CN104143932A - Dual-vector model prediction direct power control method and device - Google Patents

Abstract

The invention discloses a dual-vector model prediction direct power control method. The method comprises the steps of obtaining a power grid side voltage signal, a power grid side current signal and a power grid side voltage delay signal on static two-phase coordinates; obtaining the active power instantaneous value and the novel reactive power instantaneous value of the current moment through analytic calculation, and predicting the active power instantaneous value and the novel reactive power instantaneous value of the next moment; obtaining the active power set value and the novel reactive power set value through calculation; obtaining the optimal voltage vector through an evaluation function; obtaining the action time of an effective vector through calculation; obtaining a corresponding driving signal through a dual vector formed by synthesis in a cycle to drive a switching tube. The invention further discloses a dual-vector model prediction direct power control device. The dual-vector model prediction direct power control method and device have the advantages of being free of transformation of rotational coordinates, small in calculation amount, easy to realize, good in robustness and the like.

Description

Two vector model prediction direct Power Control methods and device

Technical field

The present invention relates to electric and electronic technical field, refer to especially a kind of pair of vector model prediction direct Power Control method and device.

Background technology

Model prediction direct Power Control is without Rotating Transition of Coordinate, has that algorithm is simple, dynamic response is fast, power pulsations is little and the advantage such as robustness is good and being widely accepted.And the straight power of model prediction is controlled at that desired electrical is off the net comparatively deep research, but in actual electric network because the factors such as laod unbalance and electric network fault all can cause that line voltage is asymmetric; If continue to use the method for conventional model prediction direct Power Control, can make current on line side occur a large amount of harmonic waves, there are two frequency multiplication fluctuations etc. in DC bus-bar voltage and net side power, has a strong impact on the performance of system; Yet about model prediction direct Power Control, be not applied to the relevant report of unbalanced source voltage.Document < < Modeling and analysis of instantaneous active and reactive power for pwm ac/dc converter under generalized unbalanced network > > is applied to VOC framework novel reactive power, but it still needs line voltage and power network current to carry out positive-negative sequence decomposition; Document < < Control of three-phase PWM rectifier in stationary frame under unbalanced input voltage > > makes certain improvements, do not need line voltage and power network current to carry out positive-negative sequence decomposition, but it needs a ratio resonator (PR) to control electric current.

Summary of the invention

In view of this, the object of the invention is to propose a kind of pair of vector model prediction direct Power Control method and device, this improved pair of vector model prediction direct Power Control both can have been moved under desirable electrical network simultaneously also can well operation in unbalanced source voltage situation.

Based on provided by the invention pair of vector model prediction direct Power Control method of above-mentioned purpose, comprising:

Grid side voltage and current is obtained to grid side voltage signal and the grid side current signal in static two phase coordinates by 3/2 conversion; Further by 1/4 cycle delay function, obtain grid side voltage delay signal;

According to the grid side voltage signal in static two phase coordinates obtaining and grid side current signal and grid side voltage delay signal, analytical Calculation obtains current time active power instantaneous value and novel reactive power instantaneous value; And predict next active power instantaneous value and novel reactive power instantaneous value constantly;

Calculating and controlling target is to eliminate to gain merit to be respectively traditional active power set-point and reactive power set-point with novel two idle frequency multiplication fluctuations and active power set-point and the novel reactive power set-point of current on line side sine;

By next active power instantaneous value and novel reactive power instantaneous value and the active power set-point calculating and reactive power set-point constantly, through valuation functions, obtain optimum voltage vector, this voltage vector is the effective vector in two vectors;

Take active power and novel reactive power pulsation minimum action time that calculates effective vector as controlling target, all the other times are zero vector action time; By two vectors synthetic in one-period, obtained driving accordingly signal to drive switching tube.

In some embodiments, described grid side voltage and current is obtained to grid side voltage signal and the grid side current signal in static two phase coordinates by 3/2 conversion; Further by 1/4 cycle delay function, obtain also comprising before the step of grid side voltage delay signal:

Utilize voltage LEM transducer and electric current LEM sensor sample rectifier DC side voltage, grid side voltage and power network current;

Described grid side voltage and current is obtained to grid side voltage signal and the grid side current signal in static two phase coordinates by 3/2 conversion; Further by 1/4 cycle delay function, obtain in the step of grid side voltage delay signal:

Grid side voltage and current is obtained to grid side voltage signal and the grid side current signal in static two phase coordinates by 3/2 conversion, and expression is:

$\left[\begin{array}{c}{e}_{\mathrm{\&alpha;}}\\ e_{\mathrm{\&beta;}}\end{array}\right]=\frac{2}{3}\left[\begin{array}{ccc}1& -\frac{1}{2}& -\frac{1}{2}\\ 0& \frac{\sqrt{3}}{2}& -\frac{\sqrt{3}}{2}\end{array}\right]\left[\begin{array}{c}{e}_a\\ e_b\\ e_c\end{array}\right],$ Wherein, e _α, e _βbe respectively the grid side voltage signal in static α phase coordinates and β phase coordinates;

$\left[\begin{array}{c}{i}_{\mathrm{\&alpha;}}\\ i_{\mathrm{\&beta;}}\end{array}\right]=\frac{2}{3}\left[\begin{array}{ccc}1& -\frac{1}{2}& -\frac{1}{2}\\ 0& \frac{\sqrt{3}}{2}& -\frac{\sqrt{3}}{2}\end{array}\right]\left[\begin{array}{c}{i}_a\\ i_b\\ i_c\end{array}\right],$ Wherein, i _α, i _βbe respectively the grid side current signal in static α phase coordinates and β phase coordinates;

Further by postponing for 1/4 cycle, obtain grid side voltage delay signal, expression is:

$e_{\mathrm{\&alpha;}}^{\&prime;}\left(t\right)=e_{\mathrm{\&alpha;}}(t-\frac{T}{4})$

$e_{\mathrm{\&beta;}}^{\&prime;}\left(t\right)=e_{\mathrm{\&beta;}}(t-\frac{T}{4}),$

Wherein T is a power frequency period, is 0.02s for 50Hz electrical network.

In some embodiments, the grid side voltage signal in static two phase coordinates that described basis obtains and grid side current signal and grid side voltage delay signal, analytical Calculation obtains current time active power instantaneous value and novel reactive power instantaneous value; And predict that in the active power instantaneous value in next moment and the step of novel reactive power instantaneous value, the expression formula of active power instantaneous value and traditional reactive power instantaneous value is:

$\left[\begin{array}{c}P\\ Q\end{array}\right]=\frac{3}{2}\left[\begin{array}{c}{i}_{\mathrm{\&alpha;}}{e}_{\mathrm{\&alpha;}}+i_{\mathrm{\&beta;}}{e}_{\mathrm{\&beta;}}\\ i_{\mathrm{\&alpha;}}{e}_{\mathrm{\&alpha;}}-i_{\mathrm{\&beta;}}{e}_{\mathrm{\&alpha;}}\end{array}\right],$

The expression formula of novel reactive power instantaneous value is:

$Q^{\mathrm{nov}}=\frac{3}{2}(i_{\mathrm{\&alpha;}}{e^{\&prime;}}_{\mathrm{\&alpha;}}+i_{\mathrm{\&beta;}}{e^{\&prime;}}_{\mathrm{\&beta;}}).$

In some embodiments, described in, calculate and control target and for eliminating the active power set-point of meritorious and novel two idle frequencys multiplication fluctuations and current on line side sine and novel reactive power set-point, be respectively in the step of traditional active power set-point and reactive power set-point:

Active power set-point is that the difference of given direct voltage and PWM rectifier DC side voltage is passed through pi regulator and is multiplied by PWM rectifier DC side voltage, and expression is:

$P^{\mathrm{ref}}=(k_p+\frac{k_i}{s})(U_{\mathrm{dc}}^{\mathrm{ref}}-U_{\mathrm{dc}})\&times;U_{\mathrm{dc}};$

Reactive power set-point Q ^refbe made as zero.

In some embodiments, described valuation functions is:

g＝|P ^ref-P ^k+1|+|Q ^ref-Q ^nov,k+1|，

Wherein: $P^{k+1}=P^k+\frac{{3T}_s}{2L}({\left|e_{\mathrm{\&alpha;\&beta;}}^k\right|}^2-\mathrm{Re}\left(v_{\mathrm{\&alpha;\&beta;}}^{k*}{e}_{\mathrm{\&alpha;\&beta;}}^k\right))-\frac{{\mathrm{RT}}_s}{L}{P}^k-{\mathrm{\&omega;T}}_s{Q}^{\mathrm{nov},k},$

$Q^{\mathrm{nov},k+1}=Q^{\mathrm{nov},k}+\frac{{3T}_s}{2L}(\mathrm{Re}\left(e_{\mathrm{\&alpha;\&beta;}}^{k*}{e}_{\mathrm{\&alpha;\&beta;}}^{k^{\&prime;}}\right)-\mathrm{Re}\left(v_{\mathrm{\&alpha;\&beta;}}^{k*}{e}_{\mathrm{\&alpha;\&beta;}}^{k^{\&prime;}}\right))-\frac{{\mathrm{RT}}_s}{L}{Q}^{\mathrm{nov},k}+{\mathrm{\&omega;T}}_s{P}^k,$

T wherein _srepresent control cycle, for each voltage vector in two level converters by two formulas above, can obtain corresponding next (k+1 constantly) active power instantaneous value P constantly ^k+1with next moment (k+1 constantly) novel reactive power instantaneous value Q ^{nov, k+1}, further substitution valuation functions can obtain a valuation functions value; By all voltage vectors are carried out to above treatment step, finally obtain making the voltage vector of valuation functions minimum to be optimal voltage vector v _opt.

In some embodiments, active power and the novel reactive power pulsation of take is minimum to be calculated as controlling target in the step of action time of effective vector, and the expression formula of described effective vector action time is:

$\begin{array}{c}{t}_{\mathrm{op}}=\frac{2(P^{\mathrm{ref}}-P^{k+1})(s_1-s_2)+2(Q^{\mathrm{ref}}-Q^{\mathrm{nov},k+1})(s_{11}-s_{22})}{2(s_1^2+s_2^2)+s_{11}^2+s_{22}^2-3(s_1{s}_2+s_{11}{s}_{22})}\\ \frac{T_s[s_2(s_2-s_1)+s_{22}(s_{22}-s_{11})]}{2(s_1^2+s_2^2)+s_{11}^2+s_{22}^2-3(s_1{s}_2+s_{11}{s}_{22})}\end{array},$

Wherein, s ₁and s ₂the rate of change of the active power of effective vector zero vector while representing any time (k is constantly), s ₁₁and s ₂₂the rate of change of the novel reactive power of effective vector zero vector while representing any time (k is constantly), is expressed as follows respectively:

$\left\{\begin{array}{c}{s}_1=\frac{3}{2L}[{\left|e_{\mathrm{\&alpha;\&beta;}}^k\right|}^2-\mathrm{Re}\left(v_{\mathrm{\&alpha;\&beta;}}^{k*}{e}_{\mathrm{\&alpha;\&beta;}}^k\right)]-\frac{R}{L}{P}^k-{\mathrm{\&omega;Q}}^{\mathrm{nov},k}\\ s_2=\frac{3}{2L}{\left|e_{\mathrm{\&alpha;\&beta;}}^k\right|}^2-\frac{R}{L}{P}^k-{\mathrm{\&omega;Q}}^{\mathrm{nov},k}\end{array}\right.,$

$\left\{\begin{array}{c}{s}_{11}=\frac{3}{3L}(\mathrm{Re}\left(e_{\mathrm{\&alpha;\&beta;}}^{k*}{e}_{\mathrm{\&alpha;\&beta;}}^{k^{\&prime;}}\right)-\mathrm{Re}\left(v_{\mathrm{\&alpha;\&beta;}}^{k*}{e}_{\mathrm{\&alpha;\&beta;}}^{k^{\&prime;}}\right))-\frac{R}{L}{Q}^{\mathrm{nov},k}+{\mathrm{\&omega;P}}^k\\ s_{22}=\frac{3}{2L}(\mathrm{Re}\left(e_{\mathrm{\&alpha;\&beta;}}^{k*}{e}_{\mathrm{\&alpha;\&beta;}}^{k^{\&prime;}}\right)-\frac{R}{L}{Q}^{\mathrm{nov},k}+{\mathrm{\&omega;P}}^k\end{array}\right.,$

V wherein _optit is the optimal voltage vector of choosing by valuation functions any time (k constantly); In next control cycle, optimal voltage vector first action time be t _opt, all the other times are distributed to zero vector effect, send respectively the switching tube driving pulse of corresponding voltage vector within time separately.

Another aspect of the present invention also provides a kind of two vector model prediction direct Power Control devices that adopt described two vector model prediction direct Power Control methods, comprises the three-phase voltage source, three-phase filter inductance, rectifier bridge main circuit, DC bus capacitor, the load that connect successively; And, from three-phase voltage source output terminal and three-phase filter inductance output, carry out respectively the electric current and voltage sample circuit of voltage, current sample, the electric current and voltage data of electric current and voltage sample circuit are carried out to the dsp controller of s operation control, drive circuit;

Wherein, described electric current and voltage sample circuit utilizes voltage hall sensor and current Hall transducer to gather respectively three-phase net side alternating voltage, alternating current and rectifier DC side voltage, enters dsp controller and be converted to digital signal after signal conditioning circuit; Dsp controller completes the computing of the two vector model prediction direct Power Control methods as described in claim 1-6 any one, exports six road pwm pulses, then after overdrive circuit, obtains the final driving signal of six switching tubes of rectifier.

As can be seen from above, the two vector model prediction direct Power Control methods of three-phase AC/DC converter provided by the invention and device, the method being intended to by existing AC/DC converter model prediction power is controlled is improved, a kind of improved pair of novel vector model prediction direct Power Control proposed, thereby can strengthen the adaptability to unbalanced source voltage, comprise the two frequency multiplication fluctuations of eliminating net side active power, eliminate two frequency multiplication fluctuations of novel reactive power, the pulsation of elimination VD, reduce the harmonic wave of current on line side, reach with balance electrical network under similar operational effect.The two vector model prediction of the improvement direct Power Control that the present invention proposes is applied to novel Reactive power definition in model prediction framework, and do not need line voltage and power network current to carry out positive-negative sequence decomposition, do not need rated output offset simultaneously, under rest frame, realize completely, have that algorithm is simple, dynamic response is fast, to system parameter disturbance strong robustness, the advantage such as easy to implement; In order to obtain better control effect, the present invention in unbalanced source voltage situation, has two voltage vectors to control system this application of policies of two vectors in a control cycle; And emulation and experimental verification validity and the practicality of the two vector models prediction of improvement proposed by the invention direct Power Control.

Accompanying drawing explanation

Fig. 1 is the schematic flow sheet that two vector models of three-phase voltage type AC/DC converter under the novel Reactive power definition based on unbalanced electric grid voltage provided by the invention are predicted an embodiment of direct Power Control methods;

Fig. 2 is the structural representation that two vector models of three-phase voltage type AC/DC converter under the novel Reactive power definition based on unbalanced electric grid voltage provided by the invention are predicted an embodiment of direct Power Control devices;

Fig. 3 is the structural representation that two vector models of three-phase voltage type AC/DC converter under the novel Reactive power definition based on unbalanced electric grid voltage provided by the invention are predicted another embodiment of direct Power Control devices;

Fig. 4 is active power, the traditional reactive power of conventional model prediction direct Power Control under unbalanced source voltage, novel reactive power, the simulation result schematic diagram of voltage on line side, electric current;

Fig. 5 is two vector model prediction direct Power Control methods and active power, the traditional reactive power of device under unbalanced source voltage that the present invention proposes, novel reactive power, the simulation result schematic diagram of voltage on line side, electric current;

Fig. 6 adopts conventional model prediction direct Power Control by line voltage, to equilibrate to the active power in uneven situation, novel reactive power, the experimental result schematic diagram of voltage on line side, electric current;

Fig. 7 is that two vector model prediction direct Power Control methods and the device that the present invention proposes equilibrates to the active power in uneven situation by line voltage, novel reactive power, the experimental result schematic diagram of voltage on line side, electric current.

Embodiment

For making the object, technical solutions and advantages of the present invention clearer, below in conjunction with specific embodiment, and with reference to accompanying drawing, the present invention is described in more detail.

The two vector models that are three-phase voltage type AC/DC converter under the novel Reactive power definition based on unbalanced electric grid voltage provided by the invention with reference to accompanying drawing 1 are predicted the schematic flow sheet of an embodiment of direct Power Control methods.

Described pair of vector model prediction direct Power Control method, comprising:

Step 101: grid side voltage and grid side electric current are obtained to the grid side voltage signal e on static two-phase α β coordinate by 3/2 conversion _α, e _βand grid side current signal i _α, i _β; Further by 1/4 cycle delay function, obtain grid side voltage delay signal e ' _α, e ' _β;

Step 102: the grid side voltage signal in static two phase coordinates obtaining according to step 101 and grid side current signal and grid side voltage delay signal, analytical Calculation obtains current time active power instantaneous value and novel reactive power instantaneous value; And predict next active power instantaneous value and novel reactive power instantaneous value constantly;

Step 103: take and control target as eliminating meritorious and novel idle two frequency multiplication fluctuations and current on line side sine, through active power set-point and the novel reactive power set-point calculating, be respectively traditional active power set-point and reactive power set-point, i.e. P ^refand Q ^ref; Wherein, traditional active power set-point P ^reffor the difference of given direct voltage and PWM rectifier DC side voltage is passed through pi regulator and is multiplied by DC voltage; Reactive power set-point Q ^refgenerally be made as zero;

Step 104: by next active power instantaneous value and novel reactive power instantaneous value and the active power set-point calculating and reactive power set-point constantly, through valuation functions, obtain optimum voltage vector, this voltage vector is the effective vector in two vectors;

Step 105: take active power and novel reactive power pulsation minimum action time that calculates effective vector as controlling target, all the other times are zero vector action time; By two vectors synthetic in one-period, obtained driving accordingly signal to drive switching tube.

Optionally, described grid side voltage and current is obtained to grid side voltage signal and the grid side current signal in static two phase coordinates by 3/2 conversion; Further by 1/4 cycle delay function, obtain also comprising before the step 101 of grid side voltage delay signal:

Utilize voltage LEM transducer (voltage hall sensor) and electric current LEM transducer (current Hall transducer) sampling rectifier DC side voltage, grid side voltage and power network current;

Described grid side voltage and current is obtained to grid side voltage signal and the grid side current signal in static two phase coordinates by 3/2 conversion; Further by 1/4 cycle delay function, obtain in the step 101 of grid side voltage delay signal:

Grid side voltage and current is obtained to grid side voltage signal and the grid side current signal on static two-phase α β coordinate by 3/2 conversion, and expression is:

$\left[\begin{array}{c}{e}_{\mathrm{\&alpha;}}\\ e_{\mathrm{\&beta;}}\end{array}\right]=\frac{2}{3}\left[\begin{array}{ccc}1& -\frac{1}{2}& -\frac{1}{2}\\ 0& \frac{\sqrt{3}}{2}& -\frac{\sqrt{3}}{2}\end{array}\right]\left[\begin{array}{c}{e}_a\\ e_b\\ e_c\end{array}\right],$ Wherein, e _α, e _βbe respectively the grid side voltage signal in static α phase coordinates and β phase coordinates, e _a, e _b, e _cbe respectively three-phase electricity voltage on line side;

$\left[\begin{array}{c}{i}_{\mathrm{\&alpha;}}\\ i_{\mathrm{\&beta;}}\end{array}\right]=\frac{2}{3}\left[\begin{array}{ccc}1& -\frac{1}{2}& -\frac{1}{2}\\ 0& \frac{\sqrt{3}}{2}& -\frac{\sqrt{3}}{2}\end{array}\right]\left[\begin{array}{c}{i}_a\\ i_b\\ i_c\end{array}\right],$ Wherein, i _α, i _βbe respectively the grid side current signal in static α phase coordinates and β phase coordinates, i _a, i _b, i _cbe respectively three-phase electricity current on line side;

Further by postponing for 1/4 cycle, obtain grid side voltage delay signal, expression is:

$e_{\mathrm{\&alpha;}}^{\&prime;}\left(t\right)=e_{\mathrm{\&alpha;}}(t-\frac{T}{4})$

$e_{\mathrm{\&beta;}}^{\&prime;}\left(t\right)=e_{\mathrm{\&beta;}}(t-\frac{T}{4}),$

Wherein T is a power frequency period, is 0.02s for 50Hz electrical network.

Preferably, the grid side voltage signal in static two phase coordinates that described basis obtains and grid side current signal and grid side voltage delay signal, analytical Calculation obtains current time active power instantaneous value and novel reactive power instantaneous value; And predict that in the active power instantaneous value in next moment and the step 102 of novel reactive power instantaneous value, the expression formula of active power instantaneous value and traditional reactive power instantaneous value is:

$\left[\begin{array}{c}P\\ Q\end{array}\right]=\frac{3}{2}\left[\begin{array}{c}{i}_{\mathrm{\&alpha;}}{e}_{\mathrm{\&alpha;}}+i_{\mathrm{\&beta;}}{e}_{\mathrm{\&beta;}}\\ i_{\mathrm{\&alpha;}}{e}_{\mathrm{\&alpha;}}-i_{\mathrm{\&beta;}}{e}_{\mathrm{\&alpha;}}\end{array}\right],$

The expression formula of novel reactive power instantaneous value is:

$Q^{\mathrm{nov}}=\frac{3}{2}(i_{\mathrm{\&alpha;}}{e^{\&prime;}}_{\mathrm{\&alpha;}}+i_{\mathrm{\&beta;}}{e^{\&prime;}}_{\mathrm{\&beta;}}).$

Further, described in, calculate and control target and for eliminating the active power set-point of meritorious and novel two idle frequencys multiplication fluctuations and current on line side sine and novel reactive power set-point, be respectively in the step 103 of traditional active power set-point and reactive power set-point:

Active power set-point is that the difference of given direct voltage and PWM rectifier DC side voltage is passed through pi regulator and is multiplied by PWM rectifier DC side voltage, and expression is:

$P^{\mathrm{ref}}=(k_p+\frac{k_i}{s})(U_{\mathrm{dc}}^{\mathrm{ref}}-U_{\mathrm{dc}})\&times;U_{\mathrm{dc}};$

Reactive power set-point Q ^refbe made as zero.

Further, the expression formula of described valuation functions is:

g＝|P ^ref-P ^k+1|+|Q ^ref-Q ^nov,k+1|，

Wherein: next of the prediction constantly expression formula of the active power instantaneous value of (k+1 is constantly) is:

$P^{k+1}=P^k+\frac{{3T}_s}{2L}({\left|e_{\mathrm{\&alpha;\&beta;}}^k\right|}^2-\mathrm{Re}\left(v_{\mathrm{\&alpha;\&beta;}}^{k*}{e}_{\mathrm{\&alpha;\&beta;}}^k\right))-\frac{{\mathrm{RT}}_s}{L}{P}^k-{\mathrm{\&omega;T}}_s{Q}^{\mathrm{nov},k},$

Next of the prediction constantly expression formula of the novel reactive power instantaneous value of (k+1 is constantly) is:

$Q^{\mathrm{nov},k+1}=Q^{\mathrm{nov},k}+\frac{{3T}_s}{2L}(\mathrm{Re}\left(e_{\mathrm{\&alpha;\&beta;}}^{k*}{e}_{\mathrm{\&alpha;\&beta;}}^{k^{\&prime;}}\right)-\mathrm{Re}\left(v_{\mathrm{\&alpha;\&beta;}}^{k*}{e}_{\mathrm{\&alpha;\&beta;}}^{k^{\&prime;}}\right))-\frac{{\mathrm{RT}}_s}{L}{Q}^{\mathrm{nov},k}+{\mathrm{\&omega;T}}_s{P}^k,$

T wherein _srepresent control cycle.For each voltage vector in two level converters by two formulas above, can obtain corresponding next (k+1 constantly) active power instantaneous value P constantly ^k+1with next moment (k+1 constantly) novel reactive power instantaneous value Q ^{nov, k+1}, further substitution valuation functions can obtain a valuation functions value (g value).By all voltage vectors are carried out to above treatment step, finally obtain making the voltage vector of valuation functions minimum to be optimal voltage vector v _opt.

Preferably, active power and the novel reactive power pulsation of take is minimum to be calculated as controlling target in the step 105 of action time of effective vector, and the expression formula of described effective vector action time is:

$\begin{array}{c}{t}_{\mathrm{op}}=\frac{2(P^{\mathrm{ref}}-P^{k+1})(s_1-s_2)+2(Q^{\mathrm{ref}}-Q^{\mathrm{nov},k+1})(s_{11}-s_{22})}{2(s_1^2+s_2^2)+s_{11}^2+s_{22}^2-3(s_1{s}_2+s_{11}{s}_{22})}\\ \frac{T_s[s_2(s_2-s_1)+s_{22}(s_{22}-s_{11})]}{2(s_1^2+s_2^2)+s_{11}^2+s_{22}^2-3(s_1{s}_2+s_{11}{s}_{22})}\end{array},$

Wherein, s ₁and s ₂the rate of change of the active power of effective vector zero vector while representing any time (k is constantly), s ₁₁and s ₂₂the rate of change of the novel reactive power of effective vector zero vector while representing any time (k is constantly), is expressed as follows respectively:

$\left\{\begin{array}{c}{s}_1=\frac{3}{2L}[{\left|e_{\mathrm{\&alpha;\&beta;}}^k\right|}^2-\mathrm{Re}\left(v_{\mathrm{\&alpha;\&beta;}}^{k*}{e}_{\mathrm{\&alpha;\&beta;}}^k\right)]-\frac{R}{L}{P}^k-{\mathrm{\&omega;Q}}^{\mathrm{nov},k}\\ s_2=\frac{3}{2L}{\left|e_{\mathrm{\&alpha;\&beta;}}^k\right|}^2-\frac{R}{L}{P}^k-{\mathrm{\&omega;Q}}^{\mathrm{nov},k}\end{array}\right.,$

$\left\{\begin{array}{c}{s}_{11}=\frac{3}{3L}(\mathrm{Re}\left(e_{\mathrm{\&alpha;\&beta;}}^{k*}{e}_{\mathrm{\&alpha;\&beta;}}^{k^{\&prime;}}\right)-\mathrm{Re}\left(v_{\mathrm{\&alpha;\&beta;}}^{k*}{e}_{\mathrm{\&alpha;\&beta;}}^{k^{\&prime;}}\right))-\frac{R}{L}{Q}^{\mathrm{nov},k}+{\mathrm{\&omega;P}}^k\\ s_{22}=\frac{3}{2L}(\mathrm{Re}\left(e_{\mathrm{\&alpha;\&beta;}}^{k*}{e}_{\mathrm{\&alpha;\&beta;}}^{k^{\&prime;}}\right)-\frac{R}{L}{Q}^{\mathrm{nov},k}+{\mathrm{\&omega;P}}^k\end{array}\right.,$

V wherein _optit is the optimal voltage vector of choosing by valuation functions any time (k constantly); In next control cycle, optimal voltage vector first action time be t _opt, all the other times are distributed to zero vector effect, send respectively the switching tube driving pulse of corresponding voltage vector within time separately.

Another aspect of the present invention also provides a kind of two vector model prediction direct Power Control devices that adopt described two vector model prediction direct Power Control methods, and the two vector models that are three-phase voltage type AC/DC converter under the novel Reactive power definition based on unbalanced electric grid voltage provided by the invention with reference to accompanying drawing 2 are predicted the structural representation of an embodiment of direct Power Control devices.

Described pair of vector model prediction direct Power Control device, comprises the three-phase voltage source, three-phase filter inductance (in figure, R is equivalent resistance), rectifier bridge main circuit, DC bus capacitor, the load that connect successively; And, from three-phase voltage source output terminal and three-phase filter inductance output, carry out respectively the electric current and voltage sample circuit of voltage, current sample, the electric current and voltage data of electric current and voltage sample circuit are carried out to the dsp controller of s operation control, drive circuit;

Wherein, described electric current and voltage sample circuit utilizes voltage hall sensor and current Hall transducer to gather respectively three-phase net side alternating voltage, alternating current and rectifier DC side voltage, enters dsp controller and be converted to digital signal after signal conditioning circuit; Dsp controller completes the computing of the two vector model prediction direct Power Control methods as described in claim 1-6 any one, exports six road pwm pulses, then after overdrive circuit, obtains the final driving signal of six switching tubes of rectifier.

As can be seen from above, the two vector model prediction direct Power Control methods of three-phase AC/DC converter provided by the invention and device, the method being intended to by existing AC/DC converter model prediction power is controlled is improved, a kind of improved pair of novel vector model prediction direct Power Control proposed, thereby can strengthen the adaptability to unbalanced source voltage, comprise the two frequency multiplication fluctuations of eliminating net side active power, eliminate two frequency multiplication fluctuations of novel reactive power, the pulsation of elimination VD, reduce the harmonic wave of current on line side, reach with balance electrical network under similar operational effect.The two vector model prediction of the improvement direct Power Control that the present invention proposes is applied to novel Reactive power definition in model prediction framework, and do not need line voltage and power network current to carry out positive-negative sequence decomposition, do not need rated output offset simultaneously, under rest frame, realize completely, have that algorithm is simple, dynamic response is fast, to system parameter disturbance strong robustness, the advantage such as easy to implement; In order to obtain better control effect, the present invention in unbalanced source voltage situation, has two voltage vectors to control system this application of policies of two vectors in a control cycle; And emulation and experimental verification validity and the practicality of the two vector models prediction of improvement proposed by the invention direct Power Control.

Further, with reference to accompanying drawing 3, be the structural representation of another embodiment of the two vector models prediction direct Power Control devices of three-phase voltage type AC/DC converter under the novel Reactive power definition based on unbalanced electric grid voltage provided by the invention; Comprising the concrete calculation step of dsp controller described in Fig. 2; That is described direct Power Control method realizes successively in accordance with the following steps on the dsp controller of Fig. 2:

Step 1: three phase network side voltage and current obtains the grid side voltage signal e on static two-phase α β coordinate by 3/2 conversion _α, e _βwith grid side current signal i _α, i _β, expression is:

$\left[\begin{array}{c}{e}_{\mathrm{\&alpha;}}\\ e_{\mathrm{\&beta;}}\end{array}\right]=\frac{2}{3}\left[\begin{array}{ccc}1& -\frac{1}{2}& -\frac{1}{2}\\ 0& \frac{\sqrt{3}}{2}& -\frac{\sqrt{3}}{2}\end{array}\right]\left[\begin{array}{c}{e}_a\\ e_b\\ e_c\end{array}\right],$

$\left[\begin{array}{c}{i}_{\mathrm{\&alpha;}}\\ i_{\mathrm{\&beta;}}\end{array}\right]=\frac{2}{3}\left[\begin{array}{ccc}1& -\frac{1}{2}& -\frac{1}{2}\\ 0& \frac{\sqrt{3}}{2}& -\frac{\sqrt{3}}{2}\end{array}\right]\left[\begin{array}{c}{i}_a\\ i_b\\ i_c\end{array}\right],$

Grid side voltage signal e _α, e _βfurther by postponing for 1/4 cycle, obtain grid side voltage delay signal e ' _α, e ' _β, expression is:

$e_{\mathrm{\&alpha;}}^{\&prime;}\left(t\right)=e_{\mathrm{\&alpha;}}(t-\frac{T}{4})$

$e_{\mathrm{\&beta;}}^{\&prime;}\left(t\right)=e_{\mathrm{\&beta;}}(t-\frac{T}{4})$

Wherein T is a power frequency period, is 0.02s for 50Hz electrical network;

Step 2: the grid side voltage signal in static two phase coordinates obtaining by step 1 sampling and grid side current signal and the grid side voltage delay signal obtaining by delay, can obtain the instantaneous power of net side;

The expression formula of active power instantaneous value and traditional reactive power instantaneous value is:

$\left[\begin{array}{c}P\\ Q\end{array}\right]=\frac{3}{2}\left[\begin{array}{c}{i}_{\mathrm{\&alpha;}}{e}_{\mathrm{\&alpha;}}+i_{\mathrm{\&beta;}}{e}_{\mathrm{\&beta;}}\\ i_{\mathrm{\&alpha;}}{e}_{\mathrm{\&alpha;}}-i_{\mathrm{\&beta;}}{e}_{\mathrm{\&alpha;}}\end{array}\right],$

The expression formula of novel reactive power instantaneous value is:

$Q^{\mathrm{nov}}=\frac{3}{2}(i_{\mathrm{\&alpha;}}{e^{\&prime;}}_{\mathrm{\&alpha;}}+i_{\mathrm{\&beta;}}{e^{\&prime;}}_{\mathrm{\&beta;}});$

Step 3: meritorious and novel idle two frequencys multiplication fluctuate in order to eliminate, active power and the novel reactive power set-point of current on line side sine equal traditional active power and reactive power set-point just through calculating control target, i.e. P ^refand Q ^ref; Wherein, traditional active power set-point P ^reffor given direct voltage with PWM rectifier DC side voltage U _dcdifference through pi regulator be multiplied by U _dc, expression is: $P^{\mathrm{ref}}=(k_p+\frac{k_i}{s})(U_{\mathrm{dc}}^{\mathrm{ref}}-U_{\mathrm{dc}})\&times;U_{\mathrm{dc}}$ (k _pand k _ibe respectively proportional gain and storage gain in pi regulator); The initial set-point Q of reactive power ^refbe made as zero;

Step 4: valuation functions is: g=|P ^ref-P ^k+1|+| Q ^ref-Q ^{nov, k+1}|,

Wherein: the expression formula of next of prediction active power instantaneous value is constantly:

$P^{k+1}=P^k+\frac{{3T}_s}{2L}({\left|e_{\mathrm{\&alpha;\&beta;}}^k\right|}^2-\mathrm{Re}\left(v_{\mathrm{\&alpha;\&beta;}}^{k*}{e}_{\mathrm{\&alpha;\&beta;}}^k\right))-\frac{{\mathrm{RT}}_s}{L}{P}^k-{\mathrm{\&omega;T}}_s{Q}^{\mathrm{nov},k},$

The expression formula of next of prediction novel reactive power instantaneous value is constantly:

$Q^{\mathrm{nov},k+1}=Q^{\mathrm{nov},k}+\frac{{3T}_s}{2L}(\mathrm{Re}\left(e_{\mathrm{\&alpha;\&beta;}}^{k*}{e}_{\mathrm{\&alpha;\&beta;}}^{k^{\&prime;}}\right)-\mathrm{Re}\left(v_{\mathrm{\&alpha;\&beta;}}^{k*}{e}_{\mathrm{\&alpha;\&beta;}}^{k^{\&prime;}}\right))-\frac{{\mathrm{RT}}_s}{L}{Q}^{\mathrm{nov},k}+{\mathrm{\&omega;T}}_s{P}^k$

T wherein _srepresent control cycle.For each voltage vector in two level converters by two formulas above, can obtain corresponding P ^k+1and Q ^{nov, k+1}, further substitution valuation functions can obtain a g value.By all voltage vectors are carried out to above step, finally obtain making the voltage vector of valuation functions minimum to be optimal voltage vector v _opt;

Step 5: active power and the novel reactive power pulsation of take minimum as control action time that target calculates effective vector as:

$\begin{array}{c}{t}_{\mathrm{op}}=\frac{2(P^{\mathrm{ref}}-P^{k+1})(s_1-s_2)+2(Q^{\mathrm{ref}}-Q^{\mathrm{nov},k+1})(s_{11}-s_{22})}{2(s_1^2+s_2^2)+s_{11}^2+s_{22}^2-3(s_1{s}_2+s_{11}{s}_{22})}\\ \frac{T_s[s_2(s_2-s_1)+s_{22}(s_{22}-s_{11})]}{2(s_1^2+s_2^2)+s_{11}^2+s_{22}^2-3(s_1{s}_2+s_{11}{s}_{22})}\end{array},$

Wherein, s ₁and s ₂the rate of change that represents the active power of effective vector zero vector when k is constantly, s ₁₁and s ₂₂the rate of change that represents the novel reactive power of effective vector zero vector when k is constantly, is expressed as follows respectively:

$\left\{\begin{array}{c}{s}_1=\frac{3}{2L}[{\left|e_{\mathrm{\&alpha;\&beta;}}^k\right|}^2-\mathrm{Re}\left(v_{\mathrm{\&alpha;\&beta;}}^{k*}{e}_{\mathrm{\&alpha;\&beta;}}^k\right)]-\frac{R}{L}{P}^k-{\mathrm{\&omega;Q}}^{\mathrm{nov},k}\\ s_2=\frac{3}{2L}{\left|e_{\mathrm{\&alpha;\&beta;}}^k\right|}^2-\frac{R}{L}{P}^k-{\mathrm{\&omega;Q}}^{\mathrm{nov},k}\end{array}\right.,$

$\left\{\begin{array}{c}{s}_{11}=\frac{3}{3L}(\mathrm{Re}\left(e_{\mathrm{\&alpha;\&beta;}}^{k*}{e}_{\mathrm{\&alpha;\&beta;}}^{k^{\&prime;}}\right)-\mathrm{Re}\left(v_{\mathrm{\&alpha;\&beta;}}^{k*}{e}_{\mathrm{\&alpha;\&beta;}}^{k^{\&prime;}}\right))-\frac{R}{L}{Q}^{\mathrm{nov},k}+{\mathrm{\&omega;P}}^k\\ s_{22}=\frac{3}{2L}(\mathrm{Re}\left(e_{\mathrm{\&alpha;\&beta;}}^{k*}{e}_{\mathrm{\&alpha;\&beta;}}^{k^{\&prime;}}\right)-\frac{R}{L}{Q}^{\mathrm{nov},k}+{\mathrm{\&omega;P}}^k\end{array}\right.,$

V wherein _optit is the optimal voltage vector that k chooses by valuation functions constantly; In next control cycle, optimal voltage vector first action time be t _opt, all the other times are distributed to zero vector effect, send respectively the switching tube driving pulse of corresponding voltage vector within time separately.

The validity of method proposed by the invention can draw by the simulation result shown in comparison diagram 4 and Fig. 5, the two test condition is identical, difference is only that Fig. 4 is conventional model prediction direct Power Control, and Fig. 5 has adopted the two vector model prediction of improvement proposed by the invention direct Power Control.In order to further illustrate the validity of put forward the methods of the present invention, the present invention gives experimental result that conventional model prediction direct Power Control and the improved pair of vector model prediction direct Power Control equilibrate to non-equilibrium process by line voltage as shown in Figures 6 and 7.In Fig. 4, waveform is followed successively by active power, traditional reactive power from top to bottom, novel reactive power, and net side three-phase voltage, three-phase current, line voltage starts asymmetric when 0.05s, and also there is distortion in current on line side.After the two vector model prediction of the improvement that adopts the present invention to carry direct Power Control method, the distortion of current on line side is eliminated, and the reactive power of active power and novel definition does not have two frequency multiplication fluctuations simultaneously.Experimental result understands that the present invention improves validity and the practicality of two vector model prediction direct Power Control furtherly, as shown in Figure 6 and Figure 7.In Fig. 6, waveform is from top to bottom once active power, novel reactive power, single-phase voltage and monophase current.As can be seen from Figure 7, when a phase voltage is fallen, there is novel reactive power of distortion while two frequencys multiplication fluctuations occur in monophase current; Yet with after the two vector model prediction of improvement of the present invention direct Power Control method, the monophase current of net side becomes sinusoidal active power and the equal ripple disable of novel reactive power simultaneously.

As can be seen from above, the two vector model prediction direct Power Control methods of three-phase AC/DC converter provided by the invention and device, the method being intended to by existing AC/DC converter model prediction power is controlled is improved, a kind of improved pair of novel vector model prediction direct Power Control proposed, thereby can strengthen the adaptability to unbalanced source voltage, comprise the two frequency multiplication fluctuations of eliminating net side active power, eliminate two frequency multiplication fluctuations of novel reactive power, the pulsation of elimination VD, reduce the harmonic wave of current on line side, reach with balance electrical network under similar operational effect.The two vector model prediction of the improvement direct Power Control that the present invention proposes is applied to novel Reactive power definition in model prediction framework, and do not need line voltage and power network current to carry out positive-negative sequence decomposition, do not need rated output offset simultaneously, under rest frame, realize completely, have that algorithm is simple, dynamic response is fast, to system parameter disturbance strong robustness, the advantage such as easy to implement; In order to obtain better control effect, the present invention in unbalanced source voltage situation, has two voltage vectors to control system this application of policies of two vectors in a control cycle; And emulation and experimental verification validity and the practicality of the two vector models prediction of improvement proposed by the invention direct Power Control.

Improved pair of vector model prediction direct Power Control method of three-phase AC/DC converter and device under unbalanced electric grid voltage based on novel reactive power definition provided by the invention, according to sampling line voltage and power network current and line voltage inhibit signal, calculate instantaneous active power and the novel reactive power of current time, and predict next active power and novel reactive power instantaneous value constantly; By calculating, control target for eliminating the power given value of meritorious and novel idle two frequency multiplication fluctuations, current on line side sine.By active power and novel reactive power instantaneous value and the active power calculating and the novel reactive power reference qref of prediction, utilize valuation functions to select optimal voltage vector, this optimal voltage vector is the effective vector in two vectors; Take active power and novel reactive power pulsation minimum action time in a control cycle that calculates effective vector as controlling target, all the other times in one-period are zero vector action time; By two vectors synthetic in one-period, obtained driving accordingly signal to drive switching tube.

The query vector table that is different from direct Power Control obtains voltage vector, and model prediction direct Power Control is more accurate to choosing of voltage vector, and model prediction direct Power Control is chosen optimal voltage vector by setting up valuation functions; Not having at present any document about model prediction direct Power Control is applied in unbalanced system.It is off the net but also can be operated in the two vector models prediction direct Power Control under unbalanced source voltage that the present invention proposes a kind of desired electrical that not only can be operated in, with respect to traditional Reactive power definition, novel Reactive power definition has better control effect in unbalanced source voltage situation; In order to obtain better control effect, the present invention has adopted two vector control strategy: in a control cycle, adopt two voltage vectors to control switching tube simultaneously; One of them voltage vector is effective vector, and another one voltage vector is zero vector; Under rest frame, by sampling rectifier DC side voltage, line voltage and power network current, utilize the inhibit signal of line voltage and power network current and line voltage, obtain the instantaneous value of meritorious and novel reactive power, and predict next meritorious and novel idle instantaneous value constantly; Calculate to control simultaneously target for eliminating meritorious and novel idle two frequencys multiplication fluctuations, reduce current on line side distortion and obtain active power reference value and novel reactive power reference qref.By active power and novel reactive power instantaneous value and the active power calculating and the novel reactive power reference qref of prediction, utilize valuation functions to select optimal voltage vector, this optimal voltage vector is exactly effective vector; Because zero vector is milder to the control ratio of power, so two vector comprises effective vector zero vector, by two vectors synthetic in one-period, obtained driving accordingly signal to drive switching tube.The features such as the method for the invention has without rotating coordinate transformation, and little, the easy realization of amount of calculation, robustness are good can reduce the harmonic distortion of current on line side when eliminating DC voltage ripple.

Those of ordinary skill in the field are to be understood that: the foregoing is only specific embodiments of the invention; be not limited to the present invention; within the spirit and principles in the present invention all, any modification of making, be equal to replacement, improvement etc., within all should being included in protection scope of the present invention.

Claims (7)

1. two vector model prediction direct Power Control methods, is characterized in that, comprising:

Grid side voltage and current is obtained to grid side voltage signal and the grid side current signal in static two phase coordinates by 3/2 conversion; Further by 1/4 cycle delay function, obtain grid side voltage delay signal;

According to the grid side voltage signal in static two phase coordinates obtaining and grid side current signal and grid side voltage delay signal, analytical Calculation obtains current time active power instantaneous value and novel reactive power instantaneous value; And predict next active power instantaneous value and novel reactive power instantaneous value constantly;

Calculating and controlling target is to eliminate to gain merit to be respectively traditional active power set-point and reactive power set-point with novel two idle frequency multiplication fluctuations and active power set-point and the novel reactive power set-point of current on line side sine;

By next active power instantaneous value and novel reactive power instantaneous value and the active power set-point calculating and reactive power set-point constantly, through valuation functions, obtain optimum voltage vector, this voltage vector is the effective vector in two vectors;

Take active power and novel reactive power pulsation minimum action time that calculates effective vector as controlling target, all the other times are zero vector action time; By two vectors synthetic in one-period, obtained driving accordingly signal to drive switching tube.

2. according to claim 1 pair of vector model prediction direct Power Control method, is characterized in that, described grid side voltage and current is obtained to grid side voltage signal and the grid side current signal in static two phase coordinates by 3/2 conversion; Further by 1/4 cycle delay function, obtain also comprising before the step of grid side voltage delay signal:

Utilize voltage LEM transducer and electric current LEM sensor sample rectifier DC side voltage, grid side voltage and power network current;

Described grid side voltage and current is obtained to grid side voltage signal and the grid side current signal in static two phase coordinates by 3/2 conversion; Further by 1/4 cycle delay function, obtain in the step of grid side voltage delay signal:

Grid side voltage and current is obtained to grid side voltage signal and the grid side current signal in static two phase coordinates by 3/2 conversion, and expression is:

$\left[\begin{array}{c}{e}_{\mathrm{\&alpha;}}\\ e_{\mathrm{\&beta;}}\end{array}\right]=\frac{2}{3}\left[\begin{array}{ccc}1& -\frac{1}{2}& -\frac{1}{2}\\ 0& \frac{\sqrt{3}}{2}& -\frac{\sqrt{3}}{2}\end{array}\right]\left[\begin{array}{c}{e}_a\\ e_b\\ e_c\end{array}\right],$ Wherein, e _α, e _βbe respectively the grid side voltage signal in static α phase coordinates and β phase coordinates;

$\left[\begin{array}{c}{i}_{\mathrm{\&alpha;}}\\ i_{\mathrm{\&beta;}}\end{array}\right]=\frac{2}{3}\left[\begin{array}{ccc}1& -\frac{1}{2}& -\frac{1}{2}\\ 0& \frac{\sqrt{3}}{2}& -\frac{\sqrt{3}}{2}\end{array}\right]\left[\begin{array}{c}{i}_a\\ i_b\\ i_c\end{array}\right],$ Wherein, i _α, i _βbe respectively the grid side current signal in static α phase coordinates and β phase coordinates;

Further by postponing for 1/4 cycle, obtain grid side voltage delay signal, expression is:

$e_{\mathrm{\&alpha;}}^{\&prime;}\left(t\right)=e_{\mathrm{\&alpha;}}(t-\frac{T}{4})$

$e_{\mathrm{\&beta;}}^{\&prime;}\left(t\right)=e_{\mathrm{\&beta;}}(t-\frac{T}{4}),$

Wherein T is a power frequency period, is 0.02s for 50Hz electrical network.

3. according to claim 2 pair of vector model predicted direct Power Control method, it is characterized in that, the grid side voltage signal in static two phase coordinates that described basis obtains and grid side current signal and grid side voltage delay signal, analytical Calculation obtains current time active power instantaneous value and novel reactive power instantaneous value; And predict that in the active power instantaneous value in next moment and the step of novel reactive power instantaneous value, the expression formula of active power instantaneous value and traditional reactive power instantaneous value is:

$\left[\begin{array}{c}P\\ Q\end{array}\right]=\frac{3}{2}\left[\begin{array}{c}{i}_{\mathrm{\&alpha;}}{e}_{\mathrm{\&alpha;}}+i_{\mathrm{\&beta;}}{e}_{\mathrm{\&beta;}}\\ i_{\mathrm{\&alpha;}}{e}_{\mathrm{\&alpha;}}-i_{\mathrm{\&beta;}}{e}_{\mathrm{\&alpha;}}\end{array}\right],$

The expression formula of novel reactive power instantaneous value is:

$Q^{\mathrm{nov}}=\frac{3}{2}(i_{\mathrm{\&alpha;}}{e^{\&prime;}}_{\mathrm{\&alpha;}}+i_{\mathrm{\&beta;}}{e^{\&prime;}}_{\mathrm{\&beta;}}).$

4. according to claim 3 pair of vector model predicted direct Power Control method, it is characterized in that, described in calculate and control target and for eliminating the active power set-point of meritorious and novel two idle frequencys multiplication fluctuations and current on line side sine and novel reactive power set-point, be respectively in the step of traditional active power set-point and reactive power set-point:

Active power set-point is that the difference of given direct voltage and PWM rectifier DC side voltage is passed through pi regulator and is multiplied by PWM rectifier DC side voltage, and expression is:

$P^{\mathrm{ref}}=(k_p+\frac{k_i}{s})(U_{\mathrm{dc}}^{\mathrm{ref}}-U_{\mathrm{dc}})\&times;U_{\mathrm{dc}};$

Reactive power set-point Q ^refbe made as zero.

5. according to claim 4 pair of vector model prediction direct Power Control method, is characterized in that, described valuation functions is: g=|P ^ref-P ^k+1|+| Q ^ref-Q ^{nov, k+1}|,

Wherein: $P^{k+1}=P^k+\frac{{3T}_s}{2L}({\left|e_{\mathrm{\&alpha;\&beta;}}^k\right|}^2-\mathrm{Re}\left(v_{\mathrm{\&alpha;\&beta;}}^{k*}{e}_{\mathrm{\&alpha;\&beta;}}^k\right))-\frac{{\mathrm{RT}}_s}{L}{P}^k-{\mathrm{\&omega;T}}_s{Q}^{\mathrm{nov},k},$

$Q^{\mathrm{nov},k+1}=Q^{\mathrm{nov},k}+\frac{{3T}_s}{2L}(\mathrm{Re}\left(e_{\mathrm{\&alpha;\&beta;}}^{k*}{e}_{\mathrm{\&alpha;\&beta;}}^{k^{\&prime;}}\right)-\mathrm{Re}\left(v_{\mathrm{\&alpha;\&beta;}}^{k*}{e}_{\mathrm{\&alpha;\&beta;}}^{k^{\&prime;}}\right))-\frac{{\mathrm{RT}}_s}{L}{Q}^{\mathrm{nov},k}+{\mathrm{\&omega;T}}_s{P}^k,$

T wherein _srepresent control cycle; For each voltage vector in two level converters, by two formulas above, can obtain corresponding next active power instantaneous value and next novel reactive power instantaneous value constantly constantly, further substitution valuation functions can obtain a valuation functions value; By all voltage vectors are carried out to above treatment step, finally obtain making the voltage vector of valuation functions minimum to be optimal voltage vector.

6. according to claim 5 pair of vector model predicted direct Power Control method, it is characterized in that, active power and the novel reactive power pulsation of take is minimum to be calculated as controlling target in the step of action time of effective vector, and the expression formula of described effective vector action time is:

$\begin{array}{c}{t}_{\mathrm{op}}=\frac{2(P^{\mathrm{ref}}-P^{k+1})(s_1-s_2)+2(Q^{\mathrm{ref}}-Q^{\mathrm{nov},k+1})(s_{11}-s_{22})}{2(s_1^2+s_2^2)+s_{11}^2+s_{22}^2-3(s_1{s}_2+s_{11}{s}_{22})}\\ \frac{T_s[s_2(s_2-s_1)+s_{22}(s_{22}-s_{11})]}{2(s_1^2+s_2^2)+s_{11}^2+s_{22}^2-3(s_1{s}_2+s_{11}{s}_{22})}\end{array},$

Wherein, s ₁and s ₂the rate of change of the active power of effective vector zero vector while representing any time, s ₁₁and s ₂₂the rate of change of the novel reactive power of effective vector zero vector while representing any time, is expressed as follows respectively:

$\left\{\begin{array}{c}{s}_1=\frac{3}{2L}[{\left|e_{\mathrm{\&alpha;\&beta;}}^k\right|}^2-\mathrm{Re}\left(v_{\mathrm{\&alpha;\&beta;}}^{k*}{e}_{\mathrm{\&alpha;\&beta;}}^k\right)]-\frac{R}{L}{P}^k-{\mathrm{\&omega;Q}}^{\mathrm{nov},k}\\ s_2=\frac{3}{2L}{\left|e_{\mathrm{\&alpha;\&beta;}}^k\right|}^2-\frac{R}{L}{P}^k-{\mathrm{\&omega;Q}}^{\mathrm{nov},k}\end{array}\right.,$

$\left\{\begin{array}{c}{s}_{11}=\frac{3}{3L}(\mathrm{Re}\left(e_{\mathrm{\&alpha;\&beta;}}^{k*}{e}_{\mathrm{\&alpha;\&beta;}}^{k^{\&prime;}}\right)-\mathrm{Re}\left(v_{\mathrm{\&alpha;\&beta;}}^{k*}{e}_{\mathrm{\&alpha;\&beta;}}^{k^{\&prime;}}\right))-\frac{R}{L}{Q}^{\mathrm{nov},k}+{\mathrm{\&omega;P}}^k\\ s_{22}=\frac{3}{2L}(\mathrm{Re}\left(e_{\mathrm{\&alpha;\&beta;}}^{k*}{e}_{\mathrm{\&alpha;\&beta;}}^{k^{\&prime;}}\right)-\frac{R}{L}{Q}^{\mathrm{nov},k}+{\mathrm{\&omega;P}}^k\end{array}\right.,$

Wherein, v _optit is the optimal voltage vector of choosing by valuation functions any time; t _optfor the optimal voltage vector in next control cycle action time first, all the other times are distributed to zero vector effect, send respectively the switching tube driving pulse of corresponding voltage vector within time separately.

7. two vector models of an employing two vector models prediction direct Power Control methods as described in claim 1-6 any one are predicted direct Power Control devices, it is characterized in that, comprise the three-phase voltage source, three-phase filter inductance, rectifier bridge main circuit, DC bus capacitor, the load that connect successively; And, from three-phase voltage source output terminal and three-phase filter inductance output, carry out respectively the electric current and voltage sample circuit of voltage, current sample, the electric current and voltage data of electric current and voltage sample circuit are carried out to the dsp controller of s operation control, drive circuit;

Wherein, described electric current and voltage sample circuit utilizes voltage hall sensor and current Hall transducer to gather respectively three-phase net side alternating voltage, alternating current and rectifier DC side voltage, enters dsp controller and be converted to digital signal after signal conditioning circuit; Dsp controller completes the computing of the two vector model prediction direct Power Control methods as described in claim 1-6 any one, exports six road pwm pulses, then after overdrive circuit, obtains the final driving signal of six switching tubes of rectifier.