CN113591397B - Power frequency electric field control method and system for alternating current overhead transmission line - Google Patents
Power frequency electric field control method and system for alternating current overhead transmission line Download PDFInfo
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Abstract
The invention provides a method and a system for controlling a power frequency electric field of an alternating current overhead transmission line, wherein the method comprises the following steps: establishing a three-dimensional power frequency electric field calculation model of the alternating current transmission line according to a catenary equation of the overhead transmission line; erecting a shielding wire scheme at a proper position below an alternating current transmission line, substituting the shielding wire scheme into a three-dimensional power frequency electric field calculation model of the alternating current transmission line, and calculating the environmental sensitive target power frequency electric field strength of the shielding wire scheme by using an improved simulated charge method; and setting a power frequency electric field at an environment sensitive target as an objective function to be optimized by adopting a genetic algorithm, solving the minimum value of the objective function, and taking the objective function as a solved fitness function. The method can organically combine environmental benefit and economic benefit, and find an optimal scheme for comprehensive engineering cost and shielding effect, and provides reference for engineering design and a power frequency electric field control scheme of an alternating current overhead transmission line.
Description
Technical Field
The invention relates to the technical field of electromagnetic pollution control of alternating-current transmission lines, in particular to a method and a system for controlling a power frequency electric field of an alternating-current overhead transmission line.
Background
Along with the acceleration of social economic development and urban process, in order to meet the increasing electricity load demand, the electricity transmission and transformation construction scale steadily increases in recent years, various high-voltage transmission lines are more and more close to public activity areas, inevitably approach residents houses, electromagnetic influence is generated on residents nearby the transmission lines, environmental complaints and disputes caused by the transmission lines are increasingly increased in recent years, and the phenomenon that the power frequency electric field exceeds the standard appears in part of environmental sensitive targets adjacent to the transmission lines, so that the method has become a focus problem of attention of ecological environment protection departments and electric power departments.
When the power transmission line is not built and is close to an environment sensitive point, comprehensive measures such as increasing the height of a pole tower, optimizing the phase sequence arrangement, reducing the number of splits, changing the distance between wires, keeping away from the environment sensitive point and the like can be adopted in the design stage, so that the electromagnetic environment at an environment sensitive target can meet the public exposure control limit requirement in electromagnetic environment control limit (GB 8702-2014). However, for the phenomenon that the electromagnetic environment exceeds standard of the built power transmission line, the measures are difficult to implement, and the measures such as shielding wires can be adopted to avoid power failure and high cost investment caused by modifying the existing line or reduce social problems caused by disassembly and the like.
Therefore, for the problem of exceeding the power frequency electric field under the transmission line, an optimal control scheme is needed to be provided, and a basis is provided for engineering designers and the control of the power frequency electric field of the alternating current overhead transmission line.
Disclosure of Invention
The invention provides a method and a system for controlling a power frequency electric field of an alternating current overhead transmission line in order to solve the problem of exceeding the standard of the power frequency electric field of the alternating current transmission line. The method can organically combine environmental benefit and economic benefit, and find an optimal scheme for comprehensive engineering cost and shielding effect, and provides reference for engineering design and a power frequency electric field control scheme of an alternating current overhead transmission line.
In order to achieve the above purpose, the invention adopts the following technical scheme:
a power frequency electric field control method of an alternating current overhead transmission line comprises the following steps:
establishing a three-dimensional power frequency electric field calculation model of the alternating current transmission line according to a catenary equation of the overhead transmission line;
erecting a shielding wire scheme at a proper position below an alternating current transmission line, substituting the shielding wire scheme into a three-dimensional power frequency electric field calculation model of the alternating current transmission line, and calculating the environmental sensitive target power frequency electric field strength of the shielding wire scheme by using an improved simulated charge method;
and setting a power frequency electric field at an environment sensitive target as an objective function to be optimized by adopting a genetic algorithm, solving the minimum value of the objective function, and taking the objective function as a solved fitness function.
The catenary equation of the overhead transmission line is as follows:
wherein z (x) is the ground height of a certain point of the overhead transmission line; sigma (sigma) 0 Is the horizontal stress of the wire; gamma is the specific load of the wire; l is a horizontal span; h is the height difference; h is the vertical distance between the hanging point and the ground; f (f) x Is a wire sag; l (L) OA 、l OB Is the horizontal distance from the lowest point of the wire to the suspension point.
As a further improvement of the invention, the method for calculating the environmental sensitive target power frequency electric field strength of the shielded wire scheme by using the improved simulated charge method specifically comprises the following steps:
let the density be τ m Is uniformly distributed in the nth wire m Segments, which generate potentials at spatial Q points (x, y, z)
Is that
Wherein ε 0 Is vacuum dielectric constant; r is (r) m 、r m ' is the distance from the source point and its mirror image to the field point;
the potential coefficient is
Thereby obtaining the wire l m Potential coefficient generated by the segment at point Q
Wherein x is m 、y m Respectively in the nth wire m The x, y axis coordinates of the segment; ρ m 、ρ m ' is the distance from the source point to the Q point and mirror image thereof, respectively;
the potential generated by the transmission line at the space Q point is the result of the combined action of all line charges, and then the charge density is obtained according to the known potential of the matching point on the surface of the lead
τ＝P -1 U
Where τ is the charge density column vector; p is a potential coefficient matrix; u is the voltage column vector of each wire;
thereby obtaining the electric field intensity vector of the Q point
In the method, in the process of the invention,
is the n-th wire inner l m The potential generated by the segment; e (E) x 、E y 、E z X, y, z3 directional components of the electric field respectively; e, e x 、e y 、e z The unit vectors are respectively in x, y and z3 directions; n is the phase line number; n is n 0 The number of overhead ground wires is the number;
the effective value of the electric field intensity at the Q point is
As a further improvement of the invention, the power frequency electric field at the environment sensitive target is set as an objective function to be optimized, and the method specifically comprises the following steps:
wherein, f (X) -an objective function; e, the power frequency electric field intensity; x-optimizing variable solution vector; d, the outer diameter of the shielding wire; l is the length of the shielding wire; p (P) x -the lateral position of the shielding wire in the system; p (P) y -the longitudinal position of the shielding wire in the system; g i (X) -the ith constraint; n-constraint number;
and combining engineering practice to give a certain value range to each variable.
As a further improvement of the present invention, the genetic algorithm specifically includes:
randomly generating an initial population pop (t), wherein the evolution algebra t=1, the number of individuals is N, and each individual consists of the gene codes of chromosomes;
calculating fitness f of each individual pop (t) in the population according to the following formula (a) i And judges whether the optimization criteria are met. If yes, outputting the optimal individual and the optimal solution represented by the optimal individual, and ending the calculation; otherwise, the next step is carried out;
f i ＝fitness(pop i (t)) (a)
selecting regenerated individuals from the population pop (t) according to the probability distribution of the following formula (b), wherein the individuals with high fitness are selected with high probability, and the individuals with low fitness are possibly eliminated, so as to form a new population (c):
newpop(t+1)＝{pop j (t)|j＝1,2,...,N|} (c)
generating a new population cross (t+1) according to the cross probability Pc and a certain cross method;
according to the mutation probability Pm and a certain mutation method, a new population mutpop (t+1) is generated.
The evolution algebra t=t+1, generates a new generation population pop (t) =mutpop (t), and returns to calculate the fitness f of each individual pop (t) in the population i 。
As a further improvement of the invention, the initial population is subjected to initial optimization data, wherein the initial optimization data comprises the outer diameter of the shielded wire, the length of the shielded wire, the transverse position of the shielded wire and the longitudinal position of the shielded wire.
As a further improvement of the invention, the convergence criterion of the genetic algorithm is that the two consecutive optimal results are the same, namely the iteration number result, and the optimal scheme is output.
An ac overhead transmission line power frequency electric field control system comprising:
the model building module is used for building a three-dimensional power frequency electric field calculation model of the alternating current transmission line according to a catenary equation of the overhead transmission line;
the electric field calculation module is used for erecting a shielding wire scheme at a proper position below the alternating current transmission line, substituting the shielding wire scheme into a three-dimensional power frequency electric field calculation model of the alternating current transmission line, and calculating the environmental sensitive target power frequency electric field strength of the shielding wire scheme by using an improved simulated charge method;
and the genetic algorithm module is used for adopting a genetic algorithm, setting a power frequency electric field at an environment sensitive target as an objective function to be optimized, solving the minimum value of the objective function, and taking the objective function as a solved fitness function.
An electronic device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, the processor implementing the steps of the ac overhead transmission line power frequency electric field control method when executing the computer program.
A computer readable storage medium storing a computer program which when executed by a processor performs the steps of the ac overhead transmission line power frequency electric field control method.
The beneficial effects of the invention are as follows:
according to the method, a three-dimensional power frequency electric field calculation model of the alternating current transmission line is firstly established according to a catenary equation of the overhead transmission line, then three-dimensional power frequency electric field distribution of the alternating current transmission line is calculated based on an improved simulated charge method, finally, a power frequency electric field at an environment sensitive target is set as an objective function to be optimized by applying the integral optimization design concept of a genetic algorithm, optimization is carried out in the whole solution space at the same time, and an optimal scheme for shielding line erection is found out. The optimization method can perform optimization in the whole solution space at the same time, has global optimal searching capability, and can find out the scheme of the optimal shielding effect in the shortest time. The optimization method can also bring the construction cost into an optimization scheme, and under the condition of meeting the standard limit requirement of the power frequency electric field, the scheme with the lowest construction cost can organically combine the environmental benefit and the economic benefit, and the comprehensive engineering cost and the shielding effect seek an optimal scheme, thereby providing reference for engineering design and the power frequency electric field control scheme of the alternating current overhead transmission line.
Drawings
Fig. 1 is a schematic flow chart of a method for controlling a power frequency electric field of an ac overhead transmission line according to a preferred embodiment of the present invention.
Fig. 2 is a catenary schematic of the present invention.
Wherein z (x) is the ground height of a certain point of the overhead transmission line, and m; sigma (sigma) 0 Is the horizontal stress (i.e. the stress at the lowest point) of the wire, N/mm 2 The method comprises the steps of carrying out a first treatment on the surface of the Gamma is the specific load (i.e. the load per unit section per unit length) of the wire, N/(m.mm) 2 ) The method comprises the steps of carrying out a first treatment on the surface of the l is a horizontal span (horizontal distance between two suspension points), m; h is the height difference (the vertical distance between two suspension points), m; h is the vertical distance between the hanging point and the ground, and m; f (f) x Is a wire sag; l (L) OA 、l OB Is the horizontal distance from the lowest point of the wire to the suspension point.
Fig. 3 is a system block diagram of a method for controlling and optimizing a power frequency electric field of an ac overhead transmission line according to the present invention.
Fig. 4 is a schematic structural diagram of a power frequency electric field control system of an ac overhead transmission line according to a preferred embodiment of the present invention.
Fig. 5 is a schematic structural view of an electronic device according to a preferred embodiment of the present invention.
Detailed Description
The invention will be described in detail below with reference to the drawings in connection with embodiments. It should be noted that, in the case of no conflict, the embodiments and features in the embodiments may be combined with each other.
The following detailed description is exemplary and is intended to provide further details of the invention. Unless defined otherwise, all technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments in accordance with the invention.
As shown in fig. 1, a first object of the present invention is to provide a method for controlling a power frequency electric field of an ac overhead transmission line, which includes the following steps:
establishing a three-dimensional power frequency electric field calculation model of the alternating current transmission line according to a catenary equation of the overhead transmission line;
erecting a shielding wire scheme at a proper position below an alternating current transmission line, substituting the shielding wire scheme into a three-dimensional power frequency electric field calculation model of the alternating current transmission line, and calculating the environmental sensitive target power frequency electric field strength of the shielding wire scheme by using an improved simulated charge method;
and setting a power frequency electric field at an environment sensitive target as an objective function to be optimized by adopting a genetic algorithm, solving the minimum value of the objective function, and taking the objective function as a solved fitness function.
The improved simulated charge method includes the steps of firstly, dividing an overhead transmission line wire, a ground wire and a shielding wire into a plurality of finite length line segments, carrying out mirror image processing on the ground, solving potential coefficients generated by each finite length line segment at each matching point, taking known potentials as boundary conditions, and establishing an equation:
wherein P is a potential coefficient matrix; τ is the analog charge density column vector to be solved;
is the matching point potential column vector.
The power frequency electric field intensity of any space to-be-solved point can be deduced through dividing the overhead transmission line wire, the ground wire and the shielding wire and solving the analog charges.
Specifically, a three-dimensional power frequency electric field calculation model of the alternating current transmission line is established according to a catenary equation of the overhead transmission line. And calculating the three-dimensional power frequency electric field of the alternating current transmission line by adopting an improved simulated charge method. The power frequency electric field of the alternating current overhead transmission line is controlled by arranging a shielding wire, and the intensity of the environment sensitive target power frequency electric field after the shielding wire is arranged, namely the shielding effect, is calculated.
And introducing a genetic algorithm, setting a power frequency electric field at an environment sensitive target as an objective function to be optimized, solving the minimum value of the optimization function, and taking the objective function as a solved fitness function. And combining engineering practice, performing range constraint on each optimization variable.
Based on the genetic algorithm overall optimization design concept, initializing optimization data, including the outer diameter of a shielding wire, the length of the shielding wire, the transverse position of the shielding wire, the longitudinal position of the shielding wire and the like, and finding out an optimal scheme of the shielding wire which meets the program ending condition through a series of fitness calculation, selection, crossing, variation and the like.
When the three-dimensional power frequency electric field of the alternating current transmission line is calculated based on the improved simulated charge method, the lightning conductor and the shielding wire are well grounded, and the ground voltage can be regarded as the ground voltage, namely zero potential.
The method of the invention is described in detail below with reference to the attached drawing:
and establishing a three-dimensional power frequency electric field calculation model of the alternating current transmission line according to the catenary equation of the overhead transmission line.
According to the stress balance condition, the catenary equation of the overhead transmission line shown in fig. 2 can be obtained:
wherein z (x) is the ground height of a certain point of the overhead transmission line, and m; sigma (sigma) 0 Is the horizontal stress (i.e. the stress at the lowest point) of the wire, N/mm 2 The method comprises the steps of carrying out a first treatment on the surface of the Gamma is the specific load (i.e. the load per unit section per unit length) of the wire, N/(m.mm) 2 ) The method comprises the steps of carrying out a first treatment on the surface of the l is a horizontal span (horizontal distance between two suspension points), m; h is the height difference (the vertical distance between two suspension points), m; h is the vertical distance between the hanging point and the ground, and m; f (f) x Is a wire sag; l (L) OA 、l OB Is the horizontal distance from the lowest point of the wire to the suspension point.
Calculating a three-dimensional power frequency electric field of the alternating current transmission line by adopting a charge simulating method:
let the density be τ m Is uniformly distributed in the nth wire m Segments, which generate potentials at spatial Q points (x, y, z)
Is that
Wherein ε 0 Is vacuum dielectric constant; r is (r) m 、r m ' is the distance of the source point and its mirror image to the field point, respectively.
The potential coefficient is
Substituting formula (2) into formula (3) to obtain wire l m Potential coefficient generated by the segment at point Q
Wherein x is m 、y m Respectively in the nth wire m The x, y axis coordinates of the segment; ρ m 、ρ m ' is the source point and its mirror distance to the Q point, respectively.
The potential generated by the transmission line at the space Q point is the result of the combined action of all line charges, and the charge density can be obtained according to the known potential of the matching point of the surface of the lead
τ＝P -1 U (5)
Where τ is the charge density column vector; p is a potential coefficient matrix; u is the voltage column vector of each wire.
From this, the electric field intensity vector of the Q point can be obtained
In the method, in the process of the invention,
is the n-th wire inner l m The potential generated by the segment; e (E) x 、E y 、E z X, y, z3 directional components of the electric field respectively; e, e x 、e y 、e z The unit vectors are respectively in x, y and z3 directions; n is the phase line number; n is n 0 Is the number of overhead ground wires.
The effective value of the electric field intensity at the Q point is
In order to control the power frequency electric field intensity under the alternating current transmission line, a shielding line scheme is erected at a proper position under the alternating current transmission line, the shielding line scheme is substituted into a three-dimensional power frequency electric field calculation model of the established alternating current transmission line, and the shielding effect of the shielding line scheme is calculated by using a method based on improved analog charge.
The genetic algorithm has inherent hidden parallelism, and does not start from one point and conduct optimizing search along one line, but conducts optimizing search in the whole solution space at the same time, so that the genetic algorithm has good global optimal searching capability. In addition, the genetic algorithm is characterized by belonging to a randomized search algorithm, directly utilizing the information of the objective function to establish the optimizing direction, searching is independent of gradient information, the requirements of derivation and function continuity are not met, the limitation on the optimization design problem is less, and the method has wider applicability. Therefore, the genetic algorithm is applied to the power frequency electric field control system of the alternating current overhead transmission line, and the scheme of the optimal shielding effect is found in the shortest time.
The optimization method can also bring the construction cost into an optimization scheme, and the comprehensive engineering cost and the shielding effect seek an optimal scheme, so that references are provided for engineering design and the control scheme of the power frequency electric field of the alternating current overhead transmission line.
In order to find an optimal control scheme, a genetic algorithm is introduced, a power frequency electric field at an environment sensitive target is set as an objective function to be optimized, the minimum value of the optimization function is calculated, and the objective function is used as a fitness function for calculation. The mathematical expression of the optimization problem is:
wherein, f (X) -an objective function; e, the power frequency electric field intensity; x-optimizing variable solution vector; d, the outer diameter of the shielding wire; l is the length of the shielding wire; p (P) x -the lateral position of the shielding wire in the system; p (P) y -the longitudinal position of the shielding wire in the system; g i (X) -the ith constraint; n-the number of constraint conditions.
And (3) performing range constraint on each optimized variable, namely combining engineering practice to give a certain value range to each variable.
Based on the genetic algorithm overall optimization design concept, initializing optimization data, including the outer diameter of a shielding wire, the length of the shielding wire, the transverse position of the shielding wire, the longitudinal position of the shielding wire and the like, and finding out an optimal scheme of the shielding wire which meets the program ending condition through a series of fitness calculation, selection, crossing, variation and the like.
Examples
The invention is further described below with reference to the drawings and examples.
And establishing a three-dimensional power frequency electric field calculation model of the alternating current transmission line according to the catenary equation of the overhead transmission line.
The three-dimensional power frequency electric field of the alternating current transmission line, in particular the power frequency electric field intensity at the environment sensitive target is calculated by using an improved simulated charge method, and compared with the public exposure control limit value 4000V/m specified in the standard (electromagnetic environment control limit value (GB 8702-2014)) to determine the superscalar of the power frequency electric field intensity at the environment sensitive target.
In order to control the exceeding amount of the environmental sensitive target power frequency electric field intensity, a shielding line scheme is erected at a proper position below an alternating current transmission line, a shielding line model is brought into a three-dimensional power frequency electric field calculation model of the transmission line, and the shielding effect of the shielding line scheme is calculated by the method.
In order to find an optimal power frequency electric field control scheme, a genetic algorithm is applied to a power frequency electric field control system of an alternating current overhead transmission line, a power frequency electric field (or superscalar) at an environment sensitive target is set as an objective function to be optimized, parameters of factors affecting the power frequency electric field at the environment sensitive target are encoded, the minimum value of the objective function is calculated, and the objective function is used as a solved fitness function. The mathematical expression of the optimization problem is:
wherein, f (X) -an objective function; e, the power frequency electric field intensity; x-optimizing variable solution vector; d, the outer diameter of the shielding wire; l is the length of the shielding wire; p (P) x -the lateral position of the shielding wire in the system; p (P) y -the longitudinal position of the shielding wire in the system; g i (X) -the ith constraint; n-the number of constraint conditions.
And (3) performing range constraint on each optimized variable, namely combining engineering practice to give a certain value range to each variable.
As shown in fig. 3, the initial population pop (t) is randomly generated, the evolution algebra t=1, the number of individuals is N, and each individual is composed of the gene codes of chromosomes.
Calculating fitness f of each individual pop (t) in the population according to equation (12) i And judges whether the optimization criteria are met. If yes, outputting the optimal individual and the optimal solution represented by the optimal individual, and ending the calculation; otherwise, turning to the next step;
f i ＝fitness(pop i (t)) (12)
according to the probability distribution of formula (13), regenerated individuals are selected from the population pop (t), the probability that the individuals with high fitness are selected is high, and the individuals with low fitness are possibly eliminated, so that a new population is formed as shown in formula (14):
newpop(t+1)＝{pop j (t)|j＝1,2,...,N|} (14)
generating a new population cross (t+1) according to the cross probability Pc and a certain cross method;
generating a new population mutpop (t+1) according to the mutation probability Pm and a certain mutation method;
the evolution algebra t=t+1, generating a new generation population pop (t) =mutpop (t), and returning to calculate the fitness f of each individual pop (t) in the population according to equation (12) i 。
Convergence criteria for genetic algorithm: through multiple genetic operations such as selection, crossing, mutation and the like, the excellent quality of each generation of population is gradually accumulated, the average fitness of the population and the optimal individual fitness are continuously increased, and the iterative process tends to converge. The convergence criterion of the invention is that the two continuous optimal results are the same, namely the iterative times result, and the optimal scheme is output.
When the construction cost is included in the treatment scheme, the optimal treatment scheme is a scheme with the lowest construction cost under the condition of meeting the standard limit value of the power frequency electric field at the environment sensitive target, and the environmental benefit and the economic benefit can be organically combined.
Therefore, the invention provides a genetic algorithm-based alternating current overhead transmission line power frequency electric field control and optimization method, which comprises the following steps: firstly, a three-dimensional power frequency electric field calculation model of an alternating current transmission line is established according to a catenary equation of the overhead transmission line, then three-dimensional power frequency electric field distribution of the alternating current transmission line is calculated based on an improved simulated charge method, finally, a shielded wire erection method is adopted for power frequency electric field control measures under the alternating current transmission line, and a genetic algorithm is applied to the power frequency electric field control measures. The optimization method can also bring the construction cost into an optimization scheme, and under the condition of meeting the standard limit requirement of the power frequency electric field, the scheme with the lowest construction cost can organically combine the environmental benefit and the economic benefit, and the comprehensive engineering cost and the shielding effect seek an optimal scheme, thereby providing reference for engineering design and the power frequency electric field control scheme of the alternating current overhead transmission line.
As shown in fig. 4, another object of the present invention is to provide a power frequency electric field control system for an ac overhead transmission line, including:
the model building module is used for building a three-dimensional power frequency electric field calculation model of the alternating current transmission line according to a catenary equation of the overhead transmission line;
the electric field calculation module is used for erecting a shielding wire scheme at a proper position below the alternating current transmission line, substituting the shielding wire scheme into a three-dimensional power frequency electric field calculation model of the alternating current transmission line, and calculating the environmental sensitive target power frequency electric field strength of the shielding wire scheme by using an improved simulated charge method;
and the genetic algorithm module is used for adopting a genetic algorithm, setting a power frequency electric field at an environment sensitive target as an objective function to be optimized, solving the minimum value of the objective function, and taking the objective function as a solved fitness function.
As shown in fig. 5, a third object of the present invention is to provide an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, where the processor implements the steps of the ac overhead transmission line power frequency electric field control method when executing the computer program.
The power frequency electric field control method of the alternating current overhead transmission line comprises the following steps:
establishing a three-dimensional power frequency electric field calculation model of the alternating current transmission line according to a catenary equation of the overhead transmission line;
erecting a shielding wire scheme at a proper position below an alternating current transmission line, substituting the shielding wire scheme into a three-dimensional power frequency electric field calculation model of the alternating current transmission line, and calculating the environmental sensitive target power frequency electric field strength of the shielding wire scheme by using an improved simulated charge method;
and setting a power frequency electric field at an environment sensitive target as an objective function to be optimized by adopting a genetic algorithm, solving the minimum value of the objective function, and taking the objective function as a solved fitness function.
A fourth object of the present invention is to provide a computer readable storage medium storing a computer program which, when executed by a processor, implements the steps of the ac overhead transmission line power frequency electric field control method.
The power frequency electric field control method of the alternating current overhead transmission line comprises the following steps:
establishing a three-dimensional power frequency electric field calculation model of the alternating current transmission line according to a catenary equation of the overhead transmission line;
erecting a shielding wire scheme at a proper position below an alternating current transmission line, substituting the shielding wire scheme into a three-dimensional power frequency electric field calculation model of the alternating current transmission line, and calculating the environmental sensitive target power frequency electric field strength of the shielding wire scheme by using an improved simulated charge method;
and setting a power frequency electric field at an environment sensitive target as an objective function to be optimized by adopting a genetic algorithm, solving the minimum value of the objective function, and taking the objective function as a solved fitness function.
It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.
The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
Finally, it should be noted that: the above embodiments are only for illustrating the technical aspects of the present invention and not for limiting the same, and although the present invention has been described in detail with reference to the above embodiments, it should be understood by those of ordinary skill in the art that: modifications and equivalents may be made to the specific embodiments of the invention without departing from the spirit and scope of the invention, which is intended to be covered by the claims.
Claims (6)
1. The power frequency electric field control method for the alternating current overhead transmission line is characterized by comprising the following steps of:
establishing a three-dimensional power frequency electric field calculation model of the alternating current transmission line according to a catenary equation of the overhead transmission line;
erecting a shielding wire scheme at a proper position below an alternating current transmission line, substituting the shielding wire scheme into a three-dimensional power frequency electric field calculation model of the alternating current transmission line, and calculating the environmental sensitive target power frequency electric field strength of the shielding wire scheme by using an improved simulated charge method;
setting a power frequency electric field at an environment sensitive target as an objective function to be optimized by adopting a genetic algorithm, solving the minimum value of the objective function, and taking the objective function as a solved fitness function;
parameter coding is carried out on factors influencing the power frequency electric field at the environment sensitive target, the power frequency electric field at the environment sensitive target is set as an objective function to be optimized, and the method specifically comprises the following steps:
wherein, f (X) -an objective function; e, the power frequency electric field intensity; x-optimizing variable solution vector; d, the outer diameter of the shielding wire; l is the length of the shielding wire; p (P) x -the lateral position of the shielding wire in the system; p (P) y -the longitudinal position of the shielding wire in the system; g i (X) -the ith constraint; n-constraint number;
combining engineering reality to give a certain value range to each variable;
the genetic algorithm specifically comprises the following steps:
randomly generating an initial population pop (t), wherein the evolution algebra t=1, the number of individuals is N, and each individual consists of the gene codes of chromosomes;
calculating fitness f of each individual pop (t) in the population according to the following formula (a) i Judging whether the optimization criterion is met or not; if yes, outputting the optimal individual and the optimal solution represented by the optimal individual, and ending the calculation; otherwise, the next step is carried out;
f i ＝fitness(pop i (t)) (a)
selecting regenerated individuals from the population pop (t) according to the probability distribution of the following formula (b), wherein the individuals with high fitness are selected with high probability, and the individuals with low fitness are possibly eliminated, so as to form a new population (c):
newpop(t+1)＝{pop j (t)|j＝1,2,...,N|} (c)
generating a new population cross (t+1) according to the cross probability Pc and a certain cross method;
generating a new population mutpop (t+1) according to the mutation probability Pm and a certain mutation method;
the evolution algebra t=t+1, generates a new generation population pop (t) =mutpop (t), and returns to calculate the fitness f of each individual pop (t) in the population i ；
The initial population firstly carries out initialization optimization data, wherein the initialization optimization data comprises the outer diameter of a shielding wire, the length of the shielding wire, the transverse position of the shielding wire and the longitudinal position of the shielding wire;
the convergence criterion of the genetic algorithm is that the two continuous optimal results are the same, namely the iteration times result, and the optimal scheme is output.
2. The method of claim 1, wherein the step of determining the position of the substrate comprises,
the catenary equation of the overhead transmission line is as follows:
wherein z (x) is the ground height of a certain point of the overhead transmission line; sigma (sigma) 0 Is the horizontal stress of the wire; gamma is the specific load of the wire; h is the vertical distance between the hanging point and the ground; f (f) x Is a wire sag; l (L) OA The horizontal distance from the lowest point of the wire to the suspension point.
3. The method of claim 1, wherein the step of determining the position of the substrate comprises,
the method for calculating the environmental sensitive target power frequency electric field strength of the shielded wire scheme based on the improved simulated charge method specifically comprises the following steps:
let the density be τ m Is uniformly distributed in the nth wire m Segments, which generate potentials at spatial Q points (x, y, z)
Is that
Wherein ε 0 Is vacuum dielectric constant; r is (r) m 、r m ' is the distance from the source point and its mirror image to the field point;
the potential coefficient is
Thereby obtaining the wire l m Potential coefficient generated by the segment at point Q
Wherein x is m 、y m Respectively in the nth wire m The x, y axis coordinates of the segment; ρ m 、ρ m ' is the distance from the source point to the Q point and mirror image thereof, respectively;
the potential generated by the transmission line at the space Q point is the result of the combined action of all line charges, and then the charge density is obtained according to the known potential of the matching point on the surface of the lead
τ＝P -1 U
Where τ is the charge density column vector; p is a potential coefficient matrix; u is the voltage column vector of each wire;
thereby obtaining the electric field intensity vector of the Q point
In the method, in the process of the invention,
is the n-th wire inner l m The potential generated by the segment; e (E) x 、E y 、E z X, y, z3 directional components of the electric field respectively; e, e x 、e y 、e z The unit vectors are respectively in x, y and z3 directions; n is the phase line number; n is n 0 The number of overhead ground wires is the number;
the effective value of the electric field intensity at the Q point is
4. A system for controlling a power frequency electric field of an ac overhead transmission line based on the method of claim 1, comprising:
the model building module is used for building a three-dimensional power frequency electric field calculation model of the alternating current transmission line according to a catenary equation of the overhead transmission line;
the electric field calculation module is used for erecting a shielding wire scheme at a proper position below the alternating current transmission line, substituting the shielding wire scheme into a three-dimensional power frequency electric field calculation model of the alternating current transmission line, and calculating the environmental sensitive target power frequency electric field strength of the shielding wire scheme by using an improved simulated charge method;
and the genetic algorithm module is used for adopting a genetic algorithm, setting a power frequency electric field at an environment sensitive target as an objective function to be optimized, solving the minimum value of the objective function, and taking the objective function as a solved fitness function.
5. An electronic device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, the processor implementing the steps of the ac overhead transmission line power frequency electric field control method of any one of claims 1-3 when the computer program is executed.
6. A computer readable storage medium storing a computer program which when executed by a processor performs the steps of the ac overhead transmission line power frequency electric field control method of any one of claims 1 to 3.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2013185267A1 (en) * | 2012-06-15 | 2013-12-19 | 四川电力科学研究院 | Method for measuring three-dimensional power frequency electric field based on transmission line equivalent surface charge curve integral |
| CN106021848A (en) * | 2016-05-04 | 2016-10-12 | 国网重庆市电力公司电力科学研究院 | Extra-high voltage direct current transmission line ground total electric field shielding analysis method |
| EP3333736A1 (en) * | 2015-09-30 | 2018-06-13 | Osaka University | Method and program for calculating potential and current in electric circuit and surrounding electromagnetic field |
| CN111859714A (en) * | 2020-08-03 | 2020-10-30 | 国网重庆市电力公司电力科学研究院 | Power frequency electric field intensity calculation method and system and power frequency electric field shielding device |
-
2021
- 2021-08-12 CN CN202110926739.5A patent/CN113591397B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2013185267A1 (en) * | 2012-06-15 | 2013-12-19 | 四川电力科学研究院 | Method for measuring three-dimensional power frequency electric field based on transmission line equivalent surface charge curve integral |
| EP3333736A1 (en) * | 2015-09-30 | 2018-06-13 | Osaka University | Method and program for calculating potential and current in electric circuit and surrounding electromagnetic field |
| CN106021848A (en) * | 2016-05-04 | 2016-10-12 | 国网重庆市电力公司电力科学研究院 | Extra-high voltage direct current transmission line ground total electric field shielding analysis method |
| CN111859714A (en) * | 2020-08-03 | 2020-10-30 | 国网重庆市电力公司电力科学研究院 | Power frequency electric field intensity calculation method and system and power frequency electric field shielding device |
Non-Patent Citations (1)
| Title |
|---|
| 不同气象条件下特高压输电线路工频电场计算与档距选择;肖冬萍;何为;杨帆;张占龙;唐炬;;高电压技术(第09期);全文 * |
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