Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronic 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.

Register Log in

How to design control feedback loop to control duty cycle of AC to DC Converter?

Bindu boora

Newbie level 6
Joined
Jul 31, 2020
Messages
11
Helped
0
Reputation
0
Reaction score
0
Trophy points
1
Activity points
83
How to design control loop for duty cycle.I have gone through few papers .There was a gain Gvd which is transfer function Vout/duty cycle.How to derive this gain value?My circuit consists of AC supply of 110 to 120 V 400hz given to a transformer which give 5V and 4 mosfets connected to LCL filter? I need to regulate output voltage to 5V and output ac ripple should be 5mV and load regulation is 0.05%.Im not understanding how to design control loop.Can I get a clear steps to do it.I have gone through few papers containg error amplifier connected to lead lag compensator then to comparator for PWM to a mosfet drive and the connected to mosfet.How to design the compensator?I needs bode plot but I need Gvd value and everywhere I can find the gain value for LC filter but my filter is LCL.
Please help me
 

Attachments

Last edited:

FvM

Super Moderator
Staff member
Joined
Jan 22, 2008
Messages
47,440
Helped
14,034
Reputation
28,321
Reaction score
12,684
Trophy points
1,393
Location
Bochum, Germany
Activity points
275,931
The intended operation isn't quite clear. The shown circuit isn't well suited to perform PWM. It can be operated as synchronous rectifier. To work as PWM boost converter or PFC converter, it must be supplemented with an input inductor and a filter capacitor blocking high frequent current.
--- Updated ---

A single phase 400 Hz rectifier will generate 800 Hz ripple in any case. To reduce the ripple, you need to place a DC/DC buck or boost converter after the rectifier filter capacitor. The most simple topology would be transformer, bridge rectifier, filter capacitor, buck converter.
 
Last edited:

Bindu boora

Newbie level 6
Joined
Jul 31, 2020
Messages
11
Helped
0
Reputation
0
Reaction score
0
Trophy points
1
Activity points
83
Is it not possible to build an ac to dc converter with which has a feedback which can control duty cycle in order to get required 5v regulated output voltage?using PI controller?
 

BradtheRad

Super Moderator
Staff member
Joined
Apr 1, 2011
Messages
13,632
Helped
2,698
Reputation
5,392
Reaction score
2,616
Trophy points
1,393
Location
Minneapolis, Minnesota, USA
Activity points
101,810
Is it possible to design a single phase buck rectifier which has a regulated output?
Yes, however... You state your transformer is 5V, therefore it implies peak waveforms of 6 or 7 volts. A simple voltage regulator (shunt or series, whichever suits) might be sufficient. It may be difficult to achieve your desired spec for ripple and regulation, depending on how heavy your load is, and how suddenly it changes.
 

Toggle Sidebar

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top