NFPA ELECTRIC VEHICLE SAFETY FOR EMERGENCY RESPONDERS

Module III:Vehicle Systems

and Safety Features

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NFPA ELECTRIC VEHICLE SAFETY FOR EMERGENCY RESPONDERSModule III: Vehicle Systems and SafetyFeatures

Describe the operation of P/HEV and EV systems. Terminal Objective

● 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.

Enabling Objectives

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Module III Objectives

Hybrid Electric (HEV)

All hybrids use batteries and electric motors to reduce demand on the internal combustion engine (ICE).

● Allows better fuel economy.

● 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.

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Toyota Prius

Honda Civic Hybrid

Plug-In Hybrid Electric(PHEV)

• Increases battery charge

• Increases range • Reduces dependence on the gasoline engine.

A hybrid vehicle that allows the battery to be charged via an external power source.

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2012 Toyota Prius

Electric Vehicle• Electric motors are the only means

of propulsion.

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• Vehicle must be charged by an external power source.

Nissan Leaf

Extended Range Electric Vehicle

• Electric motors provide the propulsion.

• When battery is low, gasoline generator provides the electricity for the motor.

• For emergency response, treat as a PHEV with…• a gasoline engine• high voltage battery• electric propulsion• possible external power.

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Chevrolet Volt

High Voltage Battery Recharging

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3 Methods

External Power (Plug In)

Regenerative Braking

Engine Power

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.

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Can damage HV system if towed with drive wheels on ground (fire hazard).

Video

Vehicle Types

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Video

Vehicle Types

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Response Breakdown

● Hybrids

● Plug-in Hybrids

● Extended Range EVs

High Voltage and Fuel

High Voltage Only

● Pure EVs

Vehicle types by hazards

HEV / PHEV / EVVEHICLE COMPONENTS

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Standard Components

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12 VDC battery can be located in various locations around vehicle.

Common Locations:· Trunk / Cargo compartment· Under hood

Internal Combustion Engine (Not in EVs)

12 Volt DC Battery

Less Common Locations:· Front wheel well· Under 2nd Row seats

High Voltage Batteries

Battery Types

Lithium Ion

Various Materials

NiMH

Nickel Metal Hydride

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High Voltage Batteries

Nickel Metal Hydride (NiMH)Battery

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● Most common battery in HEVs.

● Electrolyte is caustic alkaline

and may produce harmful fumes if exposed.

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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.

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High Voltage Batteries

Small Cells in Series

● High voltage batteries are made of many small, low-voltage cells.

● Small cells wired in series to multiply voltage.

● Ex: Four 1.5 VDC batteries in series equals

6 VDC.

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.

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Video

12 VDC and High Voltage Batteries

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Video

12 VDC and High Voltage Batteries

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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.

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Service disconnect will be addressed later in course.

Inverter/ Converter

● 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.

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Located under hood

Inverter/ Converter

● Capacitors inside unit can store energy for a period of time.

● If damaged, capable of rapid energy discharge that can cause severe injuries.

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Located under hood

Dangerous to penetrate cover with tools.

DC-DC Converter

● 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 (APM) for Chevrolet Volt

● Serves as second 12V power supply (in addition to 12V battery).

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

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● 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

Video

The 12V System and the HV Relay

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Video

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The 12V System and the HV Relay

Video

High Voltage Battery Relay

Animation

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Video

High Voltage Battery Relay

Animation

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EV/ HEV Cabling

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● Low Voltage: <30 Volts Often Red or Black

● Intermediate: 30-60 Volts Usually Yellow or Blue

● High Voltage: >60 VoltsOrange

Color coded to SAE voltage levels

Medium/High Voltage Cabling

Medium and high voltage should both be considered highly dangerous.

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For safety, treat yellow and blue

cables the same as high voltage

orange.

Location

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High Voltage Cabling

● Between the HV battery, HV

components, and the electric motor.

● Typically routed along the underside of the vehicle and under hood.

Construction/Fault Protection

If a cable is compromised or damaged, the system is designed to detect the damage and shut down.

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For safety, ALL high voltage cable should be considered energized during response operations.

High Voltage Cabling

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

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Safety Systems

● Crash Impact

● Airbag Deployment

● Cabling Damage

● Short Circuits

P/HEVs and EVs have safety systems designed to automatically shut down the high voltage systems in the event of:

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However, always treat HV systems as energized for maximum safety.

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 I120 VAC

8-16 hours

Level II240 VAC3-8 hours

DC Quick Charge480 VDC

20-30 min.

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Level 1 Charging Station

Level I120 VAC

8-16 hours

● Utilizes 120VAC power.

● Uses standard household plug.

● Slowest rate of the three levels.

● Can accompany vehicle to charge it anywhere.

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Level II Charging Station

Level II240 VAC3-8 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.

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● Conducts current.

● Relays charge status.

● Shuts down charging when battery “full.”

● Prevents vehicle from moving when plugged in.

DC Quick Charge Station

DC Quick Charge480 VDC

20-30 min.

● Currently provides 480VDC directly to the battery.

● 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

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Charging Stations

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.

P/HEV, EV Components

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Activity 3.1

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High Voltage Battery

The electrical storage system that provides power for vehicle systems.

Component

Function

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High Voltage Cabling

Wiring used to carry electric current from the high voltage battery to the electrical motor.

Component

Function

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Inverter / Converter

Devices which convert DC from the high voltage battery to AC to drive the motor.

Component

Function

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Charging Ports

Electrical connections on a vehicle for connecting the high voltage battery to a charging source.

Component

Function

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Manual Service Disconnect

Cuts off the battery from the high voltage system.

Component

Function

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Refer to Manufacturer ERG before use!

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J1772 Connector

Multi-pin communication link between charger and vehicle.

Component

Function

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• 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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Module Summary