Line current three phase motor in six step commutation

[Trainee28]

Hello,

I have got a three phase motor connected in delta that is controlled in six step commutation. When I measure the line current of one of the phase under oscilloscope, I got something like this :

Can anyone tell me why the amplitude of the current isn't 3.1A and -3.1A? What I got here is 3.1A and -4.1A which is not symetrical.

 

[Hesch]

I'm worried about the spikes when the signal = -4A. Could be that it is trying to come up with -3.1A, but it cannot ( connection lost again ).

Bad soldering in your drive?