MGU-K & H - AC/DC

[irsq4]

So, are they AC or DC current machines? I suppose that generated Energy is inverted in DC before stored in batteries if they`re AC machines.?

Maybe is posted somewhere before, but can`t find?

[Kiril Varbanov]

The MGU-H produces alternative current, but the battery is continuous current so a highly complex converter is in place.

[Dragonfly]

Yep. Because the frequency varies in broad margins I think there is always rectification and then a converter with frequency/phase/PWM control for accurate control of power and torque of the MGU-K.

[zenji]

The easiest way to store current is in dc form, I think.
This is usually done with 4 diodes and a capacitor to 'iron' the ripple flat.
I'm sure there are variations on the switch mode design, but that's a lot of theory i cant grasp wholly.

[Tim.Wright]

As far as I know they are a "permanent magnet brushless DC motor" If you put that into google you will get a lot of info regarding how they work.

The motor itself is basically an AC machine with magnets on the rotor and coil windings on the stator. There is then an inverter and a controller which does the conversion of DC power to AC phase signals. The inverter/controller is basically doing something similar to what a mechanical distributor did in an automotive electrical system - i.e. it connects and disconnects different phases to the power source as a function of the rotor angle. This process is called commutation. The advantage of these motors is that commutation is done using electrically controlled switches instead of mechanical switches which have moving, rubbing parts which wear at a high rate because of large inductive spikes as you do the switch.

[autogyro]

You still get the 'large inductive spikes' but instead of mechanical wear you get heat.
If you do not control things very carefully you get fire.
Which is why F1 cars these days often burst into flames unless you turn off either the MGU-K or the MGU-H.
Its even more difficult with full electric traction when you try to control things on and off load.

[gruntguru]

No more heat than a "brushed" motor, in fact less. The MGU's are well over 90% efficient.