Sensing device

Abstract

A sensing device (10) for a high voltage disconnect switch (20). The sensing device (10) includes a first optical fiber (110) configured to receive light from a light source (100) and configured to direct the light, an optical collimator (120) coupled to the first optical fiber (110) to receive the light directed into the first optical fiber (110) and configured to collimate the light into a collimated light beam, and an optical collimator (120) configured to bend in response to a switching state of the high voltage disconnect switch (20). a bendable optical component (130) configured and arranged to affect the collimated light beam, the bendable optical component (130) being coupled to the optical collimator (120) to receive the collimated light beam and configured to direct the collimated light beam; and a derivation unit (160) configured to derive information regarding a switching state of the high voltage disconnect switch (20) based on the collimated light beam.

Description

Technical Field

[0001] The present invention generally relates to the field of sensing devices. More particularly, the present invention relates to a sensing device for a high-voltage disconnect switch and a high-voltage disconnect switch having such a sensing device.

[0002] Disconnect switches are generally known in the art. Such disconnect switches can take two dedicated states, namely an on state (ON) and an off state (OFF). In some applications, detection of each state of the disconnect switch (also simply referred to as a circuit breaker) is required.

[0003] Smart substation devices are opening the way to improve operational safety and reduce downtime. Digitalization of asset status by smart sensors enables high-speed error location and predictive maintenance. Breaking-closing disconnecting switches (BCDS) are a special type of disconnect switch and are one of the most important components in today's substations. These components have moving parts. Therefore, the operation of BCDS can, of course, have subsequent failure modes: · The switch is mechanically blocked in a position that is neither "open" nor "closed" · The relative position of the male contact and the female contact is not completely "closed" (the pressure by finger is weak), which may cause heating of the contact, thereby reducing the current flowing therethrough.

[0004] There is an increasing demand for online monitoring of disconnect switches such as BCDS.

[0005] IEC 62271-102 shows the general mandatory type of tests for disconnectors. According to IEC, the device is expected to correctly indicate the position of the disconnector. Such a device is not specified in detail. It has long been said that BCDS causes most of the important events related to the safety of the electrical system in the substation. The main problem that occurs is the loss of information on whether it is "open or closed". Such events limit topological changes, weaken the substation system, and require on-site intervention. These facts have motivated the development of smart sensors for monitoring the device status. By using such sensors, insights into the health of BCDS can be obtained through data recording and processing, and preventive actions can be initiated if necessary.

[0006] Currently, several techniques for online monitoring of BCDS are being investigated. Various different methods are currently being explored to enable the monitoring of the switch state. For example, real-time monitoring of the operating torque of the circuit breaker has been proposed by S. Douillard et al. in “Disconnectors reliability on the French grid and means to reduce the consequences of their failures on the electrical system”, Cigre 2018. By the method described here, the movement of the switch can be compared with the minimum and maximum values. It has been reported that the operating torque value is highly related to the temperature of the environment. This needs to be corrected by an algorithm.

[0007] An overview of additional monitoring techniques is described in Bozhong et al. “Review on Breaking-closing Position Monitoring Method for Intelligent Disconnecting Switches”, IOP Conf. Ser.: Earth Environ. Sci. 223, 2018. The method under research is image recognition. The purpose in this method is to extract features from the image area and infer the state of the BCDS. This can be done by a fixed camera or a moving camera for observing the switch. In addition to advantages such as high automation and scalability, this method also has disadvantages such as sensitivity to weather conditions and high cost. Furthermore, since a camera is used for photography, this method is susceptible to the influence of magnetic fields in the BCDS environment.

[0008] Optical-based approaches have been proposed. For example, a laser source and a reflecting mirror are used to prove whether the switch contacts are in the correct position. In another approach, three subsystems are integrated into one monitoring unit. Sensing of the relative position is performed using one LED and 32 phototransistors. MEMS was used to enable vibration measurement during operation. A solar panel was used as the current source. The operating duration of the monitoring unit was related to the data communication frequency. In the presented optical-based methods, it is expected that neither a sufficiently good spatial resolution measurement nor a sufficiently good temporal resolution measurement is provided to enable predictive maintenance. Furthermore, all subsystems used necessarily require a current flow. It is unclear how the accurate calibration and stable operation of the electrically driven subsystems can be ensured in the immediate vicinity of a strong magnetic field.

[0009] Fiber-based displacement measurement is being considered. The power coupling losses between optical fibers with the same numerical aperture (NA) and different numerical apertures (NA) have been investigated previously. For example, the coupling efficiency between two fibers with an angular misalignment has been calculated. Furthermore, in addition to the angular misalignment, a misalignment loss caused by a lateral misalignment has been proposed. In both cases, only the two fiber ends without other optical components are considered.

[0010] Fiber-based bending sensors are being considered in relation to fiber-based bending sensors realized by fiber Bragg diffraction gratings (FBGs). Such components have a refractive index structure local to the target point (about 20 mm in length), which reflects / transmits a signal arriving at a predetermined wavelength at a predetermined rate like a mirror. When the FBG is subject to environmental influences such as tensile stress, temperature change, and humidity, the amount of reflected / transmitted light changes significantly. Such sensors and reading units are commercially available.

[0011] In summary, at the current state of the art, the BCDS cannot meet the requirements for measuring critical physical quantities under extreme environmental conditions in which it operates.

[0012] Therefore, there is a need to improve the sensing device for the high-voltage disconnect switch. For example, a sensing device for the high-voltage disconnect switch that provides accurate results and / or enables reliable monitoring of the high-voltage disconnect switch may be required.

[0013] According to a first aspect of the present invention, a sensing device for a high-voltage disconnect switch is proposed. The sensing device includes a first optical fiber, an optical collimator, a bendable optical component, and a derivation unit. The first optical fiber is configured to receive light from a light source and to guide the light. The optical collimator is coupled to the first optical fiber for receiving the light guided into the first optical fiber. The optical collimator is configured to collimate the light into a collimated light beam. The bendable optical component is coupled to the optical collimator for receiving the collimated light beam. The bendable optical component is configured to guide the collimated light beam. The bendable optical component is configured and arranged to bend according to the switching state of the high-voltage disconnect switch, whereby the collimated light beam is affected. In other words, the collimated light beam can be affected by bending the bendable optical component. The derivation unit is configured to derive information regarding the switching state of the high-voltage disconnect switch based on the collimated light beam.

[0014] The high-voltage disconnect switch may be any switching device that can be used in a high-voltage environment for connecting (in the on state of the high-voltage disconnect switch) and disconnecting (in the off state of the high-voltage disconnect switch) a device. One or more different mechanisms or components may be installed or arranged in the high-voltage disconnect switch to turn it from the on state to the off state and from the off state to the on state, which may be, for example, a switch arm. The light source may be any light source such as a laser light source. The light may be laser light. The light source may be directly or indirectly coupled or connected to the optical collimator and / or the bendable optical component. The optical collimator may be a collimating lens and / or a converging lens. For example, the optical collimator may be a first collimating lens or may include a first collimating lens.

[0015] The bendable optical component is configured and arranged to bend according to the switching state of the high-voltage cut-off switch. The optical characteristics of the bendable optical component may be changed based on the bending or degree of bending or bending state of the optical component. The collimated light beam may propagate differently based on the bending or degree of bending or bending state of the bendable optical component. The bending of the bendable optical component may change the optical characteristics of the bendable optical component and thus the optical characteristics of the collimated light beam. Depending on the degree of bending (bending degree) of the bendable optical component, the optical characteristics of the collimated light beam may change. For example, as the degree of bending of the bendable optical component increases, the optical loss in the collimated light beam may increase.

[0016] The bending or degree of bending or bending state of the bendable optical component may be related to the switching state of the high-voltage cut-off switch. Therefore, the derivation unit may be configured to derive the switching state of the high-voltage cut-off switch from the bending or degree of bending or bending state of the bendable optical component. For example, the high-voltage cut-off switch or one or more components of the high-voltage cut-off switch, such as the switch spring or switch arm of the high-voltage cut-off switch, may be directly or indirectly coupled or connected to a sensing device, such as the bendable optical component of the sensing device. The switch arm may be understood as a movable element. The switch arm can turn the switch, i.e., the high-voltage cut-off switch, from the off state to the on state and can also turn the high-voltage cut-off switch from the on state to the off state. The switch arm may be considered as a male-shaped contact in some cases. The switch arm may be provided with a metal contact. The switch spring (e.g., a left-handed spring and a right-handed spring) may be a static element that cannot move or cannot be moved. The switch spring may be considered as a female-shaped contact or a part of the female-shaped contact in some cases. In other words, the switch arm may be a movable element that moves the switch from the off state to the on state and from the on state to the off state. A contact element, such as a copper contact, may be provided at the end of each switch arm. The switch spring may be an element that can be added to the female-shaped copper contact to ensure a tight connection or to ensure that the connection is tight. The derivation unit may be directly or indirectly coupled or connected to the focusing optical system and / or the bendable optical component.

[0017] According to a first possible embodiment of the sensing device, the optical collimator may be directly or indirectly coupled to a first end of the bendable optical component, for example, the input end of the bendable optical component. The sensing device may further include a focusing optical system and a second optical fiber. The focusing optical system may be directly or indirectly coupled to a second end of the bendable optical component, for example, the output end of the bendable optical component, to receive the collimated light beam guided into the bendable optical component. The focusing optical system may be directly or indirectly coupled to the second optical fiber. The focusing optical system may be configured to focus the collimated light beam onto the second optical fiber. The second optical fiber may be configured to guide the focused light. The derivation unit may be directly or indirectly coupled to the second optical fiber to receive the focused light guided into the second optical fiber. The derivation unit may be configured to derive information regarding the switching state of the high-voltage cut-off switch based on the received focused light. For example, the derivation unit may be configured to derive information regarding the switching state of the high-voltage cut-off switch only from the received focused light. The focusing optical system may be a collimating lens and / or a converging lens. For example, the focusing optical system may be a second collimating lens different from, for example, the first collimating lens of the optical collimator, or may include a second collimating lens.

[0018] According to a second possible embodiment of the sensing device, the optical collimator may be directly or indirectly coupled to the first end of the bendable optical component. The sensing device may further include a mirror ring component and a focusing optical system. The mirror ring component may be coupled to the second end of the bendable optical component to reflect the collimated light beam back to the first end of the bendable optical component. The focusing optical system may be coupled to the first end of the bendable optical component to receive the reflected and collimated light guided into the bendable optical component. The focusing optical system may be directly or indirectly coupled to the first optical fiber. The focusing optical system may be configured to focus the reflected and collimated light beam onto the first optical fiber. The first optical fiber may be configured to guide the focused light. The derivation unit may be directly or indirectly coupled to the first optical fiber to receive the focused light. The derivation unit may be configured to derive information regarding the switching state of the high-voltage disconnect switch based on the received focused light. The derivation unit may be configured to derive information regarding the switching state of the high-voltage disconnect switch only from the received focused light. The focusing optical system may be a collimating lens and / or a converging lens. For example, the focusing optical system may be an optical collimator, such as a first collimating lens, or may include an optical collimator, such as a first collimating lens.

[0019] An optical collimator, such as a first collimating lens, may be configured to collimate the light received at the first end / surface of the optical collimator and to focus the collimated light received at the second end / surface of the optical collimator.

[0020] The derivation unit may include a conversion component configured to convert the received light into at least one voltage value. For example, the conversion component may be configured to convert the received focused light into at least one voltage value. The derivation unit may further include a monitoring component configured to determine the switching state of the high-voltage cut-off switch based on the at least one voltage value.

[0021] The monitoring component may be configured to determine the amount of bending or the degree of bending of the bendable optical component based on at least one voltage. The monitoring component may be configured to determine the switching state of the high-voltage cut-off switch based on the amount of bending or the degree of bending of the bendable optical component.

[0022] The monitoring component may be configured to continuously or repeatedly determine the switching state of the high-voltage cut-off switch. In this way, (online) monitoring and / or maintenance of the high-voltage cut-off switch can be provided.

[0023] The sensing device may further include a first adapter. The first adapter may be disposed or attached to the first side / end of the bendable optical component. For example, the first adapter may be disposed between the optical collimator and the bendable optical component. The optical collimator may be attached to the first side of the first adapter. The bendable optical component may be attached to the second side of the first adapter.

[0024] The sensing device may further include a second adapter. The second adapter may be disposed or attached to the second side / end of the bendable optical component. For example, in the above-described first embodiment, the second adapter may be disposed between the focusing optical system and the bendable optical component. The bendable optical component may be attached to the first side of the second adapter. The focusing optical system may be attached to the second side of the second adapter.

[0025] The bendable optical component may be fixed at one end. The bendable optical component may be freely bendable at the other end. For example, the bendable optical component may be fixedly attached to the first adapter and movably attached to the second adapter. In this way, the bendable optical component may be freely bendable or movable, for example, within the second adapter, at the other end.

[0026] The bendable optical component may include an optical tube or may be configured as an optical tube. Alternatively, the bendable optical component may be a cylindrical optical fiber. The cylindrical optical fiber may have a tapered portion. Alternatively, the bendable optical component may be a pair of optical fiber ends. The pair of optical fiber ends may be coupled on a flexible substrate.

[0027] According to a second aspect of the present invention, a high-voltage disconnect switch is proposed. The high-voltage disconnect switch comprises the sensing device described herein.

[0028] The high-voltage disconnect switch may comprise a spring / switch spring and / or a switch arm, which are configured to deform or change their shape when the switching state of the high-voltage disconnect switch changes. For example, when the switching state of the high-voltage disconnect switch changes from the on state to the off state, the spring / switch spring or the switch arm may be deformed or change their shape. A sensing device, such as a bendable optical component, may be directly or indirectly coupled or connected to the switch spring or the switch arm such that the deformation or change in shape of the spring / switch spring or the switch arm causes the bending of the bendable optical component. For example, in the on state, these switch arm elements may be connected to each other, and in the off state, these switch arm elements may be disconnected from each other. Thus, during the transition from the on state to the off state, these switch arm elements may change their positions relative to each other, thereby causing the bending of the bendable optical component in response to this change in relative position. These elements of the switch arm may change their relative positions, for example, by performing a rotational movement relative to each other.

[0029] The high-voltage disconnect switch may be configured as or may comprise a breaking-closing disconnecting switch (BCDS), a centre break disconnecting switch, a double break disconnecting switch, a vertical break disconnecting switch, a pantograph disconnecting switch, a semi-panthograph disconnecting switch or a knee type disconnecting switch.

[0030] All of the details described herein with respect to the sensing device according to the first aspect can be equally applied to the sensing method using the high-voltage disconnect switch and / or the sensing device according to the second aspect. Thus, even if some of the aspects described above are described in relation to the sensing device and / or the high-voltage disconnect switch, these aspects can also be applied to the method, and vice versa.

[0031] It will be apparent to those skilled in the art that the descriptions set forth herein can be implemented using hardware circuits, software means, or combinations thereof. The software means may be associated with a programmed microprocessor or general-purpose computer, an ASIC (application-specific integrated circuit) and / or a DSP (digital signal processor). For example, the processing unit can be implemented at least in part as a computer, logic circuit, FPGA (field programmable gate array), processor (e.g., microprocessor, microcontroller (μC) or array processor) / core / CPU (central processing unit), FPU (floating point unit), NPU (numerical processing unit), ALU (arithmetic logic unit), coprocessor (another microprocessor that supports the main processor (CPU)), GPGPU (general-purpose computing on graphics processing units), or a multi-core processor or DSP for parallel computing (e.g., simultaneous execution of arithmetic operations on multiple main processors and / or graphics processors). For example, one or more of the above-described components can be implemented in the derivation unit, such as in the conversion component and / or the monitoring component.

[0032] Terms such as "first" or "second" can be used to describe different components or features, but these components or features should not be limited to these terms. One component should simply be distinguished from the other by the above terms. For example, without departing from the scope of the present disclosure, the first component may be referred to as the second component. Also, the second component may be referred to as the first component.

[0033] In this case, when a part is "connected" or "coupled" to another part, this does not exclude that it is directly connected or directly coupled to this other part, but there may be another part between these connected or coupled parts. On the other hand, when a part is "directly connected" to another part or "directly coupled" to this other part, it should be understood that there is no further part between these connected or coupled parts.

[0034] Hereinafter, preferred embodiments of the present disclosure will be described with reference to the accompanying drawings. In the drawings, the same parts or corresponding parts are always given the same reference numerals. The dimensions and ratios of the parts or components shown are not necessarily to scale. These dimensions and ratios may be different from the illustrations in the drawings and the embodiments to be implemented.

[0035] Next, the above aspects and optional details of the present invention will be described in detail by way of example only with reference to the accompanying drawings. Here, the same reference numbers refer to the same parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0036]

Figure 1

Figure 2a

Figure 2b

Figure 2c

Figure 3a

Figure 3b

Figure 4a

Figure 4b

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9a

Figure 9b

Figure 10a

Figure 10b

Figure 11

[0037] In the following description, for purposes of explanation and not limitation, specific details are set forth in order to provide a thorough understanding of the present disclosure. It will be apparent to one of ordinary skill in the art that the present disclosure may be practiced in other embodiments that depart from these specific details. Even if the present disclosure is sometimes or mainly described hereinafter with respect to BCDS, the present disclosure may be equally practiced in or with other high-voltage disconnect switches.

[0038] It will also be apparent to one of ordinary skill in the art that the functions described hereinafter may be implemented using individual hardware circuits, using software operating in conjunction with a programmed microprocessor or a general-purpose computer, using an application specific integrated circuit (ASIC), and / or using one or more digital signal processors (DSPs). Also, when the present disclosure is described as a method, it will be understood that the present disclosure may also be embodied in an apparatus (i.e., the sensing apparatus and high-voltage disconnect switch described hereinafter), a computer processor, and a memory coupled to the processor. In this case, the memory is encoded with one or more programs that, when executed by the processor, implement the methods disclosed herein.

[0039] Generally, for high voltage disconnect switches, especially in the case of BCDS devices, there is no established direct measurement of the "on" and "off" states of the switch or switch arm. Figure 1 shows the change in the spring strain of the switch over time during the "on" (closed state) and "off" (open state) switching procedures. In other words, Figure 1 shows the strain (in Newtons) in the latch of the BCDS switch arm. For a typical center break disconnect switch, during the switching from "on" to "off" (0 seconds to 15 seconds), the spring strain changes from 350 N to 0 N. The reverse of the procedure is shown between 15 seconds and 40 seconds. In this case, the strain changes from 0 N to 350 N again. It can also be seen in Figure 1 that there is a specific tolerance for the strain every cycle of approximately 100 N. Considering Figure 1, a direct measurement system compatible with the high voltage environment is required. The strain applied to such a spring was measured in the range of 1 mm to 4 mm, without current, on the BCDS in the figure. This solution should break down this process on the order of 40 seconds, using an appropriate number of data points covering the determined range of flexion (in mm).

[0040] The solutions described herein solve the problem of online monitoring of the "on" and "off" switching procedures of BCDS with a high temporal resolution in the range above 1 data point per second. The presented solutions are designed for high-voltage disconnector switches and are described in particular with respect to center-break disconnector switches. In principle, this can also be adapted, for example, for double-break disconnector switches, vertical-break disconnector switches, pantograph disconnector switches, semi-pantograph disconnector switches and n-type disconnector switches. The sensing device described herein has a specific optical and mechanical design including fibers, lenses, mounts and is adapted to detect the movement of the switch arm, such as the latch, during the "on" and "off" switching procedures. Since this system is designed for direct contact measurements, the failure probability is low. In the presented approach, the optical and electro-optical components are spatially separable, so that difficult environmental conditions (weather, electric and magnetic fields, high temperatures of metal parts) can be coped with. By combining with high-speed reading and specially adapted intelligent algorithms, the presented solutions represent a further step for the digital business model. This will help to solve customer problems such as substation downtime and enable predictive maintenance.

[0041] Three possible embodiments of the sensing device (sensing unit) are shown in FIGS. 2a to 2c. Common to all embodiments is the sensing device 10 for the high-voltage disconnect switch. This embodiment is referred to as the common embodiment herein. The sensing device 10 includes a first optical fiber 110, an optical collimator 120, a bendable optical component 130, and a derivation unit 160. The first optical fiber 110 is configured to receive light from a light source 100. In the common embodiment, the first optical fiber 110 is connected to the light source 100, for example, directly connected. The first optical fiber 110 is configured to guide the light received from the light source 100. The optical collimator 120 is coupled to the first optical fiber 110, for example, directly coupled, to receive the light guided into the first optical fiber 110. The optical collimator 120 is configured to collimate this light into a collimated light beam. The bendable optical component 130 is coupled to the optical collimator 120, for example, directly coupled, to receive the collimated light beam. The bendable optical component 130 is configured to guide the collimated light beam. In other words, the collimated light beam propagates within the bendable optical component 130. The bendable optical component 130 is configured and arranged to bend according to the switching state of the high-voltage disconnect switch. Thereby, the collimated light beam is affected, or the optical characteristics of the bendable optical component 130 and / or the collimated light beam are changed. The derivation unit 160 is configured to derive information regarding the switching state of the high-voltage disconnect switch based on the collimated light beam. In other words, the derivation component 160 derives whether the collimated light beam or the optical characteristics of the collimated light beam change, and thereby derives information regarding the switching state, for example, whether the high-voltage disconnect switch is in the on state or the off state, or whether the switching procedure from the on state to the off state and / or the switching procedure from the off state to the on state is correctly executed.

[0042] In the following embodiments, the optical collimator 120 is configured as a collimating lens for illustrative purposes only and not by way of limitation, and will hereinafter be referred to as the collimating lens 120. In the following embodiments, the bendable optical component 130 is configured as a bendable optical tube for illustrative purposes only and not by way of limitation, and will hereinafter be referred to as the bendable optical tube 130 (or simply the tube 130 in some cases). In the following embodiments, the derivation unit 160 includes a photodiode 170 and a monitoring component 180 for illustrative purposes only and not by way of limitation.

[0043] Hereinafter, details of the bendable optical component 130 configured as a bendable optical tube will be described, but other configurations are also possible. For example, the bendable optical component 130 may be configured as a cylindrical fiber. The cylindrical fiber may have a tapered portion on the right side of the target point. Further, the bendable optical component 130 may be configured as a pair of optical fiber ends. The pair of optical fiber ends 130 may be butt-coupled to a flexible substrate without any optical component sandwiched therebetween.

[0044] The first embodiment is shown in FIG. 2a. In this embodiment, the sensing device 10 is configured in a transmission arrangement. The sensing device 10 includes a first optical fiber 110, a first collimating lens 120, a bendable optical tube (or simply the tube) 130 through which the collimated light beam is guided, a second lens 140 that focuses the collimated light beam, and a second optical fiber 150 into which the light (from the bendable optical tube 130) is coupled. The second lens 140 may be a condenser lens, a focusing lens, and / or a collimating lens, and will hereinafter be referred to as the second collimating lens 140. The light focused by the second lens 140 is coupled to the second optical fiber 150 and guided to a derivation unit 160 including a photodiode 170 and a monitoring component 180.

[0045] The second embodiment is shown in FIG. 2b. In this embodiment, the sensing device 10 is configured in a reflection arrangement. The sensing device 10 includes a first optical fiber 110, a first collimating lens 120, a bendable optical tube (or simply tube) 130 through which the collimated beam is guided, a mirror 190 that reflects the collimated light beam, and a focusing optical system 120 that focuses the collimated beam. The focusing optical system 120 is configured as, for example, the first collimating lens 120. The first collimating lens 120 is configured to collimate light incident from one side (the right side in FIG. 2b) and to focus the collimated light incident from the other side (the left side in FIG. 2b). The light focused by the collimating lens 120 is coupled to the first optical fiber 110 and guided to a derivation unit 160 including a photodiode 170 and monitoring components 180.

[0046] The third embodiment is shown in FIG. 2c. In this embodiment, the sensing device 10 is configured in a reflective arrangement with a plurality of sensing units or a plurality of bendable optical tubes 130. The sensing device 10 includes a first optical fiber, a fiber switch 195, a plurality of first collimating lenses 120, a plurality of bendable optical tubes (or simply tubes) 130 into which the collimated beams are respectively guided, a plurality of mirrors 190 for reflecting the collimated beams respectively, and a plurality of focusing optical systems 120 for focusing the collimated beams respectively. The fiber switch 195 is configured to split the light received from the light source 100 into a plurality of light beams and distribute these plurality of light beams to a plurality of optical fibers. Similarly, the fiber switch 195 is configured to receive light beams from a plurality of optical fibers, combine these plurality of light beams, and form one light beam that is guided by the optical fiber to the derivation unit 160. The focusing optical system 120 is configured as, for example, the first collimating lens 120. These collimating lenses 120 are each configured to collimate the light incident from one side (the right side in FIG. 2c) and are each configured to focus the collimated light incident from the other side (the left side in FIG. 2c). The light focused by the collimating lens 120 is respectively coupled to another optical fiber, guided to the fiber switch 195, and from the fiber switch 195, through another optical fiber, to the derivation unit 160 including the photodiode 170 and the monitoring component unit 180.

[0047] The following description generally applies to all of the above-described embodiments, namely, the common embodiment, the first embodiment, the second embodiment, and the third embodiment. One of the main concepts is to convert the bending amplitude of the switch spring or switch arm of the high-voltage disconnect switch into a change in the optical characteristics of the bendable optical tube 130. The bending amplitude of the switch spring or switch arm may be from 1.5 mm to 4.5 mm. The change in the optical characteristics can be the optical loss caused by bending the tube 130 through which the collimated (free) light beam is propagating.

[0048] An example of the high-voltage disconnect switch 20 is shown in FIG. 3a together with the switch spring or switch arm 200. The bending of the switch spring or switch arm 200 is shown in FIG. 3b. The bending of the switch spring or switch arm 200 is caused by the change in the state of the switch spring or switch arm 200 from the off state (OFF) shown at the top of FIG. 3b to the on state (ON) shown at the bottom of FIG. 3b, or by the change in the state of the switch spring or switch arm 200 from the on state (ON) shown at the bottom of FIG. 3b to the off state (OFF) shown at the top of FIG. 3b.

[0049] The switch spring or switch arm 200 is directly or indirectly coupled to or connected to the tube 130. Thus, when the switch spring or switch arm 200 is bent, the tube 130 is bent. The relaxed tube 130 and the bent tube 130 are schematically shown in FIG. 4a. At the top of FIG. 4a, the relaxed (unbent) tube 130 is shown, and at the bottom of FIG. 4a, the bent tube 130 is shown. The arrow marked A and the arrow marked B indicate the vectors of the movement of the sample at the tube end, for example, the right end of the tube 130. The vectors A and B can have the following values: A = 0…4 mm, B = 0…4 mm. As an example, the tube 130 is fixed at one end (the left end), and the other end (the right end) is freely bendable. Thus, FIG. 4a shows the bending of one end (right) of the tube 130 and the fixing of the other end (left).

[0050] The sensing device 10 can be attached to the switch spring or switch arm 200, such as a high-voltage cut-off switch, more specifically a BCDS spring or BCDS arm, in various ways. One way of attaching the sensor to the BCDS spring or BCDS arm 200 is shown in FIG. 4b. As can be seen from FIG. 4b, the bendable tube 130 is in contact with the spring or arm 200, whereby the tube 130 is bent when the spring or arm 200 is bent or when it changes from the closed state (off) to the open state (on).

[0051] The measurement principle can be realized when the setup in any one of FIGS. 2a to 2c is used. Further, the parts used in the sensing device 10 may have characteristics within the range shown in Table 1 below. The embodiments shown in any one of FIGS. 2a to 2c were successfully realized in experiments using the characteristics in Table 1.

[0052]

Table 1-1

Table 1-2

[0053] Figure 5 shows the transfer function for the bending of sensor (sensing device) 10 from 0 mm to 3 mm. This transfer function shows how the linear movement of the length (in mm) is related to the bending of sensor 10, more specifically tube 130, and converts this bending into an optical loss (in μV) measured by photodiode 170. The measurement results are shown in Figure 5 for two tubes 130 having lengths of 10 mm and 15 mm. The x-axis shows the number of continuously measured data points, and the y-axis shows the voltage (in μV) measured using photodiode 170. The movement comprises 60 linear translation steps of 50 μm, resulting in a maximum bending of 3 mm. As a result of the bending from 0 mm to 3 mm, the measured voltage clearly drops from 11430 μV to 21 μV. It can be seen that the exact slope (in μV / mm) can be adjusted by changing the geometry of the tube. It can also be seen from Figure 5 that sensor 10 can resolve a 50 μm bend. Thus, a high resolution of the bending procedure (of tube 130) and thus also of the switching procedure (of high-voltage cut-off switch 10) is achieved.

[0054] FIG. 6 shows an optical setup of the sensing transducer of the sensing device 10, more specifically a possible detailed implementation. The specific implementation of FIG. 6 is adapted to be used in the schematic setup of FIG. 2a, but can also be adapted to be used in the setups of FIGS. 2b and 2c (Note: FIG. 6 is a mirror image of FIG. 2a, i.e., the left and right sides are swapped). In FIG. 6, for the optical fibers 110, 150, an exemplary core diameter of 200 μm and an NA of 0.37 are used for the first optical fiber 110 and the second optical fiber 150. Each fiber end is connectorized, by way of example, in a Sub Miniature version A (SMA) format. The collimators / collimating lenses 120, 140 having a focal length of 6.25 mm and an NA of 0.37 are used to collimate the beam from the first optical fiber 110 and refocus it onto the end face of the second optical fiber 150 for transmission within the tube 130. Adapters 125, 135 are disposed between the tube 130 and the collimators 120, 140. These adapters 125, 135 allow for a fixed attachment by screwing the collimators 120, 140 into the adapters 125, 135 on one side and the tube 130 into the adapters 125, 135 on the other side. Even when both ends of the tube 130 are fixed, it is still possible for other parts of the tube 130 to bend or be bent. The optical transmission efficiency of the sensor 10 was 48% in the experiment.

[0055] Figure 7 shows the stability of the light source. More specifically, it shows the output power of the laser diode over time that can be used for the laser light source, for example, the light source 100 in FIGS. 2a - 2c. The light source 100 used is a laser diode having a wavelength of 640 nm and an output power of 16.2 mW. The emitted power was measured over time in order to be able to resolve the repetition accuracy during the simulated mechanical switch cycles. The results are shown in Figure 7. From the measured data, a standard deviation of 0.028 mW was calculated. This is equal to a rate of 0.17%. When using this light source, the most expected repetition accuracy between the simulated switch cycles has a value of 0.17%. Thus, stability is achieved.

[0056] Figure 8 shows the movement of the simulated switch arm 200. More specifically, it shows the movement of the switch simulated with a linear stage, for example, the movement of the switch arm. FIGS. 9a and 9b show examples for a tube length of 100 mm, an example with A = 1 and B = 0.5 (FIG. 9a) and an example with A = 3 and B = 1.5 (FIG. 9b). FIGS. 10a and 10b show the movement of the switch simulated with a linear stage with A = 2 and B = 1 (FIG. 10a) and the movement of the switch simulated with a linear stage with A = 4 and B = 2 (FIG. 10b) for a tube length of 150 mm.

[0057] By using a linear stage, vectors A and B in Fig. 4a can be realized at regular intervals. In the case of BCDS, it should be noted that it has been demonstrated that the lengths of vectors A and B are between 1 mm and 4 mm. Therefore, when the length of the tube is 100 mm, the values of A and B are selected as (A = 1; B = 0.5) and (A = 3; B = 1.5), and when the length of the tube is 150 mm, they are selected as (A = 2; B = 1) and (A = 4; B = 2). This was done taking into account the change in bending per switch cycle and the tolerance between individual switch devices. The results for a tube length of 100 mm are shown in Figs. 9a and 9b, and the results for a tube length of 150 mm are shown in Figs. 10a and 10b.

[0058] Voltage changes caused by optical losses during the switching process have a typical signature for a properly operating BCDS. This signature is recorded and illustrated in FIGS. 9, 10a, 10b, 11a, and 11b. The voltage change over time can be recorded using a microcontroller connected to data storage (local or cloud-based). The microcontroller and / or data storage may be implemented within the monitoring component 180. Alternatively, the microcontroller may be implemented within the monitoring component 180 and the data storage may be at least partially disposed within a component that communicates or is capable of communicating wirelessly and / or wired with the monitoring component 180. Variations in the characteristic parameters of the signature for each cycle (FIG. 9) can be measured for individual properly operating switches 20 (e.g., depth, duration, etc.). Also, this data can be used to classify whether the switch 20 is in the open position or the closed position, for example, to classify whether the switch spring or switch arm 200 is in the open position or the closed position. The change in the characteristic signature parameters with the scaling number of actual switch cycles can be correlated in an accelerated lifetime test. This enables predicting the soundness of the switch device based on data measured by the sensing system or sensing device 10.

[0059] At present, only highly reactive, and in some cases preventive, maintenance is possible for the BCDS device. With the presented concepts and solutions, predictive maintenance can be performed. In particular, the latch of the BCDS spring or BCDS arm 200 having a duration of only a few seconds can be disassembled with high precision. This is the only reported method of directly measuring the movement of the spring or arm. Thus, by using these data, it becomes possible to detect malfunctions in the latching procedure that can affect the lifetime of the device. The data can be fed into models such as lifetime models, probabilistic failures, and the law of large numbers. That is, the sensing device 10 can not only determine the switching state with respect to the on (closed) or off (open) state of the switch 20, but rather, the sensing device 10 can also monitor the switching or latching procedure with high resolution, thereby detecting malfunctions in the switching or latching procedure.

[0060] From FIGS. 9a and 9b, it can be seen that when a tube length of 100 mm is used, the proposed solution can measure at least a bend of the tube 130 from A = 1 mm to A = 3 mm. Also, from FIGS. 10a and 10b, it can be seen that a bend of the tube 130 of at least A = 2 mm to A = 4 mm can be measured by using a tube length of 150 mm. Accordingly, the signal-to-noise ratios at the “on” and “off” positions have values of 33.6 dB and 30.4 dB, respectively. Thus, this signal can be clearly distinguished from the background noise of the photodiode 170 and the light source 100, for example, the laser source 100. To demonstrate reproducibility, tests were performed with 1000 (thousand) simulated switch cycles for a tube length of 100 mm and for A = 2 mm and B = 1 mm. The results are shown in FIG. 11. That is, FIG. 11 shows the test with 1000 simulated switch cycles for a tube length of 100 mm with A = 2 mm and B = 1 mm. As a result of the 1000-cycle test, the measurement setup was environmentally stable over 5 hours. Also, the voltage at the “off” position (starting point of vector A) had a very accurate value of 11430 μV + / - 25 μV, and the voltage at the “on” position (end point of vector B) was 5943 μV + / - 85 μV. These results can be extended to vector A and vector B between 0…4 mm. The force required to impose a bend in the range of 0…4 mm is in the range of 0 to XN for the 100 mm tube 130 and in the range of 0 to xN for the 150 mm tube 130.

[0061] This solution provides an improved sensing device for a high voltage disconnect switch. For example, a sensing device for a high voltage disconnect switch is provided that enables accurate results and / or enables reliable monitoring of a high voltage disconnect switch. Further, predictive maintenance is also made possible by using the proposed solution.

[0062] In an energy system, it is necessary to achieve the stability of the power grid in order to address future challenges. This is, for example, to support the peak of future energy consumption by integrating renewable energy sources into the power grid and coupling electromobility to the power grid, although the production pattern is not plannable. Therefore, the digitization of substations by smart sensors is inevitable. These sensors need to be compatible with the strong electric and magnetic fields in the substation. The fiber optic technology used in the sensing device 10 disclosed in this specification enables the operation of such sensors based on optical principles while avoiding interference between the environmental electric and magnetic fields. By realizing the sensing itself with optical fibers, there is an advantage that the measured signal can be directly transmitted in an optical fiber network to a reading unit that can be located up to several kilometers away from the target point.

Claims

1. A sensing device (10) for a high-voltage cut-off switch (20), wherein the sensing device (10) comprises a first optical fiber (110) configured to receive light from a light source (100) and to guide the light, an optical collimator (120) coupled to the first optical fiber (110) for receiving the light guided into the first optical fiber (110) and configured to collimate the light into a collimated light beam, a bendable optical component (130) configured and arranged to bend in accordance with the switching state of the high-voltage cut-off switch (20), thereby affecting the collimated light beam, the bendable optical component (130) being coupled to the optical collimator (120) for receiving the collimated light beam and configured to guide the collimated light beam, and a derivation unit (160) configured to derive information regarding the switching state of the high-voltage cut-off switch (20) based on the collimated light beam, and comprising the sensing device (10).

2. The sensing device (10) according to claim 1, wherein the bending of the bendable optical component (130) bends in accordance with the switching state of the high-voltage cut-off switch (20) and changes the optical characteristics of the collimated light beam.

3. The collimator (120) is coupled to the first end of the flexible optical component (130), and the sensing device (10) further includes a focusing optical system (140) and a second optical fiber (150). The focusing optical system (140) is coupled to the second end of the flexible optical component (130) to receive the collimated light beam guided into the flexible optical component (130), and is coupled to the second optical fiber (150). The focusing optical system (140) is configured to focus the collimated light beam onto the second optical fiber (150). The second optical fiber (150) is configured to guide the focused light. The extraction unit (160) is coupled to the second optical fiber (150) to receive the focused light. The extraction unit (160) is configured to derive the information regarding the switching state of the high-voltage cut-off switch (20) based on the received focused light. The sensing device (10) according to claim 1 or 2.

4. The collimator (120) is coupled to the first end of the flexible optical component (130), and the sensing device (10) further includes a mirror ring component (190) and a focusing optical system (120). The mirror ring component (190) is coupled to the second end of the flexible optical component (130) to reflect the collimated light beam back to the first end of the flexible optical component (130). The focusing optical system (120) is coupled to the first end of the flexible optical component (130) to receive the reflected and collimated light guided into the flexible optical component (130), and is coupled to the first optical fiber (110). The focusing optical system (120) is configured to focus the reflected and collimated light beam onto the first optical fiber (110). The first optical fiber (110) is configured to guide the focused light. The extraction unit (160) is coupled to the first optical fiber (110) to receive the focused light. The extraction unit (160) is configured to extract information regarding the switching state of the high-voltage cut-off switch (20) based on the received focused light, and the optical collimator (120) and the focusing optical system (120) are configured as the same lens component. The sensing device (10) according to claim 1 or 2.

5. The extraction unit (160) includes a conversion component (170) configured to convert the received light into at least one voltage value, and a monitoring component (180) configured to determine the switching state of the high-voltage cut-off switch (20) based on the at least one voltage value. The sensing device (10) according to any one of claims 1 to 4.

6. The monitoring component (180) is configured to determine the degree of bending of the bendable optical component (130) based on the at least one voltage, and to determine the switching state of the high-voltage cut-off switch (20) based on the degree of bending of the bendable optical component (130). The sensing device (10) according to claim 5.

7. The monitoring component (180) is configured to continuously or repeatedly determine the switching state of the high-voltage cut-off switch (20). The sensing device (10) according to claim 5 or 6.

8. The sensing device (10) further includes a first adapter (125), and the first adapter (125) is disposed between the optical collimator (120) and the bendable optical component (130). The optical collimator (120) is attached to a first side surface of the first adapter (125), and the bendable optical component (130) is attached to a second side surface of the first adapter (125). The sensing device (10) according to any one of claims 1 to 7.

9. One end of the bendable optical component (130) is fixed, and the other end is freely bendable. The sensing device (10) according to any one of claims 1 to 8.

10. The bendable optical component (130) includes an optical tube, a cylindrical optical fiber having a tapered portion, or a pair of optical fiber ends coupled on a flexible substrate, or is configured as a pair of optical fiber ends coupled on an optical tube, a cylindrical optical fiber having a tapered portion, or a flexible substrate. The sensing device (10) according to any one of claims 1 to 9.

11. Comprising the sensing device (10) according to any one of claims 1 to 10. High voltage cut-off switch (20).

12. The high voltage cut-off switch (20) includes a switch arm (200) configured to deform when the switching state of the high voltage cut-off switch (20) changes. The sensing device (10) is coupled to the switch arm (200) such that deformation of the switch arm (200) causes bending of the bendable optical component (130). The high voltage cut-off switch (20) according to claim 11.

13. The high-voltage disconnect switch (20) includes a braking closing disconnect switch, a BCDS, a center brake disconnect switch, a double break disconnect switch, a vertical break disconnect switch, a pantograph disconnect switch, a semi-pantograph disconnect switch, or a neat type disconnect switch, or is configured as a braking closing disconnect switch, a BCDS, a center brake disconnect switch, a double break disconnect switch, a vertical break disconnect switch, a pantograph disconnect switch, a semi-pantograph disconnect switch, or a neat type disconnect switch. The high-voltage disconnect switch (20) according to claim 11 or 12.

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