CN205847090U - A kind of mixed type quasi-boost switching DC DC changer - Google Patents

Abstract

This utility model provides a kind of mixed type quasi-boost switching DC DC converter circuit, including voltage source, the two ends quasi-Z source unit being made up of the first inductance, the first diode, the first electric capacity, the second inductance and the second electric capacity, the quasi-boost switching unit being made up of the second electric capacity, the second diode, the first metal-oxide-semiconductor, the first diode and the second inductance, the switching capacity unit being made up of the 3rd electric capacity and the 3rd diode, second metal-oxide-semiconductor, output diode, output filter capacitor and load.This utility model circuit structure is simple, combines the single-stage buck characteristic of quasi-Z source unit and quasi-boost switching unit and switching capacity charges the characteristic of discharged in series parallel, it is achieved that the lifting of output voltage gain.

Description

A kind of mixed type quasi-boost switching DC-DC converter

Technical field

This utility model relates to Power Electronic Circuit technical field, is specifically related to one and combines switching capacity and quasi-Z source list The mixed type high-gain quasi-boost switching DC-DC converter circuit of unit.

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 Z source converter proposed for several years and switching boost converter SBI are the DC-DC converter of high-gain, but at some low electricity Pressure input wishes that the occasion that higher voltage exports, traditional Z source converter and SBI changer just become to be no longer able to meet to want Ask.In order to expand traditional Z source converter and the scope of application of SBI changer, it is necessary to improved by topology and expand its output electricity Pressure 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 one combines switching capacity and standard The mixed type high-gain quasi-boost switching DC-DC converter circuit of Z source unit, concrete technical scheme is as follows.

A kind of mixed type quasi-boost switching DC-DC converter circuit, including voltage source, quasi-Z source unit, quasi-boost switching list Unit, the second metal-oxide-semiconductor, switching capacity unit, output diode, output filter capacitor and load.Described quasi-Z source unit is by the first electricity Sense, the first electric capacity, the first diode, the second inductance and the second electric capacity are constituted；Described quasi-boost switching unit by the second inductance, One diode, the second electric capacity, the first metal-oxide-semiconductor and the second diode are constituted；Described switching capacity unit is by the 3rd electric capacity and the 3rd Diode is constituted.

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

When the first metal-oxide-semiconductor and the second metal-oxide-semiconductor simultaneously turn on, described first diode, the second diode, the 3rd diode Being turned off, voltage source and the first electric capacity are to the first induction charging；Voltage source and the second electric capacity are to the second induction charging；Meanwhile, electricity Potential source together with the 3rd electric capacity and the second electric capacity to output filter capacitor and load supplying.When the first metal-oxide-semiconductor and the second metal-oxide-semiconductor are same Time when turning off, described first diode, the second diode, the 3rd diode be both turned on, and output diode turns off.Described second electricity Feel in parallel with the first electric capacity, form loop；Second electric capacity is charged together with the second inductance by described first inductance；Described voltage Source, the first inductance and the second inductance give the 3rd electric capacity charging；Meanwhile, output filter capacitor powering load.

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 make use of quasi-Z source unit and quasi-switch to rise The pressure single-stage buck characteristic of unit and switching capacity charge the characteristic of discharged in series parallel, thus improve output further Voltage, it is achieved that the expansion of quasi-switching boost converter output voltage gain.

Accompanying drawing explanation

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

Fig. 2 a, Fig. 2 b are the mixed type high-gain quasi-switch of a kind of combination switching capacity and quasi-Z source unit shown in Fig. 1 respectively Boost DC-DC converter circuit is at its first switching tube S₁With second switch pipe S₂Simultaneously turn on and simultaneously turn off the equivalence of period Circuit diagram.

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

Fig. 3 b is the gain curve of this utility model circuit and Boost, switching capacity Boost conversion in Fig. 3 a The gain curve of device, traditional Z source DC-DC converter and novel quasi-Z source DC-DC converter ratio in dutycycle D is less than 0.38 Relatively scheme.

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 mixed type quasi-boost switching DC-DC converter circuit described in the utility model, including voltage Source, quasi-Z source unit, quasi-boost switching unit, the second metal-oxide-semiconductor, switching capacity unit, output diode, output filter capacitor and Load.Described quasi-Z source unit is made up of the first inductance, the first electric capacity, the first diode, the second inductance and the second electric capacity；Described Quasi-boost switching unit is made up of the second inductance, the first diode, the second electric capacity, the first metal-oxide-semiconductor and the second diode；Described open Close capacitor cell to be made up of the 3rd electric capacity and the 3rd diode.

The concrete connected mode of this utility model circuit is as follows: the positive pole of described voltage source respectively with the negative pole of the second electric capacity Connect with one end of the first inductance；The other end of described first inductance negative with the anode of the first diode and the first electric capacity respectively Pole connects；The positive pole of described second electric capacity respectively with the negative electrode of the second diode, the anode of output diode and the first metal-oxide-semiconductor Drain electrode connects；The negative electrode of described first diode is connected with one end of the second inductance and the source electrode of the first metal-oxide-semiconductor respectively；Described The positive pole of one electric capacity respectively with anode, the other end of the second inductance, the drain electrode of the second metal-oxide-semiconductor and the 3rd electric capacity of the second diode Positive pole connect；The negative electrode of described output diode is connected with the positive pole of output filter capacitor and the other end of load respectively；Institute State the negative pole of the 3rd electric capacity other end respectively with anode, the negative pole of output filter capacitor and the load of the 3rd diode to be connected； The negative pole of described voltage source is connected with source electrode, the negative electrode of the 3rd diode of the second metal-oxide-semiconductor respectively.

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 three loops, respectively: voltage source V_iWith the first electric capacity C₁With the 3rd Electric capacity C₃Give output filter capacitor C together_fWith load R_LCharging, forms loop；Voltage source V_iWith the first electric capacity C₁To the first inductance L₁It is charged energy storage, forms loop；Voltage source V_iWith the second electric capacity C₂To the second inductance L₂It is charged energy storage, 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 four loops, respectively: voltage source V_i、 First inductance L₁With the second inductance L₂To the 3rd electric capacity C₃Charging energy-storing, forms loop；Second inductance L₂To the first electric capacity C₁Charging, Form loop；First inductance L₁With the second inductance L₂To the second electric capacity C₂Charging energy-storing, forms loop；Output filter capacitor 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_L1And V_L2It is respectively inductance L₁And L₂The voltage at two ends, V_C1、V_C2With V_C3It is respectively the first electric capacity C₁, the second electric capacity C₂With the 3rd electric capacity C₃Voltage, V_S1For and V_S2It is respectively the first metal-oxide-semiconductor S₁With Two metal-oxide-semiconductor S₂Voltage between drain electrode and source electrode.Switch periods T_sIn, making output voltage is V_o.When changer enters steady After state work, draw following voltage relationship derivation.

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_L1=V_i+V_C1 (1)

V_L2=V_i+V_C2 (2)

V_O=V_i+V_C3+V_C2 (3)

V_S1=V_S2=0 (4)

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_L1=V_C1-V_C2 (5)

V_L2=-V_C1 (6)

V_i=V_C3-V_C2 (7)

V_S2=V_C3 (8)

V_S1=V_C1 (9)

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

Analyze according to above, the first inductance L1 and the second inductance L2 is used inductance Flux consumption conservation principle, simultaneous respectively Formula (1), formula (5), formula (2) and formula (6) can obtain:

D(V_i+V_C1)+(1-D)(V_C1-V_C2)=0 (10)

D(V_i+V_C2)-(1-D)V_C1=0 (11)

Thus, the first electric capacity C can be drawn₁Voltage V_C1With the second electric capacity C₂Voltage V_C2Voltage and voltage source V_iBetween Relational expression is:

$V_{C1}=\frac{D}{1-3D+D^2}{V}_i---\left(12\right)$

$V_{C2}=\frac{D(2-D)}{1-3D+D^2}{V}_i---\left(13\right)$

The 3rd electric capacity C can be obtained by formula (7), formula (12) and formula (13)₃Voltage V_C3With voltage source V_iBetween relation Formula is:

$V_{C3}=\frac{1-D}{1-3D+D^2}{V}_i---\left(14\right)$

Then by formula (3), formula (13) and formula (14), the gain factor expression formula that can obtain this utility model circuit is:

$G=\frac{V_o}{V_i}=\frac{2(1-D)}{1-3D+D^2}---\left(15\right)$

It is gain curve and Boost, the switching capacity Boost conversion of this utility model circuit as shown in Figure 3 a Device, traditional Z source DC-DC converter and the gain curve comparison diagram of novel quasi-Z source DC-DC converter；Fig. 3 b is this reality in Fig. 3 a By the gain curve of novel circuit and Boost, switching capacity Boost, traditional Z source DC-DC converter and new The gain curve of type quasi-Z source DC-DC converter comparison diagram in dutycycle D is less than 0.38, figure includes this utility model electricity The gain curve on road, the gain curve of traditional Z source DC-DC converter, the gain curve of novel quasi-Z source DC-DC converter, switch The gain curve of electric capacity Boost, the gain curve of Boost.As seen from the figure, this utility model circuit is at duty Than D less than in the case of 0.38, gain G just can reach very greatly, and dutycycle D of this utility model circuit not over 0.38.Therefore, by contrast, the gain of this utility model circuit is the highest.

In sum, this utility model circuit overall structure is simple, easy to control, combines quasi-Z source unit and quasi-switch The single-stage buck characteristic of boosting unit and switching capacity charge the characteristic of discharged in series parallel, it is achieved that output voltage gain Further lifting, 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 mixed type quasi-boost switching DC-DC converter circuit, it is characterised in that include voltage source (V_i), quasi-Z source unit, Quasi-boost switching unit, the second metal-oxide-semiconductor (S₂), switching capacity unit, output diode (D_o), output filter capacitor (C_f) and negative Carry (R_L)；Described quasi-Z source unit is by the first inductance (L₁), the first electric capacity (C₁), the first diode (D₁), the second inductance (L₂) and the Two electric capacity (C₂) constitute；Described quasi-boost switching unit is by the second inductance (L₂), the first diode (D₁), the second electric capacity (C₂), One metal-oxide-semiconductor (S₁) and the second diode (D₂) constitute；Described switching capacity unit is by the 3rd electric capacity (C₃) and the 3rd diode (D₃) Constitute；

Described voltage source (V_i) positive pole respectively with the second electric capacity (C₂) negative pole and the first inductance (L₁) one end connect；Described First inductance (L₁) the other end respectively with the first diode (D₁) anode and the first electric capacity (C₁) negative pole connect；Described Two electric capacity (C₂) positive pole respectively with the second diode (D₂) negative electrode, output diode (D_o) anode and the first metal-oxide-semiconductor (S₁) Drain electrode connect；Described first diode (D₁) negative electrode respectively with the second inductance (L₂) one end and the first metal-oxide-semiconductor (S₁) source Pole connects；Described first electric capacity (C₁) positive pole respectively with the second diode (D₂) anode, the second inductance (L₂) the other end, Second metal-oxide-semiconductor (S₂) drain electrode and the 3rd electric capacity (C₃) positive pole 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 3rd electric capacity (C₃) negative pole respectively with the three or two pole Pipe (D₃) anode, output filter capacitor (C_f) negative 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 electrode, the 3rd diode (D₃) negative electrode connect.