Hybrid AC/DC distribution system with a shared neutral (2020)

So we're saving on the wire only. I would probably pay for extra wire just to make the system simpler, unless I was a builder aiming to save on costs.

Not sure sharing the neutral buys much as conductor size needs to go up vs just running separate wire.<p>Most hybrid inverters now days are high frequency and have a HVDC bus sitting between battery DC&#x2F;DC, solar MPPT and AC inverter&#x2F;converter. Since solar comes down from roof with HVDC it can be inverted without a transformer to AC then the LV battery uses a physically smaller HF transformer on the buck&#x2F;boost to that bus.<p>Seems to be lots of talk to tap that HVDC bus for say EV charging as its around 400v, also some inverters moving to HVDC batteries as well simplifying the DC&#x2F;DC even more so.<p>Could see a future where houses have a HVDC panel with battery, solar, inverter and EV charger hanging off it, perhaps even HVDC from pole with solid state transformers. If&#x2F;when EV become popular then you will have much more readily available&#x2F;cheap HVDC switching gear at 400&#x2F;800v. Hard to beat the simplicity and reliability of AC using transformers though for distribution.

Really not sure what&#x2F;who this is for. There aren&#x27;t many 3-phase LV AC + DC use cases apart from industrial load + control. I can&#x27;t imaging the DC part can be transmitted at a voltage that will make the system efficient while avoiding an expensive step-down conveter.

Amusingly, the first thing I thought of was &quot;phantom power&quot; for microphones, where a power supply for the microphone is carried along the same pair that returns the audio signal.

Cute. This is one of those websites that disables selecting text.<p>They explain that the DC injection must be scaled down to keep current through the neutral conductor at safe levels when the AC is under load.<p>That&#x27;s worse than useless. Nobody wants their lights to dim when they plug in a toaster. Most people would rightly assume that&#x27;s a dangerous overload condition and their wiring is faulty.<p><i>All</i> DC loads must be capable of actively responding to DC brownouts without spiraling the system to collapse. That means every single item on your DC bus needs complex electronics and software. Every lightbulb every phone charger, every widget must be able to safely handle unpredictably variable levels od DC power <i>and</i> all loads need to agree on what they&#x27;re doing so that no one device sees the voltage creep up and suddenly draw more power than is available.<p>I don&#x27;t think this concept is at all feasible.

I don’t see a world where this is possibly cheaper than just putting a AC-DC supply at the point of load. Looks like a big safety hazard too.<p>IDK, but I wouldn’t even want to debug circuits for this thing.

This is nuts. Why make such a complicated system with another fault point?