JPS5846836A - Network protector - 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 relates to a protector and interrupter tripping device.
When the protector and interrupter in the network power distribution equipment generates reverse power due to the power generation action of the load, there was no interruption, and even while the load was generating reverse power, a ground fault occurred in the primary feeder line and reverse power was generated from the network bus. in case of,
The present invention relates to a network protector equipped with a faulty line detection circuit that detects this and trips a protector circuit breaker.

What is important when supplying power to a power distribution system is to supply power with stable voltage and frequency without power outages. One of the countermeasures against this problem is a network power distribution device.

This network power distribution equipment connects the primary distribution feeder line to two
In addition to the above, each feeder line is connected in parallel to the network bus or cable via a power receiving disconnector, network transformer, and protection device.This protection device is called a network protector and is connected in parallel to the network In the event of an accident on the Okinawa electric line, the power supply to the faulty electric line will be supplied from other full-circle electric lines via the network circuit #1]
It has a function to quickly remove the reverse power (so-called reverse power interruption). In addition, network power distribution equipment flK
There are Ray, Lane, Twork power distribution equipment, Su4tnet, and Towork power distribution equipment.

Although the present AA network power distribution device is generally applicable, for convenience of explanation below, 4. Tone.

A converter power distribution device will be explained as an example.

Part 1 II shows a schematic connection diagram of a S/Y tone and twin power distribution device in which the primary feeder is a triple feeder. In the figure, power supply substation 8B mustard interrupter Cll1l*-CB
The power receiving route device D S g -D8m network water f ■ Tector NW-Pr.1...NW.Pr@- is connected to the primary feeder wires PI and 1-PL through 02nd Confucianism NW * Prow...M
The W-Prey iJi line and the talk bus NW-BK are connected in parallel, and are connected to each load (not shown) via a take-off device T OI . . . Te3. The reverse power and interruption functions of the network protector have been described above, and the details of these functions and other functions are as follows.

(1) In the case of a short circuit accident in the primary feeder wire.

After the substation interrupter is tripped, fault current from the network circuit is detected and the interrupter is tripped.

(2) In the case of a ground fault in the primary feeder line. 'After the substation interrupter is tripped, the current that is the vector sum of the transformer excitation current and wire charging current from the network circuit is detected and protected, and the interrupter is tripped.

(3) When the primary feeder line is charged and the network circuit is without voltage.

The protector interrupter is turned on without voltage.

(4) When the network circuit side is charged and any protector or interrupter is tripped.

In this case, the difference between the voltage on the primary feeder side and the voltage on the network circuit side and the phase difference between both voltages are detected, and when the conditions are met, the Kf protector interrupter is turned on again. (Differential Voltage Application) FIG. 2(a) is a schematic single connection diagram of the network protector. In the figure, connected to the secondary side of the network transformer NW-Tr,
-jePro-F, protector and interrupter Pre -CB
and relay devices NW-RF and K. Relay device NW-R7 includes power direction relay #1 and phase relay 11.
, a current transformer for obtaining these operating inputs, and an auxiliary transformer PT, etc., as necessary.

2nd g) shows a control circuit for tripping or closing the protector and interrupter Pr...CB by the output of the relay Nw-nyi.

Figure 2 (a), (b) With KsP, the power direction relay #1 determines the direction of power flowing into the main circuit, reverses power, and protects the contact output of interruption or restart (no voltage, differential voltage). The disconnection coil ↑cTo or the input coil CCVC of the interrupter Pro-CB is provided. The phase relay 2a functions only in the case of reinsertion, and determines the phase relationship between the no-load voltage on the transformer secondary side and the network bus side voltage, and connects the rectangular power direction relay d to its contact point.
It is connected in series with the re-closing contact output 62c of No. 1 to provide the closing coil CCK. Therefore, unless the re-closing contact output gyc of the power direction relay 67 is given to the closing coil ccK, and the contact output of the phase relay IJ is not given, the closing coil cc cannot be energized, and the protector and interrupter P
ro・CB will not be reintroduced.

In this case, if we consider the reverse power and interruption of the talk f protector, the conditions for the interruption are a large current reverse power such as a short-circuit accident in the primary feeder wire, and a no-voltage condition in the primary feeder wire. There are cases where the reverse power is a minute current such as the vector sum of the charging current of the primary wire and the excitation current of the transformer, and extremely high sensitivity is required.

Furthermore, if the other loads in this system are light, for example, if the network load is a load that performs regenerative braking such as an elevator, the network mains voltage may be reduced for a short time, but the primary power line [voltage] can be high. Due to this, a phenomenon occurs in which power is sent backwards from the 1 network bus side to the primary feeder line, and even though the primary feeder line is normal, the power direction relay is highly sensitive, but If the power is detected, the protector is turned on, and a 1-removal command is given to the interrupter, it becomes K.

However, since the reverse power line disappears in a short time due to regenerative braking, the relay main current is immediately protected and a closing command is given to the intermediate unit to perform an unnecessary interruption and restart operation. Furthermore, in this case, all the network protectors supplying power must be operating, and the rounded network busbars must be expanded without voltage, which is consistent with the purpose of the network power distribution equipment, assuming uninterruptible supply. 1 I/%.

Therefore, in order to avoid such unnecessary operations, conventional methods have been proposed, for example, in Japanese Utility Model Publication No. 51-49561 and Japanese Patent Publication No. 51-49561.
As shown in Publication No. 2-33294, when the reverse power exceeds a certain value, the protector is instantaneously removed and the interrupter is removed, and when the reverse power is less than a certain value, reverse power due to Ka regenerative braking is generated on all lines. Taking advantage of this fact, when the power direction relays of all the lines are protectors and a 1-removal command is given to the interrupters, all the protector circuit breakers are prevented from being 1-removed.

However, let us now consider a case where a ground fault occurs in the primary feeder line while reverse power is being generated due to regenerative braking. In this case, the protective device at the outlet of the primary feeder line at the substation will turn over to the power source in a few seconds, remove the interrupter, and stop the power supply to the point of the ground fault/fault.

Roughly speaking, a current equal to the vector sum of the transformer excitation current and the wire charging current flows through the line where the ground fault occurred, but reverse power is generated due to regenerative power.

In the conventional system, as mentioned above, when reverse power is generated in all lines, the protector and interrupter are not removed, so in this case, the line where the fault occurred is not disconnected and the fault current continues to flow. [I will continue], if the original function of the talk ftx protector is impaired.

In order to eliminate the above-mentioned drawbacks, the present invention company has developed
Therefore, even if a ground fault occurs during the generation of regenerative power, the purpose of this is to ensure that the fault current flowing back from the network bundle can be promptly interrupted. There are many ways to provide network protectors.

First, an overview of the present invention will be described. If only regenerative power is used for an elevator or the like, a reverse current due to the regenerative power is divided into each line, so the current flows with exactly the same amplitude and phase.

On the other hand, if a ground fault occurs, the transformer excitation current flowing through the fault line Krl1, the vector sum of the feeder line charging current, and the regenerative power will be used to restore the system to normal operation. The current flowing through the circuit is a current with a different amplitude and phase. However, in the other healthy cycles 1IIK, a reverse current due to regenerative power flows, so a current with the same amplitude and phase flows. The present invention utilizes this power to distinguish between the two, and even if a ground fault occurs during the generation of regenerative power, the fault current flowing backwards from the net lark motherboard is immediately removed and interrupted. .

An embodiment of the present invention will be described below with reference to the drawings. Fig. 3 shows an example of the configuration of the twerk zoro protector in the network power distribution device according to the present invention, and the same parts as in Fig. 1.2 are given the same reference numerals and their explanations are omitted. . Note that FIG. 3 shows a case where one network group is composed of three lines, and ÷1°φ2 and φ3 are the first and second lines, respectively. These are the second and third lines. In the figure, l represents a faulty line detection circuit, which is composed of, for example, a digital circuit. Jawjb, 1@ is a current transformer provided in each line, and Ja+zb+J@ is a signal line for receiving a protector/interrupter side disconnection command of each line to the failed line detection circuit IK.

FIG. 4 shows a flowchart for explaining the operation of the failed line detection circuit 1. As shown in FIG. Figure 5 shows the tripping circuit of the protector and interrupter, so 4 is the Hatake contact of the power direction relay AT of the network relay, and 5 is the B contact that is energized by the output of the fault line detection circuit 1. be.

With such a configuration KsP, if the voltage of the network bus NW-1 becomes higher than the voltage of the primary feeders 11pLl, PL, and PL because the load KL in FIG. 3 generates regenerative power, The network fa techa NW-Pro s, NW-Pro 嘗 and NW-
Power is sent back to the primary feeder line via Pr.l. For this reason, when each circuit is connected, the reverse power is applied to the power supply and the interrupt function is used to issue a command to 1) remove the protector from the interrupter side. In 818P&, la, lb, l. are contacts 5a in FIG.

J b e l @, the contact Sha1m is opened, but the contact 5a is closed. Here, contact 4h*4
b, 4. is a circle where reverse power is generated in all lines,
Since all are already closed, protect and interrupter P
Only r...CB is tripped and the fault line +1 line is disconnected.

In addition, if a ground fault occurs in the +2 line, 8TEP J → 5TEP 2 → 5TEP 3 → 5 in Figure 4
Proceed to TEP 4. In this case, the amplitude value of the current flowing in the +2 line, which is the fault line, is different from the amplitude value of the current due to regenerative power flowing in the +3 line, so 8TEP 4→5TE
Proceed with P#. On the other hand, +1 line and +3 line both have the same amplitude value of current due to regenerative power, so 8TEP 6
→Proceed to 8TEP 9. 5TEP9 l * @ l
b * S e indicates the contacts Sh+Sb, S in Fig. 5.
t, the contacts 5 m and 5e are opened, but the contact 5b is closed. Then, as in the case where a ground fault occurs in one line, only the protector and interrupter Pro-CB* is tripped.

Furthermore, if a ground fault occurs in the +3 line, only the protector breaker Pro-CBs is tripped in the same way.

In this way, the power direction relay 61 that determines the power direction and responds by determining the power direction is installed in the twerk detector NW Pro for multiple lines connecting the primary feeder line and the secondary power distribution system, and When any of the power directional relays operates, the protector and interrupter Pr...cm corresponding to that power directional relay is immediately tripped. 1 Calculate and compare the amplitude values of the currents flowing in each of the lines above, and if the amplitude values of the currents in all lines are equal, all protectors and interrupters should be tripped. Also, if the amplitude value of the current on one line is different from the amplitude value on another line, the function is to protect the wrinkled line and trip only the interrupter, and protect the other OII lines and prevent the tripping of the interrupter. The circuit is equipped with a faulty line detection circuit having a faulty line detection circuit and constitutes a network protection for the faulty line detection circuit material.

Therefore, even if a load that generates power, such as an elevator, is installed, it is possible to prevent a total power outage across one network group, as well as prevent a power outage from occurring in the primary feeder line during regenerative power generation. A ground fault can be immediately detected and disconnected from the network system, and the original network If protector function can be fully fulfilled.

By the way, in the above embodiment, the fault line is detected each time II
By comparing the amplitude values of the currents flowing through K,
However, when the regenerated power is extremely small, the current shunted to the healthy line will be extremely small, and it may be difficult to distinguish it from the fault current. However, the difference between the transformer excitation current flowing in the fault line and the feeding line charging current)
The phase of the sum of the current and the current that is shunted to the healthy line due to regenerative power is significantly different, so there is a method of comparing both the current value and phase of each line to detect a faulty line. By using K, faulty lines can be detected more accurately.

Below, FIG. 3 shows an example of such a case.

This will be explained using FIGS. 5 and 6. Fig. 6 11□1 shows the operation of the faulty line detection circuit 1 of Fig. 3 when detecting a faulty line by comparing the amplitude value and phase of the current.
- Chart diagram. .

Regenerative power is generated from the load KL in Figure 83, and each time I
If reverse transfer of Ik power occurs, the network protectors Nw-Pr·t, NW·Pro! and NW-
pro is a reverse power interrupter (with reverse power interrupter function), fvx protector interrupter Pro-CBhPr.

Issue a tripping command to CB and Pro CB.

The operation of the failed line detection circuit 1 in this case will be explained using FIG. 6. First, in 8TEP1, each line C)fa is checked and an interrupter tripping command is sent. Next, sT Goose P
1) From all lines, 1) F stomach protector and interrupter tripping command force! 11 because it's out? Proceed to IP J. In gTEP J, the current of each am is taken from the current transformer I in FIG. 3 and the amplitude value of the current is determined. Also, in 8'rlP4, calculate the phase difference of the current between each line using the current of each line taken in from the current transformer. In steps 1TIP j to 8TIP 1e, the amplitude values of the currents of each line are compared, and a determination is made by checking whether the phases of the lines are equal. In this case, since only the regenerated power is used, the amplitude value of the current for each circuit is the same, and the phase 4 of each circuit is the same, and the phase difference between the circuits is zero. Therefore, 5TEP j → 5TEP 6 → 5TEP
Proceed as 7→8TEP J→5TEP 11. 5TEP
5 hours at 11.

5b, l@ are the contact points 5m, 5 in Figure 5.
b.

5c, 5TEP J J, contact 5m, 5b
.

5@ are all opened, so all protectors and interrupters are not tripped.

However, while the regenerative power is being generated, the primary feeder line P in Figure 3
If a ground fault F1 occurs in L1, a current equal to the vector sum of the transformer excitation current and the wire charging current flows from the network bus NW-B to the fault line. In this case, the current flowing through the ÷1 line is different from the current that is shunted into the ÷2 and φ3 lines due to regenerative power, at least in either the amplitude value or the phase of the current, so the flowchart in Figure 4 is In the diagram, 8TEP 1→5TEP J→5TEP s→5TEP
It progresses as 4→5TEP 5→5TEP #→8TEP y, and if the amplitude value of the current of the φ1 line is different from the amplitude value of the current of the other lines, it progresses as 8TEP F→8TEP 12. The operation of the failed line detection circuit 1 in this case will be explained using the fourth P. First, g'rgp 1 is used as an f-tector for each line from signal line 1 in FIG. 3 to issue a command to trip the interrupter. Next K s
Use BTEP J to protect all lines and check whether interrupter trip commands have been issued. In this case,
For all network protectors, proceed to Round 8 TIP J where the f a protector is issued and the interrupter tripping command is issued. 8
In TIP J, take in the current of each line from current transformer 2 in Figure 3 and find the amplitude value of the current, gTIPJ → 8TE1' 4
and proceed. Next, in 8T] CP 4-4 MP#, the current amplitude values of each line are compared and a determination is made. In this case, since it is only regenerative power, the amplitude value of the current in each line is the same, so 8TIP 4→5TEP 1→8〒gp
Proceed with r.

The 1m, lb, l* in g'rzp y refers to the contacts 1g, lb, l・ in Figure 5, and 5TEP F contacts 1m, 1b, l・ are all opened, so all protectors are interrupted. The device will not be removed.

However, if it is assumed that the ground fault of the primary feeder line PLtK in Fig. 3 occurs during the generation of %At regenerative power, then - when the transformer excitation current from the network bus NW-1 is the vector sum of the wire charging current, When the current flows backward, the network protector NW-Pros of the +1 line receives reverse power, protects it with the interrupt function, and issues a command to trip the interrupter. However, +1
Since a fault current that is different from the current in the φ2 and +3 lines flows through the line, in the flow diagram of Figure 4, 8TEP J → 5T
The process proceeds as follows: EP j -> 5 TEP 3 -> 5 TEP 4 -> 5 TEP 5, and at 8 TEP j, since the amplitude values of the currents of the +1 line and +2 line are different, the process proceeds to 5 TEP j. In the unlikely event that the current amplitude values of the +1 line and other lines are the same, 5 TEP
7-+ 5TEP a, but at the 9th point there is a phase difference between the currents of the +1 line and other healthy lines 8TKP j
→5TEP 12 and forward, 5TEPZj is 51°J
b * 8 @ indicates contact points 5 m and 5 in Fig. 5.
Since reverse power is generated in all the lines, the be contacts 4 are all already closed, so only the protector and interrupter PromCB1 is tripped, and the Φ1 line, which is the fault line, is disconnected.

On the other hand, if a ground fault occurs in the Φ1 and +3 lines,
, similarly K 5tzp s ~5rzp J o te'a
Separate and proceed to 8T Tobi pH and 8TWP 14, and disconnect only the fault line at the contact point 5m151)*5 in Figure 5.
Can be opened and closed.

In addition, the present invention can be modified and implemented in various ways without changing the gist thereof.

As explained above, according to the present invention, even if a ground fault occurs during the generation of homogeneous power, the fault current flowing backward from the network bus can be quickly ensured and interrupted, resulting in extremely high reliability. Ne, we can provide you with the information you need.

[Brief explanation of the drawing]

Figure 1 shows step 4. A schematic wiring diagram showing the network power distribution equipment, Figure 2 (a) and Figure 2) is a network diagram showing the network power distribution equipment.
The schematic diagrams and diagrams showing the control circuit of the protector and interrupter, FIGS. A block diagram showing an embodiment of the present invention in a network power distribution device, a 70-chart diagram explaining the operation of the faulty line detection circuit in FIG. A flowchart explaining the operation of the faulty circuit shown in FIG. 3 in another embodiment of the invention and a circuit diagram for tripping the protector and interrupter, and FIG. 6 shows the faulty line detection circuit shown in FIG. 3 in another embodiment of the invention. FIG. 2 is a flowchart diagram explaining the operation of FIG. 〆NW-Pro...Network protector, Pr.・CS-...protector and interrupter, NW-1...ne. network busbar, TC...protector breaker side outside□, rainbow coil, 61...power direction relay, 1...fault line detection circuit, 2...current transformer, 3...signal line. Applicant's agent Patent attorney Takeshi Suzue Hikoga 1vlI Fang 2 (a) (b) 4B 5th grade

Claims (2)

[Claims] (1) A power direction relay that determines the power direction and responds by determining the power direction is installed in the network protector for multiple lines connecting the primary feeder line and the secondary distribution system, and any power direction relay of the line in the operating state IIc is installed. If the power directional relay is operated, the protector and interrupter corresponding to the power directional relay are tripped, and each of the above-mentioned The amplitude values of the currents flowing through the lines are calculated and compared, and if the amplitude values of the currents in all lines are equal, all f protectors are prevented from tripping, and the amplitude value of the current in a certain line is is different from the current °amplitude value of another line, the f of that line
1. A network f-tector, characterized in that it is equipped with a faulty equipment detection circuit having a function of protecting and tripping only the interrupter and protecting other lines and preventing the interrupter from being tripped. (2) Connect the primary feeder line to the secondary distribution system multiple times. A power direction relay that determines the power direction and does not respond is installed in the rotator, and when any neo power direction relay in operating state 11 is activated, the fν detector interrupter corresponding to that power direction relay is tripped. Even if OK>h, the protector corresponding to the operating condition is set to trip the relay, and in a good condition, each circuit is connected on the condition that all the directional relays of am in operating condition 11 are operated. Calculate and compare the amplitude values and phases of the currents flowing through the lines, and if the amplitude values and phases of the currents in all lines are the same, all f protectors and interrupters are prevented from tripping, and If the amplitude value or phase of the current is different from the voltage width value or phase of another line,
A talk fws protector is equipped with a fault line detection circuit which has a function of tripping only the interrupter and preventing the interrupter from being tripped.