CN104300812A - 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, particularly relate to a kind of Three-phase PWM Voltage Rectifier Direct Power Auto-disturbance-rejection Control, this method is adapted at using in three-phase AC-DC power converter.

Background technology

Along with the development of modern power electronics technology, microelectric technique and computer technology, the power conversion unit based on PWM technology is subject to extensive concern.Compared with common diode uncontrollable rectifier device, Three-phase PWM Voltage Rectifier has that Current harmonic distortion rate is low, power can two-way flow, can the features such as unity power factor be obtained, eliminate in conventional rectifier circuit and have that harmonic content is large, power factor is low and energy can not the problem such as feedback, the impact etc. that can be used for realizing reactive power compensation, suppress mains by harmonics, weaken power grid, be used to suppress electric network pollution, improve utilization rate of electrical.In addition, Three-phase PWM Voltage Rectifier is also widely used in the renewable energy power generation such as wind power generation, photovoltaic generation field, can run, harmonic carcellation with unity power factor, and can improve the utilance of the regenerative resources such as wind energy.Visible, Three-phase PWM Voltage Rectifier has superior performance, has future in engineering applications and important theoretical research to be widely worth.

In order to make Three-phase PWM Voltage Rectifier operationally input current for sinusoidal wave and with arc in phase or anti-phase, its control technology also develops constantly, emerges different control methods at present.Wherein, be most widely used with the vector control based on grid voltage orientation.Vector control based on grid voltage orientation is a kind of control mode based on synchronous rotating angle, and 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.On this basis, based on PI controller and feedforward compensation, realize regulating the uneoupled control of rectifier and stable state floating.

Vector control strategy based on grid voltage orientation needs to design phase-locked loop, and detect in real time electric network voltage phase information, metrical error can bring adverse effect to the sound state operation characteristic of rectifier.In addition, when adopting vector control strategy, need to carry out feedforward compensation to coupling terms between current axis.System parameters drift and modeling is inaccurate etc. that factor will affect feedforward compensation quality and uneoupled control effect, reduction system run all right.In addition, loaded down with trivial details rotating coordinate transformation increases the operand of rectifier control system, constrains the further lifting of rectifier control performance to a certain extent.

Summary of the invention

The invention provides a kind of Three-phase PWM Voltage Rectifier Direct Power Auto-disturbance-rejection Control, present invention achieves the direct Power Control of rectifier, without the need to phase-locked loop, avoid the adverse effect of phase-detection error to rectifier sound state operation characteristic, described below:

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

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

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

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 switching signal through PWM module.

The described instantaneous active power of acquisition Three-phase PWM Voltage Rectifier input and the step of instantaneous reactive power are specially:

Electrical network three-phase voltage value is obtained and rectifier inputs three-phase electricity flow valuve by alternating voltage and alternating current sample circuit, three-phase voltage value and three-phase electricity flow valuve obtain electrical network phase voltage alpha-beta axle component and rectifier input current alpha-beta axle component respectively after coordinate transform, 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 instantaneous active power, z _2Pfor disturbance quantity w _pestimated value;

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 instantaneous reactive power, z _2Qfor disturbance quantity w _qestimated value;

Above-mentioned b ₀be taken as 1.5/L _g, L _gfor AC reactance.

The beneficial effect of technical scheme provided by the invention is: the method based on the system disturbance of extended state observer real-time monitored, and draws rectifier AC input voltage command value according to power control rate.The method realizes the direct Power Control of rectifier under rest frame, without the need to phase-locked loop, does not need to detect in real time electric network voltage phase information, avoids the adverse effect of phase-detection error to rectifier sound state operation characteristic.In addition, this method does not need to carry out feedforward compensation to coupling terms between current axis, while reduction controls complexity, the Immunity Performance of remarkable elevator system and dynamic response rapidity, effectively inhibit because system parameters drift and the factor such as modeling is inaccurate are on the impact of feedforward compensation quality and uneoupled control effect, improve operation and the control effects of system.

Accompanying drawing explanation

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

Fig. 2 is Three-phase PWM Voltage Rectifier Direct Power Active Disturbance Rejection Control system block diagram provided by the invention.

Embodiment

For making the object, technical solutions and advantages of the present invention clearly, below embodiment of the present invention is described further in detail.

101: the instantaneous active power P obtaining Three-phase PWM Voltage Rectifier input _gwith instantaneous reactive power Q _g;

This step is specially: obtain electrical network three-phase voltage value 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 current alpha-beta axle component respectively after coordinate transform, and then obtain instantaneous active power P _gwith instantaneous reactive power Q _g.

See Fig. 1, u _ga, u _gb, u _gcfor electrical network three-phase voltage, L _gand R _gbe 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 dc-link capacitance.

Under two-phase rest frame, the balance of 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 _{g α}, i _{g β}be respectively rectifier input current alpha-beta axle component; u _{g α}, u _{g β}be respectively electrical network phase voltage alpha-beta axle component; u _{c α}, u _{c β}be 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

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

Instantaneous power over time rate can be written as

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

Electrical network phase voltage alpha-beta axle component over time rate can be written as

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

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 disturbance suffered in active power and Reactive Power Control process 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 carries out real-time monitored as the input of extended state observer to system disturbance.Based on the real-time monitored value z of system disturbance amount _2Pwith z _2Q, instantaneous power calculated value P _gwith Q _g, active power command value P _{g_ref}and reactive power command value Q _{g_ref}, obtain active power controller amount u respectively according to active power controller rate and Reactive Power Control rate _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 variable structure 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, b ₀be taken as 1.5/L _g, z _1Pfor the pursuit gain of active power, z _2Pfor disturbance quantity w _pestimated value, ω _0Pfor the observation bandwidth of active power extended state observer.

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

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

In formula, ω _cPfor the control bandwidth of active power automatic disturbance rejection controller.

With Q _gfor input variable structure reactive power extended state observer observation system disturbance w _q, active power extended 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 _qestimated value, ω _0Qfor the observation bandwidth of reactive power extended state observer.

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

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

In formula, ω _cQfor the control bandwidth of 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 _{g α}and u _{g β}, calculate rectifier AC input voltage alpha-beta axle component instruction value u _{c α _ ref}and u _{c β _ ref};

Wherein, concrete 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 switching signal through PWM module.

Below in conjunction with Fig. 2, describe the operating process of Three-phase PWM Voltage Rectifier Direct Power Auto-disturbance-rejection Control provided by the invention in detail, described below:

D-c bus voltage value u is obtained by DC bus sample circuit _dc, u _dcwith its set-point u _dcerror obtain meritorious reference current through pi regulator, it and DC bus-bar voltage u _dcproduct as the command value P of active power _{g_ref}, for making the power factor of PWM rectifier be 1, the command value Q of reactive power _{g_ref}be zero.

Electrical network three-phase voltage value u is obtained by alternating voltage and alternating current sample circuit _ga, u _gb, u _gcand rectifier input 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 u respectively after coordinate transform _{g α}, u _{g β}and rectifier input current alpha-beta axle component i _{g α}, i _{g β}.Instantaneous active power P is calculated according to formula (2) _g, instantaneous reactive power Q _g.Instantaneous power calculated value carries out real-time monitored as the input of extended state observer to system disturbance.Based on the real-time monitored value z of system disturbance amount _2Pwith z _2Q, instantaneous power calculated value P _gwith Q _g, active power command value P _{g_ref}and reactive power command value Q _{g_ref}, the power control rate according to formula (9), formula (11) obtains active power controller amount u _pwith Reactive Power Control amount u _q.In conjunction with electrical network phase voltage alpha-beta axle component u _{g α}, u _{g β}, obtain rectifier AC input voltage alpha-beta axle component instruction value according to formula (12), obtain rectifier switching signal through PWM module, finally realize the Direct Power Active Disturbance Rejection Control of Three-phase PWM Voltage Rectifier.

It will be appreciated by those skilled in the art that accompanying drawing is the schematic diagram of a preferred embodiment, the invention described above embodiment sequence number, just to describing, does not represent the quality of embodiment.

The foregoing is only preferred embodiment of the present invention, not in order to limit the present invention, within the spirit and principles in the present invention all, any amendment done, equivalent replacement, improvement etc., all should be included within protection scope of the present invention.

Claims (3)

1. a Three-phase PWM Voltage Rectifier Direct Power Auto-disturbance-rejection Control, is characterized in that, said method comprising the steps of:

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

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

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 switching signal through PWM module.

2. a kind of Three-phase PWM Voltage Rectifier Direct Power Auto-disturbance-rejection Control according to claim 1, is characterized in that, the described instantaneous active power of acquisition Three-phase PWM Voltage Rectifier input and the step of instantaneous reactive power are specially:

Electrical network three-phase voltage value is obtained and rectifier inputs three-phase electricity flow valuve by alternating voltage and alternating current sample circuit, three-phase voltage value and three-phase electricity flow valuve obtain electrical network phase voltage alpha-beta axle component and rectifier input current alpha-beta axle component respectively after coordinate transform, 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, it is characterized in that, 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 instantaneous active power, z _2Pfor disturbance quantity w _pestimated value;

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 instantaneous reactive power, z _2Qfor disturbance quantity w _qestimated value;

Above-mentioned b ₀be taken as 1.5/L _g, L _gfor AC reactance.