- The phase crossover frequency, wpc , is the frequency where phase shift is equal to -180o.
- The gain crossover frequency, wgc, is the frequency where the amplittude ratio is 1, or when log modulus is equal to 0.
Example 1: Given the following Bode plots,
Example 2: Given the following Bode plots,
The phase crossover frequency is at 1.43 rad/sec, while the gain crossover frequency is at 1.06 rad/sec. The system is closed loop stable with the following stability margins:
PM= 180o + (-142o) = 38o
20 log(1/GM) = -17 or GM = 10(17/20) = 7.08
The Nyquist plot is shown below:
This page is maintained by Tomas B. Co (firstname.lastname@example.org).
Last revised 2/13/2000.
Tomas B. Co
Department of Chemical Engineering
Michigan Technological University
1400 Townsend Avenue
Houghton, MI 49931-1295
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