CN2857212Y - Intelligent leakage protector - Google Patents

Abstract

An intelligent leakage current protector belongs to three-pole apparatus, which solves the misoperation caused by unable to distinguish the natural leakage current from the shocking leakage current. The intelligent leakage current protector is constituted of a current sensor, an amplifier, a SCM, breaker coils and contacts, and an auxiliary power supply. The characters lie in that, firstly, detecting the leakage current instantaneously and storing the result after the breaker contacts connecting the line; then, real-time detecting the leakage current and storing the results; finally, subtracting the instantaneous leakage current from the real-time leakage current, cutting off the current if the difference is larger than 30mA, or replacing the instantaneous leakage current periodically if the difference is less than 30mA. The leakage current protector has wide working voltage range without blind area in the protecting area, cut off the current only when shocking leakage current occurs, which is applicable for using with other protection functions.

Description

Intelligent earth leakage protective device

Technical field

The invention belongs to low pressure three electric appliances, be mainly concerned with phase line (or neutral line) and the natural leakage current between the ground and a kind of earth leakage protective device of personal electric shock leakage current of 220V uniline.

Background technology

According to (GB16917-1997) the specified residue operating current of 5.2.2 regulation 0.03A of State Standard of the People's Republic of China's " general requirement of RCD ", in fact be meant personal electric shock leakage current, be intended to protect personal safety.At present; the earth leakage protective device that all disclose the 0.03A earth leakage protective device of known document bulletin and just use 0.03A on market; all can't accurately test personal electric shock leakage current; can only test the leakage current in the circuit; just natural leakage current between phase line (or neutral line) and the ground and personal electric shock leakage current can't be distinguished circuit natural leakage current and personal electric shock leakage current.The technical problem of bringing thus is, aging circuit, and air humidity increases, and the long grade of line arrangement all makes the natural leakage current in the circuit increase, and may make the earth leakage protective device malfunction and line disconnection; Or the circuit natural leakage current adds interference signal, during 30 milliamperes of current values of overshoot, may make the earth leakage protective device malfunction and line disconnection.Aging circuit is relevant with the time limit, and air humidity is relevant with the area, and line arrangement length is relevant with area, if fundamentally can not distinguish circuit natural leakage current and personal electric shock leakage current.Frequent malfunction will influence people's normal electricity consumption.Now, the earth leakage protective device that design and installation prevents 30 milliamperes of person electric shocks is just refused in some cities, China south.In addition, the power supply of all 30 milliamperes of earth leakage protective devices all can not provide enough energy or leakage current detected value inaccurate between low-voltage AC100V-AC50V at present, causes the person then not line disconnection of tripping of getting an electric shock, and makes the protection zone have " dead angle ".

Summary of the invention

In order to overcome above deficiency, intelligent earth leakage protective device provided by the invention can be distinguished circuit natural leakage current and personal electric shock leakage current, only when person electric shock or unexpected electric leakage or earth fault, the ability line disconnection, the general influence that is not subjected to leakage currents such as humidity, line arrangement length, aging circuit, when if really the natural leakage current that is caused by external condition is greater than the limiting value of regulation, equally also line disconnection; This earth leakage protective device operating supply voltage scope is at AC50V-AC380V; and under different voltages, call different subprograms; make the protection zone not stay " dead angle "; rare tripping or malfunction; antijamming capability is stronger; can widen overvoltage and the under voltage protection scope of being applied to, can also unite with short circuit, overload protective device and use integrated protections such as forming short circuit, overload, electric leakage, ground connection, overvoltage, under voltage, can be widely used in each department.

Intelligent earth leakage protective device is made up of current sensor, amplifier, single-chip microcomputer, breaker coil, breaker contact, power supply.It is characterized by, the output of current sensor is connected amplifier input terminal, the output of amplifier is connected the input of the single-chip microcomputer that is built-in with AD converter and program, the output of single-chip microcomputer is connected the breaker coil, the breaker coil circuit is by Electromagnetic Control breaker contact, the breaker contact is connected in the phase line circuit, is connected amplifier and single chip circuit by the power circuit of capacitance decompression bridge rectifier; Above-mentioned single-chip microcomputer has the two-way input, and one road input is connected the output of amplifier, the size of detection line leakage current value, and another road input is connected the output of breaker contact, judges whether relay contact disconnects; Above-mentioned power circuit is the power circuit to the direct step-down rectifier voltage stabilizing of line voltage distribution dual output loop, and wherein one road power supply connects amplifier and single chip circuit, and another road power supply connects the breaker coil circuit; On the basis of this hardware circuit, realized when the breaker contact is connected circuit by the program in the single-chip microcomputer, by leakage current in the single-chip microcomputer moment detection line and store this leakage current value, when the circuit normal power supply, by leakage current value in the real-time detection line of single-chip microcomputer and store this current value, deduct the leakage current value of instantaneous detection by the leakage current value of real-time detection, if difference is greater than 30 MAHs, open-circuit line then is if difference, is then regularly replaced the leakage current value that moment detects less than 30 MAHs.

Description of drawings

Below in conjunction with drawings and Examples the utility model is further specified.

Fig. 1 is the technical characterictic figure that the hardware circuit of this use novel intelligent earth leakage protective device connects.

Fig. 2 is the Single Chip Microcomputer (SCM) program flow chart of this use novel intelligent earth leakage protective device.

Fig. 3 is the circuit diagram of this use novel intelligent earth leakage protective device embodiment.

Fig. 1 label is: (1) transducer, (2) amplifier, (3) single-chip microcomputer, (4) breaker coil, (5) power circuit, (6) breaker contact.

Embodiment

In Fig. 1, the output of current sensor (1) is connected the input of amplifier (2), the output of amplifier (2) connects the input of single-chip microcomputer (3), the output of single-chip microcomputer (3) is connected breaker coil (4), breaker contact (6) is connected in the phase line circuit, and power circuit (5) is connected amplifier (2) and single-chip microcomputer (3) and breaker coil (4) circuit.

Fig. 2 is the Single Chip Microcomputer (SCM) program flow chart, at first, when breaker contact (6) is connected circuit, by leakage current in single-chip microcomputer (3) the moment detection line and store this leakage current value, then, when the circuit normal power supply, by the real-time leakage current value and store this current value in the detection line of single-chip microcomputer (3), at last, deduct the leakage current value of instantaneous detection by the leakage current value of real-time detection, if difference during, then open-circuit line greater than setting, if difference during less than setting, is then regularly replaced the leakage current value that moment detects.

Fig. 3 is the embodiment schematic diagram according to Fig. 1 and Fig. 2 design.Further specify below in conjunction with embodiment Fig. 3, when the closure state of K contact, after DPJ single-chip microcomputer 6 pin test closure signal, leakage current signal in the current circuit that DPJ single-chip microcomputer 7 pin have obtained being amplified by G current sensor senses and Q30 triode, program in the DPJ single-chip microcomputer is done storage, comparison, is analyzed current line electrical leakage stream, drive J breaker coil by DPJ single-chip microcomputer 3 foot control system Q50 triodes then, make K breaker contact disjunction circuit, the DF diode shows current state simultaneously.Particularly, power supply passes through the C10 capacitance decompression, the D1-D4 bridge rectifier, and Q20, the voltage stabilizing of the DZ20 first order and DZ21, the voltage stabilizing of the D20 second level make line voltage distribution in the AC50V---AC380V scope, and its DC power supply is exported stable DC24V and DC5V respectively.

(1) when the K contact closure, the DPJ single-chip microcomputer is made comparisons to current leakage current value and predefined natural leakage current limiting value, if greater than set point, the DPJ single-chip microcomputer is by 3 pin output high level, drive J breaker coil by the Q50 triode, make K breaker contact disjunction circuit, simultaneously, show current state by the DF diode, earth fault or the line insulation layer serious electric leakage of this function when starting shields; (2) when the K contact closure, the DPJ single-chip microcomputer is made comparisons to current leakage current value and predefined natural leakage current limiting value, if less than set point, the DPJ single-chip microcomputer will be stored current natural leakage current value, 3 pin output low levels of DPJ single-chip microcomputer, promptly be regardless of the broken string road, the DF diode shows current state simultaneously.(3) on the basis of above-mentioned (2); DPJ single-chip microcomputer 7 pin carry out (circulation) in real time to current line electrical leakage stream and detect; leakage current value to real-time detection is stored; then; leakage current value with real-time detection deducts the natural leakage current value; if its difference is greater than 30 milliamperes set point; then DPJ single-chip microcomputer 3 pin drive J breaker coil by the Q50 triode; make K breaker contact disjunction circuit; the DF diode shows current state simultaneously; electric leakage shields this function to the accident in the circuit, and for example, the person gets an electric shock; the line insulation layer damages suddenly; unexpected electric leakage such as line-to-ground fault.(4) on the basis of above-mentioned (2), DPJ single-chip microcomputer 7 pin carry out (circulation) in real time to current line electrical leakage stream and detect, leakage current value to real-time detection is stored, then, deduct the natural leakage current value with the leakage current value that detects in real time, if its difference is less than 30 milliamperes set point, to continue to detect in real time, when the time of real-time detection arrives preset value, real-time detected leakage current value will be replaced the natural leakage current value of having stored, as new natural leakage current value.(5) continue to repeat the process of (1), (2), (3), (4), this process can effectively prevent by the electric leakage naturally of aging circuit, throughout the year air humidity varies leaking electricity naturally of electric leakage, southern and northern air humidity varies naturally and cause the malfunction of earth leakage protective device.

Fig. 3 label: AC AC power, DC DC power supply, I phase line, the N neutral line, L low-frequency choke, C electric capacity, the TVS bipolar diode, D diode, DZ voltage stabilizing didoe, R resistance, Q triode, the DPJ single-chip microcomputer, DF light-emitting diode, J breaker coil, K breaker contact, G transducer.

The technical characterstic of this intelligent earth leakage protective device and function

(1) when phase line generation earth fault, then disconnects supply line.

(2) ground connection being taken place and electric current surpasses 30 MAHs when the neutral line, then disconnects supply line.

(3) when the person gets an electric shock, then disconnect supply line.

(4) when leaking electricity, the line insulation layer acquires a certain degree, then open-circuit line.

(5) operating voltage AC50V-AC380V.

(6) consumed power is less than 1W.

(7) bearing transient overvoltage impacts smaller or equal to 4.5KV.

This intelligent earth leakage protective device widen application

Because in this technical scheme; one tunnel sampling end (R60 among the embodiment and D60) of directly taking from line voltage distribution is arranged; single-chip microcomputer is handled in real time to this voltage; can realize when line voltage distribution surpasses setting setting; then disconnect supply line's (title overvoltage protection), also can realize when line voltage distribution is lower than setting of setting, then disconnecting supply line's (title under voltage protection); therefore, can realize under voltage protection.All right, utilize the branch deenergizing in test circuit in this technical scheme and overload, the short-circuit protector, two parts circuit is joined together, and can realize transshipping, a kind of integrated protection of short circuit, personal electric shock, ground connection, overvoltage, under voltage.

This intelligent earth leakage protective device has stronger antijamming capability

This technical scheme compares, analyzes the increase antijamming capability by current sampling signal and voltage sampling signal two-way again except that having increased the antijamming capability by distinguishing circuit natural leakage current and personal leakage current.Because the line electrical leakage that single-chip microcomputer samples stream signal, it is a dynamic direct current signal, parameters such as rising edge, crest, trailing edge, trough, frequency are promptly arranged, simultaneously, the line voltage signal that offers single-chip microcomputer also has parameters such as rising edge, crest, trailing edge and zero, by the comparison of two paths of signals parameter, can accurately differentiate attributes such as capacitive electric leakage, perception electric leakage, resistive electric leakage, non-50HZ electric leakage, accurately differentiate the electric leakage attribute, can increase antijamming capability.Also lay a good foundation for the processing mode of phase demodulation, amplitude discrimination, frequency discrimination, phase demodulation amplitude discrimination.

The above, it only is preferred embodiment of the present invention, be not that this method is invented pro forma restriction, every technical scheme according to this method design, equal the feature of personal leakage current value by testing leakage current value that the leakage current value that has real-time detection really deducts instantaneous detection, can be considered and be equal to replacement, all belong to technical solution of the present invention.

Claims (3)

1 one kinds of intelligent earth leakage protective devices are made up of current sensor, amplifier, single-chip microcomputer, breaker coil, breaker contact, power circuit; It is characterized by, the output of current sensor is connected amplifier input terminal, the output of amplifier is connected the input of the single-chip microcomputer that is built-in with AD converter and program, the output of single-chip microcomputer is connected the breaker coil, the breaker contact is connected in the phase line circuit, and power circuit is connected amplifier and single chip circuit.

2 intelligent earth leakage protective devices according to claim 1, it is characterized in that: single-chip microcomputer has the two-way input, and one road input is connected the output of amplifier, and another road input is connected the output of breaker contact.

3 intelligent earth leakage protective devices according to claim 1 is characterized in that: to the direct step-down rectifier voltage stabilizing of line voltage distribution and export the two-way power supply, one road power supply connects amplifier and single chip circuit, and another road power supply connects breaker coil circuit.

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