CN111695231A

CN111695231A - Practical reliability analysis method for complex power distribution network information physical system

Info

Publication number: CN111695231A
Application number: CN202010246696.1A
Authority: CN
Inventors: 林丹; 余涛
Original assignee: South China University of Technology SCUT
Current assignee: South China University of Technology SCUT
Priority date: 2020-04-01
Filing date: 2020-04-01
Publication date: 2020-09-22

Abstract

The invention provides a practical reliability analysis method for a complex power distribution network information physical system. The method comprises the following steps: inputting general parameters of elements of a physical system of the power distribution network and simplifying a topological connection relation; inputting general reliability parameters and terminal online rates of automatic terminals in a power distribution network information system; extracting the states of the current physical system and the current automatic terminal by using a Monte Carlo method; searching the state of the associated terminal and calculating the fault isolation time of the fault; analyzing the fault isolation area and the influence of the fault isolation area on the power failure time of the load; updating simulation time, counting the reliability index of each load if the simulation finishing condition is reached, or extracting the current states of the physical system and the automatic terminal again; and calculating and outputting the reliability index of the whole power distribution network information physical system. The reliability evaluation method can evaluate the reliability of the complex power distribution network information physical system more accurately and more carefully, and is more suitable for the reliability evaluation and planning of the stock power distribution network and the intelligent power distribution network.

Description

Practical reliability analysis method for complex power distribution network information physical system

Technical Field

The invention relates to the field of reliability analysis of power distribution networks, in particular to a practical reliability analysis method for a complex power distribution network information physical system.

Background

The power distribution network is a bridge connecting the power transmission network and users, and along with the development of national economy and the improvement of the requirements of the living standard of people, the requirements on the power supply reliability of the power distribution network are increased day by day. The importance of reliability analysis and calculation of the power distribution network is increasingly highlighted in the work of the power distribution network, such as the transformation of stock power networks and the planning of newly built parks.

The existing power distribution network reliability algorithm is mostly based on some simplifying assumptions, such as that a switching element is completely reliable; all switching elements can be remotely monitored and controlled; all the branch lines have simple structures and do not have sub-branch lines; and the branch line outlet end switch is switched off after the element in the branch line is in fault, and the action of other switches in the branch line is not required to be considered, and the like. These assumptions are that the reliability analysis process avoids the difficulties caused by the diversity of elements of the power distribution network and the complexity of the grid structure, but also results in that the calculation result is not accurate enough when the obtained reliability analysis method is applied to the actual power distribution network (reliability evaluation [ J ] power automation equipment of the power distribution network information physical system considering the whole fault processing process, 2017).

In recent years, the development of power distribution network technology brings new changes to the power distribution network, and the creation of concepts such as smart power grids, transparent power grids, power distribution network information physical systems and the like puts forward many new requirements on the construction and operation of the power distribution network, and the concepts cannot be realized without advanced intelligent equipment, communication technology, sensing technology, system analysis and calculation technology and the like. With the increasing application of information communication technology to monitoring and control of power distribution networks, the high coupling of information communication networks and power distribution networks makes power distribution systems gradually become information physical systems, which means that past power distribution network reliability analysis methods are no longer suitable for the current power distribution network information physical systems.

Currently, researchers research a reliability analysis method suitable for a power distribution network information physical system, however, the existing research results are based on the assumption that all switches (outgoing line circuit breakers, section switches and interconnection switches) are provided with three remote terminals, and the condition that part of switches are provided with one remote terminal or two remote terminals is not considered; moreover, reliability analysis is only performed on a certain communication system, and the method cannot be applied to various communication systems (such as industrial Ethernet, EPON and wireless public network) (power distribution network information physical system reliability evaluation [ J ] power system and automation report thereof, 2019 of EPON is considered). The remote terminal, namely a fault indicator, has the function of reducing the time for a worker to patrol the line to check a fault point of the line; the two remote terminals have remote signaling and remote measuring functions, can measure the state quantities of the current and voltage systems of the switch equipment or the ring network unit when a circuit fails, and upload the state quantities to a power distribution substation or a power distribution main station to help workers to remotely determine the range of a fault point; the three-remote terminal has remote signaling, remote measuring and remote controlling functions, and can enable a worker to remotely control the switch besides the function of the two-remote terminal.

In addition, the existing reliability analysis method for the information physical system of the power distribution network has high requirement on input data due to the fact that a mathematical model is too fine in some aspects (power distribution network reliability assessment [ J ] power system automation considering multi-type information disturbance, 2019). However, as can be known from research on the power supply bureau, it is difficult to obtain some input data, such as annual fault rate, mean fault repair time, etc., of components such as optical cables, switches, etc., in the power distribution network communication system, and such data are not within the daily statistics and assessment range of the power supply bureau and can be obtained only by the power supply bureau contacting with a manufacturer to perform data analysis. The distribution network reliability analysis method serves a power supply bureau, so a practical reliability analysis method should be designed from the perspective of the power supply bureau.

In summary, the actual power distribution network has a complex grid structure and various switching elements and power distribution terminals, and it is urgently needed to develop a practical reliability analysis method which is applicable to an actual power distribution network information physical system, considers the situation that a remote terminal, a remote terminal and a remote terminal are configured in a mixed manner, can calculate the situation that a plurality of sub-branch lines and various switching elements exist in the branch lines of the power distribution network, can adapt to the situation of different communication systems, and is convenient for a power supply bureau to obtain data sources. Therefore, the invention provides a practical reliability analysis method of the complex power distribution network information physical system from the whole fault processing process in order to meet the reliability analysis requirement of the current power distribution network information physical system.

Disclosure of Invention

The invention provides a practical reliability analysis method for a complex power distribution network information physical system, which is used for analyzing the functions of the power distribution network information system comprising three automatic terminals and the influence of faults on the reliability of the complex power distribution network information physical system from the whole fault processing process.

The purpose of the invention is realized by at least one of the following technical solutions.

The practical reliability analysis method of the complex power distribution network information physical system comprises the following steps:

s1, inputting a simplified topological connection relation matrix of elements of the physical system of the power distribution network and general parameters of each element of the physical system of the power distribution network, and inputting a plurality of time parameters related to fault processing of a power supply company;

s2, inputting general reliability parameters of automatic terminals in the power distribution network information system, and inputting the corresponding relation between each terminal and the switch where the terminal is located;

s3, extracting the fault element of the current physical system and the normal working time and the fault repairing time thereof by using a sequential Monte Carlo method; extracting the states of all automatic terminals in the current information system by using a non-sequential Monte Carlo method;

s4, inquiring the states of all the associated terminals of the fault elements of the physical system, and calculating the fault isolation time of the fault;

s5, analyzing the relay protection isolation area, the primary isolation area and the final isolation area of the fault, and obtaining the power failure time and the power shortage amount of each load caused by the fault;

s6, updating the simulation time, judging whether the simulation finishing condition is reached, if so, performing the step S7, otherwise, performing the step S3;

s7, counting the reliability indexes of each load;

and S8, calculating and outputting the reliability index of the whole power distribution network information physical system, and assisting planning or transformation of the power distribution network according to the output reliability index.

Further, in step S1, the elements of the power distribution network physical system include lines, switching elements, transformers, and loads, where the switching elements include circuit breakers, sectionalizers, tie switches, and fuses;

each row of the simplified power distribution network physical system element topological connection relation matrix Brancha represents a section of simplified line, the first column is a first node of the section of simplified line, the second column is a last node of the section of simplified line, the third column is the type of the section of simplified line, and the fourth column is the length of the section of simplified line; the nodes comprise a power supply node and a load node, wherein the power supply node is a variable-low side of a 10kV transformer substation, and the load node is a node with a user branch line consisting of a fuse, a line, a transformer and a load at the downstream; the power flow direction of each simplified line section is from the first node to the last node; the simplified line types comprise 6 types, namely pure lines, a pure line section connected behind a switch without terminal configuration, a pure line section connected behind a remote switch, a pure line section connected behind a two-remote switch, a pure line section connected behind a three-remote switch, and a pure line section connected behind a breaker; the simplified topological connection relation matrix of the elements of the physical system of the power distribution network can be obtained by simplifying the actual power grid topology, and the simplifying principles are two:

the method comprises the following steps that principle 1, a section switch, a circuit breaker and a section switch or a circuit following the circuit breaker are simplified into a simplified circuit, wherein the section switch comprises a section switch without terminal configuration, a section switch with a remote terminal configuration and a section switch with a remote terminal configuration;

principle 2, simplifying the user branch line and the head end node of the branch line into a load node;

the general parameters of each element of the physical system of the power distribution network comprise: the annual fault rate and the average repair time of each element in 7 types of elements, namely a circuit breaker, a section switch, a tie switch, a fuse, a line, a transformer and a load, the average load of all load elements and the length of each line element of all user branch lines;

generating a matrix BranchB representing the element parameters of the physical system of the power distribution network and the topological connection relation thereof through the matrix BranchA and the general parameters of each element of the physical system of the power distribution network; each row of the matrix branch represents an element, the first column is the first node of the element, the second column is the last node of the element, the third column is the type of the element, the fourth column is the annual fault rate of the element, the fifth column is the average repair time of the element, the sixth column is the length of a line, the value of the sixth column is null for non-line elements, the seventh column is the average load of the load, the value of the seventh column is null for non-load elements, the eighth column is the number of switching elements, and the value of the eighth column is null for non-switching elements;

in the subsequent steps, the matrix BranchB is mainly used for extracting fault elements of a physical system of the power distribution network, and the matrix BranchA is mainly used for topology search in fault isolation time analysis and fault influence load analysis;

the plurality of times related to the fault handling of the power supply company comprise the time of remotely controlling the action of a single three-remote switch, the average time of a maintainer arriving at a fault feeder, the time of the maintainer checking the listing condition of a single one-remote terminal, the line patrol time of the maintainer for determining the line of unit length at the position of a fault point, and the time of the maintainer operating the action of a single non-remote switch on site.

Further, in step S2, the reliability parameters common to the automation terminals in the power distribution network information system include: the fault rate and the average repair time of a fault indication module of each type of terminal in the first remote terminal, the second remote terminal and the third remote terminal which are all 3 types of terminals, the terminal on-line rate of each type of remote terminal in the second remote terminal, the third remote terminal and the 2 types of remote terminals, and the fault rate of an electric operation module of the third remote terminal;

generating a matrix BranchC representing reliability parameters of terminal elements of the power distribution network information system and topological connection relation between the terminal elements and a physical system through the universal reliability parameters of the automatic terminals and the corresponding relation between each terminal and a switch where the terminal is located; each row of the matrix ranchc represents a terminal, the first column is the type of the terminal, the second column is the number of the terminal corresponding to a switch element of a physical system, namely, the number corresponds to the eighth column of ranchb, the third column is the failure rate of a failure indication module of the terminal, the fourth column is the failure rate of an electric operation module of a three-remote terminal, for non-three-remote terminals, the value of the fourth column is null, the fifth column is the average repair time of the terminal, and the sixth column is the terminal on-line rate of the terminal;

in the subsequent step, the matrix BranchC is mainly used for terminal state extraction of the power distribution network information system.

Further, in step S3, the extracting the current state of the physical system by using the sequential monte carlo method calculates and simulates the normal operation time Δ t of all elements in the physical system of the distribution network according to the following formula₁(year):

wherein, the interval (0,1) is a random number which is uniformly distributed, P₀Is the probability of failure of the element; all the elements in the physical system and the information system, or the component modules of the elements, the failure probability of which can be calculated by the following formula:

wherein λ is an annual failure rate of the component or the component module of the component, μ is an annual repair rate of the component or the component module of the component, and a calculation formula of μ is as follows:

wherein r is the mean time to failure repair of the component or component module;

then selecting the physical system component k with the shortest normal working time in the simulation, defining the fault point in the simulation as the component k, and calculating and simulating the fault repairing time delta t of the component k according to the following formula₂(hours):

Δt₂＝-r×ln；

thereby obtaining the current objectThe state of the physical system is that all physical elements are in normal operation at₁After that time, the component k fails, and it takes time Δ t to repair the failure of the component k this time₂；

Sampling all automatic terminals in the current information system by using a non-sequential Monte Carlo method, which specifically comprises the following steps:

assigning each remote terminal element a random number for extracting whether a remote terminal can normally complete the fault indication; if the random number is greater than or equal to the failure probability P of the fault indication module of the remote terminal₀₁If not, the remote terminal can not complete the fault indication normally;

giving two random numbers to each two-remote terminal element for extracting whether the two-remote terminal can normally complete fault indication and whether the two-remote terminal is on-line or not; if the first random number is greater than or equal to the failure probability P of the fault indication module of the two-remote terminal₀₂If the second random number is larger than or equal to the terminal on-line rate of the two remote terminals, the two remote terminals are on-line, otherwise, the two remote terminals are not on-line;

giving three random numbers to each three-remote terminal element for extracting whether the three-remote terminal can normally complete fault indication, whether the electric operation module can normally act and whether the three-remote terminal is on line; if the first random number is greater than or equal to the failure probability P of the fault indication module of the three-remote terminal₀₃₁If the second random number is larger than or equal to the failure probability P of the electric operation module of the three-remote terminal, the three-remote terminal can normally complete the fault indication, otherwise, the three-remote terminal cannot normally complete the fault indication, and if the second random number is larger than or equal to the failure probability P of the electric operation module of the three-remote terminal₀₃₂If the third random number is larger than or equal to the terminal on-line rate of the three-remote terminal, the three-remote terminal is on-line, otherwise, the three-remote terminal is not on-line;

all random numbers given to the one-, two-and three-remote terminal elements belong to the interval (0,1) and are subject to uniform distribution; if the terminal cannot normally complete the fault indication, the condition that the terminal causes the missed judgment or the erroneous judgment is represented; if the terminal is not on-line, the terminal cannot establish a remote communication relationship with the power distribution main station or the substation; if the three-remote terminal electric operation module can not normally act, the power distribution main station or the substation can not remotely control the three-remote switch to be closed or opened, but the on-site manual operation of the maintenance personnel on the three-remote switch to be closed or opened is not influenced.

Further, after sampling the physical system and the automatic terminals of the power distribution network by using a Monte Carlo method, the states of all the automatic terminals in the information system are obtained, and the specific steps are as follows:

a remote terminal has two states: defining a remote terminal capable of normally finishing fault indication as a first state of the remote terminal, and defining a remote terminal incapable of normally finishing fault indication as a second state of the remote terminal;

the two remote terminal has three states: defining that the two-remote terminal can normally complete fault indication and is in a first state of the two-remote terminal on line, defining that the two-remote terminal cannot normally complete fault indication and is in a second state of the two-remote terminal on line, and defining that the two-remote terminal is not in a third state of the two-remote terminal on line;

the three remote terminals have five states: the method comprises the steps of defining that a three-remote terminal can normally complete fault indication, an electric operation module can normally act and is in a first state of the three-remote terminal on line, defining that the three-remote terminal cannot normally complete fault indication, the electric operation module can normally act and is in a second state of the three-remote terminal on line, defining that the three-remote terminal can normally complete fault indication, the electric operation module cannot normally act and is in a third state of the three-remote terminal on line, defining that the three-remote terminal cannot normally complete fault indication, the electric operation module cannot normally act and is in a fourth state of the three-remote terminal on line, and defining that the three-remote terminal cannot be in a fifth state of the three-remote terminal on line;

if the two remote terminals configured by the switch element are in the third state of the two remote terminals, the switch element is equivalent to be not configured with any terminal, namely the switch of the two remote terminals in the third state of the two remote terminals is regarded as not configured with any terminal; if the three remote terminal configured by the switch element is in the third state of the three remote terminal, the terminal configured by the switch element is equivalent to the two remote terminal in the first state of the two remote terminal, namely the switch of the three remote terminal in the third state of the three remote terminal is regarded as the two remote terminal configured in the first state of the two remote terminal; if the three remote terminal configured by the switch element is in the fourth state of the three remote terminal, the terminal configured by the switch element is equivalent to the second remote terminal in the second state of the second remote terminal, namely the switch of the three remote terminal in the fourth state of the three remote terminal is regarded as the second remote terminal configured in the second state of the second remote terminal; if the three-remote terminal configured by the switch element is in the fifth state of the three-remote terminal, it is equivalent to that the switch element is not configured with any terminal, that is, the switch of the three-remote terminal in the fifth state of the three-remote terminal is regarded as not configured with any terminal.

Further, in step S4, the analysis of the fault isolation time is related to the states of all associated terminals of the physical system fault element, and also related to the type of the switch closest to the physical system fault element and the type of the terminal of the switch configuration; the analysis of the fault isolation time follows the principle that the breaker and the interconnection switch are both provided with three remote terminals and follows the principle that the feeder line outlet end is provided with the breaker;

defining a remote terminal as a two-remote terminal or a three-remote terminal, and defining a local terminal as a one-remote terminal; based on the method, all the associated terminals of the fault elements of the physical system are divided into two categories, one is a remote associated terminal, and the other is a local associated terminal;

the remote association terminal defining the fault element of the physical system is as follows: the number of remote terminals on the minimum path between the remote terminal and the fault element is not more than 1;

the local associated terminal of the fault element of the physical system is defined as follows: the number of local terminals on the minimum path between the local terminals and the fault element is not more than 1, and the local terminals have no remote terminals;

defining the time of the switch action of the remote control configuration three-remote terminal as t₁When defining fault isolationIs m between t₂Defining the time for repairing the fault as t₃(ii) a Time to fail over is t₃Is taken as Δ t obtained by sampling the failed element of the physical system in step S3₂(ii) a Time t of fault isolation₂Including the time t of the journey of the worker to the faulty feeder₂₁Time t for locating fault₂₂And field operation switch time t₂₃The calculation formula is as follows:

t₂＝t₂₁+t₂₂+t₂₃；

time t for locating fault₂₂Including the listing condition viewing time t of all remote terminals in the actual remote fault location area₂₂₁And the line patrol time t of the actual line patrol area₂₂₂The calculation formula is as follows:

t₂₂＝t₂₂₁+t₂₂₂；

time t is looked over to hang tablet condition of all remote terminals in actual remote fault location area₂₂₁The calculation formula is as follows:

t₂₂₁＝n_yiyaot_yiyao；

wherein n is_yiyaoFor locating the number of all remote terminals in the segment, t_yiyaoThe time taken to check a single one-remote terminal;

line patrol time t of actual line patrol area₂₂₂The calculation formula is as follows:

t₂₂₂＝l_patrolt_patrol；

wherein l_patrolIs the length of the actual tour section, t_patrolThe line patrol time of a line with unit length is taken;

after the fault location is completed by the maintainer, it may be necessary to operate the switching elements that cannot be remotely controlled in the field to isolate the faulty element, as follows:

case 1, if the upstream switch nearest to the failed element cannot be remotely controlled, then that switch is included in the set of switches that need to be operated in the field; the switch which is closest to the fault element means that no other switch exists on the minimum path between the switch and the fault element;

case 2, if the faulty element is a main feeder element, and the feeder has a condition for transferring power, and the downstream switch nearest to the faulty element cannot be remotely controlled, then the switch is included in the set of switches that need to be operated in the field; the main feeder is defined as a feeder path with the longest length in all feeder paths conforming to the power flow direction from the power supply node to all load nodes, namely, the feeder path between the power supply node and the load node farthest from the power supply node from the perspective of the feeder path;

case 3, if the faulty element is a branch element and there is no switching element on the branch upstream of the faulty element and the feeder has a condition for transferring power, and the switch on the main feeder that is closest to the faulty element and that is not on the smallest path of the faulty element to the power supply node cannot be remotely controlled, then the switch is included in the set of switches that need to be operated in the field;

on-site operation switch time t₂₃The calculation formula of (a) is as follows:

t₂₃＝n_manualt_manual；

wherein n is_mamualNumber of switches in the set of switches that need to be operated in the field, t_mamualTime to operate a single switch in the field;

defining the correct remote fault location area as: an area enclosed by all remote terminals in closest proximity to the failed component; the remote terminal which is closest to the fault element means that no other remote terminal exists on the minimum path between the remote terminal and the fault point; if all the remote associated terminals of the fault point are in the first state in the simulation, the actual remote fault location area is consistent with the correct remote fault location area; if all the remote associated terminals of the fault point are not in the first state in the simulation, the actual remote fault location area is equal to the correct remote fault location area plus the wrong remote fault location area;

defining the correct line patrol area as follows: the area enclosed by all terminals in the closest vicinity of the faulty component; the nearest terminal means that no other terminal exists on the minimum path between the terminal and the fault point; if all the remote associated terminals and the local associated terminals of the fault point are in the first state in the simulation, the actual line patrol area is consistent with the correct line patrol area; if all the remote associated terminals and the local associated terminals of the fault point are not in the first state in the simulation, the actual line patrol area is equal to the correct line patrol area plus the wrong line patrol area;

all remote associated terminals of a fault point can be classified into four categories, specifically as follows:

the remote terminal is called as a type I remote association terminal, wherein the remote terminal is positioned on the minimum path between the fault point and the power supply node and has no other remote terminal on the minimum path between the fault point and the fault point; the remote terminal is a type I remote association terminal on the minimum path between the fault point and the power supply node and the minimum path between the fault point and the remote association terminal, and is called as a type II remote association terminal; the remote terminal is not positioned on the minimum path between the fault point and the power supply node and has no other remote terminal on the minimum path between the fault point and the remote terminal, and is called as a type III remote association terminal; the remote terminal is not positioned on the minimum path between the fault point and the power supply node and is provided with a remote association terminal on the minimum path between the fault point and the remote association terminal, and the remote association terminal is called as an IV-type remote association terminal;

all local associated terminals of a fault point can be classified into four categories: a remote terminal which is on the minimum path between the fault point and the power node and has no other terminal on the minimum path between the fault point and the remote terminal is called as an I-type local association terminal; a remote terminal which is on the minimum path between the fault point and the power supply node and has no other terminal except an I-type local association terminal is called as a II-type local association terminal; the remote terminal is not positioned on the minimum path between the fault point and the power supply node and has no other terminal on the minimum path between the fault point and the remote terminal, and is called as a type III local association terminal; the remote terminal which is not positioned on the minimum path between the fault point and the power supply node and is provided with a remote terminal and no other terminal except the remote terminal is called as a type IV local association terminal;

defining a remote area as an area which is surrounded by the remote terminals and has no other remote terminals inside; defining a field area as an area which is surrounded by terminals and has no terminal inside; the incoming switch of the defined area is a switch which is positioned at the boundary of the area and the direction of the power flow flowing through the switch is the direction of the power flow in the area outside the area; defining the switch of the region as a switch which is positioned at the boundary of the region and has the direction of the power flow flowing through the switch as the direction outside the pointing region in the region; only one in switch and one out switch of one area may not exist, or only one or more in switches may exist;

the rule of the wrong remote fault positioning area or the wrong line patrol area under the condition of judging the misjudgment or the missed judgment of the remote associated terminal is as follows:

a1, when a class I remote association terminal is subjected to miss judgment, if a switch where the miss judgment terminal is located is not a feeder outlet switch, a caused error remote fault location area is a remote area where the switch where the miss judgment terminal is located is used as an outlet switch, at least one error routing area is caused, at most two error routing areas are caused, a first error routing area is a field area where the switch where the miss judgment terminal is located is used as the outlet switch, and if an inlet switch of the first error routing area is not the feeder outlet switch, a second error routing area is a field area where an inlet switch of the first error routing area is used as the outlet switch; if the switch where the missed judgment terminal is located is a feeder line outlet end switch, an error remote fault location area or an error line patrol area caused by the missed judgment terminal does not exist;

a2, when a class II remote association terminal is subjected to miss judgment, if a switch where the miss judgment terminal is located is not a feeder outlet end switch, a caused error remote fault location area is a remote area where the switch where the miss judgment terminal is located serves as an outlet switch, and a caused error line patrol area is one and is a field area where the switch where the miss judgment terminal is located serves as the outlet switch; if the switch where the missed judgment terminal is located is a feeder line outlet end switch, an error remote fault location area or an error line patrol area caused by the missed judgment terminal does not exist;

a3, when a class III remote association terminal is misjudged, the caused wrong remote fault positioning area is the remote area of the switch where the misjudged terminal is located as an input switch; if the first wrong routing area is provided with an outgoing switch, other wrong routing areas are all outgoing switches of the first wrong routing area and are used as field areas of the incoming switches;

a4, when the IV remote correlation terminal is misjudged, the wrong remote fault location area is the remote area of the switch where the misjudged terminal is located as the input switch; one error line patrol area is caused, and the switch where the misjudgment terminal is located is used as a field area of the incoming switch;

the rule of the wrong remote fault location area or the wrong line patrol area under the condition of judging the misjudgment or the missed judgment of the local associated terminal is as follows:

b1, when a missed judgment occurs to the I-type local associated terminal, at least one wrong line patrol area is caused, at most two wrong line patrol areas are caused, the first wrong line patrol area is the field area where the switch where the missed judgment terminal is located serves as the outgoing switch, and if the incoming switch of the first wrong line patrol area is not the feeder line outgoing end switch, the second wrong line patrol area is the field area where the incoming switch of the first wrong line patrol area serves as the outgoing switch;

b2, when a type II local association terminal is subjected to missed judgment, one wrong line patrol area is formed, and the wrong line patrol area is the field area where the switch where the missed judgment terminal is located serves as the outgoing switch;

b3, when a type III local association terminal is misjudged, at least one wrong line patrol area is caused, and a plurality of wrong line patrol areas are possible, wherein the first wrong line patrol area is the field area where the switch where the misjudged terminal is located is used as an input switch, and if the first wrong line patrol area is provided with an output switch, other wrong line patrol areas are all the output switches of the first wrong line patrol area and are used as the field areas of the input switch;

b4, when the IV-type local associated terminal is misjudged, one misrouting area is caused, and the misjudgment area is the field area where the switch where the missed judgment terminal is located is used as the incoming switch.

Further, in step S5, analyzing the influence of the fault on each load follows the principle that the circuit breaker and the interconnection switch are both configured with three remote terminals, and follows the principle that the circuit breaker is configured at the outlet end of the feeder line; the following is the law of influence of the fault on each load, and the power failure time of each load of the feeder line is obtained by analyzing the relay protection isolation area, the primary isolation area and the final isolation area of the fault:

c1, if the fault element is on the user branch line, the relay protection is not operated, there is no relay protection isolation area, there is no preliminary isolation area, the final isolation area is the user branch line, the power failure time of the load in the user branch line is t₃The power failure time of the rest loads of the feeder line is 0;

c2, if the fault element is on the branch line, and there is a breaker on the minimum path between the fault element and the power node, and the breaker is on the branch line, the relay protection isolation area is the downstream area of the breaker nearest to the upstream of the fault element, and finally the isolation area is the downstream area of the switch nearest to the upstream of the fault element, at this time, there are four possible cases in the preliminary isolation area:

c21, if the actual remote fault location area is consistent with the correct remote fault location area and a three-remote switch exists between the fault element and the nearest circuit breaker upstream of the fault element, the preliminary isolation area is the downstream area of the three-remote switch;

c22, if the actual remote fault location area is consistent with the correct remote fault location area, and there is no three-remote switch between the fault element and the nearest circuit breaker upstream, there is no preliminary isolation area;

c23, if the actual remote fault location area is not consistent with the correct remote fault location area, and there is a three-remote switch downstream of the nearest breaker upstream of the fault element and upstream of the actual remote fault location area, the preliminary isolation area is the downstream area of the three-remote switch;

c24, if the actual remote fault location area is not consistent with the correct remote fault location area, and there is no three remote switch downstream of the most adjacent breaker upstream of the fault element and upstream of the actual remote fault location area, there is no preliminary isolation area;

if a preliminary isolation region is present,the power off time of the load in the final isolation area is t₁+t₂+t₃(ii) a The power failure time of the load in the preliminary isolation area and not in the final isolation area is t₁+t₂(ii) a The power failure time of the load in the relay protection isolation area and not in the primary isolation area is t₁(ii) a The power failure time of the rest loads is 0;

if the preliminary isolation area does not exist, the power failure time of the load in the final isolation area is t₂+t₃(ii) a The power failure time of the load in the relay protection isolation area and not in the final isolation area is t₂(ii) a The power failure time of the rest loads is 0;

c3, if the fault element does not meet the C2 condition and is on the branch line, and there is a section switch on the minimum path between the fault element and the power node, and the section switch is on the branch line, then the final isolation region is the downstream region of the most adjacent switch upstream of the fault element, and there are two possible conditions for the relay protection isolation region:

c311, if the main feeder line is provided with a circuit breaker which is not on the minimum path between the fault element and the power supply node, and the feeder line has a condition of transferring power, the relay protection isolation area is an area which is downstream of the circuit breaker nearest to the upstream of the fault element and is nearest to the circuit breaker on the main feeder line which is not on the minimum path between the fault element and the power supply node;

c312, if the main feeder line has no circuit breaker which is not on the minimum path between the fault element and the power supply node or the feeder line has no condition of transferring power, the relay protection isolation area is the downstream area of the circuit breaker which is nearest to the upstream of the fault element;

the preliminary isolation region has the following six possible cases:

c321, if a three-remote switch exists upstream of the most upstream incoming switch of the actual remote fault location area and in the relay protection isolation area, finding out the three-remote switch which is most adjacent to the actual remote fault location area; if the three-remote switch is not on the main feeder line, or the three-remote switch is on the main feeder line and the feeder line does not have a condition of power supply transfer, or the three-remote switch is on the main feeder line and the downstream main feeder line does not have the three-remote switch, the primary isolation area is a downstream area of the three-remote switch;

c322, if there is a three-remote switch upstream of the most upstream incoming switch of the actual remote fault location area and in the relay protection isolation area, finding out one such three-remote switch P1 which is most adjacent to the actual remote fault location area; if the three-remote switch P1 is on the main feeder and there is a condition for a transfer of power on the feeder and there are other three-remote switches on the downstream main feeder of the three-remote switch P1, then the preliminary isolation region is the region downstream of the three-remote switch P1 and upstream of the three-remote switch on the nearest main feeder downstream of the three-remote switch;

c323, if a three-remote switch which is upstream of the most upstream incoming switch of the actual remote fault location area and is in the relay protection isolation area exists, finding out one three-remote switch P2 which is most adjacent to the actual remote fault location area; if the three-remote switch P2 is on the main feeder line and the feeder line has the condition of transferring power, and there is no other three-remote switch on the downstream main feeder line of the three-remote switch P2, the primary isolation area is the area from the downstream of the three-remote switch P2 to the edge of the relay protection isolation area;

c324, if there is no three-remote switch upstream of the most upstream incoming switch in the actual remote fault location area and in the relay protection isolation area, and the feeder has a condition of transferring power, and the actual remote fault location area includes a part of area belonging to the main feeder, and there is three-remote switch downstream of the area belonging to the main feeder in the actual remote fault location area and in the relay protection isolation area on the main feeder, then the preliminary isolation area is the area from the upstream of the three-remote switch to the edge of the relay protection isolation area;

c325, if there is no three-remote switch upstream of the most upstream switch in the actual remote fault location area and in the relay protection isolation area, and the feeder has a condition of transferring power, and the actual remote fault location area does not contain an area belonging to the main feeder, and there is three-remote switch upstream of the most upstream switch in the actual remote fault location area and in the relay protection isolation area on the main feeder, then the preliminary isolation area is the area from the upstream of the three-remote switch to the edge of the relay protection isolation area;

c326, if the conditions of C321-C325 are not met, no primary isolation region exists;

if the preliminary isolation area exists, the power failure time of the load in the final isolation area is t₁+t₂+t₃(ii) a The power failure time of the load in the preliminary isolation area and not in the final isolation area is t₁+t₂(ii) a The power failure time of the load in the relay protection isolation area and not in the primary isolation area is t₁(ii) a The power failure time of the rest loads is 0;

c4, if the faulty element is on the branch line and there is no switching element on the branch line upstream of the faulty element, or the faulty element is on the main feeder, then there are two possible cases of the final isolation zone:

c411, if the feeder has a condition of transferring power supply and a switch which is not on the minimum path of the fault element and the power supply node and is closest to the fault element is arranged on the main feeder, the final isolation area is an area which is upstream of the switch and is downstream of the closest switch upstream of the fault point;

c412, if the feeder line has no condition of transferring power supply, or the feeder line has the condition of transferring power supply but the main feeder line does not have a switch which is not on the minimum path of the fault element and the power supply node and is closest to the fault element, the final isolation area is an area downstream of the closest switch upstream of the fault point;

at this time, the relay protection isolation area has the following two possible situations:

c421, if the main feeder line is provided with a breaker which is not on the minimum path between the fault element and the power supply node, and the feeder line has a condition of transferring power, the relay protection isolation area is an area which is downstream of the breaker nearest to the upstream of the fault element and is nearest to the breaker on the main feeder line and is not on the minimum path between the fault element and the power supply node;

c422, if the main feeder line has no circuit breaker which is not on the minimum path between the fault element and the power supply node or the feeder line has no condition of transferring power, the relay protection isolation area is the downstream area of the circuit breaker which is nearest to the upstream of the fault element;

there are several possible cases of the preliminary isolation region at this time:

c431, if the main feeder in the relay protection isolation area is provided with the three-remote switch at the upstream of the area belonging to the main feeder in the actual remote fault location area, and the feeder does not have the condition of power transfer, the primary isolation area is a downstream area of the three-remote switch at the upstream of the area most adjacent to the main feeder in the actual remote fault location area on the main feeder in the relay protection isolation area;

c432, if a three-remote switch at the upstream of the area belonging to the main feeder line in the actual remote fault location area is arranged on the main feeder line in the relay protection isolation area, and the feeder line has a condition of power transfer, but no three-remote switch at the downstream of the area belonging to the main feeder line in the actual remote fault location area is arranged on the main feeder line in the relay protection isolation area, the primary isolation area is an area from the downstream of the three-remote switch at the upstream of the area most adjacent to the main feeder line in the actual remote fault location area to the edge of the relay protection isolation area on the main feeder line in the relay protection isolation area;

c433, if the feeder has a condition of power supply transfer, and the main feeder in the relay protection isolation area is provided with a three-remote switch at the upstream of the area belonging to the main feeder in the actual remote fault location area, and the main feeder in the relay protection isolation area is provided with a three-remote switch at the downstream of the area belonging to the main feeder in the actual remote fault location area, the primary isolation area is the downstream of the three-remote switch at the upstream of the area nearest to the main feeder in the actual remote fault location area on the main feeder in the relay protection isolation area, and the upstream of the three-remote switch at the downstream of the area nearest to the main feeder in the actual remote fault location area on the main feeder in the relay protection isolation area;

c434, if the feeder has a condition of power supply transfer, and the main feeder in the relay protection isolation area has a three-remote switch downstream of the area belonging to the main feeder in the actual remote fault location area, but the main feeder in the relay protection isolation area does not have a three-remote switch upstream of the area belonging to the main feeder in the actual remote fault location area, the primary isolation area is an area from the upstream of the three-remote switch closest to the downstream of the area belonging to the main feeder in the actual remote fault location area to the edge of the relay protection isolation area on the main feeder in the relay protection isolation area;

c435, if the conditions of C431-C434 are not met, no primary isolation area exists;

the calculation formula of the power shortage amount of each load in the simulation is as follows:

wherein, ens_iFor the power shortage of the ith load in the fault simulation, T_iFor the time of power failure of the ith load in the present fault simulation, P_iIs the average load of the ith load.

Further, in step S6, the simulation time is updated by the following equation:

t＝t+Δt₁+Δt₂/8760；

if the simulation time t is greater than or equal to the set simulation time limit, go to step S7, otherwise go to step S3.

Further, in step S7, the reliability index of each load includes the annual failure rate λ of the load i_iAverage power failure duration γ of load i_iAnnual average fault power failure time U of load i_iDesired power shortage ENS of load i_iThe specific calculation method is as follows:

annual failure rate λ of load i_iDividing the power failure frequency of the load i in the simulation time by the simulation year;

average outage duration γ for load i_iDividing the sum of the times of power failure of the load i in the simulation time by the power failure times of the load i in the simulation time;

mean time of year fault power failure time U of load i_iDividing the sum of the times of multiple power failures of the load i in the simulation time by the simulation year;

expected power shortage ENS of load i_iThe average load of the load i is multiplied by the annual average fault outage time of the load i.

Further, in step S8, the reliability index of the distribution grid system is calculated according to the evaluation rule of the power supply reliability of the power supply system, including the average system outage time SAIDI, the average system outage frequency SAIFI, the average outage time CAIDI of the outage user, the power supply reliability ASAI, and the expected power shortage amount ENS.

According to the technical scheme, the embodiment of the invention has the following advantages:

the invention provides a practical reliability analysis method of a complex power distribution network information physical system, which makes up the defect that the conventional reliability analysis method of the power distribution network information physical system does not consider the influence of different types of power distribution automatic terminals, summarizes and summarizes the fault isolation time and the rule of fault influence analysis.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without inventive exercise.

Fig. 1 to 6 are schematic diagrams of complex power distribution network structures provided by the embodiment of the invention.

In the power distribution network shown in fig. 1 to 6, the symbols of the circuit breaker, the section switch, the interconnection switch, the load, the fuse and the transformer are shown in the legend of each figure, the configuration of the automatic terminals of each section switch and the circuit breaker is shown in the description of each figure, and the terminals which are not judged or judged by mistake are shown in the parenthesis of the switch positions of the terminals in each figure. Broken line arrow symbols in the figure represent the positions of fault points of the power distribution network physical system so as to explain the fault isolation time calculation and fault mode consequence analysis process of fault elements.

Fig. 1 is a schematic diagram provided in an embodiment of the present invention to illustrate a simplified principle of a power distribution network topology.

Fig. 2 is a schematic diagram for explaining an actual remote fault location area according to an embodiment of the present invention.

Fig. 3 is a schematic diagram for explaining an actual line patrol area according to an embodiment of the present invention.

Fig. 4, fig. 5, and fig. 6 are schematic diagrams of 3 complex power distribution network structures for explaining load blackout time analysis according to an embodiment of the present invention.

Fig. 7 is a flowchart of the practical reliability analysis method for the complex power distribution network cyber-physical system in the embodiment of the present invention.

Detailed Description

The embodiment provides a practical reliability analysis method for a complex power distribution network information physical system, which considers the influence of the function configuration of a power distribution network automation terminal on the power supply reliability, is suitable for power distribution network physical systems with complex grid structures and power distribution network information systems in multiple communication modes, and provides a practical model and a practical method for more accurately evaluating the power supply reliability of the power distribution network information physical system.

In order to make the objects, features and advantages of the present invention more obvious and understandable, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the embodiments described below are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example (b):

as shown in fig. 7, the method for analyzing the practical reliability of the complex power distribution network information physical system includes the following steps:

the elements of the power distribution network physical system comprise lines, switch elements, transformers and loads, wherein the switch elements comprise circuit breakers, section switches, interconnection switches and fuses;

as shown in fig. 1, fig. 1a is a simplified power distribution network topology, and fig. 1b is a simplified power distribution network topology of fig. 1 a.

the reliability parameters universal to the automation terminals in the power distribution network information system comprise: the fault rate and the average repair time of a fault indication module of each type of terminal in the first remote terminal, the second remote terminal and the third remote terminal which are all 3 types of terminals, the terminal on-line rate of each type of remote terminal in the second remote terminal, the third remote terminal and the 2 types of remote terminals, and the fault rate of an electric operation module of the third remote terminal;

the method for extracting the state of the current physical system by utilizing the sequential Monte Carlo method calculates and simulates the normal working time delta t of all elements in the physical system of the power distribution network by the following formula₁(year):

Δt₂＝-r×ln；

it follows that the current state of the physical system is that all physical elements are operating normally at Δ t₁After that time, the component k fails, and it takes time Δ t to repair the failure of the component k this time₂；

assigning a random number to each remote terminal element for extracting whether a remote terminal can normally complete the fault indication(ii) a If the random number is greater than or equal to the failure probability P of the fault indication module of the remote terminal₀₁If not, the remote terminal can not complete the fault indication normally;

After sampling the physical system and the automatic terminals of the power distribution network by using a Monte Carlo method, the states of all the automatic terminals in the information system are obtained, and the method specifically comprises the following steps:

the analysis of the fault isolation time is related to the states of all associated terminals of the fault element of the physical system, and is also related to the type of the switch closest to the fault element of the physical system and the type of the terminal of the switch configuration; the analysis of the fault isolation time follows the principle that the breaker and the interconnection switch are both provided with three remote terminals and follows the principle that the feeder line outlet end is provided with the breaker;

defining the time of the switch action of the remote control configuration three-remote terminal as t₁Defining the fault isolation time as t₂Defining the time for repairing the fault as t₃(ii) a Time to fail over is t₃Is taken as Δ t obtained by sampling the failed element of the physical system in step S3₂(ii) a Time t of fault isolation₂Including the time t of the journey of the worker to the faulty feeder₂₁Time t for locating fault₂₂And field operation switch time t₂₃The calculation formula is as follows:

t₂＝t₂₁+t₂₂+t₂₃；

t₂₂＝t₂₂₁+t₂₂₂；

t₂₂₁＝n_yiyaot_yiyao；

t₂₂₂＝l_patrolt_patrol；

t₂₃＝n_manualt_manual；

defining the correct remote fault location area as: an area enclosed by all remote terminals in closest proximity to the failed component; the remote terminal which is closest to the fault element means that no other remote terminal exists on the minimum path between the remote terminal and the fault point; if all the remote associated terminals of the fault point are in the first state in the simulation, the actual remote fault location area is consistent with the correct remote fault location area; if all the remote associated terminals of the fault point are not in the first state in the simulation, the actual remote fault location area is equal to the correct remote fault location area plus the wrong remote fault location area; in this embodiment, as shown in fig. 2, the correct remote fault location area is area C.

a remote terminal that is on the smallest path between the point of failure and the power supply node and has no other remote terminals on the smallest path between it and the point of failure, referred to as a class I remote association terminal, such as the terminal of switch S10 in fig. 2; a remote terminal having a class I remote association terminal, referred to as a class II remote association terminal, on the smallest path between the fault point and the power supply node and the smallest path between the fault point and the power supply node, such as the terminal of the switch S11 in fig. 2; remote terminals which are not located on the minimum path between the fault point and the power supply node and have no other remote terminals on the minimum path between the fault point and the remote terminal are called type III remote association terminals, such as terminals of switches S1-S3 in FIG. 2; the remote terminal which is not positioned on the minimum path between the fault point and the power supply node and has a remote association terminal on the minimum path between the fault point and the remote association terminal is called a type IV remote association terminal, such as terminals of switches S4-S9 in FIG. 2;

defining a remote area as an area enclosed by the remote terminals and without other remote terminals inside, such as areas a-Q in fig. 2; defining a field area as an area surrounded by terminals and without any terminals inside, such as areas A-Q in FIG. 3; the incoming switch defining a zone is a switch at the boundary of the zone, where the direction of the current flowing through the switch is directed into the zone outside the zone, e.g. the incoming switch of zone C in fig. 2 is switch S10; the outgoing switches defining the zone are switches located at the zone boundary and the direction of the power flow flowing through the switches is outside the pointing region in the zone, for example, the outgoing switches of zone C in fig. 2 are switches S1 to S3; there may be only one in switch, one out switch, or multiple in switches in one region, for example, there is no out switch in region E, F, G, K, L, M, P, Q, there is only one out switch in region B, I, J, and there are multiple out switches in other regions in fig. 2;

a1, when a missed judgment occurs on a class I remote association terminal, if a switch where the missed judgment terminal is located is not a feeder outlet switch, a resulting wrong remote fault location area is a remote area where the switch where the missed judgment terminal is located is used as an outlet switch, at least one wrong routing area is caused, at most two wrong routing areas are caused, a first wrong routing area is a field area where the switch where the missed judgment terminal is located is used as an outlet switch, if an inlet switch of the first wrong routing area is not an outlet switch of a feeder, a second wrong routing area is a field area where an inlet switch of the first wrong routing area is used as an outlet switch, for example, the terminal missed judgment of the switch S10 in fig. 2, a resulting wrong remote fault location area is an area B, and resulting wrong routing areas are areas a and B; if the switch where the missed judgment terminal is located is a feeder line outlet end switch, an error remote fault location area or an error line patrol area caused by the missed judgment terminal does not exist;

a2, when a class II remote association terminal is determined to be missing, if the switch where the missing determination terminal is located is not the feeder outlet switch, the resulting remote fault location area is the remote area where the switch where the missing determination terminal is located is used as the outlet switch, and one resulting fault routing area is the field area where the switch where the missing determination terminal is located is used as the outlet switch, for example, the terminal missing determination of the switch S11 in fig. 2, the resulting remote fault location area is area a, and the resulting fault routing area is area a; if the switch where the missed judgment terminal is located is a feeder line outlet end switch, an error remote fault location area or an error line patrol area caused by the missed judgment terminal does not exist;

a3, when a class III remote association terminal is misjudged, the caused wrong remote fault positioning area is the remote area of the switch where the misjudged terminal is located as an input switch; if the first wrong routing area has a switch, other wrong routing areas are all the switches out of the first wrong routing area as the field areas of the switches, for example, the terminal of the switch S3 in FIG. 2 is misjudged, the caused wrong remote fault location area is area D, and the caused wrong routing areas are areas D, E and J;

a4, when the IV remote correlation terminal is misjudged, the wrong remote fault location area is the remote area of the switch where the misjudged terminal is located as the input switch; one of the caused wrong line patrol areas is a field area where the switch where the misjudged terminal is located is used as an incoming switch, for example, the terminal misjudgment of the switch S5 in fig. 2 causes a wrong remote fault location area to be an area N, and causes a wrong line patrol area to be an area N;

b1, when a missed judgment occurs at the type I local association terminal, there is at least one wrong line patrol area, and there are at most two wrong line patrol areas, where the first wrong line patrol area is a field area where the switch where the missed judgment terminal is located is used as an outgoing switch, and if the incoming switch of the first wrong line patrol area is not the feeder outgoing line end switch, the second wrong line patrol area is a field area where the incoming switch of the first wrong line patrol area is used as an outgoing switch, for example, the switch S10 in fig. 3 is missed judgment, and the wrong line patrol areas caused are areas a and B;

b2, when a missed judgment occurs at the class II local association terminal, one wrong routing area is caused, which is a field area where the switch where the missed judgment terminal is located is used as an outgoing switch, for example, the switch S11 in fig. 3 is missed judgment, and the caused wrong routing area is area a;

b3, when a misjudgment occurs in the class III local association terminal, there may be at least one or more misrouting areas, where the first misrouting area is a field area where the switch where the misjudgment terminal is located is used as an entry switch, and if there is an exit switch in the first misrouting area, all exit switches in other misrouting areas where other misrouting areas are the first misrouting area are used as field areas where entry switches are located, for example, the switch S3 in fig. 3 misjudges, and the misrouting areas caused are areas D, E and J;

b4, when a misjudgment occurs at the type IV local association terminal, there is one misrouting area, which is a field area where the switch where the missed judgment terminal is located is used as an entry switch, for example, the switch S5 in fig. 3 misjudges, and the misrouting area is an area N.

analyzing the influence of the fault on each load according to the principle that the breaker and the interconnection switch are both provided with three remote terminals and the principle that the feeder line outlet end is provided with the breaker; the following is the law of influence of the fault on each load, and the power failure time of each load of the feeder line is obtained by analyzing the relay protection isolation area, the primary isolation area and the final isolation area of the fault:

c2, if the fault element is on the branch line, and there is a breaker on the minimum path between the fault element and the power node, and the breaker is on the branch line, the relay protection isolation area is the downstream area of the breaker nearest to the upstream of the fault element, and the final isolation area is the downstream area of the switch nearest to the upstream of the fault element, for example, in the case shown in fig. 4, the relay protection isolation area is area a, and the final isolation area is area C; now, the preliminary isolation region has the following four possible cases:

c23, if the actual remote fault location area is not consistent with the correct remote fault location area and there is a three remote switch downstream of the most adjacent breaker upstream of the fault element, upstream of the actual remote fault location area, then the preliminary isolation area is the downstream area of the three remote switch, e.g. in the case of fig. 4, the preliminary isolation area is area B;

if the preliminary isolation area exists, the power failure time of the load in the final isolation area is t₁+t₂+t₃(ii) a The power failure time of the load in the preliminary isolation area and not in the final isolation area is t₁+t₂(ii) a The power failure time of the load in the relay protection isolation area and not in the primary isolation area is t₁(ii) a The rest load has a power failure time of 0, for example, in the case shown in FIG. 4, the power failure time of load LD6 is t₁+t₂+t₃(ii) a The power failure time of the load LD5 is t₁+t₂(ii) a The power failure time of the load LD4 is t₁；

If the preliminary isolation area does not exist, the power failure time of the load in the final isolation area is t₂+t₃(ii) a In the relay protection isolation region,And the power failure time of the load not in the final isolation area is t₂(ii) a The power failure time of the rest loads is 0;

c3, if the fault element does not meet the C2 condition and there is a section switch on the branch line and there is a minimum path between the fault element and the power node and the section switch is on the branch line, then the final isolation area is the downstream area of the most upstream adjacent switch of the fault element, for example, in the case of fig. 5, the final isolation area is area C, and then there are two possible situations for the relay protection isolation area:

c311, if there is a circuit breaker on the main feeder that is not on the minimum path between the faulty element and the power supply node, and the feeder has a condition of transferring power, the relay protection isolation region is a region downstream of the circuit breaker nearest to the upstream of the faulty element, and the region upstream of the circuit breaker nearest to the faulty element on the main feeder that is not on the minimum path between the faulty element and the power supply node, for example, in the case shown in fig. 5, the relay protection isolation region is region a;

the preliminary isolation region has the following six possible cases:

and C321, if the three-remote switch which is upstream of the most upstream incoming switch of the actual remote fault location area and is in the relay protection isolation area exists, finding out one three-remote switch which is most adjacent to the actual remote fault location area. If the three-remote switch is not on the main feeder line, or the three-remote switch is on the main feeder line and the feeder line does not have a condition of power supply transfer, or the three-remote switch is on the main feeder line and the downstream main feeder line does not have the three-remote switch, the primary isolation area is a downstream area of the three-remote switch;

c322, if there is a three-remote switch upstream of the incoming switch most upstream of the actual remote fault location area and within the relay protection isolation area, find one such three-remote switch P1 that is most adjacent to the actual remote fault location area. If the three-remote switch P1 is on the main feed line and there is a condition for a transfer of power to the feed line and there are other three-remote switches on the downstream main feed line of the three-remote switch P1, then the preliminary isolation area is the area downstream of the three-remote switch P1 and upstream of the three-remote switch on the nearest main feed line downstream of the three-remote switch, e.g., in the case shown in fig. 5, the preliminary isolation area is area B;

c323, if there is a three-remote switch upstream of the incoming switch most upstream of the actual remote fault location area and within the relay protection isolation area, find out one such three-remote switch P2 that is most adjacent to the actual remote fault location area. If the three-remote switch P2 is on the main feeder line and the feeder line has the condition of transferring power, and there is no other three-remote switch on the downstream main feeder line of the three-remote switch P2, the primary isolation area is the area from the downstream of the three-remote switch P2 to the edge of the relay protection isolation area;

if the preliminary isolation area exists, the power-off time of the load in the final isolation area ist₁+t₂+t₃(ii) a The power failure time of the load in the preliminary isolation area and not in the final isolation area is t₁+t₂(ii) a The power failure time of the load in the relay protection isolation area and not in the primary isolation area is t₁(ii) a The rest load has a power failure time of 0, for example, in the case shown in FIG. 5, the power failure time of load LD7 is t₁+t₂+t₃(ii) a The power failure time of the loads LD2, LD3, LD4 and LD6 is t₁+t₂(ii) a The power failure time of the load LD1 is t₁；

c411, if the feeder has a condition of transferring power and there is a switch on the main feeder that is not on the minimum path of the faulty element and the power supply node, closest to the faulty element, then the final isolation area is the area upstream of the switch, upstream of the fault point, downstream of the closest switch, for example in the case of fig. 6, the final isolation area is area C;

c421, if there is a circuit breaker on the main feeder that is not on the minimum path between the faulty element and the power node, and the feeder has a condition of transferring power, the relay protection isolation region is a region downstream of the circuit breaker nearest to the upstream of the faulty element, and the region upstream of the circuit breaker nearest to the faulty element on the main feeder that is not on the minimum path between the faulty element and the power node, for example, in the case shown in fig. 6, the relay protection isolation region is region a;

c433, if the feeder has a condition of transferring power, and the main feeder in the relay protection isolation area has a three-remote switch on the upstream of the area belonging to the main feeder in the actual remote fault location area, and the main feeder in the relay protection isolation area has a three-remote switch on the downstream of the area belonging to the main feeder in the actual remote fault location area, the preliminary isolation area is the downstream of the three-remote switch on the main feeder in the relay protection isolation area closest to the upstream of the area belonging to the main feeder in the actual remote fault location area, and the upstream of the three-remote switch on the main feeder in the relay protection isolation area closest to the downstream of the area belonging to the main feeder in the actual remote fault location area, for example, in the case shown in fig. 6, the preliminary isolation area is area B;

if the preliminary isolation area exists, the power failure time of the load in the final isolation area is t₁+t₂+t₃(ii) a The power failure time of the load in the preliminary isolation area and not in the final isolation area is t₁+t₂(ii) a The power failure time of the load in the relay protection isolation area and not in the primary isolation area is t₁(ii) a The rest load has a power failure time of 0, for example, in the case shown in FIG. 6, the power failure time of load LD4 is t₁+t₂+t₃(ii) a The power failure time of the loads LD2, LD3 and LD5 is t₁+t₂(ii) a The power failure time of the loads LD1 and LD6 is t₁；

wherein, ens_iFor the power shortage of the ith load in the fault simulation, T_iFor the time of power failure of the ith load in the present fault simulation, P_iAverage load of i-th load。

S6, updating the simulation time by the following formula:

t＝t+Δt₁+Δt₂/8760；

if the simulation time t is greater than or equal to the set simulation time limit, performing step S7, otherwise jumping to step S3;

s7, counting the reliability indexes of each load;

the reliability index of each load comprises the annual fault rate lambda of the load i_iAverage power failure duration γ of load i_iAnnual average fault power failure time U of load i_iDesired power shortage ENS of load i_iThe specific calculation method is as follows:

S8, calculating and outputting reliability indexes of the power distribution network system according to power supply reliability evaluation regulations of the power supply system, wherein the reliability indexes of the power distribution network system comprise system average power failure time SAIDI, system average power failure frequency SAIFI, power failure user average power failure time CAIDI, power supply reliability ASAI and expected power shortage quantity ENS; and planning or modifying the power distribution network in an auxiliary mode according to the output reliability index.

The above-mentioned embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the same; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims

1. The practical reliability analysis method of the complex power distribution network information physical system is characterized by comprising the following steps of:

s7, counting the reliability indexes of each load;

2. The method for analyzing the practical reliability of the cyber-physical system of the complex power distribution network according to claim 1, wherein in the step S1, the elements of the cyber-physical system include lines, switching elements, transformers, and loads, wherein the switching elements include circuit breakers, sectionalizing switches, tie switches, and fuses;

each row of the simplified power distribution network physical system element topological connection relation matrix Brancha represents a section of simplified line, the first column is a first node of the section of simplified line, the second column is a last node of the section of simplified line, the third column is the type of the section of simplified line, and the fourth column is the length of the section of simplified line; the nodes comprise a power supply node and a load node, wherein the power supply node is a variable-low side of a 10kV transformer substation, and the load node is a node with a user branch line consisting of a fuse, a line, a transformer and a load at the downstream; the power flow direction of each simplified line section is from the first node to the last node; the simplified line types comprise 6 types, namely pure lines, a pure line section connected behind a switch without terminal configuration, a pure line section connected behind a remote switch, a pure line section connected behind a two-remote switch, a pure line section connected behind a three-remote switch, and a pure line section connected behind a breaker; the simplified topological connection relation matrix of the elements of the physical system of the power distribution network is obtained by simplifying the actual power grid topology, and the simplifying principles are two:

3. The method for analyzing the practical reliability of the cyber-physical system of the complex distribution network according to claim 1, wherein in the step S2, the reliability parameters common to the automation terminals in the cyber-physical system of the complex distribution network include: the fault rate and the average repair time of a fault indication module of each type of terminal in the first remote terminal, the second remote terminal and the third remote terminal which are all 3 types of terminals, the terminal on-line rate of each type of remote terminal in the second remote terminal, the third remote terminal and the 2 types of remote terminals, and the fault rate of an electric operation module of the third remote terminal;

4. The method of claim 1, wherein in step S3, the method for extracting the current state of the physical system by using the sequential monte carlo method calculates and simulates the normal operation time Δ t of all elements in the physical system of the distribution network according to the following formula₁：

then selecting the physical system component k with the shortest normal working time in the simulation, defining the fault point in the simulation as the component k, and calculating and simulating the fault repairing time delta t of the component k according to the following formula₂：

Δt₂＝-r×ln；

giving three random numbers to each three-remote terminal element for extracting whether the three-remote terminal can normally complete fault indication, whether the electric operation module can normally act and whether the three-remote terminal is on line; if the first random number is greater than or equal to the failure probability P of the fault indication module of the three-remote terminal₀₃₁If the second random number is larger than or equal to the failure probability P of the electric operation module of the three-remote terminal, the three-remote terminal can normally complete the fault indication, otherwise, the three-remote terminal cannot normally complete the fault indication, and if the second random number is larger than or equal to the failure probability P of the electric operation module of the three-remote terminal₀₃₂If the third random number is larger than or equal to the third remote terminal, the three remote terminal electric operating module can normally act, otherwise, the three remote terminal electric operating module can not normally act, and if the third random number is larger than or equal to the third remote terminal, the terminal is at the position of the third remote terminalIf the line rate is lower than the preset threshold, the three-remote terminal is on line, otherwise, the three-remote terminal is off line;

5. The practical reliability analysis method for the information physical system of the complex power distribution network according to claim 4, wherein the Monte Carlo method is used to sample the physical system of the power distribution network and the automation terminals to obtain the states of all the automation terminals in the information system, and the method specifically comprises the following steps:

6. The method for analyzing the practical reliability of the cyber-physical system of the complex power distribution network according to claim 1, wherein in the step S4, the analysis of the fault isolation time is related to the states of all the associated terminals of the faulty component of the physical system, and also related to the type of the switch nearest to the faulty component of the physical system and the type of the terminal of the switch configuration; the analysis of the fault isolation time follows the principle that the breaker and the interconnection switch are both provided with three remote terminals and follows the principle that the feeder line outlet end is provided with the breaker;

t₂＝t₂₁+t₂₂+t₂₃；

t₂₂＝t₂₂₁+t₂₂₂；

t₂₂₁＝n_yiyaot_yiyao；

t₂₂₂＝l_patrolt_patrol；

t₂₃＝n_manualt_manual；

all remote associated terminals of the fault point are classified into four categories, specifically as follows:

all local associated terminals of a fault point are classified into four categories: a remote terminal which is on the minimum path between the fault point and the power node and has no other terminal on the minimum path between the fault point and the remote terminal is called as an I-type local association terminal; a remote terminal which is on the minimum path between the fault point and the power supply node and has no other terminal except an I-type local association terminal is called as a II-type local association terminal; the remote terminal is not positioned on the minimum path between the fault point and the power supply node and has no other terminal on the minimum path between the fault point and the remote terminal, and is called as a type III local association terminal; the remote terminal which is not positioned on the minimum path between the fault point and the power supply node and is provided with a remote terminal and no other terminal except the remote terminal is called as a type IV local association terminal;

7. The method for analyzing the reliability of the physical information system of the power distribution network under the distribution automation condition as claimed in claim 1, wherein in the step S5, the analysis of the influence of the fault on each load follows the principle that the breaker and the interconnection switch are both configured with three remote terminals and follows the principle that the breaker is configured at the outlet end of the feeder line; the following is the law of influence of the fault on each load, and the power failure time of each load of the feeder line is obtained by analyzing the relay protection isolation area, the primary isolation area and the final isolation area of the fault:

the preliminary isolation region has the following six possible cases:

wherein, ens_iSimulating the fault for the ith loadIn a shortage of power, T_iFor the time of power failure of the ith load in the present fault simulation, P_iIs the average load of the ith load.

8. The method for analyzing reliability of cyber physical systems of a power distribution network under distribution automation conditions as claimed in claim 1, wherein in the step S6, the simulation time is updated by the following formula:

t＝t+Δt₁+Δt₂/8760；

9. The reliability analysis method for the cyber-physical system of the power distribution network under the distribution automation condition as recited in claim 1, wherein the reliability index of each load includes an annual failure rate λ of a load i in step S7_iAverage power failure duration γ of load i_iAnnual average fault power failure time U of load i_iDesired power shortage ENS of load i_iThe specific calculation method is as follows:

10. The method according to claim 1, wherein in step S8, the reliability index of the distribution network system is calculated according to the evaluation rule of the power supply reliability of the power supply system, and includes average system outage time SAIDI, average system outage frequency SAIFI, average outage time CAIDI of the outage users, power supply reliability ASAI, and expected power shortage amount ENS.