CN-121984122-A - Power grid new energy bearing capacity evaluation analysis method and device based on safety domain theory

CN121984122ACN 121984122 ACN121984122 ACN 121984122ACN-121984122-A

Abstract

The invention discloses a method and a device for evaluating and analyzing new energy bearing capacity of a power grid based on a safety domain theory, wherein the method collects fault information of a power system and time sequence operation data of a generator, establishes a motion equation based on an inertia center coordinate system, identifies leading and lagging homonymous groups, adjusts the output force of the generator of the leading group, identifies leading instability units and modes, searches critical instability points and determines stability judging reference parameters, adopts a maximum Lyapunov index criterion sensitivity analysis algorithm, combines a stability criterion, a sensitivity matrix, a stability judging formula and constraint conditions to construct a multi-mode practical dynamic safety domain, calculates the stability margin of the system, dynamically adjusts the new energy duty ratio, and circulates and iterates until the stability margin meets preset requirements to output a new energy bearing capacity evaluation value. According to the invention, complex simulation models are not needed to be relied on, transient stability prediction and stability margin quantification are realized in advance, the accuracy and practicality of new energy bearing capacity assessment are improved, and a power-assisted power system is safe and stable to operate.

Inventors

ZENG YUAN
MA YUHUI
REN JUNZHI
QIN CHAO
GAO YIYING
JIANG YILANG
ZHANG JIAN
SHAO CHONG
MA XIPING

Assignees

天津大学
中国电力科学研究院有限公司
国网甘肃省电力公司
国网甘肃省电力公司电力科学研究院

Dates

Publication Date: 20260505
Application Date: 20260116

Claims (12)

1. The power grid new energy bearing capacity evaluation analysis method based on the safety domain theory is characterized by comprising the following steps of: Collecting fault information of a power system and time sequence operation data of a generator after the fault occurs; Establishing a motion equation of the multi-machine power system based on the inertia center coordinate system, calculating the power angle and angular speed deviation of each generator relative to the inertia center coordinate system by utilizing collected generator time sequence operation data, and identifying a leading homomorphic cluster and a lagging homomorphic cluster in the power system by adjusting fault removal time and combining the power angles of the generators; Respectively adjusting the output of each generator in the leading synchronous machine group identified by the motion equation, identifying a dominant destabilizing machine group and a destabilizing mode of the power system based on the output information of the generator in the acquired time sequence operation data, searching a dominant destabilizing critical point and determining a judging reference parameter according to the identified dominant destabilizing machine group and the identified destabilizing mode; at a dominant instability critical point, based on a determined stability judging reference parameter, the collected fault information and generator time sequence operation data adopt a maximum Lyapunov exponent criterion sensitivity analysis algorithm to construct a practical dynamic security domain; And calculating the distance between the boundary of the practical dynamic security domain and the actual running point of the power system to determine a system stability margin, comparing the system stability margin with a preset minimum stability margin requirement, dynamically adjusting the new energy duty ratio of the power system according to a comparison result, and circularly executing the steps of dominant unsteady unit identification, practical dynamic security domain construction and stability margin judgment until the system stability margin meets the preset requirement, and finally obtaining a new energy bearing capacity evaluation value of the power system.
2. The method for evaluating and analyzing the new energy bearing capacity of the power grid based on the safety domain theory according to claim 1, wherein the fault information comprises the position, the type and the fault removal time of the fault, and the time sequence operation data comprises the power angle, the angular speed deviation and the active power data of the generator.
3. The method for evaluating and analyzing the new energy bearing capacity of the power grid based on the safety domain theory according to claim 1, wherein the following relation is satisfied by establishing a motion equation of a multi-machine power system based on an inertia center coordinate system: In the formula, For the angular velocity deviation of the generator i from the inertial center coordinate system, For the angular velocity deviation of the generator i, For the angular velocity deviation of the center of inertia, For the moment of inertia of the generator i, N is the total rotational inertia of the system and n is the total number of generators in the power system.
4. The method for evaluating and analyzing the new energy bearing capacity of the power grid based on the safety domain theory according to claim 1, wherein the specific mode for identifying the dominant destabilizing unit of the power system is as follows: The method comprises the steps of respectively lifting the output of each generator in a leading synchronous machine group to the upper limit of the output, judging that the generator is a dominant destabilizing machine group if a transient destabilization occurs in an electric power system, determining the dominant destabilizing mode of the system according to the number of the dominant destabilizing machine groups, wherein each dominant destabilizing machine group corresponds to one boundary of a practical dynamic security domain; And searching instability critical points for each dominant instability unit by adopting a dichotomy, wherein the instability critical points are dominant instability critical points of the generator, and acquiring critical maximum power and stability judging reference parameters zeta of the power system through the instability critical points.
5. The method for evaluating and analyzing the new energy bearing capacity of the power grid based on the safety domain theory according to claim 1, wherein the specific step of constructing the practical dynamic safety domain by adopting a maximum lyapunov exponent criterion sensitivity analysis algorithm based on the collected fault information and the generator time sequence operation data at the dominant instability critical point comprises the following steps: adopting the angular velocity characteristic value of the maximum Lyapunov exponent track from negative to positive to pass through zero for the first time to replace the maximum Lyapunov exponent value at infinity, and establishing a system stability criterion by combining the stability judging reference parameter; The stability criterion is subjected to injection power sensitivity analysis to construct a sensitivity matrix, and a stability judging formula is deduced based on the linear relation between a stability judging index and the generator output change in a critical stability area; and introducing upper and lower limit constraints of the active force of the generator and the output constraint of the balancing machine, and correcting the stability judging formula to form a multi-mode practical dynamic security domain.
6. The method for evaluating and analyzing the new energy bearing capacity of the power grid based on the safety domain theory according to claim 5, wherein the expression of the stability criterion is: In the formula, Is the stability discrimination value corresponding to the nth generator, The maximum Lyapunov exponent locus of the nth generator is the angular velocity characteristic value from negative to positive passing zero point moment for the first time, Is the stability judging reference parameter corresponding to the nth generator, n is the total number of generators in the power system, when And when the temperature is less than 0, judging that the system is in a stable state.
7. The method for evaluating and analyzing the new energy bearing capacity of the power grid based on the safety domain theory according to claim 6, wherein the sensitivity matrix is defined as follows: In the formula, Is the stability index of the ith generator in the leading synchronous cluster, The injection power of the j-th generator node is represented by A, i is the serial number of the generators in the leading synchronous cluster, j is the serial numbers of all the generators in the power system, and n is the total number of the generators in the power system.
8. The method for evaluating and analyzing the new energy bearing capacity of the power grid based on the safety domain theory according to claim 7, wherein the derived stability judging formula is based on the linear relation between the stability judging index and the generator output change amount in the critical stability area: In the formula, Is the stability discrimination value of the ith generator in the leading synchronous machine group, F is the sensitivity matrix, The output change amount of the j-th generator; The upper and lower limit constraints of the active output of the generator and the output constraint of the balancing machine are introduced, and the corrected stability judging formula is as follows: In the formula, The partial derivative of the power injected by the ith generator for the ith generator stability index, The partial derivative of the stability index of the ith generator to the injection power of the balancing machine, The output change amount of the j-th generator; The expression of the multi-mode practical dynamic security domain is as follows: In the formula, 、 The lower limit and the upper limit of the active output of the j-th generator are respectively, 、 The lower limit and the upper limit of the active force of the balancing machine are respectively, Is the current active force of the balancing machine.
9. The method for evaluating and analyzing the new energy bearing capacity of the power grid based on the safety domain theory according to claim 1, wherein the specific rule for dynamically adjusting the new energy ratio of the power system according to the comparison result is as follows: if the system stability margin is greater than the preset minimum stability margin requirement, the new energy duty ratio is increased and the step of respectively adjusting the output of each generator in the leading homoenergetic cluster is returned; if the system stability margin is smaller than the preset minimum stability margin requirement, the new energy duty ratio is reduced, and the steps of dominant destabilizing unit identification, practical dynamic security domain construction and stability margin judgment are circularly executed until the system stability margin is equal to the preset minimum stability margin requirement, and the new energy duty ratio is a new energy bearing capacity evaluation value.
10. The power grid new energy bearing capacity evaluation and analysis device based on the safety domain theory adopts the power grid new energy bearing capacity evaluation and analysis method based on the safety domain theory as set forth in any one of claims 1 to 9, and is characterized by comprising the following steps: the data acquisition module is used for acquiring fault information of the power system and time sequence operation data of the generator after the fault occurs; The cluster recognition module is used for establishing a motion equation of the multi-machine power system based on the inertia center coordinate system, calculating the power angle and angular speed deviation of each generator relative to the inertia center coordinate system by utilizing the collected generator time sequence operation data, and recognizing a leading synchronous cluster and a lagging synchronous cluster in the power system by adjusting fault removal time and combining the power angles of the generators; The destabilization judging module is used for respectively adjusting the output of each generator in the leading synchronous machine group identified by the motion equation, identifying a leading destabilizing machine group and a destabilizing mode of the power system based on the output information of the generator in the acquired time sequence operation data, searching a leading destabilizing critical point and determining a judgment reference parameter according to the identified leading destabilizing machine group and the destabilizing mode; The safety domain construction module is used for constructing a practical dynamic safety domain by adopting a maximum Lyapunov exponent criterion sensitivity analysis algorithm on the basis of the determined stability judging reference parameters at the dominant instability critical point, wherein the collected fault information and the generator time sequence operation data are acquired; and the bearing capacity evaluation module is used for calculating the distance between the boundary of the practical dynamic security domain and the actual running point of the electric power system to determine the system stability margin, comparing the system stability margin with a preset minimum stability margin requirement, dynamically adjusting the new energy duty ratio of the electric power system according to a comparison result, and circularly executing the steps of dominant instability unit identification, practical dynamic security domain construction and stability margin judgment until the system stability margin meets the preset requirement, and finally obtaining the new energy bearing capacity evaluation value of the electric power system.
11. A storage medium, wherein program code of the grid new energy bearing capacity evaluation analysis method based on the safety domain theory is stored in the storage medium, and the program code is used for executing instructions of the grid new energy bearing capacity evaluation analysis method based on the safety domain theory according to any one of claims 1 to 9.
12. An electronic device comprising a memory and a processor, wherein the processor and the memory are in communication with each other through a bus, and the memory stores program instructions executable by the processor, wherein the processor invokes the program instructions to execute the power grid new energy bearing capacity assessment analysis method based on the safety domain theory according to any one of claims 1 to 9.

Description

Power grid new energy bearing capacity evaluation analysis method and device based on safety domain theory Technical Field The invention belongs to the technical field of power systems, and particularly relates to a method and a device for evaluating and analyzing new energy bearing capacity of a power grid based on a safety domain theory. Background The safe and stable operation of the power system is a global common problem related to economic development and social stability, and has been a high concern for personnel in the power industry for many years. The traditional transient stability analysis mostly adopts a time domain simulation method, and is widely applied to the works of planning, designing, running and the like of a power system due to intuitiveness. However, with the advancement of low-carbonization transformation of electric power systems, the proportion of renewable energy sources rises year by year, and the development of electric power electronic electric power systems not only increases the complexity of safety and stability analysis, but also greatly depends on the accurate construction of models. Because the simulation model and the actual system have deviation and are difficult to cross-verify, the simulation result can show a certain deviation. Therefore, with the development of a Phasor Measurement Unit (PMU) and a Wide Area Measurement System (WAMS), real-time collection of generator response data has become possible, and the method gets rid of excessive dependence on a complex power system model, and enables power system schedulers to extract transient stability information and characteristics by depending on response track information, so as to establish a mathematical model or criterion related to the transient stability of the system. The Lyapunov exponent characterizes the average exponential convergence or divergence rate between adjacent tracks in space of the system, and is a key tool for researching the stability and chaotic behavior of a nonlinear power system. In the prior art, although a great deal of research results are obtained by using MLE to evaluate transient stability of the power system, in the practical application process, the MLE criterion can only passively reflect the unstable state of the power system, transient instability may have occurred in a reliable stability evaluation time window, and sufficient prediction capability is lacking. Although the MLE criterion can accurately judge the dynamic behavior of the system in a longer time after disturbance, the MLE criterion cannot quantify the stability margin, cannot provide reference for the bearing capacity evaluation of new energy, and limits the application value of the MLE criterion in the dispatching operation of an actual power system. Disclosure of Invention Therefore, the invention provides a method and a device for evaluating and analyzing the new energy bearing capacity of a power grid based on a safety domain theory, which solve the problems that the traditional time domain simulation model is excessively dependent, MLE criteria lack predictability and stability margin quantification capability, and the new energy high-proportion grid-connected scene is difficult to adapt. In order to achieve the above purpose, the invention provides a technical scheme that in a first aspect, a new power grid energy bearing capacity assessment analysis method based on a safety domain theory is provided, comprising the following steps: Collecting fault information of a power system and time sequence operation data of a generator after the fault occurs; Establishing a motion equation of the multi-machine power system based on the inertia center coordinate system, calculating the power angle and angular speed deviation of each generator relative to the inertia center coordinate system by utilizing collected generator time sequence operation data, and identifying a leading homomorphic cluster and a lagging homomorphic cluster in the power system by adjusting fault removal time and combining the power angles of the generators; Respectively adjusting the output of each generator in the leading synchronous machine group identified by the motion equation, identifying a dominant destabilizing machine group and a destabilizing mode of the power system based on the output information of the generator in the acquired time sequence operation data, searching a dominant destabilizing critical point and determining a judging reference parameter according to the identified dominant destabilizing machine group and the identified destabilizing mode; at a dominant instability critical point, based on a determined stability judging reference parameter, the collected fault information and generator time sequence operation data adopt a maximum Lyapunov exponent criterion sensitivity analysis algorithm to construct a practical dynamic security domain; And calculating the distance between the boundary of the practical dynamic security d