Hello everyone! Firstly my setup is:

I'm trying to use the torque control with enconder in a induction motor that should be work as load for another machine.

I configured the basics for torque control in software and initally I putted 0% as torque reference, however when a turned on the inverter , the inverter applies a dc current about 40A  through the stator, for example, Is = 10A, Isb = 30A e Isc =-40A (Isa+Isb+Isc =0), even motor at standstill.

That applied current is generating a  resistance torque even with 0% of torque reference, thus the rotor is harder to spin. I think as the torque reference is null, that torque should not exists, the stator current should be 0A and the rotor should be "freer" to spin, right?

I would like to know if that issues is normal and/or how I can configure the inverter to solve that issue.

I attached some pictures. The fist one is he current through each motor phase (I measured once at ime, because i had one current probe) and the second one is the current at one phase and the speed from analog output port.

Best regards

 Hi esio eloi,

Check out the post to solve the torque control issues here 

Monitoring and limit of the g120 parameter help to analysis the issue. 

Thanks

esio.eloi

Hello everyone! Firstly my setup is:

SINAMIC G120 - Control Unit CU250S-2 USS, SINAMICS Power Module 250 and I´m use the TIA V14 to configure the control.

I'm trying to use the torque control with enconder in a induction motor that should be work as load for another machine.

I configured the basics for torque control in software and initally I putted 0% as torque reference, however when a turned on the inverter , the inverter applies a dc current about 40A  through the stator, for example, Is = 10A, Isb = 30A e Isc =-40A (Isa+Isb+Isc =0), even motor at standstill.

That applied current is generating a  resistance torque even with 0% of torque reference, thus the rotor is harder to spin. I think as the torque reference is null, that torque should not exists, the stator current should be 0A and the rotor should be "freer" to spin, right?

I would like to know if that issues is normal and/or how I can configure the inverter to solve that issue.

I attached some pictures. The fist one is he current through each motor phase (I measured once at ime, because i had one current probe) and the second one is the current at one phase and the speed from analog output port.

Best regards