阅读说明：本技术 风力发电机组的永磁同步发电机控制方法、装置和系统 (Permanent magnet synchronous generator control method, device and system of wind generating set ) 是由 韩振铎 刘嘉明 方杭杭 张鲁华 吴立建 于 2021-03-26 设计创作，主要内容包括：本申请提供一种风力发电机组的永磁同步发电机控制方法、装置和系统,包括：获取永磁同步发电机输出端的当前电流信息；根据当前转速信息,确定永磁同步发电机的当前电压信息；将当前电压信息和当前电流信息作为永磁同步发电机的速度观测器的输入,观测永磁同步发电机转动的角度和角速度；将角度和角速度作为永磁同步发电机的电流控制环的输入,通过旋转坐标变换得到电流控制环的反馈电流,以启动电流控制环,并将速度观测器的输入中的电压信息替换成电流控制环输出的电压参考信号,同时根据电压参考信号进行调制,使得永磁同步发电机进入被控状态；基于反馈电流,调整电流控制环的PI参数,直至反馈电流小于预设电流阈值,启动控制程序结束。(The application provides a permanent magnet synchronous generator control method, a device and a system of a wind generating set, comprising the following steps: acquiring current information of the output end of the permanent magnet synchronous generator; determining current voltage information of the permanent magnet synchronous generator according to the current rotating speed information; taking the current voltage information and the current information as the input of a speed observer of the permanent magnet synchronous generator, and observing the rotating angle and angular speed of the permanent magnet synchronous generator; taking the angle and the angular speed as the input of a current control loop of the permanent magnet synchronous generator, obtaining the feedback current of the current control loop through rotating coordinate transformation to start the current control loop, replacing the voltage information in the input of the speed observer with a voltage reference signal output by the current control loop, and modulating according to the voltage reference signal to enable the permanent magnet synchronous generator to enter a controlled state; and adjusting the PI parameter of the current control loop based on the feedback current until the feedback current is smaller than a preset current threshold, and ending the starting control program.)

1. A control method for a permanent magnet synchronous generator of a wind generating set is characterized by comprising the following steps:

when a permanent magnet synchronous generator is in an idle state, if a start instruction issued by the main control of the wind generating set and the current rotating speed information of the permanent magnet synchronous generator are received, entering a start control program of the permanent magnet synchronous generator;

the start control program includes:

acquiring current information of the output end of the permanent magnet synchronous generator;

determining the current voltage information of the permanent magnet synchronous generator according to the current rotating speed information;

using the current voltage information and the current information as the input of a speed observer of the permanent magnet synchronous generator, and observing the rotation angle and angular speed of the permanent magnet synchronous generator;

taking the angle and the angular speed as the input of a current control loop of the permanent magnet synchronous generator, obtaining feedback current used by the current control loop through rotating coordinate transformation to start the current control loop, replacing voltage information in the input of the speed observer with a voltage reference signal output by the current control loop, and modulating according to the voltage reference signal to enable the permanent magnet synchronous generator to enter a controlled state;

and adjusting the PI parameter of the current control loop based on the feedback current until the feedback current is smaller than a preset current threshold, and ending the starting control program.

2. The method of claim 1, wherein the feedback current comprises feedback currents of a direct axis d and a quadrature axis q of the permanent magnet synchronous generator.

3. The method according to claim 1, wherein the angular velocity used by the current control loop before the current control loop is started is an angular velocity obtained by filtering an angular velocity observed by the speed observer, and is updated in real time.

4. The method of claim 3, wherein the angular velocity used by the current control loop from the time the current control loop is initiated to the time the startup control routine is terminated is the filtered angular velocity of the last control cycle before the current control loop was initiated.

5. The method of claim 4, wherein the angular velocity used by the current control loop after the start-up control procedure is ended is a real-time angular velocity observed by the velocity observer.

6. The method of claim 1, wherein adjusting the PI parameter of the current control loop based on the feedback current until the feedback current is less than a preset current threshold comprises:

and adjusting the PI parameter of the current control loop based on the feedback current until the feedback current is smaller than a preset current threshold value in a preset time period.

7. The method of claim 1, wherein said adjusting the PI parameter of the current control loop comprises:

and adjusting the PI parameter of the current control loop based on a model method and/or a rule method.

8. The method of claim 1, wherein the modulation is PWM modulation.

9. The method of claim 8, further comprising:

decoupling the output voltage of a direct axis d and the output voltage of a quadrature axis q of the permanent magnet synchronous generator;

and the voltage reference signal is determined based on the output voltage of the direct axis d and the output voltage of the quadrature axis q after decoupling.

10. The method of claim 1, further comprising:

the angular velocity is used as a feed-forward input to a PI regulator of the current control loop.

11. The method of claim 1, wherein after the end of the startup control procedure, further comprising:

in the controlled state, the current control loop is controlled based on an external given torque.

12. The method of claim 1, wherein the velocity observer observes the angle and the angular velocity based on at least one of the following algorithms:

a phase-locked loop algorithm, a model reference adaptive method, a slip film observer method, a mathematical model state observer method, an adaptive observer method, and an extended Kalman filter method.

13. The method of claim 1, wherein the start-up command and the current speed information are issued by the master controller upon determining that the speed of the wind turbine is between a minimum cut-in speed and a maximum cut-out speed of the wind turbine.

14. The method of claim 1, wherein the present current information is obtained based on current sensor detection on the permanent magnet synchronous generator.

15. Method according to claim 1 or 14, characterized in that the present current information is an effective, instantaneous or average value of the present current of the permanent magnet synchronous generator in the idling state.

16. A control device for a permanent magnet synchronous generator of a wind power plant, comprising one or more processors for implementing the method according to any of claims 1-15.

17. A permanent magnet synchronous generator control system of a wind power plant comprising a master control and a permanent magnet synchronous generator control device according to claim 16, the master control being electrically connected to a processor of the permanent magnet synchronous generator control device.

18. A computer-readable storage medium, having stored thereon a program which, when executed by a processor, carries out the method of any one of claims 1-15.

Technical Field

The application relates to the field of wind generating sets, in particular to a method, a device and a system for controlling a permanent magnet synchronous generator of a wind generating set.

Background

Currently, in the face of increasingly severe ecological and environmental crisis, the vigorous development of wind power has gradually become a key support for realizing the goals of green low-carbon development and ecological civilization construction. At present, offshore wind power resources are relatively abundant, and the offshore wind power resources have large potential development amount, so that the offshore wind power resources are widely concerned by researchers and enterprises. The permanent magnet synchronous generator is used as a key component of an offshore direct-drive wind permanent magnet synchronous generator set, the control of the permanent magnet synchronous generator is generally in a rotor-oriented space vector modulation mode, the control mode needs to use rotor angle information to carry out coordinate transformation, and finally dq axis independent control of a current control loop is achieved. The central axis of the N pole of the magnetic field generated by the rotor magnetic pole of the permanent magnet synchronous generator is taken as a direct axis d, and the position which leads the direct axis by 90 degrees of electric angle is defined as a quadrature axis q.

The conventional method for acquiring the rotor angle information is to acquire related information through a speed encoder arranged on a permanent magnet synchronous generator, but the operating condition of the wind generating set is considered to be severe, the fault rate of the speed encoder is high, the generating efficiency of the wind generating set is greatly influenced, and the operation and maintenance cost is increased. In order to solve the problem, a relatively mature speed-sensorless control mode is applied to control of the permanent magnet synchronous generator. The current mainstream speed observer needs to use the terminal voltage information of the permanent magnet synchronous generator during the startup of the permanent magnet synchronous generator, which needs to install a voltage sensor at the end of the permanent magnet synchronous generator to obtain the terminal voltage information of the permanent magnet synchronous generator. However, as the permanent magnet synchronous generator is gradually applied to the sea, the failure rate of the voltage sensor is increased sharply due to the severe sea wind field environment, and the sea operation and maintenance cost is increased.

Disclosure of Invention

The application provides a permanent magnet synchronous generator control method, device and system of a wind generating set.

Specifically, the method is realized through the following technical scheme:

according to a first aspect of embodiments of the present application, there is provided a method for controlling a permanent magnet synchronous generator of a wind turbine generator system, the method including:

when a permanent magnet synchronous generator is in an idling state, if a start instruction issued by the main control of the wind generating set and the current rotating speed information of the permanent magnet synchronous generator are received, entering a start control program of the permanent magnet synchronous generator;

the start control program includes:

acquiring current information of the output end of the permanent magnet synchronous generator;

determining the current voltage information of the permanent magnet synchronous generator according to the current rotating speed information;

using the current voltage information and the current information as the input of a speed observer of the permanent magnet synchronous generator, and observing the rotation angle and angular speed of the permanent magnet synchronous generator;

taking the angle and the angular speed as the input of a current control loop of the permanent magnet synchronous generator, obtaining feedback current used by the current control loop through rotating coordinate transformation to start the current control loop, replacing voltage information in the input of the speed observer with a voltage reference signal output by the current control loop, and modulating according to the voltage reference signal to enable the permanent magnet synchronous generator to enter a controlled state;

and adjusting the PI parameter of the current control loop based on the feedback current until the feedback current is smaller than a preset current threshold, and ending the starting control program.

Optionally, the feedback current comprises feedback currents of a direct axis d and a quadrature axis q of the permanent magnet synchronous generator.

Optionally, before the current control loop is not started, the angular velocity used by the current control loop is an angular velocity obtained by filtering the angular velocity observed by the speed observer, and is updated in real time.

Optionally, from the time when the current control loop is started to the time when the start control program is ended, the angular velocity used by the current control loop is the filtered angular velocity of the latest control period before the current control loop is started.

Optionally, after the start-up control procedure is ended, the angular velocity used by the current control loop is a real-time angular velocity observed by the velocity observer.

Optionally, the adjusting the PI parameter of the current control loop based on the feedback current until the feedback current is smaller than a preset current threshold includes:

and adjusting the PI parameter of the current control loop based on the feedback current until the feedback current is smaller than a preset current threshold value in a preset time period.

Optionally, the adjusting the PI parameter of the current control loop includes:

and adjusting the PI parameter of the current control loop based on a model method and/or a rule method.

Optionally, the modulation is PWM modulation.

Optionally, the method further comprises:

decoupling the output voltage of a direct axis d and the output voltage of a quadrature axis q of the permanent magnet synchronous generator;

and the voltage reference signal is determined based on the output voltage of the direct axis d and the output voltage of the quadrature axis q after decoupling.

Optionally, the method further comprises:

using the angular velocity as a feed-forward input to a PI regulator of the current control loop;

optionally, after the starting control procedure is ended, the method further includes:

in the controlled state, the current control loop is controlled based on an external given torque.

Optionally, the speed observer determines the angle and the angular velocity based on at least one of the following algorithms:

a phase-locked loop algorithm, a model reference adaptive method, a slip film observer method, a mathematical model state observer method, an adaptive observer method, and an extended Kalman filter method.

Optionally, the start instruction and the current rotation speed information are issued by the master controller when it is determined that the rotation speed of the wind generating set is between the minimum cut-in speed and the maximum cut-out speed of the wind generating set.

Optionally, the current information is obtained based on detection of a current sensor on the permanent magnet synchronous generator.

Optionally, the current information is an effective value, an instantaneous value or an average value of the current of the permanent magnet synchronous generator in the idling state.

According to a second aspect of embodiments of the present application, there is provided a permanent magnet synchronous generator control device of a wind turbine generator set, comprising one or more processors for implementing the method of any one of the first aspect.

According to a third aspect of the embodiments of the present application, there is provided a permanent magnet synchronous generator control system of a wind generating set, comprising a main control and the permanent magnet synchronous generator control device of the second aspect, wherein the main control is electrically connected with a processor of the permanent magnet synchronous generator control device.

According to a fourth aspect of embodiments herein, there is provided a computer readable storage medium having a program stored thereon, which when executed by a processor, implements the method of any one of the first aspects.

According to the technical scheme provided by the embodiment of the application, in the idle state of the permanent magnet synchronous generator, the permanent magnet synchronous generator can enter a starting control program of the permanent magnet synchronous generator according to a starting instruction issued by a main controller and the current rotating speed information of the permanent magnet synchronous generator, in the process of starting the control program, the current voltage information of the permanent magnet synchronous generator can be determined according to the current rotating speed information, and then the current information of the output end of the permanent magnet synchronous generator is obtained, so that a speed observer can observe the angle and the angular speed of the permanent magnet synchronous generator and then input a current control loop, the feedback current used by the current control loop is obtained through rotating coordinate transformation, and the current control loop is started, the voltage information input by the speed observer is replaced by a voltage reference signal output by the current control loop, and modulation output is started at the same time, so that the permanent magnet synchronous generator, and adjusting the current inner loop PI parameter based on the feedback current to form a self-closed loop observation system for real-time adjustment, ensuring accurate observed angle and ensuring stable operation of the system.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and together with the description, serve to explain the principles of the application.

FIG. 1 is a system block diagram of a permanent magnet synchronous generator side control algorithm of a wind generating set for starting a permanent magnet synchronous generator and controlling operation;

FIG. 2 is a flow chart diagram illustrating a method of controlling a permanent magnet synchronous generator according to an exemplary embodiment of the present application;

FIG. 3 is a flow chart illustrating a master control according to an exemplary embodiment of the present application;

FIG. 4 is a flow chart diagram illustrating a permanent magnet synchronous generator start control routine according to an exemplary embodiment of the present application;

FIG. 5 is a schematic diagram illustrating a virtual to real position of a d-axis according to an exemplary embodiment of the present application;

FIG. 6 is a block diagram of a permanent magnet synchronous generator control system according to an exemplary embodiment of the present application;

fig. 7 is a block diagram illustrating a configuration of a permanent magnet synchronous generator control device of a wind turbine generator system according to an exemplary embodiment of the present application.

Detailed Description

Fig. 1 is a system diagram of a permanent magnet synchronous generator side control algorithm of a wind turbine generator system for starting a permanent magnet synchronous generator and controlling operation, wherein a current sensor is used for detecting phase current information of an output end of the permanent magnet synchronous generator, a voltage sensor is used for detecting line voltage information, the detected current information and the detected voltage information are sent to a speed observer, and the speed observer estimates a current angle and current angular speed information of the permanent magnet synchronous generator according to the detected voltage information and the detected current information. During the whole starting process, if the voltage sensor fails, the whole system can be failed to start. In FIG. 1, i is_abcIs permanent magnet synchronous generator port ABC three-phase instantaneous phase current u_abcIs a permanent magnet synchronous generator port ABC three-phase instantaneous line voltage,andcurrent command values (i.e., target currents) i in two-phase rotation coordinate axes_dAnd i_qThe current feedback values (i.e. feedback currents) are respectively obtained under the two-phase rotation coordinate axes, and ω and θ are respectively the angular speed and the angle of the permanent magnet synchronous generator. Aiming at the problem that the reliability of the whole system is influenced by the fault of the voltage sensor at present, the conventional processing mode is to temporarily stop the operation of the unit, and the voltage sensor is replaced by operation and maintenance workers, but the whole replacement process can bring great economic loss.

In view of the above, the method, the apparatus, and the system for controlling a permanent magnet synchronous generator of a wind turbine generator system according to the embodiments of the present application can enter a start control program of the permanent magnet synchronous generator according to a start instruction issued by a main controller and current rotation speed information of the permanent magnet synchronous generator in an idle state of the permanent magnet synchronous generator, and during the start control program, current voltage information of the permanent magnet synchronous generator can be determined according to the current rotation speed information, and current information of an output end of the permanent magnet synchronous generator is obtained, so that a speed observer can observe an angle and an angular velocity of the permanent magnet synchronous generator, then the current control loop is input, a feedback current used by the current control loop is obtained through rotation coordinate transformation, so as to start the current control loop, and the voltage information input by the speed observer is replaced by a voltage reference signal output by the current control loop, the method comprises the steps of starting modulation output simultaneously, enabling the permanent magnet synchronous generator to enter a controlled state, adjusting current inner ring PI parameters based on feedback current, forming a self-closed loop observation system to conduct real-time adjustment, ensuring accurate observed angles, and guaranteeing stable operation of the system.

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in this application and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and/or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

It is to be understood that although the terms first, second, third, etc. may be used herein to describe various information, such information should not be limited to these terms. These terms are only used to distinguish one type of information from another. For example, first information may also be referred to as second information, and similarly, second information may also be referred to as first information, without departing from the scope of the present application. The word "if" as used herein may be interpreted as "at … …" or "when … …" or "in response to a determination", depending on the context.

The following describes a method, an apparatus, and a system for controlling a permanent magnet synchronous generator of a wind turbine generator system in detail with reference to the accompanying drawings. The features of the following examples and embodiments may be combined with each other without conflict.

The embodiment of the application provides a control method of a permanent magnet synchronous generator of a wind generating set, and an execution main body of the control method of the permanent magnet synchronous generator of the wind generating set of the embodiment of the application can be a machine side controller of the permanent magnet synchronous generator and can also be an independent controller arranged on the permanent magnet synchronous generator.

Referring to fig. 2, the method may include:

and S11, when the permanent magnet synchronous generator is in an idle state, if a start instruction issued by the main control of the wind generating set and the current rotating speed information of the permanent magnet synchronous generator are received, entering a start control program of the permanent magnet synchronous generator.

The start instruction and the current rotation speed information can be issued by the master controller when the rotation speed of the wind generating set (herein, referred to as the fan rotation speed) is determined to be between the minimum cut-in speed and the maximum cut-out speed of the wind generating set, namely, the master controller issues the start instruction and the current rotation speed information to the permanent magnet synchronous generator when the rotation speed of the fan is determined to be greater than the minimum cut-in speed and less than the maximum cut-out speed, so that the safe start of the wind generating set is ensured. Optionally, the rotation speed of the wind turbine is determined based on wind speed information of the wind turbine generator system monitored by a wind speed sensor (e.g., an anemometer), and the wind speed sensor may be disposed on an outer sidewall of a tower of the wind turbine generator system, may also be disposed at another position of the wind turbine generator system, or may also be disposed in a surrounding area of the wind turbine generator system instead of the wind turbine generator system.

In other embodiments, the master control issues the start instruction and the current rotation speed information to the permanent magnet synchronous generator under the instruction of the user, for example, the user presses a start button of the wind turbine generator set under the condition that the user ensures that the wind turbine generator set can be started safely, so as to instruct the master control to issue the start instruction to the permanent magnet synchronous generator.

Referring to fig. 3, in a possible embodiment, the master control includes the following steps:

(1) the motor is in an idling state, the wind speed information of the wind generating set is monitored based on the anemoscope, the rotating speed of the fan is determined according to the wind speed information, and the rotating speed information of the motor is obtained through a speed sensor installed on the permanent magnet synchronous generator.

(2) Judging whether the current start-up requirement is met or not according to the minimum cut-in speed and the maximum cut-out speed; specifically, when the rotating speed of the fan is greater than the minimum cut-in speed and less than the maximum cut-out speed, the requirement for starting the fan is met, otherwise, the requirement for starting the fan is not met.

(3) If not, continuing waiting; and if so, issuing a starting instruction and current rotating speed information to the permanent magnet synchronous generator, and simultaneously issuing the rotating speed information to the permanent magnet synchronous generator.

The current rotating speed information is obtained by the main control through the detection of a speed sensor on the permanent magnet synchronous generator, and can also be obtained by other modes, such as big data training. It should be understood that the accuracy of the current rotation speed information of the embodiment of the present application may not need to be too high, and thus the hardware cost may be reduced. Referring to fig. 4, the start control procedure of the permanent magnet synchronous generator may include the following steps:

and S111, acquiring current information of the output end of the permanent magnet synchronous generator.

The current information of the embodiment of the application is obtained based on the detection of the current sensor on the permanent magnet synchronous generator, and the embodiment of the application does not specifically limit the type of the current sensor. The current information is an effective value, an instantaneous value or an average value of the current of the permanent magnet synchronous generator in an idling state.

And S112, determining the current voltage information of the permanent magnet synchronous generator according to the current rotating speed information.

The current voltage information is determined based on the current rotating speed information, and the current voltage information can be determined in the existing mode, which is not limited in the embodiment of the application.

Step S111 and step S112 may be executed simultaneously or sequentially, for example, step S111 is executed first, and then step S112 is executed, or step S112 is executed first, and then step S111 is executed.

And S113, taking the current voltage information and the current information as the input of a speed observer of the permanent magnet synchronous generator, and observing the rotating angle and the angular speed of the permanent magnet synchronous generator.

The velocity observer may observe the angle and angular velocity based on at least one of the following algorithms: a phase-locked loop algorithm, a model reference adaptive method, a slip film observer method, a mathematical model state observer method, an adaptive observer method, and an extended Kalman filter method. Of course, the speed observer may also adopt other algorithms to observe the angle and the angular speed.

S114, the angle and the angular speed are used as the input of a current control loop of the permanent magnet synchronous generator, the feedback current used by the current control loop is obtained through rotating coordinate transformation, the current control loop is started, the voltage information in the input of the speed observer is replaced by a voltage reference signal output by the current control loop, and modulation is carried out according to the voltage reference signal, so that the permanent magnet synchronous generator enters a controlled state.

To this end, a self-closed loop control system is formed.

The feedback current can comprise the feedback current of a direct axis d and a quadrature axis q of the permanent magnet synchronous generator, and the accuracy of PI parameter adjustment of a current control loop is improved; it should be understood that the feedback current may also comprise only the feedback current of the direct axis d or the feedback current of the quadrature axis q.

The present embodiment includes feedback currents of the direct axis d and the quadrature axis q of the permanent magnet synchronous generator as feedback currents, so that the coordinate transformation in step S114 is dq coordinate transformation.

Optionally, the angle used for dq coordinate transformation in the current control loop is in the permanent magnet flux linkage psi_fThe angle of d-axis orientation, see FIG. 5, is the permanent magnet flux linkage psi_fTrue position d of_actualIncluded angle theta between the permanent magnet synchronous generator and the A phase_actual. In FIG. 5, d_masterTo rotate the virtual position of the d-axis, d_actualFor true position of the rotating d-axis, q_masterFor virtual positions of the rotating d-axis, q_actualThe true position of the rotating d-axis.

Alternatively, referring to fig. 6, the modulation in step S114 is PWM modulation, and the voltage reference signal after PWM modulation is input to the permanent magnet synchronous generator through the converter, so that the permanent magnet synchronous generator enters a controlled state. It should be understood that the modulation in step S114 may be other signal modulation methods.

And S115, adjusting the PI parameter of the current control loop based on the feedback current until the feedback current is smaller than a preset current threshold, and ending the starting control program.

Target current of the current control loop (i.e. in fig. 6) when the motor is in no-load condition) The magnitude is 0, and ideally, the feedback current (i.e. i in FIG. 6)_q、i_d) Also 0. Although the amplitude and the frequency of the current voltage information of the adopted permanent magnet synchronous generator in the idling state are accurate, a fixed phase difference may exist between the current voltage information of the permanent magnet synchronous generator in the idling state and the real voltage information of the permanent magnet synchronous generator in the idling state, the phase difference is finally reflected to an angle error, and the angle error and the current error of the current control loop have a corresponding relation, so that the embodiment of the application adjusts the current control loop based on the feedback currentAnd (4) the PI parameter, until the feedback current is less than the preset current threshold, gradually eliminating the current error of the current control loop, thereby ensuring the accuracy of the observation angle of the speed observer and ensuring the stable operation of the system. And if the feedback current is smaller than the preset current threshold, the starting of the speed observer and the current control loop is finished, and if the feedback current is not met, the adjustment is continued. In the starting process of the permanent magnet synchronous generator, the machine side controller only needs to know the current motor rotating speed information (the precision is not high), and the subsequent angular speed and angle form a self-closed loop control system through adjusting a speed observer and a current control loop to automatically correct.

The preset current threshold may be a value close to 0, and the size of the preset current threshold may be set as required.

In an exemplary embodiment, referring to fig. 5 and 6, a permanent magnet synchronous generator may include the steps of:

(1) receiving a start-up instruction from the master control and receiving current rotating speed information (n) sent by the master control_mast_er) When the motor is in an idle uncontrolled state (namely an idle state);

(2) n issued according to the master control_mast_erThe motor parameters and the interruption execution time of the controller of the permanent magnet synchronous generator to obtain the current voltage information u at the end of the permanent magnet synchronous generator_mast_erAnd before the permanent magnet synchronous generator is started, a speed observer is used for observing and obtaining the angle and the angular speed of the motor at the moment based on the current voltage information and the current information.

The angle used for dq coordinate transformation in the control loop is phi in the permanent magnet flux linkage_fAngle of d-axis orientation, the angle being the permanent magnet flux linkage psi_fCurrent position d of_actualIncluded angle theta between the permanent magnet synchronous generator and the A phase_actual. When the speed observer adopts u_masterObtaining angle θ as voltage information_masterAnd angular velocity ω_masterOf angular velocity ω therein_masterTo be accurate, and the angle theta_masterAs virtual anglesDegree of angle theta_actualThe phase difference is fixed, but the two rotate with the same frequency space, which is mainly because although the amplitude and frequency of the adopted voltage information are accurate, there may exist a fixed phase difference with the real voltage information, and the phase difference is finally reflected to the angle error by the following expression:

θ_error＝θ_master-θ_actual (1)；

wherein, theta_errorIs an angle error.

Angle error theta_errorHas a large influence on the control performance of the permanent magnet synchronous generator when the range of the angle theta is different_errorSmaller, if theta is used_masterThe angle used for coordinate transformation in the current control loop can cause the reduction of control efficiency and the increase of the total current amplitude; when theta is_errorWhen the current is large, the operation condition of the permanent magnet synchronous generator is further severe, so that the controller of the permanent magnet synchronous generator is diffused.

Due to the above-mentioned theta_errorInfluence the control performance of the motor, and when the method is actually used, the theta is obtained_masterIt cannot be used directly. From the above, it can be known that if a constant error value θ between the virtual angle and the real angle is set_errorAnd the control requirement can be met when the value is reduced to 0.

(3) Starting a current control loop and converting the voltage information in the input of the speed observer by u_mast_erSwitching to a voltage reference signal output by a current control loopAlpha and beta are coordinate axis indicators of two-phase static coordinate axes, PWM modulation is started at the same time, the permanent magnet synchronous generator starts to be in a controlled state, and a port current sensor of the permanent magnet synchronous generator detects three-phase current in real time and inputs the three-phase current into a speed observer. At this time, the angle information observed by the speed observer is theta_masterApproaches to theta_actualAngle of transition of (theta)_transitUsing theta_transitConverting three-phase current into three-phase current as input angle of coordinate transformationAnd d, converting into a dq-axis current in a rotating coordinate system as feedback of a current control loop. At this point, the entire startup closed loop process is established.

The method comprises the steps of firstly receiving a start instruction and current rotating speed information issued by a master controller, converting the received current rotating speed information into current voltage information and sending the current voltage information into a speed observer by a permanent magnet synchronous generator, receiving the current information detected by a current sensor by the speed observer, applying an observed angle and an observed angular speed to a current control loop, starting the current control loop, replacing the voltage information in the input of the speed observer with voltage reference signal input output by the current control loop, simultaneously starting PWM (pulse width modulation), starting the permanent magnet synchronous generator to be in a controlled state, observing a system in a closed loop mode, adjusting PI (proportional integral) parameters based on feedback current, ensuring correct observed angle, and finally ensuring stable operation of the system.

In step S115, the PI parameter of the current control loop is adjusted based on the feedback current until the feedback current is smaller than the preset current threshold, and it may be determined whether the feedback current at a certain time is smaller than the preset current threshold, or whether the feedback current in a certain time period is smaller than the preset current threshold.

Illustratively, the PI parameter of the current control loop is adjusted based on the feedback current until the feedback current is less than the preset current threshold for a preset time period. And in a preset time period, the feedback current is smaller than a preset current threshold value, which indicates that the system stably operates. The preset time period may be set as desired, such as 1 second or other time period.

In some embodiments, the angular velocity used by the current control loop is updated in real time before the current control loop is not started, which may be the angular velocity observed by the velocity observer, i.e. the angular velocity observed by the velocity observer is directly taken as the angular velocity used by the current control loop without any processing of the angular velocity observed by the velocity observer. Further, the angular velocity used by the current control loop may also be an angular velocity obtained by filtering the angular velocity observed by the speed observer before the current control loop is not started. Before the current control loop is started, the angle observed by the speed observer is a dynamic transition angle, and the angular velocity fluctuation is large, so that the angular velocity observed by the speed observer before the current control loop is started is filtered, and the angular velocity obtained through filtering is used as the angular velocity used by the current control loop, so that the accuracy of the angular velocity used by the current control loop can be improved.

Further, from the time when the current control loop is started to the time when the start control procedure is ended (this time period may also be referred to as a closed-loop regulation phase), the angular velocity used by the current control loop is the filtered angular velocity of the latest control period before the current control loop is started. In the closed-loop regulation stage, the whole system is not stable, so that the angular speed observed by a speed observer is frozen, and the accuracy of the angular speed used by a current control loop in the closed-loop regulation stage is ensured. The control period may be an interrupt control period of the machine-side controller, or may be an integral multiple of a middle-end control period of the machine-side controller.

Further, after the start-up control routine is ended, the angular velocity used by the current control loop is the real-time angular velocity observed by the velocity observer, and after the start-up control routine is ended, the entire system is in a stable state, so that after the start-up control routine is ended, the accuracy of the angular velocity used by the current control loop after the start-up control routine is ended is ensured by using the real-time angular velocity observed by the velocity observer as the angular velocity used by the current control loop.

Before the closed-loop regulation of the starting current control loop is started, because the observed angle is a dynamic transition angle and the angular velocity fluctuation is large, the angular velocity observed before the current closed loop is filtered by using the filter to obtain the angular velocity omega after filtering_{master_filter}Closed loop start while freezing the angular velocity observed by the speed observer, using ω obtained by previous filtering_{master_filter}As an input to the current control loop. When the closed-loop regulation is finished, the whole system is in a stable state at the moment, and then the angular speed omega observed by the speed observer is used_actualAs the actual angular velocity into the current control loop.

Starting closed loop regulationAfter the process, because the angle has an error, a larger moment generated by a larger instantaneous current can be generated at the moment to pull the virtual angle to the actual angle, and larger instantaneous current impact can generate larger damage to the permanent magnet synchronous generator, so that in order to reduce the instantaneous current amplitude in the closed-loop regulation process and shorten the regulation time, the PI parameter of the current control ring is subjected to online self-setting to accelerate the closed-loop regulation process and quickly adjust the angle error theta_errorThe reduction is 0.

The embodiment of the application can adjust the PI parameter of the current control loop based on a model method and/or a rule method, and also can adjust the PI parameter of the current control loop based on other modes. The model method and the rule method can adopt the existing model method and rule method.

Optionally, in some embodiments, the method further comprises: decoupling the output voltage of the direct axis d and the output voltage of the quadrature axis q of the permanent magnet synchronous generator, and further improving the system stability by decoupling the coupling relation between the output voltage of the direct axis d and the output voltage of the quadrature axis q; the voltage reference signal is determined based on the output voltage of the direct axis d and the output voltage of the quadrature axis q after decoupling. Specifically, referring to FIG. 6, the output voltage based on the decoupled direct axis dOutput voltage of sum quadrature axis qDetermining current control loop output voltageThe voltage of the output end of the current control loop under the two-phase rotation coordinate axis; based onAnd determining the voltage of the output end of the current control loop under the two-phase static coordinate axis, namely the voltage reference signal. In FIG. 6, i represents_αAnd i_βCurrent inversions in two-phase stationary coordinate axesThe value of the feedback is fed back to the device,andrespectively are voltage command values under two static coordinate axes,andthe voltage instruction values are respectively under two-phase rotation coordinate axes.

Optionally, in some embodiments, the method further comprises: the angular speed is used as the feedforward input of the PI regulator of the current control loop, so that the dynamic property of the permanent magnet synchronous generator is ensured, and the burden of the PI regulator is reduced.

Optionally, the method further comprises: in the controlled state, the current control loop is controlled based on the given torque of the outside, and at this time, the system is normally operated. The external given torque can be issued by the main control instructed by the user or automatically issued by the main control.

In the embodiment of the present application, the current control loop in the start control procedure of the permanent magnet synchronous generator is a current inner loop. When the controlled state is entered, the current outer ring is composed of a torque/power outer ring and is controlled.

In a feasible embodiment, the speed observer is selected as a slip film observer method, the rotating speed is considered to be slow, and a mathematical model of the speed observer is simplified as follows:

in the formula (2), the reaction mixture is,respectively in the form of the differential of current to time in a stationary coordinate system;

i_α、i_βand u_α、u_βRespectively current and voltage under a static coordinate system;

L_qand R_sThe q-axis inductor and the stator resistor of the permanent magnet synchronous generator are respectively;

e_αand e_βTo extend the back emf.

The mathematical expression of the synovial observer was established as follows:

in the formula (3), the reaction mixture is,respectively in the form of the differential of the current estimation value to time under a static coordinate system;

andrespectively current estimated values under a static coordinate system;

sgn () represents a sign function;

k is the synovial membrane gain.

According to the synovial equivalent control theory, the extended back electromotive force can be obtained:

wherein the content of the first and second substances,is a low-pass filter;

ω_cthe cut-off frequency of the low-pass filter.

And obtaining a rotor position angle theta by adopting an arc tangent function, and further differentiating the angle to obtain an angular velocity omega.

As can be seen from the above analysis of the synovial membrane observer, all the variables used above are variables in the stationary coordinate system. According to n issued by the master control_masterMotor parameter (by motor permanent magnet flux linkage parameter psi)_fFor example) and control period T of a controller of a permanent magnet synchronous generator_sampleObtaining the voltage u of the permanent magnet synchronous generator terminal under the static coordinate system_{α_master}And u_{β_master}The expression is as follows:

θ_masterthe value of the angle at the time k is represented, and according to the relation between the angle and the angular speed, the angle can be obtained by integrating the angular speed, and the expression is as follows:

and the speed observer combines the obtained voltage information, current information and motor parameters to obtain an angle and an angular speed.

Starting a current control loop and outputting a PWM modulation wave, and inputting voltage information of a speed observer by u_{α_master}And u_{β_master}Switching to current control loop output voltage command informationAndthe permanent magnet synchronous generator starts to be in a controlled state, and the port current sensor of the permanent magnet synchronous generator detects three-phase current in real time and inputs the three-phase current into the speed observer. At this time, the angle information observed by the speed observer is theta_masterApproaches to theta_actualAngle of transition of (theta)_transitUsing theta_transitAs an input angle of coordinate transformation, converting three-phase current into dq-axis current in a rotating coordinate system as current controlFeedback of the loop. At this point, the entire startup closed loop process is established.

When the permanent magnet synchronous generator is in an idling state, the current information is comprehensively analyzed, and the example takes a q-axis current sliding average value under a rotating coordinate system as an example:

in the formula (7), k represents the current k time, k-N represents N times before the k time, N is a positive integer, i_{q_k}Q-axis feedback current signal, i, representing the current time k_{q_aver}The average of its N samples is shown.

Real-time comparison of i_{q_aver}And a predetermined current threshold i_{q_error}When i is_{q_aver}After being less than a predetermined current threshold, the angle error theta is specified_errorAnd the temperature is reduced to be near 0, the thawing speed observes the observed angular speed, and the speed observer and the current inner loop are started.

After the angle and the angular speed are adjusted, the current outer ring is started to receive external given torque, the whole process is started, and the system operates normally.

Referring to fig. 7, an embodiment of the present application further provides a permanent magnet synchronous generator control device of a wind turbine generator system, including one or more processors, for implementing the method according to any one of the first aspect.

The embodiment of the permanent magnet synchronous generator control device can be applied to a wind generating set. The device embodiments may be implemented by software, or by hardware, or by a combination of hardware and software. The software implementation is taken as an example, and as a device in a logical sense, a processor of the wind turbine generator set where the device is located reads corresponding computer program instructions in the nonvolatile memory into the memory for operation. In terms of hardware, as shown in fig. 7, the present application is a hardware structure diagram of a wind turbine generator system in which a permanent magnet synchronous generator control device is located, except for the processor, the internal bus, the memory, the network interface, and the nonvolatile memory shown in fig. 7, the wind turbine generator system in which the device is located in the embodiment may also include other hardware according to the actual function of the wind turbine generator system, which is not described again.

The Processor may be a Central Processing Unit (CPU), other general purpose Processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other Programmable logic device, discrete Gate or transistor logic device, discrete hardware component, etc. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

The embodiment of the application also provides a permanent magnet synchronous generator control system of the wind generating set, which comprises a main control and a permanent magnet synchronous generator control device of the second aspect, wherein the main control is electrically connected with a processor of the permanent magnet synchronous generator control device.

It should be noted that, the main controller according to the embodiment of the present application may include a main controller and an electronic device cooperating with the main controller, and the main controller is responsible for performing instructions (such as a start instruction, a given torque, and the like) and data (such as rotation speed information, and the like) with a processor of the control device of the permanent magnet synchronous generator.

According to a fourth aspect of embodiments herein, there is provided a computer readable storage medium having a program stored thereon, which when executed by a processor, implements the method of any one of the first aspects.

The computer readable storage medium may be an internal storage unit, such as a hard disk or a memory, of the wind turbine generator system according to any of the foregoing embodiments. The computer readable storage medium may also be an external storage device of the wind turbine, such as a plug-in hard disk, a Smart Media Card (SMC), an SD Card, a Flash memory Card (Flash Card), and the like, provided on the device. Further, the computer readable storage medium may also comprise both an internal storage unit of the wind park and an external storage device. The computer-readable storage medium is used for storing the computer program and other programs and data required by the wind park and may also be used for temporarily storing data that has been or will be output.

The above description is only exemplary of the present application and should not be taken as limiting the present application, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the scope of protection of the present application.