Reason analysis method for commutation failure of DC transmission system

Abstract

The invention discloses a reason analysis method for a commutation failure of a DC transmission system. An existing research has the disadvantages as follows: analysis of the reason of the commutationfailure is relatively one-sided, or the factors, such as voltage amplitude drop and phase shift are simply analyzed, or the condition that reason analysis focuses on a simulation research of a control strategy or the interaction between multi-drop transmission systems is directly analyzed. According to the reason analysis method, the defects that existing analysis of the reason of the commutationfailure is incomplete and single-stage analysis is relatively one-sided are overcome, for example, the defects that occurrence of a secondary commutation failure cannot be considered and the influences of a harmonic wave and DC magnetic bias of a converter transformer are neglected are also overcome. According to the reason analysis method, the commutation failure process in an AC / DC hybrid system is divided into two different stages and the main reason of the commutation failure is analyzed at different stages, so that the operation stability of an interconnected AC / DC system is achieved when the interconnected AC / DC system is in a failure.

Description

technical field [0001] The invention belongs to the field of direct current transmission system operation and control, in particular to a method for analyzing the cause of phase commutation failure of the direct current transmission system. Background technique [0002] The successful application of the AC-DC hybrid system can effectively alleviate the unbalanced distribution of energy resources and load centers in my country. At the same time, there is no synchronization problem of the AC system connection, which improves the safety of the power grid operation. However, the DC transmission project also faces Some unavoidable questions. [0003] The commutation failure of the converter is a very common type of fault, which brings unpredictable damage and impact to the DC transmission system and the AC transmission system on both sides. Existing studies are relatively one-sided in the analysis of the causes of commutation failure, or simply analyze factors such as voltage amp...

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Problems solved by technology

[0002] The successful application of the AC-DC hybrid system can effectively alleviate the unbalanced distribution of energy resources and load centers in my country. At the same time, there is no synchronization problem of the AC system connection, which improves the safety of the power grid operation. However, the DC transmission project also faces some unavoidable questions

[0003] The commutation failure of the converter is a very common type of fault, which brings unpredictable damage and impact to the DC transmission system and the AC transmission system on both sides

Existing studies are relatively one-sided in the analysis of the causes of commutation failure, or simply analyze factors such as voltage amplitude drop and phase shift, or ignore the cause analysis and focus on the simulation research of control strategies, or directly analyze the multi-drop transmission system. mutual influence

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