CN203025297U - Return contact-free fuse blow detection circuit - Google Patents
Return contact-free fuse blow detection circuit Download PDFInfo
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- CN203025297U CN203025297U CN 201220729707 CN201220729707U CN203025297U CN 203025297 U CN203025297 U CN 203025297U CN 201220729707 CN201220729707 CN 201220729707 CN 201220729707 U CN201220729707 U CN 201220729707U CN 203025297 U CN203025297 U CN 203025297U
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Abstract
The utility model relates to a fuse blow detection circuit in a three-phase power device, belonging to the field of power equipment. The utility model provides a return contact-free fuse blow detection circuit, a fuse is arranged on a three-phase incoming line of the device, the return contact-free fuse blow detection circuit is characterized in that voltage detection loops are arranged two ends of the fuse, the voltage detection loops linearly converts an alternating current-phase voltage into an input level of a voltage processing module successively connected through detecting the voltage, entering the device, at a lower port of the fuse, the voltage processing module comprises a voltage asymmetrical component detection circuit which is used for calculating the amplitude of the symmetrical component in a voltage signal of the input level as an input of a comparison output circuit successively connected, the comparison output circuit compares the voltage output by the voltage processing module with a reference voltage, and outputs a fuse fault signal to a central processor when the amplitude of the symmetrical component in the voltage exceeds the reference voltage. According to the return contact-free fuse blow detection circuit, the circuit connection is convenient, and the volume of the fuse is saved.
Description
Technical field
The utility model relates to the fuse blows testing circuit in a kind of three-phase power device, relates in particular to without the fuse blows testing circuit that returns to the contact.
Background technology
Band returns to fuse widespread use in low voltage electrical equipment of contact, can timely fault-signal be returned to the center processor of control during fuse blows, realizes the protection operation.But the use of returning to the contact makes fuse structure become complicated, and volume is difficult to do little, and price is corresponding increase also.Particularly weld fuse in printed board, the original contact of just not returning.
Summary of the invention
Technical problem to be solved in the utility model is to provide a kind of nothing and returns to contact fuse blows testing circuit, solves when nothing is returned to the contact fuse blows, can accurately check out the problem whether fuse fuses.
Technical scheme
a kind of nothing is returned to contact fuse blows testing circuit, described fuse is arranged on the three-phase inlet wire of device, it is characterized in that: be provided with the voltage detecting loop at fuse two ends, described voltage detecting loop is by the voltage of the access to plant of detection fuse end opening, the ac phase voltage linear transformation at this place is become the incoming level of the voltage processing module of follow-up connection, described voltage processing module comprises an asymmetrical voltage component detection circuit, calculate the amplitude of asymmetrical component in the voltage signal of described incoming level, input as the comparison output circuit of follow-up connection, described relatively output circuit is made comparisons voltage and the reference voltage of described voltage processing module output, when asymmetrical component amplitude in voltage surpasses reference voltage, the fuse output fault-signal is to center processor.
Described voltage detecting loop comprises the first resistance, the second resistance, the 3rd resistance, the 4th resistance, the 5th resistance, the 6th resistance, a PT, the 2nd PT, the 3rd PT; The first resistance, the second resistance, the 3rd resistance one end are connected to the suitable for reading of the three-phase fuse that need to detect, and the other end is joined together to form a stable dummy neutral N; The 4th resistance, the 5th resistance, the 6th resistance one end are connected respectively to the end opening of the three-phase fuse that needs detection, and the other end is connected respectively to a PT, the 2nd PT, the 3rd former limit of PT input end of the same name; The one PT, the 2nd PT, the 3rd PT former limit other end are received dummy neutral N; Secondary termination of the same name is together as the output in described voltage detecting loop, another termination power of secondary ground.
Described the first resistance, the second resistance, the 3rd resistance are made of electric capacity.
Described the first resistance, the second resistance, the 3rd resistance are less than the 4th resistance, the 5th resistance, the 6th resistance; Described the 4th resistance, the 5th resistance, the 6th resistance equate.
Described voltage processing module comprises relatively amplifying circuit and an absolute value circuit; The in-phase input end connection power supply ground that compares amplifying circuit, relatively the inverting input of amplifying circuit is connected to the output in described voltage detecting loop, relatively the output of amplifying circuit is connected to the inverting input of absolute value circuit through resistance, and the output of absolute value circuit is as the input of the comparison output loop of described follow-up connection.
Described relatively output circuit comprises a comparator circuit and an optocoupler, the in-phase input end of comparator circuit connects the reference voltage of setting, the output of the described voltage processing module of anti-phase input termination, the output of comparator circuit connects the input of optocoupler, optocoupler fuse output status signal level.
Beneficial effect
Nothing of the present utility model is returned to contact fuse blows testing circuit and is judged without the state that returns to the contact fuse based on the asymmetrical voltage component detection, when fuse blows, can accurately check out whether fuse fuses, and the fuse state signal be returned to the center processor of control; The utility model has solved the technical matters of returning without the blown state of returning to the contact fuse, and circuit is uncomplicated, and is easy to connect, saved the volume of fuse.
Description of drawings
Fig. 1 is course of work schematic diagram of the present utility model.
Fig. 2 is circuit diagram of the present utility model.
Wherein: 1-voltage detecting loop, 2-voltage processing module, 3-is output circuit relatively.
Embodiment
Below in conjunction with specific embodiments and the drawings, further set forth the utility model.
The nothing that the utility model proposes is returned to contact fuse blows testing circuit and is comprised voltage detecting loop, voltage processing module and comparison output loop.The voltage detecting loop by detecting fuse end opening (device side) voltage, is voltage processing module incoming level with voltage transitions, and in three-phase voltage, the asymmetrical component amplitude has judged whether fuse blows to the voltage processing module by detecting.Accompanying drawing 1 is whole circuit working process schematic diagram.
Concrete implementing circuit as shown in Figure 2.The present embodiment obtains a stable dummy neutral N by three-phase fuse star connecting resistance suitable for reading (R1, R2, R3 also can use electric capacity).The PT sampling is connected on the fuse end opening, detects the voltage signal of fuse end opening, realizes simultaneously a secondary isolation.By use isolate PT can the filtering three-phase voltage in zero-sequence component, remove the impact of residual voltage on detecting.
The voltage signal that detects is that low-voltage simulating signal as to voltage processing module 2 input by resistance R 4, R5, R6, R7, PT1, PT2, PT3 with the high tension voltage linear transformation by voltage detecting loop 1; Voltage processing module 2 calculates asymmetrical component voltage magnitude Uo in three-phase voltage signal by U1A, offers comparison output circuit 3 as input.
R1, R2 in figure, R3 resistance value ratio R4, R5, R6 are little, thereby provide a stable dummy neutral N(also can substitute R1, R2, R3 by three electric capacity).Voltage transformer pt 1, PT2, PT3 can regard the CT as 1:1 as, with the undistorted secondary that is passed to of primary current.When fuse fuses mutually, guarantee that sampling circuit N is not offset.R4, R5, three resistance of R6 equate, the satisfied following formula of amplifier U1A output Uo.
Uo is asymmetrical voltage component in the three-phase sampled voltage.In circuit, the U1B effect is to take absolute value, and R8, R9 resistance equate, the U1B output voltage is-Uo.When negative, U1B just is output as, D2 conducting, D1 cut-off as Uo; When Uo is timing, U1B is output as negative, D1 conducting, D2 cut-off; So Uo by after taking absolute value, is added in comparer U2A input terminal voltage and just is.With reference data magnitude of voltage Vref device U2A input as a comparison, compare after the Uo process takes absolute value, comparer output drives an optocoupler O1, and comparative result is exported.
Uo inputs as absolute value circuit, and absolute value circuit is exported device inverting input input as a comparison, Vref device in-phase input end input as a comparison.When the asymmetrical component absolute value of voltage surpasses reference data voltage Vref, judge the fuse fault, the comparator circuit level will become low level by high level; Due to the comparer output low level, the optocoupler input is low by hypermutation, and the optical coupling secondary edges node disconnects.
Described reference data voltage is a magnitude of voltage that arranges in advance, the asymmetrical component value that exists in line voltage is considered in choosing with reference to GB of this value, calculate through voltage processing module 2 output voltage values corresponding behind voltage detecting loop 1, and then stop enough surpluses.Because in electrical network, the asymmetrical voltage component value is very little, and the asymmetrical component value of voltage is very large when the single-phase or two-phase fusing of fuse occurs, so can stay larger surplus, prevents 3 misoperations of comparison output circuit.
When fuse was all normal, the three-phase voltage sum was about 0V, and lower than reference voltage Vref, comparer U2A exports high level, and optocoupler O1 is input as high level, the conducting of optocoupler output node.
When single-phase or two-phase fusing, Ua, Ub, Uc sum are phase voltage value.Therefore Uo absolute value peak value will be higher than reference voltage Vref, the low pulse of comparer U2A output, and optocoupler O1 is input as low level, and the optocoupler output node disconnects.
Claims (6)
1. a nothing is returned to contact fuse blows testing circuit, described fuse is arranged on the three-phase inlet wire of device, it is characterized in that: be provided with the voltage detecting loop at fuse two ends, described voltage detecting loop is by the voltage of the access to plant of detection fuse end opening, the ac phase voltage linear transformation at this place is become the incoming level of the voltage processing module of follow-up connection, described voltage processing module comprises an asymmetrical voltage component detection circuit, calculate the amplitude of asymmetrical component in the voltage signal of described incoming level, input as the comparison output circuit of follow-up connection, described relatively output circuit is made comparisons voltage and the reference voltage of described voltage processing module output, when asymmetrical component amplitude in voltage surpasses reference voltage, the fuse output fault-signal is to center processor.
2. nothing as claimed in claim 1 is returned to contact fuse blows testing circuit, it is characterized in that: described voltage detecting loop comprises the first resistance, the second resistance, the 3rd resistance, the 4th resistance, the 5th resistance, the 6th resistance, a PT, the 2nd PT, the 3rd PT; The first resistance, the second resistance, the 3rd resistance one end are connected to the suitable for reading of the three-phase fuse that need to detect, and the other end is joined together to form a stable dummy neutral N; The 4th resistance, the 5th resistance, the 6th resistance one end are connected respectively to the end opening of the three-phase fuse that needs detection, and the other end is connected respectively to a PT, the 2nd PT, the 3rd former limit of PT input end of the same name; The one PT, the 2nd PT, the 3rd PT former limit other end are received dummy neutral N; Secondary termination of the same name is together as the output in described voltage detecting loop, another termination power of secondary ground.
3. nothing as claimed in claim 2 is returned to contact fuse blows testing circuit, it is characterized in that: described the first resistance, the second resistance, the 3rd resistance are made of electric capacity.
4. nothing as claimed in claim 2 is returned to contact fuse blows testing circuit, it is characterized in that: described the first resistance, the second resistance, the 3rd resistance are less than the 4th resistance, the 5th resistance, the 6th resistance; Described the 4th resistance, the 5th resistance, the 6th resistance equate.
5. nothing as claimed in claim 1 or 2 is returned to contact fuse blows testing circuit, it is characterized in that: described voltage processing module comprises relatively amplifying circuit and an absolute value circuit; The in-phase input end connection power supply ground that compares amplifying circuit, relatively the inverting input of amplifying circuit is connected to the output in described voltage detecting loop, relatively the output of amplifying circuit is connected to the inverting input of absolute value circuit through resistance, and the output of absolute value circuit is as the input of the comparison output loop of described follow-up connection.
6. nothing as claimed in claim 1 or 2 is returned to contact fuse blows testing circuit, it is characterized in that: described relatively output circuit comprises a comparator circuit and an optocoupler, the in-phase input end of comparator circuit connects the reference voltage of setting, the output of the described voltage processing module of anti-phase input termination, the output of comparator circuit connects the input of optocoupler, optocoupler fuse output status signal level.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201220729707 CN203025297U (en) | 2012-12-26 | 2012-12-26 | Return contact-free fuse blow detection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201220729707 CN203025297U (en) | 2012-12-26 | 2012-12-26 | Return contact-free fuse blow detection circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN203025297U true CN203025297U (en) | 2013-06-26 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201220729707 Expired - Fee Related CN203025297U (en) | 2012-12-26 | 2012-12-26 | Return contact-free fuse blow detection circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN203025297U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112332402A (en) * | 2020-09-18 | 2021-02-05 | 北京潞电电气设备有限公司 | Dual-power measurement and control device |
| CN112467721A (en) * | 2020-09-18 | 2021-03-09 | 北京潞电电气设备有限公司 | Three-power-supply power supply system control device |
-
2012
- 2012-12-26 CN CN 201220729707 patent/CN203025297U/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112332402A (en) * | 2020-09-18 | 2021-02-05 | 北京潞电电气设备有限公司 | Dual-power measurement and control device |
| CN112467721A (en) * | 2020-09-18 | 2021-03-09 | 北京潞电电气设备有限公司 | Three-power-supply power supply system control device |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20130626 Termination date: 20211226 |