> >The system incorporates a purely electronic transmission
> A what? Not possible: a transmission is a mechanical item that converts rotary motion into rotary motion at a different speed and torque level
Other articles about this company explain what this electronic "transmission" is: variable windings. So they can switch from 6 phase to 4 to 3, which will change the RPM per volt. I think.
"The linkage to change the pitch of this rotating blade is way too complex! Can we simplify it somehow?"
"How about we just add a simple device that associates the pitch of the blade with the torque, and let a computer figure out how to spin the motor to get the pitch we want? No linkage!"
Back in highschool shop class I was tasked with building a three phase motor demonstration. The idea was to visually demonstrate the rotating field of the the three phases in the motor windings for open house. I took an old 1 horsepower (0.75kW) motor, pulled the rotor, and sat a few large-ish ball bearings in the stator housing. When plugged in to three phase the bearings rapidly spin around the inside of the stator housing.
I had to do a few more mods such as clear plexi end covers as well as add resistors in line with each phase to drop the current. Without the rotor the inductance is much lower pulling way more current than the nameplate rating (otherwise magic smoke). Then wired it to a contactor and button to run it.
> In recent years, motors have started to be designed for the non sinusoidal waveforms that come out of chopper power supplies.
From what i remember, square waves are better for a motor.
Thinking about it i see no benefit of it being sine (*with many poles, that is, as a square would shake the mechanical parts too much otherwise).
> Turntide’s patented Smart Motor System is built around a type of electric motor known as a switched reluctance motor, or SRM. ... There’s only one moving part: a solid steel rotor that turns in a switchable magnetic field.
sounds interesting, then this:
> Turntide’s cloud-based software platform makes SRMs more controllable and allows them to run at much greater efficiency than legacy motors.
> Torque control is more complex than just simply running 3ph AC motor off DC.
Fair enough, I got a bit too greedy with my wants.
Right now, I'm interested in running 3ph AC motor (or brushless DC motors) off DC using STM32 but having a hard time finding good open designs with affordable (DIY) feedback systems.
I'm still a bit confused with the article. It does mention that they are not using wastegates.
Excerpt:
Instead of a waste-gate, the motor will convert that excess energy into electricity by preventing the turbo from over-speeding.
I reason that they are using resistance on the electric motor to reduce the speed of the turbine. It makes more sense now. They can control the electric motor better than any wastegate by means of a computer. The resistance can then be immediately removed and boost would become available instantly because it would be spinning near the full-boost RPM (or island, as it is commonly called in the performance industry).
> The idea of one spinning even at 20 or 30 RPM was a scary demonstration of potential energy.
Grid FES rotate at above 10k RPM. Munich has a control & stabilisation FES whose flywheels max out at 45000 RPM. Though they're probably not 60 feet wide the 28 flywheels store up to 100kWh.
Question: I recently got an “inverter” based A/C and I see it has very smooth start up. Is that basically what I would call a brushless motor? Maybe the term inverter is being used because the original source is A/C?
My understanding is that the author is not a technologist and that these aren't literal physical descriptions of what happened with the turbines. The simplest generators maintain a steady angular velocity that (when normalized for the number of poles) corresponds to the frequency of the output signal.
To give the benefit of the doubt to the author, it is also true that a turbine shaft can be connected to a generator via a gearbox, in which configuration a faster turbine would correspond to more power delivered to the generator at the same generator RPM.
> electric motors are better for that usage, since that is what they use
Except those that actually use hydraulic couplings or torque converters, which is the cheaper and lighter solution compared to electric, albeit less efficient.
>It seems like the big innovation here is that it doesn't use slip rings and brushes anymore, and the power to the rotor is now transferred via induction coils
So like AC induction motors we've been using in various machinery for over a century? (see squirrel cage motor for example).
Here where almost everyone has 3 phase power such motors are extremely popular. Any device more powerful than 1kW will very likely feature such "brushless" motors. The oldest I own is a 7kW milling machine made in 1960s.
> That looks like a linear motor, which unless I'm missing something is spectacularly power hungry.
They are, by themselves, not more power hungry than the corresponding type of rotary motors.
Their biggest problem regarding power usage is that they can't use gears to gain mechanical advantage. Since electric motor losses are roughly proportional to their torque (or force, in case of linear motor), it is often the case that the linear motor will require more power.
But a quick look at some of the windshield wipers mechanisms shows that rotary motors that drive them are in a mechanically pretty disadvantageous position, with a very short lever arm compared to what a linear motor would be. So it might work well in this case.
> A what? Not possible: a transmission is a mechanical item that converts rotary motion into rotary motion at a different speed and torque level
Other articles about this company explain what this electronic "transmission" is: variable windings. So they can switch from 6 phase to 4 to 3, which will change the RPM per volt. I think.
https://insideevs.com/news/364852/linear-labs-hunstable-elec...
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