Design And Analysis Of Core Fault Diagnose System For Large Electrical Machines

The large generator is the main power production equipment of the powerindustry, whether can be reliable and persistent work, and will directly affect theeconomic development of the whole nation. But as a result of the ElectricalMachines run with full load for long time and other factors, the fault of ElectricalMachines will inevitably occur, which will be reconditioned without delay, andso not only can avoid the irreparable further development and extend the servicelife of the motor. The core fault owns large proportion of all kinds fault of largemotor. If the core faults sustain development, and impacts on the whole motorwill be much higher than that of other motor fault. Therefore, it is particularlyimportant to fast detect the motor iron core fault during the period of motormaintenance.The core cause of fault and its development mechanism are detailedlyanalyzed. A method for analyzing the eddy current fields and resultant losses ispresented in the core fault zone of laminations which occurs the core faults. It isbased on the finite-element method which uses the three-dimensional magneticscalar potential magneto dynamic T, formulation and a newly developedhomogenization method is applied to model the laminations with the core faultseffectively. For ascertaining fields under different frequencies, the effectivedepths of the skin in different directions for the anisotropic core are deduced,which are accompanied with the adaptively generated mesh of finite-elementmodels. As an example of utilizing the means developed above, the eddy-currentand losses in a large asynchronous machine core with core faults are computed inwide range of frequency. The calculations results, based on the homogenizationmodel by introducing anisotropic conductivity and on the direct methodinvolving the actual description of lamination, respectively, were analyticalcomparison. The results of the comparison display the stator faults analyzed by the continuum model with the anisotropic conductivity can satisfy the actualaccuracy requirement at low frequencies. Theoretical guidance for the design ofLarge Electrical Machines core fault detection system is provided, using thefinite element software to quantitative analysis of the impact of core fault.The principle of large Electrical Machines fault detection system is carefullystudied. The large motor iron core fault detection system designed is using theembedded system of ARM and LwIP protocol Ethernet communication and themicroprocessor LM3S8962serves as the main control chip in this paper. Thehardware and software required by the system are designed based on the actualtesting needs. And which are utilized, and large motor core fault detection systemis designed and produced. The core fault detection system does not only have allthe advantages of the initial product, but overwhelming the drawbacks. To actualfault of core, the field experiment can confirm the designed and produced largecore fault detection system is suitable. The system has the advantages includingfast, accurate, convenient, reliable, high sensitivity, etc. The paper representedthe core fault detection method will be the future developed direction of corefault detection, which compared to the other methods.