can we have a function to fix the line/circuit breaker thing the raw file 0 -> 99999 ?

[jd-lara]

No description provided.

[leorese]

There are two different issues described here, as follows:

1. Treatment of 0 MVA branch rates
2. Treatment of zero impedance lines
   Suggested treatment for each of those issues is given as follows.

0 MVA branch rates
In PSS/E, if RATEX = 0.0, PSS/E will bypass checks for this branch (this branch will not be included in any examination of circuit loading).
In case of Sienna, it is suggested that the branch rate be parsed with the exact same value as in PSS/E (0.0). During the network constraints formulation, if branch rate is equal to 0.0, no branch limit constraint should be assigned to that branch.
Another alternative would be to set the branch rate to Inf. This is equivalent of not enforcing branch limits to the specific branch. However, this option is not recommended.

Zero impedance lines
In PSS/E, zero impedance lines are defined as having the following characteristics:

• Its resistance must be zero.
• Its magnitude of reactance must be less than or equal to the zero impedance line threshold tolerance, THRSHZ.
• It must be a non-transformer branch.
  The zero impedance line threshold tolerance, THRSHZ, may be changed using the category of solution parameter data via activity CHNG or the [Solution Parameters] dialog. Setting THRSHZ to zero disables zero impedance line modeling, and all branches are represented with their specified impedances.
  During network solutions, buses connected by such lines are treated as the same bus, thus having identical bus voltages. At the completion of each solution, the loadings on zero impedance lines are determined. When obtaining power flow solutions, zero impedance line flows, as calculated at the end of the solution, are preserved with the working case and are available to the power flow solution reporting activities.
  There are two options to model zero impedance branches in Sienna, as follows:

1. Implement a topological pre-processor when formulating the network matrices and replicate the treatment made by PSS/E (merge nodes into a single one and post-process flows from the DC power flow solution)
2. Explicitly model the zero impedance branches using the formulation presented in: https://ieeexplore.ieee.org/document/117003 (a more comprehensive presentation of this formulation, for both AC and DC PF formulations, is given here: https://simoes.sites.ufsc.br/assp/z_zero.pdf)
   Attention must be made to the check of circuit breaker status (open/closed) when building the network matrices.