A New Modulation Approach for Matrix Converter

S. Pipolo,A.Formentini,A. Trentin,P. Zanchetta,M. Calvini,M. Venturini 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

The matrix converter is an AC/AC converter constituted by an array of controlled semiconductor switches that connects directly the three-phase source to the three-phase load. The major development of matrix converters begins when Alesina and Venturini proposed the basic principles of operation in the ‘80s. In their modulation methods, through the commonmode-voltage addition technique a voltage ratio of 86.6% can be obtained. In this paper, a novel method which preserves the same voltage ratio of traditional modulations is proposed. The key concept of this approach is to use only the two closest input voltages instead of all three-phase voltages. The duties cycle are computed on the knowledge of output power demand. With this arrangement, lower switching losses in addition to better harmonic content on output current can be achieved. Hence, this paper presents a detailed mathematical treatment of new modulation approach developed for matrix converter. To validate the proposed strategy, significantly simulation results achieved in co-simulation MATLAB/SIMULINK/PLECS environment will be shown and compared with Venturini’s modulation.

Control of Grid-Connected Inverters Using Adaptive Repetitive and Proportional Resonant Schemes

Mohammad A. Abusara,Suleiman M. Sharkh,Pericle Zanchetta 전력전자학회 2015 JOURNAL OF POWER ELECTRONICS Vol.15 No.2

Repetitive and proportional-resonant controllers can effectively reject grid harmonics in grid-connected inverters because of their high gains at the fundamental frequency and the corresponding harmonics. However, the performances of these controllers can seriously deteriorate if the grid frequency deviates from its nominal value. Non-ideal proportional-resonant controllers provide better immunity to variations in grid frequency by widening resonant peaks at the expense of reducing the gains of the peaks, which reduces the effectiveness of the controller. This paper proposes a repetitive control scheme for grid-connected inverters that can track changes in grid frequencies and keep resonant peaks lined up with grid frequency harmonics. The proposed controller is implemented using a digital signal processor. Simulation and practical results are presented to demonstrate the controller capabilities. Results show that the performance of the proposed controller is superior to that of a proportional-resonant controller.

Control of Grid-Connected Inverters Using Adaptive Repetitive and Proportional Resonant Schemes

Abusara, Mohammad A.,Sharkh, Suleiman M.,Zanchetta, Pericle The Korean Institute of Power Electronics 2015 JOURNAL OF POWER ELECTRONICS Vol.15 No.2

Repetitive and proportional-resonant controllers can effectively reject grid harmonics in grid-connected inverters because of their high gains at the fundamental frequency and the corresponding harmonics. However, the performances of these controllers can seriously deteriorate if the grid frequency deviates from its nominal value. Non-ideal proportional-resonant controllers provide better immunity to variations in grid frequency by widening resonant peaks at the expense of reducing the gains of the peaks, which reduces the effectiveness of the controller. This paper proposes a repetitive control scheme for grid-connected inverters that can track changes in grid frequencies and keep resonant peaks lined up with grid frequency harmonics. The proposed controller is implemented using a digital signal processor. Simulation and practical results are presented to demonstrate the controller capabilities. Results show that the performance of the proposed controller is superior to that of a proportional-resonant controller.

Volcanoclastic flow hazard assessment in highly populated areas: a GIS-based approach applied to Torre del Greco municipality (Somma-Vesuvius, Italy)

Marina Bisson,Annarita Paolillo,Alessandro Tadini,Roberto Sulpizio,Giovanni Zanchetta 한국지질과학협의회 2018 Geosciences Journal Vol.22 No.3

This paper presents a contribution to Volcanoclastic Flows hazard assessment in very densely populated volcanic areas by using a multidisciplinary study applied to the Torre del Greco area, a municipality close to the active Somma-Vesuvius volcano, in Italy. This study integrates and combines in a GIS environment several types of data: i) information on Volcanoclastic Flows recorded during the years 1906–2010, derived from historical chronicles and local reports; ii) rainfall data relative to the investigated period; iii) summary of the recent activity of Somma-Vesuvius (AD 1631–AD 1944) deriving from the scientific literature; iv) morphological and morphometric analyses derived from a very high resolution Digital Elevation Model developed in the years 2009–2012. The historical analysis of the spatial and temporal distribution of the Volcanoclastic Flows recorded in the Vesuvian area during the last 104 years indicates that the zone mostly affected by such phenomena is the south-western sector of Somma-Vesuvius, and in particular the Torre del Greco municipality, for which a specific database on paths and directions of the historical Volcanoclastic Flows was implemented. The analysis and comparison of all available data allowed us to: i) recognize that the source zone of Volcanoclastic Flows occurred in Torre del Greco was a funnel-shaped area located immediately SW of the Somma-Vesuvius caldera boundary and just above the most urbanized area of the town; ii) individuate the key morphometric parameters (slope and curvature) necessary for the potential triggering of Volcanoclastic Flows; and iii) investigate possible relationships between the fallout deposits of the Somma-Vesuvius main recent eruptions and the historical Volcanoclastic Flows of Torre del Greco. Although this approach represents only a starting point for studies aimed at the assessment and mitigation of Volcanoclastic Flows hazard, it can be applied in other volcanic zones having similar characteristics to the Somma-Vesuvius area. Moreover, it can be used not only during a period of volcanic quiescence when heavy and/or persistent rains are able to remobilize loose pyroclastic deposits, but also in syn-eruptive conditions.

Sarcopenia in hemodialysis patients from Buenos Aires, Argentina

Ruben Abdala,Elisa Elena del Valle,Armando Luis Negri,Pablo Bridoux,Luciana Gonzalez Paganti,Marina Bravo,Luis Sintado,Paula Di Rienzo,Omar R. Schiavelli,Maria Belén Zanchetta,Adrián Guinsburg 대한골다공증학회 2021 Osteoporosis and Sarcopenia Vol.7 No.2

Objectives: Sarcopenia is the loss of skeletal muscle mass and function that occurs with aging that can lead to greater morbidity and mortality. Chronic kidney disease and hemodialysis (HD) favors the development of sarcopenia.We studied the prevalence of sarcopenia and its components using European Working Group on Sarcopenia in Elderly People 2 proposed criteria and risk factors for its development in HD patients. Methods: In 100 adult HD patients, we evaluated: hand grip strength (HGS), muscle mass by dual energy X-ray absorptiometry and physical performance (gait-speed and sit-stand test). Results: Sixty patients were male and 40 were female; mean age 55.6 years. Prevalence of sarcopenia was 16% (11.1% in males and 25% in females; P = 0.05); 7% had severe sarcopenia. Prevalence of low HGS was 33% in males and 28% in females; low muscle mass was 30% in males but 70% in females and low physical performance 23% in males and 45% in females. Falls were reported by 23 patients. Patients with lower HGS had a higher prevalence of falls in the last year (40% two or more falls; P = 0.03). Only females with sarcopenia had lower bone mineral content. Neither age, body mass index, time on dialysis, or prevalence of diabetes predicted sarcopenia. Conclusions: A significant proportion of dialysis patients had sarcopenia, more frequent in females. Low HGS was associated with a higher prevalence of falls. Only females with sarcopenia had lower bone mineral content.