CN206349742U - A kind of header box protection device - Google Patents
A kind of header box protection device Download PDFInfo
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- CN206349742U CN206349742U CN201621307938.9U CN201621307938U CN206349742U CN 206349742 U CN206349742 U CN 206349742U CN 201621307938 U CN201621307938 U CN 201621307938U CN 206349742 U CN206349742 U CN 206349742U
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Abstract
The utility model is related to a kind of header box protection device, and the header box includes photovoltaic cable, direct current cables and breaker, and the header box protection device includes collecting unit, logic unit and execution unit；Voltage signal on the voltage signal and photovoltaic cable branch road of the collecting unit collection direct current cables；Described logic unit includes comparison module in parallel, comparison module is electrically connected with the collecting unit, comparison module includes multiplication comparator component, multiplication comparator component access voltage signal and comparison voltage, the output end access adder components of multiplication comparator component.The beneficial effects of the utility model are to carry out the monitoring of short trouble to photovoltaic cable and direct current cables simultaneously, when short trouble occurs for any of which, can effectively recognize and send trip command respectively, so as to realize failure removal, multiple protective is formd to cable.
Description
Technical field
The utility model is related to field of photovoltaic power generation, and in particular to a kind of header box protection device.
Background technology
Header box is a kind of electrical equipment applied in photovoltaic generating system, and it is responsible for the direct current for producing photovoltaic module
Electricity, after it once confluxes, is sent to photovoltaic DC-to-AC converter.In order to ensure the reliability, the security that generate electricity, header box is equipped with anti-
Thunder, overcurrent and overload etc. are protected.But, the photovoltaic cable failure rate highest being connected with header box is monopole ground connection
Failure (plus earth or negative pole ground connection), such failure triggers the device inside the voltage rise of non-faulting pole, header box in height
It is breakdown in the case of pressure, so as to trigger fire.Because the current detection accuracy of traditional header box is only 3%~5%, it is impossible to essence
Really a group string branch road is detected, and the size of electric current is larger by ambient lighting and ambient temperature effect ratio.Therefore this is header box
A class defect in design.
The present inventor once applied for patent document, Application No. " CN201521132948.9 ", Patent No. on this question
" CN205509468U ", the utility model of entitled header box protection device.The utility model proposes collecting unit, logic unit
And the structure of execution unit, logic unit electrically connects with collecting unit so as to receiving the voltage signal transmitted from collecting unit, so
The electric signal and comparison voltage are compared afterwards, set when the voltage signal and the poor absolute value of comparison voltage are more than or equal to
Logic unit sends to execution unit and instructed during definite value；And execution unit is electrically connected with logic unit and according to from logic unit
The instruction control breaker open operation transmitted.The invention solves the problems, such as short-circuit detection protection.But, what original patent was referred to confluxes
Case is that dc circuit breaker on/off switch function is realized by Control contactor break-make.Its mechanical action is frequent, failure
Rate is high, and service life is short.During photovoltaic application, header box generally enters 1 and 10 using 16 and enters 1 two kinds of forms.Converged due to every
Stream case concatenates the photovoltaic module of 16 or 10 branch roads respectively, therefore, and header box protection has multiple branch circuit while the requirement detected.Tradition is converged
The photovoltaic branch road of stream case, equivalent to DC node is added, due to the influence of day and night temperature, accelerates the hot tired of fuse using fuse
Labor effect, when fuse node loose contact, its fusing time is elongated., can failure line in the case of this " not breaking disconnected "
The insulation of cable and fuse block, finally triggers firing accident.Header box internal-flange bolt loosens, similar with its situation.
When earth fault occurs for direct current cables, the electric current flowed through on normal cable can be by photovoltaic DC-to-AC converter DC cabinet
Bus goes out conflux after " anti-fill " arrive failure cable.The breaker for connecting photovoltaic DC-to-AC converter on failure cable is jumped because electric current is excessive
Lock.But, the electric current of breaker does not increase in header box, now, and header box equipment appearance ground connection pole tension is low, ungrounded
Pole tension is raised.This is a kind of hidden danger that photovoltaic generating system exists in itself, and should give consideration can take measures to be controlled by.
In view of above-mentioned defect, the positive research and innovation of the present inventor, propose a kind of header box protection dress for being adapted to photovoltaic generating system
Put, effectively can prevent failure from further expanding.
Utility model content
The purpose of this utility model is to provide a kind of header box protection device for being capable of multi-thread, many point protections, effectively investigate,
The various circuit problems that detection, control header box are likely to occur.
In order to achieve the above object there is provided a kind of header box protection device, the header box includes photovoltaic cable, direct current
Cable and breaker, the header box protection device include collecting unit, logic unit and execution unit；With
Voltage signal on the voltage signal and at least one photovoltaic cable branch road of the collecting unit collection direct current cables；
With
Described logic unit includes at least two comparison modules in parallel, and comparison module is electrically connected with the collecting unit
Connect, one of comparison module receives the voltage signal on the direct current cables, other comparison modules receive the photovoltaic cable
The voltage signal of branch road, comparison module includes multiplication comparator component, multiplication comparator component access voltage signal and ratio
Compared with voltage, the output end of each multiplication comparator component is linked into the input of addition comparator component, addition comparator component
Output end accesses execution unit, and the voltage signal and the absolute value of comparison voltage difference of any comparison module are more than or equal to setting value
When to the execution unit send circuit breaker trip instruction；With
The execution unit is electrically connected with the logic unit and according to the instruction control that the logic unit is transmitted
Breaker open operation.
Described multiplication comparator component is made up of two multipliers and comparator in parallel, and a described multiplier connects
Enter voltage signal, another multiplier access comparison voltage, the output end of two multipliers and the input of comparator are connected.
Addition comparator includes adder and zero-crossing comparator is constituted.
To being improved for logic unit in the utility model, main contrast carries out parallel connection compared with module, i.e., module is defeated
Enter the voltage that end is respectively connected to collection, but output end is collaborated.Collecting unit gathers multiple magnitudes of voltage, and this magnitude of voltage includes direct current
Voltage letter on the voltage signal on voltage signal and photovoltaic cable on cable, one of comparison module access direct current cables
Number, the voltage signal on remaining comparison module access photovoltaic cable carries out logic judgment, when the voltage signal of any comparison module
When being more than or equal to setting value with the poor absolute value of comparison voltage, illustrate that short trouble occurs for cable, sent to execution unit
Instruction is so as to control breaker.
, it can be said that at least one is used for the comparison module and a ratio monitored for photovoltaic cable that direct current cables is monitored
Can essentially be multiple comparison modules monitored for photovoltaic cable, its type of attachment is still in the utility model compared with module
It is so in parallel, is so the monitoring that multi-route can be achieved.
It is preferred that, in addition to guide wire；The collecting unit also gathers the voltage signal of photovoltaic DC-to-AC converter side；With it is described
Logic unit also includes direct current cables Fault Identification module, and direct current cables identification module is in parallel with comparison module, the direct current
Cable Fault Identification module receives the voltage signal of photovoltaic DC-to-AC converter side, voltage signal and comparison voltage on direct current cables, and photovoltaic is inverse
When the poor absolute value for becoming voltage signal on the voltage signal and direct current cables of device side is more than the threshold value of comparison voltage, output is confluxed
Case trip signal, header box trip signal is sent to photovoltaic DC-to-AC converter by guide wire, and the direct current of control photovoltaic DC-to-AC converter side breaks
Road device tripping operation.
Because voltage difference absolute value is more than or equal to the situation of setting value in the presence of two kinds of possibility, i.e. direct current on direct current cables
Cable fault and photovoltaic DC-to-AC converter DC side failure, in order to recognize failure, the utility model is additionally arranged direct current cables Fault Identification
Module, takes the voltage signal of photovoltaic DC-to-AC converter side, the signal on direct current cables to make the difference and be compared with comparison voltage, so as to judge
Whether it is direct current cables failure.When belonging to direct current cables failure, header box trip signal is exported, header box trip signal passes through
Guide wire is sent to photovoltaic DC-to-AC converter, the dc circuit breaker tripping operation of control photovoltaic DC-to-AC converter side.
It is preferred that, the logic unit also includes triode T3, receive direct current cables voltage signal comparison module in
The output end of multiplication comparator accesses the triode T3Colelctor electrode, the direct current cables Fault Identification module output termination
Enter the triode T3Base stage, the triode T3Emitter stage be connected with guide wire, and triode T3Emitter stage accesses addition
In comparator, when threshold value of the difference more than comparator voltage of voltage signal on the voltage signal and direct current cables of photovoltaic DC-to-AC converter,
And receive the comparison module of direct current cables voltage signal and comparison voltage difference absolute value more than or equal to setting value when to holding
Row unit sends instruction.
Further, the logic unit also includes triode T2, three poles described in the signal that comparison module in parallel is exported
Pipe T2Colelctor electrode, triode T3Emitter stage access triode T2Base stage, the triode T2Emitter stage connection guiding
Line.
It is preferred that, described guide wire is RS485 guide wires.
It is preferred that, described direct current cables Fault Identification module includes operational amplifier and comparator, the operation amplifier
Voltage signal on the voltage signal and direct current cables of device access photovoltaic DC-to-AC converter side, the input of comparator is respectively connected to computing
The output end and comparison voltage of amplifier.
Further, described direct current cables Fault Identification module includes positive DC cable identification module in parallel and born
On pole direct current cables identification module, described positive DC cable identification module access photovoltaic DC-to-AC converter side and direct current cables just
Comparator output terminal access diode in voltage, positive DC cable identification module；Recognized with described negative DC cable
The negative voltage that module is accessed on photovoltaic DC-to-AC converter side and direct current cables, the comparator output terminal of negative DC cable identification module connects
Enter voltage signal on the voltage signal and direct current cables of photovoltaic DC-to-AC converter side in diode, any identification module difference be more than than
Compared with voltage threshold value when, export header box trip signal.
It is preferred that, the logic unit also includes fuse identification module, and fuse identification module is in parallel with comparison module, described
Fuse identification module receives voltage signal, the voltage signal of photovoltaic cable and the comparison voltage of direct current cables, when direct current cables
The difference of the voltage signal of voltage signal and photovoltaic cable is more than comparison voltage, sends and instructs to the execution unit.
Fuse identification module is but also as bolt looseness identification module.
It is preferred that, described fuse identification module includes operational amplifier, comparator and diode, the operational amplifier
The voltage signal of photovoltaic DC-to-AC converter and the voltage signal of direct current cables are respectively connected to, the comparator is respectively connected to operational amplifier
Output end and comparison voltage.
Further, described fuse identification module includes positive pole fuse identification module and negative pole fuse identification mould in parallel
Block, described positive pole fuse identification module access photovoltaic cable and the positive voltage of direct current cables, described negative pole fuse identification mould
Block accesses the negative voltage of photovoltaic cable and direct current cables, the voltage cable signal of the direct current of any identification module and photovoltaic cable
Difference is more than comparison voltage, sends and instructs to the execution unit.
It is preferred that, the electricity on the voltage signal and at least two photovoltaic cable branch roads of the collecting unit collection direct current cables
Press signal；With
Described logic unit includes at least three comparison modules in parallel, and one of comparison module receives the direct current
Voltage signal on cable, separately has at least two comparison modules to receive the voltage signal of the photovoltaic cable branch road, receives optical cable
Each comparison module of branch voltage signal receives the voltage signal on respectively different photovoltaic cable branch road.
Further, the logic unit also includes fuse identification module, and the fuse identification module receives direct current cables
Voltage signal, comparison voltage and collecting unit collection at least two photovoltaic cables voltage signal, multiple photovoltaic cables
Operational amplifier and comparator are accessed after voltage signal series diode, when the voltage signal and the electricity of photovoltaic cable of direct current cables
Press the difference of signal to be more than comparison voltage, send and instruct to the execution unit.
Further, described logic unit also includes protection module, and the output signal access of comparison module in parallel is protected
Module connection is protected, protection module outputs signal to execution unit.
It is preferred that, described execution unit, which includes gate pole, can cut-off IGCT.
It is preferred that, described collecting unit includes bleeder circuit, wave filter, voltage follower, the photoelectricity coupling being sequentially connected
Clutch and voltage-stabiliser tube.
The utility model discloses a kind of scheme for most having a choosing, a kind of header box protection device, the header box includes light
Luff cable, direct current cables and breaker, the header box protection device include collecting unit, logic unit and execution unit；
With
The voltage signal of collecting unit collection direct current cables and the voltage signal at least one photovoltaic cable branch road,
Photovoltaic is against electrical equipment side voltage signal；With
Described logic unit include at least two comparison modules, direct current cables Fault Identification module, fuse identification module,
One of comparison module receives the voltage signal on the direct current cables, and other comparison modules receive the photovoltaic cable branch road
Voltage signal, the direct current cables Fault Identification module receives voltage signal on direct current cables and photovoltaic DC-to-AC converter side
Voltage signal, the fuse identification module receives the voltage signal on direct current cables and the voltage signal on photovoltaic cable, directly
The difference of voltage signal in stream cable fault identification module on the voltage signal and direct current cables of direct current photovoltaic inverter side is more than
The threshold value of comparator voltage, and receive in the comparison module of direct current cables, the poor absolute value of voltage signal and comparison voltage is big
When setting value, voltage signal and the poor absolute value of comparison voltage in high level signal, remaining comparator are exported big
In or equal to setting value, the voltage signal of direct current cables in high level signal, fuse identification module is exported more than photovoltaic cable electricity
When pressing signal, high level signal is exported；Thrin will be sent to execution unit and send instruction when being high level signal, described
Signed magnitude arithmetic(al) uses multiplication comparator component；With
The execution unit is electrically connected with the logic unit and according to the instruction control that the logic unit is transmitted
Breaker open operation.
A kind of header box guard method, comprises the following steps：
With collecting unit collection direct current cables voltage signal Uz, at least one photovoltaic cable voltage signal Ui, photovoltaic inversion side
Voltage signal Um；
Logic unit receive collecting unit collection to voltage signal Uz、Ui、UmAnd comparison voltage Uε1、 Uε2、Uε3Carry out
Logical operation：
When meet ((| UZ+-UZ-|>Uε1)and(Um-Uz>Uε3))or(|Ui+-Ui-|>Uε1)or (Ui-Uz＞ Uε2) when to holding
Row unit, which is sent, performs signal；
The instruction that execution unit is transmitted according to the logic unit controls the breaker open operation.
Wherein, | UZ+-UZ-|>Uε1Computing and | Ui+-Ui-|>Uε1Computing using multiplication comparator component perform, or fortune
Calculation is performed by addition comparator, and and computings are performed by triode.
The utility model is improved and supplemented to logic unit inside, and parallel processing has been carried out to comparison module, than
Receive the voltage signal of photovoltaic cable and direct current cables respectively compared with module, logical operation is carried out by multiplication comparator component, when
Output signal when meeting difference more than or equal to comparison voltage absolute value, the signal of output is input in addition comparator, reached
It is any to have signal output on the way, then send to execution unit, combined floodgate, the separating brake of breaker are controlled by execution unit.
Logic unit in the utility model is additionally provided with fuse identification module and direct current cables Fault Identification module, uses
Collection voltages value carries out the mode of logical operation, and multi-class identification monitoring logic computing list has been internally formed in logic unit
Member, can carry out handling and analyzing in time, with preferable efficiency to failure.
The beneficial effects of the utility model are：Enough identify multigroup optical crosstalk luff cable failure, direct current cables failure, fuse or
Bolt looseness failure.The error produced in traditional header box protection by method defect is avoided, while protection device is not by week
Enclose illumination and the influence of environment temperature.Therefore, more can be based on safety in actual motion maintenance, the protection device in failure
It is active in one's movements, sound assurance is provided for system security and stability.Moreover, this reduces the possibility of artificial investigation failure,
Reduce the workload of actual operation maintenance personnel.
It should be understood that in the range of the utility model, above-mentioned each technical characteristic of the present utility model and below (strictly according to the facts
Apply mode) in specifically describe each technical characteristic between can be combined with each other, so as to constitute new or preferred technical scheme.
As space is limited, no longer tire out one by one herein and state.
Brief description of the drawings
Fig. 1 is the utility model header box under-voltage protection system structure diagram；
Fig. 2 is the schematic diagram of collecting unit in the utility model；
Fig. 3 is the schematic diagram of logic unit in the utility model；
Fig. 4 is the utility model direct current cables failure schematic diagram；
Fig. 5 is the schematic diagram of fuse failure in the utility model.
Embodiment
Preferred embodiment of the present utility model is described in detail below with reference to accompanying drawing, to become apparent from understanding this reality
With new objects, features and advantages.It should be understood that embodiment shown in the drawings is not the limit to the utility model scope
System, and simply to illustrate that the connotation of technical solutions of the utility model.
Term explanation
Header box：Header box main function is exactly that the input of photovoltaic array is carried out one-level to conflux, for reducing photovoltaic battle array
Row are linked into the line of inverter, while provide lightning protection function, detect the running status of photovoltaic panel, DC quantity state acquisition and disconnected
Road device state etc..
Photovoltaic DC-to-AC converter：Photovoltaic DC-to-AC converter is to connect resistance capacitance by power electronic devices (MOSFET, IGBT etc.), with
The direct current that header box transmission comes, is transformed into alternating current by the break-make of the mode control device of pulse width modulation, is completed simultaneously
The MPPT maximum power point tracking (MPPT) of photovoltaic module, it is ensured that intelligent control and anti-islanding effect etc..
Breaker：Designed coupling or uncoupling means, can close, break-make and carry normal condition electric current；And can be non-
Under normal operating condition, can also be closed, disjunction and the conducting in certain time and break-make.
Gate level turn-off thyristor (GTO)：Gate level turn-off thyristor is that a kind of of IGCT derives from device, can be passed through
Apply pulse current in gate pole and control its break-make；Due to the voltage of the device, current capacity is larger, close with triode thyristor,
Therefore there can be more application in large-power occasions.
A kind of header box protection device, as shown in figure 1, the header box include photovoltaic cable 41,42, direct current cables 43,
44, breaker 60, collecting unit 10, logic unit 20 and execution unit 30.
Collecting unit 10 be used to gather voltage signal on direct current cables and photovoltaic cable branch road, its principle as shown in Fig. 2
The series connection of collecting unit 10 bleeder circuit 11, filter circuit 12, voltage follower 13, photoelectrical coupler 14 and voltage-stabiliser tube 15.UdcFor
DC voltage to be detected, the voltage signal that Hall voltage sensor is collected makes its voltage be limited in properly by bleeder circuit 11
Scope；RC wave filters 12 filter out the noise in collection signal；Voltage follower 13 may insure output signal not by input electricity
The interference of the resistance on road, plays a part of preventing voltge surge；Photoelectrical coupler 14 effectively realizes the electricity blocked between circuit
Contact, and the transmission of the signal between them is not cut off, isolation performance is good, stable and reliable in work not by Electromagnetic Interference；Voltage stabilizing
Pipe 15 is by output voltage UpotCertain limit is limited in, plays a part of protection circuit.
Logic unit 20 including multiple comparison modules 21, direct current cables Fault Identification module 22, fuse as shown in figure 3, know
Other module 23 and protection module 24.Each comparison module 21, direct current cables Fault Identification module 22 and fuse identification module 23 are simultaneously
Connection, although the signal that input is received is different, single output end interflow access execution unit.Each comparison module 21 is by operation amplifier electricity
Road, multiplication comparator component composition.The difference of each comparison module 21 is that the magnitude of voltage accessed is different, and one of them compares mould
Block 21 accesses the voltage U of direct current cablesz+And Uz-, remaining comparison module is respectively connected to U1+、U1-, U2+、U2-……Un+、Un-。
Wherein, operational amplification circuit is connected by two operational amplifiers, wherein an operational amplifier input signal is cable positive pole and connect
Ground, by taking the comparator for accessing photovoltaic cable as an example, cable just extremely U1+, the output signal of the operational amplifier inputted to another fortune
Calculate in amplifier, another connection end and the cable negative pole U of another operational amplifier1-Connection.Operational amplifier is operated in linear zone,
The voltage U of operational amplifier outputa.Multiplication comparator component is by two analog multipliers and is connected to comparator and constitutes, and simulation multiplies
Musical instruments used in a Buddhist or Taoist mass has two input terminals and a lead-out terminal.Same analog physical amount during input signal, exporting electric expression formula is：
Uc=kUε1 2
Ud=kUb 2=k (U1--U1+)2
Wherein k represents scaling factor, and its value is generally 0.1V-1.Comparator in multiplier group is operated between inelastic region, defeated
Go out signal and there was only high level and low level.As signal UdMore than UcWhen, comparator A3Output voltage Ue=UOH, output voltage Uh
=UOH；As signal UdLess than Uc, comparator output voltage U01=-UOH, output voltage Uh=0.
Addition comparator 25 is made up of adder and zero-crossing comparator, and adder is the plus-minus fortune realized by operational amplifier
Circuit is calculated, when the voltage of n input is respectively Uh1、Uh2、UhnWhen, output end voltage UdFor：
Voltage UgCompared by zero-crossing comparator with 0 value, work as UgMore than 0, voltage UfFor high level signal；Work as UgLess than 0
When, voltage UfFor low level signal.So, it represents to work as in photovoltaic cable n bar branch roads, and earth fault occurs in any one branch road
When, UfFor high level signal.
Multiplication comparator component of the present utility model makes absolute value judgement to the difference of voltage signal and comparison voltage, when exhausted
Header box short-circuiting device shutoff signal is exported when being more than or equal to setting value to value.Comparison voltage is equal to 380V-400V, Yi Jishe
Definite value is equal to 190V-320V.For receiving direct current cables voltage Uz+And Uz-Comparison module 21, its structure is also identical, many
Parallel relationship between individual comparison module 21 is mainly collaborated into addition comparator 25 by the output end of multiplication comparator group.
Logic unit 20 also includes direct current cables Fault Identification module 22, and it is comprising positive DC cable identification module and bears
Pole direct current cables identification module, the difference of positive DC cable identification module and negative DC cable identification module is, described
Positive DC cable identification module access photovoltaic DC-to-AC converter side and direct current cables on positive voltage, and described negative DC electricity
The negative voltage that cable identification module is accessed on photovoltaic DC-to-AC converter side and direct current cables.Two direct current cables identification modules include computing
Amplifier, comparator and diode, the voltage signal of operational amplifier access direct current cables and the voltage letter of photovoltaic DC-to-AC converter side
Number, by taking positive DC cable identification module as an example, operational amplifier access Um+And Uz+, opamp-output signal access ratio
Compared with device, another arrival end of comparator accesses the threshold value U comparedε3, the output end access diode of comparator, any identification module
In the voltage signal of photovoltaic DC-to-AC converter side and the difference of voltage signal on direct current cables when being more than the threshold value of comparison voltage, output converges
Flow case trip signal.
The logical schematic of direct current cables Fault Identification module 22 is as shown in figure 4, when the direct current cables of collecting unit collection
Voltage UZ+、UZ-Compare both sizes by comparator, meet inequality | UZ+-UZ-|>Uε1When, it is possible to determine that it is direct current cables
Failure, such as trouble point f1, or photovoltaic DC-to-AC converter DC side failure, such as trouble point f2。l1For trouble point f1To the l that confluxes1The distance of case,
l2For trouble point f1To the distance of photovoltaic DC-to-AC converter, l is the overall length of direct current cables between header box and photovoltaic DC-to-AC converter.This practicality
It is new to compare the direct current cables voltage of header box side and the direct current cables voltage of photovoltaic DC-to-AC converter side to identify by comparator
Direct current cables failure and photovoltaic DC-to-AC converter DC side failure.
When under photovoltaic DC-to-AC converter DC side failure, the electric current flowed through on direct current cables is I.Due to photovoltaic module opto-electronic conversion
Particularity, the value under the size and normal operating condition of the current value is more or less the same.Header box side and photovoltaic DC-to-AC converter side electricity
Cable voltage is respectively Um、UzFunctional relation meet expression formula (1)：
Um-Uz=lIR (1)
R is the resistance of element length direct current cables in formula.
Because cable length l is little, therefore expression formula Um-UzVery little, can be less than threshold voltage Uε3。
|Um-Uz|<Uε3 (2)
When earth fault occurs for direct current cables, all electric currents flowed through can be by DC cabinet on normal direct current cables
Bus goes out conflux after " anti-fill " arrive failure cable.
Header box side and photovoltaic DC-to-AC converter side voltage cable are respectively Um、UnFunctional relation meet expression formula (2)
Um-Uz=l1I1R-l2I2R (3)
Now, anti-sink current value I2Size by other parallel connection header box in square formation the summation for flowing through electric current.
|Um-Uz|>Uε3 (4)
Direct current cables failure and photovoltaic DC-to-AC converter DC side failure are identified according to formula (2) and formula (4).Work as direct current cables
During failure, header box circuit breaker trip, and header box trip signal is passed to by RS485 connections.It is of the present utility model heavy
Point is the protection system for studying a kind of photovoltaic combiner box, and photovoltaic DC-to-AC converter DC side failure is not belonging to the utility model research
Content, does not illustrate herein.
Direct current cables identification module 22 passes through triode T3It is connected with the comparison module of direct current cables, receives direct current cables electricity
The output end of the multiplication comparator component in the comparison module of signal is pressed to access the triode T3Colelctor electrode, the direct current
The output end of cable Fault Identification module accesses the triode T3Base stage, T3Emitter stage is connected in addition comparator 25.
Construction and equipment quality are also to influence the key factor of photovoltaic power station power generation.The use of fuse and bolt is added directly
Node is flowed, is that the O＆M in power station hides some dangers for safely.Fuse block and bolt are high to cable construction quality requirement, often contact
Bad phenomenon, causes header box arcing or burns phenomenon.It is electric equivalent to having concatenated one at node during due to loose contact
Resistance, such as Fig. 4 shows.Therefore fuse identification module is set in logic unit, and fuse identification module is with bolt looseness identification module
Identical meanings.Fuse identification module 23 includes positive pole fuse identification module and negative pole fuse identification module in parallel, positive pole fuse
The difference of identification module and negative pole fuse identification module is, positive pole fuse identification module access photovoltaic cable and direct current cables
The negative voltage of positive voltage, negative pole fuse identification module access photovoltaic cable and direct current cables, described fuse identification module includes
Operational amplifier, comparator and diode, by taking positive pole fuse identification module as an example, U1+、 U2+……UnIt is in parallel after series diode
Enter operational amplifier, the output end access comparator of operational amplifier, comparator also accesses comparison voltage Uε2, the output of comparator
Terminate into diode, realize that the voltage cable signal of direct current of negative or positive electrode identification module is more than with the difference of photovoltaic cable and compared
Voltage, sends to the execution unit and instructs.Principle such as Fig. 5, UkFor the voltage of photovoltaic cable, UlFor direct current cables voltage.Its
In, UkWith UlRelational expression be：
Uk-Ul=IR (5)
Photovoltaic cable is compared by comparator and direct current cables voltage difference meets inequality Uk-Ul>Uε2, to identify fuse
Or the loosening of bolt, so as to control dc circuit breaker to trip.
The output end interflow of described direct current cables identification module 22, comparison module 21 and fuse identification module 23 is input to
Addition comparator 25, the output end of addition comparator 25 connection protection circuit 24, protection circuit 24 is connected with execution unit.
Wherein, logic unit also includes triode T2, triode T described in the signal that comparison module in parallel is exported2Current collection
Pole, triode T3Emitter stage access triode T2Base stage, the triode T2Emitter stage connection guide wire.Guide wire 70
For RS485 guide wires.
Execution unit, which includes control gate pole, can cut-off IGCT.
Voltage protection system is to realize that dc circuit breaker is closed by Control contactor break-make to divide in the prior art
Lock function.The utility model can cut-off IGCT using gate pole, make DC current start from scratch it is steady rise, can not only realize
The system without deaerator of circuit, and can prevent electric current and voltage in the spring coil in breaker from causing in control process
Overvoltage.Therefore, control system of the present utility model be active in one's movements, stability it is strong.
When logic unit output signal switching signal 001, sub-gate signal 002, respective gate pole can cut-off IGCT injection
Gate current Ig, gate pole can cut-off IGCT be in forward bias, anode current is with IgIncrease and gradually increase, until gate pole
IGCT can be cut-off and enter conducting state.Conventionally used Control contactor break-make realizes dc circuit breaker on/off switch
During, the coil in relay is damaged because dash current is excessive, needed between relay and contactor exist electrically connect, therefore
Barrier rate is high.The utility model overcomes the shortcoming of relay, and during dc circuit breaker on/off switch, DC current is started from scratch
It is steady to rise, the system without deaerator of circuit can not only be realized, and the electric current in the spring coil in breaker can be prevented
With voltage in control process caused by overvoltage.
Preferred embodiment of the present utility model is described in detail above, it is understood that understanding this practicality newly reading
After the above-mentioned instruction content of type, those skilled in the art can make various changes or modifications to the utility model, and these are of equal value
Form equally falls within the application appended claims limited range.
Claims (10)
1. a kind of header box protection device, the header box includes photovoltaic cable, direct current cables and breaker, it is characterised in that
The header box protection device includes collecting unit, logic unit and execution unit；With
Voltage signal on the voltage signal and at least one photovoltaic cable branch road of the collecting unit collection direct current cables；With
Described logic unit includes at least two comparison modules in parallel, and comparison module is electrically connected with the collecting unit, its
In comparison module receive voltage signal on the direct current cables, other comparison modules receive the photovoltaic cable branch road
Voltage signal, comparison module includes multiplication comparator component, multiplication comparator component access voltage signal and comparison voltage,
The output end of each multiplication comparator component is linked into the input of addition comparator component, the output termination of addition comparator component
Enter execution unit, to described when the absolute value of voltage signal and the comparison voltage difference of any comparison module is more than or equal to setting value
Execution unit sends circuit breaker trip instruction；With
The instruction that the execution unit is electrically connected with the logic unit and transmitted according to the logic unit controls the open circuit
Device separating brake.
2. header box protection device according to claim 1, it is characterised in that
Also include guide wire；
The collecting unit also gathers the voltage signal of photovoltaic DC-to-AC converter side；With
Described logic unit also includes direct current cables Fault Identification module, and direct current cables identification module is in parallel with comparison module,
The direct current cables Fault Identification module receives the voltage signal of photovoltaic DC-to-AC converter side, on direct current cables voltage signal and comparison it is electric
The poor absolute value of voltage signal is more than the threshold value of comparison voltage on pressure, the voltage signal and direct current cables of photovoltaic DC-to-AC converter side
When, header box trip signal is exported, header box trip signal is sent to photovoltaic DC-to-AC converter by guide wire, controls photovoltaic DC-to-AC converter
The dc circuit breaker tripping operation of side.
3. header box protection device according to claim 2, it is characterised in that the logic unit also includes triode T3,
The output end for receiving the multiplication comparator component in the comparison module of direct current cables voltage signal accesses the triode T3Collection
Electrode, the output end of the direct current cables Fault Identification module accesses the triode T3Base stage, the triode T3Transmitting
Pole is connected with guide wire, and triode T3In emitter stage access addition comparator, when the voltage signal and direct current of photovoltaic DC-to-AC converter
On cable the difference of voltage signal be more than comparator voltage threshold value, and receive direct current cables comparison module voltage signal with than
Absolute value compared with voltage difference sends to execution unit when being more than or equal to setting value and instructed.
4. header box protection device according to claim 3, it is characterised in that the logic unit also includes triode T2,
The signal of comparison module output in parallel accesses the triode T2Colelctor electrode, triode T3Emitter stage access triode T2
Base stage, the triode T2Emitter stage connection guide wire.
5. header box protection device according to claim 3, it is characterised in that described direct current cables Fault Identification module
Including operational amplifier and comparator, the operational amplifier is accessed on the voltage signal and direct current cables of photovoltaic DC-to-AC converter side
Voltage signal, the input of comparator is respectively connected to the output end and comparison voltage of operational amplifier.
6. header box protection device according to claim 1, it is characterised in that the logic unit also includes fuse and recognized
Module, fuse identification module is in parallel with comparison module, and the fuse identification module receives voltage signal, the photovoltaic electric of direct current cables
The voltage signal and comparison voltage of cable, are compared electric when the voltage signal of direct current cables is more than with the difference of the voltage signal of photovoltaic cable
Pressure, sends to the execution unit and instructs.
7. header box protection device according to claim 6, it is characterised in that described logic unit also includes protection mould
Block, the output signal access protection module of comparison module in parallel is connected, and protection module outputs signal to execution unit.
8. header box protection device according to claim 1, it is characterised in that
Voltage signal on the voltage signal and at least two photovoltaic cable branch roads of the collecting unit collection direct current cables；With
Described logic unit includes at least three comparison modules in parallel, and one of comparison module receives the direct current cables
On voltage signal, separately there are at least two comparison modules to receive the voltage signal of the photovoltaic cable branch road, receive optical cable branch road
Each comparison module of voltage signal receives the voltage signal on respectively different photovoltaic cable branch road.
9. header box protection device according to claim 1, it is characterised in that described execution unit, which includes gate pole, to be opened
Disconnected IGCT.
10. header box protection device according to claim 1, it is characterised in that described collecting unit includes connecting successively
Bleeder circuit, wave filter, voltage follower, photoelectrical coupler and the voltage-stabiliser tube connect.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201621307938.9U CN206349742U (en) | 2016-11-30 | 2016-11-30 | A kind of header box protection device |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201621307938.9U CN206349742U (en) | 2016-11-30 | 2016-11-30 | A kind of header box protection device |
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| CN206349742U true CN206349742U (en) | 2017-07-21 |
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| CN201621307938.9U Active CN206349742U (en) | 2016-11-30 | 2016-11-30 | A kind of header box protection device |
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Cited By (1)
| 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 |
-
2016
- 2016-11-30 CN CN201621307938.9U patent/CN206349742U/en active Active
Cited By (2)
| 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 |
| 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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