Current type high-gain DC-DC converter

Abstract

The utility model provides a current type high-gain DC-DC converter, which comprises a DC source uin, a current type full-bridge converter, a three-winding transformer T, two auxiliary capacitors CP1 and CP2, two auxiliary diodes DP1 and DP2 and 2n expansion units. According to the utility model, the output voltage of the circuit can be effectively improved, and the defects caused by the adoption of a high transformer turn ratio for realizing large voltage gain are avoided. The current type full-bridge converter is adopted in the front stage, continuous input current can be achieved, the converter is more friendly to an input source, different numbers of expansion units can be adopted according to specific application occasions, high boosting of the converter is achieved, the voltage gain is adjustable, different boosting requirements are met, and the applicability of the circuit is effectively expanded.

Description

Technical Field

[0001] The utility model relates to a power electronic converter, in particular to a current type high-gain DC-DC converter. Background Art

[0002] At present, photovoltaic power generation and energy storage batteries are widely used in the power industry. However, since the DC power output voltage level of the above-mentioned new energy power generation methods is low and the grid-connected voltage is high, the voltage gain of the traditional DC-DC converter is difficult to meet the high voltage boost demand. Therefore, a high-gain DC-DC converter is required to convert the low voltage of the new energy power source into the high voltage required for grid connection.

[0003] In order to improve the voltage gain, for example, the patent with application publication number CN111884521A discloses a single-stage Boost full-bridge boost zero-current switching DC converter and its control method. The primary side of the converter consists of a boost inductor, an LC series resonant cavity and a full-bridge module, wherein the two switch tubes of the lagging bridge arm of the full-bridge module are respectively connected in series with a diode in the forward direction to prevent the current from flowing in the reverse direction, and the secondary side is a voltage doubler rectifier circuit, and the primary and secondary sides are connected through a high-frequency transformer. The converter adopts fixed-frequency phase-shift PWM control. The two switch tube drives of the leading bridge arm have the same duty cycle greater than 0.5, and the phase difference is half a switching cycle. The two switch tube drive duty cycles of the lagging bridge arm are both 0.5, and the phase difference is half a switching cycle. There is a phase shift angle between the switch tube drives on the diagonal lines of the two bridge arms, and the driving duty cycle of the leading bridge arm satisfies a fixed relationship with the phase shift angle. By controlling the phase shift angle, the transmission power and the boost ratio can be adjusted. The utility model can realize zero-current switching on and off of all semiconductor devices. However, the converter design is complex and requires precise calculation of the device parameters in the resonant cavity. At the same time, its structure is not scalable and the voltage gain is relatively fixed, making it difficult to adapt to high voltage boost requirements in different scenarios. Utility Model Content

[0004] In order to solve the technical problems of low voltage gain, insufficient voltage boosting capability and small adjustable range of voltage gain of traditional DC-DC converters, the utility model proposes a current-type high-gain DC-DC converter, which can effectively improve the voltage gain under the condition of continuous input current and has multi-level gain adjustment capability.

[0005] The technical solution adopted by the utility model is:

[0006] A current-type high-gain DC-DC converter, characterized in that: the converter comprises a DC source u in , a current-mode full-bridge converter, a three-winding transformer T, and two auxiliary capacitors C P1 , C P2 , 2 auxiliary diodes DP1 , D P2 , 2n expansion units, n is a natural number, and the value range is n≥1;

[0007] The current-mode full-bridge converter includes capacitor C in , 2 inductors L 1 , L 2 , 4 switches S 1 , S 2 , S 3 , S 4 , the primary winding T of transformer T P ; Its connection form is as follows:

[0008] DC source u in The upper end of the first inductor L is connected 1 and the second inductor L 2 The left end of the first inductor L 1 The right end is connected to the first switch S 1 The source of the third switch S 3 The drain of the three-winding transformer T and the primary winding T P A terminal; the second inductor L 2 The right end is connected to the second switch S 2 The source of the fourth switch S 4 The drain of the three-winding transformer T and the primary winding T P The B terminal of the first switch S 1 The drain of the second switch S 2 The drain and capacitor C in The upper end of the third switch S 3 The source of the fourth switch S 4 The source, capacitor C in The lower end and DC source u in The lower end; 4 switches S 1 , S 2 , S 3 , S 4 The gates of the switches S 1 , the fourth switch S 4 Synchronous control, the second switch S 2 , the third switch S 3 Synchronous control, the duty cycle is kept at 0.5, and the conduction is alternately operated;

[0009] The three-winding transformer T includes the primary winding T P , secondary winding T S1 and the secondary winding T S2 , the first auxiliary capacitor C P1 The left end is connected to the secondary winding T of the three-winding transformer T S1The D terminal, the first auxiliary capacitor C P1 The right end is connected to the first auxiliary diode D P1 The anode of the first auxiliary diode D P1 The cathode of the three-winding transformer T is connected to the secondary winding T S1 The second auxiliary capacitor C P2 The left end is connected to the secondary winding T of the three-winding transformer T S2 The D` terminal, the second auxiliary capacitor C P2 The right end is connected to the second auxiliary diode D P2 The anode of the second auxiliary diode D P2 The cathode of the three-winding transformer T is connected to the secondary winding T S2 The C` end;

[0010] Each expansion unit has the same structure, including a left capacitor, a right capacitor, an upper diode, and a lower diode. The connection form is as follows:

[0011] When n=1, the left capacitor C of the first expansion unit 12 The left end is connected to the secondary winding C of the three-winding transformer T, and the left capacitor C 12 The right end of the upper diode D 11 The anode and lower side of diode D 12 The cathode connection of the lower diode D 12 The anode of the three-winding transformer T is connected to the secondary winding D, and the capacitor C on the right is connected to the secondary winding D of the three-winding transformer T. 11 The upper end of the upper diode D 11 The cathode connection of the right capacitor C 11 The lower end of the diode D 12 The anode of the second expansion unit is connected to form the first expansion unit; the capacitor C on the left side of the second expansion unit 22 The left end is connected to the secondary winding C' end of the three-winding transformer T, and the left capacitor C 22 The right end of the upper diode D 21 The anode and lower side of diode D 22 The cathode connection of the lower diode D 22 The anode of the three-winding transformer T is connected to the secondary winding D' end, and the capacitor C on the right is connected to the secondary winding D' end of the three-winding transformer T. 21 The upper end of the upper diode D 21 The cathode connection of the right capacitor C 21 The lower end of the diode D 22 The anode of is connected to form the second expansion unit;

[0012] When n>1, among the 2n expansion units, the 2n-1th expansion unit contains the left capacitor C (2n-1)2 、The right capacitor C (2n-1)1, upper diode D (2n-1)1 , lower diode D (2n-1)2 ; Among them, the left capacitor C of the 2n-1th expansion unit (2n-1)2 The left end is connected to the secondary winding C of the three-winding transformer T, and the left capacitor C (2n-1)2 The right end of the upper diode D (2n-1)1 The anode and lower side of diode D (2n-1)2 The cathode connection of the lower diode D (2n-1)2 The anode of the 2n-3rd expansion unit is connected to the upper side diode D (2n-3)1 The cathode connection of the right capacitor C (2n-1)1 The upper end of the upper diode D (2n-1)1 The cathode connection of the right capacitor C (2n-1)1 The lower end of the diode D (2n-1)2 Anode connection;

[0013] When n>1, among the 2n expansion units, the 2nth expansion unit contains the left capacitor C (2n)2 、The right capacitor C (2n)1 , upper diode D (2n)1 , lower diode D (2n)2 ; Among them, the left capacitor C of the 2nth expansion unit (2n)2 The left end is connected to the secondary winding C' end of the three-winding transformer T, and the left capacitor C (2n)2 The right end of the upper diode D (2n)1 The anode and lower side of diode D (2n)2 The cathode connection of the lower diode D (2n)2 The anode of the second (n-1) expansion unit and the upper side diode D 2(n-1)1 The cathode connection of the right capacitor C (2n)1 The upper end of the upper diode D (2n)1 The cathode and the first auxiliary capacitor C P1 The right end is connected to the capacitor C (2n)1 The lower end of the diode D (2n)2 Anode connection;

[0014] The two ends of the load R are connected to the capacitor C in the 2n-1th expansion unit. (2n-1)1 The upper end and the second auxiliary capacitor C P2 The right end is connected.

[0015] When four expansion units are used, the first switch S 1 , the fourth switch S 4 When conducting, the upper diode D of the first expansion unit 11 , the second expansion unit upper side diode D 21 , the third expansion unit upper side diode D 31, the upper diode D of the 4th expansion unit 41 The first auxiliary diode D is turned on. P1 , the second auxiliary diode D P2 and the diode D on the lower side of the first expansion unit 12 , the second expansion unit lower side diode D 22 , the diode D on the lower side of the third expansion unit 32 , the fourth expansion unit lower side diode D 42 Shutdown, the first auxiliary capacitor C P1 , the second auxiliary capacitor C P2 and the right capacitor C of the first expansion unit 11 , the right capacitor C of the second expansion unit 21 , the right capacitor C of the third expansion unit 31 , the right capacitor C of the fourth expansion unit 41 Charging, AC input source s The left capacitor C of the first expansion unit 12 , the left capacitor C of the second expansion unit 22 , the left capacitor C of the third expansion unit 32 , the left capacitor C of the 4th expansion unit 42 The discharge provides power to the load.

[0016] When four expansion units are used, the second switch S 2 , the third switch S 3 The diode D on the upper side of the first expansion unit is turned on. 11 , the second expansion unit upper side diode D 21 , the third expansion unit upper side diode D 31 , the upper diode D of the 4th expansion unit 41 Shut down, the diode D on the lower side of the first expansion unit 12 , the second expansion unit lower side diode D 22 , the diode D on the lower side of the third expansion unit 32 , the diode on the lower side of the fourth expansion unit is turned on, and the AC input source u s With the first auxiliary capacitor C P1 , the second auxiliary capacitor C P2 and the right capacitor C of the first expansion unit 11 , the right capacitor C of the second expansion unit 21 , the right capacitor C of the third expansion unit 31 , the right capacitor C of the fourth expansion unit 41 Discharge to supply power to the load, the left capacitor C of the first expansion unit 12 , the left capacitor C of the second expansion unit 22, the left capacitor C of the third expansion unit 32 , the left capacitor C of the 4th expansion unit 42 Charge.

[0017] The output voltage of the current-type high-gain DC-DC converter of the utility model is adjusted by adjusting the number of expansion units to achieve high-gain multi-stage voltage regulation capability. Each expansion unit can increase the voltage gain by 2, and the input and output voltage gain of the rectifier circuit is N. 1 (2n+1)+N 2 (2n+1). Where N 1 The secondary winding T of the three-winding transformer S1 With the primary winding T P Turns ratio, N 2 The secondary winding T of the three-winding transformer S2 With the primary winding T P Turns ratio.

[0018] The utility model is a current-type high-gain DC-DC converter, and the technical effects are as follows:

[0019] 1) It can effectively improve the output voltage of the circuit and avoid the disadvantages of using a high transformer turns ratio to achieve a larger voltage gain.

[0020] 2) The use of a current-type full-bridge converter in the front stage can achieve continuous input current and is more friendly to the input source.

[0021] 3) The utility model can adopt different numbers of expansion units according to specific application scenarios to achieve high voltage boost of the converter, and the voltage gain is adjustable, thereby meeting different voltage boost requirements and effectively expanding the applicability of the circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The utility model is further described below in conjunction with the accompanying drawings and embodiments:

[0023] Figure 1 It is a specific circuit principle diagram of the utility model containing 4 expansion units.

[0024] Figure 2 This is a specific circuit schematic diagram containing n expansion units mentioned in the utility model.

[0025] Figure 3 The utility model contains 4 expansion units under the input voltage of 100V, N 1 =N 2 =1 when the input and output voltage simulation diagram. DETAILED DESCRIPTION

[0026] Figure 1The current-type high-gain DC-DC converter shown in FIG. includes a DC source u in , a current-mode full-bridge converter, a three-winding transformer T, and two auxiliary capacitors C P1 , C P2 , 2 auxiliary diodes D P1 , D P2 , 4 expansion units;

[0027] The current-mode full-bridge converter includes capacitor C in , 2 inductors L 1 , L 2 , 4 switches S 1 , S 2 , S 3 , S 4 , the primary winding T of transformer T P ; Its connection form is as follows:

[0028] DC source u in The upper end of the inductor L is connected 1 and L 2 The left end of the inductor L 1 The right end of the switch S 1 The source and switch S 3 The drain of the three-winding transformer T P A terminal; inductor L 2 The right end of the switch S 2 The source and switch S 4 The drain of the three-winding transformer T P The B terminal of the switch S 1 The drain of the switch S 2 The drain and capacitor C in The upper end of switch S 3 The source of the switch S 4 The source, capacitor C in The lower end and DC source u in The lower end of switch S 1 , S 2 , S 3 , S 4 The gates of the switches S 1 , S 4 Synchronous control, switch S 2 , S 3 Synchronous control, the duty cycle is kept at 0.5, and the operation is alternately turned on.

[0029] The three-winding transformer T includes the primary winding T P , secondary winding T S1 and the secondary winding T S2 , the first auxiliary capacitor CP1 The left end is connected to the secondary winding T of the three-winding transformer T S1 The D terminal, the first auxiliary capacitor C P1 The right end is connected to the first auxiliary diode D P1 The anode of the first auxiliary diode D P1 The cathode of the three-winding transformer T is connected to the secondary winding T S1 The second auxiliary capacitor C P2 The left end is connected to the secondary winding T of the three-winding transformer T S2 The D` terminal, the second auxiliary capacitor C P2 The right end is connected to the second auxiliary diode D P2 The anode of the second auxiliary diode D P2 The cathode of the three-winding transformer T is connected to the secondary winding T S2 The C` end.

[0030] The first expansion unit contains the left capacitor C 12 、The right capacitor C 11 , upper diode D 11 , lower diode D 12 ; Among them, the capacitor C on the left side of the first expansion unit 12 The left end is connected to the secondary winding C of the three-winding transformer T, and the left capacitor C 12 The right end of the upper diode D 11 The anode and lower side of diode D 12 The cathode connection of the lower diode D 12 The anode of the three-winding transformer T is connected to the secondary winding D, and the capacitor C on the right is connected to the secondary winding D of the three-winding transformer T. 11 The upper end of the upper diode D 11 The cathode connection of the right capacitor C 11 The lower end of the diode D 12 The anode of is connected to form the first expansion unit;

[0031] The second expansion unit contains the left capacitor C 22 、The right capacitor C 21 , upper diode D 21 , lower diode D 22 ; Among them, the capacitor C on the left side of the second expansion unit 22 The left end is connected to the secondary winding C' end of the three-winding transformer T, and the left capacitor C 22 The right end of the upper diode D 21 The anode and lower side of diode D 22 The cathode connection of the lower diode D 22 The anode of the three-winding transformer T is connected to the secondary winding D' end, and the capacitor C on the right is connected to the secondary winding D' end of the three-winding transformer T. 21 The upper end of the upper diode D21 The cathode connection of the right capacitor C 21 The lower end of the diode D 22 The anode of is connected to form the second expansion unit;

[0032] The third expansion unit contains the left capacitor C 32 、The right capacitor C 31 , upper diode D 31 , lower diode D 32 ; Among them, the capacitor C on the left side of the third expansion unit 32 The left end is connected to the secondary winding C of the three-winding transformer T, and the left capacitor C 32 The right end of the upper diode D 31 The anode and lower side of diode D 32 The cathode connection of the lower diode D 32 The anode of the first expansion unit is connected to the upper side diode D 11 The cathode connection of the right capacitor C 11 The lower end of the diode D 12 The anode of is connected to form the third expansion unit;

[0033] The fourth expansion unit contains the left capacitor C 42 、The right capacitor C 41 , upper diode D 41 , lower diode D 42 ; Among them, the capacitor C on the left side of the 4th expansion unit 42 The left end is connected to the secondary winding C' end of the three-winding transformer T, and the left capacitor C 42 The right end of the upper diode D 41 The anode and lower side of diode D 42 The cathode connection of the lower diode D 42 The anode of the second expansion unit is connected to the upper side diode D 21 The cathode connection of the right capacitor C 41 The upper end of the upper diode D 41 The cathode and the first auxiliary capacitor C P1 The right end is connected to the capacitor C 41 The lower end of the diode D 42 The anode of is connected to form the fourth expansion unit;

[0034] The two ends of the load R are connected to the capacitor C in the third expansion unit. 31 The upper end and the second auxiliary capacitor C P2 The right end is connected.

[0035] When the switch S 1 , S 4 Conducting, diode D11 , D 21 , D 31 , D 41 Conducting, diode D P1 , D P2 and diode D 12 , D 22 , D 32 , D 42 Shutdown, auxiliary capacitor C P1 , C P2 and the first expansion unit capacitor C 11 , the second expansion unit capacitor C 21 , the third expansion unit capacitor C 31 , the fourth expansion unit capacitor C 41 Charging, AC input source s With the first expansion unit capacitor C 12 , the second expansion unit capacitor C 22 , the third expansion unit capacitor C 32 , the fourth expansion unit capacitor C 42 The discharge provides power to the load.

[0036] When the switch S 2 , S 3 Conducting, diode D 11 , D 21 , D 31 , D 41 Turn off, diode D P1 , D P2 and diode D 12 , D 22 , D 32 , D 42 Conduction, AC input source u s With auxiliary capacitor C P1 , C P2 and the first expansion unit capacitor C 11 , the second expansion unit capacitor C 21 , the third expansion unit capacitor C 31 , the fourth expansion unit capacitor C 41 Discharge to supply power to the load, the first expansion unit capacitor C 12 , the second expansion unit capacitor C 22 , the third expansion unit capacitor C 32 , the fourth expansion unit capacitor C 42 Charge.

[0037] Figure 2 The current-type high-gain DC-DC converter shown in FIG. includes a DC source u in , a current-mode full-bridge converter, a three-winding transformer T, and two auxiliary capacitors CP1 , C P2 , 2 auxiliary diodes D P1 , D P2 , 2n expansion units, n is a natural number, and the value range is n≥1.

[0038] The current-mode full-bridge converter includes capacitor C in , inductance L 1 , L 2 , switch S 1 , S 2 , S 3 , S 4 , the primary winding T of transformer T P ; Its connection form is as follows:

[0039] DC source u in The upper end of the inductor L is connected 1 and L 2 The left end of the inductor L 1 The right end of the switch S 1 The source and switch S 3 The drain of the three-winding transformer T P A terminal; inductor L 2 The right end of the switch S 2 The source and switch S 4 The drain of the three-winding transformer T P The B terminal of the switch S 1 The drain of the switch S 2 The drain and capacitor C in The upper end of switch S 3 The source of the switch S 4 The source, capacitor C in The lower end and DC source u in The lower end of switch S 1 , S 2 , S 3 , S 4 The gates of the switches S 1 , S 4 Synchronous control, switch S 2 , S 3 Synchronous control, the duty cycle is kept at 0.5, and the conduction is alternately operated;

[0040] The three-winding transformer T includes the primary winding T P , secondary winding T S1 and the secondary winding T S2 , the first auxiliary capacitor C P1 The left end is connected to the secondary winding T of the three-winding transformer T S1 The D terminal, the first auxiliary capacitor CP1 The right end is connected to the first auxiliary diode D P1 The anode of the first auxiliary diode D P1 The cathode of the three-winding transformer T is connected to the secondary winding T S1 The second auxiliary capacitor C P2 The left end is connected to the secondary winding T of the three-winding transformer T S2 The D` terminal, the second auxiliary capacitor C P2 The right end is connected to the second auxiliary diode D P2 The anode of the second auxiliary diode D P2 The cathode of the three-winding transformer T is connected to the secondary winding T S2 The C` end.

[0041] Each expansion unit has the same structure, including a left capacitor, a right capacitor, an upper diode, and a lower diode. The connection form is as follows:

[0042] The first expansion unit contains the left capacitor C 12 、The right capacitor C 11 , upper diode D 11 , lower diode D 12 ; Among them, the capacitor C on the left side of the first expansion unit 12 The left end is connected to the secondary winding C of the three-winding transformer T, and the left capacitor C 12 The right end of the upper diode D 11 The anode and lower side of diode D 12 The cathode connection of the lower diode D 12 The anode of the three-winding transformer T is connected to the secondary winding D, and the capacitor C on the right is connected to the secondary winding D of the three-winding transformer T. 11 The upper end of the upper diode D 11 The cathode connection of the right capacitor C 11 The lower end of the diode D 12 The anode of is connected to form the first expansion unit;

[0043] The second expansion unit contains the left capacitor C 22 、The right capacitor C 21 , upper diode D 21 , lower diode D 22 ; Among them, the capacitor C on the left side of the second expansion unit 22 The left end is connected to the secondary winding C' end of the three-winding transformer T, and the left capacitor C 22 The right end of the upper diode D 21 The anode and lower side of diode D 22 The cathode connection of the lower diode D 22 The anode of the three-winding transformer T is connected to the secondary winding D' end, and the capacitor C on the right is connected to the secondary winding D' end of the three-winding transformer T.21 The upper end of the upper diode D 21 The cathode connection of the right capacitor C 21 The lower end of the diode D 22 The anode of is connected to form the second expansion unit;

[0044] When n>1, among the 2n expansion units, the 2n-1th expansion unit contains the left capacitor C (2n-1)2 、The right capacitor C (2n-1)1 , upper diode D (2n-1)1 , lower diode D (2n-1)2 ; Among them, the left capacitor C of the 2n-1th expansion unit (2n-1)2 The left end is connected to the secondary winding C of the three-winding transformer T, and the left capacitor C (2n-1)2 The right end of the upper diode D (2n-1)1 The anode and lower side of diode D (2n-1)2 The cathode connection of the lower diode D (2n-1)2 The anode of the 2n-3rd expansion unit is connected to the upper side diode D (2n-3)1 The cathode connection of the right capacitor C (2n-1)1 The upper end of the upper diode D (2n-1)1 The cathode connection of the right capacitor C (2n-1)1 The lower end of the diode D (2n-1)2 Anode connection;

[0045] When n>1, among the 2n expansion units, the 2nth expansion unit contains the left capacitor C (2n)2 、The right capacitor C (2n)1 , upper diode D (2n)1 , lower diode D (2n)2 ; Among them, the left capacitor C of the 2nth expansion unit (2n)2 The left end is connected to the secondary winding C' end of the three-winding transformer T, and the left capacitor C (2n)2 The right end of the upper diode D (2n)1 The anode and lower side of diode D (2n)2 The cathode connection of the lower diode D (2n)2 The anode of the second (n-1) expansion unit and the upper side diode D 2(n-1)1 The cathode connection of the right capacitor C (2n)1 The upper end of the upper diode D (2n)1 The cathode and the first auxiliary capacitor C P1 The right end is connected to the capacitor C (2n)1 The lower end of the diode D (2n)2 The two ends of the load R are connected to the anode of the capacitor C in the 2n-1th expansion unit. (2n-1)1 The upper end and the second auxiliary capacitor C P2The right end is connected.

[0046] The output voltage of the current-type high-gain DC-DC converter of the utility model is adjusted by adjusting the number of expansion units to achieve high-gain multi-stage voltage regulation capability. Each expansion unit can increase the voltage gain by 2, and the input and output voltage gain of the rectifier circuit is N. 1 (2n+1)+N 2 (2n+1). Where N 1 The secondary winding T of the three-winding transformer S1 With the primary winding T P Turns ratio, N 2 The secondary winding T of the three-winding transformer S2 With the primary winding T P Turns ratio.

[0047] Depend on Figure 3 It can be seen that the proposed expansion unit contains 4 units when the input voltage is 100V, N 1 =N 2 When =1, the output voltage is 1000V, achieving a 10-fold voltage gain, effectively improving the voltage gain of the circuit.

[0048] The above description is only a specific embodiment of the present invention, but the structural features of the present invention are not limited thereto. Any changes or modifications made by any technician in the field of the present invention are included in the protection scope of the present invention.

[0049] It should be noted that the terms "including" and "having" and any variations thereof in the specification and claims of the utility model and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "installed", "set", "provided with", "connected", "connected", and "socketed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be an internal connection between two devices, elements or components. For those of ordinary skill in the art, the specific meanings of the above terms in the utility model can be understood according to the specific circumstances.

[0050] In the description of the present invention, it should be understood that the terms "one end", "the other end", "outside", "inside", "horizontal", "end", "length", "left", "right", "upper", "lower", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. The terms "first", "second", "third", "fourth", "1st", "2nd", "3rd", "4th" are also used only for the sake of brevity in the description, and do not indicate or imply relative importance.

Claims

1. A current-type high-gain DC-DC converter, characterized in that: The converter consists of a DC source u in , a current-mode full-bridge converter, a three-winding transformer T, and two auxiliary capacitors C P1 , C P2 , 2 auxiliary diodes D P1 , D P2 , 2n expansion units, n is a natural number, and the value range is n≥1; The current-mode full-bridge converter includes capacitor C in , 2 inductors L1, L2, 4 switches S1, S2, S3, S4, the primary winding T of the transformer T P ; Its connection form is as follows: DC source in The upper end of the first inductor L1 and the left end of the second inductor L2 are connected, and the right end of the first inductor L1 is connected to the source of the first switch S1, the drain of the third switch S3 and the primary winding T of the three-winding transformer T. P The right end of the second inductor L2 is connected to the source of the second switch S2 and the drain of the fourth switch S4 and the primary winding T of the three-winding transformer T P The drain of the first switch S1 is connected to the drain of the second switch S2 and the capacitor C in The source of the third switch S3 is connected to the source of the fourth switch S4, the capacitor C in The lower end and DC source u in The gates of the four switches S1, S2, S3, and S4 are connected to their respective controllers, the first switch S1 and the fourth switch S4 are synchronously controlled, the second switch S2 and the third switch S3 are synchronously controlled, the duty cycle is maintained at 0.5, and they are turned on alternately; The three-winding transformer T includes the primary winding T P , secondary winding T S1 and the secondary winding T S2 , the first auxiliary capacitor C P1 The left end is connected to the secondary winding T of the three-winding transformer T S1 The D terminal, the first auxiliary capacitor C P1 The right end is connected to the first auxiliary diode D P1 The anode of the first auxiliary diode D P1 The cathode of the three-winding transformer T is connected to the secondary winding T S1 The second auxiliary capacitor C P2 The left end is connected to the secondary winding T of the three-winding transformer T S2 The D` terminal, the second auxiliary capacitor C P2 The right end is connected to the second auxiliary diode D P2 The anode of the second auxiliary diode D P2 The cathode of the three-winding transformer T is connected to the secondary winding T S2 The C` end; Each expansion unit has the same structure, including a left capacitor, a right capacitor, an upper diode, and a lower diode. The connection form is as follows: When n=1, the left capacitor C of the first expansion unit 12 The left end is connected to the secondary winding C of the three-winding transformer T, and the left capacitor C 12 The right end of the upper diode D 11 The anode and lower side of diode D 12 The cathode connection of the lower diode D 12 The anode of the three-winding transformer T is connected to the secondary winding D, and the capacitor C on the right is connected to the secondary winding D of the three-winding transformer T. 11 The upper end of the upper diode D 11 The cathode connection of the right capacitor C 11 The lower end of the diode D 12 The anode of the second expansion unit is connected to form the first expansion unit; the capacitor C on the left side of the second expansion unit 22 The left end is connected to the secondary winding C' end of the three-winding transformer T, and the left capacitor C 22 The right end of the upper diode D 21 The anode and lower side of diode D 22 The cathode connection of the lower diode D 22 The anode of the three-winding transformer T is connected to the secondary winding D' end, and the capacitor C on the right is connected to the secondary winding D' end of the three-winding transformer T. 21 The upper end of the upper diode D 21 The cathode connection of the right capacitor C 21 The lower end of the diode D 22 The anode of is connected to form the second expansion unit; When n>1, among the 2n expansion units, the 2n-1th expansion unit contains the left capacitor C (2n-1)2 、The right capacitor C (2n-1)1 , upper diode D (2n-1)1 , lower diode D (2n-1)2 ; Among them, the left capacitor C of the 2n-1th expansion unit (2n-1)2 The left end is connected to the secondary winding C of the three-winding transformer T, and the left capacitor C (2n-1)2 The right end of the upper diode D (2n-1)1 The anode and lower side of diode D (2n-1)2 The cathode connection of the lower diode D (2n-1)2 The anode of the 2n-3rd expansion unit is connected to the upper side diode D (2n-3)1 The cathode connection of the right capacitor C (2n-1)1 The upper end of the upper diode D (2n-1)1 The cathode connection of the right capacitor C (2n-1)1 The lower end of the diode D (2n-1)2 Anode connection; When n>1, among the 2n expansion units, the 2nth expansion unit contains the left capacitor C (2n)2 、The right capacitor C (2n)1 , upper diode D (2n)1 , lower diode D (2n)2 ; Among them, the left capacitor C of the 2nth expansion unit (2n)2 The left end is connected to the secondary winding C' end of the three-winding transformer T, and the left capacitor C (2n)2 The right end of the upper diode D (2n)1 The anode and lower side of diode D (2n)2 The cathode connection of the lower diode D (2n)2 The anode of the second (n-1) expansion unit and the upper side diode D 2(n-1)1 The cathode connection of the right capacitor C (2n)1 The upper end of the upper diode D (2n)1 The cathode and the first auxiliary capacitor C P1 The right end is connected to the capacitor C (2n)1 The lower end of the diode D (2n)2 Anode connection; The two ends of the load R are connected to the capacitor C in the 2n-1th expansion unit. (2n-1)1 The upper end and the second auxiliary capacitor C P2 The right end is connected.

2. A current-type high-gain DC-DC converter according to claim 1, characterized in that: When four expansion units are used, when the first switch S1 and the fourth switch S4 are turned on, the upper diode D of the first expansion unit 11 , the second expansion unit upper side diode D 21 , the third expansion unit upper side diode D 31 , the upper diode D of the 4th expansion unit 41 The first auxiliary diode D is turned on. P1 , the second auxiliary diode D P2 and the diode D on the lower side of the first expansion unit 12 , the second expansion unit lower side diode D 22 , the diode D on the lower side of the third expansion unit 32 , the fourth expansion unit lower side diode D 42 Shutdown, the first auxiliary capacitor C P1 , the second auxiliary capacitor C P2 and the right capacitor C of the first expansion unit 11 , the right capacitor C of the second expansion unit 21 , the right capacitor C of the third expansion unit 31 , the right capacitor C of the fourth expansion unit 41 Charging, AC input source s The left capacitor C of the first expansion unit 12 , the left capacitor C of the second expansion unit 22 , the left capacitor C of the third expansion unit 32 , the left capacitor C of the 4th expansion unit 42 The discharge provides power to the load.

3. A current-type high-gain DC-DC converter according to claim 1, characterized in that: When four expansion units are used, the second switch S2 and the third switch S3 are turned on, and the upper diode D of the first expansion unit is 11 , the second expansion unit upper side diode D 21 , the third expansion unit upper side diode D 31 , the upper diode D of the 4th expansion unit 41 Shut down, the diode D on the lower side of the first expansion unit 12 , the second expansion unit lower side diode D 22 , the diode D on the lower side of the third expansion unit 32 , the diode on the lower side of the fourth expansion unit is turned on, and the AC input source u s With the first auxiliary capacitor C P1 , the second auxiliary capacitor C P2 and the right capacitor C of the first expansion unit 11 , the right capacitor C of the second expansion unit 21 , the right capacitor C of the third expansion unit 31 , the right capacitor C of the fourth expansion unit 41 Discharge to supply power to the load, the left capacitor C of the first expansion unit 12 , the left capacitor C of the second expansion unit 22 , the left capacitor C of the third expansion unit 32 , the left capacitor C of the 4th expansion unit 42 Charge.

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