Transmat details

[Alex David]

Dear Ray/others,

 

I have a question regarding "transmat" value used in "most ex7 suc.m". Mainly, I'm confused with the values given in "ex_transmat(nt)":

 

T = [ 0.158655253931457; 0.682689492137086; 0.158655253931457 ]

 

Any pointers can be very helpful. Also, pardon for the naive question (if it is).

 

Thanks,

Alex

Re: Introducing contingency in the network

[Abhyankar, Shrirang G.]

Don’t think there is an API, like total_load, that calculates total generation. 
You can do this easily by summing the active powers (PG column) in the mpc.gen 
array.

If you have any question on what API functions are available in MATPOWER then 
please refer to
http://www.pserc.cornell.edu//matpower/docs/ref/

Thanks,
Shri
Ph: (630) 252 0219
www.mcs.anl.gov/~abhyshr



From:  on behalf of Zain Anwer 
Memon 
Reply-To: MATPOWER discussion forum 
Date: Wednesday, January 17, 2018 at 10:12 AM
To: MATPOWER discussion forum 
Subject: Re: Introducing contingency in the network

ok and how can I find total generation like we find total load through 
total_load?

On Wed, Jan 17, 2018 at 5:07 PM, Abhyankar, Shrirang G. 
mailto:abhy...@anl.gov>> wrote:
MATPOWER’s power flow does not enforce generator active power limits. To do so, 
run a dc optimal power flow (rundcopf).

Thanks,
Shri
Ph: (630) 252 0219
www.mcs.anl.gov/~abhyshr



From: 
mailto:bounce-122200108-73493...@list.cornell.edu>>
 on behalf of Zain Anwer Memon 
mailto:zainanwerme...@gmail.com>>
Reply-To: MATPOWER discussion forum 
mailto:matpowe...@list.cornell.edu>>
Date: Wednesday, January 17, 2018 at 4:35 AM
To: "matpowe...@list.cornell.edu" 
mailto:matpowe...@list.cornell.edu>>
Subject: Introducing contingency in the network

Hello everyone,

I am analyzing a simple case, that has 3 generators and liming the max power of 
all the generators to some limit.
If I turn off one generator, and run dc power flow, then one of the generator 
real power is increased by its own more than its MAX Power to meet the load 
requirement.
how generators real power becomes more than its max active power power limit?
I just want to have a difference in generation and demand so that I can 
implement a deterministic algorithm.

--
Zain Anwer Memon





--
Zain Anwer Memon

Re: Introducing contingency in the network

[Zain Anwer Memon]

ok and how can I find total generation like we find total load through
total_load?

On Wed, Jan 17, 2018 at 5:07 PM, Abhyankar, Shrirang G. 
wrote:

> MATPOWER’s power flow does not enforce generator active power limits. To
> do so, run a dc optimal power flow (rundcopf).
>
>
>
> Thanks,
>
> Shri
>
> Ph: (630) 252 0219
>
> www.mcs.anl.gov/~abhyshr
>
>
>
>
>
>
>
> *From: * on behalf of Zain
> Anwer Memon 
> *Reply-To: *MATPOWER discussion forum 
> *Date: *Wednesday, January 17, 2018 at 4:35 AM
> *To: *"matpowe...@list.cornell.edu" 
> *Subject: *Introducing contingency in the network
>
>
>
> Hello everyone,
>
>
>
> I am analyzing a simple case, that has 3 generators and liming the max
> power of all the generators to some limit.
>
> If I turn off one generator, and run dc power flow, then one of the
> generator real power is increased by its own more than its MAX Power to
> meet the load requirement.
>
> how generators real power becomes more than its max active power power
> limit?
>
> I just want to have a difference in generation and demand so that I can
> implement a deterministic algorithm.
>
>
>
> --
>
> Zain Anwer Memon
>
>
>
>
>



-- 
Zain Anwer Memon

Re: load shedding by keeping load's power factor

[Abhyankar, Shrirang G.]

I don’t know of any straightforward way to do this in MATPOWER. You’ll need to 
add user-defined linear constraint to force the relationship between real and 
reactive power to keep the power factor constant.

Turns out this question has already been addressed on the MATPOWER forum.
https://www.mail-archive.com/matpower-l@cornell.edu/msg01084.html

Thanks,
Shri
Ph: (630) 252 0219
www.mcs.anl.gov/~abhyshr



From:  on behalf of سید محمدرضا 
ساداتیان 
Reply-To: MATPOWER discussion forum 
Date: Tuesday, January 16, 2018 at 12:01 PM
To: "matpowe...@list.cornell.edu" 
Subject: load shedding by keeping load's power factor

Hi, everyone.

by use dispatchable load, we can have load shedding in OPF.
How can have load shedding by keeping power factor of loads?

Thank you so much for consideration and help.

Re: Introducing contingency in the network

[Abhyankar, Shrirang G.]

MATPOWER’s power flow does not enforce generator active power limits. To do so, 
run a dc optimal power flow (rundcopf).

Thanks,
Shri
Ph: (630) 252 0219
www.mcs.anl.gov/~abhyshr



From:  on behalf of Zain Anwer 
Memon 
Reply-To: MATPOWER discussion forum 
Date: Wednesday, January 17, 2018 at 4:35 AM
To: "matpowe...@list.cornell.edu" 
Subject: Introducing contingency in the network

Hello everyone,

I am analyzing a simple case, that has 3 generators and liming the max power of 
all the generators to some limit.
If I turn off one generator, and run dc power flow, then one of the generator 
real power is increased by its own more than its MAX Power to meet the load 
requirement.
how generators real power becomes more than its max active power power limit?
I just want to have a difference in generation and demand so that I can 
implement a deterministic algorithm.

--
Zain Anwer Memon

Re: The question about extend OPF and the optimization tool

[Abhyankar, Shrirang G.]

Not sure if this is what you want, but here’s one way.

https://www.mail-archive.com/matpower-l@cornell.edu/msg00613.html

Thanks,
Shri
Ph: (630) 252 0219
www.mcs.anl.gov/~abhyshr
From:  on behalf of 
"neuqxhlin...@163.com" 
Reply-To: MATPOWER discussion forum 
Date: Wednesday, January 17, 2018 at 4:46 AM
To: "matpowe...@list.cornell.edu" 
Subject: The question about extend OPF and the optimization tool

Hi,
I see. Can we add the power loss into objective function in runopf() ?

-
Best regards,
Wei Lin 林巍
Zhejiang University,
Zheda Road 38#, Hangzhou, P.R.China, 310027
+86-13675865210

发件人: Ray Zimmerman [mailto:r...@cornell.edu]
发送时间: 2018年1月11日 23:56
收件人: neuqxhlin...@163.com
主题: Re: The question about extend OPF and the optimization tool

(FYI, in the future, please address such questions to the MATPOWER-L mailing 
list, not 
to me directly)

Yes, it is possible to add user-defined costs to the OPF. Please see Sections 
6.3 and 6.4 and Chapter 7 in the MATPOWER User’s 
Manual. If 
you need general non-linear costs, you will need to use the latest development 
version of MATPOWER on GitHub  You can 
find the corresponding version of the manual 
here  
describing how to use the non-linear user-defined costs and constraints.

Regarding YALMIP, MATPOWER does not use it except when using SDP_PF, so you 
cannot use it to modify the problem normally solved by runopf().

   Ray


On Jan 10, 2018, at 9:54 PM, 
mailto:neuqxhlin...@163.com>> 
mailto:neuqxhlin...@163.com>> wrote:

Dear matpower:
Thanks for matpower solving lots of problem in my power simulation.
I have a question about the objective function in OPF. Can the system add some 
user-defined function expecting the generators cost, Like power loss , voltage 
deviation ?
And the matpower can be with some optimization tools like yalmip ? When I use 
yalmip , I define some variable but it can not be solve in matpower?
Code like:
  clc;clear;
x = sdpvar(14,1);
assign(x,ones(14,1));
mpc = loadcase('case14');
mpc.bus(:,4) = mpc.bus(:,4)  + value(x);
mpopt = mpoption('verbose',0,'out.all',0);
result = runpf(mpc,mpopt);
f = sum(abs(get_losses(result)));
F= [sum(x)<=50];
sdp_result = solvesdp(F,f);
   and the result show the yalmip is successfully sovled , but the result 
is not right.
Hope you can help me.

-
Best regards,
Wei Lin 林巍
Zhejiang University,
Zheda Road 38#, Hangzhou, P.R.China, 310027
+86-13675865210

The question about extend OPF and the optimization tool

[neuqxhlinwei]

Hi, 

I see. Can we add the power loss into objective function in runopf() ?

 

-

Best regards,

Wei Lin 林巍

Zhejiang University, 

Zheda Road 38#, Hangzhou, P.R.China, 310027

+86-13675865210

 

发件人: Ray Zimmerman [mailto:r...@cornell.edu] 
发送时间: 2018年1月11日 23:56
收件人: neuqxhlin...@163.com  
主题: Re: The question about extend OPF and the optimization tool

 

(FYI, in the future, please address such questions to the  
 
MATPOWER-L mailing list, not to me directly)

 

Yes, it is possible to add user-defined costs to the OPF. Please see Sections 
6.3 and 6.4 and Chapter 7 in the MATPOWER User 
 ’s Manual. 
If you need general non-linear costs, you will need to use the latest 
development version of MATPOWER on GitHub 
   You can find the corresponding 
version of the manual here 
   
describing how to use the non-linear user-defined costs and constraints.

 

Regarding YALMIP, MATPOWER does not use it except when using SDP_PF, so you 
cannot use it to modify the problem normally solved by runopf().

 

   Ray

 

 

On Jan 10, 2018, at 9:54 PM, mailto:neuqxhlin...@163.com> > mailto:neuqxhlin...@163.com> > wrote:

 

Dear matpower:

Thanks for matpower solving lots of problem in my power simulation.

I have a question about the objective function in OPF. Can the system add some 
user-defined function expecting the generators cost, Like power loss , voltage 
deviation ?

And the matpower can be with some optimization tools like yalmip ? When I use 
yalmip , I define some variable but it can not be solve in matpower?

Code like:

  clc;clear;

x = sdpvar(14,1);

assign(x,ones(14,1));

mpc = loadcase('case14');

mpc.bus(:,4) = mpc.bus(:,4)  + value(x);

mpopt = mpoption('verbose',0,'out.all',0);

result = runpf(mpc,mpopt);

f = sum(abs(get_losses(result)));

F= [sum(x)<=50];

sdp_result = solvesdp(F,f); 

   and the result show the yalmip is successfully sovled , but the result 
is not right.

Hope you can help me.

 

-

Best regards,

Wei Lin 林巍

Zhejiang University, 

Zheda Road 38#, Hangzhou, P.R.China, 310027

+86-13675865210

 

Introducing contingency in the network

[Zain Anwer Memon]

Hello everyone,

I am analyzing a simple case, that has 3 generators and liming the max
power of all the generators to some limit.
If I turn off one generator, and run dc power flow, then one of the
generator real power is increased by its own more than its MAX Power to
meet the load requirement.
how generators real power becomes more than its max active power power
limit?
I just want to have a difference in generation and demand so that I can
implement a deterministic algorithm.

-- 
Zain Anwer Memon