Abstract We have developed the new SPORT HYBRID SH-AWD system, a hybrid system that provides best in class fuel economy and drivability to exceed customer expectations. The powertrain has a V6 engine and comes with three drive types modes: front wheel drive powered by a 7-speed dual clutch transmission with one built-in motor, rear wheel drive powered by a twin motor unit with two built-in motors, and all-wheel drive powered by a combination of the two. The system can automatically select the most efficient drive method for the driver's needs and the road conditions. The two motors built into the twin motor unit are individually controlled and torque vectoring is used to create a torque difference between the left and right tires, improving the turning performance. The electric drive system was developed with consideration for layout feasibility and quietness. The two motors built into the twin motor unit and the inverter that drives the motors have been newly developed. By installing this system in the 2015 model year RLX, we achieved engine performance equivalent to a car with a V8 engine at 0-60 mph in 5.4sec and fuel economy equivalent to a car with an L4 engine at 30 mpg. Introduction Honda has already launched several hybrid car systems such as the SPORT HYBRID i-MMD and SPORT HYBRID i-DCD that not only provide excellent fuel economy but make driving more enjoyable than ever before.Now we have developed a new and even better system: the SPORT HYBRID SH-AWD system. The constituent parts of the electric drive (E-Drive) system are adapted to suit the system, with minimal noise and an optimized mounting layout and cooling, while also maintaining commonality with other systems. This report provides and overview of the system as a whole and the E-Drive system technology that comprises the system, including the newly developed rear motor, inverters and intelligent power unit (IPU). 1. System Overview Figure 1 shows the concept of this system. Figure 1. System concept We aim to achieve equivalent driving performance to a car with a V8 engine and fuel economy equivalent to a car with an L4 engine by combining a V6 engine and the E-Drive systemElectric Drive System for SPORT HYBRID SH-AWD 2014-01-1821 Published 04/01/2014 Koichi Ono Honda R&D Co., Ltd. CITATION: Ono, K., "Electric Drive System for SPORT HYBRID SH-AWD," SAE Technical Paper 2014-01-1821, 2014, doi:10.4271/2014-01-1821. Copyright © 2014 SAE InternationalDownloaded from SAE International by Tsinghua University, Wednesday, February 20, 2019Independent control of the left and right rear tires also allows torque vectoring of the wheels for intuitive handling. Figure 2 shows the hardware configuration of this system. Figure 2. Hardware configuration The direct injection engine is optimized for use in this system. It is placed in the front engine room in a combination with the Motor-integrated 7-Speed DCT (Dual Clutch Transmission). The twin motor unit (TMU) with two built-in motors that drives the rear tires is mounted in the rear sub-frame. The three inverters that drive the motors are mounted in the center console in the cabin. The IPU that comprises the parts that store the electric energy, such as the high-power lithium ion battery, DC/DC converter, motor control unit and battery control unit, is placed back of the rear seat. Table 1 shows system specifications. Table 1. System specifications 2. Driving Performance The engine and the two motors built into the TMU provide a total maximum system power of 281kW(377 hp).Figure 3 shows the acceleration performance of the car. The indexes for both the 0-60 mph starting acceleration performance and the 50-70 mph mid-range acceleration performance are equal to or better than competitors' cars with V8 engines. Figure 3. Driving performance compared to competitors We also took into consideration at the acceleration performance in urban areas. Figure 4 shows the acceleration performance from low