LabVIEW Electrical Power Toolkit

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Anomaly on intermitent loss of current waveforms

While experimenting with the current transfromer settings we noticed that the EPS software would go to a strange state. This anomally was also observed while usig a battery backed current transformer that experienced a low battery. The current waveforms replace the voltage waveforms on the display (RT-Controller) and the current diplsay does to 60A on L1 and 0A on L2 and L3.

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Here is a screen snap shot demonstrating the anomaly.

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I don't think your observation of anomaly is relevant with transformer or other hardware.

 

My guess is 512 samples per cycle. As defined in IEC 61000-4-30, all power quality parameters should be updated every 10 cycles (50 Hz) or 12 cycles (60 Hz), which means all the computation, data logging or data communication in each iteration must be finished within 10/12 cycles, which amounts to around 200ms. If specifying 512 samples per cycle in a low-end CompactRIO controller with too many analysis, the elapsed time of each iteration would exceed 200ms, which makes the DMA FIFO full and the data from FIFO would be messy.

 

You can wire an indicator to the "elements remaining" of ep_Read from FIFO.vi to observe whether it keeps increasing.

 

 

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Can any one please explain me how to set Sample time in Energy block.
kindly attach .vi file calculating energy from simple simulated sine wave.

It will be great favour 

Thakin you in anticipation

 

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