How to design the controller for buck-boost converter?

[powersys]

buck boost converter design

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

 

[v_c]

boost converter compensation

Here's a nice application note on the buck-boost topology

Understanding Buck-Boost Power Stages in Switchmode Power Supplies
**broken link removed**

There are lots of controller ICs to do the job. But for the compensation network for the buck-boost converter (which I think is your question) take a look here
**broken link removed**

I hope the information is helpful.

Best regards,
v_c

 

[powersys]

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]

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]

design a boost converter (without controller)

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]

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