I have a 700hp Powerflex 700S VFD for which I am trying to setup for driving a 480V 350hp kiln drive motor. I am selecting the FOC mode for the drives control mode and am having issues with the autotune procdure for setting up the FOC mode.
The first strange result appears when we perform the static tune. The results of the static tune display the calculated Stator Inductance, Stator Resistance, and Leakage Inductance. The drive says that these results are displayed in percentage of the rated motor impdecance. The results for the stator Inductance show a value of aprox 98% or so while the stator resistance value result only shows about .05%. Shouldn't the stator resistance value be close to 100% as is the stator incudcance since these values are being compared to the motors rated impedance and therefore the calculated should match the rated? Or is it comparing these calculated values the motor "total impedance" and therefore the motors impedance is made up primarily of stator inductance and has very little stator impedance. (I may have answered my own question) So then it would make sense that the results show a high percentage for the stator inductance and a low value for the stator impedance since it is looking at the total motor rated impedance. How does the drive know what the motors "rated impedance" is for these comparison calculated values?
The second issue is when we try to run the rotational tune on the drive. We are running the rotational tune with the motor uncoupled from the kiln load. When we run the rotational tune once we get calculated results, but when we run the test a second time to see if we get the same results the drive trips on a DC Bus overvoltage. At that point we can cycle power on the drive which clears the autotune information and we can run the rotational autotune procedure again with calculated results. However once the rotational test is performed a second time in a row the drive again trips on DC bus overvoltage.
What could be causing this DC Bus Overvoltage when running this rotational test a second time in a row?
Is a second test really necessary to verify results? The tech says it is important to make sure the results are repeatable. But what happens if the drive is put back into operation with the results just calculated from the one test? Could there be an issue with the motor?
We are having issues with this drive and motor producing their rated 250% torque during starting. This 250% torque equates to 1200A on the motor but for some reason sometimes the drive is limiting the current to the motor, the motor is not producing the required torque and stalling the load and the drive is tripping. We are hoping that the Autotune with the FOC mode will help wit this issue. Does anyone else have any other ideas?
The first strange result appears when we perform the static tune. The results of the static tune display the calculated Stator Inductance, Stator Resistance, and Leakage Inductance. The drive says that these results are displayed in percentage of the rated motor impdecance. The results for the stator Inductance show a value of aprox 98% or so while the stator resistance value result only shows about .05%. Shouldn't the stator resistance value be close to 100% as is the stator incudcance since these values are being compared to the motors rated impedance and therefore the calculated should match the rated? Or is it comparing these calculated values the motor "total impedance" and therefore the motors impedance is made up primarily of stator inductance and has very little stator impedance. (I may have answered my own question) So then it would make sense that the results show a high percentage for the stator inductance and a low value for the stator impedance since it is looking at the total motor rated impedance. How does the drive know what the motors "rated impedance" is for these comparison calculated values?
The second issue is when we try to run the rotational tune on the drive. We are running the rotational tune with the motor uncoupled from the kiln load. When we run the rotational tune once we get calculated results, but when we run the test a second time to see if we get the same results the drive trips on a DC Bus overvoltage. At that point we can cycle power on the drive which clears the autotune information and we can run the rotational autotune procedure again with calculated results. However once the rotational test is performed a second time in a row the drive again trips on DC bus overvoltage.
What could be causing this DC Bus Overvoltage when running this rotational test a second time in a row?
Is a second test really necessary to verify results? The tech says it is important to make sure the results are repeatable. But what happens if the drive is put back into operation with the results just calculated from the one test? Could there be an issue with the motor?
We are having issues with this drive and motor producing their rated 250% torque during starting. This 250% torque equates to 1200A on the motor but for some reason sometimes the drive is limiting the current to the motor, the motor is not producing the required torque and stalling the load and the drive is tripping. We are hoping that the Autotune with the FOC mode will help wit this issue. Does anyone else have any other ideas?