Solving state space equation using matlab function block in simulink

Hi, Im trying to model a synchronous machine. My present situation is, i know the A, B, C, D values and my input signal is coming from other blocks which are voltages, speed etc. State variable in my case is flux. I need to find this flux value so as to find derive current, torque etc. So how to solve this state space equation to get the state variable. I tried to read many examples but im not able to find the one I need. Any help is appreciable

Answer 1

[Sebastian Castro]

If you already know the A, B, C, D matrices, why not use a State-Space Simulink block, then?

- Sebastian

[leonn alexander]

But i don't know how to use that block. And one more thing i forgot to say is, i have the equation xdot= Ax + Bu only with me. Im not concerned about y. So, i can give an input which will act as "u" in the equation, but i have to get "x", the state variable, as output. So can I use y=x as the second equation which will give me C=1 and D=0 and is that the way to do it?

[Sebastian Castro]

That block takes in the A, B, C, D matrices as MATLAB matrices -- not much to it!

Also yes, if y = x, then your C and D matrices are 1 and 0 respectively, as you said. For example, if your A matrix is 4x4, your C matrix is the 4-dimension identity matrix: In MATLAB, eye(4).