CN202957614U - High-efficiency transformer-free single-phase photovoltaic grid-connected inverter - Google Patents
High-efficiency transformer-free single-phase photovoltaic grid-connected inverter Download PDFInfo
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- CN202957614U CN202957614U CN2012206885448U CN201220688544U CN202957614U CN 202957614 U CN202957614 U CN 202957614U CN 2012206885448 U CN2012206885448 U CN 2012206885448U CN 201220688544 U CN201220688544 U CN 201220688544U CN 202957614 U CN202957614 U CN 202957614U
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/50—Photovoltaic [PV] energy
- Y02E10/56—Power conversion systems, e.g. maximum power point trackers
Abstract
The utility model discloses a high-efficiency transformer-free single-phase photovoltaic grid-connected inverter and relates to the inverter. The transformer-free single-phase photovoltaic grid-connected inverter comprises a solar photovoltaic array (1), a boosted circuit (2), a direct current (DC)-alternating current (AC) inverter (3), a relay (4), a power grid (5) and a leakage current circuit (6); the solar photovoltaic array (1), the boosted circuit (2), the DC-AC inverter (3), the relay (4), and the power grid (5) are sequentially connected; the relay (4) and the power grid (5) are connected, and the boosted circuit (2) and the leakage current circuit (6) are connected; and the leakage current circuit (6) and the power grid (5) are connected. The high-efficiency transformer-free single-phase photovoltaic grid-connected inverter can effectively inhibit common mode current, and the highest efficiency of a topological structure can reach 96 percent.
Description
Technical field
The utility model relates to a kind of inverter, relates in particular to a kind of efficient transformerless single-phase photovoltaic grid-connected inverter.
Background technology
Along with the exhaustion day by day of the energy, solar energy has become the potential green energy resource of a kind of very tool, and photovoltaic generation is the current major way that utilizes solar energy.For the photovoltaic combining inverter of grid type, have isolating transformer and without two kinds of topological structures of isolating transformer.For the combining inverter of isolating transformer, usually in grid side, add Industrial Frequency Transformer to realize photovoltaic array DC side and grid side electrical isolation; Also can add high-frequency isolation transformer to realize grid side and DC side electrical isolation in DC side.Because the grid side frequency is low, make the grid side isolating transformer bulky, heavy and expensive.Although the first two topological structure is realized electrical isolation, due to adding of isolating transformer, make the whole efficiency of system descend 1%-2%.Transformerless type combining inverter structure, containing transformer (low frequency and high frequency), does not have efficiency high, the absolute predominance that volume, weight and cost are low.Therefore, increasing commercial photovoltaic combining inverter adopts this road topological structure.But, making, between photovoltaic (PV) and electrical network, electrical connection has been arranged without the isolating transformer combining inverter, common mode current increases greatly, brings potential safety hazard.A problem that adopts transformerless combining inverter to solve is how to eliminate common-mode voltage to form in parasitic capacitance (between PV and the earth) leakage current that loop produces.Germany SMA SunnyBoy company adopts H5 topological structure (Chinese utility model patent number: 200510079923.1), in this topological structure, V1 and V2 are in the positive-negative half-cycle conducting separately of power network current, V4, V5 at the positive half cycle of electrical network with switching frequency modulation, and V2, V5 at the electrical network negative half-cycle with switching frequency modulation.This transless topological structure, can well solve leakage problem; Simultaneously, its peak efficiency reaches 98.1%, and European efficiency reaches 97.7%.Sunways company adopts the HERIC(european patent number: EP 1369985 A2) topological structure,
This topology is the improvement to the full-bridge topology of bipolarity modulation, the AC at full-bridge topology increases a two-way afterflow branch road be comprised of 2 IGBT, make continuous current circuit and DC side disconnect, can effectively solve leakage problem equally, its peak efficiency reaches 96.3%.Document (Transformerless Inverters for Single-phase Photovoltaic Systems[J]. IEEE Transactions on power electronics, 2007,22 (2): 693-697) propose a kind of new topological structure FB-DCBP (full-bridge with dc-bypass), at the line voltage positive half period, switching tube S1, S4 remain conducting, switching tube S5, S6 and S2, S3 alternate conduction; At the line voltage negative half-cycle, switching tube S2, S3 remain conducting, switching tube S5, S6 and S1, S4 alternate conduction.This topological structure has well solved leakage problem, and its peak efficiency can reach 97.4%.
Summary of the invention
The purpose of this utility model is to provide a kind of efficient transformerless single-phase photovoltaic grid-connected inverter, and it can effectively suppress common mode current, and the topological structure peak efficiency can reach 96%.
In order to solve the existing problem of background technology, the utility model is by the following technical solutions: it comprises photovoltaic array 1, booster circuit 2, DC-AC inverter 3, relay 4, electrical network 5 and with leakage current loop 6, photovoltaic array 1, booster circuit 2, DC-AC inverter 3, relay 4 and electrical network 5 are connected successively, relay 4 is connected with electrical network 5, and booster circuit 2 with leakage current loop 6, be connected, with leakage current loop 6, with electrical network 5, be connected.
Solar photovoltaic array 1 in the utility model is the input of single-phase photovoltaic DC-to-AC converter, for whole system comprises control circuit, provides electric energy.By day under the condition of illumination, solar battery array is electric energy by received transform light energy, through the BOOST booster circuit, become interchange (DC-AC) inverter through direct current direct current is converted to interchange, to the electrical network transmission power, at dark, whole system quits work automatically, utilizes relay that output and electrical network are disconnected.
Booster circuit 2 in the utility model is responsible for the input voltage of photovoltaic array is converted to required direct voltage, generally operates in pressure-increasning state, low photovoltaic array input voltage is raised to certain high direct voltage, so that inversion.
DC-AC inverter 3 in the utility model, as the key link of combining inverter, plays a part very crucial to transformation of electrical energy.Make photovoltaic DC-to-AC converter output current and line voltage same-phase by controlling H bridge and continuous current circuit, realize the photovoltaic array maximum power output simultaneously and suppress leakage current, improve the conversion efficiency of whole photovoltaic system.
The utility model can suppress common mode current effectively, and it adopts the HERIC patent to compare with Sunways company, at the few switching tube of AC, but increases a diode rectifier bridge.From controlling, can control less a switching tube, to control simply comparatively speaking, whole efficiency is decline slightly.This topological structure peak efficiency can reach 96%.With employing H bridge+bipolarity modulation, compare, efficiency can improve.The peak efficiency of H bridge+bipolarity modulation can 94.8% left and right.
The accompanying drawing explanation:
Fig. 1 is the utility model transless single-phase photovoltaic grid-connected inverter leakage current loop diagram.
Embodiment:
With reference to Fig. 1, this embodiment is by the following technical solutions: it comprises photovoltaic array 1, booster circuit 2, DC-AC inverter 3, relay 4, electrical network 5 and with leakage current loop 6, photovoltaic array 1, booster circuit 2, DC-AC inverter 3, relay 4 and electrical network 5 are connected successively, relay 4 is connected with electrical network 5, and booster circuit 2 with leakage current loop 6, be connected, with leakage current loop 6, with electrical network 5, be connected.
Solar photovoltaic array 1 in this embodiment is the input of single-phase photovoltaic DC-to-AC converter, for whole system comprises control circuit, provides electric energy.By day under the condition of illumination, solar battery array is electric energy by received transform light energy, through the BOOST booster circuit, become interchange (DC-AC) inverter through direct current direct current is converted to interchange, to the electrical network transmission power, at dark, whole system quits work automatically, utilizes relay that output and electrical network are disconnected.
Booster circuit 2 in this embodiment is responsible for the input voltage of photovoltaic array is converted to required direct voltage, generally operates in pressure-increasning state, low photovoltaic array input voltage is raised to certain high direct voltage, so that inversion.
DC-AC inverter 3 in this embodiment, as the key link of combining inverter, plays a part very crucial to transformation of electrical energy.Make photovoltaic DC-to-AC converter output current and line voltage same-phase by controlling H bridge and continuous current circuit, realize the photovoltaic array maximum power output simultaneously and suppress leakage current, improve the conversion efficiency of whole photovoltaic system.
This embodiment can suppress common mode current effectively, and it adopts the HERIC patent to compare with Sunways company, at the few switching tube of AC, but increases a diode rectifier bridge.From controlling, can control less a switching tube, to control simply comparatively speaking, whole efficiency is decline slightly.This topological structure peak efficiency can reach 96%.With employing H bridge+bipolarity modulation, compare, efficiency can improve.The peak efficiency of H bridge+bipolarity modulation can 94.8% left and right.
Claims (1)
1. an efficient transformerless single-phase photovoltaic grid-connected inverter, it is characterized in that it comprises photovoltaic array (1), booster circuit (2), DC-AC inverter (3), relay (4), electrical network (5) and with leakage current loop (6), photovoltaic array (1), booster circuit (2), DC-AC inverter (3), relay (4) and electrical network (5) are connected successively, relay (4) is connected with electrical network (5), and booster circuit (2) with leakage current loop (6), be connected, with leakage current loop (6), with electrical network (5), be connected.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2012206885448U CN202957614U (en) | 2012-12-14 | 2012-12-14 | High-efficiency transformer-free single-phase photovoltaic grid-connected inverter |
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| Application Number | Priority Date | Filing Date | Title |
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| CN2012206885448U CN202957614U (en) | 2012-12-14 | 2012-12-14 | High-efficiency transformer-free single-phase photovoltaic grid-connected inverter |
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| CN202957614U true CN202957614U (en) | 2013-05-29 |
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| CN2012206885448U Expired - Fee Related CN202957614U (en) | 2012-12-14 | 2012-12-14 | High-efficiency transformer-free single-phase photovoltaic grid-connected inverter |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103904930A (en) * | 2014-04-01 | 2014-07-02 | 燕山大学 | Three-phase seven-switch photovoltaic grid-connected inverter |
| CN104753384A (en) * | 2015-03-19 | 2015-07-01 | 江苏大学 | Improved zero-current converting H6 structural non-isolation photovoltaic grid-connected inverter and control method thereof |
| CN105958526A (en) * | 2016-01-25 | 2016-09-21 | 陕西科技大学 | Single-phase non-isolated photovoltaic grid connected inverter |
-
2012
- 2012-12-14 CN CN2012206885448U patent/CN202957614U/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103904930A (en) * | 2014-04-01 | 2014-07-02 | 燕山大学 | Three-phase seven-switch photovoltaic grid-connected inverter |
| CN104753384A (en) * | 2015-03-19 | 2015-07-01 | 江苏大学 | Improved zero-current converting H6 structural non-isolation photovoltaic grid-connected inverter and control method thereof |
| CN104753384B (en) * | 2015-03-19 | 2017-05-31 | 江苏大学 | A kind of zero-current switching H6 structures non-isolated grid-connected inverter and its control method |
| CN105958526A (en) * | 2016-01-25 | 2016-09-21 | 陕西科技大学 | Single-phase non-isolated photovoltaic grid connected inverter |
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| Date | Code | Title | Description |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20130529 Termination date: 20161214 |
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| CF01 | Termination of patent right due to non-payment of annual fee |