Urban transmission grid safety probability assessment method considering elasticity margin

Abstract

The invention relates to an urban transmission grid safety probability assessment method considering an elasticity margin. In the present invention, a wind power plant output probability model and a comprehensive load power demand probability model are used to describe the change of the injection power of a transmission network node; a three-point estimation method is used to select evaluation samples to form a sample evaluation matrix, which reduces the evaluation calculation amount; the change of the injection power of the node causes the power flow of each branch to shift to different degrees, the branch that is sensitive to the power fluctuation of some nodes has a large power flow offset, the RSSD can reflect the sensitivity of the transmission grid safety to the power change of the node; and each sample in the sample evaluation matrix corresponds to the determined node injection power. The high-voltage distribution network reconfiguration performs the load transfer to change theoperation mode to make the transmission grid generate elastic margin. A feasible topological state of the high-voltage distribution network is selected as the operation mode to enable each evaluationsample to have the greatest safety margin.

Description

technical field [0001] The invention relates to the field of safety evaluation of urban power grids, in particular to a safety probability evaluation method for urban power transmission networks considering elastic margin. Background technique [0002] The gradual increase in the penetration rate of distributed power and electric vehicles in the power grid makes the uneven distribution of load in time and space more severe. The high-voltage distribution network (110kV), as the transitional network between the urban transmission network (220kV) and the medium-voltage distribution network (10kV and below), is the key link to ensure the quality and safety of urban power supply. Its topology is flexible and there are a large number of backup lines , by switching the switch state of the main and backup supply paths, the operation mode can be greatly changed, and the power flow distribution of the transmission network can be dredged. As an important carrier of electric energy, th...

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Problems solved by technology

[0003] The technical problem to be solved by the present invention is to provide a method for evaluating the safety probability of the urban transmission network considering the elastic margin, and to solve the problem of inaccurate calculation of the safety margin of the transmission network

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