Utility - Power Flow Tab

Option Descriptions
Option	Description
Model	Utility bus type used in modeling the power flow simulation. When you choose a particular model, those fields which do not apply become unavailable. A utility is normally modeled as the reference or swing bus, but may be modeled as another generator bus. See Swing Sources for more information. Swing - A swing bus holds the bus voltage and angle constant. There cannot be limits on the amount of MW or MVAR the swing machine can accept or provide. PV - Constant power, constant voltage utility. This is also known as a regulated utility. This model tries to hold a user-specified bus voltage within utility MVAR limits. PQG - Constant power, constant var utility. This is also known as an unregulated utility. This model holds the MVAR generation within given voltage limits.
MW	Utility output MW. This may be actual operating or a rated value. This applies only to a PV or PQG utility.
MVAR	Utility output MVAR. This is only used when the utility is a constant power, constant var (PQG) machine, or when a PV utility MVAR limit has been reached and the machine automatically switches to PQG.
MVAR Limits	Minimum and maximum MVAR limits for regulated utilities (PV). The utility will switch to type PQG if these limits are violated. If there is only one swing utility (Model = Swing) on a bus, it should not have any MVAR limits. If there is more than one swing utility on a bus, at least one of them must be unlimited.
Ctl kV PU	Desired control voltage for a regulated utility (PV). The utility will try to control the voltage at the controlled bus to a given value. If the utility bus is the swing bus, this voltage serves as the reference voltage. The voltage is entered in per-unit.
Ctl Angle	Controlled angle is used only when a utility is designated as a swing bus. The value is entered in degrees.
Ctrl Bus	For a PV utility (regulated), the bus that is to be controlled to the control voltage. If this field is blank in the database, EasyPower fills it in with the name of the bus listed in the To Bus field. (This does not take effect until you click OK to close the database dialog box.) This field is ignored if the Model field is set to Swing Note: To set the control bus for a single-phase utility or generator, you must make the connection on the one-line. .

Model

Utility bus type used in modeling the power flow simulation. When you choose a particular model, those fields which do not apply become unavailable. A utility is normally modeled as the reference or swing bus, but may be modeled as another generator bus. See Swing Sources for more information.

Swing - A swing bus holds the bus voltage and angle constant. There cannot be limits on the amount of MW or MVAR the swing machine can accept or provide.
PV - Constant power, constant voltage utility. This is also known as a regulated utility. This model tries to hold a user-specified bus voltage within utility MVAR limits.
PQG - Constant power, constant var utility. This is also known as an unregulated utility. This model holds the MVAR generation within given voltage limits.

MW

Utility output MW. This may be actual operating or a rated value. This applies only to a PV or PQG utility.

MVAR

Utility output MVAR. This is only used when the utility is a constant power, constant var (PQG) machine, or when a PV utility MVAR limit has been reached and the machine automatically switches to PQG.

MVAR Limits

Minimum and maximum MVAR limits for regulated utilities (PV). The utility will switch to type PQG if these limits are violated. If there is only one swing utility (Model = Swing) on a bus, it should not have any MVAR limits. If there is more than one swing utility on a bus, at least one of them must be unlimited.

Ctl kV PU

Desired control voltage for a regulated utility (PV). The utility will try to control the voltage at the controlled bus to a given value. If the utility bus is the swing bus, this voltage serves as the reference voltage. The voltage is entered in per-unit.

Ctl Angle

Controlled angle is used only when a utility is designated as a swing bus. The value is entered in degrees.

Ctrl Bus

For a PV utility (regulated), the bus that is to be controlled to the control voltage. If this field is blank in the database, EasyPower fills it in with the name of the bus listed in the To Bus field. (This does not take effect until you click OK to close the database dialog box.) This field is ignored if the Model field is set to Swing

Note: To set the control bus for a single-phase utility or generator, you must make the connection on the one-line. .

Utility - Power Flow Tab

DC Utility Power Flow Tab

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