Development of the New 2.0L Hybrid System for Prius

It is necessary for us to reduce CO2 emissions in order to hold down global warming which is advancing year by year. Toyota Motor Corporation believes that not only the introduction of BEVs but also the sale of the hybrid vehicles must spread in order to achieve the necessary CO2 reduction. Therefore, we planned to improve the attractiveness of future hybrid vehicles. Prius has always made full use of hybrid technologies and leading to significant CO2 reduction. Toyota Motor Corporation has developed a 2.0L hybrid system for the new Prius. We built the system which could achieve a comfortable drive along following the customer’s intention while improving the fuel economy more than a conventional system. The engine improves on both output and thermal efficiency. The transaxle decreases mechanical loss by downsizing the differential, and adoption of low viscosity oil. The Power Control Unit (PCU) is downsized by using high frequency for boost conversion and decreases loss by the adoption of Reverse Conducting Insulated Gate Bipolar Transistor (RC-IGBT). In addition, we’ve downsized the battery along with increasing the output power by adopting a new Li-ion battery. We also increased the output power of the E-Four system. This improves turning performance for dry road in addition to improving hill start performance. Moreover, we built in a drive force characteristic that adapts to the new acceleration pedal, therefore, following the customer’s intention.