CN102170105A - Ground fault protection type electronic tripper tripping device - Google Patents
Ground fault protection type electronic tripper tripping device Download PDFInfo
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Abstract
The invention discloses a ground fault protection type electronic tripper tripping device, which is characterized in that a power supply isolation device is connected between an output end of a current-voltage switching circuit and an input end of a low dropout linear regulator (LDO) on the basis of an existing single current transformer (CT) ground fault protection type electronic tripper tripping device, and an isolation type trip circuit is adopted as a trip circuit. By adopting the scheme, the power supply isolation device is connected between the output end of the current-voltage switching circuit and the input end of the LDO, thus realizing isolation of ground potentials between a microprocessor and the current-voltage switching circuit. The ground potentials between the microprocessor and the current-voltage switching circuit do not share a common reference point, thus a signal processing circuit is not required to use a high-accuracy difference amplifier to process signals, and a common amplifier can process current signals including ground signals. The high-accuracy difference amplifier is extremely more expensive than the common amplifier, therefore, the electronic tripper tripping device is lower in the overall cost.
Description
Technical field
The present invention relates to the electric equipment field,, be specifically related to the electronic type release of circuit breaker in particular for cutting off the circuit breaker of electric current.
Background technology
Breaker of plastic casing is a moulded case circuit breaker.Can be used to connect and the disjunction load circuit, also can be used to control the not motor of Fraquent start.Its function is equivalent to electrical appliance part or whole function summations such as knife switch, overcurrent relay, no-voltage relay, thermal relay and earth leakage protective device, is a kind of important protection electrical equipment in the low-voltage network.
The breaker of plastic casing of electron type uses instrument transformer to gather each phase current size, compares with set point, and microprocessor sends signal when current anomaly, makes electronic trip unit drive the operating mechanism action.
The electronic type release of breaker of plastic casing generally adopts the CT(current transformer) the power supply self-powered, the CT(current transformer) both as power supply power supply usefulness, also use as sample of signal; Therefore, CT(current transformer) between signal ground and the power supply ground common ground reference must be arranged.
At present, the electronic type molded case circuit breaker label of peddling on the market is a lot, and function difference is very big, generally all possesses overcurrent protection defencive function (the 4P product also comprises neutral line protection), has earth fault protection but differ to establish a capital; Therefore, according to whether having the earth fault protection function, electronic type release can be divided into two kinds on earth fault protection type and non-earth fault protection type; Wherein non-earth fault protection type product, the relative simple economy of its circuit design, volume is also less, and its circuit theory is as shown in Figure 1; The sort circuit structure is relatively independent because of its each phase current signal, obtains after the anti-phase amplification of full-wave rectification, so can't or be difficult to the signal after the rectification is carried out vector and computing is beneficial to earth fault protection.
Earth fault protection type product also can be divided into two types, and the first adopts twin coil CT design, and promptly fast saturated CT and signal divide with hollow CT to be opened, and is respectively applied for power supply power supply and sample of signal, and its typical circuit principle as shown in Figure 2; Though the sort circuit structure is easy to obtain the ground protection signal by each phase signals vector and computing, the CT design is the twin coil mode, and volume is bigger, and cost is higher; It two is single CT designs, and its typical circuit principle comprises four current transformer CT, signal sampling circuit as shown in Figure 3, signal processing circuit, current rectifying and wave filtering circuit, current-to-voltage converting circuit, low pressure difference linear voltage regulator LDO, trip circuit, and MCU microprocessor and peripheral peripheral circuit thereof; Each current transformer is series at respectively among A, B, C triple line and the neutral line N of electrical network main circuit, electric current to A, B, C triple line and neutral line N carries out the sensing conversion, realize induction of signal and circuit energy supply, the output of each current transformer connects current rectifying and wave filtering circuit, current-to-voltage converting circuit and low pressure difference linear voltage regulator successively, and the output of low pressure difference linear voltage regulator is system works voltage; Signal processing circuit comprises signal boost circuit and operational amplification circuit, the input of signal sampling circuit is connected to the sampling end of each current transformer, the output of signal sampling circuit is connected in the input of operational amplification circuit, the output of operational amplification circuit is connected to the input of signal boost circuit, the signal boost circuit is by being made up of every straight and pull-up resistor electric capacity, on to draw current potential be reference voltage V ref, realization is promoted to reference voltage V ref to the reference potential of amplifier signal by 0, and the output of signal boost circuit is connected to the AD thief hatch of microprocessor; The dropout output of microprocessor is connected to the trigger end of trip circuit, and when unusual condition appearred in the electrical network main circuit, microprocessor provided triggering signal to trip circuit, and load circuit is cut off in trip circuit work, and load is protected.In the signal sampling circuit, the end of the current transformer current sampling resistor Ra of each phase, Rb, Rc, Rn respectively with corresponding being connected of current sample end of each phase current mutual inductor, the other end then be connected to each other and with the end short circuit of ground signalling sample resistance Rf, form a common node; Ground signalling is obtained by ground signalling sample resistance Rf conversion, and the other end of ground signalling sample resistance Rf is connected with the middle common port of the rectification common port of current rectifying and wave filtering circuit.Sort circuit design, it adopts each phase CT current phasor and ground signalling is taken a sample, but because of single CT design, does not have common reference point between current signal ground and the power supply ground, the sampling processing of the earth signal that must employing difference amplifier can achieve a butt joint; But the requirement to operational amplifier is very high, must adopt high-precision special-purpose differential amplifier, can guarantee that signal waveform does not distort, and price is very expensive, and amplifier palpus dual power supply, and the power supply design is comparatively complicated.
In sum, non-its simplicity of design of earth fault protection type product, cost is lower, but its function is less, can't satisfy the demand of particular customer; Though twin coil design mode product has ground protection, must adopt twin coil CT, and the CT volume is bigger, cost is higher, and practical application face may be limited; Though the single CT design of difference amplifier type product must be adopted expensive special-purpose differential amplifier, cost is higher, the circuit structure complexity.
Summary of the invention
In order to solve the problems referred to above of prior art, the purpose of this invention is to provide the lower-cost earth fault protection type of a kind of integral body electronic type release.
To achieve these goals, the present invention adopts following technical scheme:
Earth fault protection type electronic type release comprises current transformer, signal sampling circuit, signal processing circuit, current rectifying and wave filtering circuit, current-to-voltage converting circuit, low pressure difference linear voltage regulator, trip circuit, microprocessor and peripheral peripheral circuit thereof; Current transformer be series at the electrical network main circuit respectively each mutually in, the output of current transformer connects current rectifying and wave filtering circuit, current-to-voltage converting circuit and low pressure difference linear voltage regulator successively, the output of low pressure difference linear voltage regulator is system works voltage; The current sample end of each phase current mutual inductor connects the input of signal sampling circuit, and the output of signal sampling circuit connects signal processing circuit and microprocessor successively, and the output of microprocessor connects the trigger end of trip circuit; Be connected with the isolated from power device between the output of above-mentioned current-to-voltage converting circuit and the input of above-mentioned low pressure difference linear voltage regulator.
Above-mentioned isolated from power device adopts DC-DC to isolate Voltage stabilizing module.
Above-mentioned trip circuit adopts the isolated form trip circuit.
Above-mentioned isolated form trip circuit adopts the light-coupled isolation trip circuit.
Above-mentioned signal processing circuit comprises voltage lifting circuit and operational amplification circuit, and the output of above-mentioned signal sampling circuit is connected in the input of above-mentioned operational amplification circuit, and the output of above-mentioned operational amplification circuit is connected to the input of above-mentioned microprocessor; Above-mentioned voltage lifting circuit is a reference voltage module, the input of said reference voltage module connects the output of above-mentioned low pressure difference linear voltage regulator, the output of said reference voltage module provides reference voltage, and this reference voltage is half of said system operating voltage.
Above-mentioned signal sampling circuit comprises each phase current mutual inductor current sampling resistor and ground signalling sample resistance, one end of above-mentioned each phase current mutual inductor current sampling resistor respectively with corresponding being connected of current sample end of each current transformer mutually, the other end of above-mentioned each phase current mutual inductor current sampling resistor then be connected to each other and with an end short circuit of above-mentioned ground signalling sample resistance, form a common node, the output of said reference voltage module connects common node so far, and the other end of above-mentioned ground signalling sample resistance is connected with the middle common port of the rectification common port of above-mentioned current rectifying and wave filtering circuit.
After adopting such scheme, the present invention has following beneficial effect:
One, the present invention increases between the input of the output of current-to-voltage converting circuit and low pressure difference linear voltage regulator the isolated from power device, realized earthy isolation between microprocessor and the current-to-voltage converting circuit, earth potential does not between the two have common reference point, signal processing circuit just need not adopt high-accuracy differential amplifier that signal is handled like this, general common amplifier just can realize current signal is comprised the processing of ground signalling, the price of high-accuracy differential amplifier and common amplifier differs a lot of, thereby makes that the whole cost of electronic trip unit of the present invention is lower.
Two, further, isolated from power device of the present invention adopts DC-DC to isolate the voltage stabilizing output module, it is a kind of high efficiency modularized dc voltage dropping power supply module that DC-DC isolates the voltage stabilizing output module, circuit such as built-in high frequency transformer, switching tube, pulse generation, have that volume is little, power density is high, the Surface Mount design is easy to advantages such as production, is particularly suitable for the occasion that volume size is had relatively high expectations.This DC-DC isolates the voltage stabilizing output module owing to adopt the Switching Power Supply design, has very high conversion efficiency, has further improved the operating efficiency of power supply; Because the power supply energy of electronic loop obtains from the CT current transformation, the CT electric current then derives from power network current, the size of power network current is directly proportional with the power of working power, thereby high efficiency DC-DC Voltage stabilizing module helps reduce to allow to work the power network current value, further enlarges the current work scope of electronic type release.
Three, further, the output of the reference voltage module of voltage lifting circuit with each mutually the common node of CT current sampling resistor be connected, directly CT voltage signal reference point is promoted to reference voltage value, and this reference voltage value equals system works voltage half, the sampling voltage signal of each CT will be between microprocessor earth potential and the system works voltage like this, but fluctuate with respect to the reference voltage value alternation, its waveform is consistent with the power network current waveform, therefore processing amplifier just can adopt single power supply, simplifies circuit design.
Four, further, described ground signalling sampling directly adopts the vector and the stack of each phase CT electric current to obtain, and obtains through ground signalling sampling resistor changing voltage; This mode can be simplified circuit, saves cost, avoid introducing complicated vector and computing circuit, and precision is also higher.
Description of drawings
Fig. 1 is the circuit theory diagrams of non-earth fault protection type electronic trip unit in the prior art;
Fig. 2 is the circuit theory diagrams of the earth fault protection type electronic trip unit of two CT designs in the prior art;
Fig. 3 is the circuit theory diagrams of the earth fault protection type electronic trip unit of single CT design in the prior art;
Fig. 4 is a circuit structure block diagram of the present invention;
Fig. 5 is circuit theory diagrams of the present invention.
Embodiment
Existing accompanying drawings and embodiment further describe in detail the present invention.
Earth fault protection type electronic trip unit of the present invention; shown in Fig. 4,5; comprise 4 silicon steel core current transformer CT, signal sampling circuit has the signal processing circuit of voltage lifting circuit and operational amplification circuit; current rectifying and wave filtering circuit; current-to-voltage converting circuit U1, DC-DC isolates Voltage stabilizing module U2, low pressure difference linear voltage regulator U3; light-coupled isolation trip circuit, MCU microprocessor and peripheral peripheral circuit thereof.
Each current transformer CT is series at respectively in A, B, C, the N phase line of electrical network main circuit, and each phase current of electrical network main circuit is carried out the sensing conversion, realizes induction of signal and circuit energy supply.
Current rectifying and wave filtering circuit is made up of ten bridge rectifier diode D1-D10, totally five groups, ac current source A, B, C, N to each phase current mutual inductor induction carries out rectification respectively, rectifier diode D9, D10 are the rectification common port, the current commutates of every phase current mutual inductor is made up of rectifier diode and public rectifier diode separately, and for example the rectification of A phase current mutual inductor is made up of rectifier diode D1, D2, D9, D10 etc.
The output of current transformer CT connects current rectifying and wave filtering circuit successively, current-to-voltage converting circuit U1, DC-DC isolate Voltage stabilizing module U2, direct current after the current rectifying and wave filtering circuit rectification converts direct voltage V0 to through current-voltage conversion circuit U1, this direct voltage is the voltage input source of DC-DC voltage isolation module U2, also provides power supply for the light-coupled isolation trip circuit simultaneously; Direct voltage V0 is converted to the voltage V1 of isolation through DC-DC voltage isolation module U2, the high efficiency modularized dc voltage dropping power supply module I B-LT-1W series that this DC/DC voltage isolation module U2 adopts Jin Shengyang company to produce, circuit such as built-in high frequency transformer, switching tube, pulse generation, have that volume is little, power density is high, the Surface Mount design is easy to advantages such as production, is particularly suitable for the occasion that volume size is had relatively high expectations.This DC-DC voltage isolation module U2 has very high conversion efficiency (representative value 70%) owing to adopt the Switching Power Supply design, has further improved the operating efficiency of power supply.Voltage V1 after the isolation is transformed into through low pressure difference linear voltage regulator U3 again can supply the system works voltage VCC of work such as microprocessor, operational amplification circuit.
The current sample end of each current transformer CT connects the input of signal sampling circuit, the input of the output concatenation operation amplifying circuit of signal sampling circuit, the output of operational amplification circuit is connected to the input of microprocessor, and the dropout output of microprocessor connects the trigger end of light-coupled isolation trip circuit.
Voltage lifting circuit is a reference voltage module, the input of this reference voltage module connects the output of low pressure difference linear voltage regulator U3, the output of this reference voltage module provides reference voltage V ref, and this reference voltage V ref is half of system works voltage vcc.
Signal sampling circuit comprises each phase current mutual inductor current sampling resistor Ra, Rb, Rc, Rn and ground signalling sample resistance Rf, current sampling resistor Ra, Rb, Rc, the end of Rn respectively with corresponding being connected of current sample end of each current transformer mutually, current sampling resistor Ra, Rb, Rc, the other end of Rn then be connected to each other and with the end short circuit of ground signalling sample resistance Rf, form a common node, the output of reference voltage module connects common node so far, connects the other end of signal of telecommunication sample resistance Rf and is connected with the middle common port of the rectification common port of current rectifying and wave filtering circuit (end points that rectifier diode D9 is connected with rectifier diode D10).
Among the present invention, current sampling signal Va, the Vb that sample resistance Ra, Rb, Rc, Rn obtain, Vc, Vn, Vf are ac voltage signal, can not satisfy the requirement of microprocessor AD conversion, the voltage signal of these alternations is converted to positive direct current alternating signal through voltage lifting circuit; This voltage lifting circuit directly is connected common node and obtains with system voltage benchmark Vref; This voltage reference Vref is obtained through reference voltage module U4 conversion by system voltage Vcc, and equals system voltage Vcc half, i.e. Vref=1/2*Vcc.
Operational amplification circuit mainly is made up of voltage follower U6A and in-phase amplifier U7A; Current sampling signal after voltage promotes, with respect to alternation about the voltage reference Vref, but its amplitude limitation is between 0-Vcc; Because system voltage Vcc isolates with current/voltage V0, make Signal Processing become very simple, each phase current signal Va, Vb, Vc, Vn need only follow through voltage follower U6A and get final product, and ground signalling Vf also need only amplify the requirement that just can satisfy microprocessor AD conversion through common in-phase amplifier U7A because of its signal is less relatively.
The light-coupled isolation trip circuit is made up of tripping coil RELAY, optocoupler P1, transistor Q1 and circuits for triggering etc.; Voltage V1 after DC/DC voltage isolation module U2 isolates is less, can not satisfy the job requirement of tripping coil RELAY, so its trip circuit power supply must adopt the V0 power supply, and microprocessor is isolated the control of threading off by optocoupler P1 to it; Its dropout actuating circuit is by tripping coil Relay, power transistor Q1, oppositely the receiving terminal etc. of sustained diode 12 and optocoupler P1 is formed; The dropout control circuit then is made up of transmitting terminal of microprocessor IO mouth, optocoupler P1 etc.; By the photoelectricity coupling, realize isolated controlling, Tripping Circuit.
Claims (6)
1. earth fault protection type electronic type release comprises current transformer, signal sampling circuit, signal processing circuit, current rectifying and wave filtering circuit, current-to-voltage converting circuit, low pressure difference linear voltage regulator, trip circuit, microprocessor and peripheral peripheral circuit thereof; Current transformer be series at the electrical network main circuit respectively each mutually in, the output of current transformer connects current rectifying and wave filtering circuit, current-to-voltage converting circuit and low pressure difference linear voltage regulator successively, the output of low pressure difference linear voltage regulator is system works voltage; The current sample end of each phase current mutual inductor connects the input of signal sampling circuit, and the output of signal sampling circuit connects signal processing circuit and microprocessor successively, and the output of microprocessor connects the trigger end of trip circuit; It is characterized in that: be connected with the isolated from power device between the output of above-mentioned current-to-voltage converting circuit and the input of above-mentioned low pressure difference linear voltage regulator.
2. earth fault protection type electronic type release according to claim 1 is characterized in that: above-mentioned isolated from power device adopts DC-DC to isolate Voltage stabilizing module.
3. earth fault protection type electronic type release according to claim 1 is characterized in that: above-mentioned trip circuit adopts the isolated form trip circuit.
4. earth fault protection type electronic type release according to claim 3 is characterized in that: above-mentioned isolated form trip circuit adopts the light-coupled isolation trip circuit.
5. earth fault protection type electronic type release according to claim 1, it is characterized in that: above-mentioned signal processing circuit comprises voltage lifting circuit and operational amplification circuit, the output of above-mentioned signal sampling circuit is connected in the input of above-mentioned operational amplification circuit, and the output of above-mentioned operational amplification circuit is connected to the input of above-mentioned microprocessor; Above-mentioned voltage lifting circuit is a reference voltage module, the input of said reference voltage module connects the output of above-mentioned low pressure difference linear voltage regulator, the output of said reference voltage module provides reference voltage, and this reference voltage is half of said system operating voltage.
6. earth fault protection type electronic type release according to claim 5; it is characterized in that: above-mentioned signal sampling circuit comprises each phase current mutual inductor current sampling resistor and ground signalling sample resistance; one end of above-mentioned each phase current mutual inductor current sampling resistor respectively with corresponding being connected of current sample end of each current transformer mutually; the other end of above-mentioned each phase current mutual inductor current sampling resistor then be connected to each other and with an end short circuit of above-mentioned ground signalling sample resistance; form a common node; the output of said reference voltage module connects common node so far, and the other end of above-mentioned ground signalling sample resistance is connected with the middle common port of the rectification common port of above-mentioned current rectifying and wave filtering circuit.
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| Application Number | Priority Date | Filing Date | Title |
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| CN2011101127504A CN102170105A (en) | 2011-05-03 | 2011-05-03 | Ground fault protection type electronic tripper tripping device |
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| CN2011101127504A CN102170105A (en) | 2011-05-03 | 2011-05-03 | Ground fault protection type electronic tripper tripping device |
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| CN2011101127504A Pending CN102170105A (en) | 2011-05-03 | 2011-05-03 | Ground fault protection type electronic tripper tripping device |
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Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102412555A (en) * | 2011-10-10 | 2012-04-11 | 厦门士林电机有限公司 | Novel grounding fault protection electrical apparatus release |
| CN102594113A (en) * | 2012-03-21 | 2012-07-18 | 绍兴文理学院 | Bearing cutting hardware power supply based on chart programming |
| CN102769267A (en) * | 2012-08-15 | 2012-11-07 | 王道连 | Intelligent flashy flow controller |
| CN104813556A (en) * | 2012-11-27 | 2015-07-29 | 伊顿电气Ip两合公司 | Switching device having a measuring apparatus |
| CN109375692A (en) * | 2018-11-08 | 2019-02-22 | 深圳航天科技创新研究院 | A kind of high-voltage linear source of stable pressure by current control |
| CN112255568A (en) * | 2020-10-21 | 2021-01-22 | 泉州睿泽恒创物联网科技有限公司 | High-sensitivity electric leakage detection system and detection method thereof |
| CN114389233A (en) * | 2020-10-16 | 2022-04-22 | Abb瑞士股份有限公司 | Current interrupter device |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201393051Y (en) * | 2009-04-07 | 2010-01-27 | 湖北盛佳电器设备有限公司 | Circuit breaker with protection function |
| CN201499018U (en) * | 2009-08-14 | 2010-06-02 | 国网电力科学研究院武汉南瑞有限责任公司 | Intelligent circuit breaker controller |
| CN201514560U (en) * | 2009-07-24 | 2010-06-23 | 德力西电气有限公司 | Circuit of intelligent plastic case relay controller |
| CN202084916U (en) * | 2011-05-03 | 2011-12-21 | 厦门士林电机有限公司 | Ground fault protection type electronic electrical apparatus release |
-
2011
- 2011-05-03 CN CN2011101127504A patent/CN102170105A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201393051Y (en) * | 2009-04-07 | 2010-01-27 | 湖北盛佳电器设备有限公司 | Circuit breaker with protection function |
| CN201514560U (en) * | 2009-07-24 | 2010-06-23 | 德力西电气有限公司 | Circuit of intelligent plastic case relay controller |
| CN201499018U (en) * | 2009-08-14 | 2010-06-02 | 国网电力科学研究院武汉南瑞有限责任公司 | Intelligent circuit breaker controller |
| CN202084916U (en) * | 2011-05-03 | 2011-12-21 | 厦门士林电机有限公司 | Ground fault protection type electronic electrical apparatus release |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102412555A (en) * | 2011-10-10 | 2012-04-11 | 厦门士林电机有限公司 | Novel grounding fault protection electrical apparatus release |
| CN102594113A (en) * | 2012-03-21 | 2012-07-18 | 绍兴文理学院 | Bearing cutting hardware power supply based on chart programming |
| CN102769267A (en) * | 2012-08-15 | 2012-11-07 | 王道连 | Intelligent flashy flow controller |
| CN104813556A (en) * | 2012-11-27 | 2015-07-29 | 伊顿电气Ip两合公司 | Switching device having a measuring apparatus |
| CN104813556B (en) * | 2012-11-27 | 2017-08-15 | 伊顿电气Ip两合公司 | Switching device with measuring instrument |
| CN109375692A (en) * | 2018-11-08 | 2019-02-22 | 深圳航天科技创新研究院 | A kind of high-voltage linear source of stable pressure by current control |
| CN109375692B (en) * | 2018-11-08 | 2020-11-24 | 深圳航天科技创新研究院 | High-voltage linear voltage stabilizing source controlled by current |
| CN114389233A (en) * | 2020-10-16 | 2022-04-22 | Abb瑞士股份有限公司 | Current interrupter device |
| CN112255568A (en) * | 2020-10-21 | 2021-01-22 | 泉州睿泽恒创物联网科技有限公司 | High-sensitivity electric leakage detection system and detection method thereof |
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