Regenerative Braking For Vehicles Engineering Essay

The intent of this undertaking was to develop a PEM fuel cell loanblend system which maps as a regenerative braking system. Using fuel cell engineering and the constructs of regenerative braking, this undertaking aims to minimise energy loss and change over this energy into energy that can be used once more. Fuel Cell engineerings are expected to shortly replace the traditional power generators for residential applications. Using a PEM Fuel Cell, an ultra-capacitor, and a battery cell, this undertaking made usage of energy in such a manner that power was utilised with greatest efficiency. As the vehicle moves up a incline from a stationary place, it uses the ultra-capacitor to thrust itself and so uses the motor to increase its velocity. As the velocity stabilizes, the battery is used to keep a changeless velocity. The hereafter of such fuel cell intercrossed vehicles is something that is already go oning in today ‘s scientific chase but what this undertaking aims to detect is how the combination of different power beginnings influences the efficiency of the electrically powered vehicle. For farther survey, more energy efficient fuel cell engineering intercrossed systems can be studied in order to supply a purer planetary environment.

Introduction

The construct of regenerative braking is non one that is unheard of in today ‘s chase of scientific discipline, engineering, and mechanization. It has become a field that has already been ventured into and it is, hence, really plausible to detect electric vehicles around us which work utilizing a regenerative braking system. However, what this undertaking aims to cover is somewhat different. This undertaking aims to prove regenerative braking utilizing a selective power beginnings and step the efficiency. As H fuel cells are fundamentally clean cells, they can be used to power most electric vehicles, hence cut downing the dependance on oil but, the ground this thought is non in widespread usage is due to the fact that fabricating fuel cells are “ prohibitively expensive. ”

In this undertaking, three different power beginnings were used. These include the ultra-capacitor, fuel cell, and the battery. As the ultra-capacitor and the fuel cell are regenerative power beginnings, they are suited power beginnings for this experiment. A typical fuel cell combines H and O to bring forth H2O and electricity. Electrolysis is what happens when the procedure is reversed. Extremist capacitances on the other manus shop electrical energy by physically dividing the negative and positive charges. Ultra capacitances tend to bear down and dispatch instead rapidly and easy. Due to this peculiar feature of extremist capacitances, they can non power a vehicle for long continuances. It is when the vehicle needs to go up a incline from a stationary place that the extremist capacitance comes into drama. A battery, by contrast, chemically separates these charges. An extremist capacitance can be reused over and over once more without a alteration in its public presentation degrees. Using this belongings of an extremist capacitance, it was used to supervise the public presentation of the rhythm at different velocities. As the vehicle requires a great sum of power to thrust frontward, the extremist capacitance can be used to supply the power for that certain distance. While the extremist capacitance was used in the testing processes of the rhythm, the battery was chiefly used to modulate a smooth tally. ( Lampton, 2011 )

Methods and Materials

As it is instead easy for each single study to overlap in footings of content, each group member is concentrating on a different set of subjects in his/her study in the group.

2.1 The Procedure of Regeneration

Each clip a auto or any vehicle ‘s interruptions are exerted, some sum energy is wasted. Harmonizing to the Law of Conservation of Energy, energy can ne’er be wasted. It has to be converted to one signifier to the other. In the instance of a vehicle decelerating down, the kinetic energy produced by the vehicle must be transferred to another signifier. But, this energy ends up as heat and is efficaciously wasted.

Over the past few old ages, research workers in the field of power coevals have devised different sorts of braking systems that could be used to cite up most of the auto ‘s kinetic energy and change over it to electricity so that this electricity can later on be used to reload the auto ‘s batteries. This is what is termed as regenerative braking. This generated energy is stored in a storage battery and subsequently used to power the motor whenever the vehicle is in its “ electric manner. ”

Traditionally, brake tablets are used to bring forth clash with the brake rotors in order to decelerate the vehicle. Due to this, extra clash is created between the “ slowed wheels and the surface of the route. ” This is basically how the auto ‘s kinetic energy turns into heat. By presenting regenerative braking, the system that drives the vehicle does the bulk of the braking. As the driver stairss on the brakes of any “ electric or intercrossed ” vehicle, the brakes really change by reversal the electric motor therefore decelerating the vehicle ‘s wheels. This electric motor besides acts as an electric generator when it is reversed. Due to this peculiar feature, it produces electricity that is subsequently fed into the vehicle ‘s batteries. ( Lampton, 2011 )

In our undertaking, three power beginnings were used viz. the fuel cell, the battery and the extremist capacitance. These three beginnings were ordered from outside. Equally shortly as the power cells arrived, our group got to working together on attaching the beginnings onto the bike. Along with these beginnings, we besides required a speed indicator and a GPS tracker in order to cipher the velocity and to detect the path, severally.

Speed ( m/s )

Energy ( J )

Voltage across the Capacitor ( V )

Energy

Efficiency ( % )

1.94

37.636

0.034

0.0335

0.08901052

2.22

49.284

0.059

0.1009

0.20473176

2.5

62.5

0.251

1.827

2.9232

2.78

77.284

0.285

2.3555

3.04784949

3.06

93.636

0.335

3.2545

3.47569311

3.33

110.889

0.356

3.6753

3.31439548

3.61

130.321

0.394

4.5018

3.45439338

3.89

151.321

0.443

5.6912

3.76101136

4.17

173.889

0.459

6.1097

3.51356325

4.44

197.136

0.555

8.9327

4.53123732

4.72

222.784

0.633

11.62

5.21581442

5

250

0.7

14.21

5.684

5.28

278.784

0.773

17.328

6.21556474

5.56

309.136

0.899

23.438

7.58177631

Figure 1: Table with the Calculated Experimental Values

By and large, regenerative braking systems tend to exponentially increase a system ‘s fuel efficiency These systems are besides critical in increasing the scope of each vehicle. In pure electric autos, regenerative brakes are critical to increasing scope and acquiring the most out of each charge.

The Motor as a Generator

Regenerative braking is tried on “ intercrossed gas/electric cars ” to remember a part of the energy lost during braking. This summoned energy is subsequently used to power the motor anytime the auto is in electric manner. In the procedure of regenerative braking, motors function as generators and the end product is transferred to the burden and this in bend amplifies the braking consequence.

2.3 The Restrictions of Regenerative Braking

If regenerative braking is ideal for most vehicles, why is it that a bulk of the vehicles seen on the route today prefer to utilize the traditional signifier of braking? The consequence of Regenerative braking tends to drop at lower velocities. Along with the regenerative electric brake, the vehicle besides requires the normal clash brake in instance of a failure. Regenerative braking might non go on if any other electric portion on the same supply is pulling power from battery or capacitances. Therefore, dynamic braking is used to soak up the extra energy. Dynamic braking is required to absorb the extra energy in order to let a “ satisfactory exigency braking public presentation. ” ( Blanco,2011 )

Consequences

In this experiment, my function consisted chiefly of taking note of the computations and measurings after the experiment was conducted. Apart from the initial

Kinetic energy can be calculated utilizing the expression: . Once the brakes are applied, kinetic energy is converted to clash force where the consequence is tantamount to Force*Displacement. Once this clash force is created, it is stored in an ultra-capacitor whose electromotive force can be formulated by: 1/2CV.

Comparing Kinetic energy to the Friction Force and

= 1/2CV + FS

In the experiment, utilizing the electric bike, we measured the energy generated when the brakes were exerted from 20 km/hr to 0 km/hr. Along with energy, our group calculated the charging and discharging of the extremist capacitance as the brakes were applied.

Figure 2: A brief diagram of the circuit used in the electric bike dwelling of two resistances, an extremist capacitance and a generator.

Figure 3

Using the graphs above, it is apparent the electromotive force generated from braking is non sufficient to power up the motor of the vehicle.

Decision

The intent of this experiment was to fundamentally come up with PEM fuel cell loanblend system which maps as a regenerative braking system. With the shift of the power beginnings, the electric vehicle is tested for the minimum loss of energy. As the consequences show, the energy stored in the extremist capacitance is instead little and hence the regenerative braking requires multiple bear downing in order to achieve the power of 37V to power the electric vehicle. The hereafter of such fuel cell intercrossed vehicles is something that is already go oning in today ‘s scientific chase but what this undertaking aims to detect is how the combination of different power beginnings influences the efficiency of the electrically powered vehicle. Further integrating of antilock braking systems would pave manner for the motor accountant to take over the country of braking. With such possibilities in the field, it is certainly an exciting country of scientific discipline to work in.