EP2277763B1 - Guarantee of a low-ohm electrical connection between wheels of a rail vehicle and rails - Google Patents

Abstract

The railway vehicle has an induction loop (1) for verification of low resistive electric connection between wheels (115a-115d,116a-116d) of the railway vehicle and running rails (101,102). A feeder is provided, which connects the electric alternating current voltage to the induction loop in an intermittent manner such that the induction loop is supplied with temporal interruptions with the alternating current. The duration of the temporal interruption of the supply is longer than the duration of the supply of the induction loop occurred before the interruption. An independent claim is also included for a method for operating a railway vehicle.

Description

The invention relates to a rail vehicle with an induction loop to ensure a low-resistance electrical connection between wheels of the rail vehicle and rails on which the wheels roll, by induction of electrical voltage in one of the wheels through sections of at least one of the rails and by electrical connections between wheels formed secondary current loop.

In some countries, the fact that a track section is occupied by a rail vehicle is detected (the so-called track busy message) by applying a voltage between both rails. When the track is not moving, this voltage remains due to the high resistance between the two rails and can be measured at the end of the track section. When driving through the track section by a vehicle, the applied voltage is short-circuited by the vehicle, so that the voltage collapses. This can be detected, so that a track occupancy message can be made.

A prerequisite for the safe operation of such a track occupancy message is that the electrical resistance between the rails and the wheels is sufficiently small. However, this resistance is dependent on the surface finish of both the rails and the wheels. In particular, by corrosion and dirt may be present on the rails and / or on the rolling surfaces of the wheels a no or only slightly electrically conductive surface layer. Despite such surface layers, the flow of current through the mechanical contact between the wheels and the tracks for the track busy message may be sufficient if the electrical voltage or current flowing through the contact point is sufficiently large. On the other hand, the situation arises, in particular on tracks with poor track conditions, that the contact resistance between the wheel and rail is so great that a sufficiently reliable function of the track occupancy reporting device is not ensured.

When operating rail vehicles with drive energy from electrical supply networks is often sufficient already an electrical base load (ie, for example, electrical supply of auxiliary operations in the rail vehicle from the electrical supply network) to the contact resistance between the wheel and rail overcome, so that the track occupancy message can be made safely. On the other hand, if no power is drawn from the electrical supply network and therefore no load current flows through the contact points between the wheels and the rails, the safe function of the track occupant avoidance is not guaranteed, especially in bad track conditions.

From the EP 0 500 757 B1 is a railway signaling system for detecting a train within a fixed track section known. The system includes a shunt auxiliary circuit including an inductive loop antenna provided on the railway vehicle so as to be inductively coupled closely to the rails. This induces a current into the wheel-and-track-axis circuit when the loop antenna is energized by an alternating source. The loop antenna is mounted in a bogie with two axes and is excited by an oscillator with a frequency of 165 kHz. The excitation frequency is tuned to the resonant frequency of the resonant circuit. The current induced by the loop antenna flows through a bogie / track loop formed by the two axles, the four wheels of the rail vehicle fixed to the axles, and a respective portion of the two rails between the wheels.

In addition to the ability to ensure the wheel-rail contact using an induction loop, the rail vehicle may also be equipped with pad brakes that contact the rolling surfaces of the wheels during braking, so that at least the wheel on its rolling surface a well-conditioned slightly roughened conductive Contact surface has. However, newer rail vehicles often have disc brakes. The installation of an additional block brake or similar grinding device leads to considerable additional effort. In addition, the wear on the brake and wheel requires more frequent maintenance.

A high-impedance resistor can also occur in particular when the rail vehicle is stationary, ie the wheels no longer roll on the rails. When a train with multiple cars is parked on a track, the likelihood that any of the plurality of axles still connect the rails with sufficient low resistance is relatively high. In addition, the axes act as parallel resistors, reducing the overall resistance between the rails. On the other hand, if, for example, a single rail vehicle is parked alone on a track, there is a risk that there will be no sufficiently low resistance without additional measures.

The in the EP 0 500 757 B1 described solution (see above) with an induction loop, which is supplied with alternating current, requires a power source that is sufficiently energized for long periods of time. In general, the vehicle battery is used to power the induction loop when the vehicle is disarmed, ie the pantograph is not in contact with the power grid. For non-electrically powered rail vehicles, eg locomotives with diesel-electric drive, when the drive is switched off also only the vehicle battery is available.

Since the determination of whether a vehicle is on a section of the route is a safety-relevant function, the induction loop must be able to be supplied with power for very long periods of time. In extreme cases, the rail vehicle can be parked for a long time in monitored track sections.

It is an object of the present invention to provide a rail vehicle and a method for operating a rail vehicle of the type mentioned, with which it can be safely ensured even when parked over long periods rail vehicle that the vehicle produces a low-resistance connection between the two rails. This maintenance should not be required to secure the function. Also, it should preferably be possible not to actively operate the vehicle (i.e., not to upgrade, for example, electrically powered rail vehicles), but to tow it off temporarily. After towing, the rail vehicle should be able to stand still again and still produce a low-resistance connection between the two rails and thus a busy signal is generated by a track occupancy reporting device.

According to one embodiment, an induction loop to ensure the low-impedance connection with stationary vehicle only intermittently (ie with time interruptions) fed with AC. This is based on the knowledge that a corrosion layer which has formed between the surfaces of the wheels and the rails in the contact area of the wheels and rails can already be broken by brief operation of the induction loop. Until the corrosion layer has formed again, a much longer period of time than is necessary for breaking through the corrosion layer. Therefore, the time duration of a supply interruption of the induction loop may be much longer than the duration of the feed before the interruption of the induction loop.

In particular, the duration of the feed can be shorter than 10%, z. B. shorter than 1%, the duration of the interruption of the feed of the induction loop, which takes place before the power supply. Furthermore, it is preferred to choose the duration of the supply of the induction loop with alternating current in the range of 0.5 to 10 ms, in particular 1 to 5 ms. The individual periods of supply can be different lengths or the same length. For example, Therefore, it is sufficient to feed the induction loop with alternating current every 1 to 5 s. The ratio of the duration of the feeds to the duration of the interruptions may therefore be even less than 1: 200 and up to 1: 1000 or less.

As above regarding the EP 0 500 757 B1 has been mentioned, the frequency of the supply of the induction loop with alternating current, for example 165 kHz. However, other frequencies can be selected or set. Preferably, however, a frequency of at least 20 kHz is set. The frequency does not have to be constant.

In particular, it proposes: A rail vehicle having a primary induction loop for ensuring a low-resistance electrical connection between wheels of the rail vehicle and rails on which the wheels roll, by induction of electrical voltage in one of the wheels, by sections of at least one of the rails and by electrical connections formed between wheels secondary Stromschlelfe, the rail vehicle having a feed device which intermittently applies an alternating electrical voltage to the induction loop, so that the induction loop is fed with time interruptions with alternating current.

Further, a method is proposed for operating a rail vehicle, wherein to ensure a low-resistance electrical connection between wheels of the rail vehicle and rails on which the wheels roll, an electrical voltage in through the wheels, through sections of at least one of the rails and by electrical connections between Wound secondary current loop is formed, wherein an alternating electrical voltage is applied intermittently to a primary induction loop for generating the induced voltage, so that the induction loop is fed with time interruptions with alternating current.

A significant advantage of the interrupted feeding of the induction loop is that less energy is consumed than with continuous feed. Therefore, a Rail vehicles are parked for longer periods and also be towed in the meantime without making contact with an external power supply.

• Die Induktionsschleife kann zwischen zwei Drehgestellen des Schienenfahrzeugs angeordnet sein. Insbesondere ist die Induktionsschleife dabei in der Regel unterflur eines Fahrzeugchassis des Schienenfahrzeugs. d.h. unterhalb des Bodens des Fahrzeugchassis angeordnet. Insbesondere können Leitungsabschnitte der Induktionsschleife, die sich etwa parallel zu den Gleisen erstrecken, mindestens 80 mm, z.B. mindestens 100 mm und vorzugsweise mindestens 150 mm oberhalb der Oberkante der Schienen angeordnet sein. Diese Leitungsabschnitte können in einer konkreten Ausführungsform höchstens 250 mm, z.B. höchstens 200 mm und vorzugsweise 150 mm über der Oberkante der Schienen verlaufen. Es sind die jeweiligen Vorschriften für die Einhaltung eines Freiraums zwischen der Schienenoberkante und Anbauten an dem Schienenfahrzeug einzuhalten.

The primary induction loop, which is fed with alternating current, can be carried out in different ways, eg as in the US Pat EP 0 500 757 B1 described. Alternatively or additionally, the induction loop may have the following features:

• The induction loop can be arranged between two bogies of the rail vehicle. In particular, the induction loop is usually underfloor of a vehicle chassis of the rail vehicle. ie arranged below the bottom of the vehicle chassis. In particular, line sections of the induction loop which extend approximately parallel to the tracks can be arranged at least 80 mm, for example at least 100 mm and preferably at least 150 mm above the upper edge of the rails. In a specific embodiment, these line sections may extend at most 250 mm, for example at most 200 mm and preferably 150 mm, above the upper edge of the rails. The respective regulations for the maintenance of a free space between the upper edge of the rail and attachments to the rail vehicle must be adhered to.

The secondary loop in which the stress is induced by induction does not necessarily have to be formed by two axles with mutually opposite wheels on the two sides of the rail vehicle and the corresponding sections of the two opposite rails between the wheel contact points on the respective side. Rather, a suitably arranged and configured primary induction loop may effect a voltage in a secondary loop passing through only a portion of a rail on one side of the rail vehicle, two wheels at the ends of that section and an electrical connection e.g. can be formed over vehicle mass (formed by the chassis).

When it is said in this specification that the voltage induced in the secondary loop maintains the electrical wheel-rail contact, it should be noted that the electric current generated by the induced voltage makes a significant contribution thereto. If the current z. B. flows via a wheel-rail contact and is suddenly interrupted, arises at the contact a high electrical voltage z. B. via arcing the contact recovers and removes or breaks through electrically insulating coverings.

In a possible variant of the induction loop, this has not only one turn, but at least two turns, which rotate about the same area.

Furthermore, it is possible that the current of the induction loop is not fed (as preferred) galvanically directly from a feed device (e.g., the above-mentioned power generating device) into the secondary loop, but the feed device is galvanically decoupled from the induction loop and e.g. magnetically according to the principle of a current transformer, the supply is generated.

According to the claims, the feeder feeds the induction loop intermittently when the vehicle is stationary, but feeds it continuously while the vehicle is moving. This is especially true when the vehicle is towed, e.g. in a non-upgraded electrically powered locomotive. This is based on the idea that when the vehicle is towed, intermittent operation of the induction loop may not be sufficient, in particular on routes that are not frequently used, in order to continuously produce the required low-resistance connection between the rails. The wheels of the vehicle constantly come in contact with other locations on the surface of the rails

• Die Speiseeinrichtung kann einen (insbesondere zweipoligen) Anschluss zum Anschließen der Speisseinrichtung an eine Energiequelle (z. B. eine Fahrzeugbatterie oder ein fahrzeugexternes Versorgungsnetz) und eine elektronische Schalteinrichtung aufweisen, die bei intermittierender Speisung eine elektrische Verbindung zwischen der Energiequelle und der Induktionsschleife wiederholt unterbricht, um die zeitlichen Unterbrechungen der Speisung zu bewirken.

In particular, for the previously mentioned case of continuous supply while the vehicle is moving, but also for the likewise conceivable case that the induction loop is continuously fed even when the vehicle is stationary for a long period of time. but over a different period of time only intermittently, the following embodiments are suitable:

• The feeder may include a (particularly two-pole) port for connecting the feeder to an energy source (eg, a vehicle battery or an off-board supply network) and an electronic switching device that interrupts an electrical connection between the power source and the induction loop repeatedly during intermittent feed, to effect the time interruptions of the supply.

In particular, the feed device can identify an inverter (eg an oscillator), wherein the switching device is arranged between the connection for connecting the feed device to the energy source, so that in intermittent operation, the connection of the inverter to the connection is made only intermittently, that is repeatedly interrupted , Alternatively, the switching device parallel to the To be switched inverter, that is, the connection is connected in parallel via the inverter and the switching device with the induction loop, in particular via one line.

In particular, an AC source of the feeder can be realized by a combination of a DC source (eg, the vehicle battery) and an inverter (eg, an oscillator), the DC source being connected to the DC side of the inverter and the AC side of the inverter being connected to the induction loop , In this case, the electronic switching device is preferably arranged on the DC side of the inverter. In another embodiment with an inverter, the induction loop is fed with alternating current from the inverter during continuous supply and, in the case of intermittent supply, fed via an electronic switching device connected in parallel to the inverter to the induction loop, which cuts off the supply repeatedly, in order to limit the supply interruptions cause. Also in this embodiment, a DC power source may be used for the intermittent feed operation. In this case, the electronic switching device can take over the function of the inverter (in particular the oscillator) and repeatedly switch on and off the connection between the DC source and the induction loop during the intermittent supply. The duration of the electrical supply of the induction loop is z. B with only a single current oscillation in the induction loop with e.g. a frequency greater than 50 kHz (i.e., oscillation time T = 20 μs) is much shorter compared to the de-energized pause time of e.g. 0.1s to 10s.

In particular, in order to automatically determine whether a continuous or intermittent operation of the induction loop is to take place, a sensor or a combination of sensors is preferably used. The sensor or sensors are connected to a control unit of the feed device, wherein the feed device feeds the induction loop either continuously or intermittently with alternating current depending on a signal of the sensor or sensors. The feeding device therefore consists in this case not only of a switching device (eg the electronic switching device, see above), but has at least one signal input for receiving a sensor signal. Also, the actual power source and, if present, the aforementioned inverter (eg, the oscillator) are parts of the entire feeder.

In the case of electrically powered rail vehicles, a sensor is preferably used (for example, feedback contacts of the current collector and / or main switch), which detects whether the vehicle has been upgraded, ie, is connected to the energy supply network. The arrangement and design of such sensors is known per se in rail vehicles (but not the use for the purpose described here) and is therefore not described here in detail. In particular, the driver must have knowledge of whether the vehicle is upgraded.

In the case of vehicles operating on routes with different train protection systems (for example when operating in different countries), switching to the respective train protection system is carried out partly by manual switching, partly by automatic switching depending on the respective train protection system, the supply of the induction loop can therefore be activated or deactivated. Accordingly, a detection device can be provided which generates a signal depending on a currently active train protection system.

Another sensor which is preferably used to control the continuous or intermittent operation of the induction loop is an air pressure sensor which generates a signal depending on the air pressure in the brake system of the rail vehicle. If the pressure in the brake system z. B. sufficient for driving, this is an indication that the vehicle is not parked for long periods. For example, in combination with and / or the sensor (s) described below, a more reliable statement as to whether the vehicle is running or stationary can be made.

Such another sensor is a vibration sensor that generates a signal depending on whether or not the vehicle is subject to vibration during travel. As an alternative or in addition to the vibration sensor, a speed sensor can be used which generates a signal depending on the driving speed of the vehicle

Further embodiments of the method and variants of the method for operating a rail vehicle result from the description of the various measures and configurations of the towing vehicle and are therefore not described again here.

Fig. 1

schematisch eine Anordnung mit zwei Drehgestellen eines Schienenfahrzeugs, die auf zwei Schienen rollen, und einer Induktionsschleife des Schienenfahrzeugs, die eine Wechselspannung in einer Sekundärschleife induziert,

Fig. 2

eine erste Ausführungsform einer Speiseeinrichtung mit einer daran an- geschlossenen Induktionsschleife, z.B. der Induktionsschleife gemäß Fig. 1,

Fig. 3

eine zweite Ausführungsform einer Speiseeinrichtung mit angeschlossener Induktionsschleife,

Fig. 4

ein Ausführungsbeispiel der in Fig. 2 dargestellten Speiseeinrichtung und

Fig. 5

ein Ausführungsbeispiel der in Fig. 3 dargestellten Speiseeinrichtung.

Embodiments of the invention will now be described with reference to the accompanying drawings. The individual figures of the drawing show:

Fig. 1

2 schematically shows an arrangement with two bogies of a rail vehicle rolling on two rails and an induction loop of the rail vehicle which induces an alternating voltage in a secondary loop;

Fig. 2

a first embodiment of a feed device with an induction loop connected thereto, for example, the induction loop according to Fig. 1 .

Fig. 3

a second embodiment of a feed device with a connected induction loop,

Fig. 4

an embodiment of in Fig. 2 illustrated dining and

Fig. 5

an embodiment of in Fig. 3 shown feeding device.

Fig. 1 shows two bogies 107,119 with two axes 105, 106; 108, 109. On each of the axles 105, 106, 108, 109 there is a respective wheel 115a-115d at opposite ends; 116a-116d arranged. The wheels 115a, 115c, 116a, 116c roll on a first rail 101. The wheels 115b, 115d, 116b, 116d roll on the opposite second rail 102 of a track.

In the longitudinal direction of the rail vehicle, ie in the direction of travel between the bogies 107, 119, there is an induction loop 1, which rotates around a substantially rectangular surface 130 that extends in a horizontal plane. Accordingly, the induction loop 1, a first line section 1 a, which extends approximately above the first rail 101 and parallel to this, a second line section 1b, which extends approximately above the second rail 102 and parallel to this, a third line section 1 c which is connected to one end of the first portion 1a and extends across the rails 101, 102 in a horizontal direction, and a fourth portion 1d which connects another end of the first portion 1a to one end of the portion 1b and also across the rails 101, 102 extends in an approximately horizontal direction. The not yet mentioned ends of the sections 1 c, 1 b are connected to a power generating circuit 53, the z. B. is designed as an oscillator circuit. Indicated in Fig. 1 a voltage U ₁ , with which the oscillator circuit 53 feeds the induction loop 1. The voltage U, is an alternating voltage with a frequency which is preferably in the middle frequency range. The power generating circuit 53, which functions as an AC power source, is ensured in particular by the electric power supply on board the vehicle (for example, on-board battery).

Quite generally, for the present invention, a feed frequency for feeding the at least one induction loop in the middle frequency range is preferred. The lower limit for the frequency is in the range of 50 kHz, preferably a feed frequency between 100 kHz and 160 kHz is selected. The upper limit for the feed frequency is e.g. at about 500 kHz. At higher frequencies, compliance with the applicable regulations regarding electromagnetic compatibility (EMC) is made more difficult.

Preferably, the supply frequency coincides with a resonant frequency of the oscillating system (eg, L-C resonant circuit), part of which is the induction loop.

Since the induction loop 1 is between the two bogies 107, 119 and since both bogies have two axes, an associated secondary loop, in which the induction loop induces a voltage, through all four axes, the associated wheels and the rail sections of the two rails 101, 102nd formed between the bogies. This is true in the case where the electrical contact of each of the wheels to the associated rail is made low impedance or at least made by the induced voltage. However, it is also possible that at least one or more of the wheels do not have sufficiently low-resistance contact with the associated rail even when a voltage is induced, and therefore part of the axes does not contribute to the production of the low-resistance connection. The common magnetic flux through the primary loop 1 and the secondary loop is indicated by a ring line with an arrow and the symbol Fh.

Unlike in FIG. 1 is illustrated, the primary induction loop may be disposed within a bogie. For redundancy reasons, several primary induction loops can be arranged. The required for generating an induction voltage in the secondary circuit magnetic field can be caused by one or more turns of the primary induction loop (s). The inductive coupling of the induction loop (primary loop) to the secondary loop depends on the distance of the primary loop to the track and on the clamped surface.

In the case of the intermittent operation proposed here, it is utilized that, for the purpose of breaking through an oxide / corrosion layer between the wheels on the one hand and the rails, on the other hand, an electrical voltage of a certain height is required. To Voltage breakdown then passes a much lower voltage to obtain the low-resistance connection. The voltage applied between the rails (which may be less than 1 V in unfavorable cases) of the track-free signaling device (not shown in the figures, eg in a signal box on the route of the vehicle) and the resulting weak current flow are sufficient, to obtain the required low resistance for a limited time.

A first embodiment of a feed device, which makes it possible to secure a low-resistance electrical wheel-rail connection even during prolonged downtimes of a vehicle and consumes very little energy (eg from the on-board battery), is known in US Pat Fig. 2 shown.

The induction loop 1 is connected to the AC side (with electrical connections 61, 62) of an inverter (eg oscillator) 2 via electrical connections 63, 64 and a coaxial cable 60 connected thereto. The DC side of the inverter 2 has a first terminal 51 for connecting a positive potential and a second terminal 52 for connecting a negative potential. However, the invention is not limited to this polarity, the polarity may also be reversed, i. The components described below can also be arranged in the line to the negative pole.

The negative terminal is connected to the negative pole of a DC power supply, here the vehicle battery 59. The positive pole 51 is connected to a first terminal p of a switch 58. Furthermore, the positive pole 51 is connected via a parallel line and via a switching device 55 to a second terminal i of the switch 58. The switch 58 is able to switch between the terminals i and p, so that a third terminal m of the switch 58 is connected to either the Anschlußi or the terminal p depending on the switching state When the positive potential of the DC power supply 59 is applied to the terminal m and In addition, the terminal m is connected to the terminal p, the inverter is operated continuously and therefore the induction loop 1 is continuously supplied with alternating current. On the other hand, when the switch 58 connects the terminals m and i, the switching means 55 makes intermittent operation of both the inverter and the induction loop 1 by only temporarily connecting the inverter to the DC power supply 59.

In principle, it would also be possible to place the switching device between the AC voltage side of the inverter and the induction loop 1. However, this would mean unnecessary losses due to load-free operation of the inverter 2.

Between the connection m of the switch 58 and the positive pole of the DC power source 59, a circuit breaker (eg a circuit breaker) 74 is optionally arranged

Furthermore, a control will be described, which in Fig. 2 is shown schematically and may not be present in other embodiments. To this control includes a further switch 57, which is arranged in series with the switch 58. The two switches 57,58 are parts of a controllable unit 95 for switching the operating modes and for switching on or off the feeder. The switch 57 is controlled by a sensor signal 73, which contains, for example, the information about whether the vehicle is upgraded and / or in which country or which rail network the vehicle is located. Depending on the country or rail network and / or the question of whether the vehicle is upgraded or disarmed, a feed operation of the induction loop 1 is required or not. The sensor signal 73 accordingly leads to closing or opening of the switch 57.

The switching state of the switch 58 depends on one or more sensor signals. In the exemplary embodiment, the sensor signals are: a signal of an air pressure sensor for measuring the air pressure in a brake system of the vehicle (70), the signal 71 of a speed sensor for measuring the vehicle speed or for transmitting the information as to whether the vehicle speed exceeds a minimum speed (eg Speed near 0) and a sensor signal 72 of a vibration sensor for transmitting the information as to whether the vehicle is subjected to vibrations that usually occur when driving the vehicle, eg Vibrations in the bogie. Instead of sensor signals 70, 71, 72, 73 and pure switching signals to the switches 57, 58 can be transmitted, which are then dependent on the sensor signals.

It is possible that either the device 95 evaluates sensor signals or the evaluation is performed elsewhere and only switching signals are transmitted to the device 95.

An embodiment of the switching device 55 and the inverter is still based on Fig. 4 received.

The switching device 55 may, for. B. be an electronic relay, which cyclically on and off the downstream inverter 2.

FIG. 3 shows an alternative arrangement Fig. 2 , Identical and functionally identical components and elements are designated by the same reference numerals. According to Fig. 3 On the output side of the AC power source (that is, on the AC side of the inverter 2), a changeover switch 75 is arranged. Depending on the requirements of the logic of the device 95, the switch 75 is switched in position p to the permanent (ie continuous) supply of the induction loop 1 (preferably with a predetermined medium frequency operating AC source), or in position i to an intermittently operating pulse circuit 76. In the arrangement according to Fig. 3 Therefore, there are two independent food combinations that optionally feed the induction loop 1.

The pulse circuit 76 in FIG Fig. 3 is designed to generate a defined high voltage in the clamped track loop preferably such that set in the induction loop 1 during the switch-on periods, a vibration frequency and a swing current, which are comparable to the sizes in the feed combination with inverter 2. On an embodiment of the pulse circuit 76th and the inverter will be discussed with reference to FIG. 6.

1. a) alle Betriebszustände bei aufgerüstetem Fahrzeug (die Induktionsschleife wird kontinuierlich mit Wechselstrom gespeist)
2. b) dem Stillstandsbetrieb bei abgerüstetem Fahrzeug (das Fahrzeug ist abgestellt und die Induktionsschleife wird intermittierend mit Wechselstrom gespeist)
3. c) dem geschleppten Betrieb (das Fahrzeug ist abgerüstet und wird durch ein anderes Fahrzeug geschleppt, die Induktionsschleife wird kontinuierlich mit Wechselstrom gespeist).

According to a preferred control regulation for controlling the operation of the feed device according to Fig. 2 and 3 the following operating states are distinguished:

1. a) all operating conditions when the vehicle is upgraded (the induction loop is continuously supplied with alternating current)
2. b) the standstill operation when the vehicle is dismantled (the vehicle is parked and the induction loop is intermittently fed with alternating current)
3. c) the towed operation (the vehicle is disarmed and towed by another vehicle, the induction loop is continuously supplied with alternating current).

• Fahrzeugluftdruck-Sensor, der insbesondere Teil der Bremssteuerung sein kann: Bei angekuppeltem Fahrzeug (Schleppbetrieb) erhält die Bremsanlage durch pneumatische Verbindung der angehängten Wagen einen entsprechenden Luftdruck, um die Bremse zu lösen. Das Überschreiten des Luftdrucks über einen definierten Schwellwert wird z.B. von der Schaltlogik in Einrichtung 95 in Fig.2 ausgenutzt, um eine Umschaltung vom intermittierenden in den kontinuierlichen Speisebetrieb der Induktionsschleife vorzunehmen (Umschalter 58 wird in Stellung p geschaltet).
• Geschwindigkeitssensor: Ober einen separaten Geschwindigkeitssensor z. B. eine Kombination von Ultraschallsensoren oder auch über eine auf dem Fahrzeug ohnehin vorhandene Geschwindigkeitsmesseinrichtung wird bei einer Geschwindigkeit, die größer als null ist, der kontinuierliche Speisebetrieb aktiviert.
• Vibrationssensor: Beim Bewegen des Fahrzeugs entstehen Erschütterungen / Beschleunigungen die vom Sensor erfasst werden. Durch die Logik der Einrichtung 95 wird eine entsprechende Umschaltung in den kontinuierlichen Speisebetrieb vorgenommen wird.

Switching from the intermittent feed at standstill and the continuous feed when the vehicle is towed is done by exceeding one or more thresholds of the following sensors:

• Vehicle air pressure sensor, which may be part of the brake control in particular: When the vehicle is coupled (towing) receives the brake system by pneumatic connection of the attached car a corresponding air pressure to release the brake. Exceeding the air pressure over a defined Threshold, for example, from the switching logic in device 95 in Fig.2 used to make a switch from the intermittent to the continuous operation of the induction loop (switch 58 is switched to position p).
• Speed sensor: above a separate speed sensor z. B. a combination of ultrasonic sensors or via an existing on the vehicle anyway speed measuring device is activated at a speed that is greater than zero, the continuous feed operation.
• Vibration sensor: When moving the vehicle, vibrations / accelerations are detected by the sensor. By the logic of the device 95, a corresponding switch is made in the continuous feed operation.

The switchover from continuous to intermittent feed operation preferably takes place only after expiry of a defined minimum period after elimination of the switch-on criterion for the continuous feed operation.

The ratio of switch-on to switch-off time is z. B. chosen so that the energy consumption when the vehicle is at least 10 times lower compared to the self-discharge of the power battery (eg., 59 in.) Fig. 2 ). By choosing the ratio of the switched on and off periods during the intermittent operation (eg less than 1/200) this can be ensured. The described effect of a permanent low-impedance track connection at vehicle standstill with negligible energy consumption for the feed device can be such. B. in a switching rhythm (playing time) of 1 to 5 s and a duty cycle of 1-5 ms are realized.

Conveniently, the inverter 2 forms in Fig. 2 together with the connected induction loop 1 an LC resonant circuit. The induction loop forms the inductance, the resonant circuit capacitance is part of the inverter 2. About a corresponding coupling in the inverter 2, the resonant circuit is excited to oscillate and is provided for a stationary oscillation. Vibration frequency and current are selected such that in the resulting by the Radaufstandspunkte (contact points between the wheel and rail) secondary loop a defined high induction voltage is generated in order to break the oxide layers between the wheel and rail.

In Fig. 4 the switching device 55 and the inverter 2 of the feed device according to Fig. 2 illustrated as embodiment more concrete. The terminal 1 of the switch 58 is connected to a first resistor R60, to whose second terminal a thyristor TH1 is connected. Above the thyristor TH1, the first resistor R60 is connected to an electrical terminal 512 of the inverter 2. The forward direction of the thyristor TH1 is directed so that the positive current flow direction leads from the first resistor R60 to the terminal 512.

Between the second terminal of the first resistor R60 and the lower (here negative) potential battery line between terminal 52 of the inverter and the negative battery terminal of the battery 59, a first capacitor C60 is connected.

Also connected to the second terminal of the first resistor R60 and in parallel with the thyristor TH1 is a series connection of a second resistor R51 and a second capacitor C50.

At a contact point between the second resistor R51 and the second capacitor C50, a control circuit for igniting the thyristor TH1 is connected. This control circuit comprises a diode D51 and a flip-flop D52, which are connected in series with each other, wherein the flip-flop D52 is connected to the ignition terminal of the thyristor TH1.

This embodiment of the switching device could also be combined with another embodiment of the inverter 2 described below. The basic principle of In Fig. 4 illustrated embodiment of the device 55 is that only analog electrical components are used without software control. Therefore, the development cost is low with high reliability of the circuit. On the operating principle of the switching device 55 will be discussed.

Also, the inverter 2 is realized exclusively using analog electrical components. The electrical connection 612 leads to a contact point 217, which is connected via a diode D2 to an electrical connection 511 of the inverter. This terminal 511 is connected to the contact p of the switch 58. In this case, the forward direction of the diode D2 is selected such that the positive current leads from the contact p via the diode D2 to the contact point 217.

With the contact point 217, a series circuit of two inductors L3, L1 is connected. In parallel, another series circuit L3, L1 is connected, which is not connected directly to the contact point 217, but with the electrical connection 52, which leads to the negative terminal of the battery 59. A capacitor C4 connects contact points 218, 219, which respectively lie between the inductors L3, L1. The two parallel series circuits of the inductors L3, L1 thus define a first side respectively at the inductance L3, which is closer to the battery 59, and a second side, which is closer to the induction loop 1. On this second side, the series connections of the inductors L3, L1 are connected via a voltage divider, i. a series connection of resistors R5, R6, connected together. A contact point between the resistors R5, R6 is connected to the control terminal of a transistor T1, i. e.g. connected to the base of the transistor T1. In this case, the second side of the first series circuit of the inductors L3, L1, which is connected to the diode D2, connected via a further resistor R3 to the collector of the transistor T1. The second side of the second series circuit of the inductors L3, L1 is connected on the one hand via a resistor R2 to the emitter of the transistor T1 and the other via a further capacitor C10 connected to the collector of the transistor T1. Further, between the second side of the second series connection of the inductors L3, L1 and the base of the transistor T1, a further capacitance C20 is connected in series with yet another capacitor C3 and a resistor R4. The capacitors C10 and C20 form a series connection, at the outer terminals of the coaxial cable 60 via the terminals 61, 62 is connected. As follows from what has already been described, an electrical contact point between the series-connected capacitances C20, C10 is connected to the second side of the second series connection of the inductors L3, L1.

• Der Wechselrichter 2 ist ein selbsttätig schwingender Oszillator. Die Induktivität der Induktionsschleife 1 bildet zusammen mit den Kapazitäten C10, C20 einen Schwingkreis. Durch eine Rückkopplung einer Teilkondensatorspannung auf die Basis des Transistors T1 wird eine Mitkopplung erreicht, die ein zyklisches Einschalten des Transistors T1 während der negativen Halbschwingung von C20 bewirkt. Das phasenrichtige Ein- und Ausschalten des Transistors unterstützt den durch den Schwingvorgang hervorgerufenen Entlade- und Aufladevorgang des Kondensators C10 und sorgt für eine kontinuierliche Anregung und damit für die Aufrechterhaltung der Resonanzschwingung.

The functioning of in Fig. 4 The circuit shown is as follows:

• The inverter 2 is a self-oscillating oscillator. The inductance of the induction loop 1 forms a resonant circuit together with the capacitances C10, C20. By a feedback of a partial capacitor voltage to the base of the transistor T1, a positive feedback is achieved, which causes a cyclical switching on of the transistor T1 during the negative half-cycle of C20. The in-phase on and off of the transistor supports the induced by the vibration process discharging and charging of the capacitor C10 and provides a continuous excitation and thus for the maintenance of the resonant vibration.

With the resistors R3 and R2, the height of the output AC voltage UA between the points 61 and 62 can be adjusted. The capacitor C3 is used to decouple the DC voltage component of the voltage, which drops across capacitor C20. The resistance R4 influences the operating point of the transistor.

The inductance L1 causes a reduction of the AC component in the supply source, whereby the losses are reduced and the self-oscillation of the oscillator circuit is improved when applying the DC voltage. The capacitance C4 and the inductance L3 form an input filter for decoupling the oscillator circuit from the power source 59.

In the intermittent mode, the filter capacitor C4 is charged by cyclically firing the thyristor TH1 by a swinging operation via the capacitor C60, the inductor L3 and the capacitor C4. The switching device 55 has - as mentioned - a parallel connection of a thyristor TH1 and an RC element (resistor R51, capacitance C50). When a voltage across the capacitor C50 defined by the dimensioning of the electrical components used is exceeded, the thyristor TH1 is ignited via the flip-flop diode D52. An oscillatory process forms over the charged capacitance C60, the inductance L3 and the discharged filter capacitor C4. The capacitor C4 is charged approximately to twice the voltage of the capacitor C60. The higher voltage across the capacitor C4 causes the thyristor TH1 to go out.

With the energy stored in capacitance C4, the oscillator oscillates for a defined time (e.g., 1-5 ms) according to the dimensioning of the electrical components used, and consumes the energy stored in capacitance C4. Thereafter, a renewed charging of the capacitor C50 continues until it reaches the breakdown voltage of the flip-flop diode D52 and initiates the next ignition process of the thyristor TH 1. The resistor R60 and the capacitor C60 form a decoupling to the energy source 59.

In the Fig. 5 illustrated special embodiment of the circuit according to Fig. 3 differs from the specific embodiment according to Fig. 4 only in a modification of the switching device 76 relative to the switching device 55 and in the terminal of the switching device 76. This switching device 76 is not connected as the switching device 55 via an electrical contact 512 to the inverter on the DC side. Rather, the switching device 76 via a electrical contact 513 connected to the switch 75, which is connected directly to the coaxial cable 60.

Furthermore, a further current path is provided in the switching device 76 parallel to the current path through the first resistor R60 and the thyristor TH1, which connects the negative terminal of the power source 59 via a resistor R61 to the electrical terminal 62 on the AC side of the inverter 2. Thus, this current path is also connected to the coaxial cable 60. Between the two named current paths, i. as connection of the resistors R60, R61, a capacitance C60 is provided.

Furthermore, a diode D53 is connected in parallel to the thyristor TH1, in the reverse current flow direction to the thyristor TH1.

The function of the specific embodiment according to Fig. 5 is as follows

The capacitor C60 and the inductance L of the induction loop 1 in turn form a resonant circuit. The capacitor C60 is charged via the decoupling resistors R60, R61. At the same time, the capacitance C50, which is parallel to the thyristor TH1, is charged via the resistor R51. When a voltage across the capacitor C50 defined by the components used is exceeded, the thyristor TH1 is triggered via the flip-flop diode D52.

The voltage across the capacitor C60 oscillates via the thyristor TH1 and the induction loop 1 back to negative polarity and immediately thereafter via the anti-parallel to the thyristor diode D53 back. The resonant circuit capacitor C60 is recharged via the resistors R60, R61. At the same time, the recharging of the capacitor C50 via the resistor R51 until the breakdown voltage of the flip-flop D52 is reached again and the thyristor TH1 ignited and thus a renewed oscillation process is initiated.

The repetition frequency of the oscillatory processes, ie the frequency of the thyristor ignition is determined by the time constant of the RC element consisting of the capacitance C50 and the resistor R51. For the function of the pulse operation, the diode D53 connected in antiparallel to TH1 can also be dispensed with. In this case, only one half-wave takes place at a time. The capacitor voltage C60, curved to negative polarity, must In this case, the resistors R60, R61 can be completely recharged to positive potential.

Claims (7)

1. A rail vehicle having an induction loop (1) for guaranteeing a low-resistance electrical connection between wheels (115, 116) of the rail vehicle and rails (101, 102) over which the wheels (115, 116) roll, by induction of an electric voltage in a secondary current loop formed by the wheels (115, 116), by portions at least of one of the rails and by electrical connections between wheels (115, 116), the rail vehicle comprising a feed means which intermittently applies an electrical alternating voltage to the induction loop so that the induction loop (1) is fed with alternating current with temporal interruptions, characterised in that the rail vehicle comprises at least one sensor and/or a device which is connected to the feed means, the feed means feeding the induction loop with alternating current either continuously or intermittently according to a signal of the sensor/the device.
2. The rail vehicle according to the preceding claim, wherein the sensor/device or the sensors/devices is/are selected from the following group: a set-up sensor which generates a signal according to whether a current collector for collecting current from an electric power grid is activated or deactivated, a detection device which generates a signal according to a currently active train protection system, an air pressure sensor which generates a signal according to an air pressure in a braking system of the rail vehicle, a vibration sensor which generates a signal according to whether the vehicle is exposed to vibrations occurring during travel, and a speed sensor which generates a signal according to the travelling speed of the vehicle.
3. The rail vehicle according to any one of the preceding claims, wherein the induction loop (1) is fed with alternating current from a converter (2) in the case of continuous feed, and in the case of intermittent feed is fed via an electronic switchgear (76) which is parallel to the converter, is connected to the induction loop (1) and which repeatedly interrupts the feed so as to effect the temporal interruptions of the feed.
4. A method for operating a rail vehicle, in which, in order to guarantee a low-resistance electrical connection between wheels (115, 116) of the rail vehicle and rails (101, 102) over which the wheels (115, 116) roll, an electrical voltage is induced in a secondary current loop formed by the wheels (115, 116), by portions at least of one of the rails (101, 102) and by electrical connections between wheels (115, 116), an electrical alternating voltage being intermittently applied to a primary induction loop (1) to generate the induced voltage so that the induction loop is fed with alternating current with temporal interruptions, characterised in that the induction loop is fed intermittently in the case of a stationary vehicle, but is fed continuously in the case of a moving vehicle.
5. The method according to the preceding claim, wherein the induction loop is fed with alternating current from the same converter (2) in the case of intermittent feed and in the case of continuous feed.
6. The method according to claim 4, wherein the induction loop is fed with alternating current from the converter (2) in the case of continuous feed, and in the case of intermittent feed is fed via an electronic switchgear (76) which is parallel to the converter, is connected to the induction loop and which repeatedly interrupts the feed so as to effect the temporal interruptions of the feed.
7. The method according to any one of the three preceding claims, wherein the feed of the induction loop (1) with alternating current is operated continuously or intermittently according to whether a signal and/or which signal is generated by at least one sensor and/or one device, wherein the sensor/the device or the sensors/devices is/are selected from the following group: a set-up sensor which generates a signal according to whether a current collector for collecting current from an electric power grid is activated or deactivated, a detection device which generates a signal according to a currently active train protection system, an air pressure sensor which generates a signal according to an air pressure in a braking system of the rail vehicle, a vibration sensor which generates a signal according to whether the vehicle is exposed to vibrations occurring during travel, and a speed sensor which generates a signal according to the travelling speed of the vehicle.

Images