CN201994870U - Non-transformer inverter achieved by switch capacitor - Google Patents
Non-transformer inverter achieved by switch capacitor Download PDFInfo
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- CN201994870U CN201994870U CN2011200439307U CN201120043930U CN201994870U CN 201994870 U CN201994870 U CN 201994870U CN 2011200439307 U CN2011200439307 U CN 2011200439307U CN 201120043930 U CN201120043930 U CN 201120043930U CN 201994870 U CN201994870 U CN 201994870U
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- Prior art keywords
- power switch
- filter
- power
- source electrode
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
- H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
- H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
- H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M7/53—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
- H02M7/537—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters
- H02M7/5387—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters in a bridge configuration
- H02M7/5388—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters in a bridge configuration with asymmetrical configuration of switches
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/12—Arrangements for reducing harmonics from ac input or output
- H02M1/123—Suppression of common mode voltage or current
-
- 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 non-transformer inverter achieved by a switch capacitor, comprising two capacitors, five power switches and a filter; both ends of the first capacitor are respectively connected with the leakage electrode of the first power switch and the second input end of the filter; the source electrode of the first power switch is connected with the leakage electrode of the second power switch, the first end of the second capacitor and the leakage electrode of the fourth power switch, the source electrode of the second power switch is connected with the second end of the first capacitor and the leakage electrode of the third power switch, the source electrode of the third power switch is connected with the second end of the second capacitor and the source electrode of the fifth power switch, and the leakage electrode of the fifth power switch is connected with the source electrode of the fourth power switch and the first input end of the filter. The utility model further discloses an application thereof in a photovoltaic grid power generation system; and the inverter is simple in structure and is capable of effectively inhibiting the current leakage to the ground in the photovoltaic grid power generation system.
Description
Technical field
The utility model relates to power electronic technology direct-current-alternating-current converter field, specifically, relates to a kind of transless type inverter and the application in grid-connected photovoltaic system thereof.
Background technology
In recent years, the pollution of shortage of energy sources and environment has become the focus in the world, and the development of regenerative resource and application are subjected to the extensive concern of countries in the world.Solar energy cleaning, extensively and reserves huge, be one of comparatively desirable regenerative resource.
Parallel network power generation is one of important form of utilizing solar energy.The direct current that photovoltaic cell produces flows to electrical network after inverter converts alternating current to.According to the configuration difference of transformer in the inverter, it can be divided into band Industrial Frequency Transformer type, band high frequency transformer type and transless type.Industrial Frequency Transformer is bulky, and the cost height is installed inconvenient.Although the high frequency transformer volume and weight reduces greatly, often need to increase the one-level power inverter, cause system complexity to improve, efficient reduces.Transless type inverter is simple owing to its system configuration, the efficient height, and volume is little, and low cost and other advantages has worldwide obtained development fast.
Yet, in transless type grid-connected photovoltaic system, there is inevitable parasitic capacitance between photovoltaic cell and the earth, may cause Ground leakage current to occur.Ground leakage current will reduce the quality of power supply, and may cause electromagnetic compatibility and safety problem, therefore need be inhibited.
Current, generally adopt the full-bridge inverter and the half-bridge inverter of bipolarity modulation to solve the common mode current problem.But these two kinds of solutions respectively have its weak point.The full-bridge inverter output voltage of bipolarity modulation is two level, needs bigger output inductor with inhibition switch ripple, thereby has increased volume, cost and the loss of system.It is the twice of full-bridge inverter that half-bridge circuit requires the size of its DC side input voltage, the corresponding ratio of boosting and the design difficulty that has increased the quantity of prime direct current input source series connection or improved prime DC/DC booster circuit.
Summary of the invention
The utility model provides a kind of DC input voitage simple in structure, that can effectively suppress Ground leakage current, needs in the transless type photovoltaic parallel in system identical with full-bridge inverter and support the switching capacity of three level output to realize that transless type inverter and this switching capacity realize the application of transless type inverter in grid-connected photovoltaic system.
A kind of switching capacity is realized transless type inverter, and its internal circuit comprises: first electric capacity, second electric capacity, first power switch, second power switch, the 3rd power switch, the 4th power switch, the 5th power switch and filter; First end of first electric capacity and first power switch drain electrode link to each other, first power switch source electrode and the drain electrode of second power switch, first end of second electric capacity links to each other with the drain electrode of the 4th power switch, the source electrode of second power switch links to each other with second end of first electric capacity and the drain electrode of the 3rd power switch, the source electrode of the 3rd power switch links to each other with second end of second electric capacity and the source electrode of the 5th power switch, the drain electrode of the 5th power switch links to each other with the source electrode of the 4th power switch, the drain electrode of the 5th power switch links to each other with the first input end of filter, and second end of first electric capacity links to each other with second input of filter.
Described filter is inductive type filter, inductor-capacitor mode filter or inductor-capacitor-inductive type filter.
Described power switch constitutes after by independent power transistor and separate diode inverse parallel, or is made of the power transistor that its inside carries anti-and diode.
Described power transistor is power metal oxide semiconductor field-effect transistor, igbt or other full-control type power semiconductors.
Switching capacity of the present utility model realizes that transless type inverter has two kinds of modulation systems: unipolar pulse width modulated and the pulse width modulation of frequency multiplication formula.
When adopting the unipolar pulse width modulation mode, when power frequency (for example 50Hz) when modulating wave is in positive half period, first power switch and the 3rd power switch conducting, second power switch turn-offs, and the 4th power switch and the 5th power switch are done complementary HF switch action; When the power frequency modulating wave was in negative half-cycle, the 4th power switch turn-offed, the 5th power switch conducting, and first power switch and the 3rd power switch are done synchronous HF switch action, and first power switch and second power switch are done complementary HF switch action.
When adopting frequency multiplication formula pulse width modulation, first power switch, second power switch, the 3rd power switch, the 4th power switch and the 5th power switch all carry out switch motion with high frequency period, but the power frequency modulating wave of first power switch, second power switch and the 3rd power switch is opposite with the power frequency modulating wave phase place of the 4th power switch and the 5th power switch.
No matter adopt above-mentioned any modulation system, the control signal of all power switchs all satisfies following relation: the control signal sequential of first power switch and the 3rd power switch is identical, the control signal sequential of first power switch and second power switch is complementary and the Dead Time of common shutoff arranged, and the control signal sequential of the 4th power switch and the 5th power switch is complementary and the Dead Time of common shutoff arranged.
Described unipolar pulse width modulation mode makes inverter can export three level, thereby reduces filter inductance; Described frequency multiplication formula pulse width modulation can double the equivalent switching frequency of inverter output voltage under the constant prerequisite of the operating frequency of single power switch on the described unipolar pulse width modulation mode basis, thereby make outputting inductance further reduce, and then reduce cost, reduce volume and weight and reduce copper loss and the magnetic loss that produces on the filter inductance.
Switching capacity of the present utility model is realized transless type inverter applicable to self inverter and grid type inverter system, and is particularly suitable for being applied in the grid-connected photovoltaic system.
Switching capacity of the present utility model realizes that transless type inverter applications is when grid-connected photovoltaic system, the positive pole of DC power supply links to each other with first end of first electric capacity, the negative pole of DC power supply links to each other with second end of first electric capacity, the live wire of electrical network links to each other with first output of filter, and the zero line of electrical network links to each other with second output of filter; Import described unipolar pulse width modulated or frequency multiplication formula pulse width modulating signal to the control end of first power switch, second power switch, the 3rd power switch, the 4th power switch and the 5th power switch respectively then, turning on and off of the corresponding switching tube of control institute, the direct current energy on the realization DC power supply converts AC energy to and is delivered to electrical network.Because the parasitic capacitance between photovoltaic cell pole plate and the earth is by the transmission pressure short circuit, Ground leakage current is eliminated fully.
The DC input voitage that switching capacity realization transless type inverter of the present utility model needs is identical with full-bridge inverter, than half-bridge circuit or neutral point clamp half-bridge circuit, only need the DC input voitage of half, thereby reduced the quantity of prime direct current input source series connection or reduced the ratio of boosting of prime DC/DC booster circuit.
Switching capacity of the present utility model realizes that transless type inverter structure is simple, and it is identical with full-bridge inverter and support three level to export effectively to suppress the DC input voitage of Ground leakage current, needs in the transless type photovoltaic parallel in system.
Description of drawings
Fig. 1 is the circuit diagram that the utility model switching capacity is realized transless type inverter.
Fig. 2 a-Fig. 2 c is the schematic diagram that the utility model switching capacity is realized three kinds of filter constructions in the transless type inverter.
Fig. 3 is the waveform schematic diagram that the utility model adopts the unipolarity pulse width modulation mode.
Fig. 4 is the waveform schematic diagram that the utility model adopts frequency multiplication formula pulse width modulation mode.
Fig. 5 a-Fig. 5 d is four kinds of mode of operation schematic diagrames that the utility model switching capacity is realized transless type inverter.
Embodiment
Referring to accompanying drawing 1, switching capacity of the present utility model realizes that transless type inverter comprises first capacitor C
1, second capacitor C
2, the first power switch S
1, the second power switch S
2, the 3rd power switch S
3, the 4th power switch S
4, the 5th power switch S
5With filter F.
The described power switch S of present embodiment
1-S
5By power transistor T
1-T
5With anti-and diode D
1-D
5Compose in parallel respectively, the drain electrode of power transistor or collector electrode link to each other with the negative electrode of anti-and diode and constitute the drain electrode of power switch, and the source electrode of power transistor or emitter link to each other with the anode of anti-and diode and constitute the source electrode of power switch.
First capacitor C
1First end and the first power switch S
1Drain electrode link to each other the first power switch S
1The source electrode and the second power switch S
2Drain electrode, second capacitor C
2First end and the 4th power switch S
4Drain electrode link to each other the second power switch S
2The source electrode and first capacitor C
1Second end and the 3rd power switch S
3Drain electrode link to each other the 3rd power switch S
3The source electrode and second capacitor C
2Second end and the 5th power switch S
5Source electrode link to each other the 5th power switch S
5Drain electrode and the 4th power switch S
4Source electrode link to each other the 5th power switch S
5Drain electrode link to each other first capacitor C with the first input end of filter F
1Second end link to each other with second input of filter F.V among the figure
DcBe DC side input voltage, i
AcBe the AC side output current.
DC power supply and electrical network are inserted described inverter, wherein the positive pole of DC power supply and first capacitor C
1First end link to each other the negative pole of DC power supply and first capacitor C
1Second end link to each other, the live wire of electrical network links to each other with first output of filter F, the zero line of electrical network links to each other with second output of filter F; Then by drive circuit respectively to the first power switch S
1, the second power switch S
2, the 3rd power switch S
3, the 4th power switch S
4With the 5th power switch S
5The control end input control signal, the turning on and off of the corresponding switching tube of control institute realizes that direct current energy on the DC power supply converts AC energy to and carries electrical network, guarantees simultaneously because of inverter work generation Ground leakage current.
Fig. 2 a-Fig. 2 c has specifically provided three kinds of different composition modes of filter F.
Fig. 2 a has provided the inductive type filter.Filter inductance L wherein
fFirst end link to each other filter inductance L with the first input end of filter F
fSecond end link to each other with first output of filter F, second input of filter F then directly links to each other with second output.
Fig. 2 b has provided the inductor-capacitor mode filter.Filter inductance L wherein
fFirst end link to each other filter inductance L with the first input end of filter F
fSecond end link to each other filter capacitor C with first output of filter F
fFirst end link to each other with second output with first output of filter F respectively with second end, second input of filter F then directly links to each other with second output.
Fig. 2 c has provided inductor-capacitor-inductive type filter.The first filter inductance L wherein
F1First end link to each other the first filter inductance L with the first input end of filter F
F1Second end and the second filter inductance L
F2First end and filter capacitor C
fFirst end link to each other the second filter inductance L
F2Second end link to each other filter capacitor C with first output of filter F
fSecond end link to each other with second output of filter F, second input of filter F then directly links to each other with second output.
Switching capacity of the present utility model realizes that transless type inverter has two kinds of modulation systems: unipolar pulse width modulated and the pulse width modulation of frequency multiplication formula.
Accompanying drawing 3 is the waveform schematic diagram that adopts the unipolarity pulse width modulation mode, wherein u
cBe high frequency (for example 20kHz) carrier wave, u
gIt is power frequency (for example 50Hz) modulating wave.As power frequency modulating wave u
gWhen being in positive half period, the first power switch S
1With the 3rd power switch S
3Conducting, the second power switch S
2Turn-off the 4th power switch S
4With the 5th power switch S
5Do complementary HF switch action; As power frequency modulating wave u
gWhen being in negative half-cycle, the 4th power switch S
4Turn-off the 5th power switch S
5Conducting, the first power switch S
1With the 3rd power switch S
3Do synchronous HF switch action, the first power switch S
1With the second power switch S
2Do complementary HF switch action.
Referring to accompanying drawing 5a-accompanying drawing 5d, there are 4 kinds of mode of operations at most in transless type inverter of the present utility model in entire work process.
When mode of operation 1 (referring to accompanying drawing 5a), the first power switch S
1, the 3rd power switch S
3With the 4th power switch S
4Be in conducting state, the second power switch S
2With the 5th power switch S
5Be in off state, inverter output positive level, second capacitor C simultaneously
2Be recharged until its both end voltage identical with DC input voitage.
When mode of operation 2 (referring to accompanying drawing 5b), the first power switch S
1, the 3rd power switch S
3With the 5th power switch S
5Be in conducting state, the second power switch S
2With the 4th power switch S
4Be in off state, inverter output zero level, second capacitor C simultaneously
2Be recharged until its both end voltage identical with DC input voitage.
When mode of operation 3 (referring to accompanying drawing 5c), the second power switch S
2With the 5th power switch S
5Be in conducting state, the first power switch S
1, the 3rd power switch S
3With the 4th power switch S
4Be in off state, because in second capacitor C
2When mode of operation 1 and mode of operation 2, be recharged, and its voltage approximate constant in a switch periods, inverter output negative level.
When mode of operation 4 (referring to accompanying drawing 5d), the second power switch S
2With the 4th power switch S
4Be in conducting state, the first power switch S
1, the 3rd power switch S
3With the 5th power switch S
5Be in off state, inverter output zero level.
When all power switchs were debugged the control signal work that provides according to debugging of unipolar pulse width or double frequency pulse width, inverter constantly switched between above-mentioned four kinds of mode of operations, thereby realizes the conversion of direct current energy to AC energy.
The described power switch of present embodiment can carry the anti-also switching transistor of diode by its inside and constitute, also can be by constituting after independent switch transistor and the separate diode inverse parallel; Described switching transistor can be power metal oxide silicon field effect transistor (Metal Oxide SemiconductorField-effect Transistor, MOSFET) or the insulation bipolar transistor (Insulated Gate BipolarTransistor IGBT) waits the full-control type power semiconductor; Described filter F is the inductive type filter, also can be substituted by inductor-capacitor mode filter or inductor-capacitor-inductive type filter; The described transless type of present embodiment inverter structure both had been applicable to that the grid type inverter also was applicable to self inverter structure or other transless type inversion occasions.
Claims (5)
1. a switching capacity is realized transless type inverter, it is characterized in that, comprising: the first electric capacity (C
1), the second electric capacity (C
2), the first power switch (S
1), the second power switch (S
2), the 3rd power switch (S
3), the 4th power switch (S
4), the 5th power switch (S
5), filter (F); The described first electric capacity (C
1) first end and the first power switch (S
1) drain electrode link to each other the first power switch (S
1) the source electrode and the second power switch (S
2) drain electrode, the second electric capacity (C
2) first end and the 4th power switch (S
4) drain electrode link to each other the second power switch (S
2) the source electrode and the first electric capacity (C
1) second end and the 3rd power switch (S
3) drain electrode link to each other the 3rd power switch (S
3) the source electrode and the second electric capacity (C
2) second end and the 5th power switch (S
5) source electrode link to each other the 5th power switch (S
5) drain electrode and the 4th power switch (S
4) source electrode link to each other; The 5th power switch (S
5) drain electrode link to each other the first electric capacity (C with the first input end of filter (F)
1) second end link to each other with second input of filter (F).
2. switching capacity as claimed in claim 1 is realized transless type inverter, it is characterized in that, described power switch is made up of power transistor and anti-also diode, the drain electrode of power transistor or collector electrode link to each other with the negative electrode of anti-and diode and constitute the drain electrode of power switch, and the source electrode of power transistor or emitter link to each other with the anode of anti-and diode and constitute the source electrode of power switch.
3. switching capacity as claimed in claim 2 is realized transless type inverter, it is characterized in that described power transistor is power metal oxide semiconductor field-effect transistor or igbt.
4. switching capacity as claimed in claim 2 is realized transless type inverter, it is characterized in that, described anti-also diode is the diode that separate diode or power transistor inside carry.
5. switching capacity as claimed in claim 1 is realized transless type inverter, it is characterized in that described filter (F) is inductive type filter, inductor-capacitor mode filter or inductor-capacitor-inductive type filter.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011200439307U CN201994870U (en) | 2011-02-21 | 2011-02-21 | Non-transformer inverter achieved by switch capacitor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011200439307U CN201994870U (en) | 2011-02-21 | 2011-02-21 | Non-transformer inverter achieved by switch capacitor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201994870U true CN201994870U (en) | 2011-09-28 |
Family
ID=44671344
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2011200439307U Expired - Lifetime CN201994870U (en) | 2011-02-21 | 2011-02-21 | Non-transformer inverter achieved by switch capacitor |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN201994870U (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102088252A (en) * | 2011-02-21 | 2011-06-08 | 浙江大学 | Inverter without transformer realized by switched capacitor and applications of inverter |
| CN109980978A (en) * | 2019-04-01 | 2019-07-05 | 安徽工业大学 | A kind of converter and its modulator approach |
| US11228257B2 (en) | 2018-05-04 | 2022-01-18 | Aalborg Universitet | Power circuits for modular multi-level converters (MMC) and modular multi-level converters |
-
2011
- 2011-02-21 CN CN2011200439307U patent/CN201994870U/en not_active Expired - Lifetime
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102088252A (en) * | 2011-02-21 | 2011-06-08 | 浙江大学 | Inverter without transformer realized by switched capacitor and applications of inverter |
| US11228257B2 (en) | 2018-05-04 | 2022-01-18 | Aalborg Universitet | Power circuits for modular multi-level converters (MMC) and modular multi-level converters |
| CN109980978A (en) * | 2019-04-01 | 2019-07-05 | 安徽工业大学 | A kind of converter and its modulator approach |
| CN109980978B (en) * | 2019-04-01 | 2020-05-05 | 安徽工业大学 | Converter and modulation method thereof |
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|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| AV01 | Patent right actively abandoned |
Granted publication date: 20110928 Effective date of abandoning: 20130306 |
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| AV01 | Patent right actively abandoned |
Granted publication date: 20110928 Effective date of abandoning: 20130306 |
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| RGAV | Abandon patent right to avoid regrant |