Auto Insert Contingencies

 

Simulator allows you to automatically generate a contingency list containing branch, generator, switched shunt, substation and/or bus outages. To accomplish this, click the Auto Insert button along the bottom of the Contingency Analysis Dialog or right-click on the list of contingencies table in the Contingencies Tab and select Insert Special > Auto Insert Contingencies…. This opens the Auto Insertion of Contingency Records dialog.

When automatically inserting contingencies, you must specify the type, options and naming conventions you want for the new contingencies. You must also specify whether to delete or retain existing contingencies.

 

Auto Insertion of Contingency Records Dialog

 

The Auto Insertion of Contingencies dialog has the following controls:

Automatically generate contingency involving a…

The options available in this box define what to add to each automatically inserted contingency element. You can choose single transmission line, transformer, transmission line or transformer, 3-Winding transformer, generating unit, bus, switched shunt, or substation contingencies. Choosing one of these options results in each contingency containing only one element of the specific type.

Bus Grouping

This feature will find groupings of buses and devices connected inside a group of branches that are explicit breakers, implicit breakers, or open branches. Contingencies are then formed from these groupings. Details of how the groupings and resulting contingencies are formed can be found with the Breaker Isolated Groups topic.

The Use branch Normal Status for groupings option is available when creating contingencies by bus groupings. This option is also described in the Breaker Isolated Groups topic.

Combination of... choice

You can also define contingencies containing multiple outages by checking the Combination of… option, and then specifying how many of each type of element (Lines, Transformers, and Generating Units) you want considered in the contingency. When you use the Combination of… option, Simulator will automatically determine all possible combinations for the element types specified (based on the settings in Optionsused to filter elements) and create the contingencies. Combination contingencies do not currently allow the inclusion of bus, switched shunt, or substation contingencies.

Restrict to Parallel or Common

These options will be enabled if choosing to do combinations where more than 1 of either a transmission line, transformer, or generator are specified.

No restrictions (All): All combinations will be created.

Common Substation: If multiple lines are to be grouped together, only combinations of lines where at least one terminal of each line is in a common substation will be included. If multiple transformers are to be grouped together, only combinations of transformers where at least one terminal of each transformer is in a common substation will be included. If multiple generators are to be grouped together, only combinations of generators that are in the same substation will be included. There is no requirement that the combinations of different types of elements are contained in the same substation. For example, combinations of lines with generators will ensure that all of the lines grouped together are in the same substations and all of the generators grouped together are in the same substation, but the groups of lines and generators grouped together can be in different substations.

Common bus: This option works the same as the Common substation option except that common objects are grouped such that they have a common bus instead of substation.

Parallel Branch (Common bus for gens): If multiple lines are grouped together, only combinations of lines where both terminal buses of the lines are the same will be grouped together. If multiple transformers are grouped together, only combinations of transformers where both terminals buses of the transformers are the same will be grouped together. If multiple generators are grouped together, only combinations of generators at the same bus will be included. There is no requirement that the combinations of different types of elements be parallel. For example, combinations of lines must be parallel but they can be combined with generators that are at a different bus than either of the line terminal buses.

Action Type to Create

Two options are available for specifying how the actions for the individual contingency elements should be defined. When defining contingency actions that involving opening an element, two formats are available: OPEN or OPEN BREAKERS TO ISOLATE. The OPEN format will implement an open action by changing the status of the affected element. The OPEN BREAKERS TO ISOLATE format will identify all breakers that should be opened in order to isolate the element. This option is very useful when using a full topology model in which breakers are identified in the case. Select the Open option to create the OPEN contingency definitions or the Open Breakers option to create the OPEN BREAKERS TO ISOLATE contingency definitions.

Options

When Simulator auto-generates the contingency records for the element types specified, the options in this section will further determine which elements are included and which elements are ignored.

Delete Existing Contingencies

When checked, any previously existing contingency records will be deleted before any automatically created contingencies are inserted.

Use Area/Zone Filters

When checked, the elements included in the auto-generated contingencies will be only elements that are within areas and zones defined in the Area/Zone/Owner Filters dialog. You may edit the Area/Zone/Owner filters by clicking on the Edit Area/Zone Filters button.

Filter using nominal voltage range

When checking the box All Voltages, then filtering by nominal voltage is not done. When this box is unchecked, then specify a Max and Min nominal voltage in kV which you would like to filter by. This filtering is done in addition to any other filtering you specify. Thus an object will only be added as a new contingency if it meets the Area/Zone, Nominal Voltage, AND the Advanced Filter specified. When filtering the nominal kV level of a transformer object which has more than one nominal voltage associated with it, then use the option Branch End to Use to specify which of these voltages to compare to the Min and Max values.

Only include … meeting an advanced filter

When checked, the branches, generators, buses, substations, switched shunts, 3-winding transformers, or line shunts included in the auto-generated contingencies will be only those elements meeting conditions outlined by an advanced filter. To set the conditions to be used, click the respective Define… Filter button.

Treatment of Transformers that are Part of 3-Windings

Options are only enabled when Single transformer, or Single transmission line or transformer is selected. The options are on how to treat the transformers that are part of a 3-Winding transformer. When a transformer branch is found during the auto insert simulator could either:

Insert winding outages separately, will insert separately the outages of the individual transformers that are part of the 3-Winding transformer object.

Insert 3-Winding transformer outages, will insert an outages of the 3-Winding transformer object instead of the outage of the individual transformers that are part of the 3-Winding transformer.

Ignore (Do not insert these outages), will ignore the outage of the transformer branches that are part of a 3-Winding transformer.

Only include elements within

When checked, only elements that are within a particular distance of the specified bus will be included when creating the contingencies. The distance measure must be chosen from the drop down with choices of Number of Nodes, X, Z, and Length. This allows integrated use of the features available from the Connections\Determine Path Distances to Buses on the tools menu of Simulator.

For example when using Number of Nodes, consider bus 1 is electrically connected to bus 2, which is in turn connected to bus 3. If we specify the bus to be bus 1, and choose to include only elements that are within 0 buses of bus 1, then the contingency record will include the branch between buses 1 and 2, and if desired any generators attached to bus 1. However, the branch between buses 2 and 3 and any devices attached to bus 2 and 3 will NOT be included in the contingency because bus 2 is electrically 1 bus away from bus 1.

To specify the bus used, you can find the bus by using the search engine. The search engine allows you to search by name or number. If you know the bus number, choose Sort by Number, and type the bus number in the search box. If you know the name of the bus, choose Sort by Name, and type the name of the bus in the search box. If you are not sure of the name of the bus, you can use wildcard characters to search through the list of buses until you find the desired bus.

How to name the contingencies

This section allows you to define how each automatically inserted contingency record will be named.

Identify … using prefix

These fields allow you to set a specific prefix for generators, lines, transformers, buses, 3-Winding transformers, switched shunts, substations, and line shunts so that you can easily determine what type or types of contingencies are modeled in the auto-generated contingency records. By default, the prefixes are L for lines, T for transformers, 3WT for 3-Winding transformers, G for generators, B for buses, S for switched shunts, SUB for substations, and LS for line shunts. However, you can change these prefixes to any character or set of characters you wish.

Identify buses by

This field allows you to specify whether each contingency is labeled using the bus numbers, bus names, both and labels (Use Numbers if no label) as identifiers. Whichever type of identifier you choose here will be combined with the defined prefixes to uniquely define the individual contingency elements within each auto-generated contingency record.

Include Nominal Voltages

When this check box is checked, the nominal voltage of buses will be included in contingency labels.

Do Insert Contingencies

Press this button to generate the contingency list once all other options have been set.

Save to Aux

Press this button to save the dialog settings to an auxiliary file so that they can be recalled for later use.

Cancel

Press this button to abandon creation of contingencies and close the dialog.