CN103094923B - Grid-tied power conversion system from direct currents to alternating currents - Google Patents
Grid-tied power conversion system from direct currents to alternating currents Download PDFInfo
- Publication number
- CN103094923B CN103094923B CN201310062485.2A CN201310062485A CN103094923B CN 103094923 B CN103094923 B CN 103094923B CN 201310062485 A CN201310062485 A CN 201310062485A CN 103094923 B CN103094923 B CN 103094923B
- Authority
- CN
- China
- Prior art keywords
- inverter
- module
- grid
- current
- electrical network
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000006243 chemical reaction Methods 0.000 title claims abstract description 36
- 238000012545 processing Methods 0.000 claims abstract description 5
- 238000004891 communication Methods 0.000 claims description 38
- 238000001514 detection method Methods 0.000 claims description 32
- 230000005284 excitation Effects 0.000 claims description 14
- 238000004804 winding Methods 0.000 claims description 9
- 238000005070 sampling Methods 0.000 claims description 3
- 238000013461 design Methods 0.000 abstract description 10
- 238000010304 firing Methods 0.000 abstract 2
- 238000010586 diagram Methods 0.000 description 8
- 241001125929 Trisopterus luscus Species 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 3
- 230000002159 abnormal effect Effects 0.000 description 2
- 230000001186 cumulative effect Effects 0.000 description 2
- 238000005259 measurement Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000005457 optimization Methods 0.000 description 1
Landscapes
- Inverter Devices (AREA)
Abstract
The invention provides a grid-tied power conversion system from direct currents to alternating currents. The system comprises a plurality of inverters and a grid-tied device, wherein the inverters are respectively connected with a plurality of direct current power supplies in a one-to-one correspondence mode, an input end of each inverter is connected with an output end of one corresponding direct current power supply, the output ends of the inverters are mutually connected to form a string, and a zero line of one inverter is connected with a firing wire of the next inverter; and an input end of the grid-tied device is connected with the zero line and the firing wire at two ends of the inverter string, an output end of the grid-tied device is connected with a power grid, and the grid-tied device is used for detecting alternating current output characteristics of the inverter string and alternating current characteristics of the power grid and processing data and controlling the inverters after various power parameters of the inverter string and the power grid and parameters which can be calculated correspondingly are obtained. The system can simplify the design of the inverters in the system, improves conversion efficiency of the inverters, reduces cost of the inverters, and improves reliability.
Description
Technical field
The present invention relates to direct current to the switch technology field exchanged, specifically, the present invention relates to a kind of direct current to the grid-connected electric power coversion system exchanged.
Background technology
In field of renewable energy, such as photovoltaic and wind energy, have use micro-inverter to be converted to by the direct current power of each power supply can the alternating electromotive force of grid-connected output, and each power supply is carried out to the optimization of electric power output, such as MPPT maximum power point tracking (MPPT) etc.
Fig. 1 is the modular structure schematic diagram that a kind of micro-inverter system of the prior art connects DC power supply and electrical network.As shown in Figure 1, this micro-inverter system comprise multiple respectively with single DC power supply 101
1, 101
2... 101
nthe inverter 102 connected
1, 102
2... 102
n.Each inverter 102
1, 102
2... 102
ninput and each DC power supply 101
1, 101
2... 101
noutput correspondence connect, each inverter 102
1, 102
2... 102
noutput-parallel, namely each inverter 102
1, 102
2... 102
nlive wire L103 be connected, zero line N104 be connected, then connect electrical network 105.Be exactly each inverter 102 like this
1, 102
2... 102
nby DC power supply 101
1, 101
2... 101
ndirectly be converted to the alternating current identical with electrical network 105.But so micro-inverter system has following point:
1. inverter design is complicated.Direct voltage is converted to alternating current by single inverter and carries out grid-connected by prior art, for avoiding the quality affecting electrical network, very high to the quality requirement of AC wave shape; For system safety, also require to possess perfect defencive function.
2. low efficiency.Conventional DC power supply, the voltage as photovoltaic module, battery etc. is tens volts, and the peak value of grid alternating current is generally more than 380V, so just needs the multiple of dc voltage boost very high, causes very low conversion efficiency.
3. high cost.Except power conversion circuit, each inverter also needs other various circuit to ensure grid-connected quality, to realize grid-connected protection, EMC, communication etc., causes too high cost.
4. low reliability.The AC of each inverter is grid-connected voltage, and voltage is high, large to the stress of various power device, and directly connects electrical network, is easily subject to the impact of electrical network anomaly, thus causes damage.
Summary of the invention
Technical problem to be solved by this invention is to provide a kind of direct current to the grid-connected electric power coversion system exchanged, and can simplify the design of inverter, improves the efficiency of inverter, reduces the cost of inverter and promotes reliability.
For solving the problems of the technologies described above, the invention provides a kind of direct current to the grid-connected electric power coversion system exchanged, comprising:
Multiple inverter, connect one to one with multiple DC power supply respectively, the input of described inverter is connected with the output of described DC power supply, and the output of inverter described in each is connected to each other bunchiness, and the zero line of previous inverter is connected with the live wire of a rear inverter;
And wire stitcher, its input is connected with zero line with the live wire at inverter string two ends respectively, its output is connected with electrical network, described and wire stitcher is for detecting the interchange output characteristic of described inverter string and detecting the AC characteristic of described electrical network, after the various electrical energy parameter obtaining described inverter string and described electrical network and the parameter that should be able to calculate mutually thereof, data are processed and described inverter is controlled.
Alternatively, described inverter comprises:
DC detecting module, is connected with the direct-flow input end of described inverter, for detecting the DC input voitage and direct current input current that input described inverter;
Power conversion circuit, is connected with ac output end with the direct-flow input end of described inverter respectively, for direct current is converted to alternating current;
Conversion and control module, is connected with described power conversion circuit with described DC detecting module respectively, for generation of with send to described power conversion circuit one drive singal, to realize the alternating current wanted;
First communication module, external and described and wire stitcher is connected, and for obtaining data and the command signal of needs, or the data of described inverter is sent to described also wire stitcher or other communication equipment;
Alternating-current parameter acquisition module, is connected with described conversion and control module with described first communication module respectively, for obtaining by data that are described and wire stitcher acquisition, carrying out the alternating-current parameter calculating to obtain needs, being supplied to described conversion and control module.
Alternatively, described inverter also comprises:
Exchange detection module, being connected with described conversion and control module with the ac output end of described inverter respectively, for detecting the ac output voltage and ac output current that export described inverter, and feeding back to described conversion and control module.
Alternatively, described and wire stitcher comprises:
Inverter detection module, for detecting the interchange output characteristic of described inverter string;
Electrical net detect module, for detecting the AC characteristic of described electrical network;
Grid-connected protection module, for realizing the function of electric network protection;
Inverter communication module, for communicating with multiple described inverter, collecting the data of described inverter or sending control command to described inverter;
System control module; be connected with inverter communication module with described inverter detection module, electrical net detect module, grid-connected protection module respectively; for carrying out data processing according to the interchange output characteristic of described inverter string, the AC characteristic of described electrical network, and produce to described inverter and/or to various control commands that are described and the above-mentioned internal module of wire stitcher.
Alternatively, described and wire stitcher also comprises:
Correspondence with foreign country module, for communicating with other equipment outside, to transmit data and control command;
Wherein, other equipment of described outside comprise computer, internet router and mobile phone.
Alternatively, the interchange output characteristic of described inverter string comprises the parameter that electric current, voltage, frequency, phase place, zero crossing and phase thereof should be able to calculate;
Wherein, the described parameter that should be able to calculate mutually comprises current effective value, active power, reactive power and power factor.
Alternatively, the AC characteristic of described electrical network comprises voltage, frequency and phase place.
Alternatively, described inverter comprises:
Decoupling capacitance, is connected across the two ends of described DC power supply;
Circuit of reversed excitation, it comprises former limit switching tube, transformer and flyback diode, and the former limit winding of described transformer is connected with described DC power supply;
Power frequency full bridge inverter, be connected with described electrical network with the vice-side winding of the described transformer of described circuit of reversed excitation respectively, it comprises the full bridge structure be made up of four switching tubes;
DC detection circuit, is connected with the output of described DC power supply, for detecting the DC input voitage and direct current input current that input described inverter;
Second communication module, external and described and wire stitcher is connected, and for obtaining data and the command signal of needs, or the data of described inverter is sent to described also wire stitcher or other communication equipment;
Full-bridge control module, is connected with described power frequency full bridge inverter with described second communication module respectively, and the described switching tube for the full bridge structure to described power frequency full bridge inverter controls;
Reference current computing module, be connected with described second communication module with described DC detection circuit respectively, for calculating acquisition reference current according to the phase place of DC input voitage value, ac output voltage value, ac output current value, ac output voltage and time;
Flyback control circuit, be connected with the grid of the former limit winding of described reference current computing module, described transformer with the former limit switching tube of described circuit of reversed excitation respectively, for sampling primary current contrasting with described reference current, produce the drive singal that flyback controls.
Alternatively, described electrical network and described inverter are single-phase electrical network and inverter, or are the two-phase electrical network with 1 zero line and 2 live wires and inverter, or are the three phase network with 1 zero line and 3 live wires and inverter.
Compared with prior art, the present invention has following characteristics and advantage:
1. simplify the design of inverter.Prior art is that DC input voitage is converted to grid-connected alternating voltage, and the present invention forms synchronization AC voltage by the ac output voltage of a string inverter is cumulative, can simplify the design of inverter.
2. improve the efficiency of inverter.Reduce the ac output voltage of inverter to the output voltage close to DC power supply, conversion coefficient is little, can improve conversion efficiency.
3. reduce the cost of inverter.The ac output voltage reducing inverter, to the output voltage close to DC power supply, can adopt low voltage component, reduce costs thus.Also the circuit modules such as grid-connected protection, communication focused in addition and in wire stitcher, simplify cable, reduce costs.
4. improve the reliability of inverter.Reduce the voltage stress of power device, also reduce the abnormal damage possible to inverter of electrical network.
In sum, contrast with existing Miniature inverter, the present invention has all advantages of Miniature inverter system, only need direct current to be converted to the close alternating current of voltage, and do not need to boost to identical with line voltage, thus simplify inverter design, improve conversion efficiency, reduce the cost of inverter, improve the reliability of inverter.
Accompanying drawing explanation
The above and other features of the present invention, character and advantage become more obvious by passing through below in conjunction with the description of drawings and Examples, wherein:
Fig. 1 is the modular structure schematic diagram that a kind of micro-inverter system of the prior art connects DC power supply and electrical network;
Fig. 2 is the grid-connected electric power coversion system connection DC power supply of direct current to interchange and the modular structure schematic diagram of electrical network of one embodiment of the invention;
Fig. 3 is the internal module structural representation of direct current to inverter in the grid-connected electric power coversion system exchanged of one embodiment of the invention;
Fig. 4 is that the direct current of one embodiment of the invention is in the grid-connected electric power coversion system exchanged and the internal module structural representation of wire stitcher;
Fig. 5 is the inside ball bearing made using schematic diagram of the grid-connected back exciting converter of a connection DC power supply of the prior art and electrical network;
Fig. 6 is the inside ball bearing made using schematic diagram of the grid-connected back exciting converter in the connection DC power supply of one embodiment of the invention and the grid-connected electric power coversion system of electrical network.
Embodiment
Below in conjunction with specific embodiments and the drawings, the invention will be further described; set forth more details in the following description so that fully understand the present invention; but the present invention obviously can implement with multiple this alternate manner described that is different from; those skilled in the art can when doing similar popularization, deduction without prejudice to when intension of the present invention according to practical situations, therefore should with content constraints protection scope of the present invention of this specific embodiment.
Fig. 2 is the grid-connected electric power coversion system connection DC power supply of direct current to interchange and the modular structure schematic diagram of electrical network of one embodiment of the invention.It should be noted that this and follow-up other accompanying drawing all only exemplarily, it is not draw according to the condition of equal proportion, and should not be construed as limiting in this, as to the protection range of actual requirement of the present invention.As shown in Figure 2, this direct current mainly comprises multiple inverter 202 and one and wire stitcher 203 to the grid-connected electric power coversion system exchanged.Wherein, multiple inverter 202
1, 202
2... 202
i... 202
n(describing easy for asking, unified being designated as 202) respectively with multiple DC power supply 201
1, 201
2... 201
i... 201
n(for asking description easy, unification is designated as 201) connects one to one.The input of inverter 202 is connected with the output of DC power supply 201, and the output of each inverter 202 is connected to each other bunchiness, and the zero line N of previous inverter is connected with the live wire L of a rear inverter.And the input of wire stitcher 203 is connected with zero line N206 with the live wire L205 at inverter string two ends respectively, output is connected with electrical network 208.And wire stitcher 203 is for the AC characteristic of the interchange output characteristic and detection of grid 208 that detect inverter string, after the parameter that the various electrical energy parameter of acquisition inverter string and electrical network 208 and phase thereof should be able to calculate, data are processed and inverter 202 is controlled.
Due to and the output of wire stitcher 203 directly connects electrical network 208, so total ac output voltage Vout equals line voltage Vgrid.And wire stitcher 203 detection of grid voltage and the ac output current Iout that passes through.Each inverter 202
idC input voitage be designated as Vdci, direct current input current is designated as Idci, and DC input power is designated as Pdci, and ac output voltage effective value is designated as Vaci, and ac output current effective value is designated as Iaci, and output AC power is designated as Paci.And total output AC power of a string inverter (inverter string) is designated as Pout, ac output voltage is designated as Vout, and ac output current is designated as Iout.
For multiple inverter i=2 ~ N (N be greater than 2 natural number), after each inverter detects DC input voitage Vdci and direct current input current Idci, being multiplied to calculate obtains DC input power Pdci.Suppose that the efficiency that energy is transferred to AC by DC side is κ, the power output P of so each inverter
i=κ × P
dci, κ be about 1 a parameter.Be exactly total the summation of the output AC power Pout Pi of a string inverter.Total ac output voltage Vout of a string inverter equals line voltage Vgrid.Because the output of these inverters is connected, the electric current I aci of this string inverter is equal everywhere, for Iout equals Pout/Vout.The ac output voltage Vaci of each inverter equals Pi/Iaci.
The computing formula of all power of the above-mentioned single inverter 202i that applies to or whole inverter string, electric current and voltage is unified conclusion and is described below:
P
dci＝V
dci×I
dci
P
aci＝κ×P
dci
P
out＝∑P
aci＝∑κ×P
dci＝κ×∑V
dci×I
dci
V
out＝V
grid
I
out＝P
out/V
out
I
aci＝I
out＝P
out/V
out＝κ×(ΣV
dci×I
dci)/V
rgid
V
aci＝P
aci/I
aci＝P
aci/I
out
Fig. 3 is the internal module structural representation of direct current to inverter in the grid-connected electric power coversion system exchanged of one embodiment of the invention.As shown in Figure 3, this inverter 400 mainly comprises DC detecting module 403, power conversion circuit 405, conversion and control module 407, alternating-current parameter acquisition module 409 and first communication module 411.Wherein, DC detecting module 403 is connected with the direct-flow input end of inverter 400, for detecting DC input voitage and the direct current input current of input inverter 400.Power conversion circuit 405 is connected with ac output end with the direct-flow input end of inverter 400 respectively, for direct current is converted to alternating current.Conversion and control module 407 is connected with power conversion circuit 405 with DC detecting module 403 respectively, for generation of with send to power conversion circuit 405 1 drive singal, to realize the alternating current wanted.First communication module 411 externally with and wire stitcher 203 be connected, for obtaining data and the command signal of needs, or the data of inverter 400 are sent to also wire stitcher 203 or other communication equipment.Alternating-current parameter acquisition module 409 is connected with conversion and control module 407 with first communication module 411 respectively, for obtain by and the data that obtain of wire stitcher 203, carry out the alternating-current parameter calculating to obtain needs, be supplied to conversion and control module 407.
In the present embodiment, this inverter 400 can also comprise interchange detection module 413, it is connected with conversion and control module 407 with the ac output end of inverter 400 respectively, for detecting ac output voltage and the ac output current of output inverter 400, and feeds back to conversion and control module 407.
Fig. 4 is that the direct current of one embodiment of the invention is in the grid-connected electric power coversion system exchanged and the internal module structural representation of wire stitcher.As shown in Figure 4, also inverter detection module 503, electrical net detect module 505, grid-connected protection module 507, inverter communication module 509 and system control module 511 should mainly be comprised by wire stitcher 500.Wherein, inverter detection module 503, for detecting the interchange output characteristic of inverter string 501, comprises various electrical energy parameter, as electric current, voltage, frequency, phase place, zero crossing etc., and the corresponding parameter calculated, as current effective value, active power, reactive power and power factor etc.Electrical net detect module 505, for the AC characteristic of detection of grid 502, comprises various electrical energy parameter, as voltage, frequency and phase place etc.Grid-connected protection module 507, for realizing the function of electric network protection, when line voltage, frequency exceed the protection range of setting, or during grid power blackout, drives and the connection of wire stitcher 500 shutoff and electrical network.Inverter communication module 509, for communicating with multiple inverter 202, is collected the data of inverter 202 or sends control command to inverter 202.System control module 511 is connected with inverter communication module 509 with inverter detection module 503, electrical net detect module 505, grid-connected protection module 507 respectively; for carrying out data processing according to the interchange output characteristic of inverter string 501, the AC characteristic of electrical network 502, and produce to inverter 202 and/or to and the various control commands of above-mentioned internal module of wire stitcher 500.
In the present embodiment, also should can also comprise correspondence with foreign country module 513 by wire stitcher 500, for communicating with other equipment outside, to transmit data and control command.Wherein, other equipment outside can comprise computer, internet router and mobile phone.
Fig. 5 is the inside ball bearing made using schematic diagram of the grid-connected back exciting converter of a connection DC power supply of the prior art and electrical network.As shown in Figure 5, this inverter 600 is connected with the electrical network 602 on right side with the DC power supply 601 in left side respectively.In Fig. 5, inverter 600 is made up of decoupling capacitance Cin, circuit of reversed excitation 604 and power frequency full bridge inverter 606.Wherein, circuit of reversed excitation 604 is primarily of former limit switching tube S
m1, transformer T
1and flyback diode D
1composition.Parallel network reverse 606 comprises by four switching tube S
aC1~ S
aC4the full bridge structure of composition.The output of flyback converter is by switching tube S
aC1~ S
aC4control decide.Former limit switching tube S in circuit of reversed excitation 604
m1the drive singal controlled by flyback controls, and the drive singal that flyback controls contrasts generation by flyback control circuit through primary current and reference current.Reference current is obtained by DC voltage value, ac voltage, AC current values, AC phases and Time Calculation.In prior art, AC detection circuit detects the interchange output of inverter 600, obtains the parameter needed, is supplied to reference current computing module.In addition, the AC signal that AC detection circuit detects also sends to full-bridge control module, for the control of each switching tube of full bridge structure.
The computing formula of reference current can be write a Chinese character in simplified form as follows:
I
ref＝function(V
dc，ω，t，I
ac，V
ac)
Wherein, Iref is the reference current of each time point, and Vdc is DC input voitage, and Vac is the effective value of ac output voltage, and Iac is the effective value of ac output current, and ω is the phase place of ac output voltage, and t is the time in one-period.After obtaining these parameters, reference current computing module, according to above-mentioned formula, can calculate the reference current value Iref of each time point t easily.
Fig. 6 is the inside ball bearing made using schematic diagram of the grid-connected back exciting converter in the connection DC power supply of one embodiment of the invention and the grid-connected electric power coversion system of electrical network.As shown in Figure 6, this inverter 600 mainly comprises decoupling capacitance Cin, circuit of reversed excitation 604, power frequency full bridge inverter 606, DC detection circuit, full-bridge control module, reference current computing module, flyback control circuit and second communication module.Wherein, decoupling capacitance Cin is connected across the two ends of DC power supply 601.Circuit of reversed excitation 604 comprises former limit switching tube S
m1, transformer T
1with flyback diode D
1, transformer T
1former limit winding be connected with DC power supply 601.Power frequency full bridge inverter 606 respectively with the transformer T of circuit of reversed excitation 604
1vice-side winding be connected with electrical network 602, it comprises by four switching tube S
aC1~ S
aC4the full bridge structure of composition.DC detection circuit is connected with the output of DC power supply 601, for detecting DC input voitage and the direct current input current of input inverter 600.Second communication module externally with and wire stitcher 603 be connected, for obtaining data and the command signal of needs, or the data of inverter 600 are sent to also wire stitcher 603 or other communication equipment.Full-bridge control module is connected with power frequency full bridge inverter 606 with second communication module respectively, for the switching tube S of the full bridge structure to power frequency full bridge inverter 606
aC1~ S
aC4control.Reference current computing module is connected with second communication module with DC detection circuit respectively, for calculating acquisition reference current according to the phase place of DC input voitage value, ac output voltage value, ac output current value, ac output voltage and time.Flyback control circuit respectively with reference current computing module, transformer T
1former limit winding and the former limit switching tube S of circuit of reversed excitation 604
m1grid be connected, for sampling primary current contrasting with reference current, produce the drive singal that flyback controls.
Visible, in the present embodiment, and above-mentioned prior art is unlike not having AC detection circuit, but by second communication module from and wire stitcher 603 obtain alternating-current parameter, and send to reference current calculate need and full-bridge control.The calculating of reference current remains and adopts formula below:
I
ref＝function(V
dc，ω，t，I
ac，V
ac)
Wherein, Iref is the reference current of each time point, and Vdc is DC input voitage, and Vac is the effective value of ac output voltage, and Iac is the effective value of ac output current, and ω is the phase place of ac output voltage, and t is the time in one-period.After obtaining these parameters, reference current computing module, according to above-mentioned formula, can calculate the reference current value Iref of each time point t easily.
In above-mentioned parameters, obtain following signal by DC detection circuit: the DC input voitage Vdc that input voltage measurement part wherein provides, the direct current input current Idc that input electric cur-rent measure part provides.
By and wire stitcher obtain following signal: the ac output voltage effective value Vac of each inverter, the ac output current effective value Iac of each inverter, the phase place ω of ac output voltage, the zero crossing of ac output voltage.For multiple inverter i=2 ~ N (N be greater than 2 natural number), after each inverter detects DC input voitage Vdci and direct current input current Idci, being multiplied to calculate obtains direct current incoming frequency Pdci.Then this power is sent to and wire stitcher 603 by second communication module by each inverter.And wire stitcher 603 calculates acquisition output AC power Pout the DC input power Pdci sent by all inverters in a string inverter of correspondence.And the effective value Vgrid of wire stitcher 603 detection of grid voltage, and total ac output voltage Vout that the design of wire stitcher 603 is a string inverters equals the Vgrid of electrical network 602.And after wire stitcher 603 calculates Iout=Pout/Vgrid, these data are issued all inverters by the second communication module of inverter 600.Output AC power due to each inverter is Pac, and ac output current is Iac=Iout, so it is Vac=Pi/Iout that each inverter just can calculate acquisition ac output voltage.
In such reference current Iref, all parameters have had, and are easy to calculate reference current Iref, for electric power conversion and control.
It is for circuit of reversed excitation and power frequency full bridge inverter structure that the main body of above-mentioned inverter is formed, but also can be other topology.
In addition, the electrical network 208 in above-described embodiment and inverter 202 for single-phase electrical network and inverter, but also can be other electrical network and inverter, and such as two-phase has 1 zero line and 2 live wires; Or three-phase, has 1 zero line and 3 live wires.
Compared with prior art, the present invention has following characteristics and advantage:
1. simplify the design of inverter.Prior art is that DC input voitage is converted to grid-connected alternating voltage, and the present invention forms synchronization AC voltage by the ac output voltage of a string inverter is cumulative, can simplify the design of inverter.
2. improve the efficiency of inverter.Reduce the ac output voltage of inverter to the output voltage close to DC power supply, conversion coefficient is little, can improve conversion efficiency.
3. reduce the cost of inverter.The ac output voltage reducing inverter, to the output voltage close to DC power supply, can adopt low voltage component, reduce costs thus.Also the circuit modules such as grid-connected protection, communication focused in addition and in wire stitcher, simplify cable, reduce costs.
4. improve the reliability of inverter.Reduce the voltage stress of power device, also reduce the abnormal damage possible to inverter of electrical network.
In sum, contrast with existing Miniature inverter, the present invention has all advantages of Miniature inverter system, only need direct current to be converted to the close alternating current of voltage, and do not need to boost to identical with line voltage, thus simplify inverter design, improve conversion efficiency, reduce the cost of inverter, improve the reliability of inverter.
Although the present invention with preferred embodiment openly as above, it is not that any those skilled in the art without departing from the spirit and scope of the present invention, can make possible variation and amendment for limiting the present invention.Therefore, every content not departing from technical solution of the present invention, any amendment done above embodiment according to technical spirit of the present invention, equivalent variations and modification, all fall within protection range that the claims in the present invention define.
Claims (10)
1. direct current is to the grid-connected electric power coversion system exchanged, and comprising:
Multiple inverter, connect one to one with multiple DC power supply respectively, the input of described inverter is connected with the output of described DC power supply, and the output of inverter described in each is connected to each other bunchiness, and the zero line of previous inverter is connected with the live wire of a rear inverter; And
And wire stitcher, its input is connected with zero line with the live wire at inverter string two ends respectively, its output is connected with electrical network, described and wire stitcher is for detecting the interchange output characteristic of described inverter string and detecting the AC characteristic of described electrical network, after the various electrical energy parameter obtaining described inverter string and described electrical network and the parameter that should be able to calculate mutually thereof, data are processed and described inverter is controlled;
Wherein, described and wire stitcher comprises:
Inverter detection module, for detecting the interchange output characteristic of described inverter string;
Electrical net detect module, for detecting the AC characteristic of described electrical network;
Grid-connected protection module, for realizing the function of electric network protection;
Inverter communication module, for communicating with multiple described inverter, collecting the data of described inverter or sending control command to described inverter; And
System control module, be connected with inverter communication module with described inverter detection module, electrical net detect module, grid-connected protection module respectively, for carrying out data processing according to the interchange output characteristic of described inverter string, the AC characteristic of described electrical network, and produce to described inverter and/or to various control commands that are described and the above-mentioned internal module of wire stitcher;
And described inverter comprises:
DC detecting module, is connected with the direct-flow input end of described inverter, for detecting the DC input voitage and direct current input current that input described inverter;
Power conversion circuit, is connected with ac output end with the direct-flow input end of described inverter respectively, for direct current is converted to alternating current;
Conversion and control module, is connected with described power conversion circuit with described DC detecting module respectively, for producing in described inverter oneself inside and send to described power conversion circuit one drive singal, to realize the alternating current wanted;
Communication module, external and described and wire stitcher is connected, and for obtaining data and the command signal of needs, or the data of described inverter is sent to described also wire stitcher or other communication equipment; And
Alternating-current parameter acquisition module, is connected with described conversion and control module with described communication module respectively, for obtaining by data that are described and wire stitcher acquisition, carrying out the alternating-current parameter calculating to obtain needs, being supplied to described conversion and control module;
Wherein, what do not comprise the ac output voltage that exports described inverter for direct-detection and ac output current in described inverter exchanges detection module or AC detection circuit.
2. grid-connected electric power coversion system according to claim 1, is characterized in that, described and wire stitcher also comprises:
Correspondence with foreign country module, for communicating with other equipment outside, to transmit data and control command;
Wherein, other equipment of described outside comprise computer, internet router and mobile phone.
3. grid-connected electric power coversion system according to claim 1 and 2, is characterized in that, the parameter that the interchange output characteristic of described inverter string comprises electric current, voltage, frequency, phase place, zero crossing and should be able to calculate mutually;
Wherein, the described parameter that should be able to calculate mutually comprises current effective value, active power, reactive power and power factor.
4. grid-connected electric power coversion system according to claim 1 and 2, is characterized in that, the AC characteristic of described electrical network comprises voltage, frequency and phase place.
5. grid-connected electric power coversion system according to claim 1, it is characterized in that, described electrical network and described inverter are single-phase electrical network and inverter, or be the two-phase electrical network with 1 zero line and 2 live wires and inverter, or be the three phase network with 1 zero line and 3 live wires and inverter.
6. direct current is to the grid-connected electric power coversion system exchanged, and comprising:
Multiple inverter, connect one to one with multiple DC power supply respectively, the input of described inverter is connected with the output of described DC power supply, and the output of inverter described in each is connected to each other bunchiness, and the zero line of previous inverter is connected with the live wire of a rear inverter; And
And wire stitcher, its input is connected with zero line with the live wire at inverter string two ends respectively, its output is connected with electrical network, described and wire stitcher is for detecting the interchange output characteristic of described inverter string and detecting the AC characteristic of described electrical network, after the various electrical energy parameter obtaining described inverter string and described electrical network and the parameter that should be able to calculate mutually thereof, data are processed and described inverter is controlled;
Wherein, described and wire stitcher comprises:
Inverter detection module, for detecting the interchange output characteristic of described inverter string;
Electrical net detect module, for detecting the AC characteristic of described electrical network;
Grid-connected protection module, for realizing the function of electric network protection;
Inverter communication module, for communicating with multiple described inverter, collecting the data of described inverter or sending control command to described inverter; And
System control module, be connected with inverter communication module with described inverter detection module, electrical net detect module, grid-connected protection module respectively, for carrying out data processing according to the interchange output characteristic of described inverter string, the AC characteristic of described electrical network, and produce to described inverter and/or to various control commands that are described and the above-mentioned internal module of wire stitcher;
And described inverter comprises:
Decoupling capacitance, is connected across the two ends of described DC power supply;
Circuit of reversed excitation, it comprises former limit switching tube, transformer and flyback diode, and the former limit winding of described transformer is connected with described DC power supply;
Power frequency full bridge inverter, be connected with described electrical network with the vice-side winding of the described transformer of described circuit of reversed excitation respectively, it comprises the full bridge structure be made up of four switching tubes;
DC detection circuit, is connected with the output of described DC power supply, for detecting the DC input voitage and direct current input current that input described inverter;
Communication module, external and described and wire stitcher is connected, and for obtaining data and the command signal of needs, or the data of described inverter is sent to described also wire stitcher or other communication equipment;
Full-bridge control module, is connected with described power frequency full bridge inverter with described communication module respectively, and the described switching tube for the full bridge structure to described power frequency full bridge inverter controls;
Reference current computing module, be connected with described communication module with described DC detection circuit respectively, for calculating acquisition reference current according to the phase place of DC input voitage value, ac output voltage value, ac output current value, ac output voltage and time; And
Flyback control circuit, be connected with the grid of the former limit winding of described reference current computing module, described transformer with the former limit switching tube of described circuit of reversed excitation respectively, for sampling primary current contrasting with described reference current, produce the drive singal that flyback controls in described inverter oneself inside;
Wherein, what do not comprise the ac output voltage that exports described inverter for direct-detection and ac output current in described inverter exchanges detection module or AC detection circuit.
7. grid-connected electric power coversion system according to claim 6, is characterized in that, described and wire stitcher also comprises:
Correspondence with foreign country module, for communicating with other equipment outside, to transmit data and control command;
Wherein, other equipment of described outside comprise computer, internet router and mobile phone.
8. the grid-connected electric power coversion system according to claim 6 or 7, is characterized in that, the parameter that the interchange output characteristic of described inverter string comprises electric current, voltage, frequency, phase place, zero crossing and should be able to calculate mutually;
Wherein, the described parameter that should be able to calculate mutually comprises current effective value, active power, reactive power and power factor.
9. the grid-connected electric power coversion system according to claim 6 or 7, is characterized in that, the AC characteristic of described electrical network comprises voltage, frequency and phase place.
10. grid-connected electric power coversion system according to claim 6, it is characterized in that, described electrical network and described inverter are single-phase electrical network and inverter, or be the two-phase electrical network with 1 zero line and 2 live wires and inverter, or be the three phase network with 1 zero line and 3 live wires and inverter.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310062485.2A CN103094923B (en) | 2013-02-27 | 2013-02-27 | Grid-tied power conversion system from direct currents to alternating currents |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310062485.2A CN103094923B (en) | 2013-02-27 | 2013-02-27 | Grid-tied power conversion system from direct currents to alternating currents |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN103094923A CN103094923A (en) | 2013-05-08 |
| CN103094923B true CN103094923B (en) | 2015-07-01 |
Family
ID=48207209
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201310062485.2A Active CN103094923B (en) | 2013-02-27 | 2013-02-27 | Grid-tied power conversion system from direct currents to alternating currents |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN103094923B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103560539A (en) * | 2013-11-12 | 2014-02-05 | 浙江昱能光伏科技集成有限公司 | In-grid and off-grid mixed type direct-current-to-alternating-current system and starting method of inverters thereof |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102111080B (en) * | 2011-02-24 | 2013-09-18 | 广州智光电气股份有限公司 | Photovoltaic grid-connected inverter and control method |
| CN202167862U (en) * | 2011-07-05 | 2012-03-14 | 浙江昱能光伏科技集成有限公司 | Grid-connected solar photovoltaic staggered parallel flyback inverter |
| CN203135463U (en) * | 2013-02-27 | 2013-08-14 | 浙江昱能光伏科技集成有限公司 | DC-AC grid-connected power conversion system |
-
2013
- 2013-02-27 CN CN201310062485.2A patent/CN103094923B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN103094923A (en) | 2013-05-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Chen et al. | Design and implementation of three-phase two-stage grid-connected module integrated converter | |
| CN103166239B (en) | Centralized-distributed mixed novel energy power generation system and maximum power point tracking control method | |
| CN103607032B (en) | Renewable energy power generation, power transmission and transformation and electrical network access integral system | |
| CN202841003U (en) | Novel three-phase photovoltaic grid-connected inverter system structure | |
| CN101980436B (en) | Grid-connected photovoltaic inverter device and control method for improving conversion efficiency thereof | |
| CN101582592A (en) | Transless photovoltaic merging and inverting device and control method thereof | |
| CN104600719B (en) | A kind of photovoltaic generating system grid integration Comprehensive Reactive Power Compensation control system and method | |
| CN103138291A (en) | Wind power generation intelligent single-phase grid-connection controller | |
| CN103915856A (en) | Base station grid connected-charging photovoltaic micro-inverter system and control method thereof | |
| CN101847876A (en) | Three-phase photovoltaic grid connected inverter system | |
| CN209217732U (en) | Alternating current-direct current mixing micro-capacitance sensor energy-storage system | |
| CN103701309A (en) | Alternating-direct current power supply system for variable frequency equipment and variable frequency air conditioner | |
| CN104333036B (en) | Multi-source coordination control system | |
| Manojkumar et al. | Power electronics interface for hybrid renewable energy system—A survey | |
| CN103166489A (en) | Control circuit for three-phase high power factor rectifier | |
| CN109407035A (en) | A kind of high current generating system based on MOSFET pipe | |
| CN203589824U (en) | Renewable energy power generation, power transmission and transformation and power grid access integration system | |
| CN203135463U (en) | DC-AC grid-connected power conversion system | |
| CN201682294U (en) | Three-phase photovoltaic grid-connected inverter based on Z sources | |
| CN203151389U (en) | Control circuit of three-phase high power factor rectifier | |
| US20130234524A1 (en) | Control method for arranging dc/ac converters in parallel | |
| CN103094923B (en) | Grid-tied power conversion system from direct currents to alternating currents | |
| CN203219215U (en) | Solar energy system comprising power optimizing apparatus | |
| CN203722503U (en) | Grid-connected inverter | |
| CN202817886U (en) | Uninterruptible power source |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C53 | Correction of patent for invention or patent application | ||
| CB02 | Change of applicant information |
Address after: 314050 No. 1 Asia Pacific Road, South Lake District, Zhejiang Applicant after: Zhejiang Yuneng Technology Co., Ltd. Address before: 314050 Jiaxing, South Lake District, Zhejiang, Asia Pacific Road, No. 1 Applicant before: Altenergy Power System Inc. |
|
| COR | Change of bibliographic data |
Free format text: CORRECT: APPLICANT; FROM: ALTENERGY POWER SYSTEM INC. TO: ZHEJIANG YUNENG TECHNOLOGY CO., LTD. |
|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| PE01 | Entry into force of the registration of the contract for pledge of patent right |
Denomination of invention: Grid-tied power conversion system from direct currents to alternating currents Effective date of registration: 20190402 Granted publication date: 20150701 Pledgee: Agricultural Bank of China Limited by Share Ltd Jiaxing science and Technology Branch Pledgor: Zhejiang Yuneng Technology Co., Ltd. Registration number: 2019330000091 |
|
| PE01 | Entry into force of the registration of the contract for pledge of patent right | ||
| CP03 | Change of name, title or address |
Address after: 3 / F, building 1, No. 1, Asia Pacific Road (Jiaxing Science and technology city), Nanhu District, Jiaxing City, Zhejiang Province Patentee after: Yuneng Technology Co., Ltd Address before: 314050 No. 1 Asia Pacific Road, South Lake District, Zhejiang Patentee before: Zhejiang Yuneng Technology Co.,Ltd. |
|
| CP03 | Change of name, title or address | ||
| PC01 | Cancellation of the registration of the contract for pledge of patent right |
Date of cancellation: 20211222 Granted publication date: 20150701 Pledgee: Agricultural Bank of China Limited by Share Ltd. Jiaxing science and Technology Branch Pledgor: Zhejiang Yuneng Technology Co.,Ltd. Registration number: 2019330000091 |
|
| PC01 | Cancellation of the registration of the contract for pledge of patent right |