Online Detecting of Inter-Turn Short-Circuit in Generator Rotor Winding Relying on ν-SVR Machine

To probe an accurate diagnosing approach for synchronous generator (SG) with rotor winding inter-turn short-circuit, a novel online monitoring and detecting method relying on the [Formula: see text]-support vector regression ([Formula: see text]-SVR) machine was proposed, and its effectiveness was further verified by the micro-synchronous generator dynamic simulation. Terminal voltage, active and reactive power of SG were selected as input variables for a novel prediction model based on the [Formula: see text]-SVR, and field current was selected as an output variable of the prediction model. The structures and parameters of the field current prediction model were optimized with the particle swarm optimization (PSO) algorithm and training samples, then the prediction model was established and the field current prediction got under way. By comparing the predicted field current with the corresponding online measured field current, inter-turn short-circuit of rotor winding in SG could be detected sensitively once its absolute value of the prediction relative error exceeded a specific threshold. The micro-synchronous generator dynamic simulation indicated that the proposed online detecting approach based on the [Formula: see text]-SVR machine overcame the shortage of the back-propagation (BP) diagnosis method for misdiagnosis, and its accuracy, sensitivity and threshold setting range of the diagnosis method was the most prominent among these diagnosis methods such as the BP diagnosis method, the Bayesian regularization back-propagation (BRBP) diagnosis method and the [Formula: see text]-support vector regression ([Formula: see text]-SVR) diagnosis method.

The Origin Alignment Method of Box Parts Based on Boring and Milling Machining Center

Based on complex body parts structure, the characteristics of batch processing and high accuracy requirement, in order to improve the efficiency of its alignment, put forward about the case accessories are the method of study the origin. During the study, in order to type boring and milling machining center for processing platform, build online detecting system for the body parts. By mathematical modeling and knowledge of analytic geometry, the rotary table any position of body parts in machining center is to find the origin, and determine the size of the work-piece origin of coordinates and the deflection angle. Checked by practice, this method is suitable for composite boring and milling machining center mass production of body parts in work, improve the efficiency of the box body parts processing precision and alignment.

Online Detection and Control of Strip Steel Mechanical Properties in Skin-Pass Process

Firstly, the online detecting and controlling models of the strip steel mechanical properties in skin-pass process are proposed in this paper. The models are used to overcome the shortage of the conventional monitoring methods, and to reduce the fluctuations of the mechanical properties of the strip. The new online detecting and controlling models can real-time forecast the mechanical properties of the running strip from the online monitoring devices. The bias control between the forecasting and the target values of the mechanical properties can be corrected by adjusting the strip elongation . As a result , the fluctuations of the mechanical properties of the strip are reduced ,and move over,it is helpful to prevent the higher yield strength and lower tensile strength, and to maintain good formability strip.The experiments are done and verify the validity of the approach.

Application of Wavelet Analysis to Eddy Current Testing for the Surface Fatigue Crack of Bolt Holes

Eddy current testing is one of the five major routine nondestructive testing methods and it is convenient, fast and suitable for online detecting of the surface fatigue crack of bolt holes. However, the signals of eddy current testing are so weak that it is difficult to identify the signals. So more effective signal processing method must be adopted to deal with the weak signals. This paper used the wavelet analysis to process signals of the eddy current testing for the surface flaw of bolt holes. It can inhibit the noise and reinforce signal and make qualitative testing possible for quality evaluation of the surface fatigue crack of bolt holes.