Transmission network risk assessment method considering substation influence

Abstract

Disclosed is a transmission network risk assessment method considering substation influence. The method includes the steps of first collecting reliability parameter data of a local power grid and eachsubstation internal component as well as basic parameter data of the substation internal relay protection; then establishing a Markov state model of the power grid and the substation internal components and a relay protection implicit failure model, and determining the probability of occurrence of the components and relay protection states; then sampling a system state by using an improved non-sequential Monte Carlo simulation method; and finally, analyzing the load loss risk of the system state by using a load shedding optimization model based on the DC flow, calculating a risk index of thetransmission network and assessing the risk of the transmission network according to the risk index. The method in the invention can reflect the influence of the substation on the risk assessment of the transmission network to the greatest extent, further improves the accuracy and real-time performance of risk assessment under the premise of meeting the calculation precision, and can provide a reliable basis for power grid operators to understand the real-time risk of the power grid.

Description

technical field [0001] The invention relates to a method capable of accurately evaluating the operation risk of a power grid, and belongs to the technical field of power transmission and distribution. Background technique [0002] In the power system, as a key link in the power grid, the substation undertakes the power supply task from the transmission network to the user, and its main wiring directly affects the safety and stability of the power grid and the reliability of power supply. Therefore, it is of great practical significance to study the risk assessment method of transmission network considering the impact of substations. [0003] In the actual power grid, due to the mutual influence between the substation and the grid, the reliability of the substation with the same wiring form may vary with the role and position of the substation in the system. Therefore, the impact of substations on the power grid should be considered when evaluating system risk from the persp...

AI Technical Summary

Problems solved by technology

At present, the transmission network risk assessment methods considering the impact of substations can be divided into two categories. One is to analyze the reliability of the main wiring of the substation first, and then equivalent it to a bus node with a probability of failure, so as to realize the connection between the main wiring of the substation and the transmission network. This method not only improves the evaluation speed of the power grid, but also dilutes the impact of the main wiring of the substation on the power grid; the second is a hybrid method that combines the analytical method and the Monte Carlo simulation analytical method. First, the minimum cut set method is used to obtain the substation On this basis, the state sampling of the equipment in the transmission network is carried out, and the risk index of the entire transmission network is calculated after the simulation of the specified time is completed. This method is difficult to simulate the randomness of the internal component failure of the substation, and in the same The calculation accuracy is more time-consuming

Therefore, the existing transmission network risk assessment methods considering the impact of substations are not ideal in terms of assessment accuracy, and further research is needed

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