CN-121984020-A - Coordinated damping control method and system for multi-grid equipment of power system

CN121984020ACN 121984020 ACN121984020 ACN 121984020ACN-121984020-A

Abstract

The invention relates to the field of control of power systems, in particular to a coordinated damping control method and a coordinated damping control system for multi-grid equipment of a power system, wherein the method comprises the steps of carrying out modal identification on local power grid data acquired by the grid equipment to obtain a dominant oscillation mode and equivalent stiffness; the method comprises the steps of determining target virtual inertia and target virtual damping of a power system under various constraints, obtaining participation weights of network construction equipment based on centerless communication diagrams of the network construction equipment, constructing a global optimization function by taking the participation weights, the virtual inertia to be solved and the virtual damping to be solved of the network construction equipment as parameters, and carrying out iterative solution on the global optimization function by adopting a distributed original-dual iterative algorithm and a dynamic average consistency mechanism to obtain the virtual inertia and the virtual damping of the network construction equipment, wherein the network construction equipment operates based on the virtual inertia and the virtual damping.

Inventors

SUN JIXIN
XU YANZHAO
WU JINGMING
PENG CHEN
Fuck movie
Bian Bajiba
Qiong Zhuoma
Zhao Puchuan
Tan hisayoshi
ZHOU HUI
KONG WEIKANG
ZHAO WENTAO
ZHANG BOQI
CHEN SILIN
HUANG YUANYONG
ZENG YI
LI CHAOBING
XU JIANGBO

Assignees

国网西藏电力有限公司电力科学研究院
西藏中试电力科学技术服务服务有限责任公司
国网西藏电力有限公司

Dates

Publication Date: 20260505
Application Date: 20251231

Claims (10)

1. A coordinated damping control method for a multi-grid device of an electrical power system, comprising: carrying out modal identification on local power grid data acquired by networking equipment to obtain a dominant oscillation mode, and analyzing the dominant oscillation mode to obtain equivalent stiffness of the power system; determining a target virtual inertia and a target virtual damping of the power system based on the equivalent stiffness, the upper limit constraint of the frequency change rate, the frequency constraint and the capacity constraint of the networking equipment in the dominant oscillation mode; acquiring participation weights of all networking devices based on rated capacity, charge state and pre-constructed centerless communication graphs of all networking devices; The participation weight, the virtual inertia to be solved and the virtual damping to be solved of each device are taken as parameters to construct a global optimization function of each networking device, wherein the virtual inertia to be solved of each networking device is the target virtual inertia, and the virtual damping to be solved of each networking device is the target virtual damping; And carrying out iterative solution on the global optimization function by adopting a distributed original-dual iterative algorithm and a dynamic average consistency mechanism to obtain virtual inertia and virtual damping of each network construction device, wherein each network construction device operates based on the virtual inertia and the virtual damping.
2. The coordinated damping control method for a multi-grid device of a power system according to claim 1, wherein the step of performing modal identification on local grid data collected by the grid device to obtain a dominant oscillation mode comprises: Constructing a modal model by adopting a modal identification algorithm based on local power grid data acquired by networking equipment and calculating an optimal model order by adopting an information criterion; Acquiring a mode corresponding to the optimal model order, namely a dominant vibration mode; Preferably, the mode identification algorithm is one or more of Prony algorithm, AR (p) model, ARMA model, covariance driving random subspace method and characteristic system implementation algorithm, and the local power network data comprises local frequency, frequency change rate and active power.
3. The coordinated damping control method for a multi-grid device of a power system according to claim 1 or 2, further comprising, before performing the mode identification on the local grid data collected by the grid device: performing one or more of band-pass filtering, trending processing, windowing processing or energy threshold judgment on the local power grid data; Preferably, the coordinated damping control method further comprises the steps of continuously executing a coordination algorithm by the residual connection subgraphs when partial neighbor disconnection of the networking equipment is monitored based on local power grid data, locking the last effective parameter by the disconnection node, and executing limiting; and entering a safe mode when the network construction equipment is monitored to be completely out of connection with all neighbors.
4. The coordinated damping control method for a multi-grid device of a power system according to claim 1, wherein the analysis of the dominant oscillation mode obtains an equivalent stiffness of the power system, specifically: Extracting the natural frequency of the dominant oscillation mode; inverting the equivalent stiffness of the power system by adopting a linearization system model based on the natural frequency; Preferably, inverting the equivalent stiffness of the power system using the formula; Wherein, the For an equivalent stiffness, the stiffness of the material is, For the total virtual inertia of the current system, N is the total number of networking devices, For the virtual inertia of the current ith networking device, Is a natural frequency.
5. The coordinated damping control method for a multi-grid device of a power system according to claim 1, wherein the determining a target virtual inertia and a target virtual damping of a power system based on the equivalent stiffness, the upper limit constraint on the rate of change of frequency, the frequency constraint, and the capacity constraint of a grid device in the dominant oscillation mode comprises: obtaining a lower limit of the target virtual inertia based on a maximum frequency change rate and an expected maximum disturbance power specified by a grid-connected standard; obtaining an upper limit of a target virtual inertia and an upper limit of a target virtual damping based on capability constraints of the networking devices, wherein the capability constraints comprise capacity, energy storage energy budget or thermal limit of each networking device; Determining a target damping ratio based on the frequency nadir tolerance or the desired frequency recovery time; Determining a target virtual damping based on the target damping ratio and the equivalent stiffness; preferably, the target virtual inertia The lower limit of (2) is: Wherein, the In order to expect the maximum disturbance power, Maximum frequency change rate specified for grid-connected standards; The target virtual inertia The upper limit of (2) is: Wherein, the In order to build the total number of devices in the net, Rated virtual inertia of the ith networking equipment; Target virtual damping The upper limit of (2) is: Wherein, the Is the first Rated virtual damping of the table network equipment; Target virtual damping The calculation formula of (2) is as follows: Wherein, the In order to achieve the target damping ratio, Is equivalent stiffness; Or the target virtual damping The calculation formula of (2) is as follows: Wherein, the Is that Is a conservative estimate of the number of (1), In order to achieve the target damping ratio, For an equivalent stiffness, the stiffness of the material is, Is the target virtual inertia.
6. The coordinated damping control method for a multi-grid device of a power system according to claim 1, wherein the participation weight is calculated as: Wherein, the Is the first The participation weight of the individual networking devices, Is the first The rated capacity of the individual-meshed devices, In order to map the function of the function, Is the first Preferably, the mapping function is a piecewise linear function or an S-shaped curve function; or the calculation formula of the participation weight is as follows: Wherein, the As the priority weight of the priority class, 。
7. The coordinated damping control method for multi-networking equipment of a power system according to claim 1, wherein the global optimization function of each networking equipment is constructed by taking the participation weight, the virtual inertia to be solved and the virtual damping to be solved of each equipment as parameters, specifically: Constructing a local convex quadratic cost function of each networking device by taking the participation weight, the virtual inertia to be solved and the virtual damping to be solved of each device as parameters; Constructing a global optimization function by taking the minimization of the sum of the local convex quadratic cost functions of each networking device as a target; preferably, the global optimization function is: Wherein, the In order to be able to solve for the virtual inertia, To be virtually damped, N is the total number of networking devices, Is the first Local convex quadratic cost functions of the individual networking devices; Preferably, wherein Local convex quadratic cost function of personal networking equipment The expression of (2) is: Wherein, the As an initial reference value for the virtual inertia, As an initial reference value for the virtual damping, And In order to adjust the coefficient of the light source, Is the first Participation weight of the individual networking equipment; Or alternatively Wherein, the And As the weight coefficient of the light-emitting diode, In order to store energy for the life of the device, Is the running cost.
8. The coordinated damping control method for a multi-grid device of a power system of claim 1, further comprising assigning virtual inertia and virtual damping to each grid device such that each grid device operates under the virtual inertia and virtual damping, and executing a protection mechanism during operation, the protection mechanism comprising one or more of power clipping, anti-saturation processing, and SOC protection. Preferably, the coordinated damping control method further comprises the steps that in the running process of each networking device under the virtual inertia and the virtual damping, when a specific event is detected, the virtual inertia and the virtual damping are calculated again when a trigger condition is met, wherein the specific event comprises one or more of communication topology change, modal drift, device capacity change, significant disturbance or periodic refreshing; preferably, the manner of re-performing the calculation of the virtual inertia and the virtual damping includes one of the following: Hot start, calculate with last convergence value as iteration initial value; performing hierarchical response, and updating partial or global configuration according to the severity of the event; And smoothly switching, performing control by using the old parameters, and adopting first-order filtering balance transition after convergence.
9. The coordinated damping control method for multi-grid equipment of a power system according to claim 1 is characterized in that the triggering condition when the global optimization function is solved iteratively by adopting a distributed original-dual iterative algorithm and a dynamic average consistency mechanism is that the difference value of two iterations is larger than a preset value and the time difference from the last broadcast is larger than a preset time.
10. A coordinated damping control system for a multi-grid device of an electrical power system, comprising: The modal sensing unit is used for carrying out modal identification on local power grid data acquired by the networking equipment to obtain a dominant oscillation mode, and analyzing the dominant oscillation mode to obtain equivalent stiffness of the power system; a target calculation unit for determining a target virtual inertia and a target virtual damping of the power system based on the equivalent stiffness, the upper limit constraint of the frequency change rate, the frequency constraint, and the capacity constraint of the networking equipment in the dominant oscillation mode; the weight acquisition unit is used for acquiring the participation weight of each networking device based on the rated capacity and the charge state of each networking device and a pre-constructed centerless communication graph of each networking device; The construction unit is used for constructing a global optimization function of each networking device by taking the participation weight, the virtual inertia to be solved and the virtual damping to be solved of each device as parameters, wherein the virtual inertia to be solved of each networking device is the target virtual inertia, and the virtual damping to be solved of each networking device is the target virtual damping; And the distributed solving unit is used for carrying out iterative solving on the global optimization function by adopting a distributed original-dual iterative algorithm and a dynamic average consistency mechanism to obtain virtual inertia and virtual damping of each networking device.

Description

Coordinated damping control method and system for multi-grid equipment of power system Technical Field The invention relates to the field of control of power systems, in particular to a coordinated damping control method and system for multi-grid equipment of a power system. Background Along with the continuous improvement of the permeability of new energy sources such as photovoltaic, wind power and the like in an electric power system, the traditional synchronous generator gradually exits, and the rotational inertia and the damping level of the system are obviously reduced. Under the background, a Grid-formed (GFM) converter based on voltage source control becomes an important supporting device of a novel power system because the GFM converter can actively support the voltage and frequency of a power Grid. A grid-tied converter typically simulates the inertia and damping characteristics of a synchronous machine by Virtual Synchronous Generator (VSG) technology, the power-frequency dynamics of which can be expressed as: , wherein, For the virtual inertia to be a virtual inertia,Is a virtual damping coefficient, which is a virtual damping coefficient,In order for the angular frequency deviation to be a function of,AndReference power and electromagnetic power, respectively. But this technique has the disadvantage of 1) lacking a system level damping optimization objective. The prior method adopts fixed、Adaptive adjustment of parameters or based on local frequency, failing to provide an overall damping ratio of the systemOr modal characteristics as optimization targets, resulting in the problem that excessive oscillations or RoCoF (frequency change rate) overscaling may occur under large disturbances. 2) Depending on the central controller architecture. The traditional multi-machine coordination method generally needs an Energy Management System (EMS) or a central controller to collect global information and issue control instructions, and has the problems of single-point failure risk, heavy communication burden, poor expandability and the like. 3) Device heterogeneity and fairness are not fully considered. In actual operation, the capacity, the energy storage SOC (state of charge), the temperature, the altitude and other conditions of each networking device are obviously different, if inertia and damping tasks are simply distributed according to the capacity proportion, overload of some devices and insufficient utilization rate of other devices may be caused, and the overall performance of the system and the service life of the devices are affected. The prior art is rarely provided with systematic schemes for incorporating constraints such as SOC, environmental conditions, etc. into the allocation algorithm. 4) The robustness against communication failures and topology changes is insufficient. In a distributed energy system, the situation that a communication network may have packet loss, time delay and even partial nodes are out of connection exists, the existing method mostly assumes an ideal communication environment, and lacks a robust design and emergency strategy aiming at non-ideal communication conditions. Therefore, it is urgently required to design a more complete coordinated damping control method for multi-network equipment. Disclosure of Invention In order to solve the above problems in the prior art, the present invention provides a coordinated damping control method for a multi-grid device of an electric power system, including: carrying out modal identification on local power grid data acquired by networking equipment to obtain a dominant oscillation mode, and analyzing the dominant oscillation mode to obtain equivalent stiffness of the power system; determining a target virtual inertia and a target virtual damping of the power system based on the equivalent stiffness, the upper limit constraint of the frequency change rate, the frequency constraint and the capacity constraint of the networking equipment in the dominant oscillation mode; acquiring participation weights of all networking devices based on rated capacity, charge state and pre-constructed centerless communication graphs of all networking devices; The participation weight, the virtual inertia to be solved and the virtual damping to be solved of each device are taken as parameters to construct a global optimization function of each networking device, wherein the virtual inertia to be solved of each networking device is the target virtual inertia, and the virtual damping to be solved of each networking device is the target virtual damping; and carrying out iterative solution on the global optimization function by adopting a distributed original-dual iterative algorithm and a dynamic average consistency mechanism to obtain virtual inertia and virtual damping of each networking device. Optionally, the step of performing modal identification on the local power grid data collected by the networking device to obtain the dominant oscillat