Infineon 40A controller failure

[TheThirdWheel]

Hi guys,

I have a sensored Infineon 40A controller (12xIRFB4110), 36-72V connected to a Crystalyte X5304 and running at ~72V. It has just up and died without warning. The controller still powers up and activates the CA, but there seems to be no power going to the hub motor. A sensor got fried in the motor, and after replacing all 3 sensors, the motor still does absolutely nothing when connected to the controller when the throttle is applied.
I know that the motor should at least try and rotate, cog etc regardless of hall sensor and phase wire configuration. To make sure it was the controller that was at fault I jerry-rigged a cheap Chinese controller I got off eBay to the motor, connected the same throttle and battery pack, and it ran flawlessly (after figuring out the hall/phase wire colour coding).
So now my question is, what could possible be wrong with the Infineon controller? The MOSFETs are all fine according to the testing procedures here:

http://www.ebikes.ca/troubleshooting/BlownMosfets.pdf‎

The wheel also rotates by hand quite freely while still connected to the controller, so I do not suspect a blown FET.

I've checked all the capacitors and they're fine, with their ESR's within spec. The multimeter shows that all grounds such as the throttle, hall sensors, CA, etc (including that of the battery) are connected as a common earth but from what I've read it shouldn't cause any issues. I suspect that battery pack voltage is somehow leaking to the hall sensors since I once got a nasty shock while touching a hall wire and the frame, and also when a hall wire burnt through, the voltage/heat was enough to melt a small channel into the side cover of the hub motor! 5V at <1A should not be able to do that kind of damage.

Any help is much appreciated! Thanks!

 

[amberwolf]

What blew the hall in the motor?

If it was a short to a phase wire, it could easily have blown something in the controller, either electronics between the MCU and the sensors (if any) or the MCU itself.

 

[TheThirdWheel]

What blew the hall in the motor?

At first I thought it was a short from the green hall wire to the hall negative. I saw evidence of the hall wires rubbing against the inside of the hub motor cover, exposing the bare copper and shorting through the motor cover, however the physical damage seems too much for such low voltage and current.
I suspect there is a short of phase to hall somewhere, but only intermittently. It can't be the motor because I've just rebuilt and tested it, and it works just fine with the el-cheapo controller.

I did more testing today, different batteries, and throttles, and all with the same result i.e. the motor does not even attempt to spin.
All hall wires connect to the controller just fine, as do all phase wires, however none connect to each other (well according to my multimeter anyway).

If it was a short to a phase wire, it could easily have blown something in the controller, either electronics between the MCU and the sensors (if any) or the MCU itself.

So there's a chance that something irreplaceable blew? :/ Bugger. Maybe it's time for a new controller :/ Just annoys me that a $175 piece of hardware just dies while operating well within it's limits.

 

[amberwolf]

Well, if there is a short between hall and phase wires, that's not within limits.

It'd be best if these things had protection against that, but I don't know of any typical ebike controllers that do. Maybe the Sevcon does. Possibly Lebowski's controller, dunno about Adapto's or any of the other startups/DIY types.

 

[TheThirdWheel]

The problem is, there seems to be some evidence of a phase-to-hall short, but I just can't find it anywhere in the system. I fear that if the short happens in the motor somewhere, it will simply cook a new controller too.

I agree that there should be some kind of protection against over-voltage on the hall lines, but you know, that costs a small amount of money

Perhaps sensorless is the way to go!

 

[Tench]

It looks like you are going to have to open the motor and leads again to check each cable's insulation.

So the Infineon didn't fail, it got blown!

 

[TheThirdWheel]

All checked, and all good. Physical inspection shows no breaches in the insulation of both phase and hall wires. The 3 phase wires interconnect as expected since they're linked at the wye, but none connect to the hall wires according to the multimeter.
Is it at all possible that battery pack voltage was somehow running through the frame, into the motor casing, and to the worn hall wires since the controller was bolted down onto the metal framework?
e.g. MOSFET-->FET Heatsink-->Controller case-->Frame-->Motor?

 

[TheThirdWheel]

Nope. Just checked the MOSFET metal tabs against the heatsink and there's no electrical connection between them. They are fully insulated from the heatsink via rubber/plastic rings under the mounting screws, and therefore the frame. So there goes that idea

 

[dnmun]

Hi guys,

I have a sensored Infineon 40A controller (12xIRFB4110), 36-72V connected to a Crystalyte X5304 and running at ~72V. It has just up and died without warning. The controller still powers up and activates the CA, but there seems to be no power going to the hub motor. A sensor got fried in the motor, and after replacing all 3 sensors, the motor still does absolutely nothing when connected to the controller when the throttle is applied.
I know that the motor should at least try and rotate, cog etc regardless of hall sensor and phase wire configuration. To make sure it was the controller that was at fault I jerry-rigged a cheap Chinese controller I got off eBay to the motor, connected the same throttle and battery pack, and it ran flawlessly (after figuring out the hall/phase wire colour coding).
So now my question is, what could possible be wrong with the Infineon controller? The MOSFETs are all fine according to the testing procedures here:

http://www.ebikes.ca/troubleshooting/BlownMosfets.pdf‎

The wheel also rotates by hand quite freely while still connected to the controller, so I do not suspect a blown FET.

I've checked all the capacitors and they're fine, with their ESR's within spec. The multimeter shows that all grounds such as the throttle, hall sensors, CA, etc (including that of the battery) are connected as a common earth but from what I've read it shouldn't cause any issues. I suspect that battery pack voltage is somehow leaking to the hall sensors since I once got a nasty shock while touching a hall wire and the frame, and also when a hall wire burnt through, the voltage/heat was enough to melt a small channel into the side cover of the hub motor! 5V at <1A should not be able to do that kind of damage.

Any help is much appreciated! Thanks!

no way to know what you did to test this since there is no detail of how you established that the hall sensors were burned up. or why you replaced all three if only one was bad.

but if you have full battery voltage inside the hub motor the only way it can get there is through the phase wire. the hi side mosfet is shorted and the battery voltage is going through the phase wire to a short to the motor.

 

[TheThirdWheel]

no way to know what you did to test this since there is no detail of how you established that the hall sensors were burned up. or why you replaced all three if only one was bad.

After reconnecting a burned hall wire I tested the output of the halls by connecting the sensor lead to the controller, and monitoring the voltage output between the hall negative and the signal lead whilst waving a powerful magnet salvaged from a computer hard disk close by. 2 out of 3 hall sensors worked fine, oscillating between ~0V and ~5V as the magnet passed by. However the one with the burned wire was stuck at ~5V no matter what.

The reason I replaced all three was because I accidentally destroyed the 2 good sensors while removing the epoxy resin while I was replacing the hall sensor wires with new ones. One sensor had a leg snap off, the other had the top half of it's case broken off when the screwdriver slipped as I was chiselling off epoxy :/

but if you have full battery voltage inside the hub motor the only way it can get there is through the phase wire. the hi side mosfet is shorted and the battery voltage is going through the phase wire to a short to the motor.

This is the strange part. I've tested and re-tested the motor phase and hall leads and there is no connectivity between any of them and the axle and/or motor case. The electric shock was felt when touching a hall wire on the controller side (while the sensor lead was disconnected from the motor) and the motor casing. Could there have been a short in the controller?