it is interesting to think about human made object in terms of how much materials they use, for example big old transformer contains 2 tons of iron, new solid-state transformer with same capacity uses only 300 kg of silicon (Si), 120kg kg of plastics and 50 kg of copper.
I have a question for people more familiar with these. What exactly happens at the isolation stage. They say it includes a high frequency transformer (HFT). But its input and out put is DC. And classic transformers operate on AC. So in order to get the transformer working, one would have to chop up the incoming dc power into a square wave or a sine wave. But what transistors can you use to do this, considering you are dealing both with very high power and very high frequencies?
Packaged semiconductors are going to be more metal interconnect / plastic encapsulation / ceramic insulation than silicon by weight.
These systems will also have a significant weight fraction in magnetic materials, either ferrite ceramics or amorphous metals.
Still a huge weight savings, but the weight fractions you are giving see off and are missing some important materials.
It's scary to see protective relays for power systems with embedded web servers. "IEEE C37.118 synchrophasor measurement, DNP3 Outstation, Modbus TCP/RTU, Telnet, FTP, Simple Network Time Protocol (SNTP), built-in web server, and IEC 61850" [1]
No, I'm not joking. For these kinds of voltages, you need to use highly homogenous doped silicon, and the only way to produce it is to irradiate silicon with neutrons. It transmutes some of the silicon atoms into phosphorus: https://nrl.mit.edu/facilities/ntds/
And doping during crystal growth doesn't produce homogenous enough silicon.
Of topic - dealing with medium voltage e.g. 6kv-10kv - are there existing be-spoke solid-state solutions?
e.g. PV/battery 400V converted to 6kv without inverter/transformer
It's apparently possible for boron doping.
I think because phosphorus is bigger than silicium you'll get too many defects in the crystal, while with the smaller boron it is not an issue.
A public internet connected web server that enables remote equipment control is indeed scary.
Then people get two of them, one for each direction.[1] Can someone explain why this is supposed to be secure? It's apparently a real product.
You can stack power transistors to switch higher voltages on the primary side. On the secondary side you just need an H-bridge. Which can be made up of transistors in parallel.
We've had high power high voltage transistors for about 40 years now. A lot of this isn't technical but rather economic. As the price falls the applications where they are cheaper increases. It's notable for instance Toyota started work on their hybrid drive in the mid nineties when inverters for 10-100 HP motors became cheap enough.
It's worse:
https://arstechnica.com/security/2025/01/could-hackers-use-n...
I want to extend the benefit of the doubt and assume my own ignorance but I'm really struggling with this one.