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.

Does this IGBT bridge meaningless ?

Status
Not open for further replies.

Hasan2017

Member level 4
Joined
Oct 23, 2017
Messages
76
Helped
0
Reputation
0
Reaction score
0
Trophy points
6
Activity points
831
Hello My Dear Friends!

Hope this post finds you well.

I am trying to develop a AC to DC rectifier 110V/50 A range.
Feeling that I am doing wrong on making the full bridge or half bridge portion.
The IGBT module I am using is FF75R12RT4,https://www.infineon.com/dgdl/Infineon-FF75R12RT4-DS-v02_01-EN.pdf?fileId=db3a304327b89750012805fd8fd76151
IGBT.PNG

One module contains 2 IGBT that makes me confusing!
I need to understand my switching topologies first

Take a look my diagram, how the current flows back from primary winding of TR for a full cycle?

igbt_bridge.PNG

1. When point A is positive then Q2 conducts, Q1 is OFF?
2. When point A is negative then Q1 conducts Q2 is OFF?
3. When point B is positive then Q4 conducts, Q3 is OFF?
4. When point B is negative then Q3 conducts Q4 is OFF?

Freewheeling built on doides are available, whats 2uF high voltage is doing here?
 

It's a regular full bridge, sketched in a rather nondescriptive way. 2uF are DC bus bypass capacitors, strongly suggested to avoid IGBT overvoltage caused by large di/dt.

1. When point A is positive then Q2 conducts, Q1 is OFF?
2. When point A is negative then Q1 conducts Q2 is OFF?
3. When point B is positive then Q4 conducts, Q3 is OFF?
4. When point B is negative then Q3 conducts Q4 is OFF?
A is DC+, B is DC- bus node. They don't change polarity. Confusion is apparently caused by the inappropriate schematic style.
 

It's a regular full bridge, sketched in a rather nondescriptive way. 2uF are DC bus bypass capacitors, strongly suggested to avoid IGBT overvoltage caused by large di/dt.


A is DC+, B is DC- bus node. They don't change polarity. Confusion is apparently caused by the inappropriate schematic style.

Question arises if both node remains constant on polarity then why 4 igbts are used? One leg of primary TR connected with a pair of IGBT doesn't tell us that its polarity could interchange? Don't you mean the circuit is not wrong?
 

Hi,

the circuit seems to be correct.
Node A is always positive, node B is always negative.

A "full bridge" needs 4 IGBTs. It has two ouputs. The difference voltage of both these outputs may be positive or negative.

Klaus
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top