CN205693568U - A kind of DC DC changer - Google Patents

Abstract

This utility model provides a kind of DC DC changer, including driving power supply, the first changer, the second changer, the first input filter capacitor, the second input filter capacitor and equilibrium electric capacity；One end of equilibrium electric capacity connects the first input filter capacitor and the common port of the second input filter capacitor, and the other end connects the first changer and the common port of the second changer.After setting up equilibrium electric capacity in this utility model, when two input filter capacitor characteristics are inconsistent, two changer input terminal voltages can be automatically adjusted, it is achieved input voltage equilibrium purpose；When two input filter capacitor characteristics are consistent, and when two changer characteristics are inconsistent, equilibrium electric capacity can adjust the input current increment of two changers, corrects the property difference of two changers.Owing to, only on the input circuit of existing converter circuit, being additionally arranged one and equalizing electric capacity, simple circuit, it is simple to batch production and with low cost；Need not debug for other elements of circuit and can realize all pressing current-sharing effect, reliability is high.

Description

A kind of DC-DC converter

Technical field

This utility model relates to electric and electronic technical field, particularly to a kind of DC-DC (DC-to-dc) changer.

Background technology

In input voltage is up to the DC-DC converter of more than 1500V, for reducing cost, facilitate adopting of power MOS pipe Purchasing, the general double-transistor flyback using two or more input series and output parallel or diode degaussing two-transistor forward converter complete High pressure is to the conversion of low pressure.It is illustrated in figure 1 input series and output parallel double-transistor flyback DC-DC converter of the prior art, Including driving power supply V_IN, input filter capacitor C1, C2；The equalizing resistance R1 in parallel with input filter capacitor C1 and input filter The equalizing resistance R2 that electric capacity C2 is in parallel；Two double-transistor flyback changers are (in figure shown in 11 and 12, wherein around the position of group mark "●" Put phase antirepresentation double-transistor flyback)；Output filter capacitor E1 and output voltage Vo；Wherein, each double-transistor flyback changer all wraps Include two switching tubes (Q1-Q2 or Q3-Q4), two diodes (D1-D2 or D3-D4), energy storage inductor (Np1-Ns1 or Np2-Ns2), output diode (D5 or D6).It is illustrated in figure 2 input series and output parallel double tube positive exciting of the prior art DC-DC converter, its structure is similar to the transformer configuration of input series and output parallel double-transistor flyback shown in Fig. 1, difference It is two-transistor forward converter (in figure, the position around group mark "●" is identical) for two changers 21 therein with 22, and output unit Divide and also include diode D7 and inductance L.

In both the above circuit, when terminal voltage V of input filter capacitor C1_C1And terminal voltage V of input filter capacitor C2_C2 Equal, and at V_INTime near/2, the driving voltage of input is 1500V, then become at input series and output parallel double-transistor flyback DC-DC In parallel operation or input series and output parallel double tube positive exciting DC-DC converter, power MOS pipe (Q1～Q4) resistance to pressure request is only 800V.Otherwise, when terminal voltage V of input filter capacitor C1_C1And terminal voltage V of input filter capacitor C2_C2Substantial deviation V_IN/2 Time, the power MOS pipe that more than 900V is pressure is also possible to the breakdown phenomenon of overvoltage occur.

To this end, the capacity that prior art is strict with input filter capacitor C1 and input filter capacitor C2 is equal, leakage current Unanimously；Two changer input characteristics are identical, such as leakage inductance, power MOS pipe Q1～Q4 characteristic between armature winding and secondary windings Deng the most same or like, this not only adds the difficulty of element pairing, the processing technology of changer be it is also proposed the highest Requirement, ultimately increase the cost of changer, reduce the reliability of changer.

Utility model content

In view of this, this utility model provides a kind of DC-DC converter, joins solving in prior art element in changer The problem that higher to difficulty, changer cost of manufacture is higher, reliability is low.

For achieving the above object, the following technical scheme of this utility model offer:

A kind of DC-DC converter, including:

Drive power supply, the first changer, the second changer, the first input filter capacitor, the second input filter capacitor and all Weighing apparatus electric capacity；

The positive input terminal of described first changer is connected with the anode of described first input filter capacitor, and is connected to described Drive the positive pole of power supply；

The negative input end of described first changer is connected with the positive input terminal of described second changer；

The negative input end of described second changer is connected with the negative terminal of described second input filter capacitor, and is connected to described Drive the negative pole of power supply；

The negative terminal of described first input filter capacitor is connected with the anode of described second input filter capacitor；

One end of described equilibrium electric capacity connects the public affairs of described first input filter capacitor and described second input filter capacitor End altogether, the other end connects the common port of described first changer and described second changer.

Preferably, described equilibrium electric capacity is an electric capacity.

Preferably, described equilibrium electric capacity includes multiple electric capacity connected with series-parallel system.

Preferably, described first changer is the first double-transistor flyback changer, described second changer be second two-tube instead Exciting converter.

Preferably, described first double-transistor flyback changer and described second double-transistor flyback changer have separate storage Can inductance.

Preferably, the armature winding of described first double-transistor flyback changer, secondary windings become with described second double-transistor flyback The armature winding of parallel operation, secondary windings are wound on same magnetic core framework, form integrated inductor.

Preferably, described first changer is the first two-transistor forward converter, described second changer be second two-tube just Exciting converter.

Preferably, described first two-transistor forward converter and described second two-transistor forward converter have separate change Depressor.

Preferably, the armature winding of described first two-transistor forward converter, secondary windings become with described second double tube positive exciting The armature winding of parallel operation, secondary windings are wound on same magnetic core framework, form integrated transformer.

Preferably, described first changer and described second changer are full-bridge converter or half-bridge converter

Via above-mentioned technical scheme understand, this utility model provide DC-DC converter, including drive power supply, first Changer, the second changer, the first input filter capacitor, the second input filter capacitor and equilibrium electric capacity；Described equilibrium electric capacity One end connects the common port of described first input filter capacitor and described second input filter capacitor, and the other end connects described first Changer and the common port of described second changer.This utility model is additionally arranged equilibrium electric capacity, when the first input filter capacitor Time different from the capacity of the second input filter capacitor, in converter switches pipe turn on process, equilibrium electric capacity can dynamically adjust First changer input terminal voltage and the second changer input terminal voltage, before switching tube is closed, make the first changer input Terminal voltage is equal with the second changer input terminal voltage；When the first input filter capacitor and the second input filter capacitor capacity phase With, characteristic is consistent, and when the characteristic of the first changer and the second changer is inconsistent, equilibrium electric capacity can adjust two changers Input current increment, thus reach to correct the property difference of two changers.

The equilibrium electric capacity that the changer provided in this utility model is set up is to two input filter capacitors or two changers Input characteristics deviation have good portfolio effect.And changer only defeated at conventional converter circuits that this utility model provides Enter on circuit base, add one and equalize electric capacity, simple circuit, it is simple to batch production, and with low cost；For circuit other Element need not be debugged and can realize all pressing current-sharing effect, and reliability is high.

Accompanying drawing explanation

In order to be illustrated more clearly that this utility model embodiment or technical scheme of the prior art, below will be to embodiment Or the required accompanying drawing used is briefly described in description of the prior art, it should be apparent that, the accompanying drawing in describing below is only It is embodiment of the present utility model, for those of ordinary skill in the art, on the premise of not paying creative work, also Other accompanying drawing can be obtained according to the accompanying drawing provided.

Fig. 1 is input series and output parallel double-transistor flyback DC-DC converter circuit schematic diagram in prior art；

Fig. 2 is input series and output parallel double tube positive exciting DC-DC converter circuit schematic diagram in prior art；

The input series and output parallel DC-DC converter circuit schematic diagram that Fig. 3 provides for this utility model；

The input series and output parallel double-transistor flyback DC-DC converter operation principle explanation that Fig. 4 provides for this utility model Figure；

A kind of input series and output parallel double-transistor flyback DC-DC converter that Fig. 5 provides for this utility model embodiment two Circuit diagram；

The another kind of input series and output parallel double-transistor flyback DC-DC conversion that Fig. 6 provides for this utility model embodiment two The circuit diagram of device；

A kind of input series and output parallel double tube positive exciting DC-DC converter that Fig. 7 provides for this utility model embodiment two Circuit diagram；

The another kind of input series and output parallel double tube positive exciting DC-DC conversion that Fig. 8 provides for this utility model embodiment two The circuit diagram of device；

The circuit diagram of a kind of full-bridge DC-DC converter that Fig. 9 provides for this utility model embodiment two；

The circuit diagram of a kind of half-bridge DC-DC converter that Figure 10 provides for this utility model embodiment two.

Detailed description of the invention

Below in conjunction with the accompanying drawing in this utility model embodiment, the technical scheme in this utility model embodiment is carried out Clearly and completely describe, it is clear that described embodiment is only a part of embodiment of this utility model rather than whole Embodiment.Based on the embodiment in this utility model, those of ordinary skill in the art are not under making creative work premise The every other embodiment obtained, broadly falls into the scope of this utility model protection.

Embodiment one

As it is shown on figure 3, the present embodiment provides a kind of input series and output parallel DC-DC converter, including: drive electricity Source, first changer the 31, second changer the 32, first input filter capacitor C1, the second input filter capacitor C2 and equilibrium electric capacity C3；The positive input terminal of the first changer 31 and the anode of the first input filter capacitor C1 are connected, and are connected to just driving power supply Pole V_IN+；The negative input end of the first changer 31 and the positive input terminal of the second changer 32 are connected；The negative input end of the second changer It is connected with the negative terminal of the second input filter capacitor C2, and is connected to drive the negative pole V of power supply_IN-；Bearing of first input filter capacitor End is connected with the anode of the second input filter capacitor；One end of equilibrium electric capacity C3 connects the first input filter capacitor C1 and second defeated Entering the common port A of filter capacitor C2, the other end connects the first changer 31 and the common port B of the second changer 32.

It should be noted that the first changer described in the present embodiment and described second changer are by phase place, dutycycle phase Same signal drives.Described first changer and described second changer can be all two-transistor forward converter, double-transistor flyback change Parallel operation, full-bridge converter or half-bridge converter, do not limit this in the present embodiment.In other embodiments of the present utility model In, described first changer and described second changer can also is that other topological structure, and this is not limited by this utility model. In the present embodiment, the type to the switching tube related in described first changer and described second changer does not limits, this In embodiment, preferred described switching tube is N-channel power MOS pipe.

Equalizing electric capacity C3 in the present embodiment can be an electric capacity, it is also possible to be by multiple electricity connected with series-parallel system Hold the equivalent capacity of composition, the equivalent capacity of the most multiple series capacitances composition, or the equivalent capacity of multiple shunt capacitance composition, or Connect again after multiple electric capacity in parallel (or series connection) equivalent capacity that (or in parallel) form, this is not limited by the present embodiment.Institute The building form of the equilibrium electric capacity stated does not affects the specifically used effect of DC-DC converter in the present embodiment, and this is this area skill Art personnel easily learn, is not described in detail this in the present embodiment.

The DC-DC converter that the present embodiment provides, owing to being additionally arranged equalizing resistance C3, it is possible to dynamically adjusts the first changer Input terminal voltage V_IN1With the second changer input terminal voltage V_IN2, so that two changer input terminal voltages reach unanimity.

As a example by the double-transistor flyback DC-DC converter of the series connection output-parallel of input shown in Fig. 4, the present embodiment is described below The DC-DC converter provided realizes the principle all pressed.In Fig. 4, the first changer is double-transistor flyback changer 41, the second changer Also it is double-transistor flyback changer 42.Its relative prior art is the double-transistor flyback of the input series connection output-parallel shown in Fig. 1 DC-DC converter.

Double-transistor flyback DC-DC converter for the input of the prior art series connection output-parallel shown in Fig. 1 is come Say, if double-transistor flyback changer 11 is consistent with double-transistor flyback changer 12 input characteristics, i.e. at the beginning of double-transistor flyback changer 11 Level side inductance L_P1The primary side inductance L of (i.e. the inductance of Np1 winding shown in figure) and double-transistor flyback changer 12_P2(i.e. institute in figure Show the inductance of Np2 winding) equal, but the first input filter capacitor C1 ≠ the second input filter capacitor C2；

The terminal voltage of the first input filter capacitor C1 is:

$V_{C1}=\frac{C_2}{C_1+C_2}\×V_{IN}$

The terminal voltage of the second input filter capacitor C2 is:

$V_{C2}=\frac{C_1}{C_1+C_2}\×V_{IN}$

The relation assuming the first input filter capacitor C1 and the second input filter capacitor C2 is: C1=0.8 × C2, and drives Supply voltage V_INFor 1500V, then both end voltage V of the first input filter capacitor C1_C1=833.3V, the second input filter capacitor Both end voltage V of C2_C2=666.7V, it is seen then that the equal substantial deviation of both end voltage of two input filter capacitors driving power supply electricity Central value 750V of pressure, this phenomenon was especially apparent in DC-DC converter startup moment.

And after adding equilibrium electric capacity C3, owing to the relation of two input filter capacitors is C2 > C1, then two input filters Between the terminal voltage of ripple electric capacity, relation is V_C1>V_C2So that switching tube Q1-Q4 turns on moment, through two double-transistor flyback changers Current relationship be i_LP1>i_LP2, terminal voltage V of equilibrium electric capacity C3_C3Polarity is " the left negative right side is just ", and as shown in Figure 4, double-transistor flyback becomes The primary side input current increment of parallel operation 41 is:

${\mathrm{\Δi}}_{LP1}=\frac{V_{C1}-V_{C3}}{L_{P1}}t$

The primary side input current increment of double-transistor flyback changer 42 is:

${\mathrm{\Δi}}_{LP2}=\frac{V_{C2}+V_{C3}}{L_{P2}}t$

From primary side input current increment above it can be seen that along with equilibrium electric capacity C3 terminal voltage V_C3Increase, two-tube The primary side input current increment of anti exciting converter 41 and double-transistor flyback changer 42 gradually reaches unanimity.When equilibrium electric capacity C3 holds Switching tube conducting knot when measuring less, in a switch periods, in double-transistor flyback changer 41 and double-transistor flyback changer 42 Shu Qian, terminal voltage V_C3CloseThe then current increment phase of two double-transistor flyback changers With；On the other hand, the moment of the switching tube cut-off in double-transistor flyback changer 41 and double-transistor flyback changer 42, double-transistor flyback The maximum voltage V that switching tube in changer 41 bears_IN1=V_C1-V_C3, bear with the switching tube in double-transistor flyback changer 42 Maximum voltage V_IN2=V_C2+V_C3The most identical.

For C1 > C2 situation, equalize electric capacity C3 terminal voltage V_C3Polarity is " left positive right negative ", works as V_C3Tend towards stability valueTime, enter and all press equal stream mode.

Identical for input filter capacitor C1, C2 capacity, characteristic is consistent, the i.e. first input filter capacitor C1 and second input The terminal voltage relation of filter capacitor C2 is: V_C1=V_C2=V_IN/ 2, but the primary side inductance L of double-transistor flyback changer 41_P1Less than double The primary side inductance L of pipe anti exciting converter 42_P2, make switching tube conducting moment there is i_LP1>i_LP2Situation, equilibrium electric capacity C3 end Voltage V_C3Polarity is " the left negative right side is just ", and as shown in Figure 4, the primary side input current increment of double-transistor flyback changer 41 is:

${\mathrm{\Δi}}_{LP1}=\frac{V_{C1}-V_{C3}}{L_{P1}}t$

The primary side input current increment of double-transistor flyback changer 42 is:

${\mathrm{\Δi}}_{LP2}=\frac{V_{C2}+V_{C3}}{L_{P2}}t$

Two double-transistor flyback changer primary side input current increments can be with terminal voltage V of equilibrium electric capacity C3_C3Increase final Reach unanimity.Otherwise, as the primary side inductance L of double-transistor flyback changer 41_P1Primary side electricity more than double-transistor flyback changer 42 Sense L_P2Time, make the switching tube conducting moment i in double-transistor flyback changer 41 and double-transistor flyback changer 42_LP1<i_LP2, will cause all Weighing apparatus electric capacity C3 terminal voltage V_C3Polarity is " left positive right negative ", and two double-transistor flyback changer primary side input current increments equally can be along with Terminal voltage V of equilibrium electric capacity C3_C3Increase and finally reach unanimity.

As inductance L_P1With inductance L_P2Ratio be α, i.e.Time, calculating is learnt, if the terminal voltage of equilibrium electric capacity C3 V_C3CloseThe input current increment that just can make two double-transistor flyback changers connected is equal.In the present embodiment, Under the first input filter capacitor C1 and the second input filter capacitor C2 characteristic uniform condition, because of two double-transistor flyback changers Input characteristics is different, when can cause the switching tube cut-off of two double-transistor flyback changers, and the switch in double-transistor flyback changer 41 Pipe bears voltage V_IN1=V_C1-V_C3, the switching tube in double-transistor flyback changer 42 bears voltage V_IN2=V_C2+V_C3Difference, but difference Not quite.Such as, L is worked as_P1=0.9L_P2, V_INDuring=1500V, V_C3Only 39.5V, the voltage that the first converter switches pipe bears is 750V-39.5V, about 710.5V；The voltage that second converter switches pipe bears is 750V+39.5V, about 789.5V.

As can be seen from the above analysis, the DC-DC converter circuit that the present embodiment provides, it is additionally arranged in its input circuit After one equilibrium electric capacity, it is achieved that to because the input characteristics of input filter capacitor is inconsistent or because of the primary of double-transistor flyback changer Side input inductance differs, and input voltage and the input current of two the double-transistor flyback changers caused are adjusted.Circuit letter Clean, with low cost, other elements need not be debugged, i.e. can reach all pressure current-sharing purposes.

Below after only illustrating to increase equilibrium electric capacity as a example by input series and output parallel double-transistor flyback DC-DC converter Operation principle；When the first changer in input series and output parallel DC-DC converter and the second changer are that double tube positive exciting becomes When parallel operation (as shown in Figure 7, Figure 8), full-bridge (as shown in Figure 9) or half-bridge (as shown in Figure 10) topological structure, equilibrium electric capacity C3 is same Sample can be corrected and be mapped the terminal voltage of electric current, magnetizing inductance or input filter capacitor C1 and input filter capacitor C2 by primary side and differ Causing, during causing two changer input currents, cut-off, there is the phenomenon of difference in switch tube voltage stress.

Striding capacitance Cf realization all pressure effects are set up it should be noted that prior art has, but striding capacitance Cf Being in parallel with the relation of input filter capacitor C1 or input filter capacitor C2, time in parallel, total capacity is C1+Cf or C2+Cf, if C1, C2 are far longer than Cf, then effect is the most inconspicuous, and therefore, the capacity of striding capacitance of the prior art must be the biggest.

And the equilibrium electric capacity C3 that the present embodiment provides and the first input filter capacitor C1, or the second input filter capacitor C2 Relation is series relationship, and the terminal voltage of the armature winding Np1 of the first changer is V_C1+V_C3, the armature winding of the second changer The terminal voltage of Np2 is V_C2-V_C3(or the armature winding Np1 terminal voltage of the first changer is V_C1-V_C3, the primary of the second changer around Group Np2 terminal voltage is V_C2+V_C3)；The present embodiment utilizes the terminal voltage of equilibrium electric capacity C3 to adjust and is applied to armature winding Np1 and Np2 On voltage.

Concrete, when the first input filter capacitor C1 and the second input filter capacitor C2, the first changer in the present embodiment Time completely the same with the characteristic of the second changer, i_LP1=i_LP2, the terminal voltage of equilibrium electric capacity C3 is 0；Otherwise, when the first input filter When the characteristic of ripple electric capacity C1 and the second input filter capacitor C2 or the first changer and the second changer is not quite identical, flow through all The electric current of weighing apparatus electric capacity C3 is only i_LP1With i_LP2Difference.Visible, the electric current flowing through equilibrium electric capacity C3 is little, therefore, and this enforcement The current capacity that in example, equilibrium electric capacity C3 bears is less demanding, it may be preferred to low capacity, low pressure CBB electric capacity (metallized polyimide Propylene electric capacity).

The DC-DC converter that the present embodiment provides, is additionally arranged equilibrium electricity in prior art DC-DC converter input circuit Hold, it is possible to correct and mapped electric current, magnetizing inductance or the first input filter capacitor C1 and the second input filter capacitor C2 by primary side Terminal voltage inconsistent, during the two changer input currents that cause, cut-off, there is the phenomenon of difference in switch tube voltage stress.By In merely add equilibrium electric capacity, the input circuit structural change to DC-DC converter is less so that simple circuit, with low cost.

And owing to large bulk capacitance error is relatively big, for reducing capacitance pairing difficulty, at the first input filter in prior art Electric capacity C1 two ends high-power equalizing resistance R1 in parallel, and the high-power equalizing resistance in parallel at the second input filter capacitor C2 two ends R2, can correct after using this input circuit within the specific limits because of the first input filter capacitor C1 and the second input filter capacitor C2 Parameter the most strictly mates the unbalanced-voltage-division phenomenon caused.

But owing to the power of equalizing resistance R1 and equalizing resistance R2 is relatively big, in use there is electric current to cross resistance R1 and electricity Resistance R2, produces loss, thus increases the loss of changer, reduces the efficiency of changer；It addition, electric current flows through resistance produces heat Amount, the temperature exacerbating DC-DC converter raises, thus affects the reliability of DC-DC converter.

And the DC-DC converter provided in the present embodiment, on the one hand, after adding equilibrium electric capacity C3, though the first input filter Ripple electric capacity C1 and the capacity of the second input filter capacitor C2, make A point current potential deviateAlso can guarantee that two changers Input current is identical, it can be considered that the existence of equilibrium electric capacity C3 instead of equalizing resistance R1 and equalizing resistance R2；The opposing party Face, the equilibrium electric capacity set up is only energy-storage travelling wave tube, and the energy being stored in equilibrium electric capacity C3 can be reused, and does not increase Add the loss of changer, will not substantially aggravate the temperature rise of DC-DC converter, therefore improve the reliability of DC-DC converter.

Embodiment two

First input filter capacitor C1 and the second input filter electricity in the DC-DC converter that this utility model embodiment provides The capacity holding C2 is determined by driving supply voltage and the output of DC-DC converter, is high direct voltage when driving supply voltage Time, the span of the first input filter capacitor C1 and the second input filter capacitor C2 is between 0.1 μ F～1.0 μ F；Otherwise, when When driving power supply is AC rectification pulsafeeder, the first input filter capacitor C1 and the span of the second input filter capacitor C2 Between 10 μ F to hundreds of μ F；The amount of capacity of equilibrium electric capacity C3 and the first input filter capacitor C1, the second input filter capacitor Far between C2, value between 1nF～10nF, the pressure and maximum driving supply voltage of equilibrium electric capacity C3 Relevant, work as V_INWhen the upper limit is 1500V, the pressure optional 200V of equilibrium electric capacity C3.Above-mentioned value is not done specifically by the present embodiment Limit, as long as disclosure satisfy that all pressure current-sharing effects.

A kind of DC-DC converter that the present embodiment provides is illustrated in figure 5 input series and output parallel double-transistor flyback DC-DC The concrete structure of changer, including driving power supply, the first changer, the second changer, the first input filter capacitor, the second input Filter capacitor and equilibrium electric capacity, wherein, the first changer, the second changer are double-transistor flyback changer, around group mark in figure The position phase antirepresentation double-transistor flyback of "●", it is relative to prior art, is additionally arranged equilibrium electric capacity C3, removes in input circuit Equalizing resistance R1 and equalizing resistance R2, double-transistor flyback changer and output circuit be all identical with shown in Fig. 1 of the prior art, The present embodiment no longer repeats.It should be noted that described first double-transistor flyback changer and described second double-transistor flyback Changer has separate energy storage inductor, as shown in Np1-Ns1 Yu Np2-Ns2 in Fig. 5.

Fig. 6 is the another kind of input series and output parallel double-transistor flyback DC-DC converter provided in the present embodiment, with Fig. 5 Unlike shown input series and output parallel double-transistor flyback DC-DC converter, the input series and output parallel shown in Fig. 6 is double In pipe flyback DC-DC converter, each winding of two double-transistor flyback changers is wound on the skeleton of same magnetic core, shares with once Level winding, the armature winding of the most described first double-transistor flyback changer, secondary windings and described second double-transistor flyback changer Armature winding, secondary windings are wound on same magnetic core framework, form integrated energy storage inductance, as shown in Np1-Np2-Ns in Fig. 6, defeated Go out circuit and merge into one.

It should be noted that separate inductor and integrated energy storage inductance are respectively provided with its pluses and minuses, the advantage of independent energy storage inductor It is design, makes easily, exportable bigger power, but volume is big；Integrated energy storage inductance volume is little, but design, make have one Fixed difficulty, output is the least.

Fig. 7 is a kind of input series and output parallel double tube positive exciting DC-DC converter provided in the present embodiment, including driving Power supply, the first changer, the second changer, the first input filter capacitor, the second input filter capacitor and equilibrium electric capacity, wherein, First changer, the second changer are two-transistor forward converter, two-tube just around the identical expression in the position of group mark "●" in figure Swashing, it is relative to prior art, is additionally arranged equilibrium electric capacity C3, eliminates equalizing resistance R1 and equalizing resistance in input circuit R2, two-transistor forward converter and output circuit are all identical with shown in Fig. 2 of the prior art, no longer go to live in the household of one's in-laws on getting married in the present embodiment State.It should be noted that described first two-transistor forward converter and described second two-transistor forward converter have separate Transformator, as shown in Np1-Ns1 Yu Np2-Ns2 in Fig. 7.

Fig. 8 is the another kind of input series and output parallel double tube positive exciting DC-DC converter provided in the present embodiment, with Fig. 7 Unlike shown input series and output parallel double tube positive exciting DC-DC converter, the input series and output parallel shown in Fig. 8 is double In pipe normal shock DC-DC converter, each winding of two two-transistor forward converters is wound on the skeleton of same magnetic core, shares with once Level winding, the armature winding of the most described first two-transistor forward converter, secondary windings and described second two-transistor forward converter Armature winding, secondary windings are wound on same magnetic core framework, form integrated transformer, as shown in Np1-Np2-Ns in Fig. 8, and output Circuit merges into one.

It should be noted that separate inductor and integrated transformer are respectively provided with its pluses and minuses, the advantage of separated transformer is to set Count, make easily, exportable bigger power, but volume is big；Integrated transformer volume is little, but design, make have certain difficulty Degree, output is the least.

Fig. 9 is full-bridge DC-DC converter circuit figure, including driving power supply, the first changer, the second changer, first defeated Enter filter capacitor C1, the second input filter capacitor C2 and equilibrium electric capacity C3, the connected mode of equilibrium electric capacity C3 and input before Series connection output-parallel double tube positive exciting DC-DC converter in or the connection of input series and output parallel double-transistor flyback DC-DC converter Mode is identical, and this is not elaborated by the present embodiment.Its full-bridge circuit is the most identical with prior art, and each changer includes 4 Individual switching tube (Q11-Q14 or Q21-Q24 in figure), electric capacity (C11 or C21), energy storage inductor (Np1-Ns1 or Np2-Ns2), two Output diode (D11, D12 or D21, D22), outputting inductance L, output filter capacitor E1 and output voltage Vo.

Figure 10 is half-bridge DC-DC converter circuit figure, including driving power supply, the first changer, the second changer, first defeated Enter filter capacitor C1, the second input filter capacitor C2 and equilibrium electric capacity C3, the connected mode of equilibrium electric capacity C3 and input before Series connection output-parallel double tube positive exciting DC-DC converter in or the connection of input series and output parallel double-transistor flyback DC-DC converter Mode is identical, and this is not elaborated by the present embodiment.Relative to full-bridge DC-DC converter circuit, every in half-bridge DC-DC circuit Two switching tubes of individual changer are replaced by electric capacity, and (Q12 is replaced by C12, Q14 and is replaced by C13 or Q22 and is replaced by C22, Q24 more It is changed to C23), other structures are constant, are more than replaced by what those skilled in the art were readily obtained, do not do this in detail in the present embodiment Thin description.

In all DC-DC circuit provided in the present embodiment, in input circuit, all it is additionally arranged equilibrium electric capacity C3, it is thus possible to Enough input characteristics deviations to two input filter capacitors or two changers have good portfolio effect.And this utility model carries The changer of confession, only on the basis of the input circuit of conventional converter circuits, adds an equilibrium electric capacity, simple circuit, it is simple to Batch production, and with low cost；Need not debug for other elements of circuit and can realize all pressing current-sharing effect, reliability is high.

It should be noted that each embodiment in this specification all uses the mode gone forward one by one to describe, each embodiment weight Point explanation is all the difference with other embodiments, and between each embodiment, identical similar part sees mutually.

Described above to the disclosed embodiments, makes professional and technical personnel in the field be capable of or uses this practicality new Type.Multiple amendment to these embodiments will be apparent from for those skilled in the art, is determined herein The General Principle of justice can realize in the case of without departing from spirit or scope of the present utility model in other embodiments.Cause This, this utility model is not intended to be limited to the embodiments shown herein, and is to fit to and principles disclosed herein The widest scope consistent with features of novelty.

Claims (10)

1. a DC-DC converter, it is characterised in that including:

Drive power supply, the first changer, the second changer, the first input filter capacitor, the second input filter capacitor and equilibrium electricity Hold；

The positive input terminal of described first changer is connected with the anode of described first input filter capacitor, and is connected to described driving The positive pole of power supply；

The negative input end of described first changer is connected with the positive input terminal of described second changer；

The negative input end of described second changer is connected with the negative terminal of described second input filter capacitor, and is connected to described driving The negative pole of power supply；

The negative terminal of described first input filter capacitor is connected with the anode of described second input filter capacitor；

One end of described equilibrium electric capacity connects the common port of described first input filter capacitor and described second input filter capacitor, The other end connects the common port of described first changer and described second changer.

DC-DC converter input circuit the most according to claim 1, it is characterised in that described equilibrium electric capacity is an electricity Hold.

DC-DC converter the most according to claim 1, it is characterised in that described equilibrium electric capacity includes multiple with connection in series-parallel The electric capacity that mode connects.

4. according to the DC-DC converter described in claim 1-3 any one, it is characterised in that described first changer is One two-tube anti exciting converter, described second changer is the second double-transistor flyback changer.

DC-DC converter the most according to claim 4, it is characterised in that described first double-transistor flyback changer is with described Second double-transistor flyback changer has separate energy storage inductor.

DC-DC converter the most according to claim 4, it is characterised in that the primary of described first double-transistor flyback changer Winding, secondary windings and the armature winding of described second double-transistor flyback changer, secondary windings are wound on same magnetic core framework, shape Become integrated inductor.

7. according to the DC-DC converter described in claim 1-3 any one, it is characterised in that described first changer is One two-transistor forward converter, described second changer is the second two-transistor forward converter.

DC-DC converter the most according to claim 7, it is characterised in that described first two-transistor forward converter is with described Second two-transistor forward converter has separate transformator.

DC-DC converter the most according to claim 7, it is characterised in that the primary of described first two-transistor forward converter Winding, secondary windings and the armature winding of described second two-transistor forward converter, secondary windings are wound on same magnetic core framework, shape Become integrated transformer.

10. according to the DC-DC converter described in claim 1-3 any one, it is characterised in that described first changer and institute State the second changer and be full-bridge converter or half-bridge converter.