V/F control of Three Phase Induction Motor Drive with Different PWM Techniques

This paper presents a  v/f control of induction motor with different pulse width modulation ( PWM) techniques as sine triangle pulse width modulation ( SPWM), Third-harmonic  pulse width modulation (THPWM) and  Space vector pulse width modulation(SVPWM) using MATLAB SIMULINK. Induction motor modeled in the synchronous q-d reference frame. The performance of IM with full load torque is compared using these techniques for THD, harmonics spectra, utilization of dc supply voltage, fundamental peak of the output voltage and motor speed. The dynamic performance of IM using SVPWM under reference speed and load torque variations is studied also. The results show that the SVPWM is the efficient one because it’s superior performance characteristics. The operation of IM with v/f method for closed loop system is enhancement when SVPWM technique is applied. Keywords: Space vector modulation, SPWM, V/f control, Harmonic injection

MPPT Based on Power Mapping and Frequency Derivative

This article presents a method for harmonic mitigation and maximum power point tracking for a variable-speed grid-connected  wind turbine. The wind energy conversion system consists of a permanent magnet synchronous generator driven by variable-speed wind turbine. The output of the permanent magnet synchronous generator is connected to a single-switch three-phase boost rectifier to generate DC voltage, which feeds a current-controlled inverter to interface the system with the electric utility. The single-switch three-phase boost rectifier is an active power factor correction technique to maintain the power factor at the permanent magnet synchronous generator side to nearly unity and mitigate the permanent magnet synchronous generator current harmonics. To mitigate inverter output current and voltage harmonics, an LCL filter has been used. Acomplete analysis of the harmonic content has been done everywhere in the system. The results show that the proposed maximum power point tracking control strategy succeeded to track the maximum wind power irrespective of the wind speed. This strategy in presence of an LCL filter achieved harmonic mitigation at the permanent magnet synchronous generator and inverter output sides. Keywords: variable-speed wind turbine ; permanent magnet synchronous generator ; maximum power point tracking ; harmonic mitigation ; active power filter.

Errors Analysis in Distance Relay Readings with Presence of FACTS Devices

This  paper  presents studying the  performance of  distance impedance relay with the presence of  FACTS devices .Also  the measured  impedance  at   the  relaying  point  in  the  presence  of  series FACTS device SSSC , and  shunt FACTS device called STATCOM are obtained. A detailed  model of both SSSC and STATCOM  is  introduced  and  then  the  faulty  system is studied analytically , where  the  errors in the measured  impedance of distance impedance relay   are  introduced as a result of the presence of  series  and  shunt  FACTS  devices. The analysis results show the effect of impacting the FACTS devices location, the values of inserted SSSC and STATCOM voltages (operational conditions) and also the fault resistance values. Keywords: Distance Relay, FACTS, STATCOM, SSSC

Analysis of Wind Turbine Driven Permanent Magnet Synchronous Generator under Different Loading Conditions

This paper proposes the configuration of a Wind Turbine generating system equipped with Permanent Magnet Synchronous Generator (PMSG). There are different types of synchronous generators, but the PMSG is chosen which has better performance due to higher efficiency and less maintenance. Since it can be used without a gearbox also implies a reduction of the weight of the nacelle and a reduction of costs. The model includes a wind turbine model, drive train model and PMSG model. The equations that explain their behavior have been introduced. The generator model is established in the d-q synchronous rotating reference frame. The proposed Wind Turbine Generator System (WTGS) has been implemented in MATLAB/SIMULINK software. The PMSG is operating in stand-alone which is loaded with different types of loads. The simulation results indicate the ability of wind driven PMSG to operate over wide range of operating conditions at different loading conditions and show effect of different load types in operation. Keywords: Permanent Magnet Synchronous Generator (PMSG), Wind Turbine, Wind Energy and WTGS MATLAB/SIMULINK

L’art de regular les emocions. Un projecte d’educació emocional a una aula de 1º de Primària

Treball Final de Grau en Mestre o Mestra d'Educació Primària. Codi: MP1040. Curs acadèmic: 2019/2020L’educació emocional resulta primordial per a potenciar l’adquisició de les competències emocionals com a element essencial per al desenvolupament de la personalitat i de les capacitats de l’alumnat. És fonamental treballar a les aules l’educació emocional transversalment per a aconseguir una educació integral on es desenrotllen completament totes les aptituds de la persona. Per això, en aquest treball final de grau, a part de recollir una introducció teòrica on s’exposen algunes teories de diferents autors sobre el tema, s’ha dissenyat una proposta d’intervenció per a atendre les necessitats específiques d’una aula de primer de primària on hi ha poca cohesió grupal i un ambient sensible als conflictes. Es començarà treballant a través de dinàmiques col·laboratives i participatives per fomentar l’escolta activa, el respecte, l’empatia i la companyonia. De manera que, ajuden a millorar el clima d’aula creant un ambient acollidor per a l’alumnat i així poder passar a introduir l’educació emocional amb una base de respecte i confiança. La intervenció consta d’activitats programades amb els seus respectius continguts i objectius, per a treballar durant set setmanes set emocions bàsiques, amb una avaluació inicial i una final per comprovar l’abans i el després del clima de l’aula i de les competències emocionals adquirides pels xiquets. Es pretén aconseguir en l’alumnat mitjançant aquesta intervenció una comprensió i una regulació emocional, que l’ajudarà a millorar el seu benestar emocional i social, i per consegüent, a ser feliç

Sobriety and Localic Compactness in Categories of L

The notions of L-sobriety and L-spatiality are introduced for the category L-BiTop of L-bitopological spaces. Such notions are used to extend the known adjunction between the category L-Top of L-topological spaces and the category Loc of locals to one between the category L-BiTop and BiLoc. Also, the concepts of localic regularity and localic compactness are introduced in the mentioned category

Fuzzy neighborhood structures on partially ordered groups

Ahsanullah (1988) showed the compatibility between group structures and I-fuzzy neighborhood systems. In this paper, we require not only that the I-fuzzy neighborhood systems be compatible with the group structures, but also compatible with the order relation, in one sense or another

Immunoglobulin-A and the pathogenesis of schistosomal glomerulopathy

Immunoglobin-A and the pathogenesis of schistosomal glomerulopathy. Several observations suggest that the evolution of schistosomal glomerulopathy into clinically overt and progressive disease may involve pathogenetic mechanisms other than simple glomerular deposition of parasitic antigens. In a previous study, IgA was suggested tobe a mediator of late glomerular lesions in this disease. This issue is further addressed in this work. The study includes 32 patients with hepatosplenic schistosomiasis, of whom 16 had overt glomerular involvement, along with four control groups: (a) 15 healthy volunteers; (b) 15 patients with simple intestinal mansoniasis; (c) 17 patients with non-schistosomal chronic liver disease; and (d) 21 subjects with primary nephrotic syndrome not associated with schistosomiasis. Routine assessment was done for all subjects including confirmatory tests for schistosomal infection, liver and renal function tests, hepatitis viral markers and abdominal ultrasonography. The total serum concentrations of IgG, IgM, IgA were measured, as well astheir respective circulating immune complexes, rheumatoid factors, anti-gliadin- and anti-DNA-antibodies. Liver and renal biopsies were obtained from the relevant groups and studied by light microscopy. Renal biopsies were also examined by immunofluorescence. Patients with simple intestinal schistosomiasis had a significant increase in IgM antigliadin antibodies. Those complicated with hepatosplenic involvement also had a significant increase in the mean IgG anti-gliadin antibodies, IgG rheumatoid factor and IgM anti-DNA activity. Cases further complicated by overt glomerular disease showed a distinct IgA predominance, mainly expressed in the serum anti-gliadin antibody pool and anti-DNA activity. This profile was essentially similar to that observed in control cirrhotics. There was a significant increase in the frequency of IgA glomerular deposits in renal biopsies obtained from patients with overt schistosomal glomerulopathy, in contrast to control nephrotics. The deposits were mainly mesangial, but were also encountered in subendothelial, subepithelial and peritubular locations. Their frequency was significantly higher with more advanced lesions as seen by light microscopy. The relevance of these data is discussed, leading to the following conclusions: (a) serum IgA-anti-gliadin and -anti-DNA antibodies, and glomerular IgA deposits are markers of significant renal involvement in patients with hepatosplenic schistosomiasis, (b) IgA may be involved in the pathogenesis of advanced glomerular pathology when superimposed on parasite-induced lesions, (c) There is a significant increase in serum auto-reactivity in hepatosplenic schistosomiasis, which may also have pathogentic implications, (d) Increased production by the inflammatory bowel lesions, impaired clearance by the fibrotic livers and probable switching of immunoglobulin synthesis are suggested to explain the observed IgA predominance in those who develop renal complications