CN103001471B

CN103001471B - Low power consumption and high reliability XC/DC power-switching circuit

Info

Publication number: CN103001471B
Application number: CN201210517229.3A
Authority: CN
Inventors: 胡家培; 胡民海
Original assignee: Individual
Current assignee: Individual
Priority date: 2012-11-30
Filing date: 2012-11-30
Publication date: 2016-06-08
Anticipated expiration: 2032-11-30
Also published as: CN103001471A

Abstract

The present invention provides a kind of low power consumption and high reliability XC/DC power-switching circuit, the problem mainly solving the power supplying efficiency of electric power system of renewable new energy resources system that AC low-tension, the DC low-voltages such as photovoltaic generation, wind-power electricity generation, storage battery power supply power, power supply quality, power supply reliability difference. This low power consumption and high reliability XC/DC power-switching circuit includes VMOS on-off circuit and width modulation type pulse control circuit, the input of VMOS on-off circuit is connected with the outfan of input power by afterflow inductance, and the outfan of VMOS on-off circuit passes sequentially through reverse isolation circuit, energy storage filter circuit is connected with load.

Description

Low power consumption and high reliability XC/DC power-switching circuit

Technical field

The present invention relates to a kind of power-switching circuit.

Background technology

In recent years, the renewable new energy resources system that AC low-tension, the DC low-voltage such as photovoltaic generation, wind-power electricity generation, storage battery power supply are powered is widely used, and improves the power supplying efficiency of low pressure new energy system, power supply quality, power supply reliability imperative.

Current Power convert known in this field adopts substantially:

1, exchange (AC) input, adopt full wave rectifier be direct current (DC) power supply input AC (AC) power rectifier, then carry out DC/DC be converted to direct current (DC) output. This kind of scheme solves the transfer problem of high-line input voltage alternating current power supply and small-power power. But when the input of low-voltage AC power supply and large power supply conversion, because the voltage drop of AC/DC rectification circuit is higher, and produce significantly high power consumption, make power supply changeover device conversion efficiency very low.

2, direct current (DC) input, is made directly DC/DC and is converted to direct current (DC) output. This kind of scheme solves fixing equipment powerup issue. But dependability is relatively low, particularly in mobility equipment, it is often necessary to reconnecting the equipment of input power, once occur that electric power polarity connects anti-situation, input short accident will be produced. More therefore require the equipment that reliability is higher, add direct current orientation rectification circuit at switch input. When the straight power supply input of low-voltage and large power supply conversion, because the voltage drop of direct current identification orientation rectification circuit is higher, and produce significantly high power consumption, make power supply changeover device conversion efficiency very low.

3, it is generally adopted boost type (BOOST) direct current (DC) power supply mode to improve low-voltage power supply efficiency, reducing line current. Boost type (BOOST) direct current (DC) power supply produces short trouble when output, and when output voltage is lower than input voltage, BOOST circuit function lost efficacy, and input power is directly to load short circuits, and it is very big that the protection of big electric current (high-power) system short-circuit controls difficulty.

Illustrate for low pressure new forms of energy power supply for conventional rectification (identifying orientation) circuit in input, input voltage Ui=10V (AC, DC), input current Ii=20A, input power Pi=10 �� 20=200W, rectification (identification orientation) circuit pressure drop Ud=2V, rectification (identifies orientation), and circuit consumption is: Pd=2 �� 20=40W, output Po=200-40=160W, its rectification (identifies orientation), and efficiency is: E=160/200=0.8, conventional rectification (identifying orientation) circuit is when input is for low pressure new forms of energy power supply as can be seen here, power consumption is very big, and efficiency is very low.

Summary of the invention

The present invention provides a kind of low power consumption and high reliability XC/DC power-switching circuit, mainly solves that existing low pressure new energy power converter power consumption is high, efficiency is low, the problem of poor reliability.

The concrete technical solution of the present invention is as follows:

This low power consumption and high reliability XC/DC power-switching circuit, including VMOS on-off circuit and width modulation type pulse control circuit, the input of VMOS on-off circuit is connected with the outfan of input power by afterflow inductance, the outfan of VMOS on-off circuit passes sequentially through reverse isolation circuit, energy storage filter circuit is connected with load, the input of described VMOS on-off circuit is also connected with the outfan of VMOS switch driving circuit, the outfan of described width modulation type pulse control circuit is connected with the input of VMOS switch driving circuit by driving signal synthesis circuit, the input of width modulation type pulse control circuit is connected with the outfan of input power by input current sample circuit, the input of driving signal synthesis circuit is connected also by the outfan of afterflow voltage sampling circuit with VMOS on-off circuit, the input of described width modulation type pulse control circuit is connected with the outfan of energy storage filter circuit also by output current sampling circuit, described width modulation type pulse control circuit, driving signal synthesis circuit, VMOS switch driving circuit and afterflow voltage sampling circuit composition control circuit, described VMOS on-off circuit includes the VMOS pipe group of two series connection, and input power was connected before reverse isolation circuit input end with two VMOS pipe groups successively by afterflow inductance.

Described VMOS switch driving circuit includes two drivers in parallel, and each driver is connected with the input of two VMOS pipe groups respectively.

Described driving signal synthesis circuit is that standard two inputs or gate control chip, and this control chip includes four couples of inputs A1, A2, B1, B2, C1, C2, D1, D2 and corresponding four output terminals A o, Bo, Co, Do, wherein input A1, B1, C1, D1 is connected with two outfans of width modulation type pulse control circuit, input A2, B2, C2, D2 are connected with two outfans of afterflow voltage sampling circuit, output terminals A o, Bo, Co, Do and VMOS switch driving circuit input connect.

Described width modulation type pulse control circuit is the PWM controller that push-pull type controls, and two output terminals A o, Bo of PWM controller are respectively connected to drive one group of input of signal synthesis circuit.

Described input current sample circuit includes current sensor CS1, electric capacity C13, resistance R21, diode D4, current sensor CS1 and a diode D4 branch road in series, electric capacity C13, resistance R21 respectively with this branch circuit parallel connection.

Described output current sampling circuit includes current sensor CS2, electric capacity C9 and diode D5, current sensor CS2 and a diode D5 branch road in series, electric capacity C9 and this branch circuit parallel connection.

It is an advantage of the current invention that:

Low power consumption and high reliability XC/DC power-switching circuit provided by the invention has XC/DC to extend (XC) shape, waveform nonpolarity, many, wild frequency power input, DC (direct current) exports, the advantage such as auto polarity identification orientation, high conversion efficiency, High Power Factor, high reliability, high power density, low cost.

Accompanying drawing explanation

Fig. 1 is schematic block circuit diagram of the present invention;

Fig. 2 is electrical block diagram of the present invention;

Fig. 3 is automatic orientation BOOST electric current flow graph when Ui positive half cycle (M1, M2, M3, M4) PWM turns on;

Fig. 4 is automatic orientation BOOST electric current flow graph when Ui positive half cycle (M3, M4) PWM turns on afterflow;

Fig. 5 is input power is monocycle oscillogram during Ac sine wave.

Detailed description of the invention

Hereinafter the function of each Important Circuit is illustrated:

Afterflow inductance: utilize inductance characteristic that input power is boosted;

VMOS on-off circuit: during the conducting of VMOS on-off circuit, have electric current to pass through in afterflow inductance; During VMOS on-off circuit turns off, freewheeling circuit turns on, and makes electric current in afterflow inductance continue conducting, produces high pressure, energy storage filter circuit is charged, by energy storage filter circuit, load is powered after charging;

Energy storage filter circuit: VMOS on-off circuit charges and to load supplying during turning off;

VMOS switch driving circuit: be amplified processing to the VMOS switching signal driving signal synthesis circuit to generate and VMOS afterflow signal;

Drive signal synthesis circuit: PWM width modulation type pulse signal, the alternating current-direct current signal of voltage sampling circuit input, both positive and negative polarity signal or afterflow signal that width modulation type pulse control circuit is generated and power supply signal synthesize, and generate composite signal (including polarity, exchange, direct current, tune bandwidth signals); Then automatically distribute according to composite signal, divide into VMOS switching signal and VMOS afterflow signal;

Width modulation type pulse control circuit: generate PWM width modulation type pulse signal according to the current sampling signal of input sampling circuit and/or output sample circuit input;

Afterflow voltage sampling circuit: the current signal of VMOS on-off circuit and freewheeling circuit is sampled, produces alternating current-direct current signal, both positive and negative polarity signal or afterflow signal, and inputs above-mentioned signal to driving signal synthesis circuit;

Input current sample circuit: input power input is sampled through the electric current of afterflow inductance, generates sampled signal and sampled signal is supplied to width modulation type pulse control circuit processes;

Below in conjunction with accompanying drawing, the present invention is described in detail:

IC1 (UCC28084 or other similar device), alternately exports PWM controller for standard both-end, controls PWM by device 1 end (OC) and adjusts width output, exports alternative P WM waveform P1, P2.

Afterflow waveform PA is carried out detection shaping by R1, R5, C12, Z4, forms waveform P3. Wherein, stabilivolt Z4 keeps the voltage stabilization of P3, and electric capacity C12 is in order to filter so that can make P3 permanent High level when high level occurs in PA.

Afterflow waveform PB is carried out detection shaping by R4, R3, C11, Z3, forms waveform P4. Wherein, stabilivolt Z3 keeps the voltage stabilization of P4, and electric capacity C11 is in order to filter so that can make P4 permanent High level when high level occurs in PB.

IC2 (CD4071 or other similar device), inputs or door for standard 2, wherein: Ao=A1+A2, Bo=B1+B2, Co=C1+C2, Do=D1+D2, forms staggered output pwm waveform after P1, P2, P3, P4 carry out logic synthesis.

IC3, IC4 (IR442 or other similar device), for standard drive, wherein: Ao=Ai, Bo=Bi, carry out high speed large driven current density to VMOS, improves conversion efficiency reducing VMOS switching power loss.

CS1, CS2, D4, D5, R21, C13 form current sense, discriminating, testing circuit, automatically detect the current waveform that when PWM opens, the high-end VMOS of power supply passes through. Its circuit super has very low power consumption simultaneously, adopts current sense coefficient 100, controlling of sampling voltage 0.5V, controls power consumption Pe 0.5 �� IO �� 0.01=0.005 �� IO (IO is On current), when IO is 20A: Pe 0.05 �� 20=0.1W.

C7, C8, C9 are mainly used in eliminating noise (burst pulse) further.

L1, D3, C14 form the LDC of BOOST booster circuit, in order to adapt to the unsymmetry of input power, such as unipolarity direct current, unipolarity square wave, unipolarity triangular wave etc., L1 adopts differential mode symmetrical expression, it is possible to only arrange inductance as L1 at the anode of input circuit or negative terminal.

The Ao port of pwm control circuit (IC1) and Bo port alternately output control signal P1, P2, and one interval time (high level corresponding to PA waveform) for afterflow of total maintenance between P1, P2. P3, P4 are by PA, PB waveform dividing potential drop gained in input circuit. P1, P2, P3, P4 access the input port triggering signal synthesis circuit (IC2), after carrying out foregoing or logical operations, then drive through switch driver IC3, IC4 respectively triggering signal adds to two VMOS on-off circuit group (M1, M2 respectively;M3, M4), D3 has two inputs, is respectively connected to anode and the negative terminal of input circuit, and C14 is charged by forward current through reverse isolation circuit D3.

M1 and M2 parallel connection alternation, M3 and M4 parallel connection alternation (each VMOS switch itself has diode in parallel with it).

Bear just down on the positive half cycle of waveform or input direct-current are at input AC, when one of control signal P1 and P2 that pwm control circuit (IC1) exports is in high level, this XC/DC automatic orientation BOOST circuit is in PWM conducting state, electric current flows through first group of VMOS on-off circuit group (M1, M2), second group of VMOS on-off circuit group (M3, M4) successively in input circuit from anode, then flows back to negative terminal; Owing to D3 plays reverse isolation effect, the energy storage on C14 reverse flow will not be fed back into loop.

When control signal P1, P2 that pwm control circuit (IC1) exports are low level, M1, M2 then do not trigger signal, therefore M1, M2 are not turned on, but the existence due to afterflow inductance L1, and the diode in M3, M4 can form the conducting loop from ground end to input circuit negative terminal, so that C14 is charged through D3 by the afterflow produced because of afterflow inductance in circuit from the anode of input circuit, and simultaneously via the load of output loop, second group of VMOS on-off circuit group (M3, M4), then flow back to negative terminal. It practice, once there is above-mentioned afterflow in circuit, namely PA is high level, PB is low level, so that P1, P2, P3, P4 carry out or produce after logical operations to trigger signal, M3, M4 is made to turn on, owing to the resistance of M3, M4 is only small, therefore, the power consumption produced in afterflow process is still only small. And, boosting output itself can reduce line loss. Such as, Ui=10 (V), Uo=50 (V) after boosting, then according to P=U²/ R is it can be seen that line loss is only original 1/5.

Illustrate the low-power consumption of the present invention: circuit adopts R_DS=0.001 �� low on-resistance N-channel VMOS pipe, opens the staggered conducting of period M1, M2, VMOS conducting resistance R at PWM_DSThe two-tube paralleling and interleaving conducting of=0.001 ��, M3, M4, VMOS conducting resistance R_DS=0.001 ��/2=0.0005 ��, if or input 20A electric current, then conducting voltage is: U1=0.001 �� 20=0.02V, U2=0.0005 �� 20=0.01V, identifies that directed power consumption is: Pe=20 �� (0.02+0.01)=0.6W; Turn off period M1, M2 cut-off at PWM to turn off, the two-tube paralleling and interleaving conducting afterflow of M3, M4, VMOS conducting resistance R_DS=0.001 ��/2=0.0005 ��, if 20A freewheel current, then conducting voltage is: U2=0.0005 �� 20=0.01V, identifies that directed power consumption is: Pe=20 �� 0.01=0.2W. Comparing to the power consumption of the rectification identification directional circuit 40W of prior art, the XC/DC of the present invention identifies that directed BOOST circuit power consumption significantly reduces automatically.

If reverse isolation circuit D3 is also adopted by the VMOS on-off circuit (it triggers the synchronous waveform of signal and PA and PB) synchronized, then the characteristic that available VMOS on-off circuit resistance is little reduces line loss further. Especially when BOOST output is relatively low, the raising of conversion efficiency is more notable.

VMOS switch is under triggering signal function, can realize turning on forward or backwards according to added polarity of voltage, based on this characteristic, in input AC negative lower timing on waveform negative half period or input direct-current are, the work process of this XC/DC automatic orientation BOOST circuit and above-mentioned conducting, afterflow Principle of Process are identical, and owing to first group of VMOS on-off circuit group (M1, M2) and second group of VMOS on-off circuit group (M3, M4) adopt symmetric circuit structure, be completely reversibility in Ui negative half period VMOS conducting and afterflow.Such as, when control signal P1, P2 that pwm control circuit (IC1) exports are low level, then not triggering signal on M3, M4, therefore M3, M4 are not turned on, and are realized afterflow process by first group of VMOS on-off circuit group (M1, M2).

Visible, this BOOST circuit can be automatically performed and bipolar power supply (exchanging just profound ripple, square wave, triangular wave, AC power frequency, intermediate frequency, low frequency, intrasonic) is identified orientation automatically; And unipolarity power supply (direct current, direct current square wave, direct current triangular wave etc.) identified that orientation, AC bi-polar power supply and direct current unipolarity power supply can regardless of positive and negative any accesses automatically.

Above-described embodiment is highly preferred embodiment of the present invention, adopts this staggered PWM control mode to make the staggered conducting of M1, M2, and each VMOS switch operating frequency is 1/2 channel frequency, it is possible to make VMOS switch work under relatively low switching frequency, switching power loss is greatly reduced; Correspondingly, in circuit, the operating frequency of L, C device is 2 times of VMOS pipe frequencies, and higher circuit work frequency reduces the requirement to inductance in lc circuit (L) amount and electric capacity (C), reduces cost and technology difficulty. It practice, based on the ultimate principle of the conducting of the present invention, afterflow, it is also possible to consider that each VMOS on-off circuit group switchs only with a VMOS, be also enough to embody the technique effect of the present invention. Such as only retain M1, M3, also be able to equally when input AC is born just down on the positive half cycle of waveform or input direct-current are, M1, M3 realize conducting loop, M3 realize continuous current circuit; In input AC negative lower timing on waveform negative half period or input direct-current are, M1, M3 realize conducting loop, M1 realize continuous current circuit. Certainly, under this scheme, it is also possible to attempt allowing each VMOS operating frequency switch reduce by half, but this is accomplished by increase afterflow inductance, storage capacitor exponentially, to meet the requirement of afterflow, thus causing that relatively costly, components and parts volume is relatively big, power density reduction.

Claims

1. a low power consumption and high reliability XC/DC power-switching circuit, it is characterized in that: include VMOS on-off circuit and width modulation type pulse control circuit, the input of VMOS on-off circuit is connected with the outfan of input power by afterflow inductance, the outfan of VMOS on-off circuit passes sequentially through reverse isolation circuit, energy storage filter circuit is connected with load, the input of described VMOS on-off circuit is also connected with the outfan of VMOS switch driving circuit, the outfan of described width modulation type pulse control circuit is connected with the input of VMOS switch driving circuit by driving signal synthesis circuit, the input of width modulation type pulse control circuit is connected with the outfan of input power by input current sample circuit, the input of driving signal synthesis circuit is connected also by the outfan of afterflow voltage sampling circuit with VMOS on-off circuit, the input of described width modulation type pulse control circuit is connected with the outfan of energy storage filter circuit also by output current sampling circuit, described width modulation type pulse control circuit, driving signal synthesis circuit, VMOS switch driving circuit and afterflow voltage sampling circuit composition control circuit, described VMOS on-off circuit includes the VMOS pipe group of two series connection, and input power was connected before reverse isolation circuit input end with two VMOS pipe groups successively by afterflow inductance,

Described VMOS switch driving circuit includes two drivers in parallel, and each driver is connected with the input of two VMOS pipe groups respectively;

Described driving signal synthesis circuit is that standard two inputs or gate control chip, this control chip includes two groups and amounts to four couples of inputs A1, A2, B1, B2, C1, C2, D1, D2 and corresponding four output terminals A o, Bo, Co, Do, wherein in first group of input, input A1 and input C1 is connected to the first outfan of width modulation type pulse control circuit altogether, and input B1 and input D1 is connected to the second outfan of width modulation type pulse control circuit altogether; In second group of input, input A2 and input B2 is connected to the first outfan of afterflow voltage sampling circuit altogether, and input C2 and input D2 is connected to the second outfan of afterflow voltage sampling circuit altogether; Output terminals A o, Bo, Co, Do and VMOS switch driving circuit input connect;

Described width modulation type pulse control circuit is the PWM controller that push-pull type controls, and two output terminals A o, Bo of PWM controller are connected to the first group of input driving signal synthesis circuit.

2. low power consumption and high reliability XC/DC power-switching circuit according to claim 1, it is characterized in that: described input current sample circuit includes current sensor CS1, electric capacity C13, resistance R21 and diode D4, current sensor CS1 and diode D4 the first branch road in series, electric capacity C13, resistance R21 respectively with described first branch circuit parallel connection.

3. low power consumption and high reliability XC/DC power-switching circuit according to claim 2, it is characterized in that: described output current sampling circuit includes current sensor CS2 and diode D5, current sensor CS2 and diode D5 the second branch road in series, output current sampling circuit and input current sample circuit share described electric capacity C13 and resistance R21, namely described electric capacity C13, resistance R21 also respectively with described second branch circuit parallel connection.