blockPowerLinearized

Power function that is linearized below a user-defined threshold

Extends from Modelica.Blocks.Interfaces.SISO (Single Input Single Output continuous control block).

Information

Function that approximates y=xn where 0 < n so that
  • the function is defined and monotonically increasing for all x.
  • dy/dx is bounded and continuous everywhere (for n < 1).

For x < x0, this function replaces y=xn by a linear function that is continuously differentiable everywhere.

A typical use of this function is to replace T = T4(1/4) in a radiation balance to ensure that the function is defined everywhere. This can help solving the initialization problem when a solver may be far from a solution and hence T4 < 0.

See the package Examples for the graph.

Parameters

TypeNameDefaultDescription
RealnExponent
Realx0Abscissa value below which linearization occurs

Connectors

TypeNameDefaultDescription
RealInputu (from SISO)Connector of Real input signal
RealOutputy (from SISO)Connector of Real output signal

Revisions

  • November 29, 2013, by Marcus Fuchs:
    Implementation based on Functions.powerLinearized.