1. INTRODUCTION Recently, the market penetration of electrically driven vehicles is proceeding at a rapid pace, and application is expanding from compact vehicles to heavy-duty vehicles. The driving systems used in these vehicles are subject to constant demands for high torque, high power and high efficiency in order to realize good power performance and fuel economy. On the other hand, system size and weight reduction is needed to realize a system with high general flexibility for expansion to multiple models. Honda’s Intelligent Multi-Mode Drive (i-MMD) system uses two motors for driving and electric power generation. The driving motor provides power performance and the generating motor uses the engine power to generate electricity. Further space saving and high insulation performance are required of each insulating part to meet demands for smaller size and higher voltages. Figure 1 shows the magnet wire and insulation structure of the previous Honda motor and the HAW motor. i-MMD is a high-voltage system with voltages up to 700 V . Figure 1. Comparison of motor structures The conventional motor uses enameled wire and film thickness is 0.1 mm or less. The insulate paper is mainly used to secure inter-phase insulation. The inter-phase electric potential difference is larger than the in-phase electric potential difference, so the film of magnet wire is unable to secure insulation, and insulate paper is added. Increasing film thickness of the magnet wire is a method of achieving insulation performance without increasing the number of parts, and enabled the HAW motor structure. In addition, this method realizes tightly wound Development of High Voltage Wire for New Structure Motor in Full Hybrid Vehicle Kiyoshi Ito, Takumi Shibata, and Takashi Kawasaki Honda R & D Co. Ltd. ABSTRACT Driving motors for hybrid vehicles and electric vehicles require magnet wires that can endure use at high voltages of 650 V or more. The magnet wire is a main motor component with the electromagnetic steel sheets and magnets. Conventional motors generally assure insulation by using the two parts of the magnet wire and insulate paper. But this increases the motor space factor and hinders weight reduction. A new magnet wire with high insulation performance was used by forming thermoplastic resin onto an enameled layer in order to reduce the number of insulating parts and enhance motor performance. The magnet wire (High-V oltage Wire: HVW) composed of polyetheretherketone (PEEK) resin . HVW can withstand the forming load during motor manufacture, secures durability for the automobile motor operating environment (Automatic Transmission Fluid: ATF), high temperatures) and can maintain high-voltage characteristics. The new-structure motor specification that uses this HVW enables a tightly wound circuit structure. Compared to a previous-structure motor with the same core structure, the new motor increases the maximum torque and maximum power by 2.6% and 8.9%, respectively, and reduces the volume and weight by 24% and 26%, respectively. This HVW has been applied to Honda’s new-structure (Honda Advanced Winding: HAW) motor that achieves top-in-class power and compactness. (1) CITATION: Ito, K., Shibata, T., and Kawasaki, T., "Development of High V oltage Wire for New Structure Motor in Full Hybrid Vehicle," SAE Int. J. Alt. Power. 5(2):2016, doi:10.4271/2016-01-1221.2016-01-1221 Published 04/05/2016 Copyright © 2016 SAE International doi:10.4271/2016-01-1221 saealtpow.saejournals.org 272coil-forming without insulate paper, which also enables to reduce the size compared to the conventional distributed winding structure ( Fig. 2). Figure 2. Coil end schematics The motor application technology used HVW (made by Furukawa Electric Co., Ltd,) will be reported. Compared to the previous- structure motor, the developed HVW maintained the same efficiency, and helped to increase the maximum torque and maximum power by 2.6% and 8.9%,