JPS6026420A - Loop switching discriminator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] The present invention detects and inputs the phase difference or potential difference between the voltages at both ends of a normally open loose switch, and when the loop switch is closed based on data determined from line constants. The cross current value is calculated using a calculation program prepared in advance.

The present invention relates to a loop switching determination device that determines whether or not the loop switch is closed.

As a conventional loop switching determination device, there is one that detects a voltage phase difference between both ends of a normally open loose switch.

FIG. 1 shows this loop switching determination device, in which lead wires 1 at both ends of a loop switch 1o installed between two substations are shown.
1.12 and detects the voltage signal across the loop switch 200.The power distribution network of the substation where the loop switch 10 is installed is connected to the power supply via the transformer 18.19. The voltage signals from both ends of the loop switch 1o detected by the receiving circuit 14 are processed, and the phase difference between the voltages at both ends of the loop switch 1o is determined and displayed. When the phase difference is detected, the cross current value corresponding to the phase difference is calculated from the graph shown in FIG. 2, and it is determined whether or not the loop switch IO can be closed.

The graph in FIG. 2 is drawn with the total impedance %Z in the loop as a parameter, the cross current value μ as the vertical axis, and the phase difference between the voltages at both ends of the loop switch 100 as the horizontal axis.

However, according to the conventional loop switching determination device, after actually measuring the phase difference between the voltages at both ends of the loop switch, the cross current value is calculated based on the cross current value-phase difference graph from this phase difference and the total impedance of the loop. Since it is determined whether or not the loop switch can be closed, it is troublesome and may take a long time to make the determination.

The present invention has been made in view of the above, and in order to easily and quickly determine whether or not to close a loop switch,
When the phase difference or potential difference between the voltages at both ends of a normally open loop switch is detected and input, the cross current value when the loop switch is turned on is determined by a pre-prepared calculation program based on data determined from line constants. calculate,
The present invention provides a loop switching determination device that determines whether or not the loop switch can be closed.

Hereinafter, the loop switching determination device of the present invention will be explained in detail.

FIG. 3 shows an embodiment of the invention, in which parts identical to those shown in FIG. 1 are designated by the same reference numerals.

The loop switching determination device is a loop switch 100 ROM2
1. Equipped with a RAM 22, etc., an input interface 23, a phase measuring device 7, and an arithmetic program.

It has an auxiliary memory 24 storing various data, a keyboard 25, etc. connected thereto, and an output interface 26 connected to a display 27, a printer 28, etc., and a calculation means 29 consisting of a microcomputer.

In the above configuration, the loop switching determination device both performs processing using the arithmetic grograms based on FIGS. 4 to 12, determines the cross current value, and determines whether or not the loop switch 10 can be closed.

The operations performed in the above calculation program will be explained below.

The calculation means 29 started by the operator starts the process based on FIG. Initial processing 30 based on the initial processing subroutine shown in the figure is executed.

When the initial condition settings are completed, following the program start display 31, the following five types of operations and the numerical values corresponding to each operation are displayed on the display 27 (this is the type display 3).
2).

, DATA INPUT (operation of inputting data from the keyboard 25 and writing it to a file)... "l"
Display, FILFI! 5HUiT (Operation to modify data that has been written once)...Display "2" oDATA
LIST (cleaning to print file data)・
...? 3" display oOALC!ULATION (operation to perform calculation)... 4# display oEND (operation to end the program)... - 〇" display If everything is entered in , type 4 (C
When AL 0ULATION) is selected, the arithmetic processing based on FIG. 12 is executed, and the cross current value is displayed on the display 27 and printed out on the printer 2B (33 in FIG. 12).

Based on this cross flow, it is determined whether or not the loop switch 1o can be closed.

In the above-mentioned embodiments, the phase difference was used to calculate the cross-current value, but for the reason explained below, even if the potential difference between both ends of the loop switch 10 is used, the cross-current value based on the above calculation program is less than 0. can be confused with a well-known general formula, but in this embodiment, a simplified formula shown in formula (11) is used.

1520 Engineering ξ Ki %

The voltages VA and Vn of the electric lines (feeders) A and B and the phase difference Δθ have the relationship shown in FIG. 13, and the phase difference Δθ causes a potential difference ΔE. This voltage is N'A, V
Since it is a voltage perpendicular to y with respect to a, it can be expressed as jΔE. Also, the impedance of the electric line and transformer is
Since most of it is a reactance component, it can be expressed as jX. Including, when considering arbitrary two points a and b in a circuit network including a power supply as shown in Fig. 14, this point a,
I-j""z by shorting b.

ΔE An effective current of = F flows (Thevenin's theorem).

If this I is assumed to be loop cross current II and reactance X is constant, it is proportional to ΔE. Also, ΔE is Δ in the range where Δθ is small.
Since it is proportional to θ, the loop cross flow coefficient λ is as follows by measuring Δθ.

Equation (3) is derived from the relationship between V and ΔE shown in FIG. holds true.

However, P = 10000 (KVA) E -6,6 (
KV) Therefore, the loop cross-flow 11 is expressed by equation (6).

Next, a case will be described in which various data are input to the arithmetic unit 29 and the loop cross current value, the phase of each point, etc. are calculated.

If -1” (DATA INPUT) is selected in the main routine type INPUT38 in Fig. 4, the 5th
Processing based on the data manual subroutines shown in FIGS. 8 through 8 is executed.

In the feeder display 34 of FIG. 5, feeders A and B
11# for feeder A and 12- for feeder B are displayed in the corresponding numerical values, and data is input for each system. Input is performed from the keyboard 25 based on the operation number display 35 (the operation number list is shown in Table 1).

Table 1 - At operation number INPUT 36 in Figure 5, select the desired number, enter the percentage impedance %X, percent power %P, etc. (37 in Figure 6), and then input the type of wire, size, etc. (39.40 in Figure 7). Then, enter the length of the wire and the current flowing through the section (
41°42 in Figure 8). After inputting all the data, enter @4” (OALOULAT) in type INPUT38.
ION), predetermined arithmetic processing is executed, and the phase of each point is displayed and printed out in step 33 of FIG.

The error displays and printouts for each program in Figures 4 to 8 and Figure 12 are as shown in Figures 9 and 1.
The program is executed based on the program shown in Figure 0.

As described above, according to the loop switching determination device of the present invention, when the potential difference is detected and inputted, the phase difference between the voltages at both ends of the normally open loop switch is determined based on the data determined from the line constant. Since the cross current value when the loop switch is closed is calculated using a calculation program prepared in advance, it is possible to easily and quickly determine whether the loop switch is closed.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a conventional loop switching determination device, FIG. 2 is a cross current value-phase difference characteristic diagram, FIG. 3 is a diagram showing a loose switching determination device according to an embodiment of the present invention, and FIGS. FIG. 12 is an explanatory diagram of the operation of a loose switching determination device according to an embodiment of the present invention, and FIGS. 13 to 15 are explanatory diagrams for deriving arithmetic expressions. Explanation of symbols 10... - Loop switch 11.12.15.16... Lead wire 13.14...
・Detector 17... Phase measuring device 18.19... Transformer 20... 0PU21...-ROM 22-RA
M 23... Input interface 24... Auxiliary memory 25... Keyboard 26...
・Output interface 27... Display 28... Printer Figure 3 Figure 4 Figure 7 -106-

Claims (1)

[Claims] Based on the voltage signals at both ends of the normally open loose switch, a phase difference b between the voltages at both ends is a detection means for detecting the potential difference, and when the output signal of the detection means is input, the line constant 1. A loop switching determination device comprising: calculation means for calculating a cross flow value when the loose switch is turned on based on data determined from the above, using a calculation program prepared in advance.