CN1352488A

CN1352488A - Two-way DC-DC converter

Info

Publication number: CN1352488A
Application number: CN 01132209
Authority: CN
Inventors: 陈刚; 徐德鸿; 汪槱生
Original assignee: Zhejiang University ZJU
Current assignee: Zhejiang University ZJU
Priority date: 2001-11-13
Filing date: 2001-11-13
Publication date: 2002-06-05
Anticipated expiration: 2021-11-13
Also published as: CN1127796C

Abstract

The invented two-way DC-DC converter is composed of two main switches, two asistant switches, transformer and clamped capacitance. A main switch, primary winding of transformer and DC power or active load are cascaded to form a loop. Another main switch, secondary winding of transformer and DC power or active load are cascaded to form a loop. Circuit of one assistant switch being cascaded to clamped capacitance is connected to two ends of primary winding of transformer or two ends of main switch that is cascaded to the primary winding. Circuit of another assistant switch being cascaded to clamped capacitance is connected to two ends of secondary winding of transformer or two ends of main switch that is cascaded to the secondary winding. The invented converter provides features of simple structure, low cost, easy to drive the switch tube and control the transformer and high working efficiency of the transformer.

Description

A kind of two-way DC-DC converter

Technical field

The present invention relates to two-way DC-DC converter.

Background technology

In recent years, in order to improve the efficient of two-way DC-DC converter, many soft switch techniques are used in succession.Some converters use harmonic technology, but often because exist higher voltage current stress and some converter to need factors such as frequency conversion work in the converter, have limited their application; Also have some converter using Zero voltage transition or zero current switch technology, yet weak point is that often the auxiliary switch device in the converter is not operated in soft on off state; Phase shift full-bridge type two-way DC-DC converter is owing to be suitable for large-power occasions, and at the small-power occasion complex structure that then seems, cost is too high.

Summary of the invention

The purpose of this invention is to provide a kind of simple in structure, cost is low, can guarantee that all device for power switching all realize soft switch work, loss is little, the two-way DC-DC converter that efficient is high.

For reaching above-mentioned purpose, the technical scheme that the present invention takes is: the phase shift of application symmetrical structure active clamp is controlled and is realized the transmitted in both directions of energy in converter.The two-way DC-DC converter of invention comprises two main switches, two auxiliary switches and transformer and clamp capacitor, the former limit winding of one of them main switch and transformer and DC power supply or active load are connected into the loop, the secondary winding of another main switch and transformer and DC power supply or active load are connected into the loop, auxiliary switch and the clamp capacitor circuit that is in series is connected across the two ends of the former limit of transformer winding, perhaps be connected across two ends with the main switch of former limit windings in series, another auxiliary switch and the clamp capacitor circuit that is in series is connected across the two ends of transformer secondary winding, perhaps is connected across the two ends with the main switch of secondary windings in series.

Two-way DC-DC converter structure of the present invention is very simple, cost is low, the driving of convertor controls and switching tube is easy, this converter can be realized soft switch work, in the low-voltage, high-current occasion, the synchronous rectifier working method has reduced the on-state loss of converter, and the converter operating efficiency is higher.

Description of drawings

Fig. 1 is one of circuit structure example of the present invention;

Fig. 2 is two of a circuit structure example of the present invention;

Fig. 3 is another physical circuit example of the present invention.

Embodiment

With reference to Fig. 1, the two-way DC-DC converter of invention comprises two main switch M1, M2, two auxiliary switch M3, M4, transformer Tx and clamp capacitor Cc1, Cc2, the former limit winding of one of them main switch M1 and transformer Tx and DC power supply or active load V1 are connected into the loop, the secondary winding of another main switch M2 and transformer Tx and DC power supply or active load V2 are connected into the loop, in this example, the series circuit of auxiliary switch M3 and clamp capacitor Cc1 is connected across the two ends of the former limit of transformer winding, and the series circuit of auxiliary switch M4 and clamp capacitor Cc2 is connected across the two ends of transformer secondary winding.Perhaps also can be as shown in Figure 2, the series circuit of auxiliary switch M3 and clamp capacitor Cc1 is connected across two ends with the main switch M1 of former limit windings in series, and the series circuit of another auxiliary switch M4 and clamp capacitor Cc2 is connected across the two ends with the main switch M2 of secondary windings in series.

Main switch and auxiliary switch can be power bipolar transistor or insulated door gated transistors or other controlled switching device.

Two-way DC-DC converter of the present invention, the leakage inductance of its transformer is the vitals of converter power transfer, in order to strengthen leakage inductance, also can be at the former limit winding of transformer and the secondary winding inductance of connecting respectively, see shown in Figure 3, the winding string has inductance L 1 on the former limit of transformer, and secondary winding string has inductance L 2.At this moment, the former limit winding of said transformer comprises the inductance L 1 of series connection with it, secondary even winding comprises the inductance L 2 of series connection with it, the series circuit of auxiliary switch M3 and clamp capacitor Cc1 is connected on the two ends of former limit winding and inductance L 1 series circuit, and the series circuit of auxiliary switch M4 and clamp capacitor Cc2 is connected across the two ends of secondary winding and inductance L 2 series circuits.

In the converter work, the switching frequency of four switching tubes is identical, and wherein the drive controlling of two main switches keeps identical duty ratio.The main switch in the same loop and the drive controlling of auxiliary switch are complimentary fashion, reach the size and Orientation of power transfer between two DC source of control or the active load by the phase relation of controlling two main switch drive signals.

During work, main switch of transformer the same side and auxiliary switch are in carrying out the switch handoff procedure, because the existence of transformer leakage inductance, a switching tube (as M1) closes and has no progeny therein, electric current in the leakage inductance will be to the parasitic capacitance discharge of another switching tube (M3) of homonymy, and (M3) will be by open-minded under the no-voltage situation afterwards.Like this, converter all can be realized soft switch work in two-way operation.After arbitrary switching tube was turned off, its both end voltage all was clamped on the fixed voltage, high voltage stress and vibration can not occur.

The present invention is applicable to the two-way DC-DC conversion occasion of small-power occasion, also can be used for unidirectional dc-dc conversion occasion.

Claims

1. two-way DC-DC converter, it is characterized in that it comprises two main switches [M1], [M2], two auxiliary switches [M3], [M4] and transformer [Tx] and clamp capacitor [Cc1], [Cc2], the former limit winding of one of them main switch [M1] and transformer [Tx] and DC power supply or active load [V1] are connected into the loop, the secondary winding of another main switch [M2] and transformer [Tx] and DC power supply or active load [V2] are connected into the loop, an auxiliary switch [M3] and clamp capacitor [Cc1] circuit that is in series is connected across the two ends of the former limit of transformer winding, perhaps be connected across two ends with the main switch [M1] of former limit windings in series, another auxiliary switch [M4] and clamp capacitor [Cc2] circuit that is in series is connected across the two ends of transformer secondary winding, perhaps is connected across the two ends with the main switch [M2] of secondary windings in series.

2. by the described a kind of two-way DC-DC converter of claim 1, it is characterized in that the former limit of said transformer winding comprises the inductance [L1] that is in series with it, the secondary winding comprises the inductance [L2] that is in series with it.