Unpacking the Power of the KIA EV9: Dual-Stage Motor & Inverter #kia #motor #ev9

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[BrandonMeyer]

I’m loving the innovations that are happening in the ev space. The companies taking things seriously are always coming up with cool ideas to make their product better than the competition.

[ANGRY_AMERICAN]

In heavy industry in the control cabinet we used 2 relays with a timer relay 1 was wired in Y to start the motor and get it running and when timer would switch to relay 2 that was wired in D to bring the motor up to speed. Digital motor controllers that had soft start did the same thing in a much smaller unit. Like comparing the power and size of the computer that NASA used during Apolo was several floors vs your cell phone that is 10x more powerful and fits in pocket

[noelcastle]

Star delta technology has been around for many decades used for motor starters usually and bringing six connections out to the pecker head of the motor is standard procedure on bigger 3 phase motors.

[berndgrabitz]

you hear this switch between the two configurations when you listen to the acceleration of the Metropolitan trains leaving the station

[Nashcaster]

Your close, wye is for torque but allows current bleed to the other phases. Delta doesn’t have enough current bleed to the other phases to cause high torque. 🤙 wye for pickle jars, delta for speed. Thats pretty cool what they are doing. These inverters are getting more advanced by the day 🎉

[benbohannon]

So they’re taking electric transformer designs and implementing as a sort of transmission-able electric motor… that can do best at low speed, and then “shift” to do best at high speed. Amazingly clever!

[pictsidhe]

Torque and power capability does not change. The delta-wye switching is to change the impedance. This improves inverter efficiency across the whole speed range.

[vcracing]

When you connect the motor in Wye configuration, you get the flux capacitor and are able to travel back to 1955.

[TheMisterpino]

Sorry to see the Wye config mostly used for lower speeds, I'd love to see it reach 88mph

[formytots]

Great idea. Kudos to KIA for their innovation.

[ljdkik]

The two-stage inverter also applies to high-performance electric vehicles, such as the ev6 GT and the Ioniq 5N. Simply put, it uses only one inverter to ensure efficiency when running slowly, and when the driver needs high power, the two inverters operate to reduce the burden and power consumption compared to using a single inverter

[dunckeroo]

A simple way to match voltage for frequency, maybe simplifying the front end of the inverter. Its the volts per turn that is changed, which can be increased at higher speeds.

[philip_fletcher]

This wye to delta switching has been used for decades in traditional machine motors to go from high torque startup to high speed running.

[maikrolf]

but what motor does not have this then? i never saw a motor with only 3 connections.... its always 6 with any motor

[Zedus-rlhp]

Wasn't that also the case with old machines that worked with a flywheel? They also had this Y-delta circuit, which sometimes even had to be switched manually after starting up.

[foxythedirtydog]

Nothing new here. Motors wired for star an delta have been around for decades.
Star doesn't give high torque it is used to reduce current at low speeds such as when motors are started. Star is low power low torque so good for cruising and delta for hard acceleration.
There could be a lot more going on though such as better regenerative braking at low speeds.

[makeitgreener]

Do they switch from wye to delta or back depending on speed?

[paulturner]

The whole world calls this Star/Delta. WTF?

[levo]

I've never seen it spelled out as Wye. I've seen star or just Y.

[ildarmingazov]

we call "star" and "triangle"