J. Vanishree

Bio: J. Vanishree is an academic researcher from VIT University. The author has contributed to research in topics: Inverter & Alternative energy. The author has an hindex of 2, co-authored 4 publications receiving 13 citations.

Dynamic Modelling of a Wind/Fuel-Cell/Ultra-Capacitor-Based Hybrid Power Generation System

Abstract: Recent research and development of alternative energy sources have shown excellent potential as a form of contribution to conventional power generation systems. In order to meet sustained load demands during varying natural conditions, different energy sources and converters need to be integrated with each other for extended usage of alternative energy. The paper focuses on the combination of wind, Fuel Cell (FC) and Ultra-Capacitor (UC) systems for sustained power generation. As the wind turbine output power varies with the wind speed: an FC system with a UC bank can be integrated with the wind turbine to ensure that the system performs under all conditions. A dynamic model, design and simulation of a wind/FC/UC hybrid power generation system with power flow controllers is proposed. In the proposed system, when the wind speed is sufficient, the wind turbine can meet the load demand. If the available power from the wind turbine cannot satisfy the load demand, the FC system can meet the excess power demand, while the UC can meet the load demand above the maximum power available from the FC system for short durations. Furthermore, this system can tolerate the rapid changes in wind speed and suppress the effects of these fluctuations on the equipment side voltage in a novel topology.

Model Predictive Control of Quasi-Z-Source Inverter

Abstract: This paper provides an overview simulation and brief discussion about model predictive control of quasi-z-source inverter in shoot-through case and also non-shoot-through case. Model predictive control strategy related with different tasks related to closed-loop control of voltages and currents such as current across inductor and voltage across capacitor provides high dynamic performance and is useful toward controlling of power converters and drives. The steady-state and transient conditions are analyzed for both buck and boost case with experimental results. This approach improves overall performance of inverter and reduces switching losses of inverter.

Ultracapacitors: Why, How, and Where is the Technology

Abstract: The science and technology of ultracapacitors are reviewed for a number of electrode materials, including carbon, mixed metal oxides, and conducting polymers. More work has been done using microporous carbons than with the other materials and most of the commercially available devices use carbon electrodes and an organic electrolytes. The energy density of these devices is 3¯5 Wh/kg with a power density of 300¯500 W/kg for high efficiency (90¯95%) charge/discharges. Projections of future developments using carbon indicate that energy densities of 10 Wh/kg or higher are likely with power densities of 1¯2 kW/kg. A key problem in the fabrication of these advanced devices is the bonding of the thin electrodes to a current collector such the contact resistance is less than 0.1 cm2. Special attention is given in the paper to comparing the power density characteristics of ultracapacitors and batteries. The comparisons should be made at the same charge/discharge efficiency.

A Review of Modulation and Control Techniques for Multilevel Inverters in Traction Applications

Abstract: Traction inverter has been the subject of many studies due to its essential role in the proper performance of the drive system. With the recent trend in increasing the input voltage in battery-powered electric vehicles, multilevel inverters have been proposed in the literature as a promising substitute for conventional two-level traction inverters. A critical aspect of utilizing multilevel structures is employing proper control and modulation techniques. The control system structure must be capable of handling a number of key issues, like capacitor voltage balancing and equal power loss sharing, which arise in multilevel topologies. This paper presents a review of the present-day traction drive systems in the industry, control and modulation techniques for multilevel structures in the inverters, as well as the principal challenges that need to be addressed in the control stage of the multilevel traction inverter. A comparison has been made between different methods based on the most important criteria and requirements of the traction drive system. Finally, future trends in this application are presented and some suggestions have been made for the next generation of traction drives.

Modeling a photovoltaic energy storage system based on super capacitor, simulation and evaluation of experimental performance

Abstract: Photovoltaic energy is very important to meet the consumption needs of electrical energy in remote areas and for other applications. Energy storage systems are essential to avoid the intermittent production of photovoltaic energy and to cover peaks in energy demand. The super capacitor, also known as electrochemical double layer capacitor, is a storage device which has a very high power density compared to conventional battery and is capable of storing a large amount of electrical energy in short time periods, which reflects its interest to be used for the storage of photovoltaic energy. From this principle, this paper represents a three-branch RC model of super capacitor to describe its different dynamics of operation during the charging, discharging and rest phases. After having validated the good functioning of this model with the experimental study of Zubieta, The super capacitor performance has been demonstrated and compared with a conventional battery in a photovoltaic converter chain to power AC machine.

Adaptive neuronal induction motor control with an 84‐pulse voltage source converter

Abstract: This paper deals with the problem of harmonic distortion in velocity control drives for large horsepower three‐phase induction motors. A new solution alternative to considerably reduce har...

Design, Analysis, and Comparison of Control Strategies for an Industrial Robotic Arm Driven by a Multi-Level Inverter

Abstract: In this article, we present the design and implementation of different control strategies for the position of a 2-Degree-of-Freedom (DoF) robotic arm, namely gain scheduling per trenches, gain scheduling by interpolation, adaptive control, and fuzzy logic. The first link of this robot is driven by an Alternating Current Brushless Permanent Magnet Motor (ACBPMM) through a three-phase multi-level inverter with 27 levels of voltage per phase. Thanks to the topologies offered by ACBPMMs and to the multi-level inverter, high commutation frequencies are reduced, as observed in the computer simulations. Additionally, to determine which proposed control strategies are the most suitable for an ACBPMM connected to a multi-level inverter, a comparative study on the performance of the controllers implemented for this robot is conducted.