Device and method for measuring the degradation of a power supply line

Abstract

The invention relates to a device for the non-destructive measurement of a power supply line, including a shaft; a first transmitting coil and a second transmitting coil permanently formed partially around the shaft, the first and second transmitting coils defining a central plane between the first and second transmitting coils, and having a transmitting portion extending around the shaft close to the central plane on either side of the central plane, and a return transmitting portion extending around the shaft farther than the corresponding emitting portion from the central plane; and a receiving coil permanently formed partially around the shaft, the receiving coil having a receiving portion extending around the shaft located between the transmitting portions of the first and second transmitting coils, and a return receiving portion extending around the shaft offset from a position of symmetry of the transmitting portion with respect to the central plane.

Description

DEVICE AND METHOD FOR MEASURING DEGRADATION OF AN ELECTRICAL SUPPLY LINE TECHNICAL FIELD

[0001] The application generally relates to electrical transmission and distribution lines (eg, power supply lines) and, more particularly, to a device and method for the non-destructive measurement of the degradation of the conductive and / or ferromagnetic materials constituting them. CONTEXT

[0002] It is sometimes necessary to inspect or monitor the power lines of a power grid. One type of non-destructive inspection involves eddy currents. In this type of inspection, a transmitter coil wound around the power line to be inspected carries an electric current, producing a magnetic field whose flux lines are approximately parallel to the power line. By using a receiver coil also wound around the power line, an induced electrical signal can be detected. By comparing the induced electrical signal to reference data, it is possible to determine whether the power line has any defects that would be indicative of degradation in its conductive and / or ferromagnetic materials.However, since a power line is considered infinitely long, wrapping these transmitter and receiver coils around the power line is a considerable challenge, as it often requires opening and closing the transmitter and receiver coils around the power line for inspection of the power line. Although this type of inspection is possible, it is not practical because a technician must wrap the coils on site and this cannot be done under power without putting the technician at risk. SUMMARY

[0003] It has been noted that existing inspection devices are more often than not subject to difficult and variable operating conditions and that consequently the opening and closing mechanisms of these coils may require frequent calibration and repair. For example, given the frequent opening and closing of these transmitting and receiving coils, the conductors of these coils may gradually shift from each other, thus causing unwanted shifts that can affect the measurements of induced electrical signals. In other cases, the closing of the gates is not repeatable between calibration and measurement, which greatly distorts the measurement. Therefore, a device for non-destructive inspection of a power line that would be free from such opening and closing mechanisms is highly desirable.

[0004] The present disclosure presents an inspection device for non-destructive measurement of a power supply line. The device comprises a frame extending along and around an axis. In one embodiment, the axis constitutes a virtual element representing a power supply line when the device is in the measurement position. The frame has a first end and a second end opposite the first end. The first and second ends each have a respective opening, and a lateral opening extending between the openings of the first and second ends. The openings are permanent in that the openings remain open before, during and after measurements. In doing so, the frame has an open-shaped cross-section through which the power supply line can be inserted in the measurement position.The device comprises a first transmitter coil and a second transmitter coil, both mounted to the frame and formed partially about the axis. Being only partially formed about the axis at all times, the first and second transmitter coils have said lateral opening permanently, which avoids any opening and closing of the transmitter coils, and thus allows any mechanism for opening and closing these coils to be omitted. More specifically, the first and second transmitter coils define a central plane perpendicularly intersecting the axis between the first and second transmitter coils. Each of the first and second transmitter coils has a transmitter portion extending about the axis proximate the central plane on either side thereof, and a return transmitter portion extending about the axis further than the corresponding transmitter portion from the central plane.The device also includes a receiving coil mounted to the frame and formed partially around the axis. Being only partially formed around the axis, the receiving coil has the lateral opening permanently, thus preventing any opening or closing of the receiving coil. The receiving coil has a receiving portion extending around the axis located between the transmitting portions of the first and second transmitting coils, and a return receiving portion extending around the axis spaced apart from a position of symmetry of the receiving portion with respect to the central plane. For example, the return receiving portion may be located between the transmitting and return transmitting portions of the first or second transmitting coil. Thus, in the measurement position, the power supply line is positioned along the axis inside. of the chassis through the transverse opening and through the openings in the first and second ends. The measurement itself involves the flow of an electric current through the first and second transmitting coils. This electric current thus produces a magnetic field inside the power supply line. The measurement process also involves the measurement of an electrical signal induced in the receiving coil in response to the magnetic field produced along the power supply line. Therefore, the variation of the induced electrical signal produced by the condition of the power supply line can be indicative of degradation, if any.

[0005] In a first aspect of the present disclosure, there is disclosed a device for non-destructive measurement of an electrical power line, said device comprising: a frame extending along and about an axis, said frame having a first end and a second end opposite the first end, said first and second ends each having a respective opening, and a side opening extending between the openings of said first and second ends, said frame having an open-shaped cross-section, said side opening being permanent;a first transmitter coil and a second transmitter coil mounted to the chassis and formed partially about said axis, said first and second transmitter coils defining a central plane perpendicularly intersecting said axis between said first and second transmitter coils, each of the first and second transmitter coils having a transmitter portion extending about said axis proximate said central plane on either side of said central plane, and a return transmitter portion extending about said axis further than said corresponding transmitter portion from said central plane;and a receiver coil mounted to the frame and formed partially about said axis, said receiver coil having a receiver portion extending about said axis located between the transmitter portions of said first and second transmitter coils, a position of said transmitter portion of said receiver coil defining a position of symmetry with respect to said central plane, and a return receiver portion extending about said axis spaced from said position of symmetry;wherein when said power supply line is positioned along said axis within said chassis through said transverse opening and through said openings in said first and second ends, said measuring comprises flowing an electric current through the first and second transmitter coils, thereby producing a magnetic field within said power supply line, and measuring an electrical signal induced in the receiver coil in response to said magnetic field, said induced electrical signal being indicative of degradation of said power supply line, if any.;

[0006] According to the first aspect of the present disclosure, said receiving portion is positioned on said central plane, and said return receiving portion is spaced from said central plane.

[0007] According to the first aspect of the present disclosure, said open-shaped cross-section has a shape selected from the following group of shapes: a U-shape and a Q-shape.

[0008] According to the first aspect of the present disclosure, said first transmitter coil, second transmitter coil and receiver coil are integral parts of a flexible printed circuit molded to a surface of said chassis around said axis.

[0009] According to the first aspect of the present disclosure, said electric current is a single-frequency alternating electric current.

[0010] According to the first aspect of the present disclosure, the positions of the transmitting portions of said first and second transmitting coils are adjusted to modify said induced electrical signal flowing in said receiving coil.

[0011] According to the first aspect of the present disclosure, the device further comprises an electric current source electrically connected to said first and second transmitter coils.

[0012] According to the first aspect of the present disclosure, the device further comprises a voltmeter electrically connected to said receiving coil.

[0013] According to the first aspect of the present disclosure, the device further comprising a computer in communication with said voltmeter, said computer comprising a processor, and a non-volatile computer memory on which are recorded instructions executable by said processor to carry out a step of generating a state indicative of said degradation of said electrical supply line, said state being based on said induced electrical signal.

[0014] According to the first aspect of the present disclosure, the step of generating said state comprises a step of comparing said induced electrical signal with reference data associating a plurality of reference induced electrical signals with a plurality of corresponding states.

[0015] According to the first aspect of the present disclosure, said measurement further comprises a step of comparing the induced electrical signal and said electrical current and a step of determining a change in mutual impedance based on said comparison.

[0016] According to the first aspect of the present disclosure, at least one of said first transmitter coil, second transmitter coil and receiver coil is partially wound around said axis.

[0017] According to the first aspect of the present disclosure, the transmitting portion of either of the first and second transmitting coils comprises a plurality of transmitting portions spaced from each other along said axis.

[0018] According to the first aspect of the present disclosure, said receiving portion of said receiving coil comprises a plurality of receiving portions separated from each other along said axis.

[0019] According to the first aspect of the present disclosure, said receiver coil comprises a plurality of receiver portions parallel to said central plane, said receiver portions parallel to said central plane including the receiver portion and the return receiver portion, and a plurality of receiver portions being parallel to the axis connecting the receiver portion to said return receiver portion.

[0020] According to the first aspect of the present disclosure, the return receiving portion is located between the transmitting portion and the return transmitting portion of either of said first and second transmitting coils.

[0021] In a second aspect of the present disclosure, there is disclosed a method for non-destructively measuring degradation of a power supply line, said method comprising: using an electric current source, flowing an electric current through a first transmitter coil and a second transmitter coil partially wound around said power supply line, said first and second transmitter coils having an open-shaped cross-section and defining a central plane perpendicularly intersecting said power supply line between said first and second transmitter coils, each of the first and second transmitter coils having a transmitter portion extending around said power supply line proximate to said central plane on either side of said central plane,and a return transmitting portion extending around said power supply line further than said corresponding transmitting portion at, from said central plane; using a voltmeter, detecting an induced electrical signal in a receiver coil wound partially around said power supply line, said receiver coil having an open-shaped cross-section and having a receiver portion extending around said power supply line located between the transmitter portions of said first and second transmitter coils, a position of said receiver portion of said receiver coil defining a position of symmetry with respect to said central plane, and a return receiver portion extending around said axis spaced from said position of symmetry; and using a computer in communication with said voltmeter, determining a state of said degradation of said power supply line based on the induced electrical signal detected by said voltmeter.

[0022] According to the second aspect of the present disclosure, said open shape selected from the following group of shapes: a U shape and a Q shape.

[0023] According to the second aspect of the present disclosure, said receiving portion is positioned on said central plane, and said return receiving portion is spaced from said central plane.

[0024] According to the second aspect of the present disclosure, the device further comprising a step of adjusting positions of the transmitting portions of said first and second transmitting coils to modify said induced electrical signal circulating in said receiving coil.

[0025] According to the second aspect of the present disclosure, the step of determining said state further comprises a step of comparing said induced electrical signal with reference data associating a plurality of reference induced electrical signals with a plurality of corresponding states.

[0026] In a third aspect of the present disclosure, there is disclosed a device for non-destructive measurement of a power supply line, said device comprising: an axis; a first transmitting coil and a second transmitting coil permanently formed partially about said axis, said first and second transmitting coils defining a central plane between said first and second transmitting coils, and having a transmitting portion extending about said axis proximate said central plane on either side of said central plane, and a return transmitting portion extending about said axis further than said corresponding transmitting portion from said central plane; and a receiving coil permanently formed partially about said axis, said receiving coil having a receiving portion extending about said axis located between the transmitting portions of said first and second transmitting coils, and a return receiving portion extending around said axis, spaced apart from a position of symmetry of said transmitting portion relative to said central plane.

[0027] All technical implementation details and advantages described with respect to a particular aspect of this disclosure are of course applicable mutatis mutandis to all other aspects of this disclosure.

[0028] Many other features and combinations thereof relating to the present improvements will become apparent to those skilled in the art after reading this disclosure. DESCRIPTION OF DRAWINGS

[0029] Reference is now made to the attached figures in which:

[0030] Fig. 1 is an oblique view of a first example of a device for nondestructive measurement of an electrical power line, having a Q-shaped cross-section, according to one or more embodiments of the present disclosure;

[0031] Fig. 2 is a top view of an exemplary coil arrangement positioned relative to an axis coincident with a power supply line during measurement, prior to partial winding around the axis, the coil arrangement including a first transmitter coil, a second transmitter coil, and a receiver coil, according to one or more embodiments of the present disclosure;

[0032] Fig. 2A is a sectional view of the coil arrangement of Fig. 2, taken along section 2A-2A of Fig. 2, according to one or more embodiments of the present disclosure;

[0033] Fig. 2B is a sectional view of the coil arrangement of Fig. 2A, after partial winding around the axis, according to one or more embodiments of the present disclosure;

[0034] Fig. 3 is an oblique view of an exemplary coil arrangement, having a U-shaped cross-section, according to one or more embodiments of the present disclosure;

[0035] Fig. 4 is a schematic and partial view of the magnetic field components produced by the flow of currents within the transmitter coils of the coil arrangement of Fig. 3, according to one or more embodiments of the present disclosure;

[0036] Fig. 5 is a cross-sectional view of an exemplary aluminum conductor steel reinforced (ASCR) power line, according to one or more embodiments of the present disclosure;

[0037] Fig. 6 is an oblique view of a second example of a device for non-destructive measurement of an ASCR type power supply line of Fig. 5, according to one or more embodiments of the present disclosure;

[0038] Figs. 7A and 7B are graphs showing measurements of induced electrical signals measured using the device of Fig. 6, and indicating the loss of zinc around the power supply line, for two ASCR type power supply line samples, showing reference charts, according to one or more embodiments of the present disclosure;

[0039] Fig. 8 is a side view of a third example device for non-destructive measurement of an electrical power line, according to one or more embodiments of the present disclosure;

[0040] Fig. 9A is a graph showing measurements of induced electrical signals measured using the device of Fig. 8 for a sample ASCR type power supply line, showing reference charts, according to one or more embodiments of the present disclosure;

[0041] Fig. 9B is a graph showing a zinc thickness and aluminum composition profile as a function of longitudinal position for the sample measured in Fig. 9A, according to one or more embodiments of the present disclosure;

[0042] Fig. 10 is a schematic view of an exemplary coil arrangement, showing different distances separating the coil portions of the arrangement, according to one or more embodiments of the present disclosure;

[0043] Fig. 11 A is a top view of an example coil arrangement where the distance between the transmitting portions of the transmitting coils and the receiving portion of the receiving coil is given by the variable d_r_em, before partial winding around an axis, mounting each of the transmitter coils having four turns, according to one or more embodiments of the present disclosure;

[0044] Fig. 11 B is a top view of a fourth example of a device for non-destructive measurement of an electrical power line, incorporating the coil arrangement of Fig. 11 A, after partial winding around the axis, according to one or more embodiments of the present disclosure;

[0045] Fig. 12A is a graph showing the voltage measured on the return receiving portion as a function of the spacing between the return receiving portion and the transmitting portion of one of the transmitting coils, according to one or more embodiments of the present disclosure;

[0046] Fig. 12B is a graph showing measurements of induced electrical signals measured using the device of Fig. 11B, for different spacings between the receiving portion of the receiving coil and the transmitting portions of the transmitting coils, according to one or more embodiments of the present disclosure;

[0047] Fig. 13 is an image showing different shapes of frames capable of receiving an arrangement of coils partially wound around a corresponding axis, according to one or more embodiments of the present disclosure;

[0048] Fig. 14 is a schematic view of an exemplary computing device of the computer of Fig. 1, according to one or more embodiments of the present disclosure; and

[0049] Fig. 15 is a flowchart of an exemplary method for non-destructively measuring a power line, according to one or more embodiments of the present disclosure. DETAILED DESCRIPTION

[0050] Fig. 1 shows an example of a device 100 for non-destructive measurement of a power supply line 10. As illustrated, the device 100 has an axis 102 along which the power supply line 10 is inserted into the measurement position. The device 100 comprises a frame 104 which extends along and around the axis 102. In particular, the frame 104 has a first end 104a and a second end 104b opposite the first end 104a. The first and second ends 104a and 104b each have a respective opening 106a, 106b on either side of the frame 104. The frame 104 also comprises a side opening 108 which extends between the openings 106a and 106b of the first and second ends 104a and 104b. As illustrated, the frame 104 has a permanent open-shaped cross-section 110. In the measuring position, the power supply line 10 is inserted laterally, Le., from bottom to top with reference to FIG. 1, via the openings 106a, 106b of the first and second ends 104a, 104b and the lateral opening 108 of the chassis 104. It is noted that when operating in an electrical network, the power supply line 10 is fixed at both ends, thereby preventing insertion of the power supply line 10 longitudinally via either of the openings 104a, 104b of the first and second ends 106a, 106b of the chassis 104. Thus, the lateral opening 108 is adapted to accept insertion of the power supply line 10 in a lateral direction D Lallowing the device 100 to be easily positioned around the power supply line 10 when a measurement is deemed necessary. The openings 106a, 106b and 108 are permanent in the sense that they are present at all times whether before, during and after a measurement. Thus, no mechanism for opening and closing the device is necessary.

[0051] Still referring to Fig. 1, the device 100 includes a first transmitter coil 112a and a second transmitter coil 112b (referred to as "the transmitter coils 112") which are both mounted to the frame 104 and formed partially around the axis 102. In some embodiments, the transmitter coils 112 are wound partially around the axis 102. However, in other embodiments, the transmitter coils 112 are initially manufactured in a shape formed partially around the axis 102. As illustrated, the transmitter coils 112 define a central plane 114 which perpendicularly intersects the axis 102 between the first and second transmitter coils 112a and 112b. Each of the first and second transmitter coils 112a and 112b has a transmitter portion 116a which extends around the axis 102 near the central plane 114 on either side thereof.The first and second transmitter coils 112a and 112b each also have a return transmitter portion 116b that extends about the axis 102 further than the corresponding transmitter portion 16a, 116b from the central plane 114.

[0052] As shown, the device 100 also includes a receiver coil 118 that is mounted to the frame 104 and formed partially around the axis 102. Similar to the transmitter coils 112, the receiver coil 118 may be wound partially around the axis 102. As illustrated, the receiver coil 118 has a receiver portion 118a that extends around the axis 102 and is located between the transmitter portions 116a of the transmitter coils 112. It can be seen that a position of the receiver portion 118a of the receiver coil 118 defines a symmetry position P sym relative to the central plane 114. Thus, the receiving coil 118 also includes a return receiving portion 118b which extends around the axis 102, but which is spaced from the symmetry position P sym defined by the position of the receiving portion 118a of the receiving coil 118 relative to the central plane 114.

[0053] During a measurement, the device 100 has a current source 120 configured to flow an electric current 122 through the first and second transmitter coils 112a and 112b, thereby producing a magnetic field within the power supply line 10. For example, in some embodiments, the electric current 122 is a single-frequency alternating electric current. In the illustrated embodiment, a single current source 120 is electrically connected to the transmitter coils 112. Thus, the same electric current 122 flows in each of the two transmitter coils 112. In other embodiments, two (or more) current sources independent of each other may be used to flow the electric current.In these embodiments, a first current source is configured to flow a first electrical current through the first transmitter coil, while a second current source is configured to flow a second electrical current through the second transmitter coil, or vice versa. Typically, the electrical current 122 flowing through the transmitter coils 112 produces a magnetic field that adds up to, or even maximizes, a position between the transmitter portions 116a of the transmitter coils 112. Preferably, the magnetic field maximizes at a position corresponding to the receiver portion 118a of the receiver coil 118. The device 100 also includes a voltmeter 124, or any other device capable of measuring an induced electrical signal 126 flowing in the receiver coil 118 in response to the magnetic field produced by the electrical current 122 flowing through the transmitter coils 112.It is understood that the induced electrical signal 126 measured using the voltmeter 124 may be indicative of degradation of the power supply line 10, if applicable. More particularly, the device 100 may include a computer 128 in communication with the current source 120, the voltmeter 124, or both. The computer 128 is configured to determine a degradation state 130 of the power supply line 10 based on the induced electrical current 126.

[0054] Fig. 2 shows an exemplary coil arrangement 200 including the transmitter coils 112 and the receiver coil 118. In this figure, the coil arrangement 200 is not formed, or even wound, around the axis 102. Rather, the coil arrangement 200 extends in an x,y plane, and the coils 112 and 118 are spaced apart along the longitudinal axis 102 from one another. As illustrated, the electric current 122, denoted "i" in Fig. 2, flows through the transmitter coils 122 such that the electric current i flowing along the transmitting portion 116a of the first transmitting coil 112a has the same direction as the direction of the electric current i flowing along the transmitting portion 116a of the second transmitting coil 112b. It is intentional that the receiving portion 118a and the return receiving portion 118b form an asymmetrical arrangement on either side of the central plane 114. This asymmetry prevents an undesirable situation where a magnetic field, produced by an electric current i flowing in the transmitting portions 116a, at the position of the receiving portion 118a, would be equal in magnitude to the magnetic field produced by the electric current i flowing in the transmitting portions 116a, at the position of the return receiving portion 118b. Such a magnetic field combination would in response produce mutually canceling induced electrical signals in the receiver coil 118, which would be highly undesirable.Thus, by spacing the return receiving portion 118b from the symmetry position P. sym , and preferably further from the transmitting portions 116a of the transmitting coils 112 from the central plane 114, the induced electrical signal can be reduced, or even minimized, which is preferable in order to improve the quality of the measurements and in particular the precision with which the measurements can be conducted. In other words, the optimal position of the return receiver is that which eliminates the signal seen by the return receiver.

[0055] In the illustrated embodiment, the receiving portion 118a is positioned at a position xp R relative to the central plane 114. Thus, the position of symmetry would be -x PR . As illustrated, the return receiving portion 118b of the receiving coil 118 is not positioned at the -x position PR , but rather positioned at position -x PRR which is spaced from the symmetry position Psym , ie, -x PRR ^-x PR . Preferably, the return receiving portion 118b is positioned further away than the corresponding transmitting portion 118a, ie, x PRR > x PR . As discussed below, it may also be advantageous to position the return receiving portion 118b between the transmitting portion 118a and the return transmitting portion 118b of the same transmitting coil 112. In other embodiments, particularly in preferred embodiments, the receiving portion 118 may be positioned directly on the central plane 114, coinciding with it. In these embodiments, the symmetry position P sym would correspond to x = 0, thus the return receiving portion 118b would be spaced from the central plane 114, i.e., x PRR 0.

[0056] As best shown in Fig. 2A, the plane of the coil arrangement 200 may be parallel to the axis 102 prior to partial winding. By the term "partially formed about the axis," it is meant that the plane of the coil arrangement 200 may be formed (e.g., wound, folded) about the axis 102 in such a way that the coils 112a, 112b, and 118 remain spaced along the longitudinal axis 102 relative to one another while leaving at least one lateral opening 108 thus allowing space for a power supply line to be inserted and removed along the lateral orientation O. This winding is illustrated in Fig. 2B, which shows that the coil arrangement 200 has a cross-section 110 of open shape. Examples of open shapes include, but are not limited to, a U-shape, a u-shape, a Q-shape, a C-shape, a c-shape, a V-shape, a v-shape, or any other shape having an opening inside which the power supply line can be inserted without changing the shape of the coils. It is understood that the open shape can be modular depending on the type of measurement to be carried out. The open shape is not necessarily formed of a curved and continuous line, while an open polygonal shape could also be considered.In some embodiments, the coil arrangement 200 is positioned on a flexible substrate that can be formed into the desired open shape. For example, the transmitter coils 112 and receiver coil 118 may be integral parts of a flexible printed circuit board (PBC). In other embodiments, the coil arrangement 200 may be fabricated from the outset with the open shape, thereby omitting a step of forming or winding the coil arrangement about the axis 102. If so, the resulting coil arrangement 200 would still be partially formed about the axis 102. In other embodiments, the coils may be made with wires rather than a printed circuit board. Thus, these wires could be molded to a surface of the chassis about the axis.

[0057] Fig. 3 shows another example of coil arrangement 300. As illustrated, coil arrangement 300 is partially wound around axis 102, and has an open U-shaped cross-section. In this example, each of the transmitter coils 112 has four turns. However, in other embodiments, the transmitter coils 112 may have fewer than four turns or more than four turns. For each of the transmitter coils 112, the turns define transmitter portions 116a spaced apart from each other along axis 102. Therefore, the transmitter portion 116a of the first transmitter coil 112a includes four transmitter portions 116a parallel to each other. Similarly, the transmitter portion 116a of the second transmitter coil 112b includes four transmitter portions 116a parallel to each other.More specifically, for the first and second transmitter coils 112a and 112b, the turns of each transmitter coil 112 also have transmitter portions 116c and 116d parallel to the axis 102 that connect the receiver portions 116a to the return receiver portions 116b. Each of the transmitter portions 116a of a transmitter coil 112 may be connected in series such that electric current flows along a parallel return transmitter portion 116a. to the central plane 114 and proximal thereto, then along an emitting portion 116c parallel to the axis 102, then along another emitting portion 116b parallel to the central plane and distal thereto, then along another emitting portion 116d parallel to the axis 102, and so on. The receiver coil may have several emitting portions parallel to the central plane or to the axis as well. However, in the embodiment shown in FIG. 3, the receiving coil 118 comprises a single turn, including a receiving portion 118a parallel to and proximal to the central plane 114, a receiving portion 118c parallel to the axis 102, a return receiving portion 118b parallel to and distal to the central plane 114, and then a receiving portion 118d parallel to the axis 102 to close the loop.

[0058] Although the take-up coil 118 has only one turn in this embodiment, it is understood that the take-up coil 118 could have more than one turn in other embodiments. More specifically, a take-up portion 118a of the take-up coil 118 may have take-up portions 118a separated from each other along the axis 102. Furthermore, the take-up coil 118 could have take-up portions parallel to the central plane 114, including in particular the take-up portion 118a and the return take-up portion 118b; and take-up portions being parallel to the axis 102 connecting the take-up portion 118a to said return take-up portion 118b. Other embodiments for the take-up coil 118 are also possible. For example, the receiving and transmitting portions are not necessarily parallel to the central plane 114 or parallel to the axis 102.

[0059] As discussed briefly above, and now referring to Fig. 4, it may be advantageous to position the return receiving portion 118b at an axial position centered between the transmitting portion 116a and the return transmitting portion 116a of a same transmitting coil 112. Thus, the magnetic field lines produced by the flow of electric current in the corresponding transmitting coil 112 would be parallel to the return receiving portion 118b, thereby reducing any electrical signal that might be induced at the position of the return receiving portion 118b.

[0060] Fig. 5 shows an example of a power supply line 10 of the type having an aluminum conductive portion and steel reinforcement for the mechanical support portion (also called an "ASCR type power supply line"). Fig. 6 shows an example of a device 600 designed for the non-destructive measurement of samples of an ASCR type power supply line illustrated in Fig. 5. Since the device of Fig. 6 is only a prototype for laboratory use, it has a frame 604 which does not necessarily have a side opening 108, since the samples are relatively short and can be inserted inside the coil arrangement through the opening of one end of the frame 604. In this experiment, two samples were measured: the Curlew sample 3 and the Lark sample 4, the non-destructive measurement results of which are shown in Figs. 7A and 7B, respectively. These results are superimposed on reference charts 20 having regions indicative of different states of degradation of the power supply line. Of these regions, region A is indicative of a new conductor, region B is indicative of a sound conductor, region C is indicative of possible losses of the zinc plating (10-20 pm), region D is indicative of partial losses (5-10 pm), region E is indicative of severe losses (0-5 pm) and region F is indicative of aluminum loss. Each of the crosses identifies a measurement associated with a longitudinal position of the sample relative to the coil arrangement.Such reference charts 20 may be determined by measuring a significant number of power line samples whose degradation state is known. Then, the reference charts 20 resulting from such a process may be used with the device 600 to non-destructively measure power lines that would have unknown degradation states. The information associated with these reference charts 20 may be part of reference data (e.g., which may be part of a local or external database) used to associate an induced electrical signal with a corresponding degradation state. In other embodiments, these reference charts may be calculated from finite element simulations. Charts could also be determined for other detectable plating metals with the method and device disclosed in the present disclosure.

[0061] Fig. 8 shows another prototype device 800 of the present disclosure. As illustrated, the frame 804 of this device has an open U-shaped cross-section. Figs. 9A and 9B show results obtained during measurements of the Curlew 5 sample using the device of Fig. 8. In particular, Fig. 9A shows the induced electrical signal measurements superimposed on a reference chart 20 comprising four different regions. Each of the crosses identifies a measurement associated with a longitudinal position of the sample relative to the coil arrangement. The results obtained in Fig. 9A correspond well to the known degradation profile of the Curlew 5 sample as shown in Fig. 9B.

[0062] It is important to note that the reference charts illustrated in the present application were determined using existing devices (including coil opening and closing mechanisms). Measurements taken with the device of the present disclosure may therefore not correspond to the states shown using prior art charts. In another aspect, a method is presented for modifying the configuration of the device of the present disclosure so that its own reference charts correspond to the reference charts of existing devices of the prior art. Such a modification of the configuration of a device implies in certain embodiments that the position of the emitter is adjusted so that the device can be used with the reference charts. This method of modifying the device requires some definitions and distances specific to the coil arrangement. This nomenclature is described with reference to Fig. 10, which shows that emr1 denotes the return emitter portion of the first coil, rr denotes the return receiver portion of the receiver coil, em1 denotes the emitter portion of the first coil, r denotes the receiver portion of the receiver coil, em2 denotes the emitter portion of the second coil,and emr2 denotes the return transmitting portion of the second coil. It can be deduced from this figure that the magnetic fields produced by the transmitting portions of the transmitting coils add up at the position of the receiving portion of the receiving coil. Furthermore, Fig. 10 shows that l_r denotes the width of the receiving portion, l_rr denotes the width of the return receiving portion, I_em1 and I_em2 denote the width of the emitting portions of the transmitting coils, I_emr1 and I_emr2 denote the width of the return emitting portions of the transmitting coils, R denotes the partial winding radius of the coils, d_rr_emr2 denotes the axial distance between the return emitting portion of the second transmitting coil and the return receiving portion of the receiving coil, d_rr_em2 denotes the axial distance between the emitting portion of the second transmitting coil and the return receiving portion of the receiving coil,d_rr_em1 denotes the axial distance between the transmitting portion of the first transmitting coil and the return receiving portion of the receiving coil, d_rr_emr1 denotes the axial distance between the return receiving portion and the return transmitting portion of the first transmitting coil, d_r_em1 denotes the distance between the transmitting portion of the first transmitting coil and the receiving portion of the receiving coil, d_r_em2 denotes the distance between the transmitting portion of the second transmitting coil and the receiving portion of the receiving coil, d_r_emr1 denotes the distance between the return transmitting portion of the first transmitting coil and the receiving portion of the receiving coil, d_r_emr2 denotes the distance between the return transmitting portion of the second transmitting coil and the receiving portion of the receiving coil, and L denotes the distance between the return transmitting portion of the first coil and the return transmitting portion of the second coil.,

[0063] It has been found that by changing either of the distances introduced above, the induced electrical signals measured using the corresponding device can be shifted to correspond to measurements that would have been taken with the prior art device. In other words, the positions of the transmitting portions of the transmitting coils can be adjusted to change the induced electrical signal flowing in the receiving coil. For example, a experiment was carried out in which several devices were made by modifying the distances d_r_em1 and d_r_em2 for each of the devices. More specifically, devices having the same distances and the same configuration, namely that of the coil arrangement of Fig. 10, but where the distances d_r_em1 and d_r_em2 were modified to 27 mm, 31 mm and 35 mm, were made. An example of one of these devices 1100 is shown in Fig. 11 A, which shows the coil arrangement before its partial winding around the axis, and in Fig. 11 B, which shows the coil arrangement after its partial winding around the axis. As shown, the distances d_r_em1 and d_r_em2 were fixed at 27 mm in this example. Fig.12A shows the voltage on the return receiving portion as a function of the spacing between the return receiving portion and the transmitting portion of one of the transmitting coils, according to a simulation exploring distances d_r_em1 and d_r_em2 varying between 22.5 mm and 27 mm. Fig. 12B is a graph showing measurements of induced electrical signals measured using the device 1100 of Fig. 11 B, for different spacings between the receiving portion of the receiving coil and the transmitting portions of the transmitting coils. As can be seen, by decreasing the distances d_r_em1 and d_r_em2, the measured electrical signals move increasingly to the left. Similar results could be achieved by modifying l_r, l_rr, I_em1 , 1_em2, 1_emr1 , 1_emr2, R, d_rr_emr2, d_rr_em2, d_rr_em1 , d_rr_emr1 , d_r_em1 , d_r_em2, d_r_emr1 , d_r_emr2, L, or a combination thereof. In one embodiment, the distance L is less than or equal to 158 mm.

[0064] Fig. 13 shows various examples of frames that can be used in the device described in the present disclosure. Indeed, it is shown, from left to right, a first frame having an open U-shaped cross-section with flanges, a second frame having an open U-shaped cross-section without flanges, a third frame having an open Q-shaped cross-section with flanges, and a fourth frame having an open U-shaped cross-section without flanges having a smaller diameter than the second. It is understood that the open shapes with flanges can facilitate the insertion of the power supply line inside the coil arrangement in addition to moving the returns away. That said, the coil arrangement can be molded to an interior face of the frame or even to an exterior face of the frame, depending on the embodiment.In all of these embodiments, a corresponding lateral opening allows for the sliding of a power supply line along a lateral orientation so that it corresponds to the axis 102 during a measurement.

[0065] Referring now to Fig. 14, the computer of the device of Fig. 1 may be provided as a combination of hardware and software components. The hardware components may be implemented as a computing device 1400, an example of which is described with reference to Fig. 14. The computing device 1400 may have a processor 1402, a computer-readable non-volatile memory 1404, and an input / output (I / O) interface 1406. Control instructions 1408 for accessing and processing measured data may be stored on the memory 1404 and accessible by the processor 1402.

[0066] The processor 1402 may be, for example, a general-purpose microprocessor or microcontroller, a digital signal processing (DSP) processor, an integrated circuit, a field-programmable logic gate array (FPGA) processor, a reconfigurable processor, a programmable read-only memory (PROM) processor, a programmable logic controller (PLC), or any combination thereof.

[0067] Memory 1404 may include a suitable combination of any type of computer-readable memory located either internally or externally, such as, for example, random access memory (RAM), read only memory (ROM), compact disc read only memory (CDROM), electro-optical memory, magneto-optical memory, erasable programmable read only memory (EPROM), electrically erasable programmable read only memory (EEPROM), ferroelectric random access memory (FRAM), or the like.

[0068] Each I / O interface 1406 allows the computing device 1400 to interconnect with one or more input devices, such as a mouse, a computer keyboard, a voltmeter, or with one or more output devices such as a power source, a monitor, an external network, computer memory, etc.

[0069] Each 1406 I / O interface allows the controller to communicate with other components, exchange data with other components, access and connect to network resources or servers, and run other computer applications by connecting to a network (or networks) capable of transporting data, including the Internet, Ethernet, Plain Old Telephone Service (POTS), Public Switched Telephone Network (PSTN), Integrated Services Digital Network (ISDN), Digital Subscriber Line (DSL), coaxial cable, fiber optic, satellite, mobile, wireless (e.g., Wi-Fi, WiMAX), SS7 signaling network, landline, LAN, WAN, and others, including any combination thereof.

[0070] The computing device 1400 and any software application that may be executed by the computing device 1400 are presented for exemplary purposes only. Other modes of suitable embodiments of the computing device 1400 may also be proposed, as will be apparent to the skilled reader.

[0071] Fig. 15 shows a flowchart of a method 1500 for the non-destructive measurement of degradation of a power supply line.

[0072] In step 1502, a first transmitter coil, a second transmitter coil, and a receiver coil are partially wound around the power supply line. As discussed above, the first transmitter coil, second transmitter coil, and receiver coil have an open-shaped cross-section into which the power supply line is inserted during measurement. Depending on the embodiment, the open shape of each of these coils may be selected from the following group of shapes: a U-shape, a u-shape, a Q-shape, a C-shape, a c-shape, a V-shape, a v-shape, or any other shape having an opening into which the power supply line can be inserted without changing the shape of the coils. It is preferable that the coils have the same open shape. However, in some embodiments, the coils may have different open shapes.

[0073] As discussed, the first and second transmitter coils define a central plane perpendicularly intersecting the power supply line between the first and second transmitter coils. Each of the first and second transmitter coils has a transmitter portion extending around the power supply line proximate the central plane on either side of the central plane, and a return transmitter portion extending around the power supply line further than the corresponding transmitter portion from the central plane.

[0074] In step 1504, using an electrical current source, an electrical current is caused to flow through the first and second transmitter coils while the latter are partially wound around the electrical supply line. It is understood that the electrical current source may be provided as a single electrical current source electrically connected to the first and second transmitter coils. However, in other embodiments, the electrical current source may comprise two electrical current sources connected to the first and second transmitter coils, respectively.

[0075] As mentioned above, the electric current flowing through transmitter coils is such that the current flows in the same direction along the transmitter portions of the first and second transmitter coils. In doing so, the magnetic field components produced by the flow of these electric currents through the transmitter coils add up at a location between the transmitting portions of the first and second transmitting coils.

[0076] At step 1506, using a voltmeter, an induced electrical signal is detected in the receiver coil while it is partially wound around the power supply line.

[0077] The receiver coil has a receiver portion extending around the power supply line located between the transmitter portions of the first and second transmitter coils. A position of the receiver portion of the receiver coil defines a symmetry position with respect to the central plane. The receiver coil also includes a return receiver portion extending around the axis, but spaced from the symmetry position. The receiver portion may be positioned on the central plane. In such an embodiment, the return receiver portion may be spaced from the central plane toward either of the transmitter portions of the transmitter coils. In other embodiments, the receiver portion is spaced from the central plane so long as the return receiver portion is spaced from the symmetry position of the receiver portion with respect to the central plane.In some embodiments, the magnetic field components produced by the flow of these electric currents through the transmitter coils add up, and preferably maximize, at a location corresponding to the position of the receiver portion of the receiver coil.

[0078] In step 1508, using a computer in communication with the voltmeter, a degradation state of the power supply line is determined based on the induced electrical signal detected by the voltmeter. As discussed above, the computer may include a processor, and a computer-readable non-volatile memory having stored thereon instructions executable by the processor to perform one or other of the steps of the method 1500. This step of determining the state may further include a step of comparing the induced electrical signal to reference data associating reference induced electrical signals with corresponding states. The reference data may be provided in the form of a lookup table or a mathematical function. Thus, by measuring a given electrical signal, it may be compared to the reference induced electrical signals in order to determine the corresponding state.Additionally or alternatively, the step of determining the state may further comprise a step of comparing the induced electrical signal and the electrical current, but also a step of determining a change in mutual impedance based on this latter comparison. Thus, in certain embodiments, it is not necessarily the value of the induced electrical signal that is compared to the reference data, but rather the change in mutual impedance.

[0079] The method may comprise a step of adjusting the positions of the emitting portions of the first and second emitting coils in order to modify the induced electrical signal circulating in the receiving coil. As discussed above, this adjustment step may make it possible to modify the induced electrical signals so that they correspond to what would have been measured with existing devices, in particular those having a mechanism for opening and closing the coils. In doing so, this would have the advantageous consequence of not having to produce new databases associating reference induced electrical signals with the corresponding states using the device described in the present application, but rather of reusing the established databases using existing devices, in particular those having a mechanism for opening and closing the coils.

[0080] The above description is given by way of example only and the person skilled in the art will recognize that modifications may be made to the described embodiments without departing from the scope of the disclosed invention. For example, the apparatus and method described in the present disclosure may be used to perform non-destructive measurements involving eddy currents. Still other modifications that fall within the scope of the present invention will be apparent to the person skilled in the art upon examination of the present invention, and such modifications are intended to be included in the appended claims.

Claims

CLAIMS 1. A device for non-destructive measurement of an electrical power line, said device comprising: a frame extending along and about an axis, said frame having a first end and a second end opposite the first end, said first and second ends each having a respective opening, and a side opening extending between the openings of said first and second ends, said frame having an open-shaped cross-section, said side opening being permanent;a first transmitter coil and a second transmitter coil mounted to the chassis and formed partially about said axis, said first and second transmitter coils defining a central plane perpendicularly intersecting said axis between said first and second transmitter coils, each of the first and second transmitter coils having a transmitter portion extending about said axis proximate said central plane on either side of said central plane, and a return transmitter portion extending about said axis further than said corresponding transmitter portion from said central plane;and a receiver coil mounted to the frame and formed partially about said axis, said receiver coil having a receiver portion extending about said axis located between the transmitter portions of said first and second transmitter coils, a position of said transmitter portion of said receiver coil defining a position of symmetry with respect to said central plane, and a return receiver portion extending about said axis spaced from said position of symmetry;wherein when said power supply line is positioned along said axis within said chassis through said transverse opening and through said openings in said first and second ends, said measuring comprises flowing an electric current through the first and second transmitter coils, thereby producing a magnetic field within said power supply line, and measuring an electrical signal induced in the receiver coil in response to said magnetic field, said induced electrical signal being indicative of degradation of said power supply line, if any.; 2. The device of claim 1, wherein said receiving portion is positioned on said central plane, and said return receiving portion is spaced from said central plane.

3. The device according to claim 1 or 2, wherein said open-shaped cross-section has a shape selected from the following group of shapes: a U-shape and a Q-shape.

4. The device of any one of claims 1 to 3, wherein said first transmitter coil, second transmitter coil and receiver coil are integral parts of a flexible printed circuit molded to a surface of said chassis around said axis.

5. The device according to any one of claims 1 to 4, wherein said electric current is a single-frequency alternating electric current.

6. The device according to any one of claims 1 to 5, wherein the positions of the transmitting portions of said first and second transmitting coils are adjusted to modify said induced electrical signal flowing in said receiving coil.

7. The device according to any one of claims 1 to 6, further comprising an electric current source electrically connected to said first and second transmitter coils.

8. The device according to any one of claims 1 to 7, further comprising a voltmeter electrically connected to said receiving coil.

9. The device of claim 8, further comprising a computer in communication with said voltmeter, said computer comprising a processor, and a non-volatile computer memory on which are recorded instructions executable by said processor to perform a step of generating a state indicative of said degradation of said power supply line, said state being based on said induced electrical signal.

10. The device according to claim 9, wherein the step of generating said state comprises a step of comparing said induced electrical signal with reference data associating a plurality of reference induced electrical signals with a plurality of corresponding states.

11. The device according to any one of claims 1 to 10, wherein said measurement further comprises a step of comparing the induced electrical signal with said electrical current and a step of determining a change in mutual impedance based on said comparison.

12. The device according to any one of claims 1 to 11, wherein at least one of said first transmitting coil, second transmitting coil and receiving coil is partially wound around said axis.

13. The device according to any one of claims 1 to 12, wherein the transmitting portion of either of the first and second transmitting coils comprises a plurality of transmitting portions separated from each other along said axis.

14. The device according to any one of claims 1 to 13, wherein said receiving coil comprises a plurality of receiving portions parallel to said central plane, said receiving portions parallel to said central plane including the receiving portion and the return receiving portion, and a plurality of receiving portions being parallel to the axis connecting the receiving portion to said return receiving portion.

15. A method for non-destructively measuring degradation of a power supply line, said method comprising: using an electric current source, flowing an electric current through a first transmitter coil and a second transmitter coil partially wound around said power supply line, said first and second transmitter coils having an open-shaped cross-section and defining a central plane perpendicularly intersecting said power supply line between said first and second transmitter coils, each of the first and second transmitter coils having a transmitter portion extending around said power supply line proximate to said central plane on either side of said central plane,and a return transmitting portion extending around said power supply line further than said corresponding transmitting portion from said central plane; using a voltmeter, detecting an electrical signal induced in a receiver coil wound partially around said power supply line, said receiver coil having an open-shaped cross-section and having a receiver portion extending around said power supply line located between the transmitting portions of said first and second transmitting coils, a position of said receiver portion of said receiver coil defining a position of symmetry with respect to said central plane, and a return receiving portion extending around said axis spaced from said position of symmetry; and, using a computer in communication with said voltmeter, determining a state of said degradation of said electrical power line based on the induced electrical signal detected by said voltmeter.

16. The method of claim 15, wherein said open shape is selected from the following group of shapes: a U-shape and a Q-shape.

17. The method of claim 15 or 16, wherein said receiving portion is positioned on said central plane, and said return receiving portion being spaced from said central plane.

18. The method according to any one of claims 15 to 17, further comprising a step of adjusting positions of the transmitting portions of said first and second transmitting coils to modify said induced electrical signal circulating in said receiving coil.

19. The method according to any one of claims 15 to 18, wherein the step of determining said state further comprises a step of comparing said induced electrical signal with reference data associating a plurality of reference induced electrical signals with a plurality of corresponding states.

20. The method according to any one of claims 15 to 19, wherein the step of determining said state further comprises a step of comparing the induced electrical signal with said electrical current and a step of determining a change in mutual impedance based on said comparison.