CN103036397B

CN103036397B - Single-level single-phase large-step-up-ratio cascade connection voltage type convertor of quasi impedance source

Info

Publication number: CN103036397B
Application number: CN201210505251.6A
Authority: CN
Inventors: 陈道炼; 黄瑞哲
Original assignee: Fuzhou University
Current assignee: Fuzhou University
Priority date: 2012-11-30
Filing date: 2012-11-30
Publication date: 2014-12-10
Anticipated expiration: 2032-11-30
Also published as: CN103036397A

Abstract

The invention provides a circuit structure of a single-level single-phase large-step-up-ratio cascade connection voltage type convertor of a quasi impedance source. The circuit structure of the single-level single-phase large-step-up-ratio cascade connection voltage type convertor of the quasi impedance source is composed of an input direct-current power source or a single-phase alternating current power source, a large-step-up-ratio impedance network, a high frequency combination modulation switch, a filter, a single-phase alternating current load or a direct-current load, wherein the input direct-current power source or the single-phase alternating current power source, the large-step-up-ratio impedance network, the high frequency combination modulation switch, the filter, the single-phase alternating current load or the direct-current load are connected in a cascading mode in sequence. The large-step-up-ratio impedance network is formed by series connection of an energy storage inductor and n SLCC type two-port impedance network units, wherein the n SLCC type two-port impedance network units are the same and are connected in a cascading mode in sequence. The n is a natural number larger than one. Each SLCC type two-port impedance network unit is composed of a power diode or a four-quadrant power switch, an energy storage inductor and two energy storage capacitors. The high frequency combination modulation switch is composed of a two-quadrant power switch or a four-quadrant power switch. The convertor can effectively convert an unstable low-voltage direct current with a wide changing ranged or a single-phase alternating current into a stable and high-quality single-phase sinusoidal alternating current or direct current in a single-level mode and can be applied to occasions of electrical energy conversion with medium and small capacity.

Description

The accurate source of resistance converter of the large step-up ratio cascade voltage of single-stage and-phase type

Technical field

The accurate source of resistance converter of the large step-up ratio cascade voltage of a kind of single-stage and-phase type involved in the present invention, belongs to power electronic technology.

Background technology

Converter is that applied power semiconductor device is transformed into alternating current or galvanic a kind of static ac dc converter device by direct current or alternating current, for AC load (comprise with AC network and generating electricity by way of merging two or more grid systems) or DC load.

Because the fossil energies such as oil, coal and natural gas (non-renewable energy resources) growing tension, environmental pollution are serious, global warming, nuclear energy produce and can produce the reasons such as nuke rubbish and contaminated environment, the energy and environment have become the significant problem that the 21 century mankind face.The regenerative resources (green energy resource) such as solar energy, wind energy, Hydrogen Energy, tidal energy and geothermal energy, there is cleanliness without any pollution, cheapness, the advantage such as reliable, abundant, its development and utilization is more and more subject to people's attention, and this sustainable development to countries in the world economy has considerable meaning.The direct current energy of the renewable energy conversion such as solar energy, Hydrogen Energy, tidal energy, geothermal energy is normally unsettled, need to adopt DC-AC converter or DC-DC converter to be transformed into AC energy or direct current energy supply load use (comprise with AC network and generating electricity by way of merging two or more grid systems); The AC energy of the renewable energy conversion such as wind energy is the alternating current of variable voltage variable frequency normally, need to adopt AC-DC converter to be transformed into direct current energy for load (as inverter load); The unstable alternating current that the primary power sources such as alternating current generator produce, need to adopt AC-AC converter to be transformed into the AC energy supply AC load use of constant voltage frequently.Take the conversion occasion that DC generator, storage battery, solar cell, fuel cell, wind energy conversion system, alternating current generator etc. are main direct current, main AC power, inverter, DC converter, rectifier and AC converter are with a wide range of applications.

At present, Small And Medium Capacity DC-AC conversion occasion adopts traditional Single-phase Voltage PWM Inverter circuit structure conventionally.This class inverter must meet the peak value that DC voltage is greater than AC phase voltage while normally working, therefore there is an obvious defect: when DC voltage (as photovoltaic cell fan-out capability) reduces, as overcast and rainy or night, whole electricity generation system will be difficult to normal operation, and the utilance of system declines.To this, often adopt following two kinds of methods to solve: (1) prime adds Boost type DC converter or high-frequency isolation type DC-DC converter, has increased power conversion progression, circuit complexity, loss and cost; (2) output adds single phase industrial frequence transformer, has greatly increased volume, weight and the cost of system, is difficult to adapt to today that the copper iron prices of raw and semifnished materials are risen sharply.

At present, Small And Medium Capacity DC-DC, AC-DC, AC-AC conversion occasion is also to adopt traditional pwm converter circuit structure conventionally, exists equally brachium pontis power device that dead band need be set or overlapping time, reliability and output waveform quality are low, step-up ratio large and cost the is high defects such as (input or output and add single phase industrial frequence transformer) of the volume weight of large (non-isolation type), system not.

Therefore, seeking a kind of brachium pontis, need not to establish the accurate source of resistance converter of the large step-up ratio cascade voltage of New single-phase type of Dead Time, high reliability, single-level circuit structure extremely urgent.This must establish Dead Time, step-up ratio large and cost the is high defects such as (input or output and add single phase industrial frequence transformer) of the volume weight of large (non-isolation type), system not for effectively overcoming brachium pontis that conventional P WM converter exists, improve output waveform quality, reliability and the reduction input side EMI of transformation system, widen power electronics converter technique and renewable energy power generation technical know-how, promote the development of generation of electricity by new energy industry and develop energy-savingly all to have great importance with conservation-minded society.

Summary of the invention

The present invention seeks to provide a kind of and there is large step-up ratio, single-stage power conversion, power density is high, conversion efficiency is high, output waveform quality is high, reliability is high, change range of input voltage is wide, cost is low, be applicable to the accurate source of resistance converter of the large step-up ratio cascade voltage of single-stage and-phase type of the features such as Small And Medium Capacity conversion occasion.

Technical scheme 1 of the present invention is: the accurate source of resistance converter of the large step-up ratio cascade voltage of a kind of single-stage and-phase type, is characterized in that: this converter circuit structure is to consist of input DC power, large step-up ratio impedance network, single-phase high frequency hybrid modulation switch, single phase filter and sequentially cascade of single phase alternating current (A.C.) load; Described large step-up ratio impedance network is by energy storage inductor L ₀the n of sequentially cascade identical SLCC type two port Impedance network element are in series, and wherein n is greater than 1 natural number; Each SLCC type two port Impedance network element is by a power diode S _j, an energy storage inductor L _j, two storage capacitor C _jand C _j' form power diode S _jnegative electrode and energy storage inductor L _jone end, storage capacitor C _jpositive ends be connected, energy storage inductor L _jthe other end, power diode S _janode respectively with storage capacitor C _j' positive and negative polarity end be connected, storage capacitor C _jnegative polarity end and the negative polarity end of input DC power connect into common port, power diode S _jwith storage capacitor C _j' link and storage capacitor C _jcommon port formed the input port of j SLCC type two port Impedance network element, energy storage inductor L _jwith storage capacitor C _j' link and storage capacitor C _jcommon port formed the output port of j SLCC type two port Impedance network element, power diode S _jwith storage capacitor C ₁' link and input DC power positive ends between be in series with energy storage inductor L ₀, wherein j is the natural number that is not more than n; Described single-phase high frequency hybrid modulation switch is to consist of four two quadrant power switchs that bear unidirectional voltage stress and bidirectional current stress; By regulating the exponent number n of SLCC type two port Impedance network element and the duty ratio D that magnetizes of converter energy storage inductor ₀=T ₀/ T _srealize the adjusting of converter boost ratio, wherein T _sfor HF switch cycle, T ₀for single-phase high frequency hybrid modulation switch is at a T _sthe interior bridge arm direct pass time; Each energy storage inductor of the accurate source of resistance converter of the large step-up ratio cascade voltage of described single-stage and-phase type is a HF switch cycle T _sinside magnetize and dispel magnetic each once, D during corresponding bridge arm direct pass during magnetizing ₀t _s, and during the magnetic of dispelling corresponding brachium pontis non-straight-through during (1-D ₀) T _sincluded to during two zero vectors outer during AC output energy, bridge arm direct pass, comprise D during bridge arm direct pass ₀t _smagnetize and brachium pontis non-straight-through during (1-D ₀) T _sand the five kinds of operation modes of magnetic of dispelling when lower brachium pontis conducting, output voltage negative half period, the positive half cycle of output voltage and upper brachium pontis conducting, the voltage transmission ratio of the accurate source of resistance converter of the large step-up ratio cascade voltage of described single-stage and-phase type is , wherein M is the index of modulation of single-phase high frequency hybrid modulation switch, at different n, M and D ₀during value, voltage transmission is less than, is equal to and greater than 1 three kinds of situations than existing, as M > 1-(n+1) D ₀time, for example get n=2 and M > 1-3D ₀, voltage transmission ratio is greater than 1, can improve by increasing n value the step-up ratio of converter; The accurate source of resistance converter using of the large step-up ratio cascade voltage of described single-stage and-phase type has output voltage or the grid-connected current instantaneous values feedback Unipolar SPWM control strategy of large step-up ratio impedance network storage capacitor voltage feedforward control, output voltage or grid-connected current instantaneous values feedback Unipolar SPWM control strategy are used for regulating index of modulation M, and large step-up ratio impedance network storage capacitor voltage U _cnfeed-forward Control Strategy is used for regulating straight-through duty ratio D ₀.

Technical scheme 2 of the present invention is: the accurate source of resistance converter of the large step-up ratio cascade voltage of a kind of single-stage and-phase type, is characterized in that: this converter circuit structure is to consist of input DC power, large step-up ratio impedance network, high frequency hybrid modulation switch, filter and sequentially cascade of DC load; Described large step-up ratio impedance network is by energy storage inductor L ₀the n of sequentially cascade identical SLCC type two port Impedance network element are in series, and wherein n is greater than 1 natural number; Each SLCC type two port Impedance network element is by a power diode S _j, an energy storage inductor L _j, two storage capacitor C _jand C _j' form power diode S _jnegative electrode and energy storage inductor L _jone end, storage capacitor C _jpositive ends be connected, energy storage inductor L _jthe other end, power diode S _janode respectively with storage capacitor C _j' positive and negative polarity end be connected, storage capacitor C _jnegative polarity end and the negative polarity end of input DC power connect into common port, power diode S _jwith storage capacitor C _j' link and storage capacitor C _jcommon port formed the input port of j SLCC type two port Impedance network element, energy storage inductor L _jwith storage capacitor C _j' link and storage capacitor C _jcommon port formed the output port of j SLCC type two port Impedance network element, power diode S _jwith storage capacitor C ₁' link and input DC power positive ends between be in series with energy storage inductor L ₀, wherein j is the natural number that is not more than n; Described high frequency hybrid modulation switch is to consist of two quadrant power switchs that bear unidirectional voltage stress and bidirectional current stress; By regulating the exponent number n of SLCC type two port Impedance network element and the duty ratio D that magnetizes of converter energy storage inductor ₀=T ₀/ T _srealize the adjusting of converter boost ratio, wherein T _sfor HF switch cycle, T ₀for high frequency hybrid modulation switch is at a T _sinterior ON time; Each energy storage inductor of the accurate source of resistance converter of the large step-up ratio cascade voltage of described single-stage and-phase type is a HF switch cycle T _sinside magnetize and dispel magnetic each once, D during corresponding high frequency hybrid modulation switch conduction during magnetizing ₀t _s, and corresponding high frequency hybrid modulation switch (1-D between the off period during the magnetic of dispelling ₀) T _s, comprise conduction period D ₀t _smagnetize and (1-D between the off period ₀) T _sthe two kinds of operation modes of magnetic of dispelling; The voltage transmission ratio of the accurate source of resistance converter of the large step-up ratio cascade voltage of described single-stage and-phase type is , different n, D ₀during value, voltage transmission is greater than 1 than all, and is greater than the voltage transmission ratio of traditional single stage PWM DC-DC converter, can improve by increasing n value the step-up ratio of converter.

Technical scheme 3 of the present invention is: the accurate source of resistance converter of the large step-up ratio cascade voltage of a kind of single-stage and-phase type, is characterized in that: this converter circuit structure is to consist of input single-phase AC power, large step-up ratio impedance network, single-phase high frequency hybrid modulation switch, filter and sequentially cascade of DC load; Described large step-up ratio impedance network is by energy storage inductor L ₀the n of sequentially cascade identical SLCC type two port Impedance network element are in series, and wherein n is greater than 1 natural number; Each SLCC type two port Impedance network element is by a four-quadrant power switch S _j, an energy storage inductor L _j, two storage capacitor C _jand C _j' form four-quadrant power switch S _jone end and energy storage inductor L _jone end, storage capacitor C _jone end be connected, four-quadrant power switch S _jthe other end, energy storage inductor L _jthe other end respectively with storage capacitor C _j' two ends be connected, storage capacitor C _jthe other end and the reference negative polarity end of input single-phase AC power connect into common port, four-quadrant power switch S _jwith storage capacitor C _j' link and storage capacitor C _jcommon port formed the input port of j SLCC type two port Impedance network element, energy storage inductor L _jwith storage capacitor C _j' link and storage capacitor C _jcommon port formed the output port of j SLCC type two port Impedance network element, four-quadrant power switch S _jwith storage capacitor C ₁' link and the reference positive ends of input single-phase AC power between be in series with energy storage inductor L ₀, wherein j is the natural number that is not more than n; Described single-phase high frequency hybrid modulation switch is to consist of four two quadrant power switchs that bear unidirectional voltage stress and bidirectional current stress; By regulating the exponent number n of SLCC type two port Impedance network element and the duty ratio D that magnetizes of converter energy storage inductor ₀=T ₀/ T _srealize the adjusting of converter boost ratio, wherein T _sfor HF switch cycle, T ₀for single-phase high frequency hybrid modulation switch is at a T _sinterior ON time; Each energy storage inductor of the accurate source of resistance converter of the large step-up ratio cascade voltage of described single-stage and-phase type is a HF switch cycle T _srespectively once, during magnetizing, correspondence is descended brachium pontis conduction period D to the magnetic that inside magnetizes and dispel ₀t _s, and (1-D during corresponding brachium pontis cross-conduction during the magnetic of dispelling ₀) T _s, brachium pontis conduction period D under energy storage inductor while comprising the positive and negative half cycle of input voltage ₀t _smagnetize, (1-D during brachium pontis cross-conduction ₀) T _sthe four kinds of operation modes of magnetic of dispelling; The voltage transmission ratio of the accurate source of resistance converter of the large step-up ratio cascade voltage of described single-stage and-phase type is , different n, D ₀during value, voltage transmission is greater than 1 than all, and is greater than the voltage transmission ratio of traditional single stage PWM A.C.-D.C. converter, can improve by increasing n value the step-up ratio of converter.

Technical scheme 4 of the present invention is: the accurate source of resistance converter of the large step-up ratio cascade voltage of a kind of single-stage and-phase type, is characterized in that: this converter circuit structure is to consist of input single-phase AC power, large step-up ratio impedance network, single-phase high frequency hybrid modulation switch, single phase filter and sequentially cascade of single phase alternating current (A.C.) load; Described large step-up ratio impedance network is by energy storage inductor L ₀the n of sequentially cascade identical SLCC type two port Impedance network element are in series, and wherein n is greater than 1 natural number; Each SLCC type two port Impedance network element is by a four-quadrant power switch S _j, an energy storage inductor L _j, two storage capacitor C _jand C _j' form four-quadrant power switch S _jone end and energy storage inductor L _jone end, storage capacitor C _jone end be connected, four-quadrant power switch S _jthe other end, energy storage inductor L _jthe other end respectively with storage capacitor C _j' two ends be connected, storage capacitor C _jthe other end and the reference negative polarity end of input single-phase AC power connect into common port, four-quadrant power switch S _jwith storage capacitor C _j' link and storage capacitor C _jcommon port formed the input port of j SLCC type two port Impedance network element, energy storage inductor L _jwith storage capacitor C _j' link and storage capacitor C _jcommon port formed the output port of j SLCC type two port Impedance network element, four-quadrant power switch S _jwith storage capacitor C ₁' link and the reference positive ends of input single-phase AC power between be in series with energy storage inductor L ₀, wherein j is the natural number that is not more than n; Described single-phase high frequency hybrid modulation switch is to consist of a four-quadrant power switch that bears bi-directional voltage stress and bidirectional current stress; By regulating the exponent number n of SLCC type two port Impedance network element and the duty ratio D that magnetizes of converter energy storage inductor ₀=T ₀/ T _srealize the adjusting of converter boost ratio, wherein T _sfor HF switch cycle, T ₀for single-phase high frequency hybrid modulation switch is at a T _sinterior ON time; Each energy storage inductor of the accurate source of resistance converter of the large step-up ratio cascade voltage of described single-stage and-phase type is a HF switch cycle T _sinside magnetize and dispel magnetic each once, D during corresponding single-phase high frequency hybrid modulation switch conduction during magnetizing ₀t _s, and corresponding single-phase high frequency hybrid modulation switch (1-D between the off period during the magnetic of dispelling ₀) T _s, energy storage inductor D during single-phase high frequency hybrid modulation switch conduction while comprising the positive and negative half cycle of input voltage ₀t _smagnetize and (1-D between the off period ₀) T _sthe four kinds of operation modes of magnetic of dispelling; The voltage transmission ratio of the accurate source of resistance parallel operation of the large step-up ratio cascade voltage of described single-stage and-phase type is , different n, D ₀during value, voltage transmission is greater than 1 than all, and is greater than the voltage transmission ratio of traditional single stage PWM ac-to-ac converter, can improve by increasing n value the step-up ratio of converter.

The invention has the advantages that: the present invention can be transformed into single-phase sinusoidal ac or direct current stable, high-quality by unsettled wide excursion low-voltage DC or single-phase alternating current single-stage, there is single-stage power conversion, power density is high, conversion efficiency is high, step-up ratio is large, output waveform quality is high, reliability is high, low cost and other advantages, is applicable to Small And Medium Capacity DC-AC, DC-DC, AC-DC and AC-AC transformation of electrical energy occasion.

Accompanying drawing explanation

Fig. 1. the circuit structure of the accurate source of resistance direct-current-alternating-current converter of the large step-up ratio cascade voltage of single-stage and-phase type.

Fig. 2. the principle waveform of the accurate source of resistance direct-current-alternating-current converter of the large step-up ratio cascade voltage of single-stage and-phase type.

Fig. 3. the circuit topology example of the accurate source of resistance direct-current-alternating-current converter of the large step-up ratio cascade voltage of single-stage and-phase type.

Fig. 4. the large step-up ratio cascade voltage of single-stage and-phase type accurate source of resistance direct-current-alternating-current converter energy storage inductor D during bridge arm direct pass ₀t _sthe equivalent electric circuit that magnetizes.

Fig. 5. the accurate source of resistance direct-current-alternating-current converter of the large step-up ratio cascade voltage of single-stage and-phase type energy storage inductor brachium pontis non-straight-through during (1-D ₀) T _sand the magnetic equivalent electric circuit of dispelling during lower brachium pontis conducting.

Fig. 6. the accurate source of resistance direct-current-alternating-current converter of the large step-up ratio cascade voltage of single-stage and-phase type energy storage inductor brachium pontis non-straight-through during (1-D ₀) T _sand the magnetic equivalent electric circuit of dispelling during output voltage negative half period.

Fig. 7. the accurate source of resistance direct-current-alternating-current converter of the large step-up ratio cascade voltage of single-stage and-phase type energy storage inductor brachium pontis non-straight-through during (1-D ₀) T _sand the magnetic equivalent electric circuit of dispelling during the positive half cycle of output voltage.

Fig. 8. the accurate source of resistance direct-current-alternating-current converter of the large step-up ratio cascade voltage of single-stage and-phase type energy storage inductor brachium pontis non-straight-through during (1-D ₀) T _sand the magnetic equivalent electric circuit of dispelling during upper brachium pontis conducting.

Fig. 9. the control principle block diagram of the accurate source of resistance direct-current-alternating-current converter of the large step-up ratio cascade voltage of single-stage and-phase type.

Figure 10. the control principle waveform of the accurate source of resistance direct-current-alternating-current converter of the large step-up ratio cascade voltage of single-stage and-phase type.

Figure 11. the circuit structure of the accurate source of resistance DC-DC converter of the large step-up ratio cascade voltage of single-stage and-phase type.

Figure 12. the principle waveform of the accurate source of resistance DC-DC converter of the large step-up ratio cascade voltage of single-stage and-phase type.

Figure 13. the circuit topology example of the accurate source of resistance DC-DC converter of the large step-up ratio cascade voltage of single-stage and-phase type.

Figure 14. the accurate source of resistance DC-DC converter of the large step-up ratio cascade voltage of single-stage and-phase type energy storage inductor D during high frequency hybrid modulation switch conduction ₀t _sthe equivalent electric circuit that magnetizes.

Figure 15. the accurate source of resistance DC-DC converter of the large step-up ratio cascade voltage of single-stage and-phase type energy storage inductor is at high frequency hybrid modulation switch (1-D between the off period ₀) T _sthe magnetic equivalent electric circuit of dispelling.

Figure 16. the control principle block diagram of the accurate source of resistance DC-DC converter of the large step-up ratio cascade voltage of single-stage and-phase type.

Figure 17. the control principle waveform of the accurate source of resistance DC-DC converter of the large step-up ratio cascade voltage of single-stage and-phase type.

Figure 18. the circuit structure of the accurate source of resistance A.C.-D.C. converter of the large step-up ratio cascade voltage of single-stage and-phase type.

Figure 19. the principle waveform of the accurate source of resistance A.C.-D.C. converter of the large step-up ratio cascade voltage of single-stage and-phase type.

Figure 20. the circuit topology example of the accurate source of resistance A.C.-D.C. converter of the large step-up ratio cascade voltage of single-stage and-phase type.

Figure 21. the accurate source of resistance A.C.-D.C. converter of the large step-up ratio cascade voltage of single-stage and-phase type energy storage inductor is at lower brachium pontis conduction period D ₀t _sand the equivalent electric circuit that magnetizes during the positive half cycle of input voltage.

Figure 22. the accurate source of resistance A.C.-D.C. converter of the large step-up ratio cascade voltage of single-stage and-phase type energy storage inductor (1-D during brachium pontis cross-conduction ₀) T _sand the magnetic equivalent electric circuit of dispelling during the positive half cycle of input voltage.

Figure 23. the accurate source of resistance A.C.-D.C. converter of the large step-up ratio cascade voltage of single-stage and-phase type energy storage inductor is at lower brachium pontis conduction period D ₀t _sand the equivalent electric circuit that magnetizes during input voltage negative half period.

Figure 24. the accurate source of resistance A.C.-D.C. converter of the large step-up ratio cascade voltage of single-stage and-phase type energy storage inductor (1-D during brachium pontis cross-conduction ₀) T _sand the magnetic equivalent electric circuit of dispelling during input voltage negative half period.

Figure 25. the control principle block diagram of the accurate source of resistance A.C.-D.C. converter of the large step-up ratio cascade voltage of single-stage and-phase type.

Figure 26. the control principle waveform of the accurate source of resistance A.C.-D.C. converter of the large step-up ratio cascade voltage of single-stage and-phase type.

Figure 27. the circuit structure of the accurate source of resistance ac-to-ac converter of the large step-up ratio cascade voltage of single-stage and-phase type.

Figure 28. the principle waveform of the accurate source of resistance ac-to-ac converter of the large step-up ratio cascade voltage of single-stage and-phase type.

Figure 29. the circuit topology example of the accurate source of resistance ac-to-ac converter of the large step-up ratio cascade voltage of single-stage and-phase type.

Figure 30. the accurate source of resistance ac-to-ac converter of the large step-up ratio cascade voltage of single-stage and-phase type energy storage inductor D during high frequency hybrid modulation switch conduction ₀t _sand the equivalent electric circuit that magnetizes during the positive half cycle of input voltage.

Figure 31. the accurate source of resistance ac-to-ac converter of the large step-up ratio cascade voltage of single-stage and-phase type energy storage inductor is at high frequency hybrid modulation switch (1-D between the off period ₀) T _sand the magnetic equivalent electric circuit of dispelling during the positive half cycle of input voltage.

Figure 32. the accurate source of resistance ac-to-ac converter of the large step-up ratio cascade voltage of single-stage and-phase type energy storage inductor D during high frequency hybrid modulation switch conduction ₀t _sand the equivalent electric circuit that magnetizes during input voltage negative half period.

Figure 33. the accurate source of resistance ac-to-ac converter of the large step-up ratio cascade voltage of single-stage and-phase type energy storage inductor is at high frequency hybrid modulation switch (1-D between the off period ₀) T _sand the magnetic equivalent electric circuit of dispelling during input voltage negative half period.

Figure 34. the control principle block diagram of the accurate source of resistance ac-to-ac converter of the large step-up ratio cascade voltage of single-stage and-phase type.

Figure 35. the control principle waveform of the accurate source of resistance ac-to-ac converter of the large step-up ratio cascade voltage of single-stage and-phase type.

Embodiment

Below in conjunction with drawings and Examples, technical scheme 1 of the present invention is described further.

The accurate source of resistance direct-current-alternating-current converter of the large step-up ratio cascade voltage of single-stage and-phase type is to consist of input DC power, large step-up ratio impedance network, single-phase high frequency hybrid modulation switch, single phase filter and sequentially cascade of single phase alternating current (A.C.) load; Described large step-up ratio impedance network is by energy storage inductor L ₀the n of sequentially cascade identical SLCC type two port Impedance network element are in series, and wherein n is greater than 1 natural number; Each SLCC type two port Impedance network element is by a power diode S _j, an energy storage inductor L _j, two storage capacitor C _jand C _j' form power diode S _jnegative electrode and energy storage inductor L _jone end, storage capacitor C _jpositive ends be connected, energy storage inductor L _jthe other end, power diode S _janode respectively with storage capacitor C _j' positive and negative polarity end be connected, storage capacitor C _jnegative polarity end and the negative polarity end of input DC power connect into common port, power diode S _jwith storage capacitor C _j' link and storage capacitor C _jcommon port formed the input port of j SLCC type two port Impedance network element, energy storage inductor L _jwith storage capacitor C _j' link and storage capacitor C _jcommon port formed the output port of j SLCC type two port Impedance network element, power diode S ₁with storage capacitor C ₁' link and input DC power positive ends between be in series with energy storage inductor L ₀, wherein j is the natural number that is not more than n; Described single-phase high frequency hybrid modulation switch is to consist of four two quadrant power switchs that bear unidirectional voltage stress and bidirectional current stress.

The large step-up ratio cascade voltage of single-stage and-phase type accurate source of resistance direct-current-alternating-current converter circuit structure and principle waveform, respectively as shown in Figure 1, 2.In Fig. 1,2, U _ifor input direct voltage, Z _lfor single-phase output AC load (comprising single phase alternating current (A.C.) passive load and the load of single phase alternating current (A.C.) electrical network), u _o, i _obe respectively single-phase output AC voltage and alternating current.Large step-up ratio impedance network is by energy storage inductor L ₀the n of sequentially cascade identical SLCC type two port Impedance network element are in series, and wherein n is greater than 1 natural number, and each SLCC type two port Impedance network element is by a power diode S _j, an energy storage inductor L _j, two storage capacitor C _jand C _j' form; Single-phase high frequency hybrid modulation switch, half-bridge converter is to consist of four two quadrant power switchs that can bear unidirectional voltage stress and bidirectional current stress; Single phase filter is single-phase LC filter (during single phase alternating current (A.C.) passive load) or single-phase LCL filter (during the load of single phase alternating current (A.C.) electrical network); Input DC power U _iand between large step-up ratio impedance network, can arrange or input filter is not set, when input filter is set, can reduce the pulsation of input direct-current electric current.When a bridge arm direct pass of single-phase high frequency hybrid modulation switch (half-bridge converter), input DC power U _iwith all storage capacitors to energy storage inductor L ₀, L ₁... L _nmagnetize, single-phase output AC load relies on single phase filter to maintain power supply; When the conducting of single-phase high frequency hybrid modulation switch (half-bridge converter) brachium pontis switch cross, energy storage inductor L ₀, L ₁... L _nmagnetic and and input DC power U dispel _icommon to all storage capacitors, single phase alternating current (A.C.) load supplying together.Large step-up ratio impedance network and single-phase high frequency hybrid modulation switch (half-bridge converter) are by input direct voltage U _ibe modulated into the high frequency pulse dc voltage u that amplitude changes by twice output frequency sinusoidal envelope wire gauge rule ₁, single-phase high frequency hybrid modulation switch (half-bridge converter) is by u ₁be reverse into the tri-state modulation voltage ripple u that pulsewidth changes by sinusoidal rule ₂, after single-phase filtering, on single phase alternating current (A.C.) passive load, obtain high-quality single-phase sinusoidal voltage u _oor in the load of single phase alternating current (A.C.) electrical network, obtain high-quality single-phase sinusoidal current i _o.

Single-stage and-phase direct-current-alternating-current converter of the present invention, be the single-level circuit structure that the input that utilizes SLCC type two port Impedance network element that the n of sequentially cascade is identical and prime two port Impedance network element to be output as rear class two port Impedance network element improves converter boost ratio, exist difference in essence with single-stage and-phase voltage type PWM direct-current-alternating-current converter or multi-stage cascade PWM direct-current-alternating-current converter circuit structure.Therefore, single-stage and-phase direct-current-alternating-current converter of the present invention has novelty and creativeness, and there is conversion efficiency high (meaning that energy loss is little), power density is high (means volume, weight is little), step-up ratio large (meaning that the input direct voltage that excursion is wider or lower can be transformed into required single-phase output AC voltage or alternating current), the output waveform distortion factor is low, reliability is high, input voltage preparation flexibly, cost is low, the advantages such as application prospect is extensive, it is a kind of desirable energy-saving and cost-reducing type single-phase DC-AC converter, vigorously advocating, construction is energy-saving, have more important value today of conservation-minded society.

The accurate source of resistance direct-current-alternating-current converter of the large step-up ratio cascade voltage of single-stage and-phase type circuit topology embodiment, as shown in Figure 3.What Fig. 3 provided is single-phase LC filter circuit, does not provide as space is limited and is applicable to the single-phase LCL filter circuit higher to output waveform quality requirement; Single-phase high frequency hybrid modulation switch (half-bridge converter) is selected MOSFET device, also can select the devices such as IGBT, GTR.Described direct-current-alternating-current converter can be transformed into a kind of unsettled low-voltage DC (as storage battery, photovoltaic cell, fuel cell, wind energy conversion system etc.) the single-phase sinusoidal ac of required stable, high-quality, high pressure, is widely used in Small And Medium Capacity, the civilian industry Single-Phase Inverter Source of the occasion of boosting is (as communication inverter and photovoltaic combining inverter 24VDC/220V50HzAC, 48VDC/220V50HzAC, 96VDC/

220V50HzAC) and national defense industry inverter (as Aviation Static Inverter 27VDC/115V400HzAC) etc.

Each energy storage inductor of the accurate source of resistance direct-current-alternating-current converter of the large step-up ratio cascade voltage of single-stage and-phase type is a HF switch cycle T _sinside magnetize and dispel magnetic each once, D during corresponding bridge arm direct pass during magnetizing ₀t _s, and during the magnetic of dispelling corresponding brachium pontis non-straight-through during (1-D ₀) T _s(comprising during two zero vectors outer during AC output energy, bridge arm direct pass).Described direct-current-alternating-current converter energy storage inductor D during bridge arm direct pass ₀t _sthe equivalent electric circuit that magnetizes, brachium pontis non-straight-through during (1-D ₀) T _sand the magnetic equivalent electric circuit of dispelling when lower brachium pontis conducting, output voltage negative half period, the positive half cycle of output voltage and upper brachium pontis conducting, respectively as shown in Fig. 4,5,6,7,8.In Fig. 4,5,6,7,8, output voltage u _opolarity be reference direction, and each current polarity is actual direction.

If storage capacitor terminal voltage is a HF switch cycle T _sbe inside invariable, use , represent; Input DC power current i _ienergy storage inductor L namely ₀current i _l0.Energy storage inductor D during bridge arm direct pass as shown in Figure 4 ₀t _sthe equivalent electric circuit that magnetizes can obtain,

（1.0）

（1.1）（1.2）

（1.j）

（1.n）

In formula (1.0)-(1.n), n is greater than 1 natural number, and j is the natural number that is not more than n.By energy storage inductor shown in Fig. 5,6,7,8 brachium pontis non-straight-through during (1-D ₀) T _sand the magnetic equivalent electric circuit of dispelling when lower brachium pontis conducting, output voltage negative half period, the positive half cycle of output voltage and upper brachium pontis conducting can obtain,

(2.0)

(2.1)

(2.2)

(2.j)

(2.n)

If the voltage magnitude of single-phase high frequency hybrid modulation switch (half-bridge converter) DC side is U ₁, can supplement equation

(3.1)

(3.2)

(3.j)

(3.n)

According to State-space Averaging Principle, , order , association type (3), large step-up ratio impedance network storage capacitor magnitude of voltage , for

(4.1)

(4.2)

(4.j)

(4.n)

(5)

The voltage magnitude U of single-phase high frequency hybrid modulation switch (half-bridge converter) DC side ₁for

(6)

In formula (6), (n+1) D ₀< 1, i.e. D ₀< 1/(n+1).If the index of modulation of single-phase high frequency hybrid modulation switch (half-bridge converter) is M(0 < M≤1-D ₀), the voltage transmission ratio of the accurate source of resistance direct-current-alternating-current converter of the large step-up ratio cascade voltage of single-stage and-phase type is

（7）

From formula (7), the voltage transmission of described single-stage and-phase direct-current-alternating-current converter than the voltage transmission that is greater than traditional single stage voltage type PWM direct-current-alternating-current converter than M, and at different n, M and D ₀during value, voltage transmission is less than, is equal to and greater than 1 three kinds of situations than existing.As M > 1-(n+1) D ₀time, for example get n=2 and M > 1-3 D ₀the voltage transmission ratio that can realize described converter is greater than 1, thereby embody the superiority of this converter, particularly can improve the step-up ratio of converter by increasing n value, therefore be called the accurate source of resistance direct-current-alternating-current converter of the large step-up ratio cascade voltage of single-stage and-phase type.

The accurate source of resistance direct-current-alternating-current converter of the large step-up ratio cascade voltage of single-stage and-phase type only has single-stage power conversion link, its control system need to realize the control of storage capacitor voltage and the output voltage (grid-connected current) of large step-up ratio impedance network, also needs the MPPT maximum power point tracking that realizes photovoltaic cell to control MPPT during supplying power for photovoltaic cell.Therefore, this single-stage and-phase direct-current-alternating-current converter adopts output voltage (grid-connected current) the instantaneous values feedback Unipolar SPWM control strategy with large step-up ratio impedance network storage capacitor voltage feedforward control, as shown in Fig. 9,10.Output voltage u _o(grid-connected current i _o) instantaneous values feedback Unipolar SPWM control strategy is used for regulating the modulation ratio M of transformation system, and large step-up ratio impedance network storage capacitor voltage U _cnfeed-forward Control Strategy is used for regulating the straight-through duty ratio D of transformation system ₀.

Output voltage feedback signal u _ofwith reference voltage u _rcomparison, error obtain signal u after amplifying _e(characterizing Sine Modulated than signal M), storage capacitor voltage feedback signal U _cnfwith storage capacitor voltage reference signal U _cnrcomparison, error obtain signal u after amplifying _d(characterize straight-through duty cycle signals D ₀); u _e, u _dand inversion signal respectively with triangular carrier u _chand over and cut and output single-phase high frequency hybrid modulation switch (half-bridge converter) S after suitable logical circuit ₁', S ₃', S ₂', S ₄' control signal.As input voltage U _iduring variation, by regulating straight-through duty cycle signals D ₀realize storage capacitor voltage U _cnstable; As output loading Z _lwhile changing, by regulating Sine Modulated to realize output voltage u than signal M _ostable.Therefore, to adopt output voltage (grid-connected current) the instantaneous values feedback Unipolar SPWM control strategy with large step-up ratio impedance network storage capacitor voltage feedforward control be practicable for described single-stage and-phase direct-current-alternating-current converter.

Below in conjunction with drawings and Examples, technical scheme 2 of the present invention is described further.

The accurate source of resistance DC-DC converter of the large step-up ratio cascade voltage of single-stage and-phase type is to consist of input DC power, large step-up ratio impedance network, high frequency hybrid modulation switch, filter and sequentially cascade of DC load; Described large step-up ratio impedance network is by energy storage inductor L ₀the n of sequentially cascade identical SLCC type two port Impedance network element are in series, and wherein n is greater than 1 natural number; Each SLCC type two port Impedance network element is by a power diode S _j, an energy storage inductor L _j, two storage capacitor C _jand C _j' form power diode S _jnegative electrode and energy storage inductor L _jone end, storage capacitor C _jpositive ends be connected, energy storage inductor L _jthe other end, power diode S _janode respectively with storage capacitor C _j' positive and negative polarity end be connected, storage capacitor C _jnegative polarity end and the negative polarity end of input DC power connect into common port, power diode S _jwith storage capacitor C _j' link and storage capacitor C _jcommon port formed the input port of j SLCC type two port Impedance network element, energy storage inductor L _jwith storage capacitor C _j' link and storage capacitor C _jcommon port formed the output port of j SLCC type two port Impedance network element, power diode S ₁with storage capacitor C ₁' link and input DC power positive ends between be in series with energy storage inductor L ₀, wherein j is the natural number that is not more than n; Described high frequency hybrid modulation switch is to consist of two quadrant power switchs that bear unidirectional voltage stress and bidirectional current stress.

The large step-up ratio cascade voltage of single-stage and-phase type accurate source of resistance DC-DC converter circuit structure and principle waveform, respectively as shown in Figure 11,12.In Figure 11,12, U _ifor input direct voltage, Z _lfor output DC load, U _o, I _obe respectively output dc voltage and direct current.Large step-up ratio impedance network is by energy storage inductor L ₀the n of sequentially cascade identical SLCC type two port Impedance network element are in series, and wherein n is greater than 1 natural number, and each SLCC type two port Impedance network element is by a power diode S _j, an energy storage inductor L _j, two storage capacitor C _jand C _j' form; High frequency hybrid modulation switch is to consist of the two quadrant power switchs that can bear unidirectional voltage stress and bidirectional current stress; Output filter is LC filter; Input DC power U _iand between large step-up ratio impedance network, can arrange or input filter is not set, when input filter is set, can reduce the pulsation of input direct-current electric current.When high frequency hybrid modulation switch conduction, input DC power U _iwith all storage capacitors to energy storage inductor L ₀, L ₁... L _nmagnetize, output DC load relies on output filter to maintain power supply; When high frequency hybrid modulation switch ends, energy storage inductor L ₀, L ₁... L _nmagnetic and and input DC power U dispel _itogether jointly to all storage capacitors, the power supply of output DC load.Large step-up ratio impedance network and high frequency hybrid modulation switch are by input direct voltage U _ibe modulated into high frequency pulse dc voltage u ₁and u ₂, after filtering, in output DC load, obtain level and smooth direct voltage U _o.

Single-stage DC-DC converter of the present invention, be the single-level circuit structure that the input that utilizes SLCC type two port Impedance network element that the n of sequentially cascade is identical and prime two port Impedance network element to be output as rear class two port Impedance network element improves converter boost ratio, exist difference in essence with traditional single-stage PWM DC-DC converter circuit structure.Therefore, single-stage DC-DC converter of the present invention has novelty and creativeness, and there is conversion efficiency high (meaning that energy loss is little), power density is high (means volume, weight is little), step-up ratio large (meaning that the input direct voltage that excursion is wider or lower can be transformed into needed output dc voltage), output voltage ripple is little, reliability is high, input voltage preparation flexibly, cost is low, the advantages such as application prospect is extensive, it is a kind of desirable energy-saving and cost-reducing type DC-DC converter, vigorously advocating, construction is energy-saving, have more important value today of conservation-minded society.

The accurate source of resistance DC-DC converter of the large step-up ratio cascade voltage of single-stage and-phase type circuit topology embodiment, as shown in figure 13.In Figure 13, what output filter was selected is LC filter circuit; High frequency hybrid modulation switch S ₁ ^'select MOSFET device, also can select the devices such as IGBT, GTR.Described single-stage DC-DC converter can be transformed into a kind of unsettled low-voltage DC (as storage battery, photovoltaic cell, fuel cell, wind energy conversion system etc.) high voltage direct current of required stable, high-quality, is widely used in Small And Medium Capacity, the civilian industry DC power supply of the occasion of boosting (as communication DC converter and photovoltaic DC converter 24VDC/220VDC, 48VDC/380VDC, 96VDC/380VDC) and national defense industry DC power supply (as aviation DC converter 27VDC/270VDC) etc.

Each energy storage inductor of the accurate source of resistance DC-DC converter of the large step-up ratio cascade voltage of single-stage and-phase type is a HF switch cycle T _sinside magnetize and dispel magnetic each once, corresponding high frequency hybrid modulation switch S during magnetizing ₁ ^'conduction period D ₀t _s, and corresponding high frequency hybrid modulation switch S during the magnetic of dispelling ₁ ^'(1-D between the off period ₀) T _s(to during outlet side output energy).Described DC-DC converter energy storage inductor is in high frequency hybrid modulation switch S ₁ ^'conduction period D ₀t _smagnetize equivalent electric circuit and (1-D between the off period ₀) T _sthe magnetic equivalent electric circuit of dispelling, respectively as shown in Figure 14,15.

If storage capacitor terminal voltage is a HF switch cycle T _sbe inside invariable, use , represent; Input DC power current i _ienergy storage inductor L namely ₀current i _l0.Energy storage inductor is in high frequency hybrid modulation switch S as shown in Figure 14 ₁ ^'conduction period D ₀t _sthe equivalent electric circuit that magnetizes can obtain formula (1.0)-(1.n); Energy storage inductor is in high frequency hybrid modulation switch S as shown in Figure 15 ₁ ^'(1-D between the off period ₀) T _sthe magnetic equivalent electric circuit of dispelling can obtain formula (2.0)-(2.n); If high frequency hybrid modulation switch S ₁ ^'(1-D between the off period ₀) T _svoltage magnitude be U ₁(U ₂), can obtain supplementary equation (3.1)-(3.n); According to State-space Averaging Principle, , order , association type (3), large step-up ratio impedance network storage capacitor magnitude of voltage , by formula (4.1)-(4.n) and formula (5), represented; High frequency hybrid modulation switch S ₁ ^'(1-D between the off period ₀) T _svoltage magnitude U ₁(U ₂) by formula (6), represented.During according to output inductor stable state weber equilibrium principle, can obtain

（8）

（9）

Therefore, the voltage transmission ratio of the accurate source of resistance DC-DC converter of the large step-up ratio cascade voltage of single-stage and-phase type is

（10）

From formula (10), the voltage transmission of described single-stage DC-DC converter ratio is at different n, D ₀during value, be all greater than 1, and the voltage transmission that is greater than traditional single stage PWM DC-DC converter compares D ₀(Buck type), 1/(1-D ₀) (Boost type), D ₀/ (1-D ₀) (Buck-Boost type).Particularly, can improve the step-up ratio of converter by increasing n value, therefore be called the accurate source of resistance DC-DC converter of the large step-up ratio cascade voltage of single-stage and-phase type.

The accurate source of resistance DC-DC converter of the large step-up ratio cascade voltage of single-stage and-phase type only has single-stage power conversion link, its control system need to realize the control of output voltage, also needs the MPPT maximum power point tracking that realizes photovoltaic cell to control MPPT during supplying power for photovoltaic cell.Therefore, this single-stage DC-DC converter adopts the PWM control strategy of output voltage feedback, as shown in Figure 16,17.Output voltage feedback signal U _ofwith reference voltage U _rcomparison, error obtain signal U after amplifying _e, U _ewith triangular carrier u _chand over and cut rear output high frequency hybrid modulation switch S ₁' control signal.As input voltage U _ior load Z _lduring variation, by regulating conducting duty ratio D ₀realize output voltage U _ostable.Therefore the PWM control strategy that, described single-stage DC-DC converter adopts output voltage to feed back is practicable.

Below in conjunction with drawings and Examples, technical scheme 3 of the present invention is described further.

The accurate source of resistance A.C.-D.C. converter of the large step-up ratio cascade voltage of single-stage and-phase type is to consist of input single-phase AC power, large step-up ratio impedance network, single-phase high frequency hybrid modulation switch, filter and sequentially cascade of DC load; Described large step-up ratio impedance network is by energy storage inductor L ₀the n of sequentially cascade identical SLCC type two port Impedance network element are in series, and wherein n is greater than 1 natural number; Each SLCC type two port Impedance network element is by a four-quadrant power switch S _j, an energy storage inductor L _j, two storage capacitor C _jand C _j' form four-quadrant power switch S _jone end and energy storage inductor L _jone end, storage capacitor C _jone end be connected, four-quadrant power switch S _jthe other end, energy storage inductor L _jthe other end respectively with storage capacitor C _j' two ends be connected, storage capacitor C _jthe other end and the reference negative polarity end of input single-phase AC power connect into common port, four-quadrant power switch S _jwith storage capacitor C _j' link and storage capacitor C _jcommon port formed the input port of j SLCC type two port Impedance network element, energy storage inductor L _jwith storage capacitor C _j' link and storage capacitor C _jcommon port formed the output port of j SLCC type two port Impedance network element, four-quadrant power switch S ₁with storage capacitor C ₁' link and the reference positive ends of input single-phase AC power between be in series with energy storage inductor L ₀, wherein j is the natural number that is not more than n; Described single-phase high frequency hybrid modulation switch is to consist of four two quadrant power switchs that bear unidirectional voltage stress and bidirectional current stress.

The large step-up ratio cascade voltage of single-stage and-phase type accurate source of resistance A.C.-D.C. converter circuit structure and principle waveform, respectively as shown in Figure 18,19.In Figure 18,19, u _ifor input single-phase alternating voltage, Z _lfor output DC load, U _o, I _obe respectively output dc voltage and direct current.Large step-up ratio impedance network is by energy storage inductor L ₀the n of sequentially cascade identical SLCC type two port Impedance network element are in series, and wherein n is greater than 1 natural number, and each SLCC type two port Impedance network element is by a four-quadrant power switch S _j, an energy storage inductor L _j, two storage capacitor C _jand C _j' form; Single-phase high frequency hybrid modulation switch, single-phase rectification bridge is to consist of four two quadrant power switchs that can bear unidirectional voltage stress and bidirectional current stress; Output filter is LC filter; Input ac power u _iand between large step-up ratio impedance network, can arrange or input filter is not set, when input filter is set, can reduce the harmonic content of input AC electric current.When the lower brachium pontis conducting of single-phase high frequency hybrid modulation switch (single-phase rectification bridge), input ac power u _iwith all storage capacitors to energy storage inductor L ₀, L ₁... L _nmagnetize, output DC load relies on filter to maintain power supply; When the conducting of single-phase high frequency hybrid modulation switch (single-phase rectification bridge) brachium pontis switch cross, energy storage inductor L ₀, L ₁... L _nmagnetic and and input ac power u dispel _itogether jointly to all storage capacitors, DC load power supply.Large step-up ratio impedance network and single-phase high frequency hybrid modulation switch (single-phase rectification bridge) are by input ac voltage u _ibe modulated into the tri-state SPWM ripple u that amplitude changes by sinusoidal rule by the variation of one times of incoming frequency sinusoidal envelope wire gauge rule, pulsewidth ₁, single-phase high frequency hybrid modulation switch (single-phase rectification bridge) is by u ₁be rectified into the high frequency pulse dc voltage wave u that amplitude changes by sinusoidal rule by the variation of two times of incoming frequency sinusoidal envelope wire gauge rules, pulsewidth ₂, after output filtering, in DC load, obtain high-quality direct voltage U _o.

Single-stage and-phase A.C.-D.C. converter of the present invention, be the single-level circuit structure that the input that utilizes SLCC type two port Impedance network element that the n of sequentially cascade is identical and prime two port Impedance network element to be output as rear class two port Impedance network element improves converter boost ratio, exist difference in essence with traditional single-stage and-phase PWM A.C.-D.C. converter (no matter whether adding single-phase input Industrial Frequency Transformer) circuit structure.Therefore, single-stage and-phase A.C.-D.C. converter of the present invention has novelty and creativeness, and there is conversion efficiency high (meaning that energy loss is little), power density is high (means volume, weight is little), step-up ratio large (meaning that the single-phase input ac voltage that excursion is wider or lower can be transformed into required output dc voltage), input current waveform distortion is little, output voltage waveforms ripple is little, reliability is high, input voltage preparation flexibly, cost is low, the advantages such as application prospect is extensive, it is a kind of desirable energy-saving and cost-reducing type single phase alternating current (A.C.)-DC converter, vigorously advocating, construction is energy-saving, have more important value today of conservation-minded society.

The accurate source of resistance A.C.-D.C. converter of the large step-up ratio cascade voltage of single-stage and-phase type circuit topology embodiment, as shown in figure 20.In Figure 20, output filter is LC filter circuit; Single-phase high frequency hybrid modulation switch (single-phase rectification bridge) is selected MOSFET device, also can select the devices such as IGBT, GTR.Described single-stage and-phase A.C.-D.C. converter can be transformed into a kind of unsettled low-voltage AC (as wind energy conversion system, ground AC power and aviation AC power etc.) required stable, high-quality, high voltage direct current, is widely used in Small And Medium Capacity, the civilian industry single-phase rectifier power of the occasion of boosting (as communication rectifier and wind power generation rectifier 220V50HzAC/380VDC, frequency-changing AC voltage/380VDC) and national defense industry rectifier power source (as aviation rectifier 115V400HzAC/270VDC) etc.

Each energy storage inductor of the accurate source of resistance A.C.-D.C. converter of the large step-up ratio cascade voltage of single-stage and-phase type is a HF switch cycle T _srespectively once, during magnetizing, correspondence is descended brachium pontis conduction period D to the magnetic that inside magnetizes and dispel ₀t _s, and (1-D during corresponding brachium pontis cross-conduction during the magnetic of dispelling ₀) T _s(during DC side output energy).Described single-stage and-phase A.C.-D.C. converter brachium pontis conduction period D under energy storage inductor when the positive and negative half cycle of input voltage ₀t _sthe equivalent electric circuit that magnetizes, brachium pontis cross-conduction during (1-D ₀) T _sthe magnetic equivalent electric circuit of dispelling, respectively as shown in Figure 21,22,23,24.In Figure 21,22,23,24, input voltage u _ipolarity be reference direction, and each current polarity is actual direction.

If storage capacitor terminal voltage is a HF switch cycle T _sbe inside invariable, use , represent; Input DC power current i _ienergy storage inductor L namely ₀current i _l0.By energy storage inductor shown in Figure 21,23 in high frequency hybrid modulation switch S ₃ ^', S ₄ ^', S ₁ ^'(S ₂ ^') conduction period D ₀t _sthe equivalent electric circuit that magnetizes can obtain formula (1.0)-(1.n); By energy storage inductor shown in Figure 22,24 in high frequency hybrid modulation switch S ₁ ^', S ₄ ^'(S ₂ ^', S ₃ ^') conduction period (1-D ₀) T _sthe magnetic equivalent electric circuit of dispelling can obtain formula (2.0)-(2.n); If high frequency hybrid modulation switch S ₁ ^', S ₄ ^'(S ₂ ^', S ₃ ^') conduction period (1-D ₀) T _svoltage magnitude be U ₁, can obtain supplementary equation (3.1)-(3.n); According to State-space Averaging Principle, , order , association type (3), large step-up ratio impedance network storage capacitor magnitude of voltage , by formula (4.1)-(4.n) and formula (5), represented; The voltage magnitude U of high frequency hybrid modulation switch (single-phase rectification bridge) AC ₁voltage magnitude U with DC side ₂by formula (6), represented.During according to output inductor stable state weber equilibrium principle, can obtain

（11）

（12）

Therefore, the voltage transmission ratio of the accurate source of resistance A.C.-D.C. converter of the large step-up ratio cascade voltage of single-stage and-phase type is

（13）

From formula (13), the voltage transmission of described single-stage and-phase A.C.-D.C. converter ratio is at different n, D ₀during value, be all greater than 1, and the voltage transmission that is greater than traditional single stage PWM A.C.-D.C. converter compares D ₀(Buck type), 1/(1-D ₀) (Boost type).Particularly, can improve the step-up ratio of converter by increasing n value, therefore be called the accurate source of resistance A.C.-D.C. converter of the large step-up ratio cascade voltage of single-stage and-phase type.

The accurate source of resistance A.C.-D.C. converter of the large step-up ratio cascade voltage of single-stage and-phase type only has single-stage power conversion link, its control system need to realize the storage capacitor voltage of large step-up ratio impedance network and the control of output dc voltage, also needs the MPPT maximum power point tracking that realizes wind energy conversion system to control MPPT during wind power generation.Therefore, the dicyclo SPWM control strategy that this single-stage and-phase A.C.-D.C. converter adopts output dc voltage outer shroud, large step-up ratio impedance network storage capacitor voltage inter-loop to control, as shown in Figure 25,26.

Output voltage feedback signal U _ofwith reference voltage U _rsignal after comparison, error are amplified is as the reference signal U of interior ring _cnr, storage capacitor voltage feedback signal U _cnfafter absolute value circuit with reference signal U _cnrcomparison, error amplification obtain signal u _e, u _ewith triangular carrier u _cthe signal that friendship intercepts and input voltage polarity selection signal be output single-phase high frequency hybrid modulation switch (single-phase rectification bridge) S after suitable logical circuit ₁', S ₃', S ₂', S ₄' and the four-quadrant power switch S of large step-up ratio impedance network ₁, S ₂..., S _ncontrol signal.As input voltage u _ior output loading Z _lduring variation, by regulating duty cycle signals D ₀realize output voltage U _ostable.Therefore the dicyclo SPWM control strategy that, described single-stage and-phase A.C.-D.C. converter adopts output dc voltage outer shroud, large step-up ratio impedance network storage capacitor voltage inter-loop to control is practicable.

Below in conjunction with drawings and Examples, technical scheme 4 of the present invention is described further.

The accurate source of resistance ac-to-ac converter of the large step-up ratio cascade voltage of single-stage and-phase type is to consist of input single-phase AC power, large step-up ratio impedance network, single-phase high frequency hybrid modulation switch, single phase filter and sequentially cascade of single phase alternating current (A.C.) load; Described large step-up ratio impedance network is by energy storage inductor L ₀the n of sequentially cascade identical SLCC type two port Impedance network element are in series, and wherein n is greater than 1 natural number; Each SLCC type two port Impedance network element is by a four-quadrant power switch S _j, an energy storage inductor L _j, two storage capacitor C _jand C _j' form four-quadrant power switch S _jone end and energy storage inductor L _jone end, storage capacitor C _jone end be connected, four-quadrant power switch S _jthe other end, energy storage inductor L _jthe other end respectively with storage capacitor C _j' two ends be connected, storage capacitor C _jthe other end and the reference negative polarity end of input single-phase AC power connect into common port, four-quadrant power switch S _jwith storage capacitor C _j' link and storage capacitor C _jcommon port formed the input port of j SLCC type two port Impedance network element, energy storage inductor L _jwith storage capacitor C _j' link and storage capacitor C _jcommon port formed the output port of j SLCC type two port Impedance network element, four-quadrant power switch S ₁with storage capacitor C ₁' link and the reference positive ends of input single-phase AC power between be in series with energy storage inductor L ₀, wherein j is the natural number that is not more than n; Described single-phase high frequency hybrid modulation switch is to consist of a four-quadrant power switch that bears bi-directional voltage stress and bidirectional current stress.

The large step-up ratio cascade voltage of single-stage and-phase type accurate source of resistance ac-to-ac converter circuit structure and principle waveform, respectively as shown in Figure 27,28.In Figure 27,28, u _ifor input single-phase alternating voltage, Z _lfor single-phase output AC load (comprising single phase alternating current (A.C.) passive load and the load of single phase alternating current (A.C.) electrical network), u _o, i _obe respectively single-phase output AC voltage and alternating current.Large step-up ratio impedance network is by energy storage inductor L ₀the n of sequentially cascade identical SLCC type two port Impedance network element are in series, and wherein n is greater than 1 natural number, and each SLCC type two port Impedance network element is by a four-quadrant power switch S _j, an energy storage inductor L _j, two storage capacitor C _jand C _j' form; Single-phase high frequency hybrid modulation switch is to consist of a four-quadrant power switch that can bear bi-directional voltage stress and bidirectional current stress; Single phase filter is single-phase LC filter (during single phase alternating current (A.C.) passive load) or single-phase LCL filter (during the load of single phase alternating current (A.C.) electrical network); Input ac power u _iand between large step-up ratio impedance network, can arrange or input filter is not set, when input filter is set, can reduce the harmonic content of input AC electric current.When single-phase high frequency hybrid modulation switch conduction, input ac power u _iwith all storage capacitors to energy storage inductor L ₀, L ₁... L _nmagnetize, output AC load relies on filter to maintain power supply; When single-phase high frequency hybrid modulation switch ends, energy storage inductor L ₀, L ₁... L _nmagnetic and and input ac power u dispel _itogether jointly to all storage capacitors, AC load power supply.Large step-up ratio impedance network and single-phase high frequency hybrid modulation switch are by input ac voltage u _ibe modulated into amplitude by the variation of one times of incoming frequency sinusoidal envelope wire gauge rule, the essentially identical tri-state SPWM ripple of pulsewidth u ₁(u ₂), after output filtering, in AC load, obtain high-quality sinusoidal voltage u _o.

Single-stage and-phase ac-to-ac converter of the present invention, be the single-level circuit structure that the input that utilizes SLCC type two port Impedance network element that the n of sequentially cascade is identical and prime two port Impedance network element to be output as rear class two port Impedance network element improves converter boost ratio, exist difference in essence with traditional single-stage and-phase PWM ac-to-ac converter (no matter whether adding the single-phase Industrial Frequency Transformer that inputs or outputs) circuit structure.Therefore, single-stage and-phase ac-to-ac converter of the present invention has novelty and creativeness, and there is conversion efficiency high (meaning that energy loss is little), power density is high (means volume, weight is little), step-up ratio large (meaning that the single-phase input ac voltage that excursion is wider or lower can be transformed into needed single-phase output AC voltage), net side power factor is high, output voltage THD is little, reliability is high, input voltage preparation flexibly, cost is low, the advantages such as application prospect is extensive, it is a kind of desirable energy-saving and cost-reducing type single phase alternating current (A.C.)-AC converter, vigorously advocating, construction is energy-saving, have more important value today of conservation-minded society.

The accurate source of resistance ac-to-ac converter of the large step-up ratio cascade voltage of single-stage and-phase type circuit topology embodiment, as shown in figure 29.What Figure 29 provided is single-phase LC filter circuit, does not provide as space is limited and is applicable to the single-phase LCL filter circuit higher to output waveform quality requirement; Single-phase high frequency hybrid modulation switch is selected MOSFET device, also can select the devices such as IGBT, GTR.Described ac-to-ac converter can be transformed into a kind of unsettled single-phase low-voltage AC (as wind energy conversion system, ground AC power and aviation AC power etc.) required stable, high-quality, high-voltage one-phase alternating current, is widely used in Small And Medium Capacity, the civilian industry single phase alternating current (A.C.) voltage stabilizing of the occasion of boosting and variable-voltage power supply (as electronic transformer 110V50HzAC/220V50HzAC) and national defense industry AC voltage-stabilizing and variable-voltage power supply (as aviation electronics transformer 36V400HzAC/115V400HzAC) etc.

Each energy storage inductor of the accurate source of resistance ac-to-ac converter of the large step-up ratio cascade voltage of single-stage and-phase type is a HF switch cycle T _sinside magnetize and dispel magnetic each once, D during corresponding single-phase high frequency hybrid modulation switch conduction during magnetizing ₀t _s, and corresponding single-phase high frequency hybrid modulation switch (1-D between the off period during the magnetic of dispelling ₀) T _s(during load-side output energy).Described ac-to-ac converter is energy storage inductor D during single-phase high frequency hybrid modulation switch conduction in the positive and negative half cycle situation of input (output) voltage ₀t _sthe equivalent electric circuit that magnetizes, (1-D between the off period ₀) T _sthe magnetic equivalent electric circuit of dispelling, respectively as shown in Figure 30,31,32,33.In Figure 30,31,32,33, input voltage u _ipolarity be reference direction, and each current polarity is actual direction.

If storage capacitor terminal voltage is a HF switch cycle T _sbe inside invariable, use , represent; Input DC power current i _ienergy storage inductor L namely ₀current i _l0.By energy storage inductor shown in Figure 30,32 in single-phase high frequency hybrid modulation switch S ₁ ^'conduction period D ₀t _sthe equivalent electric circuit that magnetizes can obtain formula (1.0)-(1.n); By energy storage inductor shown in Figure 31,33 in single-phase high frequency hybrid modulation switch S ₁ ^'(1-D between the off period ₀) T _sthe magnetic equivalent electric circuit of dispelling can obtain formula (2.0)-(2.n); If single-phase high frequency hybrid modulation switch S ₁ ^'(1-D between the off period ₀) T _svoltage magnitude be U ₁(U ₂), can obtain supplementary equation (3.1)-(3.n); According to State-space Averaging Principle, , order , association type (3), large step-up ratio impedance network storage capacitor magnitude of voltage , by formula (4.1)-(4.n) and formula (5), represented; Single-phase high frequency hybrid modulation switch S ₁ ^'voltage magnitude U during cut-off ₁(U ₂) by formula (6), represented.During according to output inductor stable state weber equilibrium principle, can obtain

（14）

（15）

Therefore, the voltage transmission ratio of the accurate source of resistance ac-to-ac converter of the large step-up ratio cascade voltage of single-stage and-phase type is

（16）

From formula (16), the voltage transmission of described single-stage and-phase ac-to-ac converter ratio is at different n, D ₀during value, be all greater than 1, and the voltage transmission that is greater than traditional single stage PWM ac-to-ac converter compares D ₀(Buck type), 1/(1-D ₀) (Boost type), D ₀/ (1-D ₀) (Buck-Boost type).Particularly, can improve the step-up ratio of converter by increasing n value, therefore be called the accurate source of resistance ac-to-ac converter of the large step-up ratio cascade voltage of single-stage and-phase type.

The accurate source of resistance ac-to-ac converter of the large step-up ratio cascade voltage of single-stage and-phase type only has single-stage power conversion link, and its control system need to realize the control of output AC voltage, also needs the MPPT maximum power point tracking that realizes wind energy conversion system to control MPPT during wind power generation.Therefore, this single-stage and-phase ac-to-ac converter adopts output AC voltage instantaneous values feedback PWM control strategy, as shown in Figure 34,35.

Output voltage feedback signal u _ofwith reference voltage u _rcomparison, error obtain signal u after amplifying, taking absolute value _e, u _ewith triangular carrier u _cthe signal that friendship intercepts and inversion signal thereof are respectively as single-phase high frequency hybrid modulation switch S ₁' and the four-quadrant power switch S of large step-up ratio impedance network ₁, S ₂..., S _ncontrol signal.As input voltage u _ior output loading Z _lduring variation, by regulating duty cycle signals D ₀realize output voltage u _ostable.Therefore, described single-stage and-phase ac-to-ac converter employing output AC voltage instantaneous values feedback PWM control strategy is practicable.

Claims

1. the accurate source of resistance converter of the large step-up ratio cascade voltage of single-stage and-phase type, is characterized in that: this converter circuit structure is to consist of input DC power, large step-up ratio impedance network, single-phase high frequency hybrid modulation switch, single phase filter and sequentially cascade of single phase alternating current (A.C.) load; Described large step-up ratio impedance network is by energy storage inductor L ₀the n of sequentially cascade identical SLCC type two port Impedance network element are in series, and wherein n is greater than 1 natural number; Each SLCC type two port Impedance network element is by a power diode S _j, an energy storage inductor L _j, two storage capacitor C _jand C _j' form power diode S _jnegative electrode and energy storage inductor L _jone end, storage capacitor C _jpositive ends be connected, energy storage inductor L _jthe other end, power diode S _janode respectively with storage capacitor C _j' positive and negative polarity end be connected, storage capacitor C _jnegative polarity end and the negative polarity end of input DC power connect into common port, power diode S _jwith storage capacitor C _j' link and storage capacitor C _jcommon port formed the input port of j SLCC type two port Impedance network element, energy storage inductor L _jwith storage capacitor C _j' link and storage capacitor C _jcommon port formed the output port of j SLCC type two port Impedance network element, power diode S _jwith storage capacitor C ₁' link and input DC power positive ends between be in series with energy storage inductor L ₀, wherein j is the natural number that is not more than n; Described single-phase high frequency hybrid modulation switch is to consist of four two quadrant power switchs that bear unidirectional voltage stress and bidirectional current stress; By regulating the exponent number n of SLCC type two port Impedance network element and the duty ratio D that magnetizes of converter energy storage inductor ₀=T ₀/ T _srealize the adjusting of converter boost ratio, wherein T _sfor HF switch cycle, T ₀for single-phase high frequency hybrid modulation switch is at a T _sthe interior bridge arm direct pass time; Each energy storage inductor of the accurate source of resistance converter of the large step-up ratio cascade voltage of described single-stage and-phase type is a HF switch cycle T _sinside magnetize and dispel magnetic each once, D during corresponding bridge arm direct pass during magnetizing ₀t _s, and during the magnetic of dispelling corresponding brachium pontis non-straight-through during (1-D ₀) T _sincluded to during two zero vectors outer during AC output energy, bridge arm direct pass, comprise D during bridge arm direct pass ₀t _smagnetize and brachium pontis non-straight-through during (1-D ₀) T _sand the five kinds of operation modes of magnetic of dispelling when lower brachium pontis conducting, output voltage negative half period, the positive half cycle of output voltage and upper brachium pontis conducting, the voltage transmission ratio of the accurate source of resistance converter of the large step-up ratio cascade voltage of described single-stage and-phase type is , wherein M is the index of modulation of single-phase high frequency hybrid modulation switch, at different n, M and D ₀during value, voltage transmission is less than, is equal to and greater than 1 three kinds of situations than existing, as M > 1-(n+1) D ₀time, for example get n=2 and M > 1-3D ₀, voltage transmission ratio is greater than 1, can improve by increasing n value the step-up ratio of converter; The accurate source of resistance converter using of the large step-up ratio cascade voltage of described single-stage and-phase type has output voltage or the grid-connected current instantaneous values feedback Unipolar SPWM control strategy of large step-up ratio impedance network storage capacitor voltage feedforward control, output voltage or grid-connected current instantaneous values feedback Unipolar SPWM control strategy are used for regulating index of modulation M, and large step-up ratio impedance network storage capacitor voltage U _cnfeed-forward Control Strategy is used for regulating straight-through duty ratio D ₀.

2. the accurate source of resistance converter of the large step-up ratio cascade voltage of single-stage and-phase type, is characterized in that: this converter circuit structure is to consist of input DC power, large step-up ratio impedance network, high frequency hybrid modulation switch, filter and sequentially cascade of DC load; Described large step-up ratio impedance network is by energy storage inductor L ₀the n of sequentially cascade identical SLCC type two port Impedance network element are in series, and wherein n is greater than 1 natural number; Each SLCC type two port Impedance network element is by a power diode S _j, an energy storage inductor L _j, two storage capacitor C _jand C _j' form power diode S _jnegative electrode and energy storage inductor L _jone end, storage capacitor C _jpositive ends be connected, energy storage inductor L _jthe other end, power diode S _janode respectively with storage capacitor C _j' positive and negative polarity end be connected, storage capacitor C _jnegative polarity end and the negative polarity end of input DC power connect into common port, power diode S _jwith storage capacitor C _j' link and storage capacitor C _jcommon port formed the input port of j SLCC type two port Impedance network element, energy storage inductor L _jwith storage capacitor C _j' link and storage capacitor C _jcommon port formed the output port of j SLCC type two port Impedance network element, power diode S _jwith storage capacitor C ₁' link and input DC power positive ends between be in series with energy storage inductor L ₀, wherein j is the natural number that is not more than n; Described high frequency hybrid modulation switch is to consist of two quadrant power switchs that bear unidirectional voltage stress and bidirectional current stress; By regulating the exponent number n of SLCC type two port Impedance network element and the duty ratio D that magnetizes of converter energy storage inductor ₀=T ₀/ T _srealize the adjusting of converter boost ratio, wherein T _sfor HF switch cycle, T ₀for high frequency hybrid modulation switch is at a T _sinterior ON time; Each energy storage inductor of the accurate source of resistance converter of the large step-up ratio cascade voltage of described single-stage and-phase type is a HF switch cycle T _sinside magnetize and dispel magnetic each once, D during corresponding high frequency hybrid modulation switch conduction during magnetizing ₀t _s, and corresponding high frequency hybrid modulation switch (1-D between the off period during the magnetic of dispelling ₀) T _s, comprise conduction period D ₀t _smagnetize and (1-D between the off period ₀) T _sthe two kinds of operation modes of magnetic of dispelling; The voltage transmission ratio of the accurate source of resistance converter of the large step-up ratio cascade voltage of described single-stage and-phase type is , different n, D ₀during value, voltage transmission is greater than 1 than all, and is greater than the voltage transmission ratio of traditional single stage PWM DC-DC converter, can improve by increasing n value the step-up ratio of converter.

3. the accurate source of resistance converter of the large step-up ratio cascade voltage of single-stage and-phase type, is characterized in that: this converter circuit structure is to consist of input single-phase AC power, large step-up ratio impedance network, single-phase high frequency hybrid modulation switch, filter and sequentially cascade of DC load; Described large step-up ratio impedance network is by energy storage inductor L ₀the n of sequentially cascade identical SLCC type two port Impedance network element are in series, and wherein n is greater than 1 natural number; Each SLCC type two port Impedance network element is by a four-quadrant power switch S _j, an energy storage inductor L _j, two storage capacitor C _jand C _j' form four-quadrant power switch S _jone end and energy storage inductor L _jone end, storage capacitor C _jone end be connected, four-quadrant power switch S _jthe other end, energy storage inductor L _jthe other end respectively with storage capacitor C _j' two ends be connected, storage capacitor C _jthe other end and the reference negative polarity end of input single-phase AC power connect into common port, four-quadrant power switch S _jwith storage capacitor C _j' link and storage capacitor C _jcommon port formed the input port of j SLCC type two port Impedance network element, energy storage inductor L _jwith storage capacitor C _j' link and storage capacitor C _jcommon port formed the output port of j SLCC type two port Impedance network element, four-quadrant power switch S _jwith storage capacitor C ₁' link and the reference positive ends of input single-phase AC power between be in series with energy storage inductor L ₀, wherein j is the natural number that is not more than n; Described single-phase high frequency hybrid modulation switch is to consist of four two quadrant power switchs that bear unidirectional voltage stress and bidirectional current stress; By regulating the exponent number n of SLCC type two port Impedance network element and the duty ratio D that magnetizes of converter energy storage inductor ₀=T ₀/ T _srealize the adjusting of converter boost ratio, wherein T _sfor HF switch cycle, T ₀for single-phase high frequency hybrid modulation switch is at a T _sinterior ON time; Each energy storage inductor of the accurate source of resistance converter of the large step-up ratio cascade voltage of described single-stage and-phase type is a HF switch cycle T _srespectively once, during magnetizing, correspondence is descended brachium pontis conduction period D to the magnetic that inside magnetizes and dispel ₀t _s, and (1-D during corresponding brachium pontis cross-conduction during the magnetic of dispelling ₀) T _s, brachium pontis conduction period D under energy storage inductor while comprising the positive and negative half cycle of input voltage ₀t _smagnetize, (1-D during brachium pontis cross-conduction ₀) T _sthe four kinds of operation modes of magnetic of dispelling; The voltage transmission ratio of the accurate source of resistance converter of the large step-up ratio cascade voltage of described single-stage and-phase type is , different n, D ₀during value, voltage transmission is greater than 1 than all, and is greater than the voltage transmission ratio of traditional single stage PWM A.C.-D.C. converter, can improve by increasing n value the step-up ratio of converter.

4. the accurate source of resistance converter of the large step-up ratio cascade voltage of single-stage and-phase type, is characterized in that: this converter circuit structure is to consist of input single-phase AC power, large step-up ratio impedance network, single-phase high frequency hybrid modulation switch, single phase filter and sequentially cascade of single phase alternating current (A.C.) load; Described large step-up ratio impedance network is by energy storage inductor L ₀the n of sequentially cascade identical SLCC type two port Impedance network element are in series, and wherein n is greater than 1 natural number; Each SLCC type two port Impedance network element is by a four-quadrant power switch S _j, an energy storage inductor L _j, two storage capacitor C _jand C _j' form four-quadrant power switch S _jone end and energy storage inductor L _jone end, storage capacitor C _jone end be connected, four-quadrant power switch S _jthe other end, energy storage inductor L _jthe other end respectively with storage capacitor C _j' two ends be connected, storage capacitor C _jthe other end and the reference negative polarity end of input single-phase AC power connect into common port, four-quadrant power switch S _jwith storage capacitor C _j' link and storage capacitor C _jcommon port formed the input port of j SLCC type two port Impedance network element, energy storage inductor L _jwith storage capacitor C _j' link and storage capacitor C _jcommon port formed the output port of j SLCC type two port Impedance network element, four-quadrant power switch S _jwith storage capacitor C ₁' link and the reference positive ends of input single-phase AC power between be in series with energy storage inductor L ₀, wherein j is the natural number that is not more than n; Described single-phase high frequency hybrid modulation switch is to consist of a four-quadrant power switch that bears bi-directional voltage stress and bidirectional current stress; By regulating the exponent number n of SLCC type two port Impedance network element and the duty ratio D that magnetizes of converter energy storage inductor ₀=T ₀/ T _srealize the adjusting of converter boost ratio, wherein T _sfor HF switch cycle, T ₀for single-phase high frequency hybrid modulation switch is at a T _sinterior ON time; Each energy storage inductor of the accurate source of resistance converter of the large step-up ratio cascade voltage of described single-stage and-phase type is a HF switch cycle T _sinside magnetize and dispel magnetic each once, D during corresponding single-phase high frequency hybrid modulation switch conduction during magnetizing ₀t _s, and corresponding single-phase high frequency hybrid modulation switch (1-D between the off period during the magnetic of dispelling ₀) T _s, energy storage inductor D during single-phase high frequency hybrid modulation switch conduction while comprising the positive and negative half cycle of input voltage ₀t _smagnetize and (1-D between the off period ₀) T _sthe four kinds of operation modes of magnetic of dispelling; The voltage transmission ratio of the accurate source of resistance parallel operation of the large step-up ratio cascade voltage of described single-stage and-phase type is , different n, D ₀during value, voltage transmission is greater than 1 than all, and is greater than the voltage transmission ratio of traditional single stage PWM ac-to-ac converter, can improve by increasing n value the step-up ratio of converter.