Description

In order to decrease the calculation load, the task of a complex station can be divided into two or more sub-tasks using decoupling elements. The decoupling element can be used either in 1-phase or 3-phase neworks, except when using the Line type that is only supported in 3-phase networks. The decoupling element replaces a reactor between two power systems to be decoupled.

Table of Contents

Mask and Parameters

General Parameters:

Description: Use this field to add all kinds of information about the component
Decoupling type: V/V, V/I or Line (more information further below)
Base power (total): Base value pour PU conversion (MVA)
Base voltage: Base value pour PU conversion (kV)
- rmsLL if connected to 3-ph bus
- rmsLN if only one phase is connected
Base frequency: Base value pour PU conversion (Hz)

Parameters for all Types:

Rs: Series resistance; given per phase in V/V and V/I types and per sequence in Line type (ohm)
Ls: Series inductance; given per phase in V/V and V/I types and per sequence in Line type (H)

Parameters for V/V and V/I Types:

Grounded phase: Leave blank if no phase is grounded
Prediction use:

Parameters for Line Type:

Cs: Total line capacitance ; given per sequence (do not modify this value, it's computed automatically upon building the topology)
Cs reactive power: Total line capacitance reactive power (do not modify this value, it's computed automatically upon building the topology)

Ports, Inputs, Outputs and Signals Available for Monitoring

Ports

V: Voltage source side
V/I: Voltage or current source side, depending on the selected decoupling type

Both ports are power flexible, which means that they will automatically adapt to the number of phases of the network where they are connected (1-phase or 3-phase).

Inputs

None

Outputs

None

Sensors

I: Current in (A) when using in a 1-phase network
I(a,b,c): Current in (A) for each phase when using in a 3-phase network

Applications

Hint: A good way for decoupling a substation is by replacing the leakage impedance of the substation transformer by a decoupling element in series with the primary winding of the transformer and to transfer the parameter values from one to the other. Be careful though, as depending on the short-circuit power of the simulated network, it may or may not work.

Below are two uses of the decoupling element in a 3-phase power system.