NSGA-II based parameter optimization design method for high-frequency ice-melting power supply

Abstract

This invention provides a high-frequency de-icing power supply parameter design method based on NSGA-II, comprising the following steps: Step 1: Establishing an equivalent uniform transmission line model under high-frequency excitation of the iced line; Step 2: Solving the equivalent uniform transmission line circuit model under high-frequency excitation of the iced line to obtain key high-frequency de-icing data, including: line voltage, line current, and line thermal power; Step 3: Constructing a high-frequency online de-icing multi-objective optimization model; Step 4: Solving the high-frequency online de-icing multi-objective optimization model to obtain the high-frequency de-icing power supply parameters; This solves the problem of difficulty in determining de-icing power supply parameters in existing high-frequency de-icing technologies.

Description

Technical Field

[0001] This invention belongs to the field of power transmission line de-icing technology, and in particular relates to a high-frequency de-icing power supply parameter optimization design method based on NSGA-II. Background Technology

[0002] Over the past few decades, icing of transmission lines has been a common problem due to cold weather. In severe cases, it can even cause the power grid to disconnect, leading to large-scale power grid paralysis, which is a major hidden danger to the power system.

[0003] Therefore, many researchers have conducted studies on de-icing technology for iced power lines. Currently, AC power frequency short-circuit de-icing and DC short-circuit de-icing are the most widely used and mature de-icing methods. AC power frequency short-circuit de-icing, due to the high reactance of transmission lines, leads to wasted reactive power and is generally only suitable for lines with voltage levels below 220kV. DC de-icing power supplies are expensive, increasing de-icing costs, and both require relatively long downtime. Therefore, exploring new and efficient online de-icing technologies remains one of the important issues facing the power system.

[0004] High-frequency de-icing technology is a novel de-icing technique proposed by McCurdy JD et al., based on the significant enhancement of dielectric loss and skin effect under mid-to-high frequency excitation. Due to the skin effect and dielectric loss, high-frequency de-icing can still generate significant heat even with relatively small de-icing currents. Furthermore, the high-frequency notch filter allows for the distinction between high-frequency and power frequency components, making online de-icing possible. The key technology is the fabrication of a high-frequency de-icing power supply. In recent years, the rapid development of power electronic devices has provided technical support for the development of high-frequency de-icing power supplies, and high-frequency de-icing technology has attracted increasing attention from scholars. However, most scholars have not considered, from the perspective of online de-icing, that the superposition of high-frequency and power frequency components may exceed the constraints of the conductor. Moreover, the critical de-icing power is based on the traditional AC / DC de-icing heat transfer problem; the difference between the dielectric heat distribution of the ice layer and the ohmic heat distribution of the conductor will affect the critical de-icing power by influencing the outer surface temperature of the ice layer. Summary of the Invention

[0005] The purpose of this invention is to provide a high-frequency de-icing power supply parameter optimization design method based on NSGA-II, so as to solve the problem that the de-icing power supply parameters are difficult to determine in existing high-frequency de-icing technologies.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is a method for designing high-frequency de-icing power supply parameters based on NSGA-II, comprising the following steps:

[0007] Step 1: Establish an equivalent uniform transmission line model under high-frequency excitation of an icing-covered line;

[0008] Step 2: Solve the equivalent uniform transmission line circuit model under high-frequency excitation of the icing line to obtain key data for high-frequency de-icing, including: voltage along the line, current along the line, and thermal power along the line.

[0009] Step 3: Construct a high-frequency online ice melting multi-objective optimization model;

[0010] Step 4: Solve the high-frequency online ice melting multi-objective optimization model to obtain the high-frequency ice melting power supply parameters.

[0011] Furthermore, step one specifically refers to: establishing a distributed parameter circuit for the icing-affected line, consisting of a series of lumped elements, including a lumped circuit of length elements dx, where each length element dx consists of a series resistor R0dx, a series inductor L0dx, and a parallel capacitor C. eq dx and parallel resistance G eq The circuit consists of a series resistor R0dx and a series inductor L0dx connected in series and then connected in series to the icing circuit, with a parallel capacitor C. eq dx and parallel resistance G eq After being connected in parallel, dx is then connected in parallel to the icing-covered line.

[0012] Furthermore, the specific calculation formulas for each parameter in the equivalent uniform transmission line model under high-frequency excitation of the icing line established in step one are as follows:

[0013]

[0014] In the formula, σ is the conductivity of the conductor, μ0 is the permeability of free space, ε0 is the permittivity of free space, and ε r tanδ is the real part of the relative permittivity of the ice layer, tanδ is the tangent of the dielectric loss angle of the ice layer, and μ r d is the relative permeability of the conductor, d is the skin effect depth, and h is the relative permeability of the conductor. d C is the height of the conductor center above the ground. ice G is the equivalent capacitance of the ice layer. ice Let R0 be the equivalent conductance of the ice layer, C be the equivalent capacitance of the ice layer to the ground, d be the skin depth, ω be the angular frequency, r1 be the radius of the conductor, r2 be the radius of the conductor after it is covered with ice, and R0, L0, C be the equivalent conductance of the ice layer. eq G eq These represent the resistance, inductance, capacitance, and conductance per unit length of the transmission line at the corresponding power supply frequency, where f is the power supply frequency.

[0015] Furthermore, in step two, the voltage along the line... Current along the line Thermal power P along the line sum The expression is as follows:

[0016]

[0017]

[0018] In the formula, Z represents the voltage phasor of the de-icing power supply, x represents the distance from the power supply terminal, l is the length of the iced line, γ = α + jβ is the propagation constant, α and β are the real and imaginary parts of γ, and Z is the distance from the power supply terminal. c I is the wave impedance of the line. x V x These are the currents along the line. Voltage The effective value of R, where I is the effective value of the power frequency current, and R is the effective value of the power frequency current. dc P is the DC resistance of the wire. ohm P die Here, e is the Ohmic heat and dielectric heat along the line during online ice melting, R0 is the resistance per unit length of the conductor at the corresponding power frequency, and G is the resistance of the conductor. eq This represents the conductivity per unit length of a conductor at the corresponding power frequency.

[0019] Furthermore, the objective function of the high-frequency online ice melting multi-objective optimization model in step three includes: maximizing the power uniformity f1(f,U) s Maximize the minimum heat along the line f2(f,U) s Minimize the high-frequency ice-melting power supply frequency f3(f,U) s Minimize the high-frequency de-icing power supply voltage f4(f,U) s The specific formula is:

[0020]

[0021] f2(f,U s ) = min(P sum (x))

[0022] f3(f,U s )=f

[0023] f4(f,U s )=U s

[0024] In the formula, min(P) sum (x) represents the minimum heat along the line; max(P) sum (x) represents the maximum heat along the line, f is the power supply frequency, and U s P is the power supply voltage value. sum This indicates the thermal power along the line.

[0025] Furthermore, the constraints of the high-frequency online de-icing multi-objective optimization model in step three include: conductor allowable current carrying capacity constraint, conductor withstand voltage constraint, power factor constraint at the power supply end, and critical de-icing power constraint, wherein,

[0026] Critical melting power constraint refers to:

[0027]

[0028] In the formula, t e λ is the ambient temperature; λ1 and λ2 are the thermal conductivity coefficients of the conductor and the ice layer, respectively; h is the convective heat transfer coefficient of the outer surface of the ice layer; S1 is the radiative heat dissipation coefficient of the outer surface of the ice layer; E1 is the Stenfan-Boltcoman constant, with a value of 5.67 × 10⁻⁶. -8 W / (m 2 ·K 4 ); r1 and r2 are the radii of the conductor and the conductor after it becomes icy, respectively; P ohm For the ohmic heat along the line during online ice melting, P die For the heat of the medium along the line during online ice melting;

[0029] The allowable current carrying capacity constraint for conductors must satisfy the following formula:

[0030]

[0031] Where h is the convective heat dissipation coefficient, calculated according to the following formula:

[0032]

[0033] In the formula, I x Current along the line The effective value of R dc R0 is the DC resistance of the conductor, R0 is the resistance per unit length of the conductor at the corresponding power supply frequency, μ is the air density, and ρ is the resistance per unit length of the conductor. a Where V is the air viscosity coefficient, I is the wind speed, and V is the wind speed. max W is the maximum allowable current carrying capacity of the line. F W R W S These represent heat dissipation through convective heat transfer, radiative heat transfer, and heat absorption by light on the outer surface of the conductor, respectively. max A is the highest permissible temperature for the conductor. s J is the heat absorption coefficient of the conductor surface. s Light intensity;

[0034] Power factor constraint at the power supply end refers to:

[0035]

[0036] In the formula, l is the length of the icing line, γ=α+jβ is the propagation constant, and Z c The wave impedance of the line;

[0037] Conductor withstand voltage constraint refers to:

[0038]

[0039] In the formula, k ac V is the overvoltage multiple of the AC line. ac V represents the effective value of the AC line voltage to ground. x voltage along the line The effective value;

[0040] It also includes other constraints and conditions:

[0041]

[0042] In the formula, U s_min U s_max These are the power supply voltages U and U, respectively. s The upper and lower limits, f min f max These are the upper and lower limits of the power supply frequency f, respectively.

[0043] Further, step four specifically involves: using the NSGA-II algorithm to solve the multi-objective optimization model established in step three to obtain the optimal solution set, specifying the weights of different objective functions, and sorting the high-frequency ice melting power parameters according to the TOPSIS method.

[0044] Furthermore, it also includes step five: verifying the effectiveness of the high-frequency de-icing power supply parameters through finite element simulation; specifically, using COMSOL software to perform electromagnetic thermal coupling simulation on the minimum hot spot along the line corresponding to the solved high-frequency power supply parameters, where voltage is used as electric field excitation and current is used as magnetic field excitation: voltage is used as electric field to obtain dielectric heat, and current is used as magnetic field to obtain ohmic heat; dielectric heat and ohmic heat are coupled together as heat sources to the solid heat transfer module, and the obtained temperature distribution is used to verify the effectiveness of de-icing.

[0045] The beneficial effects of this invention are:

[0046] This invention analyzes the heat transfer problem of high-frequency online ice melting and derives an objective function and constraints that are more suitable for high-frequency online ice melting. The high-frequency ice melting power supply parameter design method based on NSGA-II can design ice melting power supply parameters applicable to different scenarios by setting different weights, while satisfying the conductor constraints. This has significant implications for the realization of high-frequency online ice melting. Attached Figure Description

[0047] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0048] Figure 1 This is a flowchart illustrating the high-frequency de-icing power supply parameter design method based on NSGA-II according to an embodiment of the present invention.

[0049] Figure 2 This is a circuit model diagram of a classic uniform transmission line with an icing conductor according to an embodiment of the present invention.

[0050] Figure 3 This is a schematic diagram of the critical melting power according to an embodiment of the present invention.

[0051] Figure 4 This is a flowchart of the multi-objective optimization algorithm according to an embodiment of the present invention.

[0052] Figure 5 These are graphs showing the temperature changes of the inner and outer surfaces of the ice layer over time under different parameters according to embodiments of the present invention; wherein, (a) is a graph showing the temperature changes of the inner and outer surfaces of the ice layer over time under parameter one, (b) is a graph showing the temperature changes of the inner and outer surfaces of the ice layer over time under parameter two, and (c) is a graph showing the temperature changes of the inner and outer surfaces of the ice layer over time under parameter three. Detailed Implementation

[0053] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0054] This invention addresses the power supply frequency and voltage design problems in high-frequency, high-voltage online ice melting, and discloses a multi-objective optimization design method for high-frequency ice melting power supply parameters based on NSGA-II. First, based on uniform transmission line theory, an equivalent transmission line circuit model of the iced conductor under high-frequency excitation is established. Then, starting from engineering practice and combining the thermal balance principle of high-frequency online ice melting, the objective function and constraints for high-frequency ice melting are derived. Finally, the Pareto optimal solution set is obtained through the NSGA-II algorithm, and the required ice melting power supply parameters are selected according to the TOPSIS method. Figure 1 As shown, the specific steps are as follows:

[0055] Step 1: Establish an equivalent uniform transmission line model under high-frequency excitation of the icing line.

[0056] Specifically, establishing the equivalent uniform transmission line model under high-frequency excitation of the icing line in step one refers to: based on the theory of uniform transmission lines and electromagnetic knowledge, establishing a distributed parameter circuit for the icing line, consisting of a series of lumped elements and containing many infinitesimal length elements dx, where each length element dx consists of a series resistor R0dx, a series inductor L0dx, and a parallel capacitor C.eq dx and parallel resistance G eq The circuit consists of a series resistor R0dx and a series inductor L0dx connected in series and then connected in series to the icing circuit, with a parallel capacitor C. eq dx and parallel resistance G eq After being connected in parallel, the dx lines are connected in parallel to the icing lines, as detailed below. Figure 2 As shown, the relevant calculation formulas are as follows:

[0057]

[0058] In the formula, σ is the conductivity of the conductor, μ0 is the permeability of free space, ε0 is the permittivity of free space, and ε r tanδ is the real part of the relative permittivity of the ice layer, tanδ is the tangent of the dielectric loss angle of the ice layer, and μ r d is the relative permeability of the conductor, d is the skin effect depth, and h is the relative permeability of the conductor. d C is the height of the conductor center above the ground. ice G is the equivalent capacitance of the ice layer. ice R0, L0, and C represent the equivalent conductance of the ice layer, C is the equivalent capacitance of the ice layer to the ground, d is the skin depth, ω is the angular frequency, r1 is the radius of the conductor, r2 is the radius of the conductor after it is covered with ice, and R0, L0, and C are also relevant. eq G eq These represent the resistance, inductance, capacitance, and conductance per unit length of the conductor at the corresponding power supply frequency, respectively, where f is the power supply frequency.

[0059] Step 2: Solve the equivalent uniform transmission line circuit model under high-frequency excitation of the icing line to obtain key data for high-frequency de-icing, including: voltage along the line, current along the line, and thermal power along the line.

[0060] Specifically, solving the equivalent uniform transmission line circuit model under high-frequency excitation of the icing line in step two above refers to: Figure 1 Write the KCL equations for circuit node a, and the KVL equations for loop 1, substituting the starting voltage. Terminal voltage The voltage along the line can then be obtained. Current along the line The expression for the heat power along the line is as follows:

[0061]

[0062]

[0063] In the formula, Z represents the voltage phasor of the de-icing power supply, x represents the distance from the power supply terminal, l is the length of the line to be de-iced (iced), γ=α+jβ is the propagation constant (α, β are the real and imaginary parts of γ), and Z c I is the wave impedance of the line. x Vx Current along the line and voltage The effective value of R, where I is the effective value of the power frequency current (representing the normal load current of the line), and R dc P is the DC resistance of the wire. ohm P die P sum Let represent the ohmic heat along the line, the heat of the medium along the line, and the total thermal power during online ice melting, with e being the natural constant.

[0064] Step 3: Derive the high-frequency online ice melting multi-objective optimization model. The objective function includes: maximizing power uniformity f1(f,U) s Maximize the minimum heat along the line f2(f,U) s Minimize the high-frequency ice-melting power supply frequency f3(f,U) s Minimize the high-frequency de-icing power supply voltage f4(f,U) s The constraints include: conductor current carrying capacity constraint, conductor withstand voltage constraint, power factor constraint at the power supply end, and critical de-icing power constraint.

[0065] Step three above uses the melting parameters that are worth optimizing and can be sacrificed in the high-frequency melting process as the objective function, and the insurmountable conditions in the high-frequency melting process as the constraints, as follows:

[0066] Objective function:

[0067] (1) Maximize power uniformity: Since the heat is inconsistent at different points along the high-frequency de-icing line, in order to ensure uniform de-icing throughout the line, and at the same time, to effectively reduce the power supply capacity by ensuring that the difference between the maximum and minimum heat is not large, the power uniformity is maximized. The expression for power uniformity is as follows:

[0068]

[0069] In the formula, min(P) sum (x) represents the minimum total heat along the line, i.e., the minimum heat along the line; max(P) sum (x) represents the maximum total heat along the line, i.e., the maximum heat along the line.

[0070] (2) Maximize the minimum heat along the line: The melting process ends at the location of the minimum heat along the line as the standard for the end of melting along the entire line. Melting time is reduced by maximizing the minimum heat along the line. The minimum heat along the line is the minimum value of the total heat along the line, as shown in the following formula:

[0071] f2(f,U s ) = min(P sum (x))

[0072] (3) Minimize power supply frequency: One of the unavoidable drawbacks of high-frequency de-icing is that the mid-to-high frequency excitation will cause radio interference in high-voltage transmission lines. Therefore, the power supply frequency for de-icing should be minimized to reduce radio interference.

[0073] f3(f,U s )=f

[0074] (4) Minimize power supply voltage: Considering the complexity of the power electronic devices in the ice melting power supply, minimize the power supply voltage.

[0075] f4(f,U s )=U s

[0076] Where f1-f4 represent the 1st to 4th objective functions, and f and U in parentheses s The independent variables in the formula, which are also the control variables in the multi-objective model, are the power supply frequency f and the power supply voltage U. s .

[0077] Constraints:

[0078] (1) Critical De-icing Power Constraint: De-icing can only be effective when the line heating meets the critical de-icing power condition. Therefore, it is essential to ensure that the heat power generated by the high-frequency power supply at all points along the line meets the critical de-icing power condition. The formula is as follows:

[0079]

[0080] In the formula, t e λ is the ambient temperature; λ1 and λ2 are the thermal conductivity coefficients of the conductor and the ice layer, respectively; h is the convective heat transfer coefficient of the outer surface of the ice layer; S1 is the radiative heat dissipation coefficient of the outer surface of the ice layer; E1 is the Stefan-Boltcoman constant, with a value of 5.67 × 10⁻⁶. -8 W / (m 2 ·K 4 ); r1 and r2 are the radii of the conductor and the conductor after icing, respectively; for easier understanding of the above formula, Figure 3 It is based on the ohm heat P ohm The horizontal axis represents the thermal properties of the medium, P. die The diagram is plotted based on the above formula with the vertical axis as the ordinate. When the scattered points depicted by the thermal power at various points along the line are all above the critical melting power line, the ice can be melted.

[0081] (2) Maximum allowable current carrying capacity constraint: Due to inconsistent power uniformity, the area with the highest total heat along the line melts ice first. However, to ensure ice melting along the entire line, the ice melting power supply continues to operate, causing the temperature at the area with the highest total heat to rise further. To ensure that the area with the highest total heat does not exceed the allowable temperature of the conductor during ice melting, a constraint on the conductor's current carrying capacity is required. This constraint must satisfy the following formula:

[0082]

[0083] Where h is the convective heat dissipation coefficient, calculated according to the following formula:

[0084]

[0085] In the formula, μ is the air density, ρ a λ is the air viscosity coefficient, V is the wind speed, and λ is the air viscosity coefficient. a I is the thermal conductivity of air. max W is the maximum allowable current carrying capacity of the line. F W R W S These represent heat dissipation through convective heat transfer, radiative heat transfer, and heat absorption by light on the outer surface of the conductor, respectively. max A is the highest permissible temperature for the conductor. s J is the heat absorption coefficient of the conductor surface. s Light intensity.

[0086] (3) Power Factor Constraint at the Power Supply Terminal: High-frequency de-icing is a type of AC de-icing. The magnitude of the power factor at the power supply terminal determines the power supply capacity. To reduce the capacity of the high-frequency power supply, the power factor at the power supply terminal needs to be constrained. The following formula applies:

[0087]

[0088] (4) Conductor withstand voltage constraint: Since the voltage along the line under high frequency excitation exhibits a quasi-standing wave distribution, it is necessary to ensure that the superposition of the high frequency voltage and the power frequency voltage of the normal load of the line does not exceed the insulation level of the transmission line, and the following formula must be satisfied.

[0089]

[0090] In the formula, k ac V is the overvoltage multiple of the AC line. ac This represents the effective value of the AC line voltage to ground.

[0091] (5) Other constraints: In designing high-frequency power supply parameters, in order to meet the rationality of power electronic devices and avoid electromagnetic interference, constraints must be imposed on the power supply frequency and power supply voltage.

[0092]

[0093] U s_min U s_max These are the upper and lower limits of the power supply voltage, f. min f max These are the upper and lower limits of the power supply frequency, respectively.

[0094] At this point, the high-frequency ice melting multi-objective optimization model has been established.

[0095] Step 4: Solve the ice-melting model to obtain the ice-melting power parameters.

[0096] For detailed procedures of step four above, please refer to [link / reference]. Figure 4 That is, the NSGA-II algorithm is used to solve the multi-objective optimization model established in step three to obtain the optimal solution set, and the weights of different objective functions are specified. The required high-frequency ice melting power parameters are obtained by sorting according to the TOPSIS method.

[0097] In this embodiment, three different weights are specified for the following three operating conditions: γ1, γ2, γ3, and γ4 represent the weights of power uniformity, minimum heat along the line, de-icing power supply frequency, and de-icing power supply voltage, respectively.

[0098] (1) Simultaneously considering the ice melting power parameters and the minimum heat along the line, γ1=0.05, γ2=0.33, γ3=0.34, γ4=0.28.

[0099] (2) When icing can cause significant damage, only rapid ice melting is ensured, without considering radio interference and increased complexity of power electronic devices caused by higher frequencies and voltages in the ice melting power supply. That is, by setting γ1 = 0, γ2 = 1, γ3 = 0, and γ4 = 0, the parameters that maximize the minimum heat along the line can be obtained.

[0100] (3) When the icing is not very severe, only the power supply parameters are considered to be minimized, without considering the speed of ice melting. That is, by setting γ1=0, γ2=0, γ3=0.5, γ4=0.5, the parameters that minimize the power supply frequency and voltage can be obtained.

[0101] The relevant parameters selected in this embodiment are: λ1=237W / (m·k), λ2=2.3W / (m·k), λ a =0.0244W / (m·k), h d =12m, l=50km, r1=0.01m, r2=0.02m, σ=3×10 7 m, μ r =1,ε r =3, tanδ=1, t max =90℃, t e = -10℃, J S =0W / m 2 S1 = 0.9, A s =0.9, k ac =2, V=5m / s, V ac =110kV, f min =1000Hz, f max =100kHz, U s_min=1000V, U s_max =20kV, μ=1.72×10 -5 kg / (m·s), I=500A.

[0102] The required parameters for the de-icing power supply are shown in Table 1.

[0103] Table 1 Key data for 3 sets of parameters

[0104]

[0105] Step 5: Verify the effectiveness of the selected high-frequency ice-melting power supply parameters using finite element simulation.

[0106] Step five specifically refers to using COMSOL software to perform electromagnetic thermal coupling simulation on the minimum hot spot along the line corresponding to the three sets of high-frequency power parameters obtained from the solution. Voltage and current are used as electric field and magnetic field excitation, respectively. The former (voltage as electric field) generates dielectric heat, and the latter (current as magnetic field) generates ohmic heat. Dielectric heat and ohmic heat are coupled together as heat sources to the solid heat transfer module to obtain the temperature distribution for verifying the effectiveness of ice melting.

[0107] The changes in the inner and outer surfaces of the ice layer over time were obtained as follows: Figure 5 As shown, it can be seen that the outer surface temperature of the ice layer corresponding to the minimum heat along the line for parameters one, two, and three exceeds 0℃ in 3.3h, 0.4h, and 24h respectively, which can be regarded as the time required to complete the ice melting. The required time decreases as the weight γ2 of the minimum heat increases. Among them, parameter 2 completes the ice melting in only 0.4h, while parameter 3 takes as long as 24h. This is because the weights γ2 of the minimum heat along the line are 1 and 0 respectively. Therefore, the simulation results are consistent with the weight settings of the objective function.

[0108] The various embodiments in this specification are described in a related manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0109] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A high-frequency ice-melting power parameter design method based on NSGA-II, characterized in that, The method comprises the following steps: Step one: establishing an equivalent uniform transmission line model under high-frequency excitation of the iced line; Step two: solving the equivalent uniform transmission line circuit model under high-frequency excitation of the iced line to obtain high-frequency ice-melting key data, including: line voltage, line current, and line thermal power; Step three: constructing a high-frequency online ice-melting multi-objective optimization model; Step four: solving the high-frequency online ice-melting multi-objective optimization model to obtain high-frequency ice-melting power supply parameters; The objective function of the high-frequency on-line ice-melting multi-objective optimization model in step three includes: maximizing power uniformity , maximizing minimum heat along the line , minimizing high-frequency ice-melting power frequency , minimizing high-frequency ice-melting power voltage , and the specific formula is: ； ； ； ； wherein represents the minimum heat along the line; represents the maximum heat along the line, f is the power supply frequency, U s is the power supply voltage value, represents the heat power along the line; The constraint conditions of the high-frequency online ice-melting multi-objective optimization model in step three include: conductor allowable current-carrying capacity constraint, conductor withstand voltage constraint, power supply end power factor constraint, and critical ice-melting power constraint, wherein, The critical ice-melting power constraint refers to: ； wherein t e is the ambient temperature; are the thermal conductivities of the wire and ice layer, respectively; h is the convective heat transfer coefficient of the outer surface of the ice layer; S 1is the radiative heat transfer coefficient of the outer surface of the ice layer; E 1is the Stefan-Boltzmann constant, which has a value of: ; r 1, r 2are the radii of the wire and the iced wire, respectively; is the Ohmic heat along the wire during ice melting, is the medium heat along the wire during ice melting, The conductor allowable current-carrying capacity constraint refers to the need to meet the following formula: ； wherein h is the convection heat loss coefficient, calculated as follows: ； wherein is the effective value of the current along the line, is the DC resistance of the line, R 0 is the resistance per unit length of the line at the corresponding power supply frequency, is the air density, is the air viscosity coefficient, V is the wind speed, is the air thermal conductivity, I max is the maximum current-carrying capacity allowed for the line, W F , W R , W S is the heat dissipation by convection, the heat dissipation by radiation and the heat absorption by light, respectively, of the outer surface of the line, t max is the maximum temperature allowed for the line, A s is the heat absorption coefficient of the surface of the line, J s is the light intensity;​ The power supply end power factor constraint refers to: ； wherein l is the length of the iced line, is the propagation constant, Z c is the wave impedance of the line; The conductor withstand voltage constraint refers to: ； wherein k ac is the overvoltage factor for the AC line, V ac is the effective value of the AC line-to-ground voltage, is the effective value of the voltage along the line the effective value of the voltage along the line Other constraint conditions are also included: ； In the formula, U s_min , U s_max These are the power supply voltages. The upper and lower limits, f min , f max These are the power supply frequencies. The upper and lower limits.

2. The method of claim 1, wherein the method is based on NSGA-II for high frequency de-icing power supply parameter design. The step one is specifically to establish a series of lumped elements for the icing line, including length elements dx Distributed parameter circuit of lumped circuit, each length element dx By series resistance R 0 dx , series inductance L 0 dx , parallel capacitance C eq dx And parallel resistance G eq dx Composed of, wherein the series resistance R 0 dx And series inductance L 0 dx Series after series access to the icing line, parallel capacitance C eq dx And parallel resistance G eq dx Parallel after parallel access to the icing line.

3. The method of claim 2, wherein the method is based on NSGA-II for high frequency de-icing power supply parameter design. The specific calculation formula of each parameter in the equivalent uniform transmission line model under high-frequency excitation of the iced line established in step one is as follows: ； wherein, is the wire conductivity, is the vacuum permeability, is the vacuum permittivity, is the ice layer relative permittivity real part, is the ice layer dielectric loss tangent, is the wire relative permeability, d is the skin depth, is the wire center height above ground, G ice is the ice layer equivalent capacitance, G ice is the ice layer equivalent conductance, C is the ice layer equivalent capacitance to ground, d is the skin depth, is the angular frequency, r 1 is the wire radius, r 2 is the wire radius after icing, R 0, L 0, C eq , G eq R, L, C, G represent the resistance, inductance, capacitance, conductance per unit length of the transmission line at the power frequency, respectively, f is the power frequency.

4. The NSGA-II based high frequency de-icing power supply parameter design method according to claim 1, wherein, The step two line voltage The step two line current The step two line thermal power The expression is as follows: ； ； wherein, represents the ice-melting power supply voltage phasor, x represents the distance from the power supply end, l is the length of the iced line, is the propagation constant, is the real and imaginary parts of, Z c is the wave impedance of the line, , is the effective value of the current , voltage along the line, respectively, is the effective value of the power frequency current, is the DC resistance of the conductor, , is the Ohmic heat along the line and the dielectric heat along the line when melting ice, e is the natural constant, R 0 is the resistance per unit length of the conductor at the power supply frequency, G eq represents the conductance per unit length of the conductor at the power supply frequency.

5. The method of claim 1, wherein the method is based on NSGA-II for high frequency de-icing power supply parameter design. Step four specifically refers to: using the NSGA-II algorithm to solve the multi-objective optimization model established in step three to obtain an optimal solution set, and specifying the weights of different objective functions, and then ranking the high-frequency ice-melting power supply parameters according to the TOPSIS method.

6. The NSGA-II based high frequency de-icing power supply parameter design method according to claim 1, characterized in that, Step five: verifying the effectiveness of the high-frequency ice-melting power supply parameters through finite element simulation; specifically, using the comsol software to perform electromagnetic-thermal coupling simulation on the minimum heat along the line corresponding to the high-frequency power supply parameters, wherein the voltage is used as the electric field excitation, and the current is used as the magnetic field excitation: the voltage is used as the dielectric heat, and the current is used as the ohmic heat; The dielectric heat and the ohmic heat are coupled to the solid heat transfer module as heat sources, and the obtained temperature distribution is used to verify the ice-melting effectiveness.

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