System and method for generating electric powerDocument Transcript
IFET COLLEGE OF ENGINEERING GANGARAMPALYAM SYSTEM AND METHOD FOR GENERATING ELECTRIC POWER FROM MOVEMENT OF THE RAILPREPARED BYS.SHALENEE A.RAJESHWARIEEE-2ndYEAR EEE -2ndYEAR C.PUNITHA EEE-2ndYEAR
ABSTRACT: The electrical power generation system is configured to generate electric power via movementsof the rail. An electrical power generation system comprises a variable capacitor and a power source.The power source is used in the form of a generator to prime the variable capacitor that effectivelymultiplies the priming energy of the power source by extracting energy from the passing vehicle. Byalternately priming the variable capacitor using charge from the power source and discharging it at alater time in a cyclic manner to change the capacitance, a significantly large amount of electrical energyis produced due to change in capacitance.1. INTRODUCTIONThe proposed technique relates generally to BLOCK DIAGRAM:generating electricity and, more particularly, to amethod and a system for generating electricityalong a railroad track. Many known railroad DRIVE FIRST CAPACITOR PLATE TOWARDSsystems employ a variety of wayside equipment SECOND CAPACITOR PLATE IN RESPONSEalongside the railroad tracks. Within a network, TO VEHICLE ON THE ROADrailroad tracks often span rural and unpopulatedareas, and as such, providing power to waysideequipment in remote locations may be achallenging and costly task. At least some CHARGE FIRST AND SECOND CAPACITORknown railroad systems run power lines into PLATE IN RESPONSE VIA A POWER SOURCEremote areas to power wayside equipment.However, depending on the location, such powersystems may be expensive to install and tomaintain. Unfortunately, traditional automated BIAS THE FIRST AND SECOND CAPACITORdevices generally obtain operating power from PLATES APART FROM ONE ANOTHER WHENan external power source, which is not generally THERE IS NO PRESSURE OF VEHICLE ON RAILavailable in remote areas. That is, the automateddevice receives operating power that isgenerated at a remote location and that isdelivered over a power grid, and coupling the INCREASE IN ELECTRICAL POTENTIALgrid to the device can be a costly proposition, BETWEEN FIRST AND SECOND CAPACITORespecially in remote areas. In certain instance, PLATESlocal power sources, such as batteries, have beenemployed. In any event, even if a local orexternal power source is provided, these powersources may not provide a cost effectivemechanism for producing sufficient levels ofpower for operation of the automated testingdevices. Therefore, there is need for a systemand method for improving electric powergeneration with respect to rail systems.
2. BACKGROUND The technique provides an electric one another, thereby displacing the plates withpower co-generation system for use with a respect to one another. This displacementrailroad network. The system includes a power changes the electrical capacitance between thesource, such as a power generation device or an first and second plates and, resultantly, increasesexternal power source. The power co-generation the electric potential between the first andsystem includes first and second electrical second plates. In turn, this displacement of thecapacitance portions that are electrically coupled first and second plates facilitates the co-to the power source and that are configured to generation of electrical energy from the kineticcarry positive and negative charges, and potential energy of the vehicle on the rail.respectively. The power co-generation systemfurther includes a biasing device that is 3. DETAILED DESCRIPTION:configured to separate the first and secondcapacitance portions with respect to one another. FIG. 1 illustrates railway monitoring system.Thus, by varying the distance between the The railway monitoring system includes acapacitance portions in response to a vehicle on railway track that has a left rail, a right rail and athe rail, the capacitance portions cooperate to act plurality of ties extending between and generallyas a variable capacitor that facilitates the co- transverse to these rails. The ties are coupled togeneration of power with respect to the system. the rails and provide lateral support to the rails,That is to say, the mechanical energy of the which are configured to carry vehicles, such asbiasing device is converted into electrical energy trains, testing vehicles or the like. The systemfor the system. also includes a power tie that has hollowedIn accordance with above technique, a method regions that provide locations inside of whichof co-generating power via a vehicle traveling various components are disposed. Although theon a rail is provided. The method includes the figure shows a single power tie, railroadact of driving first and second capacitor plates networks including any number of power tieswith respect to one another in response to the and power ties in electrical communication withvehicle that is traveling on the rail. The method one another are envisaged. The power tie is usedalso includes the act of charging the first and to power sensors, signaling devices or anysecond capacitor plates via a power source, such number of suitable electrical devices.as a power generation device or an external 3.1. POWER TIE:power source. The method further includes The power tie includes a power source,biasing the first and second plates apart from such as the power generation device, a sensing
device, a processor, and communicationcircuitry, all of which are disposed within thehollowed regions of the power tie. With respect 3.2. REMOTE MONITORING CENTREto the power generation device, it is worth In the railway monitoring system, thenoting that exemplary power generation device communication circuitry is configured to receiveenvisages external power sources, a host of local data signals output from the processor and/or thepower generation device or a combination sensing device and to transmit the data signals tothereof, among other types of power devices. A a remote monitoring center. The communicationpower co-generation device, as discussed below, circuitry comprises hardware and/or softwarecooperates with the power source (e.g. power that facilitates the communication circuitry togeneration device) to generate power. By communicate the data signals to the remotedisposing these components in the power tie, the monitoring center. The communication circuitrypower tie acts as a housing that protects and is configured to communicate the data signals tofacilitates the installation of various components the remote monitoring center in accordanceof the tie. The power tie includes conditioning with a given communication protocol, such as acircuitry that is configured to rectify and/or cellular protocol, a wireless protocol, a radioconvert the power output from the power frequency protocol, or a combination thereof.generation device to a desired output power that The remote monitoring center includes ais appropriate to the electrical components processor, user interface, and communicationlocated downstream of the power generation circuitry. To facilitate communications withdevice. The sensing device is coupled to the field technicians, the remote monitoring centerprocessor, which includes hardware circuitry and the power tie are configured to communicateand/or software that facilitates the processing of with a field unit which, by way of example, is asignals from the sensing device. As will be laptop computer. Again, the communicationappreciated by those skilled in the art, the circuitry receives data signals output from theprocessor includes a range of circuitry types, processor or the sensing device and transmitssuch as a microprocessor, a programmable logic these data signals to the field unit via a wiredcontroller, a logic module, etc. Additionally, connection port or a short range wireless linkthose of ordinary skill in the art will appreciate such as infrared protocol, Bluetooth protocol,that the sensing device encompasses any number wireless local area network or the like.Toof devices including weight sensors, temperature communicate with the power tie, the remotesensors, or the like. monitoring center, as well as the field unit, each
includes communication circuitry and user other plate develops a negative charge. Theinterfaces. Advantageously, the user interfaces greater the difference of electrons on opposingfacilitate inputs from a user and provides plates of a capacitor, more flux is generated andmechanism through which a user can manipulate the capacitor is able to store more electricaldata and sensed properties from the components energy. Specifically, the voltage across theof the power tie. capacitor (i.e. between the plates) is increased.3.3. VARIABLE CAPACITOR: The capacitance of the capacitor is dependent on The power co-generation device the area of the plates, distance between theincludes a variable capacitor. The variable plates, and ability of dielectric material tocapacitor has two capacitance portions, such as support electrostatic forces, as discussed furtherconductive plates that are each coated with a below. Because, each plate stores equal butthin film of dielectric material. The two mutually opposite charge, the total charge in theelectrically conductive plates are held mutually capacitor is zero. In the illustrated embodiment,apart in an open position via a biasing member, an analog signal line between the co-generationsuch as a compression spring. The plates are device and the sensing device carries an analogelectrically coupled to the power source, such as signal indicative of the load on the rails. Thethe illustrated power generation device, and each operation of the variable capacitor is discussedplate carries opposite charges with respect to in two levels as discussed below:one another. The variable capacitor facilitates 4.1. Open positionchanges in the distance between the two platescausing electrical power generation from thischanging distance. To facilitate electrical isolation of thetwo capacitance plates a dielectric film isprovided on one plate or on both of the plates.The dielectric film acts as an insulator betweenthe conductive plates and impedes the flow ofcurrent between the capacitor plates. In oneexemplary embodiment, the dielectric filmincludes polyimide material, such as a kaptonhaving functionally linked polymers. Thedielectric film includes aluminum oxide havingpolar metal oxide bonds possessing largepermanent dipole moment. The dielectric film The above figure illustrates variablemay include polymers, ceramics, or the like. capacitor in an open position. The plates are3.4. POWER SOURCE: biased apart and held in this open position by a The power source is coupled to the biasing member, such as a compression spring.conductive plate. The power source may be The plates are separated by a larger gap "d" inlocated locally within the power tie or external the open position, and the open positionto the power tie. The power source is coupled to corresponds to a situation when there is nothe conductive plate via the power conditioning vehicle above the rails. The capacitance of thecircuitry and a power isolation device. The capacitor is directly proportional to thepower isolation device is a switch or a diode. electrostatic force field between the plates, and4. OPERATION: the capacitance of the capacitor is calculated in When DC voltage is applied across the accordance with the following relationship:two plates of the variable capacitor, aconcentrated field flux is created between theplates and electrons are liberated from thepositive conducting plate and deposited on the Where C is the capacitance in farads, ε is thenegative conducting plate. Thus, one of the permittivity of the dielectric, A is the area of theplates develops a positive charge, while the
plate in square meters, and "d" is the distance position in farads, Vc is the voltage across thebetween the plates in meters. From the above plates in closed position, and Vo is the voltagementioned relationship, it can be seen that the across the plates in the open position.capacitance of the capacitor is reduced in the Consider, let dielectric permittivityopen position, because the capacitance is k=2.5, ε0=8.55 picofarads/m, ε=kε0=2.2×10-11inversely proportional to the distance or gap "d" farads/m, A=0.1 m , t=1 micron (10-6 m) is the 2between the capacitor plates. thickness of the dielectric layer, d=1 mm (10-3 m) is the space between the plates.4.2. Closed position Thus, when the exemplary variable capacitor is in the closed position, the capacitor has a capacitance value of 2.2 microfarads, and the distance between the plates is defined by the The above figure illustrates variable thickness of the dielectric material. When thecapacitor held in a closed position. When a distance between the plates is increased, thevehicle is above the rails, the plates are biased capacitance of the variable capacitor is changedtowards each other, thus reducing the gap "d". to:This reduction in the gap "d" changes thedistance between the plates and also changes thecapacitance characteristics of the variablecapacitor. From the above mentionedrelationship, it can be seen that the capacitanceof the capacitor in the closed position is Where d>>t. In this system, the electricalincreased due to the reduced gap "d" between potential across the plates is inverselythe capacitor plates. Indeed, in the closed proportional to the capacitance of the device andposition, the value of "d" is effectively the is:thickness of the dielectric film, and thisthickness is significantly smaller than the valueof "d" in the open position. Thus, decreasing thecapacitance of the capacitor. where Vo is the voltage or electric potential5. ANALYSIS: across the plates when the plates are in the open position and Vc is the electric potential across (i) The capacitance of the capacitor is the plates when the plates are in the closedcalculated in accordance with the relationship: position. 6. RESULTS: (1) Increasing the electrical potential of the (ii)Voltage across the plates in open variable capacitor also increases the electricalposition is calculated as: energy of the system, as the mechanical energy of separating the plates is converted into electrical energy. Thus, in the above example, (2) the electrical energy of the capacitor is increasedWhere Cc is the capacitance in the closed by 2400 times. The power generation deviceposition in farads, Co is the capacitance in open effectively primes the variable capacitor, and the
energy of this priming is multiplied by varying neat and clean, the system is only proposed andthe distance between the capacitor plates. By is yet to be designed experimentally .alternately priming the variable capacitor usingpower from the power source and discharging itat a later time in a cyclic manner to change thecapacitance, a significantly large amount ofelectrical energy is produced due to change incapacitance in comparison to the electricalenergy and power from the power source itself.A number of such systems are connectedtogether for greater energy delivery. Thepotential developed for various distance are asfollows:6. Tabulation for various capacitance Thickness Capacitance Potential V0 -6 of the (10 f) dielectric layer (m) 10-3 0.0009 2444.44 -4 10 0.02 244.44 10-5 0.2 24.444 10-6 2.2 17. ADVANTAGES AND APPLICATIONS: Advantageously, communicationbetween the power ties facilitates sharing ofresources and also facilitates the development ofcertain data types, such as block occupancydetection, distance to train, detection of brokenrail, or the like Additionally, by monitoring variousproperties of the variable capacitor, certainproperties regarding the vehicle passing on therail can be determined. For example,determining the time, the capacitor is in theclosed position or the open position provides anindication of the speed of the vehicle.8. CONCLUSION:Thus the property of variable capacitance is usedto trap energy (kinetic and potential) of thevehicle movement in the rail. By alternatelypriming the variable capacitor using the chargefrom the power source and discharging it at alater time in a cyclic manner to change thecapacitance, a significantly large amount ofelectrical energy is produced due to change incapacitance. Though the theory appears to be