CN1315249C

CN1315249C - Combined DC/DC booster converter

Info

Publication number: CN1315249C
Application number: CNB2004100690412A
Authority: CN
Inventors: 王玉富; 马兴凯; 陶晓蜂
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-07-16
Filing date: 2004-07-16
Publication date: 2007-05-09
Anticipated expiration: 2024-07-16
Also published as: CN1588772A

Abstract

The present invention relates to a combined direct current/direct current boost converter which belongs to the technical field of direct current conversion. The present invention comprises a shared main boost inductor, a switching tube, a Boost circuit and a Cuk circuit, wherein the shared boost inductor and the switching tube are used for the Boost circuit and the Cuk circuit; the Boost circuit is used for carrying out forward voltage boost and energy storage for the voltage of the main driving point of a converter circuit so as to generate the voltage of the positive electrode point of the output power supply of the converter; the Cuk circuit is used for carrying out backward voltage boost and energy storage for the voltage of the main driving point of the converter circuit so as to generate the voltage of the negative electrode point of the output power of the converter. The boost converter provided by the present invention has a simple circuit. The shared main boost pump of the circuit is composed of the main boost inductor and the boost switching tube. Under the driving of the shared main boost pump, the Boost circuit gives voltage gains, and the Cuk unit gives voltage gains. The stable coefficient W of the converter is 0.0095 and is improved by approximately one times. Meanwhile, the voltage stress of a power tube is greatly reduced.

Description

Combined DC/DC booster converter

Technical field

The present invention relates to a kind of combined DC/DC booster converter, especially a kind of combination basic booster converter (hereinafter to be referred as the Boost circuit) and electric capacity are isolated the booster converter of buck-boost converter (hereinafter to be referred as the Cuk circuit), belong to the DC converting technical field.

Technical background

Booster converter Boost circuit is the most basic and the most frequently used booster circuit, when the gain of boosting of circuit near 0.9 time of its duty ratio increases sharply, makes the job stability of circuit and energy conversion efficiency be difficult to guarantee, should avoid in the design.The Cuk circuit has the buck function, and output ripple is little, but as booster circuit, littler than the gain of Boost circuit, duty ratio is difficult to guarantee near the job stability and the energy conversion efficiency of 0.9 o'clock circuit equally.U.S. Pat 6,522,192 disclose a kind of voltage multiplying circuit, have overcome the shortcoming of aforementioned Boost circuit, but because it has used three electronic switches, make the circuit complexity, the cost height, and the rush of current of transient state is arranged.

The air-conditioning power supply of railway locomotive generally needs earlier DC110V to be transformed into DC540V, and another mistake becomes 3 phase AC380V, and requires the input voltage range (DC40V-DC150V) and the high workload stability of broad.When input voltage was 40V, step-up ratio M was 13.25.Compare analysis for ease of stability, the definition coefficient of stability to circuit

W = \frac{dD}{dM},

D is a duty ratio in the formula, and M is the gain of boosting.

1, as if the Boost circuit of using as shown in Figure 1, have:

M = \frac{1}{1 - D},

When M was 13.25, D was 0.926, and coefficient of stability W is 0.0055.

2, as if the Cuk circuit of using as shown in Figure 2, have:

M = \frac{D}{1 - D},

When M was 13.25, D was 0.931, and coefficient of stability W is 0.0048.

More than the analysis showed that duty ratio near 0.9 o'clock, it is very poor that the stability of two kinds of circuit all becomes, and power device operating voltage higher, Cuk circuit especially.The general coefficient of stability is the bigger the better.

Summary of the invention

The object of the invention is to propose a kind of combined DC/DC booster converter, the DC-to-DC circuit topology is provided, and is 10 o'clock common Boost circuit of replacement waiting step-up ratio, reduces duty ratio, make the work of circuit more stable, reduce the operating voltage of power tube and rectifier diode simultaneously.

The combined DC/DC booster converter that the present invention proposes comprises:

Be used for that voltage to the main driving point V1 of converter circuit carries out that forward boosts and energy storage, with the basic boost converter circuit of the voltage of the positive limit Vb that produces the converter out-put supply, form by switching diode (21) and storage capacitor (22), wherein the anode of switching diode (21) is connected with the main driving point V1 of circuit, the negative electrode of switching diode (21) and the positive limit Vb that becomes out-put supply after storage capacitor (22) is connected;

Be used for voltage to the main driving point V1 of converter circuit and carry out that negative sense boosts and energy storage, electric capacity isolation buck-boost converter circuit with the voltage of the negative pole point Vk that produces the converter out-put supply, by isolation capacitance (33), energy storage inductor (35), switching diode (31) and filter capacitor (32) are formed, wherein an end of isolation capacitance (33) is connected with the main driving point V1 of circuit, become the negative pole point Vk of out-put supply behind the other end of isolation capacitance (33) and energy storage inductor 35 polyphones, the negative electrode of switching diode (31) is connected with the negative pole of converter input power supply (11), the anode of switching diode (31) is connected with the tie point of isolation capacitance (33) with energy storage inductor (35), and filter capacitor (32) is connected across between the negative pole point Vk of the negative pole of converter input power supply (11) and converter out-put supply;

Above-mentioned basic boost converter circuit and electric capacity are isolated the shared main boost inductance (12) and the switching tube (13) of buck-boost converter circuit, wherein the positive pole of the input power supply (11) of converter is connected with an end of main boost inductance (12), the other end of main boost inductance (12) is connected with the drain electrode of switching tube (13), the source electrode of switching tube (13) is connected with the negative pole of converter input power supply (11), and main boost inductance (12) is the main driving point V1 of converter circuit with the junction of the drain electrode of switching tube (13).The combined DC/DC booster converter that the present invention proposes, circuit is simple, the main booster of shared main boost inductance 12 and boosted switch pipe 13 built-up circuits, under its instigating, the Boost unit provides voltage gain 1/ (1-D), the Cuk unit provides voltage gain D/ (1-D), and total voltage gain is (1+D)/(1-D).

The Cuk circuit is a negative output, and itself and the simple directly combination of Boost circuit have promptly been constituted the composite type booster converter.The booster converter that the present invention proposes, the gain of boosting

M = \frac{1 + D}{1 - D},

Therefore when the M and the existing Boost circuit of converter of the present invention and the Cuk circuit is all 13.25, when duty ratio D is all 0.862, the coefficient of stability W of this converter is 0.0095, therefore the coefficient of stability doubles than Boost circuit and Cuk circuit, and the voltage stress of power tube reduces greatly simultaneously.

Description of drawings

Fig. 1 is existing conventional Boost DC-DC voltage boosting circuit diagram.

Fig. 2 is existing conventional Cuk DC-to-DC circuit diagram.

Fig. 3 is the circuit diagram of the combined DC/DC booster converter that proposes of the present invention.

Fig. 4 and Fig. 5 are respectively the voltage and current oscillograms of combined DC/DC booster converter of the present invention.

Embodiment

The combined DC/DC booster converter that the present invention proposes, its circuit comprises as shown in Figure 3:

(1) be used to Boost circuit and Cuk circuit that shared main boost inductance 12 and switching tube 13 are provided, wherein the positive pole of the input power supply 11 of converter is connected with an end of main boost inductance 12, the other end of main boost inductance 12 is connected with the drain electrode of switching tube 13, the source electrode of switching tube 13 is connected with the negative pole of converter input power supply 11, and main boost inductance 12 is the main driving point V1 of converter circuit with the junction of the drain electrode of switching tube 13;

(2) be used for voltage to the main driving point V1 of converter circuit and carry out that forward boosts and energy storage, Boost circuit with the voltage of the positive limit Vb that produces the converter out-put supply, form by switching diode 21 and storage capacitor 22, wherein the anode of switching diode 21 is connected with the main driving point V1 of circuit, the negative electrode of switching diode 21 and the positive limit Vb that becomes out-put supply after storage capacitor 22 is connected;

(3) be used for voltage to the main driving point V1 of converter circuit and carry out that negative sense boosts and energy storage, Cuk circuit with the voltage of the negative pole point Vk that produces the converter out-put supply, by isolation capacitance 33, energy storage inductor 35, switching diode 31 and filter capacitor 32 are formed, wherein an end of isolation capacitance 33 is connected with the main driving point V1 of circuit, become the negative pole point Vk of out-put supply behind the other end of isolation capacitance 33 and energy storage inductor 35 polyphones, the negative electrode of switching diode 31 is connected with the negative pole of converter input power supply 11, the anode of switching diode 31 is connected with the tie point of isolation capacitance 33 with energy storage inductor 35, and filter capacitor 32 is connected across between the negative pole point Vk of the negative pole of converter input power supply 11 and converter out-put supply.

Cuk and Boost DC-DC voltage boosting circuit voltage waveform are shown in figure (4), and current waveform is shown in figure (5).During switching tube 13 conductings (Ton), main driving point V1 voltage approximates 0, and the V2 point approximates-Vc/ (1-D), input power supply 11 is by main boost inductance 12, switching tube 13 constitutes the loop, electric current rising energy storage in the main boost inductance 12, the electric current in the energy storage inductor 35 also flow into boosted switch pipes 13 by isolation capacitance 33, and the energy storage that also raises of the electric current in the energy storage inductor 35.At this moment, switching diode 21 is reverse, and storage capacitor 22 is by load resistance 14 discharges.Switching tube 13 shutdown moment master driving point V1 voltages rise to Vc/ (1-D) by zero, and the V2 point approximates 0.During switching tube 13 turn-offs (Toff), input power supply 11 is by main boost inductance 12, switching diode 21, load resistance 14, energy storage inductor 35, switching diode 31 constitutes the loop, import power supply 11 simultaneously by main boost inductance 12, isolation capacitance 33, switching diode 31 constitutes the loop, and energy storage inductor 35 constitutes the loop by load resistance 14, storage capacitor 22.Electric current in this moment main boost inductance 12 and the energy storage inductor 35 all reduces and releases energy, and isolation capacitance 33 and storage capacitor 22 equal storage power.

Certainly, the present invention's composite type DC-DC booster circuit is not limited to illustrated embodiment, as adopt other form mains switch 13, increase the combination progression of Cuk and Boost etc., these variations all drop within protection scope of the present invention.

Claims

1, a kind of combined DC/DC booster converter is characterized in that this converter comprises:

Be used for that voltage to the main driving point (V1) of converter circuit carries out that forward boosts and energy storage, with the basic boost converter circuit of the voltage of the positive limit (Vb) that produces the converter out-put supply, form by switching diode (21) and storage capacitor (22), wherein the anode of switching diode (21) is connected with the main driving point (V1) of circuit, the negative electrode of switching diode (21) and the positive limit (Vb) that becomes out-put supply after storage capacitor (22) is connected;

Be used for voltage to the main driving point (V1) of converter circuit and carry out that negative sense boosts and energy storage, electric capacity with the voltage of the negative pole point (Vk) that produces the converter out-put supply is isolated the buck-boost converter circuit, by isolation capacitance (33), energy storage inductor (35), switching diode (31) and filter capacitor (32) are formed, wherein an end of isolation capacitance (33) is connected with the main driving point (V1) of circuit, become the negative pole point (Vk) of out-put supply behind the other end of isolation capacitance (33) and energy storage inductor 35 polyphones, the negative electrode of switching diode (31) is connected with the negative pole of converter input power supply (11), the anode of switching diode (31) is connected with the tie point of isolation capacitance (33) with energy storage inductor (35), and filter capacitor (32) is connected across between the negative pole point (Vk) of the negative pole of converter input power supply (11) and converter out-put supply;

Above-mentioned basic boost converter circuit and electric capacity are isolated the shared main boost inductance (12) and the switching tube (13) of buck-boost converter circuit, wherein the positive pole of the input power supply (11) of converter is connected with an end of main boost inductance (12), the other end of main boost inductance (12) is connected with the drain electrode of switching tube (13), the source electrode of switching tube (13) is connected with the negative pole of converter input power supply (11), and main boost inductance (12) is the main driving point (V1) of converter circuit with the junction of the drain electrode of switching tube (13).