JPS61164421A - Circuit selective relay device - 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 [Technical Field of the Invention] The present invention relates to a line selective relay device, and more particularly to trip prevention control of a quiesced interrupter trip circuit.

[Technical background of the invention]

In recent years, the trend toward digitalization aimed at power system control, quiescence using transistors and semiconductor blocking in well-logging equipment, and even microcomputer applications has increased significantly with advances in elements and information and communication technology. .

Under these circumstances, in the field of power system protection, the R Innotal Relay, which uses a microcomputer as a digital technology application, is moving from the research stage to the practical stage. However, even if the relay unit, which is the central part of the protection device, has been digitized, the reality is that the interrupter and the interface with external control equipment have not yet been made static.

As an example of this, a line-selective protection system applied to protect a two-line transmission line in a power system called a low-level system will be described.

FIG. 4 shows an example of a typical tripping circuit. In the figure, 152A
X and 252AX are respectively used for the second line 2L and have an interrupter (I L
CB), the normally open contact of the auxiliary relay that operates when the interrupter (21CB) for the second line 2L is closed, the main detection relay output from the digital relay IA for the first line (
When the auxiliary relays IMX and IFX are operated by the 1M relay) and the failure detection relay (IF relay), the a contact that becomes "closed" is used for the TL, and the interrupter ILCB'i
It is configured so that it can be pulled out.

Also, at this time, the second line 2L (illK) operates the digital relay 2A, and as a result, the main detection relay (2M) and the failure detection relay (2F) operate, and the 'auxiliary relay 2MX
, 2 Even if FX is closed, the blocking auxiliary relay 150TL is energized by the tripping command on the first line IL side, and the tripping circuit on the second line side is open.
No tripping current flows through the breaker on the second line 2L side. This is the first line IL side and the second line 2L
If the relationship between the two sides is reversed, the above-mentioned control circuit will simply be reversed. It is a problem in terms of the protection system that the interruption command for the first line IL and the interruption command for the second line 2L require mutually outputting blocking signals.

FIG. 5 shows the necessity of this function.

That is, it is a schematic explanatory diagram of a line selection protection method. Regarding this method, please refer to Denki Shoin board ``Protective Relay Technology'' (Kobayashi Ren), page 3.
Details are given from page 06 onwards.

Here, we will only discuss the necessity of mutual blocking assistance L/- (150TL, 250TL) by issuing a cutoff command to the interrupter on the first line IL side and the second line 2L side in Fig. 4 mentioned above. explain. Figure 5 (,) shows l L near the X terminal.
l [If there is an accident at point F, ≠ digital relay IA,
A fault current of 112. Similarly, second line 2L side current input transformer 2
Fault current I2. is taken in, and the difference current 1
．． , is synthesized.

"sF" Engineering IF -x2F ... (1
) Differential current, , is the second line 2L side fault current 11. Since it is larger than the fault current on the 2nd line 2L side, it becomes a positive value and it is determined that the fault is on the line 1 side, and the main detection relay's operating output IM
, the operation output IF of the failure detection relay causes the first
Auxiliary relays for tripping on the line IL side I MX , IF
Drive X. As a result, the interrupter on the first line IL side is tripped, and the interrupter ILCB is opened, as shown in FIG. 5(b).

After that, the fault current flowing to the fault point F disappears from the current flowing through the first circuit IL@, and flows around to the second circuit 2L side, causing the fault current to flow into the fault point F as shown in Figure 5. ．． is X
From the Y terminal 2L side via the terminal 2L@, the first line IL@
and flows to accident point F. Therefore, in the digital relay of the X terminal, the main detection relay and failure detection relay on the 2L side will output the operating side due to the current flow on the second line 2L side, and the trip condition will be satisfied. .

However, due to the operation of the blocking auxiliary relay 150 TL in the tripping circuit on the second line 2L side, the tripping circuit on the second line 2L side is opened by the contact 150TLob, so the interrupter on the second line 2L side is disconnected. can be prevented from being interrupted incorrectly. However, there is a fault current of 2 F in the transmission line up to the remaining t.This current is interrupted at the first terminal of the Y terminal.
Since the current on the line IL side is flowing in the internal direction of the power transmission line, control is performed to trip the interrupter on the first line IL side using the same principle and the same protection operation as the X terminal, as shown in Figure 5 (C). Therefore, only the terminal disconnectors of the X and Y terminals on the faulty line TL side are opened, the terminal disconnectors on the healthy line 2L side remain as they are, and power transmission/reception t remains at 11 in a healthy state.

The above is a function called sequential interruption of the line selective relay system, and explains the effectiveness of the blocking signals on the first line IL side and the second line 2L side described above. However, as mentioned above, along with the development of digital relay technology based on microcomputers, there is an urgent need to replace the mechanical mechanism of the trip circuit and the auxiliary relay that utilizes electromagnetic force with semiconductor elements. Under such circumstances, the application of a controlled rectifier element with a control pole (hereinafter referred to as a semiconductor switching element) is attracting attention in order to make the trip circuit stationary. The operating functions of this element are described in semiconductor books and the like. FIG. 6 shows an example of the characteristics of a semiconductor switching element. The symbol of the element is shown in (b) in the figure. (A, ni, G) are anode and cand, respectively.

It is a simple salt of f-). The reverse blocking region shown in FIG. 1 (1) has substantially the same characteristics as a normal diode. The forward blocking region is different from a normal diode, and the blocking voltage changes depending on the current control of f-), but when it is in the high conduction region in the figure, it is the same as the forward state of a normal diode, but at this time, the dart current Engineering. Engineering from 1. Even if the dart level is lowered to state 2, it will not return to the blocking state. To return to the blocked state,
The voltage between the anode and cathode may be opened or a reverse blocking voltage may be applied. That is, the relationship between the high conduction region characteristics of the semiconductor switching element and the III blocking region is as shown in FIG.
2 TX (252TX) is activated, the first line I
This is the same mode as the L side and operation continues until the interrupter is released. If the characteristics of such a semiconductor switching element are used to construct an interrupter string removal circuit, the result will be as shown in FIG. Main detection relay operation output IM, failure detection relay operation output I output from digital relays IA and IB
By operating F, the semiconductor switching element 5C is connected via the dart input interfaces 5A and 5B'i.

A current is input to the dart of 5D, and the semiconductor switching elements 5C and 5D are both high conduction regions. As a result, the interrupter is opened, and the anodes and cathodes of the semiconductor switching elements 5ρ and 5D are in an open state, so that the blocking state can be maintained even if the interrupter is turned on after a predetermined period of time.

In addition, in the circuit shown in Fig. 7, when a system fault occurs outside the protected area and the fault detection relay IF operates, the main detection relay is inoperative, and the IM is inoperative, the semiconductor switching element 5C f-) receives current. does not flow and remains in a forward blocking state, and even if current flows through the gate of semiconductor switching element 5D, no forward current flows between the anode and cathode. Therefore, there are no more accidents,
When the f-) current of the semiconductor switching element 5D disappears, it returns to its original state.

The above is an application circuit of a controlled rectifier with a control pole when aiming to make the interrupter line removal circuit stationary.

[Problems with background technology]

However, when such a semiconductor switching element is used, it is impossible to create a signal that can confirm that a tripping command has been issued to the interrupter, that is, a signal corresponding to 152TX (252TX) in FIG. 4. There would be no problem if the 152TX shown in FIG. 4 could be connected to the tripping circuit that has been made stationary as shown in FIG. 7, but this would greatly deviate from the purpose of making it stationary.

[Purpose of the invention]

The present invention has been made to solve the above-mentioned problems, and even when a semiconductor switching element is applied to the line selection protection system line disconnection line removal circuit, it is possible to reliably connect the line disconnector on the fault line side. It is an object of the present invention to provide a line selection relay device that can confirm that an interruption current has flowed and prevent erroneous disconnection of a healthy line.

[Summary of the invention]

In the present invention, in place of the contacts of the conventional line selection relay and fault detection relay, a semiconductor switching element is used to create a nine-trip circuit, and the ON/OFF state of this semiconductor switching element is
The off operation is configured by a flip-flop element and a logic circuit, and a signal that becomes "1" when there is no command to trip the disconnector of the other line is input to the set side of the flip-flop element, and both lines are By operating a signal that becomes "1" when at least one of the interrupters is closed as the reset side input, and holding the set side input when the reset side input is "0", each semiconductor switching element is operated, and the same selectivity as in the case of conventional contact operation can be obtained even when the switch is stationary.

[Embodiments of the invention]

Examples will be described below with reference to the drawings. FIG. 1 is a diagram showing an embodiment of a line selective relay device according to the present invention.

In FIG. 1, 5C1 and 5D1 are semiconductor switching elements, which correspond to the contacts I MX and I FX of the main detection relay and failure detection relay described in the conventional example. 5A1.5A2 are semiconductor switching elements 5C1, 5
The input from the digital relay IA on the first line side is introduced at the dart input interface connected to the dart circuit of D1. There are inhibit circuits 63M and 63F inside the digital relay 1A, and the inhibit input terminals of the inhibit circuits 63M and 63F are commonly connected to the output terminal of the flip-flop 7'FF1.

The other input terminals of the inhibit circuits 63M and 63F are connected to the inputs of the main detection relay IM and the failure detection relay 1F, and the set input terminal (S) of the flip-frog circuit FFI is connected to the input terminal from the second line side, which will be described later. 250 of
The TL output is connected, and the reset terminal (the mallet is commonly connected to the flip-flop FF2 on the second line side, and connected to the NAND circuit 62.The NAND circuit 62 has the respective cutoff terminals for the first line and the second line). Open/close signal 152A of the pallet switch of the container.

252 people are input. Moreover, the semiconductor switching element 5
Photocoupler-6 people 1, 6 are installed in parallel in C1, 5D1, respectively.
11 is connected via a resistor 64, and the phototransistor of the secondary example is connected via a NoRl circuit 61 to the sector input terminal (2) of the flip-frog FF2 in the digital relay for the second line. Furthermore, 152-a
, 252-a is the pallet switch of the interrupter. Although the above explanation concerns the first line side, the second line side is also completely similar. And the NOR circuit 61□ on the second line side
The output 250 TL is input to the set input terminal (S) of the first line FFI.

The operation of the line selection relay device having the above configuration will be explained.

First, the steady state will be explained. 1st line interrupter N180
The output of circuit 62 is rOJ. Therefore, the flip-frog (FFI, FF2) is reset (a "0" signal is input to the input side, and the flip-frog (FFI, FF2) is reset.
, FF2) both depend on the state of the set signal. or,
Semiconductor switching elements 5C1 and 5D1 are both in the OFF state (forward blocking state) K, and photocouplers 6AI and 6B1
Current flows through the limiting resistor 64 to the primary side, the outputs of the photocouplers 6A1 and 6B1 are both "1", and the gate 6
1 to the second line 2L side digital relay IB, and the flip terminal 7' F F 2's Sera) (
S) side. The same can be said of the photocoupler on the second line 2L side. That is, the photocoupler output 250 TL from the second line 2L side, which is taken into the digital relay IA, is input to the set side of the flip-flop FFI. Therefore, when the output of the flip-frog FFI is "0", the inhibit circuit 63
It is input to M, 63F.

Next, the response when the accident shown in FIG. 5-) occurs on the second line 2L side will be explained. That is, if an internal accident occurs in the first line IL, the main detection relay I of one digital relay
M and failure detection relay IF become operational, the outputs of inhibit circuits 63M and 63F of digital relay IA are both Kr1-J, and dart input interface 5A1
．． Semiconductor switching elements 5C1, 5D via 5B1
1 turn on together and enter the high conduction region with the characteristics shown in FIG. 6, and the coil (152
A current flows through TC) to operate. As a result, the first line IL side interrupter (ILCB) interrupts, and a signal 152 that is "O" is input to the NAND circuit 62 when the first line IL side interrupter (ILCB) opens. , the output of the NAND circuit 62 becomes "1", the reset side Kr1J of the flip-frog FF2 mentioned above is input, the output of the digital relay IB is blocked to the "0" side, and the fault occurs on the second line 2L side. To prevent erroneous disconnection on the healthy line side by outputting a tripping command to the interrupter (2LCB) on the second line 2L side even if the line is open and in a state corresponding to (b) in Fig. 5. I can do it. The flip-flops FFI, FF2, or inhibit circuit 63 in the digital relays IA and IB, which are mentioned repeatedly in the above explanation, are all for explaining the functions and are not actually included. Interrupter information and the like are processed by a program to satisfy the above functions.

Figure 2 shows a configuration diagram of the digital relay. The current and voltage obtained through the current input transformer CT and voltage input transformer PD in FIG. 2 are input to an input converter 21 that converts them to a predetermined output level. The output is input to a filter 22 for removing undesired frequency components, and the output is sampled at a constant sampling period and held by a temple hold circuit (S/H) 23 that holds it until the next sampling.
and MPX 24 that converts its parallel output into serial data.
Analog-to-digital converter (A/D) 25 through
is converted into a digital quantity. The data converted into digital quantities is stored in a data memory (RAM) 26, and a predetermined protection operation is executed in the CPo 28 according to a program memory 27 that stores a protection operation program. Also, the LL side is necessary for protection calculation.

Contact 15 of the auxiliary relay that indicates the open/close status of the interrupter on the 2L side
The states of 2A and 252A are taken into the input/output interface 30 via the interface 29. Furthermore, the results of predetermined protection calculations and logic control are sent to the input/output interface 3.
0 and an external device interface to output a trip circuit command.

That is, the trip circuit command is w, the output LM in Figure 1.

This corresponds to the output through the 1F and the inhibit circuit.

Further, the setting section 31 in FIG. 2 includes an interface and a dedicated memory for taking in necessary table setting values for relay operation determination calculations, etc.

Although the present invention has been described with reference to only semiconductor switching elements, it goes without saying that similar effects can be expected in tripping circuits in which conventional auxiliary relay contacts are applied instead of the aforementioned elements.

An example of this is shown in FIG. Auxiliary relay IMX in Figure 3
It goes without saying that IFX, 2MX, and 2FX have the same purpose as the auxiliary relay shown in FIG. 2-line power transmission line image Even if a semiconductor switching element is applied to the line-selective protection system's line disconnection line removal circuit, it is possible to ensure that an interruption current has flowed to the line-breaker on the fault line side. By checking this, you can prevent accidental disconnection on the healthy line side.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is an example diagram of an inter-line trip prevention circuit applied to a line selection relay device according to the present invention, and FIG. 2 is a configuration diagram of a digital relay that is a relay to which the present invention is applied. Figure 3 is a diagram of another embodiment of the line-to-line trip prevention circuit, Figure 4 is an example of a conventional tripping circuit, and Figure 5 is the need for a mutual prevention function in a line selection protection system or disconnection line disconnection circuit. 6 is a characteristic diagram of a semiconductor switching element, and FIG. 7 is a diagram illustrating an example of a circuit for removing a circuit breaker from a semiconductor switching element. IA, IB...Digital relay 5A, 5B...Semiconductor switching element Dart input interface 5C, 5D...8CR circuit 6Al, 6Bl, 6C1, 6Dl...Photocoupler circuit (7317) Agent Patent attorney Nori Chika Kensuke (and 1 other person) 5th illustration

Claims (1)

[Claims] A line selection relay device that protects a two-line power transmission line includes a first means having a function of selecting a faulty line, a second means for detecting occurrence of an accident, and a command to trip a breaker of another line. The set side input is the signal that becomes ``1'' when the circuit breaker is not closed, and the reset side input is the signal that becomes ``1'' when at least one of the circuit breakers on both lines is closed, and when the reset side input is ``0''. a third means having a flip-flop function for holding a set-side input; a fourth means having an AND function whose inputs are the knot output of the third means and the output of the first means; a fifth means having an AND function that takes as input the knot output of the means and the output of the second means; a sixth means that takes the output of the fourth means as input and converts it to a predetermined level; A seventh means inputs the output of the means and converts it to a predetermined level, and the outputs of the sixth means and the seventh means are inputted to each gate and connected to the anode.
A predetermined voltage is applied between the eighth means and the ninth means, each comprising a control rectifier with a control pole that causes a breaker tripping current to flow between the cathodes, and the anode and cathode of the eighth means and the ninth means. tenth means for detecting that
The outputs of the first means, the tenth means, and the eleventh means are input, and when each is in the state of "0", it is judged as "1", that is, a tripping command is issued to the tripping circuit of the own line. and twelfth means for detecting that no output is being output.