CN-115481545-B - Analysis method and device for stable oscillation, electronic equipment and storage medium

CN115481545BCN 115481545 BCN115481545 BCN 115481545BCN-115481545-B

Abstract

The application discloses an analysis method, a device, electronic equipment and a storage medium for oscillation stability, which are applied to the electronic equipment, and particularly comprise the steps of calculating impedance values of all elements in a new energy power system at a plurality of predetermined frequency sampling points, calculating a system aggregation impedance determinant and impedance sampling values thereof seen from observation nodes based on all the impedance values, performing approximate fitting on the system aggregation impedance determinant and the impedance sampling values thereof by using an s-domain rational function with known analysis expressions by using a VF algorithm on the basis of determining an upper bound and a lower bound, calculating AIC criterion indexes at the upper bound and the lower bound respectively, searching a minimum value point of the AIC criterion indexes by using a binary method, taking the minimum value point as an estimation order, and calculating the s-domain rational function by using the VF algorithm under the estimation order to obtain a zero point set of the s-domain rational function, wherein the zero point set comprises quantitative information of the new energy power system in an oscillation mode.

Inventors

DAN YANGQING
DING YIFAN
LIN LING
CHEN QINGYUE
WANG CHENXUAN
ZHENG WEIMIN
HE YINGJING
WANG ZHEN
WANG LEI
SUN FEIFEI
WU JIAHUI
GU CHENLIN
XU ENCHAO

Assignees

国网浙江省电力有限公司经济技术研究院

Dates

Publication Date: 20260508
Application Date: 20221020

Claims (8)

1. The analysis method with stable oscillation is applied to electronic equipment and is used for calculating a plurality of quantitative information in a new energy power system, and is characterized by comprising the following steps: calculating impedance values of all elements in the new energy power system at a plurality of predetermined frequency sampling points, and calculating a system aggregate impedance determinant and impedance sampling values thereof seen from an observation node based on all the impedance values; Based on the determination of an upper bound and a lower bound, an s-domain rational function with a known analytical expression is used for a VF algorithm to approximately fit the system aggregate impedance determinant and the impedance sampling values thereof, and AIC criterion indexes at the upper bound and the lower bound are calculated respectively, wherein the upper bound is N U , the lower bound is N L , and the upper bound and the lower bound are required to meet delta AIC (N L ) <0 and delta AIC (N U ) >0 and N U -N L > >1; Searching a minimum value point of the AIC criterion index by using a difference and dichotomy of the AIC criterion index, taking the minimum value point as an estimation order, wherein the difference delta AIC (N) =AIC (N+1) -AIC (N) of the AIC criterion index, AIC (N+1) and AIC (N) are AIC criterion indexes, and N is an order; And under the estimated order, calculating the s-domain rational function by using a VF algorithm to obtain a zero point set of the s-domain rational function, wherein the zero point set comprises quantitative information of the new energy power system in an oscillation mode.
2. The method of resolving claim 1 wherein the calculating impedance values of each element in the new energy power system at a plurality of predetermined frequency sampling points and calculating a system aggregate impedance determinant and its impedance sampling values as seen from the observation node based on all the impedance values comprises the steps of: selecting a plurality of discrete frequency sampling points within the selected frequency range; Establishing an impedance model of each external power grid element according to current/voltage input/output external characteristics of a plurality of external power grid elements in the new energy power system, and calculating an impedance value of each external power grid element at each frequency sampling point based on the impedance model; connecting a plurality of external power grid elements based on the selected observation node to form an impedance network model, so as to obtain the system aggregate impedance determinant; and performing serial-parallel connection calculation on the system aggregate impedance determinant to obtain the impedance sampling value.
3. The parsing method of claim 1, wherein a real part of the zero represents a damping coefficient of a corresponding oscillation mode, and an imaginary part of the zero represents an oscillation angular frequency.
4. An analysis device with stable oscillation is applied to electronic equipment and is used for calculating a plurality of quantitative information in a new energy power system, and is characterized in that the analysis device comprises: A first calculation module configured to calculate impedance values of elements in the new energy power system at a plurality of predetermined frequency sampling points, and calculate a system aggregate impedance determinant and impedance sampling values thereof seen from an observation node based on all the impedance values; The fitting processing module is configured to approximately fit an s-domain rational function with a known analytical expression to the system aggregate impedance determinant and the impedance sampling value thereof by using a VF algorithm on the basis of determining an upper bound and a lower bound, and respectively calculate AIC criterion indexes at the upper bound and the lower bound, wherein the upper bound is N U , the lower bound is N L , and the upper bound and the lower bound are required to meet delta AIC (N L ) <0 and delta AIC (N U ) >0 and N U -N L > >1; The second calculation module is configured to find a minimum value point of the AIC criterion index by using a difference and a dichotomy of the AIC criterion index, the minimum value point is used as an estimation order, the difference delta AIC (N) =AIC (N+1) -AIC (N) of the AIC criterion index, AIC (N+1) and AIC (N) are AIC criterion indexes, and N is an order; And the analysis processing module is configured to calculate the s-domain rational function by utilizing a VF algorithm under the estimated order to obtain a zero point set of the s-domain rational function, wherein the zero point set comprises quantitative information of the new energy power system in an oscillation mode.
5. The parsing apparatus of claim 4, wherein said first calculation module comprises: A sampling point selection unit configured to select a plurality of discrete frequency sampling points within a selected frequency band range; A first calculation unit configured to establish an impedance model of each external power grid element according to current/voltage input/output external characteristics of a plurality of external power grid elements in the new energy power system, and calculate an impedance value of each external power grid element at each frequency sampling point based on the impedance model; A model building unit configured to connect a plurality of the plurality of external grid elements to form an impedance network model based on the selected observation nodes, resulting in the system aggregate impedance determinant; And the second calculation unit is configured to perform serial-parallel connection calculation on the system aggregate impedance determinant to obtain the impedance sampling value.
6. The resolving apparatus of claim 4, wherein the real part of the zero represents a damping coefficient of a corresponding oscillation mode and the imaginary part of the zero represents an oscillation angular frequency.
7. An electronic device comprising at least one processor and a memory coupled to the processor, wherein: The memory is used for storing a computer program or instructions; the processor is configured to execute the computer program or instructions to cause the electronic device to implement the oscillation stabilization analysis method according to any one of claims 1 to 3.
8. A storage medium for use in an electronic device, wherein the storage medium carries one or more computer programs executable by the electronic device to cause the electronic device to implement the oscillation stabilization analysis method according to any one of claims 1 to 3.

Description

Analysis method and device for stable oscillation, electronic equipment and storage medium Technical Field The present application relates to the field of power technologies, and in particular, to an oscillation stabilization analysis method, an oscillation stabilization analysis device, an electronic device, and a storage medium. Background Along with the development of power technology and the powerful construction of new energy, high-proportion new energy and high-proportion power electronic equipment are becoming important characteristics of a power system, the characteristics of the power system which is traditionally dominated by synchronous machines are obviously changed by the new energy equipment taking power electronics as an interface, and meanwhile, the phenomenon of oscillation instability of a power grid can be caused by the interaction between the addition of a large number of new energy equipment and the power grid. The impedance method in the frequency domain theory is the most commonly used method for analyzing the oscillation stability problem of the new energy power system, and a typical technical route is that according to the characteristics of new energy equipment and various power grid elements, an impedance model of each element is built in a complex frequency domain by a mechanism modeling method or an external measuring and distinguishing method, an impedance network of the new energy power system is built by combining a power grid topology, the impedance network is split into two independent subsystems at a certain observation node (usually a port of the new energy equipment), the aggregation impedance seen by the observation node of the two subsystems is calculated respectively, and the oscillation stability of the new energy power system is analyzed based on a Nyquist curve of the ratio of the aggregation impedance of the two subsystems. However, only qualitative stable conclusion can be obtained based on the nyquist criterion, and quantitative information such as damping coefficient, oscillation frequency and the like of the oscillation mode of the power system is difficult to obtain. Disclosure of Invention In view of the above, the present application provides an analysis method, an apparatus, an electronic device, and a storage medium for stable oscillation, which are used to obtain quantitative information in an oscillation mode of a new energy power system. In order to achieve the above object, the following solutions have been proposed: An analysis method with stable oscillation is applied to electronic equipment and is used for calculating a plurality of quantitative information in a new energy power system, and the analysis method comprises the following steps: calculating impedance values of all elements in the new energy power system at a plurality of predetermined frequency sampling points, and calculating a system aggregate impedance determinant and impedance sampling values thereof seen from an observation node based on all the impedance values; Based on the determination of an upper bound and a lower bound, an s-domain rational function with a known analytical expression is used for a VF algorithm to perform approximate fitting on the system aggregate impedance determinant and the impedance sampling values thereof, and AIC criterion indexes at the upper bound and the lower bound are calculated respectively; Searching a minimum value point of the AIC criterion index by using a dichotomy, and taking the minimum value point as an estimation order; And under the estimated order, calculating the s-domain rational function by using a VF algorithm to obtain a zero point set of the s-domain rational function, wherein the zero point set comprises quantitative information of the new energy power system in an oscillation mode. Optionally, the calculating the impedance value of each element in the new energy power system at a plurality of predetermined frequency sampling points, and calculating the system aggregate impedance determinant and the impedance sampling value thereof seen from the observation node based on all the impedance values, includes the steps of: selecting a plurality of discrete frequency sampling points within the selected frequency range; Establishing an impedance model of each external power grid element according to current/voltage input/output external characteristics of a plurality of external power grid elements in the new energy power system, and calculating an impedance value of each external power grid element at each frequency sampling point based on the impedance model; connecting a plurality of external power grid elements based on the selected observation node to form an impedance network model, so as to obtain the system aggregate impedance determinant; and performing serial-parallel connection calculation on the system aggregate impedance determinant to obtain the impedance sampling value. Optionally, the upper boundary is N U, the lower bo