Subsequent commutation failure risk assessment and suppression method for high-voltage direct-current power transmission system

Abstract

The invention discloses a subsequent commutation failure risk assessment and suppression method for a high-voltage direct-current power transmission system. The method comprises the steps of: obtaining a subsequent commutation failure risk assessment index SCFRI based on a commutation voltage time area analysis method; obtaining a commutation voltage effective value, direct-current current and inverter trigger angle instruction value of the high-voltage direct-current power transmission system in real time, calculating an SCFRI, and judging a subsequent commutation failure risk degree; and starting a subsequent commutation failure suppression strategy after the first commutation failure occurs, maintaining the SCFRI index of the system at the control target SCFRI0, and effectively controlling the subsequent commutation failure risk of the system, thereby suppressing the occurrence of subsequent commutation failure to the greatest extent. According to the method provided by the invention, the influence of factors such as direct current, alternating voltage and a trigger angle during a fault transient period is considered, the subsequent commutation failure risk assessment index of the system is established, and the discrimination and quantitative risk assessment of the subsequent commutation failure of the system are realized.

Description

technical field [0001] The invention relates to the technical field of operation analysis and control of a high-voltage direct current transmission system, in particular to a risk assessment and suppression method for subsequent commutation failures of a high-voltage direct current transmission system. Background technique [0002] With the continuous development of my country's economy and society, the role of the power system in the national economy is becoming more and more significant, and the supply capacity and level of the power grid are constantly improving, requiring the power grid to have higher security and reliability. Commutation failure is one of the most common fault types in HVDC technology that relies on grid voltage commutation. If the AC system fault that caused the first commutation failure is not cleared in time or improperly controlled, subsequent commutation failures may occur in the DC system during the recovery stage, which will easily cause local fa...

AI Technical Summary

Problems solved by technology

In addition, as the installed capacity of new energy continues to increase, the anti-interference ability and adjustment ability of the AC system continue to decline. As a hybrid system, the "offensive" and "defensive" sides of the security and stability are in balance, which will cause subsequent commutation failures. increasingly severe impact

For the subsequent commutation failure of HVDC transmission system, domestic and foreign research mainly focuses on the analysis of influencing factors and research on suppression strategies. At present, there is a lack of indicators and suppression strategies that can quantify, real-time, and effectively evaluate the subsequent commutation failure risk in the process of system recovery.

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