CN115102241B - Control method and device for network-building type double-fed fan and computer readable storage medium - Google Patents

Abstract

A control method, device, and computer-readable storage medium for a network-type doubly-fed wind turbine, which relate to the field of new energy grid-connected control, and the method includes: obtaining virtual mechanical power based on grid frequency, reference frequency, and active power command value; Based on the virtual mechanical power, the virtual phase angle of the internal potential of the fan output is obtained; based on the output voltage and current of the fan, and the feedforward control value, the amplitude of the internal potential of the fan output is obtained; based on the output voltage of the fan, the amplitude of the internal potential and the virtual phase of the internal potential The stator output reference current is obtained; the excitation voltage reference wave is obtained based on the stator output reference current and the measured current on the stator and rotor side; the excitation voltage reference wave is subjected to Parker inverse transformation to obtain the PWM modulation signal of the converter. The method and device provided by the embodiments of the present invention solve the problem that the existing doubly-fed fan cannot provide independent support for voltage, frequency and inertia, so that it can provide instantaneous inertia response and have the ability of voltage regulation and frequency regulation.

Description

Control method, device and computer-readable storage medium of network-type doubly-fed fan

technical field

The present invention relates to the field of new energy grid-connected control, in particular to a control method, device and computer-readable storage medium of a grid-structured double-fed fan.

Background technique

The proposal of the goal of "carbon peak, carbon neutrality" has ushered in new developments in the field of new energy power generation. In 2021, the newly added grid-connected installed capacity of wind power in the country will be 47.57 million kilowatts; the national wind power generation will be 652.6 billion kwh. By the end of 2021, the cumulative installed capacity of wind power in the country will be 328 million kilowatts. It is estimated that my country's wind power installed capacity will reach 800 million kilowatts in 2030 and 3 billion kilowatts in 2060.

With the increase of wind power grid-connected capacity, its characteristics such as uncertainty and randomness have brought new challenges to the safe and stable operation of the power system. Doubly-fed wind turbines are one of the mainstream models in the global wind power field. The stator side is directly connected to the grid, and the rotor side is connected to the grid through back-to-back converters. The electric power can be exchanged with the grid through the stator and rotor dual channels. At present, the double-fed wind turbine mainly adopts the maximum power tracking control, and the wind speed and frequency are decoupled; the system frequency is observed through the phase-locked loop (PLL), and the response mode is passive, showing the external characteristics of the current source, which cannot provide inertia and damping response for the grid. And lack of grid voltage support capability.

Contents of the invention

In view of this, the present invention proposes a control method, device, and computer-readable storage medium of a network-type doubly-fed fan, aiming at solving the problem that the existing doubly-fed fan is a passive response and cannot provide autonomous support for voltage, frequency and inertia The problem.

In the first aspect, an embodiment of the present invention provides a control method for a network-type doubly-fed wind turbine. The method includes: obtaining grid frequency f , reference frequency f ^* , and active power command value P _ref , and based on the grid frequency f , reference frequency f ^* and active power command value P _ref , to obtain the virtual mechanical power P _m ; based on the virtual mechanical power P _m , to obtain the virtual phase angle θ of the internal potential of the fan output; to obtain the output voltage U of the fan and the output voltage of the fan Current I and the feedforward control amount, and based on the fan output terminal voltage U , the fan output terminal current I and the feedforward control amount, the fan output internal potential amplitude E _m is obtained; based on the fan output terminal voltage U , the The fan output internal potential amplitude E _m and the fan output internal potential virtual phase angle θ are used to obtain the stator output reference current; based on the stator output reference current, the stator output measured current and the rotor side measured current, through the current double-loop control, it is obtained The excitation voltage reference wave; the excitation voltage reference wave is subjected to Parker inverse transformation, and the excitation voltage reference wave in the three-phase static coordinate system is obtained as the PWM modulation signal of the converter, so as to realize the control of the switching tube of the converter .

Further, the obtaining the virtual mechanical power P _m based on the grid frequency f , the reference frequency f ^* and the active power command value P _ref includes: calculating and obtaining the virtual mechanical power P _m by using the following formula:

；

;

Among them, P _ref is the command value of active power, ΔP _ref is the output additional power value of the governor, K _p is the power-frequency static characteristic coefficient of the virtual synchronous machine, f ^* is the reference frequency, f is the grid frequency, and f _deadzone is the frequency dead zone area range.

Further, the obtaining the virtual phase angle θ of the internal potential of the fan output based on the virtual mechanical power P _m includes: calculating and obtaining the virtual phase angle θ of the internal potential of the fan output by using the following formula:

；

;

Among them, ω is the virtual angular velocity of the internal potential of the fan output, J is the virtual moment of inertia, P _m is the virtual mechanical power, P is the actual output active power of the doubly-fed fan stator, ω0 is the _rated angular velocity of the grid system, D _Equ is the equivalent virtual damping coefficient.

，并基于所述前馈控制量

和所述强制空载电动势E _qe ，得到风机输出内电势幅值E _m 。Further, the acquisition of the fan output terminal voltage U , the fan output terminal current I and the feedforward control amount, and based on the fan output terminal voltage U , the fan output terminal current I and the feedforward control amount, obtain the fan output internal potential amplitude The value E _m includes: obtaining the output terminal voltage U and the terminal current I of the fan, and based on the output terminal voltage U and the terminal current I of the fan, obtaining the forced no-load electromotive force E _qe that has a linear relationship with the excitation voltage; obtaining the feedforward control quantity

, and based on the feedforward control amount

and the forced no-load electromotive force E _qe to obtain the output internal potential amplitude E _m of the fan.

Further, the acquisition of the fan output terminal voltage U and the terminal current I , and based on the fan output terminal voltage U and the terminal current I , obtain the forced no-load electromotive force E _qe that has a linear relationship with the excitation voltage, including: using the following formula Calculate the forced no-load electromotive force E _qe that is linear with the excitation voltage:

；

;

，s为拉普拉斯算子。Among them, T _R is the time constant of the filter, U is the voltage of the fan output terminal, I is the current of the fan output terminal, R _C is the differential resistance, X _C is the differential reactance, K is the regulator gain, and K _ν is the proportional integral selection factor, T ₁ and T ₂ are the time constants of the voltage regulator, V ^* is the reference voltage of the excitation voltage regulator, V is the actual voltage of the excitation voltage regulator, j is the imaginary unit, j =

, s is the Laplacian operator.

，并基于所述前馈控制量

和所述强制空载电动势E _qe ，得到风机输出内电势幅值E _m ，包括：采用如下公式计算得到风机输出内电势幅值E _m ：Further, the acquisition of the feedforward control amount

, and based on the feedforward control amount

and the forced no-load electromotive force E _qe to obtain the output internal potential amplitude E _m of the fan, including: using the following formula to calculate the output internal potential amplitude E _m of the fan:

；

;

为虚拟励磁绕组时间常数，

为虚拟暂态电势，

为前馈控制量。Among them, E _qe is the forced no-load electromotive force with a linear relationship with the excitation voltage,

is the virtual field winding time constant,

is the virtual transient potential,

is the feedforward control quantity.

采用如下方式得到：获取实时的定子输出的d轴参考电流i _d ，并计算得到前馈控制量

；其中，x _d 为d轴同步电抗，

为d轴暂态电抗。Further, the feedforward control amount

Obtained in the following way: obtain the real-time d -axis reference current id output by the stator _, and calculate the feedforward control amount

; Among them, x _d is the d- axis synchronous reactance,

is the d- axis transient reactance.

Further, the obtaining the stator output reference current based on the fan output terminal voltage U , the fan output internal potential amplitude E _m and the fan output internal potential virtual phase angle θ includes: respectively outputting the fan output The internal potential amplitude E _m and the fan output terminal voltage U are positioned on the dq axis according to the fan output internal potential virtual phase angle θ , and the dq axis voltage component and the fan output terminal voltage of the fan output internal potential amplitude E _m are obtained The dq -axis voltage component of U ; according to the dq -axis voltage component of the fan output internal potential amplitude E _m and the dq- axis voltage component of the fan output terminal voltage U , the reference of the d -axis and q- axis output of the stator is calculated using the following formula Current:

；

;

、

为风机输出内电势幅值E _m 的d、q轴电压分量，U _d 、U _q 为风机输出端电压U的d、q轴电压分量，R、X为真实阻抗参数，R _ν 、X _ν 为虚拟阻抗参数。in,

,

are the d and q axis voltage components of the fan output internal potential amplitude E _m , U _d and U _q are the d and q axis voltage components of the fan output terminal voltage U , R and X are real impedance parameters, R _ν and X _ν are Virtual impedance parameter.

Further, the excitation voltage reference wave is obtained through current double-loop control based on the stator output reference current, the stator output measured current and the rotor side measured current, including: calculating the deviation between the stator output reference current and the stator output measured current The first PI control is performed on the rotor side reference current; the second PI control is performed on the deviation between the rotor side reference current and the rotor side measured current, and the feedforward cross decoupling term is introduced to obtain the excitation voltage reference wave.

In the second aspect, the embodiment of the present invention also provides a control device for network-type doubly-fed wind turbines. The device includes: a virtual frequency modulation controller, which is used to obtain the grid frequency f , the reference frequency f ^* , and the active power command value P _ref , and based on the grid frequency f , reference frequency f ^* and active power command value P _ref , obtain the virtual mechanical power P _m ; the virtual inertia and damping controller is used to obtain the fan output based on the virtual mechanical power P _m The internal potential virtual phase angle θ ; the virtual excitation controller is used to obtain the output terminal voltage U of the fan, the current I of the output terminal of the fan and the feedforward control amount, and based on the voltage U of the output terminal of the fan, the current I of the output terminal of the fan and the feedforward The control amount is to obtain the output internal potential amplitude E _m of the fan; the virtual circuit calculation unit is used to calculate the virtual phase angle θ based on the output terminal voltage U of the fan, the internal potential amplitude E _m of the output fan and the virtual phase angle θ of the internal potential output of the fan , to obtain the stator output reference current; the current loop control unit is used to obtain the excitation voltage reference wave through current double-loop control based on the stator output reference current, the stator output measured current and the rotor side measured current; the PWM modulation unit is used to The excitation voltage reference wave is subjected to Parker inverse transformation, and the excitation voltage reference wave in the three-phase stationary coordinate system is obtained as a PWM modulation signal of the converter, so as to realize the control of the switching tube of the converter.

Further, the obtaining the virtual mechanical power P _m based on the grid frequency f , the reference frequency f ^* and the active power command value P _ref includes: calculating and obtaining the virtual mechanical power P _m by using the following formula:

；

;

Among them, P _ref is the command value of active power, ΔP _ref is the output additional power value of the governor, K _p is the power-frequency static characteristic coefficient of the virtual synchronous machine, f ^* is the reference frequency, f is the grid frequency, and f _deadzone is the frequency dead zone area range.

Further, the virtual inertia and damping controller is also used to calculate and obtain the virtual phase angle θ of the internal potential of the fan output by using the following formula:

；

;

Among them, ω is the virtual angular velocity of the internal potential of the fan output, J is the virtual moment of inertia, P _m is the virtual mechanical power, P is the actual output active power of the doubly-fed fan stator, ω0 is the _rated angular velocity of the grid system, D _Equ is the equivalent virtual damping coefficient.

，并基于所述前馈控制量

和所述强制空载电动势E _qe ，得到风机输出内电势幅值E _m 。Further, the virtual excitation controller is also used to: obtain the output terminal voltage U and terminal current I of the fan, and based on the output terminal voltage U and the terminal current I of the fan, obtain a forced no-load that is linearly related to the excitation voltage Electromotive force E _qe ; obtain feedforward control amount

, and based on the feedforward control amount

and the forced no-load electromotive force E _qe to obtain the output internal potential amplitude E _m of the fan.

Further, the acquisition of the fan output terminal voltage U and the terminal current I , and based on the fan output terminal voltage U and the terminal current I , obtain the forced no-load electromotive force E _qe that has a linear relationship with the excitation voltage, including: using the following formula Calculate the forced no-load electromotive force E _qe that is linear with the excitation voltage:

；

;

，s为拉普拉斯算子。Among them, T _R is the time constant of the filter, U is the voltage of the fan output terminal, I is the current of the fan output terminal, R _C is the differential resistance, X _C is the differential reactance, K is the regulator gain, and K _ν is the proportional integral selection factor, T ₁ and T ₂ are the time constants of the voltage regulator, V ^* is the reference voltage of the excitation voltage regulator, V is the actual voltage of the excitation voltage regulator, j is the imaginary unit, j =

, s is the Laplacian operator.

，并基于所述前馈控制量

和所述强制空载电动势E _qe ，得到风机输出内电势幅值E _m ，包括：采用如下公式计算得到风机输出内电势幅值E _m ：Further, the acquisition of the feedforward control amount

, and based on the feedforward control amount

and the forced no-load electromotive force E _qe to obtain the output internal potential amplitude E _m of the fan, including: using the following formula to calculate the output internal potential amplitude E _m of the fan:

；

;

为虚拟励磁绕组时间常数，

为虚拟暂态电势，

为前馈控制量。Among them, E _qe is the forced no-load electromotive force with a linear relationship with the excitation voltage,

is the virtual field winding time constant,

is the virtual transient potential,

is the feedforward control quantity.

采用如下方式得到：获取实时的定子输出的d轴参考电流i _d ，并计算得到前馈控制量

；其中，x _d 为d轴同步电抗，

为d轴暂态电抗。Further, the feedforward control amount

Obtained in the following way: obtain the real-time d -axis reference current id output by the stator _, and calculate the feedforward control amount

; Among them, x _d is the d- axis synchronous reactance,

is the d- axis transient reactance.

Further, the virtual circuit calculation unit is also used for: respectively positioning the output internal potential amplitude E _m of the fan and the output terminal voltage U of the fan on the dq axis according to the virtual phase angle θ of the internal potential output of the fan , to obtain the dq axis voltage component of the fan output internal potential amplitude E _m and the dq axis voltage component of the fan output terminal voltage U ; according to the dq axis voltage component of the fan output internal potential amplitude E _m and the fan output terminal voltage U dq -axis voltage components, using the following formula to calculate the reference current of the d -axis and q- axis output by the stator:

；

;

、

为风机输出内电势幅值E _m 的d、q轴电压分量，U _d 、U _q 为风机输出端电压U的d、q轴电压分量，R、X为真实阻抗参数，R _ν 、X _ν 为虚拟阻抗参数。in,

,

are the d and q axis voltage components of the fan output internal potential amplitude E _m , U _d and U _q are the d and q axis voltage components of the fan output terminal voltage U , R and X are real impedance parameters, R _ν and X _ν are Virtual impedance parameter.

Further, the current loop control unit is also used to: perform the first PI control on the deviation between the stator output reference current and the stator output measured current to obtain the rotor side reference current; The deviation of the measured current is controlled by the second PI, and the feed-forward cross decoupling item is introduced to obtain the reference wave of the excitation voltage.

In a third aspect, an embodiment of the present invention further provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the methods provided in the foregoing embodiments are implemented.

The control method, device and computer-readable storage medium of the grid-type doubly-fed fan provided by the embodiments of the present invention obtain the virtual mechanical power P _m based on the grid frequency f , the reference frequency f ^* and the active power command value P _ref , and then based on The virtual mechanical power P _m obtains the virtual phase angle θ of the fan output internal potential, and based on the fan output terminal voltage U , the fan output terminal current I and the feedforward control value, the fan output internal potential amplitude E _m is obtained, and based on the fan output terminal voltage U , the fan output internal potential amplitude E _m and the fan output internal potential virtual phase angle θ to obtain the stator output reference current, and based on the stator output reference current, the stator output measured current and the rotor side measured current, through the current double-loop control, the excitation voltage is obtained The reference wave of the excitation voltage is reversely transformed by Parker, and the reference wave of the excitation voltage in the three-phase stationary coordinate system is obtained as the PWM modulation signal of the converter, so as to realize the control of the switching tube of the converter. A new method is proposed The doubly-fed wind turbine control method with active support capability enables doubly-fed wind turbines to provide instantaneous inertia response and have the ability to adjust voltage and frequency, which is conducive to solving the problem of safe and stable operation of new power systems with a high proportion of new energy access, effectively improving Wind energy consumption level, promote the development and utilization of wind energy.

Description of drawings

Fig. 1 shows an exemplary flow chart of a control method of a grid-type doubly-fed fan according to an embodiment of the present invention;

Fig. 2 shows an exemplary block diagram of the internal control of the grid-type converter according to an embodiment of the present invention;

Fig. 3 shows an exemplary block diagram of a current loop control according to an embodiment of the present invention;

Fig. 4 shows an exemplary block diagram of rotor-side control of a grid-type doubly-fed fan according to an embodiment of the present invention;

Fig. 5 shows a schematic structural diagram of a control device for a grid-type doubly-fed fan according to an embodiment of the present invention.

Detailed ways

Exemplary embodiments of the present invention will now be described with reference to the drawings; however, the present invention may be embodied in many different forms and are not limited to the embodiments described herein, which are provided for the purpose of exhaustively and completely disclosing the present invention. invention and fully convey the scope of the invention to those skilled in the art. The terms used in the exemplary embodiments shown in the drawings do not limit the present invention. In the figures, the same units/elements are given the same reference numerals.

Unless otherwise stated, the terms (including scientific and technical terms) used herein have the meanings commonly understood by those skilled in the art. In addition, it can be understood that terms defined by commonly used dictionaries should be understood to have consistent meanings in the context of their related fields, and should not be understood as idealized or overly formal meanings.

Fig. 1 shows an exemplary flow chart of a control method of a grid-type doubly-fed fan according to an embodiment of the present invention.

As shown in Figure 1, the method includes:

Step S101: Obtain grid frequency f , reference frequency f ^* , and active power command value P _ref , and obtain virtual mechanical power P _m based on grid frequency f , reference frequency f ^* , and active power command value P _ref .

The reference frequency f ^* and the active power command value P _ref are preset according to specific conditions.

Further, based on the grid frequency f , the reference frequency f ^* and the active power command value P _ref , the virtual mechanical power P _m is obtained, including:

Use the following formula to calculate the virtual mechanical power P _m :

；

;

Among them, P _ref is the command value of active power, ΔP _ref is the output additional power value of the governor, K _p is the power-frequency static characteristic coefficient of the virtual synchronous machine, f ^* is the reference frequency, f is the grid frequency, and f _deadzone is the frequency dead zone area range.

Fig. 2 shows an exemplary block diagram of the internal control of the grid-type converter according to the embodiment of the present invention. As shown in the part of the virtual frequency modulation controller in Figure 2, in order to realize the active response of the wind turbine to the system frequency change, simulate the power frequency static characteristics of the synchronous generator speed control system, and construct a virtual frequency modulation controller; at the same time, set the frequency change response dead zone f _deadzone , if If the absolute value of the deviation between the actual measured frequency f of the power grid and the reference frequency f ^* exceeds the set dead zone f _deadzone , the output will be based on the actual deviation, that is, P _m = P _ref + K _p ( f ^* − f ), otherwise it will be set to 0, that is, P _m = Pref _.

Step S102: Based on the virtual mechanical power P _m , obtain the virtual phase angle θ of the fan output internal potential.

Further, step S102 includes:

Use the following formula to calculate the virtual phase angle θ of the fan output internal potential:

；

;

Among them, ω is the virtual angular velocity of the internal potential of the fan output, J is the virtual moment of inertia, P _m is the virtual mechanical power, P is the actual output active power of the doubly-fed fan stator, ω0 is the _rated angular velocity of the grid system, D _Equ is the equivalent virtual damping coefficient.

Further, the equivalent virtual damping coefficient D _Equ is calculated by the following formula:

；

;

Among them, the former item D is the virtual damping coefficient, and the latter item is composed of a first-level DC blocking link and a first-level phase shifting link, which can further enhance the virtual damping control ability on the basis of D , T _w is the time constant of the DC blocking link, and T _3. T ₄ is the time constant of the phase shifting link, K _D is the magnification of the speed deviation, and s is the Laplace operator.

Fig. 2 shows an exemplary block diagram of the internal control of the grid-type converter according to the embodiment of the present invention. As shown in the part of the virtual inertia and damping controller in Figure 2, the second-order rotor motion equation of the quasi-synchronous generator adjusts the output power by adjusting the virtual mechanical power, introduces the inertia coefficient to increase the inertia characteristics in the dynamic process of power and frequency, and introduces the equivalent The virtual damping coefficient enhances the ability to suppress system power oscillations. When the actual output active power is unbalanced with the active reference value, the adjustment is realized through the inertia and damping links, and finally the virtual phase angle of the internal potential of the fan stator output is obtained.

Step S103: Obtain the fan output terminal voltage U , the fan output terminal current I and the feedforward control quantity, and obtain the fan output internal potential amplitude E _m based on the fan output terminal voltage U , the fan output terminal current I and the feedforward control quantity.

Further, step S103 includes:

Obtain the fan output terminal voltage U and terminal current I , and based on the fan output terminal voltage U and terminal current I , obtain the forced no-load electromotive force E _qe that is linearly related to the excitation voltage;

Obtain the feedforward control quantity, and based on the feedforward control quantity and the forced no-load electromotive force E _qe , obtain the fan output internal potential amplitude E _m .

Further, the output terminal voltage U and terminal current I of the fan are obtained, and based on the output terminal voltage U and the terminal current I of the fan, the forced no-load electromotive force E _qe that is linearly related to the excitation voltage is obtained, including:

Use the following formula to calculate the forced no-load electromotive force E _qe that has a linear relationship with the excitation voltage:

；

;

，s为拉普拉斯算子。Among them, T _R is the time constant of the filter, U is the voltage of the fan output terminal, I is the current of the fan output terminal, R _C is the differential resistance, X _C is the differential reactance, K is the regulator gain, and K _ν is the proportional integral selection factor, T ₁ and T ₂ are the time constants of the voltage regulator, V ^* is the reference voltage of the excitation voltage regulator, V is the actual voltage of the excitation voltage regulator, j is the imaginary unit, j =

, s is the Laplacian operator.

X _C is the differential reactance, which makes the virtual regulation control system have appropriate differential characteristics. The introduction of this differential adjustment link can prevent oscillations caused by simultaneous adjustment of a bus voltage by parallel-connected power generation equipment.

Further, the feedforward control quantity is obtained, and based on the feedforward control quantity and the forced no-load electromotive force E _qe , the output internal potential amplitude E _m of the fan is obtained, including:

Use the following formula to calculate the output internal potential amplitude E _m of the fan:

；

;

为虚拟励磁绕组时间常数，

为虚拟暂态电势，

为前馈控制量。Among them, E _qe is the forced no-load electromotive force with a linear relationship with the excitation voltage,

is the virtual field winding time constant,

is the virtual transient potential,

is the feedforward control quantity.

采用如下方式得到：Further, the feedforward control amount

Obtained as follows:

；Obtain the real-time d _- axis reference current id output by the stator, and calculate the feedforward control amount

;

为d轴暂态电抗。Among them, x _d is the d- axis synchronous reactance,

is the d- axis transient reactance.

，以反映励磁控制器支路对同步机外特性的影响。Fig. 2 shows an exemplary block diagram of the internal control of the grid-type converter according to the embodiment of the present invention. As shown in the virtual excitation controller part of Figure 2, the simulated synchronous generator adjusts the output voltage and reactive power through the differential adjustment link and the voltage control link in the excitation system. The excitation system collects the output terminal voltage and terminal current of the fan, calculates the input signal of the virtual excitation control link at this time, and performs deviation control after filtering the signal; introduces a series PID control link to maintain the same control structure as the existing synchronous machine excitation controller Consistency, easy to compare and correct with synchronous machine characteristics. At the same time, in order to more accurately simulate the transient process of the generator excitation winding, the first-order transient voltage equation of the synchronous generator is introduced, and the feedforward control quantity is added

, to reflect the influence of the excitation controller branch on the synchronous external characteristics.

Step S104: Obtain the stator output reference current based on the fan output terminal voltage U , the fan output internal potential amplitude E _m and the fan output internal potential virtual phase angle θ .

Further, step S104 includes:

The fan output internal potential amplitude E _m and the fan output terminal voltage U are positioned on the dq axis according to the fan output internal potential virtual phase angle θ , and the dq axis voltage components of the fan output internal potential amplitude E _m and the fan output terminal voltage are obtained dq axis voltage component of U ;

According to the dq- axis voltage component of the fan output internal potential amplitude E _m and the dq- axis voltage component of the fan output terminal voltage U , the reference current of the d -axis and q- axis output by the stator is calculated using the following formula:

；

;

、

为风机输出内电势幅值E _m 的d、q轴电压分量，U _d 、U _q 为风机输出端电压U的d、q轴电压分量，(R+R _ν )+j(X+X _ν )为支路总阻抗，R、X为真实阻抗参数，R _ν 、X _ν 为虚拟阻抗参数。in,

,

are the d and q axis voltage components of the fan output internal potential amplitude E _m , U _d and U _q are the d and q axis voltage components of the fan output terminal voltage U , ( R + R _ν )+ j ( X + X _ν ) is the total impedance of the branch, R and X are real impedance parameters, and R _ν and X _ν are virtual impedance parameters.

。R _ν 、X _ν 可用于限幅控制。电流限幅方法采用等比例虚拟阻抗法，R _ν 、X _ν 可采用如下方式计算得到： j is the imaginary unit, j =

. R _ν and X _ν can be used for limiting control. The current limiting method adopts the equal-proportion virtual impedance method, and R _ν and X _ν can be calculated as follows:

；

;

Among them, Idq is the actual total output current value of the _stator , that is, the current at the output terminal of the fan, and _Idqlim is the limit value of the total output current of the stator, which is determined according to the low-voltage current limit curve of the AC voltage of the system.

、

，并将风机输出端电压U按虚拟相位角θ定位于dq轴，得到电压分量U _d 、U _q 。风机端电压U与内电势

的电压差值除以总支路阻抗可计算得到定子输出的参考电流。Fig. 2 shows an exemplary block diagram of the internal control of the grid-type converter according to the embodiment of the present invention. As shown in the calculation part of the virtual circuit in Fig. 2, the virtual internal potential E _m ∠ θ is positioned on the dq axis rotating at the virtual speed, so that

,

, and the fan output terminal voltage U is positioned on the dq axis according to the virtual phase angle θ , and the voltage components U _d and U _q are obtained. Fan terminal voltage U and internal potential

The reference current output by the stator can be calculated by dividing the voltage difference by the total branch impedance.

Step S105: Based on the stator output reference current, the stator output measured current, and the rotor side measured current, through current double-loop control, an excitation voltage reference wave is obtained.

Further, step S105 includes:

Performing the first PI control on the deviation between the stator output reference current and the stator output measured current to obtain the rotor side reference current;

The second PI control is performed on the deviation between the reference current on the rotor side and the measured current on the rotor side, and the feed-forward cross decoupling term is introduced to obtain the excitation voltage reference wave.

FIG. 3 shows an exemplary block diagram of current loop control according to an embodiment of the present invention. As shown in Figure 3, the current loop control includes two parts: firstly, the deviation between the stator output reference current and the measured current is controlled by PI to obtain the reference value of the rotor side current, and then the deviation between the rotor side reference current and the measured current is calculated. PI control, and the introduction of feed-forward cross-decoupling items to obtain the excitation voltage reference wave.

Step S106: Carry out Parker inverse transformation on the excitation voltage reference wave to obtain the excitation voltage reference wave in the three-phase stationary coordinate system as a PWM modulation signal of the converter, so as to realize the control of the switching tube of the converter.

The excitation voltage reference wave under the dq axis is inversely transformed according to θ−θ _r to obtain the excitation voltage reference wave in the three-phase stationary coordinate system, and this signal is used as the PWM modulation signal of the converter to realize the switching of the converter. tube control.

What needs to be understood is that the grid-side converter of the doubly-fed wind turbine continues to adopt the traditional vector control strategy to maintain the stability of the DC bus voltage. The control method of the double-fed fan in the above steps S101-106 is specifically applied to the rotor side of the grid-type double-fed fan. Fig. 4 shows an exemplary block diagram of rotor-side control of a grid-type doubly-fed fan according to an embodiment of the present invention. As shown in Fig. 4, the rotor-side converter adopts a network-based control strategy based on the three-order practical model of the synchronous generator to set the virtual internal potential amplitude and phase angle of the DFIG to control the output active and reactive power of the DFIG. power. The rotor-side converter control mainly includes virtual frequency modulation controller, virtual inertia and damping controller, virtual excitation controller, virtual circuit calculation, current loop control and PWM generator links, etc.

In the above embodiment, the virtual mechanical power P _m is obtained based on the grid frequency f , the reference frequency f ^* and the active power command value P _ref , and then the virtual phase angle θ of the internal potential of the fan output is obtained based on the virtual mechanical power P _m , and based on the output terminal of the fan The voltage U , the current I _of the fan output terminal and the feed-forward control value are used to obtain the amplitude E m _of the internal potential of the fan output. The stator output reference current, and based on the stator output reference current, the stator output measured current and the rotor side measured current, through the current double-loop control, the excitation voltage reference wave is obtained, and the excitation voltage reference wave is subjected to Parker inverse transformation to obtain a three-phase stationary coordinate system The lower excitation voltage reference wave is used as the PWM modulation signal of the converter to control the switching tube of the converter, and a doubly-fed wind turbine control method with active support capability is proposed, so that the doubly-fed wind turbine can provide instantaneous Inertial response and the ability to regulate voltage and frequency are beneficial to solve the problem of safe and stable operation of new power systems with a high proportion of new energy access, effectively improve the level of wind energy consumption, and promote the development and utilization of wind energy.

Fig. 5 shows a schematic structural diagram of a control device for a grid-type doubly-fed fan according to an embodiment of the present invention.

As shown in Figure 5, the device includes:

The virtual frequency modulation controller 501 is used to acquire grid frequency f , reference frequency f ^* and active power command value Pref , and obtain virtual mechanical power P _m based on grid _frequency f , _reference frequency f ^* and active power command value Pref .

The reference frequency f ^* and the active power command value P _ref are preset according to specific conditions.

Further, based on the grid frequency f , the reference frequency f ^* and the active power command value P _ref , the virtual mechanical power P _m is obtained, including:

Use the following formula to calculate the virtual mechanical power P _m :

；

;

Among them, P _ref is the command value of active power, ΔP _ref is the output additional power value of the governor, K _p is the power-frequency static characteristic coefficient of the virtual synchronous machine, f ^* is the reference frequency, f is the grid frequency, and f _deadzone is the frequency dead zone area range.

Fig. 2 shows an exemplary block diagram of the internal control of the grid-type converter according to the embodiment of the present invention. As shown in the part of the virtual frequency modulation controller in Figure 2, in order to realize the active response of the wind turbine to the system frequency change, simulate the power frequency static characteristics of the synchronous generator speed control system, and construct a virtual frequency modulation controller; at the same time, set the frequency change response dead zone f _deadzone , if If the absolute value of the deviation between the actual measured frequency f of the power grid and the reference frequency f ^* exceeds the set dead zone f _deadzone , the output will be based on the actual deviation, that is, P _m = P _ref + K _p ( f ^* − f ), otherwise it will be set to 0, that is, P _m = Pref _.

The virtual inertia and damping controller 502 is configured to obtain a virtual phase angle θ of the internal electric potential output by the fan based on the virtual mechanical power P _m .

Further, the virtual inertia and damping controller 502 is also used for:

Use the following formula to calculate the virtual phase angle θ of the fan output internal potential:

；

;

Among them, ω is the virtual angular velocity of the internal potential of the fan output, J is the virtual moment of inertia, P _m is the virtual mechanical power, P is the actual output active power of the doubly-fed fan stator, ω0 is the _rated angular velocity of the grid system, D _Equ is the equivalent virtual damping coefficient.

Further, the equivalent virtual damping coefficient D _Equ is calculated by the following formula:

；

;

Among them, the former item D is the virtual damping coefficient, and the latter item is composed of a first-level DC blocking link and a first-level phase shifting link, which can further enhance the virtual damping control ability on the basis of D , T _w is the time constant of the DC blocking link, and T _3. T ₄ is the time constant of the phase shifting link, K _D is the magnification of the speed deviation, and s is the Laplace operator.

Fig. 2 shows an exemplary block diagram of the internal control of the grid-type converter according to the embodiment of the present invention. As shown in the part of the virtual inertia and damping controller in Figure 2, the second-order rotor motion equation of the quasi-synchronous generator adjusts the output power by adjusting the virtual mechanical power, introduces the inertia coefficient to increase the inertia characteristics in the dynamic process of power and frequency, and introduces the equivalent The virtual damping coefficient enhances the ability to suppress system power oscillations. When the actual output active power is unbalanced with the active reference value, the adjustment is realized through the inertia and damping links, and finally the virtual phase angle of the internal potential of the fan stator output is obtained.

The virtual excitation controller 503 is used to obtain the voltage U at the output terminal of the fan, the current I at the output terminal of the fan, and the feedforward control amount, and obtain the internal potential of the fan output based on the voltage U at the output end of the fan, the current I at the output end of the fan, and the feedforward control amount Amplitude E _m .

Further, the virtual excitation controller 503 is also used for:

Obtain the fan output terminal voltage U and terminal current I , and based on the fan output terminal voltage U and terminal current I , obtain the forced no-load electromotive force E _qe that is linearly related to the excitation voltage;

Obtain the feedforward control quantity, and based on the feedforward control quantity and the forced no-load electromotive force E _qe , obtain the fan output internal potential amplitude E _m .

Further, the output terminal voltage U and terminal current I of the fan are obtained, and based on the output terminal voltage U and the terminal current I of the fan, the forced no-load electromotive force E _qe that is linearly related to the excitation voltage is obtained, including:

Use the following formula to calculate the forced no-load electromotive force E _qe that has a linear relationship with the excitation voltage:

；

;

，s为拉普拉斯算子。Among them, T _R is the time constant of the filter, U is the voltage of the fan output terminal, I is the current of the fan output terminal, R _C is the differential resistance, X _C is the differential reactance, K is the regulator gain, and K _ν is the proportional integral selection factor, T ₁ and T ₂ are the time constants of the voltage regulator, V ^* is the reference voltage of the excitation voltage regulator, V is the actual voltage of the excitation voltage regulator, j is the imaginary unit, j =

, s is the Laplacian operator.

X _C is the differential reactance, which makes the virtual regulation control system have appropriate differential characteristics. The introduction of this differential adjustment link can prevent oscillations caused by simultaneous adjustment of a bus voltage by parallel-connected power generation equipment.

，并基于前馈控制量

和强制空载电动势E _qe ，得到风机输出内电势幅值E _m ，包括：Further, to obtain the feedforward control amount

, and based on the feedforward control amount

and the forced no-load electromotive force E _qe , to obtain the output internal potential amplitude E _m of the fan, including:

Use the following formula to calculate the output internal potential amplitude E _m of the fan:

；

;

为虚拟励磁绕组时间常数，

为虚拟暂态电势，

为前馈控制量。Among them, E _qe is the forced no-load electromotive force with a linear relationship with the excitation voltage,

is the virtual field winding time constant,

is the virtual transient potential,

is the feedforward control quantity.

采用如下方式得到：Further, the feedforward control amount

Obtained as follows:

；Obtain the real-time d _- axis reference current id output by the stator, and calculate the feedforward control amount

;

为d轴暂态电抗。Among them, x _d is the d- axis synchronous reactance,

is the d- axis transient reactance.

，以反映励磁控制器支路对同步机外特性的影响。Fig. 2 shows an exemplary block diagram of the internal control of the grid-type converter according to the embodiment of the present invention. As shown in the virtual excitation controller part of Figure 2, the simulated synchronous generator adjusts the output voltage and reactive power through the differential adjustment link and the voltage control link in the excitation system. The excitation system collects the output terminal voltage and terminal current of the fan, calculates the input signal of the virtual excitation control link at this time, and performs deviation control after filtering the signal; introduces a series PID control link to maintain the same control structure as the existing synchronous machine excitation controller Consistency, easy to compare and correct with synchronous machine characteristics. At the same time, in order to more accurately simulate the transient process of the generator excitation winding, the first-order transient voltage equation of the synchronous generator is introduced, and the feedforward control quantity is added

, to reflect the influence of the excitation controller branch on the synchronous external characteristics.

The virtual circuit calculation unit 504 is configured to obtain the stator output reference current based on the fan output terminal voltage U , the fan output internal potential amplitude E _m and the fan output internal potential virtual phase angle θ .

Further, the virtual circuit calculation unit 504 is also used for:

The fan output internal potential amplitude E _m and the fan output terminal voltage U are positioned on the dq axis according to the fan output internal potential virtual phase angle θ , and the dq axis voltage components of the fan output internal potential amplitude E _m and the fan output terminal voltage are obtained dq axis voltage component of U ;

According to the dq- axis voltage component of the fan output internal potential amplitude E _m and the dq- axis voltage component of the fan output terminal voltage U , the reference current of the d -axis and q- axis output by the stator is calculated using the following formula:

；

;

、

为风机输出内电势幅值E _m 的d、q轴电压分量，U _d 、U _q 为风机输出端电压U的d、q轴电压分量，(R+R _ν )+j(X+X _ν )为支路总阻抗，R、X为真实阻抗参数，R _ν 、X _ν 为虚拟阻抗参数。in,

,

are the d and q axis voltage components of the fan output internal potential amplitude E _m , U _d and U _q are the d and q axis voltage components of the fan output terminal voltage U , ( R + R _ν )+ j ( X + X _ν ) is the total impedance of the branch, R and X are real impedance parameters, and R _ν and X _ν are virtual impedance parameters.

。R _ν 、X _ν 可用于限幅控制。电流限幅方法采用等比例虚拟阻抗法，R _ν 、X _ν 可采用如下方式计算得到： j is the imaginary unit, j =

. R _ν and X _ν can be used for limiting control. The current limiting method adopts the equal-proportion virtual impedance method, and R _ν and X _ν can be calculated as follows:

；

;

Among them, Idq is the actual total output current value of the _stator , that is, the current at the output terminal of the fan, and _Idqlim is the limit value of the total output current of the stator, which is determined according to the low-voltage current limit curve of the AC voltage of the system.

、

，并将风机输出端电压U按虚拟相位角θ定位于dq轴，得到电压分量U _d 、U _q 。风机端电压U与内电势

的电压差值除以总支路阻抗可计算得到定子输出的参考电流。Fig. 2 shows an exemplary block diagram of the internal control of the grid-type converter according to the embodiment of the present invention. As shown in the calculation part of the virtual circuit in Fig. 2, the virtual internal potential E _m ∠ θ is positioned on the dq axis rotating at the virtual speed, so that

,

, and the fan output terminal voltage U is positioned on the dq axis according to the virtual phase angle θ , and the voltage components U _d and U _q are obtained. Fan terminal voltage U and internal potential

The reference current output by the stator can be calculated by dividing the voltage difference by the total branch impedance.

The current loop control unit 505 is used to obtain the excitation voltage reference wave through current double-loop control based on the stator output reference current, the stator output measured current and the rotor side measured current.

Further, the current loop control unit 505 is also used for:

Performing the first PI control on the deviation between the stator output reference current and the stator output measured current to obtain the rotor side reference current;

The second PI control is performed on the deviation between the reference current on the rotor side and the measured current on the rotor side, and the feed-forward cross decoupling term is introduced to obtain the excitation voltage reference wave.

FIG. 3 shows an exemplary block diagram of current loop control according to an embodiment of the present invention. As shown in Figure 3, the current loop control includes two parts: firstly, the deviation between the stator output reference current and the measured current is controlled by PI to obtain the reference current on the rotor side, and then the deviation between the reference current on the rotor side and the measured current is performed by PI Control, and introduce the feed-forward cross decoupling term to obtain the excitation voltage reference wave.

The PWM modulation unit 506 is used to inverse Parker transform the excitation voltage reference wave to obtain the excitation voltage reference wave in the three-phase stationary coordinate system as the PWM modulation signal of the converter, so as to realize the control of the switching tube of the converter.

The excitation voltage reference wave under the dq axis is inversely transformed according to θ−θ _r to obtain the excitation voltage reference wave in the three-phase stationary coordinate system, and this signal is used as the PWM modulation signal of the converter to realize the switching of the converter. tube control.

What needs to be understood is that the grid-side converter of the doubly-fed wind turbine continues to adopt the traditional vector control strategy to maintain the stability of the DC bus voltage. The control device for the doubly-fed fan mentioned above is specifically applied to the rotor side of the grid-structured doubly-fed fan. Fig. 4 shows an exemplary block diagram of rotor-side control of a grid-type doubly-fed fan according to an embodiment of the present invention. As shown in Fig. 4, the rotor-side converter adopts a network-based control strategy based on the three-order practical model of the synchronous generator to set the virtual internal potential amplitude and phase angle of the DFIG to control the output active and reactive power of the DFIG. power. The rotor-side converter control mainly includes virtual frequency modulation controller, virtual inertia and damping controller, virtual excitation controller, virtual circuit calculation, current loop control and PWM generator links, etc.

In the above embodiment, the virtual mechanical power P _m is obtained based on the grid frequency f , the reference frequency f ^* and the active power command value P _ref , and then the virtual phase angle θ of the internal potential of the fan output is obtained based on the virtual mechanical power P _m , and based on the output terminal of the fan The voltage U , the current I _of the fan output terminal and the feed-forward control value are used to obtain the amplitude E m of _the internal potential of the fan output. The stator output reference current, and based on the stator output reference current, the stator output measured current and the rotor side measured current, through the current double-loop control, the excitation voltage reference wave is obtained, and the excitation voltage reference wave is subjected to Parker inverse transformation to obtain a three-phase stationary coordinate system The lower excitation voltage reference wave is used as the PWM modulation signal of the converter to control the switching tube of the converter, and a doubly-fed wind turbine control method with active support capability is proposed, so that the doubly-fed wind turbine can provide instantaneous Inertial response and the ability to regulate voltage and frequency are beneficial to solve the problem of safe and stable operation of new power systems with a high proportion of new energy access, effectively improve the level of wind energy consumption, and promote the development and utilization of wind energy.

The embodiment of the present invention also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the method for controlling the network-type doubly-fed fan provided by the above-mentioned embodiments is realized.

The invention has been described with reference to a small number of embodiments. However, it is clear to a person skilled in the art that other embodiments than the invention disclosed above are equally within the scope of the invention, as defined by the appended patent claims.

Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise therein. All references to "a/the/the [means, component, etc.]" are openly construed to mean at least one instance of said means, component, etc., unless expressly stated otherwise. The steps of any method disclosed herein do not have to be performed in the exact order disclosed, unless explicitly stated.

Those skilled in the art should understand that the embodiments of the present invention may be provided as methods, systems or computer program products. Accordingly, the present invention can take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) having computer-usable program code embodied therein.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It should be understood that each procedure and/or block in the flowchart and/or block diagram, and a combination of procedures and/or blocks in the flowchart and/or block diagram can be realized by computer program instructions. These computer program instructions may be provided to a general purpose computer, special purpose computer, embedded processor, or processor of other programmable data processing equipment to produce a machine such that the instructions executed by the processor of the computer or other programmable data processing equipment produce a Means for realizing the functions specified in one or more steps of the flowchart and/or one or more blocks of the block diagram.

These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing apparatus to operate in a specific manner, such that the instructions stored in the computer-readable memory produce an article of manufacture comprising instruction means, the instructions The device realizes the function specified in one or more procedures of the flowchart and/or one or more blocks of the block diagram.

These computer program instructions can also be loaded onto a computer or other programmable data processing device, causing a series of operational steps to be performed on the computer or other programmable device to produce a computer-implemented process, thereby The instructions provide steps for implementing the functions specified in the flow chart flow or flows and/or block diagram block or blocks.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: the present invention can still be Any modifications or equivalent replacements that do not depart from the spirit and scope of the present invention shall fall within the protection scope of the claims of the present invention.

Claims (5)

1. A control method for network-type doubly-fed fan, characterized in that, the method comprises: Obtain grid frequency f , reference frequency f ^* and active power command value P _ref , and use the following formula to calculate virtual mechanical power P _m :

; Among them, P _ref is the command value of active power, ΔP _ref is the output additional power value of the governor, K _p is the power-frequency static characteristic coefficient of the virtual synchronous machine, f ^* is the reference frequency, f is the grid frequency, and f _deadzone is the frequency dead zone area range; Based on the virtual mechanical power P _m , the following formula is used to calculate the virtual phase angle θ of the fan output internal potential:

; Among them, ω is the virtual angular velocity of the internal potential of the fan output, J is the virtual moment of inertia, P _m is the virtual mechanical power, P is the actual output active power of the doubly-fed fan stator, ω0 is the _rated angular velocity of the grid system, D _Equ is the equivalent virtual damping coefficient; Obtain the output terminal voltage U and terminal current I of the fan, and use the following formula to calculate the forced no-load electromotive force E _qe that has a linear relationship with the excitation voltage:

; Among them, T _R is the time constant of the filter, U is the voltage of the fan output terminal, I is the current of the fan output terminal, R _C is the differential resistance, X _C is the differential reactance, K is the regulator gain, and K _ν is the proportional integral selection factor, T ₁ and T ₂ are the time constants of the voltage regulator, V ^* is the reference voltage of the excitation voltage regulator, V is the actual voltage of the excitation voltage regulator, j is the imaginary unit, j =

, s is the Laplacian operator; Obtain the real-time d _- axis reference current id output by the stator, and calculate the feedforward control amount

; Among them, x _d is the d- axis synchronous reactance,

is the d- axis transient reactance; Based on the feed-forward control amount

and the forced no-load electromotive force E _qe , use the following formula to calculate the output internal potential amplitude E _m of the fan:

; Among them, E _qe is the forced no-load electromotive force with a linear relationship with the excitation voltage,

is the virtual field winding time constant,

is the virtual transient potential,

is the feedforward control quantity; The output internal potential amplitude E _m of the fan and the output terminal voltage U of the fan are respectively positioned on the dq axis according to the virtual phase angle θ of the internal potential output of the fan output, and the dq axis voltage of the output internal potential amplitude E _m of the fan is obtained component and the dq axis voltage component of the fan output terminal voltage U ; According to the dq- axis voltage component of the internal potential amplitude E _m output by the fan and the dq- axis voltage component of the fan output terminal voltage U , the following formula is used to calculate the reference current of the d -axis and q- axis output by the stator:

; in,

,

are the d and q axis voltage components of the fan output internal potential amplitude E _m , U _d and U _q are the d and q axis voltage components of the fan output terminal voltage U , R and X are real impedance parameters, R _ν and X _ν are virtual impedance parameter; Based on the stator output reference current, the stator output measured current and the rotor side measured current, the excitation voltage reference wave is obtained through current double-loop control; The excitation voltage reference wave is subjected to Parker inverse transformation to obtain the excitation voltage reference wave in a three-phase stationary coordinate system as a PWM modulation signal of the converter, so as to realize the control of the switching tube of the converter. 2. The method according to claim 1, wherein the excitation voltage reference wave is obtained through current double-loop control based on the stator output reference current, the stator output measured current and the rotor side measured current, comprising: performing first PI control on the deviation between the stator output reference current and the stator output measured current to obtain the rotor side reference current; The second PI control is performed on the deviation between the reference current on the rotor side and the measured current on the rotor side, and a feed-forward cross decoupling term is introduced to obtain a reference wave of the excitation voltage. 3. A control device for a network-type doubly-fed fan, characterized in that the device comprises: The virtual frequency modulation controller is used to obtain the grid frequency f , reference frequency f ^* and active power command value P _ref , and use the following formula to calculate the virtual mechanical power P _m :

; Among them, P _ref is the command value of active power, ΔP _ref is the output additional power value of the governor, K _p is the power-frequency static characteristic coefficient of the virtual synchronous machine, f ^* is the reference frequency, f is the grid frequency, and f _deadzone is the frequency dead zone area range; The virtual inertia and damping controller is used to calculate the virtual phase angle θ of the internal potential of the fan output by using the following formula based on the virtual mechanical power P _m :

; Among them, ω is the virtual angular velocity of the internal potential of the fan output, J is the virtual moment of inertia, P _m is the virtual mechanical power, P is the actual output active power of the doubly-fed fan stator, ω0 is the _rated angular velocity of the grid system, D _Equ is the equivalent virtual damping coefficient; The virtual excitation controller is used to obtain the output terminal voltage U and terminal current I of the fan, and use the following formula to calculate the forced no-load electromotive force E _qe that has a linear relationship with the excitation voltage:

; Among them, T _R is the time constant of the filter, U is the voltage of the fan output terminal, I is the current of the fan output terminal, R _C is the differential resistance, X _C is the differential reactance, K is the regulator gain, and K _ν is the proportional integral selection factor, T ₁ and T ₂ are the time constants of the voltage regulator, V ^* is the reference voltage of the excitation voltage regulator, V is the actual voltage of the excitation voltage regulator, j is the imaginary unit, j =

, s is the Laplacian operator; Obtain the real-time d _- axis reference current id output by the stator, and calculate the feedforward control amount

; Among them, x _d is the d- axis synchronous reactance,

is the d- axis transient reactance; Based on the feed-forward control amount

and the forced no-load electromotive force E _qe , use the following formula to calculate the output internal potential amplitude E _m of the fan:

; Among them, E _qe is the forced no-load electromotive force with a linear relationship with the excitation voltage,

is the virtual field winding time constant,

is the virtual transient potential,

is the feedforward control quantity; The virtual circuit calculation unit is used to respectively locate the output internal potential amplitude E _m of the fan and the output terminal voltage U of the fan on the dq axis according to the virtual phase angle θ of the internal potential output of the fan to obtain the output internal potential amplitude of the fan The dq -axis voltage component of the value E _m and the dq- axis voltage component of the fan output terminal voltage U ; According to the dq- axis voltage component of the internal potential amplitude E _m output by the fan and the dq- axis voltage component of the fan output terminal voltage U , the following formula is used to calculate the reference current of the d -axis and q- axis output by the stator:

; in,

,

are the d and q axis voltage components of the fan output internal potential amplitude E _m , U _d and U _q are the d and q axis voltage components of the fan output terminal voltage U , R and X are real impedance parameters, R _ν and X _ν are virtual impedance parameter; The current loop control unit is used to obtain the excitation voltage reference wave through current double-loop control based on the stator output reference current, the stator output actual measurement current and the rotor side actual measurement current; The PWM modulation unit is used to perform Parker inverse transformation on the excitation voltage reference wave to obtain the excitation voltage reference wave in the three-phase stationary coordinate system as the PWM modulation signal of the converter, so as to realize the control of the switching tube of the converter. control. 4. The device according to claim 3, wherein the current loop control unit is also used for: performing first PI control on the deviation between the stator output reference current and the stator output measured current to obtain the rotor side reference current; The second PI control is performed on the deviation between the reference current on the rotor side and the measured current on the rotor side, and a feed-forward cross decoupling term is introduced to obtain a reference wave of the excitation voltage. 5. A computer-readable storage medium, on which a computer program is stored, wherein when the computer program is executed by a processor, the method according to any one of claims 1-2 is implemented.

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