Dynamic Load (Three-Phase, DQ0)

R2026b

Balanced three-phase dynamic load in direct-quadrature-zero reference frame

Since R2026b

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Dynamic Load (Three-Phase, DQ0) block

To add a block to a model, double-click the canvas and start typing the block name. Then, select the block from the list.

Libraries:
Simscape / Electrical / DQ0 Components / Passive

Description

The Dynamic Load (Three-Phase, DQ0) block models a dynamic load for a three-phase supply in the direct-quadrature-zero (dq0) reference frame.

Equations

This table shows how the block calculates the consumed active and reactive power based on the voltage from the supply, V.

Range of V Values	Consumed Active and Reactive Power
$$V>V_{\min }$$	$$\begin{array}{l}{P}_{actual}=P_{in}\\ Q_{actual}=Q_{in}\end{array}$$
$$V<V_{\min }$$	The block models a load with an impedance equal to: $$\begin{array}{l}R=V_{\min }^2\frac{P_{in}}{P_{in}^2+Q_{in}^2}\\ X=V_{\min }^2\frac{Q_{in}}{P_{in}^2+Q_{in}^2}\\ Z=\sqrt{R^2+X^2}\end{array}$$

In these equations:

• V_min is the value of the Minimum supply voltage (phase-to-phase RMS) parameter.

• P_actual is the consumed active power of the block.

• P_in is the input active power of the block as specified at input port P.

• Q_actual is the consumed reactive power of the block.

• Q_in is the input reactive power of the block as specified at input port Q.

The Dynamic Load (Three-Phase, DQ0) block consumes or generates active power depending on the polarity of the input active power P_in. If P_in > 0, the block consumes active power. If P_in < 0, the block generates active power.

When you set the Zero sequence parameter to Include, the block models zero-sequence circuit as an RL load,

$$v_0=R_0{i}_0+L_0\frac{d{i}_0}{dt},$$

where:

• R₀ is the zero-sequence resistance and is equal to the value of the Zero-sequence resistance parameter.

• L₀ is the zero-sequence inductance and is equal to the value of the Zero-sequence inductance parameter.

Faults

To model a fault in the Dynamic Load (Three-Phase, DQ0) block, in the Faults section, click Add fault next to the fault that you want to model. For more information about fault modeling, see Fault Behavior Modeling and Fault Triggering.

The Dynamic Load (Three-Phase, DQ0) block allows you to model an electrical fault as an open circuit. You specify how and when faults occur by using the Trigger type parameter.

For more information about adding faults to blocks and specifying fault triggers, see Introduction to Simscape Faults.

Assumptions and Limitations

The block defines the dq0 quantities in the synchronous reference frame using the standard power-variant form. For more information about the Park transform, see Park Transform.

Ports

Input

P — Real power, W

physical signal

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

Q — Reactive power, V*A

physical signal

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

Conserving

Note

The d, q, and 0 ports are electrical conserving ports that represent three‑phase quantities expressed in the rotating reference (dq0) frame. Connecting these ports to components outside the dq0 domain requires appropriate transformations to avoid modeling inconsistencies.

d — d-axis voltage

electrical

Electrical conserving port associated with the d-axis voltage.

q — q-axis voltage

electrical

Electrical conserving port associated with the q-axis voltage.

0 — Zero-sequence component

electrical

Electrical conserving port associated with the zero-sequence component.

Dependencies

To enable this port, set Zero sequence to Include.

Parameters

Main

Zero sequence — Option to include zero-sequence component

Include (default) | Exclude

Option to include or exclude the zero-sequence component.

Minimum supply voltage (phase-to-phase RMS) — Minimum supply voltage

100 V (default) | scalar

Minimum root mean squared (RMS) voltage between phases that the supply needs for the block to act as a dynamic load.

Voltage time constant — Time constant associated with transients of terminal voltage measurement

0.01 s (default) | positive scalar

Time constant associated with the transients of the terminal voltage measurement.

Initial supply voltage (phase-to-phase RMS) — Terminal voltage at time zero

200 V (default) | positive scalar

RMS terminal voltage between phases at time zero.

Initial supply voltage angle — Terminal voltage angle of phase A at time zero

0 deg (default) | scalar

Terminal voltage angle of phase A at time zero.

Zero-sequence resistance — Zero-sequence resistance

1e-6 Ohm (default) | nonnegative

Zero-sequence resistance.

Dependencies

To enable this parameter, set Zero Sequence to Include.

Zero-sequence inductance — Zero-sequence inductance

1e-6 H (default) | positive scalar

Zero-sequence inductance.

Dependencies

To enable this parameter, set Zero Sequence to Include.

Faults

Open circuit fault — Option to add open-circuit fault

Add fault (default)

Option to add an open-circuit fault in the Dynamic Load (Three-Phase, DQ0) block.

To add a fault, click the Add fault hyperlink.

Open-circuit conductance — Open-circuit conductance

1e-4 S (default) | scalar

Conductance during the open-circuit state.

Dependencies

To enable this parameter, click the Add fault hyperlink for the Open circuit fault parameter.

Trigger type — Trigger type

Always on (default) | Timed | Additional triggers | Conditional | Manual

Trigger type, specified as one of these options:

• Always On — The fault injects at the start of the simulation.

• Timed — The fault injects when the simulation time reaches the value you specify for the Trigger fault at time parameter.

• Additional triggers — The fault injects as a result of additional triggers not available in the block dialog box. Select this option and click the Open fault properties hyperlink to set the Trigger type to one of these values in the Property Inspector:

  • Conditional — The fault injects as a result of a condition that reflects a behavior associated with a signal. Conditionals evaluate the Boolean expression in the Condition parameter at each time step. To learn more, see Create and Manage Conditionals.

  • Manual — The fault injects or clears when you toggle the status in the Fault Dashboard pane. To learn more, see Manually Trigger Faults in Models.

Dependencies

To enable this parameter, click the Add fault hyperlink for the Open circuit fault parameter.

Trigger fault at time — Time before entering faulted state

0 s (default) | nonnegative scalar

Simulation time at which the block enters the faulted state.

Dependencies

To enable this parameter, click the Add fault hyperlink for the Open circuit fault parameter and set Trigger type to Timed.

Trigger Configuration — Option to enable additional trigger types

Open fault properties

Option to enable additional trigger types not available in the block dialog box. To set the Trigger type parameter to Conditional or Manual, click the Open fault properties hyperlink and set the Trigger type in the Property Inspector.

Dependencies

To enable this parameter, click the Add fault hyperlink for the Open circuit fault parameter and set Trigger type to Additional triggers.

Extended Capabilities

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

Version History

Introduced in R2026b