A method for emergency switching of capacitors in the vicinity of converter stations to suppress DC commutation failure

Abstract

The invention discloses a method for emergency switching of capacitors in the vicinity of a converter station for suppressing DC commutation failure, determining the nodes involved in emergency control in the DC inverter side converter station station and in the vicinity, as well as the spare capacity and capacity of the capacitors in each node. Number of groups; calculate the sensitivity of switching capacitors at each node to other control nodes and the bus voltage of this node; calculate the number of capacitor groups that need to be put in according to the sensitivity index and the degree of transient voltage drop; calculate according to the sensitivity index and the degree of transient voltage rise Determine the number of capacitor banks to be removed by comparing it with the number of capacitor banks to be put into emergency. The invention can effectively reduce the risk of DC commutation failure caused by the AC fault, and speed up the recovery of the DC commutation failure, thereby reducing the power of the AC system caused by the DC commutation failure. impact, and improve the safe and stable operation level of UHV AC and DC power grids.

Description

technical field [0001] The invention relates to a method for emergency switching of capacitors in the vicinity of a converter station for suppressing DC commutation failure, and belongs to the technical field of electric power systems and automation thereof. Background technique [0002] At present, the unbalanced distribution of energy bases and load centers in my country has objectively promoted the development of UHVDC transmission technology. While HVDC has many advantages, it will inevitably bring many challenges to grid operation control. With the gradual commissioning of large-capacity UHV DC, the characteristics of "strong DC and weak AC" in the early stage of UHV power grid construction have become increasingly prominent, and the AC-DC coupling effect has become increasingly tight. Phase failure or DC continuous commutation failure. The sudden power drop caused by the failure of DC commutation may cause the risk of frequency and voltage instability of the receivin...

AI Technical Summary

Problems solved by technology

The sudden power drop caused by the failure of DC commutation may cause the risk of frequency and voltage instability of the receiving end grid, especially the DC active blocking control triggered by the failure of DC continuous commutation may cause a large load loss of the receiving end grid, threatening the UHV AC power grid. Safe and Stable Operation of DC Hybrid Power Grid

[0003] According to UHV DC design requirements, under normal circumstances, the reactive power interaction between the DC system and the AC system is zero, and a large amount of reactive power needs to be absorbed from the AC system during the DC commutation failure recovery stage, which may cause other DC commutation failures or continuous commutation fail

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