62 research outputs found

    Comparing ADALINE and IRPT methods based on shunt active power filters

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    In this paper, a shunt active filter based on adaptive linear neuron (ADALINE) method is analyzed. The ADALINE that is used here as the harmonic extraction method is implemented with the measurement of load current under the direct and indirect techniques. The response of method to the loading conditions is compared to that of the instantaneous reactive power theory (IRPT) method. TMS320F2812 digital signal processor (DSP) is employed as a central processing unit in experimental works. Copyright (C) 2010 John Wiley & Sons, Ltd

    Evaluation of reference current extraction methods for DSP implementation in active power filters

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    Generation of current references constitutes an important part in the control of active power filters (APFs) used in power system, since any inaccuracy in reference currents yields to incorrect compensation. In this paper, harmonic detection methods for generating reference currents have been evaluated on the basis of three-phase balanced and unbalanced load currents processed in the digital signal processor (DSP). The advantages and disadvantages of several methods found in the literature have been discussed on the basis of simulation results. Three of these methods have been programmed in the TMS320F2812 digital signal processor (DSP) unit and their performances are evaluated from the viewpoint of practical considerations. Finally, instantaneous reactive power method to estimate the APF reference currents is implemented and its practical results obtained under balanced and unbalanced loads are given. (C) 2009 Elsevier B.V. All rights reserved

    Design and PSPICE analysis of a grid connected multilevel converter with reduced number of switches

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    In this paper, PSPICE analysis and design of grid connected multilevel converter will be presented. This converter has all the features of H-bridge structure, while it has six semiconductor switches and drivers to produce five-level output voltage. Reduction of IGBTs and drivers decreases the converter losses and system cost. The PSPICE analysis is used to predict the spikes on the collector emitter voltages and to design the snubber circuit. The converter is implemented in the three-phase Y-connected Statcom by using a digital control algorithm realized in floating point DSP TMS28335

    Neutrophil-to-lymphocyte ratio, insulin resistance, and endothelial dysfunction in patients with autosomal dominant polycystic kidney disease.

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    Endothelial dysfunction (ED), insulin resistance (IR), and inflammation are risk factors for increased cardiovascular morbidity and mortality in autosomal dominant polycystic kidney disease (ADPKD). ADPKD patients may have increased carotid intima-media thickness (CIMT) and decreased coronary flow velocity reserve (CFVR). The neutrophil-to-lymphocyte ratio (NLR) was introduced as a marker to determine inflammation in various disorders. We aimed to investigate the relationship between NLR and IR, CFVR, CIMT, and the left ventricular mass index (LVMI) in normotensive ADPKD patients. Twentynine ADPKD patients (age 38.8 ± 10.2 years; 8 men and 21 women) and 19 healthy controls (age 33.8 ± 7.4 years; 8 men and 11 women) were included in this cross-sectional study. CFVR was calculated with echocardiography as the ratio of hyperemic to baseline diastolic peak coronary flow velocities. CIMT was measured in the distal common carotid artery by using a 10-MHz linear echocardiography probe. HOMA-IR was calculated NLR was calculated as the ratio of the neutrophil and lymphocyte counts. Age, sex, body mass index, and levels of glucose, creatinine, low-density lipoprotein (LDL)-cholesterol, high-density lipoprotein (HDL)-cholesterol, triglycerides, C-reactive protein (CRP), microalbuminuria, and creatinine clearance were similar between ADPKD patients and healthy subjects. NLR, CIMT, LVMI, and HOMA-IR were significantly higher and CFVR values were significantly lower in patients with ADPKD compared to that in healthy subjects. NLR showed positive correlation with CIMT, HOMA, insulin, glucose, and HDL cholesterol levels, while it was inversely correlated with CFVR and albumin level in all subjects. In patients with ADPKD, NLR showed positive correlation with HDL cholesterol level and inverse correlation with LVMI and albumin level. NLR that was found to be increased in patients with ADPKD may be a readily available marker of inflammation and ED
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