Electric vehicles (EVs), including battery electric vehicles (BEVs), hybrid electric vehicles (HEVs), plug-in HEVs (PHEVs), fuel-cell electric vehicles (FCEVs), are becoming more commonplace in the transportation sector in recent times. The present trend suggests that this mode of transport is likely to replace internal combustion engine (ICE) vehicles in the near future. Each of the main EV components has a number of technologies that are currently in use or can become prominent in the future.
1.1Introduction
EVs can cause significant impacts on the environment, power system, and other related sectors. In recent times, the EV has been gaining popularity, which has many reasons. The most significant one is their contribution toward reducing greenhouse gas (GHG) emissions. In 2009, the transportation sector emitted 25% of the GHGs, produced by energy-related sectors. EVs, with enough penetration in the transportation sector, are expected to reduce that figure, but this is not the only reason bringing this century-old and once-dead concept back to life; this time, it makes it comeback as a commercially viable and available product. As a vehicle, an EV is quiet, easy to operate, and does not need any fuel cost that is associated with conventional vehicles. As an urban transport mode, it is highly useful. It does not use any stored energy or cause any emission while idling, is capable of frequent start-stop driving, provides the total torque from the start-up, and does not require any trips to gas stations for filling fuels. It does not contribute either to any of the smog that makes city's atmosphere highly polluted. The instant torque in an EV makes its performance highly preferable for participating in motor sports. The quietness and low infrared signature gives it value for military use as well. The power sector has been going through a changing phase in which renewable sources are gaining momentum. The next generation power grid, called “smart grid,” is also being developed. EVs are being considered a major contributor to this new power system that comprises renewable generating facilities and advanced grid systems. All these have led to a renewed interest and development in this mode of transport.
The idea to employ electric motors to drive a vehicle surfaced after the innovation of the motor itself. From 1897 to 1900, EVs had become 28% of the total vehicles and were preferred over the ICE ones. But the ICE types gained momentum afterward, and with very low oil prices, they soon conquered the market, became much more mature and advanced, and EVs got lost into oblivion. A chance of resurrection appeared in the form of the EV1 concept from General Motors, which was launched in 1996, and quickly became very popular. Other leading carmakers, including Ford, Toyota, and Honda, brought out their own EVs as well. Toyota's highly successful Prius, the first commercial HEV, was launched in Japan in 1997, with 18,000 units sold in the first year of production. Today, almost none of those twentieth century EVs exist; an exception could be made for the Toyota Prius, still going strong in a better and evolved form. Now the market is dominated by Nissan Leaf, Chevrolet Volt, and Tesla Model S, whereas the Chinese market is in the grip of BYD Auto Co., Ltd (Xi'an National Hi-tech Industrial Development Zone, Xi'an, China).
EVs can be considered a combination of different subsystems. Each of these systems interacts with each other to make the EV work, and there are multiple technologies that can be employed to operate the subsystems. EVs can run solely on electric propulsion or they can have an ICE working alongside it. Having only batteries as an energy source constitutes the basic kind of EVs, but there are kinds that can employ other energy source modes. These can be called HEVs. The International Electro-technical Commission's Technical Committee 69 (Electric Road Vehicles) proposed that vehicles using two or more types of energy sources, storages, or converters can be called as an HEV as long as at least one of those provides electrical energy. This definition makes a lot of combinations possible for HEVs such as ICE and battery, battery and flywheel, battery and capacitor, and battery and fuel cell (FC). Therefore, the common population and specialists both started calling vehicles with an ICE and electric motor combination as HEVs, battery and cap...
