CN211856853U

CN211856853U - Electric leakage detection loop

Info

Publication number: CN211856853U
Application number: CN202020443725.9U
Authority: CN
Inventors: 都国权; 刘光庆
Original assignee: Shanghai Quanxiang Electric Technology Co ltd
Current assignee: Shanghai Quanxiang Electric Technology Co ltd
Priority date: 2020-03-31
Filing date: 2020-03-31
Publication date: 2020-11-03
Anticipated expiration: 2030-03-31

Abstract

The utility model discloses a leakage detection return circuit, the protection is synthesized measuring and control device three-phase reactor electric connection leak hunting module, it includes the U0 output to pick up the hourglass module, RJ signal output part, C1 end, C2 end and ground wire end, C1 or C2 are connected with ground wire end ground connection, the protection is synthesized measuring and control device and is included U0 input, the electric leakage input, the earthing terminal, I0 end and IN end, the U0 input of the protection is synthesized measuring and control device, the electric leakage input, the earthing terminal respectively with the U0 output of picking up the hourglass module, RJ signal output part, the ground wire end corresponds electric connection, the I0 end and the IN end and the zero sequence transformer electric connection of the protection synthesis measuring and control device, one of them looks electric connection R8 resistance IN proper order of three phase power, SB1 simulates the electric leakage button, the ground. The utility model discloses the electric leakage detection return circuit adopts the megawatt resistance-capacitance mode to gather zero sequence voltage, and the reliability is high, and the cost aspect is than adopting zero sequence transformer to gain the zero sequence voltage and want much lower.

Description

Electric leakage detection loop

Technical Field

The utility model relates to a detection return circuit specifically is an electric leakage detection return circuit.

Background

The coal mine has narrow underground space, unfavorable heat dissipation, moist air, flammable and explosive gas and coal dust, and strict protection measures must be taken for electric leakage which can generate electric sparks under the special production environment.

In a leakage detection circuit of a power direction type leakage protection device adopted at present, a zero sequence transformer is connected between a neutral point of a three-phase reactor and the ground in series to detect zero sequence voltage. RC oscillation, leakage protection and selective leakage protection are easy to occur, and instantaneous sampling distortion occurs, so that the action time of a leakage protection function is too long; when an electric shock accident happens, the brake can not be timely released to play a role in protection. When the capacitor is broken down, the neutral point of the three-phase power is grounded due to too small internal resistance of the zero-sequence transformer, so that the leakage protection function is invalid. Moreover, the zero sequence transformer has complex process, high cost, serious waste and is not beneficial to environmental protection.

When a cable at a switch incoming line end has no distributed capacitance value, zero-sequence current of a leakage detection circuit of the power direction type leakage protection device adopted at present is almost zero. The leak detection circuit cannot effectively perform power direction type leak detection.

It can thus be seen that there is a need in the art for a low pressure leak detection apparatus that addresses the above-mentioned problems.

Disclosure of Invention

An object of the utility model is to provide an electric leakage detection return circuit to solve the problem that proposes in the above-mentioned background art.

In order to achieve the above object, the utility model provides a following technical scheme:

the utility model provides a leakage detection return circuit, three-phase reactor including electric connection three phase power, the leak hunting module, measurement and control device and zero sequence mutual inductor are synthesized IN the protection, measurement and control device three-phase reactor electric connection leak hunting module is synthesized IN the protection, the leak hunting module includes U0 output, RJ signal output part, C1 end, C2 end and ground terminal, C1 or C2 and ground terminal ground connection are connected, the measurement and control device is synthesized IN the protection includes U0 input, the electric leakage input end, the earthing terminal, I0 end and IN end, the U0 input of the measurement and control device is synthesized IN the protection, the electric leakage input end, the earthing terminal respectively with the U0 output of leak hunting module, the RJ signal output end, the ground terminal corresponds electric connection, the I0 end and the IN end of the measurement and control device are synthesized IN the protection and zero sequence mutual inductor electric connection, one of three phase power is electric connection R8 resistance.

Compared with the prior art, the beneficial effects of the utility model are that: the utility model discloses the electric leakage detection return circuit adopts the megawatt resistance-capacitance mode to gather zero sequence voltage, and the reliability is high, and the cost aspect is than adopting zero sequence transformer to gain the zero sequence voltage and want much lower. The utility model discloses the electric leakage detection return circuit adds adjustable condenser to ground in three-phase reactor neutral point position, can compensate according to the not enough condition of cable distribution capacitance on the spot. The defect that the leakage detection circuit cannot perform power direction type leakage protection due to insufficient distributed capacitance in the power supply cable can be effectively overcome.

Drawings

Fig. 1 is a schematic structural diagram of a leakage detection circuit.

In the figure: the device comprises a 1-three-phase reactor, a 101-three-phase power supply, a 2-leakage detection module, a 3-protection comprehensive measurement and control device, a 4-zero sequence transformer, a 5-R8 resistor and a 6-SB1 analog leakage button.

Detailed Description

The technical solution of the present patent will be described in further detail with reference to the following embodiments.

Example 1

Referring to fig. 1, a leakage detection circuit includes a three-phase reactor 1 electrically connected to a three-phase power source 101, a leakage detection module 2, a comprehensive protection measurement and control device 3 and a zero-sequence transformer 4, the comprehensive protection measurement and control device 3 is electrically connected to the three-phase reactor 1 and the leakage detection module 2, the leakage detection module 2 includes a U0 output terminal, an RJ signal output terminal, a C1 terminal, a C2 terminal and a ground terminal, the C1 or the C2 is grounded to the ground terminal, the comprehensive protection measurement and control device 3 includes a U0 input terminal, a leakage input terminal, a ground terminal, an I0 terminal and an IN terminal, the U0 input terminal, the leakage input terminal and the ground terminal of the comprehensive protection measurement and control device 3 are electrically connected to the U0 output terminal, the RJ signal output terminal and the ground terminal of the leakage detection module 2, the I0 terminal and the IN terminal of the comprehensive protection measurement and control device 3 are electrically connected to the zero-sequence transformer 4, SB1 simulates leaky button 6, ground.

The utility model discloses a theory of operation is: when the protective comprehensive measurement and control device 3 selects the setting of the branch switch, and the SB1 simulation leakage button 6 is pressed to perform the simulation leakage test, the neutral line to ground balance of the three-phase reactor 1 is broken and zero sequence voltage occurs. The direct megaresistance-capacitance detection module of the pin N and the pin U0 in the novel leakage detection loop 2 can send the zero-sequence voltage after voltage reduction and filtering processing into the comprehensive protection measurement and control device 3, and the amplitude and phase signals of the zero-sequence voltage U0 are obtained through the pin 15; the zero sequence current transformer 4 forms a zero sequence current loop through the R8 resistor 5 to obtain a zero sequence current, and sends the zero sequence current to the 13 th and 14 th pins of the comprehensive protection measurement and control device 3 to obtain an amplitude value and a phase signal of a zero sequence current signal I0. The CPU of the comprehensive protection measurement and control device 3 judges whether the R8 resistor 5 meets the selective leakage protection condition to perform leakage action or refusal action according to the amplitudes and phase differences of U0 and I0;

when the zero-sequence current transformer 4 can hardly detect zero-sequence current, the amplitude judgment and the direction type selection of the effective selective leakage protection function can not be performed. At the moment, C1 or C2 in the novel leakage detection circuit 2 is in short circuit with the ground leg; capacitance compensation is connected between the neutral point of the artificial re-zero sequence mutual inductor 4 and the ground to form a through-flow loop, so that the size and the effective waveform of a zero sequence current signal can be effectively enhanced;

when the protective comprehensive measurement and control device 3 selects the setting of a main switch and the SB1 simulation leakage button 6 is pressed down to perform a simulation leakage test, an additional direct-current voltage signal is added between pins 17 and 16 of the feed comprehensive protective measurement and control device 3, and the accurate leakage resistance value of the R8 resistor 5 is obtained by comparing the current-limiting voltage-dividing resistor between the N pin and the RJ pin in the novel leakage detection loop 2 with the R8 resistor 5 in a voltage-dividing manner; on the condition that the resistance value of the R8 resistor 5 is equal to the leakage protection condition, it is determined whether the leakage operation or the rejection operation is performed.

It is obvious to a person skilled in the art that the invention is not restricted to details of the above-described exemplary embodiments, but that it can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.

Claims

1. A leakage detection loop is characterized by comprising a three-phase reactor (1) electrically connected with a three-phase power supply (101), a leakage detection module (2), a comprehensive protection measurement and control device (3) and a zero-sequence transformer (4), wherein the comprehensive protection measurement and control device (3) is electrically connected with the three-phase reactor (1) and the leakage detection module (2), the leakage detection module (2) comprises a U0 output end, an RJ signal output end, a C1 end, a C2 end and a ground wire end, the C1 or the C2 is grounded with the ground wire end, the comprehensive protection measurement and control device (3) comprises a U0 input end, a leakage input end, a grounding end, an I0 end and an IN end, the U0 input end, the leakage input end and the grounding end of the comprehensive protection measurement and control device (3) are respectively and electrically connected with the U0 output end, the RJ signal output end and the ground wire end of the leakage detection module (2) correspondingly, the I0 end, one phase power supply of the three-phase power supply (101) is electrically connected with the R8 resistor (5), the SB1 analog leakage button (6) and the ground terminal in sequence.