Prabhakar Tiwari

Bio: Prabhakar Tiwari is an academic researcher from Madan Mohan Malaviya University of Technology. The author has contributed to research in topics: AC power & Photovoltaic system. The author has an hindex of 8, co-authored 38 publications receiving 220 citations. Previous affiliations of Prabhakar Tiwari include Galgotia's College of Engineering and Technology & G H Patel College Of Engineering & Technology.

A survey on impact assessment of DG and FACTS controllers in power systems

Abstract: This paper presents a comprehensive survey on application of various conventional, optimization and artificial intelligence (AI) based computational techniques for impact assessment of optimally placed and coordinated control of distributed generations (DGs) and flexible AC transmission systems (FACTS) controllers in power systems (PSs). This review work is presented from the viewpoint of different performance criterion enhancement of PSs such as minimization of active and reactive power losses and reduction of cost of system, more flexible operation and control, increase overall system energy efficiency, increase reliability of system, relieved transmission and distribution congestion, enhance power quality (PQ) of system, improve the voltage profile (VP), increase the loadability of systems, increase available power transfer capacity (APTC) of system, enhance PS stability, reduce PS oscillations, improve environmental GHG conditions and provide the reactive power support in emergency case such as under fault, sudden change in field excitation of alternators or load increase in PSs. This paper also presents the current status of the various conventional, optimization, and AI computational techniques for optimally placed and coordinated control of DG and FACTS controllers in PSs for enhancement of PSs performance parameters. Authors strongly believe that this survey will be very much useful to the researchers, scientific engineers, industrial persons working in this area to find out the relevant references and current state of the art.

Genetic algorithm for impact assessment of optimally placed distributed generations with different load models from minimum total MVA intake viewpoint of main substation

Abstract: This paper presents the impact assessment of optimally placed different types of distributed generations (DGs) such as DG-1(T1), DG-2 (T2), DG-3 (T3), and DG-4 (T4) with different load models (DMLs) by using genetic algorithm (GA) in distribution power systems (DPSs) from minimum total mega volt ampere (MVA) intake viewpoint of main substation. This paper also presents the impact assessment of optimally placed same kind of DGssuch as DG-2(T2) and DG-4(T4) operating at different power factors (varies from 0.80 to 0.99 leading and lagging, respectively) with DLMs by GA in DPSs from minimum total MVA intake viewpoint of main substation. Different power system (PS) performance indices such as minimization of real power loss, minimization of reactive power loss, improvement of voltage profile, reduction of short circuit current or MVA line capacity and reduction in the emission of environmental greenhouse gases (GHG) such as carbon dioxide (CO2), sulphur dioxide (SO2), nitrogen oxide (NOx) and particulate matters and in emergency like conditions such as under fault, sudden change in field excitation of alternators or load increased in DPSs are calculated. The effectiveness of the proposed methodology is illustrated on IEEE-37 bus distribution test system. This research article is very much useful for practitioners working on the implementation of renewable and building of future electricity grids and also includes the different PS performance indicators from better social welfare, reduced in the environmental pollutants emission, improved the technical issues, reduced the economical burden, and betters the security viewpoints.

Distributed generation planning from power system performances viewpoints: A taxonomical survey

Abstract: This paper presents a taxonomical survey on distributed generation (DG) planning from the distribution power system performances viewpoint. The distribution power system performance indices such as minimization of real power loss index, minimization of reactive power loss index, improvement of voltage profile index, short circuit current capacity index, System Average Interruption Duration Index ( SAIDI), and Customers Average Interruption Duration Index (CAIDI) are consider in this work as major issue in distribution power systems. Such performances can enhance by conventional/traditional devices as well as DG technologies planning such as fuel cell, bio gas, wind turbine, photovoltaic, solar, geo-thermal, tidal and wave etc. In this paper also presents the current status of DG planning in the distribution power systems from the distribution power system performances viewpoints. This survey article is very much useful for scientific person, engineer, industrial person and researchers regarding with DG planning in the distribution power systems from the power system performances viewpoints.

Importance of phase change material (PCM) in solar thermal applications: A review

Abstract: Present study is an attempt to study of different heat storage methods and their application for sustainable development. Solar energy is a prime source of energy which is responsible for other renewable sources directly or indirectly. The major drawback of solar energy is its availability in day time only. Thermal storage devices can overcome this drawback as they can store the energy in day time that can be utilized in off sunshine hours. In the present study classification of thermal storage methods has been done. Further different application of phase change material (PCM) has been discussed. Study shows that PCM can be successfully integrated nearly with all the solar thermal devices. This study will also help to understand to store maximum thermal energy that reduce the requirement of conventional fuels like coal, oil etc. Further, it will help in reducing greenhouse gasses and climatic changes.

Energy management and planning in smart cities

Abstract: A smart city is a sustainable and efficient urban centre that provides a high quality of life to its inhabitants through optimal management of its resources. Energy management is one of the most demanding issues within such urban centres owing to the complexity of the energy systems and their vital role. Therefore, significant attention and effort need to be dedicated to this problem. Modelling and simulation are the major tools commonly used to assess the technological and policy impacts of smart solutions, as well as to plan the best ways of shifting from current cities to smarter ones. This paper reviews energy-related work on planning and operation models within the smart city by classifying their scope into five main intervention areas: generation, storage, infrastructure, facilities, and transport. More-complex urban energy models integrating more than one intervention area are also reviewed, outlining their advantages and limitations, existing trends and challenges, and some relevant applications. Lastly, a methodology for developing an improved energy model in the smart-city context is proposed, along with some additional final recommendations.

Optimal sizing and siting techniques for distributed generation in distribution systems: A review

Abstract: To extract the maximum potential advantages in light of environmental, economical and technical aspects, the optimum installation and sizing of Distributed Generation (DG) in distribution network has always been challenging for utilities as well as customers. The installation of DG would be of maximum benefit where setting up of central power generating units are not practical, or in remote and small areas where the installation of transmission lines or availability of unused land is out of question. The objective of optimal installation of DG in distribution system is to achieve proper operation of distribution networks with minimization of the system losses, improvement of the voltage profile, enhanced system reliability, stability and loadability etc. In this respect analytical (classical) methods, although well-matched for small systems, perform adversely for large and complex objective functions. Unlike the analytical (classical) methods, the intelligent techniques for optimal sizing and siting of DGs are speedy, possess good convergence characteristics, and are well suited for large and complex systems. However, to find a global optimal solution of complex multi-objective problems, a hybrid of two or more meta-heuristic optimization techniques give more effective and reliable solution. This paper presents the fundamentals of DG and DG technologies review the classical and heuristic approaches for optimal sizing and placement of DG units in distribution networks and study their impacts on utilities and customers. An attempt has also been made to compare the analytical (classical) and meta-heuristic techniques for optimal sizing and siting of DG in distribution networks. The present study can contribute meaningful knowledge and assist as a reference for investigators and utility engineers on issues to be considered for optimal sizing and siting of DG units in distribution systems.

Ionosphere and thermosphere: Derivation of TEC and estimation of instrumental biases from GEONET in Japan

Abstract: Abstract. This paper presents a method to derive the ionospheric total electron content (TEC) and to estimate the biases of GPS satellites and dual frequency receivers using the GPS Earth Observation Network (GEONET) in Japan. Based on the consideration that the TEC is uniform in a small area, the method divides the ionosphere over Japan into 32 meshes. The size of each mesh is 2° by 2° in latitude and longitude, respectively. By assuming that the TEC is identical at any point within a given mesh and the biases do not vary within a day, the method arranges unknown TECs and biases with dual GPS data from about 209 receivers in a day unit into a set of equations. Then the TECs and the biases of satellites and receivers were determined by using the least-squares fitting technique. The performance of the method is examined by applying it to geomagnetically quiet days in various seasons, and then comparing the GPS-derived TEC with ionospheric critical frequencies (foF2). It is found that the biases of GPS satellites and most receivers are very stable. The diurnal and seasonal variation in TEC and foF2 shows a high degree of conformity. The method using a highly dense receiver network like GEONET is not always applicable in other areas. Thus, the paper also proposes a simpler and faster method to estimate a single receiver’s bias by using the satellite biases determined from GEONET. The accuracy of the simple method is examined by comparing the receiver biases determined by the two methods. Larger deviation from GEONET derived bias tends to be found in the receivers at lower ( Key words. Ionosphere (mid-latitude ionosphere; instruments and techniques) – Radio science (radio-wave propagation)

Review of distributed generation (DG) system planning and optimisation techniques: Comparison of numerical and mathematical modelling methods

Abstract: An overview of numerical and mathematical modelling-based distributed generation (DG) system optimisation techniques is presented in this review paper. The objective is to compare different aspects of these two broad classes of DG optimisation techniques, explore their applications, and identify potential research directions from reviewed studies. Introductory descriptions of general electrical power system and DG system are first provided, followed by reviews on renewable resource assessment, load demand analysis, model formulation, and optimisation techniques. In renewable resource assessment model review, uncertain solar and wind energy resources are emphasised whereas applications of forecasting models have been highlighted based on their prediction horizons, computational power requirement, and training data intensity. For DG optimisation framework, (solar, wind and tidal) power generator, energy storage and energy balance models are discussed; in optimisation technique section, both numerical and mathematical modelling optimisation methods are reviewed, analysed and criticised with recommendations for their improvements. In overall, this review provides preliminary guidelines, research gaps and recommendations for developing a better and more user-friendly DG energy planning optimisation tool.