CN106411171A - Transformer-free type low-leakage-current photovoltaic grid-connected inverter circuit with active clamp and modulation method thereof - Google Patents
Transformer-free type low-leakage-current photovoltaic grid-connected inverter circuit with active clamp and modulation method thereof Download PDFInfo
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- CN106411171A CN106411171A CN201610897891.4A CN201610897891A CN106411171A CN 106411171 A CN106411171 A CN 106411171A CN 201610897891 A CN201610897891 A CN 201610897891A CN 106411171 A CN106411171 A CN 106411171A
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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
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- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
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Abstract
The invention discloses a transformer-free type low-leakage-current photovoltaic grid-connected inverter circuit with an active clamp and a modulation method thereof. The transformer-free type low-leakage-current photovoltaic grid-connected inverter circuit with the active clamp comprises two filter capacitors Cdc1, Cdc2, eight switch tubes S1, S2, S3, S4, S5, S6, S7, S8 and two filter inductors L1, L2, and is characterized in that an active switch tube is additionally arranged in the circuit so as to form a clamping unit, common-mode voltage in a grid-connected inductance follow current stage is clamped to the midpoint of a bus capacitor by being matched with an appropriate switching sequence, common-mode voltage disturbance of the system is removed, and thus a suspension problem of common-mode voltage of a decoupling inverter in zero level output is solved; and parasitic oscillation of a common-mode circuit is removed at the same time, and a phenomenon of common-mode resonance is suppressed. The photovoltaic grid-connected inverter circuit disclosed by the invention has the advantages of simple circuit structure, high efficiency, simple modulation method and the like. The photovoltaic grid-connected inverter circuit can ensure an inverter not to be affected by a current zero crossing point in unit power factor running, and can avoid current waveform distortion caused by influences of grid power fluctuations or operations at a non unit power factor.
Description
Technical field
The invention belongs to Power Electronic Technique parallel network power generation technology field is and in particular to a kind of no change of active clamp
Depressor type low-leakage current photovoltaic grid-connected inversion circuit and its modulator approach.
Background technology
In recent years, with the continuous reduction of grid-connected photovoltaic system cost, distributed photovoltaic generates electricity by way of merging two or more grid systems and has obtained extensively
General application and rapid development.However, photovoltaic parallel in system early investment is high, the cost recovery cycle is long, therefore how to enter one
Step reduction system cost of electricity-generating, the generating efficiency of raising system and system reliability become the focus of concern.
As electric energy conversion important interface, photovoltaic combining inverter scheme select direct relation system efficiency,
Reliability and cost.In the low profile photovoltaic grid-connected system of 1～5k W, in order to pursue efficient energy conversion efficiency and fall
Low system cost, system is generally using the single-phase photovoltaic grid-connected inverter without Industrial Frequency Transformer isolation.However, no becoming single-phase
In depressor type photovoltaic grid-connected inverting system, between photovoltaic array and the earth, there is larger parasitic capacitance over the ground.If posted over the ground
There are high frequency voltage ripples on raw electric capacity, then can produce larger Ground leakage current.This Ground leakage current not only can cause seriously
Electromagnetic interference problem, can reduce grid-connected current quality simultaneously, and bring to the personal safety of photovoltaic cell attendant hidden
Suffer from.
In order to suppress the high frequency common mode leakage current in Transformer-free photovoltaic parallel in system, traditional Transformer-free inversion
Circuit generally cuts off the electrical connection of AC and DC side in grid-connected inductance freewheeling period, reduces the high frequency arteries and veins of common-mode voltage
Dynamic.But, the common-mode voltage due to system is in suspended state in grid-connected inductance freewheeling period, and the circuit by common mode loop is posted
Raw parameter and the impact of line voltage Zero-crossing Distortion, inevitably cause high frequency common mode leakage current, that is, suppression leakage current
Not thorough, do not tackle the problem at its root, still can cause above-mentioned hidden danger.
Content of the invention
Herein from drain current suppressing principle it is proposed that a kind of single-phase photovoltaic grid-connected inversion of new Transformer-free is electric
Road, this circuit passes through additional active switch pipe in circuit, constitutes clamping unit, coordinates appropriate switching sequence, will be grid-connected
The common-mode voltage of inductance freewheeling period is clamped to the midpoint of bus capacitor, eliminates system common-mode voltage disturbance, and then solves to understand
The suspension problem when zero level exports for the coupling type powder inverter common-mode voltage；Eliminate the unwanted oscillation in common mode loop, suppression simultaneously
Common mode resonance phenomenon.Labor several operation modes of circuit in literary composition, give a kind of PWM being applied to this circuit and adjust
Method processed.
The technical scheme that circuit of the present invention adopts is：A kind of Transformer-free low-leakage current of active clamp is grid-connected inverse
Become circuit, including：Two filter capacitors Cdc1, Cdc2, eight switching tubes S1, S2, S3, S4, S5, S6, S7, S8 and two filtering
Inductance L1, L2；
Described first filter capacitor Cdcl and the second filter capacitor Cdc2 series connection, then with power sources in parallel,
The positive pole of DC source is connected with the colelctor electrode of the first filter capacitor Cdcl positive pole and the 5th switching tube S5,
The negative pole of DC source is connected with the emitter stage of the second filter capacitor Cdc2 negative pole and the 6th switching tube S6,
First switch pipe S1, second switch pipe S2, the 3rd switching tube S3, the 4th switching tube S4 constitute conventional H type inversion
Bridge connected mode,
The colelctor electrode colelctor electrode with first switch pipe S1 respectively of the emitter stage of the 5th switching tube S5 and the 6th switching tube S6
It is connected with the emitter stage of second switch pipe S2,
The collector and emitter of the 7th switching tube S7 colelctor electrode and the second switch pipe S2 with first switch pipe S1 respectively
Emitter stage be connected, that is, in parallel with H inverter bridge,
The emitter stage of the 8th switching tube S8 is connected with the midpoint of two series filtering electric capacity, colelctor electrode and the 5th switching tube S5
Emitter stage and the 7th switching tube S7 colelctor electrode be connected,
One end of first filter inductance L1 is connected with the emitter stage of first switch pipe S1, the live wire L phase of the other end and electrical network
Even,
One end of second filter inductance L2 is connected with the colelctor electrode of the 4th switching tube S4, the center line N phase of the other end and electrical network
Even.
On the basis of technique scheme, described switching tube is insulated gate bipolar translator power tube IGBT, or is metal-oxygen
Change layer-quasiconductor-field-effect transistor MOSFET.
The technical scheme of the modulator approach of the present invention is：
In the positive half period of line voltage, first switch pipe S1, the 4th switching tube S4, the 5th switching tube S5, the 6th switch
Pipe S6 is triggered by high-frequency modulation signal and controls, and simultaneously turns on and turns off, the 7th switching tube S7 is then by the high frequency modulated being complementary to
Signal triggering controls, and the 8th switching tube S8 is identical with the 7th switching tube S7 switching signal, and rest switch pipe turns off；Inverter is in
During the power output stage, first switch pipe S1, the 4th switching tube S4, the 5th switching tube S5 and the 6th switching tube S6 conducting, the 7th
Switching tube S7 turn off, now according to formula common-mode voltage Ucm=(UAN+UBN)/2=(Udc+0)/2 (in formula, Ucm common mode
Voltage, the voltage between UAN A point and N point, the voltage between UBN B point and N point) constant；Inverter is in zero electricity
During pressure freewheeling period, first switch pipe S1, the 4th switching tube S4, the 5th switching tube S5 and the 6th switching tube S6 turn off, and the 7th opens
Close pipe S7, the 8th switching tube S8 conducting, now common-mode voltage is clamped the mid-point voltage in two filter capacitors for the stable pincers of switch
Place, that is, keep Ucm=Udc/2 constant；
In the negative half-cycle of line voltage, second switch pipe S2, the 3rd switching tube S3, the 5th switching tube S5, the 6th switch
Pipe S6 is triggered by high-frequency modulation signal and controls, and simultaneously turns on and turns off, the 7th switching tube S7 is then by the high frequency modulated being complementary to
Signal triggering controls, and the 8th switching tube S8 is identical with the 7th switching tube S7 switching signal, and rest switch pipe turns off；Inverter is in
During the power output stage, second switch pipe S2, the 3rd switching tube S3, the 5th switching tube S5, the 6th switching tube S6 conducting, the 7th opens
Close pipe S7 to turn off, now constant according to formula common-mode voltage Ucm=(UAN+UBN)/2=(0+Udc)/2；Inverter is in zero electricity
During pressure freewheeling period, second switch pipe S2, the 3rd switching tube S3, the 5th switching tube S5 and the 6th switching tube S6 turn off, and the 7th opens
Close pipe S7, the 8th switching tube S8 conducting, now common-mode voltage is clamped the mid-point voltage in two filter capacitors for the stable pincers of switch
Place, that is, keep Ucm=Udc/2 constant.
Beneficial effects of the present invention are：
Compared with traditional Transformer-free photovoltaic grid-connected inversion circuit, this circuit has more preferable Ground leakage current suppression energy
Power.The commonly used direct current of single-phase transformerless inverter circuit of main flow or exchange decoupling technology, block common mode current at present
Circulation path.However, exporting the stage in zero level, the brachium pontis mid-point voltage of foregoing circuit all in the nondeterministic statement suspending,
Common-mode voltage can not remain constant, is mainly affected by both sides.First, there is of short duration electrical network during the commutation of line voltage zero passage
In the lateral mains side energy back stage, now, the voltage on two filter inductances is undergone mutation, and the mutation of inductive drop causes altogether
Mode voltage is undergone mutation.2nd, there is parallel parasitic capacitance in device for power switching, leads to decoupling switch can not thoroughly cut off common mode and leads to
Road, this parasitic capacitance forms equivalent tank loop with common code impedance, under the Persistent Excitation of on off state switching, it is possible to producing
The very important high frequency Ground leakage current of life.For this problem, introduce active clamp switch so that common-mode voltage is by bus electricity
Hold neutral-point-clamped, it is constant that common-mode voltage is maintained at Udc/2, has been inherently eliminated Ground leakage current.The present invention has circuit knot
The advantages of structure is simple, efficiency high, modulator approach are simple.Ensure that inverter is not subject to electric current mistake when unity power factor runs
The impact of zero point distortion, it can be avoided that because of grid power influence of fluctuations or the current wave that works in non-unity power factor and lead to
Shape distorts.Improve inverter safety coefficient, realize the improvement to the output quality of power supply.It is applied to tighter to leakage current restriction
The Transformer-free photovoltaic grid-connected inverting system of lattice.
Brief description
The Transformer-free low-leakage current photovoltaic grid-connected inversion electrical block diagram of Fig. 1 active clamp；
Fig. 2 inverter circuit switch modulating method schematic diagram；
Mode one schematic diagram in power transmission stage when Fig. 3 inverter circuit is in line voltage positive half cycle；
Mode two schematic diagram of freewheeling period when Fig. 4 inverter circuit is in line voltage positive half cycle；
Mode three schematic diagram in energy back stage when Fig. 5 inverter circuit is in line voltage positive half cycle；
Mode four schematic diagram in power transmission stage when Fig. 6 inverter circuit is in line voltage negative half period；
Mode five schematic diagram of freewheeling period when Fig. 7 inverter circuit is in line voltage negative half period；
Mode six schematic diagram in energy back stage when Fig. 8 inverter circuit is in line voltage negative half period；
Fig. 9 inverter circuit flows into the simulation waveform of power network current and grid-connected photovoltaic system leakage current.
Specific embodiment
Below in conjunction with the accompanying drawing in the embodiment of the present invention, the technical scheme in the embodiment of the present invention is carried out clear, complete
Site preparation describes.
As shown in figure 1, the Transformer-free low-leakage current photovoltaic grid-connected inversion circuit knot of the active clamp of present invention offer
Structure schematic diagram, including：Two filter capacitors Cdc1, Cdc2, eight switching tubes S1, S2, S3, S4, S5, S6, S7, S8 and two filters
Ripple inductance L1, L2.
Described first filter capacitor Cdc1 and the second filter capacitor Cdc2 series connection, then with power sources in parallel,
The positive pole of DC source is connected with the colelctor electrode of the first filter capacitor Cdc1 positive pole and the 5th switching tube S5,
The negative pole of DC source is connected with the emitter stage of the second filter capacitor Cdc2 negative pole and the 6th switching tube S6,
First switch pipe S1, second switch pipe S2, the 3rd switching tube S3, the 4th switching tube S4 constitute conventional H type inversion
Bridge connected mode,
The colelctor electrode colelctor electrode with first switch pipe S1 respectively of the emitter stage of the 5th switching tube S5 and the 6th switching tube S6
It is connected with the emitter stage of second switch pipe S2,
The collector and emitter of the 7th switching tube S7 colelctor electrode and the second switch pipe S2 with first switch pipe S1 respectively
Emitter stage be connected, that is, in parallel with H inverter bridge,
The emitter stage of the 8th switching tube S8 is connected with the midpoint of two series filtering electric capacity, colelctor electrode and the 5th switching tube S5
Emitter stage and the 7th switching tube S7 colelctor electrode be connected,
One end of first filter inductance L1 is connected with the emitter stage of first switch pipe S1, the live wire L phase of the other end and electrical network
Even,
One end of second filter inductance L2 is connected with the colelctor electrode of the 4th switching tube S4, the center line N phase of the other end and electrical network
Even.
The HF switch frequency of inverter circuit of the present invention can consider the factors such as power system capacity, switching tube parameter and radiating
Rational choice, the HF switch frequency that the present embodiment is selected is 16kHz, and its modulator approach is as shown in Figure 2.
Sets forth six kinds of working conditions of inverter circuit of the present invention in Fig. 3-Fig. 8.
Fig. 3 and Fig. 4 is respectively the Transformer-free low-leakage current photovoltaic grid-connected inversion circuit of active clamp in line voltage
The operation principle schematic diagram of positive half period, first switch pipe S1, the 4th switching tube S4, the 5th switching tube S5, the 6th switching tube S6
Triggered by high-frequency modulation signal and control, simultaneously turn on and turn off, the 7th switching tube S7 and the 8th switching tube S8 is then by being complementary to
High-frequency modulation signal triggering control.
Power transmission stage during the positive half cycle of line voltage, as shown in figure 3, this stage：First switch pipe S1, the 4th switch
Pipe S4, the 5th switching tube S5, the 6th switching tube S6 simultaneously turn on, and the 7th switching tube S7 and the 8th switching tube S8 turns off, electric current stream
Through DC side positive pole, the 5th switching tube S5, first switch pipe S1, the first filter inductance L1, AC electrical network, the second filter inductance
L2, the 4th switching tube S4, the 6th switching tube S6, DC side negative pole, DC side outputs current to AC, the common mode of described circuit
Voltage is Udc/2.
Freewheeling period during the positive half cycle of line voltage, as shown in figure 4, this stage：First switch pipe S1, the 4th switching tube
S4, the 5th switching tube S5, the 6th switching tube S6 simultaneously turn off, the 7th switching tube S7 and the 8th switching tube S8 conducting, and electric current flows through
7th switching tube S7, the anti-paralleled diode of second switch pipe S2, the first filter inductance L1, AC electrical network, the second filtered electrical
Sense L2, the anti-paralleled diode of the 3rd switching tube S3, common-mode voltage clamper can be filtered by the clamping switch tube S8 of conducting at two
At the mid-point voltage Udc/2 of electric capacity.
Line voltage, by just half circumferential negative half period conversion, when line voltage is not yet zero, drives commutation, that is, existing cannot
The Zero-crossing Distortion avoiding, now energy fed back by the lateral mains side of electrical network, as shown in figure 5, electric current flows through DC side negative pole, the 6th
The fly-wheel diode of switching tube S6, the fly-wheel diode of second switch pipe S2, the first filter inductance L1, AC electrical network, second
Filter inductance L2, the fly-wheel diode of the 3rd switching tube S3, the fly-wheel diode of the 5th switching tube S5, DC side positive pole.This energy
Amount freewheeling period, the first filter inductance L1 and the second filter inductance L2 can each bear very big negative voltage suddenly, be worth for (-
Udc-ug)/2, and, because current electric grid current value reduces, two filter inductances are just inducing contrary with the sense of current
Electromotive force, this two voltage directions are identical, and therefore, inductive current rises in forward voltage effect lower linear, incorgruous change
The induction electromotive force that the former direction of inductance should reduce, leads to A point and N point current potential to rise.When mode three switches to mode two, it is subject to
The impact of mode three, common-mode voltage increase it is impossible to constant for Udc/2, increased clamper and open the light after pipe S8, common-mode voltage can be clamped
Position is at the mid-point voltage Udc/2 of two filter capacitors.
Fig. 6 and Fig. 7 is respectively the Transformer-free low-leakage current photovoltaic grid-connected inversion circuit of active clamp in line voltage
The operation principle schematic diagram of negative half-cycle, second switch pipe S2, the 3rd switching tube S3, the 5th switching tube S5, the 6th switching tube S6
Triggered by high-frequency modulation signal and control, simultaneously turn on and turn off, the 7th switching tube S7 and the 8th switching tube S8 is then by being complementary to
High-frequency modulation signal triggering control.
Power transmission stage during line voltage negative half period, as shown in fig. 6, this stage：Second switch pipe S2, the 3rd switch
Pipe S3, the 5th switching tube S5, the 6th switching tube S6 simultaneously turn on, and the 7th switching tube S7 and the 8th switching tube S8 turns off, electric current stream
Through DC side positive pole, the 5th switching tube S5, the 3rd switching tube S3, the second filter inductance L2, AC electrical network, the first filter inductance
L1, second switch pipe S2, the 6th switching tube S6, DC side negative pole, DC side outputs current to AC, the common mode of described circuit
Voltage is Udc/2.
Freewheeling period during line voltage negative half period, as shown in fig. 7, this stage：Second switch pipe S2, the 3rd switching tube
S3, the 5th switching tube S5, the 6th switching tube S6 simultaneously turn off, the 7th switching tube S7 and the 8th switching tube S8 conducting, and electric current flows through
7th switching tube S7, the anti-paralleled diode of the 4th switching tube S4, the second filter inductance L2, AC electrical network, the first filtered electrical
Sense L1, the anti-paralleled diode of first switch pipe S1, common-mode voltage clamper can be filtered by the clamping switch tube S8 of conducting at two
At the mid-point voltage Udc/2 of electric capacity.
Line voltage is changed from negative half period to positive half cycle, when line voltage is not yet zero, drives commutation, that is, existing cannot
The Zero-crossing Distortion avoiding, now energy fed back by the lateral mains side of electrical network, as shown in figure 8, electric current flows through DC side negative pole, the 6th
The fly-wheel diode of switching tube S6, the fly-wheel diode of the 4th switching tube S4, the second filter inductance L2, AC electrical network, first
Filter inductance L1, the fly-wheel diode of first switch pipe S1, the fly-wheel diode of the 5th switching tube S5, DC side positive pole.This energy
Amount freewheeling period, the first filter inductance L1 and the second filter inductance L2 can each bear very big positive voltage suddenly, be worth and be
(Udc-ug)/2, and, because current electric grid current value increases, two filter inductances are just inducing identical with the sense of current
Electromotive force, this two voltage directions are contrary, and therefore, inductive current declines in negative voltage effect lower linear, incorgruous change
The induction electromotive force that the former direction of inductance should increase, leads to B point and N point current potential to decline.When mode six switches to mode five, it is subject to
The impact of mode six, common-mode voltage reduce it is impossible to constant for Udc/2, increased clamper and open the light after pipe S8, common-mode voltage can be clamped
Position is at the mid-point voltage Udc/2 of two filter capacitors.
According to above-mentioned specific embodiments, simulate inverter circuit of the present invention and flow into the current waveform of electrical network and photovoltaic simultaneously
The leakage current waveform of net electricity generation system, as seen from Figure 7, grid current is regular sine wave, the value of leakage current constant in horizontal seat
Mark 0 value, in safety standard, leakage current must not exceed 300mA, therefore, meets safety standard.
Last it should be noted that above example is only in order to illustrate technical scheme and unrestricted, with reference to relatively
Good embodiment has been described in detail to the present invention, it will be understood by those within the art that, can be to the skill of the present invention
Art scheme is modified and equivalent, and without deviating from the spirit and scope of technical solution of the present invention, it all should be covered at this
Bright right.
Claims (3)
1. a kind of Transformer-free low-leakage current photovoltaic grid-connected inversion circuit of active clamp is it is characterised in that include：Two filters
Ripple electric capacity Cdc1, Cdc2, eight switching tubes S1, S2, S3, S4, S5, S6, S7, S8 and two filter inductances L1, L2；
Described first filter capacitor Cdc1 and the second filter capacitor Cdc2 series connection, then with power sources in parallel,
The positive pole of DC source is connected with the colelctor electrode of the first filter capacitor Cdc1 positive pole and the 5th switching tube S5,
The negative pole of DC source is connected with the emitter stage of the second filter capacitor Cdc2 negative pole and the 6th switching tube S6,
First switch pipe S1, second switch pipe S2, the 3rd switching tube S3, the 4th switching tube S4 constitute conventional H type inversion bridging
Connect mode,
The colelctor electrode of the emitter stage of the 5th switching tube S5 and the 6th switching tube S6 colelctor electrode and with first switch pipe S1 respectively
The emitter stage of two switching tube S2 is connected,
The collector and emitter of the 7th switching tube S7 respectively with the sending out of the colelctor electrode of first switch pipe S1 and second switch pipe S2
Emitter-base bandgap grading is connected, that is, in parallel with H inverter bridge,
The emitter stage of the 8th switching tube S8 is connected with the midpoint of two series filtering electric capacity, and colelctor electrode and the 5th switching tube S5 send out
The colelctor electrode of emitter-base bandgap grading and the 7th switching tube S7 is connected,
One end of first filter inductance L1 is connected with the emitter stage of first switch pipe S1, and the other end is connected with the live wire L of electrical network,
One end of second filter inductance L2 is connected with the colelctor electrode of the 4th switching tube S4, and the other end is connected with the center line N of electrical network.
2. the Transformer-free low-leakage current photovoltaic grid-connected inversion circuit of active clamp according to claim 1, its feature
It is：Described switching tube is insulated gate bipolar translator power tube IGBT, or is metal oxide layer-quasiconductor-field-effect transistor
MOSFET.
3. the modulation methods of the Transformer-free low-leakage current photovoltaic grid-connected inversion circuit of active clamp according to claim 1
Method it is characterised in that：
In the positive half period of line voltage, first switch pipe S1, the 4th switching tube S4, the 5th switching tube S5, the 6th switching tube S6
Triggered by high-frequency modulation signal and control, simultaneously turn on and turn off, the 7th switching tube S7 is then by the high-frequency modulation signal being complementary to
Triggering controls, and the 8th switching tube S8 is identical with the 7th switching tube S7 switching signal, and rest switch pipe turns off；Inverter is in power
During the output stage, first switch pipe S1, the 4th switching tube S4, the 5th switching tube S5 and the 6th switching tube S6 conducting, the 7th switch
Pipe S7 turns off, now constant according to formula common-mode voltage Ucm=(Udc+0)/2；When inverter is in no-voltage freewheeling period, the
One switching tube S1, the 4th switching tube S4, the 5th switching tube S5 and the 6th switching tube S6 turn off, the 7th switching tube S7, the 8th switch
Pipe S8 turns on, and now common-mode voltage is clamped the stable pincers of switch at the mid-point voltage of two filter capacitors, that is, keep Ucm=
Udc/2 is constant；
In the negative half-cycle of line voltage, second switch pipe S2, the 3rd switching tube S3, the 5th switching tube S5, the 6th switching tube S6
Triggered by high-frequency modulation signal and control, simultaneously turn on and turn off, the 7th switching tube S7 is then by the high-frequency modulation signal being complementary to
Triggering controls, and the 8th switching tube S8 is identical with the 7th switching tube S7 switching signal, and rest switch pipe turns off；Inverter is in power
During the output stage, second switch pipe S2, the 3rd switching tube S3, the 5th switching tube S5, the 6th switching tube S6 conducting, the 7th switching tube
S7 turns off, now constant according to formula common-mode voltage Ucm=(0+Udc)/2, when inverter is in no-voltage freewheeling period, second
Switching tube S2, the 3rd switching tube S3, the 5th switching tube S5 and the 6th switching tube S6 turn off, the 7th switching tube S7, the 8th switching tube
S8 turns on, and now common-mode voltage is clamped the stable pincers of switch at the mid-point voltage of two filter capacitors, that is, keep Ucm=Udc/
2 is constant.
Priority Applications (1)
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Cited By (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107134937A (en) * | 2017-06-07 | 2017-09-05 | 上海正泰电源系统有限公司 | A kind of three level multiple-pulses output transformerless inverter circuit |
| CN107546999A (en) * | 2017-08-22 | 2018-01-05 | 浙江大学 | A kind of band active power decouples single-phase ZVT inverter circuit and its modulator approach |
| CN107689740A (en) * | 2017-09-01 | 2018-02-13 | 燕山大学 | A kind of modulator approach of single-phase current code converter |
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| CN111865132A (en) * | 2020-08-26 | 2020-10-30 | 阳光电源（上海）有限公司 | Single-phase inverter, inverter topology circuit and control method thereof |
| CN112838778A (en) * | 2021-01-06 | 2021-05-25 | 宜宾职业技术学院 | Non-isolated current type grid-connected inverter without overlapping time and control method and system thereof |
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101814856A (en) * | 2009-11-24 | 2010-08-25 | 南京航空航天大学 | Non-isolated grid-connected inverter and switch control time sequence thereof |
| JP2011004464A (en) * | 2009-06-16 | 2011-01-06 | Toshiba Corp | Power conversion equipment |
| CN103956927A (en) * | 2014-04-28 | 2014-07-30 | 浙江大学 | Voltage-active-clamping non-transformer-type single-phase photovoltaic inverter |
| CN203813688U (en) * | 2014-05-08 | 2014-09-03 | 国家电网公司 | Inverter topological structure used for suppressing leakage current in photovoltaic grid-connected system |
| CN105656077A (en) * | 2016-01-22 | 2016-06-08 | 江苏大学 | Efficient low-leakage current seven-switch photovoltaic grid-connected inverter circuit and modulation method thereof |
-
2016
- 2016-10-14 CN CN201610897891.4A patent/CN106411171A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2011004464A (en) * | 2009-06-16 | 2011-01-06 | Toshiba Corp | Power conversion equipment |
| CN101814856A (en) * | 2009-11-24 | 2010-08-25 | 南京航空航天大学 | Non-isolated grid-connected inverter and switch control time sequence thereof |
| CN103956927A (en) * | 2014-04-28 | 2014-07-30 | 浙江大学 | Voltage-active-clamping non-transformer-type single-phase photovoltaic inverter |
| CN203813688U (en) * | 2014-05-08 | 2014-09-03 | 国家电网公司 | Inverter topological structure used for suppressing leakage current in photovoltaic grid-connected system |
| CN105656077A (en) * | 2016-01-22 | 2016-06-08 | 江苏大学 | Efficient low-leakage current seven-switch photovoltaic grid-connected inverter circuit and modulation method thereof |
Non-Patent Citations (2)
| Title |
|---|
| HUAFENG XIAO等: "An Optimized Transformerless Photovoltaic Grid-Connected Inverter", 《IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS》 * |
| 张犁等: "中点钳位非隔离全桥光伏并网逆变器", 《中国电机工程学报》 * |
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| CN111865132B (en) * | 2020-08-26 | 2024-02-09 | 阳光电源（上海）有限公司 | Single-phase inverter, inverter topology circuit and control method thereof |
| CN112838778A (en) * | 2021-01-06 | 2021-05-25 | 宜宾职业技术学院 | Non-isolated current type grid-connected inverter without overlapping time and control method and system thereof |
| CN116169677A (en) * | 2023-02-17 | 2023-05-26 | 三峡大学 | Parallel active filter based on grouping U-shaped unit inverter and control method |
| CN116488494A (en) * | 2023-04-14 | 2023-07-25 | 深圳市海孜寻网络科技有限公司 | Automatic buck-boost conversion circuit and control method |
| CN117277242A (en) * | 2023-11-21 | 2023-12-22 | 锦浪科技股份有限公司 | Leakage current suppression method for photovoltaic system |
| CN117277242B (en) * | 2023-11-21 | 2024-02-20 | 锦浪科技股份有限公司 | Leakage current suppression method for photovoltaic system |
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