Stator winding fault diagnosis in synchronous generators for wind turbine applications

Wind turbine manufacturers have introduced to the market a variety of innovative concepts and configurations for generators to maximize energy capture, reduce costs and improve reliability of wind energy. For the purpose of improving reliability and availability, a number of diagnostic methods have been developed. Stator current signature analysis (SCSA) is potentially an effective technique to diagnose faults in electrical machines, and could be used to detect and diagnose faults in wind turbines. In this study, an investigation was conducted into the application of SCSA to detect stator inter-turn faults in an excited synchronous generator and a permanent magnet synchronous generator. It was found from simulation results that, owing to disruption of magnetic field symmetry and imbalance between the current flowing in the shorted turn and the corresponding diametrically opposite turn in the winding, certain harmonic components in the stator current clearly increased as the number of shorted turns increased. The findings are helpful to detect faults involving only a few turns without ambiguity, in spite of the difference in the configuration of the generators. As expected, because of the different type, configuration and operational condition of the two generators studied, detecting faults through the generator current signature requires a particular approach for each generator type

Steady-state analysis of a conceptual offshore wind turbine driven electricity and thermocline energy extraction plant

A system for using offshore wind energy to generate electricity and simultaneously extract thermal energy is proposed. This concept is based on an offshore wind turbine driven hydraulic pump supplying deep seawater under high pressure to a land based plant consisting of a hydroelectric power generation unit and heat exchanger. A steady-state system model is developed using empirical formulae. The mathematical model comprises the fundamental system sub-models that are categorised as the rotor, hydraulic pump, pipeline, hydroelectric turbine and heat exchanger. A means for modelling the seawater temperature field across a two-dimensional bathymetry is also discussed. These mathematical models are integrated into a computational tool and a brief parametric static analysis is undertaken. The results illustrate the effect of pipeline diameter, rotational speed of the grid connected hydroelectric turbine, and the turbine distance from shore on the overall performance of the system. Through adequate parameter selection, the total rate of energy output for such a system, consisting of both electricity and thermal energy, is shown to increase by as much as 84%, when compared to a conventional wind turbine having an identical rotor diameter but which supplies only electrical energy.peer-reviewe

Electric-Motor-Driven Gas Compressor Packages: Starting Methods for Large Electrical Motors and Torsional Integrity

Tutoria

Electric-Motor-Driven Gas Compressor Packages: Starting Methods for Large Electrical Motors and Torsional Integrity

Tutoria