Method for shortening calculation time of openable capacity of distribution network line

Abstract

The invention discloses a method for shortening open capacity calculation time of a distribution network line. The method comprises the following steps: constructing an open current value empirical improvement model of the distribution network line; calculating a superposed maximum load by using a topological contact relationship; through multi-factor checking, evaluating the openable capacity through equipment transfer risk; and visible display of the openable capacity is realized. A distribution network line openable current value empirical improvement model is constructed, a developed distribution network line openable capacity visualization application platform is utilized to carry out field test calculation, batch line object selection, contact transfer line checking and date check are carried out for calculation, a small amount of abnormal data is perfected, and the distribution network line openable capacity visualization application platform is established. And an openable capacity calculation result value is exported after comparison with a previous result, so that the openable capacity calculation time of the distribution network line is effectively shortened, and the power distribution regulation and control efficiency is optimized.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic openable capacity calculation, and in particular to a method for shortening the calculation time of the openable capacity of a distribution network line. Background Art

[0002] The 10(20)kV distribution network is directly facing the power users, with a large scale and complex connections. How to ensure the safe and stable power supply of the distribution network has always been the focus of the power industry. Affected by historical evolution and the imbalance of power grid development, the load carried by most distribution networks is uneven. There has long been a problem that some lines are lightly loaded while other lines are extremely overloaded. Distribution control personnel lack intuitive and timely data information on the open margin of distribution network lines. When analyzing the full shutdown of substations and comparing the load reconnection of distribution networks, they generally make judgments based on the "manual analysis + experience estimation" model, which brings potential risks such as high risk of equipment load and unscientific load distribution. At the same time, when planning the construction of distribution networks, power grid development and operation and inspection personnel also lack timely and effective open capacity data support, which brings many challenges to the construction and operation and maintenance of distribution networks.

[0003] Data shows that in the process of carrying out traditional business expansion, the company's marketing department and omnipotent institute personnel lack data information on the power supply capacity of the lines in their jurisdiction, and judge the access based on experience, resulting in low efficiency of business expansion registration, unscientific load distribution, and blind access of seasonal and temporary loads. Social and economic development and industrial structure adjustment have led to continuous changes in electricity consumption characteristics, and the power grid planning is not designed based on the user's maximum superimposed load, but rather meets the user's electricity consumption and business expansion needs through the principle of sharing the equipment's open capacity. The above premise requires timely evaluation of the open capacity of 10(20)kV distribution network lines, but the existing open capacity calculation relies entirely on manual comparison, which has the disadvantages of being too time-consuming, inefficient, low-precision, and lacking sustainability, and can no longer meet the needs of production and marketing departments.

[0004] Chinese patent document CN107671414A discloses a "data mining-based calculation method for photovoltaic open capacity". The key points of its technical solution are: S100, establish a calculation system for the maximum photovoltaic open capacity of the power grid, and calculate the maximum photovoltaic open capacity of the power grid; S200, on the basis of the system reaching the maximum photovoltaic open capacity of the power grid, establish a main transformer and line load rate balancing model, so that the main transformer load and line load can be evenly distributed, and the current can be evenly distributed in the power grid. The above technical solution is time-consuming and inefficient as a whole, and it is difficult to meet production and use needs. Summary of the invention

[0005] The present invention mainly solves the technical problems that the original technical solutions are time-consuming, inefficient and difficult to meet the production and use needs. It provides a method for shortening the calculation time of the openable capacity of distribution network lines, constructs an empirical improvement model of the openable current value of distribution network lines, uses the developed distribution network line openable capacity visualization application platform to perform on-site test calculations, performs batch line object selection, liaison and transfer line verification, and date selection for calculations, and improves a small amount of abnormal data. After comparing with the previous result, the calculation result value of the openable capacity is derived, which effectively shortens the calculation time of the openable capacity of distribution network lines and optimizes the distribution control efficiency.

[0006] The above technical problem of the present invention is mainly solved by the following technical solution: The present invention comprises the following steps:

[0007] S1 builds an empirical improvement model for the open current value of distribution network lines;

[0008] S2 uses the topological connection relationship to calculate the maximum superimposed load;

[0009] S3 uses multi-factor verification to assess the capacity that can be opened based on the risk of equipment transfer;

[0010] S4 enables visual display of open capacity.

[0011] The developed distribution network line open capacity visualization application platform was used for field test calculation. According to the operation instructions, batch line objects were selected, the contact transfer lines were checked, and the date was checked for calculation. A small amount of abnormal data was improved, and the open capacity calculation result value was derived after comparison with the previous result. The actual superposition transfer load time was about 0.28 hours, which was much less than the 3.15 hours manually consumed in Excel, and the goal was verified.

[0012] As a preferred embodiment, the step S1 specifically includes the following factors: the factors to be considered in constructing the empirical improvement model of the open current value of the distribution network line include: the maximum allowable current I m ","The highest load current in history I h ”、Equivalent output of new energy I d , "N-1" principle, calculate the open current value I k ,

[0013] I k =90%*I m -I h -I d .

[0014] As a preference, the step S1 also considers the possibility that the output of new energy is not synchronized with the maximum load, superimposes the possibility that the actual maximum load appears at the sub-maximum value, and is affected by the sudden "thorny" load curve, and applies the current curve correction parameters and the synchronous envelope load rolling calculation model. After actual work verification, the model is easy to implement and more accurate.

[0015] Preferably, the step S2 specifically includes:

[0016] S2.1 Use the system line ledger to obtain the line name of each substation;

[0017] S2.2 According to the topological relationship of the contact points, obtain the line on this side and the line on the opposite side;

[0018] S2.3 collects the line limits at different temperatures, the maximum current of the line on this side, and the maximum current of the line on the opposite side as management standards;

[0019] S2.4 Provide daily, monthly and annual maximum superimposed loads according to daily management needs.

[0020] Using the D5200 and PMS3.0 system line ledger, the line name of each substation is obtained.

[0021] Preferably, the step S3 specifically includes, through the equipment current limit, interval CT ratio, transfer protection sensitivity and transfer power quality review, ensuring that the layering and zoning of each distribution network line and the transfer capacity meet the standards. Multiple calculation and approval methods are used to accurately evaluate the open capacity under the premise of ensuring efficiency.

[0022] Preferably, the step S3 further uses the section switch as a partition node, confirms the load of each partition, and formulates the maximum open capacity standard based on the comprehensive analysis of line parameters. Using the section switch as a partition node can achieve more accurate regional analysis and precise control.

[0023] Preferably, the step S4 specifically includes displaying the open capacity according to the risk assessment of equipment transfer, and representing the lines that can accept transfer and have normal load after transfer in white; representing the lines that may have overload risks in the optimal transfer plan and are recommended to be operated with caution in orange; and representing the lines that may have overload risks in the optimal transfer plan and are recommended to consider segmented transfer in red.

[0024] As a preference, when the entire line on the opposite side is transferred, the line may be overloaded, and the line is transferred in sections to display the open capacity. The areas where users in this section may be overloaded when powered by the opposite line and cautious operation is recommended are indicated in orange; the areas where users in this section may be overloaded when powered by the opposite line and power transfer is not recommended are indicated in red.

[0025] The beneficial effects of the present invention are as follows: by constructing an empirical improvement model for the open current value of distribution network lines, using the developed distribution network line open capacity visualization application platform to perform field test calculations, batch line object selection, connection and transfer line verification, date selection for calculations, and improving a small amount of abnormal data, the open capacity calculation result value is derived after comparison with the previous result, effectively shortening the calculation time of the distribution network line open capacity and optimizing the distribution control efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a flow chart of the present invention.

[0027] Figure 2 It is an open capacity export result diagram of the present invention.

[0028] Figure 3 The invention discloses an open-capacity transformer substation line interface diagram.

[0029] Figure 4 It is a data calculation time comparison chart of the present invention. DETAILED DESCRIPTION

[0030] The technical solution of the present invention is further specifically described below through embodiments and in conjunction with the accompanying drawings.

[0031] Embodiment: A method of shortening the calculation time of the available capacity of the distribution network line in this embodiment is as follows: Figure 1 As shown, the following steps are included:

[0032] S1 builds an empirical improvement model for the open current value of distribution network lines. The factors to be considered in building the empirical improvement model for the open current value of distribution network lines include the "maximum allowable current I m ","The highest load current in history I h ”、Equivalent output of new energy I d , "N-1" principle, calculate the open current value I k ,

[0033] I k =90%*I m -I h -I d

[0034] At the same time, considering the possibility of non-synchronization between the output of new energy and the maximum load, the possibility that the actual maximum load may appear at the sub-maximum value, and the influence of the sudden "thorny" load curve, the current curve correction parameters and the synchronous envelope load rolling calculation model are applied. After actual work verification, the model is easy to implement and more accurate.

[0035] S2 uses the topological connection relationship to calculate the maximum superimposed load, including:

[0036] Use the system line ledger to obtain the line name of each substation;

[0037] According to the topological relationship of the contact points, obtain the lines on this side and the lines on the other side;

[0038] The limits of the lines at different temperatures, the maximum current of the lines on this side, and the maximum current of the lines on the opposite side are collected as management standards, and the maximum superimposed loads for each day, month, and year are provided according to daily management needs.

[0039] S3 uses multi-factor verification to evaluate the open capacity based on the risk of equipment transfer. Through the review of equipment current limit, interval CT ratio, transfer protection sensitivity and transferred power quality, it ensures that the layering and partitioning of each distribution network line and the transfer capacity meet the standards. Multiple calculation and verification methods are used to accurately evaluate the open capacity under the premise of ensuring efficiency. Further, the section switch is used as the partition node to confirm the load carried by each partition, and the maximum open capacity standard is formulated based on the comprehensive analysis of line parameters. The open capacity export results are as follows: Figure 2 As shown in the figure, the segment switches are used as partition nodes to achieve more accurate regional analysis and precise control.

[0040] S4 enables visual display of open capacity.

[0041] The available capacity based on the risk assessment of equipment transfer is displayed, such as Figure 3 As shown, the lines that can accept power transfer and have normal load after the transfer are represented in white; the lines where the optimal power transfer plan may have a risk of overloading and it is recommended to operate with caution are represented in orange; the lines where the optimal power transfer plan may have a risk of overloading and it is recommended to consider segmented power transfer are represented in red.

[0042] When the entire line on the opposite side is transferred, the line may be overloaded, and the line is transferred in sections to display the open capacity. The areas where users in this section may be overloaded when powered by the opposite line and cautious operation is recommended are indicated in orange; the areas where users in this section may be overloaded when powered by the opposite line and power transfer is not recommended are indicated in red.

[0043] like Figure 4 As shown in the figure, by comparing the chart, it can be clearly found that the time for the superimposed transfer load verification is shortened from 3.15 hours to 0.35 hours, and the time consumption ratio is reduced from the original 84.67% to 38.05%. The main problems have been well solved. The time for synchronous data calculation has been shortened from 3.72 hours to 0.92 hours, which is effectively improved overall. The fundamental reason is that the application of the open capacity visualization automatic verification function has essentially changed the lag and delay of the previous manual item-by-item verification, saving a lot of time and shortening the calculation time of the open capacity of the distribution network line as a whole.

Claims

1. A method for shortening the calculation time of the available capacity of a distribution network line, characterized in that: The following steps are involved: S1 builds an empirical improvement model for the open current value of distribution network lines; S2 uses the topological connection relationship to calculate the maximum superimposed load; S3 uses multi-factor verification to assess the capacity that can be opened based on the risk of equipment transfer; S4 enables visual display of open capacity.

2. A method for shortening the calculation time of the available capacity of distribution network lines according to claim 1, characterized in that: The step S1 specifically includes the following factors: the factors to be considered in constructing the empirical improvement model of the open current value of the distribution network line include: the maximum allowable current I m ", "Historical maximum load current I h ”、Equivalent output of new energy I d 、"N-1" principle, calculate the open current value I k , I k =90%*I m -I h -I d 。 3. A method for shortening the calculation time of the available capacity of a distribution network line according to claim 1 or 2, characterized in that: The step S1 simultaneously considers the possibility of the new energy output being asynchronous with the maximum load, superimposes the possibility that the actual maximum load may appear at the submaximum value, and is affected by the sudden "thorny" load curve, and applies the current curve correction parameters and the synchronous envelope load rolling calculation model.

4. A method for shortening the calculation time of the available capacity of distribution network lines according to claim 1, characterized in that: The step S2 specifically includes: S2.1 Use the system line ledger to obtain the line name of each substation; S2.2 According to the topological relationship of the contact points, obtain the line on this side and the line on the opposite side; S2.3 collects the line limits at different temperatures, the maximum current of the line on this side, and the maximum current of the line on the opposite side as management standards; S2.4 Provide daily, monthly and annual maximum superimposed loads according to daily management needs.

5. A method for shortening the calculation time of the available capacity of distribution network lines according to claim 1, characterized in that: The step S3 specifically includes ensuring that the layering and zoning of each distribution network line and the transfer capacity meet the standards through reviewing the equipment current limit, the interval CT ratio, the transfer protection sensitivity and the transferred power quality.

6. A method for shortening the calculation time of the available capacity of a distribution network line according to claim 1 or 6, characterized in that: The step S3 further uses the section switch as a partition node, confirms the load carried by each partition, and formulates the maximum open capacity standard based on a comprehensive analysis of line parameters.

7. A method for shortening the calculation time of the available capacity of distribution network lines according to claim 1, characterized in that: The step S4 specifically includes displaying the open capacity according to the risk assessment of equipment transfer, representing the lines that can accept transfer and have normal load after transfer in white; representing the lines that may have overload risks in the optimal transfer plan and are recommended to be operated with caution in orange; and representing the lines that may have overload risks in the optimal transfer plan and are recommended to consider segmented transfer in red.

8. A method for shortening the calculation time of the available capacity of a distribution network line according to claim 1 or 7, characterized in that: When the entire line on the opposite side is transferred, the line may be overloaded, and the line is transferred in sections to display the open capacity. The areas where users in this section may be overloaded when powered by the opposite line and cautious operation is recommended are indicated in orange; the areas where users in this section may be overloaded when powered by the opposite line and power transfer is not recommended are indicated in red.

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