Contribution à l’étude des moyens techniques visant à alléger les contraintes imposées au réseau public à basse tension

Download or read book Contribution à l’étude des moyens techniques visant à alléger les contraintes imposées au réseau public à basse tension written by Rafael Ordonez Flores and published by . This book was released on 2007 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work consists of grouping together a three-phase Active Filter and an “uninterruptible power supply” into a single converter. This converter is then capable of reducing electromagnetic perturbations from the main AC supply and also of acting as a Backup Supply. It can adapt itself to any linear or non linear load, balanced or unbalanced. The converter is connected in parallel with the electric grid to impose optimal waveform currents on the main AC supply or to replace it. To implement the AF, the principal task has been to determine the optimal waveform of the supply currents. The objective is to obtain a maximal Power Factor. Since the supply voltages are distorted, the compensation method of "non active" power is used for reaching the maximal PF. The AF then supplies the non active power that the load absorbs. To mitigate failures from the main AC supply, a battery is connected to AF. A solution which allows minimization of the batteries encumbrance is proposed: it sets up a supplementary dc/dc converter which acts as buck/boost converter. The Active Filter – Backup Supply system works then in one of two modes according to the availability of the AC supply: 1) AC supply available, FACH (French name) mode: the AF compensates for the non active power and supplies the energy necessary for the charger (buck converter) to recharge the battery; 2) AC supply unavailable, OSE (French name) mode: the BS supplies sinusoidal voltages to load from the boost converter – battery group. The AF was validated by a 1.5kVA experimental model and the global AF-BS system by simulation.