Why such high voltages on EV or hybrid.

[oil pan 4]

Playing with my ABB drive I noticed a familiar number. My ABB drive is a single phase 208 to 240vac input unit who's inverter has a 350dcv bus voltage when hooked up to 240vac power.
Where have we seen 350 volts before?
What are some common battery voltages used on EV and hybrids? Well 270 to 350 DC volts of course.
Common normal single phase voltage for a lower voltage non 480 volt drive is 208v and 240vac AC. Which should make between 290 and 350vdc.
It's like they just repurposed and slightly reengineered existing industrial drive designs for automotive use.

[me and my metro]

First off, why reinvent the wheel? Second, high voltage = lower amps= smaller gage wire. That is why transmission high voltage lines are 500,000 to 1 million volts. Double the voltage = twice the power = the same size wire.

[oil pan 4]

It's just a little difficult to find chargers, mod, repurpose existing EV and hybrid stuff when it all runs at such high voltage.

[Stubby79]

Originally Posted by oil pan 4

It's just a little difficult to find chargers, mod, repurpose existing EV and hybrid stuff when it all runs at such high voltage.

They weren't designed as modular with re-purposing in mind.

And it's a lot cheaper to build something to handle high voltage than it is to handle high amperage. And for the same reason, they're also more efficient. I-squared and all that.

[LittleBlackDuck]

Originally Posted by oil pan 4

Playing with my ABB drive I noticed a familiar number. My ABB drive is a single phase 208 to 240vac input unit who's inverter has a 350dcv bus voltage when hooked up to 240vac power.
Where have we seen 350 volts before?
What are some common battery voltages used on EV and hybrids? Well 270 to 350 DC volts of course.
Common normal single phase voltage for a lower voltage non 480 volt drive is 208v and 240vac AC. Which should make between 290 and 350vdc.
It's like they just repurposed and slightly reengineered existing industrial drive designs for automotive use.

Not repurposed... common sense would indicate that charging of a 350v battery at high current is much easier when the required voltage is close to the D.C. rectified value of the mains supply. Lowering cost and improving overall efficiency.

Simon

[Piotrsko]

350 volts is approxmately double 120v rms mains. You saw it (maybe) back in the vacuum tube plate voltages using a 2:1 transformer or simple voltage doublers.

[ThermionicScott]

Having dabbled with vacuum tube stuff, it's weird to discussion of 200-400V as "high voltage." It just makes sense when you're dealing with higher powers.

Our cars could be running higher voltages throughout the whole system for less loss and lower weight, but 12V was good enough, I guess.

[thingstodo]

Just my opinion ... but the design of a charger that takes 220 VAC, through a full wave bridge, and does a buck convert down to the proper voltage to charge the battery pack is simpler ... and more importantly cheaper .. than a buck/boost topology that needs an inductor for the boost.

The battery pack cost does not appear to change much whether you do 99S2P or 33S6P. You still need about the same Amp-hours to go 1 mile. The price of the contactors, fuses, insulators and IGBTs is lower for lower amps and higher voltage. I'd like to see a bit more circuitry checking for frame leaks, and more contactors isolating sections of the packs ... but perhaps I'm paranoid.

700 - 800 ish VDC for the 460/480V 3 phase input to DC bus

900 - 1000 ish VDC for the 575/600V 3 phase input to DC bus

Wolftronix (youtube handle) is working on an arbitrary (likely reasonable to boost 5x, buck 10x) DC/DC converter using a Prius inductor. I have not seen any update posts on it lately

Last I saw, he was trying to use a 48V pack to power solectria controllers (which he repairs) and perhaps fool a DC charger into thinking it was charging a 144V pack when it was connected to the converter and actually charging a 48V pack.

Interesting stuff. Even with his experience, I would expect some smoke to be released from some IGBTs ...

[oil pan 4]

If the battery resting voltage is 350, and the peak sine wave voltage on 240v AC is also 350 it's still going to need to be stepped up to charge a 350v battery.

[Erasmo]

My Zero is around 100V.