Premo Group offers a wide range of EMC filters for UPS, with various ranges of current, voltage and filter stages, designed and built according to UL1283 and EN60939-2 standards. Included is the PFT series, a three-phase with neutral filter, specially designed for three-phase UPS without transformer. PFT Series offers currents from 3 to 150A and working voltage up to 520Vac, 50/60Hz, providing high common mode attenuation and differential, as well as low leakage current. This family of filters offers a compact design and is available in different versions, with fast-on connection, screws or terminal blocks.
These filters have been developed to fulfill the specific needs of this application in terms of attenuation levels, volume, weight, connections, etc. Premo continuously improves its EMC filter designs, in collaboration with development centers, universities, suppliers and customers, innovating in new technologies such as IPEM and introducing new magnetic materials (nanomaterials, new alloys, etc.) to achieve optimum results in operation mode, reliability, size and efficiency.
Current UPS store energy in batteries in DC mode. When necessary, supply such power in AC mode, thanks to a DC/AC converter. This converter works in switch-mode and generates electromagnetic noise, both conducted and radiated, which affects to its operation and the nearby electronic devices. This electromagnetic emission has to meet the limits established by the standard applicable, and the environment in which it is supposed to work, as well as to ensure optimal functionality of the UPS. Typical standard are EMC IEC 62040-2 and EN 50091-2.
One EMC test is for conducted emissions. In this test the noise in the power is measured, using a LISN. The measurement frequency is 150 kHz to 30 MHz and the maximum limit allowed depends on the applicable standard and the environment where they are going to work, domestic or industrial.