JPS5886824A - Bus protecting relay unit - 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 preventing malfunctions in front of a busbar protection relay device that protects a plurality of busbars connected to a power transmission line via a disconnector.

A conventional device of this type is shown in FIG. In the figure, (1) and (2) are the busbars to be protected, and (8
-1) ~ (8n) p - (4t) ~ (4-ω is the first and second disconnector m (n is a natural number), (8-1
a) ~ (anaL (4-1a) ~ (47na) are disconnectors ω-1) ~ <5-n) e (4-1) ~ (4- are busbars (11 or (2) ) side, (6) is the - bus connection line connecting bus bars (1) and (2), (7-1) ~ (7-n) e (8-
1) The c8-net (9-1) to (9-2) is attached to the power transmission line (5-1) to (5-n) or the bus connection line (6) (current transformer for deriving the current, QO is bus line (1)
.

(2) is a busbar protection relay device that protects each busbar (2) and is constructed as follows. 01), Q]) is a collective differential relay (
Hereinafter, this will be referred to as a batch relay. ), (2) is the bus line (1),
g4 is the first step that selects and detects each fault in mother & (2).
and a second selective differential relay (hereinafter referred to as a selective relay) (18+) to (18n) *Q4 represents each of the current transformers (8-1) to (8-n) e(9-1). A current proportional to the secondary/first current is derived and the first selection relay 0
(281) to (28n)
) # e14 is a transformation device (8-1) ~ (8-n),
(9-2) The second input device derives a current proportional to each secondary current and applies it to the second 5 selection relay (2). 1), which is connected to the differential input circuit in the first selection relay (6).

α6-1) is the first suppression output circuit built in the first input device (18-1), and the suppression device [(18-1)γ(18-1) in the first selection relay (2) n) *Q4 (28-
1) to (28-n), @4 are all input values! (18-
It has the same configuration as 1). 05 is the differential circuit line of the first selection relay (6), α is also the suppression circuit line,
- Outputs of (18-1) to (18-n) of the first input devices are connected in parallel via auxiliary relay contacts (8-1a) to (3-na) to the first selection relay. (2), and the output of Q→ of the first input devices is directly input to the first selection relay (2). Ambiguous.

) is the differential circuit line of the second selection relay (2), the suppression circuit line is the first selection, and the differential circuit line αG of the relay (6).
.

The connection is similar to that of the suppression circuit line αQ. (80-
1) to ω0-, 6υ is a breaker that is opened when a failure occurs inside the bus bars (1) and (2) to protect the bus bars.

Next, the operation of the conventional bus protection line device shown in FIG. 1 will be explained.

The collective current transformer (9-i), (
Current transformers (7-1) to (7-n) of all power transmission lines missing 9-2)
) are connected in parallel, and the relay operates if the combined value exceeds a certain value. For example, a relay of the current difference ζb type, which responds to the difference between the inflow and outflow currents, is used.

This batch relay 01), guυ, is a current transformer (7-1) ~ (
7-n) to detect a fault inside the bus, but the current transformer (9-1) or (9-n) of the bus connection line (6)
Since the output current of 2) is not introduced, there is no ability to determine whether the failure is in the bus (1) or (2).

Therefore, a relay for selecting a faulty bus is provided and is called a selection relay.

The first selection relay @ is configured to selectively detect a failure in the first bus (1), and the second selection relay (2) is configured to selectively detect a failure in the second bus (2). That is, inputs to the first selection relay (b) are from the current transformer of the power transmission line connected to the first bus side, the current transformer (9-1) of the bus connecting line (6), and the current transformer (9-1) of the power transmission line connected to the first bus side. The inputs of the selection relay 2 are the current transformer of the power transmission line connected to the bus (2) side and the bus connection line (6).
), the combined value is introduced according to the currents derived from each of the transformers (9x2).

For example, when the power transmission line (5-1) is connected to the first bus bar (1), the disconnector (8-1) is closed and (4-1 is opened, so the auxiliary relay Contact ω-1a) is closed, contact (4-1a) is open, and the secondary current of the current transformer (s-t) is transferred to the first selection relay @ via the first input device (18-1). A second selection relay (2) is introduced.
It will not be introduced.

In this way, when the transmission line is connected to the first bus (1) by the first disconnector N (8-1) to (8-n), the transformed 52nd order current of each power transmission line is First selection relay (
6), and the power transmission line is connected to the second disconnector group (4-1) ~
(4-n) when connected to the second bus bar (2), it is switched to be introduced into the second selection relay block. In addition, since the busbar connection wire (6) is fixed to the busbars (1) and (2), the secondary current of the back (s +) p (92) remains unchanged regardless of the disconnector opening/closing conditions. The input values @(14) and (c) will be introduced into the selection relays 0 and 0, respectively.
The selection relay ca*@ protects each mother frost by performing differential protection using as input the first current derived from the transmission 1d line connected to the bus to be selectively protected and the bus connection line (6).

In the example shown in Fig. 1, a ratio differential relay is used for the selection relay (2), @, so the input devices for each feed ° and β line are
Differential output circuit (15-1) and suppression output circuit (16-1)
are provided for each.

Since the conventional selection releni is configured as above,
If a special busbar configuration is used, malfunctions may occur due to external failures, so the countermeasures are as described above.

A separate bulk relay, etc. had to be installed.

FIG. 2 shows an example where the selection relay malfunctions. - The figure shows that bus bars (1) and (2) are short-circuited (hereinafter referred to as
This state is called a bridge. ), now the disconnector ω2) is closed and (4-) is open. In this case, the fault is outside the busbars (1) and (2), so the selection relay Q2. ) should not work.

However, [fault 1st flow I that flowed from the source cycle @(5-t)]
l+1. is the current 11 passing through the disconnector (8-, (4-2))
And bus line contact! After the current passing through (6) is divided into ■2, it is connected again to the disconnector (4-8) and the faulty
．． However, the leakage is 1. +12 input direction, current transformer (8-8)
is 11+1. The outflow direction of the current transformer (9-Ll) is the outflow direction of 12, and the inflow direction of the current transformer ω-2) and 6512. Therefore, if the inflow direction of the current is represented by + and the outflow direction is represented by -,
The secondary core current of each current transformer (, 1 current transformer (S-t) is +Gl
+12) s current transformer (8-8) or -(il +iz
), current transformation '4 (9-1) is -iz * r" flow Fa
(92) becomes +12. On the other hand, the auxiliary relay contact (8
Since the states of -1a) to (8-8ω, (4-1a) to (4-8a) are the same as the open/closed state of the grid disconnector,
For the 4th wire (5-1), the auxiliary relay contact (a-1a) is closed because the disconnector (8-1) is closed and (4-1) is opened.
The circuit is closed, (4-1a) is open, and the disconnector (8-2) is closed for power transmission Mω-, (4-2) is closed, so the auxiliary relay contact (8-2a) is closed, (4-2a) ) is closed, and the transmission line (5-8) is disconnected'', JJω-8)
Open circuit, (4-8) closed circuit, auxiliary relay contact ω-8a
) open circuit, (4-8a) closed circuit. Note that the output of the input device is proportional to the current transformer secondary current, and when the polarity is matched, the output of the input device is proportional to the current transformer secondary current.
1), , (1a-a) Output composite value 10(t
o (+(ilo 112o) 10-1zo ”'+
a value proportional to ito i it] is applied to the second selection relay (2) via the second input device Gl! 8-2
)# (28-a), H output composite value -1to(0(i
to+im)+i+=a value proportional to jtoilt) will be applied, and this differential current causes the selection relays @ and @ to malfunction.

As explained above, in the case of a bus bridge, using only a selection relay has the disadvantage of malfunctioning, and this is the first countermeasure.
As shown in the figure, it was necessary to provide a collective i/-aυ and υ to detect the combined value of the currents derived from all the power transmission lines, and to incorporate this into the new shutdown conditions. In other words, the corresponding busbar is protected only when one of the selected relays and the collective j relay operate together.

Bulk L'-([1), #D te wire (5-1) ~ (
5-n) Input all of the currents output from Color 4, calculate the difference between the currents flowing into and out of the bus bars (1) and (2) from the combined value, and operate when this is greater than the set value. It's a relay. Therefore, in the case shown in Figure 2, the inputs to collective relay 01) and @ are + (il+iz) from the power transmission line (5-1) and -(11+12) from the power transmission line (5-8). Since the composite value is zero, it does not work.

As described above, the conventional busbar protection relay device had the disadvantage that it was required to be provided with a differential relay/cell all at once in order to prevent malfunctions, so the structure was made later and was expensive.

This invention was made in order to eliminate the drawbacks of the conventional ones as described above, and it provides a bus protection relay device that does not malfunction even if the bus bars are short-circuited by a disconnector, by providing a collective differential relay. The purpose is to provide a simple configuration at low cost. In order to achieve this object, the present invention cuts off the current drawn from the busbar connecting wire (6) so that it is not input to the selective differential relay when the busbars are short-circuited by the disconnector, and all transmission lines 111 (
5-t) to (5-n) (by switching such that the current is input to the selective differential relay, the selective differential relay is made to function as a lump differential relay that protects the entire plurality of buses. That's what I do.

An embodiment of the present invention is shown in FIGS. 8 and 4 below.

and FIG. 5 will be explained.

When the busbars (1) and (2) are short-circuited due to a fault in the disconnector, the contacts (17b) and (27b) in Fig. 8 are opened, and the contacts (181a) and (182aL (188
a), (281a)t (282aL is interrupted 1, and all power transmission @ (5-1), (5-, 1 flow derived from (5-8) is sent to selection relay a, (2) The selection relay @, ′@ will be input to the bus (1), (
2) will function as a collective relay that protects all at once.

Figure 4, the 51st threshold is the contact α7bL in Figure 8 when the bus bar is short-circuited.
(27b)'-(181aL (182a), (1
88a), (28ta).

(282a), (288a) is a circuit diagram showing an example of a switching circuit that controls opening and closing.

αη, @ are the ノ(shi and soto contacts) that are linked to the opening and closing of the disconnector.
a-10), (a-20), (a-go),
(4-10), (4-20), (4-ao)
Force (by closing the circuit, the busbars (1), (2)
This is a bus bridge detection relay that detects a short circuit between the auxiliary relays Qsl)p(18-2), (18-8),
Operate (28-t), (28-2), and (28-a).

Next, I will explain about young works. In the switching circuit, when the busbars are short-circuited due to a failure of the disconnector, the busbar bridge detection relay α operates to avir the current derived from the busbar connection line (6) through contact Q7b).

(27b) and all transmission lines (5-t) to (5-
8) Input the IT flow derived from the selection relay @, @ Now, in Fig.
, i line (51)
) I is closed, disconnected (471), (4-S (a
- Is the external fault module transmitting power while the disconnector (4-2) is short-circuited when a) should be open? Let us consider the case where yo (5-S) occurs.

The fault current I2 flowing into the power supply circuit (6-) is divided into the current 11 passing through the disconnector ω- and the current 11 passing through the new circuit (4-1). ) and flows out below the fault point. The secondary current of each current transformer at this time is considered in the same way as shown in Figure 2, and current transformer ω-2) is +(il+1gL current transformer (8-8) is -(
il +iz), the current transformer (9-1) is -1ip, and the current transformer (s-2) is 1. On the other hand, the auxiliary relay contact (18
-1ω~(18-8a)(28-1a)~(g8-8ω
The state was the same as the open/closed state of the grid disconnector, but because the disconnectors (8-2) and (4-a) were both closed and the busbars were short-circuited, the busbar bridge was detected in Figure 4. Relay aη, @ operates, contact Q7 in Fig. 5
This contact (17ω,
(27a) is closed, the auxiliary relays (18-1) to (1
8-a), (2g-1) to (2s-8) operate, so all auxiliary relay contacts (1g-1a) to (18-
8a), (28-1a) to ((28-8a) are closed. Furthermore, with the operation of bus bridge detection relay 07) #@, the contacts in Fig. 8, (17ω, (27b)
is input device α41. In order to cut off the output of H, it is connected to an enclosure. In addition, the input device output 61 current transformation -1d ~ (IF8
The output composite value of ω is zero (itp +12o) Ci
l.

+ ia ) =O), also for the second selection relay (2), the output composite value of the second input device (28-1ω to (24!-8-) is zero [0+ (ile +12o) (i
lo +12o) = 0), and the selection relay θ
In the case of a busbar bridge, '4° (a) functions as a collective relay that protects the entire busbar, and will not malfunction even if an external failure occurs.

Next, a further improved embodiment of the busbar protection relay device according to the present invention will be described.

In the case of the embodiments shown in Figures 98, 4, and 5, the problem of swivel flow occurs. In this case, malfunctions due to induced current can be prevented by simply setting the following conditions as shown in the embodiments of FIGS. 8 to 5. 6th
In the figure, (1-1), (1-2)1(2t) e
(22) *ω-1) is the power line disconnector, (1-1,
(1-2, 0-1υ, C-2wa, and ω-da are earthing disconnectors.

Currently, the transmission line C5-t) is out of service, so the transmission line 1 disconnector (1-
1), (1- are both open circuits, earthing disconnectors (1-19° (1-2F) are both closed circuits, the above embodiment, No. 8
Consider the same situation as in the figure. In addition, other power line disconnectors (2-1
), (2-, and (a-1) are both closed circuits and earthing/disconnecting switches (
2-IE), (2-2F), (a-to are both open circuits.

In the case of 1, the input to the selection relay is switched by the switching circuit so that the inflow 'd current and the outflow current cancel each other out, and their combined value becomes zero.

Inductive action occurs in the power transmission line (5-1) forming the closed loop 4, and an induced current IO flows. Due to this induced current I0,
The secondary current of current transformer (s-1) is -i. Then, the output of input device (18-1), (28-1) -ioo (i6
In the case of a bus bridge, the proportional value of If it is grounded and an induced current is generated, this current becomes an error current and causes the failure relay to malfunction due to an external failure.

As a countermeasure for this, a condition may be added to the switching circuit to exclude the current drawn from the grounded power transmission line.・Additional conditions are shown in the m7 diagram. The same figure is shown in Figure 5.
) * (21E) e (Pallet contacts linked to the opening and closing of 81υ (1-1oυ, (2-10, ω-1O) are added as priority conditions.

That is, auxiliary relay (Is-t) ~ (18-8), (2
8-1) to G28-8) are earthing disconnectors 0-10 to (8-
1 Under open conditions, it performs its original function, but when any of the earthing disconnectors (1-1F:) to ω-1 is closed, it is necessary to cut off the current of the corresponding power transmission line. , opens the auxiliary relay contacts. In the case of Figure 6, the power transmission line (5
-1) is grounded and the grounding/disconnecting switch 0-1 is closed, so the auxiliary relay contacts α8-1a) to (28-
1a) is open circuit.

Therefore, the input to the selection relay (2), @ becomes zero, and countermeasures against induced current can be easily taken with the present invention.

As described above, according to this invention, by effectively incorporating a switching circuit, a bus protection relay device that does not malfunction even when the bus bars are short-circuited by a disconnector can be created. It has the effect of being able to charge at low cost with a simple configuration without providing any equipment, and that it is also highly reliable.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram of a conventional bus protection relay device, Fig. 2 is an explanatory diagram of an example in which a selective differential relay malfunctions due to an external failure in the case of a single bus bridge, which is a drawback of the conventional system, and Fig. 8. Fourth
, and 5 are circuit diagrams showing an embodiment of the bus bar protection relay device according to the present invention, and FIGS. 6 and 7 are
FIG. 3 is a circuit diagram showing another embodiment of the present invention. In the figure, (1) is the first busbar, (2) is the second busbar (a-1) to ω-8) is the first disconnector group, and (8-10) is the first busbar.
, (8-20). (8-8 is the first pallet contact, (4-1) to (4-
8) is the second disconnector group, (4-to), (4-20)
, (4-go) is the second pallet contact, (5-1) ~
(5-8) is the power transmission line, (6) is the busbar connection (18-8), α
or first input device% (28-1) ~ (28-8)e
e4 is the second input device, Qη is the first bus bridge detection is the second contact point, Qs-1) to Qs-s) are the first auxiliary relays, (28-1) to (28-8) are Second auxiliary relays 08-1a) to (18-8a) are first auxiliary relay contacts, and (28-1a) to (28-8a) are second auxiliary relay contacts. In each figure, the same reference numerals indicate the same or corresponding parts. Agent Shin Kuzuno −

Claims (2)

[Claims] (1) An f41 bus bar is connected to each of a plurality of power transmission lines via a first disconnector group, and is connected to each of the above power transmission lines via a second disconnector group and connected to the first busbar. In this device, the current drawn from each transmission line and the current corresponding to the current between the first and second bus bars are input, and the difference between the inflow and outflow (flow) is calculated. A responsive differential relay relay is connected to the differential relay, and -1 is derived from the line corresponding to either the first or second disconnector group that is closed. The circuit selects and inputs the current generated by the bus, and when both the bus bars are short-circuited by the disconnectors of the first and second disconnector groups, the circuit corresponds to the open current of the first and second busbars. A switching circuit for cutting off current input to the differential relay and inputting current derived from all power transmission lines to the differential relay. (2) The switching circuit is one of the first or second disconnector groups of the power transmission line that is closed and is not grounded.・
2. The busbar protection relay device according to claim 1, wherein only the corresponding one is selected.