JPS63107416A - Method of monitoring abnormality in sheath current suppressor - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an abnormality monitoring method of a sheath current suppressing device,
In particular, I was inspired by the method for monitoring abnormalities in sheath current suppression devices in power cable lines equipped with sheath current suppression devices.

[Conventional technology]

Generally, in a three-phase power cable line, in order to suppress the sheath current flowing through the sheath circuit of the power table line, the sheath current is reduced as much as possible during normal times, and this is reduced in case of an excessive sheath current due to an accident, etc. Equipped with a sheath current suppressor with earthing function.

[Problem that the invention seeks to solve]

By the way, in such a cable line,
``Lower margin'' - If protection against surges, etc. is not sufficient, sheath surges may cause abnormalities such as interlayer short circuits in the windings of the sheath current suppressor, and there is a risk of fire due to heat generated at the short circuit. Since the sheath current suppressing device is entirely covered with rubber, there is a problem in that abnormalities cannot be visually detected from the outside.

[Purpose of the invention]

An object of the present invention is to provide a method for monitoring abnormalities in a sheath current suppressing device, which can improve the disadvantages of the conventional example and monitor abnormalities in the sheath current suppressing device without changing the main configuration of the sheath current suppressing device. purpose.

[Means for solving problems]

Therefore, in the present invention, the sheath 1 installed on the cable line
A method is adopted that detects the terminal voltage of the α-flow suppressor and the sheath current of the cable line, calculates the impedance based on these outputs, and outputs an alarm signal if the impedance differs from a predetermined reference value. The aim is to achieve the above objective by doing so.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG.

In this figure, the three-phase cable line has each sheath circuit A,
B, O, normal junction box 1A to 1C1 insulated junction box 2A to 2C and 3A to 30. The sheath current suppressing device 4 and the cross bonding wires 5 and 6 are the main components, and as shown in the figure, the combination of these components is set as a unit of one section, and a total of N pieces (N-1, 2, 3, . . . ... ,
n) is formed by the cross bond section. Furthermore,
As shown in the three-phase cable line, there is a sheath current suppressor abnormality monitoring device (hereinafter referred to as [referred to as an abnormality monitoring device J) 1 is equipped.

The sheath current suppressing device 4 reduces the sheath current in the three-phase cable line in the normal energized state as much as possible, and in the case of an excessive sheath current due to a ground dragon accident, etc., the sheath current suppressing device 4 reduces the sheath current as much as possible in the normal energized state and makes this the sheath return path as much as possible. It has a saturable impedance characteristic that provides low impedance, and specifically, it is composed of an axle with a saturable characteristic.

On the other hand, the abnormality monitoring bag fn1 is composed of a current/voltage detection section 2 and an alarm output section 3, which are provided for each section of each sheath circuit A to C.

Specifically, as shown in FIG. 2, this current/voltage detection unit 2 includes a sheath current detection means 20 having a function of detecting the sheath current flowing through each section of the sheath circuits A, B, (:!).
And Sheath II! A terminal voltage detection means 22 having a function of detecting the terminal voltage of the flow suppressing device 4, and calculating impedances ZA to ZO based on these detection data,
The alarm output section 3 is configured to send an alarm signal P to a central control room (not shown) when the impedance is below a predetermined reference value. It has a function to send to

Next, the specific operation of this embodiment will be explained.

The impedance of the sheath current suppressing device 4 is usually about 0.5 [Ω] to 1 [Ω], for example, and the impedance decreases when the reactor of the sheath current suppressing device 4 causes an interlayer short circuit. Then, the alarm output unit 3 uses the normal impedance of 0.5 [Ω] as a reference value,
The output of the current/voltage detector 2, that is, the impedance ZA to Zo of each sheath current suppressor 4, is constantly compared with this reference value, and if the output is less than the reference value, an alarm signal P is output.

As described above, in this embodiment, the impedances ZA to zo of the sheath current suppressing devices 4 provided in each section of each sheath circuit A to C are calculated by the action of the current voltage detection section as described above, and the respective outputs are calculated. The alarm output unit 3 constantly compares with the reference value, and if it is determined that there is an abnormality, an alarm signal P is output.
Therefore, an abnormality in each sheath current suppressing device 4 can be quickly discovered.

〔Effect of the invention〕

As described above, the present invention detects the sheath current flowing through the sheath circuit and the terminal voltage applied to the sheath current suppressing device, calculates the impedance, and outputs an alarm signal when this impedance does not match a predetermined value. Therefore, the state of the sheath current suppressing device can be constantly monitored without changing the configuration of the sheath current suppressing device, and abnormalities can be easily discovered.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the implementation status of the present invention, and FIG. 2 is a specific configuration diagram of the abnormality monitoring device.
−−−−−−−1 Abnormality monitoring device 2 −−−−−−−−−−
- Current/voltage detection section 3 ---------- Alarm output section 4 - Sheath current suppressor 20 ------- -------Sheath current detection means 22-1------One terminal voltage detection means 24
−−−−−−−−−One calculation means ZA, Z B *Za
---I>Heater> SP ---------------1---Alarm Signal Agent Patent Attorney Yama 1) Akira Shin゛-゛1.
Figure 7

Claims (1)

[Claims] Detecting the terminal voltage of a sheath current suppression device installed on the cable line and the sheath current of the cable line, calculating impedance based on these outputs, and calculating the impedance that differs from a predetermined reference value. An abnormality monitoring method for a sheath current suppression device that outputs an alarm signal when