# Dynamic Load (Three-Phase)

Balanced three-phase dynamic load

**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 next
to the fault that you want to model. In the Add Fault window, 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**