CN116826786A - New energy power system weak point positioning method and system - Google Patents
New energy power system weak point positioning method and system Download PDFInfo
- Publication number
- CN116826786A CN116826786A CN202310715203.8A CN202310715203A CN116826786A CN 116826786 A CN116826786 A CN 116826786A CN 202310715203 A CN202310715203 A CN 202310715203A CN 116826786 A CN116826786 A CN 116826786A
- Authority
- CN
- China
- Prior art keywords
- impedance
- new energy
- broadband
- phase margin
- station
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000000034 method Methods 0.000 title claims abstract description 55
- 230000010355 oscillation Effects 0.000 claims abstract description 56
- 238000011156 evaluation Methods 0.000 claims abstract description 17
- 238000012163 sequencing technique Methods 0.000 claims abstract description 9
- 238000005096 rolling process Methods 0.000 claims abstract description 7
- 230000015654 memory Effects 0.000 claims description 23
- 238000004590 computer program Methods 0.000 claims description 17
- 238000003860 storage Methods 0.000 claims description 13
- 230000001360 synchronised effect Effects 0.000 claims description 6
- 230000005540 biological transmission Effects 0.000 claims description 4
- 238000004364 calculation method Methods 0.000 claims description 3
- 238000013499 data model Methods 0.000 claims description 3
- 238000004146 energy storage Methods 0.000 claims description 3
- 230000004927 fusion Effects 0.000 claims description 3
- 238000005259 measurement Methods 0.000 claims description 3
- 238000010586 diagram Methods 0.000 description 10
- 230000006870 function Effects 0.000 description 4
- 238000012545 processing Methods 0.000 description 4
- 238000012986 modification Methods 0.000 description 3
- 230000004048 modification Effects 0.000 description 3
- 238000004891 communication Methods 0.000 description 2
- 230000004807 localization Effects 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- 230000004075 alteration Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 238000013016 damping Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 238000010248 power generation Methods 0.000 description 1
- 230000003449 preventive effect Effects 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 238000012502 risk assessment Methods 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
Landscapes
- Supply And Distribution Of Alternating Current (AREA)
Abstract
The application provides a method and a system for locating weak points of a new energy power system, comprising the following steps: the method comprises the steps of adopting a new energy station impedance identification method driven by data and knowledge in a combined mode to acquire broadband impedance of a new energy station at a grid-connected point and broadband impedance of an alternating current power grid on line; adopting an impedance stability criterion to evaluate the stability of the system on line, and acquiring the phase margin and the potential oscillation frequency of the system; if the system phase margin is lower than the threshold value, calculating the real part of impedance of each new energy station at the potential oscillation frequency according to the broadband impedance identified on line; sequencing according to the magnitude of the real part of the impedance, wherein one or more new energy stations with the smallest real part of the impedance are weak points of the system; if the system phase margin is greater than the threshold, the rolling on-line assessment of the weak points of the system is repeated at intervals. The application carries out real-time online evaluation on the stable state of the new energy power system; the weak point of the system is located before oscillation occurs to further eliminate the oscillation hidden trouble.
Description
Technical Field
The application relates to the technical field of new energy power generation, in particular to a method and a system for locating weak points of a new energy power system.
Background
Under the severe situations of energy and environmental crisis, the construction of a novel power system mainly based on new energy has become an industry consensus. However, with the massive access of high-proportion new energy and high-proportion power electronic equipment, the problem of broadband oscillation of the novel power system is different from that of the traditional power system, and the novel power system provides challenges for the stable control of the power grid.
In order to reduce the impact of broadband oscillation on a new energy power system, research on an online risk assessment method of broadband oscillation is urgently needed, and online assessment of the system steady state and positioning of system oscillation weak points are necessary, and preventive measures are adopted in advance before oscillation occurs to improve the system stability and reduce the system oscillation risk. The existing research mainly aims at an oscillation tracing method adopted after the traditional power system or the new energy power system generates low-frequency or subsynchronous/supersynchronous oscillation, but the stability of the system before oscillation occurs is evaluated on line and weak points are positioned in a few documents, and particularly, effective means are not available in the aspect of positioning broadband oscillation weak points of the power system mainly based on new energy.
Therefore, the application provides a method and a system for locating weak points of a new energy power system.
Disclosure of Invention
Aiming at the defects in the prior art, the application provides a method and a system for locating weak points of a new energy power system.
According to a first aspect of the present application, there is provided a new energy power system weak point positioning method, comprising:
the method comprises the steps of adopting a new energy station impedance identification method driven by data and knowledge in a combined mode to acquire broadband impedance of a new energy station at a grid-connected point and broadband impedance of an alternating current power grid on line;
based on the broadband impedance, adopting an impedance stability criterion to evaluate the stability of the system on line, and acquiring the phase margin and the potential oscillation frequency of the system;
if the system phase margin is lower than a set threshold value, calculating an impedance real part of each new energy station at a potential oscillation frequency according to the broadband impedance identified on line; sequencing according to the magnitude of the real part of the impedance, wherein one or more new energy stations with the smallest real part of the impedance are weak points of the system;
and if the system phase margin is larger than the set threshold value, repeatedly performing rolling online evaluation on the weak points of the system according to the set interval time.
Preferably, the new energy power system includes: the system comprises a permanent magnet direct drive wind power plant, a doubly-fed wind power plant, a photovoltaic power station, a synchronous generator, a transmission line and an energy storage power station.
Preferably, the method for identifying impedance of a new energy station driven by combination of data and knowledge obtains broadband impedance of the new energy station at a grid-connected point and broadband impedance of an ac power grid on line, including:
aiming at a new energy unit with random uncertainty input, a data driving method is adopted to establish a broadband impedance online identification model covering the whole steady-state operation condition; combining a physical structure model of the new energy station to construct a data-model fusion-driven new energy station broadband impedance online identification model; according to the network topology among the new energy stations, obtaining a broadband impedance online identification model of the new energy cluster through impedance network calculation;
based on the broadband impedance online identification model of the new energy cluster, obtaining broadband impedance Z of each new energy station according to the running state of each new energy unit and the voltage and current measurement data REx Broadband impedance Z of new energy cluster RE And obtains the broadband impedance Z of the alternating current power grid on line g 。
Preferably, the step of evaluating the stability of the system on line based on the broadband impedance by adopting an impedance stability criterion to obtain a system phase margin and a potential oscillation frequency includes:
according to the broadband impedance Z of the online acquired new energy cluster at the grid-connected point RE Said broadband impedance Z of the AC network g Defining a system phase margin as:
wherein: the symbol I indicates amplitude, the angle indicates phase, PM indicates phase margin, ω c Representing impedance Z g And Z RE Frequency corresponding to the intersection point of the amplitude-frequency curve;
setting the threshold value of the system phase margin PM to be theta th ；
If the system phase margin PM is greater than a set threshold value θ th If the system stability margin is larger, the system is in a stable state;
if the system phase margin PM is less than a set threshold value θ th The system stability margin is smaller, and the instability risk exists, namely the intersection point frequency omega c Is the potential oscillation frequency.
Preferably, if the system phase margin is lower than a set threshold value theta th Calculating potential oscillation frequency omega of each new energy station c The real part of the impedance is ranked according to the magnitude of the real part of the impedance, and one or more new energy stations with the smallest real part of the impedance are weak points of the system, and the method comprises the following steps:
respectively obtaining the new energy stations (omega) 1 To omega n ) Broadband impedance Z at port(s) REx (jω 1 )、Z REx (jω 2 )、…、Z REx (jω c )、…、Z REx (jω n ) (x=1, 2, … n, x stands for different new energy stations),
acquiring impedance Z at each new energy station port according to the potential oscillation frequency RE1 (jω c )、Z RE2 (jω c )、…Z REn (jω c ) Respectively extracting the real part R of the impedance at each new energy station port RE1 (jω c )、R RE2 (jω c )、…R REn (jω c )；
Sequencing according to the magnitude of the real parts of the impedance to obtain the smallest real part or parts of the impedance, wherein the corresponding new energy station is defined as a weak point of the system.
Preferably, the set interval time is 15 minutes.
Preferably, the threshold range of the system phase margin PM is 15 to 45 degrees.
According to a second aspect of the present application, there is provided a weak point positioning system of a new energy power system, comprising:
the new energy station impedance identification module adopts a new energy station impedance identification method driven by data and knowledge in a combined mode, and obtains broadband impedance of the new energy station at a grid connection point and broadband impedance of an alternating current power grid on line;
the stability margin evaluation module is used for evaluating the stability of the system on line by utilizing an impedance stability criterion based on the broadband impedance, and acquiring the phase margin and the potential oscillation frequency of the system;
the weak point positioning module calculates the real part of impedance of each new energy station at the potential oscillation frequency according to the broadband impedance identified on line under the condition that the system phase margin is lower than a set threshold value; sequencing according to the magnitude of the real part of the impedance, wherein one or more new energy stations with the smallest real part of the impedance are weak points of the system;
and the timing module repeatedly starts the new energy station impedance identification module, the stability margin evaluation module and the weak point positioning module at intervals when the system phase margin is larger than a set threshold value, and performs rolling online evaluation on the weak point of the system.
According to a third aspect of the present application, there is provided a terminal comprising a memory, a processor and a computer program stored on the memory and executable on the processor, the processor being operable to perform the method of locating points of weakness of the new energy power system or to run the system of locating points of weakness of the new energy power system when executing the program.
According to a fourth aspect of the present application, there is provided a computer readable storage medium having stored thereon a computer program which when executed by a processor is operable to perform the new energy power system vulnerability localization method or to run the new energy power system vulnerability localization system.
By adopting the technical scheme, compared with the prior art, the embodiment of the application has at least one of the following beneficial effects:
the method and the system for locating the weak points of the new energy power system can be used for carrying out real-time online evaluation on the stable state of the new energy power system;
according to the method and the system for locating the weak points of the new energy power system, provided by the embodiment of the application, the weak points of the system are located before oscillation occurs, so that the hidden danger of oscillation is further eliminated. The method is suitable for a complex new energy power system and has the advantages of strong operability, high accuracy and the like.
Drawings
Other features, objects and advantages of the present application will become more apparent upon reading of the detailed description of non-limiting embodiments, given with reference to the accompanying drawings in which:
FIG. 1 is a flow chart of a method for locating weak points of a new energy station according to an embodiment of the present application;
FIG. 2 is a schematic diagram of a weak point positioning system of a new energy station according to an embodiment of the present application.
FIG. 3 is a schematic diagram of a new energy station according to a preferred embodiment of the present application;
FIG. 4 is a schematic diagram illustrating a new energy power system simplified into three small new energy stations according to a preferred embodiment of the present application;
FIG. 5 is a bird diagram of the grid tie-in impedance and the AC grid impedance of the new energy station in a preferred embodiment of the present application; (a) a graph reflecting impedance magnitude versus frequency; the graph (b) reflects the impedance phase and frequency relationship.
Detailed Description
The present application will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the present application, but are not intended to limit the application in any way. It should be noted that variations and modifications could be made by those skilled in the art without departing from the inventive concept. These are all within the scope of the present application.
As shown in fig. 1, the application provides an embodiment, a new energy station weak point positioning method based on port time domain response, which specifically comprises the following steps:
s100, acquiring broadband impedance of the new energy station at a grid-connected point and broadband impedance of an alternating current power grid on line by adopting a new energy station impedance identification method driven by data and knowledge;
s200, broadband impedance is obtained based on the S100, the stability of the system is evaluated on line by utilizing an impedance stability criterion, and the phase margin and the potential oscillation frequency of the system are obtained;
s300, if the system phase margin in S200 is lower than a set threshold, calculating the real part of impedance of each new energy station at the potential oscillation frequency according to the broadband impedance identified on line; sequencing according to the magnitude of the real part of the impedance, wherein one or more new energy stations with the smallest real part of the impedance are weak points of the system;
s400, if the system phase margin in S200 is larger than the set threshold, repeating S100-S300 according to the set interval time, and performing rolling online evaluation on the weak points of the system.
The embodiment can carry out real-time online evaluation on the stable state of the new energy power system; in the embodiment, the weak point of the system is positioned before oscillation occurs, so that the hidden danger of the oscillation is eliminated.
In a preferred embodiment of the application, the new energy station comprises a full-power permanent magnet direct-drive wind turbine, a double-fed wind turbine, a photovoltaic generator, a synchronous machine, a transmission line, an energy storage unit and the like.
In a preferred embodiment of the present application, S100 is implemented, and a method for identifying impedance of a new energy station driven by combination of data and knowledge is adopted to obtain broadband impedance of the new energy station at a grid-connected point and broadband impedance of an ac power grid on line, and specifically includes the following steps:
s101, aiming at a new energy unit with random uncertainty input, a data driving method is adopted to establish a broadband impedance online identification model covering the whole steady-state operation condition;
s102, constructing a data-model fusion-driven new energy station broadband impedance online identification model by combining a physical structure model of the new energy station;
s103, further obtaining a broadband impedance online identification model of the new energy cluster through impedance network calculation according to the network topology among the new energy stations;
s104, obtaining the broadband impedance Z of each new energy station according to the operation state of each new energy unit and the voltage and current measurement data based on the broadband impedance online identification model of the new energy station in S103 REx And broadband impedance ZRE of the new energy cluster, and acquiring broadband impedance Z of the alternating current power grid on line g 。
Further, for a detailed implementation of S100, see patent application No. 202210991337.8.
In a preferred embodiment of the present application, implementation S200, evaluating the stability of the system based on the impedance stability criterion, obtaining the phase margin and the potential oscillation frequency of the system, specifically includes the following steps:
s201, broadband impedance Z of the new energy cluster at the grid-connected point is obtained on line RE Broadband impedance Z of AC network g The system phase margin is defined as follows:
wherein: the symbol I indicates amplitude, the angle indicates phase, PM indicates phase margin, ω c Representing impedance Z g And Z RE Frequency corresponding to the intersection point of amplitude-frequency curves.
S202, setting the threshold value of the system phase margin PM as theta th The threshold value for PM is typically selected to be 15 to 45 degrees.
If the system phase margin PM is greater than a set threshold value θ th If the system stability margin is larger, the system is in a stable state;
if the system phase margin PM is less than a set threshold value θ th The system stability margin is lower, the memoryAt risk of instability, the intersection frequency ω c Is the potential oscillation frequency.
In this embodiment, step S200 evaluates the stability of the system based on the impedance stability criterion, acquires the phase margin and the potential oscillation frequency of the system, and after determining the potential oscillation frequency, performs step S300 to locate the weak station under the potential oscillation frequency.
In a preferred embodiment of the present application, S300 is implemented if the system phase margin is below the set threshold θ th Calculating potential oscillation frequency omega of each new energy station c The real part of the impedance is sequenced according to the magnitude of the real part of the impedance, and one or more new energy stations with the minimum real part of the impedance are weak points of the system, and the method specifically comprises the following steps:
according to the potential oscillation frequency, obtaining the impedance Z at each new energy station port RE1 (jω c )、Z RE2 (jω c )、…Z REn (jω c ) Respectively extracting real parts R of impedance at ports of each new energy station RE1 (jω c )、R RE2 (jω c )、…R REn (jω c ) The real parts of the impedance are ordered according to the magnitude of the real parts of the impedance, the smallest real part or parts of the impedance are obtained, the corresponding new energy station is defined as the weak point of the system (the real part of the impedance represents the resistance, and at the potential oscillation frequency, the station with small resistance considers that the damping of the oscillation is smaller, and therefore the station is regarded as the weak point).
The embodiment locates weak points of the system before oscillation occurs to further eliminate the oscillation hidden trouble. The method is suitable for a complex new energy power system and has the advantages of strong operability, high accuracy and the like.
In a preferred embodiment of the application, S400 is implemented, wherein if the system phase margin is greater than the set threshold, the above steps are continued for 15 minutes intervals, and the system weak points are evaluated online by scrolling.
The embodiment sets the weak point of the timing on-line evaluation system, can ensure that the weak point of the system is found in time, and avoids oscillation.
Referring to fig. 2, based on the same inventive concept, in other embodiments of the present application, there is provided a weak point positioning system of a new energy station, comprising:
the new energy station impedance identification module adopts a new energy station impedance identification method driven by data and knowledge in a combined mode, and obtains broadband impedance of the new energy station at a grid connection point and broadband impedance of an alternating current power grid on line;
the stability margin evaluation module is used for evaluating the stability of the system on line by utilizing impedance stability criteria and acquiring the phase margin and the potential oscillation frequency of the system;
the weak point positioning module calculates the real part of impedance of each new energy station at the potential oscillation frequency according to the broadband impedance identified on line under the condition that the system phase margin is lower than a set threshold value; sequencing according to the magnitude of the real part of the impedance, wherein one or more new energy stations with the smallest real part of the impedance are weak points of the system;
and the timing module repeatedly starts the new energy station impedance identification module, the stability margin evaluation module and the weak point positioning module at intervals when the system phase margin is larger than a set threshold value, and performs rolling online evaluation on the weak point of the system.
The specific implementation techniques of the steps corresponding to the weak point positioning method of the new energy station in the foregoing embodiments may be referred to for each module/unit in the foregoing embodiments of the present application, and will not be described herein again.
Based on the same inventive concept, in other embodiments of the present application, a terminal is provided, including a memory, a processor, and a computer program stored on the memory and executable on the processor, the processor being operable to perform the above-described method or to run the above-described system when executing the program.
Optionally, a memory for storing a program; memory, which may include volatile memory (english) such as random-access memory (RAM), such as static random-access memory (SRAM), double data rate synchronous dynamic random-access memory (Double Data Rate Synchronous Dynamic Random Access Memory, DDR SDRAM), and the like; the memory may also include a non-volatile memory (English) such as a flash memory (English). The memory is used to store computer programs (e.g., application programs, functional modules, etc. that implement the methods described above), computer instructions, etc., which may be stored in one or more memories in a partitioned manner. And the above-described computer programs, computer instructions, data, etc. may be invoked by a processor.
A processor for executing the computer program stored in the memory to implement the steps in the method according to the above embodiment. Reference may be made in particular to the description of the embodiments of the method described above.
The processor and the memory may be separate structures or may be integrated structures that are integrated together. When the processor and the memory are separate structures, the memory and the processor may be connected by a bus coupling.
Based on the same inventive concept, in other embodiments of the present application, a computer-readable storage medium is provided, on which a computer program is stored, which program, when being executed by a processor, is operative to perform the method described above, or to run the system described above.
Among them, computer-readable media include computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media may be any available media that can be accessed by a general purpose or special purpose computer. An exemplary storage medium is coupled to the processor such the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. The processor and the storage medium may reside in an ASIC. In addition, the ASIC may reside in a user device. The processor and the storage medium may reside as discrete components in a communication device.
It will be appreciated by those skilled in the art that embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.
The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to the application. It will be understood that each flow and/or block of the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
It will be apparent to those skilled in the art that various modifications and variations can be made to the present application without departing from the spirit or scope of the application. Thus, it is intended that the present application also include such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.
The technical solutions provided in the above embodiments of the present application are described in further detail below in conjunction with a specific application example.
In the specific application example, the voltage of an alternating current power grid is 220kV/50Hz, the voltage of a port of a new energy station is 230kV/50Hz, the new energy stations are connected through a 230kV alternating current line, and the internal reactance of the alternating current power grid is formed by a pure inductance L g The composition is formed.
As shown in fig. 3, in this specific application example, the new energy power system includes a wind farm, a photovoltaic power station, a transmission line, a synchronous machine, a load, and the like.
As shown in fig. 4, in this specific application example, the new energy power system is simplified into three small new energy stations, in which the new energy station 3 has twice as many new energy stations 1 and 2.
As shown in fig. 5, the graph (a) in fig. 5 reflects the relationship between the impedance amplitude and the frequency, and the graph (b) in fig. 5 reflects the relationship between the impedance phase and the frequency. And identifying the impedance of the new energy station cluster at the grid connection point and the real-time impedance of the alternating current power grid, so that an impedance amplitude and phase curve of the new energy station at the grid connection point, shown by a black solid line, is obtained, and the black dotted line is the impedance amplitude and phase curve of the alternating current power grid.
Broadband impedance Z at grid-connected point according to online acquired new energy cluster RE Broadband impedance Z of AC network g The system phase margin is defined as follows:
wherein: the symbol I indicates amplitude, the angle indicates phase, PM indicates phase margin, ω c Representing impedance Z g And Z RE Frequency corresponding to the intersection point of amplitude-frequency curves.
If the system phase marginPM is less than a set threshold value θ th Then the intersection point frequency omega c Is the potential oscillation frequency.
The phase threshold is set to 15 degrees, the frequency of the system at the intersection point is 293Hz, the phase margin is 9.5 degrees, and is lower than the set phase threshold, thus defining 293Hz as the potential oscillation frequency of the system. Then, the real part of the port impedance of each new energy station at the potential oscillation frequency is calculated, R 1 ＝R 2 ＝1.22Ω，R 3 =0.60 Ω, it can be seen that the real part of impedance of the new energy station 3 is the smallest, and thus the new energy station 3 is a weak station of the system.
The broadband impedance based on online identification can realize online evaluation of broadband oscillation stability of the new energy power system, and accurately position weak points of the system before oscillation occurs, thereby laying a foundation for further eliminating hidden danger of oscillation.
Claims (10)
1. The utility model provides a new forms of energy electric power system weak point location method which characterized in that includes:
the method comprises the steps of adopting a new energy station impedance identification method driven by data and knowledge in a combined mode to acquire broadband impedance of a new energy station at a grid-connected point and broadband impedance of an alternating current power grid on line;
based on the broadband impedance, adopting an impedance stability criterion to evaluate the stability of the system on line, and acquiring the phase margin and the potential oscillation frequency of the system;
if the system phase margin is lower than a set threshold value, calculating an impedance real part of each new energy station at a potential oscillation frequency according to the broadband impedance identified on line; sequencing according to the magnitude of the real part of the impedance, wherein one or more new energy stations with the smallest real part of the impedance are weak points of the system;
and if the system phase margin is larger than the set threshold value, repeatedly performing rolling online evaluation on the weak points of the system according to the set interval time.
2. The method for locating weak points of a new energy power system according to claim 1, wherein the new energy power system comprises: the system comprises a permanent magnet direct drive wind power plant, a doubly-fed wind power plant, a photovoltaic power station, a synchronous generator, a transmission line and an energy storage power station.
3. The method for locating weak points of a new energy power system according to claim 1, wherein the method for identifying impedance of a new energy station driven by combination of data and knowledge is characterized by obtaining broadband impedance of the new energy station at a grid-connected point and broadband impedance of an ac power grid on line, and comprises the following steps:
aiming at a new energy unit with random uncertainty input, a data driving method is adopted to establish a broadband impedance online identification model covering the whole steady-state operation condition; combining a physical structure model of the new energy station to construct a data-model fusion-driven new energy station broadband impedance online identification model; according to the network topology among the new energy stations, obtaining a broadband impedance online identification model of the new energy cluster through impedance network calculation;
based on the broadband impedance online identification model of the new energy cluster, obtaining broadband impedance Z of each new energy station according to the running state of each new energy unit and the voltage and current measurement data REx Broadband impedance Z of new energy cluster RE And obtains the broadband impedance Z of the alternating current power grid on line g 。
4. The method for locating weak points of a new energy power system according to claim 3, wherein the step of evaluating the stability of the system on line based on the broadband impedance and using an impedance stability criterion to obtain a system phase margin and a potential oscillation frequency comprises the steps of:
according to the broadband impedance Z of the online acquired new energy cluster at the grid-connected point RE Said broadband impedance Z of the AC network g Defining a system phase margin as:
wherein: symbolThe number indicates amplitude, the angle indicates phase, PM indicates phase margin, ω c Representing impedance Z g And Z RE Frequency corresponding to the intersection point of the amplitude-frequency curve;
setting the threshold value of the system phase margin PM to be theta th 。
If the system phase margin PM is greater than a set threshold value θ th If the system stability margin is larger, the system is in a stable state;
if the system phase margin PM is less than a set threshold value θ th The system stability margin is smaller, and the instability risk exists, namely the intersection point frequency omega c Is the potential oscillation frequency.
5. The method for locating weak points of a new energy power system according to claim 4, wherein if the system phase margin is lower than a set threshold value θ th Calculating potential oscillation frequency omega of each new energy station c The real part of the impedance is ranked according to the magnitude of the real part of the impedance, and one or more new energy stations with the smallest real part of the impedance are weak points of the system, and the method comprises the following steps:
respectively obtaining different frequencies omega of each new energy station 1 To omega n Broadband impedance Z at lower port REx (jω 1 )、Z REx (jω 2 )、…、Z REx (jω c )、…、Z REx (jω n ) (x=1, 2, … n, x stands for different new energy stations), according to said potential oscillation frequency ω c Obtaining the impedance Z at each new energy station port RE1 (jω c )、Z RE2 (jω c )、…Z REn (jω c ) Respectively extracting the real part R of the impedance at each new energy station port RE1 (jω c )、R RE2 (jω c )、…R REn (jω c )；
Sequencing according to the magnitude of the real parts of the impedance to obtain the smallest real part or parts of the impedance, wherein the corresponding new energy station is defined as a weak point of the system.
6. The method for locating weak points of a new energy power system according to claim 1, wherein the time interval is 15 minutes.
7. The method for locating weak points of a new energy power system according to claim 4, wherein the threshold range of the system phase margin PM is 15-45 degrees.
8. A weak point positioning system of a new energy power system is characterized by comprising:
the new energy station impedance identification module adopts a new energy station impedance identification method driven by data and knowledge in a combined mode, and obtains broadband impedance of the new energy station at a grid connection point and broadband impedance of an alternating current power grid on line;
the stability margin evaluation module is used for evaluating the stability of the system on line by utilizing an impedance stability criterion based on the broadband impedance, and acquiring the phase margin and the potential oscillation frequency of the system;
the weak point positioning module calculates the real part of impedance of each new energy station at the potential oscillation frequency according to the broadband impedance identified on line under the condition that the system phase margin is lower than a set threshold value; sequencing according to the magnitude of the real part of the impedance, wherein one or more new energy stations with the smallest real part of the impedance are weak points of the system;
and the timing module repeatedly starts the new energy station impedance identification module, the stability margin evaluation module and the weak point positioning module at intervals when the system phase margin is larger than a set threshold value, and performs rolling online evaluation on the weak point of the system.
9. A terminal comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the processor is operable to perform the method of any one of claims 1-7 or to run the system of claim 8 when the program is executed by the processor.
10. A computer readable storage medium having stored thereon a computer program, which when executed by a processor is operative to perform the method of any one of claims 1-7 or to run the system of claim 8.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310715203.8A CN116826786B (en) | 2023-06-15 | 2023-06-15 | New energy power system weak point positioning method and system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310715203.8A CN116826786B (en) | 2023-06-15 | 2023-06-15 | New energy power system weak point positioning method and system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN116826786A true CN116826786A (en) | 2023-09-29 |
| CN116826786B CN116826786B (en) | 2024-05-31 |
Family
ID=88123448
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310715203.8A Active CN116826786B (en) | 2023-06-15 | 2023-06-15 | New energy power system weak point positioning method and system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116826786B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN118259066A (en) * | 2024-05-29 | 2024-06-28 | 国网安徽省电力有限公司经济技术研究院 | Voltage stability assessment method based on time domain response track |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110176762A (en) * | 2019-05-16 | 2019-08-27 | 国电南瑞科技股份有限公司 | A kind of sub-synchronous oscillation risk online evaluation method and device based on frequency domain impedance |
| CN112381671A (en) * | 2020-11-30 | 2021-02-19 | 华北电力科学研究院有限责任公司 | Broadband oscillation risk assessment method for new energy station grid-connected power system |
| CN115249980A (en) * | 2022-08-18 | 2022-10-28 | 上海交通大学 | New energy station impedance identification method and system driven by data and knowledge in combined mode |
-
2023
- 2023-06-15 CN CN202310715203.8A patent/CN116826786B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110176762A (en) * | 2019-05-16 | 2019-08-27 | 国电南瑞科技股份有限公司 | A kind of sub-synchronous oscillation risk online evaluation method and device based on frequency domain impedance |
| CN112381671A (en) * | 2020-11-30 | 2021-02-19 | 华北电力科学研究院有限责任公司 | Broadband oscillation risk assessment method for new energy station grid-connected power system |
| CN115249980A (en) * | 2022-08-18 | 2022-10-28 | 上海交通大学 | New energy station impedance identification method and system driven by data and knowledge in combined mode |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN118259066A (en) * | 2024-05-29 | 2024-06-28 | 国网安徽省电力有限公司经济技术研究院 | Voltage stability assessment method based on time domain response track |
Also Published As
| Publication number | Publication date |
|---|---|
| CN116826786B (en) | 2024-05-31 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109713685B (en) | Online positioning method suitable for VSC access-induced subsynchronous oscillation | |
| CN108667005B (en) | Power grid static and dynamic combination vulnerability assessment method considering new energy influence | |
| CN116826786B (en) | New energy power system weak point positioning method and system | |
| CN112736988B (en) | New energy power system inertia estimation method considering influence of primary frequency modulation and droop control | |
| CN109301814B (en) | Method and system for analyzing wind power capacity of access power grid | |
| CN115249980A (en) | New energy station impedance identification method and system driven by data and knowledge in combined mode | |
| CN107947199B (en) | Optimization model-based method for searching thermal stability security domain boundary of electric power system | |
| CN110867889B (en) | Oscillation stability judging method and system for wind power plant/unit connected with alternating current power grid | |
| CN102684586A (en) | Leading generator parameter aggregation method for dynamic equivalence of alternating current and direct current large power grid | |
| CN114759594B (en) | Direct-drive wind farm stability assessment method and system considering interaction between machines | |
| CN112072692B (en) | Impedance equivalence method and device for new energy power generation station | |
| CN105762816A (en) | Method for inhibiting subsynchronous interaction | |
| Rao et al. | Wideband impedance online identification of wind farms based on combined data-driven and knowledge-driven | |
| CN104268316B (en) | Off-line calculation and online matching based doubly-fed wind power station probability equivalent modeling method | |
| CN111679125B (en) | Method and device for identifying oscillation of power system | |
| CN110098610B (en) | Real-time identification method and system for oscillation leading mode of power system under fault disturbance | |
| CN117013561A (en) | New energy system weak point positioning method and device based on port time domain characteristics | |
| CN108469575A (en) | Power oscillation risk checking method and system of the wind turbine through soft straight power grid transmitting system | |
| CN114792984A (en) | Quick positioning method for subsynchronous/supersynchronous oscillation source | |
| CN104267243A (en) | Method and device for measuring parameters of inner potential and reactance of synchronous generator | |
| CN113722881A (en) | Generator phase-advancing limit calculation method, device and medium based on parameter identification | |
| CN107991563B (en) | Wind-solar complementary simulation experiment device for power supply and distribution and grid-connected experiment and working method | |
| CN106712000B (en) | The oscillation risks appraisal procedure and device of the access electric system of permanent magnet direct-drive blower | |
| Wang et al. | An Algorithm for Calculating the Parameter Selection Area of a Doubly-Fed Induction Generator Based on the Guardian Map Method | |
| CN111682532A (en) | Excitation system uncompensated phase-frequency characteristic online modeling method and storage medium |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |