Cuts of erroneous data
During a real data acquisition, the measured data often include erroneous measurements which correspond either to deficiencies in the measurement equipment, or to break-downs or disturbances in the PV-system itself. These non-significant values should be eliminated from the calculation of the comparison estimators, from the monthly accumulations, or even eliminated from graphs.
PVsyst offers several means aiming to "mark" data for elimination:
- General criteria can be applied to hourly or daily comparison graphs: limits on the measured value, on the simulated value, on their difference or their ratio. Whenever possible, the graph explicitly traces the limits of the criterion.
- On comparison graphs, isolated aberrant points can be individually eliminated by a simple click of the left button of the mouse (or, contrarily, restored by a right click).
- On measured, single hourly or daily data can be eliminated with the mouse.
The eliminations performed on a comparison graph are carried over to all the other graphs of the calculated version. The eliminations of values in an hourly graph will therefore cause the elimination of the whole corresponding day on a daily graph.
The eliminations performed on graphs can be saved on the file of the calculated variant (".CMi"), to be automatically displayed again in a later session.
Further, the indications of eliminations of a calculated version can also be carried over to the original file of measured data (.DAM file). This allows, during another simulation, to reuse these break-down indicators as conditions for accumulation of new comparisons. This proves to be particularly useful for the elaboration of monthly comparisons graphs, where the elimination of break-down days is primordial.