CN205509468U - Collection flow box protection device - Google Patents
Collection flow box protection device Download PDFInfo
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- CN205509468U CN205509468U CN201521132948.9U CN201521132948U CN205509468U CN 205509468 U CN205509468 U CN 205509468U CN 201521132948 U CN201521132948 U CN 201521132948U CN 205509468 U CN205509468 U CN 205509468U
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- header box
- voltage
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Abstract
The utility model discloses a collection flow box protection device, the flow box that wherein converges includes photovoltaic cable and circuit breaker to and collection flow box protection device includes acquisition unit, logic unit and execution unit. Acquisition unit is connected with photovoltaic cable electricity to a voltage signal for gathering this photovoltaic cable, thereby logic unit is connected the voltage signal that the receipt was transmitted from acquisition unit with the acquisition unit electricity, then carries out the comparison with this signal of telecommunication and comparative voltage, and logic unit is to execution unit send instruction when the poor absolute value of this voltage signal and comparative voltage is more than or equal to the setting value, and execution unit and logic unit electricity is connected and the command control breaker open operation that transmits according to follow logic unit. The utility model discloses a collection flow box protection device can effective control breaker open operation when photovoltaic cable directly grounded to a series of problems that the solution arouses because of photovoltaic cable ground connection.
Description
Technical field
This utility model relates to field of photovoltaic power generation, is specifically related to a kind of header box protection device.
Background technology
Header box is a kind of to apply the electrical equipment at photovoltaic generating system, and it is responsible for the unidirectional current produced by photovoltaic module, after it once confluxes, is sent to photovoltaic DC-to-AC converter.In order to ensure the reliability of generating, safety, header box is furnished with the protections such as lightning protection, overcurrent and overload.But, the photovoltaic cable being connected with header box and photovoltaic cable break down rate the highest be singlephase earth fault (plus earth or minus earth), this type of fault causes the voltage of healthy phases to raise, and the device within header box is the most breakdown, thus initiation fire.When this type of fault occurs, the equal akinesia of existing protection in header box, the class defect during therefore this is header box design.
Utility model content
The purpose of this utility model is to provide a kind of header box protection device, to solve above-mentioned problems of the prior art.
In order to solve the problems referred to above, this utility model provides a kind of header box protection device, and described header box includes that photovoltaic cable and chopper, described header box protection device include collecting unit, logical block and performance element；Described collecting unit electrically connects with described photovoltaic cable, and is used for gathering the voltage signal of this photovoltaic cable；Described logical block electrically connects with described collecting unit thus receives the voltage signal transmitted from described collecting unit, then being compared with comparing voltage by this voltage signal, when this voltage signal is more than or equal to setting value with the absolute value of the difference comparing voltage, described logical block sends instruction to described performance element；And described performance element electrically connects with described logical block and controls described breaker open operation according to the instruction transmitted from described logical block.
1.25-2 times equal to described setting value of voltage is compared it is preferred that described.
It is preferred that described logical block includes comparator, described comparator electrically connects with described collecting unit and described performance element respectively.
It is preferred that described logical block also includes the first resistance and the second resistance, described first resistance and the second resistance are connected with the positive and negative input of described comparator by wire respectively, and the resistance of described first resistance and described second resistance is equal.
It is preferred that described performance element includes that the first relay, described first relay connect with described logical block and described circuit breaker electric, thus control described breaker open operation according to the instruction transmitted from described logical block.
It is preferred that described performance element also includes that the second relay, described second relay connect with described logical block and described circuit breaker electric, thus control described breaker closing according to the instruction transmitted from described logical block.
It is preferred that described collecting unit is arranged to carry out the voltage gathered from described photovoltaic cable blood pressure lowering process, and send the magnitude of voltage after blood pressure lowering processes to described logical block.
It is preferred that described header box protection device also includes secondary power supply, described secondary power supply electrically connects with described collecting unit, logical block and performance element respectively thus provides electric energy for described collecting unit, logical block and performance element.
It is preferred that the described ratio comparing voltage and the open-circuit voltage of photovoltaic group string branch road is positioned atBetween.
It is preferred that the described voltage that compares is between 380V-400V, and described setting value is between 190V-320V.
It is preferred that the described voltage that compares is equal to 400V, and described setting value is equal to 200V.
To sum up; by header box protection device of the present utility model; breaker open operation can be effectively controlled when photovoltaic cable is directly grounded; thus solve the series of problems caused because of photovoltaic cable ground connection; and header box generation photovoltaic cable through transition resistance eutral grounding fault time; header box protection device of the present utility model can effectively control breaker open operation when endangering bigger, is then failure to actuate when destroying little, prevents from causing because of shutdown economic loss.
Accompanying drawing explanation
Fig. 1 is prior art photovoltaic generating system schematic diagram；
Fig. 2 illustrates the photovoltaic cable ground connection in prior art header box；
Fig. 3 is the schematic diagram of prior art photovoltaic module；
Fig. 4 is each unit connection diagram of the header box protection device according to this utility model one embodiment；
Fig. 5 A-5B illustrates the main circuit figure of logical block of the present utility model；And
Fig. 6 is each unit connection diagram of the header box protection device according to another embodiment of this utility model.
Detailed description of the invention
Below with reference to accompanying drawing, preferred embodiment of the present utility model is described in detail, in order to become apparent from understanding the purpose of this utility model, feature and advantage.It should be understood that embodiment shown in the drawings is not the restriction to this utility model scope, and simply to illustrate that the connotation of technical solutions of the utility model.
Term explanation
Header box: header box Main Function is exactly the input of photovoltaic array to be carried out one-level conflux, is used for reducing photovoltaic array and is linked into the line of inverter, provides lightning protection function, the detection running status of photovoltaic panel, DC quantity state acquisition and circuit-breaker status etc. simultaneously.
Photovoltaic DC-to-AC converter: photovoltaic DC-to-AC converter is to connect resistance capacitance by power electronic devices (MOSFET, IGBT etc.), the break-make of device is controlled in the way of pulse width modulation, the unidirectional current that header box transmission is come is transformed into alternating current, complete the MPPT maximum power point tracking (MPPT) of photovoltaic module, it is ensured that functional control and anti-islanding effect etc. simultaneously.
Chopper: designed coupling or uncoupling means, it is possible to close, break-make and the electric current of carrying normal condition；And can be under abnormal operational conditions, it is also possible to carry out closing, disjunction and the conducting in certain time and break-make.
Photovoltaic generating system, its electrical schematic diagram is shown in 1.From figure 1 it appears that be connected with header box is photovoltaic cable and direct current cables.Photovoltaic cable connection between photovoltaic module group string.Direct current cables is for the connection between header box and photovoltaic DC-to-AC converter.
Fig. 2 is shown in the actual moving process of photovoltaic generating system situation earth fault occur.As in figure 2 it is shown, during photovoltaic plant actual motion, photovoltaic cable certain point occurs that the probability of earth fault is the highest.
When solar irradiation is mapped to the surface of photovoltaic module, it absorbs the photon with certain energy, produces the electron-hole pair being in unbalanced state in the inside of assembly；Under the effect of P-N junction internal electric field, electronics, hole are tended to N, P respectively and are tied, thus are formed about the photoproduction electric field in opposite direction with built in field in P-N junction；Redundance after photoproduction electric field neutralisation P-N junction built in field makes P, N district carry positive and negative point respectively, then produces the photo-induced voltage being pointed to P district by N district, i.e. photovoltaic module voltage in Fig. 1；When then there being electric current to flow out from P district after external load, flowing into photovoltaic cell through load from N district, its schematic diagram is shown in Fig. 3.Owing to P-N junction is the impact of zero reference point, under normal operating conditions, the amplitude of positive and negative electrode voltage is equal, is the half of photovoltaic module voltage.
In Fig. 2, when A point occurs earth fault, the voltage of header box positive pole copper bar side is close to 0.Owing to P-N junction is the reference point there be not ground connection, the voltage that voltage is photovoltaic module of header box negative pole copper bar side.Skyrocketing of negative pole copper bar side voltage, can cause the device within header box the most breakdown, thus initiation fire.But, the protection such as electric current that present stage chopper is furnished with, overload can not action and cut-off breaker.To this end, inventor has invented header box protection device of the present utility model.
As it is shown in figure 1, header box generally includes photovoltaic cable, header box fuse, copper bar and chopper.Wherein, photovoltaic cable is connected with photovoltaic group string, and photovoltaic group string, by being connected with chopper by copper bar after photovoltaic cable parallel connection, arranges header box fuse on photovoltaic cable again.
Header box protection device of the present utility model generally includes collecting unit, logical block and performance element.Collecting unit electrically connects with photovoltaic cable, thus gathers the magnitude of voltage of this photovoltaic cable.Logical block electrically connects with collecting unit, and receive the magnitude of voltage transmitted from collecting unit, then this magnitude of voltage is compared with reference voltage level, when the absolute value of this magnitude of voltage with the difference of reference voltage level is more than or equal to setting value, send instruction to performance element.Performance element controls breaker open operation according to the instruction transmitted from logical block, so that header box will not be damaged because of photovoltaic cable ground connection.
Below in conjunction with the accompanying drawings header box protection device of the present utility model is described in detail.
Embodiment 1
Fig. 4 is the header box protection device each unit connection diagram according to the present embodiment.As shown in Figure 4, header box protection device 100 includes collecting unit 10, logical block 20 and performance element 30.Wherein, collecting unit 10 by wire respectively with positive pole 41 and negative pole 42 electric connection of photovoltaic cable of photovoltaic cable.Logical block 20 is led to collecting unit 10 Electricity Federation by wire.Performance element 30 is led to logical block 20 Electricity Federation by wire.
As shown in Figure 4, the collecting unit 10 of the present embodiment is electrical voltage system measurement apparatus, can be VSM or DC/DC voltage drop element, its positive pole 41 gathering photovoltaic cable and the voltage U of negative pole 42+And U-, and to gathering the voltage U of coming+And U-Carry out blood pressure lowering process, to gathering the voltage U of coming+And U-After carrying out blood pressure lowering process, then will process after magnitude of voltage pass to logical block, hereafter will be described in detail.In the diagram, PE represents that zero reference point, GND represent protective grounding, and secondary power supply 50 is powered for collecting unit 10.
Fig. 5 A, 5B are the main circuit figure of logical block.As shown in Fig. 5 A, 5B, logical block mainly includes comparator 21,22, and wherein, Fig. 5 A illustrates the comparator 21 that the positive pole with photovoltaic cable is connected, and Fig. 5 B illustrates the comparator 22 that the negative pole with photovoltaic cable is connected.
Fig. 5 A illustrates comparator 21, resistance R1、R2And R3, wherein, resistance R1One end be connected with the electrode input end of comparator 21 by wire, resistance R1The other end be wired to collecting unit 10, and receive the voltage U after blood pressure lowering processes from collecting unit 10+。R2One end is connected with the negative input of comparator 21 by wire, the other end passes through wire reception and compares voltage UN.The outfan of comparator 21 electrically connects with performance element 30, thus sends instruction to performance element.
Fig. 5 B and Fig. 5 A is similar, the difference is that only that the electrode input end of comparator 22 is wired to collecting unit 10, and receives the voltage U after blood pressure lowering processes from collecting unit 10-.As shown in Figure 5 B, resistance R4One end be connected with the electrode input end of comparator 22 by wire, resistance R4The other end be wired to collecting unit 10, and receive the voltage U after blood pressure lowering processes from collecting unit 10_。R5One end is connected with the negative input of comparator 22 by wire, the other end passes through wire reception and compares voltage UN, compare voltage UNOpen-circuit voltage according to photovoltaic group string branch road determines.Hereafter will will be described in detail.The outfan of comparator 22 electrically connects with performance element 30, thus sends instruction to performance element 30.
Logical block 20 is used for comparing voltage U+、U-With reference voltage UNSize.Wherein, comparator 21 is used for comparing voltage U+With UNSize, comparator 22 is used for comparing voltage U-With compare voltage UNSize.When meeting expression formula UN-U+>=ε or UN-U-During >=ε (ε is setting value), it is possible to determine that photovoltaic cable ground connection, certainly, also include the situation of direct current cables ground connection.
Performance element 30 mainly includes relay J 1, relay J 1 and logical block 20 and chopper 60 electric connection, and when logical block 20 sends separating brake instruction to relay J 1, relay J 1 controls switch 31 closedown, thus controls chopper 60 separating brake.
The photovoltaic cable ground connection of header box or direct current cables ground connection include being directly grounded and through transition resistance eutral grounding, it is directly grounded and refers to photovoltaic cable and be directly connected on the ground, photovoltaic cable is referred to by a resistance ground connection again through transition resistance eutral grounding, therefore, the voltage of this photovoltaic cable collected when photovoltaic cable is directly grounded is 0, and the value of the voltage that photovoltaic cable collects when transition resistance eutral grounding additionally depends on the size of this resistance by resistance eutral grounding.
But, find through substantial amounts of engineering practice inventor, in the case of transition resistance eutral grounding, if this is sufficiently large through the resistance of transition resistance eutral grounding, then the danger caused is minimum, and therefore, this utility model is according to the practical situation of engineering practice, by UNIt is equal to the 17/41-20/41 that photovoltaic group passes the open-circuit voltage of branch road, ε is equal to 0.4UN-0.8UN, good effect can be obtained.Such as, when the open-circuit voltage of photovoltaic group string branch road is equal to 820V, UNEqual to 380V-400V, ε equal to 0.4UN-0.8UN.It is preferred that when the open-circuit voltage of photovoltaic group string branch road is equal to 820V, by UNIt is set to 400V, ε is set to 200V.
In header box work process, if it occur that the directly grounded situation of photovoltaic cable, owing to photovoltaic cable is directly grounded, the voltage of earth point is 0, therefore, and the U collected by collecting unit+Or U-Equal to 0, now, logical block judges UN-U+>=ε or UN-U->=ε, thus, logical block sends separating brake instruction to performance element, after logical block receives separating brake instruction, controls switch 31 Guan Bi by relay J 1, thus controls breaker open operation.Therefore avoid header box and cause serious consequence because of ground connection.
If it occur that the photovoltaic cable situation through transition resistance eutral grounding, now, if UN-U+>=ε or UN-U->=ε, then logical block sends separating brake instruction to performance element, after logical block receives separating brake instruction, controls switch 31 Guan Bi by relay J 1, thus controls the breaker open operation of header box, thus avoid header box and cause serious consequence because of ground connection.And if being unsatisfactory for UN-U+>=ε or UN-U->=ε, then can process, because this kind of situation can't cause big destruction, thus reduces the loss caused because of shutdown to greatest extent.
Embodiment 2
Fig. 6 is each unit connection diagram of the header box protection device according to the present embodiment.The header box protection device 200 of the present embodiment is described referring to Fig. 6.Embodiment 2 essentially consists in the difference of embodiment 1, performance element 30 also includes relay J 2, and relay J 2 is by wire and logical block electric connection, thus receives the reclosing command that logical block sends, when receiving the reclosing command that logical block sends, control breaker closing.
During header box works, if it occur that photovoltaic cable ground connection, thus chopper is when being disconnected under the control of performance element, after people finder goes out earth fault and solves a problem with grounding at the scene, in embodiment 1 can be by artificial by breaker closing, sending reclosing command by logical block to relay J 2 in example 2, relay J 2 controls switch 32 closedown after receiving reclosing command, thus controls breaker closing.
To sum up; by header box protection device of the present utility model; breaker open operation can be effectively controlled when photovoltaic cable is directly grounded; thus solve the series of problems caused because of photovoltaic cable ground connection; and header box generation photovoltaic cable through transition resistance eutral grounding fault time; header box protection device of the present utility model can effectively control breaker open operation when endangering bigger, is then failure to actuate when endangering little, prevents from causing because of shutdown economic loss.
Below preferred embodiment of the present utility model has been described in detail, it is understood that after having read above-mentioned teachings of the present utility model, this utility model can be made various changes or modifications by those skilled in the art.These equivalent form of values fall within the application appended claims limited range equally.
Claims (10)
1. a header box protection device, described header box includes photovoltaic cable and chopper, it is characterised in that described header box protection device includes collecting unit, logical block and performance element；Described collecting unit electrically connects with described photovoltaic cable, and is used for gathering the voltage signal of this photovoltaic cable；Described logical block electrically connects with described collecting unit thus receives the voltage signal transmitted from described collecting unit, then being compared with comparing voltage by this voltage signal, when this voltage signal is more than or equal to setting value with the absolute value of the difference comparing voltage, described logical block sends instruction to described performance element；And described performance element electrically connects with described logical block and controls described breaker open operation according to the instruction transmitted from described logical block.
Header box protection device the most according to claim 1, it is characterised in that the described voltage that compares is equal to 1.25-2 times of described setting value.
Header box protection device the most according to claim 1, it is characterised in that described logical block includes comparator, described comparator electrically connects with described collecting unit and described performance element respectively.
Header box protection device the most according to claim 3; it is characterized in that; described logical block also includes the first resistance and the second resistance; described first resistance and the second resistance are connected with the positive and negative input of described comparator by wire respectively, and the resistance of described first resistance and described second resistance is equal.
Header box protection device the most according to claim 1; it is characterized in that; described performance element includes that the first relay, described first relay connect with described logical block and described circuit breaker electric, and controls described breaker open operation according to the instruction transmitted from described logical block.
Header box protection device the most according to claim 5; it is characterized in that; described performance element also includes that the second relay, described second relay connect with described logical block and described circuit breaker electric, thus controls described breaker closing according to the instruction transmitted from described logical block.
Header box protection device the most according to claim 1, it is characterised in that described collecting unit is arranged to carry out the voltage gathered from described photovoltaic cable blood pressure lowering process, and sends the magnitude of voltage after blood pressure lowering processes to described logical block.
Header box protection device the most according to claim 1; it is characterized in that; described header box protection device also includes secondary power supply, and described secondary power supply electrically connects with described collecting unit, logical block and performance element respectively thus provides electric energy for described collecting unit, logical block and performance element.
Header box protection device the most according to claim 1, it is characterised in that the described ratio comparing voltage and the open-circuit voltage of photovoltaic group string branch road is positioned atBetween.
Header box protection device the most according to claim 1, it is characterised in that the described voltage that compares is between 380V-400V, and described setting value is between 190V-320V.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201521132948.9U CN205509468U (en) | 2015-12-30 | 2015-12-30 | Collection flow box protection device |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201521132948.9U CN205509468U (en) | 2015-12-30 | 2015-12-30 | Collection flow box protection device |
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| CN205509468U true CN205509468U (en) | 2016-08-24 |
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| CN201521132948.9U Active CN205509468U (en) | 2015-12-30 | 2015-12-30 | Collection flow box protection device |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106532637A (en) * | 2016-11-30 | 2017-03-22 | 中国电力工程顾问集团华东电力设计院有限公司 | Protection apparatus and method for combiner box |
| CN106655086A (en) * | 2016-11-30 | 2017-05-10 | 中国电力工程顾问集团华东电力设计院有限公司 | Combiner box protection device and method |
| CN106655087A (en) * | 2016-11-30 | 2017-05-10 | 中国电力工程顾问集团华东电力设计院有限公司 | Combiner box protection device and method |
| CN106684816A (en) * | 2016-11-30 | 2017-05-17 | 中国电力工程顾问集团华东电力设计院有限公司 | Combiner box protection device and method |
| CN106936112A (en) * | 2015-12-30 | 2017-07-07 | 中国电力工程顾问集团华东电力设计院有限公司 | Header box protection device |
-
2015
- 2015-12-30 CN CN201521132948.9U patent/CN205509468U/en active Active
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106936112A (en) * | 2015-12-30 | 2017-07-07 | 中国电力工程顾问集团华东电力设计院有限公司 | Header box protection device |
| CN106936112B (en) * | 2015-12-30 | 2019-09-06 | 中国电力工程顾问集团华东电力设计院有限公司 | Header box protective device |
| CN106532637A (en) * | 2016-11-30 | 2017-03-22 | 中国电力工程顾问集团华东电力设计院有限公司 | Protection apparatus and method for combiner box |
| CN106655086A (en) * | 2016-11-30 | 2017-05-10 | 中国电力工程顾问集团华东电力设计院有限公司 | Combiner box protection device and method |
| CN106655087A (en) * | 2016-11-30 | 2017-05-10 | 中国电力工程顾问集团华东电力设计院有限公司 | Combiner box protection device and method |
| CN106684816A (en) * | 2016-11-30 | 2017-05-17 | 中国电力工程顾问集团华东电力设计院有限公司 | Combiner box protection device and method |
| CN106655086B (en) * | 2016-11-30 | 2018-09-14 | 中国电力工程顾问集团华东电力设计院有限公司 | A kind of header box protective device and method |
| CN106532637B (en) * | 2016-11-30 | 2018-09-14 | 中国电力工程顾问集团华东电力设计院有限公司 | A kind of header box protective device and method |
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