As many experts say, the electric car today is not just an alternative, and is already in direct competition with the conventional internal combustion engine.
Of course, we are not talking about mass displacement of internal combustion engines yet, however, experts believe, that it is only a matter of time. The point is, that against the background of the global environmental and fuel crisis, electric vehicles have every chance to push piston engines into the background.
Moreover, judging by the number of projects and the amount of money invested in the development of electric cars, then involuntarily the conclusion arises, that the car manufacturers themselves predict a great future for electric cars.
In this article we will consider the device and the general principle of operation of vehicles on electric traction, their features, Advantages and disadvantages. We will also try to understand, which option is best, electric car or hybrid, what is better to choose in a given case, etc.. d.
Electric cars: features of electric cars
Let's start with that, that until recently, cars with a hybrid engine from Toyota and others were actually one of the most desirable, popular and widespread options around the world. You don't have to go far for examples, as it is enough to mention the premium model Lexus RX450h F Sport or more modest and affordable Toyota Prius and t. d.
At the same time, even today the situation has not changed much, although a large number of competitors have recently appeared on the market, which are able to offer consumers different versions of the so-called "green" cars.
The point is, that for all its advantages cars with hybrid engines still represent an inseparable symbiosis of electric motors and internal combustion engines. This means, that it is more about fuel economy, while "zero" emissions into the atmosphere and the complete abandonment of petroleum products when using such machines still can not be achieved.
Reciprocating engine, which cannot be excluded from the general scheme of the hybrid, continues to need fuel, its lubrication system requires engine oil, etc.. d. For this reason, a hybrid power plant can be considered rather the next round of evolution of the internal combustion engine, but by no means a full-fledged alternative.
Given the above, it becomes clear, that to date, the rejection of the internal combustion engine can only offer a fully electric car. By the way, the idea is far from new, since the first electric cars appeared even before vehicles with internal combustion engines.
However, at the initial stage, the creators of electric cars faced a lot of problems (small power reserve, heavy weight, the difficulty of charging the batteries, etc.), as a result, this option did not compete, and gasoline and diesel engines quickly and for a long time supplanted electric cars.
Everything has changed relatively recently, in particular due to the development of modern technologies and the creation of the necessary devices for the accumulation and storage of electricity. In simple words, we are talking about energy-intensive batteries for electric vehicles, as well as solutions for their quick recharging.
As a result, the electric car has recently become a publicly available serial product. Such cars nowadays are made in Japanese and European, American, as well as Chinese manufacturers. The popular electric car Nissan Leaf should be singled out, well-known models Tesla Model S and Roadster, and the Toyota RAV4EV, BMW Active C, etc.. d.
Scheme of the device of the electric car
Let's start with that, that the design provides much less moving parts compared to internal combustion engines. In other words, the electric car is arranged easier, and simplicity always means increased reliability.
The main structural elements are:
- battery
- electric motor;
- simplified transmission;
- special charger on board;
- inverter and dc converter;
- developed electronic control system;
The battery in electric cars is required to power the electric motor. This traction battery is now lithium-ion and consists of modules (cans), which are connected in series. As for capacity, different options are available on different models. Usually, the battery is selected to the car based on the power of the electric motor.
The traction motor creates torque on the car's wheels and is a synchronous or asynchronous three-phase AC motor (asynchronous), issuing an average of 20 to 150 kW and more. Note, that the efficiency of the electric motor is much higher than the internal combustion engine, especially petrol. In other words, losses of useful energy in the internal combustion engine can reach 70%, while the electric motor is lost only 10%.
As already mentioned, the electric car is driven by electric motors, which may be several. The electric motor is usually powered by a rechargeable battery, it is also possible to use solar panels, etc.. P. However, in practice, serial electric cars are often equipped only with a rechargeable battery.
Such a battery needs charging, which can occur both from an external source, and while driving an electric car. In the second case we are talking about the recovery of braking energy.
so, the main advantages of the electric motor can be considered the available maximum torque at any speed, such an engine can turn the wheels back and forth without the need to install additional solutions. Also highlight the lack of need to cool such an engine, the electric motor is capable of performing the functions of a generator, etc.. d.
Usually, in electric cars today several electric motors are installed at once (on each wheel). As a result, traction is significantly improved compared to the scheme, which provides equipment with one electric motor.
There are also solutions, when the electric motor is actually installed in the wheel. On the one hand, transmission in this case is simplified as much as possible, however, the number of unsprung masses increases and the overall controllability of the machine suffers.
By the way, transmission of electric cars in itself is simple at first and often represents a one-stage gear reducer. As for the charger, the solution is located on the car and allows you to charge the battery, and from the usual electric socket. There is also a separate "exit" for fast battery charging at special stations.
The inverter serves that purpose, to implement the conversion of direct current from the battery into three-phase AC voltage. This is the current required to power the electric motor.
We will note still, that in a design of electric cars the similarity of well-known to motorists of joint stock bank on is included also 12 Volt. In this case, the DC converter is responsible for charging such an additional battery, and the battery itself is needed to power various on-board devices and systems (power steering, dimensions and headlights, climatic installation, heated windows and seats, audio system with acoustics, etc.. d.).
Electronic system, which plays the role of ECM in the electric car, has a set of features. The system is responsible for active security, controls the operation of electric motors, monitors the condition of the traction battery and the charge level, determines energy consumption and activates energy saving modes while driving, etc.. d.
Speaking of devices, there is a control unit (similarly to the ECU) and a large number of sensors, as well as various actuators. Sensors record the speed of the car, degree of load on electric motors, as well as the position of the accelerator pedal, brakes and a number of other parameters.
Signals from the sensors come to the controller, after which the unit strives to create the best possible conditions for a particular mode during the movement of the electric car. The driver can also observe speed information on the instrument panel, charge consumption, residual charge, how many kilometers you can still drive, etc.. d.
Types of electric cars and practical operation: pros and cons of electric cars
World automakers in this area today go two ways:
- completely new models of electric cars are created;
- there is a transformation of cars already available in the line of the manufacturer into electric cars;
More electric cars can be divided into several types. As in the case of internal combustion engines, cars have long been divided into urban minivans, sports cars, etc.. P. The situation is similar with electric cars.
- There are electric cars, which are positioned as a solution exclusively for the city. The maximum speed in such vehicles is relatively low (a little more 100 km / h), as well as a relatively small power reserve (70-80 km.) in the modes of average and high loadings.
- It is also necessary to highlight the "universal" option. Such electric cars are able to accelerate to 140-160 km / year, autonomy is also increased. This allows you to travel on the track.
- As for the sports versions, such electric cars have a speed of about 200 km / h and above. Acceleration dynamics are also very impressive. Example, Today, Tesla electric cars are able to score "a hundred" less than 3 sec, and the maximum speed of the fastest electric car in the world, which was built on the basis of the Chevrolet Corvette by the American company Genovation, during tests in 2017 year passed for 300 km / h.
It would seem, such cars came very close in a number of important indicators to cars with internal combustion engines. At first sight, electric vehicles have sufficient autonomy and acceptable acceleration dynamics. You can also highlight the ease of operation, low maintenance and maintenance costs, which should definitely persuade smart consumers to choose an electric car. However, in practice everything looks a little different.
Let's note at once, it is the peculiarities of operation and a number of other factors that still do not allow electric cars to become a mass solution. First of all, the cost of such transport continues to be quite high compared to competitors with gasoline or diesel engines.
Moreover, the efficiency of modern diesel engines allows these units to seriously compete not only with gasoline cars, but also with electric cars. That should be singled out, that from the household socket the battery of the electric car is charged for a long time, and fast recharging stations are not common due to poor infrastructure development. This is especially true for the CIS countries.
As for autonomy, those data, which are declared by the manufacturer, often not quite true. First, in practice, especially in the cold season, the battery discharges faster.
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Others, if the driver practices dynamic driving, then the full battery may not be enough on 70-80 km. in the city, and only on 40-50. To confirm this information, just read the real reviews of Nissan Leaf owners, as this budget version of the electric car at the price is one of the most accessible and today the most widespread.
In simple words, the mileage of the electric car without recharging is not constant, and depends on many factors, starting from the condition and capacity of the battery and ending with the driving style. If you add to this the use of air conditioning, dimensions, heating and other solutions, then on one charge, even under ideal road conditions, mileage will inevitably be reduced by 20-30% and more.
If the driving style is active (constantly exceeds the average speed 60 km / year), then it is quite possible to count on everything 50%. It turns out, if the manufacturer promises 140-160 km on a single charge, then this figure involves driving at a speed not exceeding 70 km / year, and then on condition of a fully functional battery (without losing battery capacity).
However, if you accelerate the electric car, example, to 130 km / h on the highway, then the run without recharging will be everything 70 km. As you can see, if it is still acceptable for the city, then use an electric car for country trips is quite difficult.
Now a few words about the battery. Battery, which is widely used today lithium-ion. Its production requires large costs, which strongly affects the total cost of electric cars. The service life of such batteries is limited to an average mark of about 5 years.
This means, that although the basic cost of maintaining an electric car is several times lower than its counterparts with internal combustion engines, higher initial cost and the need to replace an expensive battery (in the middle, across 5 years) question the economic benefits and feasibility of purchasing such a car. To this should be added the constant rise in electricity prices, it also affects the cost of owning an electric car.
As a result
Given the above, it becomes clear, that the active introduction of innovative technologies has significantly increased the autonomy of modern electric vehicles. However, the use of such technologies greatly affects the final cost of the vehicle, not allowing to make it a mass solution.
As for the more affordable versions, batteries, charging time from home network is close 7-8 hours, as well as a small range continue to remain weak points of such electric vehicles.
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It should also be noted, that not in all countries there is an active development of infrastructure in the form of special stations for fast charging or replacement of batteries. There are also cases of specialized services for the repair and maintenance of electric vehicles. If in Europe and the United States this issue is given much attention, in the CIS, Unfortunately, it is still impossible to talk about creating acceptable conditions for the normal operation of electric cars.
It is possible, that the situation will change soon, however, today the electric car on domestic roads remains a rarity. Usually such a car can be found in large cities. At the same time, well-off owners often buy electric cars faster for entertainment, than for practical purposes.
In other words, for the vast majority of drivers, the electric car should not be considered as the main and permanent vehicle, especially when it comes to countries in the CIS.