Method and system of reducing hierarchical access direct current commutation failure risk

Abstract

The invention relates to a method and system of reducing a hierarchical access direct current commutation failure risk. The method of reducing a hierarchical access direct current commutation failure risk includes the steps: determining a key fault set influencing a hierarchical access direct current inversion side converter station; adjusting reactive power output of dynamic reactive compensation equipment, performing time domain simulation on the key fault set, and calculating the reactive voltage control sensitivity of a dynamic reactive source; sorting m reactive voltage control flexibilities, and calculating the weight coefficient of the dynamic reactive source; and after calculating the reactive standby capacity of the dynamic reactive source based on the weight coefficient, establishing a dynamic reactive standby optimization model, and utilizing an inner point method to solve the dynamic reactive standby optimization model to obtain the optimized reactive standby capacity. The method and system of reducing a hierarchical access direct current commutation failure risk can provide an optimization model for reducing the hierarchical access direct current commutation failure risk, can improve the transmission capability of the alternating and direct current power transmission channel, and has significant meaning for improving operation stability of power grid.

Description

technical field [0001] The invention relates to the technical field of electric power systems, in particular to a method and system for reducing the risk of layered access DC commutation failure. Background technique [0002] For a long time, there has been serious spatial heterogeneity between my country's energy consumption and resource endowment. Large-scale and long-distance power transmission requirements have promoted the continuous construction and development of EHV DC projects. At present, East China and South China have formed multi-feed into the DC system. With the increasing power of UHV DC transmission, the existing single-layer access method may cause a series of problems in terms of power flow evacuation and voltage stability, and the planned UHV DC transmission projects of 10 million kilowatts and above will be widely used Hierarchical access technology, that is, the high-end converter and low-end converter of the DC system inverter station are connected to t...

AI Technical Summary

Problems solved by technology

The switching speed of the fixed capacitor bank is slow, and the converter station is prone to excess reactive power when the load is lost, resulting in overvoltage of the converter bus;

[0005] (2) The power grid at the receiving end is weak

The operating power grid in East China is very complicated. The electrical distance of the AC system near some DC landing points is relatively long, and the receiving-end system is very weak, and the weak receiving-end system is prone to commutation failure, which will have an impact on the AC system and cause system oscillation. In severe cases, even cause the system to unload

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