Hibridos

TOYOTA HYBRID SYSTEM

Contents
Introduction ......................................................................................... 1
What is a Hybrid System ? ................................................................. 2
Three Objectives of THS II Development ........................................... 4
How the THS II System Works........................................................... 5
High-voltage systems—motor and generator ..................................... 6
Power Control Unit, Battery and Regenerative Braking System ........ 8
Hybrid Transmission .......................................................................... 10
Engine ............................................................................................... 12
System Control................................................................................. 14
Output Enhancement ........................................................................ 18
In-house Development and Production ............................................ 19
Specifications of New Hybrid System ............................................... 20

The new Prius features THS II, Toyota’snext-generation hibrid technology

Introduction
New levels of environmental & power performance compatibility based on the concept of
Hybrid Synergy Drive

At the 2003 New York Auto Show, TMC President Cho unveiled the
all-new Prius with THS II, a “Hybrid Synergy Drive” concept that delivers
both higher power and greater fuel economy than the previous Prius.

In search of the ultimate eco-carToyota’s mission has always been to provide clean and safe products.
Thus, the company has positioned the environment as one of its most
important issues and has been working toward creating a prosperous
society and a world that is comfortable to live in. With this goal in mind,
Toyota has been actively developing various new technologies from the
perspective of achieving energy security anddiversifying energy sources,
which is necessitated by the dwindling supply of petroleum resources.
For example, in motive power sources for automobiles alone, we have
been continuously improving conventional engines and have developed
and commercialized lean-burn gasoline engines, direct injection
gasoline engines and common rail direct-injection diesel engines, Toyota Hybrid System II (THS II)
etc.We have also been modifying engines so that they can use alternative
fuels, such as compressed natural gas (CNG), instead of gasoline or light oil, and have been installing these engines in commercially
sold vehicles. Toyota has also developed and has been marketing electric vehicles (EV) that use motors for the driving source;
hybrid vehicles (HV) that combine an engine and a motor, fusingthe advantages of these two power sources; fuel cell hybrid
vehicles (FCHV) that use fuel cells (FC) to generate electricity based on a chemical reaction between hydrogen and the oxygen in
the air and that supply this electricity to electric motors to produce driving power.
In January 1997, Toyota declared the start of the Toyota Eco Project. As part of this effort, Toyota decided to tackle theinternational challenge of reducing CO2 emissions in order to prevent global warming and accelerated the development of a hybrid
vehicle with the goal of achieving twice the fuel efficiency of conventional vehicles. Then, in March of the same year, Toyota announced
the completion of a new power train called the Toyota Hybrid System (THS) for use in passenger vehicles. This power train
combinesa gasoline engine and an electric motor, and because it does not require external charging, as do existing electric
vehicles, it works within existing infrastructures such as fueling facilities. This system also achieves nearly twice the fuel efficiency
of conventional gasoline engines.
THS was installed in the passenger vehicle Prius, which was introduced in December 1997 in the Japanese...