Absorption circuit and phase-shifted full-bridge circuit

Abstract

The utility model provides an absorption circuit and a phase-shifted full-bridge circuit. The absorption circuit is applied to the phase-shifted full-bridge circuit. The first input end of the phase-shifted full-bridge circuit is used for being connected with a positive bus, the second input end of the phase-shifted full-bridge circuit is used for being connected with a negative bus, and the output end of the phase-shifted full-bridge circuit is used for supplying power to a load; the phase-shifted full-bridge circuit comprises a transformer; the first end of the absorption circuit is connected with the primary winding of the transformer, the second end of the absorption circuit is connected with the positive bus, and the third end of the absorption circuit is connected with the negative bus; and the absorption circuit is used for feeding back the absorbed energy to the positive bus and the negative bus. The absorption circuit is only arranged on the primary side of the transformer, the absorption circuit does not need to be arranged on each rectifier diode on the secondary side, the size of the phase-shifted full-bridge circuit can be reduced, the absorption circuit can feed back the absorbed energy to the positive bus and the negative bus instead of directly converting the energy into heat to be consumed, and the energy consumption is reduced. Energy waste can be avoided, and the efficiency of the circuit is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of energy absorption, and in particular relates to an absorption circuit and a phase-shifted full-bridge circuit. Background Art

[0002] The phase-shifted full-bridge circuit includes a primary full-bridge module, a transformer, and a secondary rectifier module. The secondary rectifier circuit includes multiple rectifier diodes. When the anode potential of the rectifier diode is negative relative to the cathode potential, there may be a reverse peak voltage. In order to prevent the rectifier diode from being broken down by the reverse peak voltage, an absorption circuit is usually set to absorb the energy of the reverse peak voltage.

[0003] At present, an absorption circuit is usually connected in parallel to each rectifier diode to absorb the energy of the reverse peak voltage. However, this method will cause the size of the phase-shifted full-bridge circuit to be too large, and the absorption circuit will convert all the energy of the reverse peak voltage into heat and consume it, resulting in energy waste. Utility Model Content

[0004] In view of this, an embodiment of the utility model provides an absorption circuit and a phase-shifted full-bridge circuit to solve the problem that the existing absorption circuit causes the phase-shifted full-bridge circuit to be too large, and the absorption circuit converts all the energy of the reverse peak voltage into heat and consumes it, causing energy waste.

[0005] The first aspect of the embodiment of the utility model provides an absorption circuit, which is applied to a phase-shifted full-bridge circuit; the first input end of the phase-shifted full-bridge circuit is used to connect to the positive bus, the second input end of the phase-shifted full-bridge circuit is used to connect to the negative bus, and the output end of the phase-shifted full-bridge circuit is used to supply power to the load; the phase-shifted full-bridge circuit includes a transformer;

[0006] The first end of the absorption circuit is connected to the primary winding of the transformer, the second end of the absorption circuit is connected to the positive bus, and the third end of the absorption circuit is connected to the negative bus; the absorption circuit is used to feed back the absorbed energy to the positive bus and the negative bus.

[0007] In some possible implementations, the absorption circuit includes a first diode, a second diode, a first capacitor, and a first resistor;

[0008] The first resistor and the first capacitor are connected in parallel; the first end of the first resistor and the first capacitor after being connected in parallel is connected to the first end of the absorption circuit, and the second end of the first resistor and the first capacitor after being connected in parallel is respectively connected to the anode of the first diode and the cathode of the second diode; the cathode of the first diode is connected to the second end of the absorption circuit, and the anode of the second diode is connected to the third end of the absorption circuit.

[0009] In some possible implementations, the absorption circuit includes a first absorption unit and a second absorption unit;

[0010] The first end of the first absorption unit is connected to the first end of the absorption circuit, and the second end of the first absorption unit is connected to the second end of the absorption circuit;

[0011] The first end of the second absorption unit is connected to the first end of the absorption circuit, and the second end of the second absorption unit is connected to the third end of the absorption circuit.

[0012] In some possible implementations, the first absorption unit includes a second resistor, a second capacitor, and a third diode;

[0013] The second resistor and the second capacitor are connected in parallel; the first end of the second resistor and the second capacitor after being connected in parallel is connected to the first end of the first absorption unit, the second end of the second resistor and the second capacitor after being connected in parallel is connected to the anode of the third diode, and the cathode of the third diode is connected to the second end of the first absorption unit.

[0014] In some possible implementations, the second absorption unit includes a third resistor, a third capacitor, and a fourth diode;

[0015] The third resistor and the third capacitor are connected in parallel; the first end of the third resistor and the third capacitor after being connected in parallel is connected to the first end of the second absorption unit, the second end of the third resistor and the third capacitor after being connected in parallel is connected to the cathode of the fourth diode, and the anode of the fourth diode is connected to the second end of the second absorption unit.

[0016] In some possible implementations, the first end of the absorption circuit includes a first connection end and a second connection end; the first connection end is connected to the first end of the primary winding of the transformer, and the second connection end is connected to the second end of the primary winding of the transformer;

[0017] The absorption circuit includes a third absorption unit and a fourth absorption unit;

[0018] A first end of the third absorption unit is connected to the first connection end, and a second end of the third absorption unit is connected to the second end of the absorption circuit;

[0019] The first end of the fourth absorption unit is connected to the second connection end, and the second end of the fourth absorption unit is connected to the third end of the absorption circuit.

[0020] In some possible implementations, the third absorption unit includes a fourth resistor, a fourth capacitor, and a fifth diode;

[0021] The fourth resistor and the fourth capacitor are connected in parallel; the first end of the fourth resistor and the fourth capacitor after being connected in parallel is connected to the first end of the third absorption unit, the second end of the fourth resistor and the fourth capacitor after being connected in parallel is connected to the anode of the fifth diode, and the cathode of the fifth diode is connected to the second end of the third absorption unit.

[0022] In some possible implementations, the fourth absorption unit includes a fifth resistor, a fifth capacitor, and a sixth diode;

[0023] The fifth resistor and the fifth capacitor are connected in parallel; the first end of the fifth resistor and the fifth capacitor after being connected in parallel is connected to the first end of the fourth absorption unit, the second end of the fifth resistor and the fifth capacitor after being connected in parallel is connected to the cathode of the sixth diode, and the anode of the sixth diode is connected to the second end of the fourth absorption unit.

[0024] In some possible implementations, the phase-shifted full-bridge circuit further includes a primary full-bridge module and a secondary rectifier module;

[0025] The first input end of the primary full-bridge module is connected to the first input end of the phase-shifted full-bridge circuit, the second input end of the primary full-bridge module is connected to the second input end of the phase-shifted full-bridge circuit, and the output end of the primary full-bridge module is connected to the primary winding of the transformer; the secondary winding of the transformer is connected to the input end of the secondary rectifier module, and the output end of the secondary rectifier module is connected to the output end of the phase-shifted full-bridge circuit.

[0026] A second aspect of an embodiment of the utility model provides a phase-shifted full-bridge circuit, comprising an absorption circuit as described in the first aspect or any possible implementation of the first aspect.

[0027] The absorption circuit provided in this embodiment is applied to a phase-shifted full-bridge circuit. The first end of the absorption circuit is connected to the primary winding of the phase-shifted full-bridge circuit transformer, the second end of the absorption circuit is connected to the positive bus, and the third end of the absorption circuit is connected to the negative bus. In this embodiment, the absorption circuit is only arranged on the primary side of the transformer, and there is no need to arrange the absorption circuit on each rectifier diode on the secondary side. The volume of the phase-shifted full-bridge circuit can be reduced, and the absorption circuit can feed back the absorbed energy to the positive bus and the negative bus instead of directly converting the energy into heat for consumption, which can avoid energy waste and improve the efficiency of the circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0029] Figure 1 This is a schematic diagram of the structure of the absorption circuit provided by the embodiment of the utility model Figure 1 ;

[0030] Figure 2 This is a schematic diagram of the structure of the absorption circuit provided by the embodiment of the utility model Figure 2 ;

[0031] Figure 3 This is a schematic diagram of the structure of the absorption circuit provided by the embodiment of the utility model Figure 3 ;

[0032] Figure 4 This is a schematic diagram of the structure of the absorption circuit provided by the embodiment of the utility model Figure 4 . DETAILED DESCRIPTION

[0033] In the following description, specific details such as specific system structures and technologies are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention can also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid unnecessary details that hinder the description of the present invention.

[0034] In order to illustrate the technical solution of the present utility model, specific embodiments are provided below for illustration.

[0035] See also Figure 1 The embodiment of the utility model provides an absorption circuit 10, which is applied to a phase-shifted full-bridge circuit; the first input end of the phase-shifted full-bridge circuit is used to connect to the positive bus U+, the second input end of the phase-shifted full-bridge circuit is used to connect to the negative bus U-, and the output end of the phase-shifted full-bridge circuit is used to supply power to the load RL; the phase-shifted full-bridge circuit includes a transformer Tr;

[0036] The first end of the absorption circuit 10 is connected to the primary winding of the transformer Tr, the second end of the absorption circuit 10 is connected to the positive bus U+, and the third end of the absorption circuit 10 is connected to the negative bus U-; the absorption circuit 10 is used to feed back the absorbed energy to the positive bus U+ and the negative bus U-.

[0037] In some embodiments, see Figure 1 , the phase-shifted full-bridge circuit also includes a primary full-bridge module 20 and a secondary rectifier module 30;

[0038] The first input end of the primary full-bridge module 20 is connected to the first input end of the phase-shifted full-bridge circuit, the second input end of the primary full-bridge module 20 is connected to the second input end of the phase-shifted full-bridge circuit, and the output end of the primary full-bridge module 20 is connected to the primary winding of the transformer Tr; the secondary winding of the transformer Tr is connected to the input end of the secondary rectifier module 30, and the output end of the secondary rectifier module 30 is connected to the output end of the phase-shifted full-bridge circuit.

[0039] See also Figure 1The primary full-bridge module 20 includes a first switch tube Q1, a second switch tube Q2, a third switch tube Q3, a fourth switch tube Q4, a resonant inductor Lr and a resonant capacitor Cr. The first switch tube Q1 includes a first body diode D1 and a first parasitic junction capacitor C1; the second switch tube Q2 includes a second body diode D2 and a second parasitic junction capacitor C2; the third switch tube Q3 includes a third body diode D3 and a third parasitic junction capacitor C3; the fourth switch tube Q4 includes a fourth body diode D4 and a fourth parasitic junction capacitor C4.

[0040] The secondary rectifier module 30 includes a first rectifier diode DR1 , a second rectifier diode DR2 , a third rectifier diode DR3 , a fourth rectifier diode DR4 , a filter inductor Lf and a filter capacitor Cf.

[0041] The connection relationship between the components in the primary full-bridge module 20 and the secondary rectifier module 30 is shown in Figure 1 , I will not go into details here.

[0042] In this embodiment, the phase-shifted full-bridge circuit includes four rectifier diodes. When the anode potential of each rectifier diode is negative relative to the cathode potential, a reverse peak voltage may exist. The reverse peak voltage can be mapped to the primary side of the transformer Tr through the transformer Tr. The absorption circuit 10 set on the primary side of the transformer Tr can absorb the energy of the reverse peak voltage and feed the absorbed energy back to the positive bus U+ and the negative bus U-, thereby avoiding energy waste and improving circuit efficiency.

[0043] The absorption circuit 10 provided in this embodiment is applied to a phase-shifted full-bridge circuit. The first end of the absorption circuit 10 is connected to the primary winding of the phase-shifted full-bridge circuit transformer Tr, the second end of the absorption circuit 10 is connected to the positive bus U+, and the third end of the absorption circuit 10 is connected to the negative bus U-. In this embodiment, the absorption circuit 10 is only arranged on the primary side of the transformer Tr, and there is no need to arrange the absorption circuit on each rectifier diode on the secondary side, which can reduce the volume of the phase-shifted full-bridge circuit, and the absorption circuit 10 can feed back the absorbed energy to the positive bus U+ and the negative bus U-, instead of directly converting the energy into heat for consumption, which can avoid energy waste and improve the efficiency of the circuit.

[0044] In some embodiments, see Figure 2 , the absorption circuit 10 includes a first diode DS1, a second diode DS2, a first capacitor CS1 and a first resistor RS1;

[0045] The first resistor RS1 and the first capacitor CS1 are connected in parallel; the first end of the first resistor RS1 and the first capacitor CS1 after being connected in parallel is connected to the first end of the absorption circuit 10, and the second end of the first resistor RS1 and the first capacitor CS1 after being connected in parallel is respectively connected to the anode of the first diode DS1 and the cathode of the second diode DS2; the cathode of the first diode DS1 is connected to the second end of the absorption circuit 10, and the anode of the second diode DS2 is connected to the third end of the absorption circuit 10.

[0046] In this embodiment, the first end of the absorption circuit 10 is connected to the first end of the primary winding of the transformer Tr. The first capacitor CS1 may be a single capacitor or a plurality of capacitors connected in parallel or in series.

[0047] See also Figure 2 When the reverse peak voltage is mapped to the voltage of the primary side of the transformer Tr as positive, the first diode DS1 is turned on; when the reverse peak voltage is mapped to the voltage of the primary side of the transformer Tr as negative, the second diode DS2 is turned on.

[0048] The absorption circuit 10 provided in this embodiment can feed back the energy of the reverse peak voltage of the rectifier diode to the busbar, thereby improving the circuit efficiency. Compared with the solution of providing an absorption circuit at each rectifier diode, this embodiment can reduce the volume of the phase-shifted full-bridge circuit.

[0049] In some embodiments, see Figure 3 , the absorption circuit 10 includes a first absorption unit 11 and a second absorption unit 12;

[0050] A first end of the first absorption unit 11 is connected to a first end of the absorption circuit 10, and a second end of the first absorption unit 11 is connected to a second end of the absorption circuit 10;

[0051] A first end of the second absorption unit 12 is connected to a first end of the absorption circuit 10 , and a second end of the second absorption unit 12 is connected to a third end of the absorption circuit 10 .

[0052] In some embodiments, see Figure 3 , the first absorption unit 11 includes a second resistor RS2, a second capacitor CS2 and a third diode DS3;

[0053] The second resistor RS2 and the second capacitor CS2 are connected in parallel; the first end of the second resistor RS2 and the second capacitor CS2 after being connected in parallel is connected to the first end of the first absorption unit 11, the second end of the second resistor RS2 and the second capacitor CS2 after being connected in parallel is connected to the anode of the third diode DS3, and the cathode of the third diode DS3 is connected to the second end of the first absorption unit 11.

[0054] In some embodiments, see Figure 3, the second absorption unit 12 includes a third resistor RS3, a third capacitor CS3 and a fourth diode DS4;

[0055] The third resistor RS3 and the third capacitor CS3 are connected in parallel; the first end of the third resistor RS3 and the third capacitor CS3 after being connected in parallel is connected to the first end of the second absorption unit 12, the second end of the third resistor RS3 and the third capacitor CS3 after being connected in parallel is connected to the cathode of the fourth diode DS4, and the anode of the fourth diode DS4 is connected to the second end of the second absorption unit 12.

[0056] In this embodiment, a first end of the absorption circuit 10 is connected to a first end of the primary winding of the transformer Tr.

[0057] Figure 3 The snubber circuit scheme shown will Figure 2 The snubber circuit shown is split, Figure 2 Compared with the solution of setting a snubber circuit at each rectifier diode, the snubber circuit shown in the figure can reduce the volume, but Figure 2 The first capacitor CS1 in the absorption circuit shown needs to withstand bidirectional ripple current, so the temperature rise is high and the volume of the first capacitor CS1 is relatively large. Figure 3 In the absorption circuit shown, under the same working conditions, the second capacitor CS2 and the third capacitor CS3 only bear unidirectional ripple current, have a small temperature rise, and a small volume, which can further reduce the volume of the entire phase-shifted full-bridge circuit.

[0058] In some embodiments, see Figure 4 , the first end of the absorption circuit 10 includes a first connection end J1 and a second connection end J2; the first connection end J1 is connected to the first end of the primary winding of the transformer Tr, and the second connection end J2 is connected to the second end of the primary winding of the transformer Tr;

[0059] The absorption circuit 10 includes a third absorption unit 13 and a fourth absorption unit 14;

[0060] A first end of the third absorption unit 13 is connected to the first connection end J1, and a second end of the third absorption unit 13 is connected to the second end of the absorption circuit 10;

[0061] A first end of the fourth absorption unit 14 is connected to the second connection end J2 , and a second end of the fourth absorption unit 14 is connected to the third end of the absorption circuit 10 .

[0062] In some embodiments, see Figure 4 , the third absorption unit 13 includes a fourth resistor RS4, a fourth capacitor CS4 and a fifth diode DS5;

[0063] The fourth resistor RS4 and the fourth capacitor CS4 are connected in parallel; the first end of the fourth resistor RS4 and the fourth capacitor CS4 after being connected in parallel is connected to the first end of the third absorption unit 13, the second end of the fourth resistor RS4 and the fourth capacitor CS4 after being connected in parallel is connected to the anode of the fifth diode DS5, and the cathode of the fifth diode DS5 is connected to the second end of the third absorption unit 13.

[0064] In some embodiments, see Figure 4 , the fourth absorption unit 14 includes a fifth resistor RS5, a fifth capacitor CS5 and a sixth diode DS6;

[0065] The fifth resistor RS5 and the fifth capacitor CS5 are connected in parallel; the first end of the fifth resistor RS5 and the fifth capacitor CS5 after being connected in parallel is connected to the first end of the fourth absorption unit 14, the second end of the fifth resistor RS5 and the fifth capacitor CS5 after being connected in parallel is connected to the cathode of the sixth diode DS6, and the anode of the sixth diode DS6 is connected to the second end of the fourth absorption unit 14.

[0066] Figure 4 The snubber circuit scheme shown is similar to Figure 3 The absorption circuit shown is similar. Under the same working conditions, the fourth capacitor CS4 and the fifth capacitor CS5 only bear unidirectional ripple current, have a small temperature rise, and a small volume, which can further reduce the volume of the entire phase-shifted full-bridge circuit.

[0067] Corresponding to the above absorption circuit, see Figures 1 to 4 An embodiment of the utility model provides a phase-shifted full-bridge circuit, including any of the above absorption circuits, and having the beneficial effects of any of the above absorption circuits.

[0068] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope of the present invention.

Claims

1. An absorption circuit, characterized in that: Applied to a phase-shifted full-bridge circuit; the first input end of the phase-shifted full-bridge circuit is used to be connected to a positive bus, the second input end of the phase-shifted full-bridge circuit is used to be connected to a negative bus, and the output end of the phase-shifted full-bridge circuit is used to supply power to a load; the phase-shifted full-bridge circuit includes a transformer; The first end of the absorption circuit is connected to the primary winding of the transformer, the second end of the absorption circuit is connected to the positive bus, and the third end of the absorption circuit is connected to the negative bus; the absorption circuit is used to feed back the absorbed energy to the positive bus and the negative bus.

2. The absorption circuit according to claim 1, characterized in that: The absorption circuit includes a first diode, a second diode, a first capacitor and a first resistor; The first resistor and the first capacitor are connected in parallel; the first end of the first resistor and the first capacitor after being connected in parallel is connected to the first end of the absorption circuit, and the second end of the first resistor and the first capacitor after being connected in parallel is respectively connected to the anode of the first diode and the cathode of the second diode; the cathode of the first diode is connected to the second end of the absorption circuit, and the anode of the second diode is connected to the third end of the absorption circuit.

3. The absorption circuit according to claim 1, characterized in that: The absorption circuit includes a first absorption unit and a second absorption unit; The first end of the first absorption unit is connected to the first end of the absorption circuit, and the second end of the first absorption unit is connected to the second end of the absorption circuit; The first end of the second absorption unit is connected to the first end of the absorption circuit, and the second end of the second absorption unit is connected to the third end of the absorption circuit.

4. The absorption circuit according to claim 3, characterized in that: The first absorption unit includes a second resistor, a second capacitor and a third diode; The second resistor and the second capacitor are connected in parallel; the first end of the second resistor and the second capacitor connected in parallel is connected to the first end of the first absorption unit, the second end of the second resistor and the second capacitor connected in parallel is connected to the anode of the third diode, and the cathode of the third diode is connected to the second end of the first absorption unit.

5. The absorption circuit according to claim 3, characterized in that: The second absorption unit includes a third resistor, a third capacitor and a fourth diode; The third resistor and the third capacitor are connected in parallel; the first end of the third resistor and the third capacitor after being connected in parallel is connected to the first end of the second absorption unit, the second end of the third resistor and the third capacitor after being connected in parallel is connected to the cathode of the fourth diode, and the anode of the fourth diode is connected to the second end of the second absorption unit.

6. The absorption circuit according to claim 1, characterized in that: The first end of the absorption circuit includes a first connection end and a second connection end; the first connection end is connected to the first end of the primary winding of the transformer, and the second connection end is connected to the second end of the primary winding of the transformer; The absorption circuit includes a third absorption unit and a fourth absorption unit; The first end of the third absorption unit is connected to the first connection end, and the second end of the third absorption unit is connected to the second end of the absorption circuit; The first end of the fourth absorption unit is connected to the second connection end, and the second end of the fourth absorption unit is connected to the third end of the absorption circuit.

7. The absorption circuit according to claim 6, characterized in that: The third absorption unit includes a fourth resistor, a fourth capacitor and a fifth diode; The fourth resistor and the fourth capacitor are connected in parallel; the first end of the fourth resistor and the fourth capacitor after being connected in parallel is connected to the first end of the third absorption unit, the second end of the fourth resistor and the fourth capacitor after being connected in parallel is connected to the anode of the fifth diode, and the cathode of the fifth diode is connected to the second end of the third absorption unit.

8. The absorption circuit according to claim 6, characterized in that: The fourth absorption unit includes a fifth resistor, a fifth capacitor and a sixth diode; The fifth resistor and the fifth capacitor are connected in parallel; the first end of the fifth resistor and the fifth capacitor after being connected in parallel is connected to the first end of the fourth absorption unit, the second end of the fifth resistor and the fifth capacitor after being connected in parallel is connected to the cathode of the sixth diode, and the anode of the sixth diode is connected to the second end of the fourth absorption unit.

9. The absorption circuit according to any one of claims 1 to 8, characterized in that: The phase-shifted full-bridge circuit also includes a primary full-bridge module and a secondary rectifier module; The first input end of the primary full-bridge module is connected to the first input end of the phase-shift full-bridge circuit, the second input end of the primary full-bridge module is connected to the second input end of the phase-shift full-bridge circuit, and the output end of the primary full-bridge module is connected to the primary winding of the transformer; the secondary winding of the transformer is connected to the input end of the secondary rectifier module, and the output end of the secondary rectifier module is connected to the output end of the phase-shift full-bridge circuit.

10. A phase-shifted full-bridge circuit, characterized in that: The invention comprises the absorption circuit as claimed in any one of claims 1 to 9.

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