An independent detection device for monitoring the magnetic field of a reactor and a method of application thereof

Abstract

The application discloses an independent detection device for monitoring a magnetic field of a reactor and an application method thereof. The independent detection device comprises a horizontal coil and a vertical coil arranged on a base. The horizontal coil and the vertical coil are perpendicular to each other, and the centers of the horizontal coil and the vertical coil coincide. The axis of the horizontal coil is along the radial direction of the reactor, and the axis of the vertical coil is parallel to the central axis of the reactor. The method comprises the following steps: obtaining the induced voltage u z of the incoming line end of the horizontal coil, the induced voltage u Σ of the common end of the horizontal coil and the vertical coil, and the induced voltage u r of the outgoing line end of the vertical coil; calculating the modulus of the magnetic induction intensity of the target position according to the induced voltage u Σ , and calculating the magnetic induction intensity vector of the target position according to the induced voltage u z and u r ; if the modulus of the magnetic induction intensity of the target position is greater than a preset value, the reactor has a turn-to-turn short circuit fault, and the turn-to-turn short circuit position is determined according to the corresponding magnetic induction intensity vector. The application can effectively monitor the magnetic field independently of the reactor.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of magnetic field monitoring, in particular to an independent detection device for monitoring the magnetic field of a reactor and a method of application thereof. BACKGROUND

[0002] Due to severe working conditions, dry-type air-core reactors have frequent accidents. Turn-to-turn short-circuit fault is one of the important reasons for causing severe dry-type air-core reactor faults. The local high temperature generated by the turn-to-turn short-circuit current can directly burn the reactor and cause power failure accidents, which seriously affects the stable operation of the power system.

[0003] At present, the online monitoring of turn-to-turn short-circuit faults of dry-type air-core reactors mainly adopts three categories of temperature field monitoring method, active power (phase) detection method and magnetic field detection method. Among them, the magnetic field detection method is reliable and sensitive, and is especially suitable for online monitoring and early warning application of turn-to-turn short-circuit faults of reactors. The main principle is that when a turn-to-turn short-circuit fault occurs, a large short-circuit current will be generated in the short-circuit ring, causing a significant change in the local magnetic field of the reactor, which destroys the symmetry of the magnetic field distribution of the reactor. By winding detection coils on the top and bottom of the reactor body to sense the electromagnetic field signals, the running state of the reactor is judged through a pre-set threshold or statistical test method to identify the turn-to-turn short-circuit fault for early warning and alarm. The limitation of the magnetic field detection method is that the detection coil needs to be wound on the reactor body, which is equivalent to adding a peripheral structure to the reactor body, which will affect the electrical insulation and process reliability of the reactor to varying degrees, may cause safety hazards of the equipment, and the on-site construction is difficult, making it difficult to implement technical upgrading and transformation of the existing reactors. SUMMARY

[0004] The technical problem to be solved by the present application is to provide an independent detection device for monitoring the magnetic field of a reactor, which is independent of the reactor body and widely applicable to different fields and purposes related to reactor state monitoring.

[0005] To solve the above technical problems, the technical solution provided by the present application is as follows:

[0006] An independent detection device for monitoring the magnetic field of a reactor comprises a horizontal coil and a vertical coil arranged on a base, the horizontal coil and the vertical coil are perpendicular to each other in the plane, and the centers of the horizontal coil and the vertical coil coincide, the axis of the horizontal coil is along the radial direction of the reactor, and the axis of the vertical coil is parallel to the central axis of the reactor.

[0007] Further, it further comprises a support member supported on the inner wall of the horizontal coil and the vertical coil.

[0008] Further, the horizontal coil and the vertical coil are sleeved with each other, and the horizontal coil and the vertical coil are same in size and same in the number of turns.

[0009] Further, the horizontal coil and the vertical coil are same in the inner diameter of 300 mm and same in the number of turns of 20 turns, and are clockwise wound by copper wires with a diameter of 0.5 mm.

[0010] Further, the horizontal coil is sleeved outside the vertical coil, and the number of turns of the vertical coil is greater than that of the horizontal coil.

[0011] Further, the horizontal coil and the vertical coil are both counterclockwise wound by copper wires with a diameter of 0.3 mm in a single layer, the horizontal coil is 400 mm in the inner diameter of winding and 20 turns in the number of turns, and the vertical coil is 380 mm in the inner diameter of winding and 22.2 turns in the number of turns.

[0012] Further, the horizontal coil and the vertical coil are both counterclockwise wound by copper wires with a diameter of 0.5 mm in a stacked layer, the horizontal coil is 280 mm in the inner diameter of winding and 25 turns in the number of turns, and adopts 5 layers of stacking, and the vertical coil is 200 mm in the inner diameter of winding and 53.1 turns in the number of turns, and adopts 9 layers of stacking.

[0013] The application further provides an application method of the independent detection device for monitoring the magnetic field of the reactor.

[0014] S1) installing the independent detection device at a target position of the reactor, and connecting a wire inlet end of the horizontal coil, a common end of the horizontal coil and the vertical coil, and a wire outlet end of the vertical coil, respectively;

[0015] S2) obtaining an induced voltage u z of the wire inlet end of the horizontal coil, an induced voltage u Σ of the common end of the horizontal coil and the vertical coil, and an induced voltage u r of the wire outlet end of the vertical coil;

[0016] S3) calculating a modulus of the magnetic induction intensity of the target position according to the induced voltage u Σ , and calculating a magnetic induction intensity vector of the target position according to the induced voltage u z and u r ;

[0017] S4) if the modulus of the magnetic induction intensity of the target position is greater than a preset value, the reactor has a turn-to-turn short circuit fault, and a turn-to-turn short circuit position is determined according to the corresponding magnetic induction intensity vector.

[0018] Further,

[0019] When the electric reactor is a 500kVA electric reactor, the target position is 500mm away from the height direction of the bottom of the electric reactor and 1200mm away from the radial direction of the outer package surface of the electric reactor;

[0020] When the electric reactor is a 30kVA electric reactor, the target position is 150mm away from the height direction of the bottom of the electric reactor and 400mm away from the radial direction of the outer package surface of the electric reactor;

[0021] When the electric reactor is a 20000kVA electric reactor, the target position is 100mm away from the height direction of the bottom of the electric reactor and 1200mm away from the radial direction of the outer package surface of the electric reactor.

[0022] Further:

[0023] When the electric reactor is a 500kVA electric reactor, the preset value is 12V;

[0024] When the electric reactor is a 30kVA electric reactor, the preset value is 6.5V;

[0025] When the electric reactor is a 20000kVA electric reactor, the preset value is 25.5V.

[0026] Compared with the prior art, the present application has the following advantages:

[0027] The present application comprises two groups of orthogonal coils, the planes where the two groups of coils are perpendicular to each other, and the centers of the two groups of coils coincide, the axial direction of one group of coils is along the radial direction of the electric reactor, and the axial direction of the other group of coils is parallel to the central axis of the electric reactor, which reduces the mutual inductance coefficient, and respectively independently induces the spatial axial and radial magnetic field changes, so that when the electric reactor occurs turn-to-turn short circuit fault, no matter where the fault occurs in the different packages and different heights of the electric reactor, the magnetic field disturbance caused by the superposition will inevitably produce induction and voltage change through at least one of the two groups of coils, and the spatial vector of the magnetic induction intensity can be obtained according to the independent induction voltage of the two groups of coils, which fundamentally overcomes the directional selectivity defects of the spatial orientation or the magnetic induction intensity vector of the traditional single group of coils, thereby being widely applicable to different fields and purposes related to the state monitoring of electric reactors. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 It is a schematic diagram of the spatial magnetic field distribution of the electric reactor.

[0029] Figure 2 It is a schematic diagram of the spatial magnetic field distribution of the turn-to-turn short circuit ring.

[0030] Figure 3 It is a schematic diagram of the independent detection device of the present application.

[0031] Figure 4 It is a schematic diagram of the independent detection device structure of the first embodiment of the present application.

[0032] Figure 5 Application method flow chart for embodiment one of the present application.

[0033] Figure 6 Independent detection device structure schematic diagram for embodiment two of the present application.

[0034] Figure 7 Independent detection device structure schematic diagram for embodiment three of the present application.

[0035] Legend: 1 - base; 2 - horizontal coil; 3 - vertical coil; 4 - support. DETAILED DESCRIPTION

[0036] The present application is further described below in conjunction with the accompanying drawings and specific preferred embodiments, but the protection scope of the present application is not limited thereby.

[0037] As Figure 1 shown, the magnetic field distribution generated by the reactor in service in space is represented by magnetic lines, which is a set of non-overlapping closed lines in space, the tangent direction of which is the direction of the magnetic induction intensity B vector, and the line density corresponds to the modulus of the magnetic induction intensity B. Since the detection coil can only sense the magnetic flux change Φ = B · S, when the magnetic induction intensity B is parallel to the detection coil, the detection coil cannot sense the change of the magnetic induction intensity B, showing strong direction selectivity.

[0038] An equivalent form of the reactor turn-to-turn short circuit fault can be represented as a current loop of one or more turns appearing at a certain height position of the reactor, as Figure 3 shown, the magnetic field of the current loop is superimposed on the original magnetic field of the reactor, generating a disturbance signal in the detection coil. Because of the randomness and uncertainty of the turn-to-turn short circuit position, the detection coil cannot predict the angle, position and direction in advance, which becomes the biggest obstacle for magnetic field monitoring.

[0039] Considering that the reactor in service of the power grid belongs to an axisymmetric structure, its magnetic induction intensity B is composed of axial and radial components. Therefore, we use two groups of orthogonal detection coils with specific number of turns arranged concentrically and perpendicularly, as Figure 3 shown, the axial direction of one group of coils is along the radial direction of the reactor, and the axial direction of the other group of coils is parallel to the central axis of the reactor, which reduces the mutual inductance coefficient while independently sensing the axial and radial magnetic field changes in space, respectively, generating radial induction voltage u z , axial induction voltage u r and total induction voltage u Σ , the induction voltage u Σ can reflect the change of the magnetic induction intensity B at the monitoring position, and the induction voltages u z and u rThe magnetic induction intensity B of the monitoring position can be synthesized into a vector, so that when a turn-to-turn short circuit fault occurs in the reactor, regardless of the different packages and different heights of the reactor where the fault occurs, the superposition of the magnetic field disturbance caused by the fault will inevitably produce an induction and voltage change in the two groups of detection coils, which fundamentally overcomes the spatial orientation or the directional selectivity of the magnetic induction intensity B vector of the traditional single group of coils, thereby being widely applicable to different fields and uses related to the state monitoring of the reactor.

[0040] Embodiment one

[0041] Based on the foregoing concept, the embodiment proposes an independent detection device for magnetic field monitoring of a reactor, as shown in Figure 4 , which comprises a horizontal coil 2 and a vertical coil 3 arranged on a base 1, the planes where the horizontal coil 2 and the vertical coil 3 are perpendicular to each other, and the centers of the horizontal coil 2 and the vertical coil 3 coincide, the axis of the horizontal coil 2 is along the radial direction of the reactor, and the axis of the vertical coil 3 is parallel to the central axis of the reactor.

[0042] In order to increase the strength of the device, the independent detection device in the embodiment further comprises a support 4 supported on the inner walls of the horizontal coil 2 and the vertical coil 3. Specifically, the support 4 of the embodiment adopts a support framework, which, as shown in Figure 4 , is composed of three support rods intersecting at a point and perpendicular to each other, wherein one support rod in the vertical direction is supported at both ends on the inner wall of the vertical coil 3, one support rod in the horizontal direction is supported at both ends on the inner wall of the horizontal coil 2, and the other support rod in the horizontal direction is supported at one end on the inner wall of the horizontal coil 2 and at the other end on the inner wall of the vertical coil 3.

[0043] In order to avoid measurement errors, the horizontal coil 2 and the vertical coil 3 need to satisfy the principle of equal magnetic flux, in the embodiment, the horizontal coil 2 and the vertical coil 3 are mutually sleeved, and the horizontal coil 2 and the vertical coil 3 are the same size and have the same number of turns. Due to the reason of sleeving, there is an eccentricity of about the thickness of the wire package between the two groups of coils, because the thickness of the wire package is relatively small (about 10 2 orders of magnitude) compared with the diameter of the coil, it belongs to a quasi-concentric combination of coils.

[0044] The horizontal coil 2 and the vertical coil 3 are both wound with copper wire of diameter 0.5 mm coated with polytetrafluoroethylene insulating film, with 20 turns wound in the clockwise direction, the outer diameter of the coil support framework is Φ300 mm, that is, the inner diameter of the horizontal coil 2 and the vertical coil 3 is Φ300 mm, after winding, the glass fiber bundle is tightly fixed by dipping epoxy resin, the radial thickness of the wire package (including the wall thickness of the support framework) is 6 mm, and the width is 12 mm.

[0045] The application method of the independent detection device of the embodiment will be described below, as shown in Figure 5As shown, comprising the following steps:

[0046] S1) install the independent detection device at the target position of the reactor, in this embodiment, for the reactor magnetic field monitoring condition under the working condition of the 500 kVA power grid reactor, the target position is 500 mm away from the bottom of the reactor in the height direction, and 1200 mm away from the outer package surface of the reactor in the radial direction. The independent detection device is horizontally installed on the insulating column through the mounting hole, and then the turn-to-turn short circuit monitoring system is connected to the incoming line end Tz of the horizontal coil 2, the common end T of the horizontal coil 2 and the vertical coil 3, and the outgoing line end Tr of the vertical coil 3 through the terminal post. C

[0047] S2) obtain the incoming line end induced voltage u z of the horizontal coil 2, the common end induced voltage u Σ of the horizontal coil 2 and the vertical coil 3, and the outgoing line end induced voltage u r of the vertical coil 3.

[0048] S3) calculate the modulus of the magnetic induction intensity at the target position according to the induced voltage u Σ , and calculate the magnetic induction intensity vector at the target position according to the induced voltages u z and u r . The calculation of the modulus of the magnetic induction intensity according to the induced voltage and the calculation of the magnetic induction intensity vector according to the induced voltage are both methods commonly used by those skilled in the art, and the present scheme does not involve improvements to the specific calculation process, so the specific calculation process will not be described here.

[0049] S4) if the modulus of the magnetic induction intensity at the target position is greater than a preset value, the reactor has a turn-to-turn short circuit fault, and the turn-to-turn short circuit position is determined according to the corresponding magnetic induction intensity vector.

[0050] The common end induced voltage value of the horizontal coil 2 and the vertical coil 3 under the rated load working condition of the 500 kVA reactor is 12V, which is used as the reference voltage signal for monitoring the magnetic field change of the turn-to-turn short circuit monitoring system in this embodiment, so the preset value is specifically 12V. When the common end induced voltage u Σ calculated in step S3 is greater than 12V, the turn-to-turn short circuit position is determined through the corresponding magnetic induction intensity vector. As known from the foregoing, since the magnetic field of the reactor when there is a turn-to-turn short circuit is the current loop magnetic field of the turn-to-turn short circuit superimposed on the original magnetic field of the reactor, the turn-to-turn short circuit position can be deduced according to the change direction of the magnetic field vector at the target position. The related deduction process is well known to those skilled in the art, and the present scheme does not involve improvements to the specific deduction process, so the specific deduction process will not be described here.

[0051] Embodiment Two

[0052] This embodiment is basically the same as embodiment one, the difference is that, as shown in​Figure 6 As shown, in this embodiment, the horizontal coil 2 is sleeved outside the vertical coil 3. Correspondingly, in this embodiment, the support member 4 adopts an orthogonal support tube to form a "+" shaped support frame to ensure that the horizontal coil 2 and the vertical coil 3 are concentric and perpendicular to each other. Reinforcing ribs are provided between the support tubes. In order to reduce weight, circular weight-reducing holes are provided in both the horizontal and vertical support tubes in this embodiment.

[0053] To satisfy the principle of equal magnetic flux, in this embodiment, the vertical coil 3 has more turns than the horizontal coil 2. Specifically, in this embodiment, both the horizontal coil 2 and the vertical coil 3 are wound with insulated enameled copper wire (0.3mm in diameter) in a counterclockwise single-layer winding. The inner diameter of the horizontal coil 2 (i.e., the outer diameter of the horizontal support tube) is Φ400mm, and it has 20 turns. The inner diameter of the vertical coil 3 (i.e., the outer diameter of the vertical support tube) is Φ380mm, and it has 22.2 turns, thus ensuring that the magnetic flux areas of the horizontal coil 2 and the vertical coil 3 are equal. After winding, the surface is coated with epoxy resin and cured and sealed at room temperature.

[0054] The application method of the independent detection device in this embodiment is basically the same as that in Embodiment 1. The difference is that this embodiment is used for monitoring the magnetic field conditions of the reactor under the working condition of a 30kVA reactor in the power grid. The target position is 150mm away from the bottom of the reactor in the height direction and 400mm away from the outer surface of the reactor in the radial direction. The preset value is the induced voltage value of the common terminal of the horizontal coil 2 and the vertical coil 3 under the rated load condition of the 30kVA reactor, specifically 6.5V.

[0055] Example 3

[0056] This embodiment is basically the same as Embodiment 2, except that, as Figure 7 As shown, in this embodiment, both the horizontal coil 2 and the vertical coil 3 are wound with polytetrafluoroethylene copper wire (0.5 mm in diameter) in a counterclockwise stacked manner. The horizontal coil 2 has an inner diameter (i.e., the outer diameter of the horizontal support tube) of Φ280 mm and 25 turns, prepared using a process of tightly winding 5 turns counterclockwise and stacking 5 layers. The vertical coil 3 has an inner diameter (i.e., the outer diameter of the vertical support tube) of Φ200 mm and 53.1 turns, prepared using a process of tightly winding 6 turns counterclockwise and stacking 9 layers, thus ensuring that the magnetic flux area of ​​the horizontal coil 2 and the vertical coil 3 is equal. After winding, the surfaces are coated with epoxy resin and cured and sealed at room temperature.

[0057] The application method of the independent detection device of the embodiment is basically the same as that of embodiment two, and the difference lies in that the embodiment is used for the reactor magnetic field monitoring condition of the power grid 20000 kVA reactor working condition, the target position is 100 mm away from the height direction of the bottom of the reactor and 1200 mm away from the radial direction of the outer package surface of the reactor; and the preset value is the common end induced voltage value of the horizontal coil 2 and the vertical coil 3 under the rated load working condition of the 20000 kVA reactor, and specifically 25.5 V.

[0058] The above is only the preferred embodiment of the present application, and does not limit the present application in any form. Although the present application has been disclosed as above with the preferred embodiment, it is not intended to limit the present application. Therefore, any simple modification, equivalent change and modification of the above embodiment according to the technical essence of the present application, which does not deviate from the technical solution of the present application, shall fall within the protection scope of the technical solution of the present application.

Claims

1. A stand-alone probe device for monitoring the magnetic field of a reactor, characterized in that, The application relates to a separate detecting device for detecting turn-to-turn short circuit of a reactor, which comprises horizontal coils (2) and vertical coils (3) arranged on a base (1), the planes of the horizontal coils (2) and the vertical coils (3) are perpendicular to each other, the centers of the horizontal coils (2) and the vertical coils (3) coincide, the axis of the horizontal coils (2) is along the radial direction of the reactor, the axis of the vertical coils (3) is parallel to the central axis of the reactor, the separate detecting device is installed at a target position of the reactor, if the modulus of the magnetic induction intensity of the common end induced voltage u Σ of the horizontal coils (2) and the vertical coils (3) is greater than a preset value, the reactor appears turn-to-turn short circuit fault, the magnetic induction intensity vector is calculated according to the incoming line end induced voltage u z of the horizontal coils (2) and the outgoing line end induced voltage u r of the vertical coils (3), and the turn-to-turn short circuit position is determined.

2. The stand-alone probe device for monitoring the magnetic field of a reactor according to claim 1, characterized in that, Supporting piece (4) is supported in the inner wall of horizontal coil (2) and vertical coil (3).

3. The stand-alone probe for monitoring the magnetic field of a reactor according to claim 1, characterized in that, The horizontal coil (2) and the vertical coil (3) are sleeved with each other, and the horizontal coil (2) and the vertical coil (3) are the same size and have the same number of turns.

4. The stand-alone probe for monitoring the magnetic field of a reactor according to claim 3, characterized in that, The horizontal coil (2) and the vertical coil (3) are both wound in a clockwise direction with copper wire of diameter 0.5 mm.

5. The stand-alone probe for monitoring the magnetic field of a reactor according to claim 1, characterized in that, The horizontal coil (2) is sleeved outside the vertical coil (3), and the number of turns of the vertical coil (3) is greater than that of the horizontal coil (2).

6. The stand-alone probe for monitoring the magnetic field of a reactor according to claim 5, characterized in that, The horizontal coil (2) and the vertical coil (3) are both wound in a counterclockwise direction with copper wire of diameter 0.3 mm, the horizontal coil (2) has a winding inner diameter of Φ400 mm and a winding number of turns of 20 turns, and the vertical coil (3) has a winding inner diameter of Φ380 mm and a winding number of turns of 22.2 turns.

7. The stand-alone probe for monitoring the magnetic field of a reactor according to claim 5, characterized in that, The horizontal coil (2) and the vertical coil (3) are both wound in a counterclockwise direction with copper wire of diameter 0.5 mm, the horizontal coil (2) has a winding inner diameter of Φ280 mm and a winding number of turns of 25 turns, and the vertical coil (3) has a winding inner diameter of Φ200 mm and a winding number of turns of 53.1 turns.

8. The method for using the independent detection device for monitoring the magnetic field of a reactor according to any one of claims 1 to 7, characterized in that, The method comprises the following steps: S1) install the independent detection device at the target position of the reactor, connect the incoming line end of the horizontal coil (2), the common end of the horizontal coil (2) and the vertical coil (3), and the outgoing line end of the vertical coil (3) respectively; S2) acquiring the incoming line end induced voltage u of the horizontal coil (2) z , the common end induced voltage u of the horizontal coil (2) and the vertical coil (3) Σ , the outgoing line end induced voltage u of the vertical coil (3) r ; S3) calculating the modulus of the magnetic induction at the target position from the induced voltage u Σ calculating the modulus of the magnetic induction at the target position from the induced voltage u z and u r calculating the modulus of the magnetic induction at the target position from the induced voltage u S4) if the modulus of the magnetic induction intensity at the target position is greater than the preset value, the reactor has a turn-to-turn short circuit fault, and the turn-to-turn short circuit position is determined according to the corresponding magnetic induction intensity vector.

9. The application method of the independent detection device for reactor magnetic field monitoring according to claim 8, wherein: When the reactor is a 500kVA reactor, the target position is 500mm away from the bottom of the reactor in the height direction and 1200mm away from the outer package surface of the reactor in the radial direction; When the reactor is a 30kVA reactor, the target position is 150mm away from the bottom of the reactor in the height direction and 400mm away from the outer package surface of the reactor in the radial direction; When the reactor is a 20000kVA reactor, the target position is 100mm away from the bottom of the reactor in the height direction and 1200mm away from the outer package surface of the reactor in the radial direction.

10. The application method of the independent detection device for reactor magnetic field monitoring according to claim 8, wherein: When the reactor is a 500kVA reactor, the preset value is 12V; When the reactor is a 30kVA reactor, the preset value is 6.5V; When the reactor is a 20000kVA reactor, the preset value is 25.5V.

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