AC-DC hybrid system stability analysis method and system based on mixed potential function

Abstract

The present invention discloses an AC-DC hybrid system stability analysis method and system based on a mixed potential function. The method comprises the following steps of: establishing an equivalentmodel of a mixed potential function theory; constructing a mixed potential function of an AC-DC hybrid system to be researched by employing the equivalent model; and reconstructing the mixed potential function, solving a characteristic root according to the reconstructed mixed potential function, and employing a mixed potential function third stability theory to obtain stability criteria of the AC-DC hybrid system. The method can establish the potential function of the system in terms of energy to avoid complex value integration, facilitate obtaining of dynamic safety criteria in an analysismode and provide basis for formulation of a system safety operation control strategy, and the construction of the potential function of the mixed potential function method aims at a current and a voltage of a special branch of a general non-linear circuit network without relating to the electric quantity of a rotation unit, so that the AC-DC hybrid system stability analysis method and system basedon the mixed potential function are very suitable for construction of the energy function of the AC-DC hybrid system by taking power electronic equipment as a principal thing.

Description

technical field [0001] The invention relates to the technical field of stability analysis of an AC / DC hybrid system of a power electronic transformer, in particular to an AC / DC hybrid system stability analysis method and system based on a mixed potential function. Background technique [0002] In recent years, my country's distributed renewable energy has grown rapidly, and large-scale distributed renewable energy is connected to the grid, which poses new challenges and higher requirements for flexible access and effective control of the system. At present, there are many AC-DC conversion links in the renewable energy access technology, which reduces the efficiency and affects the convenience of access. In addition, the lack of mutual aid and flexible regulation capabilities of the distribution network also limits the full consumption and efficient utilization of distributed renewable energy. Using bidirectional multi-port power electronic transformers to build an AC-DC hyb...

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Problems solved by technology

The classical energy function method commonly used in large power grids mainly analyzes the kinetic energy and potential energy of the rotating unit (the core dynamic element of the system) in the system, while the main dynamic element in the AC / DC hybrid system is the power electronic device rather than the rotating unit. , the classical energy function method is difficult to give its kinetic energy and potential energy, and it is not applicable to the AC / DC hybrid system

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