CN203872055U - Continuous-current high-gain DC-DC converter circuit - Google Patents

Abstract

The utility model provides a continuous-current high-gain DC-DC converter circuit comprising a voltage source, a first inductor, a first diode, a first capacitor, a dual-end impedance network, a third diode, a MOS tube, a fourth inductor, an output capacitor and a load, wherein the dual-end impedance network is composed of a second inductor, a third inductor, a second capacitor, a third capacitor and a second diode. The voltage source, the first inductor, the third diode and the MOS tube are sequentially connected in series to form a first-stage boost circuit. The first capacitor, the dual-end impedance network and the MOS tube are sequentially connected in series to form a second-stage boost circuit. The fourth inductor, the output capacitor and the load form an output circuit. The continuous-current high-gain DC-DC converter circuit is simple in overall circuit structure, uses only one MOS tube, and has high output voltage gain. The power supply current is continuous, the load current is continuous, output and input are common-grounded, the voltage stress on the capacitors in the dual-end impedance network is low, and the circuit does not have starting impact current and impact current at the moment of MOS tube switching-on.

Description

A kind of current continuity type high-gain DC-DC converter circuit

Technical field

The utility model relates to Power Electronic Circuit technical field, is specifically related to a kind of current continuity type high-gain DC-DC converter circuit.

Background technology

In fuel cell power generation, photovoltaic generation, the direct voltage providing due to single solar cell or single fuel cell is lower, cannot meet the need for electricity of existing power consumption equipment, can not meet grid-connected demand, often need a plurality of batteries to be together in series and to reach required voltage.This method greatly reduces the reliability of whole system on the one hand, also needs on the other hand to solve series average-voltage problem.For this reason, needing to be high-tension high-gain DC-DC converter low voltage transition.The Z source boost DC-DC converter proposing is in recent years a kind of high-gain DC-DC converter, but this circuit has higher impedance network capacitance voltage stress, source current is discontinuous, output and input are not altogether, and during circuit start, there is very large inrush current problem, limited the application in practice of this circuit.

Utility model content

The purpose of this utility model is to overcome above-mentioned the deficiencies in the prior art, and a kind of current continuity type high-gain DC-DC converter circuit is provided, and concrete technical scheme is as follows.

A current continuity type high-gain DC-DC converter circuit, comprises voltage source, the first inductance, the first diode, the first electric capacity, two ends impedance network, the 3rd diode, metal-oxide-semiconductor, the 4th inductance, output capacitance and load.Described two ends impedance network consists of the second inductance, the 3rd inductance, the second electric capacity, the 3rd electric capacity and the second diode; Described voltage source, the first inductance, the 3rd diode and metal-oxide-semiconductor are followed in series to form first order booster circuit; Described the first electric capacity, two ends impedance network and metal-oxide-semiconductor are followed in series to form second level booster circuit; Described the 4th inductance, output capacitance and load form output circuit.

Preferably, the positive pole of described voltage source is connected with one end of the first inductance; The other end of described the first inductance respectively with the anode of the first diode and the anodic bonding of the 3rd diode; The negative electrode of described the first diode is connected with the negative pole of the second electric capacity with the positive pole of the first electric capacity, one end of the second inductance respectively; The other end of described the second inductance is connected with the negative pole of the 3rd electric capacity with the anode of the second diode respectively; The negative electrode of described the second diode is connected with one end of the 3rd inductance with the positive pole of the second electric capacity respectively; The positive pole of described the 3rd electric capacity is connected with one end of the 4th inductance with the other end, the 3rd negative electrode of diode, the drain electrode of metal-oxide-semiconductor of the 3rd inductance respectively; The other end of described the 4th inductance is connected with the positive pole of output capacitance and one end of load respectively; The negative pole of described voltage source respectively with the negative pole of the first electric capacity, the other end of the negative pole of output capacitance, load and the source electrode of metal-oxide-semiconductor be connected.

Compared with prior art, the utility model circuit tool has the following advantages and technique effect: whole circuit structure is simple, and voltage gain is higher, the in the situation that of identical input voltage, export identical voltage even more during high voltage, in the impedance network of two ends, the voltage stress of electric capacity has reduced on the contrary; Inrush current is had to good inhibitory action, and metal-oxide-semiconductor is opened moment, and output capacitance can not produce impulse current to metal-oxide-semiconductor yet, and reliability improves; And input power current continuity, load current is continuous, exports and inputs altogether, thereby be more suitable for being applied to the generation of electricity by new energy technical fields such as fuel cell power generation and photovoltaic generation.

Accompanying drawing explanation

Fig. 1 is a kind of current continuity type high-gain DC-DC converter circuit in the utility model embodiment.

Fig. 2 a, Fig. 2 b are respectively that a kind of current continuity type high-gain DC-DC converter circuit shown in Fig. 1 is at the equivalent circuit diagram of its metal-oxide-semiconductor S turn-on and turn-off period.

Fig. 3 a is the gain curve of the utility model circuit and the comparison diagram of the gain curve of basic booster circuit.

Fig. 3 b is that the gain curve of the utility model circuit in Fig. 3 a is less than the comparison diagram in 0.4 with the gain curve of basic booster circuit at duty ratio d.

Fig. 4 be in the impedance network of two ends the voltage of electric capacity and the ratio of output voltage with the situation of change of duty ratio d.

Fig. 5 is the groundwork oscillogram of current continuity type high-gain DC-DC converter circuit in example.

Embodiment

Below in conjunction with accompanying drawing, concrete enforcement of the present utility model is further described.

With reference to figure 1, a kind of current continuity type high-gain DC-DC converter circuit described in the utility model, it comprises voltage source V _i, the first inductance L ₁, the first diode D ₁, the first capacitor C ₁, by the second inductance L ₂, the 3rd inductance L ₃, the second capacitor C ₂, the 3rd capacitor C ₃with the second diode D ₂the two ends impedance network (as shown in dotted line frame in Fig. 1) forming, the 3rd diode D ₃, metal-oxide-semiconductor S, the 4th inductance L ₄, output capacitance C _owith load R _l.Described voltage source V _i, the first inductance L ₁, the 3rd diode D ₃be followed in series to form first order booster circuit with metal-oxide-semiconductor; Described the first capacitor C ₁, two ends impedance network and metal-oxide-semiconductor S be followed in series to form second level booster circuit; Described the 4th inductance L ₄, output capacitance C _owith load R _lform output circuit.During metal-oxide-semiconductor S conducting, described voltage source V _ito the first inductance L ₁charging energy-storing; Described the first capacitor C ₁with the second capacitor C ₂together to the 3rd inductance L ₃charging energy-storing; Described the first capacitor C ₁with the 3rd capacitor C ₃together to the second inductance L ₂charging energy-storing; Meanwhile, the first capacitor C ₁with electric capacity, the 4th inductance L in the impedance network of two ends ₄give together output capacitance C _owith load R _lpower supply.When metal-oxide-semiconductor S turn-offs, described the first diode D ₁with the second diode D ₂all conductings, described voltage source V _iwith the first inductance L ₁give the first capacitor C ₁charging energy-storing, forms loop; The second inductance L ₂with the second capacitor C ₂parallel connection, forms loop; The 3rd inductance L ₃with the 3rd capacitor C ₃parallel connection, forms loop; Meanwhile, voltage source V _iwith the first inductance L ₁, the inductance in the impedance network of two ends is together to the 4th inductance L ₄, output capacitance C _owith load R _lpower supply, forms loop.Whole circuit structure is simple, only used a metal-oxide-semiconductor, there is higher output voltage gain, source current is continuous, load current is continuous, export and input altogether, and the capacitance voltage stress in the impedance network of two ends is low, circuit does not exist starting current to impact and metal-oxide-semiconductor is opened the current impact of moment.

The concrete connection of circuit shown in Fig. 1 is as follows: the positive pole of described voltage source is connected with one end of the first inductance; The other end of described the first inductance respectively with the anode of the first diode and the anodic bonding of the 3rd diode; The negative electrode of described the first diode is connected with the negative pole of the second electric capacity with the positive pole of the first electric capacity, one end of the second inductance respectively; The other end of described the second inductance is connected with the negative pole of the 3rd electric capacity with the anode of the second diode respectively; The negative electrode of described diode is connected with one end of the 3rd inductance with the positive pole of the second electric capacity respectively; The positive pole of described the 3rd electric capacity is connected with one end of the 4th inductance with the other end, the 3rd negative electrode of diode, the drain electrode of metal-oxide-semiconductor of the 3rd inductance respectively; The other end of described the 4th inductance divides with the positive pole of output capacitance and one end of load and is connected; The negative pole of described voltage source respectively with the negative pole of the first electric capacity, the other end of the negative pole of output capacitance, load and the source electrode of metal-oxide-semiconductor be connected.

Fig. 2 a, Fig. 2 b have provided the process chart of the utility model circuit.Fig. 2 a, Fig. 2 b are respectively the metal-oxide-semiconductor S equivalent circuit diagrams of turn-on and turn-off period, and in figure, solid line represents the part that has electric current to flow through in converter, and dotted line represents the part that in converter, no current flows through.

The course of work of the present utility model is as follows:

Stage 1, as Fig. 2 a:MOS pipe S conducting, now the 3rd diode D ₃conducting, the first diode D ₁with the second diode D ₂all turn-off.Circuit has formed four loops, respectively: voltage source V _ito the first inductance L ₁charging energy-storing, forms loop; The first capacitor C ₁with the 3rd capacitor C ₃together to the second inductance L ₂carry out charging energy-storing, form loop; The first capacitor C ₁with the second capacitor C ₂together to the 3rd inductance L ₃carry out charging energy-storing, form loop; The first capacitor C ₁with electric capacity, the 4th inductance L in the impedance network of two ends ₄together to output capacitance C _owith load R _lpower supply, forms loop.

In the stage 2, as Fig. 2 b:MOS pipe, S turn-offs, now the 3rd diode D ₃turn-off the first diode D ₁with diode D ₂conducting.Circuit has formed four loops, respectively: voltage source V _iwith the first inductance L ₁give the first capacitor C ₁charging energy-storing, forms loop; The second inductance L ₂to the second capacitor C ₂charging, forms loop; The 3rd inductance L ₃to the 3rd capacitor C ₃charging, forms loop; Voltage source V _iwith the first inductance L ₁, the inductance in the impedance network of two ends is together to the 4th inductance L ₄, output capacitance C _owith load R _lpower supply, forms loop.

Situation to sum up, the duty ratio of establishing metal-oxide-semiconductor S is d, switch periods is T _s.Due to the symmetry of two ends impedance network, i.e. the second inductance L ₂with the 3rd inductance L ₃inductance value equate, the second capacitor C ₂with the 3rd capacitor C ₃capacitance equate.Therefore, there is v _l2=v _l3=v _l, V _c2=V _c3=V _c.V _l2, v _l3, V _c2and V _c3it is respectively the second inductance L ₂, the 3rd inductance L ₃, the second capacitor C ₂with the 3rd capacitor C ₃voltage, and set v _land V _cbe respectively two ends impedance network inductive drop and capacitance voltage, v _l1and v _l4be respectively the first inductance L ₁with the 4th inductance L ₃voltage, V _c1it is the first capacitor C ₁voltage, V _sfor the voltage between metal-oxide-semiconductor S drain electrode and source electrode.At a switch periods T _sin, making output voltage is V _o.When converter enters after steady operation, draw following voltage relationship derivation.

Metal-oxide-semiconductor S conduction period, the operative scenario described in the corresponding stage 1, therefore has following formula:

v _L1＝V _i (1)

v _L2＝v _L＝V _C1+V _C3＝V _C1+V _C (2)

v _L3＝v _L＝V _C1+V _C2＝V _C1+V _C (3)

v _L4＝-V _o (4)

Metal-oxide-semiconductor S ON time is dT _s.

Metal-oxide-semiconductor S blocking interval, the operative scenario described in the corresponding stage 2, therefore has following formula:

v _L1＝V _i-V _C1 (5)

v _L2＝v _L＝-V _C2＝-V _C (6)

v _L3＝v _L＝-V _C3＝-V _C (7)

V _S＝V _C1-v _L+V _C＝V _C1+2V _C (8)

v _L4＝V _S-V _o＝V _C1+2V _C-V _o (9)

The metal-oxide-semiconductor S turn-off time is (1-d) T _s.

According to above analysis, to inductance L ₁use and inductance weber count conservation principle, simultaneous formula (1) and formula (5) can obtain:

V _idT _s+(V _i-V _C1)(1-d)T _s＝0 (10)

Thereby, can draw the first capacitor C ₁voltage V _c1with voltage source V _ibetween relational expression be:

$V_{C1}=\frac{1}{1-d}{V}_i---\left(11\right)$

Then, according to the symmetry of two ends impedance network and inductance weber, count conservation principle, simultaneous formula (2), (3), (6) and (7), can obtain:

(V _C1+V _C)dT _s+(-V _C)(1-d)T _s＝0 (12)

Therefore,, according to formula (11) and formula (12), can obtain the voltage V of electric capacity in the impedance network of two ends _cwith voltage source V _irelational expression be:

$V_C=\frac{d}{(1-d)(1-2d)}{V}_i---\left(13\right)$

Convolution (4), (8) and (9), and to the 4th inductance L ₄inductance weber is counted conservation principle in application, can obtain:

(-V _o)dT _s+(V _C1+2V _C-V _o)(1-d)T _s＝0 (14)

By formula (11) formula (13), the gain factor expression formula that can obtain the utility model circuit is again:

$G=\frac{V_o}{V_i}=\frac{1}{1-2d}---\left(15\right)$

Be the comparison diagram of the gain curve of the utility model circuit and the gain curve of basic booster circuit as shown in Figure 3 a; Fig. 3 b is that in Fig. 3 a, the utility model circuit gain curve is less than the comparison diagram in 0.4 with the gain curve of basic booster circuit at duty ratio d, and in figure, solid line represents the gain curve of the utility model circuit, and dotted line represents the gain curve of basic booster circuit.As seen from the figure, the utility model circuit is in the situation that duty ratio d is no more than 0.5, and it is very large that gain G just can reach, and the duty ratio d of the utility model circuit can not surpass 0.5.Therefore, by contrast, the gain of the utility model circuit is very high.

By formula (13) and formula (15), can obtain the voltage V of electric capacity in the impedance network of the utility model circuit two ends _cwith output voltage V _orelational expression be:

$V_C=\frac{d}{1-d}{V}_o---\left(16\right)$

As Fig. 4 has provided the situation that in the impedance network of two ends, the voltage of electric capacity and the ratio of output voltage change with duty ratio d.The voltage V of electric capacity in the impedance network of the utility model circuit two ends as seen from the figure _cmaximum can not surpass output voltage V _o, thereby make the voltage stress of electric capacity in the impedance network of the utility model circuit two ends lower.

Main oscillogram while being illustrated in figure 5 the utility model circuit working, V in figure _gfor the driving of metal-oxide-semiconductor, i _l1, i _l2, i _l3and i _l4be respectively the first inductance L ₁, the second inductance L ₂, the 3rd inductance L ₃with the 4th inductance L ₄electric current.Due to inductance L ₁electric current be source current, inductance L ₄electric current be load current, so as can be seen from Figure, source current and load current are all continuous.

In addition, due to the topological structure of the utility model circuit own, when it starts, the first inductance L ₁with the second inductance L in the impedance network of two ends ₂with the 3rd inductance L ₃inrush current is had to inhibitory action, be conducive to the soft start of converter, reduced the impact damage to device; In like manner, due to the 4th inductance L ₄existence, so open moment when metal-oxide-semiconductor, output capacitance can not produced into impulse current to metal-oxide-semiconductor.

In sum, the utility model circuit has higher voltage gain, has only used a metal-oxide-semiconductor, source current is continuous, and load current is continuous, and output and input are altogether, in the impedance network of two ends, the voltage stress of electric capacity is low, and does not exist inrush current and metal-oxide-semiconductor to open the impulse current of moment.

Above-described embodiment is preferably execution mode of the utility model; but execution mode of the present utility model is not limited by the examples; other any do not deviate from change, the modification done under Spirit Essence of the present utility model and principle, substitutes, combination, simplify; all should be equivalent substitute mode, within being included in protection range of the present utility model.

Claims (2)

1. a current continuity type high-gain DC-DC converter circuit, is characterized in that comprising voltage source (V _i), the first inductance (L ₁), the first diode (D ₁), the first electric capacity (C ₁), two ends impedance network, metal-oxide-semiconductor (S), the 4th inductance (L ₄), output capacitance (C _o) and load (R _l); Described two ends impedance network is by the second inductance (L ₂), the 3rd inductance (L ₃), the second electric capacity (C ₂), the 3rd electric capacity (C ₃) and the second diode (D ₂) form; Described voltage source (V _i), the first inductance (L ₁), the 3rd diode (D ₃) and metal-oxide-semiconductor (S) be followed in series to form first order booster circuit; Described the first electric capacity (C ₁), two ends impedance network and metal-oxide-semiconductor (S) be followed in series to form second level booster circuit; Described the 4th inductance (L ₄), output capacitance (C _o) and load (R _l) formation output circuit.

2. a kind of current continuity type high-gain DC-DC converter circuit according to claim 1, is characterized in that described voltage source (V _i) positive pole and the first inductance (L ₁) one end connect; Described the first inductance (L ₁) the other end respectively with the first diode (D ₁) anode and the 3rd diode (D ₃) anodic bonding; Described the first diode (D ₁) negative electrode respectively with the first electric capacity (C ₁) positive pole, the second inductance (L ₂) one end and the second electric capacity (C ₂) negative pole connect; Described the second inductance (L ₂) the other end respectively with the second diode (D ₂) anode and the 3rd electric capacity (C ₃) negative pole connect; Described the second diode (D ₂) negative electrode respectively with the second electric capacity (C ₂) positive pole and the 3rd inductance (L ₃) one end connect; Described the 3rd electric capacity (C ₃) positive pole respectively with the 3rd inductance (L ₃) the other end, the 3rd diode (D ₃) negative electrode, drain electrode and the 4th inductance (L of metal-oxide-semiconductor (S) ₄) one end connect; Described the 4th inductance (L ₄) the other end respectively with output capacitance (C _o) positive pole and load (R _l) one end connect; Described voltage source (V _i) negative pole respectively with the first electric capacity (C ₁) negative pole, output capacitance (C _o) negative pole, load (R _l) the other end be connected with the source electrode of metal-oxide-semiconductor (S).