Stability Analysis Method and System for AC-DC Hybrid System Based on Mixed Potential Function

Abstract

The invention discloses a method and system for analyzing the stability of an AC / DC hybrid system based on a mixed potential function, wherein the method includes the following steps: building an equivalent model of the mixed potential function theory; constructing an AC / DC system to be studied through the equivalent model The mixed potential function of the hybrid system; the mixed potential function is reconstructed, and the characteristic root is solved according to the reconstructed mixed potential function, and the stability criterion of the AC-DC hybrid system is obtained by using the third stability theory of the mixed potential function. This method can establish the potential function of the system from the perspective of energy, avoids complex numerical integration, and is conducive to obtaining the dynamic safety criterion in the form of analysis, which provides a basis for the formulation of the system's safe operation control strategy, and the potential function of the mixed potential function method The structure is aimed at the current and voltage of the specific branch of the general nonlinear circuit network, and does not involve the power of the rotating unit, so it is very suitable for the construction of the energy function of the AC-DC hybrid system mainly based on power electronic equipment.

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...

AI Technical Summary

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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