CN105978376A - Grid-connected inverter circuit and control method thereof - Google Patents

Grid-connected inverter circuit and control method thereof Download PDF

Info

Publication number
CN105978376A
CN105978376A CN201610519063.7A CN201610519063A CN105978376A CN 105978376 A CN105978376 A CN 105978376A CN 201610519063 A CN201610519063 A CN 201610519063A CN 105978376 A CN105978376 A CN 105978376A
Authority
CN
China
Prior art keywords
inverter
grid
branch road
voltage
switching tube
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.)
Granted
Application number
CN201610519063.7A
Other languages
Chinese (zh)
Other versions
CN105978376B (en
Inventor
文安
卢亮宇
魏承志
饶宏
曾勇刚
牟敏
杨俊权
赵曼勇
许树楷
刘琨
黄维芳
金鑫
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
CSG Electric Power Research Institute
China Southern Power Grid Co Ltd
Research Institute of Southern Power Grid Co Ltd
Original Assignee
China Southern Power Grid Co Ltd
Research Institute of Southern Power Grid Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by China Southern Power Grid Co Ltd, Research Institute of Southern Power Grid Co Ltd filed Critical China Southern Power Grid Co Ltd
Priority to CN201610519063.7A priority Critical patent/CN105978376B/en
Publication of CN105978376A publication Critical patent/CN105978376A/en
Application granted granted Critical
Publication of CN105978376B publication Critical patent/CN105978376B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02MAPPARATUS 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
    • H02M7/00Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/42Conversion of dc power input into ac power output without possibility of reversal
    • H02M7/44Conversion of dc power input into ac power output without possibility of reversal by static converters
    • H02M7/48Conversion 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
    • H02M7/483Converters with outputs that each can have more than two voltages levels
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02JCIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00Circuit arrangements for ac mains or ac distribution networks
    • H02J3/38Arrangements for parallely feeding a single network by two or more generators, converters or transformers
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02MAPPARATUS 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
    • H02M7/00Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/42Conversion of dc power input into ac power output without possibility of reversal
    • H02M7/44Conversion of dc power input into ac power output without possibility of reversal by static converters
    • H02M7/48Conversion 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
    • H02M7/53Conversion 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
    • H02M7/537Conversion 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

Abstract

The invention provides a grid-connected inverter circuit and a control method thereof. The grid-connected inverter circuit comprises an inverter, an (N+1)-port transformer, a 2N-phase rectifier, 2N voltage dividing capacitors and a (2N+1)-end inverter; direct-current voltage is subjected to high-frequency inversion via the inverter to generate high-frequency square wave, the high-frequency square wave passes through the (N+1)-port transformer to boost the voltage into voltage of N voltage levels, the square wave of the N voltage levels is respectively rectified to form voltage of 2N different levels, the voltage of 2N different levels and a zero potential grounding point form (2N+1) level branches, the levels are isolated by the capacitors connected in series longitudinally and charge the capacitors, and the (2N+1) level branches are respectively connected with the (2N+1)-end inverter. The whole circuit adopts multi-level inversion, so that the content of output harmonic is greatly reduced, additional high-capacity filters are not needed, and the structure is simple.

Description

Grid-connected inverter circuit and control method thereof
Technical field
The present invention relates to electric and electronic technical field, particularly relate to grid-connected inverter circuit and control method thereof.
Background technology
In recent years, along with photovoltaic generation, Large Copacity energy storage device, electric automobile, Technology of HVDC based Voltage Source Converter Development, have increasing need for a kind of safe and efficient, low cost, combining inverter that output harmonic wave content is low.
Tradition combining inverter is divided into isolated form and non-isolation type.Non-isolation type can produce common mode electric leakage over the ground Stream, and easily inject DC component to electrical network.Isolation type grid-connected inverter division of labor frequency and high frequency two kinds, all First becoming to exchange again through transformer boost by DC inversion, but Industrial Frequency Transformer exists volume weight greatly, noise is high, The shortcomings such as efficiency is low.
High-frequency inverter is divided into DC (direct current)/DC changing type High Frequency Link combining inverter and cycle changing type high Frequently chain combining inverter, difference is that the high frequency square wave after boosting is first passed through rectification by the former, is more just reverse into String ripple;High frequency square wave after boosting directly is controlled directly to export industrial-frequency alternating current by the latter through frequency converter, The latter uses two level or the modulation system of three level.
Conventional photovoltaic is grid-connected or the inversion end such as DC transmission engineering applies two level PWMs mostly (Pulse-Width Modulation, pulsewidth modulation) pulsewidth modulation, or MMC (Modular Multilevel Converter, modularization multi-level converter) the modular multilevel change of current.Two level or three-level modulation Cost is relatively low, but can produce a large amount of harmonic wave, needs Large Copacity wave filter to be filtered.
Summary of the invention
Based on this, it is necessary to for the problem that general combining inverter structure is complicated and output harmonic wave content is high, A kind of simple in construction and the low grid-connected inverter circuit of output harmonic wave content are provided.
A kind of grid-connected inverter circuit, including inverter, N+1 port transformer, 2N commutating phase device, 2N Derided capacitors and 2N+1 end inverter, wherein, N is the positive integer more than or equal to 2;
The direct-flow input end of inverter is connected with external dc power, the ac output end of inverter and N+1 end Winding of mouth transformator connects, the Secondary Winding of N+1 port transformer and the input of 2N commutating phase device Connect, 2N commutating phase device output 2N+1 bar branch road, 2N+1 bar branch road is parallel with list between adjacent two branch roads Individual derided capacitors, 2N+1 bar branch road is connected respectively to 2N+1 end inverter input terminal, and 2N+1 end inverter is defeated Going out end to be connected with external electrical network, 2N commutating phase device output 2N+1 bar branch road includes single ground connection branch road.
A kind of control method of above-mentioned grid-connected inverter circuit, including step:
It is modulated controlling to the high frequency square wave of inverter output;
Magnitude of voltage in Real-time Collection 2N+1 bar branch road;
Calculate the average voltage of adjacent two branch roads in 2N+1 bar branch road;
Input modulating wave is to 2N+1 end inverter, when modulating wave is more than the n-th branch road and the voltage of the (n+1)th branch road Meansigma methods and during less than the average voltage of the (n+1)th branch road and the n-th+2 branch road, turns on 2N+1 end inverter the The power switch pipe of n branch road;
Wherein, n is integer, and n is less than or equal to 2N-1 more than or equal to 1.
Grid-connected inverter circuit of the present invention, including inverter, N+1 port transformer, 2N commutating phase device, 2N Individual derided capacitors and 2N+1 end inverter, DC voltage realizes high-frequency inversion through inversion electrical equipment, generates height Frequently square wave, square-wave voltage boosting, through N+1 port transformer, is formed N number of electric pressure by high frequency square wave Voltage, more respectively the square wave of N number of electric pressure is carried out rectification, form the voltage of 2N varying level, Add zero potential earth point, form 2N+1 level branch road, by lontitudinal series between level and level Capacitor is isolated, and is charged capacitor, and 2N+1 level branch road is respectively with 2N+1 end inverter even Connecing, whole circuit uses multi-level inverse conversion, greatly reduces output harmonic wave content, it is not necessary to additional configuration is big Capacity wave filter, simple in construction.
Additionally the present invention also provides for the control method of a kind of above-mentioned grid-connected inverter circuit, the height to inverter output Frequently square wave is modulated controlling, and the magnitude of voltage in Real-time Collection 2N+1 bar branch road calculates in 2N+1 bar branch road The average voltage of adjacent two branch roads, input modulating wave to 2N+1 end inverter, when modulating wave is more than the n-th branch road With the average voltage of the (n+1)th branch road and during less than the average voltage of the (n+1)th branch road and the n-th+2 branch road, The power switch pipe of conducting 2N+1 end inverter the n-th branch road.During whole, use high frequency square wave inversion control System and voltage with multiple levels inversion control, it is achieved the good control to grid-connected inverter circuit.
Accompanying drawing explanation
Fig. 1 is the structural representation of first embodiment of grid-connected inverter circuit of the present invention;
Fig. 2 is the structural representation of second embodiment of grid-connected inverter circuit of the present invention;
Fig. 3 is the structural representation of 3rd embodiment of grid-connected inverter circuit of the present invention;
Fig. 4 is the structural representation of 4th embodiment of grid-connected inverter circuit of the present invention;
Fig. 5 be grid-connected inverter circuit of the present invention be high-frequency isolation type 11 level self coupling transformation grid-connected inverter circuit Time output the 9th level the first transient current flow to schematic diagram;
Fig. 6 be grid-connected inverter circuit of the present invention be high-frequency isolation type 11 level self coupling transformation grid-connected inverter circuit Time output the 9th level the second transient current flow to schematic diagram;
Fig. 7 be grid-connected inverter circuit of the present invention control method in single-phase inverter high frequency square wave modulation principle figure Schematic diagram;
Fig. 8 is the power switch pipe conducting letter using the control method modulation of grid-connected inverter circuit of the present invention to produce Number schematic diagram.
Detailed description of the invention
As it is shown in figure 1, a kind of grid-connected inverter circuit, including inverter 100, N+1 port transformer 200, 2N commutating phase device 300,2N derided capacitors 400 and 2N+1 end inverter 500, wherein, N is big In or equal to 2 positive integer;
The direct-flow input end of inverter 100 is connected with external dc power, the ac output end of inverter 100 It is connected with a winding of N+1 port transformer 200, the Secondary Winding of N+1 port transformer 200 and 2N The input of commutating phase device 300 connects, and 2N commutating phase device 300 exports 2N+1 bar branch road, 2N+1 bar branch road In be parallel with single derided capacitors 400 between adjacent two branch roads, 2N+1 bar branch road is connected respectively to 2N+1 end Inverter 500 input, 2N+1 end inverter 500 outfan is connected with external electrical network, 2N commutating phase device 300 output 2N+1 bar branch roads include single ground connection branch road.
Inverter 100 becomes to N+1 port for the unidirectional current that outside inputs is converted into high-frequency alternating current output Depressor 200, specifically, inverter 100 can select full-bridge inverter.As in figure 2 it is shown, full-bridge inverting Device include the first switching tube, second switch pipe, the 3rd switching tube, the 4th switching tube, the first diode, Two diodes, the 3rd diode and the 4th diode, the first switching tube and the first diode inverse parallel, the Two switching tubes and the second diode inverse parallel, the 3rd switching tube and the 3rd diode inverse parallel, the 4th switching tube With the 4th diode inverse parallel, the first switching tube connects with second switch pipe, the 3rd switching tube and the 4th switch Pipe is connected, and the positive pole respectively with external dc power of the drain electrode with the 3rd switching tube that drains of the first switching tube connects Connecing, the source electrode of second switch and the source electrode of the 4th switching tube are connected with the negative pole of external dc power respectively.Can Full-bridge inverter to be carried out high frequency square wave control, specifically, upper and lower two can be controlled in full-bridge inverter Individual power switch pipe turns on and off at equal intervals, opens interval mutual deviation 180 degree, is consequently formed high electronegative potential High frequency square wave.
N+1 port transformer 200 has N+1 port, and it has a winding and Secondary Winding, wherein One time winding is connected with inverter 100 AC, and Secondary Winding is connected with 2N commutating phase device 300.Concrete next Saying, N+1 port transformer 200 can select high frequency auto N+1 port transformer, high frequency auto N+1 end The volume mass of mouth transformator is little, and transformator plays boosting and obtains the effect of multiple voltage, Secondary Winding side Often increasing the output that port can increase by two level a pair, output branch road connects load, therefore transformation in turn Device total capacity is fully used, thus reduces cost.
2N commutating phase device 300 can select 2N phase full-bridge rectifier specifically, and it has upper and lower two bridges Arm, further for, nature turn-off type 2N phase full-bridge rectifier can be selected.Middle rectification link uses Natural turn-off type device, it is not necessary to control, reduces control complexity, when shutoff opened by minimizing device simultaneously Unnecessary loss, can obtain many level direct voltage.2N commutating phase device 300 exports 2N+1 bar branch road, Wherein 2N bar branch road is common output branch road, and also a branch road is the branch road of earth point.
2N derided capacitors 400 is parallel between the 2N+1 bar branch road of 2N commutating phase device 300 output respectively.
As in figure 2 it is shown, 2N+1 end inverter 500 includes that at least 2N+1 power switch pipe is (every in Fig. 2 1 switching tube only drawn by bar branch road, with signal), arrangement from down to up is followed successively by V (1) to V (2N+1), merit The drain electrode of rate switching tube is connected with branch road, and the source electrode of 2N+1 power switch pipe connects and same bus jointly, female Line output is grid-connected, and 2N+1 bar branch road B (1) to B (2N+1) can connect one or more power switch respectively Managing, direction voltage and the actual backward voltage born that its quantity can bear according to each switching tube determine, Bearing voltage the biggest, the switching tube quantity of series connection is the most.
Grid-connected inverter circuit of the present invention, including inverter 100, N+1 port transformer 200,2N commutating phase Device 300,2N derided capacitors 400 and 2N+1 end inverter 500, DC voltage is real through inversion electrical equipment Existing high-frequency inversion, generates high frequency square wave, and high frequency square wave is through N+1 port transformer 200, by square-wave voltage Boosting forms the voltage of N number of electric pressure, more respectively the square wave of N number of electric pressure is carried out rectification, is formed The voltage of 2N varying level, adds zero potential earth point, forms 2N+1 level branch road, level with Isolated by the capacitor of lontitudinal series between level, and capacitor is charged, 2N+1 level branch road Being connected with 2N+1 end inverter 500 respectively, whole circuit uses multi-level inverse conversion, greatly reduces output humorous Ripple content, it is not necessary to additional configuration Large Copacity wave filter, simple in construction.
As in figure 2 it is shown, wherein in an embodiment, grid-connected inverter circuit of the present invention also includes DC source 600。
For concrete structure and the beneficial effect thereof of of the present invention grid-connected inverter circuit are further discussed in detail, below Multiple for employing examples are described in detail.
Example one, N=3, inverter is full-bridge inverter, and N+1 port transformer is high frequency auto N+1 end Mouth transformator, 2N commutating phase device is 2N phase full-bridge rectifier, and 2N+1 end inverter includes that 2N+1 is opened Guan Guan, i.e. in this specific embodiment, grid-connected inverter circuit is that high-frequency isolation type seven level self coupling transformation is grid-connected Inversion single-phase circuit.
As in figure 2 it is shown, high-frequency isolation type seven level self coupling transformation parallel network reverse single-phase circuit includes being sequentially connected with DC source 600, full-bridge inverter 100, high frequency auto N+1 port transformer 200,2N phase full-bridge Commutator 300,2N derided capacitors 400,2N+1 end single-phase inverter 500, wherein, DC source 600 It is connected with full-bridge inverter 100 medium-high frequency half-bridge inverter Partial DC side two brachium pontis, high frequency half bridge inverter AC outfan is connected with a winding of high frequency N+1 port autotransformer 200, high frequency N+1 port The Secondary Winding of autotransformer 200 is connected with 2N phase full-bridge rectifier 300 input, and 2N phase full-bridge is whole Stream device 300 exports 2N bar branch road and forms 2N+1 bar branch road plus earth point, with one between adjacent two branch roads Derided capacitors 400 connects, and 2N+1 end is connected respectively to 2N+1 end single-phase inverter 500 input, 2N+1 again End single-phase inverter 500 outfan is connected to same bus and connects electrical network.
Embodiment two, N=3, inverter is full-bridge inverter, and N+1 port transformer is high frequency auto N+1 Port transformer, 2N commutating phase device is 2N phase full-bridge rectifier, 2N+1 end inverter and outside three-phase alternating current System connects, and 2N+1 end inverter includes 3* (2N+1) individual switching tube, i.e. in this specific embodiment, Grid-connected inverter circuit is high-frequency isolation type seven level self coupling transformation parallel network reverse three-phase circuit.
As it is shown on figure 3, high-frequency isolation type seven level self coupling transformation parallel network reverse three-phase circuit and above-described embodiment The difference of a kind of seven level single-phase inversion circuit (embodiment one Fig. 2) is, the 2N+1 (seven) provided End single-phase inverter 2N+1 (seven) end three-phase inverter 100 replaces, and it is connected to export A, B, C tri- Connect three-phase alternating current system.2N+1 (seven) end three-phase inverter 100 DC side connects seven DC level branch roads, Respectively the most again and ter power switch pipe, export and be connected to AC system A, B, C three-phase bus.Wherein, Positive DC level branch road connects its corresponding drain electrode of power switch pipe, source electrode is connected with AC system;Negative pole DC level branch road connects it and is connected source electrode, the drain electrode of corresponding power switching tube with AC system.Three-phase is also During net shorter than single-phase inversion circuit, the most directly due to every DC level side voltage-dividing capacitor discharge and recharge time interval Stream side voltage is more stable.
Embodiment three, N=5, inverter is full-bridge inverter, and N+1 port transformer is high frequency auto N+1 Port transformer, 2N commutating phase device is 2N phase full-bridge rectifier, 2N+1 end inverter and outside three-phase alternating current System connects, and 2N+1 end inverter includes 2N+1 switching tube, i.e. in this specific embodiment, grid-connected Inverter circuit is high-frequency isolation type 13 level self coupling transformation parallel network reverse single-phase circuit.
As shown in Figure 4, high-frequency isolation type 11 level self coupling transformation parallel network reverse single-phase circuit and seven level lists The difference of phase inverter circuit (embodiment one Fig. 2) is, the secondary side outfan of its high frequency auto transformator increases Add two pairs of ports (N becomes 5 from 3), then connect 2 full-bridge rectifiers, 4 unidirectional currents of multi output respectively Flat branch road, 4 derided capacitors of corresponding increase and four power switch pipes, its connected mode is identical with Fig. 2. In like manner, can increase the output port of high frequency auto transformator to produce more level, DC level number is the most, It is the fewest that it exchanges grid-connected side output harmonic wave content.
To be that high-frequency isolation type 11 level self coupling transformation is grid-connected with embodiment three, i.e. grid-connected inverter circuit below Inversion single-phase circuit, current trend in whole circuit work process.
Fig. 5 and Fig. 6 is respectively high-frequency isolation type 11 level self coupling transformation grid-connected inverter circuit output the 9th electricity Two kinds of transient current flow graphs at ordinary times, as shown in heavy black line and the direction of arrow in Fig. 5 and Fig. 6.When entirely During bridge inverter 100 power switch pipe VD2 and VD3 conducting, as it is shown in figure 5, electric current bridge from commutator Arm AC flows into, and from commutator, brachium pontis AC flows out, through naturally turning off diode pair DC level Prop up the charging of trackside voltage-dividing capacitor, the 9th DC level branch switch pipe conducting, power to AC system.When During full-bridge inverter 100 power switch pipe VD1 and VD4 conducting, as shown in Figure 6, electric current is from commutator Brachium pontis AC flows into, and from commutator, brachium pontis AC flows out, through naturally turning off diode pair unidirectional current Flat trackside voltage-dividing capacitor charging, and flow through the 9th DC level branch switch pipe, power to AC system.
In general, grid-connected inverter circuit of the present invention has the following technical effect that
1, using isolation high frequency auto transformator, volume mass is little, and transformator plays boosting and obtains multiple electricity The effect of pressure, secondary side often increases by a pair output that port can increase by two level, and output branch road connects in turn Logical load, therefore transformator total capacity is fully used, thus reduces cost.
2, middle rectification link uses nature turn-off type device, it is not necessary to controls, reduces control complexity, Decrease device simultaneously and open loss unnecessary during shutoff.Obtain many level direct voltage simultaneously;Inverter side Power switch pipe is operated in power frequency state, it is possible to reduce loss.
3, multi-level inverse conversion greatly reduces output harmonic wave content, it is not necessary to additional configuration Large Copacity wave filter, Reduce floor space and investment.
4, comparing traditional multi-level inverter N bar branch road and can only export the level number of most N/2, inversion exports Every, side branch road can export a level, and the device count that electric current flows through also greatly reduces, thus significantly reduces Loss and device cost.
Additionally the present invention also provides for the control method of a kind of such as above-mentioned grid-connected inverter circuit, including step:
Step one: be modulated controlling to the high frequency square wave of inverter output.
With reference to Fig. 7, high frequency square wave modulation principle figure, using two frequencies is 1KHz, amplitude 2 π, phase place The triangular wave of phase difference of pi is carrier wave Twave1 and carrier wave Twave2, such as dotted line and shown in solid in Fig. 7, adopts Being modulating wave M by a DC level, its amplitude is adjustable from π to 2 π, when triangular carrier Twave1 is more than adjusting During ripple processed, power switch pipe VD1 and VD4 in conduction inverter, when triangular carrier Twave2 is more than modulation During ripple, power switch pipe VD2 and VD3 in conduction inverter, for preventing VD1 and VD2, VD3 and VD4 simultaneously turns on and causes the short circuit of low-voltage DC source, limits modulating wave M amplitude and is more than π, stays the most abundant Degree, nargin occurrence is depending on the turn-on and turn-off performance of used power switch pipe.What its modulation produced leads As shown in Figure 8, dotted line and solid line are respectively the Continuity signal of VD1 and VD4, VD2 and VD3 to messenger, Leaving certain interval between two signals, to prevent inverter upper and lower bridge arm from simultaneously turning on, modulating wave M value is the biggest, Gap is the biggest, and ON time is the least, and dutycycle is the least, such that it is able to realize pressure regulation.
Step 2: the magnitude of voltage in Real-time Collection 2N+1 bar branch road.
Step 3: calculate the average voltage of adjacent two branch roads in 2N+1 bar branch road.
Step 4: input modulating wave to 2N+1 end inverter, when modulating wave is more than the n-th branch road and (n+1)th The average voltage of branch road and during less than the average voltage of the (n+1)th branch road and the n-th+2 branch road, conducting 2N+1 The power switch pipe of end inverter the n-th branch road, wherein, n is integer, 1≤n≤2N-1.
For the modulation control of 2N+1 end inverter, the magnitude of voltage of Real-time Collection branch road B (1) to B (2N+1) E (1) arrive E (2N+1), calculate the average voltage between adjacent two branch roads, such as branch road B1 and branch road B2 it Between average voltage be E (1m), raw 2N the average voltage E (1m) of common property~E (2Nm) by that analogy, input tune Ripple sin processed, if modulating wave sin instantaneous value E (nm) < E (sin) < E (n+1m), then conducting respective branch B (n) On power switch pipe V (n), it is notable that E (2N+1) is more than the maximum of modulating wave sin, and E1 is little In the minima of modulating wave sin, preventing electric capacity from turning on electric discharge for a long time, voltage decline causes wave distortion, its In, N is high frequency auto transformer secondary side ports logarithm, and for integer and N > 1, i is integer and 1≤i≤N, N is integer and 1≤n≤2N-1.
In simple terms, high frequency square wave inversion control: low-voltage direct side input high-frequency inverter is semi-bridge inversion Circuit, controls upper and lower two power switch pipes and turns on and off at equal intervals, opens interval mutual deviation 180 degree, by This forms the high frequency square wave of high electronegative potential;High frequency square wave is formed after multiple electric pressure square-wave voltages through boosting, Carrying out rectification through full-bridge type rectification circuit, this circuit uses nature turn-off type diode, it is not necessary to control System;Rectification exports the DC voltage of multiple level.Multi-level inverse conversion: use nearest level to approach modulation: in real time Monitoring voltage with multiple levels magnitude of voltage, its value probably due to the discharge and recharge of electric capacity and produce the fluctuation of little scope; Adjacent two magnitudes of voltage are added and try to achieve meansigma methods divided by two, obtain altogether 2N average voltage and with voltage Average is marginal 2N+1 voltage range, and the level value on Mei Tiaozhi road is that the approximation of relevant voltage scope is equal Value, if modulating wave size is in this voltage range, then triggers the power switch pipe of corresponding level branch road, defeated Go out immediate voltage, approach the instantaneous voltage of modulating wave with this, thus can be with the various ripple of approximate fits The modulation of shape.If modulating wave waveform is sinusoidal wave, then each power switch pipe is in and sequential opens shutoff Process, the capacitor on corresponding branch road is also at charge and discharge process in turn, reduces the ripple of each branch road level Dynamic.
Embodiment described above only have expressed the several embodiments of the present invention, and it describes more concrete and detailed, But can not therefore be construed as limiting the scope of the patent.It should be pointed out that, for this area For those of ordinary skill, without departing from the inventive concept of the premise, it is also possible to make some deformation and change Entering, these broadly fall into protection scope of the present invention.Therefore, the protection domain of patent of the present invention should be with appended power Profit requires to be as the criterion.

Claims (10)

1. a grid-connected inverter circuit, it is characterised in that include inverter, N+1 port transformer, 2N Commutating phase device, 2N derided capacitors and 2N+1 end inverter, wherein, described N is more than or equal to 2 Positive integer;
The direct-flow input end of described inverter is connected with external dc power, the ac output end of described inverter It is connected with a winding of described N+1 port transformer, the Secondary Winding of described N+1 port transformer and institute The input stating 2N commutating phase device connects, and 2N commutating phase device output 2N+1 bar branch road, described 2N+1 bar props up Being parallel with single described derided capacitors in road between adjacent two branch roads, described 2N+1 bar branch road is connected respectively to 2N+1 end inverter input terminal, described 2N+1 end inverter output end is connected with external electrical network, described 2N Commutating phase device output 2N+1 bar branch road includes single ground connection branch road.
Grid-connected inverter circuit the most according to claim 1, it is characterised in that described inverter includes One switching tube, second switch pipe, the 3rd switching tube, the 4th switching tube, the first diode, the second diode, 3rd diode and the 4th diode;
Described first switching tube and described first diode inverse parallel, described second switch pipe and the described 2nd 2 Pole pipe inverse parallel, described 3rd switching tube and described 3rd diode inverse parallel, described 4th switching tube and institute Stating the 4th diode inverse parallel, described first switching tube is connected with described second switch pipe, described 3rd switch Pipe is connected with described 4th switching tube, and the drain electrode of described first switching tube and the drain electrode of described 3rd switching tube divide It is not connected with the positive pole of described external dc power, the source electrode of described second switch and described 4th switching tube Source electrode negative pole with described external dc power respectively is connected.
Grid-connected inverter circuit the most according to claim 1, it is characterised in that also include DC source, Described DC source is connected with the direct current input side of described inverter.
Grid-connected inverter circuit the most according to claim 1, it is characterised in that described N+1 port transformation Device includes high frequency auto N+1 port transformer.
Grid-connected inverter circuit the most according to claim 1, it is characterised in that described 2N commutating phase device Including 2N phase full-bridge rectifier.
Grid-connected inverter circuit the most according to claim 1, it is characterised in that described 2N commutating phase device Including nature turn-off type 2N phase full-bridge rectifier.
Grid-connected inverter circuit the most according to claim 1, it is characterised in that described 2N+1 end inversion Device includes 2N+1 end single-phase inverter.
Grid-connected inverter circuit the most according to claim 1, it is characterised in that described 2N+1 end inversion Device includes 2N+1 end three-phase inverter.
Grid-connected inverter circuit the most according to claim 8, it is characterised in that also include three-phase alternating current system System, described 2N+1 end three-phase inverter outfan is connected with described three-phase alternating current system.
10. a control method for the grid-connected inverter circuit as described in claim 1-9, its feature exists, including Step:
It is modulated controlling to the high frequency square wave of inverter output;
Magnitude of voltage in Real-time Collection 2N+1 bar branch road;
Calculate the average voltage of adjacent two branch roads in described 2N+1 bar branch road;
Input modulating wave is to 2N+1 end inverter, when described modulating wave is more than the n-th branch road and the (n+1)th branch road Average voltage and during less than the average voltage of the (n+1)th branch road and the n-th+2 branch road, turns on described 2N+1 The power switch pipe of end inverter the n-th branch road;
Wherein, described n is integer, 1≤n≤2N-1.
CN201610519063.7A 2016-07-01 2016-07-01 Grid-connected inverter circuit and its control method Active CN105978376B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201610519063.7A CN105978376B (en) 2016-07-01 2016-07-01 Grid-connected inverter circuit and its control method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201610519063.7A CN105978376B (en) 2016-07-01 2016-07-01 Grid-connected inverter circuit and its control method

Publications (2)

Publication Number Publication Date
CN105978376A true CN105978376A (en) 2016-09-28
CN105978376B CN105978376B (en) 2018-09-04

Family

ID=56954948

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201610519063.7A Active CN105978376B (en) 2016-07-01 2016-07-01 Grid-connected inverter circuit and its control method

Country Status (1)

Country Link
CN (1) CN105978376B (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107620828A (en) * 2017-09-20 2018-01-23 莱芜钢铁集团有限公司 Magnetic valve emergency service equipment and blast furnace process stove feeding system
CN110138005A (en) * 2019-05-13 2019-08-16 郑州大学 It is a kind of to cascade multi-modal photovoltaic combining inverter and its modulator approach
CN111682783A (en) * 2020-06-01 2020-09-18 新风光电子科技股份有限公司 High-voltage frequency conversion all-in-one machine adopting trapezoidal modulation waves and control method thereof
CN112688589A (en) * 2020-12-28 2021-04-20 青岛大学 Single-stage three-phase high-frequency link combined bidirectional AC/DC converter

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3815049B2 (en) * 1998-05-08 2006-08-30 株式会社デンソー Multi-level power converter
CN1645722A (en) * 2004-12-29 2005-07-27 泰豪科技股份有限公司 Multi-phase rectifier brushless generator with low voltage
RU2411627C1 (en) * 2010-01-11 2011-02-10 Открытое акционерное общество "Всероссийский научно-исследовательский проектно-конструкторский и технологический институт релестроения с опытным производством" Multilevel autonomous voltage inverter
CN102158094B (en) * 2011-05-17 2013-06-12 河北工业大学 Photovoltaic power generation DC-DC (Direct Current-Direct Current) converter and control method thereof
CN102255547A (en) * 2011-07-17 2011-11-23 西南交通大学 Voltage-sharing control circuit of diode-clamped multilevel converter DC (direct current) capacitor and voltage-sharing control method thereof
JP6025128B2 (en) * 2012-09-13 2016-11-16 国立研究開発法人産業技術総合研究所 Multilevel power conversion circuit and apparatus
CN102882410B (en) * 2012-10-29 2015-09-09 阳光电源股份有限公司 A kind of single-phase seven electrical level inverters
CN104333249B (en) * 2014-10-28 2016-08-31 北京合力电气传动控制技术有限责任公司 Seven level inverter circuits and control method, polyphase inverter and converter

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107620828A (en) * 2017-09-20 2018-01-23 莱芜钢铁集团有限公司 Magnetic valve emergency service equipment and blast furnace process stove feeding system
CN107620828B (en) * 2017-09-20 2024-03-19 莱芜钢铁集团有限公司 Electromagnetic valve emergency power supply equipment and blast furnace smelting furnace feeding system
CN110138005A (en) * 2019-05-13 2019-08-16 郑州大学 It is a kind of to cascade multi-modal photovoltaic combining inverter and its modulator approach
CN110138005B (en) * 2019-05-13 2023-02-03 郑州大学 Cascaded multi-mode photovoltaic grid-connected inverter and modulation method thereof
CN111682783A (en) * 2020-06-01 2020-09-18 新风光电子科技股份有限公司 High-voltage frequency conversion all-in-one machine adopting trapezoidal modulation waves and control method thereof
CN112688589A (en) * 2020-12-28 2021-04-20 青岛大学 Single-stage three-phase high-frequency link combined bidirectional AC/DC converter

Also Published As

Publication number Publication date
CN105978376B (en) 2018-09-04

Similar Documents

Publication Publication Date Title
CN101316074B (en) Back-to-back three-power level midpoint clamping current transformer of wind power generation system
CN101980409B (en) Grid-connected photovoltaic inverter
CN204103797U (en) The T-shaped inverter of a kind of accurate Z source three level
CN108988451A (en) Isolation type bidirectional charger control method and control circuit
CN107370392B (en) Electric power electric transformer towards mesohigh intelligent distribution network
CN107342698B (en) A kind of the three-phase and four-line zero voltage switch rectifier circuit and its modulator approach of band balance bridge arm
CN104079184A (en) Wind power converter based on bipolar direct-current structure
CN104638971B (en) A kind of photovoltaic combining inverter and its control method
CN109450268A (en) A kind of single-phase zero voltage switch back-to-back converter circuit and its modulator approach
CN107834854A (en) A kind of high-voltage large-capacity commutator transformer
CN105281361B (en) A kind of five-level double step-down combining inverter
CN105186912B (en) A kind of non-isolated full-bridge grid-connected inverter of two-stage type
CN102223099A (en) Adaptive three-phase balanced control cascaded three-phase bridge converter
CN102361408A (en) Non-isolated photovoltaic grid-connected inverter and switching control time sequence thereof
CN105119516A (en) Quasi Z-source inverter with high boost gain
CN105978376A (en) Grid-connected inverter circuit and control method thereof
CN103887981A (en) Full-bridge DC-DC converter
CN105591559A (en) Multi-port converter based on high-frequency inversion
CN112928919A (en) Isolated high-frequency resonant DC-DC converter with wide output voltage range and method
CN110350816B (en) Single-stage single-phase current type inverter with energy storage inductor connected with active buffer circuit in parallel
CN107565814A (en) A kind of quasi- Z source switch boosting inverters of high-gain suitable for fuel cell power generation
CN104796019B (en) A kind of Z sources three-level PWM rectifier and its control method
CN106452153A (en) Variable-topology Trans-Z-source inverter
CN210490732U (en) Energy storage converter
CN101272088A (en) Back-to-back striding capacitance convertor of wind power generation system

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant