Research On Fault Warning And Diagnosis Of Double-fed Induction Generator

The VSCF wind power technology is developing rapidly since its birth, and quickly become the mainstream in the wind power industry. This new wind power technology solved the biggest problem that plagued the field of wind power, which is how to get a stable power output at variable wind conditions. Doubly-fed induction generator, as the core equipment of the VSCF wind power technology, with its specific electromagnetic structure and the operation strategy, keeps a stable power output to the grid at a variable speed operation condition. Its commercialize promotion not only substantially increased the quality of wind power, but also greatly improved the security of wind turbines and the grid.In the process of localization of wind power technology, the localization of Double-fed asynchronous generator is the most critical step. Compared to the conventional turbo generator in thermal power industry, doubly-fed induction generator is intuitively much smaller in geometry. If we do more in-depth analysis of their mechanical structure, electromagnetic relations and control strategies, we will find not only the in geometry, but also in various aspects, the doubly-fed induction generator has its own characteristics. Through some running record of the wind power plant, we can find some common generator faults, and some unique failures of doubly-fed induction generator. Although the mature technology nowadays of turbo generator condition monitoring and fault diagnosis can offer a reference to doubly-fed induction generator, it is not fully applicable. This paper studied the condition monitoring and fault diagnosis technology that applied to doubly-fed induction generator based on the previous studies of power generator equipment monitoring and fault diagnosis.The main contents of this paper are:(l)Elaborating the working principle and operating characteristics of the VSCF wind power technology, and offering a detailed analysis of the organizational structure and the electromagnetic equivalent circuits of the doubly-fed induction generator. Clarifying the context of the relationship of all doubly-fed induction generator monitoring parameters, laying the theoretical foundation for the multi-information fusion of the parameters.(2)Analyzing The existing classification system for generator failures. with the running history of double-fed induction generator from many wind plants, list the failure of doubly-fed induction generator. For these typical faults, the paper analyzes their reasons, the development, the impact and consequences, and a complete list of the online monitoring parameters are collated.(3)A brief analysis of the applicability of the proportion of sampling techniques for variable operating condition of wind turbines. For the on-line monitoring parameters drawn from the analysis, the paper re-sample the signals conversion if necessary, excluding the impact of variable operating conditions on the signal. After processing for the all signals, integrating the change signs for each parameter of each type of failures, forming a complete on-line monitoring and fault diagnosis system.