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Will AC power distribution become obsolete?

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Connecteur:
Edison lost the war of the currents to Westinghouse and Tesla because his DC current couldn't be transformed to the higher voltages required for long range transmission. Alternating current, however is more difficult to use, once it gets to it's destination. A single-phase AC motor was a difficult engineering problem, and to this day is less efficient than either DC or 3-phase AC.

But DC power can now be transformed to higher or lower voltages without transformers. Solid state converters have become ubiquitous and relatively cheap. For example, fast-charging in your smartphone is accomplished by raising the voltage in the cable, allowing more power to be transferred without exceeding the current capacity of those small wires. Once the power is in your phone, the voltage is reduced to a level compatible with the battery and the phone.

About a mile from here there is a DC transmission line, running at 500,000 volts. The higher the voltage, the lower the amperage, which reduces power loss through heat. This used to be accomplished by using transformers which required AC, and significant power losses were always a factor. Now with high voltage DC, this is much less of a problem. Not only is only 1 conductor required instead of 3, it's also easier to convert power than with the old, bulky and inefficient transformers.

So why do we need AC in our homes? We don't. A house could be supplied with DC power from the mains, and converted to any type of power we could require. Imagine a future where DC power receptacles are installed in a house, at a safe voltage, where electrocution is impossible, and converters simply transform the safe current into anything that is required. Synchronization between solar power and grid power will be much simpler than it is now. It takes some sophisticated equipment to synchronize AC circuits together. With DC, it's a much simpler matter.

I likely won't live to see it, but I foresee a world of ubiquitous, safe, DC power in the future.

shapirus:

--- Quote from: Connecteur on June 12, 2024, 01:29:36 pm ---inefficient transformers.

--- End quote ---
This one has to be proved.

From what I was able to find by doing a brief search, typical efficiency of an AC transformer is well over 95%. This is a level that few DC-DC converters can reach, and only when the load matches the operating conditions they were optimized for.

Feasibility of high-voltage switch mode DC-DC converters is another intersting topic. You mentioned a 500 kV DC line, which implies that it should be possible, yet it sounds like a much more challenging task than a good old buzzing bulky AC transformer.

Connecteur:

--- Quote from: shapirus on June 12, 2024, 01:34:29 pm ---
--- Quote from: Connecteur on June 12, 2024, 01:29:36 pm ---inefficient transformers.

--- End quote ---
This one has to be proved.

From what I was able to find by doing a brief search, typical efficiency of an AC transformer is well over 95%. This is a level that few DC-DC converters can reach, and only when the load matches the operating conditions they were optimized for.

Feasibility of high-voltage switch mode DC-DC converters is another intersting topic. You mentioned a 500 kV DC line, which implies that it should be possible, yet it sounds like a much more challenging task than a good old buzzing bulky AC transformer.

--- End quote ---

I tend to think that if transformers were more efficient than DC converters, the power companies wouldn't be building so many DC transmission lines.

madires:
No, the reason is the transmission line. Please see https://en.wikipedia.org/wiki/Electric_power_transmission#Losses.

2N3055:
Nobody mentioned billions of existing electrical devices that cannot function without AC current....

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