The Filter, 2nd-order component is a second-order low-pass filter that implements the following transfer function:

LaTeX Math Block

Symbol

Mask Parameters

Name	Description		Unit	Variable = {Possible Values}

Name	Description	Unit	Variable = {Possible Values}
Description	Use this field to add all kinds of information about the component		Description = {'string'}
Filter natural frequency	Second-order natural low-pass filter frequency	Hz	FreqFilter_fn = { [0, 1e12] }
Filter damping ratio	Second-order low-pass filter damping rate. The damping ratio is typically a value between 0 and 1		FreqFilter_zeta = { [0, 1] }
Initial input (DC component)	Initial value of the DC component magnitude of the output signal for the first simulation cycle. This value cannot be modified during the simulation		InitialOutput = { [0, 1e12] }

Input/Output Signals

Name	Description	Type
u	Input signal	Input
y	Filtered output signal	Output

Sensor Descriptions

Name	Description	Unit
u	Input signal	No unit
y	Filtered output signal	No unit

Internal Circuit of Component

Limitations

The Filter, 2nd-order component is designed for DC input signals. With AC input signals, the component output presents a temporary offset corrected after several time steps.

Example Model

This example demonstrates the usage of First order and Second order filter blocks. A 60Hz sinusoidal signal is given as an input to the second order low pass filter block with 60Hz natural frequency and a damping of 0.707.

Filter, 2nd-order