Óêðà¿íñüêà   Ðóññêèé
 

Abstract

Content

Introduction

Every day on our roads, the number of cars increases, with this progress the volumes of poisonous and polluting substances produced by cars are increasing in parallel. At the moment there is a paradise of reasons that does not allow you to freely switch to this type of vehicle. In my master's work, I want to pay attention to the main problems.

1. Theme urgency

To date, there are a number of reasons for the use of electric drives as traction in public vehicles.By public means of transport is meant and personal cars, as they constitute the vast majority of all vehicles[3]They also include commercial vehicles that make numerous daily trips to megacities and suburbs of large cities.In connection with the increase in cars on our roads, the situation will worsen.The hybrid plants came to their aid, the engine works in tandem with the TED, a fairly effective solution to the problem, which allows reducing costs not only for fuel, but also for servicing vehicles, as the load on many nodes decreases.However, a new series of negative, side effects arises. Among the disadvantages of the hybrid installation is its high cost.Buying a hybrid car, the consumer pays for additional units and aggregates that allow to save fuel.A set of problems can solve an electric car, where the source is a rechargeable battery. This type of transport minimizes many of the listed shortcomings of other systems[5].

2. Goal and tasks of the research

In the early part of the century, innovators in Hungary, the Netherlands and the United States - including a blacksmith from Vermont - began toying with the concept of a battery-powered vehicle and created some of the first small-scale electric cars. And while Robert Anderson, a British inventor, developed the first crude electric carriage around this same time, it wasn’t until the second half of the 19th century that French and English inventors built some of the first practical electric cars[2].

Over the next few years, electric vehicles from different automakers began popping up across the U.S. New York City even had a fleet of more than 60 electric taxis. By 1900, electric cars were at their heyday, accounting for around a third of all vehicles on the road. During the next 10 years, they continued to show strong sales.

Electric cars didn’t have any of the issues associated with steam or gasoline. They were quiet, easy to drive and didn’t emit a smelly pollutant like the other cars of the time. Electric cars quickly became popular with urban residents -- especially women. They were perfect for short trips around the city. As more people gained access to electricity in the 1910s. Many innovators at the time took note of the electric vehicle’s high demand, exploring ways to improve the technology. For example, Ferdinand Porsche, founder of the sports car company by the same name, developed an electric car called the P1 in 1898. Yet, it was Henry Ford’s mass-produced Model T that dealt a blow to the electric car[1].

While all the starts and stops of the electric vehicle industry in the second half of the 20th century helped show the world the promise of the technology, the true revival of the electric vehicle didn’t happen until around the start of the 21st century. The other event that helped reshape electric vehicles was the announcement in 2006 that a small Silicon Valley startup, Tesla Motors, would start producing a luxury electric sports car that could go more than 200 miles on a single charge [5].

Drive Train Configurations An electric vehicle is driven by at least one electric drive motor. It can be configured as a four-wheel drive vehicle or with one drive axle. Other hybrid variations are also possible. The two main concepts are described in this section.

1. Drive with in-wheel motors

2. Drive with just one electric drive motor in the central drive train

Design:

The wheels are connected directly to the in-wheel motors. The in-wheel concept is used for electric scooters, electric bicycles and electrically driven wheel chairs.

Figure 1 – The wheels are connected directly to the in-wheel motors.

Features:

• No drive shafts are required

• No differential transmission required

Advantages:

• Four-wheel drive is technically possible

• Output axles of the in-wheel motors are directly on the wheel

• High efficiency because there are hardly any mechanical losses

• Possibility of regenerative braking

Disadvantages:

• Unsprung masses in the wheel are greater than wheels on a conventional vehicle

• High mass of driven components (inertia and torque of whole vehicle affected)

• New vehicle design required

• Control is complex, both electric motors must run synchronously

• Combination with a hydraulic friction brake is still currently necessary

• Limited space on the wheel

Drive with Electric Motor in Central Drive Train

Design:

The electric motor/generator drives a transmission, the drive shafts and the wheels.

In a pure electrically powered vehicle, a reduction transmission is used. Four-wheel drive can be added with a drive shaft from the front axle. Another possibility is to use a second electric motor.

Figure 2 – In a pure electrically powered vehicle, a reduction transmission is used.

Features:

• Two drive shafts on each driven axle

• A differential on each driven axle

• Driveshaft required

Advantages

• Single-axle drive simple to design

• Four-wheel drive is possible

• Combination as hybrid drive (HEV / PHEV / RXHEV) possible

• Integration in existing vehicle concept is possible

Disadvantages

• Output shaft of central electric motor/generator is not on the drive axles.

• Differential required

• Reduction gear required

The Golf Blue-E-Motion (BEV)

Figure 3 – The Golf Blue-E-Motion

Example of 2011 Test Fleet

The blue-e-motion is a purely electric vehicle without a combustion engine. The battery can only be charged using regenerative braking or an external power source.

In addition to the high-voltage system, the vehicle has a 12 V onboard supply with its own 12 V onboard supply battery. The electric motor/generator delivering 85kW transfers the power to the drive wheels using a transmission and differential.

The driver operates the vehicle exactly the same way as a vehicle with an automatic transmission. When the selector lever is in the “B” position (regenerative braking), the system supplies the maximum possible regenerative braking when the accelerator pedal is released. The vehicle can come to a complete stop using this function - without using the brake pedal. The electric drive motor does not generate enough heat for the interior of the vehicle. Because of this, the blue-e-motion has a high-voltage heating system[1].

The Drive System

Figure 4 – Electric Vehicle's drive system

An Electric Vehicle's drive system performs the same functions as that of a vehicle powered by an internal combustion engine. The drive system is that part of the EV which transmits mechanical energy to the traction wheels causing the EV to move. The components used in an EV are very different from a standard vehicle. In an EV, a transmission is not necessary. A transmission in a standard vehicle is used to give the vehicle a certain torque or power at certain speeds by changing the gear input/output ratio within the transmission. The change in gear ratio is governed by the speed(RPM) that the vehicle's power plant, or engine, is turning. Because there is a mechanical shift from one set of gears to another, a jolt is usually felt by passengers as speed is increased or decreased and the transmission shifts to larger or smaller gears.

EV's utilize an electric motor to turn the wheels of the vehicles. There are several different drive system designs in use today. These include vehicles with a single large electric motor coupled to the rear wheels through a differential housing. Other designs utilize two smaller motors to power each wheel separately through independent drive shafts[2].

The most efficient design to date utilizes motors which are attached directly to the wheel. These are referred to as "wheel motors". By eliminating driveshafts and differentials, mechanical losses between the motor and wheels are kept at a minimum.The power system of an electric vehicle includes both the drive system and control system. The controller delivers power to the motor from the batteries. The motor in turn delivers power to move the vehicle to the drive wheels through a gearbox.

Control Systems

The most complex and important system in an EV is the control system. The control system is responsible for governing the operation of the electric vehicle. The control system receives inputs from the operator, Controllerfeedback signals from the motor controller and motor and also feedback signals from other systems within the EV. The speed at which the control system must receive data from other systems, process the data in an algorithm and output a response to the given conditions must be accomplished in milli-seconds. This requires the control system to have a microprocessor, just like a computer, to accomplish its tasks. Though no two control systems are identical, most of the feedback signals are similar. The table below lists common components of a control system and the feedback signals that are sent to the microprocessor[2].

References

  1. Basics of Electric Vehicles Design and Function // Volkswagen Group [Ýëåêòðîííûé ðåñóðñ]. – Ðåæèì äîñòóïà: www.Volkswagen Group of America ñâîáîäíûé.
  2. Electric Vehicles // utc.edu [Ýëåêòðîííûé ðåñóðñ]. – Ðåæèì äîñòóïà: www.utc.edu ñâîáîäíûé.
  3. Ýëåêòðîìîáèëü// wikipedia [Ýëåêòðîííûé ðåñóðñ]. – Ðåæèì äîñòóïà: ru.wikipedia.org ñâîáîäíûé.
  4. Ýëåêòðîìîáèëü Tesla // Tesla Motors [Ýëåêòðîííûé ðåñóðñ]. – Ðåæèì äîñòóïà: www.tesla.com ñâîáîäíûé.
  5. Tesla Motors – ýëåêòðîìîáèëè, êîòîðûå ìîãóò èçìåíèòü ìèð // itc.ua [Ýëåêòðîííûé ðåñóðñ]. – Ðåæèì äîñòóïà: www.itc.ua ñâîáîäíûé.
  6. Ýëåêòðîìîáèëü – ïðåèìóùåñòâà, íåäîñòàòêè, ïåðñïåêòèâû // innoeco.ru [Ýëåêòðîííûé ðåñóðñ]. – Ðåæèì äîñòóïà: www.innoeco.ru ñâîáîäíûé.
  7. Óñòðîéñòâî ýëåêòðîìîáèëÿ // hybmotors.ru [Ýëåêòðîííûé ðåñóðñ]. – Ðåæèì äîñòóïà: www.hybmotors.ru ñâîáîäíûé.
  8. Ñèñòåìû äëÿ ýëåêòðîìîáèëåé (EV) è ãèáðèäíûõ ýëåêòðîìîáèëåé (EV) // toshiba.semicon-storage.com [Ýëåêòðîííûé ðåñóðñ]. – Ðåæèì äîñòóïà: www.toshiba.semicon-storage.com ñâîáîäíûé.