JPH0324129B2 - - Google Patents

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. The present invention relates to a fault section detection system.

(Conventional technology) The basic equipment configuration of an unmanned substation is that a two-line power receiving section is connected to both ends of a single bus, and power is received from one or two lines, and multiple transformers are connected to these buses at the same time. They are typically connected together, with each transformer transmitting power to multiple loads.
Since current transformers are installed on the line side of the power receiving section, in the event of a failure, whether it is internal or external to the substation depends on the operating state of the current transformer at the power receiving section, so if a malfunction occurs, it will be sent to a remote control station. You can also know from. However, if an internal failure occurs in the busbar 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. This has the disadvantage that power outages can be large-scale and long-lasting.

(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 a substation failure section detection system that can immediately retransmit power to a healthy section by isolating the faulty section.

(Means for Solving the Problems) The present invention divides a busbar 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 busbar support insulator equipped with a photocurrent sensor. A matrix method is used to determine the section where a failure has occurred based on the output signals of the current transformer, ground fault, and short circuit relays attached to the power receiving section, and the output signal of the photocurrent sensor attached to the mothership support insulator. That is.

(Example) Next, the present invention will be explained in more detail according to the illustrated example.

FIG. 1 is a plan view showing the equipment form of a typical unmanned distribution substation, where 1 and 2 are the first and second power receiving sections, 3 is the bus bar section, and 4, 5, and 6 are the first and second power receiving sections. , 3rd
It is a transformer. Three lead wires 3a, 3b, 3c corresponding to each phase of three-phase alternating current are stretched on the bus bar 3, and three transformers are connected to each of these wires 3a, 3b, 3c as shown in the figure. The devices 4, 5, and 6 are connected to each other. Power is normally received by one of the power receiving units 1 and 2, and power is supplied to the three transformers 4, 5, and 6 via these lead wires 3a, 3b, and 3c, and each transformer is connected to its respective load. It distributes power to the side. The power receiving units 1 and 2 are each provided with a disconnector 7, a current transformer 8, and a circuit breaker 9, and the current transformer 8 is further connected to ground fault and short circuit relays 10 and 11 such as OCR and OCGR. It is now possible to detect ground faults and short circuits within substations. On the other hand, each lead line 3a, 3b, 3c of the busbar section 3 is divided into three sections A, B, and C by busbar disconnectors 12 and 13, but in the present invention, these busbar disconnectors 12 ，
The support insulator 13 is equipped with a photocurrent sensor 14 as shown in FIG.

That is, in FIG. 2, 15 is a busbar support insulator for supporting the busbar disconnector 12, 12a is a blade of the disconnector, 12b is a contact, and 12c is a terminal plate. A photocurrent sensor 14 consisting of a doughnut-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 bus bar support insulator 15. Note that 17 and 18 are airtight pipes and airtight containers provided above and below the bus bar 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 FIG. 3, the photocurrent sensor 14 includes an emitting element 1
9 and the light receiving element 20 are connected, and when a change in current is detected, the level detector 21 detects a ground fault.
A short circuit is determined, and a fault section discriminator 22 detects current transformers 8 of power receiving units 1 and 2, ground faults, and short circuit relays 1.
The failure section is determined in conjunction with the signals from 0 and 11. This determination is performed using a matrix method, and the specific details thereof will be explained below.

(Operation) Next, a determination method using a matrix method will be described in the case where an internal accident occurs during power reception in the first power receiving unit 1. First, when a failure occurs in the A section of the bus section 3, the current transformer 8 of the power receiving section 1 operates, but the bus disconnect switch 1 that separates the A section and B section
Since both photocurrent sensors 14 2 and 13 do not operate, it is possible to know from this that there is a failure in section A. In this case, by opening the bus disconnector 12, the faulty section is isolated, and if power is received by the second power receiving section 2, the sections B and C are healthy.
It will be possible to immediately resume power distribution to the area. Next, when a failure occurs in section B, the current transformer 8 of the power receiving section 1 and the photocurrent sensor 14 of the busbar support insulator 15 between A and B are activated, but
Since the photocurrent sensor 14 of the busbar support insulator 15 in between does not operate, it is possible to know that a failure has occurred in section B. In this case, the faulty section is isolated by opening both the bus disconnectors 12 and 13, and the healthy section A, by receiving power at both the first and second power receiving sections 1 and 2, Power distribution to section C can be resumed immediately. 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 1 and the photocurrent sensor 14 of the bus support insulator 15 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 section 1, determination using the matrix method is similarly possible when power is being received by the second power receiving section 2. It goes without saying that even if a failure occurs in any section, the ground fault and short circuit relays 10 and 11 connected to the current transformers 7 of the power receiving units 1 and 2 are activated. If the output of the current transformer 3 is not available, the phase of the output of the photocurrent sensor 14 is compared as shown in FIG. It is also possible to determine whether or not an accident occurred.

(Effects of the Invention) As is clear from the above description, the present invention utilizes a photocurrent sensor attached to a bus support insulator to detect a failure when a failure occurs inside a distribution substation equipped with a plurality of transformers. Since the section can be immediately identified, the disconnection of the faulty section and the transmission of power to the 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 busbar support insulator, 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 caused by electric fields, magnetic fields, etc., 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 cross-sectional view showing how a photocurrent sensor is attached to a busbar support insulator used in the present invention, and FIG. 3 is a block diagram of the entire system. FIG. 4 is a circuit diagram and a current diagram illustrating a detection method when the output of an existing current transformer cannot be used. 1, 2: power receiving section, 3a, 3b, 3c: bus bar,
4, 5, 6: Transformer, 8: Current transformer, 10, 11:
Earth fault, short circuit relay, 14: Photocurrent sensor, 15:
Busbar support insulator, 16: Optical fiber.

Claims (1)

[Claims] 1 Bus bars 3a, 3b connected to power receiving units 1, 2,
3c as a bus bar support insulator 15 with a photocurrent sensor 14
It is divided into multiple sections A, B, and C to which multiple transformers 4, 5, and 6 are connected, and the section where the failure occurred is connected to the current transformer 8 attached to the power receiving parts 1 and 2 and the ground fault. A fault section detection system for a substation, characterized in that determination is made by a matrix method from output signals of short-circuit relays 10 and 11 and an output signal of a photocurrent sensor 14 attached to a mother ship support insulator 15. 2 The photocurrent sensor 14 is one with an iron core that uses a Faraday element such as YIG or BSO as a sensor element, and the optical fiber 1 built in the bus bar support insulator 15
6. The fault section detection system for a substation according to claim 1, wherein the signal is taken out through the substation.