Electronics > Projects, Designs, and Technical Stuff
1kW 200/400V dc/dc converter design tip
Benta:
@webgiorgio:
The coils you are linking to are common-mode noise suppression inductors and will in no way store the energy you are looking for. The current rating is for the 50 Hz going through.
The kind of coil you are looking for will be around the size of two cigarette packs. Also core and copper loss will be significant and way higher than your estimations.
That's why I suggested full bridge or forward.
webgiorgio:
--- Quote from: richard.cs on January 28, 2019, 10:44:15 am ---Another topology to consider; a half bridge driving a 1:1 isolation transformer, the output from the transformer is full wave rectified and placed in series with the input supply.
--- End quote ---
Neat!
If it is a single secondary with full bridge, the current can be is positive and negative in the winding.
If it is center taped (is actually twice longer), each half winding will conduct for half period.
So, I think the losses in the copper are the same, so, better with 2 diodes. Same amount of copper in both cases, if it is center taped the section is half and the length twice.
This would also reduce the losses, a it is dealing with half the power. In this case I need to make it Vo=Vin.
The GTi (grid Tied inverter) complies with the grid requirements, without isolation. It has a isolation fault monitoring, that would disconnect the AC in case of leak current to ground.
I can't add inverters neither change number and orientation of panels, ans I need to comply with technical regulations.
I am allowed only to add "optimizers" (dc-dc) on the DC side.
Benta:
--- Quote from: webgiorgio on January 29, 2019, 01:00:58 pm ---
Neat!
If it is a single secondary with full bridge, the current can be is positive and negative in the winding.
If it is center taped (is actually twice longer), each half winding will conduct for half period.
So, I think the losses in the copper are the same, so, better with 2 diodes. Same amount of copper in both cases, if it is center taped the section is half and the length twice.
This would also reduce the losses, a it is dealing with half the power. In this case I need to make it Vo=Vin.
--- End quote ---
No. The center tapped configuration has significantly higher copper losses, as only half of the secondary is used at a time and it only has half the winding space = double resistance.
At these voltages I see no reason to avoid a bridge rectifier, this is only relevant in low voltage applications where diode drop is an issue.
David Hess:
--- Quote from: coppercone2 on January 28, 2019, 05:15:16 pm ---Are there any available tantalum caps on the market that would make that gigantic lump of foil capacitors go away?
--- End quote ---
I do not think so but there might be such a thing for aerospace and military applications. They also make really big ceramic capacitors for aerospace and military applications but they are similarly expensive.
--- Quote ---Why are hermatic ones only built to 100v?.
--- End quote ---
The solid hermetic parts are available up to like 75 volts and the wet tantalums are available up to like 125 volts. Considering their cost, they make even expensive film capacitors the cheap option and the way to go.
Navigation
[0] Message Index
[*] Previous page
Go to full version