;
>2   3   0.493    0.2511   0     0.1 0.1 0.1 0   0   1   -360    360;
>3   4   0.3660   0.1864   0     0.2 0.2 0.2 0   0   1   -360    360;
>4   5   0.3811   0.1941   0     0.1 0.1 0.1 0   0   1   -360    360;
>5   6   0.8190   0.7070   0     0.1 0.1 0.1 0   0   1   -360    360;
>6   7   0.1872   0.6188   0     0.3 0.3 0.3 0   0   1   -360    360;
>7   8   1.7114   1.2351   0     0.3 0.3 0.3 0   0   1   -360    360; 
>8   9   1.0300   0.7400   0     0.1 0.1 0.1 0   0   1   -360    360; 
>9   10  1.0040   0.7400   0     0.1 0.1 0.1 0   0   1   -360    360; 
>10  11  0.1966   0.0650   0     0.1 0.1 0.1 0   0   1   -360    360; 
>11  12  0.3744   0.1238   0     0.1 0.1 0.1 0   0   1   -360    360; 
>12  13  1.4680   1.1550   0     0.1 0.1 0.1 0   0   1   -360    360; 
>13  14  0.5416   0.7129   0     0.2 0.2 0.2 0   0   1   -360    360; 
>14  15  0.5910   0.5260   0     0.1 0.1 0.1 0   0   1   -360    360; 
>15  16  0.7463   0.5450   0     0.1 0.1 0.1 0   0   1   -360    360; 
>16  17  1.2890   1.7210   0     0.1 0.1 0.1 0   0   1   -360    360; 
>17  18  0.7320   0.5740   0     0.1 0.1 0.1 0   0   1   -360    360; 
>2   19  0.1640   0.1565   0     0.1 0.1 0.1 0   0   1   -360    360; 
>19  20  1.5042   1.3554   0     0.1 0.1 0.1 0   0   1   -360    360; 
>20  21  0.4095   0.4784   0     0.1 0.1 0.1 0   0   1   -360    360; 
>21  22  0.7089   0.9373   0     0.1 0.1 0.1 0   0   1   -360    360; 
>3   23  0.4512   0.3083   0     0.5 0.5 0.5 0   0   1   -360    360; 
>23  24  0.8980   0.7091   0     0.5 0.5 0.5 0   0   1   -360    360; 
>24  25  0.8960   0.7011   0     0.3 0.3 0.3 0   0   1   -360    360; 
>6   26  0.2030   0.1034   0     0.1 0.1 0.1 0   0   1   -360    360; 
>26  27  0.2842   0.1447   0     0.1 0.1 0.1 0   0   1   -360    360; 
>27  28  1.0590   0.9337   0     0.2 0.2 0.2 0   0   1   -360    360; 
>28  29  0.8042   0.7006   0     0.3 0.3 0.3 0   0   1   -360    360; 
>29  30  0.5075   0.2585   0     0.7 0.7 0.7 0   0   1   -360    360; 
>30  31  0.9744   0.9630   0     0.3 0.3 0.3 0   0   1   -360    360; 
>31  32  0.3105   0.3619   0     0.2 0.2 0.2 0   0   1   -360    360; 
>32  33  0.3410   0.5302   0     0.1 0.1 0.1 0   0   1   -360    360;
>];
>%%generator cost datampc.gencost = [
>1   0   0   3   0.02    2   0;
>];
>
>Amal Elramly
>
> 
>
>________________________________
> From: Ray Zimmerman <[email protected]>
>To: MATPOWER discussion forum <[email protected]> 
>Sent: Tuesday, November 27, 2012 4:52 PM
>Subject: Re: question
>  
>
>Do all lines have non-zero reactance? Do you have a reference bus?
>
>
>-- 
>Ray Zimmerman
>Senior Research Associate
>419A Warren Hall, Cornell University, Ithaca, NY 14853
>phone: (607) 255-9645
>
>
> 
>
>On Nov 27, 2012, at 3:20 AM, Amal Elramly <[email protected]> wrote:
>
> 
>> 
>>I have run power flow for 33 radial test bus system, but the it doesn't 
>>converge and I do not know what is the problem
>>could you help me ?
>>Attached below the results of the program:
>> 
>> 
>>MATPOWER Version 4.1, 14-Dec-2011 -- AC Power Flow (Newton)
>>Warning: Matrix is singular to working precision. 
>>> In newtonpf at 109
>>  In runpf at 220
>>Warning: Matrix is singular
 to working precision. 
>>> In newtonpf at 109
>>  In runpf at 220
>>Warning: Matrix is singular to working precision. 
>>> In newtonpf at 109
>>  In runpf at 220
>>Warning: Matrix is singular to working precision. 
>>> In newtonpf at 109
>> 
 In runpf at 220
>>Warning: Matrix is singular to working precision. 
>>> In newtonpf at 109
>>  In runpf at 220
>>Warning: Matrix is singular to working precision. 
>>> In newtonpf at 109
>>  In runpf at 220
>>Warning: Matrix is singular to working precision. 
>>
>>Newton's method power did not converge in 10 iterations.
>>Did not converge (0.09 seconds)
>>================================================================================
>>|     System Summary                                                          
 |
>>================================================================================
>>How many?                How much?              P (MW)            Q (MVAr)
>>---------------------    -------------------  -------------  -----------------
>>Buses             33     Total Gen Capacity       6.0          -0.5 to 1.0
>>Generators         1     On-line Capacity         6.0          -0.5 to 1.0
>>Committed
 Gens     1     Generation (actual)      NaN               NaN
>>Loads             32     Load                     3.7               2.3
>>  Fixed           32       Fixed                  3.7               2.3
>>  Dispatchable     0      
 Dispatchable          -0.0 of -0.0      -0.0
>>Shunts             0     Shunt (inj)             -0.0               0.0
>>Branches          32     Losses (I^2 * Z)          NaN               NaN
>>Transformers       0     Branch Charging (inj)     -                NaN
>>Inter-ties         0    
 Total Inter-tie Flow     0.0               0.0
>>Areas              1
>>                          Minimum                      Maximum
>>                 -------------------------  --------------------------------
>>Voltage Magnitude     NaN p.u. @ bus 1            NaN p.u. @ bus 1   
>>Voltage Angle        NaN deg   @ bus
 1           NaN deg   @ bus 1   
>>P Losses (I^2*R)             -                   NaN MW    @ line 1-2
>>Q Losses (I^2*X)             -                   NaN MVAr  @ line 1-2
>>================================================================================
>>|     Bus
 Data                                                                 |
>>================================================================================
>> Bus      Voltage          Generation             Load        
>>  #   Mag(pu) Ang(deg)   P (MW)   Q (MVAr)   P (MW)   Q (MVAr)
>>----- ------- --------  --------  --------  --------  --------
>>    1   
 NaN      NaN       NaN       NaN       -         -   
>>    2    NaN      NaN       -         -        0.10      0.06 
>>    3    NaN      NaN       -         -        0.09      0.04 
>>    4    NaN      NaN       -         -        0.12     
 0.08 
>>    5    NaN      NaN       -         -        0.06      0.03 
>>    6    NaN      NaN       -         -        0.06      0.02 
>>    7    NaN      NaN       -         -        0.20      0.10 
>>    8    NaN      NaN       -        
 -        0.20      0.10 
>>    9    NaN      NaN       -         -        0.06      0.02 
>>   10    NaN      NaN       -         -        0.06      0.02 
>>   11    NaN      NaN       -         -        0.04      0.03 
>>   12    NaN      NaN      
 -         -        0.06      0.04 
>>   13    NaN      NaN       -         -        0.06      0.04 
>>   14    NaN      NaN       -         -        0.12      0.08 
>>   15    NaN      NaN       -         -        0.06      0.01 
>>   16    NaN     
 NaN       -         -        0.06      0.02 
>>   17    NaN      NaN       -         -        0.06      0.02 
>>   18    NaN      NaN       -         -        0.09      0.04 
>>   19    NaN      NaN       -         -        0.09      0.04 
>>   20   
 NaN      NaN       -         -        0.09      0.04 
>>   21    NaN      NaN       -         -        0.09      0.04 
>>   22    NaN      NaN       -         -        0.09      0.04 
>>   23    NaN      NaN       -         -        0.42      0.05 
>>  
 24    NaN      NaN       -         -        0.42      0.20 
>>   25    NaN      NaN       -         -        0.06      0.20 
>>   26    NaN      NaN       -         -        0.06      0.03 
>>   27    NaN      NaN       -         -        0.06      0.03 
>>   28    NaN      NaN       -         -        0.12      0.02 
>>   29    NaN      NaN       -         -        0.20      0.07 
>>   30    NaN      NaN       -         -        0.15      0.60 
>>   31    NaN      NaN       -         -       
 0.21      0.07 
>>   32    NaN      NaN       -         -        0.06      0.10 
>>   33    NaN      NaN       -         -        0.06      0.04 
>>                        --------  --------  --------  --------
>>               Total:       NaN       NaN     
 3.69      2.30
>>================================================================================
>>|     Branch 
>>Data                                                              |
>>================================================================================
>>Brnch   From   To    From Bus Injection   To Bus Injection     Loss (I^2 * 
>>Z)  
>>  #     Bus    Bus    P (MW)   Q (MVAr)   P (MW)   Q (MVAr)   P (MW)   Q
 (MVAr)
>>-----  -----  -----  --------  --------  --------  --------  --------  
>>--------
>>   1      1      2       NaN       NaN       NaN       NaN       NaN       NaN
>>   2      2      3       NaN       NaN       NaN       NaN       NaN       NaN
>>   3      3      4       NaN      
 NaN       NaN       NaN       NaN       NaN
>>   4      4      5       NaN       NaN       NaN       NaN       NaN       NaN
>>   5      5      6       NaN       NaN       NaN       NaN       NaN       NaN
>>   6      6      7       NaN      
 NaN       NaN       NaN       NaN       NaN
>>   7      7      8       NaN       NaN       NaN       NaN       NaN       NaN
>>   8      8      9       NaN       NaN       NaN       NaN       NaN       NaN
>>   9      9     10       NaN      
 NaN       NaN       NaN       NaN       NaN
>>  10     10     11       NaN       NaN       NaN       NaN       NaN       NaN
>>  11     11     12       NaN       NaN       NaN       NaN       NaN       NaN
>>  12     12     13       NaN       NaN      
 NaN       NaN       NaN       NaN
>>  13     13     14       NaN       NaN       NaN       NaN       NaN       NaN
>>  14     14     15       NaN       NaN       NaN       NaN       NaN       NaN
>>  15     15     16       NaN       NaN       NaN      
 NaN       NaN       NaN
>>  16     16     17       NaN       NaN       NaN       NaN       NaN       NaN
>>  17     17     18       NaN       NaN       NaN       NaN       NaN       NaN
>>  18      2     19       NaN       NaN       NaN       NaN      
 NaN       NaN
>>  19     19     20       NaN       NaN       NaN       NaN       NaN       NaN
>>  20     20     21       NaN       NaN       NaN       NaN       NaN       NaN
>>  21     21     22       NaN       NaN       NaN       NaN       NaN      
 NaN
>>  22      3     23       NaN       NaN       NaN       NaN       NaN       NaN
>>  23     23     24       NaN       NaN       NaN       NaN       NaN       NaN
>>  24     24     25       NaN       NaN       NaN       NaN       NaN       NaN
>> 
 25      6     26       NaN       NaN       NaN       NaN       NaN       NaN
>>  26     26     27       NaN       NaN       NaN       NaN       NaN       NaN
>>  27     27     28       NaN       NaN       NaN       NaN       NaN       NaN
>>  28    
 28     29       NaN       NaN       NaN       NaN       NaN       NaN
>>  29     29     30       NaN       NaN       NaN       NaN       NaN       NaN
>>  30     30     31       NaN       NaN       NaN       NaN       NaN       NaN
>>  31     31    
 32       NaN       NaN       NaN       NaN       NaN       NaN
>>  32     32     33       NaN       NaN       NaN       NaN       NaN       NaN
>>                                                             -------- 
 --------
>>                                                    Total:       NaN       NaN
>>
>>
>>Amal Elramly
>>
>>
>> 
>
>
>  

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