CN203645545U - Magnetic coupling high gain DC/DC converter - Google Patents

Abstract

The utility model discloses a magnetic coupling high gain DC/DC converter. The magnetic coupling high gain DC/DC converter comprises a DC input power supply, a first inductor, a first diode, a second diode, a second inductor, a first capacitor, a switching tube, a third diode, a second capacitor, a transformer, a third capacitor, a fourth diode and an output capacitor. The DC input power supply is connected with the first inductor, the first capacitor, the switching tube, the transformer, the third capacitor, the output capacitor and a load separately, and the first inductor is connected with the first and second diodes separately. The second inductor is connected with the first diode, the switching tube, the third diode, the second capacitor, the second diode and the first capacitor separately, and the second capacitor is connected with the transformer. The third diode is connected with the transformer and the third capacitor separately, the transformer is connected with the fourth diode, and the fourth diode is connected with the output capacitor and the load separately. The magnetic coupling high gain DC/DC converter of the utility model enables a low-grade voltage to be lifted to a high-grade voltage by just needing a smaller duty ratio and on the condition of the same input voltage and output voltage.

Description

A kind of magnetic coupling type high-gain DC/DC converter

Technical field

The utility model relates to the technical field of DC/DC converter, refers in particular to a kind of magnetic coupling type high-gain DC/DC converter.

Background technology

Known in the industry, in renewable energy system, most regenerative resource is all low-grade direct voltage as the outputs such as solar energy, wind energy and fuel cell, if want grid-connected, need to use the converter of high-gain is high voltage by low voltage transition.But traditional non-isolation type DC/DC converter is subject to the restriction of duty ratio and parasitic parameter, cannot realize significantly and boosting; And with the isolated form DC/DC converter of transformer, though can utilize the transformer turn ratio to realize high-gain, some application scenario does not need input/output terminal mutually to isolate, and the control more complicated of isolated converter.

Summary of the invention

The purpose of this utility model is to overcome the deficiencies in the prior art, a kind of reliable, superior performance rational in infrastructure is provided, controls magnetic coupling type high-gain DC/DC converter easily.

For achieving the above object, technical scheme provided by the utility model is: a kind of magnetic coupling type high-gain DC/DC converter, includes direct-current input power supplying, the first inductance, the first diode, the second diode, the second inductance, the first electric capacity, switching tube, the 3rd diode, the second electric capacity, transformer, the 3rd electric capacity, the 4th diode, output capacitance; Wherein, one end of described direct-current input power supplying is connected with one end of the first inductance, and its other end is connected with one end of the first electric capacity, the drain electrode of switching tube, the different name end of transformer primary side, one end of the 3rd electric capacity, one end of output capacitance, one end of load respectively; The other end of described the first inductance respectively with the anode of the first diode and the anodic bonding of the second diode; One end of described the second inductance is connected with the negative electrode of the first diode, the drain electrode of switching tube, the anode of the 3rd diode, one end of the second electric capacity respectively, and its other end is connected with the negative electrode of the second diode and the other end of the first electric capacity respectively; The other end of described the second electric capacity is connected with the Same Name of Ends of transformer primary side; The negative electrode of described the 3rd diode is connected with the different name end of transformer secondary and the other end of the 3rd electric capacity respectively; The anodic bonding of the Same Name of Ends of described transformer secondary and the 4th diode; The negative electrode of described the 4th diode is connected with the other end of output capacitance and the other end of load respectively; Described output capacitance and load parallel connection.

The turn ratio of described transformer T is 1:n.

Compared with prior art, tool has the following advantages and beneficial effect the utility model:

1, than traditional Flyback, Forward and Full-bridge DC/DC converter, in the case of identical duty ratio and input voltage, the utlity model has higher output voltage.

2, under identical input voltage and output voltage condition, the utility model circuit only needs less duty ratio just inferior grade voltage can be risen to high-grade voltage, and operating efficiency is high, and therefore the utility model circuit has application prospect very widely.

Brief description of the drawings

Fig. 1 is circuit theory diagrams of the present utility model.

Fig. 2 is the voltage and current waveform of a switch periods main element.

Fig. 3 a is one of circuit mode figure in a switch periods.

Fig. 3 b is two of the interior circuit mode figure of a switch periods.

Fig. 3 c is three of the interior circuit mode figure of a switch periods.

Fig. 4 is the V of the utility model, Flyback and Forward converter _o/ V _inthe oscillogram changing with duty ratio D.

Embodiment

Below in conjunction with specific embodiment, the utility model is described in further detail.

Shown in Figure 1, the magnetic coupling type high-gain DC/DC converter described in the present embodiment, includes direct-current input power supplying, the first inductance L ₁, the first diode D ₁, the second diode D ₂, the second inductance L ₂, the first capacitor C ₁, switching tube S, the 3rd diode D ₃, the second capacitor C ₂, the turn ratio be 1:n transformer T, the 3rd capacitor C ₃, the 4th diode D ₄, output capacitance C _out; Wherein, one end of described direct-current input power supplying and the first inductance L ₁one end connect, its other end respectively with the first capacitor C ₁one end, the drain electrode of switching tube S, the different name end on the former limit of transformer T, the 3rd capacitor C ₃one end, output capacitance C _outone end of one end, load connect; Described the first inductance L ₁the other end respectively with the first diode D ₁anode and the second diode D ₂anodic bonding; Described the second inductance L ₂one end respectively with the first diode D ₁negative electrode, the drain electrode of switching tube S, the 3rd diode D ₃anode, the second capacitor C ₂one end connect, its other end respectively with the second diode D ₂negative electrode and the first capacitor C ₁the other end connect; Described the second capacitor C ₂the other end be connected with the Same Name of Ends on the former limit of transformer T; Described the 3rd diode D ₃negative electrode respectively with different name end and the 3rd capacitor C of transformer T secondary ₃the other end connect; The Same Name of Ends of described transformer T secondary and the 4th diode D ₄anodic bonding; Described the 4th diode D ₄negative electrode respectively with output capacitance C _outthe other end and the other end of load be connected; Described output capacitance C _outwith load parallel connection.

Shown in Figure 2, show the driving signal V of described switching tube S _g, the first inductance L ₁electric current I _l1, the second inductance L ₂electric current I _l2, the magnetizing inductance L of transformer T _p3and electric current I _lP3, the 3rd diode D ₃electric current I _d3, output voltage V _o, the first capacitor C ₁voltage V _c1, the second capacitor C ₂voltage V _c2, the 3rd capacitor C ₃voltage V _c3, the 3rd diode D ₃voltage V _d3at the waveform of a switch periods.

Shown in Fig. 3 a to Fig. 3 c, show the circuit mode of the utility model three phases in a switch periods, its concrete condition is as follows:

1) at t ₀～t ₁stage, as shown in Figure 3 a, the driving voltage V of switching tube S _gbecome high level from low level, switching tube S conducting, the first diode D ₁bear forward voltage conducting, DC input voitage V _inby the first diode D ₁give the first inductance L with switching tube S ₁charging; The second diode D ₂bear reverse voltage cut-off, the first capacitor C ₁give the second inductance L by switching tube S ₂charging; The second capacitor C ₂magnetizing inductance L by switching tube S to transformer T _p3charging, now electric current I _lP3with the opposite direction of regulation, the output voltage V of transformer T _o1be less than zero, the four diode D ₄with the 3rd diode D ₃bear reverse voltage cut-off, the 3rd capacitor C ₃voltage V _c3remain unchanged; Output capacitance C _outpowering load, to maintain output voltage V _oconstant.

2) at t ₁～t ₂stage, as shown in Figure 3 b, the driving voltage V of switching tube S _gbecome low level from high level, switching tube S turn-offs, the first diode D ₁bear reverse voltage cut-off, the second diode D ₂bear forward voltage conducting, DC input voitage V _inwith the first inductance L ₁give together the first capacitor C ₁charging; DC input voitage V _in, the first inductance L ₁with the second inductance L ₂give the second capacitor C ₂charging; Due to the 3rd capacitor C ₃voltage is greater than DC input voitage V _inwith the first inductance L ₁voltage V _l1sum, the 3rd diode D ₃bear reverse voltage cut-off; The magnetizing inductance L of transformer T _p3electric discharge, now electric current I _lP3identical with the direction of regulation, the output voltage V of transformer T _o1be greater than zero, the four diode D ₄bear forward voltage conducting, the 3rd capacitor C ₃start electric discharge, transformer T and the 3rd capacitor C ₃give output capacitance C _outcharging and load supplying; Until the 3rd capacitor C ₃voltage is less than DC input voitage V _inwith the first inductance L ₁voltage V _l1sum, this stage finishes.

3) at t ₂～t ₃stage, as shown in Figure 3 c, the driving voltage V of switching tube S _gbe still low level, switching tube S turn-offs, the first diode D ₁bear reverse voltage cut-off, the second diode D ₂bear forward voltage conducting, DC input voitage V _inwith the first inductance L ₁give together the first capacitor C ₁charging; DC input voitage V _in, the first inductance L ₁with the second inductance L ₂give the second capacitor C ₂charging; Now the 3rd capacitor C ₃voltage is less than DC input voitage V _inwith the first inductance L ₁voltage V _l1sum, the 3rd diode D ₃bear forward voltage conducting, DC input voitage V _in, the first inductance L ₁with the second inductance L ₂give the 3rd capacitor C ₃; The magnetizing inductance L of transformer T _p3electric discharge, now electric current I _lP3identical with the direction of regulation, the output voltage V of transformer T _o1be greater than zero, the four diode D ₄bear forward voltage conducting, DC input voitage V _in, the first inductance L ₁, the second inductance L ₂with transformer T to output capacitance C _outcharging and load supplying.

Be below the steady-state gain situation of the above-mentioned magnetic coupling type high-gain of the present embodiment DC/DC converter:

Due to the first inductance L ₁voltage V _l1a switch periods mean value is zero, therefore can obtain as shown in the formula (1), obtains input voltage V by formula (1) _inwith the first capacitor C ₁voltage V _c1relational expression is as shown in the formula (2).

V _inD＝(V _C1-V _in)(1-D) （1）

$V_{C1}=\frac{1}{1-D}{V}_{\mathrm{in}}---\left(2\right)$

Due to the second inductance L ₂voltage V _l2a switch periods mean value is zero, therefore can obtain as shown in the formula (3) and formula (4).

$V_{C1}D=(\frac{V_{O1}}{n}+V_{C2}-V_{C1})(1-D)---\left(3\right)$

V _C1D＝(V _C3-V _C1)(1-D) （4）

Due to the magnetizing inductance L of transformer T _p3voltage V _lP3a switch periods mean value is zero, therefore can obtain as shown in the formula (5), and can be obtained by formula (3) and formula (5) is as shown in the formula (6), can obtain output voltage V by formula (4) _oexpression formula as shown in the formula (7).

$V_{C2}D=\frac{V_{O1}}{n}(1-D)---\left(5\right)$

$V_{O1}=\frac{\mathrm{nD}}{1-D}{V}_{C1}---\left(6\right)$

$V_{C3}=\frac{1}{1-D}{V}_{C1}---\left(7\right)$

Due to output voltage V _oequal the output voltage V of transformer T _o1with the 3rd capacitor C ₃voltage V _c3be added, so obtain DC input voitage V by formula (2), (4), (6) _inwith output voltage V _orelational expression as shown in the formula (8).

$V_o=V_{O1}+V_{C3}=\frac{(1+\mathrm{nD})}{1-D}{V}_{C1}=\frac{(1+\mathrm{nD})}{{(1-D)}^2}---\left(8\right)$

Conventionally, tradition is with the DC/DC converter of transformer, if the steady-state gain of Flyback and Forward converter is that nD/ (1-D) and nD(D are duty ratio).As shown in Figure 4, show the steady-state gain situation of the utility model and Flyback and Forward converter, as we know from the figure, in the time that input voltage is 48V, when turn ratio n=3, duty ratio of the present utility model only needs 0.47 just can rise to 400V left and right, and this is much smaller than other two (Flyback and Forward converter) duty ratios.

The examples of implementation of the above are only the preferred embodiment of the utility model, not limit practical range of the present utility model with this, therefore the variation that all shapes according to the utility model, principle are done all should be encompassed in protection range of the present utility model.

Claims (2)

1. a magnetic coupling type high-gain DC/DC converter, is characterized in that: include direct-current input power supplying, the first inductance (L ₁), the first diode (D ₁), the second diode (D ₂), the second inductance (L ₂), the first electric capacity (C ₁), switching tube (S), the 3rd diode (D ₃), the second electric capacity (C ₂), transformer (T), the 3rd electric capacity (C ₃), the 4th diode (D ₄), output capacitance (C _out); Wherein, one end of described direct-current input power supplying and the first inductance (L ₁) one end connect, its other end respectively with the first electric capacity (C ₁) one end, the drain electrode of switching tube (S), the different name end on the former limit of transformer (T), the 3rd electric capacity (C ₃) one end, output capacitance (C _out) one end of one end, load connect; Described the first inductance (L ₁) the other end respectively with the first diode (D ₁) anode and the second diode (D ₂) anodic bonding; Described the second inductance (L ₂) one end respectively with the first diode (D ₁) negative electrode, the drain electrode of switching tube (S), the 3rd diode (D ₃) anode, the second electric capacity (C ₂) one end connect, its other end respectively with the second diode (D ₂) negative electrode and the first electric capacity (C ₁) the other end connect; Described the second electric capacity (C ₂) the other end be connected with the Same Name of Ends on the former limit of transformer (T); Described the 3rd diode (D ₃) negative electrode respectively with different name end and the 3rd electric capacity (C of transformer (T) secondary ₃) the other end connect; The Same Name of Ends of described transformer (T) secondary and the 4th diode (D ₄) anodic bonding; Described the 4th diode (D ₄) negative electrode respectively with output capacitance (C _out) the other end and the other end of load be connected; Described output capacitance (C _out) and load parallel connection.

2. a kind of magnetic coupling type high-gain DC/DC converter according to claim 1, is characterized in that: the turn ratio of described transformer (T) is 1:n.