CN101453162B - Topology of T-type boost converter - Google Patents

Abstract

Topology of T-type boost converter, switch S_k1Switch S_(k-1)1… … switch S₂₁Switch S₁₁Switch S_D12Switch S_D22… … switch S_D(k-1)2Sequentially connected in series to form a transverse shaft of the T-type converter; capacitor C₁Capacitor C₂… … capacitor C_kSequentially connected in series to form a longitudinal shaft of the T-shaped converter; switch S_k1One end and a switch S_(k-1)1One end is connected with a switch S_k1The other end is connected with the high potential end of the power supply through an inductor L, and the low potential end of the power supply is connected with a switch S_D(k-1)2Connecting; switch S_k1One end connected with the inductor L and the capacitor C_kBetween the positive poles there is a rectifying branch flowing unidirectionally from the transverse axis to the longitudinal axis, which is routed by a switch S_Dk1Composition is carried out; switch S_D(k-1)2Cathode and capacitor C_kAnd a capacitor C_(k-1)A unidirectional controllable switch branch which flows from the longitudinal axis to the transverse axis is arranged between the nodes; wherein the switch S_i1And switch S_(i+1)1Node between and capacitance C_iAnd a capacitor C_(i+1)A rectifying branch i which flows from the transverse axis to the longitudinal axis in a single direction is 1, 2.. k-1 between the nodes; in the capacitor C_iAnd a capacitor C_(i+1)Node of and switch S_Di2And switch S_D(i+1)2A unidirectional controllable switch branch which flows from a longitudinal axis to a transverse axis is arranged between the nodes, and i is 1, 2. Capacitor C_kPositive electrode and capacitor C₁Negative indirect load resistance R_LAnd k is a positive integer greater than 1.

Description

Topology of T-type boost converter

technical field

The invention relates to a circuit topological structure of a step-up converter, in particular to a topological structure of a DC-DC type step-up converter using a single inductor.

Background technique

In the traditional DC-DC step-up circuit, when the step-up ratio is relatively high, a converter with a transformer structure or a multi-stage step-up structure is often used. Due to the high boost multiple, the control accuracy is difficult to be guaranteed, and the series structure of the system leads to low reliability and stability of the system.

Contents of the invention

The technical problem to be solved by the present invention is to solve the control accuracy when the boost multiple is high, and propose a topology structure that adopts multiple output capacitors in series and performs boost control on each output cascaded capacitor to achieve high performance boost conversion.

In order to achieve the above object, technical scheme of the present invention is as follows:

A T-type boost converter topology, through switch S _k1 , switch S _(k-1)1 ... switch S ₂₁ , switch S ₁₁ , switch S _D12 , switch S _D22 ... switch S _{D(k- 1) 2} , a total of 2k-1 switching devices are sequentially connected in series to form the horizontal axis of the T-type converter; through capacitors C ₁ , capacitors C ₂ ... capacitor C _k , a total of k capacitors are sequentially connected in series to form the vertical axis of the T-type converter; One end of the switch S _k1 is connected to one end of the switch S _(k-1)1 , the other end of the switch S _k1 is connected to the high potential end of the DC input power supply through the inductor L, and the low potential end of the DC input power supply is connected to the switch S _{D(k -1) 2} connected; there is a one-way rectification branch flowing from the horizontal axis to the vertical axis between the end of the switch S _k1 connected to the inductance L and the positive pole of the capacitor C _k , and the rectification branch is composed of the switch S _Dk1 ; the switch S _D There is a one-way controllable switch branch flowing from the vertical axis to the horizontal axis between the end of (k-1 ₎₂ connected to the low potential end of the DC input power supply and the node between the capacitor C _k and the capacitor C _(k-1) . The one-way controllable switch branch is composed of a switch S _k2 ; there is a unidirectional lateral flow between the node between the switch S _i1 and the switch S _(i+1)1 and the node between the capacitor C _i and the capacitor C _(i+1). The rectification branch of axial flow to the vertical axis, the rectification branch is composed of switch S _Di1 , i=1, 2...k-1; at the node of capacitor C _i and capacitor C _(i+1) and switch S _Di2 and There is a one-way controllable switch branch flowing from the vertical axis to the horizontal axis between the nodes between the switches S _D(i+1)2 , and the one-way controllable switch branch is composed of the switch S _(i+1)2 , i=1, 2...k-2; the positive pole of the capacitor C _k and the negative pole of the capacitor C ₁ are connected to the load resistance _RL ; by expanding the horizontal and vertical axes of the T-shaped structure and the unidirectional rectification branch, the unidirectional can The control switch branch can expand the converter, and k is a positive integer greater than 1.

Beneficial effects of the present invention:

Compared with the traditional DC-DC boost converter, the T-type boost converter disclosed in the present invention adopts a single-inductance structure to independently charge the capacitors on each series output side. , has high control precision; at the same time, it also overcomes the problems of insufficient stability and reliability of the multi-stage series system.

Description of drawings

FIG. 1 is a topological structure diagram of a T-type boost converter proposed by the present invention.

Figure 2(a) is a MOSFET equivalent example diagram of a controllable switch.

Figure 2(b) is an equivalent example diagram of an IGBT with a controllable switch.

Detailed ways

The present invention will be further described in conjunction with accompanying drawing:

Figure 1 is a topology diagram of a T-type boost converter. Switches S ₁₁ , S ₂₁ ... S _k1 , S _D12 , S _D22 ... S _D(k-1)2 (k is a positive integer greater than 1, the same below) a total of 2k-1 switching devices are connected in series to form a T-type conversion The horizontal axis of the T-type converter is formed by capacitors C ₁ , C ₂ ... C _k , a total of k capacitors are connected in series to form the vertical axis of the T-type converter; the switch S _k1 is connected to the high potential end of the DC input power supply through the inductor L, and the DC input power supply The low potential end is connected to the switch S _D(k-1)2 ; wherein the node between the switch S _i1 and S _(i+1)1 (i=1, 2...k-1) and the capacitance C _i and C ₍ There is a one-way rectification branch from the horizontal axis to the vertical axis between the nodes of _i+1) , between the nodes of capacitors C _i and C _(i+1) and switches S _Di2 and S _D(i+1)2 There is a one-way controllable switch branch flowing from the vertical axis to the horizontal axis between the nodes. The converter can be expanded by extending the horizontal and vertical axes of the T-shaped structure, the unidirectional rectification branch, and the unidirectional controllable switch branch. The load _RL represents the load of the system, which can have various forms and properties.

The switches S _k1 , S _Dk1 , S _D(k-1)2 , the capacitor C _k , and the switch S _k2 constitute the extended unit group of the T-type converter. When this component group is added and the circuit is expanded according to the above connection method, The number of stages of the converter can be increased.

The capacitors C ₁ , C _{2 .} The discharge state is the same as that of the traditional boost converter, and will not be described here. The following is a brief description of the time-sharing charging of each power supply.

The charging process of each capacitor can be divided into the stage of inductance energy storage and the stage of energy transfer from inductance to capacitor. Taking the capacitor C _n (n=1, 2...k) shown in Figure 1 as an example, its energy storage and During the energy transfer process, the switch S _n2 is set to be in the on state, the switch S _j2 (j≠n) is in the off state, and the horizontal _axis controllable switches S ₁₁ , S ₂₁ ... S _{(n-1 )1} and S _(n+1)1 are placed in the conduction state, and work is performed by switching the switching state of S _n1 . The detailed process is as follows.

Inductive energy storage stage of capacitor C _n (n=1, 2...k): when switch S _n1 is turned on, switches S _D12 , S _D22 ... S _D(k-1)2 are forward biased Enter the conduction state, at this time, V, inductor L, switches S ₁₁ , S ₂₁ ... S _k1 , S _D12 , S _D22 ... S _D(k-1)2 form a loop, and the DC input power supply stores energy on the inductor , the current in the inductor keeps increasing.

The energy transfer stage of the capacitor C _n (n=1, 2...k) to the capacitor: when the switch S _n1 is turned off, the power supply V, the inductor L, the switch S _k1 ... S _(n+2)1 , S _{(n+ 1)1} , capacitor C _n , switches S _n2 , S _Dn2 ... _SD(k-1)2 constitute a loop, and at this time the energy of the DC input power supply and the inductance is transferred to the capacitor C _n .

For the other capacitances on the vertical axis, there are two special cases of the above work process analysis that need to be ruled out:

(1) When the capacitor C ₁ is charging, because there is no switch S ₁₂ , the circuit at this time is: power supply V, inductor L, switches S ₂₁ , S ₃₁ ... S _k1 , capacitor C ₁ , switches S _D12 , S _D22 ... S _D(k-1)2 ;

(2) When the capacitor C _k is being charged, because there is no switch S _Dk2 , the circuit at this time is: power supply V, inductor L, capacitor C _k , and switch S _k2 .

Figure 2(a) is a MOSFET equivalent example diagram of a controllable switch. Figure 2(b) is an equivalent example diagram of an IGBT with a controllable switch. The switches in the topology can choose a variety of controllable switches or switch topologies, and only two examples are given here.

Claims (3)

1. A topology structure of a T-type boost converter, characterized in that: through switch S _k1 , switch S _(k-1)1 ... switch S ₂₁ , switch S ₁₁ , switch S _D12 , switch S _D22 ... Switch S _D(k-1)2 , a total of 2k-1 switching devices are serially connected in series to form the horizontal axis of the T-type converter; through capacitor C ₁ , capacitor C ₂ ... capacitor C _k , a total of k capacitors are sequentially connected in series to form a T-type converter The vertical axis of the converter; one end of the switch S _k1 is connected to one end of the switch S _(k-1)1 , the other end of the switch S _k1 is connected to the high potential end of the DC input power supply through the inductor L, and the low potential end of the DC input power supply It is connected with the switch S _D(k-1)2 ; between the end of the switch S _k1 connected to the inductance L and the positive pole of the capacitor C _k , there is a one-way rectification branch flowing from the horizontal axis to the vertical axis, and the rectification branch is provided by the switch S Composed of _Dk1 ; there is a one-way flow from the vertical axis to the horizontal axis between the end of the switch S _D(k-1)2 connected to the low potential end of the DC input power supply and the node of the capacitor C _k and the capacitor C _(k-1). Controlled switch branch, the one-way controllable switch branch is composed of switch S _k2 ; wherein the node between switch S _i1 and switch S _(i+1)1 and the node between capacitor C _i and capacitor C _(i+1) There is a one-way rectification branch flowing from the horizontal axis to the vertical axis, the rectification branch is composed of switch S _Di1 , i=1, 2...k-1; at the node of capacitor C _i and capacitor C _i+1 and There is a one-way controllable switch branch flowing from the vertical axis to the horizontal axis between the node between the switch S _Di2 and the switch S _D(i+1)2 , and the one-way controllable switch branch is routed by the switch S _{(i+1 )2} , i=1, 2...k-2; the positive pole of the capacitor C _k and the negative pole of the capacitor C ₁ are connected to the load resistance _RL ; by expanding the horizontal and vertical axes of the T-shaped structure and the unidirectional rectification branch . The one-way controllable switch branch can expand the converter, and k is a positive integer greater than 1. 2. The topology of the T-type boost converter according to claim 1, characterized in that: the switch S _k1 , the switch S _Dk1 , the switch S _D(k-1)2 , the capacitor C _k , and the switch S _k2 constitute T The expansion unit group of the type converter, when adding the expansion unit group and expanding the circuit according to the above-mentioned connection method, the number of stages of the converter will be increased. 3. The topology structure of the T-type boost converter according to claim 1, characterized in that: switch S ₁₁ , switch S ₂₁ ... switch S _k1 , switch S ₂₂ ... switch S _k2 selects controllable power electronic switches IGBT or MOSFET.

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