JPS60174015A - Protecting relay system - 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 [Field of Application of the Invention] The present invention relates to a protection relay system for a power system, and particularly to a protection relay system that detects a system fault using a Faraday effect element.

[Background of the invention]

For example, a Faraday effect element such as a magnetic thin film YIG (iron-garnet) has the property that the plane of polarization of light rotates in proportion to the strength of the magnetic field.

In FIG. 1, the incident light emitted from the light source G1 is G
Although the light is randomly polarized as shown in 2, when it passes through a polarizer (polarizing beam splitter) G3, it becomes linearly polarized light G4. Furthermore, this is a Faraday effect element G5 such as YIG.
When a magnetic field H is applied to this Faraday effect element G5 in the direction shown in the figure, the plane of polarization rotates by an angle of 7 degrees of rotation θ proportional to the strength H of the magnetic field, resulting in an output G6. The analyzer 07 extracts only the horizontal component of this rotation angle θ as output light as shown in C8, and calculates the magnitude of the rotation angle θ,
In other words, the magnitude of the magnetic field and, by extension, the magnitude of the current can be determined. This principle is a known fact.

[Purpose of the invention]

An object of the present invention is to use such a Faraday effect element to detect a system fault that occurs in a power system based on the differential principle.

[Summary of the invention]

By controlling the action of the Faraday effect element, we have created a protection relay system that can reflect only the system information necessary for protection, that is, only the rotation angle information of the optical signal polarization plane based on the current information of the contacts inside and outside the protection range, in accident judgment. provide.

[Embodiments of the invention]

As a typical embodiment of the present invention, an example of application to a busbar protection relay will be described with reference to FIG.

In the figure, Bl, B2 are the busbars of the substation, CBI, C
B2 is a bus section breaker, CB3 is a bus tie breaker, and Fl and F2 are Faraday effect elements, which detect the magnetic field caused by the current flowing through the illustrated part of the bus bar, and detect the polarization plane of the optical signal passing through it. It functions to give a rotation angle depending on the strength of the magnetic field. L1 to L8 indicate the power transmission lines connected to the above busbar and operated, and CBL1 to
CBL8 has a breaker, LSII.

L812. L821. L822. LaB5゜L832.
LS41. L842. LS51°LS52. L861.
L862. LS71°L872. LaB5. LaB5 indicates a line switch. G1 is a light source, and PD is a light receiving element.

2. Detection of the current flowing in the transmission current by the Faraday element is performed at each end detection section Kl. 3. 4. 6°K7. 8.
9, but since all of 1 to 9 are constructed with similar devices, only Kl and 6 are shown in their entirety in Figure 2, and detailed illustrations of the other detection sections are omitted. . 81.86 inside Kl and 6 is an optical switch, K is an optical signal input end to this optical switch, and A and B are two output ends of the optical switch. The light input to the input end is transmitted to the terminal M1. According to the 0N10FF status of the signal applied to M6, it operates to switch to output to the A end or the B end.

Furthermore, C is arranged to connect each Faraday effect element.
I, C11, C13, C12, C21゜031.041
．． C2, C91, C81, C71°C61,062,
C63 and C3 indicate optical fibers.

In the configuration shown in FIG. 2, Ml is configured to provide the open/close status of line switch L831 (LaB2), and M6 is configured to provide line switch LSII (LS12).
It is obvious that the measurement conditions for the angle of rotation of the polarization plane of the optical signal can be configured to reflect the system configuration conditions at that time.

For example, in the case of the system configuration shown in Figure 2, considering the maintenance charge for bus B1, from the open/closed state of the line switch,
The power transmission line connected to this bus B1 is L2. L4. L
5. 6.L7.L8, the operation of the optical switch opens and closes according to the open/closed state of the line switch in question, so that the optical signal is transmitted to the Faraday effect element of the detection section 3 in Kl. Other than this, 2., 4., and 5 do not pass.
゜K6. 7. An optical signal passes through each of the 8 Faraday effect elements in series, and at each Faraday effect element, this optical signal is affected by a magnetic field proportional to the magnitude of the current flowing therethrough, causing rotation in its plane of polarization. Therefore, by measuring the optical signal detected by the light receiving element FD, a busbar maintenance mIJ beam based on the differential principle can be realized.

〔Effect of the invention〕

According to the present invention, since the voltage on the grid side is extremely high potential, a conventional CT that requires insulation using a large insulator is unnecessary, and a highly reliable protection relay system with extremely high detection accuracy is achieved. can be provided.

[Brief explanation of drawings]

FIG. 1 is a diagram for explaining that light is polarized by a Faraday effect element, and FIG. 2 is a diagram showing an embodiment of the present invention. C...Optical fiber, F...Faraday element, P
D... Light receiving element, K... Detection section. Agent patent attorney Akio Takahashi also 1?

Claims (1)

[Claims] ゛1. An element having a magnetic φ optical effect, such as a Faraday effect element, is arranged at each terminal, and the optical signal emitted from the light emitting element serving as a light source is configured to pass through each of the j-order Faraday effect elements. , the plane of polarization of the optical signal passing through the Faraday effect element of each terminal was rotated in accordance with the strength of the magnetic field due to the system current of that terminal, and each of the seven Alladay effect elements was passed through in series. In the relay system, an optical switch is placed on the input side of each Faraday effect element, and an optical switch is placed on the output side of each Faraday effect element. One optical inserter is inserted in each, one of the two output ends of the optical switch is arranged so as to form an optical signal transmission route to the input side of the Faraday effect element, and the other output end is , arranged so as to form an optical signal transmission route to one input end of the optical inserter inserted into the output side of the Faraday effect element, and opening/closing the corresponding optical switch to activate/deactivate the Alladay effect element. A protection relay system characterized by being able to configure differential conditions for the rotation angle of the polarization plane of an optical signal at any time to reflect the operating conditions of the system.