A Transmission Line Dynamic Load Management Method Based on Load Feedback Regulation

Abstract

The present invention relates to the technical field of power transmission control, and particularly relates to a dynamic load management method for a power transmission line based on load feedback regulation, including: estimating the temperature of the first temperature-rise conductor after a predetermined time period for the line to be evaluated and calculating the first dynamic long-term current-carrying capacity; determining the range of current-carrying capacity values according to the first dynamic long-term current-carrying capacity, and estimating the temperature of the second temperature-rise conductor; calculating the second dynamic long-term current-carrying capacity at the temperature of the second temperature-rise conductor, and then screening to obtain the actual dynamic long-term current-carrying capacity. Aiming at the problem that the existing dynamic rating technology has insufficient response to load changes, by pre-estimating the temperature rise and current-carrying capacity after a predetermined time period for each line to be evaluated, the available range of current-carrying capacity of the line is determined, and then feasible current-carrying capacity parameters are searched within this range and the corresponding temperature rise conditions are estimated, so that the error between the finally estimated temperature rise and current-carrying capacity conditions is small, and accurate control of the line is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of power transmission control, and particularly relates to a dynamic load management method for power transmission lines based on load feedback regulation. Background Art

[0002] Power transmission control refers to the process of allocating various parameters according to the line operating conditions in a high-voltage power transmission system. Since the capacity of a power transmission line is affected by various environmental parameters, for example, when the environmental temperature is high, the allowable operating temperature range of the line becomes narrower, and the available line capacity will decrease. Incorrectly estimating the line capacity will lead to a significant reduction in economic benefits. Therefore, it is necessary to accurately estimate and timely control various parameters during power transmission. The stable operation of the existing power system depends on the precise control of the power transmission line capacity by power system dispatchers. However, the traditional power system operation mode usually adopts the thermal rating of power transmission lines based on static environmental conditions, and this method does not fully utilize the capacity margin in the actual operating environment. With the digital development of the power system, how to more efficiently utilize the existing power transmission network resources has become an urgent need. In recent years, the Dynamic Line Rating (DLR) technology has gradually received wide attention because it can be adjusted according to real-time environmental conditions to ensure that the power transmission line operates close to its maximum limit. Especially by combining regional meteorological conditions, the DLR technology has obvious advantages in improving the operation efficiency of power transmission lines and ensuring safe and stable operation.

[0003] Although the DLR technology has certain flexibility compared with the traditional static rating, there are still many deficiencies in the current technology. Most of the existing dynamic capacity increase monitoring systems dynamically adjust the current-carrying capacity of overhead lines based on real-time data. However, these systems only provide the capacity information at the current moment and cannot provide effective decision-making support for power system dispatchers under future load changes.

[0004] First, the traditional calculation method of the dynamic current-carrying capacity of power transmission lines depends on real-time regional meteorological conditions, while the operation planning of the power market usually needs to be carried out several hours or even one day in advance. This will lead to a lag in decision-making information, making it difficult for dispatchers to accurately predict future line capacity changes and increasing the risk of system operation. Second, the short-term meteorological prediction model also has limitations in practical applications. The current short-term prediction only relies on the meteorological model, and the meteorological model itself has prediction errors and is difficult to provide accurate meteorological data, resulting in dispatchers being difficult to trust the predicted current-carrying capacity in practical applications. Finally, the existing DLR technology fails to effectively respond to sudden load changes. Due to not fully considering the impact of load changes on line temperature and future dynamic current-carrying capacity, the current DLR technology cannot be accurately adjusted in a timely manner when the load fluctuates violently, posing a safety hazard. Summary of the Invention

[0005] In view of the above problems existing in the prior art, a dynamic load management method for transmission lines based on load feedback regulation is provided herein.

[0006] The specific technical solution is as follows:

[0007] A dynamic load management method for transmission lines based on load feedback regulation, characterized by comprising:

[0008] Step S1: Construct a state vector for the line to be evaluated and estimate the temperature of the first temperature-rise conductor after a predetermined time period;

[0009] Step S2: Estimate the first dynamic long-term current-carrying capacity based on the temperature of the first temperature-rise conductor;

[0010] Step S3: Determine the value range of the current-carrying capacity of the second dynamic long-term current-carrying capacity for the line to be evaluated according to the first dynamic long-term current-carrying capacity, and estimate the temperature of the second temperature-rise conductor after the line to be evaluated has operated for a predetermined time according to the value range of the current-carrying capacity;

[0011] Step S4: Calculate the second dynamic long-term current-carrying capacity at the temperature of the second temperature-rise conductor;

[0012] Step S5: Determine whether the error between the second dynamic long-term current-carrying capacity and the predicted current-carrying capacity in the value range of the current-carrying capacity is within the error setting range;

[0013] If so, output the second dynamic long-term current-carrying capacity as the actual dynamic current-carrying capacity;

[0014] If not, increase the predetermined time by a preset step length, and then return to Step S3;

[0015] On the other hand, in Step S1, the method for generating the temperature of the first temperature-rise conductor includes:

[0016] ;

[0017] In the formula, is the temperature of the first temperature-rise conductor;

[0018] is t the conductor temperature at t = 0;

[0019] is the initial temperature rise under the current operating current ;

[0020] is the heat generated by the AC resistance per unit length of the conductor under the initial conditions;

[0021] is the solar heat absorption per unit length of the wire under the initial conditions;

[0022] is the convective heat dissipation per unit length of the wire under the initial conditions;

[0023] is the radiative heat dissipation per unit length of the wire under the initial conditions;

[0024] dt is the time increment, dt =Δ t 。

[0025] On the other hand, the step S1 includes:

[0026] Step S11: Collect heat parameter information for the line to be evaluated;

[0027] Step S12: Generate an initial temperature rise according to the heat parameter information;

[0028] Step S13: Generate the temperature of the first temperature rise wire according to the initial temperature rise.

[0029] On the other hand, in the step S2, the generation method of the first dynamic long-term current-carrying capacity includes:

[0030] ;

[0031] In the formula, is the first dynamic long-term current-carrying capacity;

[0032] represents the radiative heat dissipation per unit length of the wire when the wire is at the current operating current and the wire temperature ;

[0033] represents the convective heat dissipation per unit length of the wire when the wire is at the current operating current and the wire temperature ;

[0034] represents the solar heat absorption per unit length of the wire when the wire is at the current operating current and the wire temperature ;

[0035] is the wire temperature limit.

[0036] On the other hand, the step S3 includes:

[0037] Step S31: generating the current carrying capacity value range according to the first dynamic long-term current carrying capacity;

[0038] Step S32: Searching within the current carrying capacity value range according to a preset step size to obtain a plurality of feasible current carrying capacities to be predicted;

[0039] Step S33: generating the second temperature-rise conductor temperature according to the current-carrying capacity to be predicted.

[0040] On the other hand, in step S33, the method for generating the second temperature-rise conductor temperature includes:

[0041] ;

[0042] Where, is the second temperature-rise conductor temperature;

[0043] is the conductor temperature before temperature rise;

[0044] is the current ambient temperature rise;

[0045] Indicates the current running on the conductor I K and conductor temperature The heat generated by the AC resistance per unit length of the wire;

[0046] Indicates the current running on the conductor I K and conductor temperature When the conductor absorbs sunlight per unit length;

[0047] Indicates the current running on the conductor I K and conductor temperature Convection heat dissipation per unit length of the conductor;

[0048] Indicates the current running on the conductor I K and conductor temperature The radiation heat dissipation per unit length of the wire.

[0049] On the other hand, in step S4, the method for generating the second dynamic long-term current carrying capacity includes:

[0050] ;

[0051] Where, is the second dynamic long-term current carrying capacity;

[0052] represents the current operating current of the wire I K and the wire temperature T lim the radiative heat dissipation per unit length of the wire at that time;

[0053] represents the current operating current of the wire I K and the wire temperature T lim the convective heat dissipation per unit length of the wire at that time;

[0054] represents the current operating current of the wire I K and the wire temperature T lim the solar heat absorption per unit length of the wire at that time.

[0055] A memory includes computer instructions that, when executed by a computer device, perform the above-mentioned transmission line dynamic load management method.

[0056] The above technical solution has the following advantages or beneficial effects:

[0057] Aiming at the problems of prediction lag in the existing dynamic rating technology, insufficient accuracy of short-term meteorological prediction models, poor local applicability, and insufficient response to load changes, in this solution, a regulation process based on real-time load feedback is introduced. By pre-estimating the temperature rise and current-carrying capacity after a predetermined time period for each line to be evaluated, the available current-carrying capacity range of the line is determined. Then, a feasible current-carrying capacity parameter is searched within this range and the corresponding temperature rise situation is estimated, so that the error between the finally estimated temperature rise and current-carrying capacity is small, avoiding the problem of poor accuracy in the existing estimation scheme that uses the current temperature for estimation, and realizing the accurate control of the line. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Referring to the accompanying drawings, the embodiments of the present invention are described more fully. However, the accompanying drawings are only for illustration and explanation and do not constitute a limitation on the scope of the present invention.

[0059] Figure 1 is the overall schematic diagram of the embodiment of the present invention;

[0060] Figure 2 is the schematic diagram of step S1 in the embodiment of the present invention;

[0061] Figure 3 is the schematic diagram of step S3 in the embodiment of the present invention;

[0062] Figure 4 This is a schematic diagram of the dynamic current-carrying capacity regulation effect in the embodiments of the present invention. Detailed implementation manners

[0063] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0064] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments may be combined with each other.

[0065] Next, the present invention will be further described in conjunction with the accompanying drawings and specific embodiments, but it is not limited to the present invention.

[0066] The present invention includes:

[0067] A method for dynamic load management of a transmission line based on load feedback regulation, as Figure 1 shown, includes:

[0068] Step S1: Construct a state vector for the line to be evaluated and estimate the temperature of the first temperature-rise conductor after a predetermined time period;

[0069] Step S2: Estimate the first dynamic long-term current-carrying capacity based on the temperature of the first temperature-rise conductor;

[0070] Step S3: Determine the range of the current-carrying capacity of the second dynamic long-term current-carrying capacity for the line to be evaluated according to the first dynamic long-term current-carrying capacity, and estimate the temperature of the second temperature-rise conductor after the line to be evaluated has operated for a predetermined time according to the range of the current-carrying capacity;

[0071] Step S4: Calculate the second dynamic long-term current-carrying capacity at the temperature of the second temperature-rise conductor;

[0072] Step S5: Determine whether the error between the second dynamic long-term current-carrying capacity and the predicted current-carrying capacity in the range of the current-carrying capacity is within the error setting range;

[0073] If so, output the second dynamic long-term current-carrying capacity as the actual dynamic current-carrying capacity;

[0074] If not, increase the predetermined time by a preset step size, and then return to Step S3.

[0075] Specifically, aiming at the problems of prediction lag in the existing dynamic rating technology, insufficient accuracy of short-term meteorological prediction models, poor local applicability, and insufficient response to load changes, in this solution, a regulation process based on real-time load feedback is introduced. Especially in the calculation process, after estimating the range of ampacity values, the second temperature rise conductor temperature that the line to be evaluated may reach after operating for a predetermined time is first estimated according to the ampacity value range. Based on the second temperature rise conductor temperature obtained from this estimation, the line capacity at this temperature is then evaluated to obtain the second dynamic long-term ampacity, avoiding the inaccurate problem caused by the evaluation scheme in the existing technology that evaluates according to the temperature in the initial state;

[0076] Furthermore, to ensure the accuracy of the estimation, multiple ampacities to be predicted are also determined within the predetermined range of ampacity values. Whether the prediction process is accurate is determined according to the error magnitude between the second dynamic long-term ampacity and the ampacities to be predicted. If it is inaccurate, it may be that the line has not yet entered a steady state, and the prediction time period is extended to improve the measurement accuracy.

[0077] Specifically, for each line to be evaluated, a state vector is constructed at the initial stage of the evaluation As the initial value of the system, this state vector corresponds to the various states of the line to be evaluated. For example, is t the ambient temperature at = 0, in °C; is t the conductor temperature at = 0, in °C; is t the solar radiation intensity at = 0, in W / m 2 ; is t the conductor current at = 0, in A; is t the wind speed at = 0, in m / s.[[ID=3P]]

[0078] Based on the above state vector, the conductor temperature rise situation of the line to be evaluated and the first temperature rise conductor temperature after a period of time can be calculated.

[0079] For this first temperature rise conductor temperature, the line capacity can be evaluated to determine the first dynamic long-term ampacity at which the line can operate in a steady state under the current conditions.

[0080] Then, taking the static rated ampacity of the conductor and the first dynamic long-term ampacity as the upper and lower boundaries of the search range, a search is performed according to a preset step size to obtain multiple ampacities to be predicted.

[0081] For multiple ampacities to be predicted, the temperature change situation corresponding to the respective ampacities can be simulated based on the above state vector as the second temperature rise conductor temperature;

[0082] Based on the second temperature rise of the wire, calculate the second dynamic long-term current-carrying capacity that the wire can operate for a long time when it reaches a steady state at this temperature.

[0083] Generally speaking, the second dynamic long-term current-carrying capacity and the predicted current-carrying capacity should have a small error. Then, select the predicted current-carrying capacity whose error range meets the requirements for output, and use it as the actual dynamic long-term current-carrying capacity in the actual control process.

[0084] In one embodiment, in step S1, the method for generating the first temperature rise of the wire includes:

[0085] ;

[0086] In the formula, is the first temperature rise of the wire;

[0087] is t the wire temperature at t = 0;

[0088] is the initial temperature rise under the current operating current ;

[0089] is the heat generated by the AC resistance per unit length of the wire under the initial conditions;

[0090] is the solar heat absorption per unit length of the wire under the initial conditions;

[0091] is the convective heat dissipation per unit length of the wire under the initial conditions;

[0092] is the radiative heat dissipation per unit length of the wire under the initial conditions;

[0093] dt is the time increment, dt =Δ t .

[0094] Specifically, to effectively estimate the wire temperature rise under the initial conditions, in this embodiment, first calculate the initial temperature rise by combining various environmental parameters, and then calculate the first temperature rise of the wire by combining the initial temperature.

[0095] Among them, the calculation process of the initial temperature rise is mainly related to four environmental parameters, including line resistance heating, solar heat absorption, convective heat dissipation, and radiative heat dissipation.

[0096] Specifically:

[0097] (1) , , R 20 is the DC resistance value at a wire temperature of 20°C, unit Ω / m; α 20 is the temperature coefficient of the wire material at 20°C, unit 1 / °C; k 1 is the skin effect coefficient. When the cross-sectional area of the wire is less than or equal to 400 mm 2 , it is recommended to take 0.0025. When it is greater than 400 mm 2 , it is recommended to take 0.01; k 2 is the comprehensive influence coefficient of the proximity effect and hysteresis loss.

[0098] (2) , ε is the heat absorption coefficient of the wire surface. For shiny new wires, it is 0.35 - 0.46. For old wires or wires coated with black preservatives, it is 0.90 - 0.95.

[0099] (3) , μ 0 represents the kinematic viscosity of the air layer on the wire surface when the wire temperature is , unit m 2 / s; λ 0 represents the heat transfer coefficient of the air layer on the wire surface when the wire temperature is , unit W / m·°C; D is the wire diameter, unit m.

[0100]

[0101]

[0102] (4) , π is pi; s is the Stefan - Boltzmann constant, 5.67×10 -8 W·m -2 ·K -4 , σ is the radiation coefficient of the wire surface. For shiny new wires, it is 0.23 - 0.43. For old wires or wires coated with black preservatives, it is 0.90 - 0.95.

[0103] (5)Taking ACSR as an example, , m 、 m stl 、 m al are the mass per unit length of steel and aluminum, steel, and aluminum respectively, unit kg / m; c p, c stl , c al Specific heat capacities of steel and aluminum, steel, and aluminum respectively, in units of J / (kg·℃); T line is the wire temperature, in units of ℃; t is the time, in units of s.

[0104] Based on the above process, as Figure 2 shown, step S1 includes:

[0105] Step S11: Collect heat parameter information for the line to be evaluated;

[0106] Step S12: Generate an initial temperature rise based on the heat parameter information;

[0107] Step S13: Generate a first temperature-rise wire temperature based on the initial temperature rise.

[0108] In one embodiment, in step S2, the method for generating the first dynamic long-term current-carrying capacity includes:

[0109] ;

[0110] In the formula, is the first dynamic long-term current-carrying capacity;

[0111] represents the radiation heat dissipation per unit length of the wire at the current operating current and the wire temperature ;

[0112] represents the convective heat dissipation per unit length of the wire at the current operating current and the wire temperature ;

[0113] represents the solar radiation heat absorption per unit length of the wire at the current operating current and the wire temperature ;

[0114] is the wire temperature limit.

[0115] Specifically, after calculating the first temperature-rise wire temperature, the first dynamic long-term current-carrying capacity that can operate for a long time at the corresponding temperature can be calculated based on the above process.

[0116] Among them, represents the radiation heat dissipation per unit length of the wire at the current operating current and the wire temperature T limThe radiation heat dissipation per unit length of the wire at time, unit: J; Indicates the wire at the current operating current And the wire temperature T lim The convective heat dissipation per unit length of the wire at time, unit: J; Indicates the wire at the current operating current And the wire temperature T lim The solar radiation heat absorption per unit length of the wire at time, unit: J.

[0117] (1)

[0118] (2) , μ m Indicates that the wire temperature is T lim The kinematic viscosity of the air layer on the wire surface when the wire temperature is, unit: m 2 / s; λ m Indicates that the wire temperature is T lim The heat transfer coefficient of the air layer on the wire surface when the wire temperature is, unit: W / m·°C.

[0119]

[0120]

[0121] (3) =

[0122] (4) , T lim Is the wire temperature limit value, unit: °C.

[0123] In one embodiment, as Figure 3 Shown, step S3 includes:

[0124] Step S31: Generate a range of current-carrying capacity values according to the first dynamic long-term current-carrying capacity;

[0125] Step S32: In the range of current-carrying capacity values, search according to a preset step size to obtain multiple feasible predicted current-carrying capacities;

[0126] Step S33: Generate the second temperature rise wire temperature according to the predicted current-carrying capacity respectively.

[0127] Specifically, after determining the first dynamic long-term current-carrying capacity, the static rated current-carrying capacity of the wire and the first dynamic long-term current-carrying capacity can be used as the upper and lower boundaries of the search range, and search according to a preset step size to obtain multiple predicted current-carrying capacities.

[0128] For multiple current-carrying capacities to be predicted, the temperature change under the corresponding current-carrying capacity can be respectively simulated based on the above state vectors as the second temperature rise conductor temperature.

[0129] In one embodiment, in step S33, the method for generating the second temperature rise conductor temperature includes:

[0130] ;

[0131] In the formula, is the second temperature rise conductor temperature;

[0132] is the conductor temperature before temperature rise;

[0133] is the current ambient temperature rise;

[0134] represents the heat generated by the AC resistance per unit length of the conductor at the current operating current I K and the conductor temperature ;

[0135] represents the solar heat absorption per unit length of the conductor at the current operating current I K and the conductor temperature ;

[0136] represents the convective heat dissipation per unit length of the conductor at the current operating current I K and the conductor temperature ;

[0137] represents the radiative heat dissipation per unit length of the conductor at the current operating current I K and the conductor temperature ;

[0138] Among them, the dynamic current-carrying capacity that can still operate for a long time in the environment after temperature rise at the moment t K is defined as the current-carrying capacity to be predicted, denoted as I K , and the value range I K ∈ I R , I M , unit A; Δ I = 1; IR is the static rated current-carrying capacity of the wire, in A. And a step size Δ is set. I Traverse I K Substitute the current running current as the current ambient temperature into the temperature rise model to calculate the temperature rise under the current environment. and i the wire temperature at the +1 moment:

[0139] Among them, the calculation methods of the above environmental heat quantities include:

[0140] (1) ,

[0141] (2) =

[0142] (3) , μ i represents the kinematic viscosity of the air layer on the wire surface when the wire temperature is , in units of m 2 / s; λ i represents the heat transfer coefficient of the air layer on the wire surface when the wire temperature is , in units of W / m·°C.

[0143]

[0144]

[0145] (4)

[0146] Preferably, t K The value range of I K should at least reserve enough time for the dispatcher to plan the line operation in advance and at most should not exceed the time for the wire to reach a steady state; the value range of I should preferably take a fixed value within the range of 1 to 10 to ensure sufficient dense values within the current range.

[0147] Typically, t K the value range of t K ∈[30, 240].

[0148] In one embodiment, in step S4, the method for generating the second dynamic long-term current-carrying capacity includes:

[0149] ;

[0150] Wherein, is the second dynamic long-term current-carrying capacity;

[0151] represents the radiation heat dissipation per unit length of the wire at the current operating current I K and the wire temperature T lim at the time;

[0152] represents the convective heat dissipation per unit length of the wire at the current operating current I K and the wire temperature T lim at the time;

[0153] represents the solar radiation heat absorption per unit length of the wire at the current operating current I K and the wire temperature T lim at the time;

[0154] Among them, (1) =

[0155] (2)

[0156] (3) =

[0157] represents the radiation heat dissipation per unit length of the wire when the current operating current is I K and the wire temperature T lim at the time; represents the radiation heat dissipation per unit length of the wire at the current operating current and the wire temperature T lim at the time, in units of J;

[0158] ;

[0159] μ m represents the kinematic viscosity of the air layer on the wire surface when the wire temperature is T lim at the time, in units of m 2 / s; λ m represents the wire temperature asT lim The heat transfer coefficient of the air layer on the wire surface, with the unit of W / m·℃.

[0160]

[0161]

[0162] , ε is the heat absorption coefficient of the wire surface, which is 0.35 - 0.46 for shiny new wires and 0.90 - 0.95 for old wires or wires with black preservatives.

[0163] is t the solar radiation intensity at the moment of t = 0.

[0164] In one embodiment, in step S5, the actual dynamic long-term current-carrying capacity is determined according to the error between the second dynamic long-term current-carrying capacity and the predicted current-carrying capacity.

[0165] Specifically, to achieve a better estimation effect, in this embodiment, for each generated second dynamic long-term current-carrying capacity, the error between it and the predicted current-carrying capacity is calculated respectively, that is , where is the second dynamic long-term current-carrying capacity, is the predicted current-carrying capacity.

[0166] When , it is the finally calculated dynamic long-term current-carrying capacity; otherwise, another second dynamic long-term current-carrying capacity is calculated.

[0167] Generally speaking δ should be taken as a natural number between 0 and 10 as small as possible to reduce the calculated error, but should not be too small to increase unnecessary computational workload, and can be appropriately adjusted according to the rated current-carrying capacity of the wire δ the value of δ = 1.

[0168] The control result achieved based on the above intelligent adjustment method is as Figure 4 shown. The ordinate corresponds to the comparison of dynamic current-carrying capacity, and the abscissa is the date. It can be seen that the adjustment process achieved based on this solution is smoother and more in line with the actual situation.

[0169] A memory includes computer instructions. When a computer device executes the computer instructions, the above-mentioned transmission line dynamic load management method is executed.

[0170] Those of ordinary skill in the art will understand that various aspects of the present invention, or possible implementations of various aspects, can be embodied as a system, a method, or a computer program product. Therefore, various aspects of the present invention, or possible implementations of various aspects, can take the form of a complete hardware embodiment, a complete software embodiment (including firmware, resident software, etc.), or an embodiment combining software and hardware aspects, all of which are collectively referred to herein as "circuits", "modules", or "systems" here. In addition, various aspects of the present invention, or possible implementations of various aspects, can take the form of a computer program product, which refers to computer instructions stored in a memory.

[0171] The memory can be a computer-readable signal medium or a computer-readable storage medium. The computer-readable storage medium includes, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or apparatuses, or any suitable combination of the foregoing, such as random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable read-only memory (CD-ROM).

[0172] The processor in the computer reads the computer instructions stored in the memory, enabling the processor to perform the functional actions specified in each step, or combination of steps, in the flowchart; generating means for performing the functional actions specified in each block, or combination of blocks, in the block diagram.

[0173] It should be understood that the processor in the computer can be understood as being implemented by one or more application-specific integrated circuits (ASICs), DSPs, programmable logic devices (PLDs), complex programmable logic devices (CPLDs), field-programmable gate arrays (FPGAs), general-purpose processors, controllers, microcontrollers (MCUs), microprocessors, or other electronic components, for executing the aforementioned computer instructions.

[0174] The computer instructions can be executed entirely on the user's local computer, partially on the user's local computer, as a separate software package, partially on the user's local computer and partially on a remote computer, or entirely on a remote computer or server. It should also be noted that in some alternative embodiments, the functions noted in each step of the flowchart, or each block of the block diagram, may not occur in the order noted in the figure. For example, depending on the functions involved, two consecutive steps, or two blocks shown in succession, may actually be executed substantially simultaneously, or these blocks may sometimes be executed in the reverse order.

[0175] Of course, in actual applications, each component in a computer system is coupled together through a bus system. It can be understood that the bus system is used to achieve connection and communication between these components. In addition to a data bus, the bus system also includes a power bus, a control bus, and a status signal bus.

[0176] The above are only preferred embodiments of the present invention, and do not limit the implementation manners and protection scope of the present invention. For those skilled in the art, it should be realized that all equivalent replacements and obvious changes made by using the description and illustrations of the present invention should be included in the protection scope of the present invention.

Claims

1. A dynamic load management method for transmission lines based on load feedback regulation, characterized in that, Including: Step S1: Construct a state vector for the line to be evaluated and estimate the first temperature rise of the conductor after a predetermined period of time; Step S2: Estimate the first dynamic long-term current-carrying capacity based on the first temperature rise of the conductor; Step S3: Determine the range of the current-carrying capacity of the second dynamic long-term current-carrying capacity for the line to be evaluated according to the first dynamic long-term current-carrying capacity, and estimate the second temperature rise of the conductor after the line to be evaluated has operated for a predetermined time according to the range of the current-carrying capacity; The said Step S3 includes: Step S31: Generate the range of the current-carrying capacity according to the first dynamic long-term current-carrying capacity; Step S32: Search within the range of the current-carrying capacity according to a preset step size to obtain a plurality of feasible predicted current-carrying capacities to be predicted; Step S33: Generate the second temperature rise of the conductor respectively according to the predicted current-carrying capacities to be predicted; Step S4: Calculate the second dynamic long-term current-carrying capacity at the second temperature rise of the conductor according to the second temperature rise of the conductor; Step S5: Determine whether the error between the second dynamic long-term current-carrying capacity and the predicted current-carrying capacity within the range of the current-carrying capacity is within the error setting range; If so, output the second dynamic long-term current-carrying capacity as the actual dynamic current-carrying capacity; If not, increase the predetermined time according to the preset step size, and then return to the said Step S3.

2. The dynamic load management method for a transmission line according to claim 1, wherein In the said Step S1, the method for generating the first temperature rise of the conductor includes: ； In the formula, is the temperature of the first temperature-rise wire; For t = wire temperature at time 0; is the initial temperature rise at the current operating current ; is the heat generated by the AC resistance per unit length of the wire under the initial conditions; is the solar heat absorption per unit length of the wire under initial conditions; is the convective heat dissipation per unit length of the wire under the initial condition; is the radiative heat dissipation per unit length of the wire under the initial condition; is the product of the equivalent mass per unit length of the wire and the specific heat capacity; dt is the time increment, dt = Δ t .

3. The transmission line dynamic load management method according to claim 2, characterized in that The said Step S1 includes: Step S11: Collect heat parameter information for the line to be evaluated; Step S12: Generate an initial temperature rise according to the heat parameter information; Step S13: Generate the first temperature rise of the conductor according to the initial temperature rise.

4. The dynamic load management method for a transmission line according to claim 1, wherein, In the said Step S2, the method for generating the first dynamic long-term current-carrying capacity includes: ； In the formula, is the first dynamic long-term current-carrying capacity; Indicates the radiation heat dissipation per unit length of the wire when the wire is under the current of the current operation and the wire temperature is ; Indicates the current operating current of the wire and the convective heat dissipation per unit length of the wire when the wire temperature is ; Indicates the current operating current of the wire And the wire temperature is The solar heat absorption per unit length of the wire at this time; is the conductor temperature limit; R 20 is the DC resistance value at a wire temperature of 20 °C, unit: Ω / m; α 20 The temperature coefficient of the wire material at 20 °C; k 1 is the skin effect coefficient; k 2 is the comprehensive influence coefficient of the proximity effect and the hysteresis loss.

5. The transmission line dynamic load management method according to claim 1, characterized in that In the said Step S33, the method for generating the second temperature rise of the conductor includes: ； In the formula, is the temperature of the second temperature-rise wire; is the wire temperature before temperature rise; is the temperature rise of the current environment; Indicates the current flowing through the wire under current operation I K and the wire temperature the heat generated by the AC resistance per unit length of the wire at that time; Indicates the current operating current of the wire I K and the wire temperature The solar heat absorption per unit length of the wire at that time; Indicates the current operating current of the wire I K and the wire temperature Convective heat dissipation per unit length of the wire at that time; Indicates the current operating current of the wire I K and the wire temperature radiative heat dissipation per unit length of the wire at that time; It is the product of the equivalent mass per unit length of the wire and the specific heat capacity.

6. The dynamic load management method for a transmission line according to claim 4, wherein In the said Step S4, the method for generating the second dynamic long-term current-carrying capacity includes: ； In the formula, is the second dynamic long-term current-carrying capacity; Indicates the current operating current of the wire I K and the wire temperature is T lim the radiation heat dissipation per unit length of the wire at that time; Indicates the current operating current of the wire I K and the wire temperature is T lim the convective heat dissipation per unit length of the wire at that time; Indicates the current operating current of the wire I K and the wire temperature is T lim the solar heat absorption per unit length of the wire at this time; ； is the wire temperature limit value; R 20 It is the DC resistance value at a wire temperature of 20 °C, with the unit of Ω / m; α 20 is the temperature coefficient of the wire material at 20 °C; k 1 is the skin effect coefficient; k 2 is the comprehensive influence coefficient of the proximity effect and the hysteresis loss.

7. A memory, comprising computer instructions, characterized in that, When the computer device executes the said computer instructions, it executes the transmission line dynamic load management method according to any one of claims 1-6.

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