Active pre-charge/inrush control

[DeNew]

Hi all.
Frankly, I don't know why transistors are needed, it's different for everyone ))
I made this for myself a long time ago and there are no problems with smooth charging of capacitors in the controller.

 

[fechter]

Thanks for posting that. Most large EVs use mechanical relays. Above about 100v, they will probably be the most cost effective.
For high power setups, you could use a BMS on the pack to power the dc-dc converter that is running the relay coils, but have the main load run straight off the pack without going through the BMS and have no limitation on current due to the BMS. If the BMS trips due to undervoltage on a cell group, the main relay will open.

 

[Otto44]

Hi all.
Frankly, I don't know why transistors are needed, it's different for everyone ))
I made this for myself a long time ago and there are no problems with smooth charging of capacitors in the controller.

Because of weight and space?

 

[harrisonpatm]

Thanks for posting that. Most large EVs use mechanical relays. Above about 100v, they will probably be the most cost effective.
For high power setups, you could use a BMS on the pack to power the dc-dc converter that is running the relay coils, but have the main load run straight off the pack without going through the BMS and have no limitation on current due to the BMS. If the BMS trips due to undervoltage on a cell group, the main relay will open.

This, and the above wiring diagram, is basically exactly how I have my current motorcycle wired. Technically the DC/DC is always on and technically always draining power. But I ride so often that a few watts is unnoticeable against my 9.5kwh pack. And if I really did want to turn it off all the way, I could turn off my BMS, which would kill power to the converter itself.

 

[DeNew]

Из-за веса и пространства?

No, it's just easier for me this way

 

[DeNew]

This, and the above wiring diagram, is basically exactly how I have my current motorcycle wired. Technically the DC/DC is always on and technically always draining power. But I ride so ot a few watts is unnoticeable against my 9.5kwh pack. And if I really did want to turn it off all the way, I could turn off my BMS, which would kill power to the converter itself.

Yes, I also drive often, charge often. BMS smart, there is a little control, so far so good, and then life will show.

 

[harrisonpatm]

This, and the above wiring diagram, is basically exactly how I have my current motorcycle wired. Technically the DC/DC is always on and technically always draining power. But I ride so often that a few watts is unnoticeable against my 9.5kwh pack. And if I really did want to turn it off all the way, I could turn off my BMS, which would kill power to the converter itself.

But, on the other side of the coin. I use the same system for my small moped build. It only has a 2kwh battery pack by comparison. I also ride it much less often, perhaps 1-2 times per week, sometimes I go 2 weeks straight without riding it. If I leave the battery connected for a week, both the DC/DC converter and the precharge resistor lightly drain the battery, and I can see a noticeable loss of about 10-15% over a week or two. So, for that system, easy fix: I just have a service disconnect breaker right after the battery that I can easily flip on and off if I know I'm going to be letting the moped sit for a few days.

 

[DeNew]

Ehhh good scheme and controller)
When I make a jet bike I'll think about it)
(12000W motor load) everything is in it, and soft atart (SIAPT96800)