bode diagram linearization failure

I have boost converter with PID controller. I need to linearization to plot bode diagram without transfer function. But everytime I try I cant determine diagram unless put an output mesasurement to output of PID. There was no data when I want to measure data from plant output.

The diagram I have attached belong to PID output not converter.

Answer 1

[Andrew Ouellette]

Hi @mehmed celebi, we will need more information to help you with this problem.

What happens when you try to linearize your boost converter? Do you receive an error? Do you receive a linearization D=0?

Can you succcessfully linearize other models? Have you tried using the linearization advisor to find problematic blocks?

Have you tried frequency response estimation?

Answer 2

[mehmed celebi]

Following these steps

put an perturbation to ref value

put an output measurement to output voltage of converter

run linear analysis

clıck estimation an input sin signal arrange the values

teka a snapshot ot the system at 0.3 sec

then click estimation again and click bode diagram and this error ocures:

In "frestimate(modelname,op,io,in)", the input signal "in" is a frest.Sinestream signal which has parameter values for "Frequency" and "SamplesPerPeriod" such that it inherently has multiple sample times. Using such an input signal requires that samples rates belonging to the Simulink signals where your linearization input and output points are located are either continuous or fixed in minor time step and the linearization I/O io(1) does not satisfy this requirement. Consider either changing the sample time of Simulink signal where io(1) is located to continuous sample time or using frest.createFixedTsSinestream utility to create a sinestream signal that has a single sample rate.

[Andrew Ouellette]

Okay, so it sounds like you are trying to do frequency response estimation rather than linearization. The error message is pointing to a mismatch between the perturbation signal you have defined and (at least one) location where you are trying to inject the signal. The sinestream perturbation signal can have a variable number of sample times. When you define such a sinestream, you need to inject the perturbation on continuous time [0 0] or fixed in minor time step [0 1] signals. Most likely, you are trying to inject the perturbation on a discrete time signal. Try creating a fixed sample time sinestream instead as the error message suggests.

[mehmed celebi]

I also tried this one

But this message appears about the signal.

and then this error occured

that the sample time of the Simulink signal where it is located is one of the following: 1. It is either continuous or fixed in minor time step. 2. Its sample rate is equal to the sample rate of the input signal "in". The linearization I/O io(1) does not satisfy this requirement. Consider either changing the sample time of Simulink signal where io(1) is located to continuous sample time or changing the sample time of input signal "in".