Switched Shunt Display

See Also

 

The Switched Shunt Display identifies all switched shunt devices in the case. Switched shunts are used in power systems either to inject additional Mvar into the system (capacitive shunts) or to absorb excess reactive power (inductive shunts). They may also be used to regulate bus voltage within some specified range.

The Switched Shunt Display is a class of Case Information Display and therefore can be used in a manner consistent with all other case information displays. It has a local menu from which you can print, copy, and modify its information as well as view the information dialog of its associated switched shunts. You can find a specific switched shunt using its bus name or number, and you can learn more about a particular shunt’s terminal bus by looking at the Bus View. When in Edit Mode, you can insert a new shunt into the case or delete an existing shunt. You can also sort the switched shunt information by clicking on the heading of the field by which you want to sort. Additionally, you can choose to restrict the information shown by the Load Display according to the constraints of the area/zone/owner filters.

To call up the Switched Shunt Display, select Network > Switched Shunts in the Model Explorer.

 

The Switched Shunt Display contains the following fields by default:

Number, Name

Number and name of terminal bus to which the switched shunt is attached. Multiple switched shunts are allowed at a bus and are allowed to have a Control Mode that is not fixed.

ID

Unique identifier for the switched shunt device used in conjunction with its bus identifier to fully identify the switched shunt.

Reg Bus Num

Number of the bus whose voltage is regulated by the switched shunt.

Status

The service status of the switched shunt.

Status Branch Added in Version 20

Line shunts can be modeled as controllable switched shunts by linking their status to the status of a branch. The Status Branch field specifies a branch whose status will affect the status of a switched shunt. If specified, a switched shunt can only be closed if is has a status of closed and its Status Branch also has a status of closed. If the Status Branch has a status of open, the switched shunt will also have a status of open.

To update this field, select the dialog button that appears to the far right of the cell. This will open a dialog that allows the selection of the associated branch.

Control Mode

Control Mode for the switched shunt. A switched shunt may operate either as: Fixed, Discrete, Continuous, Bus Shunt, or SVC.

See the Switched Shunt Control topic for more information on how switched shunt output is automatically adjusted during power flow solutions.

Regulates

Can be set to regulate bus voltage, generator Mvar, wind generator Mvar output, or custom control that sets the output of the switched shunt based on the result of a Model Expression.

Actual Mvar

The reactive power currently supplied by the switched shunt.

Volt High

Per unit high-voltage limit for the regulation range. It is important for discrete shunt control that Volt High exceed Volt Low by a nontrivial amount; otherwise, the output of the shunt may oscillate during the power flow solution.

Volt Low

Per unit low-voltage limit for the regulation range.

Reg Volt

Actual per unit voltage at the regulated bus. When Control Mode is either Discrete or Continuous, this voltage should be between Volt Low and Volt High.

Deviation

Deviation of the regulated bus’ actual per unit voltage from the desired regulation voltage. If the actual voltage is within the regulation range, this field is zero. If the voltage is greater than Volt High, the deviation is positive. It is negative if the actual voltage is less than Volt Low.

Nominal Mvar

The Nominal Mvar field gives the initial amount of reactive power the device would supply (in Mvars) if its terminal voltage were 1.0 per unit.

Max Mvar, Min Mvar

The maximum and minimum Mvar range for the switched shunt.