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NFPA ELECTRIC VEHICLE SAFETY FOR EMERGENCY RESPONDERS
Module III:
Vehicle Systems
and
Safety Features
3-1
NFPA ELECTRIC VEHICLE SAFETY FOR EMERGENCY RESPONDERS
Module III: Vehicle Systems and SafetyFeatures
Module III Objectives
Terminal Objective
Describe the operation of P/HEV and EV systems.
Enabling Objectives
●
●
●
●
Define terms related to P/HEV and EV systems.
Compare and contrast P/HEV’s and EV’s.
List major components of P/HEV systems.
List major components of EV systems.
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Hybrid Electric (HEV)
All hybrids use batteries and
electric motors to reduce demand
on the internal combustion
engine (ICE).
● Allows better fuel economy.
Toyota Prius
● ICE can shut down when not
needed.
● Some Hybrids can drive short
distances on electric power only
(silent movement hazard).
● For response purposes, treat
all hybrids the same.
Honda Civic Hybrid
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Plug-In Hybrid
Electric
(PHEV)
A hybrid vehicle
that allows the
battery to be
charged via an
external power
source.
• Increases battery charge
• Increases range
• Reduces dependence
on the gasoline engine.
2012 Toyota Prius
3-4
Electric Vehicle
•
•
Electric motors are the only means
of propulsion.
Vehicle must be charged by an external
power source.
Nissan Leaf
3-5
Extended
Range
Electric
Vehicle
•
Electric motors provide the propulsion.
•
When battery is low, gasoline generator
provides the electricity for the motor.
•
Chevrolet Volt
For emergency
response, treat as a
PHEV with…
•
•
•
•
a gasoline engine
high voltage battery
electric propulsion
possible external power.
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High Voltage Battery Recharging
3 Methods
Engine Power
Regenerative
Braking
External Power
(Plug In)
3-7
Term: Regenerative Braking
●
During braking, wheels
turn the electric motor,
making it act as a
generator and produce
electricity.
●
Electricity routed to
HV battery to increase
charge.
Can damage HV system if towed with
drive wheels on ground (fire hazard).
3-8
Video
Vehicle Types
3-9
Video
Vehicle Types
3-10
Response Breakdown
Vehicle types by hazards
High Voltage
and Fuel
●
Hybrids
●
Plug-in Hybrids
●
Extended Range EVs
High Voltage
Only
●
Pure EVs
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HEV / PHEV / EV
VEHICLE COMPONENTS
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Standard Components
Internal Combustion
Engine (Not in EVs)
12 Volt DC Battery
12 VDC battery can be located in various
locations around vehicle.
Common Locations:
· Trunk / Cargo compartment
· Under hood
Less Common Locations:
· Front wheel well
· Under 2nd Row seats
3-13
High Voltage Batteries
Battery Types
NiMH
Lithium
Ion
Nickel Metal
Hydride
Various
Materials
3-14
High Voltage Batteries
Nickel Metal Hydride (NiMH)
Battery
● Most common
battery in HEVs.
● Electrolyte is
caustic alkaline
and may
produce harmful
fumes if
exposed.
3-15
High Voltage Batteries
Lithium Ion (Li-Ion) Battery
● Most common in
PHEVs and EVs.
● Different from Li-Ion
batteries in home
electronics.
● Electrolyte may
produce harmful,
flammable fumes if
exposed.
3-16
High Voltage Batteries
Small Cells in Series
● High voltage
batteries are made
of many small, lowvoltage cells.
● Small cells wired in
series to multiply
voltage.
● Ex: Four 1.5 VDC
batteries in
series equals
6 VDC.
3-17
High Voltage Batteries
Location of Batteries in HEVs, PHEVs
Generally
located in rear
of vehicle.
Under 2nd row
seating in most
SUVs and trucks,
in trunk/ cargo area
in most sedans.
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High Voltage Batteries
Location of Batteries in EVs
● EV Batteries are often larger and of
higher capacity than P/HEV batteries.
● Usually located under the floor of
the vehicle.
3-19
Video
12 VDC and High
Voltage Batteries
3-20
Video
12 VDC and High
Voltage Batteries
3-21
High Voltage Batteries
Service Disconnects
● Recommendations for
use and required
safety equipment vary
by manufacturer.
Consult appropriate
ERG before using
service disconnect.
● Located on the
HV battery.
● Physically disconnects
the HV battery from HV
systems.
Service disconnect will be
addressed later in course.
3-22
Inverter/
Converter
Located
under hood
● Found in vehicles using AC drive motors.
● Converts DC from HV Battery to AC to run motor.
● Converts AC from regenerative braking back to
DC to charge HV Battery.
3-23
Inverter/
Converter
Located
under hood
Dangerous to penetrate
cover with tools.
●
Capacitors inside unit can store energy
for a period of time.
●
If damaged, capable of rapid energy
discharge that can cause severe injuries.
3-24
DC-DC
Converter
● Serves as
second 12V
power supply
(in addition to
12V battery).
DC-DC Converter (APM)
for Chevrolet Volt
● Provides same functions as alternator in
conventional vehicles.
● Steps down high voltage DC from the HV
battery to 12 VDC to run low voltage systems.
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DC-DC Converter
● In some models the DC-DC converter is
housed in the inverter/converter module.
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High Voltage Battery Relay
● Located on HV Battery.
● Functions like a switch.
● Activated by 12v power
from the low voltage
system
● Removal of 12v
power causes the relay
to open, stopping the
flow of HV current
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Video
The 12V System
and the HV Relay
3-28
Video
The 12V System
and the HV Relay
3-29
Video
High Voltage
Battery Relay
Animation
3-30
Video
High Voltage
Battery Relay
Animation
3-31
EV/ HEV Cabling
Color coded to SAE
voltage levels
● Low Voltage: <30 Volts
Often Red or Black
● Intermediate: 30-60 Volts
Usually Yellow or Blue
● High Voltage: >60 Volts
Orange
3-32
Medium/High
Voltage Cabling
Medium and high
voltage should both
be considered highly
dangerous.
For safety, treat
yellow and blue
cables the same as
high voltage
orange.
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High Voltage Cabling
Location
● Between the HV
battery, HV
components, and
the electric motor.
● Typically routed
along the underside
of the vehicle and
under hood.
3-34
High Voltage Cabling
Construction/Fault Protection
If a cable is compromised or damaged, the
system is designed to detect the damage
and shut down.
For safety, ALL
high voltage
cable should
be considered
energized
during
response
operations.
3-35
Electric Motors
•
Provide propulsion in
EVs and some
P/HEVs.
•
Start and stop the
ICE when not needed.
•
Recharge HV battery
through regenerative
braking and ICE.
•
Sometimes called
Drive Motors or
Traction Motors
3-36
Safety Systems
P/HEVs and EVs have safety systems
designed to automatically shut down
the high voltage systems in the event
of:
● Crash Impact
● Airbag Deployment
● Cabling Damage
● Short Circuits
However, always treat HV systems
as energized for maximum safety.
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Charging Ports
•
Connects charging
cord to vehicle.
•
Charging
components reside
on the vehicle.
•
The charging unit
is an interface
between the power
supply and the
vehicle.
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Charging Stations
Level I
Level II
120 VAC
8-16 hours
240 VAC
3-8 hours
DC Quick
Charge
480 VDC
20-30 min.
3-39
Level 1 Charging Station
Level I
120 VAC
8-16 hours
● Utilizes 120VAC power.
● Uses standard household
plug.
● Slowest rate of the three
levels.
● Can accompany vehicle
to charge it anywhere.
3-40
Level II Charging Station
Level II
240 VAC
3-8 hours
● Utilizes 240VAC power.
● Can be a fixed
installation or portable
unit.
● Faster than Level I
systems. Typically 3-8
hours depending on
the size of the battery.
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J1772 Plug and Receptacle
● SAE standardized for Level
I and II charging.
● Multi-pin charging/
communication link between
charger and vehicle.
● Conducts current.
● Relays charge status.
● Shuts down charging
when battery “full.”
● Prevents vehicle from
moving when pluggedin.
3-42
DC Quick Charge Station
DC Quick
Charge
● Currently provides 480VDC
directly to the battery.
480 VDC
20-30 min.
● New standards being
developed, so this may
change.
● Fastest charging system.
● Due to wiring requirements,
availability, and expense, will
likely be in commercial sites
only.
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Charging
Stations
3-44
Charging
Stations
3-45
Activity 3.1
P/HEV, EV Components
You will be shown a series of slides, each
with a picture of a component of a P/HEV
or EV.
You will be given a few moments to
discuss and decide on the name of the
component and its function.
Be prepared to share your answer with
the class.
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?
3-47
Component
High Voltage Battery
Function
The electrical storage system that
provides power for vehicle systems.
3-48
?
3-49
Component
High Voltage Cabling
Function
Wiring used to carry electric current
from the high voltage battery to the
electrical motor.
3-50
?
3-51
Component
Inverter / Converter
Function
Devices which convert DC from the
high voltage battery to AC to drive
the motor.
3-52
?
3-53
Component
Charging Ports
Function
Electrical connections on a vehicle
for connecting the high voltage
battery to a charging source.
3-54
?
3-55
Component
Manual Service Disconnect
Function
Cuts off the battery from the high
voltage system.
Refer to Manufacturer ERG
before use!
3-56
?
3-57
Component
J1772 Connector
Function
Multi-pin communication link
between charger and vehicle.
3-58
Module Summary
3-
•
There are several different
types of P/HEVs and EVs.
•
Each one has specific
components related to its
electrical identify.
•
Familiarity with the types,
components and differences
will facilitate emergency
operations.
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