CN112583314B - Dynamic characteristic measuring method and system of doubly-fed generator excitation system - Google Patents

Abstract

The embodiment of the present invention provides a method and system for measuring the dynamic characteristics of an excitation system of a doubly-fed generator. The method includes: obtaining the stator voltage and stator current of the double-fed generator, and calculating the flux linkage angle of the double-fed generator; Position angle: Calculate the angle of the stator flux linkage of the doubly-fed generator relative to the rotor phase A axis according to the flux linkage angle and rotor position angle of the doubly-fed generator; according to the rotor voltage, rotor current and stator flux linkage of the doubly-fed generator With respect to the angle of the rotor A-phase axis, the excitation voltage and excitation current in the synchronous rotating coordinate system are obtained, and the dynamic characteristics analysis of the doubly-fed generator in the process of power disturbance is carried out. The application can visually judge the characteristics of the dynamic response of the excitation system of the doubly-fed generator in the field test, and provides an efficient technical means for the actual measurement modeling and field test.

Description

A dynamic characteristic measurement method and measurement system of a doubly-fed generator excitation system

Technical Field

The present invention relates to the field of generators, and in particular to a dynamic characteristic measurement method and a measurement system for an excitation system of a doubly-fed generator.

Background Art

With the development of high-power devices and modern control technology, the continuous variable speed operation technology of large-capacity energy storage units with two-level and three-level voltage source AC-DC-AC variable frequency excitation has developed rapidly and has been gradually put into commercial application. Since the frequency conversion equipment capacity of AC excitation variable speed motor is only about 1/5 of the main motor capacity and has a series of advantages, it has attracted more and more attention and has been gradually respected by the industry, especially in the application of wind farms and pumped storage power stations.

Traditional synchronous generators use centralized excitation windings, and their excitation current is DC, while the rotor excitation windings of doubly-fed generators are multi-phase AC windings, and the excitation voltage is a symmetrical AC with variable phase, amplitude, and frequency. The rotor uses two-level and three-level voltage source AC-DC-AC variable frequency excitation, so that the doubly-fed generator can achieve variable speed constant frequency operation. Compared with the excitation system of traditional generators, the AC excitation control of doubly-fed generators has a large degree of freedom, which can realize independent adjustment of active power and reactive power. It has fast power response speed and high unit operation efficiency, which surpass the performance of traditional synchronous generators. The on-site static, no-load and dynamic performance acceptance test of the doubly-fed generator excitation system is a key task to ensure the safe commissioning of related electrical equipment, and accurate and efficient measurement methods and measurement devices can improve the accuracy of on-site tests and provide a very intuitive perspective for the subsequent dynamic performance evaluation.

At present, what is measured in the grid-related performance detection of the excitation system of a doubly fed generator are mostly three-phase AC excitation voltage and excitation current signals. It is impossible to intuitively observe whether the active power and reactive power of the unit excitation system are completely decoupled under large and small disturbances, the changing characteristics of the active current and reactive current, and the control characteristics of the inner and outer loops of the generator AC excitation.

Summary of the invention

The embodiment of the present invention provides a dynamic characteristic measurement method, system and storage medium of a doubly-fed generator excitation system to solve the problem of inaccurate dynamic performance evaluation of a doubly-fed generator excitation system in the prior art.

根据检测到得光栅编码盘输出的圈脉冲和齿脉冲，计算得到双馈发电机的转子位置角

根据所述双馈发电机的磁链角

和转子位置角

计算双馈发电机的定子磁链相对于转子A相轴的角度δ；根据所述双馈发电机的转子电压U_ra、U_rb、U_rc，转子电流I_ra、I_rb、I_rc以及所述定子磁链相对于转子A相轴的角度δ，得到同步旋转坐标系下的励磁电压U_rd、U_rq和励磁电流I_rd、I_rq，依据所述励磁电压U_rd、U_rq和励磁电流I_rd、I_rq进行所述双馈发电机在功率扰动过程中的动态特性分析。In order to solve the above problems, the embodiment of the present invention discloses a method for measuring the dynamic characteristics of a doubly-fed generator excitation system, comprising: obtaining stator voltages U _SA , U _SB , U _SC and stator currents I _SA , I _SB , I _SC of the doubly-fed generator, and calculating the flux linkage angle of the doubly-fed generator according to the stator voltages and stator currents.

The rotor position angle of the doubly-fed generator is calculated based on the detected ring pulses and tooth pulses output by the grating encoder disk.

According to the flux angle of the doubly-fed generator

and rotor position angle

The angle δ of the stator flux of the doubly fed generator relative to the rotor A-phase axis is calculated; the excitation voltages _Urd , _Urq and the excitation currents _Ird , _Irq in a synchronous rotating coordinate system are obtained according to the rotor voltages Urd, _Urb , _Urc , the rotor currents _Ira , _Irb , _Irc and the angle δ of the stator flux relative to the rotor A-phase axis of the doubly fed generator; _and the dynamic characteristics of the doubly fed generator during power disturbance are analyzed according to the excitation voltages _Urd , _Urq and the excitation currents _Ird , _Irq .

转子位置角测量模块，用于根据检测到得光栅编码盘输出的圈脉冲和齿脉冲，计算得到双馈发电机的转子位置角

相对角度计算模块，用于根据所述双馈发电机的磁链角

和转子位置角

计算双馈发电机的定子磁链相对于转子A相轴的角度δ；励磁信号计算模块，用于根据所述双馈发电机的转子电压U_ra、U_rb、U_rc，转子电流I_ra、I_rb、I_rc以及所述定子磁链相对于转子A相轴的角度δ，得到同步旋转坐标系下的励磁电压U_rd、U_rq和励磁电流I_rd、I_rq，依据所述励磁电压U_rd、U_rq和励磁电流I_rd、I_rq进行所述双馈发电机在功率扰动过程中的动态特性分析。In order to solve the above problems, the embodiment of the present invention further discloses a dynamic characteristic measurement system of a doubly-fed generator excitation system, comprising: a flux linkage angle measurement module, which is used to obtain the stator voltages U _SA , U _SB , U _SC and the stator currents I _SA , I _SB , I _SC of the doubly-fed generator, and calculate the flux linkage angle of the doubly-fed generator according to the stator voltages and the stator currents.

The rotor position angle measurement module is used to calculate the rotor position angle of the doubly-fed generator based on the detected ring pulses and tooth pulses output by the grating encoder disk.

A relative angle calculation module is used to calculate the flux linkage angle of the double-fed generator according to the

and rotor position angle

Calculate the angle δ of the stator flux of the doubly fed generator relative to the rotor A-phase axis; an excitation signal calculation module, used to obtain the excitation voltage _Urd , Urq and the excitation current Ird, Irq in a synchronous rotating coordinate system according to the rotor voltage Ur, _Urb , _{Urc ,} the rotor current _Ira , _Irb , _Irc and the angle δ of the stator flux relative to the _rotor A-phase axis of the doubly fed generator, and perform dynamic characteristic analysis of the doubly fed generator during power disturbance based on _the excitation voltage _{Urd , Urq} and the excitation current _Ird , _Irq .

In order to solve the above problems, an embodiment of the present invention further discloses a non-volatile computer storage medium, which stores computer executable instructions. When the computer executable instructions are executed by a processor, the dynamic characteristics measurement method of the doubly fed generator excitation system described in any of the above embodiments is implemented.

The present application discloses a method, system and storage medium for measuring the dynamic characteristics of an excitation system of a doubly-fed generator, and proposes a method for measuring the excitation voltage and excitation current of a doubly-fed generator by converting the three-phase AC excitation voltage and excitation current of the doubly-fed generator into the excitation voltage and excitation current of the excitation system in a synchronous rotating coordinate system. This method can intuitively judge the dynamic response characteristics of the excitation system of the doubly-fed generator in field tests, and provides an efficient technical means for the actual measurement modeling and field testing of the excitation system of the doubly-fed generator.

With reference to the following description and accompanying drawings, specific embodiments of the present invention are disclosed in detail, indicating the manner in which the principles of the present invention can be adopted. It should be understood that the embodiments of the present invention are not limited in scope. Within the spirit and scope of the appended claims, the embodiments of the present invention include many changes, modifications and equivalents.

Features described and/or illustrated with respect to one embodiment may be used in the same or similar manner in one or more other embodiments, combined with features in other embodiments, or substituted for features in other embodiments.

It should be emphasized that the term “include/comprises” when used herein refers to the presence of features, integers, steps or components, but does not exclude the presence or addition of one or more other features, integers, steps or components.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative labor.

1 is a processing flow chart of a method for measuring dynamic characteristics of an excitation system of a doubly-fed generator according to an embodiment of the present invention;

FIG2 is a measurement result of physical quantities of a doubly-fed generator in a steady state in a specific embodiment of the present invention;

FIG3( a ) is a measurement result of a conventional excitation device corresponding to an active power step in a specific embodiment of the present invention;

FIG3( b ) is a measurement result of the excitation voltage and the excitation current in a synchronous rotating coordinate system obtained by using the dynamic characteristic measurement method proposed in the present invention when the active power step occurs in a specific embodiment of the present invention;

FIG4( a ) is a measurement result of a conventional excitation device corresponding to a reactive power step in a specific embodiment of the present invention;

FIG4( b ) is a diagram showing the measurement results of the excitation voltage and the excitation current in a synchronous rotating coordinate system obtained by using the dynamic characteristic measurement method proposed in the present invention when corresponding to a reactive power step in a specific embodiment of the present invention;

FIG5 is a processing flow chart of a dynamic characteristic measurement system of a doubly-fed generator excitation system according to an embodiment of the present invention.

DETAILED DESCRIPTION

The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

Those skilled in the art will appreciate that the embodiments of the present invention may be implemented as a system, device, apparatus, method or computer program product. Therefore, the present disclosure may be implemented in the following forms, namely: complete hardware, complete software (including firmware, resident software, microcode, etc.), or a combination of hardware and software.

The principle and spirit of the present invention are explained in detail below with reference to several representative embodiments of the present invention.

As mentioned in the prior art, the rotor excitation winding of the doubly-fed generator is a multi-phase AC winding, and the excitation voltage is a symmetrical AC with variable phase, amplitude and frequency. It is impossible to intuitively display the dynamic characteristics of the unit during power disturbance, the decoupling control characteristics of the power are unclear, and the relationship between the excitation current and the power is not intuitive. In view of this, the dynamic characteristics measurement method and measurement system of the doubly-fed generator excitation system disclosed in the present application propose a measurement method for converting the three-phase AC excitation voltage and excitation current of the doubly-fed generator into the excitation voltage and excitation current of the excitation system in a synchronous rotating coordinate system, so as to realize the intuitive evaluation of the dynamic response characteristics of the excitation system of the doubly-fed generator in the field test, and provide an efficient technical means for the actual measurement modeling and field testing of the doubly-fed generator excitation system.

FIG1 is a processing flow chart of a method for measuring dynamic characteristics of a doubly-fed generator excitation system according to an embodiment of the present invention. As shown in the figure, the method comprises:

Step S101, obtaining the stator voltages _USA , _USB , _USC and the stator currents _ISA , _ISB , _ISC of the doubly-fed generator, and calculating the flux linkage angle of the doubly-fed generator according to the stator voltages and stator currents.

Step S102, calculating the rotor position angle of the doubly-fed generator according to the detected ring pulse and tooth pulse output by the grating encoder disk

和转子位置角

计算双馈发电机的定子磁链相对于转子A相轴的角度δ；Step S103, according to the flux linkage angle of the doubly-fed generator

and rotor position angle

Calculate the angle δ of the stator flux of the doubly-fed generator relative to the rotor A-phase axis;

Step S104, obtaining the excitation voltages _Urd , Urq and the excitation currents Ird, Irq in a synchronous rotating coordinate system according to the rotor voltages _{Ur, Urb , Urc} , the rotor currents _Ira , _Irb , _Irc and the angle δ of the stator flux relative to the rotor _A - _{phase axis} of the doubly fed generator.

In some embodiments, the rotor inverter control of the doubly-fed generator adopts a specific vector control method to realize the decoupling control of the active power and reactive power of the unit. In the embodiment of the present invention, it is assumed that the rotor adopts a stator flux orientation method to realize the decoupling control of power. In step S101, the stator voltages U _SA , U _SB , U _SC and the stator currents I _SA , I _SB , I _SC of the doubly-fed generator can be directly collected by connecting the recorder to the device and then obtaining the recorder data. The flux angle of the doubly-fed generator can be calculated based on the stator voltage and stator current obtained by reading.

具体实现过程如下所示：In this embodiment, the flux differential can be obtained by first transforming the three-phase stator stationary coordinate system and the two-phase stator stationary coordinate system, and then the flux angle can be obtained through the PI link and the differential link.

The specific implementation process is as follows:

Among them, T _ABC/αβ represents the transformation of the voltage U _ABC and the current I _ABC in the three-phase stator stationary coordinate system to the two-phase stator stationary coordinate system; Pψ _αβ =U _αβ -RsI _αβ represents the differential term Pψ _αβ of the magnetic flux obtained by using the voltage U _αβ and the current I _αβ in the two-phase stator stationary coordinate system; K _P +K _i /s represents the proportional integral link; 1/s represents the differential factor.

In this step, in addition to obtaining physical quantities such as flux angle and stator voltage angle, the stator active power PS and reactive power QS of the doubly fed generator can also be calculated. The stator active power PS and reactive power QS can be used for unit operation characteristic analysis or transient characteristic analysis in machine-grid coordination.

In addition, in the embodiment of the present invention, the stator voltage orientation method can also be used to achieve power decoupling control, but in the excitation control design, the above-mentioned stator flux orientation method is mostly used.

同时还可以测得转子转速ω_r物理量。In some embodiments, in step S102, the rotor position angle can be measured by the ring pulse and tooth pulse signal output by the grating encoder disk installed on the rotor shaft of the doubly fed generator.

At the same time, the physical quantity of rotor speed ω _r can also be measured.

其中，N_set为测速码盘齿数设定值，N_count为实时读取的光栅编码盘输出的齿脉冲的计数值。In specific implementation, the rotor position angle

Wherein, N _set is the set value of the number of teeth of the speed measuring code disk, and N _count is the count value of the tooth pulse output by the grating encoder disk read in real time.

In this step, the rotor speed ωr obtained at the same time can be used for unit operation characteristic analysis or transient characteristic analysis in machine-grid coordination.

和转子位置角

计算双馈发电机的定子磁链相对于转子A相轴的角度δ，即

In some embodiments, in step S103, according to the flux linkage angle of the doubly-fed generator

and rotor position angle

Calculate the angle δ of the stator flux of the doubly fed generator relative to the rotor A phase axis, that is,

In some embodiments, in step S104, the excitation voltages _Urd , _Urq and the excitation currents _Ird , Irq in the synchronous rotating coordinate system are obtained using the following coordinate transformation algorithm formula according to the measurement signals and angle δ of the generator rotor voltages _{UrA , UrB , UrC} and the rotor currents _IrA , IrB, _IrC .

After the excitation voltages _Urd and _Urq and the excitation currents _Ird and _Irq in the synchronous rotating coordinate system are obtained, the dynamic characteristics of the double-fed generator during the power disturbance process are analyzed based on the excitation voltages _Urd and _Urq and the excitation currents _Ird and _Irq .

The present application discloses a method for measuring the dynamic characteristics of a doubly-fed generator excitation system, and proposes a method for measuring the excitation voltage and excitation current of a doubly-fed generator by converting the three-phase AC excitation voltage and excitation current of the doubly-fed generator into the excitation voltage and excitation current of the excitation system in a synchronous rotating coordinate system. This method can intuitively judge the dynamic response characteristics of the excitation system of the doubly-fed generator in field tests, and provides an efficient technical means for the actual measurement modeling and field testing of the excitation system of the doubly-fed generator.

The following is a specific embodiment of dynamic characteristic analysis using the dynamic characteristic measurement method of the doubly-fed generator excitation system according to an embodiment of the present invention. In this embodiment, a single-machine infinite system is considered to be built on a certain software platform, wherein the doubly-fed generator set adopts the parameters of a 300MW variable-speed pumped storage unit of a pumped storage power station, with a rated capacity of 336MVA, a rated power of 300MW, a stator voltage of 15.75kV, and a turns ratio of 2.439.

1. Measurement of excitation voltage and excitation current under steady state conditions

The rated load condition is considered here, that is, the active power Ps of the generator is 300MW, and the reactive power Qs is 145Mvar (Ps=0.9pu, Qs=0.436pu). As shown in Figure 2, the measurement results of the physical quantities of the doubly fed generator under steady-state conditions are as follows, from top to bottom: active power, reactive power, excitation voltage, excitation current, stator voltage, stator current, and machine-end voltage.

2. Dynamic characteristics measurement of excitation voltage and excitation current

The load conditions are investigated, active power and reactive power steps are generated respectively, and the generated power (active power, reactive power), excitation voltage and excitation current signals are measured.

FIG3(a) and FIG3(b) respectively correspond to the measurement results of the conventional excitation device and the measurement results of the excitation voltage and excitation current in the synchronous rotating coordinate system obtained by the dynamic characteristic measurement method proposed by the present invention when the active power step is 4%. Among them, FIG3(a) shows active power, reactive power, three-phase excitation voltage, and three-phase excitation current from top to bottom, and FIG3(b) shows d-axis component of excitation voltage, q-axis component of excitation voltage, d-axis component of excitation current, and q-axis component of excitation current from top to bottom.

FIG4(a) and FIG4(b) respectively correspond to the measurement results of the conventional excitation device and the measurement results of the excitation voltage and excitation current in the synchronous rotating coordinate system obtained by the dynamic characteristic measurement method proposed by the present invention when the reactive power step occurs. FIG4(a) shows, from top to bottom: active power, reactive power, three-phase excitation voltage, three-phase excitation current; FIG4(b) shows, from top to bottom: excitation voltage d-axis component, excitation voltage q-axis component, excitation current d-axis component, excitation current q-axis component.

It can be seen that the measurement results of the excitation voltage and excitation current in Figure 3(a) and Figure 4(a) are three-phase AC signals, which cannot intuitively display the dynamic characteristics of the unit during the power disturbance process, the power decoupling control characteristics are unclear, and the relationship between the excitation current and the power is not intuitive.

When an active power step occurs, as shown in FIG3(b), when the active power changes, the q-axis component of the excitation current is mainly affected, and the two are in a positive proportional relationship, while the d-axis component of the excitation current and the steady-state value of the reactive power are almost unaffected. When a reactive power step occurs, as shown in FIG4(b), when the reactive power changes, the d-axis component of the excitation current is mainly affected, and the two are in a positive proportional relationship, while the q-axis component of the excitation current and the steady-state value of the active power are almost unaffected. Therefore, by the dynamic characteristic measurement method of the doubly-fed generator excitation system of the present invention, the excitation voltage and excitation current of the doubly-fed motor excitation system in the synchronous rotating coordinate system are obtained, and the dynamic response characteristics of the excitation system of the doubly-fed generator on site can be intuitively judged. In addition, it is also proved that the unit excitation system realizes the decoupling control of active power and reactive power, thereby verifying the correctness and effectiveness of the method proposed in the present invention.

After introducing the method of the exemplary embodiment of the present invention, the dynamic characteristic measurement of the doubly fed generator excitation system of the exemplary embodiment of the present invention is introduced with reference to Figures 4(a) and 4(b). The implementation of the system can refer to the implementation of the above method, and the repeated parts will not be repeated. The terms "module" and "unit" used below can be software and/or hardware that implements the predetermined functions. Although the modules described in the following embodiments are preferably implemented in software, the implementation of hardware, or a combination of software and hardware, is also possible and conceivable.

转子位置角测量模块502，用于根据检测到得光栅编码盘输出的圈脉冲和齿脉冲，计算得到双馈发电机的转子位置角

相对角度计算模块503，用于根据所述双馈发电机的磁链角

和转子位置角

计算双馈发电机的定子磁链相对于转子A相轴的角度δ；励磁信号计算模块504，用于根据所述双馈发电机的转子电压U_ra、U_rb、U_rc，转子电流I_ra、I_rb、I_rc以及所述定子磁链相对于转子A相轴的角度δ，得到同步旋转坐标系下的励磁电压U_rd、U_rq和励磁电流I_rd、I_rq，依据所述励磁电压U_rd、U_rq和励磁电流I_rd、I_rq进行所述双馈发电机在功率扰动过程中的动态特性分析。FIG5 is a schematic diagram of the structure of the dynamic characteristic measurement system of the doubly-fed generator excitation system according to an embodiment of the present invention. As shown in the figure, it includes: a flux linkage angle measurement module 501, which is used to obtain the stator voltages U _SA , U _SB , U _SC and the stator currents I _SA , I _SB , I _SC of the doubly-fed generator, and calculate the flux linkage angle of the doubly-fed generator according to the stator voltages and stator currents.

The rotor position angle measurement module 502 is used to calculate the rotor position angle of the doubly-fed generator according to the detected ring pulses and tooth pulses output by the grating encoder disk.

The relative angle calculation module 503 is used to calculate the flux linkage angle of the double-fed generator according to the

and rotor position angle

Calculate the angle δ of the stator flux of the doubly fed generator relative to the rotor A-phase axis; an excitation signal calculation module 504, used to obtain the excitation voltages _Urd , Urq and the excitation currents Ird, Irq in a synchronous rotating coordinate system according to the rotor voltages _Ur , _Urb , _{Urc ,} the rotor currents _Ira , _Irb , _Irc and the angle δ of the stator flux relative to the rotor A-phase axis of the doubly fed generator, and perform dynamic characteristic analysis of the doubly fed generator during power disturbance based on the excitation _{voltages Urd , Urq} and the excitation currents _Ird , _Irq .

包括：所述磁链角测量模块根据所述定子电压和定子电流，通过三相定子静止坐标系与两相定子静止坐标系的变换获得磁链微分量，再经过PI环节与微分环节获得磁链角

In some embodiments, the flux angle measurement module 501 calculates the flux angle of the doubly-fed generator according to the stator voltage and the stator current.

The flux angle measurement module obtains the flux differential by transforming the three-phase stator stationary coordinate system and the two-phase stator stationary coordinate system according to the stator voltage and the stator current, and then obtains the flux angle through the PI link and the differential link.

包括：通过安装在发电机转子轴上的光栅编码盘输出的圈脉冲和齿脉冲信号，测得转子位置角

其中，N_set为测速码盘齿数设定值，N_count为实时读取的光栅编码盘输出的齿脉冲的计数值。In some embodiments, the rotor position angle measurement module 502 calculates the rotor position angle of the doubly-fed generator according to the detected ring pulses and tooth pulses output by the grating encoder disk.

Including: The rotor position angle is measured by the ring pulse and tooth pulse signal output by the grating encoder disk installed on the generator rotor shaft

Wherein, N _set is the set value of the number of teeth of the speed measuring code disk, and N _count is the count value of the tooth pulse output by the grating encoder disk read in real time.

和转子位置角

计算双馈发电机的定子磁链相对于转子A相轴的角度δ，包括：

In some embodiments, the relative angle calculation module 503 calculates the relative angle according to the flux linkage angle of the doubly-fed generator.

and rotor position angle

Calculate the angle δ of the stator flux of the doubly-fed generator relative to the rotor A-phase axis, including:

In some embodiments, the excitation signal calculation module 504 obtains the excitation voltage _Urd , Urq and the excitation current Ird, _Irq in the synchronous rotating coordinate system according to the rotor voltage _{Ur, Urb , Urc} , the rotor current _Ira , _Irb , _Irc and the angle δ of the stator _flux relative to the rotor A phase axis of the _{doubly fed} generator, including:

In addition, although several units of the dynamic characteristic measurement system of the doubly-fed generator excitation system are mentioned in the above detailed description, this division is not mandatory. In fact, according to an embodiment of the present invention, the features and functions of two or more units described above can be embodied in one unit. Similarly, the features and functions of one unit described above can also be further divided into multiple units to be embodied.

An embodiment of the present invention further provides a non-volatile computer storage medium storing computer executable instructions, which, when executed by a processor, implements the method for measuring the dynamic characteristics of a doubly-fed generator excitation system described in any of the above embodiments.

The present application discloses a method, system and storage medium for measuring the dynamic characteristics of an excitation system of a doubly-fed generator, and proposes a method for measuring the excitation voltage and excitation current of a doubly-fed generator by converting the three-phase AC excitation voltage and excitation current of the doubly-fed generator into the excitation voltage and excitation current of the excitation system in a synchronous rotating coordinate system. This method can intuitively judge the dynamic response characteristics of the excitation system of the doubly-fed generator in field tests, and provides an efficient technical means for the actual measurement modeling and field testing of the excitation system of the doubly-fed generator.

Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

The present invention is described with reference to the flowchart and/or block diagram of the method, device (system), and computer program product according to the embodiment of the present invention. It should be understood that each process and/or box in the flowchart and/or block diagram, as well as the combination of the process and/or box in the flowchart and/or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce a device for implementing the functions specified in one or more processes in the flowchart and/or one or more boxes in the block diagram.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory produce a manufactured product including an instruction device that implements the functions specified in one or more processes in the flowchart and/or one or more boxes in the block diagram.

These computer program instructions may also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, whereby the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more processes in the flowchart and/or one or more boxes in the block diagram.

The present invention uses specific embodiments to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims (3)

1. A method for measuring dynamic characteristics of a doubly-fed generator excitation system, comprising: Obtain the stator voltages U _SA , U _SB , U _SC and the stator currents I _SA , I _SB , I _SC of the doubly-fed generator, and calculate the flux linkage angle of the doubly-fed generator based on the stator voltages and stator currents.

The rotor position angle of the doubly-fed generator is calculated based on the detected ring pulses and tooth pulses output by the grating encoder disk.

According to the flux angle of the doubly-fed generator

and rotor position angle

Calculate the angle δ of the stator flux of the doubly-fed generator relative to the rotor A-phase axis; According to the rotor voltages _Ur , Ur _{, Ur} , and _Ur , the rotor currents I _ra , I _rb , and I _rc of the doubly-fed generator, and the angle δ of the stator flux relative to the rotor A-phase axis, the excitation voltages _Ur , _Urq and the excitation currents I _rd , I _rq in a synchronous rotating coordinate system are obtained, and the dynamic characteristics of the doubly-fed generator during the power disturbance process are analyzed according to the excitation voltages _Ur , _Urq and the excitation currents I _rd , I _rq ; Wherein, the flux linkage angle of the doubly fed generator is calculated based on the stator voltage and the stator current.

include: According to the stator voltage and stator current, the flux differential is obtained by transforming the three-phase stator stationary coordinate system and the two-phase stator stationary coordinate system, and then the flux angle is obtained through the PI link and the differential link.

The rotor position angle of the doubly-fed generator is calculated based on the detected ring pulse and tooth pulse output by the grating encoder disk.

include: The rotor position angle is measured by the ring pulses and tooth pulses output by the grating encoder disk installed on the generator rotor shaft.

Wherein, N _set is the set value of the number of teeth of the speed measuring code disk, and N _count is the count value of the tooth pulse output by the grating encoder disk read in real time; According to the stator voltage and stator current, the flux differential is obtained by transforming the three-phase stator stationary coordinate system and the two-phase stator stationary coordinate system, and then the flux angle is obtained through the PI link and the differential link.

The specific process includes:

Wherein, T _ABC/αβ represents the transformation of the stator voltage U _ABC and the stator current I _ABC in the three-phase stator stationary coordinate system to the two-phase stator stationary coordinate system; Pψ _αβ =U _αβ -RsI _αβ represents the magnetic flux differential Pψ _αβ obtained by using the stator voltage U _αβ and the stator current I _αβ in the two-phase stator stationary coordinate system; K _P +K _i /s represents the PI link; 1/s represents the differential factor; Wherein, the excitation voltages _Urd , Urq and the excitation currents Ird, Irq in a synchronous rotating coordinate system are obtained according to the rotor voltages _{Ur, Urb , Urc} , the rotor currents _Ira , _Irb , _Irc and the angle δ of the stator flux relative to the rotor _A - _{phase axis} of the doubly fed generator, including:

Wherein, the flux linkage angle of the doubly-fed generator

and rotor position angle

Calculate the angle δ of the stator flux of the doubly-fed generator relative to the rotor A-phase axis, including:

2. A dynamic characteristic measurement system of a doubly-fed generator excitation system, characterized by comprising: The flux linkage angle measurement module is used to obtain the stator voltages _USA , _USB , _USC and stator currents _ISA , _ISB , _ISC of the doubly-fed generator, and calculate the flux linkage angle of the doubly-fed generator based on the stator voltages and stator currents.

The rotor position angle measurement module is used to calculate the rotor position angle of the doubly-fed generator based on the detected ring pulses and tooth pulses output by the grating encoder disk.

A relative angle calculation module is used to calculate the flux linkage angle of the double-fed generator according to the

and rotor position angle

Calculate the angle δ of the stator flux of the doubly-fed generator relative to the rotor A-phase axis; an excitation signal calculation module, for obtaining excitation voltages _Urd , Urq and excitation currents Ird, Irq in a synchronous rotating coordinate system according to the rotor voltages _{Ur, Urb , Urc} , rotor currents _Ira , _Irb , _Irc of the doubly-fed generator and the angle δ of the stator flux relative to the rotor A-phase axis, and performing _dynamic characteristic analysis of the doubly-fed generator during power disturbance according to the excitation voltages _{Urd , Urq} and excitation currents _Ird , _{Irq ;} The flux angle measurement module calculates the flux angle of the doubly-fed generator according to the stator voltage and the stator current.

include: The flux angle measurement module obtains the flux differential according to the stator voltage and stator current by transforming the three-phase stator stationary coordinate system and the two-phase stator stationary coordinate system, and then obtains the flux angle through the PI link and the differential link.

The rotor position angle measurement module calculates the rotor position angle of the doubly-fed generator based on the detected ring pulses and tooth pulses output by the grating encoder disk.

include: The rotor position angle is measured by the ring pulse and tooth pulse signals output by the grating encoder disk installed on the generator rotor shaft.

Wherein, N _set is the set value of the number of teeth of the speed measuring code disk, and N _count is the count value of the tooth pulse output by the grating encoder disk read in real time; According to the stator voltage and stator current, the flux differential is obtained by transforming the three-phase stator stationary coordinate system and the two-phase stator stationary coordinate system, and then the flux angle is obtained through the PI link and the differential link.

The specific process includes:

Wherein, T _ABC/αβ represents the transformation of the stator voltage U _ABC and the stator current I _ABC in the three-phase stator stationary coordinate system to the two-phase stator stationary coordinate system; Pψ _αβ =U _αβ -RsI _αβ represents the magnetic flux differential Pψ _αβ obtained by using the stator voltage U _αβ and the stator current I _αβ in the two-phase stator stationary coordinate system; K _P +K _i /s represents the PI link; 1/s represents the differential factor; Wherein, the excitation voltages _Urd , Urq and the excitation currents Ird, Irq in a synchronous rotating coordinate system are obtained according to the rotor voltages _{Ur, Urb , Urc} , the rotor currents _Ira , _Irb , _Irc and the angle δ of the stator flux relative to the rotor _A - _{phase axis} of the doubly fed generator, including:

The relative angle calculation module is based on the flux linkage angle of the doubly fed generator.

and rotor position angle

Calculate the angle δ of the stator flux of the doubly-fed generator relative to the rotor A-phase axis, including:

3. A non-volatile computer storage medium storing computer executable instructions, wherein the computer executable instructions, when executed by a processor, implement the dynamic characteristics measurement method of a doubly-fed generator excitation system according to any one of claim 1.

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