CN-122026304-A - Short-circuit parameter matrix on-line identification method, system, equipment and medium suitable for active power distribution network

CN122026304ACN 122026304 ACN122026304 ACN 122026304ACN-122026304-A

Abstract

The invention discloses a short-circuit parameter matrix on-line identification method, a system, equipment and a medium suitable for an active power distribution network, belonging to the technical field of power system analysis and control, comprising the steps of determining a key measurement node set based on the topology and the running state of the power distribution network; the method comprises the steps of carrying out synchronous phasor measurement to obtain whole-network electric quantity data, preprocessing the dynamic electric quantity data, establishing an equivalent model of a distributed power supply and an input-output data set, obtaining a system matrix reflecting the input-output relation of a power distribution network through a system identification algorithm, obtaining a short-circuit parameter matrix of the power distribution network through system matrix calculation, verifying the short-circuit parameter matrix, and driving the update of an identification process. According to the invention, an active power distribution network short-circuit parameter online identification system is constructed through collaborative fusion of optimization screening of key measurement nodes and a distributed power supply dynamic equivalent model. The method overcomes the limitation of the traditional dependence on the static model and the complete network parameters, and reduces the implementation and maintenance cost of the system.

Inventors

JIANG SHIXIAO
LI YUGANG
LIAO CHANG
YANG ZHENGXIAO
LUO JINLONG
XIE WEI
LIAO QINGYANG
Fan Junqiu
XIE CAIKE
Du Renren
YUAN LONG
NING NAN
ZHOU YIRAN
CHEN KEYANG
WANG JIAHAO

Assignees

贵州电网有限责任公司

Dates

Publication Date: 20260512
Application Date: 20251205

Claims (10)

1. A short-circuit parameter matrix on-line identification method suitable for an active power distribution network is characterized by comprising the following steps of, Determining a key measurement node set based on the topology and the running state of the power distribution network; On the key measurement node set, synchronous phasor measurement is carried out, and whole-network electric quantity data are obtained; preprocessing dynamic electric quantity data, and establishing an equivalent model of a distributed power supply and an input and output data set; Based on the input and output data set, obtaining a system matrix reflecting the input and output relation of the power distribution network through a system identification algorithm; Obtaining a short-circuit parameter matrix of the power distribution network by resolving a system matrix; And verifying the short-circuit parameter matrix, and based on the verification result and parameter change detection, driving the updating of the identification process.
2. The method for online identification of a matrix of short circuit parameters for an active power distribution network as recited in claim 1, wherein determining a set of critical measurement nodes based on topology and operational status of the power distribution network comprises, Calculating connectivity, load level and distributed power supply access condition of each node based on topology data acquired by a power distribution automation system; Comprehensive connectivity, load level and distributed power supply access condition are synthesized, and comprehensive contribution index of corresponding nodes is calculated and sequenced; based on comprehensive contribution degree sequencing, adopting an iterative screening algorithm to select nodes with large contribution degree and long electrical distance from the selected nodes; And outputting a set of measuring nodes meeting the preset number of requirements.
3. The method for on-line identification of a short-circuit parameter matrix suitable for an active power distribution network as claimed in claim 2, wherein said performing synchronous phasor measurements on a set of key measurement nodes to obtain full-network electrical quantity data comprises, Disposing a synchronous phasor measurement device on the key node, and synchronously collecting voltage and current signals of the node; providing time references for all measuring devices by using a unified clock source, and completing synchronous acquisition; performing conversion processing on the synchronously acquired voltage and current signals to acquire fundamental phasor data; and transmitting the fundamental phasor data to a central station for storage.
4. The method for on-line identification of a short-circuit parameter matrix suitable for an active power distribution network as set forth in claim 3, wherein said preprocessing of the dynamic electrical data to create an equivalent model of the distributed power source and the input and output data set comprises Performing outlier detection and data correction on fundamental phasor data, identifying steady-state operation data segments, and outputting steady-state phasor sequences; acquiring operation data of a distributed power supply, and establishing a dynamic equivalent model of a controlled current source and dynamic impedance in parallel; Performing equivalent correction on node injection quantity and network parameters defined by a steady-state phasor sequence by using a dynamic equivalent model; and combining the data subjected to the equivalent correction to form an input/output data set.
5. The method for on-line identification of a short-circuit parameter matrix suitable for an active power distribution network as claimed in claim 4, wherein the obtaining of a system matrix reflecting the input-output relationship of the power distribution network by a system identification algorithm based on the input-output data set comprises, Constructing an input data matrix and an output data matrix of the system based on the input and output data sets; performing joint processing and matrix decomposition on the input data matrix and the output data matrix, and extracting dominant features of the system; Based on dominant characteristics of the system, a transfer function matrix representing the input-output relationship of the power distribution network is estimated and obtained to serve as a system matrix.
6. The method for online identification of a short-circuit parameter matrix for an active power distribution network of claim 5, wherein said obtaining the short-circuit parameter matrix for the power distribution network from a system matrix solution comprises, Performing inversion operation on the transmission function matrix to obtain a node impedance matrix of the power distribution network; Calculating impedance parameters of each branch based on self impedance and trans impedance in the node impedance matrix; and (5) collecting impedance parameters of all branches to form a short-circuit parameter matrix of the power distribution network.
7. The method for online identification of a short-circuit parameter matrix for an active power distribution network of claim 6, wherein said verifying the short-circuit parameter matrix and based on the verification result and the parameter change detection, the updating of the drive identification process comprises, Performing physical constraint inspection and prediction error analysis on the short-circuit parameter matrix to verify correctness; Storing the short-circuit parameters which pass verification into a database, and comparing the short-circuit parameters with the historical parameters to output a change detection result; based on the verification conclusion and the change detection result, a control instruction is generated to drive the identification process to carry out self-adaptive updating.
8. An on-line identification system of a short-circuit parameter matrix suitable for an active power distribution network, which is applied to the on-line identification method of the short-circuit parameter matrix suitable for the active power distribution network according to any one of claims 1-7, and is characterized by comprising a power distribution network topology module, a data collection module, a preprocessing module, an input/output module, a calculation module and an updating module; The power distribution network topology module is used for determining a key measurement node set based on the topology and the running state of the power distribution network; the data collection module is used for carrying out synchronous phasor measurement on the key measurement node set to obtain whole-network electric quantity data; The preprocessing module is used for preprocessing dynamic electric quantity data and establishing an equivalent model of the distributed power supply and an input and output data set; The input/output module is based on an input/output data set, and a system matrix reflecting the input/output relation of the power distribution network is obtained through a system identification algorithm; the calculation module obtains a short-circuit parameter matrix of the power distribution network through system matrix calculation; the updating module is used for verifying the short-circuit parameter matrix, detecting the parameter change based on a verification result and driving the updating of the identification process.
9. A computer device comprising a memory and a processor, the memory storing a computer program, characterized in that the processor, when executing the computer program, implements the steps of a method for on-line identification of a matrix of short-circuit parameters suitable for an active distribution network according to any one of claims 1 to 7.
10. A computer readable storage medium, on which a computer program is stored, characterized in that the computer program, when being executed by a processor, implements the steps of a method for on-line identification of a matrix of short-circuit parameters suitable for use in an active power distribution network according to any one of claims 1 to 7.

Description

Short-circuit parameter matrix on-line identification method, system, equipment and medium suitable for active power distribution network Technical Field The invention relates to the technical field of power system analysis and control, in particular to a short-circuit parameter matrix on-line identification method, system, equipment and medium suitable for an active power distribution network. Background With the large-scale access of distributed energy sources, the traditional power distribution network gradually changes to an active power distribution network, and the network topology and the electrical characteristics are obviously changed. The existing short-circuit parameter calculation method is mainly based on a static model of a power grid and a centralized power supply assumption, and cannot accurately reflect dynamic characteristics and influences of a distributed power supply. The traditional method mainly has the following defects that firstly, dynamic response characteristics of the distributed power supply, such as a converter control strategy and a power supply type difference, are ignored, secondly, influence changes of the distributed power supply on a short circuit network under different operation modes are not considered, thirdly, an offline calculation mode is mostly adopted, the characteristic that the dynamic changes of an active power distribution network cannot be adapted, thirdly, the calculation process generally needs complete network parameters and topology information, and in practical application, comprehensive and accurate data are difficult to obtain. In addition, although the existing identification method based on measurement can avoid partial modeling errors, the method is mainly aimed at the traditional power distribution network design, and has the problems of insufficient precision and poor adaptability when a large number of distributed power supplies are accessed. Disclosure of Invention The present invention has been made in view of the above-described problems. Therefore, the invention solves the technical problem of overcoming the defects of the traditional offline calculation method under the background that the distributed power supply is accessed in a large scale to cause the dynamic change of the topology and the electrical characteristics of the power distribution network. In order to solve the technical problems, the invention provides a short-circuit parameter matrix on-line identification method suitable for an active power distribution network, which comprises the following steps of, Determining a key measurement node set based on the topology and the running state of the power distribution network; On the key measurement node set, synchronous phasor measurement is carried out, and whole-network electric quantity data are obtained; preprocessing dynamic electric quantity data, and establishing an equivalent model of a distributed power supply and an input and output data set; Based on the input and output data set, obtaining a system matrix reflecting the input and output relation of the power distribution network through a system identification algorithm; Obtaining a short-circuit parameter matrix of the power distribution network by resolving a system matrix; And verifying the short-circuit parameter matrix, and based on the verification result and parameter change detection, driving the updating of the identification process. As a preferred scheme of the short-circuit parameter matrix on-line identification method suitable for the active power distribution network, the method for determining the key measurement node set based on the topology and the running state of the power distribution network comprises the following steps of, Calculating connectivity, load level and distributed power supply access condition of each node based on topology data acquired by a power distribution automation system; Comprehensive connectivity, load level and distributed power supply access condition are synthesized, and comprehensive contribution index of corresponding nodes is calculated and sequenced; based on comprehensive contribution degree sequencing, adopting an iterative screening algorithm to select nodes with large contribution degree and long electrical distance from the selected nodes; And outputting a set of measuring nodes meeting the preset number of requirements. The invention establishes the contribution index comprehensively considering the node connectivity, the load level and the distributed power supply access condition, and carries out iterative screening based on the electrical distance, so that the global dynamic characteristic of the power distribution network can be captured by a limited measuring point far less than the nodes of the whole network. The method not only reduces the deployment and communication cost of the synchronous measuring device, but also ensures the representativeness and systematicness of the data required for identificati