CN1106588A

CN1106588A - Whole bridge quasisqure wave soft switch converter

Info

Publication number: CN1106588A
Application number: CN94111637A
Authority: CN
Inventors: 蒋贤华; 潘森
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-02-04
Filing date: 1994-02-04
Publication date: 1995-08-09
Anticipated expiration: 2014-02-04
Also published as: CN1053532C

Abstract

The capacitors are parallelly and one inductor is serially connected in main loop of ordinary full-bridge switching converter, and control circuit and new driver program are used to regulate the width of two groups of pulse signal, but not the other two groups, so realizing 4 switch regulating diodes working at zero current or zero voltage on and off, that is, zero switching state, avoiding switching loss.

Description

Whole bridge quasisqure wave soft switch converter

The present invention relates to the improvement of a kind of full-bridge switch power circuit of each class of electronic devices use.

Along with the develop rapidly of electronics industry, electronic equipment is more and more higher to the requirement of power supply, and as satisfying the output voltage height, power is big, the high requirement of stability, and but some does not catch up with situation to the power technology in past.In the power supply that uses at present, PWM(pulse-width modulation) power technology is occupied an leading position always, but also is difficult to reach requirements such as efficient, high reliability, high-quality, high-power, light littleization.Therefore, high power switching power supply is difficult to promote the use of at electronic technology field, traces it to its cause, and mainly is the switching loss problem.The unique effective means that addresses this problem will realize zero switch exactly, and this is to be difficult to realize in the Switching Power Supply of routine.If utilize resonance manner to realize that zero switch is easier, but do like this, the operating frequency of power supply just can not be constant.So, realize that zero switch also will have individual prerequisite, and can not be cost to sacrifice frequency constant.The difficulty and complicated so problem just becomes.In recent years, we have in depth studied this problem, and the foreigner is also in this problem of research, and some means that address this problem are referred to as soft switch technique.

On the conventional full-bridge switch converter major loop resistance, electric capacity or a resistance, diode, capacitances in series branch road are arranged all generally, this is in order to improve waveform, and cushioning effect slightly, its energisation mode is that V1 and V4 conducting simultaneously end simultaneously, V2 and V3 also conducting simultaneously end simultaneously, and two signal phases of each group are identical, and pulsewidth is also identical, and this is the hard switching operating state.

Task of the present invention is to propose one can make two two control signal pulsewidths on the switches adjustment pipe adjustable, the pulsewidth of two signals is constant in addition, to realize the whole bridge quasisqure wave soft switch converter of zero switch, this converter has overcome the switching loss problem, and have characteristics such as high reliability, high-quality, high-power, light littleization, to satisfy the electronic equipment instructions for use.

Task of the present invention is achieved like this.On full-bridge switch converter major loop, set up two buffer condensers, be connected in parallel on two switching tubes of bridge left arm respectively and a satiable inductor, be connected between left arm two switching tubes and the primary.Switch adjustment pipe adopts power field effect pipe, cooperation is with driving pulse such as the listed new driver of table one by control circuit output, as shown in Table 1, produce control signal by control circuit ... make on the bridge four switches adjust pipe and can both be operated in zero on off state-be soft on off state.

Solution of the present invention can further be used following description of drawings.

Fig. 1 is the type of attachment of main loop circuit figure of the present invention and control circuit block diagram.

Fig. 2 is the control circuit schematic diagram.

Among Fig. 1, FU1 is insurance, and U1 is a silicon rectification bridge, and (50HZ, 220V or 50HZ, 380V) is made into direct current with civil power, by CO filtering, as the input voltage of converter.Power field effect pipe V1, V2, V3, V4, capacitor C 1, C2, inductance L 1, transformer B1 forms full-bridge converter, (10) be the full-bridge converter control signal, be added in G1, the S1 of V1 respectively, the G3 of V3, S3, the G2 of V2 and the G4 of V4 end, when converter realized that soft on off state is worked, it was quasi-square wave that control signal makes the elementary both end voltage of transformer B1, this quasi-square wave voltage is made into direct current through the B1 transformation and after isolating by diode D1 and D2, L2 is used for energy storage, strobes with C3, and voltage is exported by the C3 two ends.

The soft switch operation principle of converter is: when upper half V2 turn-offed, because the existence of C1 and C2, A point current potential can not kick, and for input, V2 realizes the no-voltage shutoff, and V3 still is a conducting state.Along with C1 discharge C2 charging, A point current potential raises gradually then, at last by among the power field effect pipe V1 and the backward diode clamper that connects at the anode of input voltage, so that lower half V1 no-voltage is open-minded.When lower half V1 turn-offed, V4 still be a conducting state, and A point current potential can not kick, the shutoff of V1 realization no-voltage.Along with C1 charging C2 discharge, A point current potential descends gradually then, at last by among the V2 and the backward diode clamper that connects at the negative terminal of input voltage so that the next cycle when beginning the V2 no-voltage open-minded.Because the effect of L1, the output current of bridge can not kick, so upper half V3, when V2 opens and lower half V4, can both realize zero current turning-on when V1 opens.Upper half is before V3 turn-offs, and the V3 electric current has reduced to zero, and V3 becomes zero-current switching naturally, and in like manner, lower half V4 also becomes zero-current switching naturally.This shows that V1, V2, V3, V4 are operated in zero on off state, thereby realized the operating characteristic-promptly zero on off state of soft switch technique.

If V1, V2 adopt general switch adjustment pipe, then a difference clamp diode in parallel on V1, V2 can realize that equally soft switch transducer is operated in zero on off state.

Among Fig. 2, transformer B2 exports two groups of alternating voltages, is distinguished rectifying and wave-filtering and voltage stabilizing.The effect of D3, D4 and D5, D6 is rectification, and the effect of C5, C7 and C6, C8 is filtering, and the effect of N1 and N2 all is a voltage stabilizing output 12V voltage.

N3 is a pulse width modulator, R3 and its operating frequency of C11 decision.9 pin and two square-wave voltages of 10 pin output, phase difference is 180 °, so form upper half and lower half.Two groups of square-wave voltages are added to N4(six non-inverting buffers through D8 and D7 step-down respectively) 5 pin and 3 pin on, 4 pin of N4 and 2 pin are with regard to each output half cycle high level, phase difference is 180 °.These two high level are added to respectively on 11 pin and 14 pin of N3, and 12 pin and 15 pin drive V8 and V10 respectively with regard to each output half cycle high level.V8 drives transformer B3, and B3 level is just at upper half output high level; V10 drives transformer B5, and B5 level is just at lower half output high level.

The output of 4 pin of N4 is made benchmark through 3 pin that R11 and R8 dividing potential drop are added to comparator N5; The output of 2 pin of N4 is made benchmark through 5 pin that R10 and R9 dividing potential drop are added to N5.The 12V voltage negative terminal of N1 output is earth-free, but is provided with a direct current pressure reduction Un, and this pressure reduction is added on the follower of V7, R5 composition through R4 together with the sawtooth waveforms on the C11, so the output of follower is DC level stack sawtooth waveforms.Such signal voltage is added on 2 pin and 6 pin of N5, compares with 3 pin and 5 pin respectively.To be upper half obtain a positive pulse from 1 pin of N5 to the result, and lower half obtains a positive pulse from 7 pin of N5.Two pulse symmetries, width all are τ, 180 ° of phase differences.These two pulses are added to respectively on the amplifier that amplifier that R14, V9 form and R15, V11 form.V9 drives transformer B4, B4 level upper half output driving pulse; V11 drives transformer B6, B6 level lower half output driving pulse.

The τ value is along with the DC level of follower becomes, and this level is along with direct current pressure reduction Un becomes.Un is by the dividing potential drop decision of V6 and R1.The equivalent resistance of V6 is by the dividing potential drop decision of V5 and R2.The equivalent resistance of V5 is by sampling slip (R12, D8, R13, W1) and output voltage V 0 decision.Therefore, after the sampling slip parameter was set up, the τ value was just by the output voltage FEEDBACK CONTROL.The effect of C10 and C9 is to prevent self-oscillation.The effect of D9 is the maximum of restriction Un.

Fig. 1 is one embodiment of the present of invention.FU1 is 10A, and U1: MDA3510, CO are the electric capacity parallel connections of 4 400V, 220UF, and V1, V2, V3 and V4 are IRF450, and C1 and C2 are 1KV, 2200PF, and L1 is 3UH, and D1 and D2 are MUR3060, and L2 is 30UH, and C3 is two 100V, the parallel connection of 470UF electric capacity.The components and parts of control circuit (10) are selected and parameter sees figure two for details.It touches the mark as follows:

Civil power scope: 180-260V

Output voltage: 60V

Output current: 12.5A

Voltage stability: Sv=0.22 * 10 ^-2

Current stability: Si=0.44 * 10 ^-2

Overall efficiency: 0.90

The present invention compared with prior art has the following advantages:

1. solve switching loss problem in the full-bridge switch converter, namely realized zero switch.

2. owing to solved the switching loss problem, make switch adjustment plumber do safe and reliable.

The present invention have efficiently, high reliability, high-power, light characteristics such as small and exquisite.

4. reliable at high (45 ℃) low (20 ℃) startup temperature.

Table one, the level of drive of V1, V2, V3, V4

	0～τ	τ～(T/2)	(T/2)～(1/2)+τ	(T/2)+τ～T
					The excitation of V1	Low	Low	High	Low
The excitation of V2	High	Low	Low	Low
					The excitation of V3	High	High	Low	Low
The excitation of V4	Low	Low	High	High

Claims

1, a kind of full-bridge switch converter, by switch adjustment pipe V1, V2, V3, V4 (electric bridge of formation), transformer B1, diode D5, D6, inductance L 2, capacitor C 3 (the transformation of formation, rectification, the perception filter circuit) etc. the major loop and the control circuit (10) that constitute of main components and parts formed, it is characterized in that in major loop, setting up two buffer capacitor C1, C2, be connected in parallel on V1 respectively, on the V2, set up a pulsactor L1 again, be connected on V1, between V2 and transformer B1 elementary, V1, V2 adopts power field effect pipe, cooperate the listed driver of table one, can realize V1, V2 turns on and off in no-voltage, V1, V2, V3 and V4 are at zero current turning-on.

2, according to said full-bridge switch converter in the claim 1, it is characterized in that V1, V2 also can adopt general switch adjustment pipe, this moment is a difference clamp diode in parallel on V1, V2.