CN116317510A

CN116317510A - Leakage inductance absorption circuit, power supply system and electronic device

Info

Publication number: CN116317510A
Application number: CN202310203483.4A
Authority: CN
Inventors: 请求不公布姓名
Original assignee: Ensai Semiconductor Chengdu Co ltd
Current assignee: Ensai Semiconductor Chengdu Co ltd
Priority date: 2022-12-20
Filing date: 2023-03-04
Publication date: 2023-06-23

Abstract

The invention discloses a leakage inductance absorption circuit, a power supply system and an electronic device, wherein the leakage inductance absorption circuit is applied to the power supply system comprising a first transformer and comprises: the energy transmission module is configured to transmit leakage inductance energy of the first transformer; the energy buffer module is configured to buffer and store leakage inductance energy of the first transformer; the energy transfer module is configured to transfer leakage inductance energy cached in the energy cache module; the energy storage module is configured to store and utilize leakage inductance energy transferred by the energy transfer module; the leakage inductance absorption circuit recovers and utilizes the leakage inductance energy of the first transformer, improves the conversion efficiency of the first transformer, and solves the problem of transformer efficiency reduction caused by the conventional RCD absorption circuit.

Description

Leakage inductance absorption circuit, power supply system and electronic device

Technical Field

The invention relates to the technical field of power supply conversion, in particular to a leakage inductance absorption circuit, a power supply system and an electronic device.

Background

The current mainstream isolated power conversion circuit basically adopts flyback architecture (flyback), as shown in fig. 1a, the input VIN and the output VOUT of the power supply are isolated by a transformer. Since the transformer T1 used in the flyback converter has non-ideal characteristics, it is difficult to avoid the existence of the leakage inductance Lk, which can cause the leakage inductance Lk to resonate with the parasitic capacitance Coss of the switching node SW to generate very high-frequency oscillation when the flyback converter is in switching operation, resulting in a very high oscillation voltage spike of the switching node SW, as shown in fig. 1 b. To ensure the reliability of the power switch MP, an RCD snubber circuit is generally used to absorb the oscillating voltage spike caused by the leakage inductance Lk of the transformer T1. In a conventional RCD snubber circuit, energy in leakage inductance Lk is transferred to the snubber capacitor Clp, resulting in a cycle-by-cycle accumulation of energy on the capacitor Clp, and a cycle-by-cycle increase in voltage on the capacitor Clp, thereby simultaneously discharging the excess energy to the capacitor Clp in parallel with the bleeder resistor Rlp. But this results in additional energy loss on the bleeder resistor Rlp, resulting in a reduced conversion efficiency of the transformer T1.

Therefore, the loss caused by leakage inductance Lk is reduced, the conversion efficiency of the transformer T1 is improved, and the method has very practical significance.

Disclosure of Invention

The embodiment of the invention provides a leakage inductance absorption circuit applied to a power supply system, which is used for reducing the loss problem caused by leakage inductance of a transformer in an electronic device and improving the conversion efficiency of the transformer and the power supply system.

In a first aspect, an embodiment of the present invention provides a leakage inductance absorption circuit, which is applied to a power supply system including a first transformer, and includes:

an energy transfer module configured to transfer leakage inductance energy of the first transformer;

an energy buffer module configured to buffer store leakage inductance energy of the first transformer;

the energy transfer module is configured to transfer leakage inductance energy buffered in the energy buffer module;

an energy storage module configured to store and utilize leakage inductance energy transferred by the energy transfer module; the leakage inductance absorption circuit recovers and utilizes the leakage inductance energy of the first transformer, and improves the conversion efficiency of the first transformer.

Preferably, the energy transfer module is coupled to the first primary winding of the first transformer and comprises a first diode.

Preferably, the energy buffer module is coupled in series in a loop formed by the energy transfer module and the first primary winding of the first transformer, including the absorption capacitance.

Preferably, the energy storage module comprises a storage capacitor.

Preferably, the energy storage module comprises an energy storage inductance.

Preferably, the energy transfer module is coupled between the energy buffer module and the energy storage module, and comprises a second transformer, a second diode, a turn-off current source and a control module;

the second main-stage winding of the second transformer and the turn-off current source are coupled between the energy buffer module and the ground in series;

the control module controls the on and off of the turn-off current source, and leakage inductance energy buffered in the energy buffer module is transferred to the energy storage module for recycling and utilization through a magnetic field coupling relation between windings of the second transformer, so that the conversion efficiency of the first transformer is improved.

Preferably, the energy transfer module is coupled with the energy buffer module and comprises a first auxiliary winding of a first transformer, a turn-off current source and a control module;

the first auxiliary winding and the turn-off current source are coupled between the energy buffer module and the ground in series;

the control module controls the on and off of the turn-off current source, and leakage inductance energy buffered in the energy buffer module is transferred to the energy storage module for recycling and utilization through a magnetic field coupling relation among the windings of the first transformer, so that the conversion efficiency of the first transformer is improved.

In a second aspect, an embodiment of the present invention provides a power supply system, including the leakage inductance absorbing circuit according to any one of the first aspects, where the power supply system includes a flyback converter, and the leakage inductance absorbing circuit is configured to improve a conversion efficiency of a transformer of the flyback converter.

In a second aspect, an embodiment of the present invention provides a power supply system, including the leakage inductance absorbing circuit according to any one of the first aspects, where the power supply system includes a forward converter, and the leakage inductance absorbing circuit is configured to improve a conversion efficiency of a transformer of the forward converter.

In a third aspect, an embodiment of the present invention provides an electronic device, including any one of the leakage inductance absorbing circuits described in the first aspect.

The embodiment of the invention has the following advantages:

according to the leakage inductance absorption circuit provided by the embodiment of the invention, the energy of the leakage inductance of the transformer can be recycled and utilized, and the efficiency of the transformer and a power supply system is improved.

The invention solves the problems of energy loss and heating caused by adopting a traditional RCD leakage inductance absorption circuit and a discharge resistor in a power supply system, and further can improve the efficiency of a transformer and the power supply system, reduce the heat dissipation volume, and reduce the volume and the cost of the manufactured driving power supply.

Drawings

FIG. 1a is a block diagram of an isolated power supply system and RCD sink circuit of the prior art;

FIG. 1b is a partial waveform diagram of an isolated power supply system of the prior art;

FIG. 2 is a block diagram of a power system and an absorption circuit of one embodiment of the present invention;

FIG. 3a is an energy transfer module of one embodiment of the present invention;

FIG. 3b is an energy transfer module of another embodiment of the present invention;

FIG. 3c is an energy transfer module according to another embodiment of the present invention;

FIG. 4a is an energy transfer module of another embodiment of the present invention;

FIG. 4b is an energy transfer module of another embodiment of the present invention;

fig. 5 is a block diagram of a power supply system and an absorption circuit according to another embodiment of the present invention.

Various features and elements are not drawn to scale in accordance with conventional practice in the drawings in order to best illustrate the specific features and elements associated with the invention. In addition, like elements/components are referred to by the same or similar reference numerals among the different drawings.

[ reference numerals description ]

10: leakage inductance absorption circuit

101: energy transfer module

102: energy buffer module

103: energy transfer module

1031: control module

1032: current source capable of being turned off

1033: second diode

104: energy storage module

20: first power stage

202: freewheel module

30: second power stage

[ symbolic description ]

MP0: zero power switch

GP0: zero power switch control terminal

MP: first power switch

GP: first power switch control terminal

Vds: cross-over pressure

T1: first transformer

Lp1: first main stage winding

Ip1: first main stage winding current

Ls1: first secondary winding

Is1: first secondary winding current

La1: first auxiliary winding

Im: current can be turned off

Lk: leakage inductance

Nps1: turns ratio

T2: second transformer

Lp2: second main stage winding

Ip2: second main stage winding current

Ls2: second secondary winding

Is2: second secondary winding current

VIN: input voltage

VOUT: output voltage

SW: switch node

Rlp: bleeder resistor

Clp: clamping capacitor

Coss: parasitic capacitance

CIN: input capacitance

CO: and an output capacitance.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

In order to facilitate the deep understanding of the inventive concept by those skilled in the art, the technical problem of the present invention will be further described first.

As shown in fig. 1a and fig. 1b, after the driving signal GP0 of the zeroth power switch MP0 changes from high level to low level, the energy on the first main winding Lp1 of the first transformer T1 Is coupled to the first secondary winding Ls1 to form a first secondary winding current Is1 to discharge the output capacitor CO and the load, the energy on the leakage inductance Lk cannot be coupled to the first secondary winding Ls1, high-frequency LC resonance occurs with the parasitic capacitor Coss of the switch node SW, the high-frequency resonance voltage on the switch node SW charges the clamp capacitor Clp through the diode D2, if the bleeder resistor Rlp Is not present, the voltage on the clamp capacitor Clp continuously rises, and finally the voltage of the switch node SW exceeds the maximum withstand voltage of the zeroth power switch MP0, so that the zeroth power switch MP0 Is broken down by voltage breakdown, and therefore, the bleeder resistor Rlp must be connected across the clamp capacitor Clp in parallel to ensure that the redundant energy on the clamp capacitor Clp Is consumed through the bleeder resistor Rlp; when the driving signal GP0 is at a low level, the average voltage of the switching node SW is vin+ Nps1 ×vout (Nps is the turns ratio of the first primary winding Lp1 to the first secondary winding Ls1 of the first transformer T1), and the voltage on the clamping capacitor Clp is approximately equal to Nps1 ×vout. The RCD absorption circuit composed of Rlp, clp and D2 can absorb the energy of the leakage inductance Lk of the first transformer T1, ensuring the safety of the zeroth power switch MP0, but also losing the conversion efficiency of the first transformer T1.

In order to solve the above technical problems, or to improve the conversion efficiency of the first transformer T1 and also improve the conversion efficiency of the power supply, and reduce the volume and cost of the heat sink, embodiments of the present invention provide a leakage inductance absorption circuit, a power supply system, and an electronic device.

In a first aspect, an embodiment of the present invention provides a leakage inductance absorption circuit, as shown in fig. 2, in a power supply system of a flyback converter, which includes an input capacitor CIN, an output capacitor CO, a load, a first power stage 20, and a leakage inductance absorption circuit 10 coupled to the first power stage 20.

The first power stage 20 of the flyback converter includes a first transformer T1, a first power switch MP and a rectifying circuit 202, where the first transformer T1 includes a first main winding Lp1, a first secondary winding Ls1 and an equivalent leakage inductance Lk coupled in series with the first main winding Lp1, it should be noted that the leakage inductance Lk is only an equivalent result, a specific connection relationship is not limited, and it is generally considered that the leakage inductance Lk is connected in series with the main winding; the first end of the input capacitor CIN is coupled to the first end of the equivalent leakage inductance Lk, the second end of the equivalent leakage inductance Lk is coupled to the non-homonymous end of the first main winding Lp1, the homonymous end of the first main winding Lp1 is coupled to the first end of the first power switch MP, the homonymous end of the first secondary winding Ls1 is coupled to the first end of the rectifying circuit 202, the second end of the rectifying circuit 202 is coupled to the first end of the output capacitor CO, and the second end of the output capacitor CO is coupled to the non-homonymous end of the first secondary winding Ls 1.

The leakage inductance absorbing circuit 10 includes: an energy transfer module 101 configured to transfer leakage inductance energy of the first transformer T1; an energy buffer module 102 configured to buffer the leakage inductance energy of the first transformer T1; an energy transfer module 103 configured to transfer leakage inductance energy buffered in the energy buffer module 102; an energy storage module 104 configured to store and utilize leakage inductance energy transferred by the energy transfer module 103; the leakage inductance absorbing circuit 10 recovers and utilizes the leakage inductance energy of the first transformer T1, and improves the conversion efficiency of the first transformer T1.

In one embodiment, as illustrated in fig. 2, the energy transfer module 101 is coupled to the homonymous terminal of the first primary winding Lp1 of the first transformer T1, and includes a first diode.

In one embodiment, as shown in fig. 2, the anode of the first diode in the energy transfer module 101 is coupled to the same-name end of the first main winding Lp1 of the first transformer T1, and is also coupled to the first end of the first power switch MP in the first power stage 20, the second end of the first power switch MP is coupled to ground, the control terminal GP of the first power switch MP is coupled to a control signal, and the control signal controls the on or off of the first power switch MP.

In one embodiment, as shown in fig. 5, the anode of the first diode in the energy transfer module 101 is coupled to the same-name end of the first main winding Lp1 of the first transformer T1, and is also coupled to ground, the non-same-name end of the first main winding Lp1 of the first transformer T1 is coupled to the second end of the first power switch MP in the second power stage 30 through the leakage inductance Lk, the first end of the first power switch MP is coupled to the first end of the input capacitor CIN, the second end of the input capacitor CIN is coupled to ground, the first power switch MP control end GP is coupled to a control signal, and the control signal controls the first power switch MP to be turned on or off.

In one embodiment, the energy buffer module 102 is serially coupled in a loop formed by the energy transfer module 101 and the first primary winding Lp1 of the first transformer T1, and includes an absorption capacitor.

In one embodiment, as shown in FIG. 2, a first terminal of the absorption capacitor in the energy buffer module 102 is coupled to the cathode of the first diode in the energy transfer module 101, and a second terminal is coupled to a first terminal of the input capacitor CIN.

In one embodiment, as shown in fig. 5, a first end of the absorption capacitor in the energy buffer module 102 is coupled to the cathode of the first diode in the energy transfer module 101, and a second end is coupled to the second end of the first power switch MP, or the second end is coupled to the second end of the first power switch MP through a capacitor.

In one embodiment, the energy storage module 104 includes a storage capacitor.

In one embodiment, the storage capacitance in the energy storage module 104 is the input capacitance CIN.

In one embodiment, the storage capacitance in the energy storage module 104 is the output capacitance CO.

In one embodiment, the energy transfer module 103 is coupled between the energy buffer module 102 and the energy storage module 104, and includes a second transformer T2, a second diode 1033, a turn-off current source 1032, and a control module 1031; the two windings of the second transformer T2 are a second main winding Lp2 and a second secondary winding Ls2, respectively, and in one embodiment, the second main winding Lp2 and the second secondary winding Ls2 of the second transformer T2 have identical ends at the same position; in one embodiment, the second primary winding Lp2 and the second secondary winding Ls2 of the second transformer T2 have homonymous ends in different positions; the primary winding Lp2 of the second transformer T2 is coupled in series with the turn-off current source 1032 between the energy buffer module 102 and ground; in one embodiment, the second primary winding Lp2 of the second transformer T2 is coupled between the energy buffer module 102 and the off-state current source 1032; in one embodiment, the turn-off current source 1032 is coupled between the second primary winding Lp2 of the second transformer T2 and the energy buffer module 102; the second secondary winding Ls2 of the second transformer T2 is coupled in series with the second diode 1033 and then coupled between the energy storage module 104 and ground; the control module 1031 controls the on and off of the current source 1032, and transfers the leakage inductance energy buffered in the energy buffer module 102 to the energy storage module 104 for recycling and utilizing through the magnetic field coupling relationship between the second primary winding Lp2 and the second secondary winding Ls2 of the second transformer T2, thereby improving the conversion efficiency of the first transformer T1.

The homonymous ends of the two windings of the transformer are defined as follows: when current flows into (or out of) two windings simultaneously from one end of each winding respectively, if magnetic fluxes generated by the two windings are aided, the two ends are called as homonymous ends of the transformer winding, and black dots "·" or asterisks are used for marking. The positions of the homonymous terminals can be defined by themselves, the inflow terminals can be called homonymous terminals, and the outflow terminals can be called homonymous terminals.

Referring to fig. 2 and 3a, when the signal at the control terminal GP of the first power switch MP in the first power stage 20 changes from high level to low level, the energy on the first main winding Lp1 of the first transformer T1 Is coupled to the first secondary winding Ls1 to form a first secondary winding current Is1 to discharge the output capacitor CO and the load, the energy on the leakage inductance Lk cannot be coupled to the first secondary winding Ls1, and high-frequency LC resonance occurs with the parasitic capacitor Coss of the switch node SW, and the high-frequency resonance voltage on the switch node SW charges the absorption capacitor in the energy buffer module 102 through the first diode in the energy transfer module 101, so that the energy on the absorption capacitor increases, and the voltage on the absorption capacitor increases; the control module 1031 in the energy transfer module 103 controls the turn-off current source 1032 to be turned on, since the second primary winding Lp2 and the second secondary winding Ls2 of the second transformer T2 have identical-name ends, when the turn-off current Im generated by the turn-off current source 1032 flows out from the identical-name end of the second primary winding Lp2 of the second transformer T2, a second secondary winding current Is2 flowing into the identical-name end of the second secondary winding Ls2 Is generated by coupling the second secondary winding Ls2 of the second transformer T2, the second secondary winding current Is2 flows into the energy storage module 104 through the second diode 1033, and the turn-off current Im generated by the turn-off current source 1032 comes from the absorption capacitor in the energy buffer module 102, which Is equivalent to transferring the energy buffered in the energy buffer module 102 to the energy storage module 104 for recycling. The triggering condition of the control module 1031 for controlling the turn-off current source 1032 to be turned on may be in various manners, and in one embodiment, the signal indicating that the demagnetization of the first transformer T1 is finished triggers the control module 1031 to control the turn-off current source 1032 to be turned on; in another embodiment, the valley signal that characterizes the cross voltage Vds across the first power switch MP triggers the control module 1031 to control the turn-off current source 1032 to be turned on; in another embodiment, the PWM signal of the first power switch control terminal GP triggers the control module 1031 to control the turn-off current source 1032 to be turned on.

The difference between fig. 3a and fig. 3b Is that the identical end positions of the second transformer T2 are different, and when the second transformer T2 in fig. 3a Is turned on by the turn-off current source 1032, the turn-off current Im flows through the second primary winding Lp2 of the second transformer T2, and meanwhile, the second secondary winding Ls2 Is coupled to generate the second secondary winding current Is2 to transfer energy into the storage module 104; the second transformer T2 in fig. 3b stores energy by the turn-off current Im flowing through the second primary winding Lp2 of the second transformer T2 when the turn-off current source 1032 Is turned on, and the second secondary winding Ls2 Is coupled to generate the second secondary winding current Is2 to transfer energy to the storage module 104 after the turn-off current source 1032 Is turned off.

The difference between fig. 3c and fig. 3a, 3b Is that the second secondary winding current Is2 resulting from the coupling of the second secondary winding Ls2 of the second transformer T2 in fig. 3a and 3b Is from ground; whereas the second secondary winding current Is2 resulting from the coupling of the second secondary winding Ls2 of the second transformer T2 in fig. 3c comes from the switching node SW, i.e. the common node of the first primary winding Lp1 of the first transformer T1 and the first power switch MP.

In one embodiment, the storage capacitance in the energy storage module 104 is an input capacitance CIN, and energy corresponding to leakage inductance Lk is transferred from the absorption capacitance to the input capacitance CIN, and when the next switching period arrives, the stored leakage inductance energy in the input capacitance CIN is transferred to the output capacitance CO for reuse.

In one embodiment, the storage capacitor in the energy storage module 104 is the output capacitor CO, and the energy corresponding to the leakage inductance Lk is transferred from the absorption capacitor to the output capacitor CO to be reused.

The present invention improves the conversion efficiency of the first transformer T1 because the leakage inductance energy of the first transformer T1 is transferred to the energy storage module 104 for recovery and utilization without being converted into heat by the bleeder resistor Rlp as in the conventional RCD snubber circuit.

In one embodiment, the energy storage module 104 includes a storage inductor.

In one embodiment, the energy transfer module 103 is coupled with the energy cache module 102, the energy transfer module 103 comprising a first auxiliary winding La1 of a first transformer T1, a switchable current source 1032, and a control module 1031; in one embodiment, the first auxiliary winding La1 of the first transformer T1 has the same-name end at the same position as the first main winding Lp1 of the first transformer T1; in one embodiment, the first auxiliary winding La1 of the first transformer T1 and the first main winding Lp1 of the first transformer T1 have identical terminals at different positions; the first auxiliary winding La1 is coupled in series with the switchable current source 1031 between the energy cache module 102 and ground; in one embodiment, the first auxiliary winding La1 is coupled between the energy buffer module 102 and the off-state current source 1031. In one embodiment, a turn-off current source 1031 is coupled between the first auxiliary winding La1 and the energy buffer module 102. The control module 1031 controls the on and off of the current source 1031, and transfers the leakage inductance energy buffered in the energy buffer module 102 to the energy storage module 104 for recycling and utilizing through the magnetic field coupling relation between the windings of the first transformer T1, thereby improving the conversion efficiency of the first transformer T1.

Referring to fig. 2 and 4a, when the signal at the control terminal GP of the first power switch MP in the first power stage 20 changes from high level to low level, the energy on the first main winding Lp1 of the first transformer T1 Is coupled to the first secondary winding Ls1 to form a first secondary winding current Is1 to discharge the output capacitor CO and the load, the energy on the leakage inductance Lk cannot be coupled to the first secondary winding Ls1, and high-frequency LC resonance occurs with the parasitic capacitor Coss of the switching node SW, and the high-frequency resonance voltage on the switching node SW charges the absorption capacitor in the energy buffer module 102 through the first diode in the energy transfer module 101, so that the energy on the absorption capacitor increases, and the voltage on the absorption capacitor increases. The control module 1031 in the energy transfer module 103 controls the turn-off current source 1031 to be turned on, and since the first auxiliary winding La1 and the first main winding Lp1 of the first transformer T1 have identical terminals at the same position, when the turn-off current Im generated by the turn-off current source 1032 flows out from the identical terminal of the first auxiliary winding La1 of the first transformer T1, a first main winding current Ip1 flowing into the identical terminal of the first main winding Lp1 is generated by coupling on the first main winding Lp1 of the first transformer T1, the first main winding current Ip1 flows into the energy storage module 104, and the turn-off current Im generated by the turn-off current source 1032 comes from the absorption capacitor in the energy buffer module 102. Equivalent to the energy buffered in the energy buffer module 102 being transferred to the energy storage module 104 for recycling and utilization by the first transformer T1. The triggering condition of the control module 1031 for controlling the turn-off current source 1032 to be turned on may be in various manners, and in one embodiment, the signal indicating that the demagnetization of the first transformer T1 is finished triggers the control module 1031 to control the turn-off current source 1032 to be turned on; in another embodiment, the valley signal that characterizes the cross voltage Vds across the first power switch MP triggers the control module 1031 to control the turn-off current source 1032 to be turned on; in another embodiment, the PWM signal of the first power switch control terminal GP triggers the control module 1031 to control the turn-off current source 1032 to be turned on.

The difference between fig. 4a and fig. 4b is that the first transformer T1 in fig. 4a, when the turn-off current source 1032 is on, the turn-off current Im flows through the first auxiliary winding La1 of the first transformer T1, while the first main winding Lp1 is coupled to generate the first main winding current Ip1 to transfer energy into the memory module 104; the first transformer T1 in fig. 4b stores energy by the turn-off current Im flowing through the first auxiliary winding La1 of the first transformer T1 when the turn-off current source 1032 is on, and the first main winding Lp1 is coupled to generate the first main winding current Ip1 when the turn-off current source 1032 is off, so as to transfer energy into the memory module 104.

In one embodiment, the energy storage inductance in the energy storage module 104 is the first main winding Lp1 of the first transformer T1, and the energy corresponding to the leakage inductance Lk is transferred from the absorption capacitor to the first main winding Lp1 of the first transformer T1, and when the next switching period arrives, the leakage inductance energy stored in the first main winding Lp1 of the first transformer T1 is transferred to the output capacitor CO for reuse.

In an embodiment, the power supply system is a forward converter, and the leakage inductance absorbing circuit of the present invention is used to improve the conversion efficiency of the first transformer of the forward converter, and the principle thereof is similar, and will not be repeated herein.

The current source 1032 is not described in detail, but the current source 1032 may be implemented by a switch connected in series with a current source, and the current of the current source may be generated by current mirror, or by superimposing a reference voltage on a resistor; or more simply directly by the size of the switch, when the switch is on, the turn-off current Im is turned on, and when the switch is off, the turn-off current Im is turned off. From the above description, it can be seen that the above embodiments of the present application achieve the following technical effects:

1) According to the leakage inductance recovery circuit, leakage inductance energy of the transformer is recovered and utilized, so that the conversion efficiency of the transformer is improved, the temperature and the heat dissipation cost of a power supply system can be reduced, the efficiency and the reliability of the power supply system can be improved, and the volume of the power supply system is reduced.

2) According to the power supply system, leakage inductance energy of the transformer is recycled and utilized, so that the conversion efficiency of the transformer is improved, the temperature and the heat dissipation cost of the power supply system can be reduced, the efficiency and the reliability of the power supply system can be improved, and the volume of the power supply system is reduced.

3) According to the electronic device, the leakage inductance energy of the transformer is recycled and utilized, so that the conversion efficiency of the transformer is improved, the temperature and the heat dissipation cost of a power supply system can be reduced, the efficiency and the reliability of the power supply system can be improved, and the volume of the power supply system is reduced.

It should be noted that, in the present specification, each embodiment is described in a progressive manner, and each embodiment is mainly described as different from other embodiments, and identical and similar parts between the embodiments are all enough to be referred to each other.

It should also be noted that, in this document, the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate orientations or positional relationships based on those shown in the drawings, and are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the apparatus or elements to be referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention. Moreover, relational terms such as "first" and "second" may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions, or order, and without necessarily being construed as indicating or implying any relative importance. "and/or" means either or both of which may be selected. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or terminal that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or terminal. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or terminal device comprising the element.

The foregoing has outlined rather broadly the more detailed description of the invention in order that the detailed description of the invention that follows may be better understood, and in order that the present contribution to the art may be better appreciated. While various modifications of the embodiments and applications of the invention will occur to those skilled in the art, it is not necessary and not intended to be exhaustive of all embodiments, and obvious modifications or variations of the invention are within the scope of the invention.

Claims

1. A leakage inductance absorption circuit for use in a power system including a first transformer, the leakage inductance absorption circuit comprising:

an energy transfer module configured to transfer leakage inductance energy buffered in the energy buffer module;

an energy storage module configured to store and utilize leakage inductance energy transferred by the energy transfer module;

the leakage inductance absorption circuit recovers and utilizes the leakage inductance energy of the first transformer, and improves the conversion efficiency of the first transformer.

2. The leakage inductance absorbing circuit of claim 1, wherein the energy transfer module is coupled to the first primary winding of the first transformer, comprising a first diode.

3. The leakage inductance absorption circuit of claim 1, wherein the energy buffer module is coupled in series in a loop formed by the energy transfer module and the first primary winding of the first transformer, including an absorption capacitance.

4. The leakage inductance absorbing circuit of claim 1, wherein the energy storage module comprises a storage capacitor.

5. The leakage inductance absorbing circuit of claim 1, wherein the energy storage module comprises a storage inductor.

6. The leakage inductance absorbing circuit of claim 4, wherein the energy transfer module is coupled between the energy buffer module and the energy storage module, comprising a second transformer, a second diode, a turn-off current source, and a control module;

7. The leakage inductance absorbing circuit of claim 5, wherein the energy transfer module is coupled to the energy buffer module, comprising a first auxiliary winding of a first transformer, a turn-off current source, and a control module;

8. A power supply system comprising the leakage inductance absorbing circuit of any one of claims 1 to 6, wherein the power supply system comprises a flyback converter, the leakage inductance absorbing circuit being configured to increase the conversion efficiency of a first transformer of the flyback converter.

9. A power supply system comprising the leakage inductance absorbing circuit of any one of claims 1 to 6, wherein the power supply system comprises a forward converter, and the leakage inductance absorbing circuit is configured to increase the conversion efficiency of a first transformer of the forward converter.

10. An electronic device comprising the leakage inductance absorbing circuit of any one of claims 1 to 7.