Analysis About Electromagnetic Interference Of Lighting On D-PMSG

With the constant improvement of the awareness of clean energy, thedevelopment and utilization of renewable energy–wind power has been developingvery rapidly. Recently, the installed capacity of wind turbines has increased year byyear, the proportion in the whole power grid is also gradually increase. Therefore, thesafe operation of the wind turbine is paid close attention.The installation geographical conditions and building structure of unit increasesthe probability of being struck by lightning, which makes the lightning has becomeone of the most important factors affecting the safe operation of the unit. When thelightning current injects the unit, it flows through the spindle and the cabin along thedown lead to the tower top, and finally leads to the earth by the tower. In the transientprocess, due to lightning has very high wave steepness, it will produce very powerfulmutational electromagnetic field in the path around the flows and interference andinduced voltage of generator field, signal lines, power lines or inner control system,which cause damage to electrical equipment, seriously affect the safe operation of thewind turbine. So, when the wind turbine on lightning conditions, simulation analysisabout interference caused to the generator field and spatial electrical circuit, providesthe theory support for the measures of lightning protection unit, thus effectivelyprotects the safe operation of wind power equipment.This paper is based on the1.2MW permanent magnet direct-drive wind powergeneration unit as the research object. First of all, according to the basic theory ofpermanent magnet synchronous generator and the lightning current, the mathematicalmodel suitable to the analysis in this paper is proposed. Secondly, using ANSYSsoftware models permanent magnet wind turbine generator, and adoptingtwo-dimensional unit vector method and the Maxwell equations calculate the windgenerator internal electromagnetic field under different lightning stroke. Through the analysis of air gap magnetic flux density and magnetic cloud find lightning effects ongenerator internal magnetic field distribution, and analyses the impact to generatoroutput voltage caused by electromagnetic interference. It also analyses theelectromagnetic interference of down lead periphery electric circuit on carryinglightning current, and finds out some factors which determine the interference andputs forward some corresponding protective measures. Finally, by using ANSYSsoftware models and calculates the situation of tower on lightning, analyses thedistribution of magnetic field in the tower and induction voltage in space electroniccircuit, and finds out the decisive factors of induction overvoltage.This paper uses the ANSYS finite element software to simulate wind generatorunder lightning. The results of the study are not only accurate and intuitive, but alsocan provide the theoretical basis for the wind turbine in the installation of electricalequipment and lightning protection, reduce the damage of the safe operation of theunit caused by Lightning electromagnetic interference to the maximum extent.