CN105610343A - Modulation method for inhibiting leakage current of H-bridge cascade inverters - Google Patents

Modulation method for inhibiting leakage current of H-bridge cascade inverters Download PDF

Info

Publication number
CN105610343A
CN105610343A CN201610127854.5A CN201610127854A CN105610343A CN 105610343 A CN105610343 A CN 105610343A CN 201610127854 A CN201610127854 A CN 201610127854A CN 105610343 A CN105610343 A CN 105610343A
Authority
CN
China
Prior art keywords
module
vref
level
frequency module
2vdc
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
CN201610127854.5A
Other languages
Chinese (zh)
Other versions
CN105610343B (en
Inventor
王付胜
于世能
杨乐
毛旺
张兴
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.)
Hefei University of Technology
Original Assignee
Hefei University of Technology
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 Hefei University of Technology filed Critical Hefei University of Technology
Priority to CN201610127854.5A priority Critical patent/CN105610343B/en
Publication of CN105610343A publication Critical patent/CN105610343A/en
Application granted granted Critical
Publication of CN105610343B publication Critical patent/CN105610343B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • 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
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
    • 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
    • H02M1/44—Circuits or arrangements for compensating for electromagnetic interference in converters or inverters
    • 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
    • H02M1/0048—Circuits or arrangements for reducing losses
    • H02M1/0054—Transistor switching losses
    • 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
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
    • Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

The invention discloses a modulation method for inhibiting leakage current of H-bridge cascade inverters. The modulation method can maintain the sum of parasitic capacitance voltages of all modules to be constant, and thus the leakage current is eliminated. The method comprises the following steps: dividing all modules into module groups in pairs according to rules, and dividing into a power frequency module group and a high frequency module group; obtaining the on-off state of the power frequency module group through comparison of modulating waves and fixed values; obtaining the on-off state of the high frequency module group through comparison of corrected modulating waves and two stacked triangle carriers; and generating corresponding PWM signals through the combination of the on-off states, and distributing to corresponding pins. The scheme can be used for multiple H-bridge cascade inverters, and extra hardware cost does not need to be added, so that the leakage current flowing into a power grid can be eliminated, meanwhile the switching loss is relatively low, and the implementation manner is simple.

Description

Suppress the modulator approach of H bridge cascaded inverter leakage current
Technical field
The present invention relates to a kind of modulator approach of single-phase H bridge cascaded inverter, especially can suppress the modulator approach of non-isolation type H bridge cascade grid-connected photovoltaic inverter leakage current; It is applicable to parallel network power generation field.
Background technology
For ensureing to use safety, VDE4105 standard has strict restriction to photovoltaic (Photovoltaic, PV) grid-connected system common mode current (leakage current). Adopt net side power frequency isolating transformer can realize the electrical isolation of PV and electrical network, suppress leakage current, still, Industrial Frequency Transformer volume is large, Heavy Weight, cost is high, system effectiveness is low. If adopt high frequency transformer to realize the electrical isolation of PV and electrical network, can reduce system bulk, weight and cost, but power conversion is divided into several grades, and system effectiveness do not have clear improvement. And the conversion efficiency of combining inverter and the generating efficiency of photovoltaic generating system are closely related. Therefore the non-isolated grid-connected inverter that, efficiency is high, volume is little, lightweight and cost is low has a clear superiority in. But save transformer and make there has been electrical connection between photovoltaic battery panel and electrical network, may make leakage current significantly increase, and bring conduction and radiation interference, increase grid-connected current harmonic wave and loss, even jeopardize equipment and personal security. Become one of study hotspot therefore suppress the leakage current of non-isolated grid-connected inverter.
At present existing non-isolation type single-phase photovoltaic grid-connected inverter is successfully applied to commercial sources, as the SunnyMiniCentral series photovoltaic inverter of SMA company. But these structures are all the modified topologys based on single H bridge, are mainly applicable to small-power occasion. And photovoltaic DC-to-AC converter of future generation need to reach higher power grade and efficiency, therefore multi-electrical level inverter becomes main study subject. Cascade H bridge multi-electrical level inverter has the advantages that modularization is easily expanded, cost is low and output voltage quality is high, and its DC side can be independently-powered by photovoltaic battery panel, its independent MPPT maximum power point tracking (MPPT) is controlled becomes possibility, thereby Cascade H bridge construction becomes the photovoltaic DC-to-AC converter structure of tool prospect. Meanwhile, the leakage current of Cascade H bridge grid-connected photovoltaic inverter also becomes a major issue in its application.
Have some achievements about the drain current suppressing of Cascade H bridge grid-connected photovoltaic inverter at present, as be entitled as " Analysisandsuppressionofleakagecurrentincascaded-multile vel-inverterbasedPVsystems; " Y.ZhouandH.Li, " IEEETrans.PowerElectron. ", 2014,29 (10), 5265 – 5277 (" cascade connection multi-level photovoltaic inverter leakage current analysis and inhibition ", " IEEE journal-power electronics periodical ", 5277 pages of the 29th the 10th phases 5265 of volume – in 2014) article; This article proposes two kinds of leakage current hardware and suppresses scheme, be to adopt respectively different passive filters at DC side and AC, but this scheme has the following disadvantages:
1) passive filter is mainly made up of inductance and electric capacity, is applied in volume, weight and the cost that in circuit, can greatly increase inverter, reduces the energy conversion efficiency of inverter simultaneously;
2) leakage current harmonic wave scope is wider, and is subject to such environmental effects, makes filter parameter design process comparatively complicated;
3) Cascade H bridge inverter actual operating frequency is lower, and the main harmonic frequency of its leakage current is also lower, causes the drain current suppressing effect of wave filter unsatisfactory.
Be entitled as " HybridMulticarrierModulationtoReduceLeakageCurrentinaTra nsformerlessCascadedMultilevelInverterforPhotovoltaicSys tems ", RajasekarSelvamuthukumaran, AbhishekGarg, andRajeshGupta, " IEEETransactionsonPowerElectron ", 2015, 30 (4), 1779-1783 (" reducing the hybrid modulation strategy of non-isolation type photovoltaic inverter leakage current ", " IEEE journal-power electronics periodical ", the 30th volume the 4th phase 1779-1783 page in 2015) article, this article has proposed a kind of modulation strategy of the two H bridge cascaded inverters of realizing based on two carrier waves, and the deficiency of the method is as follows:
1) this modulator approach can not suppress to flow into the leakage current of electrical network, cannot improve grid-connected current quality;
2) the method has been used the stacked carrier wave of two homophases, but needs 180 ° of phase shifts every half power frequency period carrier wave, and this has increased undoubtedly hardware and has realized difficulty.
3) this modulator approach is only applicable to two module-cascade inverters, does not have versatility.
As can be seen here, prior art can not, not increasing extra cost and not affecting under grid-connected current quality, solve the leakage problem of bridge Cascade H bridge inverter preferably.
Summary of the invention
The technical problem to be solved in the present invention is for overcoming problems of the prior art, a kind of extra hardware that do not need is proposed, can eliminate and flow into the leakage current of electrical network, and suppress single module leakage current, and the modulator approach of the simple inhibition H bridge cascaded inverter leakage current of implementation.
In order to complete object of the present invention, the present invention proposes a kind of modulator approach of the H of inhibition bridge cascaded inverter leakage current, comprise level synthesis mode; The key step of this modulator approach is as follows:
Step 1, establishes H bridge cascaded inverter and is made up of n H bridge module, and each H bridge module DC voltage is identical, and is designated as Vdc, by the on off state of each H bridge module by switch function SaiAnd SbiRepresent,
Wherein,
N=2k, k is greater than 1 integer;
SaiFor the switch function of module i bridge arm a, SbiFor the switch function of module i bridge arm b, and meet:
Step 2, according to the H bridge cascaded inverter described in step 1, by module i and module (n-i+1) composition module i, definition module 1 is power frequency module to module (k-1), module n/2 is high frequency module; The on off state of module i is by one group of switch function (S simultaneouslyai，Sbi，Sa(n-i+1)，Sb(n-i+1)) represent;
Step 3, according to the module group technology of step 2, only export-2Vdc of power frequency module, 0 and tri-kinds of level of 2Vdc; High frequency module output-2Vdc ,-Vdc, 0, Vdc and five kinds of level of 2Vdc;
Step 4, according to the each module working method described in step 3, for making inverter output (2n+1) plant level, the switch combination mode of power frequency module is as follows:
For power frequency module i, if-when 2*i≤(n*Vref)≤2*i, power frequency module i exports zero level; If (n*Vref)>when 2*i, power frequency module i exports 2Vdc; If (n*Vref)<and when-2*i, power frequency module i output-2Vdc;
If-2≤(n*Vref)≤2 o'clock simultaneously, Vr=n*Vref; If 2*i < (n*Vref)≤(2*i+2) (i=1,2 ... k-1) time, Vr=(n*Vref-2i); (if 2*i-2)≤(n*Vref) < (2*i) (i=1,2 ... k-1) time, Vr=(n*Vref+2i+2);
Wherein, Vref is original modulating wave, and meets-1≤Vref≤1; Vr is revised modulating wave;
Step 5, according to the each module working method described in step 3, for making inverter output (2n+1) plant level, the switch combination mode of high frequency module is as follows:
If 0≤Vr<Vc1 and Vref>=0 o'clock, high frequency module output zero level;
If Vc1≤Vr<Vc2 and Vref>=0 o'clock, high frequency module output Vdc;
If Vr >=Vc2 and Vref >=0 o'clock, high frequency module output 2Vdc;
If Vr>=Vc2 and Vref<0 o'clock, high frequency module output zero level;
If Vc1≤Vr < Vc2 and Vref < 0 o'clock, high frequency module output-Vdc;
If Vr < Vc1 and Vref < 0 o'clock, high frequency module output-2Vdc;
Wherein, Vc1, Vc2 are two stacked carrier wave triangular carriers, and 2 >=Vc2 >=1 >=Vc1 >=0;
Preferably, the working method of the module of power frequency described in step 3 is:
Produce 2Vdc level by off state 1010, produce-2Vdc of on off state 0101 level, produces 0 level at modulating wave positive half period by off state 1100, and produces 0 level at modulating wave negative half-cycle by off state 0011.
Preferably, the working method of the module of high frequency described in step 3 is:
Produce 2Vdc level by off state 1010, on off state 1000 or 1110 produces Vdc level, and on off state 1100 or 0011 produces 0 level, on off state 0001 or 0111 generation-Vdc level, produce-2Vdc of on off state 0101 level.
Preferably, the switch combination mode of the module of high frequency described in step 5 is to require selector switch state to export required level according to switch motion least number of times.
Preferably, stacked triangular carrier described in step 5 is two synchronous stacked triangular carriers.
Preferably, stacked triangular carrier described in step 5 is the stacked triangular carrier of two antiphases.
With respect to prior art, beneficial effect of the present invention is as follows:
1, do not need extra hardware, can not increase volume, weight and the cost of inverter, can not reduce the energy conversion efficiency of inverter simultaneously.
2, can eliminate the leakage current that flows into electrical network, improve power network current quality; Can suppress single module leakage current, reduce system loss and electromagnetic interference simultaneously.
3, power frequency module operating frequency is lower, has reduced the switching loss of inverter.
4, be applicable to any even number H bridge cascaded inverter.
Brief description of the drawings
Fig. 1 is single-phase H bridge cascade photovoltaic combining inverter schematic diagram.
Fig. 2 is module packet mode schematic diagram.
Fig. 3 is power frequency module fundamental diagram.
Fig. 4 is the fundamental diagram that high frequency module adopts homophase carrier wave.
Fig. 5 is the fundamental diagram that high frequency module adopts anti-phase carrier wave.
Detailed description of the invention
In order to make object of the present invention, technical scheme and advantage clearer, below in conjunction with drawings and Examples, the present invention is described in more detail.
The modulator approach of inhibition H bridge cascaded inverter leakage current disclosed by the invention is applied to single-phase non-isolation H bridge cascade photovoltaic parallel in system, and systematic schematic diagram as shown in Figure 1. In Fig. 1, each module is H bridge construction, contains two output p brachium pontis, and its bridge arm a is connected to upper level module or and inductance L1Connect, brachium pontis b is connected to next stage module or and inductance L2Connect. The AC series connection output of all modules, through two filter inductance L1And L2Be connected to electrical network Eg. Each module DC side is powered by photovoltaic battery panel, and DC voltage is Vdc. CpviIt is the photovoltaic panel parasitic capacitance of module i.
The on off state of each module is by switch function SaiAnd SbiRepresent, wherein,
SaiFor the switch function of module i bridge arm a, SbiFor the switch function of module i bridge arm b, and meet:
For single-phase H bridge cascade photovoltaic combining inverter shown in Fig. 1, the basic step of the modulator approach of inhibition H bridge cascaded inverter leakage current disclosed by the invention is as follows:
Referring to Fig. 1, Fig. 2, Fig. 3, Fig. 4 and Fig. 5.
Step 1, establishes H bridge cascaded inverter and is made up of n H bridge module, and each H bridge module DC voltage is identical, and is designated as Vdc, by the on off state of each H bridge module by switch function SaiAnd SbiRepresent,
Wherein,
N=2k, k is greater than 1 integer;
SaiFor the switch function of module i bridge arm a, SbiFor the switch function of module i bridge arm b, and meet:
Step 2, according to the H bridge cascaded inverter described in step 1, by module i and module (n-i+1) composition module i, definition module 1 is power frequency module to module (k-1), module n/2 is high frequency module; The on off state of module i is by one group of switch function (S simultaneouslyai，Sbi，Sa(n-i+1)，Sb(n-i+1)) represent;
Step 3, according to the module group technology of step 2, only export-2Vdc of power frequency module, 0 and tri-kinds of level of 2Vdc; High frequency module output-2Vdc ,-Vdc, 0, Vdc and five kinds of level of 2Vdc;
The working method of described power frequency module is: produce 2Vdc level by off state 1010, produce-2Vdc of on off state 0101 level, produce 0 level at modulating wave positive half period by off state 1100, and produce 0 level at modulating wave negative half-cycle by off state 0011.
The working method of described high frequency module is: produce 2Vdc level by off state 1010, on off state 1000 or 1110 produces Vdc level, on off state 1100 or 0011 produces 0 level, on off state 0001 or 0111 generation-Vdc level, produce-2Vdc of on off state 0101 level.
Step 4, according to the each module working method described in step 3, for making inverter output (2n+1) plant level, the switch combination mode of power frequency module is as follows:
For power frequency module i, if-when 2*i≤(n*Vref)≤2*i, power frequency module i exports zero level; If (n*Vref)>when 2*i, power frequency module i exports 2Vdc; If (n*Vref)<and when-2*i, power frequency module i output-2Vdc;
If-2≤(n*Vref)≤2 o'clock simultaneously, Vr=n*Vref; If 2*i < (n*Vref)≤(2*i+2) (i=1,2 ... k-1) time, Vr=(n*Vref-2i); (if 2*i-2)≤(n*Vref) < (2*i) (i=1,2 ... k-1) time, Vr=(n*Vref+2i+2);
Wherein, Vref is original modulating wave, and meets-1≤Vref≤1; Vr is revised modulating wave;
Step 5, according to the each module working method described in step 3, for making inverter output (2n+1) plant level, the switch combination mode of high frequency module is as follows:
If 0≤Vr<Vc1 and Vref>=0 o'clock, high frequency module output zero level;
If Vc1≤Vr<Vc2 and Vref>=0 o'clock, high frequency module output Vdc;
If Vr >=Vc2 and Vref >=0 o'clock, high frequency module output 2Vdc;
If Vr>=Vc2 and Vref<0 o'clock, high frequency module output zero level;
If Vc1≤Vr < Vc2 and Vref < 0 o'clock, high frequency module output-Vdc;
If Vr < Vc1 and Vref < 0 o'clock, high frequency module output-2Vdc;
Wherein, Vc1, Vc2 are two stacked carrier wave triangular carriers, and 2 >=Vc2 >=1 >=Vc1 >=0.
The switch combination mode of described high frequency module is to require selector switch state to export required level according to switch motion least number of times.
Described stacked triangular carrier is two synchronous stacked triangular carriers or is the stacked triangular carrier of two antiphases.
Below in conjunction with specific embodiment, the present invention is described in more detail.
Embodiment 1
Step 1, the Cascade H bridge inverter being formed by 4 (k=2) individual H bridge module, each module DC voltage is identical, and is designated as Vdc, by the on off state of each module by switch function SaiAnd SbiRepresent,
Wherein, SaiFor the switch function of module i bridge arm a, SbiFor the switch function of module i bridge arm b, and meet:
Step 2, according to 4 module-cascade inverters described in step 1, by module i and module (5-i) composition module i, definition module 1 is power frequency module, module 2 is high frequency module; The on off state of module i is by one group of switch function (S simultaneouslyaiSbiSa(5-i)Sb(5-i)) represent;
Step 3, according to the module group technology of step 2, only export-2Vdc of power frequency module, 0 and tri-kinds of level of 2Vdc, specific works mode is for to produce 2Vdc level by off state 1010, produce-2Vdc of on off state 0101 level, produce 0 level at modulating wave positive half period by off state 1100, and produce 0 level at modulating wave negative half-cycle by off state 0011; High frequency module output-2Vdc ,-Vdc, 0, Vdc and five kinds of level of 2Vdc, specific works mode is for to produce 2Vdc level by off state 1010, on off state 1000 or 1110 produces Vdc level, on off state 1100 or 0011 produces 0 level, on off state 0001 or 0111 generation-Vdc level, produce-2Vdc of on off state 0101 level;
Step 4, according to the each module working method described in step 3, for making 9 kinds of level of inverter output, the switch combination mode of power frequency module is as follows:
For power frequency module i, if-when 2*i≤(4*Vref)≤2*i, power frequency module i exports zero level; If (4*Vref)>when 2*i, power frequency module i exports 2Vdc; If (4*Vref)<and when-2*i, power frequency module i output-2Vdc;
If-2≤(4*Vref)≤2 o'clock simultaneously, Vr=4*Vref; If 2*i < (4*Vref)≤(2*i+2) (i=1,2 ... k-1) time, Vr=(4*Vref-2i); (if 2*i-2)≤(4*Vref) < (2*i) (i=1,2 ... k-1) time, Vr=(4*Vref+2i+2);
Wherein, Vref is original modulating wave, and meets-1≤Vref≤1; Vr is revised modulating wave;
Step 5, according to the each module working method described in step 3, for making inverter export 9 level, the switch combination mode of high frequency module is as follows:
If 0≤Vr<Vc1 and Vref>=0 o'clock, high frequency module output zero level;
If Vc1≤Vr<Vc2 and Vref>=0 o'clock, high frequency module output Vdc;
If Vr >=Vc2 and Vref >=0 o'clock, high frequency module output 2Vdc;
If Vr>=Vc2 and Vref<0 o'clock, high frequency module output zero level;
If Vc1≤Vr < Vc2 and Vref < 0 o'clock, high frequency module output-Vdc;
If Vr < Vc1 and Vref < 0 o'clock, high frequency module output-2Vdc;
Simultaneously require selector switch state to export required level according to switch motion least number of times;
Wherein, Vc1, Vc2 are two stacked carrier wave triangular carriers of same-phase, and 2 >=Vc2 >=1 >=Vc1 >=0;
The present embodiment realize schematic diagram as shown in Fig. 1～4.
Embodiment 2
In the present embodiment, power frequency module working method is identical with embodiment 1, and high frequency module adopts the stacked triangular carrier comparison of modulating wave and two antiphases, and manner of comparison is identical with embodiment. The fundamental diagram of the present embodiment high frequency module as shown in Figure 5.
Finally, produce the corresponding signal that drives according to the switch function of the each module obtaining, be dispensed to corresponding switching tube according to the distribution principle of inverter.
Those skilled in the art will readily understand; the foregoing is only preferred embodiment of the present invention; not in order to limit the present invention, all any amendments of doing within the spirit and principles in the present invention, be equal to and replace and improvement etc., within all should being included in protection scope of the present invention.

Claims (6)

1. a modulator approach that suppresses H bridge cascaded inverter leakage current, comprises level synthesis mode, it is characterized in that, the key step of this modulator approach is as follows:
Step 1, establishes H bridge cascaded inverter and is made up of n H bridge module, and each H bridge module DC voltage is identical, and is designated as Vdc, by the on off state of each H bridge module by switch function SaiAnd SbiRepresent;
Wherein,
N=2k, k is greater than 1 integer;
SaiFor the switch function of module i bridge arm a, SbiFor the switch function of module i bridge arm b, and meet:
Step 2, according to the H bridge cascaded inverter described in step 1, by module i and module (n-i+1) composition module i, definition module 1 is power frequency module to module (k-1), module n/2 is high frequency module; The on off state of module i is by one group of switch function (S simultaneouslyai，Sbi，Sa(n-i+1)，Sb(n-i+1)) represent;
Step 3, according to the module group technology of step 2, only export-2Vdc of power frequency module, 0 and tri-kinds of level of 2Vdc; High frequency module output-2Vdc ,-Vdc, 0, Vdc and five kinds of level of 2Vdc;
Step 4, according to the each module working method described in step 3, for making inverter output (2n+1) plant level, the switch combination mode of power frequency module is as follows:
For power frequency module i, if-when 2*i≤(n*Vref)≤2*i, power frequency module i exports zero level; If (n*Vref)>when 2*i, power frequency module i exports 2Vdc; If (n*Vref)<and when-2*i, power frequency module i output-2Vdc;
If-2≤(n*Vref)≤2 o'clock simultaneously, Vr=n*Vref; If 2*i < (n*Vref)≤(2*i+2) (i=1,2 ... k-1) time, Vr=(n*Vref-2i); (if 2*i-2)≤(n*Vref) < (2*i) (i=1,2 ... k-1) time, Vr=(n*Vref+2i+2);
Wherein, Vref is original modulating wave, and meets-1≤Vref≤1; Vr is revised modulating wave;
Step 5, according to the each module working method described in step 3, for making inverter output (2n+1) plant level, the switch combination mode of high frequency module is as follows:
If 0≤Vr<Vc1 and Vref>=0 o'clock, high frequency module output zero level;
If Vc1≤Vr<Vc2 and Vref>=0 o'clock, high frequency module output Vdc;
If Vr >=Vc2 and Vref >=0 o'clock, high frequency module output 2Vdc;
If Vr>=Vc2 and Vref<0 o'clock, high frequency module output zero level;
If Vc1≤Vr < Vc2 and Vref < 0 o'clock, high frequency module output-Vdc;
If Vr < Vc1 and Vref < 0 o'clock, high frequency module output-2Vdc;
Wherein, Vc1, Vc2 are two stacked carrier wave triangular carriers, and 2 >=Vc2 >=1 >=Vc1 >=0.
2. according to a kind of modulator approach that suppresses H bridge cascaded inverter leakage current described in right 1, it is characterized in that, the working method of the module of power frequency described in step 3 is:
Produce 2Vdc level by off state 1010, produce-2Vdc of on off state 0101 level, produces 0 level at modulating wave positive half period by off state 1100, and produces 0 level at modulating wave negative half-cycle by off state 0011.
3. according to a kind of modulator approach that suppresses H bridge cascaded inverter leakage current described in right 1, it is characterized in that, the working method of the module of high frequency described in step 3 is:
Produce 2Vdc level by off state 1010, on off state 1000 or 1110 produces Vdc level, and on off state 1100 or 0011 produces 0 level, on off state 0001 or 0111 generation-Vdc level, produce-2Vdc of on off state 0101 level.
4. according to a kind of modulator approach that suppresses H bridge cascaded inverter leakage current described in right 1, it is characterized in that, the switch combination mode of the module of high frequency described in step 5 is to require selector switch state to export required level according to switch motion least number of times.
5. according to a kind of modulator approach that suppresses H bridge cascaded inverter leakage current described in right 1, it is characterized in that, stacked triangular carrier described in step 5 is two synchronous stacked triangular carriers.
6. according to a kind of modulator approach that suppresses H bridge cascaded inverter leakage current described in right 1, it is characterized in that, stacked triangular carrier described in step 5 is the stacked triangular carrier of two antiphases.
CN201610127854.5A 2016-03-07 2016-03-07 Suppress the modulator approach of H bridge cascaded inverter leakage currents Active CN105610343B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201610127854.5A CN105610343B (en) 2016-03-07 2016-03-07 Suppress the modulator approach of H bridge cascaded inverter leakage currents

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201610127854.5A CN105610343B (en) 2016-03-07 2016-03-07 Suppress the modulator approach of H bridge cascaded inverter leakage currents

Publications (2)

Publication Number Publication Date
CN105610343A true CN105610343A (en) 2016-05-25
CN105610343B CN105610343B (en) 2018-04-03

Family

ID=55989942

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201610127854.5A Active CN105610343B (en) 2016-03-07 2016-03-07 Suppress the modulator approach of H bridge cascaded inverter leakage currents

Country Status (1)

Country Link
CN (1) CN105610343B (en)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106208782A (en) * 2016-07-20 2016-12-07 合肥工业大学 Cascaded H-bridges photovoltaic inverter leakage current suppressing method based on Model Predictive Control
CN106301051A (en) * 2016-08-30 2017-01-04 阳光电源股份有限公司 The drain current suppressing method of single-phase non-isolated cascaded H-bridges inverter and restraining device
CN106712110A (en) * 2017-01-18 2017-05-24 燕山大学 Current source grid connection converter and control method
CN107508316A (en) * 2017-08-24 2017-12-22 山东大学 Dual-layer optimization global synchronization variable duration impulse system and method
CN112165269A (en) * 2020-09-18 2021-01-01 浙江大学 Control method of single-phase cascaded full-bridge multi-level converter and multi-level converter
CN114268233A (en) * 2021-11-23 2022-04-01 安徽理工大学 Novel power equalization modulation strategy for cascaded H-bridge
CN115622376A (en) * 2022-11-16 2023-01-17 西安奇点能源股份有限公司 Cascade type energy storage converter system with function of inhibiting leakage current and control method

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101188364A (en) * 2007-12-12 2008-05-28 中国科学院电工研究所 A voltage balance circuit for serial connected super capacitor
JP2013251885A (en) * 2012-05-02 2013-12-12 Manabu Yabuki Power-saving transistor for controlling power of direct-current voltage
US20140312966A1 (en) * 2013-04-19 2014-10-23 Schaffner Emv Ag Active emc filter
CN105140966A (en) * 2015-10-12 2015-12-09 国网天津市电力公司 Modulation strategy for suppressing non-isolated photovoltaic system leakage current
CN105337519A (en) * 2015-11-18 2016-02-17 阳光电源股份有限公司 Self-checking system and self-checking method for cascaded multilevel converter

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101188364A (en) * 2007-12-12 2008-05-28 中国科学院电工研究所 A voltage balance circuit for serial connected super capacitor
JP2013251885A (en) * 2012-05-02 2013-12-12 Manabu Yabuki Power-saving transistor for controlling power of direct-current voltage
US20140312966A1 (en) * 2013-04-19 2014-10-23 Schaffner Emv Ag Active emc filter
CN105140966A (en) * 2015-10-12 2015-12-09 国网天津市电力公司 Modulation strategy for suppressing non-isolated photovoltaic system leakage current
CN105337519A (en) * 2015-11-18 2016-02-17 阳光电源股份有限公司 Self-checking system and self-checking method for cascaded multilevel converter

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106208782A (en) * 2016-07-20 2016-12-07 合肥工业大学 Cascaded H-bridges photovoltaic inverter leakage current suppressing method based on Model Predictive Control
CN106301051A (en) * 2016-08-30 2017-01-04 阳光电源股份有限公司 The drain current suppressing method of single-phase non-isolated cascaded H-bridges inverter and restraining device
CN106301051B (en) * 2016-08-30 2019-03-05 阳光电源股份有限公司 The drain current suppressing method and inhibition device of single-phase non-isolated Cascade H bridge inverter
CN106712110A (en) * 2017-01-18 2017-05-24 燕山大学 Current source grid connection converter and control method
CN107508316A (en) * 2017-08-24 2017-12-22 山东大学 Dual-layer optimization global synchronization variable duration impulse system and method
CN107508316B (en) * 2017-08-24 2019-04-16 山东大学 Dual-layer optimization global synchronization variable duration impulse system and method
CN112165269A (en) * 2020-09-18 2021-01-01 浙江大学 Control method of single-phase cascaded full-bridge multi-level converter and multi-level converter
CN114268233A (en) * 2021-11-23 2022-04-01 安徽理工大学 Novel power equalization modulation strategy for cascaded H-bridge
CN115622376A (en) * 2022-11-16 2023-01-17 西安奇点能源股份有限公司 Cascade type energy storage converter system with function of inhibiting leakage current and control method

Also Published As

Publication number Publication date
CN105610343B (en) 2018-04-03

Similar Documents

Publication Publication Date Title
Raju et al. Modular multilevel converters technology: a comprehensive study on its topologies, modelling, control and applications
CN105450059B (en) Inhibit the modulator approach of two H bridge cascaded inverter leakage currents
CN105610343A (en) Modulation method for inhibiting leakage current of H-bridge cascade inverters
Song et al. Cascaded multilevel inverter employing three-phase transformers and single DC input
Abarzadeh et al. A modified static ground power unit based on novel modular active neutral point clamped converter
Xu et al. A low-harmonic control method of bidirectional three-phase Z-source converters for vehicle-to-grid applications
Salem et al. Novel three-phase multilevel inverter with reduced components for low-and high-voltage applications
Khanfara et al. A multicarrier PWM technique for five level inverter connected to the grid
Moradi et al. Improvement of the modulation method for single-phase transformerless photovoltaic conergy inverter for reactive power injection capability
Allehyani et al. A new modular micro-inverter with sinusoidal output voltage using gan switches for pv modules
Razi et al. Microinverter topology based single-stage grid-connected photovoltaic system: A review
Colak et al. Conventional H-bridge and recent multilevel inverter topologies
Scott et al. Bidirectional, three-port, three-phase multilevel inverter based on switched-capacitor cells
Tanguturi et al. Optimization based approach to improve power extraction in a single phase grid connected photovoltaic system
Patel et al. An interleaved switched capacitor single-phase inverter with a modified control strategy for a standalone PV system with battery storage
Yousofi-Darmian et al. A new four-level transformer-less single-phase inverter for grid-connected photovoltaic systems
Rao et al. Cascaded diode clamped inverter based grid‐connected photovoltaic energy conversion system with enhanced power handling capability and efficiency
Kabalcı Introduction to multilevel voltage source inverters
Vanam et al. A Novel Multi Carrier PWM Based Harmonic Mitigation of Multi Level PV Inverter with Grid Integration
Nunna et al. A single-phase simplified DC-AC converter using DC-link capacitors and an H-bridge
Ebrahimi et al. Voltage balancing of diode-clamped multilevel converter by using modified quasi-Z-source network
Hameed et al. Cascaded H–Bridge Multilevel Inverter: Review of Topologies and Pulse Width Modulation
Singaravelu et al. Design and implementation of seven level cascaded H-Bridge inverter using low frequency transformer with single DC source
Vitorino et al. Multilevel asymmetric single-phase current source rectifiers
Habib et al. A Novel Asymmetric Nine Level Inverter with Reduced Device Count Suitable for Renewable Energy Applications

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