INTERNATIONAL JOURNAL OF SCIENTIFIC & TECHNOLOGY RESEARCH VOLUME 7, ISSUE 8, AUGUST 2018 ISSN 2277-8616 136 IJSTR©2018 www.ijstr.org Challenging Issues In Wire Less Power Transmission Methods A Survey Paramanand. S. Patil, Satyanarayan. K. Padaganur, Abstract: In this paper we review the potential challenges of the different Wireless power transfer methodologies. The Research of wireless power transfer started in the year 1891 by Nicolas tesla father of wireless power transfer technology this journey continued till today having a lot of research opportunity and challenges in the field of WPT. we discuss the challenging issues with respect to various parameters of wireless power transfer like Cost of transmission. Biological effect, Environmental hazard, & efficiency become more significant parameter. Depending upon the range of transmission there are mainly two methods of WPT known as far field and near field. we discuss the issues with respect to various types of WPT like inductive coupling, resonant inductive coupling, electrostatic induction, & Microwave power transfer (MPT), laser based power beaming, these methods are based on distance classified as near field and far field wireless power transmission. Key words: Wireless power transfer (WPT), near field, far field, Microwave power transfer(MPT),power beaming.resonanat Inductive coupling ——————————  —————————— 1. INTRODUCTION: One of the major issue in power system is losses occurring during transmission and distribution hence increase in the demand of power increases this loss, in india the power loss during transmission distribution is significant around 26%.The main reason for power loss during transmission and distribution is the resistance of wires used for grid. wireless power transmission has became promising solution for this a lot of research is carried for minimizing this loss and to increase the efficiency of transmission, but even this also imposes some challenges like initial cost, health hazard, environmental effect. and efficiency of wireless transmission get reduced for long distance because of diffraction of EM signal. this paper discusses all these issues and survey research publications to find the feasibility of wireless power transmission in practical for coming days.[3] 2. CHALLENGES IN WIRELESS POWER TRANSMISSION METHODS: There are mainly two types of wireless power transfer technology known as near field and far field among these methods we review the potential challenges faced by following WPT technologies [3][4].inductive coupling, resonant inductive couping ,are examples of near field wireless power transmission. Microwave power transmission laser based power beaming are examples far field wireless power transmission. 2.1. Inductive coupling: The principal of mutal inductance that is between two coils transformer is an example of inductive coupling this is suited for only short distance upto few centimeters the drawback is energy decays if distance between transmit coil and reciver coil increases. it employs the method of electromagnetic coupling between two coils[1][3]. Fig.1 shows the inductive copling method of WPT Fig.1:Inductive coupling 2.2 resonanant inductive coupling: in this type of transmission a lot of research is taking place and also proven to be efficient WPT technology for mobile charging ,laptops and many hand held device like tablets, palmtops etc .fig.2 shows such resonant induction charging system A practical wireless power transmission system consisting of a larger rectangular wire loop and a small square wire loop with a parasitic square helical coil is proposed for efficient wireless power transmission in an indoor environment. The effects the non-resonant object such as the conducting box and the human body on the power transmission efficiency and the resonant frequency are investigated numerically The results show that the power transmission efficiency is reduced significantly when a non-resonant object is very close to the receiving element. However this reduction can be negligible when the relative distance between the receiving element and the non resonant is larger than 0.5m or 0.03λ at the resonant frequency of 19.22MHz [7]. Hence in this method also there are potential problems because of near the transmitter some obstacle exists that creates attenuation of power .the efficiency power transfer is very less beyond the distance of 5m .Whether or not it incorporates resonance, induction generally sends power over relatively short distances[8][9]. __________________________________  Paramanand.S.Patil Assistant professor E&C department BLDEACET Bijapur E-mail: paramanand_patil@yahoo.co.in  Satyanarayan.K,Padaganur Assistant professor E&C department BLDEACET Bijapur E-mail: padaganursk@gmail.com