Small-world Network Characteristic And Failure Analysis Of Power Electronic Converters

Power electronic converters are widely used in industrial, military, aerospace and other important areas. They are indispensable parts in power system and various power and control system. Studing their fault diagnosis technology has an important realistic economic and military significance for improving the reliability of systems and ensuring the availability of equipment.Small-world network theory is a preliminary explore in fault diagnosis analysis. It is also developed in the past decade that can accurately describe the behavior of complex systems and truly reflect the law of the actual network by joining the random network characteristic in former regular network. As the complexity and scale increasing, it plays an important role in energy secondary transformation and utilization. Therefore, it is necessary to use the current theory results research the structure and stability issues from a new perspective. From structural features view of power electronic converters, using the small-world network theory, research and analysis the small-world network characteristic of power electronic converters, structural failures and cascading failures, and obtained some very usefull conclusions.The main fruits are included:(1) Established the small-world network models of power electronic converters, analyzed its small-world network characteristic by calculating the characteristic parameters, obtained some very important conclusions:when the number of nodes reaches a certain size, this kind of power electronic converters network may exist small-world network characteristic; Although the main circuit of switching power supply doesn't have small-world characteristic, when the external control circuits are considered, it will be have.(2) Studied the structural failure feature of power electronic converters. When the converter appears structural failure, put over the small-world network modeling method. Through compared with the normal work situation, analyzed the characteristic parameter characteristic of converters in shut and short faults.(3) Studied the cascading failure characteristics of converters. Analyzed the cascading failure characteristics from random attack model and based on the node degree chain attack model and based on the number of nodes chain attack model.