This paper presents the optimize fault search strategy integrated the factor of fault character information,search cost,fault probability and so on.

Extraction of the Fault Features of Ball Bearings Based on Bispectrum Analysis;

Method of fault feature extraction for analog circuits based on EMD

In order to get a characterized wavelet with expected properties of fault features extraction,by using the lifting scheme(LS),a new wavelet is constructed.

Analysis of the fault characteristics of a rotor with a transverse crack;

The fault will result in fault characteristic component in stator current.

The fault characteristics of transient travelling waves are described using the dyadic discrets wavelet transform (DDWT) to present the travelling waves.

With FEM used to simulate the rotor system on which the looseness fault is occurring,the fault characteristics are obtained as follows.

The extracted approach of fault characters based on high order spectrum for the gas valves of piston compressors is investigated.

Finally,the bicepstrum technique is adopted to extract the fault characters of the vibration signal for roller bearing.

The wavelet transform modulus maximum of transient signal indicates the important fault character and provides means for relay protection and fault location in power system.

Aming at the difficult problem todistilling the tractive fault character of convertor,genetic programming method is adopted to distill the best fault character inthis paper and answers achieved by this method can effectively solve the problem.