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Sketch Bode plot & assess the stability for the control system having open loop transfer function G(S)H(S)=120(S+2)(S+10)
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written 8.2 years ago by |
G(S)H(S)=120(S+2)(S+10)
Arrange the above equation in time control form,
G(S)H(S)=120(2(1+0.5S) 10(1+0.1S))
G(S)H(S)=6(1+(S2)(1+S10)
Comparing with standard form of time constant,
K=6
Mo pole at origin.
Simple pole at 1(1+(S+2), wc1=2 rad/sec
Simple pole at 1(1+(S+10), wc2=10 rad/sec
Magnitude plot:
For k=6, 20log6=15.563 dB
Phase angle plot:
G(jw)H(jw)=6/(1+j(w/2)(1+j(w/10)
=<6+j0)<1+j(w/2)(<1+j(w/10)
The table for phase angle will be:
From Bode plot as shown in the figure:
GM=∞; PM=58
Hence the system is stable.