Have i by mistake turned my motor in to a controler killer?

[Trilska]

I would apriciate some help with identifying a potentia fault in the motor, or have i have just been unlucky with the controlers.

The motor for my kmx projekt is a Minimonster hub motor from John in Cr.
Projekt thread: http://endless-sphere.com/forums/viewtopic.php?f=28&t=50357
Motor sale thread:http://endless-sphere.com/forums/viewtopic.php?f=31&t=40859

I am starting to suspect that the motor causes to damage the controlers, not from exessive current draw, (this have happened with an unloaded motor feed less than 50w.)

Starting with the first one.
The controler that came along with it (a 50A sinewave unit), developed after a couple of hours an odd behavior. It would after aroud 10km start to cut power even with very modest throttle, (controler casing around 35C). Then accept a slow throttle input but only turn for about 5 revolutions. This behaviour happend aprox 3 times even with a cold system. After after a couple of runs it died completly. After this i acepted the loss and invested in a Sabvoton controler.

Sabvoton controler, SVMC072150.
Recived the controler wiered it up corectly stated hall initiation procedure via pc and the included software as instructed from the manual (motor rotating slowly to locate hall sensor spacing), motor rotated around 1/4 revolution and then "died", red led flashing very very weak and the 5V for sensor only sat now at 1,36V, and the serial pc comunication was dead. Accepted it as a faulty controler and conected sabvoton, did some basic faultsearching with guidence from sabvoton but with no result. So they shipped a new for free the same week on the condition that i sent the faulty one back to china.

The replacement sabvoton controler,
Same procedure, same result. Controler died during initiation procedure and 5V+ delivered after the test 1.6V. Will continue faultsearching with sabvoton tomorrow.

Worth mentioning is that the test have been preformed at a voltage of 76-75V (20s lipo), and 59V (via a powersuply).

This is what i know about the motor:
1. Worked flawlessly with stock controler, (untill it stoped to function properly).
2. There is no short circuit between the pfases, and pfases rotor or stator.
3. There is no short circuit between the hallsensors, 5V gnd and individual legs.
4. There is no short circuit between the hallsensors and the rotor or stator.
5. The hallsensors never draw more than 10mA combined.
6. The motor started up (unloaded) on a sensorless RC-ESC.

So do i have a potential fault in the motor or have i just been very unlucky with the controlers?
Thanks in advance //Trilska

Ps. I will do a writeup on my experience with sabvoton, as they sore far have been far from ideal but still promising Ds.

 

[Trilska]

Bump.

 

[Shenta]

oh godsh.... Sabvoton Controller are one of those china made rubbish, they don't even have proper english manual...
a good controller should detect and tells u where the problem is, maybe ur motor has a short circuit or fault hall sensor.

 

[John in CR]

Trilska,

I admit that I've done little testing on those little 12 fet sine wave controllers, but the motors are well tested. The only time I've had one not work is when I bumped the shifter rod, which put the motor between the high and low speeds. If yours is slipping between the two on its own, then you may want to have it spring loaded so the force of a spring keeps it in either position (similar to a spring on a kick stand).

I know you had some wire damage in shipment and you posted that there's no short, but what about either phase shorted with the axle, or with a hall wire? Those kinds of shorts can be tricky, especially halls, and not rear their head until a certain temp is reached.

In my experience controllers either work or they don't, so intermittent behavior would be new to me. Do the Sabvoton's handle 120° halls (I take it yours are spaced evenly around the stator like the other Mini's I've opened. They've been out of production for several years, but I assume all of the old stock I've sold for the factory are the same.

Did you try both controllers with the motor set on both high speed and low speed?

When you first had the motor running and up to 63kph, was everything running well at all speeds and loads? BTW, unless you loaded it down, like from a dead stop on a steep hill, I wouldn't be surprised at all if the controller never reached max current with the low gearing and load you run. I've yet to hit the 50A that Greentime says is the max current either, but again I haven't run them enough to say it won't. The mosfets are 4110's, so especially with sinus output, it should easily handle 50A, so effectively shortening the shut by 20-25% should be a non-issue.

Have you checked the actual LVC of the controller by reducing voltage until it won't work? What about a BMS on you battery, could that be cutting off the current? Have you checked controller temp (even if just with your hand) when it starts to cut off? I don't know where it's mounted, but if not getting a good cooling flow than could explain a thermal cutoff, since the motor obviously isn't getting close.

Overall, as long as there isn't a short, and the motor is definitely in high or low speed (could those contacts be corroded?) then the chances of the issue being the motor are remote. That doesn't mean the controllers are faulty though, since other issues listed above (and more) could make them or the battery cut power.

In the future, please ask me first, since some noob might send you on a wild goose chase. If together we come up with info to be shared or you have something I can't answer, then of course get any input you can find.

John

 

[John in CR]

oh godsh.... Sabvoton Controller are one of those china made rubbish, they don't even have proper english manual...
a good controller should detect and tells u where the problem is, maybe ur motor has a short circuit or fault hall sensor.

Meanwhile, China has tens of millions of EVs on the road dependably running every day. I'll take a bargain priced Chineses controller over a ridiculously priced controller made elsewhere any day of the week, especially since I can buy 2 and have 1 as backup and still save plenty of money.

Also, despite being off topic, unless you have an emoto built for racing, or some $20k or higher priced EV, then I challenge you to a race with me using my street legal electric bicycle powered by a Chinese motor and controllers to a race. Put your money where your mouth is and prove that Chinese controllers are rubbish.