CN203151389U - Control circuit of three-phase high power factor rectifier - Google Patents

Abstract

The utility model discloses a control circuit of a three-phase high power factor rectifier, and belongs to the field of electric control. The control circuit comprises an input high-frequency filter circuit, a three-phase input inductor and a three-phase rectifier circuit, and also comprises a switching tube power circuit, an output rectification filter circuit, a voltage dividing detection circuit, an input current detection unit, a single cycle controller and a switching tube drive circuit. The control circuit of the three-phase high power factor rectifier can realize three-phase high power factor rectification, can obtain steady-state output voltage of relatively high precision, and has a strong anti-interference capability.

Description

A kind of control circuit of three-phase high power factor rectifier

Technical field

The present invention relates to the electrical control field, more particularly, relate to a kind of employing monocycle Single-phase PFC chip, the three-phase circuit after the decoupling zero is controlled, realized the rectifier of three-phase high power factor input.

Background technology

Along with development and national economy, various power consumption equipments are more and more.Because what the input of power consumption equipment was adopted mostly is non-controlled rectification mode, the harmonic content of power consumption equipment input electric current is very high, has so just brought a large amount of " harmonic pollution " to electrical network, and has increased the loss of electrical network.In order to reduce device to harmonic pollution and the electromagnetic interference of electrical network, corresponding harmonic suppressing method and power factor correction circuit have been proposed, therefore needing increases one-level power factor correction (Power Factor Correction in the input of power consumption equipment, PFC) device is to reduce the input harmonic pollution and to improve power factor.The Single-phase PFC Study on Technology is very ripe, existing many integrated control chips, and as UC3854, IRll50S, LTl508, ML4819 etc., and three-phase PFC rectifying device has more advantage: (1) input power is higher, can reach more than several kilowatts; (2) the pulsation sum of three-phase input power is zero, and the pulsation of output work power is single-phase 1/3rd, and it is less that output capacitance can obtain, and the dynamic response of rectifier is faster.Three-phase PFC technology is still in recent years the focus of research both at home and abroad.

The research of three-phase high power factor commutation technique mainly concentrates on PWM control mode and the topological structure, at present based on the existing big quantity research of different topological structures.China's magazine " Proceedings of the CSEE " 06 phase document in 2012 " High power because of Number three-phase single tube Boost pfc converter" with " electrician's electric energy new technology " 2003 02 phase document " research of biswitch three-phase and four-line pfc circuit " a kind of topological structure that has adopted single switch and biswitch has been proposed, number of switches is less, control is simple, but because the switch stress of switching device is bigger, and circuit working is in DCM(discontinuous current pattern) under the pattern, THD is still bigger.Adopt six switch topology based on digital DSP control in " A Universal Vector Controller for Four-Quadrant Three-Phase Power Converters " literary composition, adopt six switching tubes, number of switches is more, conduction loss is big, the control algolithm more complicated is difficult for realizing.

Summary of the invention

1. the technical problem that will solve

At when control is simple relatively, controlling effect shortcoming relatively poor and that when effect is better, controls complexity and be difficult to realize in the prior art, the invention provides a kind of control circuit of three-phase high power factor rectifier, it can realize the three-phase high power factor rectification, can obtain the stable state output voltage of degree of precision, antijamming capability is strong, and is easy to realize.

2. technical scheme

Purpose of the present invention is achieved through the following technical solutions:

A kind of control circuit of three-phase high power factor rectifier, comprise input high-frequency filter circuit, three-phase input inductance and rectified three-phase circuit, also comprise switching tube power circuit, output rectifier and filter, voltage-dividing detection circuit, input current detecting unit, single cycle controller and switching tube drive circuit;

Described input high-frequency filter circuit comprises three high-frequency filter capacitor C that parameter is identical _a, C _bAnd C _c, C _a, C _bAnd C _cAn end respectively correspondence be connected to electrical network A phase voltage input, electrical network B phase voltage input and electrical network C phase voltage input, the other end is connected to the neutral line of three-phase and four-line electricity, neutral earthing simultaneously;

Described three-phase input inductance comprises three high frequency BOOST inductance L that parameter is identical _a, L _bAnd L _c

Described rectified three-phase circuit comprises three brachium pontis, i.e. A phase brachium pontis, B phase brachium pontis and C brachium pontis mutually;

Described switching tube power circuit comprises three bidirectional switch pipe S _a, S _bAnd S _cElectrical network A phase input voltage is through inductance L _aBe connected to A phase brachium pontis mid point A and bidirectional switch pipe S _aAn end, electrical network B phase input voltage is through inductance L _bBe connected to B phase brachium pontis mid point B and bidirectional switch pipe S _bAn end, electrical network C phase input voltage is through inductance L _cBe connected to C phase brachium pontis mid point C and bidirectional switch pipe S _cAn end; Described bidirectional switch pipe S _a, S _bAnd S _cThe other end insert network neutral line simultaneously and driven by the switching tube drive circuit;

Described rectified three-phase circuit, output rectifier and filter and voltage-dividing detection circuit are connected successively; Described single cycle controller is connected with voltage-dividing detection circuit, input current detecting unit and switching tube drive circuit respectively; Described input current detecting unit detects the inductance L of flowing through respectively _a, L _bAnd L _cAfter electric current.

Preferably, described bidirectional switch pipe S _a, S _bAnd S _cEach is by four rectifier diode D _I1, D _I2, D _I3, D _I4With an IGBT pipe K _iForm D _I2Negative electrode and D _I1Anode links to each other, D _I1Negative electrode be connected to inductance one end in the i circuitry phase, D _I4Negative electrode and D _I3Anode links to each other, D _I3Negative electrode be connected to center line, D _I1Negative electrode, D _I3Negative electrode and the collector electrode of IGBT link together D _I2Anode, D _I4Anode and the emitter of IGBT link together, wherein, i=a, b, c, the grid of IGBT pipe is connected with the switching tube drive circuit.

Preferably, described rectified three-phase circuit comprises six fast recovery diode D _Ap, D _Bp, D _Cp, D _An, D _BnAnd D _Cn, D _ApAnode and D _AnNegative electrode be connected to form A phase brachium pontis, D _BpAnode and D _BnNegative electrode be connected to form B phase brachium pontis, D _CpAnode and D _CnNegative electrode be connected to form C phase brachium pontis, D _Ap, D _Bp, D _CpNegative electrode link together D simultaneously _An, D _BnAnd D _CnAnode link together.

Preferably, described output rectifier and filter comprises two output electrochemical capacitor C _p, C _n, described output electrochemical capacitor C _pNegative pole and described output electrochemical capacitor C _nPositive pole link to each other, tie point connects to neutral, described output electrochemical capacitor C _pPositive pole connect D _Ap, D _BpAnd D _CpNegative electrode, described output electrochemical capacitor C _nNegative pole connect D _An, D _BnAnd D _CnAnode.

Preferably, described voltage-dividing detection circuit comprises output voltage sampling resistor R _FB1, R _FB2, output under voltage sampling resistor R _BOP1, R _BOP2With output over-voltage sampling resistor R _OVP1, R _OVP2, each is organized and is connected in parallel on output capacitance C after voltage sample resistance is in series _pTwo ends, and draw lead from the junction of each group voltage sample resistance series connection and insert described single cycle controller respectively.

Preferably, described single cycle controller comprises three monocycle Single-phase PFC control chip IR1153S, output voltage U _oSampling value V _FBBe connected to the VFB pin of three chip I R1153S respectively, with the chip internal reference voltage V _REFDifference relatively obtains V through the PI demodulator _m(being produced by pin COMP), the COMP pin of three chips is parallel to a bit, shares an external circuits again, constitutes a voltage error amplifying element, guarantees the voltage error value of magnification V of every phase _mIdentical, thus reach desirable control effect, output over-voltage sampled voltage V _OVPReceive the OVP mouth of three chips respectively, when this voltage greater than chip in given magnitude of voltage, three road output duty cycle signals are all zero, play the effect of overvoltage protection, output under voltage sampled voltage V _BOPReceive the BOP mouth of three chips respectively, this magnitude of voltage blocks three road duty cycle signals during less than the chip set point simultaneously, plays the effect of soft start; Described switching tube drive circuit is made of M57959L chip and peripheral circuit thereof.

Preferably, described input current detecting unit comprises three input current sample circuits, and each input current sample circuit is connected and composed successively by current sensor and current signal absolute value amplifying circuit; The input of described three current sensors three road inductive current values of sampling respectively, the output signal of described inductive current sampling is connected with single cycle controller through the output of absolute value amplifying circuit.

Inventive principle: based on the control circuit of three-phase high power factor rectifier of the present invention, as if S when A phase input voltage is in positive half period _aOpen-minded, L then _aForward current constantly increases, and works as S _aDuring shutoff, the last brachium pontis diode D of rectifier bridge _ApConducting, L _aGive capacitor C _pReturn the load power supply in the time of charging, L _aForward current constantly descends; Opposite to S when A phase input voltage is in negative half-cycle _aOpen-minded, L then _aReverse current constantly increases, as switching tube S _aDuring shutoff, the following brachium pontis diode D of rectifier bridge _AnConducting, L _aGive capacitor C _nIn charging time, is powering load also, L _aReverse current constantly descends; Work as S _aDuring conducting, inductance L _aBoth end voltage is line voltage U _aS _aDuring shutoff, if U _aBe in positive half cycle, inductance L _aBoth end voltage is U _a-U _P(U _PBe C _pBoth end voltage), if line voltage is in negative half period, inductance L _aBoth end voltage is U _a-U _N(U _NBe C _nBoth end voltage); By weber balance can get U _a=(1-D _a) U _P(U _a0) ,-U _a=(1-D _a) U _N(U _a＜0), when circuit reaches stable state, the electric voltage equalization on two electric capacity and be output voltage U _oHalf, i.e. U _P=U _N=0.5U _oTherefore, | U _a|=0.5(1-D _a) U _o(D _aBe duty ratio in the switch periods, C _pPositive pole and C _nThe voltage that forms of negative pole be output voltage U _o);

Output voltage U _oOutput voltage sampled value V _FBBe connected to the VFB pin of chip I R1153S, with the chip internal reference voltage V _REFDifference relatively obtains V through the PI demodulator _m(being produced by pin COMP); S when switch periods begins _aConducting, inductance L _aBoth end voltage is line voltage U _a, current sensor sampling input current signal, obtain the voltage signal of alternation after, behind the absolute value amplifying circuit, obtain positive voltage signal and access control chip I R1153S current sampling signal input, form electric current loop; Inductive current is behind the absolute value amplifying circuit at this moment, and its output valve constantly increases, and the output of integrator constantly reduces, S when current sampling data is exported greater than integrator _aTurn-off, when switch periods finishes, integrator is resetted, so constantly repeatedly, obtain required duty cycle signals; So opening duty ratio, each phase sampler electric current of each cycle and its switching tube satisfy: V _m(1-D _a)=V _IaOpening the duty ratio magnitude relationship in conjunction with sample rate current and its switching tube can obtain: U _a=U _oV _Ia/ 2V _m, under the stable state, U _o, V _mBe steady state value, V _Ia=ki _aAnd k is constant, note R _e=kU _o/ 2V _m, U then _a=R _ei _aThereby the output loading of A phase can equivalence be a pure resistor load, makes input current waveform follow its phase voltage and becomes sinusoidal variations, and the phase angle is zero, has realized unity power factor;

Phase B, phase C are identical with the operation principle of phase A, and therefore for the three-phase input, each single-phase output loading can equivalence be a pure resistor load, and equal and opposite in direction;

The COMP pin parallel connection of three IR1153S chips shares an external PI regulating circuit (by C _Z, C _P, R _GmForm), obtain identical output voltage error amplifying signal V _m, output over-voltage sampled voltage V _OVPBe connected to three monocycle control chip respective pins simultaneously, when this voltage greater than chip in given magnitude of voltage, the output duty cycle signal is zero, output voltage reduces; Output under voltage sampled voltage V _BOPBe connected to three monocycle control chip respective pins simultaneously, before this magnitude of voltage is less than the chip set point, block duty cycle signals.

3. beneficial effect

Than prior art, the invention has the advantages that:

(1) the present invention adopts the strategy of monocycle control, and control method is simple, and required detection limit is less, and only need to sample input current and output voltage have improved the stability of system to a certain extent;

(2) the present invention adopts the topological structure of three-phase four-wire system, analyze the decoupling zero that has realized between the three-phase in theory, separate between the three-phase after the decoupling zero, circuit still can operate as normal when voltage ripple of power network or phase shortage, the antijamming capability of system is strong, and the voltage that switching tube bears under this topology is output voltage half, and switch stress is little, and the rectification brachium pontis does not have straight-through dangerous when electric current commutates;

(3) the present invention adopts ripe single-phase monocycle control chip to control corresponding phase respectively, make this phase current follow its voltage and become sinusoidal variations, reduced product development cycle so greatly, and the chip periphery wiring is simple, resulting three-phase rectifier input power factor height, stability is high, and antijamming capability is strong, is with a wide range of applications.

Description of drawings

Fig. 1 is functional-block diagram of the present invention;

Fig. 2 is current sample absolute value amplification circuit diagram;

Fig. 3 is the peripheral winding diagram of three monocycle control chip IR1153S;

Fig. 4 is the bidirectional switch circuit diagram;

Fig. 5 is monocycle control principle figure.

Among the figure: 1, input high-frequency filter circuit; 2, three-phase input inductance; 3, rectified three-phase circuit; 4, switching tube power circuit; 5, output rectifier and filter; 6, voltage-dividing detection circuit; 7, input current detecting unit; 8, single cycle controller; 9, switching tube drive circuit.

Embodiment

Below in conjunction with Figure of description and specific embodiment, the present invention is described in detail.

Embodiment

The control circuit of the three-phase high power factor rectifier of present embodiment, as shown in Figure 1, it comprises input high-frequency filter circuit 1, three-phase input inductance 2, rectified three-phase circuit 3, switching tube power circuit 4, output rectifier and filter 5, voltage-dividing detection circuit 6, input current detecting unit 7, single cycle controller 8 and switching tube drive circuit 9.

Input high-frequency filter circuit 1 comprises that three withstand voltages are 630V, and size is the ceramic condenser C of 2.2uF _a, C _bAnd C _c, C _a, C _bAnd C _cAn end respectively correspondence be connected to electrical network A phase voltage input, electrical network B phase voltage input and electrical network C phase voltage input, the other end is connected to the neutral line of three-phase and four-line electricity, neutral earthing simultaneously.Three-phase input inductance 2 comprises that three inductance value are the high frequency BOOST inductance L of 400uH _a, L _bAnd L _cRectified three-phase circuit 3 comprises the fast recovery diode D that six models are G80N60 _Ap, D _Bp, D _Cp, D _Bn, D _AnAnd D _Cn, D _ApAnode and D _AnNegative electrode be connected to form A phase brachium pontis, tie point is A, D _BpAnode and D _BnNegative electrode be connected to form B phase brachium pontis, tie point is B, D _CpAnode and D _CnNegative electrode be connected to form C phase brachium pontis, tie point is C.D _Ap, D _Bp, D _CpNegative electrode link together D simultaneously _An, D _Bn, D _CnAnode link together.

Switching tube power circuit 4 comprises three bidirectional switch pipe S _a, S _bAnd S _cAs Fig. 4, each bidirectional switch pipe is by rectifier bridge KPBC3510 and the IGBT pipe K that model is K75T60 _iCompose in parallel (i=a, b, c), one of bidirectional switch pipe terminates at the mid point of corresponding brachium pontis, the other end neutral line that gets access to grid.Rectified three-phase circuit 3, output rectifier and filter 5 and voltage-dividing detection circuit 6 are connected successively, single cycle controller 8 is connected with voltage-dividing detection circuit 6, input current detecting unit 7 and switching tube drive circuit 9 respectively, and described input current detecting unit 7 detects the inductance L of flowing through respectively _a, L _bAnd L _cAfter electric current.

Output rectifier and filter 5 comprises that two appearance values are 1000uH, the withstand voltage electrochemical capacitor C that is 630V _pAnd C _n, C _pNegative pole and C _nPositive pole link to each other tie point ground connection, C _pPositive pole connect D _ApNegative electrode, C _nNegative pole connect D _AnAnode.Export the two ends C of two electric capacity _pPositive pole and C _nThe voltage that forms of negative pole namely be the output voltage U of rectifier _o, load R _oBe connected in the output of rectifier in parallel.

As Fig. 2, shown in Figure 3, single cycle controller 8 comprises three monocycle Single-phase PFC control chip IR1153S, and the power supply of three Single-phase PFC control chips is 15V, and three chip blocks use a power supply, and earth signal COM pin is connected to the electrical network center line.With output voltage sampled voltage V _FBReceive the VFB pin of three chips respectively, as outer voltage, obtain burning voltage output.Output voltage U _oSampling value V _FBWith the chip internal reference voltage V _REFDifference relatively obtains V through the PI demodulator _m(being produced by pin COMP), the COMP pin of three chips is parallel to a bit, shares an external circuits again, constitutes a voltage error amplifying element, guarantees the voltage error value of magnification V of every phase _mIdentical, thus reach desirable control effect, with output over-voltage sampled voltage V _OVPReceive the OVP mouth of three chips respectively, when this voltage greater than chip in given magnitude of voltage, the output duty cycle signal is zero, output voltage reduces, and plays the effect of overvoltage protection.To export under voltage sampled voltage V _BOPReceive the BOP mouth of three chips respectively, before this magnitude of voltage is less than the chip set point, block duty cycle signals, to a certain degree play under voltage protection and when rectifier starts, play the soft start effect.The three-phase current sampled signal is respectively through resistance R _SFM(M=1,2,3) receives chip I SNS pin, wherein R _SFMAll get 100 Europe, C _SFN(N=1,2,3) is all 100nF, C _Z, C _S, R _GmExternal PI regulates parameter for chip, regulates output in order to obtain identical PI, and three chips use same external capacitor resistance circuit, choose C _Z=0.47uF, C _S=10nF, R _Gm=4.7K, for obtaining the better dynamic response results, but each parameter size of appropriate change, the pwm signal that chip is produced drives chip M57959L through IGBT and amplifies rear drive IGBT pipe separately at last.Switching tube drive circuit 9 is made of M57959L chip and peripheral circuit thereof.

Current detecting unit 7 comprises three input current sample circuits, and each input current sample circuit is connected and composed successively by current sensor and current signal absolute value amplifying circuit.Three current sensor sampling input current i _j(j=a, b, c), transducer conversion coefficient are 0.1, i.e. u _j=0.1i _j(j=a, b, c, u _jBe the current sensor output voltage values).After obtaining the voltage signal of alternation, behind absolute value amplifying circuit as shown in Figure 2, obtain suitable negative voltage signal respectively and receive corresponding control chip IR1153S current sampling signal input, form electric current loop.In each cycle, obtain corresponding duty cycle signals, again the service time of control IGBT pipe after driving amplifying circuit, make this phase current reach predetermined value.Control at last makes input current follow input voltage to become sinusoidal variations, and the phase angle is zero, therefore realized the three-phase high power factor rectified action.

U _a, U _b, U _cBe three-phase input voltage, its effective value is 240V, U _oBe output voltage, its value is 750V, and the converter power output is 6KW.By changing opening and turn-offing of switching tube, when A, B or C phase input voltage were in positive half period, switching tube was open-minded, and the inductive current forward constantly increases.And switching tube is when turn-offing, the last brachium pontis diode D of the rectifier bridge of corresponding phase _IpElectrochemical capacitor C is given in (i=a, b, c) conducting _pReturn the load power supply in the time of charging, the inductive current forward constantly descends.When A, B or C phase phase input voltage were in negative half-cycle, switching tube was open-minded on the contrary, and inductive current oppositely constantly increases, and switching tube is when turn-offing, the following brachium pontis diode D of the rectifier bridge of corresponding phase _InCapacitor C is given in (i=a, b, c) conducting _nIn charging time, is powering load also.

In order to reduce the power consumption of whole divider resistance, and have enough input bias currents to guarantee the output of error amplifier, compromise choose voltage-dividing detection circuit 6 output voltage sampling resistor R _FB1=2M Europe.According to required output voltage U _oBig I calculates R _FB2Size, its computing formula is:

${\mathrm{<figure-callout\; id="2"\; label="R\; FB"\; filenames="130411142030.png,130411142039.png"\; state="\{\{state\}\}">R</figure-callout>}}_{\mathrm{FB}}=\frac{V_{\mathrm{REF}}{R}_{\mathrm{FB}1}}{({0.5U}_o-V_{\mathrm{REF}})}---\left(1\right)$

Wherein, V _REFBe the reference voltage that chip internal produces, its value calculates R for 5V _FB2Be 27K Europe.Output under voltage sampling resistor is got R _BOP1Two 2.4M Europe resistance series connection are adopted, R in=4.8M Europe _BOP2Determined by following formula:

${\mathrm{<figure-callout\; id="2"\; label="R\; BOP"\; filenames="130411142030.png,130411142039.png"\; state="\{\{state\}\}">R</figure-callout>}}_{\mathrm{BOP}}=\frac{V_{\mathrm{BOP}\left(\mathrm{HI}\right)}{R}_{\mathrm{BOP}1}}{(\sqrt{2}{V}_{\mathrm{AC},\mathrm{ON}}-V_{\mathrm{BOP}\left(\mathrm{HI}\right)}-V_{\mathrm{BRIDGE}})}---\left(2\right)$

Wherein, V _BOP(HI)Be the reference voltage that chip internal produces, its value is 1.56V, V _BRIDGEBe 2V, V _{AC, ON}Be input voltage effective value, R _BOP2Can choose the resistance that resistance is 35K Europe.Choose output over-voltage feedback resistance R _OVP1=2M Europe, R _OVP2Determined by following formula:

${\mathrm{<figure-callout\; id="2"\; label="R\; OVP"\; filenames="130411142030.png,130411142039.png"\; state="\{\{state\}\}">R</figure-callout>}}_{\mathrm{OVP}}=\frac{V_{\mathrm{OVP}}{R}_{\mathrm{OVP}1}}{({0.5U}_O-V_{\mathrm{OVP}})}---\left(3\right)$

Generally get overvoltage V _OVP=1.06V _REF, therefore calculate resistance R _OVP2=29K Europe.

After being in series, various voltage sample resistance are connected in parallel on brachium pontis electrochemical capacitor C _pTwo ends, and draw lead to monocycle control chip IR1153S from junction separately.

It is u that current sensor sampling input current signal obtains output voltage signal _j(j=a, b, c) is through absolute value circuit A ₁, A ₂Obtain U _Oj(j=a, b, c), wherein U _Oj=| u _j|, R in the circuit ₁Getting resistance is 3K Europe, R ₂, R ₃, R ₄, R ₅, R ₇Usually getting resistance is 10K Europe, D ₁D ₂Be diode IN4148, again by operational amplifier A ₃With U _OjAmplify that (multiplication factor is by resistance R ₇, R ₈Determine), obtain V _Ij=-(R ₈/ R ₇) U _Oj(j=a, b, c), R ₇, R ₈Resistance size need the size of current sensor output signal when input current reaches maximum in the circuit design, and be controlled the chip input voltage amplitude limitation and decide choosing of parameter, V _Ij(j=a, b, c) must (between the 0.68V～0V), for satisfying this requirement, get R among the design ₈/ R ₇=1/3.

The principle of monocycle control of the present invention, namely the duty ratio of real-time control switch makes to reach baseline signal value in each switch periods inner control amount, finally can realize the distortion of unity power factor and low current.

To simplify the analysis, existing is example with the A circuitry phase.S _aDuring conducting, inductance L _aBoth end voltage is line voltage U _aS _aDuring shutoff, if line voltage is in positive half cycle, inductance L _aBoth end voltage is U _a-UP; If line voltage is in negative half period, inductance L _aBoth end voltage is U _a-U _NBy weber balance can get:

U _a=(1-D _a)U _p （U _a>0） （4）

-U _a=(1-D _a)U _N （U _a<0） （5）

D _aBe duty ratio size in the switch periods, when circuit reaches stable state, the electric voltage equalization on two electric capacity, and be half of output voltage, i.e. U _P=U _N=0.5U _o, therefore:

|U _a|=0.5(1-D _a)U _o （6）

As shown in Figure 3, output voltage U _oSampling value V _FBWith the chip internal reference voltage V _REFDifference relatively obtains V through the PI demodulator _m(being produced by pin COMP), the clock cycle of chip is 22KH _Z, 5 analyze by reference to the accompanying drawings, when each switch periods begins, by internal clock signal Clock1 inner rest-set flip-flop is carried out set, the power switch pipe conducting.Current sampling signal is by being connected to comparator input terminal separately, the reset output of integrator of another input termination of comparator, and the time of integration is identical with switch periods, and the integrator output voltage value that resets is V _m(1-D _a).When current sampling data reaches when resetting the integrator output voltage value, trigger reset that can it is corresponding, corresponding switching tube turn-offs, treat one-period finish before by the Clock2 signal to the integrator zero clearing, for following one-period prepares, and can obtain duty cycle of switching:

D _a=1-V _ia/V _m （7）

Bringing formula (7) into formula (6) can get:

U _a=U _oV _ia/2V _m （8）

Under the stable state, U _o, V _mBe steady state value, V _Ia=k.i _a, wherein, k is the current sample coefficient, the selected back of current sample parameter k is constant, note R _e=k.U _o/ 2V _m, can get:

U _a=R _e.i _a （9）

Other two-phases are also like this, and therefore for the three-phase input, each single-phase output loading can equivalence be a pure resistor load, and equal and opposite in direction, that is:

U _a=R _e×i _a,U _b=R _e×i _b,U _c=R _e×i _c （10）

Following formula shows that this control scheme can make the input impedance of each phase of converter be real impedance, makes each phase input current waveform follow its phase voltage and becomes sinusoidal variations, and the phase angle is zero, has realized unity power factor.

Below schematically the invention and execution mode thereof are described, this description does not have restricted, and shown in the accompanying drawing also is one of execution mode of the invention, and practical structure is not limited thereto.So, if those of ordinary skill in the art is enlightened by it, under the situation that does not break away from this creation aim, without the creationary frame mode similar to this technical scheme and the embodiment of designing, all should belong to the protection range of this patent.

Claims (7)

1. the control circuit of a three-phase high power factor rectifier, comprise input high-frequency filter circuit (1), three-phase input inductance (2) and rectified three-phase circuit (3), it is characterized in that, also comprise switching tube power circuit (4), output rectifier and filter (5), voltage-dividing detection circuit (6), input current detecting unit (7), single cycle controller (8) and switching tube drive circuit (9);

Described input high-frequency filter circuit (1) comprises three high-frequency filter capacitor C that parameter is identical _a, C _bAnd C _c, C _a, C _bAnd C _cAn end respectively correspondence be connected to electrical network A phase voltage input, electrical network B phase voltage input and electrical network C phase voltage input, the other end is connected to the neutral line of three-phase and four-line electricity, neutral earthing simultaneously;

Described three-phase input inductance (2) comprises three high frequency BOOST inductance L that parameter is identical _a, L _bAnd L _c

Described rectified three-phase circuit (3) comprises three brachium pontis, i.e. A phase brachium pontis, B phase brachium pontis and C brachium pontis mutually;

Described switching tube power circuit (4) comprises three bidirectional switch pipe S _a, S _bAnd S _cElectrical network A phase input voltage is through inductance L _aBe connected to A phase brachium pontis mid point A and bidirectional switch pipe S _aAn end, electrical network B phase input voltage is through inductance L _bBe connected to B phase brachium pontis mid point B and bidirectional switch pipe S _bAn end, electrical network C phase input voltage is through inductance L _cBe connected to C phase brachium pontis mid point C and bidirectional switch pipe S _cAn end; Described bidirectional switch pipe S _a, S _bAnd S _cThe other end insert network neutral line simultaneously and driven by switching tube drive circuit (9);

Described rectified three-phase circuit (3), output rectifier and filter (5) and voltage-dividing detection circuit (6) are connected successively; Described single cycle controller (8) is connected with voltage-dividing detection circuit (6), input current detecting unit (7) and switching tube drive circuit (9) respectively; Described input current detecting unit (7) detects the inductance L of flowing through respectively _a, L _bAnd L _cAfter electric current.

2. the control circuit of a kind of three-phase high power factor rectifier according to claim 1 is characterized in that, described bidirectional switch pipe S _a, S _bAnd S _cEach is by four rectifier diode D _I1, D _I2, D _I3, D _I4With an IGBT pipe K _iForm D _I2Negative electrode and D _I1Anode links to each other, D _I1Negative electrode be connected to inductance one end in the i circuitry phase, D _I4Negative electrode and D _I3Anode links to each other, D _I3Negative electrode be connected to center line, D _I1Negative electrode, D _I3Negative electrode and the collector electrode of IGBT link together D _I2Anode, D _I4Anode and the emitter of IGBT link together, wherein, i=a, b, c, the grid of IGBT pipe is connected with switching tube drive circuit (9).

3. the control circuit of a kind of three-phase high power factor rectifier according to claim 1 is characterized in that, described rectified three-phase circuit (3) comprises six fast recovery diode D _Ap, D _Bp, D _Cp, D _An, D _BnAnd D _Cn, D _ApAnode and D _AnNegative electrode be connected to form A phase brachium pontis, D _BpAnode and D _BnNegative electrode be connected to form B phase brachium pontis, D _CpAnode and D _CnNegative electrode be connected to form C phase brachium pontis, D _Ap, D _Bp, D _CpNegative electrode link together D simultaneously _An, D _BnAnd D _CnAnode link together.

4. according to the control circuit of claim 1 or 2 or 3 described a kind of three-phase high power factor rectifiers, it is characterized in that described output rectifier and filter (5) comprises two output electrochemical capacitor C _p, C _n, described output electrochemical capacitor C _pNegative pole and described output electrochemical capacitor C _nPositive pole link to each other, tie point connects to neutral, described output electrochemical capacitor C _pPositive pole connect D _Ap, D _BpAnd D _CpNegative electrode, described output electrochemical capacitor C _nNegative pole connect D _An, D _BnAnd D _CnAnode.

5. the control circuit of a kind of three-phase high power factor rectifier according to claim 4 is characterized in that, described voltage-dividing detection circuit (6) comprises output voltage sampling resistor R _FB1, R _FB2, output under voltage sampling resistor R _BOP1, R _BOP2With output over-voltage sampling resistor R _OVP1, R _OVP2, each is organized and is connected in parallel on output capacitance C after voltage sample resistance is in series _pTwo ends, and draw lead from the junction of each group voltage sample resistance series connection and insert described single cycle controller (8) respectively.

6. the control circuit of a kind of three-phase high power factor rectifier according to claim 5 is characterized in that, described single cycle controller (8) comprises three monocycle Single-phase PFC control chip IR1153S, output voltage U _oSampling value V _FBBe connected to the VFB pin of three chip I R1153S respectively, the COMP pin of three chips is parallel to a bit, shares an external circuits again, constitutes a voltage error amplifying element, output over-voltage sampled voltage V _OVPReceive the OVP mouth of three chips respectively, output under voltage sampled voltage V _BOPReceive the BOP mouth of three chips respectively; Described switching tube drive circuit (9) is made of M57959L chip and peripheral circuit thereof.

7. the control circuit of a kind of three-phase high power factor rectifier according to claim 6, it is characterized in that, described input current detecting unit (7) comprises three input current sample circuits, and each input current sample circuit is connected and composed successively by current sensor and current signal absolute value amplifying circuit; The input of described three current sensors three road inductive current values of sampling respectively, the output signal of described inductive current sampling is connected with single cycle controller (8) through the output of absolute value amplifying circuit.

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