CN1043230A - Vector difference type electric shock protector - Google Patents

Abstract

Vector difference type electric shock protector of the present invention is applicable to and takes place in the low-voltage network to protect when people, animal get an electric shock and line facility leaks electricity.Mainly by A.C. contactor, preface current transformer, electric protective device are controlled electronic component in addition, and a whole set of control circuit.Shell, panel are formed, and this electric protective device has solved earth leakage protective and the phasor difference electrical shock protection problem in the low voltage electric network, and it is highly sensitive that it has electric shock; and it is irrelevant with the electric leakage size of circuit; guarantee people, animal and device security, have the automatic reclosing function, improved operational percentage.Reduced the workload of safeguarding the electrician.

Description

Vector difference type electric shock protector

Vector difference type electric shock protector of the present invention is applicable to and takes place in the low-voltage network to protect when people, animal get an electric shock and line facility leaks electricity.Belong to residual current operated protective device.

At present both at home and abroad the earth leakage protective device that generally adopts with the size of leakage current (vector by the earth leakage protective device main circuit current and) as the action foundation; when taking place to get an electric shock in low-voltage network, in fact leakage current forms (seeing accompanying drawing 3) by two parts, and one of them is three-phase imbalance leakage current (I ^' _△), it two is human body shock current (I _CD), as resultant current (I _△) greater than the rated residual operating current (I of earth leakage protective device _{△ n}) time, the protector action is cut off the electricity supply.Theory and practice proves, because I ^' _△Existence, when people, animal get an electric shock, residual operating current (I _{△ n}) and make protector action and electric shock operating current (I by human body _CDQ) be not corresponding, its relational expression is expressed as follows:

$I_{\mathrm{C\; D\; Q}}=\sqrt{I^2{}_{\mathrm{△\; n}}\mathrm{-\; (I}{}^{，}{}_{△}\mathrm{S\; i\; n\; a\; )}{}^2}{\mathrm{-\; I}}_{△}\mathrm{\prime COS\alpha }$

By the not corresponding relation of following formula as can be known, shock current I _CDMust be greater than I _CDQEarth leakage protective device just moves.And in more occasion, although by human electric shock's electric current (I _CD) greater than I _{△ n}, but less than I _CDQProtector can not move, and promptly has insensitive operating dead zone or insensitive action phase.Especially in low pressure is got an electric shock net, because I _△Bigger than normal, at this moment guarantee power supply, I in order to improve operational percentage _{△ n}Must be greater than I ^' _△, so personal electric shock operating current must increase, and insensitive operating dead zone scope also enlarges, and the success rate of electrical shock protection will descend, and the operational percentage of protector and the success rate of electrical shock protection are the contradiction that earth leakage protective device is difficult for overcoming.

The vector difference type electric shock protector that the purpose of this invention is to provide a kind of novelty; solved earth leakage protective and the phasor difference electrical shock protection problem in the low voltage electric network; it is highly sensitive that it has electric shock; and and the electric leakage of circuit size is irrelevant; guarantee people, animal and device security; have the automatic reclosing function, improved operational percentage, reduced the workload of safeguarding the electrician.

The vector difference type electric shock protector primary structure is by A.C. contactor CJ.Other is preface current transformer CT.The shell of vector difference type electric shock protector electronic element circuit part and installation elements, panel etc. belong to the composite type protector.Electric leakage action indication light-emitting diode F is housed on the electric protective device panel ₁, relay indicating light F ₂, mains switch K, test button T, electric protective device shell lower end has power inleting terminal 3,4, output control terminal 1,2, the shell upper end has the input 4 ', 5 ' of electric shock signal input 1 ', 2 ' stimulus.A.C. contactor is connected in the power circuit; it is controlled by electric protective device; so that protected major loop is controlled, preface current transformer CT penetrates in the protected circuit in addition, leakage current in the protected circuit and shock current through it at secondary reflecting (USr).The wiring board that the vector difference type electric shock protector electronic component is assembled into is housed in the electric protective device shell.The electric protective device control circuit mainly is made of power unit, signal interference and amplifying circuit, earth leakage protective measurement and comparison circuit, phasor difference electrical shock protection measurement and comparison circuit, output control and automatic reclosing part, primary power transmission control circuit, electric shock test portion.

Power unit has: the step-down transformer B of accessory power supply, the elementary mains side that is connected to major loop, secondary mains switch K, the bridge rectifier D of being connected with ₁～D ₄, trifocal integrated voltage stabilizer SW, filter capacitor C ₁, C ₂C ₃, C ₄, C ₅, divider resistance R ₁, R ₂, by resistance R ₃, R ₄Operational amplifier S ₁Form 1/2 voltage divider that adopts operational amplifier.

Anti-interference and the amplifying circuit of signal has: the resistance R of filtering High-frequency Interference ₅, capacitor C ₆By resistance R ₆, R ₇, R ₈, R ₉, capacitor C ₇, C ₈, C ₉, C ₁₀, operational amplifier S ₂The active filter of the filtering high order harmonic component that constitutes, resistance R ₁₅R ₁₆R ₁₇, operational amplifier S ₃The linear amplifier of the amplifying signal that constitutes.

Earth leakage protective is measured with comparison circuit to be had: halfwave rectifier diode D ₅, by capacitor C ₁₅C ₁₆With resistance R ₁₈, R ₁₉The π type filter circuit that constitutes.By resistance R ₂₅Adjustable resistance W ₁Constitute the branch voltage regulator of comparative voltage, electric leakage is measured, comparator/operational amplifier S ₄, electric leakage action indicator F ₁, W ₁The rated residual operating current value is used for adjusting.

Comparison circuit is measured in the phasor difference electrical shock protection: by resistance R ₁₀, R ₁₁, R ₁₂R ₁₃Capacitor C ₁₁, C ₁₂, C ₁₃, C ₁₄With operational amplifier S ₅Constitute the active filter of choosing electric shock signal, by resistance R ₁₄, R ₂₁, R ₂₂, R ₂₃, R ₂₄, rectifier diode D ₆, D ₇Capacitor C ₁₇, operational amplifier, S ₆, S ₇The full-wave rectifying circuit that electric shock signal is become pulse signal that constitutes is by capacitor C ₁₈, resistance R ₂₆, R ₂₇Constitute pulse coupling circuit, by resistance R ₂₈, adjustable resistance W ₂The comparative voltage adjuster that constitutes.The measurement of shock current, comparison amplifier S ₈Form.The comparative voltage adjuster electric shock operating value that is used to adjust.

Output control and automatic reclosing part, diode D ₈, resistance R ₂₉Be electric leakage control input end, diode D ₉, resistance R ₃₂, R ₃₆For the electric shock control input end, by resistance R ₃₄, R ₃₅, capacitor C ₂₀, diode D ₁₀Constitute the reclosure time control circuit, control triode BG ₁, BG ₂, control transistor collector resistance R ₃₇Output control relay coil J ₁, its contact control A.C. contactor CJ, relay indicating light F ₂

Primary power transmission control circuit: by resistance R ₃₀, capacitor C ₁₉, resistance R ₃₁Constitute time control circuit and short circuit triode BG ₃, diode D ₁₁Constitute this circuit.Prevent the trip phenomenon immediately that the power turn-on K switch occurs when sending electricity.

The electric shock test portion is by test button T, test resistance R ₃₉Constitute.

Vector difference type electric shock protector comprises earth leakage protective and phasor difference electrical shock protection two parts.The human electric shock is taken place suddenly, and shock current is the phasor difference I of electric shock front and back leak electric current _△-I ^' _△=I _CD(accompanying drawing 3).Now select special phasor difference test circuit for use, directly record shock current (I _CD), because be the sudden change amount, so what record is variable quantity (having pulse character), it with get an electric shock before the size and the phase angle of leakage current irrelevant, as variable quantity (I _CD) greater than specified electric shock operating current (△ I _n) time, touch and protect the device action power dump, thus the protection personal safety, because of the survey variable quantity promptly reflects I _CDWith I ^' _△Irrelevant; so three-phase electric shock sensitivity unanimity; there are not insensitive operating dead zone or insensitive phase; still protect for the leakage current stable or that slowly change that line insulation or other reason cause with the earth leakage protective way; but so at this moment main consideration protection device security is specified electric leakage operating value (I _{△ n}) can increase, thereby guaranteed operational percentage.In order to reduce the workload of safeguarding the electrician and to improve operational percentage, electrical shock protection also is provided with the automatic reclosing function, when the person gets an electric shock; behind the protector action power dump; consider electric shock person active or passive disengaging power supply immediately, so, recover normal power supply through 30 seconds left and right sides automatic closings.If electric shock person does not break away from power supply in 30 seconds, then overlap back earth leakage protective automatically and move immediately, forever cut off the electricity supply to guarantee electric shock person's safety.Treat that the electrician restores electricity.In a word, utilize the phasor difference electrical shock protection to improve sensitivity (△ I _n), guarantee personal safety, utilize and reduce earth leakage protective sensitivity (as I _{△ n}＞100 milliamperes), to guarantee normal power supply, to have improved to put forward the fortune rate.In certain occasion, adopt vector difference type to touch and protect the effect that the device first class of protection can reach the earth leakage protective device second class protection, thus the economic benefit of obtaining.

Below with reference to accompanying drawing the present invention is described in further detail.

Fig. 1 is the vector difference type electric shock protector electrical schematic diagram.

Fig. 2 is that vector difference type electric shock protector is installed winding diagram.

Fig. 3 is the polar plot of electric leakage and shock current.

With reference to Fig. 1, Fig. 2 vector difference type electric shock protector primary structure by the electric protective device housing face-plate.A.C. contactor CJ.Preface current transformer CT in addition, and the vector difference type electric shock protector electronic element circuit partly constitutes.CJ is common A.C. contactor among the figure, and it is controlled by electric protective device, so that protected major loop is controlled, CT be penetrate the leakage current of protected circuit and shock current through it at secondary reflecting (USr); Remaining circuit is that vector difference type touches whole circuit of protecting device.B is the step-down transformer of accessory power supply, the elementary mains side that is connected to major loop, and the power turn-on K switch is connected the secondary low-voltage power supply, touches guarantor's device and promptly puts into operation, through K and bridge rectifier (D ₁～D ₄) obtain auxiliary direct current and press.C ₁, C ₄Be filter capacitor, through trifocal integrated voltage stabilizer SW, output obtains the galvanic current source, supplies with operational amplifier S ₁Use C with other circuit ₃Be filter capacitor, in the time of through voltage stabilizing main circuit voltage being changed in+10%～-15% scope, guarantee to touch measuring circuit and other control circuit of protecting device and can accurately work, could work because of operational amplifier needs duplicate supply, so utilize R ₁, R ₂Direct voltage is divided into up and down half and half, through R ₃, R ₄And S ₁, make S ₁The current potential of output all the time with R ₁, R ₂The current potential unanimity of tie point, thereby the duplicate supply that single supply is become ± equate, for all operational amplifier operate as normal, C ₄, C ₅Being the further filtering of duplicate supply, more than is the accessory power supply part.During power turn-on K switch bringing normally into operation, transistor BG ₁Be in cut-off state, BG ₂Through R ₃₇Obtain the base flow saturation conduction, relay J is inhaled moving, light-emitting diode F ₂Bright (work indication), the normal opened contact closure of relay J, main circuit power supply is connected in the adhesive of control A.C. contactor.

After measurement, comparison circuit and protection course of action: CJ work are devoted oneself to work, the leakage current (I of the output USr reflection protected circuit of CT _△), USr is through R ₅, C ₆Deliver to by R after the filtering High-frequency Interference ₆, R ₇, R ₈, R ₉, C ₇, C ₈, C ₉C ₁₀With operational amplifier S ₂The active filter of forming, its effect is the filtering high order harmonic component.Can reach the purpose that improves certainty of measurement and interference free performance like this, R ₁₅, R ₁₆R ₁₇And S ₃Form inverting amplifier, multiplication factor by Determine that its effect is to amplify electric leakage signal, its output size and dynamic range will guarantee with leakage current linear relationship is arranged, and amplifier does not occur saturated or ends when allowing the maximum leakage current that occurs.Through S ₃Amplifying signal divides two-way output; One the tunnel is earth leakage protective, and another road is the phasor difference electrical shock protection.Earth leakage protective is by semiconductor diode D ₅The leakage current signal is carried out halfwave rectifier, through R ₁₈R ₁₉, C ₁₅, C ₁₆Obtain more level and smooth direct current, pass through R ₂₀Be connected to by S ₄The self-locking comparison circuit of forming, S ₄"-" is connected to W ₁, pass through W ₁Adjust earth leakage protective specified electric leakage operating value (I _{△ n}), when normally moving, S ₄"-" terminal potential is higher than the current potential of leakage current signal input part "+" end, so S ₄The output electronegative potential.Leakage current slowly increases for a certain reason and reaches or greater than I in protected circuit _{△ n}The time, through D ₅Send into S ₄"+" terminal voltage will be higher than "-" end comparing voltage value, S ₄Output becomes high potential by electronegative potential, simultaneously through F ₁The light-emitting diode feedback no longer is subjected to D ₅The influence of output remains S ₄The output high potential reaches self-locking, simultaneously F ₁Shinny, expression is touched and is protected the action of device earth leakage protective.S ₄The high potential D of output ₈, R ₂₉Be BG ₁Its BG is provided ₁Saturation conduction makes BG ₂End relay indicating light F ₂Go out, J discharges, and A.C. contactor CJ discharges thereupon, cuts off main circuit power supply, reaches the earth leakage protective purpose, after this must be by safeguarding that the electrician will touch guarantor's appliance mains switch K earlier and open in order to restore electricity, and the K that closes again after getting rid of line fault eliminates then F as fault ₂Shinny, the J action, the CJ adhesive restores electricity, and more than is the earth leakage protective measuring circuit and the course of work.

The phasor difference electrical shock protection circuit and the course of work, USr is through S ₂, S ₃After the amplification, another road is sent into by R ₁₀, R ₁₁, R ₁₂, R ₁₃, C ₁₁, C ₁₂, C ₁₃, C ₁₄And S ₅The active filter of forming is when normally moving, for leakage current stable and that slowly change, although S ₃Input signal is arranged, through active filter S ₅Output then be almost other.When protected circuit takes place to get an electric shock, shock current I _CDBe the sudden change amount, USr reflects immediately, after amplifying by S ₅The active filter of forming promptly has and I _CDCorresponding power frequency component output, this exports via S ₆, S ₇And relevant circuit (R ₁₄, R ₂₁, R ₂₂, R ₂₃, R ₂₄, D ₆, D ₇, D ₁₇) full-wave rectifying circuit formed obtains a negative pulse, this pulse duration, maximum amplitude was corresponding with the shock current size about 30 milliseconds.Negative pulse is through C ₁₈, R ₂₇To comparator S ₈"-" end, S ₈"+" end is input as comparative voltage, adjusts W ₂Can change specified electric shock operating current (△ I _n) absolute value of the negative pulse that causes when shock current is greater than S ₈When "+" holds the absolute value of comparative voltage, comparator S ₈Output become high potential (promptly sending a positive pulse) by electronegative potential, positive pulse is through D ₉, R ₃₂, R ₃₆Give BG ₁Provide base flow, BG ₁Conducting, BG ₂End F ₂Go out, J discharges, and the CJ dead electricity is cut off main circuit power, protection electric shock person.At this moment, positive pulse makes BG ₁Conducting short but work as BG ₁Conducting BG ₂After ending, D.C. regulated power supply will be through R ₃₄, R ₃₅, C ₂₀, R ₃₆, BG ₁The be C that becomes a partner ₂₀Charging, charging current can be kept BG ₁Continue conducting, BG ₂End, protected circuit keep to have a power failure, and at this moment electric shock person can be initiatively or passive disengaging power supply, through about 30 seconds, and C ₂₀Charging current reduces BG gradually ₁End BG ₂Conducting, F ₂Shinny, the J adhesive overlaps automatically, and CJ closes a floodgate and recovers to send electricity, the course of work of electrical shock protection that Here it is and automatic reclosing.

Short circuit triode BG ₃Effect be when guaranteeing the power turn-on K switch; protected circuit obtains power supply immediately; its process is as follows; when the K that closes, J, CJ adhesive power supply; because of total some leakage current of protected circuit; when CJ adhesive power supply produced leakage current, USr was reflected as the sudden change amount of growing out of nothing, so S when just having sent electricity ₅Power frequency component output is arranged, through full-wave rectification S ₈Promptly having positive pulse sends.But this moment, positive pulse can be to BG ₁Have an effect, because at this moment K just closes, DC power supply will be through R ₃₀, C ₁₉, BG ₃The be C that becomes a partner ₁₉Charging, charging current makes BG ₃Saturation conduction.BG ₃Ce knot between be equivalent to short circuit, the positive pulse short circuit that caused by leakage current when just sending electricity can not cause BG ₁Conducting, BG ₂End, also just guaranteed line electrical leakage stream when allowed band, the K that the closes success of just once powering.

Winding diagram is installed in use with reference to Fig. 2 phasor difference electric protective device.This protector uses in the transformer neutral point grounding system, and the neutral line of protected circuit does not allow iterative earthing.

Vector difference type electric shock protector shell lower end power inleting terminal 3,4 inserts power supply B, C phase; end of incoming cables 1,2 is connected on A.C. contactor CJ coil in order to the A.C. contactor opening and closing; shell upper end terminals 1 ', 2 ' are connected on the output with CT level of other preface instrument transformer; terminals 4 ', 5 ' are that the stimulus input links to each other with the CT input; in addition the preface current transformer penetrates in the protected circuit, leakage current in the protected circuit and shock current through it at secondary reflecting (USr).Light-emitting diode F is housed on the electric protective device panel ₁, relay indicating light F ₂, mains switch K, test button T.After electric protective device installation wiring finishes, power turn-on K switch .F ₂(red) lamp is bright, CJ adhesive power supply.In service as line electrical leakage stream I _△Surpass volume and protect device rated residual operating current (I _{△ n}) time, touch the F that protects device ₂(red) lamp goes out F ₁(green) lamp is bright immediately, and CJ discharge to cut off power supply, safeguards that the electrician protects the above-mentioned reflection of device and can determine that protected circuit has fault according to touching, and opens K immediately, and the process circuit troubleshooting K that closes that finishes can recover normal operation, power supply.In when, electric shock taking place or pressing test button (T) when, F ₂Go out, CJ discharges; Stop power supply immediately, through about 30 seconds, overlap F automatically ₂Bright, restore electricity; If electric shock person does not break away from or fault does not disappear during overlapping, then overlap the back and will cut off the electricity supply F by the earth leakage protective effect rapidly once more ₂(red) lamp goes out F ₁(green) lamp is bright, and this moment is the same with the electric leakage action protection, needs just can restore electricity by safeguarding after the electrician handles.

Vector difference type electric shock protector is compared with existing protector has following characteristics:

1, phasor difference principle, electric shock action sensitivity height (△ I are adopted in electrical shock protection_nGet 30 milliamperes), any phase shock current surpasses 30 milliamperes, touch protect device can be in 0.1 second (comprise CJ release time) cut off the protected circuit power supply, have the automatic reclosing performance, can reduce the workload of safeguarding the electrician and improve operational percentage.

2, rated residual operating current is obtained big (I_△n=200 milliamperes), can make the tactile device of protecting in the bigger situation of distribution line insulaion resistance low-leakage current, guarantee normal power supply. Improve the power supply rate, cooperated with highly sensitive electrical shock protection like this, filled a phasor difference electric protective device at backbone or the total outlet of transformer, can reach the effect that present earth leakage protective device is installed the two-stage protection.

Getting the J relay when 3, normally moving is attracting state, rather than release conditions. When touching guarantor's device accessory power supply or other fault, J discharges immediately and cuts off the protected circuit power supply like this. Inform and safeguard that the electrician in time repairs electric protective device; if thereby the confidence level J that has improved protector adopts at ordinary times release conditions; then when all accessory power supplys or other fault; though do not affect power supply; but when protected circuit take place to get an electric shock or leakage current when surpassing working value; thereby J can not inhale moving can't cutting off the electricity supply, and the protection person and device security have lost the effect of protector.

Claims (2)

1, a kind of have A.C. contactor CJ, a preface current transformer CT in addition ₁Electric protective device control electronic component, circuit pack, is characterized in that the vector difference type electric shock protector that the shell of installation elements, panel constitute:

Electric leakage action indication light-emitting diode F is housed on the vector difference type electric shock protector panel ₁, relay indicating light F ₂, mains switch K, test button T, electric protective device shell lower end have power inleting terminal 3,4, output control terminal 1,2, the shell upper end have electric shock signal input 1 ', 2 ', the input 4 ', 5 ' of stimulus;

The vector difference type electric shock protector control circuit mainly by power unit, signal is anti-interference and amplifying circuit, earth leakage protective measurement and electrical equipment relatively, phasor difference electrical shock protection measurement and comparison circuit, output controls and automatic reclosing part, primary power transmission control circuit, electric shock test portion constitute.

A, power unit have the step-down transformer B of accessory power supply, the elementary mains side that is connected to major loop, secondary mains switch K, the bridge rectifier D of being connected with ₁～D ₄, trifocal integrated voltage stabilizer SW, filter capacitor C ₁, C ₂, C ₃, C ₄, C ₅, divider resistance RR ₂, by resistance R ₃, R ₄Operational amplifier S ₁Form, adopt 1/2 voltage divider of operational amplifier;

B, signal is anti-interference and amplifier has: the resistance R of filtering High-frequency Interference ₅, capacitor C 6 is by resistance R ₆, R ₇, R ₈, R ₉Capacitor C ₇, C ₈, C ₉, C ₁₀Operational amplifier S ₂Active filter, the resistance R of the filtering high order harmonic component that constitutes ₁₅, R ₁₆R ₁₇, operational amplifier S ₃The linear amplifier of the amplifying signal that constitutes;

C, earth leakage protective measure and comparison circuit has: halfwave rectifier diode D ₅, by capacitor C ₁₅, C ₁₆With resistance R ₁₈, R ₁₉Constitute Type filtering electrical equipment, by resistance R ₂₅, adjustable resistance W ₁Constitute the branch voltage regulator of comparative voltage, electric leakage is measured, comparison operation amplifying circuit S ₄, electric leakage action indicator F ₁

D, phasor difference electrical shock protection are measured comparison circuit and are: by resistance R ₁₀, R ₁₁, R ₁₂, R ₁₃, capacitor C ₁₁, C ₁₂, C ₁₃, C ₁₄With operational amplifier S ₅Constitute the active filter of choosing electric shock signal, by resistance R ₁₄, R ₂₁, R ₂₂, R ₂₃, R ₂₄Rectifier diode D ₆, D ₇Capacitor C ₁₇Operational amplifier S ₆, S ₇Constitute electric shock signal is become the full-wave rectifying circuit of pulse signal, by capacitor C ₁₈Resistance R ₂₆, R ₂₇Constitute pulse coupling circuit, by resistance R ₂₈Adjustable resistance W ₂The comparative voltage adjuster that constitutes, the measurement comparison amplifier S of shock current ₈Form;

E, output control and automatic reclosing part: diode D ₈, resistance R ₂₉Be electric leakage control input end, diode D ₉, resistance R ₃₂, R ₃₆For the electric shock control input end by resistance R ₃₄, R ₃₅, capacitor C ₂₀, diode D ₁₀Constitute the reclosure time control circuit, control triode BG ₁, BG ₂, control transistor collector resistance R ₃₇Output control relay coil J ₁, its contact control A.C. contactor CJ, relay indicating light F ₂

F, primary power transmission control circuit are by resistance R ₃₀, capacitor C ₁₉, resistance R ₃₁Constitute time control circuit, short circuit triode BG ₃, diode D ₁₁Constitute.

G, electric shock test portion be by test button T, test resistance R ₃₉Constitute.

2, vector difference type electric shock protector according to claim 1 is characterized in that A.C. contactor is connected in the power circuit, and preface current transformer CT penetrates in the protected circuit in addition.