JPS6014575B2 - Phase comparison transport protection relay system - Google Patents

Description

[Detailed Description of the Invention] The present invention is an electrical station in which a phase comparison conveyor protection relay system is installed in stages, and is used to prevent unnecessary damage in the event of an internal accident of a circuit breaker that is emptied for inspection of a circuit breaker. Regarding prevention of interruption.

As the protection relay system layer for important power transmission lines such as the so-called main power transmission lines of the power system, a high-speed operation, high-reliability transport protection relay system layer with excellent protection performance is generally adopted.

In particular, high-voltage and ultra-high-voltage power transmission lines are equipped with a phase comparison transport protection relay system layer for each phase that can be applied to a multiphase reclosing method that selectively disconnects only the failed phase and recloses the circuit at high speed. By the way, in a system where a phase comparison transfer protection relay system is installed, for the purpose of inspecting a break or break in a transmission line that is treated as a variable power supply end, it is necessary to connect the line switches on both sides of the break or break. If an internal accident occurs in the transmission line when one end of the transmission line is being charged from the other power supply end while the disconnector is open, as long as the conventional phase comparison transport protection total electrical equipment layer is installed, it will not be possible to do so later. As will be explained in detail, this causes problems such as unnecessary shearing of the sheath disconnector during empty charging, and interfering with inspection work of the sheath disconnector.

Here, in the present invention, the inspection of the breaker literally refers to the breaker itself (the main body and the field panel near this), and it also refers to the inspection of the breaker in the final stage from each relay in the central unit room that houses the relays. Some even test the trip coil.

Regarding the former, it is natural that workers are nearby, and a sudden release that the worker is unaware of will cause a great deal of mental pain due to impact noise and vibration. Depending on the situation, it may be dangerous. In order to prevent this, it would be possible to proceed with the inspection by opening the circuit of the tripping coil to prevent it from operating due to an internal accident, but ``we must be careful of human error caused by rewiring, so it is not practical.'' Inspection that locks the circuit like this, especially in the case of the latter inspection, may significantly narrow the scope of inspection.
For example, when opening the connection between the unit room and the field panel, it is impossible to perform a complete system inspection. From the above, in the present invention, rather than ``opening a part of the circuit or preventing the output from being given to the outside when the L or protection relay operates,'' The purpose of this is to eliminate problems during inspections of disconnectors by creating a situation in which they cannot operate depending on the situation.

In the present invention, firstly, during inspection, one-end charging operation is performed, and the line switches on both sides of the inspection end and disconnector are opened, and ``inspection is confirmed by opening them.

Second, we focused on the fact that when the line switch is open, the current is zero, and by creating a trip permission signal at the variable power supply terminal and sending this to the power supply terminal, it is possible to open the power supply ship in the event of an internal accident. Furthermore, thirdly, we focused on the fact that by inverting the trip permission signal when the line switch is opened to make it the phase signal of the own end, it is impossible to respond to any fluctuations in the carrier from the power supply end during inspection. By doing this, the sudden opening of the disconnector can be completely prevented, and in this case, it is not necessary to lock the protective appliances or open the wiring, so the system can be inspected once again. There is no human wiring error.Hereafter, we will explain the phenomenon in which the disconnector disconnects unnecessarily due to an internal accident during a dry turn on and inspection at the L variable power supply terminal while charging one end of the line from the power supply terminal. After that, one embodiment of the present invention will be described in the fifth embodiment.
This will be explained with reference to the drawings.Prior to that, the operating principle of the phase comparison conveyance protection relay system will be explained with reference to FIGS. 1 and 2.

FIG. 1 shows a power system in which the phase ratio shark relay 7 is installed, and the phase ratio shark relay is installed at an electric station A and an electric station B. Items common to both electrical stations are designated by the same reference numerals. Reference numeral 1 indicates a busbar, and reference numeral 2 indicates an integrated generator behind the electric station. When an accident occurs on a power transmission line or the like, fault current is supplied from this generator.

The bus bars 1' of electric stations A and B are connected to each other by a power transmission line 5 via a disconnector 4. When an accident occurs on the transmission line 5, the current transformer 3 installed at both electric stations directs the relay side current 6 proportional to the fault current flowing through the transmission line 5 to the phase comparator 7', and outputs the output circuit of 7. By 11, the shiya danki turtle is released. The current 6 guided to the phase comparison relay T is converted from a sinusoidal alternating current into a rectangular wave by a rectangular wave shaping circuit 8 inside the phase comparison termination device.

In the phase ratio relay that is treated as the end of the electric wire at electrical station A, the rectangular wave created by the positive half wave that exceeds the lever LM becomes the trip permissible phase signal (hereinafter referred to as the F2 signal). becomes a phase signal (hereinafter referred to as F signal). In addition, in the phase comparator terminator that is treated as a variable power supply terminal at electric station B, the rectangular wave created by the current on the side that includes zero from the bell ZL becomes the F2 signal, contrary to the power supply terminal, and the other section becomes F, a signal. The phase signal generated in step 8 is guided to the matching circuit 9 (actually, it goes through a circuit that compensates for the transmission delay time until the phase signal transmitted from the other end reaches the matching circuit 9 of the own device, but (omitted for brevity), the information is transmitted to the transmitter 3 of the information transmission device 2, and generally to the microwave line 5.
is transmitted to the receiver turtle 4 of the other end information transmission device b2.

On the other hand, the phase signal at the other end, which is sent through the microwave line 15 by the transmitter 3 of the information transmission device 12 at the other end of the same aircraft, is transmitted through the receiver turtle 4 of the information transmission device 12 at the own end, It is introduced into another input of the matching circuit 9 of the relay 7. In the matching circuit 9, an AND signal of the F2 signals at both ends is created, and the magnitude of this signal is measured in the next integrating circuit 10 and is determined to be a magnitude that can be determined as an internal accident that should be protected (generally 60 o
), the output circuit 11 issues a command to trip the shingle breaker 4. Although only one set of phase comparison relays is shown in Figure 1, in each phase phase comparison method, A
``The B and C phases are installed for each phase, and the above-mentioned operations are performed independently for each phase.Next, referring to FIG. 2, we will explain the response of the system shown in FIG.

Components in FIG. 2 that are the same as those in FIG. 1 are designated by the same reference numerals. Figure 2a shows the response to an accident outside the protected area, and as shown, the accident point is outside electric station B.

Therefore, the current on the relay side of the transformer 3 is A terminal 6A and B terminal 6B.
Then, both the size and the phase will be the same. The A terminal current treated as the power supply terminal is 8, and as shown in 8A, it is converted into a rectangular wave by the slice level LH and becomes the F2 signal, and the other sections become the F signal. The B terminal current treated as a variable power supply is changed to a rectangular wave by the slice level LL at 8, and the other sections are F2 signal as shown in 8B, contrary to the A electric station treated as a power supply terminal.
It becomes a signal. In the coincidence circuit 9, if the F2 signals of 8A and 8B are ANDed, as shown in 9A and 9B, there is no AND output of 9, and therefore the integration circuit of 10 and the output circuit of 11 have outputs of 10A, 10B, 11A, and 11B, respectively. As shown in , there is no signal at all, so no breaker tripping signal occurs. Here, it is a well-known fact that the slice level LH at the fin source end and the slice level LL at the variable power supply end are configured such that LH>LL so that the F2 signals at both ends do not overlap due to an external accident. FIG. 2b shows a case where an internal accident occurs when power is supplied at both ends, and as shown, the fault point is on the power transmission line 5 connecting electric station A and electric station B.

Due to an internal fault in the section, contrary to Figure 2a, the relay side current A of transformer 3, total 6A, and B end 6B are almost in opposite phase, 8
As shown in A, 88, a square wave is generated at each terminal station, and F
, signal, and F2 signal are generated, so the matching circuits 9A at both ends,
A coincidence output as shown appears at 9B, and when this is measured (integrated) by the integrating circuit 10, it reaches the slice level SL of the integrating circuit as shown at 10A and 10B, and the output circuit 1
An output is generated from 1A and 118, and this signal opens the breaker and eliminates the accident F. In Figure 2 C, the accident point is inside the protected area, as in Figure 2 b, but b
This is a case in which no fault current is supplied from the B terminal because there is no power source behind the electric station B at the variable power supply terminal (there is no generator 2).

Therefore, 6A and 8A are exactly the same as in figure b. However, since there is no B-end current at all as shown in 68, it is always below the LL level, and as shown in 8B, it becomes F2, a phase signal that allows continuous tripping, over the entire section. Therefore, the F2 signal of 8A appears as it is in the double-end coincidence circuits 9A and 98, and the 1
0A, 10B, 11A, 118 clearly generate the disconnection tripping signal. In other words, if the phase ratio shark relay is treated as a variable power supply terminal (LL level operation), the enemy level L
Since the F2 signal is generated with a current below L, it is possible to trip the breaker even if no fault current flows. Figures 3 and 4 are drawings for explaining the problems that led to the present invention, and among the constituent elements shown in the figures, the same components as in Figure 1 are denoted by the same reference numerals, and the drawings that appear below. I would like to clarify here that this idea will also be followed.

Reference numeral 16 is a line switch, which is installed on the line side of the disconnector at the B electric station, which is treated as a variable power supply terminal.

17 is also a line switch and is installed on the busbar side of the disconnector.

F is the internal accident point. In addition, Figure 4 shows the concept of the gap circuit of the phase ratio relay, in which 7-a is the output contact of the phase comparison relay 7, and 18 is the output contact of the undervoltage relay, which is not shown, to detect the system voltage. It is used as an input, and when a fault occurs in the grid, the grid voltage drops, so this is detected and activated to close the contact 18. When 19 is excited by the tripping coil of the breaker, the breaker opens.

It is a pallet switch with a 20' disconnector, and if the disconnector is turned on, it will open, and if it is open, it will be closed.

P, N' are DC operation buses. The following is clear from Figures 3 and 4. Now, in order to inspect the line breaker 4 at the variable power supply terminal B electric station, the line switches 16 and 17 installed on both sides of it are opened, and the line breaker 4 is turned on blankly.
At this time, it is common practice to turn on the power supply terminal A and the disconnector 4 to charge the power transmission line 5 from the power supply terminal. If an internal fault F occurs in the power transmission line 5 in this state, the line switch at the B electric station is open, so no fault current is supplied to the phase ratio shark relay, so the operation is exactly the same as in Fig. 2 C above. Accident F occurred when disconnection switch 4 at the A power plant was opened.
Of course, this would unnecessarily open the door and the disconnector being inspected, which would unnecessarily impede the inspection. This is clear from Figure 4, and from the explanation of Figure 2C, 7-a operates and the contact is closed, and although it is not shown in Figure 3, in reality, another power transmission line is connected in parallel to both A and B. Because the circuits are parallel to each other, if Accident F occurs, the undervoltage relay installed at Electrical Station B will be activated.
It goes without saying that this is a closed circuit. That is, since the phase ratio shark relay, which is treated as a variable power supply terminal, always outputs a trip-permitting phase signal when the current is zero, it will always operate if it receives a trip-permitting phase signal from the other end. Therefore, regardless of whether or not a trip is actually necessary, a trip signal will be issued as long as a voltage drop occurs at the same time. Therefore, one embodiment of the present invention will be described with reference to FIG. 5, and the effectiveness of the invention will be discussed.

FIG. 5 shows an embodiment of the automatic phase signal reversal control circuit for the phase ratio shark relay according to the present invention, in which 21 and 22 are normally open contacts of the auxiliary relay (not shown), and 21 is the normally open contact of the auxiliary relay, and 21 is the time when automatic inspection of the phase comparison general equipment is carried out. is a well-known configuration that closes the circuit and inverts the self-end phase signal of the phase ratio relay. P, represents a signal power supply. The gist of the present invention is to connect the contact 22 in parallel with 21 so that when the contact 22 is closed, the own phase signal of the phase ratio shark relay is inverted. Although the normally open contact 22 is not shown, it is a contact of a Tachibana relay that is energized when the line switch 16 or 17 is opened. In order to understand the effect of inverting the eye end phase signal when point 22 opens, some explanation will be given of the well-known automatic inspection that is performed when point 21 is closed after automatic inspection.

FIG. 6 is an explanatory diagram thereof, and reference numeral 8 indicates an output waveform 14 of the rectangular wave shaping circuit to the matching circuit 9, which is a received signal from the other end and an output waveform to the matching circuit 9. As explained in Figure 2, under normal power flow, the F2 signals of 8 and 14 do not overlap, and they are mutually F, , F2 signals.
Create two signals and send and receive them. 8' is the output waveform to 9 like 8, but when 21 is closed, voltage is applied from PT to the phase ratio shark relay 7 from Fig. 5. The normal phase signal at this end is inverted, and 8 and It will be the opposite.

Therefore, 21 has the same waveform as 8' and 8 before the circuit is opened. 9 to 11 are as explained in FIG.

In other words, as shown in Fig. 6, in the constant tide flow before 21 is closed, the F signals at both ends do not match and no output is output, but the automatic inspection command opens 21 and inverts the phase signal at the own end of the phase ratio shark relay. When voltage P is applied to the terminal, 8 is inverted as shown in 8', and since the F2 signal matches, an output appears in the matching circuit 9, and the operating output of the phase ratio shark relay is output from the output circuit of 11, and the phase ratio shark relay is activated. The soundness of the relay will be confirmed. The present invention applies a voltage to this self-end phase signal inversion input for automatic inspection to prevent an unnecessarily closed shear breaker from being unnecessarily disconnected due to an internal accident. In other words, when the line switch is open and the line breaker is idle, there is no need for the phase comparison carrier protector, which is treated as a variable power supply end, to operate, so the phase signal at the end of the line is zero current. As with the inspection, check that the phase signal is continuous F2.
In the machine, it is used as a phase signal to inhibit continuous F tripping.

Therefore, even if an internal accident occurs at this time and an F2 signal is transmitted from the other end, the own end will never operate because it is a continuous F signal.

In other words, according to the present invention, even if an internal accident occurs, there is no possibility that the disconnector will be unnecessarily disconnected due to a command from the protective relay system.

In this way, even if the phase signal is inverted and used only at the own end, the original phase signal 8 is sent to the other end regardless of this inverted phase signal 8', so when the other end is empty, the continuous F2 signal is sent to the other end. If an internal accident occurs, the phase ratio shark relay at the charging terminal A electric station shown in Fig. 3 will generate an F2 signal, so the accident can be reliably eliminated. According to the present invention described above,
Since the own end input of the phase ratio shark relay is the F signal, there is no need to react to an internal accident during one-end charging operation, and sudden opening during inspection can be completely prevented.

Since the brackets do not involve locking or opening the wiring, it is possible to inspect a wide range of systems, and there is no human error caused by rewiring. This effect of the present invention is achieved by applying an input signal that does not allow the phase ratio shark relay itself to operate, regardless of the so-called "Ock" operation.

[Brief explanation of drawings]

Figure 1 is a diagram explaining the principle of the phase comparison transport protection relay system, Figure 2
The figure is an explanatory diagram of the response under various conditions of the same method, 3rd to 4th.
FIG. 5 is a diagram illustrating problems in the follow-up system, FIG. 5 is a circuit for preventing blank closing and unnecessary disconnection according to the present invention, and FIG. 6 is a diagram illustrating automatic inspection of a phase ratio shark relay. Explanation of the symbols: 4...Shield breaker, 7...Phase ratio shark relay, 16, 17...Line switch, 22...Contact that closes when the line switch is connected. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] 1. When the current of the transmission line is detected for each phase at each terminal of the transmission line, and the current passing through the transmission line is considered to have the same polarity at each end, the phase comparison relay, which is treated as a power supply terminal, detects the current level above the specified current level. A phase comparison relay, which is treated as a variable power supply terminal, sends a phase signal to the other end that allows tripping during periods that do not include zero current and prohibits tripping during other periods. A phase signal for allowing tripping and prohibiting tripping for other periods is sent to the other end, and the relationship between the phase signal at the own end and the phase signal at the other end is determined to control the tripping at each end. In the phase comparison relay method, in which the open terminal of the disconnector sends a trip-permissible phase signal to the other end, the phase comparison relay, which is treated as a variable power supply terminal, is placed at its own end or on both sides of the disconnector. A phase comparison characterized by inverting the phase signal at the own end and using it as the phase signal at the own end on the condition that the line switch is opened, and transmitting a non-inverted phase signal to the power supply end. Transport protection relay system.