See Also
The Results Constraints page of the Time Step Simulation dialog is used to convey results that are specific to an optimal power flow type of study. This page is only available with the OPF and SCOPF add-ons of Simulator. When the OPF solution type is used to solve a time point, the status of the system during that particular time is optimized so that the total operating cost of the system is minimized, and the normal operation constraints are enforced. In addition, the SCOPF solution type enforces contingency constraints. The OPF and SCOPF solutions contain information about the elements that determine the LMPs, the binding constraints, the violating contingencies, and changes in the control settings.
The information related to contingencies on these pages is available only in the SCOPF Simulator add-on.
The pages of the Results: Constraints page are:
Results Summary
This page is similar to the Summary Page, except that it contains additional operating information such as:
Initial Cost
The cost of operating the system given the initial generator set points and a standard power flow solution. No controls are moved to minimize cost.
Unconstrained Cost
The total operating cost after the controls are moved to minimize cost, without enforcing any normal operation or contingency constraint. The result is an operating cost that corresponds to an Economic Dispatch solution.
Unconstrained LMP
The average marginal price of the system under unconstrained optimization.
Final Cost
The total operating cost after a constrained (OPF or SCOPF) solution has been obtained.
LMP
(Average, Standard Deviation, Minimum and Maximum): Metrics of the LMP values.
Binding Lines
Number of transmission lines and transformers that are binding after the OPF/SCOPF solution has been determined.
# CTGs Unsolvable
Number of unsolvable contingencies. These are severe contingencies that would cause the power flow solution to fail for that particular time point scenario. Unsolvability of the power flow case is related to maximum loadability conditions.
You can access the details of the binding elements by right-clicking and selecting Show Binding Constraint Dialog on the local menu.
Binding Lines
This is a matrix grid that shows information for transmission lines and transformers that become binding constraints during the OPF or SCOPF solutions. A similar page is available for binding interfaces.
When transmission lines or transformer thermal ratings become binding constraints for a time point, a column is automatically added, forming in this manner the matrix grid. You can access the details of the binding line or transformer by right-clicking and selecting Show Binding Constraint Dialog on the local menu. The grid also shows the following summary columns:
Processed
Gets set to YES if the time point was correctly processed.
CTGs with Viols
Number of contingencies that presented one or more violations (violating contingencies).
# CTGs Unsolveable
Number of unsolvable contingencies for the time point.
BC Line Viols
Number of transmission line and transformer violations that were identified in the base case.
# Line Viol
Number of transmission line and transformer thermal violations.
Binding Lines
Number of binding lines in the OPF/SCOPF solution.
Line Unenforceable
Number of lines with unenforceable limits.
Binding Interfaces
This is a matrix grid that shows information for interfaces that become binding constraints during the OPF or SCOPF solutions. A similar page for lines is available.
When interfaces become binding constraints for a time point, a column is automatically added to the matrix grid. You can access the details of the binding interface by right clicking and selecting Show Binding Constraint Dialog on the local menu. The grid also shows the following summary columns:
Processed
Gets set to YES if the time point was correctly processed.
CTGs with Viols
Number of contingencies that presented violations (violating contingencies)
# CTGs Unsolveable
Number of unsolvable contingencies for the time point.
BC Interface Viols
Number of interface violations that were identified in the base case.
# Interface Viol
Number of interface violations.
Binding Interface
Number of binding interfaces in the OPF/SCOPF solution.
Interface Unenforceable
Number of interfaces with unenforceable limits.
Binding Contingencies
This matrix grid shows information similar to that found on the Binding Lines and Binding Interfaces pages. Here though the data is organized by contingencies, which allows easy identification of the most severe contingencies. Each column of the matrix grid corresponds to a contingency. You can access the details of the binding element by right-clicking and selecting Show Binding Constraint Dialog on the local menu. The grid also shows the following summary columns:
Processed
Gets set to YES if the time point was correctly processed.
CTGs with Viols
Number of contingencies that presented violations (violating contingencies) .
# Line Viol
Number of transmission line and transformer thermal violations.
Binding Lines
Number of binding lines in the OPF/SCOPF solution.
Binding Interfaces
Number of binding interfaces in the OPF/SCOPF solution.
Binding Line Summary Matrix
This matrix grid shows the number of time points for which a line has been binding due to each contingency. In this case, the rows correspond to binding lines, and the columns to violating contingencies. The grid also shows the following summary columns:
From Number
Binding line from bus number
To Number
Binding line to bus number
Circuit
Binding line circuit ID
Total Hrs
Total number of time points for which the line was binding (in the overall simulation).
Total Hrs Unenforceable
Total number of time points for which the line constraint was unenforceable (in the overall simulation).
Binding Line Summary List
Shows information similar to the Binding Line Summary Matrix but in form of a list. The same line may appear several times under different contingencies. Besides the information on the Binding Line Summary Matrix, this grid shows the following fields:
Contingency Name
Contingency that causes the line constraint to be binding
Avg MC
Time Average MVA Marginal Cost
Max MC
Time Maximum MVA Marginal Cost
Min MC
Time Minimum MVA Marginal Cost