Dynamic Load (Three-Phase)

Balanced three-phase dynamic load

Library:
Simscape / Electrical / Passive

Description

The Dynamic Load (Three-Phase) block models a balanced dynamic load for balanced three-phase supplies.

This table shows the relationship between the voltage from the supply, V, the active power at the P port, P_in, and the consumed active power of the block, P_actual.

Applicable Range of V Values	Applicable Range of P_in Values	Corresponding Consumed Active Power
$V > V_{\min}$	$P_{i n} > P_{\min}$	$P_{a c t u a l} = P_{i n}$
$V > V_{\min}$	$P_{i n} < P_{\min}$	$P_{a c t u a l} = P_{\min}$
$V < V_{\min}$	$P_{i n} > P_{\min}$	The block models a load with an impedance equal to: $\begin{array}{l} R = V_{\min}^{2} \frac{P_{a c t u a l}}{P_{a c t u a l}^{2} + Q_{a c t u a l}^{2}} \\ X = V_{\min}^{2} \frac{Q_{a c t u a l}}{P_{a c t u a l}^{2} + Q_{a c t u a l}^{2}} \\ Z = \sqrt{R^{2} + X^{2}} \end{array}$
$V < V_{\min}$	$P_{i n} < P_{\min}$	$P_{a c t u a l} = P_{\min}$

Where:

V_min is the value of the Minimum supply voltage (phase-to-phase RMS) parameter.
P_min is the value of the Minimum active power parameter.
P_actual is the consumed active power of the Dynamic Load (Three-Phase) block.
Q_actual is the consumed reactive power of the Dynamic Load (Three-Phase) block.

The consumed reactive power of the block is equal to the Q port as long as the voltage from the supply is equal to or greater than the value specified for the Minimum supply voltage (phase-to-phase RMS) parameter. Otherwise, the block models a load with an impedance equal to:

$\begin{array}{l} R = V_{\min}^{2} \frac{P_{a c t u a l}}{P_{a c t u a l}^{2} + Q_{a c t u a l}^{2}} \\ X = V_{\min}^{2} \frac{Q_{a c t u a l}}{P_{a c t u a l}^{2} + Q_{a c t u a l}^{2}} \\ Z = \sqrt{R^{2} + X^{2}} \end{array}$

Faults

The Dynamic Load (Three-Phase) block allows you to model an electrical fault as an open circuit. The block can trigger fault events at a specific time.

You can also choose whether to issue an assertion when a fault occurs by using the Reporting when a fault occurs parameter. The assertion can take the form of a warning or an error. By default, the block does not issue an assertion.

Load-Flow Analysis

If the block is in a network that is compatible with the frequency-time simulation mode, you can perform a load-flow analysis on the network. A load-flow analysis provides steady-state values that you can use to initialize a machine.

For more information, see Perform a Load-Flow Analysis Using Simscape Electrical and Frequency and Time Simulation Mode.

Ports

Input

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`P` — Real power
physical signal

Physical signal port associated with real power, specified as a scalar.

`Q` — Reactive power
physical signal

Physical signal port associated with reactive power, specified as a scalar.

Conserving

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`~` — Three-phase voltage
electrical

Expandable electrical conserving port associated with the three-phase voltage.

Parameters

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Main

`Minimum supply voltage (phase-to-phase RMS)` — Minimum supply voltage
`100` `V` (default) | scalar

Minimum voltage, in phase-to-phase RMS, that the supply needs to give the block so that it acts as a dynamic load.

`Minimum active power` — Minimum active power
`1e-3` `W` (default) | scalar

Minimum active power.

Faults

`Enable open circuit fault` — Whether to enable fault modeling
`No` (default) | `Yes`

Select Yes to enable fault modeling and expose the associated parameters in the Faults section, which enables you to select the reporting method and specify the time at which the fault triggers.

`Reporting when a fault occurs` — Whether to issue assertion when fault occurs
`None` (default) | `Warn` | `Error`

Choose whether to issue an assertion when a fault occurs:

None — The block does not issue an assertion.
Warn — The block issues a warning.
Error — Simulation stops with an error.

Dependencies

To enable this parameter, set Enable open circuit fault to Yes.

`Time at which fault is triggered` — Time before entering faulted state
`1` `s` (default) | scalar

Simulation time when the block enters the faulted state.

Dependencies

To enable this parameter, set Enable open circuit fault to Yes.

`Open-circuit conductance` — Open-circuit conductance
`1e-4` `S` (default) | scalar

Conductance during the open-circuit state.

Dependencies

To enable this parameter, set Enable open circuit fault to Yes.

Compatibility Considerations

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Library Path Change

Behavior changed in R2020b

The Dynamic Load (Three-Phase) block has been moved from the Simscape > Electrical > Passive > RLC Assemblies library to the Simscape > Electrical > Passive library.

If you have a script that depends on the library path or the Simscape component path of this block, you need to update it to reflect these changes.

Documentation

Dynamic Load (Three-Phase)

Description

Faults

Load-Flow Analysis

Ports

Input

`P` — Real power
physical signal

`Q` — Reactive power
physical signal

Conserving

`~` — Three-phase voltage
electrical

Parameters

Main

`Minimum supply voltage (phase-to-phase RMS)` — Minimum supply voltage
`100` `V` (default) | scalar

`Minimum active power` — Minimum active power
`1e-3` `W` (default) | scalar

Faults

`Enable open circuit fault` — Whether to enable fault modeling
`No` (default) | `Yes`

`Reporting when a fault occurs` — Whether to issue assertion when fault occurs
`None` (default) | `Warn` | `Error`

Dependencies

`Time at which fault is triggered` — Time before entering faulted state
`1` `s` (default) | scalar

Dependencies

`Open-circuit conductance` — Open-circuit conductance
`1e-4` `S` (default) | scalar

Dependencies

Compatibility Considerations

Library Path Change

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.

See Also

Simscape Electrical Documentation

Support

Documentation

Dynamic Load (Three-Phase)

Description

Faults

Load-Flow Analysis

Ports

Input

P — Real power physical signal

Q — Reactive power physical signal

Conserving

~ — Three-phase voltage electrical

Parameters

Main

Minimum supply voltage (phase-to-phase RMS) — Minimum supply voltage 100 V (default) | scalar

Minimum active power — Minimum active power 1e-3 W (default) | scalar

Faults

Enable open circuit fault — Whether to enable fault modeling No (default) | Yes

Reporting when a fault occurs — Whether to issue assertion when fault occurs None (default) | Warn | Error

Dependencies

Time at which fault is triggered — Time before entering faulted state 1 s (default) | scalar

Dependencies

Open-circuit conductance — Open-circuit conductance 1e-4 S (default) | scalar

Dependencies

Compatibility Considerations

Library Path Change

Extended Capabilities

C/C++ Code Generation Generate C and C++ code using Simulink® Coder™.

See Also

Simscape Electrical Documentation

Support

`P` — Real power
physical signal

`Q` — Reactive power
physical signal

`~` — Three-phase voltage
electrical

`Minimum supply voltage (phase-to-phase RMS)` — Minimum supply voltage
`100` `V` (default) | scalar

`Minimum active power` — Minimum active power
`1e-3` `W` (default) | scalar

`Enable open circuit fault` — Whether to enable fault modeling
`No` (default) | `Yes`

`Reporting when a fault occurs` — Whether to issue assertion when fault occurs
`None` (default) | `Warn` | `Error`

`Time at which fault is triggered` — Time before entering faulted state
`1` `s` (default) | scalar

`Open-circuit conductance` — Open-circuit conductance
`1e-4` `S` (default) | scalar

C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.