Power grid transmission section dynamic capacity increasing evaluation method and system based on meteorological information

Abstract

The application provides a power grid transmission section dynamic capacity evaluation method and system based on meteorological information, and belongs to the technical field of communication. The method comprises the following steps: according to the regional power grid mode report and online operation result, extracting the transmission section transmission capacity limited data of the corresponding level power grid, wherein the transmission section transmission capacity limited data comprises regional power grid operation mode scheduling plan data, unit real-time operation data and new energy prediction data; according to the transmission section transmission capacity limited data, selecting a limited transmission section; obtaining the out-of-domain meteorological information corresponding to each limited transmission section, wherein the out-of-domain meteorological information comprises real-time environmental temperature, real-time sunshine intensity, real-time wind speed and real-time wind direction; according to the order from high to low of the limitation degree, based on the out-of-domain meteorological information, analyzing the transmission capacity improvement space of each limited transmission section and the corresponding single gear improvement value.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of communication technology, and in particular to a power grid power transmission section dynamic capacity increase evaluation method and system based on meteorological information. BACKGROUND

[0002] Dynamic capacity increase is to calculate the dynamic load flow of the line at the current time through real-time data collection without breaking the existing safety regulations, and to fully utilize the hidden capacity of the power transmission line. Dynamic capacity increase technology can bring significant economic benefits at peak load time and has good application prospects.

[0003] The transmission capacity of overhead power transmission lines is not only directly related to the structural parameters and electrical operating parameters of the conductor, but also closely related to the meteorological environmental parameters of the geographical location of the conductor. At present, due to the obvious differences in regional and seasonal differences of power grids at all levels across the country, setting the thermal stability limit of electrical equipment according to seasonal operation modes such as summer operation mode, winter operation mode and spring-autumn operation mode cannot truly reflect the transmission capacity of the power transmission line. SUMMARY

[0004] Therefore, the present application provides a power grid power transmission section dynamic capacity increase evaluation method and system based on regional meteorological information, which calculates the dynamic capacity increase improvement space of the power transmission line according to the meteorological information corresponding to the limited power transmission section of the power transmission line, and improves the transmission capacity of the power transmission line.

[0005] The technical solution adopted by the embodiments of the present application to solve the technical problems is:

[0006] A power grid power transmission section dynamic capacity increase evaluation method based on regional meteorological information, comprising:

[0007] According to the regional power grid mode report and the online operation result, the transmission capacity limited data of the power transmission section of the corresponding level power grid is extracted, and the transmission capacity limited data of the power transmission section includes regional power grid operation mode scheduling plan data, real-time operation data of the unit and new energy prediction data;

[0008] According to the transmission capacity limited data of the power transmission section, the limited power transmission section is selected;

[0009] Obtain the domain external meteorological information corresponding to each limited power transmission section, and the domain external meteorological information includes real-time environmental temperature, real-time solar radiation intensity, real-time wind speed and real-time wind direction;

[0010] According to the order from high to low of the limited degree, based on the domain external meteorological information, the transmission capacity improvement space of each limited power transmission section and the corresponding single gear improvement value are analyzed.

[0011] Preferably, the regional power grid operation mode scheduling plan data comprises device state change plan, load forecast, unit generation plan, sub-area / provincial total exchange plan, DC line plan data, and the unit real-time operation data comprises real-time topology of the network structure of the regional power grid, voltage of the regional power grid, and active power of the regional power grid.

[0012] Preferably, based on the regional grid meteorological information provided by the meteorological center, the external domain meteorological information refers to the average value of the meteorological data according to the grid area where the longitude and latitude are located, and the external domain meteorological information corresponding to each of the limited power transmission sections is obtained by:

[0013] Collecting the starting longitude and latitude coordinates and the ending longitude and latitude coordinates of the transmission line conductor or conductor cluster included in the limited power transmission section;

[0014] Calculating the span distance between the starting longitude and latitude coordinates and the ending longitude and latitude coordinates;

[0015] When the span distance is less than the distance threshold, the real-time environmental temperature, the real-time light intensity, the real-time wind speed and the real-time wind direction corresponding to the starting longitude and latitude coordinates or the ending longitude and latitude coordinates are obtained as the external domain meteorological information corresponding to the limited power transmission section; the real-time environmental temperature refers to the average value of the environmental temperature T aavg , the real-time light intensity refers to the average value of the solar radiation intensity J avg , and the real-time wind speed refers to the average value of the wind speed at a height of 70m from the ground V 70 .

[0016] When the span distance is not less than the distance threshold, the starting real-time environmental temperature, the starting real-time light intensity, the starting real-time wind speed and the starting real-time wind direction corresponding to the starting longitude and latitude coordinates are obtained, the ending real-time environmental temperature, the ending real-time light intensity, the ending real-time wind speed and the ending real-time wind direction corresponding to the ending longitude and latitude coordinates are obtained, and the external domain meteorological information corresponding to the limited power transmission section comprises the starting real-time environmental temperature, the starting real-time light intensity, the starting real-time wind speed, the starting real-time wind direction, the ending real-time environmental temperature, the ending real-time light intensity, the ending real-time wind speed and the ending real-time wind direction.

[0017] Preferably, based on the external domain meteorological information, the transmission capacity improvement space of each of the limited power transmission sections and the corresponding single gear improvement value are analyzed in the order from high to low according to the limited degree.

[0018] The active power transmission limited power of each of the limited power transmission sections under the future state plan mode is calculated in real time.

[0019] rank the limited power transmission sections in descending order of active power transmission limitation, and analyze each of the limited power transmission sections in sequence according to the ranking result;

[0020] select one of the limited power transmission sections, and collect online operation data of a conductor or conductor cluster of a power transmission line included in the limited power transmission section;

[0021] perform online calculation of transmission capacity of the conductor or conductor cluster of the power transmission line included in the limited power transmission section according to the online operation data and the out-of-domain meteorological information, to obtain an online calculation result of transmission capacity of the power transmission line;

[0022] perform static security check of the power grid according to the online calculation result of transmission capacity of the power transmission line;

[0023] determine a transmission capacity improvement space of the limited power transmission section based on the online calculation result of transmission capacity of the power transmission line, set a number of gears according to actual adjustment of regulation and control operation, and calculate the single-gear improvement value corresponding to the number of gears.

[0024] Preferably, when the crossing distance is less than a distance threshold, the online calculation of transmission capacity of the conductor or conductor cluster of the power transmission line included in the limited power transmission section according to the online operation data and the out-of-domain meteorological information to obtain the online calculation result of transmission capacity of the power transmission line comprises:

[0025] set the conductor temperature as a nominal allowable temperature T1, and calculate the current thermal stability limit I T1,i of the power transmission line conductor i in a normal operation state

[0026] I 2 R T1 +P s =P r +P f

[0027] In the formula, P s is a solar heat absorption power, P r is a radiation heat dissipation power, P f is a convection heat dissipation power, R T1 is an AC conductor resistance value at the conductor temperature T1, and I is a conductor current-carrying capacity.

[0028] In the formula, the calculation formula of the radiation heat dissipation power P r is:

[0029]

[0030] In the formula, D is a conductor diameter, and ε is a conductor radiation heat dissipation coefficient, ε ∈ [0.9, 0.95].

[0031] Wherein, the calculation formula of the heat dissipation power P f is:

[0032] P f = λE μ π(T1-T aavg )

[0033]

[0034] R e =1.644×10 9 V 70 D[T aavg +0.5(T1-T aavg )] -1.78

[0035] In the formula, E μ is Euler number, R e is Reynolds number;

[0036] Wherein, the calculation formula of the heat dissipation power P s is:

[0037] P s = αJ avg D

[0038] In the formula, α is the heat absorption coefficient of the wire surface, wherein, the value range of the new bright wire is 0.35-0.46, and the value range of the old wire or the black anticorrosive agent wire is 0.9-0.95;

[0039] Wherein, the calculation formula of the R T1 is:

[0040] R T1 = (1+k e )R d

[0041] R dT1 = R 20 [1+ α 20 (T1-20)]

[0042] In the formula, R dT1 is the DC wire resistance value when the wire temperature is T1, α 20 is the wire material temperature coefficient at 20℃, R 20 is the DC wire resistance value at 20℃, k e is the skin effect coefficient;

[0043] Wherein, the calculation formula of the wire solar radiation intensity J actual considering the error function is:

[0044] J actual =J avg ×η

[0045] wherein η is the solar radiation error coefficient of the grid area range where the transmission line conductor i is located; and the calculation formula of the conductor wind speed V speed is as follows:

[0046] V speed =a+b×β×V 70

[0047] wherein a and b are constant coefficients obtained by regression analysis according to the wind speed curve of the grid area range where the transmission line conductor i is located, and β is the uncertainty probability coefficient of the wind speed curve of the grid area range where the transmission line conductor i is located;

[0048]

[0049] The conductor temperature is set as the emergency allowable temperature T2, and the current thermal stability limit I T2,i of the transmission line conductor i in the emergency state is calculated.

[0050]

[0051] The thermal stability transmission capacity limit P T1,i of the transmission line conductor i in the normal operation state and the thermal stability transmission capacity limit P T2,i of the transmission line conductor i in the emergency state are calculated.

[0052]

[0053]

[0054] The transmission line transmission capacity online calculation result includes the thermal stability transmission capacity limit P T1,i of the transmission line conductor i in the normal operation state and the thermal stability transmission capacity limit P T2,i of the transmission line conductor i in the emergency operation state.

[0055] Preferably, according to the transmission line transmission capacity online calculation result, performing power grid static security checking includes:

[0056] constructing a simulation section according to the conductor information of the limited transmission section, the power grid control online model and the online operation data of the limited transmission section;

[0057] verifying the new transmission capacity limit P and Whether the static safety of the power grid under normal operation of the transmission line is met, and whether the equipment exceeds the limit under the N-1 fault of the whole network equipment and the expected fault set given by the power grid control operation of the simulated section, where m is the number of conductors or conductor clusters included in the restricted transmission section;

[0058] If the verification fails, auxiliary decision calculation is initiated to eliminate the limit violation until the verification result shows that the limit violation does not exist.

[0059] Preferably, the step of determining the transmission capacity improvement space of the restricted transmission section based on the online calculation results of the transmission line's transmission capacity, setting the number of gears according to the actual situation of control and operation adjustments, and calculating the single gear improvement value corresponding to the number of gears includes:

[0060] Determine the new transmission capacity limit under normal operating conditions. This provides room for improving the transmission capacity of the restricted power transmission section;

[0061] The error function f(ε) value is obtained based on the error analysis algorithm:

[0062]

[0063] Calculate the error weight W for a single gear based on the number of gears n. ε,i :

[0064] W ε,i =f(ε) / n

[0065] Calculate the transmission line from 0 to The single gear increase value ∑P afterT1,i :

[0066]

[0067] Preferably, when the crossing distance is not less than a distance threshold, the step of performing online calculations of the transmission capacity of the transmission line conductors or conductor clusters included in the restricted transmission section based on the online operating data and the external meteorological information, and obtaining the online calculation results of the transmission line transmission capacity, includes:

[0068] Based on the real-time ambient temperature, real-time light intensity, real-time wind speed, and real-time wind direction at the starting end, the thermal stability transmission capacity limit P of the transmission line conductor i under normal operating conditions is calculated. T1,i-1 and the thermal stability transmission capacity limit P of the transmission line conductor i under emergency conditions. T2,i-1 ;

[0069] Based on the real-time ambient temperature, real-time light intensity, real-time wind speed, and real-time wind direction at the terminal, the thermal stability transmission capacity limit P of the transmission line conductor i under normal operating conditions is calculated. T1,i-2 and the thermal stability transmission capacity limit P of the transmission line conductor i under emergency conditions. T2,i-2 ;

[0070] Determine the thermal stability transmission capacity limit P of the transmission line conductor i under normal operating conditions. T1,i for:

[0071] P T1,i =min[P T1,i-1 ,P T1,i-2 ]

[0072] According to P T1,i The calculation parameters, from P T2,i-1 With P T2,i-2 The thermal stability transmission capacity limit P of the transmission line conductor i under emergency operation is selected from the data. T2,i The online calculation result of the transmission capacity of the transmission line includes the thermal stability transmission capacity limit P of the transmission line conductor i under normal operating conditions. T1,i And the thermal stability transmission capacity limit P of the transmission line conductor i under emergency operation conditions T2,i .

[0073] Furthermore, the present invention also provides a dynamic capacity expansion assessment system for power grid transmission sections based on regional meteorological information, comprising:

[0074] The extraction module extracts the transmission capacity limitation data of the corresponding level of power grid based on the regional power grid mode report and online operation results. The transmission capacity limitation data includes regional power grid operation mode scheduling plan data, unit real-time operation data and new energy forecast data.

[0075] The selection module selects the restricted power transmission sections based on the data on the limited transmission capacity of the power transmission sections;

[0076] The acquisition module acquires the meteorological information outside the region corresponding to each of the restricted power transmission sections. The meteorological information outside the region includes real-time ambient temperature, real-time solar radiation intensity, real-time wind speed, and real-time wind direction.

[0077] The analysis module, based on the extraterritorial meteorological information, analyzes the potential for improving the transmission capacity of each restricted power transmission section and the corresponding improvement value for a single gear, in descending order of the degree of restriction.

[0078] As can be seen from the above technical solution, the dynamic capacity expansion assessment method and system for power grid transmission sections based on regional meteorological information provided in this embodiment of the invention can extract the transmission capacity limitation data of the corresponding level of power grid based on the regional power grid mode report and online operation results. Based on the transmission capacity limitation data, limited transmission sections are selected, and the corresponding external meteorological information for each limited transmission section is obtained. This external meteorological information includes real-time ambient temperature, real-time solar radiation intensity, real-time wind speed, and real-time wind direction. Following the order of limitation degree from high to low, the transmission capacity improvement space of each limited transmission section, as well as the corresponding single-level improvement value, are analyzed based on the external meteorological information. Through this solution, the dynamic capacity expansion space of the transmission line can be calculated based on the meteorological information corresponding to the limited transmission sections, thereby improving the transmission capacity of the transmission line. Attached Figure Description

[0079] Figure 1 This is a flowchart of a method for evaluating the dynamic capacity expansion of power grid transmission sections based on regional meteorological information.

[0080] Figure 2 This is a structural diagram of a power grid transmission section dynamic capacity expansion assessment system based on regional meteorological information. Detailed Implementation

[0081] The technical solution and effects of the present invention will be further described in detail below with reference to the accompanying drawings.

[0082] like Figure 1 As shown, the dynamic capacity expansion assessment method for power grid transmission sections based on regional meteorological information of the present invention is implemented through the following steps:

[0083] Step S1: Based on the regional power grid mode report and online operation results, extract the transmission capacity limitation data of the corresponding level of the power grid. This data includes regional power grid operation mode scheduling plan data (equipment status change plan, load forecast, unit generation plan, regional / provincial overall exchange plan, DC line plan data, etc.), real-time unit operation data (real-time topology of the regional power grid structure, voltage, and active power of transmission lines), and renewable energy forecast data. A limited transmission section refers to a theoretical transmission cross-section of a power system consisting of one or more transmission lines, where the active power that can be transmitted is the sum of the power transmitted by each transmission line.

[0084] Step S2: Select the restricted transmission sections based on the data on the limited transmission capacity of the transmission sections;

[0085] Step S3: Obtain the meteorological information outside the region corresponding to each restricted power transmission section. The meteorological information outside the region includes real-time ambient temperature, real-time solar radiation intensity, real-time wind speed, and real-time wind direction.

[0086] Step S4: Based on meteorological information from outside the region, analyze the potential for improving the transmission capacity of each restricted transmission section and the corresponding improvement value for each individual level, in order of decreasing degree of restriction.

[0087] Based on the regional grid meteorological information provided by the meteorological center, the external meteorological information refers to the average meteorological data of the grid area according to latitude and longitude. The specific operations of step S3 to obtain the external meteorological information corresponding to each restricted transmission section include:

[0088] Step S31: Collect the latitude and longitude coordinates of the starting and ending points of the transmission line conductors or conductor clusters contained in the restricted transmission section;

[0089] Step S32: Calculate the distance spanned between the latitude and longitude coordinates of the starting end and the latitude and longitude coordinates of the ending end;

[0090] Step S33: When the crossing distance is less than a distance threshold, obtain the real-time ambient temperature, real-time light intensity, real-time wind speed, and real-time wind direction corresponding to the latitude and longitude coordinates of the starting or ending points as the extraterritorial meteorological information corresponding to the restricted transmission section. The relevant meteorological information data for the transmission line conductors is obtained from regional grid meteorological information provided by the meteorological center, typically in Network Common Data Form (NetCDF) format. The grid point's longitude, latitude, time, wind speed at 70m altitude, wind direction at 70m altitude, and light intensity are extracted from NetCDF. In this embodiment, the real-time ambient temperature refers to the average ambient temperature T. aavg Real-time light intensity refers to the average value of solar radiation intensity (J). avg Real-time wind speed refers to the average wind speed V at a height of 70m above the ground. 70 Calculate the thermal stability transport capacity limit.

[0091] Step S34: When the crossing distance is not less than the distance threshold, obtain the real-time ambient temperature, real-time light intensity, real-time wind speed and real-time wind direction of the starting end corresponding to the latitude and longitude coordinates of the starting end, and obtain the real-time ambient temperature, real-time light intensity, real-time wind speed and real-time wind direction of the ending end corresponding to the latitude and longitude coordinates of the ending end. The meteorological information outside the region corresponding to the restricted transmission section includes the real-time ambient temperature, real-time light intensity, real-time wind speed and real-time wind direction of the starting end, the real-time ambient temperature, real-time light intensity, real-time wind speed and real-time wind direction of the ending end.

[0092] Step S4, following the order of confinement severity from highest to lowest, analyzes the potential for improving the transmission capacity of each confined transmission section and the corresponding improvement value for each individual level based on external meteorological information. The specific operations include:

[0093] Step S41: Calculate the active power transmission limitation power of each restricted transmission section under the future planning mode in real time; perform rolling analysis of active power transmission limitation on the section to be analyzed under the planning mode, and adjust it to a certain power flow level according to the pre-set adjustment method (i.e., increasing output or reducing load of units in the sending area, and decreasing output or increasing load of units in the receiving area), and perform safety and stability verification; if a stability problem is found, start auxiliary decision calculation to eliminate the limit violation, until the calculation results no longer show the discovery of safety and stability problems. At this time, the power flow of the section is the maximum available transmission power of the transmission section. By comparing the maximum available transmission power with the renewable energy output power under the planning mode, the active power transmission limitation power of this planning mode is determined.

[0094] Step S42: Sort the restricted transmission sections in reverse order from high to low, sort the restricted transmission sections according to the active power transmitted restricted power of each restricted transmission section, and analyze each restricted transmission section in turn according to the sorting results.

[0095] Step S43: Select a restricted transmission section and collect online operation data of the transmission line conductors or conductor clusters contained in the restricted transmission section;

[0096] Step S44: Based on online operation data and meteorological information from outside the region, calculate the transmission capacity of the transmission line conductors or conductor clusters included in the restricted transmission section online to obtain the online calculation results of the transmission line transmission capacity.

[0097] Step S45: Perform static safety verification of the power grid based on the online calculation results of the transmission line transmission capacity;

[0098] Step S46: Based on the online calculation results of the transmission capacity of the transmission line, determine the space for improving the transmission capacity of the restricted transmission section, set the number of gears according to the actual situation of the control operation, and calculate the single gear improvement value corresponding to the number of gears.

[0099] Step S44 performs online calculation of the transmission capacity of the transmission line conductors or conductor bundles included in the restricted transmission section, which calculates the thermal stability transmission capacity limit P of transmission line i under normal operating conditions. T1,i And the thermal stability transmission capacity limit P of transmission line i under emergency operation conditions. T2,i .

[0100] When the distance traveled is less than the distance threshold, the real-time ambient temperature obtained above refers to the average ambient temperature T. aavg Real-time light intensity refers to the average value of solar radiation intensity (J). avg Real-time wind speed refers to the average wind speed V at a height of 70m above the ground. 70 Calculate the thermal stability transport capability limit:

[0101] Based on online operational data and meteorological information from outside the region, the specific calculation process for online calculation of the transmission capacity of transmission line conductors or conductor clusters included in the restricted transmission section is as follows:

[0102] Set the conductor temperature to the nominal allowable temperature T1, and calculate the current thermal stability limit I of conductor i of the transmission line under normal operating conditions. T1,i :

[0103] I 2 R T1 +P s =P r +P f (1)

[0104] In the formula, P s P is the solar heat absorption power. r For radiative heat dissipation power, P f For convective heat dissipation power, R T1 Let T1 be the resistance of the AC conductor at conductor temperature T1, and I be the current carrying capacity of the conductor.

[0105] Radiative heat dissipation power P r The calculation formula is:

[0106]

[0107] In the formula, D is the diameter of the transmission line conductor, ε is the radiation heat dissipation coefficient of the conductor, and ε∈[0.9,0.95];

[0108] Convection heat dissipation power P f The calculation formula is:

[0109] P f =λE μ π(T1-T aavg (3)

[0110]

[0111] R e =1.644×10 9 V 70 D[T aavg +0.5(T1-T aavg )] -1.78 (5)

[0112] In the formula, E μ Let R be the Euler number. e It is the Reynolds number;

[0113] Sunlight heat absorption power P s The calculation formula is:

[0114] Ps =αJ avg D (6)

[0115] In the formula, α is the heat absorption coefficient of the conductor surface, where the value ranges from 0.35 to 0.46 for bright new wires and from 0.9 to 0.95 for old wires or wires coated with black anti-corrosion agent.

[0116] Among them, R T1 The calculation formula is:

[0117] R T1 =(1+k) e )R d (7)

[0118] R dT1 =R 20 [1+α 20 (T1-20)] (8)

[0119] In the formula, R dT1 α is the resistance value of a DC conductor at a conductor temperature of T1. 20 R is the temperature coefficient of the conductor material at 20℃. 20 The resistance value of a DC conductor at 20℃, kΩ e For the skin effect coefficient, select the corresponding coefficient value from the commonly used skin effect coefficient library, or adjust the setting according to the actual situation.

[0120] Considering the error function, the solar irradiance J of the conductor actual The calculation formula is:

[0121] J actual =J avg ×η (9)

[0122] In the formula, η is the solar irradiance error coefficient for the region.

[0123] Wind speed V of the conductor considering the error function speed The calculation formula is:

[0124] V speed =a + ×β × V 70 (10)

[0125] In the formula, a and b are constant coefficients obtained by regression analysis based on the wind speed curve of the grid area where the transmission line conductor i is located, and β is the uncertainty probability coefficient of the wind speed curve of the grid area where the transmission line conductor i is located.

[0126]

[0127] Set the conductor temperature to the emergency allowable temperature T2, and refer to the aforementioned formula 1-11 to calculate the current thermal stability limit I of transmission line conductor i under emergency conditions. T2,i :

[0128]

[0129] Calculate the thermal stability transmission capacity limit P of transmission line conductor i under normal operating conditions. T1,i And the thermal stability transmission capacity limit P of transmission line conductor i under emergency conditions. T2,i :

[0130]

[0131]

[0132] The online calculation results of the transmission line transmission capacity include the thermal stability transmission capacity limit P of the transmission line conductor i under normal operating conditions. T1,i And the thermal stability transmission capacity limit P of transmission line conductor i under emergency operation conditions. T2,i .

[0133] When the crossing distance is not less than the distance threshold, the thermal stability transmission capacity limit is calculated based on the extraterritorial meteorological information corresponding to the latitude and longitude coordinates of the starting end and the extraterritorial meteorological information corresponding to the latitude and longitude coordinates of the ending end, respectively. The thermal stability transmission capacity limit P of transmission line i under normal operating conditions based on the coordinates of the starting end is then obtained. T1,i-1 And the thermal stability transmission capacity limit P of transmission line conductor i under emergency conditions. T2,i-1 And the thermal stability transmission capacity limit P of transmission line i under normal operating conditions based on the end coordinates. T1,i-2 And the thermal stability transmission capacity limit P of transmission line conductor i under emergency conditions. T2,i-2 Then from P T1,i-1 With P T1,i-2 The minimum value is selected as the basis for calculating the aforementioned ∑P. T1,i The thermal stability transmission capacity limit is taken as the thermal stability transmission capacity limit P of the transmission line conductor i under emergency conditions, with the same latitude and longitude coordinates. T2,i .

[0134] Step S45, based on the online calculation results of the transmission line capacity, includes the following specific implementation steps for performing the static safety verification of the power grid:

[0135] Based on the conductor information of the restricted transmission section, the online power grid control model, and the online operation data of the restricted transmission section, a simulated section is constructed;

[0136] Verification of new transmission capacity limits for restricted transmission sections based on simulated cross sections. and Whether the static safety of the power grid is satisfied under the normal operation of the transmission line, and whether there are any over-limit situations of the equipment under the N-1 fault of the whole network equipment and the given expected fault set of the power grid control operation of the simulated section, where m is the number of conductors or conductor clusters contained in the restricted transmission section;

[0137] If the verification fails, auxiliary decision calculation will be initiated to eliminate the limit violation until the verification result shows that there is no limit violation.

[0138] Step S46 determines the transmission capacity improvement space of the restricted transmission section based on the online calculation results of the transmission line transmission capacity, sets the number of taps according to the actual situation of control and operation adjustment, and calculates the single tap improvement value corresponding to the number of taps, including:

[0139] Determine the new transmission capacity limit under normal operating conditions This provides room for improving the transmission capacity of limited power transmission sections;

[0140] The error function f(ε) value is obtained based on the error analysis algorithm:

[0141]

[0142] Calculate the error weight W for a single gear based on the number of gears n. ε,i :

[0143] W ε,i =f(ε) / n (16)

[0144] Calculate the transmission line from 0 to The single gear increase value ∑P afterT1,i :

[0145]

[0146] The above-mentioned calculation parameters, improvement potential, and single-gear improvement value ∑P afterT1,i Data such as these can be displayed visually via computer, showing the individual gear increase value ∑P in tabular or graphical form. afterT1,i The improvement effect.

[0147] Furthermore, the present invention also provides a dynamic capacity expansion assessment system for power grid transmission sections based on regional meteorological information, characterized in that it includes:

[0148] The extraction module extracts the transmission capacity limitation data of the corresponding level of power grid based on the regional power grid mode report and online operation results. The transmission capacity limitation data includes regional power grid operation mode scheduling plan data, unit real-time operation data and new energy forecast data; the specific implementation refers to the aforementioned step S1.

[0149] Select the module and choose the restricted transmission section based on the data on the limited transmission capacity of the transmission section; for specific implementation, refer to the aforementioned step S2.

[0150] The acquisition module acquires the meteorological information from outside the region corresponding to each restricted power transmission section. The meteorological information from outside the region includes real-time ambient temperature, real-time solar radiation intensity, real-time wind speed, and real-time wind direction. For specific implementation, refer to the aforementioned steps S31-S34.

[0151] The analysis module, based on meteorological information from outside the region, analyzes the potential for improving the transmission capacity of each restricted transmission section and the corresponding improvement value for each individual level, in descending order of the degree of restriction. For specific implementation, refer to steps S41-S46 above.

[0152] The system architecture can be referenced accordingly. Figure 2 As shown, this invention analyzes the transmission capacity improvement potential of key transmission lines or line clusters with thermal instability limitations by combining conductor information, regional weather, and power grid planning and operation data. It achieves panoramic perception of these limited sections using targeted regional meteorological data. While ensuring the accuracy and timeliness of information such as limited section analysis, key section tracking, and capacity expansion analysis, this invention simplifies investment in transmission line monitoring equipment and effectively taps the potential of existing power grid control equipment and internal and external data. The system proposed in this invention overcomes the limitations of traditional applications based on micro-meteorological data from transmission lines in large power grids, performing capacity expansion analysis and safety assessment from a network-wide perspective, thus improving the practicality of dynamic capacity expansion.

[0153] This invention fully considers the requirements of the control system for power grid security. It utilizes the correlation between various internal and external data, as well as the continuity between real-time and historical data, to calculate the collected data, ensuring power grid security and better aligning with the usage habits of the control system. It analyzes dynamic capacity expansion of the power grid using core modules such as the control system's scheduling plan, power flow calculation, and static security analysis, determining the necessity and feasibility of capacity expansion and providing technical support for dispatchers to manage the power grid. Furthermore, it evaluates and analyzes the dynamic capacity expansion process from both line capacity and power grid security perspectives, ensuring the safety of dynamic capacity expansion.

[0154] This invention provides a flexible and dynamic solution to the problem of limited transmission sections while adhering to conductor temperature limits and without altering the current state of the power grid. This helps to promote the absorption of new energy sources and improve the dynamic and refined management of thermal stability limits for transmission equipment. It also provides real-time and visualized information support for optimizing operation modes and improving power grid emergency strategies.

[0155] The above-disclosed embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of the invention. Those skilled in the art will understand that implementing all or part of the above-described embodiments and making equivalent changes in accordance with the claims of the present invention are still within the scope of the invention.

Claims

1. A method for dynamic capacity expansion assessment of power grid transmission sections based on regional meteorological information, characterized in that, include: Based on the regional power grid mode report and online operation results, the transmission capacity limitation data of the corresponding power grid section is extracted. The transmission capacity limitation data includes regional power grid operation mode scheduling plan data, unit real-time operation data and new energy forecast data. Based on the limited transmission capacity data of the aforementioned transmission sections, the limited transmission sections are selected; Obtain the meteorological information outside the region corresponding to each of the restricted power transmission sections, including real-time ambient temperature, real-time light intensity, real-time wind speed and real-time wind direction; Based on the meteorological information from outside the region, the transmission capacity improvement potential of each restricted power transmission section and the corresponding single-level improvement value are analyzed in descending order of the degree of restriction. Based on the regional grid meteorological information provided by the meteorological center, the extra-regional meteorological information refers to the average meteorological data of the grid area according to latitude and longitude. Obtaining the extra-regional meteorological information corresponding to each of the restricted power transmission sections includes: Collect the latitude and longitude coordinates of the starting and ending points of the transmission line conductors or conductor clusters contained in the restricted transmission section; Calculate the distance spanned between the latitude and longitude coordinates of the starting point and the latitude and longitude coordinates of the ending point; When the crossing distance is less than a distance threshold, the real-time ambient temperature, real-time light intensity, real-time wind speed, and real-time wind direction corresponding to the latitude and longitude coordinates of the starting end or the ending end are obtained as the extraterritorial meteorological information corresponding to the restricted power transmission section; the real-time ambient temperature refers to the average ambient temperature T. aavg The real-time light intensity refers to the average value of solar radiation intensity J. avg The real-time wind speed refers to the average wind speed V at a height of 70m above the ground. 70 ; When the crossing distance is not less than a distance threshold, the real-time ambient temperature, real-time light intensity, real-time wind speed, and real-time wind direction of the starting end corresponding to the latitude and longitude coordinates of the starting end are obtained, and the real-time ambient temperature, real-time light intensity, real-time wind speed, and real-time wind direction of the ending end corresponding to the latitude and longitude coordinates of the ending end are obtained. The meteorological information outside the region corresponding to the restricted power transmission section includes the real-time ambient temperature, real-time light intensity, real-time wind speed, real-time wind direction of the starting end, real-time ambient temperature, real-time light intensity, real-time wind speed, and real-time wind direction of the ending end. The analysis of the transmission capacity improvement potential of each restricted transmission section, and the corresponding single-level improvement value, based on the extra-regional meteorological information, in descending order of the degree of restriction, includes: The active power transmission limited power of each restricted transmission section under the future state planning mode is calculated in real time. The restricted transmission sections are sorted according to their active power transmission restricted power in descending order, and then analyzed according to the sorting results. Select one of the restricted transmission sections and collect online operation data of the transmission line conductors or conductor clusters contained in the restricted transmission section; Based on the online operation data and the extra-regional meteorological information, the transmission capacity of the transmission line conductors or conductor clusters included in the restricted transmission section is calculated online to obtain the online calculation results of the transmission line transmission capacity. Based on the online calculation results of the transmission capacity of the transmission lines, perform a static safety check of the power grid. Based on the online calculation results of the transmission capacity of the transmission line, the transmission capacity improvement space of the restricted transmission section is determined, the number of gears is set according to the actual situation of the control operation, and the improvement value of the single gear corresponding to the number of gears is calculated. When the crossing distance is less than a distance threshold, the online calculation of the transmission capacity of the transmission line conductors or conductor clusters included in the restricted transmission section is performed based on the online operation data and the external meteorological information, and the online calculation result of the transmission line transmission capacity includes: Set the conductor temperature to the nominal allowable temperature T1, and calculate the current thermal stability limit I of the transmission line conductor i under normal operating conditions. T1,i : ; In the formula, P s P is the solar heat absorption power. r For radiative heat dissipation power, P f For convective heat dissipation power, R T1 Let T1 be the resistance of the AC conductor at conductor temperature T1, and I be the current carrying capacity of the conductor. Wherein, the radiative heat dissipation power P r The calculation formula is: ; In the formula, D is the diameter of the conductor, ε is the radiation heat dissipation coefficient of the conductor, and ε∈[0.9,0.95]; Among them, the convective heat dissipation power P f The calculation formula is: ; ; ; In the formula, E μ Let R be the Euler number. e It is the Reynolds number; Wherein, the solar heat absorption power P s The calculation formula is: ; In the formula, α is the heat absorption coefficient of the conductor surface, where the value ranges from 0.35 to 0.46 for bright new wires and from 0.9 to 0.95 for old wires or wires coated with black anti-corrosion agent. in, The calculation formula is: ; ; In the formula, R dT1 α is the resistance value of a DC conductor at a conductor temperature of T1. 20 R is the temperature coefficient of the conductor material at 20℃. 20 The resistance value of a DC conductor at 20℃, kΩ e The skin effect coefficient; Among them, the solar irradiance J of the conductor considering the error function actual The calculation formula is: ; In the formula, η is the solar radiation error coefficient of the grid area where the transmission line conductor i is located; Wind speed V of the conductor considering the error function speed The calculation formula is: ; In the formula, a and b are constant coefficients obtained by regression analysis based on the wind speed curve of the grid area where the transmission line conductor i is located, and β is the uncertainty probability coefficient of the wind speed curve of the grid area where the transmission line conductor i is located. ; Set the conductor temperature to the emergency allowable temperature T2, and calculate the current thermal stability limit I of the transmission line conductor i under emergency conditions. T2,i : ; Calculate the thermal stability transmission capacity limit P of the transmission line conductor i under normal operating conditions. T1,i and the thermal stability transmission capacity limit P of the transmission line conductor i under emergency conditions. T2,i : ; ; The online calculation results of the transmission line's transmission capacity include the thermal stability transmission capacity limit P of the transmission line conductor i under normal operating conditions. T1,i And the thermal stability transmission capacity limit P of the transmission line conductor i under emergency operation conditions. T2,i ; When the crossing distance is not less than a distance threshold, the online calculation of the transmission capacity of the transmission line conductors or conductor clusters included in the restricted transmission section, based on the online operation data and the external meteorological information, yields the following online calculation results of the transmission line transmission capacity: Based on the real-time ambient temperature, real-time light intensity, real-time wind speed, and real-time wind direction at the starting end, the thermal stability transmission capacity limit P of the transmission line conductor i under normal operating conditions is calculated. T1,i-1 and the thermal stability transmission capacity limit P of the transmission line conductor i under emergency conditions. T2,i-1 ; Based on the real-time ambient temperature, real-time light intensity, real-time wind speed, and real-time wind direction at the terminal, the thermal stability transmission capacity limit P of the transmission line conductor i under normal operating conditions is calculated. T1,i-2 and the thermal stability transmission capacity limit P of the transmission line conductor i under emergency conditions. T2,i-2 ; Determine the thermal stability transmission capacity limit P of the transmission line conductor i under normal operating conditions. T1,i for: P T1,i =min[P T1,i-1 ,P T1,i-2 ] According to P T1,i The calculation parameters, from P T2,i-1 With P T2,i-2 The thermal stability transmission capacity limit P of the transmission line conductor i under emergency operation is selected from the data. T2,i The online calculation result of the transmission capacity of the transmission line includes the thermal stability transmission capacity limit P of the transmission line conductor i under normal operating conditions. T1,i And the thermal stability transmission capacity limit P of the transmission line conductor i under emergency operation conditions T2,i Based on the online calculation results of the transmission line capacity, the static safety verification of the power grid includes: Based on the conductor information of the restricted transmission section, the online power grid control model, and the online operation data of the restricted transmission section, a simulated section is constructed; Based on the simulated cross section, the new transmission capacity limit of the restricted transmission cross section is verified. and Whether the static safety of the power grid under normal operation of the transmission line is met, and whether the equipment exceeds the limit under the N-1 fault of the whole network equipment and the expected fault set given by the power grid control operation of the simulated section, where m is the number of conductors or conductor clusters included in the restricted transmission section; If the verification fails, the auxiliary decision calculation is initiated to eliminate the limit violation until the verification result shows that there is no limit violation situation. The process involves determining the transmission capacity improvement potential of the restricted transmission section based on the online calculation results of the transmission line's transmission capacity, setting the number of gears according to the actual situation of control and operation adjustments, and calculating the single gear improvement value corresponding to the number of gears, including: Determine the new transmission capacity limit under normal operating conditions. This provides room for improving the transmission capacity of the restricted power transmission section; The error function f(ε) value is obtained based on the error analysis algorithm: ; Calculate the error weight W for a single gear based on the number of gears n. ε,i : W ε,i =f(ε) / n; Calculate the transmission line from 0 to The single gear increase value ∑P afterT1,i : ∑P afterT1,i =W ε,i × 。 2. The method for dynamic capacity expansion assessment of power grid transmission sections based on regional meteorological information as described in claim 1, characterized in that, The regional power grid operation mode dispatch plan data includes equipment status change plan, load forecast, unit power generation plan, regional / provincial overall exchange plan, and DC line plan data. The real-time unit operation data includes the real-time topology of the regional power grid structure, regional power grid voltage, and regional power grid active power.

3. A dynamic capacity expansion assessment system for power grid transmission sections based on regional meteorological information, characterized in that, Performing the method according to any one of claims 1-2, comprising: The extraction module extracts the transmission capacity limitation data of the corresponding level of power grid based on the regional power grid mode report and online operation results. The transmission capacity limitation data includes regional power grid operation mode scheduling plan data, unit real-time operation data and new energy forecast data. The selection module selects the restricted power transmission sections based on the data on the limited transmission capacity of the power transmission sections; The acquisition module acquires the meteorological information outside the region corresponding to each of the restricted power transmission sections. The meteorological information outside the region includes real-time ambient temperature, real-time light intensity, real-time wind speed, and real-time wind direction. The analysis module, based on the extraterritorial meteorological information, analyzes the potential for improving the transmission capacity of each restricted power transmission section and the corresponding improvement value for a single gear, in descending order of the degree of restriction.

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