CN110768198B - A 10kV overhead insulated line lightning strike and disconnection comprehensive protection optimization method and device - Google Patents

Abstract

The present disclosure provides an optimization method and device for comprehensive protection against lightning strike and disconnection of a 10kV overhead insulated line. The method includes: obtaining the distribution network topology structure and its associated equipment parameters and the number of users, and constructing a distribution network simulation model; The disconnection rate and the impacted users under the two protection methods of no protection mode and lightning arrester and lightning arrester; according to the product of the disconnection rate of the jth protection method selected according to the impact of users after the disconnection of distribution line i and the disconnection rate of distribution line i Divide by the total number of users to obtain the average interruption frequency index of the distribution line i under the jth protection mode; construct the objective function with the minimum value of the average interruption frequency index, and use the particle swarm optimization algorithm to obtain the optimal value of the corresponding distribution line Protection mode; i means any distribution line; j=1,2,3; j=1 means no protection mode; j=2 means lightning protection mode; j=3 means lightning arrester protection mode.

Description

A 10kV overhead insulated line lightning strike and disconnection comprehensive protection optimization method and device

technical field

The disclosure belongs to the field of lightning strike protection for power distribution, and in particular relates to a method and device for comprehensive protection and optimization of lightning strike and disconnection of 10kV overhead insulated lines.

Background technique

The statements in this section merely provide background information related to the present disclosure and do not necessarily constitute prior art.

In recent years, according to the accident statistics of medium-voltage distribution lines, the number of faults of insulated conductors during operation is 15.3% of the total number of faults in the distribution network, and the number of faults has dropped significantly compared with bare conductors. Insulated conductors accounted for 36.8% of the total accidents, and the lightning break rate was 96.8%. Statistical data reflect that the lightning strike probability of insulated wire is relatively high. From the statistical data, it can be seen that the damage of insulated wire in a lightning strike accident is almost inevitable, and the probability of wire breakage is very high. According to domestic statistics, 10kV overhead insulated conductor lightning strikes and disconnection accidents account for a large part of the total number of lightning strikes and disconnections. There have been many incidents of insulated conductors being broken by lightning strikes across the country. In my country's Guangdong, Shenzhen, Beijing and other cities, after the use of insulated conductors is gradually common, there have also been many disconnection accidents caused by lightning strikes in thunderstorms. It can be seen that the lightning strike is an important reason for the operation accident of the insulated wire. The inventors found that the current simulation accuracy for comprehensive protection against lightning strike and disconnection of 10kV overhead lines is low, and the practicability is poor.

SUMMARY OF THE INVENTION

In order to solve the above problems, a first aspect of the present disclosure provides a comprehensive protection optimization method for 10kV overhead insulated line lightning strikes, which can improve the reliability of lightning strikes and disconnections and minimize the lightning strikes disconnection rate of the distribution network.

A first aspect of the present disclosure provides a comprehensive protection and optimization method for lightning strike and disconnection of a 10kV overhead insulated line, which includes:

Obtain the distribution network topology and its associated equipment parameters and number of users, and build a distribution network simulation model;

Based on the simulation model of the distribution network, the induction lightning strike distribution line simulation is carried out, and the disconnection rate and the number of affected users of the simulated distribution line under the unprotected mode and the two protection modes of the lightning protection line and the lightning arrester are obtained; where the disconnection rate is equal to The product of the total number of lightning strikes on the distribution line, the arc rate and the probability that the lightning current exceeds the critical current of flashover lightning;

According to the product of the number of users affected by the disconnection of distribution line i and the disconnection rate of the jth protection mode selected by distribution line i and divided by the total number of users, the average value of the jth protection mode selected by distribution line i is obtained. Interruption frequency index; the objective function is constructed with the minimum value of the average interruption frequency index of the current distribution line, and the total cost does not exceed the total investment amount as a constraint, and the optimal protection method of the corresponding distribution line is obtained; among them, i represents any distribution line. Electric line, i is a positive integer greater than or equal to 1; j=1, 2, 3; j=1 means no protection mode; j=2 means lightning protection wire protection mode; j=3 means lightning arrester protection mode.

A second aspect of the present disclosure provides a comprehensive protection and optimization device for lightning strike and disconnection of a 10kV overhead insulated line, which includes:

A distribution network simulation model building module, which is used to obtain the distribution network topology structure and its associated equipment parameters and number of users, and build a distribution network simulation model;

Induction lightning strike distribution line simulation module, which is used to simulate the induction lightning strike distribution line based on the distribution network simulation model, and obtain the disconnection rate of the simulated distribution line in the unprotected mode and the two protection modes of lightning arrester and lightning arrester. and the number of affected users; among them, the disconnection rate is equal to the product of the total number of lightning strikes on the distribution line, the arc rate and the probability that the lightning current exceeds the critical current of flashover lightning;

The module for obtaining the optimal protection of distribution lines is used to divide the product of the number of users affected by the disconnection of distribution line i and the disconnection rate of the jth protection mode selected by distribution line i by the total number of users to obtain The distribution line i selects the average interruption frequency index under the jth protection mode; the objective function is constructed with the minimum value of the average interruption frequency index of the current distribution line, and the total cost does not exceed the total investment amount as a constraint, and the corresponding distribution line is obtained. where, i represents any distribution line, i is a positive integer greater than or equal to 1; j=1, 2, 3; j=1 represents no protection mode; j=2 represents lightning protection mode ; j=3 represents the arrester protection mode.

A third aspect of the present disclosure provides a computer-readable storage medium on which a computer program is stored, and when the program is executed by a processor, implements the steps in the above-mentioned comprehensive protection optimization method for 10kV overhead insulated lines from lightning strikes.

A fourth aspect of the present disclosure provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, when the processor executes the program, the above-mentioned 10kV overhead is realized Steps in the optimization method for comprehensive protection against lightning strike and disconnection of insulated lines.

The beneficial effects of the present disclosure are:

The present disclosure performs induction lightning strike distribution line simulation based on the distribution network simulation model, and obtains the disconnection rate and the number of affected users of the simulated distribution line in the unprotected mode and the two protection modes of lightning arrester and lightning arrester. The product of the number of affected users after the disconnection of i and the disconnection rate of the jth protection mode selected by the distribution line i is divided by the total number of users to obtain the average interruption frequency index of the distribution line i under the jth protection mode selected; The objective function is constructed with the minimum value of the average interruption frequency index of the current distribution line, and the total cost does not exceed the total investment amount as the constraint condition, and the optimal protection method of the corresponding distribution line is obtained. Simulation technology is used to simulate the lightning strike of the overhead insulated line. , to find the optimal protection method, improve the reliability of lightning protection and disconnection, and minimize the lightning disconnection rate of the distribution network.

Description of drawings

The accompanying drawings that constitute a part of the present disclosure are used to provide further understanding of the present disclosure, and the exemplary embodiments of the present disclosure and their descriptions are used to explain the present disclosure and do not constitute an improper limitation of the present disclosure.

FIG. 1 is a flow chart of a comprehensive protection optimization method for lightning strike and disconnection of a 10kV overhead insulated line according to an embodiment of the present disclosure.

Figure 2 is the volt-ampere characteristics of the YH5WS3-17/50 arrester.

Figure 3 shows the simulation results of lightning protection after installing a group of arresters every other rod.

4 is a schematic structural diagram of a comprehensive protection and optimization device for lightning strike and disconnection of a 10kV overhead insulated line according to an embodiment of the present disclosure.

Detailed ways

The present disclosure will be further described below with reference to the accompanying drawings and embodiments.

It should be noted that the following detailed description is exemplary and intended to provide further explanation of the present disclosure. Unless otherwise defined, all technical and scientific terms used in the examples have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

It should be noted that the terminology used herein is for the purpose of describing specific embodiments only, and is not intended to limit the exemplary embodiments according to the present disclosure. As used herein, unless the context clearly dictates otherwise, the singular is intended to include the plural as well, furthermore, it is to be understood that when the terms "comprising" and/or "including" are used in this specification, it indicates that There are features, steps, operations, devices, components and/or combinations thereof.

Example 1

As shown in FIG. 1 , a comprehensive protection optimization method for 10kV overhead insulated line lightning strike and disconnection in this embodiment includes:

S101: Obtain the distribution network topology structure and its associated equipment parameters and the number of users, and construct a distribution network simulation model;

Specifically, the distribution network simulation model includes an insulator flashover model, an overhead line model, a lightning arrester model and a tower model.

At present, the flashover criteria of insulator strings for overhead lines in my country mainly include the following: definition method, intersection method and pilot method.

In my country's current industry standards and engineering practice, the definition method is usually used as the criterion for judging whether the insulator has flashover, that is, according to the calculation formula given in the regulations, by comparing the actual overvoltage value at both ends of the insulator string and its 50% impulse discharge The insulator is considered to have flashover when the actual overvoltage exceeds 50% of its impulse discharge voltage. Therefore, this method is also called the 50% discharge voltage method. In this embodiment, the P-15 type pin insulator is selected, and its 50% impulse discharge voltage is 117kV.

At present, the overhead line models in ATP-EMTP mainly include Bergeron model, π-shaped lumped parameter model, Node model, J.Marti model and Semlyen model. Because the J.Marti model has the advantages of wide application range and high calculation accuracy, it has been widely used in the lightning strike overhead line model. The main types of overhead lines are: LGJ-120, LGJ-70 and LGJ-35, of which LGJ-35 is the most widely used. In this embodiment, the J.Marti model without transposition is used to simulate the LGJ-35 overhead line.

The arrester model of this embodiment adopts zinc oxide arrester, and its lightning protection characteristics benefit from the nonlinear volt-ampere characteristics of its internal zinc oxide resistor valve. The nonlinear characteristics of its internal valve plate are described.

Wherein, p and q are both fixed values, and v _ref is the reference voltage of the arrester, which is taken as 10kV in this embodiment.

In the 10kV distribution line, the YH5WS3-17/50 arrester is used, and its volt-ampere characteristics are shown in Figure 2.

The inductance of the reinforced concrete pole without pulling wire is 0.84μh/m, and the inductance of the reinforced concrete pole with pulling wire is 0.42μh/m. In the ATP-EMTP simulation, a reinforced concrete pole without a cable is used to divide the tower into two parts, the upper part represents the top of the tower to the cross arm (about 1 meter), and the lower part represents the cross arm to the bottom of the tower ( about 10 meters).

S102: Perform induction lightning strike distribution line simulation based on the distribution network simulation model, and obtain the disconnection rate and the number of affected users of the simulated distribution line in the unprotected mode and the two protection modes of lightning arrester and lightning arrester; The rate is equal to the product of the total number of lightning strikes on the distribution line, the arc rate and the probability that the lightning current exceeds the critical current of flashover lightning;

By establishing the equivalent model of the distribution line, the transient process under the action of the lightning shock wave is simulated, and it is intended to be compared with the lightning resistance level of the line after the lightning protection measures are taken. Since the induced lightning overvoltage is proportional to the height of the transmission line, and the three-phase height of the transmission line is similar, the three-phase overvoltage level is similar, so only the waveform of one of the phases can be collected.

The common lightning current equivalent models in lightning impulse test and lightning protection design mainly include double exponential wave, oblique wave and Heilder. The lightning current waveform recommended by IEC 1312-1 is the Heilder model. Considering that the rising speed of the Heilder model is relatively slow, and the slightly longer falling time is more consistent with the measured results, this embodiment intends to use the Heilder exponent model to simulate the lightning shock wave, and the waveform parameters are set to 2.6/50.

The magnitude of the induced overvoltage on the line can be estimated by equation (2).

Among them, where U _IN is the maximum value of induced overvoltage on the line at this position. I ₀ is the peak value of lightning current (kA), h is the height of the conductor to the ground (m), and y is the horizontal distance from the lightning strike point to the tower. c is the speed of light and v is the speed of propagation of the return, usually c/3. In this embodiment, the calculation of the induced lightning is realized through the model model in ATP/EMTP.

The lightning protection effect after installing a group of arresters every other rod is simulated. The simulation results are shown in Figure 3.

After simulation, when a group of arresters is installed at every 1-level tower, the tower without arrester cannot be effectively protected. For insulators, there is still a greater possibility of flashover. The flashover rate of a group of arresters installed at every 1-level tower is 0.7554, which is only 7.2% compared with no arrester installed. The results show that the arrester has very little protection effect on the adjacent rod. Therefore, it can only play a good role if the arrester is continuously installed in the vulnerable section.

Table 1. Arrester installation density and flashover rate

Compared with the distribution line without the lightning protection line, the overvoltage amplitude at both ends of the insulator is effectively reduced due to the coupling between the lightning protection line and the conductor, which reduces the occurrence of line lightning strike and disconnection accidents.

In order to illustrate the interdependence between lightning and distribution system reliability, the system response characteristics under lightning conditions need to be established in mathematical modeling. For a given lightning protection system, it is necessary to calculate its lightning resistance level, that is, the lightning critical current I ₀ at which flashover occurs.

When calculating the induced lightning overvoltage of the overhead distribution line when the ground near the lightning strikes the line, in order to make the calculation basically reflect the value of the induced lightning overvoltage without being too complicated, the following falsehoods are made:

1) Only consider the induced voltage formed by the electrostatic effect and the magnetic effect generated during the main discharge backlash;

2) The charge distribution along the pilot channel is uniform, and the lightning strike is perpendicular to the ground;

3) The main discharge speed (lightning return speed) v is constant, and has a certain proportional relationship with the speed of light c;

4) The overhead line is an ideal conductor without loss.

The probability of lightning current exceeding _I0 is calculated as follows:

是雷电流具有的峰值电流超过I₀的概率。

is the probability that the lightning current has a peak current exceeding I ₀ .

i ₀ is the expected lightning peak current (kA).

After the insulator impact flashover caused by lightning strikes on distribution lines, not all of them will cause disconnection. Because the duration of the impact flashover is only tens of microseconds, the line is disconnected, and the impact arc must be converted into a stable power frequency arc. Due to the general heat resistance level of the overhead insulated line, the arc heat causes the line to melt and eventually disconnect. . According to the experiment and operation experience, the probability that the shock flashover turns into a stable power frequency arc is called the arc build rate. In the 10kV distribution network, the arc rate is determined by the lightning resistance level of the overhead insulated line and the voltage gradient of the insulator.

The lightning parameters are determined according to the location of the 10kV distribution network in actual operation, combined with the lightning resistance level, the probability that the lightning current exceeds I ₀ and the arc building rate η parameter to deduce the lightning breakage rate n of the 10kV overhead insulated line:

Among them, N is the total number of lightning strikes on the distribution line.

According to the mathematical model of the disconnection rate, the disconnection mechanism is revealed, and the key factors affecting the disconnection rate are given.

In this embodiment, three lightning strike protection methods are proposed for power distribution lines, namely, no protection, lightning protection line protection, and lightning arrester protection. Since the disconnection rate of the lightning strike of the distribution line is 96.8%, in this embodiment, the disconnection rate is calculated according to the most serious situation, that is, the tripping rate=the disconnection rate. Table 2 shows the lightning resistance level and disconnection rate of the line under the three modes of this embodiment.

Table 2. Statistics of disconnection rate in three modes

Way Lightning resistance level disconnection rate unprotected 17.8 2.5241 Lightning protection line 26.5 1.8970 lightning arrester >200 0

It can be seen from the above data that the safety of the line is extremely high when the arrester is continuous. However, due to the high economic cost of continuously installing the arrester in the distribution network, this protection method should be selectively installed for some lines. . The choice of the protection mode of the line should follow a certain principle, in the case of meeting the economic requirements, the reliability of the power supply of the system users should be improved as much as possible, and the instantaneous interruption and permanent interruption should be avoided.

S103: Divide the product of the number of users affected by the disconnection of the distribution line i and the disconnection rate of the jth protection mode selected by the distribution line i by the total number of users to obtain the jth protection mode selected by the distribution line i. The average interruption frequency index of the current distribution line is used to construct the objective function with the minimum value of the average interruption frequency index of the current distribution line. For a distribution line, i is a positive integer greater than or equal to 1; j=1, 2, 3; j=1 means no protection mode; j=2 means lightning protection line protection mode; j=3 means lightning arrester protection mode.

In the actual lightning protection reconstruction project, the electric power department often hopes to reduce the project cost as much as possible on the premise of ensuring the good lightning resistance performance of the line, so as to obtain a lower input-output ratio. According to market research, the market price of GJ-35 lightning protection line is about 8,000 yuan/ton. Therefore, for power distribution lines, it usually costs 4,000 yuan to install 1km lightning protection line. YH5WX17/50 type zinc oxide arrester, its market price is about 560 yuan/group, respectively adopt the installation scheme of the arrester described above, when each level of tower is installed with zinc oxide arrester, it will cost 9520 yuan/km. In addition, a good grounding system is required when installing the arrester. Therefore, when installing a lightning arrester, the grounding system will increase investment compared to when installing a lightning protection wire. This has also led to a widening gap in economic investment between the two.

The System Average Outage Frequency Index (SAIFI) indicates how often the average customer experiences sustained outages over a predetermined period of time. This index is directly related to the permanent failure of the system.

Among them, SAIFI _ij represents the average interruption frequency index of distribution line i under the protection mode j; B _i represents the number of affected users after line i is disconnected; i=1.2.3...,j=1.2.3; j represents the corresponding way of protection. No protection (j=1); lightning protection line (j=2); lightning arrester (j=3); B _T represents the total number of users; n _ij represents the disconnection rate.

m in SA IFI=SA IFI _ij x _ij

Among them, the value of x _ij is only 0 or 1, and when = 1, it means that the ith line selects the j mode protection;

cost means cost, invest means investment, there are 3 protection methods, 81 routes can only take one of them, and the sum is 1 as a constraint.

In this embodiment, in the process of simulating an induced lightning strike distribution line, the Heilder exponent model is used to simulate the lightning shock wave.

Specifically, compared with the traditional genetic algorithm (GA), the particle swarm optimization algorithm is simple and easy to implement and does not have many parameters to adjust, so it is widely used in neural networks, pattern classification, and function optimization. However, when dealing with complex problems, particle swarm optimization is easy to fall into the local optimal solution and stop motionless, which is the so-called premature convergence phenomenon. In this embodiment, the particle swarm optimization algorithm with the addition of genetic selection operator, crossover operator and mutation operator is used to obtain the optimal protection mode of the corresponding distribution line; wherein, the genetic selection operator is used to directly inherit the optimized individuals into The next generation or through paired crossover generates new individuals and then inherits them to the next generation; when the crossover operator approaches the neighborhood of the optimal solution, the local random search ability of the mutation operator is used to accelerate the convergence to the optimal solution.

The Particle Swarm Optimization (PSO) algorithm is an iterative-based optimization tool. Particles search for the optimal particle in the solution space, and search for the optimal value through continuous iteration. The main advantage of using the particle swarm optimization algorithm is that it has a relatively strong ability to search for better solutions, and the speed of optimization is relatively fast; at the same time, the optimal solution based on the particle swarm optimization algorithm model correction can be calculated more quickly and accurately.

The PSO algorithm randomly assigns a group of particles at first, and then the new particle swarm iteratively searches its vicinity until it reaches the optimal particle swarm in the solution space, that is, the optimal solution is achieved through continuous iteration. Assuming that in the N-dimensional search space, the position and velocity of the particle swarm are Xi=(xi1,xi2,xi3,...xin) and Vi=(vi1,vi2,vi3,...vin), respectively. In each In the iterative process, the particle replaces itself according to two optimal solutions: one is the optimal solution around the particle itself, that is, the optimal solution pbest in the individual; the other is the entire population before this iteration (including this iteration) Compare the optimal solution found, that is, the optimal solution gbest in the global. The process of each iteration updates velocity V and position X according to Equations 5 and 6.

是粒子第k次迭代中第n维的速度；

是粒子i在第k次迭代中第n维当前的位置；pbestin是粒子i在第n维个体极值点的位置；gbestin是整个种群在第n维全局极值点的位置；r1、r2是[0，1]上的随机数；c1、c2是学习因子。In the formula,

is the velocity of the nth dimension in the kth iteration of the particle;

is the current position of particle i in the nth dimension in the kth iteration; pbestin is the position of the individual extreme point of particle i in the nth dimension; gbestin is the position of the global extreme point of the entire population in the nth dimension; r1, r2 are Random numbers on [0, 1]; c1, c2 are learning factors.

Control parameters such as the number of particles, maximum speed, learning factor, inertia weight, etc. play a significant role in particle swarm optimization. Generally, about 40 particles can be selected to get good results, and 100 can be selected for more complex problems; the optimization problem determines the range of particles, and different ranges can be set for each latitude; the learning factor enables the particles to have self-summary and orientation The ability of excellent individuals in the group to learn, so as to approach the best point in the group or the best point in the neighborhood, generally c1=c2, the range is between 0 and 4; the inertia weight determines how much the particle inherits the current speed, and the appropriate choice of inertia Weights allow particles to have balanced exploration and development capabilities.

Particle swarm optimization algorithm is to simulate the process of bird predation. In the optimization process, the defined group of particles is a group of birds, and each particle defines its own position and velocity, and uses an n-dimensional vector to represent the velocity values of different particles. The same velocity is similar to a vector with the same latitude. The positions represent the solutions in the optimization problem.

Among them, the different operation simulates the process of gene mutation in biological evolution, and mutates a certain gene in the gene sequence. There are two main functions: one is to make the genetic algorithm have local random search ability. When the genetic algorithm approaches the optimal solution neighborhood through the crossover operator, the local random search ability of the mutation operator can accelerate the convergence to the optimal solution. The second is to make the genetic algorithm maintain population diversity to prevent premature convergence.

In this embodiment, based on the distribution network simulation model, the induction lightning strike distribution line simulation is performed, and the disconnection rate and the number of affected users of the simulated distribution line in the unprotected mode and the two protection modes of the lightning protection line and the lightning arrester are obtained. The product of the number of affected users after line i is disconnected and the disconnection rate of distribution line i choosing the jth protection mode is divided by the total number of users to obtain the average interruption frequency index of the distribution line i choosing the jth protection mode ;Construct the objective function with the minimum value of the average interruption frequency index of the current distribution line, and the total cost does not exceed the total investment amount as the constraint condition, obtain the optimal protection method of the corresponding distribution line, and use the simulation technology to simulate the lightning strike of the overhead insulated line. According to the situation, the optimal protection method is obtained to improve the reliability of lightning protection and disconnection, and to minimize the lightning disconnection rate of the distribution network.

Example 2

As shown in FIG. 4 , this embodiment provides a comprehensive protection and optimization device for lightning strike and disconnection of a 10kV overhead insulated line, which includes:

(1) A distribution network simulation model building module, which is used to obtain the distribution network topology and its associated equipment parameters and the number of users, and build a distribution network simulation model;

Among them, the distribution network simulation model includes the insulator flashover model, the overhead line model, the arrester model and the tower model.

(2) Induction lightning strike distribution line simulation module, which is used to simulate the induction lightning strike distribution line based on the distribution network simulation model, and obtain the simulated distribution line under the two protection modes of unprotected mode and lightning protection line and lightning arrester respectively. The disconnection rate and the number of affected users; among them, the disconnection rate is equal to the product of the total number of lightning strikes on the distribution line, the arcing rate and the probability that the lightning current exceeds the critical current of flashover lightning;

Wherein, in the inductive lightning strike distribution line simulation module, the Heilder exponent model is used to simulate the lightning shock wave.

(3) The module for obtaining the optimal protection of distribution lines, which is used to determine the product of the number of users affected by the disconnection of distribution line i and the disconnection rate of the jth protection mode selected by distribution line i and the total number of users. Divide to obtain the average interruption frequency index of distribution line i under the jth protection mode; construct the objective function with the minimum value of the average interruption frequency index of the current distribution line, and the total cost does not exceed the total investment amount as a constraint, and obtain the corresponding The optimal protection method for distribution lines; where i represents any distribution line, i is a positive integer greater than or equal to 1; j=1, 2, 3; j=1 represents no protection method; j=2 represents lightning protection Line protection mode; j=3 represents the arrester protection mode.

In the distribution line optimal protection obtaining module, the particle swarm optimization algorithm adding genetic selection operator, crossover operator and mutation operator is used to obtain the optimal protection mode of the corresponding distribution line; wherein, the genetic selection The operator is used to directly inherit the optimized individuals to the next generation or to generate new individuals through paired crossover and then to the next generation; when the crossover operator approaches the neighborhood of the optimal solution, the local random search ability of the mutation operator is used to accelerate the direction to the optimal solution. The optimal solution converges.

In this embodiment, based on the distribution network simulation model, the induction lightning strike distribution line simulation is performed, and the disconnection rate and the number of affected users of the simulated distribution line in the unprotected mode and the two protection modes of the lightning protection line and the lightning arrester are obtained. The product of the number of affected users after line i is disconnected and the disconnection rate of distribution line i choosing the jth protection mode is divided by the total number of users to obtain the average interruption frequency index of the distribution line i choosing the jth protection mode ;Construct the objective function with the minimum value of the average interruption frequency index of the current distribution line, and the total cost does not exceed the total investment amount as the constraint condition, obtain the optimal protection method of the corresponding distribution line, and use the simulation technology to simulate the lightning strike of the overhead insulated line. According to the situation, the optimal protection method is obtained to improve the reliability of lightning protection and disconnection, and to minimize the lightning disconnection rate of the distribution network.

Example 3

This embodiment provides a computer-readable storage medium on which a computer program is stored, and when the program is executed by a processor, implements the steps in the comprehensive protection optimization method for lightning strike and disconnection of a 10kV overhead insulated line as shown in FIG. 1 .

Example 4

This embodiment provides a computer device, including a memory, a processor, and a computer program stored in the memory and running on the processor, when the processor executes the program, the 10kV overhead insulated line shown in FIG. 1 is implemented Steps in an optimization method for comprehensive protection against lightning strikes.

In this embodiment, based on the distribution network simulation model, the induction lightning strike distribution line simulation is performed, and the disconnection rate and the number of affected users of the simulated distribution line in the unprotected mode and the two protection modes of the lightning protection line and the lightning arrester are obtained. The product of the number of affected users after line i is disconnected and the disconnection rate of distribution line i choosing the jth protection mode is divided by the total number of users to obtain the average interruption frequency index of the distribution line i choosing the jth protection mode ;Construct the objective function with the minimum value of the average interruption frequency index of the current distribution line, and the total cost does not exceed the total investment amount as the constraint condition, obtain the optimal protection method of the corresponding distribution line, and use the simulation technology to simulate the lightning strike of the overhead insulated line. According to the situation, the optimal protection method is obtained to improve the reliability of lightning protection and disconnection, and to minimize the lightning disconnection rate of the distribution network.

The above descriptions are only preferred embodiments of the present disclosure, and are not intended to limit the present disclosure. For those skilled in the art, the present disclosure may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present disclosure shall be included within the protection scope of the present disclosure.

Claims (10)

1. A lightning stroke broken line comprehensive protection optimization method for a 10kV overhead insulated line is characterized by comprising the following steps:

acquiring a power distribution network topological structure, associated equipment parameters and the number of users, and constructing a power distribution network simulation model;

carrying out induction lightning distribution line simulation based on a power distribution network simulation model to obtain the line breakage rate and the number of influencing users of the simulated distribution line in an unprotected mode and in three protection modes of a lightning conductor and a lightning arrester; the disconnection rate is equal to the product of the total lightning number on the distribution line, the arcing rate and the probability that the lightning current exceeds the critical current of flashover lightning;

dividing the product of the number of influencing users after the distribution line i is disconnected and the disconnection rate of the distribution line i in the jth protection mode selected by the total number of users to obtain an average interruption frequency index of the distribution line i in the jth protection mode selected by the jth user; constructing a target function according to the minimum value of the average interruption frequency index of the current distribution line, and solving the optimal protection mode of the corresponding distribution line by taking the total cost not exceeding the total investment amount as a constraint condition; wherein i represents any distribution line, and is a positive integer greater than or equal to 1; j is 1,2, 3; j ═ 1 represents an unprotected mode; j is 2 to represent a lightning conductor protection mode; j-3 indicates the lightning arrester protection mode.

2. The lightning stroke and disconnection comprehensive protection and optimization method for the 10kV overhead insulated line according to claim 1, wherein the power distribution network simulation model comprises an insulator flashover model, an overhead line model, a lightning arrester model and a tower model.

3. The lightning stroke broken line comprehensive protection and optimization method for the 10kV overhead insulated line according to claim 1, wherein in the process of simulating the distribution line by induction lightning stroke, a Heilder index model is adopted to simulate lightning shock waves.

4. The lightning stroke broken line comprehensive protection optimization method for the 10kV overhead insulated line according to claim 1, wherein the optimal protection mode of the corresponding distribution line is obtained by utilizing a particle swarm optimization algorithm with genetic selection operators, crossover operators and mutation operators; wherein, the genetic selection operator is used for directly inheriting the optimized individuals to the next generation or generating new individuals through pairing and crossing and then inheriting the new individuals to the next generation; when the cross operator approaches the neighborhood of the optimal solution, the convergence to the optimal solution is accelerated through the local random search capability of the mutation operator.

5. The utility model provides a 10kV overhead insulated line thunderbolt broken string comprehensive protection optimizing apparatus which characterized in that includes:

the power distribution network simulation model building module is used for obtaining a power distribution network topological structure, and associated equipment parameters and the number of users of the power distribution network topological structure to build a power distribution network simulation model;

the power distribution line simulation system comprises an induction lightning distribution line simulation module, a power distribution network simulation module and a power distribution network simulation module, wherein the induction lightning distribution line simulation module is used for carrying out induction lightning distribution line simulation based on a power distribution network simulation model to obtain the line breakage rate and the number of influencing users of the simulation power distribution line in an unprotected mode and in three protection modes of a lightning conductor and a lightning arrester; the disconnection rate is equal to the product of the total lightning number on the distribution line, the arcing rate and the probability that the lightning current exceeds the critical current of flashover lightning;

the optimal protection calculation module of the distribution line is used for dividing the product of the number of influencing users after the distribution line i is broken and the breakage rate of the j-th protection mode selected by the distribution line i by the total number of users to obtain an average interruption frequency index of the distribution line i in the j-th protection mode selected; constructing a target function according to the minimum value of the average interruption frequency index of the current distribution line, and solving the optimal protection mode of the corresponding distribution line by taking the total cost not exceeding the total investment amount as a constraint condition; wherein i represents any distribution line, and is a positive integer greater than or equal to 1; j is 1,2, 3; j ═ 1 represents an unprotected mode; j is 2 to represent a lightning conductor protection mode; j-3 indicates the lightning arrester protection mode.

6. The 10kV overhead insulated line lightning stroke disconnection comprehensive protection optimization device of claim 5, wherein the power distribution network simulation model comprises an insulator flashover model, an overhead line model, a lightning arrester model and a tower model.

7. The 10kV overhead insulated line lightning breakage comprehensive protection optimization device of claim 5, wherein in the induced lightning distribution line simulation module, a Heilder index model is adopted to simulate lightning shock waves.

8. The 10kV overhead insulated line lightning stroke disconnection comprehensive protection optimization device of claim 5, wherein in the distribution line optimal protection obtaining module, a particle swarm optimization algorithm with a genetic selection operator, a crossover operator and a mutation operator is used for obtaining the optimal protection mode of the corresponding distribution line; wherein, the genetic selection operator is used for directly inheriting the optimized individuals to the next generation or generating new individuals through pairing and crossing and then inheriting the new individuals to the next generation; when the cross operator approaches the neighborhood of the optimal solution, the convergence to the optimal solution is accelerated through the local random search capability of the mutation operator.

9. A computer-readable storage medium, on which a computer program is stored, wherein the program, when executed by a processor, implements the steps in the method for optimizing lightning protection against broken wire of 10kV overhead insulated line according to any one of claims 1 to 4.

10. A computer device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the processor when executing the program implements the steps in the method for optimizing lightning stroke and breakage protection of 10kV overhead insulated line according to any one of claims 1 to 4.

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