JPS63221268A - Fault point location system for parallel stringing line installation system - Google Patents

Abstract

PURPOSE:To compensate the influence of an induced electromotive force and to perform high-accuracy location by inputting the current value of a parallel stringing line as well as the current value of a located line and performing location arithmetic operation including the mutual impedance between the located line and the parallel stringing line. CONSTITUTION:Terminal devices A1 and B1 are provided at an A terminal and a B terminal, voltage and current quantities of respective phases which are measured here are transmitted as data to a center device C, and the phase difference between the data from the terminals is used to locate a fault point position by a prescribed location arithmetic expression. here, the voltage and current measured values at the respective terminals of a power transmission system where the attended line is provided are gathered on one place to synchronize the respective measured values. Then voltage drops per unit time of the current measured value of the located line and the current measured value of the attended line are calculated and the fault point is located by a prescribed location arithmetic expression based upon those voltage drops, the voltage measured value of the located circuit, and the distance between the terminals, to compensate the influence of induced expression electromagnetic force generated by the mutual induction from the parallel stringing line.

Description

[Detailed description of the invention] [Technical field to which the invention pertains] In order to ensure the frequency of power supply, the present invention enables fault recovery by locating the location of a fault that has occurred in a power transmission line based on the voltage and current of each phase detected at both ends of the transmission line after an accident. This relates to a fault point locating method that aims to speed up the process, and in particular enables accurate location of power transmission systems where parallel overhead lines are installed by eliminating the effects of mutual induction from the parallel lines. be. [Prior art and its problems]

As shown in Figure 3, when a failure occurs in a system with two electrical stations A and B at both terminals, knowing the distance from A or B terminal to failure point F is the key to repairing the subsequent failure point. It is necessary and essential for work etc. For this purpose, terminal devices A1 and B1 are conventionally provided at the A terminal and B terminal, and the voltage and current amount of each phase measured by the terminal devices A1 and B1 is transmitted as data to the solid device C. In this method, a phase difference between data from each terminal is used to locate a fault point position using a predetermined location calculation formula. However, since the conventional location calculation formula uses data only from the location line, if there is a parallel line, an induced electromotive force is generated in the location line due to mutual induction from the side line, which affects the location calculation. There was a problem in that this could lead to errors.

[Purpose of the invention]

In view of the above, an object of the present invention is to provide a fault point locating method that can locate a fault point in a power transmission system in which a parallel overhead line exists with high accuracy by performing a location calculation that takes mutual guidance from the parallel overhead line into account. shall be.

[Key points of the invention]

The present invention measures the voltage and current of each terminal of a location line at each terminal device installed at each terminal of a power transmission system where a parallel line exists, and also measures the current of a parallel line in at least one of the terminal devices. Then, after collecting each voltage and current measurement value in one place and synchronizing each measurement value, the voltage drop per unit length due to the current measurement value of the location line and the current measurement value of the parallel line is calculated. By calculating the voltage drop, locating the fault point using a predetermined locating formula based on the voltage measurement value of the locating line, and the distance between each terminal, the induced occurrence caused by mutual induction from the parallel line can be determined. The main point is to compensate for the effects of electricity.

[Embodiments of the invention]

In the following description of the embodiment, it is assumed that there is a parallel line to the locating line during LL operation, and a failure occurs in the a-phase of the locating line. In addition, in the present invention, as shown in Fig. 3, the voltage and current of the oriented line of each terminal and the current of the parallel line are measured by each terminal device installed at each terminal of the power transmission system, and these voltages and currents are measured. After collecting the values at one location and synchronizing each measurement value, orientation is performed as follows. FIG. 1 shows an equivalent circuit per unit length when a parallel line exists for the locating line during IL operation. In FIG. 1, for the a phase, the self impedance Z as,
Mutual impedance with other phases in own line Zllb+
Z el, line mutual impedance Z with parallel line
jla ' + Z *b ' + Z ell
' is shown, similar impedances exist for other phases as well. However, since only the a-phase failure will be explained here, these impedances are omitted. Note that each of these impedance values is a value known in advance. Using the equivalent circuit in Figure 1, A
The voltage drop V, - per unit length from the terminal is determined by the following equation. VmaA=La1%+LI, Ib'+Zcalc"-'
−−−−−==−=−11) Similarly, the voltage drop per unit length due to the influence of the parallel line from the A terminal VaM'
1 can be expressed as follows. Vo'"=Z@@'I@'"+Lb'16'"+Z
ca'Ic'”−−−−−−−−−・−(2) Similarly, the voltage drop V per unit length from the B terminal
. When B is determined, it is expressed as the following equation. Va%=Zam1. B+Z@11L"+Z(11(a-
−−−−−−−−−−−−−−−−−−−−(3) Similarly, the voltage drop per unit length from the B terminal due to the influence of the parallel line Van' 8 is as follows: is expressed in Va% ””Zas'L'”+Zab'Ib'
”+Zc,'Ic' ”−〜−−−−−−−−−−
・-(4) Here, assuming an a-phase 1-wire ground fault, as shown in Figure 2, the a-phase voltage at the fault point F is set to V,', and the a-phase voltage at the A and B terminals is set to V-, V. @”, and the distance between the fault point F and the A terminal is αL (where L is the distance between the A and B terminals, and O〈
When α<1), the following equation holds true when considering the voltage drop from the A and B terminals to the failure point. By eliminating the unknowns y and F from equation (5) and finding the distance αL from terminal A to failure point F, it can be expressed as in the following equation. In this equation (6), each data on the right side is a value known in advance, a value measured at the A terminal or B terminal, or calculated using equations (1) to (4) based on these measured values. Since it is a value, the distance αLAW can be determined from this. Similarly, the distance (1-α)L from the B terminal to the failure point F can be calculated as shown in the following equation. Additionally, even if there are two parallel lines or a large number of parallel lines, location can be performed in the same way by taking in the current value of each parallel line and calculating the voltage drop due to the mutual impedance between the lines. can. Note that it is not necessary to take in the current value of the parallel line at both terminals A and 8 (in theory, the current value does not change at both ends if it is a healthy phase, and Ill in the equivalent circuit in Figure 1).
Since “Ill” + IbA = Ib” + Ic “Ic” holds true, it is possible to perform orientation even with the current value at only one end.Furthermore, it is also possible to perform orientation for failures in other phases and other types of failures. Location can be similarly performed by taking in the current value of the parallel line. [Effects of the Invention] According to the present invention, the current value of the parallel line is taken in in the same way as the current value of the location line, By performing orientation calculations that include mutual impedance between lines and parallel lines,
Highly accurate location is possible by compensating for the influence of induced electromotive force caused by mutual guidance from parallel overhead lines.

[Brief explanation of the drawing]

Fig. 1 is an equivalent circuit diagram per unit length of a power transmission system in which parallel lines exist, Fig. 2 is an explanatory diagram of the fault point locating method according to the present invention, and Fig. 3 is an illustration of a terminal system in which a terminal device is installed. A configuration diagram is shown. AI, Bl - terminal device, C - solid device, Z
am...-Self impedance, Z mb+Z
Cil - Mutual impedance with other phases within own line,
Z*@'+Z mb' + Z cm'...-
- Mutual impedance between lines and parallel lines.

Claims (1)

[Claims] 1) Measure the voltage and current of each terminal of the location line at each terminal device installed at each terminal of the power transmission system where the parallel line exists, and measure the current of the parallel line at at least one of the terminal devices, After collecting each voltage and current measurement value in one place and synchronizing each measurement value, calculate the voltage drop per unit length between the current measurement value of the location line and the current measurement value of the parallel line. , Fault point location in a parallel line installation system, characterized in that the fault point is located by a predetermined location calculation formula based on the voltage drop, the voltage measurement value of the location line, and the distance between each terminal. method.