CN104198794A - Zero sequence current transformer wire-break detection and residual current detection circuit - Google Patents
Zero sequence current transformer wire-break detection and residual current detection circuit Download PDFInfo
- Publication number
- CN104198794A CN104198794A CN201410352201.8A CN201410352201A CN104198794A CN 104198794 A CN104198794 A CN 104198794A CN 201410352201 A CN201410352201 A CN 201410352201A CN 104198794 A CN104198794 A CN 104198794A
- Authority
- CN
- China
- Prior art keywords
- detection circuit
- resistance
- unit
- residual
- zero sequence
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Landscapes
- Measurement Of Current Or Voltage (AREA)
Abstract
The invention relates to a zero sequence current transformer wire-break detection and residual current detection circuit and aims at solving the problem of waveform distortion of the residual current picked up by a sampling unit. The zero sequence current transformer wire-break detection and residual current detection circuit comprises a constant-current unit for providing a constant current, an amplification unit for amplifying an input signal and the sampling unit for converting the current signal into a voltage signal; the two ends of the sampling unit are correspondingly connected with the positive and negative input ends of the amplification unit, respectively; the constant-current unit is connected to the input end of the amplification unit after being connected in parallel with the sampling unit; a switching unit is arranged between the constant-current unit and the amplification unit; besides, the detection circuit further comprises a control unit which is used for outputting a signal to switch on the switching unit if determining that the detected residual current value is zero and thus detecting the working condition of a zero sequence current transformer to decide to alarm or not, or outputting a signal to switch off the switching unit when the residual current value is non-zero and then comparing the residual current value with a standard value to decide to alarm or not.
Description
Technical field
The present invention relates to a kind of testing circuit, particularly a kind of zero sequence current mutual inductor break detection circuit and residual current detection circuit.
Background technology
Aftercurrent protecting equipment is for electric wiring is carried out to earth-fault protection, prevents equipment and electrical fire accident that earth-fault current causes, and also can be used to provides indirect contact protection to personal Danger Electric shock risk.And the core of Aftercurrent protecting equipment is zero sequence current mutual inductor break detection circuit and residual current detection circuit, be intended to monitor the duty of zero sequence current mutual inductor, this testing circuit is to need long-term moving in electrical network.And in existing Aftercurrent protecting equipment; whether break for detecting zero sequence current mutual inductor; steady current that can be additional certain is to sampling unit; and this electric current adds and is held on sampling unit always; can in electrical network, move for a long time; this will cause the bad zero sequence current mutual inductor of performance to be subject to the impact of extra current; the residual current waveform distortion that sampling unit is picked up; cause the most at last detecting exactly residual electricity flow valuve and cause the misoperation of protective device or unprotect action, this will bring major safety risks to the equipment of required protection.
Summary of the invention
In order to overcome the deficiency of the residual current waveform distortion that sampling unit picks up, the invention provides a kind of zero sequence current mutual inductor break detection circuit and residual current detection circuit.
The technical solution adopted in the present invention is: a kind of zero sequence current mutual inductor break detection circuit and residual current detection circuit, and it comprises constant current source unit, for steady current is provided, amplifying unit, for amplifying input signal, sampling unit, in order to convert current signal to voltage signal, the two ends of sampling unit respectively with amplifying unit just, negative input end is corresponding to be connected, it is characterized in that: after described constant current source unit is in parallel with sampling unit, be connected on the input end of amplifying unit, between constant current source unit and sampling unit, be provided with switch element, also comprise control module, for judging that the residual electricity flow valuve detecting is zero output signal actuating switch unit, thereby detect the duty of zero sequence current mutual inductor to judge whether to need warning, or residual electricity flow valuve is output signal cut-off switch unit of non-zero, with the size of comparison residual electricity flow valuve and standard value to judge whether to need warning.
Described amplifying unit comprises the first operational amplifier U1B, capacitor C 3, resistance R 4/R5/R6/R7/R8/R9, the positive input terminal 5 of the first operational amplifier U1B is by resistance R 8 ground connection, positive input terminal 5 is connected with bias voltage output terminal by resistance R 9, output terminal 7 by resistance R 6 and R7 as signal output residual, after the capacitance-resistance filter of the signal of output terminal 7 by R6 and C3 composition, after R7 current limliting, be connected with control module as signal output residual, output terminal 7 is connected with negative input end 6 by R4 again.
Described constant current source unit comprises the second operational amplifier U1A, resistance R 1/R2, voltage reference diode U3 and a N channel field-effect pipe Q1, one end ground connection after resistance R 2 and voltage reference diode U3 series connection, one termination VCC, on node between negative input end 2 connecting resistance R2 and the voltage reference diode U3 of the second operational amplifier U1A, positive input terminal 3 meets VCC by resistance R 1, the gate pole 1 of the one N channel field-effect pipe Q1 is connected with the output terminal 1 of the second operational amplifier U1A, drain electrode 2 is connected with positive input terminal 3, and source electrode 3 is connected with switch element.
Described switch element comprises the 2nd N channel field-effect pipe Q2 and resistance R 3, the gate pole 1 of the 2nd N channel field-effect pipe Q2 meets signal input AD_CTL to control break-make through resistance R 3, drain electrode 2 is connected with the source electrode 3 of a N channel field-effect pipe Q1, and source electrode 3 connects the negative input end 6 of the first operational amplifier U1B by resistance R 5.
Described sampling unit comprises zero sequence current mutual inductor in parallel and resistance R S1, and one end of sampling unit is connected with the negative input end 6 of the first operational amplifier U1B by resistance R 5, the other end ground connection of sampling unit.
Described control module adopts single-chip microcomputer, and described single-chip microcomputer is connected with the signal output residual of amplifying unit, is connected with the signal input AD_CTL of switch element.
Also comprise the voltage follower as bias voltage, the output terminal of described voltage follower is connected with the positive input terminal of amplifying unit by resistance R 9.
Described resistance R 5/R8 value is identical, and described resistance R 4/R9 value is identical.
Described sampling unit also comprises the capacitor C in parallel with resistance R S1 2.
Described sampling unit also comprises the clamping circuit in parallel with resistance R S1, and this clamping circuit is made up of two diode D1/D2 parallel connection of a positive and a negative.
The invention has the beneficial effects as follows: this zero sequence current mutual inductor break detection circuit and residual current detection circuit adopt being switched on or switched off of switch element control constant current source unit, adopt control module to judge that the residual electricity flow valuve detecting is zero output signal actuating switch unit, thereby detect the duty of zero sequence current mutual inductor to judge whether to need warning, or residual electricity flow valuve is output signal cut-off switch unit of non-zero, with the size of comparison residual electricity flow valuve and standard value to judge whether to need warning, so do not need in real time to the logical steady current of zero sequence current mutual inductor, avoid the impact of steady current on zero sequence current mutual inductor, make it occur the problem of residual current waveform distortion, can detect exactly residual electricity flow valuve, thereby this circuit does not propose special requirement to zero sequence current mutual inductor, there is practicality widely.
Brief description of the drawings
Fig. 1 is circuit block diagram of the present invention.
Fig. 2 is that constant current source unit of the present invention is connected with sampling unit by switch element, is connected on the circuit connection diagram of the negative input end of amplifying unit.
Fig. 3 is that constant current source unit of the present invention is connected with sampling unit by switch element, is connected on the circuit connection diagram of the positive input terminal of amplifying unit.
Fig. 4 is that constant current source unit of the present invention is connected with sampling unit by switch element, is connected on the circuit connection diagram of the positive input terminal of amplifying unit.
Embodiment
Below in conjunction with accompanying drawing, embodiments of the present invention is further illustrated:
As shown in Figure 1 and Figure 2,, a kind of zero sequence current mutual inductor break detection circuit and residual current detection circuit, it comprises that it comprises constant current source unit, for steady current is provided, amplifying unit, for amplifying input voltage, sampling unit, in order to convert current signal to voltage signal, the two ends of sampling unit respectively with amplifying unit just, negative input end is corresponding to be connected, after described constant current source unit is in parallel with sampling unit, be connected on the input end of amplifying unit, between constant current source unit and sampling unit, be provided with switch element, also comprise control module, for judging that the residual electricity flow valuve detecting is zero output signal actuating switch unit, thereby detect the duty of zero sequence current mutual inductor to judge whether to need warning, or residual electricity flow valuve is output signal cut-off switch unit of non-zero, with the size of comparison residual electricity flow valuve and standard value to judge whether to need warning.Control constant current source unit place in circuit or be disconnected from the circuit by the break-make of switch element, whether conducting connects normally to detect zero sequence current mutual inductor, disconnect the size to detect residual electricity flow valuve, by constant current source signal and residual current signal, the current signal after superimposed converts voltage signal to described sampling unit, the given circuit of the present invention does not need in real time to the logical steady current of zero sequence current mutual inductor, avoid the impact of steady current on zero sequence current mutual inductor, make it occur the problem of residual current waveform distortion, thereby zero sequence current mutual inductor is not proposed to special requirement, there is practicality widely.
Described control module adopts the PIC18F series monolithic of Microchip company, its operating voltage is by 5V voltage signal gained after the filtering of π type, certainly, the single-chip microcomputer of selecting other series but can realize technical scheme of the present invention is all fine, adopt single-chip microcomputer can detect exactly residual electricity flow valuve, and judge that whether residual electricity flow valuve is normal.
Circuit for alarming comprises the relay trip unit, audible alarm unit and the light warning unit that are connected with single-chip microcomputer respectively, if detect, zero sequence current mutual inductor does not connect or residual electricity flow valuve exceedes 1000mA, can relay trip unit, audible alarm unit and light warning unit be moved respectively by single-chip microcomputer, to make warning.
Described control module also can adopt comparer, and its operating voltage is 5V voltage signal.Default first standard signal that magnitude of voltage is 0 in the first comparer; be used for judging whether zero sequence current mutual inductor connects normally; default second standard signal that magnitude of voltage is corresponding with the residual current standard value of protective device in the second comparer; to adopt the circuit voltage signal and the second standard signal that collect to compare with the second comparer, thereby judge that whether residual electricity flow valuve is normal.
Described amplifying unit comprises the first operational amplifier U1B, capacitor C 3, resistance R 4/R5/R6/R7/R8/R9, the positive input terminal 5 of the first operational amplifier U1B is by resistance R 8 ground connection, positive input terminal 5 is connected with bias voltage output terminal by resistance R 9, output terminal 7 by resistance R 6 and R7 as signal output residual, after the capacitance-resistance filter of the signal of output terminal 7 by R6 and C3 composition, after R7 current limliting, be connected with control module as signal output residual, output terminal 7 is connected with negative input end 6 by R4 again; Described sampling unit comprises zero sequence current mutual inductor in parallel and resistance R S1, one end of sampling unit is connected with the negative input end 6 of the first operational amplifier U1B by resistance R 5, the other end ground connection of sampling unit, resistance after the internal resistance of sampling unit by resistance R S1 or zero sequence current mutual inductor is in parallel with resistance R S1, constant current source signal and residual current signal are thought to the current signal after stack converts voltage signal to, again after the first operational amplifier U1B amplifies, offer single-chip microcomputer, to judge duty and the residual electricity flow valuve of zero sequence current mutual inductor.
Described constant current source unit comprises the second operational amplifier U1A, resistance R 1/R2, voltage reference diode U3 and a N channel field-effect pipe Q1, one end ground connection after resistance R 2 and voltage reference diode U3 series connection, one termination VCC, on node between negative input end 2 connecting resistance R2 and the voltage reference diode U3 of the second operational amplifier U1A, positive input terminal 3 meets VCC by resistance R 1, the gate pole 1 of the one N channel field-effect pipe Q1 is connected with the output terminal 1 of the second operational amplifier U1A, drain electrode 2 is connected with positive input terminal 3, source electrode 3 is connected with switch element, from the source electrode 3 output current Is of a N channel field-effect pipe Q1.
Described switch element comprises the 2nd N channel field-effect pipe Q2 and resistance R 3, the gate pole 1 of the 2nd N channel field-effect pipe Q2 meets signal input AD_CTL to control break-make through resistance R 3, this signal input AD_CTL connects the common IO mouth of single-chip microcomputer, drain electrode 2 is connected with the source electrode 3 of a N channel field-effect pipe Q2, source electrode 3 connects the negative input end 6 of the first operational amplifier U1B by resistance R 5, export high level signal to gate pole 1 by single-chip microcomputer in good time, to control the break-make of the 2nd N channel field-effect pipe Q2, make switch element control constant current source unit whether access sampling unit, to realize the duty and the switching that detects residual electricity flow valuve function of electric circuit inspection zero sequence current mutual inductor.
Also comprise the voltage follower as bias voltage, described voltage follower comprises the 3rd operational amplifier U1C and resistance R 10/R11, one end ground connection after R10 and R11 series connection, one termination VCC, the positive input terminal 10 of the 3rd operational amplifier U1C is connected on the node between resistance R 10 and R11, negative input end 9 is connected with output terminal 8, output terminal 8 is bias voltage output terminal, output terminal 8 is connected with the positive input terminal 5 of the first operational amplifier U1B by resistance R 9, output terminal 8 output voltages of the 3rd operational amplifier U1C are Vref=1/2VCC, this output voltage is again after resistance R 8 and R9 dividing potential drop, give 5 one bias voltages of positive input terminal of the first operational amplifier U1B, the sine wave of residual current signal is moved on the whole, make it all within the scope of positive voltage, to solve because residual current signal is sinusoidal wave, the problem that negative voltage can not be identified by most of single-chip microcomputer, this bias voltage need be according to the difference of single-chip microcomputer operating voltage or AD reference voltage and difference.
Described sampling unit also comprises the capacitor C in parallel with resistance R S1 2; 4 pin of described the second operational amplifier U1A meet VCC, 11 pin ground connection, and connect capacitor C 1 between 4 pin and 11 pin, and capacitor C 1 is decoupling capacitor, has decoupling effect, capacitor C 2 is shunt capacitances, has filter action.
Described sampling unit also comprises the clamping circuit in parallel with resistance R S1; this clamping circuit is made up of two diode D1/D2 parallel connection of a positive and a negative; once can only there is a diode current flow; and another is in cut-off state; its forward and reverse pressure drop will be clamped at below the 0.5-0.7 of diode forward conduction voltage drop so, thereby plays the object of holding circuit.
Principle analysis:
The internal resistance of supposing zero sequence current mutual inductor is R=100 Ω, RS1=100 Ω, and R1=1k Ω, VCC=5V, the burning voltage of voltage reference diode U3 is 2.5V, constant current source electric current is Is=(VCC-2.5)/R1=2.5mA.
Get R5=R8=10k Ω, R4=R9=100k Ω, R10=R11=1k Ω, the output voltage of voltage follower is Vref=2.5V.
If residual electricity flow valuve Iresi=0mA that 1 single-chip microcomputer detects, now AD_CTL is high level, and the 2nd N channel field-effect pipe Q2 keeps on-state.
If a) zero sequence current mutual inductor connects normal, R // RS1=50 Ω, the voltage of R5 and C2 tie point is Vin=(R // RS1) * Is=50*2.5=125mV, the voltage of the output terminal 7 of the first operational amplifier U1B is Vout1=Vref – Vin* (R4/R5)=2.5V-1.25V=1.25V, and now single-chip microcomputer can detect that zero sequence current mutual inductor connects normally.
If b) zero sequence current mutual inductor does not connect, Vin=RS1*2.5=250mV, Vout2=Vref – Vin* (R4/R5)=2.5V-2.5V=0V.
C) analyze two kinds of situations above, their output voltage V out1 and Vout2 have obvious difference, and single-chip microcomputer can distinguish that whether zero sequence current mutual inductor connects normally, has completed broken string measuring ability according to this type of difference.
If d) single-chip microcomputer detects that mutual inductor connects normally, AD_CTL is low level, start to detect residual electricity flow valuve, if residual electricity flow valuve is greater than 0mA, continue to detect residual electricity flow valuve, if residual electricity flow valuve is 0mA, AD_CTL is high level, whether the 2nd N channel field-effect pipe Q2 keeps on-state, start to detect zero sequence current mutual inductor and connect.
If the residual electricity flow valuve Iresi > 0mA that 2 single-chip microcomputers detect, now AD_CTL is low level, the 2nd N channel field-effect pipe Q2 is in off-state, suppose that residual electricity flow valuve is 1A, coil ratio is 2000:1, the input current of circuit is 0.5mA, Vin=0.5*50=25mV, Vout=Vref – Vin* (R4/R5)=2.5V-0.25V=2.25V after amplifying.Gather aftertreatment through Chip Microcomputer A/D again; can obtain real residual electricity flow valuve, the residual current setting value of this residual electricity flow valuve and protective device be compared, if exceed setting value; should be judged as leak current fault, protective device should send chimes of doom or provide trip signal.
Relative, circuit involved in the present invention, if the voltage signal after sampling unit conversion is connected with the positive input terminal 5 of the first operational amplifier U1B, the negative input end 6 of the first operational amplifier U1B has two kinds of connections:
The first
As shown in Figure 3, voltage follower is connected with the negative input end 6 of the first operational amplifier U1B, so connect, the reference point of constant current source signal is to remain ground, and the reference point of sampling unit has become the output voltage V ref of voltage follower, this will cause electric current can not form loop, occur circuit mistake.
The second
As shown in Figure 4, do not access voltage follower, the negative input end 6 of the first operational amplifier U1B is by resistance R 57 ground connection, connect output terminal by resistance R 54, so connect, bias voltage using the voltage signal after sampling unit conversion as the first operational amplifier U1B, but this bias voltage just needs always in access state, otherwise just can only detect half-wave, and always in access state, long-time running like this, steady current will exert an influence to zero sequence current mutual inductor, make it occur the problem of residual current waveform distortion, can not detect exactly residual electricity flow valuve, unless ensured that zero sequence current mutual inductor performance used is good especially, but select the zero sequence current mutual inductor that performance is good can affect production cost and restrict the practical application of this circuit.
Below described embodiment is only the preferred embodiment of the present invention by reference to the accompanying drawings, and the not restriction to protection scope of the present invention, any improvement of doing based on spirit of the present invention all ought to be within protection domain of the present invention.
Claims (10)
1. zero sequence current mutual inductor break detection circuit and a residual current detection circuit, it comprises constant current source unit, for steady current is provided, amplifying unit, for amplifying input signal, sampling unit, in order to convert current signal to voltage signal, the two ends of sampling unit respectively with amplifying unit just, negative input end is corresponding to be connected, it is characterized in that: after described constant current source unit is in parallel with sampling unit, be connected on the input end of amplifying unit, between constant current source unit and sampling unit, be provided with switch element, also comprise control module, for judging that the residual electricity flow valuve detecting is zero output signal actuating switch unit, thereby detect the duty of zero sequence current mutual inductor to judge whether to need warning, or residual electricity flow valuve is output signal cut-off switch unit of non-zero, with the size of comparison residual electricity flow valuve and standard value to judge whether to need warning.
2. zero sequence current mutual inductor break detection circuit according to claim 1 and residual current detection circuit, it is characterized in that: described amplifying unit comprises the first operational amplifier U1B, capacitor C 3, resistance R 4/R5/R6/R7/R8/R9, the positive input terminal 5 of the first operational amplifier U1B is by resistance R 8 ground connection, positive input terminal 5 is connected with bias voltage output terminal by resistance R 9, output terminal 7 by resistance R 6 and R7 as signal output residual, after the capacitance-resistance filter of the signal of output terminal 7 by R6 and C3 composition, after R7 current limliting, be connected with control module as signal output residual again, output terminal 7 is connected with negative input end 6 by R4.
3. zero sequence current mutual inductor break detection circuit according to claim 1 and residual current detection circuit, it is characterized in that: described constant current source unit comprises the second operational amplifier U1A, resistance R 1/R2, voltage reference diode U3 and a N channel field-effect pipe Q1, one end ground connection after resistance R 2 and voltage reference diode U3 series connection, one termination VCC, on node between negative input end 2 connecting resistance R2 and the voltage reference diode U3 of the second operational amplifier U1A, positive input terminal 3 meets VCC by resistance R 1, the gate pole 1 of the one N channel field-effect pipe Q1 is connected with the output terminal 1 of the second operational amplifier U1A, drain electrode 2 is connected with positive input terminal 3, source electrode 3 is connected with switch element.
4. zero sequence current mutual inductor break detection circuit according to claim 1 and residual current detection circuit, it is characterized in that: described switch element comprises the 2nd N channel field-effect pipe Q2 and resistance R 3, the gate pole 1 of the 2nd N channel field-effect pipe Q2 meets signal input AD_CTL to control break-make through resistance R 3, drain electrode 2 is connected with the source electrode 3 of a N channel field-effect pipe Q1, and source electrode 3 connects the negative input end 6 of the first operational amplifier U1B by resistance R 5.
5. zero sequence current mutual inductor break detection circuit according to claim 1 and residual current detection circuit, it is characterized in that: described sampling unit comprises zero sequence current mutual inductor in parallel and resistance R S1, one end of sampling unit is connected with the negative input end 6 of the first operational amplifier U1B by resistance R 5, the other end ground connection of sampling unit.
6. according to the zero sequence current mutual inductor break detection circuit described in any one in claim 1-5 and residual current detection circuit, it is characterized in that: described control module adopts single-chip microcomputer, described single-chip microcomputer is connected with the signal output residual of amplifying unit, is connected with the signal input AD_CTL of switch element.
7. zero sequence current mutual inductor break detection circuit according to claim 6 and residual current detection circuit, it is characterized in that: also comprise the voltage follower as bias voltage, the output terminal of described voltage follower is connected with the positive input terminal of amplifying unit by resistance R 9.
8. zero sequence current mutual inductor break detection circuit according to claim 6 and residual current detection circuit, is characterized in that: described resistance R 5/R8 value is identical, and described resistance R 4/R9 value is identical.
9. according to the zero sequence current mutual inductor break detection circuit described in any one in claim 1-5 and residual current detection circuit, it is characterized in that: described sampling unit also comprises the capacitor C in parallel with resistance R S1 2.
10. according to the zero sequence current mutual inductor break detection circuit described in any one in claim 1-5 and residual current detection circuit, it is characterized in that: described sampling unit also comprises the clamping circuit in parallel with resistance R S1, this clamping circuit is made up of two diode D1/D2 parallel connection of a positive and a negative.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410352201.8A CN104198794A (en) | 2014-07-23 | 2014-07-23 | Zero sequence current transformer wire-break detection and residual current detection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410352201.8A CN104198794A (en) | 2014-07-23 | 2014-07-23 | Zero sequence current transformer wire-break detection and residual current detection circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN104198794A true CN104198794A (en) | 2014-12-10 |
Family
ID=52084108
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410352201.8A Pending CN104198794A (en) | 2014-07-23 | 2014-07-23 | Zero sequence current transformer wire-break detection and residual current detection circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104198794A (en) |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105425067A (en) * | 2015-11-19 | 2016-03-23 | 南京大全电气研究院有限公司 | Method for testing residual current protection electric appliance |
| CN105486971A (en) * | 2015-11-13 | 2016-04-13 | 浙江涵普电力科技有限公司 | Short circuit and open circuit state detection circuit for secondary side winding of current transformer |
| CN106019062A (en) * | 2016-07-29 | 2016-10-12 | 江苏益邦电力科技有限公司 | Residual current coil disconnection detection device and detection method thereof |
| CN108132426A (en) * | 2018-02-13 | 2018-06-08 | 国网江苏省电力有限公司无锡供电分公司 | Current transformer circuit supervision fail Alarm Detector |
| CN109116785A (en) * | 2018-09-28 | 2019-01-01 | 中国船舶重工集团公司第七0七研究所九江分部 | A kind of online self-test control circuit device of amplifier |
| CN109932558A (en) * | 2019-04-15 | 2019-06-25 | 苏州未来电器股份有限公司 | Magnetic based on the power supply of single positive supply modulates alternating current-direct current residual current detection system |
| CN109960240A (en) * | 2017-12-26 | 2019-07-02 | 宁波菲仕电机技术有限公司 | Wire breakage detector and method based on MCU analog interface wiring |
| CN110048608A (en) * | 2018-01-17 | 2019-07-23 | 罗姆股份有限公司 | Isolated synchronous rectification DC/DC converter |
| CN110082587A (en) * | 2019-04-23 | 2019-08-02 | 深圳供电局有限公司 | Detection circuit and multiple-limb identification device |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201001022Y (en) * | 2007-01-11 | 2008-01-02 | 常熟开关制造有限公司(原常熟开关厂） | Test device for aftercurrent simulation |
| KR20090014902A (en) * | 2007-08-07 | 2009-02-11 | 엘에스산전 주식회사 | Electricity meter with a function for detecting failure of current transformer |
| CN201887427U (en) * | 2010-12-22 | 2011-06-29 | 常熟开关制造有限公司(原常熟开关厂） | Residual current protection circuit breaker with communication and alarm functions |
| CN202488092U (en) * | 2011-10-26 | 2012-10-10 | 广东南冠电气有限公司 | Intelligent residual current protector used for low-voltage universal breaker |
| CN203310939U (en) * | 2013-06-19 | 2013-11-27 | 常熟开关制造有限公司(原常熟开关厂） | Transformer state detection device and circuit breaker |
| CN103852674A (en) * | 2012-11-30 | 2014-06-11 | 上海华建电力设备股份有限公司 | Residual current transformer secondary coil disconnection detection circuit |
| CN103906292A (en) * | 2012-12-28 | 2014-07-02 | 深圳市海洋王照明工程有限公司 | Constant-current circuit and LED light fixture |
| CN204065213U (en) * | 2014-07-23 | 2014-12-31 | 浙江天正电气股份有限公司 | Zero sequence current mutual inductor break detection circuit and residual current detection circuit |
-
2014
- 2014-07-23 CN CN201410352201.8A patent/CN104198794A/en active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201001022Y (en) * | 2007-01-11 | 2008-01-02 | 常熟开关制造有限公司(原常熟开关厂） | Test device for aftercurrent simulation |
| KR20090014902A (en) * | 2007-08-07 | 2009-02-11 | 엘에스산전 주식회사 | Electricity meter with a function for detecting failure of current transformer |
| CN201887427U (en) * | 2010-12-22 | 2011-06-29 | 常熟开关制造有限公司(原常熟开关厂） | Residual current protection circuit breaker with communication and alarm functions |
| CN202488092U (en) * | 2011-10-26 | 2012-10-10 | 广东南冠电气有限公司 | Intelligent residual current protector used for low-voltage universal breaker |
| CN103852674A (en) * | 2012-11-30 | 2014-06-11 | 上海华建电力设备股份有限公司 | Residual current transformer secondary coil disconnection detection circuit |
| CN103906292A (en) * | 2012-12-28 | 2014-07-02 | 深圳市海洋王照明工程有限公司 | Constant-current circuit and LED light fixture |
| CN203310939U (en) * | 2013-06-19 | 2013-11-27 | 常熟开关制造有限公司(原常熟开关厂） | Transformer state detection device and circuit breaker |
| CN204065213U (en) * | 2014-07-23 | 2014-12-31 | 浙江天正电气股份有限公司 | Zero sequence current mutual inductor break detection circuit and residual current detection circuit |
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105486971A (en) * | 2015-11-13 | 2016-04-13 | 浙江涵普电力科技有限公司 | Short circuit and open circuit state detection circuit for secondary side winding of current transformer |
| CN105425067A (en) * | 2015-11-19 | 2016-03-23 | 南京大全电气研究院有限公司 | Method for testing residual current protection electric appliance |
| CN106019062A (en) * | 2016-07-29 | 2016-10-12 | 江苏益邦电力科技有限公司 | Residual current coil disconnection detection device and detection method thereof |
| CN106019062B (en) * | 2016-07-29 | 2018-11-23 | 江苏益邦电力科技有限公司 | A kind of residual current coil breakage detection device and its detection method |
| CN109960240A (en) * | 2017-12-26 | 2019-07-02 | 宁波菲仕电机技术有限公司 | Wire breakage detector and method based on MCU analog interface wiring |
| CN110048608A (en) * | 2018-01-17 | 2019-07-23 | 罗姆股份有限公司 | Isolated synchronous rectification DC/DC converter |
| CN110048608B (en) * | 2018-01-17 | 2020-12-18 | 罗姆股份有限公司 | Isolated synchronous rectification DC/DC converter |
| CN108132426A (en) * | 2018-02-13 | 2018-06-08 | 国网江苏省电力有限公司无锡供电分公司 | Current transformer circuit supervision fail Alarm Detector |
| CN108132426B (en) * | 2018-02-13 | 2023-10-03 | 国网江苏省电力有限公司无锡供电分公司 | Alarm detector for broken line of current transformer |
| CN109116785A (en) * | 2018-09-28 | 2019-01-01 | 中国船舶重工集团公司第七0七研究所九江分部 | A kind of online self-test control circuit device of amplifier |
| CN109932558A (en) * | 2019-04-15 | 2019-06-25 | 苏州未来电器股份有限公司 | Magnetic based on the power supply of single positive supply modulates alternating current-direct current residual current detection system |
| CN110082587A (en) * | 2019-04-23 | 2019-08-02 | 深圳供电局有限公司 | Detection circuit and multiple-limb identification device |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104198794A (en) | Zero sequence current transformer wire-break detection and residual current detection circuit | |
| CN204065213U (en) | Zero sequence current mutual inductor break detection circuit and residual current detection circuit | |
| CN103063979B (en) | Load open-circuit detection circuit | |
| CN105098721B (en) | A kind of overvoltage crowbar and method of transverter submodule | |
| CN103499748A (en) | Online monitoring system of supercapacitor bank | |
| CN106058837A (en) | Line arrester leakage current detection device without isolation component | |
| CN202957575U (en) | Electric leakage breaker | |
| CN201408985Y (en) | Short-circuit protection circuit for switching power supply | |
| CN105277834A (en) | Detection circuit | |
| CN205232007U (en) | On -vehicle switching power supply operating condition indicating circuit | |
| CN207677431U (en) | A kind of overvoltage crowbar and Switching Power Supply | |
| CN104574770A (en) | Electrical fire monitoring detector with fault detection circuit | |
| CN108318720B (en) | A kind of bidirectional current detection amplifier | |
| CN102749502B (en) | Double-current comparison circuit for electric energy metering chip | |
| CN203881839U (en) | Frequency converter voltage monitoring circuit | |
| CN103683186B (en) | A kind of residual current circuit breaker with self-setting function | |
| CN105137268A (en) | Sampling circuit for residual current transformer | |
| CN109038506A (en) | The current foldback circuit of integrated linear compensation | |
| CN103256996A (en) | Temperature detector | |
| CN202948050U (en) | Alarm device of abnormal transformer current | |
| CN203572900U (en) | Broken line detection circuit for state grid special transformer collection terminal control circuit | |
| CN107422222B (en) | Detection circuit for judging whether fuse is good or not by photovoltaic inverter | |
| CN205157748U (en) | Fire control device power monitored control system data acquisition circuit | |
| CN205158598U (en) | Electric fire monitors detector with failure detector circuit | |
| CN107167678A (en) | A kind of multifunctional analogue signal Acquisition Circuit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20141210 |