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
  • B60L5/18—Current collectors for power supply lines of electrically-propelled vehicles using bow-type collectors in contact with trolley wire
  • B60L5/22—Supporting means for the contact bow
  • B60L5/28—Devices for lifting and resetting the collector
• • 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 invention relates to a device for measuring the contact pressure between a contact wire and a pantograph of an electrically powered vehicle, in particular an electric rail vehicle, as defined in the preamble of claims 1 and 2.
• the determination of the contact force F resulting from the mechanical action of the pantograph and the overhead line system requires a device, who determines this contact force as close as possible to said contact point according to its magnitude and its point of application and from the measuring point, which is at high voltage level (e.g. 3 kV direct voltage; 15 kV or 25 kV alternating voltage), signals equivalent to contact force force to in-vehicle evaluation devices which are at counter potential. forwards.
• the term contact pressure F is to be understood as meaning that portion of the true contact force between contact wire and contact strip resulting from the mechanical action of the pantograph and the overhead line system.
• a generic device for determining the true contact force between a contact wire and a pantograph describes the US patent 5,115,405 A.
• a fiber-optic force sensor is attached to the contact strip, which is connected via fiber optics (and thus electrically isolated and largely independent of electrical and magnetic interference fields) to an in-vehicle device from which it is supplied with light and which receives its signal depending on the contact force .
• the force sensor consists of an optical fiber that is tensioned beneath the contact piece that is in contact with the contact wire and that is spring-loaded between the contact piece and its holder.
• a contact force acting on the contact strip leads to the deformation and micro-curvature of the clamped optical fiber, which consequently changes its light transmission properties.
• this device With this device, the exceeding of an upper and / or a lower threshold value of the true contact force between the contact strip and contact wire, which is caused, for example, by gusts of wind, is to be recognized and the contact pressure is to be corrected by means of an electronic-pneumatic command device and a pneumatic damping compensation actuator.
• This device appears to be suitable for detecting and signaling whether the contact force threshold values have been exceeded or not reached.
• this arrangement is completely unsuitable for effective contact force measurement within a certain force range, as is required for active control of the contact pressure or the true contact force of a pantograph, since the fiber-optic force sensor has a very low signal / noise ratio and is sufficient exact continuous measurement determination is not possible.
• This sensor does not allow determining the point of application of the contact pressure on the contact strip.
• the arrangement since it extends over the entire length of the contact strip, has a not inconsiderable spatial expansion and mass, which can adversely affect the vibrational and aerodynamic behavior of the pantograph.
• Technical training appears to be too sensitive to such loads as are unavoidable when installing, maintaining and transporting a pantograph. Since the temperature dependence of the light transmission properties changes with the degree of mechanical stress on an optical fiber, effective compensation of this temperature dependence can hardly be achieved.
• the constantly changing mechanical loads and deformations to which the optical fiber of this force sensor is subjected limit the service life of this fiber-optic sensor and therefore do not guarantee operational reliability of the device.
• Patent specification EP 0 697 304 A2 discloses a device for measuring the contact pressure for an actively regulated pantograph, in which an analog measuring load sensor is provided below a support insulator carrying the pantograph head, which is arranged on a vertically extendable structure, or associated with the contact strip, which must cooperate with other length measuring sensors in order to influence the action of two separately operating vertical stroke drives via a control unit.
• This load receiver should also be able to be constructed using optical waveguides without further details being given about their structure, arrangement and effect. At least with the arrangement of the load receiver below the support insulator, considerable difficulties arise with regard to determining the amount of the contact pressure, since wind and mass forces acting between the contact point and the measuring point influence the measurement result.
• the size of the load sensor apparent from the drawings makes it impossible to arrange it near the contact strip, since this would adversely affect the vibration-related and aerodynamic behavior of the current collector. With this load receiver, it is not possible to determine the point of application of the contact pressure on the contact strip.
• This sensor has an inner tube and an outer tube coaxial therewith, which is divided in the longitudinal direction of the tube and forms two non-touching half-shells.
• An optical fiber is embedded in a helical shape between the inner tube and the outer tube shells in an elastic mass and undergoes a reversible bend in a certain bending radius range when the sensor is subjected to a mechanical pressure load on one side, in which the two outer tube half shells are moved towards each other an optical signal passing through the glass fiber is measurably attenuated.
• a force sensor should be arranged on a suspension strut carrying a contact strip and an acceleration sensor on the rocker of a half-scissor pantograph carrying two parallel contact strips. Both sensor signals are fed to the inputs of a control device, which controls special torsion actuators, which are arranged around the axis between the forearm and the upper arms of the pantograph scissors and, in addition to the usual lifting device of the pantograph, set the contact pressure of the contact strips on the contact wire.
• the contact pressure of the contact strip on the contact wire is determined by measuring the distance from the deflection of the shock absorber or that a force sensor measures the force transmitted by the shock absorber.
• a disadvantage is the relatively large distance between the sensors and the actual contact point between contact wire and contact strip, since mass and wind forces acting between the contact point and the respective sensor influence the measurement results and can have a falsifying effect on the control result.
• nothing can be found in this reference regarding the design and operating principle of the sensors.
• the object of the invention is to find a solution for a generic device which uses the advantages generally expected in the prior art for fiber-optic sensors with fiber-optic signal transmission for force measurement under high voltage and described for certain fiber-optic sensors while avoiding their disadvantages.
• the fiber-optic sensor of such a device should be arranged as close as possible to the actual contact point between the pantograph and the contact wire and be able to measure attacking forces between the components directly without large relative paths between them.
• the solution should allow such a shape, size, mass and arrangement of said measuring device with the fiber optic sensor that the vibration engineering and the aerodynamic behavior of the pantograph remains largely undisturbed.
• This device is intended to allow a determination of the contact pressure both according to its magnitude and according to its point of attack on the contact strip and to be able to generate and output contact force-equivalent signals or to generate and output contact force-changing commands which can be used for an actively regulated pantograph.
• the solution according to the invention makes it possible to determine the contact pressure both according to its amount (by summing the signals of the two fiber optic sensors carrying a contact strip or a contact strip) and according to their point of application (by comparing the signals from the individual forces of the two fiber optic carriers carrying a contact strip or contact strip) Sensors and arithmetical application of the leverage laws). Since it is known that contact pressure peaks occur regularly where the contact wire and catenary are suspended from the contact line masts, the knowledge of the changing point of application of the contact pressure can be used in a control algorithm to recognize the zigzag course of the contact wire and to recognize the contact line mast. To determine the repetition frequency as well as its first and second derivation and to use it to regulate the contact pressure in order to prevent the contact pressure peaks mentioned.
• a major advantage of the invention is that the devices according to the invention can be easily modified also for applications in other areas of technology in which forces, but also pressures and accelerations between components that are at high voltage potential are to be measured. Compared to previously common measurement methods with strain gauges and potentiometric measurement or with piezoelectric force transducers, a significant reduction in the effort for the measurement arrangement, the signal conversion, transmission and processing can be achieved.
• Another major advantage of the invention is that the components of the measuring device with the fiber optic sensor are designed and assembled so that they have the smallest possible dimensions and mass and can be integrated between the components of the pantograph in a force-transmitting manner.
• Another advantage is that the components of the measuring device required for the devices according to the invention are designed in such a way that they can be produced inexpensively and with reproducible properties.
• a next advantage of the inventive idea is that, for example, in the variant shown in the exemplary embodiment, only very slight changes in the structure of previously tried and tested pantograph types are necessary, so that inexpensive retrofitting of devices according to the invention can also be carried out on a large number of electric railcars in operation comes into consideration
• the contact force equivalent signals obtained with the devices designed according to the invention are also suitable for special measuring purposes with which, for example, the contact material of a pantograph can be checked or the condition of an overhead line and its catenary system can be assessed in a section of the route
• Fig. 1 is a view of the arrangement of an inventive
• a rail vehicle 2 on the roof side and isolated from the high-voltage potential of the contact wire 1 has a pantograph 3 in half-scissor design, which elastically guides a seesaw 4 at its upper end, which carries a pair of parallel contact strips 6 with its seesaw frame 5 and against the contact wire 1 leads
• the contact strips 6 consist essentially of a base body 7 and a contact piece 8 firmly attached to it, which keeps contact with the contact wire 1.
• a pantograph lifting drive is coupled, which, controlled by its control device 10, press the contact strip 6 against the contact wire 1 with a defined contact pressure should.
• the contact pressure that arises is not a stationary variable, but is subject to constant changes as a result of the vehicle speed, the wind intensity and direction, the stationary position of the catenary chain that guides the contact wire and its pantograph, friction and wind-induced vibrations, and the relative movement of the electric traction vehicle along its travel path .
• maintaining the contact pressure within the narrowest possible force range is essential for uninterrupted energy transfer to the electric motor vehicle and the least possible wear on the contact strip and contact wire and becomes more important and difficult with increasing vehicle speed and vehicle performance.
• An active control of the pantograph with the aim of a contact force curve within the narrowest possible tolerance band presupposes the most exact and continuous determination possible, the measuring location being as close as possible to the actual contact point between contact wire 1 and contact strip 8.
• one of the illustrated elastic deformation bodies 11 is installed near each of the two ends of the contact strip 6 between its base body 7 and the rocker frame 5.
• the resilient deformation body 11 should be arranged between the base body 7 and the contact piece 8.
• the force measured with such an arrangement comes much closer to the true contact force because the force components acting on the base body 7 as buoyancy or downforce from the air flow dependent on the wind and vehicle speed are also taken into account by the measuring arrangement.
• a fiber-optic reflex sensor 19 known per se is integrated in the resilient deformation body and with an associated one that is known per se
• Each resilient deformation sensor comprises a first partial body 12, which is rigidly connected to the rocker frame 5, a second partial body 13, which is rigidly connected to the base body 7 of the contact strip 6, and a spring arrangement 14 connecting the two partial bodies 12 and 13, which in the direction of the applied contact force F permits movement of the partial bodies 12 and 13 relative to one another.
• the spring arrangement 14 is designed so that this movement between the partial bodies 12 and 13 is free within the desired measuring range of the portion of the contact force F transmitted from the base body 7 to the rocker frame 5, which acts on the individual resilient deformation body.
• the fiber-optic reflex sensor 19 integrated into each resilient deformation body 11 by way of example essentially consists of two spatially separate parts: a first insert 20, which is screwed firmly into the first part body 12 of the resilient deformation body 11, contains two mutually parallel and defined-spaced light guides, of which the transmission light guide 22 guides a transmission light beam 24 emanating from the device 27 and allows it to emerge from its end face within a certain radiation angle. This light strikes the reflection surface 26 at a spatial distance a, which is carried by a second insert 21, which is fastened in the second partial body 13 of the resilient deformation body 11, and is reflected by the reflection surface 26 in the direction of the first insert 20.
• a partial luminous flux dependent on the distance a between the two inserts 20 and 21 can be caught by the receiving light guide 23 and can be fed as a receiving light beam 25 to the device 27 for sensor signal control and sensor signal processing.
• the fiber-optic reflex sensor 19 If the fiber-optic reflex sensor 19 is aligned within the resilient deformation body 11 in such a way that the reflection surface 26 extends orthogonally to the direction of the contact pressure F, the fiber-optic reflex sensor 19 detects the change in the reflected luminous flux, which is caused by a change in the distance a between the first use 20 and the reflecting surface 26 as a result of a change in the contact pressure F, so that the device 27 for sensor signal control and sensor signal processing after corresponding calibration from the change in the luminous flux difference between the transmitted light beam 24 and the received light beam 25 changes the distance a between the inserts 20 and 21 of the relevant one fiber-optic reflex sensor 19 recognizes and determines the attacking contact force F from the summation of the signals of both fiber-optic reflex sensors 19, which carry each
• the mutually parallel and defined spaced transmission and reception light guides 22 and 23 are expediently designed as optical fiber bundles, which can be simply separated from one another (as for example in FIG. 3), several times separated from one another or concentrically arranged around one another or guided in a statistically mixed fiber bundle .
• the fiber-optic reflex sensor 19 is aligned within the resilient deformation body 11 in such a way that the reflection surface 26 does not extend orthogonally, but parallel to the direction of the contact pressure force F, so that a deformation of the resilient deformation body 11 a lateral displacement of the reflection surface 26 at a constant distance a compared to the first insert 20.
• the reflection surface 26 should be arranged, for example, in such a way that its edge is displaced by the overlap region of the transmitted light beam 24 and the received light beam 25 shown in FIG. 3.
• the fiber-optic reflex sensor 19 thus detects the change in the reflected luminous flux, which is produced by a change in the reflecting portion of the reflection surface 26 as a result of a change in the contact force F.
• the arrangement shown in FIG. 2 with a double leaf spring has proven to be particularly advantageous for a spring arrangement 14, the leaf springs 15 and 16 of which are clamped and stressed together at one end by means of the first partial body 12 and are clamped and stressed together at the other end by means of the second part body 13
• Such a resilient deformation body is flexible on the one hand and has a relatively large, approximately linear spring travel and a high elasticity in the direction of the vertically acting contact force F to be measured, which means a high resolution with a steep signal level / contact force characteristic and a high signal / Noise ratio, with which interference signals from the connection points deformation body / component, from component natural vibrations and from frictional vibrations between contact wire and grinding piece can be effectively suppressed, can be achieved.
• the contact force F lie that is orthogonal to the measuring force directions a high stiffness and tilt stability against lateral and longitudinal forces, which attack, for example, with wind loads up to 1000 N in the horizontal plane on the contact strip, so that the contact strip is guided stably under all conditions
• the resilient deformation body 11 (for example, by using mechanically abrasive or electro-erosive wire processing or laser cutting) can be worked out in one piece with the first material 12, its second body 13 and the double leaf spring 15/16 with high accuracy and reproducible properties
• the two partial bodies 12 and 13 can be reduced in size and the resilient deformation body can be made even more space-saving and low-mass if the two inserts 20 and 21 of the fiber-optic reflex sensor 19 directly into the adjacent pantograph components (i.e. in FIGS. 5 and 7 or in FIG. 7) and 8) are installed (not shown)
• 11 specific stops 17 and 18 are in the resilient deformation body trained (Fig. 2).
• the resilient deformation body is provided with a shell which is sealed with respect to these environmental influences and is designed so that it moves of the two partial bodies 12 and 13 relative to one another and the action of the spring arrangement 14 is not hindered.
• This shell is preferably applied as an elastomeric skin, for example by casting or gluing.
• the invention is not limited to rail-bound electric traction vehicles and also not to half-scissor or scissor pantographs with and without rocker and with one or two contact strips of the type shown, but also applicable to current collectors with a completely different structure, for example of contact strips, contact strips, contact strip carriers and / or lifting drives .
• a measuring arrangement with a similar deformation body and fiber-optic reflex sensor can be used for the measurement of forces that act on the pantograph in the vehicle's longitudinal direction or of forces that act on the pantograph in the vehicle's transverse direction are, for example, tilted by 90 ° deformation body of the embodiment such that the leaf spring plane from the horizontal to a vertical plane is pivoted transversely to the vehicle and parallel to the contact strip or in a vertical plane along the vehicle and the deformation body of this position are attached accordingly. It is possible to combine two or three measuring arrangements, each measuring orthogonally to one another, in order to be able to determine completely as force vectors with regard to magnitude, point of attack and direction of attack.
• the application of the invention is not limited to the measurement of forces, but can easily be applied to the measurement of accelerations and pressures and can also be used in other areas of technology where such measurements are carried out on components at high voltage potential.

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• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Transportation (AREA)
• Mechanical Engineering (AREA)
• Current-Collector Devices For Electrically Propelled Vehicles (AREA)
• Force Measurement Appropriate To Specific Purposes (AREA)

Applications Claiming Priority (3)

Publications (1)

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• 1997
  • 1997-06-13 DE DE19725906A patent/DE19725906C1/de not_active Expired - Fee Related
• 1998
  • 1998-06-12 WO PCT/DE1998/001657 patent/WO1998056610A1/de not_active Application Discontinuation
  • 1998-06-12 US US09/445,757 patent/US6418397B1/en not_active Expired - Fee Related
  • 1998-06-12 RU RU2000100999/28A patent/RU2199725C2/ru not_active IP Right Cessation
  • 1998-06-12 CN CNB988060078A patent/CN1159175C/zh not_active Expired - Fee Related
  • 1998-06-12 JP JP50133299A patent/JP2002504997A/ja active Pending
  • 1998-06-12 EP EP98936201A patent/EP0988169A1/de not_active Withdrawn
  • 1998-06-12 KR KR1019997011751A patent/KR100333225B1/ko not_active IP Right Cessation

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