Building a supply to regulate between 400A-100A

[Braeden Hamson]

I've got a bit of a bear of a problem to tackle. I need to determine the rating of in house fuses for my student racing team. This is an overcurrent protection fuse for a 21700 cell. The issue is that a the 21700 we're using can handle 45A and not really mind. This means the fuse for overcurrent protection needs to be very significant. I need to determine the opening times of this fuse from 1/10th of a second out to about a minute and lots of different times in between those two points. So this will probably be upwards of 400A and at least 100A for a minute. Serious currents across what is basically a dead short.

We are an EV team, so I'm no stranger to high voltage and high currents. Getting 400A is simple enough, with enough hobby lipo batteries in parallel you can achieve this. However, regulating this current is the issue for me now.

In the past I've used resistors to do this, is there perhaps a more elegant way? The resistors didn't give me very good control over the currents which would be desirable.

Does anyone have any ideas for a method to do this that gives me perhaps 10A-30A resolution?

 

[danadak]

One approach :

100A Constant Current Supply for Low Resistance Load

I have a 11.1V LiPo battery that can supply 100A. It's being used for a coil gun like in this image from electroboom. (The difference being he uses a power supply with built-in current limiting,

electronics.stackexchange.com

This basic circuit could be adapted using .Kelvin sensing o.pf a shunt to regulate base drive
of transistor array.

100 amp Variable Voltage Power Supply Circuit | Homemade Circuit Projects

The post describes a simple but extremely versatile 100 amp, variable voltage power supply circuit using just a few BJTs in parallel and in a common collector mode. The idea […]

www.homemade-circuits.com

Some ideas here :

https://www.edn.com/design-a-100a-active-load-to-test-power-supplies/

Use high power IGBT in control loop[ :

https://toshiba.semicon-storage.com/info/application_note_en_20181017_AKX00055.pdf?did=63557

Or use IEGT :

Transistors | Products | Toshiba Electronic Devices & Storage Corporation | Europe(EMEA)

toshiba.semicon-storage.com

ST750GXH24 | IEGT (PPI) | Toshiba Electronic Devices & Storage Corporation | Europe(EMEA)

toshiba.semicon-storage.com

Or high power MOSFET :

https://www.littelfuse.com/~/media/..._power_semiconductors_product_catalog.pdf.pdf

As you know this is very challenging design area. I am not a designer in this area, but called on a Plasma
and welding design company, got an appreciation of talented experienced senior designers in this area.
We were supply high power MOSFETs and IGBTs to them. Design challenges, gate driving, control loops......
very challenging.


Regards, Dana.