Second Order Lag Element (PT2)¶

The PT 2 element contains two independent energy stores. The step response depends on the damping d and the resonant frequency. There are four cases:

1. Undamped: d= 0. The step response is an undamped sinusoidal signal

2. Underdamped: 0 < d < 1

3. Critically damped: d = 1

4. Overdamped: d > 1

Functions

For d <= 1 we get:

Step response

Magnitude and phase response

Polar plot