CN106707088A - Two-way electric leakage detection circuit and detection device and method - Google Patents

Abstract

The invention discloses a two-way electric leakage detection circuit, comprising a fixed resistor R1 and a variable resistor R2 which are connected in series, wherein a first end of the fixed resistor R1 is led out as a first detection end, a second end of the variable resistor R2 is led out as a second detection end, and the second end of the fixed resistor R1 is connected with the first end of the variable resistor R2; the two-way electric leakage detection circuit further comprises a fixed resistor R3, wherein a first end of the fixed resistor R3 is connected with the first end of the variable resistor R2, and a second end of the fixed resistor R3 is grounded; when the two-way electric leakage detection circuit is used for electric leakage detection, the first detection end or the second detection end is connected with a positive electrode of a power supply system, and the detection end which is not connected with the positive electrode is connected with a negative electrode of the power supply system; and positive and negative two-way electric leakage detection can be achieved by adopting the circuit. A two-way electric leakage detection device comprises the two-way electric leakage detection circuit, a voltage sensor and a processor, wherein the processor carries out calculation according to a voltage value collected by the voltage sensor so as to detect whether the electricity leaks or not. The two-way electric leakage detection device is portable, and can be conveniently used anytime and anywhere. A two-way electric leakage detection method comprises the steps of detecting power supply voltage of the circuit according to the resistance values of the resistors R1, R2 and R3 and voltage at two ends of the resistor R1; calculating positive electric leakage resistance and negative electric leakage resistance; and judging whether electric leakage exists or not.

Description

Two-way electric-leakage detection circuit, detection means and method

Technical field

The present invention relates to a kind of technical field of insulation detection, it is related to a kind of two-way electric-leakage detection circuit, detection means and side Method.

Background technology

Insulation detection device is used for the detection of electrical leakage of power system, and the electric power system of every profession and trade is all needed with detection of electrical leakage Ask.

By taking power supply system of train as an example, because the earth-free DC power-supply system of non-grounded type is due to security higher And reliability, it is widely used in the electric power system of modern train.When floating neutral system occurs one point earth short circuit, do not formed Current path and influence the operation of whole system, so as to improve the continuity and reliability of electric power system, if floating neutral system When earth point can not find in time, when another one point earth or insulation are reduced, it would be possible to cause accident.Electric power system is normally row The guarantee of car safe operation, it is important during electric power system is run for how accurately detecting whether DC power-supply system leaks electricity Detection project.And its normal work is just can guarantee that, it is necessary to carry out two-way detection of electrical leakage for floating system.

Bridge balance principle being used traditional DC leakage detection method, using voltage detecting method to DC leakage situation more Detected.Bridge balance detection method has the following disadvantages：First：When train capacitance-resistance changes, it is impossible to amendment in real time Electric bridge parameter, influences accuracy of detection；Second：Main line two-way drain conditions simultaneously cannot be detected, i.e., cannot realize the positive leakage of circuit Electricity and negative sense are detected while electric leakage；3rd：If it is applied to train non-grounded type current leakage detection system, due to the shadow of line resistance Ring, the alarm of compartment distal end is not accurate enough, and normal electricity consumption and security monitoring to train bring certain hidden danger.

The content of the invention

It is an object of the invention to provide a kind of detection circuit with two-phase earth leakage detection functions, detection means and detection Method.

Present disclosure is：Two-way electric-leakage detection circuit, including the fixed resistance R being connected in series₁With variable resistor R₂, R₁First end draw, as the first test side, R₂The second end draw, as the second test side, R₁The second end and R₂ One end connects；Further include fixed resistance R₃, R₃First termination R₂First end, R₃Second end is grounded；During for detection of electrical leakage, First test side or the positive pole of the second detection termination electric power system, the test side connection power supply system of corresponding not connected positive pole The negative pole of system.

Preferably：R₂Including the resistance R that two resistances being connected in parallel are not waited₂₁With resistance R₂₂, resistance R₂₁With resistance R₂₂'s Switch is provided with branch road.

Preferably：Electric capacity C is further included, R is connected in parallel on₁Two ends.

Two-way earth detector, including above-mentioned detection circuit, also including detecting system, specifically include voltage sensor and Processor；The voltage sensor is used to gather resistance R₁Electricity between the voltage at two ends and the first test side and the second test side Pressure, and it is transferred to processor；The processor includes computing unit, and the magnitude of voltage to be fed back according to voltage sensor is calculated just To leak resistance, positive leakage current, negative sense leak resistance and negative sense leakage current.

Preferably：Also include housing, including housing, two-way electric-leakage detection circuit, voltage sensor and processor are arranged on In housing.LCDs is provided with housing, and processor communication, for showing testing result.

Preferably：Also include humidity sensor, for detecting ambient humidity and feeding back to processor；Also include data storage Unit, is the storage card connected with processor；Also include the communication module being connected with processor.

Preferably：The USB interface of interconnection is provided with processor and housing.

Preferably：Communication module is GPRS communication modules.

Two-way electrical leakage detecting method, comprises the following steps：

Record R₁、R₂、R₃Initial value, by the first test side or second detection termination DC power-supply system positive pole, Ling Yijian Termination DC power-supply system negative pole is surveyed, U is measured₁And U₀Value；

i₁=i₂+i₃；i₅=i₃+i₄；

Wherein, i₁It is R₁Branch current, i₂It is R₂Branch current, i₃It is R₃Branch current, i₄It is forward direction electric leakage equivalent resistance R_x Branch current, i.e., positive leakage current, i₅It is negative sense electric leakage equivalent resistance R_yBranch current, i.e. negative sense leakage current；

Bring resistance value and magnitude of voltage into above formula.Obtain：

Wherein, U_dIt is negative pole to the voltage of the earth, according to U₁And U₀Value, obtain U_d：

Adjustment R₂Resistance, and it is recorded as R'₂, record new measured value, U₁'、U'₀；

Above-mentioned calculation procedure is repeated, is obtained：

Wherein, U'_dIt is adjustment R₂Afterwards, voltage of the new negative pole of acquisition to the earth；

And then obtain：

Thus, can obtain following formula：

Wherein R_xIt is forward direction electric leakage equivalent resistance, R_yIt is negative sense electric leakage equivalent resistance.

Beneficial effects of the present invention are：

(1) the invention provides a kind of neutral ground electric-leakage detection circuit and electrical leakage detecting method, in conventional neutrality The feelings that the positive negative wire insulation against ground performance that improved on the basis of point earthing detection method can not alarm when declining simultaneously Condition, realizes the requirement of the electric leakage for detecting positive pole and negative pole simultaneously, improves the ability of DC power-supply system detection of electrical leakage, while The safe class that the quality analysis and electric energy that improve electricity consumption are used.

(2) two-phase electric leakage Simultaneous Detection solves traditional electrical leakage detecting method in DC power-supply system two-phase simultaneously Undetectable situation during electric leakage, improves accuracy low present situation in distal end when leaking electricity, and floating is realized with custom circuit The detection that the DC power-supply system two-phase of system is leaked electricity simultaneously, it is higher compared to traditional DC leakage detection method accuracy, in prison Control Electrical Safety, investigation leak current fault and carry out maintenance when leaking electricity and be significant.

(3) two-way earth detector portability is strong, can whenever and wherever possible carry out detection of electrical leakage.And detection means can preserve inspection Data are surveyed, detection data can be derived or be uploaded to the webserver by communication module, realize remote monitoring.

Brief description of the drawings

Fig. 1 is two-way electric-leakage detection circuit structural representation in the case of leakproof；

Fig. 2 is two-way detection of electrical leakage equivalent circuit structure schematic diagram under drain conditions；

Detection of electrical leakage equivalent circuit theory schematic diagram when Fig. 3 is for detection electric leakage；

Fig. 4 is two-way earth detector structural representation；

Fig. 5 is two-way earth detector structural representation.

Wherein：1- housings, 2- LCDs, 3- handles, 4- antennal interfaces

Specific embodiment

Specific embodiment of the invention is clearly fully described by below with reference to accompanying drawing.Obviously, it is embodied Embodiment described by mode is only a part of embodiment of the invention, rather than whole embodiments.Based in the present invention Embodiment, the every other embodiment that those of ordinary skill in the art are obtained on the premise of creative work is not made, Belong to protection scope of the present invention.

It is an object of the invention to provide a kind of insulation detecting circuit, insulation detection device device and method, using the dress Putting can realize positively and negatively two-way detection of electrical leakage with method, for example, can be used for the two-way electric leakage inspection of train floating ground electric power system Survey.

Two-way electric-leakage detection circuit includes：The fixed resistance R being connected in series₁With variable resistor R₂, fixed resistance R₁First End is drawn, used as the first test side, variable resistor R₂The second end draw, as the second test side.Resistance R₁The second end and electricity Resistance R₂First end connect.Detection circuit also includes fixed resistance R₃, R₃First terminating resistor R₂First end, R₃Second end is grounded. During for detection of electrical leakage, the positive pole of the first test side or the second detection termination electric power system, one end of corresponding not connected positive pole Connect the negative pole of electric power system.As shown in figure 1, not occur under drain conditions, detecting electrical block diagram.

R₂Adjustable resistance can be used, following structure can be also used：R₂Including the resistance that two resistances being connected in parallel are not waited R₂₁With resistance R₂₂, resistance R₂₁With resistance R₂₂Branch road on be provided with switch.Resistance R can be selected according to demand₂₁Branch road connects Enter, resistance R₂₂Branch road is accessed or two branch roads are accessed, and realizes changing the effect for accessing resistance.

Two-way electric leakage insulation detecting circuit further includes electric capacity C₁, it is connected in parallel on fixed resistance R₁Two ends, its Main Function is Leach DC voltage ripple, it is ensured that the precision of testing result.

As shown in Figure 3 and Figure 4, two-way earth detector, in addition to including detection circuit, further comprises detection system System, the detecting system includes voltage sensor and processor.

Voltage sensor：For gathering resistance R₁The voltage U at two ends₁, while also gathering the first test side and the second test side Between voltage U₀, i.e. supply voltage.

Processor：Including computing unit, the magnitude of voltage to be fed back according to voltage sensor calculates positive leak resistance, just To leakage current, negative sense leak resistance and negative sense leakage current.In the present embodiment, processor uses arm processor.

In order that insulation detection device is more portable, housing 1 is further designed, insulation detecting circuit and detecting system are respectively provided with In housing 1.Housing 1 is made using ABS resin material, with nontoxic, heat-resisting, case hardness is high, chemical-resistance and electricity The characteristics of performance etc. is good.The surface of housing 1 is provided with LCDs 2, as human-computer interaction interface, for showing detector Working condition and detection value information.The side wall of housing 1 is provided with handle 3, and handle 3 is held during carrying, embodies insulation tester just The property taken.

Further detecting system also includes humidity sensor, and humidity sensor is used to detect working environment humidity, and will inspection Data transfer to processor is surveyed, processor judges that detected value working environment is too high with the presence or absence of humidity according to humidity value, and influence is exhausted The risk of edge detector normal work.

Further detecting system also includes data storage cell, including data storage card, and row data communication is entered with processor. SD card is used in the present embodiment, SPI interface is configured with processor, SD card is through SPI interface and processor communication.

Further detecting system also includes data download unit, and USB interface is provided with detector housing 1, can circumscribed USB Storage device, realizes download of the data by SD card to storage device.

Further detecting system also includes communication unit, is communicated with the webserver.Antenna is provided with detector housing 1 Interface 4, can external GPRS antenna, specifically, can by the webserver that is uploaded to of detection data, and further realize with far Row data communication is entered at process control end, to realize remote monitoring.User can click on the storage button of LCDs, then data from It is dynamic to store to SD card, and it is sent to the webserver.In the present embodiment, communication system uses GPRS communication systems, as an alternative Implementation method, also can be using the other kinds of communication mode such as radio communication.

Being illustrated in figure 2 in the case where there are drain conditions, detecting the equivalent circuit of circuit.In forward direction electric leakage, the first detection It is equivalent between end and earth terminal to form positive electric leakage equivalent resistance R_x；When negative sense leaks electricity, between earth terminal and the second test side Equivalent formation negative sense electric leakage equivalent resistance R_y.It should be noted that positive electric leakage equivalent resistance R_xWith negative sense electric leakage equivalent resistance R_y Can exist with individualism or, it depends on only positive electric leakage, only negative sense electric leakage or the two-way electric leakage of positive negative sense.

With reference to Fig. 2, the Main Function of processing unit is the U gathered according to voltage acquisition unit₁、U₀Value, calculates positive electric leakage Equivalent resistance R_xWith negative sense electric leakage equivalent resistance R_y；Positive leakage current i can also further be calculated₄With negative sense leakage current i₅。

Based on two-way electric-leakage detection circuit and two-way earth detector, it is further provided a kind of two-way detection of electrical leakage side Method.

As shown in figure 3, when carrying out detection of electrical leakage using two-way electric-leakage detection circuit or detection means, there is the situation of electric leakage Under, current direction schematic diagram.Two-way electrical leakage detecting method, comprises the following steps：

Computing unit obtains first group of R₁、R₂、R₃、U₁、U₀Value, wherein, R₁And R₃It is fixed resistance value, its resistance is known Fixed value, R₂It is variable resistance, is recorded after adjustment is fixed, if R₂Using the building form of two resistor coupled in parallel, detect for the first time When, make resistance R₂₁Branch road is accessed, resistance R₂₂Branch road disconnects, U₁、U₀Value is detected and fed back by voltage acquisition unit.

According to Kirchhoff's current law (KCL)：

i₁=i₂+i₃；(1)

i₅=i₃+i₄；(2)

Wherein, i₁It is R₁Branch current, i₂It is R₂Branch current, i₃It is R₃Branch current, i₄It is forward direction electric leakage equivalent resistance R_x Branch current (forward leakage current), i₅It is negative sense electric leakage equivalent resistance R_yBranch current (negative sense leakage current).

Resistance value and magnitude of voltage are brought into formula (1) and formula (2), so as to obtain following formula：

Wherein, U_dIt is negative pole to the voltage of the earth, according to U₁And U₀Value, obtain U_d：

Obtain first group of R₁、R'₂、R3、U₁'、U'₀Value, wherein, R₁It is fixed resistance value with R3, its resistance is constant, with first Data in group are equal, R₂It is variable resistance, it is by R after adjustment₂Resistance, make its with first group in record resistance not It is same to obtain new R'₂.If R₂Using the building form of two resistor coupled in parallel, when detecting for the first time, make resistance R₂₂Branch road is accessed, resistance R₂₁Branch road disconnects, due to R₂Resistance change, U₁And U₀Value will change, it is therefore possible for the detected that a new U₁'、U'₀Value, and Detected by voltage acquisition unit and fed back.

By formula (4) and formula (7) composition equation group, obtain：

Thus, can obtain following formula：

If having calculated R_xThen prove there is positive electric leakage, if having calculated R_yThen prove there is negative sense electric leakage, will be logical Cross housing liquid crystal display display detection of electrical leakage result.

Obtain R_xAnd R_yAfterwards, can also further be calculated：

Finally, positive leakage current i is obtained₄With negative sense leakage current value i₅, its can also reflect the positive electric leakage of electric power system and Negative sense electric leakage situation.If calculating positive leakage current, prove to be leaked electricity in the presence of positive, if calculating negative sense electric leakage electricity Stream, then prove there is negative sense electric leakage.Detection of electrical leakage result will be shown by housing liquid crystal display.

Claims (10)

1. two-way electric-leakage detection circuit, it is characterised in that：Including the fixed resistance R being connected in series₁With variable resistor R₂, R₁ One end is drawn, used as the first test side, R₂The second end draw, as the second test side, R₁The second end and R₂First end phase Connect；Further include fixed resistance R₃, R₃First termination R₂First end, R₃Second end is grounded；During for detection of electrical leakage, the first inspection The positive pole of end or the second detection termination electric power system is surveyed, a test side for being not connected with positive pole connects the negative pole of electric power system.

2. two-way electric-leakage detection circuit as claimed in claim 1, it is characterised in that：R₂Including two resistances being connected in parallel not Deng resistance R₂₁With resistance R₂₂, resistance R₂₁With resistance R₂₂Branch road on be provided with switch.

3. two-way electric-leakage detection circuit as claimed in claim 1, it is characterised in that：Electric capacity C is further included, R is connected in parallel on₁Two End.

4. two-way earth detector, using the two-way electric-leakage detection circuit described in claim 1, it is characterised in that：Also include Detecting system, specifically includes voltage sensor and processor；The voltage sensor is used to gather resistance R₁The voltage at two ends and Voltage between first test side and the second test side, and it is transferred to processor；The processor includes computing unit, to root The magnitude of voltage fed back according to voltage sensor calculates positive leak resistance, positive leakage current, negative sense leak resistance and negative sense and leaks electricity Electric current.

5. two-way earth detector as claimed in claim 4, it is characterised in that：Also include housing, two-way detection of electrical leakage electricity Road, voltage sensor and processor are arranged in housing, and LCDs is provided with housing, and processor communication, for showing Show testing result.

6. two-way earth detector as claimed in claim 5, it is characterised in that：Also include humidity sensor, for detecting Ambient humidity simultaneously feeds back to processor；Also include data storage cell, be the storage card connected with processor；Also include and treatment The connected communication module of device.

7. two-way earth detector as claimed in claim 5, it is characterised in that：Interconnection is provided with processor and housing USB interface.

8. two-way earth detector as claimed in claim 6, it is characterised in that：The communication module is GPRS communication moulds Block.

9. two-way electrical leakage detecting method, is examined using the two-way electric leakage described in the two-way electric-leakage detection circuit or 3 described in claim 1 Survey device, it is characterised in that comprise the following steps：

Record R₁、R₂、R₃Initial value, by the first test side or second detection termination DC power-supply system positive pole, another test side DC power-supply system negative pole is connect, U is measured₁And U₀Value；

i₁=i₂+i₃；

i₅=i₃+i₄；

Wherein, i₁It is R₁Branch current, i₂It is R₂Branch current, i₃It is R₃Branch current, i₄It is forward direction electric leakage equivalent resistance R_xBranch road Electric current, i.e., positive leakage current, i₅It is negative sense electric leakage equivalent resistance R_yBranch current, i.e. negative sense leakage current；

Bring resistance value and magnitude of voltage into above formula.Obtain：

$\frac{U_1}{R_1}=\frac{U_0-U_1}{R_2}+\frac{U_0-U_1-U_d}{R_3};$

$\frac{U_d}{R_y}=\frac{U_0-U_1-U_d}{R_3}+\frac{U_0-U_d}{R_x}=\frac{(U_0-U_1-U_d)*R_x}{R_3{R}_x}+\frac{(U_0-U_d)*R_3}{R_3{R}_x};$

Wherein, U_dIt is negative pole to the voltage of the earth, according to U₁And U₀Value, obtain U_d：

$U_d=U_0-U_1-(\frac{U_1}{R_1}-\frac{U_0-U_1}{R_2})\×R_3;$

Adjustment R₂Resistance, and it is recorded as R'₂, record new measured value, U₁'、U'₀；

Above-mentioned calculation procedure is repeated, is obtained：

$\frac{U_1^{\′}}{R_1}=\frac{U_0^{\′}-U_1^{\′}}{R_2^{\′}}+\frac{U_0^{\′}-U_1^{\′}-U_d^{\′}}{R_3};$

$\frac{U_d^{\′}}{R_y}=\frac{U_0^{\′}-U_1^{\′}-U_d^{\′}}{R_3}+\frac{U_0^{\′}-U_d^{\′}}{R_x}=\frac{(U_0^{\′}-U_1^{\′}-U_d^{\′})*R_x}{R_3{R}_x}+\frac{(U_0^{\′}-U_d^{\′})*R_3}{R_3{R}_x};$

Wherein, U'_dIt is adjustment R₂Afterwards, voltage of the new negative pole of acquisition to the earth；

And then obtain：

$\frac{U_d}{U_d^{\′}}=\frac{(U_0-U_1-U_d)\×R_x+(U_0-U_d)\×R_3}{(U_0^{\′}-U_1^{\′}-U_d^{\′})\×R_x+(U_0^{\′}-U_d^{\′})\×R_3};$

Thus, can obtain positive electric leakage equivalent resistance R_xWith negative sense electric leakage equivalent resistance R_y：

$R_x=\frac{U_d\×(U_0^{\′}-U_d^{\′})\×R_3-U_d^{\′}\×(U_0-U_d)\×R_3}{U_d^{\′}\×(U_0-U_1-U_d)-U_d\×(U_0^{\′}-U_1^{\′}-U_d^{\′})};$

$R_y=\frac{U_d}{\frac{U_0-U_1-U_d}{R_3}+\frac{U_0-U_d}{R_x}}.$

10. two-way electrical leakage detecting method as claimed in claim 9, it is characterised in that：It is further comprising the steps of：According to acquisition R_x And R_yAfterwards, calculate：

$i_4=\frac{U_0-U_d}{R_x};$

$i_5=i_1-i_2+i_4=\frac{U_1}{R_1}-\frac{U_1-U_d}{R_2}++i_4;$

Finally, positive leakage current i is obtained₄With negative sense leakage current value i₅。