CN102447267A - Control method of grid-connected inverter - Google Patents

Abstract

The invention relates to a control method of a grid-connected inverter, which comprises the following steps: calculating the positive/negative-sequence component of the vector of the voltage of a power grid and the angular speed and the vector angle of the vector of the voltage of the power grid at a moment corresponding to the sampled voltage of the power grid and the vector angle of the vector of the voltage of the power grid at a moment corresponding to sampling current, and then obtaining the feedforward item of the voltage of the power grid, which is required by the occurrence moment of pulse-width modulation (PWM), and the feedback value of active and reactive current, which is required by the closed-loop control of current. The control method of the grid-connected inverter, which is disclosed by the invention, has the advantages and the positive effects that because of being in consideration of the influence of a system to the delay of the sampling time of software and hardware for the physical quantity, the feedforward item of the voltage of the power grid, which is required by the occurrence moment of the PWM, and the feedback value of the active and reactive current, which is required by the closed-loop control of the current, are obtained, and the feedforward control accuracy of the voltage of the power grid and the decoupling control accuracy of the active and reactive current are enhanced, so that the control accuracy of active and reactive power is obviously enhanced, and the adaptive capacity under the conditions of unbalance of the voltage of the power grid and unbalance of current control is reinforced.

Description

The combining inverter control method

Technical field

The present invention relates to the electric power network technique field, particularly a kind of combining inverter control method.

Background technology

Along with the exhaustion of global warming and fossil fuel, wind power generation and photovoltaic generation more and more receive the attention of countries in the world.But along with the fast lifting of wind power generation and photovoltaic generation installed capacity, various countries also have higher requirement to the also network electric energy quality of wind power generation and photovoltaic generation.

Referring to Fig. 1; Though the double-fed unit in the wind power generation field and the net side converter of total power unit are compared with photovoltaic combining inverter; Many differences are arranged on control strategy; But the system topological figure of the two is consistent, its voltage feed-forward control control technology and meritorious, reactive current decoupling zero control technology is also just the same.Simple in order to explain, the back is referred to as the two and is combining inverter.

Referring to Fig. 2, in order to increase the current tracking characteristic, offset the influence of line voltage to current response, the conventional way of combining inverter is to adopt the control 202 of voltage feed-forward control to improve the current tracking characteristic of combining inverter at present.

Suppose that it is t constantly that PWM generates, system is τ to the delay total time of line voltage software and hardware sampling _e, then actual line voltage sampling instant is (t-τ _e).Ignore the line voltage sudden change,

The angular frequency of the positive and negative preface component of line voltage is respectively ω ⁺, ω ^-

The generation of traditional P WM pulse all is based on electrical network positive sequence dq+ rotating coordinate system orientation, and the voltage feed-forward control item can be represented with following formula.

$\left[\begin{array}{c}{e}_{d+}^{\′}\left(t\right)\\ e_{q+}^{\′}\left(t\right)\end{array}\right]=\left[\begin{array}{c}{e}_d^{+}(t-{\mathrm{\τ}}_e)\\ e_q^{+}(t-{\mathrm{\τ}}_e)\end{array}\right]+\left[\begin{array}{cc}\cos {\∫}_0^{t-{\mathrm{\τ}}_e}({\mathrm{\ω}}^{+}+{\mathrm{\ω}}^{-})\mathrm{dt}& \sin {\∫}_0^{t-{\mathrm{\τ}}_e}({\mathrm{\ω}}^{+}+{\mathrm{\ω}}^{-})\mathrm{dt}\\ -\sin {\∫}_0^{t-{\mathrm{\τ}}_e}({\mathrm{\ω}}^{+}+{\mathrm{\ω}}^{-})\mathrm{dt}& \cos {\∫}_0^{t-{\mathrm{\τ}}_e}({\mathrm{\ω}}^{+}+{\mathrm{\ω}}^{-})\mathrm{dt}\end{array}\right]\left[\begin{array}{c}{e}_d^{-}(t-{\mathrm{\τ}}_e)\\ e_q^{-}(t-{\mathrm{\τ}}_e)\end{array}\right](t>{\mathrm{\τ}}_e)$

Here for ease of distinguishing ,+,-positive sequence and the negative sequence component of interval scale respective physical amount in the upper right corner, d, the q axle component of representing the respective physical amount under positive sequence dq+ rotating coordinate system and negative phase-sequence dq-rotating coordinate system, to obtain respectively at lower right corner Shi Ze.

And corresponding t real voltage feed-forward control item constantly should for:

$\left[\begin{array}{c}{e}_{d+}\left(t\right)\\ e_{q+}\left(t\right)\end{array}\right]=\left[\begin{array}{c}{e}_d^{+}\left(t\right)\\ e_q^{+}\left(t\right)\end{array}\right]+\left[\begin{array}{cc}\cos {\∫}_0^t({\mathrm{\ω}}^{+}+{\mathrm{\ω}}^{-})\mathrm{dt}& \sin {\∫}_0^t({\mathrm{\ω}}^{+}+{\mathrm{\ω}}^{-})\mathrm{dt}\\ -\sin {\∫}_0^t({\mathrm{\ω}}^{+}+{\mathrm{\ω}}^{-})\mathrm{dt}& \cos {\∫}_0^t({\mathrm{\ω}}^{+}+{\mathrm{\ω}}^{-})\mathrm{dt}\end{array}\right]\left[\begin{array}{c}{e}_d^{-}\left(t\right)\\ e_q^{-}\left(t\right)\end{array}\right]$

If there is imbalance to a certain degree in line voltage, promptly

The time, when time of delay of software and hardware sampling line voltage hour, can be similar to and think [e _D+(t), e _Q+(t)] ^T≈ [e ' _D+(t), e ' _Q+(t)] ^T, but as the delay in sampling time of hardware and software greatly time the, [e _D+(t), e _Q+(t)] ^T≠ [e ' _D+(t), e ' _Q+(t)] ^T, this just causes the uneven and concussion of Current Control.

In like manner, system is τ to the delay total time of electric current software and hardware sampling _i, ignore the influence of current imbalance, classical control system can be represented with following formula with meritorious, reactive current value of feedback:

$\left[\begin{array}{c}{i}_{d+}^{\′}\left(t\right)\\ i_{q+}^{\′}\left(t\right)\end{array}\right]=\frac{2}{3}\left[\begin{array}{ccc}\cos {\∫}_0^{t-{\mathrm{\τ}}_e}{\mathrm{\ω}}^{+}\mathrm{dt}& \cos ({\∫}_0^{t-{\mathrm{\τ}}_e}{\mathrm{\ω}}^{+}\mathrm{dt}-\frac{2\mathrm{\π}}{3})& \cos ({\∫}_0^{t-{\mathrm{\τ}}_e}{\mathrm{\ω}}^{+}\mathrm{dt}+\frac{2\mathrm{\π}}{3})\\ -\sin {\∫}_0^{t-{\mathrm{\τ}}_e}{\mathrm{\ω}}^{+}\mathrm{dt}& -\sin ({\∫}_0^{t-{\mathrm{\τ}}_e}{\mathrm{\ω}}^{+}\mathrm{dt}-\frac{2\mathrm{\π}}{3})& -\sin ({\∫}_0^{t-{\mathrm{\τ}}_e}{\mathrm{\ω}}^{+}\mathrm{dt}+\frac{2\mathrm{\π}}{3})\end{array}\right]\left[\begin{array}{c}{i}_A(t-{\mathrm{\τ}}_i)\\ i_B(t-{\mathrm{\τ}}_i)\\ i_C(t-{\mathrm{\τ}}_i)\end{array}\right]\left(\begin{array}{c}t>{\mathrm{\τ}}_i\\ t>{\mathrm{\τ}}_e\end{array}\right)$

Referring to Fig. 2, because τ in most cases _i≠ τ _e, will certainly cause the inaccurate of active current and reactive current decoupling zero control 201.

In sum, the software and hardware sampling time of line voltage and electric current postpones to be prone to cause the uneven and vibration of Current Control, and active current and reactive current decoupling zero control is inaccurate.

Summary of the invention

The objective of the invention is to overcome above-mentioned defective; Provide a kind of and can improve voltage feed-forward control precise control property; Strengthen the degree of balance of Current Control; And improve meritorious, reactive current decoupling zero control precision, thereby improve combining inverter electrical network adaptive capacity and combining inverter control method meritorious, the Reactive Power Control precision.

For achieving the above object, combining inverter control method provided by the invention comprises voltage feed-forward control control, and this method comprises:

Step 1, in current control cycle, the sampling line voltage;

Step 2, the line voltage value of utilizing current control cycle to sample calculates the interior line voltage of this control cycle at (t-τ _e) corresponding constantly line voltage positive-negative sequence component

And line voltage positive-negative sequence azimuth speed omega ⁺, ω ^-And next control cycle line voltage is at (t-τ _e) constantly electric network positive and negative preface vector angle

Step 3 goes out PWM through computes the current control cycle voltage feed-forward control compensation term that the moment needs takes place:

$\left[\begin{array}{c}{e}_{d+}\left(t\right)\\ e_{q+}\left(t\right)\end{array}\right]=\left[\begin{array}{c}{e}_d^{+}(t-{\mathrm{\τ}}_e)\\ e_q^{+}(t-{\mathrm{\τ}}_e)\end{array}\right]+\left[\begin{array}{cc}\cos [\mathrm{\Δ}{\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}+({\mathrm{\ω}}^{+}+{\mathrm{\ω}}^{-}){\mathrm{\τ}}_e]& \sin [\mathrm{\Δ}{\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}+({\mathrm{\ω}}^{+}+{\mathrm{\ω}}^{-}){\mathrm{\τ}}_e]\\ -\sin [\mathrm{\Δ}{\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}+({\mathrm{\ω}}^{+}+{\mathrm{\ω}}^{-}){\mathrm{\τ}}_e]& \cos [\mathrm{\Δ}{\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}+({\mathrm{\ω}}^{+}+{\mathrm{\ω}}^{-}){\mathrm{\τ}}_e]\end{array}\right]\left[\begin{array}{c}{e}_d^{-}(t-{\mathrm{\τ}}_e)\\ e_q^{-}(t-{\mathrm{\τ}}_e)\end{array}\right]$

Wherein, $\mathrm{\Δ}{\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}={\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}^{+}-{\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}^{-};$

Step 4 in current control cycle, is used for voltage feed-forward control compensation control with the aforementioned voltage feed-forward control item that calculates.

Further, in said step 2, comprise that the three-phase voltage value with sampling obtains the vector [e under the two phase rest frames through the Clarke conversion respectively _α(t-τ _e) e _β(t-τ _e)] ^TThen respectively with angle

Do the Park conversion, obtain based on line voltage vector [e in the synchronous dq+ rotating coordinate system of positive sequence _D+(t-τ _e) e _Q+(t-τ _e)] ^TAnd based on voltage vector [e in the synchronous dq-rotating coordinate system of negative phase-sequence _d-(t-τ _e) e _q-(t-τ _e)] ^T, wherein, Clarke and Park transformation matrix are respectively:

$C_{3/2}=\frac{2}{3}\left[\begin{array}{ccc}1& -1/2& -1/2\\ 0& \sqrt{3}/2& -\sqrt{3}/2\end{array}\right],$

Obtain the line voltage positive-negative sequence component in this control cycle at last With line voltage positive-negative sequence azimuth speed omega ⁺, ω ^-And next control cycle line voltage is at (t-τ _e) constantly electric network positive and negative preface vector angle

Wherein, calculate, can make ω for convenient ^-=ω ⁺,

Adopt above-mentioned control method can improve voltage feed-forward control precise control property, strengthen the degree of balance of Current Control, thereby improve combining inverter electrical network adaptive capacity.

For achieving the above object, second kind of combining inverter control method provided by the invention comprises electric network active electric current and reactive current decoupling zero control, and this method comprises:

Step 1, in current control cycle, sampling line voltage and power network current;

Step 2 utilizes current control cycle with the line voltage value that samples, and calculates the interior line voltage of this control cycle at (t-τ _e) corresponding constantly line voltage positive-negative sequence component

And line voltage positive-negative sequence azimuth speed omega ⁺, ω ^-And next control cycle line voltage is at (t-τ _e) constantly electric network positive and negative preface vector angle

With line voltage at (t-τ _i) constantly electrical network positive sequence vector angle

Step 3 goes out meritorious, the idle component of electric current that current control cycle is used to control through computes:

$\left[\begin{array}{c}{i}_{d+}\left(t\right)\\ i_{q+}\left(t\right)\end{array}\right]=\frac{2}{3}\left[\begin{array}{ccc}\cos {\mathrm{\θ}}_{t-{\mathrm{\τ}}_i}^{+}& \cos ({\mathrm{\θ}}_{t-{\mathrm{\τ}}_i}^{+}-\frac{2\mathrm{\π}}{3})& \cos ({\mathrm{\θ}}_{t-{\mathrm{\τ}}_i}^{+}+\frac{2\mathrm{\π}}{3})\\ -\sin {\mathrm{\θ}}_{t-{\mathrm{\τ}}_i}^{+}& -\sin ({\mathrm{\θ}}_{t-{\mathrm{\τ}}_i}^{+}-\frac{2\mathrm{\π}}{3})& -\sin ({\mathrm{\θ}}_{t-{\mathrm{\τ}}_i}^{+}+\frac{2\mathrm{\π}}{3})\end{array}\right]\left[\begin{array}{c}{i}_A(t-{\mathrm{\τ}}_i)\\ i_B(t-{\mathrm{\τ}}_i)\\ i_C(t-{\mathrm{\τ}}_i)\end{array}\right];$

Step 4 is in current control cycle, with the current closed-loop control that the aforementioned electric current that calculates is meritorious, idle component is used for system.

Adopt above-mentioned control method, can improve meritorious, reactive current decoupling zero control precision, thereby improve control precision meritorious, reactive power.

For achieving the above object, the third combining inverter control method provided by the invention comprises electric network active electric current and reactive current decoupling zero control, voltage feed-forward control control, and this method comprises:

Step 1, in current control cycle, sampling line voltage and power network current;

Step 2 utilizes current control cycle with the line voltage value that samples, and calculates the interior line voltage of this control cycle at (t-τ _e) corresponding constantly line voltage positive-negative sequence component

And line voltage positive-negative sequence azimuth speed omega ⁺, ω ^-And next control cycle line voltage is at (t-τ _e) constantly electric network positive and negative preface vector angle

With line voltage at (t-τ _i) constantly electrical network positive sequence vector angle

Step 3 goes out PWM through computes the current control cycle voltage feed-forward control compensation term that the moment needs takes place:

$\left[\begin{array}{c}{e}_{d+}\left(t\right)\\ e_{q+}\left(t\right)\end{array}\right]=\left[\begin{array}{c}{e}_d^{+}(t-{\mathrm{\τ}}_e)\\ e_q^{+}(t-{\mathrm{\τ}}_e)\end{array}\right]+\left[\begin{array}{cc}\cos [\mathrm{\Δ}{\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}+({\mathrm{\ω}}^{+}+{\mathrm{\ω}}^{-}){\mathrm{\τ}}_e]& \sin [\mathrm{\Δ}{\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}+({\mathrm{\ω}}^{+}+{\mathrm{\ω}}^{-}){\mathrm{\τ}}_e]\\ -\sin [\mathrm{\Δ}{\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}+({\mathrm{\ω}}^{+}+{\mathrm{\ω}}^{-}){\mathrm{\τ}}_e]& \cos [\mathrm{\Δ}{\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}+({\mathrm{\ω}}^{+}+{\mathrm{\ω}}^{-}){\mathrm{\τ}}_e]\end{array}\right]\left[\begin{array}{c}{e}_d^{-}(t-{\mathrm{\τ}}_e)\\ e_q^{-}(t-{\mathrm{\τ}}_e)\end{array}\right]$

Wherein, $\mathrm{\Δ}{\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}={\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}^{+}-{\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}^{-};$

Step 4 goes out meritorious, the idle component of electric current that current control cycle is used to control through computes:

$\left[\begin{array}{c}{i}_{d+}\left(t\right)\\ i_{q+}\left(t\right)\end{array}\right]=\frac{2}{3}\left[\begin{array}{ccc}\cos {\mathrm{\θ}}_{t-{\mathrm{\τ}}_i}^{+}& \cos ({\mathrm{\θ}}_{t-{\mathrm{\τ}}_i}^{+}-\frac{2\mathrm{\π}}{3})& \cos ({\mathrm{\θ}}_{t-{\mathrm{\τ}}_i}^{+}+\frac{2\mathrm{\π}}{3})\\ -\sin {\mathrm{\θ}}_{t-{\mathrm{\τ}}_i}^{+}& -\sin ({\mathrm{\θ}}_{t-{\mathrm{\τ}}_i}^{+}-\frac{2\mathrm{\π}}{3})& -\sin ({\mathrm{\θ}}_{t-{\mathrm{\τ}}_i}^{+}+\frac{2\mathrm{\π}}{3})\end{array}\right]\left[\begin{array}{c}{i}_A(t-{\mathrm{\τ}}_i)\\ i_B(t-{\mathrm{\τ}}_i)\\ i_C(t-{\mathrm{\τ}}_i)\end{array}\right];$

Step 5 in current control cycle, is used for voltage feed-forward control compensation control with the aforementioned voltage feed-forward control item that calculates, and the current closed-loop that the electric current that calculates is meritorious, idle component is used for system control.

Adopt above-mentioned control method both can improve voltage feed-forward control precise control property; Strengthen the degree of balance of Current Control; Meritorious, reactive current decoupling zero control precision be can improve again, thereby combining inverter electrical network adaptive capacity and control precision meritorious, reactive power improved.

For achieving the above object, the 4th kind of combining inverter control method provided by the invention comprises electric network active electric current and reactive current decoupling zero control, voltage feed-forward control control, and this method comprises:

Step 1, in current control cycle, sampling line voltage and power network current;

Step 2 utilizes current control cycle with the line voltage value that samples, and calculates the interior line voltage of this control cycle at (t-τ _e) corresponding constantly line voltage positive-negative sequence component

And line voltage positive-negative sequence azimuth speed omega ⁺, ω ^-And next control cycle line voltage is at (t-τ _e) constantly electric network positive and negative preface vector angle

With line voltage at (t-τ _i) constantly electrical network positive sequence vector angle

Step 3 goes out PWM through computes the current control cycle voltage feed-forward control compensation term that the moment needs takes place:

$\left[\begin{array}{c}{e}_{d+}\left(t\right)\\ e_{q+}\left(t\right)\end{array}\right]=\left[\begin{array}{c}{e}_d^{+}(t-{\mathrm{\τ}}_e)\\ e_q^{+}(t-{\mathrm{\τ}}_e)\end{array}\right]+\left[\begin{array}{cc}\cos [\mathrm{\Δ}{\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}+({\mathrm{\ω}}^{+}+{\mathrm{\ω}}^{-}){\mathrm{\τ}}_e]& \sin [\mathrm{\Δ}{\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}+({\mathrm{\ω}}^{+}+{\mathrm{\ω}}^{-}){\mathrm{\τ}}_e]\\ -\sin [\mathrm{\Δ}{\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}+({\mathrm{\ω}}^{+}+{\mathrm{\ω}}^{-}){\mathrm{\τ}}_e]& \cos [\mathrm{\Δ}{\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}+({\mathrm{\ω}}^{+}+{\mathrm{\ω}}^{-}){\mathrm{\τ}}_e]\end{array}\right]\left[\begin{array}{c}{e}_d^{-}(t-{\mathrm{\τ}}_e)\\ e_q^{-}(t-{\mathrm{\τ}}_e)\end{array}\right]$

Wherein, $\mathrm{\Δ}{\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}={\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}^{+}-{\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}^{-};$

Step 4 goes out meritorious, the idle component of electric current that current control cycle is used to control through computes:

$\left[\begin{array}{c}{i}_{d+}\left(t\right)\\ i_{q+}\left(t\right)\end{array}\right]=\frac{2}{3}\left[\begin{array}{ccc}\cos {\mathrm{\θ}}_{t-{\mathrm{\τ}}_i}^{+}& \cos ({\mathrm{\θ}}_{t-{\mathrm{\τ}}_i}^{+}-\frac{2\mathrm{\π}}{3})& \cos ({\mathrm{\θ}}_{t-{\mathrm{\τ}}_i}^{+}+\frac{2\mathrm{\π}}{3})\\ -\sin {\mathrm{\θ}}_{t-{\mathrm{\τ}}_i}^{+}& -\sin ({\mathrm{\θ}}_{t-{\mathrm{\τ}}_i}^{+}-\frac{2\mathrm{\π}}{3})& -\sin ({\mathrm{\θ}}_{t-{\mathrm{\τ}}_i}^{+}+\frac{2\mathrm{\π}}{3})\end{array}\right]\left[\begin{array}{c}{i}_A(t-{\mathrm{\τ}}_i)\\ i_B(t-{\mathrm{\τ}}_i)\\ i_C(t-{\mathrm{\τ}}_i)\end{array}\right];$

Step 5 in current control cycle, is used for voltage feed-forward control compensation control with the aforementioned voltage feed-forward control item that calculates, and the current closed-loop that the electric current that calculates is meritorious, idle component is used for system control;

At last, with output, the reactive current cross decoupling item-ω of active current adjuster ⁺Li _Q+(t) and voltage feed-forward control item e _D+(t) synthetic jointly v _d(t); Output, active current cross decoupling item ω with the reactive current adjuster ⁺Li _D+(t) and voltage feed-forward control item e _Q+(t) synthetic jointly v _q(t); Again with v _q(t) and v _d(t) with PWM corresponding constantly line voltage azimuth taking place does the PARK inverse transformation and obtains the reference voltage vector v under the two phase rest frames that current control cycle PWM generating module needs _α(t), v _β(t); Wherein the PARK inverse-transform matrix is:

Further, the corresponding constantly line voltage azimuth of described PWM generation is

Adopt above-mentioned control method both can improve voltage feed-forward control precise control property; Strengthen the degree of balance of Current Control; Can improve meritorious, reactive current decoupling zero control precision again; Thereby improve combining inverter electrical network adaptive capacity and control precision meritorious, reactive power, and further improved the PWM control precision.

Above-mentioned second kind to the 4th kind three kinds of combining inverter control methods of the present invention wherein in said step 2, comprise that the three-phase voltage value with sampling obtains the vector [e under the two phase rest frames through the Clarke conversion respectively _α(t-τ _e) e _β(t-τ _e)] ^TThen respectively with angle

Do the Park conversion, obtain based on line voltage vector [e in the synchronous dq+ rotating coordinate system of positive sequence _D+(t-τ _e) e _Q+(t-τ _e)] ^TAnd based on voltage vector [e in the synchronous dq-rotating coordinate system of negative phase-sequence _D-(t-τ _e) e _Q-(t-τ _e)] ^T, wherein, Clarke and Park transformation matrix are respectively:

$C_{3/2}=\frac{2}{3}\left[\begin{array}{ccc}1& -1/2& -1/2\\ 0& \sqrt{3}/2& -\sqrt{3}/2\end{array}\right],$

Obtain the line voltage positive-negative sequence component in this control cycle at last

With line voltage positive-negative sequence azimuth speed omega ⁺, ω ^-And the electric network positive and negative preface vector angle of next control cycle

Wherein, calculate, can make ω for convenient ^-=ω ⁺,

${\mathrm{\θ}}_{t-{\mathrm{\τ}}_i}^{+}={\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}^{+}+{\mathrm{\ω}}^{+}({\mathrm{\τ}}_e-{\mathrm{\τ}}_i).$

The advantage and the good effect of combining inverter control method of the present invention are: owing to consider the influence of system to the delay in physical quantity software and hardware sampling time; Obtained the value of feedback that needed meritorious, the reactive current of needed voltage feed-forward control item and current closed-loop control constantly takes place PWM; Improve voltage feed-forward control precise control property; Strengthen the degree of balance of Current Control; Improve meritorious, reactive current decoupling zero control precision, thereby obviously strengthened the adaptive capacity under the unbalanced source voltage condition and improved control precision meritorious, reactive power.

To combine embodiment to be elaborated below with reference to accompanying drawing.

Description of drawings

Fig. 1 is the topological diagram of combining inverter circuit;

Fig. 2 is the block diagram of combining inverter electric network active electric current, reactive current decoupling zero control and voltage feed-forward control control;

Fig. 3 is based on the block diagram of the decoupling zero control of electric network positive and negative preface and the phase-locked loop control of two coordinate transforms;

Fig. 4 is based on the block diagram of the decoupling zero control of electric network positive and negative preface and the phase-locked loop control of trapper;

Fig. 5 is the block diagram of combining inverter control method of the present invention.

Embodiment

Scheme provided by the invention is considered the time delay of system to line voltage and the sampling of electric current software and hardware; At first calculate the line voltage that samples positive-negative sequence component, line voltage positive-negative sequence azimuth speed and azimuth and the positive sequence azimuth that samples the line voltage in the corresponding moment of sample rate current institute of corresponding line voltage vector constantly; Obtain PWM then respectively needed voltage feed-forward control item constantly takes place; Corresponding constantly line voltage azimuth takes place with PWM and does the PARK inverse transformation and obtain the reference voltage vector under the two phase rest frames that the PWM generating module needs in the value of feedback of needed meritorious, the reactive current of current closed-loop control more at last.

For ease of the statement embodiments of the invention, a kind of decoupling zero of line voltage positive-negative sequence and the lock control mutually that can decompose line voltage positive-negative sequence component and catch the line voltage vector angle of first brief account based on positive and negative preface dq coordinate transform.

For wire system in not having, owing to can not form zero-sequence component, the voltage that does not therefore have the center line three-phase system can resolve into fundamental positive sequence and first-harmonic negative sequence component under rest frame, that is:

In the synchronous dq+ rotating coordinate system based on positive sequence, voltage vector can be expressed as:

And in the synchronous dq-rotating coordinate system based on negative phase-sequence, voltage vector can be expressed as again:

Be rewritten into above-mentioned two formulas are approximate respectively:

With reference to Fig. 3; In according to the phase-locked loop control principle block diagram of above-mentioned two formulas based on two coordinate transforms;

and

is respectively positive-negative sequence electrical network d, the q axle transient component after the decoupling zero,

and

be respectively the positive-negative sequence electrical network d after the decoupling zero, the instantaneous mean value of q axle component.

Be a kind of method of disclosed positive-negative sequence decoupling zero above, also be fit to have the system of center line,,, also can not produce zero-sequence current even the residual voltage part of voltage feed-forward control item is inaccurate because residual voltage can not produce electric current.

Specify the operation principle and the process of one embodiment of the present of invention below in conjunction with accompanying drawing, other embodiment principle is approximate therewith, is not just giving unnecessary details here.

In the embodiment of combining inverter control method of the present invention; According to the time of delay of hardware handles circuit and the time of delay of software sampling, calculate earlier with respect to PWM and t hardware handles circuit and software sampling take place constantly constant τ time of delay of line voltage sampling and current sample _e, τ _iThe supposition line voltage is at (t-τ earlier _e) corresponding constantly

Line voltage is at (t-τ _i) constantly electrical network positive sequence vector angle

Initial value is 0, line voltage positive-negative sequence azimuth speed omega ⁺And ω ^-Initial value be 100 π.

With reference to Fig. 4, combining inverter control method of the present invention comprises:

Step S11, in current control cycle, sampling line voltage and power network current.

Step S12 in current control cycle, utilizes the line voltage value that samples, and calculates the interior line voltage of current control cycle at (t-τ _e) corresponding constantly line voltage positive-negative sequence component

And line voltage positive-negative sequence azimuth speed omega ⁺, ω ^-And next control cycle line voltage is at (t-τ _e) constantly electric network positive and negative preface vector angle With line voltage at (t-τ _i) constantly electrical network positive sequence vector angle

Concrete, the three-phase voltage value of sampling is obtained the vector [e under the two phase rest frames through the Clarke conversion respectively _α(t-τ _e) e _β(t-τ _e)] ^TThen respectively with angle

Do the Park conversion, obtain based on line voltage vector [e in the synchronous dq+ rotating coordinate system of positive sequence _D+(t-τ _e) e _Q+(t-τ _e)] ^TAnd based on voltage vector [e in the synchronous dq-rotating coordinate system of negative phase-sequence _D-(t-τ _e) e _Q-(t-τ _e)] ^T, wherein, Clarke, Park transformation matrix are respectively:

$C_{3/2}=\frac{2}{3}\left[\begin{array}{ccc}1& -1/2& -1/2\\ 0& \sqrt{3}/2& -\sqrt{3}/2\end{array}\right],$

Then, in conjunction with reference to Fig. 3,, obtain the line voltage positive-negative sequence component in this control cycle through aforementioned electric network positive and negative preface decoupling zero control 301 and phase-locked loop control 302 based on two coordinate transforms

With line voltage positive-negative sequence azimuth speed omega ⁺, ω ^-And next control cycle line voltage is at (t-τ _e) constantly electric network positive and negative preface vector angle Wherein, calculate, can make ω for convenient ^-=ω ⁺,

${\mathrm{\θ}}_{t-{\mathrm{\τ}}_i}^{+}={\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}^{+}+{\mathrm{\ω}}^{+}({\mathrm{\τ}}_e-{\mathrm{\τ}}_i).$

Step S13 in current control cycle, utilizes aforesaid line voltage positive-negative sequence component

And electric network positive and negative preface vector angle

With line voltage positive-negative sequence azimuth speed omega ⁺, ω ^-Calculate PWM and generate voltage feed-forward control item constantly.

Concrete, go out current control control cycle PWM through computes and generate voltage feed-forward control item constantly:

$\left[\begin{array}{c}{e}_{d+}\left(t\right)\\ e_{q+}\left(t\right)\end{array}\right]=\left[\begin{array}{c}{e}_d^{+}(t-{\mathrm{\τ}}_e)\\ e_q^{+}(t-{\mathrm{\τ}}_e)\end{array}\right]+\left[\begin{array}{cc}\cos [\mathrm{\Δ}{\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}+({\mathrm{\ω}}^{+}+{\mathrm{\ω}}^{-}){\mathrm{\τ}}_e]& \sin [\mathrm{\Δ}{\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}+({\mathrm{\ω}}^{+}+{\mathrm{\ω}}^{-}){\mathrm{\τ}}_e]\\ -\sin [\mathrm{\Δ}{\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}+({\mathrm{\ω}}^{+}+{\mathrm{\ω}}^{-}){\mathrm{\τ}}_e]& \cos [\mathrm{\Δ}{\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}+({\mathrm{\ω}}^{+}+{\mathrm{\ω}}^{-}){\mathrm{\τ}}_e]\end{array}\right]\left[\begin{array}{c}{e}_d^{-}(t-{\mathrm{\τ}}_e)\\ e_q^{-}(t-{\mathrm{\τ}}_e)\end{array}\right]$

Step S14 in current control cycle, utilizes aforesaid current sampling data i _A(t-τ _i), i _B(t-τ _i), i _C(t-τ _i) and the electric current that samples corresponding electric network positive and negative preface vector angle constantly

Calculate meritorious, the idle component of electric current, thereby be used for meritorious, the idle decoupling zero control of electric current.

Concrete, go out meritorious, the idle component of current control control cycle sample rate current value through computes:

$\left[\begin{array}{c}{i}_{d+}\left(t\right)\\ i_{q+}\left(t\right)\end{array}\right]=\frac{2}{3}\left[\begin{array}{ccc}\cos {\mathrm{\θ}}_{t-{\mathrm{\τ}}_i}^{+}& \cos ({\mathrm{\θ}}_{t-{\mathrm{\τ}}_i}^{+}-\frac{2\mathrm{\π}}{3})& \cos ({\mathrm{\θ}}_{t-{\mathrm{\τ}}_i}^{+}+\frac{2\mathrm{\π}}{3})\\ -\sin {\mathrm{\θ}}_{t-{\mathrm{\τ}}_i}^{+}& -\sin ({\mathrm{\θ}}_{t-{\mathrm{\τ}}_i}^{+}-\frac{2\mathrm{\π}}{3})& -\sin ({\mathrm{\θ}}_{t-{\mathrm{\τ}}_i}^{+}+\frac{2\mathrm{\π}}{3})\end{array}\right]\left[\begin{array}{c}{i}_A(t-{\mathrm{\τ}}_i)\\ i_B(t-{\mathrm{\τ}}_i)\\ i_C(t-{\mathrm{\τ}}_i)\end{array}\right]$

Step S15 in current control cycle, the aforementioned voltage feed-forward control item that calculates is used for voltage feed-forward control compensation control, and the electric current that calculates is meritorious, idle component is done the current closed-loop control that system is used for system.

Concrete, the electric current that calculates is meritorious, idle component i _D+(t), i _Q+(t) feedback term of controlling as meritorious reactive current decoupling zero in the current control cycle.

Wherein, the reference value of reactive current closed-loop control

Need be by corresponding combining inverter to the reactive power decision of electrical network output, promptly

E (t-τ _e) the electrical network effective value that samples for current control cycle, Q is for needing the reactive power of output; To photovoltaic DC-to-AC converter, the reference value of active current closed-loop control

There is corresponding M PPT algorithm to obtain, and to wind energy converter net side converter, the reference value of active current closed-loop control

Output by dc voltage outer shroud adjuster obtains.

In conjunction with reference to Fig. 3, again with output, the reactive current cross decoupling item-ω of active current adjuster ⁺Li _Q+(t), reach voltage feed-forward control item e _D+(t) synthetic jointly current control cycle PWM generating module need based on the vector v under the positive and negative preface dq coordinate _d(t); The output of reactive current adjuster, active current cross decoupling item ω ⁺Li _D+(t), reach voltage feed-forward control item e _Q+(t) synthetic jointly current control cycle PWM generating module need based on the vector v under the positive and negative preface dq coordinate _q(t).Wherein, reactive current cross decoupling item-ω ⁺Li _Q+(t) and active current cross decoupling item ω ⁺Li _D+(t) be meant the component of inductive drop, be the common practise of this area, just do not do here and give unnecessary details at the DQ axle.

At last, with current control cycle PWM generating module need based on the vector v under the positive and negative preface dq coordinate _q(t) and v _d(t) with angle Do the PARK inverse transformation, obtain the reference voltage vector v under the two phase rest frames that current control cycle PWM generating module needs _α(t) and v _β(t).Wherein, the PARK inverse-transform matrix is:

Embodiment recited above describes preferred implementation of the present invention, rather than whole embodiment, is not that design of the present invention and scope are limited.Especially this patent relate to based on the electric network positive and negative preface decoupling zero control of two coordinate transforms and Phase Lock Technique control, can substitute the PHASE-LOCKED LOOP PLL TECHNIQUE control based on trapper for example shown in Figure 4 with other relevant electric network positive and negative preface decoupling zeros and phase-locked loop control.Based on the embodiment among the present invention, all belong to the scope of the present invention's protection.Do not breaking away under the design prerequisite of the present invention; Common engineers and technicians make technical scheme of the present invention in this area various modification and improvement; The every other embodiment that does not make creative work and obtained; All should fall into protection scope of the present invention, the technology contents that the present invention asks for protection all is documented in claims.

Claims (9)

1. a combining inverter control method comprises voltage feed-forward control control (202), and this method comprises:

Step 1 (S11), in current control cycle, the sampling line voltage;

Step 2 (S12), the line voltage value of utilizing current control cycle to sample calculates the interior line voltage of this control cycle at (t-τ _e) corresponding constantly line voltage positive-negative sequence component

And line voltage positive-negative sequence azimuth speed omega ⁺, ω ^-And next control cycle line voltage is at (t-τ _e) constantly electric network positive and negative preface vector angle

Step 3 (S13) goes out PWM through computes the current control cycle voltage feed-forward control compensation term that the moment needs takes place:

$\left[\begin{array}{c}{e}_{d+}\left(t\right)\\ e_{q+}\left(t\right)\end{array}\right]=\left[\begin{array}{c}{e}_d^{+}(t-{\mathrm{\τ}}_e)\\ e_q^{+}(t-{\mathrm{\τ}}_e)\end{array}\right]+\left[\begin{array}{cc}\cos [\mathrm{\Δ}{\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}+({\mathrm{\ω}}^{+}+{\mathrm{\ω}}^{-}){\mathrm{\τ}}_e]& \sin [\mathrm{\Δ}{\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}+({\mathrm{\ω}}^{+}+{\mathrm{\ω}}^{-}){\mathrm{\τ}}_e]\\ -\sin [\mathrm{\Δ}{\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}+({\mathrm{\ω}}^{+}+{\mathrm{\ω}}^{-}){\mathrm{\τ}}_e]& \cos [\mathrm{\Δ}{\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}+({\mathrm{\ω}}^{+}+{\mathrm{\ω}}^{-}){\mathrm{\τ}}_e]\end{array}\right]\left[\begin{array}{c}{e}_d^{-}(t-{\mathrm{\τ}}_e)\\ e_q^{-}(t-{\mathrm{\τ}}_e)\end{array}\right]$

Wherein, $\mathrm{\Δ}{\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}={\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}^{+}-{\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}^{-};$

Step 4 (S15) in current control cycle, is used for voltage feed-forward control compensation control with the aforementioned voltage feed-forward control item that calculates.

2. combining inverter control method according to claim 1 is characterized in that: wherein in said step 2 (S12), comprise that the three-phase voltage value with sampling obtains the vector [e under the two phase rest frames through the Clarke conversion respectively _α(t-τ _e) e _β(t-τ _e)] ^TThen respectively with angle

Do the Park conversion, obtain based on line voltage vector [e in the synchronous dq+ rotating coordinate system of positive sequence _D+(t-τ _e) e _Q+(t-τ _e)] ^TAnd based on voltage vector [e in the synchronous dq-rotating coordinate system of negative phase-sequence _D-(t-τ _e) e _Q-(t-τ _e)] ^T, wherein, Clarke and Park transformation matrix are respectively:

$C_{3/2}=\frac{2}{3}\left[\begin{array}{ccc}1& -1/2& -1/2\\ 0& \sqrt{3}/2& -\sqrt{3}/2\end{array}\right],$

Obtain the line voltage positive-negative sequence component in this control cycle at last

With line voltage positive-negative sequence azimuth speed omega ⁺, ω ^-And the electric network positive and negative preface vector angle of next control cycle

Wherein, ${\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}^{+}={\∫}_0^t{\mathrm{\ω}}^{+}\mathrm{Dt},$ ${\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}^{-}=-{\∫}_0^t{\mathrm{\ω}}^{-}\mathrm{Dt}.$

3. a combining inverter control method comprises electric network active electric current and reactive current decoupling zero control (201), and this method comprises:

Step 1 (S11), in current control cycle, sampling line voltage and power network current;

Step 2 (S12) utilizes current control cycle with the line voltage value that samples, and calculates the interior line voltage of this control cycle at (t-τ _e) corresponding constantly line voltage positive sequence component And line voltage positive-negative sequence azimuth speed omega ⁺, ω ^-And next control cycle line voltage is at (t-τ _e) constantly electric network positive and negative preface vector angle

With line voltage at (t-τ _i) constantly electrical network positive sequence vector angle

Step 3 (S14) goes out meritorious, the idle component of electric current that current control cycle is used to control through computes:

$\left[\begin{array}{c}{i}_{d+}\left(t\right)\\ i_{q+}\left(t\right)\end{array}\right]=\frac{2}{3}\left[\begin{array}{ccc}\cos {\mathrm{\θ}}_{t-{\mathrm{\τ}}_i}^{+}& \cos ({\mathrm{\θ}}_{t-{\mathrm{\τ}}_i}^{+}-\frac{2\mathrm{\π}}{3})& \cos ({\mathrm{\θ}}_{t-{\mathrm{\τ}}_i}^{+}+\frac{2\mathrm{\π}}{3})\\ -\sin {\mathrm{\θ}}_{t-{\mathrm{\τ}}_i}^{+}& -\sin ({\mathrm{\θ}}_{t-{\mathrm{\τ}}_i}^{+}-\frac{2\mathrm{\π}}{3})& -\sin ({\mathrm{\θ}}_{t-{\mathrm{\τ}}_i}^{+}+\frac{2\mathrm{\π}}{3})\end{array}\right]\left[\begin{array}{c}{i}_A(t-{\mathrm{\τ}}_i)\\ i_B(t-{\mathrm{\τ}}_i)\\ i_C(t-{\mathrm{\τ}}_i)\end{array}\right];$

Step 4 (S15) is in current control cycle, with the current closed-loop control that the aforementioned electric current that calculates is meritorious, idle component is used for system.

4. combining inverter control method according to claim 3 is characterized in that: wherein in said step 2 (S12), comprise that the three-phase voltage value with sampling obtains the vector [e under the two phase rest frames through the Clarke conversion respectively _α(t-τ _e) e _β(t-τ _e)] ^TThen respectively with angle

Do the Park conversion, obtain based on line voltage vector [e in the synchronous dq+ rotating coordinate system of positive sequence _D+(t-τ _e) e _Q+(t-τ _e)] ^TAnd based on voltage vector [e in the synchronous dq-rotating coordinate system of negative phase-sequence _D-(t-τ _e) e _Q-(t-τ _e)] ^T, wherein, Clarke and Park transformation matrix are respectively:

$C_{3/2}=\frac{2}{3}\left[\begin{array}{ccc}1& -1/2& -1/2\\ 0& \sqrt{3}/2& -\sqrt{3}/2\end{array}\right],$

Obtain the line voltage positive-negative sequence component in this control cycle at last

With line voltage positive-negative sequence azimuth speed omega ⁺, ω ^-And the electric network positive and negative preface vector angle of next control cycle

Wherein, ${\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}^{+}={\∫}_0^t{\mathrm{\ω}}^{+}\mathrm{Dt},$ ${\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}^{-}=-{\∫}_0^t{\mathrm{\ω}}^{-}\mathrm{Dt},$ ${\mathrm{\θ}}_{t-{\mathrm{\τ}}_i}^{+}={\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}^{+}+{\mathrm{\ω}}^{+}({\mathrm{\τ}}_e-{\mathrm{\τ}}_i).$

5. a combining inverter control method comprises electric network active electric current and reactive current decoupling zero control (201), voltage feed-forward control control (202), and this method comprises:

Step 1 (S11), in current control cycle, sampling line voltage and power network current;

Step 2 (S12) utilizes current control cycle with the line voltage value that samples, and calculates the interior line voltage of this control cycle at (t-τ _e) corresponding constantly line voltage positive-negative sequence component And line voltage positive-negative sequence azimuth speed omega ⁺, ω ^-And next control cycle line voltage is at (t-τ _e) constantly electric network positive and negative preface vector angle With line voltage at (t-τ _i) constantly electrical network positive sequence vector angle

Step 3 (S13) goes out PWM through computes the current control cycle voltage feed-forward control compensation term that the moment needs takes place:

$\left[\begin{array}{c}{e}_{d+}\left(t\right)\\ e_{q+}\left(t\right)\end{array}\right]=\left[\begin{array}{c}{e}_d^{+}(t-{\mathrm{\τ}}_e)\\ e_q^{+}(t-{\mathrm{\τ}}_e)\end{array}\right]+\left[\begin{array}{cc}\cos [\mathrm{\Δ}{\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}+({\mathrm{\ω}}^{+}+{\mathrm{\ω}}^{-}){\mathrm{\τ}}_e]& \sin [\mathrm{\Δ}{\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}+({\mathrm{\ω}}^{+}+{\mathrm{\ω}}^{-}){\mathrm{\τ}}_e]\\ -\sin [\mathrm{\Δ}{\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}+({\mathrm{\ω}}^{+}+{\mathrm{\ω}}^{-}){\mathrm{\τ}}_e]& \cos [\mathrm{\Δ}{\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}+({\mathrm{\ω}}^{+}+{\mathrm{\ω}}^{-}){\mathrm{\τ}}_e]\end{array}\right]\left[\begin{array}{c}{e}_d^{-}(t-{\mathrm{\τ}}_e)\\ e_q^{-}(t-{\mathrm{\τ}}_e)\end{array}\right]$

Wherein, $\mathrm{\Δ}{\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}={\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}^{+}-{\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}^{-};$

Step 4 (S14) goes out meritorious, the idle component of electric current that current control cycle is used to control through computes:

$\left[\begin{array}{c}{i}_{d+}\left(t\right)\\ i_{q+}\left(t\right)\end{array}\right]=\frac{2}{3}\left[\begin{array}{ccc}\cos {\mathrm{\θ}}_{t-{\mathrm{\τ}}_i}^{+}& \cos ({\mathrm{\θ}}_{t-{\mathrm{\τ}}_i}^{+}-\frac{2\mathrm{\π}}{3})& \cos ({\mathrm{\θ}}_{t-{\mathrm{\τ}}_i}^{+}+\frac{2\mathrm{\π}}{3})\\ -\sin {\mathrm{\θ}}_{t-{\mathrm{\τ}}_i}^{+}& -\sin ({\mathrm{\θ}}_{t-{\mathrm{\τ}}_i}^{+}-\frac{2\mathrm{\π}}{3})& -\sin ({\mathrm{\θ}}_{t-{\mathrm{\τ}}_i}^{+}+\frac{2\mathrm{\π}}{3})\end{array}\right]\left[\begin{array}{c}{i}_A(t-{\mathrm{\τ}}_i)\\ i_B(t-{\mathrm{\τ}}_i)\\ i_C(t-{\mathrm{\τ}}_i)\end{array}\right];$

Step 5 (S15) in current control cycle, is used for voltage feed-forward control compensation control with the aforementioned voltage feed-forward control item that calculates, and the current closed-loop that the electric current that calculates is meritorious, idle component is used for system control.

6. combining inverter control method according to claim 5 is characterized in that: wherein in said step 2 (S12), comprise that the three-phase voltage value with sampling obtains the vector [e under the two phase rest frames through the Clarke conversion respectively _α(t-τ _e) e _β(t-τ _e)] ^TThen respectively with angle

Do the Park conversion, obtain based on line voltage vector [e in the synchronous dq+ rotating coordinate system of positive sequence _D+(t-τ _e) e _Q+(t-τ _e)] ^TAnd based on voltage vector [e in the synchronous dq-rotating coordinate system of negative phase-sequence _D-(t-τ _e) e _Q-(t-τ _e)] ^T, wherein, Clarke and Park transformation matrix are respectively:

$C_{3/2}=\frac{2}{3}\left[\begin{array}{ccc}1& -1/2& -1/2\\ 0& \sqrt{3}/2& -\sqrt{3}/2\end{array}\right],$

Obtain the line voltage positive-negative sequence component in this control cycle at last

With line voltage positive-negative sequence azimuth speed omega ⁺, ω ^-And the electric network positive and negative preface vector angle of next control cycle

Wherein, ${\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}^{+}={\∫}_0^t{\mathrm{\ω}}^{+}\mathrm{Dt},$ ${\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}^{-}=-{\∫}_0^t{\mathrm{\ω}}^{-}\mathrm{Dt},,$ ${\mathrm{\θ}}_{t-{\mathrm{\τ}}_i}^{+}={\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}^{+}+{\mathrm{\ω}}^{+}({\mathrm{\τ}}_e-{\mathrm{\τ}}_i).$

7. a combining inverter control method comprises electric network active electric current and reactive current decoupling zero control (201), voltage feed-forward control control (202), and this method comprises:

Step 1 (S11), in current control cycle, sampling line voltage and power network current;

Step 2 (S12) utilizes current control cycle with the line voltage value that samples, and calculates the interior line voltage of this control cycle at (t-τ _e) corresponding constantly line voltage positive-negative sequence component

And line voltage positive-negative sequence azimuth speed omega ⁺, ω ^-And next control cycle line voltage is at (t-τ _e) constantly electric network positive and negative preface vector angle

With line voltage at (t-τ _i) constantly electrical network positive sequence vector angle

Step 3 (S13) goes out PWM through computes the current control cycle voltage feed-forward control compensation term that the moment needs takes place:

$\left[\begin{array}{c}{e}_{d+}\left(t\right)\\ e_{q+}\left(t\right)\end{array}\right]=\left[\begin{array}{c}{e}_d^{+}(t-{\mathrm{\τ}}_e)\\ e_q^{+}(t-{\mathrm{\τ}}_e)\end{array}\right]+\left[\begin{array}{cc}\cos [\mathrm{\Δ}{\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}+({\mathrm{\ω}}^{+}+{\mathrm{\ω}}^{-}){\mathrm{\τ}}_e]& \sin [\mathrm{\Δ}{\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}+({\mathrm{\ω}}^{+}+{\mathrm{\ω}}^{-}){\mathrm{\τ}}_e]\\ -\sin [\mathrm{\Δ}{\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}+({\mathrm{\ω}}^{+}+{\mathrm{\ω}}^{-}){\mathrm{\τ}}_e]& \cos [\mathrm{\Δ}{\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}+({\mathrm{\ω}}^{+}+{\mathrm{\ω}}^{-}){\mathrm{\τ}}_e]\end{array}\right]\left[\begin{array}{c}{e}_d^{-}(t-{\mathrm{\τ}}_e)\\ e_q^{-}(t-{\mathrm{\τ}}_e)\end{array}\right]$

Wherein, $\mathrm{\Δ}{\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}={\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}^{+}-{\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}^{-};$

Step 4 (S14) goes out meritorious, the idle component of electric current that current control cycle is used to control through computes:

$\left[\begin{array}{c}{i}_{d+}\left(t\right)\\ i_{q+}\left(t\right)\end{array}\right]=\frac{2}{3}\left[\begin{array}{ccc}\cos {\mathrm{\θ}}_{t-{\mathrm{\τ}}_i}^{+}& \cos ({\mathrm{\θ}}_{t-{\mathrm{\τ}}_i}^{+}-\frac{2\mathrm{\π}}{3})& \cos ({\mathrm{\θ}}_{t-{\mathrm{\τ}}_i}^{+}+\frac{2\mathrm{\π}}{3})\\ -\sin {\mathrm{\θ}}_{t-{\mathrm{\τ}}_i}^{+}& -\sin ({\mathrm{\θ}}_{t-{\mathrm{\τ}}_i}^{+}-\frac{2\mathrm{\π}}{3})& -\sin ({\mathrm{\θ}}_{t-{\mathrm{\τ}}_i}^{+}+\frac{2\mathrm{\π}}{3})\end{array}\right]\left[\begin{array}{c}{i}_A(t-{\mathrm{\τ}}_i)\\ i_B(t-{\mathrm{\τ}}_i)\\ i_C(t-{\mathrm{\τ}}_i)\end{array}\right];$

Step 5 (S15) in current control cycle, is used for voltage feed-forward control compensation control with the aforementioned voltage feed-forward control item that calculates, and the current closed-loop that the electric current that calculates is meritorious, idle component is used for system control;

At last, with output, the reactive current cross decoupling item-ω of active current adjuster ⁺Li _Q+(t) and voltage feed-forward control item e _D+(t) synthetic jointly v _d(t); Output, active current cross decoupling item ω with the reactive current adjuster ⁺Li _D+(t) and voltage feed-forward control item e _Q+(t) synthetic jointly v _q(t); Again with v _q(t) and v _d(t) with PWM corresponding constantly line voltage azimuth taking place does the PARK inverse transformation and obtains the reference voltage vector v under the two phase rest frames that current control cycle PWM generating module needs _α(t), v _β(t); Wherein the PARK inverse-transform matrix is:

8. combining inverter control method according to claim 7 is characterized in that: wherein in said step 2 (S12), comprise that the three-phase voltage value with sampling obtains the vector [e under the two phase rest frames through the Clarke conversion respectively _α(t-τ _e) e _β(t-τ _e)] ^TThen respectively with angle

Do the Park conversion, obtain based on line voltage vector [e in the synchronous dq+ rotating coordinate system of positive sequence _D+(t-τ _e) e _Q+(t-τ _e)] ^TAnd based on voltage vector [e in the synchronous dq-rotating coordinate system of negative phase-sequence _D-(t-τ _e) e _Q-(t-τ _e)] ^T, wherein, Clarke and Park transformation matrix are respectively:

$C_{3/2}=\frac{2}{3}\left[\begin{array}{ccc}1& -1/2& -1/2\\ 0& \sqrt{3}/2& -\sqrt{3}/2\end{array}\right],$

Obtain the line voltage positive-negative sequence component in this control cycle at last

With line voltage positive-negative sequence azimuth speed omega ⁺, ω ^-And the electric network positive and negative preface vector angle of next control cycle

Wherein, ${\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}^{+}={\∫}_0^t{\mathrm{\ω}}^{+}\mathrm{Dt},$ ${\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}^{-}=-{\∫}_0^t{\mathrm{\ω}}^{-}\mathrm{Dt},$ ${\mathrm{\θ}}_{t-{\mathrm{\τ}}_i}^{+}={\mathrm{\θ}}_{t-{\mathrm{\τ}}_e}^{+}+{\mathrm{\ω}}^{+}({\mathrm{\τ}}_e-{\mathrm{\τ}}_i).$

9. according to claim 7 or 8 described combining inverter control methods, it is characterized in that: corresponding constantly line voltage azimuth takes place for

in described PWM

Images