CN108023497B - Series simultaneous power supply forward cycle conversion type single-stage multi-input high-frequency link inverter - Google Patents
Series simultaneous power supply forward cycle conversion type single-stage multi-input high-frequency link inverter Download PDFInfo
- Publication number
- CN108023497B CN108023497B CN201810020153.0A CN201810020153A CN108023497B CN 108023497 B CN108023497 B CN 108023497B CN 201810020153 A CN201810020153 A CN 201810020153A CN 108023497 B CN108023497 B CN 108023497B
- Authority
- CN
- China
- Prior art keywords
- power
- input
- output
- frequency
- circuit
- 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.)
- Active
Links
- 238000006243 chemical reaction Methods 0.000 title claims abstract description 75
- 238000002955 isolation Methods 0.000 claims abstract description 39
- 230000009466 transformation Effects 0.000 claims abstract description 11
- 230000002457 bidirectional effect Effects 0.000 claims description 70
- 238000010586 diagram Methods 0.000 claims description 25
- 230000010363 phase shift Effects 0.000 claims description 25
- 238000004146 energy storage Methods 0.000 claims description 22
- 238000011217 control strategy Methods 0.000 claims description 15
- 239000003990 capacitor Substances 0.000 claims description 10
- 238000009826 distribution Methods 0.000 claims description 10
- 238000010248 power generation Methods 0.000 claims description 10
- 238000007599 discharging Methods 0.000 claims description 8
- 230000006641 stabilisation Effects 0.000 claims description 6
- 238000011105 stabilization Methods 0.000 claims description 6
- 239000000969 carrier Substances 0.000 claims description 4
- 230000000630 rising effect Effects 0.000 claims description 4
- 238000004364 calculation method Methods 0.000 claims description 3
- 238000000034 method Methods 0.000 claims description 2
- 239000013589 supplement Substances 0.000 claims description 2
- 238000004804 winding Methods 0.000 claims 15
- 230000003321 amplification Effects 0.000 claims 6
- 238000003199 nucleic acid amplification method Methods 0.000 claims 6
- 238000001914 filtration Methods 0.000 claims 2
- 230000001939 inductive effect Effects 0.000 claims 2
- 230000000903 blocking effect Effects 0.000 claims 1
- 230000001360 synchronised effect Effects 0.000 claims 1
- 238000005516 engineering process Methods 0.000 abstract description 2
- 238000003860 storage Methods 0.000 description 5
- 239000000446 fuel Substances 0.000 description 4
- 230000008859 change Effects 0.000 description 3
- 125000004122 cyclic group Chemical group 0.000 description 3
- 230000001105 regulatory effect Effects 0.000 description 3
- 230000033228 biological regulation Effects 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 2
- 230000000295 complement effect Effects 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000003912 environmental pollution Methods 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- 239000004065 semiconductor Substances 0.000 description 2
- 101100134058 Caenorhabditis elegans nth-1 gene Proteins 0.000 description 1
- 239000003034 coal gas Substances 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000008030 elimination Effects 0.000 description 1
- 238000003379 elimination reaction Methods 0.000 description 1
- 230000005669 field effect Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 239000003345 natural gas Substances 0.000 description 1
- 239000003209 petroleum derivative Substances 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 239000004576 sand Substances 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 238000010792 warming Methods 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Images
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
- H02M7/538—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 push-pull configuration
- H02M7/53803—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 push-pull configuration with automatic control of output voltage or current
-
- H02J3/382—
-
- H02J3/387—
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
- H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
- H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
- H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M7/53—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
- H02M7/537—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters
- H02M7/5387—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters in a bridge configuration
- H02M7/53871—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters in a bridge configuration with automatic control of output voltage or current
-
- 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
- H02M1/0067—Converter structures employing plural converter units, other than for parallel operation of the units on a single load
- H02M1/007—Plural converter units in cascade
-
- 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
- H02M1/0083—Converters characterised by their input or output configuration
Abstract
The invention relates to a series simultaneous power supply forward cycle conversion type single-stage multi-input high-frequency link inverter, which is structurally characterized in that a multi-input single-output high-frequency inverter circuit with a series simultaneous selection power switch connects a plurality of input filters which are not in common with a shared output high-frequency isolation transformation cycle conversion filter circuit, each input end of the multi-input single-output high-frequency inverter circuit is correspondingly connected with the output end of each input filter one by one, and the output end of the multi-input single-output high-frequency inverter circuit is connected with the input end of the output high-frequency isolation transformation cycle conversion filter circuit; the medium and small-capacity distributed power supply system has the characteristics of multiple input sources which are not in common ground, power supply at the same time or in a time-sharing manner, high-frequency isolation between output and input, common output high-frequency voltage transformation and cycle conversion filter circuits, simple circuit, single-stage power conversion, high conversion efficiency, small output voltage ripple, wide application prospect and the like, and lays a key technology for realizing the medium and small-capacity distributed power supply system for the combined power supply of various new energy sources.
Description
Technical Field
The invention relates to a series simultaneous power supply forward cycle conversion type single-stage multi-input high-frequency link inverter, belonging to the power electronic conversion technology.
Background
The inverter is a static converter which applies a power semiconductor device to convert unstable and poor direct current electric energy into stable and good alternating current electric energy, and is used for alternating current loads or realizes alternating current grid connection. The inverter with low-frequency electrical isolation (including no electrical isolation) or high-frequency electrical isolation between the output alternating current load or the alternating current power grid and the input direct current power supply is respectively called as a low-frequency link inverter and a high-frequency link inverter. The electrical isolation element plays a major role in the inverter: (1) the electrical isolation between the output and the input of the inverter is realized, and the safety reliability and the electromagnetic compatibility of the operation of the inverter are improved; (2) the matching between the output voltage and the input voltage of the inverter is realized, namely the technical effect that the output voltage of the inverter is higher than, equal to or lower than the input voltage is realized, and the application range of the inverter is greatly widened; (3) when the working frequency of the high-frequency transformer or the high-frequency energy storage type transformer is above 20kHz, the volume and the weight of the transformer are greatly reduced, and audio noise is eliminated. Therefore, the inverter has an important application value in secondary power conversion using a dc generator, a battery, a photovoltaic cell, a fuel cell, or the like as a main dc power source.
The new energy sources (also called green energy sources) such as solar energy, wind energy, tidal energy, geothermal energy and the like have the advantages of cleanness, no pollution, low price, reliability, richness and the like, thereby having wide application prospect. Due to the increasing shortage of traditional fossil energy (non-renewable energy) such as petroleum, coal and natural gas, serious environmental pollution, global warming, nuclear waste generated by nuclear energy production, environmental pollution and the like, the development and utilization of new energy are receiving more and more attention. The new energy power generation mainly comprises photovoltaic, wind power, fuel cells, water power, geothermal energy and the like, and all the types have the defects of unstable and discontinuous power supply, change along with climatic conditions and the like, so that a distributed power supply system adopting various new energy sources for combined power supply is needed.
A traditional new energy distributed power supply system is shown in figures 1 and 2. The system generally adopts a plurality of single-input direct-current converters to convert electric energy of new energy power generation equipment which does not need energy storage, such as photovoltaic cells, fuel cells, wind driven generators and the like, through one unidirectional direct-current converter respectively, and the output ends of the new energy power generation equipment are connected to a direct-current bus of a common inverter in parallel or in series, so that the combined power supply of various new energy sources is ensured, and the coordinated work can be realized. The distributed power generation system realizes the priority utilization of the power supplied by a plurality of input sources to the load and the energy, improves the stability and the flexibility of the system, but has the defects of two-stage power conversion, low power density, low conversion efficiency, high cost and the like, and the practicability of the distributed power generation system is limited by a great degree.
In order to simplify the circuit structure and reduce the number of power conversion stages, a novel single-stage new energy distributed power supply system needs to be formed by replacing the conventional multi-input inverter with a direct-current converter and an inverter two-stage cascade circuit structure shown in fig. 1 and 2 by the novel multi-input inverter with a single-stage circuit structure shown in fig. 3. The single-stage multi-input inverter allows for multiple new energy inputs, and the nature, magnitude and characteristics of the input sources may be the same or may vary widely. The novel single-stage new energy distributed power supply system has the advantages of simple circuit structure, single-stage power conversion, low cost and the like, and a plurality of input sources simultaneously or in time-sharing mode supply power to a load in one high-frequency switching period.
Therefore, the active search for a single-stage multi-input inverter allowing multiple new energy sources to supply power jointly and a new energy source distributed power supply system thereof is urgent, and the active search has a very important significance for improving the stability and flexibility of the system and realizing the prior utilization or the full utilization of the new energy sources.
Disclosure of Invention
The invention aims to provide a series simultaneous power supply forward cyclic wave conversion type single-stage multiple-input high-frequency link inverter which has the characteristics of multiple new energy sources for combined power supply, non-common ground of input direct current power sources, a multiple-input single-output high-frequency inverter circuit provided with a series simultaneous selection switch, high-frequency isolation between output and input, simultaneous or time-sharing power supply of multiple input power sources to a load, simple circuit topology, a common output high-frequency isolation variable-voltage cyclic wave conversion filter circuit, single-stage power conversion, high conversion efficiency, small output voltage ripple, small output capacity, wide application prospect and the like.
The technical scheme of the invention is as follows: a series connection simultaneous power supply forward cycle conversion type single-stage multiple-input high-frequency link inverter is formed by connecting a plurality of input filters which are not in common with a common output high-frequency isolation transformation cycle conversion filter circuit through a multiple-input single-output high-frequency inverter circuit, wherein each input end of the multiple-input single-output high-frequency inverter circuit is correspondingly connected with the output end of each input filter one by one, the output end of the multiple-input single-output high-frequency inverter circuit is connected with the input end of a high-frequency transformer of the output high-frequency isolation transformation cycle conversion filter circuit, the multiple-input single-output high-frequency inverter circuit is formed by sequentially cascading a plurality of paths of series connection simultaneous selection power switch circuits and bidirectional power flow single-input single-output high-frequency inverter circuits which are sequentially connected in series with the output ends in series, and is equivalent to a bidirectional power flow single-input single-output high-frequency inverter, each series simultaneous selection power switch circuit is composed of a two-quadrant power switch and a power diode, the source electrode of the two-quadrant power switch is connected with the cathode of the power diode, the drain electrode of the two-quadrant power switch and the anode of the power diode are respectively the positive and negative polarity input ends of the series simultaneous selection power switch circuit, the source electrode of the two-quadrant power switch and the anode of the power diode are respectively the positive and negative polarity output ends of the series simultaneous selection power switch circuit, the output high-frequency isolation transformation cycle conversion filter circuit is composed of a high-frequency transformer, a cycle converter and an output filter which are sequentially cascaded, and the cycle converter is composed of a plurality of four-quadrant high-frequency power switches capable of bearing bidirectional voltage stress and bidirectional current stress.
The invention relates to a multi-input inverter circuit structure formed by cascading a direct current converter and an inverter of a traditional multi-new-energy combined power supply system in two stages, which is constructed into a novel single-stage multi-input inverter circuit structure connected with a simultaneous selection switch in series, and provides a series simultaneous power supply forward cycle conversion type single-stage multi-input high-frequency link inverter circuit structure, a topology family and an energy management control strategy thereof.
The series simultaneous power supply forward cycle conversion type single-stage multi-input high-frequency link inverter can invert a plurality of non-common-ground unstable input direct-current voltages into stable and high-quality output alternating-current power required by a load, and has the characteristics of non-common-ground multi-input direct-current power supplies, no isolation among multi-input single-output high-frequency inverter circuits, high-frequency isolation between output and input, simultaneous or time-sharing power supply of the multi-input power supplies to the load, simple circuit topology, common output high-frequency isolation variable-voltage cycle conversion filter circuits, single-stage power conversion, high conversion efficiency, small output voltage ripples, small output medium and small capacity, wide application prospect and the like. The comprehensive performance of the series simultaneous power supply forward cycle conversion type single-stage multi-input high-frequency link inverter is superior to that of a multi-input inverter formed by two-stage cascading of a traditional direct-current converter and an inverter.
Drawings
Fig. 1 shows a conventional two-stage new energy distributed power supply system with a plurality of unidirectional dc converters connected in parallel at output terminals.
Fig. 2 shows a conventional two-stage new energy distributed power supply system with a plurality of unidirectional dc converters connected in series at output terminals.
Fig. 3 is a schematic block diagram of a novel single-stage multiple-input inverter.
Fig. 4 is a schematic block diagram of a series simultaneous power supply forward cycle conversion type single-stage multi-input high-frequency link inverter.
Fig. 5 is a circuit diagram of a series simultaneous supply forward cycle conversion type single-stage multi-input high-frequency link inverter.
FIG. 6 is a schematic waveform diagram of a bipolar phase-shifting control series simultaneous power supply forward cycle conversion type single-stage multi-input high-frequency link inverter steady state.
FIG. 7 is a steady-state schematic waveform diagram of a unipolar phase-shift controlled series simultaneous-power-supply forward cycle conversion type single-stage multi-input high-frequency link inverter.
Fig. 8 is a schematic diagram of a circuit topology example of a series simultaneous power supply forward cycle conversion type single-stage multi-input high-frequency link inverter, namely a push-pull full-wave circuit.
Fig. 9 is a schematic diagram of a circuit topology example of a series simultaneous power supply forward cycle conversion type single-stage multi-input high-frequency link inverter circuit, i.e., a push-pull bridge circuit.
Fig. 10 is a schematic diagram of a three-push-pull forward full-wave circuit of a circuit topology example of a series simultaneous power supply forward cyclic conversion type single-stage multi-input high-frequency link inverter.
Fig. 11 is a schematic diagram of a circuit topology example of a series simultaneous power supply forward cycle conversion type single-stage multi-input high-frequency link inverter, i.e., a push-pull forward bridge circuit.
Fig. 12 is a schematic diagram of a five-half-bridge full-wave circuit of a circuit topology example of a series simultaneous power supply forward cycle conversion type single-stage multiple-input high-frequency link inverter.
Fig. 13 is a schematic diagram of a six-half bridge circuit of a circuit topology example of a series simultaneous power supply forward cycle conversion type single-stage multiple-input high-frequency link inverter.
Fig. 14 is a seven-full-bridge full-wave circuit schematic diagram of a circuit topology example of a series simultaneous power supply forward cycle conversion type single-stage multi-input high-frequency link inverter.
Fig. 15 is a schematic diagram of a circuit topology example of a series simultaneous power supply forward cycle conversion type single-stage multi-input high-frequency link inverter, namely an eight-full bridge circuit.
Fig. 16 is a block diagram of energy management control of output voltage and input current instantaneous value feedback bipolar phase shift master-slave power distribution of a series simultaneous power supply forward cycle conversion type single-stage multiple-input high-frequency link inverter.
Fig. 17 is a waveform diagram of the output voltage and input current instantaneous value feedback bipolar phase shift master-slave power distribution energy management control principle of the series simultaneous power supply forward cycle conversion type single-stage multiple-input high-frequency link inverter.
Fig. 18 is a block diagram of energy management control of output voltage and input current instantaneous value feedback unipolar phase shift master-slave power distribution of a series simultaneous power supply forward cycle conversion type single-stage multiple-input high-frequency link inverter.
Fig. 19 is a waveform diagram of the output voltage and input current instantaneous value feedback unipolar phase shift master-slave power distribution energy management control principle of the series simultaneous power supply forward cycle conversion type single-stage multiple-input high-frequency link inverter.
Fig. 20 shows a series simultaneous power supply forward cycle conversion type single-stage multiple-input high-frequency link independent power supply system with a single-stage isolated bidirectional charge-discharge converter connected in parallel at the output end.
Fig. 21, maximum power output energy management control strategy with single stage isolated bidirectional charge-discharge converter output voltage independent control loop.
FIG. 22, output voltage u of independent power supply systemoAnd outputting the filtered inductor current iLf、iLf' waveform.
Detailed Description
The technical solution of the present invention is further described below with reference to the drawings and examples of the specification.
A series simultaneous power supply forward cycle conversion type single-stage multiple-input high-frequency link inverter is composed of a multiple-input single-output high-frequency inverter circuit, multiple input filters not connected to the ground and a shared output high-frequency isolating transformer cycle conversion filter circuit, multiple input ends of the multiple-input single-output high-frequency inverter circuit are connected with the output end of each input filter in one-to-one correspondence, the output end of the multiple-input single-output high-frequency inverter circuit is connected with the input end of the high-frequency transformer of the output high-frequency isolating transformer cycle conversion filter circuit, the multiple-input single-output high-frequency inverter circuit is composed of a multi-path series simultaneous selection power switch circuit and a bidirectional power flow single-input single-output high-frequency inverter circuit, the multi-path series selection power switch circuit and the bidirectional power flow single-input single-output high-frequency inverter circuit are sequentially cascaded, and the multi-, each series simultaneous selection power switch circuit is composed of a two-quadrant power switch and a power diode, the source electrode of the two-quadrant power switch is connected with the cathode of the power diode, the drain electrode of the two-quadrant power switch and the anode of the power diode are respectively the positive and negative polarity input ends of the series simultaneous selection power switch circuit, the source electrode of the two-quadrant power switch and the anode of the power diode are respectively the positive and negative polarity output ends of the series simultaneous selection power switch circuit, the output high-frequency isolation transformation cycle conversion filter circuit is composed of a high-frequency transformer, a cycle converter and an output filter which are sequentially cascaded, and the cycle converter is composed of a plurality of four-quadrant high-frequency power switches capable of bearing bidirectional voltage stress and bidirectional current stress.
Schematic block diagrams, circuit structures, and stable-state principle waveforms of the series simultaneous power supply forward cycle conversion type single-stage multi-input high-frequency link inverter and the bipolar phase shift control and unipolar phase shift control inverter are respectively shown in fig. 4, 5, 6, and 7. In FIGS. 4, 5, 6 and 7, Ui1、Ui2、…、UinInputting a DC voltage source (n is a natural number greater than 1) for n paths, ZLFor single-phase output AC loads (including single-phase AC passive loads and single-phase AC grid loads), uo、ioRespectively single-phase output alternating voltage and alternating current. The n-input single-output high-frequency inverter circuit is formed by sequentially cascading a multi-path series simultaneous selection power switch circuit and a bidirectional power flow single-input single-output high-frequency inverter circuit which are connected in series in the forward direction of an output end, wherein the input end is connected with the output end in series, and the output end is connected withThe output end forward series connected multi-path series connection simultaneous selection power switch circuit is composed of n two-quadrant high-frequency power selection switches S capable of bearing unidirectional voltage stress and bidirectional current stresss1、Ss2、…、SsnAnd n selection diodes Ds1、Ds2、…、DsnConstitution (Power selection switch Ss1、Ss2、…、SsnSimultaneous switching-on or switching-on with phase difference, with identical or different switching frequencies, where only S is analyseds1、Ss2、…、SsnThe control mode that the two-way power flow single-input single-output high-frequency inverter circuit adopts the same switching frequency and is simultaneously switched on) is formed by a plurality of two-quadrant high-frequency power switches capable of bearing unidirectional voltage stress and bidirectional current stress, and power devices such as an MOSFET (metal oxide semiconductor field effect transistor), an IGBT (insulated gate bipolar transistor), a GTR (GTR) and the like can be selected; the output high-frequency isolation transformation cycle conversion filter circuit is formed by sequentially cascading a high-frequency transformer, a cycle converter and an output filter, wherein the cycle converter is realized by a plurality of four-quadrant high-frequency power switches capable of bearing bidirectional voltage stress and bidirectional current stress, and only a circuit diagram of an LC output filter suitable for a passive alternating current load is drawn in a space diagram, but a circuit diagram of an L or LCL output filter suitable for an alternating current power grid load is not drawn; the n-path input filter is an LC filter (filter inductor L with an added virtual frame)i1、Li2、…、Lin) Or a capacitor filter (filter inductor L without adding a virtual frame)i1、Li2、…、Lin) When an LC filter is adopted, the n input direct current paths are smoother.
The n-input single-output high-frequency inverter circuit inputs n paths of direct-current voltage sources Ui1、Ui2、…、UinModulating to bipolar two-state or unipolar three-state multi-level SPWM voltage wave u with amplitude changing along with number of input power suppliesABOr uA′B′The voltage wave u is demodulated into a bipolar two-state or unipolar three-state multi-level SPWM voltage wave u through a high-frequency transformer T isolation voltage transformation and a cycle converterCDIs passed through an output filter Lf-CfThen high-quality sine alternating voltage u is obtained on the single-phase alternating current passive load or the single-phase alternating current networkoOr sine alternating currentStream ioN input pulse currents of n-input single-output high-frequency inverter circuit are input to a filter Li1-Ci1、Li2-Ci2、…、Lin-CinOr Ci1、Ci2、…、CinThen inputting a direct current power supply U in n pathsi1、Ui2、…、UinTo obtain a smooth input direct current Ii1、Ii2、…、Iin. It should be added that the bipolar two-state multilevel high-frequency voltage square wave and the bipolar three-state multilevel SPWM voltage wave uABOr uA′B′Has an amplitude of + -2 (U)i1+Ui2+…+Uin) (push-pull circuit), +/- (U)i1+Ui2+…+Uin) (push-pull forward, full bridge circuit), ± 1/2 (U)i1+Ui2+…+Uin) (half bridge Circuit), uCDHas an amplitude of + - (-) (U)i1N2/N1+Ui2N2/N1+…+UinN2/N1) (push-pull, push-pull forward, full bridge circuits), ± 1/2 (U)i1N2/N1+Ui2N2/N1+…+UinN2/N1) (half bridge circuit).
The series simultaneous power supply forward cycle conversion type single-stage multi-input high-frequency link inverter belongs to a step-down inverter, and n input sources can supply power to a load at the same time and in a time-sharing manner. The principle of the inverter is equivalent to the superposition of the output end voltages of a plurality of forward cycle conversion type (voltage type) single-input inverters, namely the output voltage uoAnd input direct current voltage (U)i1、Ui2、…、Uin) Turn ratio N of high frequency transformer2/N1Duty ratio (d)1、d2、…、dj、…、dn) The relationship between is uo＝[ui1(d1+dk-dj+1)+ui2(d2+dk-dj+1)+…+uij(dj+dk-dj+1)+uij+1dk+…+uikdk+uik+1dk+1+…uindn]N2/N1(unipolar phase-shift control) or uo＝[ui1(dj+1-dk+1)+ui2(dj+1-dk+1)+…+uij+1(dj+1-dk+1)+uij+2(dj+1+dj+2-2dk+1)/2+uij+3(dj+1+dj+3-2dk+1)/2+…+uik(dj+1+dk-2dk+1)/2+uik+1(dj+1-dk+1)/2+…+uin(dj+1-dk+1)/2]N2/N1(bipolar phase shift control), wherein j is more than or equal to 1, and k is more than or equal to n. For proper phase shift angle theta and high frequency transformer turn ratio N2/N1，uoCan be more than, equal to or less than the sum U of the input direct current voltagesi1+Ui2+…+UinThe high-frequency transformer in the inverter not only improves the safety reliability and the electromagnetic compatibility of the operation of the inverter, but also plays a role in matching the output voltage with the input voltage, namely, the output voltage of the inverter is higher than, equal to or lower than the sum U of the input direct-current voltagesi1+Ui2+…+UinThe application range of the method is greatly widened. Because 0 ≦ theta ≦ 180oCan push out uo＜(Ui1+Ui2+…+Uin)N2/N1I.e. the output voltage uoIs always lower than the input DC voltage (U)i1、Ui2、…、Uin) Turn ratio N of high-frequency transformer2/N1Sum of products (U)i1+Ui2+…+Uin)N2/N1(ii) a The inverter belongs to a single-stage circuit structure, the working frequency of a transformer of the inverter is high frequency, and the n-input single-output high-frequency inverter circuit is provided with a plurality of paths of series simultaneous selection power switch circuits with output ends connected in series in a forward direction, so the inverter is called a series simultaneous power supply forward cycle conversion (voltage reduction type) single-stage multi-input high-frequency link inverter. The n input sources of the inverter supply power to the output AC load simultaneously or in time division within a high-frequency switching period, and the duty ratio can be in phaseIn the same way (d)1＝d2＝…＝dn) Or may be different (d)1≠d2≠…≠dn)。
The series simultaneous power supply forward cycle conversion type single-stage multi-input high-frequency link inverter disclosed by the invention shares a multi-input single-output high-frequency inverter circuit and an output high-frequency isolation transformation cycle conversion filter circuit, and is essentially different from the circuit structure of the traditional multi-input inverter formed by two-stage cascade connection of a direct-current converter and an inverter. Therefore, the inverter has novelty and creativity, and has the advantages of high-frequency isolation of output and input, simultaneous or time-sharing power supply of a multi-input power supply, simple circuit topology, single-stage power conversion, large step-up ratio, flexible input voltage preparation, high conversion efficiency (meaning small energy loss), small output voltage ripple, small output capacity, low cost, wide application prospect and the like, is an ideal energy-saving and consumption-reducing single-stage multi-input inverter, and has important value in the present of vigorously advocating the construction of energy-saving and conservation-oriented society.
Series simultaneous supply forward cycle conversion type single-stage multi-input high-frequency link inverter circuit topology family embodiments are shown in fig. 8, 9, 10, 11, 12, 13, 14 and 15. In the circuits shown in fig. 8-15, the multi-path series simultaneous selection power switch circuit with the output end connected in series in the forward direction is composed of n two-quadrant high-frequency power switches and n diodes, the bidirectional power flow single-input single-output high-frequency inverter circuit is composed of a plurality of two-quadrant high-frequency power switches capable of bearing unidirectional voltage stress and bidirectional current stress (the push-pull, push-pull forward and half-bridge circuits shown in fig. 8, 9, 10, 11, 12 and 13 are composed of 2 two-quadrant high-frequency power switches, the full-bridge circuit shown in fig. 14 and 15 is composed of 4 two-quadrant high-frequency power switches), and the output cycle conversion circuit is realized by a plurality of four-quadrant high-frequency power switches. Specifically, the push-pull full-wave, push-pull forward full-wave, and half-bridge full-wave circuits shown in fig. 8, 10, and 12 are implemented by n +2 two-quadrant high-frequency power switches capable of bearing unidirectional voltage stress and bidirectional current stress, n diodes, and 2 four-quadrant high-frequency power switches capable of bearing bidirectional voltage stress and bidirectional current stress, the push-pull bridge, push-pull forward bridge, and half-bridge circuits shown in fig. 9, 11, and 13 are implemented by n +2 two-quadrant high-frequency power switches capable of bearing unidirectional voltage stress and bidirectional current stress, n diodes, 4 four-quadrant high-frequency power switches capable of bearing bidirectional voltage stress and bidirectional current stress, and the full-bridge circuits shown in fig. 14 and 15 are respectively implemented by 2, 4 four-quadrant high-frequency power switches capable of bearing bidirectional voltage stress and bidirectional current stress, and n +4 four-quadrant high-frequency power switches capable of bearing unidirectional voltage stress and bidirectional current stress, A two-quadrant high-frequency power switch with bidirectional current stress and n diodes. It should be added that, the circuits shown in fig. 8, 9, 10, 11, 12, 13, 14, and 15 show the case where the input filter is an LC filter, and are limited to the case where the input filter is not a capacitive filter; the push-pull forward circuits of fig. 10 and 11 and the half-bridge circuits of fig. 12 and 13 are only suitable for the case where the duty cycles of the n input power sources are substantially equal; the circuits shown in fig. 8-15 only show the circuit diagram of an LC output filter for passive ac loads, and not the circuit diagram of an L or LCL output filter for ac grid loads. The power switch voltage stress of eight topological embodiments of the forward cycle conversion type single-stage multi-input high-frequency link inverter with simultaneous power supply in series is shown in table 1. The push-pull and push-pull forward circuits are suitable for medium-power low-voltage input inversion occasions, the half-bridge circuit is suitable for low-power high-voltage input inversion occasions, and the full-bridge circuit is suitable for medium-power high-voltage input inversion occasions. The circuit topology family is suitable for converting a plurality of common-ground unstable input direct-current voltages into a stable and high-quality output alternating current with a required voltage, and can be used for realizing a novel single-stage multiple new energy distributed power supply system with excellent performance and wide application prospect, such as photovoltaic cells 40-60VDC/220V50HzAC or 115V400HzAC, 10kw proton exchange membrane fuel cells 85-120V/220V50HzAC or 115V400HzAC, medium and small sized users 24-36-48VDC/220V50HzAC or 115V400HzAC, large wind power generation 510VDC/220V50HzAC 115V400HzAC and other multiple input sources for supplying power to alternating current loads or alternating current power grids.
TABLE 1 series simultaneous power supply forward cycle conversion type single-stage multiple-input high-frequency link inverter power switch voltage stress of eight topology embodiments
The energy management control strategy is crucial to various new energy combined power supply systems. Due to the presence of multiple input sources and corresponding power switching units, multiple duty cycles need to be controlled, i.e. there are multiple degrees of freedom of control, which provides the possibility for energy management of multiple new energy sources. An energy management control strategy of a series simultaneous power supply forward cycle conversion type single-stage multi-input high-frequency link inverter needs to have three functions of energy management of an input source, MPPT (maximum power point tracking) and output voltage (current) control of new energy power generation equipment such as a photovoltaic cell and a wind driven generator, and sometimes, charge and discharge control of a storage battery and smooth and seamless switching of a system under different power supply modes need to be considered. The series simultaneous power supply forward cycle conversion type single-stage multi-input high-frequency link inverter adopts two different energy management modes: (1) in the energy management mode I, namely a master-slave power distribution mode, the power required by a load is known to be provided by the 1 st, 2 nd, … th and n-1 st input sources of the master power supply equipment as much as possible, the input current of the 1 st, 2 nd, … th and n-1 st input sources is given, which is equivalent to the input power of the 1 st, 2 nd, … th and n-1 st input sources, the insufficient power required by the load is provided by the nth input source of the slave power supply equipment, and a storage battery energy storage device does not need to be added; (2) in the energy management mode II, namely the maximum power output mode, the 1 st input source, the 2 nd input source, the … th input source and the n th input source are all output to a load with the maximum power, storage battery energy storage equipment is omitted, the requirement of a grid-connected power generation system on the full utilization of energy is met, and if an output end is connected with a storage battery charging and discharging device in parallel, the stability of the output voltage (current) of an independent power supply system can be realized. When the input voltage of the n paths of new energy sources is given, the input current of the 1 st, 2 nd, … th and n paths of input sources is controlled, so that the input power of the 1 st, 2 nd, … th and n paths of input sources is controlled.
Series simultaneous power supply forward cycle conversion typeThe single-stage multi-input high-frequency link inverter adopts an energy management control strategy of bipolar phase shift and unipolar phase shift master-slave power distribution of output voltage and input current instantaneous value feedback to form an independent power supply system; or an input current instantaneous value feedback bipolar phase shift and unipolar phase shift maximum power output energy management control strategy is adopted to form a grid-connected power generation system. The 1 st, 2 nd, … th and n-1 st input sources output power is fixed, and the nth input sources supplement the output voltage and input current instantaneous value of the insufficient power needed by the load, and the bipolar SPWM and unipolar SPWM master-slave power distribution energy management control block diagram and the control principle waveform are respectively shown in FIGS. 16, 17, 18 and 19. The basic idea of the bipolar phase-shifting control scheme shown in fig. 16 and 17 is that an n-input single-output high-frequency inverter circuit generates a bipolar two-state multi-level high-frequency square wave, the conduction time of the 1 st, 2 nd, … th and n-1 th path selection power switches is distributed according to the magnitude of error current (realizing the maximum power output of the 1 st, 2 nd, … th and n-1 th path input sources), and the conduction time of the n-th path power switch is based on a signal smaller than the n-1 th path error current signal and TsThe difference between the conduction time of the power switch of the 1 st path and the conduction time of the power switch of the 1 st path is obtained (the complement of the power of the input source of the nth path is realized), multiple paths or one path of input sources are always connected at any moment, the forward transmission of the energy of the multiple paths of input sources is ensured, the natural path of energy feedback is formed by connecting n input sources in series, the stabilization of the output voltage of the inverter is realized through the phase shift between the cycle converter and the n input single output high frequency inverter circuit, the natural current conversion of the leakage inductance energy of the high frequency transformer and the zero current switch of the cycle converter are realized by the current conversion overlapping of the cycle converter, and the control strategy is suitable for the. The 1 st, 2 nd, … th and n-1 th input sources are calculated by the maximum power point to obtain a reference current signal I＊ i1r、I＊ i2r、…、I＊ i(n-1)rInput current feedback signal I of inverter circuit 1, 2, … and n-1i1f、Ii2f、…、Ii(n-1)fReference current signal I with No. 1, No. 2, No. … and No. n-1i1r、Ii2r、…、Ii(n-1)rThe signals are compared and amplified by a proportional-integral regulator, and the current error is amplifiedNumber I1e、I2e、…、I(n-1)e、kI(n-1)e(k is more than 0 and less than 1) and the shifted unipolar sawtooth-shaped carrier wave-uc+UcmThe control signal u of the power switch is selected while the series connection of the n-input single-output high-frequency inverter circuit is obtained after the comparison of/2 and a proper combinational logic circuitgss1、ugss2、…、ugssn(ii) a Bipolar sawtooth carrier ucObtaining a control signal u of the power switch of the n-input single-output high-frequency inverter circuit after the rising edge is subjected to frequency division by twogs1(ugs4) And its inverse signal ugs2(ugs3) (ii) a Output voltage feedback signal u of inverterofWith reference sinusoidal voltage urThe signal u is compared and amplified by a proportional-integral regulator and the voltage error is amplifiedeRespectively associated with bipolar sawtooth-shaped carriers ucAnd-ucBy comparison, taking into account the output inductor current iLfThe polarity selection signal is processed by a proper combinational logic circuit to obtain a control signal u of a power switch of the cycloconvertergs5(ugs′5)、ugs6(ugs′6)、ugs7(ugs′7)、ugs8(ugs′8). When the load power PoWhen the output voltage is larger than the sum of the maximum powers of the 1 st, 2 nd, … th and n-1 th input sourcesoReducing, the voltage regulator output voltage ueIs greater than the threshold comparison level UtAnd I1e、I2e、…、I(n-1)eAre all greater than zero, diode D1、D2、…、Dn-1Blocking, the 1 st, 2 nd, … th, n-1 th current regulators and the nth voltage regulator work independently, i.e. Ii1r＝I＊ i1r、Ii2r＝I＊ i2r、…、Ii(n-1)r＝I＊ i(n-1)rThe 1 st, 2 nd, … th and n-1 th circuit current regulators are used for realizing the maximum power output of the 1 st, 2 nd, … th and n-1 th input sources, the nth circuit voltage regulator is used for realizing the stability of the output voltage of the inverter, and the n-th input sources supply power to the load at the same time or in a time-sharing manner; when the load power PoWhen the output voltage is less than the sum of the maximum powers of the 1 st, 2 nd, … th and n-1 th input sourcesoIncrease when the voltage regulator output voltage ueIs reduced to a threshold comparison level UtWhen following, diode Dn-1On, D1、D2、…、Dn-2When the input voltage is still blocked, the hysteresis comparison circuit n +1 outputs low level, the nth input source stops supplying power, the voltage regulator and the current regulator form a double closed loop control system, the 1 st, 2 nd, … th and n-1 th input sources simultaneously or time-divisionally supply power to a load in a switching period, and the reference current I of the current regulatori(n-1)rDecrease, i.e. Ii(n-1)r＜I＊ i(n-1)rThe output power of the (n-1) th input source is reduced (working at a non-maximum working point), the output power of the (n) th input source is reduced to zero, and the output voltage u of the inverter is reducedoAnd tends to be stable. By regulating the reference voltage u as the input voltage or load variesrOr the feedback voltage uofTo change the error voltage signal ueAnd an error current signal I1e、I2e、…、I(n-1)e、kI(n-1)eThereby changing the duty ratio d1、d2、…、dnAnd a phase shift angle theta, so that the regulation and stabilization of the output voltage and the input current (output power) of the inverter can be realized.
The basic idea of the unipolar phase shift control scheme shown in fig. 18 and 19 is that a bipolar tri-state multi-level SPWM wave is generated by phase shift between a right bridge arm and a left bridge arm of an n-input single-output high-frequency inverter circuit, the bipolar tri-state multi-level SPWM wave is demodulated into a unipolar tri-state multi-level SPWM wave by a cycle wave converter, the cycle wave converter performs switching conversion during a period when the bipolar tri-state multi-level SPWM wave output by the high-frequency inverter circuit is zero, so as to implement zero voltage switching, multiple or one input source access (a "1" state or a "-1" state, forward transmission or reverse feedback of energy is ensured) or a 0 state (a continuous flow state) always exists at any time, and a natural path of energy feedback is formed by connecting n input sources in series, and the control strategy is only applicable to the circuits shown in fig. The conduction time of the 1 st, 2 nd, … th and n-1 st path selection power switches is the OR signal u of the conduction signals of the left bridge arm and the right bridge arm distributed according to SPWM according to the magnitude of error currentsumMake the assignment (realize 1 st, 2 nd, … th, n-1 st)Maximum power output of the input source), and the conducting time of the nth power switch is obtained according to the signal distribution of the error current signal which is smaller than the nth-1 (realizing the complement of the nth input source power). The 1 st, 2 nd, … th and n-1 th input sources are calculated by the maximum power point to obtain a reference current signal I＊ i1r、I＊ i2r、…、I＊ i(n-1)rInput current feedback signal I of inverter circuit 1, 2, … and n-1i1f、Ii2f、…、Ii(n-1)fReference current signal I with No. 1, No. 2, No. … and No. n-1i1r、Ii2r、…、Ii(n-1)rComparing and amplifying by a proportional-integral regulator, and amplifying a current error signal I1e、I2e、…、I(n-1)e、kI(n-1)e(0 < k < 1) respectively passing through divider, multiplier, comparator and appropriate logic circuit to obtain control signal u of power switch selected in series of n-input single-output high-frequency inverter circuitgss1、ugss2、…、ugssn(ii) a Output voltage feedback signal u of inverterofWith reference sinusoidal voltage urComparing and amplifying the signals by a proportional-integral regulator, and amplifying a voltage error signal ueAnd its inverse signal-ueRespectively associated with bipolar sawtooth-shaped carriers ucComparing, obtaining the power switch control signal u of the n-input single-output high-frequency inverter circuit after the falling edge frequency division and the NOT circuitgs1、ugs2、ugs3、ugs4(ii) a U in the figuresumOR signal, U, representing the conduction signals of the left and right arms of the n-input single-output high-frequency inverter circuitsummIs usumAmplitude of level of (I)1emAmplifying a signal I for a current error1eMaximum value of (d); bipolar sawtooth carrier ucObtaining a control signal u of a power switch of the cycloconverter after the rising edge is subjected to frequency division by twogs5(ugs′5)、ugs6(ugs′6)、ugs7(ugs′7)、ugs8(ugs′8)。
The 1 st, 2 nd, … th, n-1 th circuit current regulators and the n-1 th circuit voltage regulators work independently respectively, and the 1 st, 2 nd, … th and n-1 th circuit current regulators work independentlyThe current regulator is used for realizing the maximum power output of the 1 st, 2 nd, … th and n-1 st input sources, the nth circuit voltage regulator is used for realizing the stabilization of the output voltage of the inverter, and the nth input sources supply power to the load simultaneously or in a time-sharing manner. By regulating the reference voltage u as the input voltage or load variesrAnd a reference current Ii1r、Ii2r、…、Ii(n-1)rOr regulating the feedback voltage uofAnd a feedback current Ii1f、Ii2f、…、Ii(n-1)fTo change the error voltage signal ueAnd an error current signal I1e、I2e、…、I(n-1)e、kI(n-1)eThereby changing the duty ratio d1、d2、…、dnAnd a phase shift angle theta, so that the regulation and stabilization of the output voltage and the input current (output power) of the inverter can be realized.
The waveform of the bipolar phase-shift control principle shown in FIG. 17 marks the high-frequency switching period TSAnd a certain high frequency switching period TSConduction time T of internal 1 st, 2 nd, … th input sourceon1、Ton2、…、Tonn(Ton1＞Ton2＞…＞Tonn) And total on-time Ton＝TS/2, common conduction time T of bipolar and unipolar phase shift control shown in FIGS. 17 and 19comAnd the phase shift angle theta varies sinusoidally within one output voltage period. In the half-bridge circuit shown in fig. 12 and 13, half of the input dc voltage value (U) should be usedi1/2、Ui2/2、…、UinAnd/2) substituting into the voltage transfer ratio for calculation.
In order to form an independent power supply system capable of fully utilizing energy of multiple input sources, multiple input sources should operate in a maximum power output mode and energy storage equipment needs to be configured to achieve stabilization of output voltage, that is, a single-stage isolation bidirectional charge-discharge converter is connected in parallel to an output end of an inverter, as shown in fig. 20. The single-stage isolation bidirectional charge-discharge converter consists of an input filter (L)i、CiOr Ci) High-frequency inverter, high-frequency transformer, cycle converter, output filter (L)f′、Cf') sequential stagesThe cycle converter is composed of a four-quadrant high-frequency power switch capable of bearing bidirectional voltage stress and bidirectional current stress. The single-stage isolation bidirectional charge-discharge converter is respectively equivalent to a single-stage high-frequency link DC-AC converter and a single-stage high-frequency link AC-DC converter when energy is transmitted in the forward direction (energy storage equipment is discharged) and transmitted in the reverse direction (energy storage equipment is charged).
The independent power supply system adopts a maximum power output energy management control strategy with a single-stage isolated bidirectional charge-discharge converter output voltage independent control loop, as shown in fig. 21. When the load power Po＝UoIoGreater than the sum P of the maximum powers of the plurality of input sources1max+P2max+…+PnmaxWhen the power supply is started, energy storage equipment such as a storage battery, a super capacitor and the like provides needed insufficient power to a load through a single-stage isolation bidirectional charge-discharge converter, namely a power supply mode II, and the energy storage equipment independently provides power to the load, namely a power supply mode III, and belongs to the extreme situation of the power supply mode II; when the load power Po＝UoIoLess than the sum P of the maximum powers of the plurality of input sources1max+P2max+…+PnmaxAnd in the time, the residual energy output by the plurality of input sources is used for charging the energy storage equipment through the single-stage isolation bidirectional charging and discharging converter, namely, the power supply mode I. Using the band elimination load as an example, the power flow direction control of the single-stage isolated bidirectional charge-discharge converter is discussed, as shown in fig. 22. For output filter capacitor Cf、Cf' and load ZLIn other words, the parallel connection of the output ends of the series simultaneous power supply forward cycle conversion type single-stage multi-input high-frequency link inverter and the single-stage isolation bidirectional charge-discharge converter is equivalent to the parallel superposition of two current sources. As can be seen from the energy management control strategy shown in FIG. 21, the output filter inductor current i of the series simultaneous power supply forward cycle conversion type single-stage multi-input high-frequency link inverterLfAnd the output voltage uoThe same frequency and the same phase are adopted, and active power is output; the charging and discharging converter is controlled by the output voltage uoAnd a reference voltage uorefError amplified signal uoeIntercepting with high frequency carrier to generate SPWM signal for control, outputting filter inductor current iLf' and uoThere is a phase difference theta between them, and different phase differences theta mean that active power with different magnitude and direction is output. When P is presento＝P1max+P2max+…+PnmaxWhen theta is equal to 90 degrees, the active power output by the charge-discharge converter is zero, and the charge-discharge converter is in an idle state; when P is presento>P1max+P2max+…+PnmaxWhen u is turned onoThe theta is reduced to be less than 90 degrees, the charging and discharging converter outputs active power, and the energy storage equipment discharges to the load, namely the energy storage equipment provides insufficient power required by the load; when P is presento＜P1max+P2max+…+PnmaxWhen u is turned onoAnd increasing theta to be more than 90 degrees, outputting negative active power by the charging and discharging converter, feeding energy back to the energy storage device by the load, namely charging the energy storage device by residual power output by the plurality of input sources, and feeding the energy back to the energy storage device by the load to be the maximum when the theta is 180 degrees. Thus, the energy management control strategy can be based on PoAnd P1max+P2max+…+PnmaxThe relative size of the single-stage isolation bidirectional charge-discharge converter controls the power flow size and direction of the single-stage isolation bidirectional charge-discharge converter in real time, and smooth and seamless switching of the system under three different power supply modes is realized.
Claims (2)
1. The utility model provides a series connection is power supply forward cycle conversion type single-stage multiple input high frequency link inverter simultaneously which characterized in that: the inverter is formed by sequentially cascading a bidirectional power flow n-input single-output series simultaneous selection power switch circuit, a bidirectional power flow single-input single-output high-frequency inverter circuit, a high-frequency transformer, a cycle converter and an output filter, wherein each input end of the bidirectional power flow n-input single-output series simultaneous selection power switch circuit is cascaded with one input filter, no common end exists among the n input filters, n is the number of multiple input sources, and n is a natural number greater than 1; the bidirectional power flow n-input single-output series simultaneous selection power switch circuit is formed by connecting n paths of bidirectional power flow in series while selecting the power switch circuit in a positive polarity output end and a negative polarity output end of each path in series, and each path of bidirectional power flow in series while selecting the power switch circuit is formed by selecting two-quadrant power capable of bearing unidirectional voltage stress and bidirectional current stressThe power selection circuit comprises a selection switch and a power selection diode, wherein the source electrode of a two-quadrant power selection switch is connected with the cathode of the power selection diode, the drain electrode of the two-quadrant power selection switch and the anode of the power selection diode are respectively used as the positive and negative input ends of the bidirectional power flow series connection simultaneous selection power switch circuit, and the source electrode of the two-quadrant power selection switch and the anode of the power selection diode are respectively used as the positive and negative output ends of the bidirectional power flow series connection simultaneous selection power switch circuit; the bidirectional power flow single-input single-output high-frequency inverter circuit is a push-pull type, push-pull forward type, half-bridge type or full-bridge type circuit, the push-pull type circuit is composed of two quadrant high-frequency power switches bearing unidirectional voltage stress and bidirectional current stress, the source electrodes of the two quadrant high-frequency power switches are connected with the negative polarity output end of the series simultaneous selection power switch circuit, the drain electrodes of the two quadrant high-frequency power switches are respectively connected with two different ends of a primary winding of a high-frequency transformer, a center tap of the primary winding of the high-frequency transformer is connected with the positive polarity output end of the series simultaneous selection power switch circuit, the push-pull forward type circuit is composed of two quadrant high-frequency power switches bearing unidirectional voltage stress and bidirectional current stress and a clamping capacitor, the drain electrode and the source electrode of one two quadrant high-frequency power switch are respectively connected with the non-end of one primary winding of the high-frequency transformer and the-end of the other primary winding, and the positive output end of the selective power switch circuit is connected, the drain and source of another two-quadrant high-frequency power switch are respectively connected with the "·" end of one primary winding of the high-frequency transformer and the "·" end of another primary winding, and its source is connected with the negative output end of the series connection simultaneous selective power switch circuit, two ends of the clamping capacitor are respectively connected with the "·" ends of two primary windings of the high-frequency transformer, the half-bridge circuit is formed from two capacitors of left bridge arm and two high-frequency power switches of right bridge arm which bear unidirectional voltage stress and bidirectional current stress, and the drain and source of the right upper bridge arm switch are respectively connected with the positive end of the left upper bridge arm capacitor and the drain of the right lower bridge arm switch, the source of the right lower bridge arm switch is connected with the negative end of the left lower bridge arm capacitor, andtwo ends of a primary winding of the high-frequency transformer are respectively connected with the midpoint of a right bridge arm switch and the midpoint of a left bridge arm capacitor, a full-bridge circuit is composed of four two-quadrant high-frequency power switches bearing unidirectional voltage stress and bidirectional current stress of a left bridge arm, a right bridge arm or an upper bridge arm and a lower bridge arm, drain electrodes of the two upper bridge arm switches are connected with a positive polarity output end of a series connection simultaneous selection power switch circuit, source electrodes of the two lower bridge arm switches are connected with a negative polarity output end of the series connection simultaneous selection power switch circuit, one end of the primary winding of the high-frequency transformer is connected with the source electrode of the left upper bridge arm switch and the drain electrode of the left lower bridge arm switch, and the other end of the primary winding; the cycle converter is a full-wave and full-bridge circuit, the full-wave cycle converter is composed of two four-quadrant high-frequency power switches bearing bidirectional voltage stress and bidirectional current stress, one drain electrode of the two four-quadrant high-frequency power switches is respectively connected with two different ends of a secondary winding of the high-frequency transformer, the other drain electrode of the two four-quadrant high-frequency power switches and a center tap of the secondary winding of the high-frequency transformer are connected with the input end of an output filter, the full-bridge cycle converter is composed of four-quadrant high-frequency power switches bearing bidirectional voltage stress and bidirectional current stress of a left bridge arm, a right bridge arm or an upper bridge arm and a lower bridge arm, the drain electrodes of the two upper bridge arm switches and the drain electrodes of the two lower bridge arm switches are respectively connected with two different ends of the secondary winding of the high-frequency transformer, and the other drain electrodes of the left upper bridge arm switch and the left lower bridge arm switch and the other drain electrodes of the right upper bridge arm switch and the right lower bridge arm switch are connected with the input end of the output filter; the bidirectional power flow n-input single-output series simultaneous selection power switch circuit and the bidirectional power flow single-input single-output high-frequency inverter circuit of the inverter input n paths of direct-current voltage sources U into the inverteri1、Ui2、…、UinModulating into bipolar two-state multi-level high-frequency voltage square wave or bipolar three-state multi-level SPWM voltage wave with level amplitude changing with input power supply number, demodulating into bipolar two-state or unipolar three-state multi-level SPWM voltage wave through high-frequency transformer isolation voltage transformation and cycle converter, obtaining high-quality sinusoidal AC voltage on single-phase AC load after passing through output filterOr grid-connected sine current, and the voltage wave level amplitudes before and after the push-pull circuit demodulation are respectively +/-2 (U)i1+Ui2+…+Uin)、±(Ui1N2/N1+Ui2N2/N1+…+UinN2/N1) The voltage wave level amplitudes before and after the demodulation of the push-pull forward circuit and the full-bridge circuit are respectively +/-Ui1+Ui2+…+Uin)、±(Ui1N2/N1+Ui2N2/N1+…+UinN2/N1) The voltage wave level amplitudes before and after the half-bridge circuit demodulation are respectively +/-1/2 (U)i1+Ui2+…+Uin)、±1/2(Ui1N2/N1+Ui2N2/N1+…+UinN2/N1)，N1、N2The number of turns of a primary winding and the number of turns of a secondary winding of the high-frequency transformer are respectively; the voltage stress of the 1 st, 2 nd, … th power selection switch and the n-way power selection diode is U respectivelyi1、Ui2、…、UinThe voltage stress of the two-quadrant power switch of the push-pull type and push-pull forward type, half-bridge type and full-bridge type high-frequency inverter circuits is respectively 2 (U)i1+Ui2+…+Uin)、Ui1+Ui2+…+UinThe voltage stress of the two-quadrant power switch of the full-wave and full-bridge cycloconverters of the push-pull, push-pull forward and full-bridge circuits is respectively 2 (U)i1+Ui2+…+Uin)N2/N1、(Ui1+Ui2+…+Uin)N2/N1The voltage stress of the two-quadrant power switch of the full-wave and full-bridge cycloconverter of the half-bridge circuit is (U)i1+Ui2+…+Uin)N2/N1、(Ui1+Ui2+…+Uin)N2/(2N1) (ii) a The independent power supply system formed by the inverter adopts the output voltage and input current instantaneous values of the output power of the No. 1, No. 2, No. … and the No. 1 input source with the n input source power supply smooth switching function and the output power required by the No. n input source to supplement the load to feed back the bipolar powerThe grid-connected power generation system formed by the inverters adopts a SPWM control strategy of maximum power output energy management of bipolar phase shift and unipolar phase shift fed back by instantaneous values of input currents of input sources of 1 st, 2 nd, … th paths and n paths; the control strategy of the bipolar phase-shifting master-slave power distribution energy management SPWM is that the front n-1 paths of input sources of the inverter output a reference current signal I through the maximum power point calculation＊ i1r、I＊ i2r、…、I＊ i(n-1)rFront n-1 input current feedback signal Ii1f、Ii2f、…、Ii(n-1)fRespectively with the front n-1 base quasi-current signal Ii1r、Ii2r、…、Ii(n-1)rThe amplified signal is compared and amplified by a proportional-integral regulator to output a current error amplified signal I1e、I2e、…、I(n-1)e、kI(n-1)eRespectively with shifted unipolar sawtooth-shaped carrier-uc+Ucm2 comparison and output of control signal u in series connection with simultaneous selection of power switches after passing through appropriate combinational logic circuitgss1、ugss2、…、ugssnK is more than 0 and less than 1, and a bipolar sawtooth carrier ucControl signal u of high-frequency inverter circuit power switch output by rising edge frequency divisiongs1(ugs4) And its inverse signal ugs2(ugs3) Output voltage feedback signal u of inverterofWith reference sinusoidal voltage urThe proportional-integral regulator compares and amplifies an output voltage error amplification signal ue，ueRespectively associated with bipolar sawtooth-shaped carriers ucAnd-ucComparing and considering output inductor current iLfThe polarity selection signal is output to a control signal u of a power switch of the cycloconverter after passing through a proper combinational logic circuitgs5(ugs′5)、ugs6(ugs′6)、ugs7(ugs′7)、ugs8(ugs′8) When the load power PoOutput voltage u is larger than the sum of maximum powers of the first n-1 input sourcesoReducing, voltage regulator output voltage ueIs greater than the threshold comparison level UtAnd I1e、I2e、…、I(n-1)eAre all greater than zero, diode D1、D2、…、Dn-1The blocking, front n-1 circuit current regulator and the nth circuit voltage regulator work independently respectively, i.e. Ii1r＝I＊ i1r、Ii2r＝I＊ i2r、…、Ii(n-1)r＝I＊ i(n-1)rThe front n-1 circuit current regulator is used for realizing the maximum power output of the front n-1 circuit input sources, the nth circuit voltage regulator is used for realizing the stabilization of the output voltage of the inverter, the n circuit input sources simultaneously supply power to the load, and when the load power P isoOutput voltage u less than the sum of the maximum powers of the first n-1 input sourcesoIncreasing, voltage regulator output voltage ueIs reduced to a threshold comparison level UtFollowing time diode Dn-1On, D1、D2、…、Dn-2The output of the hysteresis comparison circuit n +1 is low level, the nth input source stops supplying power, the voltage regulator and the current regulator form a double closed loop control system, the front n-1 input source simultaneously supplies power to the load in a switching period, and the reference current I of the current regulatori(n-1)rDecrease, i.e. Ii(n-1)r＜I＊ i(n-1)rThe output power of the (n-1) th input source is reduced and works at a non-maximum working point, the output power of the (n) th input source is reduced to zero, and the output voltage u of the inverteroTends to be stable; the SPWM control strategy for unipolar phase-shift master-slave power distribution energy management is that the front n-1 paths of input sources of the inverter output a reference current signal I through maximum power point calculation＊ i1r、I＊ i2r、…、I＊ i(n-1)rInput current feedback signal I of front n-1 pathi1f、Ii2f、…、Ii(n-1)fRespectively with the front n-1 base quasi-current signal Ii1r、Ii2r、…、Ii(n-1)rThe amplified signal is compared and amplified by a proportional-integral regulator to output a current error amplified signal I1e、I2e、…、I(n-1)e、kI(n-1)eWith output series-connected simultaneous selection of power switches, each passing through a divider, multiplier, comparator and appropriate logicControl signal ugss1、ugss2、…、ugssnOutput voltage feedback signal u of inverterofWith reference sinusoidal voltage urThe proportional-integral regulator compares and amplifies an output voltage error amplification signal ue，ueAnd its inverse signal-ueRespectively associated with bipolar sawtooth-shaped carriers ucComparing and outputting a power switch control signal u of the high-frequency inverter circuit after passing through a falling edge frequency-halving and NOT circuitgs1、ugs2、ugs3、ugs4K, u in control block diagramsum、Usumm、I1emRespectively representing coefficients less than 1 and greater than 0, or signals and u of conducting signals of left bridge arm and right bridge arm of high-frequency inverter circuitsumLevel amplitude, current error amplification signal I1eMaximum value of (1), bipolar sawtooth carrier ucOutputting a control signal u of a power switch of the cycloconverter after frequency division by two rising edgesgs5(ugs′5)、ugs6(ugs′6)、ugs7(ugs′7)、ugs8(ugs′8) (ii) a The inverter determines the number of input sources needing to be put into operation by controlling the connection and disconnection of n paths of bidirectional power flow series connection and simultaneously selecting the power switch according to the size of the alternating current load, and the n paths of input sources are U-shaped in one high-frequency switching periodi1+Ui2+…+Uin、Ui1+Ui2+…+Uin-1、…、Ui1The serial connection in sequence supplies power to the AC load at the same time, which realizes the single-stage high-frequency isolation high-efficiency inversion of n input DC voltages which are not common to the ground and unstable into a stable high-quality sine AC power required by the AC load.
2. The series simultaneous supply forward cycle conversion type single-stage multiple-input high-frequency link inverter according to claim 1, characterized in that: the output end of the series simultaneous power supply forward cycle conversion type single-stage multi-input high-frequency link inverter is connected with a single-stage isolation bidirectional charge-discharge converter of the energy storage device in parallel, so that an independent power supply system which can fully utilize n input source energy and has stable output voltage is formed; the single-stage isolation bidirectional charge-discharge converter is formed by sequentially cascading an input filter, a high-frequency inverter, a high-frequency transformer, a cycle converter and an output filter, wherein the cycle converter is formed by a four-quadrant high-frequency power switch capable of bearing bidirectional voltage stress and bidirectional current stress, and the single-stage isolation bidirectional charge-discharge converter is respectively equivalent to a single-stage voltage type high-frequency link DC-AC converter and a single-stage current type high-frequency link AC-DC converter when the energy storage equipment is discharged and charged; the independent power supply system adopts a management control strategy of the maximum power output energy of n input sources with a single-stage isolation bidirectional charge-discharge converter output voltage independent control loop, the n input sources all work in a maximum power output mode, the power flow size and direction of the single-stage isolation bidirectional charge-discharge converter are controlled in real time according to the relative size of the sum of the load power and the maximum power of the n input sources, and the smooth seamless switching of the output voltage of the system and the charge and discharge of energy storage equipment is realized; when the load power is greater than the sum of the maximum powers of the n input sources, the system works in a power supply mode II in which the energy storage device provides required insufficient power to the load through the single-stage isolation bidirectional charge-discharge converter, a power supply mode III in which the energy storage device supplies power to the load independently belongs to the extreme situation of the power supply mode II, and when the load power is less than the sum of the maximum powers of the n input sources, the system works in a power supply mode I in which the residual energy output by the n input sources charges the energy storage device through the single-stage isolation bidirectional charge-discharge converter; for an output filter capacitor and a load, the output ends of the forward cycle conversion type single-stage multi-input high-frequency link inverter and the single-stage isolation bidirectional charge-discharge converter which are connected in series and simultaneously supply power are connected in parallel and are equivalent to the parallel superposition of two current sources; the method comprises the steps that 1, 2, … and n paths of input source output currents are subjected to error amplification with 1, 2, … and n paths of input source maximum power point reference currents respectively, the 1 st, 2, … and n paths of error amplification signals are multiplied by sinusoidal synchronous signals and then are intersected with the same high-frequency carrier signal respectively to generate 1 st, 2 nd, … and n paths of signals to control an n path of input inverter, the n path of input inverter outputs filtering inductive currents which are in the same frequency and the same phase as output voltages and outputs active power, and SPWM signals are generated by the intersection of the error amplification signals of the system output voltages and the reference voltages and the high-frequency carrier signals to control the output filtering inductive currents and the system output voltages of the charge-discharge converter, wherein phase differences theta and different phase differences theta mean that active power with different magnitudes and directions are output; when the load power is equal to the sum of the maximum powers of the n input sources, theta is equal to 90 degrees, the active power output by the charging and discharging converter is zero, when the load power is larger than the sum of the maximum powers of the n input sources, the output voltage is reduced, theta is smaller than 90 degrees, the charging and discharging converter outputs the active power, namely the insufficient power required by the load by the energy storage device, when the load power is smaller than the sum of the maximum powers of the n input sources, the output voltage is increased, theta is larger than 90 degrees, and the charging and discharging converter outputs the negative active power, namely the residual power output by the n input sources to charge the.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810020153.0A CN108023497B (en) | 2018-01-09 | 2018-01-09 | Series simultaneous power supply forward cycle conversion type single-stage multi-input high-frequency link inverter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810020153.0A CN108023497B (en) | 2018-01-09 | 2018-01-09 | Series simultaneous power supply forward cycle conversion type single-stage multi-input high-frequency link inverter |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108023497A CN108023497A (en) | 2018-05-11 |
| CN108023497B true CN108023497B (en) | 2020-12-25 |
Family
ID=62071272
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810020153.0A Active CN108023497B (en) | 2018-01-09 | 2018-01-09 | Series simultaneous power supply forward cycle conversion type single-stage multi-input high-frequency link inverter |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108023497B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114825913A (en) * | 2021-01-18 | 2022-07-29 | 台达电子企业管理（上海）有限公司 | Power conversion system and control method thereof |
| CN113258815A (en) * | 2021-05-28 | 2021-08-13 | 青岛大学 | Single-stage bidirectional AC/DC converter with variable structure and wide output range |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1348248A (en) * | 2001-09-10 | 2002-05-08 | 南京航空航天大学 | High-frequency AC/AC converter with AC link |
| CN101534059A (en) * | 2009-04-14 | 2009-09-16 | 福州大学 | Single-isolation pressure increase and reduction type multi-input direct current converter |
| CN101588129A (en) * | 2009-06-30 | 2009-11-25 | 南京航空航天大学 | A kind of multiple input flyback converter |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101267167B (en) * | 2008-01-09 | 2010-07-21 | 福州大学 | Voltage increase high-frequency link reverser |
-
2018
- 2018-01-09 CN CN201810020153.0A patent/CN108023497B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1348248A (en) * | 2001-09-10 | 2002-05-08 | 南京航空航天大学 | High-frequency AC/AC converter with AC link |
| CN101534059A (en) * | 2009-04-14 | 2009-09-16 | 福州大学 | Single-isolation pressure increase and reduction type multi-input direct current converter |
| CN101588129A (en) * | 2009-06-30 | 2009-11-25 | 南京航空航天大学 | A kind of multiple input flyback converter |
Also Published As
| Publication number | Publication date |
|---|---|
| CN108023497A (en) | 2018-05-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10833600B2 (en) | Single-stage multi-input forward DC-DC chopper type high-frequency link's inverter with series simultaneous power supply | |
| US11128236B2 (en) | Multi-winding single-stage multi-input boost type high-frequency link's inverter with simultaneous/time-sharing power supplies | |
| US11050359B2 (en) | Single-stage multi-input buck type low-frequency link's inverter with an external parallel-timesharing select switch | |
| Liu et al. | Cascade dual-boost/buck active-front-end converter for intelligent universal transformer | |
| EP3637611B1 (en) | Voltage-type single-stage multi-input high frequency link inverter having built-in parallel time-sharing selection switches | |
| Hu et al. | Ultrahigh step-up DC–DC converter for distributed generation by three degrees of freedom (3DoF) approach | |
| Lodh et al. | Single stage multi-port Flyback type solar PV module integrated micro-inverter with battery backup | |
| CN108199603B (en) | Multi-winding time-sharing power supply isolation flyback direct current chopper type single-stage multi-input inverter | |
| Sun et al. | A nonisolated bidirectional soft-switching power-unit-based DC–DC converter with unipolar and bipolar structure for DC networks interconnection | |
| Chen et al. | A buck type multi-input distributed generation system with parallel-timesharing power supply | |
| CN108023497B (en) | Series simultaneous power supply forward cycle conversion type single-stage multi-input high-frequency link inverter | |
| CN108023496B (en) | Series simultaneous selection switch voltage type single-stage multi-input low-frequency link inverter | |
| CN108111044B (en) | Isolation flyback periodic wave type single-stage multi-input inverter with external parallel time-sharing selection switch | |
| CN108092538A (en) | Parallel Time-sharing is for being electrically isolated flyback DC chopped-wave type single-stage multi input inverter | |
| CN108199602B (en) | Multi-winding time-sharing power supply forward direct current chopper type single-stage multi-input high-frequency chain inverter | |
| CN116470783A (en) | Time-sharing power supply type single-stage low-frequency chain new energy multi-port integrated power supply system | |
| CN108054946B (en) | Voltage type single-stage multi-input low-frequency link inverter with built-in parallel time-sharing selection switch | |
| CN108092540B (en) | Series simultaneous power supply isolation flyback direct current chopper type single-stage multi-input inverter | |
| CN108206645A (en) | Band energy storage device is powered flyback DC converting type quasi-single-stage multi input inverter simultaneously | |
| CN108199599B (en) | External parallel time-sharing selection switch voltage type single-stage multi-input high-frequency link inverter | |
| Barbosa et al. | Single-stage single-phase AC/DC converter with high frequency isolation feasible to microgeneration | |
| CN108206646B (en) | Voltage type single-stage multi-input non-isolated inverter with built-in parallel time-sharing selection switch | |
| CN108199604A (en) | Series connection is simultaneously for being electrically isolated flyback cycle changing type single-stage multi input inverter | |
| CN108155824A (en) | The series connection non-isolated inverter of simultaneous selection switching voltage type single-stage multi input | |
| CN108023495A (en) | The non-isolated inverter of external Parallel Time-sharing selecting switch voltage-type single-stage multi input |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |