Study On Several Key Numerical Algorithms For A Novel Transformer Impulse Fault Detecting System

A power transformer is one of the most important units in power networks; thus, the breakdown of a transformer leads to an abrupt halt of an overall process and costly repairs. So, evaluation becomes one of the most important parts of power transformer impulse testing. The traditional methods analyze faults only from time domain or only frequency domain. But all these methods have defects: frequency spectrums can not be shown at time domain, and time consequences can not be shown at frequency domain too. These defects restrict the accuracy of detecting. This paper provides a new method (based on Joint Time-Frequency Analyses theory), which can analyze faults at both time and frequency domains. Besides JTFA, this method also based on Virtual Instrument (VI) technology, and this technology would make the detecting more convenient, more precise, and more directviewing. Besides, this detecting system combines several advanced DSP technologies for the process of transient High-Voltage signal. Test results form a real transformer show that this system is suitable for fault detecting and its accuracy and compatibility is wonderful.