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Battery Electric Vehicles. 2011 Nissan Leaf. The images and text of this presentation are based on a 2011 Nissan Leaf All modern battery electric vehicles used similar system components but there will be differences in appearance and location of those components. Current vehicles in production.
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2011 Nissan Leaf • The images and text of this presentation are based on a 2011 Nissan Leaf • All modern battery electric vehicles used similar system components but there will be differences in appearance and location of those components
Current vehicles in production • Nissan Leaf • Tesla S • Chevrolet Spark EV • Toyota RAV-4 EV • Ford Focus EV • Honda Fit EV • Smart EV • Fiat 500e
Nissan Leaf - General information • 80 kilowatt electric motor /107 horsepower 280Nm/206 lbs-ft torque • Max motor speed 10,390 RPM • Operating range - 60 to 100 miles [depending on operating conditions, terrain and climate control settings] • 24 KWh Li-Ion battery pack • 3.3 Kilowatt onboard charger • Max vehicle speed = 90 mph
Charging port • The charging receptacle is located on the out side of the vehicle usually near the front of the vehicle Receptacle cover release lever
Charging Sockets • Two charging sockets: • J1772 [AC] is used for home charging at 110 or 220 volts AC • Quick charge port[DC] -sometimes referred to as CHAdeMO connects to commercial high voltage DC charging stations Quick charge [DC] J1772 [AC] Image by Richard Kelly- via Wikimedia Commons
J1772 charging receptacle • Level 1 & 2 charging is done through a standardized 5 pin receptacle Power Proximity [Safety] Communications Ground
Level 1 and Level 2 charging • Level 1 charging is done at 110 -120 volts • A level 1 charging cable can be plugged into any 110 volt 3 pin electrical socket • Charging a Leaf at 110 volts will take 21 hours if the battery is at 25% SOC • Level 2 charging is done at 220-240 volts • A level 2 charging station is hardwired and requires installation by licensed electrician • Charging at 220 volts reduces the Leaf’s charging time to 7 hours
Level 1 charging cable • The Level 1 charging cord has a three prong plug that can connect to any 110-120 volt outlet
Level 2 cable The level 2 cable fits the same socket as the level 1 but uses 220 volt AC current
Level 2 charging 220 Volt Level 2 charging station • In both Level 1 and Level 2 charging the onboard charger converts AC current into DC current and steps up the voltage to the level needed to efficiently charge the batteries Inverter Onboard charger 192 volts DC HV Battery 220 volts AC
Charging indicator lights • Most BEVs have an external indicator light that alerts the driver that the batteries have or have not been fully charged • The batteries are fully charged when all 3 LEDs are illuminated Battery charge Indicator lamps
Proximity pin • The proximity pin on the j1772 socket tells the EV control module that the charging connector is plugged in • This disables the park motor so that the vehicle cannot be moved while connected to the charger • The data terminal allows serial communication between the charger and the vehicles control module Proximity Data
Fast DC charging • The Nissan Leaf and Mitsubishi i-MiEV have a CHAdeMO connector for fast DC charging • High voltage DC charging can be accomplished in 30 minutes
J1772 fast charging plug • Chrysler-Fiat, Ford, GM, Audi, BMW, Daimler, Porsche and Volkswagen have chosen to use and updated j1772 plug for fast DC charging • The plug hast the 5 pins for the level 1 & 2 AC charging socket plus two additional pins for high voltage [up to 500 volts] DC
Fast charging and battery life • Most manufactures recommend that fast DC charging should only be used in situations where a Level 1 or Level 2 charge is not an option • Fast charging reduces the useable life expectancy of the battery • Since electric cars have only been available for sale only few years the rate of battery deterioration has not been quantified • If a brand new battery has a range of 100 miles [at 80% SOC] then when the battery at 80% SOC can drive the vehicle only 50 miles the battery has reached the end of its useable life
Range indicator • The right hand display shows how many more miles the vehicle can be driven Battery temperature display
BEV electric drive system components • HV battery array • Electric motor [Traction motor] • Reduction gear unit + differential • Inverter • DC-DC converter • Onboard charger
Driveline components 2011-2012 • On the 2011-2012 Leaf the inverter is bolted to brackets on the unit body and the DC-DC converter is bolted to the firewall DC-DC converter Inverter Charging connector sockets Gear reduction & differential Traction Motor
HV Battery assembly • 48 Li-Ion battery modules are located under the floor panel • The 392 volt battery module has no cooling system Inverter DC-DC converter Traction Motor Image courtesy of Nissan USA
HV Battery array The 24 KWh Battery array consists of 48 modules that are enclosed in a steel clamshell case HV battery control module HV connection to inverter Service plug socket 392 Volts DC at 80% SOC Rubber gasket
Battery module Each module contains 4 cell pouches Each cell develops about 4.0 volts at 80% SOC Two pairs of two cells connected in parallel are combined to develop 8 volts at the module terminals
Battery temperature • There are four temperature sensors mounted inside the battery case • The Li-Ion battery temperature is displayed on the left side of the instrument cluster • If the battery temperature exceeds the critical limit the power output of the traction motor will be reduced and the heater or A/C functions will be minimal
HV Battery removal • The HV battery weighs about 800 lbs • A special hydraulic lift table and battery holding fixture is required to service the battery
Electric Motor Mounting bracket for electric A/C compressor The Leaf has an 80 Kw [107 HP] electric motor Most manufactures use a permanent magnet type motor Only Tesla and Toyota [RAV-4 EV] use inductive motors
Stator leads and resolver The resolver in this Leaf motor uses a 4 lobed eccentric Removing the rear cover reveals the stator lead attachments and the resolver
Gear reduction Unit Parking pawl motor The gear reduction unit typically has a 8 to 1 speed reduction ratio Breather tube The reduction unit contains a differential gearset that divides torque equally to the left and right drive wheels An electric parking pawl motor locks the final drive when the shifter is returned to the park position
Gear reduction unit Input gear Output [Final drive] gear Idler gear Unlike an internal combustion engine an electric motor can easilyrun backwards When gear selector is placed in ‘R’ the traction motor reverses it’s direction of rotation This eliminates the need for a reverse gear
Park motor Park is activated by an electric motor attached to the gear reduction unit case
Parking pawl Ratcheting Spring • The parking pawl locks the idler gear so that it cannot turn • The pawl is pushed by a spring when the park motor is engaged • If the vehicle is moving the spring on the actuating rod will ratchet • A loud grinding noise will be heard but no serious damage to the transmission [or gear reduction unit] will occur Parking pawl Linkage rod connects to park motor Parking gear Intermediate [Idler] gear
Motor and reduction unit Earth brush cover Reduction unit fluid drain plug Radiators
Engine mounts and drive axles The traction motor and gear reduction unit sit on rubber engine mounts in the same manner as an ICE motor and transmission Inboard CV joint Right side engine mount
Ground Brush • The pulsating magnetic fields in the traction motor can induce small electrical currents in the motor shaft • This electrical current will try to find ground through the gears and ball bearings supporting them • The ground brush protects the gears and bearings by providing a safe path to ground
Ground brush holder • There is no brush replacement interval • The brushes should last for the life of the vehicle
Inverter • The inverter is located above the electric motor so that coolant can flow vertically from the motor to the coolant reservoir on top • This allows any air bubbles in the cooling system to rise to the top of the reservoir
Inverter -B +B • The inverter used IGBTs to control the flow of current through each of the three stator coils V U Stator W
Inverter • The DC-DC converter is not integrated into the inverter as it is on most hybrids • The inverter’s sole function is to provide 3 phase AC current for the traction motor
3 Phase HV cables • 6mm bolts connect the 3 phase HV cables to the bus bars inside the inverter
3 Phase HV cables The other end of the 3 phase cable is bolted to the top of the traction motor housing The stator leads are connected to the 3 cable end terminals
DC-DC converter • The DC-DC converter keeps the 12 volt battery fully charged and provides all the electrical current power for the lights, instruments and accessories 12 volt battery + terminal The DC-DC converter is located underneath the inverter Coolant tube The DC-DC converter takes high voltage DC current from the HV battery array and changes it to 14 volts DC 392 volt DC input terminals
12 Volt battery The Leaf uses a conventional flooded cell lead acid battery to provide power for the computer system, lights and power accessories when the system is turned off Removable cell covers
12 Volt battery Hall effect current sensor The battery cables connect the battery to the DC-DC converter The negative battery cable is also connected to chassis ground Both cable clamps have current monitoring sensors The positive clamp also has an IR temperature sensor that monitors battery temp
Onboard battery charging unit • When the vehicle is connected to a 120 AC volt power source the onboard charger steps up the voltage to 192 volts and rectifies it into DC current • When the vehicle is connected to 240 Volts AC the onboard charger steps down and rectifies the voltage to 192 VDC
Onboard charging unit The charging unit is water cooled Electrical noise filter unit Coolant tube connections serviced from underneath the vehicle Maximum charging rate is 3.3 Kilowatts
Onboard charger • The onboard charger has HV connections to the HV battery array and charging plug Electrical noise filter unit
Onboard charger coolant lines • Coolant lines connect the onboard charger to the radiator HV Cable to charger plug receptacle Coolant tubes Note: HV battery has been removed
2013 Leaf drive train Inverter For MY 2013 the charger has been moved to the front and sandwiched between the inverter and motor housing All 4 major components are now bolted together Onboard charger Traction motor Reduction gears and differential Image courtesy of Nissan North America