Method and device for improving all-time toughness of power transmission system under ice and snow disasters

Abstract

The invention discloses a power transmission system all-time toughness improvement method and device under ice and snow disasters, and the method comprises the steps: building a power transmission line fault probability model under the ice disasters based on the fault condition of a power transmission line in the ice and snow disasters; defining a toughness evaluation index of the power transmission system under the ice disaster; and on the basis of the toughness evaluation indexes, performing analysis, establishing a full-time toughness improvement scheme, and respectively obtaining optimal toughness improvement strategies before and after disasters. The invention provides an effective toughness improvement framework aiming at ice and snow disasters, based on a series of toughness indexes of system and element levels, including each stage of the ice disaster process, weak links can be found before the ice disaster occurs and preventive measures can be guided, the deicing sequence can be updated in real time in the ice disaster, and the deicing efficiency is improved. Therefore, the influence of disasters on the power transmission system is reduced to the maximum extent, the optimal repair sequence can be obtained after the ice disaster occurs, and the system can recover to the toughness state as soon as possible.

Description

Technical Field

[0001] The present invention relates to the technical field of power transmission systems, and in particular to a method and device for improving the resilience of a power transmission system during an ice and snow disaster. Background Art

[0002] At present, ice disasters and other extreme natural disasters have brought many challenges to the safe and stable operation of power systems. There are many methods for resilience assessment. Most of them take into account the impact of severe weather and climate change on power systems or their components, and then propose corresponding resilience assessment indicators to evaluate the system. However, there is a lack of consideration of component-level indicators and system-level indicators and their coupling relationship.

[0003] Most of the current research methods for improving the resilience of power systems are aimed at natural disasters such as typhoons and earthquakes that occur frequently. However, unlike natural disasters such as typhoons and earthquakes that have a short duration, the erosion of power systems by ice disasters has obvious "multi-stage" and "long-term scale" characteristics. If traditional reinforcement planning methods are used to improve the resilience of power systems, there will be defects such as high investment costs or increased load loss due to the inability to accurately evaluate resilience indicators. Therefore, it is necessary to fully address the impact of ice disasters on power systems in each period before, during, and after the disaster, and propose corresponding resilience improvement measures to build a full-time resilience improvement framework under ice disasters. Summary of the invention

[0004] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0005] In view of the above existing problems, the present invention is proposed. Therefore, the present invention provides a method for improving the resilience of a power transmission system during ice and snow disasters to solve the problem of how to build a framework for improving the resilience of a power transmission system during all periods before, during and after a disaster.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] In a first aspect, the present invention provides a method for improving the resilience of a power transmission system during an ice and snow disaster, including: constructing a failure probability model of a power transmission line during an ice and snow disaster based on the failure conditions of the power transmission line during an ice and snow disaster;

[0008] Based on the fault probability model, a resilience evaluation index of the power transmission system under ice disaster is defined;

[0009] Based on the resilience evaluation indicators and analysis, a full-time resilience improvement plan is established to obtain the optimal resilience improvement strategies before, during and after the disaster.

[0010] As a preferred solution of the method for improving the resilience of the power transmission system during all periods of time under ice and snow disasters described in the present invention, wherein: when constructing the probability model of the power transmission line, the ice load and the wind load are analyzed simultaneously;

[0011] The ice load per transmission line is expressed as:

[0012] L I =9.8×10 -3 ρ 1 π(D+R eq )R eq

[0013] Among them, L 1 represents ice load, D represents conductor diameter, R eq represents ice thickness, ρ 1 represents the density of ice;

[0014] The wind load per transmission line is expressed as:

[0015] L W =CSv 2 (D+2R eq )

[0016] Among them, L W represents wind load, C is a constant, and S is a cross factor;

[0017] The ice load and wind load are subjected to stress analysis to obtain the comprehensive ice and wind load, which is expressed as:

[0018]

[0019] As a preferred solution of the method for improving the resilience of the power transmission system during all periods of time under ice and snow disasters described in the present invention, the fault probability model of the power transmission line under ice disasters is constructed, which includes:

[0020] According to the metal deformation theory and assuming that the transmission line is elliptical, the failure probability model of the transmission line is constructed and expressed as:

[0021]

[0022] Among them, P f represents the failure probability of each unit line, a WI represents the first threshold of ice and wind load, b WI represents the second threshold value of ice and wind load;

[0023] According to the definition of series network, the failure probability of different transmission lines is expressed as:

[0024]

[0025] Among them, L i represents the length of the i-th line, p i represents the failure probability of the i-th transmission line.

[0026] As a preferred solution of the method for improving the resilience of the power transmission system during ice and snow disasters described in the present invention, the establishment of the resilience evaluation index of the power transmission system during ice disasters includes: defining the system-level resilience index R sys , component-level resilience index R before disaster cm,pre and the post-disaster component-level resilience index R cm,post ;

[0027] Among them, the system-level resilience index R is defined sys include:

[0028] The resilience of the system after the ice disaster is expressed as:

[0029]

[0030] Among them, Q 0 represents the elastic performance of the initial system, Q(t) represents the system performance curve under the interruption of transmission lines under ice disaster;

[0031] Combining the system resilience with the transmission line failure probability model, the system-level resilience index R sys , expressed as:

[0032]

[0033] Where E[·] represents the expected value of system resilience, M represents the number of transmission lines, and A represents the set of all transmission lines. represents the k-order subset of A, s represents the transmission line failure scenario caused by ice disaster, P s represents the probability of failure scenario s occurring at a certain moment, I s Represents the load loss in fault scenario s.

[0034] As a preferred solution of the method for improving the resilience of the power transmission system during the whole period under the ice and snow disaster described in the present invention, the component-level resilience index R before the disaster is defined as cm,pre include:

[0035] Define a component-level resilience index to quantify the resilience of each transmission line, and define the component-level resilience index before the disaster based on the increment of the system resilience index caused by the power outage of each transmission line and the probability of failure of each transmission line in a certain ice disaster;

[0036] The component-level resilience index R of the mth transmission line before failure cm,pre It is expressed as:

[0037]

[0038] Among them, p m represents the failure probability of transmission line m, represents the increase in the resilience index of the transmission system caused by the failure of the mth transmission line, s m represents the set of all fault scenarios that include the mth transmission line fault, Indicates the failure scenario m The resulting incremental impact.

[0039] As a preferred solution of the method for improving the resilience of the power transmission system during the whole period under the ice and snow disaster described in the present invention, the component-level resilience index R after the disaster is defined as cm,post include:

[0040] The toughness index after the mth line fault is expressed as:

[0041]

[0042] Where m represents the line number, Ω s represents the set of faulty lines under fault scenario s, Ω m∈s Represents the set Ω s The subset containing the mth transmission line.

[0043] As a preferred solution of the method for improving the full-time resilience of the power transmission system under ice and snow disasters described in the present invention, the full-time resilience improvement solution includes:

[0044] Update forecast weather data and calculate the system resilience index R for the next few days sys ;

[0045] If the system resilience index R sys The value is less than the defined threshold R s , then return to the previous step;

[0046] If the system resilience index R sys The value exceeds the threshold R s , implement the pre-disaster component-level resilience index R cm,pre Indicators of pre-disaster transmission system resilience improvement strategies;

[0047] Check whether the transmission line is frozen. If so, implement R-based cm,pre Transmission system resilience enhancement strategy based on indicators during disasters and R cm,post The post-disaster transmission system resilience enhancement strategy based on the indicator returns to the first step if there is no ice.

[0048] In a second aspect, the present invention provides a device for improving the resilience of a power transmission system during an ice and snow disaster, including: a construction module for constructing a failure probability model of a power transmission line during an ice and snow disaster based on the failure conditions of the power transmission line during an ice and snow disaster;

[0049] An index definition module, used to define resilience evaluation indexes of the power transmission system under ice disasters based on the fault probability model;

[0050] The output module is used to establish a full-time resilience improvement plan based on the resilience evaluation indicators and perform analysis to obtain the optimal resilience improvement strategy before, during and after a disaster.

[0051] In a third aspect, the present invention provides an electronic device, comprising:

[0052] Memory and processor;

[0053] The memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions. When the computer-executable instructions are executed by the processor, the steps of the method for improving the resilience of the power transmission system during all-time periods under ice and snow disasters are implemented.

[0054] In a fourth aspect, the present invention provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, can implement the steps of the method for improving the resilience of a power transmission system during all-time periods under ice and snow disasters.

[0055] Compared with the prior art, the present invention has the following beneficial effects: the present invention proposes an effective resilience enhancement framework for ice and snow disasters, which is based on a series of resilience indicators at the system and component levels, including all stages of the ice disaster process. It can find weak links and guide preventive measures before an ice disaster occurs. During an ice disaster, the de-icing sequence can be updated in real time, thereby minimizing the impact of the disaster on the transmission system. After the ice disaster occurs, the optimal repair sequence can be calculated to restore the system to a resilient state as soon as possible. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0057] Figure 1 It is a schematic diagram of the overall process of a method for improving the resilience of a power transmission system during an ice and snow disaster in all periods according to an embodiment of the present invention;

[0058] Figure 2A schematic diagram of a system-level resilience improvement strategy flow of a method for improving the resilience of a power transmission system during all-time periods under ice and snow disasters according to an embodiment of the present invention;

[0059] Figure 3 A schematic diagram of a pre-disaster resilience improvement strategy flow of a method for improving the resilience of a power transmission system during all-time periods under ice and snow disasters according to an embodiment of the present invention;

[0060] Figure 4 A schematic diagram of a disaster resilience improvement strategy flow of a method for improving the resilience of a power transmission system during a snow disaster in all periods of time according to an embodiment of the present invention;

[0061] Figure 5 A schematic diagram of a post-disaster resilience improvement strategy flow of a method for improving the resilience of a power transmission system during all periods of time under an ice and snow disaster according to an embodiment of the present invention;

[0062] Figure 6 This is a schematic diagram of disaster resilience indicators under different strategies of a method for improving the full-time resilience of a power transmission system under ice and snow disasters described in an embodiment of the present invention. DETAILED DESCRIPTION

[0063] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0064] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0065] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0066] The present invention is described in detail with reference to schematic diagrams. When describing the embodiments of the present invention, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0067] At the same time, in the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "upper, lower, inner and outer" are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first, second or third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0068] In the present invention, unless otherwise clearly specified and limited, the terms "install, connect, connect" should be understood in a broad sense, for example: it can be a fixed connection, a detachable connection or an integral connection; it can also be a mechanical connection, an electrical connection or a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0069] Example 1

[0070] Reference Figure 1-Figure 5 , is an embodiment of the present invention, and provides a method for improving the resilience of a power transmission system during an ice and snow disaster. Figure 1 ,include:

[0071] S101, based on the failure conditions of the transmission lines in ice and snow disasters, a failure probability model of the transmission lines under ice disasters is constructed.

[0072] Preferably, when constructing the probabilistic model of the transmission line, ice load and wind load should be analyzed simultaneously;

[0073] Specifically, the freezing rain ice load model is expressed as:

[0074]

[0075] Among them, R eq Indicates ice thickness, unit: mm, T indicates freezing rain hours, unit: h, r indicates freezing rain rate, unit: mm / h, ρ 1 Indicates ice density, unit: g / cm2, ρ w represents the freezing rain density, unit: g / cm2, v represents the wind speed, unit: m / s, W represents the content of liquid water in the air, W = 0.067 × r 0.864 to conclude;

[0076] The unit transmission line ice load is expressed as:

[0077] L I =9.8×10 -3 ρ 1 π(D+R eq )R eq

[0078] Among them, L 1 represents ice load, unit: N / m, D represents conductor diameter, unit: mm;

[0079] The wind load per transmission line is expressed as:

[0080] L W =CSv 2 (D+2R eq )

[0081] Among them, L W It represents wind load, unit: N / m, C is a constant, which is 6.964×10 -3 , S is the crossover factor;

[0082] The force analysis of ice load and wind load is carried out to obtain the comprehensive ice-wind load, which is expressed as:

[0083]

[0084] It should be noted that power systems are usually reliability-oriented, so most existing indicators are only applicable to situations where component availability is fixed. However, when power systems face some extreme but relatively rare disasters, such as ice disasters, the failure probability of transmission lines tends to vary with the severity of the disaster. The failure of transmission lines in ice and snow disasters is mainly due to the vertical force caused by ice and the horizontal force caused by wind. Therefore, when establishing a probabilistic model for transmission lines, both ice load and wind load should be considered.

[0085] Preferably, constructing a failure probability model of a power transmission line under an ice disaster includes:

[0086] The transmission line can withstand a certain force threshold. When the force exceeds the threshold, the transmission line will be disconnected. According to the metal deformation theory and assuming that the transmission line is elliptical, a transmission line failure probability model is constructed, which is expressed as:

[0087]

[0088] Among them, P f represents the failure probability of each unit line, a WI represents the first threshold of ice and wind load, b WI represents the second threshold value of ice and wind load;

[0089] According to the definition of series network, the failure probability of different transmission lines is expressed as:

[0090]

[0091] Among them, L i represents the length of the i-th line, pi represents the failure probability of the i-th transmission line.

[0092] S102: Based on the failure probability model, define the resilience evaluation index of the power transmission system under ice disasters.

[0093] Preferably, establishing the resilience evaluation index of the power transmission system under ice disasters includes: defining the system-level resilience index R sys , component-level resilience index R before disaster cm,pre and the post-disaster component-level resilience index R cm,post ;

[0094] Among them, the system-level resilience index R is defined sys include:

[0095] Experience shows that transmission lines may fail at any time during an ice disaster, causing great inconvenience to the system. After an ice disaster occurs, the resilience of the system is expressed as:

[0096]

[0097] Among them, Q 0 represents the elastic performance of the initial system, Q(t) represents the system performance curve under the interruption of transmission lines under ice disaster;

[0098] Taking into account the uncertainty of ice disasters, the system resilience index is expressed as the expected impact of potential failure scenarios that may occur under specific disasters. Combining the system resilience with the transmission line failure probability model, the system-level resilience index R sys , expressed as:

[0099]

[0100] Where E[·] represents the expected value of system resilience, M represents the number of transmission lines, and A represents the set of all transmission lines. represents the k-order subset of A, s represents the transmission line failure scenario caused by ice disaster, P s represents the probability of failure scenario s occurring at a certain moment, I s represents the load loss in fault scenario s;

[0101] When facing extreme ice disasters, it is easy for multiple transmission lines to fail at the same time, resulting in high-order failure scenarios. In order to reduce the errors caused by ignoring high-order scenarios and maintain the rapidity of calculation, the influence increment-based state enumeration method (IISE) is introduced in the calculation process of system resilience assessment. The system-level resilience index is expressed as:

[0102]

[0103] Where ΔIs represents the load loss increment caused by fault scenario s.

[0104] Preferably, define the pre-disaster component-level resilience index R cm,pre include:

[0105] Define component-level resilience index to quantify the resilience of each transmission line. Define component-level resilience index before the disaster based on the increment of system resilience index caused by power outage of each transmission line and the probability of failure of each transmission line in a certain ice disaster.

[0106] The component-level resilience index R of the mth transmission line before failure cm,pre It is expressed as:

[0107]

[0108] Among them, p m represents the failure probability of transmission line m, represents the increase in the resilience index of the transmission system caused by the failure of the mth transmission line, s m represents the set of all fault scenarios that include the mth transmission line fault, Indicates the failure scenario m The resulting incremental impact.

[0109] Specifically, the increment of the system resilience index caused by the mth transmission failure is expressed as:

[0110]

[0111]

[0112] in, represents the system resilience index before the mth transmission line fails, that is, its failure probability is 0, represents the system resilience index after the mth transmission line fails, that is, its failure probability is 1, s m represents the set of all fault scenarios that include the mth transmission line fault, and s 0 represents the set of all fault scenarios that do not include the mth transmission line fault, For failure scenarios m The resulting incremental impact, For failure scenarios 0 The resulting incremental impact.

[0113] It should be noted that according to the transmission line failure probability model, the failure probability of different transmission lines is different. Therefore, the contribution of different components to system resilience is also different. Generally speaking, during an ice disaster, the greater the probability of a transmission line failure, or the greater the load reduction caused by the transmission line, the more critical the transmission line is. In summary, when defining the component-level resilience index to quantify the resilience of each transmission line, two aspects should be considered: the incremental system resilience index caused by the power outage of each transmission line; and the probability of failure of each transmission line in a certain ice disaster.

[0114] Preferably, define the component-level resilience index R after the disaster cm,post include:

[0115] The toughness index after the mth line fault is expressed as:

[0116]

[0117] Where m represents the line number, Ω s represents the set of faulty lines under fault scenario s, Ω m∈s Represents the set Ω s The subset containing the mth transmission line.

[0118] It should be noted that although preventive measures can be taken to avoid the loss of resilience of the transmission system, considering the unpredictability of ice disasters, it is still inevitable that the transmission system will suffer a certain degree of loss. In this case, it is necessary to evaluate each faulty line so that remedial measures can be taken in time to restore the resilience of the system as soon as possible. Therefore, a post-disaster component-level resilience index is proposed to provide theoretical guidance for the line repair sequence.

[0119] S103, based on the resilience evaluation indicators and analysis, establish a full-time resilience improvement plan to obtain the optimal resilience improvement strategy before, during and after the disaster.

[0120] Preferably, Figure 2 , establish a full-time resilience improvement plan including:

[0121] Update forecast weather data and calculate the system resilience index R for the next few days sys ;

[0122] If the system resilience index R sys The value is less than the defined threshold R s , then return to the previous step, where the threshold R s Set according to the actual application scenario;

[0123] If the system resilience index R sys The value exceeds the threshold R s , implement the pre-disaster component-level resilience index R cm,preThe pre-failure resilience enhancement strategy of the indicators, i.e. the strategy to enhance the resilience of the transmission system before a disaster;

[0124] Check whether the transmission line is frozen. If so, implement R-based cm,pre Transmission system resilience improvement strategy based on indicators in disasters and R cm,post The indicator's post-disaster transmission system resilience improvement strategy returns to the first step if there is no ice.

[0125] It should be noted that before a fault occurs, this solution can be applied to locate the weak links of the system and take appropriate protection measures for the most critical lines. When a disaster occurs, emergency de-icing work can be guided by daily updated priority rankings. After the ice disaster is over, selective and targeted maintenance work can be carried out to achieve optimal maintenance efficiency.

[0126] Specifically, the steps of resilience enhancement strategies in each period are as follows:

[0127] Option 1, the strategy for improving the resilience of the power transmission system before the ice disaster is as follows:

[0128] In order to minimize potential losses, effective preventive measures need to be taken on key lines before the disaster. This is the core of the resilience improvement strategy during this period. The specific steps of the resilience improvement strategy are as follows: Figure 3 As shown, step one, update the weather forecast data; step two, calculate the pre-disaster component-level resilience index of each transmission line in the future period; step three, sort these indicators and determine the prevention priority of each transmission line; step four, take preventive measures for key lines according to the priority order, such as applying antifreeze materials to the transmission lines in advance to reduce the possibility of icing; step five, after all these measures are completed, identify whether there is ice on the transmission lines. If not, return to step one, otherwise, the pre-disaster period ends and the next stage begins.

[0129] Option 2, strategies for improving the resilience of the power transmission system during ice disasters are as follows:

[0130] Specific steps for improving resilience include: Figure 4 As shown in the figure, step 1 is to update the actual situation and forecast the weather for the next day; step 2 is to calculate the pre-disaster component-level resilience index of each transmission line on the next day based on plan 1; step 3 is to update the key priorities of the transmission lines based on these indicators; step 4 is to arrange relevant personnel to implement de-icing measures according to the important priorities. After all these measures are completed, confirm that all faults have been resolved. If not, return to plan 1. Otherwise, the mid-disaster period ends and the next stage begins.

[0131] Option 3, strategies for improving the resilience of power transmission systems after ice disasters are as follows:

[0132] Specific steps for improving resilience include: Figure 5 As shown, step one is to update the faulty transmission lines identified in the system, and then calculate the resilience index of each transmission line after the fault; step two is to sort these indexes and determine the maintenance priority of each transmission line; step three is to take emergency maintenance measures in order of priority, and after each round of maintenance, check whether there is a transmission line fault. If so, return to plan one, otherwise end.

[0133] The present invention proposes an effective resilience enhancement framework for ice and snow disasters. It is based on a series of resilience indicators at the system and component levels, including all stages of the ice disaster process. It can find weak links and guide preventive measures before an ice disaster occurs. During an ice disaster, the de-icing sequence can be updated in real time to minimize the impact of the disaster on the transmission system. After the ice disaster occurs, the optimal repair sequence can be calculated to restore the system to a resilient state as soon as possible.

[0134] The above is a schematic scheme of a method for improving the full-time resilience of a power transmission system under ice and snow disasters in this embodiment. It should be noted that the technical scheme of the device for improving the full-time resilience of a power transmission system under ice and snow disasters and the technical scheme of the method for improving the full-time resilience of a power transmission system under ice and snow disasters described above belong to the same concept. For details not described in detail in the technical scheme of the device for improving the full-time resilience of a power transmission system under ice and snow disasters in this embodiment, please refer to the description of the technical scheme of the method for improving the full-time resilience of a power transmission system under ice and snow disasters described above.

[0135] In this embodiment, the device for improving the resilience of the power transmission system during ice and snow disasters at all times includes:

[0136] A construction module is used to construct a failure probability model of transmission lines under ice and snow disasters based on the failure conditions of transmission lines in ice and snow disasters;

[0137] The indicator definition module is used to define the resilience evaluation indicators of the power transmission system under ice disasters based on the fault probability model;

[0138] The output module is used to establish a full-time resilience improvement plan based on resilience evaluation indicators and conduct analysis, and to obtain the optimal resilience improvement strategy before, during, and after a disaster.

[0139] This embodiment also provides an electronic device, which is suitable for improving the resilience of the power transmission system during all-time periods under ice and snow disasters, including:

[0140] Memory and processor; the memory is used to store computer-executable instructions, and the processor is used to execute computer-executable instructions to implement the method for improving the resilience of the power transmission system during ice and snow disasters at all times as proposed in the above-mentioned embodiment.

[0141] This embodiment also provides a storage medium on which a computer program is stored. When the program is executed by a processor, the method for improving the resilience of the power transmission system during ice and snow disasters at all times as proposed in the above embodiment is implemented.

[0142] The storage medium proposed in this embodiment and the method for improving the resilience of the power transmission system during ice and snow disasters proposed in the above embodiment belong to the same inventive concept. The technical details not described in detail in this embodiment can be found in the above embodiment, and this embodiment has the same beneficial effects as the above embodiment.

[0143] Through the above description of the implementation methods, the technicians in the relevant field can clearly understand that the present invention can be implemented by means of software and necessary general hardware, and of course can also be implemented by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as a computer floppy disk, read-only memory (ReadOnly, Memory, ROM), random access memory (RandomAccess Memory, RAM), flash memory (FLASH), hard disk or optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform the methods of various embodiments of the present invention.

[0144] Example 2

[0145] Reference Figure 6 , which is an embodiment of the present invention, provides a method for improving the resilience of a power transmission system during all periods of time under ice and snow disasters. In order to verify its beneficial effects, comparison results of multiple schemes are provided.

[0146] The IEEE RTS-79 test system was used for verification and analysis. Taking the disaster period as an example, the advantages of the method proposed in the present invention were demonstrated by comparison with other disaster resilience improvement strategies.

[0147] Improvement strategy A: De-icing measures start from the first day and decrease according to the length of the transmission line.

[0148] Improvement strategy B: De-icing measures are implemented from the first day, and the de-icing order is based on the priority order that is updated in real time every day.

[0149] Improvement strategy C: De-icing measures start from the time the system loses load, and the de-icing sequence is updated daily based on the pre-disaster component-level resilience indicators.

[0150] Improvement strategy D: De-icing measures start from the first day, and the de-icing sequence is updated every day according to the pre-disaster component-level resilience indicators.

[0151] Strategy D strictly follows the disaster resilience improvement strategy proposed by the present invention and takes deicing measures. A more direct comparison of these four strategies is as follows: Figure 6 As shown, Strategy A demonstrates the importance of de-icing with priority, Strategy B illustrates the importance of de-icing according to a priority order updated in real time, and Strategy C illustrates the importance of taking de-icing measures when ice first forms. Importantly, all demonstrate the advantages of Strategy D.

[0152] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for improving the resilience of a power transmission system during all periods of time under ice and snow disasters, characterized in that: include: Based on the failure conditions of power transmission lines in ice and snow disasters, a failure probability model of power transmission lines under ice disasters is constructed; Based on the fault probability model, a resilience evaluation index of the power transmission system under ice disaster is defined; Based on the resilience evaluation indicators and analysis, a full-time resilience improvement plan is established to obtain the optimal resilience improvement strategies before, during and after the disaster.

2. The method for improving the resilience of the power transmission system during ice and snow disasters as claimed in claim 1, characterized in that: When constructing a probabilistic model of a transmission line, analyze both ice loads and wind loads; The ice load per transmission line is expressed as: L I =9.8×10 -3 ρ1π(D+R eq )R eq Where L1 represents the ice load, D represents the conductor diameter, and R eq represents ice thickness, ρ1 represents ice density; The wind load per transmission line is expressed as: L W =CSv 2 (D+2R eq ) Among them, L W represents wind load, C is a constant, and S is a cross factor; The ice load and wind load are subjected to stress analysis to obtain the comprehensive ice and wind load, which is expressed as:

3. The method for improving the resilience of the power transmission system during ice and snow disasters as claimed in claim 2, characterized in that: The failure probability model of transmission lines under ice disasters includes: According to the metal deformation theory and assuming that the transmission line is elliptical, the failure probability model of the transmission line is constructed and expressed as: Among them, P f represents the failure probability of each unit line, a WI represents the first threshold of ice and wind load, b WI represents the second threshold value of ice and wind load; According to the definition of series network, the failure probability of different transmission lines is expressed as: Among them, L i represents the length of the i-th line, p i represents the failure probability of the i-th transmission line.

4. The method for improving the resilience of the power transmission system during ice and snow disasters in all periods of time according to claim 1 or 3, characterized in that: Establishing resilience evaluation indicators for power transmission systems under ice disasters includes: defining system-level resilience index R sys , component-level resilience index R before disaster cm,pre and the post-disaster component-level resilience index R cm,post ; Among them, the system-level resilience index R is defined sys include: The resilience of the system after the ice disaster is expressed as: Among them, Q0 represents the elastic performance of the initial system, Q(t) represents the system performance curve under the interruption of transmission line under ice disaster; Combining the system resilience with the transmission line failure probability model, the system-level resilience index R sys , expressed as: Where E[·] represents the expected value of system resilience, M represents the number of transmission lines, and A represents the set of all transmission lines. represents the k-order subset of A, s represents the transmission line failure scenario caused by ice disaster, P s represents the probability of failure scenario s occurring at a certain moment, I s Represents the load loss in fault scenario s.

5. The method for improving the resilience of the power transmission system during ice and snow disasters as claimed in claim 4, characterized in that: Define the component-level resilience index R before the disaster cm,pre include: Define a component-level resilience index to quantify the resilience of each transmission line, and define the component-level resilience index before the disaster based on the increment of the system resilience index caused by the power outage of each transmission line and the probability of failure of each transmission line in a certain ice disaster; The component-level resilience index R of the mth transmission line before failure cm,pre It is expressed as: Among them, p m represents the failure probability of transmission line m, represents the increase in the resilience index of the transmission system caused by the failure of the mth transmission line, s m represents the set of all fault scenarios that include the mth transmission line fault, Indicates the failure scenario m The resulting incremental impact.

6. The method for improving the resilience of the power transmission system during ice and snow disasters as claimed in claim 5, characterized in that: Define the component-level resilience index R after the disaster cm,post include: The toughness index after the mth line fault is expressed as: Where m represents the line number, Ω s represents the set of faulty lines under fault scenario s, Ω m∈s Represents the set Ω s contains the subset of the mth transmission line.

7. The method for improving the resilience of the power transmission system during ice and snow disasters as claimed in claim 6, characterized in that: The full-time resilience enhancement plan includes: Update forecast weather data and calculate the system resilience index R for the next few days sys ; If the system resilience index R sys The value is less than the defined threshold R s , then return to the previous step; If the system resilience index R sys The value exceeds the threshold R s , implement the pre-disaster component-level resilience index R cm,pre Indicators of pre-disaster transmission system resilience improvement strategies; Check whether the transmission line is frozen. If so, implement R-based cm,pre Transmission system resilience enhancement strategy based on indicators during disasters and R cm,post The indicator's post-disaster transmission system resilience enhancement strategy returns to the first step if there is no ice.

8. A device for improving the resilience of power transmission systems during ice and snow disasters, characterized in that: include, A construction module is used to construct a failure probability model of transmission lines under ice and snow disasters based on the failure conditions of transmission lines in ice and snow disasters; An index definition module, used to define resilience evaluation indexes of the power transmission system under ice disasters based on the fault probability model; The output module is used to establish a full-time resilience improvement plan based on the resilience evaluation indicators and perform analysis to obtain the optimal resilience improvement strategy before, during and after a disaster.

9. An electronic device, characterized in that: include: Memory and processor; The memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions. When the computer-executable instructions are executed by the processor, the steps of the method for improving the full-time resilience of the power transmission system under ice and snow disasters as described in any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium, characterized in that: It stores computer executable instructions, which, when executed by a processor, implement the steps of the method for improving the full-time resilience of a power transmission system under ice and snow disasters as described in any one of claims 1 to 7.

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