JP2006211756A - Failure indicator of power system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a failure indicator that can easily confirm a failure from afar by using a large indication plate and indicate it, even if a failure current is small. <P>SOLUTION: There are provided in the failure indicator a coil 11 that detects a current flowing to a grounding wire 1 and an electric circuit 2 that rectifies an induction current of the coil 11 and outputs a secondary current. The secondary current of the electric circuit 2 is output to a solenoid 3. A magnetism reaction part 21 of the solenoid 3 is fixed to one end 26 of a movable member 4, and a failure indication member 5 is engaged with the other end 27. The induction current generated on the basis of the failure current is converted to the secondary current, and output to a drive coil 22 of the solenoid 3. A force attracting the magnetism reaction part 21 by a magnet 23 of the solenoid 3 by the secondary current is reduced, the engagement state between the other end 27 of the movable member 4 and the failure indication member 5 is released, and the failure indication member 5 is brought into a failure indication state. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a failure display device that detects a failure current flowing in a ground line attached to a power system and displays a failure in the power system.

  Power equipment such as transformers and power cables installed in the power system is grounded, and when the equipment fails, a fault current flows through the ground line. Therefore, if it is possible to identify the faulty device by detecting the current flowing through the ground line, it is convenient for early detection and repair of the faulty device.

  For example, Japanese Patent Application Laid-Open No. 54-63335 is cited as a conventional technique related to a fault display device for a power system. FIG. 6 is a view showing an application example of a conventional failure display device, and FIG. 7 is a perspective view showing a conventional reverse display applied to the failure display device of FIG. In FIG. 6, the R-phase conducting wire 121 is covered with an insulator 122 in the cable section 102 </ b> R. The outer periphery of the insulator 122 is covered with a shielding tape 123. The shielding tape 123 is connected to the ground line 124 and is grounded through a low resistance 103 that does not hinder the grounding effect.

  The low resistance 103 is provided with a shunt 107 by a parallel circuit. In the parallel circuit, a semi-fixed resistor 104 having a predetermined resistance value and an inversion display 106 including a magnetic holding element 105 are connected in series. The low resistance 103, the semi-fixed resistance 104, the magnetic holding element 105, and the reverse display 106 constitute a failure display device. Similarly, the shielding tapes for the S-phase conductor and the T-phase conductor are grounded by ground lines 125 and 126, respectively, and a fault display device is provided for each of the ground lines 125 and 126. These failure display devices are fixed and accommodated in the failure display device box 120.

  When a failure occurs in the R-phase conductor 121 in the cable section 102R, a failure current i flows through the ground wire 124, and a current that is prorated by the resistance ratio between the resistors 103 and 104 flows through the shunt 107. When the magnetic holding element 105 is operated by the current flowing through the resistor 104, the reverse display 106 is reversed to indicate that the dielectric breakdown has occurred in the cable section 102R.

  In FIG. 7, the reversing display 106 is a magnetic reversing display, and is mainly composed of a U-shaped iron core 111 inserted into a coil 112 and a display plate 113 disposed between both sides of the U-shaped iron core 111. ing. The display board 113 is rotatably supported by a rotating shaft 114. The display plate 113 is provided with an N pole and an S pole with the rotation axis 114 as symmetry. In FIG. 7A, the front surface of the display plate 113 is black, for example, and the back surface is provided with colors such as yellow, red, and green.

  The S pole and N pole of the display plate 113 are drawn by the N pole and S pole of the U-shaped iron core 111, respectively, to display a black surface. In this state, when a pulse current is passed through the coil 112 to change the polarity of the U-shaped core 111, the display plate 113 is inverted and a failure display state in which a color surface, for example, a red surface is displayed as shown in FIG. It becomes. Since the U-shaped iron core 111 maintains its polarity once it is magnetized, a pulse current in the opposite direction may be passed through the coil 112 if it is desired to display the original color plane.

  Note that such a magnetic reversal display device needs to be able to reverse the display panel with relatively small energy by using electric energy or magnetic energy.

JP 54-63335 A

  However, the above prior art has the following problems. That is, in the electric power system, the fault current (ground fault current) flowing through the ground line is small and may not reach several amperes (A). In the prior art that uses the fault current directly for the display plate reversal force of the fault display device Since the output energy is small, only a magnetic reversal display with a small display area can be applied, and there is a problem that the application range is limited. In this case, it is difficult to confirm that a failure has occurred from a distance.

  The present invention has been made in view of such problems, and even if the fault current flowing through the grounding wire is small, the fault display can be displayed by operating a large fault display board, and the fault display can be displayed even from a distance. An object of the present invention is to provide a power system failure display device that can be easily confirmed.

  A fault display apparatus for a power system according to the present invention includes a detection coil that detects a current flowing in a ground line attached to the power system, an electric circuit that rectifies the induced current of the coil to generate a secondary current, and one end A movable member provided with a magnetic reaction part and an engagement part at the other end, a magnet that exerts a magnetic force on the magnetic reaction part so that the magnetic reaction part is always in the first position, and the secondary A drive coil that exerts a magnetic force on the magnetic reaction part so that the magnetic reaction part moves to a second position by an electric current, and engages with the engagement part when the magnetic reaction part is in the first position. An engaging member that moves from the engaging portion to the third position when the magnetic reaction portion moves to the second position; and a failure indication member attached to the engaging member. Features.

  In this case, the movable member includes a rotating portion that rotates about a rotation axis, and a spring that biases the rotating portion toward the second position by the magnetic reaction portion. Can be.

  The electrical circuit includes a rectifier circuit that rectifies the induction current of the coil, and a settling circuit that generates a secondary current when an output voltage from the rectifier circuit becomes equal to or higher than a set value. Is preferred.

  Furthermore, the failure display member is normally housed in a housing having a display window, and when the engagement member is detached from the engagement portion and moved to the third position, the failure display member is removed from the display window. It can be exposed.

  Furthermore, it is preferable that the engagement member and the failure indication member are urged toward the third position by a spring.

  According to the power system fault display device of the present invention, when the power system fails and a fault current flows through the ground line, the magnetic reaction part of the movable member that is in the first position is in the second position. Since the engagement state between the movable member and the engagement member is canceled and the failure display member attached to the engagement member is in a failure display state, if a failure current greater than a predetermined value flows It is possible to display a uniform failure regardless of the current value. Therefore, it is possible to make it easier to confirm from a distance by applying a larger failure display member than in the past.

  According to the power system fault display device according to claim 2 of the present application, the spring biases the rotating portion of the movable member so that the magnetic reaction portion is in the second position, and therefore the ground wire flows through the drive coil. When a secondary current based on the fault current flows, the magnetic reaction portion of the movable member can be quickly moved to the second position, and the engagement state between the movable member and the engagement member can be reliably canceled.

  According to the fault display device of the power system according to claim 3 of the present application, when the induced current of the coil that detects the fault current flowing through the ground line is rectified by the rectifier circuit, and the output voltage of the rectifier circuit becomes equal to or higher than the set value. Since the secondary current is output from the settling circuit, the secondary current based on the fault current can be reliably output to the magnetic reaction part of the movable member.

  According to the power system fault display device according to claim 4 of the present application, when the engaging member is disengaged from the movable member, the fault display member is exposed from the display window of the housing, so it is ensured that a fault has occurred in the power system. Can be displayed.

  According to the failure display device of the power system according to claim 5 of the present application, when the engagement state between the movable member and the engagement member is canceled, the engagement member and the failure display member are moved to the third position, for example, the lower side by the spring. Since it is energized, the failure display member can be moved to expose the failure display portion of the failure display member from the display window of the housing, and an accurate failure display can be performed.

  Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a diagram showing a power system failure display device according to an embodiment of the present invention, and FIG. 2 is a front view of the failure display member of FIG.

  In FIG. 1, this failure display device includes a detection coil 11 that detects a failure current flowing through the ground wire 1, an electrical circuit 2 that rectifies the induced current of the detection coil 11 and outputs a secondary current, and an electrical circuit 2. The solenoid 3 provided with the iron core 21 as the magnetic reaction part that receives the magnetic force from the coil 22 and the magnetic force from the coil 22, and the iron core 21 of the solenoid 3 are fixed to one end 26 and engaged with the other end 27. The movable member 4 mainly includes the movable member 4 provided with the portion 28 and the failure display member 5 engaged with the engaging portion 28 of the movable member 4 via the engaging member 30.

  This power system fault display device operates a fault display member by a force stored in a spring member using a fault current as a trigger.

  The ground wire 1 electrically grounds a power system (not shown). The electric circuit 2 includes a rectifier circuit 2a and a settling circuit 2b. The rectifier circuit 2a is provided with a resistor R1 having a predetermined size, a limiter 12 whose output is constant with respect to an input exceeding a limit value, and a rectifier 13 for converting an alternating current into a direct current. The settling circuit 2b is provided with a capacitor 14, a resistor R2 having a predetermined size, a settling unit 15, and a switch 16.

The fault current I ₁ flowing through the ground line 1 is detected by a detection coil 11 as a converter. The induced current I ₂ flowing through the detection coil 11 flows into the rectifier 13 through the limiter 12 and is rectified to charge the capacitor 14 of the settling circuit 2b. When the charging voltage reaches a preset set value, an ON signal is output from the settling unit 15 to the switch 16. When the ON signal is output, the switch 16 operates in response to this, and the secondary current flows to the drive coil 22.

  An iron core 21 as a magnetic reaction part is disposed in the solenoid 3, and a magnet 23 that applies a magnetic force to the iron core 21 is attached so that the iron core 21 is always in the first position. The iron core 21 is inserted into, for example, a cylindrical hollow portion of the drive coil 22, and both ends of the drive coil 22 are connected to the output ends A and B of the settling circuit 2b described above, respectively. Therefore, the iron core 21 is movable with respect to the drive coil 22. When the switch 16 of the settling circuit 2b is activated and the secondary current from the settling circuit 2b flows to the drive coil 22, the magnetic force acting on the iron core 21 of the magnet 23 is canceled out.

  One end of the iron core 21 is fixed to one end 26 of the movable member 4. The movable member 4 is provided such that the rotating portion 4a rotates about the rotating shaft 25. The rotating portion 4a includes, for example, a long side portion and a short side portion with the rotating shaft 25 as a boundary. Has a shape intersecting at right angles. The iron core 21 is fixed to, for example, an end portion on the long side portion side. In addition, it is good also considering the side which fixes the iron core 21 as a short side part side. The difference between fixing the iron core 21 to the end on the long side portion side of the movable member 4 or fixing to the end portion on the short side portion side is that the thickness of the housing for accommodating the apparatus increases, or The only difference is in length.

  The other end 27 of the rotating portion 4a of the movable member 4 is provided with an engaging portion 28 formed of a notch, and one end of an engaging member 30 fixed to the failure display member 5 is provided in the engaging portion 28. It is designed to be engaged. One end of a tension spring 29 is fixed to the other end 27 of the movable member 4. The other end of the spring 29 is fixed to, for example, a fixed member.

The spring 29 biases the other end 27 of the rotating portion 4 a of the movable member 4 in a direction toward the second position where the iron core 21 is separated from the magnet 23. In the rotating part 4 a of the movable member 4, the attractive force f ₁ of the magnet 23 acting on the iron core 21 of the solenoid 3 and the restoring force f _{2 of the} spring 29 are relatively f ₁ > f ₂ . Next, when the secondary current from the settling circuit 2b flows through the drive coil 22 of the solenoid 3 and the force acting on the iron core 21 of the magnet 23 is canceled, the restoring force of the spring 29 becomes relatively large and f _{1 <f 2,} and the other end 27 of the movable member 4 is moved to the right in the figure, the locking state is released and the engaging member 30 fixed to the engagement portion 28 and the fault indication member 5 of the movable member 4 Is done.

The engaging member 30 is connected to the failure display member 5 through a connecting rod 31 arranged horizontally, for example. One end of a spring 32 is fixed to the engaging member 30, the connecting rod 31, and the connecting portion, and the other end of the spring 32 is fixed to a lower fixing member in FIG. Thus the engaging member 30 coupled to the fault display member 5 is pulled in one direction at all times with a force of f ₃ by the spring 32, i.e., downward in FIG. Therefore, when the engagement state between the engagement member 30 and the engagement portion 28 of the movable member 4 is released, the engagement member 30 is pulled downward together with the failure display member 5, and the failure display member 5 fails as described later. Display state.

  Note that a switch 33 that contacts a part of the engagement member 30 may be disposed below the engagement member 30, and the switch 33 may be moved to obtain an external output when the engagement member 30 is lowered. .

  In FIG. 2, the failure display member 5 is always housed in a housing 36 having a display window 35. An engagement member 30 is fixed to the failure display member 5, and the engagement member 30 is urged so as to be pulled downward by the spring 32 together with the failure display member 5.

  The upper half of the failure display member 5 is colored, for example, yellow, red, green, and the lower half is colored, for example, black. Therefore, when the engagement state between the engagement member 30 and the engagement portion 28 of the movable member 4 is released, the failure display member 5 is pulled downward by the spring 32 and the display window 35 of the housing 36 is not black except for the upper half. The colored surface is exposed, indicating that a failure has occurred in the power system.

  Such a power system failure display device is attached to a power cable, for example, and used as a power cable failure display device. FIG. 3 is a diagram illustrating a state in which a failure display device is arranged on the power cable. In FIG. 3, power cables 41, 42 and 43 are provided. Each power cable is mainly composed of power lines 41a, 42a, 43a and an insulating layer (not shown) covering these power lines. Each power line 41a, 42a, 43a is shielded by a metal shield 41b, 42b, 43b, and each metal shield 41b, 42b, 43b is grounded by a ground wire 41c, 42c, 43c, respectively.

  Coils 41d (CT1), 42d (CT2), and 43d (CT3) for detecting a fault current of the corresponding fault display device are disposed on the ground lines 41c, 42c, and 43c, and each coil is shown in FIG. It is connected to the failure display device 45 configured as described above.

  Hereinafter, referring to FIG. 1 and FIGS. 4 (a) and 4 (b) which are diagrams showing the operation of the solenoid, according to this embodiment configured as described above and arranged with respect to the ground line of the power cable. The operation of the failure display device will be described.

When the insulating layer is not shown of the power cable 41 is broken by aged deterioration, the fault current I ₁ flows to the ground line 41c, the detection coil 41d as a transducer senses the fault current. At this time, the induced current I ₂ flows through the sensing coil 41d, the induction current I ₂ is rectified and flows to the rectifier 13 via the limiter 12 in FIG. 1, charges the capacitor 14 of the settling circuit 2b. When the charging voltage reaches a preset set value, an ON signal is output from the settling unit 15 to the switch 16. An ON signal is output response to this operating switch 16 of the settling circuit 2b, the driving coil 22 an iron core 21 of the solenoid 3 is inserted through the secondary current I _3.

By the way, as shown in FIG. 4A, the iron core 21 of the solenoid 3 is always subjected to a downward acting force by the magnetic flux Φ ₁ generated by the permanent magnet as the magnet 23, and the iron core 21 is applied to the magnet 23. The attracted first position is maintained. However, when the secondary current I ₃ flows through the drive coil 22, the magnetic flux Φc generated by the current I ₃ cancels the magnetic flux Φ ₁ described above, thereby reducing the attractive force f ₁ of the magnet 23 acting on the iron core 21.

When the attracting force f ₁ of the magnet 23 is small, the restoring force f ₂ of the spring 29 acting on the other end 27 is relative to the force f ₁ attracting the iron core 21 acting on one end of the movable member 4 downward. The other end 27 of the movable member 4 moves to the right in FIG. By the movement of the other end 27, the engagement state between the engagement portion 28 and the engagement member 30 of the movable member 4 is released, and the engagement member 30 is pulled downward together with the failure display member 5 by the spring 32. When the failure display member 5 is pulled downward, as shown in FIG. 2, the colored portion other than the black color on the upper side of the failure display member 5 is exposed from the display window 35, and a failure occurs in the power cable 41. Is displayed.

  According to the present embodiment, when the power cable 41 fails and a fault current flows through the ground line 41c, the detection coil 41d detects the fault current, and the secondary current based on the fault current is driven to the solenoid 3. Output to the coil 22, thereby reversing the force acting on both ends of the movable member 4, and releasing the engagement state between the engagement portion 28 of the movable member 4 and the engagement member 30 connected to the failure indication member 5. Since the failure display member 5 is in the failure display state, uniform failure display can be performed regardless of the magnitude of the failure current. Therefore, the use of a large failure display board can facilitate confirmation from a distance.

  Further, according to the present embodiment, the induced current generated in the detection coil 11 due to the fault current is rectified by the rectifier circuit 2a, and when the output voltage becomes equal to or higher than the set value, the settling circuit 2b to the solenoid 3 Since the secondary current is output to the drive coil 22, the secondary current based on the fault current can be reliably output to the solenoid.

  Furthermore, according to the present embodiment, the spring 29 is provided to urge the rotating portion 4a of the movable member 4 so that the iron core 21 moves from the first position to the second position. When a secondary current based on the failure current flows through the drive coil 22, it is possible to reliably release the engagement state of the movable member 4 and the engagement member 30 and to display the failure display by the failure display member 5.

  Furthermore, according to the present embodiment, when the engaging member 30 is disengaged from the engaging portion 28 of the movable member 4, the failure indicating member 5 is biased to the third position, for example, downward by the spring 32. Since the failure display portion of the display member 5 is exposed from the display window 35 of the housing 36, when a failure occurs in the power system, the failure display can be performed reliably.

  Furthermore, according to the present embodiment, since the failure display devices are disposed on the ground lines 41c, 42c, and 43c of the power cables 41, 42, and 43, for example, it is possible to identify a power cable that has undergone dielectric breakdown.

  In the above embodiment, the case where the failure display device is provided on the ground line corresponding to each power cable has been described. However, the present invention is not limited to this, for example, common to three ground lines. A failure display device can also be arranged. In this case, it can be detected that one of the three power cables has failed.

  In the above embodiment, the position where the iron core 21 of the solenoid 3 is attracted (magnetized) to the magnet 23 is the first position, a fault current flows through the ground wire 1, and the secondary current from the electric circuit 2 is The case where the position of the iron core 21 when the force applied to the iron core 21 by the magnet 23 described above flows to the drive coil 22 of the solenoid 3 is canceled is described as the second position, but FIG. ), Another magnet 24 is mounted on the side of the magnet 23 of the iron core 21, and the two magnets are opposed so that they repel each other, and the winding method of the drive coil 22 is changed to change the normal iron core 21. The second position of the iron core 21 when the secondary current flows through the movable coil 22 is attracted to the magnet 23 (the magnetic position). The iron core 21 moves to this second position. The engagement between the movable member 4 and the engaging member 30 may be is opened when.

  Furthermore, in the said embodiment, although the iron core 21 was inserted in the drive coil 22 of the solenoid 3 and it was set as the structure which the iron core 21 can move with respect to the drive coil 22, the iron core 21 and the drive coil 22 are electrically connected. If it is in an insulated state, the drive coil 22 may be wound around the iron core 21 and the iron core 21 may move toward the magnet 23 together with the drive coil 22.

  Furthermore, in the above embodiment, the movable member 4 is such that the rotating portion 4a rotates and the iron core 21 moves between the first position and the second position. For example, the movable member is a rod-shaped body that moves in one direction by a secondary current obtained by rectifying the induced current generated based on the failure current, and the engagement state with the engagement member is determined by the movement of the rod-shaped body. May be released.

  FIG. 5 is a diagram showing another embodiment of the present invention. In FIG. 5, a three-phase transformer or a three-phase power capacitor 54 is arranged for the power lines 51, 52 and 53, and the three-phase transformer or the three-phase power capacitor 54 is grounded by a ground line 54c. ing. A failure display device 60 is provided on the ground line 54c.

  A single-phase transformer or single-phase power capacitor 55 is arranged for the power lines 52 and 53, and this single-phase transformer or single-phase power capacitor 55 is grounded by a ground line 55c. A failure display device 60 is provided on the line 55c.

  In such a configuration, when the three-phase transformer or three-phase power capacitor 54 or the single-phase transformer or single-phase power capacitor 55 fails and a fault current flows through the ground line 54c or 55c, Similarly, a fault current is detected by the ground detection coil, and similarly, the solenoid 3, the movable member 4, the fault display member 5 and the like are operated to display a fault.

  According to this embodiment, since the failure display device is arranged corresponding to the power equipment such as a three-phase transformer and a single-phase transformer, the failure display device can function as a dielectric breakdown detection device for the power equipment.

  The failure display device of the present invention can display a failure with a large failure display board even if the failure current flowing through the grounding wire is small, and can confirm the failure display even from a distance. It is particularly useful in the field of system management and maintenance.

It is a figure which shows the structure of the failure display apparatus which concerns on embodiment of this invention. It is a front view of the failure display member in this embodiment. It is a figure which shows the example of application of the failure display apparatus which concerns on embodiment of this invention. It is a figure which shows operation | movement of the solenoid in this embodiment. It is a figure which shows another example of application of the failure display apparatus which concerns on embodiment of this invention. It is a figure which shows a prior art. It is a figure which shows the conventional magnetic reversal display.

Explanation of symbols

1: ground line 2: electric circuit 2a: rectifier circuit 2b: settling circuit 3: solenoid 4: movable member 4a: rotating part 5: failure display member 11: detection coil 12: limiter 13: rectifier 14: capacitor 15: settling part 16: Switch 21: Iron core (magnetic reaction part)
22: drive coil 23, 24: magnet 25: rotating shaft 26: one end 27 of the movable member 27: the other end 28 of the movable member 28: engagement portion 29: spring 30: engagement member 31: connecting rod 32: spring 33: switch 35: Display window 36: Housings 41, 42, 43: Power cables 41a, 42a, 43a: Power lines 41b, 42b, 43b: Metal shielding 41c, 42c, 43c: Grounding wires 41d, 42d, 43d: Detection coils 51, 52, 53: Power line 54: Three-phase transformer (or capacitor for three-phase power)
54c: Ground line 55: Single-phase transformer (or capacitor for single-phase power)
55c: Grounding wire 60: Fault display device 102R: Cable section 103: Low resistance 104: Semi-fixed resistance 105: Magnetic holding element 106: Inversion display 107: Shunt 111: U-shaped iron core 112: Coil 113: Display board 114: Reversing shaft 120: Failure display device box 121: R phase conductor 122: Insulator 123: Shielding tape 124-126: Ground wire

Claims (5)

  A detection coil that detects the current flowing in the grounding line attached to the power system, an electric circuit that rectifies the induced current of this coil to generate a secondary current, and a magnetic reaction part at one end, which is engaged at the other end A movable member provided with a portion, a magnet that exerts a magnetic force on the magnetic reaction portion so that the magnetic reaction portion is always in the first position, and the magnetic reaction portion is moved to the second position by the secondary current. A drive coil that exerts a magnetic force on the magnetic reaction part so as to move, and when the magnetic reaction part is in the first position, it engages with the engagement part and the magnetic reaction part moves to the second position. And a failure display member attached to the engagement member. The failure display device of the power system includes: an engagement member that disengages from the engagement portion and moves to a third position.   The movable member includes a rotating portion that rotates about a rotating shaft, and a spring that biases the rotating portion toward the second position by the magnetic reaction portion. The fault display device for a power system according to claim 1.   The electrical circuit includes a rectifier circuit that rectifies an induced current of the coil, and a settling circuit that generates a secondary current when an output voltage from the rectifier circuit becomes equal to or higher than a set value. Item 3. A power system failure display device according to Item 1 or 2.   The failure display member is normally housed in a housing having a display window, and is exposed from the display window when the engagement member is detached from the engagement portion and moved to the third position. The fault display apparatus for a power system according to any one of claims 1 to 3. 5. The power system fault display device according to claim 4, wherein the engagement member and the fault display member are biased toward the third position by a spring. 6.

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