TableCurrent

Current source by linear interpolation in a table

    TableCurrent

Library

Modelica/Electrical/Analog/Sources

Description

This current source uses the corresponding signal source of the Modelica.Blocks.Sources package. Furthermore, an offset parameter is introduced, which is added to the value calculated by the blocks source. The startTime parameter allows to shift the blocks source behavior on the time axis.


This block generates a current source by linear interpolation in a table. The time points and current values are stored in a matrix table[i,j], where the first column table[:,1] contains the time points and the second column contains the current to be interpolated. The table interpolation has the following properties:

  • The time points need to be monotonically increasing.
  • Discontinuities are allowed, by providing the same time point twice in the table.
  • Values outside of the table range, are computed by extrapolation through the last or first two points of the table.
  • If the table has only one row, no interpolation is performed and the current value is just returned independently of the actual time instant, i.e., this is a constant current source.
  • Via parameters startTime and offset the curve defined by the table can be shifted both in time and in the current.
  • The table is implemented in a numerically sound way by generating time events at interval boundaries. This generates continuously differentiable values for the integrator.

Example:

   table = [0  0
            1  0
            1  1
            2  4
            3  9
            4 16]
If, e.g., time = 1.0, the current i =  0.0 (before event), 1.0 (after event)
    e.g., time = 1.5, the current i =  2.5,
    e.g., time = 2.0, the current i =  4.0,
    e.g., time = 5.0, the current i = 23.0 (i.e., extrapolation). 


Furthermore, an offset parameter is introduced, which is added to the value calculated by the blocks source. The startTime parameter allows to shift the blocks source behavior on the time axis.

Parameters

TableCurrent_0

NameLabelDescriptionData TypeValid Values

mo_table

table

Table matrix (time = first column, current = second column)

Matrix

mo_offset

offset

Current offset

Scalar

mo_startTime

startTime

Time offset

Scalar

TableCurrent_1

NameLabelDescriptionData TypeValid Values

mo_v

v

v

Structure

mo_v/fixed

fixed

Cell of scalars

true
false

mo_v/start

start

Cell of scalars

mo_i

i

i

Structure

mo_i/fixed

fixed

Cell of scalars

true
false

mo_i/start

start

Cell of scalars

Ports

NameTypeDescriptionIO TypeNumber

p

implicit

Positive electrical pin

input

1

n

implicit

Negative electrical pin

output

1