Sanjeevikumar Padmanaban

Bio: Sanjeevikumar Padmanaban is an academic researcher from Aarhus University. The author has contributed to research in topics: Photovoltaic system & Boost converter. The author has an hindex of 34, co-authored 367 publications receiving 5244 citations. Previous affiliations of Sanjeevikumar Padmanaban include Sathyabama University & National Institute of Technology, Puducherry.

Implementation of APSO and Improved APSO on Non-Cascaded and Cascaded Short Term Hydrothermal Scheduling

Abstract: Short-term hydrothermal scheduling (STHTS) is a highly non-linear, multi-model, non-convex, and multi-dimensional optimization problem that has been worked upon for about 5 decades. Many research articles have been published in solving different test cases of STHTS problem, while establishing the superiority of one type of optimization algorithm over the type, in finding the near global best solution of these complex problems. This paper presents the implementation of an improved version of a variant of the Particle Swarm Optimization algorithm (PSO), known as Accelerated Particle Swarm Optimization (APSO) on three benchmark test cases of STHTS problems. The adaptive and variable nature of the local and global search coefficients for the proposed APSO significantly improve its performance in obtaining the optimal solution for the STHTS test cases. Two of these cases are non-cascaded cases of STHTS problem (NCSTHTS) and one case is cascaded case of STHTS problem (CSTHTS). The results are compared with the results of the previous implementations of the other algorithms as presented in the literature. Due to the stochastic nature of the meta-heuristic algorithms, the parametric and non-parametric statistical tests have been implemented to establish the superiority of results of one type of algorithm over the results of the other type of algorithms.

Modified multilevel buck–boost converter with equal voltage acrosseach capacitor: analysis and experimental investigations

Abstract: Recently, the circuitry of Multilevel Buck-Boost Converter (here, called MBBC 1 ) is suggested in the literature to attain high inverting voltage by increasing the output levels of the classical buck-boost converter. However, the only circuitry is suggested and detail investigations are not provided. The major drawbacks of MBBC 1 are the voltages across the load capacitors side are unequal and the input current is not continuous. Therefore, the MBBC 1 is not well suited to feed multilevel inverter where a stack of capacitors is required with equal voltage across each capacitor. A new modified MBBC called MBBC 2 is proposed to achieve continuous input current and equal voltage across each capacitor. The circuitry of MBBC 1 and MBBC 2 configurations are analysed with non-idealities to investigate its effects on the voltage conversion ratio. The Continuous Conduction Mode (CCM) and Discontinuous Conduction Mode (DCM) boundary conditions and modes of operation for MBBC 1 and MBBC 2 configurations are presented. The procedure for basics design and components selection is elaborated. Additionally, comparison of MBBC 1 , MBBC 2 and recently proposed a non-isolated DC-DC configuration is provided. The performances of MBBC 1 and MBBC 2 configurations are tested with simulation and experimental work, and obtained results consistently show a good agreement with the theoretical approach..

A New Three-Phase Multi-Level Asymmetrical Inverter With Optimum Hardware Components

Abstract: In this article, a novel three-phase asymmetrical multilevel inverter is presented. The proposed inverter is designed with an optimal hardware components to generate three-phase nineteen output voltage levels. The proposed inverter exhibits various advantages like a suitable output voltage waveform with improved power quality, lower total harmonic distortion (THD), and more moderate complexity, reduction in cost, reduced power losses, and improved efficiency. A comparison of the proposed topology in terms of several parameters with existing methods illustrates its merits and features. The proposed inverter tested with steady-state and dynamic load disturbances. Various experimental results are included in this article to validate the performance of the proposed inverter during various extremities. In addition, a detailed comparison is tabulated between simulation and experimental results graphically. The proposed inverter has been stable even during load disturbance conditions. The simulation and feasibility model are verified using a prototype model.

Double Stage Double Output DC–DC Converters for High Voltage Loads in Fuel Cell Vehicles

Abstract: This article aims to enhance the output voltage magnitude of fuel cells (FCs), since the actual generation is low. The traditional technique is too complicated and has a cascaded or parallel connection solution to achieve high voltage for multiple loads in vehicles. In this case, electronic power converters are a viable solution with compact size and cost. Hence, double or multiple output DC–DC converters with high voltage step up are required to feed multiple high voltage loads at the same time. In this article, novel double stage double output (DSDO) DC–DC converters are formulated to feed multiple high voltage loads of FC vehicular system. Four DSDO DC–DC converters called DSDO L–L, DSDO L-2L, DSDO L-2LC, and DSDO L-2LC are developed in this research work and all the converters are derived based on the arrangement of different reactive networks. The primary power circuitry, conceptual operation, and output voltage gain derivation are given in detail with valid proof. The proposed converters are compared with possible parallel combinations of conventional converters and recently available configuration. Comprehensive numerical simulation and experimental prototype results show that our theoretical predictions are valid and that the configuration is applicable for real time application in FC technologies for ‘more-electric vehicles’.

New 2LC-Y DC-DC converter topologies for high-voltage/low-current renewable applications: New members of X-Y converter family

Abstract: New members of XY converter family topologies are proposed in this treatise for a high-voltage/low-current renewable application. Based on the X Converter, the whole existing X-Y Converter family is categorized into four categories; L-Y, 2L-Y, 2LC-Y and 2LCm-Y converter. Four new 2LC-Y topologies (2LC-LVD, 2LC-2LVD, 2LC-2LCVD and 2LC-2LCmVD) converters are presented in this treatise which offer an effective solution for renewable applications requiring a very high voltage conversion ratio such as a Photovoltaic Multilevel Inverter (PV-MLI) system, hybrid electrical drives and automotive applications. The noticeable features of the proposed 2LC-Y converter topologies are: i) Only one power control switch and input source; ii) High negative output voltage with moderate duty ratio; iii) Low output current and minimal internal resistance; iv) Transformer-less converter topologies; v) High voltage conversion ratio; vi) Minimal number of power devices and components. Working and output voltage analysis of the proposed 2LC-Y converter topologies are discussed in details. The MATLAB simulation results are provided and good agreement with theoretical analysis is shown. Simulation results also validate the performance and functionality of the proposed 2LC-Y converter topologies of the XY converter family.

I and i

Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

Exoelectrogenic bacteria that power microbial fuel cells

Abstract: The use of microbial fuel cells to generate electrical current is increasingly being seen as a viable source of renewable energy production In this Progress article, Bruce Logan highlights recent advances in our understanding of the mechanisms used by exoelectrogenic bacteria to generate electrical current and the important factors to consider in microbial fuel cell design There has been an increase in recent years in the number of reports of microorganisms that can generate electrical current in microbial fuel cells Although many new strains have been identified, few strains individually produce power densities as high as strains from mixed communities Enriched anodic biofilms have generated power densities as high as 69 W per m2 (projected anode area), and therefore are approaching theoretical limits To understand bacterial versatility in mechanisms used for current generation, this Progress article explores the underlying reasons for exocellular electron transfer, including cellular respiration and possible cell–cell communication