CN104113280A - Serial-connection-type photovoltaic square matrix - Google Patents
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Abstract
Disclosed is a serial-connection-type photovoltaic square matrix which is characterized in that the photovoltaic square matrix is formed through serial connection of n photovoltaic string power units, wherein n is larger than 1; and the photovoltaic string power units are formed through serial connection of photovoltaic strings and photovoltaic string high-voltage isolation power control modules. Output ends of the photovoltaic strings are connected with input ends of the photovoltaic string high-voltage isolation power control modules, and via output by DC/DC isolation ports of the photovoltaic string high-voltage isolation power control modules, a withstand voltage of each photovoltaic string power unit is larger than a voltage Usmax of a DC system.
Description
Technical field
The present invention relates to a kind of photovoltaic group string array of solar photovoltaic generation system.
Background technology
Photovoltaic plant develop rapidly under national Policy Encouraging at present, and photovoltaic arrays is one of important composition of photovoltaic generating system, and the square formation amount of capacity being comprised of the connection in series-parallel of photovoltaic group string directly affects the energy output of system.Photovoltaic group string is to be composed in series by some photovoltaic modulies, and assembly is the minimum unit of group string, maximum 22 of series connection quantity, and its reason depends primarily on withstand voltage that assembly bears.Group crosstalk pressure≤1000V power maximum≤7kWp after home and abroad assembly series connection at present.For improving generating merit amount, two kinds of modes are adopted in home and abroad at present: the one, and with the connection in series-parallel of a large amount of photovoltaic group, form square formation in parallel and increase output current, improve square formation power stage in parallel, through inverter inversion, exchanging output, the method is also referred to as centralized or parallel structure, as shown in Figure 4.The 2nd, group serial type photovoltaic generating system as shown in Figure 5, adopt a kind of group of serial type inverter, by the direct input group of many groups group string serial type inverter, first realize the independent MPPT MPPT maximum power point tracking of each photovoltaic group string, at parallel inverter, exchange output afterwards, this type power is less.For further increase power again by many group serial type inverters by the interchange cabinet parallel connection of confluxing.Two types of its essence are all the parallel connections between group string, and voltage is low≤and 1000V, electric current is large, cable machinery loss is large, converging equipment is many, number of cables is many and inverter is the problems such as current mode topological structure power loss is large.Centralized or parallel requirement group string performance parameter is close, cannot from motion tracking, make power loss by the independent maximum power point of realization group string (MPPT) again.Power station, distributed roof area is limit, for meeting respectively to organize when equal installation group string is pressed in crosstalk, must be considered to accept or reject, cause limited area waste.
Have again, limit by the parallel-connection structure of photovoltaic group string, every optical crosstalk volt group connection in series-parallel output voltage is improved according to grid-connected electric pressure, could meet the input starting resistor primary condition of inverter, as in 380v ac grid system, photovoltaic group string output dc voltage >
could meet and start inverter basic operating conditions, starting resistor high to obtain electric weight limited.
Limit by the parallel-connection structure input direct voltage < 1000v of photovoltaic group string, can only meet inverter ac output voltage≤400v hierarchical system transless grid-connected, more voltage levels is grid-connected must be through the transformer output of boosting.
Because inverter or DC equipment are divided into current mode or voltage-type, its feature in power electronic equipment topological structure: the high electric current of voltage-type voltage is little, and loss is little, and current mode voltage low current is large, and loss is large.The same still parallel-connection structure of photovoltaic group string, photovoltaic group string output voltage < 1000v, electric current is large, adopts current mode topological structure inverter.
Thus many groups group string is improved to output voltage in series connection and reduce transmission current increase power, meet more high-grade transless grid-connected, make photovoltaic group string more low-voltage output energy be utilized, reduce cable and converging equipment quantity, adopt voltage-type topological structure inverter or DC equipment, realize and reduce circuit, inverter or DC equipment loss, reduce cable, converging equipment, transformer cost, improve photovoltaic group string generating efficiency, adapt to the demand of distributed, large-sized photovoltaic power station and following middle and high voltage direct current transportation.
The at present photovoltaic system output of boosting has three kinds of modes substantially, one for photovoltaic group connection in series-parallel (square formation in parallel) through confluxing, inverter AC transformer is boosted output, mostly is centralized; Two for the connection in series-parallel of photovoltaic group exchanges and to conflux through the transformer output of boosting again through inverter, mostly is group string data; Three for volt group connection in series-parallel (square formation in parallel) is through confluxing through the DC/DC output of boosting.Its essence still utilizes (parallel square formation) in parallel between a large amount of groups of strings to improve photovoltaic arrays power output.
Summary of the invention
The present invention seeks to overcome method that existing utilization group connection in series-parallel improves generated output and cause the shortcomings such as transmission line, corollary equipment loss be serious, propose a kind of tandem photovoltaic arrays.The present invention utilizes the MPPT photovoltaic group string MPPT maximum power point tracking of photovoltaic group string high pressure isolated power adjustment module, DC/DC, the features such as high pressure isolation (isolation voltage > Usmax), each photovoltaic group was ganged up to photovoltaic group string high pressure isolated power adjustment module and carried out high pressure isolation, improve the isolation voltage grade of each photovoltaic group string, by connecting again between photovoltaic group string high pressure isolated power adjustment module realization group string, improve inverter or DC equipment input voltage, reduce transmission current and increase generated output reduction loss, meet connecting again of different capacity photovoltaic group string power simultaneously, realize photovoltaic DC high-voltage transmission.
The present invention is by the following technical solutions:
Tandem photovoltaic arrays of the present invention is comprised of n photovoltaic group string power unit cascade, n > 1.Photovoltaic group string power cell is composed in series by photovoltaic group string and photovoltaic group string high pressure isolated power adjustment module.
In photovoltaic group string power cell, the output of described photovoltaic group string is connected with the input of photovoltaic group string high pressure isolated power adjustment module, through this photovoltaic group string high pressure isolated power adjustment module DC/DC isolated port, exports.Photovoltaic group string high pressure isolated power adjustment module has a communication interface, for connecting optical fiber or wireless communication module.Output and the communication interface of this photovoltaic group string high pressure isolated power adjustment module are equally also output and the communication interface of photovoltaic group string power cell.Photovoltaic group string is the isolation voltage value of photovoltaic group string power cell through the magnitude of voltage of photovoltaic group string high pressure isolated power adjustment module isolation output.This photovoltaic group string high pressure isolated power adjustment module DC/DC isolated port output voltage U n is also the output voltage values of photovoltaic group string power cell.Due to adding of photovoltaic group string high pressure isolated power adjustment module, make the isolation voltage > Usmax of photovoltaic group string power cell.
Described Usmax is also referred to as direct current system voltage.Usmax=U1max+U2max+U3max ... ,+Unmax, U1max, U2max ..., Unmax is the maximum of each photovoltaic group string power cell output voltage in n photovoltaic group string power cell.Because n photovoltaic group string power unit cascade forms tandem photovoltaic arrays, the output current of its photovoltaic group string power cell is exactly that tandem photovoltaic arrays output current Is is also referred to as direct current system electric current.The direct current importation of direct current system in tandem photovoltaic arrays, DC equipment or inverter forms, and direct current system voltage is the specified DC input voitage of inverter or DC equipment.
Described photovoltaic group string high pressure isolated power adjustment module is comprised of self-supply power source, MPPT photovoltaic group string maximum power point automatic tracking circuit, power conditioning circuitry, communication interface circuit, rectification circuit and high voltage isolating transformer.
The output of photovoltaic group string is connected with the input of photovoltaic group string high pressure isolated power adjustment module.The input of photovoltaic group string high pressure isolated power adjustment module is connected in parallel and is formed by the input of self-supply power source and the input of MPPT photovoltaic group string maximum power point automatic tracking circuit; The output of MPPT photovoltaic group string maximum power point automatic tracking circuit is connected with the input of power conditioning circuitry, the output of power conditioning circuitry is connected with the input of high voltage isolating transformer, the output of high voltage isolating transformer is connected with the input of rectification circuit, the output of rectification circuit is the output of photovoltaic group string high pressure isolated power adjustment module, also be the output of photovoltaic group string power cell, the power output of photovoltaic group string finally, after high voltage isolating transformer electrical isolation, is exported by rectification circuit direct current.The output of self-supply power source is connected with the input of MPPT photovoltaic group string maximum power point automatic tracking circuit, power conditioning circuitry, communication interface circuit power supply respectively, and each circuit work power is provided.Be that a photovoltaic group string output electric weight part provides photovoltaic group string high pressure isolated power adjustment module self power supply needs by self-supply power source, another part is transported to inverter or DC equipment through MPPT photovoltaic group string maximum power point from the circuit such as motion tracking, equipment by a large amount of electric weight.Communication interface circuit is a both-end input and output communication interface circuit, one end of communication interface circuit is connected with power conditioning circuitry communication interface, the other end of communication interface circuit is connected with other photovoltaic group string power cells, inverter or DC equipment by wireless or optical fiber, and the control command of inverter or DC equipment and data and each photovoltaic group string power cell are carried out alternately.
When the power output of photovoltaic group string increases with irradiation intensity, and when meeting the inner self-supply power source of photovoltaic group string high pressure isolated power adjustment module and starting power output, self-supply power source stable output voltage provides working power for all circuit, start the work of photovoltaic group string high pressure isolated power adjustment module, photovoltaic group string high pressure isolated power adjustment module is by its communication interface and inverter or DC equipment communication.MPPT photovoltaic group string maximum power point automatic tracking circuit carries out MPPT maximum power point tracking to photovoltaic group string in real time simultaneously, and by the maximum power input power regulating circuit of tracked photovoltaic group string, power conditioning circuitry coordinates with high voltage isolating transformer photovoltaic group string maximum power is carried out to pwm power adjusting according to photovoltaic group string high pressure isolated power adjustment module control strategy and inverter or DC equipment order, and the maximum power of the photovoltaic group string after regulating is exported by rectification circuit direct current by high voltage isolating transformer electrical isolation.The electrical isolation voltage > direct current system voltage U smax of high voltage isolating transformer, photovoltaic group string now, due to the electrical isolation of high voltage isolating transformer, makes each photovoltaic group string power cell can bear direct current system voltage U smax.
Communication interface circuit in described photovoltaic group string high pressure isolated power adjustment module carries out mutual communication by data such as output voltage U n, the output current Is of photovoltaic group string high pressure isolated power adjustment module, maximum power point power, power adjustments power outputs by wireless or optical fiber and inverter or DC equipment, otherwise the control command of inverter or DC equipment and data are carried out data interaction by this communication interface circuit and each photovoltaic group string power cell.
Described photovoltaic group string is composed in series by n piece photovoltaic module.Photovoltaic module is the minimum generator unit of photovoltaic group string, the series connection quantity of photovoltaic module depends primarily on the voltage that photovoltaic module bears, typical case's photovoltaic group string is composed in series with 20～22 photovoltaic modulies, and the photovoltaic group crosstalk pressure-controlled after series connection is at≤1000V power maximum≤7kWp.
By photovoltaic group string power cell 1, photovoltaic group string power cell 2, photovoltaic group string power cell 3, between the tandem photovoltaic arrays that photovoltaic group string power cell n is composed in series, annexation is: the output negative pole end of photovoltaic group string power cell 1 is connected with the output cathode end of photovoltaic group string power cell 2, the output negative pole end of photovoltaic group string power cell 2 is connected with the output cathode end of photovoltaic group string power cell 3, by that analogy, the output negative pole end of photovoltaic group string power cell n-1 is connected with the output cathode end of photovoltaic group string power cell n, n is positive integer, n>1.The voltage of corresponding photovoltaic group string power cell 1 output is that the voltage of U1,2 outputs of photovoltaic group string power cell is that the voltage that U2, photovoltaic group string power cell 3 are exported is that the voltage that U3, photovoltaic group string power cell n export is Un, all photovoltaic group string power unit cascade electric currents are Is, and series current Is is also tandem photovoltaic arrays output current.The communication interface of photovoltaic group string power cell 1 is connected with the communication interface of photovoltaic group string power cell 2, the like, the communication interface of photovoltaic group string power cell n-1 is connected to the communication interface n of photovoltaic group string power cell n.
The output cathode end of photovoltaic group string power cell 1 is the High voltage output anode of tandem photovoltaic arrays, and the output negative pole end of photovoltaic group string power cell n is the High voltage output negative terminal of tandem photovoltaic arrays.The voltage s of described tandem photovoltaic arrays output is each photovoltaic group string power cell output voltage sum, i.e. voltage s=voltage 1+ voltage 2+ voltage 3 ... voltage n.The power of photovoltaic group string power cell can be not identical, but output current is identical, and photovoltaic group string power cell series quantity can determine according to electrical network, inverter, distributed area requirements.After n photovoltaic group string power cell serial connection, output voltage values is Us, and if each photovoltaic group string power cell output average voltage is 500v, n=20 Us=10000v, far away higher than parallel photovoltaic group string 1000v, improves electric pressure, increases power.
Operation principle of the present invention and the course of work are as follows:
For improving photovoltaic arrays power output, adopting photovoltaic group string series system is ideal means.But due to the highest voltage <1000v that bears of photovoltaic group string, as caused photovoltaic module voltage breakdown to damage series connection between photovoltaic group string, between each photovoltaic group string, increase a high-voltage isolating ring joint for this reason, improve the isolation voltage ability of photovoltaic group string.The present invention ganged up each photovoltaic group with photovoltaic group string high pressure isolated power adjustment module and carries out exporting after high-voltage electrical apparatus isolation, the proof voltage > direct current system voltage U smax that makes each photovoltaic group string power cell, realizes the series connection of n unit photovoltaic group string power cell.
Isolation voltage raising due to photovoltaic group string power cell, the output voltage of n photovoltaic group string power unit cascade connection is tandem photovoltaic arrays output voltage U s, and tandem photovoltaic arrays output voltage U s is each photovoltaic group string power cell output voltage sum: U1+U2+U3+ ... Un=Us.Because the light group string quantity of the photovoltaic module parameter error in each photovoltaic group string power cell or a certain moment irradiation difference or composition is different, make the optimum output voltage Un of each photovoltaic group string power cell after photovoltaic group string high pressure isolated power adjustment module is adjusted likely different, all photovoltaic group string power cell output current Is equate.If when the power of photovoltaic group string power cell output can not meet photovoltaic group string high pressure isolated power adjustment module minimum output power, photovoltaic group string power cell exits output, is output as short-circuit condition.Photovoltaic group string power cell is as follows with the process prescription of inverter or the work of DC equipment cooperation under different situations:
Under normal irradiation, after each photovoltaic group string power cell starts, first real-time tranception inverter or DC equipment communication data output LOW voltage Unmin, output voltage sum U1min+U2min+U3min+ after n unit photovoltaic group string power unit cascade ... Unmin=Usmin, the i.e. minimum output supply power voltage of tandem photovoltaic arrays Usmin.
The minimum output supply power voltage of tandem photovoltaic arrays Usmin is also inverter or DC equipment direct current starting resistor.When Usmin meets inverter or DC equipment startup operating voltage, each photovoltaic group string power cell has monitored electric current output simultaneously.Now the photovoltaic group string high pressure isolated power adjustment module in each photovoltaic group string power cell is calculated photovoltaic group string maximum power point automatically, and to inverter or DC equipment, transmit photovoltaic group string maximum power point data by communication interface, inverter or DC equipment receive after data, analyze all photovoltaic group string high pressure isolated power adjustment module data, and providing each photovoltaic group string power cell optimum voltage value Un and equal output current value Is, each photovoltaic group string power cell is according to this voltage, current value output voltage and electric current.
Along with irradiation intensity increases or reduces, photovoltaic group string power output in each photovoltaic group string power cell synchronously increases or reduces, photovoltaic group string high pressure isolated power adjustment module through this photovoltaic group string power cell detects simultaneously, and to photovoltaic group string MPPT maximum power point tracking.Photovoltaic group string high pressure isolated power adjustment module uploads to through communication interface the photovoltaic group string maximum power point data that detect, calculate in inverter or DC equipment, inverter or DC equipment receive after data, analyze all photovoltaic group string high pressure isolated power adjustment module data, and providing each photovoltaic group string power cell optimum voltage value Un and identical currents value Is, every photovoltaic group string power cell is according to this voltage, current value output voltage and electric current.
When certain photovoltaic group string is subject to obnubilation, dust, fault effects power output reduces, or without irradiation, when photovoltaic group string is output as 0v, MPPT photovoltaic group string maximum power point automatic tracking circuit through the photovoltaic group string high pressure isolated power adjustment module of this photovoltaic group string power cell detects, photovoltaic group string power output can not meet photovoltaic group string high pressure isolated power adjustment module minimum output power, in the time of maybe cannot meeting photovoltaic group string high pressure isolated power adjustment module self-supply power source starting power, photovoltaic group string high pressure isolated power adjustment module quits work, high voltage isolating transformer is through rectification circuit VD 0v, output impedance is 0 Ω, be equivalent to output short-circuit, do not affect other photovoltaic group string power cell power outputs in tandem photovoltaic arrays.Now inverter or DC equipment can not be received the data of this photovoltaic power unit, but inverter or DC equipment still can receive the uploading data of other normal work photovoltaic group string power cell, inverter or DC equipment according to this data analysis are calculated to other photovoltaic group string power cells transmission data, provide photovoltaic group string power cell optimum voltage value Un and equal output current value Is, photovoltaic group string power cell is according to this voltage, current value output voltage and electric current.
Inverter or DC equipment orderly closedown under normal irradiation, or unexpected quitting work, or without communication, or non-loaded or input is when disconnect, photovoltaic group string high pressure isolated power adjustment module Real-Time Monitoring inverter in photovoltaic group string power cell or the communication data of DC equipment and the output current Is of photovoltaic group string power cell, when communication data interrupts or when output current Is is reduced to the operating current lower limit of inverter or DC equipment, photovoltaic group string high pressure isolated power adjustment module responds fast, (<20ms) enters acquiescence safe work state at short notice, export micropower pulse voltage <Unmin, Real-Time Monitoring photovoltaic group string power cell output current Is.When monitoring photovoltaic group string power cell output current Is and reach certain value, illustrate that inverter or DC equipment have accessed to enter startup standby condition, set up communication contact, now photovoltaic group string power cell output voltage U nmin simultaneously.Whether this process accesses tandem photovoltaic arrays or work for detection of inverter or DC equipment.
Starting resistor due to photovoltaic group string power cell timing output micropower pulse voltage <Unmin, tandem photovoltaic arrays output voltage after n photovoltaic group string power unit cascade is very low, be less than voltage sum Usmin after n unit photovoltaic group string power unit cascade, and micropower output current is very little, the fine large electric current of DC high voltage of having avoided draws arc phenomenon, solved the selection issue of high direct voltage General Electric, in other words namely at inverter or DC equipment, normally or surprisingly quit work, or without communication, or non-loaded or input is during off-state, the fast reaction of photovoltaic group string power cell, safe work state is given tacit consent in (<20ms) conversion at short notice, make to organize the pulse of string data photovoltaic arrays output LOW voltage micropower, having solved high direct voltage General Electric is having under loading condition and can be switched on or switched off by the little electric current of low-voltage.
Because each the photovoltaic group string power cell unification of tandem photovoltaic arrays is coordinated and managed by inverter or DC equipment, its photovoltaic group string power can be different, and photovoltaic group string power cell series quantity can be determined according to electrical network, inversion and DC equipment, power station area requirements.Photovoltaic group string is through photovoltaic group string high pressure isolated power adjustment module high pressure isolation output thus, the isolation voltage of photovoltaic group string power cell is improved greatly, so n photovoltaic group string power cell serial connection becomes possibility, improves electric pressure, increased tandem photovoltaic arrays power.
The present invention has the following advantages:
1, tandem photovoltaic arrays can be realized the output of mesohigh direct current, improves photovoltaic array power;
2, high voltage direct current transmission cable loss reduces, and can realize remote long line transmission;
3, tandem photovoltaic arrays, because electric pressure improves, can be realized the transformerless output under this electric pressure, reduces loss, reduces costs.
4, relatively parallel photovoltaic arrays, tandem photovoltaic arrays can be realized the Voltage-output that each photovoltaic group string is lower and start inverter or DC equipment.
5, in tandem photovoltaic arrays, each photovoltaic group string power cell unification is coordinated and managed by contravariant equipment or DC equipment, possesses best power regulation output, can realize the series connection of different capacity photovoltaic group string power cell, solve building roof photovoltaic plant because the different installation component power of roof area is inconsistent and fixed object periodicity blocking assembly, can not installation component problem, make full use of limited space and realize power station generating and maximize.
6, in tandem photovoltaic arrays, abandon converging equipment and greatly reduced failure rate, power loss and cost, in particular for the distributed power station of small-power, provide simple connected mode.
7, owing to adopting modularization thinking to make convenient engineering installation, use reliably.
Accompanying drawing explanation
Fig. 1 is tandem photovoltaic arrays theory diagram;
Fig. 2 is tandem photovoltaic arrays electricity generation system block diagram;
Fig. 3 is that photovoltaic group string high pressure isolated power adjustment module internal circuit connects block diagram;
Fig. 4 is the centralized photovoltaic generating system block diagram of prior art;
Fig. 5 is the group string data photovoltaic generating system block diagram of prior art.
Embodiment
Below in conjunction with the drawings and specific embodiments, further illustrate the present invention.
Tandem photovoltaic arrays of the present invention is comprised of n photovoltaic group string power unit cascade, is respectively: photovoltaic group string power cell 1, photovoltaic group string power cell 2, photovoltaic group string power cell 3 ... photovoltaic group string power cell n.Photovoltaic group string power cell is composed in series by photovoltaic group string and photovoltaic group string high pressure isolated power adjustment module.
The output of described photovoltaic group string is connected with the input of photovoltaic group string high pressure isolated power adjustment module, through this photovoltaic group string high pressure isolated power adjustment module DC/DC isolated port, exports.
In photovoltaic group string power cell, the output Vzn+ of photovoltaic group string, Vzn ﹣ are connected with photovoltaic group string high pressure isolated power adjustment module input Vin+, Vin-respectively, the power of photovoltaic group string output is through this module DC/DC isolation output port Von+, Von ﹣ output, and magnitude of voltage is Un.Due to adding of photovoltaic group string high pressure isolated power adjustment module, make the isolation voltage > Usmax of photovoltaic group string power cell.Each photovoltaic group string high pressure isolated power adjustment module has a communication interface Tn, described communication interface Tn, and the DC/DC of this module isolation output port Von+, Von ﹣ are also communication interface and the output of photovoltaic group string power cell.Equally, the isolation voltage value of photovoltaic group string high pressure isolated power adjustment module is also the isolation voltage value of photovoltaic group string power cell.Communication interface Tn can connect optical fiber or wireless communication module.
Described photovoltaic group string high pressure isolated power adjustment module is comprised of self-supply power source, MPPT photovoltaic group string maximum power point automatic tracking circuit, power conditioning circuitry, communication interface circuit, rectification circuit and high voltage isolating transformer.
The output of photovoltaic group string is connected with the input of photovoltaic group string high pressure isolated power adjustment module.As shown in Figure 3, the input of photovoltaic group string high pressure isolated power adjustment module is composed in parallel by the input of self-supply power source and the input of MPPT photovoltaic group string maximum power point automatic tracking circuit.The output of MPPT photovoltaic group string maximum power point automatic tracking circuit is connected with the input of power conditioning circuitry, the output of power conditioning circuitry is connected with the input of high voltage isolating transformer, the output of high voltage isolating transformer is connected with the input of rectification circuit, the output of rectification circuit is exactly the output of photovoltaic group string high pressure isolated power adjustment module, also be the output of photovoltaic group string power cell, the power output of photovoltaic group string is finally after high voltage isolating transformer electrical isolation, by rectification circuit direct current, exported, realize photovoltaic group string through the DC/DC of photovoltaic group string high pressure isolated power adjustment module isolation output.
The output of self-supply power source respectively with MPPT photovoltaic group string maximum power point automatic tracking circuit, power conditioning circuitry, and the input of communication interface circuit power supply connects, and each circuit work power is provided.
Communication interface circuit is a both-end input and output communication interface circuit, one end of communication interface circuit is connected with power conditioning circuitry communication interface, the other end is also the communication interface of photovoltaic group string power cell, communication interface circuit is connected with other photovoltaic group string power cells, inverter or DC equipment by wireless or optical fiber, and the control command of inverter or DC equipment and data and each photovoltaic group string power cell are carried out alternately.
MPPT photovoltaic group string maximum power point automatic tracking circuit carries out MPPT maximum power point tracking to photovoltaic group string, realizes photovoltaic group string maximum power output.The maximum power output of photovoltaic group string coordinates with high voltage isolating transformer through power conditioning circuitry, according to the order of control strategy and inverter or DC equipment, carries out pwm power adjusting, through high voltage isolating transformer, the output of rectification circuit direct current.The isolation voltage > Usmax of high voltage isolating transformer wherein, this photovoltaic group string and other photovoltaic group were ganged up to high voltage isolating transformer and carried out electrical isolation, so, can make each photovoltaic group string power cell can bear direct current system maximum voltage Usmax.Pwm power adjusting in photovoltaic group string high pressure isolated power adjustment module, output voltage U n, output current Is are carried out communication by communication interface circuit through wireless or optical fiber and other photovoltaic group string power cells, inverter or DC equipment, complete inverter or DC equipment and intercom mutually with tandem photovoltaic arrays.
Described direct current system maximum voltage Usmax=U1max+U2max+U3max ... + Unmax, U1max, U2max ... Unmax is the maximum of each photovoltaic group string power cell output voltage of photovoltaic group string power cell 1, photovoltaic group string power cell 2 to photovoltaic group string power cell n, and every photovoltaic group string high pressure isolated power adjustment module isolation voltage > Usmax.
Described photovoltaic group string is composed in series by some photovoltaic modulies, and the output port of photovoltaic group string is Vzn+, Vzn-.Described photovoltaic module is the minimum generator unit of photovoltaic group string, series connection quantity depends primarily on the voltage that photovoltaic module bears, typical photovoltaic group string adopts 20～22 photovoltaic modulies to be composed in series, and the group crosstalk pressure-controlled after photovoltaic module series connection is at≤1000V power maximum≤7kWp.
The output negative terminal Vo1 ﹣ of photovoltaic group string power cell 1 is connected with photovoltaic group string power cell 2 output plus terminal Vo2+, the output negative terminal Vo2 ﹣ of photovoltaic group string power cell 2 is connected with the output plus terminal Vo3+ of photovoltaic group string power cell 3, by that analogy, the output negative terminal Von-1 ﹣ of photovoltaic group string power cell n-1 is connected with the output plus terminal Von+ of photovoltaic group string power cell n, n is positive integer, n>1.
The output voltage of photovoltaic group string power cell 1 be the output voltage of U1, photovoltaic group string power cell 2 be the output voltage of U2, photovoltaic group string power cell 3 be U3 ..., the output voltage of photovoltaic group string power cell n is Un.Tandem photovoltaic arrays output current is Is, also referred to as system works electric current.
The communication interface T1 of photovoltaic group string power cell 1 is connected with the communication interface T2 of photovoltaic group string power cell 2, the like.The communication interface Tn-1 of photovoltaic group string power cell n-1 is connected to the communication interface Tn of photovoltaic group string power cell n.The output Vo1+ of photovoltaic group string power cell 1 is the High voltage output+end of tandem photovoltaic arrays, the output Von ﹣ of photovoltaic group string power cell n is the High voltage output-end of tandem photovoltaic arrays, its High voltage output+, High voltage output-output voltage values is Us, Us=U1+U2+U3 ... Un.Photovoltaic group string power unit cascade quantity can be according to electrical network, inverter, distributed area requirements.Tandem photovoltaic arrays output voltage values through a plurality of photovoltaic group string power cell serial connections is Us, if each photovoltaic group string power cell output average voltage is 500v, n=20 Us=10000v, far away higher than parallel photovoltaic group string 1000v, has improved electric pressure, has increased power.
Figure 2 shows that the structure of tandem photovoltaic arrays of the present invention.A plurality of photovoltaic modulies form photovoltaic group string, a photovoltaic group string high pressure isolated power adjustment module of the corresponding connection of output of every group of photovoltaic group string.Photovoltaic group string and photovoltaic group string high pressure isolated power adjustment module are composed in series photovoltaic group string power cell.Photovoltaic group string 1 ..., the corresponding photovoltaic group string high pressure isolated power adjustment module 1 that connects of photovoltaic group string n ..., photovoltaic group string high pressure isolated power adjustment module n, organizes string high pressure isolated power regulation output through photovoltaic group string high pressure isolated power adjustment module.The positive pole of photovoltaic group string high pressure isolated power adjustment module 1 is connected with the input anode of inverter or DC equipment, the negative pole of photovoltaic group string high pressure isolated power adjustment module n is connected with the input negative terminal of inverter or DC equipment, form+, the positive and negative DC series formula of ﹣ photovoltaic arrays.
Compare with the group serial type photovoltaic generating system shown in the concentrated photovoltaic generating system shown in Fig. 4, Fig. 5, the advantage of tandem photovoltaic arrays of the present invention is:
1, in the tandem photovoltaic arrays shown in Fig. 2, there is no converging equipment, header box, DC cabinet in concentrated photovoltaic generating system shown in Fig. 4, interchange cabinet in group serial type photovoltaic generating system shown in Fig. 5 all belongs to converging equipment, the quantity of the different configurations of power is different, and converging equipment breaks down in photovoltaic system, rate is high, loss is large.Tandem photovoltaic arrays of the present invention has been abandoned a large amount of converging equipments, reduces the wastage, has reduced cost, improved reliability;
2, in the tandem photovoltaic arrays shown in Fig. 2, photovoltaic group string is connected with photovoltaic group string high pressure isolated power adjustment module nearby, between the photovoltaic group string high pressure isolated power adjustment module of Fig. 2, all by unit cable, be connected in series, output current is a string photovoltaic group crosstalk stream (photovoltaic group string maximum short circuit current < 10A at present).And Fig. 4, in system shown in Fig. 5, converging equipment installation site must be taken into account many group photovoltaic group strings and lay layout, cause n multiple-twin cable in parallel in converging equipment to converging equipment installation site, (Ru16 road header box completes 16 road photovoltaic group connection in series-parallel, number of cables is 16 * 2, its electric current that confluxes is 16 * 10A=160A, n platform group string data inverter exchanges output ac cable parallel connection through n * 4, the after-current that confluxes increases n doubly, and converging equipment again through 2 direct currents or 4 AC great current cables in parallel in upper level converging equipment or inverter, compare the tandem photovoltaic arrays shown in Fig. 2, number of cables increases greatly, and electric current is large, loss, cost increases,
3, tandem photovoltaic arrays shown in Fig. 2, photovoltaic group string can improve inverter or DC equipment input direct voltage by the series connection between photovoltaic group string high pressure isolated power adjustment module, if each photovoltaic group string power cell output average voltage is 500v, 20 photovoltaic group string power cells, inversion, DC equipment input voltage Us=20 * 500v=10000v can be far above Fig. 4, inverter input voltage <1000v shown in Fig. 5, under Same Efficieney condition, make cascaded structure electric current reduce, change parallel heavy-current transmission current mode, reduce the power loss of cable and equipment, and promote photovoltaic arrays power,
4,, in the tandem photovoltaic arrays shown in Fig. 2, photovoltaic group was ganged up series connection between photovoltaic group string high pressure isolated power adjustment module and was improved inverter or DC equipment input direct voltage, can realize lower than input direct voltage/
the grid-connected output of transless, and the photovoltaic generating system shown in Fig. 4, Fig. 5, restriction due to inverter input direct voltage < 1000v, can only meet inverter ac output voltage≤400v system transless grid-connected, more high voltage is grid-connected must transform output through high-tension transformer, and electric current is large, loss is large, cost is high;
5, the tandem photovoltaic arrays in Fig. 2 is positive and negative 2 line direct current outputs, under its equal power output condition, adopt two direct current cabless of many groups in parallel with the centralized photovoltaic generating system of Fig. 4, group string data photovoltaic generating system shown in Fig. 5 adopts many group 3 phase 4 line ac cable output-parallels to compare, cable greatly reduces, and electric current is little, reduce cable loss.The photovoltaic arrays of tandem shown in Fig. 2 structure+, ﹣ direct current output, increased the series connection quantity of photovoltaic group string, improved direct current supply power;
6, in the tandem photovoltaic arrays shown in Fig. 2, it is flexible that photovoltaic group was ganged up photovoltaic group string high pressure isolated power adjustment module output voltage, can make the series connection between photovoltaic group string high pressure isolated power adjustment module under low-voltage condition more of photovoltaic group string improve output dc voltage, meet inversion, DC equipment starting resistor.And the photovoltaic generating system shown in Fig. 4, because the parallel-connection structure of photovoltaic group string is limit, every optical crosstalk volt group connection in series-parallel output voltage is improved according to grid-connected voltage, could meet the input starting resistor primary condition of inverter, as in 380v ac grid system, photovoltaic group string output dc voltage
more than could meet and start inverter work primary condition.
7, inverter or DC equipment are divided into current mode or voltage-type in power electronic equipment topological structure, its feature: the high electric current of voltage-type voltage is little, and loss is little, and current mode voltage low current is large, and loss is large.Tandem photovoltaic arrays shown in Fig. 2 adopts cascaded structure, and inverter or DC equipment input current are little, makes every adjustment module autophage power little of fan heat treatment.The same tandem photovoltaic arrays that adopts, inverter or the high electric current of DC equipment input voltage are little, should adopt voltage-type topological structure inverter or DC equipment power consumption little.And the photovoltaic generating system shown in Fig. 4 is because photovoltaic group string adopts parallel-connection structure, output voltage < 1000v, electric current is large, adopt current mode topological structure inverter, compare voltage-type inversion, DC equipment in the tandem photovoltaic arrays of Fig. 2, power loss is large, and efficiency is low.
Claims (3)
1. a tandem photovoltaic arrays, is characterized in that, described photovoltaic arrays is comprised of n photovoltaic group string power unit cascade, n > 1; Photovoltaic group string power cell is composed in series by photovoltaic group string and photovoltaic group string high pressure isolated power adjustment module; The output of described photovoltaic group string is connected with the input of photovoltaic group string high pressure isolated power adjustment module, through this photovoltaic group string high pressure isolated power adjustment module DC/DC isolated port, exports.
2. according to photovoltaic arrays claimed in claim 1, it is characterized in that, described photovoltaic group string high pressure isolated power adjustment module is comprised of self-supply power source, MPPT photovoltaic group string maximum power point automatic tracking circuit, power conditioning circuitry, communication interface circuit, rectification circuit and high voltage isolating transformer;
The output of photovoltaic group string is connected with the input of photovoltaic group string high pressure isolated power adjustment module; The input of photovoltaic group string high pressure isolated power adjustment module is connected in parallel and is formed by the input of self-supply power source and the input of MPPT photovoltaic group string maximum power point automatic tracking circuit; The output of MPPT photovoltaic group string maximum power point automatic tracking circuit is connected with the input of power conditioning circuitry, the output of power conditioning circuitry is connected with the input of high voltage isolating transformer, the output of high voltage isolating transformer is connected with the input of rectification circuit, the output of rectification circuit is the output of photovoltaic group string high pressure isolated power adjustment module, is also the output of photovoltaic group string power cell; The power output of photovoltaic group string finally, after high voltage isolating transformer electrical isolation, is exported by rectification circuit direct current; The output of self-supply power source respectively with MPPT photovoltaic group string maximum power point automatic tracking circuit, power conditioning circuitry, and the input of communication interface circuit power supply connects, and each circuit work power is provided;
Communication interface circuit is a both-end input and output communication interface circuit, one end of communication interface circuit is connected with power conditioning circuitry communication interface, the other end of communication interface circuit is connected with other photovoltaic group string power cells, inverter or DC equipment by wireless or optical fiber, and the control command of inverter or DC equipment and data and each photovoltaic group string power cell are carried out alternately.
3. according to photovoltaic array claimed in claim 1, it is characterized in that, photovoltaic group described in each was ganged up photovoltaic group string high pressure isolated power adjustment module and was carried out the rear output of high-voltage electrical apparatus isolation, made the proof voltage > direct current system voltage U smax of each photovoltaic group string power cell.
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Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104917394A (en) * | 2015-06-24 | 2015-09-16 | 北京科诺伟业科技股份有限公司 | Serial photovoltaic array high-voltage isolation apparatus |
| CN105207260A (en) * | 2015-09-21 | 2015-12-30 | 北京科诺伟业科技股份有限公司 | Angle-type three-phase alternating-current serial-connection type photovoltaic array |
| CN109634349A (en) * | 2018-12-18 | 2019-04-16 | 珠海格力电器股份有限公司 | Power optimization method and its device, photovoltaic apparatus and photovoltaic system |
| WO2020057635A1 (en) * | 2018-09-21 | 2020-03-26 | 华为技术有限公司 | Photovoltaic power generation inverter system |
| CN111554041A (en) * | 2020-05-12 | 2020-08-18 | 深圳市汇智通咨询有限公司 | Automatic control system of service station |
| CN112332453A (en) * | 2020-11-09 | 2021-02-05 | 上海明华电力科技有限公司 | Photovoltaic string power generation efficiency optimization system |
| CN113036807A (en) * | 2021-04-16 | 2021-06-25 | 阳光电源股份有限公司 | Method and system for reducing series-parallel mismatch loss of photovoltaic set |
| CN113452082A (en) * | 2021-06-17 | 2021-09-28 | 南方电网科学研究院有限责任公司 | Multi-level power control method for string type photovoltaic power station |
| WO2021232691A1 (en) * | 2020-05-20 | 2021-11-25 | 中国华能集团有限公司 | High-voltage photovoltaic power generation system |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2011008348A (en) * | 2009-06-23 | 2011-01-13 | West Holdings Corp | Array and system for generating photovoltaic power |
| CN102355165A (en) * | 2011-09-30 | 2012-02-15 | 浙江大学 | Photovoltaic power generation device with global maximum power output function |
| CN103004070A (en) * | 2010-06-01 | 2013-03-27 | 科罗拉多州立大学董事会法人团体 | Low profile power conversion system for rooftop photovoltaic power systems |
| CN203205449U (en) * | 2013-03-14 | 2013-09-18 | 特变电工新疆新能源股份有限公司 | Solar cell panel array series structure |
| CN103825548A (en) * | 2014-03-05 | 2014-05-28 | 中国华能集团清洁能源技术研究院有限公司 | High-efficiency photovoltaic module and photovoltaic power generation system |
| CN204103855U (en) * | 2014-07-05 | 2015-01-14 | 北京科诺伟业科技股份有限公司 | Tandem photovoltaic square formation |
-
2014
- 2014-07-05 CN CN201410318954.7A patent/CN104113280B/en not_active Expired - Fee Related
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2011008348A (en) * | 2009-06-23 | 2011-01-13 | West Holdings Corp | Array and system for generating photovoltaic power |
| CN103004070A (en) * | 2010-06-01 | 2013-03-27 | 科罗拉多州立大学董事会法人团体 | Low profile power conversion system for rooftop photovoltaic power systems |
| CN102355165A (en) * | 2011-09-30 | 2012-02-15 | 浙江大学 | Photovoltaic power generation device with global maximum power output function |
| CN203205449U (en) * | 2013-03-14 | 2013-09-18 | 特变电工新疆新能源股份有限公司 | Solar cell panel array series structure |
| CN103825548A (en) * | 2014-03-05 | 2014-05-28 | 中国华能集团清洁能源技术研究院有限公司 | High-efficiency photovoltaic module and photovoltaic power generation system |
| CN204103855U (en) * | 2014-07-05 | 2015-01-14 | 北京科诺伟业科技股份有限公司 | Tandem photovoltaic square formation |
Cited By (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104917394A (en) * | 2015-06-24 | 2015-09-16 | 北京科诺伟业科技股份有限公司 | Serial photovoltaic array high-voltage isolation apparatus |
| CN105207260A (en) * | 2015-09-21 | 2015-12-30 | 北京科诺伟业科技股份有限公司 | Angle-type three-phase alternating-current serial-connection type photovoltaic array |
| US11217999B2 (en) | 2018-09-21 | 2022-01-04 | Huawei Technologies Co., Ltd. | Photovoltaic power generation inverter system |
| WO2020057635A1 (en) * | 2018-09-21 | 2020-03-26 | 华为技术有限公司 | Photovoltaic power generation inverter system |
| CN109634349A (en) * | 2018-12-18 | 2019-04-16 | 珠海格力电器股份有限公司 | Power optimization method and its device, photovoltaic apparatus and photovoltaic system |
| US11710969B2 (en) | 2018-12-18 | 2023-07-25 | Gree Electric Appliances, Inc. Of Zhuhai | Power optimization method and apparatus therefor, and photovoltaic device and photovoltaic system |
| CN111554041A (en) * | 2020-05-12 | 2020-08-18 | 深圳市汇智通咨询有限公司 | Automatic control system of service station |
| WO2021232691A1 (en) * | 2020-05-20 | 2021-11-25 | 中国华能集团有限公司 | High-voltage photovoltaic power generation system |
| CN112332453A (en) * | 2020-11-09 | 2021-02-05 | 上海明华电力科技有限公司 | Photovoltaic string power generation efficiency optimization system |
| CN113036807A (en) * | 2021-04-16 | 2021-06-25 | 阳光电源股份有限公司 | Method and system for reducing series-parallel mismatch loss of photovoltaic set |
| CN113036807B (en) * | 2021-04-16 | 2023-08-11 | 阳光电源股份有限公司 | Method and system for reducing series-parallel mismatch loss of photovoltaic group |
| CN113452082A (en) * | 2021-06-17 | 2021-09-28 | 南方电网科学研究院有限责任公司 | Multi-level power control method for string type photovoltaic power station |
| CN113452082B (en) * | 2021-06-17 | 2023-02-28 | 南方电网科学研究院有限责任公司 | Multi-level power control method for string type photovoltaic power station |
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