EP4719805A1

EP4719805A1 - Sensorized pantograph

Info

Publication number: EP4719805A1
Application number: EP24728985.3A
Authority: EP
Inventors: Francesco Castelli Dezza; Giuseppe BUCCA; Marco MAURI; Federico ZANELLI; Nicola DEBATTISTI; Giorgio Diana
Original assignee: Fondazione Politecnico Di Milano
Current assignee: Fondazione Politecnico Di Milano
Priority date: 2023-05-30
Filing date: 2024-05-23
Publication date: 2026-04-08
Also published as: WO2024245906A1; IT202300010896A1

Abstract

Sensorized pantograph (10) comprising: at least one raising arm (11); a bow (12) on top of the at least one raising arm (11), the bow (12) configured to provide an electric contact with an aerial cable line; a sensor unit (20) comprising at least one accelerometer, the sensor unit (20) configured for a measure of the pantograph (10) and/or of the aerial cable line, the sensor unit (20) comprising a wireless transmitter; a thermoelectric generator (30) on a surface of the bow (12) and being configured to power the sensor unit (20).

Description

Title: Sensorized pantograph

DESCRIPTION

Technical field

The present invention relates to a sensorized pantograph. In general, the present invention finds application in the field of electrically powered vehicles, since it concerns current collectors from power lines.

Prior art

In electrically powered vehicles, such as trains, trams or trolleybuses, sensors for monitoring and measuring the forces exchanged between the pantograph and the aerial lines can be provided. These sensors typically comprise accelerometers.

Document US2018208222A1 relates to a monitoring system of a train pantograph, which includes one or more sensors mounted on or integrated with the pantograph of the train, a data collection unit for receiving signals or data from the sensors and a processing unit for determining the structural status of the pantograph. The sensors and the data collection unit are mounted on the pantograph, while the processing unit is installed in a low-voltage point (for example, 24 V AC) on the train, and the data collection unit wirelessly communicates with the processing unit.

Document KR 102174316B1 relates to a power supply device for a detection device of pantograph and, more in particular, for collecting electricity through a magnetic field and an electric field by a current provided to the pantograph such that it can be used as power supply source for a detection device for detecting a pantograph.

Document KR 100711737B1 relates to a measurement system of a catenary and pantograph status, comprising a sensor unit attached to the catenary which includes a catenary measurer and a unit for transmitting the signal via radio to a receiving part of a processor of the ground signal of the catenary for the analysis and the storage thereof.

However, known systems involve installation complexity and are not efficient, in particular regarding the signal transmission and the power supply to the sensor and to the wireless transmitter, if any.

Summary of the invention

Object of the present invention is to overcome drawbacks of the prior art.

A further particular object of the present invention is to provide a pantograph provided with a self-powered wireless sensor, capable of monitoring the contact forces between the pantograph and aerial cable lines, for both AC and DC lines.

These and other objects are achieved by a sensorized pantograph according to the features of the attached claims, which form integral part of the present description.

An idea underlying the present invention is to provide a thermoelectric generator, in particular based on the Seebeck effect, to power the sensor of the pantograph.

The invention therefore provides a sensorized pantograph which comprises at least one raising arm, and a bow on top of the at least one raising arm. The bow is configured to provide an electric contact with an aerial cable line.

The pantograph comprises a sensor unit comprising at least one accelerometer. The sensor unit is configured for a measure of the pantograph and/or of the aerial cable line. The sensor unit comprises a wireless transmitter.

The pantograph comprises a thermoelectric generator on a surface of the bow. The thermoelectric generator is configured to power the sensor unit. Advantageously, the thermoelectric generator uses heat generated in the area of the bow, due to both electrical and frictional effects, for generating power intended to supply the sensor unit.

Advantageously, the sensor unit provides a wireless transmitter, which does not require an additional cable for transmitting data.

Thereby, the sensorized pantograph of the present invention provides a self-powered wireless sensor, which is capable of monitoring the contact forces between pantograph and aerial cable lines, for both AC and DC lines.

Further features and advantages will be more evident from the detailed description made hereinafter of preferred non-limiting embodiments of the present invention and from the dependent claims, which outline preferred and particularly advantageous embodiments of the invention.

Brief description of the drawings

The invention is illustrated with reference to the following figures, provided by way of non-limiting example, wherein:

Figure 1 illustrates a pantograph.

Figure 2 illustrates a bottom view of the bow of the pantograph of Figure 1.

Figure 3 illustrates a thermoelectric generator.

Figure 4 illustrates a sectional view of the thermoelectric generator of Figure 3.

Figure 5 illustrates a sectional view of a sensor unit.

Figure 6 illustrates a first electronic board of the sensor unit of Figure 5.

Figure 7 illustrates a second electronic board of the sensor unit of Figure 5.

In different figures, analogous elements will be identified by analogous reference numbers.

Detailed description

The sensorized pantograph of the present invention provides a wireless sensor device for monitoring pantograph and associated catenary of an aerial line cable.

The wireless sensor device is self-powered by a thermoelectric generator associated with the pantograph.

These elements will be described more in detail with reference to an exemplary non-limiting embodiment.

Figure 1 illustrates a pantograph 10 which comprises at least one raising arm 11. The at least one raising arm 11 can for example form a parallelogram with articulated arms, according to different configurations which are known to the those skilled in the art and which will not be further examined for the sake of brevity.

The electrical transmission system for some electric vehicles, for example trains, comprises an upper carrying cable (known as catenary) from which an electric contact cable is suspended, whose assembly is herein defined as “aerial cable line”.

The pantograph 10 can be spring-loaded to push a contact pad against the lower part of the aerial cable line in order to collect the current necessary to operate the vehicle, such as the train.

The pantograph 10 comprises a bow 12 on top of the at least one raising arm 11. The bow 12 is configured to provide an electric contact with the aerial cable line, in particular by the contact pad 13 above the bow 12.

The pantograph 10 further comprises a sensor unit 20 which comprises at least one accelerometer. The sensor unit 20 is configured for sensing the pantograph 10 and/or of the aerial cable line. The term sensor “unit” means a device composed of a plurality of elements and configured for sensing, it being understood that if a plurality of sensors or elements of the sensor unit are spatially separated from each other, they still represent a sensor unit analogous to the sensor unit 20 exemplified herein.

The at least one accelerometer of the sensor unit 20 acquires acceleration signals to which the pantograph 10 is subjected due to the interaction with the aerial cable line. In particular, the sensor unit 20 is configured for a dynamic acquisition of signals for a subsequent processing and monitoring of the pantograph 10 and/or of the aerial cable line; the analysis of these signals is useful for monitoring and diagnostic activities of the aerial cable line and of the pantograph 10. As it will be further described, the sensor unit 20 already performs on-board operations for the management of the acquired data, including possible pre-processing operations of the data. Furthermore, the sensor unit 20 comprises a wireless transmitter for sending data, for further processing and monitoring the pantograph 10 and the aerial cable line.

Figure 2 illustrates a bottom view of the bow 12, in which the already- described sensor unit 20 is visible. Preferably in proximity of the sensor unit 20, the pantograph comprises a thermoelectric generator 30. The thermoelectric generator 30 is on a surface of the bow 12. The thermoelectric generator 30 is configured to power the sensor unit 20.

Preferably, the thermoelectric generator 30 is positioned on a suitable surface of the bow 12 which is capable of heating up due to the interaction between pantograph 10 and aerial cable line; this heating is in particular due both to the friction and to the current flow.

Preferably, the thermoelectric generator 30 is provided in a position under the slider-holder of the bow 12 of the pantograph 10. In the exemplified embodiment, the thermoelectric generator 30 is applied onto the surface of the bow 12. This application or assembly of the thermoelectric generator 30 can take place during manufacturing of the pantograph 10, or at a later moment as retrofit to an already-existing pantograph 10.

In a non-shown variant, the thermoelectric generator could be integrated in the bow 12, for example in a recessed surface of the same bow 12. Such an integration can be provided particularly during the manufacturing of the pantograph 10.

Preferably but not in a limiting manner, the sensor unit 20 is also applied onto a surface of the bow 12 and comprises a cabled connection 40 to the thermoelectric generator 30.

Figure 3 illustrates in greater detail a non-limiting example of a thermoelectric generator 30.

The thermoelectric generator 30 comprises a plate 31, in particular a metal plate, for application to the respective surface of the bow 12.

The thermoelectric generator 30 comprises a dissipator 32 with protrusions which are configured to increase a convective exchange.

In order to minimize the weight of the thermoelectric generator 30, the dissipator 32 is preferably made of aluminum.

In the non-limiting embodiment, the thermoelectric generator 30 has bulks of approximately 90x50 mm, a height of approximately max 15-20 mm, a weight of approximately 50-60 g, generally lower than 75g.

The thermoelectric generator 30 is in particular mounted in a suitable position with the plate 31, in particular a metal plate, preferably being in direct contact with the surface of the bow 12.

Figure 4 illustrates a sectional view of the thermoelectric generator 30. The thermoelectric generator 30 comprises one or more thermoelectric elements 33 interposed between the plate 31 and the dissipator 32.

The thermoelectric elements 33 are configured to generate the electric power used to power the sensor unit 20. The thermoelectric elements 33 use thermal effects for the generation of electric power by using the Seebeck effect. As known, the Seebeck effect is a thermoelectric effect wherein, in a circuit made up of metal conductors or semiconductors, a temperature difference generates a potential difference.

In the depicted example, there are two thermoelectric elements 33. In general, the thermoelectric elements 33 can be electrically connected in series or in parallel, according to the installation requirements in order to suitably adjust the voltage sent to the sensor unit 20.

In order to optimize the performance of the thermoelectric elements 33, they are laterally surrounded by a thermal insulant 34. The thermal insulant 34 allows minimizing thermal bridges between the hot side (at the plate 31) and the cold side (at the dissipator 32).

As mentioned, the plate 31 is preferably applied, directly or by interposing thermal conductors, onto the surface of the bow 12. In particular, the plate 31 is preferably in an inner position of the bow 12, opposite the aerial cable line as shown in Figure 1.

Furthermore, in order to minimize the aerodynamic impact of the thermoelectric generator 30, the protrusions or tabs of the dissipator 32 are preferably aligned with the direction of the air flow hitting the thermoelectric generator 30.

Figure 5 illustrates more in detail a non-limiting example of a sectional view of a sensor unit 20.

The sensor unit 20 preferably comprises a plastic box 21 which houses one or more electronic boards and the rechargeable battery. In this example, the sensor unit comprises a first electronic board 22a and a second electronic board 22b.

The sensor unit 20 preferably comprises an electric connection 23 for connecting the thermoelectric generator 30.

Figure 6 illustrates the first electronic board 22a of the sensor unit 20. In this example, the sensor unit 20 comprises a buffer battery 50, rechargeable in direct current by the thermoelectric generator 30.

As already described, the thermoelectric generator 30 has the function of recharging the battery 50 thus guaranteeing a long battery autonomy, by transforming the thermal energy collected by the bow 12 into electric energy.

Figure 7 illustrates the second electronic board 22b of the sensor unit 20.

The sensor unit 20 comprises at least one accelerometer 51, as already described. In addition, it is possible to adopt other sensors in addition to the accelerometer 51. For example, identification of the position of the pantograph 10 can be carried out by the accelerometer 51, in particular a MEMS accelerometer. The measure of the accelerometer 51 could be assisted by the detection of the intensity of the magnetic field around the aerial cable line, in particular by a magnetometer (not shown) to be mounted on the electronic board 22b.

Preferably, the sensor unit 20 further comprises a gyroscope 52 for measuring angular speeds and / or a temperature sensor (not shown) .

Preferably, the sensor unit 20 further comprises a microcontroller 53 configured to perform a pre-analysis of the measure of the pantograph 10 and/or of the aerial cable line. Preferably, the microcontroller is operatively associated with a memory 54.

Preferably, the sensor unit 20 further comprises an electric power management module 55 to selectively power the different elements of the sensor unit 20. In particular, the electric power management module 55 allows electric energy coming from the thermoelectric generator 30 to be suitably used to power different components which are present in the sensor unit 20. Preferably, in order to obtain enough autonomy of the battery 50 during operation, the electric power management module 55 uses energy harvesting techniques, that is, recovery of electric energy by the thermoelectric generator 30, and further energy saving logics for minimizing electrical consumptions.

In particular, as it will be further described, the sensor unit 20 as a whole is able to recognize when the pantograph 10 interacts with the aerial cable line and a continuous monitoring activity is therefore necessary or when the pantograph 10 is lowered and there is no need to acquire any data.

Preferably, the sensor unit 20 further comprises a wireless transmitter 56. In a non-limiting example, the wireless transmitter 56 implements a Bluetooth communication protocol. Preferably, the wireless transmitter 56 is configured to send information to a processing unit that is separated from the pantograph 10, for example placed on the rolling stock, that is, on board the train. Preferably, the wireless transmitter 56 can implement an existing protocol, such as “Bluetooth low energy”.

In general, the acceleration measures by the sensor unit 20 guarantee the monitoring of the pantograph 10 and of the catenary of the aerial cable line.

Preferably, the sensor unit 20 is always in a state of ultra-low power consumption in which it is the only active component and the accelerometer 51 is also in low-power mode. In these conditions, the consumption of the sensor unit 20 as a whole is minimal. When the accelerometer 51 detects an acceleration higher than a specific threshold, a trigger is sent to the microcontroller 53 which enables the entire sensor unit 20 to be activated in standard mode and to begin the acquisition of acceleration signals, which are useful for monitoring and diagnostic. The operating logic of the sensor unit 20 is based on monitoring needs, thus saving energy and guaranteeing a long autonomy to the sensor unit 20. When the pantograph 10 is detected interacting with the aerial cable line, the sensor unit 20 acquires the acceleration signals by the accelerometer 51. Preferably, a first pre-processing of the data on board the sensor unit 20 is performed by the microcontroller 53. The pre-processed data are therefore sent to the wireless transmitter 56 which sends them by a specific antenna to the further external unit (not shown) . On this external unit, such data can undergo a further processing, can be saved locally and/or loaded on a cloud storage for remote access.

Industrial applicability

The sensorized pantograph of the present invention integrates a wireless sensor system, which is energetically autonomous in monitoring activities by acceleration measures of the infrastructure and the same pantograph.

Considering the description reported herein, the person skilled in the art will be able to devise further modifications and variations, in order to satisfy contingent and specific needs.

For example, the sensor unit and the thermoelectric generator can be more or less close to each other, to the point of even constituting a single integrated device.

Therefore, the embodiments described herein are to be understood as illustrative and non-limiting examples of the invention.

Claims

1. Sensorized pantograph comprising:

- at least one raising arm (11);

- a bow (12) on top of said at least one raising arm (11), said bow (12) configured to provide an electric contact with an aerial cable line;

- a sensor unit (20) comprising at least one accelerometer (51), said sensor unit (20) configured for a measure of said pantograph (10) and/or of said aerial cable line, said sensor unit (20) comprising a wireless transmitter (56);

- a thermoelectric generator (30) on a surface of said bow (12), said thermoelectric generator (30) being configured to power said sensor unit (20).

2. Sensorized pantograph according to claim 1, wherein said thermoelectric generator (30) comprises:

- a plate (31) for application to said surface of said bow (12);

- a dissipator (32) with protrusions configured to increase a convective exchange;

- one or more thermoelectric elements (33) interposed between said plate (31) and said dissipator (32).

3. Sensorized pantograph according to claim 2, wherein said one or more thermoelectric elements (33) are laterally surrounded by a thermal insulant (34).

4. Sensorized pantograph according to claim 2 or 3, wherein said plate (31) is applied onto said surface of said bow (12) in an internal position, opposite said aerial cable line.

5. Sensorized pantograph according to any one of claims 1 to 4, wherein said sensor unit (20) is applied onto a surface of said bow (12) and comprises a cabled connection to said thermoelectric generator (30).

6. Sensorized pantograph according to any one of claims 1 to 5, wherein said sensor unit (20) further comprises a buffer battery (50), rechargeable in direct current by said thermoelectric generator (30).

7. Sensorized pantograph according to any one of claims 1 to 6, wherein said sensor unit (20) further comprises a gyroscope (52) and/or a temperature sensor.

8. Sensorized pantograph according to any one of claims 1 to 7, wherein said sensor unit (20) further comprises a microcontroller (53) configured to perform a pre-analysis of said measure of said pantograph (10) and/or of said aerial cable line.

9. Sensorized pantograph according to any one of claims 1 to 8, wherein said sensor unit (20) further comprises an electric power management module (55) to selectively power different elements of said sensor unit (20).

10. Sensorized pantograph according to any one of claims 1 to 9, wherein said wireless transmitter (56) is configured to send information to a processing unit that is separated from said pantograph (10).