CN203722250U - Photovoltaic device - Google Patents
Photovoltaic device Download PDFInfo
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- CN203722250U CN203722250U CN201320692629.8U CN201320692629U CN203722250U CN 203722250 U CN203722250 U CN 203722250U CN 201320692629 U CN201320692629 U CN 201320692629U CN 203722250 U CN203722250 U CN 203722250U
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- 239000004065 semiconductor Substances 0.000 claims description 16
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- 238000000429 assembly Methods 0.000 claims 1
- 230000005540 biological transmission Effects 0.000 abstract description 5
- 230000001681 protective effect Effects 0.000 abstract description 5
- 238000013461 design Methods 0.000 description 11
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- 239000000463 material Substances 0.000 description 5
- 230000008859 change Effects 0.000 description 4
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- 238000012423 maintenance Methods 0.000 description 3
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Classifications
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/10—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers
- H02H7/12—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers
- H02H7/122—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers for inverters, i.e. dc/ac converters
- H02H7/1222—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers for inverters, i.e. dc/ac converters responsive to abnormalities in the input circuit, e.g. transients in the DC input
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
- H02J3/381—Dispersed generators
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
- H02J3/46—Controlling of the sharing of output between the generators, converters, or transformers
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/20—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for electronic equipment
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J2300/00—Systems for supplying or distributing electric power characterised by decentralized, dispersed, or local generation
- H02J2300/20—The dispersed energy generation being of renewable origin
- H02J2300/22—The renewable source being solar energy
- H02J2300/24—The renewable source being solar energy of photovoltaic origin
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/50—Photovoltaic [PV] energy
- Y02E10/56—Power conversion systems, e.g. maximum power point trackers
Abstract
The utility model relates to a photovoltaic device including at least one inverter and at least one photovoltaic sub-generator (11). The inverter is connected to an energy supply network (70) through an AC disconnector (51) used for transmitting electric power. The photovoltaic generator includes at least one photovoltaic string (12), and connected to a direct current joining region (30) of at least one inverter through a direct current lead (20). The characteristics of the photovoltaic device are that: a direct current separating element (14), a direct current short circuit switch (16) and a countercurrent protective device are allocated to at least one photovoltaic generator (11) along the energy flow direction; the direct current separating element (14) is nearby a generator; the direct current short circuit switch (16) after the direct current separating element (14) and used for short connecting at least one photovoltaic string (12) of the photovoltaic generator (11) along an energy flow direction during the transmission; the countercurrent protective device is serially connected after the direct current short circuit switch (16) along the energy flow direction; and an AC short-circuit switch (52) is disposed before the AC disconnector (51) along the energy flow direction.
Description
Technical field
The utility model relates to a kind of photovoltaic devices that contains at least one inverter and the sub-generator of at least one photovoltaic, this inverter is connected with energy resource supply network by the interchange disconnecting device for delivery of electric power, and the sub-generator of this photovoltaic has respectively at least one photovoltaic string and the direct current bonding pad by DC wire and at least one inverter is connected.
Background technology
For larger photovoltaic devices, especially open installation, is usually designed to the electric power of generation is delivered directly in middle pressure energy resource supply network, hereinafter referred to as middle-voltage network.This middle-voltage network can be 20 kilovolts of (kV) electrical networks for example.This open installation generally has a plurality of photovoltaic modules, wherein several photovoltaic modules so-called photovoltaic string of connecting respectively.Conventionally several photovoltaic strings are in parallel, the photovoltaic module group who is wherein included in this parallel photovoltaic string forms a closed generator unit, and this generator unit is following also referred to as the sub-generator of photovoltaic.
The inverter that is arranged in center or is distributed in a plurality of positions, photovoltaic devices inside is conventionally set in larger open installation.Inverter for higher power can be divided into three regions, direct current (DC especially; Direct current) bonding pad, the power zone of containing one or more DC-AC current transformers and alternating current (AC; Alternating current) bonding pad.At alternating current one side inverter, for example, by exchanging disconnecting device (can be formed by switch and/or protector), be connected with transformer.Wherein can be for each inverter arranges a transformer, or a plurality of inverter can be connected by independent armature winding if desired with a transformer.
This System Construction of photovoltaic devices is for example at article " for the electric fault protection system (Electrical Fault Protection for Large Photovoltaic Power Plant Inverter) of large-sized photovoltaic power station inverter " (D.E.Collier and T.S.Key; photovoltaic specialists meeting; IEEE minutes, 1988) known in.For the wherein listed different faults that causes destroying photovoltaic devices parts, first disconnect and exchange disconnecting device, for photovoltaic devices and middle-voltage network are disconnected.This external direct current bonding pad at least arranges a direct current disconnecting device, and this direct current disconnecting device also can disconnect under failure condition, and the power zone of photovoltaic generator and inverter disconnects thus.
If photovoltaic devices inside exists fault, along with combining, the small electric sense of the increased power of one or more inverters and short-circuit power consequential energy resource supply network, the larger transformer good with performance increased the short circuit current that may occur in inverter or other device feature inside.This fault may be due to the short circuit in DC wire for example, and these DC wires are connected the direct current bonding pad of the sub-generator of photovoltaic and inverter.In addition, short circuit may occur in direct current bonding pad, or the semiconductor of damage that also may be by one of them the DC-AC current transformer inside in inverter power district causes.In all such situations, the electric current of the sub-generator of unaffected photovoltaic or flow on one side the electric current of photovoltaic devices by being arranged in the fly-wheel diode of inverter through alternating current from energy resource supply network may destroy the assembly of the sub-generator of photovoltaic and/or inverter thereupon.Due to that constantly increase, direct current one side and alternating current electric current on one side; it is along with the unit scale going from strength to strength can circulate all the time under failure condition always; until open the time of relatively slow interchange disconnecting device, may be not enough to protect inverter and the sub-generator assembly of photovoltaic not to be destroyed.
Publication DE 10 2,009 038 209 A1 have described a kind of alternating current low-voltage device, and especially a kind of wind force device is transported to middle pressure energy resource supply network by the energy of generator by transformer and middle pressure transformer in this wind force device.Wherein between transformer and middle pressure transformer, be provided with short switch, for example, for when generating pusher side breaks down (electric arc or short circuit), prevent that the overload current of being supplied with by energy resource supply network from flowing to the low-pressure end of generating pusher side.At low-pressure end, can omit protector thus.Yet overload current that can not sub-generator causes for the photovoltaic by non-fault in the photovoltaic devices that contains the sub-generator of a plurality of photovoltaics is protected this device.Even when device only has a sub-generator of photovoltaic, the imperative operation of short switch neither be for suppressing always favourable from the electric current of middle-voltage network in all faults.So will again prepare and change disposable short switch in order to new operation.Yet the preparation of this disposable short switch and replacing are that high consumption is connected with no small ordinary disbursements, and it need carry out in pressure situation, and should avoid in other cases.
Summary of the invention
Therefore the purpose of this utility model is, the photovoltaic devices of mentioned kind is provided, and the assembly of this photovoltaic devices will be protected reliably under failure condition.
This object will realize by the photovoltaic devices that comprises at least one inverter, and this inverter is connected with energy resource supply network by the interchange disconnecting device for delivery of electric power.In addition this photovoltaic devices has the sub-generator of at least one photovoltaic, and the sub-generator of each photovoltaic has at least one photovoltaic string, and is connected by the direct current bonding pad of DC wire and at least one inverter.
According to photovoltaic devices of the present utility model, mentioned kind, be characterised in that; by the direct current resolution element of generator-near, in conveying after energy flow direction is connected on direct current resolution element, for direct-current short circuit switch and the reverse current protection device after energy flow direction is connected on direct-current short circuit switch of at least one photovoltaic string short circuit of the sub-generator of short circuit photovoltaic, distribute to the sub-generator of at least one photovoltaic, and before exchanging disconnecting device, settled ac short circuit switch along energy flow direction.
By closed direct-current short circuit switch in the sub-generator of at least one photovoltaic, on one side the sub-generator of the electric current that can when fault, direct current be introduced and at least one photovoltaic disconnects.Photovoltaic string and the photovoltaic module being placed in wherein can be because the short circuit producing by direct-current short circuit switch is transshipped, because this direct-current short circuit switch arranges for short circuit current, and short-circuit conditions is expressed as the working point of a permission on the current-voltage characteristic curve of direct-current short circuit switch.In addition, can disconnect in time the sub-generator of at least one photovoltaic by direct current resolution element, for example for maintenance object by corresponding photovoltaic string power-off.When there is the sub-generator of a plurality of photovoltaics, can by short circuit and possible disconnection be confined to the sub-generator of out of order photovoltaic or at the sub-generator of the photovoltaic that has faulty components to be connected with afterwards.By reverse current protection device, can prevent that high adverse current is from the sub-generator of other photovoltaic of short circuit or flow to direct-current short circuit switch from inverter not also.By closing ac short circuit switch, can prevent that electric current does not flow to inverter from energy resource supply network through transformer with no small amount during interchange disconnecting device is also opened.It is short by exchanging the switching time that disconnecting device can realize that this is on-off time ratio based on realizing by ac short circuit switch.
In the design of a favourable photovoltaic devices, direct-current short circuit switch is semiconductor switch, and reverse current protection device is counterflow-preventing diode.Semiconductor switch and reverse current protection device are preferably the assembly of the boost converter of distributing to the sub-generator of photovoltaic.Said modules can be boost converter in the running in service of photovoltaic devices.Can realize the high voltage on DC wire thus, and correspondingly reduce the ohmic loss in this DC wire.When photovoltaic devices is installed, can consider thus that application has a smaller cross-sectional area and save the DC wire of material and expense thereupon.
In the first, be used for according to the method for operation of the photovoltaic devices containing a plurality of photovoltaic strings of the present utility model, while being particularly short-circuited in photovoltaic devices inside when fault, to carry out following step: the alternating current output of at least one DC-AC current transformer of inverter will the short circuit by ac short circuit switch, photovoltaic string is by being placed in the direct current resolution element of generator-near and the direct current input of at least one DC-AC current transformer disconnects mutually, and alternating current output and energy resource supply network disconnect.When there is short circuit or Similar Problems in inverter region, this method of operation is advantageous particularly.Short circuit by the one-side disconnection of photovoltaic string and the alternating current output realized has fast realized direct current on one side and the high short circuit current on alternating current one side all can not flow to inverter region, otherwise this high short circuit current may cause the destruction in inverter region or catch fire.The opening of direct current resolution element that is placed in generator-near may be accompanied by closing of direct-current short circuit switch.This be based on direct-current short circuit switch close generally than be placed in generator-near direct current resolution element open faster.Can suppress quickly thus electric current flows to along going the fault element of energy flow direction series connection from relevant photovoltaic generator.
At the second, be used for according to the method for operation of the photovoltaic devices containing a plurality of photovoltaic strings of the present utility model, while being particularly short-circuited in photovoltaic devices inside when fault, following step will be carried out: photovoltaic string is by being placed in the direct current resolution element of generator-near and the direct current input of at least one DC-AC current transformer disconnects mutually, electric current in DC wire interrupts by being placed in the disconnection of the DC insurance silk in direct current bonding pad, and wherein photovoltaic string is connected by the direct current bonding pad of this DC wire and DC-AC current transformer.By the method, can advantageously reduce in DC wire region or likely be placed in the Damage by Short Circuit that the boost converter region between DC wire and photovoltaic string occurs.Direct current resolution element has stoped electric current to flow into fault zone from photovoltaic string.Although the above-mentioned short circuit current that can bear relative photovoltaic string at the DC insurance silk of direct current bonding pad, can not bear from the electric current that may differ in size of the sub-generator of a plurality of incoherent photovoltaic and the electric current that flows into fault zone through inverter.Above-mentioned electric current can disconnect other electric current in other fuse outage region.The opening also of direct current resolution element that is wherein placed in generator-near can be followed closing of direct-current short circuit switch simultaneously.This be also based on direct-current short circuit switch close generally than be placed in generator-near direct current resolution element open sooner, will suppress quickly thus electric current and flow into along the fault element of energy flow direction series connection from relevant photovoltaic generator.
At the third for according to the method for operation of the photovoltaic devices containing a plurality of photovoltaic strings of the present utility model, while being particularly short-circuited in photovoltaic devices inside when fault, following step will be carried out: photovoltaic string is directly short-circuited by being placed in the direct-current short circuit switch of generator-near, and photovoltaic string disconnects by direct current resolution element and the direct-current short circuit switch being placed between photovoltaic string and direct-current short circuit switch.When break down in photovoltaic string region can by the connection order of direct-current short circuit switch and direct current resolution element first by the quick no-voltage of photovoltaic string connect, then for example in order to maintain and to repair or in order to suppress serial arc, photovoltaic string being disconnected.
According to another design of the present utility model, the sub-generator of at least one photovoltaic is also furnished with inductance and the electric capacity as the assembly of boost converter in addition.
According to another design of the present utility model, at least one photovoltaic string is furnished with at least one DC insurance silk.
According to another design of the present utility model, at least one photovoltaic string has at least another function element, for example current measuring device, overvoltage semiconductor, leakage switch detector or arc-fault circuit interrupter parts.
According to another design of the present utility model, the DC wire that is connected to inverter from the sub-generator of at least one photovoltaic is directly connected with the direct-flow input end of at least one DC-AC current transformer by other DC insurance silk in direct current bonding pad, does not particularly wherein arrange and inserts disconnecting device.
According to another design of the present utility model, ac short circuit switch has at least one semiconductor switch.
According to another design of the present utility model, the switch motion of ac short circuit switch triggers the method by pyrotechnics.
According to another design of the present utility model, direct current resolution element has two single-pole switchs that can control separately.
According to another design of the present utility model, have and be placed in the transformer exchanging between disconnecting device and energy resource supply network.
Accompanying drawing explanation
Below embodiment with reference to the accompanying drawings is further illustrated to the utility model.
This figure shows a kind of embodiment of photovoltaic devices with the form of calcspar.This photovoltaic devices has the sub-generator 11 of a plurality of photovoltaics in dynamo region 10, has wherein for the sake of clarity only described two in the drawings.
Description of reference numerals
10 dynamo regions
The sub-generator of 11 photovoltaic
12 photovoltaic strings
13 DC insurance silks (string fuse)
14 direct current resolution elements
141,142 single-pole switchs
15 boost converters
16 direct-current short circuit switches
17 counterflow-preventing diodes
18 inductance
19 electric capacity
20 DC wires
30 direct current bonding pads
31 direct current bus-bars
32 other DC insurance silks
33 disconnecting device installation positions
34 measurement points
40 power zones
41 DC-AC current transformers
42 intermediate loop electric capacity
43 filters
50 alternating current bonding pads
51 exchange disconnecting device
52 ac short circuit switches
60 transformers
70 energy resource supply networks
Embodiment
The sub-generator 11 of photovoltaic is connected with inverter by DC wire (DC wire) 20, and this inverter forms so-called central inverter in an illustrated embodiment.The name of central authorities' inverter is not limited in the present embodiment and is interpreted as to have unique how much middle grounds to be placed in the inverter of photovoltaic devices inside.Definitely a plurality of these central authorities' inverters can be set in photovoltaic devices inside, it also can be arranged in the fringe region of device.And these so-called central authorities of central authorities' inverter refer to not to be to be provided with corresponding inverter for the sub-generator of each photovoltaic, just as in the device design less often.That below further illustrates also can change by inverter according to structure of the present utility model, photovoltaic devices, and these inverters are only corresponding with a sub-generator of photovoltaic respectively.
Central authorities' inverter has three regions, i.e. direct current bonding pad 30, power zone 40 and alternating current bonding pad 50.By direct current bonding pad 30, this central authorities' inverter by with shown in the sub-generator 11 of photovoltaic and other, for the sake of clarity the sub-generator of unshowned photovoltaic is connected.By alternating current bonding pad 50, this central authorities' inverter is connected to for example middle-voltage network of energy resource supply network 70(through transformer 60) on.Energy resource supply network 70 also as transformer 60, power zone 40 and alternating current bonding pad 50 with three-phase arrange.For the transformer at low-pressure end with Y-connection, can in addition zero line be connected in inverter bonding pad.Under failure condition, this zero line can be connected or disconnected.This zero line can ground connection.For the energy resource supply network with other certain number of phases, obviously can corresponding adjustment will be done according to photovoltaic devices of the present utility model.
The sub-generator 11 of photovoltaic respectively comprises the photovoltaic string 12 of a plurality of parallel connections in an illustrated embodiment, and each photovoltaic string is formed by the photovoltaic module of a plurality of series connection by known method.By the independent photocell of mark, to the expression of photovoltaic string 12, can symbolically understand according to this implication in the drawings.
Wherein each photovoltaic string 12 is assigned the DC insurance silk 13 of at least one series connection.After this DC insurance silk 13, also will be expressed as string fuse 13.Each photovoltaic string 12 is provided with 13, one connections of the positive poles at photovoltaic string 12 of two string fuses in an illustrated embodiment, and another connects at negative pole.According to the short-circuit-type of photovoltaic string 12 inside, for example, when ground connection, may produce short circuit current, this short circuit current cannot only obtain by a string fuse 13.
The sub-generator 11 of each photovoltaic is furnished with an one pole or bipolar direct current resolution element 14 and follow-up boost converter 15.Wherein the name of " follow-up " and at conveying capacity the energy flow directional correlation during to energy resource supply network 70.Preferably direct current resolution element 14 with bipolar containing two single-pole switchs that can regulate and control separately 141 and 142 and form.Preferably switch 141,142 is motor switch, and wherein at least any one has for avoiding and eliminate the instrument of switching arc in switch 141,142.Corresponding instrument for blow-out magnet for example, be parallel to semiconductor switch, PTC element or like that the switch contact of motor switch 141,142 is settled, its in the switch motion of at least one motor switch 141,142 for electric current provides commutation approach.
Boost converter 15 has direct-current short circuit switch 16, can be by sub-generator 11 short circuits of photovoltaic by this direct-current short circuit switch.This direct-current short circuit switch 16 has high current increases rate and the corresponding high switching speed within the scope of several milliseconds.
Except direct-current short circuit switch 16, this boost converter 15 also has counterflow-preventing diode 17, inductance 18 and electric capacity 19.Inductance 18, direct-current short circuit switch 16, counterflow-preventing diode 17 form boost converter when being connected in mutually the pulse operation of direct-current short circuit switch 16 with electric capacity 19, it is DC-DC converter, this boost converter has been realized the photovoltaic voltage being produced by photovoltaic string 12 has been converted to higher output voltage, then this output voltage is loaded on DC wire 20.In the operation of photovoltaic devices, protective device also can be applied to reduce the ohmic loss in this DC wire 20 by the high voltage on DC wire 20 as boost converter operation thus.Can advantageously affect the overall efficiency of photovoltaic devices thus.When photovoltaic devices is installed, can consider thus that application has a smaller cross-sectional area and save the DC wire 20 of material and expense thereupon.Another advantage that is placed in the boost converter 15 in the middle of dynamo region 10 is, the variation of the voltage conversion ratio by boost converter 15 can be adjusted individually for the sub-generator 11 of each photovoltaic the working point of photovoltaic string 12.Also can when there is photovoltaic devices partial occlusion, the sub-generator 11 of photovoltaic be moved at its best operating point separately thus.
Can be used for monitoring isolated fault or settle arc-fault circuit interrupter (AFCI) parts to be used for monitoring and inhibition electric arc by 10 arrangement leakage switch detectors (RCD) in dynamo region in addition.
In addition direct-current short circuit switch 16 and direct current resolution element 14 and possible after together with other protection switch of illustrating the safety as photovoltaic devices part is set, be used in particular for protecting photovoltaic devices in order to avoid photovoltaic devices inside is short-circuited.In photovoltaic devices, do not have boost converter to be connected on the sub-generator of photovoltaic 11 below time; above-mentioned direct-current short circuit switch 16 can be as the assembly of the protective device of generator-near, and boost converter 15 also has the effect of protective device in the above-described embodiments except the effect of its boost conversion.
DC wire 20 joins in direct current bonding pad 30 and central inverter.This direct current bonding pad provides the direct current bus-bar 31 of cascade if desired, and on this direct current bus-bar, the sub-generator 11 of photovoltaic is linked together by other DC insurance silk 32 respectively.In order to monitor radiation, when possibly regulate and control photovoltaic devices, optional measurement point 34 is set in addition, for example, for current measurement.In addition, one of them direct current bus-bar 31 can be set to and specify in potential with respect to ground wire current potential PE, for example ground connection.Can prevent the premature aging of the sub-generator 11 of photovoltaic thus.As shown in FIG., this type of ground connection can be realized by Earth Fault Detection and interruption (GFDI) element 35, with can be in the sub-generator of photovoltaic monitoring grounding fault.
In addition there is shown the installation position 33 for DC switch.As after will further illustrate, this installation position 33 is for according to the System Construction of the photovoltaic devices of prior art highly significant.Yet also for example by cable testing bridge, replacing according to omitting set DC switch in photovoltaic devices of the present utility model.
In the power zone 40 of central inverter, settled one or more DC-AC current transformers 41, wherein in this case only show two for the purpose of clear.At direct current on one side, the direct current bus-bar 31 in this DC-AC current transformer 41 and direct current bonding pad 30 joins.Conventionally the direct current on DC-AC current transformer 41 is provided with intermediate loop electric capacity on one side.As shown in FIG., this intermediate loop electric capacity can be a total intermediate loop electric capacity 42, or also can be placed in each DC-AC current transformer 41.At alternating current on one side, in order to form, be the output voltage of sinusoidal form as far as possible, after filter 43 is connected in series to DC-AC current transformer 41.This filter 43 comprises exemplary connected with each other by the inductance of rounded projections arranged and electric capacity in an illustrated embodiment.This filter 43 is often also expressed as sinusoidal filter because of its function.
Three alternating current outputs of above-mentioned power zone 40 will 50 transfer to transformer 60 through the interchange disconnecting device 51 that is arranged on that in alternating current bonding pad.Exchanging disconnecting device 51 can be for example be contactor, circuit breaker, electric loading isolating switch or also can being combined to form by one or more fuses or this class component.
In addition alternating current bonding pad 50 has ac short circuit switch 52, and this ac short circuit switch is in order being arranged on of power zone 40 to be exchanged to the short circuit and arranging each other of three outputs before disconnecting device 51 when activating on transmitting energy flow path direction.Ac short circuit switch 52 is symbolically expressed as mechanical switch in the drawings.In the operation of photovoltaic devices, ac short circuit switch 52 is preferably semiconductor switch, for ensureing short as far as possible switching time.In other operation, ac short circuit switch 52 is mechanical switching mechanisms, and the switching manipulation of this mechanical switch mechanism triggers the mode of operation by pyrotechnics at high speed.Ac short circuit switch 52 is characterised in that, can in very short time range, (for example, within one millisecond) close.In an illustrated embodiment ac short circuit switch 52 be placed in to filter 43 and exchange between disconnecting device 51.
In the first method of operation, particularly 30 inner or while being short-circuited in 40 inside, power zone of inverter in direct current bonding pad while breaking down, be arranged to the alternating current output of at least one DC-AC current transformer 41 to carry out short circuit by ac short circuit switch 52, and the photovoltaic string 12 of the sub-generator 11 of photovoltaic is disconnected with direct current bonding pad 30 by being placed in the direct current resolution element 14 of generator-near.By the one-side disconnection of photovoltaic string 12 and fast as far as possible short circuit alternating current output, the large short circuit current of realizing direct current one side and alternating current one side all can not be flowed into (being 30Huo power zone, direct current bonding pad 40) in inverter region, otherwise can produce there, destroy or catch fire.
By being placed in the direct current resolution element 14 of generator-near, disconnecting the sub-generator 11 of photovoltaic and be first merely able to one pole and carry out, the utmost point with this by the sub-generator 11 of photovoltaic remains on always specifies in potential, for example, with this, prevent the aging of photovoltaic module.In order to be suppressed at the corrosion in thin-film module, need to for example the potential intermediate point of the sub-generator 11 of photovoltaic be moved with respect to earth potential PE.This can realize by the ground connection of one of them bus-bar 31, for example, by GFDI element 35 shown in the figure.The adjustment of the potential on the sub-generator of photovoltaic also can be moved and be realized by alternating current potential on one side alternatively.
The operation of ac short circuit switch 52 prevented large-scale especially electric current from energy resource supply network 70 through transformers 60 with sluggish and therefore (still) closed exchange power zone 40 that disconnecting device 51 flows into central inverter.
The short-circuit conditions being caused on one side by alternating current shows as the mode of operation that can not accept for a long time, because energy resource supply network 70, transformer 60 and short switch 52 are by by being loaded in the short-circuit conditions that can accept for a long time in scope.Yet short-circuit conditions also just arranges provisionally, because exchange opening of disconnecting device 51 in controlling the while or being close to be also accompanied by of ac short circuit switch 52 simultaneously.When interchange disconnecting device 51 has fuse in circuit, the short circuit current automatically circulating by height on this fuse mechanism disconnects.Yet because the fuse of all phases might not all disconnect, be conventionally also provided with in this case a switching mechanism as the parts that exchange disconnecting device 51.Exchange disconnecting device 51 and also alternatively by circuit breaker, form, this circuit breaker under short-circuit conditions automatically or control the full utmost point in ground and disconnect.
Exchanging disconnecting device 51 opened to hundreds of millisecond tens conventionally according to its inherent delay time.In addition, for having connected at ac short circuit switch 52 and having exchanged the time period that disconnecting device 51 is not also opened, by the transmission characteristic limiting short-circuit current of transformer 60.
According to the utility model, be that mechanical switch mechanism based on triggering by semiconductor switch or pyrotechnics can realize short circuit quickly than the disconnection that exchanges wire.Reason is that it is to take mechanical switch as basis that element that be connected and transmitting energy for example exchanges disconnecting device 51, minimum for line loss is down to, and does not wherein generally have the trigger equipment of pyrotechnics.The mechanical switch that requires at the electric current in view of to be connected and voltage must have relative high amount of movement, consider the material inertia of the assembly being connected with common driving mechanism, particularly do not have under the trigger mechanism of pyrotechnics, this relatively high amount of movement has caused above-mentioned intrinsic switching delay.
Another fault can be present in following situation, in two DC wires 20 between the sub-generator 11 of photovoltaic and direct current bonding pad 30, is short-circuited.This short circuit has caused the high electric current at location of short circuit.The electric current of the sub-generator 11 of affected photovoltaic not serious at once wherein, because DC wire 20 arranges for this electric current.Yet more the most important thing is, the sub-generator 11 of all other photovoltaics has been facilitated short circuit current equally through direct current bonding pad 30.In addition,, through the power zone 40 of central inverter, extra short circuit current amount can flow into location of short circuit from energy resource supply network 70.Generally speaking, short circuit current amount can cause the overload of DC wire 20 and produce and catch fire thus, or also can cause overload and/or the destruction of semiconductor switch or fly-wheel diode, for example, at DC-AC current transformer 41 or other, not have to arrange in the element/parts that can bear and transmit so high electric current.Wherein destroying can be the consequence of too high thermal loss, or can be also the consequence of the too high electromagnetic force accompanying with electric current.Similarly, the short circuit producing in a DC-AC current transformer 41 therein by the semiconductor switch that damages for other reasons, electric current that can be by the sub-generator 11 of photovoltaic and cause the destruction of other semiconductor switch from the electric current of energy resource supply network 70.
By the second method of operation, will under this type of short-circuit conditions, protect photovoltaic devices, this short circuit occurs in the region of DC wire 20 or may be in being placed in the region of the boost converter 15 between DC wire and photovoltaic string.Wherein, photovoltaic string 12 disconnects by being placed in the direct current resolution element 14 of generator-near again, and the electric current in DC wire 20 interrupts by the disconnection of other DC insurance silk 32.Wherein direct current resolution element 14 has prevented that electric current from flowing into fault zone from photovoltaic string 12.Here also first disconnect one pole, with this, sub-generator 11 of photovoltaic is remained on and specified in potential.Although other DC insurance silk 32 can bear the short circuit current of the photovoltaic string 12 of the relevant sub-generator 11 of photovoltaic, but can not bear the electric current that may differ in size from the sub-generator 11 of a plurality of incoherent photovoltaics, can not bear the electric current that flows into fault zone through inverter.So above-mentioned electric current can disconnect other DC insurance silk 32 and stop other electric current to flow into fault zone.In inverter, especially due to intermediate loop electric capacity 42, high electric current other DC insurance silk 32 of can flowing through, and DC-AC current transformer 41 can not bear excessive current loading.Thus, intermediate loop electric capacity 42 can contribute to disconnect safely DC insurance silk 32 in the second method of operation.In addition, do not produce obvious electric current and increase in exchanging wire, this electric current increase can cause disconnecting ac short circuit switch 52.Thus, in DC wire 20 regions or in the time of may breaking down, without other method, just can prevent that ac short circuit switch 52 from disconnecting in the region of the boost converter 15 between DC wire and photovoltaic string.
And 52, ac short circuit switch is in the situation that circulate in too high disconnection of electric current in power zone 40, for example, may occur too high electric current by the short circuit in 30Huo power zone, bonding pad 40.For different faults type, carry out the method for operation conform to it, in the long period of operation of photovoltaic devices, also can ensure according to mode and method as far as possible cheaply the reliable protection of photovoltaic devices assembly thus.Especially prevent the unnecessary operations of ac short circuit switch 52, this non-essential operation is connected with expensive with high maintenance cost, because short switch 52 can only use once conventionally, and must change after disconnecting.
In above-mentioned the first and the second method of operation, all must suppress as soon as possible the electric current fault element that sub-generator 11 is connected after flowing into from photovoltaic.In this case, the opening of direct current resolution element 14 that is placed in generator-near may be accompanied by closing of direct-current short circuit switch 16.This be based on, direct-current short circuit switch 16 is semiconductor switchs and reacts soon than the direct current resolution element 14 of slow disconnection.
The third method of operation is specially adapted to process and occurs in the fault in photovoltaic string 12 and the sub-generator of photovoltaic 11 regions.In this case, photovoltaic string 12 may be the parts of boost converter 15 by being placed in the direct-current short circuit switch 16(of generator-near at once) be short-circuited.Then photovoltaic string 12 will disconnect by opening the direct current resolution element 14 and the direct-current short circuit switch 16 that are placed between photovoltaic string 12 and direct-current short circuit switch 16.A this disconnection at present again one pole ground occurs, and the utmost point with this by the sub-generator 11 of photovoltaic always remains on specifies in potential, for example, with this, prevent the aging of photovoltaic module.When breaking down in the region of photovoltaic string 12, according to the connection order of direct-current short circuit switch 16 and direct current resolution element 14, first by photovoltaic string 12 quick no-voltages connect, then, for example, in order to suppress serial arc, photovoltaic string is disconnected.For maintenance and the object of repairing, next also can carry out full utmost point disconnection by two switches 141 and 142 of direct current resolution element 14.When direct-current short circuit switch 16 damages, can advantageously use direct current resolution element 14, be used for stoping lasting short circuit current.
Photovoltaic string 12 and the photovoltaic module being placed in wherein can not transship because of the short circuit producing by direct-current short circuit switch 16, because this direct-current short circuit switch is for short circuit current arranges, and short circuit is expressed as the working point of a permission on its current-voltage characteristic curve.Wherein counterflow-preventing diode 17 has protected photovoltaic module in direct-current short circuit switch 16 and photovoltaic string 12 to avoid high reverse current, the sub-generator 11 of other photovoltaic or 40 flow into direct current bonding pads 30 from power zone otherwise this reverse current can be flowed through.
By application direct-current short circuit switch 16, other DC insurance silk 32 and ac short circuit switch 52, can in direct current bonding pad 30, be omitted in the disconnecting device of available technology adopting, and the rapid connection of the direct-flow input end of the sub-generator 11 of photovoltaic and DC-AC current transformer 41 occurs thus.Especially can omit according to prior art the direct current separating switch on installation position shown in the figure 33 is set, realize thus the saving of material, the extra material consumption bringing due to direct-current short circuit switch 16 and ac short circuit switch 52 that this saving has made up even overcompensation.
In the interchangeable design of photovoltaic devices, can be designed to, ac short circuit switch 52 is placed between the alternating current output and filter 43 of inverter 41.This,, under short-circuit conditions, is exchanged to disconnecting device 51 until open, and the size of short circuit current not only for example, is limited by the transmission performance (stray impedance) of transformer 60, and it is favourable also the transmission performance by filter 43 being obtained to restriction.
Alternatively or extraly can be when settling ac short circuit switch 52 according to diagram, or also in the situation that not having transformer 60 preposition, by the size of inner current limiting element limiting short-circuit current.Yet under excessive current limit, can produce danger, residual electricity fails to be convened for lack of a quorum and flows in inverter.
Compare with exchanging disconnecting device 51, about the arrangement of ac short circuit switch 52, substantially it is noted that and see to energy flow direction when the transmission, exchange disconnecting device 51 be connected on ac short circuit switch 52 after.Arrangement about filter 43 and transformer 60 can change for the consideration of short circuit current size.
Claims (11)
1. a photovoltaic devices that comprises at least one inverter and the sub-generator of at least one photovoltaic (11), described inverter is connected with energy resource supply network (70) by the interchange disconnecting device (51) for delivery of electric power, the sub-generator of described photovoltaic has respectively at least one photovoltaic string (12) and also by the direct current bonding pad (30) of DC wire (20) and at least one inverter, is connected, it is characterized in that
The direct current resolution element (14) of-generator-near, for the direct-current short circuit switch (16) of at least one photovoltaic string (12) of the sub-generator of short circuit photovoltaic (11) and be connected on described direct-current short circuit switch (16) reverse current protection device afterwards along energy flow direction and all distribute to the sub-generator of at least one photovoltaic (11); wherein said direct-current short circuit switch in conveying after energy flow direction is connected on described direct current resolution element, and
-along energy flow direction, exchanging the front ac short circuit switch (52) of having settled of disconnecting device (51).
2. photovoltaic devices according to claim 1, is characterized in that, direct-current short circuit switch (16) is that semiconductor switch and reverse current protection device are counterflow-preventing diode (17).
3. photovoltaic devices according to claim 2, is characterized in that, described semiconductor switch and described counterflow-preventing diode (17) are the assemblies corresponding to the boost converter (15) of the sub-generator of at least one photovoltaic (11).
4. photovoltaic devices according to claim 3, is characterized in that, also has in addition as the inductance (18) of the assembly of boost converter (15) and electric capacity (19) corresponding to the sub-generator of described at least one photovoltaic (11).
5. photovoltaic devices according to claim 1, is characterized in that, described at least one photovoltaic string (12) is furnished with at least one DC insurance silk (13).
6. photovoltaic devices according to claim 1, it is characterized in that, described at least one photovoltaic string (12) has at least another function element, and described another function element is current measuring device, overvoltage semiconductor, leakage switch detector or arc-fault circuit interrupter parts.
7. photovoltaic devices according to claim 1, it is characterized in that, the DC wire (20) that is connected to inverter from the sub-generator of at least one photovoltaic (11) is directly connected with the direct-flow input end of at least one DC-AC current transformer (41) by other DC insurance silk (32) in direct current bonding pad (30), does not wherein arrange and inserts disconnecting device.
8. photovoltaic devices according to claim 1, is characterized in that, ac short circuit switch (52) has at least one semiconductor switch.
9. photovoltaic devices according to claim 1, is characterized in that, the switch motion of ac short circuit switch (52) triggers the method by pyrotechnics.
10. photovoltaic devices according to claim 1, is characterized in that, direct current resolution element (14) has two single-pole switchs that can control separately (141,142).
11. photovoltaic devices according to claim 1, is characterized in that, described photovoltaic devices has the transformer (60) being placed between interchange disconnecting device (51) and energy resource supply network (70).
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE102012110578 | 2012-11-05 | ||
| DE102012110578.2 | 2012-11-05 |
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| Publication Number | Publication Date |
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| CN203722250U true CN203722250U (en) | 2014-07-16 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201320692629.8U Expired - Lifetime CN203722250U (en) | 2012-11-05 | 2013-11-05 | Photovoltaic device |
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| Country | Link |
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| CN (1) | CN203722250U (en) |
| DE (1) | DE102013111869A1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103595014A (en) * | 2013-11-29 | 2014-02-19 | 无锡上能新能源有限公司 | Protective device for photovoltaic power generation system |
| CN104660038A (en) * | 2015-03-09 | 2015-05-27 | 中利腾晖光伏科技有限公司 | Intelligent solar photovoltaic module circuit and control/protection method thereof |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2585173A (en) * | 2018-11-12 | 2021-01-06 | Eaton Intelligent Power Ltd | Photovoltaic string combiner box with protection functions |
| DE102019127198B4 (en) | 2019-10-09 | 2023-01-19 | Sma Solar Technology Ag | METHOD OF OPERATING A POWER GENERATION PLANT AND POWER GENERATION PLANT WITH THE METHOD |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102009038209A1 (en) | 2008-08-21 | 2010-02-25 | Moeller Gmbh | Limiting device for fault currents in an AC low-voltage system |
-
2013
- 2013-10-28 DE DE201310111869 patent/DE102013111869A1/en not_active Withdrawn
- 2013-11-05 CN CN201320692629.8U patent/CN203722250U/en not_active Expired - Lifetime
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103595014A (en) * | 2013-11-29 | 2014-02-19 | 无锡上能新能源有限公司 | Protective device for photovoltaic power generation system |
| CN104660038A (en) * | 2015-03-09 | 2015-05-27 | 中利腾晖光伏科技有限公司 | Intelligent solar photovoltaic module circuit and control/protection method thereof |
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| Publication number | Publication date |
|---|---|
| DE102013111869A1 (en) | 2014-05-08 |
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