Capacitors

Capacitor types available in DEW are Fixed Capacitors and Regulating Capacitors.

See General Dialog Details for information on common dialog fields and commands, as only the highlighted fields and commands unique to the capacitor dialog are addressed in this topic.  

The Capacitor properties dialog, shown below for a Regulating Capacitor, is generally common for all capacitors, except that Fixed Capacitor dialogs do not have the [Controller] command.  

Capacitor-Unique Fields:

Switch Status:

• Turn OFF Capacitor - allows user to manually disconnect the capacitor from circuit.  Note: Regulating capacitors may also be switched On and Off by the Controller/Application.  

Number of Units [___] - specifies the number of capacitors installed at the given location.

Capacitor Controls:

The [Controller] command button found on the main component property dialogs of Regulating Capacitors launches the Capacitor Controller dialog, which is used to specify:

Control Type:

• Allowed to Move - Select to allow automatic control action to occur.  When unselected, the automatic controller is frozen at the user specified setting.

• Switched - selection for a switched capacitor bank, which can only be all-ON or all-OFF.  The Number of Steps is automatically set to 1.

• Multiple Step - Multiple step capacitor banks can have two or more steps, as defined from the parts database.    

Description - provides the general description for the selected item in the Controlled Variable drop-down.

Controlled Variable - specifies the variable being controlled.  Available selections are:

Control Settings:
 

[Set Time Controls] - when applicable, opens dialog that allows user to define operating period for capacitor.  See following (Time Control Setup Dialog) for more details.  

Number of Steps [___] - when applicable, i.e. for multi-step capacitor types, defines the number of steps.  Note: The number of steps selected must be an integer divisor of the number of units available in the bank.
 

Current Step for Phase - displays application results when automatically controlled, or allows user to manually specify the step (per phase) when the Allowed to Move option is unselected.  Note: Specified step cannot exceed the Number of Steps indicated.  A step of zero indicates that the bank is OFF.

Setpoints (Customer Voltage, or etc):

Lower [___] - defines lower limit of acceptable range for the specified control variable.

Upper [___] - defines the upper limit of acceptable range for the specified control variable.  

 
Notes:

-  Voltage control limits, in Volts, are specified in terms of customer level voltage.
-  Power Factor control may be specified either as Lagging (0.0 to 1.0) or as Leading (-1.0 to 0.0).
-  Temperature control limits are specified in degrees F.
-  Phase C current limits, which base control only on the single (C) phase, are specified (in Amps) for each season (i.e. Summer/Winter).

Override (Cust Volt):

Only applicable when using Power Factor Control, this option allows user to override the power factor control in order to meet specified voltage requirements.   

• None - Must be Unselected to use Voltage Override.  When selected, Voltage Override control is not active.

Lower [___] - specifies the lower acceptable voltage limit, below which voltage control begins overriding power factor control.

Upper [___] - specifies the upper acceptable voltage limit, above which voltage control begins overriding power factor control.

 
Notes:

-  The setpoints are specified in terms of customer level voltage, with the controlling voltage measurement taken at the same point in the system as the power factor measurement.
-  In the override mode, once voltage has returned to within the specified range, power factor control resumes.

Control Location:
 

Pick Voltage / Power Factor Measurement:
 

[Specify Graphically] - allows mouse (pointer finger) selection of the circuit location where specified control variable will be controlled to the specified range.

{Drop Down Window} - provides drop down list for specifying the circuit control location.  If the selection is made via the mouse pointer, as described above, then the window displays the selected component/location.

 
Notes:

-  The default measurement location is at the regulating capacitor bank.
-  The measured value of the customer level voltage is determined from the distribution transformer turns ratio located close to the voltage measurement.
-  If a line/cable section is specified for the voltage measurement, then the turns ratio of the distribution transformer attached to the line/cable section is used.
-  The Load Button on the Line or Cable dialogs may be used to access the Distribution Transformer Turns Ratio specification.

Time Control Setup Dialog:

The time control (Capacitor Controller: Control) dialog is only used for setting up Time Controlled capacitors.  

Operation Period:
 

Type of Month - allows selection of months when the time controlled capacitor may be turned on.  As above,  may only be turned on during summer months (June, July, August).  

Type of Day - allows selection for types of day during the specified (ON) months that capacitor is turned on.  As above, "On" operation is restricted to summer weekdays.  

[Select All] - Selects all selections in applicable list box, i.e. Month or Day.  

[Unselect All] - Unselects all selections in applicable list box, i.e. Month or Day.
 

Time (Hrs):

Turn On [___] - specifies the hour of day during selected period that the time-controlled capacitor turns On.  

Turn Off [___] - specifies the hour of day during selected period that the time-controlled capacitor turns Off.
 

Note: If the capacitor is to be on for twenty-four hours a day, then specified hours for Turn On and Turn Off are set to the same value, as shown above with both set for 12 AM.