JPS62107645A - Monitor signal transmission - 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 Cats) The present invention relates to a method of transmitting an alarm signal obtained by fully monitoring the e-stable status of an electric line.

(Prior art) In general, monitoring the insulation of the secondary low-voltage line of the receiving transformer, which receives high-voltage electricity and converting it into low-voltage electricity, while it is live, or monitoring abnormal temperature rises in the receiving 11i transformer. This is done to prevent any electrical accidents and provide a safe power supply. on the other hand.

These monitoring devices are installed in the power receiving room where the receiver'fLf pressure regulator is installed, but no one is permanently stationed in the power receiving room.
Therefore, it is necessary to transmit an alarm signal or the like to a compensation center or control center where a person is permanently stationed based on the results detected by the monitoring device.

Conventionally, this alarm signal was transmitted by modulating multiple alarm signals to be transmitted through the grounding wire of the 8g type 2 grounding work of the lighting transformer (single-phase three-wire electrical circuit) in the above-mentioned transformer. All low frequency signals are applied, and a receiver installed in the office detects and demodulates the low frequency signal induced between the ground phase of the single-phase three-wire electric line and the 3rd grade ground construction line, and generates the vlll multiplied signal. It was determined whether the data was being transmitted or not.

(Problems to be Solved by the Invention) However, in the conventional alarm signal transmission method described above, a frequency of about 1 to 1 QKHz is generally used as the frequency of the low frequency signal modulated by the alarm signal. This is because the higher the frequency, the more the signal is attenuated at the receiving point due to the capacitance between the ground and the ground, and the signal may not be received correctly. This is because the injection transformer to be used becomes large and uneconomical. When a low-frequency signal of 1 to 10 KHz is applied to a lighting circuit through a type 2 grounding wire, the low-frequency signal is radiated from the circuit. ~l0KI-12
There is a problem in that the low frequency signal goes around to audio equipment, broadcasting equipment, m-talk equipment, etc. that handle signals that handle audio bands including high frequency bands, and mixes into these negative VR equipment as noise.

(Means and operations for solving all the problems) The present invention was made to solve the problems of the conventional method as described above. By using means for applying voltage to the second type grounding wire of the power transformer (three-phase three-wire electric circuit) instead of applying it to the second kind grounding wire of the electric lamp to which the above-mentioned load equipment is connected. The present invention provides a monitoring signal transmission method that prevents the low frequency signal from being superimposed on the electric path, thereby preventing the low frequency signal from going around to load equipment. With this configuration, signal transmission is easily possible by detecting and reversing the low frequency signal induced between the ground phase of the power line and the class 3 engineering ground at the receiving point. Even if they are close to each other, the signal level at which the low frequency signal applied to the power line leads to the lighting line is so small that the effect on the load equipment as described above can be ignored.

(Example) The present invention will be described in detail below based on illustrated embodiments.

Is Fig. 1 an embodiment of the present invention? FIG. In the same figure, Tz is a three-phase three @ (200
The transformer transformed into the power line V) is shown, and the secondary line 3 is grounded to the grounding point E2 with the ground @10 of the second type of grounding work.

In addition, Tz is high-voltage electricity 5KV2 single-phase three-wire (100/200
V) is a transformer for converting into a lighting circuit.The secondary circuit 5 of the transformer l112 is the grounding wire 11 of the second type grounding work.
It is grounded to the ground point E2 via.

The alarm signal receiving device 20 is grounded near the transformers T+ and Tz and is grounded in all offices, etc., where the monitoring device 9 which monitors insulation by some means (not shown) is generated.
This shows the case of transmission to .

First, it is assumed that there are three types of alarm signals output from the monitoring device: normal, caution, and warning. Yes, and "Warning" indicates that the insulation has deteriorated and is in a critical condition. In this embodiment, any one of these plurality of signals is transmitted, and when there is no abnormality, the normal J signal is transmitted constantly or intermittently. The transmitter 8 transmits, for example, respective unique frequencies f1 to the above three types of signals. ．． The low frequency signals f2 and f3 are all generated and applied to the ground line 10 via the transformer 8 coupled to the ground line 10, thereby superimposing the low frequency signal on the power line.

On the other hand, in the compensation signal receiving device 15 described in f#1, the above-mentioned low frequency signal induced between the ground phase 3 of the power line and the grounding wire 14 of the third type grounding work (- ground may also be used) is transferred to the capacitor. 13 to the receiving circuit 15. The input impedance of this receiving circuit 15 is high so that it does not affect the line '6 connecting it, and the frequency f1. f=and f3
All three alarm signals (P) of ``normal'', ``caution'', and ``warning'' are output in response to the presence or absence of the alarm.

Incidentally, the tip/screw is a direct current blocking component designed to be useful when inspecting the insulation of this electrical circuit with a megger or the like. Electric light circuit 4
．． Lines 30 and 40 connected to 6 are power supplies (100 V) that supply the receiving circuit.

(Effect of the invention) By having the above configuration, l:1.71! Since no low frequency signals are applied to the light line, the light line (ACloo
This is because low-frequency signals do not go around to the audio equipment, etc. connected to the V), and noise that interferes with the audio equipment, etc. can be avoided.

This is effective in realizing a stable alarm signal.

[Brief explanation of drawings]

The at diagram is a block diagram T1 showing an embodiment of the present invention.
...Power receiving transformer (3-phase, 3-wire). '1゛2......Power receiving transformer for electric lights (single phase 3 wire). 1.2, 4.5... Ungrounded electrical circuit, 3, 6
......Grounding circuit, 10.11...
・・・・・・Driving class 2 grounding work grounding wire, 9・・・・・・
... Monitoring device, 8 ......- Transmission section,
20...Receiving device, 15...
...Reception circuit. th/time

Claims (1)

[Claims] The second power transformer transforms high-voltage electricity into low-voltage electricity.
A low-frequency signal modulated by an alarm signal to be transmitted obtained from an insulation monitoring device, etc. is applied to the power low-voltage secondary power line through the grounding wire of the type 2 grounding work, and the second type By detecting and demodulating the low-frequency signal induced between the earth and the grounding line of a low-voltage line that has been grounded, high-voltage electricity is converted to low-voltage electricity. Transforming electric light transformer 2
A method for transmitting a supervisory signal, characterized in that the low-frequency signal does not enter equipment connected to the next-side electric circuit as a load and cause trouble.