12 volt to 300 voltDC/DC converter

[vwdevotee]

choose which dc converter topology

I'm looking to design a high power DC/DC converter for an electric car but I can't seem to find any websites with design equations. I was told to look at full bridge converters since I want to go from 300V to 13.8V. Looking at the topology below my question becomes how do I size the inductor and capacitor? Is it just a matter of playing with SPICE or some other software, or are there published analytical relationships? Also, and here's the really newb question, what's the "firing" order of the FETs labeled 1-4? I assume they all have the same PWM duty cycle. I'm planning on using a PIC controller for the PWM.

 

[mostafa ahmed]

dc-dc converter using pic

I want to ask you why you choose this topology you can choose topology easier than this topology like buck converter. you can find the complete design of buck converter in Fundamentals of Power Electronics.
good luck.

 

[vwdevotee]

bloks schema dc-dc converter

I was told that because of the large voltage difference having something like a 5 percent duty cycke was considered bad form. Plus the buck converter doesn't provide any isolation.

 

[smd_lover]

low voltage dc dc converter schematic

But you don't need to use a 5% dutycycle, since you are using a transformer that can lower the voltage..

You can look at the schematic for example a standard power supply like in a personal computer.
It first makes a dc voltage of about 320 Volts from the AC mains input, and then the 12V is made using a HF transformer with center tap and 2 mosfets.

 

[amriths04]

what power converter do i use for ukraine

I was told that because of the large voltage difference having something like a 5 percent duty cycke was considered bad form.

that's very true. as the rise and fall times of transistors themselves could be more than the duty cycle period. A smarter way is to first down convert to an intermediate voltage and then down convert to the desired lowest voltage.

Plus the buck converter doesn't provide any isolation.

Not true. You can use forward converters. Refer 'Fundamentals of power electronics' by Robert erickson.

 

[walkura]

dc to dc conv vadodara

Before you can decide on topology ,you have to know what will be your minimum and maximum load .
Do you need isolation ?
For the equations you can have a look at the books of Pressman or Chryssis.
(High-Frequency Switching Power Supplies by George C. Chryssis & Switching Power Supply Design by Abraham I. Pressman)
Either of those books can provide you with all the theory and equations you need for switchmode supply's.
If its your first switchmode ,start from a safe (low) voltage so that you get to know the workings and that you are sure you calculated right before you try at high voltage .
The size of your output filter are depending on the load and to complete this evil triangle your compensation in the feedback depends partly on the output LC.
(i know its a electronic catch 22 ,thats deserves a label - made in hell)
When regulation doesnt have to be so tight you can discard the feedback ,but still you will have to have the rest right .
Read your way in to it and for starters ,don't try to reinvent the wheel by programming your own but just get a normal of the shelf pwm generator .

Goodluck and be carefull .

 

[vwdevotee]

dc/dc isolated computer

Thanks for the tips and the books. I was only planning on using a PIC because I'll already have one on the board, so I was trying to get around having another piece. Isolation is an important thing for my project, 300V across a low voltage system wouldn't be so much fun.

 

[vatsalcena_shukla]

dcdc converter

I'm looking to design a high power DC/DC converter for an electric car but I can't seem to find any websites with design equations. I was told to look at full bridge converters since I want to go from 300V to 13.8V. Looking at the topology below my question becomes how do I size the inductor and capacitor? Is it just a matter of playing with SPICE or some other software, or are there published analytical relationships? Also, and here's the really newb question, what's the "firing" order of the FETs labeled 1-4? I assume they all have the same PWM duty cycle. I'm planning on using a PIC controller for the PWM.

 

[Dmitron]

dc/dc converter schematic

1) wich power would you need?
2) It must be a regenerative power supply?
3) can you set acid batteries in series?

 

[vwdevotee]

block schematic to 230 volt dc converter

Hi Dmitron, it's like I said. I need 100A at 13.8V output. It does not need to be regenerative. I was going to get the high voltage using a string of batteries in series.

 

[sam185]

dc/dc convertor schematic high voltage

i want a block schematic of 12 to 230 Volt dc converter with specification.

 

[Dmitron]

dc to dc converter 300v

I would advise you another schematic. In Primary - brige, 2 transistors and 2 diodes, on the secondary - the same schematic. I don't now how it calls.

// Dmitron1036

 

[Tahmid]

dc to dc high power converter design, book

Hi vwdevotee,
You have chosen the most difficult topology, which requires some theoretical and practical experience. It is difficult, because it requires to create and use isolated high side power supplies for creating virtual ground etc. It is difficult to let you know all the tidbits of full bridge circuit in nutshell- requires real some studies and knowledge. Thanks.

 

[mbruck]

dc to dc inverter power equations

you can find the complete design of buck converter in Fundamentals of Power Electronics.

Is this site or book ?

 

[willi65]

Re: DC/DC converter

hi

i think u need full bridge.. 100A not litle current..and u not need an storage choke..(calculate onle the los in the choke .if u use an step down!!!
why u want use an PIC microcontroller??? TI have many PWMs...if u want using an uC u need an dsPIC...only the currentlimit must be faster that 300ns..if not ur outputstage blow up,when output shorted..

Willi