Development of a Parallel Hybrid System for RWD Vehicles

In December 2006, Nissan announced its Nissan Green Program 2010 (NGP 2010), a mid-term environmental action plan that includes initiatives to reduce vehicle emissions. In line with this plan, the company intends to introduce a new and original hybrid system in fiscal year 2010. Specifically, this system-called the "Infiniti Direct Response Hybrid"-is a one-motor, two-clutch parallel hybrid system that eliminates the need for a torque converter. It will be featured in the 2012 Infiniti M35 Hybrid and provides the following advantages. 1. Significant improvement in fuel economy even in Highway driving 2. Better response and a more direct feeling 3. Lightweight and low cost This one-motor, two-clutch system without torque converter possesses a simple but highly capable architecture that is new to the passenger vehicle segment. The successful development of this system hinged on breakthroughs in the following areas. 1. High speed control of switching between charging/discharging 2. Immediate and high-output power assist 3. Smoothness at engine start Nissan has developed the following proprietary technologies to realize the development of this system. High-output and high-speed lithium-ion battery Innovative high-speed and precise motor control This paper provides an outline and description of this new one-motor, two-clutch parallel hybrid system as well as the key breakthrough technologies that made it possible.