Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
  • B60L5/00—Current collectors for power supply lines of electrically-propelled vehicles
  • B60L5/005—Current collectors for power supply lines of electrically-propelled vehicles without mechanical contact between the collector and the power supply line
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
  • B60L2200/00—Type of vehicles
  • B60L2200/26—Rail vehicles

Definitions

• the present invention relates to a method and a device for supplying electric power to a motor vehicle from an electrical line. It finds a particularly interesting application in the field of electric motor vehicles whose power supply is through a power line or catenary such as electric trains and other means of urban and interurban transport. In particular, it applies advantageously to all electric trains traveling at very high speed. However, the invention is of a broader scope because it can be applied to any high current power supply system.
• the catch current is commonly associated with an articulated mechanical device said pantograph responsible for r establish and maintain electrical contact in order to provide power to the motor of the train and all ancillaries thereof.
• the quality of the contact is strongly dependent on the mechanical qualities of the pantograph and the electrical and mechanical qualities of the catenary used. It is in all cases subject to frictional forces.
• the quality of contact becomes problematic at high speed of movement of the train, as in high-speed trains. Indeed, it is recognized that one of the problems that we are confronted with in high speed trains is the maintenance of a good electrical contact between the catenary line and the pantograph of the train. For example, tests to beat the speed records require a particular adjustment of the voltage of the conductor wire forming the power line.
• the present invention therefore aims to improve the quality of the electrical contact between the catenary line and the pantograph of a train or between any other electrical current capture system.
• Another object of the invention is to solve the problem of wear of the power line and the pantograph due to the friction forces.
• At least one of the aforementioned objects is achieved with a method for supplying an electric motor vehicle with electric power from an electrical line.
• the vehicle comprises at least one electric current collector connected directly or via a power distribution system to the motor.
• This collector has a potential difference with the power line.
• a feral plasma is created by means of a high power pulsed femtosecond laser, a conductive plasma between the collector and the power line, the potential difference being sufficient for the plasma to trigger and guide an electric discharge. .
• the electrical power delivered by a voltage or catenary line is transported to an electrical contact, the collector, located in the fixed or moving vehicle and connected to to the electric motor of the vehicle.
• the collector located in the fixed or moving vehicle and connected to to the electric motor of the vehicle.
• Plasma provides a good quality of the electrical contact between the power line and the collector, even at high speed and any changes in distances between the collector and the power line.
• one end of the collector can be placed a few centimeters from the power line.
• the distance between the power line and the collector does not require critical adjustment, as the process of forming a laser-guided, guided, electrical discharge occurs over several centimeters or even several meters.
• the method can therefore be applied for a wide speed range of the vehicle.
• the process of forming an ionized region of the air greater than the Rayleigh distance of the laser beam is generally described in the scientific literature as femtosecond filamentation.
• a high power laser pulse is able to ionize the molecules of the atmosphere.
• the technology of short-pulse lasers makes it possible to reach the necessary powers for the ionization of the air with very modest pulse energies, much lower than the joule.
• These lasers have a duration of the pulse less than one picosecond, or 10 ⁇ 12 seconds and can reach an instantaneous power greater than 10 GW, or 10 7 watts.
• infrared pulses of a few millijoules of energy focused in the air with the aid of a single lens, are sufficient to create a conductive plasma over distances of several centimeters around the focus of the lens.
• the laser pulses came from a femtosecond laser with titanium-doped sapphire as active medium.
• the physical process leading to ionization of air over a large length is well identified, it is a competition between autofocusing of the laser beam and multiphoton ionization involving the simultaneous absorption of a large number of infrared photons.
• the plasma created by femtosecond filamentation makes it possible to temporarily short-circuit a device constituted by two electrodes subjected to an electric field of a few kV / cm.
• the power line is under high voltage and the potential difference is preferably greater than 10kV, for example between 10 and 25 kV.
• the laser operates at a high repetition rate, for example greater than the kilohertz, so as to regenerate the plasma and thus maintain a good flow of electric current.
• the power of the pulses provided by the laser is preferably greater than the millijoule.
• said vehicle is a train and the collector is an associated pantograph.
• a device for supplying an electric motor vehicle with electric current from an electrical line said vehicle comprising at least one electric current collector connected to the motor and having a potential difference with the electric line.
• the device comprises a femtosecond laser pulsed at high power to create, by femtosecond filamentation, a conductive plasma between said collector and said power line, the potential difference being sufficient for an electric discharge to be triggered and guided by plasma.
• the only figure illustrates a train 1 moving on rails.
• the motor 2 of the train 1 is supplied with electric current by a pantograph 3 whose free end 4, above the train, is disposed close to a catenary 5.
• the latter is a high voltage power line, typically 25kV.
• the train also comprises a femtosecond laser 6 providing high power pulses which are focused in the air in the vicinity of the catenary 5 and the end 4 of the pantograph 3.
• the focusing is carried out by means of a lens 7.
• the Filamentary beam forms a plasma column 8 connecting the catenary to the pantograph 3 by its end 4.
• the current flowing through the plasma is conducted by the pantograph to the electric motor 2.
• the laser 6 operates at a high repetition rate, which makes it possible to regenerate the plasma and to avoid power failures.
• This femtosecond laser operates at rates higher than the kilohertz with energies per pulse exceeding the millijoule.
• the device according to the invention can be multiplied in several copies on the same train to increase the total current and to prevent inadvertent interruption of the passage of electric current.
• the invention is not limited to the examples that have just been described and many adjustments can be made to these examples without departing from the scope of the invention.
• the present invention can be applied to all systems responsible for conducting an electric current from a power line to an electric motor, whether it is moving or not.

Landscapes

• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Transportation (AREA)
• Mechanical Engineering (AREA)
• Current-Collector Devices For Electrically Propelled Vehicles (AREA)

Applications Claiming Priority (2)

Publications (1)

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• 2004
  • 2004-09-08 FR FR0409485A patent/FR2874864B1/fr not_active Expired - Fee Related
• 2005
  • 2005-09-08 US US11/661,981 patent/US7854304B2/en not_active Expired - Fee Related
  • 2005-09-08 CA CA002579376A patent/CA2579376A1/fr not_active Abandoned
  • 2005-09-08 EP EP05805603A patent/EP1799488A1/de not_active Withdrawn
  • 2005-09-08 JP JP2007529381A patent/JP4803503B2/ja not_active Expired - Fee Related
  • 2005-09-08 WO PCT/FR2005/002242 patent/WO2006027503A1/fr active Application Filing

Non-Patent Citations (1)

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