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Operation of the load flow for isolated sections - MATPOWER
Good afternoon people! By performing load flow tests in IEEE radials feeders
cases,
such as 33, 69, 84 bars, I noticed that the study does not work when I leave
isolated
sections (eg in the case 33 buses, runpf('case33'), opening section 3-23 causes
error). Is there any
way in MATPOWER to perform load flow tests with isolated branches?
Opening and closing switches within IEEE radials systems (case33, case69, etc) - MATPOWER
Good morning people!! My name's Andrey Vieira. I am a PhD student in Belém -
Brazil (amazon) in the area of energy systems at PPGEE-UFPA. I intend to
develop my thesis in the area of optimization for restoration of electric
energy distribution systems with some goals and restrictions. My purpose is to
develop an intelligent algorithm that performs a configuration in Electric
Power Distribution Systems for the problem of restoration in both literature
feeders and in the most complex (real), three-phase and unbalanced radial, with
a multiobjective approach and with time requirements real.
I have read several papers on the subject and intend to use MATPOWER to
optimize the reconfiguration on some IEEE feeders (16,33 and 84 bars).
Currently, I am starting programming and I have come up against a simple
question regarding the manipulation of the (normally open and normally closed)
IEEE cases of matlab (case33, case69, case84, etc), ie: How to manipulate the
(Normally closed sections) and those to be closed for analysis (TIE keys)?
Anyway, the reason for my contact is to know if anyone can help me regarding
the switchings in the MATPOWER IEEE case files. That is, how do I manipulate
(change the state of the keys)? For example, in the case of 33 bars, in the
initial configuration, TIE keys are part of the initial configuration of the
system. I do not know if I'm getting it wrong, but when running load (runpf
('case33')), whether or not you have the 5 TIE keys inserted in the case33
files, the result is always the same. I know I must be making a mistake, I just
do not know what it is. I would appreciate the help.
"A Segurança econômica não se encontra no emprego, mas sim em seu próprio poder
de produzir - pensar, criar, aprender, adaptar. Esta é a verdadeira
independência financeira, e não a posse de riquezas. É ter poder para produzir
riquezas. É algo interno"
(Stephen Covey).
De: bounce-121060554-77188...@list.cornell.edu
em nome de Ray Bo
Enviado: terça-feira, 6 de dezembro de 2016 07:35
Para: MATPOWER discussion forum
Assunto: Re: state estimation: active power not balanced in test cases
Hi Ray,
Sure I will take care of it.
Niccolò,
As I don't have 6.02b2 right now, I did a quick check on v5.1, and did see
the issue you brought up. The state estimation results are actually
correctly presented in the last section of the screen output, where you can
see the Pg2=0.3034 pu, Pg3=0.1336 pu. So the gen, load and losses are
balanced. The Pg2 and Pg3 values you see in the 'Generator Data' output
section are actually the default values from the 3-bus case, and appear to
be inbalanced with load. The reason Pg2 and Pg3 values do not get updated in
the 'Generator Data' output section is that, to output the power flow
solution in a nice format, I simply took advantage of the MATPOWER function
'pfsoln' to update bus, gen, branch data structures to match power flow
solution. This function however only updates Pg for the slack bus generator
and not for the rest of the generators (because those are PQ and PV buses
and there is no need to do it).
To clean up the output to avoid such confusion, I have implemented a quick
fix for the issue by updating the Pg and Qg using state estimation results.
The code with the quick fix is attached. I haven't tested it extensively.
Please use it and let me know if you find it useful or if you have
additional questions. I can be reached at rui...@ieee.org.
Thanks,
Rui
-Original Message-
From: Ray Zimmerman
Sent: Monday, December 5, 2016 9:27 AM
To: Rui Bo
Cc: MATPOWER discussion forum
Subject: Re: state estimation: active power not balanced in test cases
Hi Rui and Niccolò,
The state estimation code was contributed by Rui Bo, so I'm not that
familiar with it. Rui, I was wondering if you might be able to address
Niccolò's questions.
Thanks,
Ray
> On Dec 1, 2016, at 6:20 PM, Niccolò Citroni
> wrote:
>
> Hallo, I'm new to matpower, using it for my master thesis.
> I'm trying to figure out how the se program works, and running the
> included test cases I noticed the following:
> there is a big unbalance in active power in the network, for example in
> the 3 bus case there are more than 380 MW of active power in excess,
> considering generation, load, and losses. How is that possible?
> Another thing: modifing the load i get different results runnning the se.
> Why is that? shouldn't the state estimation be based only on the input
> mesurements and the topology of the network? How has the load and
> generator power anything to do with the se, when not included in the
> mesurements? From what I know the power balance at each node should be a
> result of the se, not part of the input data (when not as mesurements of
> course).
> I hope I've been clear enough.
> I'm using version 6.0b2
> Thankyou for the help and the program.
> Niccolò Citroni
Re: Opening and closing switches within IEEE radials systems (case33, case69, etc) - MATPOWER
Thank you! Mr Ray
De: bounce-121061376-77188...@list.cornell.edu
em nome de Ray Zimmerman
Enviado: terça-feira, 6 de dezembro de 2016 14:59
Para: MATPOWER discussion forum
Assunto: Re: Opening and closing switches within IEEE radials systems (case33,
case69, etc) - MATPOWER
In MATPOWER, which uses a bus/branch model, you can use the BR_STATUS column of
the branch matrix to indicate whether a particular branch is in-service or
out-of-service.
Ray
On Dec 6, 2016, at 8:26 AM, Andrey Vieira
mailto:andre...@hotmail.com>> wrote:
Good morning people!! My name's Andrey Vieira. I am a PhD student in Belém -
Brazil (amazon) in the area of energy systems at PPGEE-UFPA. I intend to
develop my thesis in the area of optimization for restoration of electric
energy distribution systems with some goals and restrictions. My purpose is to
develop an intelligent algorithm that performs a configuration in Electric
Power Distribution Systems for the problem of restoration in both literature
feeders and in the most complex (real), three-phase and unbalanced radial, with
a multiobjective approach and with time requirements real.
I have read several papers on the subject and intend to use MATPOWER to
optimize the reconfiguration on some IEEE feeders (16,33 and 84 bars).
Currently, I am starting programming and I have come up against a simple
question regarding the manipulation of the (normally open and normally closed)
IEEE cases of matlab (case33, case69, case84, etc), ie: How to manipulate the
(Normally closed sections) and those to be closed for analysis (TIE keys)?
Anyway, the reason for my contact is to know if anyone can help me regarding
the switchings in the MATPOWER IEEE case files. That is, how do I manipulate
(change the state of the keys)? For example, in the case of 33 bars, in the
initial configuration, TIE keys are part of the initial configuration of the
system. I do not know if I'm getting it wrong, but when running load (runpf
('case33')), whether or not you have the 5 TIE keys inserted in the case33
files, the result is always the same. I know I must be making a mistake, I just
do not know what it is. I would appreciate the help.
"A Segurança econômica não se encontra no emprego, mas sim em seu próprio poder
de produzir - pensar, criar, aprender, adaptar. Esta é a verdadeira
independência financeira, e não a posse de riquezas. É ter poder para produzir
riquezas. É algo interno"
(Stephen Covey).
Re: Operation of the load flow for isolated sections - MATPOWER
Thanks Mr Ray!!
De: bounce-121085121-77188...@list.cornell.edu
em nome de Ray Zimmerman
Enviado: quarta-feira, 14 de dezembro de 2016 17:56
Para: MATPOWER discussion forum
Assunto: Re: Operation of the load flow for isolated sections - MATPOWER
I'm not sure I understand the question ... extract_islands() creates the mpc of
each island for you.
Ray
On Dec 13, 2016, at 2:27 PM, Andrey Vieira
mailto:andre...@hotmail.com>> wrote:
Thank you, Mr. Ray. How should I proceed with the insertion of the islands? For
example in case 33 buses, I will extract the subsystems from bar 2 to 22
(branches: 2-19 ; 19-20; 20-21 and 21-22). How would the mpc matrix be for such
a situation?
De:
bounce-121080169-77188...@list.cornell.edu<mailto:bounce-121080169-77188...@list.cornell.edu>
mailto:bounce-121080169-77188...@list.cornell.edu>>
em nome de Ray Zimmerman mailto:r...@cornell.edu>>
Enviado: terça-feira, 13 de dezembro de 2016 13:48
Para: MATPOWER discussion forum
Assunto: Re: Operation of the load flow for isolated sections - MATPOWER
If the isolated portions have adequate generation to operate as an island, then
the only thing necessary is to make sure that each island has its own reference
bus. In your case, however, I suppose there are de-energized sections. MATPOWER
does not automatically handle the de-energized sections, so you will have to
extract the section that is still live using
extract_islands()<http://www.pserc.cornell.edu//matpower/docs/ref/matpower6.0b2/extract_islands.html>,
then only run the power flow on that island.
Ray
On Dec 12, 2016, at 2:33 PM, Andrey Vieira
mailto:andre...@hotmail.com>> wrote:
Good afternoon people! By performing load flow tests in IEEE radials feeders
cases,
such as 33, 69, 84 bars, I noticed that the study does not work when I leave
isolated
sections (eg in the case 33 buses, runpf('case33'), opening section 3-23 causes
error). Is there any
way in MATPOWER to perform load flow tests with isolated branches?
Re: Operation of the load flow for isolated sections - MATPOWER
Thank you, Mr. Ray. How should I proceed with the insertion of the islands? For
example in case 33 buses, I will extract the subsystems from bar 2 to 22
(branches: 2-19 ; 19-20; 20-21 and 21-22). How would the mpc matrix be for such
a situation?
De: bounce-121080169-77188...@list.cornell.edu
em nome de Ray Zimmerman
Enviado: terça-feira, 13 de dezembro de 2016 13:48
Para: MATPOWER discussion forum
Assunto: Re: Operation of the load flow for isolated sections - MATPOWER
If the isolated portions have adequate generation to operate as an island, then
the only thing necessary is to make sure that each island has its own reference
bus. In your case, however, I suppose there are de-energized sections. MATPOWER
does not automatically handle the de-energized sections, so you will have to
extract the section that is still live using
extract_islands()<http://www.pserc.cornell.edu//matpower/docs/ref/matpower6.0b2/extract_islands.html>,
then only run the power flow on that island.
Ray
On Dec 12, 2016, at 2:33 PM, Andrey Vieira
mailto:andre...@hotmail.com>> wrote:
Good afternoon people! By performing load flow tests in IEEE radials feeders
cases,
such as 33, 69, 84 bars, I noticed that the study does not work when I leave
isolated
sections (eg in the case 33 buses, runpf('case33'), opening section 3-23 causes
error). Is there any
way in MATPOWER to perform load flow tests with isolated branches?
I need the Case of 16 buses (case16.m)
Good morning people! Does anyone have the 16 case buses file(case16.m) ? Can you send me?
Fault and Protection analysis for reconfiguration and restoration of the Radial distribution feeders
Dear all and Mr Ray I am developing optimization studies (evolutionary algorithms) in reconfiguration and restoration in distribution systems in the first part of my thesis. For this, I'm basically using MATPOWER's runpf function for cases 33, 84 and 135 buses to analyze losses, voltage drops, and so on. In the second part, I intend to involve studies and protection analysis between protection devices (relays, fuses and reclosers) for such cases. For this, I need to conduct short-circuit studies and MATPOWER does not offer me such a tool. I wonder if some of you have had to deal with this situation. That is, is there any MATPOWER routine available for short-circuit studies? Can anyone tell me how I can do short-circuit studies in cases 33, 84 and 135? Or do I have to associate MATPOWER with some software to do such a study? Att Andrey R Vieira
How to indicate in MATPOWER the use of several substations in the cases of radial distribution systems?
Hi All! I have a question about the use of several substation bars in the case of radial distribution systems with more than one substation. Examples: A) Case 16 buses : it has 3 substations; B) Case 135 buses: it has 2 substations; C) Case 84 buses : it has 11 substations. In the case of 84 buses, for example, can I identify all substation buses with different numberings and indicate that all 11 buses are of type 3 in the mpc.bus matrix? Instead of numbering all 11 with the same number (1 for exemplo)? Can anybody advice on representation these sources in MATPOWER? Andrey R Vieira
Re: How to indicate in MATPOWER the use of several substations in the cases of radial distribution systems?
Mr. Ray, that's exactly it. I will try to exemplify the question again using the 16 buses radial system. In this system, there are 3 bars (3 substations) that provide the power for the entire electrical network. This system consists of three feeders. With this, there is one substation for each feeder. [cid:75f08e88-f6da-460a-8a51-83b014a765ec] My question is can I consider all the substation bars (1,2 and 3) as generation bars (PV)? For this consideration, the radial system will be considered as a meshed system. See example below. With this, the radial distribution system of 16 buses will be considered as a meshed system. With this, the results will be affected? %% bus data % bus type Pd Qd Gs Bs area Vm Va baseKV zone Vmax Vmin mpc.bus = [ 13 0.0 0.0 0 0 11.00 0 11 1 1.05 0.950; 23 0.0 0.0 0 0 11.00 0 11 1 1.05 0.950; 33 0.0 0.0 0 0 11.00 0 11 1 1.05 0.950; 41 2.0 1.6 0 0 11.00 0 11 1 1.05 0.950; 51 3.0 1.5 0 1.1 11.00 0 11 1 1.05 0.950; 61 2.0 0.8 0 1.2 11.00 0 11 1 1.05 0.950; 71 1.5 0.2 0 0 11.00 0 11 1 1.05 0.950; 81 4.0 2.7 0 0 11.00 0 11 1 1.05 0.950; 91 5.0 3.0 0 1.2 11.00 0 11 1 1.05 0.950; 101 1.0 0.9 0 0 11.00 0 11 1 1.05 0.950; 111 0.6 0.1 0 0.6 11.00 0 11 1 1.05 0.950; 121 4.5 2.0 0 3.7 11.00 0 11 1 1.05 0.950; 131 1.0 0.9 0 0 11.00 0 11 1 1.05 0.950; 141 1.0 0.7 0 1.8 1 1.00 0 11 1 1.05 0.950; 151 1.0 0.9 0 01 1.00 0 11 1 1.05 0.950; 161 2.1 1.0 0 1.8 1 1.00 0 11 1 1.05 0.950; ]; Or should I always consider a reference bar (for example, bar 1) and the other two as generation bar (bars 2 and 3)? De: bounce-121569284-77188...@list.cornell.edu em nome de Ray Zimmerman Enviado: terça-feira, 30 de maio de 2017 20:17 Para: MATPOWER discussion forum Assunto: Re: How to indicate in MATPOWER the use of several substations in the cases of radial distribution systems? I’m not sure I understand what you mean by a radial system with more than one substation. You definitely don’t want to set multiple buses of type REF, though you could use type PV for all but one of the substations, but that is equivalent to turning a radial system into a meshed system. Ray On May 26, 2017, at 10:27 AM, Andrey Vieira mailto:andre...@hotmail.com>> wrote: Hi All! I have a question about the use of several substation bars in the case of radial distribution systems with more than one substation. Examples: A) Case 16 buses : it has 3 substations; B) Case 135 buses: it has 2 substations; C) Case 84 buses : it has 11 substations. In the case of 84 buses, for example, can I identify all substation buses with different numberings and indicate that all 11 buses are of type 3 in the mpc.bus matrix? Instead of numbering all 11 with the same number (1 for exemplo)? Can anybody advice on representation these sources in MATPOWER? Andrey R Vieira
MATPOWER Restoration Process
Hi All. I need to work the load flow in the MATPOWER to the bus isolation condition (due to a fault) for the restoration process. I did this by using the extract_islands function. The procedure I did Was as follows: Taking as an example the case16 below: I considered a fault in bar 8, with all the connections this bar were turned off, ie:(2-8), (8-9) and (8-10) were withdrawn to be isolated. To do this, I used The following routine: mpc_array = extract_islands(case16) groups = find_islands(case16) mpc1 = extract_islands(case16, groups, 1) mpc2 = extract_islands(case16, groups, 2) runpf(mpc1) runpf(mpc2) It turns out that my work is an optimization process. I need something somewhat automatic. Does anyone know a more concise way to conduct such a study for any isolated bar? mpc.bus = [ 1 3 0.0. 0 0 1 1.00 0 Vb 11.05 0.950; 2 3 0.0. 0 0 1 1.00 0 Vb 11.05 0.950; 3 3 0.0. 0 0 1 1.00 0 Vb 11.05 0.950; 4 1 2.1.6000 0 0 1 1.00 0 Vb 11.05 0.950; 5 1 3.1.5000 0 1.1 1 1.00 0 Vb 11.050.950; 6 1 2.0.8000 0 1.2 1 1.00 0 Vb 11.05 0.950; 7 1 1.50000.2000 0 0 1 1.00 0 Vb 11.05 0.950; 8 1 4.2.7000 0 0 1 1.00 0 Vb 11.05 0.950; 9 1 5.3. 0 1.2 1 1.00 0 Vb 11.05 0.950; 10 1 1.0.9000 0 0 1 1.00 0 Vb 11.05 0.950; 11 1 0.60000.1000 0 0.6 1 1.00 0 Vb 11.05 0.950; 12 1 4.50002. 0 3.7 1 1.00 0 Vb 11.05 0.950; 13 1 1.0.9000 0 0 1 1.00 0 Vb 11.05 0.950; 14 1 1.0.7000 0 1.8 1 1.00 0 Vb 11.05 0.950; 15 1 1.0.9000 0 0 1 1.00 0 Vb 11.05 0.950; 16 1 2.10001. 0 1.8 1 1.00 0 Vb 11.05 0.950; ]; . . . %% MATRIZ ORIGINAL valors das impedâncias estao em ohms %fbus tbus r x b rateA rateB rateCratioangle statusangminangmax mpc.branch = [ 14 0.0750.10 00 0 0 0 00 -360 360; 45 0.0800.11 00 0 0 0 00 -360 360; 46 0.0900.18 00 0 0 0 00 -360 360; 67 0.0400.04 00 0 0 0 01 -360 360; 28 0.1100.11 00 0 0 0 01 -360 360; 89 0.0800.11 00 0 0 0 01 -360 360; 8 10 0.1100.11 00 0 0 0 00 -360 360; 9 11 0.1100.11 00 0 0 0 01 -360 360; 9 12 0.0800.11 00 0 0 0 01 -360 360; 3 13 0.1100.11 00 0 0 0 01 -360 360; 13 14 0.0900.12 00 0 0 0 01 -360 360; 13 15 0.0800.11 00 0 0 0 01 -360 360; 15 16 0.0400.04 00 0 0 0 01 -360 360; 5 11 0.0400.04 00 0 0 0 01 -360 360; 10 14 0.0400.04 00 0 0 0 01 -360 360; 7 16 0.0900.12 00 0 0 0 01 -360 360; ]; mpc.branch(:,3:4) = mpc.branch(:,3:4)*((mpc.baseMVA)/(Vb.^2)); % Deixa todas as impedâncias na base de % de potência 'mpc.baseMVA' dada em MVA e tensão 'Vb' dada em kV.
Creating the chgtab Matrix in MATPOWER in Case30
Hello All,
I would know for optimization by matlab the following procedure:
I know that savecase() function is used to create a MATPOWER case file from a
case struct. For example, I suppose want to take an existing case file,
say case30.m, and apply a set of changes to it using apply_changes() and
save the result as a new MATPOWER case file called case30new.m. The solution
could to be with the following code …
mpc0 = loadcase('case30');
mpc = apply_changes(label, mpc0, chgtab);
savecase('case30new', mpc);
Now I can use case30new as you would any of the included cases. E.g.
r = runopf('case30new');
What would the chgtab array look like if I wanted to just
delete buses and branches from the case30?
Command for Radial Test systems
Hi All. I would like to know if the new functions added in MATPOWER for load flow in radial distribution systems only work for the following 6 cases: 1. case4_dist 2. case18 3. case22 4. case69 5. case85 6. case141
Re: Command for Radial Test systems
Hi Mr. M. Todorovski, Firstly thank you very much for the answer. I am currently using some MATPOWER cases to perform Studies of optimization in radial distribution systems aiming at Minimizing the number of switches and maximizing the number of consumers After a fault occurs on a given bus or Region of the system. To evaluate the results, I chose the radial cases 16, 84 And 135 of the IEEE. When I evaluated some solutions, I came across With some problems of convergence of the load flow, due to MATPOWER (runpf) use Newton's method and its variants. I noticed that when the number of feeders' buses Increased because of the switching, the probability that the load flow would not Convergence was high. In my research, I have read many papers that suggest that the Backward/Forward Currents SUM method is used for the load flow For radial distribution systems. I noticed that in February of that year Some MATPOWER functions have been inserted for load flow in radial systems Distribution systems that use exactly the method that is suggested for my studies. I know that new functions inserted in MATPOWER only work for the 6 cases already mentioned. I wonder If there is a possibility of change for the radial cases of 16, 84 and 135 buses of the IEEE. De: bounce-121626430-77188...@list.cornell.edu em nome de Mirko Todorovski Enviado: terça-feira, 27 de junho de 2017 21:12 Para: MATPOWER discussion forum Cc: MATPOWER-L@cornell.edu Assunto: Re: Command for Radial Test systems That’s correct. In the current form distribution power flow methods solve only radial systems with or without distributed generation at some buses. The 6 cases you mentioned are all radial. If you try to solve other case you will get an error stating that there are loops in the network and it can't be solved. I hope that soon I'll be able to extend the solvers so that they can solve weakly meshed distribution networks. Best regards, Mirko On Tue, 2017-06-27 at 20:39 +, Andrey Vieira wrote: > Hi All. I would like to know if the new functions added in MATPOWER > for load flowin radial distribution systems only work for the > following 6 cases: > 1. case4_dist > 2. case18 > 3. case22 > 4. case69 > 5. case85 > 6. case141 > >
Power Flow for Radial Test Systems with several Feeders
Hi All. With regard to the use of load flow for radial networks, I would like to know if there is for distribution systems with several separately represented radial feeders. That is, each one With their respective sources (substations). For example, note the case 16 buses below [cid:1d225046-6652-4dd9-a8bc-c7bd6722849e] This case can be represented in MATPOWER in two different ways, as below: A) % bus_i type ... mpc.bus = [ 1 3 ... 2 1 ... 3 1 ... 4 1 ... 5 1 ... 6 1 ... 7 1 ... 8 1 ... 9 1 ... 10 1 ... 11 1 ... 12 1 ... 13 1 ... 14 1 ...]; B) % bus_i type ... mpc.bus = [ 1 3 ... 2 3 ... 3 3 ... 4 1 ... 5 1 ... 6 1 ... 7 1 ... 8 1 ... 9 1 ... 10 1 ... 11 1 ... 12 1 ... 13 1 ... 14 1 ... 15 1 ... 16 1 ...]; When carrying out the load flow for the two cases (A and B), success was obtained for the two cases by Newton's method. However, for the PSUM, ISUM, and YSUM methods, none of them were successful. Can anyone tell me if there is the possibility of running the load flow for distribution systems Radials that use the representation of a substation for each feeder?
Non-Convergence of Load Flow in Reconfiguration / Restoration Situations (via Optimization)
for Reconfiguration/Restoration process, ie: Occurrence of significant concentration of buses/Loads in a given healthy region (region that will receive some or all of the disconnected Loads) Of the feeder (as shown below) via the relocation of disconnected loads (optimization process) due to the insulation of some faulty upstream faults Of the off region. Exemplifying Illustration: I took the 33bw case as an example in three different load flow execution scenarios to exemplify my issue. SITUATION A: The case 33wb is illustrated below for a specific type of topology. For this configuration, there was convergence for the 4 methods (Newton, PQSUM, ISUM and YSUM) evaluated. [cid:e5bc401c-9dcf-4652-95d6-0a34c1612e2a] Situation B: Similarly, the case 33wb is illustrated below for another specific type of topology. For this new configuration, similar to the previous one, there was convergence for the 4 methods (Newton, PQSUM, ISUM and YSUM) evaluated. [cid:e5853435-5c77-4ca7-a0c3-ca16880e3aae] Situation C: For this new configuration, the 33wb case, shown below, presents a particular type of topology in which it has concentrated much load on the central feeder. The consequence of this was the non-convergence of all 4 methods (Newton, PQSUM, ISUM and YSUM) evaluated. [cid:3fab6827-4dad-4e5f-a598-08fc4967a9c5] Note: This analysis was also performed for other feeders (case 84, case 85, case 135 and case70). It seems to me that in the act of network switching (each switching sequence is a possible solution), by concentrating Loads in a given region of the network, the possibility of non-convergence is high, regardless of the method used. I would like to know how to proceed with this problem. For the evolutionary algorithm I use needs to evaluate this configuration, even Knowing that such a solution is not feasible and possibly will be ruled out by the restriction criteria of the optimization that I have adopted. What to do? Increase the number of iterations? How to make convergence of power flow occur even for those absurd configurations?
Re: Power Flow for Radial Test Systems with several Feeders
Dear Mr. Todorovski, thanks for the answer! De: bounce-121631454-77188...@list.cornell.edu em nome de Mirko Todorovski Enviado: quinta-feira, 29 de junho de 2017 21:10 Para: MATPOWER discussion forum; MATPOWER-L@cornell.edu Assunto: Re: Power Flow for Radial Test Systems with several Feeders Case B can't be solved with PQSUM, ISUM or YSUM since there are three slack buses. There must be only one slack (supply) bus for the distribution network. Case A can be solved but you should put branches 1-2 and 1-3. Their parameters may all be zero (r, x and b). However, bear in mind the zero-impedance branches are problematic for the Netwon method. Finally, do you include tie branches 5-11, 10-14 and 7-16? If yes, the network consists loops and can't be solved with the current version of PQSUM, ISUM or YSUM. Best regards, Mirko On 06/29/2017 03:47 PM, Andrey Vieira wrote: Hi All. With regard to the use of load flow for radial networks, I would like to know if there is for distribution systems with several separately represented radial feeders. That is, each one With their respective sources (substations). For example, note the case 16 buses below [cid:part1.1D613F18.D13FF2F7@feit.ukim.edu.mk] This case can be represented in MATPOWER in two different ways, as below: A) % bus_i type ... mpc.bus = [ 1 3 ... 2 1 ... 3 1 ... 4 1 ... 5 1 ... 6 1 ... 7 1 ... 8 1 ... 9 1 ... 10 1 ... 11 1 ... 12 1 ... 13 1 ... 14 1 ...]; B) % bus_i type ... mpc.bus = [ 1 3 ... 2 3 ... 3 3 ... 4 1 ... 5 1 ... 6 1 ... 7 1 ... 8 1 ... 9 1 ... 10 1 ... 11 1 ... 12 1 ... 13 1 ... 14 1 ... 15 1 ... 16 1 ...]; When carrying out the load flow for the two cases (A and B), success was obtained for the two cases by Newton's method. However, for the PSUM, ISUM, and YSUM methods, none of them were successful. Can anyone tell me if there is the possibility of running the load flow for distribution systems Radials that use the representation of a substation for each feeder?
Re: Non-Convergence of Load Flow in Reconfiguration / Restoration Situations (via Optimization)
Mr. Ray, thanks for the answer! But in addition to the runpf () function, in what other functions should I make the change in the number of iterations? De: bounce-121637368-77188...@list.cornell.edu em nome de Ray Zimmerman Enviado: segunda-feira, 3 de julho de 2017 19:56 Para: MATPOWER discussion forum Assunto: Re: Non-Convergence of Load Flow in Reconfiguration / Restoration Situations (via Optimization) If you haven’t tried it, certainly try increasing the number of iterations for the radial methods. Ray On Jul 3, 2017, at 3:15 PM, Andrey Vieira mailto:andre...@hotmail.com>> wrote: for Reconfiguration/Restoration process, ie: Occurrence of significant concentration of buses/Loads in a given healthy region (region that will receive some or all of the disconnected Loads) Of the feeder (as shown below) via the relocation of disconnected loads (optimization process) due to the insulation of some faulty upstream faults Of the off region. Exemplifying Illustration: I took the 33bw case as an example in three different load flow execution scenarios to exemplify my issue. SITUATION A: The case 33wb is illustrated below for a specific type of topology. For this configuration, there was convergence for the 4 methods (Newton, PQSUM, ISUM and YSUM) evaluated. Situation B: Similarly, the case 33wb is illustrated below for another specific type of topology. For this new configuration, similar to the previous one, there was convergence for the 4 methods (Newton, PQSUM, ISUM and YSUM) evaluated. Situation C: For this new configuration, the 33wb case, shown below, presents a particular type of topology in which it has concentrated much load on the central feeder. The consequence of this was the non-convergence of all 4 methods (Newton, PQSUM, ISUM and YSUM) evaluated. Note: This analysis was also performed for other feeders (case 84, case 85, case 135 and case70). It seems to me that in the act of network switching (each switching sequence is a possible solution), by concentrating Loads in a given region of the network, the possibility of non-convergence is high, regardless of the method used. I would like to know how to proceed with this problem. For the evolutionary algorithm I use needs to evaluate this configuration, even Knowing that such a solution is not feasible and possibly will be ruled out by the restriction criteria of the optimization that I have adopted. What to do? Increase the number of iterations? How to make convergence of power flow occur even for those absurd configurations?
Re: Non-Convergence of Load Flow in Reconfiguration / Restoration Situations (via Optimization)
Now I get it. I'll do change. Thanks!! De: bounce-121639335-77188...@list.cornell.edu em nome de Ray Zimmerman Enviado: quarta-feira, 5 de julho de 2017 12:45 Para: MATPOWER discussion forum Assunto: Re: Non-Convergence of Load Flow in Reconfiguration / Restoration Situations (via Optimization) No need to change code. Simply set the 'pf.radial.max_it' option to a value larger than the default 20. Ray On Jul 3, 2017, at 4:03 PM, Andrey Vieira mailto:andre...@hotmail.com>> wrote: Mr. Ray, thanks for the answer! But in addition to the runpf () function, in what other functions should I make the change in the number of iterations? De: bounce-121637368-77188...@list.cornell.edu<mailto:bounce-121637368-77188...@list.cornell.edu> mailto:bounce-121637368-77188...@list.cornell.edu>> em nome de Ray Zimmerman mailto:r...@cornell.edu>> Enviado: segunda-feira, 3 de julho de 2017 19:56 Para: MATPOWER discussion forum Assunto: Re: Non-Convergence of Load Flow in Reconfiguration / Restoration Situations (via Optimization) If you haven’t tried it, certainly try increasing the number of iterations for the radial methods. Ray On Jul 3, 2017, at 3:15 PM, Andrey Vieira mailto:andre...@hotmail.com>> wrote: for Reconfiguration/Restoration process, ie: Occurrence of significant concentration of buses/Loads in a given healthy region (region that will receive some or all of the disconnected Loads) Of the feeder (as shown below) via the relocation of disconnected loads (optimization process) due to the insulation of some faulty upstream faults Of the off region. Exemplifying Illustration: I took the 33bw case as an example in three different load flow execution scenarios to exemplify my issue. SITUATION A: The case 33wb is illustrated below for a specific type of topology. For this configuration, there was convergence for the 4 methods (Newton, PQSUM, ISUM and YSUM) evaluated. Situation B: Similarly, the case 33wb is illustrated below for another specific type of topology. For this new configuration, similar to the previous one, there was convergence for the 4 methods (Newton, PQSUM, ISUM and YSUM) evaluated. Situation C: For this new configuration, the 33wb case, shown below, presents a particular type of topology in which it has concentrated much load on the central feeder. The consequence of this was the non-convergence of all 4 methods (Newton, PQSUM, ISUM and YSUM) evaluated. Note: This analysis was also performed for other feeders (case 84, case 85, case 135 and case70). It seems to me that in the act of network switching (each switching sequence is a possible solution), by concentrating Loads in a given region of the network, the possibility of non-convergence is high, regardless of the method used. I would like to know how to proceed with this problem. For the evolutionary algorithm I use needs to evaluate this configuration, even Knowing that such a solution is not feasible and possibly will be ruled out by the restriction criteria of the optimization that I have adopted. What to do? Increase the number of iterations? How to make convergence of power flow occur even for those absurd configurations?
Re: Non-Convergence of Load Flow in Reconfiguration / Restoration Situations (via Optimization)
Dear Mr. Todorovsk, Thanks for the answer. Would such a change only be in the calc_v_y_sum function (line 37)? Or in another function? in the function calc_v_y_sum: . . . 33 - % ZIP load model 34 -pw = mpopt.exp.sys_wide_zip_loads.pw; 35 -qw = mpopt.exp.sys_wide_zip_loads.qw; 36 -if isempty(pw) 37 -pw = [1 0 0]; % CHANGE HERE to [0 0 1] 38 -end 39 -if isempty(qw) 40 -qw = pw; 41 -end 42- Sdz = real(Sd) * pw(3) + 1j * imag(Sd) * qw(3); % constant impedance 43- Sdi = real(Sd) * pw(2) + 1j * imag(Sd) * qw(2); % constant current 44- Sdp = real(Sd) * pw(1) + 1j * imag(Sd) * qw(1); % constant power . . . De: bounce-121637485-77188...@list.cornell.edu em nome de Mirko Todorovski Enviado: segunda-feira, 3 de julho de 2017 21:24 Para: MATPOWER discussion forum Assunto: Re: Non-Convergence of Load Flow in Reconfiguration / Restoration Situations (via Optimization) I would suggest that you try to use the option for setting exp.sys_wide_zip_loads.pw. If you model all loads as constant admittances by using pw = [0 0 1] you will certainly get a solution with YSUM since in this case the network is linear and the solution will be obtained in single iteration. If you get low voltages in the network (say 0.8 pu or lower) it is likely that the operating conditions are not acceptable and such configuration should be discarted. I suspect that this is the problem, you can not mantain constant power requirement if voltages go down and therefore all method divergee. Whether you can model your loads as constant impedances or constant power is out of the scope of MATPOWER. Depending on the character of consumers in a distribution network probably it is more realistic to expect loads close to constant admittance that to constant power. If you have load static characteristics, i.e. dependence of P and Q on the voltage you may choose appropriate values for the vector pw (not just simply setting [1 0 0] or [0 0 1]). Best regards, Mirko On Mon, 2017-07-03 at 15:56 -0400, Ray Zimmerman wrote: > If you haven’t tried it, certainly try increasing the number of > iterations for the radial methods. > > >Ray > > > On Jul 3, 2017, at 3:15 PM, Andrey Vieira > > wrote: > > > > for Reconfiguration/Restoration process, ie: > > > > Occurrence of significant concentration of buses/Loads in a given healthy > > region (region that will receive some or all of the disconnected Loads) > > Of the feeder (as shown below) via the relocation of disconnected loads > > (optimization process) due to the insulation of some faulty upstream faults > > Of the off region. > > > > Exemplifying Illustration: > > > > I took the 33bw case as an example in three different load flow execution > > scenarios to exemplify my issue. > > SITUATION A: > > The case 33wb is illustrated below for a specific type of topology. > > For this configuration, there was convergence for the > > 4 methods (Newton, PQSUM, ISUM and YSUM) evaluated. > > > > > > > > > > > > > > > > > > > > > > Situation B: > > Similarly, the case 33wb is illustrated below for another specific type > > of topology. For this new configuration, similar to the previous one, > > there was convergence for the 4 methods (Newton, PQSUM, ISUM > > and YSUM) evaluated. > > > > > > > > > > > > > > > > > > > > Situation C: > > For this new configuration, the 33wb case, shown below, presents a > > particular type of topology in which it has concentrated much load > > on the central feeder. The consequence of this was the non-convergence > > of all 4 methods (Newton, PQSUM, ISUM and YSUM) evaluated. > > > > > > Note: This analysis was also performed for other feeders (case 84, > > case 85, case 135 and case70). It seems to me that in the act of network > > switching (each switching sequence is a possible solution), by > > concentrating Loads in a given region of the network, the possibility of > > non-convergence is high, regardless of the method used. I would like to > > know how to proceed with this problem. For the evolutionary algorithm > > I use needs to evaluate this configuration, even Knowing that such a > > solution is not feasible and possibly will be ruled out by the restriction > > criteria of the optimization that I have adopted. What to do? Increase the > > number of iterations? How to make convergence of power flow occur even for > > those absurd configurations? > >
Re: Non-Convergence of Load Flow in Reconfiguration / Restoration Situations (via Optimization)
Oh, I got it.
Mr. Todorovski, thank you so much.
De: bounce-121640945-77188...@list.cornell.edu
em nome de Mirko Todorovski
Enviado: quarta-feira, 5 de julho de 2017 22:04
Para: MATPOWER discussion forum
Assunto: Re: Non-Convergence of Load Flow in Reconfiguration / Restoration
Situations (via Optimization)
You don't have to change the code, just use mpoption as in the following
example
>> opt = mpoption('pf.alg','YSUM','exp.sys_wide_zip_loads.pw',[0 0 1]);
>> runpf('case18',opt)
Best regards,
Mirko
On Wed, 2017-07-05 at 17:29 +, Andrey Vieira wrote:
> Dear Mr. Todorovsk,
>
> Thanks for the answer.
> Would such a change only be in the calc_v_y_sum function (line 37)?
> Or in another function?
>
>
>
>
>
>
> in the function calc_v_y_sum:
>
> .
>
> .
>
> .
>
> 33 - % ZIP load model
> 34 - pw = mpopt.exp.sys_wide_zip_loads.pw;
> 35 - qw = mpopt.exp.sys_wide_zip_loads.qw;
> 36 - if isempty(pw)
> 37 -pw = [1 0 0]; % CHANGE HERE to [0 0 1]
> 38 - end
> 39 - if isempty(qw)
> 40 -qw = pw;
> 41 - end
> 42- Sdz = real(Sd) * pw(3) + 1j * imag(Sd) * qw(3); %
> constantimpedance
> 43- Sdi = real(Sd) * pw(2) + 1j * imag(Sd) * qw(2); % constantcurrent
> 44- Sdp = real(Sd) * pw(1) + 1j * imag(Sd) * qw(1); % constantpower
> .
>
>
> .
> .
>
>
>
>
> __
> De: bounce-121637485-77188...@list.cornell.edu
> em nome de Mirko
> Todorovski
> Enviado: segunda-feira, 3 de julho de 2017 21:24
> Para: MATPOWER discussion forum
> Assunto: Re: Non-Convergence of Load Flow in Reconfiguration /
> Restoration Situations (via Optimization)
>
> I would suggest that you try to use the option for setting
> exp.sys_wide_zip_loads.pw. If you model all loads as constant
> admittances by using pw = [0 0 1] you will certainly get a solution
> with
> YSUM since in this case the network is linear and the solution will be
> obtained in single iteration. If you get low voltages in the network
> (say 0.8 pu or lower) it is likely that the operating conditions are
> not
> acceptable and such configuration should be discarted. I suspect that
> this is the problem, you can not mantain constant power requirement if
> voltages go down and therefore all method divergee.
>
> Whether you can model your loads as constant impedances or constant
> power is out of the scope of MATPOWER. Depending on the character of
> consumers in a distribution network probably it is more realistic to
> expect loads close to constant admittance that to constant power. If
> you
> have load static characteristics, i.e. dependence of P and Q on the
> voltage you may choose appropriate values for the vector pw (not just
> simply setting [1 0 0] or [0 0 1]).
>
> Best regards,
> Mirko
>
> On Mon, 2017-07-03 at 15:56 -0400, Ray Zimmerman wrote:
> > If you haven’t tried it, certainly try increasing the number of
> > iterations for the radial methods.
> >
> >
> >Ray
> >
> > > On Jul 3, 2017, at 3:15 PM, Andrey Vieira
> > > wrote:
> > >
> > > for Reconfiguration/Restoration process, ie:
> > >
> > > Occurrence of significant concentration of buses/Loads in a given
> healthy
> > > region (region that will receive some or all of the disconnected
> Loads)
> > > Of the feeder (as shown below) via the relocation of disconnected
> loads
> > > (optimization process) due to the insulation of some faulty
> upstream faults
> > > Of the off region.
> > >
> > > Exemplifying Illustration:
> > >
> > > I took the 33bw case as an example in three different load flow
> execution
> > > scenarios to exemplify my issue.
> > > SITUATION A:
> > > The case 33wb is illustrated below for a specific type of
> topology.
> > > For this configuration, there was convergence for the
> > > 4 methods (Newton, PQSUM, ISUM and YSUM) evaluated.
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > > Situation B:
> > > Similarly, the case 33wb is illustrated below for another specific
> type
> > > of topology. For this new configuration, similar to the previous
> one,
> > > there was convergence for the 4 methods (Newton, PQSUM, ISUM
> > > and YSUM) evaluated.
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > > Situation C:
> >
How to Obtain Electric Current in branches with Zero Loss Indication
I need to get the electric current in each of the parts of certain cases ieee (for example 84 buses) after the load flow simulation. One of the ways is by means of the electrical losses in each of the branches. It turns out that there are cases (like the 84 buses) in which the indication of the losses in some branches is null. To see 84 buses example below (branches 1 - 2 and 2 - 3). How to obtain the current of the branches where the indication of losses is zero? | Branch Data | Brnch From ToFrom Bus Injection To Bus Injection Loss (I^2 * Z) # BusBusP (MW) Q (MVAr) P (MW) Q (MVAr) P (MW) Q (MVAr) - - - 1 1 2 0.00 0.00 0.00 0.00 0.000 0.00 2 2 3 -0.00 0.00 0.00 -0.00 0.000 0.00 3 3 4 -0.08 -0.04 0.08 0.04 0.000 0.00 4 4 5 -0.33 -0.20 0.33 0.20 0.000 0.00 5 5 6 -0.61 -0.41 0.61 0.41 0.001 0.00 6 6 7 -0.79 -0.49 0.79 0.49 0.000 0.00 7 7 8 -1.70 -1.15 1.70 1.16 0.002 0.01 8 8 9 0.25 0.17 -0.25 -0.16 0.000 0.00 9 8 10 0.25 0.19 -0.25 -0.19 0.000 0.00 10 8 11 0.25 0.21 -0.25 -0.21 0.000 0.00 11 1 12 2.62 1.89 -2.61 -1.88 0.006 0.01 12 12 13 2.61 1.88 -2.59 -1.82 0.027 0.06 .. .. ... ... .. .. .. .... ..
How Consider the current limitation in MATPOWER?
Dear All, I have a question about what refers to the power limitations indicated in columns 6, 7 and 8 of the matrix mpc.branch of the IEEE cases of the MATPOWER runpf function. From the manual it is known that: namecol description ... . . . ... . . . ... . . . ... RATE_A 6 MVA rating A (long time rating) , set to 0 for unlimited RATE_B 7 MVA rating B (short time rating), set to 0 for unlimited RATE_C 8 MVA rating C (emergency time rating), set to 0 for unlimited . .... . .... . .... First, there is how to insert the current value limitation, not the power limit (MVA) in the segments of the lines aiming at studies of reconfiguration and / or restoration? Or we must always calculate the corresponding power Does each branch? Another thing. I am working with single maximum current value for each branch. I do not have the power information for each of the required situations (long, short and emergency) by MATPOWER. Do I only have one maximum current value for each part of the blower? How should I proceed? Should I consider only the maximum current I have by the equivalent (calculated) maximum power to MVA ratinc C in mpc.branch?
Re: How Consider the current limitation in MATPOWER?
Mrs Ray and Ehsan Thank you so much!!! De: bounce-122083389-77188...@list.cornell.edu em nome de Ray Zimmerman Enviado: terça-feira, 28 de novembro de 2017 14:07 Para: MATPOWER discussion forum Assunto: Re: How Consider the current limitation in MATPOWER? Yes, RATE_A is the only rating that is currently used by the OPF, so no need to worry about providing RATE_B and RATE_C. And you can set opf.flow_lim to 'I' for current, in which case the value of RATE_A should be the MVA value that corresponds to your desired current limit assuming 1 p.u. voltages. Ray On Nov 24, 2017, at 1:27 PM, Ehsan Hejri mailto:ehsan.hejri@gmail.com>> wrote: Dear Andrey Viera, I think it is only in OPF possible to set the Rate_A. Table 6-3 (opf.flow_lim= 'S' or 'P'or 'I') Best Wishes, Ehsan On Fri, Nov 24, 2017 at 6:33 PM, Andrey Vieira mailto:andre...@hotmail.com>> wrote: Dear All, I have a question about what refers to the power limitations indicated in columns 6, 7 and 8 of the matrix mpc.branch of the IEEE cases of the MATPOWER runpf function. From the manual it is known that: namecol description ... . . . ... . . . ... . . . ... RATE_A 6 MVA rating A (long time rating) , set to 0 for unlimited RATE_B 7 MVA rating B (short time rating), set to 0 for unlimited RATE_C 8 MVA rating C (emergency time rating), set to 0 for unlimited . .... . .... . .... First, there is how to insert the current value limitation, not the power limit (MVA) in the segments of the lines aiming at studies of reconfiguration and / or restoration? Or we must always calculate the corresponding power Does each branch? Another thing. I am working with single maximum current value for each branch. I do not have the power information for each of the required situations (long, short and emergency) by MATPOWER. Do I only have one maximum current value for each part of the blower? How should I proceed? Should I consider only the maximum current I have by the equivalent (calculated) maximum power to MVA ratinc C in mpc.branch?
Zero Sequence Impedance to Networks Radial Systems - Test Systems IEEE
The impedance data of the IEEE Test System (33, 69, 70, 84, 119 and 135 buses) correspond to the positive sequence impedances, which also correspond to the negative sequence impedances (Z1 = Z2). Where can I find the zero sequence impedances for these same networks?
