JPS6235335B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION When an abnormal current flows in a power line such as a distribution line due to a one-line ground fault, phase-to-phase short circuit, or other similar accident, the present invention displays the section where the accident occurred, and also displays the accident state. This invention relates to an abnormal current display device for a power line that can cancel the fault display and return to the normal display after a certain period of time has elapsed after the problem is resolved and power is transmitted again.

In this abnormal current display device, it is necessary to reliably detect an abnormal current and to secure driving power for displaying an accident and, in particular, for recovering from its release. Attempts have been made to avoid obtaining this driving power from a separate power source independent from the power line, and to obtain it from the power line itself via a transformer and, if necessary, a transformer connected thereto.

Although this attempt simplifies the configuration of the device,
Since an abnormally large current during an accident flows from one transformer to another in the same way as a steady current during normal conditions, an abnormally large voltage or a peak voltage with significant waveform distortion is applied to the device as an excessive voltage. Therefore, it is necessary to design a design to suppress the generation of excessive voltage, but in this case, the capacity of the equipment used becomes unreasonably large.On the other hand, if the capacity is determined according to the current value under normal conditions, A problem arises in that excessive voltage during an accident threatens the electrical insulation of various parts of the device.

The purpose of the present invention is to eliminate the above-mentioned defects and to use two transformers: a detection current transformer that detects abnormal current that occurs in the power line in the event of an accident, and a recovery current transformer that uses the steady current of the power line. By this,
An object of the present invention is to provide an abnormal current display device for a power line that can reduce the capacity of equipment used and improve the electrical insulation of each component.

Hereinafter, a first embodiment embodying the present invention will be explained with reference to FIGS. 1 to 5. As shown in FIG. 1, this abnormal current display device detects an abnormal current generated in a power line L. a detection unit A, a display drive unit B configured to perform a display operation using the abnormal current detected by the detection unit A, and a recovery power supply unit H for introducing the steady current of the power line L;
The return drive unit I is operated by the steady current of the power supply unit H, and the display drive unit B performs display operation, and the return drive unit I releases and returns the display state to the steady state. It is composed of a display device J.

First, the abnormal current detection section A will be explained. This detection section consists of a detection current transformer 2 which has a coil wound around a cut core-shaped iron core 1 made of a magnetic material.
and a step-up transformer 3 connected to the output side of the transformer 2.
(may be omitted). The magnetization characteristics of the iron core 1 made of the magnetic material are shown in Figure 2a.
As shown in , it has a small magnetic permeability in a small magnetomotive force region where the relative value is 1 or less, and it has a large magnetic permeability in a large magnetomotive force region where the relative value is greater than 1. The shape, dimensions, and windings of the iron core 1 are determined so that a de facto output is obtained in the transformer 2 only when the relative value of the magnetomotive force due to the abnormal current becomes larger than 1 and a fault current flows. It is being

The display drive unit B includes a full-wave rectifier 4 connected to the transformer 3, and a charging resistor R on the DC side of the rectifier.
1 and a bidirectional trigger diode TD1 connected to the same capacitor C1.
, a drive coil 40a, and a discharge resistor R4 connected in parallel to the capacitor C1. When the terminal voltage of the capacitor C1 reaches a certain value, the trigger diode TD
1 becomes conductive so that the charge in the capacitor C1 is discharged by the drive coil 40a. Further, the value of the discharging resistor R4 is set to be sufficiently larger than the value of the charging resistor R1, and when the DC voltage of the rectifier 4 is maintained, the capacitor C1 is connected to the charging resistor R1.
After the DC voltage has significantly decreased or disappeared, the charge of the capacitor C1 is discharged by the discharge resistor R4 within an appropriate time.

The recovery power supply unit H includes a recovery current transformer 6 in which a coil is wound around a cut core-shaped iron core 5 made of a magnetic material, a surge absorber 7 connected in parallel to the output side of the transformer, and a surge absorber 7 thrust in the opposite direction. A pair of matched Zener diodes ZD1, ZD2
and a dummy resistor R3 connected to the output side of the transformer 6 via a changeover switch 8, which will be described later. In this embodiment, the surge absorber 7, Zener diodes ZD1, ZD2, and dummy resistor R3 are Overvoltage absorption circuit Ha
It is called. The iron core 5 itself made of the magnetic material is
As shown in Figure b, the shape, size, and winding of the iron core 5 are determined so that it has normal magnetization characteristics and the value of relative magnetomotive force due to steady state current is in a region smaller than 1. .

The return drive section I is composed of a synchronous motor SM and a changeover switch 8, and a movable contact 9 of the switch 8.
is in contact with the fixed contact 10a, the dummy resistor R3 is in contact with the fixed contact 10a, and the movable contact 9 is in contact with the fixed contact 10a.
When switched to b, each of the synchronous motors SM is connected to a transformer 6.

Next, to explain the display device J, a gear 11 is fixed to the rotating shaft of the synchronous motor SM, and one end of the rotating shaft 12 is supported in a fixed position so as to be parallel to the rotational axis of the gear. As shown in FIG. 3, a circular display board 13 is fixed on the surface of the
A fan-shaped accident display section 13a and a normal state display section 13b having a central angle of 90 degrees are alternately formed into sections. Then, the accident display section 13a turns red, for example.
The normal state display portions 13b are each colored green, and the accident state can be notified by the difference in color according to custom. a display case 14 arranged at a fixed position to rotatably house the display board 13;
As shown in FIG. 4a, a fan-shaped window 14a having a central angle of 90 degrees is formed on the surface.

A pair of clutch gears 17 and 18 fixed to both ends of the interlocking shaft 16 are engaged with the reduction gear 15 fixed on the rotating shaft 12 and the gear 11, respectively, and are engaged with the interlocking shaft 16 and the fixed position 19. Clutch gears 17 and 18 are urged to mesh with gears 11 and 15 by a tension spring 20 provided therein. These series of interlocking shafts 16, clutch gears 17, 18
The gears 11, 15, etc. are connected to the display plate 13 by a means (not shown) that allows rotation only in one direction.
is supported so that it can rotate only in the direction in which it returns to its normal state. A movable piece 21 made of a magnetic material is fixed to the center of the interlocking shaft 16, and the movable piece 21 is fixed to the center of the interlocking shaft 16.
When the movable piece 21 is excited, the drive coil 40
The clutch gears 17 and 18 are moved away from the gears 11 and 15 by being attracted to the a side.

A spring 22 for displaying the display panel 13 is wound around the rotating shaft 12, and one end of the spring 22 is fixed to the rotating shaft 12, and the other end is fixed to the fixed position. Then, when the synchronous motor SM is rotated in the normal state return direction and the rotating shaft 12 is rotated in the same direction via the gear 11, clutch gears 17, 18, and gear 15, energy is stored.

The aforementioned gear 11, rotating shaft 12, and reduction gear 1
5. The interlocking shaft 16, clutch gears 17, 18, fixed position 19, tension spring 20, movable piece 21, etc. constitute a gear mechanism Ja as a delay mechanism for displaying the display panel 13. Further, the interlocking shaft 16, clutch gears 17, 18, and tension spring 2
0 and the movable piece 21 constitute a clutch mechanism Jb that connects and disconnects the power of the gear mechanism Ja.

Note that the reduction ratio of the gear 18 and the gear 15 is such that the synchronous motor SM continues to rotate for 3 hours, for example, and the gear 1
5 is set to a value that gradually rotates about 90 degrees.

An operating piece 23 is fixed to the back surface of the display plate 13 and projects through a circumferential groove 14b formed on the back surface of the display case 14, so that the changeover switch 8 is operated as the display plate 13 rotates. There is. That is, when the normal display section 13b of the display board 13 completely appears in the window 14a of the display case 14,
The movable contact 9 and the fixed contact 10a are closed, and when the accident display part 13a completely appears on the window 14a, the movable contact 9 and the fixed contact 10b are closed.

Next, the operation of the abnormal current display device configured as described above will be explained.

Now, as shown in FIG. 4a, when the normal display section 13b of the display board 13 is completely visible through the window 14a of the display case 14 and the energy storage spring 22 is in the state where the energy is stored to its maximum, an accident occurs on the power line L. When an abnormally large current i flows as shown by the solid line in FIG. 5, this large current i becomes a magnetomotive force and the output voltage e shown by the broken line in FIG. Occurs on the output side. Due to the significant nonlinearity of the magnetization characteristic a, the ratio of the output voltages e′ and e in normal and abnormal conditions is much larger than the corresponding ratio of steady current i′ to abnormal current i, and as a result, in abnormal conditions The large output voltage e is converted into direct current by the rectifier 4 and charges the capacitor C1.

When the voltage of the capacitor C1 reaches a predetermined value, the trigger diode TD1 becomes conductive, and the drive coil 40a is excited, which causes the movable piece 2
1 is attracted against the tension spring 20, and the clutch gears 17 and 18 are disengaged from the gear 11 and the reduction gear 15. As a result, the reduction gear 15 and the display board 13
rotates freely in the display direction due to the stored force of the storage spring 22, and as shown in FIG. 4b, the window 1 of the display case 14 opens.
The accident display section 13a of the display board 13 is completely exposed at 4a, and is held in that position by the elasticity of the energy storage spring 22. At the same time as this accident display operation is completed, actuating piece 2
3 connects the movable contact 9 of the changeover switch 8 to the fixed contact 10
a to 10b. In addition, in the state before switching, the commercial frequency component of the excessive voltage caused by the abnormal current is absorbed by the dummy resistor R3,
This prevents excessive voltage from being applied to the changeover switch 8. In addition, the peak voltage caused by the saturation of the iron core 5 is reduced by the Zener diodes ZD1 and ZD2.
Surge absorber 7 handles steep surges caused by accidents.
The electrical insulation of the changeover switch 8 and related parts is guaranteed.

Subsequently, when the switch or breaker installed in the power line L stops the abnormal current and the power line becomes temporarily powerless, the excitation of the drive coil 40a is released and the spring force of the tension spring 20 is reduced. Interlocking axis 1
6 has returned and clutch gears 17 and 18 are in gear 1.
1, are meshed with the reduction gear 15, respectively. In this state, when the power line L returns to the normal state again and a steady current begins to flow, the contacts 9 and 10, which have already been closed,
Power is supplied from the transformer 6 to the synchronous motor SM through b, and the rotation of this motor causes the display plate 13 to connect to the storage spring 21 via the gear 11, clutch gear 17, interlocking shaft 16, clutch gear 18, and reduction gear 15.
While accumulating energy, it gradually returns to its original position in the return direction. At this time, the display board 13 is in a positional relationship as shown in FIG. 4c, with the accident display section 13a and the normal state display section 13b.
The approximate elapsed time after power is retransmitted to the power line L can be determined by the position of the boundary line n.

After the power is retransmitted, when a certain period of time (approximately 3 hours) required for a patrol to investigate the cause of the accident has elapsed, the normal display section 13 will be turned on again as shown in Figure 4a.
b completely appears in the display window 14a. At the same time, the movable contact 9 is changed to the fixed contact 10b by the operating piece 23.
10a side, and the synchronous motor SM stops. The normal display state and the energy storage state of the energy storage spring 22 are maintained by a means (not shown) that allows the clutch gears 17, 18 to rotate only in the return direction.

If abnormal current flows again after the return operation is completed or during the return operation, the drive coil 40a operates in the same way and the accident display section 13a returns to the display window 1.
4a, after which the operations described above are repeated.

Now, in the first embodiment of the present invention, the transformer 2 having a magnetization characteristic that has a small magnetic permeability in a small magnetomotive force region and a large magnetic permeability in a large magnetomotive force region is used in the abnormality detection part A. It is possible to selectively and accurately detect only the abnormal current and to reliably display an accident. In addition, in the first embodiment of the present invention, the display drive unit B is constituted by the rectifier 4, the capacitor C1, the trigger diode TD1, and the drive coil 40a, so when the capacitor C1 is charged to a constant voltage, the trigger diode TD1 is turned on. The drive coil 40a is excited, so the movable piece 22 can always be operated with a constant driving force, improving its reliability.

In addition, in the first embodiment of the present invention, the recovery power supply section H is constituted by the recovery transformer 6, the surge absorber 7, the Zener diodes ZD1, ZD2, and the dummy resistor R3. This has the advantage that the upper limit of the voltage actually applied to the device can be maintained at a constant value to protect the equipment, and that it can also contribute to maintaining insulation reliability and recovery power. Furthermore, since the recovery power supply section H supplies power from the normal power line L to the recovery drive section I to gradually return the display device J to the normal display, the accident display is automatically displayed after a predetermined period of time has passed each time an abnormal current occurs. Can be canceled automatically.

Furthermore, in the first embodiment, since the return drive section I is constituted by the synchronous motor SM and the changeover switch 8, the return operation to the normal display is performed in proportion to the rotational speed of the synchronous motor, and therefore the return time is shortened. Settings can be made accurately and the synchronous motor
While the SM is rotating, the accident display section 13a of the display board 13
can be rotated gradually and continuously to effectively call attention to the accident display.

Next, second to fourth embodiments of the present invention will be described with reference to FIGS. 6 to 8, respectively. In addition,
In each of the following embodiments, members that are substantially the same as those in the first embodiment are designated by the same reference numerals, and explanations thereof will be omitted.

In the second embodiment shown in FIG. 6, a drive coil 40a is directly connected to the step-up transformer 3, and the drive coil 40a is excited by an abnormal alternating current to attract the movable piece 21. This is the same as the first embodiment. Therefore, this second embodiment:
Although the display drive unit B can have a very simple structure with only the drive coil 40a, other functions and
The effect is similar to that of the first embodiment.

In the third embodiment shown in FIG. 7, an intermediate gear 25 is meshed between the reduction gear 15 and the clutch gear 18,
A rotary display body 27 consisting of two disks 27a and 27b colored in red or the like that is easily noticeable is fixed to one end of the rotation shaft 26, and a transparent case 28 is placed outside the display body. Further, the actuating piece 23 is fixed around the reduction gear 15, and the other configurations are the same as in the first embodiment. Therefore, in this third embodiment, during the return operation period in which the synchronous motor SM is rotating, the rotating display body 27 is rotated at a speed that is easily followed by human vision, thereby calling attention to the accident display. However, other functions and effects are the same as those of the first embodiment.

In the fourth embodiment shown in FIG. 8, the display plate 13 is directly connected to the rotating shaft of the synchronous motor SM, and the operating piece 23 is fixed around the reduction gear 15, but the other configuration is the same as that of the first embodiment. This is similar to the example. Similar to the third embodiment, this fourth embodiment is also characterized in that it is easy to draw attention to the accident display.

As described in detail above, the present invention can reduce the capacity of the equipment used, improve the electrical insulation of each part, and furthermore, the present invention can maintain a constant temperature after an accident is displayed until a recovery indication is displayed. Since the display is displayed over a period of time, it is possible to know when the accident occurred by visually checking the display device during the recovery operation, which has an excellent effect of being useful in clarifying the accident.

[Brief explanation of the drawing]

1 to 5 show a first embodiment of the abnormal current display device of the present invention, and FIG. 1 is a circuit diagram showing the whole,
Figure 2 is a graph showing the magnetization characteristics of the transformer, Figure 3 is a front view of the display board only, Figure 4 a, b, and c are front views showing the display status of the display board, and Figure 5 is the transformer. 6 is a circuit diagram showing only the vicinity of the drive coil showing the second embodiment of the present invention, and FIG. 7 is a circuit diagram showing only the vicinity of the display board showing the third embodiment of the present invention. 8 is a front view of only the vicinity of a synchronous motor showing a fourth embodiment of the present invention. Transformers 2 and 6, display board 13, drive coil 40,
Display board 43, abnormal current detection section A, display drive section B,
A return power supply section H, a return drive section I, and a display device J.

Claims (1)

[Claims] 1. Abnormal current detection section A consisting of a detection current transformer 2, etc., which detects abnormal current generated in the power line during an accident.
A display drive unit B that drives a display based on the current detected by the abnormal current detection unit A; and a recovery power supply unit H that is provided on the power line and includes a recovery current transformer 6 that utilizes the steady current of the power line.
and a return drive section I driven by the return power supply section H.
and a display member 13 that is driven by the display drive unit B to display an accident display and displays the elapsed time from the time of displaying the accident when returning to normal display;
The display member 13 is driven by the return drive unit I.
1. An abnormal current display device for a power line, comprising: a display device J having a delay mechanism Ja for delaying recovery over a certain period of time from the time when an accident is indicated. 2 The detection current transformer 2 is formed of a magnetic material having a magnetization characteristic that has a small magnetic permeability in a small magnetomotive force region and a large magnetic permeability in a large magnetomotive force region, and is The power line abnormal current display device according to claim 1, wherein said power line abnormal current display device is made of a magnetic material having normal magnetization characteristics. 3 The abnormal current detection section A includes a detection current transformer 2,
An abnormal current display device for a power line according to claim 1 or 2, which comprises a transformer 3 connected to the transformer. 4. The power line abnormal current display device according to claim 1 or 2, wherein the recovery power supply unit H includes a recovery transformer 6 and an overvoltage absorption circuit Ha connected to the recovery transformer 6. 5. The power line abnormal current display device according to claim 1 or 2, wherein the display drive section B is constituted by a drive coil 40 connected to the abnormal current detection section A. 6 The display drive section B is configured by a rectifier 4 that rectifies the current from the abnormal current detection section A, a charging resistor R1 and a capacitor C1 connected to the rectifier 4, and a trigger diode TD1 and a drive coil 40 connected to the same capacitor. An abnormal current display device for a power line as set forth in claim 1, 2, or 3. 7 The return drive unit I is composed of a synchronous motor SM and a changeover switch 8, and when the display device J comes to the normal display position, the changeover switch 8 switches the dummy resistor R3 side to the dummy resistor R3 side, and the display device J to the accident display position. When the synchronous motor reaches the position, the synchronous motor is switched to the SM side, respectively.
Abnormal current display device for power lines as described in Section 1. 8 The display device J rotates the display board 13 held in the normal display position and the display board 13 that has been moved to the accident display position to the return position while being constantly biased in the accident display direction by the biasing member 22. A gear mechanism Ja as a delay mechanism is interposed between the display board 13 and the rotating shaft of the synchronous motor SM so as to be able to move, and a gear mechanism Ja as a delay mechanism is interposed in a part of the gear mechanism and is connected to the display drive section B. An abnormal current display device for a power line according to claim 1 or 7, comprising a clutch mechanism Jb which is thereby released.