In this paper we present a new approach of MRAS based on current model only. This technique aims to offsets compensating and solving problems of ordinary MRAS in low speed. Also this new approach allows us to estimate the components of the rotor flux and the rotor speed without using the voltage model. The results of the simulation and the experimental results are presented and show the effectiveness of the proposed technique.

In this paper, an efficient and fast MPPT power control of photovoltaic systems based on backstepping approach is presented. The proposed control scheme consists of two cascade loops; in the first loop, the auto-scaling variable step-size perturb and observe MPPT technique estimates the reference voltage of all electrical load values. The robust backstepping controller has been adopted to remove steady state oscillations in the second loop. Further, the performance of proposed control system has been analyzed through dSPACE DS-1104 experimental validation with Isofoton photovoltaic module under real climatic conditions at Biskra (Algeria) region. The results obtained by the used controller averred a good improvement.

BLEVE is one of major accidents observed in gas industry causing severe damage to people and environment. Its effects are manifested in three ways: shock wave propagation, fireball radiation and fragments projection. To assess these effects, risk decision-makers often use Quantitative Risk Analysis (QRA). In most cases, QRA data are obtained from empirical correlations. However, these correlations are not very satisfactory because they generally overestimate BLEVE effects and do not take into account geometry effects. In order to overcome the limitations of these empirical approaches, CFD modeling appears as a powerful tool able to provide more accurate data to better realize QRA. In this paper, the objective is to develop a CFD methodology in order to predict BLEVE thermal effects. Numerical simulations are carried out using the CFD code FDS. A sensitivity analysis of numerical models is performed in order to choose the right parameters allowing to model the fireball dynamics. The models retained are based on a single-step combustion using EDC model coupled with a LES turbulence model. Predictions show good agreement in comparison with results issued from three large-scale experiments. Furthermore, a case study on a propane accumulator in an Algerian gas processing unit is carried out.