JP2003270285A - Method for fault location - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fault location method which can relatively simply calculate a fault point at multiple faults time including different spot multiple faults. <P>SOLUTION: The fault location method comprises the step of calculating the fault point by installing electric quantity collecting terminals at both ends of a transmission line and using both end electric quantities having simultaneous time properties and known transmission line impedance and line length. The method comprises the step of obtaining a distance from an end of the transmission line of each channel to each fault point by using the voltage, current having the simultaneous time properties, self-impedance, mutual impedance and length of the transmission line measured at both ends of the transmission line of the phase decided as a fault occurring phase of each channel under the condition that fault point potentials calculated at both ends as start points on the transmission line in which the fault occurs so as to specify the fault points occurring simultaneously at each channel on two-terminal parallel two-channel transmission line. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an orientation method for identifying a fault point of a multipoint fault of different points across lines, which occurs on a 2-terminal parallel 2-line transmission line of a power system.
In particular, the present invention relates to a method of locating a failure point by using the amount of electricity (voltage, current) at both ends of a transmission line when a failure occurs.

[0002]

2. Description of the Related Art A method of locating multiple faults using the electric quantities of multiple terminals of a transmission line is, for example, Tanizawa and Tsuji's "Algorithm for transmission line FL considering multiple faults at different points" (1996 National Conference Papers No. 1523 p416 ~ p41
7) ”and Japanese Patent Publication No. 58305/1995 (Patent No. 202)
No. 0780), a fault point locating method (hereinafter referred to as a current locating method) and the like are known. The former orientation method is
This is a method to detect a fault point by the convergence calculation method using the voltage / current amount from each end of the transmission line and the known transmission line impedance.The latter orientation method is the voltage / current amount from each end of the transmission line. In addition, the known transmission line impedance is used to set the calculation point at which the potential of the failure point becomes equal when a failure occurs for each line as the failure point.

[0003]

In the above-mentioned conventional technique, the former needs to repeatedly perform calculation until a convergent solution is obtained, and the solution may diverge. Also,
The latter is a method that can detect only multiple failures that occur at one point. Therefore, the present invention is intended to provide a fault point locating method capable of relatively easily calculating a fault point at the time of multiple faults including multiple faults at different points.

[0004]

In order to solve the above-mentioned problems, the present invention is to install electricity quantity collecting terminals at both ends of a power transmission line, and to have electricity quantities at both ends having the same time and known transmission line impedance and line length. The present invention relates to a fault point locating method for calculating a fault point by using, and the invention according to claim 1 specifies a fault point that occurs simultaneously in each line on a two-terminal parallel two-line transmission line. The same time measured at both ends of the transmission line for each phase determined to be the fault occurrence phase of each line under the condition that the potentials at the fault points calculated from both ends of the generated transmission line are the same By using the effective voltage and current, the self-impedance of the transmission line, the mutual impedance, and the line length, the distance from the end of the transmission line of each line to each failure point is obtained.

More specifically, as described in claim 2, the distances from one end of the first and second lines to each fault point are αL and βL (L is the total length of the transmission line, α and β, respectively). Is 0
ΑL = (C · E−B · F) / (A · E−B · D) βL = (C · D−A · F) / (B · D−A)・ E) is used to find αL and βL. In the above formula, A = Z _s1 (I _A1 + I _B1 ), B = Z _m1 (I _A2 + I _B2 ), C = V _a1 −V _a1 ′ + L (Z _s1 · I _B1 + Z _m1 ·
I _B2 ), D = Z _m2 (I _A1 + I _B1 ), E = Z _s2 (I _A2 + I _B2 ), F = V _a2 −V _a2 ′ + L (Z _s2 · I _B2 + Z _m2 ·
I _B1 ), and Z _s1 is an in-line line constant consisting of the self-impedance of the fault phase in the first line and the mutual impedance of the fault phase in the first line with respect to the other phase, and Z _m1 is the fault phase in the first line. Inter-line line constant consisting of mutual impedance for each phase in the second line, Z _s2 : In-line line consisting of self-impedance of the fault phase in the second line and mutual impedance to other phases in the second line Constant, Z _m2 : inter-line line constant consisting of mutual impedance of each fault phase in the second line for each phase in the first line, I _A1 : current measured at one end of the first line, I _A2 : second line current measured at one end of, I _B1: currents measured at the other end of the first line, I _B2: currents measured at the other end of the second line, V _a1: measured at one end of the first line Voltage Sawasho, V _a1 ': first line voltage fault phase measured at the other end of the, V _a2: second line voltage fault phase measured at one end of, V _a2': the other second line It is the voltage of the faulty phase measured at the edge.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an example of a hardware configuration to which an embodiment of the present invention is applied. In the figure, 11 is a two-terminal parallel two-line three-phase power transmission line, and its total length L is known. Reference numerals 21 and 22 are terminals for collecting electricity such as CT (current transformer) and PT (transformer for measuring instrument) provided at the A end and the B end of the power transmission line 11, respectively.
Data conversion terminals 31 and 32 are further connected to 2.

[0007] When a failure occurs in the power transmission line 11, each end electricity amount, that is, each phase voltage, each phase current is the electricity amount collecting terminal 2
Data conversion terminals 31, 3
2 performs A / D conversion etc. and converts into a numerical value. At this time, by using, for example, GPS (Global Positioning System), the same time property of both-ends electric quantity data is secured. The amount of electricity of each phase collected at both ends of the transmission line is
1, 42 are collected in the central unit 50, and the fault point locating operation is executed here.

Now, as shown in FIG. 2 (a) or 2 (b), a failure occurs at two points F1 and F2 apart from each other in each line of a two-terminal parallel two-line power transmission line consisting of the power transmission lines 1L and 2L. In the case of the point multiple failure, in the section S1 or S2 sandwiched between the two failure points F1 and F2, the generated current distribution differs depending on the position of the failure point and cannot be accurately measured, resulting in a localization error.

Therefore, as shown in FIG. 3, the transmission line 1 of each line
When the fault point F1 is assumed to be closer to the A end side than the fault point F2 by using line constants such as voltage, current and known transmission line impedance which are collected at both ends of L and 2L and have the same time. The formulas for calculating the fault point potentials from both ends of the power transmission line as starting points for the power transmission line 1L side and the 2L side are set forth as Formulas 11 and 13 described later. At this time, the distance from the end A to the failure point F1 is αL, and the failure point F2
Let βL be the distance to. Note that α and β are both 0 to 1
Is a coefficient in the range of.

FIG. 3 shows a three-phase power transmission line having two terminals and two parallel lines, and assuming that the impedance Z per unit length (for example, 1 km) of the power transmission line is represented by Formula 1, Z will be used hereafter. _s1 (In-line line constant for the fault phase a1 in the transmission line 1L, generally, an in-line line consisting of the self-impedance of the fault phase in the first line and the mutual impedance of the fault phase in the first line with respect to other phases Constant), Z _s2
(In-line line constant for the fault phase a2 in the power transmission line 2L,
Generally, a line constant in the line consisting of the self-impedance of the fault phase in the second line and the mutual impedance of the fault phase in the second line with respect to the other phase), Z _m1 (line for the fault phase a1 in the transmission line 1L) Inter-line line constant, generally, an inter-line line constant consisting of a mutual impedance of the fault phase in the first line for each phase in the second line), Z _m2 (inter-line line for the fault phase a2 in the transmission line 2L) Constant, generally an inter-line line constant consisting of the mutual impedance of the faulty phase in the second line for each phase in the first line), I
_A1 (current at end A of power transmission line 1L), I _A2 (current at end A of power transmission line 2L), I _B1 (B at power transmission line 1L)
End current) and I _B2 (current at the B end of the power transmission line 2L) are defined by Expressions 2 to 9.

[0011]

[Equation 1]

Z _a1a1 in the equation 1 is the self-impedance of the a1 phase which is the fault phase in the power transmission line 1L,
Z _a1b1 is a mutual impedance between the a1 phase and the b1 phase in the transmission line 1L (the same applies to the following phases).

[ _Equation 2] Z _s1 = [Z _a1a1 Z _a1b1 Z _a1c1 ] [ _Equation 3] Z _s2 = [Z _{a2 a2} Z _{a2 b2} Z _{a2 c2} ] [ _Equation 4] Z _m1 = [Z _{a1 a2} Z _{a1 b2} 5] Z _m2 = [Z _a1a2 Z _b1a2 Z _c1a2 ]

[0014]

[Equation 6]

[0015]

[Equation 7]

[0016]

[Equation 8]

[0017]

[Equation 9]

Here, since the failure point potential of the failure point F1 in the power transmission line 1L calculated from the A terminal is the same as the failure point potential of the failure point F1 calculated from the B terminal on the opposite side, Numerical formula 10 is materialized about the electric wire 1L side. [Equation 10] V _a1 −αL (Z _s1 · I _A1 + Z _m1 · I _A2 ) = V
_a1 '-{(1-α) LZ _s1 · I _B1 + (1-β) L
_{Z m1 · I B2 - (β} -α) LZ m1 · I A2}

Therefore, Equation 11 is obtained. [Equation 11] αLZ _s1 (I _A1 + I _B1 ) + βLZ _m1 (I _A2 +
I _B2 ) = V _a1 −V _a1 ′ + L (Z _s1 · I _B1 + Z
_m1・ I _B2 )

Similarly, the failure point potential of the failure point F2 in the transmission line 2L calculated from the A terminal is the same as the failure point potential of the failure point F2 calculated from the B terminal on the opposite side. Equation 12 holds for the transmission line 2L side. [Equation 12] V _a2 − {βLZ _s2 · IA ₂ + αLZ _m2 · IA ₁ −
(Β-α) LZ _m2 · I _B1 } = V _a2 ′-(1-β)
L (Z _s2 · I _B2 + Z _m2 · I _B1 )

Therefore, Equation 13 is obtained. [Equation 13] αLZ _m2 (I _A1 + I _B1 ) + βLZ _s2 (I _A2 +
I _B2 ) = V _a2 −V _a2 ′ + L (Z _s2 · I _B2 + Z
_m2・ I _B1 )

Here, by setting A to F as in Expressions 14 to 19, Expressions 20 and 21 are obtained, and the distances αL and βL from the end A to the failure points F1 and F2 can be obtained. [ _Equation 14] A = Z _s1 (I _A1 + I _B1 ) [ _Equation 15] B = Z _m1 (I _A2 + I _B2 ) [Equation 16] C = V _a1 −V _a1 ′ + L (Z _s1 · I _B1 + Z _m1 ·
I _B2 ) [Equation 17] D = Z _m2 (I _A1 + I _B1 ) [ _Equation 18] E = Z _s2 (I _A2 + I _B2 ) [Equation 19] F = V _a2 −V _a2 ′ + L (Z _s2 · I _B2 + Z _m2・
I _B1 ) [Equation 20] αL = (C · E−B · F) / (A · E−B · D) [Equation 21] βL = (C · D−A · F) / (B · D−A)・ E)

Further, as shown in FIG. 4, assuming that the fault point F2 on the side of the power transmission line 2L is closer to the A end than the fault point F1 on the side of the power transmission line 1L, it is calculated with the A and B ends as the starting points in the same manner as described above. Since the fault point potentials of the fault points F1 and F2 are equal, the equations 22 and 23 and the transmission line 2 are used for the transmission line 1L side.
Equations 24 and 25 are valid for the L side. [Equation 22] V _a1 − {αLZ _s1 · IA ₁ + βLZ _m1 · IA ₂ −
(Α-β) LZ _m1 · I _B2 } = V _a1 ′-(1-α)
L (Z _s1 I _B1 + Z _m1 I _B2 ) [Equation 23] αLZ _s1 (I _A1 + I _B1 ) + βLZ _m1 (I _A2 +
I _B2 ) = V _a1 −V _a1 ′ + L (Z _s1 · I _B1 + Z
_m1 · _{I B2)} [number _{24] V a2 -βL (Z s2} · I A2 + Z m2 · I A1) = V
_a2 '-{(1-β) LZ _s2 · _IB2 + (1-α) L
Z _m2 · I _B1 − (α−β) LZ _m2 · I _A1 } [Formula 25] αLZ _m2 (I _A1 + I _B1 ) + βLZ _s2 (I _A2 +
I _B2 ) = V _a2 −V _a2 ′ + L (Z _s2 · I _B2 + Z
_m2・ I _B1 )

As described above, Equation 11, Equation 23, and Equation 1
3 and Formula 25 are the same, and regardless of the position of the fault point on each line, it is possible to specify the fault point on each line by using Formulas 14 to 21.

Next, the present invention was applied to carry out an orientation simulation when multiple faults at different points occurred. The system configuration for simulation is shown in FIGS. 5 and 6, and the used line constant is shown in FIG. 5 and 6, the total length of the power transmission line is 20 km, failure points F1 and F2 are set at a point 5 km from one end of this power transmission line, and 5 km from the other end of the power transmission line.
Failure points F3 and F4 were set at the points. Here, the impedance j4.5Ω in FIGS. 5 and 6 is the back impedance, the current 400A is the ground current, the resistor Rs is the short-circuit resistor, and the resistor Rg is the ground fault resistor. Incidentally, line constants shown in FIG. 7 respectively correspond to the matrix element of the formula 1 described above _(Z a1a1 _{~Z c 2c2).}

FIG. 8 shows a comparison of the orientation results obtained by the orientation method of the present invention and the existing orientation method disclosed in Japanese Examined Patent Publication No. 7-58305 (Japanese Patent No. 2020780).
In FIG. 8, “power supply on both ends, grounding on both ends” indicates the system configuration of FIG. 5, and “power supply on one end, grounding on one end” indicates the system configuration in FIG. 6. Further, each of cases 1 to 5 has two points as different point multiple failures (case 1 has failure points F1 and F).
2, Cases 2 and 3 are F1 and F4, Cases 4 and 5 are F
3, F2) is simulated, for example, “F1 1φG-A (5 km)” in Case 1 is the 1-line (A phase) ground fault at the failure point F1 and “F4 in Case 2”. 1φG-B (15 km) "is the 1-line (B-phase) ground fault at the fault point F4, and" F
12φG-AB (5 km) "is 2 at the failure point F1.
Line (A and B phases) ground faults are shown respectively. Other abbreviations are similarly interpreted.

According to FIG. 8, it is clear that the present invention can locate a failure point with higher accuracy than the current orientation method.

[0028]

As described above, according to the present invention, even in the case of not only a single point multiple fault in a two-terminal parallel two-line transmission line but also a different point multiple fault, there is a simultaneous electricity quantity at both ends of the transmission line. If the data is collected, the failure point can be easily specified by a relatively simple calculation regardless of the power supply arrangement and the grounding state.

[Brief description of drawings]

FIG. 1 is a configuration diagram of hardware used in an embodiment of the present invention.

FIG. 2 is an explanatory diagram of multiple faults at different points.

FIG. 3 is an explanatory diagram of out-of-point multiple failures for explaining the embodiment of the present invention.

FIG. 4 is an explanatory diagram of an outlying point multiple failure for explaining an embodiment of the present invention.

FIG. 5 is a system configuration diagram used for the simulation of the present invention.

FIG. 6 is a system configuration diagram used for the simulation of the present invention.

FIG. 7 is an explanatory diagram of used line constants in the simulation of the present invention.

FIG. 8 is a diagram showing simulation results of the present invention in comparison with the current orientation method.

[Explanation of symbols]

11, 1L, 2L transmission line 21,22 Electricity collection terminal 31, 32 data conversion terminal 41,42 Transmission line 50 Central device F1 to F4 failure points

Claims (2)

[Claims] 1. A condition that the fault point potentials calculated from both ends of the faulty transmission line as starting points are equal in order to specify the fault points simultaneously occurring in the respective lines on the two-terminal parallel two-line transmission line. The voltage and current measured at both ends of the transmission line, the self-impedance of the transmission line, the mutual impedance, and the line length are used for each phase that is determined to be the failure phase of each line under Then, the distance from the end of the transmission line of each line to each fault point is obtained, and the fault point locating method is characterized. 2. The fault point locating method according to claim 1, wherein distances from one end of the first and second lines to each fault point are αL and βL (L is the total length of the transmission line, and α and β are 0, respectively). .Alpha.L = (C.E.B.F) / (A.E.B.D) .beta.L = (C.D.A.F) / (B.D-) A · E) A fault point locating method characterized by obtaining αL and βL. (However, A = Z _s1 (I _A1 + I _B1 ), B = Z _m1 (I _A2 + I _B2 ), C = V _a1 −V _a1 ′ + L (Z _s1 · I _B1 + Z _m1 ·
I _B2 ), D = Z _m2 (I _A1 + I _B1 ), E = Z _s2 (I _A2 + I _B2 ), F = V _a2 −V _a2 ′ + L (Z _s2 · I _B2 + Z _m2 ·
I _B1 ), and Z _s1 is an in-line line constant consisting of the self-impedance of the fault phase in the first line and the mutual impedance of the fault phase in the first line with respect to the other phase, and Z _m1 is the fault phase in the first line. Inter-line line constant consisting of mutual impedance for each phase in the second line, Z _s2 : In-line line consisting of self-impedance of the fault phase in the second line and mutual impedance to other phases in the second line Constant, Z _m2 : inter-line line constant consisting of mutual impedance of each fault phase in the second line for each phase in the first line, I _A1 : current measured at one end of the first line, I _A2 : second line current measured at one end of, I _B1: currents measured at the other end of the first line, I _B2: currents measured at the other end of the second line, V _a1: measured at one end of the first line Voltage Sawasho, V _a1 ': first line voltage fault phase measured at the other end of the, V _a2: second line voltage fault phase measured at one end of, V _a2': the other second line Voltage of the faulty phase measured at the end)