CN-113644689-B - Method and device for constructing running stability domain of wind power system, electronic equipment and readable storage medium of electronic equipment

CN113644689BCN 113644689 BCN113644689 BCN 113644689BCN-113644689-B

Abstract

The application belongs to the technical field of stability analysis of power systems, and relates to a method and a device for constructing a running stability domain of a wind power system, electronic equipment and a readable storage medium thereof. Firstly, constructing a parameter space of an operation stability domain of a wind power system, constructing an impedance model of each device in a target system, establishing a stability criterion based on aggregate impedance frequency characteristics, determining a stable operation point in the parameter space, searching by taking the point as an initial point to obtain critical stable operation points corresponding to each output value in a single machine output range, and finally, connecting all critical stable operation points to form a stability domain boundary. The application establishes a stable criterion based on the frequency characteristic of the aggregate impedance, and can rapidly and accurately judge the stability of the system subsynchronous/supersynchronous oscillation mode under each operation parameter. The running stability domain of the wind power system is built by the boundary search method, the calculated amount is small, the conservation is low, and guidance can be provided for the subsynchronous oscillation prevention and control and the safe and stable running of the system.

Inventors

XIE XIAORONG
ZHAN YING
LIU WEI
CHAI WEI
Ma Ningjia

Assignees

清华大学
国网上海市电力公司

Dates

Publication Date: 20260508
Application Date: 20210816

Claims (8)

1. The method for constructing the running stability domain of the wind power system is characterized by comprising the following steps of: Constructing a parameter space of an operation stability domain of the wind power system; establishing an all-condition impedance model of a wind turbine generator in a wind power system and impedance of other equipment; The method comprises the steps of establishing a stability criterion based on the frequency characteristic of aggregate impedance, wherein the establishment of the stability criterion based on the frequency characteristic of aggregate impedance comprises the specific processes of calculating the impedance of a wind power system wind power plant under any operation parameter p and n, establishing an impedance network of the wind power system under the current operation parameter p, forming a node admittance matrix of the impedance network, simplifying the impedance network into aggregate impedance to obtain a frequency characteristic curve of the aggregate impedance, judging the stability of a subsynchronous oscillation mode of the wind power system according to the frequency characteristic curve of the aggregate impedance, wherein the construction of a wind power system operation stability domain parameter space comprises the steps of taking the output of a single wind power unit and the number of grid-connected fans of the wind power system as parameters for constructing an operation stability domain, setting a value range of the operation parameter of the wind power system, recording the output interval of the single wind power unit in the wind power system as [ p low ,p high ] and recording the number interval of the grid-connected fans as [ n low ,n high ]; Searching a critical stable operating point in a parameter space; Searching critical stable operating points; All critical stable operating points are connected to form a stable domain boundary.
2. The method for constructing the running stability domain of the wind power system according to claim 1, wherein the step of establishing the impedance model of the wind turbine generator set and the impedance of other devices in the wind power system comprises the following steps: establishing an all-condition impedance model of the wind turbine generator, impedance of wind turbine generator set Expressed as a function of operating point: And calculating the impedance of other equipment by adopting a mechanism deduction or external characteristic identification method.
3. The method for constructing a running stability domain of a wind power system according to claim 1, wherein searching for a critical stable running point in a parameter space comprises: Setting the searching step length of the number of the grid-connected fans as delta n; Respectively setting the output of a single wind power unit and the number of grid-connected fans as minimum values to serve as a stable operating point, wherein the output active power p=p low of the single wind power unit of the wind power system at the moment, and the number n=n low of the grid-connected fans; And (3) keeping p unchanged, gradually increasing the number N of grid-connected fans by a step length delta N, judging the stability of the subsynchronous/supersynchronous oscillation modes under each operation parameter according to the stability criterion based on the polymerization impedance frequency characteristic, if the subsynchronous/supersynchronous oscillation modes in the wind power system are changed from stable abrupt change to unstable state, recording the number of grid-connected fans before abrupt change as N, and if the subsynchronous/supersynchronous oscillation modes in the wind power system are kept stable, enabling N=n high (p, N) to be a critical stable operation point.
4. The method for constructing a wind power system operation stability domain according to claim 1, wherein searching for a critical stable operation point comprises: 6-1, setting the output search step length of a single wind motor unit as delta p; 6-2 let p=p t +△p,n=N t ; 6-3, judging the stability of the subsynchronous oscillation mode of the target wind power system when the operation parameter is (p, n) according to the stability criterion based on the polymerization impedance frequency characteristic: If the frequency characteristic is stable, the number N of the grid-connected fans is gradually increased by the step delta N, the stability of the subsynchronous/supersynchronous oscillation modes under each operation parameter is further judged according to the stability criterion based on the frequency characteristic of the polymerization impedance, if the subsynchronous/supersynchronous oscillation mode is changed from stable to unstable, the number of the grid-connected fans before the mutation is recorded as N, (p, N) to be a critical stable operation point, t=t+1, P t =p,N t =N, if the subsynchronous/supersynchronous oscillation mode is stable, N=n high , (p, N) to be a critical stable operation point, t=t+1, P t =p,N t =N; If the frequency of the grid-connected fans is unstable, keeping p unchanged, gradually reducing the number N of the grid-connected fans by a step length delta N, judging the stability of the sub/super synchronous oscillation modes under each operation parameter according to the stability criterion based on the polymerization impedance frequency characteristic, if the sub/super synchronous oscillation modes are changed from unstable to stable, recording the number of the grid-connected fans at the moment as N, (p, N) as critical stable operation points, enabling t=t+1, P t =p,N t =N, and if the sub/super synchronous oscillation modes are kept unstable, returning to the step (6-2); 6-4 steps 6-2-6-3 are repeated until P t =p high .
5. The device for constructing the running stability domain of the wind power system is characterized by comprising the following components: the parameter space module is used for constructing a parameter space of an operation stability domain of the wind power system; the impedance calculating module is used for establishing an all-condition impedance model of the wind turbine generator in the wind power system and impedance of other equipment; The method comprises the steps of (1) calculating the impedance of a wind power system wind power plant under any operation parameter p and n, establishing an impedance network of the wind power system under the current operation parameter p and forming a node admittance matrix of the impedance network, simplifying the impedance network into the aggregation impedance to obtain a frequency characteristic curve of the aggregation impedance, judging the stability of a sub/super synchronous oscillation mode of the wind power system according to the frequency characteristic curve of the aggregation impedance, wherein the step of constructing a parameter space of an operation stable domain of the wind power system comprises the steps of (1) taking the output of a single wind power motor group in the wind power system and the number of grid-connected fans of the wind power plant as parameters for constructing the operation stable domain, (2) setting the value range of the operation parameters of the wind power system, recording the output interval of the single wind power motor group in the wind power system as [ p low ,p high ], and recording the number interval of the grid-connected fans as [ n low ,n high ]; the searching module is used for searching a critical stable operating point in one stable operating point in the parameter space; the searching module is used for searching critical stable operating points; The connection module is used for connecting all critical stable operation points to form a stable domain boundary.
6. The device for constructing the operation stability domain of the wind power system according to claim 5, wherein the criterion establishing module comprises: the first calculation unit is used for calculating the impedance of the wind power system wind power plant under any operation parameter; the impedance network forming unit is used for establishing an impedance network of the wind power system under the current operation parameters and forming a node admittance matrix of the impedance network; a second calculation unit, configured to simplify the impedance network into an aggregate impedance, and obtain a frequency characteristic of the aggregate impedance; and the judging unit is used for judging the stability of the subsynchronous oscillation mode of the wind power system according to the frequency characteristic curve of the aggregation impedance.
7. An electronic device, comprising: a memory for storing computer-executable instructions; A processor configured to perform the method of constructing a wind power system operational stability domain of any of claims 1-4.
8. A computer-readable storage medium, characterized in that the computer-readable storage medium has stored thereon a computer program for causing the computer to execute the method for constructing the operational stability domain of the wind power system according to any one of claims 1 to 4.

Description

Method and device for constructing running stability domain of wind power system, electronic equipment and readable storage medium of electronic equipment Technical Field The application belongs to the technical field of stability analysis of power systems, and relates to a method and a device for constructing a running stability domain of a wind power system, electronic equipment and a readable storage medium thereof. Background In recent years, the permeability of wind power is continuously improved, and novel subsynchronous oscillation accidents such as subsynchronous oscillation and supersynchronous oscillation of a north China Guyuan wind power base and a Xinjiang Hami wind power station occur in a power system, which reduce the quality of electric energy, destroy the safety of equipment and endanger the reliable operation of a power grid. In order to analyze the oscillation stability of the wind power system under different operation parameters and measure the stability margin of the system, an operation stability domain of the system needs to be constructed, and important information is provided for preventing and controlling secondary/super-synchronous oscillation. The existing wind power system stability domain facing subsynchronous oscillation prevention and control is mostly a parameter stability domain, namely, the influence of system structural parameters and controller parameters on subsynchronous oscillation stability is considered. Because the subsynchronous oscillation stability of the wind power system is closely related to the running point of the system, the existing parameter stability domain is difficult to provide guidance for safe and stable running of the system. In consideration of the fact that the wind power system is generally complex, all characteristic values of the system are calculated based on a time domain state space model, and then the calculated amount of the method for judging the oscillation stability according to the positive and negative of the real part of the characteristic values is large, even the problem of dimension disaster exists, Disclosure of Invention In view of this, the present disclosure proposes a method and apparatus for constructing a wind power system operation stability domain, an electronic device and a readable storage medium thereof, so as to solve the problems in the related art. According to a first aspect of the present disclosure, a method for constructing an operation stability domain of a wind power system is provided, including: Constructing a parameter space of an operation stability domain of the wind power system; establishing an all-condition impedance model of a wind turbine generator in a wind power system and impedance of other equipment; Establishing a stability criterion based on the aggregate impedance frequency characteristic; Searching a critical stable operating point in a parameter space; Searching critical stable operating points; All critical stable operating points are connected to form a stable domain boundary. Optionally, the building the running stability domain parameter space of the wind power system includes: Taking the output of a single wind motor unit and the number of grid-connected fans of a wind power plant in a wind power system as parameters for constructing an operation stability domain; Setting the value range of the operation parameters of the wind power system, recording the output interval of a single wind motor set in the wind power system as [ p low,phigh ], and recording the number interval of the grid-connected fans as [ n low,nhigh ]. Optionally, establishing an impedance model of all working conditions of the wind turbine generator in the wind power system and impedance of other devices includes: establishing an all-condition impedance model of the wind turbine generator, and expressing the impedance Z WTG(s) of the wind turbine generator as a function of the working point: And calculating the impedance of other equipment by adopting a mechanism deduction or external characteristic identification method. Optionally, the establishing a stability criterion based on the aggregate impedance frequency characteristic comprises the following specific procedures: Calculating the impedance of a wind power system wind power plant under any operation parameter (p, n); establishing an impedance network of the wind power system under the current operation parameters, and forming a node admittance matrix of the impedance network; simplifying the impedance network into an aggregate impedance to obtain the frequency characteristic of the aggregate impedance; And judging the stability of the subsynchronous oscillation mode of the wind power system according to the frequency characteristic curve of the aggregation impedance. Optionally, the searching the critical stable operation point in the parameter space includes: Setting the searching step length of the number of the grid-connected fans as delta n; Respective