CN204046455U - Flyback high frequency isolation type three-level inverter - Google Patents

Abstract

The utility model discloses a kind of flyback high frequency isolation type three-level inverter.The circuit structure of this inverter is made up of input DC power, input filter, high frequency isolation type flyback three level converter unit, frequency converter, output filter and AC load; The utility model can realize the function of the sinusoidal voltage by unstable, DC voltage conversion inferior being required stable, high-quality.By changing the type of high frequency isolation type flyback three level converter unit and frequency converter, the circuit topology race of single switch flyback type, Dual Switch Flyback, half bridge flyback type, full-bridge flyback high-frequency isolation three-level inverter can be obtained.The utility model has the good features such as circuit topology is succinct, bidirectional power flow Two Stages, power switch pipe voltage stress are little, output filter front voltage spectral characteristic is good, output filter volume is little, adaptive load ability is strong, is applicable to high voltage input occasion.

Description

Flyback high frequency isolation type three-level inverter

Technical field

The utility model belongs to Technics of Power Electronic Conversion technical field, particularly a kind of flyback high frequency isolation type three-level inverter.

Background technology

DC-AC converter technique is applied power semiconductor device, direct current energy is converted to a kind of static ac dc converter technology of constant voltage constant frequency AC energy, for AC load, be widely used in national defence, industrial and mining enterprises, scientific research institutions, laboratory in colleges and universities and daily life.

Up to now, domestic and international power electronics researcher, for the research of straight-AC-AC converter, mainly concentrates on that non-electrical is isolated, two level such as low frequency and high frequency electrical isolation formula are straight-AC-AC converter; For the research of multi-level converter, mainly concentrate on many level straight-straight, hand over-hand over and friendship-DC converter, for many level straight-research of AC-AC converter is then considerably less, and be only confined to non-isolated, low frequency or the isolated many level of intermediate frequency straight-AC-AC converter, fewer to the inverter research of high frequency isolation type many level two stage power conversion.

Since German scholar Holtz proposes the three-level inverter main circuit utilizing switching tube to carry out auxiliary neutral point clamp first, the people such as the A Nabae of Japan are developed it, propose diode clamp formula multi-level inverter circuit.Through the development of decades, multi-level inverse conversion technology mainly contains three class topological structures at present: (1) Diode-clamped inverter, (2) striding capacitance Clamp inverter, (3) cascade multilevel inverter.Mr.ESPELAGE proposed the new ideas of High Frequency Link inversion transformation technique in 1977, utilize the Industrial Frequency Transformer in high frequency transformer replacement traditional low-frequency link inversion transformation technique, overcome the shortcoming of low frequency inversion transformation technique, significantly improve the characteristic of inverter, low frequency link inverter will be replaced, be used widely.

Nearly ten years, around high frequency link inversion transformation technique, Chinese scholars has done a large amount of research work, achieves many valuable achievements in research.Within 1998, Zhejiang University doctor Huang Minchao proposes the Current-Source Mode High Frequency chain inverter circuit structure based on buck-boost (flyback) converter, comprise that single tube is unidirectional, single tube is two-way, recommend, half-bridge and full-bridge type topology, this serial back exciting converter has that topology is succinct, two stage power conversion, conversion efficiency is high, reliability is high, export and only need the advantages such as capacitor filtering.But they are two-level inverter, due to the restriction of topology, its switch tube voltage and current stress are all larger, and output capacity is little, can not be applied in high-tension high-power transformation of electrical energy occasion.

Utility model content

The purpose of this utility model is to provide the flyback high frequency isolation type three-level inverter that one has two stage power conversion (direct current DC-high-frequency ac HFAC-low-frequency ac LFAC), bidirectional power flow, output filter front voltage spectral characteristic are good, the voltage stress of high power density, reduction switching device, output filter volume are little, can realize AC load and DC power supply high frequency electrical isolation.

The technical solution realizing the utility model object is:

A kind of flyback high frequency isolation type three-level inverter, is made up of the input dc power source unit connected successively, input filter, high frequency isolation type flyback three level converter unit, frequency converter, output filter and AC load, wherein:

Input dc power source unit is connected with input filter one end, the input filter other end is connected with high frequency isolation type flyback three level converter unit one end, the high frequency isolation type flyback three level converter unit other end is connected with frequency converter one end through high frequency isolation type transformer, the frequency converter other end is connected with output filter one end, and the output filter other end is connected with AC load.

As optional execution mode, flyback high frequency isolation type three-level inverter can adopt the one in single switch flyback type topology, Dual Switch Flyback topological, half bridge flyback type topology, full-bridge flyback topology.

For single switch flyback type topology, according to of the present utility model open, flyback high frequency isolation type three-level inverter is made up of the input DC power connected successively, input filter, high frequency isolation type flyback three level converter unit, frequency converter, output filter and AC load; Wherein: input dc power source unit is connected with input filter one end, the input filter other end is connected with high frequency isolation type flyback three level converter unit one end, the high frequency isolation type flyback three level converter unit other end is connected with frequency converter one end, the frequency converter other end is connected with output filter one end, and the output filter other end is connected with output AC load.Namely the positive pole of input DC power is connected with the positive pole of the first input filter capacitor, and the negative pole of input DC power is connected with the negative pole of the second input filter capacitor, described input filter is made up of the first input filter capacitor and the second input filter capacitor, the negative pole of the first input filter capacitor is connected with the positive pole of the second input filter capacitor, described single switch flyback high-frequency isolation three level converter unit is made up of the first power switch pipe, the second power switch pipe, the first diode, the second diode, the 3rd diode, high frequency isolation type transformer first former limit winding, high-frequency isolation transformer first vice-side winding, high-frequency isolation transformer second vice-side winding, the drain electrode of the first power switch pipe is connected with the positive pole of the first input filter capacitor, first diode inverse parallel is in the two ends of the first power switch pipe, namely the negative electrode of the first diode is connected with the drain electrode of the first power switch pipe, the anode of the first diode is connected with the source electrode of the first power switch pipe, the negative pole of the 3rd diode anode and the first input filter capacitor, the positive pole of the second input filter capacitor is connected, the negative electrode of the 3rd diode is connected with the source electrode of the first power switch pipe, the Same Name of Ends of high frequency isolation type transformer first former limit winding and the source electrode of the first power switch pipe, the negative electrode of the 3rd diode is connected, the drain electrode of the second power switch pipe is connected with the non-same polarity of high-frequency isolation transformer first former limit winding, second diode inverse parallel is in the two ends of the second power switch pipe, namely the negative electrode of the second diode is connected with the drain electrode of the second power switch pipe, the anode of the second diode is connected with the source electrode of the second power switch pipe, the source electrode of the second power switch pipe is connected with the negative pole of the second input filter capacitor, the Same Name of Ends of high-frequency isolation transformer first vice-side winding is connected with the non-same polarity of high-frequency isolation transformer second vice-side winding.Described full wave type frequency converter is made up of the first two-way power switch pipe and the second two-way power switch pipe, the first described two-way power switch pipe and the second two-way power switch pipe are all form by two single power switch pipe differential concatenations the switch bearing forward, reverse voltage stress and current stress, have two-way blocking-up function, first two-way power switch pipe comprises the 3rd power switch pipe, the 4th power switch pipe, the 4th diode, the 5th diode, and the second two-way power switch pipe comprises the 5th power switch pipe, the 6th power switch pipe, the 6th diode, the 7th diode, one end of first two-way power switch pipe is connected with the non-same polarity of high-frequency isolation transformer first vice-side winding, one end of second two-way power switch pipe and the Same Name of Ends of high-frequency isolation transformer second vice-side winding be connected, the other end of the second two-way power switch pipe is connected with the other end of the first two-way power switch pipe, the drain electrode of the 3rd power switch pipe is connected as one end of the first two-way power switch pipe with the negative electrode of the 4th diode, the drain electrode of the 4th power switch pipe is connected as the other end of the first two-way power switch pipe with the negative electrode of the 5th diode, the source electrode of the 3rd power switch pipe, the source electrode of the 4th power switch pipe, the anode of the 4th diode, the anode of the 5th diode links together, the drain electrode of the 5th power switch pipe is connected as one end of the second two-way power switch pipe with the negative electrode of the 6th diode, the drain electrode of the 6th power switch pipe is connected as the other end of the second two-way power switch pipe with the negative electrode of the 7th diode, the source electrode of the 5th power switch pipe, the source electrode of the 6th power switch pipe, the anode of the 6th diode, the anode of the 7th diode links together.Described output filter comprises output filter capacitor; The negative electrode of the positive pole of output filter capacitor and the drain electrode of the 4th power switch pipe, the 5th diode, the drain electrode of the 6th power switch pipe, the negative electrode of the 7th diode are connected, and the negative pole of output filter capacitor is connected with the non-same polarity of the Same Name of Ends of high-frequency isolation transformer first vice-side winding, high-frequency isolation transformer second vice-side winding.Described output AC load comprises AC load, and the positive pole of AC load is connected with the positive pole of output filter capacitor, and the negative pole of AC load is connected with the negative pole of output filter capacitor.

Compared with prior art, remarkable advantage of the present utility model is the utility model:

(1) the structure thinking of Clamp many level topology is applied in traditional B uck-boost type (flyback) inverter.And high-frequency isolation transformer is inserted in input DC power and AC load, achieve the electrical isolation of input side and load-side, the use of high-frequency isolation transformer achieves the miniaturization of converter, lightweight, improves the efficiency of converter.

(2) compared with other topological form inverters, flyback inverter has topology succinct output filter volume little (only needing capacitor filtering), conversion efficiency advantages of higher, compared with traditional " two-way flyback annulus inverter in high frequency ", the utility model can obtain three level in output inductor front end, thus reduce the voltage stress of power switch pipe, widened the range of choice of power switch pipe, filtering capacitance is less, is applicable to high voltage input occasion.Require the high-voltage large-capacity inversion occasion of electrical isolation civilian, industrial, national defence etc., adopt inversion topological of the present utility model to be more satisfactory inverter solution.

(3) the utility model has power conversion progression few (direct current DC-high-frequency ac HFAC-low-frequency ac LFAC), bidirectional power flow, at an output AC high frequency intra-cycle isolating transformer magnetic core by two-way magnetization, the utilance of magnetic core of transformer is high, the advantages such as output filter front voltage spectral characteristic is good, thus improve conversion efficiency and power density, reduction volume and weight.

Accompanying drawing explanation

Fig. 1 is the circuit topological structure figure of the utility model flyback high frequency isolation type three-level inverter.

Fig. 2 is the circuit topological structure figure of the utility model single switch flyback high frequency isolation type three-level inverter.

Fig. 3 is the circuit topological structure figure of the utility model double-transistor flyback high frequency isolation type three-level inverter.

Fig. 4 is the circuit topological structure figure of the utility model half bridge flyback high frequency isolation type three-level inverter.

Fig. 5 is the circuit topological structure figure of the utility model full-bridge flyback high frequency isolation type three-level inverter.

Embodiment

The basic functional principle of the utility model flyback high frequency isolation type three-level inverter is as follows: this inverter can adopt the control mode of pulse modulation (SPWM) copped wave of active-clamp.When the high input voltage DC power supply U of instability is to AC load Z _lduring transmitted power, DC input voitage can obtain two kinds of level (+U ,+U/2) after input filter filtering dividing potential drop, direct voltage energy conversion becomes the current energy of pulsation to be stored in storage transformer by high-frequency isolation transformer, frequency converter is by the electric current low frequency demodulation of this dither, after filtering, obtain low frequency ac, power to load; When load is to input power feedback energy, frequency converter is operated in modulation condition, and flyback high frequency isolation type three level converter unit is operated in rectification state.This inverter has four-quadrant operation ability, therefore can be with perception, capacitive, resistive and rectified load, and the control circuit of this inverter can adjust according to the character of AC load, thus obtains stable or adjustable voltage at output.

Below in conjunction with accompanying drawing, the utility model is described in further detail.

On the whole, by reference to the accompanying drawings 1, the flyback high frequency isolation type three-level inverter that the utility model proposes, is made up of the input DC power 1 connected successively, input filter 2, high frequency isolation type flyback three level converter unit 3, frequency converter 4, output filter 5 and AC load 5.The high voltage direct current of instability is transformed into stable or adjustable sine electricity by this converter, and reduces power conversion progression, realizes high frequency electrical isolation, is applicable to high voltage direct-alternation carry over and closes.

As shown in Figure 1, the positive pole of input DC power 1 is connected with the first input filter capacitor C1 positive pole, input DC power 1 negative pole is connected with the second input filter capacitor C2 negative pole, another one end of input filter capacitor 2 is connected with high frequency isolation type inverse-excitation converting unit 3, high frequency isolation type inverse-excitation converting unit 3 has the power switch pipe of diode and two or four clamp diode and high frequency storage transformer to form by several inverse parallel, input direct voltage is modulated into the current energy of dither, high frequency isolation type inverse-excitation converting unit 3 other end is connected with frequency converter 4, frequency converter 4 is made up of one or two bidirectional switch pipe, main by the demodulation of dither current low frequency, AC load is exported to after output filter capacitor filtering, the other end of frequency converter 4 is connected with output filter 5, AC load is parallel to output filter two ends.Relative classical inverse exciting converter, owing to introducing three level technology, the voltage stress that master power switch pipe bears is the half under two level modes, is applicable to the large-power occasions of high input voltage.

What the utility model proposed has the flyback high frequency isolation type three-level inverter of foregoing circuit structure by changing input filter, the structure of high frequency isolation type flyback three level converter unit and frequency converter can obtain different circuit topology races, comprise single switch flyback formula, double-transistor flyback formula, half bridge flyback formula and full-bridge inverse-excitation type four kinds of circuit topologies, all topologys in this circuit topology race all have identical diode clamp structure and high frequency electrical isolation, also there is part different simultaneously, single hose, double hose and full-bridge type have identical input filter, double hose, semibridge system and full-bridge type have identical frequency converter, single hose and double hose high-frequency isolation transformer have three windings, semibridge system and full bridge high frequency isolating transformer have two windings.

Wherein, single switch flyback type high frequency isolation type three-level inverter topology as shown in Figure 2.Its physical circuit is as follows: the input DC power 1 connected successively, input filter 2, single switch flyback high-frequency isolation three level converter unit 3, full wave type frequency converter 4, output filter 5 and AC load 6 form the single switch flyback circuit topology being applicable to high input voltage DC-AC conversion occasion.Namely the positive pole of input DC power Ui is connected with the positive pole of the first input filter capacitor C1, and the negative pole of input DC power Ui is connected with the negative pole of the second input filter capacitor C2, described input filter 2 is made up of the first input filter capacitor C1 and the second input filter capacitor C2, the negative pole of the first input filter capacitor C1 is connected with the positive pole of the second input filter capacitor C2, described single switch flyback high-frequency isolation three level converter unit 3 is made up of the first power switch tube S 1, second power switch tube S 2, first diode D1, the second diode D2, the 3rd diode D3, the former limit winding N1 of high frequency isolation type transformer T first, high-frequency isolation transformer T first vice-side winding N2, high-frequency isolation transformer T second vice-side winding N3, the drain electrode of the first power switch tube S 1 is connected with the positive pole of the first input filter capacitor C1, first diode D1 inverse parallel is in the two ends of the first power switch tube S 1, namely the negative electrode of the first diode D1 is connected with the drain electrode of the first power switch tube S 1, the anode of the first diode D1 is connected with the source electrode of the first power switch tube S 1, the negative pole of the 3rd diode D3 anode and the first input filter capacitor C1, the positive pole of the second input filter capacitor C2 is connected, the negative electrode of the 3rd diode D3 is connected with the source electrode of the first power switch tube S 1, the Same Name of Ends of the former limit winding N1 of high frequency isolation type transformer T first and the source electrode of the first power switch tube S 1, the negative electrode of the 3rd diode D3 is connected, the drain electrode of the second power switch tube S 2 is connected with the non-same polarity of high-frequency isolation transformer T first former limit winding N1, second diode D2 inverse parallel is in the two ends of the second power switch tube S 2, namely the negative electrode of the second diode D2 is connected with the drain electrode of the second power switch tube S 2, the anode of the second diode D2 is connected with the source electrode of the second power switch tube S 2, the source electrode of the second power switch tube S 2 is connected with the negative pole of the second input filter capacitor C2, the Same Name of Ends of high-frequency isolation transformer T first vice-side winding N2 is connected with the non-same polarity of high-frequency isolation transformer T second vice-side winding N3.Described full wave type frequency converter 4 is made up of the first two-way power switch pipe SA and the second two-way power switch pipe SB, the first described two-way power switch pipe SA and the second two-way power switch pipe SB forms by two single power switch pipe differential concatenations the switch bearing forward, reverse voltage stress and current stress, has two-way blocking-up function, first two-way power switch pipe SA comprises the 3rd power switch tube S 3, the 4th power switch tube S 4, the 4th diode D4, the 5th diode D5, second two-way power switch pipe SB comprises the 5th power switch tube S 5, the 6th power switch tube S 6, the 6th diode D6, the 7th diode D7, one end of first two-way power switch pipe SA is connected with the non-same polarity of high-frequency isolation transformer T first vice-side winding N2, one end of second two-way power switch pipe SB and the Same Name of Ends of high-frequency isolation transformer T second vice-side winding N3 be connected, the other end of the second two-way power switch pipe SB is connected with the other end of the first two-way power switch pipe SA, the drain electrode of the 3rd power switch tube S 3 is connected with the negative electrode of the 4th diode D4 as one end of the first two-way power switch pipe SA, the drain electrode of the 4th power switch tube S 4 is connected with the negative electrode of the 5th diode D5 as the other end of the first two-way power switch pipe SA, the source electrode of the 3rd power switch tube S 3, the source electrode of the 4th power switch tube S 4, the anode of the 4th diode D4, the anode of the 5th diode D5 links together, the drain electrode of the 5th power switch tube S 5 is connected with the negative electrode of the 6th diode D6 as one end of the second two-way power switch pipe SB, the drain electrode of the 6th power switch tube S 6 is connected with the negative electrode of the 7th diode D7 as the other end of the second two-way power switch pipe SB, the source electrode of the 5th power switch tube S 5, the source electrode of the 6th power switch tube S 6, the anode of the 6th diode D6, the anode of the 7th diode D7 links together.Described output filter 5 comprises output filter capacitor Cf; The negative electrode of the positive pole of output filter capacitor Cf and the drain electrode of the 4th power switch tube S 4, the 5th diode D5, the drain electrode of the 6th power switch tube S 6, the negative electrode of the 7th diode D7 are connected, and the negative pole of output filter capacitor Cf is connected with the non-same polarity of the Same Name of Ends of high-frequency isolation transformer T first vice-side winding N2, high-frequency isolation transformer T second vice-side winding N3.Described output AC load 6 comprises AC load ZL, and the positive pole of AC load ZL is connected with the positive pole of output filter capacitor Cf, and the negative pole of AC load ZL is connected with the negative pole of output filter capacitor Cf.

Dual Switch Flyback high frequency isolation type three-level inverter topology as shown in Figure 3.Its physical circuit connects as follows: the input DC power 1 connected successively, input filter 2, double-transistor flyback high-frequency isolation three level converter unit 3, frequency converter 4, output filter 5 and AC load 6 form the single switch flyback circuit topology being applicable to high input voltage DC-AC conversion occasion.Namely the positive pole of input DC power Ui is connected with the positive pole of the first input filter capacitor C1, and the negative pole of input DC power Ui is connected with the negative pole of the second input filter capacitor C2; Described input filter 2 is made up of the first input filter capacitor C1 and the second input filter capacitor C2; The negative pole of the first input filter capacitor C1 is connected with the positive pole of the second input filter capacitor C2; Described double-transistor flyback high-frequency isolation three level converter unit 3 is by the first power switch tube S 1, first diode D1, second power switch tube S 2, second diode D2, the 3rd power switch tube S the 3, three diode D3,4th power switch tube S 4,4th diode D4, the 5th diode D5 the 6th diode D6, high-frequency isolation transformer T first former limit winding N1, high-frequency isolation transformer T second former limit winding N2, high-frequency isolation transformer T first vice-side winding N3 are formed; the drain electrode of the first power switch tube S 1 is connected with the positive pole of the first input filter capacitor C1 with the drain electrode of the 3rd power switch tube S 3, the inverse parallel of first diode D1 and the 3rd diode D3 difference is in the first power switch tube S 1 and the 3rd power switch tube S 3 two ends, namely the negative electrode of the first diode D1 is connected with the drain electrode of the first power switch tube S 1, the anode of the first diode D1 is connected with the source electrode of the first power switch tube S 1, the negative electrode of the 3rd diode D3 is connected with the drain electrode of the 3rd power switch tube S 3, the anode of the 3rd diode D3 is connected with the source electrode of the 3rd power switch tube S 3, the source electrode of the first power switch tube S 1 is connected with the Same Name of Ends of high-frequency isolation transformer T first former limit winding N1, the source electrode of the 3rd power switch tube S 3 is connected with the non-same polarity of high-frequency isolation transformer T second former limit winding N2, the non-same polarity of high-frequency isolation transformer T first former limit winding N1 is connected with the drain electrode of the second power switch tube S 2, the Same Name of Ends of high-frequency isolation transformer T second former limit winding N2 is connected with the drain electrode of the 4th power switch tube S 4, the inverse parallel of second diode D2 and the 4th diode D4 difference is in the second power switch tube S 2 and the 4th power switch tube S 4 two ends, namely the negative electrode of the second diode D2 is connected with the drain electrode of the second power switch tube S 2, the anode of the second diode D2 is connected with the source electrode of the second power switch tube S 2, the negative electrode of the 4th diode D4 is connected with the drain electrode of the 4th power switch tube S 4, the anode of the 4th diode D4 is connected with the source electrode of the 4th power switch tube S 4, the source electrode of the second power switch tube S 2 is connected with the negative pole of the second input filter capacitor C2 with the source electrode of the 4th power switch tube S 4, the anode of the 5th diode D5 is connected with the positive pole of the second input filter capacitor C2 with the negative electrode of the 6th diode D6, the negative electrode of the 5th diode D5 connects the Same Name of Ends with high-frequency isolation transformer T first former limit winding N1, the anode of the 6th diode D6 connects and is connected with the Same Name of Ends of high-frequency isolation transformer T second former limit winding N2.Described frequency converter 4 is made up of the 5th power switch tube S 5, the 7th diode D7, the 6th power switch tube S 6, the 8th diode D8, the drain electrode of the 5th power switch tube S 5 is connected with the non-same polarity of high-frequency isolation transformer T first vice-side winding N3, 7th diode D7 inverse parallel is in the two ends of the 5th power switch tube S 5, namely the negative electrode of the 7th diode D7 is connected with the drain electrode of the 5th power switch tube S 5, the anode of the 7th diode D7 is connected with the source electrode of the 5th power switch tube S 5, the drain electrode of the 6th power switch tube S 6 is connected with the Same Name of Ends of high-frequency isolation transformer T first vice-side winding N3, 6th diode D6 inverse parallel is in the two ends of the 6th power switch tube S 6, namely the negative electrode of the 8th diode D8 is connected with the drain electrode of the 6th power switch tube S 6, the anode of the 8th diode D8 is connected with the source electrode of the 6th power switch tube S 6.Described output filter 5 comprises output filter capacitor Cf; The positive pole of output filter capacitor Cf is connected with the anode of the source electrode of the 5th power switch tube S 5, the 7th diode D7, and the negative pole of output filter capacitor Cf is connected with the anode of the source electrode of the 6th power switch tube S 6, the 8th diode D8.Described output AC load 6 comprises AC load ZL, and the positive pole of AC load ZL is connected with the positive pole of output filter capacitor Cf, and the negative pole of AC load ZL is connected with the negative pole of output filter capacitor Cf.

Half bridge flyback type high frequency isolation type three-level inverter topology as shown in Figure 4.Its physical circuit connects as follows: the input DC power 1 connected successively, input filter 2, half bridge flyback high-frequency isolation three level converter unit 3, frequency converter 4, output filter 5 and AC load 6 form the single switch flyback circuit topology being applicable to high input voltage DC-AC conversion occasion.Namely the positive pole of input DC power Ui is connected with the positive pole of the first input filter capacitor C1, and the negative pole of input DC power Ui is connected with the negative pole of the 4th input filter capacitor C4; Described input filter 2 is made up of the first input filter capacitor C1, the second input filter capacitor C2, the 3rd input filter capacitor C3 and the 4th input filter capacitor C4; The negative pole of the first input filter capacitor C1 is connected with the positive pole of the second input filter capacitor C2, the negative pole of the second input filter capacitor C2 is connected with the positive pole of the 3rd input filter capacitor C3, and the negative pole of the 3rd input filter capacitor C3 is connected with the positive pole of the 4th input filter capacitor C4.Described half bridge flyback high-frequency isolation three level converter unit 3 is by the first power switch tube S 1, first diode D1, second power switch tube S 2, second diode D2, 3rd diode D3, 4th diode D4, 3rd power switch tube S 3, 5th diode D5, 4th power switch tube S 4, 6th diode D6, 5th power switch tube S 5, 7th diode D7, 6th power switch tube S 6, 8th diode D8, high-frequency isolation transformer T first former limit winding N1, high-frequency isolation transformer T first vice-side winding N2 is formed, the drain electrode of the first power switch tube S 1 is connected with the positive pole of the first input filter capacitor C1, first diode D1 inverse parallel is in the first power switch tube S 1 two ends, namely the negative electrode of the first diode D1 is connected with the drain electrode of the first power switch tube S 1, the anode of the first diode D1 is connected with the source electrode of the first power switch tube S 1, the source electrode of the first power switch tube S 1 is connected with the source electrode of the 5th power switch tube S 5, the drain electrode of the 5th power switch tube S 5 is connected with the positive pole of the second input filter capacitor C2, 7th diode D7 inverse parallel is in the 5th power switch tube S 5 two ends, namely the negative electrode of the 7th diode D7 is connected with the drain electrode of the 5th power switch tube S 5, the anode of the 7th diode D7 is connected with the source electrode of the 5th power switch tube S 5, the drain electrode of the 3rd power switch tube S 3 and the source electrode of the first power switch tube S 1, the source electrode of the 5th power switch tube S 5 connects, 5th diode D5 inverse parallel is in the 3rd power switch tube S 3 two ends, namely the negative electrode of the 5th diode D5 is connected with the drain electrode of the 3rd power switch tube S 3, the anode of the 5th diode D5 is connected with the source electrode of the 3rd power switch tube S 3, the Same Name of Ends of high-frequency isolation transformer T first former limit winding N1 is connected with the source electrode of the 3rd power switch pipe, the negative electrode of the 3rd diode D3 and the source electrode of the first power switch tube S 1, the source electrode of the 5th power switch tube S 5, the drain electrode of the 3rd power switch tube S 3 is connected, the negative electrode of the 4th diode D4 and the negative pole of the second input filter capacitor C2, the positive pole of the 3rd input filter capacitor C3, the anode of the 3rd diode D3, the non-same polarity of high-frequency isolation transformer T first former limit winding N1 connects, the drain electrode of the 4th power switch tube S 4 is connected with the source electrode of the 3rd power switch tube S 3, 6th diode D6 inverse parallel is in the 4th power switch tube S 4 two ends, namely the negative electrode of the 6th diode D6 is connected with the drain electrode of the 4th power switch tube S 4, the anode of the 6th diode D6 is connected with the source electrode of the 4th power switch tube S 4, the source electrode of the 6th power switch tube S 6 and the negative pole of the 3rd input filter capacitor C3, the positive pole of the 4th input filter capacitor C4 is connected, the drain electrode of the 6th power switch tube S 6 and the anode of the 4th diode D4, the source electrode of the 4th power switch tube S 4 is connected, 8th diode D8 inverse parallel is in the 6th power switch tube S 6 two ends, namely the negative electrode of the 8th diode D8 is connected with the drain electrode of the 6th power switch tube S 6, the anode of the 8th diode D8 is connected with the source electrode of the 6th power switch tube S 6, the source electrode of the second power switch tube S 2 is connected with the negative pole of the 4th input filter capacitor C4, the drain electrode of the second power switch tube S 2 and the source electrode of the 4th power switch tube S 4, the drain electrode of the 6th power switch tube S 6, the anode of the 4th diode D4 is connected, second diode D2 inverse parallel is in the second power switch tube S 2 two ends, namely the negative electrode of the second diode D2 is connected with the drain electrode of the second power switch tube S 2, the anode of the second diode D2 is connected with the source electrode of the second power switch tube S 2.Described frequency converter 4 is made up of the 7th power switch tube S 7, the 9th diode D9, the 8th power switch tube S 8, the tenth diode D10, the drain electrode of the 7th power switch tube S 7 is connected with the non-same polarity of high-frequency isolation transformer T first vice-side winding N2, 9th diode D9 inverse parallel is in the two ends of the 7th power switch tube S 7, namely the negative electrode of the 9th diode D9 is connected with the drain electrode of the 7th power switch tube S 7, the anode of the 9th diode D9 is connected with the source electrode of the 7th power switch tube S 7, the drain electrode of the 8th power switch tube S 8 is connected with the Same Name of Ends of high-frequency isolation transformer T first vice-side winding N2, tenth diode D10 inverse parallel is in the two ends of the 8th power switch tube S 8, namely the negative electrode of the tenth diode D10 is connected with the drain electrode of the 8th power switch tube S 8, the anode of the tenth diode D10 is connected with the source electrode of the 8th power switch tube S 8.Described output filter 5 comprises output filter capacitor Cf; The positive pole of output filter capacitor Cf is connected with the anode of the source electrode of the 7th power switch tube S 7, the 9th diode D9, and the negative pole of output filter capacitor Cf is connected with the anode of the source electrode of the 8th power switch tube S 8, the tenth diode D10.Described output AC load 6 comprises AC load ZL, and the positive pole of AC load ZL is connected with the positive pole of output filter capacitor Cf, and the negative pole of AC load ZL is connected with the negative pole of output filter capacitor Cf.

Full-bridge flyback high frequency isolation type three-level inverter topology as shown in Figure 5.Its physical circuit connects as follows: the input DC power 1 connected successively, input filter 2, full-bridge flyback high-frequency isolation three level converter unit 3, frequency converter 4, output filter 5 and AC load 6 form the single switch flyback circuit topology being applicable to high input voltage DC-AC conversion occasion.Namely the positive pole of input DC power Ui is connected with the positive pole of the first input filter capacitor C1, and the negative pole of input DC power Ui is connected with the negative pole of the second input filter capacitor C2; Described input filter 2 is made up of the first input filter capacitor C1, the second input filter capacitor C2; The negative pole of the first input filter capacitor C1 is connected with the positive pole of the second input filter capacitor C2.Described full-bridge flyback high-frequency isolation three level converter unit 3 is by the first power switch tube S 1, first diode D1, second power switch tube S 2, second diode D2, 3rd power switch tube S 3, 3rd diode D3, 4th power switch tube S 4, 4th diode D4, 5th diode D5, 6th diode D6, 5th power switch tube S 5, 7th diode D7, 6th power switch tube S 6, 8th diode D8, 7th power switch tube S 7, 9th diode D9, 8th power switch tube S 8, tenth diode D10, 11 diode D11, is two diode D12, high-frequency isolation transformer T first former limit winding N1, high-frequency isolation transformer T first vice-side winding N2 is formed, the drain electrode of the first power switch tube S 1 is connected with the positive pole of the first input filter capacitor C1 with the drain electrode of the 5th power switch tube S 5, first diode D1 and the inverse parallel of the 7th diode difference are in the first power switch tube S 1 and the 5th power switch tube S 5 two ends, namely the negative electrode of the first diode D1 is connected with the drain electrode of the first power switch tube S 1, the anode of the first diode D1 is connected with the source electrode of the first power switch tube S 1, the negative electrode of the 7th diode D7 is connected with the drain electrode of the 5th power switch tube S 5, the anode of the 7th diode D7 is connected with the source electrode of the 5th power switch tube S 5, the drain electrode of the second power switch tube S 2 is connected with the source electrode of the first power switch tube S 1, second diode D2 inverse parallel is in the second power switch tube S 2 two ends, namely the negative electrode of the second diode D2 is connected with the drain electrode of the second power switch tube S 2, the anode of the second diode D2 is connected with the source electrode of the second power switch tube S 2, the drain electrode of the 3rd power switch tube S 3 is connected with the source electrode of the second power switch tube S 2, 3rd diode D3 inverse parallel is in the 3rd power switch tube S 3 two ends, namely the negative electrode of the 3rd diode D3 is connected with the drain electrode of the 3rd power switch tube S 3, the anode of the 3rd diode D3 is connected with the source electrode of the 3rd power switch tube S 3, the drain electrode of the 4th power switch tube S 4 is connected with the source electrode of the 3rd power switch tube S 3, 4th diode D4 inverse parallel is in the 4th power switch tube S 4 two ends, namely the negative electrode of the 4th diode D4 is connected with the drain electrode of the 4th power switch tube S 4, the anode of the 4th diode D4 is connected with the source electrode of the 4th power switch tube S 4, the source electrode of the 4th power switch tube S 4 is connected with the negative pole of the second input filter capacitor C2, the negative pole of the anode of the 5th diode D5 and the negative electrode of the 6th diode D6 and the first input filter capacitor C1, the positive pole of the second input filter capacitor C2 is connected, the negative electrode of the 5th diode D5 and the source electrode of the second power switch tube S 2, the drain electrode of the 3rd power switch tube S 3 is connected, the drain electrode of the 6th power switch tube S 6 is connected with the source electrode of the 5th power switch tube S 5, 8th diode D8 inverse parallel is in the 6th power switch tube S 6 two ends, namely the negative electrode of the 8th diode D8 is connected with the drain electrode of the 6th power switch tube S 6, the anode of the 8th diode D8 is connected with the source electrode of the 6th power switch tube S 6, the drain electrode of the 7th power switch tube S 7 is connected with the source electrode of the 6th power switch tube S 6, 9th diode D9 inverse parallel is in the 7th power switch tube S 7 two ends, namely the negative electrode of the 9th diode D9 is connected with the drain electrode of the 7th power switch tube S 7, the anode of the 9th diode D9 is connected with the source electrode of the 7th power switch tube S 7, the drain electrode of the 8th power switch tube S 8 is connected with the source electrode of the 7th power switch tube S 7, tenth diode D10 inverse parallel is in the 8th power switch tube S 8 two ends, namely the negative electrode of the tenth diode D10 is connected with the drain electrode of the 8th power switch tube S 8, the anode of the tenth diode D10 is connected with the source electrode of the 8th power switch tube S 8, the negative pole of the anode of the 11 diode D11 and the negative electrode of the 12 diode D12 and the first input filter capacitor C1, the positive pole of the second input filter capacitor C2, the anode of the 5th diode D5, the negative electrode of the 6th diode D6 is connected, the negative electrode of the 11 diode D11 and the source electrode of the 5th power switch tube S 5, the drain electrode of the 6th power switch tube S 6 is connected, the anode of the 12 diode D12 and the source electrode of the 7th power switch tube S 7, the drain electrode of the 8th power switch tube S 8 is connected, the source electrode of the 8th power switch tube S 8 and the negative pole of the second input filter capacitor C2, the source electrode of the 4th power switch tube S 4 is connected, the Same Name of Ends of high-frequency isolation transformer T first former limit winding N1 and the source electrode of the second power switch tube S 2, the drain electrode of the 3rd power switch tube S 3 is connected, the Same Name of Ends of high-frequency isolation transformer T first vice-side winding N2 and the source electrode of the 6th power switch tube S 6, the drain electrode of the 7th power switch tube S 7 is connected.Described frequency converter 4 is made up of the 9th power switch tube S the 9, the 13 diode D13, the tenth power switch tube S the 10, the 14 diode D14, the drain electrode of the 9th power switch tube S 9 is connected with the non-same polarity of high-frequency isolation transformer T first vice-side winding N2, 13 diode D13 inverse parallel is in the two ends of the 9th power switch tube S 9, namely the negative electrode of the 13 diode D13 is connected with the drain electrode of the 9th power switch tube S 9, the anode of the 13 diode D13 is connected with the source electrode of the 9th power switch tube S 9, the drain electrode of the tenth power switch tube S 10 is connected with the Same Name of Ends of high-frequency isolation transformer T first vice-side winding N2, 14 diode D14 inverse parallel is in the two ends of the tenth power switch tube S 10, namely the negative electrode of the 14 diode D14 is connected with the drain electrode of the tenth power switch tube S 10, the anode of the 14 diode D14 is connected with the source electrode of the tenth power switch tube S 10.Described output filter 5 comprises output filter capacitor Cf; The positive pole of output filter capacitor Cf is connected with the source electrode of the 9th power switch tube S 9, the anode of the 13 diode D13, and the negative pole of output filter capacitor Cf is connected with the source electrode of the tenth power switch tube S 10, the anode of the 14 diode D14.Described output AC load 6 comprises AC load ZL, and the positive pole of AC load ZL is connected with the positive pole of output filter capacitor Cf, and the negative pole of AC load ZL is connected with the negative pole of output filter capacitor Cf.

Claims (5)

1. a flyback high frequency isolation type three-level inverter, it is characterized in that: be made up of the input dc power source unit (1) connected successively, input filter (2), high frequency isolation type flyback three level converter unit (3), frequency converter (4), output filter (5) and AC load (6), wherein:

Input dc power source unit (1) is connected with input filter (2) one end, input filter (2) other end is connected with high frequency isolation type flyback three level converter unit (3) one end, high frequency isolation type flyback three level converter unit (3) other end is connected with frequency converter (4) one end through high frequency isolation type transformer (T), frequency converter (4) other end is connected with output filter (5) one end, and output filter (5) other end is connected with AC load (6).

2. a kind of flyback high frequency isolation type three-level inverter according to claims 1, it is characterized in that: the input DC power (1) connected successively, input filter (2), single switch flyback high-frequency isolation three level converter unit (3), high frequency isolation type transformer (T), full wave type frequency converter (4), output filter (5) and AC load (6) form the single switch flyback circuit topology being applicable to high input voltage DC-AC conversion occasion, wherein:

Described input filter (2) is made up of the first input filter capacitor (C1) and the second input filter capacitor (C2), the negative pole of the first input filter capacitor (C1) is connected with the positive pole of the second input filter capacitor (C2), the positive pole of input DC power (1) is connected with the positive pole of the first input filter capacitor (C1), and the negative pole of input DC power (1) is connected with the negative pole of the second input filter capacitor (C2);

Described single switch flyback high-frequency isolation three level converter unit (3) is made up of the first power switch pipe (S1), the second power switch pipe (S2), the first diode (D1), the second diode (D2), the 3rd diode (D3), high frequency isolation type transformer (T) first former limit winding (N1), high-frequency isolation transformer (T) first vice-side winding (N2), high-frequency isolation transformer (T) second vice-side winding (N3); the drain electrode of the first power switch pipe (S1) is connected with the positive pole of the first input filter capacitor (C1), first diode (D1) inverse parallel is in the two ends of the first power switch pipe (S1), namely the negative electrode of the first diode (D1) is connected with the drain electrode of the first power switch pipe (S1), the anode of the first diode (D1) is connected with the source electrode of the first power switch pipe (S1), the negative pole of the 3rd diode (D3) anode and the first input filter capacitor (C1), the positive pole of the second input filter capacitor (C2) is connected, the negative electrode of the 3rd diode (D3) is connected with the source electrode of the first power switch pipe (S1), the Same Name of Ends of high frequency isolation type transformer (T) first former limit winding (N1) and the source electrode of the first power switch pipe (S1), the negative electrode of the 3rd diode (D3) is connected, the drain electrode of the second power switch pipe (S2) is connected with the non-same polarity of high-frequency isolation transformer (T) first former limit winding (N1), second diode (D2) inverse parallel is in the two ends of the second power switch pipe (S2), namely the negative electrode of the second diode (D2) is connected with the drain electrode of the second power switch pipe (S2), the anode of the second diode (D2) is connected with the source electrode of the second power switch pipe (S2), the source electrode of the second power switch pipe (S2) is connected with the negative pole of the second input filter capacitor (C2), the Same Name of Ends of high-frequency isolation transformer (T) first vice-side winding (N2) is connected with the non-same polarity of high-frequency isolation transformer (T) second vice-side winding (N3),

Described full wave type frequency converter (4) is made up of the first two-way power switch pipe (SA) and the second two-way power switch pipe (SB), the first described two-way power switch pipe (SA) and the second two-way power switch pipe (SB) are all the switches for bearing forward, reverse voltage stress and current stress be made up of two single power switch pipe differential concatenations, have two-way blocking-up function, first two-way power switch pipe (SA) comprises the 3rd power switch pipe (S3), the 4th power switch pipe (S4), the 4th diode (D4), the 5th diode (D5), second two-way power switch pipe (SB) comprises the 5th power switch pipe (S5), the 6th power switch pipe (S6), the 6th diode (D6), the 7th diode (D7), one end of first two-way power switch pipe (SA) is connected with the non-same polarity of high-frequency isolation transformer (T) first vice-side winding (N2), one end of second two-way power switch pipe (SB) and the Same Name of Ends of high-frequency isolation transformer (T) second vice-side winding (N3) be connected, the other end of the second two-way power switch pipe (SB) is connected with the other end of the first two-way power switch pipe (SA), the drain electrode of the 3rd power switch pipe (S3) is connected as one end of the first two-way power switch pipe (SA) with the negative electrode of the 4th diode (D4), the drain electrode of the 4th power switch pipe (S4) is connected as the other end of the first two-way power switch pipe (SA) with the negative electrode of the 5th diode (D5), the source electrode of the 3rd power switch pipe (S3), the source electrode of the 4th power switch pipe (S4), the anode of the 4th diode (D4), the anode of the 5th diode (D5) links together, the drain electrode of the 5th power switch pipe (S5) is connected as one end of the second two-way power switch pipe (SB) with the negative electrode of the 6th diode (D6), the drain electrode of the 6th power switch pipe (S6) is connected as the other end of the second two-way power switch pipe (SB) with the negative electrode of the 7th diode (D7), the source electrode of the 5th power switch pipe (S5), the source electrode of the 6th power switch pipe (S6), the anode of the 6th diode (D6), the anode of the 7th diode (D7) links together,

Described output filter (5) comprises output filter capacitor (Cf); The negative electrode of the positive pole of output filter capacitor (Cf) and the drain electrode of the 4th power switch pipe (S4), the 5th diode (D5), the drain electrode of the 6th power switch pipe (S6), the negative electrode of the 7th diode (D7) are connected, and the negative pole of output filter capacitor (Cf) is connected with the non-same polarity of the Same Name of Ends of high-frequency isolation transformer (T) first vice-side winding (N2), high-frequency isolation transformer (T) second vice-side winding (N3);

Described output AC load (6) comprises AC load (ZL), the positive pole of AC load (ZL) is connected with the positive pole of output filter capacitor (Cf), and the negative pole of AC load (ZL) is connected with the negative pole of output filter capacitor (Cf).

3. the flyback high frequency isolation type three-level inverter according to claims 1, it is characterized in that: the input DC power (1) connected successively, input filter (2), double-transistor flyback high-frequency isolation three level converter unit (3), high frequency isolation type transformer (T), frequency converter (4), output filter (5) and AC load (6) form the single switch flyback circuit topology being applicable to high input voltage DC-AC conversion occasion, wherein:

Described input filter (2) is made up of the first input filter capacitor (C1) and the second input filter capacitor (C2); The negative pole of the first input filter capacitor (C1) is connected with the positive pole of the second input filter capacitor (C2); The positive pole of input DC power (1) is connected with the positive pole of the first input filter capacitor (C1), and the negative pole of input DC power (1) is connected with the negative pole of the second input filter capacitor (C2);

Described double-transistor flyback high-frequency isolation three level converter unit (3) is by the first power switch pipe (S1), first diode (D1), second power switch pipe (S2), second diode (D2), 3rd power switch pipe (S3), 3rd diode (D3), 4th power switch pipe (S4), 4th diode (D4), 5th diode (D5) the 6th diode (D6), high-frequency isolation transformer (T) first former limit winding (N1), high-frequency isolation transformer (T) second former limit winding (N2), high-frequency isolation transformer (T) first vice-side winding (N3) is formed, the drain electrode of the first power switch pipe (S1) is connected with the positive pole of the first input filter capacitor (C1) with the drain electrode of the 3rd power switch pipe (S3), first diode (D1) and the inverse parallel of the 3rd diode (D3) difference are in the first power switch pipe (S1) and the 3rd power switch pipe (S3) two ends, namely the negative electrode of the first diode (D1) is connected with the drain electrode of the first power switch pipe (S1), the anode of the first diode (D1) is connected with the source electrode of the first power switch pipe (S1), the negative electrode of the 3rd diode (D3) is connected with the drain electrode of the 3rd power switch pipe (S3), the anode of the 3rd diode (D3) is connected with the source electrode of the 3rd power switch pipe (S3), the source electrode of the first power switch pipe (S1) is connected with the Same Name of Ends of high-frequency isolation transformer (T) first former limit winding (N1), the source electrode of the 3rd power switch pipe (S3) is connected with the non-same polarity of high-frequency isolation transformer (T) second former limit winding (N2), the non-same polarity of high-frequency isolation transformer (T) first former limit winding (N1) is connected with the drain electrode of the second power switch pipe (S2), the Same Name of Ends of high-frequency isolation transformer (T) second former limit winding (N2) is connected with the drain electrode of the 4th power switch pipe (S4), second diode (D2) and the inverse parallel of the 4th diode (D4) difference are in the second power switch pipe (S2) and the 4th power switch pipe (S4) two ends, namely the negative electrode of the second diode (D2) is connected with the drain electrode of the second power switch pipe (S2), the anode of the second diode (D2) is connected with the source electrode of the second power switch pipe (S2), the negative electrode of the 4th diode (D4) is connected with the drain electrode of the 4th power switch pipe (S4), the anode of the 4th diode (D4) is connected with the source electrode of the 4th power switch pipe (S4), the source electrode of the second power switch pipe (S2) is connected with the negative pole of the second input filter capacitor (C2) with the source electrode of the 4th power switch pipe (S4), the anode of the 5th diode (D5) is connected with the positive pole of the second input filter capacitor (C2) with the negative electrode of the 6th diode (D6), the negative electrode of the 5th diode (D5) connects the Same Name of Ends with high-frequency isolation transformer (T) first former limit winding (N1), the anode of the 6th diode (D6) connects and is connected with the Same Name of Ends of high-frequency isolation transformer (T) second former limit winding (N2),

Described frequency converter (4) is made up of the 5th power switch pipe (S5), the 7th diode (D7), the 6th power switch pipe (S6), the 8th diode (D8), the drain electrode of the 5th power switch pipe (S5) is connected with the non-same polarity of high-frequency isolation transformer (T) first vice-side winding (N3), 7th diode (D7) inverse parallel is in the two ends of the 5th power switch pipe (S5), namely the negative electrode of the 7th diode (D7) is connected with the drain electrode of the 5th power switch pipe (S5), the anode of the 7th diode (D7) is connected with the source electrode of the 5th power switch pipe (S5), the drain electrode of the 6th power switch pipe (S6) is connected with the Same Name of Ends of high-frequency isolation transformer (T) first vice-side winding (N3), 6th diode (D6) inverse parallel is in the two ends of the 6th power switch pipe (S6), namely the negative electrode of the 8th diode (D8) is connected with the drain electrode of the 6th power switch pipe (S6), the anode of the 8th diode (D8) is connected with the source electrode of the 6th power switch pipe (S6),

Described output filter (5) comprises output filter capacitor (Cf); The positive pole of output filter capacitor (Cf) is connected with the anode of the source electrode of the 5th power switch pipe (S5), the 7th diode (D7), and the negative pole of output filter capacitor (Cf) is connected with the anode of the source electrode of the 6th power switch pipe (S6), the 8th diode (D8);

Described output AC load (6) comprises AC load (ZL), the positive pole of AC load (ZL) is connected with the positive pole of output filter capacitor (Cf), and the negative pole of AC load (ZL) is connected with the negative pole of output filter capacitor (Cf).

4. the flyback high frequency isolation type three-level inverter according to claims 1, it is characterized in that: the input DC power (1) connected successively, input filter (2), half bridge flyback high-frequency isolation three level converter unit (3), high-frequency isolation transformer (T), frequency converter (4), output filter (5) and AC load (6) form the single switch flyback circuit topology being applicable to high input voltage DC-AC conversion occasion, wherein:

Described input filter (2) is made up of the first input filter capacitor (C1), the second input filter capacitor (C2), the 3rd input filter capacitor (C3) and the 4th input filter capacitor (C4); The negative pole of the first input filter capacitor (C1) is connected with the positive pole of the second input filter capacitor (C2), the negative pole of the second input filter capacitor (C2) is connected with the positive pole of the 3rd input filter capacitor (C3), the negative pole of the 3rd input filter capacitor (C3) is connected with the positive pole of the 4th input filter capacitor (C4), the positive pole of input DC power (1) is connected with the positive pole of the first input filter capacitor (C1), and the negative pole of input DC power (1) is connected with the negative pole of the 4th input filter capacitor (C4);

Described half bridge flyback high-frequency isolation three level converter unit (3) is by the first power switch pipe (S1), first diode (D1), second power switch pipe (S2), second diode (D2), 3rd diode (D3), 4th diode (D4), 3rd power switch pipe (S3), 5th diode (D5), 4th power switch pipe (S4), 6th diode (D6), 5th power switch pipe (S5), 7th diode (D7), 6th power switch pipe (S6), 8th diode (D8), high-frequency isolation transformer (T) first former limit winding (N1), high-frequency isolation transformer (T) first vice-side winding (N2) is formed, the drain electrode of the first power switch pipe (S1) is connected with the positive pole of the first input filter capacitor (C1), first diode (D1) inverse parallel is in the first power switch pipe (S1) two ends, namely the negative electrode of the first diode (D1) is connected with the drain electrode of the first power switch pipe (S1), the anode of the first diode (D1) is connected with the source electrode of the first power switch pipe (S1), the source electrode of the first power switch pipe (S1) is connected with the source electrode of the 5th power switch pipe (S5), the drain electrode of the 5th power switch pipe (S5) is connected with the positive pole of the second input filter capacitor (C2), 7th diode (D7) inverse parallel is in the 5th power switch pipe (S5) two ends, namely the negative electrode of the 7th diode (D7) is connected with the drain electrode of the 5th power switch pipe (S5), the anode of the 7th diode (D7) is connected with the source electrode of the 5th power switch pipe (S5), the drain electrode of the 3rd power switch pipe (S3) and the source electrode of the first power switch pipe (S1), the source electrode of the 5th power switch pipe (S5) connects, 5th diode (D5) inverse parallel is in the 3rd power switch pipe (S3) two ends, namely the negative electrode of the 5th diode (D5) is connected with the drain electrode of the 3rd power switch pipe (S3), the anode of the 5th diode (D5) is connected with the source electrode of the 3rd power switch pipe (S3), the Same Name of Ends of high-frequency isolation transformer (T) first former limit winding (N1) is connected with the source electrode of the 3rd power switch pipe, the negative electrode of the 3rd diode (D3) and the source electrode of the first power switch pipe (S1), the source electrode of the 5th power switch pipe (S5), the drain electrode of the 3rd power switch pipe (S3) is connected, the negative electrode of the 4th diode (D4) and the negative pole of the second input filter capacitor (C2), the positive pole of the 3rd input filter capacitor (C3), the anode of the 3rd diode (D3), the non-same polarity of high-frequency isolation transformer (T) first former limit winding (N1) connects, the drain electrode of the 4th power switch pipe (S4) is connected with the source electrode of the 3rd power switch pipe (S3), 6th diode (D6) inverse parallel is in the 4th power switch pipe (S4) two ends, namely the negative electrode of the 6th diode (D6) is connected with the drain electrode of the 4th power switch pipe (S4), the anode of the 6th diode (D6) is connected with the source electrode of the 4th power switch pipe (S4), the source electrode of the 6th power switch pipe (S6) and the negative pole of the 3rd input filter capacitor (C3), the positive pole of the 4th input filter capacitor (C4) is connected, the drain electrode of the 6th power switch pipe (S6) and the anode of the 4th diode (D4), the source electrode of the 4th power switch pipe (S4) is connected, 8th diode (D8) inverse parallel is in the 6th power switch pipe (S6) two ends, namely the negative electrode of the 8th diode (D8) is connected with the drain electrode of the 6th power switch pipe (S6), the anode of the 8th diode (D8) is connected with the source electrode of the 6th power switch pipe (S6), the source electrode of the second power switch pipe (S2) is connected with the negative pole of the 4th input filter capacitor (C4), the drain electrode of the second power switch pipe (S2) and the source electrode of the 4th power switch pipe (S4), the drain electrode of the 6th power switch pipe (S6), the anode of the 4th diode (D4) is connected, second diode (D2) inverse parallel is in the second power switch pipe (S2) two ends, namely the negative electrode of the second diode (D2) is connected with the drain electrode of the second power switch pipe (S2), the anode of the second diode (D2) is connected with the source electrode of the second power switch pipe (S2),

Described frequency converter (4) is made up of the 7th power switch pipe (S7), the 9th diode (D9), the 8th power switch pipe (S8), the tenth diode (D10), the drain electrode of the 7th power switch pipe (S7) is connected with the non-same polarity of high-frequency isolation transformer (T) first vice-side winding (N2), 9th diode (D9) inverse parallel is in the two ends of the 7th power switch pipe (S7), namely the negative electrode of the 9th diode (D9) is connected with the drain electrode of the 7th power switch pipe (S7), the anode of the 9th diode (D9) is connected with the source electrode of the 7th power switch pipe (S7), the drain electrode of the 8th power switch pipe (S8) is connected with the Same Name of Ends of high-frequency isolation transformer (T) first vice-side winding (N2), tenth diode (D10) inverse parallel is in the two ends of the 8th power switch pipe (S8), namely the negative electrode of the tenth diode (D10) is connected with the drain electrode of the 8th power switch pipe (S8), the anode of the tenth diode (D10) is connected with the source electrode of the 8th power switch pipe (S8),

Described output filter (5) comprises output filter capacitor (Cf); The positive pole of output filter capacitor (Cf) is connected with the anode of the source electrode of the 7th power switch pipe (S7), the 9th diode (D9), and the negative pole of output filter capacitor (Cf) is connected with the anode of the source electrode of the 8th power switch pipe (S8), the tenth diode (D10);

Described output AC load (6) comprises AC load (ZL), the positive pole of AC load (ZL) is connected with the positive pole of output filter capacitor (Cf), and the negative pole of AC load (ZL) is connected with the negative pole of output filter capacitor (Cf).

5. the flyback high frequency isolation type three-level inverter according to claims 1, it is characterized in that: the input DC power (1) connected successively, input filter (2), full-bridge flyback high-frequency isolation three level converter unit (3), high-frequency isolation transformer (T), frequency converter (4), output filter (5) and AC load (6) form the single switch flyback circuit topology being applicable to high input voltage DC-AC conversion occasion, wherein:

Described input filter (2) is made up of the first input filter capacitor (C1), the second input filter capacitor (C2); The negative pole of the first input filter capacitor (C1) is connected with the positive pole of the second input filter capacitor (C2), the positive pole of input DC power (1) is connected with the positive pole of the first input filter capacitor (C1), and the negative pole of input DC power (1) is connected with the negative pole of the second input filter capacitor (C2);

Described full-bridge flyback high-frequency isolation three level converter unit (3) is by the first power switch pipe (S1), first diode (D1), second power switch pipe (S2), second diode (D2), 3rd power switch pipe (S3), 3rd diode (D3), 4th power switch pipe (S4), 4th diode (D4), 5th diode (D5), 6th diode (D6), 5th power switch pipe (S5), 7th diode (D7), 6th power switch pipe (S6), 8th diode (D8), 7th power switch pipe (S7), 9th diode (D9), 8th power switch pipe (S8), tenth diode (D10), 11 diode (D11), is two diodes (D12), high-frequency isolation transformer (T) first former limit winding (N1), high-frequency isolation transformer (T) first vice-side winding (N2) is formed, the drain electrode of the first power switch pipe (S1) is connected with the positive pole of the first input filter capacitor (C1) with the drain electrode of the 5th power switch pipe (S5), first diode (D1) and the inverse parallel of the 7th diode difference are in the first power switch pipe (S1) and the 5th power switch pipe (S5) two ends, namely the negative electrode of the first diode (D1) is connected with the drain electrode of the first power switch pipe (S1), the anode of the first diode (D1) is connected with the source electrode of the first power switch pipe (S1), the negative electrode of the 7th diode (D7) is connected with the drain electrode of the 5th power switch pipe (S5), the anode of the 7th diode (D7) is connected with the source electrode of the 5th power switch pipe (S5), the drain electrode of the second power switch pipe (S2) is connected with the source electrode of the first power switch pipe (S1), second diode (D2) inverse parallel is in the second power switch pipe (S2) two ends, namely the negative electrode of the second diode (D2) is connected with the drain electrode of the second power switch pipe (S2), the anode of the second diode (D2) is connected with the source electrode of the second power switch pipe (S2), the drain electrode of the 3rd power switch pipe (S3) is connected with the source electrode of the second power switch pipe (S2), 3rd diode (D3) inverse parallel is in the 3rd power switch pipe (S3) two ends, namely the negative electrode of the 3rd diode (D3) is connected with the drain electrode of the 3rd power switch pipe (S3), the anode of the 3rd diode (D3) is connected with the source electrode of the 3rd power switch pipe (S3), the drain electrode of the 4th power switch pipe (S4) is connected with the source electrode of the 3rd power switch pipe (S3), 4th diode (D4) inverse parallel is in the 4th power switch pipe (S4) two ends, namely the negative electrode of the 4th diode (D4) is connected with the drain electrode of the 4th power switch pipe (S4), the anode of the 4th diode (D4) is connected with the source electrode of the 4th power switch pipe (S4), the source electrode of the 4th power switch pipe (S4) is connected with the negative pole of the second input filter capacitor (C2), the anode of the 5th diode (D5) and the negative electrode of the 6th diode (D6) and the negative pole of the first input filter capacitor (C1), the positive pole of the second input filter capacitor (C2) is connected, the negative electrode of the 5th diode (D5) and the source electrode of the second power switch pipe (S2), the drain electrode of the 3rd power switch pipe (S3) is connected, the drain electrode of the 6th power switch pipe (S6) is connected with the source electrode of the 5th power switch pipe (S5), 8th diode (D8) inverse parallel is in the 6th power switch pipe (S6) two ends, namely the negative electrode of the 8th diode (D8) is connected with the drain electrode of the 6th power switch pipe (S6), the anode of the 8th diode (D8) is connected with the source electrode of the 6th power switch pipe (S6), the drain electrode of the 7th power switch pipe (S7) is connected with the source electrode of the 6th power switch pipe (S6), 9th diode (D9) inverse parallel is in the 7th power switch pipe (S7) two ends, namely the negative electrode of the 9th diode (D9) is connected with the drain electrode of the 7th power switch pipe (S7), the anode of the 9th diode (D9) is connected with the source electrode of the 7th power switch pipe (S7), the drain electrode of the 8th power switch pipe (S8) is connected with the source electrode of the 7th power switch pipe (S7), tenth diode (D10) inverse parallel is in the 8th power switch pipe (S8) two ends, namely the negative electrode of the tenth diode (D10) is connected with the drain electrode of the 8th power switch pipe (S8), the anode of the tenth diode (D10) is connected with the source electrode of the 8th power switch pipe (S8), the anode of the 11 diode (D11) and the negative electrode of the 12 diode (D12) and the negative pole of the first input filter capacitor (C1), the positive pole of the second input filter capacitor (C2), the anode of the 5th diode (D5), the negative electrode of the 6th diode (D6) is connected, the negative electrode of the 11 diode (D11) and the source electrode of the 5th power switch pipe (S5), the drain electrode of the 6th power switch pipe (S6) is connected, the anode of the 12 diode (D12) and the source electrode of the 7th power switch pipe (S7), the drain electrode of the 8th power switch pipe (S8) is connected, the source electrode of the 8th power switch pipe (S8) and the negative pole of the second input filter capacitor (C2), the source electrode of the 4th power switch pipe (S4) is connected, the Same Name of Ends of high-frequency isolation transformer (T) first former limit winding (N1) and the source electrode of the second power switch pipe (S2), the drain electrode of the 3rd power switch pipe (S3) is connected, the Same Name of Ends of high-frequency isolation transformer (T) first vice-side winding (N2) and the source electrode of the 6th power switch pipe (S6), the drain electrode of the 7th power switch pipe (S7) is connected,

Described frequency converter (4) is made up of the 9th power switch pipe (S9), the 13 diode (D13), the tenth power switch pipe (S10), the 14 diode (D14), the drain electrode of the 9th power switch pipe (S9) is connected with the non-same polarity of high-frequency isolation transformer (T) first vice-side winding (N2), 13 diode (D13) inverse parallel is in the two ends of the 9th power switch pipe (S9), namely the negative electrode of the 13 diode (D13) is connected with the drain electrode of the 9th power switch pipe (S9), the anode of the 13 diode (D13) is connected with the source electrode of the 9th power switch pipe (S9), the drain electrode of the tenth power switch pipe (S10) is connected with the Same Name of Ends of high-frequency isolation transformer (T) first vice-side winding (N2), 14 diode (D14) inverse parallel is in the two ends of the tenth power switch pipe (S10), namely the negative electrode of the 14 diode (D14) is connected with the drain electrode of the tenth power switch pipe (S10), the anode of the 14 diode (D14) is connected with the source electrode of the tenth power switch pipe (S10),

Described output filter (5) comprises output filter capacitor (Cf); The positive pole of output filter capacitor (Cf) is connected with the source electrode of the 9th power switch pipe (S9), the anode of the 13 diode (D13), and the negative pole of output filter capacitor (Cf) is connected with the source electrode of the tenth power switch pipe (S10), the anode of the 14 diode (D14);

Described output AC load (6) comprises AC load (ZL), the positive pole of AC load (ZL) is connected with the positive pole of output filter capacitor (Cf), and the negative pole of AC load (ZL) is connected with the negative pole of output filter capacitor (Cf).