Investigation - Definition of Electric Vehicles
An electric vehicle (EV) uses an electric traction motor for propulsion. A ‘pure’ EV does not have an engine.
The Nissan Leaf is an example of a pure EV. It uses a front-mounted electric traction motor to drive the road wheels, powered by a high voltage (HV) battery pack located under the floor and seats. The vehicle produces zero tailpipe emissions at its point of operation.
Use the Nissan Leaf Information Sheet to find out more about the Nissan Leaf, and then answer the questions that follow.
Nissan Leaf Information Sheet
Performance and Range
Performance: The Nissan Leaf can reach a top speed of
over 93 mph (150 km/h). It can accelerate from 0 to 60 mph
(0 to 97 km/h) in approximately 9.9 seconds.
Range: The range obtained from a single charge will depend
on vehicle load, traffic conditions, driving style, weather, and
accessory use. The average range figure from Nissan is 73 miles (118 km).
Electric Traction Motor
The Nissan Leaf uses a synchronous AC electric motor that provides 109 horsepower (80 kW) and a torque output of 187 lb-ft.
Motor operation is controlled by an electronic control unit located in the center of the engine compartment.
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Battery Pack
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The lithium-ion battery pack has a total capacity of 24 kWh and can deliver power up to 120 hp (90 kW). The pack contains 192 air-cooled cells, packaged in 48 modules (4 per module). Each cell has an energy density of 140 Wh/kg.
The life of the battery pack is determined by environmental conditions and how often it is fast-charged. It is expected that the battery pack will retain 70 % to 80 % of its capacity after ten years.
A typical warranty offered by Nissan is eight years or 100,000 miles (160,000 km), although this will depend on the country.
Plug-in Charging
.jpg "Charging ports")
The charging ports are hidden under a flap at the front of the vehicle.
It has a 9 horsepower (6.6 kW) on-board charger, which means that the battery pack can be fully recharged in about 4 hours at home.
The battery pack can be charged to 80 % of its capacity in 30 minutes using a 50 kW fast charger at a charging station.
Nissan Leaf
a) What is the average range figure from Nissan, and what factors will affect the actual range obtained?
b) Explain the construction of the Nissan Leaf battery pack.
c) What is the life expectancy of the battery pack?
a) The average range figure from Nissan is 73 miles (118 km). The actual range obtained will depend on vehicle load, traffic conditions, driving style, weather, and accessory use.
b) The lithium-ion battery pack has a total capacity of 24 kWh and can deliver power up to 120 hp (90 kW). The pack contains 192 air-cooled cells, packaged in 48 modules (4 per module). Each cell has an energy density of 140 Wh/kg.
c) Battery pack life is determined by environmental conditions and how often it is fast-charged. It is expected that the battery pack will retain approximately 75 % of its capacity after ten years.
Definition of Electric Vehicles
In this presentation you will see:
the basic construction of an electric vehicle
advantages and disadvantages of using electric vehicles
Introduction
Electric vehicles first came into existence in the 1830s, but then faded out of use.
Recent years have seen a renewed interest in developing this technology.
This is mostly due to increased concerns about the environment impact of internal combustion engines.
What is an Electric Vehicle?
An electric vehicle (EV) uses an electric traction motor for propulsion.
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A ‘pure’ EV does not have an engine.
The electric motor is powered by a high voltage (HV) battery pack.
Construction
The diagram shows the components that make up an electric vehicle.
The electric motor is used to drive the road wheels.
HV Battery Pack
The HV battery pack is recharged from the domestic electricity supply via the plug-in connection.
It can also be charged during regenerative braking.
Electricity Source
The power for electric vehicles can come from three sources.
◼Direct power from an external power station Vewer
◼Power from stored energy that originally came from an external power station
◼Power from an on-board electrical generator
The Advantages of Electric Vehicles
Electric vehicles have the following advantages:
◼Zero tailpipe emissions
◼Fewer components and, therefore, simple maintenance (no engine or gearbox) lapi
◼They can be charged conveniently at home, no trip to the gas station is required
◼Their speed and power are comparable to vehicles with a conventional engine, but with higher fuel efficiency
The Disadvantages of Electric Vehicles
Electric vehicles have the following disadvantages:
◼Limited range of travel, typically 100 miles
◼A network of plug-in charging sites is required
◼A long time is required to charge the battery, several hours for a full charge
◼The battery pack has limited life, it is expensive to replace, and there are safety issues associated with high voltages
Electric Vehicle Example
Nissan Leaf Production started in 2010 and uses a 109 hp (80 kW) AC motor.
The battery pack is a 24 kWh lithium-ion battery consisting of 48 modules, each containing four cells, giving a total of 192 cells.
t has a regenerative braking system to recycle energy during coasting and braking.
The 2013 Nissan Leaf
Nissan Leaf (100 % electric)
Power109 hp (80 kW)
0-60 mph9.9 seconds
Energy consumption34 kWh/100 miles