CN103441668A - High-gain boost DC-DC converter allowing pseudo continuous work - Google Patents

Abstract

The invention discloses a high-gain boost DC-DC converter allowing pseudo continuous work. The high-gain boost DC-DC converter comprises a first switch pipe, a second switch pipe, a third switch pipe, a first diode, a second diode, a third diode, a first inductor, a second inductor, a first capacitor, a second capacitor and a load; the first switch pipe, the third switch pipe, the first diode, the second diode, the first inductor and the first capacitor constitute a first-level Boost circuit; the first switch pipe, the second switch pipe, the third diode, the second inductor, the first capacitor and the second capacitor constitute a second-level Boost circuit. The high-gain boost DC-DC converter is high in response speed, small in current ripple, and suitable for being applied on large-power occasions.

Description

A High-Gain Step-Up DC-DC Converter with Pseudo-continuous Operation

technical field

The invention relates to the technical field of power electronic converters, in particular to a high-gain step-up DC-DC converter with pseudo-continuous operation.

Background technique

With the development of life and technology, the requirements for power electronic converters are becoming increasingly stringent. The traditional single-phase single-stage Boost converter can no longer meet the needs of many industries and electronics industries. Booster circuits with higher gain, higher power, and faster dynamic response have attracted more and more attention. The traditional method is to increase the gain of the converter through the cascading of multiple Boost links and the interleaved parallel connection of multiple Boost links, to improve the dynamic response speed of the converter by making the converter work in DCM mode, and to make the converter work continuously with the inductor current. mode boosts power. These methods are costly, complex circuits, and must be traded off between fast dynamic response and high power.

Contents of the invention

The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art, and provide a high-gain step-up DC-DC converter with pseudo-continuous operation. The invention is suitable for occasions requiring high gain and fast dynamic response power electronic converters.

The present invention adopts following technical scheme:

A high-gain step-up DC-DC converter with pseudo-continuous operation, comprising a first switching tube S1, a second switching tube S2, a third switching tube S3, a first diode D1, a second diode D2, The third diode D3, the first inductor L1, the second inductor L2, the first capacitor C1, the second capacitor C2 and the load R;

One end of the first inductance L1 is respectively connected to the anode of the input power supply and the source of the third switching tube S3, and the other end of the first inductance L1 is respectively connected to the anode of the first diode D1 and the second diode The anode of D2 is connected to the drain of the third switching tube S3;

The cathode of the first diode D1 is respectively connected to one end of the second inductor L2, one end of the first capacitor C1, and the source of the second switching tube S2;

The cathode of the second diode D2 is respectively connected to the other end of the second inductor L2, the anode of the third diode D3, the drain of the first switch S1, and the drain of the second switch S2;

The cathode of the third diode D3 is respectively connected to one end of the second capacitor C2 and one end of the load R; the other end of the first capacitor C1 is respectively connected to the negative pole of the input power supply, the source pole of the first switching tube S1, The other end of the second capacitor C2 is connected to the other end of the load R.

The first switch tube S1, the third switch tube S3, the first diode D1, the second diode D2, the first inductor L1, and the first capacitor C1 form a first-stage Boost circuit; the first switch tube S1 , the second switch tube S2 , the third diode D3 , the second inductor L2 , the first capacitor C1 and the second capacitor C2 form a second stage Boost circuit.

When the current flowing through the second inductor L2 drops to the reference current, the second diode S2 and the third switch tube S3 are turned on at the same time, so that the second inductor L2 and the first inductor work in the natural freewheeling mode until the first switch tube S1 is opened.

Beneficial effects of the present invention:

The present invention is a step-up converter with higher gain and faster dynamic response speed and is suitable for high-power occasions, which solves the problem of high cost and complex circuit of the traditional method, and the need to achieve a balance between fast dynamic response and high power A question of giving up one or the other.

Description of drawings

Fig. 1 is a circuit structure diagram of the present invention;

Figures 2(a)-2(c) are diagrams of the working process of the present invention in one switching cycle, where Figure 2(a) is the working state of the converter when the first switching tube S1 is closed and the second switching tube S2 is open ; Figure 2(b) is the working state of the converter when the first switch tube S1 is off and the second switch tube S2 is off; Figure 2(c) is when the first switch tube S1 is off and the second switch tube S2 is on The working state of the converter, the solid line circuit in the figure indicates the part of the converter where current flows, and the dotted line indicates the part of the converter where no current flows;

Fig. 3 is the main waveform diagram of the present invention in a switching period, wherein V _Gs1 , V _Gs2 , V _Gs3 respectively represent the pulse driving signals of the first switching tube S1, the second switching tube S2, and the third switching tube S3, i _L1 (indicated by a solid line) and i _L2 (indicated by a dotted line) represent the current flowing through the inductor, V _L1 and V _L2 represent voltages across the first inductor L1 and the second inductor L2 respectively.

Detailed ways

The present invention will be described in further detail below in conjunction with the embodiments and the accompanying drawings, but the embodiments of the present invention are not limited thereto.

Example

As shown in Figure 1, a high-gain step-up DC-DC converter with pseudo-continuous operation includes a first switching tube S1, a second switching tube S2, a third switching tube S3, a first diode D1, and a second switching tube S3. Two diodes D2, a third diode D3, a first inductor L1, a second inductor L2, a first capacitor C1, a second capacitor C2 and a load R;

One end of the first inductance L1 is respectively connected to the anode of the input power supply and the source of the third switching tube S3, and the other end of the first inductance L1 is respectively connected to the anode of the first diode D1 and the second diode The anode of D2 is connected to the drain of the third switching tube S3;

The cathode of the first diode D1 is respectively connected to one end of the second inductor L2, one end of the first capacitor C1, and the source of the second switching tube S2;

The cathode of the second diode D2 is respectively connected to the other end of the second inductor L2, the anode of the third diode D3, the drain of the first switch S1, and the drain of the second switch S2;

The cathode of the third diode D3 is respectively connected to one end of the second capacitor C2 and one end of the load R; the other end of the first capacitor C1 is respectively connected to the negative pole of the input power supply, the source pole of the first switching tube S1, The other end of the second capacitor C2 is connected to the other end of the load R.

The first switch tube S1, the third switch tube S3, the first diode D1, the second diode D2, the first inductor L1, and the first capacitor C1 form a first-stage Boost circuit; the first switch tube S1 , the second switch tube S2 , the third diode D3 , the second inductor L2 , the first capacitor C1 and the second capacitor C2 form a second stage Boost circuit.

When the current flowing through the second inductor L2 drops to the reference current, the second diode S2 and the third switch tube S3 are turned on at the same time, so that the second inductor L2 and the first inductor work in the natural freewheeling mode until the first switch tube S1 is opened.

In one switching cycle of the converter, both the second inductor L2 and the first inductor L1 work in the pseudo-continuous working mode of the inductor current, which not only reduces the current ripple but also increases the circuit gain, and at the same time the dynamic response speed of the circuit is significantly improved.

The working process of a high-gain step-up DC-DC converter with pseudo-continuous operation in one switching cycle of the present invention is as follows:

Working state 1: As shown in FIG. 2( a ), the first switch tube S1 is turned on, and the second switch tube S2 and the third switch tube S3 are turned off at the same time. At this time, the second diode D2 is turned on, and the first diode D1 and the third diode D3 are in an off state due to the reverse bias of the voltages at both ends of the first capacitor C1 and the second capacitor C2 respectively. The input power supply voltage charges the first inductor L1, the current flowing through the first inductor L1 begins to increase, and the first inductor L1 stores energy; at the same time, the first capacitor C1 charges the second inductor L2, and the current flowing through the second inductor L2 begins to increase , the second inductor L2 stores energy, and the second capacitor C2 supplies power to the load and maintains a stable output voltage.

Working state 2: As shown in Figure 2(b), the first switch tube S1 is turned off, the second switch tube S2 and the third switch tube S3 are turned off, at this time the first diode D1 and the third diode D3 is turned on, and the second diode D2 is in an off state under reverse bias. The input power and the first inductor L1 charge the first capacitor C1 at the same time, and charge the second capacitor C2 together with the second inductor L2 to supply power to the load. The current flowing through the first inductor L1 starts to drop, and the current flowing through the second inductor L2 also starts to drop.

Working state 3: As shown in Figure 2(c): the first switch tube S1 is turned off, the second switch tube S2 and the third switch tube S3 are turned on at the same time, at this time the first diode D1, the second diode Both D2 and the third diode D3 are in an off state. Both the first inductor L1 and the second inductor L2 work in an inertial state, the voltage at both ends of them is zero, and the current flowing through them remains unchanged.

Suppose the input voltage is V _d , the output voltage is the voltage across the second capacitor C2 is V _o , the voltage across the first capacitor C1 is V _c1 , and one switching cycle is Ts, where the duration of working state 1 is d1Ts (d1 is working The duration of state 1 accounts for the duty cycle of the entire switching cycle), the duration of working state 2 is d2Ts (d2 is the duty cycle of the duration of working state 2 accounting for the entire switching cycle), and the duration of working state 3 is d3Ts (d3 is the duty cycle of the working state The duration of state 3 accounts for the duty cycle of the entire switching cycle), and d1, d2, and d3 satisfy the following relationship: d1+d2+d3=1.

As shown in Figure 3, in working state 1, the voltage across the first inductor L1 is V _d , and the voltage across the second inductor L2 is V _c1 ; in working state 2, the voltage across the first inductor L1 is V _d -V _c1 , The voltage across the second inductor L2 is V _c1 −V _o ; in working state 3 , the voltage across the first inductor L1 is 0, and the voltage across the second inductor L2 is 0. According to the principle of inductance volt-second balance in a switching cycle, the following relationship can be obtained:

${<span\; class="notranslate">\; \&Integral;</span>}_{\mathrm{<span\; class="notranslate">\; 0</span>}}^{{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}\mathrm{<span\; class="notranslate">\; dt</span>}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; \&Integral;</span>}_{{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}^{{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; dt</span>}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; \&Integral;</span>}_{{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}^{{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}\mathrm{<span\; class="notranslate">\; 0</span>}\mathrm{<span\; class="notranslate">\; dt</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0</span>}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

${<span\; class="notranslate">\; \&Integral;</span>}_{\mathrm{<span\; class="notranslate">\; 0</span>}}^{{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; the\; <figure-callout\; id="1"\; label="s\; V\; c"\; filenames="HDA0000372174620000012.png,HDA0000372174620000021.png"\; state="\{\{state\}\}">s</figure-callout></span><figure-callout\; id="1"\; label="s\; V\; c"\; filenames="HDA0000372174620000012.png,HDA0000372174620000021.png"\; state="\{\{state\}\}">\; </figure-callout>}}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{}{\mathrm{<span\; class="notranslate">\; c</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}_{}\mathrm{<span\; class="notranslate">\; dt</span>}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; \&Integral;</span>}_{{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}^{{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; o</span>}}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; dt</span>}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; \&Integral;</span>}_{{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}^{{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}\mathrm{<span\; class="notranslate">\; 0</span>}\mathrm{<span\; class="notranslate">\; dt</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0</span>}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$

Simultaneous formula (1) and formula (2), can solve the converter gain M proposed by the present invention as:

$\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; o</span>}}}{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="d"\; filenames="HDA0000372174620000012.png,HDA0000372174620000021.png"\; state="\{\{state\}\}">d</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}$

The invention is a high-gain step-up DC-DC converter with pseudo-continuous operation of inductance current, which not only has fast dynamic response speed and small current ripple, but also is suitable for application in high-power occasions.

The above-mentioned embodiment is a preferred embodiment of the present invention, but the embodiment of the present invention is not limited by the embodiment, and any other changes, modifications, substitutions and combinations made without departing from the spirit and principle of the present invention , simplification, all should be equivalent replacement methods, and are all included in the protection scope of the present invention.

Claims (3)

1. the high gain boost type DC-DC converter of a pseudo-continuous work, it is characterized in that, comprise the first switching tube (S1), second switch pipe (S2), the 3rd switching tube (S3), the first diode (D1), the second diode (D2), the 3rd diode (D3), the first inductance (L1), the second inductance (L2), the first electric capacity (C1), the second electric capacity (C2) and load (R);

One end of described the first inductance (L1) is connected with the positive pole of input power, the source electrode of the 3rd switching tube (S3) respectively, and the other end of described the first inductance (L1) is connected with the anode of the first diode (D1), the anode of the second diode (D2), the drain electrode of the 3rd switching tube (S3) respectively;

The negative electrode of described the first diode (D1) is connected with an end of the second inductance (L2), an end of the first electric capacity (C1), the source electrode of second switch pipe (S2) respectively;

The negative electrode of described the second diode (D2) is connected with the other end of the second inductance (L2), the anode of the 3rd diode (D3), the drain electrode of the first switching tube (S1), the drain electrode of second switch pipe (S2) respectively;

The negative electrode of described the 3rd diode (D3) is connected with an end of the second electric capacity (C2), an end of load (R) respectively; The other end of described the first electric capacity (C1) is connected with the negative pole of input power, the source electrode of the first switching tube (S1), the other end of the second electric capacity (C2), the other end of load (R) respectively.

2. the high gain boost type DC-DC converter of a kind of pseudo-continuous work according to claim 1, it is characterized in that, described the first switching tube (S1), the 3rd switching tube (S3), the first diode (D1), the second diode (D2), the first inductance (L1) and the first electric capacity (C1) form first order Boost circuit; Described the first switching tube (S1), second switch pipe (S2), the 3rd diode (D3), the second inductance (L2), the first electric capacity (C1) and the second electric capacity (C2) form second level Boost circuit.

3. the high gain boost type DC-DC converter of a kind of pseudo-continuous work according to claim 1, it is characterized in that, when the electric current that flows through the second inductance (L2) drops to reference current, open the second diode (S2) and the 3rd switching tube (S3) simultaneously, make the second inductance (L2) and the first inductance (L1) work in nature afterflow pattern until the first switching tube (S1) is open-minded.

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