CN-122000946-A - Method, equipment and medium for improving bearing capacity of power distribution network based on node load alignment

CN122000946ACN 122000946 ACN122000946 ACN 122000946ACN-122000946-A

Abstract

The invention relates to a method, equipment and medium for improving the bearing capacity of a power distribution network based on a node load guideline, belonging to the field of improving the bearing capacity of the power distribution network, wherein the method comprises the steps of acquiring power distribution network data and carrying out probability modeling to generate an uncertainty scene set; the method comprises the steps of constructing a node load quasi-line optimization model, introducing a bearing capacity lifting gain item and a quasi-line smoothing regular item to construct an objective function, constructing a physical constraint condition, and solving to obtain a node load quasi-line optimal form, respectively executing simulation in an independent operation mode and a quasi-line cooperative interaction mode aiming at each random scene in an uncertainty scene set, recording evaluation indexes in the two modes, and calculating a bearing capacity lifting effect index according to the evaluation indexes to guide planning decision, wherein the quasi-line cooperative interaction mode is to coordinate an input original load into the node load quasi-line optimal form by using a flexible interconnection device. Compared with the prior art, the invention has the advantages of high cooperative efficiency, visual bearing capacity improving effect and the like.

Inventors

Lu Quanha
YANG YI
ZHANG ZHAO
CHEN GUOYU
XU ZHEN
XIA YUJIAN
Tu Huaiguang
Zhao tianyang
QIAN JIA
TANG YI

Assignees

国网上海市电力公司

Dates

Publication Date: 20260508
Application Date: 20260410

Claims (10)

1. The method for improving the bearing capacity of the power distribution network based on the node load guideline is characterized by comprising the following steps of: S1, acquiring related uncertainty data of a power distribution network, and performing probability modeling to generate an uncertainty scene set; S2, taking an uncertainty scene as input, constructing a node load guideline optimization model, introducing a bearing capacity improvement gain item and a guideline smoothing regularization item on the basis of energy storage and power rejection cost and inter-station mutual-aid cost to construct an objective function, constructing a physical constraint condition, and solving the model to obtain a node load guideline optimal form; S3, respectively executing simulation in an independent operation mode and a quasi-linear collaborative interaction mode aiming at each random scene in the uncertainty scene set, recording the maximum bearing load, the peak load rate and the waste capacity in the two modes, and calculating a bearing capacity lifting effect index based on the maximum bearing load, the peak load rate and the waste capacity to guide planning decision, wherein the quasi-linear collaborative interaction mode is to coordinate an input original load into the node load quasi-linear optimal form by using a flexible interconnection device.
2. The method for improving the bearing capacity of the power distribution network based on the node load guideline according to claim 1, wherein the probability modeling comprises probability modeling of distributed photovoltaic output, probability modeling of basic conventional load and unordered charging load modeling of electric vehicles, photovoltaic output, basic load and electric vehicle load of each area at each moment are respectively obtained, the sum of the basic load and the electric vehicle load of each area at each moment is a total electricity utilization load, and the sum of the basic load and the electric vehicle load of each area at each moment and the photovoltaic output of each area at each moment are used as input of a node load guideline optimization model.
3. The method for improving the bearing capacity of a power distribution network based on node load guideline according to claim 1, wherein the objective function is expressed as: ; Wherein, the Is the first The energy storage cost of each station area, Is the first Discarding electricity cost of each station area; Is the total number of the areas; The mutual cost between stations is achieved; benefit for bearing capacity Is used for the coefficient of (a), , 、、 For the weight coefficient of each benefit, For the equivalent bearer capacity gain, For the total length of time, For a set transformer load factor safety threshold, Is the first The individual areas are at The actual load rate after the time optimization, Is the first The transformer capacity of the individual transformer areas, The new energy bearing margin index is used; For the regularization coefficient(s), Is the first Quasi-linear smoothing penalty values for the individual zones.
4. The method for improving the bearing capacity of a power distribution network based on node load guideline according to claim 1, wherein the physical constraint condition comprises: The power balance constraint of the station areas ensures the real-time balance of source, load, storage and mutual power in each station area; the capacity constraint of the transformer, namely the net power exchanged between each station area and the upper power grid must not exceed the rated capacity of the transformer; The power transmission distribution factor is utilized to map the node injection power to the power flow of a specific line, so as to ensure that the power flow does not exceed the limit; the capacity constraint of the flexible interconnection device, namely the capacity of the flexible interconnection device of the connection station area must not exceed the rated capacity range; and the operation constraint of the energy storage system is that the energy storage charge state is maintained in a preset range, and the charge state at the current moment is determined by the charge state at the last moment, the current charge and discharge power, the charge and discharge efficiency and the rated capacity of the battery.
5. The method for improving the bearing capacity of the power distribution network based on the node load guideline according to claim 2, wherein the solving the model to obtain the optimal form of the node load guideline is specifically as follows: The scene data comprising the total electric load and the photovoltaic output generated in the step S1 is used as input, a mathematical optimization solver is used for solving based on the constructed objective function and the physical constraint condition to obtain a key decision variable value, wherein the key decision variable value comprises the mutual power of each regional standard line and the flexible interconnection device as the optimal form of the node load standard line, and the solving process ensures that the optimization of node load distribution is realized under the condition that the system meets the safety constraint condition by coordinating the node load standard line, the energy storage charge and discharge and the inter-regional SOP mutual power, thereby reducing the local overload risk and improving the carrying capacity of the system on source load fluctuation.
6. The method for improving the bearing capacity of the power distribution network based on the node load guideline according to claim 1, wherein in the independent operation mode, a flexible interconnection device between the stations is not started, each station operates independently, and the operation rule is that each station only depends on the capacity of a local transformer and energy storage resources to adjust power, the stations do not mutually balance power, and if the photovoltaic output exceeds the local absorption capacity, the power discarding is generated; and (2) in the quasi-linear cooperative mutual-aid mode, adding a flexible interconnection device into the system for regulation and control, performing operation coordination by using the node load quasi-linear optimization model constructed in the step (S2), and recording the optimized maximum load, the optimized peak load rate and the optimized electric quantity after discarding in the mode.
7. The method for improving the bearing capacity of a power distribution network based on node load guideline according to claim 1, wherein the bearing capacity improving effect index comprises an expected equivalent bearing capacity gain, a bearing capacity improving rate confidence level, a new energy bearing margin expectation and a load rate balance improving index, wherein, The calculation method of the expected equivalent bearing capacity gain comprises the following steps: ; Wherein, the In order to achieve the desired equivalent bearer capacity gain, For the equivalent bearer capacity gain, Representing the expectations of the calculation in all simulation scenarios, For the number of scenes of the monte carlo simulation, For the total number of zones, For scenes in independent mode of operation Is used for the peak load rate of (a), Scene in quasi-linear collaborative mutual-aid mode Is used for the optimized peak load rate of (a), Is the first Transformer capacity of the individual bays; The calculating method of the bearing capacity lifting rate confidence level comprises the following steps: ; Wherein, the Scene in quasi-linear collaborative mutual-aid mode Is set to the maximum load-bearing capacity after optimization, For scenes in independent mode of operation Is set up to the maximum load-carrying capacity of the vehicle, Is a scene Is used for improving the bearing capacity; defining the confidence probability that the bearing capacity lifting rate exceeds the target value as the bearing capacity lifting rate confidence level: ; Wherein, the Indicating that the load-bearing capacity increase rate reaches the target value Is a function of the probability of (1), Representation of Indicating a function, taking 1 when the condition is met, otherwise taking 0; the method for calculating the new energy bearing margin expectation comprises the following steps: Respectively calculating the areas under two modes In a scene Time of day New energy consumption margin of (2), calculating new energy bearing margin expectation based on the new energy consumption margin : ; Wherein, the Is used as a new energy bearing margin index, For the total length of time, 、 Respectively a standard line collaborative mutual-aid mode and an independent operation mode In a scene Time of day The new energy consumption margin of the system comprises the following steps: ; Wherein, the Is a station area In a scene Time of day Is used for the total electrical load of the vehicle, Is a station area In a scene Time of day Is used for the photovoltaic output of the solar cell, Substituting the new energy consumption margin into the new energy consumption margin of corresponding modes under different modes respectively; the calculating method of the load rate balance improvement index comprises the following steps: ; Wherein, the For the load-factor balance improvement index, For load balancing in quasi-linear cooperative mutual-aid mode, The load balancing degree in the independent operation mode is calculated by the following steps: ; Wherein, the Is a scene The degree of load balancing under the control of the load balancing system, Is a station area In a scene Peak load rate below or peak load rate after optimization, And substituting the peak load rates of all the areas or the average value of the optimized peak load rates into the values in different modes respectively to calculate and obtain the load balance degree in the corresponding mode.
8. The method for improving the bearing capacity of the power distribution network based on the node load guideline according to claim 7, wherein the bearing capacity improving grades of the power distribution network are divided into four grades according to the bearing capacity improving effect index: When the bearing capacity lifting rate confidence level when the target value is a preset first threshold value is greater than a preset first percentage and the expected equivalent bearing capacity gain is greater than the transformer capacity average value of all the transformer areas, the bearing capacity lifting rate confidence level is obviously improved; The method comprises the steps that when the bearing capacity lifting rate confidence level when the target value is a preset second threshold value is larger than a preset second percentage and when the bearing capacity lifting rate confidence level when the target value is a preset first threshold value is smaller than or equal to a preset first percentage, the bearing capacity lifting rate is effectively improved; When the bearing capacity lifting rate confidence level when the target value is a preset second threshold value is smaller than or equal to a preset second percentage and the load rate balance improvement index is larger than a preset third percentage, the auxiliary lifting is improved; and when the bearing capacity lifting rate confidence level when the target value is a preset second threshold value is smaller than or equal to a preset second percentage and the load rate balance improvement index is smaller than or equal to a preset third percentage, the bearing capacity lifting rate confidence level is a lifting limited level.
9. An electronic device comprising a memory and a processor, the memory having stored thereon a computer program, characterized in that the processor, when executing the program, implements the method according to any of claims 1-8.
10. A computer readable storage medium, on which a computer program is stored, characterized in that the program, when executed by a processor, implements the method according to any one of claims 1-8.

Description

Method, equipment and medium for improving bearing capacity of power distribution network based on node load alignment Technical Field The invention relates to the field of power distribution network bearing capacity lifting, in particular to a power distribution network bearing capacity lifting method, equipment and medium based on node load alignment. Background Under the conditions of high-proportion distributed power supply and novel load access, the running state of the power distribution network is changed from a traditional static one-way power supply mode into a complex system with obvious random volatility, time sequence coupling and space correlation. The existing engineering practice shows that uncertainty superposition of photovoltaic output and charging load of an electric automobile on a time scale and a space scale is easy to cause voltage out-of-limit or equipment overload of a platform region and a feeder line in a local period, so that the access scale of newly added source load, namely the problem of the bearing capacity of a power distribution network, is limited. In view of the above problems, the prior art has been studied mainly from the point of view of "post-check" or "boundary calculation". One type of method determines the maximum accessible capacity under the constraint conditions of voltage, current and the like through load flow calculation or probability load flow analysis, and the other type of method relieves local constraint in the running process through means of configuring energy storage, flexible interconnection devices (SOPs) or implementing demand response and the like, so that the bearing capacity is indirectly improved. The related patents generally aim at "out-of-limit cancellation," "power balance," or "local optimum," and regulate a single moment or a limited period of time, for example, chinese patent application CN118014438a. However, in actual operation, the distribution network is not only exposed to an out-of-limit risk at individual moments, but is operated for a long period of time in a state close to the constraint boundary. The existing method generally lacks clear definition of 'ideal running state', and the regulation strategy is often spread around 'out of limit' or not, and does not give a target running track or reference base of nodes or areas on time sequence. Under the condition of frequent source load fluctuation, the regulation and control mode lacking the reference standard easily causes frequent control actions and low resource utilization efficiency, and is difficult to systematically release the potential bearing capacity of the power distribution network. Defects and deficiencies of the prior art: (1) The load bearing capacity assessment results are based on "limit capacity" and lack executable running references. The existing bearing capacity assessment method mostly takes the maximum accessible capacity or the boundary point meeting the constraint as an output result. The result is essentially the upper limit of capacity in a static or statistical sense, and does not answer the problem about which state the load or equipment load rate of each node should be regulated and controlled in the actual operation process. In the absence of an explicit reference line, it is difficult for operators to directly translate the load bearing capacity assessment results into executable operational control targets, resulting in significant misalignments between assessment and regulation. (2) Flexible devices such as SOP are often used for passive correction and do not adequately serve for active lifting of the load. Existing patents and literature on SOPs emphasize their ability to regulate tidal current and support voltage, with control strategies typically triggered after an out-of-limit or imbalance is detected, pertaining to passive regulation. In the absence of a definite line of sight, the power regulation of the SOP is difficult to spread around an "ideal load distribution state" and only removes the out-of-limit in a local area, failing to systematically excavate the potential load-bearing space of the distribution network. (3) The deviation degree of the running state lacks a quantitative reference, and the bearing capacity lifting effect is difficult to describe. In the prior art, indexes such as 'whether to exceed limit', 'out-of-limit probability' and the like are adopted to evaluate the operation safety, but quantitative description is lacking on the degree of deviation of the node load or the equipment load rate from an ideal operation state. Because of the lack of the alignment line as a reference, the effect of improving the bearing capacity can be generally only explained by comparing the maximum access capacity before and after, and the inherent mechanism of improving the bearing capacity is difficult to reveal from the angle of evolution of the running track. Disclosure of Invention The invention aims to overcome the defects of the pri