three phase current unbalance in v/f control mode

dear expert 

i have motor module i change p 1300 =0 v/f  the problem that the three phase current is unbalance also the three phase voltage is unequal  three phase current is 29A 22 A 27 A the full load current is 40 A the sound of motor also is very bad and high 

this motor module when i change the the control mode to vector control it give motor stalled f7902  

so i change the control mode to v/f control mode 

this motor module work for one year in vector and suddenly this happen 

neklawy 88

dear expert 

i have motor module i change p 1300 =0 v/f  the problem that the three phase current is unbalance also the three phase voltage is unequal  three phase current is 29A 22 A 27 A the full load current is 40 A the sound of motor also is very bad and high 

this motor module when i change the the control mode to vector control it give motor stalled f7902  

so i change the control mode to v/f control mode 

this motor module work for one year in vector and suddenly this happen 

When the motor run in vector control mode, does it has speed sensor or run as sensorless vector? If with sensor, please check the sensor for its output signals, coupling, cable tec. etc. If the motor is run with sensorless vector, check the motor for any mechanical issue inside it or conduct tunning once again. 

Measuring Pulse Width Modulated supplies require a device optimized for this, a Hall effect device will accept this for measurement. Using standard instruments will typically indicate as you have seen.

Testing motors for use with PWM supplies is is also uncertain, as the PWM supply places stress on the motor windings, specifically between windings, 'corona discharge' being the initial failure, from the high  Voltages created by PWM. It is typical to test the insulation to the frame, with an insulation test, this is looking in the wrong place for motor failure. Failure to ground happens some time after the motor has suffered interwinding insulation breakdown.

The most reliable assessment is found using a 'Hi Pot' tester, this can evaluate the electrical charge of each individual coil, at stepped Voltages ranging to about 2kV.

This is 'Hi Pot' test is most valuable for borehole pumps, testing in situ; when the last thing you want to do is pull the thing up for a suspected failure.

My money will be on the motor if that helps here.

Tractor

When the motor run in vector control mode, does it has speed sensor or run as sensorless vector? If with sensor, please check the sensor for its output signals, coupling, cable tec. etc. If the motor is run with sensor less vector, check the motor for any mechanical issue inside it or conduct tunning once again.

my answer 

\when it was vector is was  encoder less  speed control p1300=20 

when i use another motor module it work good in vector control encoder less  speed control p1300=20 so the mechanical system and the motor is ok

Looks like you have found the problem, change the motor module, or power unit.

Tractor