Today, electric cars are encountered on the roads more and more often, and for many people, green transport is no longer an experiment, but quite an "ordinary" car, which can be bought and used every day for personal or commercial purposes. However, few people know how electric cars work. So, let us talk about parts of an electric car and what the "iron horse" generally looks like.

What is the Electric Car: Issues of Terminology

Let's take a look at the terminology: electric cars are called EV (Electrical Vehicle), although this word is used for any electric transport - from boats to airplanes. EC (Electric Car) is a more precise abbreviation, but it did not stick for some reason. On the other hand, the existing one often requires additional clarification. According to the modern classification, pure electric vehicles are called BEV (Battery Electric Vehicle). This category includes only those cars that do not have other sources of energy, except for batteries. The EV category also includes hybrid vehicles (HEV), plug-in hybrid electric vehicles (PHEV), and fuel cell electric vehicles (FCEV).  

In general, a real electric car is not characterized by the presence of a charging cable, but the absence of an exhaust pipe.

Key Features of an Electric Car

Power and torque

An electric motor has much lower friction losses. It does not require a complex lubrication system and almost does not wear out. That is why many modern electric cars claim to have a power plant with a capacity of 500+ horsepower and can accelerate faster than fully fueled cars with internal combustion engines (ICE). For example, two Porsche Taycan Turbo S electric motors together develop 761 hp and accelerate the car up to 100 km/year in 2.8 seconds.

Drive range

Nevertheless, most electric cars do not need a "whirlwind" performance - a car for everyday use is much more important to have a reliable drive range, which is determined by the battery capacity. While the first series of electric cars barely drove 100-150 km, the average mileage of modern electric cars on a single charge is, on average, 400 km.  This makes electric cars (if one travels 50-70 km per day) really convenient.  There are already models which can drive 600-800 km, and advances in technology make it possible for the engineers to ensure a cruising range of 800-1000 km for an ordinary electric car (Mercedes has already released such a car - EQXX concept presented in January 2022). Such models can be compared to traditional ICE cars.

Battery charging speed

This parameter also depends on the battery capacity. The speed also relies on the ability of batteries to receive a powerful charge with a large current, and most importantly – the charging infrastructure that can produce the necessary current. Currently, electric cars need the whole night for full charging from the domestic network, but with the help of a powerful charging terminal, the electric car with a modern battery will replenish its reserves by 80% in just 35-45 minutes. 

What are the Types of Electric Cars?

Since engineers started talking about switching cars to electric traction, electric cars have traveled a long way in their evolution. Today one can roughly single out several generations of electric cars (we will not talk about the emergence of electric cars at the beginning of the 20th century, as this is the topic for a separate publication). 

So, the first generation includes passenger electric cars created from ordinary cars. In such cars, ICE was replaced with an electric motor with an inverter, and the batteries were installed instead of the fuel tank in the trunk, which is why the latter became much smaller. And still, first generation BEV did not have a large power reserve, since such cars could not use energy efficiently - after all, they were equipped with a traditional transmission and other attributes of fuel vehicles. The speed of movement was also low. The only advantage of such design was its relative cheapness. The first generation also comprises numerous prototypes of previous years or, for example, a custom-built RAV4 EV released in 1997.

The second generation includes cars only partially unified with ICE cars. Their design was specifically adapted to the use of an electric power plant. They no longer had a conventional transmission, but electrical components were placed in the same "empty" places that remained after the phase-out of ICE. This design improved the performance of an electric car, but did not yet make it equal to a gasoline or diesel car.  Typical examples include  Kia Soul EV 2014 or VW E-Golf 2015, where batteries are placed under the front seats and in the central tunnel, which were able to travel slightly more than 100 km without recharging. Among representatives of this generation, the Nissan Leaf turned out to be the most adapted to everyday use: this Japanese hatchback no longer had analogs with ICE, but a large number of its components, as before, remained unified with other models of this Japanese brand.

The transition to the third generation can be dated back to the legendary Tesla Model S liftback – the first mass-produced electric car with a flat battery under the floor area and a rear-mounted engine, where fuel cars usually have a fuel tank. Such layout is almost impossible in conventional cars with ICE due to the size of the power plant. In electric cars it provides for the following advantages: the electric components do not occupy space for passengers and luggage, and the heavy battery placed under the floor has a positive impact on the car's weight and steerability (due to the low-located center of gravity). But the main thing is that the battery itself can have a larger size and, accordingly, a larger capacity, which positively affects the power reserve.

Additionally, Tesla introduced a twin-engine system, where each electric motor rotates its own axis. In addition to all obvious advantages of 4WD, such design makes the electric motor more compact and lightweight, as well as increases the overall capacity of the power plant improving both dynamics and efficiency. Therefore, the power reserve on one battery is larger. It is far from being a paradox because powerful engines are also powerful generators that generate additional electricity during braking.  Jaguar i-Pace also has a similar design combining a battery in the floor with decent off-road performance.

Other manufacturers developed a multi-engine idea further. For example, the modern Audi e-tron S already has three engines – each rear wheel is driven by its own engine, and the third engine is used to implement traction on the front axle. At the same time, there are already cars that are equipped with four engines! These are, for example, Rvian R1T, Rimac C_Two, etc.

The fourth generation of BEV incorporates the models (Porsche Taycan, new Hyundai electric cars and KIA E-GMP platform) that use highly efficient 800-volt battery charger systems instead of 380-450-volt ones. So far, they are unlikely to surpass Tesla in terms of total parameters, but they can potentially provide even greater driving autonomy and faster charging.

Main Electric Car Components and Systems

Despite the differences in layout and efficiency, electric cars of all generations have much in common in terms of design: they are equipped with almost identical sets of main components and units. Let us take a look at each of them.

Electric motor. It is the main unit of any BEV. The electric motor operates on the following principle: a mechanical force acts on a current conductor placed in the magnetic field, which, in turn, rotates its shaft due to electromagnetic interaction of the moving component (rotor) with the stationary housing (stator). This can be achieved by different methods, so electric motors also differ in design.

Brushless motors are used for actuating electric cars. A synchronous AC generator with permanent magnets used as a rotor is considered to be the most efficient example. The drawbacks include price (rare metals are used for the production of magnets) and difficult steerability due to the constant magnetic field. Therefore, these engines are used in expensive and powerful electric vehicles, such as Porsche Taycan and Tesla Model S.

Electric motors with induction coils replacing magnets, which also operate under alternating current, are used more often due to their lower price. They can be synchronous (e.g. Renault Zoe), but more often the rotor rotates slower than the magnetic field created by the stator coils. Because of this, such engines are called asynchronous. They have lower efficiency, but they are easier to operate. Audi e-tron, for example, is equipped with such engines.

Gearbox. All motors used in electric cars develop very high torque - they can spin up to very high speeds literally from the start and change the direction of rotation.  That is why electric cars do not need complex multi-speed gearboxes and heavy transmission like cars with ICE. A simple and reliable reduction gearbox (often represented by a planet gear) connected directly to the engine would be enough. Powerful and fast cars can additionally be equipped with a two-range gearbox combining powerful traction at low speed and a high maximum speed.

Traction battery. It is the most expensive component of the electric car. Nowadays, it is a set of simple batteries (cells) controlled by an entire system of microcontrollers. Batteries differ in capacity, operating voltage (for EV – from 350 to 800 V), as well as the shape adapted to the layout of a specific electric car model. They also have different cells, which can be manufactured using different materials. For example, nickel-metal hydride batteries are already considered outdated, and several types of lithium cells are considered the most popular. In the future, there will be a new generation of batteries, which are now being developed by some electrical engineering companies.

Inverter. This device connects the electric motor and the battery. The name implies that the main purpose of this unit is to convert the current, since the battery generates and receives direct current, while the motor operates on the alternating current. However, the functions of this "box" are much broader: it controls the longitudinal acceleration and deceleration of the electric car with a help of a pedal, regulating the flow of energy from the battery to the engine and back (during recovery when braking).

Battery. It would seem that with such a powerful energy source, the electric car no longer needs a regular 12-volt battery, but it is still present. A standard and maintenance-free low-voltage subsystem is required for the operation of on-board electronics and lighting equipment, electric amplifiers, actuators, compressors and other drives. Everything as in an ordinary car. 

Cooling system.The electric motor is much less heated and does not require powerful cooling. However, each BEV still has both radiator and heat lines system necessary for a traction battery. After all, it works most effectively only in a limited temperature range. A heavy load, frequent discharge-charge cycles while driving or during high–speed charging with strong currents, it heats up strongly. Temperature control may also be necessary for an inverter that passes very high-strength currents.

At the same time, the cooling system operating in the "heat pump" mode (like an indoor inverter air conditioner) can provide comfort inside the car with minimal energy consumption.

Charging unit. Charging the electric car is actually a much more complicated process than it may seem, so the cars have a separate electronic unit to control it. The electric car should be able to be charged from various sources - from the household outlet to extra-powerful charging facilities that, in turn, are developed according to different standards: European, American, Japanese and Chinese. Unfortunately, there is still no single world standard for charging stations. Some charge the batteries using AC, others make use of more powerful DC practically bypassing the inverter. The charging method also affects the time necessary for the battery replenishment.

Brakes. Theoretically, BEV could do without usual braking mechanisms and make use of power resistance created by the electric motor in generator mode. But actually all electric cars have brake pads, discs, water pipes with hydraulic fluid, etc. However, due to lower load, the brakes of electric cars wear out much more slowly.

The Future of Electric Cars

Most car manufacturers have already prioritized the development of electric vehicles. Moreover, they work not on their own but actively cooperate with chemists and electrical engineers. Every year, the companies increase the battery capacity and reduce their cost, improve electric motors, etc. The further we go, the more electric cars with better value for money will be available.

The charging infrastructure is being actively developed as well. In particular, the high-speed charging stations offer higher charging speed and charging networks expand. For instance, our GO TO-U team is now trying to reduce queues at charging stations. Thanks to modern technologies, this problem is gradually being solved: the GO TO-U app helps not only find the charger on the map, but also book it for a certain time at the necessary location. 

In China, the electric cars with standardized replaceable batteries are gaining popularity, as this is one of the ways to shorten the charging time. BEV drives into the box, where a robotic mechanism removes an empty battery and puts a charged one in its place. It is done automatically, without human intervention, and takes the same time as a full refueling of a conventional car. It is possible that such an EV concept will be in demand in large countries in the future.

Contactless charging, similar to those used for smartphones, is another promising trend. For this purpose, the electric car and parking spaces for electric transport are equipped with powerful inductors that can be turned on automatically.

Engineers are also developing a mechanism for contactless energy transfer: the electric car is charging while driving from a winding hidden under the roadway. However, this technology may be too expensive and not effective enough.

The improvement of batteries will remain the main vector of development in electric cars sector. It is estimated that if manufacturers manage to increase their capacity by a third (at the current size and weight), and the cost of batteries decreases by half, then cars with ICE will immediately lose to BEV in this competition. After all, absolutely fantastic ways of storing electricity can still make a hit, e.g. the technology of recharging wet-cell batteries with a "supercharged" replaceable electrolyte.

As a Conclusion, we Can State the Following

  • Electric cars were introduced even earlier than conventional cars, and in the first years they even won in the marketplace. However, later they disappeared. Their return was marked by the advances in electrical engineering and the worsening of the environmental situation in the world. It took almost a century.
  • Initially, electric cars of the "new era" were too expensive, heavy, and slow. Their power reserve was not large enough for everyday use.
  • Thanks to the improvement of batteries and electronics, electric cars have actually caught up with ICE cars in terms of performance and power reserve. This became possible due to new layouts designed exclusively for electric motors.
  • In addition to the electric motor and battery, the EV parts include an inverter, a cooling system, a reduction gearbox, a charger, and a conventional battery that powers the car electronics.
  • The advantages of electric cars include high efficiency (particularly, due to energy recovery), complete absence of emissions, easy wheel drive, cheap maintenance and operation, particularly due to the low cost of electricity.
Mar 23, 2022
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