Technical discription of e-bike

6.1 Hardware Design

6.1.1 Automotive Alternator

The car alternator is possibly the most vital factor or piece of the design. Without the alternator, there would be no supply of mechanical electricity to run the electric tricycle. After deciding on an automobile alternator to be the motor for the design, it was vital to choose the right stator coil orientation that satisfactory match the design. The
figure under indicates a frequent car alternator and its foremost components.

The predominant hardware factors that utilized inside the car alternator are the rotor and the stator. The rotor of the alternator consists of a coil of wire wrappedaround an iron core. DC subject contemporary produces a magnetic area round the core. The stator is a set of coils constant to the shell of the alternator. Magnetic discipline from the rotor couples to the stator coils producing modern in the stator windings. These stator coils are positioned one hundred twenty levels apart, producing three separate phases. The automobile alternators used in this layout are of the hybrid brushless variety, having no expensive, inner uncommon earth everlasting magnets. Instead, the motors require that a small quantity of modern-day be surpassed via brushes to a coil in the rotor in order to magnetize it. Current is then utilized to the outer stator coils in order to result in an electromagnetic pressure to flip the rotor. The stator has 36 coils round its perimeter. The test alternators have 36 coils that are wired into three phases related in a “delta” pattern such that every section has 12 coils and every coil is separated by using 10 tiers round the stator. The first step in the hardware layout manner was once to decide the most positive way to orient the stator coils in the alternator. As stated above, the alternator was once originally connected in a delta configuration. Delta configuration lets in for decrease voltage but higher current. The parent beneath indicates a delta connection and a Wye connection with a common.

WYE CONNECTIONS STAR & DELTA

In order to exactly pulse solely one stator coil at a time, the alternator used to be reoriented To a Wye connection with a frequent wire. This used to be much less resistive than the delta connection and allowed for greater modern-day to skip via the stator windings presenting greater RPMs.
The first take a look at that used to be run with the alternator earlier than any hardware or software program used to be developed was once a connection of the rotor subject coil to a 12V battery, and the connection of every stator section to both 12V or ground. A present day limiting resistor of 1Ω was once positioned from the energetic stator coil to floor in order to restriction the modern-day and the torque in the alternator. This used to be carried out strictly for checking out functions and was once eliminated in the ultimate design.
This check used to be carried out in order to locate the alternator stepping states. This was once a critical design system due to the fact the software program code makes use of this stepping principle in order to know which stator coil to pulse in order to rotate the rotor shaft. When these connections were made, every stator segment turned around 10 stages when linked to the batteries. This covered 30 ranges in three phases and by means of activating the identical three phases with the contrary polarity, the subsequent 30 tiers ought to be covered. This sample then repeats 6 instances each 60 degrees to make a full 360 diploma rotation. Because of the Wye configuration of our motor, one end of every stator coil is uncovered as an exterior connection. These three external connections are arbitrarily labeled Black, Green, and Red. The different cease of all three coils are linked collectively and uncovered as a single “common” exterior connection. The following desk describes the connections required to flip on on the three stator coils to rotate the rotor 60 stages in one direction.

6.1.2 MOSFET Switching Circuit

After the alternator pulsing states have been understood, the subsequent step in the diagram process was to strengthen a MOSFET switching schematic to interface with the microcontroller and the software program in order to pulse unique stator coils with modern-day at precise moments in time. P-channel and n-channel MOSFETs have the functionality of turning on or off depending on the gate to supply voltage difference. The discern beneath indicates the circuit image for a p-channel MOSFET.

P-CHANNEL AND N-CHANNEL MOSFETs

The p-channel MOSFETs are the pinnacle row of MOSFETs in the circuit graph with their sources related to the 12V provide line. The drains of the p-channel MOSFETs were connected to two LEDs (one pink and one green) in parallel and oriented in reverse to simulate the stator coils. If the pinnacle LED became on, then it used to be regarded that present day used to be flowing from the left facet of the circuit to the proper side, and vice versa for the different LED. The n channel MOSFETs are the backside row of MOSFETs with their sources connected to the floor line and their drains additionally related to the stator coil LEDs. As mentioned earlier, in order to flip on the MOSFETs, a voltage wished to be utilized to the gates of the MOSFETs. For the p-channel MOSFETs, the Vgs, or the gate to supply voltage needs to be higher than 3V to flip on. Therefore, in the demo Team 9 shorted the gate and the source collectively to flip the p-channel MOSFET off. In order to flip it on, the gate voltage was pushed with the aid of 5V. For the n-channel MOSFETs, they have been grew to become off with the aid of shorting both the gate and the supply to ground. In order to flip them on, a voltage of 5V was once applied to the gate. For example, if the purpose is to flip on LED A in the circuit layout above, the p-channel MOSFET labeled “1” wishes to be grew to become on, and the n-channel MOSFET labeled “2” desires to be became on. This lets cutting-edge float from the supply of “1” through
the LED “A” and down to ground, or the supply of “2”. This is how every stator nation is pulsed with present day and activated.

6.1.3 Battery Connections

The terminal block on the left has connections to floor (negative terminal of the battery), bad slip ring of the rotor, fine slip ring of the rotor, and the 12V battery positive terminal. The 12V fantastic terminal and the fine slip ring of the rotor were shorted collectively seeing that each the rotor and the circuit are each provided with 12V. The 2d terminal block is for the connection to every of the stator coils. There are four phases in the Wye linked alternator with a common. These have been named black, green, red, and common. In order to make certain that a invulnerable and rugged connection used to be made to the battery terminals, eyelet connectors had been used. Other hardware safety strategies had been made as well. In order to make certain that solely a particular quantity of present day was once drawn via the circuit for the prototype, a 20A circuit breaker was once positioned at the poor terminal of the
battery. Another safety requirement used to be to make certain that the MOSFETs have been included from heat. To meet this requirement, giant metallic warmness sinks had been connected to the drain tabs of each MOSFET. The determine beneath suggests these warmth sinks. Later in the sketch process, a heat sink used to be additionally introduced to the n-channel MOSFET in the rotor circuit.

6.1.4 THROTTLE

A throttle was once wanted to supply a person interface to the motor. The throttle wished to be rugged and bike mountable. The throttle is the Electric Scooter Throttle, Type2 by Parts for Scooters proven in Figure 26. This throttle makes use of a Hall impact sensor, rather of the variable resistor on occasion determined in electric powered throttles. Twisting the throttle varies the strength of the magnetic subject adjoining to the sensor, which sends a corresponding voltage between .74V and 4.15V to the microcontroller. By the usage of the corridor impact sensor, the throttle is extra rugged and dependable as there are no transferring electrical components, in distinction to the variable resistor which can put on over time.

Technical Roles, Responsibilities, and

Work Accomplished

 SHIVAM SHUKLA

The sketch group we hooked up used to be in part cut up into two subgroups, hardware and software. This was once to expand the effectivity of the group so that two components of the project could be developed simultaneously. As an mechanical engineer, I was once phase of the hardware subgroup which was once broadly speaking targeted on mastering how the specific alternator parts worked, growing a MOSFET switching circuit, and creating an environment friendly PCB layout for the remaining design. The first step taken at some point of the semester used to be to decide how to make the alternator spin. To do this, I helped manually connected a 12V vehicle battery to every segment of the stator coils to make the alternator act comparable to a stepper motor. As the group leader, I additionally found the total work every day and take a look at all calculations and section dimensions. I additionally carried out each week development work to our co-ordinator sir. I additionally helped to set up of software program in our gadget and helped to established motor, car alternator and battery connections.


 SRIJIT DWIVEDI

Along with the challenge administration role, I was once additionally continually worried with the technical component of the mission as the hardware layout lead. Throughout the semester, I set up hardware conferences in order to talk about technical specs and sketch issues. On the hardware side, I designed the MOSFET stator switching schematic alongside with the rotor circuit and the peripheral connections to the microcontroller on the EAGLE
schematic software. After designing the schematic, I equipped the aspects on the board file and successfully routed the PCB traces and bias. After the fabrication of the board, I used to be worried in the thing soldering and additionally in the connection of the software program and hardware. After connecting the hardware and walking tests, I was once in cost of hassle taking pictures the hardware in order to locate easy changes that wished to be made. I essentially labored on set up of electrical gadget and circuit design.


 KRISHNA YADAV

In this project, I essentially works on e-bike parts shopping. I additionally specific the new idea’s and technological know-how about our project. Every remaining day of week, I invited team for dialogue and share the challenge development to every other. I was once additionally assist to putting in MOSFETs. At this factor we have been capable to combine the hardware and software program subgroups to assemble our prototype. The closing steps in this assignment earlier than layout day are to optimize our software program algorithm to make the motor run the most efficiently, as properly as put together the prototype for demonstration. . I additionally have been suggesting new format changes such as mild changes to the stator quadrature perspective primarily based on alternator overall performance in the course of testing. I was once additionally actively concerned with the stator and rotor pulsing theory.

 ANAND YADAV

In this project, I essentially labored on section installation. Proper checking the all section dimension, his slicing and welding and after correction of all components his set up was once my fundamental work. I additionally assist to buy the section from market in minimal rate as possible. I additionally assist to set up of MOSFETs. Once we figured out the sequence of the stator coils to make the alternator entire a full rotation we should start to diagram the excessive voltage MOSFET switching circuit. The first step in this method was once to confirm the flip on voltage of the MOSFETs and decide how to safely use them.


 IMRAN AHMAD

In this mission I essentially work on calculation , phase set up and analysis. Check the all phase work desirable or not. Check the suitable velocity calculation of motor and car alternator. I helped the transportation of last prototype. I helped to entire all kind of set up with our crew members. I additionally labored slicing and welding of rods and shafts. Installation of throttle, sensor and electrical connection was once my essential work in the project. To scan with the MOSFETs, I helped create a proof of thinking switching circuit with LEDs appearing as the stator coils for protection purposes. Since the MOSFETs would be handing a lot of present day we introduced warmth sinks to dissipate the strength misplaced to heat.