Contingency Analysis Power Flow Solution Options

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By default, the contingency analysis will use the same options as the power flow algorithm when solving each contingency. You may also override these options for all contingencies, and/or for a specific contingency. This results in the ability to set the power flow solution options in contingency analysis at three different levels (see the Contingency Combination Analysis section below for additional options when using combination analysis):

  1. Contingency Specific Options (see Contingency Definition Dialog)
  2. Contingency Analysis Options (see Contingency Options Tab)
  3. General Power Flow Solution Options (see Power Flow Solution Options)

When Simulator executes a particular contingency, it will first look at options specified for that contingency. Any options that are defined for this contingency will be used. Other options set as Use Default will look to the Contingency Analysis Options. Again, any options that are defined for contingency analysis will be used. Finally, options marked in the Contingency Analysis Options as Use Default will be set to the same setting as the power flow solution options.

In order to specify options for a specific contingency, click on the Define/Modify Solution Options button on the Contingency Definition Dialog. In order to specify options for all contingencies, click on the Define/Modify Solution Options button on the Contingency Options: Modeling/Basics page. Both of these will bring up the Contingency Analysis Power Flow Solution Options dialog.

This dialog contains many options regarding the power flow solution. For options that are a numerical value, just specify a new value to use. For options that are specified by a check-box, the check-box will have three settings: use option,do no use option, and use default. For a more detailed explanation of each option see the Power Flow Solution Options topic.

To set the values to be the same as the present power flow solution options, click the Set same as for Power Flow button. To set all options back to use default, click the Clear All Settings button.

 

The option to Dynamically Add/Remove Slack Buses as Topology is Changed (Allow Multiple Islands) is handled in a special manner when applying the contingency options. This option cannot be set to allow multiple islands if it has previously been set to not allow multiple islands. This will be enforced when the contingency solution options are applied. The main reason for having this option as part of the contingency solution options is for buses that become disconnected from the system slack bus during a contingency to form a dead island rather than selecting a new slack bus for the newly formed island and leaving it energized.

 

Contingency Combination Analysis

When running contingency combination analysis two additional levels of solution options are possible. Solution options can be specified for all primary contingencies and/or options can be specified for individual primary contingencies. Additionally the existing options with the secondary contingencies will also be used when applying secondary contingencies. This will allow the primary contingencies and secondary contingencies to be solved with different options. If options for secondary contingencies are not specified then the primary contingency options will be used for secondary contingencies as well.  Here are the levels at which solution options can be specified for combination analysis:

  1. (Secondary) Contingency Specific Options (see Contingency Definition Dialog)
  2. Contingency Analysis Options (see Contingency Options Tab)
  3. Primary Contingency Specific Options (see Contingency Primary Definition dialog)
  4. Contingency Combination Analysis Options (see Contingency Combination Analysis dialog)
  5. General Power Flow Solution Options (see Power Flow Solution Options)