CN201616658U

CN201616658U - Reverse energy recovering circuit

Info

Publication number: CN201616658U
Application number: CN2010200002979U
Authority: CN
Inventors: 施永祥; 干宗平
Original assignee: FSP Technology Inc
Current assignee: FSP Technology Inc
Priority date: 2010-01-12
Filing date: 2010-01-12
Publication date: 2010-10-27
Anticipated expiration: 2020-01-12

Abstract

The utility model provides a reverse energy recovering circuit which is arranged in a power conversion circuit provided with a transformer, wherein a primary side winding of the transformer is connected with a power switch which is driven by a control unit so as to determine the period of input power flowing past the primary side winding; the reverse energy recovering circuit is connected between the first end and the second end of the primary side winding; the reverse energy recovering circuit comprises a first capacitor, a second capacitor, an auxiliary winding and a diode; the first capacitor and the second capacitor are serially connected with each other; one end of the second capacitor is connected with the first end of the primary side winding; the first end of the auxiliary winding is connected with the first end of the primary side winding; a cathode of the diode is connected with the second end of the auxiliary winding; and an anode of the diode is connected between the first capacitor and the second capacitor to lead the diode and the auxiliary winding to form at a one-way path between the first capacitor and the second capacitor.

Description

The backward energy recovery circuit

Technical field

The utility model relates to a kind of backward energy recovery circuit, particularly is arranged in the power conversion circuit with transformer, is used to reclaim the reverse surging energy that produces is switched at the transformer two ends because of moment backward energy recovery circuit.

Background technology

Because many electrical equipment all need drive by the electric power of specific voltage position standard (voltage levvl) now, thereby power-switching circuit becomes the circuit of extensive use, and updates in the hope of output voltage stabilization, conversion efficiency height.The factor that influences power conversions has comprised the loss of element itself, and energy transfers the kenel of magnetic force to and the loss that leaks or cancel out each other during power conversion.Wherein the transformer of this change-over circuit is because by a large amount of electric currents, therefore the leakage inductance that is stored in the transformer is understood continuous energy storage and is produced reverse surging (square-wave waveform leading edge as shown in Figure 1) when the power switch of change-over circuit constantly switches, this reverse surging constantly puts on and is connected on the other element of transformer, get off for a long time to make the performance performance of peripheral element (comprising power component, electric capacity etc.) to be not so good as expection, even reduce in the life-span.Moreover if the energy of this reverse surging will cause power conversion efficiency to reduce without suitable guiding, even the suitable guiding of this reverse surging process, oppositely the energy of surging still is included in the loss, so the conversion efficiency of circuit integral body obviously promotes.

In order to improve conversion efficiency to meet the rigorous energy standard in various countries, existing previous patent application proposes the improvement scheme at above-mentioned surging problem, No. the 583830th, TaiWan, China patent announcement " transducer " for example with active LC damping circuit, this utilizes a LC damping circuit to suppress surging in preceding application, and the energy that reclaims surging re-uses, wherein LC damping circuit is by a diode, one electric capacity, one second transformer and a second switch constitute, wherein the main transformer of this circuit side has known clamp capacitor (Cs) storage power, and the guiding that sees through diode makes the energy of reverse surging to be sent to second transformer by clamp capacitor (Cs), through second Circuit Fault on Secondary Transformer and second switch and above-mentioned electric capacity, to reclaim the energy of reverse surging by this, and utilize the energy of reverse surging to supply one second load.This utility model has reached and has suppressed the purpose of surging, recuperated energy, but is to be provided with one second transformer and a second switch than significant disadvantages more, and not only cost is higher, more takies limited space in the power circuit housing.Moreover though oppositely the surging recycling is in offered load, oppositely the energy of surging sees through the conversion of second transformer, certainly will be converted to the loss of secondary side again through primary energy, and therefore the cost that increases is much larger than the effect that produces.

The utility model content

Because above-mentioned the deficiencies in the prior art, the application's purpose is to provide a kind of inhibition transformer backward energy, even reclaims the recovery circuit that this backward energy utilizes again, damages electronic component to avoid backward energy, or the life-span of this electronic component that detracts.

The application is a kind of backward energy recovery circuit, this backward energy recovery circuit is arranged in the power conversion circuit with transformer, wherein the transformer first side winding connects a power switch, this power switch is driven by a control unit and the cycle of decision input power flows first side winding, and is connected the backward energy recovery circuit between first end of first side winding and second end.Wherein the backward energy recovery circuit comprises one first electric capacity, one second electric capacity, an auxiliary winding and a diode, and first electric capacity is connected mutually with second electric capacity, and an end of second electric capacity is connected in first end of first side winding.First end of auxiliary winding is connected in first end of first side winding, the negative electrode of diode connects second end of auxiliary winding, the anode of diode is connected between first electric capacity and second electric capacity, makes diode and auxiliary winding be formed on unidirectional path between first electric capacity and second electric capacity.Whether the conducting of diode, and the decision backward energy is charged to first electric capacity, second electric capacity by first end of first side winding, or passes through diode discharge for first electric capacity.

By the above-mentioned path that discharges and recharges, the stored backward energy of transformer is stored and utilize again, and above-mentioned circuit structure is simple, be provided with low costly, do not take too much space.

Description of drawings

Fig. 1 is existing backward energy waveform schematic diagram.

Fig. 2 is the application's an execution mode schematic diagram ().

Fig. 3 is the application's an execution mode schematic diagram (two).

Fig. 4 is the application's a circuit node A waveform schematic diagram.

Embodiment

The application is a kind of backward energy recovery circuit, and this backward energy recovery circuit is arranged in the power conversion circuit, sees also the execution mode schematic diagram of Fig. 2 and Fig. 3.Visible power conversion circuit has a transformer 1 among the figure, this transformer 1 comprises a first side winding 11 and a secondary side winding 12, first side winding connects a power switch 2, and power switch 2 is controlled by a control unit 3, by the conducting of control unit 3 decision power switchs 2 whether, further determine the cycle of an input power flows first side winding 11, secondary side winding 12 then sees through magnetic induction and produces an induction power.Be connected the backward energy recovery circuit between first end of first side winding 11 and second end, the backward energy recovery circuit comprises one first electric capacity 41, one second electric capacity, 42, one an auxiliary winding 43 and a diode 44.Wherein first electric capacity 41 is connected with second electric capacity 42, and an end of second electric capacity 42 is connected in first end of first side winding 11.First end of auxiliary winding 43 also is connected in first end of first side winding 11, and second end of auxiliary winding 43 is connected with the negative electrode of diode 44, and the anode of diode 44 then is connected between first electric capacity 41 and second electric capacity 42.Therefore, forming one between first electric capacity 41 and second electric capacity 42 can be for the unidirectional path of first electric capacity, 41 discharges.In addition, first end of auxiliary winding 43 is an opposite magnetic polarities with its first side winding that is connected 11 first ends, and when making first side winding 11 have electric current to pass through, auxiliary 43 of windings are sensed opposite polarity.

See also Fig. 2, when power switch 2 conductings, input electric power can flow to first side winding 11 (as the I1 that is indicated among the figure), make first side winding 11 have electric current to pass through, and produce induction power in secondary side winding 12, simultaneously, first side winding 11 can store an energy because of leakage inductance.Please consult Fig. 3 again, when power switch 2 disconnected, power path is blocked suddenly changed the generation voltage instantaneous, made and saved in the mobile backward energy that forms of the energy back of first side winding 11.This moment, auxiliary 43 inductions because of first side winding 11 of winding were sensed high voltage at first end, made diode 44 end, and then the decision backward energy is to first

electric capacity

41,42 chargings of second electric capacity.Power switch 2 is in following one-period once more during conducting, drag down the voltage of auxiliary winding 43 first ends because of the induction of first side winding 11, diode 44 conductings are discharged (I2 as shown in Figure 2) by diode 44 for first electric capacity 41, make the backward energy that is stored in first electric capacity 41, second electric capacity 42 be back to first side winding 11 once more.

In sum, the auxiliary winding 43 of backward energy recovery circuit utilization cooperates diodes 44 and the path of backward energy is reclaimed, emitted in decision, can make backward energy can irritate back first side winding 11 again, and be sent to the output of secondary side winding 12 as transformer 1.See through the backward energy recovery circuit and absorb recuperated energy, can make voltage waveform on the circuit node A more near square wave, and the transient voltage surging that power switch 2 switches can be avoided element to be subjected to surging and destroy by obvious suppression.Moreover, because first end of auxiliary winding 43 is an opposite magnetic polarities with its first side winding that is connected 11 first ends, therefore form flyback circuit (flyback, flyback circuit) basic framework, responsibility cycle (the duty cycle that makes power switch 2 work, work period) can be greater than 50%, and owing to first electric capacity 41, second electric capacity 42 have stored backward energy, therefore after input electric power ended, first electric capacity 41 and second electric capacity 42 can prolong hold time (holdtime) again through emitting backward energy.

Though the application discloses as above with preferred embodiment; right its is not in order to limit the utility model; any those skilled in the art; under the situation that does not break away from spirit and scope of the present utility model; a little change and the retouching done; all should be covered by in the utility model, therefore protection range of the present utility model is as the criterion when looking appending claims.

Claims

1. backward energy recovery circuit, be arranged in the have transformer power conversion circuit of (1), wherein said transformer (1) first side winding (11) connects a power switch (2), described power switch (2) is driven by a control unit (3) and determines one to import the cycle of the described first side winding of power flows (11), and be connected a backward energy recovery circuit between first end of described first side winding (11) and second end, it is characterized in that described backward energy recovery circuit comprises:

One first electric capacity (41) and one second electric capacity (42) that is series at described first electric capacity (41), an end of wherein said second electric capacity (42) is connected in first end of described first side winding (11);

One auxiliary winding (43), first end of described auxiliary winding (43) is connected in first end of described first side winding (11);

One diode (44), the anode of described diode (44) is connected between described first electric capacity (41) and second electric capacity (42), second end that the negative electrode of described diode (44) connects described auxiliary winding (43) is charged to described first electric capacity (41), second electric capacity (42) by first end of first siding ring to determine described backward energy, and discharges by described diode (44) for described first electric capacity (41).

2. backward energy recovery circuit according to claim 1 is characterized in that, first end of described auxiliary winding (43) is an opposite magnetic polarities with its first side winding that is connected (11) first ends.