See Also
The control dialog allows the user to manually or automatically run a SCOPF simulation and visualize the execution of the simulation. The SCOPF solution process involves three steps: base case solution and initialization, contingency analysis, and SCOPF iterations.
Run Full Security Constrained OPF
Press this button to run the three steps of the SCOPF solution automatically. The SCOPF will solve the base case using the selected method, will use the currently stored list of contingencies during the contingency analysis step, and will take the CA results and sensitivities to iterate in order to obtain the optimal solution that minimizes cost and enforces contingency violations.
Options
Maximum Number of Outer Loop Iterations
Indicates the number of maximum outer loop iterations. The outer loop iterations determines how many times the contingency analysis will be re-run following a successful SCOPF dispatch. In this manner, Simulator will look for new violations that may occur due to the new generation dispatch.
Consider Binding Contingent Violations from Last SCOPF Solution
When checked, this option ensures that the contingent violations from the last SCOPF solution are included in the current SCOPF solution. This option is helpful in preventing the SCOPF from hunting between having a constraint binding in one solution, and resolving with it not binding in a later solution because it was previously remedied. This option should generally always be checked, unless the user is sure that the previous solution has no bearing on the current solution, such as having made major changes to the system since the previous solution.
Initialize SCOPF with Previously Binding Constraints
When checked, this option results in the SCOPF solution process starts with the exact same LP tableau from the last solution. This can make for fairly fast solutions (recognizing that the contingency analysis needs to be resolved) when the changes to the system are small. Simulator automatically uses this option when doing multiple outer loops of the SCOPF. This option allows the user to solve the outer loops (set the outer loop counter to 1) by repeatedly solving the SCOPF manually, potentially making modifications between solutions if desired.
Set Solution as Contingency Analysis Reference Case
Check this field to set the solution of the SCOPF as the contingency analysis reference. If the system has enough controls to remove all the contingency violations, a rerun of the contingency analysis using the SCOPF solution as the reference should report no branch violations.
Maximum Number of Contingency Violations Allow Per Element
Specify the maximum number of contingency violations that the SCOPF analysis should allow per element. After completing the power flow solutions for the base case and the contingencies, only this number of contingency violations per element are then passed to the linear programming algorithm. The assumption is that if you fix the 10 worst contingency violations for an element then the others will also be fixed.
Basecase Solution Method
Specifies whether the solution of the base case is performed using the power flow algorithm or the optimal power flow algorithm. The selection will affect the initial conditions of the system and consequently the contingency analysis results and the sensitivities used by the LP solver. Currently the SCOPF does not resolve the contingency analysis during the optimization since this is computationally expensive. See the SCOPF solution process for details.
Handling of Contingent Violations Due to Radial Load
It is often common when computing a security constrained OPF to have violations occur on branches due to radial load. In these instances, there is no way to adjust controls to continue to serve the load, without overloading the serving element. Therefore you can choose how contingent violations of this type should be handled by the SCOPF. You can choose to flag them but not include them in the SCOPF, ignore them completely, or include the violations in the SCOPF. Note that if you include the violations in the SCOPF, the SCOPF algorithm will not be able to remove the violation on the element via generation dispatch. However, it may be able to do so if the load in question has a load benefit curve defined and is available for load shed dispatch in the SCOPF routine.
DC SCOPF Options
The DC options given for the SCOPF revolve around the treatment of Line Outage Distribution Factors (LODF) during the DC SCOPF solution. You can choose to discard the LODFs when the SCOPF is finished or store them in memory (lost when Simulator is closed).
If the LODFs have been stored and you wish to clear them (they can require quite a bit of RAM depending on the number of contingencies and size of the case,) you can press the button labeled Clear Stored Contingency Analysis LODFs.
SCOPF Results Summary
Number of Outer Loop Iterations
The number of outer loop iterations required to solve the SCOPF.
Number of Contingent Violations
Number of violations from the contingency analysis portion of the solution, which are used to attempt to determine the security constrained dispatch.
SCOPF Start Time, SCOPF End Time
Physical time when the SCOPF solution process started and finished.
Total Solution Time (Seconds)
Length of time needed to determine the SCOPF solution.
Total LP Iterations
Total number of Linear Programming iterations necessary to determine the SCOPF solution.
Contingency Analysis Input
Number of Active Contingencies
The number of contingencies included in the SCOPF simulation. Specific contingencies may be excluded from the simulation in the contingency analysis dialog by changing the skip field of a contingency to YES. The contingency analysis dialog can be conveniently accessed from the SCOPF control dialog.
View Contingency Analysis Form
Clicking this button shows the contingency analysis dialog.
Contingency Analysis Results
This window allows the user to monitor the details of the contingency analysis step. During contingencies, the outage actions, the solution of each contingency, and the solution of the CA run are reported.