Dear Jin,
Yes, you are right.

However according to my experience, you have to be careful regarding the 
calculation of Jacobian of voltage sensitivities which might be required to 
translate Lagrange multipliers to LMP components.
Matpower can give these sensitivities (Jacobian) from the function makeJac().
So if you calculate Jacobian like makeJac(mpc), then it will give you 
sensitivity at the base case.
Hence to get the updated Jacobian (representing the operating conditions), you 
need to implement something like makeJac(results_pf), where results_pf = 
runpf(mpc).
Another issue, which I believe was corrected by Ray, was that if you have 
generators in the grid they were taken by-default as PV while making the 
Jacobian. So you might need to get the updated version of MATPOWER.
Maybe Ray could shed some more light on making sure the steps for correctly 
translating Lagrange multipliers to LMP components.

Hope it helps.
Best,
Sarmad
From: bounce-122459850-74036...@list.cornell.edu 
[mailto:bounce-122459850-74036...@list.cornell.edu] On Behalf Of Ma Jin
Sent: Wednesday, 11 April, 2018 5:24 PM
To: MATPOWER discussion forum
Subject: Re: Question about shadow price of line flow constraints in AC OPF

Dear Sarmad,

Thanks! Matpower provides the values of all Kuhn-tucker multipliers and 
Lagrange multipliers. So it is really a powerful tool which makes decomposition 
of the price possible if one wants to.

Kind regards,
Jin

2018-04-11 17:12 GMT+10:00 Sarmad Hanif 
<sarmad.ha...@tum-create.edu.sg<mailto:sarmad.ha...@tum-create.edu.sg>>:
Hi Jin,
I couldn’t understand the issue you reported. But according to my knowledge, 
MATPOWER gives you the final price at the node, it doesn’t calculate individual 
congestion, loss, energy components.
Moreover, for ACOPF, MATPOWER gives you and active ($/MW) and reactive power 
($/MVar) marginal prices at respective nodes.
Hope it helps.

From: 
bounce-122459082-74036...@list.cornell.edu<mailto:bounce-122459082-74036...@list.cornell.edu>
 
[mailto:bounce-122459082-74036...@list.cornell.edu<mailto:bounce-122459082-74036...@list.cornell.edu>]
 On Behalf Of Ma Jin
Sent: Wednesday, 11 April, 2018 8:04 AM
To: MATPOWER-L@cornell.edu<mailto:MATPOWER-L@cornell.edu>
Subject: Question about shadow price of line flow constraints in AC OPF

Dear all,

I feel confused about the unit of the shadow price of the line flow constraints 
in AC based OPF. Since the square of the apparent power is used when building 
the line flow constraints, the shadow price should be with a unit of 
$/(MVA*MVA). When it is converted to the shadow price $/MVA, MatPower times the 
RateA of that line, but for me, it more makes sense if it is multiplied with 
the apparent power flowing through the line. What is the reason behind 
multiplying that RateA. Thanks!

Kind regards,
Jin


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