CN2311092Y

CN2311092Y - Pulse earth leakage protector

Info

Publication number: CN2311092Y
Application number: CN 97218573
Authority: CN
Inventors: 李玉泉; 王黎明
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-06-27
Filing date: 1997-06-27
Publication date: 1999-03-17
Anticipated expiration: 2007-06-27

Abstract

The utility model relates to a pulse earth leakage protector, composed of a zero sequence mutual inductor, a clamping circuit, a voltage division shaping circuit, a simulating thyristor circuit, a triggering circuit, a control circuit, a time delay reclosing circuit, a protecting circuit which protects forced power transmission, etc. A picked electric leakage and electric shock signal triggers an actuating mechanism to operate via an operational amplifier to cut off a power supply consequently. The utility model has the advantages of simple structure, compact structure, flexible action, and reliability.

Description

The pulse leakage protector

The utility model belongs to low pressure 220V-380V electric power earth leakage protective field.

The used pulsed protector of low-voltage network can only be suitable for the illuminating line protection at present, can not be used for power line.Because when institute's drive load is very big in switchgear house; the starting current of power-equipment is higher than the rated current several times during time-delay reclosing; can burn out control appliance and power consumption equipment; normal pulsed formula protector is because artificial origin during with the disconnection of zero-sequence transformer and electric power controller in addition, and protector is ineffective.

Order of the present utility model ground is: the pulse leakage protector that provides a kind of illumination, power protection to be integrated in one.

The purpose of this utility model is achieved in that

A kind of pulse leakage protector is by zero-sequence transformer, compositions such as operational amplifier and triode, diode, resistance, electric capacity; It is characterized in that: by diode D ₁, D ₂, and resistance R ₂-R ₃Constitute clamp circuit; Resistance R ₆, R ₇With capacitor C ₂Constitute dividing potential drop and shaping circuit, triode G ₂, G ₃Form the simulation controllable silicon, circuits for triggering are by resistance R ₁And operational amplifier IC ₁Form, control circuit is by operational amplifier IC ₁, IC ₂, IC ₃Resistance R ₈, capacitor C ₄, C ₅And diode D ₃Constitute; Prevent that the forced power transmission protective circuit from being by resistance R ₅, capacitor C ₃And triode G ₁Constitute; Time-delay reclosing circuit is by R ₁₂, C ₈, G ₃And relay J constitutes.

D in the described clamp circuit _{1, D2}Be connected anti-parallel to pair avris of zero-sequence transformer CT, R ₂, R ₃Respectively with IC ₁Same, reverse input end connect.

R in the described dividing potential drop shaping circuit ₇With C ₂Parallel connection, point in parallel respectively with G ₁Emitter and pass through R ₆With IC ₁Output connect.

The described R that prevents in the forced power transmission protective circuit ₅With C ₁₃Series connection constitutes differential circuit, one termination+12V power supply, another termination G ₁Base stage.

R in the described time-delay reclosing circuit ₁₂One termination D ₅, D ₆Negative terminal, the other end meets G respectively ₃Base stage and meet G by K switch ₂Collector electrode, G ₂Emitter succeed the coil of electrical equipment J, another termination of the coil of J+12V power supply, G ₂Base stage meet G ₃Collector electrode, C ₈Meet D ₅, D ₆Between output and the ground.

R in the described control circuit ₈, C ₆, C ₄Constitute integrating circuit, C ₆Be parallel to IC ₂Between ,+,-end, IC ₂, IC ₃Output meet D respectively ₅, D ₆Forward end, its negative end meets C jointly ₈With R ₁₂Tie point, D ₃, C ₅Meet G after the series connection respectively ₁Collector electrode and IC ₃Input in the same way.

The utility model is when detecting the zero-sequence transformer that the electric leakage circuit uses and well connect with the electronic controller that three groups of operational amplifiers are formed, leakage current makes operational amplifier upset trigger actuator, deenergization through long-pending with circuit differential circuit and inspection at the zero-sequence transformer secondary side output signal.As be used in when throwing light on, K switch disconnects by G ₂, G ₃The simulation controllable silicon G that triode is formed ₂Collector electrode.Pass through G ₃Time-delay reset is realized the reclosing function.As make power line protection switch K closure, trigger the simulation controllable silicon.Remove the reclosing function.

Below in conjunction with accompanying drawing: the utility model is further described with embodiment

C in the utility model ₁, C ₆, C ₇Be anti-interference capacitor, D ₁, D ₂, R ₂, R ₃Form clamp circuit, when preventing that CT from exporting strong signal to IC ₁Cause damage.R ₆, R ₇, C ₂Form IC ₁Dividing potential drop and shaping circuit during the output high potential, its course of work are achieved in that when protected circuit does not have electric leakage: the CT no-output, because the very little R of CT resistance ₁, R ₄Resistance is very big, and the CT both end voltage is approximately zero.IC ₁Do not overturn IC ₁Output is " 0 ".IC ₂, IC ₃The output of not overturning, protector is failure to actuate, and the normally closed point of relay J does not disconnect, and circuit just is being with power supply.If protected circuit hinders the CT of too low protector extremely can not power the time, if the electrician artificial CT and control circuit are disconnected, then+12V voltage passes through R ₁To IC ₁In-phase input end provides high potential, IC ₁Output is a high potential, and electric current is by integrating circuit R ₈C ₆, make IC ₂In-phase input end is " 1 " current potential, then IC ₂Output is " 1 " current potential, D ₅Conducting is to delay circuit C ₈Charging, C ₈Current potential rises to G ₃During conducting, there is electric current to pass through its normally closed point in the relay coil and disconnects.Stop to power to supply line.When not reaching electric leakage action setting value if protected circuit insulation against ground resistance is lower, the AC signal of CT output made IC when system sent electricity ₁Upset, but because moment when sending electricity+12V voltage passes through R ₅C ₃(moment is equivalent to short circuit) provides base current to G1, according to I _c=β .Ib.G ₁Conducting makes A point current potential, and clamper is in earth potential, IC ₂, IC ₃Do not overturn, the moment forced power transmission is owing to C in the extremely short time ₃The charging resistance finishes G ₁Become by conducting and to end, protector enters guard mode, though i.e. circuit insulation against ground resistance is lower, the unmanned electric shock when (sudden change pulse) also can normally be sent to supply line.Improved the electric rate of sending.If a nearly step of line electrical leakage increases, surpass when slowly leaking electricity setting value integrating circuit R ₈, C ₄C ₄Both end voltage rises, IC ₂Upset is through R ₁₁, D ₄Feedback loop is realized self-insurance, D ₅Conducting C ₈Current potential rises and makes G ₃Turn-on relay J action, its contact J disconnects and stopping power supply, if protector with starting the protection of line of force road then with the K switch closure, G when the K switch closure ₂G ₃Form the simulation controllable silicon, as protector action, C ₈Current potential rises and simulates controllable silicon realization self-sustaining, though C ₈Both end voltage descends, but protection K no longer overlaps.When K switch being disconnected then G if protector is used for illuminating line protection ₂C, b the knot be equivalent to the string at CT ₃A diode on the collector electrode, C ₈Both end voltage descends, R ₁₂In electric current less than G ₃, relay J discharged its contact J closure again when J kept electric current, realized the reclosing function.

If its pulse current that (contacts High Level AC Voltage suddenly) when someone gets an electric shock in the extremely short time (≤0.1S) make IC ₁Overturn its output through R ₆, D ₃, C ₅To IC ₃In-phase input end provides high potential, IC ₃The high potential of upset output is through D ₆, R ₁₂Make G ₃Conducting, its contact of actuating of relay J disconnects and stopping power supply.

Claims

1. a pulse leakage protector is by zero-sequence transformer, compositions such as operational amplifier and triode, diode, resistance, electric capacity; It is characterized in that: by diode D ₁, D ₂, and resistance R ₂-R ₃Constitute clamp circuit; Resistance R ₆, R ₇With capacitor C ₂Constitute dividing potential drop and shaping circuit, triode G ₂, G ₃Form the simulation controllable silicon, circuits for triggering are by resistance R ₁And operational amplifier IC ₁Form, control circuit is by operational amplifier IC ₁, IC ₂, IC ₃Resistance R ₈, capacitor C ₄, C ₅And diode D ₃Constitute; Prevent that the forced power transmission protective circuit from being by resistance R ₅, capacitor C ₃And triode G ₁Constitute; Time-delay reclosing circuit is by R ₁₂, C ₈, G ₃And relay J constitutes.

2. pulse leakage protector according to claim 1 is characterized in that: D in the clamp circuit _{1, D2}Be connected anti-parallel to pair avris of zero-sequence transformer CT, R ₂, R ₃Respectively with IC ₁Same, reverse input end connect.

3. pulse leakage protector according to claim 1 is characterized in that: the R in the dividing potential drop shaping circuit ₇With C ₂Parallel connection, point in parallel respectively with G ₁Emitter and pass through R ₆With IC ₁Output connect.

4. pulse leakage protector according to claim 1 is characterized in that: prevent the R in the forced power transmission protective circuit ₅With C ₁₃Series connection constitutes differential circuit, one termination+12V power supply, another termination G ₁Base stage.

5. pulse leakage protector according to claim 1 is characterized in that: R in the time-delay reclosing circuit ₁₂One termination D ₅, D ₆Negative terminal, the other end meets G respectively ₃Base stage and meet G by K switch ₂Collector electrode, G ₂Emitter succeed the coil of electrical equipment J, another termination of the coil of J+12V power supply, G ₂Base stage meet G ₃Collector electrode, C ₈Meet D ₅, D ₅Between output and the ground.

6. pulse leakage protector according to claim 1 is characterized in that: the R in the control circuit ₈, C ₆, C ₄Constitute integrating circuit, C ₆Be parallel to IC ₂Between ,+,-end, IC ₂, IC ₃Output meet D respectively ₅, D ₆Forward end, its negative end meets C jointly ₈With R ₁₂Tie point, D ₃, C ₅Meet G after the series connection respectively ₁Collector electrode and IC ₃Input in the same way.