CN104300812B - Direct power active disturbance rejection control method for three-phase voltage source PWM rectifier - Google Patents

Abstract

The invention discloses a direct power active disturbance rejection control method for a three-phase voltage source PWM rectifier. The method includes the following steps that the input instantaneous active power and the input instantaneous reactive power of the three-phase voltage source PWM rectifier are obtained; the instantaneous active power and the instantaneous reactive power serve as input of an expanded state observer, and based on the real-time observation value, the active power instruction value and the reactive power instruction value of system disturbance quantity, active power control quantity and reactive power control quantity can be respectively obtained according to the active power control rate and the reactive power control rate; according to the active power control quantity, the reactive power control quantity and a network voltage sampling value, the alpha-beta axis component instruction value of the input voltage on the alternating-current side of the rectifier is calculated; according to the alpha-beta axis component instruction value of the input voltage on the alternating-current side of the rectifier, a rectifier switching signal is obtained through a PWM module. Through the method, direct power control over the rectifier is achieved in a static coordinate system, no phase-locked rings are needed, and phase information of network voltage does not need to be detected in real time.

Description

A kind of Three-phase PWM Voltage Rectifier Direct Power Auto-disturbance-rejection Control

Technical field

The present invention relates to Three-phase PWM Voltage Rectifier field, more particularly, to a kind of Three-phase PWM Voltage Rectifier is direct Power Auto-disturbance-rejection Control, this method is suitable for using in three-phase AC-DC power converter.

Background technology

With the development of modern power electronics technology, microelectric technique and computer technology, based on PWM technology Power conversion unit receives significant attention.Compared with common diode uncontrollable rectifier device, Three-phase PWM Voltage Rectifier has Current harmonic distortion rate is low, power can two-way flow, the features such as unity power factor can be obtained, eliminate in conventional rectifier circuit Have such problems as that harmonic content is big, power factor is low and energy is unable to feedback, can be used to realize reactive power compensation, suppression electricity Net harmonic wave, impact of weakening power grid etc., are used for suppressing electric network pollution, improve utilization rate of electrical.Additionally, three-phase voltage Type PWM rectifier is also widely used in the renewable energy power generation such as wind-power electricity generation, photovoltaic generation field, can with unit power because Number runs, harmonic carcellation, and can improve the utilization rate of the regenerative resources such as wind energy.It can be seen that, Three-phase PWM Voltage Rectifier There is superior performance, have extensive future in engineering applications and important theoretical research value.

In order that Three-phase PWM Voltage Rectifier operationally input current be sine wave and with arc in phase or anti-phase, Its control technology also develops constantly, has emerged different control methods at present.Wherein, with the arrow based on grid voltage orientation Amount control is most widely used.It is a kind of control based on synchronous rotating angle based on the vector controlled of grid voltage orientation Mode, the voltage and current under three-phase static coordinate system is converted into the respective value under two-phase rotating coordinate system by the method.Here On the basis of, based on PI controller and feedforward compensation, realize the uneoupled control to rectifier and adjust with stable state floating.

Need to design phaselocked loop based on the vector control strategy of grid voltage orientation, reality is carried out to electric network voltage phase information When detection, detection error can bring adverse effect to the dynamic and static operating characteristics of rectifier.Additionally, adopting vector control strategy When, need to carry out feedforward compensation to electric current between centers coupling terms.Systematic parameter is drifted about and modeled the factor such as inaccurate will affect feedforward Compensate quality and uneoupled control effect, reduce system run all right.Additionally, loaded down with trivial details rotating coordinate transformation increases rectifier The operand of control system, constrains the lifting further of rectifier control performance to a certain extent.

Content of the invention

The invention provides a kind of Three-phase PWM Voltage Rectifier Direct Power Auto-disturbance-rejection Control, present invention realization The direct Power Control of rectifier, without phaselocked loop, it is to avoid phase-detection error is to rectifier dynamic and static operating characteristics Adverse effect, described below：

A kind of Three-phase PWM Voltage Rectifier Direct Power Auto-disturbance-rejection Control, the method comprising the steps of：

Obtain instantaneous active power and the instantaneous reactive power of Three-phase PWM Voltage Rectifier input；

Using described instantaneous active power and instantaneous reactive power as extended state observer input, based on system disturbance The Real-time monitored value of amount, active power command value and reactive power command value, according to active power controller rate and reactive power Control rate respectively obtains active power controller amount and Reactive Power Control amount；

According to active power controller amount, Reactive Power Control amount and line voltage sampled value, calculate rectifier AC Input voltage alpha-beta axle component instruction value；

According to rectifier AC input voltage alpha-beta axle component instruction value, obtain rectifier switch letter through PWM module Number.

The step of the described instantaneous active power obtaining Three-phase PWM Voltage Rectifier input and instantaneous reactive power is concrete For：

Electrical network three-phase voltage value is obtained by alternating voltage and alternating current sample circuit and rectifier inputs three-phase electricity Flow valuve, three-phase voltage value and three-phase electricity flow valuve obtain electrical network phase voltage alpha-beta axle component and rectifier respectively after coordinate transform Input current alpha-beta axle component, and then obtain described instantaneous active power and described instantaneous reactive power.

Described active power controller amount and Reactive Power Control amount are respectively：

Active power controller amount u_P：

$u_P=\frac{{\mathrm{\ω}}_{\mathrm{cP}}(P_{g\_\mathrm{ref}}-P_g)-z_{2P}}{b_0}$

In formula, ω_cPFor the control bandwidth of active power automatic disturbance rejection controller, P_{g_ref}For active power command value, P_gFor wink When active power, z_2PFor disturbance quantity w_PEstimate；

Reactive Power Control amount u_Q：

$u_Q=\frac{{\mathrm{\ω}}_{\mathrm{cQ}}(Q_{g\_\mathrm{ref}}-Q_g)-z_{2Q}}{b_0}$

In formula, ω_cQFor the control bandwidth of reactive power automatic disturbance rejection controller, Q_{g_ref}For reactive power command value, Q_gFor wink When reactive power, z_2QFor disturbance quantity w_QEstimate；

Above-mentioned b₀It is taken as 1.5/L_g, L_gFor AC reactance.

The beneficial effect of technical scheme that the present invention provides is：The method is based on extended state observer real-time monitored system Disturbance, and rectifier AC input voltage command value is drawn according to power control rate.The method is realized under rest frame The direct Power Control of rectifier, without phaselocked loop, be not required to carry out real-time detection to electric network voltage phase information, it is to avoid phase place The adverse effect to rectifier dynamic and static operating characteristics for the detection error.Additionally, this method is not required to electric current between centers coupling terms are carried out Feedforward compensation, while reducing control complexity, is obviously improved Immunity Performance and the dynamic response rapidity of system, effectively Inhibit because of systematic parameter drift and model the impact to feedforward compensation quality and uneoupled control effect for the factor such as inaccurate, improve The operation of system and control effect.

Brief description

Fig. 1 is Three-phase PWM Voltage Rectifier main circuit diagram；

The Three-phase PWM Voltage Rectifier Direct Power Active Disturbance Rejection Control system block diagram that Fig. 2 provides for the present invention.

Specific embodiment

For making the object, technical solutions and advantages of the present invention clearer, below embodiment of the present invention is made further Ground describes in detail.

101：Obtain the instantaneous active power P of Three-phase PWM Voltage Rectifier input_gWith instantaneous reactive power Q_g；

This step is specially：Electrical network three-phase voltage value and rectification are obtained by alternating voltage and alternating current sample circuit Device inputs three-phase electricity flow valuve, and three-phase voltage value and three-phase electricity flow valuve obtain electrical network phase voltage alpha-beta axle respectively after coordinate transform and divide Amount and rectifier input current alpha-beta axle component, and then obtain instantaneous active power P_gWith instantaneous reactive power Q_g.

Referring to Fig. 1, u_ga、u_gb、u_gcFor electrical network three-phase voltage, L_gAnd R_gIt is respectively AC reactance and equivalent resistance；i_ga、 i_gb、i_gcFor rectifier input current, u_ca、u_cb、u_ccFor rectifier AC input voltage, u_dcFor DC bus-bar voltage, C is straight Stream bus capacitor.

Under two-phase rest frame, the voltage equation of Three-phase PWM Voltage Rectifier is

$\left\{\begin{array}{c}{u}_{\mathrm{g\α}}=L_g\frac{{\mathrm{di}}_{\mathrm{g\α}}}{\mathrm{dt}}+R_g{i}_{\mathrm{g\α}}+u_{\mathrm{c\α}}\\ u_{\mathrm{g\β}}=L_g\frac{{\mathrm{di}}_{\mathrm{g\β}}}{\mathrm{dt}}+R_g{i}_{\mathrm{g\β}}+u_{\mathrm{c\β}}\end{array}\right.---\left(1\right)$

In formula, i_gα、i_gβIt is respectively rectifier input current alpha-beta axle component；u_gα、u_gβIt is respectively electrical network phase voltage alpha-beta axle to divide Amount；u_cα、u_cβIt is respectively rectifier AC input voltage alpha-beta axle component.

The instantaneous active power P of Three-phase PWM Voltage Rectifier input_gWith instantaneous reactive power Q_gCan be written as

$\left\{\begin{array}{c}{P}_g=1.5(u_{\mathrm{g\α}}{i}_{\mathrm{g\α}}+u_{\mathrm{g\β}}{i}_{\mathrm{g\β}})\\ Q_g=1.5(u_{\mathrm{g\β}}{i}_{\mathrm{g\α}}-u_{\mathrm{g\α}}{i}_{\mathrm{g\β}})\end{array}\right.---\left(2\right)$

Rate can be written as instantaneous power over time

$\left\{\begin{array}{c}\frac{{\mathrm{dP}}_g}{\mathrm{dt}}=1.5(u_{\mathrm{g\α}}\frac{{\mathrm{di}}_{\mathrm{g\α}}}{\mathrm{dt}}+i_{\mathrm{g\α}}\frac{{\mathrm{du}}_{\mathrm{g\α}}}{\mathrm{dt}}+u_{\mathrm{g\β}}\frac{{\mathrm{di}}_{\mathrm{g\β}}}{\mathrm{dt}}+i_{\mathrm{g\β}}\frac{{\mathrm{du}}_{\mathrm{g\β}}}{\mathrm{dt}})\\ \frac{{\mathrm{dQ}}_g}{\mathrm{dt}}=1.5(u_{\mathrm{g\β}}\frac{{\mathrm{di}}_{\mathrm{g\α}}}{\mathrm{dt}}+i_{\mathrm{g\α}}\frac{{\mathrm{du}}_{\mathrm{g\β}}}{\mathrm{dt}}-u_{\mathrm{g\α}}\frac{{\mathrm{di}}_{\mathrm{g\β}}}{\mathrm{dt}}-i_{\mathrm{g\β}}\frac{{\mathrm{du}}_{\mathrm{g\α}}}{\mathrm{dt}})\end{array}\right.---\left(3\right)$

Rate can be written as electrical network phase voltage alpha-beta axle component over time

$\left\{\begin{array}{c}\frac{{\mathrm{du}}_{\mathrm{g\α}}}{\mathrm{dt}}=-{\mathrm{\ωu}}_{\mathrm{g\β}}\\ \frac{{\mathrm{du}}_{\mathrm{g\β}}}{\mathrm{dt}}={\mathrm{\ωu}}_{\mathrm{g\α}}\end{array}\right.---\left(4\right)$

In formula, ω is electrical network angular frequency.

Formula (1), formula (4) are substituted into formula (3) and can obtain

$\left\{\begin{array}{c}\frac{{\mathrm{dP}}_g}{\mathrm{dt}}=\frac{1.5}{L_g}(u_{\mathrm{g\α}}{u}_{\mathrm{c\α}}+u_{\mathrm{g\β}}{u}_{\mathrm{c\β}})-\frac{R_g}{L_g}{P}_g-{\mathrm{\ωQ}}_g+\frac{1.5}{L_g}(u_{\mathrm{g\α}}^2+u_{\mathrm{g\β}}^2)\\ \frac{{\mathrm{dQ}}_g}{\mathrm{dt}}=\frac{1.5}{L_g}(u_{\mathrm{g\α}}{u}_{\mathrm{c\β}}-u_{\mathrm{g\β}}{u}_{\mathrm{c\α}})-\frac{R_g}{L_g}{Q}_g+{\mathrm{\ωP}}_g\end{array}\right.---\left(5\right)$

Order

$\left\{\begin{array}{c}{w}_P=\frac{R_g}{L_g}{P}_g-{\mathrm{\ωQ}}_g+\frac{1.5}{L_g}(u_{\mathrm{g\α}}^2+u_{\mathrm{g\β}}^2)\\ w_Q=-\frac{R_g}{L_g}{Q}_g={\mathrm{\ωP}}_g\end{array}\right.---\left(6\right)$

In formula, w_P、w_QRepresent suffered disturbance during active power and Reactive Power Control respectively.

Formula (5) can be written as

$\left\{\begin{array}{c}\frac{{\mathrm{dP}}_g}{\mathrm{dt}}=-\frac{1.5}{L_g}(u_{\mathrm{g\α}}{u}_{\mathrm{c\α}}+u_{\mathrm{g\β}}{u}_{\mathrm{c\β}})+w_P=\frac{1.5}{L_g}{u}_P+w_P\\ \frac{{\mathrm{dQ}}_g}{\mathrm{dt}}=\frac{1.5}{L_g}(u_{\mathrm{g\α}}{u}_{\mathrm{c\β}}-u_{\mathrm{g\β}}{u}_{\mathrm{c\α}})+w_Q=\frac{1.5}{L_g}{u}_Q+w_Q\end{array}\right.---\left(7\right)$

102：Obtain active power controller amount u_PWith Reactive Power Control amount u_Q；

Wherein, this step is specially：Instantaneous power calculated value is entered to system disturbance as the input of extended state observer Row real-time monitored.Real-time monitored value z based on system disturbance amount_2PWith z_2Q, instantaneous power calculated value P_gWith Q_g, active power instruction Value P_{g_ref}And reactive power command value Q_{g_ref}, respectively obtained active according to active power controller rate and Reactive Power Control rate Power control quantity u_PWith Reactive Power Control amount u_Q.

When designing Three-phase PWM Voltage Rectifier Direct Power automatic disturbance rejection controller, first with P_gFor input quantity construction Active power extended state observer observation system disturbance w_P, active power extended state observer is as follows：

$\left\{\begin{array}{c}\frac{{\mathrm{dz}}_{1P}}{\mathrm{dt}}=z_{2P}-{2\mathrm{\ω}}_{0P}(z_{1P}-P_g)+b_0{u}_P\\ \frac{{\mathrm{dz}}_{2P}}{\mathrm{dt}}=-{\mathrm{\ω}}_{0P}^2(z_{1P}-P_g)\end{array}\right.---\left(8\right)$

In formula, b₀It is taken as 1.5/L_g, z_1PFor the pursuit gain of active power, z_2PFor disturbance quantity w_PEstimate, ω_0PFor active The observation bandwidth of power extended state observer.

According to the observation output of extended state observer, active power calculating value and reference value, drawn by following control rate Controlled quentity controlled variable u of active power_P：

$u_P=\frac{{\mathrm{\ω}}_{\mathrm{cP}}(P_{g\_\mathrm{ref}}-P_g)-z_{2P}}{b_0}---\left(9\right)$

In formula, ω_cPControl bandwidth for active power automatic disturbance rejection controller.

With Q_gConstruct reactive power extended state observer observation system disturbance w for input quantity_Q, active power expansion state Observer is as follows：

$\left\{\begin{array}{c}\frac{{\mathrm{dz}}_{1Q}}{\mathrm{dt}}=z_{2Q}-{2\mathrm{\ω}}_{0Q}(z_{1Q}-Q_g)+b_0{u}_Q\\ \frac{{\mathrm{dz}}_{2Q}}{\mathrm{dt}}=-{\mathrm{\ω}}_{0Q}^2(z_{1Q}-Q_g)\end{array}\right.---\left(10\right)$

In formula, z_1QFor the pursuit gain of reactive power, z_2QFor disturbance quantity w_QEstimate, ω_0QFor reactive power expansion state The observation bandwidth of observer.

According to the observation output of extended state observer, reactive power calculating value and reference value, drawn by following control rate Reactive Power Control amount u_Q

$u_Q=\frac{{\mathrm{\ω}}_{\mathrm{cQ}}(Q_{g\_\mathrm{ref}}-Q_g)-z_{2Q}}{b_0}---\left(11\right)$

In formula, ω_cQControl bandwidth for reactive power automatic disturbance rejection controller.

103：According to active power controller amount u_P, Reactive Power Control amount u_QAnd line voltage sampled value u_gαAnd u_gβ, meter Calculate rectifier AC input voltage alpha-beta axle component instruction value u_{cα_ref}And u_{cβ_ref}；

Wherein, specific computing formula is shown in formula (12)

$\left[\begin{array}{c}{u}_{\mathrm{c\α}\_\mathrm{ref}}\\ u_{\mathrm{c\β}\_\mathrm{ref}}\end{array}\right]={\left[\begin{array}{cc}-u_{\mathrm{g\α}}& -u_{\mathrm{g\β}}\\ -u_{\mathrm{g\β}}& u_{\mathrm{g\α}}\end{array}\right]}^{-1}\left[\begin{array}{c}{u}_P\\ u_Q\end{array}\right]---\left(12\right)$

104：According to rectifier AC input voltage alpha-beta axle component instruction value, obtain rectifier through PWM module and open OFF signal.

With reference to Fig. 2, describe the Three-phase PWM Voltage Rectifier Direct Power Active Disturbance Rejection Control that the present invention provides in detail The operating process of method, described below：

D-c bus voltage value u is obtained by dc bus sample circuit_dc, u_dcWith its set-point u_dcError through PI adjust Section device obtains meritorious reference current, and it is with DC bus-bar voltage u_dcProduct as active power command value P_{g_ref}, for making The power factor of PWM rectifier is 1, command value Q of reactive power_{g_ref}It is zero.

Electrical network three-phase voltage value u is obtained by alternating voltage and alternating current sample circuit_ga、u_gb、u_gcAnd rectifier is defeated Enter three-phase electricity flow valuve i_ga、i_gb、i_gc, voltage and current sampling data obtain electrical network phase voltage alpha-beta axle component respectively after coordinate transform u_gα、u_gβAnd rectifier input current alpha-beta axle component i_gα、i_gβ.Instantaneous active power P is calculated according to formula (2)_g, instantaneous reactive work( Rate Q_g.Instantaneous power calculated value carries out real-time monitored as the input of extended state observer to system disturbance.Disturbed based on system Real-time monitored value z of momentum_2PWith z_2Q, instantaneous power calculated value P_gWith Q_g, active power command value P_{g_ref}And reactive power refers to Make value Q_{g_ref}, the power control rate according to formula (9), formula (11) obtains active power controller amount u_PAnd Reactive Power Control amount u_Q.In conjunction with electrical network phase voltage alpha-beta axle component u_gα、u_gβ, rectifier AC input voltage alpha-beta axle component is obtained according to formula (12) and refers to Make value, obtain rectifier switching signal through PWM module, finally realize the Direct Power of Three-phase PWM Voltage Rectifier certainly Disturbance rejection control.

It will be appreciated by those skilled in the art that accompanying drawing is the schematic diagram of a preferred embodiment, the embodiments of the present invention Sequence number is for illustration only, does not represent the quality of embodiment.

The foregoing is only presently preferred embodiments of the present invention, not in order to limit the present invention, all spirit in the present invention and Within principle, any modification, equivalent substitution and improvement made etc., should be included within the scope of the present invention.

Claims (3)

1. a kind of Three-phase PWM Voltage Rectifier Direct Power Auto-disturbance-rejection Control it is characterised in that methods described include with Lower step：

Obtain instantaneous active power and the instantaneous reactive power of Three-phase PWM Voltage Rectifier input；

Using described instantaneous active power and instantaneous reactive power as extended state observer input, based on system disturbance amount Real-time monitored value, active power command value, reactive power command value, active power controller rate and Reactive Power Control rate obtain respectively To active power controller amount and Reactive Power Control amount；

According to active power controller amount, Reactive Power Control amount and line voltage sampled value, calculate the input of rectifier AC Voltage alpha-beta axle component instruction value；

According to rectifier AC input voltage alpha-beta axle component instruction value, obtain rectifier switching signal through PWM module.

2. a kind of Three-phase PWM Voltage Rectifier Direct Power Auto-disturbance-rejection Control according to claim 1, its feature It is, the step of the described instantaneous active power and instantaneous reactive power obtaining Three-phase PWM Voltage Rectifier input is specially：

Electrical network three-phase voltage value is obtained by alternating voltage and alternating current sample circuit and rectifier inputs three-phase electricity flow valuve, Three-phase voltage value and three-phase electricity flow valuve obtain electrical network phase voltage alpha-beta axle component and rectifier input electricity respectively after coordinate transform Stream alpha-beta axle component, and then obtain described instantaneous active power and described instantaneous reactive power.

3. a kind of Three-phase PWM Voltage Rectifier Direct Power Auto-disturbance-rejection Control according to claim 1, its feature It is, described active power controller amount and Reactive Power Control amount are respectively：

Active power controller amount u_P：

$u_P=\frac{{\mathrm{\ω}}_{cP}(P_{g\_ref}-P_g)-z_{2P}}{b_0}$

In formula, ω_cPFor the control bandwidth of active power automatic disturbance rejection controller, P_{g_ref}For active power command value, P_gFor instantaneously having Work(power, z_2PFor disturbance quantity w_PEstimate；

Reactive Power Control amount u_Q：

$u_Q=\frac{{\mathrm{\ω}}_{cQ}(Q_{g\_ref}-Q_g)-z_{2Q}}{b_0}$

In formula, ω_cQFor the control bandwidth of reactive power automatic disturbance rejection controller, Q_{g_ref}For reactive power command value, Q_gFor instantaneous nothing Work(power, z_2QFor disturbance quantity w_QEstimate；

Above-mentioned b₀It is taken as 1.5/L_g, L_gFor AC reactance.