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Editorial Complex Optimization and Simulation in Power Systems

Abstract This work aims to predict the general performances of a pilot parabolic trough collector during transient periods. To do so, a one-dimensional thermal model has been developed. It has been validated with experimental results from two different experimental setups, in steady-state conditions, with a transmitted power maximum error of 3.4%. Since the model only predicts the collector's thermal behavior, the parabolic trough collector has been first optically qualified. Then, optical efficiencies were used as input for the model. Experimental results were obtained in steady-state conditions and compared to the model. Then, experimental and numerical results were compared during two period of time with varying inlet conditions (i.e. dynamic condition tests): the first one with stable conditions, and the other one with harsh conditions. The developed model showed a good capability of predicting the thermal behavior of the parabolic trough collector with unstable environment (DNI, mass flow, inlet temperature), with a 9.6% relative standard error in the worst case. As a conclusion, while previous studies only focused on steady-state conditions, it has been showed that this kind of model can be used to precisely predict the dynamic behavior of large power plants.

This paper deals the study of the lead-acid behavior and its modelling based on the Kinetic Battery Model. Results of experimental tests are used to realize the analysis and to estimate the model parameters. These last can serve for prediction and estimation of the battery lifetime according to the actual operating conditions.

The assessment of voltage stability margins is a promising direction for wide-area monitoring systems. Accurate monitoring architectures for long-term voltage instability are typically centralized and lack scalability, while completely decentralized approaches relying on local measurements tend towards inaccuracy. Here we present distributed linear algorithms for the online computation of voltage collapse sensitivity indices. The computations are collectively performed by processors embedded at each bus in the smart grid, using synchronized phasor measurements and communication of voltage phasors between neighboring buses. Our algorithms provably converge to the proper index values, as would be calculated using centralized information, but but do not require any central decision maker for coordination. Modifications of the algorithms to account for generator reactive power limits are discussed. We illustrate the effectiveness of our designs with a case study of the New England 39 bus system. 10 pages, submitted for publication

Abstract Building-based active envelopes play an important role to reduce active heating supplies. Several techniques are developed to enhance the energy performances of active building envelopes; meanwhile, numerous numerical and mathematical models are also developed to conduct the performance analysis of these techniques. In this paper, we propose a state-space model for solar active wall-based Phase Change Materials (PCM). The advantage of this method remains in its simplicity to provide details of internal nodes and input/output parameters. The low-cost calculation is a supplementary advantage versus a heavy numerical method. The proposed numerical model is applied for a multi-layer wall with PCM Wallboards (PCMW) embedded between indoor and outdoor environments. The results show the ability of the state-space model to estimate the thermal behavior of the system, as well as the thermal characteristics of embedding PCM in the internal face of the wall. It significantly contributes to stabilize the indoor temperature and to ensure the thermal comfort.

Abstract The elemental dissolution of Cu-Zn alloys was investigated as a function of Zn content ranging from 0 to 45 wt%. Atomic emission spectroelectrochemistry (AESEC) was utilized to directly monitor Cu2+ and Zn2+ release and oxide growth as function of time during potentiodynamic experiments. It was determined that Cu dissolution undergoes a simultaneous mechanism of Cu2O formation and Cu2+ release. The addition of Zn in Cu-Zn alloy does not measurably change the dissolution mechanism of Cu2+ and the rate of aqueous Cu2+ was only dependent on the potential. Zn dissolution was however blocked by the formation of a Cu(0) film which shifted the Zn dissolution in the anodic direction.

This paper presents the direct power control (DPC) of asymmetrical six-phase permanent magnet synchronous generator (A6PMSG) which supplied the isolated load via two PWM rectifiers. The study concerns the method of control by the converter (DPC). The proposed method is around two hysteresis controllers that enable the adjustment of active and reactive power. The research in this paper is verified by MATLAB SIMULINK software. It has been demonstrated through the simulation results that the proposed strategy can be an attractive and practical solution to multi-phase machines applications.

In order to know the origin of the noise generation when an impinging jet hit a specific geometry, an experimental setup was used allowing the generation of the flow and the adjustments of its parameters (such as Reynolds number, confinement, alignment, etc…). The vortex dynamics in case of a high acoustic level for two different Reynolds numbers Re = 5684 and Re = 6214 are considered here. Indeed, many configurations allow self-sustaining sound loop to take place in confined spaces between the nozzle and the impinged surface. This feedback loop optimizes the energy transfer between the aerodynamic field and the acoustic field and creates a source of noise that can become very noisy. Thus, to control these phenomena, it is necessary to understand the aero-acoustic coupling in such configurations. As a result, we measured the 2C kinematic instantaneous fields (vx, vy) of the flow by the technique of Particle Image Velocimetry (PIV) with a sampling rate of 1 KHz and the acoustic field is obtained using a B&K Microphone. For the two considered Reynold numbers, we can distinguish two patterns for the vortices travelling from the nozzle toward the plate of impact.