An approach to improve energy performance of electric vehicle: Theoretical evaluation of electric motor winding heat capacity and electrical resistivity using Debye and Bloch-Gruneisen approximations Zafer Dogan a,* , Tural Mehmetoglu b a Department of Electrical Engineering, Faculty of Natural Sciences and Engineering, Gaziosmanpas ‚a University, Tokat, Turkey b Department of Mechatronics Engineering, Faculty of Natural Sciences and Engineering, Gaziosmanpas ‚ a University, Tokat, Turkey article info Article history: Received 10 June 2016 Received in revised form 13 July 2016 Accepted 27 July 2016 Available online xxx Keywords: Electric motors Electrical resistivity Heat capacity Debye model Bloch-Gruneisen theory abstract New analytical accurate approximations to the evaluation temperature dependence of heat capacity and electrical resistivity of motor winding are presented. The approach is based on the Debye method and Bloch-Gruneisen theory for controlling the heat capacity and electrical resistivity of motor winding with variation of temperature. This analytical eval- uation is general and it shows that the results of motor winding heat capacity and re- sistivity are satisfactory for the wide range temperature variations. Comparison of the calculation results with the other literature data show that our approach is accurate and efficient. © 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved. Introduction It is well known that the studies of motor winding heat ca- pacity and electrical resistivity with variation of temperature are very important to control heating and energy losses of electric motors [1e11]. Note that preventing increased motor temperature is one of the challenging processes in motor technology which leads us to decrease energy losses, heating loads, vibrations and winding resistance. There is a long his- tory of systematic attempts to determine the general heating problems of electric motors and prediction of temperature rises of insulation and conducting winding. Unfortunately, they were not entirely successful in the determination of the heating problems of the motors. As is known some motors have conductors made of thicker metals which are used usually copper and sometimes aluminum. Therefore, the * Corresponding author. E-mail addresses: zafer.dogan@gop.edu.tr (Z. Dogan), turalmehmetoglu@yahoo.co.uk (T. Mehmetoglu). Available online at www.sciencedirect.com ScienceDirect journal homepage: www.elsevier.com/locate/he international journal of hydrogen energy xxx (2016) 1 e4 http://dx.doi.org/10.1016/j.ijhydene.2016.07.237 0360-3199/© 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved. Please cite this article in press as: Dogan Z, Mehmetoglu T, An approach to improve energy performance of electric vehicle: Theoretical evaluation of electric motor winding heat capacity and electrical resistivity using Debye and Bloch-Gruneisen approximations, Inter- national Journal of Hydrogen Energy (2016), http://dx.doi.org/10.1016/j.ijhydene.2016.07.237