Open-circuit fault diagnosis method of current transformer of permanent-magnet direct-drive type wind power generation system

• Main Authors: LIU JINGJIA, GAO JIAN, HUANG SHOUDAO, HUANG KEYUAN, ZHOU LIZE
• Format: Patent
• Language: Chinese; English
• Published: 09.10.2013
• Subjects: CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTINGELECTRIC POWER; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; GENERATION; MEASURING; MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES; PHYSICS; SYSTEMS FOR STORING ELECTRIC ENERGY; TESTING

Disclosed in the invention is an open-circuit fault diagnosis method of a current transformer of a permanent-magnet direct-drive type wind power generation system. The open-circuit fault diagnosis method is used for detecting an open-circuit fault of a certain IGBT of the current transformer in the direct-drive type wind power system and determining a position which a fault device is located at. The method comprises two parts: fault detection and fault positioning. Specifically, according to a changing characteristic of a current when a fault occurs, a fault occurrence of the current transformer is detected based on current park conversion vector phase changing, thereby effectively avoiding wrong detection caused by the load sudden change; a position of a fault IGBT of a machine-side current transformer is determined by a zone which a three-phase average current park conversion vector phase of the motor is located at; and fault positioning of a grid-side current transformer is determined according to positive