Predictive Switching Control for Multilevel Inverter using CNN-LSTM for Voltage Regulation

Now-a-days, model predictive control (MPC) is very commonly used for three phase inverters. But conventional MPC suffers computational complexities as well as unstable switching frequency issues. To address these issues related with conventional MPC model, this paper aims to use the benefits of deep learning model for predictive switching control. In this paper, CNN-LSTM network based predictive control is proposed for three phase inverters. Along with predictive control LC filter is cascaded to reduce the harmonics. The model is simulated using SIMULINK under fixed and dynamic load condition. The result shows decreased THD under different load conditions. Finally, the result is validated with existing models and achieves better performance

Single phase asymmetrical multilevel inverter topology with reduced device count

Multilevel Inverters (MLIs) are vital components for medium voltage and high-power applications. However, the number of components will increase with increased output voltage levels. It leads to high power losses. In this thesis, a new single-phase asymmetrical multilevel inverter topology used for medium and high voltage applications is proposed. The topology is capable of producing n-level output voltage with reduced device counts. It is achieved by arranging available switches and direct current (dc)-sources to obtain the maximum combinations of addition and subtraction of the input dc-sources. A comprehensive literature review has been carried out, and the proposed topology is compared with the topologies available in the literature. Comparison based on the number of switches utilized, the number of dc sources used, and the total number of devices is made. To verify the viability of the proposed topology, circuit models for 9-level, 25-level, and 67-level inverters are developed and simulated in Matlab-Simulink software first. Voltage and current waveforms and THD for resistive and inductive loads are obtained from the simulation model and validated with the experimental setup. Experimental results of the proposed inverter prototype for 9-level and 25-level output, developed in the laboratory, are presented. A low-frequency and high-frequency switching strategy for the proposed inverter topology are also presented in this work. Thermal modelling of the proposed topology is done in PLECS software, and detailed loss analysis for 9-level as well as 25-level topologies is carried out. The fundamental topology utilizes 9 switches with a total standing voltage (TSV) of 6.75 per unit while the 25-level topology structure has 12 switches with the TSV of 6.92 per unit only. Comparison with the other multilevel topologies shows that the proposed circuit requires fewer power switches and dc-sources to produce the same output levels. Due to the low switching frequency requirement, the proposed topology is applicable for high and medium voltage applications, resulting in lower switching losses

A Systems Engineering Reference Model for Fuel Cell Power Systems Development

This research was done because today the Fuel Cell (FC) Industry is still in its infancy in spite over one-hundred years of development has transpired. Although hundreds of fuel cell developers, globally have been spawned, in the last ten to twenty years, only a very few are left struggling with their New Product Development (NPD). The entrepreneurs of this type of disruptive technology, as a whole, do not have a systems engineering \u27roadmap , or template, which could guide FC technology based power system development efforts to address a more environmentally friendly power generation. Hence their probability of achieving successful commercialization is generally, quite low. Three major problems plague the fuel cell industry preventing successful commercialization today. Because of the immaturity of FC technology and, the shortage of workers intimately knowledgeable in FC technology, and the lack of FC systems engineering, process developmental knowledge, the necessity for a commercialization process model becomes evident. This thesis presents a six-phase systems engineering developmental reference model for new product development of a Solid Oxide Fuel Cell (SOFC) Power System. For this work, a stationary SOFC Power System, the subject of this study, was defined and decomposed into a subsystems hierarchy using a Part Centric Top-Down, integrated approach to give those who are familiar with SOFC Technology a chance to learn systems engineering practices. In turn, the examination of the SOFC mock-up could gave those unfamiliar with SOFC Technology a chance to learn the basic, technical fundamentals of fuel cell development and operations. A detailed description of the first two early phases of the systems engineering approach to design and development provides the baseline system engineering process details to create a template reference model for the remaining four phases. The NPD reference template model\u27s systems engineering process, philosophy and design tools are presented in great detail. Lastly, the thesi

A Systems Engineering Reference Model for Fuel Cell Power Systems Development

This research was done because today the Fuel Cell (FC) Industry is still in its infancy in spite over one-hundred years of development has transpired. Although hundreds of fuel cell developers, globally have been spawned, in the last ten to twenty years, only a very few are left struggling with their New Product Development (NPD). The entrepreneurs of this type of disruptive technology, as a whole, do not have a systems engineering \u27roadmap , or template, which could guide FC technology based power system development efforts to address a more environmentally friendly power generation. Hence their probability of achieving successful commercialization is generally, quite low. Three major problems plague the fuel cell industry preventing successful commercialization today. Because of the immaturity of FC technology and, the shortage of workers intimately knowledgeable in FC technology, and the lack of FC systems engineering, process developmental knowledge, the necessity for a commercialization process model becomes evident. This thesis presents a six-phase systems engineering developmental reference model for new product development of a Solid Oxide Fuel Cell (SOFC) Power System. For this work, a stationary SOFC Power System, the subject of this study, was defined and decomposed into a subsystems hierarchy using a Part Centric Top-Down, integrated approach to give those who are familiar with SOFC Technology a chance to learn systems engineering practices. In turn, the examination of the SOFC mock-up could gave those unfamiliar with SOFC Technology a chance to learn the basic, technical fundamentals of fuel cell development and operations. A detailed description of the first two early phases of the systems engineering approach to design and development provides the baseline system engineering process details to create a template reference model for the remaining four phases. The NPD reference template model\u27s systems engineering process, philosophy and design tools are presented in great detail. Lastly, the thesi

Recently Developed Reduced Switch Multilevel Inverter for Renewable Energy Integration and Drives Application: Topologies, Comprehensive Analysis and Comparative Evaluation

Recently, multilevel inverters (MLIs) have gained lots of interest in industry and academia, as they are changing into a viable technology for numerous applications, such as renewable power conversion system and drives. For these high power and high/medium voltage applications, MLIs are widely used as one of the advanced power converter topologies. To produce high-quality output without the need for a large number of switches, development of reduced switch MLI (RS MLI) topologies has been a major focus of current research. Therefore, this review paper focuses on a number of recently developed MLIs used in various applications. To assist with advanced current research in this field and in the selection of suitable inverter for various applications, significant understanding on these topologies is clearly summarized based on the three categories, i.e., symmetrical, asymmetrical, and modified topologies. This review paper also includes a comparison based on important performance parameters, detailed technical challenges, current focus, and future development trends. By a suitable combination of switches, the MLI produces a staircase output with low harmonic distortion. For a better understanding of the working principle, a single-phase RS MLI topology is experimentally illustrated for different level generation using both fundamental and high switching frequency techniques which will help the readers to gain the utmost knowledge for advance research

Modulation with metaheuristic approach for cascaded-MPUC49 asymmetrical inverter with boosted output

This work introduces a 49-level Asymmetrical Inverter (AMLI) with boosted output based on the cascaded operation of two 7-Level Modified Packed U-Cell inverters (MPUC-7). The converter is capable of operation with a boosted voltage of up to 1.714 times the maximum DC voltage employed. It requires only 12 active switches and 4 voltage sources. With the sources set in the ratio of 14:7:2:1, the 7-level output of the two converters is so utilized that the 72 = 49-level output voltage is generated across the load. A detailed explanation of level formation is discussed. This converter is operated using an Artificial Neural Network (ANN) which is trained for the harmonic elimination in the output voltage waveform. For the calculation of optimum angles, a meta-heuristic based Genetic Algorithm (GA) technique is employed. The generation of 49-level output requires 24 transitions in one quarter of a cycle. All these angles are generated for various desired output voltages, and the ANN is trained offline for the same. The converter and its control are simulated in MATLAB/Simulink environment, and the results are verified on the experimental setup. The multilevel output thus obtained is nearly sinusoidal and the Total Harmonic Distortion (THD) thus produced is under the specified limit of IEEE.This work was supported in part by the Qatar University-Marubeni Concept to Prototype Development Research from the Qatar University under Grant M-CTP-CENG-2020-2, and in part by the Qatar National Library, Doha, Qatar.Scopu

Design, Optimization and Implementation of a High Frequency Link Multilevel Cascaded Inverter

This thesis presents a new concept of cascaded MLI (CMLI) device reduction by utilizing low and high frequency transformer link. Two CMLI topologies, symmetric and asymmetric are proposed. Compared with counterpart CMLI topologies available in the literatures, the proposed two inverter topologies in this thesis have the advantages of utilizing least number of electronic components without compromising overall performance particularly when a high number of levels is required in the output voltage waveform

The Fifth NASA Symposium on VLSI Design

The fifth annual NASA Symposium on VLSI Design had 13 sessions including Radiation Effects, Architectures, Mixed Signal, Design Techniques, Fault Testing, Synthesis, Signal Processing, and other Featured Presentations. The symposium provides insights into developments in VLSI and digital systems which can be used to increase data systems performance. The presentations share insights into next generation advances that will serve as a basis for future VLSI design

Review of Five-Level Front-End Converters for Renewable Energy Applications

Provisional fileWith the objective of minimizing environment and energy issues, distributed renewable energy sources have reached remarkable advancements along the last decades, with special emphasis on wind and solar photovoltaic installations, which are deemed as the future of power generation in modern power systems. The integration of renewable energy sources into the power system requires the use of advanced power electronics converters, representing a challenge within the paradigm of smart grids, e.g., to improve efficiency, to obtain high power density, to guarantee fault-tolerance, to reduce the control complexity and to mitigate power quality problems. This paper presents a specific review about front-end converters for renewable energy applications (more specifically the power inverter that interfaces the renewable energy source with the power grid). It is important to note that the objective of this paper is not to cover all types of front-end converters; the focus is only on single-phase multilevel structures limited to five voltage levels, based on a voltage-source arrangement and allowing current or voltage feedback control. The established review is presented considering the following main classifications: (a) Number of passive and active power semiconductors; (b) Fault tolerance features; (c) Control complexity; (d) Requirements of specific passive components as capacitor or inductors; (e) Number of independent or split dc-link voltages. Throughout the paper, several specific five-level front-end topologies are presented and comparisons are made between them, highlighting the pros and cons of each one of them as a candidate for the interface of renewable energy sources with the power grid.Fundação para a Ciência e Tecnologia (FCT