Power supply capability assessment method based on improved benders decomposition method

Abstract

The invention discloses a power supply capability assessment method based on an improved benders decomposition method. Based on a power supply capability model considering the N-1 static security constraint, the power supply capability assessment method based on an improved benders decomposition method uses the benders decomposition method to solve the problem, and improves a core accident screening method, a feedback set selection method and a cut set feedback method. The power supply capability assessment method based on an improved benders decomposition method includes the steps: in the core accident screening, according to a relaxation matrix, performing off-limit comparison on sub-problems in a non-core accident set, and selecting an accident which enables each optimization variable to off-limit exceed the threshold value to enter the core accident set; in the feedback set screening, forming a feedback set by core sub-problems in which the off-limit degree exceeds the threshold value; and in the cut-set feedback, forming a feedback set by using a plurality of feedback methods and a variable-speed processing technique. The power supply capability assessment method based on an improved benders decomposition method uses the improved benders decomposition method to effectively solve the problem of solving large-scale grid high-dimensional and non-convex nonlinear multi-constraint optimization problems, and can improve computational efficiency, reduce computation time and optimize the computation result on the premise of guaranteeing that the N-1 safety constraint demand issatisfied.

Description

technical field [0001] The invention relates to the field of grid simulation evaluation, in particular to an evaluation method for power supply capacity based on an improved benders decomposition method. Background technique [0002] At present, many urban high-voltage power grids in my country are shallow and multi-ring network structures. With the rapid growth of load and under the requirements of power safety and reliability, understanding the current power supply capacity level of urban power grids is an important analysis basis for power grid dispatching and planning. How to quickly solve the power supply capacity of this type of complex urban power grid has become a problem of great concern to the industry. [0003] Research on the evaluation method of power supply capacity, the literature "Mohamed Xiaban, Liu Haoming, Li Weixing, etc. Calculation of available transmission capacity based on Benders decomposition algorithm under static security constraints [J]. Chinese ...

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Problems solved by technology

[0003] Research on the evaluation method of power supply capacity, the literature "Mohamed Xiaban, Liu Haoming, Li Weixing, etc. Calculation of available transmission capacity based on Benders decomposition algorithm under static security constraints [J]. Chinese Journal of Electrical Engineering. 2003 (08 ):8‐12" proposed a calculation method based on the benders decomposition method to solve the available transmission capacity. Compared with the general solution method, the benders decomposition method has computational advantages in terms of time and results in large-scale systems, but the above literature The adopted parallel strategy iteration efficiency is low; the literature "Jing Zhaoxia, Wang Hongyi, Wu Qinghua. Improved Benders decomposition method for calculation of 220kV power grid power supply capacity [J]. Chinese Journal of Electrical Engineering. 2017 (17): 4893‐4900" is based on the above literature In the above, the benders decomposition method is improved, and the core accident set screening strategy and the pseudo-serial strategy of "adding one by one, mean feedback" are proposed to improve the calculation efficiency, reduce the calculation time, and optimize the calculation results, but the strategy of "adding one by one" is not practical. In the system calculation, the feedback is easily affected by individual sub-problems, which deviates from the reasonable feedback direction, and the sub-problems that have met the safety check requirements lack an exit mechanism in the feedback scheme, which will weaken the feedback effect

[0004] There are at least the following shortcomings and deficiencies in the prior art: when using the benders decomposition method to calculate the power supply capacity of the power grid, no matter whether it is a parallel method or a pseudo-serial method, it does not take into account the large scale of the actual power system solution, and the slow convergence will increase the calculation time. The problem of premature convergence may fall into a local optimal solution, and the feedback speed is not adjusted according to the gap between the current solution and the optimal solution

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