Monitoring System

Abstract

An electric monitoring optical fiber package for an electrical monitoring sensing system is described, the system is used for monitoring and adjusting the electric or magnetic properties of an electric system or cable. The optical fiber package comprises at least one optical fiber, a portion of the optical fiber being coated with a coating material selected from the range of; electrostrictive material, magnetostrictive material, polarisation sensitive material, piezo-electric material; wherein the coating material is a polymeric material. The coated portion of the optical fiber is arranged to provide at least one sensing portion; the sensing portion comprising a sensing portion diameter. The invention aims to provide a low-cost, simpler electrical monitoring sensing system capable of sensing disturbances and anomalies in an adjacent electric system or cable.

Claims

1. An electric monitoring optical fiber package comprising at least one optical fiber having a fiber diameter, a portion of the optical fiber being coated with a coating material selected from the range of; electrostrictive material, magnetostrictive material, polarisation sensitive material, piezo-electric material; wherein the coating material is a polymeric material and wherein the coated portion is arranged to provide at least one sensing portion; the sensing portion comprising a sensing portion diameter.

2. An optical fiber package according to claim 1, wherein the polymeric material comprises resin and wherein the resin is arranged to be modified such that the polymeric material exhibits functional properties, the functional properties selected from the range of electrostrictive, magnetostrictive, polarisation sensitive, piezoelectric properties.

3. An optical fiber package according to claim 2, wherein the polymeric material resin is arranged to be modified with predetermined, selected monomers or free radicals introduced in a fiber draw polymerisation process.

4. An optical fiber package according to claim 1, wherein the sensing portion is distributed along the length of the optical fiber.

5. An optical fiber package according to claim 1, wherein at least one of the optical fibers comprises at least one optical grating.

6. An optical fiber package according to claim 1, wherein the fiber diameter is in the range from 1 m to 150 m.

7. An optical fiber package according to claim 1, wherein the sensing portion diameter is in the range from 10 m to 1000 m.

8. An optical fiber package according to claim 1, wherein the coating material comprises a polymer layer loaded with particles selected from a range of; electrostrictive particles, magnetostrictive particles, polarisation sensitive particles, piezo-electric particles.

9. An optical fiber package according to claim 1, wherein the electrostrictive material comprises a polymer layer comprising polyvinylidene fluoride, or polyvinylidene difluoride or trifluoroethylene.

10. An optical fiber package according to claim 1, wherein magnetostrictive material comprises a polymer layer that is polyurethane-based.

11. An electrical monitoring sensing system comprising; at least one optical fiber package according to claim 1, wherein the optical fiber package is arranged to detect at least one predetermined parameter linked to a change in the coating material; at least one input portion arranged to provide an optical signal and accept an optical signal; at least one detector portion arranged to accept an output optical signal.

12. A sensing system according to claim 11, wherein the parameters are used to infer properties of an electric system or cable adjacent to or near to the optical fiber package, said properties selected from a range of; voltage, current, voltage phase, current phase.

13. A sensing system according to claim 11, wherein the detector portion comprises at least one functional element selected from the range of; a processing element, a decision making element, a control element, an actuation element.

14. A sensing system according to claim 11, wherein the detected parameters are used to control the electricity available to an electric system or cable.

15. A sensing system according to claim 11, wherein the detected parameters are at least one selected from a range of; vibration, acoustic energy, strain, temperature.

16. A sensing system according to claim 11, wherein detection and sensing is arranged with the distributed sensing techniques of distributed acoustic sensing (DAS) or distributed vibration sensing (DVS) and with fiber Bragg gratings techniques arranged to detect the signal from the fiber.

17. A sensing system according to claim 16, wherein the distributed sensing technique comprises one selected from the range of; Rayleigh scattering, Brillouin scattering, Raman scattering, interferometric techniques, Bragg grating, attenuation or intensity variation.

18. A sensing system according to claim 11, wherein a distributed phase of the electric or magnetic field is detected using signal processing.

19. A sensing system according to claim 18, wherein the system is arranged to measure phasor state.

20. A sensing system according to claim 19, wherein the system is arranged to measure phasor state in a power grid monitoring system and arranged to allow measurement of frequency and voltage phase angle at either high-voltage transmission systems.

21. A sensing system according to claim 11, wherein the system is arranged to sense for synchrophasor data for grid reliability or usage applications and arranged to allow real-time operations and off-line planning applications.

22. A sensing system according to claim 11, wherein artificial intelligence (AI) techniques are used to identify information for applications to enhance grid reliability or usage.

23. A sensing system according to claim 11, wherein the system is arranged to measure phasor state and applications any one of the range of; a. real-time operations applications; b. wide-area situational awareness; c. frequency stability monitoring and trending; d. power oscillation monitoring; e. voltage monitoring and trending; f. alarming and setting system operating limits, event detection and avoidance; g. resource integration; h. state estimation; i. dynamic line ratings and congestion management; j. outage restoration; k. operations planning; l. planning and off-line applications; m. baselining power system performance; n. event analysis; o. static system model calibration and validation; p. dynamic system model calibration and validation; q. power plant model validation; r. load characterization; s. special protection schemes and islanding; t. primary frequency (governing) response.

24. A method of monitoring an electrical system or cable, wherein the method comprises the use of at least one sensing system according to claim 11.

Description

DETAILED DESCRIPTION

[0073] Specific embodiments will now be described by of example only, and with reference to the accompanying drawings, in which:

[0074] FIG. 1 shows a sectional diagram of an optical fiber package according to a first aspect of the present invention;

[0075] FIG. 2 shows a sectional diagram of an electrical cable with an optical fiber package attached according to an aspect of the present invention;

[0076] FIG. 3 shows a cross sectional view of an electrical cable 16 that can have an optical fiber package 10 shown in FIG. 1 on the cable 16 and/or embedded in the cable 16;

[0077] FIG. 4 shows a block diagram of a sensing system including an optical fiber package according to the known prior art;

[0078] FIG. 5 shows a block diagram of an electrical monitoring sensing system according to a second aspect of the present invention; and

[0079] FIG. 6 shows an arrangement of an electrical monitoring sensing system according to a second aspect of the present invention comprising an optical fiber package adjacent an electric cable, an input portion, and a communication to an output portion (output portion not shown).

[0080] The optical fiber package according to a first aspect is shown in FIG. 1. The embodiment shown comprises an optical fiber package 10 having an optical fiber package sensing portion 12 and an optical fiber package coating material 14. The optical fiber package sensing portion 12 is preferably comprised of at least one functional optical fiber core. The optical fiber package coating material 14 comprises an electrostrictive or magnetostrictive material. In use, the length of the optical fiber package 10 coated with coating material 14 comprises at least part of a sensing element for an electrical monitoring sensing system 19 (shown in FIG. 5).

[0081] The electrical monitoring sensing system 19 would be used to monitor the electric and magnetic properties of an adjacent electric system or cable. Referring to FIG. 2, an embodiment is shown with the optical fiber package 10 adjacent or near to an electric cable 16, such that the optical fiber package 10 is wound around the electric cable 16. In use, changes to the electric or magnetic properties of the electric cable 16 would cause alterations to the coating material 14 parameters comprised within the optical fiber package 10. Alterations to the coating material 14 parameters would include alterations to the dimensions of the coating material 14. These alterations would in-turn cause changes to the vibration and strain properties of the optical fiber sensing portion 12. In an alternative embodiment (not shown), the optical fiber package 10 can also be arranged parallel to the adjacent electric cable 16. In a further alternative embodiment (not shown), the optical fiber package 10 can be arranged in a pattern, such as a sinusoidal wave pattern about the adjacent electric cable 16.

[0082] It would be apparent that other arrangements of the optical fiber package 10 and the adjacent electric cable 16 would be possible. The embodiment shown in FIG. 3 provides an optical fiber package 10 situated at the periphery of the electric cable 16. Also apparent from FIG. 5 is a further embodiment of the present invention wherein an optical fiber package 10 is contained within the electric cable 16. In use either of these embodiments can be used separately or in combination to provide accurate detection of anomalies and disturbances in the electric or magnetic properties of the electric cable 16. In an alternative embodiment (not shown) the coating material 14 can be used to coat the length of the optical fiber package 10. In a preferred embodiment, the coating material 14 is used to coat discreet sections of the optical fiber package 10.

[0083] Applications of optical fiber packages within electrical monitoring sensing systems are known in the art (U.S. Pat. Nos. 5,255,428A, 6,140,810A, GB2328278A) and may take the form depicted in FIG. 4. Typical structures of such sensing systems comprise optical fibers installed at an electric system or cable 18, arranged to be interrogated by an input portion such as an optical fiber interrogator 20. Data provided through interrogation would be transferred to a detector portion comprising for example a processor and decision maker 22, which would in turn provide instructions to a control system or actuation element 24 used to adjust the properties of the electric system or cable.

[0084] FIG. 5 shows the sequence of events of an electrical monitoring sensing system 19 according to a second aspect of the present invention, which would incorporate the optical fiber package 10 according to the first aspect of the present invention. In use, disturbances or anomalies detected in the adjacent electric system or cable 16 are transferred to the electrostrictive or magnetostrictive coating material 14 by way of changes to the electrical or magnetic properties of the adjacent electric system or cable 26, 28. These changes are subsequently transferred to the optical fiber package sensing portion 12 in the form of strain or vibration changes 30. The vibration changes are then detected via an input portion arranged to provide an interrogatory optical signal and subsequently receive a backscatter signal corresponding to the vibratory parameters of the sensing portion 12, 32. The backscatter signal is provided by way of an optical grating within the sensing portion 12. The measurements received are combined with spatiotemporal parameters and then time-/geo-synchronized data is relayed 34 to the detector portion comprising a processing element 36 and decision making element 38, arranged to provide a decision on how to alter the electricity provided to the adjacent electric system or cable 16. The control element 40 is then responsible for controlling the actuation element 42 arranged to affect the electricity provided to the electric system or cable 16. In use, detection of alterations in vibration or strain parameters in the sensing portion 12 are coupled with geospatial information in order to assist in locating the source of the effects. This geospatial information can, in a preferred embodiment, come from a GPS receiver. The data processing carried out in the processing element of the detector portion can include time synchronisation.

[0085] Represented in FIG. 6 is an embodiment of the presently claimed invention shown using a diagram of the sensing process, wherein the input portion 46 may comprise an optical fiber sensor interrogator (OFSI) unit. The optical fiber package 10 provides information about the electrical disturbances and anomalies present in the adjacent electric cable 16 to the input portion 46. The displayed embodiment provides the sensing portion 12 at discreet regions 44 within the optical fiber package, shown to be distinct from regions not comprising a sensing portion 50. Preferably, the discreet regions 44 comprising sensing portions 12 further comprise at least one optical grating (not shown) for providing backscatter of optical signal to the input portion 46. In use, the input portion 46 provides one or more pulses of light to the optical fiber package 10. The resulting backscatter is detected and the deviation from the norm is measured. Disturbances or anomalies in the electric or magnetic properties of an adjacent electrical system or cable 16 cause alterations to parameters of the coating material 14 coating at least a portion of the optical fiber package 10. In a preferred embodiment the parameters affected include the dimensional parameters. As the dimensions of the coating material 14 change, the vibrational or strain parameters of the optical fiber sensing portion 12 will be altered and used to infer changes in the electric or magnetic properties of the adjacent electric system or cable. The backscatter received by the input portion will be considered against the normal backscatter expected using a processing element of a detector portion. Deviations from the expected backscatter will result in a change placed in effect by the actuation element, by way of a decision making element and a control element. In a preferred embodiment, this change comprises an alteration to the electricity provided to the adjacent electric system or cable.

[0086] It will be appreciated that the above described embodiments are given by way of example only and that various modifications thereto may be made without departing from the scope of the invention as defined in the appended claims.

[0087] For example, it will be apparent to the skilled reader that there are a number of possible combinations of the disclosed elements optionally comprised within the detector unit.

[0088] It will also be apparent to the skilled reader that synchrophasor data can be used in a series of applications to enhance grid reliability for both i) real-time operations and ii) off-line planning applications. Some of these applications are classified and listed below: [0089] i) Real-time operations applications [0090] i. Wide-area situational awareness [0091] ii. Frequency stability monitoring and trending [0092] iii. Power oscillation monitoring [0093] iv. Voltage monitoring and trending [0094] v. Alarming and setting system operating limits, event detection and avoidance [0095] vi. Resource integration [0096] vii. State estimation [0097] viii. Dynamic line ratings and congestion management [0098] ix. Outage restoration [0099] ii) Operations planning [0100] i. Planning and off-line applications [0101] ii. Baselining power system performance [0102] iii. Event analysis [0103] iv. Static system model calibration and validation [0104] v. Dynamic system model calibration and validation [0105] vi. Power plant model validation [0106] vii. Load characterization [0107] viii. Special protection schemes and islanding [0108] ix. Primary frequency (governing) response