CN-121983985-A - Micro-grid emergency control strategy generation method and system

CN121983985ACN 121983985 ACN121983985 ACN 121983985ACN-121983985-A

Abstract

The invention discloses a method and a system for generating an emergency control strategy of a micro-grid, which belong to the technical field of micro-grid control, wherein the method comprises the steps of acquiring and sorting operation information of the micro-grid, analyzing data relevance based on a physical rule of an electric power system, adaptively adjusting an alert range according to the operation state of the micro-grid, screening deviation exceeding the alert range, further analyzing deviation types, amplitudes, duration and related physical quantity combinations to identify an instability mode of the micro-grid, finally evaluating the transient energy balance state of the micro-grid according to the identified instability mode, determining control quantity required for maintaining the stability of the system and issuing a control command, and because of the refined identification of the instability mode, the control strategy can be more targeted, the problem of mismatch of the control quantity is avoided, namely, the problem of effective oscillation is avoided, unnecessary load loss and economic cost are avoided, and the safe and reliable operation capability of the micro-grid under an emergency condition is improved.

Inventors

YANG YUEPING
ZHANG NING
KANG ZHONGQING
YANG YANG
FANG YUNHUI
YAO WEI
GAO YUNJUN
ZHU ZHONGJIE

Assignees

国网浙江省电力有限公司宁波供电公司
清华大学
国网(宁波)综合能源服务有限公司
浙江大学
国网山西省电力有限公司太原供电分公司

Dates

Publication Date: 20260505
Application Date: 20260205

Claims (10)

1. The micro-grid emergency control strategy generation method is characterized by comprising the following steps of: s1, acquiring operation information of a micro-grid, and sorting the operation information; s2, based on a physical rule of the power system, analyzing the relevance of the data in the operation information to obtain a relevance relation; based on the running state of the micro-grid, adaptively adjusting the alert range of the association relation, and screening out deviation exceeding the alert range; S3, analyzing the type, the amplitude, the duration and the related physical quantity combination of the deviation, and identifying the instability mode of the micro-grid based on an analysis result; And S4, evaluating the transient energy balance state of the micro-grid according to the recognized instability mode, determining the control quantity required for maintaining the stability of the system based on the transient energy balance state, and issuing a control instruction to execute the control quantity.
2. The micro grid emergency control strategy generation method according to claim 1, wherein: s2, adaptively adjusting the alert range of the association relationship based on the running state of the micro-grid, wherein the method comprises the following steps: acquiring environmental parameters in a micro-grid area, wherein the environmental parameters comprise air humidity, salt fog concentration, environmental temperature and day-night temperature difference change rate; calculating an expected leakage current and reactive loss amount induced by the environment according to the environmental parameters; Taking the expected leakage current and the reactive loss as correction terms, adding the correction terms into a balance equation defined by the physical rule of the power system, and correcting a preset balance reference; based on the corrected balance reference and in combination with the running state of the micro-grid, carrying out fine adjustment on the alert range of the association relation; When the deviation between the actual association relation obtained by carrying out association analysis according to the actual operation information of the micro-grid and the corrected balance reference continuously exceeds the alert range, determining that the abnormality exists, and triggering an emergency control strategy or performance degradation early warning according to the amplitude and duration of the abnormality.
3. The micro grid emergency control strategy generation method according to claim 2, wherein: s2, analyzing the type, the amplitude, the duration and the related physical quantity combination of the deviation, and identifying the instability mode of the micro-grid based on the analysis result, wherein the method comprises the following steps of: Integrating real-time operation data and environment parameters of operation information of a micro-grid into a unified event time sequence, and simultaneously receiving a load starting/stopping event mark sent by a heavy industrial facility control system and embedding the load starting/stopping event mark into the time sequence; Analyzing local bus voltage and reactive power data related to heavy industrial facilities in the event time sequence to obtain frequency components, amplitude change rate and duration of the local bus voltage and reactive power data in a short time window as local disturbance characteristics; matching the local disturbance characteristics with a pre-stored industrial load behavior mode to obtain local disturbance behaviors; tracking a propagation path and an influence range of the local disturbance behavior in the micro-grid network in an event time sequence by taking the local disturbance behavior as a starting point, analyzing response time delay and correlation of physical quantities of adjacent nodes, and geographic positions and electrical connection topology of affected nodes, and judging the spreading trend of disturbance based on an analysis result; and analyzing the local disturbance, the spreading trend, the frequency decreasing trend of the whole micro-grid and the power balance state to obtain a destabilization mode.
4. A micro-grid emergency control strategy generation method according to claim 3, wherein: the destabilization modes comprise frequency destabilization, load surge, voltage destabilization and power angle destabilization modes.
5. The micro grid emergency control strategy generation method according to claim 1, wherein: and S4, evaluating the transient energy balance state of the micro-grid according to the recognized instability mode, determining the control quantity required for maintaining the stability of the system based on the transient energy balance state, and issuing a control instruction to execute the control quantity, wherein the method comprises the following steps of: Acquiring running state information in running information of a micro-grid and detailed information of available control resources, wherein the available control resources comprise real-time charging and discharging capacity of an energy storage system, priority of a switchable load, starting time, climbing rate and fuel cost of a standby generator set; evaluating the execution costs of all possible control measures, including economic cost, contribution to system stability margin, and impact on power supply reliability; constructing a multi-objective optimization function with the aim of minimizing the total economic cost and maximizing the power supply continuity of the key load in the range of the system stability margin; and sending control instructions corresponding to the control quantity combination, and adjusting the control instructions in real time based on a real-time correction mechanism.
6. The method for generating the emergency control strategy for the micro-grid according to claim 5, wherein the method comprises the following steps: The control amount combination includes an execution amount and an execution timing of each control resource.
7. The method for generating the emergency control strategy for the micro-grid according to claim 5, wherein the method comprises the following steps: the real-time adjustment of the control instruction is performed based on a real-time correction mechanism, and the method comprises the following steps: acquiring real-time running state information of a micro-grid and real-time available information of control resources, wherein the real-time running state information comprises current, voltage, frequency, active power and reactive power data of each line, and the real-time available information of the control resources comprises the state of charge and available power of an energy storage battery; The system response after the control command is issued is evaluated in real time, and the actual response is compared with the expected response to obtain actual response deviation, wherein the actual response comprises frequency recovery speed, voltage stability and power balance state, and the expected response is an expected target response; identifying the resource availability deviation between the actual available amount of each control resource and the instruction requirement in real time; And dynamically calculating a supplementary or corrected control quantity according to the actual response deviation and the resource availability deviation and combining the current running state of the micro-grid and the residual available quantity of the control resource, and supplementing or correcting the control instruction based on the supplementary or corrected control quantity.
8. The micro grid emergency control strategy generation method according to claim 6, wherein: the system response after the control command is issued is evaluated in real time, and the actual response is compared with the expected response to obtain the actual response deviation, comprising the following steps: When acquiring real-time running state information of the micro-grid, simultaneously receiving similar physical quantity data from a plurality of sensors of different types; the method comprises the steps of performing time stamp alignment on received similar physical quantity data, and discarding data with inconsistent time stamps or performing interpolation based on time sequence characteristics; Performing consistency verification on the aligned multisource similar physical quantity data, and correcting or eliminating abnormal data according to the reliability level of the data source and the data change trend when the data are found to be inconsistent; When the physical quantity data of a single data source is missing, filling by using the same type of physical quantity data of other data sources, and smoothing by combining with the historical data characteristics; and evaluating the system response after the control command is issued according to the corrected real-time running state information, and comparing the actual response with the expected response to obtain the actual response deviation.
9. The micro grid emergency control strategy generation method according to claim 6, wherein: Identifying in real time a resource availability deviation between an actual availability of each control resource and a demand of the instruction, comprising the steps of: acquiring operation parameters of control resources in the operation information of the micro-grid, wherein the control resources comprise an energy storage battery pack, and the operation parameters comprise the charge state, the charge and discharge cycle times and the internal impedance of the battery; Calculating an expected performance degradation rate of the energy storage battery pack in the current environment according to the environment parameters and the operation parameters, wherein the expected performance degradation rate is used for representing capacity attenuation and internal resistance increase of the energy storage battery pack; Correcting an available power prediction value of the energy storage battery pack in real time according to an expected performance degradation rate, wherein the available power prediction value is used for reflecting environment-induced and accumulated performance degradation quantity; and comparing the corrected available power predicted value with the execution amount required in the control instruction to obtain the resource available deviation.
10. A micro-grid emergency control strategy generation system, which is applicable to the micro-grid emergency control strategy generation method according to any one of claims 1-9, and is characterized by comprising an information acquisition module, an association check module, a pattern recognition module and a control amount determination module; The information acquisition module is used for acquiring the operation information of the micro-grid and sorting the operation information; The association verification module is used for verifying association relations which are required to be met among the tidied operation information according to the physical laws of the electric power system, and adaptively adjusting the alert range of the association relations according to the operation state of the micro-grid so as to detect deviation exceeding the alert range in the association relations; the pattern recognition module is used for analyzing the type, the amplitude, the duration and the related physical quantity combination of the perceived deviation so as to recognize the instability pattern of the micro-grid; And the control quantity determining module is used for evaluating the transient energy balance state of the micro-grid according to the recognized instability mode so as to determine the control quantity required for maintaining the stability of the system and issuing a control instruction to execute the control quantity.

Description

Micro-grid emergency control strategy generation method and system Technical Field The invention relates to the technical field of micro-grid control, in particular to a micro-grid emergency control strategy generation method and system. Background With the continuous increase of the proportion of new energy in the power system, the operation of the micro-grid becomes increasingly complex, and higher requirements are put on the safe and stable operation of the power system. Especially in special scenes such as ports, islands and the like with extremely high requirements on power supply reliability, the micro-grid is required to ensure the stability of local power utilization and effectively cope with the inherent intermittence and fluctuation of new energy power generation. Under the background, the emergency control measures are key means for ensuring that the system does not generate large-scale power failure under the emergency condition, and the timeliness and the accuracy of the control strategy directly determine whether the micro-grid can safely and reliably run continuously. However, the existing emergency control method often depends on rules set in advance or the result of off-line simulation. When facing uncertainty and complex and changeable operation modes caused by high-proportion new energy access, the traditional method has the problems of insufficient adaptability and reduced accuracy. Specifically, after complex disturbance occurs, the traditional method is difficult to quickly and accurately identify the instability mode and risk characteristics of the system, and the control strategy is easy to cause mismatch, namely insufficient control quantity can not be used for oscillation, or unnecessary load loss and economic cost are caused by excessive control, so that optimization of control cost can not be realized while stability margin is ensured. Therefore, when the traditional method is used for coping with the variability and uncertainty caused by new energy, the traditional method is always worry, the risk of the system is difficult to accurately judge, the control effect is not ideal, and even unnecessary loss can be caused. In view of the above, there is a need in the art for improvements. Disclosure of Invention Aiming at the problem that the existing micro-grid emergency control method is difficult to adapt to control strategy mismatch caused by uncertainty and complex and changeable operation modes caused by high-proportion new energy access, the invention provides the micro-grid emergency control strategy generation method and system, which can more accurately identify system anomalies by dynamically adjusting the alert range, avoid misjudgment or missed judgment caused by preset rule rigidification in the traditional method, and simultaneously realize refined identification of a instability mode, so that the control strategy can be more specific, the problem of control quantity mismatch is avoided, namely, oscillation can be effectively subsided, unnecessary load loss and economic cost are avoided, in addition, the control quantity is determined based on the transient energy balance state, the maximization of the system stability margin is ensured under emergency conditions, and the safe and reliable operation capability of the micro-grid under emergency conditions is remarkably improved. In a first aspect, the technical scheme provided in the embodiment of the invention is that a micro-grid emergency control strategy generation method comprises the following steps: s1, acquiring operation information of a micro-grid, and sorting the operation information; s2, based on a physical rule of the power system, analyzing the relevance of the data in the operation information to obtain a relevance relation; based on the running state of the micro-grid, adaptively adjusting the alert range of the association relation, and screening out deviation exceeding the alert range; S3, analyzing the type, the amplitude, the duration and the related physical quantity combination of the deviation, and identifying the instability mode of the micro-grid based on an analysis result; And S4, evaluating the transient energy balance state of the micro-grid according to the recognized instability mode, determining the control quantity required for maintaining the stability of the system based on the transient energy balance state, and issuing a control instruction to execute the control quantity. According to the method and the device, the running state change of the micro-grid can be dynamically adapted, the instability mode can be accurately identified, and the control quantity is optimized based on the transient energy balance state, so that the problems of insufficient adaptability and reduced accuracy of a traditional method under the background of high permeability of new energy are effectively solved, and the stability and reliability of the micro-grid are improved. Preferably, in S2, the adaptive ad