New model Optima (TF HEV) Technical Service Training book (Link tải bản full ở file đính kèm)

Chapter 1. Introduction of TF
HEV(Hybrid Electric Vehicle)
Preface
1. Hybrid Electric Vehicle
2. Optima Hybrid System Overview
3. Optima Hybrid Control Mode

Copyright ⓒ 2009~2010 All rights reserved. No part of this material may be reproduced, stored in any retrieval system or transmitted in any form or by any means without the written permission of Kia Motors Corporation.


Chapter 1. Introduction of TF HEV

Preface

Learning
Objectives

1. Describes overall summary about Hybrid
Electric Vehicle (HEV).
2. Details the definition of Hybrid.
3. Describes the Hybrid System categories.

The concept vehicle development project began in 1995, and by 2008, Kia Motor Company
launched pilot production of hybrid vehicles for the Gets and Rio models. In 2009, the TD
Spectra model with LPI technology and lithium polymer battery was launched as the world’s
first LPI hybrid vehicle. Following the TD Spectra, the Optima Hybrid Electric Vehicle is going
to be launched. The Optima HEV is a full-type hybrid with electric drive mode. It boasts
excellent fuel efficiency and power that stands shoulder-to-shoulder with the world’s leading
hybrid vehicles.

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Chapter 1. Introduction of TF HEV

1. Hybrid Electric Vehicle
1.1 Why HEV?

Atmospheric Pollution

Strict Emission Gas Regulation
CARB
EURO

Low Pollution
Vehicle Ratio
Regulation

Environmentally Friendly Vehicles

Global Warming

Energy Crisis

High Efficiency Power-train / Development of alternative energy
New Concept Power-train
- Electricity: Electric Vehicle, Fuel Cell
Vehicle
- Hybrid: HEV, Fuel Cell HEV

Hybrid Electric Vehicle / Electric Vehicle / Fuel Cell Vehicle

Global automotive companies are making significant investments in developing new concept
automobiles that deliver high efficiency output with low emission. This trend is in line with worldwide
efforts to develop alternative energy in preparation for depleting petroleum resources, as well as to
reduce CO2 emission with strict environmental pollution regulations that call for reduced NOx and
measures against global warming. The world faces depletion of fossil fuel energy resources in the 21 st
Century, and with increasing concern about global warming, there is an urgent need to develop vehicles
that have reduced carbon dioxide emission and conform to the emission control regulations pertaining
to nitrogen oxide and hydrocarbon.
The state of California has forced major automobile manufacturers to produce a minimum of 2% of all
vehicles as pollution-free automobiles. Such strict regulation is anticipated to spread throughout
America. And the gasoline-powered vehicles is anticipated to fade into the history by 2030.
Encouragingly, the market for hybrid vehicles is increasing and is forecast to account for 24% of the
entire automobile market by 2010, a figure increasing to almost 50% by 2030.
Such reality is causing the global automotive industry to focus on hybrid vehicles with dual power
sources as the next generation of automobiles.
Developing hybrid vehicles is not an option but a necessity for automobile manufacturers to ensure a
sustainable future with ever strengthening environmental regulations worldwide.

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Chapter 1. Introduction of TF HEV

1.2 What is HEV?

Electric Motor / Battery

Gasoline Engine / Diesel Engine
+

A Hybrid Electric Vehicle (HEV) is a vehicle driven by 2 power sources (a combustion engine and high
voltage battery). It is equipped with, and utilizes, a combination of a gasoline engine and electric motor,
or a diesel engine and electric motor. Usually, a combination of gasoline engine and electric motor is
used. In general, the term “Hybrid” means the combination of two different objects to create something
new. Therefore, the HEV can be defined as a vehicle that utilizes power from both the engine and the
motor to achieve higher fuel efficiency.
- 2 Power sources are used (Combustion engine + Electric motor)
- Increased fuel economy
- Reduced emission

Memo

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Chapter 1. Introduction of TF HEV

1.3 Types of HEV (by structure)
Parallel type
HEV
System

FMED
(Flywheel Mounted
Electric Device)

TMED
(Transmission Mounted
Electric Device)

Power split

Not available
: Mild (Soft) type

Available
: Full (Hard) type

Available
: Full (Hard) type

EV mode

Wheel

Battery

Wheel
Engine
Wheel

Battery

Schematic

Engine

TM

Motor

HSG

Motor

TM

Clutch
Wheel
Battery
Wheel

Wheel
S1

Wheel
Engine

Motor
Clutch1

TM

FD

- Hyundai: Gets, Accent
- Kia: Rio
- Honda: Civic, Accord

- Hyundai: Sonata
- Kia: Optima
- PSA: 308, C4
- VW: Touareg,
- Audi: Q7
- Porsche: Cayenne

MG1

C1
Engine

Clutch 2
Wheel

Model

Wheel

FD
Battery

Clutch

FD

R1
CL1

MG2

S2
C2

CL2
BK1

FD

R2
Wheel

- Toyota: Prius, Camry,
RX400h, Highlander
- Ford: Escape, Mariner
- GM: Tahoe, Yukon
- Benz: ML450

Let’s learn about the common hybrid types. They are the parallel-type and the power-split type.
Parallel-Type
In the case of the parallel-type, the engine and drive shaft are mechanically connected so the system
requires a transmission. It has the benefit of accommodating a small capacity drive motor. The paralleltype is categorized as the Flywheel Mounted Electric Device (FMED) type and the Transmission
Mounted Electric Device (TMED) type depending on the mounting position of the motor. In the case of
the FMED type, the motor is mechanically connected to the engine and the system executes engine
start, engine power assist and regenerative braking functions. This type, however, makes it structurally
impossible for electric drive mode. It is also known as a mild or soft type hybrid system. Vehicles using
the FMED type include Honda Civic/Accord, Hyundai Accent/HD Elantra, and KIA Rio/Forte. In contrast,
the motor in the TMED type is directly connected to the transmission and is separated from the engine.
There is a clutch between the engine and the motor. This separation allows electric drive mode. As the
TMED type allows electric drive mode, it has higher fuel efficiency than the FMED type. A system that

has electric drive mode capability is also known as a full or hard type hybrid system. It uses existing
transmission and investment cost is therefore lower. However, it does require precision control. Also,
because the motor and engine are separated, the TMED type requires an additional starter to start the
engine while the vehicle is in motion. The TMED type is utilized in Kia Optima, Peugeot, Volks Wagon,
Audi, and Porsche hybrid.
Power Split Type
The power split type, which is also known as the Toyota Hybrid System (THS) (because it was first
developed by Toyota), connects the engine and 2 motors via planetary gear sets. It uses planetary
gears and motor control instead of transmission to control the vehicle speed. As the power split type
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Chapter 1. Introduction of TF HEV

allows electric drive mode, it is a full type hybrid. Although it has the drawback of requiring a highcapacity motor, it boasts efficiency and outstanding driving stability. Toyota, Ford, GM, BMW, and
Mercedes utilize the power split type in their hybrid vehicles.

1.4 Comparison of Mild Type and Full Type

Start

Coasting

Accelerate/Uphi
ll

Decelerate

Stop

Engine+Motor

Engine

Engine+Motor

Inertia Energy
Battery Charge

Engine
Auto Stop

[Mild(Soft) type]

Start

Coasting
(low-speed)
Motor

Coasting
(high speed)

Accelerate/
Uphill

Motor+Engine

Decelerate

Stop

Inertia Energy
Battery
Charge

Engine
Auto Stop

[Full(Hard) type]

The differentiating criteria of the mild type and the full type are whether the hybrid vehicle can drive with
only electric motor power and without the need for the engine.
In the case of the mild type, which does not support electric drive mode, both the motor and the engine
power are used during startup. However the vehicle runs by the engine without motor assist when less
loaded such as coasting driving. In cases of acceleration or highly engine loaded such as in uphill
driving, the motor supports the engine power. When the vehicles brakes, the generated heat energy is
transformed into electricity by the motor and stored in the battery. This process is also known as
regenerative braking. When the vehicle comes to a stop, the engine is also stopped to conserve fuel.
This is known as idle stop.
In the case of the full type, the vehicle is driven only by the electric motor during startup and low speed.

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Chapter 1. Introduction of TF HEV

1.5 Plug-In Hybrid Electric Vehicle (PHEV) System
Cat.

Stru
ctur
e

Conventional Vehicle

Hybrid Electric Vehicle

Plug-In Hybrid

Battery

Battery
Battery

Engine

Engine
Gas

Battery
Electric
Motor

Electric
Motor
Engine

Electric Vehicle

Gas

Gas

Electric
Motor

Pow
er
Sou
rce

Engine

Engine+Motor

Engine+Motor

Motor

Fuel

Gasoline

Gasoline

Electricity, Gasoline

Electricity

Hybrid vehicles are more widely used for their environmentally friendliness. However, the engine on
hybrid vehicles are not being used efficiently and a large amount of electric energy is lost during the
conversion and storing process.
The PHEV, which many automobile manufacturers are recently turning to, eliminates energy loss during
the energy conversion process and utilizes existing efficient engines. The Plug-in Hybrid Vehicle is a
hybrid vehicle with an added electric plug to charge the battery using general household electricity. This
represents a midpoint before complete migration to electric vehicles. Compared to general hybrid
vehicles, the Plug-in Hybrid has a longer battery and motor driving distance. It is therefore highly
efficient in terms of fuel consumption and emission gas. This vehicle can travel approximately 30 miles
on a single charge, and it uses regular diesel or gasoline fuel for farther distances.
Many major automobile makers forecast that the global hybrid vehicle market will grow to over 40 million
vehicles annually by 2020, and most believe that the majority of these hybrids will be Plug-in Hybrid
Vehicles.

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Chapter 1. Introduction of TF HEV

2. Optima Hybrid System Overview
2.1 Hybrid System Components

Theta-II 2.4 HEV
- Atkinson Cycle

HPCU (Hybrid Power Control Unit)
- Integrated package
: Motor/HSG Inverter (MCU), LDC, HCU
High voltage battery
- Lithium-polymer

Electric motor
: 30kW

Hybrid cluster

Electric A/C compressor

6 Speed AT
- Without torque converter
- Engine clutch + Electric motor

AHB (Active Hydraulic Booster)
- Increased regenerative energy
AAF (Active Air Flap)

Electric oil pump
HSG
(Hybrid Starter Generator)
- 8.5kW

The main components of the Optima hybrid system are,
· Theta-II 2.4 HEV
· 6 Speed Automatic Transaxle
· Electric motor & HSG (Hybrid Starter Generator)
· High voltage battery
· MCU (Motor Control Unit, or Inverter)
· LDC (Low DC-DC Converter)
· HCU (HEV system Control Unit)

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Chapter 1. Introduction of TF HEV

2.2 Hybrid Engine (Theta-II 2.4 MPI with Atkinson Cycle)

Lower valve spring force

Thermostat

Atkinson Cycle

Gas
oline
Hybri
d
Increase compression ratio

Piston ring coating
Chrome

CrNPVD

Theta-Ⅱ Atkinson cycle hybrid engine basically uses Theta II 2.4L MPI engine, but it is modified to
maximize the engine efficiency and not the engine power for fuel economy. In addition to the application
of the Atkinson Cycle to reduce engine pumping loss, more items are utilized as below.
Compression ratio is increased and piston shape is changed to reduce the combustion chamber
volume. The thermostat opening temperature is increased to 88°C (190.4°F) resulting in better
combustion. Also, a lighter valve spring and a piston ring coated with low-friction material are used.

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Chapter 1. Introduction of TF HEV

2.3 Hybrid Automatic Transaxle (A6MF2H)

Case
Gear Train

Mechanical Oil
Pump

Engine Clutch

TCU (PCU Type)

Torsion Damper

Valve Body
Electric Oil Pump

OPU

Instead of CVT which is widely used in other competitors, the hybrid vehicle’s exclusive 6-speed
automatic transaxle is installed to transfer power from the engine or motor.
The torque converter in existing automatic transaxle is removed. Instead, the motor, engine clutch and
torsional damper are installed in its place.
The electric oil pump is mounted on the side of the automatic transaxle. It generates required hydraulic

pressure for transaxle and engine clutch during low speed driving or Electric Vehicle mode in which the
vehicle operates only on the motor with the engine stopped.

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Chapter 1. Introduction of TF HEV

2.4 Electric Motor & HSG (Hybrid Starter Generator)

Electric motor

HSG
(Hybrid Starter Generator)

AT assembly

Electric Motor
The drive motor installed in the Optima Hybrid has achieved the highest performance in its class with a
maximum power output of 30 kilo watt from the electric motor that produces a maximum torque of 205
Newton meter.
The hybrid electric motor is an important component that receives power from the battery and supports
the engine power during acceleration. It recharges the battery with the electric energy generated during
deceleration.
In Electric Vehicle mode, the electric motor provides traction power necessary to move the vehicle
without support from the engine. In hybrid mode, the electric motor supports engine power and stores
output energy during braking using the generator.
Hybrid Starter Generator (HSG)

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Chapter 1. Introduction of TF HEV

The Hybrid Starter Generator or HSG assembly allows the Optima Hybrid to switch between Electric
Vehicle and Hybrid modes. It cranks the engine for starting and can acts as a generator when
necessary if the hybrid battery state of charge is below a specified threshold.

2.5 High Voltage Battery & BMS
Cooling system
High voltage battery
Lithium-ion polymer battery
270V / 5.3Ah, 72Cells in series

BMS*
Voltage, Current, Temperature sensing
SOC* estimation, Power-cut, Cooling control,
Relay control, Cell balancing, Diagnosis

Maintain proper temperature
Equipped with BLDC* cooling pan
- Increase air flow & Reduce noise

Power Relay Ass’y(PRA)
Relay ON/OFF control
Battery current check

The high-voltage battery has four major components contained in the assembly.
The 270 volt battery assembly is developed using the lithium-ion polymer battery technology. To
enhance safety, the assembly uses a battery current check circuit which shuts off electric current in case

of over-charge.
A 12 volt blower air cooling system is used to maintain optimal battery temperature by passing cool air
through the battery case.
The Battery Management System module is contained inside the battery case and maintains the optimal
performance of the high voltage battery. The BMS measures the current, voltage and temperature of the
battery and estimates the high voltage battery stage of charge. It controls the battery cooling fan to
maintain optimal battery operation temperature and performs the cell balancing control which minimizes
voltage deviation of each cell during battery charging and discharging. In addition, if a system fault
occurs, the BMS turns off the high-voltage relay to protect hybrid system from the high voltage.
In addition, active protection devices such as the power relay assembly and fuse are used to improve
reliability and durability.

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Chapter 1. Introduction of TF HEV

2.6 Motor Control Unit (MCU) or Inverter

MCU = Inverter + Converter

Inverting

AC
Motor

DC
MCU

High voltage battery

Converting
HSG

The MCU has an inverter feature that transforms direct current to alternating current, and at the same
time a converter feature that does the reverse.
The MCU’s inverter circuits generates alternating current to operate the electric motor from the direct
current of the high voltage battery. The MCU’s converter circuits transforms the alternating current of the
motor to Direct current to charge the high voltage battery.
- Inverter: Transforming the DC of High Voltage Battery to AC for Motor operation
- Converter: Converting the generated AC to DC for High Voltage Battery Charging

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Chapter 1. Introduction of TF HEV

Memo

2.7 Low voltage DC-DC converter (LDC)
Hybrid Electric Vehicle

Conventional Vehicle

Alternator

Batter
y

Electric load

High voltage battery
(270V)

Inverter
(MCU)

LDC

Aux.
Battery(12V)

Electric
load

In conventional vehicles, an alternator is used to supply 12-volt power to electric devices and charge the
battery while the engine is running. But in Hybrid Electric Vehicle, the LDC transforms the electric
power from the high-voltage battery to 12 V and supplies power to electric devices and the auxiliary
battery.
Because the LDC is used, there is no alternator on the HEV and not additional engine load.
- Converting 270 DC voltage to 12V DC voltage
- Charging the 12V auxiliary battery (Alternator is removed)

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Chapter 1. Introduction of TF HEV

Memo

2.8 Active Air Flap (AAF)

- Reduced air resistance according to the driving condition
- Better fuel economy

Input signals
Flap open

Chassis-CAN
Flap close

· Engine coolant temperature
· A/C pressure
· Outside temperature
· Vehicle speed
· Etc.. (LDC/Motor temp.)

Smart Actuator

An active air flap is mounted between the front bumper grille and the radiator. It is controlled according
to the driving conditions.
The flap is closed while driving to reduce air resistance. When the engine temperature increases to the
threshold, the flap is opened to reduce the engine room temperature.
The engine coolant temperature, A/C pressure, and the vehicle speed are transmitted via CAN
communication and the smart actuator opens and closes the flap.

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Chapter 1. Introduction of TF HEV

2.9 Hybrid Brake System
Pedal travel sensor
Hydraulic Braking
Amount

Master cylinder + Pedal simulator

Regenerative Braking
Amount (by Motor)
ESC
(HEV)

AHB
(Active Hydraulic Booster)
Hydraulic flow
Electronic flow

Total Braking Amount
(Cooperative Control)

The brake vacuum booster which uses the engine vacuum cannot be used in an electric-motor-driven
hybrid vehicle. Therefore, an active hydraulic booster is used. A pedal simulator and pedal travel sensor
are also added and provide a pedal feeling for those drivers who are used to the vacuum booster.
During braking, the hydraulic brake and regenerative brake by the electric motor are engaged
simultaneously.

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Chapter 1. Introduction of TF HEV

2.10 Electric A/C Compressor
Electric A/C
Compressor

FATC

HCU
②

⑤

③

④
①

No.

Description

1

A/C ON signal input

2

Operating permission & Max. power signal

3

Permission & Allowable power

4

Compressor RPM within allowable power

5

Compressor RPM & power consumption

An electric compressor is used to ensure continued operation of the A/C, even when the engine stops.
If the A/C switch is pressed, the FATC sends an operation authorization request to the HCU. The HCU
transmits the operation allowance signal with an allowable electric power amount to the FATC. The
FATC controls the electric compressor within the allowable electric power range.

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Chapter 1. Introduction of TF HEV

2.11 Technology for Fuel Economy
Normal Vehicle

Hybrid Electric Vehicle
Idle-stop
EV,
Assist

Regeneration
Braking

Stand by

Stand by

Fuel

Drive

Drive

Drive

Braking

LDC
Operating pt.

Idle stop

Reduced fuel loss

LDC

Reduced engine load

Downsizing
(Atkinson cycle)

Regenerative braking
Torque converter
removed

T
/
M

Engine

E
T
W

Fuel

Optimize engine
operation point
EV, Assist

Better engine
efficiency

Energy recycling

Improve driving
efficiency

Less air resistance

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Chapter 1. Introduction of TF HEV

The main goal of developing the hybrid vehicle is to reduce emission gas and increase fuel efficiency. In
particular, technology that recycles or reduces energy loss during combustion is utilized to improve fuel
efficiency.
Approximately 80% of energy is known to be lost in a gasoline engine. Even when assuming complete
combustion, most of the energy generated from the fuel in the combustion chamber undergoes
numerous loss-incurring processes, and only a portion of the energy is used to drive the vehicle. There
are various types of energy loss. Some of the major areas of loss include exhaust, cooling, engine
pumping, operation of various engine support components, drive resistance, and brake loss.
In the case of hybrid vehicles, various technologies that either reduce or recycle such energy losses and
their applications are listed as follows:
- Engine torque and RPM control activate the engine in fuel-efficient conditions
- Engine turn off when the vehicle comes to a stop (idle stop) to improve fuel efficiency
- Power loss reduction caused by removing the generator due to the LDC
- Atkinson Cycle application to reduce engine pumping loss
- Brake loss conversion to electric energy to charge the high voltage battery
- Torque converter elimination in automatic transmission to reduce power loss
- Vehicle’s air resistance reduction to improve fuel efficiency

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Chapter 1. Introduction of TF HEV

3. Optima Hybrid Control Mode
3.1 HEV System Control Mode

Engine Cranking

Engine
HSG

Motor

AT

EV Driving

FD

Clutch

Engine
HSG

Engine Only Driving

HSG

AT

FD

Clutch

Battery

Battery

Engine

Motor

Motor

AT

Clutch

Battery

HEV Driving ; Power Assist by Motor

FD

Engine
HSG

Motor

AT

FD

Clutch

Battery

Engine Cranking
The Hybrid Starter Generator (HSG) is activated with electricity from the high voltage battery. The drive
belt linked to the HSG is driven and the engine starts. In the event of HSG failure or the drive belt
broken, the engine is started by the electric motor.
EV Driving
If the state of charge of the high voltage battery is normal, only the electric motor power is used when
the vehicle starts to move or during low-speed driving. As the engine is OFF, the automatic transmission
hydraulic pressure is generated by the electric oil pump. When the A/C is activated, the electricity is
supplied to the electric A/C compressor from the high voltage battery.
Engine Only Driving
This mode uses only engine power while driving. The engine clutch is engaged to transfer engine power
to the transmission.
HEV Driving: Power Assist by Motor
In cases of sudden acceleration, the electric motor is activated to support the engine power and
increase torque.

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Chapter 1. Introduction of TF HEV

HEV Driving ; Charging by Engine

Engine

Motor

AT

FD

Clutch

HSG

Regenerative Braking

Engine
HSG

Motor

AT

FD

Clutch

Idle Charging (Vehicle Stop in Drive & SOC Low)

Motor

AT

Clutch

HSG

FD

Battery

Battery

Engine

AT

Battery

FD

Idle Stop

Engine
HSG

Motor
Clutch

Battery

HEV Driving: Charging by Engine
This control mode uses the motor as an alternator to charge the high voltage battery while driving with
engine power. This mode is engaged when the state of charge of the high voltage battery is low.
Regenerative Braking
This control mode converts the kinetic energy of the vehicle, which is dissipated when the vehicle
decelerates or comes to a stop, to electrical energy. This electrical energy is then used to charge the
high voltage battery. The electric motor is used as an generator and the braking effect increases as the

generation amount also increases. The AC generated by the electric motor passes through the MCU
and is converted to DC which is supplied to the high voltage battery.
Idle Charging
When the state of charge of the high voltage battery is low, the engine runs idle when the vehicle comes
to a stop to charge the battery. The HSG, connected to the drive belt, is used as the generator after
engine startup. The generated AC passes through the MCU and is converted to DC which is supplied to
the high voltage battery.
Idle Stop
If the state of charge of the high voltage battery is normal, the engine turns off when the vehicle comes
to a stop. As the vehicle is powered only by the electric motor when it starts to move, the engine is not
restarted.

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Chapter 1. Introduction of TF HEV

3.2 Hybrid System Configuration

ECM

TCM
PCM

* Dual CAN: Hybrid CAN and Chassis CAN

Many control devices are connected to the high-speed CAN in the Optima HEV. The devices send and
receive various kinds of system information. If there is too much load on the CAN, the communicating
data become unstable. The Dual High Speed CAN (Hybrid CAN + Chassis CAN) is used to eliminate
this problem. The Dual CAN is applied to vehicle-drive-related systems including the HCU, ECM, TCM,

MCU, and BMS.
Abbreviations
· HPCU: Hybrid Power Control Unit
· HCU: HEV Control Unit
· PCM: Power-train Control Unit
· ECM: Engine Control Unit
· TCM: Transmission Control Unit
· OPU: Oil pump Unit
· MCU: Motor Control Unit
· BMS: Battery Management System
· LDC: Low Voltage DC-DC Converter

· ESC: Electronic Stability Control
· FATC: Full Automatic Temperature Control
· MDPS: Motor Driven Power Steering
· ACU: Airbag Control Unit
· AHB: Active Hydraulic Booster
· AAF: Active Air Flap
· TPMS: Tire Pressure Monitoring System
· EWP: Electronic Water Pump
· VESS: Virtual Engine Sound System
· TMU: Telematics Unit

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