I am a PhD student and I made some measurements on a hydropower test rig from an laboratory. It was equipped with a Siemens DC Generator and was controlled through Simoreg6RA70. Some guys from Siemens came and work and implemented the procedure for controlling the torque of the turbine keeping the active power constant. I varied the torque like a sinusoid with different frequencies and amplitudes. During this time I recorded the torque and the angular speed signals. My problem is that after filtering the signals and keeping only the component of the signal given by the torque variation I obtain a phase shift between the signal for sinusoid with 1 Hz about 20° and for 2 Hz about 160° and for 3 Hz about 19°. I cannot explain this variation.

Does anybody can explain?

 

Fortunately I'm not very good at mind reading - It's not clear what you are doing or trying to achieve.

We take it there is a variable speed drive (vsd); Simoreg6RA70 appears to be a software component on a vsd; and somewhere there is a turbine within a water related test rig.

That apart - why are you trying vary torque on a vsd by oscillating commands? and would you not expect delays in speed variation??

 

>We take it there is a variable speed drive (vsd); Simoreg6RA70
> appears to be a software component on a vsd; and somewhere there is
> a turbine within a water related test rig.
>
> That apart - why are you trying vary torque on a vsd by oscillating
> commands? and would you not expect delays in speed variation??

The test rig was equipped with a hydraulic turbine connected to a DC generator controlled through Simoreg. I varied the torque because I wanted to create an oscillating regime in the turbine. I expected that delay but I didn't expected that big difference from 1 Hz to 2 Hz.