CN203813688U - Inverter topological structure used for suppressing leakage current in photovoltaic grid-connected system - Google Patents
Inverter topological structure used for suppressing leakage current in photovoltaic grid-connected system Download PDFInfo
- Publication number
- CN203813688U CN203813688U CN201420232981.8U CN201420232981U CN203813688U CN 203813688 U CN203813688 U CN 203813688U CN 201420232981 U CN201420232981 U CN 201420232981U CN 203813688 U CN203813688 U CN 203813688U
- Authority
- CN
- China
- Prior art keywords
- diode
- controlled switch
- leakage current
- anode
- topological structure
- 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.)
- Expired - Fee Related
Links
- 239000003990 capacitor Substances 0.000 claims description 3
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 2
- 229910052710 silicon Inorganic materials 0.000 claims description 2
- 239000010703 silicon Substances 0.000 claims description 2
- 230000001629 suppression Effects 0.000 abstract 1
- 238000010586 diagram Methods 0.000 description 6
- 230000005764 inhibitory process Effects 0.000 description 2
- 238000002955 isolation Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 230000001172 regenerating effect Effects 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/50—Photovoltaic [PV] energy
- Y02E10/56—Power conversion systems, e.g. maximum power point trackers
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
- Y02E40/40—Arrangements for reducing harmonics
Abstract
The utility model relates to the field of leakage current suppression technology, in particular to an inverter topological structure used for suppressing leakage current in a photovoltaic grid-connected system, and solves the problem that the existing grid-connected inverter topological structure cannot suppress the leakage current. A positive electrode of a power supply is connected with a cathode of a first diode, a cathode of a second diode, an input end of a third controlled switch and an input end of a fourth controlled switch simultaneously, a negative electrode of the power supply is connected with an output end of a first controlled switch, an output end of a second controlled switch, an anode of a third diode and an anode of a fourth diode simultaneously, an anode of the first diode is connected with an input end of the first controlled switch, an anode of the second diode is connected with an input end of the second controlled switch, a cathode of the third diode is connected with an output end of the third controlled switch, a cathode of the fourth diode is connected with an output end of the fourth controlled switch, one end of a first inductor is connected with the anode of the first diode and the output end of the third controlled switch simultaneously, and one end of a second inductor is connected with the input end of the second controlled switch and the anode of the fourth diode. The inverter topological structure is suitable for suppressing leakage current in the photovoltaic grid-connected system.
Description
Technical field
The utility model relates to and suppresses leakage current technical field.
Background technology
In recent years, there is serious problem of energy crisis in the world, and striving to find new energy supply is the unique channel of dealing with problems.Because the regenerative resources such as wind energy, solar energy, biological energy source have free of contamination performance, they are more and more received publicity, therefore, status and the effect of distributed generation system in electric power system becomes increasingly conspicuous.By comparing, in various types of new forms of energy, solar energy has good availability and continuation, and therefore, it is undoubtedly best selection.
Because the direct current energy that must solar energy could be sent through interface equipment is incorporated in AC network.Grid-connected interface mode generally has electronic power inverter interface and conventional electric rotating machine interface two classes, the former is all better than the latter at aspects such as volume, weight, conversion efficiency, reliability, electrical properties, therefore, photovoltaic system generally adopt voltage source inverter as and network interface.Realizing unity power factor by control inverter output current and line voltage with frequency homophase generates electricity by way of merging two or more grid systems.
For ensureing system safety reliability service, realize voltage adjustment and electrical isolation, traditional grid-connected inverter system is generally installed power frequency isolating transformer at output.But power frequency isolating transformer is bulky, cost is high, and loss is large, affects system overall efficiency.Therefore the combining inverter of the non-isolation of transless is the focus of studying at present.Can make grid-connected inverter system whole efficiency necessarily be improved although remove Industrial Frequency Transformer, band is served new problem, as common mode current and direct current injection etc.
In order effectively to suppress leakage current, at present, experts and scholars roughly propose two kinds of solutions both at home and abroad, wherein one is to suppress leakage current by modulation strategy, although adopt bipolarity modulation to can be good at suppressing common mode leakage current, but its loss is large, and system effectiveness is lower, another is the topological structure that improves circuit.
Utility model content
The utility model cannot suppress the problem of leakage current in order to solve the topological structure of existing grid-connected inverter system, proposed in photovoltaic parallel in system for suppressing the inverter topology of leakage current.
In photovoltaic parallel in system, comprise the first diode, the second diode, the 3rd diode, the 4th diode, the first controlled switch, the second controlled switch, the 3rd controlled switch, the 4th controlled switch, power supply, electric capacity, the first inductance and the second inductance for suppressing the inverter topology of leakage current
Described electric capacity is in parallel with power supply,
The anodal of power supply is connected with the negative electrode of the first diode, negative electrode, the input of the 3rd controlled switch and the input of the 4th controlled switch of the second diode simultaneously,
Negative pole while and the output of the first controlled switch, output, the anode of the 3rd diode and the anodic bonding of the 4th diode of the second controlled switch of power supply,
The anode of the first diode is connected with the input of the first controlled switch,
The anode of the second diode is connected with the input of the second controlled switch,
The negative electrode of the 3rd diode is connected with the output of the 3rd controlled switch,
The negative electrode of the 4th diode is connected with the output of the 4th controlled switch,
One end of the first inductance is connected with the anode of the first diode and the output of the 3rd controlled switch simultaneously,
One end while and the input of the second controlled switch and the anodic bonding of the 4th diode of the second inductance,
The other end of the other end of the first inductance and the second inductance is connected to the grid.
Beneficial effect: simple in structure in topological structure described in the utility model, number of switches is few, can be cost-saving to the full extent, can reduce rate of breakdown simultaneously.
By the controlled switch conducting in adjustment topological structure and the state of disconnection, making topological structure common-mode voltage within the whole cycle constant is U
in/ 2, in the time that common-mode voltage is constant, the leakage current of described topological structure is 0, thereby has realized the object of effective inhibition leakage current;
The topological structure that the utility model proposes is compared with existing topological structure, simple in structure, and total number of switches only has 4, and the switch that works in high frequency only has two, and two other works in mains frequency, and loss is lower than H
5, H
6with HERIC topological structure, improve the efficiency of photovoltaic parallel in system.
Brief description of the drawings
Fig. 1 is for suppressing the structural representation of inverter topology of leakage current in photovoltaic parallel in system;
Fig. 2 is for suppressing the inverter topology positive half period operation principle schematic diagram of leakage current in photovoltaic parallel in system;
Fig. 3 is for suppressing the inverter topology positive half period afterflow operation principle schematic diagram of leakage current in photovoltaic parallel in system;
Fig. 4 is for suppressing the inverter topology negative half-cycle operation principle schematic diagram of leakage current in photovoltaic parallel in system;
Fig. 5 is for suppressing the inverter topology negative half-cycle afterflow operation principle schematic diagram of leakage current in photovoltaic parallel in system;
Fig. 6 is for suppressing the common-mode voltage oscillogram of inverter topology of leakage current in photovoltaic parallel in system;
Fig. 7 is for suppressing the leakage current oscillogram of inverter topology of leakage current in photovoltaic parallel in system;
Fig. 8 be in photovoltaic parallel in system for the inverter topology that suppresses leakage current when the grid-connected work, the total percent harmonic distortion oscillogram of electric current.
Embodiment
Embodiment one, in conjunction with Fig. 1, this embodiment is described, in photovoltaic parallel in system described in this embodiment, comprise the first diode (D1), the second diode (D2), the 3rd diode (D3), the 4th diode (D4), the first controlled switch (S1), the second controlled switch (S2), the 3rd controlled switch (S3), the 4th controlled switch (S4), power supply (U), electric capacity (C), the first inductance (L1) and the second inductance (L2) for suppressing the inverter topology of leakage current
Described capacitor C is in parallel with power supply U,
The anodal of power supply U is connected with the negative electrode of the first diode D1, negative electrode, the input of the 3rd controlled switch S3 and the input of the 4th controlled switch S4 of the second diode D2 simultaneously,
Negative pole while and the output of the first controlled switch S1, output, the anode of the 3rd diode D3 and the anodic bonding of the 4th diode D4 of the second controlled switch S2 of power supply U,
The anode of the first diode D1 is connected with the input of the first controlled switch S1,
The anode of the second diode D2 is connected with the input of the second controlled switch S2,
The negative electrode of the 3rd diode D3 is connected with the output of the 3rd controlled switch S3,
The negative electrode of the 4th diode D4 is connected with the output of the 4th controlled switch S4,
One end of the first inductance L 1 is connected with the anode of the first diode D1 and the output of the 3rd controlled switch S3 simultaneously,
One end while and the input of the second controlled switch S2 and the anodic bonding of the 4th diode D4 of the second inductance L 2,
The other end of the other end of the first inductance L 1 and the second inductance L 2 is connected to the grid.
Difference for the inverter topology that suppresses leakage current in photovoltaic parallel in system described in embodiment two, this embodiment and embodiment one is, described controlled switch is a kind of in IGBT, MOSFET or silicon controlled rectifier or wherein several combination.
Four kinds of operating states that provided respectively topological structure described in the utility model in Fig. 2-Fig. 4, the direction of arrow is inverter current direction, and the magnitude of voltage of power supply U is U
in.
Fig. 2 and Fig. 3 represent in photovoltaic parallel in system for suppressing the inverter topology positive half period operation principle schematic diagram of leakage current, in positive half period, the 3rd controllable switch S 3 remains conducting, the first controllable switch S 1 and the 4th controllable switch S 4 remain disconnection, in the time of the second controllable switch S 2 conducting, the common-mode voltage of described topological structure is U
in/ 2; In the time that the second controllable switch S 2 disconnects, electric current is through the 3rd controllable switch S 3 and the second diode D2 afterflow, and the common-mode voltage of described topological structure is U
in/ 2.
Fig. 4 and Fig. 5 represent in photovoltaic parallel in system for suppressing the inverter topology negative half-cycle operation principle schematic diagram of leakage current, in negative half-cycle, the 4th controlled switch S4 remains conducting, the second controlled switch S2 and the 3rd controlled switch S3 remain disconnection, in the time of the first controlled switch S1 conducting, the common-mode voltage of described topological structure is U
in/ 2; In the time that the first controlled switch S1 disconnects, electric current is through the 4th controlled switch S3 and the first diode D1 afterflow, and the common-mode voltage of described topological structure is U
in/ 2;
By above-mentioned control to controlled switch conducting and disconnection and in conjunction with the common mode current oscillogram shown in the common-mode voltage oscillogram shown in Fig. 6 and Fig. 7, can draw topological structure described in the utility model common-mode voltage within the whole cycle constant be U
in/ 2, in the time that common-mode voltage is constant, the leakage current of described topological structure is 0, thereby has realized the object of effective inhibition leakage current., can draw according to the total percent harmonic distortion oscillogram shown in Fig. 8, rate of total harmonics (THD) is 1.99%, meets the requirement to rate of total harmonics standard in IEEE Std929-2000 meanwhile.
Claims (2)
- In photovoltaic parallel in system for suppressing the inverter topology of leakage current, it is characterized in that, it comprises the first diode D1, the second diode D2, the 3rd diode D3, the 4th diode D4, the first controlled switch S1, the second controlled switch S2, the 3rd controlled switch S3, the 4th controlled switch S4, power supply U, capacitor C, the first inductance L 1 and the second inductance L 2Described capacitor C is in parallel with power supply U,The anodal of power supply U is connected with the negative electrode of the first diode D1, negative electrode, the input of the 3rd controlled switch S3 and the input of the 4th controlled switch S4 of the second diode D2 simultaneously,Negative pole while and the output of the first controlled switch S1, output, the anode of the 3rd diode D3 and the anodic bonding of the 4th diode D4 of the second controlled switch S2 of power supply U,The anode of the first diode D1 is connected with the input of the first controlled switch S1,The anode of the second diode D2 is connected with the input of the second controlled switch S2,The negative electrode of the 3rd diode D3 is connected with the output of the 3rd controlled switch S3,The negative electrode of the 4th diode D4 is connected with the output of the 4th controlled switch S4,One end of the first inductance L 1 is connected with the anode of the first diode D1 and the output of the 3rd controlled switch S3 simultaneously,One end while and the input of the second controlled switch S2 and the anodic bonding of the 4th diode D4 of the second inductance L 2,The other end of the other end of the first inductance L 1 and the second inductance L 2 is connected to the grid.
- In photovoltaic parallel in system according to claim 1 for suppressing the inverter topology of leakage current, it is characterized in that, described controlled switch is a kind of in IGBT, MOSFET or silicon controlled rectifier or wherein several combination.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420232981.8U CN203813688U (en) | 2014-05-08 | 2014-05-08 | Inverter topological structure used for suppressing leakage current in photovoltaic grid-connected system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420232981.8U CN203813688U (en) | 2014-05-08 | 2014-05-08 | Inverter topological structure used for suppressing leakage current in photovoltaic grid-connected system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN203813688U true CN203813688U (en) | 2014-09-03 |
Family
ID=51452387
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201420232981.8U Expired - Fee Related CN203813688U (en) | 2014-05-08 | 2014-05-08 | Inverter topological structure used for suppressing leakage current in photovoltaic grid-connected system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN203813688U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103929085A (en) * | 2014-05-08 | 2014-07-16 | 国家电网公司 | Inverter topological structure used for preventing leakage currents in photovoltaic grid-connected system |
| CN106411171A (en) * | 2016-10-14 | 2017-02-15 | 江苏大学 | Transformer-free type low-leakage-current photovoltaic grid-connected inverter circuit with active clamp and modulation method thereof |
-
2014
- 2014-05-08 CN CN201420232981.8U patent/CN203813688U/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103929085A (en) * | 2014-05-08 | 2014-07-16 | 国家电网公司 | Inverter topological structure used for preventing leakage currents in photovoltaic grid-connected system |
| CN106411171A (en) * | 2016-10-14 | 2017-02-15 | 江苏大学 | Transformer-free type low-leakage-current photovoltaic grid-connected inverter circuit with active clamp and modulation method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN202535290U (en) | Photovoltaic inverter circuit | |
| CN103051233A (en) | Non-isolated single-phase photovoltaic grid-connected inverter and on-off control timing sequence thereof | |
| CN202513843U (en) | Full-bridge grid-connected inverter | |
| CN202004681U (en) | Topological structure of photovoltaic grid-connected inverter | |
| CN201536328U (en) | grid-connected inverter | |
| CN105356784A (en) | Grid connected inverter with DC bus voltage balance function | |
| CN104410310A (en) | Neutral point clamped H-bridge photovoltaic inverter and method for inhibiting common mode leakage current | |
| CN205029572U (en) | Novel single -phase non - isolation grid -connected inverter of H6 | |
| CN202524315U (en) | DC/AC grid-connected inversion circuit | |
| CN203813688U (en) | Inverter topological structure used for suppressing leakage current in photovoltaic grid-connected system | |
| CN203827203U (en) | High-power optical storage integrated converter | |
| CN201515320U (en) | Grid-connected inverter | |
| CN103337975A (en) | Current source transverter and control method thereof | |
| CN105553271A (en) | Control method of three-phase DC converter | |
| CN102882228A (en) | Single-phase non-isolated photovoltaic grid-connected inverter | |
| CN102403920A (en) | Three-level half-bridge photovoltaic grid connected inverter | |
| CN102769394B (en) | Single-phase controllable rectification circuit | |
| CN102255356A (en) | Efficient uninterruptible power supply | |
| CN103269174A (en) | Single-phase photovoltaic grid-connected inverter with low common-mode voltage | |
| CN204707055U (en) | A kind of Novel photovoltaic grid-connected inverter | |
| CN201018416Y (en) | Isolation type high-frequency bidirectional DC circuit | |
| CN202385026U (en) | Miniature photovoltaic inverter | |
| CN202334357U (en) | Three-level half-bridge photovoltaic grid-connected inverter | |
| CN203301393U (en) | Non transformer single-phase grid connected inverter | |
| CN202957614U (en) | High-efficiency transformer-free single-phase photovoltaic grid-connected inverter |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20140903 Termination date: 20190508 |