CN106452235A - Excitation control method of independent generating system of brushless doubly-fed machine under asymmetric load - Google Patents

Abstract

The invention discloses an excitation control method of an independent generating system of a brushless doubly-fed machine under an asymmetric load. On the basis of positive-sequence and negative-sequence dual dq coordinate systems, a power winding (PW) voltage of a brushless doubly-fed machine is decomposed into a positive-sequence component and a negative-sequence component; a PW voltage positive-sequence component controller and a PW voltage negative-sequence component controller are used for adjusting amplitudes and frequencies of the PW voltage positive-sequence component and the PW voltage negative-sequence component so as to obtain a needed control winding (CW) voltage positive-sequence component and a needed CW voltage negative-sequence component; the CW voltage positive-sequence component and the CW voltage negative-sequence component are added to obtain a final CW voltage given value; according to the given value, a PWM modulation signal and thus an inverter is driven to control the CW; and then the amplitude and frequency of the PW voltage positive-sequence component track the given value respectively and the PW voltage negative-sequence component amplitude converges to zero. With the method, the constant-frequency and constant-voltage generating function of the independent generating system of the brushless doubly-fed machine under the asymmetric load can be realized. Moreover, the control method has advantages of simpleness, high reliability and high robustness.

Description

Brushless dual-feed motor stand alone generating system excitation control method under asymmetric load

Technical field

The invention belongs to brushless dual-feed motor technical field of power generation control, more particularly, to a kind of asymmetric load bar The excitation control method of the brushless dual-feed motor stand alone generating system under part.

Background technology

Brushless dual-feed motor is a kind of new AC induction motor, and this motor is by the stator winding of two sets of different numbers of pole-pairs Constitute with a set of rotor windings.Its general principle is to make two sets of stator winding produce different numbers of pole-pairs through the rotor of particular design Rotating excitation field Indirect Interaction, and it can be interacted and be controlled realizing energy transmission.Brushless dual-feed motor Two sets of stator winding are referred to as power winding (power winding, hereinafter referred to as PW) and controling winding (control Winding, hereinafter referred to as CW), this motor also can have asynchronous machine concurrently as generator operation as motor running Feature with synchronous motor.

Asymmetric load can make existing unbalanced three-phase currents in the PW of brushless dual-feed motor, and unbalanced three-phase currents are in PW Each phase internal impedance on produce different pressure drops, and then make electricity generation system output voltage (i.e. PW voltage) occur asymmetric, This makes under conventional control method, the output voltage amplitude of brushless dual-feed motor stand alone generating system and frequency constant Control targe be difficult to.

Theoretical according to Instantaneous Symmetrical Components, both comprise positive-sequence component in asymmetric voltage and comprise negative sequence component.Sending out A kind of excitation controlling device (application number of brushless dual-feed motor stand alone generating system of bright patent：201510391869.8) provided Control method in, the control to CW electric current is that the method cannot be to PW voltage intrinsically based on single rotating coordinate system In positive-sequence component and negative sequence component be controlled simultaneously.In order that brushless dual-feed motor stand alone generating system is in asymmetric load Under the conditions of also can stable operation, need to build new control method.

Content of the invention

It is an object of the invention to overcoming the deficiencies in the prior art, provide brushless double-fed under the conditions of a kind of asymmetric load Machine stand alone generating system excitation control method, realizes brushless dual-feed motor stand alone generating system and also can under the conditions of asymmetric load Realize the constant frequency and constant voltage generating function under speed change varying duty operating mode.The method is applied to the independent ship based on brushless dual-feed motor Oceangoing ship Shaft-Generator, independent hydroelectric power system and independent wind generator system etc..

In order to realize the technical purpose of the present invention, present invention employs following technical scheme：

Under asymmetric load, brushless dual-feed motor stand alone generating system excitation control method, comprises the steps：

(1) sample PW three-phase voltage instantaneous value u_1a、u_1bAnd u_1c, calculate PW electricity using double Second Order Generalized Integrator phaselocked loops The amplitude of positive pressure order componentsAnd the amplitude of negative sequence component

(2) sample CW three-phase current instantaneous value i_2a、i_2bAnd i_2c, calculate positive sequence d, q in positive synchronous rotating frame for the CW electric current ComponentWithAnd negative phase-sequence d, the q component in negative synchronous rotating frameWith

(3) sample PW three-phase current instantaneous value i_1a、i_1bAnd i_1c, calculate positive sequence d, q in positive synchronous rotating frame for the PW electric current ComponentWithAnd negative phase-sequence d, the q component in negative synchronous rotating frameWith

(4) according to the amplitude of PW voltage positive-sequence componentPositive sequence d, q component in positive synchronous rotating frame for the CW electric currentIt is calculated CW three-phase voltage positive-sequence component set-point using PW voltage positive-sequence component controller With

(5) according to the amplitude of PW voltage negative sequence componentNegative phase-sequence d, q component in negative synchronous rotating frame for the CW electric current WithIt is calculated CW three-phase voltage negative sequence component set-point using PW voltage negative sequence component controllerWith

(6) positive sequence of CW voltage is added with negative sequence component set-point and obtains CW voltage set-pointWithProfit Generate modulated signal with SVPWM algorithm, and then make inverter export corresponding voltage to CW；

(7) repeat the above steps (1)～(6), make the amplitude of PW voltage positive-sequence component and frequency follow the tracks of set-point respectively, bear The amplitude of order components converges to 0.

Further, the specific implementation of described step (2) is：

Calculate the phase place of CW negative-sequence current first

Wherein, θ₁For PW voltage positive-sequence component phase place,Phase place for CW forward-order current

Then adopt the phase place of CW forward-order currentBy CW three-phase current instantaneous value i_2a、i_2bAnd i_2cBecome from abc coordinate system Transformation changes to positive synchronous rotating frame, obtains d, q component in positive synchronous rotating frame for the CW electric currentWithUsing CW negative phase-sequence electricity The phase place of streamBy CW three-phase current instantaneous value i_2a、i_2bAnd i_2cFrom abc coordinate system transformation to negative synchronous rotating frame, obtain CW electricity D, q component in negative synchronous rotating frame for the streamWithConversion expression formula is as follows：

Right respectively using notch filterWithIt is filtered, obtain CW electric current in positive synchronous rotating frame In positive sequence d, q componentWithAnd negative phase-sequence d, the q component in negative synchronous rotating frameWith

Further, the concrete methods of realizing of described step (3) is：

Calculate the phase place of PW forward-order current firstPhase place with PW negative-sequence current

Wherein p₁For the number of pole-pairs of power winding PW, p₂For the number of pole-pairs of controling winding CW, η is the machinery between PW and CW Angular deviation；

Then adopt the phase place of PW forward-order currentBy PW three-phase current instantaneous value i_1a、i_1bAnd i_1cFrom abc coordinate system transformation Transform to positive synchronous rotating frame to obtainWithPhase place using PW negative-sequence currentBy PW three-phase current instantaneous value i_1a、i_1bWith i_1cTransform to negative synchronous rotating frame from abc coordinate system transformation to obtainWithConversion expression formula is as follows：

Right respectively using notch filterWithIt is filtered, obtain PW electric current in positive synchronous rotating frame In positive sequence d, q componentWithAnd negative phase-sequence d, the q component in negative synchronous rotating frameWith

Further, the concrete methods of realizing of described step (4) is：

Calculate the amplitude of PW voltage positive-sequence componentWith given amplitudeDifference, this difference is adjusted as a PI The input of device, the first pi regulator is output as CW electric current positive sequence amplitude regulated quantity With the feedforward of CW electric current positive sequence amplitude AmountIt is added the set-point obtaining CW electric current positive sequence amplitude

Calculate PW electric voltage frequency ω₁With given frequencyDifference, using this difference as the second pi regulator input, Two pi regulators are output as CW power frequency regulated quantity With CW power frequency feedforward amountAddition is just obtaining CW The frequency of sequence electric currentRightIntegration obtains the phase place of CW forward-order current

Make positive sequence d axle component set-point in positive synchronous rotating frame for the CW electric currentIt is equal toCalculateWith's Difference, using this difference as the 3rd pi regulator input, the output of the 3rd pi regulator and CW voltage are in positive synchronous rotating frame In positive sequence d axle feedforward amountIt is added, obtain positive sequence d axle set-point in positive synchronous rotating frame for the CW voltage

Make positive sequence q axle component set-point in positive synchronous rotating frame for the CW electric currentEqual to 0, calculateWithDifference Value, using this difference as the 4th pi regulator input, the output of the 4th pi regulator and CW voltage are in positive synchronous rotating frame Positive sequence q axle feedforward amountIt is added, obtain positive sequence q axle set-point in positive synchronous rotating frame for the CW voltage

Finally adopt the phase place of CW forward-order currentWillWithTransform to abc coordinate system from positive synchronous rotating frame, Obtain the CW three-phase voltage positive-sequence component set-point in abc coordinate systemWith

Further, described CW electric current positive sequence amplitude feedforward amountCW power frequency feedforward amountCW voltage positive sequence d Axle feedforward amountWith CW voltage positive sequence q axle feedforward amountComputational methods be：

In formula,

In formula,

In formula,

WhereinLeakage inductance coefficient for CW, ω_rFor motor speed, ω₁For PW electric voltage frequency, For the frequency of CW forward-order current, L_1rFor the mutual inductance between PW and rotor, L_2rFor the mutual inductance between CW and rotor, L₁For PW from Sense, L₂Self-induction for CW, L_rFor the self-induction of rotor, R₁Phase resistance for PW, R₂Phase resistance for CW, R_rPhase resistance for rotor；

WillWithThe expression formula transforming to abc coordinate system from positive synchronous rotating frame is：

In the present invention, ω_rCan calculate as follows：

(1-1) sample motor rotor-position signal instantaneous value θ_r；

(1-2) θ to adjacent double sampling_rCarry out calculus of differences；

(1-3) calculated result is filtered to (1-2) to adopt low-pass first order filter, obtains motor speed ω_r.

Further, the concrete methods of realizing of described step (5) is as follows：

Calculate the amplitude of PW voltage negative sequence componentWith given amplitudeDifference, this difference is adjusted as the 5th PI The input of device, the 5th pi regulator is output as CW electric current negative phase-sequence amplitude regulated quantity With the feedforward of CW electric current negative phase-sequence amplitude AmountIt is added the set-point obtaining CW electric current negative phase-sequence amplitude

Make negative phase-sequence d axle component set-point in negative synchronous rotating frame for the CW electric currentIt is equal toCalculate CW electric current negative Negative phase-sequence d component in sequence dq coordinate systemWithDifference, using this difference as the 6th pi regulator input, the 6th PI Output and the negative phase-sequence d axle feedforward amount in negative synchronous rotating frame for the CW voltage of adjusterIt is added, obtain CW voltage in negative phase-sequence Negative phase-sequence d axle set-point in dq coordinate system

Make negative phase-sequence q axle component set-point in negative synchronous rotating frame for the CW electric currentEqual to 0, calculate CW electric current in negative phase-sequence Negative phase-sequence q component in dq coordinate systemWithDifference, using this difference as the 7th pi regulator input, the 7th PI adjust Output and the negative phase-sequence q axle feedforward amount in negative synchronous rotating frame for the CW voltage of deviceIt is added, obtain CW voltage and sit in negative phase-sequence dq Negative phase-sequence q axle set-point in mark system

Finally adopt the phase place of CW negative-sequence currentWillWithTransform to abc coordinate system from negative synchronous rotating frame, Obtain the CW three-phase voltage negative sequence component set-point in abc coordinate systemWith

Further, described CW electric current negative phase-sequence amplitude feedforward amountNegative phase-sequence d axle in negative synchronous rotating frame for the CW voltage Feedforward amountWith negative phase-sequence q component in negative synchronous rotating frame for the CW electric currentComputational methods be：

In formula,

In formula,

In formula, WhereinLeakage inductance coefficient for CW, ω_rFor motor speed, ω₁For PW electric voltage frequency,For CW negative phase-sequence The frequency of electric current, L_1rFor the mutual inductance between PW and rotor, L_2rFor the mutual inductance between CW and rotor, L₁Self-induction for PW, L₂For CW Self-induction, L_rFor the self-induction of rotor, R₁Phase resistance for PW, R₂Phase resistance for CW, R_rPhase resistance for rotor.

WillWithThe expression formula transforming to abc coordinate system from negative synchronous rotating frame is：

Further, the CW three-phase voltage set-point in described step (6)WithIt is to be calculated by step (5) The CW three-phase voltage positive-sequence component set-point obtaining is added with step (6) calculated CW three-phase voltage negative sequence component set-point Obtain, its expression formula is：

The Advantageous Effects of the present invention are embodied in：

Under the conditions of asymmetric load provided by the present invention, brushless dual-feed motor stand alone generating system excitation control method is Based on the double dq coordinate system of positive and negative sequence, PW voltage positive-sequence component controller is according to the positive-sequence component amplitude of PW voltage and giving of frequency Definite value and value of feedback adjust CW voltage positive-sequence component, and PW voltage negative sequence component controller is according to the negative sequence component amplitude of PW voltage Set-point and value of feedback adjust CW voltage negative sequence component, and PW voltage negative sequence controller does not need the frequency to PW voltage negative sequence component It is controlled, this is because the frequency of the frequency of positive-sequence component and negative sequence component is identical, if the frequency to positive-sequence component Achieve good tracking, then also naturally achieve the tracking to negative sequence component frequency.CW voltage positive and negative sequence component is added Obtain CW voltage set-point finally, PWM modulation signal is produced according to this set-point, and then drive inverter that CW is controlled. Balanced load is a kind of special circumstances of asymmetric load, and control method provided by the present invention can equally be well applied to balanced load Under the conditions of brushless dual-feed motor stand alone generating system run control.

Brief description

Fig. 1 be the embodiment of the present invention asymmetric load under brushless dual-feed motor stand alone generating system excitation control method stream Cheng Tu；

Fig. 2 is the theory diagram that the embodiment of the present invention is decomposed in positive-negative sequence rotating coordinate system to CW electric current；

Fig. 3 is the theory diagram that the embodiment of the present invention is decomposed in positive-negative sequence rotating coordinate system to PW electric current；

Fig. 4 is the PW voltage positive-sequence component controller principle block diagram of the embodiment of the present invention；

Fig. 5 is the PW voltage negative sequence component controller principle block diagram of the embodiment of the present invention；

Fig. 6 (a) is to control using described in a kind of excitation controlling device of patent of invention brushless dual-feed motor stand alone generating system PW line voltage waveform during method processed；

Fig. 6 (b) is to control using described in a kind of excitation controlling device of patent of invention brushless dual-feed motor stand alone generating system CW phase current waveform during method processed；

Fig. 7 (a) is the PW line voltage waveform of the embodiment of the present invention；

Fig. 7 (b) is the CW phase current waveform of the embodiment of the present invention.

Specific embodiment

In order that the objects, technical solutions and advantages of the present invention become more apparent, below in conjunction with drawings and Examples, right The present invention is further elaborated.It should be appreciated that specific embodiment described herein is only in order to explain the present invention, and It is not used in the restriction present invention.

In embodiments of the present invention, as shown in figure 1, comprising the steps：

(1) sample PW three-phase voltage instantaneous value u_1a、u_1bAnd u_1c, calculate PW electricity using double Second Order Generalized Integrator phaselocked loops The amplitude of positive pressure order componentsAnd the amplitude of negative sequence component

(2) sample CW three-phase current instantaneous value i_2a、i_2bAnd i_2c, calculate positive sequence d, q in positive synchronous rotating frame for the CW electric current ComponentWithAnd negative phase-sequence d, the q component in negative synchronous rotating frameWith

(3) sample PW three-phase current instantaneous value i_1a、i_1bAnd i_1c, calculate positive sequence d, q in positive synchronous rotating frame for the PW electric current ComponentWithAnd negative phase-sequence d, the q component in negative synchronous rotating frameWith

(4) it is calculated CW three-phase voltage positive-sequence component set-point using PW voltage positive-sequence component controller With

(5) it is calculated CW three-phase voltage negative sequence component set-point using PW voltage negative sequence component controller With

(6) positive sequence of CW three-phase voltage is added with negative sequence component set-point and obtains CW three-phase voltage set-pointWithGenerate modulated signal using SVPWM algorithm, and then make inverter export corresponding voltage to CW；

(7) repeat the above steps (1)～(6), make the amplitude of PW voltage positive-sequence component and frequency follow the tracks of set-point respectively, bear The amplitude of order components converges to 0.

In embodiments of the present invention, as shown in Fig. 2 the specific embodiment of step (2) is：

Calculate the phase place of CW negative-sequence current firstThen adopt the phase place of CW forward-order currentWill as reference angle i_2a、i_2bAnd i_2cTransform to positive synchronous rotating frame from abc coordinate system transformation, obtain CW electric current d, q in positive synchronous rotating frame and divide AmountWithPhase place using CW negative-sequence currentBy i_2a、i_2bAnd i_2cFrom abc coordinate system transformation to negative synchronous rotating frame, obtain To d, q component in negative synchronous rotating frame for the CW electric currentWithUsing damped coefficient it isTrap frequency is 2 times of PW electricity The notch filter of pressure rated frequency is right respectivelyWithIt is filtered, obtain CW electric current in positive synchronous rotating frame In positive sequence d, q componentWithAnd negative phase-sequence d, the q component in negative synchronous rotating frameWith

In embodiments of the present invention, as shown in figure 3, the specific embodiment of step (3) is：

Calculate the phase place of PW forward-order current firstPhase place with PW negative-sequence currentThen adopt PW forward-order current Phase placeBy i_1a、i_1bAnd i_1cTransform to positive synchronous rotating frame from abc coordinate system transformation to obtainWithUsing PW negative-sequence current Phase placeBy i_1a、i_1bAnd i_1cTransform to negative synchronous rotating frame from abc coordinate system transformation to obtainWithUsing damped coefficient ForTrap frequency is that the notch filter of 2 times of PW voltagerating frequencies is right respectivelyWithIt is filtered, Obtain positive sequence d, q component in positive synchronous rotating frame for the PW electric currentWithAnd negative phase-sequence d, q in negative synchronous rotating frame divides AmountWith

In embodiments of the present invention, as shown in figure 4, the specific embodiment of step (4) is：

Calculate the amplitude of PW voltage positive-sequence componentWith given amplitudeDifference, using this difference as pi regulator 1 Input, pi regulator 1 is output as CW electric current positive sequence amplitude regulated quantity With CW electric current positive sequence amplitude feedforward amount It is added the set-point obtaining CW electric current positive sequence amplitudeCalculate PW electric voltage frequency ω₁With given frequencyDifference, this is poor Value is output as CW power frequency regulated quantity as the input of pi regulator 2, pi regulator 2 With CW power frequency Feedforward amountIt is added the frequency obtaining CW forward-order currentRightIntegration obtains the phase place of CW forward-order currentMake CW electricity Positive sequence d axle component set-point in positive synchronous rotating frame for the streamIt is equal toCalculateWithDifference, by this difference make For the input of pi regulator 3, output and the positive sequence d axle feedforward amount in positive synchronous rotating frame for the CW voltage of pi regulator 3 It is added, obtain positive sequence d axle set-point in positive synchronous rotating frame for the CW voltageMake CW electric current in positive synchronous rotating frame Positive sequence q axle component set-pointEqual to 0, calculateWithDifference, using this difference as pi regulator 4 input, PI adjust The output of section device 4 and positive sequence q axle feedforward amount in positive synchronous rotating frame for the CW voltageIt is added, obtain CW voltage in positive sequence dq Positive sequence q axle set-point in coordinate systemFinally adopt the phase place of CW forward-order currentWillWithSit from positive sequence dq Mark system transforms to abc coordinate system, obtains the CW three-phase voltage positive-sequence component set-point in abc coordinate systemWith

In embodiments of the present invention, as shown in figure 5, the specific embodiment of step (5) is：

Calculate the amplitude of PW voltage negative sequence componentWith given amplitudeDifference, using this difference as pi regulator 5 Input, pi regulator 5 is output as CW electric current negative phase-sequence amplitude regulated quantity With CW electric current negative phase-sequence amplitude feedforward amount It is added the set-point obtaining CW electric current negative phase-sequence amplitudeMake negative phase-sequence d axle component set-point in negative synchronous rotating frame for the CW electric currentIt is equal toCalculateWithDifference, using this difference as pi regulator 6 input, the output of pi regulator 6 and CW Negative phase-sequence d axle feedforward amount in negative synchronous rotating frame for the voltageIt is added, obtain negative phase-sequence d in negative synchronous rotating frame for the CW voltage Axle set-pointMake negative phase-sequence q axle component set-point in negative synchronous rotating frame for the CW electric currentEqual to 0, calculateWith Difference, using this difference as pi regulator 7 input, pi regulator 7 output with CW voltage in negative synchronous rotating frame Negative phase-sequence q axle feedforward amountIt is added, obtain negative phase-sequence q axle set-point in negative synchronous rotating frame for the CW voltageFinally adopt The phase place of CW negative-sequence currentWillWithTransform to abc coordinate system from negative synchronous rotating frame, obtain in abc coordinate system CW three-phase voltage negative sequence component set-pointWith

In embodiments of the present invention, by step (4) calculated CW three-phase voltage positive-sequence component set-pointWith step (5) calculated CW three-phase voltage negative sequence component set-pointCorresponding addition obtains the CW three-phase voltage set-point in step (6)With,Then Generate modulated signal using SVPWM algorithm, and then make inverter export corresponding voltage to CW.

In the present embodiment, the rated power of brushless dual-feed motor is 30kw, and the number of pole-pairs of PW and CW is respectively 1 and 3, PW It is respectively 380V and 320V with the rated voltage of CW, the rated current of PW and CW is respectively 45A and 40A, and synchronous rotational speed is 750r/ Mutual inductance L between min, PW and rotor_1rFor 0.1175H, the mutual inductance L between CW and rotor_2rFor 0.3359H, self-induction L of PW₁For Self-induction L of 0.4519H, CW₂For 0.4977H, self-induction L of rotor_rFor 0.0366H, phase resistance R of PW₁For 2.73 Ω, the phase of CW Resistance R₂For 1.16 Ω, phase resistance R of rotor_rFor 0.1822 Ω.Used asymmetric load in the present embodiment, its A phase is 25 Ω resistive load, its B phase is 100 Ω resistive loads with C phase.Brushless dual-feed motor output line voltage (i.e. PW voltage) virtual value It is respectively 380V, 50Hz with the given set-point of frequency, when being tested, the rotating speed of brushless dual-feed motor is maintained at 930rpm.

Fig. 6 (a) is to control using described in a kind of excitation controlling device of patent of invention brushless dual-feed motor stand alone generating system PW line voltage waveform during method processed.The ordinate of Fig. 6 (a) is PW line voltage, and unit is V；Abscissa is the time, and unit is s.

Fig. 6 (b) is to control using described in a kind of excitation controlling device of patent of invention brushless dual-feed motor stand alone generating system CW phase current waveform during method processed.The ordinate of Fig. 6 (b) is CW phase current, and unit is A；Abscissa is the time, and unit is s.

Fig. 7 (a) is the PW line voltage waveform of the embodiment of the present invention.The ordinate of Fig. 7 (a) is PW line voltage, and unit is V； Abscissa is the time, and unit is s.

Fig. 7 (b) is the CW phase current waveform of the embodiment of the present invention.The ordinate of Fig. 7 (b) is CW phase current, and unit is A； Abscissa is the time, and unit is s.

As shown in Fig. 6 (a), in brushless dual-feed motor stand alone generating system band asymmetric load, according to patent of invention A kind of control method described in excitation controlling device of brushless dual-feed motor stand alone generating system, PW line voltage waveform occurs seriously not Symmetrically.The asymmetric coupling by brushless double-fed machine rotor of PW voltage makes CW phase current also create distortion, such as Fig. 6 Shown in (b).

As shown in Fig. 7 (a), in brushless dual-feed motor stand alone generating system band asymmetric load, according to institute of the present invention State control method, PW line voltage waveform significantly improves.And CW phase current shows as being superimposed on the basis of fundamental wave necessarily The harmonic wave of amount, such as shown in Fig. 7 (b).

As it will be easily appreciated by one skilled in the art that the foregoing is only presently preferred embodiments of the present invention, not in order to Limit the present invention, all any modification, equivalent and improvement made within the spirit and principles in the present invention etc., all should comprise Within protection scope of the present invention.

Claims (8)

1. brushless dual-feed motor stand alone generating system excitation control method under asymmetric load, its feature exists, and comprises the steps：

(1) sample PW three-phase voltage instantaneous value u_1a、u_1bAnd u_1c, just calculating PW voltage using double Second Order Generalized Integrator phaselocked loops The amplitude of order componentsAnd the amplitude of negative sequence component

(2) sample CW three-phase current instantaneous value i_2a、i_2bAnd i_2c, calculate positive sequence d, q component in positive synchronous rotating frame for the CW electric currentWithAnd negative phase-sequence d, the q component in negative synchronous rotating frameWith

(3) sample PW three-phase current instantaneous value i_1a、i_1bAnd i_1c, calculate positive sequence d, q component in positive synchronous rotating frame for the PW electric currentWithAnd negative phase-sequence d, the q component in negative synchronous rotating frameWith

(4) according to the amplitude of PW voltage positive-sequence componentPositive sequence d, q component in positive synchronous rotating frame for the CW electric currentIt is calculated CW three-phase voltage positive-sequence component set-point using PW voltage positive-sequence component controller With

(5) according to the amplitude of PW voltage negative sequence componentNegative phase-sequence d, q component in negative synchronous rotating frame for the CW electric currentWithIt is calculated CW three-phase voltage negative sequence component set-point using PW voltage negative sequence component controllerWith

(6) positive sequence of CW three-phase voltage is added with negative sequence component set-point and obtains CW three-phase voltage set-pointWithGenerate modulated signal using SVPWM algorithm, and then make inverter export corresponding voltage to CW；

(7) repeat the above steps (1)～(6), make the amplitude of PW voltage positive-sequence component and frequency follow the tracks of set-point respectively, negative phase-sequence is divided The amplitude of amount converges to 0.

2. brushless dual-feed motor stand alone generating system excitation control method under asymmetric load according to claim 1, its It is characterised by, the specific implementation of described step (2) is：

Calculate the phase place of CW negative-sequence current first

${\mathrm{\θ}}_2^{-}={\mathrm{\θ}}_2^{+}+2{\mathrm{\θ}}_1$

Wherein, θ₁For PW voltage positive-sequence component phase place,Phase place for CW forward-order current

Then adopt the phase place of CW forward-order currentBy CW three-phase current instantaneous value i_2a、i_2bAnd i_2cFrom the conversion of abc coordinate system transformation To positive synchronous rotating frame, obtain d, q component in positive synchronous rotating frame for the CW electric currentWithPhase using CW negative-sequence current PositionBy CW three-phase current instantaneous value i_2a、i_2bAnd i_2cFrom abc coordinate system transformation to negative synchronous rotating frame, obtain CW electric current negative D, q component in sequence dq coordinate systemWithConversion expression formula is as follows：

$\left[\begin{array}{c}{i}_{2d}^{+}\\ i_{2q}^{+}\end{array}\right]=\frac{2}{3}\left[\begin{array}{ccc}{\mathrm{cos\θ}}_2^{+}& \cos \left({\mathrm{\θ}}_2^{+}-2\mathrm{\π}/3\right)& \cos \left({\mathrm{\θ}}_2^{+}-4\mathrm{\π}/3\right)\\ -{\mathrm{sin\θ}}_2^{+}& -\sin \left({\mathrm{\θ}}_2^{+}-2\mathrm{\π}/3\right)& -\sin \left({\mathrm{\θ}}_2^{+}-4\mathrm{\π}/3\right)\end{array}\right]\left[\begin{array}{c}{i}_{2a}\\ i_{2b}\\ i_{2c}\end{array}\right]$

$\left[\begin{array}{c}{i}_{2d}^{-}\\ i_{2q}^{-}\end{array}\right]=\frac{2}{3}\left[\begin{array}{ccc}{\mathrm{cos\θ}}_2^{-}& \cos \left({\mathrm{\θ}}_2^{-}-2\mathrm{\π}/3\right)& \cos \left({\mathrm{\θ}}_2^{-}-4\mathrm{\π}/3\right)\\ -{\mathrm{sin\θ}}_2^{-}& -\sin \left({\mathrm{\θ}}_2^{-}-2\mathrm{\π}/3\right)& -\sin \left({\mathrm{\θ}}_2^{-}-4\mathrm{\π}/3\right)\end{array}\right]\left[\begin{array}{c}{i}_{2a}\\ i_{2b}\\ i_{2c}\end{array}\right];$

Right respectively using notch filterWithIt is filtered, obtain CW electric current in positive synchronous rotating frame Positive sequence d, q componentWithAnd negative phase-sequence d, the q component in negative synchronous rotating frameWith

3. brushless dual-feed motor stand alone generating system excitation control method under asymmetric load according to claim 2, its It is characterised by, the concrete methods of realizing of described step (3) is：

Calculate the phase place of PW forward-order current firstPhase place with PW negative-sequence current

${\mathrm{\θ}}_1^{+}={\mathrm{\θ}}_2^{+}-(p_1+p_2){\mathrm{\θ}}_r+p_2\mathrm{\η}$

${\mathrm{\θ}}_1^{-}={\mathrm{\θ}}_2^{-}-(p_1+p_2){\mathrm{\θ}}_r+p_2\mathrm{\η}$

Wherein p₁For the number of pole-pairs of power winding PW, p₂For the number of pole-pairs of controling winding CW, η is the mechanical angle between PW and CW Deviation；

Then adopt the phase place of PW forward-order currentBy PW three-phase current instantaneous value i_1a、i_1bAnd i_1cFrom the conversion of abc coordinate system transformation Obtain to positive synchronous rotating frameWithPhase place using PW negative-sequence currentBy PW three-phase current instantaneous value i_1a、i_1bAnd i_1cFrom Abc coordinate system transformation transforms to negative synchronous rotating frame and obtainsWithConversion expression formula is as follows：

$\left[\begin{array}{c}{i}_{1d}^{+}\\ i_{1q}^{+}\end{array}\right]=\frac{2}{3}\left[\begin{array}{ccc}{\mathrm{cos\θ}}_1^{+}& \cos \left({\mathrm{\θ}}_1^{+}-2\mathrm{\π}/3\right)& \cos \left({\mathrm{\θ}}_1^{+}-4\mathrm{\π}/3\right)\\ -{\mathrm{sin\θ}}_1^{+}& -\sin \left({\mathrm{\θ}}_1^{+}-2\mathrm{\π}/3\right)& -\sin \left({\mathrm{\θ}}_1^{+}-4\mathrm{\π}/3\right)\end{array}\right]\left[\begin{array}{c}{i}_{1a}\\ i_{1b}\\ i_{1c}\end{array}\right]$

$\left[\begin{array}{c}{i}_{1d}^{-}\\ i_{1q}^{-}\end{array}\right]=\frac{2}{3}\left[\begin{array}{ccc}{\mathrm{cos\θ}}_1^{-}& \cos \left({\mathrm{\θ}}_1^{-}-2\mathrm{\π}/3\right)& \cos \left({\mathrm{\θ}}_1^{-}-4\mathrm{\π}/3\right)\\ -{\mathrm{sin\θ}}_1^{-}& -\sin \left({\mathrm{\θ}}_1^{-}-2\mathrm{\π}/3\right)& -\sin \left({\mathrm{\θ}}_1^{-}-4\mathrm{\π}/3\right)\end{array}\right]\left[\begin{array}{c}{i}_{1a}\\ i_{1b}\\ i_{1c}\end{array}\right]$

Right respectively using notch filterWithIt is filtered, obtain PW electric current in positive synchronous rotating frame Positive sequence d, q componentWithAnd negative phase-sequence d, the q component in negative synchronous rotating frameWith

4. brushless dual-feed motor stand alone generating system excitation control method under asymmetric load according to claim 1, its It is characterised by, the concrete methods of realizing of described step (4) is：

Calculate the amplitude of PW voltage positive-sequence componentWith given amplitudeDifference, using this difference as the first pi regulator Input, the first pi regulator is output as CW electric current positive sequence amplitude regulated quantityWith CW electric current positive sequence amplitude feedforward amountIt is added the set-point obtaining CW electric current positive sequence amplitude

Calculate PW electric voltage frequency ω₁With given frequencyDifference, using this difference as the second pi regulator input, the 2nd PI Adjuster is output as CW power frequency regulated quantityWith CW power frequency feedforward amountAddition obtains CW positive sequence The frequency of electric currentRightIntegration obtains the phase place of CW forward-order current

Make positive sequence d axle component set-point in positive synchronous rotating frame for the CW electric currentIt is equal toCalculateWithDifference, Using this difference as the 3rd pi regulator input, the 3rd pi regulator output with CW voltage in positive synchronous rotating frame just Sequence d axle feedforward amountIt is added, obtain positive sequence d axle set-point in positive synchronous rotating frame for the CW voltage

Make positive sequence q axle component set-point in positive synchronous rotating frame for the CW electric currentEqual to 0, calculateWithDifference, will This difference is as the input of the 4th pi regulator, output and the positive sequence in positive synchronous rotating frame for the CW voltage of the 4th pi regulator Q axle feedforward amountIt is added, obtain positive sequence q axle set-point in positive synchronous rotating frame for the CW voltage

Finally adopt the phase place of CW forward-order currentWillWithTransform to abc coordinate system from positive synchronous rotating frame, obtain CW three-phase voltage positive-sequence component set-point in abc coordinate systemWith

5. brushless dual-feed motor stand alone generating system excitation control method under asymmetric load according to claim 4, its It is characterised by, described CW electric current positive sequence amplitude feedforward amountCW power frequency feedforward amountCW voltage positive sequence d axle feedforward amountWith CW voltage positive sequence q axle feedforward amountComputational methods be：

$I_{2E}^{+}=\{({\mathrm{\β}}_1^{+}{i}_{1d+}^{+}+R_1{i}_{1q+}^{+})+{\[2{\mathrm{\β}}_1^{+}{R}_1{i}_{1d+}^{+}{i}_{1q+}^{+}-R_1^2{\left(i_{1d+}^{+}\right)}^2-{\left({\mathrm{\β}}_1^{+}\right)}^2{\left(i_{1q+}^{+}\right)}^2+U_1^{+*}\]}^{1/2}\}/{\mathrm{\β}}_2^{+}$

In formula,

${\mathrm{\ω}}_{2f}^{+}={\mathrm{\ω}}_r(p_1+p_2)-{\mathrm{\ω}}_1$

$u_{2df+}^{+}={\mathrm{\α}}_1^{+}{i}_{2q+}^{+}+{\mathrm{\α}}_2^{+}{i}_{1d+}^{+}+{\mathrm{\α}}_3^{+}{i}_{1q+}^{+}$

In formula,

$u_{2qf+}^{+}={\mathrm{\α}}_4^{+}{i}_{2d+}^{+}+{\mathrm{\α}}_5^{+}{i}_{1d+}^{+}+{\mathrm{\α}}_6^{+}{i}_{1q+}^{+}$

In formula, WhereinLeakage inductance coefficient for CW, ω_rFor motor speed, ω₁For PW electric voltage frequency,For CW positive sequence The frequency of electric current, L_1rFor the mutual inductance between PW and rotor, L_2rFor the mutual inductance between CW and rotor, L₁Self-induction for PW, L₂For CW Self-induction, L_rFor the self-induction of rotor, R₁Phase resistance for PW, R₂Phase resistance for CW, R_rPhase resistance for rotor；

WillWithThe expression formula transforming to abc coordinate system from positive synchronous rotating frame is：

$\left[\begin{array}{c}{u}_{2a+}^{*}\\ u_{2b+}^{*}\\ u_{2c+}^{*}\end{array}\right]=\left[\begin{array}{cc}{\mathrm{cos\θ}}_2^{+}& -{\mathrm{sin\θ}}_2^{+}\\ \cos \left({\mathrm{\θ}}_2^{+}-2\mathrm{\π}/3\right)& -\sin \left({\mathrm{\θ}}_2^{+}-2\mathrm{\π}/3\right)\\ \cos \left({\mathrm{\θ}}_2^{+}-4\mathrm{\π}/3\right)& -\sin \left({\mathrm{\θ}}_2^{+}-2\mathrm{\π}/3\right)\end{array}\right]\left[\begin{array}{c}{u}_{2d+}^{+*}\\ u_{2q+}^{+*}\end{array}\right]$

6. brushless dual-feed motor stand alone generating system excitation control method under asymmetric load according to claim 1, its It is characterised by, the concrete methods of realizing of described step (5) is as follows：

Calculate the amplitude of PW voltage negative sequence componentWith given amplitudeDifference, using this difference as the 5th pi regulator Input, the 5th pi regulator is output as CW electric current negative phase-sequence amplitude regulated quantityWith CW electric current negative phase-sequence amplitude feedforward amountIt is added the set-point obtaining CW electric current negative phase-sequence amplitude

Make negative phase-sequence d axle component set-point in negative synchronous rotating frame for the CW electric currentIt is equal toCalculate CW electric current in negative phase-sequence dq Negative phase-sequence d component in coordinate systemWithDifference, using this difference as the 6th pi regulator input, the 6th pi regulator Output with negative phase-sequence d axle feedforward amount in negative synchronous rotating frame for the CW voltageIt is added, obtain CW voltage in negative phase-sequence dq coordinate Negative phase-sequence d axle set-point in system

Make negative phase-sequence q axle component set-point in negative synchronous rotating frame for the CW electric currentEqual to 0, calculate CW electric current and sit in negative phase-sequence dq Negative phase-sequence q component in mark systemWithDifference, using this difference as the 7th pi regulator input, the 7th pi regulator Output and negative phase-sequence q axle feedforward amount in negative synchronous rotating frame for the CW voltageIt is added, obtain CW voltage in negative synchronous rotating frame In negative phase-sequence q axle set-point

Finally adopt the phase place of CW negative-sequence currentWillWithTransform to abc coordinate system from negative synchronous rotating frame, obtain CW three-phase voltage negative sequence component set-point in abc coordinate systemWith

7. brushless dual-feed motor stand alone generating system excitation control method under asymmetric load according to claim 6, its It is characterised by, described CW electric current negative phase-sequence amplitude feedforward amountNegative phase-sequence d axle feedforward amount in negative synchronous rotating frame for the CW voltageWith negative phase-sequence q component in negative synchronous rotating frame for the CW electric currentComputational methods be：

$I_{2E}^{-}=\{({\mathrm{\β}}_1^{-}{i}_{1d-}^{-}+R_1{i}_{1q-}^{-})+{\[2{\mathrm{\β}}_1^{-}{R}_1{i}_{1d-}^{-}{i}_{1q-}^{-}-R_1^2{\left(i_{1d-}^{-}\right)}^2-{\left({\mathrm{\β}}_1^{-}\right)}^2{\left(i_{1q-}^{-}\right)}^2+U_1^{-*}\]}^{1/2}\}/{\mathrm{\β}}_2^{-}$

In formula,

$u_{2df-}^{-}={\mathrm{\α}}_1^{-}{i}_{2q-}^{-}+{\mathrm{\α}}_2^{-}{i}_{1d-}^{-}+{\mathrm{\α}}_3^{-}{i}_{1q-}^{-}$

In formula,

$u_{2qf-}^{-}={\mathrm{\α}}_4^{-}{i}_{2d-}^{-}+{\mathrm{\α}}_5^{-}{i}_{1d-}^{-}+{\mathrm{\α}}_6^{-}{i}_{1q-}^{-}$

In formula,

WhereinLeakage inductance coefficient for CW, ω_rFor motor speed, ω₁For PW electric voltage frequency,For CW The frequency of negative-sequence current, L_1rFor the mutual inductance between PW and rotor, L_2rFor the mutual inductance between CW and rotor, L₁Self-induction for PW, L₂ Self-induction for CW, L_rFor the self-induction of rotor, R₁Phase resistance for PW, R₂Phase resistance for CW, R_rPhase resistance for rotor；

WillWithThe expression formula transforming to abc coordinate system from negative synchronous rotating frame is：

$\left[\begin{array}{c}{u}_{2a-}^{*}\\ u_{2b-}^{*}\\ u_{2c-}^{*}\end{array}\right]=\left[\begin{array}{cc}{\mathrm{cos\θ}}_2^{-}& -{\mathrm{sin\θ}}_2^{-}\\ \cos \left({\mathrm{\θ}}_2^{-}-2\mathrm{\π}/3\right)& -\sin \left({\mathrm{\θ}}_2^{-}-2\mathrm{\π}/3\right)\\ \cos \left({\mathrm{\θ}}_2^{-}-4\mathrm{\π}/3\right)& -\sin \left({\mathrm{\θ}}_2^{-}-2\mathrm{\π}/3\right)\end{array}\right]\left[\begin{array}{c}{u}_{2d-}^{-*}\\ u_{2q-}^{-*}\end{array}\right]$

8. brushless dual-feed motor stand alone generating system excitation control method under asymmetric load according to claim 1, its It is characterised by, the CW three-phase voltage set-point in described step (6)WithIt is by the calculated CW of step (4) Three-phase voltage positive-sequence component set-point is added with step (5) calculated CW three-phase voltage negative sequence component set-point and obtains, its Expression formula is：

$\left.\begin{array}{c}{u}_{2a}^{*}=u_{2a+}^{*}+u_{2a-}^{*}\\ u_{2b}^{*}=u_{2b+}^{*}+u_{2b-}^{*}\\ u_{2c}^{*}=u_{2c+}^{*}+u_{2c-}^{*}\end{array}\right\}.$