# E/M converter of speed governor

1. May 4, 2014

### latsany

I can't model in algorithm the connection between servo valve and LVDT the feed back position in application please, help me how I do

2. May 5, 2014

### Baluncore

Is it a hydraulic servo valve controlled by hydraulic pressure or is it a hydraulic servo valve controlled by electric current?
Does the LVDT measure the position of the spool in the servo valve?
What is the application?
What software are you using to model or control the system?

3. May 5, 2014

### latsany

In fact I really need to understand about both control because the system I have researched, the information it is taken from two different systems so, it's helpful if you give an advice for both systems.
Yes, the LVDT measure the position of the spool in the servo valve, in the purpose I need the LVDT for feedback that the spool of servo valve is opened_closed or not
I'm using matlab to model the system

4. May 6, 2014

### Baluncore

The important state variable is the position of the spool in the servo valve.

The spool position will be decided by the balance of two forces. Three possible examples are:
1. Differential hydraulic pressure.
2. Hydraulic pressure against a return spring.
3. Electric current against a return spring.
You must derive an equation that gives spool position from the balance of input force variables.
That information should be in the servo manufacturers data sheet.

Given the spool position you can compute the expected LVDT output signal.
The LVDT position is converted to a voltage or a current signal.
The LVDT manufacturers data sheet will give the relationship between position and output.

5. May 6, 2014

### latsany

So, where can find these information and how I model it in algorithm and in matlab

6. May 6, 2014

### Baluncore

You must identify an LVDT part number and manufacturers name.
You must identify a servo valve part number and manufacturers name.
Then get the manufacturers data sheets for detailed information.
You should be able to get the relationship equations from the data sheets.

If you do not understand the data then post the part number and manufacturers name.

7. May 6, 2014

### latsany

The research it is my final year project that I got an information as a block diagram of speed governor control system from a hydro power plant but it there is no the details about all blocks so, all are just supposed to simplify block or simply transfer function to assume behaviour of the system thus about the data of each block or device it is loaded from internet only, in addition I don't understand well about the physical functions of each block the result I am not sure about what I have modelled especially the relationship between the system such as input and output however, I am trying to and will post some data that concern to but it's better if I can send you by an email or whether it uncomfortable way by this forum it's ok

8. May 6, 2014

### latsany

Sorry, I'm a new user about the app so, how I post the file

9. May 6, 2014