First-Order Filter
First-order filter.
Description
The First-Order Filter block implements one of the following transfer functions depending on the value of the Filter type parameter:
-
Low Pass Filter:
-
High-pass filter:
where
-
- Laplace operator;
-
- time constant.
Characteristics
The main characteristics of the First-Order Filter block are:
-
The input port accepts a vector of signals and implements filters. This feature is especially useful for controller design in three-phase ( ) systems.
-
It is possible to initialise filter states for DC and AC input setpoints.
Ports
Input
#
IN_1
—
filter input signal
scalar | vector
Details
The input signal of a first-order filter, given as a scalar or vector.
| Data types |
|
| Complex numbers support |
No |
Output
#
OUT_1
—
filter output
scalar | vector
Details
The output of a first-order filter returned as a scalar or vector.
| Data types |
|
| Complex numbers support |
No |
Parameters
Main
#
Filter type —
filter type selection
Lowpass | Highpass
Details
Determine the type of first-order filter. Set Lowpass to realise a lowpass filter, or set Highpass to realise a highpass filter.
| Values |
|
| Default value |
|
| Program usage name |
|
| Evaluatable |
Yes |
# Time constant, s — filter time constant
Details
The time constant of the first-order filter, given in seconds.
| Default value |
|
| Program usage name |
|
| Evaluatable |
Yes |
# Sample Time — sampling period
Details
Specify the sampling period of the block in seconds. Set to 0 to realise a continuous block.
| Default value |
|
| Program usage name |
|
| Evaluatable |
Yes |
# Initialize filter states: — initial value of AC and DC current
Details
If this check box is selected, the filter states are initialised according to AC initial input: [ Mag, Phase (degrees), Freq (Hz) ] and DC initial input.
| Default value |
|
| Program usage name |
|
| Evaluatable |
Yes |
# AC initial input [Magnitude, Phase (deg), Frequency (Hz)] — initial value of the variable component
Details
Specify the initial value of the variable component of the input signal: amplitude, phase in degrees and frequency in Hz. If the input signal is a vector ( signals), specify the matrix by 3, where each row of the matrix corresponds to a specific input. Phase can have any value. Amplitude and frequency must have a positive value.
Dependencies
To use this parameter, select the Initialise filter states checkbox.
| Default value |
|
| Program usage name |
|
| Evaluatable |
Yes |
# DC initial input — initial value of the constant component
Details
Specify the initial value of the constant component of the input signal. If the input signal is a vector, specify vector 1 at , where each value corresponds to a specific input.
Dependencies
To use this parameter, select the Initialise filter states check box.
| Default value |
|
| Program usage name |
|
| Evaluatable |
Yes |