8. Connection to generator plants
•direct connection to generation plants as is common among electric
trains, trolley buses, and trolley trucks
•Online Electric Vehicle collects power from electric power strips
buried under the road surface through electromagnetic induction
Onboard generators and hybrid EVs
•renewable sources such as solar power: solar vehicle
It is also possible to have hybrid EVs that derive electricity from
multiple sources. Such as:
•on-board rechargeable electricity storage system (RESS) and a direct
continuous connection to land-based generation plants for purposes of
on-highway recharging with unrestricted highway range
•on-board rechargeable electricity storage system and a fueled
propulsion power source (internal combustion engine): plug-in hybrid
9. Batteries
Today’s electric cars mostly use Lithium-ion batteries,
exactly the same technology you’ll find in your laptop.
They’re relatively light, fairly good at storing useful amounts
of power for their weight, last several years and hundreds of
charges, and perform reasonably well at varied range of
temperatures.
Electric Motors
The power of a vehicle electric motor, as in other vehicles, is
measured in kilowatts(kW).Usually, direct current (DC) electricity
is fed into a DC/AC inverter where it is converted to alternating
current (AC) electricity and this AC electricity is connected to a 3-
phase AC motor. For electric trains, forklift trucks, and some
electric cars, DC motors are often used. In some cases, universal
motors are used, and then AC or DC may be employed.
11. The propulsion system has two machines, one machine is
operating mostly as a motor while the other machine is
operating mostly as a generator. Both machines of the
Voltec electric drive system are permanent magnet AC
synchronous machine types with the magnets buried inside
the rotor.
Voltec propulsion system consists of two machines. Both the
machines are buried (interior) permanent magnet type. The
larger of the two machines which is used mostly as an
electric motor (to provide electrical propulsion or) is of bar
wound type.
14. For a conventional vehicle, if you want more power, you
need to burn more fuel more quickly- a basic law of physics
called the law of conservation of energy tells us that-
burning gas faster makes more power and ultimately
delivers more speed.
The motor in an EV is very different; up to a point, it has no
preference whether it spins fast or slow-its pretty good at
delivering the same torque at any moderate speed.
15. A rough indication of how torque varies with speed for
electric motors and gasoline engines of comparable power.
Electric motors produce maximum torque right from the off,
whereas gasoline engines need to pick up quite a bit of
speed to deliver maximum torque.
16. Electric vehicles are considerably more efficient than
gasoline vehicles because electric motors are inherently
more efficient(about 80%) than internal combustion
engines(mere 30%), which wastes a high proportion of the
fuel they burn as useless heat.
Hybrid vehicles achieve their higher efficiency and fuel
economy largely by switching from gasoline power to
electricity whenever it’s favorable, such as sitting still in
heavy traffic.
17. It’s not just the engine that makes an Electric Vehicle more
efficient. With regenerative brakes, you are not throwing
energy away every time you stop and stop; the car’s electric
motor becomes a generator so that when the brakes are
engaged, the car slows down as your kinetic energy turns to
electricity that recharges the battery.
18. Even in performance, electric vehicles sometimes outclass
gasoline vehicles. As we’ve already seen electric motors can
produce high torque even at low speeds, which means they
can accelerate faster as compared to electric vehicles.
Maintenance is also less of a chore, because Electric vehicles
are generally simpler than gasoline vehicles.
An Electric motor is an inherently simpler bit of kit than a
gasoline engine with far fewer moving parts to wear out.