CN201845060U

CN201845060U - Electric leakage position detector for low-voltage distribution line

Info

Publication number: CN201845060U
Application number: CN2009203523195U
Authority: CN
Inventors: 董卫国; 张燕杰; 李宏文; 沈金波
Original assignee: INSTITUTE OF BUILDING FIRE SAFETY CHINA ACADEMY OF BUILDING RESEARCH; BEIJING HAIPPO ZHIHENG ELECTRICAL FIRE-PROOF TECHNOLOGY Co Ltd
Current assignee: INSTITUTE OF BUILDING FIRE SAFETY CHINA ACADEMY OF BUILDING RESEARCH; BEIJING HAIPPO ZHIHENG ELECTRICAL FIRE-PROOF TECHNOLOGY Co Ltd
Priority date: 2009-12-23
Filing date: 2009-12-23
Publication date: 2011-05-25
Anticipated expiration: 2019-12-23

Abstract

The utility model provides an electric leakage position detector for a low-voltage distribution line. The detector emits a series of electric pulse signals at a test point, generates an echo when the electric pulse signals encounter an electric leakage point, and transmits the echo back to the test point to obtain the velocity of the electric pulse in a wire, so that the distance from the test point to the electric leakage point can be calculated, and the position of the electric leakage point can be accurately found out if the time difference between the echoing time and the pulse transmitting time is measured. When the detector works, a pulse generator generates a series of narrow pulses, and a pulse transmitting module transmits a series of amplified pulses from the test point to the two wires to be tested, then intermittently stops, and waits for receiving the echo. The round trip time of the pulse is ts, the path length S of an electric wave can be calculated according to the formula S=V*ts/2, wherein, V is light velocity, V=3*108 m/s. As the path is the round trip of the electric pulse, the time ts is divided by 2, and finally the calculated result is the real distance S from the test point to the electric leakage point.

Description

Low-voltage distributing line electric leakage position detector

Technical field:

The utility model belongs to the electric fireproof security monitoring field in the low-voltage electric system.Its objective is the problem that electric leakage particular location difficulty is sought in electric leakage later on that in low-voltage distribution system, takes place at present that solves.

Background technology:

Up to the present, accurately the method for detecting leakage position still adopts the artificial visually examine or adopt the way of progressively measuring at different nodes with multimeter after outage in low-voltage distribution system, does not also have a kind of method that adopts electric signal accurately to measure leakage.Therefore the utility model provides new method and apparatus when seeking leak current fault point position in low-voltage distribution system.

Summary of the invention:

A kind of low-voltage distributing line electric leakage position detector, its ultimate principle is: send discontinuous electric impulse signal in test point, when running into leakage, this pulse can produce echo, and to being back to test point, as long as the mistiming when measuring echo and sending pulse, just can calculate the distance from the test point to the leakage, thereby find out the position of leakage.

The formation of low-voltage distributing line electric leakage position detector mainly is made up of pulse producer 1, transmitter module 2, receiver module 3, pulse shielding 4, microprocessor 5, memory circuit 6, numeral demonstration 7 and control knob 8 etc., sees shown in Figure 1.

Pulse producer 1 sends after the pulse, transmit in cable conductor by transmitter module 2, when pulse signal runs into short dot, pulse signal passes through another lead of cable to passback by short dot, transfer back to receiver module 3 through extra pulse shielding 4, the effect of shielded signal is to prevent that receiver module 3 from receiving transponder pulse, prevents its interference when transmitter module 2 transponder pulses.The velocity of propagation of electric pulse in lead is 0.3 meter every nanosecond, pulse echo that receiver module 3 receives and transponder pulse carry out time ratio in microprocessor 5, can calculate the mistiming Ts that sends pulse and echo, see shown in Figure 2, the speed of being propagated in lead by electric pulse can calculate the distance of cable short circuit point, can find the particular location of leakage in the lead.

Description of drawings:

Figure 1 shows that structure of the present utility model: 1,9 parts such as pulse producer 2, pulse transmitter module 3, reception of impulse module 4, emission shroud module 5, microcontroller circuit 6, memory circuit 7, numeral demonstration 8, control knob 9, power circuit.

Figure 2 shows that transponder pulse, shielding pulse and echo three portion waveshapes.

Embodiment:

The utility model when work a string burst pulse takes place by pulse producer 1 and by pulse transmitter module 2 by the pulse from test point is sent a succession of amplification to two tested leads after, intermittently, stop the transponder pulse ripple then, wait for receiving echo.Because pulse train can be received module 3 and receive when emission, so when emission, shield,, open shroud module 4 at once when emission one finishes by 4 pairs of receiving circuits of shroud module, make receiver be in normal accepting state.Because leakage is exactly the short dot of lead,, just can calculate the path length that electric wave is passed by as long as measure the time that pulse sends and return so the pulse train electric wave will produce echo in this point.

As seen from Figure 2, the pulse train that pulse transmitter module 2 sends is transported in the cable that has short trouble, during transponder pulse, shields 4 circuit by pulse receiving circuit module 3 is temporarily shielded, make receiving circuit can not directly receive the pulse that transmitter module 2 sends, prevent its interference; Behind the end-of-pulsing that sends, the shielding pulse also finishes simultaneously, receiver module work, the pulse echo that reception is returned from cable can calculate, and emission begins to the time ts that receives between first echo, because be two-way time, so also will be divided by 2, the time from the test point to the short dot is ts/2, according to formula: S=VT wherein V be that the light velocity is: 3 * 10 ⁸Meter per second, the time is ts/2,, then can calculate apart from S.

Claims

1. a low-voltage distributing line electric leakage position detector is characterized in that compositions such as pulse producer (1), transmitter module (2), receiver module (3), microprocessor (5) and peripheral circuit thereof.

2. according to claims 1 described low-voltage distributing line electric leakage position detector, it is characterized in that having pulse shielding (4).

3. according to the described low-voltage distributing line electric leakage of claims 1 position detector, it is characterized in that having microprocessor (5), memory circuit (6), numeral show parts such as (7).