Utility - Specifications Tab

See also: DC Utility Specifications Tab

Figure 1: Specifications Tab (3-Phase)

Figure 2: Specifications Tab (1-Phase)

Option Descriptions
Option Description

Utility kV

The Utility kV field represents the maximum voltage between conductors in a utility supply. This value is used in calculation of per-unit impedance. This does not affect the power flow controlled voltage.

The Utility kV displays line-to-line (LL) voltage for a 3-Phase or line-to-line connected single-phase utility that has the conductors AB, BC, or CA. For line-to-ground or line-to-neutral connected single-phase system such as AN, BN, or CN, the Utility kV is line-to-neutral (LN) voltage. For a 1PH-3W system, enter the line-to-line voltage.

Fault Duty Unit

Specifies the unit in which the short circuit information is entered. Any of the four following units may be selected:

  • MVA
  • kA
  • Ohms
  • Zpu

See the Fault Duty Unit table below for more information.

Utility MVA Base

When Zpu is selected as the fault duty unit, you also need to specify the MVA Base of the utility for the per unit values.

3-Phase / 1-Phase Short Circuit

Used in determining short circuit reactance and resistance values for 3-phase faults and line-to-line faults.

For a single phase utility this is the available fault value.

See the Fault Duty Unit table below for more information.

SLG Short Circuit

Used in determining short circuit reactance and resistance values for single line-to-ground faults.

See the Fault Duty Unit table below for more information.

Fault Duty Units

Fault Duty Units
Fault Duty Short Circuit Values

MVA

MVA: Used for 3-Phase, SLG, or LL faults
  • X/R: Positive sequence reactance to resistance ratio
  • X0/R0: Zero sequence reactance to resistance ratio
kA

kA: Used for 3-Phase, SLG, or LL faults
  • X/R: Positive sequence reactance to resistance ratio
  • X0/R0: Zero sequence reactance to resistance ratio
Ohms
  • R: Positive sequence resistance in Ohms
  • R0: Zero sequence resistance in Ohms
  • jX: Positive sequence reactance in Ohms
  • jX0: Zero sequence reactance in Ohms
Zpu
  • Rpu: Positive sequence resistance in per unit
  • R0pu: Zero sequence resistance in per unit
  • jXpu: Positive sequence reactance in per unit
  • jX0pu: Zero sequence reactance in per unit

DC Utility Specifications Tab

Figure 3: DC Utility Specifications

Option Descriptions
Option Description

kV

DC Utility operating kV. If this value is different than the bus base kV, then the controlled voltage is scaled appropriately.

Fault Duty

Expected fault value (in amperes) or the Thevenin equivalent resistance (in ohms) at the DC utility connection point.

More Information