A method and system for fast voltage stabilization in fault state

Abstract

The application provides a fault state transfer method and system capable of quickly stabilizing voltage, wherein the method comprises the following steps: 1) determining a fault point and a fault type; 2) constructing a graph model of transfer equipment accessibility matrix; 3) screening all transfer paths of the fault point based on the constructed graph model; 4) selecting an optimal transfer path and activating; and 5) performing dynamic fine adjustment of reactive power on the activated transfer path to complete the transfer. The application shortens the voltage recovery time to 90 seconds, controls the deviation within the rated value ± 5%, and reduces the equipment action times by 40%, and is suitable for rural high impedance, weak communication power distribution network and voltage sensitive load scene, and fills the technical blank of fault state voltage stability and rapid recovery.

Description

Technical Field

[0001] This invention belongs to the field of fault-based power transfer technology in power dispatching, and specifically relates to a method for rapid voltage stability recovery based on fault-based power transfer path reconstruction. Background Technology

[0002] Fault-based power transfer refers to the technology of quickly restoring power supply through automatic switching or load transfer when a power system fault occurs, in order to ensure the continuity and reliability of power supply. It plays a vital role in the power system, enabling automatic monitoring, diagnosis and control of the power system, and improving the operating efficiency and reliability of the power system.

[0003] Traditional fault-based power transfer methods have the following technical problems:

[0004] (1) Focusing only on the connectivity of the power transfer path without considering the voltage stability after the power transfer often leads to a sudden drop in the voltage at the receiving end (such as a voltage drop of more than 15% after long-distance power transfer in rural areas).

[0005] (2) Existing voltage control technology relies on a centralized dispatch system, which requires manual intervention after a fault and has a long recovery time (typical recovery time > 5 minutes).

[0006] (3) The lack of coordination between the power supply equipment and the voltage regulation equipment (OLTC, capacitor) results in a step-by-step control delay of "power supply first and voltage regulation later", which can easily cause secondary voltage fluctuations and affect the user experience.

[0007] (4) In the rural power distribution network scenario, when GPRS / 4G communication is used in remote areas, the one-way delay is ≥200ms and the packet loss rate is ≥5%. Traditional centralized control is prone to power transfer failure due to communication interruption.

[0008] Therefore, there is an urgent need to design a fault-state power transfer method that can respond quickly and stabilize voltage rapidly. Summary of the Invention

[0009] To address the above technical problems, this invention provides a fault-state power transfer method that can quickly restore voltage stability. It is applicable to rural high-impedance, weak communication power distribution networks and voltage-sensitive load scenarios, ensuring the stable operation of power transfer equipment and improving user experience.

[0010] The technical solution of this invention is: a fault-state power transfer method that can quickly stabilize voltage, comprising the following steps:

[0011] 1) Determine the fault location and fault type;

[0012] 2) Construct a graphical model of the accessibility matrix for the transfer equipment;

[0013] 3) Based on the constructed graph model, all transfer paths from the fault point are selected;

[0014] 4) Select the optimal transfer path and activate it;

[0015] 5) Perform dynamic reactive power fine adjustment on the activated power transfer path to complete the power transfer.

[0016] Preferably, in step 2), a graphical model is constructed using the transfer equipment as the transfer edge and the feeder segment as the node, which includes the on / off state and impedance parameters of the transfer equipment. , where V is the set of nodes and E is the set of edges to be transferred.

[0017] Preferably, when the load rate of the transfer side line is greater than the first preset load limit, the initial impedance parameter of the transfer side is increased to a preset multiple; when the load rate of the transfer side is less than or equal to the first preset load limit, the initial weighting coefficient remains unchanged.

[0018] Preferably, the method for selecting all power transfer paths from the fault point in step 3) is as follows: calculate the voltage stability margin index of the power transfer path using Thevenin equivalent parameters. ,choose The transfer path, where:

[0019] ;

[0020] In the formula: The minimum node voltage value collected within a preset time before the fault occurs;

[0021] The formula for calculating the minimum voltage of the power transfer path after power transfer is as follows:

[0022] ;

[0023] In the formula, Thevenin equivalent voltage for the transfer path. Thevenin equivalent resistance for the transfer path. Thevenin equivalent reactance for the transfer path, For the active power of the load on the transfer path, The reactive power of the load on the transfer path;

[0024] This is the rated voltage.

[0025] Preferably, step 3) further includes calculating the short-circuit capacity of the transfer path after the transfer using Thevenin equivalent calculation, and correcting... Precision, specifically:

[0026] Short-circuit capacity of the transfer path after transfer: ,

[0027] Impedance angle: ;

[0028] when At that time, if Thevenin equivalent reactance of the modified transfer path Thevenin equivalent resistance of the transfer path ;like Thevenin equivalent resistance of the corrected transfer path Thevenin equivalent reactance of the transfer path Remain unchanged; when At that time, the equivalent resistance and equivalent reactance of Thevenin in the transfer path remain unchanged;

[0029] Based on the revised and Recalculated minimum voltage for the power transfer path after recalculation:

[0030] ;

[0031] Substitution Formula updates indicator values ​​and filters The transfer path.

[0032] Preferably, in step 4), the optimal transfer path, i.e. the transfer path with the highest voltage stability margin among the transfer time ≤ preset transfer time limit, is activated by closing the target interconnection switch and simultaneously adjusting the on-load tap-changing transformer to raise the receiving end voltage to above the preset voltage target value.

[0033] Preferably, in step 5), the method for dynamic reactive power fine adjustment of the activated power transfer path is as follows:

[0034] When the positive deviation of the transfer path voltage exceeds the first preset value, the first reactor group is controlled to absorb the excess reactive power, and the reactive power output of the distributed power source is adjusted to the lower limit until the transfer path voltage falls back to the target range.

[0035] When the negative voltage deviation is lower than the first preset value, the first capacitor bank is controlled to supplement reactive power, and the reactive power output of the distributed power source is adjusted to the upper limit until the voltage of the transfer path is raised to the target range.

[0036] When the positive deviation of the supply path voltage exceeds the second preset value, the second reactor group is controlled to reduce the voltage step by step according to the first preset step size, and the phase difference is finely adjusted with the phase shifter. Each adjustment angle does not exceed the preset small angle threshold until the supply path voltage falls back to the target range.

[0037] When the negative deviation of the supply path voltage is lower than the second preset value, the second capacitor bank is controlled to gradually increase the voltage according to the second preset step size, and the phase difference is finely adjusted with the phase shifter. Each adjustment angle does not exceed the preset small angle threshold until the supply path voltage is increased to the target range.

[0038] When both the positive and negative deviations of the transfer path voltage are less than the third preset value, one set of second capacitors is retained to dynamically track voltage fluctuations.

[0039] The first preset value > the second preset value > the third preset value.

[0040] Preferably, in steps 4) and 5), the transfer path must meet the following requirements: the load rate of the transfer path is ≤ the second preset load limit value, the second preset load limit value is > the first preset load limit value, the number of times the on-load tap changer in the transfer path is adjusted is ≤ the preset adjustment number limit value, and the standard deviation of the node voltage in the transfer path area is ≤ the preset voltage standard deviation limit value.

[0041] Preferably, it also includes: an adaptive parameter adjustment mechanism: when the voltage deviation of the transfer path is greater than the fourth preset value, the number of times the tie switch in the transfer path is allowed to operate is less than or equal to the first switch operation value; when the voltage deviation of the transfer path is less than or equal to the fifth preset value, the number of times the tie switch in the transfer path is allowed to operate is less than or equal to the second switch operation value, and the first switch operation value is greater than or equal to the second switch operation value.

[0042] The fourth preset value is greater than the first preset value, and the fifth preset value is less than the third preset value.

[0043] A fault-state power transfer system that provides rapid voltage stabilization is also provided, comprising:

[0044] Fault location module: used to determine the fault location and fault type;

[0045] A graph model for constructing the reachability matrix of transfer equipment;

[0046] The path filtering module is used to filter out all transfer paths from the fault point based on the constructed graph model.

[0047] The path activation module is used to select the optimal transfer path and activate it.

[0048] The dynamic adjustment module is used to perform dynamic and fine-tuning of reactive power in the activated power transfer path to complete the power transfer.

[0049] The beneficial effects of this invention are as follows: For rural high-impedance lines, the risk of voltage drop is reduced from the source by dynamically adjusting the impedance weight and correcting the Thevenin parameter; for weak communication environments, a local graph model is used to construct and implement a hierarchical adjustment strategy to reduce reliance on real-time communication and avoid the delay and interruption problems of traditional centralized scheduling; for voltage-sensitive loads, the voltage recovery time is shortened to within 90 seconds and the deviation is controlled within ±5% of the rated value through coordinated control of "rapid activation and fine reactive power adjustment", ensuring the stable operation of the load equipment. Attached Figure Description

[0050] Figure 1 This is a flowchart of the method of the present invention. Detailed Implementation

[0051] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0052] A fault-state power transfer method that can quickly stabilize voltage, see [link to relevant documentation]. Figure 1 This includes the following steps:

[0053] 1) Determining the fault point and fault type in the power distribution system is a conventional technique, and the specific methods and principles will not be elaborated here.

[0054] 2) Construct a graphical model of the accessibility matrix for the transfer equipment;

[0055] 3) Based on the graph model constructed in step 3), filter out all available transfer paths to the fault point;

[0056] 4) Select the optimal transfer path, and the power distribution system activates that transfer path;

[0057] 5) Perform dynamic reactive power fine adjustment on the activated power transfer path to complete the power transfer.

[0058] In this embodiment, in step 2), a graphical model is constructed using the transfer equipment as the transfer edge and the feeder segment as the node, which includes the on / off state and impedance parameters of the transfer equipment. Where V is the set of nodes and E is the set of feed edges. In this embodiment, the Thevenin equivalent parameters are refreshed every 5 minutes based on real-time SCADA data.

[0059] When the load rate of the transfer side line is greater than the preset load limit, the initial impedance parameter of the transfer side is increased to a preset multiple, ranging from 1.3 to 2 times. When the load rate of the transfer side is less than or equal to the preset load limit, the initial weighting coefficient remains unchanged.

[0060] In this embodiment, when the line load rate is >80%, the impedance weighting coefficient of that side is increased by 1.5 times to avoid overload power transfer; when the line load rate of the power transfer side is ≤80%, the initial weighting coefficient remains unchanged. Through this dynamic weight adjustment, the priority of high-load lines being selected as power transfer paths can be reduced, prioritizing lines with a load rate ≤80%, thereby preventing the line load rate from exceeding the 90% safety threshold after power transfer and preventing overload power transfer. Those skilled in the art can also set other preset load limits, with the line load rate ranging from 75% to 85%.

[0061] Step 3) involves filtering all power transfer paths from the fault point: calculating the voltage stability margin index of the power transfer path using Thevenin equivalent parameters. ,choose The transfer path, where:

[0062] In this embodiment, the voltage stability margin index of the power transfer path is calculated using Thevenin equivalent parameters. ,choose The transfer path is:

[0063] ;

[0064] In the formula: The minimum node voltage value collected within 30 minutes before the fault occurred is used. In this embodiment, the minimum node voltage value collected by SCADA within 10 minutes before the fault occurred is used.

[0065] The formula for predicting the minimum voltage of the power transfer path is as follows:

[0066] ;

[0067] In the formula, Thevenin equivalent voltage for the transfer path. Thevenin equivalent resistance for the transfer path. Thevenin equivalent reactance for the transfer path, For the active power of the load on the transfer path, The reactive power of the load on the transfer path;

[0068] This is the rated voltage.

[0069] It also includes calculating the short-circuit capacity of the transfer path after the transfer using Thevenin equivalent calculation, and correcting... Precision, specifically:

[0070] Short-circuit capacity of the transfer path after transfer: ,

[0071] Impedance angle: ;

[0072] when At that time, if Thevenin equivalent reactance of the modified transfer path To enhance the calculation accuracy of inductive voltage drop, the Thevenin equivalent resistance of the supply path is transferred. To compensate for the impact of active power loss; if For resistive or weakly inductive circuits, such as cable lines, the Thevenin equivalent resistance of the transfer path should be corrected. Highlighting the impact of active power loss on voltage, the Thevenin equivalent reactance of the power transfer path. Remain unchanged; when At that time, the Thevenin equivalent resistance and equivalent reactance of the transfer path remain unchanged, indicating that the system capacity is sufficient and the voltage loss calculation error is acceptable.

[0073] Based on the revised and Recalculated minimum voltage for the power transfer path after recalculation:

[0074] ;

[0075] Substitution Formula updates indicator values ​​and filters The transfer path.

[0076] In step 4), the optimal transfer path, i.e. the transfer path with the highest voltage stability margin among the transfer time ≤ preset transfer time limit, is activated by closing the target interconnection switch and simultaneously adjusting the on-load tap changer (OLTC) to raise the receiving end voltage to above the voltage target value.

[0077] In this embodiment, in step 4), the optimal transfer path is the line with the highest voltage stability margin among those with a transfer time ≤ 600ms. (In practice, a path with a reachable distance of 3 hops or less is generally searched. One hop is defined as passing through one tie switch or sectionalizing switch. Paths with a reachable distance of 3 hops or less ensure a transfer time ≤ 600ms.) The target tie switch is closed to activate it, and the on-load tap changer (OLTC) is adjusted synchronously to raise the receiving end voltage to more than 85% of the rated value.

[0078] In step 5), the method for dynamic reactive power fine-tuning of the activated power transfer path is as follows:

[0079] When the positive deviation of the transfer path voltage exceeds the first preset value, the first reactor group is controlled to absorb the excess reactive power, and the reactive power output of the distributed power source is adjusted to the lower limit until the transfer path voltage falls back to the target range.

[0080] When the negative voltage deviation is lower than the first preset value, the first capacitor bank is controlled to supplement reactive power, and the reactive power output of the distributed power source is adjusted to the upper limit until the voltage of the transfer path is raised to the target range.

[0081] When the positive deviation of the supply path voltage exceeds the second preset value, the second reactor group is controlled to reduce the voltage step by step according to the first preset step size, and the phase difference is finely adjusted with the phase shifter. Each adjustment angle does not exceed the preset small angle threshold until the supply path voltage falls back to the target range.

[0082] When the negative deviation of the supply path voltage is lower than the second preset value, the second capacitor bank is controlled to gradually increase the voltage according to the second preset step size, and the phase difference is finely adjusted with the phase shifter. Each adjustment angle does not exceed the preset small angle threshold until the supply path voltage is increased to the target range.

[0083] When both the positive and negative deviations of the transfer path voltage are less than the third preset value, one set of second capacitors is retained to dynamically track voltage fluctuations.

[0084] The first preset value > the second preset value > the third preset value.

[0085] In this embodiment,

[0086] When the positive voltage deviation exceeds 8% of the rated value, the first reactor group is controlled to absorb excess reactive power, and the reactive power output of the distributed power source is adjusted to the lower limit. The capacity range of the first reactor group is 20%-30% of the rated reactive power capacity of the system. When the negative voltage deviation is below 8% of the rated value, the first capacitor group is controlled to supplement reactive power, and the reactive power output of the distributed power source is adjusted to the upper limit. The capacity range of the first capacitor group is 20%-30% of the rated reactive power capacity of the system.

[0087] When the positive voltage deviation is 5%-8% above the rated value, the second reactor group is controlled to step-down the voltage, and the phase difference is finely adjusted with the phase shifter. Each adjustment angle does not exceed the preset small angle threshold to balance the active power transmission and help the voltage fall back to the target range. The capacity range of the first reactor group is 5%-15% of the rated reactive power capacity of the system, and the preset small angle threshold is 0.5°-1.5°. The specific value is determined based on the impedance parameters of the power transfer path and the active power transmission efficiency model, and each adjustment angle does not exceed the threshold to avoid sudden changes in active power transmission.

[0088] When the negative voltage deviation is 5%-8% below the rated value, the second capacitor bank is controlled to gradually increase the voltage, and the phase difference is finely adjusted with the phase shifter. Each adjustment angle does not exceed the preset small angle threshold. The active power loss is adjusted to increase the voltage to the target range. The capacity range of the second capacitor bank is 5%-15% of the rated reactive power capacity of the system.

[0089] When the voltage deviation is within the target range, it shall not exceed 5% of the rated value, and one set of second capacitors shall be retained to dynamically track voltage fluctuations.

[0090] The threshold for the voltage deviation range is determined based on the withstand characteristics of voltage-sensitive loads and the voltage stability standards of the distribution network. This is a conventional technique, and the specific calculation process will not be elaborated here.

[0091] The rated reactive power capacity of the system is determined based on the maximum load power and power factor of the power transfer path. This is a conventional technique, and the specific calculation process will not be elaborated here.

[0092] In steps 4) and 5), the transfer path must meet the following requirements: the load rate of the transfer path is ≤ the second preset load limit value, the second preset load limit value is > the first preset load limit value, the number of times the on-load tap changer in the transfer path is adjusted is ≤ the preset adjustment number limit value, and the standard deviation of the node voltage in the transfer path area is ≤ the preset voltage standard deviation limit value.

[0093] In this embodiment, the power transfer path in steps 4) and 5) must meet the following requirements: load rate ≤ 90%, OLTC adjustment times ≤ 3 times / minute, and node voltage standard deviation within the power transfer path area ≤ 4%.

[0094] In this embodiment, in step 5), if only distributed power supply is available in the power transfer circuit, the reactive power output of the distributed power supply is adjusted to 1.2 times the upper limit to enhance the voltage support capability.

[0095] It also includes: an adaptive parameter adjustment mechanism: when the voltage deviation of the transfer path is greater than the fourth preset value, the number of times the tie switch in the transfer path is allowed to operate is less than or equal to the first switch operation value; when the voltage deviation of the transfer path is less than or equal to the fifth preset value, the number of times the tie switch in the transfer path is allowed to operate is less than or equal to the second switch operation value, and the first switch operation value is greater than or equal to the second switch operation value.

[0096] The fourth preset value is greater than the first preset value, and the fifth preset value is less than the third preset value.

[0097] In this embodiment, the adaptive parameter adjustment mechanism is as follows: When the voltage deviation of the power transfer path is >10%, a fast mode is activated, with the allowed number of tripping switches in the power transfer path ≤10 times / hour. When the voltage deviation of the power transfer path is ≤3%, an energy-saving mode is switched to, with the allowed number of tripping switches in the power transfer path ≤3 times / hour, and reactive power compensation is prioritized. When the voltage deviation of the power transfer path is ≤3%, the equipment operation loss ratio is <5%, so the energy-saving mode is activated; when the voltage deviation of the power transfer path is >10%, the load loss cost caused by the voltage exceeding the limit exceeds the equipment loss cost, so rapid recovery is prioritized, reducing the equipment operation frequency by 40% and extending the lifespan by 30% compared to traditional solutions.

[0098] A fault-state power transfer system that provides rapid voltage stabilization is also provided, comprising:

[0099] Fault location module: used to determine the fault location and fault type;

[0100] A graph model for constructing the reachability matrix of transfer equipment;

[0101] The path filtering module is used to filter out all transfer paths from the fault point based on the constructed graph model.

[0102] The path activation module is used to select the optimal transfer path and activate it.

[0103] The dynamic adjustment module is used to perform dynamic and fine-tuning of reactive power in the activated power transfer path to complete the power transfer.

[0104] This invention is applicable to rural high-impedance, weak communication distribution networks and voltage-sensitive load scenarios, specifically:

[0105] Voltage stability control for high-impedance rural lines: Addressing the issues of high impedance and sudden voltage drops in rural lines, step 2 prioritizes low-impedance paths by dynamically adjusting impedance weights (increasing by 1.5 times when the load rate is >80%). Step 3 calculates the voltage stability margin index (Kstab) based on Thevenin equivalent parameters to ensure that the voltage drop risk after the selected path is switched to another line is controllable. Step 5 dynamically offsets line impedance losses through graded reactive power regulation (first / second equipment in conjunction with phase shifters), avoiding the problem of voltage deviation exceeding 15% after traditional switching.

[0106] Localized decision-making adaptation for weak communication environments: To address the issues of high latency (≥200ms) and high packet loss rate (≥5%) in rural GPRS / 4G communication, the graph model construction, path selection, and activation in steps 2-4 are all completed through local terminals (such as FTUs), without relying on centralized scheduling commands; the dynamic reactive power adjustment in step 5 is based on the local voltage deviation threshold response, reducing the need for data interaction and ensuring that control strategies can still be executed quickly under weak communication conditions, avoiding the failure of power transfer caused by communication interruption in traditional solutions.

[0107] Collaborative protection mechanism for voltage-sensitive loads: Addressing the sensitivity of loads such as tea factories and livestock farms to voltage fluctuations, steps 4-5 employ a "power transfer activation and voltage regulation coordination" mode: During activation, the OLTC is simultaneously adjusted to raise the receiving-end voltage to above 85%, and then voltage deviation is rapidly converged (≤90 seconds) through graded reactive power compensation. This replaces the traditional step-by-step mode of "power transfer first, then voltage regulation," avoiding the impact of secondary fluctuations on sensitive equipment (such as aerators and temperature control systems).

[0108] Example

[0109] Taking a rural 10kV feeder system as an example, when a complete power outage occurs at substation A, three feeders lose power. The receiving end load includes voltage-sensitive aeration equipment in a fish and shrimp pond (which shuts down when the voltage drops below 90% of its rated value). Traditional power transfer solutions often cause equipment downtime and economic losses due to long restoration times (>3 minutes) and large voltage fluctuations. This invention addresses this scenario by achieving rapid and stable voltage restoration, meeting the equipment's operational requirements.

[0110] (a) Fault detection and transfer potential assessment:

[0111] 1) Determine the fault location and type through the power distribution system;

[0112] The power distribution automation system detected that the A outgoing switch of the substation tripped, and determined the fault type to be a complete substation outage.

[0113] 2) Construct a graphical model of the accessibility matrix for the transfer equipment;

[0114] Using the tie switch and feeder segment as edges and nodes, a directed graph G=(V,E) containing real-time impedance parameters is established, and Thevenin equivalent parameters are automatically refreshed (refresh cycle 5 minutes, calculation error ≤1.5%).

[0115] 3) Based on the constructed graph model, all transfer paths from the fault point are selected;

[0116] Path filtering: Search for paths reachable within 3 hops, and filter out 2 available paths:

[0117] Path 1: Connector switch S1, voltage stability margin Kstab=0.25 (threshold θ=0.2);

[0118] Path 2: Connector switch S2, Kstab=0.20.

[0119] 4) Select the optimal transfer path and activate it;

[0120] Switch action: Prioritize closing the tie switch S1 with the highest Kstab value, with a closing time of 150ms (≤200ms).

[0121] Collaborative voltage regulation: Synchronously triggers OLTC rapid voltage regulation, from level 0 to +2 (single adjustment time 10s, total time 20s), constraints: transfer line load rate ≤90%, OLTC adjustment times ≤3 times / minute;

[0122] Voltage effect: After 30 seconds, the receiving end voltage increased from 75% of the rated value to 88%, exceeding the target value of 85%, and the oxygenation equipment resumed operation.

[0123] 5) Based on the activated power transfer path, perform dynamic reactive power fine adjustment to complete the power transfer.

[0124] Deviation-level control: If a voltage deviation of 8% is detected, control one group of 500kVar capacitors; adjust the reactive power output of distributed photovoltaic power generation to +80kVar.

[0125] Control objectives: The voltage stabilizes at 95% of the rated value within 90 seconds, and the standard deviation of the regional node voltage is 3.2%, meeting the GB14711-2013 standard.

[0126] (III) Communication Fault Tolerance and Local Decision Making

[0127] Communication interruption handling: When the master station communication is interrupted, the edge controller enables the pre-stored transfer path priority table (sorted by historical Kstab) and automatically executes the first stage of control (closing S1 and adjusting OLTC).

[0128] Data synchronization: After communication is restored, local control data will be synchronized to the main station system to ensure that the control process is traceable.

[0129] (iv) Extreme scenario response (no external power supply)

[0130] Island mode activation: Triggers distributed power generation island operation, adjusting photovoltaic reactive power output to +100kVar (i.e., 1.2 times the upper limit of photovoltaic reactive power output).

[0131] Energy storage synergy: In conjunction with a 100kWh energy storage device, maintain critical load voltage ≥90% of rated value to ensure continuous equipment operation.

[0132] This invention is not limited to the above embodiments. Based on the technical solutions disclosed in this invention, those skilled in the art can make some substitutions and modifications to some of the technical features without creative effort, and all such substitutions and modifications are within the protection scope of this invention.

Claims

1. A fault-state power transfer method that can quickly stabilize voltage, characterized in that, Includes the following steps: 1) Determine the fault location and fault type; 2) Construct a graphical model of the accessibility matrix for the transfer equipment; 3) Based on the constructed graph model, all transfer paths from the fault point are selected; 4) Select the optimal transfer path and activate it; 5) Perform dynamic reactive power fine-tuning on the activated power transfer path to complete the power transfer; In step 5), the method for dynamic reactive power fine-tuning of the activated power transfer path is as follows: When the positive deviation of the transfer path voltage exceeds the first preset value, the first reactor group is controlled to absorb the excess reactive power, and the reactive power output of the distributed power source is adjusted to the lower limit until the transfer path voltage falls back to the target range. When the negative voltage deviation is lower than the first preset value, the first capacitor bank is controlled to supplement reactive power, and the reactive power output of the distributed power source is adjusted to the upper limit until the voltage of the transfer path is raised to the target range. When the positive deviation of the supply path voltage exceeds the second preset value, the second reactor group is controlled to reduce the voltage step by step according to the first preset step size, and the phase difference is finely adjusted with the phase shifter. Each adjustment angle does not exceed the preset small angle threshold until the supply path voltage falls back to the target range. When the negative deviation of the supply path voltage is lower than the second preset value, the second capacitor bank is controlled to gradually increase the voltage according to the second preset step size, and the phase difference is finely adjusted with the phase shifter. Each adjustment angle does not exceed the preset small angle threshold until the supply path voltage is increased to the target range. When both the positive and negative deviations of the transfer path voltage are less than the third preset value, one set of second capacitors is retained to dynamically track voltage fluctuations. The first preset value > the second preset value > the third preset value.

2. The fault-state power transfer method for rapidly stabilizing voltage according to claim 1, characterized in that, In step 2), a graphical model is constructed using the transfer equipment as the transfer edge and the feeder segment as the node, which includes the on / off state and impedance parameters of the transfer equipment. , where V is the set of nodes and E is the set of edges to be transferred.

3. The fault-state power transfer method for rapidly stabilizing voltage according to claim 2, characterized in that, When the load rate of the transfer side line is greater than the first preset load limit, the initial impedance parameter of the transfer side is increased to a preset multiple. When the load rate of the transfer side is less than or equal to the first preset load limit, the initial weighting coefficient remains unchanged.

4. The fault-state power transfer method for rapidly stabilizing voltage according to claim 1, characterized in that, Step 3) involves filtering all power transfer paths from the fault point: calculating the voltage stability margin index of the power transfer path using Thevenin equivalent parameters. ,choose The transfer path, where: ； In the formula: The minimum node voltage value collected within a preset time before the fault occurs; The formula for calculating the minimum voltage of the power transfer path after power transfer is as follows: ； In the formula, Thevenin equivalent voltage for the transfer path. Thevenin equivalent resistance for the transfer path. Thevenin equivalent reactance for the transfer path, For the active power of the load on the transfer path, The reactive power of the load on the transfer path; This is the rated voltage.

5. A fault-state power transfer method for rapidly stabilizing voltage according to claim 4, characterized in that, Step 3) also includes calculating the short-circuit capacity of the transfer path after the transfer using Thevenin equivalent calculation, and correcting... Precision, specifically: Short-circuit capacity of the transfer path after transfer: , Impedance angle: ; when At that time, if Thevenin equivalent reactance of the modified transfer path Thevenin equivalent resistance of the transfer path ;like Thevenin equivalent resistance of the corrected transfer path Thevenin equivalent reactance of the transfer path Remain unchanged; when At that time, the equivalent resistance and equivalent reactance of Thevenin in the transfer path remain unchanged; Based on the revised and Recalculated minimum voltage for the power transfer path after recalculation: ； Substitution Formula updates indicator values ​​and filters The transfer path.

6. The fault-state power transfer method for rapidly stabilizing voltage according to claim 1, characterized in that, In step 4), the optimal transfer path, i.e. the transfer path with the highest voltage stability margin among the transfer time ≤ preset transfer time limit, is activated by closing the target interconnection switch and simultaneously adjusting the on-load tap-changing transformer to raise the receiving end voltage to above the preset voltage target value.

7. A fault-state power transfer method for rapidly stabilizing voltage according to claim 3, characterized in that, In steps 4) and 5), the transfer path must meet the following requirements: the load rate of the transfer path is ≤ the second preset load limit value, the second preset load limit value is > the first preset load limit value, the number of times the on-load tap changer in the transfer path is adjusted is ≤ the preset adjustment number limit value, and the standard deviation of the node voltage in the transfer path area is ≤ the preset voltage standard deviation limit value.

8. A fault-state power transfer method for rapidly stabilizing voltage according to claim 1, characterized in that, it further... include: Adaptive parameter adjustment mechanism: When the voltage deviation of the transfer path is greater than the fourth preset value, the number of times the tie switch in the transfer path is allowed to operate is less than or equal to the first switch operation value; when the voltage deviation of the transfer path is less than or equal to the fifth preset value, the number of times the tie switch in the transfer path is allowed to operate is less than or equal to the second switch operation value, and the first switch operation value is greater than the second switch operation value. The fourth preset value is greater than the first preset value, and the fifth preset value is less than the third preset value.

9. A fault-state power transfer system that rapidly stabilizes voltage, characterized in that, include: Fault location module: used to determine the fault location and fault type; A graph model for constructing the reachability matrix of transfer equipment; The path filtering module is used to filter out all transfer paths from the fault point based on the constructed graph model. The path activation module is used to select the optimal transfer path and activate it. The dynamic adjustment module is used to perform dynamic and fine-tuning of the active power transfer path to complete the power transfer. Methods for dynamic reactive power fine-tuning of activated power transfer paths: When the positive deviation of the transfer path voltage exceeds the first preset value, the first reactor group is controlled to absorb the excess reactive power, and the reactive power output of the distributed power source is adjusted to the lower limit until the transfer path voltage falls back to the target range. When the negative voltage deviation is lower than the first preset value, the first capacitor bank is controlled to supplement reactive power, and the reactive power output of the distributed power source is adjusted to the upper limit until the voltage of the transfer path is raised to the target range. When the positive deviation of the supply path voltage exceeds the second preset value, the second reactor group is controlled to reduce the voltage step by step according to the first preset step size, and the phase difference is finely adjusted with the phase shifter. Each adjustment angle does not exceed the preset small angle threshold until the supply path voltage falls back to the target range. When the negative deviation of the supply path voltage is lower than the second preset value, the second capacitor bank is controlled to gradually increase the voltage according to the second preset step size, and the phase difference is finely adjusted with the phase shifter. Each adjustment angle does not exceed the preset small angle threshold until the supply path voltage is increased to the target range. When both the positive and negative deviations of the transfer path voltage are less than the third preset value, one set of second capacitors is retained to dynamically track voltage fluctuations. The first preset value > the second preset value > the third preset value.

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