CN205847087U - A kind of high-gain quasi-boost switching DC DC changer - Google Patents

Abstract

This utility model provides a kind of high-gain quasi-boost switching DC DC converter circuit, including voltage source, the two ends quasi-boost switching unit being made up of the first electric capacity, the first diode, the first metal-oxide-semiconductor, the 3rd diode and inductance, second metal-oxide-semiconductor, second electric capacity, the second diode, output diode, output filter capacitor and load.The whole circuit structure of this utility model is simple, combines quasi-boost switching unit and switching capacity respective single-stage boosting characteristic, it is achieved that the expansion of output voltage gain.

Description

A kind of high-gain quasi-boost switching DC-DC converter

Technical field

This utility model relates to Power Electronic Circuit technical field, is specifically related to a kind of high-gain quasi-boost switching DC-DC Converter circuit.

Background technology

In fuel cell power generation, photovoltaic generation, due to single solaode or single fuel cell provide straight Stream voltage is relatively low, it is impossible to meets the need for electricity of existing electrical equipment, can not meet grid-connected demand, generally requires multiple Battery is together in series the voltage reaching required.On the one hand this method greatly reduces the reliability of whole system, on the other hand Also need to solve series average-voltage problem.For this reason, it may be necessary to can be high-tension high-gain DC-DC converter low voltage transition.Closely The switching boost converter SBI proposed for several years is little due to the excursion of its output voltage, exports at low-voltage high input voltage Occasion, such as distributed energy grid-connected system and fuel cell system, tradition SBI changer becomes no longer to be suitable for.In order to expand The scope of application of tradition SBI changer, it is necessary to improved by topology and expand its output voltage gain.

Utility model content

The purpose of this utility model is to overcome above-mentioned the deficiencies in the prior art, it is provided that a kind of quasi-boost switching of high-gain DC-DC converter circuit, concrete technical scheme is as follows.

A kind of high-gain quasi-boost switching DC-DC converter circuit, including voltage source, by the first electric capacity, the first diode, First metal-oxide-semiconductor, the two ends quasi-boost switching unit that the 3rd diode and inductance are constituted, the second metal-oxide-semiconductor, the second electric capacity, the two or two Pole is managed, output diode, and output filter capacitor and load are constituted.

In above-mentioned a kind of high-gain quasi-boost switching DC-DC converter circuit, the positive pole of described voltage source is respectively with The negative pole of one electric capacity and the anode of the 3rd diode connect；The positive pole of described first electric capacity respectively with the negative electrode of the first diode, The drain electrode of the first metal-oxide-semiconductor and the anode of output diode connect；The source electrode of described first metal-oxide-semiconductor respectively with the moon of the 3rd diode One end of pole and inductance connects；The anode of described first diode respectively with the other end of inductance, the drain electrode of the second metal-oxide-semiconductor, The positive pole of two electric capacity connects；The negative pole of described second electric capacity respectively with anode, the negative pole of output filter capacitor of the second diode Connect with one end of load；The negative electrode of described output diode connects with the positive pole of output filter capacitor and the other end of load respectively Connect；The negative pole of described voltage source is connected with source electrode, the negative electrode of the second diode of the second metal-oxide-semiconductor respectively.

Compared with prior art, this utility model circuit has the advantage that and technique effect: the whole electricity of this utility model Line structure is simple, and easy to control, output voltage gain is higher；This utility model circuit utilizes the single-stage liter of quasi-boost switching unit Dropping voltage characteristic and switching capacity charge the characteristic of discharged in series parallel, thus increase output voltage, it is achieved that quasi-boost switching The expansion of changer output voltage gain.

Accompanying drawing explanation

Fig. 1 is a kind of high-gain quasi-boost switching DC-DC converter circuit in this utility model detailed description of the invention.

Fig. 2 a, Fig. 2 b are that a kind of high-gain quasi-boost switching DC-DC converter circuit shown in Fig. 1 is at its first switch respectively Pipe S₁With second switch pipe S₂Simultaneously turn on and simultaneously turn off the equivalent circuit diagram of period.

Fig. 3 a is gain curve and Boost, switching capacity Boost and the tradition of this utility model circuit The gain curve comparison diagram of Z source DC-DC converter.

Fig. 3 b is the gain curve of this utility model circuit and Boost, switching capacity Boost in Fig. 3 a With the gain curve of the traditional Z source DC-DC converter comparison diagram in dutycycle D is less than 0.5.

Detailed description of the invention

The technical solution of the utility model is explained in detail by above content, new to this practicality below in conjunction with accompanying drawing Being embodied as of type is further described.

With reference to Fig. 1, a kind of high-gain quasi-boost switching DC-DC converter circuit described in the utility model, including voltage Source, the two ends quasi-boost switching unit being made up of the first electric capacity, the first diode, the first metal-oxide-semiconductor, the 3rd diode and inductance, Second metal-oxide-semiconductor, the second electric capacity, the second diode, output diode D_o, output filter capacitor C_fWith load R_L.When the first metal-oxide-semiconductor S₁With the second metal-oxide-semiconductor S₂When simultaneously turning on, described first diode D₁, the second diode D₂, the 3rd diode D₃It is turned off；Described Voltage source V_iWith the first electric capacity C₁Together to inductance L charging energy-storing；Meanwhile, voltage source V_i, the first electric capacity C₁With the second electric capacity C₂One Rise output filter capacitor C_fWith load R_LPower supply.As the first metal-oxide-semiconductor S₁With the second metal-oxide-semiconductor S₂When simultaneously turning off, the described 1st Pole pipe D₁, the second diode D₂, the 3rd diode D₃It is both turned on, output diode D_oTurn off；Inductance L and the first electric capacity C₁Parallel connection, Form loop；Described voltage source Vi to the second electric capacity C2 charging, forms loop together with inductance L；Meanwhile, output filter capacitor C_f To load R_LIt is powered.Whole circuit structure is simple, has higher output voltage gain.

The positive pole of described voltage source is connected with the negative pole of the first electric capacity and the anode of the 3rd diode respectively；Described first electricity The positive pole held anode with negative electrode, the drain electrode of the first metal-oxide-semiconductor and the output diode of the first diode respectively is connected；Described first The source electrode of metal-oxide-semiconductor is connected with the negative electrode of the 3rd diode and one end of inductance respectively；The anode of described first diode respectively with The other end of inductance, the drain electrode of the second metal-oxide-semiconductor, the positive pole of the second electric capacity connect；The negative pole of described second electric capacity is respectively with second One end of the anode of diode, the negative pole of output filter capacitor and load connects；The negative electrode of described output diode is respectively with defeated The other end of the positive pole and load that go out filter capacitor connects；The negative pole of described voltage source respectively with the source electrode of the second metal-oxide-semiconductor, second The negative electrode of diode connects.

Fig. 2 a, Fig. 2 b give the process chart of this utility model circuit.Fig. 2 a, Fig. 2 b correspondence respectively is first Metal-oxide-semiconductor S₁With the second metal-oxide-semiconductor S₂Simultaneously turn on and simultaneously turn off the equivalent circuit diagram of period.Have during in figure, solid line represents changer The part that electric current flows through, dotted line represents the part that in changer, no current flows through.

Work process of the present utility model is as follows:

Stage 1, such as Fig. 2 a: the first metal-oxide-semiconductor S₁With the second metal-oxide-semiconductor S₂Simultaneously turn on, now the first diode D₁, the two or two Pole pipe D₂, the 3rd diode D₃It is turned off.Circuit defines two loops, respectively: voltage source V_iWith the first electric capacity C₁With second Electric capacity C₂Give output filter capacitor C together_fWith load R_LCharging, forms loop；Voltage source V_iWith the first electric capacity C₁Inductance L is carried out Charging energy-storing, forms loop.

Stage 2, such as Fig. 2 the b: the first metal-oxide-semiconductor S₁With the second metal-oxide-semiconductor S₂Simultaneously turn off, now the first diode D₁, the two or two Pole pipe D₂, the 3rd diode D₃It is both turned on, output diode D_oTurn off.Circuit defines three loops, respectively: voltage source V_i The second electric capacity C is given with inductance L₂Charging energy-storing, forms loop；Inductance L is to the first electric capacity C₁Charging, forms loop；Output filtered electrical Hold C_fGive load R_LPower supply, forms loop.

To sum up situation, due to the first metal-oxide-semiconductor S₁With the second metal-oxide-semiconductor S₂Switch triggering pulse identical, if switching tube S₁ And S₂Dutycycle be D, switch periods is T_s.And set V_LThe voltage at inductance L two ends, V_C1、V_C2It is respectively the first electric capacity C₁With Second electric capacity C₂Voltage, V_S1For and V_S2It is respectively the first metal-oxide-semiconductor S₁With the second metal-oxide-semiconductor S₂Voltage between drain electrode and source electrode. Switch periods T_sIn, making output voltage is V_o.After changer enters steady operation, show that following voltage relationship pushes away Lead process.

Operation mode 1: the first metal-oxide-semiconductor S₁With the second metal-oxide-semiconductor S₂Simultaneously turn on, shown in corresponding equivalent circuit diagram 2a, therefore There is an equation below:

V_L=V_i+V_C1 (1)

V_O=V_i+V_C1+V_C2 (2)

V_S1=V_S2=0 (3)

Metal-oxide-semiconductor S₁And S₂ON time be DT_s。

Operation mode 2: the first metal-oxide-semiconductor S₁With the second metal-oxide-semiconductor S₂Be turned off, corresponding equivalent circuit as shown in Figure 2 b, therefore There is an equation below:

V_L=-V_C1 (4)

V_L=V_i-V_C2 (5)

V_S2=V_i+V_C1 (6)

V_S1=V_C1 (7)

Metal-oxide-semiconductor S₁And S₂Turn-off time be (1-D) T_s。

Analyzing according to above, inductance L is used inductance Flux consumption conservation principle, simultaneous formula (1), formula (4), formula (5) can obtain:

D(V_i+V_C1)-(1-D)V_C1=0 (8)

Thus, the first electric capacity C can be drawn₁Voltage V_C1With voltage source V_iBetween relational expression be:

$V_{C1}=\frac{D}{1-2D}{V}_i---\left(9\right)$

The second electric capacity C can be obtained by formula (4) and formula (5)₂Voltage V_C2Voltage source V_iBetween relational expression be:

$V_{C2}=\frac{1-D}{1-2D}{V}_i---\left(10\right)$

Then by formula (2), formula (9) and formula (10), the gain factor expression formula that can obtain this utility model circuit is:

$G=\frac{V_o}{V_i}=\frac{2(1-D)}{1-2D}---\left(11\right)$

It is gain curve and Boost, the switching capacity Boost of this utility model circuit as shown in Figure 3 a Gain curve comparison diagram with traditional Z source DC-DC converter；Fig. 3 b be in Fig. 3 a this utility model circuit gain curve with basic The gain curve of booster circuit comparison diagram in dutycycle D is less than 0.5, figure includes that the gain of this utility model circuit is bent Line, the gain curve of traditional Z source DC-DC converter, the gain curve of switching capacity Boost, the increasing of Boost Benefit curve.As seen from the figure, this utility model circuit is in the case of dutycycle D is less than 0.5, and gain G just can reach very big, And dutycycle D of this utility model circuit is not over 0.5.Therefore, by contrast, the gain of this utility model circuit is very High.

In sum, this utility model circuit overall structure is simple, easy to control, combines quasi-boost switching unit single-stage The characteristic of buck and switching capacity charge the characteristic of discharged in series parallel, it is achieved that the further lifting of output voltage gain, And there is not inrush current and metal-oxide-semiconductor opens the dash current of moment.

Above-described embodiment is this utility model preferably embodiment, but embodiment of the present utility model is not by described The restriction of embodiment, other any without departing from the change made under spirit of the present utility model and principle, modify, replace In generation, combine, simplify, all should be the substitute mode of equivalence, within being included in protection domain of the present utility model.

Claims (1)

1. a high-gain quasi-boost switching DC-DC converter circuit, it is characterised in that include voltage source (V_i), quasi-boost switching Unit, the second metal-oxide-semiconductor (S₂), the second electric capacity (C₂) the second diode (D₂), output diode (D_o), output filter capacitor (C_f) and Load (R_L)；Described quasi-boost switching unit is by inductance (L), the first diode (D₁), the first electric capacity (C₁), the first metal-oxide-semiconductor (S₁) With the 3rd diode (D₃) constitute；

Described voltage source (V_i) positive pole respectively with the first electric capacity (C₁) negative pole and the 3rd diode (D₃) anode connect；Institute State the first electric capacity (C₁) positive pole respectively with the first diode (D₁) negative electrode, the first metal-oxide-semiconductor (S₁) drain electrode and output diode (D_o) anode connect；Described first metal-oxide-semiconductor (S₁) source electrode respectively with the 3rd diode (D₃) negative electrode and the one of inductance (L) End connects；Described first diode (D₁) anode respectively with the other end, the second metal-oxide-semiconductor (S of inductance (L)₂) drain electrode, second Electric capacity (C₂) positive pole connect；Described second electric capacity (C₂) negative pole respectively with the second diode (D₂) anode, output filtered electrical Hold (C_f) negative pole and load (R_L) one end connect；Described output diode (D_o) negative electrode respectively with output filter capacitor (C_f) positive pole and load (R_L) the other end connect；Described voltage source (V_i) negative pole respectively with the second metal-oxide-semiconductor (S₂) source Pole, the second diode (D₂) negative electrode connect.