Electromagnetic interference in photovoltaic system and mitigation of conducted noise at DC side

This paper focuses on the electromagnetic interference (EMI) generated in a photovoltaic system. Noise caused by inverter has spread to the disturbance both conducted and radiated emissions. In addition, the EMI can be transferred from one mode to another mode; this means that conducted EMI can be transferred to radiated EMI and vice versa. Several emission patterns in such a system will be described to reveal the possible propagation paths of the EMI. To suppress the high-frequency disturbance, a passive EMI filter is added at the DC side of the solar inverter. The overall system is tested in various configurations: mainly with and without EMI filter, and with and without electrical load connected. Finally, the EMI testing results are compared with EMI standard to confirm the effectiveness and benefits of inserting a passive EMI filter in the studied photovoltaic system.