JPS6324445Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a current detector used for detecting fault current in a distribution line made of insulated wires.

This idea consists of a current transformer that is divided into two parts in the horizontal direction and removably fitted onto an insulated wire, and the upper part of the current transformer is fixedly supported via an upper frame. A main column, a guide column provided along the main column, and a lower current transformer piece that comes into contact with and separates from the upper current transformer piece of the current transformer are fixed, and the lower current transformer piece is fixed to the guide column. A movable frame disposed to be movable in the vertical direction, an operating lever rotatably supported on the main column and disposed along the main column when the lock is operated, and one end at the bottom of the movable frame. A connecting link is rotatably supported and has a locking pin at the other end, and the other end of the connecting link is rotatably supported at the distal end, thereby forming a toggle lock mechanism together with the connecting link. By rotating the operating lever, the movable frame is moved between the unlocked position and the locked position, and when moving from the unlocked position to the locked position, the movable frame is moved upward via the connecting link, and the engagement protrusion provided at the tip The structure includes a lock lever that engages with the locking pin to hold the movable frame in a locked state, making it easy to attach and detach and enable live wire work, making it particularly useful as a current transformer for zero-sequence current detection. It is an object of the present invention to provide a current detector that can be directly attached to a distribution line when provided in each phase, unlike a zero-phase current transformer that is a three-phase all-in-one type.

Hereinafter, an embodiment in which the current detector of this invention is embodied to be capable of detecting zero-sequence current and overcurrent, and is used as a part of the entire fault section detection and display device, will be described with reference to the drawings. First, the outline will be explained according to FIGS. 1 and 2. The insulated wires 4 of each phase in the distribution line supported by the pin insulator 3 erected on the arm 2 of the utility pole 1 have zero phase, respectively. Voltage detection capacitor 5
A current detector 6 is attached to the center of the capacitor 5. A reinforcing arm provided between the telephone pole 1 and the arm 2 to support the arm 2 has a terminal for connecting the lead wire 7 led out from each capacitor 5 to one shield wire 8. In addition to the box 9 being fixed, a display 12 is fixed to the lower part of the utility pole 1 using scaffolding bolts 10 and mounting bands 11, and the display 12 is attached to the display 12 bound by the scaffolding bolts 10 at the upper position. The lead wire 13 of each detector 6 and the shield wire 8 are connected.

Next, the zero-phase voltage detection capacitor 5 will be explained in detail with reference to FIGS. It is formed so that it can be divided into two in the direction. The two capacitor pieces 21 each have a semi-cylindrical shape, and are removably opposed to each other in their planar portions and are in close contact with each other.

The inside of each capacitor piece 21 is brought into close contact with the outer peripheral surface of the insulated wire 4, and the core wire 4a of the wire 4 is
A first conductive layer 22 made of conductive rubber and having a semi-cylindrical shape so as to form a first capacitor between the conductive layer 22 and an insulating layer having an H-shape from the front that covers the outer curved surface portion of the conductive layer 22 in a semi-cylindrical shape. First insulating layer 23 made of rubber
and a second insulating layer 24 made of insulating rubber having a semi-cylindrical shape that covers the curved surface portion of the insulating layer 23, and the first conductive layer 22, both insulating layers 23, A semi-cylindrical metal second conductive layer 25 buried between the two conductive layers 24 forms a four-layer structure integrally formed, and the capacitance of the first capacitor is larger than that of the second capacitor. The location and size of the second conductive layer 25 are set.

Further, at both ends of the outer periphery of the first insulating layer 23, square plate-shaped engagement flanges 26 and 27 having different wall thicknesses are integrally formed on the upper and lower dividing surface side edges, respectively, and project in the upper and lower directions. On the side surfaces of each pair of engagement flanges 26 and 27, there are an appropriate number of locking holes 28 (four in this embodiment) each consisting of a pair of large and small holes and a slit that communicates the two holes.
are transparently installed separately. Of the upper and lower engaging flanges 26 and 27, a finger hook 29 is attached to the end of one of the thicker engaging flanges 26.
6, and its flange 2
A connecting piece 30 made of an insulating material harder than the flanges 26 and 27, such as a synthetic resin such as polyethylene resin, is fitted and locked in the locking hole 28 at 6, and the outer end of the connecting piece 30 is fitted with the flange 26. A locking portion 3 having a large diameter disk shape that is abutted against and locked to the outer surface of the
0a is formed, and a cylindrical insertion part 30b is formed in the center thereof to be fitted into the large diameter hole portion of the locking hole 28, and a conical engagement part 30b is formed in the inner end thereof. A portion 30c is formed.

Further, near the end of the other engaging flange 27, which has a thinner wall, a square plate-shaped finger hook piece 31 is provided to protrude in the direction in which the flange 27 extends. The engagement flange 26 contacts the finger hook piece 29 with a shift of about half, and the engagement flange 27 of one capacitor piece 21
It is used together with the finger hook piece 29 to disengage the connecting piece 30 of the other capacitor piece 21 from the locking hole 28 in the locking hole 28 .

Further, a support protrusion 32 is formed to protrude laterally near one end of the side surface of the second insulating layer 24, and the end of the lead wire 7 is integrally supported by molding on the support protrusion 32. A conducting wire 7a of the lead wire 7 is connected to the second conductive layer 25.

The inner diameter of the first conductive layer 22 is formed to be slightly smaller than the outer diameter of the insulated wire 4, so that the inner surface of the first conductive layer 22 can come into close contact with the outer peripheral surface of the insulated wire 4, and The length of the fitting part 30b of the connecting piece 30 is formed to be equal to or slightly shorter than the combined thickness of both engaging flanges 26 and 27,
The pair of capacitor pieces 21 can be brought into close contact with each other, especially at both ends thereof.

Next, the current detector 6 will be described in detail with reference to FIGS. 6 to 10, with the front side of the page in FIG. An upper frame 42 made of a plate material is fastened with bolts so as to extend to the right, and a fixing fitting 43 made of a plate material with an inverted L-shaped cross section is located slightly above the center thereof and extends to the lower left. The mounting brackets 44 are fitted and welded together as shown in FIG. A plate-shaped attachment piece 45 is fixed at its base end.

A support piece 46 made of a vertically long L-shaped plate is bolted to the left end of the fixing metal fitting 43 at its lower part, and a terminal block 47 is supported and fixed to the upper part of the support piece 46. In the center, a bottomless box-shaped terminal box 48 that covers the terminal block 47 from above with a predetermined gap is attached to a box fixing base 49.
A cylindrical guide column 50 is arranged in parallel at the front and rear positions between the lower end portion of the guide column 50 and the upper frame 42, and the upper and lower ends of both guide columns 50 are connected to the upper frame 42 and the upper frame 42, respectively. It is tightened and fixed to the support piece 46 with a nut.

Each guide column 50 has a cylindrical movable body 51.
is fitted loosely so that it can move up and down, and a plate-shaped connecting piece 52 is welded between the upper ends of both movable bodies 51 to move both movable bodies 51 integrally. The upper and lower surfaces of the movable body 51 are adapted to restrict the vertical movement range of the movable body 51 by contacting the lower surface of the upper frame 42 and the upper surface of the support piece 46, respectively. A movable frame 53 extending to the right is welded to the lower end of each movable body 51 at each fork-shaped end of a connecting portion 53a forming a horizontal Y-shape in plan,
At the upper end of the distal end of the connecting portion 53a in the movable frame 53, a horizontal plate-shaped attachment portion 53b is formed so as to form a T-shape on the side with respect to the distal end of the connecting portion 52a.

A channel-shaped current transformer mounting base 54 is attached to the mounting portion 53b of the movable frame 53 so as to be movable up and down.
On the lower surface of the mounting base 54, support columns 55 are provided at symmetrical positions in the front and back, respectively, and extend through the mounting portion 53b of the movable frame 53 so as to be vertically movable. A locking nut 56 is screwed onto the lower end of the support column 55, and comes into contact with the lower surface of the mounting portion 52b to restrict the upward movement range of the mounting base 54. Pillar 5
A compression spring 57 is loosely fitted in each of the mounting portions 5 to bias the mounting base 54 upwardly with respect to the mounting portion 53b.

A semicircular lower current transformer piece 58 and a horizontal L-shaped lower core piece 59 are screwed to the front and back positions of the upper surface of the mounting base 54, respectively, and are screwed to the front and rear positions of the right end of the lower surface of the upper frame 42, respectively. The upper current transformer piece 60, which is formed into a semicircle by dividing the screwed annular shape along a substantially horizontal direction, and the upper core piece 61, which has a horizontal L-shape, can be pressed against each other. . A connecting core piece 62 whose lower surface can be pressed against the upper surface of the lower core piece 59 is protruded from the open end of the lower surface of the upper core piece 61, and the core piece 62 is molded with an insulator. coil 6
A spacer 64 is interposed between the upper and lower core pieces 61, 59 and the upper frame 42 and the mounting base 54, respectively. A clamping piece 65 for clamping the zero-phase voltage detection capacitor 5 at the second insulating layer 24 portion is fixed to each inner surface, and the clamping piece 65
A fitting recess 65 a having a curved surface corresponding to the outer circumferential surface of the insulating layer 24 is formed on the inner surface of the insulating layer 24 .

The coils in each of the current transformer pieces 58, 60 are formed of conductors having a square cross section and a pair of U-shaped cross sections, as shown in FIG. Current transformer piece 58,6
0, an annular zero-sequence current detection current transformer 66 having an inner hole slightly smaller than the outer diameter of the second insulating layer 24 of the capacitor 5 is formed, and each of the core pieces 59, 61, 62 and The coil 63 forms a current transformer 67 for detecting overcurrent.

A plate-shaped guide piece 68 having a horizontal U-shape in plan is bolted to the mounting piece 45, and the upper current transformer piece 60 is held between the upper parts thereof, and a guide part 68a is provided at the lower end of the plate-shaped guide piece 68. is bent outward to insert and guide the lower current transformer piece 58, and both current transformer pieces 5
8 and 60 are surely placed in close contact with each other. Further, lead wires (not shown) led out from both current transformers 66 and 67 are connected to the 2-core shielded 4-core lead wire 13 in the terminal box 48, and the lead wire 13 is connected to a wire holder. It is supported and fixed to the box fixing base 49 by a plate 69, and is inserted into the main column 41 from its center and led out from its lower end.

A locking pin 71 is fitted and attached to the lower part of the connecting portion 52a of the movable frame 53 so as to protrude in the front-rear direction, and the upper end portion of the connecting link 72 is rotatably attached to both the front and rear portions of the locking pin 71. A connecting pin 73 is fitted and attached to the lower end portions of both links 72. The connecting pin 73
The upper end of a lock lever 74 having a bent shape at the lower part is rotatably connected to both ends of the lock lever 74, and the upper right end of the lock lever 74 is removably engaged with the locking pin 71. An engaging protrusion 75 is provided, and a shaft pin 76 is rotatably attached to the bent portion of the engaging protrusion 75, and the shaft pin 76 is fitted into and attached to both of the mounting brackets 44, and the lock lever 74 is connected to the lock shown in FIG. position and the unlocked position shown in FIG.
Also, a retaining pin 7 is provided between the lower ends of the lock lever 74.
7 is inserted and attached. A cylindrical operating lever 78 is provided between the lower portions of both lock levers 74.
The upper end portions of the two pins 76 and 77 are attached so as to be immovable relative to each other.

Note that the lower surfaces of the main pillar 41 and the operating lever 78 are coated with an insulating material such as insulating rubber, and the connecting links 72 of the connecting pin 73 are coated with an insulating material such as insulating rubber.
Spacing rings are fitted between the connecting link 72 and the lock lever 74, respectively.

Next, regarding the display unit 12, FIGS.
To explain in detail according to FIG. 3, this display 12
A terminal box 82 is provided at the bottom of the case 81, and a metal outlet 8 is provided at the top inside the terminal box 82 for connecting the lead wires 13 and shielded wires.
3 and 84 are provided, and the case 81
At the top of the lid, there is a ground fault directional relay DG on the front inside the lid.
In addition, an integration counter 85 for measuring the number of ground fault failures is provided on the front center of the case 81, and an indicator bar 86a for ground fault direction and overcurrent display is installed outside the case 81 in the center of the case 81. A solenoid 86 is provided for protruding to. Further, on the upper surface of the case 81, a ground terminal 87 and a mounting fitting 88 for hanging the case 87 from the scaffolding bolt 10 are provided, and on the back thereof, a fitting 89 for attaching to the mounting band 11 is provided.

The case 81 of the display 12 has built-in electrical components corresponding to the electrical circuit surrounded by the dashed line in FIG. The currents are passed through a transformer and a rectifier circuit, and the output currents are combined and smoothed for each phase, and the overcurrent relay 90
There is an overcurrent detection circuit connected to the Further, the current from the zero-phase current detection current transformer 66 in each phase is combined for three phases and the terminal of the ground fault direction relay DG is
There is a ground fault direction detection circuit that includes a circuit that inputs to Z ₁ and Z ₂ and a circuit that inputs the zero-sequence voltage from the shielded wire 8 to the terminal N of the relay DG. Further, the operating power input to the relay DG at terminals P ₁ and P ₂ via the surge absorber is input to the transformer, and the output of the transformer is rectified and
It is smoothed and input to the no-voltage detection relay 91 as an operating DC power source, and on the other hand, it is connected to the integration counter 85, the power supply capacitor C, and the solenoid 86 via the output terminals A and C of the relay DG. , and there is a circuit in which a diode D for preventing backflow is connected between the counter 85 and the capacitor C, and a normally closed contact X _1b of the relay 91 is connected between the capacitor C and the solenoid 86. There is a circuit connecting the solenoid 86 and the operating DC power source via the normally open contact X _0a of the current relay 90.

When the current input to the relay 90 exceeds the set value, the contact X _0a of the relay 90
is closed, and the contact X _1b of the relay 91 is opened when there is no power input thereto,
Furthermore, contacts A and C of the relay DG are short-circuited for a longer time than the time required for the substation to trip when a ground fault is detected.

Next, the operation of the entire failure section detection and display device configured as described above will be explained. First, the zero-phase voltage detection capacitor 5 will be explained. This capacitor 5 is constructed by fitting a pair of capacitor pieces 21 facing each other to the insulated wires 4 of each phase. The mating flanges 26 and 27 are brought into close contact with each other. Then, each capacitor piece 21 is immovably attached to the outer peripheral surface of the insulated wire 4 on the inner surface of the first conductive layer 22, and a second capacitor is formed between the capacitor piece 21 itself and the core wire 4a of the insulated wire 4 together with the second capacitor in the capacitor piece 21 itself. One capacitor is formed. The capacitors 5 of each phase installed in this manner detect the ground voltage of each phase, and a zero-phase voltage obtained by combining the respective ground voltages is inputted to the shielded wire 8.

Note that when detecting this ground voltage, if there is a change in the capacitance of at least one phase of the capacitors 5 for each phase, a zero-sequence current will flow to the shielded wire 8 even if there is no ground fault. There is a risk that the output will cause the ground fault directional relay DG to malfunction.
In each capacitor piece 21 of this embodiment, the capacitance of the first capacitor, which is at risk of changing capacitance due to rainwater entering between the insulated wire 4 and the first conductive layer 22, is set higher than that of the second capacitor. The capacitance as a whole is approximated to the capacitance of the second capacitor, which has no change in capacitance.

In addition, when removing the capacitor 5 from the insulated wire 4, the finger hook pieces 29 and 31 of the different capacitor pieces 21 are spread apart, and the engaging portion 30c of the connecting piece 30 provided on one of the engaging flange 26 is removed.
Since it comes off from the locking hole 28 of the other engaging flange 27, the capacitor piece 21 is separated into two parts and removed from the insulated wire 4.

Next, the current detector 6 will be explained. The operating lever 78 of this detector 6 is rotated to open and close relative to the main column 41 around the shaft pin 76, and due to this rotation, the operating lever 78 is integrally connected to the operating lever 78. The axial center of the connecting pin 73 that connects the lock lever 74 attached to the connecting link 72 and the connecting link 72 connects the axial center of the locking pin 71 that connects the connecting link 72 and the movable frame 53 with the axial center of the shaft pin 76. Dead center D (Fig. 6 and 10)
(indicated by a dashed line in the figure) in the vertical direction. Further, the rotation of the operating lever 78 is converted into vertical movement of the movable frame 53 via the lock lever 74 and the connecting link 72, and the vertical movement is performed linearly by the guide column 50 via the movable body 51.

The upward movement of the movable frame 53 is transmitted to the current transformer mount 54 against the spring force of the compression spring 57, and the upward movement of the mount 54 causes the lower current transformer piece 58 to be guided by the guide piece 68. The spring 57 can be moved without causing longitudinal and lateral displacement with respect to the upper current transformer piece 60.
At the same time, the lower core piece 59 is pressed against the upper core piece 61, and the zero-sequence current detection current transformer 66 and the overcurrent detection current transformer 67
form. The upward movement of the movable frame 53 is toggled in a state in which the engaging protrusion 75 of the lock lever 74 is engaged with the locking pin 71, and when both the core pieces 59 and 61 are pressed together, the connecting core piece The lower surface of 62 is pressed against the lower core piece 59 to form a core with low magnetic resistance.

On the other hand, the downward movement of the movable frame 53 is carried out with the help of the spring force of the compression spring 57 as soon as the axis of the connecting pin 73 passes the dead center D, and the downward movement is carried out when the lower surface of the movable body 51 touches the upper surface of the lower part of the support piece 46. The current transformer pieces 58 and 60 (both core pieces 59 and 61
The same applies to the case of 2)), which is larger than the outer diameter of the simple cylindrical central portion of the capacitor 5.

Now, when attaching this current detector 6 to the insulated wire 4, first, as shown in FIG.
The capacitor 5 is loosely fitted into the center of the capacitor 5 from the outside using its dielectric strength, and the upper current transformer piece 60 and the upper clamping piece 65 are fitted and locked from above. In this state, since the upper current transformer piece 61 and the upper clamping piece 65 are divided substantially horizontally and formed into a semicircular shape, the current detector 6 can be temporarily fixed stably. In this state, the operating lever 78 is closed by tilting it at a predetermined angle with respect to the vertical line, if necessary, taking into account the influence of wind and rain. Then, the center portion of the capacitor 5 is held between the current transformer pieces 58, 60 and the holding pieces 65 in a slightly contracted state, so that the current detector 6 is fixed to the capacitor 5, and the current detector 6 is fixed to the capacitor 5. Both current transformers 66 and 67 are formed, and each current transformer 66 and 67 outputs a transformed current to the display 12, respectively.

Note that if the operating lever 78 is opened in the above state, the output to the display will disappear and the capacitor 5 can be removed, and the operating lever 78
In the case where the capacitor 5 is opened and locked, or when the capacitor 5 is clamped, the engagement flanges 2 at both ends of the capacitor 5 remain even if the current detector 6 is moved in the axial direction with respect to the capacitor 5.
6, 27 prevents the current detector 6 from coming off the capacitor 5.

Next, the indicator 12 that receives the outputs of the capacitors 5 and detectors 6 for each phase will be explained. First, if a ground fault occurs in the distribution line where the insulation recovers in a shorter time than it would take for the substation to trip. Since _the operating power is not lost, the contact
works and counts once.

Next, when a ground fault occurs in the distribution line that causes the substation to trip, no current flows to the no-voltage detection relay 91, so its contact _X1b closes, and the current is stored in the power supply capacitor C. Electricity is passed through the solenoid 86 to cause the indicator bar 86a to become the indicator 1.
The second case 81 is protruded and locked, and the counter 85 counts the number in the same manner as described above.

Furthermore, when an overcurrent flows in the distribution line, the current flowing through the overcurrent relay 90 exceeds the set value, so the relay 90 operates and contacts X _0a
is closed, and the solenoid 86 is operated to project the display bar 86a.

As detailed above, in this invention, the upper current transformer piece is divided almost horizontally, so the current detector can be temporarily fixed stably, making the installation work easier. can be done.
In addition, it is easy to attach and detach to and from insulated wires on distribution lines, making it possible to work with live wires, and when attached to insulated wires, the toggle lock mechanism ensures that the current transformer piece is securely and stably attached to the distribution line. Therefore, the current transformer will not be displaced relative to the distribution line, and will not be affected by wind pressure on the pole. In addition, especially when it is installed on each phase as a current transformer for zero-sequence current detection, it is not necessary to connect all three phases at once, so it can be installed directly on the distribution line, which is a practical idea that is preferable as a current detector. It is.

It should be noted that this invention is not limited to the above-mentioned embodiments, and may include further providing a cushion material such as an insulator or rubber on the inner surface of each current transformer piece and each core piece, or utilizing the dielectric strength of the insulated wire. It can be attached directly to an insulated wire, a current transformer can be added to take out the operating power as a current transformer, or only the current transformer 7 can be used as a current transformer to detect either zero-sequence current or overcurrent. Any changes can be made without departing from the spirit of this invention, such as by changing the structure and shape of each part as necessary.

[Brief explanation of the drawing]

Fig. 1 is a front view showing the installation state of an embodiment of this invention together with the entire failure section detection and display device, Fig. 2 is a side view showing the same installation state, and Figs. A phase voltage detection capacitor is shown, with FIG. 3 being an exploded perspective view thereof, FIG. 4 being a plan sectional view thereof, and FIG. 5 being a side sectional view thereof.
Figures 6 to 10 similarly show the current detector, Figure 6 is its front view, and Figure 7 is approximately X-X of Figure 6.
8 is a side view thereof, FIG. 9 is a sectional view taken approximately along the line Y--Y in FIG. 8, and FIG. 10 is a front view showing the opened state. Figures 11 and 12 also show the display unit, and Figure 11 is its front view, and Figure 1
Figure 2 is a side view of the same. FIG. 13 is also an overall electrical circuit diagram. Insulated wire...4, Current detector...6, Main pillar...
41, Upper frame...42, Guide column...50, Movable body...
...51, Movable frame...53, Current transformer mounting base...5
4, Support column...55, Compression spring...57, Lower current transformer piece...58, Lower core piece...59, Upper current transformer piece...60, Upper core piece...61, Connection core piece... ...62, Coil...63, Current transformer for zero-phase current detection, Current transformer for overcurrent detection...67, Locking pin...
71, Connecting link...72, Lock lever...7
4. Engaging protrusion...75, operating lever...78.

Claims (1)

[Scope of Claim for Utility Model Registration] A current transformer that is divided into two parts in a substantially horizontal direction and removably fitted onto an insulated wire; A main column fixedly supported through the main column, a guide column provided along the main column, and a lower current transformer piece that comes into contact with and separates from the upper current transformer piece of the current transformer is fixed, and the lower current transformer piece is fixed to the upper current transformer piece. a movable frame disposed to be movable in the vertical direction with respect to the guide column; an operating lever rotatably supported on the main column and disposed along the main column when the lock is operated; A connecting link has one end rotatably supported at the bottom of the frame and a locking pin at the other end, and the other end of the connecting link is rotatably supported at the tip, thereby creating a toggle lock mechanism together with the connecting link. The movable frame is moved between the unlocked position and the locked position by rotation of the operating lever, and moves the movable frame upward via the connecting link when moving from the unlocked position to the locked position,
A current detector comprising a lock lever that holds the movable frame in a locked state by engaging the locking pin with an engaging protrusion provided at the tip.