In this blog post i will explain how i solved a problem while simulating a partial shading issue in PSIM. I was trying to simulate a two panel scenario with one panel shaded. However, i was not getting the result. In fact the following dialog box was shown upon the completion of simulation.

Warning : ...... files contains missing or invalid points

The situation in MATLAB was the same. No curve appeared on the XY plotter and the diplay block showed NaN. The problem was solved by following the below mentioned steps.

1. Connect a small capacitor (1 microfarad ) in parallel with each PV module.
2. Do not forget to add bypass diode.