CN202957571U - Electric leakage detection circuit for single-phase power supply of isolated neutral system - Google Patents
Electric leakage detection circuit for single-phase power supply of isolated neutral system Download PDFInfo
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- CN202957571U CN202957571U CN 201220686586 CN201220686586U CN202957571U CN 202957571 U CN202957571 U CN 202957571U CN 201220686586 CN201220686586 CN 201220686586 CN 201220686586 U CN201220686586 U CN 201220686586U CN 202957571 U CN202957571 U CN 202957571U
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Abstract
The utility model relates to an electric leakage detection circuit, in particular to an electric leakage detection circuit applied to a single-phase power supply of an isolated neutral system. A rectifier diode is connected with each of the two electrodes of the single-phase power supply. A sampling unit is connected between the two rectifier diodes and the ground. The output end of the sampling unit is connected with a comparative output unit which is connected with a relay triggering unit. By the structure, a detection mutual inductor is eliminated, and a voltage driving logic circuit of which electric leakage voltage is in a half-wave rectifier circuit in case of electric leakage of the power supply is directly used for finishing detection, so that cost is saved. In addition, misoperation phenomena caused by voltage floating are reduced, and the power supply safety of a mine is improved.
Description
Technical field
The utility model relates to a kind of electric-leakage detection circuit, particularly a kind of electric-leakage detection circuit that is applicable to the isolated neutral system single phase poaer supply.
Background technology
The 127V power supply is used for illumination and communication apparatus power supply under the coal mine, because subsurface environment is more abominable, cable insulation reduction or electric leakage accident occur easily and endangers personal safety.Therefore more and more higher to the detection performance requirement of comprehensive protection device, when particularly line voltage changed-25% ~+20% scope in, claimed device still can normal power supply, and when fault protector energy regular event.
Existing 127V earth leakage protective device mostly adopts and detects the zero sequence variable quantity that produces when reduction or electric leakage are insulated in the instrument transformer detection, variable quantity is sent into logic judgement or modulate circuit again and is sent into the single-chip microcomputer processing again.Testing circuit is complicated, and is larger for device precision degree of dependence.To last processing, more signal intensity number of times is arranged from detecting instrument transformer.Each device may exist it to detect error.Finally cause the at double amplification of error.May cause in the generation of protector malfunction when reducing or misaction of leaking electricity or insulate.
Summary of the invention
The utility model technical issues that need to address provide the electric-leakage detection circuit that a kind of mine is used power supply.
For solving above-mentioned technical problem, the two poles of the earth of the described single phase poaer supply of the utility model isolated neutral system single phase poaer supply electric-leakage detection circuit respectively are connected with a rectifier diode, be connected with sampling unit between described two rectifier diodes and the ground, the output of described sampling unit is connected with the comparison output unit, and described relatively output unit is connected with the relay trigger element;
Wherein, described sampling unit comprises the series circuit of sampling resistor and divider resistance, and described sampling resistor two ends are parallel with filter capacitor, and the tie point of described sampling resistor and divider resistance is the sampling output;
Described relatively output unit comprises the first comparator, and the input of described the first comparator is connected with the sampling output;
Described relay trigger element comprises direct current relay and switch triode, and the collector electrode of described switch triode is connected with direct current relay, and the base stage of described switch triode is connected with the first comparator output terminal.
Further, be connected with holding unit between described switch triode and the comparison output unit, be connected with the triggering holding unit between described holding unit and the comparison output unit;
Described holding unit comprises the 3rd comparator, and the output of described the 3rd comparator is by the resistance formation positive feedback that is connected with input;
Described triggering holding unit comprises the second comparator, and the input of described the second comparator is connected with the first comparator output terminal, and the output of described the second comparator is connected with the 3rd comparator input terminal.
Further, connect the utmost point between described triggering holding unit and the comparison output unit partition optocoupler is arranged.
Further, described direct current relay fly-wheel diode in parallel.
After adopting said structure, the utility model circuit is directly with 127V voltage access baffle, and when cable insulation was normal, the rectification effective value of the rectification circuit in the circuit was zero.When the insulation variation occured circuit, according to the variation of cable insulation degree, the step-down that produces at sample resistance in the half-wave rectifying circuit constantly changed.The insulation situation of change that has directly reflected circuit.To take a sample pressure drop taking-up and benchmark relatively, finally cause the upset of logic gates.Accurately, reliable, in this circuit, there is the variable quantity of three linearities can guarantee the normal reliable upset of circuit.One is that the variation of cable insulation against ground degree can be directly so that the variation of voltage on the sample resistance.Also have one to be that the unsteady variable quantity of voltage can be so that the benchmark generation linear change of gate circuit.Last be the variable quantity that floats of voltage can be directly so that sampling voltage change.So the sampling aspect is the fully direct variable quantity of obtaining insulation.The signal number of transitions is few, and almost without intermediate computations, error is little, and device precision degree of dependence is low.So that this circuit operation is reliable.The more important thing is and solved in the unsteady situation of voltage the Accidental occurrence of protector tripping and malfunction during for cable leakage.This circuit theory is simple, reliable in action, and detected value is not changed by voltage fluctuation.Saved the detection instrument transformer, when directly utilizing power supply that electric leakage occurs, the rectification changes in balance amount in the circuit drives logical circuit and finishes detection, saves cost.Simultaneously, reduced the nonaction that floats and produce because of voltage, the fail safe that has improved mine power supply.
Description of drawings
Below in conjunction with the drawings and specific embodiments the utility model is described in further detail.
Fig. 1 is the circuit theory diagrams of the utility model the first execution mode.
Fig. 2 is the circuit theory diagrams of the utility model the second execution mode.
Among the figure: 1 is single phase poaer supply, and 2 is sampling unit, and 3 for comparing output unit, and 4 for triggering holding unit, and 5 is holding unit, and 6 is the relay trigger element, and 7 is the first comparator, and 8 is the second comparator, and 9 is the 3rd comparator
Embodiment
Execution mode one:
As shown in Figure 1, the two poles of the earth of the described single phase poaer supply 1 of the utility model isolated neutral system single phase poaer supply electric-leakage detection circuit respectively are connected with a rectifier diode, i.e. rectifier diode V1 and V2 among Fig. 1, and single phase poaer supply 1 adopts down-hole 127V general AC power supply.Be connected with sampling unit 2 between described two rectifier diode V1 and V2 and the ground, described sampling unit comprises the series circuit of sampling resistor R4 and divider resistance, and in order to obtain the resistance of needs, divider resistance is the series resistance of resistance R 3 and R31 here.Described sampling resistor R4 two ends are parallel with filter capacitor, and filter capacitor is the shunt capacitance group of electrochemical capacitor C9 and C10, and the tie point of described sampling resistor R4 and resistance R 31 is the sampling output.
The output of described sampling unit is connected with comparison output unit 3, and described relatively output unit comprises the first comparator 7, and the input 7 of described the first comparator is connected with the sampling output.The reference voltage of the first comparator 7 is the series connection dividing potential drop of resistance R 5, R6 and power supply VJ, and the intermediate connection point of resistance R 5 and R6 is connected with reference voltage input.
Described relatively output unit 3 is connected with relay trigger element 6; Described relay trigger element 6 comprises direct current relay KS1 and switch triode VT1, and the collector electrode of described switch triode VT1 is connected with direct current relay KS1, and the base stage of described switch triode is connected with the first comparator 7 outputs.
The operation principle of the utility model single phase poaer supply electric-leakage detection circuit is as follows: in the time of the circuit leakproof, any variation can not occur in two diode rectification balances, and sampling unit 2 can not obtain sampled signal yet.When Leaked Current of Line to Ground occured in supply line, electric leakage place can produce leak resistance, and rectification circuit has just become halfwave rectifier.Like this R3, R4, the upper voltage drop that halfwave rectifier can occur of R31, this voltage drop is taken out in proportion as driving signal, it is direct current signal that filter capacitor C9, C10 will drive signal rectification, and this direct current signal is input to comparison input unit 3 as the logic comparison signal.With the reference voltage of the first comparator 7 relatively after, the output high level, high level driving switch triode VT1 is so that triode VT1 conducting, like this so that direct current relay KS1 adhesive so that peripheral circuit disconnects, is protected peripheral circuit.
Further, for after detecting electric leakage, so that relay remains on the state of adhesive, the state that peripheral circuit is remained open; Until be checked through electric leakage place and process rear hand-reset.So, need to switch triode VT1 with relatively is connected holding unit 5 between the output unit 3, be connected with triggering holding unit 4 between described holding unit 5 and the comparison output unit 3.
Described holding unit 5 comprises the 3rd comparator 9, and the output of described the 3rd comparator is by the resistance formation positive feedback that is connected with input, and resistance is the series resistance of R17 and R18 here.Described triggering holding unit 4 comprises the second comparator 8, and the input of described the second comparator 8 is connected with the first comparator 7 outputs, and the output of described the second comparator 8 is connected with the 3rd comparator 9 inputs.The reference voltage of the second comparator 8 is the series connection dividing potential drop of resistance R 11, R12 and power supply VC, and the intermediate connection point of resistance R 11 and R12 is connected with the reference voltage input of the second comparator 8.The reference voltage of the 3rd comparator 9 is the series connection dividing potential drop of resistance R 15, R16 and power supply VC, and the intermediate connection point of resistance R 15 and R16 is connected with the reference voltage input of the 3rd comparator 9.By preamble as can be known, when detecting electric leakage, the first comparator 7 is output as high level, after the high level of the first comparator 7 outputs is input to the second comparator 8 so, output also is high level, the effect that triggers holding unit 4 is used for triggering holding unit 5 on the one hand, is to be used for triggering the high level voltage of holding unit 5 stable on the other hand.Be connected with the input of the 3rd comparator 9 of trigger element 5 behind the second comparator 8 output high level, so just trigger holding unit 5 and be output as high level, because the output of the 3rd comparator 9 forms positive feedback by resistance R 17 and R18, so just so that the input of the 3rd comparator 9 keeps high level always, the output of holding unit 5 also keeps high level.Holding unit 5 just can the conducting of maintained switch triode like this, so that direct current relay keeps attracting state.
Further, because input ac power is high pressure, for high pressure and low pressure are separated, protection triggers holding unit 4 and follow-up low-voltage circuit thereof, and connecting the utmost point between described triggering holding unit 4 and comparison output unit 3 has the optocoupler of partition G1.
Further, described direct current relay fly-wheel diode V3 in parallel.Because direct current relay can produce back-emf when disconnecting, circuit is impacted or the components and parts damage, fly-wheel diode V3 can well not be damaged by the protective circuit components and parts.
Execution mode two:
As shown in Figure 2, the single phase poaer supply of the utility model single phase poaer supply electric-leakage detection circuit may connect a plurality of outputs, in order to detect when electric leakage, can control each output branch road is disconnected.Other parts of execution mode two are identical with execution mode one, difference is parallel with a plurality of holding units at the output that triggers holding unit 4, be connected with the relay trigger element behind each holding unit, the output of each holding unit is connected with the switch triode base stage of relay trigger element.
Although more than described embodiment of the present utility model, but those of skill in the art in the art are to be understood that, these only illustrate, and can make various changes or modifications to these execution modes, and not deviate from principle of the present utility model and essence.Scope of the present utility model only has appended claims to limit.
Claims (4)
1. isolated neutral system single phase poaer supply electric-leakage detection circuit, it is characterized in that: the two poles of the earth of described single phase poaer supply respectively are connected with a rectifier diode, be connected with sampling unit between described two rectifier diodes and the ground, the output of described sampling unit is connected with the comparison output unit, and described relatively output unit is connected with the relay trigger element;
Wherein, described sampling unit comprises the series circuit of sampling resistor and divider resistance, and described sampling resistor two ends are parallel with filter capacitor, and the tie point of described sampling resistor and divider resistance is the sampling output;
Described relatively output unit comprises the first comparator, and the input of described the first comparator is connected with the sampling output;
Described relay trigger element comprises direct current relay and switch triode, and the collector electrode of described switch triode is connected with direct current relay, and the base stage of described switch triode is connected with the first comparator output terminal.
2. according to isolated neutral system single phase poaer supply electric-leakage detection circuit claimed in claim 1, it is characterized in that: be connected with holding unit between described switch triode and the comparison output unit, be connected with the triggering holding unit between described holding unit and the comparison output unit;
Described holding unit comprises the 3rd comparator, and the output of described the 3rd comparator is by the resistance formation positive feedback that is connected with input;
Described triggering holding unit comprises the second comparator, and the input of described the second comparator is connected with the first comparator output terminal, and the output of described the second comparator is connected with the 3rd comparator input terminal.
3. according to isolated neutral system single phase poaer supply electric-leakage detection circuit claimed in claim 2, it is characterized in that: connecting the utmost point between described triggering holding unit and the comparison output unit has the partition optocoupler.
4. according to isolated neutral system single phase poaer supply electric-leakage detection circuit claimed in claim 1, it is characterized in that: described direct current relay fly-wheel diode in parallel.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201220686586 CN202957571U (en) | 2012-12-12 | 2012-12-12 | Electric leakage detection circuit for single-phase power supply of isolated neutral system |
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| Application Number | Priority Date | Filing Date | Title |
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| CN 201220686586 CN202957571U (en) | 2012-12-12 | 2012-12-12 | Electric leakage detection circuit for single-phase power supply of isolated neutral system |
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| CN202957571U true CN202957571U (en) | 2013-05-29 |
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| CN 201220686586 Expired - Fee Related CN202957571U (en) | 2012-12-12 | 2012-12-12 | Electric leakage detection circuit for single-phase power supply of isolated neutral system |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103066554A (en) * | 2012-12-12 | 2013-04-24 | 常州联力自动化科技有限公司 | Single-phase source leakage detection circuit for isolated neutral system |
| CN105529681A (en) * | 2014-09-29 | 2016-04-27 | 上海宝钢工业技术服务有限公司 | Leakage protection circuit for low-voltage ungrounded system and realization method |
| CN110441603A (en) * | 2019-08-13 | 2019-11-12 | 西安西驰电气股份有限公司 | A kind of earth leakage search/lockout sample circuit and detection method |
-
2012
- 2012-12-12 CN CN 201220686586 patent/CN202957571U/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103066554A (en) * | 2012-12-12 | 2013-04-24 | 常州联力自动化科技有限公司 | Single-phase source leakage detection circuit for isolated neutral system |
| CN103066554B (en) * | 2012-12-12 | 2015-02-25 | 常州联力自动化科技有限公司 | Single-phase source leakage detection circuit for isolated neutral system |
| CN105529681A (en) * | 2014-09-29 | 2016-04-27 | 上海宝钢工业技术服务有限公司 | Leakage protection circuit for low-voltage ungrounded system and realization method |
| CN105529681B (en) * | 2014-09-29 | 2019-03-01 | 上海宝钢工业技术服务有限公司 | The earth leakage protective implementation method of low voltage ungrounded system |
| CN110441603A (en) * | 2019-08-13 | 2019-11-12 | 西安西驰电气股份有限公司 | A kind of earth leakage search/lockout sample circuit and detection method |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| PE01 | Entry into force of the registration of the contract for pledge of patent right |
Denomination of utility model: Single-phase source leakage detection circuit for isolated neutral system Effective date of registration: 20140605 Granted publication date: 20130529 Pledgee: Jiangsu Jiangnan Rural Commercial Bank Limited by Share Ltd Pledgor: Changzhou Lianli Automation Technology Co., Ltd. Registration number: 2014990000436 |
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| PLDC | Enforcement, change and cancellation of contracts on pledge of patent right or utility model | ||
| PC01 | Cancellation of the registration of the contract for pledge of patent right |
Date of cancellation: 20150529 Granted publication date: 20130529 Pledgee: Jiangsu Jiangnan Rural Commercial Bank Limited by Share Ltd Pledgor: Changzhou Lianli Automation Technology Co., Ltd. Registration number: 2014990000436 |
|
| PLDC | Enforcement, change and cancellation of contracts on pledge of patent right or utility model | ||
| PE01 | Entry into force of the registration of the contract for pledge of patent right |
Denomination of utility model: Single-phase source leakage detection circuit for isolated neutral system Effective date of registration: 20150604 Granted publication date: 20130529 Pledgee: Jiangsu Jiangnan Rural Commercial Bank Limited by Share Ltd Pledgor: Changzhou Lianli Automation Technology Co., Ltd. Registration number: 2015990000434 |
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| PLDC | Enforcement, change and cancellation of contracts on pledge of patent right or utility model | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20130529 Termination date: 20171212 |