CN106711932A - DC side ground fault protection device in DC power supply system - Google Patents
DC side ground fault protection device in DC power supply system Download PDFInfo
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- CN106711932A CN106711932A CN201710005148.8A CN201710005148A CN106711932A CN 106711932 A CN106711932 A CN 106711932A CN 201710005148 A CN201710005148 A CN 201710005148A CN 106711932 A CN106711932 A CN 106711932A
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- operational amplifier
- oxide
- metal
- leakage current
- semiconductor
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/08—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to excess current
- H02H3/087—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to excess current for dc applications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/08—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to excess current
- H02H3/10—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to excess current additionally responsive to some other abnormal electrical conditions
- H02H3/105—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to excess current additionally responsive to some other abnormal electrical conditions responsive to excess current and fault current to earth
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- Emergency Protection Circuit Devices (AREA)
Abstract
The invention discloses a DC side ground fault protection device in a DC power supply system. The DC side ground fault protection device comprises a DC contactor, a leakage current sensor, a sampling resistor, an amplifying circuit, a comparison circuit and a lockout circuit, wherein one end of the DC contactor is connected with an output end of a DC power supply, and the other end is connected with a load by means of the leakage current sensor; an output end of the leakage current sensor is connected with the sampling resistor; the amplifying circuit is connected with the output end of the leakage current sensor, and is used for amplifying a leakage current signal; the comparison circuit is used for receiving the amplified leakage current signal transmitted by the leakage current sensor, and comparing the amplified leakage current signal with a set threshold value to form comparison output; and the lockout circuit is used for receiving the comparison output, and controls the on-off of the DC contactor by means of the comparison output. The DC side ground fault protection device can perform inverse time limit protection according to magnitude of the leakage current, thereby fully guaranteeing personal safety, being capable of avoiding misoperation, and effectively improving the sensitivity and reliability of leakage protection.
Description
Technical field
The present invention relates to a kind of electric power system protection device, and in particular to the DC side ground connection in a kind of DC power-supply system
Failure protecting device.
Background technology
Earth leakage protective concerning personal safety, in high-voltage direct current, once occur earth fault, even if electric current is very micro-
It is small, it is still to cut off circuit as early as possible, in order to avoid cause personal injury accidents.Therefore during DC ground fault protection is high-voltage direct current
Indispensable protection.
Existing earth leakage protective is mainly used in AC system, when there is short trouble, by circuit breaker trip short circuit
Branch road, is protected, so as to ensure that the power supply of system other parts do not broken down is unaffected；When there is earth fault
When, protected by earth leakage circuit-breaker.When the effect of earth leakage circuit-breaker is the earth current for experiencing very little, you can do
Go out reaction, cut-out ground connection branch road, the Main Function of this protection is to ensure that personal safety；When human contact is to exchange live wire,
Live wire and the earth constitute loop by human body, and because human body resistance is larger, electric current is smaller in loop, but very little is flowed through on human body
Electric current just may be fatal, it is therefore desirable to be equipped with earth leakage circuit-breaker, the electric current of the earth flowed to for detecting, electric current exists when normal
Live wire and it is leading between flow, electric current is not had and enters the earth, once finding there is the Weak current that flows to the earth, earth leakage protective is opened
Close with regard to starting protection, cut-out electric leakage branch road.
Due to detection earth current is an AC current transformer, is only able to detect alternating current.Work as electric power system
During for HVDC, what direct current anode or negative terminal were produced after human body grounding is DC current, such AC current transformer without
Method detects DC leakage electric current, causes earth leakage protective failure.
Application No. 201410059669.8 discloses a kind of DC leakage current detection with protection circuit and detection and protection
Method, using for detecting the output current of dc source and the detection circuit of input current difference, difference signal amplifies and compares
Circuit, relay interlocking and IGCT (controllable silicon) control protection electric circuit, DC leakage protection test circuit.What the present invention was provided
Method is suitable only for the situation of low current and low-voltage.High-power circuit for high-voltage great-current is not appropriate for.
Application No. 201520896813.3 discloses a kind of device for measuring DC line Ground leakage current, the device bag
Include electric current supercircuit, the first DC leakage current transformer, the second DC leakage current transformer, subtraction circuit and signal
Conversion module.Although the present invention expands range of application using sensor, then difference is calculated using two outputs of sensor
The method error of value is larger.Compared to leakage current, line circuit is a very big value, is tied as detection with the difference of two big numbers
Really, its error will be very big in theory, and this will directly affect its protection result.
The content of the invention
The present invention is to overcome earth leakage protective in the prior art to ask straight-flow system medium sensitivity and reliability be not high
A kind of topic, there is provided the DC side earth-fault protection in DC power-supply system, can be carried out according to the size of leakage current
Inverse time-lag protection, so as to fully ensure that personal safety, it is possible to avoid misoperation, effectively raises earth leakage protective sensitivity
And reliability.
DC side earth-fault protection in a kind of DC power-supply system of present invention offer, including D.C. contactor,
Leakage current sensor, sampling resistor, amplifying circuit, comparison circuit and exclusive circuit, D.C. contactor one end are defeated with dc source
Go out end to be connected, the other end is connected by leakage current sensor with load；The output end of leakage current sensor is connected with sampling resistor,
For leakage current signal to be changed into magnitude of voltage；Amplifying circuit is connected with the output end of leakage current sensor, for by leakage current
Signal amplifies, and the leakage current signal after amplification is sent into comparison circuit；Comparison circuit is used to receive leakage current sensor biography
Leakage current signal after the amplification sent, and compare with the threshold value of setting, comparator output is formed, and comparator output is sent to
Locking circuit；Locking circuit compares output for reception, and by comparing the switch of output control D.C. contactor.
DC side earth-fault protection in a kind of DC power-supply system of the present invention, it is preferred that,
Amplifying circuit is made up of the first operational amplifier, first resistor and second resistance；The positive input of the first operational amplifier connects
Ground is simultaneously connected with sampling resistor one end, and the reverse input end of the first operational amplifier is connected with the sampling resistor other end, the first fortune
The reverse input end for calculating amplifier is grounded by first resistor, the reverse input end of the first operational amplifier by second resistance with
The output end of the first operational amplifier is connected, and the output end of the first operational amplifier is connected with comparison circuit.
DC side earth-fault protection in a kind of DC power-supply system of the present invention, it is preferred that,
Comparison circuit is made up of the second operational amplifier, the 3rd operational amplifier, 3rd resistor and reference power source；Second operational amplifier
Positive input be connected with the output end and the 3rd operational amplifier reverse input end of the first operational amplifier, the second computing is put
The reverse input end of big device is connected with reference power source positive pole, and the output end of the second operational amplifier is connected with 3rd resistor, and second
The output end of operational amplifier is connected with exclusive circuit, positive input and the reference power source negative pole phase of the 3rd operational amplifier
Even, the reverse input end of the 3rd operational amplifier and the positive input of the second operational amplifier and the first operational amplifier is defeated
Go out end to be connected, the output end of the 3rd operational amplifier is connected with exclusive circuit.
DC side earth-fault protection in a kind of DC power-supply system of the present invention, it is preferred that,
Exclusive circuit is by the 4th resistance, the 5th resistance, the 6th resistance, the 7th resistance, the 8th resistance, the first metal-oxide-semiconductor, the second metal-oxide-semiconductor,
Three metal-oxide-semiconductors, the first triode and the second triode composition；First metal-oxide-semiconductor G grades is connected with comparison circuit output end, the first metal-oxide-semiconductor
D grades is connected with by the 4th resistance with positive source, and first metal-oxide-semiconductor D grades is connected by the 5th resistance with second metal-oxide-semiconductor G grades, the
One metal-oxide-semiconductor S grades of ground connection, first metal-oxide-semiconductor S grades connects with the 3rd metal-oxide-semiconductor S-phase, and first metal-oxide-semiconductor S grades passes through the 6th resistance and the 2nd MOS
Pipe D grades is connected, and second metal-oxide-semiconductor S grades is connected with positive source, and G grades of the second metal-oxide-semiconductor is connected with the first triode ground level, and second
G grades of metal-oxide-semiconductor is connected by with the 7th resistance with positive source, and D grades of the 3rd metal-oxide-semiconductor is connected with the first triode ground level, the
The emitting stage ground connection of one triode, the colelctor electrode of the first triode is connected by the 8th resistance with the ground level of the second triode, the
The emitting stage of two triodes is connected with positive source, and the colelctor electrode of the second triode is connected with D.C. contactor.
The present invention, positive-negative power line also cross sensor, is so passed using the DC current sensor of Hall effect
The difference of the electric current on simply positive and negative two line that sensor is detected, that is, DC leakage current.In use, sensor
Output enter filtering and amplifying circuit, its alternating component is filtered by low pass filter, so remaining is exactly DC leakage current,
Output it and access comparator anode through delay circuit, the negative terminal of comparator connects rotection thresholds, when leakage current value is more than protection threshold
During value, comparator is output as height, protection act, and locks protection through exclusive circuit, is gone up again until after manual reset or power-off
Electricity.
The present invention can carry out inverse time-lag protection according to the size of leakage current, so as to fully ensure that personal safety, and can
To avoid misoperation, earth leakage protective sensitivity and reliability are effectively raised.
Brief description of the drawings
Fig. 1 is the DC side earth-fault protection schematic diagram in a kind of DC power-supply system.
Fig. 2 is a kind of circuit diagram of the DC side earth-fault protection amplifying circuit in DC power-supply system.
Fig. 3 is a kind of circuit diagram of the DC side earth-fault protection comparison circuit in DC power-supply system.
Fig. 4 is a kind of circuit diagram of the DC side earth-fault protection locking circuit in DC power-supply system.
Reference：U1, the first operational amplifier；U2, the second operational amplifier；U3, the 3rd operational amplifier；Vth, ginseng
Examine power supply；R1, first resistor；R2, second resistance；R3,3rd resistor；R4, the 4th resistance；R5, the 5th resistance；R6, the 6th electricity
Resistance；R7, the 7th resistance；R8, the 8th resistance；MOS1, the first metal-oxide-semiconductor；MOS2, the second metal-oxide-semiconductor；MOS3, the 3rd metal-oxide-semiconductor；Q1,
One triode；Q2, the second triode.
Specific embodiment
Embodiment 1
As shown in figures 1-4, the present invention provides the DC side earth-fault protection in a kind of DC power-supply system, bag
Include D.C. contactor, leakage current sensor, sampling resistor, amplifying circuit, comparison circuit and exclusive circuit, D.C. contactor one end
It is connected with DC power output end, the other end is connected by leakage current sensor with load；The output end of leakage current sensor with
Sampling resistor is connected, for leakage current signal to be changed into magnitude of voltage；Amplifying circuit is connected with the output end of leakage current sensor,
For leakage current signal to be amplified, and the leakage current signal after amplification is sent to comparison circuit；Comparison circuit is used to receive leakage
Leakage current signal after the amplification of current sensor transmission, and compare with the threshold value of setting, comparator output is formed, and will compare
Device output is sent to locking circuit；Locking circuit compares output for reception, and by comparing output control D.C. contactor
Switch.
Amplifying circuit is made up of the first operational amplifier U1, first resistor R1 and second resistance R2；First operational amplifier
The positive input ground connection of U1 is simultaneously connected with sampling resistor one end, the reverse input end and sampling resistor of the first operational amplifier U1
The other end is connected, and the reverse input end of the first operational amplifier U1 is grounded by first resistor R1, the first operational amplifier U1's
Reverse input end is connected by second resistance R2 with the output end of the first operational amplifier U1, the output of the first operational amplifier U1
End is connected with comparison circuit.
Comparison circuit is by the second operational amplifier U2, the 3rd operational amplifier U3,3rd resistor R3 and reference power source Vth groups
Into；The positive input of the second operational amplifier U2 is anti-with the output end and the 3rd operational amplifier U3 of the first operational amplifier U1
It is connected to input, the reverse input end of the second operational amplifier U2 is connected with reference power source Vth positive poles, the second operational amplifier
The output end of U2 is connected with 3rd resistor R3, and the output end of the second operational amplifier U2 is connected with exclusive circuit, and the 3rd computing is put
The positive input of big device U3 is connected with reference power source Vth negative poles, and the reverse input end of the 3rd operational amplifier U3 and second is transported
The output end of the positive input and the first operational amplifier U1 of calculating amplifier U2 is connected, the output end of the 3rd operational amplifier U3
It is connected with exclusive circuit.
Exclusive circuit is by the 4th resistance R4, the 5th resistance R5, the 6th resistance R6, the 7th resistance R7, the 8th resistance R8, first
Metal-oxide-semiconductor MOS1, the second metal-oxide-semiconductor MOS2, the 3rd metal-oxide-semiconductor MOS3, the first triode Q1 and the second triode Q2 composition；First MOS
G grades of pipe MOS1 is connected with comparison circuit output end, D grades of the first metal-oxide-semiconductor MOS1 with by the 4th resistance R4 positive source phases
Even, D grades of the first metal-oxide-semiconductor MOS1 is connected by the 5th resistance R5 with G grades of the second metal-oxide-semiconductor MOS2, the S of the first metal-oxide-semiconductor MOS1
Level ground connection, S grades of the first metal-oxide-semiconductor MOS1 connects with the S-phase of the 3rd metal-oxide-semiconductor MOS3, and S grades of the first metal-oxide-semiconductor MOS passes through the 6th resistance
R6 is connected with D grades of the second metal-oxide-semiconductor MOS2, and S grades of the second metal-oxide-semiconductor MOS2 is connected with positive source, the G of the second metal-oxide-semiconductor MOS2
Level is connected with the ground level of the first triode Q1, and G grades of the second metal-oxide-semiconductor MOS2 is connected by with the 7th resistance R7 with positive source,
D grades of 3rd metal-oxide-semiconductor MOS3 is connected with the ground level of the first triode Q1, the emitting stage ground connection of the first triode Q1, the first three-level
The colelctor electrode of pipe Q1 is connected by the 8th resistance R8 with the ground level of the second triode Q2, the emitting stage and power supply of the second triode Q2
Positive pole is connected, and the colelctor electrode of the second triode Q2 is connected with D.C. contactor.
In use, the output of leakage current sensor is connected on a sampling resistor the present embodiment, and leakage current is believed
Number it is changed into magnitude of voltage；Amplifying circuit is a discharge circuit for dual power supply, leakage current signal can be amplified, due to leakage current
Direction may be for just, it is also possible to be negative, therefore dual power supply amplifier is used, can be carried out amplifying in positive and negative both direction；Electric leakage letter
Number comparison circuit is amplified into, comparison circuit is a window comparator, and using dual power supply, positive threshold is Vth, born
It is-Vth to threshold value, when leakage current is no more than threshold value, comparator is output as height；When leakage current exceedes threshold value, comparator is defeated
Go out for low；The output of comparator enters exclusive circuit, and comparator is output as height when normal, and the output triode of exclusive circuit is in
Opening state, 24V power supplys are connected to D.C. contactor coil, contactor adhesive；When leakage current exceedes threshold value, comparator is reversed to
Low, output the first triode Q1 and the second triode Q2 shut-off of exclusive circuit, the 24V for being connected to D.C. contactor coil are cut
Disconnected, contactor disconnects, even if leakage current recovers normal afterwards, it is height that comparator overturns again, due to the effect of exclusive circuit,
24V power supplys still cannot be connected to D.C. contactor coil, therefore load supplying still cannot recover.Only completely close system electricity
Source, then after restarting, can recover normal.
It is described above to be merely exemplary for the purpose of the present invention, and it is nonrestrictive, and those of ordinary skill in the art understand,
In the case where the spirit and scope that claim is limited are not departed from, any modification, change or the equivalents that can be made are all
To fall within the protection domain of invention.
Claims (4)
1. the DC side earth-fault protection in a kind of DC power-supply system, it is characterised in that：Including D.C. contactor, leakage
Current sensor, sampling resistor, amplifying circuit, comparison circuit and exclusive circuit, described D.C. contactor one end and dc source
Output end is connected, and the other end is connected by the leakage current sensor with load；The output end of the leakage current sensor with adopt
Sample resistance is connected, for leakage current signal to be changed into magnitude of voltage；The output of the amplifying circuit and the leakage current sensor
End is connected, and for leakage current signal to be amplified, and the leakage current signal after amplification is sent into comparison circuit；The comparison circuit
For the leakage current signal after the amplification for receiving the leakage current sensor transmission, and compare with the threshold value of setting, formation is compared
Device is exported, and comparator output is sent into locking circuit；The locking circuit be used to receiving it is described compare output, and lead to
Cross the switch for comparing output control D.C. contactor.
2. the DC side earth-fault protection in a kind of DC power-supply system according to claim 1, its feature exists
In：The amplifying circuit is made up of the first operational amplifier (U1), first resistor (R1) and second resistance (R2)；First fortune
Calculate the positive input ground connection of amplifier (U1) and be connected with described sampling resistor one end, first operational amplifier (U1)
Reverse input end is connected with the sampling resistor other end, and the reverse input end of first operational amplifier (U1) is by described
First resistor (R1) is grounded, the reverse input end of first operational amplifier (U1) by the second resistance (R2) with it is described
The output end of the first operational amplifier (U1) is connected, output end and the comparison circuit phase of first operational amplifier (U1)
Even.
3. the DC side earth-fault protection in a kind of DC power-supply system according to claim 2, its feature exists
In：The comparison circuit is by the second operational amplifier (U2), the 3rd operational amplifier (U3), 3rd resistor (R3) and reference power source
(Vth) constitute；The output end of the positive input of second operational amplifier (U2) and first operational amplifier (U1)
It is connected with the 3rd operational amplifier (U3) reverse input end, the reverse input end of second operational amplifier (U2) and institute
State reference power source (Vth) positive pole to be connected, the output end of second operational amplifier (U2) is connected with the 3rd resistor (R3),
The output end of second operational amplifier (U2) is connected with the exclusive circuit, the forward direction of the 3rd operational amplifier (U3)
Input is connected with the reference power source (Vth) negative pole, the reverse input end of the 3rd operational amplifier (U3) and described
The positive input of two operational amplifiers (U2) is connected with the output end of first operational amplifier (U1), the 3rd computing
The output end of amplifier (U3) is connected with the exclusive circuit.
4. the DC side earth-fault protection in a kind of DC power-supply system according to claim 3, its feature exists
In：The exclusive circuit is by the 4th resistance (R4), the 5th resistance (R5), the 6th resistance (R6), the 7th resistance (R7), the 8th resistance
(R8), the first metal-oxide-semiconductor (MOS1), the second metal-oxide-semiconductor (MOS2), the 3rd metal-oxide-semiconductor (MOS3), the first triode (Q1) and the two or three pole
Pipe (Q2) composition；G grades of first metal-oxide-semiconductor (MOS1) is connected with the comparison circuit output end, first metal-oxide-semiconductor (MOS1)
D grades is connected with by the 4th resistance (R4) with positive source, D grades of first metal-oxide-semiconductor (MOS1) by the 5th resistance (R5) with
G grades of second metal-oxide-semiconductor (MOS2) is connected, S grades of ground connection of first metal-oxide-semiconductor (MOS1), S grades of first metal-oxide-semiconductor (MOS1)
Connect with the 3rd metal-oxide-semiconductor (MOS3) S-phase, S grade of first metal-oxide-semiconductor (MOS1) passes through the 6th resistance (R6) with described the
D grades of two metal-oxide-semiconductors (MOS2) are connected, and S grades of second metal-oxide-semiconductor (MOS2) is connected with positive source, second metal-oxide-semiconductor (MOS2)
G grades be connected with the first triode (Q1) ground level, G grades of second metal-oxide-semiconductor (MOS2) by with the 7th resistance
(R7) it is connected with positive source, D grades of the 3rd metal-oxide-semiconductor (MOS3) is connected with the first triode (Q1) ground level, described
The emitting stage ground connection of the first triode (Q1), the colelctor electrode of first triode (Q1) passes through the 8th resistance (R8) and institute
The ground level for stating the second triode (Q2) is connected, and the emitting stage of second triode (Q2) is connected with positive source, and described second
The colelctor electrode of triode (Q2) is connected with the D.C. contactor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710005148.8A CN106711932A (en) | 2017-01-04 | 2017-01-04 | DC side ground fault protection device in DC power supply system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710005148.8A CN106711932A (en) | 2017-01-04 | 2017-01-04 | DC side ground fault protection device in DC power supply system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN106711932A true CN106711932A (en) | 2017-05-24 |
Family
ID=58903775
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710005148.8A Pending CN106711932A (en) | 2017-01-04 | 2017-01-04 | DC side ground fault protection device in DC power supply system |
Country Status (1)
| Country | Link |
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| CN (1) | CN106711932A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109507515A (en) * | 2017-09-14 | 2019-03-22 | 株洲中车时代电气股份有限公司 | A kind of automation ground detection device and method |
| CN112748275A (en) * | 2020-12-15 | 2021-05-04 | 天津智易时代科技发展有限公司 | Electrostatic purifier monitoring module and monitoring method thereof |
| CN114113755A (en) * | 2020-08-28 | 2022-03-01 | 苏州博思得电气有限公司 | High-voltage generator ignition detection circuit and high-voltage generator |
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| EP0215620A2 (en) * | 1985-09-06 | 1987-03-25 | Southern California Edison Company | DC ground fault detection |
| CN101308185A (en) * | 2008-05-06 | 2008-11-19 | 合肥同智科技发展有限公司 | Direct current supply line electrical leakage detection circuit |
| CN201868837U (en) * | 2010-11-25 | 2011-06-15 | Tcl通力电子（惠州）有限公司 | USB (universal serial bus) circuit |
| CN102761097A (en) * | 2012-07-11 | 2012-10-31 | 合肥华耀电子工业有限公司 | Direct current leakage protective circuit |
| CN103391074A (en) * | 2013-07-12 | 2013-11-13 | 成都启臣微电子有限公司 | Switch power supply self-locking protection circuit |
| CN204392214U (en) * | 2015-02-15 | 2015-06-10 | 杭州华三通信技术有限公司 | A kind of locked circuit |
| CN206517032U (en) * | 2017-01-04 | 2017-09-22 | 山东中大电源科技有限公司 | DC side earth-fault protection in DC power-supply system |
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2017
- 2017-01-04 CN CN201710005148.8A patent/CN106711932A/en active Pending
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0215620A2 (en) * | 1985-09-06 | 1987-03-25 | Southern California Edison Company | DC ground fault detection |
| CN101308185A (en) * | 2008-05-06 | 2008-11-19 | 合肥同智科技发展有限公司 | Direct current supply line electrical leakage detection circuit |
| CN201868837U (en) * | 2010-11-25 | 2011-06-15 | Tcl通力电子（惠州）有限公司 | USB (universal serial bus) circuit |
| CN102761097A (en) * | 2012-07-11 | 2012-10-31 | 合肥华耀电子工业有限公司 | Direct current leakage protective circuit |
| CN103391074A (en) * | 2013-07-12 | 2013-11-13 | 成都启臣微电子有限公司 | Switch power supply self-locking protection circuit |
| CN204392214U (en) * | 2015-02-15 | 2015-06-10 | 杭州华三通信技术有限公司 | A kind of locked circuit |
| CN206517032U (en) * | 2017-01-04 | 2017-09-22 | 山东中大电源科技有限公司 | DC side earth-fault protection in DC power-supply system |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109507515A (en) * | 2017-09-14 | 2019-03-22 | 株洲中车时代电气股份有限公司 | A kind of automation ground detection device and method |
| CN114113755A (en) * | 2020-08-28 | 2022-03-01 | 苏州博思得电气有限公司 | High-voltage generator ignition detection circuit and high-voltage generator |
| CN112748275A (en) * | 2020-12-15 | 2021-05-04 | 天津智易时代科技发展有限公司 | Electrostatic purifier monitoring module and monitoring method thereof |
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Application publication date: 20170524 |
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| WD01 | Invention patent application deemed withdrawn after publication |