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.

A Novel High Gain Configurations of Modified SEPIC Converter for Renewable Energy Applications

Abstract: A novel configurations of a non-isolated Modified SEPIC Converter with two Voltage Lift Switched Inductor (MSC VLSI ) modules namely MSC VLSI -XYL, MSC VLSI -LYZ and MSC VLSI -XLZ are presented in the paper. The key features of these configurations are, 1) high voltage conversion ratio, 2) single controlled switch, 3) high-value input inductor to smooth the input current, 4) maximum utilization of input source, 5) continuous input current. With these notable features, proposed configurations are more convenient for high voltage renewable energy applications to boost the low voltage of photovoltaic array/fuel cell. The feasibility of these converter configurations are verified by mathematical analysis and simulation results. MSC VLSI configurations are simulated for 250 W resistive load and at 50 kHz switching frequency.

Real-Time Processor-in-Loop Investigation of a Modified Non-Linear State Observer Using Sliding Modes for Speed Sensorless Induction Motor Drive in Electric Vehicles.

Abstract: Tracking performance and stability play a major role in observer design for speed estimation purpose in motor drives used in vehicles. It is all the more prevalent at lower speed ranges. There was a need to have a tradeoff between these parameters ensuring the speed bandwidth remains as wide as possible. This work demonstrates an improved static and dynamic performance of a sliding mode state observer used for speed sensorless 3 phase induction motor drive employed in electric vehicles (EVs). The estimated torque is treated as a model disturbance and integrated into the state observer while the error is constrained in the sliding hyperplane. Two state observers with different disturbance handling mechanisms have been designed. Depending on, how they reject disturbances, based on their structure, their performance is studied and analyzed with respect to speed bandwidth, tracking and disturbance handling capability. The proposed observer with superior disturbance handling capabilities is able to provide a wider speed range, which is a main issue in EV. Here, a new dimension of model based design strategy is employed namely the Processor-in-Loop. The concept is validated in a real-time model based design test bench powered by RT-lab. The plant and the controller are built in a Simulink environment and made compatible with real-time blocksets and the system is executed in real-time targets OP4500/OP5600 (Opal-RT). Additionally, the Processor-in-Loop hardware verification is performed by using two adapters, which are used to loop-back analog and digital input and outputs. It is done to include a real-world signal routing between the plant and the controller thereby, ensuring a real-time interaction between the plant and the controller. Results validated portray better disturbance handling, steady state and a dynamic tracking profile, higher speed bandwidth and lesser torque pulsations compared to the conventional observer.

An efficient flux weakening control strategy of a speed controlled permanent magnet synchronous motor drive for light electric vehicle applications

Abstract: In this proposed work an efficient flux weakening control strategy of a four quadrant speed controlled Surface Mounted Permanent Magnet Synchronous Motor drive is presented Permanent magnet synchronous motors are extensively used in light electric vehicle applications because it has large power density, high torque to inertia ratio, lower excitation losses and higher efficiency In this proposed concept for speed controlled drive PWM current controller and PI speed controller is taken into consideration For the implementation of such flux weakening control scheme a vector controlled surface mounted PMSM drive is established It is emphasized that demagnetizing component of the d-axis current is introduced into the stator current Therefore the proposed approach establishes better dynamic as well as steady state drive performance for high speed and energy efficient light electric vehicle applications Hence a novel and efficient flux weakening control strategy is achievable

Modified spwm technique for improved harmonic performance of single pv array fed grid-tied five-level converter

Abstract: This study presents a performance assessment of a single photovoltaic (PV) array fed transformer-based five-level converter topology with optimal shift factor-based modified sinusoidal pulse width modulation (OSF-MSPWM) technique under a dynamic solar PV environment. The five-level converter output is generated using H bridge cells and single-phase transformers. A single PV array is fed to all cascaded H bridge cells and isolation is provided by cascading secondary windings of the transformers in the AC side. The separate DC sources requirement is eliminated and galvanic isolation is provided by single-phase transformers. The decoupled controller with modified in-phase disposition PWM technique is used for active power injection into the grid at unity power factor. This work uses a new carrier shape at the same input carrier frequency and modulation index m f for improving the harmonics performance of the five-level converter. Hence, shift the dominant harmonics to the higher side for developed topology and performing optimal shift factor-based modulation is compared with the conventional SPWM technique. The steady-state and dynamic responses of the PV multilevel converter are observed in MATLAB simulation and tested in a real-time platform.

Unipolar Single Reference Multicarrier Sinusoidal Pulse Width Modulation Based 7-level Inverter with Reduced Number of Semiconductor Switches for Renewable Energy Applications

Abstract: In the present scenario of increasing power demand and depletion of fossil fuel results in the research advancements in the field of renewable energy sources. Among various types of renewable energy sources, photovoltaic related applications are gaining importance. DC-AC converters play a very prominent role in photovoltaic system in efficient power delivering for various applications. This paper proposed a 7-level inverter with reduced number of switches for photovoltaic applications. Unipolar Single Reference Multicarrier Sinusoidal Pulse Width Modulation (U-SR-MC-SPWM) technique is used for the purpose of gate pulse generation for the proposed multilevel inverter. A comparative study of seven-level cascaded multilevel inverter and a proposed multilevel inverter is carried out. Simulation and power quality analyses of both multilevel inverters are performed in MATLAB/Simulink platform version 2016(a). It is noticed that the total harmonic distortion is slightly more of the proposed multilevel inverter when compared with cascaded h-bridge inverter. But, with the reduction in the number of power semiconductor switches in proposed multilevel inverter overall switching power losses, circuit complexity, gate driver requirements and cost of the system can be reduced. The simulation results always show a good agreement with the proposed approach.

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