Intelligent fault diagnosis and fault tolerant control on nonlinear excitation system

Applied excitation system of medium-small-scale synchronous generator as the object, studied on-line intelligent fault diagnosis and active fault tolerant control of nonlinear system. Presented hierarchical diagnosis method and intelligent diagnosis model based on fusion theory, whose diagnosis strategy fused qualitative reasoning with quantitative reasoning, and fused the local with the whole so as to ensure real-time performance and to improve diagnosis accuracy as well. Modified the structure of excitation system by a novel approach, which strengthened the hardware redundancy and fault diagnosis ability, only an additional sensor was needed in the control system. By fusing analytic redundancy with control reconfiguration, presented soft fault tolerant control strategy to realize hierarchical active fault tolerant control. Based on above-mentioned ideas, the developed excitation control system has been applied to water-turbine generator sets at 5000K-W. Field performances show that the system could realize real-time and accurate fault diagnosis with better reliability and maintainability.