Control of the modular multilevel matrix converter based on continuous control set model predictive control

The Modular Multilevel Matrix Converter (M3C) is an AC to AC power converter composed of 9 arms that has been proposed for high-power applications such as motor drive and wind energy conversion systems. Due to its complex nature, control of the M3C is usually divided into several sub-goals, and the capacitor voltage regulation varies according to the operating mode, where two classifications are commonly used: Different Frequency Mode (DFM) and Equal Frequency Mode (EFM). EFM is more challenging because of the larger capacitor voltage oscillations that can be produced. In this work, a Continuous-Control-Set Model Predictive Control (CCS-MPC) for energy management and circulating current control of the M3C is proposed. A first MPC stage solves an equality-constrained quadratic programming problem, for which an optimal solution is analytically obtained. The result is a simple control law, which ensures good transient and steady performance in EFM/DFM. The second MPC stage regulates the circulating currents with an inequality-constrained quadratic programming problem. To solve the inherent optimisation problem associated with the second CCS-MPC, an active-set algorithm is implemented. Experimental and simulation results from a 27-cell M3C prototype validate the proposed strategy and show a good overall performance

Control of the modular multilevel matrix converter based on continuous control set model predictive control

The Modular Multilevel Matrix Converter (M3C) is an AC to AC power converter composed of 9 arms that has been proposed for high-power applications such as motor drive and wind energy conversion systems. Due to its complex nature, control of the M3C is usually divided into several sub-goals, and the capacitor voltage regulation varies according to the operating mode, where two classifications are commonly used: Different Frequency Mode (DFM) and Equal Frequency Mode (EFM). EFM is more challenging because of the larger capacitor voltage oscillations that can be produced. In this work, a Continuous-Control-Set Model Predictive Control (CCS-MPC) for energy management and circulating current control of the M3C is proposed. A first MPC stage solves an equality-constrained quadratic programming problem, for which an optimal solution is analytically obtained. The result is a simple control law, which ensures good transient and steady performance in EFM/DFM. The second MPC stage regulates the circulating currents with an inequality-constrained quadratic programming problem. To solve the inherent optimisation problem associated with the second CCS-MPC, an active-set algorithm is implemented. Experimental and simulation results from a 27-cell M3C prototype validate the proposed strategy and show a good overall performance

An Overview of Modelling Techniques and Control Strategies for Modular Multilevel Matrix Converters

The Modular Multilevel Matrix Converter is a relatively new power converter topology appropriate for high-power Alternating Current (AC) to AC purposes. Several publications in the literature have highlighted the converter capabilities such as modularity, control flexibility, the possibility to include redundancy, and power quality. Nevertheless, the topology and control of this converter are relatively complex to design and implement, considering that the converter has a large number of cells and floating capacitors. Therefore multilayer nested control systems are required to maintain the capacitor voltage of each cell regulated within an acceptable range. There are no other review papers where the modelling, control systems and applications of the Modular Multilevel Matrix Converter are discussed. Hence, this paper aims to facilitate further research by presenting the technology related to the Modular Multilevel Matrix Converter, focusing on a comprehensive revision of the modelling and control strategies.Agencia Nacional de Investigacion y Desarrollo (ANID) of Chile Fondecyt 11191163 Fondecyt 1180879 Fondecyt 11190852 Fondef ID19I10370 University of Costa Rica 322-B9242 University of Santiago Dicyt 091813D

An Overview of Applications of the Modular Multilevel Matrix Converter

The modular multilevel matrix converter is a relatively new power converter topology suitable for high-power alternating current (AC)-to-AC applications. Several publications in the literature have highlighted the converter capabilities, such as full modularity, fault-redundancy, control flexibility and input/output power quality. However, the topology and control of this converter are relatively complex to realise, considering that the converter has a large number of power-cells and floating capacitors. To the best of the authors’ knowledge, there are no review papers where the applications of the modular multilevel matrix converter are discussed. Hence, this paper aims to provide a comprehensive review of the state-of-the-art of the modular multilevel matrix converter, focusing on implementation issues and applications. Guidelines to dimensioning the key components of this converter are described and compared to other modular multilevel topologies, highlighting the versatility and controllability of the converter in high-power applications. Additionally, the most popular applications for the modular multilevel matrix converter, such as wind turbines, grid connection and motor drives, are discussed based on analyses of simulation and experimental results. Finally, future trends and new opportunities for the use of the modular multilevel matrix converter in high-power AC-to-AC applications are identified.Agencia Nacional de Investigación y Desarrollo/[Fondecyt 11191163]/ANID/ChileAgencia Nacional de Investigación y Desarrollo/[Fondecyt 1180879]/ANID/ChileAgencia Nacional de Investigación y Desarrollo/[Fondecyt 11190852]/ANID/ChileAgencia Nacional de Investigación y Desarrollo/[ANID Basal FB0008]/ANID/ChileAgencia Nacional de Investigación y Desarrollo/[Fondef ID19I10370]/ANID/ChileUniversidad de Santiago/[Dicyt 091813DD]//ChileUCR::Vicerrectoría de Docencia::Ingeniería::Facultad de Ingeniería::Escuela de Ingeniería Eléctric

Balanced partitions of 3-colored geometric sets in the plane

Let SS be a finite set of geometric objects partitioned into classes or colors . A subset S'¿SS'¿S is said to be balanced if S'S' contains the same amount of elements of SS from each of the colors. We study several problems on partitioning 33-colored sets of points and lines in the plane into two balanced subsets: (a) We prove that for every 3-colored arrangement of lines there exists a segment that intersects exactly one line of each color, and that when there are 2m2m lines of each color, there is a segment intercepting mm lines of each color. (b) Given nn red points, nn blue points and nn green points on any closed Jordan curve ¿¿, we show that for every integer kk with 0=k=n0=k=n there is a pair of disjoint intervals on ¿¿ whose union contains exactly kk points of each color. (c) Given a set SS of nn red points, nn blue points and nn green points in the integer lattice satisfying certain constraints, there exist two rays with common apex, one vertical and one horizontal, whose union splits the plane into two regions, each one containing a balanced subset of SS.Peer ReviewedPostprint (published version

Continuous Set Model Predictive Control for Energy Management of Modular Multilevel Matrix Converters

The Modular Multilevel Matrix Converter is an AC-AC power converter proposed for high power applications such as motor drive and wind energy conversion systems. The M 3C has 9 clusters, allowing 4 circulating currents for converter energy management. Control of the M 3C is frequently divided into Different Frequency Mode (DFM) and Equal Frequency Mode (EFM). EFM is more challenging, because of the larger capacitor voltage oscillations that can be produced. Conventional energy management control strategies for EFM/DFM are usually based on 8 energy control loops used to define four circulating current references composed of several predefined frequencies and positive/negative sequences. The control schemes are typically different for EFM/DFM operation increasing the complexity. In this paper, a Continuous-Control-Set Model Predictive Control (CCS-MPC) for energy management of the M 3C is proposed. The control scheme is based on solving an equality constrained quadratic programming problem, using a state variable model of the M3C, where the optimal solution is analytically obtained. The result is a single and simple control law to obtain circulating current references during EFM/DFM, ensuring a good performance with optimal current specifications. The proposed strategy is experimentally validated using a down-scaled M3C prototype composed of 27 power cells

Circulating Current Control for the Modular Multilevel Matrix Converter Based on Model Predictive Control

In this work, a Continuous-Control-Set Model Predictive Control (CCS-MPC) strategy, with a saturation scheme for protection, is presented for regulating the circulating currents of a Modular Multilevel Matrix Converter (M3C). The proposed scheme is based on a state space model of the M3C and allows protection and better utilisation of the devices through a saturation scheme, which directly limits the arm currents and cluster output voltages by integrating the corresponding bounds as constraints of the CCS-MPC scheme. In order to solve the inherent optimisation problem associated to the CCS-MPC, an active-set algorithm is implemented. Experimental and simulation results from a 27-cell M3C prototype validate the proposed strategy and illustrate the good performance achieved with the methodology presented in this work

Impaired brain glucose metabolism and presynaptic dopaminergic functioning in a mouse model of schizophrenia

Background: Schizophrenia is a disease diagnosed by visible signs and symptoms from late adolescence to early adulthood. The etiology of this disease remains unknown. An objective diagnostic approach is required. Here, we used a mouse model that shows schizophrenia-like phenotypes to study brain glucose metabolism and presynaptic dopaminergic functioning by positron emission tomography (PET) and immunohistochemistry. PET scannings were performed on mice after the administration of [18F]-FDG or [18F]-F-DOPA. Glucose metabolism was evaluated in basal conditions and after the induction of a hyperdopaminergic state.Results: Mutant animals show reduced glucose metabolism in prefrontal cortex, amygdala, and nucleus reuniens under the hyperdopaminergic state. They also show reduced [18F]-F-DOPA uptake in prefrontal cortex, substantia nigra reticulata, raphe nucleus, and ventral striatum but increased [18F]-F-DOPA uptake in dorsal striatum. Mutant animals also show reduced tyrosine hydroxylase expression on midbrain neurons.Conclusions: Dopamine D2 mutant animals show reduced glucose metabolism and impaired presynaptic dopaminergic functioning, in line with reports from human studies. This mouse line may be a valuable model of schizophrenia, useful to test novel tracers for PET scanning diagnostic.Fil: Tomasella, María Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Falasco, Germán Alfredo. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia; ArgentinaFil: Urrutia, Leandro. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia; ArgentinaFil: Bechelli, Maria Lucila. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Padilla Franzotti, Carla Luciana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Gelman, Diego Matias. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentin

Channelling carbon flux through the meta-cleavage route for improved poly(3-hydroxyalkanoate) production from benzoate and lignin-based aromatics in Pseudomonas putida H

Lignin-based aromatics are attractive raw materials to derive medium-chain length poly(3-hydroxyalkanoates) (mcl-PHAs), biodegradable polymers of commercial value. So far, this conversion has exclusively used the ortho-cleavage route of Pseudomonas putida KT2440, which results in the secretion of toxic intermediates and limited performance. Pseudomonas putida H exhibits the ortho- and the meta-cleavage pathways where the latter appears promising because it stoichiometrically yields higher levels of acetyl-CoA. Here, we created a double-mutant H-ΔcatAΔA2 that utilizes the meta route exclusively and synthesized 30% more PHA on benzoate than the parental strain but suffered from catechol accumulation. The single deletion of the catA2 gene in the H strain provoked a slight attenuation on the enzymatic capacity of the ortho route (25%) and activation of the meta route by nearly 8-fold, producing twice as much mcl-PHAs compared to the wild type. Inline, the mutant H-ΔcatA2 showed a 2-fold increase in the intracellular malonyl-CoA abundance – the main precursor for mcl-PHAs synthesis. As inferred from flux simulation and enzyme activity assays, the superior performance of H-ΔcatA2 benefited from reduced flux through the TCA cycle and malic enzyme and diminished by-product formation. In a benzoate-based fed-batch, P. putida H-ΔcatA2 achieved a PHA titre of 6.1 g l–1 and a volumetric productivity of 1.8 g l–1 day–1. Using Kraft lignin hydrolysate as feedstock, the engineered strain formed 1.4 g l- 1 PHA. The balancing of carbon flux between the parallel catechol-degrading routes emerges as an important strategy to prevent intermediate accumulation and elevate mcl-PHA production in P. putida H and, as shown here, sets the next level to derive this sustainable biopolymer from lignin hydrolysates and aromatics

Route Towards a Label-free Optical Waveguide Sensing Platform Based on Lossy Mode Resonances

According to recent market studies of the North American company Allied Market Research, the field of photonic sensors is an emerging strategic field for the following years and it is expected to garner $18 billion by 2021. The integration of micro and nanofabrication technologies in the field of sensors has allowed the development of new technological concepts such as lab-on-a-chip, which have achieved extraordinary advances in terms of detection and applicability, for example in the field of biosensors. This continuous development has allowed that equipment consisting of many complex devices that occupied a whole room a few years ago, at present it is possible to handle them in the palm of the hand; that formerly long duration processes are carried out in a matter of milliseconds and that a technology previously dedicated solely to military or scientific uses is available to the vast majority of consumers. The adequate combination of micro and nanostructured coatings with optical fiber sensors has permitted us to develop novel sensing technologies, such as the first experimental demonstration of lossy mode resonances (LMRs) for sensing applications, with more than one hundred citations and related publications in high rank journals and top conferences. In fact, fiber optic LMR-based devices have been proven as devices with one of the highest sensitivity for refractometric applications. Refractive index sensitivity is an indirect and simple indicator of how sensitive the device is to chemical and biological species, topic where this proposal is focused. Consequently, the utilization of these devices for chemical and biosensing applications is a clear opportunity that could open novel and interesting research lines and applications as well as simplify current analytical methodologies. As a result, on the basis of our previous experience with LMR based sensors to attain very high sensitivities, the objective of this paper is presenting the route for the development of label-free optical waveguide sensing platform based on LMRs that enable to explore the limits of this technology for bio-chemosensing applications