JPS628069A - Failure orientation system - Google Patents

Abstract

PURPOSE:To facilitate the orientation of a failure, such as a ground fault or the like, by measuring the current and voltage of each phase line of a three- phase transmission cable to obtain an electric power per line and orienting the failure on the basis of the polarity of the power when a current value exceeds a normal one. CONSTITUTION:Each phase line U, V or W of a three-phase transmission cable is provided with a current detector 51 and a voltage detector 52, with which a wattmeter 53, comparators 54a and 54b, a comparator 55, a trigger generator 56, a timer 57 and a recorder 58 are connected. The current and voltage of the phase line U, V or W are measured by the current and voltage detectors 51 and 52 and inputted to the comparators 54a and 54b, respectively, via the wattmeter 53. When the value of current per line is positive, the comparator 54b is operated, when negative, the comparator 54a is operated, and when largely exceeds a value in a normal operation, the comparator 55 operates the trigger generator 56 to record the orientation of a failure, a data and the like on the recorder 58. Thus, only by providing one failure orientation instrument in a branch, the orientation of the failure, such as a ground fault or the like, can be facilitated.

Description

[Detailed description of the invention] [Subject of invention] The present invention relates to a method for locating the direction of a fault in a power system.

[Prior art] In recent years, electric power systems have become longer, cabled, and have multiple terminals as demand expands over wider areas. It is desired to develop a highly accurate failure point locating device that can be applied to

Conventionally used fault point locating devices include the pulse radar method, which applies an impulse from the system terminal and measures the time it takes for it to reflect at the fault point and return, or the pulse radar method, which uses pulse waves generated at the fault point. There are surge reception methods that take measurements at electrical stations at both ends of the system and locate the fault point based on the time difference, both of which use traveling wave phenomena to measure and locate time.

However, with the above method, the propagation speed of the pulse is fast, the applied pulse or accidental surge is subject to attenuation and distortion as it progresses, it is subject to reflection at the suspension section or branch point of the system, and there are concerns that it may be confused with lightning. With the current complex system, there is clearly a limit to performance improvement.

An idea to improve this is to measure the current flowing through the overhead ground wire of the overhead power transmission line at multiple locations, and transmit the current value or current phase information at each location to the terminal electrical station, etc. to locate the faulty section. A method has been proposed, but it has the drawback of increasing equipment costs because it requires a long information transmission line and a large number of devices.

[Object of the Invention] The present invention improves the drawbacks of the prior art described above, and
In a power system with many system branches and multiple power sources, by installing the fault direction locating device disclosed in this method at at most one location in the branch that makes up the system, it is possible to prevent both ground faults and short circuits. The purpose of this invention is to provide a new method that can locate the direction of failure.

[I of invention! In other words, measure the current and voltage of each of the three phases, calculate the power per line from these, and if the current value significantly exceeds the normal current value, locate and record the fault direction based on the sign of the power. It is configured to do this.

[Supplementary explanation of the invention] The principle of the present invention will be explained with reference to FIG.

Figure 1 is a model of a single-line power transmission system with a power source and a load at both ends. ffi source (Eu,
Ev, Ew)2. Equivalent impedance of load and power source 3. and ground impedance 4.

The sections on both sides of one arbitrary point on the power transmission line 1 are defined as a section B and a section B. The voltage of each phase (Vu, Vv
, Vw) and current (IU, IV, 1w) to find the power, and when the power flows in the direction of 8 sections when viewed from one point, the power is determined to be positive. At this time, the power P per line is calculated using formula (1)% formula% When a short circuit or ground fault occurs on power transmission line 1, a large current flows to the fault point, and the power determined at one point is greater than the absolute value under normal load. The value becomes significantly large. For example, the failure point is 8
If it is the section (point Fe), the direction is to supply power to section B when viewed from one point, so the power is positive. On the other hand, if the failure point is in section F (point F^), the supply direction is opposite and the power is negative.

That is, the fault direction can be determined as shown in (2) based on the positive or negative value of the power P determined at one point.

[Example] An embodiment of the present invention will be described with reference to FIG.

FIG. 2 is a block diagram showing an embodiment of the fault direction locating device 5 based on this method, in which a current detector 51, a voltage detector 52. Power meter 53. Comparators 54a, 54b
,]l:/valley955. to! J gas generator 56.
Timer 57. It is composed of a recorder 58.

The current and voltage of each phase of the power transmission line U, V, and W are measured by a current detector 51 and a voltage detector 52, respectively, and a wattmeter 5
3 is input. The output P of the wattmeter 53 is the comparator 5
When P is positive, the comparator 54b operates, and when P is negative, the comparator 54a operates. The outputs of these comparators 54a and 54b are input to a recorder 58.

On the other hand, the output of each phase of the current detector 51 is also input to a comparator 55, and when a current significantly higher than a normal state is measured, the comparator 55 operates a trigger generator 56 to output a trigger signal.

This signal causes the recorder 58 to move to the comparator 54.
The failure direction, date, hour, minute, second, etc. are recorded as the output of a or the comparator 54b and the output of the timer 57.

In the above configuration, the current detector 51 and the voltage detector 5
2 uses an optical element such as YIG that uses the Faraday effect and a BGO that uses the electro-optic effect in addition to using the usual C-King.
You may use optical elements such as. In this case, an optical fiber code is used as the transmission path. By configuring the detection unit with only an optical system, highly reliable positioning is possible without being affected by lightning or the like. Further, as a means for protecting the creeping surface of the optical fiber cord, it is desirable to insert the optical fiber cord into an insulator tube and fill it with SFs gas, N2 gas, etc., which have excellent withstand voltage characteristics.

FIG. 3 shows an example in which a fault direction locating device 5 is installed on a power transmission line 1 having power sources 2 at both ends. The fault direction locating device 5 is
It is set so that it becomes positive when power flows from section C to section D.

For example, if a failure occurs at point F in section C, the power flowing through the detection section of the failure direction locating device 5 (the location where the current detector 51 and voltage detector 52 are installed) will flow from section D to section C. Therefore, the power is observed as a negative value, and the recorder 58 in the failure direction locating device 5 records that the failure occurred in section C.

FIG. 4 shows an example in which a fault direction locating device 5 is installed on a power transmission line where a system branch exists. Branch, M.

One current detector 51 is installed at each branch station, and a voltage detector 52 is installed at each branch station. Since the voltages are at the same potential at the branch point O, there is no need to install a voltage detector 52 for each branch. At the branch point O, there is a fault direction locating device 5 which includes a current detector 51 and a voltage detector 52.
is installed, a current detector 51 and a voltage detector 52
and is connected by a transmission line (omitted in the figure). In addition, the power 2 branch M flowing from the L1 section to the 2 section is M1.
The power flowing from the section to the M2 section and the power flowing from the branch N from the N1 section to the N2 section are set to positive power.

For example, if a failure occurs at point F in the N1 section of branch N, the positive power for the branch is 9 branches M.

Since negative power is observed with respect to N, the recorder 58 of the failure direction locating device 5 records that the failure point exists in one of the L2 section, M1 section, and N1 section.

[Advantageous Effects of the Invention 1] Since the present invention is a method of locating the fault direction based on the positive and negative power flowing through the power transmission line, it is possible to locate the fault direction regardless of the type of ground fault or phase-to-phase short circuit fault. In addition, the number of devices is extremely small compared to the conventional case of installing each tower, and it is economical because a long transmission line is not required.

We believe that the essence of the present invention will be demonstrated to its fullest, especially when used in long and multi-branched power transmission systems or systems with a wide variety of installation methods.

[Brief explanation of drawings]

FIG. 1 is a power transmission system model diagram, FIG. 2 is a configuration block diagram of the present invention, and FIGS. 3 and 4 are explanatory diagrams showing one embodiment of the present invention. 1: Power transmission line, 2: Power supply, 5: Fault direction locating device, 51
: Current detector, 52: Voltage detector, 53 :? i force meter,
54a, 54b:: lumberrator, 55: comparator, 56: trigger generator, 58: recorder. Agent Patent Attorney Fujio Sato No. 1, No. 2, No. 3, No. 4 Written Amendment to Complaint Proceedings (Method) 60.10. . 4 Showa year month day 1 Indication of the incident 1985 Patent Application No. 147422 2 Name of the invention Fault direction locating method 3 Name of the person making the amendment (512) Representative of Hitachi Cable Co., Ltd.
Hiroharu Hashimoto 6, Subject of amendment (1) Plan of the drawings 7, Contents of amendment (1) As shown in the attached sheet. 8. List of attached documents (1) Attachment (drawings) At least 1 copy of the original document (spontaneous document) ao, io. 25 Showa 1960 Patent Application No. 147422
Name of invention No. 2 Direction mark, determination method 3
Representative of the person making the amendment: Hiroshi Hashimoto 4 Representative: io. Address: 2-1-2 Marunouchi, Chiyoda-ku, Tokyo @ Detailed explanation column of the subject invention to be amended Contents of the amendment (1) Page 4 of the specification (1) Formula % Formula % shall be corrected. (2) On page 6, line 9 of the specification, "electro-optics" is corrected to "Pockels."that's all

Claims (1)

[Claims] (1) In the method of locating the direction of a fault on a power transmission line, the power per line is determined from the current and voltage information obtained from the current and voltage detectors installed in each of the three phases, and the positive or negative of the power is determined. A failure direction locating method characterized by locating the failure method by