Yadav Parikshit
Email Address
eleyp@nus.edu.sg
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Publication Improved harmony search algorithm based optimal design of the brushless DC wheel motor(2010) Yadav, P.; Kumar, R.; Panda, S.K.; Chang, C.S.; ELECTRICAL & COMPUTER ENGINEERINGThe paper presents an optimal design method to optimize the efficiency of the brushless DC wheel motor. The optimal design of a brushless DC wheel motor is a nonlinear multimodal benchmark optimization problem. Hence, conventional methods fail to provide optimal solution. Recently developed, Harmony Search (HS) algorithm has been used for maximizing the efficiency of the brushless DC wheel motor by optimally designing the design parameters. HS algorithm is music based meta-heuristic optimization method which is analogous with the music improvisation process where musician continues to polish the pitches in order to obtain better harmony. Furthermore an Improved Harmony Search (IHS) method for generating new solution vectors that enhances accuracy and convergence rate of HS has been employed. The numerical results obtained show that the efficiency of the brushless DC wheel motor is more for IHS algorithm when compared to HS algorithm and GA. However, the motor based on the design parameters obtained using IHS is subjected to lesser temperature rise for the same efficiency as compared to that of Ant Colony Optimization (ACO) and also IHS algorithm converges faster than other meta-heuristic approaches adopted in this paper. ©2010 IEEE.Publication An Intelligent Tuned Harmony Search algorithm for optimisation(2012) Yadav, P.; Kumar, R.; Panda, S.K.; Chang, C.S.; ELECTRICAL & COMPUTER ENGINEERINGThe Harmony Search (HS) algorithm is a population-based metaheuristic optimisation algorithm. This algorithm is inspired by the music improvisation process in which the musician searches for harmony and continues to polish the pitches to obtain a better harmony. Although several variants of the HS algorithm have been proposed, their effectiveness in dealing with diverse problems is still unsatisfactory. The performances of these variants mainly depend on the selection of different parameters of the algorithm. In this paper, a new variant of the HS algorithm is proposed that maintains a proper balance between diversification and intensification throughout the search process by automatically selecting the proper pitch adjustment strategy based on its Harmony Memory. However, the performance of the proposed Intelligent Tuned Harmony Search (ITHS) algorithm is influenced by other parameters, such as the Harmony Memory Size (HMS) and the Harmony Memory Considering Rate (HMCR). The effects that varying these parameters have on the performance of the ITHS algorithm is also analysed in detail. The performance of the proposed ITHS algorithm is investigated and compared with eight state-of-the-art HS variants over 17 benchmark functions. Furthermore, to investigate the robustness of the proposed algorithm at higher dimensions, a scalability study is also performed. Finally, the numerical results obtained reflect the superiority of the proposed ITHS algorithm in terms of accuracy, convergence speed, and robustness when compared with other state-of-the-art HS variants. © 2012 Elsevier Inc. All rights reserved.Publication Investigation of current harmonics in thruster AC drives in oil-rig platforms(2009) Yadav, P.; Cheah, C.W.; Allana, A.S.; Lye, T.; Chang, C.S.; Panda, S.K.; Sahoo, S.K.; ELECTRICAL & COMPUTER ENGINEERINGThe paper investigates the effect of current harmonics in oil-rig's thruster drives, which are based on variable frequency AC induction motor drives. The electrical system in the oil rig consists of two 12 pulse phase shifting transformers having a relative phase shift of 15°, a frequency converter and an induction motor. The electrical system exhibits clean energy characteristics according to IEEE. Std 519.1992 with I-THD of 2.48% and harmonics of the order of 24n±1 at the busbar when both transformers are equally loaded. Due to the nonlinear nature of diode bridge rectifier and dc link capacitors, the input line currents are highly distorted and contain significant amount of low order harmonics causing overheating of the transformer. To investigate the effect of harmonics on the transformer, the mathematical model of the electrical system of oil rig and thermal model of the three windings dry transformer is developed in MATLAB. The temperature rise in the transformer is calculated using IEEE. Std C57.12.91.2001. The test results are investigated and to increase the thermal capability of the transformer, K-factor is calculated and transformer is derated accordingly. The temperature rise decreases with the derating of the transformer and the transformer can now be loaded beyond the nameplate rating upto 1.2 pu load without overheating.Publication Energy-efficient thrust allocation for semi-submersible oil rig platforms using improved harmony search algorithm(2012) Yadav, P.; Kumar, R.; Panda, S.K.; Chang, C.S.; ELECTRICAL & COMPUTER ENGINEERINGIn this paper, the thrust allocation problem for semi-submersible oil rig platform is formulated as an optimization problem, with an objective to minimize the power consumption. The electrical power consumed by the oil rig platform depends on the thrust generated by the thrusters and the efficiency of the electrical propulsion system. A detailed mathematical model to compute the efficiency of the electrical propulsion system is developed and the numerical results obtained are compared with experimental test results. The formulated energy-efficient thrust allocation problem is solved using Improved Harmony Search (IHS) algorithm. The percentage savings in total power consumption for the oil rig platform as compared to the Mincon method for Genetic Algorithm (GA), Harmony Search (HS), and IHS methods are 48.76%, 51.13%, and 53.90%, respectively. In addition, the total power consumption for energy-efficient thrust allocation approach is lesser as compared to conventional thrust allocation approach for all the considered algorithms. © 2012 IEEE.Publication Real-time implementation of a harmony search algorithm-based clustering protocol for energy-efficient wireless sensor networks(2014) Hoang, D.C.; Yadav, P.; Kumar, R.; Panda, S.K.; ELECTRICAL & COMPUTER ENGINEERINGIn real-life applications of wireless sensor networks (WSNs), optimization of the network operation is required to extend its lifetime. A framework is proposed that enables practical development of centralized cluster-based protocols supported by optimization methods for the WSNs. Based on this framework, a protocol using harmony search algorithm (HSA), a music-based meta-heuristic optimization method, is designed and implemented in real time for the WSNs. It is expected to minimize the intra-cluster distances between the cluster members and their cluster heads (CHs) and optimize the energy distribution of the WSNs. The study of HSA cluster-based protocol is carried out in a real case where the WSNs equipped with the proposed protocol are deployed in an indoor environment to monitor the ambient temperature for fire detection. A comparison is made with the well-known cluster-based protocols developed for WSNs such as low-energy adaptive clustering hierarchy-centralized (LEACH-C) and a cluster-based protocol using Fuzzy C-Means (FCM) clustering algorithm. Experimental results demonstrate that the proposed protocol using HSA can be realized in centralized cluster-based WSNs for safety and surveillance applications in building environments. From the obtained experimental test results, it can be seen that the WSNs lifetime has been extended using the proposed HSA protocol in comparison with that of LEACH-C and FCM protocols. © 2005-2012 IEEE.Publication Optimization of the power generation scheduling in oil-rig platforms using genetic algorithm(2010) Yadav, P.; Kumar, R.; Panda, S.K.; Chang, C.S.; ELECTRICAL & COMPUTER ENGINEERINGThe paper focuses on the optimal scheduling of the diesel generators in the oil rig platform for the fuel optimization problem. The Specific Fuel Consumption (SFC) of the Diesel Generator is not properly modeled in the literature. An accurate model of SFC using cubic spline interpolation method is also presented. Optimization of fuel consumption at various loading conditions has been analyzed with efficient use of load scheduling of the diesel generators. The SFC model consists of discrete and non linear equations and hence conventional method fail to provide optimal solution. The Genetic Algorithm (GA) is proposed for the optimum load scheduling of diesel generators of both equal and unequal ratings. A comparison of all the methods is also presented to obtain the probable optimal solution of the problem. It is concluded that proposed SFC model is more accurate and GA gives better results than conventional methods. The proposed schemes can be used in marine power plant design and are equally applicable for any other technology. © 2010 IEEE.Publication A robust harmony search algorithm based clustering protocol for wireless sensor networks(2010) Hoang, D.C.; Yadav, P.; Kumar, R.; Panda, S.K.; ELECTRICAL & COMPUTER ENGINEERINGOptimizing energy consumption is the main concern for designing and planning the operation of the Wireless Sensor Networks (WSNs). Clustering technique is one of the methods utilized to extend lifetime of the network by applying data aggregation and balancing energy consumption among sensor nodes of the network. In this paper, we propose the recently developed, Harmony Search Algorithm (HSA) for minimizing the intra-cluster distance and optimizing the energy consumption of the network. HSA is music based metaheuristic optimization method which is analogous with the music improvisation process where musician continue to polish the pitches in order to obtain better harmony. A comparison is made with the well known cluster-based protocol approach developed for WSNs known as Low-Energy Adaptive Clustering Hierarchy (LEACH), heuristic optimization algorithms like Particle Swarm Optimization (PSO) and Genetic Algorithm(GA) as well as the traditional K-means and Fuzzy C-Means (FCM) clustering algorithms. Simulation results demonstrate that the proposed protocol using HSA can reduce energy consumption and improve the network lifetime. ©2010 IEEE.Publication An Improved Harmony Search algorithm for optimal scheduling of the diesel generators in oil rig platforms(2011-02) Yadav, P.; Kumar, R.; Panda, S.K.; Chang, C.S.; ELECTRICAL & COMPUTER ENGINEERINGHarmony Search (HS) algorithm is music based meta-heuristic optimization method which is analogous with the music improvisation process where musician continue to polish the pitches in order to obtain better harmony. The paper focuses on the optimal scheduling of the generators to reduce the fuel consumption in the oil rig platform. The accurate modeling of the specific fuel consumption is significant in this optimization. The specific fuel consumption has been modeled using cubic spline interpolation. The SFC curve is non-linear and discrete in nature, hence conventional methods fail to give optimal solution. HS algorithm has been used for optimal scheduling of the generators of both equal and unequal rating. Furthermore an Improved Harmony Search (IHS) method for generating new solution vectors that enhances accuracy and convergence rate of HS has been employed. The paper also focuses on the impacts of constant parameters on Harmony Search algorithm. Numerical results show that the IHS method has good convergence property. Moreover, the fuel consumption for IHS algorithm is lower when compared to HS and other heuristic or deterministic methods and is a powerful search algorithm for various engineering optimization problems. © 2010 Elsevier Ltd. All rights reserved.