Low-voltage distribution network state evaluation method, system, equipment and medium

Abstract

The invention relates to the technical field of low-voltage distribution network detection, in particular to a low-voltage distribution network state evaluation method, system and device and a medium. Firstly, electric power data are collected from a low-voltage distribution network and preprocessed; secondly, constructing a state evaluation index according to the preprocessed power data, and performing normalization processing; then, according to the normalized state evaluation index, a subjective and objective combined method is adopted to calculate a supervisor weight and an objective evaluation weight of the state evaluation index, and a comprehensive evaluation weight is obtained; and finally, according to the comprehensive evaluation weight, establishing an evaluation function to calculate an evaluation value, and obtaining a low-voltage distribution network state evaluation result. The evaluation cost is reduced while the evaluation efficiency is improved, and the evaluation credibility is further improved by adopting a subjective and objective combination mode.

Description

Technical Field

[0001] The present invention relates to the technical field of low-voltage distribution network intelligent detection, and in particular to a low-voltage distribution network state assessment method, system, equipment and medium. Background Art

[0002] With the improvement of residential power grids, distribution transformers are used to connect various low-voltage distribution networks at the grid terminals. Distribution transformers have become key equipment for power grid supply. When managing power supply, it is necessary to follow up the operating status of distribution transformers in real time, promptly discover abnormal distribution transformers, and then handle abnormal distribution transformers to ensure the stability of power supply in the grid. In the prior art, the voltage, current and other equipment operating information of distribution transformers and the temperature rise, oil level and other transformer body environmental information of distribution transformers are usually evaluated. However, due to the large number and types of distribution transformers in the distribution network, the long service life of distribution transformers, and the different types and accuracy of the equipment of the collection equipment, the collected data is huge and complicated, making it difficult to unify the evaluation standards, which is easy to cause hidden dangers in the low-voltage distribution network, and the evaluation effect is not ideal. Summary of the invention

[0003] Aiming at the problems that the existing evaluation methods make it difficult to unify the evaluation standards, easily cause the hidden dangers of low-voltage distribution network, and the evaluation effect is not ideal, the present invention proposes a low-voltage distribution network status evaluation method, system, equipment and medium; firstly, power data is collected from the low-voltage distribution network and preprocessed; secondly, a status evaluation index is constructed according to the preprocessed power data, and normalized; then, according to the normalized status evaluation index, a subjective and objective combination method is adopted to calculate the principal weight and objective evaluation weight of the status evaluation index to obtain a comprehensive evaluation weight; finally, an evaluation function is established according to the comprehensive evaluation weight to calculate the evaluation value, and the low-voltage distribution network status evaluation result is obtained; while improving the evaluation efficiency, the evaluation cost is reduced, and the evaluation credibility is further improved by adopting a subjective and objective combination method.

[0004] The specific implementation contents of the present invention are as follows:

[0005] A method for evaluating the state of a low-voltage distribution network comprises the following steps:

[0006] Step S1: Collecting power data from the low voltage distribution network and preprocessing;

[0007] Step S2: constructing a state evaluation index based on the preprocessed power data and normalizing it;

[0008] Step S3: According to the normalized state evaluation index, the subjective weight and objective evaluation weight of the state evaluation index are calculated by combining subjective and objective methods to obtain the comprehensive evaluation weight;

[0009] Step S4: Establish an evaluation function according to the comprehensive evaluation weight to calculate the evaluation value and obtain the low-voltage distribution network status evaluation result.

[0010] In order to better implement the present invention, further, the step S2 specifically includes the following steps:

[0011] Step S21: Calculate the average value from the geometric center of the power supply range of the low-voltage distribution network area to the power supply boundary of the low-voltage distribution network area according to the low-voltage distribution network area positioning system data obtained from the pre-processed power data, and use it as the first state evaluation indicator;

[0012] Step S22: Calculate the comprehensive line loss rate of the low-voltage distribution network based on the power supply amount and the power sales amount of the low-voltage distribution network area obtained from the pre-processed power data, and use it as the second state evaluation indicator;

[0013] Step S23: Calculate the transformer load rate according to the actual active power of the low-voltage distribution network transformer and the rated active power of the low-voltage distribution network transformer obtained from the pre-processed power data, and use it as the third state evaluation indicator;

[0014] Step S24: Calculate the voltage qualification rate according to the voltage over-limit time and power supply time obtained from the pre-processed power data, and use it as the fourth state evaluation indicator;

[0015] Step S25: Calculate the three-phase load imbalance according to the A-phase load, B-phase load, and C-phase load obtained from the pre-processed power data, and use it as the fifth state evaluation indicator;

[0016] Step S26: Calculate the perception data qualification rate based on the power perception data and power abnormality data obtained from the pre-processed power data, and use it as the sixth state evaluation indicator.

[0017] In order to better implement the present invention, further, the step S3 specifically includes the following steps:

[0018] Step S31: according to the normalized state evaluation index, the order relationship analysis method is called to calculate the subjective evaluation weight of the state evaluation index;

[0019] Step S32: according to the normalized state evaluation index, the coefficient of variation method is called to calculate the objective evaluation weight of the state evaluation index;

[0020] Step S33: Based on the subjective evaluation weight and the objective evaluation weight, the Lagrange optimal multiplier method is called to calculate the comprehensive evaluation weight.

[0021] In order to better implement the present invention, further, step S31 specifically includes the following steps:

[0022] Step S311: sorting the state evaluation indicators according to the importance of the normalized state evaluation indicators and combining the acquired subjective will of the experts to obtain the state evaluation indicators after subjective sorting;

[0023] Step S312: subjectively assigning relative importance of adjacent state evaluation indicators according to the subjectively sorted state evaluation indicators to obtain an importance ratio;

[0024] Step S313: Calculate the subjective evaluation weight according to the importance ratio.

[0025] In order to better implement the present invention, further, the specific operation of step S32 is: according to the standard deviation of the state evaluation indicator and the mean value of the state evaluation indicator, the coefficient of variation of the state evaluation indicator is calculated, and then the objective evaluation weight is calculated according to the coefficient of variation.

[0026] In order to better implement the present invention, further, the specific operation of step S4 is: constructing an evaluation function vector according to the comprehensive evaluation weight, obtaining a state evaluation function calculation evaluation value, and obtaining a low-voltage distribution network state evaluation result according to the evaluation.

[0027] In order to better realize the present invention, further, the low-voltage distribution network status evaluation result obtained according to the evaluation specifically includes: if the evaluation value is greater than 0 and less than 0.25, the low-voltage distribution network status is evaluated as excellent; if the evaluation value is greater than 0.25 and less than 0.5, the low-voltage distribution network status is evaluated as good; if the evaluation value is greater than 0.5 and less than 0.75, the low-voltage distribution network status is evaluated as passing; if the evaluation value is greater than 0.75 and less than 1, the low-voltage distribution network status is evaluated as failing.

[0028] Based on the low-voltage distribution network status assessment method proposed above, in order to better realize the present invention, further, a low-voltage distribution network status assessment system is proposed, which is used to execute the low-voltage distribution network status assessment method proposed above, including a collection unit, an indicator construction unit, a weight calculation unit, and an assessment unit;

[0029] The collection unit is used to collect power data from the low-voltage distribution network and pre-process it;

[0030] The indicator construction unit is used to construct a state evaluation indicator according to the preprocessed power data and perform normalization processing;

[0031] The weight calculation unit is used to calculate the subjective weight and objective evaluation weight of the state evaluation index according to the normalized state evaluation index by adopting a subjective and objective method to obtain a comprehensive evaluation weight;

[0032] The evaluation unit is used to establish an evaluation function according to the comprehensive evaluation weight to calculate the evaluation value and obtain the low-voltage distribution network status evaluation result.

[0033] Based on the above-proposed low-voltage distribution network status assessment method, in order to better implement the present invention, further, an electronic device is proposed, including a memory and a processor; a computer program is stored on the memory; when the computer program is executed on the processor, the above-proposed low-voltage distribution network status assessment method is implemented.

[0034] Based on the low-voltage distribution network status assessment method proposed above, in order to better realize the present invention, further, a computer-readable storage medium is proposed, on which computer instructions are stored; when the computer instructions are executed on the above-mentioned electronic device, the above-mentioned low-voltage distribution network status assessment method is implemented.

[0035] The present invention has the following beneficial effects:

[0036] (1) The present invention establishes an evaluation function to calculate an evaluation value based on a comprehensive evaluation weight, thereby obtaining an evaluation result of the low-voltage distribution network status; thereby improving evaluation efficiency and reducing evaluation costs.

[0037] (2) The present invention combines ordinal relationship analysis with the coefficient of variation method to make the weight of each indicator more reasonable and objective, which not only reflects the experience of experts but also takes into account the information of the indicator itself. The combination of subjective and objective methods further improves the credibility of the evaluation. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 A schematic flowchart of the low-voltage distribution network status assessment method provided by the present invention. DETAILED DESCRIPTION

[0039] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. It should be understood that the described embodiments are only part of the embodiments of the present invention, not all of the embodiments, and therefore should not be regarded as limiting the scope of protection. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technical personnel in this field without making creative work are within the scope of protection of the present invention.

[0040] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "disposed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0041] Embodiment 1:

[0042] This embodiment provides a method for evaluating the status of a low-voltage distribution network, which specifically includes the following steps:

[0043] Step S1: Collecting power data from the low voltage distribution network and preprocessing;

[0044] Step S2: constructing a state evaluation index based on the preprocessed power data and normalizing it;

[0045] The step S2 specifically includes the following steps:

[0046] Step S21: Calculate the average value from the geometric center of the power supply range of the low-voltage distribution network area to the power supply boundary of the low-voltage distribution network area according to the low-voltage distribution network area positioning system data obtained from the pre-processed power data, and use it as the first state evaluation indicator;

[0047] Step S22: Calculate the comprehensive line loss rate of the low-voltage distribution network based on the power supply amount and the power sales amount of the low-voltage distribution network area obtained from the pre-processed power data, and use it as the second state evaluation indicator;

[0048] Step S23: Calculate the transformer load rate according to the actual active power of the low-voltage distribution network transformer and the rated active power of the low-voltage distribution network transformer obtained from the pre-processed power data, and use it as the third state evaluation indicator;

[0049] Step S24: Calculate the voltage qualification rate according to the voltage over-limit time and power supply time obtained from the pre-processed power data, and use it as the fourth state evaluation indicator;

[0050] Step S25: Calculate the three-phase load imbalance according to the A-phase load, B-phase load, and C-phase load obtained from the pre-processed power data, and use it as the fifth state evaluation indicator;

[0051] Step S26: Calculate the perception data qualification rate based on the power perception data and power abnormality data obtained from the pre-processed power data, and use it as the sixth state evaluation indicator.

[0052] Step S3: According to the normalized state evaluation index, the subjective weight and objective evaluation weight of the state evaluation index are calculated by combining subjective and objective methods to obtain the comprehensive evaluation weight;

[0053] The step S3 specifically comprises the following steps:

[0054] Step S31: according to the normalized state evaluation index, the order relationship analysis method is called to calculate the subjective evaluation weight of the state evaluation index;

[0055] Step S31 specifically includes the following steps:

[0056] Step S311: sorting the state evaluation indicators according to the importance of the normalized state evaluation indicators and combining the acquired subjective will of the experts to obtain the state evaluation indicators after subjective sorting;

[0057] Step S312: subjectively assigning relative importance of adjacent state evaluation indicators according to the subjectively sorted state evaluation indicators to obtain an importance ratio;

[0058] Step S313: Calculate the subjective evaluation weight according to the importance ratio.

[0059] Step S32: according to the normalized state evaluation index, the coefficient of variation method is called to calculate the objective evaluation weight of the state evaluation index;

[0060] The specific operation of step S32 is: calculating the coefficient of variation of the state evaluation index according to the standard deviation of the state evaluation index and the mean of the state evaluation index, and then calculating the objective evaluation weight according to the coefficient of variation.

[0061] Step S33: Based on the subjective evaluation weight and the objective evaluation weight, the Lagrange optimal multiplier method is called to calculate the comprehensive evaluation weight.

[0062] Step S4: Establish an evaluation function according to the comprehensive evaluation weight to calculate the evaluation value and obtain the low-voltage distribution network status evaluation result.

[0063] The specific operation of step S4 is: constructing an evaluation function vector according to the comprehensive evaluation weight, obtaining a state evaluation function calculation evaluation value, and obtaining a low-voltage distribution network state evaluation result according to the evaluation.

[0064] The low-voltage distribution network status assessment result obtained according to the assessment specifically includes: if the assessment value is greater than 0 and less than 0.25, the low-voltage distribution network status is assessed as excellent; if the assessment value is greater than 0.25 and less than 0.5, the low-voltage distribution network status is assessed as good; if the assessment value is greater than 0.5 and less than 0.75, the low-voltage distribution network status is assessed as passing.

[0065] Working principle: This embodiment first collects power data from the low-voltage distribution network and pre-processes it; secondly, it constructs a state evaluation index based on the pre-processed power data and normalizes it; then, based on the normalized state evaluation index, a subjective and objective combination of methods is used to calculate the principal weight and objective evaluation weight of the state evaluation index to obtain a comprehensive evaluation weight; finally, an evaluation function is established based on the comprehensive evaluation weight to calculate the evaluation value and obtain the low-voltage distribution network state evaluation result; while improving the evaluation efficiency, it reduces the evaluation cost, and further improves the evaluation credibility by combining subjective and objective methods.

[0066] Embodiment 2:

[0067] This embodiment is based on the above embodiment 1. Figure 1 As shown, a specific embodiment is described in detail.

[0068] Step S1: Collecting power data from the low voltage distribution network and preprocessing;

[0069] Step S2: constructing a state evaluation index based on the preprocessed power data and normalizing it;

[0070] The step S2 specifically includes the following steps:

[0071] Step S21: Based on the low-voltage distribution network substation positioning system data obtained from the pre-processed power data, calculate the average value from the geometric center of the low-voltage distribution network substation power supply range to the low-voltage distribution network power supply boundary, and obtain the power supply radius as the first state evaluation index G1; the first state evaluation index G1 is the basis for evaluating the state of the low-voltage distribution network.

[0072] Step S22: Calculate the comprehensive line loss rate of the low-voltage distribution network based on the power supply and power sales of the low-voltage distribution network obtained from the pre-processed power data, and use it as the second state evaluation indicator G2; the second state evaluation indicator G2 is a representation of the economic state of the low-voltage distribution network.

[0073] G2=(W1-W2) / W1

[0074] Among them, W1 is the power supply of the low-voltage distribution network area, and W2 is the power sales of the low-voltage distribution network area.

[0075] Step S23: Calculate the transformer load rate according to the actual active power of the low-voltage distribution network transformer and the rated active power of the low-voltage distribution network transformer obtained from the pre-processed power data, and use it as the third state evaluation index G3; The third state evaluation index G3; When the operation of the transformer is in the economic curve interval, the smaller the load rate, the better the health state. When the operation of the transformer is at the upper and lower limits of the economic curve, it means that the transformer load is too heavy or the transformer capacity is too large, and the corresponding load rate is too large or too small, which affects the absorption of new energy and reduces the stability of the distribution network.

[0076] G3=P2 / P1

[0077] Among them, P1 is the actual active power of the transformer in the low-voltage distribution network area, and P2 is the rated active power of the transformer in the low-voltage distribution network area.

[0078] Step S24: Calculate the voltage qualification rate based on the voltage over-limit time and power supply time obtained from the pre-processed power data, and use it as the fourth state evaluation indicator G4; a low voltage qualification rate will cause users to frequently encounter difficulties in starting electrical equipment, etc., so the issue of voltage qualification rate compliance is the key to current power quality management.

[0079] G4=1-T2 / T1

[0080] Among them, T1 is the voltage over-limit time, and T2 is the power supply time.

[0081] Step S25: Calculate the three-phase load imbalance based on the A-phase load, B-phase load, and C-phase load obtained from the pre-processed power data, and use it as the fifth state evaluation indicator G5; the three-phase load usually has a certain deviation. When the access power of the charging pile is too large or unevenly distributed, it will cause three-phase voltage imbalance. Therefore, the smaller the three-phase load imbalance, the better the low-voltage distribution network state.

[0082] G5=(3max{Q A , Q B , Q C}-(Q A +Q B +Q C )) / (Q A +Q B +Q C )

[0083] Among them, Q A is the A phase load, Q B is the B phase load, Q C It is the C phase load.

[0084] Step S26: Calculate the qualified rate of the perception data based on the power perception data and power abnormal data obtained from the pre-processed power data, and use it as the sixth state evaluation index G6. The power perception data collected from the low-voltage distribution network usually contains abnormal data, which causes certain errors in the overall situation perception of the low-voltage distribution network. When the data quality is poor, the equipment needs to be transformed and upgraded. Therefore, the higher the qualified rate of the perception data, the better the state of the low-voltage distribution network, and the more credible the evaluation result.

[0085] G6=1-n2 / n1

[0086] Among them, n2 is the number of outliers in the power anomaly data that exceeds three times the standard deviation range; n1 is the total number of power sensing data.

[0087] Step S3: normalize the index to the interval [0, 1], and calculate the subjective weight and objective evaluation weight of the state evaluation index by combining subjective and objective methods according to the normalized state evaluation index to obtain the comprehensive evaluation weight;

[0088] The step S3 specifically comprises the following steps:

[0089] Step S31: Based on the normalized state assessment index, the ordinal relationship analysis method is called to calculate the subjective assessment weight of the state assessment index; the ordinal relationship method is improved based on the hierarchical analysis method, which overcomes the shortcomings of the hierarchical analysis method, that is, the single fixed decision result and the large amount of weight calculation. It does not need to calculate the judgment matrix and consistency analysis, and can simulate expert experience, so it can meet the needs of subjective weight calculation of low-voltage distribution network state assessment indicators.

[0090] Step S31 specifically includes the following steps:

[0091] Step S311: sorting the state evaluation indicators according to the importance of the normalized state evaluation indicators and combining the acquired subjective will of the experts to obtain the state evaluation indicators after subjective sorting;

[0092] Step S312: subjectively assigning relative importance of adjacent state evaluation indicators according to the state evaluation indicators after subjective sorting to obtain an importance ratio b;

[0093] Step S313: Calculate the subjective evaluation weight w according to the importance ratio b 主 .

[0094]

[0095] Among them, m is the number of state evaluation indicators, and k represents the kth state indicator.

[0096] Step S32: Based on the normalized state evaluation index, the coefficient of variation method is used to calculate the objective evaluation weight w of the state evaluation index. 客 ; Different from the subjective weight of the evaluation index, the objective weight is based on the actual value of the index, obtained through mathematical calculation and analysis of real data, and reflects the actual situation between the index data. The coefficient of variation method is also called the information weight method. Its idea is to use the coefficient of variation of the data to assign weights, reflecting that the greater the difference in the actual value of the index, the greater the gap between the evaluated units. Therefore, the size of the coefficient of variation reflects the amount of information it carries, indicating the size of the weight.

[0097] The specific operation of step S32 is: according to the standard deviation σ of the state evaluation index k , the mean of the status evaluation index Calculate the coefficient of variation ε of the state evaluation index k , and then calculate the objective evaluation weight w according to the coefficient of variation 客 .

[0098]

[0099] Step S33: Based on the subjective evaluation weight and the objective evaluation weight, the Lagrange optimal multiplier method is used to calculate the comprehensive evaluation weight. The method of comprehensive ordinal relationship analysis and coefficient of variation method makes the weight of each indicator more reasonable and objective, which not only reflects the experience of experts, but also takes into account the information of the indicator itself.

[0100] Step S4: Establish an evaluation function according to the comprehensive evaluation weight to calculate the evaluation value and obtain the low-voltage distribution network status evaluation result.

[0101] The specific operation of step S4 is: constructing an evaluation function vector according to the comprehensive evaluation weight, obtaining a state evaluation function calculation evaluation value, and obtaining a low-voltage distribution network state evaluation result according to the evaluation.

[0102] The low-voltage distribution network status assessment result obtained according to the assessment specifically includes: if the assessment value is greater than 0 and less than 0.25, the low-voltage distribution network status is assessed as excellent; if the assessment value is greater than 0.25 and less than 0.5, the low-voltage distribution network status is assessed as good; if the assessment value is greater than 0.5 and less than 0.75, the low-voltage distribution network status is assessed as passing; if the assessment value is greater than 0.75 and less than 1, the low-voltage distribution network status is assessed as failing.

[0103] This embodiment evaluates the state of the low-voltage distribution network by constructing evaluation indicators, and summarizes the power data collected from the low-voltage distribution in units of substations. After preprocessing the power data, the order relationship analysis method and the coefficient of variation method are used to obtain the subjective weight and objective weight of each evaluation indicator, and the comprehensive weight of each indicator is obtained by the Lagrange optimal multiplier method. Finally, the state evaluation function is obtained and the function value is uploaded to the cloud master station. The state of each low-voltage distribution network is comprehensively evaluated according to the size of the evaluation function value.

[0104] The other parts of this embodiment are the same as those of the above-mentioned embodiment 1, and thus will not be described in detail.

[0105] Embodiment 3:

[0106] Based on any one of the above-mentioned embodiments 1-2, this embodiment proposes a low-voltage distribution network status assessment system based on the above-mentioned low-voltage distribution network status assessment method, which is used to execute the above-mentioned low-voltage distribution network status assessment method, including a collection unit, an indicator construction unit, a weight calculation unit, and an assessment unit;

[0107] The collection unit is used to collect power data from the low-voltage distribution network and pre-process it;

[0108] The indicator construction unit is used to construct a state evaluation indicator according to the preprocessed power data and perform normalization processing;

[0109] The weight calculation unit is used to calculate the subjective weight and objective evaluation weight of the state evaluation index according to the normalized state evaluation index by adopting a subjective and objective method to obtain a comprehensive evaluation weight;

[0110] The evaluation unit is used to establish an evaluation function according to the comprehensive evaluation weight to calculate the evaluation value and obtain the low-voltage distribution network status evaluation result.

[0111] This embodiment further proposes an electronic device, including a memory and a processor; a computer program is stored in the memory; when the computer program is executed on the processor, the above-mentioned low-voltage distribution network status assessment method is implemented.

[0112] This embodiment further proposes a computer-readable storage medium, on which computer instructions are stored; when the computer instructions are executed on the above-mentioned electronic device, the above-mentioned low-voltage distribution network status assessment method is implemented.

[0113] The other parts of this embodiment are the same as any one of the above-mentioned embodiments 1-2, so they will not be repeated here.

[0114] The processor involved in the embodiments of the present application may be a chip. For example, it may be a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), a system on chip (SoC), a central processor unit (CPU), a network processor (NP), a digital signal processor (DSP), a microcontroller unit (MCU), a programmable logic device (PLD), or other integrated chips.

[0115] The memory involved in the embodiments of the present application may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of RAM are available, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), and direct RAM (DR RAM). It should be noted that the memory of the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0116] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0117] Those of ordinary skill in the art will appreciate that the modules and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0118] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and modules described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0119] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the modules is only a logical function division. There may be other division methods in actual implementation, such as multiple modules or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or modules, which can be electrical, mechanical or other forms.

[0120] The modules described as separate components may or may not be physically separated, and the components shown as modules may or may not be physical modules, that is, they may be located in one device or distributed on multiple devices. Some or all of the modules may be selected according to actual needs to achieve the purpose of the present embodiment.

[0121] In addition, each functional module in each embodiment of the present application may be integrated into one device, or each module may exist physically separately, or two or more modules may be integrated into one device.

[0122] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using a software program, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When loading and executing computer program instructions on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions may be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be transmitted from a website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (Digital Subscriber Line, DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website site, computer, server or data center. The computer-readable storage medium may be any available medium that a computer can access or may contain one or more servers, data centers and other data storage devices that can be integrated with a medium. The available medium may be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, a DVD), or a semiconductor medium (eg, a solid state disk (SSD)).

[0123] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A method for evaluating the state of a low voltage distribution network, characterized in that: The specific steps include: Step S1: Collecting power data from the low voltage distribution network and preprocessing; Step S2: constructing a state evaluation index based on the preprocessed power data and normalizing it; Step S3: According to the normalized state evaluation index, the subjective weight and objective evaluation weight of the state evaluation index are calculated by combining subjective and objective methods to obtain the comprehensive evaluation weight; Step S4: Establish an evaluation function according to the comprehensive evaluation weight to calculate the evaluation value and obtain the low-voltage distribution network status evaluation result.

2. A low voltage distribution network status assessment method according to claim 1, characterized in that: The step S2 specifically includes the following steps: Step S21: Calculate the average value from the geometric center of the power supply range of the low-voltage distribution network area to the power supply boundary of the low-voltage distribution network area according to the low-voltage distribution network area positioning system data obtained from the pre-processed power data, and use it as the first state evaluation indicator; Step S22: Calculate the comprehensive line loss rate of the low-voltage distribution network based on the power supply amount and the power sales amount of the low-voltage distribution network area obtained from the pre-processed power data, and use it as the second state evaluation indicator; Step S23: Calculate the transformer load rate according to the actual active power of the low-voltage distribution network transformer and the rated active power of the low-voltage distribution network transformer obtained from the pre-processed power data, and use it as the third state evaluation indicator; Step S24: Calculate the voltage qualification rate according to the voltage over-limit time and power supply time obtained from the pre-processed power data, and use it as the fourth state evaluation indicator; Step S25: Calculate the three-phase load imbalance according to the A-phase load, B-phase load, and C-phase load obtained from the pre-processed power data, and use it as the fifth state evaluation indicator; Step S26: Calculate the perception data qualification rate based on the power perception data and power abnormality data obtained from the pre-processed power data, and use it as the sixth state evaluation indicator.

3. A low voltage distribution network status assessment method according to claim 1, characterized in that: The step S3 specifically comprises the following steps: Step S31: according to the normalized state evaluation index, the order relationship analysis method is called to calculate the subjective evaluation weight of the state evaluation index; Step S32: according to the normalized state evaluation index, the coefficient of variation method is called to calculate the objective evaluation weight of the state evaluation index; Step S33: Based on the subjective evaluation weight and the objective evaluation weight, the Lagrange optimal multiplier method is called to calculate the comprehensive evaluation weight.

4. A low voltage distribution network status assessment method according to claim 1, characterized in that: Step S31 specifically includes the following steps: Step S311: sorting the state evaluation indicators according to the importance of the normalized state evaluation indicators and combining the acquired subjective will of the experts to obtain the state evaluation indicators after subjective sorting; Step S312: subjectively assigning relative importance of adjacent state evaluation indicators according to the subjectively sorted state evaluation indicators to obtain an importance ratio; Step S313: Calculate the subjective evaluation weight according to the importance ratio.

5. A low voltage distribution network status assessment method according to claim 1, characterized in that: The specific operation of step S32 is: calculating the coefficient of variation of the state evaluation index according to the standard deviation of the state evaluation index and the mean of the state evaluation index, and then calculating the objective evaluation weight according to the coefficient of variation.

6. A low voltage distribution network status assessment method according to claim 1, characterized in that: The specific operation of step S4 is: constructing an evaluation function vector according to the comprehensive evaluation weight, obtaining a state evaluation function calculation evaluation value, and obtaining a low-voltage distribution network state evaluation result according to the evaluation.

7. A method for evaluating the status of a low-voltage distribution network according to claim 6, characterized in that: The low-voltage distribution network status assessment result obtained according to the assessment specifically includes: if the assessment value is greater than 0 and less than 0.25, the low-voltage distribution network status is assessed as excellent; if the assessment value is greater than 0.25 and less than 0.5, the low-voltage distribution network status is assessed as good; if the assessment value is greater than 0.5 and less than 0.75, the low-voltage distribution network status is assessed as passing; if the assessment value is greater than 0.75 and less than 1, the low-voltage distribution network status is assessed as failing.

8. A low voltage distribution network status assessment system, used to execute the low voltage distribution network status assessment method according to claim 1, characterized in that: It includes a collection unit, an indicator construction unit, a weight calculation unit, and an evaluation unit; The collection unit is used to collect power data from the low-voltage distribution network and pre-process it; The indicator construction unit is used to construct a state evaluation indicator according to the preprocessed power data and perform normalization processing; The weight calculation unit is used to calculate the subjective weight and objective evaluation weight of the state evaluation index according to the normalized state evaluation index by adopting a subjective and objective method to obtain a comprehensive evaluation weight; The evaluation unit is used to establish an evaluation function according to the comprehensive evaluation weight to calculate the evaluation value and obtain the low-voltage distribution network status evaluation result.

9. An electronic device, characterized in that: It comprises a memory and a processor; a computer program is stored in the memory; when the computer program is executed on the processor, the low-voltage distribution network status assessment method as described in any one of claims 1 to 7 is implemented.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions; when the computer instructions are executed on the electronic device as described in claim 9, the low-voltage distribution network status assessment method as described in any one of claims 1-7 is implemented.

Images