JP3295658B2 - System monitoring equipment for overhead distribution lines - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an overhead distribution line system monitoring device, and more particularly to an overhead distribution line system monitoring device used for searching for a recoverable ground fault (micro ground fault) in an overhead distribution line. About.

[0002]

2. Description of the Related Art Conventionally, in an overhead distribution line, it has been essential to search for a recoverable ground fault (micro ground fault) point that will result in a successful retransmission power transmission. Is used. A conventional overhead distribution line system monitoring device is configured by incorporating a zero-phase current sensor and a zero-phase voltage sensor in a switch or the like. Since it is built into devices such as switches, there is no degree of freedom in installation, and it is always connected to a fixed position in the distribution system.

[0003]

However, according to the conventional overhead distribution line system monitoring device, since the zero-phase current sensor and the zero-phase voltage sensor are built in the switch, the switch is installed inside the switch. It is necessary to maintain the insulation performance during the period. For this reason, it is necessary to arrange the sensor so as not to contact the mechanical part of the switch and the like, and it is inevitable that the shape becomes larger than the function. For this reason, the manufacturing process is complicated as compared with a normal switch, and the cost is increased. Moreover, since the shape and weight of the switch are large, a large-scale operation using a heavy machine such as a crane is required for installation.

In detecting a ground fault in such a device, a phase voltage output (PD output) and a phase current output (C
(T output), line information, especially the zero-sequence voltage value is easily affected by the weather and the like, and it is difficult to detect a micro-ground fault that is detected in a range in which the sensor output is very small. Furthermore, there are individual devices having a phase current measurement function that is effective for system operation analysis and a ground fault detection function that is effective for system fault investigation, but there is no device that has both functions.

Accordingly, an object of the present invention is to provide a system monitoring apparatus for an overhead distribution line which can be configured without being built in other equipment and which can search for a recoverable ground fault at any place in a short time by saving labor. To provide.

[0006]

Means for Solving the Problems In order to achieve the above object, the present invention provides a sensor unit mounted on a three-phase overhead distribution line for detecting a phase voltage and a phase current, and each of the sensor units from the sensor unit. A zero-phase voltage and a zero-phase current are generated based on the phase voltage and the phase current of a phase, and when a value of the zero-phase voltage and the zero-phase current exceeds a predetermined determination value, a ground fault occurs. Detecting means for determining the presence or absence, and further determining the direction of occurrence of a ground fault based on the phase difference between the zero-phase voltage and the zero-phase current; input means for setting the determination value; When the detection means determines a ground fault, a direction in which the ground fault occurs, a display unit that displays the values of the zero-phase voltage and the zero-phase current, and a direction in which the ground fault occurs, the zero-phase voltage and A fictitious device comprising storage means for storing the value of the zero-phase current and various data In the system monitoring device for distribution line, before
The overhead distribution line having an inner diameter corresponding to the outer diameter of the overhead distribution line.
A conductive spacer attached to the outer periphery of the wire;
The space having an inner end corresponding to the outer diameter of the empty distribution line
A cable attached from both ends of the
It includes a sensor portion constituted by a pair terminal cover, front
The sensor section is located at the center of the spacer of the sensor mounting section.
To detect the phase voltage and the phase current
Providing overhead distribution lines for system monitoring apparatus characterized by.

According to this configuration, the sensor unit detects the phase voltage.
And a phase current detection function.
The accuracy of phase voltage measurement can be improved by
In addition, the change of the earth capacitance of the phase voltage detector
Can be protected from the effects of

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a system monitoring apparatus for overhead distribution lines according to the present invention. An overhead distribution line system monitoring device according to the present invention includes a sensor unit 10 and a main unit 1 configured to be portable.
00. The sensor unit 10 includes a PCT sensor 11,
12 and 13 are provided. This PCT sensor 1
1, 12 and 13 are each provided with a phase voltage detector (PD) and a phase current detector (CT), and have three-phase overhead distribution lines R,
It is attached to each of the S and T lines. PCT sensor 11, 1
The CT output signals 11a (R-phase current I _R ), 12a (S-phase current I _S ), 13a (T-phase current I _T ) and the PD signals 11b (R-phase voltage V _R ), 12b
(S-phase voltage V _S ) and 13b (T-phase voltage V _T ) are detected, and the input terminals 102 and 10 of the overhead distribution line system monitoring device are detected.
1 is input.

The main body 100 includes an input terminal 101, an input terminal 102, an R-phase voltage V _R input to the input terminal 101,
S-phase voltage V _S transformer 1, and T-phase voltage V _T is input
03, a phase current detection unit 104 to which the R-phase current I _R , the S-phase current I _S , and the T-phase current I _T input to the input terminal 102 are input, and the output voltage of the transformer 103 (zero-phase voltage V ₀ ) And a ground fault detector 105 for detecting a ground fault (accident detection) based on the output (zero-phase current I ₀ ) of the phase current detector 104, the phase current detector 104, and the ground fault detector 105. Display / operation unit 106, PC card control unit 107 connected to ground fault detection unit 105, PC card control unit 10
7 and PC Card (PC Card)
PC card slot 108 in which PC 14 is mounted, main unit 1
The power supply unit 109 includes a power supply unit 109 for supplying DC power to each circuit in the power supply unit 00, and a ground terminal 110 for grounding a housing (not shown) of the main body unit 100 to the ground. Where PC
The card 14 is a PCMCIA (Personal Computer Me
mory Card This is a card-size storage medium that conforms to the International Association) standard. Ground fault detection unit 10
5 displays and sets accident detection (ground fault) information by exchanging data with the display / operation unit 106. The phase current detection unit 104 displays and operates the display / operation unit 106 and the PC card. By transmitting and receiving data to and from the control unit 107, setting and recording of accident detection are performed.

The display / operation unit 106 includes an accident direction display 106a for displaying the direction of the ground fault, a first LED 106b having a dot matrix display function for displaying measured values and the like, the set values and the like. The second LED 106c that performs display other than the above, various operations (display mode switching,
Operation switch 10 for performing an instruction to start measurement)
6d, is provided with a setting switch 106e for inputting the setting of the judgment reference value. LED 106b, 10
6c is driven by the display signal 105b of the ground fault detection unit 105, and the output signal (operation signal) 106f of the operation switch 106d is input to the ground fault detection unit 105,
Output signal (setting signal) 106 of setting switch 106e
g is input to the phase current detection unit 104.

The phase current detector 104 outputs the zero-phase current I ₀ as an output signal 104a,
Data 104b (setting data, phase current data) is output to PC card controller 107, and data 104c (setting data, phase current data, and accident data) and forced reset signal 104d are output to PC card control unit 107. Data 105a (accident data, various data) is output from the ground fault detecting unit 105 to the phase current detecting unit 104, and the LEDs 106b, 106
The display signal 105b is output to c.

The overhead distribution line system monitoring apparatus of the present invention is not a facility that is always installed at the site, but is a portable type having an independent configuration without being built in other equipment, in consideration of suppressing capital investment. I have. Then, in order to improve the accuracy of phase voltage measurement, it is installed via rubber spacers corresponding to the types and sizes of various overhead distribution lines. Terminal covers to protect against the effects of
2 and 13. This configuration will be described below.

FIG. 2 shows a state in which a PCT sensor is attached to one line of a three-phase overhead distribution line for measurement. A spacer 21 having a two-part structure is covered so as to sandwich the overhead distribution line R, and is fixed with vinyl tape. Spacer 2
For example, a conductive CR rubber is used as the material of (1).
The outer surface of the center of the spacer 21 has a PCT sensor 11
Is attached. Further, terminal covers 22 made of, for example, an epoxy resin are externally fitted to both ends of the spacer 21 and predetermined portions of the overhead distribution line R. 23 is a PCT sensor 11 for connecting to the input terminals 101 and 102.
Output lead from

FIG. 3 shows a detailed structure of the spacer 21.
(A) is a front view, (b) is XX sectional drawing. The spacer 21 is composed of a first spacer 21A and a second spacer 21B (not shown) which are divided into two parts in the radial direction from the center. When the electric wires are sandwiched in a state where they are opposed to each other, one spacer is formed. It becomes a cylindrical body. Here, only the spacer 21A will be described. The spacer 21A has a sensor mounting portion 21a on which the PCT sensor is mounted, and a cover mounting portion 21 formed on both sides thereof and having a larger diameter than the sensor mounting portion 21a.
b, 21c. A plurality of spacers 21 having different inner diameters are prepared according to the outer diameter of the overhead distribution line to be mounted.

FIG. 4 shows the detailed structure of the terminal cover 22.
(A) is a front view, (b) is a cross-sectional view, (c) is a side view at the time of attachment, and (d) is a side view at the time of attachment. Terminal cover 2
Reference numeral 2 denotes a cylindrical portion 22a, a tapered portion 22b formed at one end of the cylindrical portion 22a so as to gradually taper, and a ring-shaped cutting position index 22c formed at a plurality of locations on the outer surface of the tapered portion 22b. Have. The terminal cover 22
It is machined so that its inner diameter becomes smaller in order of d1, d2, d3 and d4. A cutting position indicator 22c is provided on an extension of the three step portions formed between each other. In the vicinity of each cutting position index 22c, a numerical value (not shown) indicating the approximate value of the inner diameter is engraved. Inner diameter d1 to d4
Is set to a value slightly larger than the applicable wire diameter so that it can correspond to various outer diameters of the overhead distribution line to be mounted. Also,
The terminal cover 22 is provided with a slit 22d in an axial direction so that the terminal cover 22 can be attached without cutting the overhead distribution line,
As shown in (d), it can be spread in the circumferential direction. Therefore, the terminal cover 22 is applied to the overhead distribution line while the cylindrical portion 22a is expanded, and if the terminal cover 22 is pushed in firmly, the entire terminal cover 22 can be easily fitted to the overhead distribution line and the spacer 21. Further, the cylindrical portion 22
Near the opening end of a, a sealant application portion 22e having an inner diameter slightly larger than d1 is provided. After applying the sealant to the inner surface, the sealant
In the cover mounting portion 21c.

FIGS. 5 and 6 show a procedure for mounting a PCT sensor on an overhead distribution line. The measurement method and operation of the system monitoring device of the present invention will be described below with reference to FIGS. First, the PCT sensor 1 brought to the site (measurement position)
1, 12 and 13 are mounted on desired positions of the overhead distribution lines (R, S, T). The procedure of this mounting will be described. First, as shown in FIG. 5A, the spacer 21A and the second spacer 21B are mounted on the overhead distribution line 51 from above and below the overhead distribution line 51 at the measurement position. Fit. In this state, as shown in FIG. 5B, the vinyl tape 52 is wound and fixed by half wrap.

Next, the two terminal covers 22-1 and 22
2 is prepared, and as shown in FIG. 5C, the cutting position index 22 on which a value close to the outer diameter of the overhead distribution line 51 is engraved.
Cut from position c. Next, as shown in FIG. 6A, two terminal covers 22-1 and 22-2 from which unnecessary portions have been removed are removed.
2-2 Inner surface of sealant application portion 22e and tapered portion 22
Apply a sealant to the inner surface at the end of b. Next, the sealing agent application section 22e is attached to the overhead distribution line 51 such that the sealing agent application section 22e comes to the end of the cylindrical section 22a around which the vinyl tape 52 is wound. Thereby, both ends of the terminal covers 22-1 and 22-2 are brought into close contact with the overhead distribution line 51 and the vinyl tape 52 surface. Further, as shown in FIG. 6A, the entire terminal covers 22-1 and 22-2 and the vinyl tape 52 are provided.
The vinyl tape 60 is wound by half wrap so as to cover a part of the slit, the slit 22d is closed to improve the insulating property, and the communication between the end and the slit 22d and the measuring unit is shielded from the atmosphere.

An overhead distribution line as shown in FIGS.
PCT sensors 11, 12, attached to R, S, T
13 are input terminals 101 of the main body 100,
102 is connected. Output from PCT sensors 11-13
Phase current I_R, I_S, I _TThrough the input terminal 102
Input to the phase current detector 104, and the three-phase voltage
V_R, V_S, V_TThrough the input terminal 101 and the transformer 103
Is input to the ground fault detection unit 105. Phase current I_R,
I_S, I_T, Zero-phase current I₀, Zero-phase voltage V₀Etc. is real
Measured and displayed in time.

When a ground fault occurs in the charged state, the three-phase voltages V _R , V _S , and V _T detected by the PCT sensors 11 to 13 are combined by the transformer 103 so that the zero-phase voltage V ₀ is obtained. The phase currents I _R , I _S , and I _T are generated by the phase current detector 104 to generate a zero-phase current I ₀ . The zero-phase voltage V ₀ and the zero-phase current I ₀ are compared with a judgment reference level (set value) preset in the phase current detection unit 104 and the ground fault detection unit 105. The phase current detection unit 104 and the ground fault detection unit 105 determine the zero-phase voltage V ₀ and the zero-phase current I ₀
When a ground fault occurs, the zero-phase voltage V ₀ and the zero-phase current I ₀ increase and exceed a determination reference level, and it is determined that a ground fault has occurred. At the same time, from the phase difference between the zero-phase voltage V ₀ and the zero-phase current I ₀ at that time, the direction of the fault point whether the ground fault point is on the power supply side or the load side is determined, and the fault direction display 106a The direction of the accident is displayed at The ground fault detection level is variable by the setting switch 106e, and it is possible to detect a range from a micro ground fault where the relay of the substation does not operate to a relay operation. The detection conditions can be selected by the following settings. (I) No power failure: Displays all detection results regardless of the presence or absence of a power failure. (Ii) Power outage: Displayed only when there is a power outage.

The setting data, phase current data, accident data (ground fault direction, phase, etc.), time, and each phase current value at every hour are stored in the PC card slot 108 when the PC card 14 is inserted. PC via card control unit 107
The data is automatically transferred to the card 14 and automatically stored in the PC card 14. The PC card 14 is a general-purpose product used in notebook personal computers and the like, and can be obtained at low cost. Since the PC card 14 has a cash card size, the size of the apparatus can be reduced, and a storage medium can be secured at low cost. In addition, since a plurality of sheets are not bulky even if they are possessed, it is possible to easily exchange them for each measurement place. If the input / output processing format is shared with a personal computer or the like, it is possible to use a personal computer or the like to execute database creation and analysis processing.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present inventors conducted operation verification in an actual field using the overhead distribution line system monitoring device having the configuration shown in FIG. FIG. 7 shows an operation verification result in a real field. In the setting of the ground fault detection, the detection levels were all set to the highest sensitivity, and the detection condition was set to “no power failure”. As is clear from FIG. 7, the measurement of each phase current was measured and recorded at all points, and it was confirmed that the operation was reliable. In the ground fault detection, a micro-ground fault (no relay operation of distribution = no power failure) on the distribution line only three times at branch B and T offices, and one unsuccessful retransmission accident occurred on another distribution line in the same bank Times detected. The details of * 1 to * 4 in the figure are
It is as follows. * 1 Successful retransmission accident with unknown cause. Installed to identify accident section. ※ V ₀ generated by the 2 substations. Installed near each rising pole to identify power distribution. However, since one circuit is an underground system,
Installed on distribution lines. * 3 Section current measurement for system switching. * 4 Phase current measurement at each point in the system to improve terminal voltage imbalance. After the measurement, the connection switching work of the single-phase transformer was implemented.

FIG. 8 shows an example of ground fault accident detection data.
FIG. 9 shows a schematic system and detection results of a T line in the B branch T office shown in FIG. In the figure, PDS means a system monitoring device. In the detection result on February 15 shown in FIG. 9A, the sections are determined so as to sandwich the private demand equipment A. As a result of conducting a DC withstand voltage test of the extension cable of this demand equipment, it was determined that caution was required in two phases.
It is expected that a fine ground fault in the cable was detected. The detection results on February 19 shown in FIG. 9B were all determined to be on the load side both times. Later, a contact from the chief engineer of the private demand equipment revealed that the GR relay had been activated at the same time as the detection time. The cause was a ground fault due to a rare short in the extension three-phase transformer, and the device detected these two ground faults. All the detection results on March 9 shown in FIG. 9C were determined to be on the power supply side. This is a detection of a ground fault accident at the interconnection switch of another distribution line in the same bank.

From the above results, No. 1 in FIG. 1 to No.
It can be confirmed that all the directions of the direction display of the device of No. 4 were performed without contradiction, it was confirmed that this device operates well in the actual field, and it is effective for detecting the ground fault section and measuring each phase current. It was confirmed that there was.

Further, a rubber spacer according to the type and size of the overhead distribution line and a terminal cover for protecting a change in capacitance to ground of a phase voltage detection (PD) portion from the influence of weather, moisture, etc. are provided by PCT sensors 11 to 11. 13 and the main body 10
By performing the residual canceling process at 0, the ground fault detection setting value becomes zero-phase voltage V ₀ = 100 V and zero-phase current I
₀ = 100 mA high-sensitivity detection is possible, and a micro-ground fault accident can be determined.

The ground fault detection is to detect the direction of a defective section when a ground fault phenomenon occurs due to a charged state. Therefore, when trying to identify a defective section of a successful retransmission accident, a system monitoring device is installed after the occurrence of the accident, and the accident section is detected when the next ground fault occurs.

In the above embodiment, a PC card is used as a storage medium. However, the present invention is not limited to a PC card.
It is also possible to use a memory card for a digital camera.

In the above embodiment, the spacer 21
Although a conductive CR rubber was used for the present invention, the present invention is not limited to this, and any material having conductivity, adhesion, flexibility, and weather resistance may be used. Similarly, the terminal cover 22 is not limited to the epoxy resin, and is not particularly limited as long as it has similar characteristics and properties.

[0028]

As described above, according to the overhead distribution line system monitoring apparatus of the present invention, the overhead distribution line external diameter can be adjusted.
Attached to the outer circumference of the overhead distribution line
Conductive spacers, and according to the outer diameter of the overhead distribution line.
The fictitious distribution from both ends of the spacer having an inner diameter end
With a pair of terminal covers attached to the wires
A sensor unit, wherein the sensor unit is
Attached to the center of the spacer of the
Since the phase voltage and the phase current are detected, the phase voltage
The accuracy of measurement can be improved, and the electrostatic
Capacity changes can be protected from the effects of weather, humidity, etc.
I can .

[0029]

[0030]

[Brief description of the drawings]

FIG. 1 is a block diagram showing an overhead distribution line system monitoring apparatus according to the present invention.

FIG. 2 PCT on one of three-phase overhead distribution lines for measurement
It is a front view showing the state where a sensor was attached.

3A and 3B show a detailed configuration of the spacer of FIG. 2, wherein FIG. 3A is a front view and FIG. 3B is a sectional view taken along line XX.

4A and 4B show a detailed configuration of the terminal cover of FIG. 2, wherein FIG. 4A is a front view, FIG. 4B is a cross-sectional view, FIG.
(D) is a side view at the time of mounting.

FIG. 5 is an explanatory diagram showing a procedure for mounting a PCT sensor on an overhead distribution line.

FIG. 6 is an explanatory diagram showing a procedure following FIG. 5;

FIG. 7 is an explanatory diagram showing an operation verification result in a real field of the overhead distribution line system monitoring apparatus of the present invention.

FIG. 8 is an explanatory diagram showing an example of ground fault detection data in the overhead distribution line system monitoring apparatus of the present invention.

9 is a system diagram showing a schematic system of a T line shown in FIG. 7 and a detection result.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Sensor part 11, 12, 13 PCT sensor 14 PC card 21 Spacer 22, 21A, 21B Terminal cover 21a Sensor mounting part 21b, 21c Cover mounting part 22a Cylindrical part 22b Tapered part 22c Cutting position index 22d Slit 51 Overhead power distribution line 100 Main body Unit 101, 102 Input terminal 103 Transformer 104 Phase current detection unit 105 Ground fault detection unit 106 Display / operation unit 106a Fault direction display display 106b, 106c LED 106d Operation switch 106e Setting switch 107 PC card control unit 108 PC card slot

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-144717 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H02H 3/38

Claims (4)

(57) [Claims] 1. A sensor unit mounted on a three-phase overhead distribution line and detecting a phase voltage and a phase current, and a zero-phase voltage and a zero-phase voltage based on the phase voltage and the phase current of each phase from the sensor unit. A zero-sequence current is generated, and it is determined whether or not a ground fault has occurred when the values of the zero-sequence voltage and the zero-sequence current exceed a predetermined determination value, and the zero-sequence voltage and the zero-sequence current are further determined. Detecting means for determining the direction of occurrence of a ground fault, based on the phase difference between the input means for setting the determination value, and when the detecting means determines a ground fault, A display unit for displaying the direction of occurrence, the values of the zero-phase voltage and the zero-phase current, and storage means for storing the direction of occurrence of the ground fault, the values of the zero-phase voltage and the zero-phase current, and various data. in the system monitoring device for overhead distribution lines comprising, before
The overhead distribution line having an inner diameter corresponding to the outer diameter of the overhead distribution line.
A conductive spacer attached to the outer periphery of the wire;
The space having an inner end corresponding to the outer diameter of the empty distribution line
A cable attached from both ends of the
A sensor portion configured by a pair of terminal covers, wherein the sensor portion is provided in the spacer of the sensor mounting portion.
Attached to the center to detect the phase voltage and the phase current
A system monitoring device for overhead distribution lines. 2. The spacer is processed by using an elastic member.
And divided into two parts so that they can be attached to the overhead distribution line from both sides.
The system monitoring device for overhead distribution lines according to claim 1, wherein: 3. The terminal cover is externally fitted to the spacer.
A cylindrical portion to be formed, and formed integrally with the cylindrical portion,
Tapered portion externally fitted to the overhead distribution line to provide the termination
Through the cylindrical portion and the tapered portion for the entire length.
The overhead distribution line system monitoring device according to claim 1, further comprising a single slit provided . 4. The tapered portion is provided with a plurality of types of overhead distribution lines.
Multiple inner diameter parts corresponding to the outer diameter are provided stepwise
The overhead distribution line system monitoring device according to claim 3, wherein: