Distorted waveforms at AOs of HIL 101 outputs in DAB ultracore example

Question

Hello Typhoon community,

I am testing DAB at 100kHz signals, the waveforms at the analog ports AOs are distorted. At 10 KHz its fine. The scaling done is apt. Testing is done for rated power of 500W and Vin 300V Vout at 100 V and expected output current 5 A. So I don't see any reason scaling should cause distortion. Oscilloscope settings are Coupling DC, Impedance 1Mhz. It's a new oscilloscope. 

Kindly help in this regard. 

Answer 1

Hi Uddhav,

The update rate of the analog output update rate is equal to the simulation time step (the "large one", used by the SPC, which is probably around 300-500ns). It is not as fast as the UltraCore step of 4.5ns on HIL101. This is a fundamental limitation in the hardware. In your case it looks as if the analog outputs are updated every 500ns. If you reduce your time step, you will have a better update rate, but best case scenario is 200--250ns, which will not yield fully smooth waveforms at 100kHz.

Is your controller directly sensing the transformer current in order to derive the control?

Best,
Jovan