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    Active pre-charge/inrush control

    Good discussion. I was going to mention the same thing about the duty cycle control option. There are specialized drivers that do just that but of course no reason why an MCU can't do it. I was going to try it with my controller design. The idea is to limit the current with very low duty and...
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    Active pre-charge/inrush control

    The regen will work simply because body diodes in mosfets are conducting in reverse regardless whether the mosfets are on or off. This is kind of downside compared to a contactor that turns off the current flow in both directions. Most BMSes use mosfets in series to deal with that issue but of...
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    HESC V1 150v 600Amp VESC based motor controller

    You can certainly play around issues by tuning values and it can work for a particular situation. The sensorless transition issue can be mitigated by pushing the switchover eRPMs higher when the power demand during acceleration tapers out the switchover is not as dramatic. It may work good...
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    HESC V1 150v 600Amp VESC based motor controller

    This is typical for most hardware running vesc - I brought this up back in 2020 (Sensorless Transition and Deadtime Distortion | VESC Project) and there has been a lot of discussion about it in other threads. There are a few theories on why this is happening but my personal finding is that it's...
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    Active pre-charge/inrush control

    This is the design adopted for the PV-nextGen controllers, three 210A 150v rated mosfets are used for the contactor/pre-charge, and they are mounted on the power stage IMS board sharing the heatsink with the phase switches. The zener closest to the mosfet is a TVS to protect it from the voltage...
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    Active pre-charge/inrush control

    I've been using a modified version of the design with the added auxiliary turn-off circuit, TVS, and the capacitor from gate to source rather than the drain. It has worked fine overall even above 100v. One minor issue is that mosfets in the off state prevent the current flow from the battery to...
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    PV NextGen FOC 100-180v 36kw max - $799

    Going out tomorrow. Please PM for personal comm.
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    PV NextGen FOC 100-180v 36kw max - $799

    Response sent.
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    PV NextGen FOC 100-180v 36kw max - $799

    yes, available. Please, PM if you have trouble ordering.
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    GaN and IMS MESC controller boards

    yes, after-sale support can be daunting but there are some measures you can take to minimize it: - good and simple documentation, quick-start guides - pre-configured presets (mostly implemented in software/firmware) simplifying setup - remote logging to quickly pinpoint and resolve the issue...
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    PV NextGen FOC 100-180v 36kw max - $799

    On its way! Comes with built in pre-charge now, so it was worth the wait!
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    GaN and IMS MESC controller boards

    Reading this, I felt like reliving my past experience a few years back. Building a prototype and building a product are two different levels of effort and investment in terms of sweat, blood, tears, time, and money. Kudos you recognized that early.
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    Active pre-charge/inrush control

    Depends on the mosfet threshold used but simulation shows this with 2v threshold and 10uf +1M RC filter, at 100v. About 3 sec. Red is the gate, yellow is current and green is voltage. Using a thermistor sounds like throwing yet another variable. I don't see where it would add value in this case...
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    Active pre-charge/inrush control

    Just an update. TVS on the gate is a must to cover all possible scenarios such plugging in battery when the switch is on. That can cause spikes under some circumstances as shown above. Zeners are not able to handle transients. I've used the delayed gate charge approach at this time (as opposed...
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    PV NextGen FOC 100-180v 36kw max - $799

    A quick update: NextGen controllers now have built-in pre-charge and hi-voltage connect/disconnect features for additional safety. Based on modified version of Fechter inrush control circuit discussed here: https://endless-sphere.com/sphere/threads/active-pre-charge-inrush-control.40142/page-31
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    HESC V1 150v 600Amp VESC based motor controller

    You can add PV NextGen design to that list: it has had the hardware overcurrent and overvoltage protection from day one. It's not that hard or expensive to implement, just a few comparators and proper gate drivers that have disable pins. It saved me quite a few power stages from blowing up while...
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    Active pre-charge/inrush control

    The spike can be fixed. I think the bigger issue is getting full battery voltage on the gate when battery negative gets disconnected.
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    Active pre-charge/inrush control

    Yes, of course, this all can be achieved with separate mosfets for pre-charge and the main contactor mosfets, specialized gate drivers, dedicated power supplies, and MCU controlled duty cycles. However, I think the appeal of this approach was to make it elegantly simple. Possibly a silver...
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    HESC V1 150v 600Amp VESC based motor controller

    Good discussion on the pre-charge and the contactor here: Active pre-charge/inrush control I think we are close to making it work.
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    Active pre-charge/inrush control

    Currents may peak on the phases but detection uses maybe 2-3amps from the battery.
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    Active pre-charge/inrush control

    Ah, cool. IHNCWUS (stands for: I had no clue what you said :). Motor detection (R and L and flux) use a few amps for detection - it shouldn't be any different from just running the motor from the battery or switch perspective. As described above, however, I had a situation where Phase A (first...
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    Active pre-charge/inrush control

    What does MRR stand for?
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    Active pre-charge/inrush control

    My original design for this had two fets: 1 smaller for pre-charge and the main group of fets. Both circuits independently controlled by MCU. I scrapped that design. Additional complexity, dependencies = more opportunities for things to go wrong. Anyway, I made some progress with the above...
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    PV NextGen FOC 100-180v 36kw max - $799

    For the motor temperature to show, you would need a temperature sensor on the motor coils and the wires running back to thee controller (typically bundled with hall sensor wires). Assuming your controller runs a vesc firmware and the type of a sensor is configured correctly, the motor...
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    Active pre-charge/inrush control

    I take it back. All works fine at 53v input voltage. As soon as I bump up the voltage to 80v, mosfets blow up. It comes with a muffled "click" seemingly coming from the mosfets approximately one second after the circuit is turned on (about the time the gate voltage is supposed to ramp up to...
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