CN101719672B - Active power filter and energy reforming control method thereof - Google Patents

Abstract

The invention relates to an active power filter and an energy reforming control method thereof. The active power filter comprises a harmonic current detection module and a compensating current control module, wherein the harmonic current detection module is connected with a feeder line and used for collecting load current, obtaining the harmonic components of the load current and generating a compensating current command signal after being reversed in polarity; the compensating current control module is connected with the harmonic current detection module and the feeder line and used for generating compensating current according to the compensating current command signal through an energy reforming control module and outputting the compensating current to the feeder line, and the compensating current and the load current have equal harmonic component and reverse directions. The invention can enable the minimum value of the energy function of the active power filter to be stabilized at an expected balance point by the energy reforming control module, enhance the steady state performance and the load disturbance resisting capacity of the active power filter and fundamentally ensure the coordination between the stability and the control law of a system during load fluctuation and the balance point.

Description

Active Power Filter-APF and energy reforming control method thereof

Technical field

The present invention relates to a kind of filter and control method, particularly a kind of Active Power Filter-APF and energy reforming control method thereof.

Background technology

In recent years, the quality of power supply harmonic problem in the power distribution network becomes increasingly conspicuous.For addressing this problem, prior art has proposed various solutions, and the solution that wherein adopts Active Power Filter-APF (Active PowerFilter is called for short APF) to compensate obtains widespread usage.The performance of Active Power Filter-APF depends primarily on electronic power switch device, circuit topological structure and controlling models.Under the certain situation of electronic power switch device and circuit topological structure, the performance of source filter depends primarily on controlling models.

Conventional controlling models comprises integral element, can make system output indifference ground follow the tracks of constant signal, but system does not have steady-state error can only guarantee that reference signal is direct current signal the time.Because the reference signal of Active Power Filter-APF is the cyclical signal that a plurality of frequencies are superimposed; Controlling models can't be accomplished the error free tracking to cyclical signal; Therefore compensation precision is poor; Even adopt the method effect of scaling up parameter also very limited, and the increase of scale parameter also possibly destroy the stability of system.Though remedied the problem of compensation precision to a great extent based on the repetition control technology of internal model principle; But repeat control technology self deadly defect is arranged; This control technology lags behind a primitive period to the control action of tracking error, and therefore in nonlinear load sudden change dynamic process, the output offset current has a primitive period to be in runaway condition basically; Fluctuating widely and distorting appears in output order, the compensation performance variation of system.Linear Control technology (like Model Reference Adaptive Control, Sliding mode variable structure control, ANN Control and modern control theory etc.) is mainly according to the local linearization method; Can obtain the better controlling effect under given conditions; But because the dynamical equation of Active Power Filter-APF is non-linear, so also there is the defective of compensation performance difference in the Linear Control technology.Though can obtain nonlinear control law based on differential geometric non linear system LINEARIZED CONTROL model, ignore the nonlinear element of system; Though the controlling models based on the Lyapunov function can guarantee system's global stability, when running into big load fluctuation interference, the non-zero steady-state error can appear in its state variable.

For this reason, prior art has proposed a kind of passivity control (Passivity-basedController is called for short PBC) method, is mainly used in the asymptotic tracking of dc capacitor voltage harmonic electric current.People such as MATTAVELLI utilize the output FEEDBACK CONTROL; The overall stable harmonic current of having realized the passivity control method detects and follows the tracks of; But weak point is the convergence rate of reference harmonic current tracking error and is decided by mechanical damping (MATTAVELLI P, the STANKOVIC AM of Active Power Filter-APF; Dynamical phasors in modeling and control of active filters; Proceedings of 1999 IEEE International Symposium on Circuits andSystems; Vol 5, May 30-Jun 2,1999, and Orlando, FL, USA.Piscataway, NJ, USA:IEEE, 1999:278-282).People such as STANKOVIC introduce the lf technology design of passivity control; Through annotate the mode of people's machinery damping to closed loop, solved the limited problem of harmonic current tracking error convergence rate, be permanent prerequisite (STANKOVIC AM but load need be arranged; ESCOBAR G, MATTAVELLI P; Passivity-based controller for harmoniccompensation in distribution lines with nonlinear loads; Proceedings of 2000 IEEE 31st Annual Power Electronics SpecialistsConference; Vol 3, Jun 18-23, and 2000, Galway, UK.Piscataway, NJ, USA, IEEE, 2000:1143-1148).

Though above-mentioned various passivity control method has been improved the performance of Active Power Filter-APF from different perspectives, stability when all having the fluctuation of proof load simultaneously and the coordination between system's control law and the balance point.Assumed load was constant when the stability the during fluctuation of load was meant CONTROLLER DESIGN, when load changes, was easy to generate current distortion, even made system unstable, thereby the range of application of nonlinear methods such as passivity control is very limited.Coordination between system's control law and the balance point is meant when finding the solution control law that a redundant equation appears in model equation, when real system is controlled, can not guarantee to satisfy the constraint of redundant equation, makes system steady state deviation occur.

Summary of the invention

The purpose of this invention is to provide a kind of Active Power Filter-APF and energy reforming control method thereof, stability when effectively proof load is fluctuateed and the coordination between system's control law and the balance point.

To achieve these goals, the invention provides a kind of Active Power Filter-APF, comprising:

The harmonic current detection module is connected with feed line, is used to gather load current, obtains the harmonic component of load current, with generating the offset current command signal after its reversed polarity;

The offset current control module; Be connected with feed line with said harmonic current detection module; Be used for generating offset current and exporting the harmonic component equal and opposite in direction of said offset current and load current, in the opposite direction through the energy reforming controlling models to said feed line according to said offset current command signal.

Said offset current control module comprises:

Energy reforming controlling models unit is connected with said harmonic current detection module, is used to receive said offset current command signal, generates the offset current control signal according to said offset current command signal through the energy reforming controlling models;

Drive circuit is connected with said energy reforming controlling models unit, is used for said offset current control signal is amplified;

Power cell is connected with said drive circuit, is used for generating offset current by said driving circuit drives and exports the harmonic component equal and opposite in direction of said offset current and load current, in the opposite direction to said feed line.

Said energy reforming controlling models is:

$\left\{\begin{array}{c}{u}_d=-4\mathrm{\&omega;L}[c_2-\frac{2c_4-R_C{E}_m^2({\mathrm{Li}}_{\mathrm{cd}}+c_3)({\mathrm{<figure-callout\; id="2"\; label="e"\; filenames="H2009102421409E00011.png,H2009102421409E00021.png"\; state="\{\{state\}\}">e</figure-callout>}}^{2{\mathrm{Li}}_{\mathrm{cq}}}+1)}{({\mathrm{<figure-callout\; id="2"\; label="e"\; filenames="H2009102421409E00011.png,H2009102421409E00021.png"\; state="\{\{state\}\}">e</figure-callout>}}^{2{\mathrm{Li}}_{\mathrm{cq}}}+1)(E_m{R}_C{\mathrm{Cu}}_{\mathrm{dc}}-2{\mathrm{<figure-callout\; id="2"\; label="c"\; filenames="H2009102421409E00011.png,H2009102421409E00021.png"\; state="\{\{state\}\}">c</figure-callout>}}_2{\mathrm{Li}}_{\mathrm{cq}}+c_1)}]\\ u_q=\mathrm{\&omega;L}\frac{E_m{R}_C{\mathrm{Cu}}_{\mathrm{dc}}-2{\mathrm{<figure-callout\; id="2"\; label="c"\; filenames="H2009102421409E00011.png,H2009102421409E00021.png"\; state="\{\{state\}\}">c</figure-callout>}}_2{\mathrm{Li}}_{\mathrm{cq}}+c_1}{R_C{E}_m({\mathrm{Li}}_{\mathrm{cd}}+c_3)}\end{array}\right.$

c _{I, i=1,2,3,4}The condition that satisfies is: c ₂Be any real number, c ₃＞0,

${\mathrm{<figure-callout\; id="1"\; label="c"\; filenames="H2009102421409E00011.png"\; state="\{\{state\}\}">c</figure-callout>}}_1=-\frac{{\mathrm{Li}}_{\mathrm{cq}*}}{C}(2{\mathrm{Li}}_{\mathrm{cd}*}+2{\mathrm{<figure-callout\; id="3"\; label="c"\; filenames="H2009102421409E00011.png"\; state="\{\{state\}\}">c</figure-callout>}}_3+R_C{E}_{m}C),{\mathrm{<figure-callout\; id="4"\; label="c"\; filenames="H2009102421409E00011.png"\; state="\{\{state\}\}">c</figure-callout>}}_4=-\frac{{\mathrm{<figure-callout\; id="2"\; label="c"\; filenames="H2009102421409E00011.png,H2009102421409E00021.png"\; state="\{\{state\}\}">c</figure-callout>}}_2{\mathrm{Cu}}_{\mathrm{dc}*}}{{\mathrm{Li}}_{\mathrm{cd}*}+2{\mathrm{<figure-callout\; id="3"\; label="c"\; filenames="H2009102421409E00011.png"\; state="\{\{state\}\}">c</figure-callout>}}_3}+\frac{c_1{c}_2}{R_C{E}_m({\mathrm{Li}}_{\mathrm{cd}*}+2c_3)}$

Wherein, u _d, u _qBe respectively equivalent d-q axle control variables constant in the offset current control variables, L is an equivalent inductance, and C is a capacitor, R _CBe the equivalent resistance of capacitor, i _Cd, i _CqBe respectively the equivalent d-q shaft current of offset current, u _DcBe capacitor terminal voltage, E _mBe system's (electrical network) three-phase alternating current line voltage effective value,

With

Be respectively offset current command signal equivalence d-q shaft current,

Capacitor terminal voltage during for stable state.To achieve these goals, the present invention also provides a kind of Active Power Filter-APF energy reforming control method, comprising:

Gather load current from feed line, obtain the harmonic component of load current, with generating the offset current command signal after its reversed polarity;

Generate offset current and export the harmonic component equal and opposite in direction of said offset current and load current, in the opposite direction through the energy reforming controlling models according to said offset current command signal to said feed line.

Comprise through energy reforming controlling models generation offset current and to said feed line output according to said offset current command signal:

Generate the offset current control signal according to said offset current command signal through the energy reforming controlling models;

Said offset current control signal is amplified back generation offset current export the harmonic component equal and opposite in direction of said offset current and load current, in the opposite direction to said feed line.

Said energy reforming controlling models is:

$\left\{\begin{array}{c}{u}_d=-4\mathrm{\&omega;L}[c_2-\frac{2c_4-R_C{E}_m^2({\mathrm{Li}}_{\mathrm{cd}}+c_3)({\mathrm{<figure-callout\; id="2"\; label="e"\; filenames="H2009102421409E00011.png,H2009102421409E00021.png"\; state="\{\{state\}\}">e</figure-callout>}}^{2{\mathrm{Li}}_{\mathrm{cq}}}+1)}{({\mathrm{<figure-callout\; id="2"\; label="e"\; filenames="H2009102421409E00011.png,H2009102421409E00021.png"\; state="\{\{state\}\}">e</figure-callout>}}^{2{\mathrm{Li}}_{\mathrm{cq}}}+1)(E_m{R}_C{\mathrm{Cu}}_{\mathrm{dc}}-2{\mathrm{<figure-callout\; id="2"\; label="c"\; filenames="H2009102421409E00011.png,H2009102421409E00021.png"\; state="\{\{state\}\}">c</figure-callout>}}_2{\mathrm{Li}}_{\mathrm{cq}}+c_1)}]\\ u_q=\mathrm{\&omega;L}\frac{E_m{R}_C{\mathrm{Cu}}_{\mathrm{dc}}-2{\mathrm{<figure-callout\; id="2"\; label="c"\; filenames="H2009102421409E00011.png,H2009102421409E00021.png"\; state="\{\{state\}\}">c</figure-callout>}}_2{\mathrm{Li}}_{\mathrm{cq}}+c_1}{R_C{E}_m({\mathrm{Li}}_{\mathrm{cd}}+c_3)}\end{array}\right.$

c _{I, i=1,2,3,4}The condition that satisfies is: c ₂Be any real number, c ₃＞0,

${\mathrm{<figure-callout\; id="1"\; label="c"\; filenames="H2009102421409E00011.png"\; state="\{\{state\}\}">c</figure-callout>}}_1=-\frac{{\mathrm{Li}}_{\mathrm{cq}*}}{C}(2{\mathrm{Li}}_{\mathrm{cd}*}+2{\mathrm{<figure-callout\; id="3"\; label="c"\; filenames="H2009102421409E00011.png"\; state="\{\{state\}\}">c</figure-callout>}}_3+R_C{E}_{m}C),{\mathrm{<figure-callout\; id="4"\; label="c"\; filenames="H2009102421409E00011.png"\; state="\{\{state\}\}">c</figure-callout>}}_4=-\frac{{\mathrm{<figure-callout\; id="2"\; label="c"\; filenames="H2009102421409E00011.png,H2009102421409E00021.png"\; state="\{\{state\}\}">c</figure-callout>}}_2{\mathrm{Cu}}_{\mathrm{dc}*}}{{\mathrm{Li}}_{\mathrm{cd}*}+2{\mathrm{<figure-callout\; id="3"\; label="c"\; filenames="H2009102421409E00011.png"\; state="\{\{state\}\}">c</figure-callout>}}_3}+\frac{c_1{c}_2}{R_C{E}_m({\mathrm{Li}}_{\mathrm{cd}*}+2c_3)}$

Wherein, u _d, u _qBe respectively equivalent d-q axle control variables constant in the offset current control variables, L is an equivalent inductance, and C is a capacitor, R _CBe the equivalent resistance of capacitor, i _Cd, i _CqBe respectively the equivalent d-q shaft current of offset current, u _DcBe capacitor terminal voltage, E _mBe system's (electrical network) three-phase alternating current line voltage effective value,

With

Be respectively offset current command signal equivalence d-q shaft current,

Capacitor terminal voltage during for stable state.

The present invention proposes a kind of Active Power Filter-APF and energy reforming control method thereof; Through applied energy shaping controlling models; Can make Active Power Filter-APF energy function minimum value be stabilized in the balance point of expectation; Improve the steady-state behaviour and the anti-load disturbance ability of Active Power Filter-APF, stability when fundamentally proof load is fluctuateed and the coordination between system's control law and the balance point.

Description of drawings

Fig. 1 is the structural representation of Active Power Filter-APF of the present invention;

Fig. 2 simplifies main circuit diagram for Active Power Filter-APF three-phase of the present invention;

Fig. 3 is the flow chart of Active Power Filter-APF energy reforming control method of the present invention.

Description of reference numerals:

The 1-AC power; The 2-nonlinear load; The 3-feed line;

4-harmonic current detection module; 5-offset current control module; 51-energy reforming controlling models unit;

The 52-drive circuit; The 53-power cell.

Embodiment

Through accompanying drawing and embodiment, technical scheme of the present invention is done further detailed description below.

Fig. 1 is the structural representation of Active Power Filter-APF of the present invention.As shown in Figure 1, electric power system comprise AC power 1, nonlinear load 2 and be connected AC power 1 and nonlinear load 2 between feed line 3, nonlinear load 2 is a harmonic source, its produces harmonic current and consumes idlely, AC power 1 produces alternating voltage u _sWith source current i _s, AC power 1 produces load current i through feed line 3 to nonlinear load 2 power supplies _lActive Power Filter-APF of the present invention comprises harmonic current detection module 4 and offset current control module 5, and harmonic current detection module 4 is connected with feed line 3, is used to gather load current i _l, obtain load current i _lHarmonic component i _Th, with load current i _lHarmonic component i _ThCurrent command signal i by way of compensation after the reversed polarity _c ^*Send to offset current control module 5, offset current control module 5 is connected with feed line 3 with harmonic current detection module 4 respectively, is used for the offset current command signal i that receives according to from harmonic current detection module 4 _c ^*Generate offset current i through the energy reforming controlling models _cTo feed line 3 outputs, offset current i _cHarmonic component i with load current _ThEqual and opposite in direction, in the opposite direction, both cancel each other, and have reached elimination source current i _sIn the purpose of harmonic wave, make source current i _sIn only contain first-harmonic and do not contain harmonic wave, finally obtain the first-harmonic sinusoidal current of expecting.In addition, harmonic current detection module 4 also is connected with the output of offset current control module 5, is used to gather the offset current i of offset current control module 5 actual outputs _c, and send to offset current control module 5.

Offset current control module 5 of the present invention comprises energy reforming controlling models unit 51, drive circuit 52 and power cell 53; Energy reforming controlling models unit 51 is connected with harmonic current detection module 4, is used to receive the offset current command signal i that harmonic current detection module 4 sends _c ^*Offset current i with reality output _cGenerate the offset current control variables according to the energy reforming controlling models, drive circuit 52 is connected with energy reforming controlling models unit 51, is used for the offset current control variables that received energy shaping controlling models unit 51 sends; Generate the offset current driving parameters according to the offset current control variables; Power cell 53 is connected with feed line 3 with drive circuit 52 respectively, is used to receive the offset current driving parameters that drive circuit 52 sends, and generates offset current i according to the offset current driving parameters _cTo feed line 3 outputs.In the practical application, power cell 53 can adopt pwm converter, and pwm converter is well known to those skilled in the art with an amplifying signal function drive circuit, repeats no more here.

In the technique scheme of the present invention; At first set up based on the controlled Hamilton's dissipation of port (Portcontrolled Hamiltonian Damping; Abbreviation PCHD) APF model and Hamiltonian function; Then based on the PCHD model; Application ID A-PBC (Interconnection and damping assignment Passivity-based Controller) theory can form the energy reforming controlling models of three-phase voltage type PWM Active Power Filter-APF, and applied energy shaping controlling models of the present invention is according to offset current command signal i _c ^*Can generate the offset current control variables.Active Power Filter-APF applied energy shaping controlling models of the present invention can make Active Power Filter-APF energy function minimum value be stabilized in the balance point of expectation; Improve the steady-state behaviour and the anti-load disturbance ability of Active Power Filter-APF, stability when fundamentally proof load is fluctuateed and the coordination between system's control law and the balance point.

Fig. 2 simplifies main circuit diagram for Active Power Filter-APF three-phase of the present invention.As shown in Figure 2, u _Sa, u _Sb, u _ScThe a phase, b that is respectively system mutually and c supply voltage mutually, R is that the loss of device is used equivalent resistance, R _CBe the equivalent resistance of capacitor, i _Ca, i _Cb, i _CcBe respectively the harmonic current that Active Power Filter-APF sends, u _Ra, u _Rb, u _RcBe respectively a phase, b phase and c phase voltage that Active Power Filter-APF sends, u _Ra=u _au _Dc, u _Rb=u _bu _Dc, u _Rc=u _cu _Dc,, u _a, u _b, u _cBe respectively the control variables under the abc reference axis, u _DcBe capacitor terminal voltage, S _A1, S _A2, S _B1, S _B2, S _C1, S _C2Be respectively switching tube.According to the state space method of average, can use the mean value place of switches function of switch function in a switch periods itself, obtain in its rest frame to time continuum of states space average Mathematical Modeling:

$\left\{\begin{array}{c}L\frac{{\mathrm{di}}_{\mathrm{ca}}}{\mathrm{dt}}=u_{\mathrm{sa}}-i_{\mathrm{ca}}R-u_{\mathrm{ra}}\\ L\frac{{\mathrm{di}}_{\mathrm{ca}}}{\mathrm{dt}}=u_{\mathrm{sb}}-i_{\mathrm{cb}}R-u_{\mathrm{rb}}\\ L\frac{{\mathrm{di}}_{\mathrm{ca}}}{\mathrm{dt}}=u_{\mathrm{sc}}-i_{\mathrm{cc}}R-u_{\mathrm{rc}}\\ C\frac{{\mathrm{du}}_{\mathrm{dc}}}{\mathrm{dt}}=u_a{i}_{\mathrm{ca}}+u_b{i}_{\mathrm{cb}}+u_c{i}_{\mathrm{cc}}-\frac{u_{\mathrm{dc}}}{R_C}\end{array}\right.---\left(1\right)$

Wherein, R is that equivalent resistance is used in the loss of device, and L is an equivalent inductance, and C is a capacitor; R _CEquivalent resistance for capacitor.

Through the Park transformation matrix

$T=\sqrt{\frac{2}{3}}\left[\begin{array}{ccc}\sin \mathrm{\&omega;t}& \sin (\mathrm{\&omega;t}-\frac{2}{3}\mathrm{\&pi;})& \sin (\mathrm{\&omega;t}+\frac{2}{3}\mathrm{\&pi;})\\ \cos \mathrm{\&omega;t}& \cos (\mathrm{\&omega;t}-\frac{2}{3}\mathrm{\&pi;})& \cos (\mathrm{\&omega;t}+\frac{2}{3}\mathrm{\&pi;})\\ \frac{1}{\sqrt{2}}& \frac{1}{\sqrt{2}}& \frac{1}{\sqrt{2}}\end{array}\right]---\left(2\right)$

The d-q synchronous rotating frame that obtains of conversion in Mathematical Modeling:

In the formula, E _mBe system's (electrical network) three-phase alternating current line voltage effective value, i _Cd, i _CqBe respectively the equivalent d-q shaft current of offset current; u _d, u _qBe respectively equivalent d-q axle control variables in the offset current control variables.

The state variable of setting up departments and uniting: x=(x ₁x ₂x ₃) ^T=(Li _CdLi _CqCu _Dc) ^T

The total energy function of system:

$H\left(x\right)=\frac{1}{2L}{x}_1^2+\frac{1}{2L}{x}_2^2+\frac{1}{2C}{x}_3^2---\left(4\right)$

Then, the controlled dissipation PCHD of port system is:

Or

That is:

$+\left[\begin{array}{ccc}0& 0& -\frac{u_{\mathrm{<figure-callout\; id="2"\; label="d"\; filenames="H2009102421409E00011.png,H2009102421409E00021.png"\; state="\{\{state\}\}">d</figure-callout>}}}{2}\\ 0& 0& -\frac{u_q}{2}\\ \frac{u_d}{2}& \frac{u_{\mathrm{<figure-callout\; id="2"\; label="q"\; filenames="H2009102421409E00011.png,H2009102421409E00021.png"\; state="\{\{state\}\}">q</figure-callout>}}}{2}& 0\end{array}\right]\left[\begin{array}{c}\frac{\&PartialD;H\left(x\right)}{{\&PartialD;x}_1}\\ \frac{\&PartialD;H\left(x\right)}{\&PartialD;x_2}\\ \frac{\&PartialD;H\left(x\right)}{{\&PartialD;x}_3}\end{array}\right]+\left[\begin{array}{c}{E}_m\\ 0\\ 0\end{array}\right]---\left(6\right)$

Wherein

$J\left(x\right)=\left[\begin{array}{ccc}0& \mathrm{\&omega;L}& -\frac{u_d}{2}\\ -\mathrm{\&omega;L}& 0& -\frac{u_q}{2}\\ \frac{u_d}{2}& \frac{u_{\mathrm{<figure-callout\; id="2"\; label="q"\; filenames="H2009102421409E00011.png,H2009102421409E00021.png"\; state="\{\{state\}\}">q</figure-callout>}}}{2}& 0\end{array}\right],$ $R\left(x\right)=\left[\begin{array}{ccc}{R}_L& 0& 0\\ 0& R_L& 0\\ 0& 0& \frac{1}{R_C}\end{array}\right],$ $g\left(x\right)=\left[\begin{array}{c}{E}_m\\ 0\\ 0\end{array}\right]---\left(7\right)$

According to PCHD, confirm to make system capacity in the minimum control law of desired point.To this, need confirm control law by following requirement.

Given J (x, u), R (x), H (x), a certain expectation of g (x) and system quelling balance point x ₊∈ R ⁿ, seek function β (x), J _a(x), R _a(x) and a vector function K (x) satisfy

$[J(x,\mathrm{\&beta;}\left(x\right))+J_a\left(x\right)-(R\left(x\right)+R_a\left(x\right))]K\left(x\right)$

$=-[J_a\left(x\right)-R_a\left(x\right)]\frac{\&PartialD;H}{\&PartialD;x}\left(x\right)+g(x,\mathrm{\&beta;}\left(x\right))u---\left(8\right)$

And when following condition is set up

1. the Hamiltonian structure keeps

J _d(x)：＝J(x，β(x))+J _a(x)＝-[J(x，β(x)+J _a(x))] ^T (9-1)

R _d(x)：＝R(x)+R _a(x)＝[R(x)+R _a(x)] ^T≥0 (9-2)

2. integrability condition

$\frac{\&PartialD;K}{\&PartialD;x}\left(x\right)={\left[\frac{\&PartialD;K}{\&PartialD;x}\left(x\right)\right]}^T---\left(10\right)$

3. closed-loop system design balance point exists

$K\left(x_{+}\right)=-\frac{\&PartialD;H}{\&PartialD;x}\left(x_{+}\right)---\left(11\right)$

Be the H of system _dAt system balancing point x ₊The place has minimum value.

4. Lyapunov is stable

The Jacobian matrix of K (x) is put x in system balancing ₊The place satisfies the boundedness condition

$\frac{{\&PartialD;}^{2}K\left(x_{+}\right)}{{\&PartialD;x}^2}>-\frac{{\&PartialD;}^{2}H}{{\&PartialD;x}^2}\left(x_{+}\right)---\left(12\right)$

Show that this balance point of system is isolated balance point, then the PCHD system can obtain the described closed-loop system of following formula through state feedback control law u=β (x)

Wherein, system's syndeton matrix $J_d\left(x\right)=-J_d^T\left(x\right),$

The system damping structure matrix $R_d\left(x\right)=R_d^T\left(x\right)\&GreaterEqual;0,$ H _d(x) :=H (x)+H _a(x),

$\frac{\&PartialD;H_a}{\&PartialD;x}\left(x\right)=K\left(x\right)---\left(14\right)$

And x ₊To become the closed-loop system stable equilibrium point, corresponding stabilization control law u=β (x) can directly calculate according to following formula

$\mathrm{\&beta;}\left(x\right)={\left[g^T\left(x\right)g\left(x\right)\right]}^{-1}{g}^T\left(x\right)\&times;$

$\left\{\right[J\left(x\right)+J_a\left(x\right)-(R\left(x\right)+R_a\left(x\right))]\frac{{\&PartialD;H}_a}{\&PartialD;x}\left(x\right)+[J_a\left(x\right)-R_a\left(x\right)]\frac{\&PartialD;H}{\&PartialD;x}\left(x\right)---\left(15\right)$

And assurance closed-loop system The maximum invariant set of progressive stability

Equal { x ₊, can estimate domain of attraction { x ∈ R through maximum border level set ⁿ| H _d≤c}.For the closed loop controlled system; The maximum invariant set of shaping gained closed loop

only comprises the balance point that is designed; According to the LaSalle principle of invariance, system keeps progressive stability.STATE FEEDBACK CONTROL rate u=β (x) is the subduer of controlled PCHD system, and shaping gained energy function H _d(x) be the closed loop controlled system

Energy type Lyapunov function.

The shunt active power FILTER TO CONTROL rule that satisfies above-mentioned condition is:

$\left\{\begin{array}{c}{u}_d=-4\mathrm{\&omega;L}[c_2-\frac{2c_4-R_C{E}_m^2({\mathrm{Li}}_{\mathrm{cd}}+c_3)({\mathrm{<figure-callout\; id="2"\; label="e"\; filenames="H2009102421409E00011.png,H2009102421409E00021.png"\; state="\{\{state\}\}">e</figure-callout>}}^{2{\mathrm{Li}}_{\mathrm{cq}}}+1)}{({\mathrm{<figure-callout\; id="2"\; label="e"\; filenames="H2009102421409E00011.png,H2009102421409E00021.png"\; state="\{\{state\}\}">e</figure-callout>}}^{2{\mathrm{Li}}_{\mathrm{cq}}}+1)(E_m{R}_C{\mathrm{Cu}}_{\mathrm{dc}}-2{\mathrm{<figure-callout\; id="2"\; label="c"\; filenames="H2009102421409E00011.png,H2009102421409E00021.png"\; state="\{\{state\}\}">c</figure-callout>}}_2{\mathrm{Li}}_{\mathrm{cq}}+c_1)}]\\ u_q=\mathrm{\&omega;L}\frac{E_m{R}_C{\mathrm{Cu}}_{\mathrm{dc}}-2{\mathrm{<figure-callout\; id="2"\; label="c"\; filenames="H2009102421409E00011.png,H2009102421409E00021.png"\; state="\{\{state\}\}">c</figure-callout>}}_2{\mathrm{Li}}_{\mathrm{cq}}+c_1}{R_C{E}_m({\mathrm{Li}}_{\mathrm{cd}}+c_3)}\end{array}\right.---\left(16\right)$

In the formula, constant c _{I, i=1,2,3,4}The condition that satisfies is: c ₂It is any real number; c ₃＞0;

$c_1=-\frac{{\mathrm{Li}}_{\mathrm{cq}*}}{C}(2{\mathrm{Li}}_{\mathrm{cd}*}+2c_3+R_C{E}_{m}C),{\mathrm{<figure-callout\; id="4"\; label="c"\; filenames="H2009102421409E00011.png"\; state="\{\{state\}\}">c</figure-callout>}}_4=-\frac{{\mathrm{<figure-callout\; id="2"\; label="c"\; filenames="H2009102421409E00011.png,H2009102421409E00021.png"\; state="\{\{state\}\}">c</figure-callout>}}_2{\mathrm{Cu}}_{\mathrm{dc}*}}{{\mathrm{Li}}_{\mathrm{cd}*}+2c_3}+\frac{c_1{c}_2}{R_C{E}_m({\mathrm{Li}}_{\mathrm{cd}*}+2c_3)}.$

In the formula; and

is respectively offset current command signal equivalence d-q shaft current,

capacitor terminal voltage when being stable state.Formula (16) is energy reforming controlling models of the present invention, u _d, u _qEquivalent d-q axle control variables generates the offset current control signal in the Current Control variable by way of compensation, and the offset current control signal is actually a kind of duty cycle parameters, is used for the closure of power controlling unit switch pipe and the time of disconnection.

In the practical application, electric power system also comprises high pass filter HPF (High Pass Filter), and high pass filter HPF is by R _HC _HL _HForm, mainly be used for filtering switching noise electric current.

Fig. 3 is the flow chart of Active Power Filter-APF energy reforming control method of the present invention, comprising:

Step 1, gather load current, obtain the harmonic component of load current, generating the offset current command signal after its reversed polarity from feed line;

Step 2, generate offset current through the energy reforming controlling models and to said feed line output, the harmonic component equal and opposite in direction of said offset current and load current, in the opposite direction according to said offset current command signal.

Wherein, step 2 comprises: generate the offset current control signal according to said offset current command signal through the energy reforming controlling models; Said offset current control signal is amplified back generation offset current export the harmonic component equal and opposite in direction of said offset current and load current, in the opposite direction to said feed line.

Active Power Filter-APF energy reforming control method of the present invention is to adopt aforementioned Active Power Filter-APF of the present invention to realize that related contents such as energy reforming controlling models are introduced in detail, repeat no more here in the aforementioned techniques scheme.

What should explain at last is: above embodiment is only unrestricted in order to technical scheme of the present invention to be described; Although the present invention is specified with reference to preferred embodiment; Those of ordinary skill in the art is to be understood that; Can make amendment or be equal to replacement technical scheme of the present invention, and not break away from the spirit and the scope of technical scheme of the present invention.

Claims (2)

1. an Active Power Filter-APF is characterized in that, comprising:

The harmonic current detection module is connected with feed line, is used to gather load current, obtains the harmonic component of load current, with generating the offset current command signal after its reversed polarity;

The offset current control module; Be connected with feed line with said harmonic current detection module; Be used for exporting through energy reforming control model generation offset current and to said feed line based on said offset current command signal, said offset current is opposite with harmonic component equal and opposite in direction, the direction of load current;

Wherein, said offset current control module comprises:

Energy reforming controlling models unit is connected with said harmonic current detection module, is used to receive said offset current command signal, generates the offset current control signal according to said offset current command signal through the energy reforming controlling models;

Drive circuit is connected with said energy reforming controlling models unit, is used for said offset current control signal is amplified;

Power cell is connected with said drive circuit, is used for generating offset current by said driving circuit drives and exports the harmonic component equal and opposite in direction of said offset current and load current, in the opposite direction to said feed line;

Said energy reforming controlling models is:

$\left\{\begin{array}{c}{u}_d=-4\mathrm{\&omega;L}[c_2-\frac{2c_4-R_C{E}_m^2({\mathrm{Li}}_{\mathrm{cd}}+c_3)(e^{2{\mathrm{Li}}_{\mathrm{cq}}}+1)}{(e^{2{\mathrm{Li}}_{\mathrm{cq}}}+1)(E_m{R}_C{\mathrm{Cu}}_{\mathrm{dc}}-2c_2{\mathrm{Li}}_{\mathrm{cq}}+c_1)}]\\ u_q=\mathrm{\&omega;L}\frac{E_m{R}_C{\mathrm{Cu}}_{\mathrm{dc}}-2c_2{\mathrm{Li}}_{\mathrm{cq}}+c_1}{R_C{E}_m({\mathrm{Li}}_{\mathrm{cd}}+c_3)}\end{array}\right.$

c _{I, i=1,2,3,4}The condition that satisfies is: c ₂Be any real number, c ₃＞0,

$c_1=-\frac{{\mathrm{Li}}_{\mathrm{cq}*}}{C}(2{\mathrm{Li}}_{\mathrm{cd}*}+2c_3+R_C{E}_{m}C),c_4=-\frac{c_2{\mathrm{Cu}}_{\mathrm{dc}*}}{{\mathrm{Li}}_{\mathrm{cd}*}+2c_3}+\frac{c_1{c}_2}{R_C{E}_m({\mathrm{Li}}_{\mathrm{cd}*}+2c_3)}$

Wherein, u _d, u _qBe respectively equivalent d-q axle control variables constant in the offset current control variables, L is an equivalent inductance, and C is a capacitor, R _CBe the equivalent resistance of capacitor, i _Cd, i _CqBe respectively the equivalent d-q shaft current of offset current, u _DcBe capacitor terminal voltage, E _mBe system's (electrical network) three-phase alternating current line voltage effective value,

With

Be respectively offset current command signal equivalence d-q shaft current,

Capacitor terminal voltage during for stable state.

2. an Active Power Filter-APF energy reforming control method is characterized in that, comprising:

Gather load current from feed line, obtain the harmonic component of load current, with generating the offset current command signal after its reversed polarity;

Generate offset current and export the harmonic component equal and opposite in direction of said offset current and load current, in the opposite direction through the energy reforming controlling models according to said offset current command signal to said feed line;

Wherein, comprise through energy reforming controlling models generation offset current and to said feed line output according to said offset current command signal:

Generate the offset current control signal according to said offset current command signal through the energy reforming controlling models;

Said offset current control signal is amplified back generation offset current export the harmonic component equal and opposite in direction of said offset current and load current, in the opposite direction to said feed line;

Said energy reforming controlling models is:

$\left\{\begin{array}{c}{u}_d=-4\mathrm{\&omega;L}[c_2-\frac{2c_4-R_C{E}_m^2({\mathrm{Li}}_{\mathrm{cd}}+c_3)(e^{2{\mathrm{Li}}_{\mathrm{cq}}}+1)}{(e^{2{\mathrm{Li}}_{\mathrm{cq}}}+1)(E_m{R}_C{\mathrm{Cu}}_{\mathrm{dc}}-2c_2{\mathrm{Li}}_{\mathrm{cq}}+c_1)}]\\ u_q=\mathrm{\&omega;L}\frac{E_m{R}_C{\mathrm{Cu}}_{\mathrm{dc}}-2c_2{\mathrm{Li}}_{\mathrm{cq}}+c_1}{R_C{E}_m({\mathrm{Li}}_{\mathrm{cd}}+c_3)}\end{array}\right.$

c _{I, i=1,2,3,4}The condition that satisfies is: c ₂Be any real number, c ₃＞0,

$c_1=-\frac{{\mathrm{Li}}_{\mathrm{cq}*}}{C}(2{\mathrm{Li}}_{\mathrm{cd}*}+2c_3+R_C{E}_{m}C),c_4=-\frac{c_2{\mathrm{Cu}}_{\mathrm{dc}*}}{{\mathrm{Li}}_{\mathrm{cd}*}+2c_3}+\frac{c_1{c}_2}{R_C{E}_m({\mathrm{Li}}_{\mathrm{cd}*}+2c_3)}$

Wherein, u _d, u _qBe respectively equivalent d-q axle control variables constant in the offset current control variables, L is an equivalent inductance, and C is a capacitor, R _CBe the equivalent resistance of capacitor, i _Cd, i _CqBe respectively the equivalent d-q shaft current of offset current, u _DcBe capacitor terminal voltage, E _mBe system's (electrical network) three-phase alternating current line voltage effective value,

With

Be respectively offset current command signal equivalence d-q shaft current,

Capacitor terminal voltage during for stable state.

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