CN114678866B - Power transmission line load transfer control method based on regulation and control cloud - Google Patents

Abstract

The present invention discloses a load transfer control method for power transmission lines based on a control cloud, comprising the following steps: Step 1: Reading equipment ledger data from a control cloud platform to obtain all power transmission and transformation equipment information; Step 2: Generate a tree-like power grid topology model in a single power source point mode according to equipment information and connection relationships; Step 3: Reading control cloud telemetry data and telesignaling data to form a load path; Step 4: According to the load path model, perform line load tripping risk judgment; Step 5: For lines with tripping risks, perform post-tripping load transfer analysis to quickly assess new risks caused by load transfer. The present invention uses a tree structure rather than a traditional graph structure to decompose the power grid, takes a high-voltage busbar as the root node, and performs transmission path analysis through a line load tripping risk assessment method, thereby avoiding the loopback problem brought about by the traditional method, and can provide early warning of events, with fast calculation speed and high efficiency.

Description

A load transfer control method for transmission lines based on control cloud

Technical Field

The present invention belongs to the field of electric power dispatching automation, and in particular relates to a transmission line load transfer control method based on a control cloud.

Background Art

There are two main methods for analyzing the load transfer of transmission lines caused by tripping in power transmission and transformation in the existing dispatching system:

The first method divides the entire power grid into power supply area and load area, and the line between the power supply area and the load area is set as the transmission section; after the line is overloaded, the key transmission section is searched in the transmission section where it is located by calculating the disconnection distribution factor. This type of search method is divided into two stages, pre-event and post-event, and the search speed is fast, but it is only applicable to spindle-type power grids with obvious transmission sections.

The second method regards the power grid after the line trip as the superposition of the normal power grid and the faulty power grid. It uses graph theory to search for the main power transfer path in the faulty power grid and determines the superposition effect of the fault current on the normal current on the main power transfer path to determine the key transmission section of the overloaded line. This method has good adaptability to the power grid, but it is a post-search and has a slow search speed.

Summary of the invention

The technical problem to be solved by the present invention is to provide a transmission line load transfer control method based on a control cloud, which uses a tree structure rather than a traditional graph structure to decompose the power grid, takes the high-voltage bus as the root node, and performs transmission path analysis through a line load tripping risk assessment method, thereby avoiding the loop back problem brought about by the traditional method, and can achieve event early warning, fast calculation speed and high efficiency.

In order to solve the above technical problems, the technical solution adopted by the present invention is:

A transmission line load transfer control method based on a control cloud comprises the following steps:

Step 1: Read the equipment ledger data from the control cloud platform to obtain all the power transmission and transformation equipment information;

Step 2: Generate a tree-like power grid topology model in a single power point mode according to the device information and connection relationship;

Step 3: Read the control cloud telemetry data and telesignal data to form a load path;

Step 4: According to the load path model, the risk of line load tripping is judged;

Step 5: For lines with tripping risks, perform post-tripping load transfer analysis to quickly assess new risks caused by load transfer.

Furthermore, the specific operation of step 1 is: obtain the name, plant ID, owner, and plant type of all substations with the highest voltage level less than or equal to 220 kV from the control cloud library; and obtain the equipment information in these substations, the equipment includes busbars, transformers, AC line terminals, loads, disconnectors with a current telesignal value of 1, and circuit breakers with a current telesignal value of 1.

Furthermore, the specific construction method of the tree-like power grid topology model in step 2 is:

Step 2.1: Select the busbar whose current voltage Uab value is greater than 220 kV and set it as the power supply point, set as E1, E2...En. If the busbar is connected to other 220 kV buses in the same substation, record these buses as the same power supply point;

Step 2.2: Take the 110 kV busbar of the same substation that is connected to the power source through the transformer, and record the 110 kV busbar as nodes 110-1, 110-2, 110-3.....110-m. If there is a connected 110 kV busbar, record it as the same node; obtain the 110 kV line with the circuit breaker telesignal value of 1 on the node, record the 110 kV busbar of the opposite substation connected to it according to its connection relationship and record it as another node, then continue to obtain the line on the node to search for other nodes, repeat the process until the 110 kV node is fully indexed, and record the transformer between the power source point and the 110 kV busbar as a 110 kV node;

Step 2.3: Take the 110 kV node recorded in step 2.2, and take the 35 kV bus connected to the 110 kV node through the transformer of the same substation. The 35 kV bus is recorded as nodes 35-1, 35-2, 35-3.....35-o. If there are connected 35 kV busbars, they are recorded as the same node; obtain the 35 kV line with the circuit breaker telesignal value of 1 on the node, and record the 35 kV line of the opposite substation connected to it according to its connection relationship. volt bus and record it as another node, then continue to obtain the lines on the node to search for other nodes, repeat the process until the 35 kV node is fully indexed and its superior 110 kV node is recorded, and the transformer between the 110 kV node and the 35 kV bus is recorded as a 35 kV node; if there is a 35 kV load device on the 35 kV node, then record the device as a 35 kV terminal load device, and record its superior node as a 110 kV node, which does not overlap with the 35 kV node;

Step 2.4: Take the 35 kV node recorded in step 2.3, and take the 10 kV bus connected to the 35 kV node through the transformer of the same substation, obtain the 10KV load device on the 10 kV bus, record its upper node, and record the 10 kV load device as a 10 kV terminal load device;

Step 2.5: Take the power point recorded in step 2.1, take the 110 kV node recorded in step 2.2, then take the 35 kV bus connected to the 110 kV node through the transformer of the same substation, obtain the 35 kV load on the 35 kV bus, record its upper node, and record the 35 kV load as the terminal load device; take the power point recorded in step 2.1, take the 110 kV node recorded in step 2.2, take the 35 kV node and 35 kV terminal load device recorded in step 2.3, take the 10 kV terminal load device recorded in step 2.4; record the 35 kV and 10 kV terminal load devices as load points L1, L2...Lj;

Step 2.5: According to the equipment connection relationship recorded in steps 2.1 to 2.4, a tree-like power grid topology model of the power supply point is established in a tree structure according to the voltage level from high to low, and then the tree-like power grid topology model is saved. The tree-like power grid topology model is recorded as t1, t2, t3...tn.

Preferably, step 3 is specifically:

Step 3.1: Obtain the active power, reactive power, and current of the transformer winding in the power grid topology model from the control cloud; the Uab line voltage of the bus; and the active power, reactive power, and current of the AC line segment endpoints;

Step 3.2: Taking each terminal load device as the starting point and the power source point as the end point, search the power transmission path of the tree-like power grid topology model from bottom to top for the terminal load device, and obtain the shortest path from the starting point to the end point of each terminal load device in the tree-like power grid topology model. The collection of the shortest paths of all terminal load devices, s1, s2, s3...sk, is the load path S.

Preferably, in step 3.2, the terminal load device is selected to have a current value greater than 5 amperes and an active power value greater than 0.99 megawatts.

Furthermore, for any tree-like power grid topology model tn0, the j-th load path sq in the load path s1, s2, ..., sn0, takes the rated active value Pjmax of the line connected to the load point Lj from the control cloud library. When the actual power P of the line connected to the load point Lj is greater than μPjmax, it is judged that the line is in an overloaded state and has a risk of tripping, where μ is the load rate.

Preferably, μ=0.88.

Furthermore, the specific operations of step 5 are:

Step 5.1: For any tree-like power grid topology model tn0, remove the lines with tripping risks in the load path s1, s2, ..., sn0 to form a new load path s1', s2', ..., sn1;

Step 5.2: According to the power path transfer judgment formula, obtain the tripping risk line power transfer path set sn2;

Step 5.3: The active power transferred to the power transfer path set sn2 is:

Wherein, ΔP _p1 is the load to which the jth line in the power transfer path set sn2 is transferred, the number of nodes of each path in Sn2 is o1, o2, o3, ... ow, P _now is the current active value of the line where the load is located, α is the theoretical minimum number of transmission nodes, c is the number of nodes of the power transfer path including the power source point and the load point, and z is the total number of power transfer paths with the same number of nodes as the power transfer path;

Step 5.4: Calculate the real-time power of the lines where other load points are located when power transfer occurs after the line trips:

P _tnow = P _now + ΔP _j1

Among them, P _tnow represents the real-time power of the line where other load points are located when power transfer occurs after the line trips;

Step 5.5: If Ptnow>μPjmax, then the load is used as the chain reaction point;

Step 5.6: When the chain reaction point is greater than 1, there is a chain tripping risk, and the tripping risk load point and chain reaction point are output.

Furthermore, the power path transfer judgment formula is:

Wherein, D(E _n ,L _j ) represents the number of nodes that the line with source point En and load point Lj passes through, Dj1 represents the number of nodes of other lines after the line with source point En and load point Lj trips, and r represents the power path transfer rate threshold.

Preferably, r=2.

Compared with the prior art, the invention has the following beneficial effects:

The technical problem to be solved by the present invention is to provide a transmission line load transfer control method based on a control cloud, which uses a tree structure rather than a traditional graph structure to decompose the power grid, takes the high-voltage bus as the root node, and performs transmission path analysis through a line load tripping risk assessment method, thereby avoiding the loop back problem brought about by the traditional method, and can achieve event early warning, fast calculation speed and high efficiency.

1. The present invention uses a tree structure rather than a traditional graph structure to decompose the power grid, and uses the high-voltage bus as the root node to perform transmission path analysis, thereby avoiding the loopback problem brought about by the traditional method, and also avoiding the large amount of calculation required to process the power grid topology model through matrices or other methods in the traditional solution.

2. The tree-like grid topology model designed by the present invention ignores the current influence caused by resistance and transverse waves in the regional grid, and limits the influence of power transfer to the range radiated by a single 220kV power source point. Compared with the traditional power transfer method, the traditional purely theoretical calculation method considers too many parameters but has little influence on the calculation results. Since the effects of multiple power sources with small influence but large calculation amount are eliminated, and the loop current paths that rarely appear in practical applications are ignored, a large number of floating point numbers and matrix calculations are not required, and the data processing speed of seconds can be achieved in the application, and the calculation results can be obtained in time.

3. The evaluation method of line load tripping risk designed by the present invention abandons the traditional calculation method of load and current, such as DFT algorithm, and eliminates multiple multiplication and addition calculations. Since the actual data is consistent with the algorithm, if it is made into a chart, it will show less burrs. In the calculation, a large amount of data cleaning and smoothing processing can naturally be abandoned, and a large amount of exponential operations and weighted processing of addition and subtraction can be reduced. In general, these calculations require special instruction sets in the CPU or use GPU acceleration to speed up the calculation speed, and the general computing unit in the CPU is not good at processing these, which is manifested in a slow calculation speed.

4. The shortest path method of the load path design of the present invention can overcome the problem of difficult load transfer calculation caused by the existence of multi-terminal T-connected lines and loop operation modes in the actual power grid. The traditional method is based on Kirchhoff's law and calculates according to the current and loss rate of each power grid node. The calculation amount is large and the error is large. Using this direct estimation, the effect of rapid calculation and advance warning can be achieved, and the error is no greater than that of the traditional electrical method.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a step diagram of a method for controlling load transfer of a power transmission line based on a control cloud according to the present invention;

FIG2 is a flow chart of a method for controlling load transfer of power transmission lines based on a control cloud according to the present invention;

FIG3 is a schematic diagram of a tree-like power grid topology model of the power transmission line load transfer control method based on the control cloud of the present invention.

DETAILED DESCRIPTION

The present invention will be further described below in conjunction with the accompanying drawings.

The present invention discloses a method for calculating a load transfer of a power transmission line based on a control cloud, which belongs to the technical field of power dispatching automation, and includes obtaining real-time operation data of a power grid and equipment ledger data from a control cloud dispatching automation monitoring system; establishing a topological link model of the power grid according to the acquired ledger data; analyzing the acquired real-time operation data of the power grid to obtain effective measurement data; calculating the transfer route of the line load when the line trips due to various reasons according to the topological link model and the effective measurement data, thereby avoiding the risk of large-area line tripping caused by load transfer;

Line load control is an important means to maintain the safe operation of the power grid. The system obtains integrated power data from the control cloud system, mainly including grid voltage, equipment current, equipment active power, equipment reactive power, grid equipment ledger, switch telemetering and other related information. Accurately judge the operating status of the line and the load transfer when a line tripping accident occurs, provide sufficient support for fault finding, fault analysis and fault isolation, and further improve the level of power grid management;

The control cloud dispatching automation system is an integrated model data platform built based on the needs of power grid main grid dispatching operation management, realizing the unified management and division of power grid model and comprehensive control data, so as to improve the power grid operation management level, control business and power grid operation data refinement and coordination and efficient integration. New technologies such as cloud computing are used to integrate and control the comprehensive power grid operation data from multiple systems, realize the association of business data, and establish a management system for comprehensive control data.

Specifically, as shown in FIG. 1 and FIG. 2 , a transmission line load transfer control method based on a control cloud comprises the following steps:

Step 1:

Obtain the names, plant IDs, owners, and plant types of all substations with the highest voltage level less than or equal to 220 kV from the control cloud library; and obtain the equipment information in these substations, including busbars, transformers, AC line terminals, loads, disconnectors with a current telesignal value of 1, and circuit breakers with a current telesignal value of 1.

Step 2:

For any substation with a voltage level of 220 kV (all substations with a voltage level of 220 kV obtained in step 1 are power supply points in step 2-1, and then connected in step 2-2 according to the voltage level of 220 kV->110 kV->35 kV->10 kV).

Select the bus whose current voltage Uab value is greater than 220 kV, and set it as the power supply point, set as E1, E2...En. If the bus is connected to other 220 kV busbars in the same substation, record these buses as the same power supply point.

Take the 110 kV busbar of the same substation connected to the power source point through the transformer, and record the 110 kV busbar as nodes 110-1, 110-2, 110-3...110-m. If there are connected 110 kV buses, they are recorded as the same node;

Get the 110 kV line with the circuit breaker telesignal value of 1 on the node, record the 110 kV bus of the opposite substation connected to it according to its connection relationship and record it as another node, then continue to get the line on the node to search for other nodes, repeat the process until the 110 kV node is fully indexed, and record the transformer between the power point and the 110 kV bus as a 110 kV node.

Take the 110 kV node recorded in step 2-2, and take the 35 kV bus connected to the 110 kV node through the transformer of the same substation, and record the 35 kV bus as nodes 35-1, 35-2, 35-3.....35-o. If there is a connected 35 kV bus, record it as the same node; obtain the 35 kV line on the node with a circuit breaker telesignal value of 1, record the 35 kV bus of the opposite substation connected to it according to its connection relationship and record it as another node, and then continue to obtain the line on the node to search for other nodes, repeat the process until the 35 kV node is fully indexed and its superior 110 kV node is recorded, and record the transformer between the 110 kV node and the 35 kV bus as a 35 kV node.

Take the power point recorded in step 2-1, take the 110 kV node recorded in step 2-2, then obtain and take the 35 kV bus connected to the node through a transformer in the same substation, obtain the 35 kV load on the 35 kV bus, record its upper node, and record the load as the terminal load equipment; take the power point recorded in step 2-1, take the 110 kV node recorded in step 2-2, take the 10 kV terminal load equipment recorded in step 2-3; record the 35 kV and 10 kV terminal load equipment as load points L1, L2...Lj.

According to the equipment connection relationship recorded in the above four steps, the grid topology connection model of the power supply point is established in a tree structure according to the voltage level from high to low, and then the topology connection model is saved. The topology connection model is recorded as t1, t2, t3...tn (the number of topology connection models is consistent with the number of power supply points), and at the same time, the recorded equipment will no longer appear in other grid topology connection models.

The active power, reactive power and current of the transformer winding in the power grid topology model of the power source point are obtained from the control cloud; the Uab line voltage of the bus; and the active power, reactive power and current of the AC line segment endpoints.

The power transmission path search is performed for each load device with a current value greater than 5 amperes and an active value greater than 0.99 megawatts, as follows:

Starting from this load point, search exhaustively for the shortest line s that can connect to the power point in the current model t, denoted as s1, s2, s3...sk, and the line set is denoted as S. Store the ID, power point, and load point of the equipment connected in the middle of the line into the database.

Figure 3 shows a typical tree topology connection model. The line s2 of the load point L2 is:

L2->35-2->110-2->E1; the corresponding line set in each topology model t is denoted as S.

Step 3:

After performing step 2 on all eligible 220 kV substations, take out a model tn, then select a line sj from the line set Sn of tn, and take the rated active value Pjmax of the line connected to the load point Lj from the control cloud library, the current limit and active value of each load point contained in tn (the load point is a logical abstraction of the user load in the main grid, and it corresponds to the real equipment in the distribution network. Simply put, the load point in the main grid corresponds to the overall power load of a street or a factory in reality, so the voltage level of the load point in the main grid must be 35 kV or 10 kV, and it must be at the end of the main grid, so it will not be distributed in the middle. The subtrees below E1 actually exist in 0, 1, 2, 3...n situations, which is determined by the actual connection relationship of the power grid equipment. The figure is just an illustration of a typical case).

When P>μPjmax, where μ is preferably 0.88, the line is judged to be in a heavy load state and has a tripping risk, and the load name and active power are recorded in the database. (μ is an empirical value, which means load rate in Chinese. It is generally believed that μ<0.3 is light load, 0.3<μ<0.8 is normal operation, and μ>0.8 is generally defined as heavy load. When μ>0.8 occurs, the grid dispatcher needs to try to adjust the grid operation mode to prevent tripping. When it exceeds 0.9, the risk of line tripping is extremely high. It is set to 0.88 here to be more conservative than 0.9.)

Delete line sj from Sn (in this model, the number of lines is consistent with the number of load points, which is also a naturally simplified calculation when using the tree model), and the new line set is recorded as Sn1.

After the line tripping of the load point Lj is selected from the new line set Sn1, the power transfer path set (here the path means the line) Sn2 should satisfy:

Where En represents the power source point of the line, Lj represents the load point of the line, D(E _n ,L _j ) represents the number of nodes that the line with power source point En and load point Lj passes through, Dj1 represents the number of nodes of other lines after the line with power source point En and load point Lj trips, and r is the set threshold, preferably 2.

If equation (1) is not satisfied, it means that the power path is too long, does not meet the requirements, and does not belong to Sn2.

Assume that the number of nodes of each path in Sn2 is o1, o2, o3, ..., ow, then after the line sj connected to the load point Lj trips, the active power transferred to each line in the set Sn2 is:

Wherein ΔP _j1 is the load to which each line is transferred, P _now is the current active value of the line where the load is located, α is the theoretical minimum number of transmission nodes, preferably 2, c is the number of nodes in the power transfer path including the power source point and the load point, and z is the total number of power transfer paths with the same number of nodes as the power transfer path.

After the line trips, when power transfer occurs, the real-time power of the line where other load points are located is obtained as P _tnow =P _now +ΔP _j1 .

Step 4:

Re-verify the real-time power Ptnow of each load point in Sn2 recorded in step 3.2. If Ptnow>μPj1max, where μ is preferably 0.88, then this point is used as a chain reaction point, and the load point name and corresponding Ptnow are recorded in the database.

When the chain reaction point recorded in step 4 is greater than 1, the software front-end interface displays the current chain tripping risk, and displays the tripping risk load point recorded in step 3 process ① and the chain reaction point recorded in step 4.

The present invention, through the steps performed in step 2 of the detailed technical solution, abstracts the power grid model from a "graph" of multiple power points and multiple load points that requires a large number of matrix calculations into a tree-like model of single power point and multiple loads, which can be calculated using Ohm's law and is more in line with actual operating conditions.

The present invention abandons the traditional load and current calculation method, such as DFT algorithm, and eliminates multiple multiplication and addition calculations through the calculation in step 3. Since the actual data is consistent with the algorithm, if it is made into a chart, it will show less burrs. Naturally, a large amount of data cleaning and smoothing processes can be abandoned in the calculation, and a large amount of exponential operations and weighted processing of addition and subtraction can be reduced. Generally, these calculations require special instruction sets in the CPU or use GPU acceleration to speed up the calculation speed, but the general computing unit in the CPU is not good at processing these, which is manifested in a slow calculation speed.

The innovation of the present invention is mainly that it combines computer technology to achieve a computing speed of seconds, which can solve the problem that the traditional monitoring method of setting thresholds lacks predictability and cannot assess the risks of the power grid in advance. It can also solve the problem that the traditional method has more precision but less real-time performance.

The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims (8)

1. The power transmission line load transfer control method based on the regulation cloud is characterized by comprising the following steps of:

Step 1: reading equipment account data from a regulation cloud platform, and acquiring all power transmission and transformation equipment information;

Step 2: generating a tree-shaped power grid topology model in a single power point mode according to the equipment information and the connection relation;

Step 3: reading regulation and control cloud telemetry data and remote signaling data to form a load path;

step 4: judging the tripping risk of the line load according to the load path model;

step 5: carrying out load transfer analysis after tripping on a circuit with tripping risk, and rapidly evaluating new risk caused by load transfer;

Wherein, the specific operation of the step 1 is as follows: acquiring the names, the station IDs, owners and the station types of all the substations with the highest voltage level less than or equal to 220 kilovolts from a regulation cloud base; the equipment information in the substations is acquired, wherein the equipment comprises a bus, a transformer, an alternating current line endpoint, a load, a disconnecting switch with the current remote signaling value of 1 and a breaker with the current remote signaling value of 1;

The specific construction mode of the tree-shaped power grid topology model in the step 2 is as follows:

Step 2.1: selecting a bus with a current voltage Uab value of more than 220 kilovolts, setting the bus as a power supply point, setting the bus as E1 and E2.

Step 2.2: taking 110 kilovolt buses of the same transformer substation, which are connected with a power supply point through a transformer, wherein the 110 kilovolt buses are recorded as nodes 110-1, 110-2 and 110-3. Acquiring a 110 kilovolt line with a remote signaling value of 1 of a circuit breaker on a node, recording a 110 kilovolt bus of an opposite-end transformer substation connected with the circuit breaker according to a connection relation of the circuit breaker as another node, continuously acquiring the line on the node to search for other nodes, repeating the process until the 110 kilovolt node is completely indexed, and recording that a transformer between a power supply point and the 110 kilovolt bus is the 110 kilovolt node;

Step 2.3: taking 110 kilovolt nodes recorded in the step 2.2, and taking 35 kilovolt buses connected with the 110 kilovolt nodes of the same transformer substation through a transformer, wherein the 35 kilovolt buses are recorded as nodes 35-1, 35-2 and 35-3. Acquiring a 35 kilovolt line with a remote signaling value of 1 of a circuit breaker on a node, recording a 35 kilovolt bus of an opposite-end transformer substation connected with the node according to a connection relation of the 35 kilovolt line as another node, continuously acquiring the line on the node to search for other nodes, repeating the process until the 35 kilovolt node is completely indexed and the 110 kilovolt node on the upper level is recorded, and recording that a transformer between the 110 kilovolt node and the 35 kilovolt bus is the 35 kilovolt node; if 35 kilovolt load equipment exists on the 35 kilovolt node, recording that the equipment is 35 kilovolt end load equipment, and recording that the upper node is 110 kilovolt node and is not overlapped with the 35 kilovolt node;

Step 2.4: taking the 35 KV node recorded in the step 2.3, taking a 10KV bus connected with the 35 KV node through a transformer of the same transformer substation, obtaining 10KV load equipment on the 10KV bus, recording the upper node of the 10KV load equipment, and recording that the 10KV load equipment is 10KV tail end load equipment;

Step 2.5: taking the power supply point recorded in the step 2.1, taking the 110 kilovolt node recorded in the step 2.2, then taking a 35 kilovolt bus connected with the 110 kilovolt node of the same transformer substation through a transformer, obtaining 35 kilovolt load on the 35 kilovolt bus, recording the upper node of the 35 kilovolt load, and recording the 35 kilovolt load as terminal load equipment; taking the power supply point recorded in the step 2.1, taking the 110 kilovolt node recorded in the step 2.2, taking the 35 kilovolt node and 35 kilovolt end load equipment recorded in the step 2.3, and taking the 10 kilovolt end load equipment recorded in the step 2.4; end load devices of 35 kv and 10 kv were recorded as load points L1, L2.

Step 2.5: according to the equipment connection relation recorded in the steps 2.1-2.5, a tree-shaped power grid topology model of the power supply point is built according to the voltage level from high to low in a tree-shaped structure, then the tree-shaped power grid topology model is stored, and the tree-shaped power grid topology model is recorded as t1, t2 and t3..

2. The power transmission line load transfer control method based on regulation and control cloud as set forth in claim 1, wherein step 3 specifically includes:

Step 3.1: active, reactive and current of a transformer winding in the power grid topology model are obtained from the regulation cloud; the Uab line voltage of the bus; active, reactive and current at the end points of the alternating current line segments;

Step 3.2: and searching the power transmission path of the tree-shaped power grid topological model from bottom to top by taking each end load device as a starting point and a power supply point as an ending point, and obtaining the shortest path from the starting point to the ending point of each end load device in the tree-shaped power grid topological model, wherein the aggregate S1, S2 and s3. of the shortest paths of all the end load devices is the load path S.

3. The method for controlling load transfer of a power transmission line based on regulation and control cloud according to claim 2, wherein in step 3.2, the terminal load equipment selects load equipment with a current value greater than 5 amperes and an active value greater than 0.99 megawatts.

4. The method for controlling load transfer of a power transmission line based on a regulatory cloud according to claim 3, wherein for any tree-shaped power grid topology model tn0, a j-th load path sq in load path paths s1, s2, … …, sn0 is taken from a regulatory cloud base, a rated active value Pjmax of a line connected with a load point Lj is taken, and when actual power P of the line connected with the load point Lj is greater than μ Pjmax, the line is judged to be in a heavy load state and has tripping risk, wherein μ is a load rate.

5. The method for controlling load transfer of a power transmission line based on a regulatory cloud of claim 4, wherein μ=0.88.

6. The method for controlling load transfer of a power transmission line based on a regulatory cloud of claim 5, wherein step 5 specifically operates as:

Step 5.1: for any tree-shaped power grid topology model tn0, removing a line with tripping risk from load path paths s1, s2, … … and sn0 to form new load path paths s1', s2', … … and sn1;

Step 5.2: acquiring a tripping risk line power transfer path set sn2 according to a power path transfer discrimination formula;

step 5.3: the active power to which the power transfer path set sn2 is transferred is:

Wherein Δp _p1 is the load to which the j-th line in the power transfer path set Sn2 is transferred, the node number of each path in Sn2 is o1, o2, o3., respectively, P _now is the current active value of the line where the load is located, α is the theoretical minimum transmission node number, c is the node number of the power transfer path including the power source point and the load point, and z is the total number of power transfer paths equal to the node number of the power transfer path;

Step 5.4: solving the real-time power of the circuit where other load points are located when the power transfer occurs after the circuit trips:

P_tnow＝P_now+ΔP_j1

Wherein P _tnow represents the real-time power of the line where other load points are located when the power transfer occurs after the line trips;

Step 5.5: if Ptnow > μ Pjmax, then this load acts as a chain reaction point;

step 5.6: when the chain reaction point is larger than 1, the chain tripping risk exists, and the tripping risk load point and the chain reaction point are output.

7. The method for controlling load transfer of a power transmission line based on regulatory cloud according to claim 6, wherein the power path transfer discrimination formula is:

Wherein D (E _n,L_j) represents the number of nodes through which the line with the power point of En and the load point of Lj passes, dj1 represents the number of nodes of other lines after the line with the power point of En and the load point of Lj trips, and r is the power path transfer rate threshold.

8. The method for controlling load transfer of a power transmission line based on a regulatory cloud of claim 7, wherein r=2.