CN-122026486-A - Parallel-off-grid smooth switching method for source network charge storage integrated micro-grid

CN122026486ACN 122026486 ACN122026486 ACN 122026486ACN-122026486-A

Abstract

The invention discloses a parallel-off-grid smooth switching method for a source network load-storage integrated micro-grid, which comprises the steps of hierarchical collaborative construction, dynamic adaptation adjustment, double-stage switching and switching optimization. Setting a hierarchical coordination mechanism according to a source level, an upper node level and a local level, collecting operation state data of each level to generate a level state matrix, calculating a switching mode adaptation coefficient and a threshold parameter through a risk power balance algorithm to generate a switching control instruction, executing preliminary switching and actual switching and collecting feedback data, and optimizing data collection weight, resource configuration logic and algorithm parameters based on the feedback data. According to the invention, through hierarchical coordination, dynamic decision and closed loop optimization, the problems of hierarchical coordination deficiency, static decision, unsmooth switching and the like in the traditional technology are solved, the stability, power supply continuity and fault coping capability of off-grid switching are improved, and the complex operation scene is adapted.

Inventors

LI XIAOBO
JIANG XUEDONG
YANG HUIJING
LV QINGMIN
WANG CHAOQUN
CHEN YI
WANG XIANG
LU HAILIN
WANG XIAOJING

Assignees

浙江浙达能源科技有限公司

Dates

Publication Date: 20260512
Application Date: 20260410

Claims (8)

1. The parallel-off-grid smooth switching method for the source network load storage integrated micro-grid is characterized by comprising the following steps of: a hierarchical collaboration construction step, namely setting a hierarchical collaboration mechanism according to a management and control level of the micro-grid, wherein the management and control level comprises a source level, an upper node level and a local level, acquiring running state data of each level in real time through the hierarchical collaboration mechanism, and integrating to generate a level state matrix; A dynamic adaptation adjustment step, namely calculating the hierarchical state matrix through a preset dynamic adaptation strategy to obtain a switching mode adaptation coefficient and a switching threshold parameter, and generating a switching control instruction according to the switching mode adaptation coefficient and the switching threshold parameter, wherein the switching control instruction comprises a switching mode instruction, a threshold parameter and a hierarchical collaborative correction identifier; A double-stage switching step, namely performing preliminary switching and actual switching according to the switching control instruction and the switching threshold parameter, collecting feedback correction data in the switching process, and respectively transmitting the feedback correction data back to a hierarchical coordination mechanism and dynamic adaptation adjustment; And switching and optimizing, namely adjusting the acquisition weight of the running state data of each level and the resource configuration logic of the corresponding level after the hierarchical coordination mechanism receives the feedback correction data, and optimizing and updating the calculation parameters of a preset algorithm after the dynamic adaptation strategy receives the feedback correction data.
2. The parallel-off-grid smooth switching method for the source network charge storage integrated micro-grid according to claim 1, wherein in the step of hierarchical collaborative construction, the source-level operation state data comprises power grid power supply stability information, switching device working state information and short-circuit fault early warning information; the running state data of the upper node level comprises node fault severity information, state of charge information of dedicated energy storage of the upper node level and adjustable power information; The local-level running state data comprise real-time load power information, local-level energy storage residual capacity information and core load power supply requirement identification; The hierarchical collaboration mechanism collects operation state data of each level through the distributed monitoring units, and the collected operation state data of each level is integrated into a level state matrix according to a preset format of a level identification, a data type, a numerical value and a collection time stamp.
3. The parallel-off-grid smooth switching method for a source network load storage integrated micro-grid according to claim 1, wherein the dynamic adaptation adjustment step comprises calculating a switching mode adaptation coefficient and a switching threshold parameter through a risk power balance algorithm, and specifically comprises: Extracting power supply stability information of a source level and node fault severity information of an upper node level according to the hierarchical state matrix, quantifying the power supply stability information of the source level into stability values, wherein the larger the stability values are, the stronger the power supply stability of the power supply is, quantifying the node fault severity information into severity levels, carrying out weighted calculation on the stability values and the severity levels according to preset weights to obtain off-grid adaptation coefficients, presetting corresponding adaptation thresholds, outputting a switching mode into a grid-connected mode if the adaptation coefficients are larger than the preset adaptation thresholds, outputting a switching mode into an off-grid mode if the adaptation coefficients are smaller than the preset thresholds, extracting adjustable power information of the upper node level and real-time load power information of a local level again according to the hierarchical state matrix, calculating the difference ratio of the real-time load power and the adjustable power, and determining a preparation switching trigger threshold and an actual switching execution threshold according to the difference ratio.
4. The parallel-off-grid smooth switching method for a source-network-charge-storage integrated micro-grid according to claim 1, wherein the dual-stage switching step comprises: When the preliminary switching is executed, a preliminary switching trigger threshold value in a switching control instruction is used as a starting condition, the preliminary switching is started when the micro-grid operation parameter is monitored to reach the threshold value, voltage deviation change rate data in the preliminary synchronization process and adjustment response time data of dedicated energy storage of an upper node level are synchronously collected to serve as preliminary stage feedback data, the preliminary stage feedback data are transmitted back to a hierarchical coordination mechanism according to a preset period, the hierarchical coordination mechanism receives a preset response threshold value, if the response time is larger than the preset response threshold value, an adjustable power evaluation value corresponding to the upper node level is immediately adjusted downwards, and the proportion that the adjustment amplitude and the response time exceed the threshold value is in linear positive correlation; When the actual switching is executed, the actual switching execution threshold is used as a trigger condition, the arcless switching device is triggered to execute switching action after the actual switching execution threshold is reached, load voltage fluctuation value and switching time-consuming data are collected in real time and are used as feedback data of an execution stage to be transmitted back to a dynamic adaptation strategy, after the dynamic adaptation strategy receives the load voltage fluctuation value and the switching time-consuming data, the fluctuation threshold is preset, and if the fluctuation value is larger than the preset fluctuation threshold, corresponding level marks are recorded and threshold parameters are tightened.
5. The parallel-off-grid smooth switching method for the source network load storage integrated micro-grid according to claim 2, wherein the step of hierarchical collaborative construction further comprises the steps of constructing emergency response triggered by short-circuit fault early-warning information, the hierarchical collaborative mechanism monitors the short-circuit fault early-warning information of a source level and an upper node level in real time, when the information appears in any level is monitored, the emergency response is immediately triggered, the hierarchical collaborative mechanism sends an emergency cut-off instruction to a source level switching device, an energy storage locking signal is generated at the same time, the energy storage locking signal is sent to a unit for dedicated energy storage control of the upper node level, the discharging function of the source level switching device is locked, the hierarchical collaborative mechanism sends an emergency response triggering signal to a dynamic adapting strategy, the dynamic adapting strategy stops the conventional algorithm operation and generates a switching mode instruction for emergency off-grid and local energy storage priority power supply, after the step of the double-stage switching is completed, the switching success signal is generated and returned to the hierarchical collaborative mechanism, the energy storage unlocking signal and the power supplementing instruction are generated again, the energy storage locking signal is sent to the unit for dedicated energy storage of the upper node level, and the discharging function is controlled to deliver electric energy according to the power requirements of local energy storage control.
6. The parallel-off-grid smooth switching method for the source network charge storage integrated micro-grid is characterized in that a hierarchical state matrix comprises data priority identifiers, the data priority identifiers comprise a highest priority, a medium priority and a common priority, a severity level threshold is preset, when the severity of a fault of a node level of an upper level is larger than the preset threshold, the priority of the fault severity information and the priority of the exclusive energy storage charge state information of the corresponding node level of the upper level are set to be the highest priority, when a core load power supply requirement identifier exists in the local level, the priority of the real-time load power information of the local level and the priority of the core load power supply requirement identifier are set to be the highest priority, and after a strategy receiving matrix is dynamically adapted, operation is performed based on the highest priority data priority to ensure that key data participate in a decision.
7. The parallel-off smooth switching method for a source network load-storage integrated micro-grid according to claim 3, wherein the dynamic adaptation adjustment step further comprises the steps of extracting local level real-time load power deviation according to the level state matrix, presetting a deviation threshold, extracting upper node level adjustable power information, presetting a power threshold, setting a preliminary handover trigger threshold as a loose threshold if the real-time load power deviation is smaller than the preset threshold and the adjustable power is larger than real-time load power of a preset multiple, reducing handover false trigger probability, setting the preliminary handover trigger threshold as a tightening threshold if the real-time load power deviation is larger than the preset threshold and the adjustable power is smaller than real-time load power of the preset multiple, starting the preliminary handover reservation adjustment time in advance, and determining specific values of the loose threshold and the tightening threshold based on historical operation data of the micro-grid for the past 6 months.
8. The parallel-off-grid smooth switching method for the source network load-storage integrated micro-grid according to claim 4, wherein the dual-stage switching step further comprises that feedback correction data returned by the dual-stage switching step comprises a voltage deviation change rate, an energy storage adjustment response time, a load voltage fluctuation value and switching time consumption, when the hierarchical collaboration mechanism receives the data, an average value is calculated for the energy storage adjustment response time data collected continuously for 3 times by the same upper node stage, if the average value is larger than a preset response threshold, an energy storage parameter adjustment instruction is generated and sent to a unit for dedicated energy storage control of the upper node stage, a charge-discharge current limit parameter and a response sensitivity parameter of the energy storage adjustment instruction are adjusted, after the dynamic adaptation strategy receives the data, statistics is carried out on the load voltage fluctuation value collected continuously for 5 times by the same local stage, if the fluctuation value is larger than the preset fluctuation threshold, a hierarchy identifier corresponding to the local stage is recorded, and the standby switching trigger threshold and the actual switching execution threshold are further tightened when the standby switching trigger threshold and the actual switching execution threshold corresponding to the hierarchy are calculated next time, until the fluctuation value collected continuously for 3 times is smaller than the preset fluctuation threshold, and tightening is stopped.

Description

Parallel-off-grid smooth switching method for source network charge storage integrated micro-grid Technical Field The invention relates to the field of power system regulation and control, in particular to a parallel-off-grid smooth switching method for a source-grid-load-storage integrated micro-grid. Background At present, the micro-grid parallel-off-grid switching technology mainly develops around ideas such as presynchronization matching, single energy storage support and the like, but has obvious defects in the aspects of source-grid charge storage multi-unit coordination, complex operation scene adaptation, fault emergency treatment and the like, and is specifically embodied in the following aspects: In the prior art, the micro-grid is not differentially designed according to the control level, the running state data of each level are isolated from each other, and a unified integration and linkage mechanism is lacked, so that the power balance is difficult to accurately control in the switching process, and the risk of increasing the line loss or interrupting the power supply is easy to occur; the prior art has the problems that the switching mode is mainly fixedly arranged and is not combined with the real-time running state dynamic adjustment of a micro-grid, the switching false triggering or the switching is not timely caused easily, the factors such as the energy storage charge state, the core load priority and the like are not fully considered in the decision process, the forced off-grid or non-core load occupies excessive power supply resources after the local energy storage is exhausted can occur, the traditional switching is mainly carried out by adopting single triggering type operation, namely the switching is directly carried out after a fault signal is detected, the preliminary switching stage is not arranged, the voltage mutation and the frequency oscillation are easily caused by the direct switching due to the inherent deviation between the voltage and the frequency in the grid connection state and the off-grid state, the impact is easily caused to precision electric equipment, even the equipment tripping is caused, the presynchronization is introduced in part of the technology, but the state data in the presynchronization process is not fed back to the subsequent decision, the switching parameters are not timely corrected, the random fluctuation of a distributed power supply is difficult to be adapted, the prior art has the problems that the extreme faults such as short circuit are executed, the prior art has only single operation of an emergency cut-off circuit is not constructed, the stage emergency response logic is not constructed, the upper node energy storage can still be in a discharging state after the fault is diffused, the fault is aggravated, the fault is easy to be released, the step-down, the voltage is easy to be caused, the voltage is easy to be broken, the voltage is lacked to be directly due to the energy storage mode and the energy storage mode is directly to be directly caused by the energy storage mode under the voltage-saving mode, the impact level has the energy storage mode, the factors, the impact has the energy storage and the impact factor is lacked and the factors are caused by the factors, the upper support cannot be obtained rapidly when the local energy storage electric quantity is insufficient, so that the power supply continuity of the core load is difficult to guarantee. Therefore, in order to solve the problems of hierarchical synergetic deficiency, decision staticization, insufficient switching smoothness, imperfect fault processing and no closed loop optimization in the prior art, the invention provides a parallel-off-grid smooth switching method for a source network charge storage integrated micro-grid. Disclosure of Invention Aiming at the defects existing in the prior art, the invention aims to provide a parallel-off-grid smooth switching method for a source network load storage integrated micro-grid. In order to achieve the above purpose, the present invention provides the following technical solutions: A parallel-off-grid smooth switching method for a source network charge storage integrated micro-grid comprises the following steps: a hierarchical collaboration construction step, namely setting a hierarchical collaboration mechanism according to a management and control level of the micro-grid, wherein the management and control level comprises a source level, an upper node level and a local level, acquiring running state data of each level in real time through the hierarchical collaboration mechanism, and integrating to generate a level state matrix; A dynamic adaptation adjustment step, namely calculating the hierarchical state matrix through a preset dynamic adaptation strategy to obtain a switching mode adaptation coefficient and a switching threshold parameter, and generating a switching control instruction according to the switching mode ad