POTENTIAL FREE POSITION MONITORING FOR HIGH VOLTAGE SWITCH

Abstract

 A high voltage switch (10) comprises a movable electric contact (12) movable with respect to a further electric contact (14) between a closed position, in which the electric contacts (12, 14) are connected and an opened position, in which the electric contacts (12, 14) are disconnected, and a position sensor (24) for determining a position (64) of the movable electric contact (12). The position sensor (24) comprises a sensor bar (30) with a light emitting side (46) and a light receiving side (48); a code strip (28) comprising a transparent pattern (60), wherein the code strip (28) is arranged between the light emitting side (46) and the light receiving side (48); an electric sensor part (27) comprising a light source (40) and at least one light receiver (42) for converting a light signal into an electric signal; and fibre optics lines (32, 34) for connecting the light source (40) with the light emitting side (46) and for connecting the light receiving side (48) with the at least one light receiver (42). The code strip (28) and the sensor bar (30) are attached to the high voltage switch (10) such that a movement of the movable electrical contact (12) is conveyed in a relative movement of the code strip (28) and the sensor bar (30).

Description

FIELD OF THE INVENTION

[0001] The invention relates to a high voltage switch.

BACKGROUND OF THE INVENTION

[0002] High voltage switches, such as high voltage circuit breakers and disconnectors, usually do not have a distance measurement, which is used for determining the position of the electric contacts. Usually, only additionally contacts are used for the end positions of the movement of the electric contacts, which are used for high voltage switching.

[0003] A use of electric position and/or distance measurement devices, which are linked to the electric contacts of the high voltage switch, is challenging. The transmission of electrical signals from within the pressurized enclosures of the high voltage switch to the outside in a gas insulated switchgear may be complicated. The electric signal has to be unaffected by transient electrical fields and it must be delivered to the outside by a feed-through without causing any gas leakage.

[0004] For example, an electronic distance measurement sensor may be attached close to the moving parts inside of the high voltage switch. Such a sensor usually needs a power supply and cables which then need a feed through to the housing of the high voltage switch. Furthermore, the sensor then may be fully exposed to the electric fields inside the high voltage switch and may have to be protected from them.

[0005] Alternatively, it is possible to use a laser beam triangulation to determine the distance of the moving parts. The laser emitting and receiving device may be mounted outside the housing and may measure through a translucent cover, which has to be provided in the housing. It also may be possible to install the laser emitting and receiving device inside of the housing. However, the electronics of the laser emitting and receiving device then may be exposed to high electric fields and a gas tight feed through for cables may be necessary.

[0006] CN 103618387 A relates to sensing open and closed positions of high-voltage switch equipment. An open/closed position sensor is connected with a rotating shaft of an operating mechanism of the high-voltage switch equipment.

[0007] EP 0 027 774 A1 shows an optical position sensor with a code plate having an optical code mask. The code mask has a series of transparent areas arranged in rows for encoding bits of a signal that may be generated with beam of lights shining through the code plate.

DESCRIPTION OF THE INVENTION

[0008] It is an objective of the invention to determine the position of an electric contact of a high voltage switch in an easy and reliable way.

[0009] This objective is achieved by the subject-matter of the independent claims. Further exemplary embodiments are evident from the dependent claims and the following description.

[0010] The invention relates to a high voltage switch. In this context, a high voltage may be a voltage with a nominal voltage level of more than 1 kV, such as 10 KV, 50 kV or 100 kV. The voltage may be an AC or DC voltage. For example, the high voltage switch may be a circuit breaker or a disconnector, which may be used in a power station and/or a transformer substation.

[0011] According to an embodiment of the invention, the high voltage switch comprises a movable electric contact movable with respect to a further electric contact between a closed position, in which the electric contacts are electrically connected and an opened position, in which the electric contacts are electrically disconnected and a position sensor for determining a position of the movable electric contact. It may be that the movable electric contact is moved by an actuator of the high voltage switch.

[0012] It may be that the further electric contact is also a movable electric contact that is movable by a further actuator. In this case, the further electric contact also may comprise a position sensor.

[0013] According to an embodiment of the invention, the position sensor comprises a sensor bar with a light emitting side and a light receiving side; a code strip comprising a transparent pattern, wherein the code strip is arranged between the light emitting side and the light receiving side; an electric sensor part comprising a light source and at least one light receiver for converting a light signal into an electric signal; and fibre optics lines for connecting the light source with the light emitting side and for connecting the light receiving side with the at least one light receiver.

[0014] The code strip and the sensor bar are attached to the high voltage switch such that a movement of the movable electrical contact is conveyed in a relative movement of the code strip and the sensor bar. For example, the code strip may be connected to the movable electric contact and the sensor bar may be connected to a non-moving part of the high voltage switch, or vice versa.

[0015] The electric sensor part may generate light with the light source, which is conducted to the sensor bar through a fibre optics line. There, the light from the light emitting side is either shielded by the code strip or shines through the transparent pattern onto the light receiving side. From the light receiving side, the light is conducted by a further fibre optics line to a light receiver, which is adapted for discriminating between a light level, when the light is shielded and a light level, when the light is shining through the code strip. All fibre optics lines may comprise glass fibres.

[0016] The electric sensor part may be arranged remote from the sensor bar and the code strip and/or remote from a place, where high voltages and/or electromagnetic fields may be present. The sensor bar and the code strip as well as the fibre optics line may not be disturbed by the high voltages and/or electromagnetic fields, since they may comprise no electric components.

[0017] The optical connection by the fibre optics lines may be chosen long enough to place the electric sensor part far enough away from a zone endangered with electromagnetic disturbances. With the fibre optics line, a potential free feedthrough from the moving parts to the electric sensor part may be provided. No expansive shielding of electric components may be necessary.

[0018] According to an embodiment of the invention, the light emitting side of the sensor bar comprises a row of light emitting spots, each of which is connected to a fibre optics line. Also, the light receiving side of the sensor bar comprises a row of light receiving spots, each of which is connected to a fibre optics line. Each of the light emitting side and the light receiving side may be mounts for the ends of the fibre optics lines, either from the electric sensor part to the sensor bar or from the sensor bar back to the electric sensor part.

[0019] The fibre optics line from the electric sensor part to the sensor bar may be connected to a light source of the electric sensor part. Each of the fibre optics lines from the sensor bar back to the electric sensor part may be connected to a light receiver for each of the light receiving spots.

[0020] For example, each of the light emitting spots and/or the light receiving spots may comprise a lens. Inside of the sensor bar, one light emitting spot of the light emitting side may be focused by a lens to form a light beam and then may shine through the code strip. On the light receiving side, the light beam may be focused by a second lens of the corresponding light receiving spot to bring the beam back into the receiving fibre optics line.

[0021] It also may be possible that the sensor bar comprises only one light emitting spot and one light receiving spot. In this case, only the end positions of the electric contact and an intermediate position may be encoded with the code strip. However, also an acceleration and/or speed may be determined with an alternating transparent pattern.

[0022] According to an embodiment of the invention, the row of light emitting spots and the row of light receiving spots are aligned orthogonal to a movement direction of the code strip. In such a way, it is possible to encode more than two positions with the code strip. In this case, the transparent pattern may be formed that at specific positions it shields specific combinations of light emitting spots from the light receiving spots. With these combinations, several positions may be encoded.

[0023] According to an embodiment of the invention, the transparent pattern of the code strip is formed, such that it encodes a bit code for a position of the code strip, where the transparent pattern shields light emitting spots of the light emitting side from light receiving spots of the light receiving side of the sensor bar. The part of the code strip comprising the transparent pattern may be divided into rows. These code strip rows may be orthogonal to the rows of light emitting spots and light receiving spots and/or may be parallel to the movement direction of the code strip. Each of the code strip rows may encode a bit for each position, either by shielding the light from the light emitting spot, when no transparent area of the transparent pattern is present or by not shielding the light due to a transparent area.

[0024] With n rows, it is possible to determine 2ⁿ positions of the travel distance of the code strip and/or the electric contact. n also may be the number of light emitting spots and/or light receiving spots and/or light receivers in the electric sensor part. It may be that due to redundancy reasons, these numbers may be different from each other and/or from the number of code strip rows.

[0025] It may be that the code encoding only 0 is not used, to make sure that there is no position with all lights off. This may be done to guarantee that at least one light path is open, because no light at all may not show, if the position sensor is working or has an error. The subtraction of one reduces the possible 2ⁿ positions to 2ⁿ-1 positions.

[0026] For example, the size of the transparent pattern in the moving distance may be divided by possible positions p=2ⁿ-1. The points of signal changes may be distributed equally or non-equally, for example depending on the desired positions, which have to be discriminated.

[0027] As an example, the code strip may comprise 3 rows and the position sensor may comprise three channels. A channel may be the combination of a fibre optics line, a light emitting spot, a code strip row, a light receiving spot, a further fibre optics line and a light receiver, which may evaluate the bit of the channel. In the case of n=3 code strip rows and/or channels, p=7 different positions may be discriminated.

[0028] It further may be that the transparent pattern encodes the positions with a gray code, i.e. with a code for that only one bit changes between neighboring positions.

[0029] According to an embodiment of the invention, the code strip has a first transparent pattern for the sensor bar and an equal second transparent pattern for a second sensor bar. The two transparent patterns may encode the same positions with the same codes. Furthermore, there may be first channels for the first transparent pattern and different second channels for the second transparent pattern. This may provide redundancy with two independently working subsystems of the position sensor.

[0030] In general, a redundant setup may be provided by multiplying the number of sensor channels.

[0031] According to an embodiment of the invention, the second transparent pattern and the second sensor bar are spaced apart from the first transparent pattern and the first sensor bar in a movement direction of the code strip. The first and second sensor bar may have a distance equal to a repeating distance of the transparent patterns. In such a way, the signals of the sensor bars may be compared directly. If the signals of the first bar are different from the ones of the second sensor bar, it may be assumed that the position sensor has an error.

[0032] However, alternatively and/or additionally, it also may be possible that the first and second transparent patterns are spaced apart from each other in a direction orthogonal to the movement direction.

[0033] The electrically non-conducting connection of the sensor bar(s) with the electric sensor part may be used for electrically isolating the parts of the sensor near the electric contact and/or the actuator from the electric sensor part. The parts of the position sensor may be on different potentials. It has to be noted that the potentials may differ by more than 10 kV, for example.

[0034] According to an embodiment of the invention, the sensor bar and/or the code strip are on the same electric potential as the movable electric contact. These parts may be directly connected without electrical isolation to the electric contact, the actuator and/or further parts of the high voltage switch on potential.

[0035] According to an embodiment of the invention, the electric sensor part is arranged at a position having a different electric potential as the movable electric contact. For example, the electric sensor part may be arranged remote from the electric contacts and/or the actuator.

[0036] According to an embodiment of the invention, at least some of the fibre optics lines are guided between different electric potentials. As already mentioned, the separation of the potentials may be achieved with the fibre optics lines, which may be made of electrically isolating material.

[0037] In general, the high voltage switch may be available as dead tank (with housing on ground potential) and life tank (with housing on electric contact potential). The position sensor may be used in both design without modifications.

[0038] According to an embodiment of the invention, the high voltage switch comprises a housing, in which the electric contacts are arranged. The housing may provide a switching chamber, in which switching of the high voltage switch takes place. The housing may be on ground potential or on potential of the electric contacts. Also, the code strip and the sensor bar of the position sensor are arranged inside the housing.

[0039] According to an embodiment of the invention, an isolating gas is provided inside the housing. For example, the housing may be filled with SF6. The electric contacts as well as the parts of the position sensor inside the housing, such as the sensor bar, the code strip and parts of the fibre optics lines may be exposed to the isolating gas. In general, the position sensor may be arranged inside of a SF6 gas room and/or the position measurement take place in such as gas room.

[0040] According to an embodiment of the invention, the electric sensor part is arranged outside of the housing. For example, the electric sensor part may be attached to the outside of the housing. All parts of the position sensor inside the housing may be pure optical parts. There may be no electric and/or electronic parts inside the switching chamber. By placing the electric sensor part, and in particular the light source, the one or more light receivers and optionally a controller for evaluating the signal(s) of the light receiver(s) outside the housing, the electric system of the position sensor may not be exposed to electrical fields from the switching chamber.

[0041] According to an embodiment of the invention, the fibre optics lines are guided from an inside of the housing to an outside of the housing. The optical connections provided by the fibre optics lines may be chosen long enough to place the electric sensor part far enough away from an EMC (electromagnetic compatibility) endangered zone.

[0042] According to an embodiment of the invention, the code strip is rigidly connected to the movable electric contact. The code strip may move in the same way as the movable electric contact. It also may be that the code strip is directly connected to the moving part of the actuator, which moves the electric contact. It also may be possible that the code strip is connected via a gear with the electric contact and/or the actuator, which may translate a movement of a first distance of the electric contact into a different movement of a second distance of the code strip.

[0043] On the other hand, the one or more sensor bars may be connected to parts of the high voltage switch, which are not moved by the actuator.

[0044] According to an embodiment of the invention, the code strip is a metal strip. For example, the code strip is made of sheet metal.

[0045] According to an embodiment of the invention, the transparent pattern is composed of openings in the code strip. For example, the code strip may be a sheet metal with a coded hole pattern as transparent pattern.

[0046] According to an embodiment of the invention, the electric sensor part comprises a controller for evaluating one or more electric signals from the light receivers. The controller may determine the position, the speed and/or the acceleration of the code strip and optionally may determine the health state of the position sensor. All these information may be sent to a superordinated controller, such as one of a SCADA (Supervisory Control And Data Acquisition) system.

[0047] According to an embodiment of the invention, the controller is adapted for determining a position of the movable electric contact. Based on the shielded and transmitted light beams, the controller may determine a bit code. From the bit code, the controller may determine the actual position, for example based on a table stored in the controller.

[0048] According to an embodiment of the invention, the controller is adapted for determining a speed of the movable electric contact. When the controller additionally determines the time of transitions between different bit codes and/or the time duration, a specific bit code is present, the controller also may determine a speed of the electric contact. Here, also the distances between borders of the transparent pattern, where the positions change, may have to be known. These distances, whether they all are equal or whether there are different distances, also may be stored in the controller.

[0049] From the speed, also the acceleration of the electric contact may be determined.

[0050] Since the measurement of the optical parts of the position sensor is fast (at speed of light), it may be possible to switch the high voltage switch from the closed to the opened position (and/or vice versa) within 3 ms or less and to simultaneously monitor the switching position. The digital way-time information, such as position, speed and/or acceleration, generated by the position sensor may be used for generating switching commands for a semiconductor based breaker in less than 3 ms.

[0051] According to an embodiment of the invention, the high voltage switch comprises an actuator for moving the movable electric contact. For example, the actuator may be a Thomson coil, which may be adapted to switch the high voltage switch very fast, such as within the above mentioned 3 ms. However, such an actuator may generate high electric and magnetic fields, in particular inside a housing of the high voltage switch. For example, the switching coils of such an actuator may consume up to 12 kA current during switching. All parts of the position sensor near the actuator, such as the code strip, the sensor bar and the fibre optics lines may be unaffected by these fields.

[0052] Furthermore, for very fast actuators, such as a Thomson coil, switching operations may cause accelerations of up to 30000 m/s² on the moving parts of the high voltage switch. The position sensor with a possibly light weighted code strip as the only moving sensor part may withstand these high loads.

[0053] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

[0054] The subject-matter of the invention will be explained in more detail in the following text with reference to exemplary embodiments which are illustrated in the attached drawings.

Fig. 1 schematically shows a high voltage switch according to an embodiment of the invention.

Fig. 2 schematically shows a position sensor for the high voltage switch of Fig. 1.

Fig. 3 schematically shows parts of a position sensor for the high voltage switch of Fig. 1.

Fig. 4 shows a code strip for a position sensor for the high voltage switch of Fig. 1.

[0055] The reference symbols used in the drawings, and their meanings, are listed in summary form in the list of reference symbols. In principle, identical parts are provided with the same reference symbols in the figures.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

[0056] Fig. 1 shows a high voltage switch 10 comprising two electric contacts 12, 14 which are arranged inside a switching chamber 16. The switching chamber 16 may be enclosed by a housing 18 and/or may be filled with an electrically isolating gas, such as SF6. Each electric contact 12, 14 may be electrically connected to a terminal 20 guided outside of the housing 18.

[0057] One of the electric contacts 12 is movable between a closed position and an opened position of the high voltage switch 10. The movable electric contact 12 is movable towards the other electric contact 14 into the closed position for generating an electric connection between the two electric contacts 12, 14 and the terminals 20. The movable electric contact 12 also may be moved away from the electric contact 14 into the opened position, where the electric contacts 12, 14 and/or the terminals 20 are electrically disconnected.

[0058] The electric contact 12 is moved by an actuator 22, which also may be provided inside the housing 18. The actuator 22 may comprise a Thomson coil. It has to be noted that also the electric contact 14 may be movable and/or may be moved with a further actuator.

[0059] The high voltage switch 10 comprises a position sensor 24, which is adapted for determining a position of the electric contact 12. The position sensor 24 comprises an optic sensor part 26 inside the housing 18 and an electric sensor part 27 outside of the housing 18.

[0060] The optic sensor part 26 comprises a code strip 28, which is mechanically connected to the electric contact 12, such that it moves together with the electric contact 12. Furthermore, the optic sensor part 26 comprises a sensor bar 30, which is mechanically connected to a non-moving component of the high voltage switch 10, such as a suspension or bearing of the electric contact 12. However, also other configurations are possible, as described above. In general, the code strip 28 and the sensor bar 30 are attached to the high voltage switch 10 such that a movement of the movable electrical contact 12 is conveyed in a relative movement of the code strip 28 and the sensor bar 30.

[0061] Fibre optics lines 32, 34 interconnect the sensor bar 30 with the electric sensor part 27. The fibre optics lines 32, 34 are guided through the housing 18, however, do not have to be electrically isolated from the housing 18, since they may be made of electrically isolating material.

[0062] Fig. 2 shows a position sensor 24 in more detail. Fig. 2 schematically shows two regions 36, 38 of different electric potential, which are divided by the dashed line. The electric sensor part 27 is provided in a first region 36, which for example may be on ground potential. The optic sensor part 26 is provided in a second region 38, which for example may be on the potential of the switching chamber 16, such as the potential of the electric contacts 12, 14.

[0063] The electric sensor part 27 comprises components that may be influenced by high electric and magnetic fields generated near the electric contact 12. In particular, the electric sensor part 27 comprises a light source 40 adapted for injecting light into the fibre optics lines 32 and several light receivers 42 adapted for converting a light signal from the fibre optics lines 34 into an electrical signal. A light receiver 42 may comprise a sensor for converting light into voltage.

[0064] The electrical signals from the light receivers 42 may be evaluated by a microcontroller 44, which may determine a position of the electric contact 12 based on the light signals.

[0065] The optic sensor part 26 comprises a sensor bar 30 with a light emitting side 46 and a light receiving side 48. The light emitting side 46 comprises a row 50 of light emitting spots 52, each of which is connected to one of the fibre optics lines 32. A light emitting spot 52 may comprise a lens 54, which focuses the light from the respective fibre optics line 32 to the code strip 28. The light receiving side 48 comprises a row 56 of light receiving spots 58, each of which is connected to one of the fibre optics lines 34. A light receiving spot 58 may comprise a lens 54, which focuses the light from the corresponding light emitting spot 52 into the corresponding fibre optics lines 34.

[0066] The code strip 28 comprises a transparent pattern 60, which for example may comprise one or more openings and/or holes in the code strip 28. For example, the code strip 28 may be made of sheet metal. The light emitting spots 52 face the light receiving spots 58 in such a way that when a transparent area of the transparent pattern 60 is between the spots 52, 58, light from the fibre optics line 32 is transmitted into the fibre optics line 34. When a non-transparent area of the code strip 28 is between two corresponding spots 52, 58, the code strip 28 shields the light from spot 52, such that it cannot fall onto the corresponding spot 58.

[0067] Fig. 3 shows an embodiment of an optics sensor part 26, which has two redundant position measurement systems. The optics sensor part 26 has two sensor bars 30, 30', each of which have rows 50, 56 of light emitting spots 52 and rows of light receiving spots 58 that face each other and that are aligned in a direction orthogonal to a movement direction D of the code strip.

[0068] As shown in Fig. 4, the code strip 28 also may have two equally designed transparent patterns 60, 60', each of which is used for shielding/transmitting light between the light emitting spots 52 and the light receiving spots 58. The distance of the transparent patterns 60, 60' may be equal to the distance of the rows 50 or 56 of the two sensor bars 30, 30' as shown in Fig. 3.

[0069] The two transparent patterns 60, 60' and the sensor bars 30, 30' may produce the same state of shielded and/or transmitted light and may be compared due to redundancy and safety reasons. The signals produced by the transparent pattern 60 may be evaluated in the same way as the one of the transparent pattern 60'.

[0070] As shown in Fig. 4, each transparent pattern 60, 60' comprises n (here 3) rows 62, each of which encodes a bit of a code for identifying the current position of the electric contact 12. The transparent pattern 60, 60' and/or the rows 62 are divided into positions 64, which are indicated by 1 to 7 in Fig. 4. When an intersection area of a position 64 with a row 62 is part of the transparent pattern 60, 60', this may encode the bit "I", while an intersection area not part of the transparent pattern 60, 60' may encode the bit "0".

[0071] The position 64 itself may be derived from the encoded bits, since every position has a unique bit code. An example for this is shown in Fig. 4. With n rows 62, 2ⁿ different positions can be encoded. The code corresponding to n zeros may be spared to be able to detect a state, where the light source 40 is not working. This leaves 2ⁿ-1 possibilities for different positions. In the case of Fig. 4, where n=3, 7 different positions are encoded. Furthermore, in Fig. 4 a gray code was used, for which only one bit changes between neighboring positions.

[0072] For example, position 1, which may correspond to a completely open position may be encoded with "010". Position 7, which may correspond to a completely closed position may be encoded by "111". The intermediate positions 2 to 6 are encoded by other bit combinations.

[0073] During the movement of the high voltage switch 10 and in particular the electric contact 12, the light receivers 42 may detect the changing light status caused by the correspondingly moving code strip 28. The electric signals produced by the light receivers 42 correspond to the bit code encoded by the part of the transparent pattern 60 between the rows 50, 56 of light emitting spots 52 and light receiving spots 58.

[0074] The controller 44 may receive the signals from the light receiver 42, may determine the actual code and may determine the actual position 64 from the code. When also the times of a transition between different codes are determined, also a speed and/or acceleration of the code strip 28 and the electric contact 12 can be determined.

[0075] For determining a speed and/or acceleration, the distances between regions of the transparent pattern 60, 60' encoding different positions have to be known and/or may be stored in the controller 44. These distances may be equal, as shown in Fig. 4, or may be different, as shown in Fig. 3. In the example of Fig. 4, the distance between neighboring code positions may be 3.3 mm, while the repeating distance between the transparent patterns 60, 60' is 27 mm.

[0076] The controller 44 may compute a distance/time curve, may record it and/or may visualize it. In particular, the controller 44 is adapted to determine intermediate positions between the opened position and the closed position. The controller 44 also may determine a characteristic of the movement, such as too fast, too slow, no enough travel distance. The switch position and/or the characteristic may be transmitted to a further system, such as a SCADA system.

[0077] While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive; the invention is not limited to the disclosed embodiments. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art and practising the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. A single processor or controller or other unit may fulfil the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.

LIST OF REFERENCE SYMBOLS

[0078] 

10

high voltage switch

12

movable electric contact

14

second electric contact

16

switching chamber

18

housing

20

terminal

22

actuator

24

position sensor

26

optic sensor part

27

electric sensor part

28

code strip

30, 30'

sensor bar

32

first fibre optics line

34

second fibre optics line

36

first potential region

38

second potential region

40

light source

42

light receiver

44

controller

46

light emitting side

48

light receiving side

50

row

52

light emitting spots

54

lens

56

row

58

light receiving spot

60, 60'

transparent pattern

D

movement direction

62

code strip row

64

position

Claims

1. A high voltage switch (10), comprising:

a movable electric contact (12) movable with respect to a further electric contact (14) between a closed position, in which the electric contacts (12, 14) are connected and an opened position, in which the electric contacts (12, 14) are disconnected;

a position sensor (24) for determining a position (64) of the movable electric contact (12), the position sensor (24) comprising:

a sensor bar (30) with a light emitting side (46) and a light receiving side (48);

a code strip (28) comprising a transparent pattern (60), wherein the code strip (28) is arranged between the light emitting side (46) and the light receiving side (48);

an electric sensor part (27) comprising a light source (40) and at least one light receiver (42) for converting a light signal into an electric signal;

fibre optics lines (32, 34) for connecting the light source (40) with the light emitting side (46) and for connecting the light receiving side (48) with the at least one light receiver (42);

wherein the code strip (28) and the sensor bar (30) are attached to the high voltage switch (10) such that a movement of the movable electrical contact (12) is conveyed in a relative movement of the code strip (28) and the sensor bar (30).

2. The high voltage switch (10) of claim 1,
wherein the light emitting side (46) of the sensor bar (30) comprises a row (50) of light emitting spots (52), each of which is connected to a fibre optics line (32);
wherein the light receiving side (48) of the sensor bar (30) comprises a row (56) of light receiving spots (58), each of which is connected to a fibre optics line (34);
wherein the row (50) of light emitting spots (52) and the row (56) of light receiving spots (58) are aligned orthogonal to a movement direction (D) of the code strip (28).

3. The high voltage switch (10) of claim 1 or 2,
wherein the transparent pattern (60) of the code strip (28) is formed, such that it encodes a bit code for a position (64) of the code strip (28), where the transparent pattern (60) shields light emitting spots (52) of the light emitting side (46) from light receiving spots (58) of the light receiving side (48) of the sensor bar (30).

4. The high voltage switch (10) of one of the previous claims,
wherein the code strip (28) has a first transparent pattern (60) for the sensor bar (30) and an equal second transparent pattern (60') for a second sensor bar (30');
wherein the second transparent pattern (60') and the second sensor bar (30') are spaced apart from the first transparent pattern (60) and the first sensor bar (30) in a movement direction (D) of the code strip (28) .

5. The high voltage switch (10) of one of the previous claims,
wherein the sensor bar (30) and/or the code strip (28) are on the same electric potential as the movable electric contact (12).

6. The high voltage switch (10) of one of the previous claims,
wherein the electric sensor part (27) is arranged at a position having a different electric potential as the movable electric contact (12); and/or
wherein at least some of the fibre optics lines (32, 34) are guided between different electric potentials.

7. The high voltage switch (10) of one of the previous claims,
wherein the high voltage switch (10) comprises a housing (18), in which the electric contacts (12, 14) are arranged; and/or
wherein an isolating gas is provided inside the housing (18).

8. The high voltage switch (10) of claim 7,
wherein the code strip (28) and the sensor bar (30) of the position sensor (24) are arranged inside the housing (18).

9. The high voltage switch (10) of claim 7 or 8,
wherein the electric sensor part (27) is arranged outside of the housing (18); and/or
wherein the fibre optics lines (32, 34) are guided from an inside of the housing (18) to an outside of the housing (18).

10. The high voltage switch (10) of one of the previous claims,
wherein the code strip (28) is rigidly connected to the movable electric contact (12).

11. The high voltage switch (10) of one of the previous claims,
wherein the code strip (28) is a metal strip; and/or
wherein the transparent pattern (60) is composed of openings in the code strip (28).

12. The high voltage switch (10) of one of the previous claims,
wherein the electric sensor part (27) comprises a controller (44) for evaluating one or more electric signals from the light receivers (42).

13. The high voltage switch (10) of claim 12,
wherein the controller (44) is adapted for determining a position of the movable electric contact (12);
wherein the controller (44) is adapted for determining a speed of the movable electric contact (12).

14. The high voltage switch (10) of one of the previous claims,
wherein the high voltage switch (10) comprises an actuator (22) for moving the movable electric contact (12).

15. The high voltage switch (10) of claim 14,
wherein the actuator (22) is a Thomson coil.

Drawing