4kw boost converter / General Science and Electronics / Forums

Forums

4hv.org :: Forums :: General Science and Electronics

« Previous topic | Next topic »

4kw boost converter

previous 1 2

Move Thread

LAN_403

Forty

Tue Apr 03 2012, 12:24AM

Registered Member #3888 Joined: Sun May 15 2011, 09:50PM
Location: Erie, PA
Posts: 649

If you go with a toroid inductor like in the design that Bwang linked to, you can find a large and very cheap one here

The core is yellow with a white stripe, so I think it is powdered iron, but I could check for you (I have one) if you're interested in using one.

I didn't know boost converters could be made with such high power levels, sounds interesting.

Ben Solon

Tue Apr 03 2012, 12:59AM

Registered Member #3900 Joined: Thu May 19 2011, 08:28PM
Location:
Posts: 600

2spoons: i would never! i actually have another thread going about a mot(hence the confusion?) but is is for a bench type power supply for powering low current low voltage stuff. like a range of 6-48v for circuit development, and a few higher voltages for minor power supply.

forty: i like that torroid, and may have to buy a few for later uses, but i am pretty sure that for this type of application i need an air gap. otherwise no emf is built, so no emf can collapse.

and for the rest, i think i have settled on using two hgtg30n60 igbts run at 15-25khz with a mid uH range inductor. based on calculations:

hgtg30n60b3d @ 150C, 60A -> turn off energy = 4.5mJ -> power dissipated @ 20khz = 90W

assuming ~20mJ @ 20khz(extremes) -> power dissipated = 400W

plus i have two igbts, and not pushing them that hard, so it should work out. so away from that concern(unless anyone has objections), and into the inductor itself.

i would like to get some two E cores, but i dont know how to calculate the max power through them. N = (VT)/(BAe) doesn't apply here i dont think. does it? steve posted that he got two 4kw cores. i didnt know cores had a kw rating. and where would you recomend getting cores like these. type "ferrite ee" on ebay. do any of those look suitable?

teravolt

Tue Apr 03 2012, 01:49AM

Registered Member #195 Joined: Fri Feb 17 2006, 08:27PM
Location: Berkeley, ca.
Posts: 1111

hi Ben. is your boost inverter going to be cw or burst. I plan to do the same thing but in a burst mode to power a qcw. I got thease cores at

they can be configured as a large E core or like I have hear you just need 8 or so. I dont know how many you will need for 4Kw with out saturating. I am using 200amp IGBT full bridge with 13000uf behind it. so far a resonant topoligy has not been sucsesful for me so I am going to try a delta modulation topoligy next, PWM, maby some one can tell us how many might be needed to pass 4Kw. I found this while poaking around I found it to be usefull.

this type of project is work and not for the faint of hart

2Spoons

Tue Apr 03 2012, 02:47AM

Registered Member #2939 Joined: Fri Jun 25 2010, 04:25AM
Location:
Posts: 615

OK, just that you mentioned MOTs in the second post in this thread.

Powdered Iron toroids are nice as they effectively have a distributed airgap - all the little gaps between the powder grains add together. Downside is its a fixed 'gap'.

I still think you'd be better off with a resonant bridge, but thats just my opinion.

teravolt

Tue Apr 03 2012, 04:04AM

Registered Member #195 Joined: Fri Feb 17 2006, 08:27PM
Location: Berkeley, ca.
Posts: 1111

I was hoping like a big ZVS but it will take a little more invesigation. ither my resonant cap is to inductive my setup is funky. i was hopping to do resonant bursts like a DRSSTC and rectifie and filter and use a bang-bang controler to controle the average power. I think that boath sides of the transformer have to have the same resonant frequency to work in this mode. Mazillii works like this. I have some big unknown cores and some all50 material from TSC int. it has stabiliy over a wide temprature and its good up to 100KHz. the QCW power supply is a cross between a power supply and amplifier so controling it will reqire some closed loop feedback.

mot cores are a bad choice because they are made from plate iron and only opperat up to 400hz. they have lots of eddt current. micro wave trani's are prity inefishent as transformers go. I set up 4 in a series parallel and wih no arc they drew 10A from the wall.

Ben Solon

Tue Apr 03 2012, 12:43PM

Registered Member #3900 Joined: Thu May 19 2011, 08:28PM
Location:
Posts: 600

Yes, looking at different smps topologies, the best one that you can use is the split-pi topology. 96% efficiency and many kw of power. Because I only really care to step it up, I can replace one set of switching devices with diodes and operate the other two. Now it resembles a double boost converter.

Ant to teravolt, I will be running the bridge of a drsstc with it, and this means Large filter caps. ~2kw continuous, and I don't think I will ever have to use more than that in anything other than a burst. The 4kw power is an overhead. And thanks for the link to those u cores! I am going to buy a few sets of them. And good luck with the qcw bus modulator, I am not going to attempt something like that for a while. All I am trying to do is maintain a constant bus voltage, not modulate it.

previous 1 2

Moderator(s): Chris Russell, Noelle, Alex, Tesladownunder, Dave Marshall, Dave Billington, Bjørn, Steve Conner, Wolfram, Kizmo, Mads Barnkob