JPS60164263A - Ground fault point locator - Google Patents

Abstract

PURPOSE:To make the equipment simple and inexpensive by measuring the distance to a fault point from affected current generated in the power system in case of a ground fault in one line. CONSTITUTION:A change-over switch 103 is connected to the lower position in case of a fault in one line. A multiplier 104 outputs a zero phase current I02 on the side of the sound circuit as introduced through the changeover switch 103 as 2-fold component. Then, an addition circuit 105 adds components applied from input terminals 101 and 102 and outputs I01 (zero phase current of the affected circuit)+I02. Then, an arithmetic circuit 107 divides the output component of the multiplier 104 by the output component of the addition circuit 105, subsequently, integrates the total length Lkm (total length of the parallel 2-line system) from a memory circuit 106 to compute the distance (x) to the fault point and outputs it to an output terminal 108.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a ground fault point locating device for two parallel circuits in a power system.

[Prior art]

It is already known that there are fault point locating devices for power systems that utilize traveling waves, such as a method that applies all of the shock waves and a method that uses all of the fault surge.

However, when applying or receiving a traveling wave to the consolation path, v
The cTri must be passed through the entire coupling device-1
)) has the drawback that the device becomes complicated and expensive. Device 1 designed to measure the distance from the fault point to the fault current L generated in the power system at the time of a ground fault. provide.

[Example of actual invention]

Figure 1 shows a parallel two-circuit power system, with an ill base source, a +21 Vi transformer, a +31 tri neutral point resistor, '41 a bus bar, (line 1 of a 61-parallel two-circuit system,
6) is the line 2, (7) is the busbar, (8) is the transformer, (
9) is the load, (10) is the failure point, (Ill and (121)
What are the zero-sequence current components of line 1 and line 2 of a parallel two-line system?
The derived current transformer (T100) shows a ground fault point locating device according to an embodiment of the present invention.

Figure 2 is a diagram showing the symmetrical division f[r when a 1 #il ground fault occurs at the fault point (1ω) in Figure 1, where the shw is a positive phase circuit, (2) is a negative phase circuit, @Vi 岑 phase in-phase circuit C), the current transformer in Figure 1 (Ill, 02'K), the installation point Kl or t' of the fault point locating device (100) corresponding to K, and all the current transformers. The symbols in the figure are as follows.

E: Power supply ZSI: Positive sequence impedance behind power transmission side z82: Transmission a
Reverse-sequence impedance behind st++
positive-sequence impedance per unit [km] of the parallel two-line section zQ: negative-sequence impedance per unit [-] of the two-parallel line section ZRI: positive-sequence impedance behind the receiving side ZR2 : Negative phase impedance behind the power receiving side [k
m] L: Length of two parallel circuits [km] zm: Mutual immunity between circuits per unit [km] o1: Zero-sequence current Io of line 1 of two parallel circuits system:
Zero-phase iron flow circuit F of line 2 of parallel two-circuit system: Fault point current Figure 3 shows the circuit aIW mutual impedance flow in detail in the zero-phase circuit of Figure 2. From FIG. 3, since the voltage drop L due to the zero-sequence current flowing in line 1 is equal to the zero-sequence current flowing in voltage regulator No. 2 #l, the following equation +11 is established.

xZo ol+xZmIoz-xZmIox+LZo
Engineering 02-(L-xlZmIo2+(L-x)Zo Engineering 02
-(L-x) Zm 02...+11 formula + 11 formula is organized as x(Zo-Zm) ox+=(2L-XNZO-Zm)
Distance 1 from becoming IOll to failure point? IX is calculated using the following equation (2).

Equation (2) is a formula to measure the fault point distance when a 11Id ground fault occurs in line 1 of a parallel two-line system, but when a fault occurs in line 2, #'i + 0λ in the equation 21 and work 0
Since the equation is a 2/14 conversion, it can be measured using the following equation (3).

Diagram iM4 is a diagram showing the earth fault point locating device (lOO).
- (101) is the input terminal of the 1st line, the input terminal of the line 2, the input terminal of the 0 phase o phase stream component,
(103) is an input selector switch that responds to a fault detector (not shown), (,104) is a multiplier (5) is an adder circuit, and (106) is the length L [k+] of the parallel two-line system.
n) A device for k storage, (10'7) is an arithmetic circuit that also serves as division and addition, and (8) is an output 1 child.

Next K! I will explain the works by IIIJ.

Figure 4 shows a complete diagram of the situation when a No. 1 mVC failure occurs.When a failure occurs, it is determined whether the failure occurs in the No. 1 line or the 2υ゛ line by using the fault detector provided by Hono Relay Electrical Temple (Figure C omitted). When the 1st string failure is detected, VC is set to K h'Jt, which the changeover switch (103) connects to the lower side on the drawing (when the 2nd string failure is detected, VC is set to the upper side on the diagram [II]). configuration). In the multiplier (104), the current is multiplied by a changeover switch (103) and outputted as a total double (zero-sequence current of line 2 of the parallel two-line system). Next, addition 11
In (105), is the voltage applied to input terminals (101) and (102)? Ingredients? After addition, the H+Io2 component is output. Then, the arithmetic circuit (lo'7) multiplier (11) 4
Divide the output component of 1 by the output component of the adder circuit (105), and as a result, the length L Cm from the storage circuit (c)
(Length of parallel two-line system) The distance to the failure point shown in equation (2) above is computed by #X% - output terminal (X) 8
) Vc small output.

If a failure occurs on the Line 2 side, the failure detector KL
Since the selector switch (103) is connected to the upper side in the drawing, the distance t and the distance X shown in equation 13) are output to the output terminal (108) without being calculated.

In this way, according to the above embodiment, the distance from the fault stream to the fault point when a fault occurs is measured at 8F.

In addition, in the above embodiment, the fault detector detects the operation O1 and IO2.
As explained in the changeover switch (1O3), it is not a switch mechanism, but a parallel switch for line 1 and line 2.
It would be pointless if the post-processing section performs all the computations for the necessary components and then calculates all the distances that are likely to fail.

[Effect of Origin 1] As shown below, if this invention is not modified, K'i will be reduced when a failure occurs.
(i: Since the device is configured to measure the entire distance from the failure occurrence occurring in the force line trajectory to the failure intention, the device is simple and inexpensive.

44. Brief explanation of the drawings Figure 1 shows a vehicle power system with two parallel circuits, and Figure 2 shows...
Figure g1 shows the symmetrical +o+ path when a one-line ground fault occurs, Figure 3 shows the zero-phase circuit of Figure 8g2 in detail, and Figure M4 shows the ground fault point according to this invention. Location device t T
It is a figure shown in h.

In the diagram Vζ, (101) is the input terminal of the factory o1, (xoz
) t/'1IO11 input terminal, (103) is a changeover switch, (104) is a multiplier, (1051 is an adder circuit, (1
06) is a storage device, (107) is an arithmetic circuit, and (+8) is an output terminal.

In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Agent Masuo Oiwa Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] Locating the fault point in two parallel circuits of the power system V
C'J3, there is a multiplier that doubles the zero-sequence current on the healthy line side of the two parallel circuits by four people, and a failure N of the two parallel circuits.
An adder circuit that introduces and adds the zero-sequence current on the line side and the zero-sequence current on the healthy line side, and determines the fault point from the output of the multiplier, the length of the two parallel lines, and the output of the adder circuit. An arithmetic circuit that calculates the distance to? Equipped with a ground fault fault location device.