Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

what are the value I should put in PID controller of simulink and PLECS?

Status
Not open for further replies.

tarikelec

Member level 2
Joined
Nov 22, 2017
Messages
48
Helped
0
Reputation
0
Reaction score
0
Trophy points
6
Activity points
524
Hello everyone,

As I am trying to control a DC/DC converter, I am bit confused about the parameters of the PID. so I will ask these stupid questions.
1-in simulink, I find the the variable to fill in the PID(z) Controller as P. I , and D. here I am bit confused ,should I write Ku(ultimae gain) in the box P, Ti in box I and Td in box D or Kp, Ki and Kd.
2-in PLECS, trhe same problem arised as in the PI COntroller I found in one of their demos,Ki and Kp, what are these value representing? is it Kp and Ki(Ki=kp/Ti) or just Ti?

thnak you so much for clarifying me#
cheers
 

2-in PLECS, trhe same problem arised as in the PI COntroller I found in one of their demos,Ki and Kp, what are these value representing? is it Kp and Ki(Ki=kp/Ti) or just Ti?
I am not aware of any PID controller block in PLECS, can you share how/where did you find it ?

1-in simulink, I find the the variable to fill in the PID(z) Controller as P. I , and D. here I am bit confused ,should I write Ku(ultimae gain) in the box P, Ti in box I and Td in box D or Kp, Ki and Kd.
When you open the PID(z) block you can see how it is implemented. You need to insert the latter option you mentioned.
 


I'm not familiar with PLECS specifically but in my experience although the term "PID" is widely used there is nothing close to a standard implementation of "PID" or its coefficients (there are many ways to arrange the PID blocks, scale the coefficients, etc).

So the right approach is to decide what you want the PID to do in terms of its frequency response. Then use the AC/frequency domain simulation (which PLECS appears to have) to verify that your specific PID implementation and coefficients are doing that. Don't just trust the documentation and a stable closed loop also doesn't guarantee its doing what you want.


As another aside while P, I and D blocks can be combined to meet almost any control requirement (and discrete PID blocks are currently my preferred digital control solution versus, say, biquad IIRs) I'm aware of no systems where a single P, I and D (two zeros and one pole) is an ideal compensation solution. So its perplexing to me that PID is presented as such a common and general control scheme.
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top