JPS6245484Y2 - - Google Patents

Description

[Detailed explanation of the idea]

[Industrial Application Field] This invention separates the fault section by preventing retransmission to the fault section, and also prevents three-phase short circuits and two-phase short circuits (both those occurring within the own line and those occurring between other lines). The present invention relates to an automatic high-voltage line breakage fault section automatic classification device that can accurately classify faults even if the fault current values differ, such as short-circuit faults. [Prior Art] As a conventional high-voltage line disconnection accident area automatic classification device, for example, the switch is locked (prohibited from closing) based on the second interruption of the substation that occurs when retransmission to the accident area. There is a system that separates the accident area. This high voltage line disconnection accident zone automatic classification device starts timing after detecting the presence of voltage on the power supply side, and when a predetermined time limit X has passed,
a first timer that outputs a time elapsed signal;
A closing means that closes the switch when a time elapsed signal is output, and a timer that starts timing at the same time as the switch is turned on and shuts off the substation before a predetermined time period Y (however, Y<X) elapses. Some devices are equipped with a second timer that prohibits the first timer from performing the next time counting operation when this happens. In this automatic sorting device, the time limit X is several seconds (recently
Although it has been shortened to about 1.5), it is set to a larger time. According to this automatic sorting device, when an accident occurs on a line, the substation shuts off the line, and when the substation retransmits the line, the switches are turned on one after another from the power source side. In the switch on the power supply side corresponding to the fault section, when a retransmission voltage appears on the power supply side, the first timer starts X time period, and after the X time period, the closing means closes the switch. Since this turn-on is the turn-on of the fault section, the substation shuts off again and the second timer prohibits the next timing operation of the first timer. Next, when power is transmitted again from the substation, the switches are turned on one after another from the power supply side, but since the first timer is prohibited from operating the first timer on the switch, the switches are not turned on. Locked. The accident category is classified by this operation, and if the prohibition of the first timer's timing operation is lifted (reset) after the accident is repaired, the switch will be turned on and power will be supplied, and the next It is possible to prepare for the classification operation of the accident section. [Problems that the invention aims to solve] However, according to the conventional high-voltage line disconnection accident section automatic classification device, after the power is retransmitted to the accident section, the accident section is divided by repeated transmission. is dangerous because voltage is applied to it, and
Since the substation shuts off twice, there is an inconvenience that it lacks promptness. Furthermore, because automatic classification control is performed based only on voltage elements, accidents such as three-phase short circuits and two-phase short circuits (occurring within the own line or between the own line and another line) are If they differ, there is a risk of malfunction and lack of accuracy. [Means for solving the problem] The present invention has been made in view of the above,
In order to prevent retransmission to the accident section, if an accident occurs during power-on operation or power supply, it will be memorized and the next power-on will be prohibited. The present invention provides an automatic high-voltage line breakage accident zone classification device that makes accident determination based on comparison reference values. [Embodiments] Hereinafter, the present invention will be described in detail based on preferred embodiments with reference to the accompanying drawings. FIG. 1 is an installation diagram of the device according to the present invention.
The distribution system, which is branched out from the substation SS,
Sections are divided based on the magnitude of the short-circuit current I _S (as shown by chain lines A, B, C, D, and E in the figure), and self-inspection (automatic classification) is carried out at points A, B, C, and D. equipment (abbreviated as “equipment”) will be installed. Then, the short-circuit current detection level for each self-inspection is set in stages.
For example, the self-inspection at point A is 5KA≧I _SO ≧2KA (however, I _SO is the set value, the same applies hereafter), the self-inspection at points B and C is 2KA≧I _SO ≧1KA, and the self-inspection at point D is
It is set so that 1KA≧I _SO ≧0.3KA. Assuming that a wire breakage accident occurs in the Harney section, a fault current of 1KA to 2KA will flow, and only the self-inspection at point B, which has a set value within that range, will detect the fault and store it. Then, after the circuit breaker of the substation SS is cut off by the disconnection relay, only the switch at point B is locked, and the distribution section after point B is controlled to be divided by the re-closing operation of the substation SS. Next, a self-inspection will be explained. FIG. 2 shows a schematic explanatory diagram thereof. A three-phase power distribution system is divided into an area close to the main transformer and an area other than the main transformer. The area is a protection means for the generator, including a transformer GPT for zero-sequence voltage detection and a current transformer for zero-sequence current detection.
It is equipped with a ZCT and a current transformer CT that detects the line current, and if an accident occurs on the load side, the circuit breaker CB will shut it off. Further, in the area, 1 is a switch, 2 is a fault section automatic detector, and 3 is a transformer. The fault section automatic detector 2 is given a signal from a current transformer for detecting short-circuit current built into the switch 1 and a distribution line voltage signal based on the transformer 3. 1 has a configuration that controls the operation of In addition, in order to simplify the explanation, the second
In the figure, the input given to the automatic fault section detector 2 is shown to be obtained from a single-phase distribution line, but in reality, each signal is simultaneously transmitted to the fault section automatic detector 2 from each three-phase line with the same configuration. is configured to be given to The automatic sorting device comprised of the automatic switch 1, automatic fault section detector 2, and transformer 3 will be explained in more detail in FIG. Switch 1 installed on the distribution line is a three-phase current transformer
BCT (current transformers BCT ₁ , BCT ₂ and BCT ₃ for each phase
) and a switching contact CC.
The current detected by the three-phase current transformer BCT is transferred to the zero-phase current rectifier circuit through the auxiliary current transformers Tr ₁ , Tr ₂ and Tr ₃ .
RE ₁ , and each phase current rectifier circuit RE ₂ , RE ₃ and RE ₄ is given. The output e ₁₀ of the rectifier circuit RE ₁ is passed through the setting circuit SE ₁ to the level detection circuits DE ₁ and DE ₂
and the output of the level detection circuit DE ₁
e ₂₆ is the AND circuit AND ₄ output e ₂₇ and OR circuit OR ₂
is given to. On the other hand, the output _e25 of the level detection circuit _DE2 is given to the AND circuit _AND4 together with the output _e23 of the OR circuit _OR1 , which will be described later. OR circuit OR ₁
After the current in each phase is rectified (rectifier circuits RE ₂ , RE ₃ and RE ₄ ), the currents in each phase are rectified (rectifier circuits RE ₂ , RE 3 and RE ₄ ) and then
Level detection circuits _{DE 3 ,} DE ₄ and
DE ₅ and the resulting outputs e ₁₄ , e ₁₅ and e ₁₆
The outputs e ₂₀ , e ₂₁ and e ₂₂ obtained from the logical operation are given. The logical operation of the above outputs e ₁₄ , e ₁₅ and e ₁₆ is performed using three inverters and three AND circuits.
This is performed using a logic circuit consisting of AND ₁ , AND ₂ , and AND ₃ . In other words, at the input of the AND circuit AND ₁ ,
The output e ₁₄ and the inverted outputs e ₁₅ and e ₁₆ are further provided to the AND circuit AND ₃ , and the output e ₁₆ and the inverted outputs e ₁₄ and e ₁₅ are respectively provided. The output e ₂₈ of the OR circuit OR ₂ becomes the input of the monostable multivibrator SS (which remains ``1'' for 1.5 seconds even after the output e <sub>28</sub> becomes ``0''), and its output e ₂₉ becomes the self-stable multivibrator SS, which will be described later. The output e ₃₁ of the voltage detection circuit of the faulty power supply and the output e ₃₂ of the AND circuit AND ₇ cause the keep relays K ₂ and K ₃ and the mechanical display means.
It has a configuration in which IND is driven. Then, the circuit of the indicator lamp _L2 is opened and closed by the a contact of the keep relay _K3 . Indicator lamp L ₂ is a keep relay
It lights up when _K3 is set and relay _R1 , which will be described later, is turned on. On the other hand, the output e ₁ or
e ₁ ' is connected to the logic circuit and switch 1 via switch SW ₁ .
It has a configuration in which the excitation coil CC, the no-voltage detection circuit, and the constant voltage circuit are respectively supplied. In the above logic circuit, the output e ₁ (or e ₁ ') is connected to the AND circuit AND ₆ via the b setting of keep relay K ₂ and the parallel circuit of the b contact of keep relay K ₁ , which will be described later.
Its output e ₄ becomes the input of timer X (output e ₄
starts the clock and outputs "1" after 14 seconds), and the output _e5 of timer X is
Input to OR circuit _OR3 . Output e ₆ of OR circuit OR ₃
becomes a drive signal for relay _R1 and timer Z (becomes "1" after driving and continues to be "1" for 2 seconds even if the power supply voltage disappears). Also, the output of timer
_e5 becomes a set signal for keep relay _K1 , and also sends a timer Y (outputs " ₁ " 12 seconds after being driven) via the a contact of keep relay K1.
It is used as a driving signal. The output _e8 of the timer Y serves as a reset signal for the keep relays _K1 , _K2 , _K3 and the mechanical display means IND. Note that the reset line is configured so that it can also be operated manually using switch _SW2 . switch
The output e ₁ (or e ₁ ′) obtained through SW ₁ is a rectifier circuit that has a branched configuration from the above logic circuit.
RE ₅ , smoothing circuit RE ₆ , no-voltage detection circuit DE ₆
and given to the constant voltage circuit ST. The output e ₃₀ of the no-voltage detection circuit DE ₆ drives a timer TA (which outputs "1" for one second after detecting no voltage), and its output e ₃₁ becomes the input of the AND circuit AND ₇ described above. In addition, each circuit for self-failure detection is driven by the output of the constant voltage circuit ST. Last but not least, to explain the configuration, power is supplied to the excitation coil CC of the switch via the output e ₁ selected by switch SW ₁ .
(or e ₁ ') is provided through the a contact of relay R ₁ . Next, with reference to FIG. 4, the operation of the apparatus having the configuration described above will be explained. Now, at time t ₀ (hereinafter, time will be simply indicated by a symbol), the switching contact CC
is in the open state (relay R ₁ is in the reset state), keep relays K ₁ , K ₂ , and K ₃ are in the reset state, the mechanical indicator IND is in the non-fault indicating state, and the three-phase power line is in the non-live state. , t ₁ , the three-phase power supply is in a live state and the distribution line is in a normal state. By the voltage _e1 applied via the switch _SW1 , the logic circuits below the AND circuit _AND6 perform the sequence operation shown in the figure _{from t1} to _t3 , and the self-fault detection enters the operating state. At this t ₂ , timer
Switching contact CC is closed based on "1" after 14 seconds and kept closed based on "1" of timer Z.
On the other hand, for the circuits after rectifier circuits RE ₁ to _{RE 4} that are input via the three-phase current transformer BCT, the distribution line is in a normal state, so the output of e ₂₈ is "0" and monostable multi The vibrator SS is not triggered, so the output e ₂₉ is "0" and is a keep relay.
K ₂ , K ₃ and the mechanical display means IND also maintain their initial states. At _t3 , when timer Y outputs "1", keep relay _K1 set by timer X is reset. Then, when a three-phase short circuit accident occurs at _t4 , _e14 to _e16 and _e24 to _e26 become "1", and the substation circuit breaker trips at _t5 . As a result of this trip, timer Z becomes "0" after 2 seconds, so relay _R1 is de-energized, thus opening/closing contact CC becomes open, and at the same time, no-voltage detection circuit DE ₆ outputs a no-voltage detection signal. When e ₃₀ is obtained, timer TA is driven, and even if no voltage is detected, "1" is output as signal e ₃₁ for one second. On the other hand, at _t4 , _{the output e28 of} the OR circuit _OR2 assumes the "1" state based on the output e26. And the output e ₂₈ of "1" state
Only the time period that is 1.5 seconds added to the "1" time period is "1".
becomes an AND circuit inputting signals e ₃₁ and e ₂₉
The output e ₃₂ of AND ₇ goes to the "1" state and sets the keep relays K ₂ , K ₃ and the mechanical indicator IND ₁ . This allows us to know that a short-circuit fault current flowed in the three-phase distribution line at _t5 . Two seconds after the substation has tripped and there is no voltage, timer Z reaches "0", and relay _R1 is reset and the switching contact CC is released. Next, at t ₇ , power is retransmitted from the substation. Even if power is retransmitted,
Since keep relay K ₂ has not yet been reset, the output e ₄ of AND circuit AND ₆ is in the "0" state. Therefore, timer X is not driven and relay R ₁ is not turned on, so switching contact CC There is no input. In other words, the self-inspection circuit prohibits (locks) the switching contact CC of the switch 1 from closing. Furthermore, when relay _R1 is turned off, lamp _L2 does not light up, and the mechanical display means IND merely assumes a display state. The following can be said from the above operation. Now, the fifth
If the self-inspection unit installed at points A and B as shown in A in the figure operates from t ₀ to t ₆ in Figure 4, then points A and B
The display for self-inspection at point A takes two different display formats as shown in Figure 5 B, and the short-circuit accident point can be known from the display formats (for self-inspection at point A, relay R When ₁ is turned on, both mechanical and lamp display states are set). Therefore, if the current fault point is the X mark in A, after the short-circuit fault point has been repaired, the keep relay can be turned on by turning on the manual reset switch _SW2 at _t7 .
When K ₁ , K ₂ , and K ₃ are unset, the display on the mechanical display means IND can also be switched to a non-accident display. This operation closes the switching contact CC. Next, the occurrence of a two-phase short circuit fault current will be explained. Assume that a two-phase short circuit fault (between the own circuit and another circuit) occurs at t ₁₀ , and the signals e ₂₄ and e ₁₄ are in the "1" state. Only the output e ₂₀ of the AND circuit AND ₁ is in the “1” state, and the AND circuit is passed through the OR circuit OR ₁ .
This becomes the input for AND ₄ . On the other hand, the output e ₂₄ of the output e ₂₅ is "1" based on the level of the level detection circuit DE ₂ .
state, and becomes the input to the AND circuit _AND4 . Therefore, the output e ₂₇ becomes "1" state, and the OR circuit
Trigger the monostable multivibrator SS via OR ₂ . The operations from t ₇ to _{t 9} and from t ₁₁ to _{t 13} can be understood in the same way as the occurrence of the three-phase short circuit accident. In the above embodiment, by setting the levels of each level detection circuit as follows, the protectable range can be determined as shown in FIG. In Figure 6, 3LG means a three-phase short circuit accident, and 2LG means a two-phase short circuit accident.By setting as follows, the output e ₂₀
~ Three-phase short circuit fault based on e ₂₂ and outputs e ₂₅ and e ₂₆ ,
Two-phase short circuit accidents (both within the own circuit and between the own circuit and other circuits) can be reliably detected. Level detection circuit DE ₁ ... Setting value x √3 Level detection circuit DE ₂ ...

[Formula] Level detection circuit DE ₃ , DE ₄ , DE ₅ ...

[Formula] Next, the switch 1 used in the above embodiment will be explained. In FIG. 7, the overall view of the switch 1 is
In FIG. 9, conceptual diagrams are shown. In Fig. 7, 11 is a bushing, 12 is a fixed insulator, 13 is an arc extinguishing chamber, 14 is a movable conductor, and 15 is a
is a rotary insulator, and 16 is a three-phase current transformer (see Figure 3).
BCT), 17 is a hanger hook. Also, according to FIG. 9, a three-phase current transformer 16 is attached to the bushing 11.
I can understand that it is installed. The external shape (partially cut away) of the three-phase current transformer 16 can be seen in FIG. This is a through-type current transformer provided with an annular line through-hole 161, and the three phases are integrally constructed using epoxy resin. 162 is its leader line. A cavity 166 is formed around the penetration part 161, and an iron core 163 is inserted into a part of the cavity with a spacer 165 interposed therebetween.
4 is wound. Such a three-phase current transformer 16
is built into the switch 1. FIG. 10 shows the characteristics of the three-phase current transformer 16. The temporary current/output voltage characteristic is obtained as a substantially straight line because no saturation phenomenon is observed due to its configuration. Therefore, it is extremely convenient for the output of the three-phase current transformer 16 to be treated as an input signal for the self-failure test of the present invention, which operates based on a predetermined set value, and malfunctions can be prevented. As explained above in detail, according to the device of the present invention, when an accident occurs during power-on operation or power supply, it is memorized and prohibits the next power-on, and it also uses a comparison standard according to the nature of the accident. Since the accident is determined based on the value, it is possible to reliably detect an accident and prevent retransmission of the accident section. The present invention is not limited to the above-described embodiments, and various other modifications and variations can be made by those skilled in the art. It should be understood that the present invention includes such modifications within the scope of the utility model registration claims.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the installation of the high-voltage line disconnection accident zone automatic classification device according to the present invention. FIG. 2 is a schematic explanatory diagram of the automatic high-voltage line disconnection accident zone classification device according to the present invention. FIG. 3 is an explanatory diagram of the configuration of the automatic high-voltage line breakage area classification device according to the present invention. Figure 4 is a time chart for operation. 5 and 6 are explanatory diagrams showing the display state and application range of the high-voltage line breakage accident zone automatic classification device according to the present invention. Figure 7 is an external view (partially cut away) of the switch. Figure 8 is an external view (partially cut away) of a three-phase current transformer built into the switch. FIG. 9 is an explanatory diagram of the configuration of the switch. Figure 10 is an electrical characteristic diagram of a three-phase current transformer. Explanation of symbols, 1... Switch, 11... Bushing,
12... Fixed insulator, 13... Arc extinguishing chamber, 14... Movable conductor, 15... Rotating insulator, 16... Three-phase current transformer, 17...
Hanger hook, 161... Penetration part, 162... Leading wire, 163... Iron core, 164... Coil, 165...
Spacer, 166...Cavity part, 2...Fault section automatic detector, 3...Transformer, BCT...Three-phase current transformer, CC...Switching contact, Tr ₁ , Tr ₂ , Tr ₃ ...Auxiliary current transformer, RE ₁ ，
RE ₂ , RE ₃ , RE ₄ , RE ₅ ... Rectifier circuit, RE ₆ ... Smoothing circuit, SE ₁ , SE ₂ , SE ₃ , SE ₄ ... Setting circuit, DE ₁ ,
DE ₂ , DE ₃ , DE ₄ , DE ₅ ...Level detection circuit, DE ₆
…No-voltage detection circuit, AND ₁ , AND ₂ , AND ₃ ,
AND ₄ , AND ₅ , AND ₆ , AND ₇ ...AND circuit,
OR ₁ , OR ₂ , OR ₃ …OR circuit, SS…monostable multivibrator, K ₁ , K ₂ , K ₃ …keep relay, R ₁
...Relay, L ₁ ...Mechanical display means, X, Y, Z,
TA...Timer, L ₂ ...Display lamp, ST...Constant voltage circuit.

Claims (1)

[Claims for Utility Model Registration] (1) A first timer that generates a switch closing signal when a first predetermined time period is counted after detecting line voltage; a first storage means for storing the output of the switch closing signal and prohibiting the first timer from detecting the line voltage; current detection means that generates a fault current signal when a predetermined value is reached; voltage detection means that detects line voltage and generates a trip signal when it is determined that the substation has tripped; and the fault current signal and the trip. a second storage means for storing the detected occurrence of an accident on the load side based on a signal and prohibiting the first time-measuring means from detecting the line voltage; and the first time-measuring means; a second predetermined time period that is shorter than the first predetermined time period after generating the switch closing signal and generates a release signal for releasing the prohibited operation of the first and second storage means; a third timer for continuing to generate the switch closing signal until the substation trips when the first timing means generates the switch closing signal; the first and second storage means are provided with switching means for closing the switch based on the signal and opening the switch when the switch closing signal is not present; A high-voltage line breakage accident zone automatic classification device characterized by prohibiting the closing of a switch by a prohibited operation. (2) The automatic high-voltage line disconnection accident section according to claim 1, wherein the current transformation means has a gap in a part of the magnetic path and does not exhibit magnetic saturation in the range of operating current levels. Sorting device.