Investigation of the influence from micro brush fire in wind generators to avoid minimize the maintenance costs

• Applicant: Professor Dr.-Ing. Wilfried Hofmann
• Subject Area: Electrical Energy Systems, Power Management, Power Electronics, Electrical Machines and Drives
• Term: from 2009 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 110530434

The double fed asynchronous generators is state of the art in wind turbines. Therefore, the slip ring system is used to transfer the rotor currents in the network. Sometimes transmission troubles occur and these can be recognizing in the measurements electrical signals. These Troubles are electrical discharges that are characterized as macro or micro brush fires.In the previous project, through the numerical analysis in Ansys the relationship between the electrical, mechanical thermal und magnetic Parameters our system was investigated. These parameters are playing an important role in the power transmission. The results were compared with the results from the build measurement system. We obtained that the transmission troubles increase with the combination of decreasing of the contact force and of increasing of the circumferential speed. In addition, we realize that the frictional coefficient resides between the region of the mixed friction and the fluid friction. Furthermore, through the diagnostic method the noise signals that represent the electrical discharges will be separated from the measurements signals. These results will give us more information about the beginning of the electrical discharges and the magnitude of the combining parameters. Other goal is to analyze the contribution of the elasto-hydrodynamic force in the frictional coefficient through a numerical analysis.

• DFG Programme: Research Grants