Leaf gen 2 and ennoid BMS

[Riwi]

Hi!
Working on an electric drivetrain for a boat. I will be using a leaf gen 2 motor & driver with the OI-board. The BMS is Ennoid gen1 LV.
Both the BMS and the Leaf can control the pre-charge but I understand it will want OI to do it so that we don’t have any problems with unwanted shut-down during operations, this could potentially harm the leaf driver.

In the Ennoid BMS I can disable the pre-charge and I can use the +12V, that’s normally used to close the main contactor, to start up the IO.
The startup sequence would be as follows:
1. BMS is initiated via switch
2. If cell specs are within range a +12V signal will be activated from the "discharge" out put on the BMS board.
3. The +12V signal is directly connected to the ON and IGN pins on the OI.

In the case of a battery failure or low/high SOC the BMS will deactivate the +12V signal and this will stop the OI.

Is this a good approach or should ON and IGN be handled separately? For example, I could choose to only control IGN via BMS and let ON be a separate switch.



Thanks

Rikard

[johu]

The start input should only be momentary. I think switching the forward input via your BMS will cause a more graceful shutdown. And also allows restarting while the motor is still spinning.

So 12V via switch, start via a button and FWD via the BMS.

[arber333]

The start input should only be momentary. I think switching the forward input via your BMS will cause a more graceful shutdown. And also allows restarting while the motor is still spinning.

So 12V via switch, start via a button and FWD via the BMS.

Or you can use a latching relay powered from your "enable" (2nd) key position and is triggered by "starter" (3rd) key position. This goes off if you turn the key off anyway so that is a good way to have ON/OFF capability for restart while driving. Precharge is wired to "enable" (2nd) position and DC contactor to latching relay itself.

Warning !!! With PMSM motors this could cause damage to inverter if DC contactor is turned off during driving.

[Riwi]

The start input should only be momentary. I think switching the forward input via your BMS will cause a more graceful shutdown. And also allows restarting while the motor is still spinning.

So 12V via switch, start via a button and FWD via the BMS.

Ok, lets see if I got this right.

12V controlled by "main 12V switch" in the boat. Start via momentary push button (Pin 22).
Used the BMS to disable FWD signal if cells are out of spec?

In orther words I would have a normally opened relay, inline with the FWD signal. When all is ok the BMS will keep that realy closed and if an error is triggered in the BMS the open the realy and disable FWD-drive.

The main objective here is to not blow any drivers

[Riwi]

The start input should only be momentary. I think switching the forward input via your BMS will cause a more graceful shutdown. And also allows restarting while the motor is still spinning.

So 12V via switch, start via a button and FWD via the BMS.

Or you can use a latching relay powered from your "enable" (2nd) key position and is triggered by "starter" (3rd) key position. This goes off if you turn the key off anyway so that is a good way to have ON/OFF capability for restart while driving. Precharge is wired to "enable" (2nd) position and DC contactor to latching relay itself.

Warning !!! With PMSM motors this could cause damage to inverter if DC contactor is turned off during driving.

When it comes to causing damage, do we know under what conditions damage is caused? This a boat with a propeller and we will use approx 20kw max. Cruising is approx 12kw. I know its overkill to use the leaf but we will anyways.

The ennoid has build in precharge and control if main contactor which makes the setup very simple. But the main objective is to not fry stuff if possible.

[arber333]

When it comes to causing damage, do we know under what conditions damage is caused? This a boat with a propeller and we will use approx 20kw max. Cruising is approx 12kw. I know its overkill to use the leaf but we will anyways.

The ennoid has build in precharge and control if main contactor which makes the setup very simple. But the main objective is to not fry stuff if possible.

Hah! Sorry i guess damage would be caused if regen energy would need to go somewhere inside main inverter cap without battery connected.
You could try how much power regen has if you relese throttle and boat is still gliding along.

In my car i wired notaus to disable inverter PWM generation not DC contactor.