Simulator - Contingency Analysis

Simulator comes with an extremely robust contingency analysis tool that supports both single-element and multiple-element contingencies.  A contingency is an unexpected, but reasonably likely sudden change in the power system such as loss of a transmission line or generator.  Contingencies can be manually inserted, automatically generated, imported from an auxiliary file, or loaded with the case information.  

Following the introduction of the contingency analysis tool in Simulator version 5.0, PowerWorld has made continual improvements to the functionality and speed of calculation for the tool.  Some highlights of recent improvements are shown below.

V13 Contingency Analysis Improvements

• Added ability to view all contingency definitions in a single combined table case information display giving you possibility of using a single DATA section to define contingencies, or even using copy/paste to/from a spreadsheet to define your contingencies.
• Added ability to view all contingency violations in a single combined table case information display. Also gives ability to define using a DATA section or using copy/paste to/from a spreadsheet.
• Pan to object on oneline when selecting a limit violation in the contingency tool.

V12.0 Contingency Analysis Improvements

• Dead bus reporting
• dV/dQ change reporting
• Cloning and merging of contingencies
• Added post-contingency voltage limits where can be different than normal voltage limits

V11.0 Contingency Analysis Improvements

• New ways to visualize and export your contingency results.
• New contingency actions for opening/closing a 3-winding transformer.
• More contingency actions for Injection Groups, DC Lines, and Phase Shifters.
• Added contingency action for specifying the generator or switched shunt setpoint voltage.
• Ability to ramp an injection group up or down using "Merit Order" dispatch.
• Specify whether and how a generator’s MW output responds in the post-contingency solution.
• Modified the use of Model Criteria used in conjunction with contingency blocks.  Simulator will now perform an AND if a model criteria is specified at both contingency block level and the individual actions inside the block.
• Modified the Combined Tables in Contingency analysis so that it also included columns for Contingency Owner, Area, and Zone when they are shown in the Contingency Violation and Contingency Definition Tables.
• Added a new SUBDATA section "CTGElementAppend" to the object types Contingency, CTGElementBlock, GlobalContingencyActions, and PostPowerFlowActions. Actions inside these sections will be appended to a definition instead of replacing the actions presently specified.

V10.0 Contingency Analysis Improvements

• Introduced nomograms.  Nomograms can now be created representing a two-dimensional flow limit.  A nomogram is defined by specifying two interfaces as the two-dimensions, then specifying a curve representing the limitation on these interfaces.  These nomograms can then be monitored in contingency analysis, OPF, and ATC tools.
• Contingency analysis definitions, options, and results can now be stored in the PWB file.
• Contingency Comparison now includes violations from both the comparison and controlling case
• Improved the linear solution techniques for CTG so that they work properly when contingencies result in a change in the number of islands in the system
• Added support for handling "Load Throwover" records for buses. When a bus goes out-of-service as a result of a contingency the load at the bus is then moved to another bus to simulate distribution system switching.
• Many new contingency actions included: DC Line Open/Close and MW/Amp set-point modifications, Phase Shifter MW set-point modifications, Addition of a power flow solution inside the definition to change the method used for solving the power flow.
• More options for automated text file contingency reporting
• Added script commands for auto-inserting contingencies.
• Now record the total amount of load which is islanded during a contingency
• The post-contingency solution make-up power is now handled by utilizing Simulator's new Island-based Automatic Generation Control response.
• Post-contingency solution options are now stored in the reference state.

V9.0 Contingency Analysis Improvements

• Added "post-contingency" actions, which are set for execution based on the post-contingency state.  These can effectively model actions such as thermal relays.
• Added contingency blocks for defining a list of commonly occurring contingency actions.  These blocks can then be called from a contingency record directly allowing you to avoid needless repetition of a common list.
• Added Global Actions that are applied to all contingency records.
• Added injection group contingency actions applied to all loads or generators in the injection group.
• Added interface actions that can open or close all branches in an interface.
• Added new generator voltage control routines called Line Drop Compensation (LDC) and Reactive Current Compensation (RCC).  These help to model shorter-term voltage control such as in a post-contingency solution.
• Added ability to report contingency violations based on the change in limiting value from the base case. Using this, for example, you could report bus voltages which fall by more than 0.05 per unit or suppress reporting of line flows which increase by less than 2.0%.
• Added more make-up power options during contingency analysis to more accurately model generator response.
• Improved contingency analysis export capabilities making custom exporting possible.

V8.0 Contingency Analysis Improvements

• Conditional contingency actions allow you to create contingencies containing events that are conditional on the pre-contingent state of the power system.
• Numerous enhancements to aid in the interpretation of contingency analysis results.
• Added linear power flow solution technique to contingency analysis (DC Power Flow).