Magnetic Modelling of Synchronous Reluctance and Internal Permanent Magnet Motors Using Radial Basis Function Networks

The general trend toward more intelligent energy-aware ac drives is driving the development of new motor topologies and advanced model-based control techniques. Among the candidates, pure reluctance and anisotropic permanent magnet motors are gaining popularity, despite their complex structure. The availability of accurate mathematical models that describe these motors is essential to the design of any model-based advanced control. This paper focuses on the relations between currents and flux linkages, which are obtained through innovative radial basis function neural networks. These special drive-oriented neural networks take as inputs the motor voltages and currents, returning as output the motor flux linkages, inclusive of any nonlinearity and cross-coupling effect. The theoretical foundations of the radial basis function networks, the design hints, and a commented series of experimental results on a real laboratory prototype are included in this paper. The simple structure of the neural network fits for implementation on standard drives. The online training and tracking will be the next steps in field programmable gate array based control systems

Inhibition of Pseudomonas aeruginosa secreted virulence factors reduces lung inflammation in CF mice

Cystic fibrosis (CF) lung infection is a complex condition where opportunistic pathogens and defective immune system cooperate in developing a constant cycle of infection and inflammation. The major pathogen, Pseudomonas aeruginosa, secretes a multitude of virulence factors involved in host immune response and lung tissue damage. In this study, we examined the possible anti-inflammatory effects of molecules inhibiting P. aeruginosa virulence factors

Impact of MIF Gene Promoter Polymorphism on F508del Cystic Fibrosis Patients

Macrophage migration Inhibitory Factor (MIF) is a pro-inflammatory cytokine sustaining the acute response to gram-negative bacteria and a regulatory role for MIF in Cystic Fibrosis has been suggested by the presence of a functional, polymorphic, four-nucleotide repeat in this gene's promoter at position -794, with the 5-repeat allele displaying lower promoter activity. We aimed at assessing the association of this polymorphism with disease severity in a group of Cystic Fibrosis patients homozygous for F508del CFTR gene mutation. Genotype frequencies were determined in 189 Cystic Fibrosis and 134 control subjects; key clinical features of patients were recorded and compared among homozygous 5-allele patients and the other MIF genotypes. Patients homozygous for the 5-repeat allele of MIF promoter displayed a slower rate of lung function decline (p\u200a=\u200a0.027) at multivariate survival analysis. Multiple regression analysis on age-normalized respiratory volume showed no association of the homozygous 5-repeat genotype with lung function under stable conditions and no correlation with P.aeruginosa chronic colonization. Therefore, only the Homozygous 5-repeat genotype at MIF -794 is associated with milder disease in F508del Cystic Fibrosis patients

Robustness Analysis of Long-Horizon Direct Model Predictive Control: Permanent Magnet Synchronous Motor Drives

Model predictive control (MPC) lacks an integrating element. Thus, parameter mismatches can deteriorate its steady-state performance. To address this issue and enhance the robustness of MPC, analternative formulation of the prediction model is discussed in this paper. This model introduces an integrator to the optimization problem without increasing its size and consequently its computational complexity. An in-depth analysis of the effect of parameter mismatches on the control performance is performed when both the conventional and the proposed prediction model are used. Specifically, the aforementioned analysis is carried out for a range of switching frequencies as well as prediction horizon lengths, while a permanent magnet synchronous motor (PMSM) drive is used as a case study

Sensorless Drive for Salient Synchronous Motors based on Direct Fitting of Elliptical-Shape High-Frequency Currents

The paper deals with a position sensorless control for synchronous motor drive with an ease tuning procedure and a reduced number of tunable parameters. The rotating high frequency (HF) signals injection is implemented and the elliptical shape of the HF induced current trace is fitted by means of the least square (LS) algorithm. The ellipse tilt is related to the rotor position and the latter is estimated by processing the fitted coefficients of the ellipse mathematical equation. The proposed LS algorithm processes the measured currents, without the need to filter them as occurs in conventional injection methods. Furthermore, no motor parameters are required to tune the proposed rotor position observer. The method was validated throughout several experimental tests performed on an interior permanent magnet (IPM) synchronous motor

Estimation of hydraulic conductivity using the slug test method in a shallow aquifer in the venetian plain (NE, Italy)

none3The slug test offers a fast and inexpensive field method of obtaining localized hydraulic conductivity values. In this paper, we applied this procedure in a ‘fontanili’ zone located in the middle Venetian Plain (Villaverla, VI). In this site, 34 piezometers are present in a small area of 1.5 ha, which intercepts a shallow unconfined aquifer. The experimental data, obtained by 59 slug tests, were processed with three different methods of analysis: Hvorslev, Bouwer-Rice and KGS, to obtain a permeability characterization of the area and identify the real differences between the considered solutions. Two slug tests were also analyzed using a three-dimensional finite difference groundwater flow model. By comparing the different methods used in the same piezometer, we obtained highly similar values of permeability, while the numerical simulation of slug tests suggests that KGS is the best method for estimating hydraulic conductivity. At the same time, we can identify a considerable heterogeneity in the area of investigation; indeed, the slug test estimates of hydraulic conductivity (K) range over three orders of magnitude (from 2.6E- 06 to 3.8E-03 m/s). This wide range of values confirms the high stratigraphic heterogeneity also observed during the coring.noneFabbri P.; Ortombina M.; Piccinini L.Fabbri, Paolo; Ortombina, M.; Piccinini, Leonard