# Dynamic Load (Three-Phase)

**Libraries:**

Simscape /
Electrical /
Passive

## Description

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

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 |
---|---|

$$V>{V}_{\mathrm{min}}$$ | $$\begin{array}{l}{P}_{actual}={P}_{in}\\ {Q}_{actual}={Q}_{in}\end{array}$$ |

$$V<{V}_{\mathrm{min}}$$ | The block models a load with an impedance equal to: $$\begin{array}{l}R={V}_{\mathrm{min}}^{2}\frac{{P}_{in}}{{P}_{in}^{2}+{Q}_{in}^{2}}\\ X={V}_{\mathrm{min}}^{2}\frac{{Q}_{in}}{{P}_{in}^{2}+{Q}_{in}^{2}}\\ Z=\sqrt{{R}^{2}+{X}^{2}}\end{array}$$ |

In these equations:

*V*is the value of the Minimum supply voltage (phase-to-phase RMS) parameter._{min}*P*is the consumed active power of the Dynamic Load (Three-Phase) block._{actual}*P*is the input active power of the Dynamic Load (Three-Phase) block, determined by external input port_{in}**P**.*Q*is the consumed reactive power of the Dynamic Load (Three-Phase) block._{actual}*Q*is the input reactive power of the Dynamic Load (Three-Phase) block, determined by external input port_{in}**Q**.

The Dynamic Load (Three-Phase) block consumes or generates
active power depending on the polarity of input active power
*P _{in}*. If

*P*> 0, the block consumes active power. If

_{in}*P*< 0, the block generates active power.

_{in}### Faults

To model a fault in the Dynamic Load (Three-Phase) block, in the
**Faults** section, click the **Add fault** hyperlink in
the parameter that corresponds to the specific fault that you want to model. When the
**Create Fault** window opens, you use it to specify the fault properties.
For more information about fault modeling, see Fault Behavior Modeling and Fault Triggering.

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.

### 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

### Conserving

## Parameters

## Extended Capabilities

## Version History

**Introduced in R2019a**