Two techniques in comparison for UPS's low generation of harmonic currents in the network

The solutions to the problem of sinusoidal wave distortion caused by voltage and current harmonics are described for two families of currently mass-produced uninterruptible power supply (UPS) systems. The first UPS range is three-phase from 10 to 300 kVA, realized by a fully controlled thyristor bridge where the generated harmonics distortion reduction is obtained by means of standard filters. The second range of products, manufactured for telecommunication, is single-phase up to 20 kVA and is realized by a high-current frequency chopper at sinusoidal current. This solution yields a distortion in the range of 3% and a PF of 0.99.<
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