Limit transmission power determination method and device of power transmission line, terminal equipment and storage medium

Abstract

The invention discloses a limit transmission power determination method and device for a power transmission line, terminal equipment and a storage medium, and the method comprises the steps: constructing a system stability model for describing the stability characteristics of a power system according to the frequency data of each load point in the power transmission line and each operation index in the power system; the limit transmission power is determined by repeatedly executing the critical value evaluation operation, and the current frequency value and the operation index value of each load point and the power system can be obtained in each evaluation, so that the method can adapt to the real-time change of the operation state of the power system; and substituting the real-time monitored frequency and the operation index value into the system stability model for solving so as to continuously evaluate the stability performance of the power system, and adjusting the generator according to the evaluation result to obtain the limit transmission power. According to the method, the finally obtained limit transmission power can accurately reflect the stable operation characteristic of the power system, and the instability or overload phenomenon of the system is avoided.

Description

Technical Field

[0001] The present invention relates to the field of operation and processing technology of power transmission lines, and in particular to a method, device, terminal equipment and storage medium for determining the limit transmission power of a power transmission line. Background Art

[0002] The transmission power limit of a transmission line is one of the key factors to ensure the stable operation of a power system. It determines the maximum power that can be safely transmitted by a transmission line without causing system instability. Accurate transmission power limit is crucial for the planning, design and operation management of a power system. It can help operators to reasonably arrange power generation and transmission plans, avoid overload and instability, and thus ensure the safe and stable operation of the power system.

[0003] In traditional technology, determining the limit transmission power of a transmission line usually relies on empirical formulas or static analysis. For example, a fixed power threshold or experience-based power limit is used to determine the limit transmission power of a transmission line. This lacks flexibility and accuracy. Not only is it unable to adapt to real-time changes in the operating state of the power system, but it is also unable to determine the limit transmission power of the transmission line by evaluating the stability performance of the power system. The traditional method of determining the limit transmission power may not be able to accurately determine the limit transmission power that reflects the stable operation of the power system, resulting in system instability or overload. Summary of the invention

[0004] The embodiments of the present invention provide a method, apparatus, terminal device and storage medium for determining the limit transmission power of a transmission line, which can substitute the real-time monitored frequency and operating index values ​​into the system stability model for solution, thereby ensuring that the obtained limit transmission power can still enable the power system to maintain stable operation by continuously evaluating the stability performance of the power system. This can effectively solve the problem in the prior art that it is impossible to obtain a limit transmission power that accurately reflects the stable operation of the power system, resulting in system instability or overload.

[0005] An embodiment of the present invention provides a method for determining a transmission power limit of a power transmission line, comprising:

[0006] Based on the frequency data of each load point in the transmission line and various operating indicators in the power system, a system stability model is constructed to describe the stability characteristics of the power system;

[0007] Repeat the following critical value evaluation operation until it is determined that the critical value is not less than the preset critical threshold value, and the difference between the critical value and the preset critical threshold value is not greater than the preset difference threshold value, and the current moment corresponding to the critical value being not less than the preset critical threshold value and the difference between the critical value and the preset critical threshold value being not greater than the preset difference threshold value is taken as the target moment, and then the power corresponding to the transmission line at the target moment is taken as the limit transmission power of the transmission line:

[0008] Obtain the current frequency value of each load point at the current moment, and the current operating index values ​​of the power system at the current moment;

[0009] After substituting each current frequency value and each current operation index value into the system stability model, solving the system stability model, and when the function value of the system stability model is minimum, taking the minimum function value as the critical value;

[0010] When it is determined that the critical value is less than a preset critical threshold, the power of each generator in the transmission line is reduced; otherwise, it is determined whether the difference between the critical value and the preset critical threshold is greater than a preset difference threshold, and when it is determined that the difference is greater than the preset difference threshold, the power of each generator in the transmission line is increased;

[0011] Update the current time and perform the next critical value evaluation operation.

[0012] Preferably, the operation index of the power system includes: the angular velocity of the generator, the rotor angle between the generator and the reference generator, the steady-state rotor angle value used to characterize the rotor angle between the generator and the reference generator when the power system is in a stable operation state, the susceptance of each branch in the transmission network of the power system, the internal potential corresponding to the generator, the internal potential corresponding to the load point and the angular velocity of the preset reference generator;

[0013] Frequency data corresponding to each load point, including: frequency coefficient, frequency, and steady-state frequency value used to characterize the frequency of the load point when the power system is in a stable operating state;

[0014] The system stability model for describing the stability characteristics of the power system is constructed according to the frequency data of each load point in the transmission line and each operation index in the power system, including:

[0015] Generate a first function for characterizing the operation characteristics of the generator according to the frequency coefficient corresponding to each load point, the susceptance of each branch in the transmission network of the power system, the internal potential of the generator, the internal potential corresponding to the load point, the rotor angle difference between any two different generators, the steady-state rotor angle difference between any two different generators, and the angular velocity of a preset reference generator;

[0016] Generate a second function for characterizing the operating characteristics of the load point according to the frequency coefficient corresponding to each load point, the susceptance of each branch in the transmission network of the power system, the internal potential of the generator, the internal potential corresponding to the load point, the frequency difference between any two different load points, the steady-state frequency difference between any two different load points, and the angular velocity of a preset reference generator;

[0017] generating a target state vector for representing the operating state of the power system according to the deviation between the rotor angle of each generator and the steady-state rotor angle value, the deviation between the frequency of each load point and the steady-state frequency value, and the angular velocity of each generator;

[0018] A third functional formula for describing the operation dynamics of the power system in a state space is generated according to the first functional formula, the second functional formula, the target state vector, a preset system connection matrix for representing the network structure of the power system, and a trigonometric function for generating nonlinear terms; wherein the third functional formula includes: a nonlinear feedback term for describing the nonlinear dynamic behavior of the power system, and a linear term for describing the nonlinear dynamic behavior of the power system;

[0019] According to a preset functional formula for describing the stability of a nonlinear dynamic system and the third functional formula, generating an analytical expression of the preset functional formula;

[0020] The analytical expression of the preset functional formula is used as a system stability model for describing the stability characteristics of the power system.

[0021] Preferably, generating a target state vector for characterizing the operating state of the power system according to the deviation between the rotor angle of each generator and the steady-state rotor angle value, the deviation between the frequency of each load point and the steady-state frequency value, and the angular velocity of each generator comprises:

[0022] For each generator, a first state vector is generated according to a deviation between a rotor angle and a steady-state rotor angle value;

[0023] generating a second state vector according to the angular velocity of each generator;

[0024] For each load point, a third state vector is generated according to the deviation between the frequency and the steady-state frequency value;

[0025] The first state vector, the second state vector and the third state vector are aggregated to generate a target state vector for representing the operating state of the power system.

[0026] Preferably, the third functional formula includes:

[0027]

[0028] Where x is the target state vector, A is the matrix corresponding to the linear term, and B is the matrix corresponding to the nonlinear feedback term; φ(Cx) is the linear term corresponding to the converted target state vector after the target state vector is converted based on the trigonometric function; when i is the i-th generator, then δ ij is the rotor angle difference between any two different generators in the branch, is the steady-state rotor angle difference between any two different generators in the branch; when i is the i-th load point, then δ ij is the frequency difference between any two different load points, is the steady-state frequency difference between any two different load points; E is the preset system connection matrix, δ 1n is the rotor angle between the generator and the reference generator, is the steady-state rotor angle value used to characterize the rotor angle between the generator and the reference generator when the power system is in a stable operating state, δ (n+m)n is the frequency corresponding to the load point, is the steady-state frequency value corresponding to the load point, which is used to characterize the frequency of the load point when the power system is in a stable operating state, and ε is the branch set in the transmission network of the power system.

[0029] Preferably, generating an analytical expression of the preset functional formula according to the preset functional formula for describing the stability of the nonlinear dynamic system and the third functional formula comprises:

[0030] Generate a fourth functional formula including a target state vector and reflecting the stability of the power system according to a preset functional formula for describing the stability of the nonlinear power system and the third functional formula;

[0031] Substituting the third functional expression into the derivative corresponding to the fourth functional expression to generate a linear matrix inequality corresponding to the third function;

[0032] The linear matrix inequality is solved to generate an analytical expression of the preset functional formula.

[0033] Preferably, the constraint conditions of the system stability model include: a nonlinear constraint for characterizing the nonlinear relationship between the operating index and the stability of the power system and a nonconvex constraint for characterizing that the transient stability domain of the system stability model has nonconvexity;

[0034] The solving of the system stability model and taking the minimum function value as a critical value when the function value of the system stability model is minimum includes:

[0035] Under nonlinear constraints and non-convex constraints, the system stability model is iteratively solved until the function value of the system stability model is minimum, and the minimum function value is used as the critical value.

[0036] Preferably, the step of using the power corresponding to the transmission line at the target time as the limit transmission power of the transmission line includes:

[0037] The sum of the output powers of all the generators connected to the head end node of the transmission line is taken as the limit transmission power of the transmission line.

[0038] Based on the above method embodiments, the present invention provides corresponding device embodiments.

[0039] An embodiment of the present invention provides a device for determining a transmission power limit of a power transmission line, comprising: a model building module and a transmission power limit determining module;

[0040] The model building module is used to build a system stability model for describing the stability characteristics of the power system based on the frequency data of each load point in the transmission line and various operating indicators in the power system;

[0041] The limit transmission power determination module is used to repeatedly perform the following critical value evaluation operation until it is determined that the critical value is not less than the preset critical threshold value, and the difference between the critical value and the preset critical threshold value is not greater than the preset difference threshold value, and the current moment corresponding to the critical value being not less than the preset critical threshold value and the difference between the critical value and the preset critical threshold value being not greater than the preset difference threshold value is used as the target moment, and then the power corresponding to the transmission line at the target moment is used as the limit transmission power of the transmission line:

[0042] Obtain the current frequency value of each load point at the current moment, and the current operating index values ​​of the power system at the current moment;

[0043] After substituting each current frequency value and each current operation index value into the system stability model, solving the system stability model, and when the function value of the system stability model is minimum, taking the minimum function value as the critical value;

[0044] When it is determined that the critical value is less than a preset critical threshold, the power of each generator in the transmission line is reduced; otherwise, it is determined whether the difference between the critical value and the preset critical threshold is greater than a preset difference threshold, and when it is determined that the difference is greater than the preset difference threshold, the power of each generator in the transmission line is increased;

[0045] Update the current time and perform the next critical value evaluation operation.

[0046] Based on the above method embodiments, the present invention provides corresponding terminal device embodiments.

[0047] Another embodiment of the present invention provides a terminal device, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, and when the processor executes the computer program, it implements the method for determining the limit transmission power of a transmission line described in the above-mentioned embodiment of the invention.

[0048] Based on the above method embodiments, the present invention provides corresponding storage medium item embodiments.

[0049] Another embodiment of the present invention provides a storage medium, wherein the computer-readable storage medium includes a stored computer program, wherein when the computer program is running, the device where the computer-readable storage medium is located is controlled to execute a method for determining the limit transmission power of a transmission line as described in the above-mentioned embodiment of the invention.

[0050] The following beneficial effects are achieved by implementing the present invention:

[0051] The embodiment of the present invention provides a method, device, terminal device and storage medium for determining the limit transmission power of a transmission line. First, according to the frequency data of each load point in the transmission line and different operating indicators in the power system, a system stability model for describing the stability characteristics of the power system is constructed. Then, the present invention determines the limit transmission power by repeatedly performing the critical value evaluation operation, and in each evaluation, the current frequency value and operating indicator value of each load point and the power system are obtained, and these values ​​are substituted into the system stability model for solution. When the function value of the system stability model is the smallest, the function value at this time is used as the critical value, and then according to the comparison result between the critical value and the preset critical threshold, the power of each generator in the transmission line is adjusted, and the current time is updated for the next evaluation. This process will continue until it is determined that the difference between the critical value and the preset critical threshold is not greater than the preset difference threshold. At this time, the power corresponding to the transmission line is the limit transmission power of the transmission line. Compared with the prior art, the present invention can adapt to the real-time changes in the operating status of the power system by monitoring the frequency and operating index values ​​of the power system in real time, and substitute the real-time monitored frequency and operating index values ​​into the system stability model for solution, so as to continuously evaluate the stability performance of the power system, adjust the power of the generator according to the evaluation results, and ensure that the obtained limit transmission power can still enable the power system to maintain stable operation, so that the final obtained limit transmission power can accurately reflect the stability operation characteristics of the power system, avoid the occurrence of system instability or overload, and ensure the safe and stable operation of the power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 It is a flow chart of a method for determining the limit transmission power of a transmission line provided by an embodiment of the present invention.

[0053] Figure 2 It is a structural schematic diagram of a power system including n synchronous generators and m frequency loads provided by an embodiment of the present invention.

[0054] Figure 3 is a flow chart of a method for determining a transmission power limit provided by another embodiment of the present invention.

[0055] Figure 4 The power adjustment before and after projection to δ provided by an embodiment of the present invention 21 -δ 31 Schematic diagram of the stability region estimation results of the plane.

[0056] Figure 5 The power adjustment before and after projection to δ provided by an embodiment of the present invention 21 -δ 41 Schematic diagram of the stability region estimation results of the plane.

[0057] Figure 6 It is a structural schematic diagram of a device for determining the limit transmission power of a transmission line provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0058] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0059] like Figure 1 FIG. 1 is a flow chart of a method for determining a transmission power limit of a power transmission line provided by an embodiment of the present invention. The method for determining a transmission power limit of a power transmission line comprises:

[0060] Step S1: constructing a system stability model for describing the stability characteristics of the power system according to the frequency data of each load point in the transmission line and various operating indicators in the power system;

[0061] Step S2: Repeat the following critical value evaluation operation until it is determined that the critical value is not less than the preset critical threshold value, and the difference between the critical value and the preset critical threshold value is not greater than the preset difference threshold value, and the current moment corresponding to the critical value being not less than the preset critical threshold value and the difference between the critical value and the preset critical threshold value being not greater than the preset difference threshold value is taken as the target moment, and then the power corresponding to the transmission line at the target moment is taken as the limit transmission power of the transmission line:

[0062] Obtain the current frequency value of each load point at the current moment, and the current operating index values ​​of the power system at the current moment;

[0063] After substituting each current frequency value and each current operation index value into the system stability model, solving the system stability model, and when the function value of the system stability model is minimum, taking the minimum function value as the critical value;

[0064] When it is determined that the critical value is less than a preset critical threshold, the power of each generator in the transmission line is reduced; otherwise, it is determined whether the difference between the critical value and the preset critical threshold is greater than a preset difference threshold, and when it is determined that the difference is greater than the preset difference threshold, the power of each generator in the transmission line is increased;

[0065] Update the current time and perform the next critical value evaluation operation.

[0066] For step S1, the present invention can analyze the stability of the power system according to the frequency data of each load point in the transmission line and the different operating indicators in the power system, so as to construct a system stability model. The system stability model can comprehensively consider the frequency data of various operating indicators and load points, so as to more accurately reflect the actual operating state of the power system, and can more accurately predict the stability of the power system according to the current frequency value of the load point and the current operating indicator values ​​of each load point, and determine the limit transmission power of the transmission line accordingly.

[0067] In a preferred embodiment, the operation index of the power system includes: the angular velocity of the generator, the rotor angle between the generator and the reference generator, the steady-state rotor angle value used to characterize the rotor angle between the generator and the reference generator when the power system is in a stable operation state, the susceptance of each branch in the transmission network of the power system, the internal potential corresponding to the generator, the internal potential corresponding to the load point, and the angular velocity of the preset reference generator;

[0068] Frequency data corresponding to each load point, including: frequency coefficient, frequency, and steady-state frequency value used to characterize the frequency of the load point when the power system is in a stable operating state;

[0069] Based on the above parameters and data, a system stability model is constructed to describe the stability characteristics of the power system, including:

[0070] Generate a first function for characterizing the operation characteristics of the generator according to the frequency coefficient corresponding to each load point, the susceptance of each branch in the transmission network of the power system, the internal potential of the generator, the internal potential corresponding to the load point, the rotor angle difference between any two different generators, the steady-state rotor angle difference between any two different generators, and the angular velocity of a preset reference generator;

[0071] Generate a second function for characterizing the operating characteristics of the load point according to the frequency coefficient corresponding to each load point, the susceptance of each branch in the transmission network of the power system, the internal potential of the generator, the internal potential corresponding to the load point, the frequency difference between any two different load points, the steady-state frequency difference between any two different load points, and the angular velocity of a preset reference generator;

[0072] generating a target state vector for representing the operating state of the power system according to the deviation between the rotor angle of each generator and the steady-state rotor angle value, the deviation between the frequency of each load point and the steady-state frequency value, and the angular velocity of each generator;

[0073] A third functional formula for describing the operation dynamics of the power system in a state space is generated according to the first functional formula, the second functional formula, the target state vector, a preset system connection matrix for representing the network structure of the power system, and a trigonometric function for generating nonlinear terms; wherein the third functional formula includes: a nonlinear feedback term for describing the nonlinear dynamic behavior of the power system, and a linear term for describing the nonlinear dynamic behavior of the power system;

[0074] According to a preset functional formula for describing the stability of a nonlinear dynamic system and the third functional formula, generating an analytical expression of the preset functional formula;

[0075] The analytical expression of the preset functional formula is used as a system stability model for describing the stability characteristics of the power system.

[0076] It can be understood that the present invention can construct a mathematical model for measuring the stability characteristics of the power system based on key indicators reflecting the operating status of the power system and the load point characteristics, so as to accurately reflect the actual operating status of the power system and provide a scientific basis for the subsequent determination of the maximum transmission power of the transmission line.

[0077] In a preferred embodiment, generating a target state vector for characterizing the operating state of the power system according to the deviation between the rotor angle of each generator and the steady-state rotor angle value, the deviation between the frequency of each load point and the steady-state frequency value, and the angular velocity of each generator includes:

[0078] For each generator, a first state vector is generated according to a deviation between a rotor angle and a steady-state rotor angle value;

[0079] generating a second state vector according to the angular velocity of each generator;

[0080] For each load point, a third state vector is generated according to the deviation between the frequency and the steady-state frequency value;

[0081] The first state vector, the second state vector and the third state vector are aggregated to generate a target state vector for representing the operating state of the power system.

[0082] Schematically, the target state vector can fully and accurately reflect the current operating state of the power system by aggregating the first state vector (generator rotor angular deviation), the second state vector (generator angular velocity) and the third state vector (load point frequency deviation).

[0083] The target state vector serves as a key input of the system stability model, making stability analysis more intuitive and convenient. After generating a third function for describing the operating dynamics of the power system in the state space based on the first function, the second function, the target state vector, the preset system connection matrix for representing the network structure of the power system, and the trigonometric function for generating nonlinear terms, when solving and analyzing the third function, it is possible to determine whether the power system tends to be stable or has potential unstable factors by analyzing the changes in the state vector.

[0084] In a preferred embodiment, the third functional formula includes:

[0085]

[0086] Where x is the target state vector, A is the matrix corresponding to the linear term, and B is the matrix corresponding to the nonlinear feedback term; φ(Cx) is the linear term corresponding to the converted target state vector after the target state vector is converted based on the trigonometric function; when i is the i-th generator, then δ ij is the rotor angle difference between any two different generators in the branch, is the steady-state rotor angle difference between any two different generators in the branch; when i is the i-th load point, then δ ij is the frequency difference between any two different load points, is the steady-state frequency difference between any two different load points; E is the preset system connection matrix, δ 1n is the rotor angle between the generator and the reference generator, is the steady-state rotor angle value used to characterize the rotor angle between the generator and the reference generator when the power system is in a stable operating state, δ (n+m)n is the frequency corresponding to the load point, is the steady-state frequency value corresponding to the load point, which is used to characterize the frequency of the load point when the power system is in a stable operating state, and ε is the branch set in the transmission network of the power system.

[0087] Indicative, such as Figure 2As shown, this embodiment provides a structure diagram of a power system including n synchronous generators, the source side includes n synchronous generators, numbered from 1 to n; the load side includes m frequency loads, numbered from 2n+1 to 2n+m; the grid side includes n nodes. Figure 2 The structure diagram of the power system shown in the figure constructs a system stability model including n synchronous generators and m frequency loads. The number of generations can be eliminated by network contraction, and the equilibrium manifold can be eliminated by taking the relative angle as the state variable, thereby reducing the number of nodes and branches that need to be considered in the model, thereby reducing the dimension of the model. By taking the relative angle (such as the rotor angle difference between the generators) as the state variable, the equilibrium manifold can be eliminated, that is, the constraint condition that the system remains unchanged under certain conditions, making the system stability model of the embodiment of the present invention more concise while retaining the key information of the dynamic behavior of the system.

[0088] Furthermore, the generator of the present invention is a synchronous generator, and the reference machine is the nth synchronous generator. The frequency load of each load point is a function of the angular frequency. Then, the function model of the power system with the relative angle as the state variable after the network contraction can be expressed as:

[0089]

[0090] Among them, S ij =E i E j B ij , δ in represents the angle of synchronous generator i, or frequency load i, relative to the reference machine, ω i represents the rotor angular velocity of synchronous generator i, ω n is the rotor angular velocity of the reference machine; E i represents the internal potential of synchronous generator i with frequency load i, E i Keep constant, M i , D i denote the inertia constant and damping coefficient of synchronous generator i, respectively, and B ij represents the susceptance of branch {i,j} in the contraction network, {i,j}∈ε, ε is the set of all branches in the contraction network; d i , P di They represent the constant frequency coefficient of frequency load i, the power consumed by frequency load i in steady state, and d i >0.

[0091] Furthermore, the present invention can express the functional model of the above-mentioned power system in the form of a Lure type system, and then:

[0092] Define the state vector x = [x1; x2; x3], which consists of the vector consisting of the deviation of the angle of the synchronous generator from its steady-state value Angular velocity vector of synchronous generator The vector of the deviation of the frequency load angle from its steady-state value Define the matrix E as the graph of the contraction network, then we have

[0093] Using vectors constructed from trigonometric functions If represents the nonlinear term, the linear term and the nonlinear term of the function model of the power system can be separated, and the function model of the power system can be expressed in the state space as follows:

[0094]

[0095] Where: T1 = [I (n-1)×(n-1) ,-e1] is the coefficient matrix, is a column vector with n-1 dimensions whose elements are all 1, and I is the unit matrix; T2 = [O m×(n-1) ,-e2] is the coefficient matrix, is an m-dimensional column vector whose elements are all 1, O is a zero matrix; M = diag(M1,…,M n ) is a diagonal matrix consisting of the inertia constants of all synchronous generators, M n is the inertia constant of the synchronous generator n; D = diag (D1, ..., D n ) is a diagonal matrix consisting of the damping coefficients of all synchronous generators, D n is the damping coefficient of the synchronous generator n; S1=[M -1 ,O n×m ] is the coefficient matrix of the inverse matrix corresponding to the inertia constant matrix of the synchronous generator; S2 = [O m×n ,d -1 ] is the coefficient matrix of the inverse matrix corresponding to the constant frequency coefficient matrix, d = diag (d1, ..., d m ) is a diagonal matrix consisting of constant frequency coefficients of all frequency loads, d m is the constant frequency coefficient of the frequency load m; S = diag (S ij ) {i,j}∈ε is a diagonal matrix, S ij =E i E i B ij , E i represents the internal potential of synchronous generator i / frequency load i, E i Keep constant, B ij represents the susceptance of branch {i, j} in the contraction network, and ε is the set of all branches in the contraction network.

[0096] The function model of the power system in the state space can be expressed as a Lure type system as shown below, and the third function formula for describing the operation dynamics of the power system in the state space can be generated:

[0097]

[0098] In the formula: matrices A and B are:

[0099]

[0100]

[0101] Where: |ε| represents the number of branches.

[0102] Then the embodiment of the present invention uses the relative angle as the state variable to express the function model of the power system, including the angle, angular velocity and frequency load angle of the synchronous generator and the deviation of its steady-state value. And the function model of the power system can be expressed in the form of a Lure type system, and the state vector x is defined, including the angle, angular velocity and frequency load angle of the synchronous generator, etc. The vector composed of trigonometric functions represents the nonlinear term, and the linear term and the nonlinear term are separated, so as to better handle the complex dynamic behavior of the power system.

[0103] On the basis of the Lure-type system representation, the third functional formula is further sorted out, including the definition and specific form of matrices A and B, which can accurately describe the operating dynamics of the power system in the state space, so as to analyze and predict the stability and dynamic response of the power system.

[0104] Furthermore, after obtaining the third functional formula, an analytical expression of the preset functional formula can be generated according to the preset functional formula used to describe the stability of the nonlinear dynamic system and the third functional formula, specifically:

[0105] Generate a fourth functional formula including a target state vector and reflecting the stability of the power system according to a preset functional formula for describing the stability of the nonlinear power system and the third functional formula;

[0106] Substituting the third functional expression into the derivative corresponding to the fourth functional expression to generate a linear matrix inequality corresponding to the third function;

[0107] The linear matrix inequality is solved to generate an analytical expression of the preset functional formula.

[0108] In schematic form, first, a fourth functional formula containing a target state vector and capable of reflecting the stability of the power system can be generated based on a preset functional formula used to describe the stability of a nonlinear power system and a third functional formula. Then, by constructing the fourth functional formula, the stability of the power system under different operating conditions can be analyzed, such as analyzing the stability of the power system under different power of the generator, thereby obtaining the limit transmission power of the transmission line. Furthermore, by substituting the third functional formula into the derivative corresponding to the fourth functional formula, the dynamic model of the power system can be combined with the stability analysis function to obtain a derivative expression for the power system state. Then, based on this derivative expression, a linear matrix inequality is generated.

[0109] In a preferred embodiment, the preset function may be a Lyapunov function, and the Lyapunov function is a quadratic Lyapunov function. Q is a positive definite matrix, and the linear matrix inequality to be solved is:

[0110]

[0111] Let K1=kI |ε|×|ε| , K2=I |ε|×|ε| , then the above formula can be further transformed into:

[0112]

[0113] Using Schur's theorem, it can be further transformed into the following linear matrix inequality, that is, the linear matrix inequality corresponding to the third function is:

[0114]

[0115] Where:

[0116] By solving the linear matrix inequality, we can obtain the positive definite matrix Q and the Lyapunov function The analytical expression of the preset functional formula can be generated.

[0117] The present invention can obtain an analytical expression for the stability of the power system, and the analytical expression can be used to evaluate the stability of the power system. By utilizing the conversion process of linear matrix inequality, the embodiment of the present invention converts the complex nonlinear power system stability problem into a solvable linear problem. The generated analytical expression can be used as a system stability model for describing the stability characteristics of the power system, thereby analyzing the stability of the power system under different operating conditions, ensuring that the obtained limit transmission power can still enable the power system to maintain stable operation, so that the final limit transmission power can accurately reflect the stable operation characteristics of the power system.

[0118] For step S2, in a preferred embodiment, the present invention continuously adjusts and evaluates the operating state of the power system until a power level that meets the stability requirements is found, that is, the transmission line can maintain stable operation without exceeding this power level, and then the maximum transmission power of the transmission line can be determined.

[0119] The present invention can gradually approach the limit transmission power of the transmission line by gradually adjusting the power of the generator and re-evaluating the stability of the system. Since the impact of slight changes in the operating state of the power system on the stability can be taken into account, the ultimate limit transmission power can accurately reflect the stable operating characteristics of the power system.

[0120] Each time a critical value evaluation operation is performed, the present invention can obtain the current frequency value of each load point at the current moment and the current operating index values ​​of the power system at the current moment after reducing the power of each generator in the transmission line or increasing the power of each generator in the transmission line, thereby substituting each current frequency value and each current operating index value into the system stability model to solve the model, and obtaining the target moment corresponding to when the difference is not greater than the preset difference threshold, so as to determine the maximum transmission power of the transmission line.

[0121] In a preferred embodiment, the constraint conditions of the system stability model include: a nonlinear constraint for characterizing the nonlinear relationship between the operating index and the stability of the power system and a nonconvex constraint for characterizing that the transient stability domain of the system stability model has nonconvexity;

[0122] The solving of the system stability model and taking the minimum function value as a critical value when the function value of the system stability model is minimum includes:

[0123] Under nonlinear constraints and non-convex constraints, the system stability model is iteratively solved until the function value of the system stability model is minimum, and the minimum function value is used as the critical value.

[0124] In schematic form, since the relationship between many key variables of the power system is often nonlinear and the stability domain of the system is non-convex, the embodiments of the present invention can more truly reflect the actual operating characteristics of the power system by considering nonlinear constraints and non-convex constraints, and through iterative solution, it can gradually approach the actual operating state of the system, thereby obtaining a more accurate critical value.

[0125] In a preferred embodiment, the present invention can estimate the critical value corresponding to the Lyapunov function (ie, the analytical expression of the preset functional formula) based on the transient stability criterion, and the set consisting of the Lyapunov function and the obtained critical value is the estimated stability domain.

[0126] The transient stability criterion is:

[0127]

[0128] Among them, the polyhedron The definition is polyhedron The inflow boundary Outflow Boundary Take a branch {i,j} as an example, and satisfy and Inflow Boundary Satisfy at the same time and Outflow Boundary but

[0129] Therefore, the critical value V min The calculation of can be transformed into the following two optimization problems:

[0130]

[0131]

[0132] Indicative, and They are nonlinear constraints and non-convex constraints respectively.

[0133] It is understandable that the Lyapunov function is a preset function for evaluating the stability of a system, and the change of its value over time can reflect the stability state of the system. In the embodiment of the present invention, the minimum value of the Lyapunov function (i.e., the critical value V min ) to define the stability region of the system.

[0134] The transient stability criterion provides conditions for evaluating the stability of the system, such as the boundary conditions of the polyhedron, including the inflow boundary and the outflow boundary. The critical value V can be obtained based on the inflow boundary and the outflow boundary in the transient stability criterion. min .

[0135] Schematically, the optimization problem 1 can be: minimizing the Lyapunov function under nonlinear constraints, aiming to find the minimum value of the Lyapunov function that satisfies the nonlinear stability condition.

[0136] Optimization problem 2 can be: Under the non-convex constraint, the Lyapunov function is also minimized, taking into account the non-convexity of the system's stable domain, and finding the minimum value of the Lyapunov function that satisfies the non-convex stability condition.

[0137] For optimization problem 1, due to the existence of nonlinear constraints, the present invention can use an optimization algorithm that can handle nonlinear problems, such as the gradient descent method or the interior point method. For optimization problem 2, due to the non-convexity of the stable domain, the present invention can use an algorithm that can handle non-convex optimization problems, such as a global optimization algorithm (such as the branch and bound method, Monte Carlo simulation, etc.), aiming to find the global optimal solution, or use a local optimization algorithm combined with a multi-starting point search strategy to increase the possibility of finding the global optimal solution.

[0138] After the solution is completed, according to the critical value V min And the corresponding Lyapunov function value, we can construct an estimated stability domain. This stability domain represents the parameter range in which the system can maintain stable operation under given conditions. Then, the solution function under nonlinear constraints and non-convex constraints can be:

[0139]

[0140] Then the estimation of the stability region is:

[0141] In a preferred embodiment, the step of using the power corresponding to the transmission line at the target time as the limit transmission power of the transmission line includes:

[0142] The sum of the output powers of all the generators connected to the head end node of the transmission line is taken as the limit transmission power of the transmission line.

[0143] Indicatively, when the critical value is obtained, the difference between the critical value and the preset critical threshold is not greater than the preset difference threshold, which can be expressed as: V min -V thre ≤V e , V thre is the preset critical threshold, V e is a sufficiently small positive number.

[0144] It can be understood that the determination process of the present invention is: if the estimated critical value is less than the critical value threshold, the output power of the generator is reduced, and the critical value evaluation operation is repeatedly performed until the estimated critical value is slightly greater than the critical value threshold; if the estimated critical value is much greater than the critical value threshold, the output power of the generator is increased, and the following critical value evaluation operation is repeatedly performed;

[0145] Until the estimated critical value is slightly larger than the critical value threshold (i.e., the difference between the critical value and the preset critical threshold is not greater than the preset difference threshold), the sum of the output powers of all generators connected to the head end node of the target line at this time is recorded, which is the limit transmission power of the target line.

[0146] In a preferred embodiment, Figure 3As shown in the flowchart, the steps of the method for calculating the transmission line limit transmission power of the present invention are as follows:

[0147] Step S1: construct a transient stability analysis model of a power system including n synchronous generators and m frequency loads, eliminate the number of generations by network contraction, and eliminate the equilibrium manifold by taking the relative angle as the state variable;

[0148] Step S2: Expressing the power system transient stability analysis model in the form of a Lure type system;

[0149] Step S3: setting a candidate Lyapunov function, and obtaining an analytical expression of the candidate Lyapunov function by solving a linear matrix inequality;

[0150] Step S4: estimating the critical value corresponding to the Lyapunov function based on the transient stability criterion, and the set consisting of the Lyapunov function and the obtained critical value is an estimate of the stability domain;

[0151] Step S5: if the estimated critical value is less than the critical value threshold, the output power of the generator is reduced, and steps S1-S4 are repeated until the estimated critical value is slightly greater than the critical value threshold; if the estimated critical value is much greater than the critical value threshold, the output power of the generator is increased, and steps S1-S4 are repeated until the estimated critical value is slightly greater than the critical value threshold;

[0152] Step S6: Record the sum of the output powers of all generators connected to the head-end node of the target line at this time, which is the limit transmission power of the target line.

[0153] Indicatively, if the estimated critical value is less than the critical value threshold, this indicates that the current power system is not stable enough and there is a risk of instability. Therefore, it is necessary to reduce the output power of all generators connected to the headend node of the target line. Subsequently, the critical value evaluation operation is repeated to observe whether the adjusted system stability is improved. This process will continue until the estimated critical value is slightly greater than the critical value threshold, that is, the system stability reaches an acceptable level.

[0154] If the estimated critical value is much larger than the critical value threshold, it indicates that the current power system stability is too high and there is potential for further improvement in the transmission power. Therefore, it is necessary to increase the output power of all generators connected to the head end node of the target line. Similarly, the critical value evaluation operation is repeated to monitor the changes in system stability after the power is increased. This process will continue until the estimated critical value is slightly larger than the critical value threshold to maintain the stability of the system and maximize the transmission power.

[0155] When the difference between the estimated critical value and the critical value threshold is not greater than the preset difference threshold, it is considered that the system has reached a stable and efficient operating state. At this time, the sum of the output power of all generators connected to the head end node of the target line is recorded, and this value is the limit transmission power of the target line.

[0156] Therefore, the determination process of the present invention can accurately determine the limit transmission power of the target line by continuously adjusting the output power of the generator and repeatedly performing the critical value evaluation operation, and calculate the limit transmission power of the line from the perspective of transient stability, thereby solving the transient instability problem caused by excessive power transmission level, thereby ensuring the safe and stable operation of the power system.

[0157] In a preferred embodiment, Figure 4 , Figure 5 P0=P m1 +P m2 , P max =1.8(P m1 +P m2 ) corresponds to the optimal transient stability region in δ 21 -δ 31 Plane, δ 21 -δ 41 The area surrounded by the red solid line represents the optimal transient stability domain when the power transmitted by the line between nodes 7 and 8 is P0, and the area surrounded by the blue dotted line represents the optimal transient stability domain when the power transmitted by the line between nodes 7 and 8 is P max The optimal transient stability region corresponding to .

[0158] Then, when the critical value threshold is V thre =1, V e Taking 0.01, when the power transmitted by the line between nodes 7 and 8 is P0, the estimated critical value is 1.52; when the power transmitted by the line between nodes 7 and 8 is P max When the estimated critical value is 1.01, the corresponding power P max That is the maximum transmission power of line 7-8.

[0159] In this example, when the power transmitted by the line between nodes 7-8 is Pmax=1.8(Pm1+Pm2), although the estimated critical value decreases, it still meets the stability requirements, and the power is the maximum at this time, so Pmax is determined as the limit transmission power of line 7-8.

[0160] Therefore, the present invention can study the transient stability domain and critical value of the system at different power levels to obtain the limit transmission power that meets the stability requirements, so as to ensure that the system can remain stable in various operating scenarios.

[0161] like Figure 6 As shown, based on the above-mentioned embodiments of the method for determining the limit transmission power of various transmission lines, the present invention provides a corresponding device embodiment;

[0162] An embodiment of the present invention provides a device for determining a transmission power limit of a power transmission line, comprising: a model building module and a transmission power limit determining module;

[0163] The model building module is used to build a system stability model for describing the stability characteristics of the power system based on the frequency data of each load point in the transmission line and various operating indicators in the power system;

[0164] The limit transmission power determination module is used to repeatedly perform the following critical value evaluation operation until it is determined that the critical value is not less than the preset critical threshold value, and the difference between the critical value and the preset critical threshold value is not greater than the preset difference threshold value, and the current moment corresponding to the critical value being not less than the preset critical threshold value and the difference between the critical value and the preset critical threshold value being not greater than the preset difference threshold value is used as the target moment, and then the power corresponding to the transmission line at the target moment is used as the limit transmission power of the transmission line:

[0165] Obtain the current frequency value of each load point at the current moment, and the current operating index values ​​of the power system at the current moment;

[0166] After substituting each current frequency value and each current operation index value into the system stability model, solving the system stability model, and when the function value of the system stability model is minimum, taking the minimum function value as the critical value;

[0167] When it is determined that the critical value is less than a preset critical threshold, the power of each generator in the transmission line is reduced; otherwise, it is determined whether the difference between the critical value and the preset critical threshold is greater than a preset difference threshold, and when it is determined that the difference is greater than the preset difference threshold, the power of each generator in the transmission line is increased;

[0168] Update the current time and perform the next critical value evaluation operation.

[0169] It should be noted that the device embodiments described above are merely schematic, wherein the modules described as separate components may or may not be physically separated, and the components displayed as modules may or may not be physical modules, and may be located in one place or distributed on multiple network modules. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. In addition, in the accompanying drawings of the device embodiments provided by the present invention, the connection relationship between the modules indicates that there is a communication connection between them, which may be specifically implemented as one or more communication buses or signal lines. Those of ordinary skill in the art can understand and implement it without paying creative labor.

[0170] Those skilled in the art can clearly understand that, for the sake of convenience and simplicity, the specific working process of the device described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0171] Based on the above-mentioned embodiments of the method for determining the limit transmission power of various transmission lines, the present invention provides corresponding embodiments of terminal equipment items.

[0172] An embodiment of the present invention provides a terminal device, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein when the processor executes the computer program, it implements a method for determining the limiting transmission power of a transmission line as described in any method embodiment of the present invention.

[0173] The terminal device may be a computing terminal device such as a desktop computer, a notebook, a palm computer, a cloud server, etc. The terminal device may include, but is not limited to, a processor and a memory.

[0174] The processor may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor, etc. The processor is the control center of the terminal device, and uses various interfaces and lines to connect various parts of the entire terminal device.

[0175] The memory can be used to store the computer program, and the processor realizes various functions of the terminal device by running or executing the computer program stored in the memory and calling the data stored in the memory. The memory can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system, at least one application required for a function, etc.; the data storage area can store data created according to the use of the mobile phone, etc. In addition, the memory can include a high-speed random access memory, and can also include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), at least one disk storage device, a flash memory device or other volatile solid-state storage device.

[0176] Based on the above-mentioned embodiments of the method for determining the limit transmission power of various transmission lines, the present invention provides corresponding storage medium item embodiments.

[0177] An embodiment of the present invention provides a storage medium, which includes a stored computer program, wherein when the computer program is running, the device where the computer-readable storage medium is located is controlled to execute a method for determining the limit transmission power of a transmission line as described in any method embodiment of the present invention.

[0178] The storage medium is a computer-readable storage medium, and the computer program is stored in the computer-readable storage medium. When the computer program is executed by the processor, the steps of each method embodiment described above can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form, etc. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, USB flash drive, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electric carrier signal, telecommunication signal and software distribution medium, etc. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electric carrier signals and telecommunication signals.

[0179] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A method for determining the transmission power limit of a power transmission line, characterized in that: include: Based on the frequency data of each load point in the transmission line and various operating indicators in the power system, a system stability model is constructed to describe the stability characteristics of the power system; Repeat the following critical value evaluation operation until it is determined that the critical value is not less than the preset critical threshold value, and the difference between the critical value and the preset critical threshold value is not greater than the preset difference threshold value, and the current moment corresponding to the critical value being not less than the preset critical threshold value and the difference between the critical value and the preset critical threshold value being not greater than the preset difference threshold value is taken as the target moment, and then the power corresponding to the transmission line at the target moment is taken as the limit transmission power of the transmission line: Obtain the current frequency value of each load point at the current moment, and the current operating index values ​​of the power system at the current moment; After substituting each current frequency value and each current operation index value into the system stability model, solving the system stability model, and when the function value of the system stability model is minimum, taking the minimum function value as the critical value; When it is determined that the critical value is less than a preset critical threshold, the power of each generator in the transmission line is reduced; otherwise, it is determined whether the difference between the critical value and the preset critical threshold is greater than a preset difference threshold, and when it is determined that the difference is greater than the preset difference threshold, the power of each generator in the transmission line is increased; Update the current time and perform the next critical value evaluation operation.

2. A method for determining the transmission power limit of a power transmission line according to claim 1, characterized in that: The operation index of the power system includes: the angular velocity of the generator, the rotor angle between the generator and the reference generator, the steady-state rotor angle value used to characterize the rotor angle between the generator and the reference generator when the power system is in a stable operation state, the susceptance of each branch in the transmission network of the power system, the internal potential corresponding to the generator, the internal potential corresponding to the load point, and the angular velocity of the preset reference generator; Frequency data corresponding to each load point, including: frequency coefficient, frequency, and steady-state frequency value used to characterize the frequency of the load point when the power system is in a stable operating state; The system stability model for describing the stability characteristics of the power system is constructed according to the frequency data of each load point in the transmission line and each operation index in the power system, including: Generate a first function for characterizing the operation characteristics of the generator according to the frequency coefficient corresponding to each load point, the susceptance of each branch in the transmission network of the power system, the internal potential of the generator, the internal potential corresponding to the load point, the rotor angle difference between any two different generators, the steady-state rotor angle difference between any two different generators, and the angular velocity of a preset reference generator; Generate a second function for characterizing the operating characteristics of the load point according to the frequency coefficient corresponding to each load point, the susceptance of each branch in the transmission network of the power system, the internal potential of the generator, the internal potential corresponding to the load point, the frequency difference between any two different load points, the steady-state frequency difference between any two different load points, and the angular velocity of a preset reference generator; generating a target state vector for representing the operating state of the power system according to the deviation between the rotor angle of each generator and the steady-state rotor angle value, the deviation between the frequency of each load point and the steady-state frequency value, and the angular velocity of each generator; According to the first functional formula, the second functional formula, the target state vector, a preset system connection matrix for representing the network structure of the power system, and a trigonometric function for generating nonlinear terms, a third functional formula for describing the operation dynamics of the power system in the state space is generated; wherein the third functional formula includes: a nonlinear feedback term for describing the nonlinear dynamic behavior of the power system, and a linear term for describing the nonlinear dynamic behavior of the power system; According to a preset functional formula for describing the stability of a nonlinear dynamic system and the third functional formula, generating an analytical expression of the preset functional formula; The analytical expression of the preset functional formula is used as a system stability model for describing the stability characteristics of the power system.

3. A method for determining the transmission power limit of a power transmission line according to claim 2, characterized in that: The generating of a target state vector for characterizing the operating state of the power system according to the deviation between the rotor angle of each generator and the steady-state rotor angle value, the deviation between the frequency of each load point and the steady-state frequency value, and the angular velocity of each generator comprises: For each generator, a first state vector is generated according to a deviation between a rotor angle and a steady-state rotor angle value; generating a second state vector according to the angular velocity of each generator; For each load point, a third state vector is generated according to the deviation between the frequency and the steady-state frequency value; The first state vector, the second state vector and the third state vector are aggregated to generate a target state vector for representing the operating state of the power system.

4. A method for determining the transmission power limit of a power transmission line according to claim 3, characterized in that: The third functional formula comprises: Where x is the target state vector, A is the matrix corresponding to the linear term, and B is the matrix corresponding to the nonlinear feedback term; φ(Cx) is the linear term corresponding to the converted target state vector after the target state vector is converted based on the trigonometric function; when i is the i-th generator, then δ ij is the rotor angle difference between any two different generators in the branch, is the steady-state rotor angle difference between any two different generators in the branch; when i is the i-th load point, then δ ij is the frequency difference between any two different load points, is the steady-state frequency difference between any two different load points; E is the preset system connection matrix, δ 1n is the rotor angle between the generator and the reference generator, is the steady-state rotor angle value used to characterize the rotor angle between the generator and the reference generator when the power system is in a stable operating state, δ (n+m)n is the frequency corresponding to the load point, is the steady-state frequency value corresponding to the load point, which is used to characterize the frequency of the load point when the power system is in a stable operating state, and ε is the branch set in the transmission network of the power system.

5. A method for determining the transmission power limit of a power transmission line according to claim 4, characterized in that: The step of generating an analytical expression of the preset functional formula according to the preset functional formula for describing the stability of the nonlinear dynamic system and the third functional formula comprises: Generate a fourth functional formula including a target state vector and reflecting the stability of the power system according to a preset functional formula for describing the stability of the nonlinear power system and the third functional formula; Substituting the third functional expression into the derivative corresponding to the fourth functional expression to generate a linear matrix inequality corresponding to the third function; The linear matrix inequality is solved to generate an analytical expression of the preset functional formula.

6. The method for determining the transmission power limit of a power transmission line according to claim 1, characterized in that: The constraint conditions of the system stability model include: a nonlinear constraint for characterizing the nonlinear relationship between the operating index and the stability of the power system and a nonconvex constraint for characterizing that the transient stability domain of the system stability model has nonconvexity; The solving of the system stability model and taking the minimum function value as a critical value when the function value of the system stability model is minimum includes: Under nonlinear constraints and non-convex constraints, the system stability model is iteratively solved until the function value of the system stability model is minimum, and the minimum function value is used as the critical value.

7. A method for determining the transmission power limit of a power transmission line according to claim 6, characterized in that: The step of using the power corresponding to the transmission line at the target time as the limit transmission power of the transmission line includes: The sum of the output powers of all the generators connected to the head end node of the transmission line is taken as the limit transmission power of the transmission line.

8. A device for determining the transmission power limit of a power transmission line, characterized in that: include: A model building module and a limit transmission power determination module; The model building module is used to build a system stability model for describing the stability characteristics of the power system based on the frequency data of each load point in the transmission line and various operating indicators in the power system; The limit transmission power determination module is used to repeatedly perform the following critical value evaluation operation until it is determined that the difference between the critical value and the preset critical threshold value is not greater than the preset difference threshold value, and the current time corresponding to the time when the difference is not greater than the preset difference threshold value is used as the target time, and then the power corresponding to the transmission line at the target time is used as the limit transmission power of the transmission line: Obtain the current frequency value of each load point at the current moment, and the current operating index values ​​of the power system at the current moment; After substituting each current frequency value and each current operation index value into the system stability model, solving the system stability model, and when the function value of the system stability model is minimum, taking the minimum function value as the critical value; When it is determined that the critical value is less than a preset critical threshold, the power of each generator in the transmission line is reduced, or when it is determined that the difference between the critical value and the preset critical threshold is greater than a preset difference threshold, the power of each generator in the transmission line is increased; Update the current time and perform the next critical value evaluation operation.

9. A terminal device, characterized in that: The method comprises a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein when the processor executes the computer program, a method for determining the limit transmission power of a transmission line as claimed in any one of claims 1 to 7 is implemented.

10. A storage medium, characterized in that: The storage medium includes a stored computer program, wherein when the computer program is executed, the device where the storage medium is located is controlled to execute a method for determining the limit transmission power of a transmission line according to any one of claims 1 to 7.

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