JPH01148018A - System for detecting fault section of substation - Google Patents

Abstract

PURPOSE:To quickly execute restoration work, by using an photocurrent sensor fitted to a bus supporting insulator to discriminate a fault section when a fault is generated in a distribution substation provided with a plurality of transformers. CONSTITUTION:An unattended distribution substation is provided with a first - a second incoming sections 1-2, a bus-bar section 3, and a first - a third transformers 4-6, and via the respective leaders 3a-3c of the bus-bar section 3, current is fed to the three transformers 4-6 and is distributed to the side of a load. Besides, the incoming sections 1-2 are respectively provided with disconnectors 7, current transformers 8, and breakers 9, and to the current transformers 8, the grounding and short circuit relays 10-11 of an OCR and the like are connected, and grounding and short-circuit accidents in the substation are detected. The respective leaders 3a-3c are divided into three sections A-C with bus line disconnectors 12-13, and the supporting insulator 15 is provided with an photocurrent sensor 14. Then, grounding and short-circuit are discriminated by the sensor 14, and a fault section is discriminated, and the fault section is separated from, and current is automatically transmitted to a sound section.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention is a substation that makes it possible to easily know the faulty section from the outside when a fault occurs in a substation equipped with a plurality of transformers. This is related to the failure area/quantity detection system at the facility.

(Conventional technology) The basic equipment configuration of an unmanned substation is that two power receiving sections are connected to both ends of a single bus, receiving power from one or two circuits, and multiple transformers are installed on these buses. They are typically connected at the same time, with each transformer transmitting power to multiple loads.

And since a current transformer etc. is installed on the line side of the power receiving part,
When a failure occurs, whether it is an internal failure or an external failure in the substation can be known from a remote control center based on the operating status of the current transformer in the power receiving section. However, if an internal failure occurs in the bus bar section of a substation, the failure area cannot be known from the outside, and all multiple transformers are shut down until workers go to the site and discover the location of the failure. Because I have no choice but to
The disadvantage is that power outages are large-scale and last for a long time.

(Problems to be Solved by the Invention) The present invention solves the conventional problems as described above, and makes it possible to easily know the faulty section from a remote control center when an internal failure occurs in a substation. This system was developed for the purpose of creating a faulty section detection system for substations that can immediately retransmit power to a healthy section by isolating the faulty section.

(Means for Solving the Problems) The present invention divides a bus connected to a power receiving unit into a plurality of sections A, B, and C to which a plurality of transformers are connected by a bus disconnector equipped with a photocurrent sensor. The section in which the fault has occurred is determined using a matrix method based on the output signals of the current transformer, ground fault, and short circuit relay installed in the power receiving section, and the output signal of the photocurrent sensor installed in the busbar new line switch. Characteristics (Examples) Next, the present invention will be described in more detail according to illustrated embodiments.

FIG. 1 is a plan view showing the equipment form of a typical unmanned distribution substation, (l) and (2) are the first and second power receiving sections, (
3) is the busbar part, (4), (5), and (6) are the 11th and 2nd parts,
This is the third transformer. The bus bar section (3) has three bus NIAs (3a), (3b), (3c) corresponding to each phase of the three-phase AC.
) are stretched, and each of these busbars (3a) and (3b
), (3c), three transformers (4) as shown.
, (5), and (6) are connected to each other. Then, power is received by one of the power receiving units (1) and (2), and these mother units 1t! Power is supplied to three transformers (4), (5), and (6) via (3a), (3b), and (3c), and each transformer distributes power to its respective load side. The power receiving parts (1) and (2) are equipped with a new line switch (7) and a current transformer (8).
), a circuit breaker (9) is provided, and this current transformer (8) is equipped with a ground fault and short circuit relay (such as OCR, 0CGR).
10) and (11) are connected so that ground faults and short circuits within the substation can be detected. On the other hand, each company'1IA (3a), (3b) of the busbar part (3),
(3c) is connected to A by the bus disconnectors (12) and (13).
Although it is divided into three sections B and C, in the present invention, these bus disconnectors (12) and (13) are equipped with a photocurrent sensor (14) as shown in FIG. has been done.

That is, in Fig. 2, (15) is a support insulator for supporting the bus disconnector (12), (12a) is the blade of the disconnector, (12b) is the contact, and (12c) is the terminal plate. be. A photocurrent sensor (14) consisting of a donut-shaped iron core (14a) and a sensor element (14b) is attached around the terminal plate (12c), and extracts the current flowing through the bus bar as an optical signal. It is preferable to use a Faraday element such as YIG or BSO as the sensor element (14b), and the optical signal is taken out to the outside via an optical fiber (16) built into the support insulator (15). In addition(
17) and (18) are airtight pipes and airtight containers provided above and below the support insulator (15) to prevent the insulation of the optical fiber (16) from deteriorating. The support insulator to which this photocurrent sensor is attached may be attached at a different location from the disconnector. As shown in Figure 3, a light emitting element (19) and a light receiving element (20) are connected to the photocurrent sensor (14), and when a change in current is detected, a level detector (21) is used to ground the light. It distinguishes between circuits and short circuits, and furthermore, in the fault section discriminator (22), it combines the signals from the current transformers (8) of power receiving sections +1) and (2), ground faults, and short circuit relays (10) and (11). The fault section is determined. This determination is performed using a matrix method, and the specific details thereof will be explained below.

(Function) Next, a determination method using a matrix method will be described in the case where an internal accident occurs while receiving power in the first power receiving unit (1). First, if a failure occurs in section A of the busbar section (3), the current transformer (8) of the power receiving section +11 will operate, but
Busbar disconnectors (12) and (13) that partition A section and B section
) photocurrent sensor (14) does not operate,
This makes it possible to know the failure in section A. In this case, if the faulty section is disconnected by opening the bus disconnector (12) and power is received by the second power receiving section (2), the section B becomes a healthy section.

It will be possible to immediately resume power distribution to section C. Next, if a failure occurs in section B, the power receiving unit +11
The current transformer (8) and the photocurrent sensor (14) of the bus disconnector (12) between A and B operate, but the photocurrent sensor (14) of the bus disconnector (13) between B and C operates. ) does not operate, so it can be known that a failure has occurred in section B. In this case, the bus disconnector (12), (
13) (thereby isolating the faulty section, and both the first and second power receiving sections +1) and receiving power at (2), immediately resume power distribution to the A1C section, which is a healthy section. Can be done.

Further, the occurrence of a failure in section C can be known from the fact that the current transformer (8) of the power receiving section (11) and the photocurrent sensors (14) of the bus disconnectors (12) and (13) are all activated.

In this case, by opening the bus disconnector (13) between B and C, the failed section can be disconnected and power distribution to the healthy sections A and B can be immediately resumed.

Note that although the above explanation has been made regarding the case where power is being received by the first power receiving unit +11, determination using the matrix method is similarly possible when power is being received by the second power receiving unit (2). Also, it goes without saying that if a failure occurs in any section, the ground fault and short circuit relays (10) and (11) connected to the current transformers (7) of power receiving sections +1) and (2) will be activated. stomach. In addition, if the output of the current transformer (8) is not available, the photocurrent sensor (1) is used as shown in FIG.
It is also possible to compare the phases of the outputs of step 4) and determine whether the accident occurring between the two photocurrent sensors (14) is an accident occurring outside of the two photocurrent sensors (14).

(Effects of the Invention) As is clear from the above description, the present invention utilizes a photocurrent sensor attached to a bus disconnect switch when a failure occurs inside a distribution substation equipped with a plurality of transformers. Since a faulty section can be immediately identified, isolation of a faulty section and power transmission to a healthy section can be carried out automatically or in a short time by commands from a remote control center. Therefore, the power outage time and power outage area can be minimized, and it is also effective in speeding up restoration work. Moreover, in the present invention, since the photocurrent sensor is attached to the bus disconnect switch itself, no extra space is required, and it can be easily installed in unmanned substations with small spaces. Since it is difficult to pick up noise, it is possible to construct an extremely reliable system. Therefore, the present invention greatly contributes to the development of industry as a substation fault section detection system that eliminates the problems of the conventional system.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing an embodiment of the present invention, FIG. 2 is a sectional view showing how a photocurrent sensor is attached to a bus disconnector used in the present invention, and FIG. 3 is a block diagram of the entire system. Fourth
The figure is a circuit diagram and a current diagram illustrating a detection method when the output of an existing current transformer cannot be used. 11), (2): Power receiving section, (3a), (3b), (3c
): Busbar, (4), (5), (6): Transformer, (8)
: Current transformer, (10), (11): Earth fault, short circuit relay, (
12), (13): Busbar new circuit device, (14): Photocurrent sensor, (15): Support insulator, (16): Optical fiber. Fig. 1 16: fC,, Puaino ( Fig. 2
%N of r (b) Qsa in F2
t (Hikari t Nsa Mazumetei 1 Jo) (Gai-on p-ken name history) Procedural amendment (voluntary) November 24, 1988

Claims (1)

[Claims] 1. Bus bar (3a) connected to power receiving units (1) and (2);
(3b) and (3c) are connected to a plurality of transformers (4) by bus disconnectors (12) and (13) with photocurrent sensors (14),
(5), (6) are connected to multiple sections A, B, and C, and the section where the failure occurred is connected to the power receiving section (1), (
2) installed on the current transformer (8) and ground fault/short circuit relay (1)
0), (11) and bus disconnectors (12), (
13) A fault section detection system for a substation, characterized in that a determination is made by a matrix method based on an output signal of a photocurrent sensor (14) attached to a substation. 2. The photocurrent sensor (14) uses a Faraday element such as YIG or BSO as a sensor element, and the photocurrent sensor (14) takes out a signal through an optical fiber (16) built in a support insulator (15) of a bus disconnector. A fault section detection system for a substation according to scope 1.