Following steps shows how to obtain a linear model of a nonlinear system in SIMULINK

1. Open the model.

2. Open linear analysis tool for the model (Analysis -> Control Design-> Linear Analysis

2. Define Input and output operating points (Right click -> Linear Analysis points)

3. Select the desired plot results (like Bode plot, step response)

4. Click linearize the model.

5. The linearized model is saved as a state space object (linsys1) in the workspace.

6. The transfer function can be obtained by: [b,a] = ss2tf(linsys1); Gs = tf(b,a)

I hope this helps. More information can be found at :

http://www.mathworks.in/help/slcontrol/ug/linearize-simulink-model.html

Following steps shows how to obtain a linear model of a nonlinear system in SIMULINK

1. Open the model.

2. Open linear analysis tool for the model (Analysis -> Control Design-> Linear Analysis

2. Define Input and output operating points (Right click -> Linear Analysis points)

3. Select the desired plot results (like Bode plot, step response)

4. Click linearize the model.

5. The linearized model is saved as a state space object (linsys1) in the workspace.

6. The transfer function can be obtained by: [b,a] = ss2tf(linsys1); Gs = tf(b,a)

I hope this helps. More information can be found at :

http://www.mathworks.in/help/slcontrol/ug/linearize-simulink-model.html

Thanks a lot Mohit. The information was very useful

I need to get the point How can I get a linear model of PLL from nonlinear I will be thankful