CN103094923A - 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
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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 that exchanges, specifically, the present invention relates to a kind of direct current to the electric power coversion system that is incorporated into the power networks that exchanges.
Background technology
At the renewable energy source domain, such as photovoltaic and wind energy, have and use little inverter the direct current power of each power supply to be converted to the alternating electromotive force of the output of can being incorporated into the power networks, and each power supply is carried out 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 little inverter system of the prior art connects DC power supply and electrical network.As shown in Figure 1, this little inverter system comprise a plurality of respectively with single DC power supply 101
1, 101
2... 101
NThe inverter 102 that connects
1, 102
2... 102
NEach inverter 102
1, 102
2... 102
NInput and each DC power supply 101
1, 101
2... 101
NCorresponding connection of output, each inverter 102
1, 102
2... 102
NOutput-parallel, each inverter 102 namely
1, 102
2... 102
NLive wire L103 be connected, zero line N104 is connected, and then connects electrical network 105.Be exactly each inverter 102 like this
1, 102
2... 102
NWith DC power supply 101
1, 101
2... 101
NDirectly be converted to the alternating current identical with electrical network 105.But so little inverter system has following point:
1. inverter design is complicated.Prior art is converted to alternating current by single inverter with direct voltage and is incorporated into the power networks, and is for avoiding affecting the quality of electrical network, very high to the quality requirement of AC wave shape; Be system safety, also require to possess perfect defencive function.
2. low efficient.DC power supply commonly used is tens volts as the voltage of photovoltaic module, battery etc., and more than the peak value of grid alternating current was generally 380V, the multiple that so just needs direct voltage to boost was very high, causes very low conversion efficiency.
3. high cost.Except power conversion circuit, each inverter also needs other various circuit guarantee to be incorporated into the power networks quality, realize being incorporated into the power networks protection, EMC, communication etc., has caused too high cost.
4. low reliability.The AC of each inverter is the voltage that is incorporated into the power networks, and voltage is high, and is large to the stress of various power devices, and directly connects electrical network, easily is subject to the impact of electrical network anomaly, thus injury.
Summary of the invention
Technical problem to be solved by this invention is to provide a kind of direct current to the electric power coversion system that is incorporated into the power networks that exchanges, and can simplify the design of inverter, improves the efficient 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 electric power coversion system that is incorporated into the power networks that exchanges, comprising:
A plurality of inverters, connect one to one with a plurality of DC power supply respectively, the input of described inverter is connected with the output of described DC power supply, the output of each the described inverter bunchiness that is connected to each other, 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 detection of the interchange output characteristic of described inverter string and detect the AC characteristic of described electrical network, after the parameter of obtaining the various electrical energy parameters of described inverter string and described electrical network and should be able to calculating mutually, data are processed and described inverter is controlled.
Alternatively, described inverter comprises:
The direct current detection module is connected with the direct-flow input end of described inverter, for detection of DC input voitage and the direct current input current of the described inverter of input;
Power conversion circuit is connected with ac output end with the direct-flow input end of described inverter respectively, is used for direct current is converted to alternating current;
The conversion and control module is connected with described power conversion circuit with described direct current detection module respectively, for generation of with send to described power conversion circuit one to drive signal, with the alternating current of realizing wanting;
First communication module externally is connected with described and wire stitcher, is used for data and command signal that acquisition needs, and perhaps the data with described inverter send to described and wire stitcher or other communication equipment;
The alternating-current parameter acquisition module is connected with described conversion and control module with described first communication module respectively, is used for obtaining by data described and that wire stitcher obtains, calculates to obtain the alternating-current parameter that needs, and offers described conversion and control module.
Alternatively, described inverter also comprises:
Exchange detection module, be connected with described conversion and control module with the ac output end of described inverter respectively, for detection of ac output voltage and the ac output current of the described inverter of output, and feed back to described conversion and control module.
Alternatively, described and wire stitcher comprises:
The inverter detection module is for detection of the interchange output characteristic of described inverter string;
The electrical network detection module is for detection of the AC characteristic of described electrical network;
The protection module that is incorporated into the power networks is used for realizing the function of electric network protection;
The inverter communication module is used for and a plurality of described inverters communicate, and collects the data of described inverter or sends control command to described inverter;
System control module; be connected with the inverter communication module with described inverter detection module, electrical network detection module, the protection module that is incorporated into the power networks respectively; be used for carrying out data according to the AC characteristic of the interchange output characteristic of described inverter string, described electrical network and process, and produce to described inverter and/or to the various control commands of the above-mentioned internal module of described and wire stitcher.
Alternatively, described and wire stitcher also comprises:
The correspondence with foreign country module is used for and outside other equipment communicate, with the transmission of 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 electric current, voltage, frequency, phase place, zero crossing and the parameter that should be able to calculate mutually thereof;
The described parameter that wherein, 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 anti-sharp diode, the former limit winding of described transformer is connected with described DC power supply;
The power frequency full bridge inverter is connected with described electrical network with the secondary winding of the described transformer of described circuit of reversed excitation respectively, and it comprises the full bridge structure that is comprised of four switching tubes;
Dc detection circuit is connected with the output of described DC power supply, for detection of DC input voitage and the direct current input current of the described inverter of input;
Second communication module externally is connected with described and wire stitcher, is used for data and command signal that acquisition needs, and perhaps the data with described inverter send to described and wire stitcher or other communication equipment;
The full-bridge control module is connected with described power frequency full bridge inverter with described second communication module respectively, is used for the described switching tube of the full bridge structure of described power frequency full bridge inverter is controlled;
The reference current computing module, be connected with described second communication module with described dc detection circuit respectively, be used for calculating the acquisition reference current according to phase place and the time of DC input voitage value, ac output voltage value, ac output current value, ac output voltage;
Anti-sharp control circuit, be connected with the grid of the former limit switching tube of the former limit winding of described reference current computing module, described transformer and described circuit of reversed excitation respectively, be used for the sampling primary current and contrast with described reference current, producing the anti-driving signal of controlling that swashs.
Alternatively, described electrical network and described inverter are single-phase electrical network and inverter, are perhaps two-phase electrical network and the inverter with 1 zero line and 2 live wires, or for having three phase network and the inverter of 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 the alternating voltage that is incorporated into the power networks, 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 efficient of inverter.Reduce the ac output voltage of inverter to the output voltage near DC power supply, conversion coefficient is little, can improve conversion efficiency.
3. reduce the cost of inverter.Reduce the ac output voltage of inverter to the output voltage near DC power supply, can adopt low voltage component, reduce costs thus.The circuit modules such as protection, communication that also will be incorporated into the power networks in addition focus on and wire stitcher in, simplify cable, reduce costs.
4. improve the reliability of inverter.Reduce the voltage stress of power device, also reduce extremely possible to the inverter damage of electrical network.
In sum, with existing Miniature inverter contrast, the present invention has all advantages of Miniature inverter system, only direct current need to be converted to the alternating current that voltage approaches, and do not need to boost to identical with line voltage, thereby simplified inverter design, improved conversion efficiency, reduce the cost of inverter, promoted the reliability of inverter.
Description of drawings
The above and other features of the present invention, character and advantage will become more obvious by the description below in conjunction with drawings and Examples, wherein:
Fig. 1 is the modular structure schematic diagram that a kind of little inverter system of the prior art connects DC power supply and electrical network;
Fig. 2 is that the direct current of one embodiment of the invention connects the modular structure schematic diagram of DC power supply and electrical network to the electric power coversion system that is incorporated into the power networks that exchanges;
Fig. 3 is the internal module structural representation of direct current inverter in the electric power coversion system that is incorporated into the power networks that exchanges of one embodiment of the invention;
Fig. 4 is that the direct current of one embodiment of the invention is in the electric power coversion system that is incorporated into the power networks that exchanges and the internal module structural representation of wire stitcher;
Fig. 5 is an inside ball bearing made using schematic diagram that connects the back exciting converter that is incorporated into the power networks of DC power supply and electrical network of the prior art;
Fig. 6 is the inside ball bearing made using schematic diagram of the back exciting converter that is incorporated into the power networks in the electric power coversion system that is incorporated into the power networks of the connection DC power supply of one embodiment of the invention and electrical network.
Embodiment
The invention will be further described below in conjunction with specific embodiments and the drawings; set forth in the following description more details so that fully understand the present invention; but the present invention obviously can implement with the multiple alternate manner that is different from this description; those skilled in the art can be in the situation that do similar popularization, deduction without prejudice to intension of the present invention according to practical situations, therefore should be with content constraints protection scope of the present invention of this specific embodiment.
Fig. 2 is that the direct current of one embodiment of the invention connects the modular structure schematic diagram of DC power supply and electrical network to the electric power coversion system that is incorporated into the power networks that exchanges.It should be noted that this and follow-up other accompanying drawing all only as example, it is not to be to draw according to the condition of equal proportion, and should not be construed as limiting as the protection range to actual requirement of the present invention with this.As shown in Figure 2, this direct current mainly comprises a plurality of inverters 202 and one and wire stitcher 203 to the electric power coversion system that is incorporated into the power networks that exchanges.Wherein, a plurality of inverters 202
1, 202
2... 202
i... 202
N(describe easyly for asking, unifiedly be designated as 202) respectively with a plurality of 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, the output of each inverter 202 bunchiness that is connected to each other, 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, and output is connected with electrical network 208.And wire stitcher 203 is for detection of the interchange output characteristic of inverter string and the AC characteristic of detection of grid 208, after the parameter of obtaining the various electrical energy parameters of inverter string and electrical network 208 and should be able to calculating mutually, data are processed and inverter 202 is controlled.
Due to and the output of wire stitcher 203 directly connect electrical network 208, so total ac output voltage Vout equals line voltage Vgrid.And wire stitcher 203 detection of grid voltages and the ac output current Iout that passes through.Each inverter 202
iDC input voitage be designated as Vdci, the direct current input current is designated as Idci, the direct current input power is designated as Pdci, the ac output voltage effective value is designated as Vaci, the ac output current effective value is designated as Iaci, exchanges power output and is designated as Paci.And total interchange power output of a string inverter (inverter string) is designated as Pout, and ac output voltage is designated as Vout, and ac output current is designated as Iout.
For a plurality of inverter i=2～N (N is the natural number greater than 2), after each inverter detected DC input voitage Vdci and direct current input current Idci, multiplying each other to calculate obtained direct current input power Pdci.Suppose that energy is κ by the efficient that DC side is transferred to AC, so the power output P of each inverter
i=κ * P
dci, κ is about a parameter of 1.Be exactly total the summation of the interchange power output Pout Pi of a string inverter.Total ac output voltage Vout of a string inverter equals line voltage Vgrid.Due to the output series connection of these inverters, the electric current I aci of this string inverter equates everywhere, for Iout equals Pout/Vout.The ac output voltage Vaci of each inverter equals Pi/Iaci.
The unified conclusion of the computing formula of all power, electric current and the voltage of the above-mentioned single inverter 202i that applies to or whole inverter string 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 inverter in the electric power coversion system that is incorporated into the power networks that exchanges of one embodiment of the invention.As shown in Figure 3, this inverter 400 mainly comprises direct current detection module 403, power conversion circuit 405, conversion and control module 407, alternating-current parameter acquisition module 409 and first communication module 411.Wherein, direct current detection module 403 is connected with the direct-flow input end of inverter 400, for detection of 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, is used for direct current is converted to alternating current.Conversion and control module 407 is connected with power conversion circuit 405 with direct current detection module 403 respectively, for generation of with send to power conversion circuit 405 1 to drive signals, with the alternating current of realizing wanting.First communication module 411 externally with and wire stitcher 203 be connected, be used for obtaining the data and the command signal that need, perhaps the data with inverter 400 send also wire stitcher 203 or other communication equipment to.Alternating-current parameter acquisition module 409 is connected with conversion and control module 407 with first communication module 411 respectively, be used for obtaining by and the data that obtain of wire stitcher 203, calculate to obtain the alternating-current parameter that needs, offer 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 detection of 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 electric power coversion system that is incorporated into the power networks that exchanges and the internal module structural representation of wire stitcher.As shown in Figure 4, should and wire stitcher 500 mainly comprises inverter detection module 503, electrical network detection module 505, the protection module 507 that is incorporated into the power networks, inverter communication module 509 and system control module 511.Wherein, inverter detection module 503 comprises various electrical energy parameters for detection of the interchange output characteristic of inverter string 501, as electric current, voltage, frequency, phase place, zero crossing etc., and the corresponding parameter that calculates, as current effective value, active power, reactive power and power factor etc.Electrical network detection module 505 comprises various electrical energy parameters for detection of the AC characteristic of electrical network 502, as voltage, frequency and phase place etc.The protection module 507 of being incorporated into the power networks is used for realizing the function of electric network protection, when line voltage, frequency exceed the protection range of setting, perhaps during grid power blackout, drives and wire stitcher 500 turn-offs and is connected connection with electrical network.Inverter communication module 509 is used for and a plurality of inverters 202 communicate, and collects 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 network detection module 505, the protection module 507 that is incorporated into the power networks respectively; the AC characteristic that is used for interchange output characteristic, electrical network 502 according to inverter string 501 is carried out data and is processed, and produce to inverter 202 and/or to and the various control commands of the above-mentioned internal module of wire stitcher 500.
In the present embodiment, also wire stitcher 500 can also comprise correspondence with foreign country module 513, is used for communicating with outside other equipment, with the transmission of data and control command.Wherein, outside other equipment can comprise computer, internet router and mobile phone.
Fig. 5 is an inside ball bearing made using schematic diagram that connects the back exciting converter that is incorporated into the power networks of DC power supply and electrical network of the prior art.As shown in Figure 5, this inverter 600 is connected with the DC power supply 601 in left side and the electrical network 602 on right side respectively.In Fig. 5, inverter 600 is comprised of decoupling capacitance Cin, circuit of reversed excitation 604 and power frequency full bridge inverter 606.Wherein, circuit of reversed excitation 604 is mainly by former limit switching tube S
M1, transformer T
1And anti-sharp diode D
1Form.Parallel network reverse 606 comprises by four switching tube S
AC1～S
AC4The full bridge structure that forms.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
M1Swash by anti-the driving signal controlling of controlling, and the anti-sharp driving signal of controlling swashs control circuit through primary current and reference current contrast generation by anti-.Reference current is obtained by dc voltage value, ac voltage, alternating current flow valuve, interchange phase place and Time Calculation.In prior art, AC detection circuit detects the interchange output of inverter 600, and the parameter that acquisition needs offers the reference current computing module.In addition, the AC signal that AC detection circuit detects also sends to the full-bridge control module, is used 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 having obtained these parameters, the reference current computing module can calculate the reference current value Iref of each time point t easily according to above-mentioned formula.
Fig. 6 is the inside ball bearing made using schematic diagram of the back exciting converter that is incorporated into the power networks in the electric power coversion system that is incorporated into the power networks of the connection DC power supply of one embodiment of the invention and 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, anti-sharp 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 anti-sharp 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
1The secondary winding be connected with electrical network 602, it comprises by four switching tube S
AC1～S
AC4The full bridge structure that forms.Dc detection circuit is connected with the output of DC power supply 601, for detection of DC input voitage and the direct current input current of input inverter 600.Second communication module externally with and wire stitcher 603 be connected, be used for obtaining the data and the command signal that need, perhaps the data with inverter 600 send also wire stitcher 603 or other communication equipment to.The full-bridge control module is connected with power frequency full bridge inverter 606 with second communication module respectively, is used for the switching tube S to the full bridge structure of power frequency full bridge inverter 606
AC1～S
AC4Control.The reference current computing module is connected with second communication module with dc detection circuit respectively, is used for calculating the acquisition reference current according to phase place and the time of DC input voitage value, ac output voltage value, ac output current value, ac output voltage.Anti-swash 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, be used for the sampling primary current and with the reference current contrast, produce the anti-driving signal of controlling that swashs.
As seen, in the present embodiment, different with above-mentioned prior art is there is no AC detection circuit, but by second communication module from and wire stitcher 603 obtain alternating-current parameters, and send reference current to and calculate and need and full-bridge is controlled.The calculating of reference current remains adopts following formula:
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 having obtained these parameters, the reference current computing module can calculate the reference current value Iref of each time point t easily according to above-mentioned formula.
In above-mentioned parameters, obtain following signal by dc detection circuit: the DC input voitage Vdc that input voltage test section wherein provides, the direct current input current Idc that the input current test section 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 a plurality of inverter i=2～N (N is the natural number greater than 2), after each inverter detected DC input voitage Vdci and direct current input current Idci, multiplying each other to calculate obtained direct current incoming frequency Pdci.Then each inverter sends to this power and wire stitcher 603 by second communication module.And wire stitcher 603 calculates acquisition interchange power output Pout to the direct current input power Pdci that is sent by all inverters in a string inverter of correspondence.And the effective value Vgrid of wire stitcher 603 detection of grid voltages, and the design of wire stitcher 603 is Vgrid that total ac output voltage Vout of a string inverter equals 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.Because the interchange power output of each inverter is Pac, ac output current is Iac=Iout, and to obtain ac output voltage be Vac=Pi/Iout so each inverter just can calculate.
In reference current Iref there be all parameters like this, is easy to calculate reference current Iref, is used for the electric power conversion and control.
It is take circuit of reversed excitation and power frequency full bridge inverter structure as example that the main body of above-mentioned inverter consists of, but can be also other topology.
In addition, the electrical network 208 in above-described embodiment and inverter 202 be take single-phase electrical network and inverter as example, but can be also other electrical network and inverter, such as two-phase, has 1 zero line and 2 live wires; Perhaps three-phase, have 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 the alternating voltage that is incorporated into the power networks, 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 efficient of inverter.Reduce the ac output voltage of inverter to the output voltage near DC power supply, conversion coefficient is little, can improve conversion efficiency.
3. reduce the cost of inverter.Reduce the ac output voltage of inverter to the output voltage near DC power supply, can adopt low voltage component, reduce costs thus.The circuit modules such as protection, communication that also will be incorporated into the power networks in addition focus on and wire stitcher in, simplify cable, reduce costs.
4. improve the reliability of inverter.Reduce the voltage stress of power device, also reduce extremely possible to the inverter damage of electrical network.
In sum, with existing Miniature inverter contrast, the present invention has all advantages of Miniature inverter system, only direct current need to be converted to the alternating current that voltage approaches, and do not need to boost to identical with line voltage, thereby simplified inverter design, improved conversion efficiency, reduce the cost of inverter, promoted the reliability of inverter.
Although the present invention with preferred embodiment openly as above, it is not to limit the present invention, and any those skilled in the art can make possible change and modification without departing from the spirit and scope of the present invention.Therefore, every content that does not break away from technical solution of the present invention, according to technical spirit of the present invention to any modification, equivalent variations and modification that above embodiment does, within all falling into the protection range that claim of the present invention defines.
Claims (9)
1. a direct current to the electric power coversion system that is incorporated into the power networks that exchanges, comprising:
A plurality of inverters (202), connect one to one with a plurality of DC power supply (201) respectively, the input of described inverter (202) is connected with the output of described DC power supply (201), the output of each described inverter (202) bunchiness that is connected to each other, the live wire (L) of the zero line of previous inverter (N) and a rear inverter is connected;
And wire stitcher (203), its input is connected with zero line (206) with the live wire (205) at inverter string two ends respectively, its output is connected with electrical network (208), described and wire stitcher (203) is for detection of the interchange output characteristic of described inverter string and detect the AC characteristic of described electrical network (208), after the parameter of obtaining the various electrical energy parameters of described inverter string and described electrical network (208) and should be able to calculating mutually, data are processed and described inverter (202) is controlled.
2. the electric power coversion system that is incorporated into the power networks according to claim 1, is characterized in that, described inverter (400) comprising:
Direct current detection module (403) is connected with the direct-flow input end of described inverter (400), for detection of DC input voitage and the direct current input current of the described inverter of input (400);
Power conversion circuit (405), the direct-flow input end with described inverter (400) is connected with ac output end respectively, is used for direct current is converted to alternating current;
Conversion and control module (407), be connected with described power conversion circuit (405) with described direct current detection module (403) respectively, for generation of with send to described power conversion circuit (405) to drive signals, with the alternating current of realizing wanting;
First communication module (411), externally be connected with described and wire stitcher (203), be used for data and command signal that acquisition needs, perhaps the data with described inverter (400) send to described and wire stitcher (203) or other communication equipment;
Alternating-current parameter acquisition module (409), be connected with described conversion and control module (407) with described first communication module (411) respectively, be used for obtaining the data that obtained by described and wire stitcher (203), calculate to obtain the alternating-current parameter that needs, offer described conversion and control module (407).
3. the electric power coversion system that is incorporated into the power networks according to claim 2, is characterized in that, described inverter (400) also comprises:
Exchange detection module (413), be connected with described conversion and control module (407) with the ac output end of described inverter (400) respectively, for detection of ac output voltage and the ac output current of the described inverter of output (400), and feed back to described conversion and control module (407).
4. the electric power coversion system that is incorporated into the power networks according to claim 1, is characterized in that, described and wire stitcher (500) comprising:
Inverter detection module (503) is for detection of the interchange output characteristic of described inverter string (501);
Electrical network detection module (505) is for detection of the AC characteristic of described electrical network (502);
The protection module (507) that is incorporated into the power networks is used for realizing the function of electric network protection;
Inverter communication module (509) is used for and a plurality of described inverters (202) communicate, and collects the data of described inverter (202) or sends control command to described inverter (202);
System control module (511); be connected with described inverter detection module (503), electrical network detection module (505), the protection module that is incorporated into the power networks (507) and inverter communication module (509) respectively; be used for carrying out data according to the AC characteristic of the interchange output characteristic of described inverter string (501), described electrical network (502) and process, and produce to described inverter (202) and/or to the various control commands of the above-mentioned internal module of described and wire stitcher (500).
5. the electric power coversion system that is incorporated into the power networks according to claim 4, is characterized in that, described and wire stitcher (500) also comprises:
Correspondence with foreign country module (513) is used for and outside other equipment communicate, with the transmission of data and control command;
Wherein, other equipment of described outside comprise computer, internet router and mobile phone.
6. the according to claim 4 or 5 described electric power coversion systems that are incorporated into the power networks, is characterized in that, the interchange output characteristic of described inverter string (501) comprises electric current, voltage, frequency, phase place, zero crossing and the parameter that should be able to calculate mutually thereof;
The described parameter that wherein, should be able to calculate mutually comprises current effective value, active power, reactive power and power factor.
7. the according to claim 4 or 5 described electric power coversion systems that are incorporated into the power networks, is characterized in that, the AC characteristic of described electrical network (208) comprises voltage, frequency and phase place.
8. the electric power coversion system that is incorporated into the power networks according to claim 1, is characterized in that, described inverter (600) comprising:
Decoupling capacitance (Cin) is connected across the two ends of described DC power supply (601);
Circuit of reversed excitation (604), it comprises former limit switching tube (S
M1), transformer (T
1) and anti-sharp diode (D
1), described transformer (T
1) former limit winding be connected with described DC power supply (601);
Power frequency full bridge inverter (606) is respectively with the described transformer (T of described circuit of reversed excitation (604)
1) the secondary winding be connected with described electrical network (602), it comprises by four switching tube (S
AC1～S
AC4) full bridge structure that forms;
Dc detection circuit is connected with the output of described DC power supply (601), for detection of DC input voitage and the direct current input current of the described inverter of input (600);
Second communication module externally is connected with described and wire stitcher (603), is used for data and command signal that acquisition needs, and perhaps the data with described inverter (600) send to described and wire stitcher (603) or other communication equipment;
The full-bridge control module is connected with described power frequency full bridge inverter (606) with described second communication module respectively, is used for the described switching tube (S to the full bridge structure of described power frequency full bridge inverter (606)
AC1～S
AC4) control;
The reference current computing module, be connected with described second communication module with described dc detection circuit respectively, be used for calculating the acquisition reference current according to phase place and the time of DC input voitage value, ac output voltage value, ac output current value, ac output voltage;
Anti-sharp control circuit is respectively with described reference current computing module, described transformer (T
1) former limit winding and the former limit switching tube (S of described circuit of reversed excitation (604)
M1) grid be connected, be used for the sampling primary current and with described reference current contrast, produce the anti-driving signal of controlling that swashs.
9. the electric power coversion system that is incorporated into the power networks according to claim 1, it is characterized in that, described electrical network (208) and described inverter (202) are single-phase electrical network and inverter, be perhaps two-phase electrical network and the inverter with 1 zero line and 2 live wires, or for having three phase network and the inverter of 1 zero line and 3 live wires.
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| CN201310062485.2A CN103094923B (en) | 2013-02-27 | 2013-02-27 | Grid-tied power conversion system from direct currents to alternating currents |
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| CN103094923B CN103094923B (en) | 2015-07-01 |
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Cited By (1)
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