Electromagnetic compatibility characterisation of the DC side in a low power photovoltaic plant

This paper presents an analysis of the electromagnetic compatibility of low power photovoltaic (PV) systems specially focused on the role of DC line. The cables connecting the PV panels to the inverter may be a source of electromagnetic emissions generated by the commutations of power electronic devices; these emissions may become radiated disturbances due to the length of the cables, so possible interference occurs even in a range below 30 MHz. Moreover the DC cables behave as a receiving antenna and the induced radio frequency (RF) currents flow via a capacitive parasitic coupling into the ground connection. Through an experimental investigation the prevalent involved electromagnetic phenomena have been pointed out. General guidelines for the high frequency modelling of the system are also addressed.