CN1889319A - Residual current protection circuit - Google Patents
Residual current protection circuit Download PDFInfo
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- CN1889319A CN1889319A CN 200510027421 CN200510027421A CN1889319A CN 1889319 A CN1889319 A CN 1889319A CN 200510027421 CN200510027421 CN 200510027421 CN 200510027421 A CN200510027421 A CN 200510027421A CN 1889319 A CN1889319 A CN 1889319A
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Abstract
The present invention provides a residual current protective circuit. It contains circuit breaker, zero sequence current transformer, failure detector circuit, executing relay, latch circuit, experimental circuit; when wire occurring ground fault or earthing neutral status, failure detector circuit capable of detecting out residual current and making latch circuit lock up in second two stable position, making executing relay keeping on power off condition, disconnecting load and main-supply, reaching security protection. Said test button TA can make circuit generating one analogy residual current for detecting electrical leakage protecting plug normal working, also used as electrical leakage protecting plug disjunction button.
Description
Technical field
The invention belongs to the Electrical Safety resist technology field of electronics, electric equipment, particularly a kind of residual current safety guard.
Background technology
The conventional typical supply power mode of electric equipment is to adopt AC power, and a socket by couple of conductor makes electronic and electrical equipment or load receive power supply.Electronic and electrical equipment directly links to each other with power supply by couple of conductor, and it is bigger to have constituted in the earth fault of a series of unsafe conditions, particularly phase line and the ground connection implementations risk, and when the current unbalance of the phase line and the neutral line, earth fault will take place; When neutral conductor load place ground connection, implementations will take place in the ground connection.Both of these case all has great danger, may cause serious personal injury and other property loss.
Summary of the invention
The object of the present invention is to provide a kind of residual current protection circuit, it can find earth fault or ground connection neutral fault, avoids the electronic equipment of routine or the loss that therefore load causes.
For reaching above-mentioned purpose, the present invention adopts following technical scheme,
A kind of residual current protection circuit comprises circuit-breaker, zero sequence current mutual inductor, fault-sensing circuit, rectification circuit, execution relay circuit, latch circuit, hookup, wherein,
Described zero sequence current mutual inductor comprises induction coil, and the elementary of described induction coil is connected on the power supply, and the secondary of described induction coil is connected with hookup with fault-sensing circuit respectively; Described zero sequence current mutual inductor induces earth fault or the ground connection neutral fault in the power supply, and at described secondary generation induced signal;
Described circuit-breaker comprises switch, described switch is connected on any of two phase lines of power supply, described circuit-breaker links to each other with the execution relay circuit, accept described execution relay circuit control, when described switch disconnects, load outage on this phase line, when switch closure, the load energising on this phase line;
Described rectification circuit links to each other with power supply, for row relay circuit and fault-sensing circuit provide D.C. regulated power supply;
Carry out relay circuit and comprise relay, the elementary two ends of described relay link to each other with latch circuit with described fault-sensing circuit respectively, are used to receive the triggering signal of latch circuit, and the secondary and described switch of described relay links to each other; This is carried out relay circuit and all can work under energising and off-position, and described execution relay circuit places the closed and disconnected state with described switch respectively when energising or outage;
Described latch circuit links to each other with described fault-sensing circuit, execution relay circuit; This latch circuit all can be worked under two kinds of two-stable positions, and when described latches were in the two-stable position of disconnection, the execution relay circuit changes into from off-position kept "on" position; When latches were in the two-stable position of conducting, the execution relay circuit changes into from "on" position kept off-position.Described latch circuit can adopt controllable silicon or rectifier diode circuit, preferred rectifier diode circuit among the present invention, and the positive pole of described rectifier diode circuit links to each other minus earth with the execution relay circuit.
Described fault-sensing circuit comprises control circuit, described control circuit carries out amplification ratio to the secondary induced signal of zero sequence current mutual inductor, in case find earth fault or ground connection neutral fault, the output control signal is given latch circuit, latch circuit is locked under the two-stable position of conducting, make described relay maintain off-position.
As a kind of improvement of the present invention, also comprise hookup, described hookup comprises the test switch and the current-limiting resistance of series connection, described hookup links to each other with power supply, when described test switch is closed, produce an analogue ground fault current, the switch of described circuit-breaker is disconnected, thereby make the load outage.
As another improvement of the present invention, also comprise reset switch, described reset switch links to each other with latch circuit with the execution relay circuit, and described reset switch is used to recover the two-stable position that latch circuit disconnects, thus the normal power supply state of restore circuit.
The design has adopted univoltage structure and zero current blocking-up one-way SCR reset circuit, it is simple in structure and function is superior, plug can auto-closing and the function of disconnection when realizing power source change, the contact switching of this plug has adopted traditional electromagnetic type relay tactic pattern, contact is connected circuit, contact open circuit during release during sticking.
This residual current protection circuit not only can prevent the electric shock accidents that causes because of apparatus failure; and can also prevent because of the electric shock accidents that power failure caused beyond the electrical equipment; it can detect implementations in earth fault on the lead and the ground connection residual current protection circuit that provides of invention; contain can deenergization and load between the relay of at least one lead; relay can be switched on and be maintained on the "on" position with minimum power consumption and minimum caloric value; its number of elements is minimum, and assembling is simple.
Further specify the present invention below in conjunction with drawings and Examples.
Description of drawings
Fig. 1 is an embodiment of the invention residual current protection circuit schematic diagram;
Fig. 2 is embodiment of the invention residual current protection circuit figure.
Embodiment
As shown in Figure 1 and Figure 2, a kind of residual current protection circuit comprises: circuit-breaker, zero sequence current mutual inductor, fault-sensing circuit, rectification circuit, execution relay circuit, latch circuit, reset switch RA1.Wherein,
Described zero sequence current mutual inductor comprises induction coil LM1 and LM2, and the elementary of described two induction coils is connected on the power supply, and the secondary of described induction coil is connected with hookup with fault-sensing circuit respectively; Described zero sequence current mutual inductor induces earth fault or the ground connection neutral fault in the power supply, and at described secondary generation induced signal;
Described circuit-breaker comprises switch, described switch is connected on any of two phase lines of power supply, described circuit-breaker links to each other with the execution relay circuit, accept described execution relay circuit control, when described switch disconnects, load outage on this phase line, when switch closure, the load energising on this phase line;
Described rectification circuit links to each other with power supply, provides D.C. regulated power supply for carrying out relay circuit and fault-sensing circuit; Rectification circuit adopts the bridge rectifier that is made of diode V1, V2, V3, V4, and piezo-resistance RN1 is connected on two phase lines of power supply, has reduced circuit noise since resistance R 1 and capacitor C 5 usefulness.
Relay circuit comprises relay FL1, transistor V7, current-limiting resistance R2, R4, the filter circuit that is made of divider resistance R7 and noise reduction capacitor C 7, the rectifier diode V5 that high back voltage disturbs when preventing the actuating of relay.The elementary two ends of described relay link to each other with latch circuit with described fault-sensing circuit respectively, are used to receive the triggering signal of latch circuit, and the secondary and described switch of described relay links to each other; Divider resistance R4 links to each other with the base stage of reset switch RA and triode V7.This relay circuit can optionally move or keep above-mentioned switch on disconnection or make position, described relay all can be worked under energising and off-position, the relay switch is set to make position when energising, the relay switch is set to open position during outage, the circuit detection circuit can optionally be supplied primary voltage by above-mentioned switch to relay, at this moment switch is in open position, and relay changes "on" position into from outage like this.Power circuit supply secondary voltage is to relay, and after relay was by the primary voltage energising, the secondary voltage that is lower than primary voltage was enough to make relay to keep "on" position, but is not enough to make it to become "on" position from outage.
Described latch circuit is made up of rectifier diode V6 and current-limiting resistance R3, filter capacitor C6, and described latch circuit links to each other with described fault-sensing circuit, execution relay circuit; The positive pole of rectifier diode V6 links to each other with the execution relay circuit by resistance R 3, minus earth, filter capacitor C6 one end links to each other with the output control signal pin of the control chip of fault-sensing circuit, other end ground connection. described latches all can be worked under conducting and disconnection two-stable position, when being in the two-stable position of disconnection, described latch circuit allows relay change into from off-position and keeps "on" position; When latches were in the two-stable position of conducting, described latch circuit allowed relay change into from "on" position and keeps off-position;
Described fault-sensing circuit comprises control circuit, this control circuit comprises filter capacitor C2, C4, coupling capacitance C3, feedback resistance R5 capacitor C 1, current-limiting resistance R6 and control chip, pin VCC, the GND of this control chip links to each other with the positive and negative electrode in rectification circuit output DC source respectively, enter the input signal pin of control chip respectively from the coupled signal of induction coil LM1, LM2 output behind filter rectification, the output signal pin of control chip links to each other with latch circuit.Described control circuit carries out amplification ratio to the secondary induced signal of zero sequence current mutual inductor, in case find earth fault or ground connection neutral fault, the output control signal is given latch circuit, and latch circuit is locked under the two-stable position of conducting, makes described relay maintain off-position.The power supply of open failure circuit.
Described hookup comprises test switch TA1, current-limiting resistance RT1, R8 and rectifier diode V8, the V9 of series connection.Described hookup links to each other with power supply, when described test switch is closed, produces an analogue ground fault current, and the switch of described circuit-breaker is disconnected, thus the power supply of open failure circuit.
Described reset switch RA1 links to each other with latch circuit with the execution relay circuit, and described reset switch is used to recover the two-stable position that latch circuit disconnects, thus the normal power supply of restore circuit.
Under normal operation, the current phasor in the circuit and be zero, zero sequence current mutual inductor does not have signal output, rectifier diode V6 blocking-up, rectifier diode V7 conducting, relay FL1 adhesive, iron core promotes contact closure, and power supply indicator is bright, the indication circuit normal power-up.
When the earth fault current in the protected circuit surpasses predetermined value; the detected signal of zero sequence current mutual inductor triggers rectifier diode V6 conducting after electronic amplification circuit amplifies; make rectifier diode V7 block; relay FL1 dead electricity; iron core drives contact and disconnects under spring action, thereby plays a protective role.After earth fault is got rid of, press reset button RA1, make rectifier diode V6 block rectifier diode V7 conducting, circuit recovers the normal power supply state.Test button TA1 both can make and produce a simulation residual current in the circuit, to detect the leakage protecting plug operate as normal, also can be used as the disjunction button of leakage protecting plug.
Claims (3)
1, a kind of residual current protection circuit, it is characterized in that comprising: circuit-breaker, zero sequence current mutual inductor, fault-sensing circuit, execution relay, latch circuit, hookup, wherein, described zero sequence current mutual inductor comprises two induction coils, one terminates on the power supply, and the other end is connected with fault-sensing circuit, latch circuit respectively; Described zero sequence current mutual inductor can induce earth fault or the ground connection neutral fault in the power supply, and at secondary generation induced signal;
Circuit-breaker comprises switch, and it is connected on any of two phase lines of power supply, controlled by latch circuit, when switch disconnects, and the load outage on this phase line, when switch closure, the load energising on this phase line;
Carry out relay and comprise relay, described relay is elementary to link to each other with fault-sensing circuit and by its power supply, and the while links to each other with latch circuit and receives the triggering signal of latch circuit, and described relay is secondary to link to each other with switch; This execution relay places closure state with described switch when energising, then places off-state during outage;
Described latch circuit links to each other with fault-sensing circuit, execution relay; When latches were in the disconnection two-stable position, the execution relay changes into from off-position kept "on" position; When latches were in the conducting two-stable position, the execution relay changes into from "on" position kept off-position;
Fault-sensing circuit comprises rectification circuit and control circuit, rectification circuit provides D.C. regulated power supply for this circuit, control circuit can amplify comparison process to the secondary induced signal of zero sequence current mutual inductor, in case the discovery fault, this control circuit output control signal is locked latch circuit under the conducting two-stable position;
Hookup comprises test switch TA1, and described hookup directly is connected on two phase lines of power supply, is used to produce an analogue ground fault current.
2, residual current protection circuit according to claim 1 is characterized in that: also comprise a reset switch RA1, this switch links to each other with execution relay, latch circuit, but is used for the normal power supply state of restore circuit.
3, residual current protection circuit according to claim 1 is characterized in that: described latch circuit comprises rectifier diode V6, and this diode cathode links to each other minus earth with the execution relay.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200510027421 CN1889319A (en) | 2005-06-30 | 2005-06-30 | Residual current protection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200510027421 CN1889319A (en) | 2005-06-30 | 2005-06-30 | Residual current protection circuit |
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|---|---|
| CN1889319A true CN1889319A (en) | 2007-01-03 |
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| CN 200510027421 Pending CN1889319A (en) | 2005-06-30 | 2005-06-30 | Residual current protection circuit |
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Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2008083539A1 (en) * | 2007-01-12 | 2008-07-17 | Lian Electric (Heshan) Technology Development Co. Ltd. | A monitoring type operative protective relay for residual current |
| CN101145683B (en) * | 2007-10-31 | 2010-09-29 | 李志学 | Control device for residual current of low-voltage power grid |
| CN101316037B (en) * | 2007-05-29 | 2010-10-13 | 浙江正泰电器股份有限公司 | Aftercurrent action protector with self-diagnostic function |
| CN101557094B (en) * | 2009-01-20 | 2011-04-20 | 南京鼎牌电器有限公司 | Disconnection auto-action or alarm circuit of external residual current transformer |
| CN102931634A (en) * | 2012-11-23 | 2013-02-13 | 黄柄皓 | Multifunctional circuit breaker |
| CN101902025B (en) * | 2009-05-31 | 2013-03-20 | 西门子公司 | Method for protecting safety of circuit and device thereof |
| CN103345872A (en) * | 2013-07-16 | 2013-10-09 | 南京丹迪克科技开发有限公司 | Residual current action protecting system practical training device |
| CN105790212A (en) * | 2016-04-27 | 2016-07-20 | 国网安徽省电力公司六安市叶集供电公司 | Meter-box intelligent residual-current circuit breaker |
| CN107526010A (en) * | 2017-09-30 | 2017-12-29 | 南京国电南自电网自动化有限公司 | A kind of distributed small current earthing wire-selecting method based on double CT samplings |
-
2005
- 2005-06-30 CN CN 200510027421 patent/CN1889319A/en active Pending
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2008083539A1 (en) * | 2007-01-12 | 2008-07-17 | Lian Electric (Heshan) Technology Development Co. Ltd. | A monitoring type operative protective relay for residual current |
| CN101316037B (en) * | 2007-05-29 | 2010-10-13 | 浙江正泰电器股份有限公司 | Aftercurrent action protector with self-diagnostic function |
| CN101145683B (en) * | 2007-10-31 | 2010-09-29 | 李志学 | Control device for residual current of low-voltage power grid |
| CN101557094B (en) * | 2009-01-20 | 2011-04-20 | 南京鼎牌电器有限公司 | Disconnection auto-action or alarm circuit of external residual current transformer |
| CN101902025B (en) * | 2009-05-31 | 2013-03-20 | 西门子公司 | Method for protecting safety of circuit and device thereof |
| CN102931634A (en) * | 2012-11-23 | 2013-02-13 | 黄柄皓 | Multifunctional circuit breaker |
| CN103345872A (en) * | 2013-07-16 | 2013-10-09 | 南京丹迪克科技开发有限公司 | Residual current action protecting system practical training device |
| CN105790212A (en) * | 2016-04-27 | 2016-07-20 | 国网安徽省电力公司六安市叶集供电公司 | Meter-box intelligent residual-current circuit breaker |
| CN107526010A (en) * | 2017-09-30 | 2017-12-29 | 南京国电南自电网自动化有限公司 | A kind of distributed small current earthing wire-selecting method based on double CT samplings |
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