Constant Power Load
Constant power load for DC or AC supply
- Library:
Simscape / Electrical / Passive
Description
The Constant Power Load block implements a constant power load for a DC or AC supply.
If you set the Load type parameter to
DC:
The block outputs a nominal rated power as long as the voltage from the DC supply is equal to or greater than the value specified for the Minimum supply voltage parameter.
When the voltage from the DC supply drops below the Minimum supply voltage, the load behaviour changes and the block acts as a constant resistance. If the supply voltage becomes negative, the block acts as a constant reverse conductance.
To ensure smooth transitions between these behaviours, the block uses a third-order polynomial spline with continuous derivatives. You can specify the width of this transition using the Transition voltage width parameter.
If you set the Load type parameter to
AC:
The block outputs a nominal rated power as long as the voltage from the AC supply is equal to or greater than the value specified for the Minimum supply voltage (RMS) parameter.
When the voltage from the AC supply drops below the Minimum supply voltage (RMS), the load behaviour changes and the block models a load with constant impedance.
For more information about the equations for the
AC load type in a three-phase system, see the Equations
section of the Constant Power Load
(Three-Phase) block.
Faults
The Constant Power Load 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.
Variables
Use the Variables section of the block interface to set the priority and initial target values for the block variables prior to simulation. For more information, see Set Priority and Initial Target for Block Variables.