Bit of electronics for a change, circuits, chips! yummy jummy!...

On Sunday, 4 September 2022 at 07:32:10 UTC-7, jla...@highlandsniptechnology.com wrote:
....
High voltage needs thick insulation on the wire, and skinny wire
windings lose window area to insulation more than fat wires. And
insulation doesn\'t conduct heat as well as copper. Triple whammy.
Click to expand...

I agree for low power motors with small gauge wire this means it is a disadvantage to go to higher voltages.

However for the traction motors where the wire has to be able to handle hundreds of amps it is of such a large cross-section that the insulation area occupied is much less of an issue.

kw
 
...
With modern EVs the active devices IIGBT typically) in the motor driver were first available with breakdown voltages of the order of 1000V and so were only good for system voltage about half of that - 400V tended to be used.
I didn\'t read this carefully. But why half system voltage?
With SIC that has increased so 800V (that can go up to ~950V when fully charged) are practical.
If that\'s the case, we should go with 1200V. These IGBTs are amazing with 1200V 40A 500W (huge heat sink) in TO-257.

https://www.infineon.com/cms/en/product/power/igbt/igbt-discretes/ikq40n120ch3/
1600V 30A IGBT:
https://www.infineon.com/cms/en/product/power/igbt/igbt-discretes/ihw30n160r5/
Click to expand...

There needs to be some voltage margin and the highest voltage rating device will be more expensive than mid-range ones from the same family, there may be tradeoffs in other parameters such as ON resistance and speed. A 400V system may be close to 500V when the battery is fully charged.

Also don\'t forget that the 400V decision was made something like 15-20 years ago - the devices were not so capable.

These days the trend is to use silicon carbide FETs rather than IGBT devices as the latter is very limited in switching speed.

kw
 
On Sunday, September 4, 2022 at 2:46:22 PM UTC-7, ke...@kjwdesigns.com wrote:
..
With modern EVs the active devices IIGBT typically) in the motor driver were first available with breakdown voltages of the order of 1000V and so were only good for system voltage about half of that - 400V tended to be used.
I didn\'t read this carefully. But why half system voltage?
With SIC that has increased so 800V (that can go up to ~950V when fully charged) are practical.
If that\'s the case, we should go with 1200V. These IGBTs are amazing with 1200V 40A 500W (huge heat sink) in TO-257.

https://www.infineon.com/cms/en/product/power/igbt/igbt-discretes/ikq40n120ch3/
1600V 30A IGBT:
https://www.infineon.com/cms/en/product/power/igbt/igbt-discretes/ihw30n160r5/
There needs to be some voltage margin and the highest voltage rating device will be more expensive than mid-range ones from the same family, there may be tradeoffs in other parameters such as ON resistance and speed. A 400V system may be close to 500V when the battery is fully charged.
Click to expand...

That\'s what clamping diode is for, to provide enough margin for less cost. I don\'t know about other EVs, but my Leaf never go much higher than 390V when full. 1600V should be enough for 800V to 1kV system.

Also don\'t forget that the 400V decision was made something like 15-20 years ago - the devices were not so capable.

These days the trend is to use silicon carbide FETs rather than IGBT devices as the latter is very limited in switching speed.
Click to expand...

But FETs can\'t beat IGBT in current capability, and how fast do we need for driving motors?
 
On Sunday, 4 September 2022 at 15:26:17 UTC-7, Ed Lee wrote:
On Sunday, September 4, 2022 at 2:46:22 PM UTC-7, ke...@kjwdesigns.com wrote:
..
With modern EVs the active devices IIGBT typically) in the motor driver were first available with breakdown voltages of the order of 1000V and so were only good for system voltage about half of that - 400V tended to be used.
I didn\'t read this carefully. But why half system voltage?
With SIC that has increased so 800V (that can go up to ~950V when fully charged) are practical.
If that\'s the case, we should go with 1200V. These IGBTs are amazing with 1200V 40A 500W (huge heat sink) in TO-257.

https://www.infineon.com/cms/en/product/power/igbt/igbt-discretes/ikq40n120ch3/
1600V 30A IGBT:
https://www.infineon.com/cms/en/product/power/igbt/igbt-discretes/ihw30n160r5/
There needs to be some voltage margin and the highest voltage rating device will be more expensive than mid-range ones from the same family, there may be tradeoffs in other parameters such as ON resistance and speed. A 400V system may be close to 500V when the battery is fully charged.
That\'s what clamping diode is for, to provide enough margin for less cost.. I don\'t know about other EVs, but my Leaf never go much higher than 390V when full. 1600V should be enough for 800V to 1kV system.
Click to expand...

I didn\'t say it wasn\'t.

Was it cheaply available 20 years ago?

Also don\'t forget that the 400V decision was made something like 15-20 years ago - the devices were not so capable.

These days the trend is to use silicon carbide FETs rather than IGBT devices as the latter is very limited in switching speed.
But FETs can\'t beat IGBT in current capability, and how fast do we need for driving motors?
Click to expand...

Around 10kHz is typical for modern ones. Your leaf is ~5kHz (presumably IGBT). The Prius that also uses IGBTs runs at 2.5kHz according to this web site:

https://e-nvh.eomys.com/what-is-the-switching-frequency-of-main-ev-hev-e-powertrains/

kw
 
On Sunday, September 4, 2022 at 3:36:47 PM UTC-7, ke...@kjwdesigns.com wrote:
On Sunday, 4 September 2022 at 15:26:17 UTC-7, Ed Lee wrote:
On Sunday, September 4, 2022 at 2:46:22 PM UTC-7, ke...@kjwdesigns.com wrote:
..
With modern EVs the active devices IIGBT typically) in the motor driver were first available with breakdown voltages of the order of 1000V and so were only good for system voltage about half of that - 400V tended to be used.
I didn\'t read this carefully. But why half system voltage?
With SIC that has increased so 800V (that can go up to ~950V when fully charged) are practical.
If that\'s the case, we should go with 1200V. These IGBTs are amazing with 1200V 40A 500W (huge heat sink) in TO-257.

https://www.infineon.com/cms/en/product/power/igbt/igbt-discretes/ikq40n120ch3/
1600V 30A IGBT:
https://www.infineon.com/cms/en/product/power/igbt/igbt-discretes/ihw30n160r5/
There needs to be some voltage margin and the highest voltage rating device will be more expensive than mid-range ones from the same family, there may be tradeoffs in other parameters such as ON resistance and speed. A 400V system may be close to 500V when the battery is fully charged.
That\'s what clamping diode is for, to provide enough margin for less cost. I don\'t know about other EVs, but my Leaf never go much higher than 390V when full. 1600V should be enough for 800V to 1kV system.
I didn\'t say it wasn\'t.

Was it cheaply available 20 years ago?
Also don\'t forget that the 400V decision was made something like 15-20 years ago - the devices were not so capable.

These days the trend is to use silicon carbide FETs rather than IGBT devices as the latter is very limited in switching speed.
But FETs can\'t beat IGBT in current capability, and how fast do we need for driving motors?
Around 10kHz is typical for modern ones. Your leaf is ~5kHz (presumably IGBT). The Prius that also uses IGBTs runs at 2.5kHz according to this web site:

https://e-nvh.eomys.com/what-is-the-switching-frequency-of-main-ev-hev-e-powertrains/
Click to expand...

The ihw30n160r5 (1600V 30A) can switch up to 60kHz, most IGBTs are fast enough for motors.
 
On Sunday, 4 September 2022 at 16:18:33 UTC-7, Ed Lee wrote:
....
But FETs can\'t beat IGBT in current capability, and how fast do we need for driving motors?
Around 10kHz is typical for modern ones. Your leaf is ~5kHz (presumably IGBT). The Prius that also uses IGBTs runs at 2.5kHz according to this web site:

https://e-nvh.eomys.com/what-is-the-switching-frequency-of-main-ev-hev-e-powertrains/
The ihw30n160r5 (1600V 30A) can switch up to 60kHz, most IGBTs are fast enough for motors.
Click to expand...

Maybe, but you can\'t avoid the 2 volt drop of IGBTs.

At 100 Amps that\'s 200W dissipation.

kw
 
On Sunday, September 4, 2022 at 6:30:29 PM UTC-7, ke...@kjwdesigns.com wrote:
On Sunday, 4 September 2022 at 16:18:33 UTC-7, Ed Lee wrote:
...
But FETs can\'t beat IGBT in current capability, and how fast do we need for driving motors?
Around 10kHz is typical for modern ones. Your leaf is ~5kHz (presumably IGBT). The Prius that also uses IGBTs runs at 2.5kHz according to this web site:

https://e-nvh.eomys.com/what-is-the-switching-frequency-of-main-ev-hev-e-powertrains/
The ihw30n160r5 (1600V 30A) can switch up to 60kHz, most IGBTs are fast enough for motors.
Maybe, but you can\'t avoid the 2 volt drop of IGBTs.

At 100 Amps that\'s 200W dissipation.
Click to expand...

I believe you can parallel IGBTs, just like FETs.
 
On Sunday, 4 September 2022 at 18:34:02 UTC-7, Ed Lee wrote:
On Sunday, September 4, 2022 at 6:30:29 PM UTC-7, ke...@.com wrote:
On Sunday, 4 September 2022 at 16:18:33 UTC-7, Ed Lee wrote:
...
But FETs can\'t beat IGBT in current capability, and how fast do we need for driving motors?
Around 10kHz is typical for modern ones. Your leaf is ~5kHz (presumably IGBT). The Prius that also uses IGBTs runs at 2.5kHz according to this web site:

https://e-nvh.eomys.com/what-is-the-switching-frequency-of-main-ev-hev-e-powertrains/
The ihw30n160r5 (1600V 30A) can switch up to 60kHz, most IGBTs are fast enough for motors.
Maybe, but you can\'t avoid the 2 volt drop of IGBTs.

At 100 Amps that\'s 200W dissipation.
I believe you can parallel IGBTs, just like FETs.
Click to expand...

Doesn\'t help much.

An IGBT has a minimum of a volt or on-voltage so even at low current..

kw
 
On Wednesday, September 7, 2022 at 9:48:45 AM UTC-4, Ed Lee wrote:
On Wednesday, September 7, 2022 at 3:27:38 AM UTC-7, Ricky wrote:
On Monday, September 5, 2022 at 7:26:43 PM UTC-4, lang...@fonz.dk wrote:
mandag den 5. september 2022 kl. 23.20.18 UTC+2 skrev upsid...@downunder.com:
On Sun, 04 Sep 2022 07:32:01 -0700, jla...@highlandsniptechnology.com
wrote:
High voltage needs thick insulation on the wire, and skinny wire
windings lose window area to insulation more than fat wires. And
insulation doesn\'t conduct heat as well as copper. Triple whammy.
400 Vdc is sufficient to drive a 120/208 V three phase motor with a
sine wave. 800 Vdc is sufficient for 230/400V motors. The insulation
thickness is not an issue for normal 230/400 V motors in kW size
motors.

The preference for 800 Vdc battery voltage is in the inverter. 1200 V
semiconductors are cheaply available and they should survive in a well
designed 800 Vdc system.

Using a higher voltage will reduce the current. The cost of a
transistor is usually proportional to the chip area which depends on
the current rating. Reducing the current (by using higher voltage)
requires smaller chips and may reduce total cost, if the higher
voltage doesn\'t significantly increase costs. Now that 1200 V devices
are cheaply available, why not go for 800 Vdc ?.

Going for 1500 Vdc would require 2 kV devices, which today is
expensive.
FIA Formula E all use a nominal 750V battery, so ~525V to ~880V

350kW rear wheel drive, 600kW four wheel regen
That would be hard on the battery. I wonder how good the warranty is. ;)
Depends on what the actual current is. My 80 kW motor typically draw around 70A (28kW) on local driving. Anyone got data on other EVs?
Click to expand...

600kW is beyond the output of my model X, even in Ludicrous mode. I\'ve never seen the car charge at faster than about 170 kW. I don\'t give a damn what the current is. The battery is not remotely designed to charge at 600kW! That might well rip all the tires loose from the pavement, if the traction control didn\'t kick in reducing the regen. It certainly feels like the regen is kicking in when it goes all out on acceleration at ~500 kW and 600+ HP. The car has a subtle side to side shift.

--

Rick C.

--++ Get 1,000 miles of free Supercharging
--++ Tesla referral code - https://ts.la/richard11209
 
On Wednesday, September 7, 2022 at 11:38:25 AM UTC-7, Ricky wrote:
On Wednesday, September 7, 2022 at 9:48:45 AM UTC-4, Ed Lee wrote:
On Wednesday, September 7, 2022 at 3:27:38 AM UTC-7, Ricky wrote:
On Monday, September 5, 2022 at 7:26:43 PM UTC-4, lang...@fonz.dk wrote:
mandag den 5. september 2022 kl. 23.20.18 UTC+2 skrev upsid...@downunder.com:
On Sun, 04 Sep 2022 07:32:01 -0700, jla...@highlandsniptechnology..com
wrote:
High voltage needs thick insulation on the wire, and skinny wire
windings lose window area to insulation more than fat wires. And
insulation doesn\'t conduct heat as well as copper. Triple whammy..
400 Vdc is sufficient to drive a 120/208 V three phase motor with a
sine wave. 800 Vdc is sufficient for 230/400V motors. The insulation
thickness is not an issue for normal 230/400 V motors in kW size
motors.

The preference for 800 Vdc battery voltage is in the inverter. 1200 V
semiconductors are cheaply available and they should survive in a well
designed 800 Vdc system.

Using a higher voltage will reduce the current. The cost of a
transistor is usually proportional to the chip area which depends on
the current rating. Reducing the current (by using higher voltage)
requires smaller chips and may reduce total cost, if the higher
voltage doesn\'t significantly increase costs. Now that 1200 V devices
are cheaply available, why not go for 800 Vdc ?.

Going for 1500 Vdc would require 2 kV devices, which today is
expensive.
FIA Formula E all use a nominal 750V battery, so ~525V to ~880V

350kW rear wheel drive, 600kW four wheel regen
That would be hard on the battery. I wonder how good the warranty is. ;)
Depends on what the actual current is. My 80 kW motor typically draw around 70A (28kW) on local driving. Anyone got data on other EVs?
600kW is beyond the output of my model X, even in Ludicrous mode. I\'ve never seen the car charge at faster than about 170 kW. I don\'t give a damn what the current is. The battery is not remotely designed to charge at 600kW! That might well rip all the tires loose from the pavement, if the traction control didn\'t kick in reducing the regen. It certainly feels like the regen is kicking in when it goes all out on acceleration at ~500 kW and 600+ HP. The car has a subtle side to side shift.
Click to expand...

Not for charging. 600W (1500A) max discharging/driving. But we want to know the typical, not just the max.
 
onsdag den 7. september 2022 kl. 17.13.11 UTC+2 skrev Ed Lee:
On Wednesday, September 7, 2022 at 8:07:51 AM UTC-7, lang...@fonz.dk wrote:
onsdag den 7. september 2022 kl. 15.48.45 UTC+2 skrev Ed Lee:
On Wednesday, September 7, 2022 at 3:27:38 AM UTC-7, Ricky wrote:
On Monday, September 5, 2022 at 7:26:43 PM UTC-4, lang...@fonz.dk wrote:
mandag den 5. september 2022 kl. 23.20.18 UTC+2 skrev upsid...@downunder.com:
On Sun, 04 Sep 2022 07:32:01 -0700, jla...@highlandsniptechnology.com
wrote:
High voltage needs thick insulation on the wire, and skinny wire
windings lose window area to insulation more than fat wires. And
insulation doesn\'t conduct heat as well as copper. Triple whammy.
400 Vdc is sufficient to drive a 120/208 V three phase motor with a
sine wave. 800 Vdc is sufficient for 230/400V motors. The insulation
thickness is not an issue for normal 230/400 V motors in kW size
motors.

The preference for 800 Vdc battery voltage is in the inverter. 1200 V
semiconductors are cheaply available and they should survive in a well
designed 800 Vdc system.

Using a higher voltage will reduce the current. The cost of a
transistor is usually proportional to the chip area which depends on
the current rating. Reducing the current (by using higher voltage)
requires smaller chips and may reduce total cost, if the higher
voltage doesn\'t significantly increase costs. Now that 1200 V devices
are cheaply available, why not go for 800 Vdc ?.

Going for 1500 Vdc would require 2 kV devices, which today is
expensive.
FIA Formula E all use a nominal 750V battery, so ~525V to ~880V

350kW rear wheel drive, 600kW four wheel regen
That would be hard on the battery. I wonder how good the warranty is. ;)
Depends on what the actual current is. My 80 kW motor typically draw around 70A (28kW) on local driving. Anyone got data on other EVs?
Formula E is racing, there\'s a 52kWh net energy allowance for a 45 minute race and afair they claim regen adds about 40%
What\'s the typical power/current draws? 52kWh/0.75 = 70 kW average?
Click to expand...

it is racing so pretty much constantly switching from max power to max regen

they claim ~40% of the energy used is regen, so 52kWh battery + ~35kWh regen = 87kWh , so ~116kW average

https://youtu.be/0Kk8PyPSdaM
 
On Sunday, September 4, 2022 at 6:36:47 PM UTC-4, ke...@kjwdesigns.com wrote:
On Sunday, 4 September 2022 at 15:26:17 UTC-7, Ed Lee wrote:
On Sunday, September 4, 2022 at 2:46:22 PM UTC-7, ke...@kjwdesigns.com wrote:
..
With modern EVs the active devices IIGBT typically) in the motor driver were first available with breakdown voltages of the order of 1000V and so were only good for system voltage about half of that - 400V tended to be used.
I didn\'t read this carefully. But why half system voltage?
With SIC that has increased so 800V (that can go up to ~950V when fully charged) are practical.
If that\'s the case, we should go with 1200V. These IGBTs are amazing with 1200V 40A 500W (huge heat sink) in TO-257.

https://www.infineon.com/cms/en/product/power/igbt/igbt-discretes/ikq40n120ch3/
1600V 30A IGBT:
https://www.infineon.com/cms/en/product/power/igbt/igbt-discretes/ihw30n160r5/
There needs to be some voltage margin and the highest voltage rating device will be more expensive than mid-range ones from the same family, there may be tradeoffs in other parameters such as ON resistance and speed. A 400V system may be close to 500V when the battery is fully charged.
That\'s what clamping diode is for, to provide enough margin for less cost. I don\'t know about other EVs, but my Leaf never go much higher than 390V when full. 1600V should be enough for 800V to 1kV system.
I didn\'t say it wasn\'t.

Was it cheaply available 20 years ago?
Also don\'t forget that the 400V decision was made something like 15-20 years ago - the devices were not so capable.

These days the trend is to use silicon carbide FETs rather than IGBT devices as the latter is very limited in switching speed.
But FETs can\'t beat IGBT in current capability, and how fast do we need for driving motors?
Around 10kHz is typical for modern ones. Your leaf is ~5kHz (presumably IGBT). The Prius that also uses IGBTs runs at 2.5kHz according to this web site:

https://e-nvh.eomys.com/what-is-the-switching-frequency-of-main-ev-hev-e-powertrains/
Click to expand...

I thought the Teslas ran up to 30 kHz in their motors.

--

Rick C.

---+ Get 1,000 miles of free Supercharging
---+ Tesla referral code - https://ts.la/richard11209
 
On Wednesday, September 7, 2022 at 12:10:02 PM UTC-7, lang...@fonz.dk wrote:
onsdag den 7. september 2022 kl. 17.13.11 UTC+2 skrev Ed Lee:
On Wednesday, September 7, 2022 at 8:07:51 AM UTC-7, lang...@fonz.dk wrote:
onsdag den 7. september 2022 kl. 15.48.45 UTC+2 skrev Ed Lee:
On Wednesday, September 7, 2022 at 3:27:38 AM UTC-7, Ricky wrote:
On Monday, September 5, 2022 at 7:26:43 PM UTC-4, lang...@fonz.dk wrote:
mandag den 5. september 2022 kl. 23.20.18 UTC+2 skrev upsid...@downunder.com:
On Sun, 04 Sep 2022 07:32:01 -0700, jla...@highlandsniptechnology.com
wrote:
High voltage needs thick insulation on the wire, and skinny wire
windings lose window area to insulation more than fat wires. And
insulation doesn\'t conduct heat as well as copper. Triple whammy.
400 Vdc is sufficient to drive a 120/208 V three phase motor with a
sine wave. 800 Vdc is sufficient for 230/400V motors. The insulation
thickness is not an issue for normal 230/400 V motors in kW size
motors.

The preference for 800 Vdc battery voltage is in the inverter. 1200 V
semiconductors are cheaply available and they should survive in a well
designed 800 Vdc system.

Using a higher voltage will reduce the current. The cost of a
transistor is usually proportional to the chip area which depends on
the current rating. Reducing the current (by using higher voltage)
requires smaller chips and may reduce total cost, if the higher
voltage doesn\'t significantly increase costs. Now that 1200 V devices
are cheaply available, why not go for 800 Vdc ?.

Going for 1500 Vdc would require 2 kV devices, which today is
expensive.
FIA Formula E all use a nominal 750V battery, so ~525V to ~880V

350kW rear wheel drive, 600kW four wheel regen
That would be hard on the battery. I wonder how good the warranty is. ;)
Depends on what the actual current is. My 80 kW motor typically draw around 70A (28kW) on local driving. Anyone got data on other EVs?
Formula E is racing, there\'s a 52kWh net energy allowance for a 45 minute race and afair they claim regen adds about 40%
What\'s the typical power/current draws? 52kWh/0.75 = 70 kW average?
it is racing so pretty much constantly switching from max power to max regen

they claim ~40% of the energy used is regen, so 52kWh battery + ~35kWh regen = 87kWh , so ~116kW average

https://youtu.be/0Kk8PyPSdaM
Click to expand...

That\'s pulling regen energy out of nowhere. I think it just mean more distance out of the 52kW battery.
 
onsdag den 7. september 2022 kl. 21.18.41 UTC+2 skrev Ed Lee:
On Wednesday, September 7, 2022 at 12:10:02 PM UTC-7, lang...@fonz.dk wrote:
onsdag den 7. september 2022 kl. 17.13.11 UTC+2 skrev Ed Lee:
On Wednesday, September 7, 2022 at 8:07:51 AM UTC-7, lang...@fonz.dk wrote:
onsdag den 7. september 2022 kl. 15.48.45 UTC+2 skrev Ed Lee:
On Wednesday, September 7, 2022 at 3:27:38 AM UTC-7, Ricky wrote:
On Monday, September 5, 2022 at 7:26:43 PM UTC-4, lang...@fonz.dk wrote:
mandag den 5. september 2022 kl. 23.20.18 UTC+2 skrev upsid...@downunder.com:
On Sun, 04 Sep 2022 07:32:01 -0700, jla...@highlandsniptechnology.com
wrote:
High voltage needs thick insulation on the wire, and skinny wire
windings lose window area to insulation more than fat wires. And
insulation doesn\'t conduct heat as well as copper. Triple whammy.
400 Vdc is sufficient to drive a 120/208 V three phase motor with a
sine wave. 800 Vdc is sufficient for 230/400V motors. The insulation
thickness is not an issue for normal 230/400 V motors in kW size
motors.

The preference for 800 Vdc battery voltage is in the inverter. 1200 V
semiconductors are cheaply available and they should survive in a well
designed 800 Vdc system.

Using a higher voltage will reduce the current. The cost of a
transistor is usually proportional to the chip area which depends on
the current rating. Reducing the current (by using higher voltage)
requires smaller chips and may reduce total cost, if the higher
voltage doesn\'t significantly increase costs. Now that 1200 V devices
are cheaply available, why not go for 800 Vdc ?.

Going for 1500 Vdc would require 2 kV devices, which today is
expensive.
FIA Formula E all use a nominal 750V battery, so ~525V to ~880V

350kW rear wheel drive, 600kW four wheel regen
That would be hard on the battery. I wonder how good the warranty is. ;)
Depends on what the actual current is. My 80 kW motor typically draw around 70A (28kW) on local driving. Anyone got data on other EVs?
Formula E is racing, there\'s a 52kWh net energy allowance for a 45 minute race and afair they claim regen adds about 40%
What\'s the typical power/current draws? 52kWh/0.75 = 70 kW average?
it is racing so pretty much constantly switching from max power to max regen

they claim ~40% of the energy used is regen, so 52kWh battery + ~35kWh regen = 87kWh , so ~116kW average

https://youtu.be/0Kk8PyPSdaM
That\'s pulling regen energy out of nowhere. I think it just mean more distance out of the 52kW battery.
Click to expand...

it is not energy out of nowhere, it is reusing the energy rather turning it into heat in the brakes
 
On Wednesday, September 7, 2022 at 1:04:29 PM UTC-7, lang...@fonz.dk wrote:
onsdag den 7. september 2022 kl. 21.18.41 UTC+2 skrev Ed Lee:
On Wednesday, September 7, 2022 at 12:10:02 PM UTC-7, lang...@fonz.dk wrote:
onsdag den 7. september 2022 kl. 17.13.11 UTC+2 skrev Ed Lee:
On Wednesday, September 7, 2022 at 8:07:51 AM UTC-7, lang...@fonz.dk wrote:
onsdag den 7. september 2022 kl. 15.48.45 UTC+2 skrev Ed Lee:
On Wednesday, September 7, 2022 at 3:27:38 AM UTC-7, Ricky wrote:
On Monday, September 5, 2022 at 7:26:43 PM UTC-4, lang...@fonz.dk wrote:
mandag den 5. september 2022 kl. 23.20.18 UTC+2 skrev upsid...@downunder.com:
On Sun, 04 Sep 2022 07:32:01 -0700, jla...@highlandsniptechnology.com
wrote:
High voltage needs thick insulation on the wire, and skinny wire
windings lose window area to insulation more than fat wires. And
insulation doesn\'t conduct heat as well as copper. Triple whammy.
400 Vdc is sufficient to drive a 120/208 V three phase motor with a
sine wave. 800 Vdc is sufficient for 230/400V motors. The insulation
thickness is not an issue for normal 230/400 V motors in kW size
motors.

The preference for 800 Vdc battery voltage is in the inverter. 1200 V
semiconductors are cheaply available and they should survive in a well
designed 800 Vdc system.

Using a higher voltage will reduce the current. The cost of a
transistor is usually proportional to the chip area which depends on
the current rating. Reducing the current (by using higher voltage)
requires smaller chips and may reduce total cost, if the higher
voltage doesn\'t significantly increase costs. Now that 1200 V devices
are cheaply available, why not go for 800 Vdc ?.

Going for 1500 Vdc would require 2 kV devices, which today is
expensive.
FIA Formula E all use a nominal 750V battery, so ~525V to ~880V

350kW rear wheel drive, 600kW four wheel regen
That would be hard on the battery. I wonder how good the warranty is. ;)
Depends on what the actual current is. My 80 kW motor typically draw around 70A (28kW) on local driving. Anyone got data on other EVs?
Formula E is racing, there\'s a 52kWh net energy allowance for a 45 minute race and afair they claim regen adds about 40%
What\'s the typical power/current draws? 52kWh/0.75 = 70 kW average?
it is racing so pretty much constantly switching from max power to max regen

they claim ~40% of the energy used is regen, so 52kWh battery + ~35kWh regen = 87kWh , so ~116kW average

https://youtu.be/0Kk8PyPSdaM
That\'s pulling regen energy out of nowhere. I think it just mean more distance out of the 52kW battery.
it is not energy out of nowhere, it is reusing the energy rather turning it into heat in the brakes
Click to expand...

But total energy is still 52kWh, with average of 70 kW.
 
onsdag den 7. september 2022 kl. 22.08.32 UTC+2 skrev Ed Lee:
On Wednesday, September 7, 2022 at 1:04:29 PM UTC-7, lang...@fonz.dk wrote:
onsdag den 7. september 2022 kl. 21.18.41 UTC+2 skrev Ed Lee:
On Wednesday, September 7, 2022 at 12:10:02 PM UTC-7, lang...@fonz.dk wrote:
onsdag den 7. september 2022 kl. 17.13.11 UTC+2 skrev Ed Lee:
On Wednesday, September 7, 2022 at 8:07:51 AM UTC-7, lang...@fonz.dk wrote:
onsdag den 7. september 2022 kl. 15.48.45 UTC+2 skrev Ed Lee:
On Wednesday, September 7, 2022 at 3:27:38 AM UTC-7, Ricky wrote:
On Monday, September 5, 2022 at 7:26:43 PM UTC-4, lang...@fonz.dk wrote:
mandag den 5. september 2022 kl. 23.20.18 UTC+2 skrev upsid...@downunder.com:
On Sun, 04 Sep 2022 07:32:01 -0700, jla...@highlandsniptechnology.com
wrote:
High voltage needs thick insulation on the wire, and skinny wire
windings lose window area to insulation more than fat wires. And
insulation doesn\'t conduct heat as well as copper. Triple whammy.
400 Vdc is sufficient to drive a 120/208 V three phase motor with a
sine wave. 800 Vdc is sufficient for 230/400V motors. The insulation
thickness is not an issue for normal 230/400 V motors in kW size
motors.

The preference for 800 Vdc battery voltage is in the inverter. 1200 V
semiconductors are cheaply available and they should survive in a well
designed 800 Vdc system.

Using a higher voltage will reduce the current. The cost of a
transistor is usually proportional to the chip area which depends on
the current rating. Reducing the current (by using higher voltage)
requires smaller chips and may reduce total cost, if the higher
voltage doesn\'t significantly increase costs. Now that 1200 V devices
are cheaply available, why not go for 800 Vdc ?.

Going for 1500 Vdc would require 2 kV devices, which today is
expensive.
FIA Formula E all use a nominal 750V battery, so ~525V to ~880V

350kW rear wheel drive, 600kW four wheel regen
That would be hard on the battery. I wonder how good the warranty is. ;)
Depends on what the actual current is. My 80 kW motor typically draw around 70A (28kW) on local driving. Anyone got data on other EVs?
Formula E is racing, there\'s a 52kWh net energy allowance for a 45 minute race and afair they claim regen adds about 40%
What\'s the typical power/current draws? 52kWh/0.75 = 70 kW average?
it is racing so pretty much constantly switching from max power to max regen

they claim ~40% of the energy used is regen, so 52kWh battery + ~35kWh regen = 87kWh , so ~116kW average

https://youtu.be/0Kk8PyPSdaM
That\'s pulling regen energy out of nowhere. I think it just mean more distance out of the 52kW battery.
it is not energy out of nowhere, it is reusing the energy rather turning it into heat in the brakes
But total energy is still 52kWh, with average of 70 kW.
Click to expand...

netto, if they didn\'t have regen they would need a battery nearly twice the size to go as fast
 
On Wednesday, September 7, 2022 at 1:27:08 PM UTC-7, lang...@fonz.dk wrote:
onsdag den 7. september 2022 kl. 22.08.32 UTC+2 skrev Ed Lee:
On Wednesday, September 7, 2022 at 1:04:29 PM UTC-7, lang...@fonz.dk wrote:
onsdag den 7. september 2022 kl. 21.18.41 UTC+2 skrev Ed Lee:
On Wednesday, September 7, 2022 at 12:10:02 PM UTC-7, lang...@fonz.dk wrote:
onsdag den 7. september 2022 kl. 17.13.11 UTC+2 skrev Ed Lee:
On Wednesday, September 7, 2022 at 8:07:51 AM UTC-7, lang...@fonz.dk wrote:
onsdag den 7. september 2022 kl. 15.48.45 UTC+2 skrev Ed Lee:
On Wednesday, September 7, 2022 at 3:27:38 AM UTC-7, Ricky wrote:
On Monday, September 5, 2022 at 7:26:43 PM UTC-4, lang...@fonz.dk wrote:
mandag den 5. september 2022 kl. 23.20.18 UTC+2 skrev upsid...@downunder.com:
On Sun, 04 Sep 2022 07:32:01 -0700, jla...@highlandsniptechnology.com
wrote:
High voltage needs thick insulation on the wire, and skinny wire
windings lose window area to insulation more than fat wires. And
insulation doesn\'t conduct heat as well as copper. Triple whammy.
400 Vdc is sufficient to drive a 120/208 V three phase motor with a
sine wave. 800 Vdc is sufficient for 230/400V motors. The insulation
thickness is not an issue for normal 230/400 V motors in kW size
motors.

The preference for 800 Vdc battery voltage is in the inverter. 1200 V
semiconductors are cheaply available and they should survive in a well
designed 800 Vdc system.

Using a higher voltage will reduce the current. The cost of a
transistor is usually proportional to the chip area which depends on
the current rating. Reducing the current (by using higher voltage)
requires smaller chips and may reduce total cost, if the higher
voltage doesn\'t significantly increase costs. Now that 1200 V devices
are cheaply available, why not go for 800 Vdc ?.

Going for 1500 Vdc would require 2 kV devices, which today is
expensive.
FIA Formula E all use a nominal 750V battery, so ~525V to ~880V

350kW rear wheel drive, 600kW four wheel regen
That would be hard on the battery. I wonder how good the warranty is. ;)
Depends on what the actual current is. My 80 kW motor typically draw around 70A (28kW) on local driving. Anyone got data on other EVs?
Formula E is racing, there\'s a 52kWh net energy allowance for a 45 minute race and afair they claim regen adds about 40%
What\'s the typical power/current draws? 52kWh/0.75 = 70 kW average?
it is racing so pretty much constantly switching from max power to max regen

they claim ~40% of the energy used is regen, so 52kWh battery + ~35kWh regen = 87kWh , so ~116kW average

https://youtu.be/0Kk8PyPSdaM
That\'s pulling regen energy out of nowhere. I think it just mean more distance out of the 52kW battery.
it is not energy out of nowhere, it is reusing the energy rather turning it into heat in the brakes
But total energy is still 52kWh, with average of 70 kW.
netto, if they didn\'t have regen they would need a battery nearly twice the size to go as fast
Click to expand...

So, if we go constantly on flat land, we have 52kWh battery. But if we go over a hill, we got 87kWh battery?
 
onsdag den 7. september 2022 kl. 23.27.55 UTC+2 skrev Ed Lee:
On Wednesday, September 7, 2022 at 1:27:08 PM UTC-7, lang...@fonz.dk wrote:
onsdag den 7. september 2022 kl. 22.08.32 UTC+2 skrev Ed Lee:
On Wednesday, September 7, 2022 at 1:04:29 PM UTC-7, lang...@fonz.dk wrote:
onsdag den 7. september 2022 kl. 21.18.41 UTC+2 skrev Ed Lee:
On Wednesday, September 7, 2022 at 12:10:02 PM UTC-7, lang...@fonz.dk wrote:
onsdag den 7. september 2022 kl. 17.13.11 UTC+2 skrev Ed Lee:
On Wednesday, September 7, 2022 at 8:07:51 AM UTC-7, lang...@fonz.dk wrote:
onsdag den 7. september 2022 kl. 15.48.45 UTC+2 skrev Ed Lee:
On Wednesday, September 7, 2022 at 3:27:38 AM UTC-7, Ricky wrote:
On Monday, September 5, 2022 at 7:26:43 PM UTC-4, lang...@fonz.dk wrote:
mandag den 5. september 2022 kl. 23.20.18 UTC+2 skrev upsid...@downunder.com:
On Sun, 04 Sep 2022 07:32:01 -0700, jla...@highlandsniptechnology.com
wrote:
High voltage needs thick insulation on the wire, and skinny wire
windings lose window area to insulation more than fat wires. And
insulation doesn\'t conduct heat as well as copper. Triple whammy.
400 Vdc is sufficient to drive a 120/208 V three phase motor with a
sine wave. 800 Vdc is sufficient for 230/400V motors. The insulation
thickness is not an issue for normal 230/400 V motors in kW size
motors.

The preference for 800 Vdc battery voltage is in the inverter. 1200 V
semiconductors are cheaply available and they should survive in a well
designed 800 Vdc system.

Using a higher voltage will reduce the current. The cost of a
transistor is usually proportional to the chip area which depends on
the current rating. Reducing the current (by using higher voltage)
requires smaller chips and may reduce total cost, if the higher
voltage doesn\'t significantly increase costs. Now that 1200 V devices
are cheaply available, why not go for 800 Vdc ?.

Going for 1500 Vdc would require 2 kV devices, which today is
expensive.
FIA Formula E all use a nominal 750V battery, so ~525V to ~880V

350kW rear wheel drive, 600kW four wheel regen
That would be hard on the battery. I wonder how good the warranty is. ;)
Depends on what the actual current is. My 80 kW motor typically draw around 70A (28kW) on local driving. Anyone got data on other EVs?
Formula E is racing, there\'s a 52kWh net energy allowance for a 45 minute race and afair they claim regen adds about 40%
What\'s the typical power/current draws? 52kWh/0.75 = 70 kW average?
it is racing so pretty much constantly switching from max power to max regen

they claim ~40% of the energy used is regen, so 52kWh battery + ~35kWh regen = 87kWh , so ~116kW average

https://youtu.be/0Kk8PyPSdaM
That\'s pulling regen energy out of nowhere. I think it just mean more distance out of the 52kW battery.
it is not energy out of nowhere, it is reusing the energy rather turning it into heat in the brakes
But total energy is still 52kWh, with average of 70 kW.
netto, if they didn\'t have regen they would need a battery nearly twice the size to go as fast
So, if we go constantly on flat land, we have 52kWh battery. But if we go over a hill, we got 87kWh battery?
Click to expand...

many hills. e.g. if it takes 5kWh to get up the hill you can go up and down the hill 10 times with a 50kWh battery
if you can regen 3kWh every time you go downhill, you can go up and down the hill the same 10 times with just a 20kWh battery
 
On Wednesday, September 7, 2022 at 3:10:02 PM UTC-4, lang...@fonz.dk wrote:
onsdag den 7. september 2022 kl. 17.13.11 UTC+2 skrev Ed Lee:
On Wednesday, September 7, 2022 at 8:07:51 AM UTC-7, lang...@fonz.dk wrote:
onsdag den 7. september 2022 kl. 15.48.45 UTC+2 skrev Ed Lee:
On Wednesday, September 7, 2022 at 3:27:38 AM UTC-7, Ricky wrote:
On Monday, September 5, 2022 at 7:26:43 PM UTC-4, lang...@fonz.dk wrote:
mandag den 5. september 2022 kl. 23.20.18 UTC+2 skrev upsid...@downunder.com:
On Sun, 04 Sep 2022 07:32:01 -0700, jla...@highlandsniptechnology.com
wrote:
High voltage needs thick insulation on the wire, and skinny wire
windings lose window area to insulation more than fat wires. And
insulation doesn\'t conduct heat as well as copper. Triple whammy.
400 Vdc is sufficient to drive a 120/208 V three phase motor with a
sine wave. 800 Vdc is sufficient for 230/400V motors. The insulation
thickness is not an issue for normal 230/400 V motors in kW size
motors.

The preference for 800 Vdc battery voltage is in the inverter. 1200 V
semiconductors are cheaply available and they should survive in a well
designed 800 Vdc system.

Using a higher voltage will reduce the current. The cost of a
transistor is usually proportional to the chip area which depends on
the current rating. Reducing the current (by using higher voltage)
requires smaller chips and may reduce total cost, if the higher
voltage doesn\'t significantly increase costs. Now that 1200 V devices
are cheaply available, why not go for 800 Vdc ?.

Going for 1500 Vdc would require 2 kV devices, which today is
expensive.
FIA Formula E all use a nominal 750V battery, so ~525V to ~880V

350kW rear wheel drive, 600kW four wheel regen
That would be hard on the battery. I wonder how good the warranty is. ;)
Depends on what the actual current is. My 80 kW motor typically draw around 70A (28kW) on local driving. Anyone got data on other EVs?
Formula E is racing, there\'s a 52kWh net energy allowance for a 45 minute race and afair they claim regen adds about 40%
What\'s the typical power/current draws? 52kWh/0.75 = 70 kW average?
it is racing so pretty much constantly switching from max power to max regen

they claim ~40% of the energy used is regen, so 52kWh battery + ~35kWh regen = 87kWh , so ~116kW average

https://youtu.be/0Kk8PyPSdaM
Click to expand...

What use is the average as calculated from the battery and the regen use? Is this about determining the cooling requirement?

--

Rick C.

-+-- Get 1,000 miles of free Supercharging
-+-- Tesla referral code - https://ts.la/richard11209
 
On Wednesday, September 7, 2022 at 4:08:32 PM UTC-4, Ed Lee wrote:
On Wednesday, September 7, 2022 at 1:04:29 PM UTC-7, lang...@fonz.dk wrote:
onsdag den 7. september 2022 kl. 21.18.41 UTC+2 skrev Ed Lee:
On Wednesday, September 7, 2022 at 12:10:02 PM UTC-7, lang...@fonz.dk wrote:
onsdag den 7. september 2022 kl. 17.13.11 UTC+2 skrev Ed Lee:
On Wednesday, September 7, 2022 at 8:07:51 AM UTC-7, lang...@fonz.dk wrote:
onsdag den 7. september 2022 kl. 15.48.45 UTC+2 skrev Ed Lee:
On Wednesday, September 7, 2022 at 3:27:38 AM UTC-7, Ricky wrote:
On Monday, September 5, 2022 at 7:26:43 PM UTC-4, lang...@fonz.dk wrote:
mandag den 5. september 2022 kl. 23.20.18 UTC+2 skrev upsid...@downunder.com:
On Sun, 04 Sep 2022 07:32:01 -0700, jla...@highlandsniptechnology.com
wrote:
High voltage needs thick insulation on the wire, and skinny wire
windings lose window area to insulation more than fat wires. And
insulation doesn\'t conduct heat as well as copper. Triple whammy.
400 Vdc is sufficient to drive a 120/208 V three phase motor with a
sine wave. 800 Vdc is sufficient for 230/400V motors. The insulation
thickness is not an issue for normal 230/400 V motors in kW size
motors.

The preference for 800 Vdc battery voltage is in the inverter. 1200 V
semiconductors are cheaply available and they should survive in a well
designed 800 Vdc system.

Using a higher voltage will reduce the current. The cost of a
transistor is usually proportional to the chip area which depends on
the current rating. Reducing the current (by using higher voltage)
requires smaller chips and may reduce total cost, if the higher
voltage doesn\'t significantly increase costs. Now that 1200 V devices
are cheaply available, why not go for 800 Vdc ?.

Going for 1500 Vdc would require 2 kV devices, which today is
expensive.
FIA Formula E all use a nominal 750V battery, so ~525V to ~880V

350kW rear wheel drive, 600kW four wheel regen
That would be hard on the battery. I wonder how good the warranty is. ;)
Depends on what the actual current is. My 80 kW motor typically draw around 70A (28kW) on local driving. Anyone got data on other EVs?
Formula E is racing, there\'s a 52kWh net energy allowance for a 45 minute race and afair they claim regen adds about 40%
What\'s the typical power/current draws? 52kWh/0.75 = 70 kW average?
it is racing so pretty much constantly switching from max power to max regen

they claim ~40% of the energy used is regen, so 52kWh battery + ~35kWh regen = 87kWh , so ~116kW average

https://youtu.be/0Kk8PyPSdaM
That\'s pulling regen energy out of nowhere. I think it just mean more distance out of the 52kW battery.
it is not energy out of nowhere, it is reusing the energy rather turning it into heat in the brakes
But total energy is still 52kWh, with average of 70 kW.
Click to expand...

The motor sees the energy from the battery, then the energy from regeneration, twice, once in each direction.

What are you trying to figure out???

--

Rick C.

-+-+ Get 1,000 miles of free Supercharging
-+-+ Tesla referral code - https://ts.la/richard11209
 
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