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.

How to design the controller for buck-boost converter?

Status
Not open for further replies.

powersys

Advanced Member level 1
Joined
Nov 29, 2005
Messages
440
Helped
3
Reputation
6
Reaction score
2
Trophy points
1,298
Activity points
4,987
buck boost converter design

Anyone has the note for designing the controller of buck-boost converter? Pls share. Thanks.
 

v_c

Advanced Member level 2
Joined
Oct 11, 2005
Messages
514
Helped
113
Reputation
226
Reaction score
37
Trophy points
1,308
Location
Chicago, IL, USA
Activity points
8,229

powersys

Advanced Member level 1
Joined
Nov 29, 2005
Messages
440
Helped
3
Reputation
6
Reaction score
2
Trophy points
1,298
Activity points
4,987
buck boost psim

Actually I'm referring to the 'controller', i.e. output voltage feedback to an error amplifier, which produces a voltage reference to a comparator to produce pwm that will drive a switch. Do you have such design notes?
 

v_c

Advanced Member level 2
Joined
Oct 11, 2005
Messages
514
Helped
113
Reputation
226
Reaction score
37
Trophy points
1,308
Location
Chicago, IL, USA
Activity points
8,229
buck boost converter

Did you look into the second article? They show you the compensation network around the error amplifier. You are interested in the compensator R's and C's, right?
 

powersys

Advanced Member level 1
Joined
Nov 29, 2005
Messages
440
Helped
3
Reputation
6
Reaction score
2
Trophy points
1,298
Activity points
4,987
design a boost converter (without controller)

v_c said:
Did you look into the second article? They show you the compensation network around the error amplifier. You are interested in the compensator R's and C's, right?
Actually I built a buck-boost converter (without feedback) using PSIM. When the input voltage is changed, the duty cycle of the PWM signal (fixed frequency) needed to be adjusted to give the required output voltage. I'm thinking to build the controller so that it will adjust the duty cycle automatically depending on the input voltage and feedback voltage. I know commercial PWM controller can do the work, but I wish to try building the controller in software. May be I will look into the compensation network after I got the basic controller done first. Pls advise. Thanks.
 

v_c

Advanced Member level 2
Joined
Oct 11, 2005
Messages
514
Helped
113
Reputation
226
Reaction score
37
Trophy points
1,308
Location
Chicago, IL, USA
Activity points
8,229
pwm controller for buck boost

powersys,

I think what you need is feedforward control. The feedback control you built can stay but I think you may need to adjust the amplitude of the sawtooth waveform to make the adjustment you like. The feedforward control should not change the dynamics of the system so the loop gain stability that you have with your design will be retained.

I recently posted about this topic but I cannot search the board now since the search has been disabled due to server load. When you get a chance do a search on "feedforward" and you should be able to find it.

dcj50105 -- enjoy the papers!

Best regards,
v_c
 

Status
Not open for further replies.

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top