Components and parameters > Branches

A reactance coil is a three-phase impedance between two nodes. The reactance coil is often used at the beginning of a medium-voltage feeder to the limit short-circuit current. The electrical properties are sometimes copied from the type file.

With a reactance coil, the nominal voltages of both nodes must be the same.

PARAMETERS

General

Parameter	Description
Name	Name of reactance coil

The reactance coil runs from the From-node towards the To-node. The From-node and the To-node of the reactance coil are determined automatically. To switch the From-node and the To-node use the <> button.

Reactance coil

Parameter	Default	Unit	Description
Type			Reactance coil type definition
Short			Short name
Unom	1)	kV	Nominal voltage
Ik (2 s)	0	kA	Admissible short-circuit current for 2 seconds
Inom	0	A	Nominal current
R	0	Ohm	Resistance
X	0	Ohm	Reactance
R0	0	Ohm	Zero sequence Resistance
X0	0	Ohm	Zero sequence Reactance
R2	0	Ohm	Inverse Resistance
X2	0	Ohm	Inverse Reactance

1) Unom of the nodes between which the reactance coil is located

Z0 becomes Z1 (Z1 -> Z0)

Using this button the contents of the normal impedance will be copied to the zero sequence impedance.

Z2 becomes Z1 -> Z2

Using this button the contents of the zero sequence impedance will be copied to the inverse sequence impedance.

Reliability

Parameter	Default	Unit	Description
Failure frequency	0	per year	Mean number of occurrences that the reactance coil fails (short circuit)
Repair duration	0	minutes	Mean duration of repair or replacement
Maintenance frequency	0	per year	Mean number of occurrences that the reactance coil is in maintenance
Maintenance duration	0	minutes	Mean duration of maintenance
maint. cut-off duration	0	minutes	Mean duration of cancellation of maintenance in case of emergency

MODELLING

For all calculations the reactance coil is modelled as a longitudinal impedance R+jX.

Inom'

For branches the terms Inom' and Snom' have been introduced for signalling an overload in the load flow. These values have been introduced to obtain clarity about the maximum load capacity of a branch. Inom' is specified as follows for the reactance coil:

•Inom' is taken from the input data Reactancecoiltype.Inom