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CN-121997608-A - Topology evaluation and decision-making method and device for offshore wind farm direct current collector system based on combined weighting and TOPSIS

CN121997608ACN 121997608 ACN121997608 ACN 121997608ACN-121997608-A

Abstract

The invention provides a topology evaluation and decision-making method and device of a marine wind power plant direct current collector system based on combined weighting and TOPSIS, wherein the method comprises the steps of obtaining a plurality of alternative topology schemes, constructing a comprehensive evaluation index system, and preprocessing each index in the comprehensive evaluation index system to obtain a standardized index matrix; based on a standardized index matrix, obtaining subjective weights of all indexes by adopting an analytic hierarchy process, obtaining objective weights of all indexes by adopting an entropy value process, fusing the subjective weights with the objective weights based on a preset fusion principle to obtain combined weights, performing hard screening on alternative topology schemes based on preset engineering constraints, comprehensively evaluating the alternative topology schemes subjected to hard screening by adopting an approximate ideal solution sequencing process based on the combined weights, calculating the relative closeness of each alternative topology scheme and positive and negative ideal solutions, and outputting comprehensive scores, scheme sequencing and optimal recommended schemes of the alternative topology schemes based on the relative closeness.

Inventors

  • CHE YANBO
  • WANG LEI
  • JIANG NAN
  • LI PEIYI
  • PENG JIN

Assignees

  • 天津大学

Dates

Publication Date
20260508
Application Date
20260203

Claims (10)

  1. 1. The topology evaluation and decision method for the offshore wind farm direct current collector system based on the combined weighting and TOPSIS is characterized by comprising the following steps: acquiring a plurality of alternative topology schemes of a direct current collecting system of the offshore wind farm, constructing a comprehensive evaluation index system, and preprocessing each index in the comprehensive evaluation index system to obtain a standardized index matrix; Based on the standardized index matrix, obtaining subjective weights of all indexes by adopting an analytic hierarchy process, and obtaining objective weights of all indexes by adopting an entropy value process; fusing the subjective weight and the objective weight based on a preset fusion principle to obtain a combined weight; performing hard screening on the alternative topology scheme based on preset engineering constraint; Based on the combination weight, comprehensively evaluating the alternative topology schemes through hard screening by adopting an approximation ideal solution sorting method, and calculating the relative closeness between each alternative topology scheme and positive and negative ideal solutions; Based on the relative closeness, the comprehensive scores, the scheme ordering and the optimal recommended schemes of the alternative topology schemes are output.
  2. 2. The method of claim 1, wherein the indexes in the comprehensive evaluation index system comprise an energy efficiency index, a reliability index and a stability index; the energy efficiency index comprises annual loss power consumption and line loss rate; the reliability index comprises expected unpowered quantity, N-1 passing rate and fault state maximum overload rate; the stability index comprises the maximum deviation of the voltage of the direct current bus, the voltage stability margin and the voltage recovery time after failure.
  3. 3. The method of claim 1, wherein the step of obtaining the subjective weight of each index by using a hierarchical analysis method comprises constructing a judgment matrix to obtain the subjective weight of each index, and performing consistency test on the subjective weights.
  4. 4. The method of claim 1, wherein the predetermined engineering constraints include one or more of a submarine cable thermal stability limit, an N-1 constraint, an upper converter station capacity limit, and a voltage stability margin.
  5. 5. The method according to claim 1, wherein the method further comprises: When evaluating a topology scheme of a direct current collecting system of an offshore wind farm covering multiple scenes, giving a weight beta to each scene s, and determining a single index according to the weight beta Normalization and scoring are carried out after the total; Wherein: Is the original value or statistical value of each index.
  6. 6. The topology evaluation and decision device of the offshore wind farm direct current collector system based on the combined weighting and TOPSIS is used for realizing the method of any one of claims 1-5, and is characterized by comprising a data acquisition and preprocessing module, a weight calculation module, a combined weighting module, a constraint checking module, a TOPSIS comprehensive evaluation module and a result output module; The data acquisition and preprocessing module is used for acquiring a plurality of alternative topology schemes of the direct current collecting system of the offshore wind farm, constructing a comprehensive evaluation index system, and preprocessing each index in the comprehensive evaluation index system to obtain a standardized index matrix; The weight calculation module is used for obtaining subjective weights of all indexes by adopting a hierarchical analysis method based on the standardized index matrix and obtaining objective weights of all indexes by adopting an entropy value method; the combination weighting module is used for fusing the subjective weight and the objective weight based on a preset fusion principle to obtain a combination weight; The constraint checking module is used for carrying out hard screening on the alternative topology scheme based on preset engineering constraint; the TOPSIS comprehensive evaluation module is used for comprehensively evaluating the alternative topology schemes through hard screening by adopting an approximate ideal solution sorting method based on the combination weight, and calculating the relative closeness of each alternative topology scheme and positive and negative ideal solutions; And the result output module is used for outputting comprehensive scores, scheme ordering and optimal recommended schemes of the alternative topology schemes based on the relative closeness.
  7. 7. The apparatus of claim 6, wherein the indicators in the integrated assessment indicator system include an energy efficiency indicator, a reliability indicator, and a stability indicator; the energy efficiency index comprises annual loss power consumption and line loss rate; the reliability index comprises expected unpowered quantity, N-1 passing rate and fault state maximum overload rate; the stability index comprises the maximum deviation of the voltage of the direct current bus, the voltage stability margin and the voltage recovery time after failure.
  8. 8. The apparatus of claim 6 wherein the means for obtaining subjective weights of the indicators using analytic hierarchy process comprises constructing a decision matrix to obtain subjective weights of the indicators, and performing a consistency check on the subjective weights.
  9. 9. The apparatus of claim 6, wherein the predetermined engineering constraints include one or more of a submarine cable thermal stability limit, an N-1 constraint, an upper converter station capacity limit, and a voltage stability margin.
  10. 10. The apparatus of claim 6, wherein the apparatus further comprises: When evaluating a topology scheme of a direct current collecting system of an offshore wind farm covering multiple scenes, giving a weight beta to each scene s, and determining a single index according to the weight beta Normalization and scoring are carried out after the total; Wherein: Is the original value or statistical value of each index.

Description

Topology evaluation and decision-making method and device for offshore wind farm direct current collector system based on combined weighting and TOPSIS Technical Field The invention belongs to the technical field of the optimization design of a direct current collector system of an offshore wind farm, and particularly relates to a topology evaluation and decision-making method and device of the direct current collector system of the offshore wind farm based on combined weighting and TOPSIS, which are suitable for multi-scheme rapid optimization of the direct current collector system of the offshore wind farm under engineering constraint. Background The rapid development of offshore wind power enables the scale of a wind power plant to be increased with the distance from the offshore, and the traditional alternating current collection mode faces the problems of voltage drop, reactive compensation pressure, high loss and the like in long-distance and large-capacity scenes. The direct current collecting system has potential advantages in deep open sea and large base scenes due to low loss and good controllability. The existing research based on multi-index decision methods such as AHP, entropy weight method and TOPSIS focuses on scenes such as AC power grid planning, power transmission channel site selection, comprehensive energy station site selection and volume determination, and the like, and evaluation indexes are concentrated on macroscopic indexes such as line scale and running loss, and are attached with simple power supply reliability or voltage qualification rate indexes at most. For the novel application scene of the direct current collecting system of the offshore wind farm, the special key operation characteristics of the direct current system such as sea cable thermal stability limit, direct current bus voltage deviation, voltage stability margin, voltage recovery time after direct current fault and the like are not independently modeled and explicitly quantized, and the operation risk of the direct current collecting system under fault and disturbance working conditions is difficult to accurately reflect in the existing method. In addition, the existing multi-index decision method mostly adopts a soft constraint or penalty function form in constraint processing, namely, engineering constraints such as N-1 safety, cable current-carrying capacity out-of-limit, upper limit of converter station capacity and the like are converted into penalty items or auxiliary indexes to participate in comprehensive scoring, and a scheme which does not meet the engineering constraints is not subjected to hard rejection before scoring. The method is easy to cause the problems that some schemes are in the front on the comprehensive score, but under the actual engineering condition, serious hidden dangers such as long-term overload of sea cables, unstable voltage of a converter station and the like exist, and the decision result is disjointed with the engineering implementation. As the capacity of offshore wind farms increases and the offshore distance increases, the complexity of the topology structure and the number of alternatives of the direct current collecting system rapidly increases, and if the general multi-index decision method which does not fully consider the characteristics of the direct current collecting system and lacks engineering constraint hard screening mechanisms is still adopted, it is difficult to screen out schemes which not only meet engineering constraints but also are superior in comprehensive aspects of energy efficiency, reliability and stability in time, and design efficiency and decision reliability are required to be improved. For example, GB 38755-2019 sets clear requirements on N-1 safety and voltage stability, GB/T2900.13-2008 electrical engineering term reliability and service quality sets forth concepts and terms such as power system adequacy, safety, outage event and expected value of shortage (EENS) in the system in the items 2.21-2.30, and DL/T793.1-2017 power generation equipment reliability evaluation procedure part 1: general rule sets forth a statistical method of reliability indexes such as the use, availability, unavailable state division and availability coefficient, outage coefficient of a power generating set and auxiliary equipment, and the like of a wind power generation equipment reliability evaluation technical file issued by an electric power reliability management department (for example, wind power generation equipment reliability evaluation procedure (test operation) and subsequent revision version of the wind power generation equipment reliability evaluation procedure programmed by the electric power reliability management center of China electric power enterprise) sets and refines the state division and electric quantity statistics caliber of wind power generation plants; GB/T40267-2021 provides a unified method for power transmission line loss calculation in t