Fault (Three-Phase)

Short circuit: single-, two-, or three-phase, as well as ground fault.

blockType: AcausalElectricPowerSystems.Utilities.ThreePhaseFault

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/Physical Modeling/Electrical/Utilities/Fault (Three-Phase)

Description

Block Fault (Three-Phase) simulates any combination of one-, two-, or three-phase short circuit and ground fault.

The unit can cause a short circuit (short circuit) both in time and in event. The unit can trigger one or both types of short circuits sequentially, at the same time, or over an overlapping period of time.

For a time-based short circuit, specify the short circuit activation time using the parameter Fault start time. The short circuit becomes inactive after the specified short circuit duration has expired.

For an event-based short circuit, specify the short circuit activation threshold using the Threshold block parameter. The external control signal F controls the short circuit.

The block can simulate the following combinations:

Single-phase short circuit to ground ( - , - or - );
Two-phase short circuit ( - , - or - );
Two-phase short circuit to ground ( - - , - - or - - );
Three-phase short circuit ( - - );
Three-phase short circuit to ground ( - - - ).

The figure below shows the equivalent electrical circuit of the unit.

To determine the resistance in an equivalent circuit, use the corresponding equations from the table below.

Short circuit mode

Value

No / inactive

Infinity/Open circuit

Single-phase (to ground)

Two-phase

Infinity/Open circuit

Two-phase to ground

- -

Three-phase

- -

Infinity/Open circuit

Three-phase to ground

- - -

In the table:

— resistance between -the phase and the neutral point of the star junction;
— resistance between -the phase and the neutral point of the star junction;
— resistance between -the phase and the neutral point of the star junction;
— resistance between the neutral point of the star connection and the electrical ground;
— parameter value Faulted phase-neutral resistance;
— parameter value Faulted neutral-ground resistance;
— parameter value Unfaulted phase-neutral conductance.

Ports

Conserving

# ~ — three-phase port
electricity

Details

Three-phase electrical port for connecting the unit to the circuit.

Program usage name

port

Output

# X — short circuit status
scalar

Details

Signal output port for short circuit status message:

1 — short circuit;
0 — no changes.

Dependencies

To use this port, check the box State port.

Data types	`Float64`
Complex numbers support	No

Input

# F — external short circuit call
scalar

Details

An external signal to call the short circuit.

Dependencies

To use this port, check the box Enable external fault trigger.

Data types	`Float64`
Complex numbers support	No

Parameters

Main

# Enable zero crossing — choosing a replacement scheme

Details

This parameter defines the way to turn off the current: instantly (if the checkbox is unchecked) or when passing through zero (if the checkbox is checked).

Select this option to use a replacement circuit in the form of three single-phase switches. Circuit Breaker which can be individually switched on and off to program phase-to-phase circuits, ground circuits, or a combination of phase-to-phase and ground circuits. The process of extinguishing the arc of the block Fault (Three-Phase) the same as for the block Circuit Breaker.

Below is a diagram that illustrates how the block works when the checkbox is Enable zero crossing installed. This circuit is not an equivalent block circuit.

fault (three phase) 1 2

Default value	`false (switched off)`
Program usage name	`enable_zero_crossing`
Evaluatable	No

Details

The type of short circuit for modeling. The following options are available:

None — KZ is missing;
Single-phase to ground (a-g);
Single-phase to ground (b-g);
Single-phase to ground (c-g);
Two-phase (a-b);
Two-phase (b-c);
Two-phase (c-a);
Two-phase to ground (a-b-g);
Two-phase to ground (b-c-g);
Two-phase to ground (c-a-g);
Three-phase (a-b-c);
Three-phase to ground (a-b-c-g).

Values	`None` \| `Single-phase to ground (a-g)` \| `Single-phase to ground (b-g)` \| `Single-phase to ground (c-g)` \| `Two-phase (a-b)` \| `Two-phase (b-c)` \| `Two-phase (c-a)` \| `Two-phase to ground (a-b-g)` \| `Two-phase to ground (b-c-g)` \| `Two-phase to ground (c-a-g)` \| `Three-phase (a-b-c)` \| `Three-phase to ground (a-b-c-g)`
Default value	`None`
Program usage name	`type`
Evaluatable	No

# Faulted phase-neutral resistance — phase-neutral circuit resistance at short circuit
Ohm | mOhm | kOhm | MOhm | GOhm

Details

The resistance between the phase and the neutral point when the short circuit is active.

Dependencies

To use this parameter, set for the parameter Failure mode one of the values is:

Single-phase to ground (a-g);
Single-phase to ground (b-g);
Single-phase to ground (c-g);
Two-phase (a-b);
Two-phase (b-c);
Two-phase (c-a);
Two-phase to ground (a-b-g);
Two-phase to ground (b-c-g);
Two-phase to ground (c-a-g);
Three-phase (a-b-c);
Three-phase to ground (a-b-c-g).

Units	`Ohm` \| `mOhm` \| `kOhm` \| `MOhm` \| `GOhm`
Default value	`1e-3 Ohm`
Program usage name	`R_pn`
Evaluatable	Yes

# Faulted neutral-ground resistance — resistance of the neutral-ground circuit at short circuit
Ohm | mOhm | kOhm | MOhm | GOhm

Details

Resistance between the neutral point and the ground when the short circuit is active.

Dependencies

To use this parameter, set for the parameter Failure mode one of the values is:

Single-phase to ground (a-g);
Single-phase to ground (b-g);
Single-phase to ground (c-g);
Two-phase to ground (a-b-g);
Two-phase to ground (b-c-g);
Two-phase to ground (c-a-g);
Three-phase to ground (a-b-c-g).

Units	`Ohm` \| `mOhm` \| `kOhm` \| `MOhm` \| `GOhm`
Default value	`1e-3 Ohm`
Program usage name	`R_ng`
Evaluatable	Yes

# State port — enable the short circuit status port

Details

Select this option to use the short circuit status port X.

Default value	`false (switched off)`
Program usage name	`expose_measurement`
Evaluatable	No

External Trigger

# Enable external fault trigger — short circuit start by external signal

Details

Select this checkbox to enable the start of the short circuit on an external signal F.

Default value	`false (switched off)`
Program usage name	`external`
Evaluatable	No

# Fault threshold — the threshold value that causes a short circuit

Details

A short circuit occurs when an external signal crosses the threshold value in the direction specified in the short circuit condition (External fault trigger).

Dependencies

To use this option, check the box Enable external fault trigger.

Default value	`0.5`
Program usage name	`control_signal_threshold`
Evaluatable	Yes

# External fault trigger — the condition for the short circuit
Faulted if F ≥ Fault threshold | Faulted if F ≤ Fault threshold

Details

Select the condition that causes a short circuit:

Faulted if F ≥ Fault threshold — Short circuit occurs when the value of the external signal becomes greater than or equal to the value of the parameter Fault threshold;
Faulted if F ≤ Fault threshold — Short circuit occurs when the value of the external signal becomes less than or equal to the value of the parameter Fault threshold.

Dependencies

To use this option, check the box Enable external fault trigger.

Values	`Faulted if F ≥ Fault threshold` \| `Faulted if F ≤ Fault threshold`
Default value	`Faulted if F ≥ Fault threshold`
Program usage name	`condition`
Evaluatable	No

# Fault resets when fault trigger reverts — short circuit termination when the trigger signal is restored

Details

Select this checkbox to terminate the short circuit at the moment when the value of the external signal F ceases to satisfy the condition External fault trigger.

Dependencies

To use this option, check the box Enable external fault trigger.

Default value	`false (switched off)`
Program usage name	`resettable`
Evaluatable	No

Temporal Trigger

# Enable temporal fault trigger — time limit start-up

Details

Select this option to enable the time limit start.

Default value	`false (switched off)`
Program usage name	`temporal`
Evaluatable	No

# Fault start time — short circuit start time
s | ns | us | ms | min | hr | d

Details

The simulation time at which the block switches to the short circuit state.

_ Dependencies_

To use this option, check the box Enable temporal fault trigger.

Units	`s` \| `ns` \| `us` \| `ms` \| `min` \| `hr` \| `d`
Default value	`1.0 s`
Program usage name	`start_time`
Evaluatable	Yes

# Fault duration — duration of short circuit
s | ns | us | ms | min | hr | d

Details

The time of the simulation duration is short. The unit exits the short circuit state after the set time has elapsed.

Dependencies

To use this option, check the box Enable temporal fault trigger.

Units	`s` \| `ns` \| `us` \| `ms` \| `min` \| `hr` \| `d`
Default value	`0.1 s`
Program usage name	`duration`
Evaluatable	Yes

Parasitics

# Unfaulted phase-neutral conductance — the conductivity between the intact phase and the neutral point
S | nS | uS | mS | 1/Ohm

Details

The conductivity between the intact phase and the neutral point.

Units	`S` \| `nS` \| `uS` \| `mS` \| `1/Ohm`
Default value	`1e-6 1/Ohm`
Program usage name	`G_pn`
Evaluatable	Yes

Fault (Three-Phase)

Description

Ports

Conserving

Output

Input

Parameters

Main

External Trigger

Temporal Trigger

Parasitics

Examples