CN2894019Y

CN2894019Y - Neutral conductor protector

Info

Publication number: CN2894019Y
Application number: CN 200520122673
Authority: CN
Inventors: 张颖
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-09-21
Filing date: 2005-09-21
Publication date: 2007-04-25
Anticipated expiration: 2015-09-21

Abstract

A new neutral wire protector is characterized in that a shunt resistance is connected in parallel with an output port of a rectification circuit. A series circuit comprises an electronic switch, an obstructive anti-interference circuit, an auxiliary electronic switch and a tripping electromagnet, both ends of the series circuit are connected with the live wire in the major loop and the protection grounding terminal respectively, the filter circuit is connected with the voltage offset circuit in series, the control terminal is connected with one end of the series circuit, the cathode in the output port of the rectification circuit is connected with the other end of the series circuit, the cordwood system-typed combination of three groups of the network circuit in the single-phrase sub-protection unit is used to produce the master protection circuit for the three-phase distribution system, the simulation test circuit is connected between the zero line of the major loop and the protection circuit in series. The utility model is characterized in that the circuit structure is simple and without the need of an auxiliary power, static power consumption is low, an effective protection is available for zero drift failure of the neural wire in TT, TN-S and TN-C-S and advanced protective action is also available for failure of the zero line .

Description

Novel neutral line protector

Affiliated technical field

The utility model relates to a kind of to the protective device single-phase or safe operation of the three-phase power distribution system AC power neutral line; especially disconnected zero is that branch connecting to neutral place opens circuit and drift is a bus connecting to neutral place open circuit fault, the safety guard that can both react rapidly simultaneously.

Background technology

No matter be single-phase or three-phase power distribution system in the neutral line occur resolving zero or during the drift fault, all can cause serious harm to user's personal safety and power consumption equipment.Currently used safeguard measure is the neutral conductor interrupted protective equipment of connecting in major loop, and when in the system during neutral line generation deadly condition, protector allows main contacts thread off automatically.One be to protect function inadequately comprehensively and complete but existing such installs all ubiquity, the 2nd, and the required material cost expense of the design more complicated of protective circuit is also than higher.For example, Chinese utility model discloses a kind of application number and has been, 00263280.2 disconnected zero line protector has only provided the drift resist technology solution of three-phase power distribution system, lacks versatility.

Summary of the invention

There is complex circuit designs in the prior art solution, manufacturing cost is high and can not satisfy single-phase simultaneously and three-phase power distribution system in order to overcome; shortcoming to disconnected zero-sum drift error protection demand; the utility model provides a kind of design of novel universal neutral line safety guard; can not only satisfy simultaneously safeguard protection requirement single-phase and the disconnected zero-sum drift fault of three-phase power distribution system; and; the novel quiescent dissipation of the simplicity of design of protective circuit is low, and manufacturing cost is inexpensive.

The technical scheme in the invention for solving the technical problem is: outside the forceful electric power master returns; in the design of light current protective circuit; design a kind of total protective circuit (B represents with symbols Z) and serve as the protection task of the three-phase power distribution system neutral line disconnected zero and drift fault; use three of total protective circuit/part (B/3 represents with symbols Z) as sub-protective circuit again, serve as the protection task of the single phase distribution system neutral line disconnected zero and drift fault.Two the shared sub-network contact B of sub-protective circuit ZB/3 and PE ' are divided into two groups by contact of the same name and do and be connected in parallel, and produce overall network contact B ' and the PE of total protective circuit ZB ", the contact K among overall network contact B ' and the simulated experiment circuit ₁Link to each other the contact K among the simulated experiment circuit ₂Link to each other with the zero line N ' or the N of distribution system AC power; overall network contact PE " links to each other with the end of release electromagnet DT through auxiliary electron switch S CR '; the other end of release electromagnet DT links to each other with protective grounding (PE represents with symbol); and form last remaining three the sub-network node A of the sub-protective circuit ZB/3 part of three groups of total protective circuit ZB, does not do intraconnection separately as three special-purpose overall network contact A of total protective circuit ZB ₁, A ₂, A ₃With three live wire L in the three-phase power distribution system _{1 '}, L _{2 '}, L _{3 '}Corresponding linking to each other.In the lattice network of sub-protective circuit ZB/3 part, piezo-resistance is with after rectification circuit input end is in parallel, a terminal screw network node B, another termination sub-network contact A, shunt resistance R _FBe connected in parallel on the output of rectification circuit filter resistance R with the interface C ' O ' of standby function upgrading expansion design circuit _LThe gate pole g of one termination electronic switch SCR, on the negative pole end of the other end among voltage offset circuits DB3 receives rectification circuit output end, filter capacitor C _LBe connected in parallel on the two ends of the negative electrode k of electronic switch SCR and gate pole g, the negative electrode k of electronic switch SCR links to each other with sub-network contact PE ' through the obstructive type anti-jamming circuit, anode a and the connected mode between the rectification circuit of electronic switch SCR have two kinds can choose wantonly, a kind of is on that end that anode a with SCR receives among the rectification circuit input end with sub-network contact A links to each other, and another kind is that the anode a of SCR is linked to each other with positive terminal among the rectification circuit output end.

The beneficial effects of the utility model are: not only overcome existing similar protector fully; can not be to shortcoming single-phase and that the disconnected zero-sum drift fault of the three-phase power distribution system neutral line is protected simultaneously; and; can also be to the disconnected zero failure of the neutral line; have expection and promptly make the Motor ability of protective reaction in advance, the protective circuit simplicity of design need not be provided with accessory power supply, quiescent dissipation is low, antijamming capability is strong, working stability is reliable.In addition, aspect the analogue test of defencive function, have modern design, flexible operation, the comprehensive advantage of test.

Description of drawings:

The utility model is described in further detail below in conjunction with drawings and Examples.

Fig. 1 is a frame principle figure of the present utility model.

Fig. 2 is the ZB/3 promptly 13 or frame principle figure of 14 or 15 sub-protective circuit network portions.

Fig. 3 is the ZB/3 promptly 13 or circuit theory diagrams of 14 or 15 sub-protective circuit network portions.

Fig. 4 is the circuit theory diagrams of the utility model specific embodiment.

Fig. 5 is the circuit theory diagrams of another execution mode of the utility model.

Live wire input L among the figure in the 1. single phase distribution systems or the live wire input L in the three-phase power distribution system ₁, 2. live wire output L ' in the single phase distribution system or the live wire output L in the three-phase power distribution system _{1 '}, 3. zero line input N in the single phase distribution system or the live wire input L in the three-phase power distribution system ₂, 4. zero line output N ' in the single phase distribution system or the live wire output L in the three-phase power distribution system _{2 '}, the 5. live wire input L in the three-phase power distribution system ₃, the 6. live wire output L in the three-phase power distribution system _{3 '}7. the zero line input N in the three-phase power distribution system; 8. the zero line output N ' in the three-phase power distribution system, 9. major loop, 10. simulation experiment circuit; 11. t.a; 12. total protective circuit ZB (=ZB/3+ZB/3+ZB/3), 13. sub-protective circuit ZB/3,14. sub-protective circuit ZB/3; 15. sub-protective circuit ZB/3,16. piezo-resistance R _V, 17. shunt resistance R _F, 18. rectification circuits, 19. voltage offset circuits DB3,20. filter resistance R _L, 21. electronic switch SCR, 22. filter capacitor C _L, 23. obstructive type anti-jamming circuits, 24. auxiliary electron switch S CR ', 25. release electromagnet DT, 26. protective grounding PE.

Embodiment

In Fig. 1; total protective circuit (12); be by the cordwood system type combination of the identical three groups of sub-protective circuits of ZB/3 (13) of circuit structure and ZB/3 (14) and ZB/3 (15) part and form; with being connected in parallel of sub-protective circuit ZB/3 (13) and ZB/3 (14) and ZB/3 (15) three shared sub-network contact PE ' partly, produce the overall network contact PE of total protective circuit ZB (12) ".With being connected in parallel of sub-protective circuit ZB/3 (13) and ZB/3 (14) and ZB/3 (15) three shared sub-network contact B partly, produce the overall network contact B ' of the ZB (12) of total protective circuit.Also remaining at last three the sub-network node A altogether of sub-protective circuit ZB/3 (13) and ZB/3 (14) and ZB/3 (15) part then do not carry out interconnected, specialize in total protective circuit ZB (12) and are used for producing three overall network contact A for the three-phase power distribution system special use ₁, A ₂, A ₃With three-phase firewire L _{1 '}(2), L _{2 '}(4), L _{3 '}(6) corresponding linking to each other.Overall network contact B ' links to each other with the zero line N ' (8) or the N (7) of three-phase power distribution system through simulated experiment circuit (10).Overall network contact PE " links to each other with protective grounding PE (26) with the series circuit of release electromagnet DT (25) through auxiliary electron switch S CR ' (24).

In Fig. 2, piezo-resistance R _V(16) and the input of rectification circuit (18) be parallel to jointly on sub-network contact B and the A two ends.Shunt resistance R _F(17) be connected in parallel on the output of rectification circuit (18).The gate pole g of electronic switch SCR (21) is through filter resistance R _L(20) link to each other with negative pole end among rectification circuit (18) output with the series circuit of voltage offset circuits DB3 (19).Filter capacitor C _L(22) be connected in parallel on the negative electrode k and gate pole g two ends of electronic switch SCR (21).The negative electrode k of electronic switch SCR (21) links to each other with sub-network contact PE ' through blocking anti-jamming circuit (23).The anode a of electronic switch SCR (21), can with the input of rectification circuit (18) among, that end that links to each other with sub-network contact A links to each other, and also can link to each other with the positive terminal among rectification circuit (18) output.

In Fig. 3, diode D ₁, D ₂And D ₃, D ₄Negative electrode, anode do respectively to do again to be connected in parallel after the order series connection and produce rectification circuit (18), the input of rectification circuit (18) is respectively from D ₂Negative electrode and D ₃Anode on introduce, B links to each other with A with the sub-network contact, piezo-resistance R _v(16) be connected in parallel on the input of rectification circuit (18) piezo-resistance R _v(16) can not be provided with yet.The cathode output end of rectification circuit (18) is from diode D ₁, D ₃Draw on the negative electrode parallel with one another and be connected to contact C, the cathode output end of rectification circuit (18) is from diode D ₂, D ₄Draw on the anode parallel with one another and be connected to contact 0.Shunt resistance R _F(17) be connected in parallel on 2 of contact C, the O.Filter resistance R _L(20) signal input part, after voltage offset circuits DB3 (19) connects, receive among rectification circuit (18) output negative pole end on, filter resistance R _L(20) signal output part is received on the gate pole g end of electronic switch SCR (21).Voltage offset circuits DB3 (19) can adopt diac to serve as, and also can adopt voltage stabilizing didoe to serve as, and also can adopt piezo-resistance to serve as, and also can not be provided with.Filter capacitor C _L(22) two ends are connected in parallel on the negative electrode k and gate pole g two ends of electronic switch SCR (21).Obstructive type anti-jamming circuit (23) is by diode D _KAnd resistance R _KParallel circuits serve as D _KAnode connect the negative electrode k end of electronic switch SCR (21), D _KNegative electrode meet sub-network contact PE ', obstructive type anti-jamming circuit (23) can not be provided with yet.The anode a of electronic switch SCR (21) can be connected on diode D ₃Anode on, also can be connected on D ₃Negative electrode on.In Fig. 3,, be that spare interface C ', O ' can not be provided with yet for the spare interface of the usefulness of defencive function upgrading expansion design circuit connection with 2 C ' that link to each other of circuit junction C, O, O ' 2 points.

In Fig. 4, total protective circuit ZB (12) is that cordwood system type by the identical three groups of sub-protective circuit ZB/3 (13) of circuit structure and ZB/3 (14) and ZB/3 (15) part makes up and generation.Three shared sub-network contact PE ' of sub-protective circuit ZB/3 (13) and ZB/3 (14) and ZB/3 (15) part are connected in parallel, and have produced the overall network contact PE of total protective circuit ZB (12) ".Three shared sub-network contact B of sub-protective circuit ZB/3 (13) and ZB/3 (14) and ZB/3 (15) part are connected in parallel, and have produced the overall network contact B ' of total protective circuit ZB (12).Last also remaining three the sub-network node A altogether of sub-protective circuit ZB/3 (13) and ZB/3 (14) and ZB/3 (15) part then do not do interconnected, specialize in total protective circuit ZB (12) and are used for producing three overall network contact A for the three-phase power distribution system special use ₁, A ₂, A ₃With three-phase firewire L _{1 '}(2), L _{2 '}(4), L _{3 '}(6) corresponding linking to each other.Auxiliary electron switch S CR ' (24), by controllable silicon SCR ' negative electrode and diode D _FAnode; Controllable silicon SCR ' anode and diode D _FNegative electrode do to be connected in parallel and serve as the gate pole of SCR ' and capacitor C ₂And resistance R ₂, R ₃An end do and be connected in parallel resistance R ₂The other end and capacitor C ₁With resistance R ₁An end do and be connected in parallel resistance R ₁The other end and diode D ₅Negative electrode links to each other, capacitor C ₁, C ₂And resistance R ₃The other end do jointly and link to each other diode D again with the negative electrode of SCR ' after being connected in parallel ₅Anode can be from live wire L _{1 '}(2), L _{2 '}(4), L _{3 '}(6) choose one of them for example L among wantonly _{1 '}(2) be attached thereto; the anode of SCR ' " links to each other; the negative electrode of SCR ' links to each other with the end of release electromagnet DT (25); the other end of release electromagnet DT (25) links to each other with protective grounding PE (26), and auxiliary electron switch S CR ' (24) can not be provided with yet with the overall network contact PE of total protective circuit ZB (12).Test resistance R in the simulation experiment circuit (10) _SAn end and the contact K on the socket CZ ₁Link to each other the contact K on the other end and the socket CZ ₃Link to each other contact K ₁, K ₂Be the normally closed contact on the socket CZ, K ₁B ' links to each other with the overall network contact, K ₂Link to each other with zero line N ' (8) or N (7).In t.a (11), coupled together by the test lead between plug CT and the test probe TT, between t.a (11) and the simulation experiment circuit (10), adopt axis hole formula machinery to be slidingly connected or the wiring pillar is fixedly connected or several means such as switch/relay conversion can be chosen one of them wantonly, simulation experiment circuit (10) and t.a (11) can not be provided with yet.K in the major loop (9) _L1, K _L2, K _L3, (K _N) be respectively the main disjunction contact of three-phase firewire and zero line, Y _TL1, Y _TL2, Y _TL3, (Y _TN) be respectively three-phase firewire and zero line thermal release device, C _TL1, C _TL2, C _TL3, (C _TN) be respectively the magnetic trip gear of three-phase firewire and zero line, the K that the with dashed lines square frame draws among the figure _N, Y _TN, C _TN, expression can not be provided with.This figure is that novel neutral line protector is applied in three-phase and four-line TT, TN-S, TN-C-S ground connection pattern distribution system, the circuit theory diagrams of three utmost points, four lines or four utmost point major loops (9).Now introduce the operation principle of the utility model (Fig. 4): the main disjunction contact K in major loop (9) in conjunction with Fig. 2 and Fig. 3 _L1, K _L2, K _L3, (K _N) behind the combined floodgate, at three-phase firewire output L _{1 '}(2), L _{2 '}(4), L _{3 '}(6) go up the phase voltage that exists, V with PE (26) ₂₂₆, V ₄₂₆, V ₆₂₆Under the effect, obstructive type anti-jamming circuit (23) can make in the interior ZB/3 (13) of total protective circuit ZB (12) body and ZB/3 (14) and the sub-protective circuit of ZB/3 (15) and produce three I _{3 '}Electric current come, this electric current is at sub-protective circuit ZB/3 (13) and ZB/3 (14) and ZB/3 (15) three filter capacitor C in partly _LOn; all set up simultaneously the noise jamming blocking voltage (being generally about 12 volts) of a negative polarity, make to be distributed in sub-protective circuit ZB/3 (13) and ZB/3 (14) and ZB/3 (15) three electronic switch SCR in partly in total protective circuit ZB (12) body and can not triggered and the phenomenon that misleads occurs by noise jamming.When the drift fault has appearred in the neutral line of three-phase power distribution system, drift voltage V ₈₂₆Can raise along with the increase of the uneven degree of threephase load, work as V ₈₂₆When being elevated to the activation threshold value greater than voltage offset circuits DB3 (19), V ₈₂₆Just can in the ZB/3 (13) and ZB/3 (14) and the sub-protective circuit of ZB/3 (15) in total protective circuit ZB (12) body, produce three drifts and detect electric current I _{2 '}, I _{2 '}At first to absorb each filter capacitor C in sub-protective circuit ZB/3 (13) and ZB/3 (14) and ZB/3 (15) part _L(22) on, use electric current I under normal conditions _{3 '}The negative electrical charge of being set up is only at V ₈₂₆When being elevated to greater than regulation numerical value (for example 50 volts) with the increase of the uneven degree of threephase load, Zong in protective circuit ZB (12) body mobile three I _{2 '}In the electric current, can have wherein an energy at least at filter capacitor C _L(22) set up the controllable silicon gate trigger voltage of 0.7 volt of forward on; make in the middle of three controllable silicon SCR (21) that are distributed in the interior three groups of ZB/3 (13) of total protective circuit ZB (12) body and ZB/3 (14) and the sub-protective circuit of ZB/3 (15); at least have the conducting that is triggered wherein, produce drive current I ₄, I ₄Flow to PE by PE ' and " become I through auxiliary electron switch S CR ' (24) again _{4 '}After, make release electromagnet DT (25) action, with main disjunction contact K _L1, K _L2, K _L3, (K _N) tripping operation of threading off together.Introduce novel neutral line protector (hereinafter referred protector) below; the operation principle that the disconnected zero failure of the neutral line is protected: when the downstream of protector three-phase major loop distribution output; when online the and on-load switches on all the other two-phases of the power load that a certain phase occurred having only are under the off-state of access failure; if open circuit fault has appearred in the zero line input N (7) of distribution system just at this moment, if this moment power load online be L ₁Phase is so in the body of total protective circuit ZB (12), with L ₁In sub-protective circuit ZB/3 (13) part that is connected mutually, because of V ₂₂₆=V ₈₂₆=220 volts, force I ₃=0, so will produce disconnected zero trigger current I ₂And make I ₂=I ₁The phase place of the effect voltage on the gate pole that has only the SCR (21) in sub-protective circuit ZB/3 (13) part again therefore time the and the anode is identical; so also have only the SCR (21) among the sub-protective circuit ZB/3 (13) to be triggered and conducting, produce drive current I from the sub-network contact PE ' of ZB/3 (13) by the disconnected zero failure that is taken place this moment ₄, I ₄Flow to PE " after become I _{4 '}, make release electromagnet DT (25) action with main disjunction contact K _L1, K _L2, K _L3, (K _N), the tripping operation of threading off.Introduce the utility model below to the drift fault on the neutral bus; can expect that (shifting to an earlier date) promptly make the operation principle of protective reaction action: the disconnection fault on the central sexupara line; occur in protector three-phase alternating voltage lead-out terminal all under the state of no-load running (being the equal access failure of mains switch on the power load of protector downstream) time; for three-phase alternating-current supply; unique this moment just only has been left the equivalent three-phase star internal impedance of total protective circuit ZB (12) at linear load, and this impedance is very high and three shunt resistance R that equate again by the resistance in three groups of sub-protective circuit ZB/3 (13) and ZB/3 (14) and ZB/3 (15) partial circuit _F(17) determine, so make the distribution system of this moment just be in a little power consumption three-phase star (R _Y) under the poised state of shape load, V ₈₂₆=0, drifting fault voltage signal no-output protector can't move.Obviously, protector does not this moment reflect the truth that disconnection fault has taken place at the neutral bus place.And expection protective reaction function of the present utility model but can allow protector also can make correct protective reaction action at the moment in time and come, and the concrete grammar of realization expection protective reaction holding function has two kinds and can select arbitrarily.First method is: select three shunt resistance R in the sub-protective circuit part of ZB/3 (13) and ZB/3 (14) and ZB/3 (15) _F(17) wherein one resistance value deliberately and other two unequal.Second method is: do not change three shunt resistance R that are distributed in sub-protective circuit ZB/3 (13) and ZB/3 (14) and ZB/3 (15) part _F(17) relation that all equates of original resistance, but, a live wire lead-out terminal L at the protector three-phase alternating-current supply _{1 '}(2), L _{2 '}(4), L _{3 '}(6) choose one of them for example L among wantonly _{1 '}(2), and between zero line lead-out terminal N ' (8) or the zero line input terminal N (7), additional resistance (R in parallel _{S '}), allow the three-phase alternating current distribution system, the drift voltage V that disconnection fault occurs at the moment and produced because of neutral bus _{826 '}(=V _{B ' PE}), also have enough output, force protector can make correct response, with the K in the major loop (9) _L1, K _L2, K _L3, (K _N) tripping operation of threading off.Introduce the operation principle of the utility model analogue test below: the analogue test work of protector, finish jointly by simulation experiment circuit (10) and t.a (11).Purpose is under the intact situation of the neutral line, and normally whether the working condition of checking each part of protector under the running status at any time.Before the test, earlier the plug CT on the t.a (11) is inserted in the hole of simulation experiment circuit (10) socket CZ, so, will be at normally closed contact K ₁With K ₂To test probe TT and contact K when separating ₃Couple together.Because contact K ₁With K ₂Separation, the path of distribution system zero line output N ' (8) and overall network contact B ' is cut off, the result, make protector compulsory be in one the sort of as previously described, equivalent R _YUnder the poised state of the little power consumption of shape load three-phase.Because in total protective circuit ZB (12) body, be distributed in three shunt resistance R in three groups of sub-protective circuit ZB/3 (13) and ZB/3 (14) and ZB/3 (15) partial circuit _F(17) resistance all equates, so, the drift voltage V between overall network contact B ' and the protective earthing terminal PE (26) _{B ' PE}=0, protector is failure to actuate.But take probe TT and three-phase firewire lead-out terminal L as hand _{1 '}(2), L _{2 '}(4), L _{3 '}(6) any phase firewire among, for example L _{1 '}When (2) contacting, L ₁Phase voltage 220V will be by probe TT-CT-CZ-K ₃-R _s-K ₁, appear on the overall network contact B ', make V _{B ' PE}Produce enough output voltages immediately and move immediately, with the K in the major loop (9) by protector _L1, K _L2, K _L3, (K _N) tripping operation of threading off.In order to verify in total protective circuit ZB (12) body, three groups of sons are protected whole working conditions of despreading circuit ZB/3 (13) and ZB/3 (14) and ZB/3 (15) part, and each test should be with probe TT and three-phase firewire output L _{1 '}(2), L _{2 '}(4), L _{3 '}(6) each contact once after the off-test, should be extracted CT from CZ, allows normally closed contact K among the socket CZ ₁With K ₂Get back to original normally closed closing under the state.

In Fig. 5, one of release electromagnet DT (25) terminates on the live wire L ' (2) of single phase distribution system, and the other end is connected on the sub-network contact A of sub-protective circuit ZB/3 (13).Simulation experiment circuit (10) is served as by the switching circuit part S of normally closed contact formula; one terminates on the zero line output N ' (4); the other end is connected on the sub-network contact B of sub-protective circuit ZB/3 (13); S can be a hand push button; also can be one or a pairs of posts; also can be the normally closed contact on the relay, also simulation experiment circuit (10) can be set.The sub-network contact PE ' of sub-protective circuit ZB/3 (13) links to each other with protective grounding PE (26).L H among the figure is a zero sequence current mutual inductor; only on spare interface circuit C ' O '; in the extended protection function design object of external function upgrading expansion design circuit; just need to be provided with the shunt resistance R among sub-protective circuit ZB/3 this moment (13) when containing overvoltage, under-voltage, outage time-delay and creepage protection function project _F(17) just can be used in the static equivalent d.c. resistance that exists on C ' O ' interface and replace, electromagnet DT (25) also can be connected among the series circuit of the cathode output end of the rectification circuit (18) among the sub-protective circuit ZB/3 (13) and positive contact C.When spare interface C ' O ' unsettled when idle; release electromagnet DT (25) can also be connected between the anode a of the sub-network contact A of sub-protective circuit ZB/3 (13) and electronic switch SCR (21); or between the anode a of positive terminal among rectification circuit (18) output and electronic switch SCR (21); or between the negative electrode k of electronic switch SCR (21) and the obstructive type anti-jamming circuit (23), or between obstructive type anti-jamming circuit (23) and the protective grounding PE (26).K in the major loop (9) _L, (K _N), be respectively the main disjunction contact of single-phase live wire and zero line, Y _TL, (Y _TN) be respectively the thermal release device of single-phase live wire and zero line, C _TL, (C _TN) be respectively the magnetic trip gear on single-phase live wire and the zero line, wherein the square frame that draws of with dashed lines is partly represented and can be provided with.This figure is the single phase distribution system that novel neutral line protector is applied in three-phase and four-line TT, TN-S, TN-C-S ground connection pattern, the circuit theory diagrams in two utmost points or the one pole two wires major loop (9).When the drift fault has taken place in the neutral line of protector upstream three-phase and four-line AC power, drift voltage V ₄₂₆Will raise with the increase of the load unbalanced degree of protector upstream three-phase distribution, work as V ₄₂₆During greater than regulation numerical value (for example 50V), drift detects electric current I _{2 '}Just electronic switch SCR (21) conducting that triggers among the ZB/3 (13) produces drive current I ₄, make release electromagnet DT (25) action, with the K in the major loop (9) _L, (K _N) tripping operation of threading off.When the zero line input terminal N (3) of protector single phase alternating current power supply has located to take place mains switch on open circuit fault and the power load and has been on the on-position, phase voltage V ₂₂₆=V ₄₂₆=220V forces I ₃=0 produces disconnected zero trigger current I ₂, I ₂Electronic switch SCR (21) conducting of going again to trigger among the ZB/3 (13) produces drive current I ₄, make and take off electromagnet DT (25) action the K in the major loop (9) _L, (K _N) tripping operation of threading off.

Claims

1. novel neutral line protector; be connected on the main disjunction contact in the major loop; be connected on the electronic switch SCR in the release electromagnet DT circuit; it is characterized in that: release electromagnet DT and auxiliary electron switch S CR ' are connected on the overall network contact PE of total protective circuit ZB " and between the protective grounding PE; the sub-network contact A of sub-protective circuit ZB/3 can directly or through electromagnet DT link to each other with the live wire L ' of single phase distribution system; the overall network contact A1 of total protective circuit ZB; A2; A3 and three-phase power distribution system live wire L1 '; L2 '; L3 ' is directly corresponding to link to each other; link to each other with three-phase power distribution system zero line N ' or the N other end and three-phase firewire L1 ' or L2 ' or L3 ' of an additional resistance Rs ' end chooses at random one of them and links to each other; simulation experiment circuit is connected between the zero line N ' or N of the sub-network contact B of the overall network contact B ' of total protective circuit ZB or sub-protective circuit ZB/3 and distribution system, test resistance R _sBe connected between hookup and the t.a.

2. novel neutral line protector according to claim 1; it is characterized in that: three sub-network node PE ' of three groups of sub-protective circuit ZB/3 " link to each other; three sub-network node B of three groups of sub-protective circuit ZB/3 link to each other with the overall network contact B ' of total protective circuit ZB jointly three live wire inputs of three groups of sub-protective circuit ZB/3 three overall network contact A of sub-network contact A and total protective circuit ZB with the overall network contact PE of total protective circuit ZB jointly ₁, A ₂, A ₃Optionally corresponding linking to each other.

3. novel neutral line protector according to claim 1 is characterized in that: the input of the rectification circuit among the sub-protective circuit ZB/3 is connected in parallel on sub-network contact A, the B two ends, the shunt resistance R among the sub-protective circuit ZB/3 _FBe connected in parallel on the output of rectification circuit, the gate leve g of the electronic switch SCR among the sub-protective circuit ZB/3 is through filter resistance R _LLink to each other with negative pole end among the rectification circuit output end with the series circuit of voltage offset circuits DB3; the negative electrode k of electronic switch SCR among the sub-protective circuit ZB/3 links to each other with sub-network contact PE ' through the obstructive type anti-jamming circuit, and the anode a of the electronic switch SCR among the sub-protective circuit ZB/3 can link to each other with sub-network contact A and also can link to each other with the positive terminal among the rectification circuit output end.

4. novel neutral line protector according to claim 1; it is characterized in that: for the single phase distribution system; release electromagnet DT can be connected between live wire L ' and the sub-network contact A; or between the anode a of sub-network contact A and electronic switch SCR; or between the anode a or contact C of the cathode output end of rectification circuit and electronic switch SCR; or between the negative electrode k and obstructive type anti-jamming circuit of electronic switch SCR, or between obstructive type anti-jamming circuit and the protective grounding PE.