THS II (TOYOTA HYBRID SYSTEM II)
HV
Battery
02HTH01TE
: Mechanical Power Path
: Electrical Path
Hybrid
Transaxle
Engine
Compound
Gear Unit
MG1
MG2
Inverter
Assembly
02HTH02TE
Inverter Assembly
Inverter
(DC
AC)
MG1
MG2
Nominal
Voltage of
DC 244.8 V
Boost Converter
Maximum
Voltage of
DC 650 V
HV Battery
TH-3
FEATURES OF THS II
1. General
The THS II offers the following representative features:
- Uses a variable-voltage system in which a boost converter boosts the operating voltage of the system
to a maximum voltage of DC 650 V and an inverter converts the direct current into an alternating
current, which supplies the system voltage to MG1 and MG2.
- A motor speed reduction planetary gear unit, whose purpose is to reduce motor speed, is used to enable
the high-speed, high-output MG2 to adapt optimally to the power split planetary gear unit in the hybrid
transaxle.
The THS II consists primarily of the following components:
2. Variable-voltage System
In the THS II of the ’07 Camry Hybrid model, a boost converter is used inside the inverter assembly. The
boost converter boosts the system operating voltage to a maximum voltage of DC 650 V and the inverter
converts direct current into alternating current, in order to drive MG1 and MG2 at a high voltage as well as
minimize the electrical loss associated with the electric power supply at a smaller current. Thus, MG1 and
MG2 can be operated at high speeds and high output.
