WO2017007359A1

WO2017007359A1 - A technique for generating electric power from a rail joint gap

Info

Publication number: WO2017007359A1
Application number: PCT/RU2015/000420
Authority: WO
Inventors: Ivan Vladimirovich KOLCHIN
Original assignee: Siemens AG; Siemens Corp
Current assignee: Siemens AG; Siemens Corp
Priority date: 2015-07-06
Filing date: 2015-07-06
Publication date: 2017-01-12
Anticipated expiration: 2018-01-06

Abstract

A system and a method for generating electric power from a rail joint gap are provided. The technique includes an electric generator and an electric power receiving unit. The electric generator is positioned in the rail joint gap. The electric generator includes a contact surface configured to contact a wheel of a passing train and to receive mechanical energy from the wheel of the passing train. The electric generator is configured to produce electrical energy from the mechanical energy so received by the contact surface of the electric generator. The electric power receiving unit is electrically connected to the electric generator and configured to receive the electrical energy from electric generator.

Description

A technique for generating electric power from a rail joint gap

The present invention is related to electric power generation and more particularly to electric power generation from a rail joint gap. Present day railways are dependent on electric power.

Electric power is not just required to run the trains but also required to power several devices and equipments that form the part of the railway network for example traffic signals, communication equipments, different sensors placed beside the railroads, also referred to as railway tracks or rail tracks. These devices and equipments are physically dispersed throughout the rail track network and are required to be placed even in remotely located areas in the rail network. Powering these devices and equipments needs a large amount of energy.

Such devices and equipments are generally powered by electric power obtained from the main electric supply for electrified tracks i.e. those tracks which are well equipped with an electrification system such as overhead electrical power lines. However, powering such devices and equipments in those parts of the rail network which are non-electrified is a big challenge and solving it often requires setting up additional power supply lines extending to different remotely located rail tracks just to power these devices and equipments. This is an additional infrastructural burden on the rail network. Furthermore, there may also be such geographical terrains where even extension of such additional power supply lines may be infeasible or extremely cumbersome.

Thus, the object of the present technique is to generate power locally at the site of location of such devices and equipments. This will at least partially provide electric power for such devices and equipments and thus reduce the burden on the main power supply lines. Furthermore, in non- electrified parts of a rail network, the present technique will at least partly obviate the requirement of setting up additional power supply lines and thus reduce the

infrastructural burden on the rail network.

The above objects are achieved by a system for generating electric power from a rail joint gap according to claim 1 and by a method for generating electric power from a rail joint gap according to claim 11 of the present technique.

Advantageous embodiments of the present technique are

provided in dependent claims. Features of claim 1 may be combined with features of dependent claims, and features of dependent claims can be combined together. Similarly, features of claim 11 may be combined with features of

dependent claims, and features of dependent claims can be combined together.

According to an aspect of the present technique, a system for generating electric power from a rail joint gap is provided.

The system includes an electric generator and an electric power receiving unit. The electric generator is positioned in the rail joint gap. The electric generator includes a contact surface configured to contact a wheel of a passing train and to receive mechanical energy from the wheel of the passing train. The electric generator is configured to produce electrical energy from the mechanical energy so received by the contact surface of the electric generator. The electric power receiving unit is electrically connected to the

electric generator and configured to receive the electrical energy from electric generator.

Thus, the electric power is generated from the mechanical energy by using the electric generator. It is important to note that the electric generator in the system is such that the wheel of the passing train comes in direct contact with the electric generator at the contact surface of the electric generator. As a result of the direct contact between the electric generator and the wheel of the passing train, the mechanical energy from the wheel of the passing train is received directly by the electric generator and thus more mechanical energy is available to the electric generator compared to a technique wherein the wheel of the passing train does not come in direct contact of the electric

generator. Since all the mechanical energy available to the electric generator comes from the wheel of the passing train, the direct contact between the electric generator and the wheel of the passing train ensures that the present system is more energy efficient. No mechanical energy from the wheel of the passing train is lost in bringing the mechanical energy from the wheel of the passing train to the electric generator as a result of the direct physical contact between the electric generator and the wheel of the passing train.

Furthermore, the energy so generated from the rail joints may be used to store for future use or may be directly used to power equipments situated along the railroad. In an embodiment of the system, the electric generator includes a base material with a three dimensional structure and the electrical transducer is embedded in the three dimensional (3D) structure of the base material. The 3D structure physically protects the electrical transducer. The 3D structure may also help to maintain the electrical

transducer in a desired orientation with respect to the rail joint gap. Furthermore, the base material may be flexible and/or elastic and thus the electrical transducer is

protected from any changes in shape or length of adjoining rails forming the rail joint gap.

In another embodiment of the system, at least a part of the contact surface is a surface of the three dimensional

structure. In a related embodiment the contact surface is entirely formed of the surface of the three dimensional structure. Thus the wheel of the passing train come in direct physical contact with the base material and the mechanical energy from the wheel of the passing train is transferred to the electrical transducer via the base material . This protects the electrical transducer from wear and tear resulting from direct contact with the wheels of the passing train.

In another embodiment of the system, at least a part of the contact surface is a surface of the electrical transducer. In a related embodiment the contact surface is entirely formed of the surface of the electrical transducer. Thus the wheel of the passing train come in direct physical contact with electrical transducer and the mechanical energy from the wheel of the passing train is transferred to the electrical transducer directly. This ensures no mechanical energy is lost when passed from the wheels of the passing train to the electrical transducer.

In another embodiment of the system, the electrical

transducer is a piezoelectric transducer configured to produce the electrical energy by piezoelectric effect. This provides a simple way of implementing the present system. The mechanical stress and/or the impact resulting in the

piezoelectric transducer from the wheels of the passing train moving over the rail joint gap is used to generate the electrical energy.

In another embodiment of the system, the electrical

transducer is a magnetostrictive transducer configured to produce the electrical energy by magnetostrictive effect. This provides a simple way of implementing the present system. The mechanical stress and/or the mechanical

vibrations resulting in the magnetostrictive transducer from the wheels of the passing train moving over the rail joint gap is used to generate the electrical energy. In another embodiment of the system, the electrical

transducer is a triboelectric transducer configured to produce the electrical energy by triboelectric effect. This provides a simple way of implementing the present system. The mechanical energy in the triboelectric transducer resulting from the frictive contact between the wheels of the passing train moving over the rail joint gap and the contact surface is used to generate the electrical energy.

In another embodiment of the system, the electrical

transducer is an electromagnetic transducer configured to produce the electrical energy by electromagnetic effect. This provides a simple way of implementing the present system. The mechanical energy in the electromagnetic transducer resulting from the electromagnetic effect of the wheels of the passing train moving over the rail joint gap and the contact surface is used to generate the electrical energy. In another embodiment of the system, the electric power receiving unit is configured to provide the electrical energy to a power consuming device configured to consume the

electrical energy so provided. Thus, the electric power receiving unit may receive the electrical energy from one or more of the electrical transducers and provide the electrical energy so received to a power consuming device that may be located at the side of the rail tracks. Example of such power consuming device may be a signal light. The electric power receiving unit before providing the electrical energy to the external power consuming device may condition the electrical energy for example step up or down the voltage or change the strength of the electric power to be provided. Thus such external power consuming devices along the railroad or the rail tracks may be supplied with the electrical energy generated from the rail joint gaps and thus completely or at least partially fulfilling the power needs of such external power consuming devices .

In another embodiment of the system, the electric power receiving unit is an electrical energy storing unit. Thus the electrical energy may be stored and used at a future point of time . According to another aspect of the present technique, a method for generating electric power from a rail joint gap is provided. In the method an electric generator is positioned in the rail joint gap. The electric generator includes a contact surface and an electrical transducer. The contact surface is configured to contact a wheel of a passing train and to receive mechanical energy from the wheel of the passing train. The electrical transducer is configured to produce electrical energy from the mechanical energy so received by the contact surface of the electric generator. In the method, an electric power receiving unit is electrically connected to the electric generator. The electric power receiving unit receives the electrical energy from the electric generator.

Thus, in the present method, the electric power is generated from the mechanical energy by using the electric generator. It is important to note that in the method the wheel of the passing train comes in direct contact with the electric generator at the contact surface of the electric generator. As a result of the direct contact between the electric generator and the wheel of the passing train, the mechanical energy from the wheel of the passing train is received directly by the electric generator and thus more mechanical energy is available to the electric generator compared to a technique wherein the wheel of the passing train does not come in direct contact of the electric generator. Since all the mechanical energy available to the electric generator comes from the wheel of the passing train, the direct contact between the electric generator and the wheel of the passing train ensures that the present method is more energy

efficient. No mechanical energy from the wheel of the passing train is lost in bringing the mechanical energy from the wheel of the passing train to the electric generator as a result of the direct physical contact between the electric generator and the wheel of the passing train. In an embodiment of the method, the electric generator comprises a base material with a three dimensional (3D) structure and wherein the electrical transducer is embedded in the three dimensional structure of the base material. The 3D structure physically protects the electrical transducer. The 3D structure may also help to maintain the electrical transducer in a desired orientation with respect to the rail joint gap. Furthermore, the base material may be flexible and/or elastic and thus the electrical transducer is

In another embodiment of the method, at least a part of the contact surface is a surface of the three dimensional structure. In a related embodiment the contact surface is entirely formed of the surface of the three dimensional structure. Thus, in the method, the wheel of the passing train come in direct physical contact with the base material and the mechanical energy from the wheel of the passing train is transferred to the electrical transducer via the base material. This protects the electrical transducer from wear and tear resulting from direct contact with the wheels of the passing train. In another embodiment of the method, at least a part of the contact surface is a surface of the electrical transducer. In a related embodiment of the method the contact surface is entirely formed of the surface of the electrical transducer. Thus, in the method, the wheel of the passing train comes in direct physical contact with electrical transducer and the mechanical energy from the wheel of the passing train is transferred to the electrical transducer directly. This ensures no mechanical energy is lost when passed from the wheels of the passing train to the electrical transducer. In another embodiment of the method, the electrical

transducer is a piezoelectric transducer configured to produce the electrical energy by piezoelectric effect. Thus in the method, the mechanical stress and/or the impact resulting in the piezoelectric transducer from the wheels of the passing train moving over the rail joint gap is used to generate the electrical energy. In another embodiment of the method, the electrical

transducer is a magnetostrictive transducer configured to produce the electrical energy by magnetostrictive effect. Thus in the method, the mechanical stress and/or the

mechanical vibrations resulting in the magnetostrictive transducer from the wheels of the passing train moving over the rail joint gap is used to generate the electrical energy.

In another embodiment of the method, the electrical

transducer is a triboelectric transducer configured to produce the electrical energy by triboelectric effect. Thus in the method, the mechanical energy in the triboelectric transducer resulting from the frictive contact between the wheels of the passing train moving over the rail joint gap and the contact surface is used to generate the electrical energy.

In another embodiment of the method, the electrical

transducer is an electromagnetic transducer configured to produce the electrical power by electromagnetic effect. Thus in the method, the mechanical energy in the electromagnetic transducer resulting from the electromagnetic effect of the wheels of the passing train moving over the rail joint gap and the contact surface is used to generate the electrical energy.

In another embodiment of the method, the electric power receiving unit provides the electrical energy to a power consuming device configured to consume the electrical energy so provided. Thus, the electric power receiving unit may receive the electrical energy from one or more of the

electrical transducers and provide the electrical energy so received to a power consuming device that may be located at the side of the rail tracks. Example of such power consuming device may be a signal light. The electric power receiving unit before providing the electrical energy to the external power consuming device may condition the electrical energy for example step up or down the voltage or change the

strength of the electric power to be provided. Thus such external power consuming devices along the railroad or the rail tracks may be supplied with the electrical energy generated from the rail joint gaps and thus completely or at least partially fulfilling the power needs of such external power consuming devices.

In another embodiment of the method, the electric power receiving unit is an electrical energy storing unit and wherein the method further comprises storing the electrical power so received in the electrical energy storing unit. Thus in the method, the electrical energy is stored for use at a future point of time.

The present technique is further described hereinafter with reference to illustrated embodiments shown in the

accompanying drawing, in which:

FIG 1 schematically illustrates side view of a rail track with a rail gap joint and a system for generating electric power from the rail joint gap,

FIG 2 schematically illustrates zoomed in side view

the rail track with the rail gap joint and the system for generating electric power from the joint gap shown in FIG 1,'

FIG 3 schematically illustrates side view of an exemplary embodiment of the system for generating electric power from the rail joint gap,

FIG 4 schematically illustrates top view of the exemplary embodiment of the system shown in FIG 3, schematically illustrates side view of another exemplary embodiment of the system for generating electric power from the rail joint gap, schematically illustrates top view of the exemplary embodiment of the system shown in FIG 5, schematically illustrates side view of a rail track with a rail gap joint, schematically illustrates top view of the rail track with the rail gap joint, and illustrates a flow chart representing a method for generating electric power from the rail joint gap, in accordance with aspects of the present technique .

Hereinafter, above-mentioned and other features of the present technique are described in details. Various

embodiments are described with reference to the drawing, wherein like reference numerals are used to refer to like elements throughout. In the following description, for purpose of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more embodiments. It may be noted that the illustrated embodiments are intended to explain, and not to limit the invention. It may be evident that such embodiments may be practiced without these specific details.

The present technique involves generating electrical energy from the joints in rail tracks. Such joints are between lengths of rails and serve to form a long uninterrupted stretch of rails from shorter preformed lengths of rails. Such joints are commonly found in jointed rail tracks and sometimes also present in continuous welded rail tracks. The idea of the present technique is to generate electric power or electrical energy at these joints which may then be provided to various devices and equipments, such as traffic signals, communication devices, etc present along the track, preferably in vicinity of the joints. Example of such joints is illustrated in FIGs 7 and 8. FIG 7 schematically illustrates side view of a rail track with a rail gap joint 10, and FIG 8 schematically illustrates top view of the rail track with the rail gap joint 10. As can be seen two adjacent lengths of rails, also called as rail bars or rail beams 12 and 16 are laid side by side on rail supports 26 (also called as sleepers or ties) to form a continuous stretch of the rail track. The rail gap joint 10 (hereinafter referred to as the joint 10) is between an end of the rail beam 12 and an end of the rail beam 16. To keep the rail beams 12, 16 or rail bars 12, 16 aligned with each other, the rail bars 12, 16 are usually fastened or fixed together for example by bolting together using one or more perforated steel plate known as fishplate 20 or joint bars. Fishplate fasteners 22 are usually bolts that connect the fishplate 20 to the adjacent rail beams 12, 16, as shown in the FIGs 7 and 8. Usually the fishplate 20 remains clear of heads 13, 17 of the rail beams 12, 16 and are present in a region called as a web (not shown) of the rail beams 12, 16. FIGs 7 and 8 also depict top surfaces 14 and 18 of the rail beams 12 and 16, respectively. When a train passes on the rail beams 12, 16, wheels of the train are in contact with the top surfaces 14 and 18 of the rail beams 12 and 16. In accordance with aspects of the present technique, electrical energy or electric power is generated from one or more of the joints 10. Hereinafter the present technique is explained in details .

FIG 1 schematically illustrates side view of the rail track with the rail gap joint 10 and a system 1 for generating electric power from the rail joint gap 10. FIG 2

schematically illustrates zoomed in side view of the rail track with the rail gap joint 10 and the system 1 shown in FIG 1. The system 1 includes an electric generator 30 and an electric power receiving unit 40. The electric generator 30 is positioned in the rail joint gap 10. The electric

generator 30 includes a contact surface 36 (shown in FIG 2) and an electrical transducer (shown in FIG 3 and 4) . The electric transducer is a transducer that receives mechanical energy and converts the received mechanical energy to

electrical energy. The contact surface 36 is a part or a surface of the electric generator 30 which comes in contact with wheels 4, 6 when a train 2 passes over the rail track i.e. the rail beams 12, 16 and the joint 10. The electric generator 30 through contact with the wheel 4,6 of the passing train 2 receives mechanical energy from the wheel 4,6 of the passing train 2. The mechanical energy from the wheel 4,6 of the passing train 2 is transmitted via the contact surface 36 of the electric generator 30 to the electrical transducer of the electric generator 30. The mechanical energy so received by the contact surface 36 and thus by the electric transducer is converted to electric energy by the electric transducer of the electric generator 30.

The electric power receiving unit 40 is electrically

connected, for example by electrical connections 42

established via electrical cables, to the electric generator 30. The electric power receiving unit 40 receive the

electrical energy from the electric generator 30.

It may be noted that in the present technique the contact surface 36 of the electric generator 30 comes in direct contact with the wheels 4,6 of the passing train 2. In an exemplary embodiment, as depicted in FIG 1 and 2, the

electric generator 30 is positioned in the joint 10 such that at least a part of the contact surface 36 is leveled with the top surfaces 14, 18 of the heads 13, 17 of the rails 12, 16. In another exemplary embodiment of the system 1, the electric generator 30 is positioned in the joint 10 such that at least a part of the electric generator 30 including the contact surface 36 protrudes beyond a level of the top surfaces 14, 18 of the heads 13, 17 of the rails 12, 16. Thus the contact surface 36 is either at same level as a top surface 24 of the joint 10 or protrudes beyond top surface 24 of the joint 10. It may be noted that the top surface 24 of the joint 10 is basically an imaginary surface which would have formed if the top surfaces 14, 18 of the heads 13, 17 of the rails 12, 16 were extended regularly to form a continuous surface. Thus when the wheels 4, 6 pass over the contact surface 36 of the electric generator, mechanical energy from the wheels , 6 is passed on to the electric generator 30 by direct physical contact between the wheels 4, 6 and the contact surface 36 of the electric generator 30. When the electric generator 30 is aligned perpendicular to the surfaces 14, 18 of the heads 13, 17 of the rails 12, 16, then the mechanical energy resulting from movement of the wheels 4, 6 over the contact surface 36 is transmitted in an axis perpendicular to the surfaces 14, 18. The axis is depicted in FIG 2 with an arrow with

reference numeral 34.

In an exemplary embodiment of the system 1, the electric power receiving unit 40 is configured to provide the

electrical energy received by it from the electric generator 30 to a power consuming device 60. This may be achieved in a variety of ways for example by electrically connecting directly the electric power receiving unit 40 to the power consuming device 60. Although in the present technique, only one electric generator 30 is depicted, it may be appreciated by one skilled in the art that it is well within the scope of present technique that several such electric generators 30 may be positioned or seated within one or more of joints 10 and may feed electric energy generated by them to one or more of the electric power receiving unit 40. Thus, the electric power receiving unit 40 may receive the electrical energy from one or more of the electric generators 30 and provide the electrical energy so received to one or more of the power consuming devices 60. The power consuming devices 60 may be located at sides of the rail track i.e. at side of or along the rail bars 12, 16 and the joint 10. Example of such power consuming device 60 may be a traffic signal light, communication devices, battery units, different sensors, and so on and so forth.

In an exemplary embodiment of the system 1, the electric power receiving unit 40 provides the electrical energy to the external power consuming device 60 directly without altering any characteristic of the electric energy, whereas in an alternate exemplary embodiment of the system 1, the electric power receiving unit 40 before providing the electrical energy to the external power consuming device 60 may

condition the electrical energy, for example step up or down the voltage or change the strength of the electric power to provided to the power consuming device 60. In another exemplary embodiment of the system 1, the electric power receiving unit 40 is an electrical energy storing unit for example a battery unit. The electrical energy storing unit 40 stores the electrical energy which may be used at a future point in time.

The present technique has been further explained with help of FIGs 3 and 5 in combination with FIGs 4 and 6. FIG 3 and FIG 4 schematically illustrate side view and top view,

respectively, of an exemplary embodiment of the system 1 positioned in the rail joint gap 10. Similarly, FIG 5 and FIG 6 schematically illustrate side view and top view,

respectively, of another exemplary embodiment of the system 1 positioned in the rail joint gap 10. In FIGs 3 and 5, the electrical transducer is depicted with reference numeral 32. Furthermore, in an exemplary embodiment of the system 1, as depicted in FIGs 3 to 6, the electric generator 30 includes a base material 50 formed in a three dimensional (3D) structure 52. The 3D structure 52 is

corresponding to a structure or form or volume of the joint 10 and may be in a shape of, but not limited to, rectangular parallelepiped, cylinder, cone, cuboid, etc. The electrical transducer 32 is embedded in the three dimensional structure 52 of the base material 50. FIGs 3 and 5 schematically depict different exemplary types of embedding of the electrical transducer 32 in the base material 50. In exemplary

embodiment of FIG 3, the electrical transducer 32 is embedded such that no part of the electrical transducer 32 forms a part of the contact surface 36 whereas in exemplary

embodiment of FIG 5, the electrical transducer 32 is embedded such that at least a part of the electrical transducer 32 forms a part of the contact surface 36.

Furthermore, in an exemplary embodiment as seen in FIG 4, at least a part 37 of the contact surface 36 is a surface 54 of the three dimensional structure 52. Whereas in another exemplary embodiment as seen in FIG 6, at least a part 38 of the contact surface 36 is a surface 33 of the electrical transducer 32. The base material 50 may be a flexible and/or elastic and may be manufactured from an alloy, a polymer or resin, etc. The electric transducer 32 may be based on a variety of electromechanical techniques, for example, the electrical transducer 32, may be, but not limited to, a piezoelectric transducer, a magnetostrictive transducer, a triboelectric transducer, an electromagnetic transducer.

The piezoelectric transducer, for example a transducer based on Lead zirconate titanate, also known as PZT, is configured to produce the electrical energy by piezoelectric effect. Similarly, the magnetostrictive transducer, the triboelectric transducer and the electromagnetic transducer produce

electrical energy from mechanical energy by magnetostrictive effect, triboelectric effect and electromagnetic effect, respectively. These transducers and the associated effects to produce electrical energy from mechanical energy are well known in the science of electromechanical sciences and thus have not been described herein in details for sake of

brevity. Referring to FIG 9, in combination with FIGs 1 to 8 , a flow chart representing a method 100 for generating electric power from the rail joint gap 10, in accordance with aspects of the present technique, is illustrated. The method uses a system 1 as described in reference to FIGs 1 to 8. In the method 100, the electric generator 30 is positioned in the rail joint gap 10 in a step 110. The electric generator includes the contact surface and the electrical transducer as described in

reference to FIGs 1 to 8. When the train 2 is passing over the joint 10 with the system 1, at different instances of time during the passage of the train 2 over the joint 10, the contact surface 36 comes in direct physical contact with different wheels 4, 6 of the passing train 2 and thus

receives mechanical energy from the wheel 4, 6 of the passing train 2. The electrical transducer 32 then receives this mechanical energy from the contact surface 36 and converts the mechanical energy so received into electrical energy. In the method 100, the electric power receiving unit 40 is electrically connected to the electric generator 30 in a step 120. The electric power receiving unit 40 thus receives the electrical energy from the electric generator 30. The

electrical energy then is provided to the power consuming devices 60 in a step 130. Optionally, in a step 140 the electrical energy is stored in the electrical energy storing unit 40 such as a battery and may be later provided to power consuming devices 60 as described in the step 130.

While the present technique has been described in detail with reference to certain embodiments, it should be appreciated that the present technique is not limited to those precise embodiments. Rather, in view of the present disclosure which describes exemplary modes for practicing the invention, many modifications and variations would present themselves, to those skilled in the art without departing from the scope and spirit of this invention. The scope of the invention is, therefore, indicated by the following claims rather than by the foregoing description. All changes, modifications, and variations coming within the meaning and range of equivalency of the claims are to be considered within their scope.

Claims

Patent claims

1. A system (1) for generating electric power from a rail joint gap (10) , the system (1) comprising:

- an electric generator (30) positioned in the rail joint gap (10) , the electric generator (30) comprising a contact surface (36) and an electrical transducer (32) , wherein the contact surface (36) is configured to contact a wheel (4,6) of a passing train (2) and to receive mechanical energy from the wheel (4,6) of the passing train (2), and wherein the electrical transducer (32) is configured to produce

electrical energy from the mechanical energy so received by the contact surface (36) of the electric generator (30) , and - an electric power receiving unit (40) electrically

connected to the electric generator (30) and configured to receive the electrical energy from the electric generator (30) .

2. The system (1) according to claim 1, wherein the electric generator (30) comprises a base material (50) with a three dimensional structure (52) and wherein the electrical transducer (32) is embedded in the three dimensional

structure (52) of the base material (50) .

3. The system (1) according to claim 2, wherein at least a part (37) of the contact surface (36) is a surface (54) of the three dimensional structure (52) .

4. The system (1) according to any one of claims 1 to 3, wherein at least a part (38) of the contact surface (36) is a surface (33) of the electrical transducer (32) .

5. The system (1) according to any one of claims 1 to 4 , wherein the electrical transducer (32) is a piezoelectric transducer configured to produce the electrical energy by piezoelectric effect.

6. The system (1) according to any one of claims 1 to 4, wherein the electrical transducer (32) is a magnetostrictive transducer configured to produce the electrical energy by magnetostrictive effect.

7. The system (1) according to any one of claims 1 to 4, wherein the electrical transducer (32) is a triboelectric transducer configured to produce the electrical energy by triboelectric effect.

8. The system (1) according to any one of claims 1 to 4, wherein the electrical transducer (32) is an electromagnetic transducer configured to produce the electrical energy by electromagnetic effect.

9. The system (1) according to any one of claims 1 to 8, wherein the electric power receiving unit (40) is configured to provide the electrical energy to a power consuming device (60) configured to consume the electrical energy so provided.

10. The system (1) according to any one of claims 1 to 9, wherein the electric power receiving unit (40) is an

electrical energy storing unit.

11. A method (100) for generating electric power from a rail joint gap (10) , the method (100) comprising:

- positioning (110) an electric generator (30) in the rail joint gap (10) , the electric generator (30) comprising a contact surface (36) and an electrical transducer (32) , wherein the contact surface (36) is configured to contact a wheel (4,6) of a passing train (2) and to receive mechanical energy from the wheel (4,6) of the passing train (2), and wherein the electrical transducer (32) is configured to produce electrical energy from the mechanical energy so received by the contact surface (36) of the electric

generator (30) , and

- electrically connecting (120) an electric power receiving unit (40) to the electric generator (30) , wherein the electric power receiving unit (40) receives the electrical energy from the electric generator (30) .

12. The method (100) according to claims 11, wherein the electric generator (30) comprises a base material (50) with a three dimensional structure (52) and wherein the electrical transducer (32) is embedded in the three dimensional

structure (52) of the base material (50) .

13. The method (100) according to claim 12, wherein at least a part (37) of the contact surface (36) is a surface (54) of the three dimensional structure (52) .

14. The method (100) according to any one of claims 11 to 13, wherein at least a part (38) of the contact surface (36) is a surface (33) of the electrical transducer (32) .

15. The method (100) according to any one of claims 11 to 14, wherein the electrical transducer (32) is a piezoelectric transducer configured to produce the electrical energy by piezoelectric effect.

16. The method (100) according to any one of claims 11 to 14, wherein the electrical transducer (32) is a magnetostrictive transducer configured to produce the electrical energy by magnetostrictive effect.

17. The method (100) according to any one of claims 11 to 14, wherein the electrical transducer (32) is a triboelectric transducer configured to produce the electrical energy by triboelectric effect.

18. The method (100) according to any one of claims 11 to 14, wherein the electrical transducer (32) is an electromagnetic transducer configured to produce the electrical energy by electromagnetic effect.

19. The method (100) according to any one of claims 11 to 18, wherein the electric power receiving unit (40) provides (140) the electrical energy to a power consuming device (60) configured to consume the electrical energy so provided.

20. The method (100) according to any one of claims 11 to 19, wherein the electric power receiving unit (40) is an

electrical energy storing unit and wherein the method (100) further comprises storing (130) the electrical energy so received in the electrical energy storing unit.