Fiber optic underwater sensor units and related methods

Description

Submarine Fiber Optic Sensor Units and Related Methods Cross-reference to related filing applications

[0001] This application claims the benefit and priority of U.S. Provisional Patent Application No. 63 / 690,469, filed September 4, 2024, entitled “Subsea Measurement System”, the entire contents of which are incorporated herein by reference. Background

[0002] The embodiments disclosed herein refer generally to subsea sensor units and, in particular, to fiber optic sensor units for subsea systems and related methods.

[0003] Subsea systems may include equipment or devices that are positioned in the subsea environment (such as on the ocean floor). For example, some subsea systems may include subsea devices or subsystems that receive, generate, emit, control, adjust, utilize, etc. electrical energy during operation. It is typically desirable to monitor one or more operating parameters of such subsea devices. Thus, an operator of a subsea system may use sensors that measure or detect various parameters related to the operation of the subsea components during operation. Summary

[0004] Some embodiments disclosed herein relate to a system that includes a container that defines a chamber and that is configured to maintain the chamber at a controlled pressure in a submerged environment. Furthermore, the system includes an electrical connector set into the container that is configured Petition 870260053206, dated 02 / 06 / 2026, p. 7 / 60 2 / 36 to be electrically coupled to an underwater device. Furthermore, the system includes a fiber optic detection element positioned in the chamber and coupled to the electrical connector so that the fiber optic detection element is configured to detect a voltage or current from the underwater device through the electrical connector.

[0005] Some embodiments disclosed herein relate to a method that includes (a) lowering a container below the sea surface and into a submarine environment, the container defining a chamber that is maintained at a controlled pressure. Furthermore, the method includes connecting an electrical connector defined in the container to a submarine device. Additionally, the method includes detecting a voltage or current from the submarine device with a fiber optic sensing element that is positioned in the chamber.

[0006] Some embodiments disclosed herein relate to a system that includes a container that defines a chamber and that is configured to maintain the chamber at a controlled pressure in a subsea environment. Furthermore, the system includes one or more connectors defined in the container that are configured to be coupled to a subsea device. Additionally, the system includes one or more fiber optic sensing elements positioned in the chamber and coupled to the one or more connectors such that the one or more fiber optic sensing elements are configured to detect a plurality of electrical parameters of the subsea device through the one or more connectors. Petition 870260053206, dated 02 / 06 / 2026, p. 8 / 60 3 / 36 Brief description of the drawings

[0007] For a detailed description of various exemplary embodiments, reference will now be made to the attached drawings in which:

[0008] Figure 1 is a schematic diagram of a submarine system that includes a submarine fiber optic sensor unit according to some embodiments disclosed herein;

[0009] Figure 2 is a schematic diagram of the submarine system which includes another fiber optic sensor unit according to some embodiments disclosed herein;

[0010] Figure 3 is a schematic diagram of an offshore wind turbine system that includes one or more fiber optic sensor units according to some embodiments disclosed herein;

[0011] Figure 4 is a schematic diagram of a fiber optic sensor unit that can be used in the system of Figure 3 according to some embodiments disclosed herein; and

[0012] Figure 5 is a flow diagram of a method for measuring one or more parameters by using a submarine fiber optic sensor unit according to some embodiments disclosed herein. Detailed description

[0013] A subsea system may include equipment or devices that are configured to receive, generate, emit, control, adjust, utilize, etc. electrical power during operation. Operators of such subsea systems may use sensors to measure or detect one or more operating parameters of the subsea devices. However, such sensors may typically also use electrical power to operate. As a result, the inclusion of these sensors Petition 870260053206, dated 02 / 06 / 2026, page 9 / 60 An additional 4 / 36 may involve the installation of additional electrical infrastructure, which adds complexity, expense, and potential points of failure to the subsea system.

[0014] Consequently, the embodiments disclosed herein relate to fiber optic subsea sensor units that are configured to passively measure or detect one or more operational parameters of a subsea device during operation. In some embodiments, the fiber optic sensor units may be configured to measure one or more operating parameters of the subsea device by using light signals and reflections thereof. In some embodiments, the fiber optic measurement assemblies may include one or more fiber Bragg gratings (FBGs) that are configured to detect one or more operating parameters. However, such FBGs may be sensitive to forces that alter the distance between the gratings (such as pressure, mechanical stress, temperature, etc.). Some of these forces may be a characteristic of the subsea environment in which the fiber optic subsea sensor units are deployed.Consequently, the embodiments of the fiber optic submarine sensor units disclosed herein can be configured to take into account the effects of such environmental forces, so that accurate measurements can be obtained during operation. Thus, through the use of the embodiments disclosed herein, one or more operating parameters of a submarine device can be measured accurately and passively during operation.

[0015] Figure 1 shows a system 10 including a submarine fiber optic sensor unit 100 according to some embodiments. The system 10 may include a Petition 870260053206, dated 02 / 06 / 2026, page 10 / 60 5 / 36 device 12 that is positioned in a submarine environment 5 that is below the sea surface 4 and on or above the ocean floor 6. Thus, the device 12 may be referred to in the present invention as a “submarine device”. The device 12 may comprise one or more electrical components 14 that are configured to provide, enhance or facilitate one or more functions of the device 12 during operation. For example, the one or more electrical components 14 (which are collectively illustrated by a single box in Figure 1 in order to simplify the drawings) may include wiring, circuits, controllers, transformers, windings, switches, sensors, actuators, distribution panels, circuit boards, other electronic components or combinations thereof.In some embodiments, device 12 comprises a submarine power substation or an electrical transformer, and the electrical component(s) 14 may comprise various electronic components to facilitate the function of such device.

[0016] The submarine fiber optic sensor unit 100 (or “sensor unit 100”) may include a fiber optic sensing element 102. The fiber optic sensing element 102 may comprise a fiber optic cable (or multiple fiber optic cables), fiber optic connectors, other fiber optic elements, or combinations thereof. In the embodiment illustrated in Figure 1, the fiber optic sensing element 102 comprises a fiber optic cable extending to (or adjacent to) a device enclosure 12.

[0017] One or more FBGs 104 are defined or coupled to the fiber optic sensing element 102. In some Petition 870260053206, dated 02 / 06 / 2026, p. 11 / 60 In 6 / 36 embodiments, the FBGs 104 may comprise dielectric mirrors that are bonded to the optical fiber sensing element 102. When the FBGs 104 are illuminated, they reflect light within a defined wavelength bandwidth. Furthermore, the mechanical stress (such as expansive or compressive mechanical stress) that is applied to the FBGs 104 may alter the wavelength of the reflected light. The reflected light may be referred to in the present invention as a “response reflection”. These changes in wavelength may be measured to determine the mechanical stress being applied to the FBG 104 (or an indicative value thereof, as described herein). In addition, the FBGs 104 may also be temperature sensitive where the temperature of the FBGs can also induce mechanical stress on the same, which again can be measured through the reflected response wavelength as previously described. This measured mechanical stress can then be converted back to the temperature applied to the FBG 104 during operation. Furthermore, due to the fact that an FBG is pressure-sensitive, in some embodiments, one or more of the FBGs 104 (or one or more FBGs 104 in another sensor unit 100) can be configured to measure a pressure, such as a differential pressure applied to a component, chamber, or other specific portion of the device 12 (or other device).

[0018] In some embodiments, the fiber optic element 102 may comprise a single fiber optic element, and the FBGs 104 may be coupled and spaced along the single fiber optic element. In at least some of these embodiments, the FBGs 104 may be configured to reflect different wavelengths of light so that each FBG Petition 870260053206, dated 02 / 06 / 2026, p. 12 / 60 7 / 36 104 can be interrogated and collected separately along the single optical fiber element 102 during operation. The use of separate wavelengths of light to interrogate FBGs 104 is called wavelength division multiplexing (WBM). In some embodiments, the optical fiber element 102 may comprise a plurality of optical fiber elements, and each of the optical fiber elements is coupled to a corresponding FBG among the FBGs 104. Thus, the FBGs 104 can be interrogated and collected separately by routing a light signal through the corresponding optical fiber detection element.In some embodiments, even if a single fiber optic detection element 102 is used, the single fiber optic detection element can be coupled to a suitable controller (e.g., controller 30 described in more detail in the present invention) with a plurality (such as two) of fiber optic cables in order to provide redundancy to the connection in case of damage, wear or other loss of connectivity.

[0019] In the embodiment illustrated in Figure 1, the sensor unit 100 can be specifically configured to measure an electric current and a voltage associated with the electrical components 14 (or at least some of the electrical components 14). Specifically, the sensor unit 100 may include or be coupled to a current transformer 108 that is electrically coupled to the electrical components 14 (or at least some of the electrical components 14). During operation, an electric current in the electrical components 14 can induce a corresponding (as a proportional) electric current (as a current Petition 870260053206, dated 02 / 06 / 2026, page 13 / 60 8 / 36 alternating current (AC) in the current transformer 108. A resistor 110 (which may be called a “load resistor”) may be coupled to or included in the current transformer 108 to convert the induced electrical current into a voltage.

[0020] In addition, the fiber optic sensor unit 100 may include or be coupled to a voltage transformer. 112 which is also electrically coupled to electrical components 14 (or at least some of the electrical components) 14). During operation, a voltage in the electrical components 14 can induce a corresponding (and proportional) voltage in the voltage transformer 112.

[0021] In addition, the sensor unit 100 may include one or more piezoelectric devices 106. Specifically, a first piezoelectric device 106 may be coupled to (as between) the current transformer 108 and a first of the FBGs 104, and a second piezoelectric device 106 may be coupled to (as between) the voltage transformer 112 and a second of the FBGs 104. The piezoelectric elements may be configured to expand and compress (or contract) in response to an applied voltage. Thus, during operation, a voltage that is conducted to the piezoelectric devices 106 (as through the current transformer 108 or the voltage transformer 112) may cause the piezoelectric devices 106 to expand or contract and thus induce or adjust a voltage that is applied to the FBGs 104.Thus, in this way, the fiber optic detection element 102 (which includes the FBGs 104) can be configured to detect a voltage or current from the device 12 and. Petition 870260053206, dated 02 / 06 / 2026, page 14 / 60 9 / 36 particularly the electrical components 14 of the device 12.

[0022] A controller 30 can be coupled (as communicatively coupled) to the sensor unit 100. In some embodiments, the controller 30 can be configured to control one or more aspects of the sensor unit 100 during operation. For example, the controller 30 can be configured to interrogate the sensor unit 100, receive response reflection(s) back from the sensor unit 100, and interpret the response reflection(s) in order to determine the underlying measured or detected parameter of the electrical components 14 as previously described (e.g., as a voltage, a current, a temperature, etc.).

[0023] The controller 30 may be located remotely in relation to the device 12 and the sensor unit 100. More specifically, in some embodiments, the controller 30 may be located outside the subsea environment 5. For example, in some embodiments, the controller 30 may be located on a support structure 20 that is positioned on the sea surface 4. The support structure 20 may comprise any suitable vessel or other structure, such as a platform, a floating production, storage, and offloading unit (FPSO). Alternatively, in some embodiments, the controller 30 may be located on or within a land-based installation.

[0024] In some embodiments, the controller 30 may comprise a computing device or a collection of computing devices that are communicating. Petition 870260053206, dated 02 / 06 / 2026, page 15 / 60 10 / 36 coupled to each other. In general, controller 30 may comprise a processor 32 and a memory 34.

[0025] Processor 32 may comprise any suitable processing device, such as a microcontroller, a central processing unit (CPU), a graphics processing unit (GPU), a timing controller (TCON), or a scraper unit. Processor 32 executes computer-readable instructions 36 stored in memory 34, thus causing processor 32 to perform some or all of the actions here attributed to controller 30. In general, processor 32 fetches, decodes, and executes instructions. In addition, processor 32 may also perform other actions, such as making determinations, detecting conditions or values, etc., and communicating signals. If processor 32 (or more broadly, controller 30) assists another component in performing a function, then it can be said that processor 32 (or more broadly, controller 30) causes the component to perform the function.

[0026] Memory 34 may comprise volatile storage (e.g., random access memory (RAM)), non-volatile storage (e.g., flash storage, read-only memory (ROM), etc.) or combinations of volatile and non-volatile storage. Data read from or written by the processor 32 when executing computer-readable instructions 36 may also be stored in memory 34. In addition, data collected by the sensor unit 100 may also be stored in memory 34. Memory 34 may comprise “computer-readable media not Petition 870260053206, dated 02 / 06 / 2026, page 16 / 60 11 / 36 transient”, where the term “non-transient” does not encompass transient propagation signals.

[0027] As used herein, “a processor,” “at least one processor,” or “one or more processors” generally refers to a single processor configured to perform one or more operations or to multiple processors configured to collectively perform one or more operations. In the case of multiple processors, the performance of one or more operations may be divided among different processors, although a single processor may perform multiple operations and multiple processors may collectively perform a single operation. Similarly, “a memory,” “at least one memory,” or “one or more memories” generally refers to a single memory configured to store data and / or instructions or to multiple memories configured to collectively store data and / or instructions.

[0028] Controller 30 may comprise a dedicated controller for controlling sensor unit 100. Alternatively, controller 30 may be included as part of a general or master controller for system 10. In one or more embodiments, controller 30 may be incorporated as a single unit or device. Alternatively, in one or more embodiments, controller 30 may be incorporated as a plurality of devices that are communicatively coupled to each other and potentially spaced remotely from each other.

[0029] The controller 30 may include or be coupled to a suitable human-machine interface (HMI) 35 that may allow personnel to interact with the Petition 870260053206, dated 02 / 06 / 2026, p. 17 / 60 12 / 36 controller 30. For example, the HMI 35 can be used to communicate outputs (such as measurement outputs) to a user and / or to receive user input during operation. In some embodiments, the HMI 35 may comprise a keyboard, a display (including a touch-sensitive display), a mouse, a speaker, other interface devices, or combinations thereof.

[0030] The controller 30 can be coupled to (or may include) a suitable interrogator 22 which is additionally coupled to the fiber optic detection element 102. For example, the fiber optic detection element 102, such as one or more fiber optic cables or lines, may be extended from the device 12 to the sea surface 4, where it is coupled (via suitable connectors or systems) to the interrogator 22. The interrogator 22 may comprise any suitable device, system, assembly, etc. that is configured to generate light signals that are directed to the fiber optic detection element 102 during operation.Furthermore, interrogator 22 (or controller 30 or other devices coupled to it) can be configured to receive the response reflection(s) back from the FBGs 104 of the fiber optic detection element 102 which can then be analyzed (e.g., by controller 30) to determine the underlying parameter(s) as previously described (such as voltage, current, temperature, etc.).

[0031] During operation, the controller 30 can direct the interrogator 22 to emit a desired interrogation signal to the fiber optic detection element 102. The interrogation signal can be of a Petition 870260053206, dated 02 / 06 / 2026, page 18 / 60 13 / 36 specific wavelength of light that is configured to reflect within a desired FBG among the FBGs 104. For example, the interrogation signal can be configured to reflect off the FBG 104 that is coupled to the current transformer 108 through the corresponding piezoelectric device 106. The piezoelectric device 106 can induce a mechanical stress in the FBG 104 that is characteristic or indicative of a current that is induced in the current transformer 108 by the electrical components 14 as previously described. This mechanical stress can alter the wavelength of the response reflection that is received by the controller 30 (either directly, or through the interrogator 22 and / or other device or system). The controller 30 can be configured to determine the underlying current being induced in the current transformer 108 based on one or more parameters (such as wavelength) of the response reflection.

[0032] A similar procedure can be performed to determine the voltage that is induced in the voltage transformer 112 during operation. However, in this case, the controller 30 can direct the interrogator 22 to emit a desired interrogation signal at a different wavelength - that is, a wavelength that is configured to be reflected by the FBG 104 coupled to the voltage transformer 112 through the corresponding piezoelectric device 106.

[0033] In some embodiments, the fiber optic detection element 102 and particularly the FBGs 104 may be exposed to the pressure of the underwater environment 5. This environmental pressure may induce additional mechanical stress on the FBGs. Petition 870260053206, dated 02 / 06 / 2026, page 19 / 60 14 / 36 104 which may frustrate the accuracy of the mechanical stress-based measurements described above. As a result, in some embodiments, the controller 30 can be configured to apply a calibration offset to the measurements received through the sensor unit 100. In some embodiments, the calibration offset can be determined based on the pressure of the underwater environment 5 surrounding the sensor unit 100. Because the pressure of the underwater environment 5 is directly related to depth (i.e., depth below the sea surface 4), the calibration offset can also be a function of the depth of the sensor unit 100. Thus, by applying the calibration offset, the controller 30 can accurately determine one or more parameters that are measured or detected by the sensor unit 100 (such as a current or voltage of electrical components 14) as previously described.

[0034] In some embodiments, the calibration offset may be predetermined by laboratory or other controlled testing. For example, a pressurized tank may be used to determine the appropriate calibration offset for different ambient pressures, and these predetermined offset calibrations may then be used (e.g., by the controller 30) to account for the mechanical stress on the FBGs 104 due to the subsea ambient pressure 5 as previously described.

[0035] In some embodiments, the fiber optic sensing element 102 may include at least one FBG 104 that is configured to measure or detect a temperature of or associated with electrical components 14, such as a winding Petition 870260053206, dated 02 / 06 / 2026, page 20 / 60 15 / 36 electrical, a connection or other device or structure of the electrical component(s) 14. For example, as previously described, the device 12 may comprise an electrical transformer, which may include transformer oil. In some embodiments, at least one FBG 104 of the fiber optic sensing element may be positioned in, or otherwise in thermal contact with, the transformer oil of the device 12, so that the thermal energy of the transformer oil is transferred to the FBG 104 to thereby cause a resulting mechanical stress thereon. Thus, an FBG 104 that is configured to measure a component, ambient, etc. temperature may not include or be coupled to a piezoelectric device (such as the piezoelectric devices 106 previously described).During operation, controller 30 can interpret the response reflection of FBG 104 to determine the underlying temperature of the transformer oil based on one or more parameters (such as wavelength) of the response reflection as previously described.

[0036] Figure 2 shows system 10 from Figure 1 with another submarine fiber optic sensor unit 150 according to some embodiments. The fiber optic sensor unit 150 (or “sensor unit 150”) may share several components with the sensor unit 100 previously described (Figure 1). Thus, when describing sensor unit 150, the same reference numbers are used to refer to components of sensor unit 150 that are shared with sensor unit 100. Furthermore, the following description will focus on the characteristics of sensor unit 150 that are different from sensor unit 100 (Figure 1). Petition 870260053206, dated 02 / 06 / 2026, p. 21 / 60 16 / 36

[0037] In particular, the sensor unit 150 may include the fiber optic sensing element 102, FBG(s) 104, piezoelectric devices 106 and transformers 108, 112 as previously described for the sensor unit 100. However, the sensor unit 150 may additionally include a container 152 that is configured to enclose and contain one or more components of the sensor unit 150 (such as fiber optic sensing element 102, FBGs 104, piezoelectric devices 106, etc.). The container 152 may be configured to shield or protect the sensor unit 150 (or at least one or more components thereof) from the pressure of the subsea environment 5.

[0038] The container 152 may comprise a pressure vessel (such as a tank, a bottle, a cabinet or other enclosure) that defines a chamber 154 therein. The container 152 may be configured to maintain a controlled pressure in chamber 154 that may be lower than the pressure of the subsea environment 5. For example, in some embodiments, chamber 154 may be configured to maintain a controlled pressure of about 1 standard atmosphere (atm) to enable the FBGs 104 to react to the mechanical stress induced from the piezoelectric device 106 in a manner similar to that seen on the sea surface or on land. Thus, by maintaining chamber 154 at a pressure of about 1 atm, the sensor unit 150 may be calibrated outside the subsea environment under ambient conditions, prior to installation of the sensor unit 150 in the subsea environment 5.

[0039] In some embodiments, chamber 154 may be filled with air. However, due to the fact that air can expand or contract due to temperature differences, in some embodiments, chamber 154 may be Petition 870260053206, dated 02 / 06 / 2026, p. 22 / 60 17 / 36 filled with a gas, liquid, or other suitable medium that may be less sensitive to pressure changes at ambient temperature. For example, in some embodiments, chamber 154 may be filled with nitrogen (N2).

[0040] In some embodiments, the fiber optic sensing element 102 can be coupled to the controller 30 via a fiber optic cable 160 extending from the container 152 to the sea surface 4. The fiber optic cable 160 can be coupled to the fiber optic sensing element 102 via a fiber connector 156 that is set into a wall or other surface of the container 152. The fiber connector 156 can comprise any suitable fiber optic connector that can couple the fiber optic cable 160 to the fiber optic sensing element 102 so that light signals can pass through it without signal degradation or with minimal signal degradation. In some embodiments, the fiber optic detection element 102 may comprise a fiber optic cable extending through the vessel wall 152 and upwards towards the sea surface 4, so that the separate fiber connector 156 and fiber optic cable 160 may be omitted.

[0041] In some embodiments, each of the FBGs 104 can be coupled to the electrical component(s) 14 of the device 12 via electrical connectors 158 that are defined in the container 152 (such as on a wall or other surface). The electrical connectors 158 may comprise any suitable connector or other interface that is configured to electrically couple two components to each other. For example, in some embodiments, the electrical connectors 158 may comprise wet-connectable electrical connectors that Petition 870260053206, dated 02 / 06 / 2026, page 23 / 60 18 / 36 are configured to establish an electrical connection between the sensor unit 150 and the electrical component(s) 14 in the subsea environment 5. Without limiting this or any other theory, the use of so-called wet-connectable connectors (or other readily disconnectable connectors) for the electrical connectors 158 may allow the container 152 to be disconnected from the device 12 and pulled or recovered to the sea surface 4 (as in the case of a failure of the sensor unit 100). In some embodiments, the fiber connector 156 may also comprise a wet-connectable connector that is configured to be connected or disconnected in the subsea environment 5.

[0042] In some embodiments, the electrical connectors 158 may be included or integrated into a mechanical connection between the container 152 and an external surface, support or other structure of (or associated with) the device 12. Specifically, in some embodiments, the electrical connectors 158 may be included or integrated into one or more bulkhead connectors 159 that are configured to attach the container 152 to the device 12 (or some surface, support or other structure of or associated with it).

[0043] As shown in Figure 2, in some embodiments, at least a portion of the transformers 108, 112 may be positioned or incorporated into the device 12, or may at least be positioned outside the container 152. Specifically, in some embodiments, the transformers 108, 112 may be coupled between the electrical connectors 158 and the electrical component(s) 14 and potentially within a body, enclosure, frame, etc. of the device 12. Without limiting to this or any other theory, minimizing the Petition 870260053206, dated 02 / 06 / 2026, page 24 / 60 19 / 36 The number of components within the container 152 may allow the size of the chamber 154 to be reduced. A smaller chamber 154 can be more easily maintained at the lower pressure (e.g., about 1 atm in some embodiments as previously described) at the substantially higher pressure of the underwater environment 5. However, it should be recognized that the transformers 108, 112 (or at least some components thereof) may be positioned in the chamber 154 together with the fiber optic sensing element 102 and the FBGs 104. For example, as shown in Figure 2, the load resistor 110 of the current transformer 108 is positioned within the chamber 154 and electrically coupled between the corresponding electrical connector 158 and the piezoelectric device 106.

[0044] The operations with sensor unit 150 are substantially the same as those previously described for sensor unit 100, so this description will not be fully repeated in the interest of brevity. However, during operation, due to the fact that sensor unit 150 includes container 152, the FBGs 104 do not experience increased mechanical stress due to increased underwater ambient pressures 5. As a result, the controller 30 may not apply a calibration offset to the measurements received through sensor unit 150, as was described for sensor unit 100 (Figure 1).

[0045] Now with reference to Figure 3, an offshore wind turbine system 200 is shown which includes one or more fiber optic sensor units 250, 252 according to some embodiments. The offshore wind turbine system 200 (“system 200”) may include one or more (such as one or Petition 870260053206, dated 02 / 06 / 2026, page 25 / 60 20 / 36 a plurality of) offshore wind turbines 202 that are configured to generate electrical energy based on wind flowing through and / or over the sea surface 4. The offshore wind turbines 202 (“turbines 202”) can each be electrically coupled to the subsea device 12. As shown in Figure 3, the device 12 can be configured as a subsea electrical transformer or an electrical substation that is configured to receive (and potentially transform or convert) electrical energy generated by the turbines 202. For example, the electrical component(s) 14 of the device 12 can be configured to convert the electrical energy generated by the turbines 202 for distribution to a transmission line 204 (or other suitable infrastructure or location).

[0046] Furthermore, as shown in Figure 3, the system 200 may include one or more (as a plurality of) fiber optic sensor units 250, 252 that are configured to measure or detect one or more parameters of (or associated with) device 12, turbines 202, etc. The fiber optic sensor units 250, 252 (or “sensor units 250, 252”) may be configured as one or more of the sensor units 100, 150 (Figures 1, 2, respectively) as previously described. For example, sensor units 250 may be configured as sensor unit 150 and therefore include containers 152 that define chambers 154 (Figure 2) that are maintained at a controlled pressure as previously described. However, it should be recognized that one or more of the 250 sensor units can be configured as the 100 sensor unit (Figure 1) described previously. Petition 870260053206, dated 02 / 06 / 2026, page 26 / 60 21 / 36

[0047] Each of the sensor units 250 can be electrically coupled to the electrical component(s) 14 of the device 12. More specifically, each of the sensor units 250 can be electrically coupled to a corresponding turbine among the turbines 202 and to the electrical component(s) 14. During operation, the sensor units 250 can be configured to measure or detect one or more parameters associated with the electrical energy generated by the turbines 202, such as a current, a voltage, a temperature, etc. The sensor units 250 can be configured to measure or detect the one or more parameters in the manner previously described above for sensor unit 150 (or sensor unit 100) as previously described.

[0048] Although the sensor units 250 are shown as being connected to the device 12, it should be recognized that one or more of the sensor units 250 may be coupled to other components or otherwise positioned alternately in the system 200 in some embodiments. For example, in some embodiments, one or more of the sensor units 250 may be coupled to the corresponding turbines among the turbines 202 or may be placed independently in the subsea environment 5, in a position adjacent to the turbines 202 and / or to the device 12.

[0049] In some embodiments, some sensor units 250 may be coupled to device 12 as shown in Figure 3, and additional sensor units may be included. 250 which are coupled to turbines 202 (or between turbines 202 and the device as previously described). Without limiting itself to this or any other theory, the inclusion of additional and / or alternatively placed sensor units Petition 870260053206, dated 02 / 06 / 2026, page 27 / 60 22 / 36 250 can allow sensor units to measure or detect one or more parameters (such as current, voltage, temperature, etc.) at various points in the system 200. These additional measurements can allow for better analysis of the electrical performance of the system 200 and can allow personnel (or controllers or other computing devices) to determine the location and nature of a detected fault (such as an electrical short circuit, a disconnection, etc.) within the system 200 during operation.

[0050] In addition, system 200 may include one or more additional sensor units 252 that are specifically configured to measure the temperature of one or more components of system 200. More particularly, a sensor unit 252 may be coupled to device 12 so that the sensor unit 252 can be configured to measure or detect a temperature associated with device 12. When device 12 is configured as a submarine electrical transformer as previously described, device 12 may include transformer oil to electrically insulate and cool one or more internal components thereof during operation. In some embodiments, the sensor unit 252 may be configured to measure or detect the temperature of the transformer oil during operation.

[0051] For example, with reference to Figure 4, sensor unit 252 may include a container 272 that defines a pressure-controlled chamber 274 as described previously for container 152 of sensor unit 150 (Figure 2). As described previously for chamber 154 of container 152 in Figure 2, chamber 274 may be maintained at around 1 atm; however, other pressures are contemplated. Petition 870260053206, dated 02 / 06 / 2026, p. 28 / 60 23 / 36

[0052] In addition, the sensor unit 252 includes a fiber optic sensor element 102 and an FBG 104 positioned in the chamber 274 in a manner similar to that described for the sensor unit 150 (Figure 2). The fiber optic sensing element 102 can be coupled to a fiber optic cable 262 for communication with other systems or devices (such as the controller 30) via a fiber connector 156 as previously described for the sensor unit 150 (Figure 2). In some embodiments, the fiber optic sensing element 102 can extend through the wall of the container 272 as previously described for embodiments of the sensor unit 150 (Figure 2).As shown in Figure 4, in some embodiments, the sensor unit 252 may omit the other components of the sensor unit embodiments 100, 150 that are specifically configured to measure or detect electrical parameters, such as piezoelectric devices 106, transformers 108, 112, etc.

[0053] With reference now to Figures 2 and 3, the container 272 of the sensor unit 250 can be positioned in, or otherwise in contact with, the transformer oil of the device 12 (Figure 3) during operation. As a result of thermal contact between the container 272 and the transformer oil, the container 272 and the chamber 274 set within it may eventually have the same temperature as the transformer oil. As a result, the FBG 104 can detect this temperature based on the resulting characteristic mechanical stress that is applied to the FBG as previously described.

[0054] In some embodiments, chamber 274 may be at least partially filled with a fluid that is Petition 870260053206, dated 02 / 06 / 2026, p. 29 / 60 24 / 36 configured to enhance thermal heat transfer with transformer oil at least partially surrounding container 272. For example, in some embodiments, chamber 274 may be at least partially filled with water, glycol, oil, other suitable fluids, or combinations thereof.

[0055] Referring specifically again to Figure 3, the sensor units 250, 252 can be communicatively coupled to the controller 30 and the interrogator 22 via one or more fiber optic cables 262 as described previously. In some embodiments, each sensor unit 250, 252 may be coupled to a corresponding fiber optic cable 262 that is routed to the subsea environment 5. In some embodiments, one or more fiber optic cables 262 may be at least partially routed to (or through) the subsea environment 5 in a cable bundle 260. In some embodiments, the cable bundle 260 may be a cable bundle dedicated to routing fiber optic cables 262 to the sensor units 250, 252 or it may be a cable bundle that includes or is associated with one or more other cables, lines, conduits that are routed through the subsea environment 5 to the system 200.For example, in some embodiments, one or more additional cables may be included in bundle 260, such as electrical cables, fiber optic cables or conduits, which are configured to provide communication signals, power, fluid, etc. to one or more other system components 200, such as turbines 202, device 12, etc. Thus, in some embodiments, fiber optic cables 262 for communication with sensor units 250, 252 may be at least partially integrated into another. Petition 870260053206, dated 02 / 06 / 2026, p. 30 / 60 25 / 36 infrastructure (including fiber optic cabling) of the 200 system.

[0056] With reference now to Figure 5, a method 300 for measuring one or more parameters using a submarine fiber optic sensor unit is shown according to some embodiments disclosed herein. In some embodiments, method 300 can be performed using one or more embodiments of the systems 10, 200 described herein. Thus, in describing the characteristics of method 300, continuous reference is made to Figures 1 to 4. However, it should be recognized that at least some embodiments of method 300 can be performed using systems that are different from systems 10, 200 in at least some respects.

[0057] Method 300 involves lowering a container below a sea surface and into a subsea environment in block 302. The container defines a chamber that is maintained at a controlled pressure. For example, as previously described for sensor unit 150 shown in Figure 2, the container 152 of sensor unit 150 can be inserted into another subsea environment 5 and the container 152 is configured to maintain a controlled pressure (such as about 1 atm as previously described) which may be different (such as less than) the pressure of the surrounding subsea environment 5.

[0058] In addition, method 300 includes connecting an electrical connector defined in the container to a subsea device in block 304. For example, as previously described for sensor unit 150 shown in Figure 2, container 152 may include electrical connectors that are configured to connect sensor unit 100 to electrical component(s) 14 of subsea device 12. Petition 870260053206, dated 02 / 06 / 2026, page 31 / 60 26 / 36 In some embodiments, electrical connectors 158 may be included or incorporated into a bulkhead connector 159 that is configured to connect the container 152 to the outer surface of the device 12 (or other structure, frame, enclosure, etc. associated with the device 12).

[0059] In some embodiments, the electrical connector (e.g., electrical connectors 158) can be connected to the electrical component(s) (e.g., electrical component(s) 14) of the subsea device (e.g., subsea device 12) before the container is lowered below the sea surface, so that the container and the subsea device can be lowered below the sea surface together. Alternatively, in some embodiments, the electrical connector can be connected to the electrical component(s) of the subsea device after the container is lowered below sea level. For example, as previously described for the sensor unit 150 shown in Figure 2, the electrical connectors 156 may comprise a wet-attachable connector that can be constructed in the subsea environment 5.Thus, container 152 can be lowered into the underwater environment 5 and subsequently the electrical connectors 158 can be connected to the electrical component(s) 14, such as with a remotely operated or autonomous underwater vehicle, diver, etc.

[0060] In addition, method 300 includes detecting a voltage or current from the underwater device with a fiber optic detection element that is positioned in the chamber in block 306. As previously described for sensor units 100, 150, shown in Figures 1, 2, Petition 870260053206, dated 02 / 06 / 2026, page 32 / 60 27 / 36 respectively, a fiber optic sensing element 102 can detect a voltage or current in the electrical component(s) 14 of the device 12 based on a mechanical stress that is induced in one or more FBGs 104 defined in the fiber optic sensing element 102 by the voltage or current through piezoelectric devices 106. Thus, in some embodiments, a transformer (such as a voltage transformer 112 or current transformer 108) can be coupled between the piezoelectric devices 106 and the electrical component(s) 14 in order to transmit an induced voltage or current to the corresponding piezoelectric devices 106 based on the voltage or current being measured or detected in the electrical component(s) 14.

[0061] In some embodiments, a fiber optic submarine sensor unit (such as embodiments of fiber optic submarine sensor units 100, 150 described herein) may include multiple redundant FBGs 104 to measure one or more operating parameters of a submarine device. Without limiting this or any other theory, the use of multiple redundant FBGs 104 to measure the same operating parameter(s) may allow the fiber optic submarine sensor unit to continue to provide useful measurements in the event of a failure of one or more of the FBGs 104.

[0062] As explained above and reiterated below, the present disclosure includes, without limitation, the following Examples.

[0063] Example 1: A system comprising: a container that defines a chamber and that is configured to maintain the chamber at a controlled pressure in a submerged environment; an electrical connector defined in the container that is configured to be electrically coupled to a Petition 870260053206, dated 02 / 06 / 2026, p. 33 / 60 28 / 36 underwater device; and a fiber optic detection element positioned in the chamber and coupled to the electrical connector so that the fiber optic detection element is configured to detect a voltage or current from the underwater device through the electrical connector.

[0064] Example 2: The system of any of the Examples, where the fiber optic detection element includes a fiber Bragg grating (FBG).

[0065] Example 3: The system of any of the Examples further comprising a piezoelectric device coupled between the electrical connector and the FBG of the fiber optic sensing element, and the piezoelectric device is configured to induce a mechanical stress in the FBG in response to the voltage or current of the subsea device.

[0066] Example 4: The system of any of the Examples, wherein the FBG comprises a first FBG, the electrical connector comprises a first electrical connector and the piezoelectric device comprises a first piezoelectric device, wherein the fiber optic sensing element includes a second FBG and wherein the system further comprises: a second electrical connector defined in the container which is configured to be coupled to the subsea device or to another subsea device; and a second piezoelectric device which is coupled to the second electrical connector and to the second FBG such that the second piezoelectric device is configured to induce a mechanical stress in the second FBG in response to a second voltage or a second current from the subsea device or to another subsea device. Petition 870260053206, dated 02 / 06 / 2026, page 34 / 60 29 / 36

[0067] Example 5: The system from any of the Examples, where the controlled pressure is less than the pressure of the underwater environment.

[0068] Example 6: The system from any of the Examples, where the controlled chamber pressure is approximately 1 atmosphere (atm).

[0069] Example 7: The system of any of the Examples further comprising a controller which is communicatively coupled to the fiber optic sensing element, and the controller is configured to: emit an interrogation signal to the fiber optic sensing element; receive a response reflection from the FBG through the fiber optic sensing element; and determine a voltage or current value based on the response reflection.

[0070] Example 8: The system of any of the Examples, wherein the controller is at least partially positioned outside the underwater environment and the controller is coupled to the fiber optic detection element via a fiber optic cable.

[0071] Example 9: The system of any of the Examples, wherein the underwater device comprises an underwater electrical transformer.

[0072] Example 10: The system of any of the Examples which additionally comprises: an offshore wind turbine that is configured to generate electrical power, and wherein the subsea electrical transformer is electrically coupled to the offshore wind turbine.

[0073] Example 11: The system of any of the Examples, wherein the electrical connector is incorporated into a connector Petition 870260053206, dated 02 / 06 / 2026, page 35 / 60 30 / 36 bulkhead that is configured to connect the vessel to an external surface of the subsea electrical transformer.

[0074] Example 12: The system of any of the Examples, wherein the electrical connector is a wet coupling connector that is configured to be disconnected when submerged to facilitate recovery of the vessel to the sea surface.

[0075] Example 13: The system of any of the Examples, wherein the submarine electrical transformer includes transformer oil, and wherein the system further comprises: a second container that is thermally coupled to the transformer oil; and a second fiber optic sensing element positioned in the second container that is configured to detect a temperature of the transformer oil.

[0076] Example 14: A method comprising: (a) lowering a container below the sea surface and into a submarine environment, the container defining a chamber that is maintained at a controlled pressure; (b) connecting an electrical connector defined in the container to a submarine device; and (c) detecting a voltage or current from the submarine device with a fiber optic sensing element that is positioned in the chamber.

[0077] Example 15: The method of any of the Examples, where (b) is executed before (a).

[0078] Example 16: The method of any of the Examples, where (b) is executed after (a).

[0079] Example 17: The method of any of the Examples, wherein (c) comprises: (c1) actuating a piezoelectric device positioned in the container by the use of voltage or current Petition 870260053206, dated 02 / 06 / 2026, p. 36 / 60 31 / 36 of the submarine device; and (c2) induce a mechanical stress in the fiber optic detection element with the piezoelectric device that is characteristic of the voltage or current.

[0080] Example 18: The method of any of the Examples, wherein (c2) additionally comprises inducing mechanical stress in a fiber Bragg grating (FBG) which is defined in the fiber optic sensing element.

[0081] Example 19: The method of any of the Examples further comprising: (d) emitting a question signal to the fiber optic detection element; (e) receiving a response reflection from the FBG through the fiber optic detection element; and (f) determining a voltage or current value based, at least in part, on the response reflection.

[0082] Example 20: The method of any of the Examples which further comprises: (g) generating the interrogation signal by use of a controller that is at least partially positioned above the sea surface; and (h) conducting the interrogation signal from the controller to the vessel via a fiber optic cable.

[0083] Example 21: The method of any of the Examples, wherein the subsea device comprises a subsea electrical transformer, and wherein the method further comprises: (i) generating electrical energy with an offshore wind turbine; and (j) conducting the electrical energy to the subsea electrical transformer, wherein the voltage or current is at least partially indicative of the electrical energy.

[0084] Example 22: The method of any of the Examples which additionally comprises: (k) detecting a temperature of a Petition 870260053206, dated 02 / 06 / 2026, page 37 / 60 32 / 36 transformer oil in the subsea electrical transformer by use of a second fiber optic sensing element that is positioned in a second container, the second container being thermally coupled to the transformer oil.

[0085] Example 23: A system comprising: a container that defines a chamber and that is configured to maintain the chamber at a controlled pressure in a subsea environment; one or more connectors defined in the container that are configured to be coupled to a subsea device; and one or more fiber optic sensing elements positioned in the chamber and coupled to the one or more connectors such that the one or more fiber optic sensing elements are configured to detect a plurality of electrical parameters of the subsea device through the one or more connectors.

[0086] Example 24: The system of any of the Examples, wherein the one or more fiber optic detection elements include a plurality of fiber Bragg gratings (FBGs) that are coupled to one or more connectors, and wherein each of the plurality of FBGs is configured to detect a corresponding electrical parameter from the plurality of electrical parameters across the one or more connectors.

[0087] Example 25: The system of any of the Examples further comprising a plurality of piezoelectric devices that are positioned in the chamber and coupled to the plurality of FBGs such that each of the plurality of piezoelectric devices is configured to induce a mechanical stress in a corresponding FBG of the plurality of FBGs that is indicative of the corresponding electrical parameter for the corresponding FBG. Petition 870260053206, dated 02 / 06 / 2026, pp. 38 / 60 33 / 36

[0088] Example 26: The system of any of the Examples further comprising a controller that is communicatively coupled to one or more fiber optic sensing elements, wherein the controller is configured to: emit interrogation signals to the one or more fiber optic sensing elements; receive response reflections from the plurality of FBGs through the one or more fiber optic sensing elements; and determine values ​​of the plurality of electrical parameters based, at least in part, on the response reflections.

[0089] Example 27: The system of any of the Examples, wherein the one or more fiber optic detection elements comprise a single fiber optic detection element, wherein the plurality of FBGs are positioned along the single fiber optic detection element within the chamber, and wherein the controller is configured to emit a first interrogation signal with a first wavelength to a first FBG among the plurality of FBGs through the single fiber optic detection element and is configured to emit a second interrogation signal with a second wavelength to a second FBG among the plurality of FBGs through the single fiber optic detection element.

[0090] Example 28: The system of any of the Examples, the plurality of electrical parameters comprising one or more voltages or currents of the subsea device.

[0091] Example 29: The system of any of the Examples further comprising: an offshore wind turbine that is configured to generate electrical power, and wherein the subsea device comprises a transformer. Petition 870260053206, dated 02 / 06 / 2026, pp. 39 / 60 34 / 36 subsea electric motor that is electrically coupled to an offshore wind turbine.

[0092] Example 30: The system of any of the Examples, wherein the submarine electrical transformer includes transformer oil, and wherein the system further comprises: a second container that is thermally coupled to the transformer oil; and a second fiber optic sensing element positioned in the second container that is configured to detect a temperature of the transformer oil.

[0093] The embodiments disclosed herein relate to subsea fiber optic sensor units that are configured to passively measure or detect one or more operational parameters of a subsea device during operation. In some embodiments, the fiber optic sensor units may be configured to measure one or more operating parameters of the subsea device by using light signals and reflections thereof. In some embodiments, the fiber optic measurement assemblies may include one or more FBGs that are configured to detect one or more operational parameters. However, such Fiber-optic gating (FBGs) can be sensitive to environmental forces that alter the distance between networks (such as pressure, mechanical stress, temperature, etc.). Consequently, the embodiments of the fiber-optic submarine sensor units disclosed herein can be configured to take into account the effects of such environmental forces, so that accurate measurements can be obtained during operation. Thus, through the use of the embodiments disclosed herein, one or more parameters of Petition 870260053206, dated 02 / 06 / 2026, pages 40 / 60 35 / 36 The functioning of an underwater device can be measured accurately and passively during operation.

[0094] The preceding discussion is directed to various embodiments. However, one skilled in the art will understand that the examples disclosed here have wide application and that the discussion of any embodiment is intended only to be illustrative of that embodiment and is not intended to suggest that the scope of the disclosure, including the claims, is limited to that embodiment.

[0095] The figures in the drawing are not necessarily to scale. Certain features and components in the present invention may be shown exaggerated to scale or in a relatively schematic way, and some details of conventional elements may not be shown in the interest of clarity and conciseness.

[0096] In the preceding discussion and claims, the terms including and comprising are used in an unlimited way and therefore should be interpreted as meaning including, but not limited to.... Furthermore, the term coupling or couples is intended to mean an indirect or direct connection. Thus, if a first device couples to a second device, this connection may be through a direct connection of the two devices, or through an indirect connection that is established through other devices, components, nodes and connections. Furthermore, as used herein, the terms axial and axially generally mean along or parallel to a given axis (e.g., the central axis of a body or a door), while the terms radial and radially generally mean perpendicular to the given axis. For example, an axial distance Petition 870260053206, dated 02 / 06 / 2026, page 41 / 60 36 / 36 refers to a distance measured along or parallel to the axis, and a radial distance means a distance measured perpendicular to the axis. Furthermore, when used herein (including in the claims), the words “about”, “generally”, “substantially”, “approximately” and the like, when used to refer to a stated value, mean within a range of plus or minus 10% of the stated value.

[0097] Although exemplary embodiments have been shown and described, modifications thereof may be made by one skilled in the art without departing from the scope or teachings of the present invention. The embodiments described herein are merely exemplary and are not limiting. Many variations and modifications of the systems, apparatus, and processes described herein are possible and fall within the scope of disclosure. Consequently, the scope of protection is not limited to the embodiments described herein, but is limited only by the claims that follow, the scope of which shall include all equivalents of the subject matter of the claims. Unless expressly stated otherwise, the steps in a method claim may be performed in any order. The mention of identifiers such as (a), (b), (c) or (1), (2), (3) before the steps in a method claim is not intended to, and does not, specify a particular order for the steps, but is used to simplify subsequent reference to such steps.

Claims

1. A system characterized by comprising: a container that defines a chamber and that is configured to maintain the chamber at a controlled pressure in a subsea environment; an electrical connector defined in the container that is configured to be electrically coupled to a subsea device; and a fiber optic sensing element positioned in the chamber and coupled to the electrical connector such that the fiber optic sensing element is configured to detect a voltage or current from the subsea device through the electrical connector.

2. System according to claim 1, characterized in that the fiber optic detection element includes a fiber Bragg grating (FBG) and the system further comprises a piezoelectric device coupled between the electrical connector and the FBG of the fiber optic detection element, wherein the piezoelectric device is configured to induce a mechanical stress in the FBG in response to the voltage or current of the subsea device.

3. System according to claim 2, characterized in that the FBG comprises a first FBG, the electrical connector comprises a first electrical connector, and the piezoelectric device comprises a first piezoelectric device; wherein the fiber optic sensing element includes a second FBG; wherein the system further comprises: Petition 870260053206, dated 02 / 06 / 2026, page 43 / 60 2 / 7 a second electrical connector defined in the container that is configured to be coupled to the subsea device or to another subsea device; and a second piezoelectric device that is coupled to the second electrical connector and to the second FBG such that the second piezoelectric device is configured to induce a mechanical stress in the second FBG in response to a second voltage or a second current from the subsea device or to another subsea device.

4. A system according to claim 2, characterized in that the controlled pressure is lower than the pressure of the underwater environment, the controlled pressure of the chamber is about 1 atmosphere (atm), and the system further comprises a controller that is communicatively coupled to the fiber optic detection element; wherein the controller is configured to: emit an interrogation signal to the fiber optic detection element; receive a response reflection from the FBG through the fiber optic detection element; and determine a voltage or current value based on the response reflection; wherein the controller is at least partially positioned outside the underwater environment and the controller is coupled to the fiber optic detection element via a fiber optic cable.

5. System according to claim 1, characterized by further comprising: an offshore wind turbine that is configured to generate electrical energy; Petition 870260053206, dated 02 / 06 / 2026, page 44 / 60 3 / 7 wherein the subsea device comprises a subsea electrical transformer; wherein the subsea electrical transformer is electrically coupled to the offshore wind turbine; wherein the subsea electrical transformer includes transformer oil; wherein the system further comprises: a second container that is thermally coupled to the transformer oil; and a second fiber optic sensing element positioned in the second container that is configured to detect a temperature of the transformer oil.

6. System according to claim 5, characterized in that the electrical connector is incorporated into a bulkhead connector that is configured to connect the container to an external surface of the subsea electrical transformer.

7. System according to claim 5, characterized in that the electrical connector is a wet coupling connector that is configured to be disconnected when submerged to facilitate the recovery of the container to the sea surface.

8. A method characterized by comprising: (a) lowering a container below the sea surface and into a submarine environment, where the container defines a chamber that is maintained at a controlled pressure; (b) connecting an electrical connector defined in the container to a submarine device; and Petition 870260053206, dated 02 / 06 / 2026, p. 45 / 60 4 / 7 (c) detecting a voltage or current from the submarine device with a fiber optic detection element that is positioned in the chamber.

9. Method according to claim 8, characterized in that (b) is performed before (a).

10. Method according to claim 8, characterized in that the subsea device comprises a subsea electrical transformer and by (c) comprising: (c1) actuating a piezoelectric device positioned in the vessel by use of the voltage or current from the subsea device; and (c2) inducing a mechanical voltage in a fiber Bragg grating (FBG) that is defined in the fiber optic sensing element with the piezoelectric device that is characteristic of the voltage or current; wherein the method further comprises: (d) emitting an interrogation signal to the fiber optic sensing element; (e) receiving a response reflection from the FBG through the fiber optic sensing element; (f) determining a voltage or current value based, at least in part, on the response reflection; (g) generating the interrogation signal by use of a controller that is at least partially positioned above the sea surface;(h) conduct the interrogation signal from the controller to the container via a fiber optic cable; (i) generate electrical power with an offshore wind turbine; Petition 870260053206, dated 02 / 06 / 2026, page 46 / 60 5 / 7 (j) conduct electrical power to the subsea electrical transformer, where the voltage or current is at least partially indicative of electrical power; and (k) detect the temperature of a transformer oil in the subsea electrical transformer by using a second fiber optic sensing element that is positioned in a second container, the second container being thermally coupled to the transformer oil.

11. A system characterized by comprising: a container that defines a chamber and that is configured to maintain the chamber at a controlled pressure in a subsea environment; one or more connectors defined in the container that are configured to be coupled to a subsea device; and one or more fiber optic sensing elements positioned in the chamber and coupled to the one or more connectors such that the one or more fiber optic sensing elements are configured to detect a plurality of electrical parameters of the subsea device through the one or more connectors.

12. System, according to claim 11, characterized in that one or more fiber optic detection elements include a plurality of fiber Bragg gratings (FBGs) that are coupled to one or more connectors and in that each of the plurality of FBGs is configured to detect a corresponding electrical parameter from the plurality of electrical parameters across the one or more connectors; wherein the system further comprises a plurality of piezoelectric devices that are positioned in the chamber and coupled to the plurality of FBGs such that each of the plurality of piezoelectric devices is configured to induce a mechanical stress in a corresponding FBG from the plurality of FBGs that is indicative of the corresponding electrical parameter for the corresponding FBG.

13. System according to claim 12, characterized by further comprising: a controller that is communicatively coupled to one or more fiber optic detection elements; wherein the controller is configured to: emit interrogation signals to the one or more fiber optic detection elements; receive response reflections from the plurality of FBGs through the one or more fiber optic detection elements; and determine values ​​of the plurality of electrical parameters based, at least in part, on the response reflections; wherein the one or more fiber optic detection elements comprise a single fiber optic detection element and the plurality of FBGs is positioned along the single fiber optic detection element within the chamber;The controller is configured to emit a first interrogation signal with a first wavelength to a first FBG among a plurality of FBGs through the single optical fiber detection element and is configured to emit a second interrogation signal with a second wavelength to a second FBG among a plurality of FBGs through the single optical fiber detection element. Petition 870260053206, dated 02 / 06 / 2026, p. 48 / 60 7 / 7; 14. System according to claim 12, characterized in that the plurality of electrical parameters comprises one or more voltages or currents of the subsea device.

15. System according to claim 12, characterized by further comprising: an offshore wind turbine that is configured to generate electrical energy; wherein the subsea device comprises a subsea electrical transformer that is electrically coupled to the offshore wind turbine; wherein the subsea electrical transformer includes transformer oil; wherein the system further comprises: a second container that is thermally coupled to the transformer oil; and a second fiber optic sensing element positioned in the second container that is configured to detect a temperature of the transformer oil.

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