The new Schaffner FN 2200 DC EMC/EMI filter series, available from Westek Electronics for photovoltaic panels, is designed to prevent conducted RF from the inverter reducing the potential for radiated emission with PV panels and wiring acting as antennas.
Solar energy inverters generally have high power levels in the range of 10k to 100kHz and the high power dc and ac wiring can be effective antennas for radiation into free space. Additional noise is generated due to reverse recovery of diodes and artifacts of switching. This can generate more power at high frequencies and are an alternative to the commutation process.
The Schaffner FN 2200 DC EMC/EMI filter series is installed between the PV panel and inverter operational blocks. The filters are suitable for DC voltages up to 1200 volts and are available in current ratings varying from 25 amps to 1500 amps and conform to IEC/EN 60939 as well as UL 1283 and CSA 22.2 (No 8, 1986). To prevent erroneous installation, the PV side and inverter side of the filters are distinguished because of the asymmetrical construction of the filter housing.
The Schaffner FN 2200 DC EMC/EMI filter series meet the EMC requirements of EN 61000-6-5/4. The Schaffner FN 2200 DC EMC/EMI filter series is designed to filter out differential as well as common mode noises. Ringing at high frequencies caused by switching transients exciting parasitic resonances in the power circuits is a source of differential (symmetrical) noise. The Schaffner FN 2200 DC EMC/EMI filter series is designed for low power loss, for example, the 500 kilowatt model has a power loss of 45 watts.