Fault simulation and pattern recognition in a modular generator under two different power converter configurations

Key focus of this paper is the investigation of condition monitoring and fault-tolerant control in the modular multi-stage air-cored permanent magnet synchronous generator called `C´ core generator under different electrical connections. Condition monitoring and fault-tolerant control have been identified as a means of improving the reliability and availability of offshore or inaccessible renewable energy devices. As a result, two different ways of connecting modular generator stages are presented. Based on the above topologies two wind turbine models are designed in MATLAB^®/Simulink^® and fault-tolerance is investigated by implementing single electrical faults in one of the stages, such as single phase open circuit, diode short circuit, two phase short circuit and diode open circuit. It was found that the first topology offers fault-tolerance against the single phase open circuit fault while the second offers isolation between generator stages in all types of faults. Finally, the signal processing techniques of alpha - beta current locus, Power Spectral Density analysis and Continuous Wavelet Transformation have been implemented in order to extract detectable patterns of the electrical faults.