Fuzzy recognition processing of complex fault signals from the rotating electric circuit in synchronous generators

The brushless excitation system is widely used in synchronous generators in modern atomic power plants, although the excitation system is a very complicated rotating electric circuit, but because it has some outstanding advantages with being spark-free, higher reliability and little maintenance. When the rotating electric circuit of the brushless excitation system is out of work, in which some of the diodes have some fault conditions, some complex electrical signals will occur in the rotating electric circuit and the signal waveform is very complicated. This paper presents a fuzzy recognition method for the complex signals from the rotating electric circuit and builds the fuzzy diagnosis model. With the help of the method, the faults of the rotating electric circuit can be recognized.

► A kind of coil probe is firstly designed to be placed between the magnetic poles of the AC exciter for the complex signal.
► Using the time–frequency method, we can extract very fast the fault characteristic quantities from the complex signal.
► The fuzzy identification method is firstly used to recognize the rectifier circuit fault inside synchronous generators.