In this paper, the principle of modularity is used to derive the different multilevel voltage and current source converter topologies. The paper is primarily focused on high-power applications and specifically on high-voltage dc systems. The derived converter cells are treated as building blocks and are contributing to the modularity of the system. By combining the different building blocks, i.e., the converter cells, a variety of voltage and current source modular multilevel converter topologies are derived and thoroughly discussed. Furthermore, by applying the modularity principle at the system level, various types of high-power converters are introduced. The modularity of the multilevel converters is studied in depth, and the challenges as well as the opportunities for high-power applications are illustrated.

Modular Multilevel Converters for HVDC Applications: Review on Converter Cells and Functionalities

Multilevel converters (MLCs) have emerged as standard power electronic converters in high power as well as quality demanding applications. They are classified into current-fed MLCs and voltage-fed MLCs. Voltage-fed MLCs have widely researched whereas the current-fed MLCs are the recent topic of research. Based on the principle of duality between voltage and current sources, several current-fed MLCs analogous to voltage-fed MLCs have been identified. Current-fed MLCs offer several advantages in terms of high power capability, transformerless operation, short-circuit protection, and excellent quality of output current waveform. The goal of this paper is: 1) to present review of circuit topologies, modulation schemes, and applications of current-fed MLCs; and 2) to review an emerging low-device switching frequency modulation technique known as synchronous optimal pulsewidth modulation for current-fed MLCs. The circuit configuration and advantages of each topology along with various modulation techniques are discussed in detail. Compared to voltage-fed MLCs, the operation of current-fed MLCs need to satisfy additional switching constraints. A survey of classical methods for realization of these operational constraints has been done and a new generalized method has been proposed. Finally, future scope of research has been presented to encourage further development of topologies and modulation techniques for current-fed MLCs.

Current-Fed Multilevel Converters: An Overview of Circuit Topologies, Modulation Techniques, and Applications

Setting B2B digital marketing in artificial intelligence-based CRMs: A review and directions for future research

In this paper, a new configuration of a three-phase five-level multilevel voltage-source inverter is introduced. The proposed topology constitutes the conventional three-phase two-level bridge with three bidirectional switches. A multilevel dc link using fixed dc voltage supply and cascaded half-bridge is connected in such a way that the proposed inverter outputs the required output voltage levels. The fundamental frequency staircase modulation technique is easily used to generate the appropriate switching gate signals. For the purpose of increasing the number of voltage levels with fewer number of power electronic components, the structure of the proposed inverter is extended and different methods to determine the magnitudes of utilized dc voltage supplies are suggested. Moreover, the prototype of the suggested configuration is manufactured as the obtained simulation and hardware results ensured the feasibility of the configuration and the compatibility of the modulation technique is accurately noted.

New Three-Phase Multilevel Inverter With Reduced Number of Power Electronic Components

Transformerless Inverter With Virtual DC Bus Concept for Cost-Effective Grid-Connected PV Power Systems

This paper presents a new circuit configuration of single-phase multilevel current-source inverter (CSI). In this new topology, a basic H-bridge CSI working as a main inverter generates a multilevel current waveform in cooperation with inductor cells connected in parallel as auxiliary circuits. Each inductor cell is composed by four unidirectional power switches with an inductor across the cell circuit. The inductor cells work by generating the intermediate level of the multilevel current waveform with no additional external dc-power sources. A simple proportional-integral controller is applied to control the intermediate-level currents of the multilevel output waveform. A five-level and a nine-level pulsewidth-modulation inverter configuration, with chopper-based dc-current sources, are verified through computer simulations. Furthermore, an experimental prototype of a five-level CSI is set up and is tested. The results show that the test circuit works properly to generate the multilevel output-current waveform with low output harmonics by using small size of inductors without any additional external dc-power sources, which proves feasibility of the proposed strategy.

Multilevel Current Waveform Generation Using Inductor Cells and H-Bridge Current-Source Inverter

, This study aimed to test whether there is a relationshipÂ  of self-efficacy and social support with students adjustment inÂ  learning. Subjects were 123 students of class VII students consisting of 62 men and 61 women taken at random in SMP Negeri 1 Larangan kabupaten Pamekasan. The results of multiple regression analysis obtained for R = 0.759 ; F = 81.600 , p = 0.000 ( p < 0.01 ) . The results of the analysis of this data show self-efficacy and social support of parents jointly associated with the adjustment of students in learning , at 56.9 % . Results of correlation analysis of self-efficacy with self-adjustment of students in the learning acquired partial r = 0.430 ; t = 5.222 and p = 0.000 ( p < 0.01 ) . These data show there is a positive correlation between self-efficacy with self-adjustment of students in learning , with effective contribution of 24.22% . The results of correlation analysis of parent social support with students adjustment in learning obtained partial r = 0.580 ; t = 7.799 and p = 0.000 ( p < 0.01 ) . These data show there is a positive correlation between social support of parents with students adjustment in learning, the effective contribution of 32.68%. Keyword : Adjustment, self efficacy, social support of parents.

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Efikasi Diri, Dukungan Sosial Dan Penyesuaian Diri Dalam Belajar

This paper presents a circuit configuration of five-level PWM voltage-source inverter developed from the three-level H-bridge inverter using only a single DC input power source. In the proposed five-level inverter, an auxiliary circuits working as the voltage balancing circuits of the inverter’s DC capacitors is presented. The auxiliary circuits work to keep stable DC capacitor voltages of the inverter, and also to reduce the capacitor size of the inverter. The unique point of the proposed balancing circuits is that it needs only a single voltage sensor to control the voltages of the two capacitors in the inverter. Moreover, a minimum number the inverter’s switching devices is also an important feature of the proposed inverter topology. A simple proportional integral controller is applied to control the voltage of the DC capacitors. The proposed topology is tested through computer simulation using PSIM software. Laboratory experimental tests were also conducted to verify the proposed inverter circuits. The computer simulation and experimental test results showed that the proposed balancing circuits works properly keeping stable voltages across the two DC capacitors of the inverter using only a single voltage sensor. The inverter also works well to synthesize a five-level PWM voltage waveform with sinusoidal load current.

Five-level PWM Inverter with a Single DC Power Source for DC-AC Power Conversion

Penelitian ini bertujuan untuk mengukur pengaruh modal psikologis dan kreativitas individu terhadap perilaku inovasi individu pada dosen wanita di salah satu perguruan tinggi swasta di Tangerang. Dalam penelitian ini, kreativitas individu merupakan variabel mediasi. Data dikumpulkan dari 89 kuesioner yang dikembalikan dari sampel yang diambil secara random sampling. Data dianalisis menggunakan metode SEM dengan software SmartPLS 3.0. Hasil penelitian ini menunjukkan bahwa modal psikologis berpengaruh signifikan terhadap kreativitas individu, modal psikologis dan kreativitas individu berpengaruh signifikan terhadap perilaku inovasi individu, kreativitas individu memdiasi hubungan antara modal psikologis dan perilaku inovasi individu. Kreativitas individu berfungsi sebagai mediator parsial. Penelitian baru ini mengusulkan suatu model untuk mengelola perilaku inovasi individu pada dosen perempuan pada unit analisis perguruan tinggi swasta di Tangerang melalui pengembangan modal psikologis dengan kreativitas individu sebagai mediator. Penelitian ini dapat membuka jalan untuk meningkatkan kesiapan dosen dalam menghadapi era education 4.0.

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Esensi Modal Psikologis Dosen: Rahasia Kreativitas dan Inovasi di Era Education 4.0

A simplified circuit topology of the five-level pulse width modulation (PWM) inverter for DC-AC power conversion with no-isolated DC voltage sources and reduced switching device number is presented in this paper. The inverter circuit is based on the three-level H-bridge inverter configuration. The developed five-level inverter needs only five controlled power switches and four isolated gate drive circuits. Furthermore, the proposed topology does not require bidirectional power semiconductor controlled switches, hence a conventional discrete power MOSFETs or IGBTs can be used to build the inverter circuits. To obtain a better quality output voltage waveform, the level-phase-shifted carriers based sinusoidal pulse width modulation control was applied to produce a five-level PWM voltage waveform. The proposed inverter circuit was examined by using computer simulation with Power PSIM software. The basic principle operation of the inverter circuit was verified experimentally in laboratory using two non-isolated DC voltage sources as the inputs of the inverter’s prototype circuit. Some analysis of inverter’s output waveforms are provided and discussed.

http://ijeecs.iaescore.com/index.php/IJEECS/article/download/13757/10462

Suroso Suroso

Papers

Multilevel Current Waveform Generation Using Inductor Cells and H-Bridge Current-Source Inverter

Efikasi Diri, Dukungan Sosial Dan Penyesuaian Diri Dalam Belajar

Five-level PWM Inverter with a Single DC Power Source for DC-AC Power Conversion

Esensi Modal Psikologis Dosen: Rahasia Kreativitas dan Inovasi di Era Education 4.0

Simplified five-level voltage source inverter with level-phase-shifted carriers based modulation technique