Akhil Prasad

Bio: Akhil Prasad is an academic researcher from VIT University. The author has contributed to research in topics: Electric power system & AC power. The author has an hindex of 2, co-authored 6 publications receiving 12 citations.

Application of Cubic Spline Interpolation Technique in Power Systems: A Review

Abstract: In this chapter, a comprehensive review is made on the application of cubic spline interpolation techniques in the field of power systems. Domains like available transfer capability (ATC), electric arc furnace modeling, static var. compensation, voltage stability margin, and market power determination in deregulated electricity market are taken as samples to illustrate the significance of cubic spline interpolation.

An efficient DC grid based PV — wind power generation using modified P&O tracking technique

Abstract: This paper focuses on efficient hybrid microgrid which consists of wind and solar power generating sources with an efficient and reliable grid connection. The proposed system will execute modified Perturb and observe maximum power point tracking technique for both wind and solar generating unit to maximize the simultaneous extraction of energy from the entire power generation unit under different weather and load conditions. This system eliminates the need to synchronize the system frequency, phase and voltage, which allows flexible operation of multiple parallel connected wind and solar generators at the grid. The simulation output of proposed system will be demonstrated under different weather and load conditions.

Impact of Generator/Demand Constraints on Market Clearing Price under Pool Market with Elastic Demand

Abstract: In recent years, state electricity boards are getting transformed towards the restructuring process. It has brought lot of challenges in market environment. The main objective of deregulation is to provide competition and opens new choices to benefit the consumers. In this competitive environment, determination of Market Clearing Price (MCP) is the main aim of a pool operator. Its goal is to maximize the societal welfare function i.e. both Gencos’ and the Discos’ have to get benefited. In this paper, instead of taking stepped bid function from the generators and consumers, quadratic bid functions are taken as an input and the impact of MCP on generator limits has been investigated with and without losses.

Assessment on various node voltage stability indices — A review

Abstract: With the surge in demand for electrical energy and the consequent need to operate the power system close to its limits, the need to compute the voltage stability limit and the system's proximity to this limit has become mandatory. Among the methods to compute these parameters, the Voltage Stability Indices stand out owing to their attributes of simplicity and minimal computational effort and have also served varied applications. This paper presents a review on Node Voltage Stability Indices with respect to approach, values at critical point, deviation from critical point value, accuracy and response at different power factors via graphical means. The results and conclusions presented in this paper have been arrived at by performing the computations on IEEE 30 Bus system on MATLAB 8.0R 2012b environment.

Critical Review on PV MPPT Techniques: Classical, Intelligent and Optimisation

Abstract: Maximum power extraction from the photovoltaic (PV) system plays a critical role in increasing efficiency during partial shading conditions (PSC's). The higher cost and low conversion efficiency of the PV panel necessitate the extraction of the maximum power point (MPP). So, a suitable maximum power point tracking (MPPT) technique to track the MPP is of high need, even under PSC's. This study gives an extensive review of 23 MPPT techniques present in literature along with recent publications on various hardware design methodologies. MPPT classification is done into three categories, i.e. Classical, Intelligent and Optimisation depending on the tracking algorithm utilised. During uniform insolation, classical methods are highly preferred as there is only one peak in the P–V curve. However, under PSC's, the P–V curve exhibits multiple peaks, one global MPP (GMPP) and the remaining are local MPPs. Hence, Intelligent and Optimisation techniques came into limelight to differentiate the GMPP out of all LMPPs. Every MPPT technique has its advantages and limits, but a streamlined MPPT is drafted in numerous parameters like sensors required, hardware implementation, tracking in PSC's, cost, tracking speed and tracking efficiency. This present study aimed to address the advancement in this area for further research.

Online TTC Estimation Using Nonparametric Analytics Considering Wind Power Integration

Abstract: Total transfer capability (TTC) is an effective indicator to evaluate the transmission limit of the interconnected systems. However, due to the large-scale wind power integration, operation conditions of a power system may change rapidly, yielding time-varying characteristics of the TTC. As a result, the traditional time-consuming transient stability constrained TTC model is unable to assess the online transmission margin. In this paper, we propose an online measurement-based TTC estimator using the nonparametric analytics. It consists of three major components: the probabilistic data generation, the composite feature selection, and the group Lasso regression-based training scheme. Specifically, we present a probabilistic data generation approach to take into account the uncertainties of the day-ahead generation scheduling and to reduce the number of redundant or infeasible data. Then, the composite feature selection is used to reduce the dimension of the generated data and identify the features which are highly correlated with TTC. The features are determined by the maximal information coefficients and nonparametric independence screening approach. Finally, these selected features are trained by the group Lasso regression to learn the correlation between the TTC and the online measurements. Once real-time measurements are available, the TTC can be assessed immediately through the learned correlation relationship. Extensive numerical results carried out on the modified New England 39-bus test system demonstrate the feasibility of the proposed TTC estimator for online applications.

Dynamics of Excitons in Conjugated Molecules and Organic Semiconductor Systems.

Abstract: The exciton, an excited electron-hole pair bound by Coulomb attraction, plays a key role in photophysics of organic molecules and drives practically important phenomena such as photoinduced mechanical motions of a molecule, photochemical conversions, energy transfer, generation of free charge carriers, etc. Its behavior in extended π-conjugated molecules and disordered organic films is very different and very rich compared with exciton behavior in inorganic semiconductor crystals. Due to the high degree of variability of organic systems themselves, the exciton not only exerts changes on molecules that carry it but undergoes its own changes during all phases of its lifetime, that is, birth, conversion and transport, and decay. The goal of this review is to give a systematic and comprehensive view on exciton behavior in π-conjugated molecules and molecular assemblies at all phases of exciton evolution with emphasis on rates typical for this dynamic picture and various consequences of the above dynamics. To uncover the rich variety of exciton behavior, details of exciton formation, exciton transport, exciton energy conversion, direct and reverse intersystem crossing, and radiative and nonradiative decay are considered in different systems, where these processes lead to or are influenced by static and dynamic disorder, charge distribution symmetry breaking, photoinduced reactions, electron and proton transfer, structural rearrangements, exciton coupling with vibrations and intermediate particles, and exciton dissociation and annihilation as well.

Maximum Power Point Tracker (MPPT) for Photovoltaic Power Systems-A Systematic Literature Review

Abstract: Photovoltaic (PV) as a renewable source of energy plays a significant role in generating electricities in the industry and distributed consumers. The output power of the PV device is highly nonlinear which is dependent on I-P and V-P characteristics of the device and also irradiation conditions. Therefore, many research works have been performed to optimize the performance and obtain maximum power from the PV panels. This paper provides a brief literature review on maximum power point tracker (MPPT) for the PV panels. For this purpose, the PV circuit structure with its mathematics model is presented. Then, recent publications on various design methodologies are reviewed.