Design and Control of Electromagnetic Suspension of an Electric Vehicle using Halbach Arrays.

Project Title

Design and Control of Electromagnetic Suspension of an Electric Vehicle using Halbach Arrays.

Project Area of Specialization Electrical/Electronic EngineeringProject Summary

This project consists of an Electric Vehicle (EV) that is suspended in free space by Lorentz force. Faraday law and Lenz’s law are the base for the generation of lift force that is due to strong rotating flux created by the movements of neodymium magnets at the base of EV. MEMS sensor is used to measure the rate of change of motion through a gyroscope and the tilted angle of EV in the Cartesian coordinates system. MEMS sensor coverts the quaternion values into numerical values, which are read by the ATMega328p processor through an I2C communication protocol. The MEMS sensor being used in this system is “MPU-6050”, it consists of a 3-axis accelerometer and a 3-axis gyroscope, providing in total 6-Degree of Freedom (DOF). The balancing of EV will be achieved using a PID controller by utilizing the values obtained from an MPU6050 sensor.

The aerodynamics of EV will be analyzed and laws of motions will be used for the movement of EV in all directions. The effect of resistance will be reduced by a massive amount, such that a very small amount of force will be required to get the EV at a non-zero velocity. Bluetooth module HC-05 will be used along with an Android Mobile APP for communication between the EV system and the user. Android app will be custom made; mit-app inventor software will be used to build this application. The motion and other features of EV will be controlled by the user through the android application via Bluetooth. Intelligent algorithms will be designed to protect the EV system in case of a system failure or external disturbances.

Project Objectives

Halbach array:

A new configuration of a DC motor/generator is based on a Halbach array of permanent magnets. This motor does not use ferrous materials so that the only losses are winding losses and losses due to bearings and windage. An "inside-out" design is used as compared to a conventional motor/generator design. The rotating portion, i.e., the rotor, is on the outside of the machine. The stationary portion, i.e., the stator, is formed by the inside of the machine. The rotor contains an array of permanent magnets that provide a uniform field. The windings of the motor are placed in or on the stator. The stator windings are then "switched" or "commutated" to provide a DC motor/generator much the same as in a conventional DC motor. The commutation can be performed by mechanical means using brushes or by electronic means using switching circuits. The invention is useful in electric vehicles and adjustable speed DC drives.

The suspension system of the Maglev vehicle has nonlinear and hysteresis characters. The equilibrium point of the maglev system is unstable. It is very difficult to control the suspension system with fine dynamic and static characteristics. PID controllers can be used to regulate flow, temperature, pressure, level, and many other industrial process variables.

Sensors and actuators are the critical system components that collect and act on information in the analog environment and link them to the world of digital electronics. The functional groups of sensors, software, controller hardware, and actuators form the backbone of present and future automotive systems. Unit volumes for sensors and actuators in the automotive industry are measured in millions per year and at a unit cost of a few dollars. The design of sensors and actuators has increasingly made use of microelectromechanical systems (MEMS) technology.

Electromagnetic suspension is a method by which an object is suspended with no support other than magnetic fields. Magnetic force is used to counteract the effects of the gravitational acceleration and any other accelerations. The two primary issues involved in magnetic levitation are lifting forces: providing an upward force sufficient to counteract gravity, and stability: ensuring that the system does not spontaneously slide or flip into a configuration where the lift is neutralized.

In the industrial domain, magnetic levitation has been successfully implemented for many applications. We can mention, for example, high-speed train suspension in Japan and Germany, vibration isolation systems, magnetic bearings, rocket-guiding projects, and superconductor rotor suspension of gyroscopes.

The three primary functions in maglev technology are levitation, propulsion, and guidance.

Project Implementation Method

1. Hardware setup of electromagnetically suspended Electric Vehicle (EV) in free space.
2. MEMS sensor for balancing and measuring the kinematics of the EV.
3. Propulsion mechanism for movement of EV in a given direction
4. Android application for controlling the motions and features of EV.
5. Bluetooth communication between the processor and android application through serial communication.
6. MPU6050 MEMS sensor will communicate with processor ATMega328p by utilizing the I2C communication protocol.
7. Fast rotating BLDC motors patched together with strong neodymium magnets to create strong rotating flux in order to generate the required Lorentz force.

Benefits of the Project

1. transportation engineering (magnetically levitated
   trains, flying cars, or personal rapid transit (PRT),
   etc.),
    
2. environmental engineering (small and huge wind turbines: at home, office, industry, etc.),
   aerospace engineering (spacecraft, rocket, etc.),
    
3. military weapons engineering (rocket, gun, etc.),
    
4. nuclear engineering (the centrifuge of a nuclear reactor),
   
    
5. civil engineering including building facilities and air
   conditioning systems (magnetic bearing, elevator, lift,
   fan, compressor, chiller, pump, gas pump, geothermal
   heat pumps, etc.),
   
    
6.  biomedical engineering (heart pump, etc.),
    
7.  chemical engineering (analyzing foods and beverages,
   etc.),
   
    
8. electrical engineering (magnet, etc.),
    
9. architectural engineering and interior design engineering including household and administrative appliances (lamp, chair, sofa, bed, washing machine,
   room, toys (train, levitating spacemen over the space
   ship, etc.), stationery (pen), etc.),
   
    
10. automotive engineering (car, etc.),
     
11.  advertising engineering (levitating everything considered inside, or above various frames can be selected).

Technical Details of Final Deliverable

• A BLDC motor with a 3500Kv rating will be used in the project.
• 3500Kv means 3500rpm per volt.
• 4 (14.8v) lipo battery will be used.
• 3500 × 14.8=51800

Motor = 51800 rpm

• The magnetic field for rotating magnet/coil is defined as:

ØB = AB cos(wt)

 Angular velocity w = 2?T

• Rate of change of flux:

?ØB?t= -AB w×sinwt

• According to Faraday’s Law, emf induced will be:

                              

• EMF =  -?ØB?t= AB w×sinwt   (v) --------------------(1)

Finding T period:

RPM                Seconds

51800              60

        1               X                                                                                            

X = 6051800=1.158×10-3sec

T = 1.158×10-3

w = 2?T= 2?1.158×10-3  = 5424.5

w = 5424.5 rad/sec

• putting value of w in equation (1)

          EMF = AB ×  (5424.5) × sin (5424.5 ×  t)               (2)

• The area under the influence of the rotating magnetic field:

A=?r2

A=? 0.052

                                                     A=7.85 ×  10-3  m2

• Putting value of (A) in eq 2

EMF = 7.85×103B5424.5 sin?(5424 .5 (t))

EMF = 42.58B5424.5 sin?(5424 .5 (t))               (3)

• Considering EMF Produced for 8 secs only

EMF = (42.58) (B)(0.91)

EMF = 38.75(B)                (4)

• EMF = Ieddy current× R     <

Final Deliverable of the Project HW/SW integrated systemCore Industry TransportationOther Industries Manufacturing Core Technology Clean TechOther Technologies OthersSustainable Development Goals Affordable and Clean EnergyRequired Resources

Item Name	Type	No. of Units	Per Unit Cost (in Rs)	Total (in Rs)
			Total in (Rs)	59100
BLDC Motors	Equipment	5	5000	25000
NEODMIUM Magnets	Equipment	20	500	10000
Processor	Equipment	1	800	800
Propulsion equipment	Equipment	1	1500	1500
MEMS Sensors	Equipment	1	1200	1200
Bluetooth	Equipment	1	750	750
Power Electronics module	Equipment	1	2500	2500
Aluminum sheet track	Equipment	1	8000	8000
LIPO battery	Equipment	1	7500	7500
wires	Miscellaneous	1	850	850
stationery	Miscellaneous	1	1000	1000