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1

Comparative analysis of multilevel voltage source inverters used to supply a five-phase Permanent Magnet Synchronous Motor

Parfianowicz Kamil

Przegląd Elektrotechniczny

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2022

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R. 98, nr 10

90--94

EN

The paper presents the comparative analysis of the use a two-level, three-level and five-level voltage source inverter (VSI) for supplying a five-phase synchronous motor with permanent magnets (PMSM). The motor was controlled by Indirect Field Oriented Control (IFOC) with Space Vector Modulation (SVM). Simulation tests showing influence of the inverter topology on the drive system were performed in the Matlab/Simulink environment for various values of the switching frequency - from 1 to 30 kHz. The aim of the presented simulation research is analysis of the prototype five-phase PMSM machine and preliminary development of the power supply system based on multilevel inverters. As a result it will allow to correct determination of the rated parameters of the selected devices (mainly the measurement system and semiconductors). The created model can also be used as part of a larger simulation system, e.g. in an electric vehicle.

PL

W pracy przedstawiona została analiza porównawcza zastosowania dwupoziomowego, trójpoziomowego oraz pięciopoziomowego falownika napięcia (VSI) służącego do zasilania pięciofazowego silnika synchronicznego z magnesami trwałymi. Do sterowania układu napędowego zaimplementowano tzw. sterowanie polowo-zorientowane pośrednie (IFOC) z użyciem modulatora wektora przestrzennego SVM (Space Vector Modulation). Przeprowadzone badania symulacyjne w środowisku Matlab/Simulink zostały wykonane dla różnych wartości częstotliwości kluczowania – od 1 do 30 kHz. Celem prezentowanych badań symulacyjnych jest analiza prototypowej pięciofazowej maszyny PMSM oraz wstępne opracowanie układu zasilania opartego na falownikach wielopoziomowych. W rezultacie pozwoli to na poprawne określenie parametrów znamionowych wybranych urządzeń (głównie układu pomiarowego i półprzewodników). Stworzony model może być również wykorzystany w ramach większego systemu symulacyjnego, np. w pojeździe elektrycznym.

2

Multilevel inverter with optimal THD through the firefly algorithm

El Mehdi Belkacem R., Benzid R., Bouguechal N.

Archives of Electrical Engineering

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2017

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Vol. 66, nr 1

141--154

EN

Reduction of the Total Harmonic Distortion (THD) in multilevel inverters requires resolution of complex nonlinear transcendental equations; in this paper we propose a combination of one of the best existing optimized hardware structures with the recent firefly algorithm, which was used to optimize the THD, through finding the best switching angles and guaranteeing the minimization of harmonics within a user defined bandwidth. The obtained THD through the simulation of the thirteen-level symmetric inverter has been reduced down to 5% (FFT of 60 harmonics). In order to validate the simulation results, a thirteen-level symmetric inverter prototype has been made, and practically experimented and tested with different loads. Consequently, the measured THD with resistive load was 4.7% on a bandwidth of 3 kHz. The main advantage of the achieved work is the reduction of the THD.

3

A multilevel switched capacitor DC-DC converter. An analysis of resonant operation conditions

Kawa A. H., Stala R.

Power Electronics and Drives

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2016

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Vol. 1 (36), No. 2

35--53

EN

This paper presents the research results of a multilevel switched capacitor DC-DC converter (MLSCC). The converter, for power electronic applications, can operate in ZCS mode by utilizing resonant circuits for recharging the switched capacitors. The main focus of this article is an in-depth original analysis of the waveforms and the converter voltage ratio. The concept of the converter is verified by simulation results of the circuit in MATLAB/Simulink Sim Power Systems. The formulas given in the mathematical analysis are evaluated for example parameters of the components with the use of numerical approach in MATLAB software. Plot sets are presented in order to judge the influence of the parameters on converter performance. All non-expected relations are explained based on mathematical analysis. The possibilities of the design optimization are identified and presented based on the anticipated results. The present analysis is important for the converter design process and can be used for numerical multi-object optimization to further improve the converter design.

4

Towards a multi-level governance framework for MSP in the Baltic

Schultz-Zehden A., Gee K.

Biuletyn Instytutu Morskiego w Gdańsku

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2016

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Vol. 31, No. 1

34--44

EN

The Baltic Sea Region stands out as an early adopter of a transboundary approach to marine/maritime spatial planning (MSP). Various common principles have been established for MSP in the Baltic, but despite some initial suggestions, these have not yet been translated into structures and processes that could facilitate transboundary MSP governance in the BSR. This paper draws on the recent PartiSEApate project to outline recommendations for a multi-level governance framework for MSP in the Baltic. Based on empirical work, needs and visions for a pan-Baltic MSP dialogue are first outlined from the perspective of sectoral stakeholders and governance representatives. The paper then presents suggestions for adapting existing structures, most notably the HELCOM/VASAB MSP Working Group, to facilitate a pan-Baltic MSP dialogue that is needs-based, results-oriented and realistic. Suggestions are also presented for extending cross-border consultation on MSP as part of a multi-level governance framework. The paper concludes with an outlook to developments in 2015 and general lessons for transboundary MSP.

PL

Region Morza Bałtyckiego wyróżnia się jako pionier w przyjmowaniu transgranicznego podejścia do planowania przestrzennego obszarów morskich (PPOM). Mimo wstępnych sugestii, ustalone różnorakie wspólne zasady PPOM na Bałtyku nie przekładają się jak dotąd na struktury i procedury, które mogłyby ułatwić administracyjną współpracę transgraniczną w zakresie PPOM w regionie Morza Bałtyckiego. Niniejszy tekst nakreśla zalecenia dla stworzenia wielopoziomowych ram zarządzania PPOM na Bałtyku, w czym opiera się na opracowanym niedawno projekcie PartiSEApate. Jako pierwsze opisano w oparciu o praktyczne doświadczenia potrzeby i wyobrażenia o panbałtyckim dialogu w zakresie PPOM z perspektywy zainteresowanych podmiotów i przedstawicieli administracji w poszczególnych sektorach. W kolejnej części pracy zaprezentowano propozycje przyjęcia istniejących już struktur, w szczególności planu grupy roboczej HELCOM/VASAB, w celu usprawnienia panbałtyckiego dialogu na temat PPOM, tak by ten opierał się na ocenie potrzeb, był zorientowany na wyniki i realistyczny. Zaprezentowano także sugestie rozszerzenia zakresu konsultacji transgranicznych dotyczących PPOM w ramach wielopoziomowych struktur zarządzania. Podsumowanie pracy stanowi bilans postępów osiągniętych w 2015 roku oraz ogólne wnioski dla transgranicznej polityki PPOM.

5

Solving linear fractional multi-level programs

Bhargava S.

Operations Research and Decisions

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2014

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Vol. 24, No. 1

5--21

EN

The linear fractional multilevel programming (LFMP) problem has been studied and it has been proved that an optimal solution to this problem occurs at a boundary feasible extreme point. Hence the Kth-best algorithm can be proposed to solve the problem. This property can be applied to quasiconcave multilevel problems provided that the first (n – 1) level objective functions are explicitly quasimonotonic, otherwise it cannot be proved that there exists a boundary feasible extreme point that solves the LFMP problem.

6

Stabilization of multi DC bus link voltages of multilevel NPC VSI. Application to double stator induction motors

Beriber D., Talha A., Boucherit M. S.

Archives of Control Sciences

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2012

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Vol. 22, no. 1

107-120

EN

Voltage source multilevel inverters have become very attractive for power industries in power electronics applications during last years. The main purposes of studying multilevel inverters are the generation of output voltage signals with low harmonic distortion and reduction of switching frequency. An important issue of the multilevel inverter is the capacitor voltage-balancing problem. The unbalance of different DC voltage sources of multilevel neutral point clamped (NPC) voltage source inverter (VSI) constitutes the major limitation for the use of this new power converter. In this paper, we present study on the stability problem of the input DC voltages of the three-level Neutral Point Clamping (NPC) voltage source inverter (VSI). This inverter is useful for application in high voltage and high power area. In the first part, we remind the model of double stator induction motors (DSIM). Then, we develop control models of this inverter using the connection functions of the semi-conductors. We propose a Pulse Width Modulation (PWM) strategy to control this converter. The inverter is fed by constant input DC voltages. In the last part, we study the stability problem of the input DC voltages of the inverter. A cascade constituted by two three-level PWM rectifiers - two three-level NPC VSI - DSIM is discussed. The results obtained show that the input DC voltages of the inverters are not stable. To solve this problem, we propose to use a half clamping bridge. This solution is very promising in order to stabilize the input DC voltages of this converters.

7

A contravariant velocity based implicit multilevel method for simulating the whole process of incompressible flow transition arround Joukowsky airfoils

Liu Z., Liu C., Xiong G.

Applied Mechanics and Engineering

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1998

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Vol. 3, no 1

111-161

EN

A contravanant velocity based incompressible Navier-Stokes governing system is derived to generate an implicit multi-level method so that we can simulate the receptivity and flow transition in cases with complex geometnes. The two- and three- dimensional development of leading-edge receptivity and flow transition in a 2-D Joukowsky airfoil boundary layer are investigated by direct numencal simulation (DNS) using this system. The numencal investigation is based on the so-called spatial approach. The numencal results agree very well with linear stability theory (LST) and the experimental results for the flat plate case. They also agree well with the result obtained by other researchers for the 2-D elliptic leadingedge receptivity case. Some new phenomena for the transition around Joukowsky airfoils are abserved. The details of this approach are described.