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One wonders how long these will last give their lightweight construction. There are videos on YouTube of century-old motors still operating like new, and of course they can be relatively easily rewound and rebuilt for another century of service. They appear overbuilt compared to ones of similar power today, but that makes them very robust to short-term overloads.

The VFD also monitors performance, and the results can be reported via the cloud, if the user wishes. The motor’s software can also be updated in this fashion. Such remote monitoring offers a variety of ways to conserve energy, manage performance, and predict when maintenance may be needed.

More points of failure, more opportunities for attack, and more ways to enforce planned obolescence? I'm a software developer, and yet I don't think putting more software in everything is a good thing.

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With this motor rewinding is even simpler. Just swap the PCB (which contains no electronic, only windings), the rest of the motor can remain in place. PCB manufacture is cheap and extremely efficient, far cheaper and more efficient than manual motor winding.

> makes them very robust to short-term overloads

There’s no reason to believe that these motors will be any less robust. Older motors are robust to overload by virtue of have lots of copper which take a while to heat up, but they have no real ability to detect that overload and prevent the heating effect in the first place. These motors require VFDs to run them, VFDs are perfectly capable of current limiting the power supplied to the coils, to ensure they can never hit a dangerous temperature, thus making them immune to damage caused by overload (they would just shutdown once and freewheel).

> More points of failure, more opportunities for attack, and more ways to enforce planned obolescence? I'm a software developer, and yet I don't think putting more software in everything is a good thing.

Basically every industrial motor that’s been installed in the last 30years (probably more) is powered by a digital VFD running clever software. The efficiency and control gains provided by AC motors powered by VFDs are unreal. No “traditional” motor can even get close. VFD powered AC motors are more energy efficient, more robust, have precise speed control, any zero consumable parts (bearing might be consumables is certain situations).

Unlike older DC motors that have things like carbon brushes that need to be replaced, have speed control achieved by ginormous variostats. Older AC motors are almost useless for anything except specific industrial applications, because you have no speed control, it’s dictated by the grid frequency. VFDs have changed all of this, and made it possible to create motors the size of watermelon that can produce over 300hp.

As for the cloud bit, industry likes the idea of equipment that can monitor itself. A network connected VFD can report all manner of interesting data that can help with health and maintenance monitoring, along with intelligent remote diagnostics. Potential allowing people to accurately predict failure not just in the motor, but also in whatever mechanical equipment it’s powering. Ignoring the security aspect for a moment, that an incredible capability to have built directly into your motors.

I would assume that they actually mean that the VFD communicates over I2C, Modbus, or some similar protocol, and that it could be interfaced with a SCADA system if desired.

Integrating a VFD with a motor makes a lot of sense. The VFD can be designed with the motor and can understand the motor’s characteristics. Also, the leads between the VFD and motor can emit quite a lot of EMI, and keeping them short is valuable.

(I’m not actually an expert on this, but I did recently evaluate an integrated motor-and-drive versus a separate motor and drive for a smallish application, and the integrated system was a clear win. It’s still embarrassingly low efficiency — there’s a tendency for industrial motors below several HP to be poor to mediocre. Nonetheless, the integrated system was superior. And no, it does not have an Internet connection.)

I'm not sure what the value is of a hunk of steel that can last forever, if it's wasting power that whole time, and needs to be rebuilt periodically anyway. In the end, all you save is not having to manufacture a couple of castings and a shaft again. Those aren't especially expensive materials or processes. And a lightweight motor is especially valuable in anything that moves.

This is precisely why most people abandoned old appliances, even if they “last forever”. Often the energy efficiency of newer devices is well worth the reduced lifespan.

Also, survivorship bias. Not every electric motor made a century ago survived until today; we just see the really well made ones that did.

Really well made or really well designed? Even a century ago, there wouldn't be that much variation between one motor and the next on a given production line.

Made, not designed. Mass production a century ago was a fundamentally manual process, and therefore would show much more variation per item than modern processes.

The only argument for it being designed for durability is that the designers assumed poor tolerances in the manufacturing process, and therefore designed with that in mind.

That variation would account for some premature failures, not a few motors randomly lasting 100 years by exceptional luck and skill. 100 years is just the performance you get when the thing is assembled correctly.

The variation would occur on both sides of the bell curve. A few motors will die prematurely, and a few will last forever. The classical bathtub curve of failures will skew the bulk of the failures out past a decade or so, but on the order of a century only the lucky few exceptionally-built, or exceptionally-maintained devices will last.

  > The only argument for it being designed for durability is that the designers
  > assumed poor tolerances in the manufacturing process, and therefore designed with that in mind.

Another issue was uncertainty. A century ago we did not have such precise ideas of metal fatigue and other material failures as we have today. Witness the DeHavilland Comet for and extreme but well-known example. Today, the oft-maligned term "designed to fail" actually means that all parts of a device can fail at once, instead of over-building some parts at the expense of cost, weight, and efficiency.

I don't think that rebuild would happen more frequently with PCB based windings though, the main failure mode of stators from insulated copper wire is that over time the vibration eats through the lacquer, especially near the places where the wire has been bent sharply, which then shorts out the stator. But if your whole winding is fixed in place in the PCB with space enough to prevent arcing then I don't see how short of gross mechanical damage or frying a winding you'd ever have to replace them.

Most of the motor drives running in industrial settings are so complex they at generally setup by the manufacturer (onsite or in the field) and not the OEM or customer.

My company specifically brings in a contractor (from the maker) to commission system parameters since they literally have 1000s within the drives.

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