2.9 EFFECTS IN LIM 2.9.1 END EFFECT One obvious difference between LIM and conventional rotary machines is that the fact that LIM has ends. This means that the travelling magnetic field cannot join up on itself, and introduces end effects. The end effects can result in characteristics that are much different from rotary machines. The end effect is clearly exhibited in the form of a non-uniform flux density distribution along the length of the motor .For a LIM supplied with a constant current, typical variation of the normal flux density with slip and position along the length is illustrated in Fig. With constant primary current, its magnetizing component and consequently the air gap flux decreases as the load component increases with increasing …show more content…
This effect is more evident with lower values of width-to-air gap ratio. Fig. illustrates the variation of the normal flux density in the transverse direction. The figure shows a dip at the center due to the edge effect, and the dip is more obvious at higher slips. As a result, the edge effect will increase the secondary resistivity, lateral instability due to the uneven secondary overhangs and a reduction in performance. 2.9.3 GAP EFFECT Conventional rotary machine has a very small air gap, in the order of 2mm or less. This allows a high gap flux density. For LIM, the air gap can be as large as 5cm for one operating on a traction system. The magnetic circuit reluctance is much higher for large air gaps, in which the magnetizing current is also higher. There is a rather large leakage flux that further reduces the operating power factor . The gap density is less than for the rotary counterpart, and consequently iron losses form a smaller part of the total …show more content…
The trains themselves are less costly and noisy than conventional trains and they require less maintenance due to their levitation eliminating most of the friction. Maglev trains use far less energy than conventional trains and emit no pollutants. High speeds allow for maglev trains to be a realistic alternative to flying, and they can help reduce air and road congestion as more people are moving around the world. So far LIM has been controlled with few classic controllers , in future various latest control methodologies are upcoming which will have effective control of LIM in terms of the efficiency and performance of the machine. The U.S. Navy plans to start launching future naval fixed aircraft using linear induction motor. The scientists are changing the shape of stator to flat, and the vehicle is to used in place of the rotor. This vehicle will move in straight line and will achieve high acceleration quickly. 4.6 REFERANCE: [1] Theory and performance of Electrical Machines- J.B.Gupta / Published by S Kataria & Sons [2] A course in Electrical Machine design by A.K SAWHNEY/ Published
The Wankel rotary engine named after the designer, Felix Wankel, was engineered in the early 1930’s. The rotary engine was unlike the conventional four stroke internal combustion engines and lacked the need for pistons, valves and camshafts. With only three moving parts involved in the design, this engine showed great promise in reliability and efficiency. The first Wankel rotary model was shown in 1960, not as an engine, but as a pump drive. Instead of the very complicated system involved in a conventional reciprocating piston engine, the wankel engine incorporated triangular “rotors” (see figure 1) that rotate within an epitrochoidal chamber around an eccentric shaft. Not only is this engine much more simple (only 3 moving parts rather
The strategy behind the high-speed railway system would be to relieve highway congestion, air traffic congestion, and help reduce the necessity of expansion of highways and air systems (which is limited due to the inability to build new air space). Also, with this type of system (this system works on magnetic levitation), you would have a significant reduction in air pollution that would result as high-speed captures a large portion of the intercity travel market from automobiles and airlines.
A maglev system is nonlinear and its open-loop response is unstable because of the nature of the magnetic forces used. PI controllers are based on a linearized model, so they do not compensate for certain variations. These variations can occur when a magnetic bearing experiences a working load change on the rotor during operation, ...
In a DC motor, the armature consists of any number of windings, each one an electromagnet. The armature is immersed in a directional external magnetic field. This external field does not move, and can come from permanent magnets or electromagnets.
UIC 2008, High Speed Rail: Fast Track to Sustainable Mobility, UIC, Paris, viewed 3 May 2011, < http://www.uic.org/IMG/pdf/20101124_uic_brochure_high_speed.pdf>.
The History of Magnets and Electromagents Magnets and electromagnets have many uses, every electric motor,
The force of gravity is an internal force and any work done by it doesn’t change the total mechanical energy of the train of the cars. The normal force of the track pushing up on the cars is an external force. Air resistance is capable of doing work upon the cars and drains a small amount of energy from the total mechanical energy which the cars possess. However, due to the complexity of this force and its small contribution to the large quantity of energy possessed by the cars it is often neglected, and by neglecting the influence of air resistance, it can be said that the total mechanical energy of the train of the cars is conserved during the ride. That is to say, the total amount of mechanical energy possessed by the cars is the same throughout the ride, and energy is neither gained or lost, it’s only transformed from kinetic energy to potential
According to James Trefil (2015), the author of Electric Motor, “Anyos Jedlik (1800–1895) used one coil of wire on a rotating rotor and another coil as a stator, analogous to a rotor except that it stays put.” This is how use their idea to created a motor.
Energy efficient motors use more copper and iron than regular motors. They also consume less energy than regular motors.
Keep cords and cables in one place with our Hollow Servo Motor, which is designed with a flange-mount hollow bore. It allows for media – power cables, pipes and hoses – to pass through the motor. The motor produces powerful torque and high stiffness with a low total weight, making it well suited for applications where the motor is also moving. It is ideal for industrial robots, machinery, machine tools, automatic assembly machines, converting and printing, handling equipment, and laser machine
BETWEEN various types of monorail systems, control systems monorail occupies a very important role: ensuring the safe and secure operation of the train. Railway companies today are faced with many issues by increasing the use of old kinder in population, increasingly diverse needs of the public to look after aging is increasing among young or old, in addition to the current business environment, train hard and train control systems are also faced with a daunting challenge:
The torque developed by the motor is proportional to the product of the armature of the current and air gap flux i.e.
The disadvantage of this motor is the need of electronic driver to comutate the motor and make the bldc motor system become expensive. Nevertheless, if efficiency is essential then the bldc motor system is inexpensive considering many advantage which can be gotten. This is the reason why many EV (electric vehicle) developer use BLDC motor as the propulsion
Furthermore, the high-speed rail network could mean twenty-nine million fewer car trips and 500,000 fewer plane flights annually, according to a 2006 study ...
Rail transportation is a transportation in which for movement of people and goods which from one location to another destination. Rail had been takes the important role in physical and economic development of town and cities in a country and it was developed over the world. Rail transport can be made a property value in a country increase and it must be needs improvement in transportation network expanding (Goldberg, 1970). Thus, the railway services need to be done with continuous improvement and it is important to the rail passengers of the range and quality of facilities and service on stations and trains (Gleave, S. D., 2000). The future development to a public transportation is a key to affect