5. Miscellaneous Publications
Permanent URI for this collectionhttps://idr.nitk.ac.in/handle/123456789/13843
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Item Review of preprocessing methods for univariate volatile time-series in power system applications(2021) Ranjan K.G.; Prusty B.R.; Jena D.Outlier detection and correction of time-series referred to as preprocessing, play a vital role in forecasting in power systems. Rigorous research on this topic has been made in the past few decades and is still ongoing. In this paper, a detailed survey of different preprocessing methods is made, and the existing preprocessing methods are categorized. Also, the preprocessing capability of each method is highlighted. The well-established methods of each category applicable to univariate data are critically analyzed and compared based on their preprocessing ability. The result analysis includes applying the well-established methods to volatile time-series frequently used in power system applications. PV generation, load power, and ambient temperature time-series (clean and raw) of different time-step collected from various places/weather zones are considered for index-based and graphical-based comparison among the well-established methods. The impact of change in the crucial parameter(s) values and time-resolution of the data on the methods’ performance is also elucidated in this paper. The pros and cons of methods are discussed along with the scope for improvisation. © 2020Item A Correlative Investigation of Impedance Source Networks: A Comprehensive Review(2021) Reddivari R.; Jena D.In recent times, impedance networks have been developed to overcome the limitations and problems of traditional VSI / CSI and various traditional dc-dc converter networks. From then on, impedance source converters replace the entire range of power electronic converters: dc-dc (converters), dc-ac (inverters), ac-dc (rectifiers), ac-ac frequency regulators (matrix converters). In addition, the impedance source networks are used in a wide range of applications like PV-Grid tied systems, wind energy systems, distributed generations, adjustable speed drives, UPS systems, battery/supercapacitor/flywheel energy storage systems, electric vehicles, electronic loads, and dc circuit breakers, etc. Several topological changes have occurred to improve the performance of conventional ZSIs. This paper provides a concise review of the state-of-the-art impedance source topologies. This paper categorized the impedance topologies based on their functionality, performance improvements, and switching configuration employed. This paper also demonstrates the fundamental structural similarities, advantages, and disadvantages of each topology, which helps the end-users in topology selection. © 2021 IETE.Item A critical review on probabilistic load flow studies in uncertainty constrained power systems with photovoltaic generation and a new approach(2017) Prusty B.R.; Jena D.A power system with large integration of renewable energy based generations is inherently associated with different types of uncertainties. In such cases, probabilistic load flow is a vital tool for delivering comprehensive information for power system planning and operation. Efforts have been made in this paper to perform a critical review on different probabilistic load flow models, uncertainty characterization and uncertainty handling methods, since from its inspection in 1974. An efficient analytical method named multivariate-Gaussian mixture approximation is proposed for precise estimation of probabilistic load flow results. The proposed method considers the uncertainties pertaining to photovoltaic generations and load demands. At the same time, it effectively incorporates multiple input correlations. In order to examine the performance of the proposed method, modified IEEE 118-bus test system is taken into consideration and results are compared with univariate-Gaussian mixture approximation, series expansion based cumulant methods and Monte Carlo simulation. Effect of various correlation cases on distribution of result variables is also studied. The effectiveness of the proposed method is justified in terms of accuracy and execution time. © 2016 Elsevier LtdItem Modeling of photovoltaic system for uniform and non-uniform irradiance: A critical review(2015) Jena D.; Ramana V.V.A critical review on various modeling approaches of photovoltaic array both under uniform and non-uniform irradiance is presented in this paper. The main approaches that have been deliberated are based on the variation of analytical methods, classical optimization techniques and soft computing techniques. The review has been taken from papers published up to 2015. In this paper a detailed description and classifications of modeling techniques for both uniform and non-uniform irradiance conditions are presented. Modeling of PV systems under uniform irradiance is classified into non-iterative methods, iterative methods, artificial intelligence based methods and dynamic models. Under non-uniform irradiance, they are classified into non-iterative methods, iterative methods and artificial intelligence based methods. It is envisaged that this paper can serve as valuable information for researchers to work on photovoltaic array modeling under partial shaded condition. © 2015 Elsevier Ltd. All rights reserved.Item A review of estimation of effective wind speed based control of wind turbines(2015) Jena D.; Rajendran S.This paper provides a comprehensive literature review on the estimation of effective wind Speed (EEWS), and EEWS based control techniques applied to wind turbine (WT). Several numbers of good publications have reported the EEWS based control of wind turbine. Wind speed is a driving force for the wind turbine system. In general wind speed measurement is carried out by anemometer which is located at the top of the nacelle. The optimal shaft speed is derived from the exact measurement of wind speed to extract the optimal power output at below rated wind speed. The wind speed provided by the anemometer is measured at a single point of the rotor plane which is not the accurate effective wind speed. At the same time anemometer increases the overall cost, maintenance and reduce the reliability of the overall system. So an accurate EEWS based control technique is required for WT systems to get the optimal power output. In this paper, a detailed description and classification of EEWS and some EEWS based control techniques have been discussed which is based on control strategy and complexity level of WT system. All most all previous work estimates the wind speed using EEWS techniques such as Kalman filter (KF), extended Kalman filter (EKF), neural network (NN) etc., and then different control techniques are applied. In the last section of this paper integral sliding mode control (ISMC) of a WT at below rated speed region is considered. Operating points are determined by proper estimation of effective wind speed, and modified Newton Raphson (MNR) is employed to estimate this. Finally simulation results are presented with a comparison between proposed ISMC, sliding mode control (SMC) and classical controllers such as aerodynamic torque feed forward (ATF) and indirect speed control (ISC). © 2014 Elsevier Ltd. All rights reserved.