CN109309448A - A Wide Input Wide Output Cuk DC-DC Converter - Google Patents

Abstract

The present invention proposes a kind of wide output Cuk DC-DC converter of wide input.Mentioned converter enhances beneficial expanding element with several by basic Cuk converter and forms.It enhances beneficial expanding element to be made of an inductance, two capacitors and a diode, the adjusting to converter input and output gain and switching device voltage stress can be realized by the number that adjusting enhances beneficial expanding element.Mentioned converter has the advantages such as control and simple, wide, the switching device voltage stress of input and output voltage adjustable range of driving circuit, is more suited to input or the biggish application of output voltage variation range.

Description

A kind of wide output Cuk DC-DC converter of wide input

Technical field

The present invention relates to a kind of wide input and output buck DC/DC converter, specifically a kind of wide wide output Cuk of input DC-DC converter.

Background technique

The biggish application of voltage change is being output and input, input voltage could possibly be higher than output voltage, can also Output voltage can be lower than, applicable common non-isolation type step-up/step-down dc-dc converter has Buck-Boost, Cuk, Sepic at this time And Zeta circuit.Theoretically by adjusting duty ratio D, the input and output gain of these converters can be zero to infinity Between change, but influenced by component and circuit parasitic parameter, the boost capability of these converters has been more limited.Mesh The preceding scheme for improving DC-DC converter input and output gain is based on Boost circuit more and constructs, thus these circuits are typically only capable to It realizes boosting, can not achieve decompression, be difficult to be applicable in outputting and inputting the biggish application of voltage change.Therefore it studies and is High gain boost can be achieved, while can also realize that the novel wide input and output buck DC/DC converter of decompression has important meaning Justice.

Summary of the invention

It cannot realize that high gain boost is asked with what is be depressured simultaneously to solve existing non-isolation type high-gain DC-DC converter Topic, the present invention is based on basic Cuk circuits to propose a kind of wide input and output buck DC/DC converter.

The technical scheme adopted by the invention is as follows:

A kind of wide output Cuk DC-DC converter of wide input, the converter include a direct current input source, a load R_L, a basic Cuk converter, n expanding element.Wherein:

Basic Cuk converter includes two inductance L₁、L₂, two capacitor C₁、C₂, a power switch S₁, a diode D₁.Its type of attachment is as follows: inductance L₁Left end connect the anode of input power, right end connects power switch S₁Drain electrode and electricity Hold C₁Left end, capacitor C₁Right end and inductance L₂Left end and diode D₁Anode be connected, inductance L₂Right end and capacitor C₂Upper end be connected, power switch S₁Source electrode, diode D₁Cathode and capacitor C₂Lower end and the cathode phase of input power Even.

The component of n expanding element and internal type of attachment are all the same, illustrate by taking i-th of expanding element as an example, contain Have: an inductance L_i1, a diode D_i1, two capacitor C_i1、C_i2.Wherein capacitor C_i1Right end and inductance L_i1Left end and Diode D_i1Anode be connected, inductance L_i1Right end and capacitor C_i2Upper end be connected.

Type of attachment between each expanding element is following (1 < i≤n): capacitor C in (i-1)-th expanding element_(i-1)1The right side End, inductance L_(i-1)1Left end and diode D_(i-1)1The connected intersection point and i-th of expanding element of anode in capacitor C_i1A left side End is connected, inductance L in (i-1)-th expanding element_(i-1)1Right end and capacitor C_(i-1)2The connected intersection point in upper end extended with i-th Diode D in unit_i1Cathode be connected, capacitor C in (i-1)-th expanding element_(i-1)2Lower end and electricity in i-th expanding element Hold C_i2Lower end and input power cathode be connected.

Connection relationship between 1st expanding element and basic Cuk converter is as follows: capacitor C in basic Cuk converter₁ Right end and inductance L₂Left end and diode D₁The connected intersection point and the 1st expanding element of anode in capacitor C₁₁Left end It is connected, inductance L in basic Cuk converter₂Right end and capacitor C₂The connected intersection point and the 1st expanding element in upper end in two poles Pipe D₁₁Cathode be connected.

Load R_LBoth ends and capacitor C in n-th expanding element_n2Both ends be connected.

Power switch S₁Grid connect its controller, duty ratio can change between 0 to 1.

A kind of wide input and output buck DC/DC converter of the present invention, technical effect are as follows:

1, buck, and input and output high gain can be achieved at the same time, switching device voltage stress is low.(inductance specific as follows L₁Electric current when being continuously turned on):

Input and output gain are as follows:

Switch tube voltage stress are as follows:

Wherein D is duty ratio, u_inFor input voltage, u_oFor output voltage, u_sFor power switching voltage stress, n is extension Element number.

2, only contain 1 power switch, control strategy and driving circuit are simple.

Detailed description of the invention

Fig. 1 is circuit diagram of the present invention.

Fig. 2 be expanding element number of the present invention be 1 when circuit topology figure.

Fig. 3 is traditional Cuk converter circuit schematic diagram

Fig. 4 be expanding element number of the present invention be 1 when input and output gain and tradition Cuk converter input and output gain Comparison diagram.

Specific embodiment

The present invention is described in further detail below in conjunction with the accompanying drawings.

It is illustrated in figure 2 circuit topology figure when expanding element number of the present invention is 1:

A kind of wide output Cuk DC-DC converter of wide input, the converter include a direct current input source, a load R_L, a basic Cuk converter, an expanding element.Wherein:

Basic Cuk converter includes two inductance L₁、L₂, two capacitor C₁、C₂, a power switch S₁, a diode D₁.Its type of attachment is as follows: inductance L₁Left end connect the anode of input power, right end connects power switch S₁Drain electrode and electricity Hold C₁Left end, capacitor C₁Right end and inductance L₂Left end and diode D₁Anode be connected, inductance L₂Right end and capacitor C₂Upper end be connected, power switch S₁Source electrode, diode D₁Cathode and capacitor C₂Lower end and the cathode phase of input power Even.

Expanding element contains: an inductance L₁₁, a diode D₁₁, two capacitor C₁₁、C₁₂.Wherein capacitor C₁₁Right end With inductance L₁₁Left end and diode D₁₁Anode be connected, inductance L₁₁Right end and capacitor C₁₂Upper end be connected, capacitor C₁₂ Lower end be connected with the cathode of input power.

Connection relationship between expanding element and basic Cuk converter is as follows: capacitor C in basic Cuk converter₁Right end With inductance L₂Left end and diode D₁The connected intersection point and expanding element of anode in capacitor C₁₁Left end be connected, substantially Inductance L in Cuk converter₂Right end and capacitor C₂The connected intersection point and expanding element in upper end in diode D₁₁Cathode phase Even.

Load R_LBoth ends and expanding element in capacitor C₁₂Both ends be connected.

Power switch S₁Grid connect its controller, duty ratio can change between 0 to 1.

In inductance L₁Electric current when being continuously turned on, according to the difference of power switch state, circuit can be divided into 2 kinds of work State:

(1) power switch S₁Conducting, diode D₁、D₁₁It is turned off, at this time inductance L₁、L₂、L₁₁, capacitor C₂、C₁₂Charging, electricity Hold C₁、C₁₁Electric discharge；Inductance L₁、L₂、L₁₁End voltage is shown below:

(2) power switch S₁Shutdown, diode D₁、D₁₁It is both turned on, at this time inductance L₁、L₂、L₁₁, capacitor C₂、C₁₂Electric discharge, electricity Hold C₁、C₁₁Charging；Inductance L₁、L₂、L₁₁End voltage is shown below:

Above-mentioned embodiment of the invention is only example to illustrate the invention, and is not to reality of the invention Apply the restriction of mode.For those of ordinary skill in the art, other can also be made on the basis of the above description Various forms of variations and variation.Here all embodiments can not be exhaustive.It is all to belong to technical side of the invention Case, changes and variations that derived from are still in the scope of protection of the present invention.

Claims (2)

1. a kind of wide output Cuk DC-DC converter of wide input, it is characterised in that: the converter includes a direct current input source, One load R_L, a basic Cuk converter, n expanding element；Wherein:

Basic Cuk converter includes two inductance L₁、L₂, two capacitor C₁、C₂, a power switch S₁, a diode D₁；Its Type of attachment is as follows: inductance L₁Left end connect the anode of input power, right end connects power switch S₁Drain electrode and capacitor C₁'s Left end, capacitor C₁Right end and inductance L₂Left end and diode D₁Anode be connected, inductance L₂Right end and capacitor C₂It is upper End is connected, power switch S₁Source electrode, diode D₁Cathode and capacitor C₂Lower end be connected with the cathode of input power；

The component of n expanding element and internal type of attachment are all the same, illustrate by taking i-th of expanding element as an example, contain: one A inductance L_i1, a diode D_i1, two capacitor C_i1、C_i2；Wherein capacitor C_i1Right end and inductance L_i1Left end and two poles Pipe D_i1Anode be connected, inductance L_i1Right end and capacitor C_i2Upper end be connected；

Type of attachment between each expanding element is as follows, capacitor C in 1 < i≤n: the (i-1)-th expanding element_(i-1)1Right end, electricity Feel L_(i-1)1Left end and diode D_(i-1)1The connected intersection point and i-th of expanding element of anode in capacitor C_i1Left end phase Even, inductance L in (i-1)-th expanding element_(i-1)1Right end and capacitor C_(i-1)2The connected intersection point and i-th of expanding element in upper end Middle diode D_i1Cathode be connected, capacitor C in (i-1)-th expanding element_(i-1)2Lower end and capacitor C in i-th expanding element_i2 Lower end and input power cathode be connected；

Connection relationship between 1st expanding element and basic Cuk converter is as follows: capacitor C in basic Cuk converter₁Right end With inductance L₂Left end and diode D₁The connected intersection point and the 1st expanding element of anode in capacitor C₁₁Left end be connected, Inductance L in basic Cuk converter₂Right end and capacitor C₂The connected intersection point and the 1st expanding element in upper end in diode D₁₁ Cathode be connected；

Load R_LBoth ends and capacitor C in n-th expanding element_n2Both ends be connected.

2. a kind of wide output Cuk DC-DC converter of wide input according to claim 1, it is characterised in that: power switch S₁'s Grid connects its controller, and duty ratio can change between 0 to 1.