1. A functional recovery decision-making method of an interdependent hydroelectric system based on a flexible city is characterized by comprising the following steps:

s1, initialization data: the data at least comprises topological structures and components of the water supply system and the electric power system, initial physical damage conditions of the components of the water supply system and the electric power system, the quantity of maintenance resources for maintaining the damaged components, and a dependency database of the water supply system and the electric power system;

s2, randomly generating sequences of a plurality of damage component serial numbers based on the initial physical damage condition of the component obtained in the step S1, wherein the sequences are used as chromosomes, namely an initial population, setting an identity code of a chromosome slice and an information pool of the integral hydroelectric function level under the corresponding damage state, and setting the iteration times of a genetic algorithm;

s3, judging whether the identity code of the chromosome slice to be evaluated already exists in the information pool:

if the water-electricity integral function level exists, the water-electricity integral function level in the information pool is directly called;

otherwise, calculating by using a function analysis method to obtain the integral function level of the hydropower, namely performing direct current power flow analysis on the power system and performing hydraulic analysis calculation on the water supply system; calculating the identity code of the chromosome slice, storing the identity code and the integral hydropower function level into an information pool, and acquiring the time accumulated function loss of the hydropower system according to the time step on the basis of the integral hydropower function level of the chromosome slice, wherein the time accumulated function loss is the chromosome adaptive function;

and S4, operating the chromosome by using at least selection, intersection and mutation genetic operators to obtain the next generation chromosome, and selecting the optimal chromosome based on the adaptive function value if the iteration times are reached.

2. The method according to claim 1, wherein in step S1, the topology of the water supply system and the power system is a geometric figure composed of nodes and edges, wherein the nodes and edges are members of the water supply system and the power system; in the water supply system, the node is at least a water pump or a reservoir, and the side is a water supply pipeline; in the power system, the nodes are at least substations or power stations, and the edges are power transmission lines.

3. The method according to claim 2, wherein in the step S1, the dependency database of the water supply system and the power system refers to a substation or a power station in the power system corresponding to a water pump in the water supply system, wherein the corresponding relationship refers to that the water pump needs power to maintain normal operation, and if the substation or the power station in the corresponding area is damaged, the water pump cannot be supplied with power, and the water pump cannot be operated.

4. The method according to claim 1, wherein in the step S1, the initial physical damage conditions of the components of the water supply system and the power system are divided into a first damage state, a second damage state, a third damage state, a fourth damage state and a fifth damage state in sequence based on the damage degree from low to high; the maintenance resources refer to the counts of single construction teams equipped with corresponding maintenance tools, and the water supply system and the power system are assumed to have corresponding maintenance resources respectively and are not universal; assuming that a damaged component corresponds to a need for a repair resource, repair time increases with the severity of the damage to the component.

5. The method according to claim 1, wherein in step S2, a chromosome is a sequence consisting of the number strings of lesion component numbers 1, 2, 3, …, N being the number of lesion components; one chromosome slice corresponds to a hydroelectric system in a corresponding damage state, wherein the damage component is a digital string consisting of serial numbers of components from 1 st to nth of the corresponding chromosome, and N is more than or equal to 1 and less than or equal to N; the identity code of a chromosome slice is a calculated value obtained by taking each serial number in the slice as the index of a number 2 and then summing; the pool of information is a database containing identity codes and hydroelectric function levels of all chromosome slices that have been subjected to functional analysis.

6. The method according to claim 1, wherein the step S2, the hydropower overall function level of a chromosome slice refers to the functional analysis of the hydropower system represented by the chromosome slice, and the steps are as follows:

firstly, performing direct current flow analysis on the power system, and judging whether a water pump in a water supply system can normally operate according to the power supply condition of each power supply service area;

then, hydraulic analysis of the water supply system is performed.

7. The method of claim 1, wherein in the step S3, the time step is the shortest maintaining time for which the overall function level of the hydroelectric system is kept unchanged; the number of components that function normally in a hydroelectric system increases gradually as maintenance work progresses; and if the component repair is completed within a certain time step, performing function analysis again according to the new topological structure of the hydroelectric system to give a new function level, or else, using the function level in the last step for a long time.

8. The method according to claim 1, wherein in step S3, the overall functional level of the hydropower system is that the hydropower system is composed of different service areas, the functional level of the hydropower supply of each service area is obtained through functional analysis, and then the functional level of the overall hydropower system is obtained according to the weighted average of the number of users in the different service areas, wherein the functional level is measured by the percentage of the users meeting the water demand or the electricity demand, 100% represents complete satisfaction, and 0 represents no water supply or power supply at all.

9. The method of claim 8, wherein the overall functional level of the hydropower is calculated as follows:

in the formula (I), the compound is shown in the specification,andthe integral function levels of the water supply system and the power system on the t day are respectively;andthe functional levels of the ith service area of the water supply system on the t day and the jth service area of the power system on the t day are respectively;andweights of the ith service area of the water supply system and the jth service area of the electric power system are respectively set;andthe number of users in the ith service area of the water supply system and the jth service area of the electric power system are respectively.

10. The method of claim 9, wherein in step S3, the cumulative loss of function over time for the hydro-electric system is calculated by summing the total number of days to recover minus the cumulative daily level of function over the recovery period, as follows:

in the formula，L^wAnd L^pThe accumulated function loss values of the water supply system and the electric power system are respectively, namely the fitness function of the chromosome; t is^wAnd T^pTotal time for restoration of the water supply system and the electric power system respectively; t is the day during recovery.

Background

Every time an earthquake disaster happens, the earthquake disaster has great influence on the economic operation and social activities of the city. The flexible city is a new paradigm in the field of disaster prevention and reduction, and requires the city to have the capability of resisting and rapidly recovering from disasters. Critical infrastructure systems, an essential component of the city, need to be restored to normal functional levels in as short a time as possible after a disaster, thereby providing vital support for social, economic and governmental activities in the city. In recent years, people gradually recognize that key infrastructure systems are interdependent, for example, a water pump in a water supply system needs to be powered by an electric system to maintain normal operation, a burst of a water pipe in the water supply system affects normal operation of a traffic system, and the like.

However, at present, in consideration of the post-disaster recovery decision of the water supply system and the power system which have a mutual dependency relationship, because the recovery of the water supply system and the power supply system needs to be integrally optimized, rather than the recovery decision of the two systems, the number of decision variables in the optimization process is doubled, and the time required by optimization is increased nonlinearly, so that the recovery decision is difficult to meet the time urgency requirement of the post-disaster recovery, and the method cannot be applied to the actual disaster emergency.

Disclosure of Invention

In order to overcome the defects of the technology, the invention provides a functional recovery decision method of a hydroelectric system based on interdependence of a flexible city.

The technical scheme adopted by the invention for overcoming the technical problems is as follows:

a functional recovery decision-making method of an interdependent hydroelectric system based on a flexible city comprises the following steps:

s1, initialization data: the data at least comprises topological structures and components of the water supply system and the electric power system, initial physical damage conditions of the components of the water supply system and the electric power system, the quantity of maintenance resources for maintaining the damaged components, and a dependency database of the water supply system and the electric power system;

s2, randomly generating sequences of a plurality of damage component serial numbers based on the initial physical damage condition of the component obtained in the step S1, wherein the sequences are used as chromosomes, namely an initial population, setting an identity code of a chromosome slice and an information pool of the integral hydroelectric function level under the corresponding damage state, and setting the iteration times of a genetic algorithm;

s3, judging whether the identity code of the chromosome slice to be evaluated already exists in the information pool:

if the water-electricity integral function level exists, the water-electricity integral function level in the information pool is directly called;

otherwise, calculating by using a function analysis method to obtain the integral function level of the hydropower, namely performing direct current power flow analysis on the power system and performing hydraulic analysis calculation on the water supply system; calculating the identity code of the chromosome slice, storing the identity code and the integral hydropower function level into an information pool, and acquiring the time accumulated function loss of the hydropower system according to the time step on the basis of the integral hydropower function level of the chromosome slice, wherein the time accumulated function loss is the chromosome adaptive function;

and S4, operating the chromosome by using at least selection, intersection and mutation genetic operators to obtain the next generation chromosome, and selecting the optimal chromosome based on the adaptive function value if the iteration times are reached.

Further, in step S1, the topology of the water supply system and the power system is a geometric figure composed of nodes and edges, wherein the nodes and the edges are members of the water supply system and the power system; in the water supply system, the node is at least a water pump or a reservoir, and the side is a water supply pipeline; in the power system, the nodes are at least substations or power stations, and the edges are power transmission lines.

In step S1, the dependency database of the water supply system and the power system refers to a substation or a power plant in the power system corresponding to a water pump in the water supply system, where the corresponding relationship refers to that the water pump needs power to maintain normal operation, and if the substation or the power plant in the corresponding area is damaged, the water pump cannot be supplied with power, and the water pump cannot operate.

Further, in the step S1, the initial physical damage conditions of the components of the water supply system and the power system are divided into a first damage state, a second damage state, a third damage state, a fourth damage state and a fifth damage state in sequence from low damage degree to high damage degree; the maintenance resources refer to the counts of single construction teams equipped with corresponding maintenance tools, and the water supply system and the power system are assumed to have corresponding maintenance resources respectively and are not universal; assuming that a damaged component corresponds to a need for a repair resource, repair time increases with the severity of the damage to the component.

Further, in step S2, a chromosome is a sequence, i.e. a numeric string consisting of numbers 1, 2, 3, …, N of the lesion elements, where N is the number of the lesion elements; one chromosome slice corresponds to a hydroelectric system in a corresponding damage state, wherein the damage component is a digital string consisting of serial numbers of components from 1 st to nth of the corresponding chromosome, and N is more than or equal to 1 and less than or equal to N; the identity code of a chromosome slice is a calculated value obtained by taking each serial number in the slice as the index of a number 2 and then summing; the pool of information is a database containing identity codes and hydroelectric function levels of all chromosome slices that have been subjected to functional analysis.

Further, in step S2, the overall hydroelectric function level of a chromosome slice refers to performing functional analysis on the hydroelectric system represented by the chromosome slice, and the steps are as follows:

firstly, performing direct current flow analysis on the power system, and judging whether a water pump in a water supply system can normally operate according to the power supply condition of each power supply service area;

then, hydraulic analysis of the water supply system is performed.

Further, in the step S3, the time step refers to the shortest maintaining time that the overall function level of the hydroelectric system is kept unchanged; the number of components that function normally in a hydroelectric system increases gradually as maintenance work progresses; and if the component repair is completed within a certain time step, performing function analysis again according to the new topological structure of the hydroelectric system to give a new function level, or else, using the function level in the last step for a long time.

Further, in step S3, the overall function level of the hydropower system is that the hydropower system is composed of different service areas, the hydropower supply function level of each service area is obtained through functional analysis, and the overall function level of the hydropower system is obtained according to the weighted average of the number of users in the different service areas, wherein the function level is measured by the percentage that the water demand or the power demand of the users is met, 100% indicates that the water demand or the power demand is completely met, and 0 indicates that no water supply or power supply is provided.

Further, the calculation of the overall functional level of hydropower specifically comprises the following steps:

in the formula (I), the compound is shown in the specification,andthe integral function levels of the water supply system and the power system on the t day are respectively;andthe functional levels of the ith service area of the water supply system on the t day and the jth service area of the power system on the t day are respectively;andweights of the ith service area of the water supply system and the jth service area of the electric power system are respectively set;andthe number of users in the ith service area of the water supply system and the jth service area of the electric power system are respectively.

Further, in step S3, the cumulative time loss of function of the hydro-electric system is calculated by subtracting the sum of the cumulative daily function level in the recovery period from the total number of recovery days, as follows:

in the formula, L^wAnd L^pThe accumulated function loss values of the water supply system and the electric power system are respectively, namely the fitness function of the chromosome; t is^wAnd T^pTotal time for restoration of the water supply system and the electric power system respectively; t is the day during recovery.

The invention has the beneficial effects that:

when the method for the functional restoration decision of the hydropower system which is dependent on each other is optimized, the concept of the chromosome slice is used, and the chromosome slice is subjected to identity coding and identification, so that the process of evaluating the adaptability function which consumes the most time in the genetic algorithm is accelerated, the serious problem that the number of decision variables for restoration optimization is doubled and the program operation time is increased nonlinearly due to the functional dependence among the hydropower systems is relieved to the greatest extent, the restoration decision can meet the time urgency requirement of restoration after disasters, and the method can be really applied to actual disaster scenes.

Drawings

Fig. 1 is a schematic flow chart of a functional restoration decision method of an interdependent hydropower system based on a flexible city according to an embodiment of the invention.

Fig. 2 is a topological diagram of a water supply system in a city according to an embodiment of the present invention.

Fig. 3 is a topological diagram of an electric power system in a certain city according to an embodiment of the present invention.

Fig. 4 is a recovery decision diagram of the water supply system according to the embodiment of the invention.

Fig. 5 is a recovery decision diagram of the power system according to the embodiment of the invention.

Detailed Description

In order to facilitate a better understanding of the invention for those skilled in the art, the invention will be described in further detail with reference to the accompanying drawings and specific examples, which are given by way of illustration only and do not limit the scope of the invention.

As shown in fig. 1, the invention discloses a functional recovery decision method of an interdependent hydroelectric system based on a flexible city, which is described in detail below by taking a certain city as an example.

Step S1, initialization data: the data includes at least topology, components of the water and power systems, initial physical damage conditions of the components of the water and power systems, amount of maintenance resources to maintain the damaged components, and a dependency database to establish the water and power systems.

Specifically, the topology of the water supply system and the power system is a geometric figure composed of nodes and edges, wherein the nodes and the edges are components of the water supply system and the power system; in the water supply system, the node is at least a water pump or a reservoir, and the side is a water supply pipeline; in the power system, the nodes are at least substations or power stations, and the edges are power transmission lines. Wherein, the topological structure data information of the water supply system and the electric power system can be found through government public data or related websites.

The dependency database of the water supply system and the power system refers to a transformer substation or a power station in the power system, which has a corresponding relationship with a water pump in the water supply system, wherein the corresponding relationship refers to that the water pump needs power to maintain normal operation, and if the transformer substation or the power station in the corresponding area is damaged, the power cannot be supplied to the water pump, and the water pump cannot operate.

The initial physical damage conditions of the components of the water supply system and the power system are divided into a first damage state, a second damage state, a third damage state, a fourth damage state and a fifth damage state in sequence from low damage degree to high damage degree, and in the embodiment, the first damage state, the second damage state, the third damage state, the fourth damage state and the fifth damage state are respectively an undamaged state, a slightly damaged state, a medium damaged state, a severely damaged state and a completely damaged state.

The maintenance resources refer to the counts of the single construction team equipped with the corresponding maintenance tool, namely, the maintenance resources of the water supply system refer to the construction team equipped with the maintenance tool for maintaining the water supply system, the maintenance resources of the power system refer to the construction team equipped with the maintenance tool for maintaining the power system, and the water supply system and the power system are assumed to have the corresponding maintenance resources respectively and are not universal.

Assuming that a damaged component corresponds to a need for a repair resource, repair time increases with the severity of the damage to the component.

Fig. 2 and 3 are topological diagrams of a water supply system and an electric power system of the certain city, respectively. The municipal water supply of the city pumps underground water through a water pump, the water supply system has 49 nodes and 98 water pipelines, and the nodes specifically comprise 6 water tanks, 9 water pumps and 34 water utilization nodes; the power system has 59 nodes and 73 power transmission lines, and the nodes specifically comprise 8 source nodes and 51 substations. It is assumed that there are 5 maintenance resources for the water supply system and the power system, respectively.

And S2, randomly generating sequences of a plurality of damage component serial numbers based on the initial physical damage condition of the component obtained in the step S1, setting an identity code of a chromosome slice and an information pool of the integral hydroelectric function level under the corresponding damage state, and setting the iteration times of a genetic algorithm, wherein the sequences are used as chromosomes, namely an initial population.

One chromosome is a sequence, i.e. a numerical string consisting of the numbers 1, 2, 3, …, N of the lesion building blocks, N being the number of lesion building blocks.

A chromosome slice corresponds to a hydroelectric system with a corresponding damage state, wherein the damage component is a numerical string consisting of serial numbers of components from 1 st to nth of the corresponding chromosome, and N is more than or equal to 1 and less than or equal to N.

The identity code of a chromosome section is a calculated value obtained by summing the serial numbers in the section as the index of the number 2.

The pool of information is a database containing identity codes and hydroelectric function levels of all chromosome slices that have been subjected to functional analysis.

The integral hydroelectric function level of a chromosome slice refers to the functional analysis of a hydroelectric system represented by the chromosome slice, and the steps are as follows:

firstly, performing direct current flow analysis on the power system, and judging whether a water pump in a water supply system can normally operate according to the power supply condition of each power supply service area;

then, hydraulic analysis of the water supply system is performed.

Step S3, based on step S2, determining whether the identity code of the chromosome slice to be evaluated already exists in the information pool:

if the water-electricity integral function level exists, the water-electricity integral function level in the information pool is directly called;

otherwise, calculating by using a function analysis method to obtain the integral function level of the hydropower, namely performing direct current power flow analysis on the power system and performing hydraulic analysis calculation on the water supply system; and calculating the identity code of the chromosome slice, storing the identity code and the integral water and electricity function level into an information pool, and acquiring the time accumulated function loss of the water and electricity system according to the time step on the basis of the integral water and electricity function level of the chromosome slice, wherein the time accumulated function loss is the chromosome adaptive function.

In this embodiment, the time step refers to the shortest maintenance time during which the overall functional level of the hydroelectric system is kept unchanged; the number of components that function normally in a hydroelectric system increases gradually as maintenance work progresses; and if the component repair is completed within a certain time step, performing function analysis again according to the new topological structure of the hydroelectric system to give a new function level, or else, using the function level in the last step for a long time.

The overall functional level of the hydropower system is that the hydropower system is composed of different service areas respectively, the hydropower supply functional level of each service area is obtained through functional analysis, and the overall functional level of the hydropower system is obtained according to the weighted average of the number of users in the different service areas, wherein the functional level is measured by the percentage that the water demand or the electricity demand of the users meets, 100% represents that the water demand or the electricity demand of the users meets, and 0 represents that no water supply or power supply exists at all.

The calculation of the overall functional level of the hydropower specifically comprises the following steps:

in the formula (I), the compound is shown in the specification,andthe integral function levels of the water supply system and the power system on the t day are respectively;andthe functional levels of the ith service area of the water supply system on the t day and the jth service area of the power system on the t day are respectively;andweights of the ith service area of the water supply system and the jth service area of the electric power system are respectively set;andthe number of users in the ith service area of the water supply system and the jth service area of the electric power system are respectively.

The cumulative time loss of function of a hydroelectric system is calculated as the sum of the total number of days to restore minus the cumulative daily level of function over the period of restoration, as follows:

in the formula, L^wAnd L^pThe accumulated function loss values of the water supply system and the electric power system are respectively, namely the fitness function of the chromosome; t is^wAnd T^pTotal time for restoration of water supply system and electric power system respectivelyA (c) is added; t is the day during recovery. In this embodiment, the calculated cumulative loss of function of the water supply system is 2.71, and the calculated cumulative loss of function of the electric power system is 6.72. The restoration decisions can be evaluated by calculating the values of the loss of function of the water supply system and the power system.

And S4, based on the step S3, operating the chromosome by using genetic operators such as selection, intersection, mutation and the like at least to obtain the next generation of chromosomes, and if the iteration times are reached, selecting the optimal chromosome based on the adaptive function value.

The optimal recovery decision diagrams of the water supply system and the power system are respectively shown in fig. 4 and 5, the recovery decision diagrams shown in fig. 4 and 5 simultaneously represent the initial damaged component and the required repair time thereof, and the horizontal axis in the embodiment is in days. In repeated tests, the time required for optimization is 30 minutes to 1 hour, and the requirement of time urgency for recovery after disaster can be met, so that the method can be really applied to actual disaster emergency.

The foregoing merely illustrates the principles and preferred embodiments of the invention and many variations and modifications may be made by those skilled in the art in light of the foregoing description, which are within the scope of the invention.