Hybrid power source with battery/supercapacitors for uninterruptible power supply (UPS)
Résumé
In this paper, a power sharing system between the battery and the supercapacitors in a 500 kVA rated uninterruptible power supply is presented. Compared to typical batteries, the supercapacitors can be charged and discharged very rapidly and can supply high current which are important characteristics of an UPS. Supercapacitors are then added as higher energy storage to overcome the full load power during short time grid failures and to boost peak power during backup time of few minutes. The high power demands applied to the battery are then smoothed by the use of a low-pass filter. The potential reduction of the battery stresses is subsequently studied. Mathematical models for battery and supercapacitors pack are set up and validated through experimental and manufacturer data. The UPS waveforms obtained by simulation with MATLAB/SIMULINK are presented and analyzed.